以理论为先导以实践促提高

探讨在现行电子类实验教学大纲下的验证性实验如何与实际电子制作相结合，使学生由被动实验转为主动实验。通过制作发现问题、分析问题并解决问题，进一步巩固和加深对相关理论的理解，培养学生的实践能力。     

K-shell ionization by protons for Cr,Cu, In and by alpha-particles for Cr,Cu

K-shell ionization cross sections have been determined for Cr, Cu and In at proton bombardment in the energy region from 0.9 to 2.5 MeV. The same cross sections were determined for Cr and Cu at alpha bombardment in the 0.9–4.0 MeV region. The experimental results are compared with five different theoretical calculations.     

Neutrino,by Frank Close

The Structure of Low-medium Mass Nuclei. Edited by J. P. Davidson and B. D. Kern. (University Press of Kentucky, 1973.) [Pp. viii+ 302.] $12.50. Scope: Conference Proceedings/Library (reference). Level: For specialists only; specialist/postgraduate.

Computational Physics. By D. Potter. (John Wiley, 1973). [Pp. xi+304.] £6.95. Scope: Treatise/textbook. Level: Postgraduate.

Cooperative Phenomena. Edited by M. Haken and M. Wagner. (Springer-Verlag, Berlin, Heidelberg and New York, 1973.) [Pp. xii+ 458.] $59.40. Scope: Treatise. Level: Specialist.

Polymers. Chemistry and Physics of Modern Materials. By J. M. G. Cowie. (Intertext, 1973.) [Pp. 298.] Scope: Textbook/treatise. Level: Undergraduate.

Space Dynamics. Vol. 1. By J. M. J. Kooy. (Stam Technical Publications, Cologne, 1972.) [Pp. xx + 473.] £12.00. Scope: Treatise/textbook. Level: Undergraduate.

Flectron Spin Resonance of Paramagnetic Crystals. By L. A. Sorin and M. V. Vlasova (translated by P. Cluck). (Plenum Press, 1973.) [Pp. xii+ 254.] $26.00. Scope: Treatise/Textbook. Level: For specialists only.

Nuclear Physics. By R. Bowler. (Pergamon, 1973.) [Pp. xi+ 420.] £6.00. Scope: Treatise/Textbook. Level :Undergraduate/post-graduate.

Electronic Transitions and the High Pressure Chemzstry and Physics of solids. By H. G. Drickamer and C. W. Frank. (Chapman and Hall, 1972.) [Pp. x + 220.] £5.00. Scope: Treatise Textbook. Level: Specialist/post-graduate.

Towards Quantum Mechanics. By J. Cunningham. (Transworld Publishers, 1973.) [Pp. 92] 75p. Scope: Textbook. Level: Undergraduate.

An Introduction to the Quantum Chemistry of Solids. By C. M. Quinn. (Clarendon Press; Oxford University Press, 1973.) [Pp. viii + 308.] £7.00. Scope: Textbook. Level: Postgraduate/undergraduate.

Magnetically Ordered Crystals Containing Impurities. By Yu. A. Izyumov and M. V. Medvedev. (Consultants Bureau, 1973.) [Pp. x+ 168.] $34.00. Scope: Monograph. Level: Specialist/post-graduate.

Tensors and Group Theory for the Physical Properties of Crystals. By W. A. Wooster. (Clarendon Press: Oxford University Press, 1973.) [Pp. x + 344.] $7.00. Scope: Textbook. Level: Post-graduate/undergraduate.

Magnetic Interactions in Solids. By H. J. Zeiger and G. W. Pratt. (Clarendon Press: Oxford University Press, 1973.) [Pp. xv+ 660.] £19.50. Scope: Treatise/textbook. Level: Postgraduate.

Electrical Breakdown in Gases. Edited by J. A. Rees. (Macmillan, 1973.) [Pp. ix+ 294.] £7.95. Level: Specialist/postgraduate.

Introduction to Experimental Nuclear Physics. By R. M. Singru. (Wiley-Eastern, New Delhi, 1972). [Pp. x+ 195.] Scope: Textbook. Level: Postgraduate; undergraduate.

Luminescence of Crystale, Molecules and Solublea. Edited by F. Williams. (Plenum Press, 1973.) [Pp. xix+ 723.] $37.00. Scope: Conference Proceedings; Library. Level: For specialists only; Specialist/postgraduate.

Turbulence in the Free Atmosphere. By N. K. Vinnichenko, N. Z. Pinus, S. M. Shmeter and G. N. Shur. (Consultants Bureau, 1973.) [Pp. x+ 168.] $34.00. Scope: Survey. Level: Specialist/postgraduate.

Weather Forecasting as a Problem in Physics. By A. S. Monin, translated by P. Superak. (M.I.T. Press, 1972.) [Pp. x+ 199.] £5.65. Scope: Survey. Level: Specialist/post-graduate; undergraduate.

Interactions between Electromagnetic Fields and Matter. By K. H. Steiner. (Pergamon Press, 1973.) [Pp. xvi+ 351.] £12.50. Scope: Treatise; Library (reference). Level: For specialists only.

New Developments in Semiconductors. Edited by P. R. Wallace, R. Harris and M. J. Zuckerman. (Noordhoff International, Leyden, 1973.) [Pp. viii+ 584.] D fl. 115.40. Scope: Survey. Level: Specialist/postgraduate.

Electromagnetic Fields, Energy and Waves. By L. M. Magid. (John Wiley, 1972.) [Pp. xxiv+ 781.] £5.80.

$EAlectricit$eA Magn$eAtisme Cours. By P. Baruch, M. Hulin and J. F. P$eAtroff. (Hermann, 1972.) [Pp. 318.] 49F.

The Theory of Electrical Conduction and Breakdown in Solid Dielectrics. By J. J. O'Dwyer. (Clarendon Press: Oxford University Press, 1973.) [Pp. ix+ 317.] £10.00. Scope: Treatise/Textbook. Level: specialist/post-graduate.

Le Froid. By Fernand Laurent. (Presses Universitaires de France, 1972.) [Pp. 124. Scope: Survey. Level: Undergraduate.

Paradoxes of Physics. By P. Chambadal translated by M. F. Ingham. (Transworld Publications, 1972.) [Pp. 186.] 85p. Scope: Treatise/textbook. Level: Undergraduate.

Revolutions an Physics. By B. M. Casper and R. J. Noel. (W. W. Norton, 1972.) [Pp. x+ 479]. $8.95. Scope: Textbook. Level: Undergraduate.

The Field Concept in Contemporary Science. By M. Sachs. (C. C. Thomas, 1973.) [Pp. xi+ 129.] $9.75. Scope: Survey. Level: Undergraduate.

Methods of Mathematical Physics. (3rd Edition.) By H. Jeffreys and B. Jeffreys. (Cambridge University Press, 1972.) [Pp. v+ 718.] £3.80. Scope: Textbook. Level: Postgraduate.

M$oUssbauer Effect Data Index. Edited by J. G. Stevens and V. E. Stevens. (Plenum Press, 1972.) [Pp. x+ 430.] $37.50. Scope: Survey; library (reference). Level: For specialists only.

The Boltzmann Equation, Theory and Applications. Edited by E. G. D. Cohen and W. Thirring. (Springer-Verlag, 1973.) [Pp. 642.] $54.80. Scope: Conference Proceedings. Level: Specialist/postgraduate.

Introduction to Diffraction, Information Processing and Holography. By F. T. S. Yu. (M.I.T. Press, 1973.) [Pp. xii+ 366.] £6.75. Scope: Textbook. Level: Specialist/postgraduate; undergraduate.

Magnetic Properties of Rare Earth Metals. Edited by R. J. Elliott. (Plenum Press, 1973.) [Pp. vii+ 425.] $32.00. Scope: Treatise; survey. Level: Specialist/post-graduate.

Proceedings of the International Conference on Nuclear Moments and Nuclear Structure, Osaka, September, 1972. Edited by H. Horle and K. Sugimoto. (Physical Society of Japan, 1973.) [Pp. x+ 637.] 9000 yen-£6.00. Scope: Conference Proceedings. Level: Specialist/postgraduate.

Thermodynamics of Solids. Second Edition. By R. A. Swalin. (John Wiley, 1973.) [Pp. xii + 387.] £8.70. Scope: Treatise/textbook. Level: Postgraduate; undergraduate.

Entropy. By J. Zernike. (Kluwer-Deventer, The Netherlands, 1972.) [Pp. 150.] Hf 34.75. Scope: Treatise/textbook. Level: Specialist/postgraduate; undergraduate.

The Foundations of Modern Science. By J. B. Marion. (John Wiley, 1973.) [Pp. vii+ 333.] £5.50.

The Logical Basis of Quantum Mechanics. By E. Scheibe. (Pergamon, 1973.) [Pp. viii+ 204.] £6·00. Scope: Treatise; survey; library; library (reference). Level: Specialist/post-graduate.

Guide to Electronic Measurements and Laboratory Practice. S. Wolf. (Prentice-Hall, 1973.) [Pp. xii+ 494.] Price not stated. Scope: Survey.

The Work of the Rutherford Laboratory, 1972. Edited by J. R. Smith and F. M. Telling. (SRC, 1973.) [Pp. 215.] £1.50. Scope: Library (reference). Level: Specialist/post-graduate.

Daresbury Nuclear Physics Laboratory Annual Report, 1972. (SCR, 1973.) [Pp. iv+ 141.] Scope: Library (reference). Level: Specialist/post-graduate.

Elementary Electromagnetic Theory. By B. H. Chirgwin, C. Plumpton and C. W. Kilmister. (Pergamon, 1973.) [Pp. viii+ 160.] £3.00; (flexi, £1.85.) Scope: Textbook. Level: Undergraduate.

Physical Chemistry of Fast Reactions. (Volume 1). Edited by B. P. Levitt. (Plenum Press, 1973.) [Pp. viii+ 332.] $26.00. Scope: Treatise/textbook; Survey. Level: Specialist/postgraduate.     

Radiation force caused by scattering, absorption, and emission of light by nonspherical particles

General formulas for computing the radiation force exerted on arbitrarily oriented and arbitrarily shaped nonspherical particles due to scattering, absorption, and emission of electromagnetic radiation are derived. For randomly oriented particles with a plane of symmetry, the formula for the average radiation force caused by the particle response to external illumination reduces to the standard Debye formula derived from the Lorenz–Mie theory, whereas the average radiation force caused by emission vanishes.     

K-shell ionization by protons for Cr, Cu, In and by alpha-particles for Cr, Cu

K-shell ionization cross sections have been determined for Cr, Cu and In at proton bombardment in the energy region from 0.9 to 2.5 MeV. The same cross sections were determined for Cr and Cu at alpha bombardment in the 0.9–4.0 MeV region. The experimental results are compared with five different theoretical calculations.     

Fast, low-noise, mode-by-mode, cavity-enhanced absorption spectroscopy by diode-laser self-locking

A new technique of cavity enhanced absorption spectroscopy is described. Molecular absorption spectra are obtained by recording the transmission maxima of the successive TEM_oo resonances of a high-finesse optical cavity when a Distributed Feedback Diode Laser is tuned across them. A noisy cavity output is usually observed in such a measurement since the resonances are spectrally narrower than the laser. We show that a folded (V-shaped) cavity can be used to obtain selective optical feedback from the intracavity field which builds up at resonance. This induces laser linewidth reduction and frequency locking. The linewidth narrowing eliminates the noisy cavity output, and allows measuring the maximum mode transmissions accurately. The frequency locking permits the laser to scan stepwise through the successive cavity modes. Frequency tuning is thus tightly optimized for cavity mode injection. Our setup for this technique of Optical-Feedback Cavity-Enhanced Absorption Spectroscopy (OF-CEAS) includes a 50 cm folded cavity with finesse ∼20 000 (ringdown time ∼20 μs) and allows recording spectra of up to 200 cavity modes (2 cm⁻¹) using 100 ms laser scans. We obtain a noise equivalent absorption coefficient of ∼5×10⁻¹⁰ cm⁻¹ for 1 s averaging over scans, with a dynamic range of four orders of magnitude.     

Antimatter,by F. Close

While high resolution electron microscopy has been in use for many years, with steadily improving image resolution, most modern microscopes can provide complementary information on the chemical composition of very small volumes of material. This advance is very important and enormously extends the range of practical applications for the electron microscope. This review describes the basic principles and techniques of high resolution imaging and analysis, in both the conventional and scanning electron microscope, noting in each case the resolution that may be achieved.     

On the annoyance caused by impulse sounds produced by small, medium-large, and large firearms

A laboratory study was designed in which the annoyance was investigated for 14 different impulse sound types produced by various firearms ranging in caliber from 7.62 to 155 mm. Sixteen subjects rated the annoyance for the simulated conditions of (1) being outdoors, and (2) being indoors with the windows closed. In the latter case, a representative outdoor-to-indoor reduction in sound level was applied. It was anticipated that the presumed additional annoyance caused by the "heaviness" of the impulse sounds might be predicted from the difference between the C-weighted sound exposure level (CSEL; LCE) and the A-weighted sound exposure level (ASEL; LAE). In the outdoor rating conditions, the annoyance was almost entirely determined by ASEL. The explained variance, r2, in the mean ratings by ASEL was 0.95. In the indoor rating conditions, however, the explained variance in the annoyance ratings by (outdoor) ASEL was significantly increased from r2 = 0.87 to r2= 0.97 by adding the product (LCE-LAE)(LAE-alpha) as a second variable. In combination with a 12-dB adjustment for small firearms, the present results showed that for the entire set of impulse sounds rated indoors with windows closed, the rating sound level, Lr, is given by Lr=LAE +12dB+beta(LCE-LAE)(LAE-alpha), with alpha=45dB and beta=0.015dB(-1). For the outdoor rating condition, the optimal parameter values were equal to alpha=57 dB and, again, beta=0.015 dB(-1). In validation studies, in which the effects of the present rating procedure will be compared to field data, it has to be determined to what extent the constants alpha and beta have to be adjusted.