Logarithmic corrections in the free energy of monomer-dimer model on plane lattices with fr

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A Mathematical Theory of Communication

Reprinted with corrections from The Bell System Technical Journal,V ol.27,pp.379–423,623–656,July,October,1948.A Mathematical Theory of CommunicationBy C.E.SHANNONI NTRODUCTIONHE recent development of various methods of modulation such as PCM and PPM which exchangebandwidth for signal-to-noise ratio has intensiﬁed the interest in a general theory of communication.A basis for such a theory is contained in the important papers of Nyquist1and Hartley2on this subject.In the present paper we will extend the theory to include a number of new factors,in particular the effect of noise in the channel,and the savings possible due to the statistical structure of the original message and due to the nature of theﬁnal destination of the information.The fundamental problem of communication is that of reproducing at one point either exactly or ap-proximately a message selected at another point.Frequently the messages have meaning;that is they refer to or are correlated according to some system with certain physical or conceptual entities.These semantic aspects of communication are irrelevant to the engineering problem.The signiﬁcant aspect is that the actual message is one selected from a set of possible messages.The system must be designed to operate for each possible selection,not just the one which will actually be chosen since this is unknown at the time of design.If the number of messages in the set isﬁnite then this number or any monotonic function of this number can be regarded as a measure of the information produced when one message is chosen from the set,all choices being equally likely.As was pointed out by Hartley the most natural choice is the logarithmic function.Although this deﬁnition must be generalized considerably when we consider the inﬂuence of the statistics of the message and when we have a continuous range of messages,we will in all cases use an essentially logarithmic measure.The logarithmic measure is more convenient for various reasons:1.It is practically more useful.Parameters of engineering importance such as time,bandwidth,numberof relays,etc.,tend to vary linearly with the logarithm of the number of possibilities.For example,adding one relay to a group doubles the number of possible states of the relays.It adds1to the base2logarithm of this number.Doubling the time roughly squares the number of possible messages,ordoubles the logarithm,etc.2.It is nearer to our intuitive feeling as to the proper measure.This is closely related to(1)since we in-tuitively measures entities by linear comparison with common standards.One feels,for example,thattwo punched cards should have twice the capacity of one for information storage,and two identicalchannels twice the capacity of one for transmitting information.3.It is mathematically more suitable.Many of the limiting operations are simple in terms of the loga-rithm but would require clumsy restatement in terms of the number of possibilities.The choice of a logarithmic base corresponds to the choice of a unit for measuring information.If the base2is used the resulting units may be called binary digits,or more brieﬂy bits,a word suggested by J.W.Tukey.A device with two stable positions,such as a relay or aﬂip-ﬂop circuit,can store one bit of information.N such devices can store N bits,since the total number of possible states is2N and log22N N.If the base10is used the units may be called decimal digits.Sincelog2M log10M log102332log10M1Nyquist,H.,“Certain Factors Affecting Telegraph Speed,”Bell System Technical Journal,April1924,p.324;“Certain Topics in Telegraph Transmission Theory,”A.I.E.E.Trans.,v.47,April1928,p.617.2Hartley,R.V.L.,“Transmission of Information,”Bell System Technical Journal,July1928,p.535.INFORMATIONSOURCE TRANSMITTER RECEIVER DESTINATIONNOISESOURCEFig.1—Schematic diagram of a general communication system.a decimal digit is about31physical counterparts.We may roughly classify communication systems into three main categories:discrete, continuous and mixed.By a discrete system we will mean one in which both the message and the signal are a sequence of discrete symbols.A typical case is telegraphy where the message is a sequence of lettersand the signal a sequence of dots,dashes and spaces.A continuous system is one in which the message and signal are both treated as continuous functions,e.g.,radio or television.A mixed system is one in which both discrete and continuous variables appear,e.g.,PCM transmission of speech.Weﬁrst consider the discrete case.This case has applications not only in communication theory,but also in the theory of computing machines,the design of telephone exchanges and otherﬁelds.In additionthe discrete case forms a foundation for the continuous and mixed cases which will be treated in the second half of the paper.PART I:DISCRETE NOISELESS SYSTEMS1.T HE D ISCRETE N OISELESS C HANNELTeletype and telegraphy are two simple examples of a discrete channel for transmitting information.Gen-erally,a discrete channel will mean a system whereby a sequence of choices from aﬁnite set of elementarysymbols S1S n can be transmitted from one point to another.Each of the symbols S i is assumed to have a certain duration in time t i seconds(not necessarily the same for different S i,for example the dots anddashes in telegraphy).It is not required that all possible sequences of the S i be capable of transmission on the system;certain sequences only may be allowed.These will be possible signals for the channel.Thus in telegraphy suppose the symbols are:(1)A dot,consisting of line closure for a unit of time and then line open for a unit of time;(2)A dash,consisting of three time units of closure and one unit open;(3)A letter space consisting of,say,three units of line open;(4)A word space of six units of line open.We might place the restriction on allowable sequences that no spaces follow each other(for if two letter spaces are adjacent, it is identical with a word space).The question we now consider is how one can measure the capacity of such a channel to transmit information.In the teletype case where all symbols are of the same duration,and any sequence of the32symbols is allowed the answer is easy.Each symbol representsﬁve bits of information.If the system transmits n symbols per second it is natural to say that the channel has a capacity of5n bits per second.This does not mean that the teletype channel will always be transmitting information at this rate—this is the maximum possible rate and whether or not the actual rate reaches this maximum depends on the source of information which feeds the channel,as will appear later.In the more general case with different lengths of symbols and constraints on the allowed sequences,we make the following deﬁnition:Deﬁnition:The capacity C of a discrete channel is given bylog N TC LimT∞and thereforeC log X0In case there are restrictions on allowed sequences we may still often obtain a difference equation of this type andﬁnd C from the characteristic equation.In the telegraphy case mentioned aboveN t N t2N t4N t5N t7N t8N t10as we see by counting sequences of symbols according to the last or next to the last symbol occurring. Hence C is log0where0is the positive root of12457810.Solving this weﬁnd C0539.A very general type of restriction which may be placed on allowed sequences is the following:We imagine a number of possible states a1a2a m.For each state only certain symbols from the set S1S n can be transmitted(different subsets for the different states).When one of these has been transmitted the state changes to a new state depending both on the old state and the particular symbol transmitted.The telegraph case is a simple example of this.There are two states depending on whether or not a space was the last symbol transmitted.If so,then only a dot or a dash can be sent next and the state always changes. If not,any symbol can be transmitted and the state changes if a space is sent,otherwise it remains the same. The conditions can be indicated in a linear graph as shown in Fig.2.The junction points correspond totheFig.2—Graphical representation of the constraints on telegraph symbols.states and the lines indicate the symbols possible in a state and the resulting state.In Appendix1it is shown that if the conditions on allowed sequences can be described in this form C will exist and can be calculated in accordance with the following result:Theorem1:Let b s i j be the duration of the s th symbol which is allowable in state i and leads to state j. Then the channel capacity C is equal to log W where W is the largest real root of the determinant equation:∑s W bsi j i j0where i j1if i j and is zero otherwise.For example,in the telegraph case(Fig.2)the determinant is:1W2W4W3W6W2W410On expansion this leads to the equation given above for this case.2.T HE D ISCRETE S OURCE OF I NFORMATIONWe have seen that under very general conditions the logarithm of the number of possible signals in a discrete channel increases linearly with time.The capacity to transmit information can be speciﬁed by giving this rate of increase,the number of bits per second required to specify the particular signal used.We now consider the information source.How is an information source to be described mathematically, and how much information in bits per second is produced in a given source?The main point at issue is the effect of statistical knowledge about the source in reducing the required capacity of the channel,by the useof proper encoding of the information.In telegraphy,for example,the messages to be transmitted consist of sequences of letters.These sequences,however,are not completely random.In general,they form sentences and have the statistical structure of,say,English.The letter E occurs more frequently than Q,the sequence TH more frequently than XP,etc.The existence of this structure allows one to make a saving in time(or channel capacity)by properly encoding the message sequences into signal sequences.This is already done to a limited extent in telegraphy by using the shortest channel symbol,a dot,for the most common English letter E;while the infrequent letters,Q,X,Z are represented by longer sequences of dots and dashes.This idea is carried still further in certain commercial codes where common words and phrases are represented by four-orﬁve-letter code groups with a considerable saving in average time.The standardized greeting and anniversary telegrams now in use extend this to the point of encoding a sentence or two into a relatively short sequence of numbers.We can think of a discrete source as generating the message,symbol by symbol.It will choose succes-sive symbols according to certain probabilities depending,in general,on preceding choices as well as the particular symbols in question.A physical system,or a mathematical model of a system which produces such a sequence of symbols governed by a set of probabilities,is known as a stochastic process.3We may consider a discrete source,therefore,to be represented by a stochastic process.Conversely,any stochastic process which produces a discrete sequence of symbols chosen from aﬁnite set may be considered a discrete source.This will include such cases as:1.Natural written languages such as English,German,Chinese.2.Continuous information sources that have been rendered discrete by some quantizing process.Forexample,the quantized speech from a PCM transmitter,or a quantized television signal.3.Mathematical cases where we merely deﬁne abstractly a stochastic process which generates a se-quence of symbols.The following are examples of this last type of source.(A)Suppose we haveﬁve letters A,B,C,D,E which are chosen each with probability.2,successivechoices being independent.This would lead to a sequence of which the following is a typicalexample.B DC B C E C C C AD C B D D A AE C E E AA B B D A E E C A C E E B A E E C B C E A D.This was constructed with the use of a table of random numbers.4(B)Using the sameﬁve letters let the probabilities be.4,.1,.2,.2,.1,respectively,with successivechoices independent.A typical message from this source is then:A A A C D CB DC E A AD A D A CE D AE A D C A B E D A D D C E C A A A A A D.(C)A more complicated structure is obtained if successive symbols are not chosen independentlybut their probabilities depend on preceding letters.In the simplest case of this type a choicedepends only on the preceding letter and not on ones before that.The statistical structure canthen be described by a set of transition probabilities p i j,the probability that letter i is followedby letter j.The indices i and j range over all the possible symbols.A second equivalent way ofspecifying the structure is to give the“digram”probabilities p i j,i.e.,the relative frequency ofthe digram i j.The letter frequencies p i,(the probability of letter i),the transition probabilities 3See,for example,S.Chandrasekhar,“Stochastic Problems in Physics and Astronomy,”Reviews of Modern Physics,v.15,No.1, January1943,p.1.4Kendall and Smith,Tables of Random Sampling Numbers,Cambridge,1939.p i j and the digram probabilities p i j are related by the following formulas:p i ∑j p i j∑j p j i ∑j p j p j ip i j p i p i j∑j p ij ∑i p i ∑i jp i j 1As a speciﬁc example suppose there are three letters A,B,C with the probability tables:p i j A B C 045i B 21151p i jA1518270C 274135A typical message from this source is the following:A B B A B A B A B A B A B A B B B A B B B B B A B A B A B A B A B B B A C A C A BB A B B B B A B B A B AC B B B A B A.The next increase in complexity would involve trigram frequencies but no more.The choice ofa letter would depend on the preceding two letters but not on the message before that point.A set of trigram frequencies p i j k or equivalently a set of transition probabilities p i j k would be required.Continuing in this way one obtains successively more complicated stochastic pro-cesses.In the general n -gram case a set of n -gram probabilities p i 1i 2i n or of transition probabilities p i 1i 2i n 1i n is required to specify the statistical structure.(D)Stochastic processes can also be deﬁned which produce a text consisting of a sequence of“words.”Suppose there are ﬁve letters A,B,C,D,E and 16“words”in the language with associated probabilities:.10A.16BEBE .11CABED .04DEB .04ADEB.04BED .05CEED .15DEED .05ADEE.02BEED .08DAB .01EAB .01BADD .05CA .04DAD .05EESuppose successive “words”are chosen independently and are separated by a space.A typical message might be:DAB EE A BEBE DEED DEB ADEE ADEE EE DEB BEBE BEBE BEBE ADEE BED DEED DEED CEED ADEE A DEED DEED BEBE CABED BEBE BED DAB DEED ADEB.If all the words are of ﬁnite length this process is equivalent to one of the preceding type,but the description may be simpler in terms of the word structure and probabilities.We may also generalize here and introduce transition probabilities between words,etc.These artiﬁcial languages are useful in constructing simple problems and examples to illustrate vari-ous possibilities.We can also approximate to a natural language by means of a series of simple artiﬁcial languages.The zero-order approximation is obtained by choosing all letters with the same probability and independently.The ﬁrst-order approximation is obtained by choosing successive letters independently but each letter having the same probability that it has in the natural language.5Thus,in the ﬁrst-order ap-proximation to English,E is chosen with probability .12(its frequency in normal English)and W with probability .02,but there is no inﬂuence between adjacent letters and no tendency to form the preferred5Letter,digram and trigram frequencies are given in Secret and Urgent by Fletcher Pratt,Blue Ribbon Books,1939.Word frequen-cies are tabulated in Relative Frequency of English Speech Sounds,G.Dewey,Harvard University Press,1923.digrams such as TH,ED,etc.In the second-order approximation,digram structure is introduced.After aletter is chosen,the next one is chosen in accordance with the frequencies with which the various lettersfollow theﬁrst one.This requires a table of digram frequencies p i j.In the third-order approximation, trigram structure is introduced.Each letter is chosen with probabilities which depend on the preceding twoletters.3.T HE S ERIES OF A PPROXIMATIONS TO E NGLISHTo give a visual idea of how this series of processes approaches a language,typical sequences in the approx-imations to English have been constructed and are given below.In all cases we have assumed a27-symbol “alphabet,”the26letters and a space.1.Zero-order approximation(symbols independent and equiprobable).XFOML RXKHRJFFJUJ ZLPWCFWKCYJ FFJEYVKCQSGHYD QPAAMKBZAACIBZL-HJQD.2.First-order approximation(symbols independent but with frequencies of English text).OCRO HLI RGWR NMIELWIS EU LL NBNESEBY A TH EEI ALHENHTTPA OOBTTV ANAH BRL.3.Second-order approximation(digram structure as in English).ON IE ANTSOUTINYS ARE T INCTORE ST BE S DEAMY ACHIN D ILONASIVE TU-COOWE AT TEASONARE FUSO TIZIN ANDY TOBE SEACE CTISBE.4.Third-order approximation(trigram structure as in English).IN NO IST LAT WHEY CRATICT FROURE BIRS GROCID PONDENOME OF DEMONS-TURES OF THE REPTAGIN IS REGOACTIONA OF CRE.5.First-order word approximation.Rather than continue with tetragram,,n-gram structure it is easierand better to jump at this point to word units.Here words are chosen independently but with their appropriate frequencies.REPRESENTING AND SPEEDILY IS AN GOOD APT OR COME CAN DIFFERENT NAT-URAL HERE HE THE A IN CAME THE TO OF TO EXPERT GRAY COME TO FURNISHESTHE LINE MESSAGE HAD BE THESE.6.Second-order word approximation.The word transition probabilities are correct but no further struc-ture is included.THE HEAD AND IN FRONTAL ATTACK ON AN ENGLISH WRITER THAT THE CHAR-ACTER OF THIS POINT IS THEREFORE ANOTHER METHOD FOR THE LETTERS THATTHE TIME OF WHO EVER TOLD THE PROBLEM FOR AN UNEXPECTED.The resemblance to ordinary English text increases quite noticeably at each of the above steps.Note that these samples have reasonably good structure out to about twice the range that is taken into account in their construction.Thus in(3)the statistical process insures reasonable text for two-letter sequences,but four-letter sequences from the sample can usually beﬁtted into good sentences.In(6)sequences of four or more words can easily be placed in sentences without unusual or strained constructions.The particular sequence of ten words“attack on an English writer that the character of this”is not at all unreasonable.It appears then that a sufﬁciently complex stochastic process will give a satisfactory representation of a discrete source.Theﬁrst two samples were constructed by the use of a book of random numbers in conjunction with(for example2)a table of letter frequencies.This method might have been continued for(3),(4)and(5), since digram,trigram and word frequency tables are available,but a simpler equivalent method was used.To construct(3)for example,one opens a book at random and selects a letter at random on the page.This letter is recorded.The book is then opened to another page and one reads until this letter is encountered. The succeeding letter is then recorded.Turning to another page this second letter is searched for and the succeeding letter recorded,etc.A similar process was used for(4),(5)and(6).It would be interesting if further approximations could be constructed,but the labor involved becomes enormous at the next stage.4.G RAPHICAL R EPRESENTATION OF A M ARKOFF P ROCESSStochastic processes of the type described above are known mathematically as discrete Markoff processes and have been extensively studied in the literature.6The general case can be described as follows:There exist aﬁnite number of possible“states”of a system;S1S2S n.In addition there is a set of transition probabilities;p i j the probability that if the system is in state S i it will next go to state S j.To make thisMarkoff process into an information source we need only assume that a letter is produced for each transition from one state to another.The states will correspond to the“residue of inﬂuence”from preceding letters.The situation can be represented graphically as shown in Figs.3,4and5.The“states”are thejunctionFig.3—A graph corresponding to the source in example B.points in the graph and the probabilities and letters produced for a transition are given beside the correspond-ing line.Figure3is for the example B in Section2,while Fig.4corresponds to the example C.In Fig.3Fig.4—A graph corresponding to the source in example C.there is only one state since successive letters are independent.In Fig.4there are as many states as letters. If a trigram example were constructed there would be at most n2states corresponding to the possible pairs of letters preceding the one being chosen.Figure5is a graph for the case of word structure in example D. Here S corresponds to the“space”symbol.5.E RGODIC AND M IXED S OURCESAs we have indicated above a discrete source for our purposes can be considered to be represented by a Markoff process.Among the possible discrete Markoff processes there is a group with special properties of signiﬁcance in communication theory.This special class consists of the“ergodic”processes and we shall call the corresponding sources ergodic sources.Although a rigorous deﬁnition of an ergodic process is somewhat involved,the general idea is simple.In an ergodic process every sequence produced by the process 6For a detailed treatment see M.Fr´e chet,M´e thode des fonctions arbitraires.Th´e orie des´e v´e nements en chaˆıne dans le cas d’un nombreﬁni d’´e tats possibles.Paris,Gauthier-Villars,1938.is the same in statistical properties.Thus the letter frequencies,digram frequencies,etc.,obtained from particular sequences,will,as the lengths of the sequences increase,approach deﬁnite limits independent of the particular sequence.Actually this is not true of every sequence but the set for which it is false has probability zero.Roughly the ergodic property means statistical homogeneity.All the examples of artiﬁcial languages given above are ergodic.This property is related to the structure of the corresponding graph.If the graph has the following two properties7the corresponding process will be ergodic:1.The graph does not consist of two isolated parts A and B such that it is impossible to go from junctionpoints in part A to junction points in part B along lines of the graph in the direction of arrows and also impossible to go from junctions in part B to junctions in part A.2.A closed series of lines in the graph with all arrows on the lines pointing in the same orientation willbe called a“circuit.”The“length”of a circuit is the number of lines in it.Thus in Fig.5series BEBES is a circuit of length5.The second property required is that the greatest common divisor of the lengths of all circuits in the graph beone.If theﬁrst condition is satisﬁed but the second one violated by having the greatest common divisor equal to d1,the sequences have a certain type of periodic structure.The various sequences fall into d different classes which are statistically the same apart from a shift of the origin(i.e.,which letter in the sequence is called letter1).By a shift of from0up to d1any sequence can be made statistically equivalent to any other.A simple example with d2is the following:There are three possible letters a b c.Letter a isfollowed with either b or c with probabilities13respectively.Either b or c is always followed by lettera.Thus a typical sequence isa b a c a c a c a b a c a b a b a c a cThis type of situation is not of much importance for our work.If theﬁrst condition is violated the graph may be separated into a set of subgraphs each of which satisﬁes theﬁrst condition.We will assume that the second condition is also satisﬁed for each subgraph.We have in this case what may be called a“mixed”source made up of a number of pure components.The components correspond to the various subgraphs.If L1,L2,L3are the component sources we may writeL p1L1p2L2p3L37These are restatements in terms of the graph of conditions given in Fr´e chet.where p i is the probability of the component source L i.Physically the situation represented is this:There are several different sources L1,L2,L3which are each of homogeneous statistical structure(i.e.,they are ergodic).We do not know a priori which is to be used,but once the sequence starts in a given pure component L i,it continues indeﬁnitely according to the statistical structure of that component.As an example one may take two of the processes deﬁned above and assume p12and p28.A sequence from the mixed sourceL2L18L2would be obtained by choosingﬁrst L1or L2with probabilities.2and.8and after this choice generating a sequence from whichever was chosen.Except when the contrary is stated we shall assume a source to be ergodic.This assumption enables one to identify averages along a sequence with averages over the ensemble of possible sequences(the probability of a discrepancy being zero).For example the relative frequency of the letter A in a particular inﬁnite sequence will be,with probability one,equal to its relative frequency in the ensemble of sequences.If P i is the probability of state i and p i j the transition probability to state j,then for the process to be stationary it is clear that the P i must satisfy equilibrium conditions:P j∑iP i p i jIn the ergodic case it can be shown that with any starting conditions the probabilities P j N of being in state j after N symbols,approach the equilibrium values as N∞.6.C HOICE,U NCERTAINTY AND E NTROPYWe have represented a discrete information source as a Markoff process.Can we deﬁne a quantity which will measure,in some sense,how much information is“produced”by such a process,or better,at what rate information is produced?Suppose we have a set of possible events whose probabilities of occurrence are p1p2p n.These probabilities are known but that is all we know concerning which event will occur.Can weﬁnd a measure of how much“choice”is involved in the selection of the event or of how uncertain we are of the outcome?If there is such a measure,say H p1p2p n,it is reasonable to require of it the following properties:1.H should be continuous in the p i.2.If all the p i are equal,p i12,p216.On the right weﬁrst choose between two possibilities each withprobability13,1216H121312is because this second choice only occurs half the time.In Appendix2,the following result is established:Theorem2:The only H satisfying the three above assumptions is of the form:H Kn∑i1p i log p iwhere K is a positive constant.This theorem,and the assumptions required for its proof,are in no way necessary for the present theory.It is given chieﬂy to lend a certain plausibility to some of our later deﬁnitions.The real justiﬁcation of these deﬁnitions,however,will reside in their implications.Quantities of the form H∑p i log p i(the constant K merely amounts to a choice of a unit of measure) play a central role in information theory as measures of information,choice and uncertainty.The form of H will be recognized as that of entropy as deﬁned in certain formulations of statistical mechanics8where p i isthe probability of a system being in cell i of its phase space.H is then,for example,the H in Boltzmann’s famous H theorem.We shall call H∑p i log p i the entropy of the set of probabilities p1p n.If x is a chance variable we will write H x for its entropy;thus x is not an argument of a function but a label for anumber,to differentiate it from H y say,the entropy of the chance variable y.The entropy in the case of two possibilities with probabilities p and q1p,namelyH p log p q log qis plotted in Fig.7as a function of p.HBITSpFig.7—Entropy in the case of two possibilities with probabilities p and1p.The quantity H has a number of interesting properties which further substantiate it as a reasonable measure of choice or information.1.H0if and only if all the p i but one are zero,this one having the value unity.Thus only when weare certain of the outcome does H vanish.Otherwise H is positive.2.For a given n,H is a maximum and equal to log n when all the p i are equal(i.e.,1。

研究生-2014现代分子生物学英语

time
“The active principle …is responsible for the conversion of normal cells to neoplastic cells”
“It may be (1) a metabolic product of the crown-gall bacterium; (2) a normal host constituent that is converted by the bacteria into a tumorinducing substance; (3) a chemical fraction of the bacterial cell that is capable of initiating, as in the case of the transforming substance (DNA) of the pneumococci, a specific alteration in the host cell; or (4) a virus or other agent which is present in association with the crown-gall organism”
Armin C. Braun 1911 - 1986
Gall tissues can grow indefinitely without exogenous phytohormones
1930s – 1950s, numerous studies Auxin CK
High levels of auxin and cytokinin are found in gall tissues
White, P.R. and Braun, A.C. (1941). Crown gall production by bacteria-free tumor tissues. Science. 94: 239-241; Photo from Wood, H.N., and Kelman, A. (1987) Phytopathology 77: 991.

英语阅读：一个疑病症患者的国度

美联英语提供：英语阅读：A Nation of Hypochondriacs 一个疑病症患者的国度两分钟做个小测试，看看你的英语水平/test/kuaisu.aspx?tid=16-73675-0A Nation of Hypochondriacs 一个疑病症患者的国度The main impression growing out of twelve years on the faculty of a medical school is that the No.1 health problem in the U.S. today, even more than AIDS or cancer, is that Americans don't know how to think about health and illness. Our reactions are formed on the terror level. We fear the worst, expect the worst, thus invite the worst. The result is that we are becoming a nation of weaklings and hypochondriacs, a self-medicating society incapabel of distinguishing between casual, everyday symptoms and those that require professional attention.在一所医学院校任教十二年来,我获得的主要印象是:当今美国头号的健康问题,甚至比爱滋病或癌症都更为严重的问题,就是美国人不知道如何去认识健康与疾病。

我们的反应是建立在恐惧这个尺度之上的。

我们怕最坏的事,期待着最坏的事,而恰恰就招来了最坏的事。

结果,我们变成了一个一个虚弱的、自疑有病的国度,一个分不清哪些是日常偶发症状、哪些又是需要医生医治的症状,而自己擅自用药的社会。

英语翻译—反避税

C. Human DignityFor Raz, the criterion that the law should be capable of guiding action is closely linked to human dignity. [FN76]The law must assume that people are capable of rational thought and that they, therefore, want to plan their lives with the knowledge of what the law is. [FN77] Raz sees this factor as even more *33important than the rule of law's connection with freedom. [FN78]Laws that do not conform to the rule of law are an affront to human dignity, because the law “encourages autonomous action only in order to frustrate its purpose.” [FN79]Raz might well charge general anti-avoidance rules with such an offense. The detailed formality of tax law encourages people to find ways to circumvent it, but general anti-avoidance rules may frustrate their efforts.人类的尊严对于拉兹，其标准是法律与人类的尊严紧密相连，并且能够指引人的行为。

O(alpha) QED Corrections to Polarized Elastic $mu e$ and Deep Inelastic l N Scattering

a r X i v :h e p -p h /9711228v 1 4 N o v 1997hep-ph/9711228October 1997O (α)QED Corrections to Polarized Elastic µe and Deep Inelastic lN ScatteringDima Bardin a,b,c ,Johannes Bl¨u mlein a ,Penka Christova a,d ,and Lida Kalinovskaya a,caDESY–Zeuthen,Platanenallee 6,D–15735Zeuthen,GermanybINFN,Sezione di Torino,Torino,ItalycJINR,ul.Joliot-Curie 6,RU–141980Dubna,RussiadBishop Konstantin Preslavsky University of Shoumen,9700Shoumen,BulgariaAbstractTwo computer codes relevant for the description of deep inelastic scattering oﬀpolarized targets are discussed.The code µe la deals with radiative corrections to elastic µe scattering,one method applied for muon beam polarimetry.The code HECTOR allows to calculate both the radiative corrections for unpolarized and polarized deep inelastic scattering,including higher order QED corrections.1IntroductionThe exact knowledge of QED,QCD,and electroweak (EW)radiative corrections (RC)to the deep inelastic scattering (DIS)processes is necessary for a precise determination of the nucleon structure functions.The present and forthcoming high statistics measurements of polarized structure functions in the SLAC experiments,by HERMES,and later by COMPASS require the knowledge of the RC to the DIS polarized cross-sections at the percent level.Several codes based on diﬀerent approaches for the calculation of the RC to DIS experiments,mainly for non-polarized DIS,were developped and thoroughly compared in the past,cf.[1].Later on the radiative corrections for a vast amount of experimentally relevant sets of kinematic variables were calculated [2],including also semi-inclusive situations as the RC’s in the case of tagged photons [3].Furthermore the radiative corrections to elastic µ-e scattering,a process to monitor (polarized)muon beams,were calculated [4].The corresponding codes are :•HECTOR 1.00,(1994-1995)[5],by the Dubna-Zeuthen Group.It calculates QED,QCD and EW corrections for variety of measuremets for unpolarized DIS.•µe la 1.00,(March 1996)[4],calculates O (α)QED correction for polarized µe elastic scattering.•HECTOR1.11,(1996)extends HECTOR1.00including the radiative corrections for polarized DIS[6],and for DIS with tagged photons[3].The beta-version of the code is available from http://www.ifh.de/.2The Programµe laMuon beams may be monitored using the processes ofµdecay andµe scattering in case of atomic targets.Both processes were used by the SMC experiment.Similar techniques will be used by the COMPASS experiment.For the cross section measurement the radiative corrections to these processes have to be known at high precision.For this purpose a renewed calculation of the radiative corrections toσ(µe→µe)was performed[4].The diﬀerential cross-section of polarized elasticµe scattering in the Born approximation reads,cf.[7],dσBORNm e Eµ (Y−y)2(1−P e Pµ) ,(1)where y=yµ=1−E′µ/Eµ=E′e/Eµ=y e,Y=(1+mµ/2/Eµ)−1=y max,mµ,m e–muon and electron masses,Eµ,E′µ,E′e the energies of the incoming and outgoing muon,and outgoing electron respectively,in the laboratory frame.Pµand P e denote the longitudinal polarizations of muon beam and electron target.At Born level yµand y e agree.However,both quantities are diﬀerent under inclusion of radiative corrections due to bremsstrahlung.The correction factors may be rather diﬀerent depending on which variables(yµor y e)are used.In the SMC analysis the yµ-distribution was used to measure the electron spin-ﬂip asymmetry A expµe.Since previous calculations,[8,9],referred to y e,and only ref.[9]took polarizations into account,a new calculation was performed,including the complete O(α)QED correction for the yµ-distribution,longitudinal polarizations for both leptons,theµ-mass eﬀects,and neglecting m e wherever possible.Furthermore the present calculation allows for cuts on the electron re-coil energy(35GeV),the energy balance(40GeV),and angular cuts for both outgoing leptons (1mrad).The default values are given in parentheses.Up to order O(α3),14Feynman graphs contribute to the cross-section forµ-e scattering, which may be subdivided into12=2×6pieces,which are separately gauge invariantdσQEDdyµ.(2) One may express(2)also asdσQEDdyµ+P e Pµdσpol kk=1−Born cross-section,k=b;2−RC for the muonic current:vertex+bremsstrahlung,k=µµ;3−amm contribution from muonic current,k=amm;4−RC for the electronic current:vertex+bremsstrahlung,k=ee;5−µe interference:two-photon exchange+muon-electron bremsstrahlung interference,k=µe;6−vacuum polarization correction,runningα,k=vp.The FORTRAN code for the scattering cross section(2)µe la was used in a recent analysis of the SMC collaboration.The RC,δA yµ,to the asymmetry A QEDµeshown inﬁgures1and2is deﬁned asδA yµ=A QEDµedσunpol.(4)The results may be summarized as follows.The O(α)QED RC to polarized elasticµe scattering were calculated for theﬁrst time using the variable yµ.A rather general FORTRAN codeµe la for this process was created allowing for the inclusion of kinematic cuts.Since under the conditions of the SMC experiment the corrections turn out to be small our calculation justiﬁes their neglection. 3Program HECTOR3.1Diﬀerent approaches to RC for DISThe radiative corrections to deep inelastic scattering are treated using two basic approaches. One possibility consists in generating events on the basis of matrix elements including the RC’s. This approach is suited for detector simulations,but requests a very hughe number of events to obtain the corrections at a high precision.Alternatively,semi-analytic codes allow a fast and very precise evaluation,even including a series of basic cuts andﬂexible adjustment to speciﬁc phase space requirements,which may be caused by the way kinematic variables are experimentally measured,cf.[2,5].Recently,a third approach,the so-called deterministic approach,was followed,cf.[10].It treats the RC’s completely exclusively combining features of fast computing with the possibility to apply any cuts.Some elements of this approach were used inµe la and in the branch of HECTOR1.11,in which DIS with tagged photons is calculated.Concerning the theoretical treatment three approaches are in use to calculate the radiative corrections:1)the model-independent approach(MI);2)the leading-log approximation(LLA); and3)an approach based on the quark-parton model(QPM)in evaluating the radiative correc-tions to the scattering cross-section.In the model-independent approach the QED corrections are only evaluated for the leptonic tensor.Strictly it applies only for neutral current processes.The hadronic tensor can be dealt with in its most general form on the Lorentz-level.Both lepton-hadron corrections as well as pure hadronic corrections are neglected.This is justiﬁed in a series of cases in which these corrections turn out to be very small.The leading logarithmic approximation is one of the semi-analytic treatments in which the diﬀerent collinear singularities of O((αln(Q2/m2l))n)are evaluated and other corrections are neglected.The QPM-approach deals with the full set of diagrams on the quark level.Within this method,any corrections(lepton-hadron interference, EW)can be included.However,it has limited precision too,now due to use of QPM-model itself. Details on the realization of these approaches within the code HECTOR are given in ref.[5,11].3.2O (α)QED Corrections for Polarized Deep Inelastic ScatteringTo introduce basic notation,we show the Born diagramr rr r j r r r r l ∓( k 1,m )l ∓( k 2,m )X ( p ′,M h )p ( p ,M )γ,Z ¨¨¨¨B ¨¨¨¨£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡z r r r r r r r r r r r r r rr ¨¨¨¨B ¨¨¨¨r r r r j r r r r and the Born cross-section,which is presented as the product of the leptonic and hadronic tensordσBorn =2πα2p.k 1,x =Q 2q 2F 1(x,Q 2)+p µ p ν2p.qF 3(x,Q 2)+ie µνλσq λs σ(p.q )2G 2(x,Q 2)+p µ s ν+ s µ p νp.q1(p.q )2G 4(x,Q 2)+−g µν+q µq νp.qG 5(x,Q 2),(8)wherep µ=p µ−p.qq 2q µ,and s is the four vector of nucleon polarization,which is given by s =λp M (0, n )in the nucleonrest frame.The combined structure functions in eq.(8)F1,2(x,Q2)=Q2e Fγγ1,2(x,Q2)+2|Q e|(v l−p eλl a l)χ(Q2)FγZ1,2(x,Q2)+ v2l+a2l−2p eλl v l a l χ2(Q2)F ZZ1,2(x,Q2),F3(x,Q2)=2|Q e|(p e a l−λl v l)χ(Q2)FγZ3(x,Q2),+ 2p e v l a l−λl v2l+a2l χ2(Q2)F ZZ3(x,Q2),G1,2(x,Q2)=−Q2eλl gγγ1,2(x,Q2)+2|Q e|(p e a l−λl v l)χ(Q2)gγZ1,2(x,Q2),+ 2p e v l a l−λl v2l+a2l χ2(Q2)g ZZ1,2(x,Q2),G3,4,5(x,Q2)=2|Q e|(v l−p eλl a l)χ(Q2)gγZ3,4,5(x,Q2),+ v2l+a2l−2p eλl v l a l χ2(Q2)g ZZ3,4,5(x,Q2),(9) are expressed via the hadronic structure functions,the Z-boson-lepton couplings v l,a l,and the ratio of the propagators for the photon and Z-bosonχ(Q2)=Gµ2M2ZQ2+M2Z.(10)Furthermore we use the parameter p e for which p e=1for a scattered lepton and p e=−1for a scattered antilepton.The hadronic structure functions can be expressed in terms of parton densities accounting for the twist-2contributions only,see[12].Here,a series of relations between the diﬀerent structure functions are used in leading order QCD.The DIS cross-section on the Born-leveld2σBorndxdy +d2σpol Borndxdy =2πα2S ,S U3(y,Q2)=x 1−(1−y)2 ,(13) and the polarized partdσpol BornQ4λp N f p S5i=1S p gi(x,y)G i(x,Q2).(14)Here,S p gi(x,y)are functions,similar to(13),and may be found in[6].Furthermore we used the abbrevationsf L=1, n L=λp N k 12πSy 1−y−M2xy2π1−yThe O(α)DIS cross-section readsd2σQED,1πδVRd2σBorndx l dy l=d2σunpolQED,1dx l dy l.(16)All partial cross-sections have a form similar to the Born cross-section and are expressed in terms of kinematic functions and combinations of structure functions.In the O(α)approximation the measured cross-section,σrad,is deﬁne asd2σraddx l dy l +d2σQED,1dx l dy l+d2σpol radd2σBorn−1.(18)The radiative corrections calculated for leptonic variables grow towards high y and smaller values of x.Theﬁgures compare the results obtained in LLA,accounting for initial(i)andﬁnal state (f)radiation,as well as the Compton contribution(c2)with the result of the complete calculation of the leptonic corrections.In most of the phase space the LLA correction provides an excellent description,except of extreme kinematic ranges.A comparison of the radiative corrections for polarized deep inelastic scattering between the codes HECTOR and POLRAD[17]was carried out.It had to be performed under simpliﬁed conditions due to the restrictions of POLRAD.Corresponding results may be found in[11,13,14].3.3ConclusionsFor the evaluation of the QED radiative corrections to deep inelastic scattering of polarized targets two codes HECTOR and POLRAD exist.The code HECTOR allows a completely general study of the radiative corrections in the model independent approach in O(α)for neutral current reac-tions including Z-boson exchange.Furthermore,the LLA corrections are available in1st and2nd order,including soft-photon resummation and for charged current reactions.POLRAD contains a branch which may be used for some semi-inclusive DIS processes.The initial state radia-tive corrections(to2nd order in LLA+soft photon exponentiation)to these(and many more processes)can be calculated in detail with the code HECTOR,if the corresponding user-supplied routine USRBRN is used together with this package.This applies both for neutral and charged current processes as well as a large variety of diﬀerent measurements of kinematic variables. Aside the leptonic corrections,which were studied in detail already,further investigations may concern QED corrections to the hadronic tensor as well as the interference terms. References[1]Proceedings of the Workshop on Physics at HERA,1991Hamburg(DESY,Hamburg,1992),W.Buchm¨u ller and G.Ingelman(eds.).[2]J.Bl¨u mlein,Z.Phys.C65(1995)293.[3]D.Bardin,L.Kalinovskaya and T.Riemann,DESY96–213,Z.Phys.C in print.[4]D.Bardin and L.Kalinovskaya,µe la,version1.00,March1996.The source code is availablefrom http://www.ifh.de/~bardin.[5]A.Arbuzov,D.Bardin,J.Bl¨u mlein,L.Kalinovskaya and T.Riemann,Comput.Phys.Commun.94(1996)128,hep-ph/9510410[6]D.Bardin,J.Bl¨u mlein,P.Christova and L.Kalinovskaya,DESY96–189,hep-ph/9612435,Nucl.Phys.B in print.[7]SMC collaboration,D.Adams et al.,Phys.Lett.B396(1997)338;Phys.Rev.D56(1997)5330,and references therein.[8]A.I.Nikischov,Sov.J.Exp.Theor.Phys.Lett.9(1960)757;P.van Nieuwenhuizen,Nucl.Phys.B28(1971)429;D.Bardin and N.Shumeiko,Nucl.Phys.B127(1977)242.[9]T.V.Kukhto,N.M.Shumeiko and S.I.Timoshin,J.Phys.G13(1987)725.[10]G.Passarino,mun.97(1996)261.[11]D.Bardin,J.Bl¨u mlein,P.Christova,L.Kalinovskaya,and T.Riemann,Acta Phys.PolonicaB28(1997)511.[12]J.Bl¨u mlein and N.Kochelev,Phys.Lett.B381(1996)296;Nucl.Phys.B498(1997)285.[13]D.Bardin,J.Bl¨u mlein,P.Christova and L.Kalinovskaya,Preprint DESY96–198,hep-ph/9609399,in:Proceedings of the Workshop‘Future Physics at HERA’,G.Ingelman,A.De Roeck,R.Klanner(eds.),Vol.1,p.13;hep-ph/9609399.[14]D.Bardin,Contribution to the Proceedings of the International Conference on High EnergyPhysics,Warsaw,August1996.[15]M.Gl¨u ck,E.Reya,M.Stratmann and W.Vogelsang,Phys.Rev.D53(1996)4775.[16]S.Wandzura and F.Wilczek,Phys.Lett.B72(1977)195.[17]I.Akushevich,A.Il’ichev,N.Shumeiko,A.Soroko and A.Tolkachev,hep-ph/9706516.-20-18-16-14-12-10-8-6-4-200.10.20.30.40.50.60.70.80.91elaFigure 1:The QED radiative corrections to asymmetry without experimental cuts.-1-0.8-0.6-0.4-0.200.20.40.60.810.10.20.30.40.50.60.70.80.91elaFigure 2:The QED radiative corrections to asymmetry with experimental cuts.-50-40-30-20-100102030405000.10.20.30.40.50.60.70.80.91HectorFigure 3:A comparison of complete and LLA RC’s in the kinematic regime of HERMES for neutral current longitudinally polarized DIS in leptonic variables.The polarized parton densities [15]are used.The structure function g 2is calculated using the Wandzura–Wilczek relation.c 2stands for the Compton contribution,see [6]for details.-20-100102030405000.10.20.30.40.50.60.70.80.91HectorFigure 4:The same as in ﬁg.3,but for energies in the range of the SMC-experiment.-20-10010203040500.10.20.30.40.50.60.70.80.91HectorFigure 5:The same as in ﬁg.4for x =10−3.-200-150-100-5005010015020000.10.20.30.40.50.60.70.80.91HectorFigure 6:A comparison of complete and LLA RC’s at HERA collider kinematic regime for neutral current deep inelastic scattering oﬀa longitudinally polarized target measuring the kinematic variables at the leptonic vertex.。

编辑行为准则及最佳实践指南

期刊编辑行为准则以及最佳实践指南2. 与读者的关系2.1. 读者有权了解该研究或其它学术工作的资助状况，以及该资助者在研究和文章发表过程中的作用。

编辑最佳实践应包括： –确保所发表的研究报告和综述已经由适当的有资格的审稿人评审过(包括适当的统计学评审) –确保期刊中非同行评审的部分已经做了清晰的标注 –采用促进研究报告准确性、完整性和清晰度的流程，包括技术编辑和使用适当的指南和清单(如MIAME1, CONSORT2等) –考虑制定透明化政策，鼓励最大化披露非研究文章的来源3 –采用作者或者投稿者系统，推广好的做法(如作者名单必须准确地反映实际贡献者)4，阻止不当行为(如影子作者和名誉作者) –将编辑部人员或编委会成员的投稿要接受客观和公正评审的步骤告知读者3. 与作者的关系3.1. 编辑应根据文章的重要性、原创性、清晰度、研究的真实性及其与期刊的相关性做出接受或拒稿的决定。

3.2. 除非在稿件中发现了严重的问题，否则编辑不应改变对稿件已做出的决定。

3.3. 除非发现了严重的问题，否则后一位编辑不应推翻前一位编辑做出的稿件发表的决定。

3.4. 应公开同行评审的流程，而对偏离该流程的任何特殊做法，编辑应做好解释的准备。

3.5. 期刊应该有申诉机制，允许作者对编辑决定提出申诉。

3.6. 编辑应公布作者所需要的详尽指南，该指南应定期更新，并应参照或链接到本准则。

3.7. 编辑应提供满足相关领域标准的作者署名权和/或实际投稿者的判别指南。

编辑最佳实践应包括： –定期检查作者须知，并链接到相关指南(参见国际医学期刊编辑委员会ICMJE5以及”负责任的研究出版：作者国际标准”6) –向投稿者公布相关利益冲突声明；如果出版后被揭露出来存在利益冲突，则必须发布更正 –确保选择适当的审稿人评审稿件(即那些能够对工作做出判断，且没有不合适利益冲突的专家) –如果作者要求某专家回避评审其稿件，并且这一要求是合理的和可行的，则应给予尊重期刊编辑行为准则以及最佳实践指南 –在涉嫌行为不当或作者署名权有争议的情况下，按照COPE流程图处理(http:///flowcharts) –公布处理涉嫌行为不当案件的细节(例如，链接到COPE流程图) –公布文章的投稿和接受日期4. 与审稿人的关系4.1. 编辑应提供审稿人所需要的详尽指南，包括如何保密处理所提交的材料。

高科计算器用户手册说明书

General Guide (3)Turning on or off (3)Battery replacement (3)Auto power-off function (3)Reset operation (3)Contrast adjustment (3)Display readout (4)Before Starting Calculation (4)Using " MODE " keys (4)Using " SET UP " keys (5)Using Math Mode (5)Using " 2nd " " ALPHA " Keys (6)Making corrections during Input (6)Error Position Display Function (6)Replay function (6)Memory calculation (7)Order of operations (7)Accuracy and Capacity (8)Error conditions (9)Basic Calculations (10)Arithmetic calculation (10)Parentheses calculations (10)Percentage calculation (11)Display notations (11)Answer Function (11)Scientific Function Calculations (11)Logarithmic and Exponential functions (12)Fraction calculation (12)Angle unit conversions (12)Sexagesimal ↔ Decimal transformation (13)Trigonometric / Inverse-Tri. functions (13)Hyperbolic / Inverse-Hyp. functions (13)Coordinates transformation (13)E – 1Probability (13)Other functions ( √, , , x-1,x2,x3, x y , Abs, RND ) (14)Multi-statement Function (14)Statistical Calculations (14)To Enter data for statistical analysis (15)To analyze data you have entered (15)To view or change data (17)Function Table (17)E – 2"" to "" to let you know memory is running low. If you still need to input more, you should divide your calculation into two or more parts.It displays a result of up to 10 digits, as well as a decimal, a negative sign, a " x10 " indicator, and a" means the calculator is in insert mode. The horizontal blinking cursor "" means the calculator is in By default, the calculator is in insert mode. In linear format, you can press [ 2nd ] [ INS ] to switch between the two modes, whereas in Math format, you can use only the insert mode." will be deleted or inserted after you press [ DEL ] or enter a new character" will be deleted by [ DEL ] key or replaced by any new character you enter.To clear all characters, simply press [ AC ] in either mode.Error Position Display FunctionP R, R Psin, cos, tan, sincosh , tanh√ln,log,8) xMultiplication sign omitted immediately before function with parentheses: for example, 3R P P R DMSx + y i = r (cosθ+ i sinθ)(Note) : When using those keys, make sure the calculator is set for the angle unit you want.The calculator can perform the conversion between rectangular coordinates and polar coordinates by [ 2nd ] [ P R ] and [ 2nd ] [ R P ]. See Example 29~30.ProbabilityThis calculator provides the following probability functions (See Example 31~34.):[ nPr ] Calculates the number of possible permutations of n item taken r at a time.E – 13。

机械通气临床应用指南(中华重症医学分会2024)

机械通气临床应用指南中华医学会重症医学分会（2024年）引言重症医学是探讨危重病发生发展的规律，对危重病进行预防和治疗的临床学科。

器官功能支持是重症医学临床实践的重要内容之一。

机械通气从仅作为肺脏通气功能的支持治疗起先，经过多年来医学理论的发展及呼吸机技术的进步，已经成为涉及气体交换、呼吸做功、肺损伤、胸腔内器官压力及容积环境、循环功能等，可产生多方面影响的重要干预措施，并主要通过提高氧输送、肺脏爱护、改善内环境等途径成为治疗多器官功能不全综合征的重要治疗手段。

机械通气不仅可以依据是否建立人工气道分为“有创”或“无创”，因为呼吸机具有的不同呼吸模式而使通气有众多的选择，不同的疾病对机械通气提出了具有特异性的要求，医学理论的发展及循证医学数据的增加使对呼吸机的临床应用更加趋于有明确的针对性和规范性。

在这种条件下，不难看出，对危重病人的机械通气制定规范有明确的必要性。

同时，多年临床工作的积累和多中心临床探讨证据为机械通气指南的制定供应了越来越充分的条件。

中华医学会重症医学分会以循证医学的证据为基础，采纳国际通用的方法，经过广泛征求看法和建议，反复仔细探讨，达成关于机械通气临床应用方面的共识，以期对危重病人的机械通气的临床应用进行规范。

重症医学分会今后还将依据医学证据的发展及新的共识对机械通气临床应用指南进行更新。

指南中的举荐看法依据2024年ISF提出的Delphi分级标准(表1)。

指南涉及的文献依据探讨方法和结果分成5个层次，举荐看法的举荐级别依据Delphi分级分为A E级，其中A 级为最高。

表1 Delphi分级标准举荐级别A 至少有2项I级探讨结果支持B 仅有1项I级探讨结果支持C 仅有II级探讨结果支持D 至少有1项III级探讨结果支持E 仅有IV级或V探讨结果支持探讨课题分级I 大样本，随机探讨，结果清楚，假阳性或假阴性的错误很低II 小样本，随机探讨，结果不确定，假阳性和/或假阴性的错误较高III 非随机，同期比照探讨IV 非随机，历史比照和专家看法V 病例报道，非比照探讨和专家看法危重症患者人工气道的选择人工气道是为了保证气道通畅而在生理气道与其他气源之间建立的连接，分为上人工气道和下人工气道，是呼吸系统危重症患者常见的抢救措施之一。

微软UltraMap 3.0：高级空中图像处理系统说明书

Ortho GenerationEssentials Dense MatchingAerial TriangulationRadiometryHighly advanced photogrammetric workflow system for UltraCam imagesMicrosoft UltraMap is a state-of-the-art, end-to-end, completephotogrammetric workflow system that provides highly automatedprocessing capabilities to allow organizations to rapidly generatequality data products from an UltraCam flight. UltraMap is designedto process huge amount of UltraCam data in the shortest possibletime with the highest degree of automatization, supported by guided manual interaction, quality control tools and powerful visualization. With version 3, UltraMap continues its innovation trend that has already delivered groundbreaking features such as monolithic stitching and automatic project-based color balancing for homogeneous image block color correction, but now also provides revolutionary, automated 3D data generation and ortho image processing features.UltraMap v3 now includes:• High-density 3D point cloud generation, with a point density of several hundred points per square meter, derived from an UltraCam photo mission• Highly accurate and detailed digital surface model (DSM) generation• Filtering of a DSM into a digital terrain model (DTM)• Generation of DSMOrtho (orthomosaic based on an automatically generated DSM) and DTMOrtho (traditional ortho mosaic) images UltraMap v3 delivers exceptional quality DSMOrthos and DTMOrthos athigh accuracies and without any manual interaction, since the UltraMapv3 ortho mosaicking approach takes into account all available inputs(i.e. a DSM and the automatically generated DTM). UltraMap v3 is able to generate seamlines at desired paths; remaining seamline editing for challenging regions is made using UltraMap’s DragonFly technology, a responsive visualization engine that allows users to conduct quality control on large image blocks in a quick and smooth fashion.UltraMap v3 is the first fully integrated and interactive photogrammetric workflow solution to provide premium UltraCam data processing from ingest of raw data to delivery of point clouds, DSMs and ortho imagery.ModulesUltraMap/Essentials | The UltraMap/Essentials module is responsible for converting the raw images taken by the UltraCam intostandard file formats that can be used by further processing steps in UltraMap and/or third party software systems. The UltraMap/Essentials module is divided into two processing steps:UltraMap/RawDataCenter | the UltraMap/RawDataCenter step is responsible for processing the UltraCamimagery from level-0 to level-2. By exploiting the distributed UltraMap Framework, processing tasks can be handled inparallel.UltraMap/Radiometry | the UltraMap/Radiometry step is responsible for defining the final color of thelevel-2 data. It also provides model-based radiometric correction to compensate for or remove hotspots, atmosphericeffects and haze, exploiting Dragonfly technology for image interaction and visualization of large image blocks.UltraMap/AT | the Aerial triangulation (AT) module provides an interactive workflow while calculating image correspondences in order to generate a precise exterior orientation for an entire image block by means of a least-squares bundle adjustment.UltraMap/DenseMatcher | the UltraMap/DenseMatcher module creates high-density point clouds and DSMs and DTMs from level-2 images, extrapolating precise exterior orientation data to generate per-pixel height values. The 3D point cloud and the DSM data can be exported in standard file formats for further 3rd party processing.UltraMap/OrthoPipeline | the UltraMap/OrthoPipeline module generates the final ortho mosaic from all available inputs such as level-2 imagery, AT results, radiometric settings, and the DSM/DTM. Two different ortho images can be generated:DSMOrthos and DTMOrthos.UltraMap/EssentialsThe UltraMap/RawDataCenter step of the UltraMap/Essentials module is responsible for downloading and processing of UltraCamimages from level-0 to level-2, including:• Geometrical corrections• Monolithic stitching• Radiometric corrections• Generation of the UltraMap project fileGeometrical corrections: UltraCam images are captured during aerial acquisition and stored in the RawData Format. Each shot position contains a number of sub-images. Each sub image corresponds to one single CCD sensor array and needs to be processed and converted by means of image stitching. This stitching process makes use of the overlapping footprint areas of the CCD sensor arrays. A larger number of points of interest are automatically detected and corresponding positions are computed by means of image correlation. The quality of this correlation process is at a 1/20 of a pixel magnitude, given that the image content of the analyzed region is very similar (no differences in the image content caused from perspective foreshortening and same lighting condition).Furthermore the Laboratory Calibration plays a significant role in this process and allows estimation of point positions to avoid mismatch and larger search areas. Metadata information, such as temperature readings, is included in order to describe the conditions of the camera for a distinct position at the moment of image capture. The image geometry is computed based on the stitching process (including panchromatic overlaps and color band information [cf. Monolithic Stitching]).The result of this process is the so-called level-2 image. It contains the high-resolution panchromatic image at the 16-bit per pixel data range and the 4-band multispectral image at 16-bit per band data format. The images are geometrically corrected and multispectral data are co-registered to the panchromatic image. It is worth noting that radiometric corrections are also applied to level-2 images based on the laboratory calibration (cf. radiometric corrections). As level-2 images are stored at 16-bit per band the radiometric domain is a linear domain without any logarithmic modification. Thus, one may call the level-2 image the “Digital transparency”.Stitching results are well documented by UltraMap. Thus one may study details of the level-2 processing and the stitching (left) or enjoy thecomprehensive overview with color-coded image frames (right).Monolithic stitching: The monolithic stitching generates one full frame PAN image out of the nine PAN sub-images taken by the camera. It uses information from the overlap between the nine sub-images as well as information from the full frame color cones to collect the tie points used for the stitching. This leads to a set of strong tie points between the sub-images even under critical conditions, such as images containing water bodies or images with unstructured terrain, such as sand desert. As a result, the full PAN frame of an UltraCam has a very robust and high accuracy literally as if it were collected by one large CCD through one lens. However the use of multiple smaller CCDs has significant benefits such as much higher image dynamic compared to single large CCDs. So, the monolithic stitching of UltraMap enables combining the benefits of image quality of smaller CCDs with the accuracy of large CCDs by avoiding the disadvantages of the latter. The overlap areas of CCD footprints and the resulting point distribution can be seen below. Stitching between panchromatic image areas allow collection of a large number of points at distinguished areas (left) and full frame distribution based on the color channel (right).Radiometric corrections: The radiometric correction is based on the radiometric parameters of the camera which are estimated during the Laboratory Calibration procedure. The parameters contain all information about the lenses, mechanical shutters and CCD detector arrays.Thus, the radiometric behavior of the camera is already known at a distinct quality level and can be adopted during the processing from raw images (level-0) to level-2. For this data, different F-stop settings are considered and the resulting vignetting masks are made available to the process.In a second step, the results from the radiometric analysis of CCD overlap areas is used to fine-tune the radiometric correction and remove any visible difference from adjacent image areas. Again the full frame color band contributes to this procedure and thus the monolithic stitching procedure also has an important benefit to the radiometric correction.A Vignetting Mask (left) and a shutter control diagram (right) are shown below as results from the radiometric laboratory calibration procedure.UltraMap Project File: This file is generated fully automatically during the first step of the processing. The file contains all important data and metadata of the distinct aerial project such as image file names, directory structure, camera parameters and initial exterior orientation data, as well as results from the ongoing processing. The UltraMap Project File has the extension .dfp and contains the basic information to allow any further automated processing of the entire photo mission. Below the Project File (e.g. UCEf80.dfp) can be recognized directly within the selected project folder listing.The Radiometry step of the UltraMap/Essentials module is responsible for defining the final color of the level-2 input data and togenerate level-3 output data. The step is fully automated and provides a rich feature set to adjust the color appearance of single images as well as the appearance of a whole block. However, deep manual interaction is possible to fine-tune the results to specific needs.Examples of the feature set are:• Automated, model-based radiometric correction to compensate for or remove hotspots and/or atmospheric effects such as haze• Project based color balancing (PBCB) for automated color correction of whole blocks. Effects such as different exposures, different illumination conditions and different flying time are corrected automatically• Smooth visualization and interaction of small and large blocks by the Dragonfly technology• Easy and intuitive user interface based on modern GUI technology and instant feedback• Full support of 16-bit workflow guarantees lossless computation of images• Various output formats for level-3 such as TIFF, 16bit TIFF, JPEG, single band, 3 band or 4 bandThe UltraMap/Essentials module is supported by the Dragonfly technology for the visualization and by the framework for distributed processing. This enables UltraMap to scale depending on throughput needs and IT infrastructure. Features such as distributed parallel processing (multi-core processing) with automated load balancing optimize throughput in heterogeneous networks without requiring any user interaction. The framework enables parallel processing on single computers as well as on small, medium and large multi-core systems.UltraMap/ATUltraMap/AT is the aerial triangulation module of UltraMap, optimized for UltraCam to deliver utmost quality. It provides an interactive workflow while calculating image correspondence to generate a precise exterior orientation for an entire image block. UltraMap/AT also focuses on a high degree of intelligent automatization. Wherever interaction is required, UltraMap/AT is designed to keep this interaction at a minimum, make it efficient and provides significant guidance for the interaction, such as the manual guided tie point improvement in the rare case that the automated tie-point collection did not provide the best possible results.Features of UltraMap/AT are:• Drag & Drop of GCPs• Uses in-flight GPS information for initial orientation• Single and multi-projection for ground control points• Initialization of project-based color balancing• Robust and automated tie point collection:• Guided manual point measurement (control points and tie points)• Auto-completion for manual point measurement• High accuracy due to a combination of feature-based and least-squares image matching• Sophisticated image-based tie point thinning for optimal coverage • Integrated photogrammetric bundle adjustment • Support for GPS/IMU data as a constraint for the bundle adjustment • Graphical overlays for AT results • Blunder detection, data snooping • Sub-block support • Visualized AT Report • Full support for all UltraCam cameras • Full support of 16-bit workflow • Supports scalable processing environments • Smooth visualization and interaction of small and large blocks by the Dragonfly technology• Easy and intuitive user interface•Full support of 16-bit workflowUltraMap/DenseMatcherA significant change in photogrammetry has been achieved by Multi-Ray Photogrammetry which became possible with the advent of the digital camera, such as the UltraCam, and a fully digital workflow by software systems such as UltraMap. This allows for significantly increased forward overlap as well as the ability to collect more images but virtually without increasing acquisition costs. However, Multi-Ray Photogrammetry as a first step is not a new technology; it is a specific flight pattern with a very high forward overlap (80%, even 90%) and an increased sidelap (up to 60%). The result is a highly redundant dataset that allows automated “dense matching” to generate high resolution, highly accurate point clouds from the imagery by matching the pixels of the overlapping images automatically.The UltraMap/DenseMatcher automatically generates point clouds from a set of overlapping UltraCam images. This is done by “pixel based matching” between all image pairs available for a given location on the ground. The precise exterior orientation is extrapolated and generates a height value (z-value) for a given pixel (for a given x, y, location). The redundancy of the image data set leads to multiple observations of z-values for a given location which will then be fused into one precise 3D measurement using sophisticated fusion algorithms. The remarkably high point density of the point cloud is typically of several hundred points per square meter.The achievable height accuracy of the point cloud is usually better than the GSD of the underlying images, thus a 10cm imagery leads to <10cm height accuracy of the resulting point cloud. This detailed and precise point cloud is used to generate a digital surface model (DSM). Thanks tothe high point density, this DSM has remarkably sharp edges and a very high level of detail.The next step after the DSM generation is the processing of a DTM. The DTM is processed out of the DSM using a hierarchical algorithm developed by Microsoft.Outputs of the UltraMap/DenseMatcher are:• considerably dense point clouds• Digital surface model (DSM)All outputs are available in standard formats for easy ingest into third party software systems. The digital terrain model (DTM) is currently onlybeing used internally in the UltraMap/OrthoPipeline for DTMOrtho image processing.UltraMap/OrthoPipelineMicrosoft UltraMap v3 introduces a fully automated processing pipeline for DSMOrtho and DTMOrtho generation.The DSMOrtho image is an ortho image which has been generated by rectifying the image, using the automatically generatedDSM. This leads to a special ortho image with no perspective view and no leaning objects, which has significant benefits in someapplications. Due to the consistent workflow, the DSMOrthos generated by UltraCam and UltraMap are of remarkably high-quality with very sharp edges, very detailed structures such as roof structures, and very little artifacts. That is because the dataset (DSM and images) comes from the same flight and no time difference has caused any changes on ground which could result in artifacts. Another reason for the high quality is theextremely sharp and precise DSM that has been processed from the point cloud, thanks to the high point density of the point cloud.The DTMOrtho is the traditional ortho image, processed by rectifying the images with a DTM that has also been generated automatically by the UltraMap/DenseMatcher. The seam lines have been generated automatically using information from the image content as well as from the heightfield. Manual editing tools support seamline optimization.RGB-DSMOrtho CIR-DSMOrthoThe UltraMap/OrthoPipeline consists of several steps which are performed in a sequence:Ortho rectification: the first step in the UltraMap/OrthoPipeline is called ortho rectification which re-projects the input images on a defined proxy geometry such as the DSM or the DTM. Depending on the type of the geometry used for the rectification, the result will be either a DSMOrtho or a DTMOrtho image.Seamline generation: after the ortho rectification process, the next step is the seamline computation between the rectified images. Seamscorrespond to transitions from an input image to the adjacent one.Ortho compositing: Once the initial ortho process is done, the software offers automated functionality to blend image content together in order to create a visually appealing result. All image bands (RGB and Near Infrared) are processed simultaneously in a consistent way.Processing EnvironmentThe UltraMap v3 processing pipeline is a highly scalable processing system that adapts flexibly to the IT environment.Key features and requirements are:• Use of mid-to-high-end standard Windows PCs is possible, allowing the use of existing infrastructure• Distributed processing in heterogeneous networks with automated load balancing ensure optimal usage of resources• Time guided machine allows to use of dedicated machines at dedicated time slots (e.g. using a workstation for UltraMap processing during night time).• Licensing scheme allows a wide spectrum of throughput needs. UltraMap can literally be executed on a laptop as well as on a processing system consisting of tens, or dozens or even hundreds of CPU cores and, as an option, additional GPU cores• Licensing scheme supports parallel setup of small field processing hubs (e.g. for immediate on-site quality checks after a flight) as well as setup of small, medium and large processing centers• GPU nodes deliver high-speed ups as the dense matching is ideal for a SIMD architecture such as graphics cards. Usage of CPU versus GPU can be configured to balance throughput• New V3 machines (resource intensive machines) provide high performance—an entire machine can be used to work on one task at a time. V3 machines can either be configured as CPU only or as GPU-enabled nodes.An UltraMap processing system usually consists of one or several front-end machines that are used to interact with the data and are not designed for processing. In addition, one or multiple processing machines are connected to the front end machine(s) and the data server(s). The processing machines handle data processing and may consist of multiple CPU and/or GPU nodes. The servers host the input, intermediate and final data. A very important part of the processing environment is the network required to transfer the data efficiently between front end, processing machines and servers.RGB-DTMOrtho CIR-DTMOrtho|*********************。

《中华人民共和国食品卫生法》(英文版)

《中华人民共和国食品卫生法》(英文版)Order of the President of the People’s Republic of ChinaNo. 59The Food Hygiene Law of the People’s Republic of China, Adopted at the 16th Meeting of the Standing Committee of the Eighth National People's Congress on October 30, 1995, promulgated by Order No. 59 of the President of the People's Republic of China on October 30, 1995, is hereby promulgated and shall enter into force as of the date of promulgation.Jiang ZeminPresident of the People’s Repu blic of ChinaOctober 30,1995Food Hygiene Law of the People’s Republic of China(Adopted at the 16th Meeting of the Standing Committee of the Eighth National People's Congress on October 30, 1995, promulgated by Order No. 59 of the President of the People's Republic of China on October 30, 1995, and effective as of the date of promulgation)ContentsChapter IGeneral ProvisionsChapter IIFood HygieneChapter IIIHygiene of Food AdditivesChapter IVHygiene of Containers, Packagings, Utensils and Equipment Used for Food Hygiene ControlChapter VFormulation of Food Hygiene Standards and Regulations for Food Hygiene ControlChapter VIFood Hygiene ControlChapter VIIFood Hygiene SupervisionChapter VIIILegal ResponsibilityChapter IXSupplementary ProvisionsChapter IGeneral ProvisionsArticle 1 This Law is enacted for the purpose of ensuring food hygiene, preventing food contamination and harmful substances from injuring human health, safeguarding the health of the people and improving their physical fitness.Article 2 The State institutes a system of food hygiene supervision.Article 3 The administrative department of public health under the State Council shall be in charge of supervision and control of food hygiene throughout the country.Other relevant departments under the State Council shall, within the scope of their respective functions and duties, be responsible for control of food hygiene.Article 4 Whoever engages in food production or marketing within the territory of the People's Republic of China must observe this Law.This Law applies to all foods and food additives as well as containers, packagings , utensils and equipment used for food, detergents and disinfectants; it also applies to the premises, facilities and environment associated with food production or marketing.Article 5 The State encourages and protects the social supervision exercised by public organizations and individuals over food hygiene.Any person shall have the right to inform the authorities and lodge a complaint about any violation of this Law.Chapter IIFood HygieneArticle 6 Food shall be nontoxic and harmless, conform to proper nutritive requirements and have appropriate sensory properties such as colour, fragrance and taste.Article 7 Principal and supplementary foods intended specially for infants and preschool children shall conform to the nutritive and hygienic standards promulgated by the administrative department of public health under the State Council.Article 8 In the process of food production or marketing, the requirements for hygiene stated below shall be conformed to:(1) The environment inside and outside any food production or marketing establishment shall be kept clean and tidy; measures shall be taken to eliminate flies, rodents, cockroaches and other harmful insects and to remove conditions for their propagation; and a prescribed distance shall be kept from any toxic or harmful site;(2) An enterprise engaged in food production or marketing shall have workshops or other premises for the preparation of raw materials and for processing, packing and storage that are commensurate with the varieties and quantities of the products handled;(3) Appropriate facilities shall be made available for disinfectants, changing clothes, toilet, natural and artificial light, ventilation, prevention of spoilage, protection against dust, elimination of flies and rodents, washing of equipment, sewage discharge and the containment of garbage and other wastes;(4) The layout of installations and the application of technological processes shall be rational in order to prevent contamination between foods to be processed and ready-to-eat foods, and between raw materials and finished products; food must not be placed in contact with any toxic substance or filth;(5) Tableware, kitchenware and containers for ready-to-eat foods must be cleaned and disinfected prior to use; cooking utensils and other utensils must be washed after use and kept clean;(6) Any containers, packagings, utensils and equipment used for the storage, transportation, loading and unloading of food as well as the conditions under which these operations are carried out must be safe, harmless and kept clean in order to prevent food contamination;(7) Ready-to-eat foods shall be kept in small packets or in nontoxic, clean packaging materials;(8) All persons involved in food production or marketing shall maintain a constant standard of personal hygiene, taking care to wash their hands thoroughly and wear clean work clothes and headgear while preparing or selling food; also, proper utensils must be used when selling ready-to-eat foods;(9) Any water used must conform to the national hygiene standards for drinking-water in urban and rural areas;(10) The detergents and disinfectants used shall be safe and harmless to human health.The hygienic requirements for food production or marketing undertaken by food vendors and persons engaged in the food business in urban and rural markets shall be formulated specifically according to this Law by the standing committees of the people's congresses in the provinces, autonomous regions, or municipalities directly under the Central Government.Article 9 The production and marketing of foods in the following categories shall be prohibited:(1) foods that can be injurious to human health because they are putrid or deteriorated, spoiled by rancid oil or fat, moldy, infested with insects or worms, contaminated, contain foreign matter or manifest other abnormalities in sensory properties;(2) foods that contain or are contaminated by toxic or deleterious substances and can thus be injurious to human health;(3) foods that contain pathogenic parasites, microorganisms or an amount of microbial toxin exceeding the tolerance prescribed by the State;(4) meat and meat products that have not been inspected by the veterinary health service or have failed to pass such inspection;(5) poultry, livestock, game and aquatic animals that have died from disease, poisoning or some unknown cause, as well as products made from them;(6) foods contaminated by use of filthy or seriously damaged containers or packages, or filthy means of conveyance;(7) foods that impair nutrition or health because they are adulterated or misbranded;(8) foods processed with non-food raw materials; foods mixed with non-food chemical substances, or non-food stuffs used as food;(9) foods that has expired the date for guaranteed quality;(10) foods of which the sale has been specifically prohibited, for the prevention of diseases or other special reasons, by the administrative department of public health under the State Council or by the people's governments of the provinces, autonomous regions, or municipalities directly under the Central Government;(11) foods that contain additives not approved for use by the administrative department of public health under the State Council or residues of pesticides exceeding the tolerance prescribed by the State;(12) other foods that do not conform to the standards and requirements for food hygiene.Article 10 Food must not contain medicinal substances, with the exception of those materials that have traditionally served as both food and medicaments and are used as raw materials, condiments or nutrition fortifiers.Chapter IIIHygiene of Food AdditivesArticle 11 The production, marketing and use of food additives must conform to the hygiene standards for useof food additives and the hygiene control regulations; the food additives that do not conform to the hygiene standards and the hygiene control regulations may not be marketed and used.Chapter IVHygiene of Containers, Packagings, Utensils and Equipment Used for FoodArticle 12 Containers, packagings, utensils and equipment used for food mustconform to the hygiene standards and the hygiene control regulations.Article 13 The raw materials for making containers, packagings, utensils and equipment used for food must meet hygiene requirements. The finished products should be easy to clean and disinfect.Chapter VFormulation of Food Hygiene Standards and Regulations for Food Hygiene ControlArticle 14 The administrative department of public health under the State Council shall formulate or approve and promulgate the national hygiene standards, hygiene control regulations and inspection procedures for food, food additives, the containers, packagings, utensils and equipment used for food, the detergents and disinfectants used for washing food or utensils and equipment used for food, and the tolerances for contaminants and radioactive substances in food.Article 15 If the State has not formulated hygiene standards for a certain food, the people's governments of the provinces, autonomous regions, or municipalities directly under the Central Government may establish local hygiene standards for that food and report them to the administrative department of public health under the State Council and the competent standardization administration department under the State Council for the record.Article 16 Norms of significance to the science of health to be included in the national quality standards for food additives must be examined and approved by the administrative department of public health under the State Council.Appraisals on the safety for use of agricultural chemicals, such as pesticides and chemical fertilizers, shall be examined and approved by the administrative department of public health under the State Council.Veterinary hygiene inspection procedures for slaughtered livestock and poultry shall be formulated jointly by the relevant administrative departments under the State Council and the administrative department of public health under the State Council.Chapter VIFood Hygiene ControlArticle 17 The departments in charge of control of food production or marketing of the people's governments at various levels shall strengthen control of food hygiene and oversee the implementation of this Law.The people's governments at various levels shall encourage and support efforts to improve food processing technology so as to promote the improvement of hygienic quality of food.Article 18 Enterprises engaged in food production or marketing shall improve their own system for food hygiene control, appoint full-time or part-time workers to control food hygiene and strengthen inspection of the foods they produce or market.Article 19 The selection of sites and the designs for construction, extension or renovation projects of enterprises engaged in food production or marketing shall meet hygiene requirements, and the administrative department of public health must participate in the examination of those designs and in the inspection and acceptance of finished projects.Article 20 Before starting production of new varieties of food or food additives with new resources, theenterprises engaged in their production or marketing must submit the data required for evaluation of the hygiene and nutrition of such products; before starting production of new varieties of containers, packagings, utensils or equipment used for foods, with new raw or processed materials, the enterprises engaged in their production or marketing must submit the data required for evaluation of the hygiene of such products. Before the new varieties mentioned above are put into production, it shall also be necessary to provide samples of the varieties and the matter shall be reported for examination and approval in accordance with the specified procedures for examining and approving food hygiene standards.Article 21 Any standardized packaged food or food additive must, according to the requirements for different products, have the name of the product, the place of manufacture, the name of the factory, the date of manufacture, the batch number (or code number), the specifications, the formula or principal ingredients, the date of expiration for guaranteed quality, the method of consumption or use, and other such information indicated in the label of the package or the product description. The product description for any food or food additive shall not contain exaggerated or false advertising.The label of the food package must be clearly printed and easy to read. Foods sold on domestic markets must have labels in the Chinese language.Article 22 With regard to the food indicated to have specific health functions, the products and its description must be submitted to the administrative department of public health under the State Council for examination and approval; its hygiene standards and the measures for control of its production and marketing shall be formulated by the administrative department of public health under the State Council.Article 23 The food indicated to have specific health functions may not be harmful for human health; the content of the product description shall be true, and the functions and ingredients of the product shall be identical with the information given in the product description and there shall be no false information.Article 24 Food, food additives and containers, packagings and other utensils used specially for food may be dispatched from factory or sold only after their producers have carried out inspection and found them to be up to the standards according to the hygiene standards and the hygiene control regulations.Article 25 Whenever producers or marketers of food procure supplies, they shall, in accordance with the relevant State regulations, request inspection certificates or laboratory test reports and the supplier must provide these. The scopes and types of food that requires certificates shall be specified by the administrative department of public health of the people's governments of the provinces, autonomous regions, or municipalities directly under the Central Government.Article 26 All persons engaged in food production or marketing must undergo an annual medical examination; persons newly employed or serving temporarily in this field must also undergo a medical examination and may not start work until they have obtained health certificates.No persons suffering from dysentery, typhoid, viral hepatitis or other infectious diseases of the digestive tract (including pathogen carriers), active tuberculosis, suppurative or exudative dermatosis or any other disease incompatible with food hygiene, may be engaged in any work involving contact with ready-to-eat foods.Article 27 Enterprises engaged in food production or marketing as well as food vendors must obtain a hygiene licence issued by the administrative department of public health before they shall be permitted to apply for registration with the administrative departments of industry and commerce. No person who has not obtained a hygiene licence may engage in food production or marketing.Food producers or marketers may not forge, alter or lend the hygiene licence.The measures for the issuance and control of hygiene licence shall be worked out by the administrative departments of public health of the people's governments of the provinces, autonomous regions, or municipalities directly under the Central Government.Article 28 Persons who run a food market of any type shall be responsible for the food hygiene control of the market, set up necessary public sanitary facilities in the market and maintain a good sanitary environment.Article 29 The administrative departments of industry and commerce shall be responsible for the control of food hygiene on urban and rural markets; the administrative departments of public health shall be responsible for the supervision and inspection of food hygiene.Article 30 Imported foods, food additives and containers, packagings, utensils and equipment used for food must comply with the national hygiene standards and the hygiene control regulations.The above-mentioned imports shall be subject to hygiene supervision and inspection by the frontier agencies for hygiene supervision and inspection of imported food. Only those proved to be up to the standards through inspection shall be allowed to enter the territory. The Customs authorities shall grant clearance of goods on the strength of the inspection certificate.When declaring such products for inspection, the importer shall submit the relevant data and inspection reports on the pesticides, additives, fumigants and other such substances used by the exporting country (region).The imports mentioned in the first paragraph shall be subject to inspection in accordance with the national hygiene standards. In the absence of the national hygiene standards for such imports, the importer must provide the hygiene evaluation data prepared by the health authorities or organization of the exporting country (region) to the frontier agencies for hygiene supervision and inspection of imported food for examination and inspection and such data shall also be reported to the administrative department of public health under the State Council for approval.Article 31 Foods for export shall be subject to hygiene supervision and inspection by the national inspection agency for import and export commodities.The Customs authorities shall grant clearance of export commodities on the basis of the certificates issued by the national inspection agency for import and export commodities.Chapter VIIFood Hygiene SupervisionArticle 32 The administrative departments of public health of the local people's governments at or above the county level shall exercise their functions and duties for food hygiene supervision within the scope of their jurisdiction.The agencies for food hygiene supervision set up by the administrative departments of railways and communications shall exercise their functions and duties for food hygiene supervision jointly prescribed by the administrative departments of public health under the State Council and other relevant departments under the State Council.Article 33 The duties for food hygiene supervision shall be as follows:(1) to provide monitoring, inspection and technical guidance for food hygiene;(2) to contribute to the training of personnel for food production and marketing and to supervise the medical examination of such personnel;(3) to disseminate knowledge of food hygiene and nutrition, provide appraisals of food hygiene and publicize the existing situation in food hygiene;(4) to conduct hygiene inspection of sites selected or designs made for construction, extension or renovation projects of enterprises engaged in food production or marketing and participate in the inspection and acceptance of finished projects;(5) to undertake investigation of accidents involving food poisoning or food contamination and take measures of control;(6) to make supervision and inspection rounds to see whether any act is committed against this Law;(7) to pursue investigation of the responsibility of persons who violate this Law and impose administrativepunishment on them according to law;(8) to take charge of other matters that concern food hygiene supervision.Article 34 The administrative departments of public health of the people's governments at or above the county level shall be manned with food hygiene supervisors. Such supervisors shall be qualified professionals and issued with such certificates by the administrative departments of public health at the corresponding levels.The food hygiene supervisors appointed by departments in charge of railways and communications agencies shall be issued with the certificates by the competent authorities at a higher level.Article 35 Food hygiene supervisors shall carry out the tasks assigned to them by the administrative department of public health.Food hygiene supervisors shall enforce laws impartially, be loyal to their duties and may not seek personal gain by taking advantage of their office.While carrying out their tasks, food hygiene supervisors may obtain information from the food producers or marketers, request necessary data, enter production or marketing premises to inspect them, and get free samples in accordance with regulations. The producers or marketers may not turn down such requests or hold back any information.Food hygiene supervisors shall be obliged to keep confidential any technical data provided by the producers or marketers.Article 36 The administrative department of public health under the State Council and those of the people's governments of the provinces, autonomous regions, or municipalities directly under the Central Government may, if the need arises, assign qualified units as units for food hygiene inspection; these units shall undertake food hygiene inspection and provide inspection reports.Article 37 The administrative department of public health of the local people's governments at or above the county level may adopt the following temporary measures of control over the food producer or marketer when a food poisoning accident has occurred or when there is evidence of a potential food poisoning accident:(1) to seal up the food and its raw materials that have caused food poisoning or that are likely to cause food poisoning;(2) to seal up the contaminated utensils used for food and order the food producer or marketer to have them cleaned and disinfected.The food that is found to be contaminated after inspection shall be destroyed, while the food that is found not contaminated shall be unsealed.Article 38 The units where food poisoning accidents have occurred and the units that have admitted the victims for medical treatment shall, in addition to taking rescue measures, submit prompt reports to the local administrative departments of public health in accordance with relevant State regulations.The administrative department of public health of a local people's government at or above the county level shall, upon receipt of such report, conduct prompt investigation and handle the matter and adopt control measures.Chapter VIIILegal ResponsibilityArticle 39 Whoever, in violation of this Law, produces or markets food which is not up to the hygiene standards, thus causing an accident of food poisoning or resulting in a disease caused by food-borne bacteria, shall be ordered to stop such production or marketing; the food causing such food poisoning or disease shall be destroyed; the illegal gains shall be confiscated and a penalty of not less than one time and not more than five times the illegal gains shall concurrently be imposed; if there are no illegal gains, a penalty of not less than 1,000 yuan and not more than 50,000 yuan shall be imposed.Whoever, in violation of this Law, produces or markets food which is not up to the hygiene standards, thus causing a serious accident of food poisoning or resulting in a disease caused by food-borne bacteria, and seriously harming human health, or adulterates food he produces or markets with toxic or harmful non-food raw materials, shall be investigated for criminal responsibility according to law.If a person commits any of the acts mentioned in this Article, his hygiene licence shall be revoked.Article 40 If anyone, in violation of this Law, engages in food production or marketing without obtaining a hygiene licence or with a forged hygiene licence, such production or marketing shall be banned; the illegal gains shall be confiscated and a penalty of not less than one time and not more than five times the illegal income shall concurrently be imposed; if there are no illegal gains, a penalty of not less than 500 yuan and not more than 30,000 yuan shall be imposed. If anyone alters or lends his hygiene licence, his hygiene licence and the illegal gains shall be confiscated; and a penalty of not less than one time and not more than three times the illegal gains shall concurrently be imposed; if there are no illegal gains, a penalty of not less than 500 yuan and not more than 10,000 yuan shall be imposed.Article 41 If, in violation of this Law, any food producer or marketer does not comply with the hygiene requirements, he shall be ordered to set it right and given a disciplinary warning, and a penalty of not more than 5,000 yuan may be imposed; if he refuses to set it right or other serious circumstances are involved, his hygiene licence shall be revoked.Article 42 If anyone, in violation of this Law, produces or markets food the production and marketing of which is prohibited, he shall be ordered to stop producing or marketing such food, a public announcement shall be made immediately to recall the sold food and the food shall be destroyed; the illegal gains shall be confiscated and a penalty of not less than one time and not more than five times the illegal gains shall concurrently be imposed; if there are no illegal gains, a penalty of not less than 1,000 yuan and not more than 50,000 yuan shall be imposed; if the offence is serious, the offender's hygiene licence shall be revoked.Article 43 If anyone, in violation of this Law, produces or markets the principal and supplementary foods intended specially for infants and preschool children which do not conform to the nutritive and hygiene standards, he shall be ordered to stop producing and marketing such foods, a public announcement shall be made immediately to recall the sold foods and the foods shall be destroyed; the illegal gains shall be confiscated and a penalty of not less than one time and not more than five times the illegal gains shall concurrently be imposed; if there are no illegal gains, a penalty of not less than 1,000 yuan and not more than 50,000 yuan shall be imposed; if the offence is serious, the offender's hygiene licence shall be revoked.Article 44 If anyone, in violation of this Law, produces, markets or uses the food additives, food containers, packagings, utensils and equipment used for food as well as the detergents and disinfectants which do not conform to the hygiene standards and the hygiene control regulations, he shall be ordered to stop producing and using them; the illegal gains shall be confiscated and a penalty of not less than one time and not more than three times the illegal gains shall concurrently be imposed; if there are no illegal gains, a penalty of not more than 5,000 yuan shall be imposed.Article 45 If anyone, in violation of this Law, produces or markets the food indicated to have specific health functions without examination and approval by the administrative department of public health under the State Council, or if the product description of such food provides false information, he shall be ordered to stop producing or marketing such food, the illegal gains shall be confiscated and a penalty of not less than one time and not more than five times the illegal gains shall concurrently be imposed; if there are no illegal gains, a penalty of not less than 1,000 yuan and not more than 50,000 yuan shall be imposed; if the offence is serious, the offender's hygiene licence shall be revoked.Article 46 If anyone, in violation of this Law, does not indicate or falsely indicates specified matters such as。

英语六级改错试题：改错部分20篇(11)

洛基英语，中国在线英语教育领导品牌第十一篇：Error Correction (15 minutes)More people die of tuberculosis(结核病)than of any other disease caused bya single agent. This has probably been the case in quite a while. During the --71. early stages of the industrial revolution. Perhaps one in every seventh --72.deaths in Europe's crowded cities were caused by the disease. From --73.now on, Though, western eyes, missing the global picture, saw the trouble going --74. into decline. With occasional breaks for war, the rates of death andinfection in the Europe and America dropped steadily through the 19th and --75.20th centuries. In the 1950s,the introduction of antibiotics(抗菌素)strengthened the trend in rich countries, and the antibiotics were allowedto be imported to poor countries. Medical researchers declared victory and --76. withdrew. They are wrong. In the mid-1980s the frequency of infections and deaths --77.started to pick up again around the world. Where tuberculosis vanished, it --78. came back; in many places where it had never been away, it grew better. The --79. World Health Organization estimates that 1.7 billion people (a third of theearth's population) suffer from tuberculosis. Even when the infection ratewas falling, population growth kept the number of clinical cases more orless constantly at 8 million a year. Around 3 million of those people --80.died, nearly all of them in poor countries.答案：71. in→for72. seventh→seven73. were→was74. now→then75. 去掉Europe前的the76. imported→exported77. are→were78. tuberculosis∧vanished→had79. better→worse80. constantly→constant第十四篇：Error Correction (15 minutes)When you start talking about good and bad manners youimmediately start meeting difficulties. Many people just cannotagree what they mean. We asked a lady, who replied that shethought you could tell a well-mannered person on the way they --71.occupied the space around them - for example, when such aperson walks down a street he or she is constantly unaware of --72.others. Such people never bump into other people.However, a second person thought that this was more aquestion of civilized behavior as good manners. Instead, this --73. other person told us a story, it he said was quite well known, --74. about an American who had been invited to an Arab meal at --75.one of the countries of the Middle East. The American hasn't --76. been told very much about the kind of food he might expect. Ifhe had known about American food, he might have behaved --77. better.Immediately before him was a very flat piece of bread thatlooked, to him, very much as a napkin (餐巾）Picking it --78.up, he put it into his collar, so that it falls across his shirt. --79.His Arab host, who had been watching, said of nothing, but --80. immediately copied the action of his guest.And that, said this second person, was a fine example of good manners. 答案：71. on→by72. unaware→aware73. as→than74. it→which75. at→in76. hasn't→hadn't77. American→Arab78. as→like79. falls→fell80. of→删“成千上万人疯狂下载。

Chap 13. Pooling Cross Sections across Time(截面和面板数据分析,复旦大学,陆铭、张晏)解析

and dummy variables are used for all time periods (except, of course, the base period), the use of aggregate price deflators will only affect the intercepts; none of the slope estimates will change.
Yan Zhang School of Economics, Fudan University CCER, Fudan University
Analysis of Cross Section and Panel Data
Part 3. Some Advanced Topics
Chap 13. Pooling Cross Sections across Time
control group: not affected by the policychange treatment group: thought to be affected by the policys:
to control for systematic differences between the control and
1980.7.15: Kentucky raised the cap on weekly earnings that were covered by workers’ compensation. Problem: its effects on duration

influenced: high-income worker control group (low) and treatment group (high)

Electronic transport in two dimensional graphene

arXiv:1003.4731v2 [cond-mat.mes-hall] 5 Nov 2010
(Dated: November 9, 2010)
We provide a broad review of fundamental electronic properties of two-dimensional graphene with the emphasis on density and temperature dependent carrier transport in doped or gated graphene structures. A salient feature of our review is a critical comparison between carrier transport in graphene and in two-dimensional semiconductor systems (e.g. heterostructures, quantum wells, inversion layers) so that the unique features of graphene electronic properties arising from its gapless, massless, chiral Dirac spectrum are highlighted. Experiment and theory as well as quantum and semi-classical transport are discussed in a synergistic manner in order to provide a uniﬁed and comprehensive perspective. Although the emphasis of the review is on those aspects of graphene transport where reasonable consensus exists in the literature, open questions are discussed as well. Various physical mechanisms controlling transport are described in depth including long-range charged impurity scattering, screening, short-range defect scattering, phonon scattering, many-body eﬀects, Klein tunneling, minimum conductivity at the Dirac point, electron-hole puddle formation, p-n junctions, localization, percolation, quantum-classical crossover, midgap states, quantum Hall eﬀects, and other phenomena.

化工原理英文教材-分离-相间扩散和传质原理Principles of Diffusion and Mass Transfer Between Phases

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Logarithmic

Logarithmic transform coefficient histogram matching with spatialequalizationBlair Silver◊, Sos Agaian*, and Karen Panetta◊◊ Department of Electrical and Computer Engineering, Tufts University161 College Avenue, Medford, MA 02155* College of Engineering, The University of Texas at San Antonio6900 North Loop 1604 West, San Antonio, TX 78249-0669ABSTRACTIn this paper we propose an image enhancement algorithm that is based on utilizing histogram data gathered from transform domain coefficients that will improve on the limitations of the histogram equalization method. Traditionally, classical histogram equalization has had some problems due to its inherent dynamic range expansion. Many images with data tightly clustered around certain intensity values can be over enhanced by standard histogram equalization, leading to artifacts and overall tonal change of the image. In the transform domain, one has control over subtle image properties such as low and high frequency content with their respective magnitudes and phases. However, due to the nature of many of these transforms, the coefficient’s histograms may be so tightly packed that distinguishing them from one another may be impossible. By placing the transform coefficients in the logarithmic transform domain, it is easy to see the difference between different quality levels of images based upon their logarithmic transform coefficient histograms. Our results demonstrate that combing the spatial method of histogram equalization with logarithmic transform domain coefficient histograms achieves a much more balanced enhancement, that out performs classical histogram equalization.Keywords: Image enhancement, transform coefficient histogram, histogram equalization, histogram matching.1.INTRODUCTIONImage enhancement techniques strive for one major purpose: to improve some characteristic of an image. These enhancement techniques can be broken up into two major classifications: spatial domain enhancement and transform domain enhancement.Spatial domain techniques deal with the raw image data, altering the intensity values based on a specific algorithm’s set of criteria. These techniques can range from local filtering to global algorithms. A common example of a spatial technique is histogram equalization, which attempts to alter the spatial histogram of an image to closely match a uniform distribution. Histogram equalization treats the image globally and because of this suffers from being poorly suited for retaining local detail. It is also common that the equalization will over enhance the image, resulting in an undesired loss of visual data, of quality, and of intensity scale [6].Transform domain enhancement techniques involve transforming the image intensity data into a specific domain by using such methods as the DCT, Fourier, and Hartley transforms [2,7-9,11].These transforms are used to alter the frequency content of an image to improve desired traits, such as high frequency content. Many enhancement techniques have been proposed that attempt to enhance the image based upon other transform domains and their characteristics [2,7-9,11].Each of these methods has its strong points and its weak points. This leads to the question: is there a way to combine these styles of enhancement to return even better results? This paper will explore a new method for which a transformdomain based technique and a spatial technique can be combined to enhance images. The proposed algorithm will address visualizing and altering the transform coefficient histograms through histogram mapping and histogram equalization using the Discrete Cosine Transform (DCT). This paper will also demonstrate a quantitative measurement based upon contrast entropy to determine the efficacy and the optimization of the method.The paper is organized as follows: Section I lays out the difference between spatial and transform domain enhancement and briefly states the proposed algorithm. Section II defines the measure of algorithm performance, choosing optimal parameters, the logarithmic transform domain, and histogram equalization. Section III has an explanation of the logarithmic transform domain histogram matching with histogram equalization algorithm (LTHMHE) as well as an explanation of LTHMHE combined with alpha-rooting, and section IV is an analysis of the experimental results using this method. Section V is a discussion of the results and some concluding comments are made.2. BACKGROUNDIn this section, background topics necessary to understand the new method proposed are discussed. The measure of performance will be explored first followed by a method for choosing optimal parameters, a definition of the logarithmic transform domain, a definition of histogram equalization, and a definition of alpha-rooting.2.1 Measure of performanceMeasuring the performance of a given enhancement algorithm is a key step into understanding how effective a given method is. However, defining a proper measure of enhancement has proven to be a difficult task. It is important when implementing an image enhancement technique to create a suitable image enhancement measure, however the improvement resulting from the enhancement is often difficult to measure. This problem become more apparent when the enhancement algorithms are parameter based and one needs: a) to choose the best parameters; b) to choose the best transform among a class of unitary transforms; c) to automate the image enhancement procedures. The problem becomes especially difficult when an image enhancement procedure is used as a preprocessing step for other image processing purposes such as object detection, classification, and recognition. For this reason it becomes apparent that a measure must be designed based on a specific trait of the image.In the past, there have been many differing definitions of an adequate measure of performance based on contrast[1,3,4,11]. Gordon and Rangayan used local contrast defined by the mean gray values centered on a current pixel of two rectangular windows [4]. Begchladi and Negrate defined an improved version of the aforementioned measure by basing their method on local edge information of the image [1]. In the past, attempts at statistical measures of gray level distribution of local contrast enhancement (for example mean, variance, or entropy) have not been particularly useful or meaningful. A number of images, which show an obvious contrast improvement, showed no consistency, as a class, when using these statistical measurements. Morrow introduced a measure based on the contrast histogram, which has a much greater consistency than statistical measures [11].For simple patterns, two definitions of contrast measure have also been often used. One is the Michelson contrast measure ; the other is the Weber contrast measure. The Michelson contrast measure is used to measure the contrast of a periodic pattern such as a sinusoidal grating, while the Weber contrast measure assumes a large uniform luminance background with a small test target. Both measures are therefore unsuitable for measuring the contrast in complex images [10]. Many such modifications of the Weber contrast have been proposed [7-9]. Note that Fechner’s law gives a relationship between brightness and light intensity which is given by the following equation.)ln()ln(minmax max f f k f f k B ′+′= (1)Where k’ is a constant, and fmax and fmin are the maximum and minimum luminance values in a block of the image. Fechner’s law provides the basis for the contrast measure based on contrast entropy which was proposed and later modified by Agaian. [8,9].Definition [9]: Let an image I be split into 12k k × blocks (,)B k l with center (k,l) of size 12M M ×.An image enhancement or contrast measure with respect to transform Φ{{⎪⎭⎪⎬⎫⎪⎩⎪⎨⎧⎪⎭⎪⎬⎫⎪⎩⎪⎨⎧ΦΦ=Φ),(),(min max ;min;,max;,,par I par I AWC w l k w l k l k parameters (2)Where Φ is a given transform from class of fast unitary transforms (including wavelets), and max;,w k l I , min;,w k l I are themaximum and minimum luminance values in a block (,)B k l of the image and where the parameters are the processing enhancement algorithm parameters.Definition [8]: Modified image enhancement measure∑∑==ΦΦ=Φ212111;min;,max;21,,),(),(log 201)(k l k k w l k w l k k k par I par I k k EME α (3) 12,,()k k EME αΦ is called a measure of image enhancement or contrast measure with respect to transform Φ.Therefore, the optimal transform,Φ, is relative to the measure of enhancement, 0()EME EME Φ=.A simple modification to the above definition leads to another powerful measure of enhancement, as proposed also by Agaian [8].∑∑==ΦΦΦΦ=Φ212111;min;,max;;min;,max;21,)()(log )()(1)(k l k k w l k w l k wl k w l k k k I I I I k k EME(4)This is known as the measure of enhancement by entrop y, or EME [8]. This measure averages contrast entropy over a given image using a specified block size. To be as accurate as possible, it is reasonable to suggest using a smaller block size to make the data as representative as possible. For this paper, the measure of enhancement by entropy was used along with a block size of 4 by 4.We also wish to introduce the Michelson law based contrast measure :{}{}⎟⎟⎠⎞⎜⎜⎝⎛+−==∑∑==∈∈2111;min;,max;;min;,max;21log 201max ))((max k l k k w l k w l k w l k w l k I I I I k k EME EME φφφφφ (5) These definitions use the Michelson Contrast , or modulation, definition: the relation between the spread and the sum of the two luminances can be represented asModulation = (L max - L min ) / (L max + L min ) (6)The main idea behind this measure is to use the relationship between the spread and the sum of the two luminance values found in a small block. It then takes the average modulation in each block over the entire image. In the context of vision, such a relationship could be caused by scattered light introduced into the view path by a translucent object.{{})(max 21,,,Φ=Φk k AME AME αα(7) Another possible modification would be adaptation of the Michelson law based contrast measure to include contrast entropy. ∑∑==+−⎥⎦⎤⎢⎣⎡+−=Φ212111;min;,max;;min;,max;;min;,max;;min;,max;21,,log 1)(k l k k w l k w l k w l k w l k w l k w l k w l k w l k k k I I I I I I I I k k AME ααα (8)An example of the AWC, EME, EME of Entropy, Michelson Law EME, and AME plotted versus an enhancement parameter, alpha, can be found in Figure 1. Depending on the measure of enhancement, different measures will be more useful than others. Our proposed method works best with the measures based upon entropy such as the EME of Entropy and the AME. For this paper, the EME of Entropy, equation 4, will be used to measure results.(a) (b) (c)(d) (e) (f)Figure 1: (a) Original Pentagon Image, (b-f) Graphs of alpha vs AWC, EME, EME of Entropy, Michelson Law EME, AME. 2.3 Logarithmic transform domain:The transform domain affords us the ability to view the frequency content of an image. It conveniently breaks up the data in regions of lower and higher frequency. However, the histogram of this data is usually less telling and may require another type of transformation. This is because a plot of the histogram of a typical image is compact and uninformative, as shown in Figure 2a.(a) (b)Figure 2: (a) DCT-2 transform domain histogram (b) Logarithmic DCT-2 transform domain histogramBy taking the logarithm of the data, this problem can be avoided. This is done in primarily two steps. The first step requires the creation of a matrix to preserve the phase of the transform image, which is given by the equationθ(8)angleXji=))),((,(jiWhere the angle function returns the angle of the coefficient. This will be used to restore the phase of the transform coefficients. The next step is to take the logarithm of the modulus of the coefficients as shown by the equationˆ(,)ln((,))X i j X i j γηλ=+ (9)Where η, γ, and λ are enhancement parameters, usually set to 1. The shifting coefficient, λ, is needed to keep returning the logarithm of zero, which is undefined. The shifting, in itself, enhances the contrast of the image, though only slightly. This results in a much more visible version of the histogram as shown in Figure 2b. To return the coefficients to the standard transform domain the signal is exponentiated and the phase is restored as shown by),(),(ˆ),(j i j j i X e e j i X θ⋅=′ (10)This preserves the overall image characteristics, ensuring that the returned image is visually similar to the original image, and that the enhancement only plays upon the magnitude of the transform coefficients.This process works with real and complex orthogonal transforms. It is important to keep the phase information unchanged, because the angle contains most of the images underlying characteristic information. The coefficients in equation 9, η and γ, can be utilized as additional enhancement parameters. By changing their values one can find other optimal enhancement points, though for simplicity these coefficients can usually be set to 1. Graphs showing how to use these coefficients along with the EME to locate optimal values can be shown in Figures 3d and 3e.(a)(b)(c)(d)(e)(f)Figure 3: (a) Original Pentagon image, (b) Pentagon image enhanced using LTHMHE with alpha-rooting, using k=0.78 (c) EME vs k, where k is a parameter of enhancement. Other examples of using plots of the EME to find optimal parameter values by picking themaximum: (d) Pentagon image enhanced using LTHMHE with η =1.2 and λ =3, (e) EME vs η vs λ, (f) EME vs γ vs λ.2.2 Choosing optimal parametersSince we have defined our measure of enhancement, it then becomes necessary to define the method of choosing optimal parameters based upon that measure. Utilizing the proposed measure of enhancement based upon entropy affords a simple mathematical basis for determining the optimal parameters of our enhancement.By plotting the EME versus the coefficients of the enhancement on a specific image we can return a descriptive graph as shown in Figure 3c. Interpreting this graph depends on the enhancement method. Since the method which we will be using for optimization involves alpha-rooting, we shall use the simple rule that the maximum EME value returns the optimal point. An example of an original image and its resulting optimized enhancement can also be found in Figure 3, as well as examples of choosing optimal parameter values using multiple parameters can be found in Figures 3d and 3e.2.4 Histogram equalization:Histogram equalization maps the input image’s intensity values to best approximate a uniform distribution. This technique is a useful tool for quick and easy image enhancement. In many cases, equalization successfully balances an image returning an increase in contrast.Given an image A(x,y) and a desired output image B(x,y) there is some transformation function, f, which maps A to B. All the pixels in A in the region a n to a a dn n + will have their values mapped to a corresponding region in B in the range of b n to b b dn n +. Each of these images will have a probability density function (PDF) )(A A n p and )(b b n p .Assuming a 1-1 mapping, it is easy to show thata a Ab b B dn n p dn n p )()(= (11)Using this relationship, it can be shown that the mapping function from A to B is)()()(0a A n A a n nF du u p n n f a==∫ (12)Where )(a A n F is the cumulative probability distribution function of the original image. Therefore, to return a histogram equalized image, an image must be transformed using its cumulative probability function.Histogram equalization's success at image enhancement is because it expands the dynamic range of intensity values while flattening the overall spatial histogram. This leads to a more overall even representation of all the spectrum of intensities, which can be used to bring out otherwise subtle details. This is usually a quick and effective method for image enhancement. On many images, histogram equalization provides satisfactory to good results, but there are a number of images where it fails to properly enhance the test image. The shortcomings and pitfalls of histogram equalization can be easily shown [6].As an example, Figure 4a shows an image of a helicopter. The resulting image after 256-level histogram equalization was applied is shown in Figure 4b. Figure 4c compares the spatial histograms of both images. Notice the loss of information on the body of the helicopter; you can no longer see the windows, or the details of the tail. The main focus of the image has become more of a silhouette than a picture. The background has been over emphasized as well. Other problems with histogram equalization can be artifacts and overall brightness change in the resulting image [6].(a) (b) (c)Figure 4: (a) Original Image of Copter , (b) resulting image after basic histogram equalization of Copter , (c) comparison of thespatial histograms before and after histogram equalization.2.5 Alpha-rooting:Alpha-rooting is a simple method that can be used in combination with many different orthogonal transforms such as the Fourier, Hartley, Haar wavelet and cosine transforms. The method is based upon two simple basic ideas: a) any signal, or image, is comprised of two elements, a magnitude and a phase; b) high frequency coefficients of an image, upon transformation, will have smaller magnitudes than low frequency coefficients. The first property can be shown in the equation below:),(),(),(s p j e s p X s p X θ= (13)It can be shown that the phase of an image contains most of the information needed to reconstruct the image, while the magnitude only contains the intensity of the point. This can be shown by combining the magnitude of one image with the phase of another, which will return almost a perfect reconstruction of the first image. It is then possible to change the magnitude information of an image without altering the basic layout of an image.The second concept behind this method is magnitude reduction. The main idea is that the magnitude of the lower frequency coefficients of a transform will have higher values than the higher frequency components. By raising the magnitude of an image to some value, α, where 0<α<1, the higher valued lower frequency components of an image can be reduced more in proportion to the lower valued high frequency components. This proportional reduction of magnitudes leads to an emphasizing of the high frequency content on an image. The mathematical form of this operation can be seen below. ),(1),(),(),(),(s p j e s p X s p X s p X s p X θαα==−) (14)where X(p,s) is the transform coefficients of the image x(p,s). Taking the inverse transform of the result returns the enhanced image. The resulting output shows an emphasis on the high frequency content of the image without changing the phase of the image results in an overall contrast enhancement of the entire image.3.METHODOLOGY3.1 Logarithmic transform histogram matching with histogram equalizationTraditionally, histogram matching is applied to spatial domain data, adjusting the range of values to match a specified histogram. In this paper, we discuss the application of transform histogram matching, which is a new take on the old concept.While investigating different qualities of images and their respective transform coefficient histograms, it had become apparent that the visually better images returned distinctly different transform histograms from their worse counterparts. This is the basis for our explorations of transform histograms and histogram equalization, a spatial technique that suffers from extreme dynamic range expansion, which can result in ugly artifacts, as previously shown. By combining this basic technique with transform enhancement methods, the end results can be surprisingly better in visual quality and quantitative measurement.Figure 5: Block Diagram of Logarithmic Transform Histogram Matching with Histogram EqualizationThe first proposed algorithm attempts to enhance the image using a histogram equalized image as a baseline. Logarithmic transform histogram matching with histogram equalization (LTHMHE) is detailed in Figure 5, and by the steps listed below:Input: Original ImageStep1: Transform Image (DCT, Fourier, and others)Step 2: Equalize the Histogram of the ImageStep 3: Take logarithm of magnitude coefficientsStep 4: Calculate coefficient histogramStep 5:Take logarithm of original transform dataStep 6: Map data to equalized histogramStep 7: Exponentiate dataStep 8: Restore phase and Inverse TransformOutput: Enhanced ImageThe first step would be to take an image and apply histogram equalization to it. This equalized image would then have its logarithmic transform histogram calculated as previously discussed. The original image would then have its logarithm transform coefficients mapped to create a similar histogram to match the equalized image’s transform histogram coefficients as shown in Figure 6b. The result of this enhancement leads to an overall flattening of the spatial histogram as shown in Figure 6a.(a) (b)Figure 6: (a) Comparison of spatial histograms of an original image, histogram equalization, and LTHMHE, (b) comparison oforiginal, histogram equalized, and LTHMHE3.2 Logarithmic transform histogram matching with histogram equalization with alpha-rootingBuilding off of the foundation of logarithmic transform histogram matching with histogram equalization, questions arose if we could improve the process by including already established methodologies into the algorithm. Alpha-rooting seemed a simple addition which could easily be inserted into our enhancement algorithm. The new algorithm takes the form of the flow graph shown below in Figure 7.The addition of alpha-rooting led to the ability to use the EME to pick an optimum enhancement value for the coefficient built into the alpha-rooting algorithm. This built in recursion allows for manipulation of enhancement variables to return desirable results. It should be noted that this is not the only place alpha-rooting could have been inserted to enhance the algorithm, but that this was the most obvious point.4.EXPERIMENTAL RESULTSTwo new methods were tested in this paper, proving to be formidable, powerful, and fast enhancement techniques. For the purposes of this paper, three images are shown. A table of results can be found in Table 1, and example images can be found in Figures 8, 9, and 10.(a) (b) (c)(d) (e) (f)Figure 8: (a) Original Image EME=0.01201, image enhanced using (b) histogram equalization EME=2.9321, (c) alpha-rooting EME=0.2856, (d) LTHMHE EME=9.9116, and (e) LTHMHE with alpha-rooting EME=40.2839. (f) Graph of EME versus α used tooptimize LTHMHE with alpha-rooting with peak at α=0.65.The first was an image of an Artic hare, chosen because of its strong concentration of data points around the intensity level of 255. This type of image, when enhanced, can have its dynamic range expanded to the point of changing the overall tone of the picture, along with creating ugly artifacts [6].The second image chosen was the Copter image. This image has the interesting characteristic of a relatively dark central area and a lighter, textured background. This image is usually difficult to enhance due to its unbalanced nature, leading most methods to either enhance the helicopter or the background but at the sacrifice of the other object.The third image chosen was the Plane image. This image is the direct opposite of the artic hare image, because it has data points concentrated around the lower end of the intensity spectrum. This image has hidden contour lines in the background along with prevalent film grain which cannot be seen in the original image.The first image’s overall tone is almost perfectly white, with very little variation, making it a hard image to enhance without altering the image drastically. The original EME had an extremely low value of 0.01201. After applying our logarithmic transform histogram matching with histogram equalization algorithm to the image we returned an EME of 9.9116, a huge increase in contrast. Compared to straight histogram equalization, which caused artifacts, tonal change to the image, and an EME of 2.392, LTHMHE enhanced the image better and avoided the undesirable side effects. Alpha-rooting performed admirably, raising the EME to 0.2856 by itself, although the image had the characteristic gray effect from the method. However, when we used the modified LTHMHE algorithm to include alpha-rooting we improved our resulting EME to 40.2839. Both the LTHMHE and the LTHMHE with alpha-rooting returned visually better results than alpha-rooting alone and histogram equalization. These results can be seen in Figure 8.(a) (b) (c)(f)(d) (e)Figure 9: (a) Original Image EME=0.03593, image enhanced using (b) histogram equalization EME=1.3027, (c) alpha-rooting EME=2.3506, (d) LTHMHE EME=9.015, and (e) LTHMHE with alpha-rooting EME=127.8699. (f) Graph of EME versus α used tooptimize LTHMHE with alpha-rooting with peak at α=0.04.The second image, the Copter, is a difficult image to enhance due to the tendency to enhance either the background or the helicopter but not both. The original image had an EME of 0.03593. Histogram equalization returned questionable results, with a complete loss of detail in the helicopter returning and EME of 1.3027. This is characteristic of the extreme dynamic range expansion problem which plagues histogram equalization. Our LTHMHE algorithm corrected this, returning visually pleasing results and an EME of 9.015. Alpha-rooting, alone, improved the image noticeably, returning an EME of 2.3506, again with the characteristic graying of the image. Inserting alpha-rooting into our LTHMHE algorithm returned the best results, conveying much more detail in both the helicopter and in the background. This exciting result returned an EME of 127.8699. Again, visually, the LTHMHE and LTHMHE with alpha-rooting returned better results that histogram equalization and alpha-rooting alone. These results can be seen in Figure 9.The third image, the Plane, is characteristically dark and dull. Our enhancement technique brought out the subtle details on the wings of the plane and in the background without overemphasizing any specific part of the image. The original image had an EME of 0.3340. Histogram equalization brought the EME of the image up to 23.3756, at the sacrifice of much of the image detail. This image shows the over-enhancement attribute of histogram equalization well, which caused a lot of the image to be lost in the grain and noise as well as the over emphasized subtle background ripples. After our process, LTHMHE, the enhanced image returned an EME of 33.8779, a staggering improvement. The image is visually clearer, more detailed, and generally better than the histogram equalized version. Alpha-rooting returned a slightly sharper image than the original returning an EME of 55.1932, while our LTHMHE with alpha-rooting returned an even higher EME of 138.578. As before, LTHMHE and LTHMHE with alpha-rooting returned results that were much more visually appealing that those found using histogram equalization and alpha-rooting. These results can be seen in Figure 10.(a) (b)(c)(c) (d) (e)Figure 10: (a) Original Image EME=0.33396, image enhanced using (b) histogram equalization EME=23.3756, (c) alpha-rooting EME=55.1932, (d) LTHMHE EME=33.8779, and (e) LTHMHE with alpha-rooting EME=138.578. (f) Graph of EME versus α usedto optimize LTHMHE with alpha-rooting with peak at α=0.08.Table 1: Comparison of resulting EME’s of different enhancement methods Original Histogram EqualizedAlpha rooting LTHMHELTHMHE with Alpha Rooting Artic Hare 0.012008 2.9321 α=0.80 0.2856 9.9116 α=0.65 40.2839 Copter 0.035928 1.3027 α=0.80 2.3506 9.015 α=0.04 127.8699 Moon 0.8681 6.6359 α=0.70 156.249 31.8327 α=0.56 91.8347 Pentagon 0.21835 41.5252 α=0.74 110.482 86.8147 α=0.78 331.0331 Plane 0.33396 23.3756 α=0.79 55.1932 33.8779 α=0.08 138.5785. CONCLUDING REMARKSThis paper proposed a new method of image enhancement based upon the logarithmic transform coefficient histogram using contrast entropy as a measure of performance and of optimization. Our results demonstrated the power of the logarithmic transform histogram matching with histogram equalization method, showing it to outperform classical histogram equalization. We also showed the modular nature of the proposed algorithm through the addition of alpha-rooting as a performance booster. As a benchmark, the performance of this algorithm was compared to established enhancement techniques: histogram equalization and alpha-rooting.A measure of enhancement is not a perfect science. There is not universal measure for image enhancement. In choosing a measure, it is necessary to choose those qualities in the image which are being measured. In our case we chose contrast. The measure was used to find optimal values as well as show image improvement numerically. After。

食品与饮水安全快速检测yingwen

Part 5 Fast inspection of food microorganism
5.1 Significance 5.2 Basic requirements for inspection 5.3 Sterile operation 5.4 Flow chart for microorganism inspection 5.5 Test and Result (test grid) 5.6 Test and Result (test kit) Part 6 Affiliated Equipments
1.4 On Spot Fast Inspection Methods
• 1. Color change of Test paper: limit control indicator eg. pesticide, rat poisoning chemicals…
• 2. Chromatography of Test paper: limit control indicator eg. sudan red, clenbuterol…
• Part 3 Fast Inspection for Illegal Food Additives and inferior food 3.1 Oil soluble inedible colorants 3.2 Water soluble inedible colorants 3.3 SO2(Sulfur Dioxide) 3.4 Boric acid and borax 3.5 Nitrate 3.6 formaldehyde in Rehydrated Aquatic products 3.7 Hydrogen Peroxide 3.8 Alkaline 3.9 Water-injected meat 3.10 Clenbuterol 3.11 Density of milk products 3.12 Urea content in milk products

2021-1997考研英语一七选五

A few premiers are suspicious of any federal-provincial deal-making. They (particularly Quebec
众 and Alberta) just want Ottawa to fork over additional billions with few, if any, strings attached. That’s 公 one reason why the idea of a national list hasn’t gone anywhere, while drug costskeep rising fast.
Co-ordinating Office for Health Technology Assessment, funded by Ottawa and the provinces. Under it, a Common Drug Review recommends to provincial lists which new drugs should be included. Predictably, and regrettably, Quebec refused to join.
研 Premiers love to quote Mr. Romanow’s report selectively, especially the parts about more federal
money. Perhaps they should read what he had to say about drugs: “A national drug agency would provide governments more influence on pharmaceutical companies in order to constrain the ever-increasing cost of drugs.”

英语演讲稿-17日：每周电视讲话：推行《平价医疗法》(中英lrc)

英语演讲稿17日：每周电视讲话：推行《平价医疗法》(中英lrc)Obama’s Weekly Address WEEKLY ADDRESS: Working to Implement the Affordable Care Act每周电视讲话：推行《平价医疗法》Hi, everybody. Over the past few weeks, I’ve been visiting with Americans across the country to talk about what we need to do to secure a better bargain for the middle class.大家好。

过去的几个星期，我去了全国很多地方，与人们谈论如何为中产阶级提供更好的保障。

We need to rebuild an economy that rewards hard work and responsibility; an economy built firmly on the cornerstones of middle-class life. Good jobs. A good education. A home of your own. A secure retirement. And quality, affordable health care that’s there when you need it.我们需要重建一个回报勤奋工作和敢于担当的经济体；一个为中产阶级提供坚实生活基础的经济体。

一份好的工作，一套良好的教育体系，一个属于你自己的住房，一份安宁的退休保障，一份大家所需的高质量的平价医疗保险。

Right now, we’re well on our way to fully implementing the Affordable Care Act. And in the next few months, we’ll reach a couple milestones with real meaning for millions of Americans.现在，我们正在全面实施《平价医疗法》的路上。

2023-2024学年人教版高中英语整理热点题型(含多套真题及答案)

2023-2024学年人教版全国高中英语同步练习学校：__________ 班级：__________ 姓名：__________ 考号：__________注意事项：1．答题前填写好自己的姓名、班级、考号等信息;2．请将答案正确填写在答题卡上;一、填空题（本大题共计5小题，每题3分，共计15分）1.These days，many of us use computers both at work and at home．We use them to do a number of different things，from typing documents to surfing the Internet and listening to music．However，it is important to remember that using a computer for long hours can cause harm to our bodies．Here are some tips to help keep you healthy when using a computer．Take care of your backMake sure your chair is the right height and size for you and the desk you use．Your desk should be at about the same level as your elbows when you are sitting down．Chairs with armrests are good because they allow you to rest your arms．Do not lean forward over the keyboard towards the screen because this is bad for your back．Sit upright，with your feet touching the ground and your back resting on the back of the chair．Doing these things will help you prevent back﹣related problems such as pain in your neck，shoulders and arms．Take care of your wrists and handsUsing a keyboard and a mouse can put pressure on your wrists and hands if it is not done properly．When you type，try to make sure your fingers are relaxed．You should hit the keys softly and hold the mouse gently．Mouse mats that come with soft material to support your wrist are really good too．Pain in the hands and wrists is very common among people who use computers a lot，so make sure you use your mouse and keyboard in the right way．Take care of your eyesYour eyes are very important and it is necessary to take care of them．You should give them regular breaks from staring at the computer screen．Every fifteen minutes，rest your eye muscles by looking away from the screen at something far away．Make sure that the top of your monitor is at eye level and that your monitor is about an arm's length away from you．Take a breakIt is important that you do not sit at a computer for too long．No matter how busy you are，try to take regular breaks from your desk．Stand up，go for a short walk or even do some stretching exercises．You should take a short break at least once an hour，and you shouldtry to do some stretching exercises every two hours．By following all these tips，you willnot feel so tired after using your computer for a long time．Title：Using computers and staying（71）________【答案】healthy, tips, harmful, suitable, with, Make, with, fifteen, once, exercises【解析】（71）答案：healthy，根据句子Here are some tips to help keep you healthy when using a computer可知短文主要是讲如何健康地使用电脑，因此stay后接形容词healthy"健康的"．（72）答案：harmful，根据句子However，it is important to remember that using a computer for long hours can cause harm to our bodies可知使用电脑太久对我们的身体是有害的，cause harm to＝be harmful to"对…有害"，故答案为harmful．（73）答案：tips，根据表格下面都是对如何健康使用电脑的建议，故使用名词tips．（74）答案：suitable，根据句子Make sure your chair is the right height and size for you and the desk you use可知要选择合适的椅子，因此使用形容词suitable．（75）答案：with，根据句子Sit upright，with your feet touching the ground and your back resting on the back of the chair．可知"坐直，脚碰到地面，背能靠在椅子后背"，故答案为with．（76）答案：Make，根据句子When you type，try to make sure your fingers are relaxed 可知打字时要让手指放松，根据下面两个句子也是祈使句，因此使用动词原形Make．（77）答案：with，根据句子Mouse mats that come with soft material to support your wrist are really good too可知由柔软材料的鼠标来支撑手腕是好的，因此表示"带有"用介词with，故答案为with．（78）答案：fifteen，根据句子Every fifteen minutes，rest your eye muscles by looking away from the screen at something far away可知每隔十五分钟眼睛就要休息．（79）答案：once，根据句子You should take a short break at least once an hour可知答案为once．（80）答案：exercises，根据句子and you should try to do some stretching exercises every two hours可知答案为exercises．2.What Does Teamwork Really Mean？We often hear the word "teamwork"． But are you a team player？ Understanding the question can surely promote team spirit as well as individual development． In many job interviews， a common question is whether the interviewee is a "team player"． Moreoften than not， he or she will say "yes"． But what does being a team player really mean？On the most basic level， a team player is someone who can work within a group of people． This group is a number of people greater than one． Therefore it is an essential requirement of any employment that any potential employee is a team player．On a deeper level， a team player is someone who can play a role in the team， to achieve and support the goals set and agreed upon by the team． The simplest analogy（类似）to the corporate team would be a sports team．There are two main aims of the football team． One is to score goals and the other is to prevent the opposition team from scoring． In football， there are eleven players per side，and almost the same number of players in reserve． There are also other vital members of the team in the background， such as the coach， the doctor， etc．Every member of the team has a very specific role ﹣ as a captain， goalkeeper． Every member of the team is vital to the success of the team． If one player does not perform to the best of his or her ability， the team is handicapped（阻碍，妨碍）．Similarly in the corporate world， each company has its clearly defined goals． Every member of the corporate team should have specific roles and responsibilities in view of achieving these goals．Being a team player does not mean you should always agree with the rest of theteam． There are times when your vision may differ from the vision of the company， the leader or the rest of the team． It may be a valid vision and if you believe in it strongly enough， you should share it with the rest of the team． If the leader is a competent one，he or she will assess it on its merits and not let ego（自我，自负） get in theway． However， if the team should not agree with your vision， don't take it personally．They may find the idea inappropriate， not YOU personally． Don't take it as a sign of personal rejection． If your leader or team members see that you can handle rejection of your ideas in a mature manner， it is only to your own credit．So， don't be afraid to offer new ideas even seemingly crazy ones． Everyone in the team should feel free to offer ideas and not worry about them being dismissed．The pleasure of working in an environment where every member of the team is a team player is unparalleled． If you are not enjoying your working environment， chances are high that your team is also not working well． Ask yourself this：Are your team objectives in line with those of the company？ If not， why not？What Does Teamwork Really Mean？【答案】usually, basically, Analogy, important, take, Suggestions/Advice, disagree, maturely, bravely, likely【解析】（1）usually；考查副词．根据第一段中的"a common question is whether the interviewee is a "team player"． More often than not， he or she will say "yes"．"可知，一个常见的问题是受访者是否具有团队精神，通常情况下，他或她会说"有"，故填usually．（2）basically；考查副词．根据第二段中的"On the most basic level， a team player is someone who can work within a group of people．"可知，从基本层面上来讲，团队成员是能够在一群人当中工作的人，故填basically．（3）Analogy；考查名词．根据第三段中的"The simplest analogy（类似）to the corporate team would be a sports team．"可知，与企业团队最简单的类比就是体育团队，故填Analogy．（4）important；考查形容词．根据第五段中的"Every member of the team is vital to the success of the team．"可知，团队里的每个成员对团队的成功都是至关重要的，play an important role in固定短语，"在……中扮演重要角色（发挥重要作用）"，故填important．（5）take；考查动词．根据第六段中的"Every member of the corporate team shouldhave specific roles and responsibilities in view of achieving these goals．"可知，为了实现目标，团队中的每个成员都有特定的角色和职责，take one's responsibility for固定短语，"对……负责"，故填take．（6）Suggestions/Advice；考查名词．根据第七段中的"Being a team player does not mean you should always agree with the rest of the team．"可知，作为团队成员并不意味着你总是要同意团队里其他成员，接下来就介绍了如何成为团队成员的几点建议，故填Suggestions/Advice．（7）disagree；考查动词．根据第七段中的"There are times when your vision may differ from the vision of the company， the leader or the rest of the team． It may be a valid vision and if you believe in it strongly enough"可知，有时你的想法可能与公司领导和其他人的想法不同，如果你足够相信，它可能是一个有效的想法，也就是说当你的想法与别人的想法不一致时，你应该坚持自己的想法，disagree with固定短语，"与……不一致"，故填disagree．（8）maturely；考查副词．根据第八段中的"They may find the idea inappropriate， not YOU personally． Don't take it as a sign of personal rejection． If your leader or team members see that you can handle rejection of your ideas in a mature manner，"可知，当别人认为你的想法不合适时，不要认为是对你的个人拒绝，要成熟地处理它，故填maturely．（9）bravely；考查副词．根据第九段中的"So， don't be afraid to offer new ideas even seemingly crazy ones．"可知，不要害怕提出你的新想法，即使它看起来很疯狂，也就是说要勇敢地提出自己的想法，故填bravely．（10）likely；考查形容词．根据倒数第二段中的"If you are not enjoying your working environment， chances are high that your team is also not working well．可知，如果你对工作氛围不满意，很可能是你的团队没有很好地工作，be likely that固定短语"很有可能……"，故填likely．3.Learning how to be patient with others can be challenging for some people．After all，not everybody is gifted with great patience．The good news is that it is something that can be learned and eventually perfected．When the customer before you takes ages to pay for his or her groceries，you tap your foot impatiently and cough every now and then to remind the customer to mov e quickly；but no，he is still not hurrying up．It takes all of your power not to make a scene．However，if you imagine that customer to be someone you like，then you will find yourself not getting too annoyed，right？So the next time you find yourself losing patience with somebody，simply think of that person to be someone you really adore and you r patience will last longe r．The second step on how to be patient with people involves whistling．When you whistle a h appy tune，you are instantly in good spirits．You can hum（哼唱）your favorite song if you can't whistle-it really doesn't make a difference．What's important here is that you did something that m akes you feel good．And when you feel good，you are more likely to be patient with the people around you．When you're stressed，it's almost impossible to learn how to be patient with people．You've got to find a way to rel ax first．If you know you're going to be in a Situation where your patience will be tested，get yourself a massage（按摩）first．Remember：the more stressed you are，the faster you'll lose you r temper．However，learning how to be patient with people is not a must in life．You've seen people who manag e to survive day to day with unbelievably short tempers after all，56．What's the main idea of the passage？（No more than l0words）________ 57．What does the underlined expression"make a scene"in Paragraph 2mean？（No more than 3words）________58．Why does the author think humming or whistling can help you get patient？（No more than l5words）________59．What does the author advise you to do when you are getting stressed？（No more than 10words）________60．Do you think learning how to be patient with people is a must in life？Why？（No more than 20words）________．【答案】Waysoflearningtobepatient．/Howtobepatientwithothers．, Loseyourtemper．/Quarrelwithothers．/Getimpatient．/Getangry．, Becauseitcanhelpyoufeelgoodandgetpatient, Tofindawaytorelaxfirst, "No，Idontthinkso．Becauseweveseenpeoplewhomanagetosurvivedaytodaywithunbelievablyshor ttempers．"【解析】56．Ways of learning to be patient．/How to be patient with others．根据开头一句Learning how to be patient with others can be challenging for some people．本文论述的一个核心话题是如何耐心地与人相处，所以标题可总结为Ways of learning to be patient．/How to be patient with others．57．Lose your temper．/Quarrel with others．/Get impatient．/Get angry．前面提到了你的一位顾客赖账，经提醒仍然不自觉还款，你努力控制的是不发脾气，结合后面的then you will find yourself not getting too annoyed，right一句由此推出make a scene的意思是Lose your temper．/Quarrel with others．/Get impatient．/Get angry．58．Because it canhelp you feel good and get patient根据第三段What's important here is that you did something that makes you feel good．可知，你吹口哨或者哼唱歌曲的目的是使你处于良好的情绪中，这样就会使你更有耐心，所以答案可总结为Because it canhelp you feel good and get patient．59．To find a way to relax first根据第四段前两句When you're stressed，it's almost impossible to learn how to be patient with people．You've got to find a way to rel ax first．可知，当你感到压抑的时候，你要试图找个方法放松自己；故答案为To find a way to relax first．60．No，I don't think so．Because we've seen people who manage to survive day to day with unbelie vably short tempers．本题可由考生自由发挥，只要针对本文话题言之有理，符合答题格式即可，要首先回答是否认可这种观点，然后给出理由．4.Hurricane Katrina slammed into the Gulf Coast on August 29， causing massive damage to New Orleans and along the coasts of Mississippi and Alabama， as well as other parts of Louisiana． The storm brought winds of 145 miles per hour， which cut power lines and destroyed homes， even blowing cars into things． Katrina caused record storm waves all along the Mississippi Gulf Coast， which overwhelmed the levees（堤坝） that protected New Orleans， located at six feet below sea level． ________The federal government and President George W． Bush __________for what people thought was a slow response to the disaster． The head of the Federal Emergency Management Agency （FEMA） resigned amid（在…中） the fighting afterwards． Katrina was just one of four major hurricanes to hit the U．S． during the 2005 hurricane season，which was described as "highly unusual" by meteorologists． The season， which ranseveral days past its official November 30 end date， set new records for most hurricanes （13）， most hurricanes over Category 3 （7）and most named storms （26）． Many scientists believed that global warming was responsible for the development of the more powerful storms．（1）What is the best title of this passage？（Please answer within 10 words）________ （2）Which word in this passage has the following meaning？________to put， push， knock or strike something with great force or violently．（3）Please fill in the blank in the second paragraph with proper words or phrases to complete the sentence．（Please answer within 10 words．）________（4）Imagine you are one of the lucky survivors of the hurricane in New Orleans， please describe the disaster in less than 30 words．________（5）Please translate the underlined sentence into Chinese．________【答案】Eightypercentofthecitywasfloodeduptotherooftopsofmanyhomesandsmallbuildings，andanestimated1，300peoplediedbecauseofthestorm，whichisbelievedtohavecausedupto﹩150billionindamages, Hurricane Katrina Hit the U．S, slam, were roundly criticized, HurricaneKatrinacausedmassivedamagetotheUSThewindsbroughtbythestormcutpowerlinesa nddestroyedhomesAbout1，300peoplediedbecauseofthestorm, 城市80%的地方洪水淹没了住宅和小建筑物的房顶，据估计1，300人死于这次暴雨中，损失达到一千五百亿．【解析】1． Hurricane Katrina Hit the U．S．主旨大意题．根据文章第一句Hurricane Katrina slammed into the Gulf Coast on August 29， causing massive damage to New Orleans and along the coasts of Mississippi and Alabama， as well as other parts of Louisiana可知8月29日飓风卡特里娜袭击了墨西哥湾海岸，在新奥尔良、密西西比州和路易斯安那州海岸以及亚拉巴马州的一些地区造成巨大的破坏，故答案为Hurricane Katrina Hit the U．S．2． slam．词义猜测题． to put， push， knock or strike something with great force or violently意思是用力或猛烈地放、推、敲或打某物，与文章的slam（猛烈袭击）同义，故答案为slam．3． were roundly criticized 推理判断题．根据下文for what people thought was a slow response to the disaster可知联邦政府和布什总统因人们认为对灾难反应迟缓而受到严厉批评，故答案为were roundly criticized．4． Hurricane Katrina caused massive damage to the U．S． The winds brought by the storm cut power lines and destroyed homes． About 1，300 people died because of the storm．开放题．卡特里娜飓风给美国造成了巨大的破坏，风暴带来的风切断了电线，摧毁了房屋．大约1300人死于风暴．5．城市80%的地方洪水淹没了住宅和小建筑物的房顶，据估计1，300人死于这次暴雨中，损失达到一千五百亿．翻译题．注意be flooded 意为"被淹没"； because of 意为"由于"；up to意为"高达……"．5.Louis Sachar is considered among the greatest modern writers in children's literature，famous for books such as Holes and the wayside school series.Louis was born on March 20，1954 in East Meadow，New York. His father was a salesman. Louis had a close relationship with his elder brother Andy， who was considered to have the greatest influence on his life. When he was 9， his family moved to Tustin， California where Louis attended the Red Hill School in which he studied well and truly realized his love for.After graduating， Louis attended Antioch College. However， due to the death of his fatherhe returned to California and went to the University of California where Louis developed interest in children while working as a teacher's aide（助手）.In 1976，he worked in a sweater warehouse in Norwalk during the day and wrote his first book at night. Later his book Sideways Stories from Wayside School was accepted for publication. As the book didn't sell well at first， Louis did a part﹣time job to support himself. From 1989， his books have been selling well enough to allow him to start writingfull﹣time.In 1998， his young adult mystery comedy novel titled Holes was published. It won many awards. As of 2015， Louis Scalar had written 25 books for children and young adults. According to Louis's wife， the reason behind the popularity of his works is his ability to tell stories from a kid's point of view. Another reason is that he knows the intelligence of his young.（1）When did Louis start to show interest in children？（No more than 10 words）________（2）What do we know about Sideways Stories from Wayside School upon being published？（No more than 5 words）________（3）Why was his works popular？（No more than 20 words）________（4）What's the text mainly about？（No more than 8 words）________（5）Who is your favourite writer？ Why do you like him or her？（No more than 25 words）________【答案】"WorkingasateachersaideintheUniversityofCalifornia.", "The book didnt sell well.", "Becausehecantellstoriesfromakidspointofviewandknowtheintelligenceoftheyoung.", "（Its mainly about）Louiss experience，works and achievement.", I like Louis most for his works，especially his novel titled Holes，which show readers good will be rewarded with good，evil with evil./My favourite writer is Louis because his works attract me deeply.【解析】（1）Working as a teacher's aide in the University of California.细节理解题。

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PACS numbers: 05.50.+q, 02.10.De, 02.70.-c, 11.25.Hf
arXiv:cond-mat/0601568v1 [cond-mat.stat-mech] 25 Jan 2006
The monomer-dimer problem is a classical model in statistical physics. In the model the diatomic molecules are modeled as rigid dimers which occupies two adjacent sites in a regular lattice and no lattice site is covered by more than one dimer. The lattice sites that are not covered by the dimers are regarded as occupied by monomers. A central problem of the model is to enumerate the dimer conﬁgurations on the lattice. A breakthrough came in 1961 when an elegant exact closed-form solution was found for a special case of the model in plane lattices, namely when the lattice is completely covered by dimers (the close-packed dimer problem, or dimercovering problem) [1]. The method used to achieve this solution, however, cannot be extended to tackle the more general monomer-dimer problem where there are vacancies in the lattice, and the problem remains unsolved notwithstanding years of eﬀorts. Rigorous results exists only for series expansion in low dimer density [2], lower bounds on free energy [3], monomer-monomer correlation function of two monomers in a lattice otherwise packed with dimers [4], and locations of zeros of partition functions [5]. Some approximate methods have been proposed [6]. One recent advance is an analytic solution to the special case of the problem where there is a single vacancy at certain speciﬁc sites on the boundary of the lattice [7]. There is renewed interest in monomer-dimer problem recently. The interest comes from diﬀerent directions. Besides the intrinsic interest of the problem itself and its close relation to the well-studied Ising model [8], the model also acts as the classical limit of the recently introduced quantum dimer model [9], which has been investigated intensively as the central model in modern theories of strongly correlated quantum matter. The problem also attracts attention in the ﬁeld of
computational complexity. It has been shown that twodimensional monomer-dimer problem is computationally intractable and belongs to the “#P-complete” class [10]. #P-complete class plays the same role for counting problems (such as counting dimer conﬁgurations discussed here) as the more familiar NP-complete class for the decision problems (such as the well-known traveling salesman problem). The #P-complete problems are at least as hard as the NP-complete problems [11]. If any problem in the #P-complete class is found to be solvable, every problem in #P class is solvable. Currently it is not clear whether there exists any such solution to the #Pcomplete or NP-complete class problems, and “P verse NP” problem is the perhaps the major outstanding problem in theoretical computer science. In this Letter we report the logarithmic correction in the free energy of the monomer-dimer model with arbitrary number of monomers on plane lattice strips of size m × n, where the width n is ﬁxed, and address the ﬁnding in the context of universality, scaling, and exact ﬁnitesize corrections in critical systems. These topics have been studied intensively in recent decades. As one of the few non-trivial exactly solved statistical lattice models, the dimer model attracts much attention recently to test the predictions of conformal ﬁeld theory [12] and ﬁnitesize scaling [13]. Unlike other models, the (close-packed) dimer model on plane lattice shows certain peculiarity with respect to the predictions of the theories, both for the central charge [14, 15] and for the logarithmic corrections [14]. The free energy of a two-dimensional system at criticality is assumed to have the form of [12, 13] Fm,n = mnfb + (m + n)fs + C ln m + D + o(1). (1)
∗ Electronic
address: matky@.sg
The ﬁrst two terms, fb and fs , are the “bulk” and “surface” terms, respectively. These two terms are not universal and depend on the details of the model. The other two coeﬃcients, C and D, are supposed to be universal, depending only on the shape of the system and the boundary conditions. The dimensionless coeﬃcient D is
Logarithmic corrections in the free energy of monomer-dimer model on plane lattices with free bo Mathematics National University of Singapore Singapore 117543 (Dated: February 6, 2008) Using exact computations we study the classical hard-core monomer-dimer models on m × n plane lattice strips with free boundaries. For an arbitrary number v of monomers (or vacancies), we found a logarithmic correction term in the ﬁnite-size correction of the free energy. The coeﬃcient of the logarithmic correction term depends on the number of monomers present (v ) and the parity of the width n of the lattice strip: the coeﬃcient equals to v when n is odd, and v/2 when n is even. The results are generalizations of the previous results for a single monomer in an otherwise fully packed lattice of dimers.