High optical-optical efficiency of 52.5% obtained in high power Nd : YAG ceramic laser

Using a quite uniformly side-around arranged compact pumping system, a high power Nd:YAG ceramic quasi-CW laser has been demonstrated with high optical-to-optical conversion efficiency over 50% for the first time. With 450 W quasi-CW stacked laser diode bars pumping at 808 run. 236 W Output at 1064 run was obtained and no saturation phenomena were observed.

《中国植物志》第52卷2分册(红树林科.海桑科.石榴科.玉蕊科)

1、红树科和海桑科是中国植物志的一部分，1980年开始编著，1983年出版，本文记载红树科6属13种1变种，6属中除山红树属和竹节树属是内陆种类，其余4属均是组成红树林的主要树种，红树科的木杬属、角果木属、秋茄树属和红树属它们的树皮都含有丰富单宁为侵染皮革和染料的主要原料，又是防风防浪护堤的海岸防护林的主要树种及盐土指示植物，木材大都坚硬，纹理密微，在药用方面有止痛等作用。海桑科与红树科的生态习性极为相似也是构成红树林的主要树种和海岸防林不可缺少的种类，本文记载中国有2属4种。以上两科均详细叙述它们的形态、生态习性和经济用途。2、通过研究多年搜集的标本和资料，报导石榴科和玉蕊科的种类、分布和经济用途。石榴原产地中海沿岸至伊朗及其邻近地区，汉时张骞出使西域引入我国栽培，是我国第一批有文字记载的外来经济树种之一，既可食用和药用，又供观赏，综述历代文献，描述其形态演变，对研究外来（特别是地中海沿岸）经济植物的驯化有重要的意义。玉蕊科是有代表性的热带植物群，我国种类虽不多，但其发现对论证我国植物区系的热带亲缘的理论提供了直接的证据，故有一定的科学意义。

Detecting positive darwinian selection in brain-expressed genes during human evolution

To understand the genetic basis that underlies the phenotypic divergence between human and non-human primates, we screened a total of 7176 protein-coding genes expressed in the human brain and compared them with the chimpanzee orthologs to identity genes

人精液凝固蛋白SgI-52的表达与抗菌活性研究

以人精囊腺cDNA为模板,用嵌套式PCR技术扩增出编码成熟人精液凝固蛋白I(semenogelin I,SgI)第85-136位氨基酸(SgI-52)的核苷酸序列并将其插入载体pMAL-p2X,成功构建的表达载体pMAL-p2Z/SgI-52转化大肠杆菌DH5 α后,重组融合蛋白诱导表达于大肠杆菌周质中.经第X因子剪切及超滤处理,得到表达的重组SgI-52.质谱分析结果证明重组SgI-52为目的肽.重组人SgI-52对大肠杆菌ATCC 25922标准株以及耐氨苄标准株ML-35P的最低抑制浓度MIC分别为32.45以及46.30μg/mL.我们的结果及相关研究提示在人精液液化过程中人精液凝固蛋白I的不同降解产物可能行使不同的生物学功能,值得进行深入研究.

Zinc coupling potentiates anti-HIV-1 activity of baicalin

Baicalin (BA) has been shown with anti-HIV-1 activity. Zinc is a nutrient element. The anti-HIV-1 activity of zinc complex of baicalin (BA-Zn) in vitro was studied and compared with the anti-HIV-1 activities between BA and BA-Zn in the present study. Our results suggested that BA-Zn has lower cytotoxicity and higher anti-HIV-1 activity compared with those of BA in vitro. The CC(50)s of BA-Zn and BA were 221.52 and 101.73 muM, respectively. The cytotoxicity of BA-Zn was about 1.2-fold lower than that of BA. The BA and BA-Zn inhibited HIV-1 induced syncytium formation, HIV-1 p24 antigen and HIV-1 RT production. The EC(50)s of BA-Zn on inhibiting HIV-1 induced syncytium formation (29.08 muM) and RT production (31.17 muM) were lower than those of BA (43.27 and 47.34 muM, respectively). BA-Zn was more effective than BA in inhibiting the activities of recombinant RT and HIV-1 entry into host cells. Zinc coupling enhanced the anti-HTV-1 activity of baicalin. (C) 2004 Elsevier Inc. All rights reserved.

温度对草鱼能量收支的影响

于1992年4月-1992年5月在22，26及3℃下，以莴苣叶为食物，不限量摄食，测定草鱼的能量收支。结果表明，草鱼摄食率及生长率均随温度上升而增加；最大摄食率（Cw：％　W／d）与水温（T：℃）的关系为：CW=0．0405T2.324；温度对食物能分配于能量收支各组分的比例没有显著影响，在3个温度下测定的平均能量收支式为：100C=29.89F＋3．30U＋52．48R十14．34G，式中C为食物能，F为排粪能，U为排泄能，R为代谢能，G为生长能。

InAs/ln(0.52)Al(0.48)As quantum wire structure with the specific layer-ordering orientation on InP(001)

Quantum wires were formed in the 6-period InAs/In0.52Al0.48As structure on InP(0 0 1) grown by molecular beam epitaxy. The structure was characterized with transmission electron microscopy. It was found that the lateral periodic compositional modulation in the QWR array was in the [1 (1) over bar 0] direction and layer-ordered along the specific orientation deviating from the [0 0 1] growth direction by about 30 degrees. This deviating angle is consistent with the calculation of the distribution of elastic distortion around quantum wires in the structure using the finite element technique. (C) 1999 Elsevier Science B.V. All rights reserved.

MOCVD生长Al_(0.48)Gao_(0.52)N/Al_(0.54)Ga_(0.36)N多量子阱的结构和光学特性

采用金属有机物化学气相淀积(MOCVD)技术,在蓝宝石衬底上生长了Al_(0.48)Gao_(0.52)N/Al_(0.54)Ga_(0.36)N多量子阱(MQWs)结构.通过双晶X射线衍射(DCXRD)、原子力显微镜(AFM)和阴极荧光(CL)等测试技术,分别对样品的结构和光学特性进行了表征.在DCXRD图谱中,可以观察到明显的MQWs衍射卫星峰,通过拟和,MQWs结构中阱和垒的厚度分别为2.1和9.4 nm,Al组分分别为0.48和0.54.在AFM表面形貌图上,可以观察到清晰的台阶流,表明MQWs获得了二维生长;与此同时,MQWs结构存在一些裂缝,主要原因为AlGaNMQWs结构和下层GaN层间存在很大的应力.CL测试表明,AlGaN MQWs结构的发光波长为295 nm,处于深紫外波段,同时观察到处于蓝光、绿光波段的缺陷发光.

In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As量子阱中的正磁电阻效应

在低温强磁场条件下,对In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As量子阱中的二维电子气进行了磁输运测试.在低磁场范围内观察到正磁电阻效应,在高磁场下这一正磁电阻趋于饱和,分析表明这一现象与二维电子气中的电子占据两个子带有关.在考虑了两个子带之间的散射效应后,通过分析低磁场下的正磁电阻,得到了每个子带电子的迁移率,结果表明第二子带电子的迁移率高于第一子带电子的迁移率.进一步分析表明,这主要是由两个子带之间的散射引起的.

两个子带占据的In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As量子阱中填充因子的变化规律

研究了低温(1.5K)和强磁场(0-13T)条件下,InP基In_(0.53)Ga_(0.47)As/In_(0.52)A_(l0.48)As量子阱中电子占据两个子带时填充因子随磁场的变化规律.结果表明,在电子自旋分裂能远小于朗道能级展宽的情况下,如果两个子带分裂能是朗道分裂能的整数倍时,即⊿E_(21)=κ*ω_c(其中κ为整数),填充因子为偶数;当两个子带分裂能为朗道分裂能的半奇数倍时,即⊿E_(21)=(2κ+1*ω/2,填充因子出现奇数.

In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As量子阱中双子带占据的二维电子气的输运特性

研究了不同沟道厚度的In_(0.53) Ga_(0.47)As/In_(0.52)Al_(0.48)As量子阱中双子带占据的二维电子气的输运特性.在考虑了两个子带电子之间的磁致子带间散射效应后,通过分析Shubnikov-de Haas振荡一阶微分的快速傅里叶变换结果,获得了每个子带电子的浓度、输运散射时间、量子散射时间以及子带之间的散射时间.结果表明,对于所研究的样品,第一子带电子受到的小角散射更强,这与第一子带电子受到了更强的电离杂质散射有关.