爆炸夯实法密实水下填砂地基的工程试验

深圳妈湾电厂排水涵填砂基础采用工程试验的方式用爆夯法进行密实处理，试验的基本参数主要根据力学所砂基密实研究及应用方面取得的成果确定，据此试验首先检验出砂基处于较为松散状态，然后用相同的爆炸参数成功地密实了排水涵基础，解决了妈湾电厂施工中的难题。

钝锥高超声速边界层来流感受性数值研究

应用作者所建立的高精度非定常激波装配法,数值模拟了高超声速条件下,钝锥绕流快声波来流扰动非定常流场,研究了钝锥超声速边界层对来流扰动感受性特征,研究表明,在各种来流扰动的条件下,钝锥边界层感受到的主要是声波扰动;钝锥边界层内扰动模态,在头部附近是第一模态,向下游依次转换为第二模态、第三模态;另外随钝度减小,边界层内扰动模态的振幅增大,但有一临界值,超过临界后反而减小,并且由于曲率间断的影响,模态振幅随钝度的变化不再是单调变化的.

非传播孤立波及其相互作用的数值模拟

通过数值求解由Miles导出的目前公认的非传播孤立波的控制方程——一个带复共轭项的非线性立方Schr〖AKo¨〗dinger方程,对非传播孤立波进行研究.讨论了Miles方程中的线性阻尼系数α的值,模拟了两个非传播孤立波的相互作用,数值模拟表明,两个波的作用模式依赖于系统的参数,对不同的初始扰动及其演化的计算表明,只有适当的初始扰动才能形成单个稳定的非传播孤立波,否则扰动可能消失或发展成多个孤立波.

In Situ Synthesis of Nanocrystalline Intermetallic Compound Layer During Surface Mechanical Attrition Treatment of Zirconium

The surface mechanical attrition treatment (SMAT) technique was developed to synthesize a nanocrystalline (NC) layer on the surface of metallic materials for upgrading their overall properties and performance. In this paper, by means of SMAT to a pure zirconium plate at the room temperature, repetitive multidirectional peening of steel shots (composition (wt%): 1C, 1.5Cr, base Fe) severely deformed the surface layer. A NC surface layer consisting of the intermetallic compound FeCr was fabricated on the surface of the zirconium. The microstructure characterization of the surface layer was performed by using X-ray diffraction analysis, optical microscopy, scanning and transmission electron microscopy observations. The NC surface layer was about 25 mu m thick and consisted of the intermetallic compound FeCr with an average grain size of 25 +/- 10 nm. The deformation-induced fast diffusion of Fe and Cr from the steel shots into Zr occurred during SMAT, leading to the formation of intermetallic compound. In addition, the NC surface layer exhibited an ultrahigh nanohardness of 10.2 GPa.

双程掺镱光纤放大器的增益特征及优化

比较了掺钕光纤和掺镱光纤对1064nm光放大的特点．基于速率方程和传输方程，数值分析了在915nm泵浦下双程掺镱光纤放大器的增益特征，并且和传统的单程放大进行了比较．分析了信号光和泵浦光，以及粒子数沿着光纤方向的分布特点．最后对双程掺镱光纤放大器进行了优化．

Optical, structural and laser-induced damage threshold properties of HfO2 thin films prepared by electron beam evaporation

We prepare HfO2 thin films by electron beam evaporation technology. The samples are annealed in air after deposition. With increasing annealing temperature, it is found that the absorption of the samples decreases firstly and then increases. Also, the laser-induced damage threshold (LIDT) increases firstly and then decreases. When annealing temperature is 473K, the sample has the highest LIDT of 2.17J/cm(2), and the lowest absorption of 18 ppm. By investigating the optical and structural characteristics and their relations to LIDT, it is shown that the principal factor dominating the LIDT is absorption.

Proteomic Analysis of Proteins Involved in Spermiogenesis in Mouse

Spermiogenesis is a unique process in mammals during which haploid round spermatids mature into spermatozoa in the testis. Its successful completion is necessary for fertilization and its malfunction is an important cause of male infertility. Here, we report the high-confidence identification of 2116 proteins in mouse haploid germ cells undergoing spermiogenesis: 299 of these were testis-specific and 155 were novel. Analysis of these proteins showed many proteins possibly functioning in unique processes of spermiogenesis. Of the 84 proteins annotated to be involved in vesicle-related events, VAMP4 was shown to be important for acrosome biogenesis by in vivo knockdown experiments. Knockdown of VAMP4 caused defects of acrosomal vesicle fusion and significantly increased head abnormalities in spermatids from testis and sperm from the cauda epididymis. Analysis of chromosomal distribution of the haploid genes showed underrepresentation on the X chromosome and overrepresentation on chromosome 11, which were due to meiotic sex chromosome inactivation and expansion of testis-expressed gene families, respectively. Comparison with transcriptional data showed translational regulation during spermiogenesis. This characterization of proteins involved in spermiogenesis provides an inventory of proteins useful for understanding the mechanisms of male infertility and may provide candidates for drug targets for male contraception and male infertility.

The brave new era of human genetic testing

The commercialization of 'big science' is in full swing, leading to situations in which the ethical principles of academia are beginning to be compromised. This is exemplified by the profitable business of genetic ancestry testing. The goals of this sort

臭蛙群三种蛙类核型及染色体带型的比较(英文)

本文比较了3种臭蛙,即云南臭蛙（R. andersonii）、无指盘臭蛙（R.grahami）和滇南臭蛙（R.tiennanensis）的核型、C-带和银染核仁组织者区（Ag-NORs）。结果表明,3种臭蛙的核型均为2n=26（NF=52）,由5对大型染色体和8对小型染色体组成,与蛙科大多数种类的核型相似,但是染色体形态和次缢痕的位置和数目有差异。其中,云南臭蛙和无指盘臭蛙的核型相似程度比较大,与其他已报道的臭蛙类的核型相差不大,而滇南臭蛙的核型比较特殊,与其他臭蛙类的核型存在显著差异。 C-带技术显示的结果表明,3种臭蛙所有染色体的着丝点都有比较显著的C-带,而居间区C-带和端点C-带却存在明显的差异。3种中,滇南臭蛙的C-带带型比较特殊。有趣的是在研究中还发现,云南臭蛙的早中期细胞（染色体很长）染色体上发现了很多结构异染色质区,除着丝点C-带外,几乎所有的染色体上都有居间区或端点C-带,而在晚中期细胞中所观察到的C-带数目却较少,除着丝点外,只在少数染色体上发现了C-带。 云南臭蛙和无指盘臭蛙的Ag-NORs位于第10对染色体的长臂上,与该染色体上的次缢痕位置相对应,而滇南臭蛙的Ag-NORs位于第6...

3种念珠藻多糖对自由基的清除作用

研究了地木耳(Nostoc commune)、葛仙米(N.sphaeroides)和发菜(N.flagelliform e)3种念珠藻多糖对自由基的清除作用。结果表明,3种念珠藻多糖对超氧阴离子自由基和羟自由基具有很强的清除作用,且呈量效关系,地木耳清除超氧自由基作用最强,最高清除率达72.3%,葛仙米和发菜分别为46.7%、35.5%;发菜清除羟自由基效果最强,最高清除率达74.3%,葛仙米和地木耳清除率分别为49.0%、46.7%;3种念珠藻多糖对DPPH自由基的清除作用不显著。

Quantum-dot superluminescent diode: A proposal for an ultra-wide output spectrum

We propose a novel superluminescent diode (SLD) with a quantum dot (QD) active layer, which should give a wider output spectrum than a conventional quantum well SLD. The device makes use of inhomogeneous broadness of gain spectrum resulting from size inhomogeneity of self-assembled quantum dots grown by Stranski-Krastanow mode. Taking a design made out in the InxGa1-xAs/GaAs system for example, the spectrum characteristics of the device are simulated realistically, 100-200 nm full width of half maximum of output spectrum can be obtained. The dependence of the output spectrum on In composition, size distribution and injection current of the dots active region is also elaborated.

Analysis of leakage current in GaAs micro-solar cell arrays

The output characteristics of micro-solar cell arrays are analyzed on the basis of a modified model in which the shunt resistance between cell lines results in current leakage. The modification mainly consists of adding a shunt resistor network to the traditional model. The obtained results agree well with the reported experimental results. The calculation results demonstrate that leakage current in substrate affects seriously the performance of GaAs micro- solar cell arrays. The performance of arrays can be improved by reducing the number of cells per line. In addition, at a certain level of integration, an appropriate space occupancy rate of the single cell is recommended for ensuring high open circuit voltages, and it is more appropriate to set the rates at 80%-90% through the calculation.