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991.
采用液膜萃取—酸析沉降—络合萃取组合工艺对有机磷阻燃剂生产废水进行预处理.最佳工艺条件为:液膜萃取时,液膜油相(表面活性剂与煤油的混合液)与内水相(H2SO4溶液)的体积比2∶1、乳化液膜与废水的体积比1∶8、废水pH 13.0,硫酸体积分数10%、煤油中表面活性剂质量浓度30 g/L、液膜萃取时间 15 min;酸析沉降时,废水pH l.0,酸析沉降时间30 min;络合萃取时,络合萃取剂(烷基叔胺N235与煤油的混合液)中烷基叔胺N235体积分数30%,络合萃取剂与废水的体积比1∶4,废水pH l.0,络合萃取时间30 min.在此最佳处理条件下,废水COD总去除率可达93%,吡啶去除率达99.9%以上,总磷去除率可达97%,BOD5/COD提高至0.32,有利于后续生化处理. 相似文献
992.
993.
K. -H. Oh H. Kim J. -B. Kim S. -E. Lee 《Journal of Loss Prevention in the Process Industries》2001,14(6):597-602
A study on the variation of the gas explosion characteristics caused by the built-in obstacles was conducted in enclosed/vented gas explosion vessels. It has been well known that the obstacles in pipes and long ducts would accelerate the flame propagation, and cause the transition from deflagration to detonation. In this study, the explosion characteristics and the flame behavior of vented explosions and constant-volume explosions were investigated. Experiments were carried out in a 270-liter and 36-liter hexahedron vessels filled with LPG–air mixture. The explosion characteristics of the gas mixture were determined by using a strain-responding pressure transducer. The flame behavior was recorded by using a high-speed video camera. The shape and the size of the obstacle, and the gas concentration, were adjusted in the experiments.
It can be seen from the experimental results that, instead of being accelerated, the flame propagation inside the explosion vessel is decelerated by the plate obstacles fixed at the bottom of the vessel. Also, the characteristics of the enclosed explosion are not so affected by the built-in obstacles as those of the vented explosion are. It is believed that the eddy-induced turbulence behind the obstacle decelerates the flame propagation. 相似文献
994.
系统安全预测的本质与组合预测 总被引:1,自引:0,他引:1
详细分析了系统安全预测的内在规律性、有效时间长度及有效性等方面的问题 ,提出了安全预测的本质就是建立系统安全可预测的思想。并针对目前的安全预测方法 ,提出了组合预测法 ,以提高安全预测的精度和准确性 相似文献
995.
ABSTRACT: Reservoir flood control is operated in real time so finding the optimal solution is unnecessary since it may not be practical. The key to reservoir flood control operation is quickly generating some feasible and effective alternatives and then selecting one among them. A fuzzy iteration methodology, which gives the objective weight and the relative membership degree of alternatives at the same time, is presented. Since the weight and relative membership degree are directly acquired from the recommended alternatives provided by decision makers, the results are more reasonable and realistic. Besides, the difficulty in giving weights is also avoided. With the aid of a robust and flexible decision support system, the effectiveness of decision making can be improved. 相似文献
996.
分别采用水解 -二段生物接触氧化以及二段生物接触氧化两种工艺 ,通过接种高效蔗糖降解菌对蔗糖厂洗布水的生化处理进行试验研究 ,结果表明 :填料采用煤渣较好 ;加适量的氮源和磷源能提高生化处理效果 ;两种工艺处理都能使废水达标排放 ,但从经济角度考虑认为水解 -二段接触氧化工艺较优。 相似文献
997.
998.
构建适应保护资源的政策法律新框架 总被引:1,自引:0,他引:1
本文分析了我国资源保护的特殊要求;认为我国进入了强化资源保护阶段,资源保护立法必须适应这个阶段;在此基础上,提出了我国资源保护政策法律新体制的基本构想和建议。 相似文献
999.
香港汀角红树植物、沉积物及双壳类动物重金属含量 总被引:14,自引:0,他引:14
汀角有香港面积最大的硬底质红树林,作者调查了该红树林区沉积物、红树植物以及双壳类动物体内重金属(Cu、Pb、Zn和Ni)的含量.总体看,沉积物中重金属含量与其他地点相比较低,红树植物根际沉积物中重金属含量高于光滩.红树植物组织内重金属含量较低,体内Pb、Zn的含量均低于根际沉积物,但对Cu、Ni有一定的富集,Cu可在根部和叶内富集,而Ni只在根部富集,并束缚于此.双壳类动物对4种重金属的吸收存在较大差异,Zn、Cu的富集明显高于Pb和Ni的富集程度.5种动物中又以岩蠔最高,体内的Zn、Cu分别达到3913, 378mg/g.从重金属含量看,作为食用动物有一定的风险. 相似文献
1000.
Y. P. Kim K. -C. Moon S. -G. Shim J. H. Lee J. Y. Kim K. Fung G. R. Carmichael C. H. Song C. H. Kang H. -K. Kim C. B. Lee 《Atmospheric environment (Oxford, England : 1994)》2000,34(29-30)
Organic carbon (OC) and elemental carbon (EC) in fine particles (PM2.5) at two background sites, Kosan and Kangwha in Korea were measured during intensive field studies between 1994 and 1999. Fine particles were collected on pre-fired quartz filters in a low-volume sampler and analyzed using the selective thermal oxidation method with MnO2 catalyst. The OC and EC concentrations at Kosan located at western tip of Cheju Island in southern Korea are lower than those at Kangwha located at western coastal area in mid-Korean peninsula. Still, the OC concentrations at Kosan are generally higher than those at other background areas in Japan and USA. The EC concentrations at Kosan are lower than or comparable to those at other background areas. The total carbon (TC, sum of OC and EC) to EC ratio values at both sites were higher than those at other background areas in Japan and USA. At Kosan, the OC and EC concentrations when air parcels were from southern China were higher than those when air parcels were coming from northern China. However, at Kangwha, the differences were statistically not clear since most air parcels were from northern China. Except when air parcels were from the North Pacific during summer, the OC and EC concentrations are well correlated indicating that both OC and EC share the same emission/transport characteristics. From the gaseous hydrocarbon data and the OC and EC relationship, it was found that during summer local biogenic emissions of OC might be significant at Kosan. 相似文献