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471.
ABSTRACT: Federal and state governments in the United States and Australia have come to play a key role in attempts to mitigate the impact of drought. Government actions have usually taken the form of loans and grants to individual citizens, businesses and municipalities experiencing the hardship of drought. Most of these actions have occurred in an environment of crisis management, rather than as a result of clearly stated policy objectives. Based on a review and evaluation of recent drought policy in the United States and Australia, recommendations are offered on ways to improve the United States’approach. A national drought plan is suggested as an efficient mechanism through which these recommendations could be implemented. States should also become more actively involved in drought assessment and response, but these actions must be coordinated with federal actions.  相似文献   
472.
叙述了环境突发事件应急处理工作程序和流程,环境应急指挥基于GIS系统下各模块的功能作用。应急指挥系统的应用对减少突发环境污染事故的发生以及事故造成的社会、环境危害,提高中国应对突发事故的能力具有重要的社会效益。  相似文献   
473.
The proteomic analysis of rice (Oryza sativa L.) roots and leaves responding tol,2,4-trichlorobenzene (TCB) stress was carded out by two dimensional gel electrophoresis, mass spectrometric (MS), and protein database analysis. The results showed that 5 mg/L TCB stress had a significant effect on global proteome in rice roots and leaves. The analysis of the category and function of TCB stress inducible proteins showed that different kinds of responses were produced in rice roots and leaves, when rice seedlings were exposed to 5 mg/L TCB stress. Most responses are essential for rice defending the damage of TCB stress. These responses include detoxication of toxic substances, expression of pathogenesis-related proteins, synthesis of cell wall substances and secondary compounds, regulation of protein and amino acid metabolism, activation of methionine salvage pathway, and also include osmotic regulation and phytohormone metabolism. Comparing the TCB stress inducible proteins between the two cultivars, the β-glucosidase and pathogenesis-related protein family 10 proteins were particularly induced by TCB stress in the roots of rice cultivar (Oryza sativa L.) Aizaizhan, and the glutathione S-transferase and aci-reductone dioxygenase 4 were induced in the roots of rice cultivar Shanyou 63. This may be one of the important mechanisms for Shanyou 63 having higher tolerance to TCB stress than Aizaizhan.  相似文献   
474.
通过对三江自然保护区核心区内6个村屯和实验区内5个村屯的310家农户家庭就退耕还湿和替代生计选择的问卷调查分析发现,在退耕还湿问题上,不同区域位置、年龄结构和耕地拥有量决定了他们对退耕还湿支持意愿的不同,表现在实验区内的农民和农民中的年轻人支持率要高,耕地在6~12hm2之间的农民支持率最低;农民反对退耕还湿的原因和农民接受退耕还湿的补偿选择都凝结着农民对现有耕地及补偿制度的思考。在替代生计选择上,当地居民没有明确的目标,多倾向于有保障的种植业调整。研究表明:农民对退耕还湿的支持主要取决于能否保证自身的经济利益,并且与农民的收入来源和谋生能力有关;替代生计发展的不健全和不稳定,使得农民仍把土地作为重要的生活保障。缺乏明确的退耕还湿补偿制度和替代生计引导是退耕还湿实施的制度障碍和政策缺失;基于当地农民考虑,提出了核心区生态移民、缓冲区传统农业改造和实验区多元化产业发展总体替代生计模式。  相似文献   
475.
A series of tests (lethal, sublethal, and behavioral) on earthworms were conducted as an eco-assessment of pesticides. In this study, the toxicity of cypermethrin-contaminating soil on adult and juvenile earthworms was assessed. Beside the acute and chronic tests, an avoidance response test was carried out. It was shown that the all-round toxicity from cypermethrin was weak on adult earthworms. Compared with adult earthworms, the toxicity of juvenile earthworms from cypermethrin especially chronic toxicity increased significantly. Growth and reproduction of earthworms appeared to be more severely a ected by cypermethrin at juvenile stage than at adult stage. Applied at 10 mg/kg, cypermethrin had obvious adverse impact on the growth of juvenile earthworms, while 20 mg/kg, cypermethrin caused significant toxic e ects in reproduction. The results also indicated that ecotoxicological risk assessment using only adult specimens may underestimate the e ects of cypermethrin on soil invertebrate populations.  相似文献   
476.
纤维素酶液体发酵工艺条件的响应面分析优化   总被引:5,自引:0,他引:5  
借助于MINITAB软件,采用Plackett-Burman试验设计法及响应面法分析,对纤维素酶高产菌康氏木霉Trichoderma koningii P12进行了发酵工艺条件的优化研究。首先利用Plackett Burman试验设计筛选出影响产酶的三个主要因素,即装液量、稻草粉浓度和麦麸浓度。在此基础上用最陡爬坡路径逼近最大响应区域,再利用Box-Behnken试验设计及响应面分析法进行回归分析。结果表明,装液量和稻草粉浓度与纤维素酶活存在显著的相关性,通过求解回归方程得到优化发酵条件:当装液量56.5mL、稻草粉浓度37.4g/L和麦麸浓度11.3g/L时,纤维素酶产量达到63.32U/mL。经三批培养验证,预测值与验证试验平均值接近,在此优化条件下纤维素酶活提高了96.7%。  相似文献   
477.
传统的区域竞争力评价主要是侧重于经济指标,对生态环境要素涉及较少,在经济快速发展地区,生态环境已成为保证区域发展的重要基础条件。以安徽沿江地区为例,提出了生态环境竞争力的概念。以县(市、区)为评价基本单元,从生态环境压力、生态环境现状、经济发展需求和主动协调能力4个方面,设计了区域生态竞争力的评价指标体系,将各单元的生态环境竞争力水平分为5个等级:水平较高的地区主要位于南部、西部山地和合肥市区,竞争力水平较低的地区主要分布在和县-无为平原传统农业区和马鞍山、铜陵重工业区。生态环境竞争力不仅与自然生态系统的本底质量有关,也与区域经济技术水平、生态环境建设的投入水平、管理水平有关。最后对各区生态环境存在问题和提升优化途径进行了讨论。  相似文献   
478.
在风力载荷作用下,应用ANSYS 结构动力学有限元程序对球型储罐进行防风模拟分析,针对球型储罐的3种典型不连续结构,分别给出了球壳与盖板连接区域、支柱区域及拉杆区域的应力云图,并分析和对比了各区域的应力响应.  相似文献   
479.
The molecular response of wheat (Triticum aestivum L.,cv.Yangmai 10) seedlings to heavy metal (Cd,Hg) and 1,2,4-trichlorobenzene (TCB) stresses were examined by two-dimensional gel electrophoresis,image analysis,and peptide mass fingerprinting.The results showed inhibitions of root and shoot growth by Cd,Hg and TCB.These stresses led to water deficit and lipid phosphorylation in the seedling which also promoted protein phophorylation in the leaves.Hg stress inhibited protein synthesis while Cd and TCB stresses induced or up-regulated more proteins in the leaves.Most of these induced proteins played important roles in the biochemical reactions involved in tolerance of wheat to Cd and TCB stresses.The primary functions of Cd- and TCB-induced proteins included methionine metabolism,Rubisco modification,protein phosphorylation regulation,protein configuration protection,H+ transmembrane transportation and also the synthesis of ethylene defense substances and cell wall compounds.  相似文献   
480.
The experimental design methodology was applied for modeling and optimizing the operation parameters on photocatalytic degradation of chloramphenicol (CAP) using TiO2 as photocatalyst in a photoreactor. Three experimental parameters (including pH, TiO2 concentration and CAP initial concentration) were adopted to obtain the preliminary information. The multivariate experimental design was employed to establish a quadratic model as a functional relationship between the degradation rate of CAP and three experimental parameters. The interaction e ects and optimal parameters were obtained by using Design Expert software. The optimal values of the operation parameters under the related constraint conditions were found at pH 6.4, TiO2 concentration of 0.94 g/L and CAP initial concentration of 19.97 mg/L, respectively. The degradation rate of CAP approached 85.97% under optimal conditions. The regression analysis with R2 value of 0.9519 had a good agreement between the experimental results and the predictive values. In addition, pH and TiO2 concentration had a significant influence on the degradation rate of CAP.  相似文献   
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