A new MRI grading system for__chondromalacia patellae

合集下载

高三英语阅读理解填空单选题40题

高三英语阅读理解填空单选题40题1. The application of artificial intelligence in the medical field has brought great convenience. For example, AI can ______ medical images to detect diseases at an early stage.A. analyzeB. createC. ignoreD. distort答案：A。

解析：根据文章内容，人工智能在医疗领域能检测早期疾病，所以应该是分析医疗图像，A选项analyze分析符合题意。

B选项create创造，人工智能不是创造医疗图像来检测疾病，不符合语境。

C选项ignore忽视，与检测疾病相悖。

D选项distort扭曲，也不符合人工智能在医疗图像检测疾病方面的功能。

2. AI - powered robots in the medical field can assist surgeons during operations. They can ______ the surgeons' movements with high precision.A. imitateB. preventC. replaceD. delay答案：A。

解析：文章提到人工智能机器人能在手术中辅助外科医生，能高精度地模仿外科医生的动作才是辅助的体现。

B选项prevent阻止，与辅助相悖。

C选项replace取代，这里说的是辅助而不是取代。

D选项delay延迟，不符合辅助外科医生这一情境。

3. In medical diagnosis, AI systems can ______ a large amount of patient data quickly to provide accurate diagnosis suggestions.A. storeB. processC. deleteD. lose答案：B。

第三版新视野课后练习Book1-3 TextA

4.Add -ry, -ive, or –ize to or remove them from the following
words to form new words.
Words learned
New words formed
-ry
scene Machine
scenery machinery
-ive
quick (2)_____H_to its rich educational resources.
Now the Internet has been accepted as the (3)___L___technology to many other methods in colleges and universities. Many teachers now routinely (4)__N__ their teaching materials online.
5. Some of your suggestions have been _a_d_o_p_t_ed_, but others have been turned down as they are not workable.
Words in use
response transform focus analyze estimate competitive compensate adopt typical regulate
Word building 5. Fill in each of the blanks with the newly-formed words in Activity 4. Change tje form where necessary. Each word can be used only once.

高三英语信息技术单选题50题

高三英语信息技术单选题50题6.She often _____ documents in the office software.A.editsB.makesC.createsD.designs答案：A。

本题考查动词在信息技术语境中的运用。

“edit”有“编辑”之意，在办公室软件中经常是编辑文档，符合语境。

“makes”通常指制作，范围比较宽泛，不如“edits”具体；“creates”强调创造新的东西，编辑文档不是创造新文档；“designs”主要是设计，与编辑文档的语境不符。

7.He _____ a new folder to store his files.A.buildsB.makesC.createsD.forms答案：C。

“create”有创建之意，创建新文件夹用“creates”比较合适。

“builds”通常用于建造较大的实体物体；“makes”制作的对象比较宽泛，不如“creates”准确；“forms”主要指形成某种形状或结构，不太适合创建文件夹的语境。

8.She _____ a file by mistake and had to restore it.A.deletedB.removedC.lostD.discarded答案：A。

“delete”表示删除，不小心删除了文件符合语境。

“removed”通常指移除某个物体，不一定是删除文件；“lost”是丢失，不一定是主动删除导致的；“discarded”侧重于丢弃不要的东西，不如“deleted”准确。

9.He _____ the file to another location.A.movedB.shiftedC.transferredD.carried答案：C。

“transfer”有转移、传送之意，把文件转移到另一个位置用“transferred”比较恰当。

“moved”和“shifted”比较笼统，没有“transfer”在信息技术语境中那么准确；“carried”通常指携带，不太适合文件转移的语境。

A secure data hiding scheme for two-color images

A Secure Data Hiding Scheme for Two-Color ImagesYu-Yuan Chen,Hsiang-Kuang Pan,and Yu-Chee TsengDepartment of Computer Science and Information EngineeringNational Central UniversityChung-Li,32054,TaiwanEmail:yctseng@.tw(corresponding author)AbstractIn this paper,we propose a new steganography scheme forhiding a piece of critical information in a host binary image(such as facsimiles).A secret key and a weight matrix are usedto protect the hidden data.Given an image block of size,our scheme can hide as many as bits of datain the image by changing at most2bits in the image.Thisscheme,as compared to an existing scheme[18],can providehigher security,embed more data,and maintain higher qualityof the host image.1IntroductionAs digital media are getting wider popularity,theirsecurity-related issues are becoming a greater concern.Onecentral issue is conﬁdentiality,which is typically achieved byencryption.However,as an encrypted message usuallyﬂagsthe importance of the message,it also attracts cryptanalysts’interests.The sometimes confusing terminology stagenogra-phy has a differentﬂavor from encryption;its purpose is toembed a piece of critical information in a non-critical hostmessage(e.g.,webpages,advertisements,etc.)to distractopponents’attention[7,12].One less confusing name forsteganography would be data hiding.It should be understoodthat steganography is orthogonal to encryption,and it may becombined with encryption to achieve a higher level of security.The study of this subject may be traced to[9],where thePrisoners’Problem was proposed.In this scenario,Alice andBob are in jail,and wish to hatch an escape plan.All theircommunications must go through the warden,Willie,and ifWillie detects any encrypted messages,he will frustrate theirplan by throwing them into solitary conﬁnement.So theymustﬁnd some way to hide their plaintext(or ciphertext)inan innocuous-looking covertext.The history and bandwidthconcerns of the subliminarl channel are discussed in[11,10].A nice clariﬁcation on steganography is in[2].Data hiding is usually achieved by alternating somenonessential information in the host message.Given a colorimage,one simple approach is to use the least-signiﬁcant bitsented in Section3.Analysis and experimental results are in Section4.Section5draws our conclusions.2Reviews and MotivationsBelow,we review the data hiding scheme proposed by[18], through which we will identify problems and motivate our work.Weﬁrst deﬁne some notations.We treat a bitmap as an integer matrix,and thus the terms“bitmap”and“matrix”will be used interchangeably.Given two bitmaps andof the same size,we denote by the bitwise AND of these two bitmaps.Similarly,we denote by the bit-wise exclusive-OR of and.Given an integer matrix, we denote by the element of at row and column, and by the sum of all elements in.The data hiding scheme of[18]works as follows.We are given a host binary image,a secret key,and some critical data bits to be embedded in.The secret key is a bitmap of size.For simplicity,it is assumed that the size of is a multiple of.In the embedding is achieved by modifying some bits of.S1.Partition into blocks,each of size.S2.For each block obtained in step S1,check whether the condition“”holds true.If so,go to step S3to embed one data bit in;otherwise,no data will be embedded in and will be kept intact.S3.Let the bit to be embedded in be.Then do the fol-lowing to modify:if()thenKeep intact;else if()thenRandomly pick a bit such thatand change to1;else if()thenRandomly pick a bit such thatand change to0;elseRandomly pick a bit such thatand complement;end if;In summary,the above scheme tries to embed as many as one data bit in each block.A block can hide one data bit if(the reason will become clear later).Suppose is changed to.The scheme maintains the following invariant:I1.It is not hard to verify that step S3guarantees this invariant. Thus,when the receiverﬁnds thatFig.1.An example of hiding3bits in abitmap.,he/she can derive the embedded data bit by com-puting.As an opponent does not know the secret key,the embedded data is secure.At most one bit in will be modiﬁed if some data is embedded.So the outlook of will not be changed signiﬁcantly if block size is large enough.Consider the example in Fig.1,where is a bitmap and is a bitmap.First,is partitioned into four blocks and.Since, no data is embedded in.Since,one data bit can be embedded.As theﬁrst bit to be embedded is 0,is changed to to preserve the above invariant(the changed bit is marked by gray).For,sincebut the next embedded bit is1,is kept intact. Similarly,is modiﬁed to hide a data bit of1.Below,we discuss some properties and weaknesses of this scheme.First,since the binary AND operator is used to com-pute,the maximal value of can not exceed.Second,by the nature of binary AND,if a block has to be modiﬁed,it must occur in the locations in which the secret has a value of1.Thus,when a completely blank is transmitted(or a large part of is so),an opponent can easily notice the modiﬁed locations and thus derive the secret key.This is why the scheme excludes out the possi-bility of using an such that to hide data. For a similar reason,the case ofis excluded out from embedding data to prevent the attack of being completely black or a large part of being so(for instance,when is completely black,any modiﬁcation on its bit will imply that the corresponding bit in is1).However, even with these constraints,the value of may still be com-promised.A pixel location that has ever been changed must imply a1in corresponding location in;a pixel location that is never changed may imply a0in the corresponding location in.Also,must be chosen with a lot of care.A with too few1’s will suffer from low data hiding rate and may be easily compromised.A with too many1’s will suffer from a brute-force attack.Similarly,the host bitmap should be chosen with care.An with too many0’s is not a good host image because the data hiding rate may be low.3A Secure Data Hiding Scheme for2-Color ImagesIn this section,we propose a new data hiding scheme that can greatly improve over[18].The basic ideas are:(i)to useFig.2.Block diagram of the proposed data hid-ing scheme.a different binary operator XOR to protect the secret key from being compromised,and(ii)to use a weight matrix to increase the data hiding rate while maintaining high quality of the host image.The block diagram of our scheme is depicted in Fig.2.The inputs to our scheme are::a host bitmap,which is to be modiﬁed to embed data.(We will partition into blocks of size.For simplicity,we assume that the size of is a multiple of .):a secret key shared by the sender and the receiver.It is a randomly selected bitmap of size.:a secret weight matrix shared by the sender and the receiver.It is an integer matrix of size whose content satisﬁes some requirements(to be stated later).:the number of bits to be embedded in each block of.The value of satisﬁes.:some critical information consisting of bits to be embedded in,where is the number of blocks in.3.1Weight ManagementOur scheme heavily relies on the weight matrix to rep-resent the embedded data.This section shows how this works through an example.The complete scheme will be presented in the next section.Suppose the size of and is.Below,we consider a block of the host image.We will show how to embed bits of data in.Let’s assume the following inputs:First,we will perform a bitwise exclusive-OR on and:Next,let be the pairwise multiplication operator on two equal-size integer matrices.We compute:Summing all elements in above result,we have.Next,we will embed two data bits,say,into.Sup-pose that is changed to.Regarding as a binary number,our scheme will ensure the following invariant:I2.,With this invariant,the receiver can derive by computing.Note that there are two ma-jor differences when comparing I2to I1.First,the modular equation is generalized for embedding two bits.Second,there is a precondition on the value of in I1,whereas there is no such a precondition in I2,implying that any block can carry two bits of hidden data.Next,we show how to modify to ensure I2.We intend to change as few bits in as possible.Since,if fortunately,then there is no need to modify.Otherwise,some bit(s)has to be modiﬁed.Ob-serve that if we complement bit,then will be complemented.If is swapped from0to1,then the modular sum will be increased by;otherwise,the sum will be decreased by.For instances,if we swap, the sum will be decreased by,and if we swap, the sum will be increased by.It is not hard to verify that we need to complement only one bit in to increase or decrease the sum by1,2,or3in this example.3.2The Hiding StepsDeﬁnition1An matrix can serve as a weight matrix if each element of appears at least once in ,i.e.,.The rationale of this deﬁnition will become clear later. Note that it is trivialﬁnd a legal because at the very be-ginning we have imposed that.Also,there are many choices for.We canﬁrst pick elements in and assign to them.The remainingelements can be assigned randomly.Thus,the number of choices for is:For instance,if and,there arepossible’s.This number should be large enough to forbid a brute-force attack.Let be a legal weight matrix and be a block of. Below,we show how to embed bits of data,say, into by changing at most2bits in.Our goal is to modify into to ensure the following invariant:I3:.Below,we derive the embedding scheme in4steps.pute.pute.S3.From the matrix,compute for eachthe following set:Intuitively,is the set containing every matrix indexsuch that if we complement,we can increase the sum in step S2by.There are actually two possibilities to achieve this:(i)if and,then complementing will increase the weight by,and(ii) if and,then complement-ing will decrease the weight by,or equivalently increase the sum by(under).The following lemmas reveal some important properties of these sets.Lemma1For each such that,the following statement is true:Proof.Suppose that.By Deﬁnition1,there is at least one element.It must be that;otherwise,complementing will increase the sum by ,making nonempty.If we complement,the sum will be decreased by,or equivalently increased by.So,the set is nonempty.Note that this is with the exception that,in which case.Lemma2The set.Proof.By Deﬁnition1,there is at least one element .Since,no matteris0or1,if we complement,the sum will be increased/decreased by,hence proving this lemma.S4.Deﬁne a weight differenceWe have to increase the sum in step S2by to satisfy I3.If,there is no need to change.Otherwise, we run the following program to transform to.For ease of presentation,let’s deﬁne for any.a)Randomly pick an such thatand.b)Randomly pick a and complement thebit;c)Randomly pick a and comple-ment the bit;Intuitively,to increase the sum by,we can pick two nonempty sets and.Since these sets indicate thelocations where we can complement to increase the weightby and,respectively.The overall effect is an increase of the weight by.However,there are logicalﬂawsin the above program,which we left intentionally for ease of presentation.First,the set(and similarly,,, etc.)is not yet deﬁned.Like other’s,we can regardas the set of indices such that complementing these locations in will result in an increase of weight by.Since this can be achieved by doing nothing on,we can always regard as nonempty and whenever the statement“complement the bit ”is encountered,we simply skip this step.This amend-ment will make the program complete.The next problem is to prove that in step a,we can alwaysﬁnd a qualiﬁed,which is shown below.Lemma3Step S4will always succeed,and at most two bitsof will be modiﬁed to embed bits of data.Proof.We test a series of values for and show that eventu-ally a qualiﬁed can be found.First,we test.If, then is a solution.Otherwise,,which im-plies by Lemma1.Then,we test.If, then is a solution.Otherwise,,which im-plies by Lemma1.Next,we test.If, then is a solution.Otherwise,,which implies .We can repeat this process to test,,etc.If the tests keep on failing,we claim that eventually will be tested.If so,Lemma2guarantees that is nonempty and thus we are done.The claim can be proved by a simple rule in num-ber theory,which says thatmust contain all and only the numbers that are a mul-tiple of under[5].As is a multiple of ,will eventually be tested.Finally,it is easy to see that at most2bits of will bemodiﬁed.Below,we demonstrate an example.Let the host image ,secret key,and weight matrix be as shown in Fig.3. First,is partitioned into four blocks.Let, so we can embed12bits,say into.The exclusive-OR result of each block and is inFig.4(a).For,.Since the embedded data is,we have to increase the weight by .Since and,we can comple-ment.For,.Since the embedded data is,there is no need to modify.For,.Since the embedded data is, we have to increase the weight by,which can be done by complementing.For,. Since the embedded data is,we have to increase the weight by5.There is no single point in by comple-menting which we can do so.So changing two bits ofFig.3.An example of host image ,secret key,and weight matrix.Fig.4.(a),and (b)the modiﬁed host im-age.is necessary.One possibility isand.In this example,we choose to complement and .The ﬁnal mod-iﬁed image is shown in Fig.4(b).4Vulnerability Analysis and Experimental Re-sults4.1Possible Attacks and CostsIn the following discussion,we assume that an opponent already knows the data hiding algorithm,the host image ,the value of ,and the block size.Also,the opponent captures a copy of the modiﬁed image .A brute-force attackis quite impossible,since there areand combinations for and ,respectively.Next,we consider a chosen-plaintext attack,which uses a differential technique to reduce the search range of .Sup-pose part of is available to the opponent.If the opponentcan ﬁnd a block which is translated toafter embedding bits ,and a block which is translated to after embed-ding bits ,then the attack may proceed in several ways.If,then the difference of and will somehow re-ﬂect the relation of weights in the locations where differsfrom and where differs from .If we further assumethatand that there is only one location,say ,in being changed,then the value of must be or ().If each entry of can be so compro-mised,then the possible combinations of can e reduced to about .If unfortunately the weight matrix has been compro-mised,then the keycan be compromised easier.For in-stance,if anddiffer from at only onelocation,say,then can be derived as follows.If,then ,imply-ing that .On the contrary,if,then ,implying thatis the complement of .The attack will succeed if each entry of can be so compromised.As can be seen,the above attack has a very high cost,as long as the block size ()is reasonably large and the secrecy of and is maintained.4.2Experimental ResultsTo visualize the data hiding effect,we have implementedthe WL scheme [18]and our scheme.Below,we present our experimental results on the two host images in Fig.5(a),and Fig.6(a).We make comparison from three aspects:A)Equal Block Size:We use the same block size and com-pare images’quality after data hiding.The results are in parts(b)and (c)of Fig.5,and Fig.6,where the block size is.Our results have more “noises”since as many as 2bits in each block will be modiﬁed compared to 1bit of the WL’s.In this case,we trade image quality for higher data hiding ratio.In general,our scheme can hide about 4to 10times more data than that of WL’s.B)Equal Image Quality:In this experiment,we try to equalize the image quality by adjusting the block size.It is easy to see that the WL scheme will modify in average 0.5bit in each block hidden with data.To maintain the same image quality,we can use a block size that is 4times larger than that in WL scheme.Thus,in the worst case,2bits will be modiﬁed in each of our blocks,or equivalently 2/4=0.5bit in each of WL’s blocks.Based on this assumption,we show the experi-mental results in parts (d)and (e)of Fig.5,and Fig.6,wherethe block size isfor WL’s scheme and for our scheme.Note that in this case the WL scheme can embed at most 1bit in each block,and ours unconditionallybits in each block.Our datahiding ratio is at least 10/4higher than WL’s.C)Equal Amount of Embedded Data:Here we further equalize the amount of embedded data (by adjusting the block sizes)so as the compare the image quality after data hiding.The results are in parts (f)and (g)of Fig.5,and Fig.6.Note that since the data hiding ratio of the WL scheme will depend on the nature of the host image,we have to choose the block sizes that deliver approximately the same amount of hidden data to make the comparison.Speciﬁcally,the block sizesused in Fig.5(f),Fig.5(g),Fig.6(f),and Fig.6(g)are,,,,,and ,respectively.Clearly,our results deliver much better image quality.Finally,we comment that in both WL and our schemes,the security will depend on the block size used.In both items B and C of the above experiments,larger block sizes are used in our scheme,thus providing another advantage of higher secu-rity.5ConclusionWe have presented a new steganography scheme for hiding data in a binary image.The main idea is to use a secret key andFig. 6.Embedding effect on image “Micky”(obtained from the Disney World):(a)the original host image,(b)after embedding338bytes by our scheme with block size,(c)after embedding83bytes by WL schemewith block size,(d)after embedding103 bytes by our scheme with block size,(e) after embedding34bytes by WL scheme with block size,(f)after embedding180bytes by our scheme with block size,and(g) after embedding180bytes by WL scheme with block size.[9]G.J.Simmons.The Prisoners’Problem and the SubliminalChannel.In CRYPTO’83,pages51–67.[10]G.J.Simmons.Results Concerning the Bandwidth of Sublim-inal Channels.IEEE J.on Selected Areas in Communications, 16(4):463–473,May1998.[11]G.J.Simmons.The History of Subliminal Channels.IEEEJ.on Selected Areas in Communications,16(4):452–462,May 1998.[12]W.Stallings.Cryptography and Network Security.PrenticeHall,New Jersey,1999.[13]R.G.van Schyndel,A.Z.Tirkel,and C.F.Osborne.A DigitalWatermark.In IEEE Int.Conf.Image Processing,volume2, pages86–90,1994.[14]R.Z.Wang,C.F.Lin,and J.C.Lin.Image Hiding by LSB Sub-stitution and Genetic Algorithm.In Proceedings of International Symposium on Multimedia Information Processing,Chung-Li, Taiwan,R.O.C,December1998.[15]P.Wayner.Should encryption be regulated.Byte,May1993.[16]P.W.Wong.A Public key Watermark for Image Veriﬁcationand Authentication.In Proceedings of International Conference on Image Processing,Chicago,Illinois,USA,October1998. [17]P.W.Wong.A Watermark for Image Integrity and OwnershipVeriﬁcation.In Proceedings of IS T PIC Conference,Portland, Oregon,USA,May1998.[18]M.Y.Wu and J.H.Lee.A Novel Data Embedding Method forTwo-Color Facsimile Images.In Proceedings of International Symposium on Multimedia Information Processing,Chung-Li, Taiwan,R.O.C,December1998.。

高中英语科技前沿词汇单选题50题

高中英语科技前沿词汇单选题50题1. In the field of artificial intelligence, the process of training a model to recognize patterns is called _____.A. data miningB. machine learningC. deep learningD. natural language processing答案：B。

本题主要考查人工智能领域中的相关概念。

选项A“data mining”指数据挖掘，侧重于从大量数据中提取有价值的信息。

选项B“machine learning”指机器学习，强调通过数据让模型自动学习和改进，符合训练模型识别模式的描述。

选项C“deep learning”是机器学习的一个分支，专注于使用深度神经网络。

选项D“natural language processing”是自然语言处理，主要涉及对人类语言的理解和处理。

2. When developing an AI system for image recognition, the most important factor is _____.A. large datasetsB. advanced algorithmsC. powerful hardwareD. skilled developers答案：A。

在开发用于图像识别的人工智能系统时，选项A“large datasets”（大型数据集）是最重要的因素，因为丰富的数据能让模型学习到更多的特征和模式。

选项B“advanced algorithms”（（先进算法）虽然重要，但没有足够的数据也难以发挥作用。

选项C“powerful hardware”（（强大的硬件）有助于提高处理速度，但不是最关键的。

选项D“skilled developers”（（熟练的开发人员）是必要的，但数据的质量和数量对系统性能的影响更为直接。

2024年全国医学博士英语统一考试模拟测试卷

2024年全国医学博士英语统一考试模拟测试卷2024 National Medical Doctor English Unified Examination Simulated Test PaperPart I. Multiple Choice Questions1. Which of the following medications is a common treatment for hypertension?A. InsulinB. AspirinC. LisinoprilD. Ibuprofen2. Which branch of the nervous system is responsible for the fight or flight response?A. ParasympatheticB. SympatheticC. CentralD. Peripheral3. What is the function of the pancreas?A. Regulate blood sugar levelsB. Produce bileC. Aid in digestionD. Store iron4. A patient experiencing shortness of breath and chest pain may be suffering from:A. DiabetesB. AsthmaC. Heart attackD. Migraines5. Which of the following is not a symptom of the flu?A. CoughB. FeverC. HeadacheD. RashPart II. Short Answer Questions1. Explain the difference between Type 1 and Type 2 diabetes.2. What is the role of cholesterol in the body?3. Describe the difference between a virus and a bacterium.4. How does the immune system protect the body from infections?5. What are the benefits of regular exercise for overall health?Part III. Case StudyA 45-year-old female patient presents with complaints of fatigue, weight gain, and cold intolerance. She has a family history of thyroid disease. Upon examination, her thyroid gland is enlarged and tender to the touch. Laboratory tests reveal elevated levels of thyroid-stimulating hormone (TSH) and low levels of thyroxine (T4). Based on these findings, what is the most likely diagnosis and treatment plan for this patient?Part IV. EssayDiscuss the importance of communication skills in the medical field. How do effective communication skills benefit both healthcare providers and patients? Provide examples of how communication breakdowns can lead to errors in patient care and outcomes.Remember to answer all questions thoroughly and to show all work where applicable. Good luck on your exam!---该模拟测试卷提供了全方位的医学知识考核，包括选择题、简答题、案例分析和论文题。

Lectures on Loop Quantum Gravity

5
6 6 9 15 16 20 22 22 25
I.2
I.3
II Mathematical and Physical Foundations of Quantum General Relativity 28
II.1 Mathematical Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II.1.1 Polarization and Preferred Poisson Algebra B . . . . . . . . . . . . . . . . . . II.1.2 Representation Theory of B and Suitable Kinematical Representations . . . . II.1.2.1 Curves, Paths, Graphs and Groupoids . . . . . . . . . . . . . . . . . II.1.2.2 Topology on A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II.1.2.3 Measures on A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II.1.2.4 Representation Property . . . . . . . . . . . . . . . . . . . . . . . . II.2 Quantum Kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II.2.1 The Space of Solutions to the Gauss and Spatial Diﬀeomorphism Constraint II.2.2 Kinematical Geometrical Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 29 33 33 35 36 39 40 41 42

高三英语科学前沿动态引人关注单选题30题及答案

高三英语科学前沿动态引人关注单选题30题及答案1.The new technology, known as AI, is changing our lives rapidly. Which of the following is NOT an application of AI?A.Face recognitionB.V oice assistantC.Manual laborD.Autonomous driving答案：C。

本题考查对人工智能（AI）应用的了解。

选项A“Face recognition”（人脸识别）、选项B“V oice assistant”（语音助手）和选项D“Autonomous driving”（自动驾驶）都是人工智能的常见应用。

而选项C“Manual labor” 体力劳动）并非人工智能的应用。

2.In the field of scientific research, quantum computing is considereda revolutionary technology. What is the main advantage of quantum computing over traditional computing?A.Higher speedB.Lower costC.Smaller sizeD.Easier operation答案：A。

本题考查量子计算的优势。

量子计算相比传统计算的主要优势是更高的速度。

选项B“Lower cost” 更低成本）、选项C“Smaller size”（更小尺寸）和选项D“Easier operation”（更容易操作）都不是量子计算的主要优势。

3.The development of 5G technology has brought many changes. Which of the following is NOT a feature of 5G?A.High speedB.Low latencyC.Narrow bandwidthD.Massive connectivity答案：C。

九年级英语科研技术单选题50题

九年级英语科研技术单选题50题1. In the field of artificial intelligence research, the term "algorithm" refers to _.A. a set of computational steps and rules for performing a specific taskB. a physical device used for data storageC. a type of software for graphic designD. a chemical substance for experiments答案：A。

解析：“algorithm”（算法）的定义就是执行特定任务的一组计算步骤和规则。

选项B，用于数据存储的物理设备是硬盘、U 盘等，不是算法的含义。

选项C，用于图形设计的软件有Photoshop 等，和算法概念不同。

选项D，算法与化学实验物质毫无关系。

2. When scientists conduct genetic research, they often study "DNA replication". "Replication" here means _.A. the process of making an exact copy of DNAB. the destruction of DNA structureC. the separation of different DNA segmentsD. the combination of DNA with other substances答案：A。

解析：“replication”在“DNA replication”DNA复制）中的意思就是制造DNA精确副本的过程。

选项B，破坏DNA结构不是“replication”的含义。

英文科技论文写作_北京理工大学中国大学mooc课后章节答案期末考试题库2023年

英文科技论文写作_北京理工大学中国大学mooc课后章节答案期末考试题库2023年1.If a real physical system shows a variation of both material properties acrossthe graded layer, the assumed linear variation may not give the bestapproximation.答案:may2.The idea of 'community' in terms of GRT lives is very strong and could beseen to correspond to some of the nostalgic constructs that non-GRT groups place on 'community'.答案:could be seen3.Is the research topic “How safe is nuclear power” effective?答案:正确4.Decide whether the following statement is true or false.c.Introductionincludes more detailed information than abstract.答案:正确5.Tertiary education may be ________ asthe period of study which is spent atuniversity.答案:defined6.Unbalanced Force ________ tothe sum total or net force exerted on an object.答案:refers7.This scatter can be attributed to the difficulties in measuring the dent depthdue to specimen processing.答案:can be attributed8.Choose a proper word from the choices to complete the following sentence.Arocket traveling away from Earth ____________ a speed greater than 11.186kilometers per second (6.95 miles per second) or 40,270 kilometers per hour (25,023 mph) will eventually escape Earth’s gravity.答案:at9.Choose a proper word from the choices to complete the following sentence.Inmechanical systems, power, the rate of doing work, can be computed____________ the product of force × velocity.答案:as10.Choose a proper word from the choices to complete the followingsentence.N ewton’s first law, the law of inertia, __________ that it takes a force to change the motion of an object.答案:states11.Choose a proper word from the choices to complete the followingsentence.Newton’s second law relates force, acceleration, and mass and it is often ___________ as the equation:f = ma答案:written12.Choose a proper word from the choices to complete the followingsentence.Because all types of energy can be expressed ___________ the sameunits, joules, this conversion can be expressed quantitatively in simplemodels.答案:in13.Choose a proper word from the choices to complete the followingsentence.So a key difference between a rocket and a jet plane is ____________ a rocket’s engine lifts it directly upward into the sky, whereas a jet’s engin es simply speed the plane forward so its wings can generate lift.答案:that14.Which of the following are the guidelines for writing formulas and equations?答案:Numbering all equations in sequence if referred to later._Centeringequations on their own separate lines._Using equations as grammatical units in sentences._Defining the symbols that are used.15.Acceleration relates to motion. It ________ a change in motion.答案:means16.Assertiveness is ________ asa skill of being able to stand up for your own orother people's rights in a calm and positive way, without being eitheraggressive, or passively accepting 'wrong'.答案:viewed17.The force that pushes a rocket upward is ________ thrust.答案:called18.Water ________ a liquid made up of molecules of hydrogen and oxygen in theratio of 2 to 1.答案:is19.The number of private cars increased ______60% from 2015 to 2016.答案:by20.Which can be the situations for writing a researchproposal?答案:Applying for an opportunity for a project_Applying for a bachelor’s, or master’s or doctor’s degree_Applying for some research funds or grants21.Who are usually the readers of the research proposals?答案:Specialists_Professors_Supervisors for the students_Professionals22.What are the elements to make the research proposal persuasive?答案:Reasonable budget_Clear Schedule_A Capable research team_Theimportance and necessity of the research question23.What are the language features of the research proposal?答案:Future tense_First person24.The purpose of writing a proposal is to ________________ the readers that theresearch plan is feasible and we are capable to do it.答案:persuade25.What types of information are generally supposed to be included in theintroduction section in the report?答案:Background_Summary of the results and conclusion_The purpose of the research26.Please decide whether the following statement is T(true) orF(false)according to the video.Discussion section analyzesand evaluates the research methods.答案:错误27.Please decide whether the following statement is T(true) orF(false)according to the video.Conclusion and recommendation sectionstates the significance of the findings and usually includes possible directions for further research.答案:正确28.These causes affected different regions differently in the 1990s, ______ Europehaving as much as 9.8% of degradation due to deforestation.答案:with29.Coal is predicted to increase steadily to 31q in 2030, whereas gas will remainstable ______ 25q.答案:at30.Manufacturing value added amounted ______12.3% of total U.S. grossdomestic product (GDP) in 2012, according to United Nations calculations.答案:to31.Chinese manufacturing value added accounted ______ 30.6% of its economy’stotal output in 2012, according to the UN.答案:for32.Japan ranked third ______ manufacturing value added at $1.1 trillion (seeFigure 1).答案:in33.About 4.2% of the 1,120 respondents were younger than 20 years, and 26.7%were ______ 21 and 30 years old.答案:between34.______ all the respondents, 67.1% were married and 32.9% were single.答案:of35.Decide whether the following statement is true or false.b.Both introductionand abstract include research findings.答案:错误36.Decide whether the following statement is true or false.a.It is possible to findtables or diagrams in introduction.答案:正确37.What are the possible contents of an introduction?答案:Reviewing the existing literature relevant to the presentstudy_Announcing the purpose/focus of the study_Identifying a gap in the existing literature_Explaining the significance or necessity of the research38.Choose the proper answers for the following questions.Ways to organize thereferences include:答案:a. Chronological order of publications_b. Researchmethods_c. Research theories_d. Research modes39.This indicates that there is a possibility of obtaining fluid density from soundspeed measurements and suggests that it is possible to measure soundabsorption with an ultrasonic cell to determine oil viscosity.In this sentence, the writer presents答案:Implication40.The measurements were shown to lead to an accurate determination of thebubble point of the oil.In this sentence, the writer presents答案:Results and achievement41.An ultrasonic cell was constructed to measure the speed of sound and testedin a crude oil sample. The speed of sound was measured at temperaturesbetween 260 and 411 K at pressures up to 75 MPs.In this sentence, thewriter presents答案:Methodology42.The aim of this study was to investigate the use of an ultrasonic cell todetermine crude oil properties, in particular oil density.In this sentence, the writer presents答案:Research aim43. A citation gives the s____ where the information or idea is from.答案:source44.An in-text citation usually includes information about the author and thep____ year.答案:publishing##%_YZPRLFH_%##publication45.To avoid plagiarism, using citations is the best way to give c____ to theoriginal author.答案:credit46.The publication details of the references listed at the end of the paper usuallyare put in a____ order.答案:alphabetical##%_YZPRLFH_%##alphabetic##%_YZPRLFH_%##alphab et47.The speed of sound in a fluid is determined by, and therefore an indicator of,the thermodynamic properties of that fluid.In this sentence, the writerpresents答案:Background factual information48.Citations are not necessary if the source is not clear.答案:错误49.Unintentional plagiarism can be excused.答案:错误50.Citing will make our writing less original.答案:错误51.Citing can effectively stress the originality of someone’s work.答案:正确52.As for the purposes of a literature review, which one is not included?答案:predicting the trend in relation to a central research question orhypothesis53. A literature review could be possibly presented as a/an ______.答案:all of the above54.The heading “Brief review of literature: drawing a timeline from 2005 to2017” shows the literature review is arranged in ______ order.答案:chronological55.About writing a literature review, which of the following statements is notcorrect?答案:To show respect to others’ work, our own interpretations should not be included.56.In terms of the writing feature, a research paper resembles a/an______.答案:argumentation57.Each citation can only have one particular citing purpose.答案:错误pared with in-text citations, the end-of-text references are more detailed.答案:正确59.In-text citations provide the abbreviation of an author’s given/first namerather than family/last name.答案:错误60.When the Chinese writers’ ideas are cited, the first names in Pinyin will begiven in in-text citations.答案:错误61.When a process is described, _____________ are usually used to show the orderof the stages or steps.答案:sequencers62.To help the reader better understand a complicated process, _____________ is(are) very often used.答案:visual aids63.What information is usually included when defining a process?答案:Equipment._Product_Material64.Decide whether the following statement is true or false.Researchers arerequired to use past tense when describing a process.答案:错误65.Decide whether the following statement is true or false.A definition of theprocess is very often given first when a process is described.答案:正确66.Escherichia coli, when found in conjunction with urethritis, often indicateinfection higher in the uro-genital tract.答案:正确67.The 'management' of danger is also not the sort of language to appear withinpolicy documents that refer to GRT children, which reflects systematicfailures in schools.错误68.Conceivably, different forms, changing at different rates and showingcontrasting combinations of characteristics, were present in different areas.答案:正确69.Viewing a movie in which alcohol is portrayed appears to lead to higher totalalcohol consumption of young people while watching the movie.答案:正确70.Furthermore, this proves that humans are wired to imitate.答案:错误71.One possibility is that generalized latent inhibition is likely to be weaker thanthat produced by pre-exposure to the CS itself and thus is more likely to be susceptible to the effect of the long interval.答案:正确72.It is unquestionable that our survey proved that the portrayal of alcohol anddrinking characters in movies directly leads to more alcohol consumption in young adult male viewers when alcohol is available within the situation.错误73.Implications of these findings may be that, if moderation of alcoholconsumption in certain groups is strived for, it may be sensible to cut down on the portrayal of alcohol in programmes aimed at these groups and thecommercials shown in between.答案:正确74.This effect might occur regardless of whether it concerns a real-lifeinteraction.答案:正确75.It definitely proves that a movie in which a lot of partying is involved triggersa social process between two participants that affects total drinking amounts.答案:错误76.It is believed that alcohol related health problems are on the rise.答案:believed77.Drinking to excess, or 'binge drinking' is often the cause of inappropriatebehaviour amongst teenagers.often78.It seems as though the experiment conducted simply confirms suspicionsheld by the academic and medical professions.答案:seems79.However, attrition was greatest among the heaviest drinking segment of thesample, suggesting under-estimation in the findings, and although the study provided associational, prospective evidence on alcohol advertising effects on youth drinking, it addressed limitations of other research, particularly the unreliability of exposure measures based on self-reporting (Synder andSlater, 2006).答案:suggesting80.These differences may be due to the fact participants reporting higherconsumption levels were primed to overrate their weekly drinking by the condition they were in.答案:may81.The crack tends to grow into the more brittle material and then stay in there,whether the initial crack tip lies in the graded material or in the more ductile material (and thereafter advances across the graded layer.答案:tends82.Decidewhether hedging language is used in thesentence below.Light smokingseems to have dramatic effects on cardiovascular disease.答案:正确83.Decidewhether hedging language is used in thesentence below.The impact ofthe UK’s ageing population will lead to increased welfare costs. Definitely,this will result in higher taxes and an increased retirement age for younger people.答案:错误84.Decidewhether hedging language is used in thesentence below.Althoughduration of smoking is also important when considering risk, it is highlycorrelated with age, which itself is a risk factor, so separating their effectscan be difficult.答案:正确85.Decidewhether hedging language is used in thesentence below.All these factstaken together point toward the likely presence of calcium carbonate in the soils that Phoenix has analyzed.答案:正确86.Decidewhether hedging language is used in thesentence below.Because thesefeatures are carved into the Tharsis Plateau, they must have an intermediate age.答案:错误87.Decidewhether hedging language is used in thesentence below.They appearto be covered with multiple layers of volcanic flows and sedimentary debris that originated in the south.答案:正确88.Decidewhether hedging language is used in thesentence below.Steven M.Clifford of the Lunar and Planetary Science Institute in Houston, amongothers, has conjectured that melting under a glacier or a thick layer ofpermafrost could also have recharged subterranean water sources.答案:正确89.Decidewhether hedging language is used in thesentence below.Earlier thisyear Philip Christensen of Arizona State University discovered gullies that clearly emerge from underneath a bank of snow and ice.答案:错误90.Put the following expressions in the proper place of the Discussion.A. Thesedata suggestB. In this study, we demonstrate C. it is critical to emphasizeD.additional research will be requiredE. we were unable todetermineDiscussionIndividuals who recover from certain viral infections typically develop virus-specific antibody responses that provide robustprotective immunity against re-exposure, but some viruses do not generate protective natural immunity, such as HIV-1. Human challenge studies for the common cold coronavirus 229E have suggested that there may be partialnatural immunity. However, there is currently no data whether humans who have recovered from SARS-CoV-2 infection are protected from re-exposure.This is a critical issue with profound implications for vaccine development, public health strategies, antibody-based therapeutics, and epidemiologicmodeling of herd immunity. _____1_______ that SARS-CoV-2 infection in rhesusmacaques provided protective efficacy against SARS-CoV-2 rechallenge.We developed a rhesus macaque model of SARS-CoV-2 infection thatrecapitulates many aspects of human SARS-CoV-2 infection, including high levels of viral replication in the upper and lower respiratory tract and clear pathologic evidence of viral pneumonia. Histopathology,immunohistochemistry, RNAscope, and CyCIF imaging demonstratedmultifocal clusters of virus infected cells in areas of acute inflammation, with evidence for virus infection of alveolar pneumocytes and ciliated bronchial epithelial cells. ______2_______ the utility of rhesus macaques as a model forSARS-CoV-2 infection for testing vaccines and therapeutics and for studying immunopathogenesis. However, neither nonhuman primate model led torespiratory failure or mortality, and thus further research will be required to develop a nonhuman primate model of severe COVID-19 disease.SARS-CoV-2 infection in rhesus macaques led to humoral and cellular immune responses and provided protection against rechallenge. Residual low levels ofsubgenomic mRNA in nasal swabs in a subset of animals and anamnesticimmune responses in all animals following SARS-CoV-2 rechallenge suggest that protection was mediated by immunologic control and likely was notsterilizing.Given the near-complete protection in all animals following SARS-CoV-2 rechallenge, ______3_______ immune correlates of protection in thisstudy. SARS-CoV-2 infection in rhesus monkeys resulted in the induction of neutralizing antibody titers of approximately 100 by both a pseudovirusneutralization assay and a live virus neutralization assay, but the relativeimportance of neutralizing antibodies, other functional antibodies, cellular immunity, and innate immunity to protective efficacy against SARS-CoV-2remains to be determined. Moreover, ______4_______ to define the durability of natural immunity.In summary, SARS-CoV-2 infection in rhesus macaquesinduced humoral and cellular immune responses and provided protectiveefficacy against SARS-CoV-2 rechallenge. These data raise the possibility that immunologic approaches to the prevention and treatment of SARS-CoV-2infection may in fact be possible. However,______5_______ that there areimportant differences between SARS-CoV-2 infection in macaques andhumans, with many parameters still yet to be defined in both species, andthus our data should be interpreted cautiously. Rigorous clinical studies will be required to determine whether SARS-CoV-2 infection effectively protects against SARS-CoV-2 re-exposure in humans.答案:BAEDC91.Rearrange the order of the following sentences to make a coherent andmeaningful abstract.1.These antibodies neutralized 10 representative SARS-CoV-2 strains, suggesting a possible broader neutralizing ability against otherstrains. Three immunizations using two different doses, 3 or 6 micrograms per dose, provided partial or complete protection in macaques against SARS-CoV-2 challenge, respectively, without observable antibody-dependentenhancement of infection.2.The coronavirus disease 2019 (COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has resulted in an unprecedented public health crisis. Because of the novelty of the virus, there are currently no SARS-CoV-2–specifictreatments or vaccines available.3.Therefore, rapid development of effective vaccines against SARS-CoV-2 are urgently needed.4.Here, we developed apilot-scale production of PiCoVacc, a purified inactivated SARS-CoV-2 virus vaccine candidate, which induced SARS-CoV-2–specific neutralizingantibodies in mice, rats, and nonhuman primates.5.These data support the clinical development and testing of PiCoVacc for use in humans.答案:2341592.It seems likely that the details of the predictions depend on the assumedvariations of the toughness parameter and the yield stress.答案:It seems likely that93.The Relationships of Meteorological Factors and Nutrient Levels withPhytoplankton Biomass in a Shallow Eutrophic Lake Dominated byCyanobacteria, Lake Dianchi from 1991 to 2013A. The SHs, WS, and TPconcentrations controlled the bloom dynamics during the dry season, among which the TP concentration was the most important factors, whereas the TN and TP concentrations were the primary factors during the rainy season.B.Interannual analysis revealed that the phytoplankton biomass increased with increases in air temperature and TP concentration, with TP concentration as the main contributing factor.C. The results of our study demonstrated that both meteorological factors and nutrient levels had important roles incontrolling cyanobacterial bloom dynamics.D. All of these results suggest that both climate change regulation and eutrophication management should be considered in strategies aimed at controlling cyanobacterial blooms.E. Insummary, we analyzed the effects of meteorological factors and nutrientlevels on bloom dynamics in Lake Dianchi to represent the phytoplanktonbiomass.F. Further studies should assess the effects of climate change andeutrophication on cyanobacterial bloom dynamics based on data collected over a longer duration and more frequent and complete variables, andappropriate measures should be proposed to control these blooms.G.Decreasing nutrient levels, particularly the TP load should be initiallyconsidered during the entire period and during the dry season, anddecreasing both the TN and TP loads should be considered during the rainy season.H. However, the relative importance of these factors may changeaccording to precipitation patterns.1.2.B3.A4.G5.5. __________答案:F94.The Relationships of Meteorological Factors and Nutrient Levels withPhytoplankton Biomass in a Shallow Eutrophic Lake Dominated byCyanobacteria, Lake Dianchi from 1991 to 2013A. The SHs, WS, and TPconcentrations controlled the bloom dynamics during the dry season, among which the TP concentration was the most important factors, whereas the TN and TP concentrations were the primary factors during the rainy season.B.Interannual analysis revealed that the phytoplankton biomass increased with increases in air temperature and TP concentration, with TP concentration as the main contributing factor.C. The results of our study demonstrated that both meteorological factors and nutrient levels had important roles incontrolling cyanobacterial bloom dynamics.D. All of these results suggest that both climate change regulation and eutrophication management should be considered in strategies aimed at controlling cyanobacterial blooms.E. Insummary, we analyzed the effects of meteorological factors and nutrientlevels on bloom dynamics in Lake Dianchi to represent the phytoplanktonbiomass.F. Further studies should assess the effects of climate change andeutrophication on cyanobacterial bloom dynamics based on data collected over a longer duration and more frequent and complete variables, andappropriate measures should be proposed to control these blooms.G.Decreasing nutrient levels, particularly the TP load should be initiallyconsidered during the entire period and during the dry season, anddecreasing both the TN and TP loads should be considered during the rainy season.H. However, the relative importance of these factors may changeaccording to precipitation patterns.1.2.B3.A4.G5.4. __________答案:D95.The Relationships of Meteorological Factors and Nutrient Levels withPhytoplankton Biomass in a Shallow Eutrophic Lake Dominated byCyanobacteria, Lake Dianchi from 1991 to 2013A. The SHs, WS, and TPconcentrations controlled the bloom dynamics during the dry season, among which the TP concentration was the most important factors, whereas the TN and TP concentrations were the primary factors during the rainy season.B.Interannual analysis revealed that the phytoplankton biomass increased with increases in air temperature and TP concentration, with TP concentration as the main contributing factor.C. The results of our study demonstrated that both meteorological factors and nutrient levels had important roles incontrolling cyanobacterial bloom dynamics.D. All of these results suggest that both climate change regulation and eutrophication management should be considered in strategies aimed at controlling cyanobacterial blooms.E. Insummary, we analyzed the effects of meteorological factors and nutrientlevels on bloom dynamics in Lake Dianchi to represent the phytoplanktonbiomass.F. Further studies should assess the effects of climate change andeutrophication on cyanobacterial bloom dynamics based on data collected over a longer duration and more frequent and complete variables, andappropriate measures should be proposed to control these blooms.G.Decreasing nutrient levels, particularly the TP load should be initiallyconsidered during the entire period and during the dry season, anddecreasing both the TN and TP loads should be considered during the rainy season.H. However, the relative importance of these factors may changeaccording to precipitation patterns.1.2.B3.A4.G5.3. __________答案:H96.The Relationships of Meteorological Factors and Nutrient Levels withPhytoplankton Biomass in a Shallow Eutrophic Lake Dominated byCyanobacteria, Lake Dianchi from 1991 to 2013A. The SHs, WS, and TPconcentrations controlled the bloom dynamics during the dry season, among which the TP concentration was the most important factors, whereas the TN and TP concentrations were the primary factors during the rainy season.B.Interannual analysis revealed that the phytoplankton biomass increased with increases in air temperature and TP concentration, with TP concentration as the main contributing factor.C. The results of our study demonstrated that both meteorological factors and nutrient levels had important roles incontrolling cyanobacterial bloom dynamics.D. All of these results suggest that both climate change regulation and eutrophication management should be considered in strategies aimed at controlling cyanobacterial blooms.E. Insummary, we analyzed the effects of meteorological factors and nutrientlevels on bloom dynamics in Lake Dianchi to represent the phytoplanktonbiomass.F. Further studies should assess the effects of climate change andeutrophication on cyanobacterial bloom dynamics based on data collected over a longer duration and more frequent and complete variables, andappropriate measures should be proposed to control these blooms.G.Decreasing nutrient levels, particularly the TP load should be initiallyconsidered during the entire period and during the dry season, anddecreasing both the TN and TP loads should be considered during the rainy season.H. However, the relative importance of these factors may changeaccording to precipitation patterns.1.2.B3.A4.G5.2. __________答案:C97.The Relationships of Meteorological Factors and Nutrient Levels withPhytoplankton Biomass in a Shallow Eutrophic Lake Dominated byCyanobacteria, Lake Dianchi from 1991 to 2013A. The SHs, WS, and TPconcentrations controlled the bloom dynamics during the dry season, among which the TP concentration was the most important factors, whereas the TN and TP concentrations were the primary factors during the rainy season.B.Interannual analysis revealed that the phytoplankton biomass increased with increases in air temperature and TP concentration, with TP concentration as the main contributing factor.C. The results of our study demonstrated that both meteorological factors and nutrient levels had important roles incontrolling cyanobacterial bloom dynamics.D. All of these results suggest that both climate change regulation and eutrophication management should be considered in strategies aimed at controlling cyanobacterial blooms.E. Insummary, we analyzed the effects of meteorological factors and nutrientlevels on bloom dynamics in Lake Dianchi to represent the phytoplanktonbiomass.F. Further studies should assess the effects of climate change andeutrophication on cyanobacterial bloom dynamics based on data collected over a longer duration and more frequent and complete variables, andappropriate measures should be proposed to control these blooms.G.Decreasing nutrient levels, particularly the TP load should be initiallyconsidered during the entire period and during the dry season, anddecreasing both the TN and TP loads should be considered during the rainy season.H. However, the relative importance of these factors may changeaccording to precipitation patterns.1.2.B3.A4.G5.1. __________答案:E98.It is rare to offer recommendations forfuture researchin Conclusion section.。

AS1系列指南手册说明书

AS1 SERIESINSTRUCTION MANUALCONTROLSOUT LED on receiver (RX)The yellow LED ON indicates the presence of the object into controlled area.POWER ON LED on receiver (RX)The green LED ON indicates the optimal device functioning.The fast blinking of the green LED indicates a critical device alignment. Please refer to “DIAGNOSTICS” paragraph for other indications.POWER ON LED on emitter (TX)The green LED ON indicates the correct device functioning.Please refer to “DIAGNOSTICS” paragraph for other indications.INSTALLATION MODEGeneral information on device positioning• Align the two receiver (RX) and emitter (TX) units, verifying that their distance is inside the device operating distance, in a parallel manner placing the sensitive sides one in front of the other, with the connectors oriented on the same side. The critical alignmentof the unit will be signalled by the fast blinking of the green receiver LED.• Mount the two receiver and emitter units on rigid supports which are not subject to strong vibrations, using specific fixing brackets and /or the holes present on the device lids.Precautions to respect when choosing and installing the device• Choose the device according to the minimum object to detect and the maximum controlled area requested.• In agro-industrial applications, the compatibility of light grid housing material and any chemical agents used in the production process has to be verified with the assistance of the DATASENSOR technical sales support department.• The AREA scan TM light grids are NOT safety devices, and so MUST NOT be used in the safety control of the machines where installed. Moreover the following points have to be considered:- Avoid installation near very intense and / or blinking light sources, in particular near to the receiver unit.- The presence of strong electromagnetic disturbances can jeopardise the correct functioning of the device. This condition has to be carefully evaluated and checked with the DATASENSOR technical sales support department;- The presence of smoke, fog and suspended dust in the working environment can reduce the device’s operating distance.- Strong and frequent temperature variations, with very low peak temperatures, can generate a thin condensation layer on the optics surfaces, compromising the correct functioning of the device.- Reflecting surfaces near the luminous beam of the AREA scan TM device (above, under or lateral) can cause passive reflections able to compromise object detection inside the controlled area.- if different devices have to be installed in adjacent areas, the emitter of one unit must not interfere with the receiver of the other unit.General information relative to object detection and measurement• For a correct object detection and / or measurement, the object has to pass completely through the controlled area. Testing the correct detection before beginning the process is suggested. The resolution is non uniform inside the entire controlled area. For example the resolution in the AS1-HR model depends on the scanning program chosen.CONNECTIONSAS1-HR AS1-SR AS1-HR AS1-SR1 – brown: +24 VDC +24 VDC 1 – brown: +24 VDC+24 VDC2 – white:SEL_RXNot used2 – white:SEL_TX Not used3 – blue: 0 V0 V3 – blue: 0 V 0 V4 – black: Switching output Switching output 4 – black:SYNC SYNCRECEIVER (RX):M12 5-pole connector5 – grey: SYNC SYNCEMITTER (TX):M12 4-pole connectorShielded cables are not foreseen in the standard connection.Ground connection of the two units is not necessary. If desired, this connection can be obtained replacing the screw provided in the packaging with the one indicated in the drawing, which blocks the lid of the connector side of each unit.The respect of the connection shown in the drawing, is necessary if ground connection of the entire system is requested.FUNCTIONING AND PERFORMANCESThe beam interruption due to the passage of an object inside the controlled area causes the closing of the switching output and the variation of the device analogue output signal. Small objects can be detected (reaching dimensions of only 0.5 mm) and with a reduced surface area.In particular:The switching output is always activated when at least one beam is obscured. The status variation is signalled by the yellow receiver LED that turns on.The device presents inputs (both on TX and Rx units) that consent the selection of the resolution and response time.Low response times correspond to worser resolutions and viceversa.The device does not require calibration; periodical checks of the resolution and / or measurement are however suggested.The blinking of the green receiver LED (stability function ) signals the critical alignment of the units and / or the functioning outside or near the maximum operating distance. In optimal conditions the LED remains on continuously.The two units are synchronised via cable (SYNC wire).Precarious connections or induced disturbances on the synchronism line can cause device malfunctioning or a temporary blocking.DIAGNOSTICSRECEIVER UNIT:Segnal StatusCauseActionONSwitching output.Presence of the object in the controlled area.OUT LEDOFFSwitching output.Controlled area free of objects.ONOptimal functioning. Fast blinkingCritical alignment of the unit or/and functioning closed to maximum operating distance.Slow blinkingWrong connections and/or malfunctioning.- Verify the output connections and any short-circuits.- Switch OFF and switch ON the device.- If condition persists, contact Datasensor.POWER ONLEDOFFDevice is not powered.- Verify the connections.- If condition persists, contact Datasensor.EMITTER UNIT:POWER ONLEDPROG. N°SEL_RXSEL_TXRESOLUTIONRESPONSE TIME (msec )1 0V or FLOAT 0V or FLOAT LOW 2.752 0V or FLOAT +24Vdc M/L3 3 +24Vdc 0V or FLOAT M/H 7.754 +24Vdc +24Vdc HIGH 8Resolution figure : the box indicated the area with highest resolutionPROGRAM 1PROGRAM 2PROGRAM 3 - 4Ideal for fast detection on entire controlled area, with low resolution.Ideal for fast detection on entire contolled area, with constant resolution onlimited area.Ideal for detection with high resolution on entirecontrolled area.DIMENSIONS 800-262-4332-------------------------------------------------------------------------------------------------------------------------------------------- DECLARATION OF CONFORMITYIDEC and DATASENSOR jointly declare under their sole responsibility that these products conform to the 2004/108/CE, 2006/95/CE Directives, and successive amendments.-------------------------------------------------------------------------------------------------------------------------------------------- IDEC and DATASENSOR reserve the right to make modifications and improvements without prior notification.826003450 Rev.00。

高三英语科学前沿动态单选题50题(答案解析)

高三英语科学前沿动态单选题50题(答案解析)1.Scientists have made a breakthrough in the field of artificial intelligence. The new technology is called deep learning. What is deep learning?A.A kind of softwareB.A branch of mathematicsC.A method of machine learningD.A type of computer hardware答案：C。

deep learning 是深度学习，是一种机器学习的方法。

选项A，它不是一种软件；选项B，不是数学的一个分支；选项D，不是一种计算机硬件。

2.The latest scientific discovery is a new element. What is an element?A.A compoundB.A mixtureC.A substance made up of only one kind of atomD.A solution答案：C。

element 是元素，是由一种原子组成的物质。

选项A，compound 是化合物；选项B，mixture 是混合物；选项D，solution 是溶液。

3.In the field of space exploration, a satellite is launched. What is a satellite?A.A spaceshipB.A planetC.An object that orbits a planet or other celestial bodyD.A star答案：C。

satellite 是卫星，是围绕行星或其他天体运行的物体。

选项A，spaceship 是宇宙飞船；选项B，planet 是行星；选项D，star 是恒星。

专八英语阅读

英语专业八级考试TEM-8阅读理解练习册（1）(英语专业2012级)UNIT 1Text AEvery minute of every day, what ecologist生态学家James Carlton calls a global ―conveyor belt‖, redistributes ocean organisms生物.It’s planetwide biological disruption生物的破坏that scientists have barely begun to understand.Dr. Carlton —an oceanographer at Williams College in Williamstown,Mass.—explains that, at any given moment, ―There are several thousand marine species traveling… in the ballast water of ships.‖ These creatures move from coastal waters where they fit into the local web of life to places where some of them could tear that web apart. This is the larger dimension of the infamous无耻的，邪恶的invasion of fish-destroying, pipe-clogging zebra mussels有斑马纹的贻贝.Such voracious贪婪的invaders at least make their presence known. What concerns Carlton and his fellow marine ecologists is the lack of knowledge about the hundreds of alien invaders that quietly enter coastal waters around the world every day. Many of them probably just die out. Some benignly亲切地，仁慈地—or even beneficially — join the local scene. But some will make trouble.In one sense, this is an old story. Organisms have ridden ships for centuries. They have clung to hulls and come along with cargo. What’s new is the scale and speed of the migrations made possible by the massive volume of ship-ballast water压载水— taken in to provide ship stability—continuously moving around the world…Ships load up with ballast water and its inhabitants in coastal waters of one port and dump the ballast in another port that may be thousands of kilometers away. A single load can run to hundreds of gallons. Some larger ships take on as much as 40 million gallons. The creatures that come along tend to be in their larva free-floating stage. When discharged排出in alien waters they can mature into crabs, jellyfish水母, slugs鼻涕虫，蛞蝓, and many other forms.Since the problem involves coastal species, simply banning ballast dumps in coastal waters would, in theory, solve it. Coastal organisms in ballast water that is flushed into midocean would not survive. Such a ban has worked for North American Inland Waterway. But it would be hard to enforce it worldwide. Heating ballast water or straining it should also halt the species spread. But before any such worldwide regulations were imposed, scientists would need a clearer view of what is going on.The continuous shuffling洗牌of marine organisms has changed the biology of the sea on a global scale. It can have devastating effects as in the case of the American comb jellyfish that recently invaded the Black Sea. It has destroyed that sea’s anchovy鳀鱼fishery by eating anchovy eggs. It may soon spread to western and northern European waters.The maritime nations that created the biological ―conveyor belt‖ should support a coordinated international effort to find out what is going on and what should be done about it. (456 words)1.According to Dr. Carlton, ocean organism‟s are_______.A.being moved to new environmentsB.destroying the planetC.succumbing to the zebra musselD.developing alien characteristics2.Oceanographers海洋学家are concerned because_________.A.their knowledge of this phenomenon is limitedB.they believe the oceans are dyingC.they fear an invasion from outer-spaceD.they have identified thousands of alien webs3.According to marine ecologists, transplanted marinespecies____________.A.may upset the ecosystems of coastal watersB.are all compatible with one anotherC.can only survive in their home watersD.sometimes disrupt shipping lanes4.The identified cause of the problem is_______.A.the rapidity with which larvae matureB. a common practice of the shipping industryC. a centuries old speciesD.the world wide movement of ocean currents5.The article suggests that a solution to the problem__________.A.is unlikely to be identifiedB.must precede further researchC.is hypothetically假设地，假想地easyD.will limit global shippingText BNew …Endangered‟ List Targets Many US RiversIt is hard to think of a major natural resource or pollution issue in North America today that does not affect rivers.Farm chemical runoff残渣, industrial waste, urban storm sewers, sewage treatment, mining, logging, grazing放牧,military bases, residential and business development, hydropower水力发电,loss of wetlands. The list goes on.Legislation like the Clean Water Act and Wild and Scenic Rivers Act have provided some protection, but threats continue.The Environmental Protection Agency (EPA) reported yesterday that an assessment of 642,000 miles of rivers and streams showed 34 percent in less than good condition. In a major study of the Clean Water Act, the Natural Resources Defense Council last fall reported that poison runoff impairs损害more than 125,000 miles of rivers.More recently, the NRDC and Izaak Walton League warned that pollution and loss of wetlands—made worse by last year’s flooding—is degrading恶化the Mississippi River ecosystem.On Tuesday, the conservation group保护组织American Rivers issued its annual list of 10 ―endangered‖ and 20 ―threatened‖ rivers in 32 states, the District of Colombia, and Canada.At the top of the list is the Clarks Fork of the Yellowstone River, whereCanadian mining firms plan to build a 74-acre英亩reservoir水库，蓄水池as part of a gold mine less than three miles from Yellowstone National Park. The reservoir would hold the runoff from the sulfuric acid 硫酸used to extract gold from crushed rock.―In the event this tailings pond failed, the impact to th e greater Yellowstone ecosystem would be cataclysmic大变动的，灾难性的and the damage irreversible不可逆转的.‖ Sen. Max Baucus of Montana, chairman of the Environment and Public Works Committee, wrote to Noranda Minerals Inc., an owner of the ― New World Mine‖.Last fall, an EPA official expressed concern about the mine and its potential impact, especially the plastic-lined storage reservoir. ― I am unaware of any studies evaluating how a tailings pond尾矿池，残渣池could be maintained to ensure its structural integrity forev er,‖ said Stephen Hoffman, chief of the EPA’s Mining Waste Section. ―It is my opinion that underwater disposal of tailings at New World may present a potentially significant threat to human health and the environment.‖The results of an environmental-impact statement, now being drafted by the Forest Service and Montana Department of State Lands, could determine the mine’s future…In its recent proposal to reauthorize the Clean Water Act, the Clinton administration noted ―dramatically improved water quality since 1972,‖ when the act was passed. But it also reported that 30 percent of riverscontinue to be degraded, mainly by silt泥沙and nutrients from farm and urban runoff, combined sewer overflows, and municipal sewage城市污水. Bottom sediments沉积物are contaminated污染in more than 1,000 waterways, the administration reported in releasing its proposal in January. Between 60 and 80 percent of riparian corridors (riverbank lands) have been degraded.As with endangered species and their habitats in forests and deserts, the complexity of ecosystems is seen in rivers and the effects of development----beyond the obvious threats of industrial pollution, municipal waste, and in-stream diversions改道to slake消除the thirst of new communities in dry regions like the Southwes t…While there are many political hurdles障碍ahead, reauthorization of the Clean Water Act this year holds promise for US rivers. Rep. Norm Mineta of California, who chairs the House Committee overseeing the bill, calls it ―probably the most important env ironmental legislation this Congress will enact.‖ (553 words)6.According to the passage, the Clean Water Act______.A.has been ineffectiveB.will definitely be renewedC.has never been evaluatedD.was enacted some 30 years ago7.“Endangered” rivers are _________.A.catalogued annuallyB.less polluted than ―threatened rivers‖C.caused by floodingD.adjacent to large cities8.The “cataclysmic” event referred to in paragraph eight would be__________.A. fortuitous偶然的，意外的B. adventitious外加的，偶然的C. catastrophicD. precarious不稳定的，危险的9. The owners of the New World Mine appear to be______.A. ecologically aware of the impact of miningB. determined to construct a safe tailings pondC. indifferent to the concerns voiced by the EPAD. willing to relocate operations10. The passage conveys the impression that_______.A. Canadians are disinterested in natural resourcesB. private and public environmental groups aboundC. river banks are erodingD. the majority of US rivers are in poor conditionText CA classic series of experiments to determine the effects ofoverpopulation on communities of rats was reported in February of 1962 in an article in Scientific American. The experiments were conducted by a psychologist, John B. Calhoun and his associates. In each of these experiments, an equal number of male and female adult rats were placed in an enclosure and given an adequate supply of food, water, and other necessities. The rat populations were allowed to increase. Calhoun knew from experience approximately how many rats could live in the enclosures without experiencing stress due to overcrowding. He allowed the population to increase to approximately twice this number. Then he stabilized the population by removing offspring that were not dependent on their mothers. He and his associates then carefully observed and recorded behavior in these overpopulated communities. At the end of their experiments, Calhoun and his associates were able to conclude that overcrowding causes a breakdown in the normal social relationships among rats, a kind of social disease. The rats in the experiments did not follow the same patterns of behavior as rats would in a community without overcrowding.The females in the rat population were the most seriously affected by the high population density: They showed deviant异常的maternal behavior; they did not behave as mother rats normally do. In fact, many of the pups幼兽，幼崽, as rat babies are called, died as a result of poor maternal care. For example, mothers sometimes abandoned their pups,and, without their mothers' care, the pups died. Under normal conditions, a mother rat would not leave her pups alone to die. However, the experiments verified that in overpopulated communities, mother rats do not behave normally. Their behavior may be considered pathologically 病理上，病理学地diseased.The dominant males in the rat population were the least affected by overpopulation. Each of these strong males claimed an area of the enclosure as his own. Therefore, these individuals did not experience the overcrowding in the same way as the other rats did. The fact that the dominant males had adequate space in which to live may explain why they were not as seriously affected by overpopulation as the other rats. However, dominant males did behave pathologically at times. Their antisocial behavior consisted of attacks on weaker male,female, and immature rats. This deviant behavior showed that even though the dominant males had enough living space, they too were affected by the general overcrowding in the enclosure.Non-dominant males in the experimental rat communities also exhibited deviant social behavior. Some withdrew completely; they moved very little and ate and drank at times when the other rats were sleeping in order to avoid contact with them. Other non-dominant males were hyperactive; they were much more active than is normal, chasing other rats and fighting each other. This segment of the rat population, likeall the other parts, was affected by the overpopulation.The behavior of the non-dominant males and of the other components of the rat population has parallels in human behavior. People in densely populated areas exhibit deviant behavior similar to that of the rats in Calhoun's experiments. In large urban areas such as New York City, London, Mexican City, and Cairo, there are abandoned children. There are cruel, powerful individuals, both men and women. There are also people who withdraw and people who become hyperactive. The quantity of other forms of social pathology such as murder, rape, and robbery also frequently occur in densely populated human communities. Is the principal cause of these disorders overpopulation? Calhoun’s experiments suggest that it might be. In any case, social scientists and city planners have been influenced by the results of this series of experiments.11. Paragraph l is organized according to__________.A. reasonsB. descriptionC. examplesD. definition12．Calhoun stabilized the rat population_________.A. when it was double the number that could live in the enclosure without stressB. by removing young ratsC. at a constant number of adult rats in the enclosureD. all of the above are correct13.W hich of the following inferences CANNOT be made from theinformation inPara. 1?A. Calhoun's experiment is still considered important today.B. Overpopulation causes pathological behavior in rat populations.C. Stress does not occur in rat communities unless there is overcrowding.D. Calhoun had experimented with rats before.14. Which of the following behavior didn‟t happen in this experiment?A. All the male rats exhibited pathological behavior.B. Mother rats abandoned their pups.C. Female rats showed deviant maternal behavior.D. Mother rats left their rat babies alone.15. The main idea of the paragraph three is that __________.A. dominant males had adequate living spaceB. dominant males were not as seriously affected by overcrowding as the otherratsC. dominant males attacked weaker ratsD. the strongest males are always able to adapt to bad conditionsText DThe first mention of slavery in the statutes法令，法规of the English colonies of North America does not occur until after 1660—some forty years after the importation of the first Black people. Lest we think that existed in fact before it did in law, Oscar and Mary Handlin assure us, that the status of B lack people down to the 1660’s was that of servants. A critique批判of the Handlins’ interpretation of why legal slavery did not appear until the 1660’s suggests that assumptions about the relation between slavery and racial prejudice should be reexamined, and that explanation for the different treatment of Black slaves in North and South America should be expanded.The Handlins explain the appearance of legal slavery by arguing that, during the 1660’s, the position of white servants was improving relative to that of black servants. Thus, the Handlins contend, Black and White servants, heretofore treated alike, each attained a different status. There are, however, important objections to this argument. First, the Handlins cannot adequately demonstrate that t he White servant’s position was improving, during and after the 1660’s; several acts of the Maryland and Virginia legislatures indicate otherwise. Another flaw in the Handlins’ interpretation is their assumption that prior to the establishment of legal slavery there was no discrimination against Black people. It is true that before the 1660’s Black people were rarely called slaves. But this shouldnot overshadow evidence from the 1630’s on that points to racial discrimination without using the term slavery. Such discrimination sometimes stopped short of lifetime servitude or inherited status—the two attributes of true slavery—yet in other cases it included both. The Handlins’ argument excludes the real possibility that Black people in the English colonies were never treated as the equals of White people.The possibility has important ramifications后果，影响.If from the outset Black people were discriminated against, then legal slavery should be viewed as a reflection and an extension of racial prejudice rather than, as many historians including the Handlins have argued, the cause of prejudice. In addition, the existence of discrimination before the advent of legal slavery offers a further explanation for the harsher treatment of Black slaves in North than in South America. Freyre and Tannenbaum have rightly argued that the lack of certain traditions in North America—such as a Roman conception of slavery and a Roman Catholic emphasis on equality— explains why the treatment of Black slaves was more severe there than in the Spanish and Portuguese colonies of South America. But this cannot be the whole explanation since it is merely negative, based only on a lack of something. A more compelling令人信服的explanation is that the early and sometimes extreme racial discrimination in the English colonies helped determine the particular nature of the slavery that followed. (462 words)16. Which of the following is the most logical inference to be drawn from the passage about the effects of “several acts of the Maryland and Virginia legislatures” (Para.2) passed during and after the 1660‟s?A. The acts negatively affected the pre-1660’s position of Black as wellas of White servants.B. The acts had the effect of impairing rather than improving theposition of White servants relative to what it had been before the 1660’s.C. The acts had a different effect on the position of white servants thandid many of the acts passed during this time by the legislatures of other colonies.D. The acts, at the very least, caused the position of White servants toremain no better than it had been before the 1660’s.17. With which of the following statements regarding the status ofBlack people in the English colonies of North America before the 1660‟s would the author be LEAST likely to agree?A. Although black people were not legally considered to be slaves,they were often called slaves.B. Although subject to some discrimination, black people had a higherlegal status than they did after the 1660’s.C. Although sometimes subject to lifetime servitude, black peoplewere not legally considered to be slaves.D. Although often not treated the same as White people, black people,like many white people, possessed the legal status of servants.18. According to the passage, the Handlins have argued which of thefollowing about the relationship between racial prejudice and the institution of legal slavery in the English colonies of North America?A. Racial prejudice and the institution of slavery arose simultaneously.B. Racial prejudice most often the form of the imposition of inheritedstatus, one of the attributes of slavery.C. The source of racial prejudice was the institution of slavery.D. Because of the influence of the Roman Catholic Church, racialprejudice sometimes did not result in slavery.19. The passage suggests that the existence of a Roman conception ofslavery in Spanish and Portuguese colonies had the effect of _________.A. extending rather than causing racial prejudice in these coloniesB. hastening the legalization of slavery in these colonies.C. mitigating some of the conditions of slavery for black people in these coloniesD. delaying the introduction of slavery into the English colonies20. The author considers the explanation put forward by Freyre andTannenbaum for the treatment accorded B lack slaves in the English colonies of North America to be _____________.A. ambitious but misguidedB. valid有根据的but limitedC. popular but suspectD. anachronistic过时的，时代错误的and controversialUNIT 2Text AThe sea lay like an unbroken mirror all around the pine-girt, lonely shores of Orr’s Island. Tall, kingly spruce s wore their regal王室的crowns of cones high in air, sparkling with diamonds of clear exuded gum流出的树胶; vast old hemlocks铁杉of primeval原始的growth stood darkling in their forest shadows, their branches hung with long hoary moss久远的青苔;while feathery larches羽毛般的落叶松,turned to brilliant gold by autumn frosts, lighted up the darker shadows of the evergreens. It was one of those hazy朦胧的, calm, dissolving days of Indian summer, when everything is so quiet that the fainest kiss of the wave on the beach can be heard, and white clouds seem to faint into the blue of the sky, and soft swathing一长条bands of violet vapor make all earth look dreamy, and give to the sharp, clear-cut outlines of the northern landscape all those mysteries of light and shade which impart such tenderness to Italian scenery.The funeral was over,--- the tread鞋底的花纹/ 踏of many feet, bearing the heavy burden of two broken lives, had been to the lonely graveyard, and had come back again,--- each footstep lighter and more unconstrained不受拘束的as each one went his way from the great old tragedy of Death to the common cheerful of Life.The solemn black clock stood swaying with its eternal ―tick-tock, tick-tock,‖ in the kitchen of the brown house on Orr’s Island. There was there that sense of a stillness that can be felt,---such as settles down on a dwelling住处when any of its inmates have passed through its doors for the last time, to go whence they shall not return. The best room was shut up and darkened, with only so much light as could fall through a little heart-shaped hole in the window-shutter,---for except on solemn visits, or prayer-meetings or weddings, or funerals, that room formed no part of the daily family scenery.The kitchen was clean and ample, hearth灶台, and oven on one side, and rows of old-fashioned splint-bottomed chairs against the wall. A table scoured to snowy whiteness, and a little work-stand whereon lay the Bible, the Missionary Herald, and the Weekly Christian Mirror, before named, formed the principal furniture. One feature, however, must not be forgotten, ---a great sea-chest水手用的储物箱,which had been the companion of Zephaniah through all the countries of the earth. Old, and battered破旧的，磨损的, and unsightly难看的it looked, yet report said that there was good store within which men for the most part respect more than anything else; and, indeed it proved often when a deed of grace was to be done--- when a woman was suddenly made a widow in a coast gale大风，狂风, or a fishing-smack小渔船was run down in the fogs off the banks, leaving in some neighboring cottage a family of orphans,---in all such cases, the opening of this sea-chest was an event of good omen 预兆to the bereaved丧亲者;for Zephaniah had a large heart and a large hand, and was apt有…的倾向to take it out full of silver dollars when once it went in. So the ark of the covenant约柜could not have been looked on with more reverence崇敬than the neighbours usually showed to Captain Pennel’s sea-chest.1. The author describes Orr‟s Island in a(n)______way.A.emotionally appealing, imaginativeB.rational, logically preciseC.factually detailed, objectiveD.vague, uncertain2.According to the passage, the “best room”_____.A.has its many windows boarded upB.has had the furniture removedC.is used only on formal and ceremonious occasionsD.is the busiest room in the house3.From the description of the kitchen we can infer that thehouse belongs to people who_____.A.never have guestsB.like modern appliancesC.are probably religiousD.dislike housework4.The passage implies that_______.A.few people attended the funeralB.fishing is a secure vocationC.the island is densely populatedD.the house belonged to the deceased5.From the description of Zephaniah we can see thathe_________.A.was physically a very big manB.preferred the lonely life of a sailorC.always stayed at homeD.was frugal and saved a lotText BBasic to any understanding of Canada in the 20 years after the Second World War is the country' s impressive population growth. For every three Canadians in 1945, there were over five in 1966. In September 1966 Canada's population passed the 20 million mark. Most of this surging growth came from natural increase. The depression of the 1930s and the war had held back marriages, and the catching-up process began after 1945. The baby boom continued through the decade of the 1950s, producing a population increase of nearly fifteen percent in the five years from 1951 to 1956. This rate of increase had been exceeded only once before in Canada's history, in the decade before 1911 when the prairies were being settled. Undoubtedly, the good economic conditions of the 1950s supported a growth in the population, but the expansion also derived from a trend toward earlier marriages and an increase in the average size of families; In 1957 the Canadian birth rate stood at 28 per thousand, one of the highest in the world. After the peak year of 1957, thebirth rate in Canada began to decline. It continued falling until in 1966 it stood at the lowest level in 25 years. Partly this decline reflected the low level of births during the depression and the war, but it was also caused by changes in Canadian society. Young people were staying at school longer, more women were working; young married couples were buying automobiles or houses before starting families; rising living standards were cutting down the size of families. It appeared that Canada was once more falling in step with the trend toward smaller families that had occurred all through theWestern world since the time of the Industrial Revolution. Although the growth in Canada’s population had slowed down by 1966 (the cent), another increase in the first half of the 1960s was only nine percent), another large population wave was coming over the horizon. It would be composed of the children of the children who were born during the period of the high birth rate prior to 1957.6. What does the passage mainly discuss?A. Educational changes in Canadian society.B. Canada during the Second World War.C. Population trends in postwar Canada.D. Standards of living in Canada.7. According to the passage, when did Canada's baby boom begin?A. In the decade after 1911.B. After 1945.C. During the depression of the 1930s.D. In 1966.8. The author suggests that in Canada during the 1950s____________.A. the urban population decreased rapidlyB. fewer people marriedC. economic conditions were poorD. the birth rate was very high9. When was the birth rate in Canada at its lowest postwar level?A. 1966.B. 1957.C. 1956.D. 1951.10. The author mentions all of the following as causes of declines inpopulation growth after 1957 EXCEPT_________________.A. people being better educatedB. people getting married earlierC. better standards of livingD. couples buying houses11.I t can be inferred from the passage that before the IndustrialRevolution_______________.A. families were largerB. population statistics were unreliableC. the population grew steadilyD. economic conditions were badText CI was just a boy when my father brought me to Harlem for the first time, almost 50 years ago. We stayed at the hotel Theresa, a grand brick structure at 125th Street and Seventh avenue. Once, in the hotel restaurant, my father pointed out Joe Louis. He even got Mr. Brown, the hotel manager, to introduce me to him, a bit punchy强力的but still champ焦急as fast as I was concerned.Much has changed since then. Business and real estate are booming. Some say a new renaissance is under way. Others decry责难what they see as outside forces running roughshod肆意践踏over the old Harlem. New York meant Harlem to me, and as a young man I visited it whenever I could. But many of my old haunts are gone. The Theresa shut down in 1966. National chains that once ignored Harlem now anticipate yuppie money and want pieces of this prime Manhattan real estate. So here I am on a hot August afternoon, sitting in a Starbucks that two years ago opened a block away from the Theresa, snatching抓取，攫取at memories between sips of high-priced coffee. I am about to open up a piece of the old Harlem---the New York Amsterdam News---when a tourist。

2025届河南省示范中学高考仿真卷英语试卷含解析

2025届河南省示范中学高考仿真卷英语试卷考生须知：1．全卷分选择题和非选择题两部分，全部在答题纸上作答。

选择题必须用2B铅笔填涂；非选择题的答案必须用黑色字迹的钢笔或答字笔写在“答题纸”相应位置上。

2．请用黑色字迹的钢笔或答字笔在“答题纸”上先填写姓名和准考证号。

3．保持卡面清洁，不要折叠，不要弄破、弄皱，在草稿纸、试题卷上答题无效。

第一部分（共20小题，每小题1.5分，满分30分）1．The earthquake in Japan, measuring 9.0 on the Richter Scale, was so violent _______ cause a series of explosions of the nuclear reactors in several power stations.A．to B．that C．as to D．as that2．Taught in a more professional way, you _________ the swimming skill much better.A．might master B．would have masteredC．can have mastered D．could master3．— Who recommended Nancy for the post?— It was James ______ admiration for her was obvious.A．who B．that C．whose D．whom4．--- I have been working for more than 30 years! I’m going to retire next month.--- Really? You don’t look a day 40!A．over B．byC．with D．for5．The inner thoughts of the two young persons are revealed in the book, ______ both of them fail to express. A．where B．whenC．who D．which6．—I have got a headache.—No wonder.Y ou___in front of that computer too long.A．work B．are workingC．have been working D．worked7．—I was intended to to the concert with you this weekend, but I can’t now.—______.A．Bad B．That’s rightC．Not at all D．Y ou’re welcome8．The new playground to be built next year will be ____________ the old one.A．as three times big as B．three times as big asC．as big as three times D．as big three times as9．He is confident, ________________ in my opinion, is most important in society.A．how B．whichC．that D．what10．Look, ____ fashionable clothes is she wearing that all the eyes are fixed on her!A．so B．such C．how D．what11．The fellow we spoke ________ no comment at first.A．to make B．to madeC．made D．to making12．I got more _____ about him from reading his books than from talking to him.A．insights B．memoriesC．resources D．experiences13．Thanks to Chinese people’s hard work and wisdom, China has _____ into the second largest economy. A．evolved B．slipped C．extended D．shaped14．—Did Max go to the concert with his family yesterday?—The report scheduled to be handed in tomorrow, he _______ it.A．couldn’t have attended B．needn’t have attendedC．wouldn’t attend D．shouldn’t attend15．People who drink and drive are ________ danger both to themselves and to others. They are in ________ danger of losing their lives.A．the; the B．a; a C．a; / D．/; /16．The flat is good value for money because not only did they sell it to me at a cheap price, but they threw in some old furniture _________.A．at their command B．for good measureC．beyond my reach D．beneath their dignity17．—Simon will listen to music every time he comes across a maths problem.—You know, music is the source of ______ in life.A．inspiration B．identificationC．reaction D．recreation18．I' ve heard that preparations______for the coming festival. Let's give them a hand.A．are being made B．have been madeC．are making D．have made19．Don’ t be joking. It’ s time to______your business.A．set out B．take up C．go on D．get down20．I had hoped to take a holiday this year but I wasn’t able to ______.A．get away B．drop in C．check out D．hold on第二部分阅读理解（满分40分）阅读下列短文，从每题所给的A、B、C、D四个选项中，选出最佳选项。

高考英语阅读理解高级单选题40题

高考英语阅读理解高级单选题40题1. Scientists predict that in the future, artificial intelligence (AI) will be able to perform complex surgeries. What can we infer from this statement?A. AI will replace all human doctorsB. Surgeries will become less risky with AIC. AI has already mastered all surgical skillsD. Human surgeons will no longer be needed in the future答案：B。

解析：文章提到人工智能将来能够进行复杂手术。

A选项说人工智能将取代所有人类医生过于绝对，文章只是说能进行手术，并没有说取代所有医生；C选项中说人工智能已经掌握所有手术技能，原文是将来能够，并非已经，所以错误；D选项说未来不再需要人类外科医生也是过于绝对，所以排除A、C、D，B选项说手术因为人工智能而风险降低是合理的推断。

2. The latest research on space exploration shows that a new planet might have water. What does this discovery most likely mean?A. There must be life on this planetB. It is possible for the planet to support lifeC. Humans can move to this planet immediatelyD. The planet has the same environment as Earth答案：B。

放射医学(医学高级)：MRI考试考试题模拟考试卷_0.doc

放射医学(医学高级)：MRI 考试考试题模拟考试卷考试时间：120分钟考试总分：100分题号一二三四五总分分数遵守考场纪律，维护知识尊严，杜绝违纪行为，确保考试结果公正。

1、单项选择题女，55岁，1年前出现头痛，头昏，症状间断性加重，半年后出现视物模糊，且视力逐步下降，以右侧为甚，根据所提供图像，最可能的诊断是（）A.动脉瘤B.颅咽管瘤C.垂体腺瘤D.脑膜瘤E.神经纤维瘤本题答案：C 本题解析：暂无解析 2、单项选择题患者临床最常见的症状为（）A.杵状指 B.类癌综合征 C.咳嗽D.眼睑不能上抬姓名：________________ 班级：________________ 学号：________________--------------------密----------------------------------封 ----------------------------------------------线----------------------E.咯血本题答案：D本题解析：解题思路：胸腺瘤临床表现中除纵隔肿瘤的一般表现外，还有其典型的临床表现：约有30%的胸腺瘤患者出现重症肌无力。

3、单项选择题女，23岁，闭经1年余，MRI检查如图，最可能的诊断为（）A.脑膜瘤B.表皮样囊肿C.颅咽管瘤D.蛛网膜囊肿E.垂体瘤本题答案：E本题解析：暂无解析4、单项选择题男，23岁，2年前无明显诱因下出现右腰腿部疼痛，呈阵发性钝痛，根据所提供图像，最可能的诊断是（）A.脊膜瘤B.神经鞘瘤C.神经纤维瘤D.淋巴瘤E.胶质瘤本题答案：B本题解析：暂无解析5、单项选择题属于超高磁场MR的是（）A.0.35TB.0.15TC.1.0TD.1.5TE.3.0T本题答案：E本题解析：暂无解析6、单项选择题MRISE序列T1加权像上能分辨肾皮、髓质是因为（）A.肾皮质呈高信号，肾髓质呈等信号B.肾皮质比髓质信号弱C.肾髓质含较多自由水，信号较皮质低D.肾皮髓质均有化学位移伪影E.肾窦内脂肪衬托本题答案：C本题解析：暂无解析7、单项选择题关于肿瘤复发及放射性肺炎的说法，错误的是（）A.放射性肺炎急性期的病理反应主要为渗出B.放射性肺炎急性期MRI表现为T1WI低或中等信号，T2WI高信号C.放射性肺炎急性期与肿瘤复发不易鉴别D.放射性肺炎慢性期与肿瘤复发不易鉴别E.肿瘤在MRIT2WI呈略高信号本题答案：D本题解析：暂无解析8、单项选择题T1加权像及质子密度加权像中等信号，T2加权像高信号最可能为下列哪种组织。

DIRAC A High Resolution Spectrometer for Pionium Detection

a r X i v :h e p -e x /0305022v 1 13 M a y 2003DIRAC:A High Resolution Spectrometer forPionium DetectionB.Adeva p ,∗,L.Afanasyev ℓ,M.Benayoun e ,A.Benelli q ,Z.Berka b ,V.Brekhovskikh o ,G.Caragheorgheopol m ,T.Cechak b ,M.Chiba k ,E.Cima f ,S.Constantinescu m ,C.Detraz a ,D.Dreossi g ,D.Drijard a ,A.Dudarev ℓ,I.Evangelou d ,M.Ferro-Luzzi a ,M.V.Gallas p ,a ,J.Gerndt b ,R.Giacomich g ,P.Gianotti f ,M.Giardoni f ,D.Goldin q ,F.G´o mez p ,A.Gorin o ,O.Gortchakov ℓ,C.Guaraldo f ,M.Hansroul a ,M.Iliescu f ,m ,M.Zhabitsky ℓ,V.Karpukhin ℓ,J.Kluson b ,M.Kobayashi h ,P.Kokkas d ,V.Komarov ℓ,V.Kruglov ℓ,L.Kruglova ℓ,A.Kulikov ℓ,A.Kuptsov ℓ,V.Kurochkin o ,K.-I.Kuroda ℓ,mberto g ,naro a ,f ,pshin o ,R.Lednicky c ,P.Leruste e ,P.Levisandri f ,A.Lopez Aguera p ,V.Lucherini f ,T.Maki j ,N.Manthos d ,I.Manuilov o ,L.Montanet a ,J.-L.Narjoux e ,L.Nemenov a ,ℓ,M.Nikitin ℓ,T.N´u ˜n ez Pardo p ,K.Okada i ,V.Olchevskii ℓ,D.Orecchini f ,A.Pazos p ,M.Pentia m ,A.Penzo g ,J.-M.Perreau a ,C.Petrascu f ,m ,M.Pl´o p ,T.Ponta m ,D.Pop m ,G.F.Rappazzo g ,A.Riazantsev o ,J.M.Rodriguez p ,A.Rodriguez Fernandez p ,A.Romero p ,V.Rykalin o ,C.Santamarina p ,q ,J.Saborido p ,J.Schacher r ,Ch.P.Schuetz q ,A.Sidorov o ,J.Smolik c ,M.Steinacher q ,F.Takeutchi i ,A.Tarasov ℓ,L.Tauscher q ,M.J.Tobar p ,F.Triantis d ,S.Trusov n ,V.Utkin ℓ,O.V´a zquez Doce p ,P.V´a zquez p ,S.Vlachos q ,V.Yazkov n ,Y.Yoshimura h ,P.Zrelov ℓa CERN,Geneva,Switzerland b Czech Technical University,Prague,Czech Republicc Institute of Physics ACSR,Prague,Czech Republicd IoanninaUniversity,Ioannina,Greece e LPNHEdes Universites Paris VI/VII,IN2P3-CNRS,France f INFN -Laboratori Nazionali di Frascati,Frascati,Italyg INFN-Trieste and Trieste University,Trieste,Italyh KEK,Tsukuba,Japani Kyoto Sangyou University,Japanj UOEH-Kyushu,Japank Tokyo Metropolitan University,JapanℓJINR Dubna,Russiam National Institute for Physics and Nuclear Engineering IFIN-HH Bucharest,Romanian Skobeltsin Institute for Nuclear Physics of Moscow State University Moscow,Russiao IHEP Protvino,Russiap Santiago de Compostela University,Spainq Basel University,Switzerlandr Bern University,Switzerland1IntroductionThe DIRAC experiment aims to measure the ground state lifetime ofπ+π−atoms with10%precision,using the24GeV/c proton beam of the CERN Proton Synchrotron.The atom lifetime is a consequence of the strong inter-action at low energy and it is determined by the charge exchange amplitudeπ+π−→π0π0very close to threshold.The probability of this process is pro-portional to the square of the diﬀerence of S-waveππscattering lengths withisotopic spin0and2,|a0−a2|2.The relation between the lifetime and|a0−a2| is model-independent[1].The pion scattering lengths have been calculated in the framework of chiral perturbation theory with a precision of a few percent: a0=0.220±0.005and a2=−0.0444±ing these values one can predict the pionium lifetime[2]:(2.9±0.1)×10−15s.In order to determine |a0−a2|down to5%,the lifetime has to be measured within10%accuracy. Such a measurement would provide a crucial test for the understanding of chiral symmetry breaking in QCD.Pionium atoms(A2π)are produced in proton-nucleus interactions.After pro-duction these relativistic atoms may either decay intoπ0π0or get excited to higher quantum numbers,or break up(be ionised)in the target material where they are produced.In the case of break-up,characteristic pion pairs(“atomic”pairs)emerge.These pairs have a low relative momentum in their centre of mass system(Q<3MeV/c),very small opening angle(θ<3mrad)and nearly identical energies in the laboratory system.A high resolution magnetic spectrometer is then required[3]to split up the pairs and measure their rel-ative momentum with suﬃcient precision(0.6MeV/c)to detect the pionium signal superimposed on the substantial background of“free”π+π−pairs pro-duced in inclusive proton-nucleus interactions.A previous experiment,using internal proton beam,has reported observation of pionium atoms[4].The total number of producedπ+π−atoms is related by an exact expressionto the number of free pion pairs with low relative momenta.For a given target material and thickness the ratio of observed atomic pairs to the total number of produced atoms,i.e.the atom breakup probability,depends on the lifetime in a unique way[5].2General layout of the experimental setupThe DIRAC experimental setup[6,7]is located at the T8proton beam line of24GeV/c momentum in the East Hall of the PS accelerator at CERN. The isometric view of the setup is shown in Fig.1.The DIRAC apparatusis designed to detect charged pion pairs with high resolution over the pair relative momentum.It became operational at the end of1998and has been collecting data since the middle of1999.Fig.1.Isometric view of the DIRAC setup.The radiation shielding boundaries are shown on theﬂoor(each division marked on the boundary corresponds to1meter).Fig.2.Side view of the DIRAC setup.The secondary particle channel is inclined by5.7◦with respect to the primary proton beam.The setup consists of the proton beam line,target station,secondary particle vacuum channel,spectrometer magnet and detectors placed upstream and downstream the analysing magnet.Free and atomicπ+π−pairs produced in the target enter the secondary particle channel which is tilted upwards by5.7◦with respect to the proton beam(Fig.2).At the end of the secondary particle channel the spectrometer magnet is installed,also tilted by5.7◦together with all the downstream detectors.The top view of the setup is shown in Fig.3.The upstream section of the secondary particle channel between the target station and the spectrometer magnet is instrumented with the following detectors:microstrip gas chambers (GEM/MSGC),scintillatingﬁbre detector(SFD)and scintillation ionisation hodoscope(IH).Downstream the spectrometer magnet the setup splits into two identical arms for detection and identiﬁcation of positive and negative charged particles.The angle between each arm and the spectrometer symmetry axis is19◦.Along each arm the following detectors are located:drift chamber system(DC), vertical scintillation hodoscope(VH),horizontal scintillation hodoscope(HH), gas Cherenkov counter(CH),preshower detector(PSH)and muon detector (MU).3Beam lines,spectrometer magnet and radi-ation shielding3.1Proton beam and target stationTo extract protons from the PS to the T8beam line a slow ejection mode is used.The beam is extracted in spills of≈400–500ms duration.During data taking,between1to5cycles per PS super-cycle of14.4÷19.2s duration areThe target station houses a remote controlled device with12holders for the targets,including an empty holder and a luminescence screen.During data taking,targets made of Pt(28µm thick),Ni(94µm and98µm thick)and Ti(250µm thick)were used.The DIRAC experiment is sensitive to particles outside the beam core(halo), because the target is very thin(nuclear target eﬃciency is<10−3),and the upstream detectors are placed very close(18–26cm in the vertical direction) to the primary proton beam.The halo is originated from scattering of primary protons on the splitter blades,and a special optics has been designed to de-crease the background halo to a negligible level.The ratio of detector counting rates with the target in place to those with an empty holder was measured to be∼25.3.2Secondary particle channel and spectrom-eter magnetThe secondary particle channel[6][7]is placed at an angle of5.7◦relative to the proton beam and consists of two vacuum volumes,as shown in Fig.3. Theﬁrst one is a2m long,611mm diameter tube,located immediately downstream the target station,common to both the proton beam line and the secondary particle channel.Secondary particles exit this tube through a200mm diameter window,made of250µm thick mylarﬁlm.The second volume,located at∼3.5m from the target,consists of a cylindrical vacuum section,containing a collimator,attached to a2.7m longﬂat vacuum chamber placed between the spectrometer magnet poles.A1.5m long air gap between the two vacuum sections allows insertion of the upstream detectors.The angu-lar aperture of the secondary particle channel is determined by the collimator and is equal to±1◦in horizontal and vertical directions resulting in a solid angle acceptance of1.2·10−3sr.Theﬂat chamber is ended with a0.68mm thick Al outlet window of2.0×0.4m2dimensions(W×H).The spectrometer dipole magnet(magneticﬁeld B=1.65T,ﬁeld integral BL= 2.2T·m)has an aperture of1.55×0.50m2(W×H).To reduce the strayﬁeld, two magnetic screens areﬁxed near its entrance and exit.Table1summarises the material thicknesses(in units of radiation length ×10−4)encountered by secondary particles before they reach the DC system where their momenta are measured.Table1Material contributions along the secondary particle channel in units of radiation length×10−4.Ni-targetMylar window224.13planes SFD153.1air gap8.7Al-window765.73.3Beam dump and radiation shielding Neutron and gammaﬂuxes may cause a serious problem to sensitive elements of the setup.To estimate their eﬀect a simulation of the background radiation ﬂux in the full experimental apparatus has been performed[10].The results were used to optimise the design of the radiation shielding which is shown in Fig.4.Fig.4.The DIRAC setup on the T8PS extraction line and the radiation shielding. At the end of the T8beam line primary protons are absorbed by an iron beam dump.To decrease the background gamma and neutronﬂuxes from the beam dump towards the detectors,a dedicated radiation shielding has been adopted. It includes installation of a graphite core into the beam dump area,a concrete wall near the beam dump and,at3m distance,another iron-concrete-iron wall,both with holes to allow passage of the proton beam pipe.The downstream detectors are shielded in addition from background secondary particles produced on the primary proton pipe and surrounding elements.For this purpose a1m thick iron wall is installed between the upstream detectorregion and the spectrometer magnet.In addition,collimators are inserted both in the primary proton beam pipe and in the secondary particle channel.The presence of the collimator in the proton beam line determines a reduction of the background rate by a factor of2.A radiation shielding encloses the whole DIRAC experimental apparatus to protect the surrounding East Hall area from irradiation.It has been designed according to the maximumﬂux of2.7×1010incident protons per second, in respect of the CERN safety regulations.Being the apparatus located in a fully enclosed area,it has become necessary to provide the experimental area with cooling and ventilation equipment to prevent overheating of detectors and electronics.4Large Detectors upstream the magnetTwo tracking devices have been installed in the secondary particle channel before the magnet and the collimator:the GEM/MSGC and the SFD.They are used to improve the resolution on the measurement of the longitudinal and transverse components of the relative momentum of pion pairs as determined by the drift chambers tracking system and the nominal position of the beam at the target center.At the same time these detectors allow to select particle pairs originated by primary interactions at the target from the background of secondary inter-actions and particle decays.The ensemble of MSGC/GEM+SFD constitutes a tracking system with7detector planes with2stereo angles which provides adequate space resolution to reach the limit of multiple scattering in the target material.To increase the detection capability on close-lying tracks,an Ionisation Ho-doscope(IH)is installed downstream the SFD,with the purpose of detecting pion pairs with a too small opening angle to be resolved by the tracking detec-tors.This is achieved by a detailed pulse-hight analysis of the double ionisation produced by the particle pairs in4layers of scintillation counters.A general picture of the above-mentioned detectors,as they are installed be-tween theﬁrst vacuum chamber and the secondary particle channel,can be seen in Figure5.Fig.5.Photography of the three detectors installed upstream the magnet,between theﬁrst vacuum chamber(right-hand side)and the secondary particle channel. From right to left,the GEM/MSGC,SFD and IH detectors can be found.The primary proton beam line can be appreciated at the bottom.5The GEM/MSGC detectorThis detector performs particle tracking at a distance of2.4m from the inter-action point.It is a proportional gas detector,based on the principle of the Gas Electron Ampliﬁer(GEM)[11][12],complemented with a second ampli-ﬁcation and readout stage provided by Micro Strip Gas Chambers(MSGC) [13][14].A more complete description of the detector and its performance is being prepared in a separate publication[15].It measures particle coordinates in4planes along the direction of the incoming particle:X,Y,U,V,with orientations0,90,5,85degrees,respectively,where the0degrees are deﬁned by microstrips running vertically(X-coordinate).The stereo angles allow resolution of ghost combinations for two or more particles. With a single-hit space resolution close to54µm,this detector provides a precise measurement of the pion pair angular opening,ultimately limited by multiple scattering in the thin target.5.1Detector conceptEach chamber has active area10.24×10.24cm2,and consists of a drift elec-trode,a GEM foil and a MSGC sensor.The GEM plane is evenly spaced from the other two with a uniform gap of3mm,as indicated in Fig.6.The drift electrode is made of a Chromium-coated thin glass(200µm).The GEM is a 50µm thick kapton foil copper-cladded on both sides with a4µm thick Cu layer.The etching pattern is characterised by50µm wide holes,140µm apart [16].Application of a potential diﬀerence of400V between the two metal layers(V1=−1600V,V2=−2000V)produces electron ampliﬁcation by a factor of30[12].The MSGC sensor consists of200µm pitch alternating Chromium strips,with 9µm and100µm anode and cathode width,respectively.They are implanted on a bare DESAG D263substrate.Applied voltages are:−410V on cathodes, and−3000V on the drift electrode,whereas anode strips are set to ground. The gas employed is a mixture of Ar-DME(60/40).Under these conservative conditions an overall detector gain of approximately3000is achieved.01000020000300004000050000a)Number of Strips 05001000150020002500b)Number of ClustersFig.7.a)GEM/MSGC strip multiplicity per hit-cluster b)cluster multiplicity per event in one plane (X).The dotted line shows all clusters registered by the data acquisition,whereas the continuous line shows only those having a time tag,es-tablished when the cluster has a corresponding hit in the SFD aligned with the interaction point.5.3PerformanceNeighbouring hit strips are pattern-recognised as clusters.The hit multiplicity in them (a)and the cluster multiplicity per plane (b)are shown in Fig.7.Single hit resolution was determined during the commissioning run in April 2000by setting all planes parallel to each other,and 54µm is a typical value,as shown in Fig.8.Two detector planes were installed in 1999and the full set in 2000.The number of detector dead channels is around 1%and no signiﬁcant deterioration due to radiation has been observed since then.The average eﬃciency for a standard detector is 93%.When at least 4signals among 7detectors are required to make a track,this is suﬃcient to provide 99%overall tracking eﬃciency upstream the magnet.6The Scintillating Fibre DetectorThe Scintillating Fibre Detector (SFD),together with the GEM/MSGC detec-tor,enables particle tracking to be performed upstream the magnet,with the required space and time resolution.In addition,it provides topological trig-ger capabilities [19]for rejection of pairs with relative distances larger than 9mm at the detector location (this feature was used at the early stage of the experiment,see a footnote in section “Trigger system”).Fig.8.Space resolution of the GEM/MSGC detector measured in a dedicated beam-test with 4planes parallel to each other.6.1Detector conceptThe SFD consists of three ﬁbre planes to measure the X-,Y-and U-coordinates of incident particles 1.The SFD covers a 105x105mm 2area,each scintillating ﬁbre (SciFi)array consists of several layers of KURARAY ﬁbres.Five (for planes X and Y)or three (for plane U)ﬁbres forming one sensitive column are mapped onto one channel of position-sensitive photomultiplier (PSPM).A layout illustrating the main characteristics of the SFD (for a plane with 5ﬁbres per column)and PSPM mapping is shown in Fig.9.Fig.9.The SFD principal structure.A16-channel fragment is shown.Theﬁbre columns pitch is0.44mm,thus allowing some overlap to optimise eﬃciency.Each SciFi is connected by optical epoxy to a clearﬁbre light guide of∼300mm length.The edges of clearﬁbres,assembled in a bundle,are carefully polished and glued into the holes of a square black plate whichﬁxes theﬁbre positions on the PSPM photocathode;no optical grease is used.The far end of the SciFi array is tightly connected to a mirror made of aluminised mylar.With this arrangement the light attenuation along the SciFi was found to be negligible.The details of theﬁbre arrays are listed in Table2.Table2SFD planes speciﬁcation.Fibre Fibres/Num.oftype mm%PSPMSCSF381300.815 Y0.505240SCSF78M150, 1.020ode).The measured linear range of this tube(for the linear bleeder)extends up to15photoelectrons at950V.The detector concept with almost independent channels was developed in the context of the RD-17project[20].The results from the SFD study with a test beam of low intensity,reported in[21],are the following:—light output6–10photoelectrons,—average detection eﬃciency98.4%,—r.m.s.of the detection eﬃciency1%,—average hit multiplicity1.1,—spatial resolution(σ)127µm,—time resolution(σ)0.65ns.Fig.10.11the horizontal scale is in TDC channels,the channel width is0.5ns.6.2Readout electronicsA dedicated electronic circuit(PSC)has been custom developed to providesignal discrimination with dynamic rejection of cross-talk in adjacent channels using the peak-sensing technique.A detailed description of a32-channel PSCmodule is given in[22].Discrimination of a channel is given by the condition 2A i−A i−1−A i+1>A thr,where A i are channel signal amplitudes and A thr deﬁnes the threshold value.The PSC algorithm provides eﬃcient detectionof double tracks from time correlated particle pairs(up to∼5ns time dif-ference)when the relative distance between the two tracks is larger than the ﬁbre column pitch.However,when adjacentﬁbre columns are crossed by two particles simultaneously,then the PSC algorithm leads to a suppression(by 20-40%)of the detected yield of double track events.In such cases a signal is detected for only one of two hit columns.The detection eﬃciency depends on the detector light output in a speciﬁc channel.For particle pairs with relative time diﬀerences greater than10ns(accidental pairs)the PSC behaves as an ordinary leading edge discriminator.The front-end electronics is located inside the beam area close to the detector. The PSC output ECL signals are sent to LeCroy3377multi-hit TDC.Thissolution does not require additional delay lines to adjust the timing of the SFD with respect to the trigger timing.6.3Performance in the experimentDue to the highﬂux of particles at the position of the detector close to the target,and to the presence of a non-negligible amount of inclined tracks associ-ated with secondary interactions in the channel,the SFD performances in the experiment slightly diﬀer from the above mentioned.The detection eﬃciency is still high(around98%),but the average hit multiplicity is near5in the 50ns time window of TDC(at a nominal beam intensity of1011protons per spill impinging on a94µm Ni target).The raw time spectra,obtained from e+e−andπ+π−events,are shown in Fig.10and Fig.11,respectively,for two arbitrary SFD channels.The width of the distributions is dominated by the time jitter of the trigger signal.After oﬀ-line deconvolution of the trigger time jitter the resolution of the SFD is found to beσ=0.8ns.7The Ionisation HodoscopeCharged pions originated from pionium breakup cross the upstream detectors at rather small relative distances.When the distance is less than the double track resolution of the upstream tracking devices,then only one hit is de-tected,thus making the event reconstruction ambiguous.That is why another technique based on a measurement of the ionisation loss is used as well.A dedicated Ionisation Hodoscope(IH)[23]has been built to separate double ionisation signals produced by close pion pairs incident on the same scintillat-ing slab,from single ionisation signals produced by one particle.In this way, the uncertainties resulting from the ineﬃciency in detecting two tracks with relative distance approaching zero can be signiﬁcantly reduced.The Ionisation Hodoscope described here was installed in2001to replace a previous version of a similar detector type[24],consisting of only two planes with16slabs of2mm thickness,oriented in the vertical direction.The present IH detector is a scintillation hodoscope consisting of4planes of 11×11cm2sensitive area placed normally to the axis of the setup(Fig.12),3m downstream the target.Two planes have vertically oriented slabs(planes X-A and X-B)whereas the other two have horizontal slabs(planes Y-A and Y-B). They are arranged in the following sequence,moving along the beam direction:Fig.12.Design of the IH scintillation plane.1–scintillators,2–light-guides,3–PM photocathodes.Fig.13.Isometric view of the Ionisation Hodoscope.1–scintillators,2–light-guides, 3–photomultipliers with shielding.X-A,Y-A,X-B,Y-B.This ordering has been chosen to minimise possible cross-correlations between signals in the planes(e.g.due toδ-electrons).Each plane is assembled from16plastic scintillating slabs made of fast scintillator(BC-408).Planes with the same slab orientation are shifted by a half-slab-width with respect to each other.The slabs are11cm long,7mm wide and1mm thick.They are connected to the PM photocathodes via2mm thick and7mm wide lucite light guides(ﬁg.13).The front and rear surfaces of a slab are covered by a milliporeﬁlm[25]for eﬃcient light collection.At the lateral surface of the slab,light is reﬂected by a thin(30µm)aluminised black mylarﬁlm,which is used instead of millipore ﬁlm in order to minimise the gaps between adjacent slabs.A typical gap between two adjacent slabs in this conﬁguration is less than70µm wide. Scintillation light is detected by FEU-85photomultipliers with25mm diame-ter photocathodes.Photomultipliers are assembled by16units into a compact set,allowing independent replacement of each PM.Photocathodes are in op-tical contact with the wide side of a light guide instead of the traditional butt-end readout.This improves the light collection eﬃciency by about50%.8Drift Chambers8.1General layout and characteristicsThe drift chamber system is used to perform particle tracking downstream the dipole magnet.The system is designed to sustain a high particleﬂuency in the secondary channel,reaching10kHz/cm2at the innermost region.A two-arm solution has been chosen,except for theﬁrst chamber which is a single large module(DC-1)designed with two separated sensitive areas0.8×0.4m2each.This chamber provides6successive measurements of the particle trajectory along the coordinates X,Y,W,X,Y,W,where W is a stereo angle with inclination11.3o with respect to the X-coordinate.DC-1is instrumented with800electronic channels.Each of the two arms consists of3chamber modules,of identical design,mea-suring coordinates X,Y(DC-2),X,Y(DC-3)and X,Y,X,Y(DC-4)following the direction of the outgoing particle.Their dimensions are0.8×0.4m2(DC-2),1.12×0.4m2(DC-3),and1.28×0.4m2(DC-4).Both arms together contain 1216electronic channels.The distance between the center of theﬁrst half of DC1and the center of DC4 provides a lever-arm of1.6m along the average particle path,having uniform spacing of chambers DC-2and DC-3along this path.Characteristics of the drift chamber system are summarised in Table3.8.2Drift chamber electrodesA schematic drawing of the sensitive element is shown in Fig.16.The anode wires pitch is10mm,the distance L between the anode and cathode planes is 5mm.The cathode planes and potential wires are at equal voltages.As seen in theﬁgure,a sensitive area,corresponding to each anode wire and limited by the cathode planes and potential wires,has a square(10×10mm2)shape. In this case,with a suitable gas mixture,it is possible to achieve a linear behaviour of the drift function,except in a small region near the potential wire.Cathode planes are made of20µm thick carbon-coated mylar foils with a surface resistivity of about400Ωper square.Such cathode foils provide stable chamber operation due to a high work function of the carbon coating and, being thin,add only small amount of material along the particle path.Table3General properties of the DC modules.Module Measuredarea,cm2planes40×802left arm2240×802right arm2240×801140×1121140×12822Fig.16.Schematic view of the wire chamber electrodes:AW–anode wires,P W–potential wires,C–cathode foils.Dimensions are in mm.Anode and potential wires of50µm and100µm diameter,respectively,are made of a copper-beryllium alloy.The rather large diameter of the anode wires has been chosen in order to operate the chambers at high current avalanche ampliﬁcation mode.8.3Chamber designThe chamber design is shown in Fig.17for the case of the DC-2module.The module is a stack of aluminium andﬁbreglass frames,each of5mm thick-ness,ﬁxed by screws.Theﬁbreglass frames are the supports for the chamber electrodes(anode and potential wires and cathode foils).The two outer alu-minium frames in the stack are used toﬁx the mylar window,and the inner ones are the spacers between theﬁbreglass frames.Rigidity of the module is enforced by aluminium rectangular tubes screwed to the surface of the frame package.Fig.17.Design of the DC-2module.Upperﬁgure:general view.Lowerﬁgure: structure of the frame stack;X–X-plane,Y–Y-plane,C–cathode foils.Gas tightness of the chamber module is provided by rubber o-rings glued along the inner edges of the aluminium frames.Within a module,gasﬂows sequentially in the sub-volumes deﬁned between cathode foils,by means of holes drilled on opposite sides of theﬁbreglass frames.The design of module DC-1diﬀers from the one shown in Fig.17.The main diﬀerence,illustrated in Fig.18,consists in the fact that DC-1comprises,in a single gas volume,two sets of sensitive planes,placed symmetrically to the left and right hand side of the spectrometer axis.The middle zone,which is strongly irradiated by particles(mostly fast protons from target fragmenta-tion),is made insensitive to the particleﬂux.The limiting edge of the sensitivezones,close to the axis,can be varied.This is possible by means of a stripped structure of the neighbouring cathodes,which allows stepwise application of voltage.This design of the DC-1module ensures little amount of material,by avoiding frames in the small angle region.Fig.18.Schematic view of the DC-1module.Dotted areas show the sensitive regions of the X-,Y-and W-planes.Hatched areas mark the zones of the cathode strips which allow to change the width of the insensitive area in the central region.8.4Chamber operation and performanceThe drift chambers operate in a high current avalanche mode.This mode is characterised by high pulse amplitude(about1mA),small pulse width(20ns), and stable operation due to an eﬃciency plateau larger than1kV.The single hit eﬃciency is above96%when the particleﬂux is about10kHz/cm2.The employed gas mixture is Ar(∼50%)+iC4H10(∼50%)+H2O(0.5%),and the chamber operation voltage is3.85kV.A space-to-time relationship was extracted from the time spectrum and its integral distribution shown in Fig.19,for a sample of clean events with a small amount of background hits.The integral distribution has been parameterised by a second order polynomial of the type:l=a1×t⋆+a2×t⋆2.In this formula t⋆=t T DC−t0−δt,whereδt is the signal propagation time along the anode wire.Study of the drift function parameters for diﬀerent chamber planes at diﬀerent beam intensities shows good stability of the above relation.For this reason the。

Autodesk HSMWorks 2020.1 发布说明书

Autodesk® HSMWorks™ 2020.1Release NotesBuild 14.0.0.xxxxx / xx June 2019 Autodesk, Inc.CONTENTSThis document covers all three HSMWorks products:HSMXpressHSMWorks PremiumHSMWorks UltimateWhat’s NewSystem RequirementsInstallationWHAT’S NEWThe following changes have been made in the current update (2020.1):Milling ToolpathsImproved Adaptive for tighter model contours; it now finds a starting point on the stock boundary. (#12095)Improved start entries for Adaptive Clearing toolpaths so that the toolpath starts in corners/endpoints rather than in the middle of a stock line. (#12238)Fixed an issue where calculating a 2D Adaptive toolpath with rest machining from a face selection could result in a large area being machined. (#13030)Fixed an issue in Adaptive where using a ballnose cutter as a reference tool was giving the wrong toolpath. (#14000) Fixed an issue where preserve order was not respected in 2D Profile toolpaths. (#12127)Fixed an issue where 3D Adaptive Clearing with rest machining can fail with complex remaining stock. (#13622)Fixed several issues in which the toolpath computations for Adaptive Clearing could fail on Mac. (#12188)Fixed a problem in Contour toolpaths where ramps might not be connected to their cutting moves, resulting in an unexpected lift and plunge to cover the gap. (#13822)Fixed an issue that introduced unnecessary retracts in Ramp operations. (#13747)Fixed an issue which caused irregular cutting passes for Scallop toolpaths. (#13757)Fixed an issue where a Constant Scallop toolpath might not calculate when up/down milling and 'other-way' linking was enabled. (#13172)Removed the "Shoulder Length" and "Taper Angle" parameters from the Rest Machining dialog for 2D Adaptive. They are not applicable in this context. (#10594)Fixed a problem where retracting Z levels were machining areas that had already been cleared in lower levels. (#14035) Turning ToolpathsImplemented toolpath verification, simulation and NC code generation for general and boring turning tools when angled in the tool library or by using the tool orientation parameter in facing, profiling and chamfering operations (#14930)Fixed an issue where turn facing, profiling and chamfering operations with a right-facing angled tool with the angle specified either in the tool library setup or in the tool orientation section of the operation were simulating incorrectly as well as outputting incorrect NC code (#14785)Fixed an issue where a grooving operation could fail if the back and front Z limits coincided with the extents of the groove geometry. (#10978)Fixed a memory leak for some turning grooving jobs. (#13390)Tool LibraryFixed an issue where turning tools with boring holders were previewed incorrectly in the tool library and modeled incorrectly in simulation (#15116)Post ProcessorFunctionality has been restored to the alert, promptKey, and promptKey2 API calls. These now work as before, but are supported only on Windows. (#14452)Fixed a regression where tool.getExtent() could return an empty bounding box, causing the setup sheet to incorrectly scale the tool image. (#13848)Added a mechanism to define which rotary axes support TCP in the post processor. This simplifies the code needed to disable TCP for a single axis. (#13282)Added new global function 'isNewWorkPlane(section)' which returns true if the passed section requires new workplane calls. This simplifies the 'newWorkPlane' checks that are typically done inside of post processors (#13278)Added global variables 'minimumProgramNumber' and 'maximumProgramNumber' to post processor. (#13276)Post properties that you set when using a post processor are now saved to a file. This allows using the post processor on other computers with confidence that the previously used properties will continue to be applied. (#13233)Added the onManualNC function that will handle all Manual NC commands, and the expandManualNC function that handles all Manual NC commands using the historical method. (#12839)Fixed the behavior of mapToWCS, so that it can be changed multiple times in the post. (#12733)Added cancelRotation and cancelTranslation methods. (#8965)NC EditorUpdated HSMEdit to fix an issue in which the display of text was corrupted. (#14524)Updated HSMEdit to correct a problem with the backplotting function. (#14428)APIImprove the performance of API functions setObjectParameter and setObjectToolView by removing an unnecessary call to updateOperationManager. (#14467)LicensingFixed an issue in which administrator privileges were required when activating a license. (#14902)The following changes have been made in a previous update (2020):General ImprovementsFusion 360 subscribers may now run HSMWorks by authenticating with your Autodesk account. This requiresdownloading and installing HSMWorks from your Autodesk account. Look for this new version at the top level of'Products and Services', rather than the versions that are listed as part of the collection or part of 'Autodesk HSM'. (CAM-12164)The HSMEditor has been updated to the latest version for the 2020 release. (CAM-12417)A warning is now issued if you edit a machine configuration that is being used in multiple setups, since the changes youmake will affect all setups that reference the machine. (CAM-10281)Post Processor ImprovementsNew functions 'section.getModelOrigin' and 'section.getModelPlane' were added to provide access to the workcoordinate system of the CAD model. (CAM-12614)A 'reset' parameter has been added to the createAxis function, which can reset the current rotary axis position to zeroprior to scanning the section for the optimal rotary starting position. There are also corresponding 'axis.getReset' and 'axis.setReset' functions. (CAM-12300)A new variable 'machineParameter.spindleSpeedDwell' has been added which specifies a dwell time in seconds when thespindle speed changes during a drilling cycle. This can be used to correct expanded gun-drilling cycles. (CAM-9495)API ImprovementsA new HSMWorks_getObjectGeometry function provides access to the geometry set associated with an operation. (CAM-13613)A new HSMWorks_setObjectToolView function provides the ability to set the tool orientation for an object. (CAM-12988)A new HSMWorks_createObject function allows creation of Manual NC operations. (CAM-13678)Toolpath FixesWhen using a cutter with a corner radius in 2D Adaptive, the upper edge of a pocket could be gouged in somecircumstances; this is corrected. (CAM-11596)Allow machining two open bores within the same operation. (CAM-11647)Fixed an issue where the software could hang when calculating helical ramps on a contour pass. (CAM-12129)Fixed an issue in which toolpaths might not get created when using the "Fillet" option (Mac only). (CAM-12279)Fixed an issue in which helical links were detached from their cutting segment and a further lift and plunge was inserted in between to join them. (CAM-12364)Jet will now provide the user with a better warning when no path can be computed. (CAM-12953)Contour with Both Way and Roughing Passes used to produce partial toolpaths. This has now been fixed. (CAM-13309) Fixed an issue where some arcs were misformed when offset. (CAM-13135)Fixed an issue which could have caused gouges when smoothing for sampling strategies is enabled. (CAM-13266) Fixed an issue which caused irregular cutting passes for the scallop strategy. (CAM-13757)Turning FixesFixed leads when "Use fixed lead direction" was turned off for certain inside and face grooving operations. (CAM-10679)Post Processor FixesFixed an issue in which "getOptimizedTCPMode" was returning an incorrect value. (CAM-11367)A post processor error is no longer generated when a multi-axis operation has a constant tool axis of 0,0,1. (CAM-11794)The post processor now considers a drilling operation to be an axial center drilling operation instead of a millingoperation when it is within a tolerance of X=0, Y=0. (CAM-8185)Fixed a problem in which linear values from the machine configuration dialog were not recalculated according to the output units. (CAM-11877)Return to TopSYSTEM REQUIREMENTSAutodesk HSMWorks 2020 supports Microsoft Windows 7 64-bit and Windows 10 64-bit.。

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

Original ArticleA new MRI grading system forchondromalacia patellaeAli O¨zgen,Neslihan T a¸s delen and Zeynep FıratAbstractBackground:Chondromalacia patellae is a very common disorder.Although magnetic resonance imaging(MRI)is widely used to investigate patellar cartilage lesions,there is no descriptive MRI-based grading system for chondromalacia patellae. Purpose:T o propose a new MRI grading system for chondromalacia patellae with corresponding high resolution images which might be useful in precisely reporting and comparing knee examinations in routine daily practice and used in predicting natural course and clinical outcome of the patellar cartilage lesions.Material and Methods:High resolution fat-saturated proton density(FS PD)images in the axial plane with corres-ponding T2mapping images were reviewed.A detailed MRI grading system covering the deficiencies of the existing gradings has been set and presented on these images.T wo experienced observers blinded to clinical data examined44 knee MR images and evaluated patellar cartilage changes according to the proposed grading system.Inter-and intra-rater validity testing using kappa statistics were calculated.Results:A descriptive and detailed grading system with corresponding FS PD and T2mapping images has been pre-sented.Inter-rater agreement was0.80(95%confidence interval[CI],0.71–0.89).Intra-rater agreements were0.83(95% CI,0.74–0.91)for observer A and0.79(95%CI,0.70–0.88)for observer B(k-values).Conclusion:We present a new MRI grading system for chondromalacia patellae with corresponding images and good inter-and intra-rater agreement which might be useful in reporting and comparing knee MRI examinations in daily practice and may also have the potential for using more precisely predicting prognosis and clinical outcome of the patients.KeywordsPatella,cartilage diseases,magnetic resonance imaging(MRI)Date received:11March2016;accepted:9May2016IntroductionChondromalacia patellae is a very common disorder which is characterized by softening,swelling,fraying,ﬁssuring,and erosion of hyaline cartilage overlying the patella(1).Patellar chondromalacia could be observed as a cause of patellofemoral pain,as well as in patients with osteoarthritis,in patients with knee trauma,or even in asymptomatic patients.Patellar chondromala-cia could also be diagnosed in the vast majority of patients who underwent magnetic resonance imaging (MRI)examination of the knee regardless of clinical diagnosis.Although arthroscopy is generally con-sidered as the gold standard for making the diagnosis, with the currentﬁeld strength of MRI,developments in coil production,and software,MRI has become a powerful non-invasive tool to investigate patellar car-tilage lesions(2).MRI is also used for monitoring the eﬀects of therapies for cartilage lesions(3).Clinical grading of patellar chondromalacia goes back more thanﬁve decades.Outerbridgeﬁrst described a basic grading system for chondromalacia patellae based on surgicalﬁndings(1).This system has been widely used in its original or revised forms. In1989,Noyes introduced a new system for grading articular cartilage lesions based on arthroscopicﬁndings with a review of the previous literature(4).Noyes’system has also been used in clinical practice and has been modiﬁed for MRI classiﬁcation of chondral lesions Department of Radiology,Y editepe University Hospital,Istanbul,T urkeyCorresponding author:Ali Ozgen,Department of Radiology,Y editepe University Hospital,_Ic¸erenko¨y mahallesi,Hastane yolu sokak,No:102-104,Ata¸s ehir,34752, _Istanbul,T urkey.Email:draliozgen@Acta Radiologica0(0)1–8!The Foundation Acta Radiologica2016Reprints and permissions:/journalsPermissions.navDOI:10.1177/0284185116654332Acta Radiol OnlineFirst, published on June 20, 2016 as doi:10.1177/0284185116654332(5–9).More recently,the International Cartilage Research Society(ICRS)developed an arthroscopic cartilage injury grading system,which has largely super-seded the previous ones(10).These widely used systems are shown in Table1.There have also been some soli-tary,revised,or adapted systems from Noyes or ICRS classiﬁcations for MRI grading and some original or revised histological grading systems of cartilage damage used in clinical practice(11–14).Although there have been many classiﬁcations used for articular cartilage injury,we believe all these sys-tems have some deﬁciencies in describing and moni-toring all cartilage lesions based on the current knowledge.First,very early intracartilaginous lesions with intact articular surface have not been managed as a separate entity and classiﬁed accordingly considering the area involved.Second,all these existing clinical and imaging grading systems largely depend on depth of the chondral defect.All types of defects with the same depth or area,such asﬁssures,ﬂaps, andﬁbrillations,have been classiﬁed in the same grade as if they could be managed as a single entity and their natural course or response to any therapy would result in same outcome.Third,full thickness cartilage defects,with or without subchondral bony changes,have been classiﬁed in the same category. The objective of this study was to propose a new descriptive MRI grading system for chondromalacia patellae covering the deﬁciencies of the current sys-tems,which might be useful in reporting,comparing, and monitoring patellar chondral lesions.Material and MethodsThis study was approved by the institutional ethics rmed consent was obtained from all individual participants included in the study.PatientsForty-four knee MRI examinations of41adult con-secutive patients(20women,21men;mean age,42 years;age range,21–71years)were included in this study.Clinical diagnosis was patellar chondromalacia in21(51%),non-speciﬁc pain in nine(22%),menisco-pathy in eight(20%),and anterior cruciate ligament tear in three(7%)patients.Patellar cartilage of the patients was evaluated in FS PD images and corres-ponding T2mapping images in the axial plane as explained in the imaging section.Images of the patients with any kind of artifacts that would prevent optimum interpretation were not included in the study. ImagingAll images were obtained with a3.0T machine(Ingenia; Philips Medical Systems,Best,The Netherlands)using a 16-channel transmit/receive dedicated knee coil.FS PD images(TR2000/TE30)were obtained in the axial plane with two excitations.Slice thickness was2mm,reso-lution was0.4Â0.5mm except for Fig.12which had a resolution of0.3Â0.3mm.Field of view was80mm. Corresponding T2mapping sequence(TR2000/TE13, 26,39,52,65,78)were obtained with the same slice thick-ness,0.6Â0.6mm resolution,and with single excitation. In these images,the orange areas represent normal car-tilage whereas the yellow,green,and blue areas represent cartilage lesions with higher water content in that order. MRI gradingTable2shows the proposed MRI grading system for chondromalacia patellae.In this system,the number rep-resents the depth of the lesion,whereas the letter repre-sents type of the lesion,except for grade1lesions,whichT able1.Grading systems for articular cartilage lesions.Grade Outerbridge ICRS Modified Noyes 0Normal Normal Normal1Softening and swelling,intactsurface Nearly normal(soft indentationand/or superficial fissures andcracks)Increased T2signal intensity ofmorphologically normalcartilage2Fragmentation and fissuring ofarticular cartilage affecting anarea of less than0.5inches Abnormal(lesions extending to<50%of cartilage depth)A:Superficial partial-thicknesscartilage defect<50%of totalarticular surface thicknessB:Deep partial-thickness cartil-age defect>50%of totalarticular surface thickness3Fragmentation and fissuring ofarticular cartilage affecting anarea greater than0.5inches Severely abnormal(lesions extend-ing>50%of cartilage depth,butnot through subchondral bone)Full-thickness cartilage defect4Cartilage erosion to bone Lesions involving subchondral bone2Acta Radiologica0(0)letter represents depth of the lesion.Grade0represents normal cartilage(Fig.1).Grade1is reserved for isolated signal changes in the cartilage with an intact articular surface.Grade1A represents focal small signal change within the cartilage(Fig.2)that does not reach half of the cartilage thickness.Grade1B represents more than half but non-full thickness cartilage signal changes(Fig.3). Grade1C represents full thickness cartilage signal change with intact surface(Fig.4).Grade2is reserved for chondral lesions extending down <50%of the cartilage depth.Grade2A represents isolated ﬁssures orﬁbrillations(Fig.5),grade2B representsﬂaps (Fig.6),grade2C represents a crab-meat appearance,mul-tipleﬁssures,orﬁbrillations side by side(Fig.7),and grade 2D represents a diﬀuse cartilage volume loss,which width of the lesion is more than its depth.Grade3is reserved for chondral lesions extending down50%or more of the cartilage depth but not reaching the subchondral bone.Like grade2lesions,grade3A represents isolatedﬁssures orﬁbrillations, grade3B representsﬂaps(Fig.8),grade3C represents a crab-meat appearance(Fig.7),and grade3D repre-sents diﬀuse chondral volume loss(Fig.9).Grade4is reserved for full thickness cartilage defects. Grade4A represents a full thicknessﬁssure,grade4B represents a full thicknessﬂap(Fig.10),grade4C repre-sents a full thickness ulcer,and grade4D represents fullT able2.MRI grading of chondromalacia patellae.Grade0Normal cartilageGrade1Intracartilaginous signal changes with an intactarticular surface1A Small foci of signal changes,<50%of cartilagedepth1B Non-full thickness signal changes,!50%of car-tilage depth1C Full thickness signal changesGrade2Chondral lesions extending down<50%of car-tilage depth2A Fissure or fibrillation extending down<50%ofcartilage depth2B Flap extending down<50%of cartilage depth 2C Crab-meat lesion extending down<50%of car-tilage depth2D Diffuse volume loss of<50%of cartilage depth Grade3Chondral lesions extending down!50%of car-tilage depth3A Fissure or fibrillation extending down!50%ofcartilage depth3B Flap extending down!50%of cartilage depth 3C Crab-meat lesion extending down!50%of car-tilage depth3D Diffuse volume loss of!50%of cartilage depth Grade4Full thickness cartilage lesion4A Full thickness fissure4B Full thickness flap4C Full thickness ulcer4D Full thickness diffuse cartilage lossGrade5Any grade4lesion with subchondral fibrocysticbonychange Fig.1.T2mapping(up)and corresponding FS PD(down)images of a normal appearing patellar cartilage.Note uniform homogen-ous signal from the cartilage both in FS PD and T2mapping images. Relative thin appearance of medial aspect of the cartilage with green coding in T2mapping is caused by partial volumeartefact. Fig.2.T2mapping(up)and corresponding FS PD(down) images showing small foci of signal changes(arrows)representing grade1A lesions.O¨zgen et al.3thickness diﬀuse cartilage volume loss.Grade 5is reserved for any grade 4lesion with subchondral ﬁbro-cystic change in the underlying bone (Fig.11).Image reviewAll images were reviewed and graded by two radiologists blinded to the clinical data.Observer A was a generalradiologist with 16years of experience and observer B was a musculoskeletal radiologist with 10years of experi-ence.Final grading of patellar chondromalacia was made with mutual agreement.For each patella,medial facet,lateral facet,and junctional area were separately evaluated and graded.Therefore,each rater did perform 132gradings in 44knee examinations.Statistical analysisWe performed inter-and intra-rater validity testing using Cohen’s unweighted kappa statistics with SPSS 20soft-ware (SPSS Inc.,Chicago,IL,USA).To assess inter-rater agreement,two radiologists blinded to the clinical data examined 44knee MRI examinations of 41adult patients.To assess intra-rater agreement,observers A and B re-evaluated the same patients after at least a 3-week period.Kappa values were deﬁned based on Altman’s Kappa Benchmark Scale (Table 2).A Kappa value <0.20indicates a poor agreement level,a value of 0.21–0.40indicates a fair agreement level,a value of 0.41–0.60indicates a moderate agreement level,while ranges of values 0.61–0.80and 0.81–1.00indicate good and very good agreement levels,respectively (15).Results Grading resultsThere were 76grade 1lesions (58%),14grade 2lesions (11%),ﬁve grade 3lesions (4%),four grade 4lesions (3%),and nine grade 5lesions (7%)in 132separate areas of 44patellae examined.There was no patient whose patellar cartilage was interpreted as normal in allareas.Fig.3.T2mapping (up)and corresponding FS PD (down)images showing signal changes of articular cartilage (arrows)representing grade 1B lesions.Note there is swelling (arrowheads)of the car-tilage which could be noted by arthroscopy whereas the other lesion is located deeply and might not bedetected.Fig.4.T2mapping (up)and corresponding FS PD (down)images showing diffuse signal changes of articular cartilage (arrows)in the lateral facet representing grade 1C lesion.Note there is also a grade 1B lesion (arrowhead)in the medial facet of thepatellae.Fig.5.T2mapping (up)and corresponding FS PD (down)images showing a superficial fissure (arrow)representing grade 2A lesion.4Acta Radiologica 0(0)Inter-and intra-rater variabilityInter-rater agreement for grading was 0.80(95%conﬁ-dence interval [CI],0.71–0.89)(k-values with 95%CI in parentheses).Of 18disagreements,12of them were in between the same grade;seven for grade 1lesions,three for grade 2lesions,and two for grade 3lesion.There was no inter-rater disagreement in evaluating grade 4and 5lesions.Intra-rater agreements for grading were 0.83(95%CI,0.74–0.91)for observer A and 0.79(95%CI,0.70–0.88)for observer B (k-values with 95%CI in parenth-eses).Of 37total disagreements,18for observer A and 19for observer B,27were in between the same grade;19for grade 1lesions,ﬁve for grade 2lesions,and three for grade 3lesions.There was no intra-rater disagree-ment in evaluating grade 4and 5lesions.DiscussionIn this study,we propose a new and detailed MRI grad-ing system for chondromalacia patellae with correspond-ing high resolution FS PD and T2mapping images,which might be useful in reporting and comparing knee MRI examinations in routine daily practice.We also pre-sent good inter-rater and good to very good intra-rater agreements when using this system.Naturally,multiple lesions could be observed in the same patella and we sug-gest each lesion to be graded separately.Hyaline cartilage is divided into four somewhat arbi-trary zones (16,17).The superﬁcial zone makes up 3–12%of the cartilage thickness.The intermediate zone is thicker than the superﬁcial zone.The deep zone is the thickest and represents over 50%of the cartilage thickness.The zone of calciﬁed cartilage overlies the subchondral bone.However,with current MRI technology these zones are not well delineated even with very high resolution images in clinical practice (Fig.12).Therefore,the value of 50%of the cartilage depth has been generally considered a practical landmark in chondromalacia grading systems both arthroscopically and radiologically.Although many sequences have been used in MRI of the patellar cartilage and the optimal pulse sequenceisFig.7.T2mapping (up)and corresponding FS PD (down)images showing crab-meat appearance representing grade 2C lesion (arrowheads)and grade 3C (arrow)lesion.Fig.8.T2mapping (up)and corresponding FS PD (down)images showing a flap (arrow)reaching 50%of cartilage thickness representing grade 3Blesion.Fig.6.T2mapping (up)and corresponding FS PD (down)images showing a superficial flap (white arrow)representing grade 2B lesion which could be easily seen by arthroscopy.Note there is also a deep grade 1B lesion (black arrow)which might be undetected by visual inspection at arthroscopy.O¨zgen et al.5controversial,FS PD images have been considered very valuable to evaluate patellar cartilage with high spatial resolution and good contrast-to-noise ratio in a reason-able scan time (2,3).T2mapping,a sequence sensitive to T2prolongation induced by cartilage degeneration,has been considered as eﬀective in detecting very early patel-lar cartilage lesions although the technique is time con-suming and has lower resolution (2,3,6,17).We currently use these two sequences in our daily practice for imaging of the patellar cartilage.There have been researches for revealing optimum sequence in detecting cartilagedefects and for increasing the ability of MRI to detect very early patellar cartilage degeneration (5,6,18,19).Early signs of patellar cartilage degeneration may be observed as hyperintense areas within the cartilage in FS T2-weighted (T2W)or FS PD images (2,3).Since T2relaxation time is very sensitive to the integrity of colla-gen network,collagen content,and water content,these areas could be detected in T2mapping sequence to a greater extent (3,5,14,18,20,21).Although T2mapping is very sensitive in detecting cartilage lesions,due to its lower spatial resolution,type and depth of a lesion might not be well documented in comparison to FS PD images.There have been ongoing studies investigating this ﬁnd-ing as an early indicator of knee osteoarthritis (20,21).Extent of these very early changes could not be deter-mined in arthroscopy although some might be feltasFig.11.(a)FS PD image showing full thickness articular cartilage loss with subchondral changes (arrows),(b)FS PD image showing full thickness fissure with subchondral changes (arrows)repre-senting grade 5lesions.Fig.12.Very high resolution (0.3Â0.3mm)axial FS PD image of the patellae of a volunteer.Anatomic zones of the cartilage are not delineated in normal or chondromalacic appearing area of the articular hyalinecartilage.Fig.10.T2mapping (up)and corresponding FS PD (down)images showing a full thickness flap (arrow)representing grade 4Blesion.Fig.9.T2mapping (up)and corresponding FS PD (down)images showing a diffuse volume loss of more than 50%of articular cartilage (arrows)representing grade 3D lesion.6Acta Radiologica 0(0)softening in arthroscopic probing.On the other hand,in current MRI grading systems,any degree of intracarti-laginous signal change is classiﬁed as a grade1lesion. However,percentage of early cartilage degeneration may be relevant in natural outcome or response to any ther-apy(21).Therefore,further subclassifying thisﬁnding based on percentage of the cartilage depth,as proposed in this study,may be helpful in comparing MRI exam-inations,monitoring therapy,and natural prognosis.Current clinical and MRI grading systems for mild to moderate patellar chondromalacia are based on only depth of the chondral defect.Studies investigating nat-ural course of the patellar chondromalacia and out-comes of diﬀerent therapeutic approaches have been based on these basic gradings(13,14,22).Although most of the cartilage lesions remain in the same grade over a certain period of time or progress to a higher grade,natural course and response to various thera-peutic approaches of mild and moderate patellar cartil-age lesions based on current grading systems could not be well predicted(13,14).We believe that lack of spe-ciﬁc deﬁnition of the chondral lesions in current grad-ing systems may at least be one of the reasons not being able to exactly predict the prognosis.Type of the chon-dral lesion,which has been generally ignored in grad-ing,might play a role in natural prognosis or response to any treatment as well as depth of the lesion might. For example,a chondralﬁssure might result in a diﬀer-ent outcome than a chondralﬂap or defect with the same depth.Therefore,subclassifying patellar cartilage defects may enable us to make a more deﬁnitive diag-nosis of patellar chondral lesions,and more precisely predict prognosis and clinical outcome of the patients. Likewise,full thickness cartilage defects with or with-out subchondral bony changes are generally classiﬁed in the same grade.However,presence or absence of subchondralﬁbrocystic changes may have an impact on response to any therapeutic interventional approach (23).Therefore,separating these full thickness defects into diﬀerent grades might also help us more precisely classifying and monitoring these lesions.Inter-and intra-observer reliability is a main feature of any grading system.Previous studies regarding reproducibility of MRI in detecting cartilage lesions revealed moderate to good degree of agreement (5,6,14,19,20).In comparison with the studies about reproducibility of the arthroscopical grading of chon-dral lesions,MRI based gradings result in better inter-and intra-observer reliability(24–26).In this study,we present good inter-rater and good to very good intra-rater reliability in grading cartilage lesions based on the proposed e of high resolution images might have helped in reaching a high degree of inter-and intra-observer agreement.Getting used to this grading system may also further increase reliability.There are several limitations of this study.Although, MRI is the best imaging method currently available for articular cartilage lesions and may also provide some biochemical information about the cartilage,arthros-copy is generally considered as the gold standard for making the diagnosis of patellar chondromalacia. Therefore,the main limitation of this study seems to be the lack of speciﬁc arthroscopical veriﬁcation of MRI ﬁndings using this system.However,it is questionable for us that arthroscopy was superior to MRI in detecting and classifying all chondral lesions.Macroscopic appear-ance of the articular cartilage is evaluated in arthroscopy but it is insensitive to intrinsic degeneration that is not visible at the articular surface(21).Grade1A and1B lesions,as presented in this study,might not be detected by arthroscopic probing unless they were located super-ﬁcially.Deeply located grade1A and1B lesions may rep-resent grossly normal appearing patellar cartilage with histological degeneration those naturally have not been included in arthroscopy-based gradings(11,14,21). Therefore,arthroscopic grade0may not represent healthy cartilage and T2mapping may be more valuable in the detection of very early cartilage degeneration.We believe that proper classiﬁcation of grade1lesions could be possible only by MRI and by histological examination as the reference gold standard.Grade2–4lesions are very well detected by arthroscopy while MRI has also been proven to be accurate in detecting such lesions (5,6,14,20).Although grade2and3lesions are easily detected by arthroscopic examination,since the actual thickness of the cartilage could not be detected by arth-roscopy in some patients and grading depends on the percentage of depth of the lesion,there might be some challenge in diﬀerentiating grade2lesions from grade3 lesions solely by arthroscopy.High resolution MR images might provide a better diﬀerentiation between these lesions.Meanwhile,extent and nature of subchon-dral changes observed in grade5lesions could be better delineated with MRI than with arthroscopy.Therefore, superiority of arthroscopy over MRI in detecting and classifying all patellar chondral lesions might be ques-tioned.We believe main limitation of this study is the lack of histological examination as the reference gold standard.Spatial resolution of T2mapping in this study is relatively low due to its nature.However,a T2 mapping sequence with equally high resolution would last approximately20min and would not be practical in routine daily imaging.This study also lacks T1rho imaging which is also a sensitive method in detecting early cartilage changes(3).The limited number of patients evaluated in assessing reliability and reproduci-bility of this system and lack of correlation with physical examination are also limitations of the study.Further studies with large number of subjects veriﬁed with arth-roscopy or preferably with histological examinationsO¨zgen et al.7would be needed to investigate the reliability of the pro-posed grading system,its clinical relevance,and its ability to predict prognosis.In conclusion,we present an MRI grading system for chondromalacia patellae with corresponding images which might be useful in reporting and compar-ing knee MRI examinations in routine daily practice and may also have the potential for using more pre-cisely predicting prognosis and clinical outcome of the patients.Main diﬀerences of this grading that sets apart from the current clinical and MRI-based systems are its descriptive nature,distinct separation and subclassiﬁca-tion of cartilage lesions.Declaration of Conflicting InterestsThe authors declared no potential conﬂicts of interest with respect to the research,authorship,and/or publication of this article.FundingThe authors received noﬁnancial support for the research, authorship,and/or publication of this article.References1.Outerbridge RE.The etiology of chondromalacia patellae.J Bone Joint Surg1961;43:752–757.2.Gold GE,Chen CA,Koo S,et al.Recent advances inMRI of articular cartilage.Am J Roentgenol2009;193: 628–638.3.Crema MD,Roemer FW,Marra MD,et al.Articular car-tilage in the knee:current MR imaging techniques and applications in clinical practice and research.Radiographics2011;31:37–62.4.Noyes FR,Stabler CL.A system for grading articular car-tilage lesions at arthroscopy.Am J Sports Med1989;17: 505–513.5.Kijowski R,Blankenbaker DG,Munoz Del Rio A,et al.Evaluation of the articular cartilage of the knee joint: value of adding a T2mapping sequence to a routine MR imaging protocol.Radiology2013;267:503–513.ewski MD,Smitaman E,Moukaddam H,et al.Comparison of3D vs.2D fast spin echo imaging for evalu-ation of articular cartilage in the knee on a3T system scientific research.Eur J Radiol2012;81:1637–1643.7.Recht MP,Piraino DW,Paletta GA,et al.Accuracy offat-suppressed three-dimensional spoiled gradient-echo FLASH MR imaging in the detection of patellofemoral articular cartilage abnormalities.Radiology1996;198: 209–212.8.Ding C,Cicuttini F,Scott F,et al.Natural history of kneecartilage defects and factors affecting change.Arch Intern Med2006;166:651–658.9.Carnes J,Stannus O,Cicuttini F,et al.Knee cartilagedefects in a simple of older adults:natural history,clinical significance and factors influencing change over2.9years.Osteoarthritis Cartilage2012;20:1541–1547.10.Brittberg M,Winalski CS.Evaluation of cartilage injuriesand repair.J Bone Joint Surg Am2003;85(Suppl.2):58–69.11.Athiviraham A,Fechisin J,Hartman A,et al.The normalpatella-does it exist?a histologic analysis.Am J Orthop (Belle Mead NJ)2014;43:370–373.12.Pauli C,Whiteside R,Heras FL,et parison ofcartilage histopathology assessment systems on human knee joints at all stages of osteoarthritis development.Osteoarthritis Cartilage2012;20:476–485.13.Mattila VM,Weckstro m M,Leppa nen V,et al.Sensitivity of MRI for articular cartilage lesions of the patellae.Scand J Surg2012;101:56–61.14.Dautry R,Bousson V,Manelfe J,et al.Correlation ofMRI T2mapping sequence with knee pain location in young patients with normal standard MRI.JBR-BTR 2014;97:11–61.15.Altman DG.Practical statistics for medical research.London:Chapman&Hill,1991.16.Shindle MK,Foo LF,Kelly BT,et al.Magnetic reson-ance imaging of cartilage in the athlete:current tech-niques and spectrum of disease.J Bone Joint Surg Am 2006;88(Suppl.4):27–46.17.Waldschmidt JG,Rilling RJ,Kajdacsy-Balla AA,et al.In vitro and in vivo MR imaging of hyaline cartilage: zonal anatomy,imaging pitfalls,and pathologic condi-tions.Radiographics1997;17:1387–1402.18.Xu J,Xie G,Di Y,et al.Value of T2-mapping and DWIin the diagnosis of early knee cartilage injury.J Radiol Case Rep2011;5:13–18.19.Kim HJ,Lee SH,Kang CH,et al.Evaluation of thechondromalacia patella using a microscopy coil:compari-son of the two-dimensional fast spin echo techniques and the three-dimensional fast field echo techniques.Korean J Radiol2011;12:78–88.20.Wang Y,Wluka AE,Jones G,et e of magneticresonance imaging to assess articular cartilage.Ther Adv Musculoskelet Dis2012;4:77–97.21.Casula V,Hirvasniemi J,Lehenkari P,et al.Associationbetween quantitative MRI and ICRS arthroscopic grad-ing of articular cartilage.Knee Surg Sports Traumatol Arthrosc2016;24:2046–2054.22.Biswal S,Hastie T,Andriacchi TP,et al.Risk factors forprogressive cartilage loss in the knee:a longitudinal mag-netic resonance imaging study in forty-three patients.Arthritis Rheum2002;46:2884–2892.23.Gomoll AH,Madry H,Knutsen G,et al.The subchon-dral bone in articular cartilage repair:current problems in the surgical management.Knee Surg Sports Traumatol Arthrosc2010;18:434–447.smar NP,Lasmar RCP,Vieira RB,et al.Assessmentof the reproducibility of the Outerbridge and FSA for chondral lesions of the knee.Rev Bras Ortop2011;46: 266–269.25.Brismar BH,Wredmark T,Movin T,et al.Observer reli-ability in the arthroscopic classification of osteoarthritis of the knee.J Bone Joint Surg2002;84:42–47.26.Cameron ML,Briggs KK,Steadman JR.Reproducibilityand reliability of the Outerbridge classification for grad-ing chondral lesions of the knee arthroscopically.Am J Sports Med2003;31:83–86.8Acta Radiologica0(0)。