海洋平台用高强度钢多层补焊的疲劳分析

对海洋平台用高强度钢焊接接头多次补焊的疲劳性能进行试验研究，给出采用威布尔分布下的寿命估算式及R-S-N曲线。考虑到多次补焊后焊趾外移造成的焊接角的变化，应用有限元方法计算试样的应力分布，给出焊趾处的应力集中系数，由此进一步分析多次补焊对焊接接头疲劳性能的影响。

The Hydrothermal Wave Of Large-Prandtl-Number Fluid In A Shallow Cavity

The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied temperature difference grows and over the critical value. The phase relationships of the disturbed velocity, temperature and pressure demonstrate that the traveling wave is driven by the disturbed temperature, which is named hydrothermal wave. The hydrothermal wave is so weak that the oscillatory flow field and temperature distribution can hardly be observed in the liquid layer. The exciting mechanism of hydrothermal wave is analyzed and discussed in the present paper.

Basic equations for ferroelectrics

A set of new formula of energy functions for ferroelectrics was proposed, and then the new basic equations were derived in this paper. The finite element formulation based on the new basic equations was improved to avoid the equivalent nodal load produced by remnant polarization. With regard to the fundamentals of mathematics and physics, the new energy functions and basic equations are reasonable for the material element of ferroelectrics in finite element analysis.

光系统Ⅱ的非均匀性

以去垢剂Triton X—100 增溶莴苣、大豆和菠莱叶绿体，得到具有较高放氧活性的光系统Ⅱ（PSⅡ）颗粒。放氧活性在200~250u mol 02 ∕mgchl∙ hr,而光系统I活性很低。 对此颗粒进行了光诱导荧光动力学分析，表明在这三种植物的PSⅡ颗粒中仍存在着两个动力学相，即快速的、非指数型上升α相，和慢速的、指数型上升β相。并和其来源的叶绿体作了比较。 将ATP在光照和镁离子存在下与PSⅡ颗粒共同进行保温后，PSⅡ颗粒的荧光动力学参数发生了变化，α相含量降低，但去磷酸化可部分恢复。77K荧光发射光谱表明，保温后F685/F695比值降低了，去磷酸化也可部分恢复。 本文结合这些现象作了讨论。认为两类中心理论中关于α、β中心在膜上分区的假设是值得商榷的;动力学两相的存在无需以蛋白质分布横向非均匀性为前提条件，两类中心的模型在上述现象解释中不是令人满意的。

超微量汞元素气相热色谱分离装置

本实用新型主要涉及超微量元素的分离装置，尤其涉及超微量汞元素气相热色谱分离装置。一种超微量元素气相热色谱分离装置，包括有外壳，真空泵，其主要特点是还包括有靶炉，其内设有放置铅靶片的石墨盒、测量热电偶；靶炉与长传输管相通，其上设有测量热电偶；长传输管上设有测量热电偶，其末端设有收集器及制冷装置。本实用新型对超微量汞元素（即被分离的元素原子数与可融化的金属块载体原子数的比在１∶１０↑［１６］至１∶１０↑［１２］之间）的高灵敏度、高效气相热色谱分离。特别适合于放射性汞的分离和收集，具有快速、高灵敏、高效的特点。

中国胭脂鱼线粒体控制区遗传多样性分析

利用PCR技术扩增了采自长江宜昌江段和清江的 8尾中国胭脂鱼线粒体DNA控制区全序列。研究发现该种具有脊椎动物线粒体控制区的一般结构 .在获得的 95 8bp的碱基序列中 ,共检测出 32个多态性核苷酸变异位点 ,多态位点比例为 0 .0 33。核苷酸的变异位点除一个为缺失外 ,其余全部为碱基转换 .变异位点主要集中在 5 5～36 5bp高变异区 ,而其他区域突变稀少。个体的变异在 0～ 1.36 %之间 ,表现出较大的个体多态性差异。中国胭脂鱼的线粒体控制区的变异远大于美国胭脂鱼 (Moxostoma

Endocrine disrupting effects on Chinese rare minnow (Gobiocypris rarus) fed with field collected Limnodrilus sp.

The potential endocrine disrupting effects and other toxicity effects on aquatic biota resulted from food uptake was simulated by feeding the laboratory cultured rare minnow(Gobiocypris rarus) with field collected Limnodrilus sp. The results indicated that the food chain processes affected significantly the growth, slightly reduced gonadosomatic indices, and elevated hepatosomatic indices. There was an obvious vitellogenin(VTG) induction, which generally only occurred in mature female, in the serum of juvenile rare minnow and mature male when fed with Limnodrilus sp. In addition, the rare minnow feeding on Limnodrilus sp. had significantly high renal indices, it meant obvious renal hyperplasia. The present work suggested that. Limnodrilus sp. from field water may contain toxic pollutants and could lead to endocrine disruption effects to the predators. It was concluded that endocrine disruptors may not only be assimilated through water, but also be bioconcentrated through food web. The results also suggested the importance of food selection in conducting the study of endocrine disruption effects using sensitive species.

A column method for determination of soil organic partition coefficients of eight pesticides

A column method was developed to conveniently and reliably determine the soil organic partition coefficients (K-oc) of three insecticides (methiocarb, azinphos-methyl, fenthion), four fungicides (triadimenol, fuberidazole, tebuconazole, pencycuron), and one herbicide (atrazine), in which real soil acted as a stationary phase and the water solution of pesticide as an eluent. The processes of sorption equilibrium were directly shown through a breakthrough curve(BTC). The log K-oc values are 1.69, 1.95, 2.25, 2.55, 2.69, 2.67, 3.10, and 3.33 for atrazine, triadimenol, methiocarb, fuberidazole, azinphos-methyl, tebuconazole, fenthion and pencycuron, respectively.

Chirp-free optical modulation using a silicon push-pull coupling microring

We propose a silicon ring-based optical modulation method to perform chirp-free optical modulations. In this scheme, we locate the light to be modulated at the resonance of the ring and tune the coupling coefficient between the ring and the straight waveguide by using a push-pull coupling structure. The chirp-free phase modulation can be achieved by varying the coupling coefficient in a large range, which can modify the coupling condition of the ring such that the input light experiences an abrupt phase shift of pi at the output. If the coupling coefficient is adjusted in a small range such that the coupling condition of the ring is kept unchanged, only the intensity of the light will be modulated. This leads to chirp-free intensity modulation. Our simulations performed at 10 Gbits/s confirm the feasibility of the proposal. (C) 2009 Optical Society of America