混凝土锈胀开裂的抑制措施

钢筋锈蚀是影响混凝土结构耐久性最重要的因素。钢筋锈胀体积膨胀,对周围混凝土产生压力,继而导致保护层的受拉开裂,出现锈胀裂缝,这对结构整体的安全性和耐久性十分有害。研究混凝土锈胀裂缝的抑制措施,对提高结构的耐久性具有重要意义。从结构构造入手,以快速通电加速纵向钢筋锈蚀的方法,研究了混凝土保护层厚度和箍筋间距对混凝土构件锈胀开裂的影响;同时通过计算机仿真,对试验构件进行了数值试验。在此基础上,建立了构件表面应力与混凝土保护层厚度及箍筋间距的相关关系,得到了不同保护层厚和箍筋间距对试件表面锈胀裂缝的影响规律。     

沿海滩涂围垦生态补偿标准构建——基于能值拓展模型衡量的生态外溢价值

论文综合利用能值分析法、生态足迹法等生态经济学方法,结合Shannon-Wiener指数和生态消费系数构建了沿海滩涂围垦生态补偿能值拓展模型以测算滩涂在各时期的生态外溢价值,并以生态外溢价值改变量作为滩涂围垦生态损害的衡量标准,且以此为生态补偿依据,在生态价值系数调整法的基础上建立了沿海滩涂围垦生态补偿标准。最后以杭州湾新区为例,测算了该区域滩涂围垦过程中各年份生态补偿标准,结果显示,2000—2015年,该区域生态补偿标准从2000年0美元/m²平缓递增到2015年0.05美元/m²。此研究表明,能值拓展模型能有效弥补传统的基于生态服务价值模型的一些不足,使评估标准相对客观化,评估结果动态化和体现对补偿主客体双方意愿的尊重。     

乙酸钠为碳源时进水COD和总磷对生物除磷的影响

研究了乙酸钠为碳源时,乙酸盐和总磷浓度对循序间歇式生物除磷工艺运行效果的影响,以及含高浓度乙酸盐废水不能有效除磷的原因结果表明:COD<600mg·L^-1时,随着COD/TP值的增大,总磷去除率提高,COD/TP<50时,磷的去除率提高显著,但当COD/TP>50时,磷的去除变化不大;进水乙酸盐浓度过高(COD>600mg·L^-1)使除磷效率逐渐下降,COD>1000 mg·L^-1会使生物除磷系统完全崩溃;研究发现除磷效率的下降是由于过多的乙酸盐从厌氧段进入了好氧段,引起丝状菌的增殖、污泥膨胀,导致聚磷菌被洗出.     

云南地震死亡人数定量估算

本文给出了多震区的地区性指数，并通过分析龙陵地震前的预报、警报、强烈有感前震在减轻伤亡中的作用和通海地震伤亡达到最重的实例，提出了人口户外率的概念。     

污水处理场运行的改进与优化

从荆门石化污水处理场的改扩建入手，分析了投用后存在的主要问题，针对隔油、浮选、生化各单元的运行进行了改进与优化     

上海PRED的系统分析及调控指标研究

在对上海ＰＲＥＤ研究中，建立ＰＲＥＤ系统因子模型，以１９７８－１９９５年的数据为基础，计算了上海ＰＲＥＤ系统７个因子间的相关系数列出相关矩阵，据此分析了该时期内多因子的演变及其相关性，得出了系统的各因子演变显著的不同步性和单因子演变无规律的跳跃性特征，认为环境与经济是上海ＰＲＥＤ系统有效调控关键，经济发展总量的改善和积极管理可以缓解人口等因子的制约作用。     

阿拉善地区生态环境问题及探讨

阿拉善荒漠地处我国西北内陆，亚洲荒漠区最东部，总面积27万平方公里。由于所处的特殊地理位置，阿拉善荒漠植被，历来成为甘肃河西走廊、宁夏平原和内蒙古河套平原三大绿洲的天然保护屏障。然而，阿拉善地区的生态环境日趋恶化，气候干旱、沙尘暴频繁、黑河下泻水量锐减，水资源危机，造成湖泊干涸，地下水位下降，水质恶化，土地盐渍化加重。成为我国沙尘暴主要尘源地区之一。植被严重衰退，生物多样性减少。草地面积缩小，保护功能强大的乔、灌、草植被，每年以2万亩的速度减少消失。绿洲萎缩，濒临消亡，濒危物种亟待抢救。沙漠化面积扩大，吞并草场，埋没农田。每年以1000平方公里速度扩张，沙进人退现象加重，生态难民增多。著名的巴丹吉林，腾格里，乌兰布和三大沙漠向前推进，倾入黄河，阻断公路、铁路、吞食盐场，直接经济损失巨大。阿拉善的生态危机和居延绿洲的严重衰退，直接影响到国防和航天建设。也威胁到了相邻省区以及黄土高原的工农业生产，甚至波及到华北、西北，以及更远的江淮地区。本地区的生态环境问题，已不是区域性的环境问题。是全社会、全民族的问题，已引起国家及各部门的高度重视。     

Modeling the brown bear population in Slovenia: A tool in the conservation management of a threatened species

In this paper, we address three aspects of the brown bear population in Slovenia: its size (and its evolution over time), its spatial expansion out of the core area, and its potential habitat based on natural habitat suitability. Data collected through measurement/observation of the bear population and from the literature are used. A model is developed for each aspect. The results are estimates of population size, a picture of the spatial expansion of the population and maps of its optimal and maximal potential habitat (based on natural suitability). Overall, the brown bear population has been increasing since the establishment of a core protective area and has been expanding outside this area. The habitat suitability maps show that there is room for further expansion. Based on habitat suitability and bear population density, as well as human activity and current damage reports, we recommend that the Alps should be temporarily kept free of the bears, until the necessary mitigation measures regarding human–bear conflicts are carried out. On the other hand it is of crucial importance to adapt human activities and improve bear management in the optimal habitat, with which the goals of successful conservation of the species might be achieved.     

The effects of castration, sex ratio and population density on social segregation and habitat use in Soay sheep

We analysed 16 years of census data gathered on the island of Hirta (archipelago of St. Kilda) to investigate the effects of castration, population density, sex ratio, season and group type on habitat use and social segregation of Soay sheep. From 1978 to 1980, 72 male lambs were castrated. We used this experiment to study how a change in reproductive status could affect sociality and habitat choice of these males. Males, females and castrates were all segregated outside the rutting season in autumn. Castrates were the least segregated from females in spring and summer but were most segregated from them during the pre-rut. The more equal the sex ratios, the higher was the degree of social segregation. The three sex classes used similar habitat types, namely, Holcus agrostis, Agrostis festuca and Calluna habitats. Holcus agrostis and Agrostis festuca were top- and second-ranked in female and castrate habitat use, while Holcus agrostis and Calluna were the two top habitat types used by rams. It is unclear why males included Calluna heath habitats, but it cannot be excluded that they might have shifted their use depending on forage availability. A lack in differences in habitat use between castrates and females suggests that body size differences alone cannot be the driving factor for habitat segregation in male and female Soay sheep and that there are reasons other than body size that could motivate reproductive males to use additional habitat types, such as Calluna heath. Although habitat use shifted from one habitat type to the next between low- and high-population-density years and between seasons, there was no clear link between population density and how different groups (male, female or castrate) used these areas. We discuss effects of reproductive status, population density and sex ratio on social segregation and habitat use and suggest that these factors need to be taken into account when investigating causes of sexual segregation in ungulates.     

Population differentiation in female sex pheromone and male preferences in a solitary bee

Population differentiation in female mating signals and associated male preferences can drive reproductive isolation among segregated populations. We tested this assumption by investigating intraspecific variation in female sex pheromone and associated male odour preferences among distant populations in the solitary bee Colletes cunicularius (L.) by using quantitative gas chromatography and by performing field bioassays with synthetic blends of key sex pheromone compounds. We found significant differences in sex pheromone blends among the bee populations, and the divergence in odour blends correlated positively with geographic distance, suggesting that genetic divergence among distant populations can affect sex pheromone chemistry. Our behavioural experiments, however, demonstrate that synthetic copies of allopatric female sex pheromones were cross-attractive to patrolling males from distant populations, making reproductive isolation by non-recognition of mating signals among populations unlikely. Our data also show that patrolling male bees from different populations preferred odour types from allopatric populations at the two sites of bioassays. These male preferences are not expected to select for changes in the female sex pheromone, but may influence the evolution of floral odour in sexually deceptive orchids of the genus Ophrys that are pollinated by C. cunicularius males.