罗氏沼虾胸神经节中促进卵母细胞发育的激素的初步分离

罗氏沼虾成虾的胸神经节匀浆经Sephadex-G50柱层析所得第2个峰再经HPLC分离得到9个组分. 第1个组分和罗氏沼虾期卵巢小块一起体外培养36h可使卵母细胞的直径较对照组非常显著地增大P0.01这种增大卵母细胞直径的能力随该组分中蛋白质浓度的增加而增加. 在该组分中的激素分子量在1.3kDa左右. 结果显示罗氏沼虾胸神经节能分泌促进卵母细胞发育的激素.     

Introduction of structural aseismic research in China in recent four years

Introduction Greeting the coming of the 21st century, Professor HU Yu-xian and other Chinese scholars briefed the trend of earthquake engineering in China and aboard (HU, 1999; HU, ZHOU, 1999). The experiences and lessons learning from the destructive earthquakes in China and abroad in re-cent years, the damage action of the large velocity impulse in ground motion in near field in seis-mic design, numerous earthquake examples show that there are many weaknesses in aspects of earthquake p…     

基础隔震单层偏心结构扭转地震反应分析

采用微分型滞回恢复力模型模拟隔震支座的恢复力特性，对基础隔震单层偏心结构的扭转地震反应进行分析，研究隔震系统偏心距和上部结构偏心距对结构扭转反应的影响。结果表明，采用隔震技术可以显著降低隔震结构的扭转地震反应。     

Design of efficient base isolation for hammers and presses

Foundations supporting hammers and presses have to withstand powerful short-period impact loads. When designing these foundations, their vibration amplitudes and the forces transmitted to the supporting piles or soil medium must be reduced to meet serviceability and stability requirements. Mounting systems are often used to achieve this goal. The objectives of this paper are to investigate the efficiency of mounting systems for different foundation configurations and to provide practical guidance for their design. A comprehensive parametric study was conducted and the results were used to establish a set of charts for the design of efficient mounting systems.     

Assessment of δ13C and C/N ratios in bulk organic matter as palaeosalinity indicators in Holocene and Lateglacial isolation basin sediments,northwest Scotland

Carbon isotopes (δ¹³C) and C/N ratios from bulk organic matter have recently been used as alternative proxies for relative sea‐level (RSL) reconstruction where there are problems associated with conventional biological indictors. A previous study on a single isolation basin (Upper Loch nan Eala) in northwest Scotland has shown a clear relationship between δ¹³C, C/N ratios and palaeosalinity from Younger Dryas and Holocene aged sediments. In this paper we present results of δ¹³C and C/N ratio analyses from other isolation basins in northwest Scotland over the Holocene and the Lateglacial period in order to validate this technique. The results from the Holocene sequences support the earlier findings that this technique can be used to identify RSL change from isolation basins over the Holocene in this region. The relationship between δ¹³C, C/N ratios and RSL change is not apparent in sediments of Lateglacial age. Other environmental variables such as atmospheric CO₂ concentration, poor vegetation development and temperature influence δ¹³C values during this period. Copyright © 2007 John Wiley & Sons, Ltd.     

钢梁阻尼器的最佳延性率及其控制

基于双线性和三线性的力－位移滞回线假设，导出了钢梁阻尼器隔震系统等效阻尼比与阻尼器延性率的关系；为了获得大阻尼比隔震系统，以尽量减小隔震系统的地震反应，求得了使系统阻尼比为最大的阻尼器相应延性率（即最佳延性率）所需满足的条件；给出了在给定地震地面运动输入条件下，使系统阻尼器变形位移达到最佳延性率的阻尼器初始刚度和屈服位移的确定方法。     

Isolation and identification of alginate-degrading bacteria and formation of alginase

I~crIONThestudiesofseaalgageneticengineeringstartedintheearly1950s.HOwever,itSdevelopmentishinderedgreatlybecauseitisdifficulttogetisolatedlivecellsandprotoplasts.TheenZymeswhicharesuitabletohigherplantsarenotsuitabletoisolatetheseaalgaecellsandproto...     

不规则框架结构的组合隔震反应分析

为研究不规则框架隔震结构的地震反应,分别对一个传统抗震结构、一个铅芯叠层橡胶支座隔震结构和四个组合隔震结构(隔震层由铅芯支座和滑板支座组成)进行了弹塑性地震反应时程分析,研究隔震支座参数对隔震效果的影响。结果表明:采用组合隔震技术时,合理选择隔震层的铅芯支座布置位置、滑板支座的摩擦系数和铅芯叠层橡胶支座的型号,可以有效地降低上部结构的扭转效应;对于不规则的建筑隔震结构,为减小地面运动带来的扭转效应,建议采用由铅芯支座和滑板支座组合而成的隔震层,可对上部结构的扭转起到很好的抑制作用。     

导管架式海洋平台结构阻尼隔振体系及其减振效果分析

导管架式海洋平台结构是当前应用最广的一种平台结构形式。本文研究导管架式海洋平台结构阻尼隔振体系及其减振效果。针对导管架式海洋平台结构的型式与特点，为了充分发挥阻尼器的耗能减振作用，提出了在平台结构导管架端帽和甲板之间设置柔性阻尼层的新型阻尼隔振方案。针对渤海JZ20－2MUQ平台结构，建立了海洋平台结构阻尼隔振体系简化计算模型，研究了隔振层参数与结构阻尼比的关系以及它们对结构整体和隔振层层间相对位移的控制效果；进行了多种冰荷载工况和地震工况的数值模拟。结果表明，阻尼隔振方案是导管架式海洋平台结构的一种有效的减振措施。     

地缘经济背景下的老挝橡胶林地扩张监测及其影响研究综述

20世纪90年代以来,在全球橡胶市场和地缘经济合作机制的影响下,作为中南半岛唯一的内陆国家,老挝正在经历以橡胶林扩展种植为主导的土地覆被/土地利用变化(LCLUC)。橡胶扩展种植不仅对全球最大的橡胶消费国——中国进口天然橡胶至关重要,其引起的LCLUC也对老挝国内农户社会经济和生态环境造成了深刻影响。本文首先总结了老挝橡胶林种植模式、扩展机制和发展潜力,其次回顾了老挝橡胶扩展种植相关研究进展及橡胶林遥感方法研究进展。综述表明：老挝境内橡胶林种植模式、适宜性空间评价、遥感监测、社会经济与生态环境影响评估研究,总体上仍处于起步阶段。迄今,有关老挝全国层面的橡胶林种植和扩展地理分布及时空变化信息仍非常缺乏,同时橡胶林种植与快速扩展对农户生计和自然环境(水土流失、水源涵养和生物多样性等)影响尚缺乏系统研究,这也是未来需要优先关注的研究方向。本文有助于更好地理解老挝橡胶林扩展特征及其社会与环境影响,既可为指导老挝橡胶种植业有序良性发展提供科技支撑,也可为中国海南与云南等省橡胶发展提供借鉴。