北京雾霾现象与机动车尾气排放关系分析

北京雾霾天气的成因存在争议。政府公布的结论是,20-30％的污染是来源于汽车尾气排放,但这是与事实相冲突的。本文主要讨论机动车尾气排放在雾霾成因中的实际比例,及可能解决的方案。     

国际对华投资热衷环保领域的喜与忧

近期,国际对华投资空前一致地转向了环保领域。这一现象把资金与环保捆绑在一起,冲击了人们的视线。 在国际对华投资大幅增长无望的情况下,众多资金输出国却对中国的环保市场投注了极大热情。这些资金的注入将有助于中国环保事业的发展,从长远来看,还将有助于全球环境的改善。但是很显然,国际对华环保投资也是跨国环保集团占领中国市场的一种策略。就这一点,引起了分析人士的担忧。     

大气腐蚀起始过程中的微液滴现象研究

微液滴现象是一种新发现的实验现象,当易被腐蚀的金属表面上预先形成有腐蚀性主液滴时,在合适的条件下,主液滴的周围有更小的微液滴出现并不断扩展.微液滴的形成和扩展遵循一定的规律,并与大气腐蚀起始过程密切相关.电化学极化结果显示,大气腐蚀过程中的腐蚀电流是微液滴形成和发展的推动力.     

"污染受害者法律帮助中心"现象解读

1999年11月，中国政法大学环境法学教授王灿发带领一群志愿者，开办了国内第一家专为污染受害者提供帮助的法律援助中心，为许多求助无门的环境污染受害者提供帮助，免费为无力支付诉讼费、律师代理费的污染受害者打官司，并开通了帮助热线（010）62267459。     

Plant invasion phenomenon enhances reproduction performance in an endangered spider

Current models in evolutionary ecology predict life history alterations in response to habitat suitability to optimize fitness. Only few empirical studies have demonstrated how life history traits that are expected to trade off against each other differ among environments. In Europe, many salt marshes have been recently invaded by the grass Elymus athericus. Previous studies however showed higher densities of the endangered spider Arctosa fulvolineata (Araneae: Lycosidae) in invaded salt marshes compared to natural habitats, which suggests a lower habitat suitability in the latter. The aim of this study was to determine if this emerging habitat (1) affects the amount of resource acquisition and (2) alters the balance between life history traits that are expected to trade off against each other in this stenotopic salt marsh species. As suggested by theoretical studies, an optimization of fitness by increasing egg size at the cost of decreasing fecundity in unsuitable (i.e., natural) habitats was expected. Females presenting cocoon were then collected in close invaded and natural salt marsh areas within the Mont Saint-Michel Bay (France). By considering female mass as covariate, cocoon mass, number of eggs, and egg volume were compared between both habitats. Clutch mass was strongly determined by female mass in both habitats. Clutch mass was however significantly smaller in the natural habitat compared to the invaded habitat, indicating a higher resource acquisition in the latter. When correcting for female size, fecundity was additionally increased in the invaded habitat through a significant decrease in egg size. This phenotypic response can be explained by differences in habitat structure between invaded and natural habitats: the former offers a more complex litter favoring nocturnal wanderers like A. fulvolineata. The existence of such an adaptive reproduction strategy depending on habitat suitability constitutes an original case of an invasion that favors an endangered species.     

Altai pika (<Emphasis Type="Italic">Ochotona alpina</Emphasis>) alarm calls: individual acoustic variation and the phenomenon of call-synchronous ear folding behavior

Non-hibernating pikas collect winter food reserves and store them in hay piles. Individualization of alarm calls might allow discrimination between colony members and conspecifics trying to steal food items from a colony pile. We investigated vocal posture, vocal tract length, and individual acoustic variation of alarm calls, emitted by wild-living Altai pikas Ochotona alpina toward a researcher. Recording started when a pika started calling and lasted as long as possible. The alarm call series of 442 individual callers from different colonies consisted of discrete short (0.073–0.157 s), high-frequency (7.31–15.46 kHz), and frequency-modulated calls separated by irregular intervals. Analysis of 442 discrete calls, the second of each series, revealed that 44.34% calls lacked nonlinear phenomena, in 7.02% nonlinear phenomena covered less than half of call duration, and in 48.64% nonlinear phenomena covered more than half of call duration. Peak frequencies varied among individuals but always fitted one of three maxima corresponding to the vocal tract resonance frequencies (formants) calculated for an estimated 45-mm oral vocal tract. Discriminant analysis using variables of 8 calls per series of 36 different callers, each from a different colony, correctly assigned over 90% of the calls to individuals. Consequently, Altai pika alarm calls are individualistic and nonlinear phenomena might further increase this acoustic individualization. Additionally, video analysis revealed a call-synchronous, very fast (0.13–0.23 s) folding, depression, and subsequent re-expansion of the pinna confirming an earlier report of this behavior that apparently contributes to protecting the hearing apparatus from damage by the self-generated high-intensity alarm calls.     

城市的记忆--工业废弃地更新、改造浅析

针对在城市发展中出现的工业废弃地的问题,文章立足于城市的更新、改造,结合当今国内外城市工业废弃地更新、改造的实践,从城市历史文化的角度,对工业废弃地的更新、改造的理论和方法在宏观和微观两个层面进行了分析和探讨.