IGCT三电平变流器系统的研制

本文介绍了大功率IGCT三电平变流器系统的主电路结构及控制系统的设计，实验结果证明该系统结构可靠、运行稳定，将来可以应用到大功率冷轧机传动系统中。     

Calorimetric and nuclear byproduct measurements in electrochemical confinement of deuterium in palladium

We present the results of a new experiment with our multicell set-up implemented with mass spectrometric measurements of⁴He and a highly improved neutron detector. The excess heat measured is comparable with the results of other laboratories, but no neutrons were found and the tritium excess was lower than expected from the power excess. ⁴He has been measured in the electrolysis gases and a tentative correlation of ⁴He with excess power is presented and discussed.     

紫花地丁中汞的原子荧光法测定

利用还原气化的非色散型装置，以湿法消解的方式，建立了原子荧光测定紫花地丁中痕量汞的测定方法，同时比较了不同玻璃仪器的洗涤方法和不同的定量方法，试验回收率在86．9％－110．8％之间，误差＜8．5％，通过对实际样品的测定，得到了满意的结果。     

Analysis of volatile organic compounds in polymers by dynamic headspace and gas chromatography/mass spectrometry

An experimental method for the analysis of volatile organic compounds in polymers is described. The technique involves dynamic headspace sampling, collection, and concentration of the volatiles in a cold trap, followed by capillary column gas chromatography/mass spectometry. Flow switching is carried out by the Deans switching technique. Four technical polymers used as pharmaceutical packaging materials have been analyzed in order to demonstrate the method.     

Cold trap/reinjection interface for two-dimensional gas chromatography

The construction and evaluation of an interface for two-dimensional gas chromatography is described. The interface consists of commercially available components and is attachable to available gas chromatographs without any major modifications. The interface has been constructed so as to permit “heartcutting” as well as solute band concentration. Trapping is performed in a simple cold trap of fused silica. Flow switching is accomplished by Deans switching. Factors of the over-all chromatographic performance are examined.     

简易毛细管气相色谱冷柱头进样法

介绍了一种在无冷柱头进样器和特殊注射器情况下简便可行的冷柱头进样技术。以海洛因、秋水仙碱、正三十烷醇为研究对象，考察了本方法的定性、定量偏差，提出两种溶质聚焦方法。     

Cryogenic absorption cells operating inside a Bruker IFS-125HR: First results for CH4 at 7 μm

New absorption cells designed specifically to achieve stable temperatures down to 66 K inside the sample compartment of an evacuated Bruker IFS-125HR Fourier transform spectrometer (FTS) were developed at Connecticut College and tested at the Jet Propulsion Laboratory (JPL). The temperature stabilized cryogenic cells with path lengths of 24.29 and 20.38 cm were constructed of oxygen free high conductivity (OFHC) copper and fitted with wedged ZnSe windows using vacuum tight indium seals. In operation, the temperature-controlled cooling by a closed-cycle helium refrigerator achieved stability of ±0.01 K. The unwanted absorption features arising from cryodeposits on the cell windows at low temperatures were eliminated by building an internal vacuum shroud box around the cell which significantly minimized the growth of cryodeposits. The effects of vibrations from the closed-cycle helium refrigerator on the FTS spectra were characterized. Using this set up, several high-resolution spectra of methane isotopologues broadened with nitrogen were recorded in the 1200-1800 cm⁻¹ spectral region at various sample temperatures between 79.5 and 296 K. Such data are needed to characterize the temperature dependence of spectral line shapes at low temperatures for remote sensing of outer planets and their moons. Initial analysis of a limited number of spectra in the region of the R(2) manifold of the ν₄ fundamental band of ¹³CH₄ indicated that an empirical power law used for the temperature dependence of the N₂-broadened line widths would fail to fit the observed data in the entire temperature range from 80 to 296 K; instead, it follows a temperature-dependence similar to that reported by Mondelain et al. [17] and [18]. The initial test was very successful proving that a high precision Fourier transform spectrometer with a completely evacuated optical path can be configured for spectroscopic studies at low temperatures relevant to the planetary atmospheres.     

回收LNG冷能的新型碳二烃两级膨胀朗肯循环

提出了一种新型的回收LNG冷能的两级膨胀朗肯动力循环,可以乙烯或乙烷作为工质。此工艺流程采用多股流低温板翅式换热器(MSCHE)作为主要设备,使工质两级膨胀并采用回热过程,可以使循环的冷能利用效率得到明显提高。针对此工艺分别以乙烯或乙烷为工质,与LNG直接膨胀结合和不结合,共四种方案采用HYSYS软件进行工艺模拟,并对模拟结果进行了比较和分析,可得出无LNG膨胀的乙烯两级膨胀工艺流程最为合理,其冷能和火用的利用率可以分别达到19.67%和21.75%。