宁夏持续无虫灾防护林的结构设计

调查了宁夏新建二代防护林网主栽树种及辅栽乔、灌、草的生长表现和受害虫危害状况 ;列出了造林树种对主要害虫的抗性序列 ;将二代防护林网划分为 3个大类 ,每个大类又分为若干小类 ,并提出了各类防护林树种的选择。在以上研究的基础上提出无虫灾防护林树种的配置原则及设计方案。

An improved microtiter assay for evaluating anti-HIV-I neutralizing antibodies from sera or plasma

Background: The anti-HIV-1 neutralizing antibody assay is widely used in AIDS vaccine research and other experimental and clinical studies. The vital dye staining method applied in the detection of anti-HIV-1 neutralizing antibody has been used in many laboratories. However, the unknown factor(s) in sera or plasma affected cell growth and caused protection when the tested sera or plasma was continuously maintained in cell culture. In addition, the poor solubility of neutral red in medium (such as RPMI-1640) also limited the use of this assay. Methods: In this study, human T cell line C8166 was used as host cells, and 3-(4,5-Dimethyl-2-thiazolyl)- 2,5-diphenyl-2H-tetrazolium bromide (MTT) instead of neutral red was used as vital dye. In order to avoid the effect of the unknown factor( s), the tested sera or plasma was removed by a washout procedure after initial 3 - 6 h culture in the assay. Result: This new assay eliminated the effect of the tested sera or plasma on cell growth, improved the reliability of detection of anti-HIV-1 neutralizing antibody, and showed excellent agreement with the p24 antigen method. Conclusion: The results suggest that the improved assay is relatively simple, highly duplicable, cost-effective, and well reliable for evaluating anti-HIV-1 neutralizing antibodies from sera or plasma.

The development of a hot rolling process for variable cross-section I-beams

To meet targeted reductions in CO 2 emissions by 2050, demand for metal must be cut, for example through the use of lightweight technologies. However, the efficient production of weight optimized components often requires new, more flexible forming processes. In this paper, a novel hot rolling process is presented for forming I-beams with variable cross-section, which are lighter than prismatic alternatives. First, the new process concept is presented and described. A detailed computational and experimental analysis is then conducted into the capabilities of the process. Results show that the process is capable of producing defect free I-beams with variations in web depth of 30-50%. A full analysis of the process then indicates the likely failure modes, and identifies a safe operating window. Finally, the implications of these results for producing lightweight beams are discussed. © 2012 Elsevier B.V. All rights reserved.

PFU微型生物群落采样法研究有机氯污染物在水中相间分布

运用PFU微型生物群落采样法在武汉东湖取样研究了六六六、滴滴涕、六氯苯等有机氯污染物在水中相间分布。将PFU(Polyurethanefoamunit)取样得到的挤出液 ,经细胞固定、超声、消解及分步萃取等不同的预处理步骤后 ,用GC ECD测定了各部分提取物中α HCH、β HCH、γ HCH、δ HCH、HCB、pp′ DDE等有机氯污染物的浓度。并用四膜虫模拟试验检验了细胞固定化、消解过程对微型生物的作用效果。结果分析表明 ,以上有机物主要以微型生物富集或颗粒物强吸附形式存在于水中 ,颗粒物弱吸附形

Fluid-structure interaction simulations of a tension-cone inflatable aerodynamic decelerator

A series of fluid-structure interaction simulations of an aerodynamic tension-cone supersonic decelerator prototype intended for large mass payload deployment in planetary explorations are discussed. The fluid-structure interaction computations combine large deformation analysis of thin shells with large-eddy simulation of compressible turbulent flows using a loosely coupled approach to enable quantification of the dynamics of the vehicle. The simulation results are compared with experiments carried out at the NASA Glenn Research Center. Reasonably good agreement between the simulations and the experiment is observed throughout a deflation cycle. The simulations help to illuminate the details of the dynamic progressive buckling of the tension-cone decelerator that ultimately results in the collapse of the structure as the inflation pressure is decreased. Furthermore, the tension-cone decelerator exhibits a transient oscillatory behavior under impulsive loading that ultimately dies out. The frequency of these oscillations was determined to be related to the acoustic time scale in the compressed subsonic region between the bow shock and the structure. As shown, when the natural frequency of the structure and the frequency of the compressed subsonic region approximately match, the decelerator exhibits relatively large nonaxisymetric oscillations. The observed response appears to be a fluid-structure interaction resonance resulting from an acoustic chamber (pistonlike) mode exciting the structure. Copyright © 2013 by Christopher Porter, R. Mark Rennie, Eric J. Jumper.

可信计算环境证明方法研究

首先分析了可信计算环境下多远程证明实例执行的动态性、并发性、一致性等问题，提出了一个完整的可信计算环境多远程证明实例动态更新证明方案，以保证通信双方终端计算环境的可信。然后阐述了主要由计算环境组件度量算法、会话组件树计算算法和多远程证明实例证明协议组成可信计算环境证明方法。最后对该证明方法的安全性和效率进行分析，并构建原型系统论证证明方案的可行性和高性能。

高阶布拉格光栅在SOI脊形波导上的光刻制作

在SOI脊形波导上通过光刻的方法制作了高阶布拉格光栅.采用顶层Si厚为2μm的SOI基片,通过半导体芯片制备中的光刻工艺,在脊高为935 nm,波导宽度为2μm的脊形波导上,分别制作了刻蚀深度为565 nm和935 nm的起伏型高阶布拉格光栅,测试表明,在1540～1640 nm波长范围内,得到了大于10 dB的消光比,实现了高阶布拉格光栅在SOI脊形波导上的滤波效果.理论和实验都证明了光栅刻蚀深度的增大将有利于增加高阶布拉格光栅的耦合系数,以及光栅周期数的增加会引起更大的光栅损耗.

高质量二维光子晶体结构刻蚀掩膜版的制作方法

结合制作光子晶体结构的具体要求,研究了电子束曝光得到的电子束胶上(GaAs衬底)随实验条件变化的图形.结果表明,胶的厚度、曝光剂量、显影/定影时间等参数对图形的质量有重要影响.通过合理优化这些参数,我们得到了高质量的掩膜图形.