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721.
Abstract

Studying the process and characteristics of urban land change in different phases of urbanization and different economic development is much important for understanding urban land change and management at a macro level. Taking the example of Jiangsu Province, the present paper studied the correlation between urban land change process and socioeconomic development from 1981 to 2003 on the basis of statistical data. The results showed the following three aspects. First, urban land area has changed periodically and the research duration can be divided into two periods: from 1981 to 1994 and from 1995 to 2003. In each period, the changing trend is the same, i.e. slow at first and then quick. Studying from the comprehensive change status, the characteristic of fluctuant change is significant with three acute change pinnacles in 1988, 1991 and 2002 which were corresponded to turning point years of economic development phases of Jiangsu Province respectively. Second, the synchronization between urban land change and urbanization level change is not strict. With the evolution of urbanization phases, the change pace of urbanization level increased remarkably, but urban land change rate did not increase significantly accordingly. Third, the area of urban land has exponentially increased with the increase of per capita GDP. In different economic development levels classified by per capital GDP, land resource cost for economic development is different, respectively 29.01 hm2, 26.34 hm2, 26.22 hm2, and 11.14 hm2 for the increase of 100 million RMB GDP when the per capita GDP is under 1000, 1000–2000, 2000–5000 and over 5000 RMB.  相似文献   
722.
Objective: This study aimed to describe the trends of motorization and mortality rates from road traffic accidents and examine their associations in a rapidly urbanizing city in China, Shenzhen.

Methods: Using data from the Shenzhen Deaths Registry between 1994 and 2013, we calculated the annual mortality rates of road traffic accidents, in addition to the age- and sex-specific mortality rates and their annual percentage changes (APCs) for the period of 2000–2013. We also examined the associations between mortality rate of road traffic accidents and traffic growth with Spearman's rank correlation analysis and a log-linear model derived from Smeed's law.

Results: A total of 20,196 deaths due to road traffic accidents, including 14,391 (71.3%) male deaths and 5,805 (28.7%) female deaths, were recorded in Shenzhen from 1994 to 2013. The annual mortality rates in terms of deaths per population and deaths per vehicle changed in similar patterns, demonstrating an increase since 1994 and peaking in 1997, followed by a steady decrease thereafter. The decrease in mortality was faster in individuals aged 20 year or older compared to those younger than 20 years. The mortality rates in term of deaths per population were positively correlated with the total number of vehicles per kilometer of road but negatively correlated with the motorization rate in term of vehicles per population. The estimated model for deaths due to road traffic accidents in relation to the total population and the number of registered vehicles was ln (deaths/10,000 vehicles) = ?1.902 × ln (vehicles/population) ? 1.961. The coefficient was statistically significant (P < .001) and the coefficient of determination was 0.966, indicating a good model fit.

Conclusions: We described a generally decreasing trend in the mortality rates of road traffic accidents in a rapidly urbanizing Chinese city based observations in the 20-year period from 1994 to 2013. The decreased mortality rate may be explained by the expansion of road network construction, improved road safety regulations and management, as well as more accessible ambulance services in recent years. Nevertheless, road traffic accidents remain a universal problem of great public health concern in the whole population.  相似文献   
723.
To examine the status and risk of heavy metal pollution in urban lakes, in China, the distribution of several heavy metals (e.g., Cr, Cu, Ni, Pb, Zn) in the sediment of Moshui Lake, Hangyang District, Wuhan City, was characterized. The process of rapid urbanization and industrialization of the district was also studied to find out its relationship with the metal accumulation profile in the sediment. It was found that the total concentration of heavy metals in the sediment was higher than the severe e ect level (SEL), at all sampling sites, except those in the riparian zone. The Cr and Cu maximum concentrations were 1,780 and 1,250 mg/kg, approximately 16 and 11 times as much as the SEL values, and they appeared as deep as 32 cm in one sample. The carbonate and exchangeable fractions of Zn were more than 50% of the total Zn content, resulting in very high risk according to the Risk Assessment Code (RAC). For Cu and Ni, a medium RAC value was found for carbonate and exchangeable fractions of 11%–20%. As sensitive indicators of contaminants in aquatic systems, heavy metals in the sediment reflect the outcome of regional urbanization, industrialization, and environmental management. With rapid urbanization, sedimentary Pb and Zn concentrations increased. The experimental results showed that high sedimentary heavy metal concentrations had resulted from rapid urbanization and industrialization, which would absolutely lead to substantial aquatic environmental decline in urban lakes.  相似文献   
724.
为了综合测度新型城镇化发展水平,在分析新型城镇化内涵的基础上,运用熵值法构建了新型城镇化的三级评价指标体系,并采用2005-2012年数据对河南省新型城镇化综合发展程度、发展度、协调度和持续度进行了定量评价.结果表明,河南省新型城镇化发展态势良好,综合发展程度和发展度一直保持稳定的上升趋势;新型城镇化协调度总体上呈增长趋势,局部存在一定波动;持续度在研究期间内呈稳定态势.  相似文献   
725.
以内蒙古自治区为例,利用2000-2012年的统计数据,采用主成分分析法分别对城镇化与生态环境两个子系统的综合水平进行测度.在此基础上,构建了城镇化与生态环境的协调发展模型,对内蒙古自治区不同年份城镇化与生态环境的协调发展度进行了动态分析.研究结果表明,2000-2012年内蒙古城镇化综合发展水平呈逐年上升趋势,生态环境综合水平呈波动增长的发展趋势,城镇化与生态环境协调发展演化周期经历了失调衰退、基本协调发展、协调发展3个阶段.  相似文献   
726.
通过构建城市化效率和生态效率的指标体系,利用DEA模型、相对发展度模型和耦合度模型分析了2003-2012年中国30个省的城市化效率与生态效率相对发展水平和耦合水平.结果表明:①10年间耦合度整体上呈现平缓下降—缓慢上升的趋势,耦合水平较高;②中国城市化效率与生态效率耦合度的空间分布格局发生明显变化,三级梯度的分布空间规律逐渐被打破,呈现出交错分布的格局;③在城市化不断推进的过程中,由于经济水平、产业结构、生态环境等方面存在差异,各省份需要合理地平衡城市化效率与生态效率的发展,确保城市建设和生态建设地有序进行.  相似文献   
727.
改革开放以来,我国滨海城镇化进程不断加快,呈现环湾型、陆岛型、新城型等空间模式,造成的生态效应错综复杂.新近颁布的《国家新型城镇化规划》进一步明确将沿海地区作为城镇化战略格局的重要轴线,生态效应更应得到高度关注.对此,完善生态管治是规避生态风险、应对生态问题的关键举措,要从加强滨海生态过程的链式管治、优化滨海城乡规划的综合效应、促进滨海多元主体的协同共治等方面着力推进,为我国沿海城市新型城镇化与陆海统筹战略的深入推进夯实基础.  相似文献   
728.
The hydrologic and water quality benefits of an existing engineered stormwater control measures (SCMs) network, along with the alternative stormwater control simulations, were assessed in the rapidly urbanizing Beaverdam Creek watershed located in SE U.S. Piedmont region through the use of distributed Model of Urban Stormwater Improvement Conceptualization stormwater model. When compared with predevelopment conditions, the postdevelopment watershed simulation without SCMs indicated a 2 times increase in total runoff volume, 3 times average increase in peak flow for 1.5‐3.2 cm 6‐h storm events, and 30 times, 12 times, and 3 times higher total suspended solids (TSS), total phosphorous (TP), and total nitrogen (TN) loadings, respectively. The existing SCMs network, in comparison with the postdeveloped watershed without SCMs, reduced the average peak flow rates for 1.5‐3.2 cm 6‐h storm events by 70%, lowered the annual runoff volume by 3%, and lowered TSS, TP, TN annual loads by 57, 51, and 10%, respectively. A backyard rain garden simulation resulted in minimal additional reduction in TSS (1.6%), TP (0.4%), and TN (4%). Model simulations indicate that mandatory 85% TSS and 70% TP annual load reductions in comparison with the predevelopment levels would require the diversion of runoff from at least 70% of the contributing drainage areas runoff into additional offline bioretention basins.  相似文献   
729.
城市化对周边土壤资源与环境的影响   总被引:37,自引:1,他引:37  
城市化快速发展对土壤资源产生巨大压力。因而对粮食安全与环境生态健康带来严峻挑战,作为一种非再生性自然资源,土壤的各种功能在城市化过程中强烈的人为活动影响下转化,演变和消失,那么,寻求城市化过程中土壤资源的可持续利用,在环境友好的模式下协调土壤自然生态与社会经济发展,最大限谋发挥土壤生态,生产和社会,经济功能,也是城市化快速发展的重要前提,也是最终实现可持续城市目标的基础。  相似文献   
730.
河西走廊绿洲城市化及可持续对策   总被引:10,自引:1,他引:10  
本文分析了河西走廊绿州城市化现状 ,认为经济基础薄弱、产业结构不合理、水资源匮乏、生态环境脆弱是河西走廊绿洲城市化的主要限制因素 ,指出河西绿洲加速城市化应加大产业结构调整力度 ,系统规划城市建设 ,加强水资源统一管理和节水建设 ,大力发展教育事业和提高农业产业化水平  相似文献   
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