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41.
稠油污水处理系统改造与絮凝剂筛选试验研究 总被引:2,自引:1,他引:2
河南油田井楼稠油联合站含油污水中的污油和悬浮物含量较高,超过150mg/L。为此,对该处理系统进行了改造,并对絮凝剂的筛选进行了试验。结果表明:无机絮凝剂与有机絮凝剂联合作用,可对污水中所含有的污油和有机物杂质的悬浮物产生很好的絮凝沉降效果。加药浓度、加药顺序及沉降时间均对絮凝沉降效果有一定的影响。改造后的污水处理系统实现了污水达标回注,降低了无效回注费用。同时还回收了污油,降低了药剂成本,产生了十分明显的经济效益,每年节约成本约500万元。 相似文献
42.
利用信息不对称理论对市场交易中的道德风险和逆向选择进行了解释。对国家同商业银行及中介机构的信息不对称,商业银行同工商企业的信息不对称,国家金融机构信息获取方面存在的困难的原因进行了分析。研究了由于信息不对称利率、汇率、管理及决策在金融行业的风险,以及操作过程中,贷款对象选择,对中小企业贷款的风险。只要充分重视金融风险,采取得当的防范对策,风险是可以防范的。 相似文献
43.
中国石油大连石化公司的生产废水不仅具有炼化废水的复杂性,而且其中含有大量的氯离子,给絮凝药剂的筛选带来一定的困难。通过对715、728两种絮凝药剂的现场应用实验,找出了不同水质情况下的最佳投药量。实验结果表明,当污水中含油量大于100mg/L时,715药剂加入量控制在150~180mg/L,728的加入量为4mg/L,此时油、SS、COD、浊度的去除率分别为92%、41%、41%和82%。当污水含油量在30mg/L以下时,715药剂加入量为90~120mg/L,728加入量为2.7~3.3mg/L,此时油、SS、COD、浊度的去除率分别为74%、71%、38%和89%。经实验筛选出的这两种药剂可以利用现有的加药系统设备加入污水,加药处理后能提高出水的水质。 相似文献
44.
Sustainable development goals are achievable through the installation of Material Recovery Facilities (MRFs) in certain solid waste management systems, especially those in rapidly expanding multi-district urban areas. MRFs are a cost-effective alternative when curbside recycling does not demonstrate long-term success. Previous capacity planning uses mixed integer programming optimization for the urban center of the city of San Antonio, Texas to establish that a publicly owned material recovery facility is preferable to a privatized facility. As a companion study, this analysis demonstrates that a MRF alleviates economic, political, and social pressures facing solid waste management under uncertainty. It explores the impact of uncertainty in decision alternatives in an urban environmental system. From this unique angle, waste generation, incidence of recyclables in the waste stream, routing distances, recycling participation, and other planning components are taken as intervals to expand upon previous deterministic integer-programming models. The information incorporated into the optimization objectives includes economic impacts for recycling income and cost components in waste management. The constraint set consists of mass balance, capacity limitation, recycling limitation, scale economy, conditionality, and relevant screening restrictions. Due to the fragmented data set, a grey integer programming modeling approach quantifies the consequences of inexact information as it propagates through the final solutions in the optimization process. The grey algorithm screens optimal shipping patterns and an ideal MRF location and capacity. Two case settings compare MRF selection policies where optimal solutions exemplify the value of grey programming in the context of integrated solid waste management. 相似文献
45.
Payal Shah Mindy L. Mallory Amy W. Ando Glenn R. Guntenspergen 《Conservation biology》2017,31(2):278-289
Climate‐change induced uncertainties in future spatial patterns of conservation‐related outcomes make it difficult to implement standard conservation‐planning paradigms. A recent study translates Markowitz's risk‐diversification strategy from finance to conservation settings, enabling conservation agents to use this diversification strategy for allocating conservation and restoration investments across space to minimize the risk associated with such uncertainty. However, this method is information intensive and requires a large number of forecasts of ecological outcomes associated with possible climate‐change scenarios for carrying out fine‐resolution conservation planning. We developed a technique for iterative, spatial portfolio analysis that can be used to allocate scarce conservation resources across a desired level of subregions in a planning landscape in the absence of a sufficient number of ecological forecasts. We applied our technique to the Prairie Pothole Region in central North America. A lack of sufficient future climate information prevented attainment of the most efficient risk‐return conservation outcomes in the Prairie Pothole Region. The difference in expected conservation returns between conservation planning with limited climate‐change information and full climate‐change information was as large as 30% for the Prairie Pothole Region even when the most efficient iterative approach was used. However, our iterative approach allowed finer resolution portfolio allocation with limited climate‐change forecasts such that the best possible risk‐return combinations were obtained. With our most efficient iterative approach, the expected loss in conservation outcomes owing to limited climate‐change information could be reduced by 17% relative to other iterative approaches. 相似文献
46.
双季稻田CH4和N2 O排放特征及品种筛选研究 总被引:1,自引:1,他引:0
通过大田小区实验,采用静止箱-气相色谱法对早晚两季水稻品种CH4与N2O排放通量进行了观测.结果表明,早稻CH4排放季节变化呈单峰模式,N2O排放呈双峰模式;晚稻CH4与N2O排放季节变化均呈单峰模式.CH4、N2O季节平均排放通量品种间均存在显著差异(P<0.05).早稻品种CH4、N2O季节平均排放通量极差分别为0.58 mg.(m2.h)-1、5.89μg.(m2.h)-1,晚稻为4.06 mg.(m2.h)-1、5.70μg.(m2.h)-1;早稻品种温室气体排放的增温潜势、单位产量增温潜势极差分别为2.92 kg.hm-2、0.097 kg.kg-1,晚稻分别为2 256 kg.hm-2、0.28 kg.kg-1.增温潜势、单位产量增温潜势比较,常规稻>超级杂交稻>杂交稻.早稻无水稻种植区CH4、N2O季节排放通量分别是水稻种植区的27.1%~31.8%、33.6%~88.3%;晚稻分别是23.8%~28.8%、38.6%~45.3%.早稻适宜种植品种为陆两优819、金优402、湘早籼24号,晚稻品种为岳优9113、湘晚籼12号. 相似文献
47.
48.
Soil and preen waxes influence the expression of carotenoid-based plumage coloration 总被引:1,自引:1,他引:0
The signaling function of carotenoid-based plumage is mainly determined by the concentration of pigments in feathers. For
this reason, most studies of the proximate control of coloration focus on processes during and preceding moult. In great tits
Parus major, past research demonstrates that carotenoid-based plumage coloration honestly indicates male quality and, thus, may be a
sexually selected signal. In this study, we investigate how dirt and preen oil influence the coloration of carotenoid-based
feathers in the great tit. We collected six feathers from each individual bird; three feathers served as controls while the
remaining three feathers were washed with a chloroform/methanol mixture to remove soil and preen waxes. We assessed plumage
coloration using digital photography. This cleaning procedure slightly enhanced ornamentation; the experimentally cleaned
feathers expressed hues shifted towards shorter wavelengths and expressed brighter overall coloration than control feathers.
This is the first experimental study conducted on wild birds demonstrating that, in addition to pigment concentration, the
presence of preen waxes and soils on feathers may contribute to variation in coloration. 相似文献
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