Diel changes in vertical overlap between Cyclops strenuus (Copepoda; Cyclopoida) and its prey in oligotrophic Lake Toya, Hokkaido, Japan

The vertical distribution of Cyclops strenuus and its prey, and the gut contents of C. strenuus were investigated at 3 h intervals over 24 h periods in the pelagic area of oligotrophic Lake Toya in May, August and October 1992. C. strenuus showed slight diel vertical migration (DVM) in May, but did not migrate and was always distributed below 15 m in August and October, the thermally stratified period. This suggests that the DVM is strongly influenced by the development of the thermocline, which the copepod may not be able to cross. Gut content analyses revealed that in Lake Toya it is omnivorous, and that the dominant prey are cladocerans and Filinia longiseta. The number of prey remains in the gut varied with time, and the diel changes did not follow changes in prey density that take the vertical overlap between predator and prey into account. We argue that very low prey density associated with the oligotrophic nature of the lake would mask the relationship between prey density and the number of prey in the gut of the predator.     

列控车载设备日常维护与故障处理

本文概要介绍了CTCS2—200H列控车载设备，并就设备的日常维护、演练和故障处理等方面提出了自己的看法。     

移居高原罹患矽肺矿工20年心血管X线改变的动态观测

选择移居2500m高原63名矽肺矿工，连续20年摄后前位胸片，按居住年限分组，自身对照，观察矽肺与肺动脉高压的演变过程．分析矽肺X线心血管4项指标的改变。结果表明：动态观察矽肺X线及心血管各指标的改变，对预测高原人体矽肺的发生，评定矽肺的发展程度，观察疗效和对矽肺愈后判定有着非常重要的临床应用价值。     

碳迁移对T91／12Cr1MoV异种钢管接头持久强度的影响

用焊接热模拟方法确定了焊后热处理工艺参数，通过选择９％Ｃｒ和５％Ｃｒ的焊材，研究了接头熔合区碳迁移行为，分析了脱碳层的碳浓度、碳化物类型、分布特征及其对接头持久强度 的影响。     

从客家人的迁徙史看赣南客家山歌的演变与发展

一部客家人由北至南的迁徙史,推动了中原文化由北向南的传播与发展,形成了独具魅力的客家山歌艺术.如同中原母语、沿途方言及本地土语杂交融合形成的客家山歌语言一样,客家山歌的音调亦是中原音韵与沿途各地音乐元素结合本地土音变异的结果.在客家人历次大迁徙中,以兴国山歌为代表的赣南客家山歌,一方面顽强地坚守和传承中原祖居地古乐音韵的遗风,另一方面又不可避免地经历着与沿途客居地文化的碰撞、浸淫与融合,衍生新的文化变异.     

Socio-ecological Mobility: A Research Strategy for a New Coastline

Abstract

Persistent development, population pressures, and increasing natural hazards are unequivocally changing socio-ecological systems in the coastal zone. This essay provides direction and initiates scientific dialog on the potential role of mobility in adapting to natural and social changes in coastal environments. The essay identifies four key research areas on information needed to develop coastal management actions and policies that support and recognize socio-ecological coupling in coastal areas. The proposed research includes: (1) modeling localized scenarios that illustrate the tradeoffs associated with various sea level rise adaptation, (2) assessing and consolidating mobility terminology for different applications and contexts, (3) developing solutions to synchronize the co-migration of natural environments and built infrastructure, and (4) evaluating existing or creating new transparent, equitable, and sustainable policies and incentives to support socio-ecological mobility by using case studies and social science methods to understand how people make mobility decisions in different contexts.     

季冻区道路翻浆影响因素分析

从路基冻胀与翻浆产生的现象与作用机理入手,分析季节性冰冻地区产生道路翻浆的原因及影响因素,确定其中土、水、温度是内因,行车荷栽和路面构造是外因,翻浆的产生是它们综合作用的结果,提出具体的防治措施。     

城市居民个人属性与出行方式链相关性分析

首先引出基于活动理论的出行需求预测方法,将活动—出行理论和传统的出行方式相结合,提出出行方式链的概念,并明确出行方式链的两大特性:一致性和转换性;然后阐述城市居民个人属性与出行方式链相关性分析方法,并以2006年4月上虞市的居民出行调查数据为基础,对城市居民个人属性与出行方式链之间的相关性进行实例分析;最后,说明个人属性对出行方式链的选择起着至关重要的作用。     

基于通信线路资源管理系统异构数据迁移的实现

本程序基于通信线路资源管理系统,需要把老系统数据导入新系统中.由于新老系统数据结构不同,且基于WebGIS地理信息系统,数据特殊,数据量大,手工导入数据费时费力,用数据导入软件又不能很好满足本系统导入数据需要.所以需要设计一套可移植性和可操作性较好的程序来进行数据的迁移,能够对老系统的地理信息进行准确处理,从而将有用数据迁移到新系统的数据库中.     

冻融作用下水分迁移对压实黄土强度影响的宏微观试验研究

在季节性冻土区,冻融作用下土体的水分迁移及其伴生现象会诱发黄土路基发生病害,探明冻融作用下水分迁移对压实黄土强度的影响及其机制,对于黄土地区路基工程冻融病害防治非常必要.采用大尺寸设备对洛川黄土开展单向冻结-双向融化作用下的冻融循环试验,对土体温度场、水分场均加以监测,并在此基础上进行直剪试验和电镜扫描试验.结果表明:...