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MaryCarol Rossiter Diana Cox-Foster Mamdouh M. Abou-Zaid Diane Bergeron 《Chemoecology》1996,7(2):74-84
Summary A standard buffer (5 mM phosphate at pH 7) which is used to extract protein from insect eggs provided complete protein solubility for eggs from three of four tree-feeding lepidopteran species: obliquebanded leaf roller (Choristoneura rosaceana), forest tent caterpillar (Malacosoma disstria), and the eastern tent caterpillar (Malacosoma americanum). Under the same extraction protocol, egg proteins from the gypsy moth (Lymantria dispar), remained nearly insoluble. An array of methods typically used to solubilize insect egg proteins were tried and all but the most denaturing (2% SDS) were ineffective. Extraction buffers with typically high pH values were then evaluated. The results indicated that 1) solubility of gypsy moth egg proteins was pH dependent, and full solubility of most egg proteins required the extraction buffer to have a pH of 12 or more prior to the addition of eggs. We also determined that 2) the gypsy moth egg has a buffering capacity which must be surpassed for complete protein extraction, 3) low salt/high pH buffers gave slightly higher total protein values than did high salt/high pH buffers, 4) parental nutritional history (host species utilized) and egg developmental state (pre-embryonatedvs postembryonated/pre-hatch) were unrelated to the requirements for complete egg protein solubilization, and 5) the presence of soluble phenolics, compounds that have the potential to bind to protein and cause insolubility, was confirmed for the gypsy moth egg with 2-D paper chromatography and several other tests. Based on these results, we present a hypothesis about the cause of egg protein insolubility in the gypsy moth. 相似文献
994.
The present study utilizes meta‐analytic techniques to examine the literature on sleep and work performance. In line with previous meta‐analytic research, results indicate that sleep and work performance have a positive relationship. However, more importantly, results from moderator analyses reveal that the type of sleep measurement (sleep quantity and sleep quality), work performance measurement (task performance, organizational citizenship behavior, and counterproductive work behavior), analysis method (between‐person and within‐person), sleep report source (self‐report, other report, and objective), sleep recall window (day, week/month, and more than 1 month), and study setting (field and laboratory) differentially influence the strength of the sleep–work performance relationship. Furthermore, meta‐analytic SEM results indicate that certain mediators (affect, job attitudes, and cognitive resources) provide stronger explanations (i.e., stronger indirect effects) for the relationship between sleep and work performance, depending on the specific type of performance being examined. In general, results highlight the importance of construct operationalization and methodology decisions when conducting sleep–work performance research and provide greater insight into explanations for the relationship between sleep and work performance. Research implications, practical implications, potential limitations, and future directions are also discussed. 相似文献
995.
Primary and secondary components of PM2.5 in Milan (Italy) 总被引:1,自引:0,他引:1
In sampling campaigns--carried out by means of a high-volume gravimetric sampler--performed between August 2002 and December 2003, 24-h PM2.5 samples have been collected at an urban background site in downtown Milan and analyzed for elemental and organic carbon, ionic species (i.e., chloride, nitrates, sulfates and ammonium) and some elemental species. Chemical speciation data are evaluated also in terms of primary and secondary components of fine particulate matter: in particular, the contribution of secondary organic aerosols (SOA) and of the primary contribution from traffic to observed PM2.5 concentration levels are evaluated by means of the EC tracer method. 相似文献
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997.
《组织行为杂志》2017,38(3):415-438
Combining the macro perspective of strategic human resource (HR) management with applied psychology's micro approaches, this paper helps to differentiate the effects of HR practices on individual‐level outcomes by introducing two distinct HR practice bundles. We draw on social exchange theory to hypothesize (i) main effects of both growth‐enhancing and maintenance‐enhancing bundles on affective organizational commitment and in‐role behavior and (ii) moderating effects of age and maintenance‐enhancing practices on work outcomes, such that increasing employee age attenuates the positive impact of HR practices. The results of a multilevel study comprising 600 employees and their direct supervisors in 64 business units provide support for the hypothesized main effects on affective commitment and the interaction between age and maintenance‐enhancing practices on work outcomes. We discuss the results, theoretical contributions, and practical implications of the study, as well as future research directions. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
998.
《组织行为杂志》2017,38(3):391-414
Building on the premises of the conservation of resources theory, the aim of this study was to investigate long‐term effects of job resources on vigor among native and immigrant employees in Israel. More specifically, we investigated the effects of baseline and change in job control and supervisor support on change in vigor levels, as well as the degree to which these effects differ among educated native and immigrant employees in Israel. We surveyed 235 white‐collar Eastern European and Russian immigrants and 235 white‐collar native Israelis matched on occupational and demographic characteristics at two points of measurement with a 30‐month time lag. Latent change score modeling revealed that among both immigrants and natives, change in job control was related to change in vigor. Multiple group analyses further revealed that among immigrant employees only, baseline levels of supervisor support were associated with change in vigor. In conclusion, these findings suggest that the utilization of resources as a means of acquiring new resources may be influenced by immigrant background. Managerial implications are discussed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
999.
《组织行为杂志》2017,38(6):895-916
Prior literature examining the antecedents of employee affect has largely ignored subtle affective influences in the workplace and their impact on employees' affective experiences and behaviors. A substantial body of evidence from basic psychology research suggests that individuals' affect can be influenced by minimal stimulus input. The primary objective of this research is to take an initial step towards understanding the “real‐world” impact of subtle affective stimuli in the workplace. Specifically, in a field experiment with a within‐subjects design, we collected data from 68 sales representatives and examined the effect of a subtle affective stimulus (i.e., a black‐and‐white picture of a woman smiling printed on the backdrop of paper–pencil surveys) on employees' affect, well‐being, and performance. Results showed that the smiling picture significantly enhanced participants' positive affect, which in turn influenced employees' extra‐role performance and emotional exhaustion. The smiling picture also indirectly influenced employees' in‐role performance and emotional exhaustion via negative affect. Theoretical and practical implications of these findings are discussed at the end of the paper. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
1000.
《组织行为杂志》2017,38(8):1227-1245
The not‐invented‐here (NIH) syndrome has been called one of the largest obstacles in innovation management, preventing effective knowledge transfer between organizational units and individuals. NIH is defined as a negatively shaped attitude towards knowledge that has to cross a disciplinary, spatial, or organizational boundary, resulting in either its suboptimal utilization or its rejection. Our goal is to equip scholars with appropriate measurement instruments for the phenomenon. On the basis of 4 studies with 1,238 subjects overall, we developed an implicit measure based on the implicit‐association test as well as an explicit (survey) measure of NIH, taking into account theoretical insights on attitude structure. We provide evidence for reliability as well as construct and criterion validity. We want to facilitate further research on NIH and knowledge transfer (a) by providing a better theoretical framework for NIH on the basis of the tripartite componential model of attitudes, (b) by demonstrating the application of association‐based implicit measures for management research, and (c) by providing a validated multidimensional survey scale to measure NIH explicitly. We also provide recommendations on how managers can utilize the NIH measurement instruments to investigate NIH and potential countermeasures in detail and they can test the behavioral outcomes postulated by previous research. 相似文献