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231.
本文总结了珠江三角洲地区部分乡镇企业发生工伤事故的现状、职业安全卫生方面存在的问题及由工伤事故所造成的经济损失的思考等。从研究的资料分析发现,近几年乡镇企业中工伤事故重伤率在18.00/10万以上,死亡率在70.00/10万以上,均高于国有企业。其中重伤率以村办企业(2.41‰)和中外合资企业(1.96‰)最高,死亡率以村办和国内独资企业最高(0.33‰,0.29‰)。  相似文献   
232.
通过对装有不同填料的2个厌氧移动床生物膜反应器(R1和R2)的有机负荷、COD去除率、沼气产量及其组成、出水挥发性有机酸(VFA)和出水pH值的对比,得出在填料充填率相同、进水COD和进水pH相似的情况下,填料比表面积是影响厌氧移动床生物膜反应器运行效果的主要因素.R1中填料的比表面积为528 m2/m3,R2中填料比表面积为211m2/m3.在整个运行阶段,填料比表面较大的R1反应器的运行结果较好.试验结束时,R1与R2的有机负荷比为1.61,而R1与R2填料上的污泥量之比为4.42.  相似文献   
233.
2001年11月启动的中国国家"十五"攻关重大专项"清洁能源行动"涉及17个试点示范城市,经过3年多的探索与实施,取得了明显成效.着重从污染物排放、空气质量、清洁能源消费、人均能耗和万元产值能耗等环境效益方面对清洁能源实施效果进行科学评价,为推广试点示范城市的先进经验和城市可持续发展提供依据.  相似文献   
234.
To investigate the cause of fine particulate matter (particles with an aerodynamic diameter less than 2.5 µm, PM2.5) pollution in the heating season in the North China Plain (specifically Beijing, Tianjin, and Langfang), water-soluble ions and carbonaceous components in PM2.5 were simultaneously measured by online instruments with 1-hr resolution, from November 15, 2016 to March 15, 2017. The results showed extreme severity of PM2.5 pollution on a regional scale. Secondary inorganic ions (SNA, i.e., NO3?+SO42+ NH4+) dominated the water-soluble ions, accounting for 30%-40% of PM2.5, while the total carbon (TC, i.e., OC + EC) contributed to 26.5%-30.1% of PM2.5 in the three cities. SNA were mainly responsible for the increasing PM2.5 pollution compared with organic matter (OM). NO3? was the most abundant species among water-soluble ions, but SO42- played a much more important role in driving the elevated PM2.5 concentrations. The relative humidity (RH) and its precursor SO2 were the key factors affecting the formation of sulfate. Homogeneous reactions dominated the formation of nitrate which was mainly limited by HNO3 in ammonia-rich conditions. Secondary formation and regional transport from the heavily polluted region promoted the growth of PM2.5 concentrations in the formation stage of PM2.5 pollution in Beijing and Langfang. Regional transport or local emissions, along with secondary formation, made great contributions to the PM2.5 pollution in the evolution stage of PM2.5 pollution in Beijing and Langfang. The favourable meteorological conditions and regional transport from a relatively clean region both favored the diffusion of pollutants in all three cities.  相似文献   
235.
Computer assisted movement tracking was used to characterize the motility of two marine microalgae, Isochrysis galbana and Tetraselmis chui, and to investigate the toxicity of Cu, Pb, and Cd on motile percentage, curvilinear velocity, average path velocity, straight line velocity, linearity, straightness, and wobble. Except for motile percentage, all other motility parameters di ered significantly between I. galbana and T. chui. Based on relative motile percentage data, the median e ective concentration (EC50) of Cu on the motility of I. galbana and T. chui was 31.4 and 1.3 mol/L, respectively, while for Pb it was 37.8 and 10.9 mol/L and for Cd it was 121.6 and 37.8 mol/L, respectively. Compared to I. galbana, T. chui was more sensitive to all tested metals. The toxic e ect of the heavy metals on motility exhibited the following decreasing order for both species: Cu > Pb > Cd. Our results indicate that I. galbana and T. chui motility is sensitive to heavy metals and can be used as an indicator for toxicology bioassays.  相似文献   
236.
生态修复技术在富营养化水库水质改善中的应用研究   总被引:2,自引:0,他引:2  
2006年初对广东省大镜山水库实施了生态修复工程,工程运行一年后,对该生态修复工程的效果进行了分析,结果表明:生态修复技术实施一年后,大镜山水库富营养化水平明显降低。与进水口(C区)相比,生态修复工程区(A、B区)透明度增加,氮、磷营养盐含量都有不同程度的降低。生态修复工程区TN、NH4-N与C区同期比最大降幅分别达19.6%、90.4%,TP、PO4-P同期比最大降幅分别达49.5%、67.5%,同时生态修复工程区内的叶绿素浓度也明显低于C区。  相似文献   
237.
柴瑜  李智 《环境科学与管理》2009,34(12):187-189
清洁生产审核是企业实现清洁生产最为有力和高效的工具之一,如今已广泛应用于各行各业。某卷烟厂结合自身清洁生产工作现状,采用清洁生产审核思路和程序,在审核过程中查找生产的薄弱环节,从生产的各个方面系统分析问题及其产生原因,并提出、实施了系列针对性清洁生产方案。该卷烟厂开展清洁生产审核的实践证明,清洁生产审核为企业走可持续发展道路奠定了坚实的基础,是企业实现环境效益和经济效益的双赢必由之路。  相似文献   
238.
为探究烧烤场景中人群多环芳烃(PAHs)的暴露特征与健康风险,使用美国环保署推荐的计算模型和基于生理的药代动力学模型(PBPK)模拟了我国人群的PAHs外暴露剂量和健康风险以及内暴露剂量变化情况。结果表明:1)普通居民和职业人群的日均苯并[a]芘等效摄入剂量为(50±3)ng·d~(-1)和(179±98)ng·d~(-1),其终生致癌风险为7.57×10~(-7)~1.28×10~(-5),均在可接受范围内;2)普通居民暴露后体内组织中PAHs内暴露标志物芘的最大浓度范围依次为肝(6.52~8.67 ng·L~(-1))肾(0.97~1.12 ng·L~(-1))静脉血(0.71~0.94 ng·L~(-1))皮肤(0.64~0.75 ng·L~(-1))脂肪(0.36~0.56 ng·L~(-1)),职业人群暴露后体内组织芘最大浓度为脂肪(2.97ng·L~(-1))皮肤(1.14 ng·L~(-1))≥肾(1.14 ng·L~(-1))肝(0.57 ng·L~(-1))静脉血(0.17 ng·L~(-1));3)膳食是普通人群的主导暴露途经,会导致肝组织浓度最大;呼吸和皮肤接触是职业人群的主导暴露途经,会导致脂肪组织浓度最大;4)暴露标志物芘的组织总富集量关系为职业人群(48 ng·d~(-1))大于普通人群(6~11 ng·d~(-1))。  相似文献   
239.
To explore human biomonitor of persistent organic pollutants (POP) for public health risk assessment, extractable organohalogens (EOX), extractable persistent organohalogens (EPOX) and some selected organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) in children hair from urban and rural regions of Beijing, China, were measured by instrumental neutron activation analysis (INAA) and gas chromatography-electron capture detector (GC-ECD). The results indicated that about 96% of the total halogens existed as water-soluble polar compounds; about 25 to 50% of EOX were sulfuric acid-resistant EPOX; organochlorines were the major fraction of the organohalogens; and 88 to 99.6% of extractable persistent organochlorines (EPOCl) cannot be attributed to the selected OCP and PCB. HCH, DDT and 2-5CB were the major contributors to hair OCP and PCB. Further, gamma-HCH, p,p'-DDE, p,p'-DDT and PCB-52 were the predominant individuals of HCH, DDT and 2-5CB, respectively. The concentration distributions of EPOCl, HCH, DDT and PCB in children hair were generally in the order of urban>rural and girls>boys, except for PCB congeners with random distributions between genders. Pearson positive correlations between hair lipid and the detected parameters of hair gamma-HCH (p<0.01), DDT (p<0.01), EOCl (p<0.05), as well as EPOCl (p<0.05) were observed. Also, the ratios of hair alpha/gamma and p,p'-DDE/p,p'-DDT suggested that fresh input of HCH and DDT might exist in Beijing area. Hair can reflect body's integral exposure to POP from endogenous and exogenous sources, which, thus, can be used as a potential biomonitor in assessing POP exposure for public health purposes.  相似文献   
240.
为克服烟气脱硫石膏改良盐碱地存在的土壤盐分升高、营养物质降低等不足,通过对不同重量配比的园林废弃物堆肥与适量烟气脱硫石膏混合施用,且开展了其对上海南汇滨海盐渍土的改良效应研究。结果表明:2种改良剂混合施用能显著降低滨海盐渍土pH和全盐含量,增加土壤营养物质含量和植物生物量,并提高植物对营养物质的吸收能力;与对照相比,当烟气脱硫石膏施用量为25 g·kg~(-1)时,土壤pH降低了10.9%,EC升高了8.4%,有效磷、有效氮和速效钾含量分别降低了30.1%、 40.5%和36.1%,黑麦草发芽率下降了8.0%,植株内全氮、全钾含量均有所升高,但全磷含量减少了25.4%;混合施加不同重量配比的园林废弃物堆肥后,土壤pH降幅为6.8%~13.8%, EC降幅为4.2%~11.6%;土壤有效磷、有效氮和速效钾含量增幅分别为96.0%~182.7%、40.0%~186.7%和71.7%~157.5%;黑麦草发芽率和生物量逐渐增加,在园林废弃物堆肥施用量为40%时,与对照处理相比,此时植物发芽率达到90.0%,总湿重、地上干重、株高和根长等分别增加了154.1%、100.0%、89.2%和103.6%,植株体内氮和钾含量分别增加了139.9%和40.8%,磷的含量则接近对照处理。通过分析可知,烟气脱硫石膏和园林废弃物混合施用可较好地改良滨海盐渍土壤,并为城市固废的适合处置方式和综合利用途径提供了参考。  相似文献   
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