磁头润滑面形状对气动力特性的影响

该文采用微分离散差分方法求解滑流条件下的修正Reynolds方程.对于一阶导数间断的物理量-气膜厚度采用高精度保凸性磨光法进行处理.给出了气膜压强分布立体图以及几种因加工误差造成磁头滑块润滑面变形的误差型面的飞升曲线,中心线上压强分布,压力中心和负载随加工误差大小的变化情况,指出了磁头滑块润滑面加工时宁凸勿凹的倾向性意见.

Non-resonant third-order non-linear optical properties of amorphous GeSe2 film

The real and imaginary parts of third-order susceptibility of amorphous GeSe2 film were measured by the method of the femtosecond optical heterodyne detection of optical Kerr effect at 805 nm with the 80 fs ultra fast pulses. The results indicated that the values of real and imaginary parts were 8.8 x 10(-12) esu and -3.0 x 10(-12) esu, respectively. An amorphous GeSe2 film also showed a very fast response within 200 fs. The ultra fast response and large third-order non-linearity are attributed to the ultra fast distortion of the electron orbits surrounding the average positions of the nucleus of Ge and Se atoms. (c) 2005 Elsevier B.V. All rights reserved.

氮化镓紫外色度探测器及其制作方法

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黑土地区不同撂荒地植物生物量的季节变化

黑土地区处于北温带，冬季寒冷，夏季炎热;但由于纬度偏北，夏季日照时间较长.虽然黑土地区气候比较寒冷，但在生长季却是水、热、光同步，为植物的生长发育提供了良好的环境条件.因此黑土地区一直是中国主要的商品粮生产基地.但由于对土地掠夺式的开发，黑土在开垦后有机质含量急剧下降.植物生物量由地上生物量和根生物量组成.根生物量采用钻土芯法，地上生物量通过重复取样直接测定.研究表明：撂荒时间的增长，有助于植物生物量（包括地上生物量和根生物量）的积累，而尤以根生物量的增加最为明显;撂荒时间越长，在环境条件变化时，根生物量可以在生长季中保持相对的稳定;撂荒时间的增长，有助于植物营养元素碳、氮、磷的累积;撂荒时间越长，活根生物量的周转值越小.黑土地区不同撂荒年限植物生物量季节动态的研究还表明：不同年限撂荒地生物量的差异主要体现在根生物量的不同，地上生物量基本一致;即黑土开垦后土壤有机质急剧下降主要由根生物量归还减少导致;撂荒时间的增长，提高了生态系统适应环境的能力;植物营养元素碳、氮、磷的累积规律相似，而钾则与它们有较大差异.

AT91RM9200与Compact Flash接口电路及其驱动程序设计

介绍了基于ARM920T内核的AT91RM9200处理器与Compact Flash卡的接口电路以及Compact Flash卡驱动程序的编写、调试.提出了一种适合数据流量大、实时性能要求高的现场实时数据采集、事后PC机做分析处理的实时数据采集系统。

Optically active poly(amide-imide)s containing axially dissymmetric 1,1 '-binaphthyl moieties

Novel optically active aromatic poly(amide-imide)s (PAIs) were prepared from newly synthesized 2,2'-bis(3,4-dicarboxybenzamido)-1,1'-binaphyl dianhydride ((+/-)-, (S)-, and (R)-BNDADA). PAIs based on dianhydride monomers with different ee % were investigated with respect to their structures and chiroptical properties. These polymers were highly soluble in polar aprotic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, pyridine, etc., and showed high glas s transition temperatures of 287-290 degrees C and 5% weight loss temperatures of 450-465 degrees C in nitrogen. Optically active PAIs exhibited high specific rotations, excellent optical stabilities, and a dependence of optical activities on temperature. Investigations on chiroptical properties indicated that chiral conformation was possessed by optically active PAIs. (C) 1999 John Wiley & Sons, Inc.

Identification and expression of the amphioxus Cks1 gene

A full-length Cks1 homologue gene, AmphiCks1, was identified in amphioxus, Branchiostoma belcheri tsingtauense. Sequence characteristics, phylogeny and patterns of expression during embryonic and larval development were established. The protein predicted from AmphiCks1 showed high sequence identity with vertebrate and invertebrate homologues. Protein structural studies and phylogenetic analysis suggested that Cks homologues are evolutionarily conserved. The AmphiCks1 transcript was detected in most early developmental stages by northern blotting and whole-mount in situ hybridization, suggesting a role for the gene in cell division. (c) 2005 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.