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431.
432.
An optimized nonlinear grey Bernoulli model was proposed by using a particle swarm optimization algorithm to solve the parameter optimization problem. In addition, each item in the first-order accumulated generating sequence was set in turn as an initial condition to determine which alternative would yield the highest forecasting accuracy. To test the forecasting performance, the optimized models with different initial conditions were then used to simulate dissolved oxygen concentrations in the Guanting reservoir inlet and outlet (China). The empirical results show that the optimized model can remarkably improve forecasting accuracy, and the particle swarm optimization technique is a good tool to solve parameter optimization problems. What's more, the optimized model with an initial condition that performs well in in-sample simulation may not do as well as in out-of-sample forecasting. 相似文献
433.
An optimized nonlinear grey Bernoulli model was proposed by using a particle swarm optimization algorithm to solve the parameter optimization problem. In addition, each item in the first-order accumulated generating sequence was set in turn as an initial condition to determine which alternative would yield the highest forecasting accuracy. To test the forecasting performance, the optimized models with different initial conditions were then used to simulate dissolved oxygen concentrations in the Guanting reservoir inlet and outlet (China). The empirical results show that the optimized model can remarkably improve forecasting accuracy, and the particle swarm optimization technique is a good tool to solve parameter optimization problems. What's more, the optimized model with an initial condition that performs well in in-sample simulation may not do as well as in out-of-sample forecasting. 相似文献
434.
绿色大学是在日益严重的环境问题背景下生态文明和社会可持续发展理念融合于校园的必然趋势.作为技术传承和创新的主体,积极探索和深化高校能源改革具有非常重要的意义.本文以中国石油大学的面板数据作为数据研究基础,结合气候能源因素,提出基于综合节能模型的绿色大学构想,采用簇聚类和遗传优化进行能源整合,动态评估后进行系统参数加权优化,从而达到能源优化使用的目标.实践表明,该模型有效提升能源效率和改善环境,具有重要的应用意义. 相似文献
435.
随着城市建设步伐的加快,人口数量增多,城市基础设施的完善,建成区的扩大和功能区类型的改变,"十二五"城市声环境监测点位的调整、优化是必然趋势.本文结合浙江省"十二五"城市声环境监测点位优化布设的实际工作情况,对城市声环境监测点位优化布点原则、方法等进行了阐述.以"十一五"声环境监测点位布设现状为基础,结合功能区环境噪声的普查数据,对优化选点监测数据进行分析,选出具有空间分布适当,可以保证设备安全,方便操作,并且数据具有较好的代表性的测点.优化调整后,城市区域环境噪声有效网格覆盖面积增加了80.8%,道路交通噪声监测总路长增加了67.0%,功能区定点噪声测点数量增加了129.2%,优化调整后的监测点位更能客观反映城市区域环境噪声实际情况. 相似文献
436.
437.
Characterization and prediction of highway runoff constituent event mean concentration 总被引:3,自引:0,他引:3
Highway stormwater runoff quality data were collected from throughout California during 2000-2003. Samples were analyzed for conventional pollutants (pH, conductivity, hardness, and temperature); aggregates (TSS, TDS, TOC, DOC); total and dissolved metals (As, Cd, Cr, Cu, Ni, Pb, and Zn); and nutrients (NO(3)-N, TKN, total P, and ortho-P). Storm event and site characteristics for each sampling site were recorded. A statistical summary for chemical characteristics of highway runoff is provided based on statewide urban and non-urban highways. Constituent event mean concentrations (EMCs) were generally higher in urban highways than in non-urban highways. The chemical characteristics of highway runoff in California were compared with national highway runoff chemical characterization data. The results obtained in California were generally similar to those found in other states. The median EMC for Pb measured in studies conducted in previous decades was much higher than the current median Pb EMC in California. The lower Pb EMC in California compared to previous highway runoff monitoring is believed to be due to the elimination of leaded gasoline. An attempt was also made to identify surrogate constituents within a general family of water quality categories using Spearman correlations and selected pairs with Spearman coefficients greater than 0.8. The strongest correlations were observed among parameters associated with dissolved minerals (EC, TDS, and chloride); organic carbon (TOC and DOC); petroleum hydrocarbons (TPH and O & G); and particulate matter (TSS and turbidity). Within the metals category, total iron concentration was highly correlated with most total metal concentrations. The correlations between total and dissolved concentrations were all less than 0.8, even between total and dissolved concentrations of the same metals. Multiple linear regression (MLR) analyses were performed to evaluate the impact of various site and storm event variables on highway runoff constituent EMCs. Parameters found to have significant impacts on highway runoff constituent EMCs include: total event rainfall (TER); cumulative seasonal rainfall (CSR); antecedent dry period (ADP); contributing drainage area (DA); and annual average daily traffic (AADT). Surrounding land use and geographic regions were also determined to have a significant impact on runoff quality. The MLR model was also used to predict constituent EMCs. Model performance determined by comparing predicted and measured values showed good agreement for most constituents. 相似文献
438.
多目标优化方法在区域水资源优化配置中的应用——以唐山市为例 总被引:3,自引:0,他引:3
水资源供需矛盾日益加剧,如何优化配置区域内有限的水资源已成为水资源规划与管理研究中的热点.本文在考虑不同水质和水源的基础上,研究了决策变量的约束条件,综合考虑不同用水户的用水效益,采用工业、生活、环境和农业多目标优化的方法,按照决策者的不同意愿,给出不同的配置方案,即一系列非劣解集.通过调用Matlab优化工具箱中的函数对其进行求解,给出了5种不同的水资源优化配置方案,能够合理配置唐山市区内有限的水资源,使得该区域内环境、社会与经济协调发展. 相似文献
439.
通过正交实验设计,对水体中MC-LR前处理过程中SPE柱的选择、水样pH值、洗脱液有机相浓度、酸度和体积等关键因素进行综合分析,得出最优前处理方案。通过精密度和加标回收实验,得出该方法精密度为4.81%,加标回收率为98.96%。 相似文献
440.