1-氨基环丙烷-1-羧酸的合成: 新型植物生长调节剂

本文报道了合成1-氨基环丙烷-1-羧酸的简便而价廉的方法,即乙酰乙酸乙酯法和α-氰乙酸乙酯法;并测定了产品的结构。     

发泡PVC混合材料吸声性能的研究

发炮塑料是一种常用的吸声降噪材料，发泡ＰＶＣ－无机物混合物吸声材料是一种性能优良的新型吸声材料，它的吸声性能尤其是中低频吸声性能明显比聚氨酯、聚苯乙烯等发泡聚合物好。重点讨论了材料厚度、容重、无机物含量，无机物粒度、加热时间对材料吸声性能的影响。     

CHARACTERISTICS OF CLAY MINERALS IN ASIAN DUST AND THEIR ENVIRONMENTAL SIGNIFICANCE

The objectives of this research were to characterise the clay minerals composition of soil-derived dust in Northern China and to set up a mineralogical signature to trace their origin. Mineral composition of aerosol particles was investigated at Aksu, Dunhuang, Yulin, Tongliao and Changwu during an intensive field campaign period of ACE-Asia. The results show that the kaolinite （K） to chlorite （C） ratio is sensitive to the regional origin of Asian dust. Western source areas （represented by Aksu） displayed the lowest K/C ratio of 0.3 （average）, while it was found to increase up to 0.70 （average） upon moving towards northern source areas （represented by Yulin）. By studying transported dust in a deposition area representative of the Chinese Loess Plateau, the usefulness of the K/C ratio, when associated with back air-mass trajectories, was found to lie in revealing the origin of the dust. Comparison of the mineralogical data between Asian dust and Sahara dust, shows that the K/C ratio is also an effective signature to identify the source areas on a hemisphere scale.     

实现高重复率双脉冲激光器的新方法

本文分析了双脉冲运转的种子注入激光器及其存在的问题,在此基础上首次提出了用相位共轭主振荡器功率放大(MOPA)激光器组成高重复率n脉冲运转激光器系统的新方法,获得了重复率可达几千Hz且高相干度的脉冲输出,该系统具有相当好的性能,可望替代种子注入激光器而成为动态全息检测领域的一种新光源.     

Fast Synthesis of Submicron Zeolite Y Using Microwave Heating

Kinetics and Catalysis - Submicron zeolite has become the focus of research because of its high thermal stability, high catalytic activity, and uniform size. A rapid method for synthesizing...     

一种基于LabVIEW的光谱仪设计

利用虚拟仪器开发软件LabVIEW设计了一台光谱仪,使用CCD一次接收整个光谱,同时利用LabVIEW高度集成化的模块进行显示、分析等处理,效率高,开发周期短,仪器使用方便,功能多且易于扩展.     

聚乙烯泡沫单填充纸瓦楞管的轴向跌落冲击缓冲吸能特性

利用聚乙烯闭孔泡沫单填充纸瓦楞管开展轴向跌落冲击试验,对比分析了结构参数和冲击参数对其缓冲吸能特性参数（比吸能、行程利用率、压缩力效率、比总体效率）的影响。结果表明,X向单填充管的动态缓冲吸能特性优于Y向单填充管,而静态缓冲吸能特性差于Y向单填充管。正四边形单填充管的动态缓冲吸能特性优于正五、六边形单填充管,X向正四边形单填充管的比吸能相较于正五、六边形管分别提高了114.4%和182.3%。对于跌落冲击压缩,单填充管的比吸能、行程利用率、比总体效率随着管长比的增大而减小,管长比为1.4的X向单填充管的比吸能相较于管长比为2.2和3.0的单填充管分别增加了45.8%和117.9%,而压缩力效率随着管长比的增大而增大。随着跌落冲击质量或冲击能量的增加,比吸能、行程利用率、压缩力效率和比总体效率皆呈增大趋势,冲击质量对X向单填充管的影响较大,而冲击速度则对Y向单填充管的影响较大。

     

DISTRIBUTION OF CARBONACEOUS AEROSOL DURING SPRING 2005 OVER THE HORQIN SANDLAND IN NORTHEASTERN CHINA

The objective of this study was to characterize the elemental carbon and organic carbon （EC and OC, respectively） content of aerosol particles （PM2.5） collected at Tongliao, a site in the Horqin Sandland of northeastern China. During spring 2005, the PM2.5 mass concentration was 126±71 μg·m^-3, with higher dust concentrations during five dust storms than on non-dusty days （255±77 vs. 106±44 μg·m^-3）. The average OC and EC concentrations in PM2.5 determined by a thermal/optical reflectance method were 15.7±7,3 μg·m^-3 and 3.3±1.7 μg·m^-3, respectively, and carbonaceous aerosol accounted for 9.9% of the PM2.5 mass during dust storms compared to 21.7% on normal days. The average ratios of OC to EC during dust storms were similar to those on non-dusty days, and the correlation coefficient between OC and EC was high, 0.86. The high OC/EC ratios, the distributions of eight carbon fractions, and the strong relationship between K with OC and EC indicate that rural biomass burning was the dominant contributor to the regional carbonaceous aerosol.     

Fabrication of χ{2) Grating in Poled Polymer Waveguide Based on Direct Laser Beam Writing

A simple method is described for fabricating high resolution χ⁽²⁾ grating in poled polymer waveguide. It is found that the second-order nonlinearity of corona-poled polymer thin film is erased after visible laser (450 nm) irradiation. The mechanism of the erasure of χ^{2) is discussed. High resolution χ⁽²⁾ grating structure in several poled polymer waveguides is demonstrated by direct writing with a cw He-Cd laser.On leave from the Department of Optical Instruments, Zhejiang University, Hangzhou, Zhejiang Province, 310027, P.R. of China.