全文获取类型
收费全文 | 161篇 |
免费 | 9篇 |
国内免费 | 24篇 |
专业分类
安全科学 | 18篇 |
废物处理 | 8篇 |
环保管理 | 29篇 |
综合类 | 58篇 |
基础理论 | 33篇 |
污染及防治 | 17篇 |
评价与监测 | 10篇 |
社会与环境 | 11篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 13篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 13篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 3篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有194条查询结果,搜索用时 187 毫秒
141.
The impacts of production disruption in Remanufacturing/Manufacturing (R/M) integrated supply chain on the sales and the methods of production disruption management were studied. A system dynamics model for the R/M integrated supply chain with production disruption was improved by system dynamics methodology. The numerical examples were shown to illustrate the simulation results. The impacts of different recovery times of production disruption on the sales were presented. In order to mitigate the disruption risks and ensure the sales at the needed sales ratio, the methods for setting multi-echelon inventory levels before the occurring of the production disruption and the methods for making back-up plans after the production disruption occurs were given. 相似文献
142.
山东省区域经济差异趋势研究 总被引:1,自引:0,他引:1
改革开放以来,山东经济总量稳步扩大,人民生活水平显著提高,2004年以后该省GDP占全国第二,人均国民生产总值名列前茅。一个地区的区域经济发展平衡状况在很大程度上影响着总体经济的发展。从区域经济差异内涵出发,根据基尼系数和R/S分析法对山东省17个区域的经济差异进行了定量评价和趋势预测,提出了区域经济协调对策。 相似文献
143.
研发能力与研发效率的比较研究——以河南省大中型工业企业为例 总被引:1,自引:0,他引:1
通过构建大中型工业企业研发能力与效率的评价指标体系,运用因子定权法,对河南省18个地市的大中型工业企业研发能力与效率区域差异进行了测度和分析。研究发现,河南省大中型工业企业研发能力与效率整体协调性差,部分地区研发能力的获取是以牺牲研发效率为代价的;自主创新支撑能力、资本投入、环境约束是影响河南省大中型工业企业研发能力与效率的关键因素,而人力资本投入权重相对较小,说明河南省大中型工业企业的研发软实力有待提高。 相似文献
144.
Stankov Jovanovic VP Ilic MD Markovic MS Mitic VD Nikolic Mandic SD Stojanovic GS 《Chemosphere》2011,84(11):1584-1591
Fire has been considered as an improving factor in soil quality, but only if it is controlled. Severe wild fire occurred in the summer 2007 on the Vidlic Mountain (Serbia) overspreading a huge area of meadows and forests.Main soil characteristics and content of heavy metals (Cu, Pb, Cd, Zn) in different fractions obtained after sequential extraction of soil from post-fire areas and from fire non disturbed areas were studied. In four plant species of Lamiaceae family (Ajuga genevensis L., Lamium galeobdolon (L.) L., Teucrium chamaedrys L., Acinos alpinus (L.) Moench.), that grow in typical habitats of the mountain, distribution of heavy metals in aerial parts and roots was investigated too.For all samples from post-fire area cation exchange capacity and soil organic matter content are increased while rH is decreased. Fire caused slightly increased bioavailability of the observed metals but more significant rise happened in metal amounts bound to oxides and organics. The plants showed variable behavior. T. chamaedrys collected on the post-fire area contained elevated concentrations of all analyzed metals. A. alpinus showed higher phytoaccumulation for Zn and Cd, while the other two plant species for Pb and Cd in the post-fire areas. 相似文献
145.
Lakshmi Raghu Nagendra Prasad Rentachintala Muni Reddy Mutukuru Gangireddy Pranab Kumar Mohapatra 《环境质量管理》2023,32(3):111-121
In the present study, Amaravati, the proposed city of India is considered to assess the impacts of urbanization on water quality of the Krishna River in the vicinity. Long-term surface water quality data of various parameters of Krishna River are obtained from Central Water Commission (CWC). Trends of various parameters are analyzed using a modified version of Mann-Kendall (M-K) test; bootstrapped M-K trend test with optional bias corrected pre-whitening and R programming are used affecting water quality prior to and at the commencement of urbanization. During the onset of urbanization, minimum BOD is decreased from 0.49 to 0.2 mg/L, while the maximum BOD is increased by 67.7%. Dissolved oxygen's (DO) minimum value is decreased by 29.33% while maximum DO value is decreased by 4.47% at the beginning of urbanization. During the process of urbanization, total coliform's minimum count is increased to 330 from 2 MPN/100 ml while the maximum count of total coliforms is increased to 16,000 from 2400 MPN/100 ml. Faecal coilform's minimum count is increased from 2 to 80 MPN/100 ml while maximum count is increased to 16,000 from 800 MPN/100 ml during urbanization. It is found that due to urbanization, pH, DO values exceed the allowable limit. 相似文献
146.
Large, landscape-scale national monuments have long been controversial. It has been claimed that large monuments harm local economies by restricting growth of the grazing, timber, mining, and energy industries. Others have asserted that large monuments aid economic growth by reducing reliance on volatile commodity markets and fostering tourism growth. In this study, we use a synthetic control approach to measure the average causal effect of nine national monument designations on county-level per capita income. We find no evidence that monument designation affected per capita income in any of 20 counties hosting nine large (>50,000 acres) national monuments established under the Antiquities Act (six monuments) or by legislative action (three monuments). The broad economic claims of both advocates and critics of large national monuments have little empirical support. The absence of a designation effect for large national monuments is likely due to the attributes of federal land and the legal constraints under which it is managed. 相似文献
147.
Major cities in China and many other fast-growing economies are expanding their subway systems in order to address worsening air pollution and traffic congestion. This paper quantifies the impact of subway expansion on air quality by leveraging fine-scale air quality data and the rapid build-out of 14 new subway lines and 252 stations in Beijing from 2008 to 2016. Our main empirical framework examines how the density of the subway network affects air quality across different locations in the city during this period. To address the potential endogenous location of subway stations, we construct an instrument based on historical subway planning, long before air pollution and traffic congestion were of concern. Our analysis shows that an increase in subway density by one standard deviation improves air quality by two percent and the result is robust to a variety of alternative specifications including the distance-based difference-in-differences method. The total discounted health benefit during a 20-year period from reduced mortality and morbidity as a result of 14 new subway lines amounts to $1.0–3.1 billion, or only 1.4–4.4 percent of the total construction and operating cost. 相似文献
148.
以铬菁R为显色剂、氯代十六烷基吡啶和曲力通X-100为双组分增敏剂,建立了测定水中Al3+的铬菁R显色分光光度法,并对实验条件进行了优化。实验结果表明:双组分增敏剂的引入,在提高测定灵敏度的同时也增强了测定选择性;在Al3+质量浓度为0.030~0.32 mg/L的范围内,校准曲线的线性关系良好,方法检出限为0.10 mg/L;精密度测定(n=6)的相对标准偏差小于3%,实际样品测定的加标回收率为97.8%~101%。本方法降低了试剂空白值,具有灵敏度高、精密度好、测定范围宽的特点,技术指标优于所有现行国家标准测定水中Al3+的分光光度法。 相似文献
149.
Yuqing Shen Jianyun Zhang Jingqian Xie 《Journal of environmental science and health. Part. B》2020,55(2):91-102
AbstractInformation regarding the enantioselective endocrine disruption of chiral herbicides is scarce. This study assessed the disrupting effects of eight typical chiral herbicides on corticosteroids (including glucocorticoids and mineralocorticoids). Enantioselectivity of eight chiral herbicides were evaluated for their agonistic/antagonistic effects on glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) with CHOK1 cell line using reporter gene assay. Their influence on the production of corticosteroids were further investigated in H295R cell line using enzyme-linked immunosorbent assay (ELISA). None of the racemates or enantiomers of eight chiral herbicides exhibited GR or MR agonistic activity at non-cytotoxic concentrations. However, rac-propisochlor and S-imazamox antagonized cortisol-induced transactivation of GR by 21.79% and 38.73% at the concentration of 1.0?×?10?7 M and 1.0?×?10?6 M, respectively, and R-napropamide remarkably attenuated aldosterone-induced MR transactivation by 68.78% at 1.0?×?10?6 M. The secretion of cortisol was significantly restrained after treated with 1.0?×?10?6 M rac-propisochlor and rac-/R-napropamide at the concentration of 1.0?×?10?6 M by 26.49%, 30.10% and 35.27%, respectively, while this glucocorticoid was remarkably induced by 1.0?×?10?5 M rac-diclofop-methyl and its two enantiomers at the concentration of 1.0?×?10?5 M by 75.60%, 100.1% and 68.78%, respectively. Exposure to rac-propisochlor (1.0?×?10?6 M), S-diclofop-methyl (1.0?×?10?5 M) or rac-/S-/R- acetochlor (1.0?×?10?6 M) and rac-/S-/R-lactofen (1.0?×?10?6 M) inhibited the secretion of aldosterone by approximately 40%. Our findings suggested that chiral herbicides disrupted corticosteroid homeostasis in an enantioselective way. Therefore, more comprehensive screening is required to better understand the ecological and health risks of chiral pesticides. 相似文献
150.
Kerstin Ronneberger Maria Berrittella Francesco Bosello Richard S. J. Tol 《Environmental Modeling and Assessment》2009,14(2):149-168
In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis
Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication
for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on
the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland
patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness
and potentials of the coupled system. Reference simulations with the uncoupled models emphasise the impact and relevance of
the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.
相似文献
Francesco BoselloEmail: Email: |