Influences of the Fish-Mouth Project and the Groins on the Flow and Sediment Ratio of the Yangtze River Waterway

A depth-integrated two-dimensional numerical model of current, salinity and sediment transport was proposed and calibrated by the observation data in the Yangtze River Estuary. It was then applied to investigate the flow and sediment ratio of the navigati

Experimental Investigation On The Holdup Distribution Of Oil-Water Two-Phase Flow In Horizontal Parallel Tubes

An experimental investigation was conducted to study the holdup distribution of oil and water two-phase flow in two parallel tubes with unequal tube diameter. Tests were performed using white oil (of viscosity 52 mPa s and density 860 kg/m(3)) and tap water as liquid phases at room temperature and atmospheric outlet pressure. Measurements were taken of water flow rates from 0.5 to 12.5 m(3)/h and input oil volume fractions from 3 to 94 %. Results showed that there were different flow pattern maps between the run and bypass tubes when oil-water two-phase flow is found in the parallel tubes. At low input fluid flow rates, a large deviation could be found on the average oil holdup between the bypass and the run tubes. However, with increased input oil fraction at constant water flow rate, the holdup at the bypass tube became close to that at the run tube. Furthermore, experimental data showed that there was no significant variation in flow pattern and holdup between the run and main tubes. In order to calculate the holdup in the form of segregated flow, the drift flux model has been used here.

掺镁近化学计量比LiTaO3晶体的生长及光学性能

在同成分LiTaO3熔体中掺入一定剂量的K2O,采用顶部籽晶提拉法生长掺镁近化学计量比LiTaO3晶体。对晶体分别进行光谱分析,畴结构和抗光损伤阈值的测定。结果表明：与同成分掺镁LiTaO3晶体相比较,其紫外吸收边出现明显蓝移,红外吸收峰变弱。腐蚀晶片的晶相显微镜观察结果表明：掺镁近化学剂量比晶体的畴结构是较为规则的六边形;晶体的抗光致散射能力明显提高。

Broadband near-infrared emission in Er3+-Tm3+ codoped chalcohalide glasses

The near-IR emission spectra of Er3+-Tm3+ codoped 70GeS(2)-20In(2)S(3)-10CsI chalcohalide glasses were studied with an 808 nm laser as an excitation source. A broad emission extending from 1.35 to 1.7 mu m with a FWHM of similar to 160 nm was recorded in a 0.1 mol.% Er2S3, 0.5 mol.% Tm2S3 codoped chalcohalide glass. The fluorescence decay curves of glasses were measured by monitoring the emissions of Tm3+ at 1460 nm and Er3+ at 1540 nm, and the lifetimes were obtained from the first-order exponential fit. The luminescence mechanism and the possible energy-transfer processes are discussed with respect to the energy-level diagram of Er3+ and Tm3+ ions. (C) 2008 Optical Society of America

构树种质资源遗传多样性SRAP分子标记研究

构树（Broussonetia papyrifera L.）为桑科（Moraceae）构树属（Broussonetia）落叶乔木，广泛分布于亚洲东部及太平洋岛屿。它是我国重要的经济林木，具有重要的经济价值，其树皮纤维品质优良，自古就是造纸的优良原料；叶片可用作饲料；果实具有重要的药用价值；环境适应性强，是迅速绿化荒山、荒滩和盐碱地的理想树种。因此对构树这些特性的深入研究和开发利用具有非常重要的实际应用价值。本研究以日本和国内构树主要分布区域的的10种生态型及杂交构树共23份材料，摸索并改进了构树DNA的提取方法，建立了稳定的SRAP分子标记体系，以杂交构树组培苗为材料从120对引物组合中筛选出条带信息较高的17对SRAP引物，以这些引物对23份构树材料进行PCR扩增和标记分析。 本研究取得的主要结果如下： （1）本实验首次将SRAP技术应用于构树的研究中，建立起构树稳定的SRAP-PCR反应体系；实验中对影响扩增的5个主要因素进行了优化，确定20 μL PCR反应体系中各因素最适浓度：模板DNA浓度80 ng/(20 μL)，Mg2+浓度2.0 mM，dNTP浓度0.6 mM，引物浓度0.8 mM，Taq 酶浓度1.5 U/(20 μL)。 （2）从120对引物组合中筛选出来的17对SRAP引物对21份不同生态型构树样本（21份材料指的是除两份杂交构树材料外的其它生态型构树，以下同）进行PCR扩增，共扩增出439条带，平均每对引物25.5条，其大小介于100～1,000 bp之间，其中多态性条带319条，占总数的72.67%。 （3）用Popgene1.32软件进行分析，计算出Shannon信息指数（I）值为0.2275（0.2042），物种水平的Nei基因多样性（H）值为0.1336（0.1436），表明各生态型构树之间的平均遗传多态性不高，中国大陆各生态型构树Shannon信息指数（I）值仅为0.1675（0.2271），物种水平的Nei基因多样性（H）值为0.1039（0.1540），群体遗传多样性较低，构树的遗传分化主要存在于中国和日本之间。 （4）用NTSYS-2.10e软件进行聚类分析，发现不同生态型构树按距离关系远近及分布区域可划分为不同类群。在遗传相似系数0.57附近，对21份材料进行聚类分析发现其可分为两个群体，一类为日本生态型，另一类为中国生态型，表明日本构树与中国野生种构树种源遗传相似性较小。中国各生态型构树在遗传相似系数0.91处可分为5类，总体而言，中国各地区之间的构树遗传相似度较高。对杂交构树分析表明，其亲缘关系与日本构树（母本）更接近。 （5）日本及杂交构树的SCAR标记。本研究找到两条日本及杂交构树的特异性条带，回收、测序，再根据序列往里重新设计引物，转变成稳定性更好，更直观的SCAR标记，这为挑选性状优良的日本及杂交构树提供重要的参考，对其育种有一定的指导意义。其中一条片段经与NCBI数据库比对发现与拟南芥磺基转移酶家族基因具有较高的同源性。

Isolation and cDNA cloning of cholecystokinin from the skin of Rana nigrovittata

Many neuroendocrine peptides that are distributed in amphibian gastrointestinal tract and central nervous system are also found in amphibian skins, and these peptides are classified into skin-gut-brain triangle peptides, such as bombesins, gastrin-releasi

肝素钠生产中间产物效价的检测

将中间产物预先进行离心并调整 p H,采用绵羊血浆法测定效价 ,三氯乙酸法测定蛋白含量。正常情况下 ,猪肠粘膜的盐解液效价约为 6 0 0 0 0 u/副小肠 ,树脂吸附率为 79.6 %～ 84.0 % ,洗脱液得率 77.1%～ 81.8% ,乙醇沉淀物收率 80 .9%～ 85 .7%。酸化去蛋白质液和氧化液可分别按损失率 3%～ 7%和 10 %～ 2 0 %预测效价

鳜IL-1β基因的克隆及原核表达

用RACE PCR获得了鳜白介素-1β(IL-1β)的全长cDNA.鳜IL-1β的cDNA全长为1298 nt(核苷酸),其5′非编码区包含UTR 93 nt;3′非编码区包含452 nt;其开放阅读框内包含753 nt,翻译成251个氨基酸.将鳜IL-1β克隆到原核表达载体pET-32a上,在大肠杆菌Rosetta- gami(DE3)内以包涵体形式得以高效表达.

QtUCP-A program for determining unit-cell parameters in electron diffraction experiments using double-tilt and rotation-tilt holders

A computer program, QtUCP, has been developed based on several well-established algorithms using GCC 4.0 and Qt (R) 4.0 (Open Source Edition) under Debian GNU/Linux 4.0r0. it can determine the unit-cell parameters from an electron diffraction tilt series obtained from both double-tilt and rotation-tilt holders. In this approach, two or more primitive cells of the reciprocal lattice are determined from experimental data, in the meantime, the measurement errors of the tilt angles are checked and minimized. Subsequently, the derived primitive cells are converted into the reduced form and then transformed into the reduced direct primitive cell. Finally all the patterns are indexed and the least-squares refinement is employed to obtain the optimized results of the lattice parameters. Finally, two examples are given to show the application of the program, one is based on the experiment, the other is from the simulation. (C) 2008 Elsevier B.V. All rights reserved.

Storage of photoexcited electron-hole pairs in an AlAs/GaAs heterostructure created by electron transfer in real and kappa spaces

The storage of photoexcited electron-hole pairs is experimentally carried out and theoretically realized by transferring electrons in both real and k spaces through resonant Gamma - X in an AlAs/GaAs heterostructure. This is proven by the peculiar capacitance jump and hysteresis in the measured capacitance-voltage curves. Our structure may be used as a photonic memory cell with a long storage time and a fast retrieval of photons as well.

高阶布拉格光栅在SOI脊形波导上的光刻制作

在SOI脊形波导上通过光刻的方法制作了高阶布拉格光栅.采用顶层Si厚为2μm的SOI基片,通过半导体芯片制备中的光刻工艺,在脊高为935 nm,波导宽度为2μm的脊形波导上,分别制作了刻蚀深度为565 nm和935 nm的起伏型高阶布拉格光栅,测试表明,在1540～1640 nm波长范围内,得到了大于10 dB的消光比,实现了高阶布拉格光栅在SOI脊形波导上的滤波效果.理论和实验都证明了光栅刻蚀深度的增大将有利于增加高阶布拉格光栅的耦合系数,以及光栅周期数的增加会引起更大的光栅损耗.

铟掺杂ZnO体单晶的生长及其性质

研究了In掺杂n型ZnO体单晶的化学气相传输法生长和材料性质.利用霍尔效应、X射线光电子能谱、光吸收谱、喇曼散射、阴极荧光谱等手段对晶体的特性和缺陷进行了分析.掺In后容易获得浓度为10~(18)～10~(19)cm~(-3)的n型ZnO单晶,掺入杂质的激活效率很高.随着掺杂浓度的提高,ZnO单晶的带边吸收和电学性质等发生明显的变化.分析了掺In-ZnO单晶的缺陷及其对材料性质的影响.

面向高速应用的10位2GHz数模转换器

提出了一个刷新率达2GHz的10位电流驱动型数模转换器.在综合了精度与芯片面积等因素之后,该数模转换器使用6+4结构.采用电流型逻辑以提高转换器的速度,并采用Q~2 random walk方法设计了一个双中心对称的电流矩阵,确保数模转换器的线性度.该数模转换器核心版图面积为2.2mm×2.2mm,在3.3V单电压供电的情况下,该芯片功耗为790mW.

利用WDM光纤耦合器的光纤光栅传感解调技术

根据WDM光纤耦合器波长解调方案的工作原理、偏振特性以及影响系统波长分辨力的因素,提出一种改进的利用WDM光纤耦合器的光纤光栅传感解调技术.该技术在原技术的基础上,采用偏振控制器控制入射光偏振状态,提高了解调的精度和稳定性.对WDM光纤耦合器的多次波长扫描结果表明,采用偏振控制器后,其波长误差可减小到5pm左右.实验采用1540/1560nm的WDM光纤耦合器对单点光纤光栅应变传感器进行静态解调,结果表明:按此技术开发的解调系统具有0.01nm波长分辨力和10nm的波长线性解调范围.