日本光纤放大器的现状及发展

随着光通信的发展，光纤放大器的地位越来越重要，本文结合日本的情况，介绍了光纤放大器的原理，构造和在光纤传输系统中的应用。     

Monte Carlo based electronic structure techniques: analysis and applications

Monte Carlo based variational electronic structure techniques are examined. The nature of the convergence of such methods, associated extrapolation methods and techniques for wavefunction optimization are discussed. These techniques are illustrated with an application to the H⁺₃ system. Compact and accurate correlated wavefunctions for this system are reported.     

Re-measurements of partial photoionization cross-sections of CH4, NH3 and H2O at 58.4 nm by He(I) photoelectron spectroscopy

Angle-resolved photoelectron spectroscopy (ARPES) is now a sophisticated and particularly powerful technique for studying the electronic structure of matter; in addition, the photoelectric effect has been of great significance in the history of 20th-century physics. This article seeks to uncover the origins and chart the development of the ARPES field, and focuses on the first half of this century; that is, up to the beginnings of the modern phase in the late 1960's. It is suggested that present workers will find interest in, and indeed profit from a knowledge of, the enormous experimental effort that was made to acquire quality data, the frustrating attempts that were initially made to understand them theoretically, and the contribution of early wave-mechanics, which brought order to a troubled field and thereby provided the necessary foundation for current studies. In addition, it is noted that the physicists involved often obtained inspiration and important insights which led them into studies of other significant problems of 20th-century physics.     

如何成功地获取认证生产线和认证产品的认证注册

详细介绍了电子部二十三所通过生产线和产品认证注册的工作过程,将其归纳为从“作出注册决定并制定行动计划”到“取得注册”７个步骤。     

Palladium-catalyzed addition reaction of olefins,carbon tetrachloride and carbon monoxide in alcohols to give 2-alkyl-4,4,4-trichlorobutanoates

Pd(OAc)₂ combined with PPh₃ is a good catalyst for the addition reaction of CCl₄ and CO to olefins in ethanol to afford ethyl 2-alkyl-4,4,4-trichlorobutanoates. The esters were obtained in satisfactory yields when the reaction was carried out at 50° in the presence of K₂CO₃ under CO pressure.     

Flow enthalpimetric determination of glucose, based on oxidation by 1,4-benzoquinone and use of an immobilized glucose oxidase column

A flow enthalpimetric method for the determination of glucose is presented. The method is based on the reaction of glucose with 1,4-benzoquinone in the presence of immobilized glucose oxidase. d-Glucose concentrations ranging from 0.02 to 75mM can be determined. The method is applicable to the determination of glucose in soft drinks, wines, beers, jams and serum.     

Molecular structure of carbonyl fluoride as studied by gas electron diffraction and microwave data

The molecular structure of carbonyl fluoride has been determined by electron diffraction. The results have been used in conjunction with the rotational constants reported by Carpenter in a combined structure analysis. The values so obtained are r_z (C=O) = 1.1717 ± 0.0013 Å, r_z (C-F) = 1.3157 ± 0.0005 Å, and ∠_zF-C-F = 107.71 ± 0.08°. These agree with the corresponding parameters estimated by Carpenter from the rotational constants alone. The effective constants, α₃, representing the cubic anharmonicity of bond stretching vibrations have been estimated.     

Sesquiterpene constituents of two liverworts of genus diplophyllum: Novel eudesmanolides and cytotoxicity studies for enantiomeric methylene lactones

The steam distillates (or hexane extracts) of the liverworts Diplophyllum albicans (L.) Dum. and D. taxifolium (Wahl.) Dum. are largely a mixture of sesquiterpenes. Both species elaborate, among the hydrocarbons, mainly ent-α-selinene (8a) and ent-selina-4,11-diene (8b) together with anastreptene (1) and β-elemene (9). The major component of each essential oil was diplophyllin (10), a novel ent-eudesmanolide. The structure of diplophyllin was established by correlation with tetrahydro-isoalantolactone (17). In addition, the enantiomers of diplophyllin and diplophyllolide-A (16) were obtained on acid isomerization of isoalantolacetone (14a). Diplophyllin shows significantly greater activity against human epidermoid carcinoma (KB cell culture, ED₅₀? 8 μ $\text{g}\text{ml}$) than its enantiomer: the first demonstration (to our knowledge) of optical selectivity for this type of cytotoxicity. Among the more polar constituents of D. albicans were 9α-acetoxy-diplophyllin, and several sesquiterpene alcohols including albicanol (22).     

Picosecond time-resolved Sn← S1 absorption spectrum of the tetracyanobenzene-toluene complex

The time-resolved absorption spectrum of the lowest excitcd singlet state (S₁) over the range 3 — 10 ps after 0.5 ps pulse excitation of the charge-transfer complex of 1,2,4,5-tetracyanobenzene and toluene shows an evolution with a 5 ± 3 ps time constant due to changes in configurations of the complex in S₁ associated with the reorientational relaxation of the solvent.