高地应力软岩隧道初期支护优化研究*

为研究边墙曲率、支护参数等因素对高地应力软岩隧道变形控制的效果,以大瑞铁路营盘山隧道为工程背景,结合现场监测数据,建立有限元模型,分析不同边墙矢跨比及初期支护参数对隧道变形的影响,借此得到合理的初期支护参数。结果表明:原有支护结构中“直边墙”对于隧道水平方向变形与压力抵抗能力较弱,当边墙曲率调整至0.12后,支护结构的受力和变形情况得到明显改善;初期支护参数中锚杆参数对于隧道变形控制效果较小,增强衬砌的强度可以有效控制隧道的变形;通过围岩-支护特征曲线对优化后的支护方案进行安全评价,发现其安全性能较之前显著增强,现场应用结果也表明支护结构并未出现破坏失稳现象,隧道变形得到有效控制。研究结果对类似工程变形控制及支护方案优化提供一定的参考依据。     

考虑行为特征的人群疏散模拟研究*

为研究聚集活动中的行人在移动过程中所表现出的行为特征对人群整体移动过程的影响,通过实验观察与计算机仿真模拟的方法对人员移动进行研究。通过对实验视频的观察分析,在CTM模型基础上建立考虑人员跟随行为与保持距离行为特性的移动模型,并在简单无障碍和复杂多障碍的场景进行仿真实验。结果表明:模型能有效地描述行人的运动特征,而且拥挤程度和行人间排斥作用越大时行人移动越慢,整个疏散过程花费时间越长;障碍物的存在会影响人群在出口处的“成拱现象”,对理解人员的运动规律和防止拥挤踩踏事故具有一定理论和现实意义。     

加载条件下不同埋深原水管道受力特征模型试验*

为探究不同埋置深度对原水管道影响,利用缩尺模型对不同埋深条件下原水管道受力特征进行分析,综合研究管道外径、管道埋深、加载值和加载方式等因素对管道受力影响。结果表明:中心加载条件下,随管道埋深增加,管道应力呈先增大后减小趋势,当埋深厚度与管径比值为3时,管道应力达到最大,土拱效应开始显现;偏心加载条件下,埋深厚度增大使管道应力不断增加,但后期管道应力增长率小于前期;相同埋深厚度条件下,中心加载与偏心加载条件下,同截面管底处应力值相对最大。研究结果可为不同埋深区域内原水管道维护运营提供指导。     

曝气生物滤池中碳和氮代谢特性

用充填陶瓷滤料的曝气生物滤池研究碳和氮代谢特性。曝气生物滤池进水氨氮为52mg／L左右、COD为100mg／L左右和回流比为200％时,经过20多d的运行,出水氨氮小于0．05mg／L、COD小于25mg／L、亚硝态氮为4．7mg／L和硝态氮为7．1mg／L,COD去除率达75％,氨氮去除率达99．9％,总氮去除率达78％;过大和过小的回流比对曝气生物滤池的运行性能都是不利的。研究成果可以应用于一般城市污水以及含低COD、高氨氮工业废水的处理。     

高校财务价值链管理的特征分析与内容

在价值链概念的基础上提出高校财务价值链的特征和内容．通过如何在资金筹集价值链、资金运用价值链和资金调控价值链三个环节实现价值增值，为适时地调整高校的财务战略，合理地进行财务资源配置服务．     

Ecological and hormonal correlates of antipredator behavior in adult Belding’s ground squirrels (Spermophilus beldingi)

Predator–prey relationships provide an excellent opportunity to study coevolved adaptations. Decades of theoretical and empirical research have illuminated the various behavioral adaptations exhibited by prey animals to avoid detection and capture, and recent work has begun to characterize physiological adaptations, such as immune reactions, metabolic changes, and hormonal responses to predators or their cues. A 2-year study quantified the activity budgets and antipredator responses of adult Belding’s ground squirrels (Spermophilus beldingi) living in three different California habitats and likely experiencing different predation pressures. At one of these sites, which is visually closed and predators and escape burrows are difficult to see, animals responding to alarm calls remain alert longer and show more exaggerated responses than adults living in two populations that likely experience less intense predation pressure. They also spend more time alert and less time foraging than adults at the other two sites. A 4-year study using noninvasive fecal sampling of cortisol metabolites revealed that S. beldingi living in the closed site also have lower corticoid levels than adults at the other two sites. The lower corticoids likely reflect that predation risk at this closed site is predictable, and might allow animals to mount large acute cortisol responses, facilitating escape from predators and enhanced vigilance while also promoting glucose storage for the approaching hibernation. Collectively, these data demonstrate that local environments and perceived predation risk influence not only foraging, vigilance, and antipredator behaviors, but adrenal functioning as well, which may be especially important for obligate hibernators that face competing demands on glucose storage and mobilization.     

The relationship between dewlap size and performance changes with age and sex in a Green Anole (Anolis carolinensis) lizard population

Ornaments are believed to signal an individual's ability to reproduce successfully and/or survive. Since an individual's fitness is often influenced by multiple traits (e.g. number of copulations, ability to acquire nest sites or to escape predators), which are difficult to quantify simultaneously, we examine performance traits (bite force, jumping performance) believed to be relevant to an individual's fitness. Specifically, we ask whether variation in dewlap size is related to variation in body size, bite force and jumping ability in the lizard Anolis carolinensis. Our results show that dewlap size is correlated with jumping capacity across all individuals, whereas the relationships between dewlap size, body size and bite force differ depending on sex/age class. We argue that selection against relatively large dewlaps at the transition between small mature and large mature males might be responsible for the lack of a relationship within large males. The absence or presence of a correlation between dewlap size and bite force, on the other hand, might be explained by differences in behaviour, such as territory establishment, anti-predator tactics, and/or mate choice. Our work thus suggests that selective forces influencing the evolution of ornaments may operate differently on different sexes and life-history stages.     

Non-invasive measurement of the physiological stress response of wild rabbits to the odour of a predator

Summary. Stress has been widely studied in different mammals, but the physiological stress reaction that the odour of a predator could induce in preys has not received much attention. Besides, not all the animals would respond to the same extent to a known stressor. We developed an experimental procedure with eleven na?ve European rabbits (Oryctolagus cuniculus) in order to determine the individual physiological response to the olfactory detection of a potential predator. The rabbits were housed singly in small enclosures with a concrete burrow system and food and water were available ad libitum. The animals followed a control trial, without odour, and an experimental trial where we confronted the rabbits with fox (Vulpes vulpes) odour. Furthermore, another sample of eleven rabbits followed a control procedure subjected to the same housing and handling procedures but without facing the predator odour. In order to assess the physiological response we analysed the concentration of glucocorticoid metabolites in the faeces of the rabbits. Therefore, everyday faecal samples were collected and analysed with an enzyme immunoassay in order to measure the corticosterone metabolites (CM), particularly, those metabolites with a 5α-3β, 11β-diol structure. After validating the assay for wild rabbits, we found that the simulated presence of a predator (fox odour) in the enclosure resulted in an increase in faecal CM concentrations. However, the stressor did not affect all the animals in the same way. We found a general increase in the individual differences. In particular, males experienced a higher increase than females, though the overall response was similar for both sexes. To our knowledge this is one of the first attempts to analyse the assessment of the risk of predation by means of non-invasive methods.     

广东省土壤肥料技术推广体系创新的思考

总结了广东省20多年来土壤肥料技术推广工作的成绩，阐述了土壤肥料技术推广工作的特点，提出了广东省土壤肥料技术推广体系创新的思路。     

南岳珍稀濒危植物的调查研究

在南岳野生植物中,珍稀濒危植物主要是指国家级保护植物,共有13种,其中一级2种,二级11种,它们是金钱松Pseudolarix amabilis (Nelson) Rehd.,篦子三尖杉Cephalotaxus oliveri Mast.,南方红豆杉Taxus chinensis (Pilger) Rehd.var.mairei (Lemeé et Lévl.) Cheng et L.K.Fu,榉树Zelkova Schneideriana Hand.-Mazz.,樟树Cinnamomum camphora (L.) Presl,闽楠Phoebe bournei (Hemsl.) Yang,伯乐树Bretschneidera sinensis Hemsl,绒毛皂荚Gleditsia.japonica Miq.var. velutina L.C.Li,野大豆Glycine soja Sieb. et Zucc.,花榈木Ormosia henryi Prain,毛红椿Toona sinensis (A.Juss.) Roem.var.pubescens (Franch.) Hand.-Mazz.,喜树Camptotheca acuminata Decne.,以及香果树等,本文主要介绍他们的分类位置、形态特征和地理分布状况,分析了它们的区系特征,提出应该尽快建立南岳国家级野生保护植物的核心或者优先保护地段、建立珍稀濒危植物的地理信息系统、研究其生物学和生态学特性以及采取就地或迁地保护措施来保存等对策.