X. ОБЩЕЕ ПОВТОРЕНИЕ
1. Повторение страдательного залога и неличных форм глагола
Упражнение
Переведите следующие предложения:
- Evaporation is known to go on more rapidly the warmer
and drier the surrounding air is. - The amount of polonium to be obtained from a uranium
mineral can be simply calculated. - Gold, the least active metal, is slowly attacked by fused
nitrates and alkali metals, forming aurates, e. g. KAuO2. - Hydrogen is far more volatile than oxygen because of
its having a much smaller specific weight. - We may suppose the alpha particles within the nucleus
to be in motion.
- The speed of light being extremely great, we cannot
measure it by ordinary means. - The experimental work was done on alkali metal film
reported to be one atom thick. - The equivalent weight of radium has been determined
and found to be 113. - Except where otherwise expressly stated, the foregoing
values are given in the centimeter — gram — second system
of units.
- The photoelectrons do not, in general, all succeed in
reaching the anode.- To produce a precipitate we must meet two conditions.
- There is believed to be three distinct oxides of iodine,
their formulae being J2O4, J4O5and JO4- Increased temperature makes a gas expand.
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- The potential barrier is too high for electrons to go
through. - The alkali metals are remarkable for being so light
as to float on water. - Many volumetric determinations depend upon the
oxidation or reduction of the substance to be determined.
17. The isolation of radium followed by many important investigations made on other previously unknown elements proved to be of greatest importance.
- Water being denser than air, rays are refracted towards
the perpendicular. - We may assume the electrons in an atom to revolve
about the nucleus with sufficient velocities to keep them
from being drawn into the nucleus by the attraction of the
positive charge of the nucleus. - Unless otherwise specified, the charts and tables are
for a perfect gas with a ratio of specific heats(k)of 1.4.
- The reason for having the iron in thin laminations
rather than in a solid chunk is to prevent induced currents
being set up in the iron itself, due to the changing flux
through it. - In elaborating his wave theory Fresnel — to repeat
my earlier observation — had made use of the idea of an
elastic ether of such kind as to be able to transmit only
transverse vibrations.
- Another theory assumes heated gases from the interior
bursting through the crust of the Moon as great bubles. - The compounds potassium perchloride and potassium
permanganate are alike in solubility and crystalline form, and
in being strong oxidizing agents.
2. Повторение страдательного залога,
неличных форм глагола и сослагательного наклонения
Упражнение
Переведитеследующиепредложения:
1. Under the conditions described the reaction would proceed only with difficulty.
2. The electrons were looked upon as being merely minute corpuscles.
3. Let me now explain the way in which a wave is to be imagined.
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- Joule determined the mechanical equivalent of heat to
equal 4.189J/cal. - Were the intensity of all the beams alike, we should
get an opposite result.
6. Each of these procedures has been followed in a few researches.
- If there were no air, the stone and the piece of paper
would fall together. - Johnson has found the effect to be much greater at
higher than at lower altitudes. - All these elements are radioactive, their atoms being
unstable and undergoing spontaneous disintegration.
- The amount of scattering to be expected on the basis
of the formula given above was computed by Einstein. - In particular the author would like to thank L. Apker
for many valuable suggestions. - Work is the result of energy, the latter usually being
defined as capacity for doing work.
13. With respect to size several stars have been found to be many million times the size of the sun.
14. The heating elements can be easily exchanged, should the need arise.
15.The reader is asked to overlook a slight degree of repetitions inevitable in such a book as this.
16. He was the first to determine the exact weight proportions of the components of water.
17. Once formed, bubbles rise because of the vapour being less dense than the liquid in which it is suspended. 18. Were the Earth stationary, the movements of the atmosphere would be controlled almost entirely by temperature differences.
- Other conditions being equal, the temperature remains
the same. - It seems reasonable that the relations found to hold
so well for these films should be true in general.- The gas to be tested is enclosed in a long glass tube.
- The work of Rutherfordfollowed by great research
work of many other scientists is known to every physicist. - Simple substances consist of atoms, each substance
having its own special kind of atom.
24.Electrons can be made to travel at very high speeds.
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- The question is how closely these data represent the
results likely to be obtained in practice. - Special honour belongs to Thomson in having first
formulated a theory to connect these matters as early as 1904.
27. See that the various parts of the electrometer be
connected so as to have definite relative potentials.
28. The relationship that should exist between observations and their interpretation is one that has not always been clearly defined.
29. There is every reason to believe that if one could
obtain an absolutely pure gas, an ion in this gas would have
a unique mobility.
30. For difraction patterns to show themselves, it is
necessary that the width of the slit employed should be of
the order of magnitude of the wavelength of the light.
31. If the air molecules were stationary we should expect
the smoke particles to remain stationary also.
32. A mere list of the numerous applications which have been proposed and written about would provide material for a full chapter.
33. To shorten the experiment, it is suggested that only logarithmic plots for each point be made and the approximate space potentials be determined.
34. Upon classical theory the frequency of emitted
radiation would be expected to be equal to the orbital
frequency of revolution, the conception here introduced being
quite different.
35. With the Earth gradually solidifying from a fluid
condition, the heavier substances would be expected to sink
toward the center, while the lighter would tend to float upon
the surface.
3. Повторение страдательного залога,
неличных форм глагола,сослагательного наклонения и эмфазы
УпражнениеПереведитеследующиепредложения:
I
1. The figures which are given are the times for half of the substance to decay.
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- The simplest colouring atom to consider is the cobalt
ion. - It was not until the 19th century that heat was proved
to be a form of energy. - Some gaseous reacions are not at all influenced by
change in pressure. - It is sometimes difficult to predict what sort of material
is likely to prove suitable for the purpose in mind. - It is the purpose of the chapter to discuss the ionization
and expansion chamber.
7. It is only the water that appears to be decomposed.
8. This procedure is followed in all methods of positive
ray analysis.
9. If the molecules of a gas are widely separated they
must be in motion. Otherwise they would settle out.
- The property of hindering the flow of electricity is
called electrical resistance than the shorter one.- Never has a better oscillator been designed.
- Unfortunately, this idea, attractive as it is by its very
simplicity, appears incapable of being sustained.- Valves prevent gases from reaching high pressure.
- Wax is not a crystal. Nor is glass crystalline.
- It is with the cyclotron that this book is concerned.
- These relations are found to follow certain perfectly
definite rules.- The electron acted on by the field receives acceleration,
- These experiments enable comparison to be made of
the effect of individual ions. - The chemist wants the reaction to go as nearly to
completion as possible. - The circles on Figure 7 indicate the incorrect potentials
which would have been assigned using the old single probe
method.
- There seems to be no room for many additional
positive ions coming from the negative glow. - It was not until Roentgen discovered his mysterious
rays that many diseases could be easily diagnosed. - That normal gas does conduct somewhat was proved
simultaneously by Wilson and Geitel. - The efficiency of this process results in the surface
atoms being in a high-energy state.
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25. No sooner did he replace the first valve than the
second ceased to conduct.
- But, admirable as were his (Huyghens's) labours, they
did not command universal assent. - These data are sufficient to be able to build up a
mathematical theory.
II
28. It was Rutherford and Soddy who first proposed a
general theory of radioactive transformation.
- R is some range, yet to be defined, of electrons
produced by quanta of energyW. - The chamber need not be clean, nor the illumination
as intense for alpha tracks as for electron tracks. - Difficulties in observation make the facts upon which
scientific laws are based less certain than we would like them
to be. - For the experiments I am about to describe, we want
a compass and a "bar" magnet. - The particular higher-order waves mentioned earlier
in this chapter are but special cases of a much more general
phenomenon about to be described. - Fortunately copper is widely distributed, its ores being
oxides and the carbonate. - Not all the light striking the water surface is reflected,
for some of it enters the water and is said to be refracted.
V 36. None of the above laws is followed by any of the
permanent gases quite rigorously.
- If the pressure were reduced sufficiently the positive
column v/ould disappear entirely and the Crooks dark space,
its boundaries becoming more and more indistinct, would
gradually fill the entire tube. - If иis a wave-function, so also in du/dt since the
wave-equation is a linear equation with constant coefficients. - Simple forms of these oscillations which do not depend
on a magnetic being present for their existence were first
predicted and observed by Tonks and Langmuir. - The survey does not appear to have been published,
nor did Dr. Ulrich indicate in his recent lecture how expensive
was the analysis to which he referred.
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- In this work clear proof was given that penetrating
showers do contain ionizing penetrating particles. - The five discontinuities shown to exist in the M region
are due to the five sublevels in the shell.
43. Were one to ignore the weak reflection at
approximately 10° and judge solely by the strong peak at
approximately 20° one would assign to NaCI a simple cubic
structure similar to КСI.
- The additional energy possessed by the photoelectron
after being torn from the atom is graduelly dissipated through
the formation of a multitude of low energy ions along its
path. - It is from such crystal measurements that all early
values ofX-ray wavelengths were determined.
у 46. General rules predicting the direction in which a process is influenced by outer forces are very desirable from a practical point of view.
III
47. Needless to say, the examination of unetched surface
should be followed by etching and further examination.
48. In liquid alloys there will always be some
decomposition however large the energy of dissociation may be.
49. In each case the symbol is followed by a superscript indicating the valence.
50.The tracer technique can be employed to follow the
process of electroplating.
51.There was no general argument as to the nature of
radiation; neither was there any convincing evidence as to the energy associated with the radiation.
52.Unfortunately the analysis now to be given will show
that the assumption would not be a legitimate one.
53.Notice that in this case it would be green rays which
would be doing the work of blackening the plate.
54.Only chemicals known to be chemically pure should
be used.
55.If we were to remove one electron by some means,
a net positive charge would be left.
56. Besides having confirmed certain consequences of
Nernst's theory of electrolytic solution pressures, the results
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of this investigation have led to the solution of another important problem.
IV
- The kinetic energy of the reaction is of course divided
between the product particles, with the lion's share going to
the lighter particle. - Small as the stars appear to us, there are many of
them much larger and hotter than the sun.
59. Were the observations rigorously correct and the
values of the unknown quantities finally determined affected
by no error, they would be many times more accurate than
we can hope to make them.
60. It is suggested that a first section of each article should be devoted to a statement of the particular problem and to a short summary of its history and previous work, to be followed by the modern advances.
61. Most of the primary radicals may be expected to
react with monomer even in the presence of inhibitor, the
action of the latter being confined principally to the
termination of chain radicals of very short time.
- Since the quantities e are equally likely to have positive
or negative values, the sum of the terms in the last line is
as likely to be positive as negative. - Turning to the metal phthalacyanides, we find all of
the above authors reporting observation of electrical
conductivity.
- The records show three separate groups of waves.
The first to arrive are waves in which the vibrations are
predominantly longitudinal. - These corpuscles have either no electric charge and
mass, or at any rate a charge and mass negligible as compared
with those of the electrons, minute as the latter are. - Alternatively, both antennas can be located at fixed
positions, with provisions being made to rotate the antenna
under test. - The half-life period is the number of seconds for the
activity to fall to half its original value, i. e. for half the
atoms to break up.
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V
68. Note that this effect does not necessitate complete
occupancy of the lower conduction levels, but only that the
density of states corresponding to the absorption constant
considered should occur at a higher energy.
69. The numbers given for the atomic weights must not
be taken to represent the actual weights in, say, grams or
pounds but rather as being proportional to them.
70. The point of view to which the number of objections
is minimum is the assumption that the electron, exhibiting
as it does both wave and corpuscular properties, consists of
a fortuitous conglomeration or concentration of waves of
different frequency as in Fig. 4—4.
71. It is possible to calculate to a fair degree of accuracy what should be the conductivity 'of the perfect crystal (at 0°K) of germanium or silicon when it is brought up to room temperature, say 300 °K.
- Nineteenth-century physics succeeded in achieving
the complete domination of the phenomena we observe
around us. - Another case where the motion of the electron is not
presumed by Wave Mechanics to follow the classical laws
of motion is when its associated wave meets with obstacles
in the path of propagation.
74. There are several precautions to be observed in making
such experiments.
75. Actually this theory, attractive as it is in its simplicity,
leads to a model of the photon having, so to put it, only
half the symmetry of the real photon.
76. Becquerel's discovery in 1896 was followed by the studies made by Rutherford, Soddy and Curie.
77. Preliminary qualitative experiments showed gradual
addition of dilute alkali hydroxide to a solution of chromous
chromide to result in the precipitation of a bluewhite basic
salt.
VI
78. Chemists have worked out an orderly fashion at least
for the more common anions such as arsenates, borates,
carbonates, halides, nitrates, phosphates and sulphates, to
mention only a few out of a list of hundreds of salts.
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79.It was only after Rutherford's discovery in 1911 that
an atom consists of a small, massive, positively charged
nucleus surrounded by electrons, that the theory could be
applied to quantitative description of atoms.
80.Because of the soft, large-grain structure of bismuth,
it was a major purpose to produce a mirror surface that
would not spread the neutron beam, and considerably more
difficult to obtain one that would retain this surface after
immersion in liquid oxygen.
81.Suppose fission is possible; then if it is to take place,
the system must pass from A to D. The obvious way for it
to do so is for the incident neutron or other particle, to
supply enough energy to bring that of the resulting compound
nucleus to a point lying aboveC.
82. General rules predicting the direction in which a process is influenced by outer forces are very desirable from a practical point of view.
83.While an ad hoc theory usually fits the facts, it is
frowned upon by the scientific world, because in nearly all
cases of such theories, it is not long before additional data
are discovered which the theory, made to fit only a specific
set of facts, fails to explain.
84.All too brief as this survey is, it will have shown that
laboratory research during the last few years has led to results
of the utmost interest almost each day.
85. While many more, and much more accurate
experiments will be needed, it is reasonably clear which kinds
of experiments are most likely to contribute significant
information.
86.Plutonium — 239 is obtained from uranium — 238,
as a result of radioactive capture of neutrons released in
reactors, followed by two relatively rapid stages of beta decay,
as stated above.
87.Although the alloys contained only copper and gallium,
the effects of the other elements likely to be present with gallium were also examined.
VII
88. Dry ashing and extraction of the ash is followed by
photometric determination of the catalytic influence of the
Ce—As reaction.
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89.The following example indicates the main features to
be considered when one decides whether to use correlation
or spectral analysis for a particular problem.
90.It was not until ten years after Bohr had predicted
correctly the energy states of hydrogen that the energy of
hellium in its ground state was calculated by Kramers on
Bohr's theory.
91.Their emission spectrum whether excited by light or
by alpha particles is quite different from that of pure
luminescent zinc-sulphate, the colours being green and blue
respectively.
92. It is common practice to designate the electrodes bye,сandb —emitter, collector and base. The practice will be followed in this book.
- Should the exciton remain at the particular atom,
both this atom and its neighbours would shift their positions
to new equilibrium values, emitting phonons during the
process. - The energy gap is responsible for semiconductors
being opaque and having metallic reflection in the optical
region.
95. More generally, a sufficient (but perhaps not necessary)
condition for the Born approximation to be valid would be
that the exponential decay length a-1 of the wave function
of the picked-up particle outside the nucleus be at least as
large as nuclear radius.
- Instead of observing a crystal while it is growing
another approach for studies is to observe the crystal surfaces
on which growth has been arrested. With this method of
observation much better techniques can be employed which
are therefore likely to yield more information. - It is the property of electrons to radiate energy when
accelerated that accounts for many ot the properties of the
layer in the upper atmosphere. - The theory in question assumes the variation in
conductivity on illumination to result from changes in n,
the density of conductivity, electrons or holes, as the case
may be. - To put the question in another way, how can the
presence of a slit through which a photon does not go prevent
that proton from reaching a part of the screen it would be
likely to reach if tthat slit were closed?
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100. The streams of ionized particles assumed to be
emitted at the time of flares and to escape sometimes from
the soler atmosphere and reach the Earth, giving rise to
sudden magnetic storm, also have velocities of the right order.
101. Counterbalancing the rate of energy generation are
various mechanisms of energy loss from the reaction region.
102. Hydrogen undergoes fusion at a much slower rate
that would deuterium or tritium under the same conditions.
103. It is not generally appreciated that during this period
there appeared to be possibilities of crystal amplifiers and
crystal oscillators becoming practical devices.
104. Finally one must remark that, whatever validity an application of the principle of equipartition may possess, it must be applied with caution to a rotating system.
- If retardation did not occur all tin objects would be
recrystallized each time the temperature cooled below 13.2 °C
and would rapidly disintegrate to powder. - This hypothesis, startling as it may seem at first
sight, appears, none the less, to contain a considerable element
of truth. - With equation of state adopted, with the virtual
coefficient assumed constant for a particular gas, the heat
capacity at constant volume is independent of the pressure.
108. The transistor followed by a phaseinverting
transformer, and the neutralyzing network are connected in
parallel at both input and output terminal pairs.
109. Included in this group are atmospheres containing
gasoline and other gases of similar hazard.
110. No complete and quantitative theory of
photoconductivity has yet been developed, nor, from the very
complexity of the problem, is an early solution to be expected.
111. The usual approximation is semiconductor statistics
corresponds to the second term in the brackets of (3.8)
being negligible.
112. By 1910 Planck's quantum theory and Einstein's
photoelectric equation together with various lines of
experimental evidence had made it clear that, impossible as
it then seemed, physicists would perhaps have to accept the
hypothesis that light itself possesses corpuscular charac
teristics.
113. A plate of conductivity g1is followed by a second
plate of nearly infinite conductivity.
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114. The last controlled experiment to be performed on
the gas would be a study of the relationship between
temperature and pressure, the volume being kept constant.
- In order to calculate the excitation energy, the
well-known semiempirical atomic mass formula is corrected
for its deviations known to be attributed to the effects of
nuclear shells. - Daring as at first sight this hypothesis appears to
be, there is nevertheless a whole series of experiments which
seem scarcely possible to explain on the wave theory, but
which can be understood at once if we accept the hypothesis
of the light quantum. - It is only through the general law of averages that
we can expect the effect of these fortuitous but systematic
errors to be completely eliminated. - The product of Сand C1 (time constant) should be
equal to or greater than the inverse of the lowest frequency
to be amplified by the stage. - A particle which is acted upon by a force which
varies directly with the distance from a fixed point will, if
displaced and released, execute a motion represented by the
above equation if no other forces, such as friction, come
into play. - Owing to the measures of A being made around the
pole as an axis, the apparent displacement due to a
given A A is less, the nearer the direction of the point p is
to that of the pole, the general law being: displacement —
cos bDl. - The old theory of heat which considered heat to be
a fluid could not explain why two pieces of ice could be
made to melt when rubbed against each other. - To complete the parallelism with the photonfield
case, the energy and momentum of the particle are also
related to the frequences and wave number of the wave
function according to equation. - The theory of propagation of the detonation wave
was worked out first of all to account for observations made
on the speed of gas explosion. - By absorption of photons of higher frequency and
therefore greater energy content, electrons of correspondingly
greater velocity should be produced as was found to be
invariably the case.
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- It is found to be easy to arrange experiments in
which the loss of conductivity during the time the ions are
in the gas is due principally to the process of recombination. - Light is considered to be a hail of light quanta,
which knock out an electron the moment they strike a metal
particle. - I shall merely draw attention to the majestic curve
which physical theory would have described, were this new
theory to receive definite confirmation. - Different as they may appear at first sight, the two
forms of the new Mechanics are found to coincide in the
last analysis. - Careful experiment showed that electrolytes obeyed
Ohm's law, the current being proportional to the e. m, f. no
matter how small the latter might be.