m,m′-二氨基二苯酮与均苯四酸二酐的微波辐射聚合

研究 m,m′-二氨基二苯酮 (m,m′- DABP)与均苯四酸二酐 (PMDA)的缩聚及亚酰化 ,并运用微波辐射和常规加热两种方式对反应进行了比较。考察了微波辐射时间 (功率 )、单体浓度、单体配比和温度等因素对缩聚物的特性粘数、转化率的影响。用红外光谱对亚酰化度进行了表征 ,并用简并四波混频技术首次测量了该缩聚物的三阶光学非线性极化率系数及其响应时间。实验结果表明 ,微波辐射对提高聚合物的特性粘数和转化率都有显著作用 ;合成的缩聚物具有较大的三阶光学非线性极化率系数 (聚酰亚胺的 χ(3) =1.642× 10 -13 esu)和较快的时间响应 (19ps     

槽孔式水力驱动控制棒槽孔阻力系数实验研究

对槽孔式水力驱动控制棒槽对孔阻力系数进行了大量实验研究，获得了槽孔式水力驱动控制棒槽对孔阻力系数和其随槽对孔位移的变化规律，分析了槽对孔阻力系数与控制棒槽对孔结构参数之间的关系。结果表明：随槽对孔位移的增加，槽对孔阻力系数从某一较大的定值迅速降低到某一较小的定值，然后再迅速反回到初始的定值，形成一个对称的宽幅波谷；槽高使阻力系数曲线波谷幅宽发生变化，也使完全不重合段的阻力系数发生变化；随内套孔径的增大，阻力系数有所降低，其对阻力系数的影响也进一步减弱。孔径增大到一定程度，阻力系数基本不受孔径参数的影响。     

含预制分层损伤复合材料层合板在压缩载荷下破坏过程和剩余强度的模拟

本文运用一种具有较高精度的高阶位移模式,结合特定的损伤判据和刚度折减方法,建立了一种含损伤有限元模型,并利用其对多个含预制分层损伤的复合材料层合板在压缩载荷下的破坏过程进行了数值模拟,并最终得到这些层合板的剩余强度。与实验结果的对比表明,该数值模拟方法具有较高的精度和有效性。     

The Effect of the Charge Fluctuation of Dust Parti-cles on Ion-acoustic Wave Excited Through Ionization Instability

The effect of the charge fluctuation of dust particles on ion acoustic wave (IAW) excited through ionization instability was investigated. The hydrodynamic equations and linear time-dependent perturbation theory served as the starting point of theory, by which the dispersion relation and growth rate of the IAW were given. By comparing the results with the case of constant dust charges, it was found that the charge fluctuation of dust particles reduces the instability of the wave mode.     

Ion irradiation—induced structure damage to botanic samples using the ion transmission energy spectrum

1 INTRODUCTIONThe new aPplications of low energy heavy ion beam in irradi4ted botanical materialswere studied in recellt yeaxs. The beaminduced mutation effect on crop seeds has causedthe attention of physicist and biologists.[1l:] FOr examPle, 1ow energy ions can induceremarkable mutation to rice seeds.[3] There are many special phenomena when heavyions bombard botanic sW1e due to its special structure. Some studies showed that tllepenetration depths of some ions were far larger than t…     

The influence of dependence of HEMT’s model parameters on gate and drain voltages on upper boundary of LNA’s linearity

On the basis of numerical model the parameters of high electron mobility transistors (HEMT’s) as a function of gate and drain voltages are obtained. The simulation of nonlinear properties of low noise amplifier cascade with HEMT for various modes of its operation has shown that the account of its dependence simultaneously on both the voltages allows to approach the results of calculation to experimental data.     

对立堵截流难度的认识及其改善措施

 从立堵截流工程实践中,认识到影响截流难度的主要水力因素是截流落差Z、截流流量Q和截流水深h。结合葛洲坝工程、三峡工程等截流工程简要介绍了降低以上3个参数的一般措施。     

利用梯度方向信息的随机Hough变换

针对随机Ｈｏｕｇｈ变换（ＲＨＴ）在处理复杂图像随机采样造成的大量无效积累提出一种改进的用于直线检测的ＲＨＴ，较发地解决了无效果累积问题，并使改进后的算法具有计算速度更快，占用内存更少以及检测性能更好等优点。     

助剂对Pd/树脂醚化催化剂催化性能的影响 Ⅰ.铝助剂的影响

研究了不同助剂对Ｐｄ／树脂醚化催化剂在临氢条件下对催化裂化汽油Ｃ５馏份与甲醇和Ｈ２反应的催化性能的影响。结果表明，在Ｐｄ／树脂醚化催化剂中引入Ｚｒ、Ｔｉ、Ｂ、Ｓｎ和Ａｌ等助剂后，都能改善催化剂的醚化、双键异构和二烯烃选择性加氢活性，其中以Ａｌ、Ｓｎ为最好。Ａｌ助剂的体积质量和负载方式对Ｐｄ－Ａｌ／树脂醚化催化剂的活性有影响。ＢＥＴ方法和Ｘ－射线荧光光谱分析（ＸＦＳＡ）表明，Ａｌ助剂对Ｐｄ－Ａｌ／树脂醚化催化剂的表面积、孔结构和Ｐｄ离子交换量影响较小。     

大面积1.54μm波长测距用InGaAs雪崩光电二极管

设计并研制成功适合人的眼睛安全测距应用的ＩｎＧａＡｓ雪崩光电二极管（ＡＰＤ）。器件直径为２００μｍ，工作在２１℃，１５４０ｎｍ波长时响应为０．６４Ａ／Ｗ，典型暗电流和噪声因子分别为３０ｎＡ和６．５。介绍了该器件的工作原理，设计和制作工艺。