下载券

合集下载

Collocations

15.COLLOCATIONSKathleen R.McKeown and Dragomir R.RadevDepartment of Computer ScienceColumbia University,New York{kathy,radev}@ This chapter describes a class of word groups that lies between idioms and free word combinations.Idiomatic expressions are those in which the semantics of the whole cannot be deduced from the meanings of the individual constituents. Free word combinations have the properties that each of the words can be re-placed by another without seriously modifying the overall meaning of the com-posite unit and if one of the words is omitted,a reader cannot easily infer it from the remaining ones.Unlike free word combinations,a collocation is a group of words that occur together more often than by chance.On the other hand,unlike idioms,individual words in a collocation can contribute to the overall semantics of the compound.We present some deﬁnitions and examples of collocations,as well as methods for their extraction and classiﬁcation.The use of collocations for word sense disambiguation,text generation,and machine translation is also part of this chapter.15.1IntroductionWhile most computational lexicons represent properties of individual words,in general most people would agree that one knows a word from the“company that it keeps”[18].Collocations are a lexical phenomenon that has linguistic and lexicographic status as well as utility for statistical natural language paradigms. Brieﬂy put,they cover word pairs and phrases that are commonly used in lan-guage,but for which no general syntactic or semantic rules apply.Because of their widespread use,a speaker of the language cannot achieveﬂuency without incorporating them in speech.On the other hand,because they escape charac-terization,they have long been the object of linguistic and lexicographic study in an eﬀort to both deﬁne them and include them in dictionaries of the language.It is precisely because of the fact that they are observable in language that they have been featured in many statistical approaches to natural language processing.Since they occur repeatedly in language,speciﬁc collocations can be acquired by identifying words that frequently occur together in a relatively large sample of language;thus,collocation acquisition falls within the general class of corpus-based approaches to language.By applying the same algorithm to diﬀerent domain-speciﬁc corpora,collocations speciﬁc to a particular sub-language can be identiﬁed and represented.1Once acquired,collocations are useful in a variety of diﬀerent applications. They can be used for disambiguation,including both word-sense and struc-tural disambiguation.This task is based on the principle that a word in a particular sense tends to co-occur with a diﬀerent set of words than when it is used in another sense.Thus bank might co-occur with river in one sense and savings and loan when used in itsﬁnancial sense.A second important applica-tion is translation:because collocations cannot be characterized on the basis of syntactic and semantic regularities,they cannot be translated on a word-by-word basis.Instead,computational linguists use statistical techniques applied to aligned,parallel,bilingual corpora to identify collocation translations and semi-automatically construct a bilingual collocation lexicon.Such a lexicon can then be used as part of a machine translation program.Finally,collocations have been extensively used as part of language generation systems.Generation systems are able to achieve a level ofﬂuency otherwise not possible,by using a lexicon of collocations and word phrases during the process of word selection.In this chapter,weﬁrst overview the linguistic and lexicographic literature on collocations,providing a partial answer to the question“What is a collo-cation?”.We then turn to algorithms that have been used for acquiring col-locations,including word pairs that co-occur inﬂexible variations,compounds that may consist of two or more words that are more rigidly used in sequence, and multi-word phrases.After discussing both acquisition and representation of collocations,we discuss their use in the tasks of disambiguation,translation and language generation.We will limit our discussion to these topics,however we would like to mention that some work has been done recently[3]in using collocational phrases in cross-lingual information retrieval.15.2Linguistic and lexicographic views of collo-cationsCollocations are not easily deﬁned.In the linguistic and lexicographic literature, they are often discussed in contrast with free word combinations at one extreme and idiomatic expressions at the other,collocations occurring somewhere in the middle of this spectrum.A free word combination can be described using general rules;that is,in terms of semantic constraints on the words which appear in a certain syntactic relation with a given headword[12].An idiom, on the other hand,is a rigid word combination to which no generalities apply; neither can its meaning be determined from the meaning of its parts nor can it participate in the usual word-order variations.Collocations fall between these extremes and it can be diﬃcult to draw the line between categories.A word combination fails to be classiﬁed as free and is termed a collocation when the number of words which can occur in a syntactic relation with a given headword decreases to the point where it is not possible to describe the set using semantic regularities.Thus,examples of free word combinations include put+[object]or run+[object]2(i.e.‘manage’)where the words that can occur as object are virtually open-ended.In the case of put,the semantic constraint on the object is relatively open-ended(any physical object can be mentioned)and thus the range of words that can occur is relatively unrestricted.In the case of run(in the sense of‘man-age’or‘direct’)the semantic restrictions on the object are tighter but still fol-low a semantic generality:any institution or organization can be managed(e.g. business,ice cream parlor,etc.).In contrast to these free word combinations,a phrase such as explode a myth is a collocation.In itsﬁgurative sense,explode il-lustrates a much more restricted collocational range.Possible objects are limited to words such as belief,idea,theory.At the other extreme,phrases such as foot the bill orﬁll the bill function as composites,where no words can be interchanged and variation in usage is not generally allowed.This distinction between free word combinations and collocations can be found with almost any pair of syn-tactic categories.Thus,excellent/good/useful/useless dictionary are examples of free word adjective+noun combinations,while abridged/bilingual/combinatorial dictionary are all collocations.More examples of the distinction between free word combinations and collocations are shown in Table1.Idioms Collocations Free word combinationsto kick the bucket to trade actively to take the busdead end table of contents the end of the roadto catch up orthogonal projection to buy a houseTable1:Collocations vs.idioms and free word combinations.Because collocations fall somewhere along a continuum between free-word combinations and idioms,lexicographers have faced a problem in deciding when and how to illustrate collocations as part of a dictionary.Thus,major themes in lexicographic papers address the identiﬁcation of criteria that can be used to determine when a phrase is a collocation,characteristics of collocations,and representation of collocations in dictionaries.Given the fact that collocations are lexical in nature,they have been studied primarily by lexicographers and by relatively fewer linguists,although early linguistic paradigms which place emphasis on the lexicon are exceptions(e.g.[22,30]).In this section,weﬁrst describe properties of collocations that surface repeatedly across the literature. Next we present linguistic paradigms which cover collocations.We close the sec-tion with a presentation of the types of characteristics studied by lexicographers and proposals for how to represent collocations in diﬀerent kinds of dictionaries.15.2.1Properties of collocationsCollocations are typically characterized as arbitrary,language-(and dialect-) speciﬁc,recurrent in context,and common in technical language(see overview by[37]).The notion of arbitrariness captures the fact that substituting a synonym for one of the words in a collocational word pair may result in an3infelicitous lexical combination.Thus,for example,a phrase such as make an eﬀort is acceptable,but make an exertion is not;similarly,a running commen-tary,commit treason,warm greetings are all true collocations,but a running discussion,commit treachery,and hot greetings are not acceptable lexical com-binations[5].This arbitrary nature of collocations persists across languages and dialects. Thus,in French,the phrase r´e gler la circulation is used to refer to a policeman who directs traﬃc,the English collocation.In Russian,German,and Serbo-Croatian,the direct translation of regulate is used;only in English is direct used in place of regulate.Similarly,American and British English exhibit arbitrary diﬀerences in similar phrases.Thus,in American English one says set the table and make a decision,while in British English,the corresponding phrases are lay the table and take a decision.In fact,in a series of experiments,Benson [5]presented non-native English speakers and later,a mix of American English and British English speakers,with a set of25sentences containing a variety of American and British collocations.He asked them to mark them as either American English,British English,World English,or unacceptable.The non-native speakers got only22%of them correct,while the American and British speakers got only24%correct.While these properties indicate the diﬃculties in determining what is an acceptable collocation,on the positive side it is clear that collocations occur frequently in similar contexts[5,12,22].Thus,while it may be diﬃcult to deﬁne collocations,it is possible to observe collocations in samples of the language. Generally,collocations are those word pairs which occur frequently together in the same environment,but do not include lexical items which have a high overall frequency in language[22].The latter include words such as go,know, etc.,which can combine with just about any other word(i.e.are free word combinations)and thus,are used more frequently than other words.This property,as we shall see,has been exploited by researchers in natural language processing to identify collocations automatically.In addition,researchers take advantage of the fact that collocations are often domain speciﬁc;words which do not participate in a collocation in everyday language often do form part of a collocation in technical language.Thus,ﬁle collocates with verbs such as create, delete,save when discussing computers,but not in other sublanguages.Stubbs[42]points out some other interesting properties of collocations.For example,he indicates that the word cause typically collocates with words ex-pressing negative concepts,such as accident,damage,death,or concern.Con-versely,provide occurs more often with positive words such as care,shelter,and food.15.2.2Halliday and Mel’ˇc ukMany lexicographers point back to early linguistic paradigms which,as part of their focus on the lexicon,do address the role of collocations in language[30,22]. Collocations are discussed as one ofﬁve means for achieving lexical cohesion in Halliday and Hasan’s work.Repeated use of collocations,among other devices4such as repetition and reference,is one way to produce a more cohesive text. Perhaps because they are among the earliest to discuss collocations,Halliday and Hasan present a more inclusive view of collocations and are less precise in their deﬁnition of collocations than others.For them,collocations include any set of words whose members participate in a semantic relation.Their point is that a marked cohesive eﬀect in text occurs when two semantically related words occur in close proximity in a text,even though it may be diﬃcult to systematically classify the semantic relations that can occur.They suggest ex-amples of possible relations,such as complementarity(e.g.,boy,girl),synonyms and near-synonyms,members of ordered sets(e.g.,Monday,Tuesday;dollars, cents),part-whole(e..g,car,brake),as well as relations between words of diﬀer-ent parts of speech(e.g.,laugh,joke:blade,sharp;garden,dig).They point to the need for further analysis and interpretation of collocations in future work; for their purpose,they simply lump together as collocations all lexical relations that cannot be called referential identity or repetition.In later years,Mel’ˇc uk provided a more restricted view of collocations.In the meaning–text model,collocations are positioned within the framework of lexical functions(LFs).An LF is a semantico-syntactic relation which connects a word or phrase with a set of words or phrases.LFs formalize the fact that in language there are words,or phrases,whose usage is bound by another word in the language.There are roughly50diﬀerent simple LFs in the meaning–text model,some of which capture semantic relations(e.g.the LF anti posits a relation between antonyms),some of which capture syntactic relations(e.g.A0 represents nouns and derived adjectivals such as sun–solar),while others capture the notion of restricted lexical co-occurrence.The LF magn is one example of this,representing the words which can be used to magnify the intensity of a given word.Thus,magn(need)has as its value the set of words{great,urgent, bad},while magn(settled)has the value{thickly},and magn(belief)the value {staunch}.O per1is another LF which represents the semantically empty verb which collocates with a given object.Thus,the O per1of analysis is{perform}.15.2.3Types of collocationsIn an eﬀort to characterize collocations,lexicographers and linguists present a wide variety of individual collocations,attempting to categorize them as part of a general scheme[2,5,12].By examining a wide variety of collocates of the same syntactic category,researchers identify similarities and diﬀerences in their behavior,in the process coming a step closer to providing a deﬁnition. Distinctions are made between grammatical collocations and semantic colloca-tions.Grammatical collocations often contain prepositions,including paired syntactic categories such as verb+preposition(e to,put on),adjec-tive+preposition(e.g.afraid that,fond of),and noun+preposition(e.g.by accident,witness to).In these cases,the open-class word is called the base and determines the words it can collocate with,the collocators2.Often,com-putational linguists restrict the type of collocations they acquire or use to a subset of these diﬀerent types(e.g.[11]).Semantic collocations are lexically5restricted word pairs,where only a subset of the synonyms of the collocator can be used in the same lexical context.Examples in this category have already been presented.Another distinction is made between compounds andﬂexible word pairs. Compounds include word pairs that occur consecutively in language and typi-cally are immutable in function.Noun+noun pairs are one such example,which not only occur consecutively but also function as a constituent.Cowie[12]notes that compounds form a bridge between collocations and idioms,since,like col-locations,they are quite invariable,but they are not necessarily semantically opaque.Since collocations are recursive(ibid.),collocational phrases,includ-ing more than just two words,can occur.For example,a collocation such as by chance in turn collocates with verbs such asﬁnd,discover,notice.Flexible word pairs include collocations between subject and verb,or verb and object; any number of intervening words may occur between the words of the colloca-tion.15.2.4Collocations and dictionariesAﬁnal,major recurring theme of lexicographers is where to place collocations in dictionaries.Placement of collocations is determined by which word functions as the base and which functions as the collocator.The base bears most of the meaning of the collocation and triggers the use of the collocator.This distinction is best illustrated by collocations which include“support”verbs: in the collocation take a bath,bath is the base and the support verb take,a semantically empty word in this context,the collocator.In dictionaries designed to help users encode language(e.g.generate text),lexicographers argue that the collocation should be located at the base[23].Given that the base bears most of the meaning,it is generally easier for a writer to think of the baseﬁrst. This is especially the case for learners of a language.When dictionaries are intended to help users decode language,then it is more appropriate to place the collocation at the entry for the collocator.The base–collocator pairs listed in Table2illustrate why this is the case.Base Collocator Examplenoun verb set the tablenoun adjective warm greetingsverb adverb struggle desperatelyadjective adverb sound asleepverb preposition put onTable2:Base–collocator pairs615.3Extracting collocations from text corpora Early work on collocation acquisition was carried out by Choueka et al.[8]. They used frequency as a measure to identify a particular type of collocation, a sequence of adjacent words.In their approach,they retrieved a sequence of words that occurs more frequently than a given threshold.While they were theoretically interested in sequences of any length,their implementation is re-stricted to sequences of two to six words.They tested their approach on an 11million word corpus from the New York Times archives,yielding several thousand collocations.Some examples of retrieved collocations include home run,fried chicken,and Magic Johnson.This work was notably one of theﬁrst to use large corpora and predates many of the more mainstream corpus based approaches in computational linguistics.Their metric,however,was less so-phisticated than later approaches;because it was based on frequency alone,it is sensitive to corpus size.Church,Hanks,and colleagues[11,10]used a correlation-based metric to retrieve collocations;in their work,a collocation was deﬁned as a pair of words that appear together more than would be expected by chance.To estimate correlation between word pairs,they used mutual information as deﬁned in Information Theory[34,17].If two points(words)x and y have probabilities P(x)and P(y),then their mutual information I(x,y)is deﬁned to be[9]:I(x,y)=log2P(x,y) P(x)·P(y)In the formula,P(x,y)is the probability of seeing the two words x and y within a certain window.Whenever P(x,y)=P(x)·P(y),the value of I(x,y)becomes0which is an indication that the two words x and y are not members of a collocation pair.If I(x,y)<0,then the two words are in complementary distribution[9].Other metrics for computing strength of collocations are discussed in[32].Church et al.’s approach was an improvement over that of Choueka et al.in that they were able to retrieve interrupted word pairs,such as subject+verb or verb+object collocations.However,unlike Choueka et al.,they were restricted to retrieving collocations containing only two words.In addition,the retrieved collocations included words that are semantically related(e.g.doctor–nurse, doctor–dentist in addition to true lexical collocations.Smadja and his colleagues[36,37,38]addressed acquisition of a wider variety of collocations than either of the two other approaches.This work featured the use of a severalﬁlters based on linguistic properties,the use of several stages to retrieve word pairs along with compounds and phrases,and an evaluation of retrieved collocations by a lexicographer to estimate the number of true lexical collocations retrieved.Their system Xtract began by retrieving word pairs using a frequency-based metric.The metric computed the z-score of a pair,byﬁrst computing the average frequency of the words occurring within a ten-word radius of a7given word and then determining the number of standard deviations above the average frequency for each word pair.Only word pairs with a z-score above a certain threshold were retained.In contrast to Choueka et al.’s metric,this metric ensured that the pairs retrieved were not sensitive to corpus size.This step is analogous to the method used by both Choueka et al.and Church et al., but it diﬀers in the details of the metric.In addition to the metric,however,Xtract used three additionalﬁlters based on linguistic properties.Theseﬁlters were used to ensure an increase in the accuracy of the retrieved collocations by removing any which were not true lexical collocates.First,Xtract removed any collocations of a given word where the collocate can occur equally well in any of the ten positions around the given word.Thisﬁlter removed semantically related pairs such as doctor–nurse,where one word can simply occur anywhere in the context of the other;in contrast, lexically constrained collocations will tend to be used more often in similar positions(e.g.an adjective+noun collocation would more often occur with the adjective several words before the noun).A secondﬁlter noted patterns of interest,identifying whether a word pair was always used rigidly with the same distance between words or whether there is more than one position.Finally, Xtract used syntax to remove collocations where a given word did not occur signiﬁcantly often with words of the same syntactic function.Thus,verb+noun pairs wereﬁltered to remove those that did not consistently present the same syntactic relation.For example,a verb+noun pair that occurred equally often in subject+verb and verb+object relations would beﬁltered out.After retrieving word pairs,Xtract used a second stage to identify words which co-occurred signiﬁcantly often with identiﬁed collocations.This way,the recursive property of collocations noted by[12]was accounted for.In this stage, Xtract produced all instances of appearance of the two words(i.e.concordances) and analyzed the distributions of words and parts of speech in the surround-ing positions,retaining only those words around the collocation that occurred with probability greater than a given threshold.This stage produced rigid compounds(i.e.adjacent sequences of words that typically occurred as a con-stituent such as noun compounds)as well as phrasal templates(i.e.idiomatic strings of words possibly including slots that may be replaced by other words). An example of a compound is(1),while an example of a phrasal template is (2).(1)the Dow Jones industrial average(2)The NYSE’s composite index of all its listed common stocks fell*NUMBER*to*NUMBER*.Xtract’s output was evaluated by a lexicographer in order to identify preci-sion and recall.4,000collocations produced by theﬁrst two stages of Xtract, excluding the syntacticﬁlter,were evaluated in this manner.Of these,40%were identiﬁed as good collocations.After further passing these through the syntactic ﬁlter,80%were identiﬁed as good.This evaluation dramatically illustrated the importance of combining linguistic information with syntactic analysis.Recall8was only measured for the syntacticﬁlter.It was noted that of the good collo-cations identiﬁed by the lexicographer in theﬁrst step of output,the syntactic ﬁlter retained94%of those collocations.15.4Using collocations for disambiguationOne of the more common approaches to word-sense disambiguation involves the application of additional constraints to the words whose sense is to be deter-mined.Collocations can be used to specify such constraints.Two major types of constraints have been investigated.Theﬁrst uses the general idea that the presence of certain words near the ambiguous one will be a good indicator of its most likely sense.The second type of constraint can be obtained when pairs of translations of the word in an aligned bilingual corpus are considered.Research performed at IBM in the early1990s[7]applied a statistical method using as parameters the context in which the ambiguous word appeared.Seven factors were considered:the words immediately to the left or to the right to the ambiguous word,theﬁrst noun and theﬁrst verb both to the left and to the right,as well as the tense of the word in case it was a verb or theﬁrst verb to the left of the word otherwise.The system developed indicated that the use of collocational information results in a13%increase in performance over the conventional trigram model in which sequences of three words are considered.Work by Dagan and Itai[14]took the ideas set forth in Brown et al.’s work further.They augmented the use of statistical translation techniques with lin-guistic information such as syntactic relations between words.By using a bilin-gual lexicon and a monolingual corpus of one language,they were able to avoid the manual tagging of text and the use of aligned corpora.Other statistical methods for word sense disambiguation are discussed in Chapter YZX.Church et al.[9]have suggested a method for word disambiguation in the con-text of Optical Character Recognition(OCR).They suggest that collocational knowledge helps choose between two words in a given context.For example,the system may have to chooose between farm and form when the context is either:(3)federal...creditor(4)some...ofIn theﬁrst case,the frequency of federal followed by farm is0.50,while the frequency of federal followed by form is0.039.Similarly,the frequencies of credit following either farm or form are0.13and0.026,respectively.One can therefore approximate the probabilities for the trigram federal farm credit, which is(0.5×10−6)×(0.13×10−6)=0.065×10−12and for federal form credit, which is(0.039×10−6)×(0.026×10−6)=0.0010×10−12.Since theﬁrst of these probabilities is65times as large as the second one,the OCR system can safely pick farm over form in(3).Similarly,form is273times more likely than9farm in(4).Church et al.also note that syntactic knowledge alone would not help in such cases,as both farm and form are often used as nouns.15.5Using collocations for generationOne of the most straightforward applications of collocational knowledge is in natural language generation.There are two typical approaches applied in such systems:the use of phrasal templates in the form of canned phrases and the use of automatically extracted collocations for uniﬁcation-based generation.We will describe some of the existing projects using both of these approaches.At the end of this section we will also mention some other uses of collocations in generation.15.5.1Text generation using phrasal templatesSeveral early text-generation systems used canned phrases as sources of col-locational information to generate phrases.One of them was UC(Unix con-sultant),developed at Berkeley by Jacobs[25].The system responded to user questions related to the Unix operating system and used text generation to con-vey the answers.Another such system was Ana,developed by Kukich[27]at the University of Pittsburgh,which generated reports of activity on the stock market.The underlying paradigm behind generation of collocations in these two systems was related to the reuse of canned phrases,such as the following from[27]:opened strongly,picked up momentum early in trading,got oﬀto a strong start.On the one hand,Kukich’s approach was computationally tractable,as there was no processing involved in the generation of the phrases,while on the other, it did not allow for theﬂexibility that a text generation system requires in the general case.For example,Ana needed to have separate entries in its grammar for two quite similar phrases:opened strongly and opened weakly.Another system that made extensive use of phrasal collocations was FOG [6].This was a highly successful system which generated bilingual(French and English)weather reports that contained a multitude of canned phrases such as (5).(5)Temperatures indicate previous day’s high and overnight low to8a.m.In general,canned phrases fall into the category of phrasal templates. They are usually highly cohesive and the algorithms that can generate them from their constituent words are expensive and sophisticated.15.5.2Text generation using automatically acquired col-locational knowledgeSmadja and McKeown[39]have discussed the use of(automatically retrieved) collocations in text generation.10。

金属材料在外力作用下抵抗永久变形和断裂的能力称为强度

金属材料在外力作用下抵抗永久变形和断裂的能力称为强度。

按外力作用的性质不同，主要有屈服强度、抗拉强度、抗压强度、抗弯强度等，工程常用的是屈服强度和抗拉强度，这两个强度指标可通过拉伸试验测出强度是指零件承受载荷后抵抗发生断裂或超过容许限度的残余变形的能力。

也就是说，强度是衡量零件本身承载能力（即抵抗失效能力）的重要指标。

强度是机械零部件首先应满足的基本要求。

机械零件的强度一般可以分为静强度、疲劳强度（弯曲疲劳和接触疲劳等）、断裂强度、冲击强度、高温和低温强度、在腐蚀条件下的强度和蠕变、胶合强度等项目。

强度的试验研究是综合性的研究，主要是通过其应力状态来研究零部件的受力状况以及预测破坏失效的条件和时机。

强度是指材料承受外力而不被破坏(不可恢复的变形也属被破坏)的能力.根据受力种类的不同分为以下几种:(1)抗压强度--材料承受压力的能力.(2)抗拉强度--材料承受拉力的能力.(3)抗弯强度--材料对致弯外力的承受能力(4)抗剪强度--材料承受剪切力的能力.材料局部抵抗硬物压入其表面的能力称为硬度。

早在1822年，Friedrich mohs提出用10种矿物来衡量世界上最硬的和最软的物体，这是所谓的摩氏硬度计。

按照他们的软硬程度分为十级：1）滑石2）石膏3）方解石4）萤石5）磷灰石6）正长石7）石英8）黄玉9）刚玉）金刚石试验钢铁硬度的最普通方法是用锉刀在工件边缘上锉擦,由其表面所呈现的擦痕深浅以判定其硬度的高低。

这种方法称为锉试法这种方法不太科学。

用硬度试验机来试验比较准确,是现代试验硬度常用的方法。

常用的硬度测定方法有布氏硬度、洛氏硬度和维氏硬度等测试方法硬度是衡量金属材料软硬程度的一项重要的性能指标，它既可理解为是材料抵抗弹性变形、塑性变形或破坏的能力，也可表述为材料抵抗残余变形和反破坏的能力。

硬度不是一个简单的物理概念，而是材料弹性、塑性、强度和韧性等力学性能的综合指标。

硬度试验根据其测试方法的不同可分为静压法（如布氏硬度、洛氏硬度、维氏硬度等）、划痕法（如莫氏硬度）、回跳法（如肖氏硬度）及显微硬度、高温硬度等多种方法。

心理应激

第三节
一、概念
应激反应
当个体觉察应激源的威胁后，就会通过心理和生理中介机制产生心理、生理反应，这种变化称为应激反应。
1.应激的心理反应
可分为积极的心理反应和消极的心理反应。积极的心理反应是指适度的觉醒水平，注意力集中，积极的思维和动机调整及适度的情绪紧张度。消极的心理反应包括过度警觉导致的紧张焦虑、过低或过高的情绪张力，兴趣降低，放弃责任等。包括：（1）认识反应（2）情绪反应（3）行为反应（4）自我防御反应
应激处理对策
由于现代应激学说是心身障碍的主要理论基础，因此，应激处理对策也就成为干预心身障碍的重要手段。良好的应激处理模式可以有效地降低应激的强度来维护心身健康，这种处理模式的核心称为“重组”（reorganize），包括再思（rethink）、降低（reduce）、放松。 1.再思也即换一个角度看待问题。 2.降低即降低应激源的影响。主要措施包括消除、回避、改变。 3.放松主要指心理放松，使思维和情绪恢复平静。 4.释放应激使机体儿茶酚胺大量释放，能量动员，扰乱机体内稳态从而损害机体健康。 5.重组重组是指将上述各种手段结合起来，重新改建新的生活方式。
二、应对的分类
从应对活动的主体角度看，应对涉及个体的心理活动（如再评价）、行为操作（如回避）和躯体变化（如放松）；从应对活动和应激过程的关系看，应对涉及应激各个环节，包括生活事件、认知评价、社会支持和心身反应；从应对活动的指向性来看，有针对问题的应对和针对情绪的应对。 1. lazaruas的分类 lazaruas等（1980年）对应对提出了三种基本类型：①积极的认知应对；②积极的行为应对；③回避应对。 2. Folkman 和Lazarus的分类 Folkman 和Lazarus (1966 年)提出应对类型分为问题指向性应对（problem-focused coping）和情绪指向性应对（Emotion-focused coping）。 3. Moos和Schaefer的分类分为认知性和行为性两类，然后考虑应对取向性因素，出认知探索型、行为探索型、认知回避型、行为回避型四大类。

最快最简捷的下载券获取方式

最快最简捷的下载券获取方式：
1、利用财富兑换下载券：
据文库官网的声明，此次下载文档方式的变更，其目地在于打击恶意赚取财富进行倒卖活动的行为，有力保护贡献用户的合法权益。

因此对于文库贡献者而言，此次调整将不会受到影响。

可以利用财富兑换下载券，两者具有相同的价值。

2、登陆百度文库，点击页面右上角的“文库开启下载新时代”连接即可进入活动界面。

在此界面中，我们可以通过参加活动来获取下载券。

3、通过上传文档来获取更多下载券。

在文库主页中点击“上传我的文档”按钮。

当有人想要下载你上传的文档时，就会支付一定的下载券或财富值啦。

4、还有一种赚取财富值的方法，就是完成“每日任务”：
每日奖励：成功上传一篇文档经验值+3 财富值+3
每周奖励：一周内累计上传四天财富值+15
一周内累计上传七天财富值+30。

二年级上册综合实践活动教案_百度文库

改进的方法：
小组成员共同制作花篮。四、小组合作制作花篮
1、学生自由组合，3——5名同学组成一个小组，大家共同配合，制作花篮。 2、教师巡视指导学生所制作的花篮，并对学生有疑问的地方进行指导。五、学生作品展示
1、各小组推荐一名代表上台展示自己的花篮。 2、学生评选最具创意的花篮，评出合作最默契的小组。六、教师小结...(223.5K)使用下载券下载免下载券下载兑换后下载免下载券下载您共有100财富值，可兑换：
同学们今天的表现都很棒，小组成员之间都能在组长的带领下分工合作，这是一种十分优秀的品质，历史上很多优秀的成就都来源于团队成员之间的精诚合作，还有的小组在制作花篮的过程中花了许多心思，除了按照老师所讲述的步骤做好花篮外，还能加入自己的想象，有人说创新是科学的灵魂。老师相信：只要同学们在做任何事情之前都仔细动脑思考就一定会拥有成功的。
学内容小小发明家（2）
教学时间周次星期 5 总课时 4 教学目标在老师的引导下，小组合作制作花篮。培养学生团结协作意识和创新意识。教学重点及难点
通过自己的动手操作，制作一个漂亮的花篮。教学准备及手段剪刀、卡纸、彩纸、胶水教学流程学生活动一、激趣导入
十字形：长、宽=2厘米 2、用橡皮泥做一个物件，使它能从不同的方向穿过这三个孔。 3、自制壁挂花篮材料与工具：雪碧饮料瓶两个，胶水、刻刀、剪刀。
三、具体制作的方法： 1、将一只雪碧饮料瓶的绿色底套取下，剪成莲花状，翻转向下和瓶身粘面底座。 2、在绿色底套上截取2厘米宽的绿色环，套在瓶身上。
免费四年级上册综合实践活动... 33页免费六年级上册综合实践活动... 23页免费五年级上册综合实践活动... 19页免费

百度文库文档下载不了怎么办

百度文库文档下载不了怎么办
相信大家在百度文库找到自己想要的文档后，很多人就会想要把它下载到我们的电脑上慢慢查阅，可是下载的时候会有很多突发情况导致下载失败。

那么百度文库文档下载不了怎么办？中网优视为您具体分析。

百度文库下载文档需要满足以下条件：
1、登录正常
使用百度文库以前，您需要登录百度账号，并且要确保您的账号是正常未被封禁的才能够正常的下载。

2、下载券不足
如果要下载要付费的文档，那么账户所拥有的文库下载券必须能够满足所下载的文档的标价，若下载券不足可以在下载时实时兑换。

例如：下载一份标价为4张下载券的文档，下载前，需要至少拥有4张下载券或兑换4张下载券所需的财富值。

大家可以通过不定期举行的活动提前兑换下载券，或者是在下载文档的时候，实时使用财富值兑换所需下载券。

3、财富值不足
百度文库下载付费文档财富值的情况也是非常常见的，这时候用户可以购买阅读会员，不同时长的阅读会员会赠送您每个月不同数量的免费下载特权。

4、下载常见问题
为什么会下载失败或下载后无法阅读？
有可能是以下几种情况导致无法下载或下载后的文档无法正常使用：
a)下载券或财富值不足；
b) 使用了迅雷、快车等下载软件或以此类软件为内核的下载工具；
c) 下载频率过快导致系统限制；
d) 杀毒软件更改了下载后的文档；
e) 打开word文档失败，提示“word无法启动转换器mswrd632 wpc”
那么百度文库文档下载不了怎么办？中网优视小编认为，我们要解决下载的问题，首先要找到为什么不能下载的原因。

其实只要多加注意，防止以上问题出现，基本都会很顺利的下载。

希望以上内容能帮到大家。

海水的运动

海水的运动海水运动的形式主要是波浪、潮汐和洋流。

（一）波浪波浪就是海水质点在它的平衡位置附近产生一种周期性的振动运动和能量的传播。

波浪运动只是波形的向前传播，水质点并没有随波前进，这就是波浪运动的实质。

这是由于水质点同时受到动力和复原力这两个互相垂直的力共同作用的结果。

动力，如风力、潮汐、地震或局部大气压力的变动等，使水质点产生水平位移。

复原力（物理学称为弹性力），如重力、水压力和表面张力等，使水质点恢复原位。

因此，水质点在动力的作用下产生水平位移的同时，受复原力的作用有恢复原位的趋势而产生垂直运动，这样水质点便沿着上述两个力的合力方向运动的结果，便在它的平衡位置附近产生了一种周期性的圆周运动。

而运动着的水质点又将它所获得的能量依次相传，于是连续的“能流”就随波前进。

故波浪只是形状的前进，水质点并没有随波前进。

1．波浪要素波浪的大小和形状是用波浪要素来说明的。

波浪的基本要素有：波峰、波顶、波谷、波底、波高、波长、周期、波速、波向线和波峰线等（图5．33）。

波峰是静水面以上的波浪部分。

波顶是波峰的最高点。

波谷是静水面以下的波浪部分。

波底是波谷的最低点。

波高h，是波顶与波底之间的垂直距离。

波长λ，是相邻波顶（或波底）间的水平距离。

周期τ，是相邻波顶（或波底）2．波浪分类波浪的种类很多，这里介绍几种主要的分类方法：（1）按成因分类风浪和涌浪：在风力的直接作用下形成的波浪，称为风浪；当风停止，或当波浪离开风区时，这时的波浪便称为涌浪。

两者的性质、波形、波高与波长、波速等都不同。

风浪的性质属于强制波，其波形的轮廓和余摆线差别大，波峰尖陡，波谷平广，海面凹凸不平，此起彼伏；其波高较高，波长较短；波速较慢，最大仅达40～50km／h。

而涌浪的性质是属于自由波，其波形的轮廓和余摆线较接近，波峰圆滑，海面较规则，波浪呈一排排的样子，其波高较矮，波长较长（可达500m至600m，甚至800m以上），波速较快，每小时能达100多km，故可以比风速大，可利用它来预报台风或风暴。

ASTM A376-02

Designation:A376/A376M–02a Used in USDOE-NE standards Standard Speciﬁcation forSeamless Austenitic Steel Pipe for High-TemperatureCentral-Station Service1This standard is issued under theﬁxed designation A376/A376M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope*1.1This speciﬁcation2covers seamless austenitic steel pipe intended for high-temperature central-station service.Among the grades covered areﬁve H grades and two nitrogen grades (304N and316N)that are speciﬁcally intended for high-temperature service.1.2Optional supplementary requirements(S1through S10) are provided.These supplementary requirements specify addi-tional tests that will be made only when stated in the order, together with the number of such tests required.1.3Grades TP321and TP321H have lower strength require-ments for nominal wall thicknesses greater than3⁄8in.[9.5 mm].1.4The values stated in either inch-pound units or SI units are to be regarded separately as standard.Within the text,the SI units are shown in brackets.The values stated in each system are not exact equivalents;therefore,each system must be used independently of the bining values from the two systems may result in nonconformance with the speciﬁ-cation.The inch-pound units shall apply unless the“M”designation of this speciﬁcation is speciﬁed in the order.N OTE1—The dimensionless designator NPS(nominal pipe size)has been substituted in this standard for such traditional terms as“nominal diameter,”“size,”and“nominal size.”2.Referenced Documents2.1ASTM Standards:A262Practices for Detecting Susceptibility to Intergranu-lar Attack in Austenitic Stainless Steels3A941Terminology Relating to Steel,Stainless Steel,Re-lated Alloys,and Ferroalloys4A999/A999M Speciﬁcation for General Requirements for Alloy and Stainless Steel Pipe4E112Test Methods for Determining Average Grain Size5 E213Practice for Ultrasonic Examination of Metal Pipe and Tubing6E381Method of Macroetch Testing Steel Bars,Billets, Blooms,and Forgings5E426Practice for Electromagnetic(Eddy-Current)Exami-nation of Seamless and Welded Tubular Products,Austen-itic Stainless Steel,and Similar Alloys62.2ASME Boiler and Pressure Vessel Code:Section IX Welding Qualiﬁcations72.3Other Standards:SNT-TC-1A Personnel Qualiﬁcation and Certiﬁcation in Nondestructive Testing83.Terminology3.1Deﬁnitions—For deﬁnitions of terms used in this speci-ﬁcation,refer to Terminology A941.4.Ordering Information4.1Orders for material to this speciﬁcation should include the following,as required to describe the desired material adequately:4.1.1Quantity(feet,centimetres,or number of lengths), 4.1.2Name of material(seamless austenitic steel pipe), 4.1.3Grade(Table1),4.1.4Size(nominal size,or outside diameter and schedule number or average wall thickness),4.1.5Lengths(speciﬁc or random),(Permissible Variations in Length Section of Speciﬁcation A999/A999M),4.1.6Endﬁnish(Ends Section of Speciﬁcation A999/ A999M),4.1.7Optional requirements(Section9)(see Hydrostatic Test Requirements Section and the Permissible Variation in Weight for Seamless Pipe Section for weighing individual lengths,of Speciﬁcation A999/A999M),(see10.6,repairing by welding;14.3,die stamping),1This speciﬁcation is under the jurisdiction of ASTM Committee A01on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.10on Stainless and Alloy Steel Tubular Products.Current edition approved Sept.10,2002.Published October2002.Originally published as A376–st previous edition A376/A376M–02.2For ASME Boiler and Pressure Vessel Code applications see related Speciﬁ-cation SA-376in Section II of that Code.3Annual Book of ASTM Standards,V ol01.03.4Annual Book of ASTM Standards,V ol01.01.5Annual Book of ASTM Standards,V ol03.01.6Annual Book of ASTM Standards,V ol03.03.7Available from American Society of Mechanical Engineers(ASME Interna-tional),Three Park Ave.,New York,NY10016-5990.8Available from the American Society for Nondestructive Testing,P.O.Box 28518,1711Arlingate Ln.,Columbus,OH43228-0518.1*A Summary of Changes section appears at the end of this standard. Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.4.1.8Test report required (Certiﬁcation Section of Speciﬁ-cation A 999/A 999M),4.1.9Speciﬁcation designation,and4.1.10Special requirements or any supplementary require-ments selected,or both.5.General Requirements5.1Material furnished to this speciﬁcation shall conform to the applicable requirements of the current edition of Speciﬁ-cation A 999/A 999M unless otherwise provided herein.6.Materials and Manufacture6.1Manufacture —At the manufacturer’s option,pipe may be either hot ﬁnished or cold ﬁnished,with a suitable ﬁnishing treatment,where necessary.6.2Heat Treatment :6.2.1All pipe shall be furnished in the heat-treated condi-tion unless the order speciﬁcally states that no ﬁnal heat treatment shall be applied.When the order is furnished without ﬁnal heat treatment,each pipe shall be stenciled “HT-O.”6.2.2As an alternate to ﬁnal heat treatment in a continuous furnace or batch-type furnace,immediately following hot forming while the temperature of the pipes is not less than the speciﬁed minimum solution treatment temperature,pipes may be individually quenched in water or rapidly cooled by other means.6.2.3Grades TP304,TP304N,TP304LN,TP316,TP316N,TP316LN,TP321,TP347,TP348,16-8-2H,S 31725,and S 31726—Unless otherwise stated in the order,heat treatment shall consist of heating to a minimum temperature of 1900°F [1040°C]and quenching in water or rapidly cooling by other means. 6.2.3.1The purchaser may specify controlled structural or special service characteristics which shall be used as a guide for the most suitable heat treatment.If the ﬁnal heat treatment is at a temperature under 1900°F [1040°C],each pipe shall be stenciled with the ﬁnal heat treatment temperature in degrees Fahrenheit or Celsius after the suffix “HT.”6.2.4Grades TP304H,TP316H,TP321H,TP347H,and 16-8-2H —If cold working is involved in processing,the minimum solution-treating temperature for Grades TP321H and TP347H shall be 2000°F [1100°C],for Grades TP304H and TP316H,1900°F [1040°C],and for Grade 16-8-2H,1800°F [980°C].If the material is hot-rolled,the minimum solution-treating temperatures for Grades TP321H and TP347H shall be 1925°F [1050°C],for Grades TP304H and TP316H,1900°F [1040°C],and for Grade 16-8-2H,1800°F [980°C].6.2.5Grade S34565—Heat treatment shall consist of heat-ing to a temperature in the range of 2050°F [1120°C]minimum and 2140°F [1170°C]maximum,and quenching in water or rapidly cooling by other means.6.3A solution annealing temperature above 1950°F [1065°C]may impair the resistance to intergranular corrosion after subsequent exposure to sensitizing conditions in TP321,TP321H,TP347,TP347H,TP348,and TP348H.When speci-ﬁed by the purchaser,a lower temperature stabilization or re-solution anneal shall be used subsequent to the initial high temperature solution anneal (see Supplementary Requirement S9).6.4The grain size of grades 304H,316H,321H,and 347H,as determined in accordance with Test Methods E 112,shall be No.7or coarser.TABLE 1Chemical RequirementsGradeUNS Desig-nationComposition,%CarbonMan-ganese,max Phos-phorus,maxSul-fur,max Sili-con,max NickelChromiumMolyb-denum Tita-nium Colum-bium Tan-talum Nitro-gen AOthersTP304S304000.08max 2.000.0450.0300.758.0–11.018.0–20.0..................TP304H S304090.04–0.10 2.000.0450.0300.758.0–11.018.0–20.0..................TP304N S304510.08max 2.000.0450.0300.758.0–11.018.0–20.0............0.10–0.16...TP304LN S304530.035max 2.000.0450.0300.758.0–11.018.0–20.0............0.10–0.16...TP316S316000.08max 2.000.0450.0300.7511.0–14.016.0–18.0 2.00–3.00...............TP316H S316090.04–0.10 2.000.0450.0300.7511.0–14.016.0–18.0 2.00–3.00...............TP316N S316510.08max 2.000.0450.0300.7511.0–14.016.0–18.0 2.00–3.00.........0.10–0.16...TP316LN S316530.035max 2.000.0450.0300.7511.0–14.016.0–18.0 2.00–3.00.........0.10–0.16...TP321S321000.08max 2.000.0450.0300.759.0–13.017.0–19.0...B ............TP321H S321090.04–0.10 2.000.0450.0300.759.0–13.017.0–19.0...C............TP347S347000.08max 2.000.0450.0300.759.0–13.017.0–19.0......D .........TP347H S347090.04–0.10 2.000.0450.0300.759.0–13.017.0–19.0......E .........TP348F S348000.08max 2.000.0450.0300.759.0–13.017.0–19.0......D0.10...Co 0.20max16-8-2H S168000.05–0.10 2.000.0450.0300.757.5–9.514.5–16.5 1.50–2.00..................S317250.030max 2.000.0450.0300.7513.5–17.518.0–20.0 4.0–5.0.........0.20max Cu 0.75max ...S317260.030max 2.000.0450.0300.7514.5–17.517.0–20.0 4.0–5.0.........0.10–0.20Cu 0.75max ...S345650.030max 5.0–7.00.0300.0101.016.0–18.023.0–25.04.0–5.0.........0.040–0.060Cb 0.10maxA The method of analysis for nitrogen shall be a matter of agreement between the purchaser and manufacturer.BThe titanium content shall be not less than ﬁve times the carbon content and not more than 0.70%.CThe titanium content shall be not less than four times the carbon content and not more than 0.70%.DThe columbium content shall be not less than ten times the carbon content and not more than 1.10%.EThe columbium content shall be not less than eight times the carbon content and not more than 1.10%.FThis grade is intended for special purposeapplications.7.Chemical Composition7.1The steel shall conform to the requirements as to chemical composition prescribed in Table 1.8.Product Analysis8.1At the request of the purchaser,an analysis of one billet from each heat or two pipes from each lot (Note 2)shall be made by the manufacturer.A lot of pipe shall consist of the following:NPS Designator Lengths of Pipe in Lot Under NPS 2400or fraction thereof NPS 2to NPS 5,incl 200or fraction thereof Over NPS 5100or fraction thereofN OTE 2—A lot shall consist of the number of lengths speciﬁed in 8.1of the same size and wall thickness from any one heat of steel.8.2The results of these analyses shall be reported to the purchaser or the purchaser’s representative,and shall conform to the requirements speciﬁed in Table 1.8.3If the analysis of one of the tests speciﬁed in Section 9does not conform to the requirements speciﬁed in Section 7,an analysis of each billet or pipe from the same heat or lot may be made,and all billets or pipe conforming to the requirements shall be accepted.9.Tensile Requirements9.1The material shall conform to the requirements as to tensile properties prescribed in Table 2.10.Workmanship,Finish,and Appearance10.1The pipe manufacturer shall explore a sufficient num-ber of visual surface imperfections to provide reasonable assurance that they have been properly evaluated with respect to depth.Exploration of all surface imperfections is not required but may be necessary to assure compliance with 10.2.10.2Surface imperfections that penetrate more than 121⁄2%of the nominal wall thickness or encroach on the minimum wall thickness shall be considered defects.Pipe with such defects shall be given one of the following dispositions:10.2.1The defect may be removed by grinding provided that the remaining wall thickness is within speciﬁed limits.10.2.2Repaired in accordance with the repair welding provisions of 10.6.10.2.3The section of pipe containing the defect may be cut off within the limits of requirements on length.10.2.4Rejected.10.3To provide a workmanlike ﬁnish and basis for evalu-ating conformance with 10.2,the pipe manufacturer shall remove by grinding the following:10.3.1Mechanical marks,abrasions (see Note 3),and pits,any of which imperfections are deeper than 1⁄16in.[1.6mm].N OTE 3—Marks and abrasions are deﬁned as cable marks,dinges,guide marks,roll marks,ball scratches,scores,die marks,and so forth.10.3.2Visual imperfections commonly referred to as scabs,seams,laps,tears,or slivers found by exploration in accor-dance with 10.1to be deeper than 5%of the nominal wall thickness.10.4At the purchaser’s discretion,pipe shall be subject to rejection if surface imperfections acceptable under 10.2are not scattered,but appear over a large area in excess of what is considered a workmanlike ﬁnish.Disposition of such pipe shall be a matter of agreement between the manufacturer and the purchaser.10.5When imperfections or defects are removed by grind-ing,a smooth curved surface shall be maintained,and the wall thickness shall not be decreased below that permitted by this speciﬁcation.The outside diameter at the point of grinding may be reduced by the amount so removed.10.5.1Wall thickness measurements shall be made with a mechanical caliper or with a properly calibrated nondestructive testing device of appropriate accuracy.In case of dispute,the measurement determined by use of the mechanical caliper shall govern.10.6Weld repair shall be permitted only subject to the approval of the purchaser and in accordance with Speciﬁcation A 999/A 999M.10.7The ﬁnished pipe shall be reasonably straight.10.8The pipe shall be free of scale and contaminating iron particles.Pickling,blasting,or surface ﬁnishing is not manda-tory when pipe is bright annealed.The purchaser may request that a passivating treatment be applied.11.Hydrostatic or Nondestructive Electric Test11.1Each pipe shall be subjected to the Nondestructive Electric Test or the Hydrostatic Test.Unless speciﬁed by the purchaser,either test may be used at the option of the producer.11.2Hydrostatic Test —Each length of ﬁnished pipe shall be subjected to the hydrostatic test in accordance with Speci-ﬁcation A 999/A 999M,unless speciﬁcally exempted under the provisions of 11.3and 11.4.11.3For pipe sizes NPS 24and over,the purchaser,with the agreement of the manufacturer,may complete the hydrostatic test requirement with the system pressure test,which may beTABLE 2Tensile RequirementsGradeTensile A strength,min,ksi [MPa]Yield strength min,ksi[MPa]Elongation in 2in.or 50mm (or 4D)min,%LongitudinalTransverse TP304,TP304H,TP304LN,TP316,TP316H,TP316LN,TP347,TP347H,TP348,16-8-2H,S3172575[515]30[205]3525TP304N,TP316N,S3172680[550]35[240]3525S34565115[790]60[415]3530TP321,321H #3⁄8975[515]30[205]3525>3⁄89B70[480]25[170]3525A†For grade TP304,NPS8or larger,and in schedules 140and heavier,the required minimum tensile strength shall be 70ksi [480MPa].BPrior to the issuance of A 376/A 376M –88,the tensile and yield strength values were 75[520]and 30[210]respectively,for nominal wall greater than 3⁄8in.[9.5mm].†Editoriallycorrected.lower or higher than the speciﬁcation test pressure,but in no case shall the test pressure be lower than the system design pressure.Each length of pipe furnished without the completed manufacturer’s hydrostatic test shall include with the manda-tory marking the letters“NH.”11.4Nondestructive Examination—Each pipe shall be ex-amined with a nondestructive test in accordance with Practice E213or Practice E426.Unless speciﬁcally called out by the purchaser,the selection of the nondestructive electric test will be at the option of the manufacturer.The range of pipe sizes that may be examined by each method shall be subject to the limitations in the scope of the respective practices.11.4.1The following information is for the beneﬁt of the user of this speciﬁcation:11.4.1.1The reference standards deﬁned in11.10.1through 11.10.4are convenient standards for calibration of nondestruc-tive testing equipment.The dimensions of these standards should not be construed as the minimum size imperfection detectable by such equipment.11.4.1.2The ultrasonic testing(UT)can be performed to detect both longitudinally and circumferentially oriented de-fects.It should be recognized that different techniques should be employed to detect differently oriented imperfections.The examination may not detect short,deep,defects.11.4.1.3The eddy-current testing(ET)referenced in Prac-tice E426has the capability of detecting signiﬁcant disconti-nuities,especially the short abrupt type.11.4.1.4A purchaser interested in ascertaining the nature (type,size,location,and orientation)of discontinuities that can be detected in the speciﬁc application of these examinations should discuss this with the manufacturer of the tubular product.11.5Time of Examination—Nondestructive testing for speciﬁcation acceptance shall be performed after all mechani-cal processing,heat treatments,and straightening operations. This requirement does not preclude additional testing at earlier stages in the processing.11.6Surface Condition:11.6.1All surfaces shall be free of scale,dirt,grease,paint, or other foreign material that could interfere with interpretation of test results.The methods used for cleaning and preparing the surfaces for examination shall not be detrimental to the base metal or the surfaceﬁnish.11.6.2Excessive surface roughness or deep scratches can produce signals that interfere with the test.11.7Extent of Examination:11.7.1The relative motion of the pipe and the transducer(s), coil(s),or sensor(s)shall be such that the entire pipe surface is scanned,except as in6.2.11.7.2The existence of end effects is recognized,and the extent of such effects shall be determined by the manufacturer, and,if requested,shall be reported to the purchaser.Other nondestructive tests may be applied to the end areas,subject to agreement between the purchaser and the manufacturer. 11.8Operator Qualiﬁcations—The test unit operator shall be certiﬁed in accordance with SNT-TC-1A,or an equivalent recognized and documented standard.11.9Test Conditions:11.9.1For eddy-current testing,the excitation coil fre-quency shall be chosen to ensure adequate penetration yet provide good signal-to-noise ratio.11.9.2The maximum eddy-current coil frequency used shall be as follows:On speciﬁed walls up to0.050in.—100KHz maxOn speciﬁed walls up to0.150in.—50KHz maxOn speciﬁed walls up to0.150in.—10KHz max11.9.3Ultrasonic—For examination by the ultrasonic method,the minimum nominal transducer frequency shall be 2.00MHz and the maximum nominal transducer size shall be 1.5in.11.9.3.1If the equipment contains a reject noticeﬁlter setting,this shall remain off during calibration and testing unless linearity can be demonstrated at that setting.11.10Reference Standards:11.10.1Reference standards of convenient length shall be prepared from a length of pipe of the same grade,size(NPS,or outside diameter and schedule or wall thickness),surface ﬁnish,and heat treatment condition as the pipe to be examined.11.10.2For Ultrasonic Testing,the reference ID and OD notches shall be any one of the three common notch shapes shown in Practice E213,at the option of the manufacturer.The depth of each notch shall not exceed121⁄2%of the speciﬁed nominal wall thickness of the pipe or0.004in.,whichever is greater.The width of the notch shall not exceed twice the depth.Notches shall be placed on both the OD and ID surfaces.11.10.3For Eddy-Current Testing,the reference standard shall contain,at the option of the manufacturer,any one of the following discontinuities:11.10.3.1Drilled Hole—The reference standard shall con-tain three or more holes,equally spaced circumferentially around the pipe and longitudinally separated by a sufficient distance to allow distinct identiﬁcation of the signal from each hole.The holes shall be drilled radially and completely through the pipe wall,with care being taken to avoid distortion of the pipe while drilling.One hole shall be drilled in the weld,if visible.Alternately,the producer of welded pipe may choose to drill one hole in the weld and run the calibration standard through the test coils three times with the weld turned at120°on each pass.The hole diameter shall vary with NPS as follows:NPS Designator Hole Diameter0.039in.(1mm)above1⁄2to11⁄40.055in.(1.4mm)above11⁄4to20.071in.(1.8mm)above2to50.087in.(2.2mm)above50.106in.(2.7mm)11.10.3.2Transverse Tangential Notch—Using a round tool orﬁle with a1⁄4-in.(6.4-mm)diameter,a notch shall beﬁled or milled tangential to the surface and transverse to the longitu-dinal axis of the pipe.Said notch shall have a depth not exceeding121⁄2%of the speciﬁed nominal wall thickness of the pipe or0.004in.(0.102mm),whichever is greater.11.10.3.3Longitudinal Notch—A notch0.031in.or less in width shall be machined in a radial plane parallel to the tube axis on the outside surface of the pipe,to have a depth not exceeding121⁄2%of the speciﬁed wall thickness of the pipeor0.004in.,whichever is greater.The length of the notch shall be compatible with the testing method.11.10.3.4More or smaller reference discontinuities,or both, may be used by agreement between the purchaser and the manufacturer.11.11Standardization Procedure:11.11.1The test apparatus shall be standardized at the beginning and end of each series of pipes of the same size (NPS or diameter and schedule or wall thickness),grade and heat treatment condition,and at intervals not exceeding4h. More frequent standardization may be performed at the manu-facturer’s option or may be required upon agreement between the purchaser and the manufacturer.11.11.2The test apparatus shall also be standardized after any change in test system settings;change of operator;equip-ment repair;or interruption due to power loss,process shut-down,or when a problem is suspected.11.11.3The reference standard shall be passed through the test apparatus at the same speed and test system settings as the pipe to be tested.11.11.4The signal-to-noise ratio for the reference standard shall be21⁄2to1or greater.Extraneous signals caused by identiﬁable causes such as dings,scratches,dents,straightener marks,and so forth,shall not be considered noise.The rejection amplitude shall be adjusted to be at least50%of full scale of the readout display.11.11.5If upon any standardization,the rejection amplitude has decreased by29%(3dB)of peak height from the last standardization,the pipe since the last calibration shall be rejected.The test system settings may be changed,or the transducer(s),coil(s)or sensor(s)adjusted,and the unit restan-dardized,but all pipe tested since the last acceptable standard-ization must be retested for acceptance.11.12Evaluation of Imperfections:11.12.1Pipes producing a signal equal to or greater than the lowest signal produced by the reference standard(s)shall be identiﬁed and separated from the acceptable pipes.The area producing the signal may be reexamined.11.12.2Such pipes shall be rejected if the test signal was produced by imperfections that cannot be identiﬁed or was produced by cracks or crack-like imperfections.These pipes may be repaired in accordance with Sections13and14.To be accepted,a repaired pipe must pass the same nondestructive test by which it was rejected,and it must meet the minimum wall thickness requirements of this speciﬁcation.11.12.3If the test signals were produced by visual imper-fections such as:(1)Scratches,(2)Surface roughness,(3)Dings,(4)Straightener marks,(5)Cutting chips,(6)Steel die stamps,(7)Stop marks,or(8)Pipe reducer ripple.The pipe may be accepted based on visual examination provided the imperfection is less than0.004in.(0.1mm)or 121⁄2%of the speciﬁed wall thickness(whichever is greater).11.12.4Rejected pipe may be reconditioned and retested providing the wall thickness is not decreased to less than that required by this or the product speciﬁcation.The outside diameter at the point of grinding may be reduced by the amount so removed.To be accepted,retested pipe shall meet the test requirement.11.12.5If the imperfection is explored to the extent that it can be identiﬁed as non-rejectable,the pipe may be accepted without further test providing the imperfection does not en-croach on the minimum wall thickness.12.Mechanical Tests Required12.1Transverse or Longitudinal Tension Test—The tension test shall be performed on1%of the pipe from each lot.N OTE4—The term“lot”applies to all pipe of the same nominal size and wall thickness(or schedule)which is produced from the same heat of steel and subjected to the sameﬁnishing treatment in a continuous furnace or by directly obtaining the heat treated condition by quenching after hot forming.Whenﬁnal heat treatment is in a batch-type furnace,the lot shall include only that pipe which is heat treated in the same furnace charge.12.2Flattening Test—For pipe heat treated in a batch-type furnace,theﬂattening test shall be made on5%of the pipe from each heat-treated lot(see Note4).When heat treated by the continuous process or when treated condition is obtained directly by quenching after hot forming,this test shall be made on a sufficient number of pipe to constitute5%of the lot(Note 4)but in no case less than two pipes.13.Certiﬁcation13.1In addition to the certiﬁcation required by Speciﬁcation A999/A999M,the certiﬁcation for pipe furnished to this speciﬁcation shall identify each length of pipe which is furnished without the manufacturer’s completed hydrostatic test,in accordance with11.3.14.Product Marking14.1In addition to the marking prescribed in Speciﬁcation A999/A999M,the marking shall include the length,hydro-static test pressure,the ANSI schedule number,the heat number or manufacturer’s number by which the heat can be identiﬁed,the marking requirements of6.2,and,if applicable, NH when hydrotesting is not performed and ET when eddy-current testing is performed,or UT when ultrasonic testing is performed.14.2If the pipe conforms to any of the supplementary requirements speciﬁed in S1through S10,compliance shall be so indicated by adding the symbol“S”directly followed by the number of the applicable supplementary requirement to the marking prescribed in14.1.14.3No steel indentation stamping shall be done without the purchaser’s consent.15.Keywords15.1austenitic stainless steel;feedwater heater tubes;stain-less steel tube;steel tube;welded steeltubeSUPPLEMENTARY REQUIREMENTSFOR PIPE REQUIRING SPECIAL CONSIDERATION One or more of the following supplementary requirements shall apply only when speciﬁed in the purchase order.The purchaser may specify a different frequency of test or analysis than is provided in the supplementary requirement.Subject to agreement between the purchaser and manufacturer, retest and retreatment provisions of these supplementary requirements may also be modiﬁed.S1.Product AnalysisS1.1Product analysis shall be made on each length of pipe. Individual lengths failing to conform to the chemical compo-sition requirements shall be rejected.S2.Transverse Tension TestsS2.1A transverse tension test shall be made on a specimen from one end or both ends of each pipe NPS8and over in nominal diameter.If this supplementary requirement is speci-ﬁed,the number of tests per pipe shall also be speciﬁed.If a specimen from any length fails to meet the required tensile properties(tensile,yield,and elongation),that length shall be rejected subject to retreatment in accordance with Speciﬁcation A999/A999M and satisfactory retest.S3.Flattening TestS3.1Theﬂattening test of Speciﬁcation A999/A999M shall be made on a specimen from one end or both ends of each pipe.Crop ends may be used.If this supplementary require-ment is speciﬁed,the number of tests per pipe shall also be speciﬁed.If a specimen from any length fails because of lack of ductility prior to satisfactory completion of theﬁrst step of theﬂattening test requirement that pipe shall be rejected subject to retreatment in accordance with Speciﬁcation A999/ A999M and satisfactory retest.If a specimen from any length of pipe fails because of a lack of soundness that length shall be rejected,unless subsequent retesting indicates that the remain-ing length is sound.S4.Etching TestsS4.1The steel shall be homogeneous as shown by etching tests conducted in accordance with the appropriate portions of Method E381.Etching tests shall be made on a cross section from one end or both ends of each pipe and shall show sound and reasonably uniform material free from injurious lamina-tions,cracks,and similar objectionable defects.If this supple-mentary requirement is speciﬁed,the number of tests per pipe required shall also be speciﬁed.If a specimen from any length shows objectionable defects,the length shall be rejected, subject to removal of the defective end and subsequent retests indicating the remainder of the length to be sound and reasonably uniform material.S5.PhotomicrographsS5.1Photomicrographs at100diameters may be made from one end of each piece of pipe furnished in sizes6in.[152mm] and larger in the as-furnished condition.Such photomicro-graphs shall be suitably identiﬁed as to pipe size,wall thickness,piece number,and heat.Such photomicrographs are for information only,and shall show the actual metal structure of the pipe asﬁnished.S6.Ultrasonic TestS6.1Each piece of pipe may be ultrasonically tested to determine its soundness throughout the entire length of the pipe.Each piece shall be ultrasonically tested in a circumfer-ential direction in such a manner that the entire piece is scanned by the ultrasonic beam.The calibration standard shall be prepared from a section of pipe which has two notches,one in the inside surface and one in the outside surface.The notches shall be at least11⁄2-in.[38-mm]long and have a depth of3% of the wall thickness,or0.004in.[0.1mm],whichever is the greater.Any pipe showing an ultrasonic indication of greater amplitude than the amplitude of the indication from the calibration standard shall be subject to rejection.S7.Hot Ductility Test for Indicating WeldabilityS7.1A high-temperature ductility test may be made upon each heat of material supplied in heavy-wall pipe sections.An appropriate specimen shall be heated to an initial temperature, cooled100°F[50°C],then subjected to a tension test,and shall show a minimum reduction of area of60%.The initial temperature is that temperature50°F[30°C]below the tem-perature at which material exhibits zero ductility.Rejection of material shall not be based upon this test.S8.RetestsS8.1Upon the purchaser’s request,retests shall be made from sections of material removed from any part of the pipe. Failure to meet the requirements stated in this speciﬁcation shall be cause for rejection.S9.Stabilization Heat TreatmentS9.1Subsequent to the solution anneal required in 6.4, Grades TP321,TP321H,TP347,TP347H,TP348,and TP348H shall be given a stabilization heat treatment at a temperature lower than that used for the initial solution annealing heat treatment.The temperature of stabilization heat treatment shall be at a temperature as agreed upon between the purchaser and vendor.S10.Intergranular Corrosion TestS10.1When speciﬁed,material shall pass intergranular corrosion tests conducted by the manufacturer in accordance with Practices A262,Practice E.N OTE S10.1—Practice E requires testing on the sensitized condition for low carbon or stabilized grades,and on the as-shipped condition for other grades.S10.2A stabilization heat treatment in accordance with Supplementary Requirement S9may be necessary and is permitted in order to meet this requirement for the grades containing titanium or columbium,particularly in their Hversions.。

French ll

41. Imperfect TenseThis past tense corresponds to "was, were or used to." This tense is used for repeated, continuous, or ongoing actions; as well as for verbs that describe background and circumstances, such as weather, time, and physical, mental, and emotional states. Use the passé composé for actions that happened once and are done. However, verbs that express mental and emotional states that are descriptive in nature are generally used in the imperfect in a past context. These verbs are: aimer, avoir, croire, détester, espérer, être, penser, and préférer. To form the stem, use the nous form of the present tense and drop the -ons. Then add these endings: -ais -ions -ais -iez -ait -aient The only exception is être in which you must use the stem ét-, but still the same endings. Verb stems that end in -c must use a cedilla (ç) under the c to make it soft. Verbs stems endings in -g keep the e before all forms except nous and vous. être étais ay-teh étions ay-tee-ohn étais ay-teh étiez ay-tee-ayétait ay-teh étaient ay-teh commencer commençais commençais commençaitkoh-mawnseh koh-mawnseh koh-mawnsehmangerkoh-mawn-seeohn koh-mawn-seeay koh-mawn-saycommencions commenciez commençaientmangeais mangeais mangeaitmawnzheh mawnzheh mawnzhehmangions mangiez mangeaientmawn-zheeohn mawn-zheeay mawn-zhayAvoir, Devoir, Pouvoir, Savoir, and VouloirThese verbs change meanings, according to whether they are used in the imperfect or the passé composé. Imperfect avoir devoir j'avais je devais I had j'ai eu Passé Composé I got, received I must have, I had to (and did) I was able to (and did), succeededI was supposed to j'ai dû j'ai pupouvoir je pouvais I was capableje n'ai pas pu savoir je savais I knew I wanted to j'ai suI couldn't, failed I found out, discoveredvouloir je voulaisj'ai voulu I tried, decided, insisted je n'ai pas voulu I refusedThe imperfect tense is also used with these constructions:être en train de + infinitive J'étais en train d'étudier quand vous êtes arrivés. I was (in the process of ) studying when you arrived aller + infinitive J'allais sortir quand le téléphone a sonné. venir de + infinitive Je venais de manger, alors je n'avais plus faim. I had just eaten, so I wasn't hungry anymore. I was going to leave when the phone rang.42. Places / Les Endroitsschool bathroom locker drinking fountain store library office stadium cafe cafeteria movie theater church museum pool countryside beach theater park restaurant hospital l'école la toilette le coffre la fontaine le magasin la biblio(thèque) le bureau le stade le café la cafétéria le cinéma l'église le musée la piscine la campagne la plage le théâtre le parc le restaurant l'hôpital lay-kohl twah-lett koh-fruh fohn-ten mahg-ah-zahn beeb-lee-oh(teck) bur-oh stahd kah-fay kah-fay-tay-reeah see-nay-mah lay-glees mew-zay pee-seen kawn-pawn-yuh plahzh tay-ah-truh park res-toh-rawn loh-pee-tahl university bank l'université la banque loon-ee-vair-seetay bahnk gahr air-o-poor tay-lay-fone ah-par-tuh-mawn low-tell vee-lazh lew-zeen zhar-dan shah-toe kah-tay-drahl zoh-oh mon-u-mawn far-mah-see boosh-ree con-feess-reetrain station la gare airport telephone apartment hotel village factory garden castle cathedral zoo bakery monument pharmacy butcher shop police station town hall l'aéroport le téléphone l'appartement l'hôtel le village l'usine le jardin le château la cathédrale le zoo le monument la pharmacie la boucheriela boulangerie boo-lanzh-reecandy store la confiseriela gendarmerie zhan-darm-ree la mairie mair-eepost office home city supermarket delicatessenla poste la maison la ville le supermarché la charcuteriepost may-zohn veel su-per-marshay shar-koot-reesquare bookstore grocery storela place la librairie l'épicerieplahs lee-brair-ee lay-peess-ree pah-teess-ree pwah-son-eh-reepastry shop la pâtisserie fish market la poissonnerie43. Transportationby bike by bus by moped by car by subway on foot by plane by train by boat en vélo (m) en bus (m) en voiture (f) en métro (m) à pied (m) en avion (m) en train (m) en bateau (m) awn vay-low awn boos awn vwah-chur awn moh-toh awn may-troh ah pee-ay awn ah-vee-ohn awn trahn awn bah-tohen mobylette (f) awn moh-bee-lettby motorcycle en moto (f)44. To Want and To Be Able Tovouloir-to want (vool-wahr) veux vuh voulons voo-lohn veux vuh voulez voo-lay pouvoir-to be able to, can (poov-wahr) peux peux peut puh puh puh pouvons pouvez peuvent poo-vohn poo-vay puhvveut vuh veulent vullNote: Voulez-vous? can mean Do you want? or Will you?45. The House / La maisonHouse Appartment Bedroom Hallway Kitchen Storeroom Stairs Floor la maison l'appartement (m) la chambre le couloir la cuisine le débarras l'escalier (m) l'étage (m) meh-zohn ah-part-mawn shawm-bruh kool-wahr kwee-zeen day-bar-ah les-cahl-ee-ay lay-tahzhLiving Room Closet Roomle living/le salon la penderie la piècelee-veeng/sah-lohn pawnd-ree pee-ehss rayd-show-say sahl ah mawn-zhay sahl duh bahn teh-rahss shu-mee-nay twah gah-rahzh root troh-teeay porsh soo-sole kahv gah-zohn bwee-sohn lar-bruhGround Floor le rez-de-chaussée Dining Room la salle à manger Bathroom Attic Chimney Roof Garage Driveway Sidewalk Porch Basement Cellar Lawn/grass Bush/shrub Tree la salle de bains Terrace, patio la terrasse la cheminée le toit le garage la route le trottier le porche le sous-sol la cave le gazon le buisson l'arbre (m)le grenier/la mansarde grun-eeay/mahn-sard46. Furniture / Les meublesShelf Desk Chair Dresser Curtain Window Bed Door Closet Rug Lamp Nightstand Stereo Television VCR Remote Control Computer Radio Fridge Refrigerator Freezer l'étagère (f) le bureau la chaise la commode le rideau la fenêtre le lit la porte le placard le tapis la lampe la table de nuit la chaîne-stéréo la télé(vision) le magnétoscope la télécommande l'ordinateur (m) la radio le frigo le réfrigérateur le congélateur lay-tah-zhehr bewr-oh shehzh koh-mode ree-doh fuh-neh-truh lee port plah-car tah-pee lahmp tah-bluh duh nwee shen-stay-ray-oh tay-lay-vee-zee-ohn mahn-yeht-oh-scope tay-lay-koh-mahnd lor-dee-nah-tur rah-dee-oh free-go ray-free-zhay-rah-tir kon-zhay-lah-tur(Coffee) Table Sink Bathtub Stove Oven Dishwasher Microwave Clothes Dryer Shower Pillow Mirror Ceiling Floor Armchair Clock Bedspread Vase Waste basket Bathroom sink Hair Dryer Couch/Sofa Iron Vacuumla table (basse) l'évier (m) la baignoire la cuisinière le four le lave-vaisselletah-bluh (bahss) lay-veeay bahn-wahr kwee-zeen-yehr foor lahv-veh-sell mah-sheen ah lah-vay sesh-lahnzh doosh loh-ray-ay mee-rwahr plah-fohn plawn-shay foo-tuhee pawn-dewl koo-vruh-lee vahz lah-vah-boh seh-shwahr kah-nah-pay/soh-fah fair ah ruh-pahs-say ah-speer-ah-turle four à micro-ondes foor ah mee-kroh-ohnd le sèche-linge la douche l'oreiller le miroir le plafond le plancher le fouteuil la pendule le couvrelit le vase le lavabo le séchoir la canapé/le sofa le fer à repasser l'aspirateurWashing Machine la machine à laverla corbeille/la poubelle kor-bayee/poo-bell47. Comparatives and SuperlativesComparatives aussi (adj or adv) que as (adj or adv) asmoins (adj or adv) que less (adj or adv) than plus (adj or adv) que plus de (noun) que autant de (noun) que moins de (noun) que more (adj or adv) than more (noun) than as many (noun) as less (noun) thanThere are some irregularities among bon and bien. Bon is an adjective meaning good, but plus bon is not used (just as more good or gooder is not used in English) so meilleur is used to mean better. Bien is an adverb meaning well, but plus bien is not used either. Mieux is used instead. Sample Sentences She is taller than Colette. I am smarter than you. Elle est plus grande que Colette. Je suis plus intelligente que toi.Peter runs less quickly than me. I have more books than she. We have as many cars as he.Pierre court moins rapide que moi. J'ai plus de livres qu'elle. Nous avons autant de voitures que lui.The kitchen is as big as the living room. La cuisine est aussi grande que le salon.Verbs can also be compared with plus/aussi/moins (+ que): Il travaille moins qu'elle. He works less than she. Ils dorment plus. They sleep more. Superlatives Simply add le, la or les before the comparative if you are using an adjective. With adverbs, always use le. After a superlative, de is used to mean in. If the adjective follows the noun, the superlative follows the noun also, surrounding the adjective. Sample Sentences It's the biggest city in the world. She is the most beautiful woman in this room. It's the most dreaded punishment in the world. She works the most courageously of everyone. C'est la plus grande ville du monde. Elle est la plus belle femme de cette salle. C'est la punition la plus redoutable du monde. Elle travaille le plus courageusement de tous.This neighborhood is the least expensive in Paris. Ce quartier est le moins cher de Paris.In French, you don't use any articles, as compared to English: Plus ça change, plus c'est la même chose. The more things change, the more they stay the same.48. Irregular FormsAdjective bon mauvais petit Comparative Superlativegood meilleur/e better la/le meilleur/e best bad pire worse la/le pire less la/le moindre worst leastsmall moindreAdverb bien wellComparative mieuxSuperlative best most worst leastbetter le mieux more le plus worse le pis less le moinsbeaucoup much plus mal peu badly pis little moinsNote: Only use the irregular forms of mauvais in the abstract sense. If the idea is concrete, you may use plus/moins mauvais and le/la mauvais.49. Clothingpajamas jewelry necklace jeans pants pullover turtleneck raincoat bra slip coat swimsuit shorts bracelet charm t-shirt hat ring chain earrings pin sock shoe man's shirt skirt dress sandal boots jacket scarf tie belt man's suit slippers jacket underwear gloves le pyjama le bijou le collier le jean le pantalon le pull le col roulé l'imperméable (m) le soutien-gorge le jupon le manteau le maillot de bain le short le bracelet le porte-bonheur le tee-shirt le chapeau la bague la chaînette l'épingle (f) la chausette la chaussure la chemise la jupe la robe la sandale des bottes (f) la veste l'écharpe (f) la cravate la ceinture le costume des pantoufles le blouson les sous-vêtements des gants pee-zhah-mah bee-zhoo kohl-eeay zheen pahn-tah-lohn puhl kol roo-lay lahn-pehr-me-ah-bluh shu-meez-eeay soot-ee-ahn-gorzh zhoo-pohn mawn-toe tenn-ee may-oh-duh-bahn short brahs-lay port-bohn-ur tee-shirt shah-poh bahg shen-ett ay-pahn-gluh show-zett show-zer shu-meez zhoop robe sahn-dal bawt vest ay-sharp krah-vaht sahn-tewr kohs-toom ty-er pahn-toof-luh bloo-sohn soo-vet-mawn gawnwoman's shirt le chemisiertennis shoes des tennis (m)les boucles d'oreilles (f) book-luh dor-aywoman's suit le tailleur50. To WearMettre-to put on, wear (met-truh) mets meh mettons met-tohn mets meh mettez met meh mettent met-tay mettOther verbs that are conjugated like mettre: promettre - to promise and permettre - to permit. Note: Porter is actually the verb to wear, but the French use mettre also. When involving clothing, to say It looks good/nice on you say "Il/elle te va bien." To say They look good/nice on you say "Ils/elles te vont bien."51. Future Tenses: Simple and AnteriorThe futur simple expresses an action that will take place. The futur antérieur expresses an action that will have taken place before another future action. The future tense is used just like it is in English, however, in French, the future is always used after quand or lorsque (when), dès que or aussitôt que (as soon as) and tant que (as long as.) To form the future tense, use the infinitive and add these endings that resemble those of avoir. However, you drop the -e from -re verbs. -ai -ons-as -ez -a -ontAnd of course, there has to be exceptions. Here are the irregular stems for the future tense (these will also be used in the conditional tense): Irregular Stems aller avoir courir devoir iraurcourrdevrpleuvoir pleuvrpouvoir pourrrecevoir recevrsavoir tenir valoir venir voir vouloir saurtiendrvaudrviendrverrvoudr-envoyer enverrêtre faire falloir mourir serferfaudrmourr-Other exceptions: For appeler and jeter, double the consonant. For nettoyer and payer, change the y to i. For acheter, add an accent grave. For préférer, the accents all remain the same.jeter jetterai jetteronspayer paierai paieronsacheter achèterai achèteronspréférer préférai préféronsjetteras jetterez jettera jetterontpaieras paierez paiera paierontachèteras achèterez achètera achèterontpréféras préférez préféra préférontTo form the futur antérieur, use the future of either avoir or être (whichever the main verb takes) and the past participle of the main verb. Quand ils reviendront, ils auront changé. When they come back, they will have changed. Dès qu'ils seront revenus, ils voudront repartir. As soon as they have returned, they will want to leave again.52. Preceding and Plural AdjectivesMasculine Adjective beautiful good dear nice big large young pretty long bad new little old Singular beau (bel) bon cher gentil grand gros jeune joli long mauvais Plural beaux bons chers gentils grands gros jeunes jolis longs mauvais Pronunciation boh (bell) bon share zhawn-tee grawn groh zhun zho-lee lohn mo-vay Singular belle bonne chère gentille grande grosse jeune jolie longue Feminine Plural belles bonnes chères gentilles grandes grosses jeunes jolies longues Pronunciation bell bon share zhawn-tee grawnd grohss zhun zho-lee lohngmauvaise mauvaises mo-vezz meilleure meilleures may-ur petite vieille petites vieilles puh-teet vyaybetter, best meilleur petit vieux (vieil)meilleurs may-ur petits vieux puh-tee vyuh (vyay)nouveau (nouvel) nouveaux noo-voh (noo-vell) nouvelle nouvelles noo-vellNote: The masculine singular and plural are pronounced the same, as are the feminine singular and plural. These are the most common adjectives that go before the noun. An acronym to remember which ones go before the noun is BRAGS: Beauty, Resemblance (même and autre), Age/Order (premier and dernier), Goodness, and Size. All other adjectives, except numbers, go after the noun. The three words in parentheses (bel, nouvel, and vieil) are used before masculine singular words beginning with a vowel or a silent h. A few adjectives can be used before or after the noun, and the meaning changes accordingly. When used before the noun, they take a figurative meaning; and when used after, they take a literal meaning. Remember that des means some, right? Well, there is an exception to that rule too. Before plural adjectives preceding plural nouns, you use de instead of des. Ex: Some old monuments. De vieux monuments.53. Adjectives: Formation of FeminineAll adjectives must agree in number and gender with the noun they modify. Most adjectives are given in the masculine form, so to change to the feminine forms, follow these rules: Masculine Add -e If it already ends in -e, add nothing -x changes to -se brun fatigué jeune brahn fah-tee-gay zhun brune fatiguée jeune Feminine brunn fah-tee-gay zhun zhay-nayruhs fohss rooss dooss naht-ur-ell ahn-kee-ett moo-ett koh-kett ee-tahl-eeenn share ac-teev blawnsh pooh-bleek grek lawng Adjective brown tired young generous false red (hair) sweet, soft natural worried silent stylish Italian dear, expensive active white public Greek long liargénéreux zhay-nay-ruh généreuse Exceptions: faux roux doux foh roo doo naht-ur-ell ahn-kee-ay moo-ay koh-kay ee-tahl-eeahn share ac-teef blawn pooh-bleek grek lawn fausse rousse douce naturelle inquiète muette coquette Italienne chère active blanche publique grecque longue-il, -el, and -eil change to -ille, -elle, and -eille -et changes to -ètenaturel inquietExceptions: muet coquet -en and -on change to -enne and -onne -er changes to -ère -f changes to -ve -c changes to -che Italien cher actif blanc Exceptions: public grec -g changes to -gue -eur changes to -euse if adjective is derived from verb -eur changes to -rice if adjective is not same as verb -eur changes to -eure with adjectives of comparison And a few completely irregular ones: longmenteur mawn-turmenteuse mawn-tuhz kray-ahtreess ahn-fay-reeuhr ay-pehz fah-voh-reet frehshcréateur kray-ah-tur inférieur épais favori frais ahn-fay-reeuhr ay-peh fah-voh-ree frehcréatrice inférieure épaisse favorite fraîchecreator inferior thick favorite fresh, cool54. Forming Plurals: Adjectives and NounsTo form the feminine plural, just add an -s, unless it already ends in an s, then add nothing. To formthe masculine plural, just add an -s, except in these cases: -al becomes -aux (exceptions: banal - banals, and final - finals); -eau adds an -x; and if it ends in an x or s already, add nothing. Justremember to change the le, la, or l' to les.And of course there are more exceptions... some adjectives are invariable and do not have femine or plural forms. Compound adjectives, such as bleu clair (light blue) and vert foncé (dark green), adjectives that are also nouns, such as or (gold) and argent (silver), and the words chic (stylish), bon marché or meilleur marché (inexpensive) never change.55. More Adjectivesshort court/e different différent/eloud criard/e situated situé/eelegantélégant/e big gros/setight, narrowétroit/e curious curieux/euseseveral plusieurs nervous nerveux/eusepointed pointu/e only seul/ebright vif, vive amusing amusant/ecute mignon/nne touchingémouvant/eperfect parfait/e funny drôleready prêt/e heavy lourd/esad triste noisy bruyant/eclever malin/gne dirty salelazy paresseux/euse tired fatigué/egenerous généreux/euse angry fâché/efamous célèbre annoyed irrité/edecorated décoré/e oldâgé/eNote: Remember the first word is the masculine and the second is the feminine. The addition of an e for the feminine form allows the last consonant to be voiced. These adjectives go after the noun.56. Rendre + AdjectiveNormally, the verb rendre means to give something that you owe to someone, such as On rend ses devoirs au professeur. It can also be used in the sense of to represent. But rendre + adjective means to make someone or something + adjective.Tu me rends si heureuse! You make me so happy!Le fait qu'il ne possède pas de voiture le rend triste. The fact that he doesn't have a car makeshim sad.57. C'est vs. Il estC'est + adjective + à + infinitive is used when the idea has already been mentioned; while il est + adjective + de + infinitive is used when the idea has not yet been mentioned.Est-ce qu'on peut apprendre le chinois en un an? Non, c'est impossible à apprendre le chinois en un an! Can you learn Chinese in one year? No, it's impossible to learn Chinese in one year!Il est facile d'apprendre l'italien. It is easy to learn Italian.58. Sports and HobbiesSoccer le football luh foot-bahlHockey le hockey luh hock-eeFootball le football américain luh foot-bahl ah-mehr-ee-kahnBasketball le basket luh bahs-kettBaseball le base-ball luh base-bahlHorse-back riding l'équitation; du cheval leh-kee-tah-see-ohn; dew shuh-vahlTennis le tennis luh ten-eeSkiing le ski luh skeeVolleyball le volley luh voll-eeWrestling la lutte lah lootJogging le jogging luh zhog-ingIce-skating le patin à glace luh pah-tahn ah glahsSwimming la natation lah nah-tah-see-ohnTrack and Field l'athlétisme lat-lay-tees-muhBowling le bowling luh boh-lingSoftball le softball luh soft-bahlGolf le golf luh golfBicycling le vélo luh vay-lowSurfing le surf luh serfDirt/Motor biking le bicross luh bee-crossFrench horn le cor d'harmonie kohr dar-moh-neeviolin le violon vee-oh-lohnguitar la guitare gee-tahrdrum le tambour tawn-boortuba le tuba tew-bahflute la flûte flewttrombone le trombone trohn-bohnclarinette la clarinette klah-ree-nettcello le violoncelle vee-oh-lohn-sellharp la harpe arpFaire de + a sport means to play. Jouer à + a sport also means to play, as does jouer de + an instrument.Tu fais du foot. You play soccer.J'aime jouer au tennis. I like to play tennis.Je peux jouer de la guitare. I can play the guitar.Nous jouons de la clarinette. We play the clarinette.Il veut jouer du tuba. He wants to play the tuba.59. Naturesea la mer mehrstone la pierre pee-ehrmade of stone en pierre awn pee-ehrsky le ciel see-yelriver le fleuve fluhvcloud le nuage noo-awzhthunderstorm l'orage oh-rawzhhurricane l'ouragan or-aw-zhawnumbrella la parapluie par-ah-ploo-eemarina le port de plaisance por duh plez-ahnstower la tour toorwood le bois bwahwooden en bois awn bwahspace l'espace es-spahsstar l'étoile ay-twahlbarn la grange grawnzhbridge le pont pohnfarm la ferme fairmfield le champ shawnflower la fleur flurforest la forêt for-ehhill la colline koh-leenlake le lac lahkmountain la montagne mohn-tahn-yuhocean l'océan oh-say-awnplant la plante plahntpond l'étang ay-tawnvalley la vallée vah-laywaterfall le cascade kahs-kahdcountryside la campagne kawn-pawn-yuhcountry le pays pay-eeroad le chemin shu-mahnstreet la rue rewhighway la grande route grahnd rootpath le sentier sahn-teeay60. To Livevivre-to live, be alive (veevr)vis vee vivons vee-vohnvis vee vivez vee-vayvit vee vivent veevThe past participle of vivre is vécu. Habiter is another verb that means to live, but it means to live in a place. Vivre is used to mean the state of being alive. A subjunctive form of vivire, vive, is often usedin exclamations. Vive la France! Long live France!61. Object PronounsSubject Direct Object Indirect Object Disjunctivesje I me (muh)me me to me moi (mwah)metu you te(tuh)you te to you toi (twah)youil he le him lui (lwee)to him lui himelle she la her lui to her elle hernous we nous us nous to us nous usvous you vous you vous to you vous youils they les them leur to them eux (uh)themelles they les them leur to them elles themNote: You have already learned the subject pronouns. They go before the conjugated verb forms. The Direct and Indirect Object pronouns go before the verb even though in English they go after it. They also go after the ne in a negative sentence and right before the verb. The disjunctive always go after prepositions, or can be used alone for emphasis.Sample Sentences:I buy some pants. J'achète des pantalons.I buy them. Je les achète.I give the box to you.Je vous donne la boîte.I give it to you. Je vous la donne.After you. (familiar) Après toi.We go with her. Nous allons avec elle.He doesn't leave her.Il ne la part pas.He leaves her. Il la part.I love you. Je t'aime. or Je vous aime.She doesn't love him.Elle ne l'aime pas.Note: When you have more than one pronoun; me, te, nous, or vous come first, then le, la, or les, then lui or leur. Me, te, le, and la contract to m', t', and l' when they precede a vowel, the same way je does. In commands, the pronouns go after the verb, connected with a hyphen. And the pronoun order changes a little too: Le, la, or les come first; then moi, toi, (Me and te become moi and toi incommands) nous, or vous; then lui, or leur.If you have pronouns, they go before the complete verb in regular sentences; but after the ne andbefore the form of avoir in negative sentences.Nous lui avons parlé. We spoke to him/her.Vous en avez écouté trois.You've listened to three of them.Je t'ai demandé du pain. I asked you for some bread.Il ne l'a pas aimé. He didn't like it/her/him.Tu n'y as pas habité. You didn't live there.Je ne vous ai pas parlé. I didn't speak (or haven't spoken) to you.Nous ne l'avons pas fini. We didn't finish (or haven't finished) it.In the passé composé with avoir, direct object pronouns only must agree in gender and number withthe past participle.Je les ai aimés. I liked them.Il l'a regardée. He watched her.Elles nous ont écouté(e)s.They listened to us.Note: Add an e if the pronoun is feminine, and an s if it is plural. The l' could mean him or her, so you might not need to put the extra e on the past participle. The same for nous and vous. They must have an s because they are plural, but it is unclear as to whether they are masculine or feminine. 62. Parts of the Bodyhead la tête tethair les cheveux shuh-vuhface la figure / le visage fee-ger / vee-sawzhforehead le front frohncheek la joue zhooear l'oreille oh-raybeard la barbe barbeye/s l'œil / les yeux uhee / yuhmustache la moustache moo-stashmouth la bouche booshlip la lèvre lev-ruhnose le nez naytongue la langue lawntooth la dent dawnneck le cou kooeyebrows les sourcils soor-seeeyelashes les cils seelchin le menton mawn-tohnthroat la gorge gorzhskin la peau pohblood le sang sawnbone l'os lohsshoulder l'épaule ay-pohlchest la poitrine pwah-treenwaist la taille taheebelly button le nombril nohn-breeback le dos dohheart le cœur kirarm le bras brahelbow le coude koodwrist le poignet pwahn-yayfist le poing pwahnhand la main mahnfingers les doigts dwahstomach / belly l'estomac / le ventre less-to-mah / vawn-truhbody le corps korehip la hanche ahnshleg la jambe zhambknee le genou zhu-noofoot le pied pyaytoes les orteils or-tieankle la cheville shu-veethigh la cuisse kweessshin le tibia tee-bee-ahthumb le pouce poossnails les ongles ohn-gluhTo say something hurts or that you have an ache, you can use avoir mal à (body part):J'ai mal à la tête. I have a headache.J'ai mal à l'estomac. I have a stomach ache.Elle a mal au bras. Her arm hurts.Tu as mal au genou? Your knee hurts?Il a mal aux orteils. His toes hurt.However, if someone is causing you pain, use faire mal (to hurt) plus the indirect pronoun. Tu me fais mal. You're hurting me.Ne lui faites pas mal. Don't hurt him / her.。

服装日语第7课

関連知識
• 天然繊維の感覚的な良さと合成繊維の機能的な良さがお互いに欠点を補いながら共存している。しかし、近年来は天然繊維の人気が高まり、ブームが続いているが、合成繊維も絶えず感覚、機能の面で改質の研究が進められている。 • たとえば、麻（リネン）の特徴は吸水性が良い、また、吸った水分を容易に蒸発すること、丈夫なこと、光沢があること、熱の良導体であることなどで、夏の衣料用の原料として適している。現在、麻棉の混紡生地がよく使用されている。
関連知識
また、ポリウレタン弾性繊維ははるかに細い糸ができる。染色がよい特長がある。他の糸に対して、５－６％の混用によって、大きな伸縮性が得られて、ニット製品の衿、裾、袖口及びアンダーウェアに活用されている。米国では、スパンデックスと呼ばれている。近年、素材の多様化、ニーズの個性化のため、繊維の種類はますます多岐にわたり、その上、高級化に進んでいるようである。
第７課衣料品生産のプロセス衣料品生産のプロセス
上糸：面线ボタンをかける：扣纽子段違い：位置高低アイロンかけ：熨烫ポイント：重点アイロンあたり：烫印ずれる：错位念入り：精心仕上げ：完成
衣料品生産のプロセスーー関連用語のプロセス－第７課衣料品生産のプロセス－ーー関連用語
切り替え：拼接ダーツ付ダーツ付け：开省スリット：スリット：开叉タブ：タブ：小袢フード付装防风フード付け：装防风帽パイピング：パイピング：滚边りステッチ：飾りステッチ：装饰线レース付装花边レース付け：装花边配色：配色，配色：配色，镶色
第７課衣料品生産のプロセス衣料品生産のプロセス
組長：あのう、ボタン位置がちょっとずれてるね、組長：あのう、ボタン位置がちょっとずれてるね、位置がちょっとずれてるねかけると前立ての下側段違いになっ前立ての下側が見て、かけると前立ての下側が段違いになっちゃうでしょう。修正して正確につけてくだして正確ちゃうでしょう。早く修正して正確につけてください。さい。 • ボタン付け係り：そうですね、悪かった、すぐボタン付そうですね、かった、修正しますします。修正します。 • 組長：衿の部分にもっとアイロンかけて、皺を組長：部分にもっとアイロンかけてにもっとアイロンかけて、なくして、念入りに仕上げてよりに仕上げてよ、なくして、念入りに仕上げてよ、あれはポイントだから。トだから。

百度文库积分是什么

文库的积分主要用来兑换下载券下载文档。

文库的下载券主要用来下载文库中的积分文档。

1) 下载文档时，可以在下载按钮右侧看到该文档需要消费多少下载券。

您须拥有足量的积分来兑换下载券，才能下载文档；
2) 在线浏览文档、收藏您喜欢的文档到您的个人文库、给您浏览的文档加书签，都不需要下载券；
ps：获得的下载券都有使用时间，请在有效期内使用。

积分永久有效。

如果您拥有优质文档资源，建议您通过上传文档，分享帮助他人来获得积分收益。

“知道”里的积分体系分为经验值和财富值两部分，您会付出财富值，也会获得经验值和财富值。

随着经验值的增加您也可以晋级并获得更高的头衔。

什么是经验值？经验值反映了用户在知道的贡献，同时也决定着用户在知道的等级。

用户在知道上获得经验值的操作包括登录、回答、回答被采纳、投票。

登陆每日登陆一次加2分，再次登陆不计分；回答次数没有上限；每次回答获得经验值+2，每次回答被采纳经验值+20，投票每天最多获得经验值20。

此外，如果用户在知道上表现突出，比如获得知道之星等，会额外加分。

什么是财富值？用户可以通过在知道上的优质贡献来获取财富值，其中回答被采纳是获得财富值的主要途径，每个回答被采纳财富值+20+悬赏分。

此外，用户获得知道之星等荣誉也代表其在知道上的优质贡献，同样可以获得财富值。

财富值可以用来消费，比如悬赏、匿名提问和知道传情等。

积分VIP免费得完成任务也能得
就是有些文档下载需要积分。

近藤效应

Tunable Kondo eﬀect in a single donor atomnsbergen 1,G.C.Tettamanzi 1,J.Verduijn 1,N.Collaert 2,S.Biesemans 2,M.Blaauboer 1,and S.Rogge 11Kavli Institute of Nanoscience,Delft University of Technology,Lorentzweg 1,2628CJ Delft,The Netherlands and2InterUniversity Microelectronics Center (IMEC),Kapeldreef 75,3001Leuven,Belgium(Dated:September 30,2009)The Kondo eﬀect has been observed in a single gate-tunable atom.The measurement device consists of a single As dopant incorporated in a Silicon nanostructure.The atomic orbitals of the dopant are tunable by the gate electric ﬁeld.When they are tuned such that the ground state of the atomic system becomes a (nearly)degenerate superposition of two of the Silicon valleys,an exotic and hitherto unobserved valley Kondo eﬀect appears.Together with the “regular”spin Kondo,the tunable valley Kondo eﬀect allows for reversible electrical control over the symmetry of the Kondo ground state from an SU(2)-to an SU(4)-conﬁguration.The addition of magnetic impurities to a metal leads to an anomalous increase of their resistance at low tem-perature.Although discovered in the 1930’s,it took until the 1960’s before this observation was satisfactorily ex-plained in the context of exchange interaction between the localized spin of the magnetic impurity and the de-localized conduction electrons in the metal [1].This so-called Kondo eﬀect is now one of the most widely stud-ied phenomena in condensed-matter physics [2]and plays a mayor role in the ﬁeld of nanotechnology.Kondo ef-fects on single atoms have ﬁrst been observed by STM-spectroscopy and were later discovered in a variety of mesoscopic devices ranging from quantum dots and car-bon nanotubes to single molecules [3].Kondo eﬀects,however,do not only arise from local-ized spins:in principle,the role of the electron spin can be replaced by another degree of freedom,for example or-bital momentum [4].The simultaneous presence of both a spin-and an orbital degeneracy gives rise to an exotic SU(4)-Kondo eﬀect,where ”SU(4)”refers to the sym-metry of the corresponding Kondo ground state [5,6].SU(4)Kondo eﬀects have received quite a lot of theoret-ical attention [6,7],but so far little experimental work exists [8].The atomic orbitals of a gated donor in Si consist of linear combinations of the sixfold degenerate valleys of the Si conduction band.The orbital-(or more speciﬁ-cally valley)-degeneracy of the atomic ground state is tunable by the gate electric ﬁeld.The valley splitting ranges from ∼1meV at high ﬁelds (where the electron is pulled towards the gate interface)to being equal to the donors valley-orbit splitting (∼10-20meV)at low ﬁelds [9,10].This tunability essentially originates from a gate-induced quantum conﬁnement transition [10],namely from Coulombic conﬁnement at the donor site to 2D-conﬁnement at the gate interface.In this article we study Kondo eﬀects on a novel exper-imental system,a single donor atom in a Silicon nano-MOSFET.The charge state of this single dopant can be tuned by the gate electrode such that a single electron (spin)is localized on the pared to quantum dots (or artiﬁcial atoms)in Silicon [11,12,13],gated dopants have a large charging energy compared to the level spac-ing due to their typically much smaller size.As a result,the orbital degree of freedom of the atom starts to play an important role in the Kondo interaction.As we will argue in this article,at high gate ﬁeld,where a (near)de-generacy is created,the valley index forms a good quan-tum number and Valley Kondo [14]eﬀects,which have not been observed before,appear.Moreover,the Valley Kondo resonance in a gated donor can be switched on and oﬀby the gate electrode,which provides for an electri-cally controllable quantum phase transition [15]between the regular SU(2)spin-and the SU(4)-Kondo ground states.In our experiment we use wrap-around gate (FinFET)devices,see Fig.1(a),with a single Arsenic donor in the channel dominating the sub-threshold transport charac-teristics [16].Several recent experiments have shown that the ﬁngerprint of a single dopant can be identiﬁed in low-temperature transport through small CMOS devices [16,17,18].We perform transport spectroscopy (at 4K)on a large ensemble of FinFET devices and select the few that show this ﬁngerprint,which essentially consists of a pair of characteristic transport resonances associ-ated with the one-electron (D 0)-and two-electron (D −)-charge states of the single donor [16].From previous research we know that the valley splitting in our Fin-FET devices is typically on the order of a few meV’s.In this Report,we present several such devices that are in addition characterized by strong tunnel coupling to the source/drain contacts which allows for suﬃcient ex-change processes between the metallic contacts and the atom to observe Kondo eﬀects.Fig.1b shows a zero bias diﬀerential conductance (dI SD /dV SD )trace at 4.2K as a function of gate volt-age (V G )of one of the strongly coupled FinFETs (J17).At the V G such that a donor level in the barrier is aligned with the Fermi energy in the source-drain con-tacts (E F ),electrons can tunnel via the level from source to drain (and vice versa)and we observe an increase in the dI SD /dV SD .The conductance peaks indicated bya r X i v :0909.5602v 1 [c o n d -m a t .m e s -h a l l ] 30 S e p 2009FIG.1:Coulomb blocked transport through a single donor in FinFET devices(a)Colored Scanning Electron Micrograph of a typical FinFET device.(b)Diﬀerential conductance (dI SD/dV SD)versus gate voltage at V SD=0.(D0)and(D−) indicate respectively the transport resonances of the one-and two-electron state of a single As donor located in the Fin-FET channel.Inset:Band diagram of the FinFET along the x-axis,with the(D0)charge state on resonance.(c)and(d) Colormap of the diﬀerential conductance(dI SD/dV SD)as a function of V SD and V G of samples J17and H64.The red dots indicate the(D0)resonances and data were taken at1.6 K.All the features inside the Coulomb diamonds are due to second-order chargeﬂuctuations(see text).(D0)and(D−)are the transport resonances via the one-electron and two-electron charge states respectively.At high gate voltages(V G>450mV),the conduction band in the channel is pushed below E F and the FET channel starts to open.The D−resonance has a peculiar double peak shape which we attribute to capacitive coupling of the D−state to surrounding As atoms[19].The current between the D0and the D−charge state is suppressed by Coulomb blockade.The dI SD/dV SD around the(D0)and(D−)resonances of sample J17and sample H64are depicted in Fig.1c and Fig.1d respectively.The red dots indicate the po-sitions of the(D0)resonance and the solid black lines crossing the red dots mark the outline of its conducting region.Sample J17shows aﬁrst excited state at inside the conducting region(+/-2mV),indicated by a solid black line,associated with the valley splitting(∆=2 mV)of the ground state[10].The black dashed lines indicate V SD=0.Inside the Coulomb diamond there is one electron localized on the single As donor and all the observable transport in this regionﬁnds its origin in second-order exchange processes,i.e.transport via a vir-tual state of the As atom.Sample J17exhibits three clear resonances(indicated by the dashed and dashed-dotted black lines)starting from the(D0)conducting region and running through the Coulomb diamond at-2,0and2mV. The-2mV and2mV resonances are due to a second or-der transition where an electron from the source enters one valley state,an the donor-bound electron leaves from another valley state(see Fig.2(b)).The zero bias reso-nance,however,is typically associated with spin Kondo eﬀects,which happen within the same valley state.In sample H64,the pattern of the resonances looks much more complicated.We observe a resonance around0mV and(interrupted)resonances that shift in V SD as a func-tion of V G,indicating a gradual change of the internal level spectrum as a function of V G.We see a large in-crease in conductance where one of the resonances crosses V SD=0(at V G∼445mV,indicated by the red dashed elipsoid).Here the ground state has a full valley degen-eracy,as we will show in theﬁnal paragraph.There is a similar feature in sample J17at V G∼414mV in Fig.1c (see also the red cross in Fig.1b),although that is prob-ably related to a nearby defect.Because of the relative simplicity of its diﬀerential conductance pattern,we will mainly use data obtained from sample J17.In order to investigate the behavior at the degeneracy point of two valley states we use sample H64.In the following paragraphs we investigate the second-order transport in more detail,in particular its temper-ature dependence,ﬁne-structure,magneticﬁeld depen-dence and dependence on∆.We start by analyzing the temperature(T)dependence of sample J17.Fig.2a shows dI SD/dV SD as a function of V SD inside the Coulomb diamond(at V G=395mV) for a range of temperatures.As can be readily observed from Fig.2a,both the zero bias resonance and the two resonances at V SD=+/-∆mV are suppressed with increasing T.The inset of Fig.2a shows the maxima (dI/dV)MAX of the-2mV and0mV resonances as a function of T.We observe a logarithmic dependence on T(a hallmark sign of Kondo correlations)at both resonances,as indicated by the red line.To investigate this point further we analyze another sample(H67)which has sharper resonances and of which more temperature-dependent data were obtained,see Fig.2c.This sample also exhibits the three resonances,now at∼-1,0and +1mV,and the same strong suppression by tempera-ture.A linear background was removed for clarity.We extracted the(dI/dV)MAX of all three resonances forFIG.2:Electrical transport through a single donor atom in the Coulomb blocked region(a)Diﬀerential conductance of sample J17as a function of V SD in the Kondo regime(at V G=395mV).For clarity,the temperature traces have been oﬀset by50nS with respect to each other.Both the resonances with-and without valley-stateﬂip scale similarly with increasing temperature. Inset:Conductance maxima of the resonances at V SD=-2mV and0mV as a function of temperature.(b)Schematic depiction of three(out of several)second-order processes underlying the zero bias and±∆resonances.(c)Diﬀerential conductance of sample H67as a function of V SD in the Kondo regime between0.3K and6K.A linear(and temperature independent) background on the order of1µS was removed and the traces have been oﬀset by90nS with respect to each other for clarity.(d)The conductance maxima of the three resonances of(c)normalized to their0.3K value.The red line is aﬁt of the data by Eq.1.all temperatures and normalized them to their respective(dI/dV)MAX at300mK.The result is plotted in Fig.2d.We again observe that all three peaks have the same(log-arithmic)dependence on temperature.This dependenceis described well by the following phenomenological rela-tionship[20](dI SD/dV SD)max (T)=(dI SD/dV SD)T 2KT2+TKs+g0(1)where TK =T K/√21/s−1,(dI SD/dV SD)is the zero-temperature conductance,s is a constant equal to0.22 [21]and g0is a constant.Here T K is the Kondo tem-perature.The red curve in Fig.2d is aﬁt of Eq.(1)to the data.We readily observe that the dataﬁt well and extract a T K of2.7K.The temperature scaling demon-strates that both the no valley-stateﬂip resonance at zero bias voltage and the valley-stateﬂip-resonance atﬁnite bias are due to Kondo-type processes.Although a few examples ofﬁnite-bias Kondo have been reported[15,22,23],the corresponding resonances (such as our±∆resonances)are typically associated with in-elastic cotunneling.Aﬁnite bias between the leads breaks the coherence due to dissipative transitions in which electrons are transmitted from the high-potential-lead to the low-potential lead[24].These dissipative4transitions limit the lifetime of the Kondo-type processes and,if strong enough,would only allow for in-elastic events.In the supporting online text we estimate the Kondo lifetime in our system and show it is large enough to sustain theﬁnite-bias Kondo eﬀects.The Kondo nature of the+/-∆mV resonances points strongly towards a Valley Kondo eﬀect[14],where co-herent(second-order)exchange between the delocalized electrons in the contacts and the localized electron on the dopant forms a many-body singlet state that screens the valley index.Together with the more familiar spin Kondo eﬀect,where a many-body state screens the spin index, this leads to an SU(4)-Kondo eﬀect,where the spin and charge degree of freedom are fully entangled[8].The ob-served scaling of the+/-∆-and zero bias-resonances in our samples by a single T K is an indication that such a fourfold degenerate SU(4)-Kondo ground state has been formed.To investigate the Kondo nature of the transport fur-ther,we analyze the substructure of the resonances of sample J17,see Fig.2a.The central resonance and the V SD=-2mV each consist of three separate peaks.A sim-ilar substructure can be observed in sample H67,albeit less clear(see Fig.2c).The substructure can be explained in the context of SU(4)-Kondo in combination with a small diﬀerence between the coupling of the ground state (ΓGS)-and theﬁrst excited state(ΓE1)-to the leads.It has been theoretically predicted that even a small asym-metry(ϕ≡ΓE1/ΓGS∼=1)splits the Valley Kondo den-sity of states into an SU(2)-and an SU(4)-part[25].Thiswill cause both the valley-stateﬂip-and the no valley-stateﬂip resonances to split in three,where the middle peak is the SU(2)-part and the side-peaks are the SU(4)-parts.A more detailed description of the substructure can be found in the supporting online text.The split-ting between middle and side-peaks should be roughly on the order of T K[25].The measured splitting between the SU(2)-and SU(4)-parts equals about0.5meV for sample J17and0.25meV for sample H67,which thus corresponds to T K∼=6K and T K∼=3K respectively,for the latter in line with the Kondo temperature obtained from the temperature dependence.We further note that dI SD/dV SD is smaller than what we would expect for the Kondo conductance at T<T K.However,the only other study of the Kondo eﬀect in Silicon where T K could be determined showed a similar magnitude of the Kondo signal[12].The presence of this substructure in both the valley-stateﬂip-,and the no valley-stateﬂip-Kondo resonance thus also points at a Valley Kondo eﬀect.As a third step,we turn our attention to the magnetic ﬁeld(B)dependence of the resonances.Fig.3shows a colormap plot of dI SD/dV SD for samples J17and H64 both as a function of V SD and B at300mK.The traces were again taken within the Coulomb diamond.Atﬁnite magneticﬁeld,the central Kondo resonances of both de-vices split in two with a splitting of2.2-2.4mV at B=FIG.3:Colormap plot of the conductance as a function of V SD and B of sample J17at V G=395mV(a)and H64at V G=464mV(b).The central Kondo resonances split in two lines which are separated by2g∗µB B.The resonances with a valley-stateﬂip do not seem to split in magneticﬁeld,a feature we associate with the diﬀerent decay-time of parallel and anti-parallel spin-conﬁgurations of the doubly-occupied virtual state(see text).10T.From theoretical considerations we expect the cen-tral Valley Kondo resonance to split in two by∆B= 2g∗µB B if there is no mixing of valley index(this typical 2g∗µB B-splitting of the resonances is one of the hall-marks of the Kondo eﬀect[24]),and to split in three (each separated by g∗µB B)if there is a certain degree of valley index mixing[14].Here,g∗is the g-factor(1.998 for As in Si)andµB is the Bohr magneton.In the case of full mixing of valley index,the valley Kondo eﬀect is expected to vanish and only spin Kondo will remain [25].By comparing our measured magneticﬁeld splitting (∆B)with2g∗µB B,weﬁnd a g-factor between2.1and 2.4for all three devices.This is comparable to the result of Klein et al.who found a g-factor for electrons in SiGe quantum dots in the Kondo regime of around2.2-2.3[13]. The magneticﬁeld dependence of the central resonance5indicates that there is no signiﬁcant mixing of valley in-dex.This is an important observation as the occurrence of Valley Kondo in Si depends on the absence of mix-ing(and thus the valley index being a good quantum number in the process).The conservation of valley in-dex can be attributed to the symmetry of our system. The large2D-conﬁnement provided by the electricﬁeld gives strong reason to believe that the ground-andﬁrst excited-states,E GS and E1,consist of(linear combi-nations of)the k=(0,0,±kz)valleys(with z in the electricﬁeld direction)[10,26].As momentum perpen-dicular to the tunneling direction(k x,see Fig.1)is con-served,also valley index is conserved in tunneling[27]. The k=(0,0,±k z)-nature of E GS and E1should be as-sociated with the absence of signiﬁcant exchange interac-tion between the two states which puts them in the non-interacting limit,and thus not in the correlated Heitler-London limit where singlets and triplets are formed.We further observe that the Valley Kondo resonances with a valley-stateﬂip do not split in magneticﬁeld,see Fig.3.This behavior is seen in both samples,as indicated by the black straight solid lines,and is most easily ob-served in sample J17.These valley-stateﬂip resonances are associated with diﬀerent processes based on their evo-lution with magneticﬁeld.The processes which involve both a valleyﬂip and a spinﬂip are expected to shift to energies±∆±g∗µB B,while those without a spin-ﬂip stay at energies±∆[14,25].We only seem to observe the resonances at±∆,i.e.the valley-stateﬂip resonances without spinﬂip.In Ref[8],the processes with both an orbital and a spinﬂip also could not be observed.The authors attribute this to the broadening of the orbital-ﬂip resonances.Here,we attribute the absence of the processes with spinﬂip to the diﬀerence in life-time be-tween the virtual valley state where two spins in seperate valleys are parallel(τ↑↑)and the virtual state where two spins in seperate valleys are anti-parallel(τ↑↓).In con-trast to the latter,in the parallel spin conﬁguration the electron occupying the valley state with energy E1,can-not decay to the other valley state at E GS due to Pauli spin blockade.It wouldﬁrst needs toﬂip its spin[28].We have estimatedτ↑↑andτ↑↓in our system(see supporting online text)andﬁnd thatτ↑↑>>h/k b T K>τ↑↓,where h/k b T K is the characteristic time-scale of the Kondo pro-cesses.Thus,the antiparallel spin conﬁguration will have relaxed before it has a change to build up a Kondo res-onance.Based on these lifetimes,we do not expect to observe the Kondo resonances associated with both an valley-state-and a spin-ﬂip.Finally,we investigate the degeneracy point of valley states in the Coulomb diamond of sample H64.This degeneracy point is indicated in Fig.1d by the red dashed ellipsoid.By means of the gate electrode,we can tune our system onto-or oﬀthis degeneracy point.The gate-tunability in this sample is created by a reconﬁguration of the level spectrum between the D0and D−-charge states,FIG.4:Colormap plot of I SD at V SD=0as a function of V G and B.For increasing B,a conductance peak develops around V G∼450mV at the valley degeneracy point(∆= 0),indicated by the dashed black line.Inset:Magneticﬁeld dependence of the valley degeneracy point.The resonance is ﬁxed at zero bias and its magnitude does not depend on the magneticﬁeld.probably due to Coulomb interactions in the D−-states. Figure4shows a colormap plot of I SD at V SD=0as a function of V G and B(at0.3K).Note that we are thus looking at the current associated with the central Kondo resonance.At B=0,we observe an increasing I SD for higher V G as the atom’s D−-level is pushed toward E F. As B is increased,the central Kondo resonance splits and moves away from V SD=0,see Fig.3.This leads to a general decrease in I SD.However,at around V G= 450mV a peak in I SD develops,indicated by the dashed black line.The applied B-ﬁeld splits oﬀthe resonances with spin-ﬂip,but it is the valley Kondo resonance here that stays at zero bias voltage giving rise to the local current peak.The inset of Fig.4shows the single Kondo resonance in dI SD/dV SD as a function of V SD and B.We observe that the magnitude of the resonance does not decrease signiﬁcantly with magneticﬁeld in contrast to the situation at∆=0(Fig.3b).This insensitivity of the Kondo eﬀect to magneticﬁeld which occurs only at∆= 0indicates the profound role of valley Kondo processes in our structure.It is noteworthy to mention that at this speciﬁc combination of V SD and V G the device can potentially work as a spin-ﬁlter[6].We acknowledge fruitful discussions with Yu.V. Nazarov,R.Joynt and S.Shiau.This project is sup-ported by the Dutch Foundation for Fundamental Re-search on Matter(FOM).6[1]Kondo,J.,Resistance Minimum in Dilute Magnetic Al-loys,Prog.Theor.Phys.3237-49(1964)[2]Hewson,A.C.,The Kondo Problem to Heavy Fermions(Cambridge Univ.Press,Cambridge,1993).[3]Wingreen N.S.,The Kondo eﬀect in novel systems,Mat.Science Eng.B842225(2001)and references therein.[4]Cox,D.L.,Zawadowski,A.,Exotic Kondo eﬀects in met-als:magnetic ions in a crystalline electricﬁeld and tun-neling centers,Adv.Phys.47,599-942(1998)[5]Inoshita,T.,Shimizu, A.,Kuramoto,Y.,Sakaki,H.,Correlated electron transport through a quantum dot: the multiple-level eﬀect.Phys.Rev.B48,14725-14728 (1993)[6]Borda,L.Zar´a nd,G.,Hofstetter,W.,Halperin,B.I.andvon Delft,J.,SU(4)Fermi Liquid State and Spin Filter-ing in a Double Quantum Dot System,Phys.Rev.Lett.90,026602(2003)[7]Zar´a nd,G.,Orbitalﬂuctuations and strong correlationsin quantum dots,Philosophical Magazine,86,2043-2072 (2006)[8]Jarillo-Herrero,P.,Kong,J.,van der Zant H.S.J.,Dekker,C.,Kouwenhoven,L.P.,De Franceschi,S.,Or-bital Kondo eﬀect in carbon nanotubes,Nature434,484 (2005)[9]Martins,A.S.,Capaz,R.B.and Koiller,B.,Electric-ﬁeldcontrol and adiabatic evolution of shallow donor impuri-ties in silicon,Phys.Rev.B69,085320(2004)[10]Lansbergen,G.P.et al.,Gate induced quantum conﬁne-ment transition of a single dopant atom in a Si FinFET, Nature Physics4,656(2008)[11]Rokhinson,L.P.,Guo,L.J.,Chou,S.Y.,Tsui, D.C.,Kondo-like zero-bias anomaly in electronic transport through an ultrasmall Si quantum dot,Phys.Rev.B60, R16319-R16321(1999)[12]Specht,M.,Sanquer,M.,Deleonibus,S.,Gullegan G.,Signature of Kondo eﬀect in silicon quantum dots,Eur.Phys.J.B26,503-508(2002)[13]Klein,L.J.,Savage, D.E.,Eriksson,M.A.,Coulombblockade and Kondo eﬀect in a few-electron silicon/silicon-germanium quantum dot,Appl.Phys.Lett.90,033103(2007)[14]Shiau,S.,Chutia,S.and Joynt,R.,Valley Kondo eﬀectin silicon quantum dots,Phys.Rev.B75,195345(2007) [15]Roch,N.,Florens,S.,Bouchiat,V.,Wernsdirfer,W.,Balestro, F.,Quantum phase transistion in a single molecule quantum dot,Nature453,633(2008)[16]Sellier,H.et al.,Transport Spectroscopy of a SingleDopant in a Gated Silicon Nanowire,Phys.Rev.Lett.97,206805(2006)[17]Calvet,L.E.,Wheeler,R.G.and Reed,M.A.,Observa-tion of the Linear Stark Eﬀect in a Single Acceptor in Si, Phys.Rev.Lett.98,096805(2007)[18]Hofheinz,M.et al.,Individual charge traps in siliconnanowires,Eur.Phys.J.B54,299307(2006)[19]Pierre,M.,Hofheinz,M.,Jehl,X.,Sanquer,M.,Molas,G.,Vinet,M.,Deleonibus S.,Oﬀset charges acting as ex-cited states in quantum dots spectroscopy,Eur.Phys.J.B70,475-481(2009)[20]Goldhaber-Gordon,D.,Gres,J.,Kastner,M.A.,Shtrik-man,H.,Mahalu, D.,Meirav,U.,From the Kondo Regime to the Mixed-Valence Regime in a Single-Electron Transistor,Phys.Rev.Lett.81,5225(1998) [21]Although the value of s=0.22stems from SU(2)spinKondo processes,it is valid for SU(4)-Kondo systems as well[8,25].[22]Paaske,J.,Rosch,A.,W¨o lﬂe,P.,Mason,N.,Marcus,C.M.,Nyg˙ard,Non-equilibrium singlet-triplet Kondo ef-fect in carbon nanotubes,Nature Physics2,460(2006) [23]Osorio, E.A.et al.,Electronic Excitations of a SingleMolecule Contacted in a Three-Terminal Conﬁguration, Nanoletters7,3336-3342(2007)[24]Meir,Y.,Wingreen,N.S.,Lee,P.A.,Low-TemperatureTransport Through a Quantum Dot:The Anderson Model Out of Equilibrium,Phys.Rev.Lett.70,2601 (1993)[25]Lim,J.S.,Choi,M-S,Choi,M.Y.,L´o pez,R.,Aguado,R.,Kondo eﬀects in carbon nanotubes:From SU(4)to SU(2)symmetry,Phys.Rev.B74,205119(2006) [26]Hada,Y.,Eto,M.,Electronic states in silicon quan-tum dots:Multivalley artiﬁcial atoms,Phys.Rev.B68, 155322(2003)[27]Eto,M.,Hada,Y.,Kondo Eﬀect in Silicon QuantumDots with Valley Degeneracy,AIP Conf.Proc.850,1382-1383(2006)[28]A comparable process in the direct transport throughSi/SiGe double dots(Lifetime Enhanced Transport)has been recently proposed[29].[29]Shaji,N.et.al.,Spin blockade and lifetime-enhancedtransport in a few-electron Si/SiGe double quantum dot, Nature Physics4,540(2008)7Supporting InformationFinFET DevicesThe FinFETs used in this study consist of a silicon nanowire connected to large contacts etched in a60nm layer of p-type Silicon On Insulator.The wire is covered with a nitrided oxide(1.4nm equivalent SiO2thickness) and a narrow poly-crystalline silicon wire is deposited perpendicularly on top to form a gate on three faces.Ion implantation over the entire surface forms n-type degen-erate source,drain,and gate electrodes while the channel protected by the gate remains p-type,see Fig.1a of the main article.The conventional operation of this n-p-n ﬁeld eﬀect transistor is to apply a positive gate voltage to create an inversion in the channel and allow a current toﬂow.Unintentionally,there are As donors present be-low the Si/SiO2interface that show up in the transport characteristics[1].Relation between∆and T KThe information obtained on T K in the main article allows us to investigate the relation between the splitting (∆)of the ground(E GS)-andﬁrst excited(E1)-state and T K.It is expected that T K decreases as∆increases, since a high∆freezes out valley-stateﬂuctuations.The relationship between T K of an SU(4)system and∆was calculated by Eto[2]in a poor mans scaling approach ask B T K(∆) B K =k B T K(∆=0)ϕ(2)whereϕ=ΓE1/ΓGS,withΓE1andΓGS the lifetimes of E1and E GS respectively.Due to the small∆com-pared to the barrier height between the atom and the source/drain contact,we expectϕ∼1.Together with ∆=1meV and T K∼2.7K(for sample H67)and∆=2meV and T K∼6K(for sample J17),Eq.2yields k B T K(∆)/k B T K(∆=0)=0.4and k B T K(∆)/k B T K(∆= 0)=0.3respectively.We can thus conclude that the rela-tively high∆,which separates E GS and E1well in energy, will certainly quench valley-stateﬂuctuations to a certain degree but is not expected to reduce T K to a level that Valley eﬀects become obscured.Valley Kondo density of statesHere,we explain in some more detail the relation be-tween the density of states induced by the Kondo eﬀects and the resulting current.The Kondo density of states (DOS)has three main peaks,see Fig.1a.A central peak at E F=0due to processes without valley-stateﬂip and two peaks at E F=±∆due to processes with valley-state ﬂip,as explained in the main text.Even a small asym-metry(ϕclose to1)will split the Valley Kondo DOS into an SU(2)-and an SU(4)-part[3],indicated in Fig1b in black and red respectively.The SU(2)-part is positioned at E F=0or E F=±∆,while the SU(4)-part will be shifted to slightly higher positive energy(on the order of T K).A voltage bias applied between the source and FIG.1:(a)dI SD/dV SD as a function of V SD in the Kondo regime(at395mV G)of sample J17.The substructure in the Kondo resonances is the result of a small diﬀerence between ΓE1andΓGS.This splits the peaks into a(central)SU(2)-part (black arrows)and two SU(4)-peaks(red arrows).(b)Density of states in the channel as a result ofϕ(=ΓE1/ΓGS)<1and applied V SD.drain leads results in the Kondo peaks to split,leaving a copy of the original structure in the DOS now at the E F of each lead,which is schematically indicated in Fig.1b by a separate DOS associated with each contact.The current density depends directly on the density of states present within the bias window deﬁned by source/drain (indicated by the gray area in Fig1b)[4].The splitting between SU(2)-and SU(4)-processes will thus lead to a three-peak structure as a function of V SD.Figure.1a has a few more noteworthy features.The zero-bias resonance is not positioned exactly at V SD=0, as can also be observed in the transport data(Fig1c of the main article)where it is a few hundredµeV above the Fermi energy near the D0charge state and a few hundredµeV below the Fermi energy near the D−charge state.This feature is also known to arise in the Kondo strong coupling limit[5,6].We further observe that the resonances at V SD=+/-2mV diﬀer substantially in magnitude.This asymmetry between the two side-peaks can actually be expected from SU(4)Kondo sys-tems where∆is of the same order as(but of course al-ways smaller than)the energy spacing between E GS and。

百度文库下载券怎么购买

百度文库下载券怎么购买1. 引言百度文库是一个在线文档分享平台，用户可以在上面找到各类学术论文、教育资料、企业文档等资源。

然而，有些文档在百度文库上只能在线查看，无法直接下载。

为了解决这个问题，百度文库推出了下载券，用户可以通过购买下载券来下载指定的文档。

本文将介绍百度文库下载券的购买方法。

2. 登录百度账号在购买百度文库下载券之前，您需要先登录您的百度账号。

如果您还没有百度账号，可以前往百度官网注册一个账号。

登录百度账号后，您就可以使用百度文库提供的更多功能，包括购买下载券。

3. 进入下载券页面登录百度账号后，点击网页顶部的“文库”按钮，进入百度文库页面。

在百度文库页面中，您可以搜索您需要购买下载券的文档。

在搜索结果页面中，找到您需要购买下载券的文档，并点击文档名称进入文档详情页面。

4. 选择购买下载券在文档详情页面中，您将看到文档的预览内容。

如果该文档需要购买下载券才能下载，页面上将会出现“购买下载券”按钮。

点击这个按钮，将会弹出下载券的购买页面。

5. 确认购买在下载券的购买页面中，您可以选择购买的下载券的数量。

下载券的价格一般是根据文档的大小和需求程度而定的。

您可以根据自己的需求选择合适的下载券数量。

在确认购买前，务必仔细阅读购买须知和相关说明。

6. 选择支付方式在购买页面中，您需要选择支付方式。

百度文库支持多种支付方式，包括支付宝、微信支付等。

选择好支付方式后，跟随页面提示完成支付操作。

7. 完成购买完成支付后，您将会收到订单确认信息。

同时，您的购买记录将会保存在您的百度账号中。

您可以通过账户设置中的相关选项查看和管理您的购买记录。

此外，您可以通过下载券页面来下载您购买的文档。

8. 使用购买的下载券购买了下载券之后，您可以随时使用这些下载券来下载指定的文档。

您只需要进入文档详情页面，点击“下载”按钮，选择使用下载券进行下载即可。

9. 注意事项在购买百度文库下载券时，有一些注意事项需要您留意：•下载券只能用于指定文档的下载，不能用于其他用途。

知末网下载券说明

知末网（znzmo）下载券说明
1、下载券主要用来下载模型素材
1) 下载模型时，可以在下载按钮左侧看到该模型需要消费多少下载券。

您须拥有足量的下载券才能下载模型；
2) 在线浏览模型、收藏您喜欢的模型到您的个人收藏，不需要下载券；
3) 知末有大量模型收取的模型标价下载券是“0”，只需登录知末，即可下载您需要的模型，不需要下载券。

4) 下载券只可以下载模型，不可以兑换为金额
5) 下载券不可转账到其他帐号
2、如何获得下载券
1.上传模型，通过审核奖励：10下载券/模型上传模型（跳转）
每次上传模型审核通过后即可获得下载券
2.上传模型被下载奖励：定价*下载次数*连连看倍数
上传的模型被其他用户下载后，即可获得定价对应的下载券
3.文章分享奖励：1下载券分享文章
每日分享文章获得下载券上限为1下载券
4.邀请好友奖励：5下载券邀请好友
邀请好友成功注册获得5个下载券，邀请获得下载券无上限
5.关注微信公众号奖励：5下载券关注微信公众号（已关注不显示）首次关注有效
6.订阅邮件奖励：10下载券订阅邮件（已订阅不显示）
首次订阅有效。

日语一二级

动作、体态、姿势等相关词汇及表达：二の腕：にのうで（上手臂）、両手：りょうて、かかと（脚后跟）、ふくらはぎ（腿肚子）、すね（小腿）、ふともも（大腿）、膝：ひざ（膝）、胸：むね（胸）、背中：せなか（背,脊梁）、上半身：じょうはんしん（上半身）、下半身：かはんしん（下半身）、仰向ける：あおむける（向上仰,仰面朝天）、指す：さす（指,指向）、押さえる：おさえる（抓住,捉住）、揃える：そろえる（聚集,聚齐）、跳ね上がる：はねあがる（跳起来）、ジャンプする（跳）、しゃがむ（蹲下）、でんぐり返し（前滚翻）手部：┉に手を当てる（把手放在┉上）、手を上げる（举手）、手を横に広げる（伸张双手）、手を後ろに回す（双手放在身后）、手を振る（抖动双手）腕部：腕を曲げる、腕を伸ばす、腕を組む（叉手）肘部：肘をテーブルにつく（把肘子架在桌子上）、肘を横に張る（把手臂弯曲到前胸）背部：背筋をピント伸ばす（挺直腰板）、背中を丸める（弓腰）、背中を曲げる（曲背）胸部：胸を張る（挺胸）腰部：腰を曲げる（弯腰）、腰を落とす（降低腰身）、腰を伸ばす（挺直腰板）脚部：足を開く、足を閉じる、足を上に上げる（抬脚）、足を組む(翘起腿)膝部：膝を曲げる、膝を伸ばす、膝を床につける（双膝着地）身体：体を起こす（直起身）、体が前かがみになる（身体前倾）图表、图示等相关词汇：时间变化：推移：すいい、変動：へんどう、変化：へんか、移り変わり：うつりかわり（变化，演变）变化倾向：動き：うごき、動向：どうこう、傾向：けいこう、向上：こうじょう（向上，提高）变化程度：平均：へいきん、標準：ひょうじゅん、ピーク、頂点：ちょうてん、水準：すいじゅん、レベル、目立つ：めだつ（显眼，引人注目）变化形式：増減：ぞうげん、増加：ぞうか、上昇：じょうしょう（上升，上涨）、増える、伸びる：のびる（伸长，变长）、上がる：あがる、上回る：うわまわる（超过，越出）、満たす：みたす（充满，填满）、うなぎのぼり（直线上升）、下降：かこう、減少：げんしょう、減る：へる、下回る：したまわる（未达到，以下）、落ち込む：おちこむ（掉进，落入）、横ばい：よこばい（停滞，平稳）、変化がない、伸び悩む：のびなやむ（停滞不前）、増減を繰り返している（徘徊不定）、転じる：てんじる（改变，转换）数量：~高：~だか、~量：~りょう比例：成長率：せいちょうりつ、増加率：ぞうかりつ、~割：~わり、~パーセント基准：一人あたり（人均~）、一人につき（每人~）交通信息及地震信息常考词汇：地震信息：震度：しんど（震级）、マグニチュード（里氏震级）、強震：きょうしん（强烈地震）、弱震：じゃくしん（轻度地震）、横揺れ：よこゆれ（横向摇动）、縦揺れ：たてゆれ（竖向摇动）、震源：しんげん（震中）、津波：つなみ（海啸）交通信息：電車、列車、新幹線、私鉄：してつ（私营铁路）、地下鉄：ちかてつ（地铁）道路、施設：しせつ（设施，设备）、高速道路、一般道路、有料道路、首都高速道路、～自動車道、国道～号線、料金所、出口、入口、インターチェンジ（高速公路出入口）閉鎖：へいさ（封闭）、合流：ごうりゅう（汇合）、一車線規制（单车道限行）、上り線：のぼりせん（上﹝东京、大阪）行线）、下がり線：さがりせん（﹝由东京、大阪回去的）下行线）、両方向（双方向）、～キロの渋滞、流れが悪い：ながれがわるい（车流不畅）列车信息常考词汇：普通：ふつう（列车）、急行：きゅうこう（快车）、特急：とっきゅう（特快）、各駅停車：かくえきていしゃ（〈各站停〉慢车）、各停：かくてい（各站停）、準急：じゅんきゅう（准快车）、快速：かいそく（快速列车）、通勤快速：つうきんかいそく（上下班快速）、特別快速（特别快速列车）特急券：とっきゅうけん（加快票）、前売券：まえうりけん（预售票）、定期券：ていきけん（月票）、回数券：かいすうけん（套票，联票）、自動券売機：じどうけんばいき（自动售票机）、精算書：せいさんじょ（补票处）寝台車：しんだいしゃ（卧铺车）、自由席：じゆうせき（不对号座位）、指定席：していせき（对号座位）、グリーン車（软座）、食堂車：しょくどうしゃ（餐车）、禁煙車：きんえんしゃ（禁烟车厢）、冷房車：れいぼうしゃ（空调车厢）、シルバーシート（〈高龄、残疾等〉特别专座）、ビュッフェ（车站小吃部）～回り（经由～）、～経由（经由～）、～線直通：～せんちょくつう（～次直达）、回送：かいそう（回空）網棚：あみだな（行李架）、～番線：～ばんせん（～号站台）、接続：せつぞく（换乘）払い戻し：はらいもどし（退钱）、見送り：みおくり（送人）人物外貌等相关词汇：1、丸顔：まるがお、面長：おもなが（瓜子脸）、角張った顔：かくばったかお（棱角鲜明的脸型）、四角い顔：しかくいかお（方形脸）、彫りの深い顔立ち：ほりりのふかいかおだち（脸部五官线条鲜明）ひげの人（留胡须的人）2、前髪：まえがみ、ショート（短发）、ロング（长发）、ストレート（直发型）3、カールする（烫披肩卷发）、パーマ（烫发）4、眼睛：目がつり上がる（吊眼）、目が下がっている（三角眼）、眼鏡をかけている（戴眼镜）5、胡须：ひげを伸ばしている（留胡须）、ひげが濃い（胡须浓密）6、头发：前髪を下ろしている（前发下垂）、前髪を上げている（前发梳起）、髪を真ん中で分けている（头发由中间分开）、前髪はストレートでカールしていません（头发直梳、没有烫卷发）、前髪は横に分けています（前发梳向一边）、パーマをかけている（烫发）、頭が薄くなる（头发稀疏）、髪が少なくなる（头发减少）、額が禿げ上がっている（额头没头发）、後退している（前额头发减少、逐渐向后秃）7、眉毛：眉毛が薄い（眉毛稀少）、眉毛が濃い（浓眉）服饰相关常考词汇：西式服装：洋服：ようふく、スーツ（套装）、背広：せびろ（男士西服）、ジャケット（夹克衫）、ワンピース（连衣裙）、ブラウス（女士衬衫）、ドレス（女士西服）、スカート（裙子）、ズボン（裤子）、スラックス（裤子）、ジーンズ（牛仔裤）、セーター（毛衣）、コート（大衣）各部名称：袖：そで（袖子）、襟：えり（领子）、裾：すそ（下摆）、丈：たけ（身长）、ウエスト（腰围）、バスト（胸围）花纹图案：しま模様?チェック（方格）、ストライプ（条纹）、たてじま（竖条）、花柄：はながら（花纹）、水玉模様：みずたまもよう（黑底白圆团图案）、無地：むじ（无图案）、白地：しろじ（白底）装饰用语：リボン（扎头彩带）、ゕクセサリー（随身装饰品）、指輪：ゆびわ（戒指）、イヤリング（耳环）评价用语：はで（华丽）、地味：じみ（朴素）、モダン（时髦）※各种服装细节上的区别：袖子：ノースリーブ（无袖）、半袖：はんそで（短袖）、長袖：ながそで（长袖）领子：丸い襟：まるいえり（圆领）、襟なし：えりなし（无领）裙子：ミニスカート（超短裙）、ロングスカート（长裙）表示位置关系常用词语：1、列：れつ、行：ぎょう、角：かど（拐角）、隅：すみ（角落）、端：はし（端头）、側：がわ、間：あいだ2、そば、隣：となり、あたり、中央：ちゅうおう（中央）、中心：ちゅうしん（中心）3、手前：てまえ（眼前、跟前）、両側：りょうがわ、向かい側：むかいがわ、斜め前：ななめまえ（恻前方）、斜め向かい：ななめむかい（斜对面）、真上：まうえ（正上方）、真下：ました（正下方）、裏：うら（里面）表：おもて（外面）4、平行：へいこう、交互：こうご（相互、交替）、隠す：かくす、接する：せっする（邻接、挨靠）、くっつく（紧靠、紧贴在一起）くっつける（使靠近、是贴紧）、離れる：はなれる、面する：めんする（面对、面向）交差する：こうさする（交叉）5、一つおいてとなり：隔壁的隔壁形状、状态常考词汇：一般：デザイン（装饰，设计）、マーク（标记）、ロゴ（徽标）、印：しるし（记号）、バツ印：バツじるし（叉号）形状：点：てん、丸：まる（圆）、円：えん（圆）、円形：えんけい（圆形）、半円：はんえん（半圆）、楕円形：だえんけい（椭圆形）、四方形：しほうけい（四方形）、長方形：ちょうほうけい（长方形）、三角：さんかく（三角形）、四角：しかく、バツ（叉）、二重：にじゅう（双重，二重）特点：縦：たて（竖）、横：よこ（横）、平ら：たいら（平坦）、細長い：ほそながい（细长）、短い：みじかい、分厚い：ぶあつい（厚的）、薄い（薄）、左右対称に：さゆうたいしょうに（左右对称）、上下対称に：じょうげたいしょうに（上下对称）、等分に：とうぶんに（均等的）特征：ねじる（拧，扭，扭转）、凹む：へこむ（凹陷）、膨らむ：ふくらむ（膨胀，鼓起）、窪む：くぼむ（塌陷）、重なる：かさなる（重叠）、ぶら下げる：ぶらさげる（垂下，垂）、固まる：かたまる、対称する、交差する：こうさする（交错）、ギザギザする（锯齿状不齐）、ごてごてする（杂乱不齐）、落ち着く：おちつく、尖る：とがる（尖，锐）、安定感がある：あんていかんがある（稳定性好）、変わる、縮む：ちぢむ（收缩，缩小）、分ける评价：豪華：ごうか（豪华）、デラックス（豪华）、素敵：すてき（漂亮）、シンプル（单纯，朴素）、実用的、発展性が感じられない（没有其他的可能性）、バランスがいい（平衡好）、すっきりしている（简明，清楚）、ぴったり重なる（完全重叠）日期、时间的相关词汇和表达：星期：※月曜日「げつようび」；火曜日「かようび」；水曜日「すいようび」；木曜日「もくようび」；金曜日「きんようび」；土曜日「どようび」；日曜日「にちようび」日期，时间：※当日「とうじつ」；翌日「よくじつ」；前日「ぜんじつ」；先日「せんじつ」；後日「ごじつ」；数日前「すうじつまえ」；ここ数日；近日「きんじつ」；隔日「かくじつ」；平日「へいじつ」；祝日「しゅくじつ」；定休日「ていきゅうび」；一日中※終日「しゅうじつ」；まる一日；半日「はんにち」；毎日；週間「しゅうかん」；徹夜「てつや」；夜中「よなか」※締め切り日「しめきりひ」/截止日期；日付「ひづけ」/（书信、文件等的）落款日期；日取り「ひどり」/举行仪式等的预定日期表达：※締め切りの期日は明後日だ/ 截止日期是后天。

无土栽培(英文版)

SOILLESS CULTURE of Greenhouse VegetablesAlmost all of the vegetables we find on grocery-store shelves are produced either directly or indirectly in open-field soil. However, soil itself isn't necessary for plant growth - only some of its constituents.Field soil serves two basic purposes: it acts as a reservoir to retain nutrients and water, and it provides physical support for the plant through its root system. Artificial means can also provide these important requirements for plant growth with equal (and sometimes better) growth and yield results compared to field soil, although at substantially greater expense. Well-drained, pathogen-free field soil of uniform texture is the least-expensive medium for plant growth, but soil doesn't always occur in this perfect package. Some soils are poorly textured or shallow, and provide an unsatisfactory root environment because of limited aeration and slow drainage. Pathogenic organisms are a common problem in field soils. When adverse conditions are found in soil and reclamation is impractical, some form of soilless culture may be justified. This guide describes the materials used in soilless culture and discusses management practices in various soilless systems.DEFINING SOILLESS CULTURE Soilless culture is an artificial means of providing plants with support and a reservoir for nutrients and water. The simplest and oldest method for soilless culture is a vessel of water in which inorganic chemicals are dissolved to supply all of the nutrients that plants require. Often called solution culture or water culture, the method was originally termed hydroponics (i. e., "water working") by W. F. Gericke in the 1930s. Over the years, hydroponics has been used sporadically throughout the world as a commercial means of growing both food and ornamental plants. Today, it is used widely in research facilities as a technique for studying plant nutrition. Various modifications of pure-solution culture have occurred. Gravel or sand is sometimes used in soilless systems to provide plant support, and retain some nutrients and water. The retention of nutrients and water can be further improved through the use of spaghnum peat, vermiculite, or bark chips. These are the most commonly used materials, but others - such as rice hulls, bagasse (sugarcane refuse), sedge peat, and sawdust - are used sometimes as constituents in soilless mixes. Straw bales have been used as growing medium in England and Canada. Rockwool (porous stone fiber) is used in Europe, but there is little experience with it in this country.Since the major constituent of the media in artificial growing systems may be solid or liquid, it is appropriate to use the term soilless culture in reference to this general type of growing system and reserve the term hydroponics for those in which water is the principal constituent. Soilless culture methods may thus be classified as either solid- or liquid-medium systems.TYPES OF SOILLESS CULTURE Liquid-medium systems are further differentiated from solid-medium systems by method of operation. Liquid systems are generally closed circuit with respect to nutrient-solution supply: the solution is recirculated from a supply reservoir either continuously or intermittently for a period of days or weeks. The two most common liquid systems in use today are nutrient-flow technique (NFT) and gravel-bed culture.An NFT growing system consists of a series of narrow channels through which nutrient solution is recirculated from a supply tank. A plumbing system of plastic tubing and a submersible pump in the tank are basic components. The channels are generally constructed of opaque plastic film or plastic pipe (fig. 1); asphalt-coated wood or fiberglass also has been used. The basic characteristics of all NFT systems is the shallow depth of solution that is maintained in the channels. Flow is usually continuous,but some systems are operated intermittently by supplying solution a few minutes every hour. The purpose of intermittent flow is to assure adequate aeration of the root systems. This also reduces the energy required; but under rapid-growth conditions, plants could experience water stress if the flow period is too short or infrequent.Therefore, intermittent-flow management seems better adapted to mild-temperature periods or to plantings during their early stages of development. Capillary matting is sometimes used in the bottom of NFT channels, principally to avoid the side-to-side meandering of the solution stream around young root systems, but it also acts as a reservoir by retaining nutrients and water during periods when flow ceases.NFT channels are frequently designed for a single row of plants with a channel width of 6 to 8 inches (15 to 20 cm). Wider channels of 12 to 15 inches (30 to 38 cm) have been used to accommodate two rows of plants, but meandering of the shallow solution stream becomes a problem with greater width. To minimize this problem, small dams can be created at intervals down the channel by placing thin wooden sticks crossways in the stream, or by the use of capillary matting. The channels will need to be sloped 4 to 6 inches per 100feet (10 to 15 cm per 30 in) to maintain gravity flow of the solution. Flow rate into the channels should be in the range of 1 to 2 quarts a minute (I to 2 liters a minute). Channel length should be limited to a maximum of 100 feet (30 in) in order to minimize increased solution temperature on bright days. The ideal solution temperature for tomatoes is 68o to 77o F (20o to 25o C). Temperatures of 59o or 86o F (15o or 3O o C) have been shown to decrease growth and yield of tomatoes. Black plastic-film channels will cause solution temperature to increase on sunny days. During cloudy weather, it may be necessary to heat the solution to the desirable temperature. Solution temperatures in black plastic channels can be decreased by shading or painting the surfaces white or silver. Cooper (1979) provides greater detail on NFT management.Gravel-bed culture utilizes a waterproof trough filled with pea gravel (or some other inert material of similar size), which is plumbed to a nutrient solution reservoir (fig. 2). Gravel particles retain very little water and nutrients, so the system must recirculate solution from the supply tank to the beds several times a day by means of a time clock and submersible pump. Some gravel systems are designed to be fed from the surface through perforated pipes, and drained at the base of the trough through a slitted drain line; others are both subirrigated and drained through a single pipe at the bottom of the bed. The advantage of the two-pipe system is that any root growth into the drain line will not interfere with the uniform distribution of nutrient solution to the bed. In either case, however, root growth will eventually clog the drain line and rotary cleaning equipment must be used to remove it.Gravel-bed troughs are generally 24 to 36 inches (60 to 90 cm) in width and 8 inches (20 cm) deep. Pea gravel must be thoroughly washed before use to remove particles of soil or other material that might clog the drain line. Care should be used in selecting a gravel supply that is free from pathogenic organisms. Treatment of the gravel by steam sterilization or an appropriate fungicide is a wise practice when condition of the material is uncertain.The nutrient-solution supply tank should be large enough to hold a volume of solution about twice that required to fill the beds; this provides a good marginof safety.The plumbing-system lines and submersible pumps should have the capacity to fill the beds in about 15 minutes, and allow complete drainage in 30 to 45 minutes.When managed properly, NFT and gravel-bed systems are capable of growing good crops, but there are some disadvantages that should be taken into consideration. The nutrient concentration of a recirculated nutrient solution is in a continuous state of change because plants are removing elements at different rates. Therefore, some means of monitoring and replenishing must be used to avoid deficiencies (and perhaps toxicities from excesses of some elements). This increases the cost of equipment and laboratory analysis. Recirculatedsystems are power dependent. If electrical energy is disrupted, there is little reservoir of water and nutrients to protect the plants from stress. Recirculation of the solution is an ideal means of spreading any pathogenic organism (such as water-mold fungi) that may be inadvertently introduced to the system. For these reasons, more management care, experience, and capital will be necessary for success with recirculated liquid-medium systems.Solid-medium soilless culture may employ any one of many types of suitable media in various types of containers. Basic requirements are a material of uniform texture that drains well yet retains some nutrients and water, a container in which the material is confined, and a means of supplying nutrient solution. A well-drained sandy loam could be used as a growing medium, but a supply of very uniform soil in the volume required may be difficult to find, and the weight of soil is much greater than other types of material. Sand has been used in soilless systems in which the entire floor of a greenhouse is filled a foot or more in depth, but it is rarely used in container systems because of its weight. Where sand is used, particle-size distribution is an important consideration in order to maintain a good balance between drainage (aeration) and nutrient and water retention. Particle sizes should be in the range of 0.1 to 1.0 mm with an average of 0.25 to 0.50 mm.Full-floor sand culture has been successful for vegetable culture in greenhouses and is considered a good means of providing plants with a uniform, well-drained rooting medium (fig. 3). Installation requires excavation of the greenhouse floor to the intended fill depth, and grading (about 4 inches per 100 feet [10 cm per 30 m]) for drainage. First, the graded area is covered with 10-mil plastic sheeting to prevent root penetration into the underlying soil. Then a system of drain tubes at the spacing of the plant rows is laid out on the plastic and connected to a common drain at the lower end of the house. Sand is then filled to the intended depth over the plastic sheeting and drain lines. Be careful to select sand according to its particle-size distribution, and its freedom from pathogens and constituents that might be toxic to the crop plants. Because of the permanent preparations for full-floor sand culture, it is recommended that sand intended for use in the system be given a growth test in containers before actually filling the greenhouse to determine if it meets the basic requirements.Sand-culture systems for tomatoes or cucumbers are typically irrigated and fertilized by trickle irrigation. The nutrient solution should be supplied at each irrigation because of the relatively low nutrient retention of sand. Irrigation frequency will vary with the crop, its growth stage, and the temperature, but will range from two to several times a day. Depending upon plant size and temperature, tomato and cucumber plants will require in the range of 1/2 to 4 quarts (1/2 to 4 liters) per plant a day. CONTAINER GROWINGSoilless culture in bags, pots, or troughs with a lightweight medium is the simplest, most economical, and easiest to manage of all soilless systems. The most common types of media used in containerized systems of soilless culture are peat-lite (Boodley and Sheldrake 1977), or a mixture of bark and wood chips. Container types range from long wooden troughs in which one or two rows of plants are grown, to polyethylene bags or rigid plastic pots containing one to three plants. Bag or pot systemsusing bark chips or peat-lite are in common use throughout the United States and offer some major advantages over other types of soilless culture: (1) the medium materials have excellent retention qualities for nutrients and water; (2) containers of medium are readily moved in or out of the greenhouse whenever necessary or desirable; (3) they are lightweight and easily handled; (4) the medium is useful for several successive crops; (5) the containers are significantly less expensive and less time-consuming to install- and (6) in comparison with recirculated-hydroponic systems, the nutrient-solution system is less complicated and less expensive to manage. From a plant-nutrition standpoint, the latter advantage is of significant importance. In a recirculated system, the solution is continuously changing in its concentration and its nutrient balance because of differential plant uptake.In the bag or pot system, the volume of medium per container varies from about 1/2 cubic foot ( 14 liters) in vertical poly bags or pots to 2 cubic feet (56 liters) in lay-flat bags. In the vertical-bag system, 4-mil black poly bags with pre-punched drain holes at the bottom are common. One, or sometimes two, tomato or cucumber plants are grown in each bag (fig. 4). Lay-flat bags accommodate two or three plants (fig. 5). In either case, the bags are aligned in rows with spacing appropriate to the type of crop being grown. It is good practice to place vertical bags or pots on a narrow sheet of plastic film to prevent root contact or penetration into the underlying soil. Lay-flat bags, which have drainage slits (or overflow ports) cut along the sides an inch (2. 54 cm) or so above the base, would also benefit from a protective plastic sheet beneath them. Greater detail on lay-flat bag culture is provided byBauerie (1984).Irrigation SystemsNutrient solution is delivered to the containers by supply lines of black polyethylene tubing to spaghetti tubing, spray sticks, or ring drippers in the containers. Application devices have different wetting patterns and are available in different flow rates. The choice of application system is important in order to provide proper wetting of the medium at each irrigation. Texture and porosity of the growing medium, and the surface area to be wetted are important considerations in making the choice. Spaghetti tubing provides a point-source wetting pattern, which might be appropriate for fine-textured types of media and allows water to be conducted laterally with ease. In lay-flat bags, single spaghetti tubes at individual plant holes will provide good wetting of peat-lite media. In a vertical bag containing porous medium, a spray stick with a 90-degree spray pattern will do a good job of irrigation if it is located to wet the majority of the surface. Ring drippers are also a good choice for vertical bags although somewhat more expensive. When choosing an application system for bag or container culture, remember that the objective of irrigation is to distribute nutrient solution uniformly so that all of the medium is wet. Since a root system cannot function in dry medium, dry medium is wasted medium.Growing MediaThe growing medium used in container culture must have good nutrient- and water-holding characteristics, and provide good aeration to the root system. Light weight is another important consideration so that filled containers can be easily handled. Growing media should be free of pathogenic organisms and substances that are toxic to plants. The principal materials that meet these requirements are peat moss, bark, shavings, sawdust, vermiculite, bagasse, and rice hulls. Table 1 provides a summary comparison of the characteristics of these materials. Some should not be used alone, but have one or more characteristics that make them valuable constituents when used in a mixture. Bagasse is low in porosity and high in water-holding capacity, which would lead to poor aeration and drainage if used alone. Because rice hulls have low water-holding capacity and high pore space, plants would be vulnerable to water stress when rice hulls are used alone. Both vermiculite and sawdust are poor choices as sole constituents because their high water-holding capacities can lead to saturation and poor aeration if over-irrigated. Vermiculite particles also tend to collapse with time, resulting in compaction and volume loss. Sawdust (except for cypress and redwood) and bagasse have high carbon: nitrogen ratios (C:N ratios), and require extra nitrogen fertilizer to avoid the competitive demand for nitrogen between microorganisms and the plants. Bagasse, rice hulls, sawdust, and vermiculite possess useful characteristics when used in mixes with other materials in the range of 20 percent to 50 percent of the total volume. Because of their high C:N ratios, bagasse and most sawdust material should be limited to no more than 20 percent of the total volume of a mix.Care should be used in the kind of wood material selected for soilless culture. Cedar, walnut, and eucalyptus may have components that are toxic to plants. Fresh redwood also affects the growth of some plants, but this effect becomes negligible with aging and leaching. The causes of toxicity from wood materials is not clearly understood, but probably varies with the type of plant being grown, and the type and age of wood being used. Wood materials are generally acidic and any toxicity from their use may be due to the effects of acidity on the availability of some nutrients to the plants. In redwood, the toxic component is transient because it decomposes or is leached away during composting. Materials such as pine sawdust decompose rapidly because of the high C:N ratio and, if supplemental nitrogen is not provided or is present in insufficient amount, the deficiency that develops may give the impression of toxicity. The barks of pine, fir, and redwood (and possibly others) can be safely used without growth-retarding effects, but cedar and walnut should be avoided. Sawdust and shavings of pine, fir, and redwood can make good, safe amendments when composted with nitrogen at 13 pounds per cubic yard (8 kg/m 3) for 2 to 3 months.Mixes should not be made merely to take advantage of availability or low cost, but should consider the basic factors of weight, nutrient retention, water-holding capacity, pore space, and C:N ratio. Mixtures of spaghnum peat and horticultural vermiculite (peat-lite) have all of the required characteristics and make an excellent growing medium. Proprietary peat-lite mixes are available, or growers can prepare their own supply from the basic components (Boodley and Sheldrake1977). Barks from pine, fir, cypress, and redwood have been used successfully as a growing medium for greenhouse cucumbers and tomatoes. Particle sizes of bark range generally from 1 to 10 mm in diameter; and the distribution of particle sizes in most mill-run material provides good aeration, and good water- and nutrient-holding characteristics. Abark medium can be used for several successive crops without a significant reduction in volume due to decomposition. A supply of bark with predominantly large particle sizes should be amended with a material such as sawdust, shavings,or bagasse in order to improve water-holdingcapacity.FERTILIZATIONIn field culture, the clay fraction of soils can be expected to supply adequate amounts of at least some of the nutrients required by plants, especially the minor elements.Fertilizer programs for soilless-culture systems must supply all nutrients required by the plants.Carbon, hydrogen, and oxygen are provided from water and carbon dioxide in the air. The grower will supply nitrogen, phosphorus, potassium, calcium,magnesium, sulfur, iron, boron, copper, zinc,manganese, molybdenum, and chlorine. Most medium materials contain small amounts of these elements; but they should not be considered in planning the fertilizer program because they are a small proportion of the requirement, or they may be in forms not readily available to plants.Liquid-medium systems - such as NFT and gravelbed culture - use complete nutrient solutions prepared from soluble inorganic salts containing various elements. Proprietary mixes of all required elements are available, which are simply dissolved inwater to prepare the nutrient solution. These mixes are available in various concentrations and ratios of elements. Nutrient solutions can also be prepared by the grower using readily available soluble salts.Many complete nutrient-solution formulas have been developed and used successfully. All contain the same elements and are generally prepared from the same compounds, although in somewhat different proportions. No one formula is necessarily the best for all plants, but all are capable of providing adequate nutrition. Special formulas are often recommended for a particular crop plant based upon research under the prevailing climatic and water quality conditions at a specific location. These formulas are soundly based for those conditions, but none should be construed as being the best universally under all conditions. They are good points of departure in developing a feeding program for the crop for which they are recommended, and may be well suited for use without alteration.Successful managers seek as much information as possible from reliable sources to develop a sound understanding of plant nutrition and inorganic chemistry before attempting to alter published formulas for their imagined or perceived needs.Improper alteration of formulas can lead to serious adverse effects due to excesses or deficiencies. It is recommended that growers either utilize prepared nutrient mixes obtained from reliable manufacturers or, if preparing their own, follow recommended formulas carefully. Competent assistance should be sought before making changes. Solid-medium systems - such as bark or peat-lite- can be provided with nutrients by three methods: (1) entirely from a complete nutrient solution; (2) from a combination of premixing some elements in the medium and supplying others by liquid feed; or (3) premixing all elements in the medium. The complete nutrient-solution method is commonly used in sand culture and for various mixed media or bark. Nutrient solution is applied up to several times a day to maintain the medium in a moist (but not saturated)condition. This system requires either a supply tank for the nutrient solution or a ratio feeder or fertilizer proportioner that prepares solution upon demand from stock nutrient concentrates. For small greenhouses, the frequent chore of replenishing the solution supply in a tank may be more attractive than investment in a fertilizer proportioner. When using the supply-tank method for a recirculated growing system, the tank should be large enough to hold a volume of solution about twice that required to fill the system. This provides a safe margin of nutrient supply.Nutrient-solution FormulasFormulas for several nutrient solutions are given in the Appendix, along with methods of preparation.While they differ in concentrations of the elements,all have been used successfully by commercial growing operations, principally for the production of tomatoes. Formula I has been widely used in research greenhouses as a general nutrient solution for a wide range of plants, and is a good formula choice where more specific information is not known for a particular crop. It is possible that adjustments in concentrations of some elements (particularly nitrogen, phosphorus, or potassium) may be beneficial to the yield or quality of a given crop.Until research is clear on this, however, it is best to adhere to the basic formula.The formulas in the Appendix list amounts of individual salts to be dissolved in 100 gallons (378liters) of water.This prepares the nutrient solution in the form to be supplied to plants from a storage tank. When a fertilizer proportioner is used, the amount of each salt must be adjusted to account for the dilution rate of the proportioner. By this method, liquid concentrates of the salts are prepared that will be diluted for the final nutrient solution as they are fed through the proportioner. For example (in formula 1), to calculate the amount of potassium nitrate to provide 50 gallons (190 liters) of concentrate to be used with a 200: 1 proportioner, divide 95 grams by 100 to obtain grams per gallon (or by 378 for grams per liter) in the final nutrient solution as shown, then multiply by 200 to obtain the amount in I gallon (or 1 liter) of concentrate, and finally multiply by 50 (or 190 liters) for the amount required for 50 gallons (190 liters) of concentrate. The amount of potassium nitrate required for 50 gallons (190 liters) of 200: 1concentrate is 20.9 pounds or 9550 grams. When preparing concentrates for proportioners, two separate concentrates are required to avoid precipitates. One contains only calcium nitrate and the iron compound; all other ingredients are in the other concentrate. The concentrates are kept in separate tanks and must be used in conjunction with a twin-head proportioner. When activated, the proportioner draws equal volumes from each tank and mixes them with an appropriate amount of water to provide the dilute nutrient solution.When using a proportioner, it is good practice to monitor its operation on a regular basis to be certain that solution of proper concentration of elements is being provided to the plants. This should be done in two ways. A water meter attached to the outlet side will record the volume of solution mixed for aparticular period of time. The depletion of concentrate volume in each tank over the same period of time and the volume of solution supplied should be in the same ratio as the dilution ratio of the proportioner. Another check on the system is to compare periodically the total salt concentration of a physical dilution of both concentrates with water.As an example, mix 200 ml of water with I ml (using a 1-mi pipette for measurement) of each concentrate. Salt concentration can be determined by an analytical laboratory or by a portable battery-operated instrument that measures electrical conductivity (fig. 7). During preparation of the concentrates, measurements of the individual salts should be made very carefully so that the final solution will contain amounts of individual elements as intended in the formula. Mistakes can be made,however, and for this reason it may be wise to sample the final solution from the proportioner and have a complete analysis made in a laboratory on a periodic basis.When premixing fertilizer materials with bark,or bark and sawdust, compounds that supply phosphorus, magnesium, calcium, sulfur, and all minor elements may be added to the growing medium prior to planting. A small amount of nitrogen may also be mixed with the medium I but most and sometimes all of this element is supplied in the irrigation water. Nitrogen is generally supplied in the nitrate form in the range of 100 to 200 ppm. 1The ammonium form of nitrogen, if included, should not exceed 10 percent of the total nitrogen supplied.Potassium also is supplied routinely with nitrogen in the irrigation water at about 200 ppm. A nitrogen/potassium liquid-feed solution providing 150 ppm nitrogen and 2 10 ppm potassium can be prepared by mixing 0.45 pound (208 gm) potassium nitrate and 0.40 pound (182 gm) calcium nitrate in 100 gallons (378 liters) of water. To premix the other elements in the medium per cubic yard (or cubic meter), phosphorus can be supplied as superphosphate (0-20-0) at 2 pounds (1 kg), calcium and magnesium from dolomitic lime at 10 pounds (4.5 kg), and minor elements from trace element mixes such as FTE 503 or Esmigran at 5 ounces (155 gm). Additional iron may be added in dilutedform at I ounce (28 gm) of 138 Fe.The method of premixing all fertilizer materials in the medium before planting may include the use of slow-release nitrogen materials such as Mag-amp,Osmocote, isobutylidene diurea (IBDU), or sulfur-coated urea (SCU). This method is not commonly used but, when compared to the liquid-feed method,it is reported to produce equal or better yields of tomatoes (Sheldrake, Dallwyn, and Sangster 1971).The premix method offers important advantages by eliminating the need to prepare nutrient solutions,and the purchase and maintenance of a fertilizer proportioner. The potential disadvantage of slow-release fertilizers that supply all of the nitrogen and potassium is that they may not be able to release the elements at the proper rate to satisfy the plants'needs. While slow-release fertilizers are widely used in the ornamental plant industry, their success rate and cost-effectiveness on vegetables in soilless culture have not been adequately established. Until more information becomes available, it is suggested that their use be limited to medium amendments in proven fertilizer programs.1ppm (parts per million) = mg per liter. Calculation example: to obtain 100 ppm N from potassium nitrate (14 percent N), 100 / 0. 14= 715 mg potassium nitrate/liter = 0. 715 gm/liter = 2.79 gm potassium nitrate/gallon (1 gallon = 3.785 liters).。

Facebook-Case

Facebook Casea case provided free to faculty & students for non-commercial use© Copyright 1997-2008, John M. Gallaugher, Ph.D. – for more info see: /chapters.html INTRODUCTIONHere’s how much of a Web 2.0 guy Mark Zuckerberg is: during the weeks he spent working on Facebook as a Harvard sophomore, he didn’t have time to study for a course he was taking, “Art in the Time of Augustus,” so he built a website containing all of the artwork in class and pinged his classmates to contribute to a communal study guide. Within hours, the wisdom of crowds produced a sort of custom Cliff Notes for the course, and after reviewing the web based crib sheet, he aced the test. Turns out he didn’t need to take that exam, anyway. Zuck (that’s what the cool kids call him1) dropped out of Harvard later that year.Zuckerberg is known as both a shy, geeky, introvert who eschews parties, as well as for his brash Silicon Valley bad-boy image. After Facebook’s incorporation, Zuckerberg’s job description was listed as “Founder, Master and Commander [and] Enemy of the State.” 2 An early business card read “I’m CEO . . . Bitch.” 3 And let’s not forget that Facebook came out of drunken experiments in his dorm room, one of which was initially to have compared classmates to farm animals (Zuckerberg, threatened with expulsion, later apologized). For one meeting with Sequoia Capital, the venerable Menlo Park, California, venture capital firm that backed Google and YouTube, Zuckerberg showed up in his pajamas. 4By the age of 23, Mark Zuckerberg had graced the cover of Newsweek, been profiled on 60 Minutes, and was discussed in the tech world with a reverence previously reserved only for Steve Jobs and the Google guys, Sergey Brin and Larry Page. But Mark Zuckerberg’s star rose much faster than any of these predecessors. Just two weeks after Facebook launched, the firm had4,000 users. Ten months later it was up to 1 million. The growth continued, and the business world took notice. In 2006 Viacom (parent of MTV) saw that its core demographic was spending a ton of time on Facebook and offered to buy the firm for three quarters of a billion dollars. Zuckerberg passed. 5 Yahoo offered up a cool $1 billion (twice). Zuck passed again, both times. As growth skyrocketed. Facebook built on its stranglehold of the college market (85% of four year college students are Facebook members), opening up first to high schoolers, then to everyone. Web hipsters started selling shirts emblazoned with “I Facebooked your Mom!” Even Microsoft wanted some of Facebook’s magic. In 2006, the firm locked up the right to broker all banner ad sales that run on the U.S. version of Facebook, guaranteeing Zuckerberg’s firm $100 million a year through 2011. In 2007, Microsoft came back, buying 1.6% of the firm for $240 million, and securing the rights to sell banner ads on all Facebook sites worldwide (60% of Facebook users are outside the U.S.).1 For an insider account of Silicon Valley Web 2.0 startups, see Sarah Lacy’s, Once Your Lucky, Twice You’re Good, Gotham Books, 2008.2 McGinn, 20043 Lashinsky, 20074 Hoffman, 20085 Rosenbush, 2006The investment was a shocker. Do the math, and a 1.6% stake for $240 million values Facebook at $15 billion. That meant that a firm with only 500 employees, $150 million in revenues, and helmed by a 23- year-old college dropout was more valuable than General Motors. Then in May 2008 Facebook hit another major milestone: It passed MySpace to become the world’s largest social network. That month, comScore’s numbers showed Facebook with 123.9 million unique visitors and 50.6 billion page views worldwide; MySpace garnered 114.6 million unique visitors and 45.4 billion page views. While MySpace was twice as big as Facebook in the United States, Zuckerberg had leveraged the world to claim the top spot. Rupert Murdoch, whose NewsCorporation owns MySpace, engaged in a little trash talk, referring to Facebook as “the flavor of the month".6 Murdoch, the titan who stands atop a media empire that also includes the WallStreet Journal and Fox, had been outmaneuvered by “the kid.”Why Study Facebook?So what is Facebook and how valuable is it? Looking at the "flavor of the month" and trying to distinguish the reality from the hype is a critical managerial skill. In Facebook’s case, there are a lot of folks with a vested interest in figuring out where the firm is headed. If you want to work there, are you signing on to a firm where your stock options and 401(k) contributions are going to be worth something or worthless? If you’re an investor and Facebook goes public, should you short the firm or increase your holdings? Would you invest in or avoid firms that rely onFacebook’s business? Should your firm rush to partner with the firm? Would you extend the firm credit? Offer it better terms to secure its growing business, or worse terms because you think it’sa risky bet? Is this firm the next Google (underestimated at first, and now wildly profitable andinfluential), the next GeoCities (Yahoo paid $3 billion for it – no one goes to the site today), or the next Skype (deeply impactful with over three hundred million accounts worldwide, but not much of a profit generator)? The jury is still out on all this, but let’s look at the fundamentalswith an eye to applying what we’ve learned. No one has a crystal ball, but we have some keyconcepts that can guide our analysis.Zuckerberg Rules!Many entrepreneurs accept startup capital from venture capitalists (VCs), investor groups that provide funding in exchange for a stake in the firm, and often, a degree of managerial control (usually in the form of a voting seat or seats on the firmʼs board of directors). Typically, the earlier a firm accepts VC money, the more control these investors can exert (earlier investments are riskier, so VCs can demand more favorable terms). VCs usually have deep entrepreneurial experience, a wealth of contacts, and can often offer important guidance and advice, but strong investor groups can oust a firmʼs founder and other executives if theyʼre dissatisfied with the firmʼs performance.At Facebook, however, Zuckerberg owns an estimated 20% to 30% of the company, and controls three of five seats on the firmʼs board of directors. That means that heʼs virtually guaranteed to remain in control of the firm, regardless of what investors say. Maintaining this kind of control is unusual in a startup, and his influence is a testament to the speed with which Facebook expanded. By the time Zuckerberg reached out to VCs, his firm was so hot that he could call the shots, giving up surprisingly little in exchange for their money.6 Morrissey, 2008What’s the Big Deal?Last decade’s golden boy, Netscape founder Marc Andreessen, has said that Facebook is “an amazing achievement one of the most significant milestones in the technology industry in this decade."7 Why is Facebook considered such a big deal?First there’s the growth: In the hypergrowth period before the firm passed MySpace, Facebook was adding 150,000 users a day. It was as if every 24 hours, fans at three sold-out major league stadiums filed into Facebook’s servers.8 From May 2007 to May 2008, Facebook’s user base grew 162%, compared with 5% for MySpace. In the United States, Facebook grew 34%, versus MySpace’s 7%.9The number of visitors to the site jumped 300% to 100 million in February, up from 24.8 million in February 2007.10 Two-thirds of its users visit the site every single day,11 with the majority of users spending over half an hour getting their daily Facebook fix.12 And it seems that Mom really is on Facebook (Dad, too); users 35 years and older account for more than half of Facebook’s daily visitors.13Then there’s what these users are doing: Facebook isn’t just a collection of personal home pages, and a place to declare your allegiance to your friends. The integrated set of Facebook services encroaches on a wide swath of established Internet businesses. It’s not just that the site offers tools for messaging and chat, it’s the first-choice messaging tool for a generation. E-mail is for your professors, but Facebook is for friends. In photos, Google, Yahoo, and MySpace all spent millions to acquire photo sharing tools (Picasa, Flickr, and Photobucket, respectively). ButFacebook is now the biggest photo sharing site on the Web, taking in some 14 million photos each day. ABC News cosponsored U.S. presidential debates with Facebook, while major news outlets, including the New York Times, now offer Facebook icons accessible from every online story, encouraging users to "share" content from the Times on their profile pages. All of a sudden Facebook gets space on a page along side and , even though those guys showed up first.So What's It Take to Run This Thing?Technology Review recently ran a profile looking at the innards of the Facebook cloud14 (the big group of connected servers that power the site). This hardware sits at three hosting facilities: in San Francisco, Santa Clara, and northern Virginia. The innards that make up the bulk of the system arenʼt that different from what youʼd find on a high end commodity workstation. Standard hard drives and eight core Intel processors - just a whole lot of them lashed together through networking and software. Much of the software that powers the site is open source. A good portion of the code is in PHP (a scripting language particularly well suited for website 7 Vogelstein, 2007. While still in his 20s, Andreesen founded Netscape, eventually selling it to AOL for over $4 billion. Hissecond firm, Opsware, was sold to H-P for $1.6 billion. He joined Facebook’s Board of Directors within months of making this comment.8 Hoffman, 20089 Musgrove, 200810 Hempel, April 200811 Lacey, 200812 CrunchBase, June 2008 and Krivak, 200813 Hagel and Brown, 2008development), while the databases are in MySQL (a popular open source database), and the cache (that holds frequently accessed objects in chip-based RAM instead on slower hard drives) is managed through the open source product called Memcache. Other code components are written in a variety of languages, including C++, Java, Python, and Ruby, with access between these components managed by a proprietary code layer the firm calls Thrift. The site receives some 15 million requests per second, and 95% of data queries can be served from a huge, distributed server cache that lives in 15 terabytes of RAM (objects like video and photos are stored on hard drives).Hot stuff (literally), but itʼs not enough. The firm raised several hundred million dollars more in the months following the fall 2007 Microsoft deal, focused largely on expanding the firmʼs server network to keep up with the crush of growth. Of the $100 million raised in May 2008, CFO Gideon Yu said “It will be used entirely for servers.”15 Facebook will be buying them by the thousands for years to come.The Social GraphAt the heart of Facebook’s appeal is a concept Zuckerberg calls the social graph. This refers to Facebook’s ability to collect, express, and leverage the interconnections between the site’s users, or as some describe it, “the global mapping of everyone and how they’re related.”16 Think of all the stuff that’s on Facebook as a node or endpoint that’s connected to other stuff. You’reconnected to other users (your friends), photos about you are tagged, comments you’ve posted carry your name, you’re a member of groups, you’re connected to applications you’ve installed - Facebook links them all.17While MySpace and Facebook are often mentioned in the same sentence, from their founding these sites were conceived differently. It goes beyond the fact that Facebook, with its neat,ordered user profiles, looks like a planned community compared to the garish, Vegas-like free-for-all of MySpace. MySpace was founded by musicians seeking to reach out to unknown users and make them fans. It’s no wonder the firm, with its proximity to LA and ownership by News Corporation, is viewed as more of a media company. It has cut deals to run network television shows on its site, and has even established a record label. It's also important to note that from the start anyone could create a MySpace identity, and this open nature meant that you couldn’talways trust what you saw. Rife with bogus profiles, even News Corporation's Rupert Murdoch has had to contend with the dozens of bogus Ruperts who have popped up on the service!18Facebook, however, was established in the relatively safe cocoon of American undergraduate life, and was conceived as a place where you could reinforce contacts among those who, for the most part, you already knew. The site was one of the first social networks where users actually identified themselves using their real names. If you wanted to be distinguished as working for a certain firm or as a student of a particular university, you had to verify that you were legitimate via an email address issued by that organization. It was this "realness" that became Facebook’s distinguishing feature – bringing along with it a degree of safety and comfort that enabledFacebook to become a true social utility and build out a solid social graph consisting of verified relationships. Since "friending" (which is a link between nodes in the social graph) required both 14 Zeichick, 200815 Ante, 200816 Iskold, 200717 Zeichick, 200818 Petrecca, 2006users to approve the relationship, the network fostered an incredible amount of trust. Today,many Facebook users post their cell phone numbers, their birthdays, offer personal photos, and otherwise share information they’d never do outside their circle of friends. Because of trust,Facebook’s social graph is stronger than MySpace’s.There is also a strong network effect to Facebook. People are attracted to the service becauseothers they care about are more likely to be there than anywhere else online. Without thenetwork effect Facebook wouldn’t exist. And it’s because of the network effect that anothersmart kid in a dorm can’t rip off Zuckerberg in any market where Facebook is the biggest fish.Even an exact copy of Facebook would be a virtual ghost town with no social graph (seefollowing “It’s Not the Technology” below). But there’s also a congestion effect to "friending,"as well (see the Network Effects chapter for more details). Alex Iskold, the CEO ofpersonalization firm AdaptiveBlue, puts it this way: “there is a mismatch between whatindividuals and companies want from social networks. . . . As [the social network] grows, theincentive to share information like social graph and attention with others diminishes.” We want to be part of Facebook because that’s where all our friends are likely to be. But we’re alsounlikely to let our friend groups get too big, because they become too difficult to manage andmonitor.The switching costs for Facebook are also extremely powerful. A move to another service means recreating your entire social graph. The more time you spend on the service, the more you’veinvested in your graph and the less likely you are to move to a rival.Itʼs Not the TechnologyDoes your firm have Facebook envy? KickApps, an 80-person startup in Manhattan, will give you the technology to power your own social network. All KickApps wants is a cut of the ads placed around your content. In its first two years, the site has provided the infrastructure for 20,000 “mini Facebooks”, registering 300 million page views a month19. NPR, ABC, AutoByTel, Harley Davidson, and Kraft all use the service (social networks for Cheez Whiz?).Thereʼs also Ning, run by former Goldman Sachs analyst Gina Bianchini (Netscape founder Mark Andreessen is her CTO). Ning has over 750,000 mini networks organized on all sorts of topics families, radio personalities, church groups, vegans, diabetes sufferers and is adding 1,500 to 2,000 a day.Or how about the offering from Agriya Infoway, based in Chennai, India? The firm will sell you Kootali, a software package that lets developers replicate Facebookʼs design and features, complete with friend networks, photos, and mini-feeds. They havenʼt stolen any code, but they have copied the companyʼs look and feel. Those with Zuckerberg ambitions can pony up the $400 bucks for Kootali. Sites with names like and have done just that – and gone nowhere.Mini networks that extend the conversation (NPR) or make it easier to find other rapidly loyal product fans (Harley Davidson) may hold a niche for some firms. And Ning is a neat way for specialized groups to quickly form in a secure environment thatʼs all their own (itʼs just us, no "creepy friends" from the other networks). While every market has a place for its niches, none of these will grow to compete with the dominant social networks. The value isnʼt in the technology, itʼs in what the technology has created over time. For Facebook, itʼs a huge user base that (for now at least) is not going anywhere else.19 Urstadt, 2008FACEBOOK FEEDS – EBOLA FOR DATA FLOWSWhile the authenticity and trust offered by Facebook was critical, offering News Feeds concentrated and released value from the social graph. With feeds, each time a user performs an activity in Facebook – makes a friend, uploads a picture, joins a group – the feed blasts this information to all of your friends in a reverse chronological list that shows up right when they next log on. All of an individual user’s activities are also listed within a Mini Feed that shows up on their profile. Get a new job, move to a new city, read a great article, have a pithy quote – post it to Facebook – the feed picks it up, and the world of your Facebook friends will get an update. Feeds are perhaps the linchpin of Facebook’s ability to strengthen and deliver user value from the social graph, but for a brief period of time it looked like feeds would kill the company. News Feeds were launched on September 5, 2006, just as many of the nation’s undergrads were arriving on campus. Feeds reflecting any Facebook activity (including changes to the relationship status) became a sort of gossip page splashed right when your friends logged in. To many, feeds were first seen as a viral blast of digital nosiness – a release of information they hadn’t consented to distribute widely.And in a remarkable irony, user disgust over the News Feed ambush offered a whip crack demonstration of the power and speed of the feed virus. Protest groups formed, and every student who, for example, joined a group named Students Against Facebook News Feed, had this fact blasted to their friends (along with a quick link where friends, too, could click to join the group). Hundreds of thousands of users mobilized against the firm in just 24 hours. It looked like Zuckerberg’s creation had turned on him, Frankenstein style.The first official Facebook blog post on the controversy came off as a bit condescending (never a good tone to use when your customers feel that you’ve wronged them). “Calm down. Breathe. We hear you,” wrote Zuckerberg on the evening of September 5. The next post, three days after the News Feed launch, was much more contrite (“We really messed this one up,” he wrote). In the 484-word open letter, Zuckerberg apologized for the surprise, explaining how users could opt out of feeds. The tactic worked, and the controversy blew over.20 The ability to stop personal information from flowing into the feed stream was just enough to stifle critics, and as it turns out, a lot of people really liked the feeds and found them useful. It soon became clear that if you wanted to use the Web to keep track of your social life and contacts, Facebook was the place to be. Not only did feeds not push users away, by the start of the next semester subscribers had nearly doubled!F8In May 2007, Facebook followed News Feeds with another initiative that set it head and shoulders above its competition. At a conference called f8 (pronounced "fate"), Mark Zuckerberg stood on stage and announced that Facebook was opening up the screen real estate on Facebook to other application developers. Facebook published a set of APIs that specified how programs could be written to run within and interact with Facebook. Now any programmer could write an 20 Vogelstein, 2007application that would run inside a user’s profile. Geeks of the world, Facebook’s user base could be yours! Just write something good.Developers could charge for their wares, offer them for free, and even run ads. And Facebook let developers keep what they made. This was a key distinction; MySpace initially restricted developer revenue on the few products designed to run on their site, at times even blocking some applications. The choice was clear, and developers flocked to Facebook.To promote the new apps, Facebook would run an Applications area on the site where users could browse offerings. Even better, News Feed was a viral injection that spread the word each time an application was installed. Your best friend just put up a slide show app? Maybe you’ll check it out, too. The predictions of $1 billion in social network ad spending were geek catnip, and legions of programmers wanted a little bit for themselves. Apps could be cobbled together on the quick, feeds made them spread like wildfire, and the early movers offered adoption rates never before seen by small groups of software developers. People began speaking of the Facebook Economy. Facebook was considered a platform. Some compared it to the next Windows, Zuckerberg the next Gates (hey, they both dropped out of Harvard, right?).And each application potentially added more value and features to the site without Facebook lifting a finger. The initial event launched with 65 developer partners and 85 applications. There were some missteps along the way. Some applications were accused of accidentally spamming friends with invites to install them. There were also security concerns, and apps that violated the intellectual property of other firms (see “Scrabulous” sidebar), but Facebook worked to quickly remove errant apps, improve the system, and encourage developers. Just one year in, Facebook had marshaled the efforts of some 400,000 developers and entrepreneurs, 24,000 applications had been built for the platform, 140 new apps were being added each day, and 95% of Facebook members had installed at least one Facebook application. As Sarah Lacy, author of Once You're Lucky, Twice You're Good, put it, “with one masterstroke, Zuck had mobilized all of Silicon Valley to innovate for him.”With feeds to spread the word, Facebook was starting to look like the first place to go to launch an online innovation. Skip the Web, bring it to Zuckerberg’s site first. Consider iLike: within the first three months, the firm saw installs of its Facebook app explode to 7 million, more than doubling the number of users the firm was able to attract through the website it introduced the previous year. iLike became so cool that by September, platinum rocker KT Tunstall was debuting tracks through the Facebook service. A programmer named Mark Pincus wrote a Texas hold ’em game at his kitchen table, scoring 130,000 users in less time than it takes to get through a semester of college. 21 Today his social gaming site, Zynga, has 33 apps and nearly 50 million installs. Seth Goldstein, the CEO of SocialMedia, which developed the Food Fight app, claimed that a buffalo wing chain offered the firm $80,000 to sponsor virtual wings that Facebook users could hurl at their friends. 22 Lee Lorenzen, founder of Altura Ventures, an investment firm21 Guynn, 200722 Blakely and Copeland, 2007exclusively targeting firms creating Facebook apps, said “Facebook is God’s gift to developers.Never has the path from a good idea to millions of users been shorter.”23I Majored in FacebookOnce Facebook became a platform, Stanford professor B. J. Fogg thought it would be a great environment for a programming class. In ten weeks his 73 students built a series of applications that collectively received over 16 million installs. By the final week of class, several applications developed by students, including: KissMe, Send Hotness, and Perfect Match, had all received millions of users, and class apps collectively generated more than $500,000 in ad revenue. At least three companies were formed from the course.Some of the folks developing Facebook applications have serious geek cred. Max Levchin, who (along with Peter Theil) founded PayPal, has widely claimed that his widget company, Slide, would be even bigger than his previous firm (for the record, PayPal sold to eBay for $1.5 billion in 2002). Legg Mason and Fidelity have each already invested at levels giving the firm a $500,000 valuation.24 But is there that much money to be made from selling ads and mining data on SuperPoke? Levchin’s firm is working to craft new advertising measures to track and leverage engagement. Just what are users doing with the applets? With whom? And how might advertisers use these insights to build winning campaigns? Levchin thinks Slide can answer these questions and capture a ton of business along the way.The application framework sounds great, and the numbers are astonishing. But legitimatequestions remain. Are Facebook apps really a big deal? Just how important will apps be toadding sustained value within Facebook? And how will firms leverage the Facebook framework to extract their own value? A chart from FlowingData showed the top category, Just for Fun, was larger than the next four categories combined. That suggests that a lot of applications are faddish time wasters. Yes, there is experimentation beyond virtual Zombie Bites. Visa has created asmall business network on Facebook (Facebook had some 80,000 small businesses online at the time of Visa’s launch). Educational software firm Blackboard offered an application that willpost data to Facebook pages as soon as there are updates to someone’s Blackboard account (new courses, whether assignments or grades have been posted, etc.). We’re still a long way fromFacebook as a Windows rival, but f8 helped push Facebook to #1, and it continues to deliverquirky fun (and then some) supplied by thousands of developers off its payroll.ScrabulousRajat and Jayant Agarwalla, two brothers in Kolkata, India, who run a modest software development company, decided to write a Scrabble clone as a Facebook application. The app, named Scrabulous, was social – users could invite friends to play, or they could search for new players looking for an opponent. Their application was a smash, snagging 3 million registered users and 700,000 players a day after just a few months. Scrabulous was featured in PC World's 100 best products of 2008, received coverage in the New York Times, Newsweek, and Wired, and was pulling in about $25,000 a month from online advertising. Way to go, little guys!2523 Guynn, 200724 Hempel and Copeland, 200825 Timmons, 2008There is only one problem: the Agarwalla brothers didnʼt have the legal rights to Scrabble, and it was apparent to anyone that from the name to the tiles to the scoring – this was a direct rip off of the well-known board game. Hasbro owns the copyright to Scrabble in the United States and Canada; Mattel owns it everywhere else. Thousands of fans joined Facebook groups with names like Save Scrabulous and Please God, I Have So Little: Donʼt Take Scrabulous, Too. Users in some protest groups pledged never to buy Hasbro games if Scrabulous is stopped. Even if the firms wanted to succumb to pressure and let the Agarwalla brothers continue, they couldnʼt. Both Electronic Arts and RealNetworks have contracted with the firms to create online versions of the game.ADVERTISING & SOCIAL NETWORKS: A WORK IN PROGRESSIf Facebook is going to continue to give away its services for free, it needs to make moneysomehow. Right now that means advertising. Fortunately for the firm, online advertising is hot.In 2007, spending on online advertising grew 26% (the only medium growing in double digits).And while 20% of media consumption happens online, the Net attracts just 6% of advertising dollars, suggesting there’s plenty of growth still ahead.26 Firms spend more advertising online than they do on radio ads, and the Net will soon beat out spending on cable TV and magazine ads.27 But not all Internet advertising is created equal. And there are signs that social networking sites are struggling to find the right ad model.In early 2008, Google founder Sergey Brin stated “I don’t think we have the killer best way to advertise and monetize social networks yet.” Brin went on to state that social networking adinventory as a whole was proving problematic and that the “monetization work we were doing there didn’t pan out as well as we had hoped.”28 When Google ad partner Fox Interactive Media (the News Corporation division that contains MySpace) announced that revenue would fall $100 million short of projections, News Corporation’s stock tumbled 5%, analysts downgraded the company, and the firm’s chief revenue officer was dismissed.29Why aren’t social networks having the success of Google and other sites? Problems advertising on these sites include content adjacency, and user attention. The content adjacency problemrefers to concern over where a firm’s advertisements will run. Look at all of the creepy titles in social networking news groups. Do advertisers really want their ads running alongsideconversations that are racy, offensive, illegal, or that may even mock their products? This is a major problem with any site offering ads adjacent to free-form social media.Now let’s look at the user attention problem.Attention Challenges: The Hunt versus the HikeIn terms of revenue model, Facebook isn’t even close to being in the same league as the most successful ad-supported services, nor does Facebook have the focus that advertisers are willing to pay for. Users of Google and other search sites are on a hunt – a task-oriented expedition to collect information that will drive a specific action. Search users want to learn something, buy something, research a problem, get a question answered. To the extent that the hunt overlaps26 Urstadt, 200827 Sweeney, 200828 The Economist, 200829 Stelter, 2008。

GPS152_OwnersManual

i
Introduction FCC Compliance Statement
FCC Compliance
The GPS 152 complies with Part 15 of the FCC interference limits for Class B digital devices FOR HOME OR OFFICE USE. These limits are designed to provide more reasonable protection against harmful interference in a residential installation, and are more stringent than “outdoor” requirements. Operation of this device is subject to the following conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. This equipment generates, uses and cagy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one of the following measures: • Reorient or relocate the receiving antenna. • Increase the separation between the equipment and the receiver. • Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. • Consult the dealer or and experienced radio/TV technician for help. The GPS 152 does not contain any user-serviceable parts. Repairs should only be made by an authorized GARMIN service center. Unauthorized repairs or modiﬁcations could result in permanent damage to the equipment, and void your warranty and your authority to operated this device under Part 15 regulations.

井口信号工操作规程

井口信号工操作规程一、井口信号工接班后，首先对信号系统进行检查，确保信号联系正常、清晰、有问题不得发送开车信号。

二、工作中认真负责，做到眼勤、嘴勤、手勤、脚勤，随时了解掌握生产情况，确保信号准确无误。

三、坚守工作岗位，工作时不得离岗脱岗，更不得其他人员代替信号工工作,打钟房内闲人免进。

四、装拉罐工在接班后,对罐笼、罐挡，罐内阻车器，托罐闸，井口阻车器等进行详细检查,确保可靠工作。

五、上下人员，首先由信号工用电话和机房司机联系,各部正常，方可登罐，并挂上罐笼内的保险链，由井口信号工按规定的人数发出信号。

六、人员上下时必须严格遵守乘罐制度,开车信号发出后，严禁进出罐笼。

七、检修井筒或处理事故人员，如站在罐顶工作时，必须和信号工，绞车司机联系好，方可进行工作。

八、不论井口，井底罐笼装上矿车或矸车,首先放下罐挡，由井底井口负责人向信号工发送开车信号.九、井口信号工收到井底发出的开车信号后,确认无误方可向车房发出开车信号。

十、信号不清、不明,井口信号工不得向车房发送信号.十一、变形车不得装罐下放。

十二、由信号工首先把井口、井底的声光信号打响.十三、其它按《煤矿安全操作规程》执行。

、交接班规定(1）罐笼等提升容器在运行中，一律不准进行交接班，须待罐笼到位停稳，并打定点信号后才准交接;信号工应现场交接清楚以下内容：①主、备用信号及专用联络电话等通讯信号的完好状况;②其它有关设备、设施的完好状况;③上班有关运行工作情况;④当班有关注意事项。

3发现以下两种情况，交接班双方均不得私自交接，须立即汇报有关领导妥善解决后方准交接；①接班人有不正常精神状态；②交班人交待不清当班情况。

4交接班双方均履行正规交接手续。

（5）信号工接班后，应首先与提升机司机及其它信号工联系好，仔细检查试验有关信号设备，设施是否正常，待一切安全可靠后，方可正式提升操作。

2、信号发送(1）信号工在上岗期间,应主动与把罐工（把钩工）密切配合，当把钩工向信号工发出发送信号指令后,信号工有责任监视乘人和装罐等情况，在确认一切正常后，方可发送信号；（2)信号工发出信号，应不离信号工房（室）,并密切监视提升容器、钩头及信号显示系统的运行情况，如发现运行与发送信号不符等异常现象，应立即发出停车信号，待查明原因处理后,方可重新发送信号。