The wave model of mesothermal plasma near wakes and Korteweg-de Vries equation

The stationary two-dimensional (x, z) near wakes behind a flat-based projectile which moves at a constant mesothermal speed (V∞) along a z-axis in a rarefied, fully ionized, plasma is studied using the wave model previously proposed by one of the authors (VCL). One-fluid theory is used to depict the free expansion of ambient plasma into the vacuum produced behind a fast-moving projectile. This nonstationary, one-dimensional (x, t) flow which is approximated by the K-dV equation can be transformed, through substitution, t=z/V∞, into a stationary two-dimensional (x, z) near wake flow seen by an observer moving with the body velocity (V∞). The initial value problem of the K-dV equation in (x, t) variables is solved by a specially devised numerical method. Comparisons of the present numerical solution for the asymptotically small and large times with available analytical solutions are made and found in satisfactory agreements.

第57届国际宇航大会会议介绍

1概况 第57届国际宇航大会于2006年10月2—6日在西班牙瓦兰西亚召开，10月1日还召开了国际宇航科学院院士会和国际宇航学会各委员会会议．会议参加人数超过2000人，开幕式大礼堂座无虚席．这次会议的主题是“开创更贴近人民的空间事业（bringing space closer to people）”．大会在瓦兰西亚的大展览馆召开，群众与代表交混．除大会会场外，所有分会会场都是用木板临时安装的，会场条件简单．

可溶性L-选择素竞争性调控膜L-选择素与其配体PSGL-1反应动力学

国家自然科学基金项目(30730032)

1 X N dynamic optical coupler based on Dammann gratings

We present two novel 1XN dynamic optical couplers that are based on Dammann gratings to achieve dynamic optical coupled technology. One is presented by employing a specially designed Dammann grating that consists of the Dammann-grating area and the blank area. The other is developed by using two complementary even-numbered Dammann gratings. The couplers can achieve the function conversion between a beam splitter and a combiner according to the modulation of the gratings. We have experimentally demonstrated 1X8 dynamic optical couplers at the wavelength of 1550 nm. The experimental results and the analyses are reported in detail.

鱼类微孢子虫的研究进展

中国科学院知识创新重大项目 (编号KZCX1 SW 12 ); 中国博士后科学基金项目 (编号 :2 0 4180 171)资助

鲤鱼不同品种(系)红血球抗原特异性的初步研究

用血球凝集和血清吸收试验的方法,对若干个鲤鱼品种及鲤鱼人工雌核发育系的红血球中的某些同种异型抗原纯合性进行了初步研究。①以抗雌核发育红鲤抗血清(abs/R)为试剂,三个雌核发育系(R_(8305),R_(8413),RMGF_1)的RBC反应值分别为1521—2360,1521—2028,853—1521,普通红鲤、镜鲤、白鲢的反应值在80—782。②abs/8305与abs/8413经靶细胞相互吸收后的残留活性显著降低(均为320),而以自鲢RBC吸收后抗血清活性不变。作者认为这部分抗原在鲤鱼种以下的品

Improved diphasic nc-si/a-si : H I-layer materials using PECVD

Two series of films has been prepared by using a new regime of plasma enhanced chemical vapor deposition (PECVD) in the region adjacent to the phase transition from amorphous to crystalline state. The photoelectronic properties of the films have been investigated as a function of crystalline fraction. In comparison with typical a-Si:H, these diphasic films with a crystalline fraction less than 0.3 show a similar optical absorption coefficient, higher mobility life-time product ( LT) and higher stability upon light soaking. By using the diphasic nc-Si/a-Si films as the intrinsic layer, a p-i-n junction solar cell has been prepared with an initial efficiency of 9. 10 % and a stabilized efficiency of 8.56 % (AM 1.5, 100 mW/cm(2)).

一种改善双射S盒密码特性的有效算法

S盒是许多密码算法中的惟一非线性部件 ,它的密码强度决定了整个密码算法的安全强度 利用基因算法可以构造出密码特性良好的S盒 ,实践证明 ,若能在基因算法的中间过程对子S盒的密码特性作局部优化 ,将会使算法更加有效 WilliamMillan曾给出一个改善双射S盒的非线性度的算法 而差分均匀性也是衡量S盒密码特性的一个重要指标 ,研究了如何利用差分矩阵来改善差分均匀性 ,并给出了一个实用的算法 ,它能同时改善一个随机选取的双射S盒的非线性度和差分均匀性

米脂县农地承载力系统动力学分析

在综合分析米脂县农地承载力系统结构、关系的基础上,以1998年为起始年建立系统动力学模型,根据米脂县社会经济发展现状及未来规划,设定了3种不同的方案和3种营养标准,模拟了米脂县2008-2028年农地人口承载力趋势,通过各方案比较,得出了较优的方案,最后提出了提高该地区农地承载力的政策建议。

“第七届全国绿色环保肥料(农药)新技术、新产品交流会”专题报告

本次会议有27个专题报告,各具特色、异彩纷呈,突出展现了腐植酸肥料(农药)领域开发应用的最新研究和开发进展。为了让读者了解本次会议取得的成果,本栏目按会议专题报告顺序,将报告提要、报告中具有代表性的图或表、报告人简介和报告评价等内容编辑刊出。见21～45页。

大连市2000～2004年农业生态系统能值分析

能值为环境、资源、人类劳务、信息和发展决策的分析评价提供了新尺度。为了更好地评价大连市农业种植业对太阳能资源的利用情况和大连市农业的可持续发展情况,本文在简单阐述能值分析理论基础上,运用能值分析方法,计算分析大连市2000年到2004年农业生态系统的能值投入与产出,并根据实际情况构建了能值分析指标体系。从净能值产出率和环境负荷力角度来量化分析大连市农业系统的发展状况。结果表明:从2000年到2004年,大连市农业生态系统净能值产出率分别为9.48、9.24、8.52、8.00和7.59,环境负荷力分别为10.21、11.49、6.26、10.41和9.03。大连市农业生态系统发展整体处于较好态势,但对环境的压力较大,应进一步加大其高科技含量的能值投入,以促进农业系统的更好发展。