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991.
针对废PP(聚丙烯)的抗冲击强度降幅明显的问题,分别采用POE(乙烯-辛烯共聚物)和SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)作为增韧剂,对废PP共混改性效果进行了研究. 结果表明:POE和SBS均可有效改善废PP的韧性,提高冲击强度;当弹性体用量为15%(以w计,下同)左右时,其共混体系的冲击变化过程由脆性断裂逐渐向韧性断裂转变;添加16.7%的弹性体时,POE和SBS共混体系的冲击强度可分别达到新PP的2.33和1.90倍,但POE对共混体系的冲击性能改善效果更佳. POE较SBS在废PP基体中分布更为均匀,弹性体用量为16.7%时,PP/POE体系熔体流动速率为17.4g/10min,大于PP/SBS体系(6.21g/10min),即PP/POE体系具有加工优势. 但是添加弹性体后,废PP共混体系的拉伸强度、弯曲强度等指标有所下降,需进一步提高.   相似文献   
992.
Incentive approaches are believed to be indispensable for effective conservation and successful management in protected areas. However, the actual effectiveness of these approaches is still debatable. We carried out a case study in Wolong Biosphere Reserve (WBR), the largest reserve for the giant panda (Ailuropoda melanoleuca), to evaluate the effectiveness of incentives. We obtained data from government documents and statistics, interviews and surveys on the employment status of public sector and industries. Results indicated that government-paid community-based conservation projects provided the most widespread and direct economic incentives. The conservation sector and several industries including hotels, hydropower and tourism have directly raised the employment level of local communities. The hotel industry, driven by the development of tourism, has been the most effective means of increasing local employment. However, the problem of immigrants attracted by the improved economic situation in WBR should be considered in the management plans. Suggestions for WBR management include development of quality ecotourism, vocational education for local young adults and new policies encouraging employment of local labour, both in the reserve and outside. Lessons learned from this research are constructive for the management of other protected areas.  相似文献   
993.
白渝  亓玲 《防灾博览》2004,(4):36-36
如今的都市人在紧张的工作之余,首选健身已是一种时尚。然而,由于都市地皮紧张,各类健身房基本设在了楼房里,且多数安营扎寨于地下室中。这样,问题也就出现了。  相似文献   
994.
层次分析法在生活垃圾处置方案优选中的应用   总被引:4,自引:0,他引:4  
聂曦  张琦  姚群 《工业安全与环保》2004,30(12):18-20,17
对于如城市生活垃圾处置技术方案优选这类多目标、多方案决策问题,特别是在决策缺乏充分的信息支持前提时,AHP分析法的若干特点,显示其作为一种系统工程的理论工具具有一定的客观性、准确性和有效性,是一种简易而且可行的理论方法和手段。通过以某经济开发区生活垃圾处置方案的优选为例进行了探讨。  相似文献   
995.
董书香  李永明  亓玲 《防灾博览》2005,(6):28-28,30
近几年,日本许多机关都在公开地震观测数据,尤其是强震数据。除通过K—NET公开数据的防灾科学技术研究所和日本气象协会外,震灾预防悱会、建筑学会、关西地震观测研究协会以及10个电力共同研究等民间机构电都致力于此项研究。强震观测数据内容以自由地丛表面的为多。从抗震上程学和地震防灾角度来看,所哺的垂直台阵地震观测数据在增加,反映出人们对地基上地震波增幅的重要性队激的提高.但有荧建筑物的观测数据.除日本建筑学会根据兵库县南部地震进行收集、  相似文献   
996.
新疆孔雀河表层沉积物中有机氯农药的分布及风险评价   总被引:2,自引:0,他引:2  
分析了新疆孔雀河9个表层沉积物样品中22种有机氯农药(OCPs)含量,其主要OCPs含量的顺序为:六六六>异狄氏剂醛>滴滴涕>艾氏剂>硫丹Ⅱ>异狄氏剂>氯丹.研究表明,近期有γ-HCH输入到孔雀河,其最可能的来源是博斯腾湖的补给或孔雀河附近的农业回流水.滴滴涕的组成特征分析表明,DDTs主要源于施用的农药在好氧环境土壤中的分解,产生DDE等主要产物.风险评价表明,污染物的风险较低,所有被评估的OCPs的风险值均小于风险评价高限(ERM).  相似文献   
997.
In lizards, males are predicted to sprint faster and run for longer than females by virtue of higher testosterone levels and differences in morphology. Consequently, escape behaviour is also predicted to be associated with sex and locomotor performance, yet these links have rarely been explored. Here, we tested whether escape behaviour is associated with locomotor performance in the toad-headed agama, Phrynocephalus vlangalii, and whether it is sex-dependent. This species is also characterized by elaborate tail displays, which we examined as a potential pursuit-deterrent signal. Tail waves were performed by a very small proportion (2/58, 3 %) of individuals during predatory trials, suggesting that tail signalling functions exclusively in a social context. To understand the relationships between sex, escape behaviour and performance, we first measured escape behaviour (flight initiation distance, flight distance—measured differently compared to previous studies of lizard escape behaviour, and refuge use) in the field before measuring maximal sprint speed and endurance on the same individuals in the laboratory. Flight initiation distance did not differ between the sexes and was unrelated to performance capacity (maximal endurance and sprint speed) but was positively related to body size with larger individuals fleeing earlier. Males fled farther than females, but flight distance was also unrelated to either endurance or sprint speed. Interestingly, faster females were less likely to enter a refuge than slower females, whereas sprint speed and the probability of taking refuge were unrelated for males. Our results suggest that when males and females are not obviously sexually dimorphic, they are more likely to overlap in escape tactics.  相似文献   
998.
通过数据驱动模型理论和变密度各项异性湍浮力射流模型的有机结合,提出了射流比和射流喷角多参数优化耦合反演的新方法:通过射流模型计算射流比和射流喷角多参数匹配设计的数值工况,构建计算水域内部观测点污染物浓度解集;以数据驱动模型理论建立状态变量(污染物稀释度)同控制变量(模型多参数)之间的非线性关系;将拟获得的稀释度带入关系中,进行模型多参数的组合优化反演研究,结果表明基于数据驱动模型理论的多参数反演方法可以获得最优的射流参数,有利于射流水体与环境水体间的掺混。  相似文献   
999.
As the second largest freshwater lake in China, Taihu Lake provides water supply to approximately 32 million inhabitants around the lake. However, dramatically increased pollution has threatened the safety of drinking water supply in recent years. In the present study, we investigated the contaminations of nutrients and heavy metals in the sediments of an intake and inflow canals in Gonghu Bay, Taihu Lake. Moreover, we also examined the impact of human activities on spatial distribution characteristics of contaminations. Our results showed that the intake presented relatively lower concentrations of phosphorus and nitrogen compared with inflow canals. However, the concentrations of Cr, Ni, Cu, Zn and Pb in the sediments of the intake exceeded the lowest effect level (LEL) values, indicating a potential risk to drinking water resource. In addition, the concentrations of Ni in the sediments of Tianji Canal and Jinshu Canal exceeded the severe effect level (SEL) value. More importantly, the concentrations of Cu in the sediments of Tianji Canal exceeded three times of the SEL value. Multivariate statistical analysis confirmed that the domestic sewage primarily contributed to the nutrient accumulation, and the leakage of electronic trash dominated the enrichment of metals in the sediments. Taken together, more effort should be made to ensure the security of water resources in Taihu Lake, especially for the treatment of domestic sewage and industrial wastewater.  相似文献   
1000.
以产业物质代谢模型和生态效率理论为基础,采用权重分析法对我国2009年38个重点行业的资源环境效率和经济效率进行了评估。研究表明:机械设备制造相关行业可作为我国产业结构调整优先发展的领域,化工、钢铁等重工业行业是我国循环经济的重点。  相似文献   
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