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601.
The challenge of pursuing sustainability in agriculture is often viewed as mainly or wholly technical in nature, requiring the reform of farming methods and the development and adoption of alternative technologies. Likewise, the purpose of sustainability is frequently cast in utilitarian terms, as a means of protecting a valuable resource (i.e., soil) and of satisfying market demands for healthy, tasty food. Paul B. Thompson has argued that the embrace of these views by many in the consumer/environmental movement enables easy co-optation by agribusiness. It also reflects a critical weakness in this movement: a lack of commitment to philosophical principles that depart from the utilitarian premises of the industrial model of agriculture. This paper draws on the writings of Thomas Berry and Liberty Hyde Bailey to identify the philosophical principles of what we call planetary agrarianism. From the perspective of planetary agrarianism, the pursuit of sustainability is a broad and challenging moral, educational, and political task. Berry helps us see that it is fundamentally a project of worldview transition, which requires a new cultural narrative that must rival, in form and appeal, the mythic power of the utilitarian industrial vision. Liberty Hyde Bailey, author of The Holy Earth (1915) and a leader in the land-grant education and nature-study movements, took up the project of worldview transition in his life work. While in some ways dated and flawed, Bailey’s writings are a valuable source of guidance for developing and pursuing a viable philosophy of agriculture for the 21st century. 相似文献
602.
Leclaire S White J Arnoux E Faivre B Vetter N Hatch SA Danchin E 《Die Naturwissenschaften》2011,98(9):773-782
Carotenoid pigments are important for immunity and as antioxidants, and carotenoid-based colors are believed to provide honest
signals of individual quality. Other colorless but more efficient antioxidants such as vitamins A and E may protect carotenoids
from bleaching. Carotenoid-based colors have thus recently been suggested to reflect the concentration of such colorless antioxidants,
but this has rarely been tested. Furthermore, although evidence is accruing for multiple genetic criteria for mate choice,
carotenoid-based colors have rarely been shown to reflect both phenotypic and genetic quality. In this study, we investigated
whether gape, tongue, eye-ring, and bill coloration of chick-rearing black-legged kittiwakes Rissa tridactyla reflected circulating levels of carotenoids and vitamins A and E. We further investigated whether integument coloration reflected
phenotypic (body condition and fledging success) and genetic quality (heterozygosity). We found that the coloration of fleshy
integuments was correlated with carotenoid and vitamin A levels and fledging success but only in males. Furthermore, the coloration
of tongue and eye-ring was correlated with heterozygosity in both males and females. Integument colors might therefore be
reliable signals of individual quality used by birds to adjust their parental care during the chick-rearing period. 相似文献
603.
604.
Previous research has debated whether the collective climates, produced through cluster analysis of psychological climate perceptions, are representative of meaningful organizational collectives or simply statistical artifacts. In this study we examined the extent to which collective climates are comprised of individuals with similar interpretive schemata such as work values and need strength or consist of individuals who share work group or interaction group membership. Measures of psychological climate, work values, need strength, and employee interaction patterns were collected from the management and administrative staff of a manufacturing organization. Results supported the symbolic interactionist perspective to the formation of collective climates. We found clear evidence that collective climates are related to employee interaction groups. Employee interaction based on sensemaking and information seeking activities was most strongly related to shared climate perceptions. There was also some evidence that individuals with similar levels of need strength share collective climate membership. Implications of these results on the debate over the use of collective climates are discussed. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
605.
Critical Success Factors for Behavior-Based Safety: A Study of Twenty Industry-wide Applications 总被引:2,自引:0,他引:2
One-on-one interviews and focus-group meetings were held at 20 organizations that had implemented a behavior-based safety (BBS) process in order to find reasons for program success/failures. A total of 31 focus groups gave 629 answers to six different questions. A content analysis of these responses uncovered critical information for understanding what employees are looking for in a BBS program. A perception survey administered to individual employees (n = 701) at these organizations measured a variety of variables identified in prior research to influence success in safety efforts. The survey data showed five variables to be significantly predictive of employee involvement in a BBS process: 1) perceptions that BBS training was effective; 2) trust in management abilities; 3) accountability for BBS through performance appraisals; 4) whether or not one had received education in BBS; and 5) tenure with the organization. Also, employees in organizations mandating employee participation in a BBS process (n=8 companies) reported significantly higher levels of: (a) involvement; (b) trust in management; (c) trust in coworkers; and (d) satisfaction with BBS training than did employees whose process was completely voluntary (n = 12 companies). In addition, employees in mandatory processes reported significantly greater frequency of giving and receiving positive behavior-based feedback. 相似文献
606.
Findings in multiattribute decision research were used as a basis for predicting the effects of help-wanted advertisement characteristics on vacancy attractiveness. In the first experiment, undergraduate students were presented with entry-level service job advertisements differing in attribute set size, attribute relevance, and pay ambiguity. Results revealed strong evidence for a set-size effect, with ads containing more (relevant or irrelevant) attributes increasing the attractiveness of the vacancies being advertised. Pay ambiguity decreased the attractiveness of vacancies with ads containing a small set of attributes. A second experiment presented students with the same advertisements, except that the small-set ads were physically enlarged to equal the size of the large-set ads. Results replicated the (large) set-size effect only for relevant-attribute ads. Also, pay ambiguity increased the attractiveness of vacancies promoted by ads containing a larger amount of relevant attributes. We conclude that merely adding relevant attribute information to help-wanted advertisements can lead to the inference that the jobs promoted in the ads are more attractive. Moreover, we tentatively suggest that pay ambiguity can lead to pessimistic inferences about pay for ads containing less information, and optimistic inferences about pay for ads containing more information. © 1998 John Wiley & Sons, Ltd. 相似文献
607.
In semiarid ecosystems, physiography (landscape setting) may interact with woody-plant and soil microbe communities to constrain seasonal exchanges of material and energy at the ecosystem scale. In an upland and riparian shrubland, we examined the seasonally dynamic linkage between ecosystem CO2 exchange, woody-plant water status and photosynthesis, and soil respiration responses to summer rainfall. At each site, we compared tower-based measurements of net ecosystem CO2 exchange (NEE) with ecophysiological measurements among velvet mesquite (Prosopis velutina Woot.) in three size classes and soil respiration in sub-canopy and inter-canopy micro-sites. Monsoonal rainfall influenced a greater shift in the magnitude of ecosystem CO2 assimilation in the upland shrubland than in the riparian shrubland. Mesquite water status and photosynthetic gas exchange were closely linked to the onset of the North American monsoon in the upland shrubland. In contrast, the presence of shallow alluvial groundwater in the riparian shrubland caused larger size classes of mesquite to be physiologically insensitive to monsoonal rains. In both shrublands, soil respiration was greatest beneath mesquite canopies and was coupled to shallow soil moisture abundance. Physiography, through its constraint on the physiological sensitivity of deeply rooted woody plants, may interact with plant-mediated rates of soil respiration to affect the sensitivity of semiarid-ecosystem carbon exchange in response to episodic rainfall. 相似文献
608.
Environmental variability can promote coexistence by creating establishment sites for rare plants, but low diversity in anthropogenic grasslands suggests that this variability may be eliminated (homogenization hypothesis) or inaccessible (barrier hypothesis). We explore these alternatives on the northern Great Plains, where 11 million hectares have been transformed by multiple environmental changes, but the causes of species loss are unclear. In a degraded grassland, we increased environmental variability by manipulating competition and herbivory along gradients of fertility and disturbance, and we circumvented dispersal barriers by adding 1.2 million seeds of five functionally distinct species at varying densities. The experiment ended after 12 weeks due to the direct and indirect effects of unapparent small native herbivores, which were barriers to population establishment by the added species. The direct cause of recruitment failure was browsing. The indirect cause was associated with competition from invasive plants that appeared to be more tolerant or resistant to herbivory. Variability in fertility, disturbance, propagule pressure, and competition had relatively minor impacts on colonization by the added species because herbivores controlled recruitment in most environments. Recruitment outside the herbivore exclosures was mostly by unpalatable exotics, suggesting a possible link between invasion success and herbivore resistance for some introduced plants. 相似文献
609.
Michelle L Kissling Mason Reid Paul M Lukacs Scott M Gende Stephen B Lewis 《Ecological applications》2007,17(8):2164-2174
The Kittlitz's Murrelet (Brachyramphus brevirostris) is a rare, non-colonial seabird often associated with tidewater glaciers and a recent candidate for listing under the Endangered Species Act. We estimated abundance of Kittlitz's Murrelets across space and time from at-sea surveys along the coast of Alaska (USA) and then used these data to develop spatial models to describe abundance patterns and identify environmental factors affecting abundance. Over a five-week period in the summer of 2005, we recorded 794 Kittlitz's Murrelets, 16 Marbled Murrelets (B. marmoratus), and 70 unidentified murrelets. The overall population estimate (N, mean +/- SE) during the peak period (3-9 July) was 1317 +/- 294 birds, decreasing to 68 +/- 37 by the last survey period (31 July-6 August). Density of Kittlitz's Murrelets was highest in pelagic waters of Taan Fjord (18.6 +/- 7.8 birds/km2, mean +/- SE) during 10-16 July. Spatial models identified consistent "hotspots" of Kittlitz's Murrelets, including several small areas where high densities of murrelets were found throughout the survey period. Of the explanatory variables that we evaluated, tidal current strength influenced murrelet abundance most consistently, with higher abundance associated with strong tidal currents. Simulations based on the empirically derived estimates of variation demonstrated that spatial variation strongly influenced power to detect trend, although power changed little across the threefold difference in the coefficient of variation on detection probability. We include recommendations for monitoring Kittlitz's Murrelets (or other marine species) when there is a high degree of uncertainty about factors affecting abundance, especially spatial variability. 相似文献
610.
D. Agosti C. Austin O. A. Gökçen W. A. König E. D. Morgan E. D. Scott R. Wehner 《Chemoecology》1996,7(1):57-60
Summary In all the species of theCataglyphis bicolor group examined yet, i.e.C. bicolor, C. diehli, C. isis, C. nodus, andC. viaticus, 2-methyl-1-hexanol is the characteristic substance and almost the only substance found in the mandibular glands. Its chirality has been determined inC. bicolor and shown to be exclusively (S)-2-methyl-1-hexanol. 相似文献