配液结晶法制备溶菌酶蛋白质晶体的生长机理研究

采用配液结晶法制取了溶菌酶蛋白质晶体,使用动态光散射测量了溶液中聚集体的颗粒度几率分布;使用Zeiss显微镜测定了溶菌酶(110)晶面的生长速度.实验表明:随着蛋白质和NaCl浓度的增加,溶液中聚集体的颗粒尺寸也相应增加.随着反应时间的增加,溶菌酶分子在溶液中的聚集反应,逐渐达到平衡;在蛋白质和NaCl浓度较高时,溶菌酶晶体的(110)面生长较快,而在蛋白质和NaCl浓度较低时,该晶面生长较慢.基于二维成核生长机理,从晶体生长动力学理论方程出发,计算了二维成核的形成能a=4.01×10-8J?cm-2.

Influence of Electrostatic Interaction on Fibrinogen Adsorption on Gold Studied by Imaging Ellipsometry Combined with Electrochemical Methods

Imaging ellipsometry was combined with electrochemical methods for studying electrostatic interactions of protein and solid surfaces. The potential of zero charge for gold-coated silicon wafer/solution interfaces wad determined by AC impedance method. The potential of the gold-coated silicon wafer was controlled at the potential of zero charge, and the adsorption of fibrinogen on the potential-controlled and non-controlled surfaces was measured in real time at the same time by imaging ellipsometry The effect of electrostatic interaction was studied by comparing the difference between the potential of controlled adsorption and the Potential of noncontrolled adsorption. It was shown that the rate of fibrinogen adsorption on the potentiostatic surface was faster than that on the nonpotentiostatic surface. The electrostatic influence on fibrinogen adsorption on the gold-coated silicon wafer was weak, so the hydrophobic interaction should be the major affinity.

On the influence zone and the prediction of tensile strength of particulate polymeric composites

An intended numerical investigation is carried out. The results indicate that, even if a perfect adhesive bond is preserved between the particles and matrix materials, the two-phase element cell model is unable to predict the strength increment of the particulate polymeric composites (PPC). To explore the main reinforcing mechanism, additional microscopic experiment is performed. An ''influence zone'' was observed around each particle which is measured about 2 to 10 micrometers in thickness for a glass-polyethylene mixture. Then, an improved computational model is presented to include the ''influence zone'' effect and several mechanical behaviors of PPC are well simulated through this new model.

参变过程中的群速延迟对晶体匹配长度的影响

基于能量守恒和三波耦合波方程, 建立了超短脉冲在参变过程中二次谐波产生时的I类和II类相位匹配条件、基波与谐波之间的群速延迟时间、以及群速失配对晶体长度限制的理论基础。以负单轴非线性光学晶体CsLiB6O10为例, 分析和数值计算了超短脉冲宽度为100 fs时, 谐波的群速匹配长度随基波波长变化的规律。研究结果表明在I类相位匹配条件下, 基波波长为642 nm时, 群速延迟最小, 相应的群速匹配晶体长度最长为19.1 mm;在II类相位匹配条件下, 基波波长为767 nm, 群速延迟最小, 群速匹配长度最

Fuzzy inferring mathematical morphology and optical implementation

Fuzzification is introduced into gray-scale mathematical morphology by using two-input one-output fuzzy rule-based inference systems. The fuzzy inferring dilation or erosion is defined from the approximate reasoning of the two consequences of a dilation or an erosion and an extended rank-order operation. The fuzzy inference systems with numbers of rules and fuzzy membership functions are further reduced to a simple fuzzy system formulated by only an exponential two-input one-output function. Such a one-function fuzzy inference system is able to approach complex fuzzy inference systems by using two specified parameters within it-a proportion to characterize the fuzzy degree and an exponent to depict the nonlinearity in the inferring. The proposed fuzzy inferring morphological operators tend to keep the object details comparable to the structuring element and to smooth the conventional morphological operations. Based on digital area coding of a gray-scale image, incoherently optical correlation for neighboring connection, and optical thresholding for rank-order operations, a fuzzy inference system can be realized optically in parallel. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

部分端面抽运板条激光器腔镜倾斜问题研究

部分端面抽运的板条激光器是一种新型固体激光器．配合混合腔可以实现在大功率下保持高光束质量的激光振荡输出。谐振腔的腔镜倾斜是影响激光器输出特性的重要因素，快速傅里叶方法是一种快捷有效的计算方法，利用此方法模拟了腔镜倾斜对近场相位分布和远场光强分布的影响，并分析了光束质量的变化。理论分析表明，腔镜的小角度倾斜对近场相位影响较大，但对远场光强空间分布影响不大；随着倾斜角度不断增大，远场发散角和光束腰宽度也增大，光束质量虽然存在恶化的趋势，但光束质量因子肝值仍然较小，离轴非稳腔仍能保持高光束质量的输出。

Gain characteristics of Er3+-doped phosphate glass fibres

An erbium-doped phosphate glass fibre has been drawn by the rod-in-tube technique in our laboratory. The gain for the Er3+-doped phosphate glass fibre with different pump powers and with different input signal wavelengths is investigated. The 2.2-cm-long fibre, pumped by a single-mode 980-nm fibre-pigtailed laser diode, can provide a net gain per unit length greater than 1.8dB/cm. The pump threshold is about 50 mW at the wavelength of 1534 nm, and below 70 mW at 1550 nm. The gain linewidth of the Er3+-doped phosphate glass fibre is greater than 34 nm and can cover the C band in optical communication networks.

Gain and noise figure of a double-pass waveguide amplifier based on Er/Yb-doped phosphate glass

A waveguide amplifier is fabricated by Ag+-Na+ two-step ion exchange on Er/Yb-doped phosphate glass. The spectroscopic performance of glass and the properties of channel waveguide are characterized. A double-pass configuration is adopted to measure the gain and noise figure (NF) of the waveguide amplifier, and the comparison of gain and NF for the single and double-pass configuration of the waveguide amplifier is presented. The results show that the double-pass configuration can make the gain increase from 8.8dB (net gain 2.2dB/cm) of the single-pass one to 14.6 dB (net gain 3.65 dB/cm) for small input power at 1534 nm, and the NF are all lower than 5.5dB for both the configurations.

贵州绵羊线粒体DNA (m tDNA ) 多态性研究

采用15 种限制性内切酶对贵州威宁绵羊和六盘水绵羊各5 只个体的m tD2 NA 多态性进行研究。其中只有BamHÉ 一种酶的酶切类型表现多态, 产生三种酶切 类型。共得到17 种限制性态型, 可归结为三种m tDNA 单倍型, 在威宁绵羊中单倍 型É 所占比较较大(80% ) , 单倍型Ë 只占20% , 而在六盘水绵羊中则单倍型É 和Ê 所占比例相当; 根据单倍型在群体中的分布和单倍型间遗传距离, 推测贵州绵羊的 m tDNA 单倍型É 和Ê 可能代表两个母系祖先的基本单倍型, 其分化时间约有16～ 32 万年之久, 单倍型Ë 则可能是由单倍型É 随机突变而来; 两个地方绵羊群体间的 分化时间大约为613～ 1216 万年, 群体间的m tDNA 遗传多态度较低, 但六盘水绵羊 群体内遗传多态度比威宁绵羊较丰富。

作物及热带作物病虫害数据库的研制和建立

通用的“作物病虫害数据库管理系统（ＰＥＳＴＢＡＳＥ２．１）”和用此系统建立的“热带作物病虫害数据库管理系统”的主要信息项有：各种寄主作物的种类、种植利用，各种病虫的分类地位、地理分布、检疫情况、生物学特性、危害症状、发生规律、天敌、防治方法和农药信息。所建热带作物病虫害数据库管理信息系统中已录用１０００余篇有关文献或专著中的相关信息，涉及的作物种类有：橡胶、咖啡、可可、胡椒、油棕、椰子、腰果、热带水果（芒果、荔枝、龙眼、菠萝、柑桔、油梨、木瓜等）、剑麻、槟榔、茶叶、木薯以及一些热带药用植物和热带花卉等４０余种热带作物；库中存入危害这些作物的病害４００余种、虫害近３００种、一些防治实例及农药信息。

空间飞行和辐射对微藻光合系统影响的观察

目的研究空间飞行及辐射对微藻光合系统的影响。方法利用卫星搭载空间飞行、钴60的γ射线照射及地面对照黑暗培养微藻葛仙米,测定其存活率、光合活性、光合系统色素及观察藻细胞超微结构。结果空间飞行和射线处理后的微藻其存活率、光合活性发生显著降低,捕光色素明显降解、光合片层结构出现异常,同时空间飞行后微藻细胞外诱导出较厚的胶被。结论空间飞行及辐射均对微藻的光合系统产生损伤,但微藻可以通过结构上的改变对其进行适应。

抗胸腺细胞抗体对中华鳖免疫系统的影响

国家自然科学基金(No.30070588;No.30371091)