湖北省三道河水库底栖动物的初步研究

2007年8月至2008年4月,在湖北省三道河水库6个采样点调查底栖动物,共采集到底栖动物17种,其中水生昆虫11种,均为摇蚊科;寡毛类6种,均为颤蚓科.春季优势种为前突摇蚊,夏季优势种为小摇蚊、流水长跗摇蚊和前突摇蚊,秋、冬季优势种为霍甫水丝蚓.底栖动物种类数、密度和生物量随季节变化明显,种类数夏季>冬季>秋季>春季,密度和生物量春季>冬季>秋季>夏季.周年密度和生物量分别为366.42±102.93ind./m2和0.5649±0.1779g/m2,属贫营养型水库.现存量自坝前向库尾逐步递增,Shan

Unified modelling in support of organization design and change

The aim of this research is to provide a unified modelling-based method to help with the evaluation of organization design and change decisions. Relevant literature regarding model-driven organization design and change is described. This helps identify the requirements for a new modelling methodology. Such a methodology is developed and described. The three phases of the developed method include the following. First, the use of CIMOSA-based multi-perspective enterprise modelling to understand and capture the most enduring characteristics of process-oriented organizations and externalize various types of requirement knowledge about any target organization. Second, the use of causal loop diagrams to identify dynamic causal impacts and effects related to the issues and constraints on the organization under study. Third, the use of simulation modelling to quantify the effects of each issue in terms of organizational performance. The design and case study application of a unified modelling method based on CIMOSA (computer integrated manufacturing open systems architecture) enterprise modelling, causal loop diagrams, and simulation modelling, is explored to illustrate its potential to support systematic organization design and change. Further application of the proposed methodology in various company and industry sectors, especially in manufacturing sectors, would be helpful to illustrate complementary uses and relative benefits and drawbacks of the methodology in different types of organization. The proposed unified modelling-based method provides a systematic way of enabling key aspects of organization design and change. The case company, its relevant data, and developed models help to explore and validate the proposed method. The application of CIMOSA-based unified modelling method and integrated application of these three modelling techniques within a single solution space constitutes an advance on previous best practice. Also, the purpose and application domain of the proposed method offers an addition to knowledge. © IMechE 2009.

A framework for estimating difficulty and exclusion from tasks during inclusive design

Measuring capability variations within the population isanimportant process that can be used to support decision making regarding the inclusivity of design for all users, thus allowing the level of exclusion tobe defined veryearly and throughout the design process. Our hands often represent a central feature of the human-task interaction, and therefore, variations in the capabilities of the hands has the potential to exclude people from all or part of the tasks they perform. Data is presented from the performance of 15 people in one of three age groups (18-40, 41-64 and 65+). Using a classification system for defining hand actions the prevalence of different grips in response to a range of physical task demands was mapped in a way that allowed capability to be measured against other variables such as task quality. This was found toenhance thegranularity with which exclusion could be both measured and predicted.

鱼腥藻PCC7120受缺铁诱导的外膜蛋白

利用双相法结合蔗糖密度梯度超离心制备获得高纯度的鱼腥藻PCC7120(Anabaena sp.PCC7120)外膜,以双向凝胶电泳分析受缺铁诱导的外膜蛋白。发现缺铁导致5种外膜蛋白水平显著上调,经MALDI-TOF-MS鉴定都是类似siderophore受体的蛋白。通过细菌荧光素酶报告基因luxAB研究相应基因的转录调控,发现它们在转录水平受缺铁诱导,并且响应缺铁诱导的表达模式存在差异。利用luxAB检测其中一些启动子的表达有可能用于水体中可利用铁离子的生物监测。

葛仙米对丁草胺胁迫的响应

研究了丁草胺对可食用蓝藻葛仙米(Nostoc sphaeroides)生理和代谢活性的影响．用不同浓度的丁草胺处理葛仙米,结果显示低浓度(5 mg·L-1)丁草胺使其光合作用、呼吸作用和光合系统Ⅱ活性增强,高浓度丁草胺(>5 mg·L-1)限制其光合作用、呼吸作用和光合系统Ⅱ活性．同时丁草胺对葛仙米膜结构和功能具有破坏作用,随着丁草胺处理浓度增大,质膜透性不断增大,丙二醛和超氧自由基阴离子含量升高；在低浓度丁草胺处理时,类胡萝卜素含量增加,超氧化物歧化酶(SOD)活性增强,高浓度丁草胺处理时,类胡萝卜素含

Photomechanically Induced Phase Transitions in Ferroelectric Liquid Crystals

We report optically induced phase transtions occurring in two different host ferroelectric liquid crystals; SCE13 a multicomponentmixture optimised for room temperature performance, and CE8 a single component liquid crystal. These act as host liquid crystals for a novel guest azo dye, which can be made to photoisomerise using low power density U.V. illumination, resulting in dramatic changes in sample properties. We have shown that the magnitude of spontaneous polarisation of systems can be isothermally and reversibly induced or reduced, with the consequent appearance or disappearance of optical switching hysteresis. We discuss the parameters controlling the behaviour of the systems under U.V. illumination and suggest mechansims by which the transitions may occur. © 1993, Taylor & Francis Group, LLC. All rights reserved.

抚仙湖子陵吻鰕虎鱼繁殖策略的可塑性研究

通过比较子陵吻鰕虎鱼的一个入侵种群(抚仙湖)和两个原产种群(巢湖和洞庭湖)的繁殖策略的异同,研究了该物种在被引入抚仙湖后所作出的繁殖策略上的变化。入侵种群的产卵时间为7—10月份,产卵持续时间长达4个月;而两个原产种群的产卵时间均为7—9月份,产卵持续时间达3个月。三个种群的个体相对繁殖力分别为2826.5±827.4(抚)、3657.9±366.5(巢)和3592.2±1160.5(洞)粒/g,两个原产种群之间无显著差异(p>0.05),而入侵种群的相对繁殖力显著下降(p<0.05)。另外,入侵种群的月

菜籽粕对异育银鲫免疫应答能力的影响

试验鱼以投喂饲料的不同和是否注射抗原共分为10组,即免疫组:A、B、C、D、E组,免疫对照组:a、b、c、de、组,饲料对照组:A、a组。饲料试验组B、C、D、E、bc、、d、e组。其中,饲料对照组以豆粕和鱼粉为基础蛋白源,饲料试验组分别以双低菜籽粕和普通菜籽粕等氮替代对照组中50%(B、b;D、d)和100%(C、c;E、e)的豆粕蛋白,测定异育银鲫血液白细胞和头肾吞噬细胞的吞噬活性、血清溶菌酶活性、血清补体(C3,C4)含量、血清凝集抗体效价及免疫保护率。结果表明:从免疫后21 d开始,饲料试验组E、

Modelling 2DEG charges in AlGaN/GaN heterostructures

In this paper we compare different approaches to calculating the charge density in the 2DEG layer of AlGaN/GaN HEMTs. The methods used are (i) analytical theory implemented in MATLAB, (ii) finite-element analysis using semiconductor TCAD software that implements only the Poisson and continuity equations, and (iii) 1D software that solves the Poisson and Schrödinger equations self-consistently. By using the 1D Poisson-Schrödinger solver, we highlight the consequences of neglecting the Schrödinger equation. We conclude that the TCAD simulator predicts with a reasonable level of accuracy the electron density in the 2DEG layer for both a conventional HEMT structure and one featuring an extra GaN cap layer. In addition, while the sheet charge density is not significantly affected by including Schrödinger, its confinement in the channel is found to be modified. © 2012 IEEE.

洗涤剂禁(限)磷对流域水质影响预测

本文在确定流域洗涤剂的磷在水体磷负荷中所占的比重及贡献率的基础上 ,采用Thomoamn数学模型 ,对在实施洗涤剂禁限磷措施后 ,流域水质的响应进行预测 ,并评估洗涤剂禁限磷的环境效果 .水质预测结果表明 ,实行限、禁磷措施后 ,供水水质磷含量将从目前的 0 .2 4mg/L降至 0 .18mg/L ,磷负荷削减了 2 5 % ;如严格控制流域禽畜散养 ,削减非点源磷盐 6 0 % ,供水水质处于地面水Ⅱ类水质 (0 .1mg/L)标准临界水平

Cooperative attitude synchronization in satellite swarms: A consensus approach

The present paper considers the problem of autonomous synchronization of attitudes in a swarm of spacecraft. Building upon our recent results on consensus on manifolds, we model the spacecraft as particles on SO(3) and drive these particles to a common point in SO(3). Unlike the Euler angle or quaternion descriptions, this model suffers no singularities nor double-points. Our approach is fully cooperative and autonomous: we use no leader nor external reference. We present two types of control laws, in terms of applied control torques, that globally drive the swarm towards attitude synchronization: one that requires tree-like or all-to-all inter-satellite communication (most efficient) and one that works with nearly arbitrary communication (most robust).

卵巢发育阻滞的人工三倍体鱼减数分裂染色体配对的光镜观察

采用界面铺张制片和硝酸银一步染色的方法，对人工三倍体水晶彩鲫卵巢发育阻滞型个体的减数分裂染色体配对进行了光镜观察。在分化有初级卵母细胞的卵巢发育阻滞型的三倍体鱼中，减数分裂粗线期细胞主要由二价体和单价体组成，也见有少量三价体和其它多价体。其染色体成员数大多在９０左右；在不同细胞间，染色体的大小变化较大；配对联会过程中形成的配对叉和产生的特异蛋白在一些细胞中明显可见。文中讨论了三倍体染色体配对紊乱与卵母细胞发育受阻的关系，并认为人工三倍体鱼是进行减数分裂染色体配对和联会机理研究的好材料。