硝基芳香族炸药的分子结构和撞击感度关系研究

计算并分析了18个三硝基芳香族炸药分子的原子化能以及原子化能与分子的电子结构能的比值与撞击感度的关联关系,进一步确证二级炸药分子结构性质与其撞击感度之间的相关性.结果发现分子的原子化能与撞击感度之间没有关联关系,而其原子化能与分子结构能的比值与撞击感度之间存在非常明显的线性相关性,而且分子结构的化学分类以及结构的对称性对这种关联关系有显著影响.同时进一步把研究结果与相关的文献进行分析比较,发现原子化能与分子结构能的比值与撞击感度之间存在线性相关性,这种相关性与大量文献报道的炸药分子最弱键的键离解能与撞击感度的相关性在理论意义上是可以相提并论的,前者对于问题的分析更显具体和细致.     

Reduced function and disassembled microtubules of cultured cardiomyocytes in spaceflight

Lack of gravity during spaceflight has profound effects on cardiovascular system, but little is known about how the cardiomyocytes respond to microgravity. In the present study, the effects of spaceflight on the structure and function of cultured cardiomyocytes were reported. The primary cultures of neonatal rat cardiomyocytes were carried on Shenzhou-6 spacecraft and activated at 4 h in orbit. 8 samples were fixed respectively at 4, 48 and 96 h after launching for immunofluorescence of cytoskeleton, and 2 samples remained unfixed to analyze contractile and secretory functions of the cultures. Ground samples were treated in our laboratory in parallel. After 115 h spaceflight, video recordings displayed that the number of spontaneous beating sites in flown samples decreased significantly, and the cells in the beating aggregate contracted in fast frequency without synchrony. Radioimmunoassay of the medium showed that the atrial natriuretic peptide secreted from flown cells reduced by 59.6%. Confocal images demonstrated the time-dependant disassembly of mirotubules versus unchanged distribution and organization of microfilaments. In conclusion, above results indicate reduced function and disorganized cytoskeleton of cardiomyocytes in spaceflight, which might provide some cellular basis for further investigations to probe into the mechanisms underlying space cardiovascular dysfunction.     

高校残障学生锻炼指导的研究

对高校残障学生体育锻炼、健康指导情况进行了调查、分析和评述,目的是增强残障大学生体质,提高心理健康水平,倡导体育人文关怀,促进和谐校园建设.     

大学图书馆创新发展之我见

随着信息技术的进步,大学图书馆必须实现管理与服务模式的转变,馆藏图书要随着学科、专业建设的发展而更新,使师生在教学、科研工作中接受最新的信息资源、接受到最新的社会动向,和社会保持同步前进。     

Fast computation of scattering from 3D complex structures by MLFMA

This paper introduces the research work on the extension of multilevel fast multipole algorithm （MLFMA） to 3D complex structures including coating object, thin dielectric sheet, composite dielectric and conductor, cavity. The impedance boundary condition is used for scattering from the object coated by thin lossy material. Instead of volume integral equation, surface integral equation is applied in case of thin dielectric sheet through resistive sheet boundary condition. To realize the fast computation of scattering from composite homogeneous dielectric and conductor, the surface integral equation based on equivalence principle is used. Compared with the traditional volume integral equation, the surface integral equation reduces greatly the number of unknowns. To computc conducting cavity with electrically large aperture, an electric field integral equation is applied. Some numerical results are given to demonstrate the validity and accuracy of the present methods.     

On the MIMO channel capacity saturation for spatially constrained receive region

In MIMO wireless communication systems,when more and more antennas are packed into spatiallylimited receive region,the antenna saturation phenomenon will appear.Moreover,the electromagnetic interactions among antennas will also become stronger and stronger and affect the antenna saturation effect considerably.Despite this,few studies consider these two effects jointly.The effects of antenna saturation are investigated under the consideration of mutual coupling,thus a more practical and physically meaningful result can be obtained.     

Surface nanostructures orienting self-protection of an orthodontic nickel-titanium shape memory alloys wire

Shape memory alloys (SMA) have been applied to a wide variety of applications in a number of different fields such as aeronautical applications, sensors/actuators, medical sciences as well as orthodontics. It is a hot topic to enhance the anti-corrosion ability of orthodontic wires for clinical applications. In this letter, a very nice fractal structure, micro-domains with identical nanometer sized grooves, was ob- tained on the surfaces of the orthodontic wires with an oxygen plasma and acid corrosion. The concave parts of the grooves were dominated by titanium and convex parts were the same as the bulk wires. The micro-nano fractal structure generated a hydrophobic surface with the largest contact angle to water being about 157°. The titanium dominated nanolayer and the hydrophobicity of the surface resulted in jointly the great improvement of the anti-corrosion ability of the orthodontic wires. Because the fractal structures of the wires were formed automatically when they immersed in acidic environment, hence, the self-protection of the oxygen plasma-treated orthodontic wires in acidic environment indicates their potential applications in orthodontics, and should be also inspirable for other applications of SMA materials.     

数字全息中直透光和共轭像的去除方法

去除直透光和共轭像的影响,提高全息再现像的质量,一直以来都是全息研究中的一个热点和难点,已有许多结合数字图像处理技术方法被提出.针对数字全息中直透光和共轭像的去除方法进行综述,说明各方法的优点、不足及其适用情况,并通过实验加以验证.     

三价砷存在条件下毒砂表面微结构对热氧化硫杆菌附着性的影响

Understanding bacterial adsorption and the evolution of biofilms on arsenopyrite with different surface structures is of great significance to clarifying the mechanism of microbe–mineral interfacial interactions and the production of acidic mine drainage impacting the environment. In this study, the attachment of Sulfobacillus thermosulfidooxidans cells and subsequent biofilm formation on arsenopyrite with different surface structures in the presence of dissolved As(Ⅲ) was studied. Arsenopyrite slices with a specific surface were obtained by electrochemical corrosion at 0.26 V. The scanning electronic microscopy-energy dispersion spectra analyses indicated that the arsenopyrite surface deficient in sulfur and iron obtained by electrochemical treatment was not favorable for the initial adsorption of bacteria, and the addition of As(Ⅲ) inhibited the adsorption of microbial cells. Epifluorescence microscopy showed that the number of cells attaching to the arsenopyrite surface increased with time; however, biofilm formation was delayed significantly when As(Ⅲ) was added.     

A content aware chunking scheme for data de-duplication in archival storage systems

Based on variable sized chunking,this paper proposes a content aware chunking scheme,called CAC,that does not assume fully random file contents,but tonsiders the characteristics of the file types.CAC u...