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51.
Judith A. Pickering Richard A. Andrews 《Journal of the American Water Resources Association》1979,15(4):1039-1049
ABSTRACT: The objective of the study was to evaluate alternative land developments around New Hampshire lakes. Alternative development patterns, evaluated by their impacts on the lake area environment and area economy, included residential patterns, commercial patterns, and combinations of these two types. Phosphorus loading of the lake water was used as a proxy variable for changes in the lake water quality. Commercial developments yielded the highest revenues to the town and the local area. It also attracted the most lake users to the area as well as contributing the largest phosphorus loading in the lake waters. Residential developments, although contributing high revenues to the businessmen in the area, yielded less net income to the town. Phosphorus loading levels from residential developments were much lower than lake phosphorus loading by commercial developments. 相似文献
52.
S. F. Shih 《Journal of the American Water Resources Association》1980,16(4):724-727
ABSTRACT: The water budget computation in shallow lakes is complicated because marsh vegetation can transpire large quantities of lake water. Thus, a model including the marsh zone evapotranspiration (WET) was developed to compute the water budget for Lake Okeechobee. Three periods of testing (1969–74), planning (1963–74), and recorded period (1952–77) were used to compare the differences of the sum of storage deviation between the WET and conventional methods (WOET). Results of the WOET method showed that the sum of stage deviations were 87.42 cm (2.868 ft.), 231.80 cm (7.605 ft.), and 284.50 cm (9.333 ft.) in the testing, planning, and recorded periods, respectively. These stage deviations are equivalent in the same order to 29, 76, and 93 percent of the lake volume. In general, the WET method not only was applicable to compute the water budget for the lake but also reduced the sum of storage deviation by about 42, 31, and 49 percent, respectively, in those three periods. The storage deviation in WET method was reduced on an average to about 2 percent each year in all three periods, and the deviations were scattered more randomly than in WOET. 相似文献
53.
ABSTRACT: To investigate the magnitude of denitrification and assimilatory nitrate reduction as these reactions relate to the fate of nitrate reaching sediments via groundwater seepage, undisturbed core samples of sediments (40 cm length) from two lakes (Mendota and Tomahawk) were leached from the bottom (at 1.4 cm/day) with a solution of 15N-nitrate (10 mg N/liter). The sediment columns were fitted with Pt electrodes to measure the oxidation-reduction (Eh) potential. While leaching removed considerable ammonium-N and soluble organic N, essentially no 15N had passed through the columns by 50 days. The Eh readings indicated that denitrification was occurring in the lower portions of the columns. The 15N distribution of the sediment N after 50 days showed that about 15 to 26% of the added nitrate-N was converted to organic N and ammonium-N. The data show that denitrification can be a significant N sink in seepage lakes. 相似文献
54.
Gail Krantzberg 《The Environmentalist》2008,28(3):301-305
Some argue that a collective vision for the future of the Laurentian Great Lakes is embodied in the␣Great Lakes Water Quality
Agreement (GLWQA). The GLWQA is a binational agreement, first signed in 1972 by Prime Minister Pierre Trudeau and President
Richard Nixon, wherein the two countries (the Parties) commit to “restore and maintain the chemical, physical and biological
integrity of the waters of the Great Lakes Basin Ecosystem.” Article X of the Agreement states that the Parties shall conduct
a comprehensive review of the operation and effectiveness of this Agreement following every third biennial report of the [International
Joint] Commission (IJC). The IJC’s 12th Biennial Report, released in 2004, triggered this important science, program, and
policy review which commenced May 2006. This essay makes the case for a rigorous review, that explores deliberately the future
scope of the Agreement to protect the world’s largest surface freshwater resource, and calls for innovation in the governance
regime of this binational ecosystem. 相似文献
55.
Resolution and Analysis of Spatial Variations and Patterns in an Urban Lake with Rapid Profiling Instrumentation
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Anthony R. Prestigiacomo Steven W. Effler David A. Matthews 《Journal of the American Water Resources Association》2015,51(1):200-213
Rapid response vertical profiling instrumentation was used to document spatial variability and patterns in a small urban lake, Onondaga Lake, associated with multiple drivers. Paired profiles of temperature, specific conductance (SC), turbidity (Tn), fluorometric chlorophyll a (Chlf), and nitrate nitrogen (NO3?) were collected at >30 fixed locations (a “gridding”) weekly, over the spring to fall interval of several years. These gridding data are analyzed (1) to characterize phytoplankton (Chlf) patchiness in the lake's upper waters, (2) to establish the representativeness of a single long‐term site for monitoring lake‐wide conditions, and (3) to resolve spatial patterns of multiple tracers imparted by buoyancy effects of inflows. Multiple buoyancy signatures were resolved, including overflows from less dense inflows, and interflows to metalimnetic depths and underflows to the bottom from the plunging of more dense inputs. Three different metrics had utility as tracers in depicting the buoyancy signatures as follows: (1) SC, for salinity‐enriched tributaries and the more dilute river that receives the lake's outflow, (2) Tn, for the tributaries during runoff events, and (3) NO3?, for the effluent of a domestic waste treatment facility and from the addition of NO3? solution to control methyl mercury. The plunging inflow phenomenon, which frequently prevailed, has important management implications. 相似文献
56.
参考价格理论是构建价格判断模型的传统理论,其价格判断模型是一种典型的推理性模型.根据双系统理论,人们的决策应是推理性和直觉性两类过程的交互作用,心理账户理论正是描述直觉性决策的基本理论之一.构建了基于参考价格与心理账户的双系统价格判断决策模型,对不同心理账户数据进行分析发现,被试者的目标价格决策过程具有显著差异. 相似文献
57.
58.
C. C. Li 《Chemistry and Ecology》1996,12(1):57-66
Water quality was monitored for 12 months in Lake Tai and Lake Zon on Kinmen Island, Taiwan, and physico-chemical conditions were analyzed. No vertical temperature stratification was observed in these shallow lakes. pH is neutral to alkaline and associated with vigorous algal growth. Nitrogen levels are high and present in various forms due to progressive nitrification. Green and blue-green algae play an important part in the process of nitrification.
Assessment of lake eutrophication was made by the use of the N:P ratio, the Trophic State Index (TSI) and the US EPA Eutrophic Screening Model. the result of these calculations indicates eutrophic conditions in both lakes. It is advised that lake restoration be initiated and available techniques are listed. 相似文献
Assessment of lake eutrophication was made by the use of the N:P ratio, the Trophic State Index (TSI) and the US EPA Eutrophic Screening Model. the result of these calculations indicates eutrophic conditions in both lakes. It is advised that lake restoration be initiated and available techniques are listed. 相似文献
59.
为了更好地从基因角度研究亚硝态氮对贝类的生态毒性,需要筛选一个合适的内参基因作为参考,对其毒性相关基因进行定量表达分析。本研究以菲律宾蛤仔(Ruditapes philippinarum)作为研究对象,以亚硝态氮胁迫的鳃组织cDNA作为模板,利用geNorm软件和NormFinder软件对6个候选内参基因进行表达稳定性分析,并对2个结果做了综合赋权分析。结果显示,geNorm分析的基因表达稳定性结果为ActinCyPAEF1αUbi18STubu,NormFinder软件分析的结果为ActinUbiCyPAEF1α18STubu,最后经加权赋值法综合分析获得6个候选基因的表达稳定性为ActinCyPAUbiEF1α18STubu,即Actin为表达最稳定的基因。因此,Actin可以作为衡量亚硝态氮胁迫后菲律宾蛤仔鳃组织中基因表达的内参基因。 相似文献
60.
The use of heuristic judgments is prevalent in organizations and negatively impacts accurate employee assessments. To minimize the negative impact of heuristic judgments (i.e., anchoring and adjustment), we aim to improve rating accuracy by restructuring frame‐of‐reference (FOR) training. We conducted five studies (N = 1,143) using different samples (three including participants with hiring experience), training environments (onsite and online), and rating contexts (evaluations of sales representatives, teachers, contract negotiation specialists, and retail store managers). Across the five studies, the average improvement in rating accuracy was at least twice as large for restructured FOR (vs. control) training as it was for typical FOR (vs. control) training; the difference in rating accuracy between restructured and typical FOR training was statistically significant. Furthermore, minimizing the anchoring effect rather than increasing opportunities for rating adjustments improved rating accuracy (Study 4). Finally, restructured FOR training achieved higher criterion validity (i.e., a higher strength of the association between ratings regarding a target and the target's objective performance) than did typical FOR training (Studies 3 and 5). We discuss implications for improving the effectiveness of diverse training programs and the accuracy of judgments in organizations. 相似文献