In vitro antioxidant and antibacterial activities of certain 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino}-indolin-2-one derivatives

A new series of 5- or 7-substituted 3-{4-(5-mercapto-1,3,4-oxadiazol-2-yl)phenylimino}-indolin-2-one derivatives were screened for in vitro antioxidant and antimicrobial activities. The results of this study revealed that all synthesized compounds were significantly scavenged DPPH free radicals in a concentration-dependant manner. The IC₅₀ values of all test compounds were found to be between 18.34 and 50.54?µM. All compounds significantly inhibited growth of bacteria and most of the minimum inhibitory concentration values were between 20 and 100?mg?mL^?1 indicating potent to moderate antibacterial activity. In conclusion, 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino)-5 or 7-substituted indolin-2-ones derivatives exhibited moderate antioxidant and antimicrobial activities.     

COAL ASH BASIN EFFECTS (PARTICULATES,METALS, ACIDIC pH) UPON AQUATIC BIOTA: AN EIGHT-YEAR EVALUATION1

ABSTRACT Coal ash effluent effects including particulates, acidic pH excursions, elemental concentrations and bioconcentration in selected organisms have been studied as changes in water quality and densities of benthic macroinvertebrate and mosquitofish (Gambusia affinis) populations in a swamp drainage system over an eight-year period. Three changes in the ash basin settling system were made between mid- 1973 and January 1982. Initial density of the aquatic biota was altered severely by heavy ash siltation, followed by acidic pH excursions and perhaps overall by elemental concentrations and bioaccumulation. Heavy ash siltation, followed by acidic Ph excursions (mean of 5.5, extreme of 3.5) after the addition of fly ash to the original settling basin system, had the most profound effect on biota. Dipterans (chironomids) and some odonates (Plathemis lydia and Libellula spp.) were resistant to heavy ash siltation, while mosquitofish, which showed no discernible responses to ash siltation, were absent at acidic pH, along with the few previously surviving invertebrate populations. Elemental concentrations of arsenic, cadmium, chromium, copper, selenium, and zinc did not appear to limit aquatic flora and fauna on a short-term, acute basis. Long, chronic elemental exposures may have been instrumental in retarding the recovery of all forms of aquatic life in the receiving system. Elemental concentrations (except for arsenic and selenium) in the receiving system were generally one to two orders of magnitude higher than the Water Quality Criteria set by the U.S. Environmental Protection Agency (1980) for protection of aquatic life for the minimum and 24-hour mean values. From collective elemental exposures in the receiving system, bioconcentration factors in macrophytes, invertebrates and fish were generally lower than those reported in the literature for laboratory, single elemental concentrations. By 1978, when the new settling basin systems were operating effectively, invertebrate populations were largely recovered, and mosquitofish populations recovered within one year afterward.     

“三线一单”纳入城市发展战略环评技术体系研究

将生态保护红线、环境质量底线、资源利用上线和环境准入负面清单（即"三线一单"）环境管理要求纳入战略环境评价（SEA）,是完善城市发展SEA的潜在有效手段,然而如何将两者进行有机结合尚缺乏实践经验.本文探讨了"三线一单"在城市发展SEA各主要评价环节的作用与评价内容,从重点任务和技术流程两方面建构了基于"三线一单"的城市发展SEA评价技术体系,并以鄂尔多斯绿色发展SEA为例进行检验.结果显示,对于鄂尔多斯这类空间尺度大、自然环境和产业发展异质性高的城市,该体系能够有效预防和解决战略实施过程中城镇无序扩张和产业结构失调造成的环境污染、生态功能退化和资源配置低效等问题,并推动完善城市分级分区差异化环境管控.     

浅谈危险性分析中应注意的问题

该文简要介绍了危险性分析的常用方法,阐明了进行危险性分析的前提,并运用详细的事例说明危险性分析时应注意辨识经验性违章及进行系统或设备隐蔽功能的分析等几个问题.     

浅论县(区)级环境监测站的现状和发展

本文分析了县（区）级环境监测站在我国加入WTO及政府机构改革后所存在的问题和面临的生存困难。指出当前该级别环境监测站存在的主要问题是缺乏管理，缺乏经费以及技术力量的逐步下降，在此基础上，文章提出了包括加强队伍建设，提高管理水平，进行标准化建设和实施QA／QC等诸多的合理化建设及良好的发展思路。     

企业停减产损失预测和评估模式

本文是文[1]的续篇。在文[1]中,作者对灾害经济损失评估的理论和方法做了初步的探讨．本文则着重对灾害间接经济损失中的企业停减产损失的预测和评估问题进行了探讨,建立了相应的预测和评估模式．所建立的模式既可用于灾前对企业停减产损失进行预测,也可用于灾后对其进行评估．     

烃类流体火灾伤害破坏作用定量分析

对烃类流体火灾的伤害破坏作用进行正确的定量分析是开展重大消防目标火灾风险评估工作的基础。针对烃类流体火灾伤害破坏作用定量分析中存在的问题,系统论述烃类流体火灾伤害破坏作用的定量分析方法,分析并讨论火球、池火、喷射火和蒸气云火灾等不同火灾形式的热辐射通量计算模型及其前提条件,对不同热辐射伤害破坏作用准则及伤害概率模型的适用条件和模型基础进行了论述。     

Assessing the Threat Status of Ecological Communities

Abstract: Conservationists are increasingly interested in determining the threat status of ecological communities as a key part of their planning efforts. Such assessments are difficult because of conceptual challenges and a lack of generally accepted criteria. We reviewed 12 protocols for assessing the threat status of communities and identified conceptual and operational issues associated with developing a rigorous, transparent, and universal set of criteria for assessing communities, analogous to the International Union for Conservation of Nature (IUCN) Red List standards for species. We examined how each protocol defines a community and its extinction and how each applies 3 overarching criteria: decline in geographic distribution, restricted geographic distribution, and changes to ecological function. The protocols vary widely in threshold values used to assess declines and distribution size and the time frames used to assess declines, leading to inconsistent assessments of threat status. Few of the protocols specify a scale for measuring distribution size, although assessment outcomes are highly sensitive to scale. Protocols that apply different thresholds for species versus communities tend to require greater declines and more restricted distributions for communities than species to be listed in equivalent threat categories. Eleven of the protocols include a reduction in ecological function as a criterion, but almost all assess it qualitatively rather than quantitatively. We argue that criteria should be explicit and repeatable in their concepts, parameters, and scale, applicable to a broad range of communities, and address synergies between types of threats. Such criteria should focus on distribution size, declines in distribution, and changes to key ecological functions, with the latter based on workable proxies for assessing the severity, scope, and immediacy of degradation. Threat categories should be delimited by thresholds that are assessed at standard scales and are logically consistent with the viability of component species and important ecological functions.     

不同气候带退耕还林对区域气温的影响差异分析

退耕还林改变陆表覆盖状况,导致碳收支和地表能量平衡变化,从而影响区域气温。论文通过定量估算耕地转为林地导致生态系统吸收大气CO₂和地表能量平衡的变化,分析21世纪初10 a中国不同气候区开展退耕还林对区域气候调节的影响差异。结果表明：1）仅考虑碳调节,各气候区退耕还林皆表现为241.6~470.2 Mg CO₂-eq hm^-2的碳蓄积过程,具有2.2~16.5 Mg CO₂-eq hm^-2的碳汇作用即致冷效应,特别是亚热带湿润区。2）仅考虑地表能量平衡,中温带干旱与半干旱区退耕还林引起的净辐射增加程度大于潜热通量的增加程度,因此地表对大气供热表现为增温效应;而亚热带湿润区退耕还林引起净辐射减少及潜热通量增加,青藏高原、中温带湿润区净辐射增加程度小于潜热通量的增加程度,因此地表对大气供热皆表现为致冷效应。3）同时考虑碳调节和地表能量收支,中国亚热带湿润区退耕还林的致冷效应是仅考虑碳调节致冷效应的1.25~1.45倍,而中温带干旱区退耕还林的致冷效应则为仅考虑碳调节效应的近一半。     

黄土坡耕地退耕还林后土壤性质变化研究

退耕还林是治理黄土高原水土流失的根本措施。论文以退耕历史较长的黄土丘陵沟壑区安塞县为例,选取不同类型植被恢复和不同恢复年限的退耕样区,探讨了退耕还林还草对土壤理化性质的影响。结果表明,坡耕地退耕后,遭侵蚀破坏的土体构型渐趋恢复,土壤容重、pH值减小,毛管孔隙度、饱和含水量等增大;土壤有机质增加了2.75倍,碳增加了27.29%,氮增加了46.79%;而且,土壤速效养分增加的速度大于土壤全量元素增加的速度。土壤质量恢复效益最大的是刺槐林地,其次是柠条灌木地,最小的是撂荒地。混交林土壤全氮含量最高,柠条最利于铵态氮、硝态氮和亚硝态氮的积累。不同类型植被,土壤速效养分的差异比土壤全量元素间的差异明显。随恢复时间的增加,土壤结构不断得到改善,土壤有机质、全碳、全氮以及主要离子含量呈明显增加趋势,土壤速效养分增加更明显。土壤有机质在植被恢复5年以上开始明显增加,土壤碳、氮和速效养分则在10年以后增加明显。