Introduction to General Relativity
Relativity -- The Special and General Theory
28. Exact Formulation of the General Principle of Relativity...............................................30
29. The Solution of the Problem of Gravitation on the Basis of the General Principle of
Relativity ........................................................................................................... 31
Part III Considerations on the Universe as a Whole
15. General Results of the Theory.........................................................................................14
16. Experience and the Special Theory of Relativity............................................................15
13. Theorem of the Addition of Velocities. The Experiment of Fizeau.................................12
14. The Heuristic Value of the Theory of Relativity .............................................................13
Lecture Notes on General Relativity
The primary question facing any introductory treatment of general relativity is the level of mathematical rigor at which to operate. There is no uniquely proper solution, as di erent students will respond with di erent levels of understanding and enthusiasm to di erent approaches. Recognizing this, I have tried to provide something for everyone. The lectures do not shy away from detailed formalism (as for example in the introduction to manifolds), but also attempt to include concrete examples and informal discussion of the concepts under consideration.
4. Gravitation the Principle of Equivalence | gravitational redshift | gravitation as spacetime curvature | the Newtonian limit | physics in curved spacetime | Einstein's equations | the Hilbert action | the energy-momentum tensor again | the Weak Energy Condition | alternative theories | the initial value problem | gauge invariance and harmonic gauge | domains of dependence | causality
general theory of relativity
XVIII. Special and General Principle of Relativity1 THE BASAL principle, which was the pivot of all our previous considerations, was the special principle of relativity, i.e. the principle of the physical relativity of all uniform motion. Let us once more analyse its meaning carefully.It was at all times clear that, from the point of view of the idea it2 conveys to us, every motion must only be considered as a relative motion. Returning to the illustration we have frequently used of the embankment and the railway carriage, we can express the fact of the motion here taking place in the following two forms, both of which are equally justifiable:a.The carriage is in motion relative to the embankment.b.The embankment is in motion relative to the carriage.3 In (a) the embankment, in (b) the carriage, serves as the body of reference in our statement of the motion taking place. If it is simply a question of detecting or of describing the motion involved, it is in principle immaterial to what reference-body we refer the motion. As already mentioned, this is self-evident, but it must not be confused with the much more comprehensive statement called “the principleof relativ ity,” which we have taken as the basis of our investigations.The principle we have made use of not only maintains that we may4 equally well choose the carriage or the embankment as our reference-body for the description of any event (for this, too, is self-evident). Our principle rather asserts what follows: If we formulate the general laws of nature as they are obtained from experience, by making use ofa.the embankment as reference-body,b.the railway carriage as reference-body,then these general laws of nature (e.g. the laws of mechanics or the law of the propagation of light in vacuo) have exactly the same formin both cases. This can also be expressed as follows: For the physical description of natural processes, neither of the reference-bodies K,K'is unique (lit. “specially marked out”) as compared with the other. Unlike the first, this latter statement need not of necessity hold a priori;it is not contained in the conceptions of “motion” and “referencebody” and derivable from them; only experience can decide as to its correctness or incorrectness.5 Up to the present, however, we have by no means maintained the equivalence of all bodies of reference K in connection with the formulation of natural laws. Our course was more on the following lines. In the first place, we started out from the assumption thatthere exists a reference-body K, whose condition of motion is such that the Galileian law holds with respect to it: A particle left to itself and sufficiently far removed from all other particles moves uniformlyin a straight line. With reference to K (Galileian reference-body) the laws of nature were to be as simple as possible. But in addition to K,all bodies of reference K'should be given preference in this sense, and they should be exactly equivalent to K for the formulation of natural laws, provided that they are in a state of uniform rectilinear and non-rotary motion with respect to K;all these bodies of reference are to be regarded as Galileian reference-bodies. The validity of the principle of relativity was assumed only for these reference-bodies, but not for others (e.g. those possessing motion ofa different kind). In this sense we speak of the special principle of relativity, or special theory of relativity.In contra st to this we wish to understand by the “general principle of6 relativity” the following statement: All bodies of reference K, K', etc., are equivalent for the description of natural phenomena (formulationof the general laws of nature), whatever may be their state of motion. But before proceeding farther, it ought to be pointed out that this formulation must be replaced later by a more abstract one, for reasons which will become evident at a later stage.Since the introduction of the special principle of relativity has been 7justified, every intellect which strives after generalisation must feel the temptation to venture the step towards the general principle of relativity. But a simple and apparently quite reliable consideration seems to suggest that, for the present at any rate, there is little hope of success in such an attempt. Let us imagine ourselves transferred to our old friend the railway carriage, which is travelling at a uniform rate. As long as it is moving uniformly, the occupant of the carriage is not sensible of its motion, and it is for this reason that he can un-reluctantly interpret the facts of the case as indicating that the carriage is at rest, but the embankment in motion. Moreover, according to the special principle of relativity, this interpretation is quite justified also from a physical point of view.If the motion of the carriage is now changed into a non-uniform motion, as for instance by a powerful application of the brakes, then the occupant of the carriage experiences a correspondingly powerful jerk forwards. The retarded motion is manifested in the mechanical behaviour of bodies relative to the person in the railway carriage. The mechanical behaviour is different from that of the case previously considered, and for this reason it would appear to be impossible that the same mechanical laws hold relatively to the non-uniformly moving carriage, as hold with reference to the carriage when at rest or in uniform motion. At all events it is clear that the Galileian lawdoes not hold with respect to the non-uniformly moving carriage. Because of this, we feel compelled at the present juncture to grant a kind of absolute physical reality to non-uniform motion, in opposition to the general principle of relativity. But in what follows we shall soon see that this conclusion cannot be maintained.XIX. The Gravitational Field“IF we pick up a stone and then let it go, why does it fall to the1 ground?” The usual answer to this question is: “Because it is attracted by the earth.” Modern physics formulates the answer rather differently for the following reason. As a result of the more careful study of electromagnetic phenomena, we have come to regard action at a distance as a process impossible without the intervention of some intermediary medium. If, for instance, a magnet attracts a pieceof iron, we cannot be content to regard this as meaning that the magnet acts directly on the iron through the intermediate empty space, but we are constrained to imagine—after the manner of Faraday—that the magnet always calls into being something physically real in the space around it, that something being what we call a “magnetic field.” In its turn this magnetic field operates on thepiece of iron, so that the latter strives to move towards the magnet. We shall not discuss here the justification for this incidental conception, which is indeed a somewhat arbitrary one. We shall only mention that with its aid electromagnetic phenomena can be theoretically represented much more satisfactorily than without it, and this applies particularly to the transmission of electromagnetic waves. The effects of gravitation also are regarded in an analogous manner.2 The action of the earth on the stone takes place indirectly. The earth produces in its surroundings a gravitational field, which acts on the stone and produces its motion of fall. As we know from experience, the intensity of the action on a body diminishes according to a quite definite law, as we proceed farther and farther away from the earth. From our point of view this means: The law governing the propertiesof the gravitational field in space must be a perfectly definite one, in order correctly to represent the diminution of gravitational action with the distance from operative bodies. It is something like this: The body (e.g.the earth) produces a field in its immediate neighbourhood directly; the intensity and direction of the field at points farther removed from the body are thence determined by the law which governs the properties in space of the gravitational fields themselves.In contrast to electric and magnetic fields, the gravitational field3 exhibits a most remarkable property, which is of fundamental importance for what follows. Bodies which are moving under the sole influence of a gravitational field receive an acceleration, which does not in the least depend either on the material or on the physical state of the body. For instance, a piece of lead and a piece of wood fall in exactly the same manner in a gravitational field (in vacuo), when they start off from rest or with the same initial velocity. This law, which holds most accurately, can be expressed in a different form in the light of the following consideration.4 According to Newton’s law of motion, we have(Force) = (inertial mass) × (acceleration),where the “inertial mass” is a characteristic constant of the accelerated body. If now gravitation is the cause of the acceleration, we then have(Force) = (gravitational mass) × (intensity of thegravitational field),where the “gravitational mass” is l ikewise a characteristic constant for the body. From these two relations follows:If now, as we find from experience, the acceleration is to be5 independent of the nature and the condition of the body and always the same for a given gravitational field, then the ratio of the gravitational to the inertial mass must likewise be the same for all bodies. By a suitable choice of units we can thus make this ratio equalto unity. We then have the following law: The gravitational mass of a body is equal to its inertial mass.6 It is true that this important law had hitherto been recorded in mechanics, but it had not been interpreted. A satisfactory interpretation can be obtained only if we recognise the following fact: The same quality of a body manifests itself according to circumstances as “inertia” or as “weight” (lit. “heaviness”). In the following section we shall show to what extent this is actually the case, and how this question is connected with the general postulateof relativity.XX. The Equality of Inertial and Gravitational Mass as an Argument for the General Postulate of RelativityWE imagine a large portion of empty space, so far removed from1 stars and other appreciable masses that we have before us approximately the conditions required by the fundamental law of Galilei. It is then possible to choose a Galileian reference-body for this part of space (world), relative to which points at rest remain at rest and points in motion continue permanently in uniform rectilinear motion. As reference-body let us imagine a spacious chest resemblinga room with an observer inside who is equipped with apparatus. Gravitation naturally does not exist for this observer. He must fasten himself with strings to the floor, otherwise the slightest impact against the floor will cause him to rise slowly towards the ceiling of the room.2 To the middle of the lid of the chest is fixed externally a hook with rope attached, and now a “being” (what kind of a being is immaterialto us) begins pulling at this with a constant force. The chest together with the observer then begin to move “upwards” with a uniformly accelerated motion. In course of time their velocity will reach unheard-of values—provided that we are viewing all this from another reference-body which is not being pulled with a rope.But how does the man in the chest regard the process? The3 acceleration of the chest will be transmitted to him by the reaction of the floor of the chest. He must therefore take up this pressure bymeans of his legs if he does not wish to be laid out full length on the floor. He is then standing in the chest in exactly the same way as anyone stands in a room of a house on our earth. If he release a body which he previously had in his hand, the acceleration of the chest will no longer be transmitted to this body, and for this reason the body will approach the floor of the chest with an accelerated relative motion. The observer will further convince himself that the acceleration of the body towards the floor of the chest is always of the same magnitude, whatever kind of body he may happen to use for the experiment.4 Relying on his knowledge of the gravitational field (as it was discussed in the preceding section), the man in the chest will thus come to the conclusion that he and the chest are in a gravitational field which is constant with regard to time. Of course he will be puzzled for a moment as to why the chest does not fall in this gravitational field. Just then, however, he discovers the hook in the middle of the lid of the chest and the rope which is attached to it, and he consequently comes to the conclusion that the chest is suspended at rest in the gravitational field.Ought we to smile at the man and say that he errs in his conclusion?5 I do not believe we ought if we wish to remain consistent; we must rather admit that his mode of grasping the situation violates neitherreason nor known mechanical laws. Even though it is being accelerated with respect to the “Galileian space” first co nsidered, we can nevertheless regard the chest as being at rest. We have thus good grounds for extending the principle of relativity to include bodies of reference which are accelerated with respect to each other, and as a result we have gained a powerful argument for a generalised postulate of relativity.We must note carefully that the possibility of this mode of6 interpretation rests on the fundamental property of the gravitational field of giving all bodies the same acceleration, or, what comes to the same thing, on the law of the equality of inertial and gravitational mass. If this natural law did not exist, the man in the accelerated chest would not be able to interpret the behaviour of the bodies around him on the supposition of a gravitational field, and he would not be justified on the grounds of experience in supposing his reference-body to be “at rest.”7 Suppose that the man in the chest fixes a rope to the inner side of the lid, and that he attaches a body to the free end of the rope. The result of this will be to stretch the rope so that it will hang “vertically” downwards. If we ask for an opinion of the cause of tension in the rope, the man in the chest will say: “The suspended body experiences a downward force in the gravitational field, and this isneutralised by the tension of the rope; what determines the magnitude of the tension of the rope is the gravitational mass of the suspended body.” On the other hand, an observer who is poised freely in space will interpret the condition of things thus: “The rope must perforce take part in the accelerated motion of the chest, and it transmits this motion to the body attached to it. The tension of the rope is just large enough to effect the acceleration of the body. That which determines the magnitude of the tension of the rope is the inertial mass of the body.” Guided by this example, we see that our extension of the principle of relativity implies the necessity of the law of the equality of inertial and gravitational mass. Thus we have obtained a physical interpretation of this law.From our consideration of the accelerated chest we see that a8 general theory of relativity must yield important results on the lawsof gravitation. In point of fact, the systematic pursuit of the general idea of relativity has supplied the laws satisfied by the gravitational field. Before proceeding farther, however, I must warn the reader against a misconception suggested by these considerations. A gravitational field exists for the man in the chest, despite the fact that there was no such field for the co-ordinate system first chosen. Now we might easily suppose that the existence of a gravitational field is always only an apparent one. We might also think that, regardless ofthe kind of gravitational field which may be present, we could always choose another reference-body such that no gravitational field exists with reference to it. This is by no means true for all gravitational fields, but only for those of quite special form. It is, for instance, impossible to choose a body of reference such that, as judged from it, the gravitational field of the earth (in its entirety) vanishes.9 We can now appreciate why that argument is not convincing, which we brought forward against the general principle of relativity at the end of Section XVIII. It is certainly true that the observer in the railway carriage experiences a jerk forwards as a result of the application of the brake, and that he recognises in this the non-uniformity of motion (retardation) of the carriage. But he is compelled by nobody to refer this jerk to a “real” acceleration (retardation) of the carriage. He might also interpret his experience thus: “My body of reference (the carriage) remains permanently at rest. With reference to it, however, there exists (during the period of application of the brakes) a gravitational field which is directed forwards and which is variable with respect to time. Under the influence of this field, the embankment together with the earth moves non-uniformly in such a manner that their original velocity in the backwards direction is continuously reduced.”XXI. In What Respects Are the Foundations of Classical Mechanics and of the Special Theory of Relativity Unsatisfactory?1 WE have already stated several times that classical mechanics starts out from the following law: Material particles sufficiently far removed from other material particles continue to move uniformly in a straight line or continue in a state of rest. We have also repeatedly emphasised that this fundamental law can only be valid for bodies of reference K which possess certain unique states of motion, and which are in uniform translational motion relative to each other. Relative to other reference-bodies K the law is not valid. Both in classical mechanics and in the special theory of relativity we therefore differentiate between reference-bodies K relative to which the recognised “laws of nature” can be said to hold, and reference-bodiesK relative to which these laws do not hold.2 But no person whose mode of thought is logical can rest satisfied with this condition of things. He asks: “How does it come that certain reference-bodies (or their states of motion) are given priority over other reference-bodies (or their states of motion)? What is thereason for this preference? In order to show clearly what I mean by this question, I shall make use of a comparison.3 I am standing in front of a gas range. Standing alongside of each other on the range are two pans so much alike that one may be mistaken for the other. Both are half full of water. I notice that steamis being emitted continuously from the one pan, but not from the other. I am surprised at this, even if I have never seen either a gas range or a pan before. But if I now notice a luminous something of bluish colour under the first pan but not under the other, I cease to be astonished, even if I have never before seen a gas flame. For I can only say that this bluish something will cause the emission of the steam, or at least possibly it may do so. If, however, I notice the bluish something in neither case, and if I observe that the one continuously emits steam whilst the other does not, then I shall remain astonished and dissatisfied until I have discovered some circumstance to which I can attribute the different behaviour of the two pans.4 Analogously, I seek in vain for a real something in classical mechanics (or in the special theory of relativity) to which I can attribute the different behaviour of bodies considered with respect to the reference-systems K and K'.1Newton saw this objection and attempted to invalidate it, but without success. But E. Mach recognised it most clearly of all, and because of this objection heclaimed that mechanics must be placed on a new basis. It can only be got rid of by means of a physics which is conformable to the general principle of relativity, since the equations of such a theory hold for every body of reference, whatever may be its state of motion.Note 1. The objection is of importance more especially when the state of motion of the reference-body is of such a nature that it does not require any external agency for its maintenance, e.g. in the case when the reference-body is rotating uniformly.XXII. A Few Inferences from the General Theory of RelativityTHE CONSIDERATIONS of Section XX show that the general theory of1 relativity puts us in a position to derive properties of the gravitational field in a purely theoretical manner. Let us suppose, for instance, that we know the space-time “course” for any natural process whatsoever, as regards the manner in which it takes place in the Galileian domain relative to a Galileian body of reference K. Bymeans of purely theoretical operations (i.e. simply by calculation) we are then able to find how this known natural process appears, as seen from a reference-body K' which is accelerated relatively to K. But since a gravitational field exists with respect to this new body of reference K', our consideration also teaches us how the gravitational field influences the process studied.2 For example, we learn that a body which is in a state of uniform rectilinear motion with respect to K (in accordance with the law of Galilei) is executing an accelerated and in general curvilinear motion with respect to the accelerated reference-body K'(chest). This acceleration or curvature corresponds to the influence on the moving body of the gravitational field prevailing relatively to K'. It is known that a gravitational field influences the movement of bodiesin this way, so that our consideration supplies us with nothing essentially new.3 However, we obtain a new result of fundamental importance when we carry out the analogous consideration for a ray of light. With respect to the Galileian reference-body K,such a ray of light is transmitted rectilinearly with the velocity c. It can easily be shown that the path of the same ray of light is no longer a straight line when we consider it with reference to the accelerated chest(reference-body K'). From this we conclude, that, in general, rays of light are propagated curvilinearly in gravitational fields.In two respects this result is of great importance.In the first place, it can be compared with the reality. Although a4 detailed examination of the question shows that the curvature of light rays required by the general theory of relativity is only exceedingly small for the gravitational fields at our disposal in practice, its estimated magnitude for light rays passing the sun at grazing incidence is nevertheless 1.7 seconds of arc. This ought to manifest itself in the following way. As seen from the earth, certain fixed stars appear to be in the neighbourhood of the sun, and are thus capable of observation during a total eclipse of the sun. At such times, these stars ought to appear to be displaced outwards from the sun by an amount indicated above, as compared with their apparent position in the sky when the sun is situated at another partof the heavens. The examination of the correctness or otherwise of this deduction is a problem of the greatest importance, the early solution of which is to be expected of astronomers. 1In the second place our result shows that, according to the general5 theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptionsin the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvatureof rays of light can only take place when the velocity of propagationof light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality thisis not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its result hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light).6 Since it has often been contended by opponents of the theory of relativity that the special theory of relativity is overthrown by the general theory of relativity is overthrown by the general theory of relativity, it is perhaps advisable to make the facts of the case clearer by means of an appropriate comparison. Before the development of electrodynamics the laws of electrostatics and the laws of electricity were regarded indiscriminately. At the present time we know that electric fields can be derived correctly from electrostatic considerations only for the case, which is never strictly realised, in which the electrical masses are quite at rest relatively to each other, and to the co-ordinate system. Should we be justified in saying that for this reason electrostatics is overthrown by the field-equations ofMaxwell in electrodynamics? Not in the least. Electrostatics is contained in electrodynamics as a limiting case; the laws of the latter lead directly to those of the former for the case in which the fields are invariable with regard to time. No fairer destiny could be allottedto any physical theory, than that it should of itself point out the wayto the introduction of a more comprehensive theory, in which it lives on as a limiting case.In the example of the transmission of light just dealt with, we have7 seen that the general theory of relativity enables us to derive theoretically the influence of a gravitational field on the course of natural processes, the laws of which are already known when a gravitational field is absent. But the most attractive problem, to the solution of which the general theory of relativity supplies the key, concerns the investigation of the laws satisfied by the gravitational field itself. Let us consider this for a moment.8 We are acquainted with space-time domains which behave (approximately) in a “Galileian” fashion under suitable choice of reference-body, i.e. domains in which gravitational fields are absent.If we now refer such a domain to a reference-body K' possessing any kind of motion, then relative to K' there exists a gravitational field which is variable with respect to space and time. 2 The character ofthis field will of course depend on the motion chosen for K'. According to the general theory of relativity, the general law of the gravitational field must be satisfied for all gravitational fields obtainable in this way. Even though by no means all gravitational fields can be produced in this way, yet we may entertain the hope that the general law of gravitation will be derivable from such gravitational fields of a special kind. This hope has been realised in the most beautiful manner. But between the clear vision of this goal and its actual realisation it was necessary to surmount a serious difficulty, and as this lies deep at the root of things, I dare not withhold it from the reader. We require to extend our ideas of the space-time continuum still farther.Note 1. By means of the star photographs of two expeditions equipped by a Joint Committee of the Royal and Royal Astronomical Societies, the existence of the deflection of light demanded by theory was confirmed during the solar eclipse of 29th May, 1919. (Cf. Appendix III.) [back] Note 2. This follows from a generalisation of the discussion in Section XX. [back]XXIII. Behaviour of Clocks and Measuring Rods on a。
广义相对论【英文】 General Relativity Presentation
The Equivalence Principle
• The equivalence principle is the fundamental underpinning of general relativity, it says that: • “There is no experiment that can be done in a small confined space that can detect the difference between a uniform gravitational field and an equivalent uniform acceleration.”
The History of GR
• By 1915 Einstein had developed what are known as the Einstein Field Equations
• General Theory of Relativity published in Annalen der Physik in 1916
The Motivations of GR
• The special theory of relativity encompasses inertial frames of reference moving at uniform relative velocities • Einstein asked whether or not systems moving in nonuniform motion with respect to one another could be relative and came up with the idea of general relativity
ARINC 625-1
QUALITY MANAGEMENT PROCESS FOR TEST PROCEDURE GENERATIONARINC REPORT 625-1PUBLISHED: OCTOBER 15, 1999AN DOCUMENTPrepared byAIRLINES ELECTRONIC ENGINEERING COMMITTEEPublished byAERONAUTICAL RADIO, INC.2551 RIVA ROAD, ANNAPOLIS, MARYLAND 21401Copyright© 1999 byAERONAUTICAL RADIO, INC.2551 Riva RoadAnnapolis, Maryland 21401-7465 USAARINC REPORT 625-1©QUALITY MANAGEMENT PROCESS FOR TEST PROCEDURE GENERATIONPublished: October 15, 1999Prepared by the Airlines Electronic Engineering CommitteeReport 625Adopted by the Airlines Electronic Engineering Committee:January 22, 1996 Report 625Adopted by the Industry: February 25, 1996Summary of Document SupplementsSupplement Adoption Date PublishedReport 625-1September 15, 1999October 15, 1999FOREWORDActivities of AERONAUTICAL RADIO, INC. (ARINC)and thePurpose of ARINC Reports and SpecificationsAeronautical Radio, Inc. is a corporation in which the United States scheduled airlines are the principal stockholders. Other stockholders include a variety of other air transport companies, aircraft manufacturers and non-U.S. airlines.Activities of ARINC include the operation of an extensive system of domestic and overseas aeronautical land radio stations, the fulfillment of systems requirements to accomplish ground and airborne compatibility, the allocation and assignment of frequencies to meet those needs, the coordination incident to standard airborne compatibility, the allocation and assignment of frequencies to meet those needs, the coordination incident to standard airborne communications and electronics systems and the exchange of technical information. ARINC sponsors the Airlines Electronic Engineering Committee (AEEC), composed of airline technical personnel. The AEEC formulates standards for electronic equipment and systems for the airlines. The establishment of Equipment Characteristics is a principal function of this Committee.It is desirable to reference certain general ARINC Specifications or Report which are applicable to more than one type of equipment. These general Specifications and Reports may be considered as supplementary to the Equipment Characteristics in which they are referenced. They are intended to set forth the desires of the airlines pertaining to components and general design, construction and test criteria, in order to insure satisfactory operation and the necessary interchangeability in airline service. The release of a Specification or Equipment Characteristics should not be construed to obligate ARINC or any airline insofar as the purchase of any components or equipment is concerned.An ARINC Report ( Specification or Characteristic) has a twofold purpose, which is:(1)To indicate to the prospective manufacturers of airline electronic equipment theconsidered opinion of the airline technical people, coordinated on an industry basis,concerning requisites of new equipment, and(2)To channel new equipment designs in a direction which can result in the maximumpossible standardization of those physical and electrical characteristics which influenceinterchangeability of equipment without seriously hampering engineering initiative.ii1.0INTRODUCTION1 1.1Overview1 1.2Background1 1.3Goals21.4Related Documents22.0ROLES AND RESPONSIBILITIES3 2.1Introduction3 2.2Airframe Manufacturer3 2.3LRU Manufacturer3 2.3.1TSDP Development Plan3 2.3.2Test Strategy and LRU Testability3 2.3.3Source Documentation3 2.3.4Scope of Return to Service Testing4 2.3.5Configuration Management4 2.3.6Source Documentation Updates4 2.3.7Problem Reporting System4 2.3.8Source Documentation Analysis4 2.4TPS Developer5 2.4.1TPS Development Plan5 2.4.1.1Design and Implementation5 2.4.1.2Verification and Validation5 2.4.1.3TPS Delivery6 2.4.2Quality Assurance Plan6 2.4.2.1Quality Records6 2.4.3Configuration Management Plan6 2.4.4TPS Sustaining Process6 2.5TPS User7 2.5.1Maintain TPS Integrity7 2.5.2Problem Reporting7 2.5.3TPS Conformance Checking7 2.5.4Acceptance of TPS7 2.5.5Configuration Control73.0TECHNICAL SUPPORT AND DATA PACKAGE8 3.1Introduction8 3.2LRU Manufacturer Supplied Data, Software, and Services8 3.2.1Data8 3.2.2Software9 3.2.3Services9 3.3Other Items (Outside TSDP)9 3.4Technical Support and Data Package Quality Attributes103.5The TSDP Checklist104.0TEST SPECIFICATION ATTRIBUTES11 4.1Introduction11 4.2General Requirements11 4.2.1Format11 4.2.2General Organization and Content11 4.2.2.1Configuration Preamble11 4.2.2.2Technical Preamble11 4.2.2.3Detailed Test Specification11 4.2.2.4Other Data11 4.2.3Content Requirements11 4.3Configuration Preamble Data11 4.3.1TS Configuration/Revision Information11 4.3.2Table of Contents11 4.3.3UUT Description12 4.3.4References12 4.4Technical Preamble12 4.4.1Test Strategy/General Information12 4.4.2Detailed UUT Performance Characteristics12 4.4.3Test Equipment Resource Requirements12 4.4.4Special Tool Requirements13 4.4.5Environmental Requirements13 4.4.6Test Vocabulary13 4.4.7Other Requirements13 4.4.8Non-Volatile Memory Requirements13 4.4.9Predefined Functions and Procedures13 4.5Detailed Test Specification13 4.5.1Detailed Test Information13iii4.5.2Detailed Test Requirement Criteria14 4.5.2.1Coverage14 4.5.2.2Purpose14 4.5.2.3Test Approach14 4.5.2.4Initial Conditions14 4.5.2.5Test Requirements14 4.6Test Specification Quality Attributes14 4.7Shop Verification of Test Specification14 4.8The TS Checklist155.0TPS QUALITY FACTORS AND ATTRIBUTES16 5.1Introduction16 5.2Correctness16 5.2.1Traceability Checklist16 5.2.2Safety Checklist16 5.2.3UUT/TUA/ATE Damage Protection16 5.2.4Consistency Checklist17 5.2.5Completeness Checklist17 5.2.6Functionality17 5.3Reliability18 5.3.1Robustness Checklist18 5.3.2Accuracy Checklist18 5.3.3Simplicity Checklist19 5.4Efficiency19 5.4.1Execution Time Checklist19 5.5Usability19 5.5.1Man-Machine Interface Checklist19 5.6Maintainability20 5.6.1Self-Descriptiveness Checklist20 5.6.2TUA Repairability Checklist216.0RECOMMENDED PROGRAMMING PRACTICE22 6.1Introduction22 6.1.1Purpose22 6.1.2Goals22 6.1.3Programming Practice Overview22 6.1.4Relationship Between TS and TPS22 6.2Test Program Development22 6.2.1The Benefits of a Standard Test Program Structure22 6.2.2Description of Operator Interface Procedures22 6.2.3Signal Oriented Procedures22 6.3Design Guidelines22 6.3.1Test Objectives22 6.3.2Preparation of Test Program Development23 6.3.3Proper Test Sequence23 6.3.4Test Program Maintainability23 6.3.4.1Configuration Control23 6.3.4.2Use of Commentary23 6.3.4.3Meaningful Labels23 6.3.4.4Test Organization23 6.3.4.5Data Conversion to Physical Units24 6.3.5Complete and Partial Test24 6.3.6Use of Entry Points24 6.3.7Diagnostics24 6.4Operator Interface24 6.4.1Operator Messages24 6.4.2PASS/FAIL Messages25 6.4.3Test Results Presentation Guideline25 6.4.4Long Test Executive Time257.0TPS CONFORMATION CHECKING PROCESS26 7.1Introduction26 7.2Framework26 7.2.1Error Correction26 7.3TPS Conformance Checking Segments26 7.3.1Phase I Conformance Check26 7.3.1.1Documentation Check26 7.3.1.2Resource Compliance26 7.3.1.3TPS Test Compliance27 7.3.1.4Safety Considerations27 7.3.1.5Deviations27iv7.3.1.6Implementation Details28 7.3.1.7Additional Tests28 7.3.2Phase II Conformance Check28 7.4Life Cycle Issues28 7.5Proof of Conformance28 7.5.1Conformance Checklist28 7.5.2Conformance Certificate29ATTACHMENTS1-1Glossary31-34 1-2TPS Process and Information Flow Diagram351-3Concurrent TPS Process and Information Flow Diagram361-4Data Package Requirements for Third Party ATE Development37-40 2Intentionally Left Blank413-1Technical Support and Data Package Checklist424-1Test Specification Quality Checklist43-49 5-1TPS Quality Checklist50-53 6-1Recommended Structure of TPS547-1Conformance Certificate557-2TPS Conformance Checklist56APPENDICESA Examples of Test Specification57-83B Example Test Specification Checklist84-91vARINC REPORT 625 - Page 1 1.0 INTRODUCTION1.1 OverviewThe purpose of this document is to provide a standard approach for quality management of Test Procedure Generation within the commercial air transport industry.This document defines the data, software, and services required to support development and maintenance of quality test solutions for aircraft components. These data, software, and services comprise the Technical Support and Data Package (TSDP). This document also provides a standard approach for defining a uniform quality management methodology for designing a Test Program Set (TPS) and a standard TPS Conformance Checking Process. A conformance certificate is defined that should be used as an industry standard.Refer to the glossary in Attachment 1-1 for definitions of terms.This document applies to Return-To-Service (RTS) testing and related processes including:ŸRoles and ResponsibilitiesŸTSDP ContentsŸTSDP Quality AttributesŸTPS Quality Factors and AttributesŸTPS ConformanceT he process as shown in Attachment 1-2 is divided into several phases. It shows the idealized flow of TPS development and update as an industrial process. There are standards and procedures defined to control the individual process elements of both a phase-dependent and phase -independent nature. These are shown on top of the TPS Process and Information Flow Diagram.A ll phases of the process are accompanied by quality assurance activities and associated quality records to generate a system of inherent control and monitoring. Quality records should be implemented in a suitable format to facilitate control in an unambiguous, complete, verifiable and consistent manner.A ttachment 1-3, the Concurrent TPS Process and Information Flow Diagram, is another representation of those processes identified in Attachment 1-2. This illustrates the phase dependent nature of a number of the processes when TPS development must be accomplished in conjunction with an airplane development program. In most instances, timely development of the desired TPS will depend on the successful implementation of the concurrent processes depicted.T he top block, labeled as Airframe Manufacturer, is representative of the airplane development process showing the various phases, from the initial definition, through the prototype, ground test, flight test, final development and delivery.T he LRU manufacturer block shows that the TPS development process is conducted multiple times as the design of the LRU evolves during the airframe development.T he TPS User and TPS Developer blocks shows how the original delivery and subsequent updates to the LRU data are used to support specific phases of the test procedure development effort. This figure represents multiple development efforts that may occur simultaneously.T he key to successful implementation of these concurrent processes is continuous flow of data between each party's processes, starting with the initial release of timely, but necessarily incomplete data, and finishing with a complete TSDP.A lthough this document is written with a heavy emphasis towards avionics and avionics ATE, the principals for a quality TPS and specification are applicable to all aircraft components that often need to be maintained beyond the life of the original test equipment, and also to manual tests.1.2 BackgroundTARINC 625 was to provide automatic test information in component maintenance manuals (CMMs) as test specifications written in ATLAS.A test specification, by definition, is a UUT-oriented, test-system-independent test description. It is not a test procedure. It is essential for a successful TPS quality management process to be based on the same test specifications that were used to develop the shop-verified test procedures contained in the CMMs.T esting of modern state-of-the-art avionics is often dependent on the utilization of built-in tests, external test data files, diagnostics/exercisers and other non-ATLAS test routines. Experience has shown that these essential parts of testing information were often missing and not even referenced in the ATLAS or CMMs.P rior to ARINC 625, there were no common guidelines for a quality management process for test procedure generation. This caused a severe quality problem for the aircraft manufacturer, equipment manufacturer, TPS developer, and finally, the airline user. In addition, it increased TPS cycle costs for all parties involved.C OMMENTARYT he automatic test documentation standard required for the CMM test procedures was ATLAS 616/626.The information provided with the ATLAS test specification was generally considered to be sufficient (by the LRU manufacturer and others) for an implementation on alternate test equipment hardware (ATEs). This simple, basic concept is shown in Attachment 1-4 Figure 1.A lternatives to the ATLAS (e.g. “plain English testspecification”) often were not available from, or provided by, LRU manufacturers. Experience has shown that ATLAS procedures or specifications alone cannot represent the complete set ofARINC REPORT 625 - Page 21.0 INTRODUCTION (cont’d)1.2 Background (cont’d)C OMMENTARY (cont’d)i nformation needed as the source documentation fortest procedure rehost.T hese inadequacies resulted in ever-increasing demands on airframe and LRU manufacturer’s for additional data to support both TPS development and the increasing burden of TPS certification. This increasing demand is depicted in Attachment 1-4 Figures 2 through 4.B ased on airline experience, the quality of testspecifications and test information in the CMMs has proven to be, in many cases, insufficient to support test procedure rehost for the following reasons:ŸTest specifications sometimes contained vague test objectives and guidelines and were full oferrors and not mature.ŸSome LRU manufacturers would not supply an internal test specification when ATLAS was notavailable.ŸManufacturing test requirements were sometimes too different from Return-To-Service(RTS) requirements.ŸDissimilar test concepts made communication and understanding difficult.ŸExternal data files were sometimes not available or documented and were not always referencedin the ATLAS test specification or the CMM.ŸATLAS test specifications were not available in time; updates are too late.ŸThe LRU manufacturers found the cost of producing ATLAS excessive.ŸATLAS development was often subcontracted by LRU manufacturers to TPS developers but notsufficiently controlled, verified, and validated.ŸATLAS test specifications were not fully transportable because necessary implementationinformation was missing.ŸAirlines often found the cost of implementing and maintaining ATLAS-based TPSs excessive.1.3 GoalsTest procedure quality is complex and multi-dimensional. The goal of this report is to provide guidelines and standard procedures for both the TSDP and TPS development.These guidelines and procedures are expected to serve as a standard approach for defining a uniform quality management methodology. This report was developed by an industry wide committee with the objective of encouraging conformity at all stages of the LRU life cycle.The application of these guidelines and procedures will improve the overall quality of LRU maintenance and also have the potential to considerably reduce the TPS life cycle cost for all parties involved.COMMENTARYWhile the importance of overall test solution quality management is recognized, this document will emphasize design and documentation quality issues.It will not discuss workmanship quality issues such as soldering or wiring layout.The current standards for documentation, procedures, development, verification, and validation vary throughout industry. Quality problems are typically caused by poor documentation, different methodologies, philosophies, and insufficient communication. The intent of this report is to improve the communication and understanding between airframe manufacturers, LRU manufacturers, TPS suppliers, and airlines. To demonstrate that testing performed by all parties conforms to the same specifications, common rules for development and implementation of alternate tests, and associated quality assurance procedures should be followed.It is expected that all parties involved in testing will benefit from common standards and philosophies.Test procedure quality improvement can only be realized in an industry environment of cooperation regarding test concepts of airframe manufacturers, equipment manufacturers, and airlines.1.4 Related DocumentsATA Specification 100, “Specification for Manufacturers' Technical Data”ATA World Airlines & Suppliers GuideIEEE Standard 100, “Standard Dictionary of Electrical and Electronic Terms”ARINC Specification 616, “Avionics Subset of ATLAS Language”ARINC Specification 626, “Standard ATLAS for Modular Test”ARINC REPORT 625 - Page 3 2.0 ROLES AND RESPONSIBILITIES2.1 IntroductionThe roles and responsibilities as listed in this section do not necessarily coincide with organizational entities. For example, an airline may be both a TPS developer and a TPS user, while airframe manufacturers may serve in all four roles for those LRUs they build themselves.2.2 Airframe ManufacturerThe airframe manufacturer should ensure the LRU manufacturers selected conform to the guidelines of this document. This includes a contractually-defined, supplier provided and airframe manufacturer-approved TSDP Development Plan.The airframe manufacturer should ensure that LRU manufacturers prepare and follow a TSDP Development Plan during the entire LRU lifecycle by the following methods:ŸDocumentation reviewsŸAudits as neededŸProgress report reviewsŸOther communications as necessary (phone, fax, e-mail, visits, etc.).T he intent of the above is to ensure that the airframe manufacturer and the LRU manufacturer work together to produce and deliver a complete, fully supported, TSDP to a customer airline on time.C OMMENTARYA irline experience has shown that firm requirementsfor the level of detail and quality of documentation to be delivered by LRU manufacturers to airlines and TPS developers should be established very early in the aircraft development program, i.e. airframe manufacturers should include relevant clauses in their contracts with the LRU manufacturers. If this opportunity is missed, additional information requested by airlines and TPS developers later in the program is often considered as proprietary data. The information then is either not available or is charged for by the LRU manufacturer. Additionally, the airframe manufacturer should improve vendor monitoring to make sure that contract terms are honored.2.3 LRU ManufacturerT he LRU manufacturer is responsible for the testability of the LRU, test strategies, and for implementing the TSDP Development Plan. The LRU manufacturer should define and document their policy and objectives for, and commitment to, the quality of LRU test data required for TSDP and TPS generation. The LRU manufacturer should ensure that this policy is understood, implemented, and maintained at all levels in their organization.2.3.1 TSDP Development PlanT he TSDP Development Plan should include the following:ŸSufficient resource allocation (facilities, personnel, equipment)ŸReasonable milestones and schedules for releaseŸDefinition of source documentation (data, software, services)Ÿ A quality assurance processŸ A configuration management processŸ A periodic report of progress being made, any projected schedule slips and recovery plan.ŸTSDP sustaining process2.3.2 Test Strategy and LRU TestabilityT he test strategy design should be an integral part of the overall design/development process of the LRU. This ensures that the test specifications and procedures used at the manufacturer for production are not too different from what is needed as source documentation for the later TPS development. This facilitates cost-effective information transfer for the equipment manufacturer and better understanding in case problems may arise during TPS development.T esting technology should be a basic part of the LRU design process. It should include consideration of traditional design for testability techniques, boundary scan, BITE, etc. Design techniques which promote testability should be developed along with the ability to predict and demonstrate testability quantitatively.L RUs that include BITE should be tested in a manner that efficiently utilizes these testing aids, i.e. test sequences should be structured according to the BITE information for more effective troubleshooting. Wherever possible, the manufacturer should design the test strategy such that the return-to-service test is a subset of the procedures developed for the factory acceptance test.2.3.3 Source DocumentationTaccurate, and unambiguous documentation sufficient to implement the LRU return-to-service test. A detailed list of items and attributes needed in the source documentation is contained in Section 3. Emphasis should be placed on the content of the test source documentation rather than the format.T his documentation should be supplied in time for the TPS developer to finish the TPS prior to first LRU delivery to the customer airline. In the special case of a brand new LRU design, or the even more special case of a new aircraft type, the LRU manufacturer should provide preliminary information to the TPS developer. These relationships are illustrated in Attachment 1-3,ARINC REPORT 625 - Page 42.0 ROLES AND RESPONSIBILITIES (cont’d)2.3.3 Source Documentation (cont’d)C oncurrent TPS Process and Information Flow Diagram.C OMMENTARYT he LRU manufacturer, through the contents of the source documentation, establishes the TPS quality potential. A job done poorly on the source documentation will tend to have a negative impact on the cost and quality of the subsequent TPS. It is critical that the source documentation be of the highest possible quality to assure a high quality TPS.For this reason, the LRU manufacturer is responsible for the configuration management of the source documentation. In addition, the LRU manufacturer should have a test problem reporting system to provide TPS developers a forum for data problem resolution.T he LRU manufacturer will ensure that the source documentation is shop-verified and will provide a completed checklist as defined by Section 3.5.C OMMENTARYT he source documentation quality is the most critical issue in the TPS life cycle, since most of the shortfalls of the source documentation are carried through the whole development process and can later be found in the TPS product. Generally, it is very expensive to cure problems late in the development that have been present since the very beginning.S ource documentation quality has been poor and should be improved. When the LRU manufacturer does not supply necessary source data, it must be developed through reverse engineering that is both difficult and expensive.S ome of the information needed for TPS development is often withheld. The rationale for this varies. Some LRU manufacturers believe they are not obligated to spend more effort than their contractual obligations demand. Others are reluctant to provide information because they prefer to promote their own dedicated test equipment.2.3.4 Scope of Return to Service TestingT he purpose of the return-to-service test is limited to determining whether the hardware is working correctly and whether the correct version of software is installed and not corrupted. For modern avionics, the scope for return-to-service tests (RTS) should be limited to hardware testing and software integrity checks. Furthermore, certain manufacturing tests, such as dielectric tests or environmental stress screening tests, should not be part of subsequent return to service testing.I n the interest of minimum testing times, the return-to-service test should not include any steps whose purpose is to verify the LRU design; that should be done only once, prior to LRU certification. Each test requirement should be carefully scrutinized. If a test is needed for design verification rather than for return to service testing, it should be omitted.D epending on the targeted level of maintenance to be provided, extra test steps may be needed to identify the faulty component in an LRU that fails the go/nogo test. These fault isolation steps should be optional and not part of the go/nogo test path. The test specification should be designed to detect any fault capable of being propagated to an output.C OMMENTARYT he terminology for return-to-service testing ranges from “Recertification Test,” “Serviceability Test,” to “Acceptance Test.” There might be even more names for the same thing.S imilar equipment from different LRU manufacturers is sometimes treated with different philosophies and test methods (e.g. different environmental test requirements for engine controls). This should be minimized by making sure that no tests are performed that do not have a specific bearing on the serviceability of the LRU such as weight. Additionally, specify the widest acceptable environmental conditions.2.3.5 Configuration ManagementT he LRU manufacturer should have a configuration management system that controls the source documentation.2.3.6 Source Documentation UpdatesT he LRU manufacturer should ensure that if change occurs in the source documentation that impacts existing TPSs, then this TPS change must be reflected within the TSDP and CMM. Revised source documentation elements should be available on request (to the airline).C OMMENTARYC hanges to source documentation generally are notavailable on time due to the long revision cycle of CMMs. Traceability is often lost without a clear reference to the new test specification or documentation of the changes in the service bulletin.2.3.7 Problem Reporting SystemT he LRU manufacturer should maintain a test problem reporting system that enables users of the source documentation to report problems and request corrective action.2.3.8 Source Documentation AccuracyT he LRU manufacturer is responsible for the technical content and accuracy of the TSDP. Detailed requirements are shown in Section 3 and a checklist is provided in Attachment 3-1. A copy of the checklist should be provided to the TPS developer.C OMMENTARYI t is understood that testing information providedprior to formal certification of the LRU being tested may not be in final form and subject to substantial change. This precertification information is provided with the understanding that the supplier is not obligated for the stability and completeness of the information. It is further understood this information will not be distributed without a direct request from an airline customer.2.4TPS DeveloperT PS developers should define and document their policy and objectives for, and commitment to, TPS quality. TPS developers should ensure that this policy is understood, implemented, and maintained at all levels in their organizations.T he TPS developer is responsible to provide to the user the following:ŸTPS Development PlanŸQuality Assurance PlanŸConfiguration Management PlanŸTPS Sustaining ProcessThe TPS developer should establish and maintain a documented quality system, which should cover quality assurance and configuration management aspects, and should be an integrated process throughout the TPS life cycle, thus ensuring that quality is being built into the TPS product. The prevention of problems should be emphasized rather than the correction of problems after they occur.The TPS developer should ensure the effective implementation of a documented quality system, including procedures for documentation, quality plans, internal quality system audits, configuration management, and problem reporting. Test problem reports should be traceable to the TPS configuration management system and to the TSDP, if applicable.LRU manufacturers providing initial TPSs to the airframe manufacturer and airline customers should produce the test solution based on the LRU manufacturer’s internal quality standards. The LRU manufacturer’s quality system is governed by airframe manufacturer’s quality system requirements. Third party TPS developers typically are not governed by airframe manufacturers quality systems. The roles and responsibilities for the TPS developer outlined in this section refer to third party TPS developers.The TPS developer should offer appropriate training to assure efficient and correct use of the TPS.2.4.1 TPS Development PlanThe TPS developer should begin with a clear understanding of the requirements of the TPS user. The development plan should include at least the following activities:•TPS design•TPS implementation•TPS verification•TPS validation•TPS delivery2.4.1.1 Design and ImplementationDue to the complexity of TPSs, all steps of design and implementation should be performed in a disciplined manner in order to be able to build quality into the product. Feedback from past design experiences is important to improve quality of the new design. The design definition should also recognize the subsequent processes during the TPS life cycle, e.g., TPS maintainability and usability. Guidelines are contained in Section 6.TUA design should strive for minimum complexity. Active circuits should be avoided if at all possible. Usability details such as handles properly located with respect to the center of gravity, proper cable strain relief, ease of maintenance access, etc, should not be overlooked.2.4.1.2 Verification and ValidationVerification and Validation are the processes by which the TPS developer verifies the TPS works correctly. Verification concerns the process of examining the result of each one of the development phases (TPS design, TPS implementation, etc.) to determine conformity with the stated requirements for that activity.Validation is the act of demonstrating that a TPS is capable of fulfilling the requirements for which it has been designed. The minimum requirements are those defined by the Test Specification (TS) but also may include any additional requirements imposed by the TPS User or TPS Developer. The validation process should use a formal procedure and should produce documented test results.COMMENTARYIf possible, validation should involve multiple LRUs tested on multiple ATE stations. (This is normally not possible unless the TPS developer is also the LRU manufacturer and has access to multiple LRU assemblies and multiple test stations.) The procedure and the results should be available to the TPS user, unless otherwise specified in the TPS purchase contract.In some cases, testing an unreleased TPS using a cooperative airline has been shown to strengthen the quality of that TPS.。
药品共线生产质量管理指南英文
药品共线生产质量管理指南英文英文回答：Good Manufacturing Practices for Pharmaceutical Bulk Production.Introduction.The pharmaceutical industry is highly regulated, andfor good reason. The products manufactured by this industry are used to treat and prevent diseases, and the safety and efficacy of these products are paramount. Good Manufacturing Practices (GMPs) are a set of regulationsthat are designed to ensure that pharmaceutical products are produced in a safe and consistent manner.GMPs cover all aspects of pharmaceutical production, from the sourcing of raw materials to the packaging and distribution of finished products. They include requirements for:Quality control.Production and process validation.Equipment maintenance and calibration.Personnel training.Documentation and record keeping.GMPs are essential for ensuring the safety and efficacy of pharmaceutical products. By adhering to GMPs, manufacturers can help to prevent contamination, errors, and other problems that could compromise the quality of their products.Quality Control.Quality control is a critical aspect of GMPs. It involves testing raw materials, in-process products, and finished products to ensure that they meet specifications.Quality control testing can be used to identify and prevent problems in the manufacturing process.Production and Process Validation.Production and process validation are also essentialfor GMPs. Validation is the process of demonstrating that a manufacturing process is capable of consistently producing a product that meets specifications. This involves testing the process under different conditions to ensure that it is robust and reliable.Equipment Maintenance and Calibration.Equipment maintenance and calibration are also important for GMPs. Equipment that is not properly maintained or calibrated can lead to errors in the manufacturing process. This can compromise the safety and efficacy of the products produced.Personnel Training.Personnel training is also essential for GMPs. Personnel must be trained on all aspects of GMPs, including quality control, production, and process validation. This training helps to ensure that personnel understand the importance of GMPs and that they are able to follow them correctly.Documentation and Record Keeping.Documentation and record keeping are also important for GMPs. Documentation provides a record of all activitiesthat are involved in the manufacturing process. This documentation can be used to track problems, identify trends, and improve the manufacturing process.Conclusion.GMPs are a set of regulations that are designed to ensure that pharmaceutical products are produced in a safe and consistent manner. By adhering to GMPs, manufacturers can help to prevent contamination, errors, and other problems that could compromise the quality of theirproducts.中文回答：药物共线生产质量管理指南。
the principle of relativity
ON THE ELECTRODYNAMICSOF MOVING BODIESBy A. EinsteinJune 30, 1905It is known that Maxwell's electrodynamics--as usually understood at the present time--when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena. Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion. For if the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated. But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy, but which gives rise--assuming equalityof relative motion in the two cases discussed--to electric currents of the same path and intensity as those produced by the electric forces in the former case.Examples of this sort, together with the unsuccessful attempts to discover any motion of the earth relatively to the ``light medium,'' suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest. They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good.1 We will raise this conjecture (the purport of which will hereafter be called the ``Principle of Relativity'') to the status of a postulate, and also introduce another postulate, which is only apparently irreconcilable with the former, namely, that light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body. These two postulates suffice for the attainment of a simple and consistent theory of the electrodynamics of moving bodies based on Maxwell's theory for stationary bodies. The introduction of a ``luminiferous ether'' will prove to be superfluous inasmuchas the view here to be developed will not require an ``absolutely stationary space'' provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place.The theory to be developed is based--like all electrodynamics--on the kinematics of the rigid body, since the assertions of any such theory have to do with the relationships between rigid bodies (systems of co-ordinates), clocks, and electromagnetic processes. Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters.I. KINEMATICAL PART?1. Definition of SimultaneityLet us take a system of co-ordinates in which the equations of Newtonian mechanics hold good.2In order to render our presentation more precise and to distinguish this system of co-ordinates verbally from others which will be introduced hereafter, we call it the ``stationary system.''If a material point is at rest relatively to this system of co-ordinates, its position can be defined relatively theretoby the employment of rigid standards of measurement and the methods of Euclidean geometry, and can be expressed in Cartesian co-ordinates.If we wish to describe the motion of a material point, we give the values of its co-ordinates as functions of the time. Now we must bear carefully in mind that a mathematical description of this kind has no physical meaning unless we are quite clear as to what we understand by ``time.'' We have to take into account that all our judgments in which time plays a part are always judgments of simultaneous events. If, for instance, I say, ``That train arrives here at 7 o'clock,'' I mean something like this: ``The pointing of the small hand of my watch to 7 and the arrival of the train are simultaneous events.''3It might appear possible to overcome all the difficulties attending the definition of ``time'' by substituting ``the position of the small hand of my watch'' for ``time.'' And in fact such a definition is satisfactory when we are concerned with defining a time exclusively for the place where the watch is located; but it is no longer satisfactory when we have to connect in time series of events occurring at different places,or--what comes to the same thing--to evaluate the times of events occurring at places remote from the watch.We might, of course, content ourselves with time values determined by an observer stationed together with the watch at the origin of the co-ordinates, and co-ordinating the corresponding positions of the hands with light signals, given out by every event to be timed, and reaching him through empty space. But this co-ordination has the disadvantage that it is not independent of the standpoint of the observer with the watch or clock, as we know from experience. We arrive at a much more practical determination along the following line of thought. If at the point A of space there is a clock, an observer at A can determine the time values of events in the immediate proximity of A by finding the positions of the hands which are simultaneous with these events. If there is at the point B of space another clock in all respects resembling the one at A, it is possible for an observer at B to determine the time values of events in the immediate neighbourhood of B. But it is not possible without further assumption to compare, in respect of time, an event at A with an event at B. We have so far defined only an ``A time'' and a ``B time.'' We have not defined a common``time'' for A and B, for the latter cannot be defined at all unless we establish by definition that the ``time'' required by light to travel from A to B equals the ``time'' it requires to travel from B to A. Let a ray of light start at the ``A time'' from A towards B, let it at the ``B time'' be reflected at B in the direction of A, and arrive again at A at the ``A time''.In accordance with definition the two clocks synchronize ifWe assume that this definition of synchronism is free from contradictions, and possible for any number of points; and that the following relations are universally valid:--1.If the clock at B synchronizes with the clock at A, theclock at A synchronizes with the clock at B.2.If the clock at A synchronizes with the clock at B and alsowith the clock at C, the clocks at B and C also synchronize with each other.Thus with the help of certain imaginary physical experiments we have settled what is to be understood by synchronous stationary clocks located at different places, and haveevidently obtained a definition of ``simultaneous,'' or ``synchronous,'' and of ``time.'' The ``time'' of an event is that which is given simultaneously with the event by a stationary clock located at the place of the event, this clock being synchronous, and indeed synchronous for all time determinations, with a specified stationary clock.In agreement with experience we further assume the quantityto be a universal constant--the velocity of light in empty space.It is essential to have time defined by means of stationary clocks in the stationary system, and the time now defined being appropriate to the stationary system we call it ``the time of the stationary system.''?2. On the Relativity of Lengths and TimesThe following reflexions are based on the principle of relativity and on the principle of the constancy of the velocity of light. These two principles we define as follows:--1.The laws by which the states of physical systems undergochange are not affected, whether these changes of statebe referred to the one or the other of two systems ofco-ordinates in uniform translatory motion.2.Any ray of light moves in the ``stationary'' system ofco-ordinates with the determined velocity c, whether theray be emitted by a stationary or by a moving body. Hencewhere time interval is to be taken in the sense of thedefinition in ?1.Let there be given a stationary rigid rod; and let its length be l as measured by a measuring-rod which is also stationary. We now imagine the axis of the rod lying along the axis of x of the stationary system of co-ordinates, and that a uniform motion of parallel translation with velocity v along the axis of x in the direction of increasing x is then imparted to the rod. We now inquire as to the length of the moving rod, and imagine its length to be ascertained by the following two operations:--(a)The observer moves together with the givenmeasuring-rod and the rod to be measured, and measuresthe length of the rod directly by superposing themeasuring-rod, in just the same way as if all threewere at rest.(b)By means of stationary clocks set up in the stationarysystem and synchronizing in accordance with ?1, theobserver ascertains at what points of the stationarysystem the two ends of the rod to be measured arelocated at a definite time. The distance between thesetwo points, measured by the measuring-rod alreadyemployed, which in this case is at rest, is also alength which may be designated ``the length of therod.''In accordance with the principle of relativity the length to be discovered by the operation (a)--we will call it ``the length of the rod in the moving system''--must be equal to the length l of the stationary rod.The length to be discovered by the operation (b) we will call ``the length of the (moving) rod in the stationary system.''This we shall determine on the basis of our two principles, and we shall find that it differs from l.Current kinematics tacitly assumes that the lengths determined by these two operations are precisely equal, or in other words, that a moving rigid body at the epoch t may in geometrical respects be perfectly represented by the same body at rest in a definite position.We imagine further that at the two ends A and B of the rod, clocks are placed which synchronize with the clocks of the stationary system, that is to say that their indications correspond at any instant to the ``time of the stationary system'' at the places where they happen to be. These clocks are therefore ``synchronous in the stationary system.''We imagine further that with each clock there is a moving observer, and that these observers apply to both clocks the criterion established in ?1 for the synchronization of two clocks. Let a ray of light depart from A at the time4, let it be reflected at B at the time , and reach A again at the time . Taking into consideration the principle of the constancy of the velocity of light we find thatwhere denotes the length of the moving rod--measured in the stationary system. Observers moving with the moving rod would thus find that the two clocks were not synchronous, while observers in the stationary system would declare the clocks to be synchronous.So we see that we cannot attach any absolute signification to the concept of simultaneity, but that two events which, viewed from a system of co-ordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relatively to that system. ?3. Theory of the Transformation of Co-ordinates and Times from a Stationary System to another System in Uniform Motion ofTranslation Relatively to the FormerLet us in ``stationary'' space take two systems of co-ordinates, i.e. two systems, each of three rigid material lines, perpendicular to one another, and issuing from a point. Let the axes of X of the two systems coincide, and their axes of Y and Z respectively be parallel. Let each system be provided with a rigid measuring-rod and a number of clocks, and let thetwo measuring-rods, and likewise all the clocks of the two systems, be in all respects alike.Now to the origin of one of the two systems (k) let a constant velocity v be imparted in the direction of the increasing x of the other stationary system (K), and let this velocity be communicated to the axes of the co-ordinates, the relevant measuring-rod, and the clocks. To any time of the stationary system K there then will correspond a definite position of the axes of the moving system, and from reasons of symmetry we are entitled to assume that the motion of k may be such that the axes of the moving system are at the time t (this ``t'' always denotes a time of the stationary system) parallel to the axes of the stationary system.We now imagine space to be measured from the stationary system K by means of the stationary measuring-rod, and also from the moving system k by means of the measuring-rod moving with it; and that we thus obtain the co-ordinates x, y, z, and , , respectively. Further, let the time t of the stationary system be determined for all points thereof at which there are clocks by means of light signals in the manner indicated in ?1; similarly let the time of the moving system be determined forall points of the moving system at which there are clocks at rest relatively to that system by applying the method, given in ?1, of light signals between the points at which the latter clocks are located.To any system of values x, y, z, t, which completely defines the place and time of an event in the stationary system, there belongs a system of values , , , , determining that event relatively to the system k, and our task is now to find the system of equations connecting these quantities.In the first place it is clear that the equations must be linear on account of the properties of homogeneity which we attribute to space and time.If we place x'=x-vt, it is clear that a point at rest in the system k must have a system of values x', y, z, independent of time. We first define as a function of x', y, z, and t. To do this we have to express in equations that is nothing else than the summary of the data of clocks at rest in system k, which have been synchronized according to the rule given in ?1. From the origin of system k let a ray be emitted at the time along the X-axis to x', and at the time be reflected thenceto the origin of the co-ordinates, arriving there at the time ; we then must have , or, by inserting the arguments of the function and applying the principle of the constancy of the velocity of light in the stationary system:--Hence, if x' be chosen infinitesimally small,orIt is to be noted that instead of the origin of the co-ordinates we might have chosen any other point for the point of origin of the ray, and the equation just obtained is therefore valid for all values of x', y, z.An analogous consideration--applied to the axes of Y and Z--it being borne in mind that light is always propagated along these axes, when viewed from the stationary system, with the velocity gives usSince is a linear function, it follows from these equations thatwhere a is a function at present unknown, and where for brevity it is assumed that at the origin of k, , when t=0.With the help of this result we easily determine the quantities , , by expressing in equations that light (as required by the principle of the constancy of the velocity of light, in combination with the principle of relativity) is also propagated with velocity c when measured in the moving system. For a ray of light emitted at the time in the direction of the increasingBut the ray moves relatively to the initial point of k, when measured in the stationary system, with the velocity c-v, so thatIf we insert this value of t in the equation for , we obtainIn an analogous manner we find, by considering rays moving along the two other axes, thatwhenThusSubstituting for x' its value, we obtainwhereand is an as yet unknown function of v. If no assumption whatever be made as to the initial position of the moving system and as to the zero point of , an additive constant is to be placed on the right side of each of these equations.We now have to prove that any ray of light, measured in the moving system, is propagated with the velocity c, if, as we have assumed, this is the case in the stationary system; for we have not as yet furnished the proof that the principle of the constancy of the velocity of light is compatible with the principle of relativity.At the time , when the origin of the co-ordinates is common to the two systems, let a spherical wave be emitted therefrom, and be propagated with the velocity c in system K. If (x, y, z) be a point just attained by this wave, thenx2+y2+z2=c2t2.Transforming this equation with the aid of our equations of transformation we obtain after a simple calculationThe wave under consideration is therefore no less a spherical wave with velocity of propagation c when viewed in the moving system. This shows that our two fundamental principles are compatible.5In the equations of transformation which have been developed there enters an unknown function of v, which we will now determine.For this purpose we introduce a third system of co-ordinates , which relatively to the system k is in a state of parallel translatory motion parallel to the axis of ,*1 such that the origin of co-ordinates of system , moves with velocity -v on the axis of . At the time t=0 let all three origins coincide, and when t=x=y=z=0 let the time t' of the system be zero. We call the co-ordinates, measured in the system , x', y', z', and by a twofold application of our equations of transformation we obtainSince the relations between x', y', z' and x, y, z do not contain the time t, the systems K and are at rest with respectto one another, and it is clear that the transformation from K to must be the identical transformation. ThusWe now inquire into the signification of . We give our attention to that part of the axis of Y of system k which lies between and . This part of the axis of Y is a rod moving perpendicularly to its axis with velocity v relatively to system K. Its ends possess in K the co-ordinatesandThe length of the rod measured in K is therefore ; and this gives us the meaning of the function . From reasons of symmetry it is now evident that the length of a given rod moving perpendicularly to its axis, measured in the stationary system, must depend only on the velocity and not on the direction and the sense of the motion. The length of the moving rod measuredin the stationary system does not change, therefore, if v and -v are interchanged. Hence follows that , orIt follows from this relation and the one previously found that , so that the transformation equations which have been found becomewhere?4. Physical Meaning of the Equations Obtained in Respect to Moving Rigid Bodies and Moving ClocksWe envisage a rigid sphere6 of radius R, at rest relatively to the moving system k, and with its centre at the origin of co-ordinates of k. The equation of the surface of this sphere moving relatively to the system K with velocity v isThe equation of this surface expressed in x, y, z at the time t=0 isA rigid body which, measured in a state of rest, has the form of a sphere, therefore has in a state of motion--viewed from the stationary system--the form of an ellipsoid of revolution with the axesThus, whereas the Y and Z dimensions of the sphere (and therefore of every rigid body of no matter what form) do not appear modified by the motion, the X dimension appears shortened in the ratio , i.e. the greater the value of v, the greater the shortening. For v=c all moving objects--viewed from the ``stationary'' system--shrivel up into plane figures.*2For velocities greater than that of light our deliberations become meaningless; we shall, however, find in what follows, that the velocity of light in our theory plays the part, physically, of an infinitely great velocity.It is clear that the same results hold good of bodies at rest in the ``stationary'' system, viewed from a system in uniform motion.Further, we imagine one of the clocks which are qualified to mark the time t when at rest relatively to the stationary system, and the time when at rest relatively to the moving system, to be located at the origin of the co-ordinates of k, and so adjusted that it marks the time . What is the rate of this clock, when viewed from the stationary system?Between the quantities x, t, and , which refer to the position of the clock, we have, evidently, x=vt andTherefore,whence it follows that the time marked by the clock (viewed in the stationary system) is slow by seconds per second, or--neglecting magnitudes of fourth and higher order--by .From this there ensues the following peculiar consequence. If at the points A and B of K there are stationary clocks which, viewed in the stationary system, are synchronous; and if the clock at A is moved with the velocity v along the line AB to B, then on its arrival at B the two clocks no longer synchronize, but the clock moved from A to B lags behind the other which has remained at B by (up to magnitudes of fourth and higher order), t being the time occupied in the journey from A to B. It is at once apparent that this result still holds good if the clock moves from A to B in any polygonal line, and also when the points A and B coincide.If we assume that the result proved for a polygonal line is also valid for a continuously curved line, we arrive at this result: If one of two synchronous clocks at A is moved in a closed curve with constant velocity until it returns to A, the journey lasting t seconds, then by the clock which has remained at rest the travelled clock on its arrival at A will be second slow. Thence we conclude that a balance-clock7 at the equator must go more slowly, by a very small amount, than a precisely similar clock situated at one of the poles under otherwise identical conditions.?5. The Composition of VelocitiesIn the system k moving along the axis of X of the system K with velocity v, let a point move in accordance with the equationswhere and denote constants.Required: the motion of the point relatively to the system K. If with the help of the equations of transformation developed in ?3we introduce the quantities x, y, z, t into the equations of motion of the point, we obtainThus the law of the parallelogram of velocities is valid according to our theory only to a first approximation. We set*3a is then to be looked upon as the angle between the velocities v and w. After a simple calculation we obtain*4It is worthy of remark that v and w enter into the expression for the resultant velocity in a symmetrical manner. If w also has the direction of the axis of X, we getIt follows from this equation that from a composition of two velocities which are less than c, there always results a velocity less than c. For if we set , and being positive and less than c, thenIt follows, further, that the velocity of light c cannot be altered by composition with a velocity less than that of light. For this case we obtainWe might also have obtained the formula for V, for the case when v and w have the same direction, by compounding two transformations in accordance with ?3. If in addition to the systems K and k figuring in ?3we introduce still another system of co-ordinates k' moving parallel to k, its initial point moving on the axis of *5with the velocity w, we obtain equations between the quantities x, y, z, t and the corresponding quantities of k', which differ from the equations found in ?3 only in that the place of ``v'' is taken by the quantityfrom which we see that such parallel transformations--necessarily--form a group.We have now deduced the requisite laws of the theory of kinematics corresponding to our two principles, and we proceed to show their application to electrodynamics.II. ELECTRODYNAMICAL PART?6. Transformation of the Maxwell-Hertz Equations for Empty Space. On the Nature of the Electromotive Forces Occurring ina Magnetic Field During MotionLet the Maxwell-Hertz equations for empty space hold good for the stationary system K, so that we havewhere (X, Y, Z) denotes the vector of the electric force, and (L, M, N) that of the magnetic force.If we apply to these equations the transformation developed in ?3, by referring the electromagnetic processes to the system of co-ordinates there introduced, moving with the velocity v, we obtain the equationswhereNow the principle of relativity requires that if the Maxwell-Hertz equations for empty space hold good in system K,they also hold good in system k; that is to say that the vectors of the electric and the magnetic force--(, , ) and (, , )--of the moving system k, which are defined by their ponderomotive effects on electric or magnetic masses respectively, satisfy the following equations:--Evidently the two systems of equations found for system k must express exactly the same thing, since both systems of equations are equivalent to the Maxwell-Hertz equations for system K. Since, further, the equations of the two systems agree, with the exception of the symbols for the vectors, it follows that the functions occurring in the systems of equations at corresponding places must agree, with the exception of a factor , which is common for all functions of the one system of equations, and is independent of and but depends upon v. Thus we have the relationsIf we now form the reciprocal of this system of equations, firstly by solving the equations just obtained, and secondly by applying the equations to the inverse transformation (from k to K), which is characterized by the velocity -v, it follows, when we consider that the two systems of equations thus obtained must be identical, that . Further, from reasons of symmetry8 and thereforeand our equations assume the formAs to the interpretation of these equations we make the following remarks: Let a point charge of electricity have the magnitude ``one'' when measured in the stationary system K, i.e. let it when at rest in the stationary system exert a force of one dyne upon an equal quantity of electricity at a distance of one cm. By the principle of relativity this electric charge is also of the magnitude ``one'' when measured in the moving system. If this quantity of electricity is at rest relatively to the stationary system, then by definition the vector (X, Y,Z) is equal to the force acting upon it. If the quantity of electricity is at rest relatively to the moving system (at least at the relevant instant), then the force acting upon it, measured in the moving system, is equal to the vector (, , ). Consequently the first three equations above allow themselves to be clothed in words in the two following ways:--1.If a unit electric point charge is in motion in anelectromagnetic field, there acts upon it, in addition to the electric force, an ``electromotive force'' which, if we neglect the terms multiplied by the second and higher powers of v/c, is equal to the vector-product of the velocity of the charge and the magnetic force, divided by the velocity of light. (Old manner of expression.)2.If a unit electric point charge is in motion in anelectromagnetic field, the force acting upon it is equal to the electric force which is present at the locality of the charge, and which we ascertain by transformation of the field to a system of co-ordinates at rest relatively to the electrical charge. (New manner of expression.) The analogy holds with ``magnetomotive forces.'' We see that electromotive force plays in the developed theory merely the。
General introduction
to treat disorders of the local area and of nearby tissue and organs
all the acupoints, especially the acupoints located on the head,face and trunk
to treat disorders of the local regular acupoints,
Luo-Connecting acupoints
1.definition:
the points where the fifteen collaterals stem from the twelve meridians, the governor and conception vessels as well as the major collateral of the spleen.
1.Local and adjacent therapeutic properties 2.Remote therapeutic properties 3.Special therapeutic properties
therapeutic property local
remote
special
feature of treatment suitable points
Location:All the Xi-Cleft acupoints located below the knees and elbows., except Liangqiu (ST 34) on the stomach meridian,
2. Functions:
Clinically to treat severe acute disorders of the meridians.
英语演讲稿：General Introduction三篇
英语演讲稿：General Introduction三篇演讲稿一：一般介绍Ladies and gentlemen,Good morning/afternoon/evening! It is my great pleasure to stand here today and introduce myself to all of you. My name is [Your Name] and I am from [Your Country/City]. I am honored to have this opportunity to share a little bit about myself with you.I am currently a [Your Occupation/Profession]. I have been working in this field for [Number of Years] and have gained valuable experience and knowledge. I am passionate about what I do and strive to continually improve and grow in my career.Aside from my professional life, I have many hobbies and interests. One of my favorite hobbies is reading. I am an avid reader and enjoy exploring different genres of literature. Reading not only expands my knowledge but also provides me with a great source of relaxation and entertainment.In addition to reading, I am also a passionate traveler. I believe that traveling allows us to broaden our horizons, experience different cultures, and gain a better understanding of the world we live in. I have been fortunate enough to visit several countries and each trip has left a lasting impact on me.Furthermore, I am an active volunteer in my community. I firmly believe in the importance of giving back and making a positive difference in the lives of others. Through volunteering, I have had the opportunity to work with various organizations and contribute to meaningful causes.Lastly, I would like to express my gratitude to all those who have supported me throughout my journey. My family, friends, and mentors have played a significant role in shaping who I am today. Their love, guidance, and encouragement have been invaluable.In conclusion, I am a [Your Occupation/Profession] who is passionate about my work and constantly seeking personal and professional growth. I enjoy reading, traveling, and volunteering in my spare time. I am grateful for the support I have received and look forward to the opportunities that lie ahead.Thank you for your attention!演讲稿二：一般介绍Good morning/afternoon/evening, ladies and gentlemen!First of all, I would like to express my sincere gratitude to all of you for being here today. It is truly an honor to have the opportunity to introduce myself to such a distinguished audience.My name is [Your Name] and I am from [Your Country/City]. I am a [Your Occupation/Profession] by profession and have been working in this field for [Number of Years]. I have always been passionate about [Your Field of Work/Study] and strive to excel in everything I do.Apart from my professional life, I have a wide range of interests and hobbies. One of my greatest passions is [Your Hobby/Interest]. This hobby not only allows me to express my creativity but also provides me with a sense of fulfillment and relaxation. I believe that pursuing our passions is essential for personal growth and happiness.Furthermore, I am a strong believer in the power of education. I am a lifelong learner and constantly seek opportunities to expand my knowledge and skills. I believe that education is the key to unlocking our potential and creating a better future for ourselves and society as a whole.In addition to my personal interests, I am also actively involved in community service. I believe in the importance of giving back and making a positive impact in the lives of others. Through volunteering, I have had the opportunity to work with various organizations and contribute to meaningful causes.I am grateful for the support and guidance I have received throughout my journey. My family, friends, and mentors have been instrumental in shaping who I am today. Their unwavering support and belief in me have been a constant source of motivation and inspiration.In conclusion, I am a [Your Occupation/Profession] who is passionate about my work and constantly strives for personal and professional growth. I enjoy [Your Hobby/Interest], believe in the power of education, and actively engage in community service. I am grateful for the support I have received and look forward to the opportunities that lie ahead.Thank you for your attention!演讲稿三：一般介绍Ladies and gentlemen,Good morning/afternoon/evening! I am delighted to have the opportunity to stand before you today and introduce myself. Myname is [Your Name] and I come from [Your Country/City]. It is a privilege to be able to share a little bit about myself with all of you.I am currently a [Your Occupation/Profession] and have been working in this field for [Number of Years]. I find great satisfaction in my work and am constantly seeking ways to improve and contribute to my profession. I believe that by doing what we love, we can make a meaningful difference in the world.In addition to my professional life, I have a wide range of interests and hobbies. One of my favorite pastimes is [Your Hobby/Interest]. This hobby allows me to relax, recharge, and express my creativity.I believe that having a well-rounded life, with passions outside of work, is essential for personal happiness and fulfillment.Furthermore, I am a firm believer in the power of continuous learning. I am always seeking opportunities to expand my knowledge and skills, both personally and professionally. I believe that learning is a lifelong journey that enriches our lives and enables us to adapt to a rapidly changing world.Apart from my personal interests, I am also deeply committed to giving back to my community. I believe that we all have a responsibility to make a positive impact in the lives of others. Through volunteering, I have had the privilege of working with various charitable organizations and witnessing firsthand the difference we can make when we come together.I would like to express my gratitude to my family, friends, and mentors who have supported me throughout my journey. Their love, guidance, and encouragement have been invaluable and have shaped me into the person I am today.In conclusion, I am a [Your Occupation/Profession] who is passionate about my work and always striving for personal and professional growth. I enjoy [Your Hobby/Interest], believe in the power of continuous learning, and actively engage in community service. I am thankful for the support I have received and eagerly anticipate the opportunities that lie ahead.Thank you for your attention!。
(NEW)刘润清《新编语言学教程》笔记和课后习题(含考研真题)详解
第1章 导 言 1.1 复习笔记 1.2 课后习题详解 1.3 考研真题与典型题详解
第2章 语 音 2.1 复习笔记 2.2 课后习题详解 2.3 考研真题与典型题详解
第3章 形态学 3.1 复习笔记 3.2 课后习题详解 3.3 考研真题与典型题详解
第4章 句 法 4.1 复习笔记 4.2 课后习题详解
III. Scope of linguistics (语言学的研究范畴) 1. Microlinguistics(微观语言学) Phonetics语音学 Phonology音系学 Morphology形态学 Syntax句法学
Semantics语义学 Pragmatics语用学 2. Macrolinguistics (宏观语言学) Sociolinguistics社会语言学 Psycholinguistics心理语言学 Neurolinguistics神经语言学 Stylistics文体学 Discourse analysis语篇分析 Computational linguistics计算语言学 Cognitive linguistics认知语言学 Applied linguistics应用语言学
3. Language is vocal—the primary medium for all languages is sound. 4. Language is used for human communication—it is human-specific, very different from systems of animal communication. 1. 语言是一个系统——其元素非任意排列，而是根据一定规则组合的。 2. 语言是任意的——词与其所指物之间没有内在的联系。 3. 语言是口头的——是所有语言的基本交流形式。 4. 语言是人类用来交流的工具——不同于动物的交流系统。
829-1998_IEEE Standard for Software Test Documentation
IEEE Std 829-1998(Revision ofIEEE Std 829-1983) IEEE Standard for Software Test DocumentationSponsorSoftware Engineering Technical Committeeof theIEEE Computer SocietyApproved 16 September 1998IEEE-SA Standards BoardAbstract: A set of basic software test documents is described. This standard speciÞes the form and content of individual test documents. It does not specify the required set of test documents. Keywords: test case specification, test design specification, test incident report, test item transmit-tal report, test log, test plan, test procedure specification, test summary reportIEEE Standards documents are developed within the IEEE Societies and the Standards Coordinat-ing Committees of the IEEE Standards Association (IEEE-SA) Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessarily members of the Institute. The standards developed within IEEE represent a consensus of the broad expertise on the subject within the Institute as well as those activities outside of IEEE that have expressed an inter-est in participating in the development of the standard.Use of an IEEE Standard is wholly voluntary. The existence of an IEEE Standard does not imply that there are no other ways to produce, test, measure, purchase, market, or provide other goods and services related to the scope of the IEEE Standard. Furthermore, the viewpoint expressed at the time a standard is approved and issued is subject to change brought about through developments in the state of the art and comments received from users of the standard. Every IEEE Standard is sub-jected to review at least every Þve years for revision or reafÞrmation. When a document is more than Þve years old and has not been reafÞrmed, it is reasonable to conclude that its contents, although still of some value, do not wholly reßect the present state of the art. Users are cautioned to check to determine that they have the latest edition of any IEEE Standard.Comments for revision of IEEE Standards are welcome from any interested party, regardless of membership afÞliation with IEEE. Suggestions for changes in documents should be in the form of a proposed change of text, together with appropriate supporting comments.Interpretations: Occasionally questions may arise regarding the meaning of portions of standards as they relate to speciÞc applications. When the need for interpretations is brought to the attention of IEEE, the Institute will initiate action to prepare appropriate responses. Since IEEE Standards rep-resent a consensus of all concerned interests, it is important to ensure that any interpretation has also received the concurrence of a balance of interests. For this reason, IEEE and the members of its societies and Standards Coordinating Committees are not able to provide an instant response to interpretation requests except in those cases where the matter has previously received formal consideration.Comments on standards and requests for interpretations should be addressed to:Secretary, IEEE-SA Standards Board445 Hoes LaneP.O. Box 1331Piscataway, NJ 08855-1331USAAuthorization to photocopy portions of any individual standard for internal or personal use is granted by the Institute of Electrical and Electronics Engineers, Inc., provided that the appropriate fee is paid to Copyright Clearance Center. To arrange for payment of licensing fee, please contact Copyright Clearance Center, Customer Service, 222 Rosewood Drive, Danvers, MA 01923 USA; (978) 750-8400. Permission to photocopy portions of any individual standard for educational class-room use can also be obtained through the Copyright Clearance Center.Introduction(This introduction is not part of IEEE Std 829-1998, IEEE Standard for Software Test Documentation.)PurposeThe purpose of this standard is to describe a set of basic software test documents. A standardized test docu-ment can facilitate communication by providing a common frame of reference (e.g., a customer and a supplier have the same deÞnition for a test plan). The content deÞnition of a standardized test document can serve as a completeness checklist for the associated testing process. A standardized set can also provide a baseline for the evaluation of current test documentation practices. In many organizations, the use of these documents signiÞcantly increases the manageability of testing. Increased manageability results from the greatly increased visibility of each phase of the testing process.This standard speciÞes the form and content of individual test documents. It does not specify the required set of test documents. It is assumed that the required set of test documents will be speciÞed when the standard is applied. Annex B contains an example of such a set speciÞcation.The readers of this standard are referred to Annex C for guidelines for using this standard to meet the requirements of IEEE/EIA 12207.1-1997, IEEE/EIA Guide for Information TechnologyÑSoftware life cycle processesÑLife cycle data.OverviewThe documents outlined in this standard cover test planning, test speciÞcation, and test reporting.The test plan prescribes the scope, approach, resources, and schedule of the testing activities. It identiÞes the items to be tested, the features to be tested, the testing tasks to be performed, the personnel responsible for each task, and the risks associated with the plan.Test speciÞcation is covered by three document types:Ñ A test design speciÞcation reÞnes the test approach and identiÞes the features to be covered by the design and its associated tests. It also identiÞes the test cases and test procedures, if any, required to accomplish the testing and speciÞes the feature pass/fail criteria.Ñ A test case speciÞcation documents the actual values used for input along with the anticipated out-puts. A test case also identiÞes constraints on the test procedures resulting from use of that speciÞc test case. Test cases are separated from test designs to allow for use in more than one design and to allow for reuse in other situations.Ñ A test procedure speciÞcation identiÞes all steps required to operate the system and exercise the speciÞed test cases in order to implement the associated test design. Test procedures are separated from test design speciÞcations as they are intended to be followed step by step and should not have extraneous detail.Test reporting is covered by four document types:Ñ A test item transmittal report identiÞes the test items being transmitted for testing in the event that separate development and test groups are involved or in the event that a formal beginning of test exe-cution is desired.Ñ A test log is used by the test team to record what occurred during test execution.Ñ A test incident report describes any event that occurs during the test execution which requires further investigation.Ñ A test summary report summarizes the testing activities associated with one or more test design spec-iÞcations.Figure 1 shows the relationships of these documents to one another as they are developed and to the testing process they document.Figure 1ÑRelationship of test documents to testing processTerminologyThe words shall, must, and the imperative form identify the mandatory material within this standard. The words should and may identify optional material.AnnexesThe examples found in Annex A are meant to clarify the intent of the document descriptions found in the standard. Some suggestions about implementing and using the standard are in Annex B. Guidelines for compliance with IEEE/EIA 12207.1-1997 are provided in Annex C.AudienceThis standard should be of interest to software users and software procurement personnel; to development,test, and maintenance personnel; to operations and acquisition support managers; to software quality assur-ance personnel and auditors; and to participants in the legal system.ParticipantsThis revision was prepared by the Life Cycle Data Harmonization Working Group of the Software Engineer-ing Standards Committee of the IEEE Computer Society. At the time this standard was approved, the work-ing group consisted of the following members:Leonard L. Tripp, ChairThe following persons were on the balloting committee:Edward ByrnePaul R. CrollPerry DeWeeseRobin FralickMarilyn Ginsberg-FinnerJohn HarauzMark Henley Dennis Lawrence David Maibor Ray Milovanovic James Moore Timothy Niesen Dennis Rilling Terry Rout Richard Schmidt Norman F. Schneidewind David Schultz Basil Sherlund Peter V oldner Ronald WadeSyed AliH. Ronald BerlackRichard E. BiehlSandro BolognaJuris BorzovsAudrey C BrewerKathleen L. BriggsM. Scott BuckMichael CaldwellJames E. CardowJaya R. CarlEnrico A. CarraraLawrence CatchpoleKeith ChanAntonio M. CicuTheo ClarkeSylvain ClermontRosemary ColemanVirgil Lee CooperW. W. Geoff CozensPaul R. CrollPatricia W. DaggettGregory T. Daich Geoffrey Darnton Taz Daughtrey Bostjan K. Derganc Perry R. DeWeese Evelyn S. Dow Carl Einar Dragstedt Charles Droz Sherman Eagles Leo Egan Richard L. Evans William Eventoff Richard E. Fairley John W. Fendrich Jay Forster Kirby Fortenberry Eva Freund Richard C. Fries Roger U. Fujii David Gelperin Adel N. Ghannam Marilyn Ginsberg-Finner John Garth Glynn Julio Gonzalez-Sanz L. M. Gunther David A. Gustafson Jon D. Hagar John Harauz Herbert Hecht Debra Herrmann Umesh P. Hiriyannaiah John W. Horch Jerry Huller Peter L. Hung George Jackelen Frank V . Jorgensen Vladan V . Jovanovic William S. Junk George X. Kambic Ron S. Kenett Judith S. Kerner Robert J. Kierzyk Shaye Koenig Thomas M. Kurihara John B. Lane J. Dennis Lawrence Randal LeavittWhen the IEEE-SA Standards Board approved this standard on 16 September 1998, it had the following membership:Richard J. Holleman, Chair Donald N. Heirman, Vice ChairJudith Gorman, Secretary*Member EmeritusValerie E. ZelentyIEEE Standards Project EditorFang Ching LimWilliam M. LivelyJohn LordStan MageeDavid MaiborHarold MainsRobert A. MartinMike McAndrewPatrick D. McCraySue McGrathJacques MeekelJames Bret MichaelAlan MillerCelia H. ModellJames W. MoorePavol NavratMyrna L. OlsonIndradeb P. PalAlex PolackPeter T. PoonLawrence S. Przybylski Kenneth R. Ptack Ann E. Reedy Annette D. Reilly Terence P. Rout Andrew P. Sage Helmut Sandmayr Stephen R. Schach Hans Schaefer Norman Schneidewind David J. Schultz Lisa A. Selmon Robert W. Shillato David M. Siefert Carl A. Singer Nancy M. Smith Alfred R. Sorkowitz Donald W. Sova Luca Spotorno Julia Stesney Fred J. Strauss Christine Brown Strysik Sandra Swearingen Toru Takeshita Richard H. Thayer Booker Thomas Patricia Trellue Leonard L. Tripp Theodore J. Urbanowicz Glenn D. Venables Andre Villas-Boas Udo V oges Delores Wallace William M. Walsh John W. Walz Camille S. White-Partain Scott A. Whitmire P. A. Wolfgang Paul R. Work Natalie C. Yopconka Janusz Zalewski Geraldine Zimmerman Peter F. ZollSatish K. Aggarwal Clyde R. Camp James T. Carlo Gary R. Engmann Harold E. Epstein Jay Forster*Thomas F. Garrity Ruben D. GarzonJames H. GurneyJim D. IsaakLowell G. JohnsonRobert KennellyE. G. ÒAlÓ KienerJoseph L. KoepÞnger*Stephen R. LambertJim LogothetisDonald C. Loughry L. Bruce McClung Louis-Fran•ois Pau Ronald C. Petersen Gerald H. Peterson John B. Posey Gary S. Robinson Hans E. Weinrich Donald W. ZipseContents1.Scope (1)2.References (2)3.Definitions (2)4.Test plan (3)4.1Purpose (3)4.2Outline (3)5.Test design specification (6)5.1Purpose (6)5.2Outline (6)6.Test case specification (7)6.1Purpose (7)6.2Outline (7)7.Test procedure specification (9)7.1Purpose (9)7.2Outline (9)8.Test item transmittal report (10)8.1Purpose (10)8.2Outline (11)9.Test log (11)9.1Purpose (11)9.2Outline (12)10.Test incident report (13)10.1Purpose (13)10.2Outline (13)11.Test summary report (14)11.1 Purpose (14)11.2 Outline (14)Annex A (informative) Examples (16)Annex B(informative) Implementation and usage guidelines (40)Annex C(informative) Guidelines for compliance with IEEE/EIA 12207.1-1997 (41)IEEE Standard for Software Test Documentation1. ScopeThis standard describes a set of basic test documents that are associated with the dynamic aspects of soft-ware testing (i.e, the execution of procedures and code). The standard deÞnes the purpose, outline, and content of each basic document. While the documents described in the standard focus on dynamic testing, several of them may be applicable to other testing activities (e.g., the test plan and test incident report may be used for design and code reviews).This standard may be applied to commercial, scientiÞc, or military software that runs on any digital computer. Applicability is not restricted by the size, complexity, or criticality of the software. However, the standard does not specify any class of software to which it must be applied. The standard addresses the documentation of both initial development testing and the testing of subsequent software releases. For a particular software release, it may be applied to all phases of testing from module testing through user acceptance. However, since all of the basic test documents may not be useful in each test phase, the particu-lar documents to be used in a phase are not speciÞed. Each organization using the standard will need to spec-ify the classes of software to which it applies and the speciÞc documents required for a particular test phase. The standard does not call for speciÞc testing methodologies, approaches, techniques, facilities, or tools, and does not specify the documentation of their use. Additional test documentation may be required (e.g., code inspection checklists and reports). The standard also does not imply or impose speciÞc methodologies for documentation control, conÞguration management, or quality assurance. Additional documentation (e.g., a quality assurance plan) may be needed depending on the particular methodologies used.Within each standard document, the content of each section (i.e., the text that covers the designated topics) may be tailored to the particular application and the particular testing phase. In addition to tailoring content, additional documents may be added to the basic set, additional sections may be added to any document, and additional content may be added to any section. It may be useful to organize some of the sections into subsections. Some or all of the contents of a section may be contained in another document which is then referenced. Each organization using the standard should specify additional content requirements and conventions in order to reßect their own particular methodologies, approaches, facilities, and tools for test-ing, documentation control, conÞguration management, and quality assurance.This standard applies to documentation on electronic media as well as paper. Paper must be used for docu-ments requiring approval signatures, unless the electronic documentation system has a secure approval anno-tation mechanism and that mechanism is used.IEEEStd 829-1998IEEE ST ANDARD FOR 2. ReferencesThis standard shall be used in conjunction with the following publication.IEEE Std 610.12-1990, IEEE Standard Glossary of Software Engineering Terminology.13. DeÞnitionsThis clause contains key terms as they are used in this standard.3.1 design level: The design decomposition of the software item (e.g., system, subsystem, program, or module).3.2 pass/fail criteria: Decision rules used to determine whether a software item or a software feature passes or fails a test.3.3 software feature: A distinguishing characteristic of a software item (e.g., performance, portability, or functionality).3.4 software item: Source code, object code, job control code, control data, or a collection of these items.3.5 test:(A) A set of one or more test cases, or (B) A set of one or more test procedures, or (C) A set of one or more test cases and procedures.3.6 test case speciÞcation: A document specifying inputs, predicted results, and a set of execution condi-tions for a test item.3.7 test design speciÞcation: A document specifying the details of the test approach for a software feature or combination of software features and identifying the associated tests.3.8 test incident report: A document reporting on any event that occurs during the testing process which requires investigation.3.9 testing: The process of analyzing a software item to detect the differences between existing and required conditions (that is, bugs) and to evaluate the features of the software item.3.10 test item: A software item which is an object of testing.3.11 test item transmittal report: A document identifying test items. It contains current status and location information.3.12 test log: A chronological record of relevant details about the execution of tests.3.13 test plan: A document describing the scope, approach, resources, and schedule of intended testing activities. It identiÞes test items, the features to be tested, the testing tasks, who will do each task, and any risks requiring contingency planning.3.14 test procedure speciÞcation: A document specifying a sequence of actions for the execution of a test.3.15 test summary report: A document summarizing testing activities and results. It also contains an evalu-ation of the corresponding test items.1IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331, USA (/).IEEE SOFTWARE TEST DOCUMENT A TION Std 829-1998 4. Test plan4.1 PurposeTo prescribe the scope, approach, resources, and schedule of the testing activities. To identify the items being tested, the features to be tested, the testing tasks to be performed, the personnel responsible for each task, and the risks associated with this plan.4.2 OutlineA test plan shall have the following structure:a)Test plan identiÞer;b)Introduction;c)Test items;d)Features to be tested;e)Features not to be tested;f)Approach;g)Item pass/fail criteria;h)Suspension criteria and resumption requirements;i)Test deliverables;j)Testing tasks;k)Environmental needs;l)Responsibilities;m)StafÞng and training needs;n)Schedule;o)Risks and contingencies;p)Approvals.The sections shall be ordered in the speciÞed sequence. Additional sections may be included immediately prior to Approvals. If some or all of the content of a section is in another document, then a reference to that material may be listed in place of the corresponding content. The referenced material must be attached to the test plan or available to users of the plan.Details on the content of each section are contained in the following subclauses.4.2.1 Test plan identiÞerSpecify the unique identiÞer assigned to this test plan.4.2.2 IntroductionSummarize the software items and software features to be tested. The need for each item and its history may be included.References to the following documents, when they exist, are required in the highest level test plan:a)Project authorization;b)Project plan;c)Quality assurance plan;d)ConÞguration management plan;e)Relevant policies;f)Relevant standards.IEEEStd 829-1998IEEE ST ANDARD FOR In multilevel test plans, each lower-level plan must reference the next higher-level plan.4.2.3 Test itemsIdentify the test items including their version/revision level. Also specify characteristics of their transmittal media that impact hardware requirements or indicate the need for logical or physical transformations before testing can begin (e.g., programs must be transferred from tape to disk).Supply references to the following test item documentation, if it exists:a)Requirements speciÞcation;b)Design speciÞcation;c)Users guide;d)Operations guide;e)Installation guide.Reference any incident reports relating to the test items.Items that are to be speciÞcally excluded from testing may be identiÞed.4.2.4 Features to be testedIdentify all software features and combinations of software features to be tested. Identify the test design speciÞcation associated with each feature and each combination of features.4.2.5 Features not to be testedIdentify all features and signiÞcant combinations of features that will not be tested and the reasons.4.2.6 ApproachDescribe the overall approach to testing. For each major group of features or feature combinations, specify the approach that will ensure that these feature groups are adequately tested. Specify the major activities, techniques, and tools that are used to test the designated groups of features.The approach should be described in sufÞcient detail to permit identiÞcation of the major testing tasks and estimation of the time required to do each one.Specify the minimum degree of comprehensiveness desired. Identify the techniques that will be used to judge the comprehensiveness of the testing effort (e.g., determining which statements have been executed at least once). Specify any additional completion criteria (e.g., error frequency). The techniques to be used to trace requirements should be speciÞed.Identify signiÞcant constraints on testing such as test item availability, testing resource availability, and deadlines.4.2.7 Item pass/fail criteriaSpecify the criteria to be used to determine whether each test item has passed or failed testing.4.2.8 Suspension criteria and resumption requirementsSpecify the criteria used to suspend all or a portion of the testing activity on the test items associated with this plan. Specify the testing activities that must be repeated, when testing is resumed.IEEE SOFTWARE TEST DOCUMENT A TION Std 829-1998 4.2.9 Test deliverablesIdentify the deliverable documents. The following documents should be included:a)Test plan;b)Test design speciÞcations;c)Test case speciÞcations;d)Test procedure speciÞcations;e)Test item transmittal reports;f)Test logs;g)Test incident reports;h)Test summary reports.Test input data and test output data should be identiÞed as deliverables.Test tools (e.g., module drivers and stubs) may also be included.4.2.10 Testing tasksIdentify the set of tasks necessary to prepare for and perform testing. Identify all intertask dependencies and any special skills required.4.2.11 Environmental needsSpecify both the necessary and desired properties of the test environment. This speciÞcation should contain the physical characteristics of the facilities including the hardware, the communications and system soft-ware, the mode of usage (e.g., stand-alone), and any other software or supplies needed to support the test. Also specify the level of security that must be provided for the test facilities, system software, and propri-etary components such as software, data, and hardware.Identify special test tools needed. Identify any other testing needs (e.g., publications or ofÞce space). Iden-tify the source for all needs that are not currently available to the test group.4.2.12 ResponsibilitiesIdentify the groups responsible for managing, designing, preparing, executing, witnessing, checking, and resolving. In addition, identify the groups responsible for providing the test items identiÞed in 4.2.3 and the environmental needs identiÞed in 4.2.11.These groups may include the developers, testers, operations staff, user representatives, technical support staff, data administration staff, and quality support staff.4.2.13 StafÞng and training needsSpecify test stafÞng needs by skill level. Identify training options for providing necessary skills.4.2.14 ScheduleInclude test milestones identiÞed in the software project schedule as well as all item transmittal events.DeÞne any additional test milestones needed. Estimate the time required to do each testing task. Specify the schedule for each testing task and test milestone. For each testing resource (i.e., facilities, tools, and staff), specify its periods of use.IEEEStd 829-1998IEEE ST ANDARD FOR 4.2.15 Risks and contingenciesIdentify the high-risk assumptions of the test plan. Specify contingency plans for each (e.g., delayed delivery of test items might require increased night shift scheduling to meet the delivery date).4.2.16 ApprovalsSpecify the names and titles of all persons who must approve this plan. Provide space for the signatures and dates.5. Test design speciÞcation5.1 PurposeTo specify reÞnements of the test approach and to identify the features to be tested by this design and its associated tests.5.2 OutlineA test design speciÞcation shall have the following structure:a)Test design speciÞcation identiÞer;b)Features to be tested;c)Approach reÞnements;d)Test identiÞcation;e)Feature pass/fail criteria.The sections shall be ordered in the speciÞed sequence. Additional sections may be included at the end. If some or all of the content of a section is in another document, then a reference to that material may be listed in place of the corresponding content. The referenced material must be attached to the test design speciÞca-tion or available to users of the design speciÞcation.Details on the content of each section are contained in the following subclauses.5.2.1 Test design speciÞcation identiÞerSpecify the unique identiÞer assigned to this test design speciÞcation. Supply a reference to the associated test plan, if it exists.5.2.2 Features to be testedIdentify the test items and describe the features and combinations of features that are the object of this design speciÞcation. Other features may be exercised, but need not be identiÞed.For each feature or feature combination, a reference to its associated requirements in the item requirement speciÞcation or design description should be included.5.2.3 Approach reÞnementsSpecify reÞnements to the approach described in the test plan. Include speciÞc test techniques to be used. The method of analyzing test results should be identiÞed (e.g., comparator programs or visual inspection).IEEE SOFTWARE TEST DOCUMENT A TION Std 829-1998 Specify the results of any analysis that provides a rationale for test case selection. For example, one might specify conditions that permit a determination of error tolerance (e.g., those conditions that distinguish valid inputs from invalid inputs).Summarize the common attributes of any test cases. This may include input constraints that must be true for every input in the set of associated test cases, any shared environmental needs, any shared special procedural requirements, and any shared case dependencies.5.2.4 Test identiÞcationList the identiÞer and a brief description of each test case associated with this design. A particular test case may be identiÞed in more than one test design speciÞcation. List the identiÞer and a brief description of each procedure associated with this test design speciÞcation.5.2.5 Feature pass/fail criteriaSpecify the criteria to be used to determine whether the feature or feature combination has passed or failed.6. Test case speciÞcation6.1 PurposeTo deÞne a test case identiÞed by a test design speciÞcation.6.2 OutlineA test case speciÞcation shall have the following structure:a)Test case speciÞcation identiÞer;b)Test items;c)Input speciÞcations;d)Output speciÞcations;e)Environmental needs;f)Special procedural requirements;g)Intercase dependencies.The sections shall be ordered in the speciÞed sequence. Additional sections may be included at the end. If some or all of the content of a section is in another document, then a reference to that material may be listed in place of the corresponding content. The referenced material must be attached to the test case speciÞcation or available to users of the case speciÞcation.Since a test case may be referenced by several test design speciÞcations used by different groups over a long time period, enough speciÞc information must be included in the test case speciÞcation to permit reuse. Details on the content of each section are contained in the following subclauses.6.2.1 Test case speciÞcation identiÞerSpecify the unique identiÞer assigned to this test case speciÞcation.。
相对论史话 英语介绍
相对论史话英语介绍Relativity: A Historical Overview.Relativity is a fundamental concept in modern physics, proposed by Albert Einstein in 1905. It revolutionized our understanding of space, time, and the universe as a whole. There are two main components of relativity: the Special Theory of Relativity and the General Theory of Relativity.The Special Theory of Relativity asserts that space and time are interconnected and relative, rather than absolute and fixed. Einstein introduced the idea that the speed of light is constant in all inertial reference frames, regardless of the observer's state of motion. This led to the famous "principle of relativity," which states that the laws of physics are the same in all inertial reference frames.One of the consequences of special relativity is the relativity of time. This principle states that the passageof time is not absolute; it can vary depending on the observer's reference frame. For example, if two events occur at different points in space, the time interval between these events will be different for observers in different reference frames.Another consequence of special relativity is the relativity of space. This principle suggests that the measurements of space can vary depending on the observer's motion. For instance, two observers moving relative to each other may measure different distances between the same two points in space.The Special Theory of Relativity also gave rise to the famous equation E=mc^2, known as the mass-energy equivalence. This equation states that mass and energy are equivalent and can be converted into each other. This equivalence has profound implications in physics, including the possibility of nuclear energy production and the annihilation of matter.The General Theory of Relativity, published in 1915, isan extension of the Special Theory. It incorporates the idea of gravity as a curvature of spacetime. Einstein proposed that matter and energy curve spacetime, creating a gravitational field that affects the motion of other matter and energy. This theory explained many phenomena that had previously been unexplained, such as the precession of the perihelion of Mercury.The General Theory of Relativity also gave rise to the concept of black holes, regions of spacetime where gravity is so strong that nothing can escape, including light. Black holes are predicted to form when a massive star collapses under its own weight.Relativity has had a profound impact on our understanding of the universe. It has revolutionized our view of space and time, showing that they are not absolute but relative to the observer's reference frame. It has also provided a new understanding of gravity and the curvature of spacetime. The predictions of relativity have been confirmed through numerous experiments and observations, making it one of the most well-tested and accepted theoriesin physics.In conclusion, relativity is a fundamental concept in modern physics that has revolutionized our understanding of space, time, and the universe. The Special Theory of Relativity introduced the idea that space and time are relative and interconnected, while the General Theory of Relativity extended this idea to include the curvature of spacetime and the phenomenon of gravity. The predictions of relativity have been confirmed through numerous experiments and observations, making it one of the most important and well-established theories in physics.。
英语演讲开场白范文（通用15篇）
英语演讲开场白范文（通用15篇）英语演讲范文篇1尊敬的评委，尊贵的来宾，女士们，先生们，大家晚上好!能够站在这里进行演说，我感到十分荣幸。
今天我将和大家一起分享……honorable judges,distinguished guests,ladies and gentlemen,good evening!i feel really honored to stand here and make a speech.today i"m going to look together with you into this question:……good morning everybody!it's my honor to speak here,and i am very glad to share my topic with you. then today i'd like to talk something about.....(大家早上好!能在这里做此次演讲我十分荣幸，也很高兴能跟大家一起分享我的主题，今天我想演讲的是......)good evening, ladies and gentlemen, and welcome to the english speaking competition for grade . (掌声~~~) first of all, please allow me to introduce myself, your host for today. i’m sammy from cla6, grade .(译文：女士们，先生们，大家晚上好!欢迎来到05级英语演讲比赛的现常首先，请允许我来个。
我是今晚的主持人—来自05级6班的典典。
)there are all together 26 contestants to compete in today’s english speaking competition, all from grade . and this competition will be mediated by a panel of five judges. also on the panel are “question masters” who will be responsible for raising questions of today’s contestants. now, i have the great privilege of presenting today’s judges.(译文：角逐今晚比赛的有26名选手,他们均来自外院05级的同学。
初中趣味英语基础知识抢答100题
初中趣味英语基础知识抢答100题1. What is the capital of Australia?The capital of Australia is Canberra.2. Who wrote the famous play, Romeo and Juliet? Romeo and Juliet was written by William Shakespeare.3. How many planets are there in our solar system? There are eight planets in our solar system.4. What is the largest ocean in the world?The Pacific Ocean is the largest ocean in the world.5. Who painted the Mona Lisa?The Mona Lisa was painted by Leonardo da Vinci.6. What is the chemical symbol for gold?The chemical symbol for gold is Au.7. What is the largest organ in the human body?The skin is the largest organ in the human body.8. Who is the author of the Harry Potter series?J.K. Rowling is the author of the Harry Potter series. 9. What is the tallest mountain in the world?Mount Everest is the tallest mountain in the world.10. Which country is known as the land of the rising sun? Japan is known as the land of the rising sun.11. Who invented the telephone?Alexander Graham Bell invented the telephone.12. What is the largest desert in the world?The Sahara Desert is the largest desert in the world. 13. What is the chemical symbol for oxygen?The chemical symbol for oxygen is O.14. Who was the first person to walk on the moon?Neil Armstrong was the first person to walk on the moon.15. What is the longest river in the world?The Nile River is the longest river in the world.16. What is the national bird of the United States?The national bird of the United States is the Bald Eagle.17. Which country is famous for the Taj Mahal?India is famous for the Taj Mahal.18. Who wrote the famous novel, To Kill a Mockingbird?To Kill a Mockingbird was written by Harper Lee.19. What is the chemical symbol for water?The chemical symbol for water is H2O.20. Who painted the famous artwork, The Starry Night? The Starry Night was painted by Vincent van Gogh.21. What is the largest species of penguin?The Emperor Penguin is the largest species of penguin.22. Who was the first president of the United States?George Washington was the first president of the United States.23. What is the longest bone in the human body?The femur is the longest bone in the human body.24. Who wrote the famous novel, Pride and Prejudice?Pride and Prejudice was written by Jane Austen.25. What is the chemical symbol for carbon?The chemical symbol for carbon is C.26. Who is the famous scientist who proposed the theory of relativity?Albert Einstein proposed the theory of relativity.27. What is the largest continent in the world?Asia is the largest continent in the world.28. Who painted the famous artwork, The Last Supper? The Last Supper was painted by Leonardo da Vinci. 29. What is the national flower of Japan?The national flower of Japan is the cherry blossom.30. Who invented the lightbulb?Thomas Edison invented the lightbulb.31. What is the largest mammal in the world?The blue whale is the largest mammal in the world.32. Who wrote the famous novel, The Great Gatsby? The Great Gatsby was written by F. Scott Fitzgerald.33. What is the chemical symbol for iron?The chemical symbol for iron is Fe.34. Who is the famous scientist who developed the theory of evolution?Charles Darwin developed the theory of evolution.35. What is the largest bird in the world?The ostrich is the largest bird in the world.36. Who painted the famous artwork, The Scream?The Scream was painted by Edvard Munch.37. What is the national flower of the United States?The national flower of the United States is the rose.38. Who invented the theory of gravity?Isaac Newton invented the theory of gravity.39. What is the largest waterfall in the world?Angel Falls is the largest waterfall in the world.40. Who wrote the famous novel, Moby-Dick?Moby-Dick was written by Herman Melville.41. What is the chemical symbol for hydrogen?The chemical symbol for hydrogen is H.42. Who is the famous scientist who discovered penicillin? Alexander Fleming discovered penicillin.43. What is the largest big cat in the world?The tiger is the largest big cat in the world.44. Who painted the famous artwork, Guernica?Guernica was painted by Pablo Picasso.45. What is the national flower of England?The national flower of England is the rose.46. Who invented the theory of general relativity?Albert Einstein invented the theory of general relativity.47. What is the largest fish in the world?The whale shark is the largest fish in the world.48. Who wrote the famous novel, 1984?1984 was written by George Orwell.49. What is the chemical symbol for silver?The chemical symbol for silver is Ag.50. Who is the famous scientist who developed the laws of motion?Isaac Newton developed the laws of motion.51. What is the largest reptile in the world?The saltwater crocodile is the largest reptile in the world.52. Who painted the famous artwork, The Persistence of Memory?The Persistence of Memory was painted by Salvador Dalí.53. What is the national flower of France?The national flower of France is the iris.54. Who invented the theory of quantum mechanics?Max Planck and Albert Einstein contributed to the development of the theory of quantum mechanics.55. What is the largest cat species in the world?The Siberian tiger is the largest cat species in the world.56. Who wrote the famous novel, The Catcher in the Rye?The Catcher in the Rye was written by J.D. Salinger.57. What is the chemical symbol for calcium?The chemical symbol for calcium is Ca.58. Who is the famous scientist who discovered the theory of relativity?Albert Einstein formulated the theory of relativity.59. What is the largest amphibian in the world?The Chinese giant salamander is the largest amphibian in the world.60. Who painted the famous artwork, The Birth of Venus?The Birth of Venus was painted by Sandro Botticelli.61. What is the national flower of China?The national flower of China is the peony.62. Who invented the theory of special relativity?Albert Einstein formulated the theory of special relativity.63. What is the largest land-dwelling arthropod in the world?The coconut crab is the largest land-dwelling arthropod in the world.64. Who wrote the famous novel, Animal Farm?Animal Farm was written by George Orwell.65. What is the chemical symbol for helium?The chemical symbol for helium is He.66. Who is the famous scientist who discovered the lawsof motion?Sir Isaac Newton discovered the laws of motion.67. What is the largest butterfly species in the world?The Queen Alexandra's birdwing is the largest butterfly species in the world.68. Who painted the famous artwork, Girl with a Pearl Earring?Girl with a Pearl Earring was painted by Johannes Vermeer.69. What is the national flower of Germany?The national flower of Germany is the cornflower.70. Who invented the theory of general relativity?Albert Einstein developed the theory of general relativity.71. What is the largest living reptile in the world?The saltwater crocodile is the largest living reptile in the world.72. Who wrote the famous novel, The Lord of the Rings?The Lord of the Rings was written by J.R.R. Tolkien.73. What is the chemical symbol for sodium?The chemical symbol for sodium is Na.74. Who is the famous scientist who developed the theory of evolution by natural selection?Charles Darwin is the famous scientist who developed the theory of evolution by natural selection.75. What is the largest bird of prey in the world?The Andean condor is the largest bird of prey in the world.76. Who painted the famous artwork, The Night Watch?The Night Watch was painted by Rembrandt.77. What is the national flower of Italy?The national flower of Italy is the lily.78. Who invented the theory of quantum mechanics?Max Planck and Albert Einstein played key roles in the development of the theory of quantum mechanics.79. What is the largest species of bear in the world?The polar bear is the largest species of bear in the world.80. Who wrote the famous novel, The Hobbit?The Hobbit was written by J.R.R. Tolkien.81. What is the chemical symbol for potassium?The chemical symbol for potassium is K.82. Who is the famous scientist who discovered the concept of gravity?Sir Isaac Newton discovered the concept of gravity.83. What is the largest land animal in the world?The African elephant is the largest land animal in the world.84. Who painted the famous artwork, The Creation of Adam?The Creation of Adam was painted by Michelangelo.85. What is the national flower of Russia?The national flower of Russia is the chamomile.86. Who invented the theory of special relativity?Albert Einstein formulated the theory of special relativity.87. What is the largest snake species in the world?The reticulated python is the largest snake species in the world.88. Who wrote the famous novel, The Chronicles of Narnia?The Chronicles of Narnia was written by C.S. Lewis.89. What is the chemical symbol for nitrogen?The chemical symbol for nitrogen is N.90. Who is the famous scientist who discovered the laws of motion and gravity?Sir Isaac Newton discovered the laws of motion and gravity.91. What is the largest rodent in the world?The capybara is the largest rodent in the world.92. Who painted the famous artwork, The Starry Night Over the Rhône?The Starry Night Over the Rhône was painted by Vincent van Gogh.93. What is the national flower of Spain?The national flower of Spain is the carnation.94. Who invented the theory of relativity?Albert Einstein is credited with formulating the theory of relativity.95. What is the largest land-dwelling arachnid in the world?The Goliath birdeater spider is the largest land-dwelling arachnid in the world.96. Who wrote the famous novel, War and Peace?War and Peace was written by Leo Tolstoy.97. What is the chemical symbol for phosphorus?The chemical symbol for phosphorus is P.98. Who is the famous scientist who proposed the laws of motion?Sir Isaac Newton proposed the laws of motion.99. What is the largest fish species in the world?The whale shark is the largest fish species in the world.100. Who painted the famous artwork, The Creation of the Sun, Moon and Planets?The Creation of the Sun, Moon and Planets was painted by Michelangelo.。
theory of relativity(相对论)
2013-9-13
Great ahievements of Albert Einstein
• In 1922, Einstein was awarded the 1921 Nobel Prize in Physics • In 1936, Einstein was awarded the Franklin Institute 's Franklin Medal • In 1999 Albert Einstein was named the Person of the Century
2013-9-13
• On Einstein introduced these new concept, most physicists, including relativity transformation between the founder of lorentz, feel hard to accept.
2013-9-13
• The old way of thinking of the obstacle, make this a new physical theory until generation only after for broad physicists are familiar with
2013-9-13
• The brief introduction of Albert Einstein • Great ahievements of Albert Einstein • The best well known achievement:Specia l relativity and General relativity • The members of our team
Introduction to RS(推荐系统概论)
Data & Knowledge Sources
In any case,as a general classification, data used by RSs refers to three kinds of objects: items,users, and transactions, i.e. relations between users and items.
Aggregating preferences, criteria or similarities.
RS Function
E-service providers introduce RSs:
Increase the number of items sold.
Sell more diverse items.
Increase the user satisfaction. Increase user fidelity. Better understand what the user wants.
the goal of the recommendation; as mentioned previously, the data that is available. The authors propose to build a model of the environment based on three dimensions: system users; the characteristics of the data; and the overall application.
RS and Human-Computer Interaction
From the users perspective:
topic 5 verbal communication
Look at two more examples that happened during the Second World War: During World War II, the British government asked the United States for thousands of bushels of ―corn‖ to feed liberated populations. The British really wanted wheat, and this language blunder cost a few million dollars to repair. The British term for corn is ―maize‖ or ―Indian corn‖.
王昌龄
寒雨连江夜入吴， 平明送客楚山孤。 洛阳亲友如相问， 一片冰心在玉壶。 * An sinologist’s translation: Put a piece of icy heart in the vase of jade.
PowerPoint slides by GAO Yali
15
One word or idiom may have a different meaning and implication even in another culture that uses the same language.
PowerPoint slides by GAO Yali
6
Translation
a. 林黛玉的母亲是贾宝玉的姑母，贾宝玉的母亲是林黛玉的舅 母，又是薛宝钗的姨母。 b. Three cousins of the French Presidents were also to receive diamonds.
universe(宇宙简介)课件
the black hole(黑洞)
Definition OF THE BLACK HOLE
A black hole is a region of spacetime from which gravity prevents anything, including light, from escaping.The theory of general relativity(广义相对论) predicts that a sufficiently compact（紧凑的） mass will deform（使畸 形） spacetime to form a black hole.
质量变化不大，但它的亮度、温度和颜色是变化的。除密近双星外， 恒星在它的各个演化阶段，质量基本不变。
恒星的亮度一般称为光度(恒星的发光能力)。在天文学上，用星 等表示，星等越高，亮度越低。(二等星比一等星光度暗10倍，比
一等星亮10倍的就是0等星，依此类推。)
1. 主序星阶段
恒星质量小，亮度低。恒星质量大，亮度高。
【星系、行星等的发展，暗能量加速了宇宙的扩张】
A relatively recent event in cosmological terms, dark energy has caused the expansion of the universe to accelerate. Throughout this entire cosmological evolution, the universe has been expanding, as outlined by the theory of general relativity. It accelerated very quickly during the inflationary period, then slowed down significantly and seems to have expanded relatively consistently, but recent results have indicated that a strange new substance, dark energy, is actually speeding up the acceleration.
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Introduction to General Relativity – Handout
Lin “Jimmie” Haipeng, Wang “Richie” Yunchong
2013.11.13
What is General Relativity?
…the geometric theory of gravitation published by Albert Einstein in 1916 and the current description of gravitation in modern physics.
Geometric means that the presence of mass “curves” spacetime like a trampoline and results in gravity.
Why do we need it?
War of Theories:
1905: Albert Einstein published his theory of special relativity reconciling Newton's laws of motion with electrodynamics.
Special relativity changed physics’ basic frameworks like “Space” and “Time”.
Quick Review of Special Relativity
-Speed of Light does not change, anywhere, any way.
o Time and Space are not absolute.
-There is no absolute “fast” or “slow” or “at the same time”.
o All rules of physics are the same in any inertial reference frame.
o All inertial reference frames are equal. (You can’t distinguish between any one)
Problems: VS Classical Physics
- Time and Space are no longer absolute
^^ This resulted in a new framework for Physics. Existing theories like Newton’s Gravity Theory no longer worked.
(Since mass changes, time and space are no longer absolute, etc.)
Several physicists, including Einstein, searched for a theory that would reconcile Newton's law of gravity and special relativity.
Newton’s Gravitational Model is failing
•Time and space are no longer absolute, mass isn’t either
•Half of what Newton’s Gravitational Model is using is failing
•Astrophysics says it doesn’t work out
•Light is deflecting? Time is passing differently due to Gravity?
•Newton isn’t saying it all
With that, let’s follow the steps of Einstein for a basic understanding of GR
1 Equivalence Principle
Special Relativity: You can’t distinguish between inertial reference frames
General Relativity: You can't distinguish between ANY reference frames.
“Roughly speaking, the principle states that a person in a free-falling elevator cannot tell that they are in free fall. Every experiment in such a free-falling environment has the same results as it would for an observer at rest or moving uniformly in deep space, far from all sources of gravity.”
2 Accelerating Reference Frames
You experi ence acceleration (“Gravity”) in accelerating reference frames
Such an additional force due to non-uniform relative motion of two reference frames is called a pseudo-force.
3 Gravity “acceleration” also causes time to go slower.
Imagine a disk spinning. On the outer part, v is larger (v=wR) so time is slower there. Acceleration is larger, and according to equivalence principles – its gravity, so gravity causes slower time too.
Imagine rays of light.
4 Curvature of Space results in Gravity
Applications & Effects
Namely Astrophysics.
(Richie you go, one two)
References
Giancoli, Douglas C. Physics for Scientists and Engineers. Addison-Wesley, 2008. Book.
Iro, Harald. A Modern Approach to Classical Mechanics. World Scientific, 2002. Book. Xihua, Zhong and Chen Ximou. Modern Physics. Beijing: Peking University Press, 2011. Book.。