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251.
Prediction of sludge bulking is a matter of growing importance around the world. Sludge volume index (SVI) should be monitored to predict sludge bulking for a wastewater treatment plant. This study was an effort to develop hybrid artificial neural network-genetic algorithm models (MLPANN-GA and RBFANN-GA) to accurately predict SVI. Operating parameters, including MLVSS, pH, DO, temperature, TSS, COD and total nitrogen were the inputs of neural networks. Genetic algorithm was utilized in order to optimize weights and thresholds of the MLPANN and RFBANN models. Training procedures for SVI estimation were successful for both the MLPANN-GA and RBFANN-GA models. The training and validation models showed an almost perfect match between experimental and predicted values of SVI. The results indicated that with low experimental values of input data to train ANNs, the MLPANN-GA compared with the RBFANN-GA is more accurate due to higher coefficient of determination (R2) and lower root mean squared error (RMSE) values. The values of RMSE and R2 for the optimal models approached 0 and 1, respectively. The mean average error for the ANN models did not exceed 3% of the input values of the measured SVI. The GA increased the accuracy of all the MLPANN and RBFANN models. 相似文献
252.
Identification of electricity energy consumption on individual household appliances used in a smart house is the first important step for making the use and conservation of electricity energy more efficient. In the past, Non-Intrusive Load Monitoring (NILM) techniques, which are part of smart grid techniques realized to improve electricity energy usage efficiency, have been developed to identify individual appliances with avoiding installing many smart meters for appliances in a field. In this paper, a new NILM technique that integrates an efficient Genetic Programming (GP)-based feature optimizer with pattern recognition techniques is proposed to identify which appliance is being turned on or off. The proposed GP-based feature optimizer with Fisher criterion is used to generate a more efficient feature than original potential transient features extracted from captured transient response of household appliances through analysis of NILM. The new feature generated by GP is used by pattern recognition techniques as load identifiers for load identification. The load identifiers used and compared in this paper include k-Nearest-Neighbor Rule, Back-Propagation Artificial Neural Network, and Learning Vector Quantization. Experiments are conducted under different single-load and multiple-load operation circumstances at different actual experimental environments with small disturbances. As shown from the experimental results, the proposed is confirmed to be feasible and usable. 相似文献
253.
Rudolf Izsák 《Environmental and Ecological Statistics》2008,15(2):143-156
In this paper some properties and analytic expressions regarding the Poisson lognormal distribution such as moments, maximum
likelihood function and related derivatives are discussed. The author provides a sharp approximation of the integrals related
to the Poisson lognormal probabilities and analyzes the choice of the initial values in the fitting procedure. Based on these
he describes a new procedure for carrying out the maximum likelihood fitting of the truncated Poisson lognormal distribution.
The method and results are illustrated on real data. The computer program for calculations is freely available.
相似文献
Rudolf IzsákEmail: |
254.
环境空气质量指数计算方法与分级方案比较 总被引:6,自引:4,他引:2
环境空气质量指数(AQI)广泛应用于各国环境空气质量评价体系之中,旨在为公众提供简单明了的空气质量信息和健康指引。通过对不同国家和地区空气质量指数的名称、计算方法、分级方案进行深入分析和比较,系统分析了各种空气质量指数的优缺点,并针对我国当前的空气质量指数体系存在的问题提出了相应的改进建议。 相似文献
255.
256.
Kinship and aggression: do house sparrows spare their relatives? 总被引:1,自引:0,他引:1
Zoltán Tóth Veronika Bókony Ádám Z. Lendvai Krisztián Szabó Zsolt Pénzes András Liker 《Behavioral ecology and sociobiology》2009,63(8):1189-1196
Kin-selection theory predicts that relatedness may reduce the level of aggression among competing group members, leading to
indirect fitness benefits for kin-favoring individuals. To test this hypothesis, we investigated whether relatedness affects
aggressive behavior during social activities in captive house sparrow (Passer domesticus) flocks. We found that sparrows did not reduce their aggression towards kin, as neither the frequency nor the intensity of
fights differed between close kin and unrelated flock-mates. Fighting success was also unrelated to kinship and the presence
of relatives in the flock did not influence the birds’ dominance rank. These results suggest that the pay-offs of reduced
aggression towards kin may be low in non-breeding flocks of sparrows, e.g. due to competition among relatives as predicted
by a recent refinement of kin-selection theory. Our findings indicate that the significance of kin selection may be restricted
in some social systems such as winter aggregations of birds.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
257.
遗传算法是一类借鉴自然界生物种群“自然选择、优胜劣汰”进化过程的启发式随机搜索优化算法,具通用性好、鲁棒性强等特点,被广泛地应用于通信网络设计领域,如度约束最小生成树问题.通过讨论遗传算法在度约束最小生成树问题中的应用,并对遗传算法在应用时存在的问题和挑战提出了见解.参17. 相似文献
258.
Jeffrey A. Bloczynski William T. Bogart Benjamin F. Hobbs Joseph F. Koonce 《Environmental management》2000,26(2):175-193
The model, a stochastic dynamic program, is used to optimize the timing and type of protective structure under a range of
management goals. A wetland can either be optimal for fish or optimal for mammals and waterfowl, but not both. Because credible
estimates of the economic values of wetland services do not exist, we treat those values as parameters in a multiobjective
analysis and show the decisions implied by alternative valuations. The model is applied to the case of Metzger Marsh, a Lake
Erie coastal wetland near Toledo, Ohio, where the decision was made in 1993 to construct an open dike. We find that the optimal
decision is robust with respect to varying assumptions about the formation of barrier beaches and the probability of climate
change, but that the decision is not robust to assumptions concerning the health of an unprotected Metzger Marsh. The most
important source of uncertainty is the biological health of an unprotected wetland. 相似文献
259.
260.
The effectiveness of genetic bioaugmentation relies on efficient plasmid transfer between donor and recipient cells as well as the plasmid’s phenotype in the recipient cell. In the present study, the effects of varying organic carbon substrates, initial recipient-to-donor cell density ratios, and mixtures of known recipient bacterial strains on the conjugation and function of a TOL plasmid were tested in sterile soil slurry batch reactors. The presence of soil organic carbon was sufficient in ensuring TOL plasmid transconjugant occurrence (up to 2.1 ± 0.5%) for most recipient strains in soil slurry batch mating experiments. The addition of glucose had limited effects on transconjugant occurrence; however, glucose amendment increased the specific toluene degradation rates of some Enterobacteriaceae transconjugants in soil slurry. Initial cell density ratios and mixtures of recipient strains had smaller impacts on plasmid conjugation and resulting phenotype functionality. These observations suggest that genetic bioaugmentation may be improved by minimal altering of environmental conditions. 相似文献