黑叶菝葜中甾体皂甙成分研究

从黑叶菝葜根中首次分得５个甾体甙和１个酚甙，采用化学方法和光谱技术鉴定其结构分别为：熊果甙（Ⅰ），胡萝卜甙（Ⅱ），薯蓣皂甙元－３－Ｏ－［α－Ｌ－鼠李吡喃糖基（１－４）］－β－Ｄ－葡萄吡喃糖甙（Ⅲ），薯蓣皂甙元－３－Ｏ－［α－Ｌ－鼠李吡喃糖基（１－２）］－β－Ｄ－葡萄吡喃糖甙（Ⅳ），薯蓣皂甙（Ⅴ）和孕甾－５，１６－二烯－３β－醇－２０－酮－３－Ｏ－［α－Ｌ－鼠李吡喃糖基（１－２）］［α－Ｌ－鼠李吡喃     

葡萄糖氧化酶的膜透析发酵工艺研究

用膜透析法可减缓发酵过程中代谢物对葡萄糖氧化酶生物合成的阻遏作用。初步研究结果表明，带膜透析的发酵其产酶速率比对照（不带透析的发酵）高一倍，总产量提高３０－５０％。膜发酵过程中ＰＨ、ＮＨ２－Ｎ的变化较对照平缓。对透析条件也作了初步摸索。     

矿井涌水量的逐步回归分析与预报

应用逐步回归分析的思想，在分析、计算大量数据的基础上揭示了矿井涌水量、钻孔涌水量或水位埋深与大气降水量、河流量之间的相关关系，并将这一关系的表示公式化，使以往为查清水体之间关系进行的繁杂分析试验等过程得以简化，且为水量或水位预报提供了简便易行的方法。     

Reduced cell death by inosine pretreatment after photochemically-induced cerebral ischemia in adult rats

Protective effect of inosine against cell death after photochemically induced focal cerebral ischemia was investigated in adult rats. Intraperitoneal injection of inosine was started 24 h before operation and continued till the animals were sacrificed. The TUNEL method and Nissl staining were used to identify apoptosis and necrosis, respectively. TUNEL-positive cells were located in the transitional zone between the necrotic core and normal cortex. The mean maximum area of the necrotic cores and mean number of TUNEL-positive cells 24 h after operation were reduced significantly in the inosine-treated rats when compared with those in the saline-treated control animals. We suggest that inosine can significantly reduce both necrosis and apoptosis following cerebral ischemia induced by photothrombosis in adult rats.     

高压喷射雾化液滴的二次破碎机理

采用射流界面不稳定扰动波雾化分裂理论,分析了单液滴在空气中以极高的速度运动过程中,由于液滴所受内外作用力的不平衡边界条件所产生的表面扰动;建立了液滴二次破碎色散方程,给出了单液滴在扰动波作用下发生二次破碎的最快增长率和相应的最不稳定波长,以及破碎时间和稳定液滴直径;分析了液体粘性、液滴速度对高速运动液滴不稳定性的影响,对液滴雾化机理进行了理论探讨.仿真表明:由作用于高速运动液滴表面的不平衡力,使得液滴界面产生变形加速度,这是导致液滴表面不稳定而进一步分裂的内在动因;粘性对扰动波发展有抑制作用,气液界面运动加速度是控制液滴破碎的重要因素.     

一种新的宽带波束形成算法

基于对角加载思想,针对宽带信号空时处理结构,将空时接收协方差矩阵进行特征值分解,并利用矩阵求逆定理推导出空时结构对角加载值的范围,得到空时结构对角加载波束形成算法的优化方程以及最优权向量的解.仿真结果表明,算法有效地对协方差矩阵估计进行了修正,增强了空时波束形成算法的鲁棒性.     

Environmental changes reflected by n-alkanes of lake core in Nam Co on the Tibetan Plateau since 8.4 kaB.P.

The n-alkanes are extracted from NMLC-1 core that was drilled in the Nam Co, central Tibet. They are measured by using Gas Chromatography and Mass Spectrometry （GC/MS） for componential and quantitative analyses. According to the constructed depth-age model, the component and concentration of n-alkanes, together with total organic carbon （TOC）, total nitrogen （TN） and carbonate are used to elucidate palaeoenvironmental changes of Nam Co during the past 8.4 ka. The results indicate that Holocene environment performs three stages in the lake area. In the stage of 8.4-6.7 kaB.P., it was warmer while precipitation slightly increased. This stage was ended by an obvious cold/dry event. During 6.7-5.8 kaB.P., temperature increased rapidly and reached its maximum values at about 6.0 kaB.P. The environments were warm/wet optimum for the blooming of terrestrial plants and submerged aquatic plants. After that, temperature decreased continuously and showed the lowest values at about 3.0 kaB.P. From 2.9 kaB.P, to the present, temperature rose again but alternated with cold and warm. The lake area tended to be dry after 1.4 kaB.P. During 600-400 aB.P., the environmental feature was the reflection of ＂Little Ice Age＂.     

An in-situ DRIFTS study in the reaction between NO x and soot on BaAl2O4

The interactions between NO, O2 and their mixture on BaAl2O4, as well as the reaction of NOx with soot in the presence of O2, have been investigated using Diffuse Reflectance Infrared Fourier Transform Spectroscopy （DRIFTS）. NO adsorption produces only nitrites species in the absence of O2. NO2 adsorption produces nitrates species besides nitrites species. The produced nitrites will further react with O2, Osurf^-. and Olattice^2- to form nitrates. The reaction of NOx with soot begins with the reaction of nitrates with soot oxygenated complex （C（O））, which is regarded as the key and rate determining step. A reaction pathway is proposed for the catalyzed reaction of NOx with soot in the presence of O2.     

多层框架结构区间优化新方法

多层框架结构的设计参数受测量或加工精度影响往往具有一定的误差或不确定性.针对设计参数具有不确定性的多层框架结构,提出一种区间优化新方法.用区间数表征框架结构的不确定设计参数,通过优化框架结构响应区间值的上界,将区间优化问题转化为近似的确定性优化问题.将结构响应Taylor展开式中的一阶导数也看成区间的,可得到框架结构响应更加准确的变化范围. 选择区间设计参数的中值和半径为优化变量,可以得到比传统确定性结构优化更多的优化信息.对一典型四层框架结构进行了具有频率约束的区间优化.结果表明,区间优化不仅能得到与传统结构优化大致相同的设计参数最优值,还能得到当实际工程问题中设计参数取不到理论最优值而有微小波动时,框架结构响应的变化范围,为框架结构的可靠性分析提供理论依据.     

重频系统的频率灵敏度分析算法研究

针对重频系统提出了计算其频率灵敏度的精确方法.首先提出了相容性条件方程的概念;其次对单频系统,利用其相容性条件方程,确定了所有单频的灵敏度算法,并指出了该算法与已有结论的等价性;然后对重频系统,为了克服其左、右状态向量正交性的退化现象,特别引入了右状态向量的伴随向量来实现解耦功能,同样利用其相容性条件方程,获得了所有重复频率的灵敏度的显式解法.该算法推导过程易于理解,适用于各种重分析过程,结论简洁紧凑易于编程实现.最后以2个具有重复频率的非比例阻尼振动系统作为算例,说明了该算法的正确性及有效性,并验证了所提出的灵敏度系数控制方程的相容性.