Population dynamics,age structure and sex ratio of the bromeliad-dwelling jumping spider,Psecas chapoda (Salticidae)

In this study, the population fluctuations, phenology and sex ratio of the bromeliad-dwelling jumping spider Psecas chapoda were investigated in an area of semi-deciduous forest in south-eastern Brazil. Psecas chapoda occurred and reproduced on Bromelia balansae (Bromeliaceae) throughout the year. The number of egg sacs increased at the beginning of the rainy season (September to December), but the population size and phenology were stable over time and correlated weakly with rainfall and temperature. The principal factor affecting the dynamics of P. chapoda was the blooming of B. balansae, which expelled spiders because of the drastic change in plant architecture. Male spiders were more frequent than females during the juvenile phase, whereas females were more frequent than males during the subadult and adult phases, suggesting a sex ratio that favoured males. The biotic and abiotic factors that influence the population dynamics and sex-dependent vulnerability determination are discussed.     

Setal diversity,trophic modes and functional morphology of feeding appendages of two callianassid shrimps,Callichirus major and Sergio mirim (Decapoda: Thalassinidea: Callianassidae)

In the present study we investigate the trophic behaviour, stomach content and morphology of the feeding appendages, with emphasis on setae, of two callianassids; a generalist feeder, Callichirus major (Say, 1818) and a strict deposit feeder, Sergio mirim (Rodrigues, 1971). Of the 87 setal types described, only 5% were common to both species. Setal types were clustered in four main categories; plumed, serrate, plumodenticulate and simple. Callichirus major has higher setal diversity than S. mirim. Relative to the amount of setal types present in each species, C. major has a higher ratio of serrate to plumodenticulate setal types and similar percentages of plumed and simple setae. Examining the setae and spatial position of the segments of the feeding appendages, it is possible to infer that the main function of the dactyli, propodi and basal endites is to brush particles, while the meri, ischia and coxal endites retain sediment. The setal diversity found on the feeding appendages reflected the diverse trophic strategies of the callianassid species studied. Exclusive deposit feeders, e.g. S. mirim, appear to have fewer setal types than generalist feeders, e.g. C. major. Apparently, the higher ratio of serrate to plumodenticulate setal types in Callianassidae depends more on the necessity to triturate particles prior to ingestion than on the trophic mechanism used by the species.     

斗轮取料机结构强度分析

本文以3000t/h斗轮取料机作为计算模型,依据《移动式松散物料连续装卸设备第1部分：结构设计规则》（ISO 5049-1-1994）,针对不同工况建立了ANSYS有限元模型,并对其进行分析计算,得出了各工况下的应力分布等结果,为优化设计提供了参照依据。     

浅析虚拟学习社区归属感

网络环境下的虚拟学习社区包含网络环境和学习共同体两个要素,学习共同体中的学习者更是虚拟学习社区的核心。目前虚拟学习社区的建设重在构建网络环境和丰富学习资源,极少关注学习者在网络学习过程中的情感体验,导致学习者归属感缺失,使得虚拟学习社区学习绩效低下。     

浅析现代板式家具的特点

现代板式家具式样繁多，对其优缺点进行概括分析，有利于设计师、企业生产者对产品进行更好的定位。     

高层建筑结构设计课程教学改革

介绍了在高层建筑结构设计课程教学中进行的改革方法。在教学中重视结构的概念设计、调整教学内容、增加常用软件的教学,并把课程教学与毕业设计相结合,进行了毕业设计内容改革。通过这些教学改革,使学生对课程有了更好的理解,为今后的实践工作打下了坚实的基础。     

中小企业融资结构与企业成长——以我国中小上市公司为样本

采用Z值模型衡量中小企业存在的融资风险,实证研究中国中小上市公司融资结构与成长性的关系。实证结果表明,当Z>2.4时的中小上市公司即债务融资风险小的公司,这些公司的融资结构与成长性显著正相关,这些公司适合采用债务融资;而当Z<2.09时的中小上市公司即债务融资风险大的公司,这些公司的融资结构与成长性显著负相关,这些公司不适合采用债务融资。     

Action Research for Sustainable Water Futures in Western Sydney: Reaching Beyond Traditional Stakeholder Engagement to Understand Community Stakeholder Language and Its Implications for Action

Action on issues of ecological significance often requires changes in personal behaviour and political consensus on technologies to support these changes. Unfortunately, many consultation processes only engage a narrow range of stakeholders, usually those professionally engaged or already active on a range of community issues. This paper illustrates how people who are ‘hard to reach’ or seen as ‘apathetic’ might be engaged using ‘action-conversations’ that explore the social climate for action and how scientific/technical messages can be framed in the language of the community.     

单螺杆油气混输泵螺杆-衬套副结构参数的优选

对影响单螺杆油气混输泵螺杆-衬套副的性能和寿命的各种因素(如过流面积、密封腔的压力变化规律、相对滑动速度、螺杆转动惯性力、压缩比等)及其随结构参数的变化规律进行了全面的理论分析。通过对单项指标的分析,结合现有单螺杆油气混输泵的设计和安装必须满足的结构条件,推荐了综合考虑多项指标时结构参数的优选方法,得到了结构参数的优选图解。所得的结果对单螺杆油气混输泵的设计具有一定意义。     

双梁门式起重机结构分析中的若干问题及程序研制

本文对梁门式起重机结构设计中的几个棘手问题进行了探讨和分析,提出解决方法.在此基础上编制“GCSA”软件,并成功地用于系列产品设计.