A machine-independent port of the SR language run-time system to the NetBSD operating syste

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Unit+3+单词详解课件-2022-2023学年高中英语牛津译林版(2020)选择性必修第四册

XB3 Careers and skills
文章单词及其讲解
Welcome to the unit & Reading
1.salary n.薪金，薪水
2. labor vt.劳工；劳动，（尤指）体力劳动；分娩期，分娩vi. 努力做；干苦力活 manual force 体力劳动
labour force （全公司或全国的）劳动力 labourer n 劳动者
Through the work we do,our goals can be attained and our dreams achieved.All of us have had dreams of one kind or another and work often enables us to pursue those dreams.Henry David Thoreau said,“..if one advances confidently in the direction of his dreams,and endeavors to live the life which he has imagined,he will meet with a success unexpected in common hours.”
The magazine article below (P30) discusses some of the important reasons why we work.
Read for main idea (para1)
Read the magazine article and complete the chart below with the main idea of each paragraph.

人工智能英文文献原文及译文

附件四英文文献原文Artificial Intelligence"Artificial intelligence" is a word was originally Dartmouth in 1956 to put forward. From then on, researchers have developed many theories and principles, the concept of artificial intelligence is also expands. Artificial intelligence is a challenging job of science, the person must know computer knowledge, psychology and philosophy. Artificial intelligence is included a wide range of science, it is composed of different fields, such as machine learning, computer vision, etc, on the whole, the research on artificial intelligence is one of the main goals of the machine can do some usually need to perform complex human intelligence. But in different times and different people in the "complex" understanding is different. Such as heavy science and engineering calculation was supposed to be the brain to undertake, now computer can not only complete this calculation, and faster than the human brain can more accurately, and thus the people no longer put this calculation is regarded as "the need to perform complex human intelligence, complex tasks" work is defined as the development of The Times and the progress of technology, artificial intelligence is the science of specific target and nature as The Times change and development. On the one hand it continues to gain new progress on the one hand, and turning to more meaningful, the more difficult the target. Current can be used to study the main material of artificial intelligence and artificial intelligence technology to realize the machine is a computer, the development history of artificial intelligence is computer science and technology and the development together. Besides the computer science and artificial intelligence also involves information, cybernetics, automation, bionics, biology, psychology, logic, linguistics, medicine and philosophy and multi-discipline. Artificial intelligence research include: knowledge representation, automatic reasoning and search method, machine learning and knowledge acquisition and processing of knowledge system, natural language processing, computer vision, intelligent robot, automatic program design, etc.Practical application of machine vision: fingerprint identification,face recognition, retina identification, iris identification, palm, expert system, intelligent identification, search, theorem proving game, automatic programming, and aerospace applications.Artificial intelligence is a subject categories, belong to the door edge discipline of natural science and social science.Involving scientific philosophy and cognitive science, mathematics, neurophysiological, psychology, computer science, information theory, cybernetics, not qualitative theory, bionics.The research category of natural language processing, knowledge representation, intelligent search, reasoning, planning, machine learning, knowledge acquisition, combined scheduling problem, perception, pattern recognition, logic design program, soft calculation, inaccurate and uncertainty, the management of artificial life, neural network, and complex system, human thinking mode of genetic algorithm.Applications of intelligent control, robotics, language and image understanding, genetic programming robot factory.Safety problemsArtificial intelligence is currently in the study, but some scholars think that letting computers have IQ is very dangerous, it may be against humanity. The hidden danger in many movie happened.The definition of artificial intelligenceDefinition of artificial intelligence can be divided into two parts, namely "artificial" or "intelligent". "Artificial" better understanding, also is controversial. Sometimes we will consider what people can make, or people have high degree of intelligence to create artificial intelligence, etc. But generally speaking, "artificial system" is usually significance of artificial system.What is the "smart", with many problems. This involves other such as consciousness, ego, thinking (including the unconscious thoughts etc. People only know of intelligence is one intelligent, this is the universal view of our own. But we are very limited understanding of the intelligence of the intelligent people constitute elements are necessary to find, so it is difficult to define what is "artificial" manufacturing "intelligent". So the artificial intelligence research often involved in the study of intelligent itself. Other about animal or other artificial intelligence system is widely considered to be related to the study of artificial intelligence.Artificial intelligence is currently in the computer field, the moreextensive attention. And in the robot, economic and political decisions, control system, simulation system application. In other areas, it also played an indispensable role.The famous American Stanford university professor nelson artificial intelligence research center of artificial intelligence under such a definition: "artificial intelligence about the knowledge of the subject is and how to represent knowledge -- how to gain knowledge and use of scientific knowledge. But another American MIT professor Winston thought: "artificial intelligence is how to make the computer to do what only can do intelligent work." These comments reflect the artificial intelligence discipline basic ideas and basic content. Namely artificial intelligence is the study of human intelligence activities, has certain law, research of artificial intelligence system, how to make the computer to complete before the intelligence needs to do work, also is to study how the application of computer hardware and software to simulate human some intelligent behavior of the basic theory, methods and techniques.Artificial intelligence is a branch of computer science, since the 1970s, known as one of the three technologies (space technology, energy technology, artificial intelligence). Also considered the 21st century (genetic engineering, nano science, artificial intelligence) is one of the three technologies. It is nearly three years it has been developed rapidly, and in many fields are widely applied, and have made great achievements, artificial intelligence has gradually become an independent branch, both in theory and practice are already becomes a system. Its research results are gradually integrated into people's lives, and create more happiness for mankind.Artificial intelligence is that the computer simulation research of some thinking process and intelligent behavior (such as study, reasoning, thinking, planning, etc.), including computer to realize intelligent principle, make similar to that of human intelligence, computer can achieve higher level of computer application. Artificial intelligence will involve the computer science, philosophy and linguistics, psychology, etc. That was almost natural science and social science disciplines, the scope of all already far beyond the scope of computer science and artificial intelligence and thinking science is the relationship between theory and practice, artificial intelligence is in the mode of thinking science technology application level, is one of its application. From the view of thinking, artificial intelligence is not limited to logicalthinking, want to consider the thinking in image, the inspiration of thought of artificial intelligence can promote the development of the breakthrough, mathematics are often thought of as a variety of basic science, mathematics and language, thought into fields, artificial intelligence subject also must not use mathematical tool, mathematical logic, the fuzzy mathematics in standard etc, mathematics into the scope of artificial intelligence discipline, they will promote each other and develop faster.A brief history of artificial intelligenceArtificial intelligence can be traced back to ancient Egypt's legend, but with 1941, since the development of computer technology has finally can create machine intelligence, "artificial intelligence" is a word in 1956 was first proposed, Dartmouth learned since then, researchers have developed many theories and principles, the concept of artificial intelligence, it expands and not in the long history of the development of artificial intelligence, the slower than expected, but has been in advance, from 40 years ago, now appears to have many AI programs, and they also affected the development of other technologies. The emergence of AI programs, creating immeasurable wealth for the community, promoting the development of human civilization.The computer era1941 an invention that information storage and handling all aspects of the revolution happened. This also appeared in the U.S. and Germany's invention is the first electronic computer. Take a few big pack of air conditioning room, the programmer's nightmare: just run a program for thousands of lines to set the 1949. After improvement can be stored procedure computer programs that make it easier to input, and the development of the theory of computer science, and ultimately computer ai. This in electronic computer processing methods of data, for the invention of artificial intelligence could provide a kind of media.The beginning of AIAlthough the computer AI provides necessary for technical basis, but until the early 1950s, people noticed between machine and human intelligence. Norbert Wiener is the study of the theory of American feedback. Most familiar feedback control example is the thermostat. It will be collected room temperature and hope, and reaction temperature compared to open or close small heater, thus controlling environmental temperature. The importance of the study lies in the feedback loop Wiener:all theoretically the intelligence activities are a result of feedback mechanism and feedback mechanism is. Can use machine. The findings of the simulation of early development of AI.1955, Simon and end Newell called "a logical experts" program. This program is considered by many to be the first AI programs. It will each problem is expressed as a tree, then choose the model may be correct conclusion that a problem to solve. "logic" to the public and the AI expert research field effect makes it AI developing an important milestone in 1956, is considered to be the father of artificial intelligence of John McCarthy organized a society, will be a lot of interest machine intelligence experts and scholars together for a month. He asked them to Vermont Dartmouth in "artificial intelligence research in summer." since then, this area was named "artificial intelligence" although Dartmouth learn not very successful, but it was the founder of the centralized and AI AI research for later laid a foundation.After the meeting of Dartmouth, AI research started seven years. Although the rapid development of field haven't define some of the ideas, meeting has been reconsidered and Carnegie Mellon university. And MIT began to build AI research center is confronted with new challenges. Research needs to establish the: more effective to solve the problem of the system, such as "logic" in reducing search; expert There is the establishment of the system can be self learning.In 1957, "a new program general problem-solving machine" first version was tested. This program is by the same logic "experts" group development. The GPS expanded Wiener feedback principle, can solve many common problem. Two years later, IBM has established a grind investigate group Herbert AI. Gelerneter spent three years to make a geometric theorem of solutions of the program. This achievement was a sensation.When more and more programs, McCarthy busy emerge in the history of an AI. 1958 McCarthy announced his new fruit: LISP until today still LISP language. In. "" mean" LISP list processing ", it quickly adopted for most AI developers.In 1963 MIT from the United States government got a pen is 22millions dollars funding for research funding. The machine auxiliary recognition from the defense advanced research program, have guaranteed in the technological progress on this plan ahead of the Soviet union. Attracted worldwide computer scientists, accelerate the pace of development of AI research.Large programAfter years of program. It appeared a famous called "SHRDLU." SHRDLU "is" the tiny part of the world "project, including the world (for example, only limited quantity of geometrical form of research and programming). In the MIT leadership of Minsky Marvin by researchers found, facing the object, the small computer programs can solve the problem space and logic. Other as in the late 1960's STUDENT", "can solve algebraic problems," SIR "can understand the simple English sentence. These procedures for handling the language understanding and logic.In the 1970s another expert system. An expert system is a intelligent computer program system, and its internal contains a lot of certain areas of experience and knowledge with expert level, can use the human experts' knowledge and methods to solve the problems to deal with this problem domain. That is, the expert system is a specialized knowledge and experience of the program system. Progress is the expert system could predict under certain conditions, the probability of a solution for the computer already has. Great capacity, expert systems possible from the data of expert system. It is widely used in the market. Ten years, expert system used in stock, advance help doctors diagnose diseases, and determine the position of mineral instructions miners. All of this because of expert system of law and information storage capacity and become possible.In the 1970s, a new method was used for many developing, famous as AI Minsky tectonic theory put forward David Marr. Another new theory of machine vision square, for example, how a pair of image by shadow, shape, color, texture and basic information border. Through the analysis of these images distinguish letter, can infer what might be the image in the same period. PROLOGE result is another language, in 1972. In the 1980s, the more rapid progress during the AI, and more to go into business. 1986, the AI related software and hardware sales $4.25 billion dollars. Expert system for its utility, especially by demand. Like digital electric company with such company XCON expert system for the VAX mainframe programming. Dupont, general motors and Boeing has lots of dependence of expert system for computer expert. Some production expert system of manufacture software auxiliary, such as Teknowledge and Intellicorp established. In order to find and correct the mistakes, existing expert system and some other experts system was designed，such as teach users learn TVC expert system of the operating system.From the lab to daily lifePeople began to feel the computer technique and artificial intelligence. No influence of computer technology belong to a group of researchers in the lab. Personal computers and computer technology to numerous technical magazine now before a people. Like the United States artificial intelligence association foundation. Because of the need to develop, AI had a private company researchers into the boom. More than 150 a DEC (it employs more than 700 employees engaged in AI research) that have spent 10 billion dollars in internal AI team.Some other AI areas in the 1980s to enter the market. One is the machine vision Marr and achievements of Minsky. Now use the camera and production, quality control computer. Although still very humble, these systems have been able to distinguish the objects and through the different shape. Until 1985 America has more than 100 companies producing machine vision systems, sales were us $8 million.But the 1980s to AI and industrial all is not a good year for years. 1986-87 AI system requirements, the loss of industry nearly five hundred million dollars. Teknowledge like Intellicorp and two loss of more than $6 million, about one-third of the profits of the huge losses forced many research funding cuts the guide led. Another disappointing is the defense advanced research programme support of so-called "intelligent" this project truck purpose is to develop a can finish the task in many battlefield robot. Since the defects and successful hopeless, Pentagon stopped project funding.Despite these setbacks, AI is still in development of new technology slowly. In Japan were developed in the United States, such as the fuzzy logic, it can never determine the conditions of decision making, And neural network, regarded as the possible approaches to realizing artificial intelligence. Anyhow, the eighties was introduced into the market, the AI and shows the practical value. Sure, it will be the key to the 21st century. "artificial intelligence technology acceptance inspection in desert storm" action of military intelligence test equipment through war. Artificial intelligence technology is used to display the missile system and warning and other advanced weapons. AI technology has also entered family. Intelligent computer increase attracting public interest. The emergence of network game, enriching people's life.Some of the main Macintosh and IBM for application software such as voice and character recognition has can buy, Using fuzzy logic,AI technology to simplify the camera equipment. The artificial intelligence technology related to promote greater demand for new progress appear constantly. In a word ，Artificial intelligence has and will continue to inevitably changed our life.附件三英文文献译文人工智能“人工智能”一词最初是在1956 年Dartmouth在学会上提出来的。

现代操作系统(第三版)答案

MODERNOPERATINGSYSTEMSTHIRD EDITION PROBLEM SOLUTIONSANDREW S.TANENBAUMVrije UniversiteitAmsterdam,The NetherlandsPRENTICE HALLUPPER SADDLE RIVER,NJ07458Copyright Pearson Education,Inc.2008SOLUTIONS TO CHAPTER1PROBLEMS1.Multiprogramming is the rapid switching of the CPU between multiple proc-esses in memory.It is commonly used to keep the CPU busy while one or more processes are doing I/O.2.Input spooling is the technique of reading in jobs,for example,from cards,onto the disk,so that when the currently executing processes areﬁnished, there will be work waiting for the CPU.Output spooling consists ofﬁrst copying printableﬁles to disk before printing them,rather than printing di-rectly as the output is generated.Input spooling on a personal computer is not very likely,but output spooling is.3.The prime reason for multiprogramming is to give the CPU something to dowhile waiting for I/O to complete.If there is no DMA,the CPU is fully occu-pied doing I/O,so there is nothing to be gained(at least in terms of CPU utili-zation)by multiprogramming.No matter how much I/O a program does,the CPU will be100%busy.This of course assumes the major delay is the wait while data are copied.A CPU could do other work if the I/O were slow for other reasons(arriving on a serial line,for instance).4.It is still alive.For example,Intel makes Pentium I,II,and III,and4CPUswith a variety of different properties including speed and power consumption.All of these machines are architecturally compatible.They differ only in price and performance,which is the essence of the family idea.5.A25×80character monochrome text screen requires a2000-byte buffer.The1024×768pixel24-bit color bitmap requires2,359,296bytes.In1980these two options would have cost$10and$11,520,respectively.For current prices,check on how much RAM currently costs,probably less than$1/MB.6.Consider fairness and real time.Fairness requires that each process be allo-cated its resources in a fair way,with no process getting more than its fair share.On the other hand,real time requires that resources be allocated based on the times when different processes must complete their execution.A real-time process may get a disproportionate share of the resources.7.Choices(a),(c),and(d)should be restricted to kernel mode.8.It may take20,25or30msec to complete the execution of these programsdepending on how the operating system schedules them.If P0and P1are scheduled on the same CPU and P2is scheduled on the other CPU,it will take20mses.If P0and P2are scheduled on the same CPU and P1is scheduled on the other CPU,it will take25msec.If P1and P2are scheduled on the same CPU and P0is scheduled on the other CPU,it will take30msec.If all three are on the same CPU,it will take35msec.2PROBLEM SOLUTIONS FOR CHAPTER19.Every nanosecond one instruction emerges from the pipeline.This means themachine is executing1billion instructions per second.It does not matter at all how many stages the pipeline has.A10-stage pipeline with1nsec per stage would also execute1billion instructions per second.All that matters is how often aﬁnished instruction pops out the end of the pipeline.10.Average access time=0.95×2nsec(word is cache)+0.05×0.99×10nsec(word is in RAM,but not in cache)+0.05×0.01×10,000,000nsec(word on disk only)=5002.395nsec=5.002395μsec11.The manuscript contains80×50×700=2.8million characters.This is,ofcourse,impossible toﬁt into the registers of any currently available CPU and is too big for a1-MB cache,but if such hardware were available,the manuscript could be scanned in2.8msec from the registers or5.8msec from the cache.There are approximately27001024-byte blocks of data,so scan-ning from the disk would require about27seconds,and from tape2minutes7 seconds.Of course,these times are just to read the data.Processing and rewriting the data would increase the time.12.Maybe.If the caller gets control back and immediately overwrites the data,when the writeﬁnally occurs,the wrong data will be written.However,if the driverﬁrst copies the data to a private buffer before returning,then the caller can be allowed to continue immediately.Another possibility is to allow the caller to continue and give it a signal when the buffer may be reused,but this is tricky and error prone.13.A trap instruction switches the execution mode of a CPU from the user modeto the kernel mode.This instruction allows a user program to invoke func-tions in the operating system kernel.14.A trap is caused by the program and is synchronous with it.If the program isrun again and again,the trap will always occur at exactly the same position in the instruction stream.An interrupt is caused by an external event and its timing is not reproducible.15.The process table is needed to store the state of a process that is currentlysuspended,either ready or blocked.It is not needed in a single process sys-tem because the single process is never suspended.16.Mounting aﬁle system makes anyﬁles already in the mount point directoryinaccessible,so mount points are normally empty.However,a system admin-istrator might want to copy some of the most importantﬁles normally located in the mounted directory to the mount point so they could be found in their normal path in an emergency when the mounted device was being repaired.PROBLEM SOLUTIONS FOR CHAPTER13 17.A system call allows a user process to access and execute operating systemfunctions inside the er programs use system calls to invoke operat-ing system services.18.Fork can fail if there are no free slots left in the process table(and possibly ifthere is no memory or swap space left).Exec can fail if theﬁle name given does not exist or is not a valid executableﬁle.Unlink can fail if theﬁle to be unlinked does not exist or the calling process does not have the authority to unlink it.19.If the call fails,for example because fd is incorrect,it can return−1.It canalso fail because the disk is full and it is not possible to write the number of bytes requested.On a correct termination,it always returns nbytes.20.It contains the bytes:1,5,9,2.21.Time to retrieve theﬁle=1*50ms(Time to move the arm over track#50)+5ms(Time for theﬁrst sector to rotate under the head)+10/100*1000ms(Read10MB)=155ms22.Block specialﬁles consist of numbered blocks,each of which can be read orwritten independently of all the other ones.It is possible to seek to any block and start reading or writing.This is not possible with character specialﬁles.23.System calls do not really have names,other than in a documentation sense.When the library procedure read traps to the kernel,it puts the number of the system call in a register or on the stack.This number is used to index into a table.There is really no name used anywhere.On the other hand,the name of the library procedure is very important,since that is what appears in the program.24.Yes it can,especially if the kernel is a message-passing system.25.As far as program logic is concerned it does not matter whether a call to a li-brary procedure results in a system call.But if performance is an issue,if a task can be accomplished without a system call the program will run faster.Every system call involves overhead time in switching from the user context to the kernel context.Furthermore,on a multiuser system the operating sys-tem may schedule another process to run when a system call completes, further slowing the progress in real time of a calling process.26.Several UNIX calls have no counterpart in the Win32API:Link:a Win32program cannot refer to aﬁle by an alternative name or see it in more than one directory.Also,attempting to create a link is a convenient way to test for and create a lock on aﬁle.4PROBLEM SOLUTIONS FOR CHAPTER1Mount and umount:a Windows program cannot make assumptions about standard path names because on systems with multiple disk drives the drive name part of the path may be different.Chmod:Windows uses access control listsKill:Windows programmers cannot kill a misbehaving program that is not cooperating.27.Every system architecture has its own set of instructions that it can execute.Thus a Pentium cannot execute SPARC programs and a SPARC cannot exe-cute Pentium programs.Also,different architectures differ in bus architecture used(such as VME,ISA,PCI,MCA,SBus,...)as well as the word size of the CPU(usually32or64bit).Because of these differences in hardware,it is not feasible to build an operating system that is completely portable.A highly portable operating system will consist of two high-level layers---a machine-dependent layer and a machine independent layer.The machine-dependent layer addresses the specifics of the hardware,and must be implemented sepa-rately for every architecture.This layer provides a uniform interface on which the machine-independent layer is built.The machine-independent layer has to be implemented only once.To be highly portable,the size of the machine-dependent layer must be kept as small as possible.28.Separation of policy and mechanism allows OS designers to implement asmall number of basic primitives in the kernel.These primitives are sim-pliﬁed,because they are not dependent of any specific policy.They can then be used to implement more complex mechanisms and policies at the user level.29.The conversions are straightforward:(a)A micro year is10−6×365×24×3600=31.536sec.(b)1000meters or1km.(c)There are240bytes,which is1,099,511,627,776bytes.(d)It is6×1024kg.SOLUTIONS TO CHAPTER2PROBLEMS1.The transition from blocked to running is conceivable.Suppose that a processis blocked on I/O and the I/Oﬁnishes.If the CPU is otherwise idle,the proc-ess could go directly from blocked to running.The other missing transition, from ready to blocked,is impossible.A ready process cannot do I/O or any-thing else that might block it.Only a running process can block.PROBLEM SOLUTIONS FOR CHAPTER25 2.You could have a register containing a pointer to the current process tableentry.When I/O completed,the CPU would store the current machine state in the current process table entry.Then it would go to the interrupt vector for the interrupting device and fetch a pointer to another process table entry(the ser-vice procedure).This process would then be started up.3.Generally,high-level languages do not allow the kind of access to CPU hard-ware that is required.For instance,an interrupt handler may be required to enable and disable the interrupt servicing a particular device,or to manipulate data within a process’stack area.Also,interrupt service routines must exe-cute as rapidly as possible.4.There are several reasons for using a separate stack for the kernel.Two ofthem are as follows.First,you do not want the operating system to crash be-cause a poorly written user program does not allow for enough stack space.Second,if the kernel leaves stack data in a user program’s memory space upon return from a system call,a malicious user might be able to use this data toﬁnd out information about other processes.5.If each job has50%I/O wait,then it will take20minutes to complete in theabsence of competition.If run sequentially,the second one willﬁnish40 minutes after theﬁrst one starts.With two jobs,the approximate CPU utiliza-tion is1−0.52.Thus each one gets0.375CPU minute per minute of real time.To accumulate10minutes of CPU time,a job must run for10/0.375 minutes,or about26.67minutes.Thus running sequentially the jobsﬁnish after40minutes,but running in parallel theyﬁnish after26.67minutes.6.It would be difﬁcult,if not impossible,to keep theﬁle system consistent.Sup-pose that a client process sends a request to server process1to update aﬁle.This process updates the cache entry in its memory.Shortly thereafter,anoth-er client process sends a request to server2to read thatﬁle.Unfortunately,if theﬁle is also cached there,server2,in its innocence,will return obsolete data.If theﬁrst process writes theﬁle through to the disk after caching it, and server2checks the disk on every read to see if its cached copy is up-to-date,the system can be made to work,but it is precisely all these disk ac-cesses that the caching system is trying to avoid.7.No.If a single-threaded process is blocked on the keyboard,it cannot fork.8.A worker thread will block when it has to read a Web page from the disk.Ifuser-level threads are being used,this action will block the entire process, destroying the value of multithreading.Thus it is essential that kernel threads are used to permit some threads to block without affecting the others.9.Yes.If the server is entirely CPU bound,there is no need to have multiplethreads.It just adds unnecessary complexity.As an example,consider a tele-phone directory assistance number(like555-1212)for an area with1million6PROBLEM SOLUTIONS FOR CHAPTER2people.If each(name,telephone number)record is,say,64characters,the entire database takes64megabytes,and can easily be kept in the server’s memory to provide fast lookup.10.When a thread is stopped,it has values in the registers.They must be saved,just as when the process is stopped the registers must be saved.Multipro-gramming threads is no different than multiprogramming processes,so each thread needs its own register save area.11.Threads in a process cooperate.They are not hostile to one another.If yield-ing is needed for the good of the application,then a thread will yield.After all,it is usually the same programmer who writes the code for all of them. er-level threads cannot be preempted by the clock unless the whole proc-ess’quantum has been used up.Kernel-level threads can be preempted indivi-dually.In the latter case,if a thread runs too long,the clock will interrupt the current process and thus the current thread.The kernel is free to pick a dif-ferent thread from the same process to run next if it so desires.13.In the single-threaded case,the cache hits take15msec and cache misses take90msec.The weighted average is2/3×15+1/3×90.Thus the mean re-quest takes40msec and the server can do25per second.For a multithreaded server,all the waiting for the disk is overlapped,so every request takes15 msec,and the server can handle662/3requests per second.14.The biggest advantage is the efﬁciency.No traps to the kernel are needed toswitch threads.The biggest disadvantage is that if one thread blocks,the en-tire process blocks.15.Yes,it can be done.After each call to pthread create,the main programcould do a pthread join to wait until the thread just created has exited before creating the next thread.16.The pointers are really necessary because the size of the global variable isunknown.It could be anything from a character to an array ofﬂoating-point numbers.If the value were stored,one would have to give the size to create global,which is all right,but what type should the second parameter of set global be,and what type should the value of read global be?17.It could happen that the runtime system is precisely at the point of blocking orunblocking a thread,and is busy manipulating the scheduling queues.This would be a very inopportune moment for the clock interrupt handler to begin inspecting those queues to see if it was time to do thread switching,since they might be in an inconsistent state.One solution is to set aﬂag when the run-time system is entered.The clock handler would see this and set its ownﬂag, then return.When the runtime systemﬁnished,it would check the clockﬂag, see that a clock interrupt occurred,and now run the clock handler.PROBLEM SOLUTIONS FOR CHAPTER27 18.Yes it is possible,but inefﬁcient.A thread wanting to do a system callﬁrstsets an alarm timer,then does the call.If the call blocks,the timer returns control to the threads package.Of course,most of the time the call will not block,and the timer has to be cleared.Thus each system call that might block has to be executed as three system calls.If timers go off prematurely,all kinds of problems can develop.This is not an attractive way to build a threads package.19.The priority inversion problem occurs when a low-priority process is in itscritical region and suddenly a high-priority process becomes ready and is scheduled.If it uses busy waiting,it will run forever.With user-level threads,it cannot happen that a low-priority thread is suddenly preempted to allow a high-priority thread run.There is no preemption.With kernel-level threads this problem can arise.20.With round-robin scheduling it works.Sooner or later L will run,and eventu-ally it will leave its critical region.The point is,with priority scheduling,L never gets to run at all;with round robin,it gets a normal time slice periodi-cally,so it has the chance to leave its critical region.21.Each thread calls procedures on its own,so it must have its own stack for thelocal variables,return addresses,and so on.This is equally true for user-level threads as for kernel-level threads.22.Yes.The simulated computer could be multiprogrammed.For example,while process A is running,it reads out some shared variable.Then a simula-ted clock tick happens and process B runs.It also reads out the same vari-able.Then it adds1to the variable.When process A runs,if it also adds one to the variable,we have a race condition.23.Yes,it still works,but it still is busy waiting,of course.24.It certainly works with preemptive scheduling.In fact,it was designed forthat case.When scheduling is nonpreemptive,it might fail.Consider the case in which turn is initially0but process1runsﬁrst.It will just loop forever and never release the CPU.25.To do a semaphore operation,the operating systemﬁrst disables interrupts.Then it reads the value of the semaphore.If it is doing a down and the sema-phore is equal to zero,it puts the calling process on a list of blocked processes associated with the semaphore.If it is doing an up,it must check to see if any processes are blocked on the semaphore.If one or more processes are block-ed,one of them is removed from the list of blocked processes and made run-nable.When all these operations have been completed,interrupts can be enabled again.8PROBLEM SOLUTIONS FOR CHAPTER226.Associated with each counting semaphore are two binary semaphores,M,used for mutual exclusion,and B,used for blocking.Also associated with each counting semaphore is a counter that holds the number of up s minus the number of down s,and a list of processes blocked on that semaphore.To im-plement down,a processﬁrst gains exclusive access to the semaphores, counter,and list by doing a down on M.It then decrements the counter.If it is zero or more,it just does an up on M and exits.If M is negative,the proc-ess is put on the list of blocked processes.Then an up is done on M and a down is done on B to block the process.To implement up,ﬁrst M is down ed to get mutual exclusion,and then the counter is incremented.If it is more than zero,no one was blocked,so all that needs to be done is to up M.If, however,the counter is now negative or zero,some process must be removed from the list.Finally,an up is done on B and M in that order.27.If the program operates in phases and neither process may enter the nextphase until both areﬁnished with the current phase,it makes perfect sense to use a barrier.28.With kernel threads,a thread can block on a semaphore and the kernel canrun some other thread in the same process.Consequently,there is no problem using semaphores.With user-level threads,when one thread blocks on a semaphore,the kernel thinks the entire process is blocked and does not run it ever again.Consequently,the process fails.29.It is very expensive to implement.Each time any variable that appears in apredicate on which some process is waiting changes,the run-time system must re-evaluate the predicate to see if the process can be unblocked.With the Hoare and Brinch Hansen monitors,processes can only be awakened on a signal primitive.30.The employees communicate by passing messages:orders,food,and bags inthis case.In UNIX terms,the four processes are connected by pipes.31.It does not lead to race conditions(nothing is ever lost),but it is effectivelybusy waiting.32.It will take nT sec.33.In simple cases it may be possible to determine whether I/O will be limitingby looking at source code.For instance a program that reads all its inputﬁles into buffers at the start will probably not be I/O bound,but a problem that reads and writes incrementally to a number of differentﬁles(such as a compi-ler)is likely to be I/O bound.If the operating system provides a facility such as the UNIX ps command that can tell you the amount of CPU time used by a program,you can compare this with the total time to complete execution of the program.This is,of course,most meaningful on a system where you are the only user.34.For multiple processes in a pipeline,the common parent could pass to the op-erating system information about the ﬂow of data.With this information the OS could,for instance,determine which process could supply output to a process blocking on a call for input.35.The CPU efﬁciency is the useful CPU time divided by the total CPU time.When Q ≥T ,the basic cycle is for the process to run for T and undergo a process switch for S .Thus (a)and (b)have an efﬁciency of T /(S +T ).When the quantum is shorter than T ,each run of T will require T /Q process switches,wasting a time ST /Q .The efﬁciency here is thenT +ST /QT which reduces to Q /(Q +S ),which is the answer to (c).For (d),we just sub-stitute Q for S and ﬁnd that the efﬁciency is 50%.Finally,for (e),as Q →0the efﬁciency goes to 0.36.Shortest job ﬁrst is the way to minimize average response time.0<X ≤3:X ,3,5,6,9.3<X ≤5:3,X ,5,6,9.5<X ≤6:3,5,X ,6,9.6<X ≤9:3,5,6,X ,9.X >9:3,5,6,9,X.37.For round robin,during the ﬁrst 10minutes each job gets 1/5of the CPU.Atthe end of 10minutes,C ﬁnishes.During the next 8minutes,each job gets 1/4of the CPU,after which time D ﬁnishes.Then each of the three remaining jobs gets 1/3of the CPU for 6minutes,until B ﬁnishes,and so on.The ﬁn-ishing times for the ﬁve jobs are 10,18,24,28,and 30,for an average of 22minutes.For priority scheduling,B is run ﬁrst.After 6minutes it is ﬁnished.The other jobs ﬁnish at 14,24,26,and 30,for an average of 18.8minutes.If the jobs run in the order A through E ,they ﬁnish at 10,16,18,22,and 30,for an average of 19.2minutes.Finally,shortest job ﬁrst yields ﬁnishing times of 2,6,12,20,and 30,for an average of 14minutes.38.The ﬁrst time it gets 1quantum.On succeeding runs it gets 2,4,8,and 15,soit must be swapped in 5times.39.A check could be made to see if the program was expecting input and didanything with it.A program that was not expecting input and did not process it would not get any special priority boost.40.The sequence of predictions is 40,30,35,and now 25.41.The fraction of the CPU used is35/50+20/100+10/200+x/250.To beschedulable,this must be less than1.Thus x must be less than12.5msec. 42.Two-level scheduling is needed when memory is too small to hold all theready processes.Some set of them is put into memory,and a choice is made from that set.From time to time,the set of in-core processes is adjusted.This algorithm is easy to implement and reasonably efﬁcient,certainly a lot better than,say,round robin without regard to whether a process was in memory or not.43.Each voice call runs200times/second and uses up1msec per burst,so eachvoice call needs200msec per second or400msec for the two of them.The video runs25times a second and uses up20msec each time,for a total of 500msec per second.Together they consume900msec per second,so there is time left over and the system is schedulable.44.The kernel could schedule processes by any means it wishes,but within eachprocess it runs threads strictly in priority order.By letting the user process set the priority of its own threads,the user controls the policy but the kernel handles the mechanism.45.The change would mean that after a philosopher stopped eating,neither of hisneighbors could be chosen next.In fact,they would never be chosen.Sup-pose that philosopher2ﬁnished eating.He would run test for philosophers1 and3,and neither would be started,even though both were hungry and both forks were available.Similarly,if philosopher4ﬁnished eating,philosopher3 would not be started.Nothing would start him.46.If a philosopher blocks,neighbors can later see that she is hungry by checkinghis state,in test,so he can be awakened when the forks are available.47.Variation1:readers have priority.No writer may start when a reader is ac-tive.When a new reader appears,it may start immediately unless a writer is currently active.When a writerﬁnishes,if readers are waiting,they are all started,regardless of the presence of waiting writers.Variation2:Writers have priority.No reader may start when a writer is waiting.When the last ac-tive processﬁnishes,a writer is started,if there is one;otherwise,all the readers(if any)are started.Variation3:symmetric version.When a reader is active,new readers may start immediately.When a writerﬁnishes,a new writer has priority,if one is waiting.In other words,once we have started reading,we keep reading until there are no readers left.Similarly,once we have started writing,all pending writers are allowed to run.48.A possible shell script might beif[!–f numbers];then echo0>numbers;ﬁcount=0while(test$count!=200)docount=‘expr$count+1‘n=‘tail–1numbers‘expr$n+1>>numbersdoneRun the script twice simultaneously,by starting it once in the background (using&)and again in the foreground.Then examine theﬁle numbers.It will probably start out looking like an orderly list of numbers,but at some point it will lose its orderliness,due to the race condition created by running two cop-ies of the script.The race can be avoided by having each copy of the script test for and set a lock on theﬁle before entering the critical area,and unlock-ing it upon leaving the critical area.This can be done like this:if ln numbers numbers.lockthenn=‘tail–1numbers‘expr$n+1>>numbersrm numbers.lockﬁThis version will just skip a turn when theﬁle is inaccessible,variant solu-tions could put the process to sleep,do busy waiting,or count only loops in which the operation is successful.SOLUTIONS TO CHAPTER3PROBLEMS1.It is an accident.The base register is16,384because the program happened tobe loaded at address16,384.It could have been loaded anywhere.The limit register is16,384because the program contains16,384bytes.It could have been any length.That the load address happens to exactly match the program length is pure coincidence.2.Almost the entire memory has to be copied,which requires each word to beread and then rewritten at a different location.Reading4bytes takes10nsec, so reading1byte takes2.5nsec and writing it takes another2.5nsec,for a total of5nsec per byte compacted.This is a rate of200,000,000bytes/sec.To copy128MB(227bytes,which is about1.34×108bytes),the computer needs227/200,000,000sec,which is about671msec.This number is slightly pessimistic because if the initial hole at the bottom of memory is k bytes, those k bytes do not need to be copied.However,if there are many holes andmany data segments,the holes will be small,so k will be small and the error in the calculation will also be small.3.The bitmap needs1bit per allocation unit.With227/n allocation units,this is224/n bytes.The linked list has227/216or211nodes,each of8bytes,for a total of214bytes.For small n,the linked list is better.For large n,the bitmap is better.The crossover point can be calculated by equating these two formu-las and solving for n.The result is1KB.For n smaller than1KB,a linked list is better.For n larger than1KB,a bitmap is better.Of course,the assumption of segments and holes alternating every64KB is very unrealistic.Also,we need n<=64KB if the segments and holes are64KB.4.Firstﬁt takes20KB,10KB,18KB.Bestﬁt takes12KB,10KB,and9KB.Worstﬁt takes20KB,18KB,and15KB.Nextﬁt takes20KB,18KB,and9 KB.5.For a4-KB page size the(page,offset)pairs are(4,3616),(8,0),and(14,2656).For an8-KB page size they are(2,3616),(4,0),and(7,2656).6.They built an MMU and inserted it between the8086and the bus.Thus all8086physical addresses went into the MMU as virtual addresses.The MMU then mapped them onto physical addresses,which went to the bus.7.(a)M has to be at least4,096to ensure a TLB miss for every access to an ele-ment of X.Since N only affects how many times X is accessed,any value of N will do.(b)M should still be atleast4,096to ensure a TLB miss for every access to anelement of X.But now N should be greater than64K to thrash the TLB, that is,X should exceed256KB.8.The total virtual address space for all the processes combined is nv,so thismuch storage is needed for pages.However,an amount r can be in RAM,so the amount of disk storage required is only nv−r.This amount is far more than is ever needed in practice because rarely will there be n processes ac-tually running and even more rarely will all of them need the maximum al-lowed virtual memory.9.The page table contains232/213entries,which is524,288.Loading the pagetable takes52msec.If a process gets100msec,this consists of52msec for loading the page table and48msec for running.Thus52%of the time is spent loading page tables.10.(a)We need one entry for each page,or224=16×1024×1024entries,sincethere are36=48−12bits in the page numberﬁeld.。

智能制造英文版

智能制造英文版Intelligent manufacturingAn overviewIntelligent manufacturing deep in artificial intelligence research.Generally think that intelligence is the sum of knowledge and intelligence,the former is the basis of intelligence,the latter is the ability to acquire and apply knowledge to solve.Intelligent manufacturing should contain intelligent manufacturing technology and intelligent manufacturing system.The intelligence technique of manufacture is refers using the computer simulation marks intelligent activities such as expert’s analysis,judgment,inference, idea and decision-making and so on,and fuses organically these intelligent activity and the intelligent machine,applies its penetration in entire manufacture enterprise’s each subsystem(e.g. management decision-making,purchase, product design,productive plan,manufacture, assembly,quality assurance and market sale and so on).Realizes the entire manufacture enterprise to manage the operation highlyflexibility and integration,thus substitutes or extends in the manufacture environment expert’s partial mental labor, and carries on the collection,the memory,the consummation,sharing,the inheritance and the development of the manufacturing industry expert’s intelligent information,enhances the production efficiency enormously and the advanced technique of manufacture.The intelligent manufacture system is refers based on IMT(intelligent manufacturing technology),by the computer synthesis application artificial intelligence technology(e.g.artificial neural networks,genetic algorithm and so on), the intelligence manufacture machine,the agent technology,the parallel projects,the life sciences and the systems engineering theory and the method,in the international standardization and interchangeable foundation,causes the entire enterprise to make each subsystem to intellectualize separately,and causes the manufacture system to form by the network integrates,the highautomated one king of manufacture system.Intelligent manufacturing system can not only in practice constantly enrich the knowledge base,have the function of self-learning,and collecting and understanding of environmental information and its information,analysis and judgment and the ability to plan their actions.The basic principleStarting from the essential feature of intelligent manufacturing system in distributed manufacturing network environment,according to the basic idea of distributed integration,In the application of distributed artificial intelligence theory and method of multi Agent system, realize flexible manufacturing unit of the intelligent and flexible manufacturing system based on network intelligent integration.According to the characteristics of the distribution system of isomorphism in a local area forms for realizing intelligent manufacturing system based on the actual also reflects theinternet-based global manufacturing the realization of the intelligent manufacturing system model under the network environment.The overall idea of distributed IMS network:IMS is the essential characteristics of the individual manufacturing unit of "autonomy"and the system as a whole "self-organizing ability",its basic pattern is distributed more intelligent system.Based on this understanding,and considering the internet-based global manufacturing network environment,we put forward the Agent based distributed IMS network's basic idea,as shown in figure 1.On the one hand,through the Agent give autonomy to each manufacturing unit,making it a fully functional,autonomy, an independent entity;On the other hand, through the coordination and cooperation between the Agent,gives system self-organization ability.Multi Agent system implementation pattern of the system is easy to design, implementation and maintenance,reduce thecomplexity of the system,enhance the system's restructuring,scalability and reliability,and improve the flexibility, adaptability and agility of the system.Based on the above framework,combined with the CNC machining system,development and application of distributed network prototype system by system manager,mission planning,design and producers of four nodes.Systems manager node including two database server,database server and Agent system is responsible for the management of the entire global database,available for access of nodes in the prototype system for data query,read,storage and retrieval operations,and for each node for data exchange and sharing,to provide a public system,the Agent is responsible for the system in the network and the external interaction,through the Web server on the Internet home page of the system,users can access online home page the information related to obtaining the system,and according to their own needs,to decidewhether the system is to meet these requirements,the system of the Agent is also responsible for monitoring the interactions between the various nodes on prototype system, such as record and real-time display of sending and receiving messages between nodes, task execution,etc.Mission planning nodes by the task manager and its Agent(task manager Agent), its main function is to task planning,from the Internet is decomposed into several subtasks,and then through the way of bidding, bidding to the task allocation of each node.Design node by CAD tools and its proxy Agent(design),it provides a good man-machine interface so that designers can effectively and computer interaction,common to complete the design task.CAD tools to help design personnel according to user requirements for product design;Designed the Agent is responsible for online registration, cancellation registration,database management,interaction with other nodes, decide whether to accept the design task andsubmit a task to task the sender.Producers node is actually the project research and development of an intelligent manufacturing system(intelligent manufacturing unit),including processing center and its network proxy Agent(machine). The intelligent adaptive machining center configuration.The CNC system is controlled by intelligent controller processing process, to give full play to the processing of automated processing equipment potential, improve processing efficiency;Have certain ability of self diagnose and self repair,in order to improve the processing the reliability and safety of the equipment operation;Have the ability to interact with the external environment;With open architecture to support the system integration and extension.The prototype system work:Every node in the system must be registered through the network,to become the formal member of the prototype system to obtain the corresponding privileges,to collaboratewith other nodes in the system,common to complete the system task.The whole process of operation of the prototype system is as follows:(1)any network user can access the prototype system of the home page for information about the system,but also through the fill out and submit user order form provided by the system home page issued orders to the system;(2)if received and accept the network user's orders,Agent system is to be deposited in the global database,from the global database,mission planning nodes can take out the order,mission planning,the task decomposition into several subtasks,and assign these subtasks prototype system access nodes;(3)product design subtasks are assigned to design node,the node through good human-computer interaction to complete product design sub-tasks,generate the corresponding CAD/CAPP data and documents, and nc code,and these data and documents in the global database,finally submit the subtasks to mission planning nodes;(4) processing subtasks are assigned to producers,once the subtasks was accepted by the producers nodes,machine Agent will be allowed to read the necessary data from the global database,and to transfer the data to the processing center,processing center, according to these data and command to finish processing the subtasks,and the running status information transmitted to the machine Agent,machine Agent returns the result to the mission planning nodes,submit the subtask;(5)in the system during the running of the whole,the Agent is the interaction between the various nodes in the system for recording, such as message sending and receiving,a global database data read and write,query the node name,type,address,ability,and task completion,etc.(6)Network client can understand order execution and results.The developmentIntelligent manufacturing deep in artificial intelligence research.Artificial intelligence is the intelligence of implementation of using artificial method onthe computer.Of complicated as the WanShanHua and the structure of the product performance and refinement,as well as the function of diversification,prompting a surge in product design information and process information contained,with internal information flow increase of production line and production equipment,manufacturing process and management information must also soared,a hotspot and frontier,and thus prompt the development of manufacturing technology to improve manufacturing system for the explosive growth of manufacturing information processing ability,efficiency and scale.At present,the advanced manufacture equipment left the information input cannot operate,flexible manufacturing system(FMS)once they are cut off the source of information will immediately cease to work. Expert thinks,the manufacturing system is driven by the original energy into information driven,this requires a flexible manufacturing system requires not only,but also show that the intelligent,otherwise itis difficult to deal with such a large amount of workload and complex information.Secondly, the complex environment of rapidly changing market demand and fierce competition,also called for the manufacturing system showed higher flexibility,agility and intelligence. Across the world,although the overall intelligent manufacturing was still in the stage of conceptual and experimental,but governments are included in the national development plans,this push to implement.In 1992the implementation of new technology policy and support by the President said the key to the important technical(Critical Techniloty),including information technology and new manufacturing technology, ease of intelligent manufacturing technology, the ernment hopes the move to transform traditional industry and start a new industry.Canada's1994~1998development strategy plan,think the future knowledge intensive industry is driving the global economy and Canada,the basis of economic developmentthought is very important to development and application of intelligent system,and put the specific research project selection for intelligent computer,man-machine interface, mechanical sensor,the robot control system integration,the new device,the dynamic environment.Japan's in1989,intelligent manufacturing system is proposed and launched in1994,the advanced manufacturing international cooperation research projects, including the companies to integrate and global manufacturing,manufacturing knowledge system,distributed intelligent control system,rapid product realization of distributed intelligent system technology, etc.Research of information technology in the European Union ESPRIT project,the project is funded by the market potential of information technology.1994and the start of the new R&D project,select the39core technologies,of which three(information technology, molecular biology and advanced manufacturingtechnology)are highlights the intelligent manufacturing location.China at the end of the80's will "intelligent simulation"the main issue in the national science and technology development planning,understanding has made a number of achievements in the expert system, pattern recognition,robotics,Chinese machine.Recently,the State Ministry of science and technology put forward formally "industrial intelligent engineering",as an important part of the innovation ability of technology innovation project construction, intelligent manufacturing will be an important content of the project.Thus,the intelligent manufacturing is arising in the world,it is the development of manufacturing technology,especially the inevitable manufacturing development of information technology,is the result of the development of automation and integration technology in depth.Integrated featuresWith the traditional manufacture systemcompares,IMS has following several characteristics:(1)From organization abilityIn the IMS,each kind of composition unit can according to the work duty need, voluntarily build up one kind of ultra flexible best structure,and defers to the most superior way movement.Not only its flexibility displays in the movement way,but also displays in the structural style.After completing the task,this structure dismisses voluntarily,prepares in the next duty builds up a new kind of structure.The voluntarily organization ability is an IMS important symbol.(2)Autonomy abilityIMS has the abilities such as collection and the understanding the environmental information and own information,and carries on the analysis to judge and to plan own behavior ability.The powerful knowledge library and based on the knowledge model is the autonomy ability foundation.IMS can act according to the environment and own workcondition information to carries on the monitor and processing,and according to the processing finally self-adjusting control strategy,uses the best movement plan.This kind of autonomy ability causes the entire manufacture system to have the anti jamming, auto-adapted and fault-tolerant and so on.(3)The ability of self-study and maintenanceIMS can take the original expert knowledge as the foundation,in reality carries on the study unceasingly,the perfect system knowledge library,and deletes the unsuitable knowledge in the storehouse, causes the knowledge library to hasten reasonably.At the same time,it also can carry on the self-diagnosis,the elimination and repairing to the system failure.The kind of character enables IMS to optimize and to adapt to each kind of complex circumstances.(4)Entire manufacture system intelligent integrationWhile IMS emphasized each subsystem intellectualization,pays great attention to the entire manufacture system the intelligentintegration.This is the basic difference between IMS and“the intellectualized isolated”which specially applied in the manufacture process.IMS contains each subsystem,and integrates them in a whole, realizes the whole intellectualization. (5)Man-machine integration intelligence systemIMS is not a pure the artificial intelligence the system,but is the man-machine integration intelligence system, is one kind of mix intelligence.On the one hand,the man-machine integration prominent person’s core status in manufacture system, simultaneously under the intelligent machine coordination,well has displayed human’s potential,causes between the man-machine to display one kind of equality to work together as colleagues,“understands”mutually, cooperates mutually relations,causes them to reveal respectively in the different level, complements each other.Therefore,in IMS, the high quality,the high intelligent person will play a better role,the machineintelligence and human’s wisdom integration of machinery Mechatronics issue can integrate truly in together.In summary,we may view IMS as one kind of pattern,it is the collection of automation, flexibility,integration and intellectualization in a body,and unceasingly to depth development advanced manufacture system.(6)Virtual realityThis technology supports the realization hypothesized manufacture,also realizes one of high level man-machine integration.The man-machine union is a new generation of intelligent contact surface,causes the available hypothesized method with intelligent performance into reality,it is a dominant character of intelligent manufacture.Future development1、Artificial intelligence technology.Since the goal of IMS is computer simulation of intelligence activities of manufacturing human experts,partial mentallabor to replace or extension of the people, so the artificial intelligence technology has become one of the key technology of IMS.IMS and artificial intelligence technology (expert system,artificial neural network, fuzzy logic)is closely related to.2、Concurrent engineering.In view of the manufacturing,concurrent engineering is an important technical method, used in IMS,will reduce the repetition blindness and the design of the product design.3、Information network technology.Information network technology is the process of manufacturing system and each link "intelligent"support.The information network is also the manufacturing information and knowledge flow channel.4、The virtual manufacturing technology.Virtual manufacturing technology can simulate the entire life cycle of product in the product design stage,thus the more effective,more economical,more flexible organization of production,the productdevelopment cycle is short,the product cost is the lowest,the optimal product quality, production efficiency is the highest assurance.At the same time,the virtual manufacturing technology is the prerequisite for the engineering realization of parallel.5、Discipline construction.Collect and understand the environment information and its information and analysis judgment and plan their behavior.Strong knowledge base and knowledge based model is the basis of self-discipline.6、Man-machine integration.Intelligent manufacturing system is not only the"artificial intelligence system,and human-machine intelligent system,is a kind of hybrid intelligent.Want to completely replace human intelligence artificial intelligence expert in manufacturing process, analysis,judgement,decision independently undertake the task,at present is not realistic.Humachine highlighted the core position in manufacturing system,combined with intelligent machines,better play ofhuman potential,to achieve a kind of collaborative working relationship of equality,so that the two made at different levels,each other.7、Self organization and super flexible.To each unit in intelligent manufacturing systems can be based on task,form an optimal structure,the flexible displays not only operation mode,but also in the structure form, so that the flexible super flexible,similar to biological features,overall as a group of human experts.Conclusion:nowadays,the research of intelligent manufacturing at home and abroad was still in the stage of concept formation and experimental exploration.In recent years, developed for the specific link,the specific problems in the process of manufacturing the "intelligent island",and"smart"machine for manufacturing environment full of research is still in its beginning stage.Intelligent manufacturing is a rich content,wide prospect area.In the era of socialinformatization,the new century of knowledge economization,vigorously carry out the research of intelligent manufacturing technology and system,will improve the overall level of manufacturing industry inthe comprehensive our country,enhancenational strength.。

机械制造专业外文翻译--切削,钻削

外文原文：.SawingSawing is the parting of material by using metal disks, blades, bands, or abrasive disks as the cutting tools. Sawing a piece from stock for further machining is called cutoff sawing, while shaping of forming a piece is referred to as contour sawing.Machine sawing of metal is performed by five types of saws or processes: hacksawing, babd sawing, cold sawing, friction sawing, and abrasive sawing.Hacksaws are used principally as cutoff tools. The toothed blade, held in tension,is reciprocated across the workpiece. A vise holds the stock in position. The blade is fed into the work by gravity or spring. Sometimes a mechanical or hydraulic feed is used. Automatic machines, handling bar-length stock, are used for continuous production.Band saws cut rapidly and are suited for either cutoff or contour sawing. The plane in which the blade operates classifies the machine as being either vertical or horizontal. Band saws are basically a flexible endless band of steel running overpulleys or wheels. The band has teeth on one side and is operated under tension. Guides keep it running true. The frame of the horizontal type is pivoted to allow positioningof the workpiece in the vise. Horizontal machines are used for either straight or angular cuts. A table that supports the workpiece and the wide throat between theupright portions of the blade makes the vertical band saw ideal for contour work. Band saws operating at high speed are frequently used as friction saws.Cold sawing is principally a cutoff operation. The blade is a circular disk with cutting teeth on its periphery. Blades range in size from a few inches to several feetin diameter. The cutting teeth may be cut into the periphery of the disk or they may be inserts of a harder material. The blade moves into the stock with a positive feed. Stock is positioned manually in some cold-sawing machines, while other models are equipped for automatic cycle sawing.Friction sawing is a rapid process used to cut steel as well as certain plastics. This process is not satisfactory for cast iron and nonferrous metals. Cutting is done as the high-speed blade wipes the metal from the kerf after softening it with frictional heat. Circular alloy-steel blades perform cutoff work, thile frictional band saws doboth cutoff and contour sawing. Circular blades are frequently cooled by water or air. Circular blades are adcanced into the work, thile thick work-pieces require power-table feed then friction-cut on a band saw.Abrasive sawing is a cutoff process using thin rubber or bakelite bonded abrasive disks. In addition to steel, other materials such as nonferrous metals, ceramics, glass, certain plastics, and hard rubber are cut by this method. Cutting is done by the abrasive action of the grit in the disk.Abrasive disks are operated either wet or dry. For heavy cutting a cooling agent is generally used. The workpiece is firmly held while the wheel traverses through it. Machines are made in manually operated and automatic models.DrillingHoles are one of the most common features in products manufactured today. There-fore, drilling and other related processes and tools are extremely important. Holes as small as 0.005in.may be drilled using special techniques. On the other hand , holes larger than 2 to 221in. in diameter are seldom drilled, because other processes and techniques are less expensive.The twist drill (shown in Fig.12-3) is the most common type of drill. The shank of the drill is held by the machine tool, which in turn imparts an rotary motion. This shank of the drill is held by the machine tool. Which in turn imparts a rotary motion. This shank may be straight or tapered. The body of the drill is typically made up of two spiral grooves known as flutes, which are defined by a helix angle that is generally about 30ºbut can vary depending on the material properties of the workpiece. The point of the drill (see Fig.12-3) generally form a 118ºangle and includes a 10 clearance angle and chisel edge. The chisel edge is flat with a web thickness of approximately 0.015 * drill diameter. This edge can cause problems in hole location owing to its ability to “walk ” on a surface before engaging the workpiece. In the case of brittle materials,drill point angles of less than 118º are used, while ductile materials use larger points angles and smaller clearance angles.Complex hole configurations may often be called for; these include multiple diameters, chamfers, countersinks, and combinations of these, as illustrated in Fig.12-4. In each of these cases in is possible to make special combination drills that can produce the configurations shown in a single operation. Although expensive, they can be economically justified for sufficient volume.The flat chisel edge, which can “walk” on the surface of the workpiece, and the long , slender shaft and body of the twist drill, which can deflect, make it difficultto machine holes to tight tolerances. A combination center drill and countersink can be used to accurately start a hole, owing to its small web thickness and its tendency to deflect only very small amounts (because of a relatively large diameter-to-lengthratio) . Truing of the hole to make it straight is accomplished by boring. Reaming the hole provides a better finish as well as more accurate sizing.The feed rate of a drill is normally proportional to its diameter, because it depends on the volume of chips the flutes can handle. However the feed is independent of thecutting speed, which is a function of the tool-work combination. A rule of thumb would give a feed rate as approximately d/65,so that a 3/4-in.-diameter drill would have afeed rate of about 0.012 in. /rev. Although the hole wall tends to support the drill when the hole depth exceeds three times the drill diameter, there is a tendency for buckling to occur and the feed rate should be reduced.Most drills are made from high –speed steel because of its relatively low cost and ease of manufacture. Some types of carbide drills are now available commercially. The demands of numerically controlled machine tools have led to the development of drills that will produce pore precise holes and that will originate a hole in line with the centerline of the drill-press spindle. Drills that have heavier webs, less stickout, double margins, and are ground with a spiral point help meet these new demands.ReamingReaming is a machining process for enlarging, smoothing and/ or accurately sizing existing holes by means of means of multiedge fluted cutting tools (reamers) . As thereamers and / or workpiece is rotated and advanced relative to each other, chips are produced to remove relatively small amounts of material from the hole wall. Reaming may be performed on the same type of machines used for drilling.Accuracy of the hole and quality of finish produced by reaming depends primarily upon the condition of the starting bole, rigidity of the machine and fixture, correct speeds and feeds, a suitable and properly applied cutting fluid, and precise resharpening of dull tools.Since stock removal is small and must be uniform in reaming , the starting holes (drilled or otherwise produced) must have relatively good roundness, straightness, and finish. Reamers tend to follow the existing centerline of the hole being reamed, and in limited instances it may be necessary to bore the holes prior to reaming to maintain required tolerances. With the proper conditions and operating parameters, reaming can produce close tolerances and smooth finishes.ReamersAreamer is a rotary cutting tool, generally of cylindrical or conical shape, intended for enlarging and finishing holes to accurate dimensions. It is usually equipped with two or more peripheral channels or flutes, either parallel to its axis or in a right– or left-hand helix as required. Those with helical flutes provide smooth shear cutting, are less subject to chatter, and produce a better finish. The flutes form cutting teeth and provide channels for removing the chips.Kinds of ReamersReamers are made in many different forms, including solid and inserted-blade types, adjustable and nonadjustable; they are available for either manual operation (hand reamers) or for machine use (chucking reamers). Materials from which cutting elements of most production reamers are made include high-speed steeland cemented carbides. of most production reamers are made include high-speed steel and cemented carbides.Carbide reamers These tools are being used increasingly because of their linger life, improved accuracy, and resistance.Bore reamers These tools combine boring and reaming in a single operation to minimize problems with respect to hole size, straightness, and finish. Single-point bore reamers, for use in applications for which guide bushings can be used, have a single-point cutting edge on the end of the tool, followed by a reaming section. Multipoint bore reamers are available for applications for applications for which bushings cannot be used.Coolant-fed reamers These tools, having means (usually internal passages) for directing coolant to the cutting edges, offer advantages for some applications, particularly when reaming blind holes. In such applications, reduced friction and temperatures at the reamer /workpiece interface decrease wear and lengthen tool life. Insome cases, feeds and speeds can be increased and improved accuracies and smoother finishes obtained. The initial cost of coolant-fed reamers is higher , but increased productivity and improved quality often make them economically desirable.Reamer Holders/ DriversReamers are commonly held and driven by three-jaw chucks, straight sleeves and setscrews, and, for taper shanks, sleeves or sockets. Reamers with adapters for quick-change chucks are used for production applications.When reamers must guide themselves into previously made holes, they require gloating holders to maintain alignment. There are several types of floating holders. Some permit angular float, others permit a parallel (axial) float, and still others permit both angular and parallel float.Floating holders have some limitations. If the reamer axis is vertical, floating reamer drives often do a good job of correcting for small amounts of misalignment. When the workpieces rotate, however, as is the case on screw machines, lathes, and some other machine tools, floating holders are sometimes inadequate. This is because relatively large amounts of misalignment are often found on these machines and because the weight of the reamer and holder tend to push the tool into an off-center position.Some full floating holders, which compensate for both angular and parallel misalignment, are equipped with springs or other components to counterbalance the mass of the holder. A floating holder cannot generally operate both vertically and horizontally and still correct for both angular and parallel misalignment. Application details (vertical or horizontal operation and rotating or stationary tool) should be specified when a floating holder is ordered.Workholding for ReamingJig design and the use of bushings for reaming are essentially the same as for drilling. Major functions of the jigs and bushings are accurate locating, supporting, and securing of the workpieces, and precise guiding of the tools. A difference for reaming is that closer tolerances are generally required on both the jigs and bushings.Operating Parameters for ReamingFactors that must be established for efficient and economical reaming include the proper cutting speed, feed rate, and cutting fluid to be used Other important considerations are resharpening the reamers and troubleshooting the operations.中文译文：锯削锯削是利用金属圆锯、锯条、带锯或砂轮作为切削工具将材料分开。

高二英语航空英语单选题50题

高二英语航空英语单选题50题1. You can board the plane at the _____.A. airportB. stationC. portD. terminal答案：D。

本题考查航空相关场所名词。

选项A“airport”是机场的总称；选项B“station”通常指火车站；选项C“port”一般指港口；选项D“terminal”是航站楼，登机通常在航站楼，所以选D。

2. The pilot controls the plane from the _____.A. cockpitB. cabinC. holdD. lounge答案：A。

选项A“cockpit”是驾驶舱，飞行员从驾驶舱控制飞机；选项B“cabin”是客舱；选项C“hold”是货舱；选项D“lounge”是候机室，所以选A。

3. Passengers put their luggage in the _____.A. overhead compartmentB. basementC. drawerD. closet答案：A。

选项A“overhead compartment”是头顶上方的行李架；选项B“basement”是地下室；选项C“drawer”是抽屉；选项D“closet”是壁橱，乘客把行李放在头顶上方的行李架上，所以选A。

4. The plane takes off from the _____.A. runwayB. streetC. roadD. path答案：A。

选项A“runway”是跑道，飞机从跑道起飞；选项B“street”是街道；选项C“road”是道路；选项D“path”是小路，所以选A。

5. The air hostess serves drinks in the _____.A. kitchenB. cafeteriaC. galleyD. restaurant答案：C。

选项A“kitchen”是厨房，一般指家庭厨房；选项B“cafeteria”是自助餐厅；选项C“galley”是飞机上的厨房；选项D“restaurant”是餐馆，空乘人员在飞机上的厨房服务饮料，所以选C。

航海英语试题及答案

航海英语试题及答案一、单项选择题（每题2分，共20分）1. The term "port" refers to which side of the ship?A. Left sideB. Right sideC. SternD. Bow答案：A2. What does the acronym "AIS" stand for in maritime communication?A. Automatic Identification SystemB. Advanced Information SystemC. Automatic Information SystemD. Advanced Identification System答案：A3. Which of the following is not a type of navigational buoy?A. Can buoyB. Cone buoyC. Barrel buoyD. Anchor buoy答案：D4. What is the standard speed for a ship to proceed at when entering or leaving a port?A. 5 knotsB. 10 knotsC. 15 knotsD. 20 knots答案：A5. Which of the following is not a maritime distress signal?A. SOSB. MaydayC. Pan-panD. Help答案：D6. What is the minimum safe distance a ship should maintain from a submarine when passing?A. 500 metersB. 1000 metersC. 1500 metersD. 2000 meters答案：B7. What does the term "deadweight" refer to in shipping?A. The weight of the ship without cargoB. The maximum weight the ship can carryC. The weight of the cargo onlyD. The weight of the ship with cargo答案：B8. Which of the following is not a type of maritime document?A. Bill of ladingB. Certificate of registryC. PassportD. Cargo manifest答案：C9. What is the international maritime signal flag for "I require a pilot"?A. AlphaB. BravoC. DeltaD. Echo答案：A10. What is the standard time zone for all maritime navigation?A. Greenwich Mean Time (GMT)B. Coordinated Universal Time (UTC)C. Eastern Standard Time (EST)D. Pacific Standard Time (PST)答案：B二、填空题（每题2分，共20分）1. The international maritime distress frequency is _______ MHz.答案：21822. The term "freeboard" refers to the distance between the _______ and the waterline.答案：deck3. A ship's _______ is the part of the ship that extends vertically from the waterline to the deck.答案：hull4. The _______ is the officer in charge of the navigation and safety of the ship.答案：captain5. The _______ is a device used to measure the depth of water under the ship.答案：sounder6. The _______ is a maritime signal flag that indicates the need for medical assistance.答案：Alpha7. The _______ is the part of the ship that is used for loading and unloading cargo.答案：cargo hold8. The _______ is a maritime signal flag that indicates the need for a tugboat.答案：Bravo9. The _______ is the part of the ship that is used for steering.答案：rudder10. The _______ is a maritime signal flag that indicates the need for a pilot.答案：Delta三、简答题（每题10分，共40分）1. Explain the function of a radar in maritime navigation.答案：Radar is a system that uses radio waves to determinethe range, angle, or velocity of objects. It is used in maritime navigation to detect and locate other vessels, land, and obstacles, as well as to navigate in poor visibility conditions.2. Describe the importance of maintaining a proper lookout while at sea.答案：Maintaining a proper lookout is crucial for the safe navigation of a ship. It involves continuously monitoring the surrounding environment to detect any potential hazards or changes in conditions, such as other vessels, weather patterns, or navigational markers. This helps in avoiding collisions, grounding, or other maritime accidents.3. What are the responsibilities of a ship's officer in charge of navigation?答案：The officer in charge of navigation is responsible for planning the ship's route, overseeing the operation of navigational equipment, ensuring compliance with maritime regulations, monitoring weather conditions, and making decisions to ensure the safe and efficient passage of the ship.4. Explain the significance of the International Maritime Organization (IMO) in global shipping.答案：The International Maritime Organization (IMO) is a specialized agency of the United Nations responsible for regulating shipping. It develops and maintains a comprehensive regulatory framework to ensure the safety and security of shipping, the prevention of marine pollution, and the facilitation of international maritime traffic. The IMO'swork is essential for promoting cooperation among nations, setting global standards, and addressing maritime issues that affect the entire world.。

机电一体化专业外文翻译--机电一体化技术发展

外文原文：1, electromechanical integration and the development of technology trends Since an electronic technology birth of electronic technology and mechanical technology integration began, only a semiconductor integrated circuit, particularly in a microprocessor representative of the large-scale integrated circuits for the future, "mechatronics," a technical after significant progress, and has attracted widespread attention.(1) mechanical-electrical integration, "the course of development1. CNC machine tools come out, wrote "mechatronics," the first page of history;2. Microelectronic technology, "mechatronics''bring a great vitality;3. PLC, "Power Electronics" for the development of "mechatronics" provide a firm foundation;4. Laser technology, fuzzy technology, information technology and other new technologies to "mechanical and electrical integration," a new and higher level.(B) mechanical-electrical integration, "the development trend1. Integration of optical and electrical machinery. General mechanical and electrical integration system by sensing systems, energy systems, information processing systems, machinery, and other components of the structure. Therefore, the introduction of optical technology, the realization of the inherent advantages of optical technology is effective Improved mechanical-electrical integration system sensing system, energy (power) systems and information processing system. optical and electrical machinery integration is the development of mechanical and electrical products trend.2. Systematic self-distribution - Flexible Future electromechanical integration products, and implementation of control systems are adequate "redundancy" and more "flexible" and can better deal with an emergency, is designed "self-distribution system." Self-discipline in the distribution system, the various subsystems are independent of each other's work, the subsystem for system services, and has its own "self-discipline", according to different environmental conditions react differently. Its characteristics are subsystem can generate its own information and additional information given in the overall premise, specific "action" can be changed. In this way,significantly increase the system's ability to adapt (flexible), not because of the failure of a subsystem of the whole system.3. Holographic systematic - intelligent. Future integration of mechanical and electrical products, "holographic" features more and more obvious, more and more high-level intelligence. This is mainly revenues in the fuzzy technology, information technology (especially software and chip technology) development. In addition, the hierarchical structure of the system, a simple change of "top-down" situation is complex, there is much more two-way link redundancy.4. "Of a software" of the - Biomimetic systematic. Future integration of electrical and mechanical devices on the dependence of great information, and often the structure is in a "static" instability, but in a dynamic (work) when is stable. This is a bit like living biological: When control system (the brain) to stop work, then of "Death", and when control system (brain) work, the biological vitality. Bionics research in the field of a number of organisms have been found good institutions can provide products for the electrical and mechanical integration of the new body, but how to live with these new body of "Life" has to be in-depth study. This field of study referred to as "biological - Software" or "biological - System", and biological characteristics of the hardware (body) - Software (brain) one and indivisible. It seems, electromechanical integration of the products although there are more systematic development, but there is a long way to go.5. MEMS of - miniaturization. At present, the semiconductor devices used in the manufacturing process of etching technology, in the lab has produced sub-micron mechanical components. When will this result for the actual product, there is no need to distinguish between the mechanical part and controller. Will be completely mechanical and electronic "integration", and the body, the Executive Body, sensors, such as CPU can be integrated with the size of a small, and the formation of a self-regulatory components. This micro-mechanical integration of electromechanical important direction of development.Second, the typical electromechanical integration productsMechanical and electrical subsystems integration products (complete machine) and the foundation yuan, part two categories. Typical mechanical-electricalintegration system: CNC machine tools, robotics, automotive electronic products, intelligent instrumentation, electronic publishing printing systems, CAD / CAM systems. Typical electromechanical integration yuan, components are: power electronic devices and devices, programmable logic controller, fuzzy controller, micro-motors, sensors, ASIC, servo institutions. These typical electromechanical integration of technical status quo and development trends, market analysis of (not quoted);.Third, China's development "mechatronics" the situation and tasks facingMechanical and electrical integration mainly include two levels: First, by using microelectronic technology to transform traditional industries, and its purpose is energy and materials to enhance efficiency, improve product quality, the traditional industries of technological advances in improving step two is to develop automated, digital , intelligent mechanical and electrical products, and promote the upgrading of products.(1) China's "mechatronics" of the situation facing1. China's microelectronics technology to transform traditional industries with the workload of large and broad, difficult2. Electromechanical integration technology with China's accelerated product upgrading, enhancing the voice of the market share, pressure.3. Electromechanical integration with China replaced by products of low technology content and added value, energy, water, supplies, pollution, disturbing product liability heavy and meaningful. China's industrial systems, energy consumption, water consumption big, serious environmental pollution enterprises also accounted for a fairly large proportion. In recent years China's industrial structure, product mix Although several adjustments, but for various reasons, lack of effectiveness has been obvious. This is a higher level inside leading departments from many doors, enterprises are "finding it hard to leave their native land", "is entrenched industry", but also optimize the undeniable not the ideal industry, the optimized no Italian products. The best answer long ago put these enterprises in the face, this is the development of mechanical and electrical integration, development and production of the electrical and mechanical integration products. Mechatronics product featuresstrong, good performance, high-quality, low cost, and has a flexible, according to the needs of the market and reflect the user when the product mix and production process to do the necessary restructuring and reform, instead of switching equipment. This is the solution of mechanical and electrical products and more variety, the less important way to mass production. At the same time, for the traditional mechanical industries injection of fresh blood, bringing new vitality, and the heavy machinery production from the manual relieved to achieve civilized production.Furthermore, from the point of view of market demand, China's research and development of mechanical and electrical integration products with no long history, a big gap between the many varieties of product, quantity, grade, quality, can not meet the demand, larger than the annual import volume, much-needed development.(2) China's "mechatronics," the taskChina's mechanical and electrical integration, the task can be summed up in two sentences: The first observation is extensively used electromechanical integration technology to transform traditional industries; Another observation is that the mechanical and electrical integration in a big way to develop products, and promote the upgrading of mechanical and electrical products. The overall goal is to promote the formation of mechanical and electrical integration industry for China's industrial structure and product mix adjustment and make contributions.In short, electromechanical integration technology is to revitalize traditional electromechanical industrial source of fresh blood and driving force, is to open China's electromechanical industry products, the industrial structure adjustment of the keys to the door.Fourth, China's development "mechatronics" Countermeasures(1) strengthen the co-ordination arrangements, coordinated development planCurrently, the country engaged in "mechatronics" research and development and production of many units. Each had a set of its own development strategy. The units in their plans because of the foothold, the focus of the restrictions, it is inevitable to consider only local interests, the competent departments of the project and planning, lack of a unified consider, and make enough issue, the lack of authoritative Looking at the overall development plans and strategic planning. It is therefore recommendedthat the competent departments instruct the relevant units of in-depth investigation and study and scientific analysis on the basis of the overall development of a unified management "mechatronics" research, development, production plans and programmes to avoid duplication of development, production crashes!(B) strengthen regulation of the industry, to play the "Association" roleAt present, China's "mechatronics" more heat, while the current industry breakdown methods and management system, "from many doors" is the difficult pyridoxine. Therefore, it is necessary to clarify our country a "mechatronics" industry's management body, according to the country's political and economic reforms the spirit, as well as mechanical and electrical integration industry characteristics, we propose that the Beijing as soon as possible to strengthen the construction of the Electrical and Mechanical Integration Association, given its industry management functions. "Association" We should further expand the leadership - the representatives of the Governing Council and the level of coverage, we must strengthen the Office of the Secretariat building; able to pass its smart offices, economic entities, organizations, "industry" development, strategic planning fiction; guidance layout layout of the industry adjustment, the starting point for the development of options, do a good job of the pilot and key projects of the issuing of the project, the tender exercise……(C) Optimization development environment, increased support for theOptimization development environment that through propaganda among the masses, creating a community as a whole, both inside and outside the enterprise to support "the mechanical and electrical integration," the atmosphere of development, such as China as soon as possible for foreign investors to invest in the development of "mechatronics" industry to provide convenient as possible for the establishment of development, production integration of mechanical and electrical products give the green light to high-tech enterprises; endeavour to develop, manufacture electromechanical integration products, such as the deployment of elements of good resources.Increase the intensity of support, technology policy, it is necessary to strictly limit the consumption of electricity, water, supplies high-traditional productdevelopment, did not use the mechanical and electrical integration of backward technology products restrictions mandatory elimination; strongly advocated using electromechanical integration on the traditional industries for the transformation of the electrical and mechanical integration technology to transform traditional industries dry on the technical development and application of project priority projects, and give priority support to the technical development and application of the unit to contribute to leadership, science and technology personnel of recognition incentives.(D) to highlight key development, take into account the "two levels"Mechatronics industries cover a very wide, and our financial, human and material resources are limited, so we grasp mechatronics industry development can not be exhaustive, Bengpuzhixu, it should distinguish between primary and secondary, bold choices, in order, selective. Attention should be paid to work on two levels. The first level is the "face" of work, namely the use of electronic information technology to transform traditional industries, in the traditional electromechanical devices implanted or grafted on Microelectronics (computer) devices, the "machinery" and "electronic" technology in the Jiancengci integrate. The second level is the "increase", that is the beginning of the new product design, they "machinery" and "electronic" unified consideration, "machinery" and "electronic" inextricably linked, in-depth integration of the new production Products are at least do electromechanical integration.CONCLUSION: In this paper, in the careful guidance of teachers and strict requirements have been completed. Learning and life, will always feel the careful guidance of a mentor and selfless caring, I benefited. You are here to express our deep gratitude and lofty respect. Why not plot to跬step of a thousand miles, the smooth completion of the design, but also owe much to the datum related to the serious and responsible teacher, I can well understand and use our professional knowledge, and to be reflected in the design. At the same time, I collected a lot of online information before making my dissertation work smoothly. College of Engineering here to all teachers expressed heartfelt thanks.中文译文：一、机电一体化技术发展历程及其趋势自电子技术一问世,电子技术与机械技术的结合就开始了,只是出现了半导体集成电路,尤其是出现了以微处理器为代表的大规模集成电路以后,"机电一体化"技术之后有了明显进展,引起了人们的广泛注意.(一)机电一体化"的发展历程1.数控机床的问世,写下了"机电一体化"历史的第一页;2.微电子技术为"机电一体化''带来勃勃生机;3.可编程序控制器、"电力电子"等的发展为"机电一体化"提供了坚强基础;4.激光技术、模糊技术、信息技术等新技术使"机电一体化"跃上新台阶.(二)机电一体化"发展趋势1.光机电一体化.一般的机电一体化系统是由传感系统、能源系统、信息处理系统、机械结构等部件组成的.因此,引进光学技术,实现光学技术的先天优点是能有效地改进机电一体化系统的传感系统、能源(动力)系统和信息处理系统.光机电一体化是机电产品发展的重要趋势.2.自律分配系统化——柔性化.未来的机电一体化产品,控制和执行系统有足够的“冗余度”，有较强的“柔性”，能较好地应付突发事件，被设计成“自律分配系统”。

各种船舶的英语翻译

各种船舶的英语翻译〖文字大小：大中小〗〖打印〗〖收藏到：QQ 百度雅虎〗〖在线字典〗dugout 独木舟barge 驳船kayak (爱斯基摩人的)木排outrigger 桨叉架船rowing boat 划艇(美作:rowboat)gondola (意大利的)长平底船whale mother ship 捕鲸母船hydrofoil 水翼船catamarans 双体船dredger 挖泥船boat 船brig, brigantine 双桅船canoe 小船,独木舟caravel 快帆船cargo boat 货船coaster 近海贸易货船cod-fishing boat 捕鳕鱼船whaler 捕鲸船collier 运煤船battleship 战船shallop 小型战船coastguard cutter, coastguard vessel 巡逻艇,缉私艇revenue cutter 缉私船patrol boat 巡逻艇minelayer 布雷艇minesweeper 扫雷艇torpedo boat 鱼雷艇frigate 轻护航舰gunboat 炮舰submarine 潜水艇destro（转载自第一范文网，请保留此标记。

）yer 驱逐舰corvette 轻巡洋舰cruiser 巡洋舰aircraft carrier 航空母舰ferry, ferryboat 渡船,渡轮fishing boat 渔船freighter 货船galleon 大型帆船galley 大划桨船hovercraft 气垫船icebreaker 破冰船launch 艇lifeboat 救生艇lighter 驳船liner, ocean liner 远洋班轮merchant ship, merchantman 商船motorboat 摩托艇outboard 尾部装有马达的小艇paddle steamer, paddle boat 明轮船passenger boat 客船piragua, pirogue 独木舟raft 木筏rowing boat 划艇sailing boat, sailing ship 帆船schooner 纵帆船ship 船skiff 小艇sloop 单桅船steamer, steamship 汽轮tanker 油轮trawler 拖网渔船tug, tugboat 拖轮vessel 船yacht 游艇yawl 船载小艇您可以访问第一范文网（）查看更多与本文《各种船舶的英语翻译》相关的文章。

轮机工程英语句子1

他们打开气缸盖用葫芦吊出活塞。
21．The clock in the engine room is one minute slower than that on the bridge.
机舱的钟比驾驶台的慢一分钟。
22．This kind of bolt is no longer in production
11．The port authority will carry out an inspection when we call at a foreign port.
我们靠外国港时，港务当局要进行检查。.
12. The International Maritime Organization is usually called IMO for short.
in our company.
5．I want to know if the boiler worked well last voyage.
我想知道上个航次锅炉是否运行正常。
6．The main engine and all the auxiliary equipment are home-designed and built with domestic materials.
所有的备件及物料已送到船上。
9．This is the reason why the temperature is a bit too high.
这就是温度偏高的原因。
10．Plnd then fuel oil.
请先装柴油，再加燃油。
请换轻油备车。
16．We always keep our engine room clean and tidy
我们始终保持我们的机舱整洁。

国际商务英语单词

Unit1customs areavisible tradeinvisible tradegross domestic product（GDP）portfolio investmentstocksbondscertificate of depositlicensingfranchisingtrademarkpatentroyaltycopyrightlicensorlicenseefranchiserfranchiseemanagement contractvalue chaincontract manufacturingturnkey projectBOT （Build Operate Transfer） intellectual propertyUnit2national incomeGNP(Gross National Product）per capita incomePPP(purchasing power parity) consumerismincome distributionOrganization of Economic Cooperation a nd DevelopmentinfrastructureCommonwealth of Independent States staple goodscreditor countryASEANfactors of production 关税区有形贸易无形贸易国内生产总值证券投资股票债券大额存单许可经营特许经营商标专利专利使用费，许可使用费，版税版权给予许可的人接受许可的人给予特许的人接受特许的人管理合同价值链承包生产“交钥匙”工程建设、经营、移交知识产权国民收入国民生产总值人均收入购买力平价消费，消费主义收入分布经济合作与发展组织基础设施独立国家联合体（独联体）大路货债权国东南亚国家联盟生产要素economic integrationput up barriersfree trade areatariff ratesquota restrictionsNorth American FreeTrade Agreement(NAFTA)customs unioncommon marketsovereign statepolitical entitysignatorysettlementbanknotescirculationexecutive bodyEuropean Commissioncommissionercouncil of ministersmulti-polarizationDual-Ministerial Meetingsub-committeecartedOPECin a detourterritory economics internationalizationinternational economic environment double digittechnical improvementsday-to-day runningjurisdictionaffiliateshare holdershost countriesnatural resourcesprimary commoditiesspecializationeconomies of scaleendowment of naturecapital,land and labourabsolute advantagecomparative advantagetariffs barriers 经济一体化设置障碍自由贸易区关税税率配额限制北美自由贸易协定关税同盟共同市场主权国家政治实体签字国，签字人结算纸币，钞票货币流通行政机构，执行机构欧盟委员会委员，特派员，专员部长理事会多极化双部长会议分委员会卡特尔，联盟石油输出国组织以迂回的方式区域性经济体国际化国际经济环境两位数字的技术进步日常管理权利，管理范围分支机构，附属机构股东东道国自然资源初级产品专业化规模经济自然的赋予资本、土地和劳动力绝对利益比较利益关税壁垒quotacustoms unionimport dutiesexport dutiesad valorem dutiesspecific dutiescompound dutiesdrawbackmost-favoured-nation（MFN）treatment concessiontariff schedulenon-tariff barriermeans of transportinland water vesselscargo compartmentplaces of historical interest accommodationsimmigrantremittancetrade termstrading practicesamendmentpremisesdestinationroll on-roll off trafficcustoms clearancetrade fairstrunk callenquiryquotationvalidity periodoffereecounter offersales contractsales(purchase)confirmation business linecontract properconsignmentcontracting partiesforce majeurearbitrationcotton piece goodscotton yarnsarticle number 配额关税同盟进口关税出口关税从价税从量税复税，混合关税退税最惠国待遇让步税率表，税则非关税壁垒运输工具内河船只货仓古迹膳宿供应，招待设备移民汇款贸易术语；交易条件贸易惯例修正案；修正条款；修改（企业、机构等使用的）生产场所经营场址目的地，终点滚装滚卸式运输结关商品交易会长途电话询盘，询价报价有效期收盘人还盘销售合同售货（购货）确认书业务范围，经营范围合同本身，合同正文寄售缔约方不可抗力仲裁棉布棉纱货号counter tradeterminologynet positionshyperinflationEuropean Payment Unioncompetitive devaluation photocopying machineclearing systemcompensation tradeprocessing tradeleasingagencypolicy objectivesprotectionismfinancial marketcentrally planned economiesdebtordebitfinancial standingcreditworthinessperiodic paymentscash in advancedraftbill of exchangedrawerdraweepayeeusance draft(tenor draft,term draft) documentary draftclean draftbill of ladingtitle to the goodsinsurance policydocumentary collectiondocuments against payment(D/P) documents against acceptance(D/A)go bankruptopen accountapplicantopening bankbeneficiarycorrespondent bankadvising bankconfirming bank 对销贸易；反向贸易术语实际头寸极度通货膨胀欧洲支付联盟竞争性贬值复印机清算系统，清算制度补偿贸易加工贸易租赁代理政策目标贸易保护主义金融市场中央计划经济国家债务人借方，记入借方的款财务状况资信可靠状况分阶段付款预付现金汇票汇票出票人受票人受款人远期汇票跟单汇票光票提单货物所有权保险单跟单托收付款交单承兑交单破产记账交易开证申请人（也叫opener或principal) 开证银行受益人往来行，关系行通支行保兑行unit pricepartial shipment transshipmentprice termscarrying vessel mechanismclean creditnon-trade settlement revocable credit irrevocable credit confirmed creditleading bankdouble assurancesight creditusance creditcapital turnoverface valuetransferable creditnon-transferable credit middlemannon-draft creditdeferred payment revolving credittake delivery of commissiondiscountshipping markssignaturein general termsmemos(memorandum) consignorcarriageconsigneenotify partyairway billcargo receiptthe insuredcurrencycommercial invoiceport of shipmentshipping advicenatural product provinces carriercommon carrier 单价分批装运转船价格条款，价格术语运载船只，载货船只机制光票信用证非贸易结算可撤销信用证不可撤销信用证保兑信用证主要银行双重保障即期信用证远期信用证资金周转面值可转让信用证不可转让信用证中间人无汇票信用证推迟付款循环信用证提（货）佣金折扣唛头，运输标记签字用概括性的词语，用一般性词语表达备忘录，便笺托运人运输收货人被通知人空运提单铁路运单，货运收据被保险人货币商业发展发货港，起运港装船通知产品自然领域承运人，运载工具公共承运人contract carrierprivate carrier entrepreneurintermediate product finished productsper-unitshipperinventoryjust-in-time inventory logisticscost economiesintermediate products insurerenterprisepoolpremiumclaimclientmarginhandmaidenknown premiumrelease of fundstime lagunderwritersutmost good faithport of originbrand-newplatinumindemnitytie upcontributionpro rateFord carpercentagesubrogationnegligentforwarding charges proximate cause of the loss insurable interestthe capital tied up exchange rategold standardpar valuereserve currency 契约承运人自有承运人企业家，业主中间产品制成品每一单位托运人，发货人，货主存货，库存零库存物流节约成本，成本节约中间产品承保人企业，公司统筹的资金；共同款项保险费索赔顾客，主顾保证金起服务（或辅助）作用的事物已知的保险费腾出资金在时间上的间隔保险公司最大诚信货物原产地港口崭新的白金损失赔偿占用，冻结分摊按比例（美国）福特轿车百分比；（全部中的）所占比例：部分代位；取代疏忽的，玩忽的交货费用导致损失的直接原因可保险权益占用的资金汇率，兑换率金本位制平价储备货币interactionclean floatdirty floatvice versaspecial drawing right BOP deficitdiscount rateidle fundsdirect quoteindirect quotebuying rateselling ratemedial ratemultilateralfinancial resources earningsspell outcriterionsubscription replenishments prerequisitepopulation-planning nutritioncornerstonecapital marketborrowing powergold tranchereservegrace periodprivate sectorequity investmentcut across sectoral lines standby arrangement investment returns beveragetunacannerybiogeneticsbiotechnology Volkswagencustomer mobility inventorytax holidayacquisition 交互作用清洁浮动肮脏浮动反过来也是这样，反之亦然特别提款权国际收支赤字贴现率邮资（汇率）直接标价（汇率）间接标价买入价卖出价中间价多边的，多国（或多方）参加的资金收益，赢利详细说明，明确规定标准，准则捐助，认捐补充或增加的（资金）必备条件，先决条件人口计划营养基石资本市场借款权黄金份额储备金，准备金优惠期，宽限期私营经济股权投资超越部门界限备用（信贷）安排投资收益，投资回报饮料金枪鱼罐头食品厂生物遗传学生物工艺学大众汽车客户流动存货免税期并购start from scratchjoint ventureparentthe greenfield strategyinvestorsecuritiesstatuteequitiesindicesgilt-edged stocksbrokerjobbersecondary capital marketmarket floorlisted marketincome taxqualificationsstanding committeecriteriaVATshortfallpractitionerlong-term capitalprimary capital raisingoptionsaccession tobe traced back tocontroversyframeworkGeneralized System of Preferences non-discriminatepredecessorfull employmentthe most-favored nation clause trade-relatedfull-fledgedverdicttariff concessionroundinstitutional strengththresholdcounter-veiling measuresanti-dumpingnational treatment 白手起家，从零开始合资企业母公司，总公司，创始组织绿地战略投资者有价证券法令，法规，成文律（股息不定的）普通股，股票（index的复数形式）指数金边证券经纪人，中介人，掮客股票买卖经纪人二级资本市场交易场地挂牌证券交易市场所得税资格常务委员会（criterion的复数形式）标准增值说（全称为value added tax）亏空，不足开业者长期资本对新发行的有价证券的筹措活动期权（合同），选购权加入追溯到争议，争论框架，机构普惠制不加区别的，非歧视的前任，原来的事物充分就业最惠国条款与贸易有关的完全合格的，名副其实的裁决，判决关税减让回合制度力量，行政力量门槛，开端反贴补措施反倾销国民待遇tariff quotafair tradeECOSOCforumterms of tradeescape clausesterritoryaction programmepreferential customs tariffsorganconferencepreferencenon-discrimination principledifferential treatment new international economic ordertransfer of technology 关税配额公平贸易联合国经济及社会理事会公开讨论的机会；论坛贸易条件免责条款，例外条款领土，领地行动纲领特惠税机构，机关（正式）会议（年会）优先（权）；优先选择（权）无差别待遇原则差别待遇国际经济新秩序技术转让。

网上订餐系统外文翻译参考文献综述

网上订餐系统外文翻译参考文献综述毕业设计(论文)外文资料翻译系：计算机系专业：计算机科学与技术姓名：学号：(用外文写)外文出处：JAVA2MicroEditionandtheWorldofJAVA[EB/OL].l附件：1.外文资料翻译译文；2.外文原文。

签名：年月日注：请将该封面与附件装订成册。

附件1：外文资料翻译译文J2ME和JAVA领域1.介绍20世纪70年代以来随着计算机革命的开始，对计算机先进软件的需求大大增加，从而可以充分利用功能日益增强的精密的计算机的处理数据的能力。

C编程语言逐渐成为支柱，使程序员开发软件像计算机运行一样流畅。

80年代以来，程序员又目睹了编程语言领域的又一次变革的高潮。

C语言的编程能力已经不能满足计算机的技术发展的需要。

这问题并不是新问题。

它造成了一代又一代的编程语言的新老更替。

问题是，它使得程序设计过于复杂，从而使计算机软件的设计，编写和开发落后于硬件的发展。

就是这个时候，两种基于设计概念的编程语言Simula67和Smalltalk（从上世纪60年代末）带来了接近编程语言未来前景的循序渐进的步骤。

这期间，当面向对象编程（OOP），与它一种新的编程语言，所谓的C++在程序员中掀起了一场风暴。

1979年，BjarneStroustrup的在新泽西州的贝尔实验室增强了C语言，使其具有面向对象的特点即所谓的C++语言(++是C编程语言增强的承载符号)。

C++是一个真正的提高的C编程语言，它开始是一种前置语言，该计划最初是一种编译工具。

Stroustrup建立类的概念（借用了Simula67和Smalltalk中的概念），由类则可以创建实例对象。

一个类包含数据成员和定义对象数据和功能的成员函数。

他还介绍了继承的概念，使一类继承其他一个或多个类的部分或全部数据成员或成员函数，职能由一个或多个其他类别-所有这些概念就是面向对象的编程。

1988年由ANSI官员将C++标准化。

高英第二册修辞汇总

高级英语第二册修辞汇总1. It is easier to make a beautiful dumb girl smart than to make anugly smart girl beautiful. (antithesis)2. The children went from adult to adult like buckets in a fire brigade. (simile)3. Instantly, from the dark holes all round, there was a frenziedrush of Jews. (transferred epithet)4. Still, a white skin is always fairly conspicuous. (synecdoche)5. I leaped to my feet, bellowing like a bull. (simile)6. After the war, it was only natural that hopeful young writers, their minds and pens inflamed against war, Babbittry, and “Puritanical ” gentility, should flock to the traditional artistic center. (metonymy)7. The conversation was on wings. (metaphor)8. United, there is little we cannot do in a host of co-operative ventures. Divided, there is little we can do, for we dare not meet a powerful challenge at odds and split asunder. (antithesis)9. But we shall not always expect …to remember that, in the past,those who foolishly sought power by riding the back of the tiger endedup inside.(metaphor)10. Polly, I love you. You are the whole world to me, and the moon andthe stars and the constellations of outer space. (hyperbole)11. Greenwich Village set the pattern.(metonymy)12. Naturally, the spirit of carnival and the enthusiasm for high military adventure were soon dissipated once the eager young men had received a good taste of twentieth century warfare. (metaphor)13. The hurricane tore three large cargo ships from their moorings and beached them. (personification)14. The hurricane seized a 600,000-gallon Gulfport oil tank and dumped it 3 miles away. (personification)15. Long lines of women,bent double like inverted capital Ls, work their way slowlyacross the fields. (simile)16. The glow of the conversation burst into flames. (metaphor)17. If a free society cannot help the many who are poor, it cannot savethe few who are rich. (antithesis)18. But this peaceful revolution of hope cannot become the prey of hostile powers. (metaphor)19. …yet both raci ng to alter that un certa in bala nee of terror thatstays the hand of mankind 's final war. (synecdoche)20. I said with a mysterious wink and closed mybag and left. (transferred epithet)21. … , an attempt to treat the worker and employee like a machine which runs better when it is well oiled. (simile)22. The slightest mention of the decade brings nostalgic recollectionsto the middle-aged and curious questionings by the young. (transferred epithet)23. The wind sounded like the roar of a train passing a few yards away. (simile)24. Even with the most educated and the most literate, the King 's English slips and slides in conversation. (alliteration & simile)25. Younger brothers and sisters of the war generation had suffered no real disillusionment or sense of loss, now began to imitate the manners of their elders and play with the toys of vulgar rebellion. (metaphor)26. And so, my fellow Americans ask not what your country can do for you; ask what you can do for your country. (antithesis)27. And let every other power know that this hemisphere intends to remain the master of its own house. (metaphor)28. The war acted merely as a catalytic agent in this breakdown of the Victorian social structure. (metaphor)29. A momentlater, the hurricane, in one mighty swipe, lifted the entire roof off the house and skimmed it 40 feet through the air. (personification)30. …,and blow ndow n power lines coiled like black spaghetti over the roads.(simile)31. …, and then more infantry, four or five thousand menin all, winding up the road with a clumping of boots and a clatter of iron wheels. (onomatopoeia)32. No one has any idea where the conversation will go as it meanders or leaps and sparkles or just glows. (metaphor)33. Let the word go forth from this time and place, to friend and foealike, ...(alliteration)34. that the torch has been passed to a newgeneration of Americans, born in this century, tempered by war, disciplined by a hard and bitter peace, ...(parallelism)35. One more chance, I decided. But just one more. There is a limit to what flesh and blood can bear. (synecdoche)36. My brain was as powerful as a dynamo, as precise as a chemist 's scales, as penetrating as a scalpel. (simile & hyperbole)37. There follows an informal essay that ventures even beyond Lamb 's frontier. (metaphor)38. Before long the movement had become officially recognized by the pulpit (which denounced it). (metonymy)39. So let us begin anew, remembering on both sides that civility is not a sign of weakness, and sincerity is always subject to proof. (antithesis)40. To our sister republics south of our border, we offer a special pledge: to convert our good words into good deeds, in new alliance for progress, to assist free menand free government in casting off the chains of poverty. (repetition)常见成语汉译英1. 爱屋及乌Love me, love my dog.2. 百闻不如一见Seeing is believing.3. 比上不足比下有余worse off than some, better off than many; to fall short of the best, but be better than the worst.4. 笨鸟先飞 A slow sparrow should make an early start.5. 不眠之夜white nightshort; 6. 不以物喜不以己悲not pleased by external gains, not saddened by personnal losses7. 不遗余力spare no effort; go all out; do one's best8. 不打不成交No discord, no concord.9. 拆东墙补西墙rob Peter to pay Paul10. 辞旧迎新bid farewell to the old and usher in the new; ring out the old year and ring in the new11. 大事化小小事化了try first to make their mistake sound less serious and then to reduce it to nothing at all12. 大开眼界open one's eyes; broaden one's horizon; be an eye-opener13. 国泰民安The country flourishes and people live in peace14. 过犹不及going too far is as bad as not going far enough; beyond is as wrong as falling too much is as bad as too little15. 功夫不负有心人Everything comes to him who waits.16. 好了伤疤忘了疼once on shore, one prays no more17. 好事不出门恶事传千里Good news never goes beyond the gate, while bad news spread far and wide.18. 和气生财Harmony brings wealth.19. 活到老学到老One is never too old to learn.20. 既往不咎let bygones be bygones21. 金无足赤人无完人Gold can't be pure and man can't be perfect.22. 金玉满堂Treasures fill the home.23. 脚踏实地be down-to-earth24. 脚踩两只船sit on the fence25. 君子之交淡如水the friendship between gentlemen is as pure as crystal; a hedge between keeps friendship green26. 老生常谈词滥调cut and dried, clich e27. 礼尚往来Courtesy calls for reciprocity.28. 留得青山在不怕没柴烧Where there is life, there is hope.29. 马到成功achieve immediate victory; win instant success30. 名利双收gain in both fame and wealth31. 茅塞顿开be suddenly enlightened32. 没有规矩不成方圆Nothing can be accomplished without norms or standards.33. 每逢佳节倍思亲On festive occasions more than ever one thinks of one's dear ones far away.It is on the festival occasions when one misses his dear most.34. 谋事在人成事在天The planning lies with man, the outcome with Heaven. Man proposes, God disposes.35. 弄巧成拙be too smart by half; Cunning outwits itself36. 拿手好戏masterpiece37. 赔了夫人又折兵throw good money after bad38. 抛砖引玉 a modest spur to induce others to come forward with valuable contributions; throw a sprat to catch a whale39. 破釜沉舟cut off all means of retreat ；burn one ‘s own way of retreat and be determined tofight to the end40. 抢得先机take the preemptive opportunities41. 巧妇难为无米之炊If you have no hand you can't make a fist. One can't make bricks without straw.42. 千里之行始于足下a thousand-li journey begins with the first step--the highest eminence is to be gained step by step43. 前事不忘后事之师Past experience, if not forgotten, is a guide for the future.44. 前人栽树后人乘凉One generation plants the trees in whose shade another generation rests.One sows and another reaps.45. 前怕狼后怕虎fear the wolf in front and the tiger behind hesitate in doing something46. 强龙难压地头蛇Even a dragon (from the outside) finds it hard to control a snake in its old haunt - Powerful outsiders can hardly afford to neglect local bullies.47. 强强联手win-win co-operation48. 瑞雪兆丰年 A timely snow promises a good harvest.49. 人之初性本善Man's nature at birth is good.50. 人逢喜事精神爽Joy puts heart into a man.51. 人海战术huge-crowd strategy52. 世上无难事只要肯攀登Where there is a will, there is a way.53. 世外桃源 a fictitious land of peace away from the turmoil of the world;54. 死而后已until my heart stops beating55. 岁岁平安Peace all year round.56. 上有天堂下有杭Just as there is paradise in heaven, ther are Suzhou and Hangzhou on earth.57. 塞翁失马焉知非福Misfortune may be an actual blessing.oneself 58. 三十而立 A man should be independent at the age of thirty.At thirty, a man should be able to think for himself.59. 升级换代 updating and upgrading (of products)60. 四十不惑 Life begins at forty.61. 谁言寸草心报得三春晖 Such kindness of warm sun, can't be repaid by grass.62. 水涨船高 When the river rises, the boat floats high.63. 时不我待 Time and tide wait for no man 。

Switched Reluctance Motor Drives-Dr. Iqbal Husain-The University of Akron

Switched Reluctance Motor Drives: Basics and Reseeach TrendsDr. Iqbal Husain Department of Electrical Engineering The University of AkronAkron, OH 44325OVERVIEWMOTOR DRIVES: IN GENERALMAIN FEATURES OF SRMSRM STRUCTUREOPERATION OF SRMSRM CONVERTERSCONTROL OF SRMSRM PROJECTS AT AKRON¾SRM MODELING¾RADIAL FORCE AND ACOUSTIC NOISE ¾SENSORLESS CONTROLAPPLICATION OF SRMCONCLUSIONSMOTOR DRIVES: IN GENERAL The dc machine has been the primary choice for the servo applications, because of their excellent drive performance and low initial cost.The advantages of the ac machine to the dc machine are in the areas of torque-inertia ratio, peak torque capability and power density. Also ac machines do not need commutators and brushes.The low cost, ruggedness and almost maintenance free operation of the induction machines have made it the workhorse of the industry.The different types of synchronous motors are used because of the high level of accuracy that can be achieved in speed control.In low power applications, the permanent magnet (PM) synchronous motors are extensively used for their high efficiency and good performance.The simplicity in both motor construction and power converter requirement made the switched reluctance motor (SRM) an attractive alternative to the induction motor and the PM motors in adjustable speed drive applications.BASIC CONSTRUCTIONOF AN SRMThe SRM is a doubly-salient, singly-excited machine with independent windings of the stator.Its stator structure is same as PM motor, but the rotor is simpler having no permanent magnet on it.Stator windings on diametrically opposite poles are connected in series or parallel to form one phase of the motor.Several combinations of stator and rotor poles are possible, such as 6/4 (6 stator poles and 4 rotor poles), 8/4, 10/6, 12/6 etc.4/2, 2/2 configurations are also possible, but with these it is almost impossible to develop a starting torque when the stator and rotor poles are exactly aligned.The configurations with higher number of stator/rotor pole combinations have less torque ripple.The design objectives are to minimize the core losses, to have a good starting capability and to eliminate mutual coupling.i aAA ′i ai b BB ′i bC i c C ′i cDD ′i di d (STATOR)i aAA ′i ai bBB ′i bC i c C ′i cDD ′i di dSRM ConfigurationsDepends on:¾Number of stator/rotor poles ¾Number of phases¾Number of repetitions¾Connections of the stator windings (series or //) Common Configurations:¾6/4 (6 stator poles/4 rotorpoles), 3 phases, 1 rep.¾8/6, 4 phases, 1 rep.3-PHASE SRM WITH REPETITIONSConstraints for rotor and stator pole arcs :¾Minimum size such that the motor can produce torque in either direction for any rotor position¾Maximum size such that flux is present in only one rotor pole when stator poles are energized B and B qN s r r≥2πB B N s r r+≤2πPole arcswithin range Pole arcs too large Rotor arcs too small¾The two constraints on the arc widths limit the size of the arc widths within a defined area limited by the min. and max. arc widths.¾The practical area is further limited to the lower half triangle where the rotor pole arcs are larger than the stator pole arcs.FEATURES OF SWITCHEDRELUCTANCE MOTOR (SRM)ADVANTAGESThe rotor does not have any windings, commutators, brushes or cages.The torque-inertia ratio is high.It provides high reliability, wide-speed range at constant power, low manufacturing cost, fast dynamic response, ruggedness and fault-tolerance.No shoot-through and crossovers in the converter.The maximum permissible rotor temperature is higher since there is no permanent magnet.Open-circuit voltage and short-circuit current at faults are zero or very small.DISADVANTAGESDoubly-salient structure causes vibration and acoustic noise.SRM OPERATION (PHASE-A EXCITED)AA′BB′CC′D D′V s Phase-APhase-BPhase-CPhase-DSRM OPERATION (PHASE-B EXCITED)AA′BB′CC′D D′V s Phase-APhase-BPhase-CPhase-DSRM OPERATION (PHASE-C EXCITED)AA′BB′CC′D D′V s Phase-APhase-BPhase-CPhase-DSRM OPERATION (PHASE-D EXCITED)AA′BB′CC′D D′V s Phase-APhase-BPhase-CPhase-DPOLE ALIGNED POSITIONi aAA ′i ai bBB ′i bCi cC ′i cDD ′i di di aAA ′i ai bBB ′i bCi cC ′i cDD ′i di dPOLE UNALIGNED POSITIONAA ′BB ′CC ′DD ′L aL uI n d u c t a n c eAA ′BB ′CC ′DD ′L aL uI n d u c t a n c eAA ′BB ′CC ′DD ′L aL uI n d u c t a n c eSRM NonlinearCharacteristicsThe nonlinear saturating characteristics of real magnetic steel has a marked influence on the energy conversion process in an SRM.Only for very low values of saturation, the characteristics approximate the ideal linear case.The flux-current characteristics in the unaligned position is approximately linear because the magnetic path is dominated by large airgap and flux densities are small.In the aligned position the airgap reluctance is small and flux density is high, which causes high saturation at higher currents.VOLTAGE BALANCE EQUATION AND TORQUE PRODUCTIONdt),i (d ir v θλ+=The voltage-balance equation for one phaseAssuming a linear relationship between phase flux and current i.e. λ=Li and neglecting the resistive drop∫=′∂′∂==i.const i di W W T 0λθElectro-mechanicalTorqueThe nonlinear machine torque is derived from θd dL iT 221=SRM TORQUE PRODUCTIONMotoringmodeGenerating modeθd dL.i .21T ,Torque 2ph =Aligned positionL aRotor positionUnaligned positionL uI n d u c t a n c eInductance profiles with the rotor position.CONDUCTION SEQUENCEFig. (a) Idealized inductance profile for one motor phase; (b) Phase energization for motoring torque; (c) Phase energization for generating torque; (d) ElectromagneticTorque.Rotor position, θθcθoL(θ)S RR SRL a(a)TRotor position, (d)+ve Torque Motoringiθoθc(b)Rotor position, θRotor position, θ(c)i-ve Torque GeneratingCHARACTERISTICS#1#2#3Rotor Speed (Per Unit)1243Torque (Per Unit)1Constant Torque RegionConstant Power Region Constant Power*Speed RegionRegion #1: Constant TorqueCurrent, and hence torque, kept constant by PWM or chopping.At low speeds current rises instantaneously due to small back-emf.At medium speeds, phase advancing isnecessary. Phase turn-off is also advanced so that current decays to zero before rotor passes alignment. PWM or chopping is still possible.CHARACTERISTICS (Cont.)Region #2: Constant PowerHigh back-emf forces current to decrease once pole overlap begins.PWM or chopping no longer possible.Conduction angle is increased in proportion to speed, primarily through phase advancing.Maximum current can still be injected into the motor to sustain high enough torque.Core and windage losses increase rapidly.Constant power can generally be maintainedupto2-3 times the base speed.Region #3: Natural characteristicsUpper limit of conduction angle is reached when equals half the rotor pole-pitch., i.e., half theelectrical cycle at the onset of region #3.Conduction angle is fixed, but pulse position ca be advanced.Maintaining torque production is no longer2CONVERTERSThe torque is independent of the direction of current ⇒unipolar converters (bi-directional for the voltage and unidirectional for the current) are sufficient.Unidirectional in current and independent phases ⇒wide variety of converters possible.The choice depends on the requirements of the application and the configuration of the SRM used.CLASSIC BRIDGE CONVERTERV dcA-+i ph(b)S 1D 1S 2D 2D 1V dc A-+i ph(c)S 1D 2S 2D 1V dc A-+i ph(a)S 1S 2D 2Application of (a) +ve voltage,(b) zeroV dc ABCD-+Classic bridge power converter.-+-+C 1C 2V dc /2BDAV dc-+CV dc /2Split -Capacitor ConverterA voltage of V dc /2 is applied to each motor phase. Requies an even number of phases, but has only one switch per phase.The currents in the winding must be balanced to avoid charge unbalance at the capacitor midpoint. Swithces require 2.V dc rating Total switch kVA rating is 2.V dc .IL 1Q1CdDd1Dd2Dd3L2L3Q2Q3QdD cLQ4d4D4D d+ -VdcL dL1Q 1CdDd1D d2Dd3L 2 L3Q 2 Q 3QdDcLQ 4d4D4D dD b+ - VdcEnergy Efficient ConvertersUtilizes a buck converter concept to return residual magnetic energy to the source.Offers full-regeneration capability with reduced number of switches.CONTROLSControl StrategiesAppropriate positioning of the phase excitation pulses is the key in obtaining effective performance Control parameters: θon, θdwel and IphControl parameters determine torque, efficiency and other performance parameters.Different Control Methods Volatge controlled drives. Current controlled drives. Advanced controllers: T/A or efficiency Maximization. Torque ripple minimization. Acoustic Noise Minimization. Sensorless controllers.BASIC CONTROLSDuty Cycle Gate Signalωref+ Outer Loop ControllerVdc VphV*PWM ControllerElectronic CommutatorConverterSRMωAngle θ Calculator offθonθd/dtVoltage Controlled Drive In low performance drives, a fixed frequency PWM voltage control with variable duty cycle provides the simplest form of control. The angle controller generates the turn-on and turn-off angles depending on the rotor position. The duty ratio is changed according to the voltage command signal. A speed feedback loop can be added on the outside, if speed control is desired. The drive typically also incorporates a current sensor, placed in the lower leg of the dc bus, for over-current protection.BASIC CONTROLSVdcω/θref+ -Outer Loop ControllerTorque ControllerCurrent ControllerGate SignalConverterSRθon ω/θSign(.) Angle Calculator θoff Electronic CommutatorθCurrent Controlled Drive Used in torque controlled drives, where current is controlled in the inner loop. The controller needs current feedback information from each phase. The reference current is set by the torque command and the torque-angle-current characteristics of the motor. The method allows rapid resetting of the current level and has applications where fast motor response is required.SRM RESEARCH TRENDSControls Optimization• fficiency Maximization • /A Maximization. • orque Ripple Minimization.Indirect Position Sensing• odel Based • ctive ProbingSelfTuningConvertersDesigns• ptimization • M-SRM CombinationSRM RESEARCH PROJECTS AT AKRONSRM Controls • • • • Torque ripple minimization over a wide speed range Torque ripple minimization with indirect position sensing T/A maximization with indirect position sensing Controllers for automotive applications.Indirect Position Sensing • Sliding mode observer based position estimation. Self-Tuning • On-Line parameter adaptationSRM RESEARCH PROJECTS AT AKRON (Cont.)Modeling and Design • • • • • Radial force calculation and acoustic noise prediction. SRM design for low-acoustic noise applications. SRM design for wide-speed range applications. SRM design for electric vehicle and automotive applications. Fault analysis and excitation requirements for SR starter-generators.Converter Topology • Energy efficient C-dump converters.SRM MODELING FOR ANALYSIS AND DESIGN The phase flux linkage λph is split into two separate fluxes λm referred to as the main flux linkage, and λf referred to as the fringing flux linkage.λ ph = λm + λ f .Stator yokeSlotFringing-flux λf Main-flux λm hs gm Pole nonoverlap region Pole overlap regionSlotls =hs+hr+gmStator poleEffective rotor yokeRotor polehr(PW-Rg⋅θ)Rotor yokeRg⋅θFig. : The flux linkage components during poleoverlap.RADIAL FORCE AND ACOUSTIC NOISE PREDICTION• Noise sources in electric machines: Magnetic, mechanical, electrical and aerodynamic. Radial vibration of stator induced by radial magnetic force is the main source of acoustic noise.••Radial vibration along the circumference o the stator causes various mode-shapes having their own natural mode-frequencies depending on the machine geometry and material properties. Radial magnetic force excites the machine at various frequencies depending on the speed and the geometry.••SRM is noisiest when harmonics of the magnetic radial force and the natural mode frequencies coincide to form resonance.ANALYSIS OF RADIAL FORCE • The co-energy Wm′ ( i p ,θ ) due to the fringing flux λm is′ W m (i p ,θ ) =ip∫0λ m ( i p ′ , θ ) di p ′• The radial forces on the two sets of rotor and stator poles can be calculated independently as ∂W m′ F1m = ∂g • The net radial force in one of the pole pair isFnet = F1m + F1 f• The force in the non pole-overlapping region is calculated using a linear model.METHOD OF NOISE ANALYSISMachine Geometry and Material PropertiesNatural ModeFrequencies and ModeShapesReference Speed and Load TorqueSRM Model and ControllerModel for Magnetic Radial ForceFrequency and Time Domain AnalysisResonant ModeShape and FrequencyMagnitu & Exten of Acousti NoiseFig. : Flow diagram of the proposed acoustic noise prediction-model.CIRCUMFERENTIAL MODE SHAPESAND FREQUENCIESm=0m=1m=2m=4m=5 m=3Fig. : Various circumferential mode-shapes of the stator of the SRM.TIME DOMAIN ANALYSIS0:t 01:t 19:t 9Time (Second)R a d i a l f o r c e (N ) a n d M a g n o m o t i v e f o r c e (N I )F radial (t)I p (t)*1000.080.0850.090.095-4000-200002000400060000.12:t 28:t 8QF r (N)NI (5 amp turn)m=4m=2Fig. 1. The mode shapes with m=2 and 4.Arrows inwards for-F r (-ve)Arrows outwards for-F r (+ ve)Fig. : Time-domain plot of radial force with rotor position.ACOUSTIC NOISE INTENSITY50010001500205001000150020002500F r (f p )F r (7f p =f m(=2)I n t e n s i t y o f t h e r a d i a l f o r c e (N )Frequency (Hz)Fig. : Time-domain plot of radial force with rotor position.Excitation frequency (Hz)60800500100015000.000.00500.0100100250750125070900.00250.0075Fig. : Noise intensity with excitation frequency.C i r c u m f e r e n t i a l d e f l e c t i o n (m )A c o u s t i c n o i s e (dB )@ f m(=2) = 758.54 HzSRM DESIGN FOR LOW-NOISEAND WIDE-SPEED RANGEMagnetic radial force excites various circumferential mode shapes of the stator.The stator then resonates with damped vibration and radiates acoustic noise into the air.The noise becomes significant whenever any harmonics of the radial force resonate with the stator mode frequency within audible range.Radial force, mode frequency and noise level are all functions of machine geometry.An SRM can operate over a wide-speed range with low torque-ripples only with efficient sharing of torque between adjacent phases.The torque sharing capability is determined by two critical rotor positions.These critical rotor positions depend on the machine geometry.Therefore, an appropriate design is necessary to minimize acoustic noise and maximize torque-speed range of an SRM.DESIGN STEPSSelections SizingStartSpecifications: Torque, speed etc.Static PerformancesDynamic PerformancesOutput ChecklistOrChecklist satisfactory?YesNoPerformance satisfactory?YesNoFEA satisfactory?YesNoFinite Element AnalysisEndFinal outputsFig. 1. Flowchart of SRM design steps.LOW NOISE DESIGN:PARAMETERS AFFECTINGNOISE12345 Fig. 2. Cause-effect diagram of acoustic noise generation in the SRM. The design objective is to maximize the dominant mode frequencies and to minimize harmonic components of radial force.OPERATINGCHARACTERISTICS Fig. 11. Torque-speed characteristics plots.NEED FOR POSITION FEEDBACKNEED FOR POSITION FEEDBAC•To produce useful torque formechanical rotation in a desireddirection phase conduction sequence must be synchronized with the rotorposition.•Synchronization of phase conduction necessitates the use of shaft-mounted encoder or resolver forobtaining instantaneous rotorposition information.WHY SENSORLESS OPERATION •Use of discrete position sensor adds cost and complexity to theoverall drive system.•May be unreliable in harshenvironment and cost increasesdrastically for high resolutionsensors.•SRM shows high potential for sensorless operation even atzero speed, since itsinductance/flux varies inaccordance with the rotorposition.BASIS OFSENSORLESS ALGORITHMInductance Based Methods:Applying a probing voltage pulse of magnitude V volts and duration T seconds.Flux Based Methods:Integration of the flux-inducingvoltage to obtain flux of the j th phase as()dt di L V =()∫−=dtR i v j j j j λ。

电主轴专业术语英语

电主轴专业术语英语Electric spindle, also known as Motor spindle, is a professional term in the field of numerical control machine tools, referring to a new technology that integrates the spindle of the machine tool with the spindle motor. This transmission structure combines the spindle motor and the machine tool spindle into one, enabling the spindle components to be relatively independent from the transmission system and overall structure of the machine tool. Therefore, it can be made into a "spindle unit", commonly known as "Electric spindle" or "Motor spindle".The main characteristics of Electric spindle include high speed, high precision, low noise, and an inner ring with a locking port that is more suitable for spray lubrication. This technology has become the best choice for spindle units in high-speed micro-cutting systems, as it can reduce noise and vibration, improve dynamic balance, and meet requirements for lightweight, small inertia, and compact structure.In the field of numerical control machine tools,Electric spindle is widely used in high-speed cutting, grinding, drilling, and other machining processes. Its high speed and high precision characteristics make it possibleto achieve efficient and accurate machining of various materials, including metals, plastics, composites, and more. In addition, the low noise and low vibrationcharacteristics of Electric spindle also contribute to improving the working environment and reducing operator fatigue.The structure of Electric spindle typically includes a spindle body, a motor, a bearing system, a cooling system, and other components. The spindle body is the main component that supports the rotation of the workpiece or tool, and is usually made of high-precision materials such as ceramics or high-speed steel. The motor is the driving force of the spindle, and its performance directly affects the speed and torque of the spindle. The bearing system ensures the stability and accuracy of the spindle rotation, and the cooling system keeps the spindle running at aconstant temperature to prevent thermal deformation.In the design and selection of Electric spindle, it is necessary to consider various factors such as machining requirements, machine tool specifications, and working conditions. For example, the speed and torque of thespindle need to match the material and thickness of the workpiece, the cooling system needs to be able toeffectively dissipate heat generated during high-speed rotation, and the bearing system needs to have sufficient stiffness and damping to reduce vibration and improve machining accuracy.In addition to the basic structure and design considerations of Electric spindle, there are also some advanced technologies and trends in this field. For example, the development of high-power density motors and high-precision bearings has enabled the further improvement of spindle speed and accuracy. At the same time, theapplication of new materials and manufacturing processeshas also helped to reduce the weight and inertia of the spindle, improve its dynamic balance and stability.In summary, Electric spindle is an important component of high-speed and high-precision machining systems, and its performance and quality directly affect the efficiency and accuracy of machining. With the continuous development of technology and the improvement of manufacturing processes, Electric spindle will continue to evolve and improve, meeting the increasing demands of modern manufacturing industry for higher speed, higher precision, and more efficient machining.。

英语题库——精选推荐

1、当在港区慢速航行时，任何船都不得超过限制航速。

考点：固定搭配be permitted to 被允许A.assume 假设B.appreciate 欣赏，感激C.promise 承诺2、船上使用的地名应是在海图或航路指南中使用的那些。

（应使用海图或航路指南中的地名）3、航路指南通过补篇（三年一次）保持最新。

4、在英版航路指南中，stripe用来形容横纹或斜纹。

5、每一个对航路指南的补充都将取消前面的一个。

6、英版航路指南详细描述海图的细节和安全航行所包含的信息。

7、你可以在潮流表中找到平潮的持续时间。

8、航路指南包括了各地的洋流信息。

9、海岸线在雷达上显示出的位置线是一条圆弧。

10、一瓶拖轮在协助海轮靠码头时，对拖轮而言最大的危险就是被锚爪勾住。

11、当一艘船第一次进入A港，并且有一名引航员指挥操纵。

当船长不确定引航员正在采取足够的行动以防止碰撞时，船长应该怎么做？建议一个可供选择的行动，如果不被采取可解除这位引航员。

12、不妨碍他船通过是避免避碰的行动。

考点：be relieved of 解除13、after dropping the pilot的意思是：当引航员离开本船后14、互光灯（明暗光）是灯亮的时间比灯暗的时间长的一种灯质。

15、被长短粉红色虚线围闭的区域说明是渔网区。

16、由于并不是所有的特征都标识在海图上，所以其附近的船舶需要尤其注意。

17、被要求关注一个事实：在许多情况下，海图水深本减少到1拓。

18、被要求关注一个事实：在许多情况下，管道不被掩埋和海图水深被减少可能高达2米。

19、桥梁上的净空表标志水面到桥梁底部的距离。

20、穿越影响航行的沙洲的最佳时间是平潮。

21、Wk.=wreck 沉船22、随着时间的推移，这些地区的水面航行并不及正常危险，但对于抛锚、捕鱼或者任何形式的潜艇或海底活动依然存在着实际危险。

23、出现一段时间的乳白天空，你会怎样认为？无法估算距离。

24、在夏令时期间，用于测定时间的子午线更东一些。

航空飞机气动通用系统英文培训课件-

♦ Compared t o o t h e r modes of t r a n s p o r t , o f f i c e buildings
and o t h e r enclosed spaces occupied by l a r g e numbers of people, today"s j e t l i n e r s provide an environment th i s s u p e r i o r i n many r e s p e c t s . For example, i n the heating and cooling seasons, most o f f i c e buildings provide a far lower percentage of outside a i r - - often a low as 20 percent or even l e s s . In a d d i t i o n , buildings t y p i c a l l y have a much lower a i r - change r a t e , and they"re seldom equipped with high-efficiency f i l t e r s l those found in airplanes.
♦ The cooled a i r then flows t o a chamber where i t i s
mixed with an approximately equal amount of highly f i l t e r e d a i r from t h e passenger c a b i n . The combined outside and f i l t e r e d a i r i s ducted to the cabin and distributed through overhead outlets.

航海英语听力与会话评估

航海英语听力与会话大证评估Chapter 1口述1. Please say something about your hometown.a) The geographical position, population, and features of your hometown.b) The environment and customs of your hometown.c) The specialties of your hometown.Nanjing is my hometown. It is the capital of Jiangsu Province. The Yangtze River runs through it. It has a long history of 2400 years. It is known as one of the six ancient capital cities in China. Since the 3rd century, about ten dynasties have made it their capital. In Nanjing, spring and autumn are short. In summer, it is very hot. There are many famous places in Nanjing, such as Xuanwu Lake, Confucius Temple, Dr. Sun Yat-sen’s Mausoleum, etc. People in Nanjing are industrious and hospitable. Welcome to Nanjing!2. Please say something about yourself.a) Your name, age, rank, working experiences, hobbies.b) Your daily work.c) Your spare time activities.My name is … I’m … years old. I’m from ... Now I’m studying in Jiangsu Maritime Institute.I major in navigation. I will graduate next year. I have a wide range of interests. I like collecting stamps, and I can learn much knowledge from it .I like playing basketball and listening to music, too. But I don’t like playing football and watching TV. I have many friends.3. Please say something about your family.a) Members of your family.b) Their occupations.c) Their hobbies and characteristics.My name is ... I’m … years old. I’m from ... There are … people in my family. They are ... My grandmother is over … years old, but she is very healthy. My father is a …, he is … years old. My mother is a …, she is ... (years old). They work very hard. I’m studying in Jiangsu Maritime Institute now. We love each other. We live a happy life.4. Your favorite port you have called at.a) A simple introduction of the port.b) Reasons why you like it.c) Anything special about it.I have called at Shanghai harbor and I like it very much. Shanghai is a large seaport. It lies at the mouth of the Yangtze River on the east coast of China. I was impressed by its prosperousness and its size. Everyday a number of ships with imported and exported goodscome in and out of Shanghai harbor. Large vessels of 50 thousand tonnages can enter it freely and the annual shipping volume of Shanghai Harbor has reached about 440 million tons. There are a lot of stevedoring areas and the port has been equipped with all kinds of advanced loading and unloading facilities. Shanghai Harbor is playing an important part in our nation’s shipping industry.5. Please say something about your responsibilities on board.a) Your position on board.b) Your daily work on board.c) Your duties on board.I work as a third officer on M.V. …I do plenty of work on board. During navigation, I stand watches on the bridge and maneuver the ship. In port, I keep the deck watches. Besides, I take charge of the fire-fighting and life-saving appliances and keep them in normal condition. I am also responsible for signaling equipment, the International Code Signal flags and other flags and for maintaining and accounting for all training publications and training aids.问答1. What’s your date of birth?May 1st, 1988 was my birthday.2. What’s your seaman’s book number?XXXX.3. Where are you from?I’m from Jiangsu, China.4. What’s your captain’s nationality?Chinese, I think.5. What do you think is the most important thing on board?Safety.6. Which ports do you often call at?New York.7. What is your favorite TV program?CCTV 5 Sports. /CCTV News.8. What is your favorite Web site?Shoo / yahoo/ Sian/ Baidu/ Google.9. What is your favorite day of the week? Why?Saturday. I can have a good sleep.10. What is your favorite kind of movie?Action film/ Horror film/ Comedy film/ Tragedy film.11. What is your favorite kind of music?Classical / Folk/pop/ Rock and roll music.12. What is your favorite magazine?Readers/Times/ Forum.13. What is the population of your hometown?There are over 5million people in my hometown.14. What is your population of your country?1,300,000,000 (one point three billion people.)15. What is the best thing about your hometown?Dishes/Food.16. What is the worst thing about your hometown?Traffic density/ Dirty environment.17. What’s your hometown like?It looks like a beautiful garden.18. Do you have many disasters in your country which are caused by weather?Yes, there are. Earthquake/ Seaquake/ Typhoon/Flooding.19. What sports do you like to watch on TV?Basketball/ Soccer/ Swimming.20. What do you think is the most popular sport in the world?Basketball/ Soccer/ Swimming.Chapter Two口述1. Say something about how to apply for radio pratique.a) Your ship’s particulars and voyage briefs.b) Crewmembers’ health condition, cargo information and ship’s sanitary conditionat present.c) Some certificates relating to quarantine inspection.First, you must report your ship’s particulars, such as vessel’s name, call sign, draft, tonnage, kind of vessel, the time to arrive at the quarantine anchorage, the departure port, the ports you have called at, destination port and so on.Then you must report the number of the crew members to the quarantine officer, and whether there are sick persons on board. Get rid of rats.Finally you must report some certificates relating to quarantine inspection, such as Vaccination Certificate, De-ratting Certificate, Ship’s Sanitary Certificate and so on.2. Describe the requirements on ship’s seaworthiness in terms of certificates and papers which need to be carried on board.a) List major certificates on board and describe their particulars.b) Categorize those certificates (class certificates, statutory certificates).c) The management of those certificatesMajor certificates on board are Certificate of Vessel’s Registration which contains vessel’s name, port of registry, signal letter and so on; International Tonnage Certificate which covers main dimensions and tonnage; Cargo Ship Safety Construction Certificate which shows the condition of the structure, machinery and equipment; Minimum Safety Manning Certificate which shows whether the ship is safely manned; International Load-line Certificate whichshows it has been marked in accordance with the convention of the International Load-line Certificate and so on.Class ce rtificates are issued by the Vessel’s Classification Association, such as International Tonnage Certificate; but the statutory certificates are issued by the competent government, such as Certificate of Vessel’s Nationality, Certificate of Vessel’s Registr ation and so on.The captain must maintain these certificates well.3. Describe the shipboard customs formalities.a) The main duties of the customs officers.b) Preparations before customs officers come on board.d) Your experiences you have ever had with customs officers.The customs officers are responsible for supervision and control of all cargoes in and out. Seal and unseal the bonded store on board. Check if there any smuggling goods on board. Before customs officers come on board, we must prepare some documents, such as the Captain’s Declaration, the Import Cargo Manifest, two copies of Crew List, three copies of the Stores and Provisions List, the Last Port Clearance and two copies of the Crew Personal Effects List.When customs officers come on board, we must greet them warmly and give them a good cooperation.4. Describe the shipboard immigration formalities.a) The main duties of the immigration officers.b) Preparations before immigration officers come on board.d) Your experiences you have ever had with immigration officers.Immigration officers perform the following duties: determine admission of persons by examining their documents, issue shore-passes, check up the crew members and their seamen’s books.Before immigration officers come on board, we must prepare some documents, such as Crew List, Seamen’s Books, Shore-passes and so on.When immigration officers come on board, we must greet them warmly and do everything to the satisfaction of the immigration officer.5. Describe the shipboard quarantine formalities.a) The main duties of the quarantine officers.b) Preparations before quarantine officers come on board.d) Your experiences you have ever had with quarantine officers.The duties of the quarantine officers are in charge of the jobs relating to sanitation and health, such as checking whether the sanitary condition is satisfactory and whether there are any sick persons or infectious disease on board, especially the cholera, yellow fever and smallpox. Before the quarantine officers come on board, we must prepare some documents, such as Crew List, Crews’ Inoculation Certificate, Maritime Declaration of Health for Departure of Ship, De-ratting Certificate and so on.When the quarantine officers come on board, we must greet them warmly and do everything to the satisfaction of the quarantine officers.问答1. What’s the validity of the Cargo Ship Safety Equipment Certificate?5 years.2. What flag should be hoist when a vessel requires quarantine inspection?Flag Q.3. Can a ship enter a foreign port before quarantine inspection?No, it can’t.4. Why must the customs officer seal the Bonded Store?In order to prevent smuggling.5. Please list 5 ship’s certificates.International Tonnage Certificate, International Load-line Certificate, Vessel’s Registration Certificate, Vessel’s Nationality Certificate, Cargo Ship Safety Equipment Certificate and so on.6. Are cigarettes and liquor exempted from customs duties?No, only 10 packets of cigarettes and 1 bottle of spirits for each crew.7. How can the captain do with the shore passes before leaving a port?Collect the shore passes and hand them to the quarantine officers.8. Which certificate prescribes general requirements for the functions ofradiotelegraphy installation for lifeboat on board?Cargo Ship Safety Radio Certificate.9. Which certificate specifies the freeboard assignment of a ship?International Load-line Certificate.10. Which document demonstrates a ship being in a fit and efficient condition andclassed?Document of Compliance (DOC).11. If your ship needs provisions and/or replenishments, how do you get them?Communicate with the agent or ask ship-chandler to supply .12. Which documents should you show when you go through the customs formalities?The Captain’s Declaration, the Import Cargo Manifest, two copies of Crew List, three copies of the Stores and Provisions List, the Last Port Clearance and two copies of the Crew Personal Effects List.13. Who issues the shore passes to the crewmembers wishing to go ashore?The immigration officer.14.What documents should generally be shown to the quarantine officer?Crew List, Crew’s Inoculation Certificates, Maritime Declaration of Health for Departure of Ship, De-ratting Certificates and so on.15.What documents should generally be shown to the customs officer?The Last Port Clearance, the Import Cargo Manifest, the Crew List, the Stores and Provisions List, the Crew Personal Effects List and so on.16.What documents should generally be shown to the immigration officer?The Crew List, the Seamen’s Books, the shore-passes and so on.Chapter Three口述1. Describe the responsibilities as a watch officer while the ship is at anchor.a) Regular operations for anchor watch.b) Emergency handling in case of dragging.c) Conclusion.Before anchoring, take a hammer, an oil can and some goggles to the forecastle; ask the engine room for power and water on deck and stand by anchor. When anchoring, take off the hawse pipe’s cover and clear the spurling pipes. When the anchor reaches the bottom, hoist the anchor ball or turn on anchor lights. Finally inform the engine room that power and water are finished with. Return all gears.When anchor is dragging, let go another anchor at once. We can also start engine or let go more cables to increase the grabbing power, or heave away the anchor and then let go anchor again.2. Describe the proper way of using VHF.a) How to operate VHF set proper.b) General rules of using VHF.c) Rules of using VHF Channel 16.Before using VHF, make sure your call is really necessary and switch VHF to the correct channel. Don’t interrupt another station’s transmissions.Before speaking, check whether the transmit switch is on. Push the button to speak and release it to listen. Speak slowly and clearly.Channel 16 is only used for distress, safety and urgency. Distress calls have absolute priority over all other communications.3. Describe the procedures before arrival at a port.a) The preparations from the bridge.b) The preparations from the engine room.c) The preparations from the deck.Before arriving at a port, the ship has to communicate with the port and pilot station by VHF, informs her ETA and get the necessary information about draft restrictions, fairway speed, pilotage, weather report, depths of water, tides, etc.Call master onto the bridge to give instructions and monitor the operation of the ship. The engine room prepares to change oil and supply power.The deck crew members are at their different stations, testing the mooring machinery, mooring lines and checking the pressure on fire main, etc. Stand by anchor and mooring lines.4. Describe the procedures before leaving a port.a) The preparations from the bridge.b) The preparations from the engine room.c) The preparations from the deck.Before leaving a port, first decide whether the ship needs tug assistance and make necessary arrangement. Get information on the weather, tides and the movements of the nearby vessels. Switch on and synchronize gyro and repeaters and check headings of magnetic compass and repeaters. Test and turn on the navigational aids. Synchronize ship’s clock. Ensure deck power, telescope and binoculars available and make arrangements for pilot’s embarkation or disembarkation; Ensure charts and navigational publications corrected up-to-date and courses laid off （标出航线）.The engine room prepares to change oil and supply power.The deck crew members are at their different stations preparing for leaving harbor. Test telegraph and ensure main engines ready. Stand by for letting go all lines and heaving away anchor, etc.5. Describe the procedures of pilotage.a) The general procedures for pilot request.b) The preparations for receiving the pilot.c) The general rules for pilotage.Pilotage at most of the ports in the world is compulsory. Before the ship’s arrival, the captain communicates the pilot station by VHF. When you need a pilot, hoist flag “G”. An order for a pilot should be made beforehand.The job to take the pilot on and off the ship is done by the third officer or the duty sailor. They are responsible for the safety of the pilot. A pilot ladder, a heaving line and a lifebuoy, safety net, manropes, and lights should be prepared beforehand. The pilot ladder should be rigged on leeside.The vessel should report the ship’s name, call sign, nationality, types of ship, total number of persons on board, present position, ETA at pilot station, intended route, etc. to the pilot station. The pilot station should confirm the pilot’s boarding time and position, the berthing time, etc When the pilot has boarded, lower flag “G” and hoist flag “H”.问答1.Can you list at least three mooring lines?Yes. Headline, breast line, spring, stern line, back spring, etc.2. What should be prepared before the pilot comes on board?Pilot ladder, safety net, manropes, a heaving line, and lights should be prepared (If the freeboard is greater than 9 meters, a gangway combined with a pilot ladder shall be rigged.)3. What is the maximum speed through the water that your ship can anchor withoutrisking breaking the cable?The maximum speed can be calculated according to the formula: ship’s speed minus water speed.4. What flag should be hoisted when a vessel requires a pilot?Flag "G”.5. How can a ship get in touch with a port before her arrival?The ship’s captain calls the pilot station through VHF communication / by VHF.6. What ship’s particulars will pilot station usually ask for?The ship’s name, length, breadth, gross tonnage, net tonnage, harbor spe ed, draft, revolutions, type of ship, propeller working condition, etc.7. What should be reported to the pilot station?The ship’s name, call sign, nationality, type of ship, number of persons on board, present position, ETA at pilot station, intended route, etc.8. What should be confirmed from the pilot station?The time when the pilot will be available, pilot’s boarding time and boarding point, the berthing time, etc.9. When the vessel enters the VTS area, what is requested to report?The ship’s name, call sign, flag state, ship’s position, course and speed, destination, last port of call, ETA and ETD, draft forward and aft, all equipment’s working condition, etc.10. What does “foul anchor” mean?It means the anchor has its own cable twisted around it.11. If you are ordered: “Stand by both engines!”, how should you reply and report?I will repeat the order:” Stand by both engines.”, and then report:” Both engines standby.”12. Can you list 3 famous canals in the world?The Panama Canal, the Suez Canal, and the Kiel Canal.13. When you request the receiver to remain on channel 16 in VHF communication,what do you say?“Stand by on VHF channel 16.”14. How to rectify the mistake in maritime VHF communication?I will first say: “Mistake…”followed by the word: “Correction” and t he correctmessage.15. How to give an emphasis on the important part of a message in maritime VHFcommunication?I will first say: “Repeat…” – followed by the important part of the message.16. What does “Abandon Vessel” mean?It means to evacuate crew and passengers from a vessel in emergency.17. What does the abbreviation ETD stand for?It stands for Estimated / Expected Time of Departure.18. What does “dredging of an anchor” mean?It means the anchor is moving along the sea bottom to control the movement of the vessel.19. What does “underway” mean?It means that a vessel is not at anchor, or made fast to the shore, or aground.20. What does “dragging of anchor” mean?It means the anchor is moving over the sea bottom involuntarily because it is no longer preventing the movement of the vessel.21. What is the difference between a “radar beacon” and a “radar reflector”?A radar beacon is a radar transponder emitting a characteristic signal; and a radarreflector is used to obtain stronger echoes from radar targets.22. How many objects do you need to get a position using “horizontal sextantangles”?At least 2 objects.23. Why is a magnetic compass kept on board when a gyro is more accurate?Because the magnetic compass is more reliable.24. What do you report when the anchor has been heaved out of the ground and isclear of it?I will report: “Anchor is aweigh.”25. When preparing for anchoring what must you do before releasing the bowstoppers?Before releasing the bow stoppers, we must make sure the windlass is out of gear and the brakes are on. Make sure the windlass is free to engage and the windlass is put into the gear.26. Would you let go an anchor from the hawse pipe if the depth was 75 metersNo, we would not.27. Why must you conside r ship’s speed and sea depth when you release the bowstoppers?When the ship’s speed is too fast, the anchor chain is easy to break, when too slowly the anchor can’t grab the ground. When the sea depth is too shallow, it’s easy to ground, and when too deep the anchor can’t reach the ground.28. What must always be brought and placed close to the pilot ladder well beforethe pilot’s embarkation?A heaving line and a life buoy.29. Why is dangerous to anchor in ice?Ice is an obstacle to any ship, so anchoring in ice will beset by the ice.30. What flag is hoisted when the pilot has arrived on board?Flag “H”.Chapter 4口述1. Describe the procedures of carrying dangerous cargo on board.a) The acquisition of information about the dangerous cargob) Precautions on loading and discharging.c) Maintenance during the voyage.Dangerous cargo is divided into nine classes according to IMDG. They are the explosives, gases, flammable liquids, flammable solids or substances, oxidizing substances and organic peroxides toxic and infectious substances, radioactive substances, corrosives and miscellaneous dangerous substances.Before loading and discharging dangerous cargo on board, we must know their names, types, and natures, check proper use of handling gear and segregation of goods, keep good ventilation, handle with care, stow flammable goods away from the engine room bulkhead,stow infectious substances separated by one compartment from foodstuffs.During the voyage, keep the gangway watch and deck watch, to keep an eye on the dangerous cargo.2. Describe the precautions before entering an enclosed space.a) The potential dangers in an enclosed space.b) The normal procedures.c) The important precautions.The enclosed space is liable to explode and self-ignite. Without the chief officer’s perdition, no one can enter the enclosed space.Before entering an enclosed space, we have to put on the protective clothing and breathing apparatus, safety belt, and carry walkie-talkies and air cylinder.The following precautions should be taken: check the ventilation and the state of the holds, open the ventilators to escape the exhausted air and get fresh air in; switch on automatic temperature control; test the air in the holds; open all entrances to the emergency lane, etc.3. Describe the procedures of cargo stowage.a) The acquisition of information about the cargo to be carried.b) The principles and considerations on the navigation safety.c) The modification of stowage plan.Before a ship loads her cargo, first of all, the chief officer must make out a cargo plan according to the details from the Loading List or Shipping Orders such as, cargo’s nature, packing, quantity and the measurement of each package.When arranging the locations of the different lots of cargo, the chief officer must consider the order of the discharging ports, the proper vessel’s trim, stability and stress. Then the original stowage plan can be modified during the cargo stowing.4. Describe the actions to be taken in case of an oil spill on board.a) The initial responses.b) The actions following up according to the SOPEP onboard.c) The precautions to be taken.First, stop the oil operation immediately and stand by spilling control gear. Then report and remove the spillage: separate the spilling oil; find the causes of spilling; take actions to absorb the spillage, such as spreading the absorbents.The precautions to be taken: stow the liquids properly in case of big wind and torrent; do the oil operations carefully; supply the oil-spillage gears; pilot the ship with caution; comply with the operating rules and so on.5. Describe how to ensure a proper stowage for general cargo.a) General factors to be taken into account in cargo stowage.b) Special considerations for cargo stowage.Before loading general cargo, the chief officer should make out the cargo plan according to the details from the loading list. When loading general cargo, the following factors should be considered: the nature of cargo, the kind of cargo, packing, quantity and size, themeasurement of each package, segregation and dunnage, ventilation and so on.Special considerations for cargo stowage are: the order of the loading and unloading, the vessel’s trim, stability and stress, the elimination of cargo da mage. Special attention should be paid to the dangerous cargo and deck cargo if there are any.问答1. How many classes of dangerous goods are there according to the IMDG Code? Canyou list some?9 classes. They are the explosive, gases, flammable liquid, flammable solids orsubstances, oxidizing substances and organic peroxides, toxic and infectious substances, radioactive substances, corrosives and miscellaneous dangerous substances.2. What kind of cargo is classified as flammable cargo?It refers to the goods which are liable to burn itself in normal temperature.3. Please describe the general nature of general cargo.It refers to the cargo with different characteristics and in different separation packages. It can be loaded by special crane or the ship’s own de rricks.4. Please describe the general nature of bulk cargo.Bulk cargo refers to the homogeneous cargo (同种类货物) not enclosed in a container. It is carried in bulk carriers.5. What kind of cargo is canvas sling suitable for lifting?It is used for lifting bags of grain, rice, coffee, etc.6. What kind of cargo is chain sling suitable for lifting?It is used for lifting logs, iron rails, etc.7. What kind of cargo is net sling suitable for lifting?It is used for lifting small packages and mail.8. What does the abbreviation COW stand for?It stands for Crude Oil Washing System.9. What does “jettison of cargo” mean?It means the action to deliberately throw cargo overboard.10. What does “compatibility of goods” mean?It means that different goods can be stowed together in the same hold.11. What does the abbreviation SWL stand for?Safe Working Load.12. What does “shifting cargo” mean?It means the cargo on board hasn’t been stowed and lashed securely and properly. They are easy to move in heavy seas during the voyage.13. What does “Union purchase” mean?It is a way or system used to load and discharge cargo with two derricks when working.14. What preparations shall be done before loading cargo?Preparing stowage plan, cleaning holds, preparing dunnages and loading & unloading appliances, checking ventilation system, etc.15. What is the loading capacity of your vessel?About 5,600 tons.16. What cargo handling gear and equipment does your vessel have?Derricks, cranes, winches, sling platform, chain sling, etc.17. What can be used to remove spillage?Use absorbents for the spillage.18. What shall be ensured before entering the enclosed space?The protective outfit.19. Please list some cargo papers.Stowage plan, loading list, cargo manifest, bill of lading, etc.20. What must you wear when you enter an enclosed space?Protective clothes and breathing apparatuses.Chapter 5口述1. Describe the duties of watch-keeping when underway.a) General rules as to watch-keeping.b) Items to be checked and monitored each watch.c) Special attention for bridge watch-keeping.General rules as to watch-keeping are: 1) Duty officers should hold the competent certificates;2) Route plan should be made in advance; 3) Master and officers should comply with the relevant rules and regulations, the world environment protection and the Convention of MARPOL.Every vessel shall at all times maintain a proper look-out. During each watch, check and monitor navigational aids, fathometer, gyrocompass, satellite navigator, VHF set, etc., check vessel’s speed and course, lighting, chro nometers and so on, receive and record broadcasts from weather forecast.Special attention should be paid to the management of the bridge, route planning, the training and maintaining of the safety system on board, main engines, operation of helicopter, deck-log writing and other monitoring systems.2.Describe the bridge shrift change.a) The conditions which must be satisfied before taking over a bridge watch.b) The procedures for shift changec) Special attention for shift changeBefore taking over the watch, first, the relieving officer should be familiar with the surroundings, be clear of vessel’s estimated position, course, speed and the potential hazards in the route. Then he must check the state of the navigational aids. He should also know the weather condition and drafts.Before shift change, the duty sailor should inform the relieving officer 30 minutes in advance. The relieving officer should be on the bridge 15 minutes before taking over the watch. Both the relieving officer and the duty officer should sign in the logbook.We can’t hand over the watch when the vessel is altering the course or under the situation of。

海运术语解释

简称中文解释英文全称A/W 全水路 All WaterANER 亚洲北美东行运费协定 Asia NorthAmerica EastboundRate B/L 海运提单 Bill of LadingB/R 买价 Buying RateBAF 燃油附加费 Bunker AdjustmentFactorC&F 成本加海运费 COST AND FREIGHTC.C 运费到付 CollectC.S.C 货柜服务费 Container Service ChargeC.Y. 货柜场 Container YardC/(CNEE) 收货人 ConsigneeC/O 产地证 Certificate of OriginCAF 货币汇率附加费 Currency Adjustment FactorCFS 散货仓库 Container Freight StationCFS/CFS 散装交货〔起点/终点〕CHB 报关行 Customs House BrokerCIF 成本，保险加海运费 COST，INSURANCE，FRIGHTCIP 运费、保险费付至目的地 Carriage and Insurance Paid To COMM 商品 CommodityCPT 运费付至目的地 Carriage Paid ToCTNR 柜子 ContainerCY/CY 整柜交货〔起点/终点〕D/A 承兑交单 Document Against AcceptanceD/O 到港通知 Delivery OrderD/P 付款交单 Document Against PaymentDAF 边境交货 Delivered At FrontierDDC 目的港码头费 Destination Delivery Charge DDP 完税后交货 Delivered Duty PaidDDU 未完税交货 Delivered Duty UnpaidDEQ 目的港码头交货 Delivered Ex QuayDES 目的港船上交货 Delivered Ex ShipDoc# 文件 Document NumberEPS 设备位置附加费 Equipment Position Surcharges Ex 工厂交货 Work/ExFactoryF/F 货运代理 Freight ForwarderFAF 燃料附加费 Fuel AdjustmentFactorFAK 各种货品 Freight All KindFAS 装运港船边交货 Free Alongside ShipFCA 货交承运人 Free CarrierFCL 整柜 Full Container LoadFeeder Vessel/Lighter 驳船航次FEU 40‘柜型 Forty-Foot Equivalent Unit 40’FMC 联邦海事委员会 Federal Maritime Commission FOB 船上交货 Free On BoardGRI 全面涨价 General RateIncreaseH/C 代理费 Handling ChargeHBL 子提单 House B/LI/S 内销售 Inside SalesIA 各别调价 Independent ActionL/C 信用证 Letter of CreditLand Bridge 陆桥LCL 拼柜 Less Than Container LoadM/T 尺码吨〔即货物收费以尺码计费〕 Measurement Ton MB/L 主提单 Master Bill Of LoadingMLB 小陆桥，自一港到另一港口 Minni Land Bridge Mother Vessel 主线船MTD 多式联运单据 Multimodal Transport DocumentN/F 通知人 NotifyNVOCC 无船承运人 Non Vessel OperatingCommon CarrierO/F 海运费 Ocean FreightOBL 海运提单 Ocean (or original )B/LOCP 货主自行安排运到内陆点 Overland Continental Point OP 操作 OperationORC 本地收货费用〔XX省收取〕 Origen Recevie Charges P.P 预付 PrepaidPCS 港口拥挤附加费 Port Congestion SurchargePOD 目地港 Port Of DestinationPOL 装运港 Port Of LoadingPSS 旺季附加费 Peak Season SuchargesS/(Shpr) 发货人 ShipperS/C 售货合同 Sales ContractS/O 装货指示书 Shipping OrderS/R 卖价 Selling RateS/S Spread Sheet Spread SheetSC 服务合同 Service ContractSSL 船公司 Steam Ship LineT.O.C 码头操作费 Terminal Operations OptionT.R.C 码头收柜费 Terminal Receiving ChargeT/S 转船，转运 Trans-ShipT/T 航程 Transit TimeTEU 20‘柜型 Twenty-Foot Equivalent Unit 20’THC 码头操作费〔XX收取) Terminal Handling ChargesTTL 总共 TotalTVC/ TVR 定期定量合同 Time Volume Contract/ RateVOCC 船公司 Vessel Operating Common CarrierW/M 即以重量吨或者尺码吨中从高收费 Weight or Measurement tonW/T 重量吨(即货物收费以重量计费) Weight TonYAS 码头附加费 Yard SurchargesUSWC: UNITED STATE WEST COAST 美国太平洋西岸之港口USEC: UNITED STATE EAST COAST 美国太平洋东岸之港口VSL/VOY: VESSEL/VOYAGE船名航次AMS:Automated Manifest System 美国自动仓单系统ACI:ADVANCE COMMERCIAL INFORMATION =AMSDEMURRANGE/STORAGE：仓租DETENTION：柜租D/O：DELIVERY ORDER 到货通知FORM A：普惠制产地证某些国家给予我国一些优惠政策作为进口海关减免关税的依据，如：英、美、德、瑞士、瑞典、芬兰等1．干货集装箱〔DRY CARGO CONTAINER〕2．散货集装箱〔BULK CONTAINER〕如：装谷物，树脂等3．冷藏集装箱〔REEFER CONTAINER，RF〕4．敞顶集装箱〔OPEN-TOP CONTAINER，OT〕即开顶柜5．框架集装箱〔PLAT FORM BASED CONTAINER〕6．牲畜集装箱〔PEN CONTAINER〕7．罐式集装箱〔TANK CONTAINER，TK〕8．汽车集装箱〔CAR CONTAINER〕CLG: Closing Date 截关日ETD：Estimated time of departure 预计离港日ETA:：Estimated time of arrival 预计到港日主要贸易术语：(1)FCA (Free Carrier) 货交承运人(2)FAS (Free Alongside Ship) 装运港船边交货(3)FOB (Free on Board) 装运港船上交货 (4)CFR (Cost and Freight) 成本加运费 (5)CIF (Cost,Insurance and Freight) 成本、保险费加运费(6)CPT (Carriage Paid To) 运费付至目的地(7)CIP (Carriage and Insurance Paid To) 运费、保险费付至目的地(8)DAF (Delivered At Frontier) 边境交货(9)DES (Delivered Ex Ship) 目的港船上交货(10)DEQ (Delivered Ex Quay) 目的港码头交货(11)DDU (Delivered Duty Unpaid) 未完税交货 (12)DDP (Delivered Duty Paid) 完税后交货主要船务术语简写：(1)ORC (Origen Recevie Charges) 本地收货费用〔XX省收取〕(2)THC (Terminal Handling Charges) 码头操作费〔XX收取〕(3)BAF (Bunker Adjustment Factor) 燃油附加费(4)CAF (Currency Adjustment Factor) 货币贬值附加费(5)YAS (Yard Surcharges)码头附加费(6)EPS (Equipment Position Surcharges) 设备位置附加费(7)DDC (Destination Delivery Charges) 目的港交货费(8)PSS (Peak Season Sucharges) 旺季附加费(9)PCS (Port Congestion Surcharge) 港口拥挤附加费(10)DOC (DOcument charges) 文件费(11)O/F (Ocean Freight) 海运费(12)B/L (Bill of Lading) 海运提单(13)MB/L(Master Bill of Lading) 船东单〔或OCEAN BILL OF LADING〕(14)MTD (Multimodal Transport Document) 多式联运单据(15)L/C (Letter of Credit) 信用证(16)C/O (Certificate of Origin) 产地证(17)S/C (Sales Confirmation)销售确认书〔Sales Contract) 销售合同(18)S/O (Shipping Order)装货指示书(19)W/T (Weight Ton)重量吨〔即货物收费以重量计费〕(20)M/T (Measurement Ton)尺码吨〔即货物收费以尺码计费〕(21)W/M(Weight or Measurement ton)即以重量吨或者尺码吨中从高收费(22)CY (Container Yard) 集装箱〔货柜〕堆场(23)FCL (Full Container Load) 整箱货(24)LCL (Less than Container Load) 拼箱货〔散货〕(25)CFS (Container Freight Station) 集装箱货运站(26)TEU (Twenty-feet Equivalent Units) 20英尺换算单位〔用来计算货柜量的多少〕(27)A/W (All Water)全水路〔主要指由美国西岸中转至东岸或内陆点的货物的运输方式〕(28)MLB(Mini Land Bridge)小陆桥〔主要指由美国西岸中转至东岸或内陆点的货物的运输方式〕(29)NVOCC(Non-Vessel Operating Common Carrier) 无船承运人AMS American/Automatic ManifestSystem 美国〔自动〕舱单录入费BAF Bunker Adjustment Factor 燃油附加费Container Service Charge 货柜服务费CAF Currency Adjustment Factor 货币贬值附加费系数CAS Currency Adjustment Surcharge 货币贬值附加费DDC Destination Delivery Charge 目的港码头费Deviation Surcharge 绕航附加费Direct Additional 直航附加费EBA Emergency Bunker Additional 紧急燃油附加费〔非、中南美〕EBS Emergency Bunker Surcharge 紧急燃油附加费〔澳新〕EPS Equipment Position Surcharges 设备位置附加费FAF Fuel Adjustment Factor 燃料附加费〔日〕GRI General Rate Increase 综合费率上涨附加费Heavy-lift Additional 超重附加费IFA Interim Fuel Additional 临时燃油附加费Long Length Additional 超长附加费ORC Original Receiving Charge 本地收货费用PCS Panama Canal Surcharge 巴拿马运河附加费PCTF Panama Canal Transit Fee 巴拿马运河附加费PTF Panama Transit Fee 巴拿马运河附加费PSS Peak Season Surcharges 旺季附加费PCS Port Congestion Surcharge 港口拥挤附加费SPS ShanghaiPort Surcharge XX码头费SCS Suez Canal Surcharge 苏伊士运河附加费TAR Temporary Additional Risks 临时风险附加费THC Terminal Handling Charges 码头操作费Terminal Operations Charge 码头操作费Terminal Receiving Charge 码头收柜费Transhipment Surcharge 转船附加费WRS War Risk Surcharge 战争险附加费YAS Yard Surcharges 码头附加费YAS Yen Adjustment Surcharge 日元贬值费各航线运费组成欧洲线：O/F+ORC+BAF+CAF+DOC北美线：O/F+ORC+AMS+DOC〔+DDC+BAF〕中南美线：O/F+ORC〔THC〕+DOC东南亚线：O/F+THC+DOC〔+T/R〕印巴线：O/F+THC+DOC澳洲线：O/F+THC+DOC红海线：O/F+THC+DOC非洲线：O/F+THC+DOC注：O/F〔OCEAN FREIGHT 海运费用〕ORC〔本地出口附加费〕USD141/20’USD269/40’&40’HQTHC〔码头费用〕RMB370/20’RMB5608/40’＆40’HQDOC〔文件费用〕USD15/SETT/R 〔电放费用〕USD15/SETAMS〔出口北美货物预申报费用〕USD25/SETBAF〔燃油附加费〕收费视情况而不同CAF〔货币贬值附加费〕收费视情况而不同保险单：Insurance Policy,又称为大保单，是一种正规的保险合同。

口语答案---最新整理

口语答案---最新整理航海英语会话答案Chapter 1问答：1.What is your date of birth?-----May first, 1983.你的出生日期是什么？1983年五月一日2.What is your seaman?s book number?----L236625你的海员证编码是什么？L/A+6位数字（随意答）3.Where are you from?---- Shandong China.你来自哪里？我来自山东/中国4.What?s your captain?s nationality(国籍)?----China.你们船长的国籍是什么？中国5.What do you think is the most important thing on board?----Safety.你认为在船上什么是最重要的事情？安全6.Which ports do you often call at? ----Qingdao por t.你经常挂靠的港口是哪里？青岛港7. What is your favorite TV program? ----CCTV5 about football program.你最喜欢的电视节目是什么？中央5体育节目8. What is your favorite Web site? ----- Sina你最喜欢的网站是什么？新浪9. What is your favorite day of the week? Why? -----Sunday. Because I can have a rest.你最喜欢一周之中的哪一天？为什么？星期天，因为我能休息10. What is your favorite kind of movie? ----Action movies.你最喜欢哪种类型的电影？动作片11. What is your favorite kind of music? ---- Pop music.你最喜欢什么类型的音乐流行音乐12. What is your favorite magazine? ----Youth/English salon.你最喜欢哪个杂志？英语沙龙13. What is the population of your hometown? ----1 million你家乡的人口是多少？1百万14. What is the population of your country? ---- more than 1.3 billion.你国家的人口是多少？超过13亿15. What is the best thing about your hometown? -- The air is fresh and people there are friendly.关于你的家乡最好的事情是什么？空气清新或是人友好（二选一答即可）16.What is the worst thing about your hometown? ----The street is dirty./ the wind is very strong.关于你的家乡最不好的事情是什么？街道脏17. What?s your hometown like?----Beautiful.你的家乡怎么样？美丽18. Do you have many disasters in your country which are caused by weather?----Yes. We have, such as flooding.在你的国家有没有由于天气原因引起的灾难？有，例如：洪水19. What sports do you like to watch on TV? ----Football.你喜欢看电视上哪种体育运动？足球20. What do you think the most popular sport in the world? ----Football.你认为世界上最流行的体育项目是什么？足球口述：1. Please say sth about your hometown.请说出你的家乡...... 。

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a r X i v :c s /0411028v 1 [c s .D C ] 10 N o v 2004A Machine-Independent Port of the SR Language Run Time System to NetBSD Operating SystemIgnatios SouvatzisUniversity of Bonn,CS Dept.,Chair V<ignatios@cs.uni-bonn.de>29th of September,20041IntroductionSR (synchronizing resources)[1]is a PASCAL –style language enhanced with constructs for concurrent programming developed at the University of Arizona in the late 1980s[2].MPD (presented in Gregory Andrews’book about Foundations of Multithreaded,Par-allel,and Distributed Programming[3])is its successor,providing the same language primitives with a diﬀerent syntax.The run-time system (in theory,identical)of both languages provides the illusion of a multiprocessor machine on a single single-or multi-CPU Unix-like system or a (local area)network of Unix-like machines.Chair V of the Computer Science Department of the University of Bonn is operating a laboratory for a practical course in parallel programming consisting of computing nodes running NetBSD/arm,normally used via PVM,MPI etc.We are considering to oﬀer SR and MPD for this,too.As the original language distributions are only targeted at a few commercial Unix systems,some porting eﬀort is needed,outlined in the SR porting guide[4].The integrated POSIX threads support of NetBSD-2.0should allow us to use li-brary primitives provided for NetBSD’s phtread system to implement the primitives needed by the SR run-time system,thus implementing 13target CPUs at once and automatically making use of SMP on VAX,Alpha,PowerPC,Sparc,32-bit Intel and 64bit AMD CPUs.This paper describes work in progress.2Generic Porting ProblemsGiven the age of the software and the gradual development of the C language and the operating system environments available,some adaptation is to be expected.Fortu-nately,the latest distribution of SR (version 2.3.2)has already been portend to two relatively modern Unix-like environments (Solaris 2.2and Linux),so the necessary changes turned out to be conﬁned to a one area:gcc 3,the system compiler of NetBSD-2.0,doesn’t provide old <varags.h>variable argument functions anymore,so those had to be converted to <stdarg.h>syntax.Also,none of those functions had ﬁxed arguments.Most of the functions had a ﬁrst logical parameter char *locn which could be changed into a ﬁxed parameter.A few functions had a ﬁrst integer parameter (a count of the remaining parameters).In oneImplementationi386assembler6.025µsTable1:Raw context switch times case(srTest description SVR4s.c.0.01µs0.07µs1.45µs2.95µs2.46µssemaphore P only0.07µssemaphore V only0.05µssemaphore pair0.11µssemaphore requiring context switch9.09µs1.71µs1.90µsrendezvous27.05µsTable2:Run time system performance.The median times reported by the SR script vsuite/timings/report.sh are reported.Theﬁrst tests were done by using the provided i386assembler context switch rou-tines.After verifying correctness and noting the times(see tables5and5),the same was done using the SVR4module instead of the assembler module.All tests were done on a500MHz Pentium III machine with16+16kB of primary cache and512kB of secondary cache,and128MB of main memory,running NetBSD-2.0getcontext setcontextsetcontext getcontextsetcontext getcontextsetcontext getcontextbe analyzed further.7Work items left to do7.1Building a package for pkgsrcTo ease installation,a prototype package for the NetBSD package system has been built.It needs a bit of reﬁnement,though,but will be available soon.(As the NetBSD package system is available for more operating systems than NetBSD,a bit more work is needed.)7.2Implementing and testing multithreaded SRSR can be compiled in a mode where it will make use of multiple threads provided by the underlying OS,so that it can use more than one CPU of a single machine.This has not been implemented yet for NetBSD,but should be.References[1]Gregory R.Andrews and Ronald A.Olsson,The SR Programming Language:Concurrency in Practice(Benjamin/Cummings,1993[2]Gregory R.Andrews,Ronald A.Olsson,Michael H.Coﬃn,Irving Elshoﬀ,KelvinD.Nilsen,Titus Purdin and Gregg M.Townsend,An Overview of the SR Languageand Implementation,1988,ACM TOPLAS Vol.10.1,p.51-86[3]Gregory R.Andrews,Foundations of Multithreaded,Parallel,and Distributed Pro-gramming,Addison-Wesley,2000(ISBN0-201-35752-6)[4]Gregg Townsend,Dave Bakken,Porting the SR Programming Language,1994,Department of Computer Science,The University of Arizona[5]Nathan J.Williams,An Implementation of Scheduler Activations onthe NetBSD Operating System,in:Proceedings of the FREENIX Track,2002Usenix Annual Technical Conference,Monterey,CA,USA, /events/usenix02/tech/freenix/williams.html。