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421.
以玫瑰无须鲃(Puntius conchonius)胚胎为试验材料,通过胚胎的存活率、半致死浓度(LC50)以及胚胎发育过程中的形态学变化等来评价壬基酚(nonylphenol,NP)对玫瑰无须鲃胚胎发育的影响.结果表明,壬基酚对胚胎的影响主要表现在胚胎发育的早期与晚期;壬基酚对胚胎的LC50随着壬基酚对胚胎作用时间的减少而增加,从卵裂期(2~4细胞期)开始染毒到孵化期的LC50为(7.55±0.22) μmol/L,而从成体节期染毒到孵化期的LC50为(10.77±0.08) μmol/L.壬基酚对玫瑰无须鲃胚胎不同发育阶段的影响程度不同,其中最敏感的阶段为成体节期,其次为卵裂期与囊胚期,较不敏感的为原肠胚期.玫瑰无须鲃胚胎对壬基酚毒性反应的主要变化特征为卵凝结、脊椎畸形以及胚胎发育延迟.研究表明,壬基酚对玫瑰无须鲃胚胎的发育具有明显的毒性效应,而鉴于玫瑰无须鲃胚胎对壬基酚的较高敏感性,可将玫瑰无须鲃胚胎作为评价壬基酚对胚胎发育毒性的一种理想模型. 相似文献
422.
本文结合鞋靴保暖功效学原理,重点研究了支撑式鞋垫和橡胶双密度胶底结构。通过实验确定了鞋底发泡层视密度的范围在0.75g/cm3~0.85g/cm3之间,发泡橡胶的拉伸和导热性能达到平衡,兼顾了保暖鞋的耐穿和防寒隔热性能。 相似文献
423.
Toward Integrated Environmental Management for Challenges in Water Environmental Protection of Lake Taihu Basin in China 总被引:5,自引:3,他引:2
Lake Taihu is the third largest freshwater lake in China. It serves many social, economic, and ecological purposes in the
drainage basin. Unfortunately, the water has been heavily polluted due to rapid industrialization and urbanization during
the last two decades. Notwithstanding great efforts made so far to improve the water quality, the environmental situation
is still far from being optimistic. The basin and the lake are facing a range of severe environmental challenges: rapid socio-economic
development continues to place great pressures on the environment, current pollution control projects have many problems from
the viewpoint of effectiveness and efficiency of their implementations, and the non-point sources of pollution such as agricultural
fields, for which control is more difficult than for industrial point sources, have become the main contributors to serious
eutrophication of the lake. Considering the characteristics of the environmental challenges and problems confronting the basin
and the lake, we focus on integrated environmental management (IEM) as a promising and effective approach to overcome these
predicaments. Current practices and problems of environmental management in the basin are examined, and potential future developments
are discussed. Three aspects of the IEM are emphasized: institutional cooperation, public participation, and internalization
of environmental externalities. We think these are the most critical for not only the basin but also for the whole of China
to achieve a sustainable society. 相似文献
424.
425.
为解决长江流域生态环境治理模式中“权力—权利”主体间存在的结构性冲突,《长江保护法》以专门立法的形式对流域生态环境法律体系进行了统合性建构,创设出“环境公权机关统筹主导+环境私权主体竞相参与”的长江流域生态环境协同规制的新模式。该模式的塑造既有对构建我国现代环境治理体系这一顶层设计的积极遵循,也适配于社会性规制力量蓬勃发展的客观趋向,符合“成本—效益分析”视野下流域生态环境治理成本最小化的价值追求。以对长江流域生态环境治理法律秩序的高度统摄为依归,长江流域生态环境协同规制模式一方面沿循从“宏观宣示”到“微观赋权”的渐进性立法表达路径,对国家权力统筹主导流域治理的地位进行了立法诠释;另一方面也对社会力量多元参与流域治理的功能配置与职责序构作了妥善且周延的法律安排。在学理上,可从形式、理念与要素三重维度内容出发,对长江流域生态环境协同规制模式的法律意涵予以明晰。 相似文献
426.
427.
Zeng Xiang Xu Xijin Qin Qilin Ye Kai Wu Weidong Huo Xia 《Environmental geochemistry and health》2019,41(1):309-321
Environmental Geochemistry and Health - The purpose of this study was to investigate the associations between levels of lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn) in the PM2.5 and... 相似文献
428.
Wenjun Qin Manuel Dekermenjian 《Journal of the Air & Waste Management Association (1995)》2013,63(8):1177-1183
Abstract Loss of filtration efficiency in a fabric filter baghouse is typically caused by bag failure, in one form or another. The degree of such failure can be as minor as a pinhole leak or as major as a fully involved baghouse fire. In some cases, local air pollution regulations or federal hazardous waste laws may require estimation of the total quantity of particulate matter released to the environment as a result of such failures. In this paper, a technique is presented for computing the dust loading in the baghouse exhaust when one or more bags have failed. The algorithm developed is shown to be an improvement over a previously published result, which requires empirical knowledge of the variation in baghouse pressure differential with bag failures. An example calculation is presented for a bag-house equipped with 200 bags. The prediction shows that a small percentage of failed bags can cause a relatively large proportion of the gas flow to bypass the active bags, which, in turn, leads to high outlet dust loading and low overall collection efficiency from the baghouse. 相似文献
429.
Li Dan Bi Ran Chen Hongxing Mu Lei Zhang Lina Chen Qin Xie Haibo Luo Yongju Xie Lingtian 《Environmental science and pollution research international》2017,24(30):23872-23879
Environmental Science and Pollution Research - Risk assessing newly synthesized chemicals prior to their applications is extremely important, if we want to ensure substitution of risky chemicals... 相似文献
430.
针对标准SY/T6477-2000和标准API RP579-2007 中腐蚀缺陷管道评价判据问题,研究了标准中各项判据及其算法,计算了不同评价标准对于同一腐蚀缺陷的评价结果,并对比分析了不同参数变化情况与评价结果保守性关系。结果表明,不同评价标准所得的缺陷管道判据参数值之间存在差异,即各评价标准的保守性不同,不同评价标准适用于不同的均匀腐蚀或局部腐蚀缺陷管道情况。以此有效防止使用标准时造成差错,同时为今后相关标准的修订尽可能提供有益的帮助。 相似文献