金属长杆撞击带薄盖板约束炸药的引爆现象研究

通过实验的方法研究了金属长杆撞击带薄盖板约束炸药的引爆现象。观察带有随机偏航角的金属长杆以不同速度撞击炸药的响应情况。找出了金属长杆在不同入射角度和炸药约束条件下，炸药的冲击爆轰阈值。讨论了判别未知炸药发生爆轰、延迟爆轰、非爆轰性爆炸、点火后淬熄和不反应的试验测量手段和方法。结果表明：冲击引爆阈值速度，对于不覆板的裸炸药，随入射角度（0、30、45）的增加而增加；随着覆板厚度的增加而增加。炸药的侧向约束情况对发生延迟爆轰有影响。射弹偏航也是影响炸药引爆的因素之一。Jacobs 判据是关于炸药冲击引爆阈值的经验判据，它可以适用于8701 炸药，文中给出了对平头钢弹、钢覆板情况下,用实验数据拟合的Jacobs公式。由于其它机理引发延迟爆轰（XDT）的现象是存在的，Jacobs 判据对这类现象不适用。

基于光子数目比较的激光测距法

提出了一种新颖的激光测距方法。该方法避开了传统激光测距法中使用复杂辅助电子设备对脉冲计时或比较相位差的过程，而主要通过光学手段分析和提取待测距离信息，最终通过比较大量光子数目的方法求得待测距离。并利用单轴晶体的双折射和全内双反射性质，用特殊结构的单块LiNbO3晶体设计了实施该方法的主体装置。结果表明，该激光测距法同目前普遍使用的激光测距法相比，不但简化了结构，而且有很高的测距精度，从而为激光测距开拓了一种新的思路。

Efficient diode-pumped Yb : Gd2SiO5 laser

An efficient diode-pumped laser was demonstrated by using an ytterbium-doped laser crystal, Yb:Gd2SiO5 (Yb:GSO), wherein Yb3+ ions exhibit the largest ground-state splitting among all the ytterbium-doped crystals. The Yb:GSO laser can be operated at a low pumping threshold, and the most efficient laser occurs around 1088 nm since the corresponding emission band has the largest emission cross section and the lowest thermal population. A slope efficiency of 75% was demonstrated for a continuous-wave Yb:GSO laser at 1094 nm, and self-pulsed lasers were achieved within the tunable range of 1091-1105 nm, which are the longest laser wavelengths achieved for Yb3+ lasers. (c) 2006 American Institute of Physics.

Efficient tunable diode-pumped Yb : LYSO laser

We demonstrated efficient laser action of a new ytterbium-doped oxyorthosilicate crystal Yb:LuYSiO5 ( Yb: LYSO) under high-power diode-pumping. The spectroscopic features and laser performance of the alloyed oxyorthosilicate crystal are compared with those of ytterbium-doped lutetium and yttrium oxyorthosilicates. In the continuous-wave laser operation of Yb: LYSO, a maximal slope efficiency of 96% and output power of 7.8 W were respectively achieved with different pump sources. The Yb: LYSO laser exhibits not only little sensitivity to the pump wavelength drift but also a broad tunability. By using a dispersive prism as the intracavity tuning element, we demonstrated that the continuous-wave Yb: LYSO laser exhibit a continuous tunability in the spectral range of 1014-1091 nm. (c) 2006 Optical Society of America.

珙桐种群生态学研究

本文是中国科学院“八五”重大项目：“生物多样性保护与持续利用的生物学基础”中的子课题“中国濒危特有动、植物保护生物学及种群生存力分析”的一部分。本文研究了我国一级保护植物珙桐(Davidia involucrata Baill．)在种群生态学、群落生态学各方面的特征，主要包括其天然分布，群落类型，种群空间分布格局，植株生长规律，种群生物量结构及变化规律，元素化学成份，种群年龄结构，数量统计及生存力分析等。 研究结果表明：珙桐分布区是连续的，其变种光叶珙桐（Davidia involucrata var. vilmoriniana (Dode) wanger)的分布区存在间断;珙桐群落可依优势种不同分为多种类型，但都属于亚热带中山落叶——常绿阔叶混交林类型;群落区系成份复杂，地理成份以北温带及东亚成分占绝对优势：种群空间分布格局无论在不同群落中还是在不同发育阶段中均属集群分布：植株胸径、树高及材积生长符合Logistic方程：种群生物量随群落类型不同而有较大差异，种群增长规律符合Logistic增长;种群年龄结构稳定，但实生苗的匮乏对种群更新不利：种群存活曲线属Deevy I型。对影响种群生存力的因素分析表明，主要的因素有系统压力和环境因素。

Radical Scavenging and Antimicrobial Activities of Methanol Extracts of Two Kinds of Formicary

对两种不同的蚂蚁窝进行甲醇提取,并对提取物进行了急性毒性、抗自由基,酚含量、还原能力和抗菌活性的检测。二苯基三硝基肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基的清除能力的检测表明:两种蚂蚁窝甲醇提取物都具有显著的自由基清除能力,并呈现出剂量依赖性,而且,在高浓度时(5~10mg·mL-1),它们的自由基清除能力甚至显著地高于二丁基羟基甲苯(butylated hydroxyl toluene,BHT)。酚的含量和还原能力分别用福林酚试剂和铁氰化钾还原反应来测定,统计分析显示两种蚂蚁窝的抗氧化能力和其酚含量、还原能力都存在着正相关。两种蚂蚁窝甲醇提取物都具有抗革兰氏阴性菌和革兰氏阳性菌的活性,但它们却对真菌没有作用。

Flazinamide, a novel beta-carboline compound with anti-HIV actions

A beta-carboline compound, flazin isolated from Suillus granulatus has been shown weak anti-HIV-1 activity. Based on the structure of flazin, flazinamide [1-(5'-hydromethyl-2'-furyl)-beta-carboline-3-carboxamide] was synthesized and its anti-HIV activitie

Increasing top-down suppression from prefrontal cortex facilitates tactile working memory

Navigated transcranial magnetic stimulation (TMS) combined with diffusion-weighted magnetic resonance imaging (DW-MRI) and tractography allows investigating functional anatomy of the human brain with high precision. Here we demonstrate that working memory (WM) processing of tactile temporal information is facilitated by delivering a single TMS pulse to the middle frontal gyrus (MFG) during memory maintenance. Facilitation was obtained only with a TMS pulse applied to a location of the MFG with anatomical connectivity to the primary somatosensory cortex (S1). TMS improved tactile WM also when distractive tactile stimuli interfered with memory maintenance. Moreover, TMS to the same MFG site attenuated somatosensory evoked responses (SEPs). The results suggest that the TMS-induced memory improvement is explained by increased top-down suppression of interfering sensory processing in S1 via the MFG-S1 link. These results demonstrate an anatomical and functional network that is involved in maintenance of tactile temporal WM. (C) 2009 Elsevier Inc. All rights reserved.

Lentivirus介导分泌神经营养因子-3的基因工程神经干细胞移植治疗脊髓损伤的实验研究

神经干细胞(NSC)是中枢神经系统中具有自我更新能力和多种分化潜能的细胞,是脊髓损伤(SCI)后再生修复的理想材料和基因载体。我们探讨了Lentivirus介导分泌神经营养因子-3(NT-3)的基因工程NSC移植治疗SCI的可行性,以期为SCI后功能恢复的实验研究以及进一步临床研究提供基础资料。材料与方法一、实验材料1.试剂与来源:DMEM/F12、B27、N2(Gibco公司),bFGF(Sigma公司),Nestin抗体、NF-200抗体、GFAP抗体(武汉博士德公司),羊抗鼠NT-3抗体(USB公司),超信号West Pico化学发光底物试剂盒(Pierce34079ZZ)、人胚肾293T细胞购自武汉大学保藏中心,携带NT-3和绿色荧光蛋白(GFP)的Lentivirus的各种质粒由美国迈阿密大学Oudega M教授提供。2.实验动物:Wistar大鼠由成都军区昆明总医院实验动物中心提供。二、实验方法1.NSC的分离培养:取孕14d的Wistar胎鼠皮层组织,分离筋膜和血管,反复剪碎,再用200目细胞筛过滤,转入DMEM/F12,加B27添加剂、bFGF(20ng/ml);6~7d传代。

香溪河小水电的梯级开发对浮游藻类的影响

以香溪河干流上5个连续的小水电站为对象,于2005年10月20—22日分别对其浮游藻类和主要理化指标进行研究.结果表明:硅藻占绝对优势(95.54%),其中,线性曲壳藻(Achnanthes linearis)、披针曲壳藻椭圆变种(A.lanceolatavar.elliptica)、扁圆卵形藻(Cocconeisplacentula)为绝对优势种,其平均相对丰富度分别为23.96%、18.62%和12.48%;所有样点的平均藻类密度为6.29×105ind.L-1,最高为1.81×106ind.L-1,