动态油膜-转子系统的支座松动故障研究

采用张文等建立的短轴承非稳态非线性油膜力模型,利用数值模拟等方法,分析了带有一端支座松动故障的转子 轴承系统的复杂运动现象,讨论了转速比变化时此类系统中具有周期、拟周期、混沌等多种形式的运动·研究结果表明:当转子 轴承系统出现松动故障时,即便是在较高转速区也会出现周期3分频运动,而且,松动端轴颈的运动轨迹以及支座的相轨迹都呈现出特有的形状,这为有效识别转子 轴承系统的支座松动故障提供了理论参考·     

基于Stewart机床的一种新结构

该文在分析目前虚拟轴机床研究和开发现状的基础上，提出一种新结构的虚拟轴机床，对其结构特点和性能进行论述，并对其工作空间，平台偏转角，精度和力特性问题作分析。应用达朗贝尔原理和虚位移原理，分析机床机构的动力学问题，并建立动力学方程；应用修改的Gauss-Seidel迭代法，考虑活动平台作水平圆周运动情况，解出了动力学方程的数值解，并绘制了机构的滑块仿真曲线。     

水稻对硅、钾、钙、镁的吸收动力学研究

为了研究水稻对硅、钾、钙、镁的不同吸收效应，同时探索含钾硅酸盐矿物的肥料价值，本文采用了动力学研究方法．结果表明：水稻对硅、钾、钙、镁的吸收速率因肥料配比差异而不同；而施用多元复合物，水稻生长过程中对硅、钾、钙、镁的吸收速率明显增加；四个动力学方程对水稻吸收养分规律的拟合度都达到了极显著性或显著性水平；单从相关系数及其变异系数来看，四种养分的拟合情况均以Freybdkucg方程为最好．     

大范围运动空间梁的耦合动力学模型

从连续介质力学原理出发，对作大范围运动的空间梁建立耦合动力学模型．在纵向变形中计及了变形位移的二次耦合变形量，基于Jourdain速度变分原理导出作大范围运动的空间梁的动力学方程．将耦合动力学模型的仿真计算结果与不计二次耦合变形量传统的建模理论进行比较表明，在大范围运动的侧向角速度和浮动基基点的纵向加速度较大的情况下，二次耦合变形量对系统的刚—柔耦合动力学性质产生一定的影响．     

阔草清除草剂在玉米及土壤中残留动态研究

采用zorbaxSIL色谱柱、以二氯甲烷-甲醇为流动相的高效液相色谱法测定了阔草清除草剂在玉米田土壤、玉米籽粒和植株上的残留动态，建立了样品前处理方法和分析方法。阔草清在土壤、玉米籽粒、植株的添加回收率分别为88.00%～96.80%,90.30%～93.50%和84.20%～94.20%,阔草清在土壤中的半衰期（t1/2)吉林为12.1d。山东为20d，山东为20d，降解速度较慢；在植株中半衰期（t1/2)吉林为4.3h,山东为5.5h，降解较快。但在收获的土壤、玉米和植株中均未检出。说明其残留污染性很小，可以在玉米田安全使用。     

家蚕血液中微粒子Nosema bombycis种群增殖模型研究

为了进一步认识家蚕微粒子病在生产中的流行规律，提高防微工作的科学性，利用微生态学方法对家蚕微粒子进行了研究，通过对蚕体血液内子NosemaBombycis种群数量的动态分析，认识了NosemaBombycis孢子在蚕体血液内的增殖规律，为家蚕微粒子病的防治以及预测预报等工作提供科学的依据，从而指导生产实践，找出最优的防治方案及措施，力争把该病的危害控制在最低限度。     

麦弗逊悬架刚度对汽车稳态转向特性的影响

以多体系统动力学理论为基础，以某微型汽车为工程实例，建立了包含车架、转向系、前后悬架和差速器5大总成的某麦弗逊前悬架汽车稳态转向特性整车动力学分析模型，研究了螺旋弹簧刚度和横向稳定杆直径等悬架刚度参数对汽车稳态转向特性的影响规律。分析结果表明，增加前螺旋弹簧刚度和横向稳定杆直径能明显提高该车的稳态转向特性，但稳态转向特性得分值增量却逐渐下降。因此，合理选择前悬架刚度参数是提高麦弗逊前悬架汽车稳态转向特性的有效途径。     

Cryptomelane（KxMn8-xO16）： Natural active octahedral molecular sieve（OMS-2）

The Xiangtan manganese deposit (XTM) used to be considered a supergene oxide manganese ore in South China. We reported a new identification of the naturally outcropping cryptomelane by examining the physical, chemical and structural features of the XTM supergene oxide manganese ore. The MnO2 content was over 90%, K2O more than 3%, and water from 2.2%-3.1% which is similar to one in zeolite. The cell parameters of the cryptomelane were given as a0 = 0.9974 nm, b0 = 0.2863 nm, c0 = 0.9693 nm and β= 91.47°. There was a larger pseduotetragonal tunnel in the natural cryptomelane that was formed by [MnO6] octahedral double chains with aperture of 0.462×0.466 nm2, filled with K cations resulting in some Mn3+ substituting for Mn4+ to balance the negative charges of structure. The finding is important not only for prospecting manganese resources in South China, but also in application of octahedral molecular sieve of natural cryptomelane as that developed in the tetragonal molecular sieve of natural zeolite o     

Initial organic geochemical investigation on Late Neoproterozoic-Early Cambrian sediments in the Yangtze region, China

Totally 19 samples of typical Upper Proterozoic-Lower Cambrian sedimentary rocks were collected and analyzed for an organic geochemical investigation. Almost all these rocks have high TOCs, super-maturities and similar biomarker distribution. As an exception, however, the Sinian Nantuo Tillite shows much lower TOCs and little phytane and pristane in comparison with those in other strata, which implies a very faint photosynthetic process, and a restricted euphotic zone and quite limited sunlight within the sedimentary water column during the Sinian glaciation age in the western Yangtze region providing an evidence for palaeo-oceanic environment of the Neoproterozoic Snowball Earth age.     

Design and application of 60mer oligonucleotide microarray in SARS coronavirus detection

In April 2003, a novel coronavirus[1,2] which was associated with cases of Severe Acute Respiratory Syn-drome (SARS) was first isolated and sequenced in Canada. The genome of SARS coronavirus (SARS-CoV) is 29727[3] nucleotides in length and has 11 known open reading frames (ORFs). Although the genome organiza-tion of this virus is similar to that of other coronaviruses, phylogenetic analyses and sequence alignment show that SARS-CoV is not closely related to any of the previously ch…