首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   98篇
  免费   1篇
  国内免费   5篇
安全科学   12篇
废物处理   5篇
环保管理   10篇
综合类   9篇
基础理论   17篇
污染及防治   41篇
评价与监测   6篇
社会与环境   4篇
  2023年   1篇
  2022年   1篇
  2019年   3篇
  2018年   5篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   15篇
  2012年   6篇
  2011年   5篇
  2010年   8篇
  2009年   6篇
  2008年   12篇
  2007年   8篇
  2006年   11篇
  2005年   4篇
  2004年   2篇
  2003年   6篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1997年   1篇
  1991年   1篇
排序方式: 共有104条查询结果,搜索用时 359 毫秒
61.
Following the export success of the South Korean small modular reactor (SMR), it has been investigated for the marketing strategy of nuclear power plants (NPPs). The information feedback oriented method for the social-business matters, system dynamics (SD), is applied to the assessment of the marketing strategy in which the forecasting skills are performed. Each element has the Boolean value as 0 or 1 in which the values are selected by the random number generation. If the generated values are higher than the designed value decided by the operator, it is 1. Otherwise, it is 0. The networking based dynamical modeling is discussed. The modification of the linear networking is changed by the SD algorithm where the feedback and multiple connections are added to the original network dynamics theory. This new method has shown the complexity of the marketing strategy, especially for the NPPs.  相似文献   
62.
We theorized and tested the mechanisms by which leader–member exchange (LMX) quality is associated with job performance. The results obtained using 212 employee–supervisor pairs from eight Chinese companies indicated that LMX quality had an indirect and positive relationship with taking charge via psychological empowerment and had an indirect and positive relationship with job performance via taking charge. In addition, organizational tenure significantly moderated the relationship between taking charge and job performance, such that the positive effect of taking charge on job performance became weaker as organizational tenure increased. Furthermore, organizational tenure significantly moderated the indirect positive relationship between LMX quality and job performance via taking charge; the indirect effect became weaker as organizational tenure increased. These results suggest that organizations should encourage managers to develop high‐quality LMX with their subordinates, which may make them feel more empowered and engage in more taking charge, and result in better job performance. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
63.
64.
A mathematical model was developed to describe phenol degradation in an anaerobic fixed-biofilm process. The model incorporates the mechanisms of diffusive mass transport and Monod kinetics. The model was solved using a combination of the orthogonal collocation method and Gear's method. A pilot-scale column reactor was used to verify the model. Batch kinetic tests were conducted independently to determine the biokinetic parameters used in the model, while shear loss and initial thickness of biofilm were assumed so that the model simulated the substrate concentration results well. The removal efficiency for phenol was approximately 98.5% at a steady-state condition. The model accurately described the effluent substrate concentrations and the sequence of biodegradation in the reactor. The model simulations are in agreement with the experimental results. The approaches presented in this paper could be used to design fullscale anaerobic fixed-biofilm reactor systems for the biodegradation of phenolic substrates.  相似文献   
65.
The complexation of Cu with phenol was investigated in aqueous solution to find the changes in toxicity toward Daphnia magna in mixtures of copper and phenol derivatives and determine an appropriate prediction model for the toxicity of these mixtures. In the titration experiment, the results showed that phenol played an important role in the remarkable reduction of the Cu(2+) concentration, due to its complexation with Cu, with the subsequent reduction in the toxicity of aqueous mixtures containing both Cu and phenol. As a result, it was clearly demonstrated that Cu-phenol formed a non-toxic complex toward D. magna as the mortality declined, despite the addition of phenol to a fixed Cu concentration. Meanwhile, prediction of the combined toxicity for binary mixtures of Cu and 11 phenol derivatives more accurately followed an independent action model (p = 0.143, df = 124, and t = -1.475 in t-test) than an effect summation model (p approximately 0, df = 134, and t = 7.528 in t-test) due to the dissimilar modes of action and the complexation reactions between Cu and each of the phenolic compounds. Consequently, this study supports the importance of considering complexation reactions in assessing the combined toxicity for the formulation of water quality in mixtures of heavy metals and organic compounds, and in these cases, an independent action model was found to be appropriate.  相似文献   
66.
The safety assessment of an accident in the lunar base power plant is investigated for the stability of the operation. The lunar surface reactor is modeled for this study. The accident of cooling loop failure (ACLF) is one of the important scenarios for the virtual case in the moon nuclear power plant (NPP). The newly designed lunar nuclear power reactor (LNPR) is suggested for the commercial purpose. The system dynamics (SD) is used for the simulation of the safety assessment. The cyclic variation of the lunar surface temperature can affect to the physical situation of the coolant, which is expressed by the time step. The result shows the performance possibility of the long term cooling increases slightly in the short period of the time step. The dynamical simulation of the lunar environment is performed for the conceptual design of the NPP.  相似文献   
67.
Semilunar or lunar reproductive rhythms that follow tidal cycles are common in marine animals. For brachyuran crabs, an adaptive explanation for the synchronous release of larvae in phase with the tidal cycle is that females release larvae when their offspring are best able to escape predators. As a corollary to this hypothesis, the synchronous male reproductive cycle is selected to be in phase with female receptivity. As an alternative hypothesis, we propose that variation in food abundance influences the onset and intensity of the semilunar courtship cycle. We tested this hypothesis in male fiddler crabs ( Uca lactea) by experimentally manipulating food availability for 4 weeks. Food-supplemented males built more semidomes and waved for more days than did food-deprived males or untreated control males. Moreover, food-supplemented males began courtship earlier and the median courtship day advanced with an increase in food. Courtship intensity was not related to crab size. These results provide the first evidence in marine animals that changes in food abundance due to the tides, and hence in phase with the semilunar cycle, influence male reproductive rhythm.  相似文献   
68.
Lee HS  Kim YA  Cho YA  Lee YT 《Chemosphere》2002,46(4):571-576
A potentiometric flow injection-type biosensor developed in our laboratory was used for the determination of organophosphorus pesticides (OPs). The principle of the biosensor is that the degree of inhibition of a sensor enzyme by an OP is dependent on the concentration of the pesticide. The sensor system consisted of a reactor with acetylcholinesterase (AChE) immobilized on a controlled pore glass and a detector with a tubular H(+)-selective membrane electrode. In order to examine the possibility of enhancing the sensitivity of the sensor by converting OPs to oxidized forms (stronger inhibitors), a comparison of the degree of enzyme inhibition by OPs at 10(-6) M before and after their oxidation was made. All of the ten pesticides tested exhibited greater inhibitory power toward the sensor enzyme following oxidation. All of the oxidized pesticides at 10(-6) M inhibited the sensor enzyme to a considerable degree, demonstrating the utility of the developed method for the class-specific determination of OPs. A calibration curve for diazinon, over the concentration range of 10(-11)-10(-4) M, was obtained. The lower detection limit was 2 x 10(-10) M. Treatment of the inhibited enzyme with pyridine-2-aldoxime restored the enzyme to near full activity, allowing repeated use of the sensor.  相似文献   
69.
In the current study, the potential of forest-based biomass supply for the pellet production in Nepal is investigated. This study showed that about 2.76 million tonnes (Mt) biomass in the form of pellets are potentially available from forest-based biomass. Considering a processing capacity of 6 tonnes (t)/hr of a pellet plant, the production cost of the pellets was calculated to be $43.53/t. Pellets are generally used as fuel to produce thermal energy in industries, which helps to save the economy and the environment of the country.  相似文献   
70.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号