首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   592篇
  免费   36篇
  国内免费   232篇
安全科学   48篇
废物处理   41篇
环保管理   58篇
综合类   316篇
基础理论   93篇
污染及防治   221篇
评价与监测   32篇
社会与环境   18篇
灾害及防治   33篇
  2023年   7篇
  2022年   25篇
  2021年   25篇
  2020年   25篇
  2019年   18篇
  2018年   21篇
  2017年   22篇
  2016年   26篇
  2015年   33篇
  2014年   49篇
  2013年   69篇
  2012年   53篇
  2011年   46篇
  2010年   43篇
  2009年   51篇
  2008年   36篇
  2007年   40篇
  2006年   37篇
  2005年   31篇
  2004年   15篇
  2003年   18篇
  2002年   19篇
  2001年   25篇
  2000年   16篇
  1999年   18篇
  1998年   10篇
  1997年   16篇
  1996年   18篇
  1995年   10篇
  1994年   8篇
  1993年   9篇
  1992年   4篇
  1991年   2篇
  1990年   11篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
排序方式: 共有860条查询结果,搜索用时 15 毫秒
21.
Based on the data of 30 Chinese provinces for the period from 2004 to 2015, this paper expounds the carbon emissions effect of two-way foreign direct investment (FDI) from the perspective of scale effect and factor market distortions. This study uses Kaya identity to decompose carbon emission and construct simultaneous equations model to empirically examine the factor market distortion and the carbon emission scale effect of two-way FDI. The results show that the inward foreign direct investment (IFDI) increase regional carbon emission through scale effect and also exacerbates factor market distortion in China, whereas the outward FDI trends reduce carbon emission and reduces factor market distortions in China. The study also shows that human capital, research and development (R&D), trade openness, and capital accumulation are important determinants of two-way FDI. Therefore, the study proposes that IFDI policies should focus on acquiring green technologies. In addition, the domestic enterprises should be encouraged to participate in global business.  相似文献   
22.
Dioxin-like polychlorinated biphenyls (DLPCBs) are ubiquitous persistent pollutants that cause adverse effects in many environmental organisms. DLPCBs in marine sediments can be absorbed by benthic organisms, bioaccumulate, and biomagnify through the food chain and threaten animal and human health. There are no reports of DLPCBs concentrations in the Zhanjiang Gulf seabed. This study was designed to investigate the concentration of DLPCBs in the Zhanjiang coastal sediment and histopathological changes in zebrafish (Diano rerio) embryos exposed to environmentally relevant concentrations of DLPCBs. Of the five sites selected, two sites TS and JSW contained DLPCBs at concentrations of 0.08 and 22.54 ng/g dry sediment, respectively. Two groups of zebrafish embryos were used. One group was exposed to 3.75, 7.5, 15, 30, and 60 mg/ml of DLPCBs extracted from the sediments sampled from the TS site and the second group to 4.375, 8.75, 17.5, 35, and 70 mg/ml of DLPCBs from JSW site from 0.75 h post-fertilization (hpf) to 96 hpf. The zebrafish exposed to 60 and 70 mg/ml of DLPCBs at 96 hpf displayed gross histopathological changes with cardiac lesions including pericardial edema being the most deleterious. Other changes observed were hydropic degeneration of gill filaments and hepatocytes, loss of intestinal folds, and uninflated swim bladder. It appears that only a few sites of the Zhanjiang gulf are contaminated with DLPCBs. This is the first report of histopathological changes in the gills, hepatocytes, intestines, heart, and the swim bladder in zebrafish embryos exposed to DLPCBs from a coastal sediment. Further studies with sampling at different stages of development are required to identify which organ/tissue is most sensitive to DLPCBs.  相似文献   
23.
龚鹏飞 《灾害学》2014,(1):120-124
突发事件发生后,为了保障承担抢险救灾任务的一般救灾车辆在尽可能短的时间内赶赴现场,应该确立其优先通行权。在分析优先通行权概念内涵、比较应急车辆与一般救灾车辆承担的运输任务的基础上,从法律定位上明确其应享有优先通行权,并建议在相关的法律规范修订中明确承担救灾任务的一般救灾车辆应享有与应急车辆相同的优先通行权。在具体的交通组织上,提出采用警车带队编队通行的方式来实现一般救灾车辆的优先通行权。在安全保障方面,应该在相关的应急预案阶段制定一般救灾车辆操作指南,储备性能优良的一般救灾车辆,挑选受过专门训练,具有良好的业务素质、交通安全素养及身体素质的车辆驾驶人。  相似文献   
24.
Environmental Science and Pollution Research - Microbial fuel cell (MFC) is a sustainable technology to treat cattle manure slurry (CMS) for converting chemical energy to bioelectricity. In this...  相似文献   
25.
• UV/O3 process had higher TAIC mineralization rate than O3 process. • Four possible degradation pathways were proposed during TAIC degradation. • pH impacted oxidation processes with pH of 9 achieving maximum efficiency. • CO32– negatively impacted TAIC degradation while HCO3 not. • Cl can be radicals scavenger only at high concentration (over 500 mg/L Cl). Triallyl isocyanurate (TAIC, C12H15N3O3) has featured in wastewater treatment as a refractory organic compound due to the significant production capability and negative environmental impact. TAIC degradation was enhanced when an ozone(O3)/ultraviolet(UV) process was applied compared with the application of an independent O3 process. Although 99% of TAIC could be degraded in 5 min during both processes, the O3/UV process had a 70%mineralization rate that was much higher than that of the independent O3 process (9%) in 30 min. Four possible degradation pathways were proposed based on the organic compounds of intermediate products identified during TAIC degradation through the application of independent O3 and O3/UV processes. pH impacted both the direct and indirect oxidation processes. Acidic and alkaline conditions preferred direct and indirect reactions respectively, with a pH of 9 achieving maximum Total Organic Carbon (TOC) removal. Both CO32– and HCO3 decreased TOC removal, however only CO32– negatively impacted TAIC degradation. Effects of Cl as a radical scavenger became more marked only at high concentrations (over 500 mg/L Cl). Particulate and suspended matter could hinder the transmission of ultraviolet light and reduce the production of HO· accordingly.  相似文献   
26.
Environmental Science and Pollution Research - The Yellow River Basin is an energy-rich area. The low-carbon development of the Yellow River Basin is one of the ways to achieve ecological...  相似文献   
27.
垃圾填埋场微生物气溶胶粒径分布研究   总被引:4,自引:0,他引:4  
为了了解垃圾填埋场微生物气溶胶粒径分布规律,在北京市某垃圾卫生填埋场填埋区、渗滤液处理区、生活区分别选定监测点,利用安德森六级微生物采样器,对填埋场空气微生物进行了系统的定点取样、测定和分析。研究结果表明,空气细菌粒径分布均为第Ⅰ级(>8.2 μm)最高,填埋区空气细菌粒径呈偏态分布,渗滤液处理区、生活区分别在第Ⅳ级和第Ⅲ级出现第2个峰值。携带细菌的可吸入微粒在渗滤液处理区比例最大。空气真菌与放线菌均在第Ⅳ级分布最高,携带真菌和放线菌的可吸入粒子的比例显著大于细菌(P<0.05)。填埋区不同作业时段空气微生物粒径在各级分布比例基本一致。填埋区细菌气溶胶中值直径为5.7 μm,渗滤液处理区为3.7 μm,生活区为5.3 μm,显著大于真菌气溶胶和放线菌气溶胶的中值直径(P<0.05)。  相似文献   
28.
Using the monthly hydrogeochemical data of ChangLe River system from 2004 to 2008, total nitrogen (TN) export load (S(n)) from nonpoint sources (NPS) to stream and in-stream attenuation load (A(L)) was estimated by the inverse and forward format of an existing in-stream nutrient transport equation, respectively. Estimated S(n) contributed 96 ± 2% of TN entering the river system, while A(L) reduced the input TN by 23 ± 14% in average. In-stream TN attenuation efficiency in high flow periods (10 ± 5% in average for the entire river system) was much lower than that in low flow periods (39 ± 17%). TN attenuation efficiency in tributaries (28 ± 16% in average) was much higher than that in mainstream (11 ± 8%). Hydrological conditions are important in determining the spatio-temporal distributions of NPS TN export, stream attenuation and discharge. Increasing the water residence time might be a practical method for mitigating stream TN.  相似文献   
29.

Purpose  

Nonpoint sources (NPS) pollution has been an important cause for water quality impairment worldwide. To take the temporal variations of both NPS pollution and in-stream attenuation into consideration, an inverse modeling approach and the load duration curve (LDC) method were combined for variable nutrient total maximum daily load (TMDL) development.  相似文献   
30.
Environmental Science and Pollution Research - Ionizing radiation (IR) is a form of high energy. It poses a serious threat to organisms, but radiotherapy is a key therapeutic strategy for various...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号