高压直流断路器吸能装置各柱中电流不均衡性的研究

高压直流断路器吸能装置中氧化锌阀片的并联柱数愈多、每柱中串联的氧化锌阀片的片数愈少,则电流不均衡分布的问题愈严重.计算表明,只要合理地进行搭配吸能装置各柱中的氧化锌阀片,电流的不均衡性可以减少到很低的水平.     

离子注入均匀性的工艺控制

叙述了影响离子注入均匀性的几个主要因素,其中包括束流品质,离子束聚焦与扫描以及束流大小选择等。同时介绍了如何控制这些因素来获取优异的注入均匀性,通过这些控制手段,均匀性可以优于１ ％ ,结果令人满意。     

Spectroscopy and upconversion processes in YAlO3:Ho crystals

Emission from the high lying excited states, energy transfer, and upconversion processes are investigated in YAlO₃:Ho³⁺. Selectively excited emission spectra in the range from 300 to 800 nm starting from the ³D₃, ³G₅, ⁵F₃, ⁵S₂ and ⁵F₅ multiplets were measured at 15 K. This, together with the detailed absorption and excitation measurements at 15 K allowed determination of the Stark energy levels of Ho³⁺ ions in YAlO₃ up to UV energies. The ⁵S₂ fluorescence decays were recorded as a function of temperature and Ho³⁺ concentration in order to investigate the process of quenching of fluorescence due to cross relaxation among two ions. Conversion of red and infrared laser radiation to green ⁵S₂ and blue ⁵F₃ emission is reported. Under pulsed resonant excitation of the ⁵F₅ or ⁵I₅ levels the upconversion was found to be due to energy transfer process between two excited ions. The photon avalanche effect was observed under cw excitation around 585 nm.     

柴油汽车排放控制技术

简述我国排放法规以及柴油汽车排放对人和环境的影响，较为详细地介绍了柴油汽车的主要排放控制技术，对今后的研究方向提出了见解。     

Contamination due to process gases

A survey is given of the BOC Group technical research programs, whose purpose is to relate purity in gas processing to ULSI device parameters. Results from the following research programs are presented: how inert gas purity affects the Ti silicide for IGFET metallization; the effects of argon versus nitrogen used in silicon gate oxidation process steps; and preliminary work on a new gas analytical tool, Atmospheric Pressure Ionization Mass Spectrometry (APIMS), which allows measurement of sub ppb impurity levels in processing gases.     

Determination of cracking resistance of thermal spray coatings during four-point bend testing using an acoustic emission technique

An acoustic emission (AE) technique was used for the determination of the onset of cracking of thermal spray self-fluxing NiCrFeBSi coatings under tensile loading using a 4-point bend testing apparatus. These coatings were flame sprayed on 42CrMoS4 cylinders having different diameters. Two different post-treatment fusing processes, induction, and flame fusing, were used. Along with the investigations of the effect of cylinder diameters and fusing processes onto the cracking resistance of the coatings, the effect of the same two parameters on the residual stresses was also investigated. Results show that, independently of the diameter of the cylinder, the flame-fused coatings possess a higher cracking resistance than their induction-fused counterparts, i.e., that the strain to fracture is higher for the flame-fused coatings. A correlation between the strain to fracture and the residual strain in the coatings has been established. This study points out that the combination of an AE technique with a bending test apparatus shows some major benefits to obtain important information on the relative ductility of thermal spray coatings.     

Study on Monoxide Emission Spectrometry of Rare Earth Elements Ⅰ. Determination of Sm in Rare Earth Concentrate by Dual Wavelength Method

ＳｔｕｄｙｏｎＭｏｎｏｘｉｄｅＥｍｉｓｉｏｎＳｐｅｃｔｒｏｍｅｔｒｙｏｆＲａｒｅＥａｒｔｈＥｌｅｍｅｎｔｓⅠ．ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆＳｍｉｎＲａｒｅＥａｒｔｈＣｏｎｃｅｎｔｒａｔｅｂｙＤｕａｌＷａｖｅｌｅｎｇｔｈＭｅｔｈｏｄＺｈａｎｇＺａｉｚ...     

An acoustic-emission characterization of the failure modes in polymer-composite materials

A new methodology for the analysis of failure modes in composite materials by means of acoustic emission techniques has been developed. A single-carbon-fiber composite based on a polyester matrix, has been used as a simple model. The occurrence of fiber-breakage during tensile loading tests has been observed by a polarized light microscope and concurrently detected by a resonant acoustic probe. The resonant probe has been used as a trigger for the reading of fiber failure events. Single acoustic emission events from a wide-band probe has been recorded for FFT Analysis. The single-fiber specimen, having a unique failure mode, has advantages for the standardization of AE techniques for the quantitative analysis of failures in polymer-composite materials.

The same procedure can be exploited to investigate other failure modes namely, fiber matrix solidus debonding and matrix cracking.     

Secondary ion emission of Fe-Ni alloys in the temperature range including the Curie point

The temperature dependence of secondary ion emission was investigated for Fe-Ni ferromagnetic alloys with different Curie points T_c and elemental composition: 35% Ni 65% Fe (T_c=240°C), 40% Ni 60% Fe (T_c=360°C), and 50% Ni 50% Fe (T_c=530°C). The alloy 79% Ni 16% Fe 5% Mo (T_c=345°C) was also studied. The spatial distribution of Ni⁺ and Fe⁺ secondary ions emitted from the (1 1 1) face of invar and permalloy single crystals was shown to be anisotropic with pronounced ion-yield maximum for both components in the 〈1 1 0〉 directions. The shape of the energy distribution of Ni⁺ and Fe⁺ ions was found to be virtually identical for all the alloys under investigation with a most probable energy at 7 eV and a width at half-maximum of 12 eV. The temperature dependence of the Ni⁺ and Fe⁺ emission has a maximum near the Curie point of the investigated alloys and another maximum at the Curie point of nickel which may indicate the precipitation of nickel into microscopic islands on the surface as a result of heating and sputtering. Auger analysis of the surface composition in the surface layers showed a variation in concentration of oxygen and carbon atoms when Fe-Ni alloys pass from the ferromagnetic to the paramagnetic state and this must affect also the secondary ion emission of alloy components.     

固定场源建场测深仪原理

CJY16固定场源建场法仪器用于非地震勘探方法勘查地质结构,它综合地震仪器与电法仪的特点,由多道有线遥测数据采集系统与强电流发射系统组成,是一种多功能电法勘探仪器。连接不同传感器,可分别用于建场测深法、激发极化法、频率测深、震电法、电震法等。CJY16在新疆探区生产中,使用效果良好,取得了较好的经济效益。