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81.
Fine root dynamics (diameter < 1 mm) in mature Fagus sylvatica, with the canopies exposed to ambient or twice-ambient ozone concentrations, were investigated throughout 2004. The focus was on the seasonal timing and extent of fine root dynamics (growth, mortality) in relation to the soil environment (water content, temperature). Under ambient ozone concentrations, a significant relationship was found between fine root turnover and soil environmental changes indicating accelerated fine root turnover under favourable soil conditions. In contrast, under elevated ozone, this relationship vanished as the result of an altered temporal pattern of fine root growth. Fine root survival and turnover rate did not differ significantly between the different ozone regimes, although a delay in current-year fine root shedding was found under the elevated ozone concentrations. The data indicate that increasing tropospheric ozone levels can alter the timing of fine root turnover in mature F. sylvatica but do not affect the turnover rate.  相似文献   
82.
Considering growing population and decreasing mineral resource reserves, the issue of undermining has been and shall remain very topical. This study aims to identify the mutual connections between mined out panels of a deposit and the final manifestations on the ground surface related to deep black coal mining. On the grounds of the identified connections, the study describes a method to simplify a common evaluation of undermined areas according to building site categories. Within the study, a demarcation of the areas was conducted in two localities in Czech Republic influenced by the effects of undermining in the Upper-Silesian Basin. In the allotment of the CSM Mine, an area unsuitable for founding structures was defined from the centre of the worked out workings to the distance of 175 m from the panel's edge, for which the corresponding break angle is 78.3°. Similarly, in the allotment of the Paskov Mine, an area unsuitable for founding structures was determined to the distance of 500 m from the panel's edge, for which the corresponding break angle is 50.2°. This demarcation may be implemented prior to deposit mining being aware of several physical-mechanical parameters of rocks in the deposit's overburden. Having mined out a particular section of a deposit, it is recommended to verify the values of break angle using the method described herein. The study may be applied as a relatively fast and effective method to evaluate future land use for planning.  相似文献   
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84.
Smallholder Agroforestry Systems For Carbon Storage   总被引:3,自引:0,他引:3  
Most smallholder agroforestry systems in Southeast Asia are tree- and species-rich systems producing non-wood and wood products for both home use and market sale. Due to their high biomass, these systems contain large carbon (C) stocks. While the systems of individual farmers are of limited size, on a per area basis smallholder systems accumulate significant amounts of C, equaling the amount of C stored in some secondary forests of similar age. Their ability to simultaneously address smallholders’ livelihood needs and store large amounts of C makes smallholder systems viable project types under the Clean Development Mechanism (CDM) of the Kyoto Protocol, with its dual objective of emissions reduction and sustainable development. Smallholder systems have not developed in areas where enabling conditions do not exist. A CDM project that facilitates a minimum threshold of enabling conditions that make smallholder agroforestation possible should qualify for C credits. To secure smallholder confidence, the agroforestry systems promoted through a CDM project must be socially and economically viable independent of C payments. To assure system productivity and profitability, projects should provide farmers with technical and marketing assistance. Additionally, project sites should meet the following preconditions: areas of underutilized low-biomass landuse systems available for rehabilitation; smallholders interested in tree farming; accessible markets for tree products; supportive local governments; sufficient infrastructure; and transparent and equitable relationships between project partners. Questions of leakage and additionality should not be problematic and can be addressed through the project design, establishment of quantifiable baseline data and facilitating enabling conditions. However, smallholder-focused CDM projects would have high transaction costs. The subsequent challenge is thus to develop mechanisms that reduce the costs of: (a) making information (e.g., technology, markets) more accessible to multiple clients; (b) facilitating and enforcing smallholder agreements and (c) designing feasible monitoring systems.  相似文献   
85.
The paper is concerned with estimation of heat and power consumption in a conceptual plant to produce hydrogen from sucrose-containing or starchy biomass by fermentation. A hydrogen plant connected with a sugar factory is regarded as the basic option; the sugar factory serves as a source of sucrose-containing thick juice for the hydrogen plant, where this feedstock is processed to hydrogen. As another option, a stand-alone hydrogen plant in which starch must initially be converted to fermentable glucose solution is considered. The values of key process parameters are assumed on the basis of preliminary experimental data. For both options of the hydrogen plant, heat consumption is estimated taking heat recovery in a heat exchanger network into account. Power consumption is estimated by calculating power needed for pumping of liquid and gaseous process media.  相似文献   
86.
Marian Lydall   《Resources Policy》2009,34(3):112-120
Backward linkages refer to the various inter-firm relationships connecting an industry with its supply chain. Demand–supply interactions between producer firms and suppliers of original equipment, strategic inputs, components and specialised services have played an important role in the evolution of the South African mining sector, contributing indirectly to employment creation, new business growth and expansion, improved efficiency of mining operations, and new knowledge generation. This paper presents a case study of backward linkage development in the South African platinum group metals (PGM) industry and draws on the findings from a quantitative and qualitative analysis of the sector undertaken in 2007. A profile of the supply chain is provided and an assessment made of the strength and sustainability of existing linkages.  相似文献   
87.
Underground mining activities may potentially play a role on the initiation and reactivation of the slope movements. However, an adequate attention has not yet been paid to these problems; in this study, the possible influence of present and former mining activities on the selected set of model slope deformations in the Ostrava-Karviná Coalfield (Opliji, Repiste and Orlova Lazy District) was analysed and a methodology for their observation for application to similar conditions and influence was described. Isocatabase maps, terrain deformation parameters calculated for the point lying on the slope deformation surface, length measurement by zone extensometer and dilatometer measurement in cracks was also provided for evaluation of the underground mining impact. It was found that inclinations of both boreholes were evidence of underground mining impact, and localization of inclinometer measurement on boreholes in the active part as well as in the near vicinity was very important as an important result of this study. Analysis of underground mining activity influence on model localities in relation to performed mining operations, subsidence and other influences on the ground surface was also determined. Thus, the study will contribute to a more objective knowledge of these problems of interest for the professional public and also for the state administration to solve problems associated with the utilisation and settlement of such affected areas.  相似文献   
88.
Atmospheric particulate matter (PM) is hypothesized to increase the risk of myocardial infarction (MI). However, the epidemiological evidence is inconsistent. We identified 33 studies with more than 4 million MI patients and applied meta-analysis and meta-regression to assess the available evidence. Twenty-five studies presented the effects of the PM level on hospitalization for MI patients, while eight studies showed the effects on mortality. An increase in PM10 was associated with hospitalization and mortality in myocardial infarction patients (RR per 10 μg/m3?=?1.011, 95 % CI 1.006–1.016; RR per 10 μg/m3?=?1.008, 95 % CI 1.004–1.012, respectively); PM2.5 also increased the risk of hospitalization and mortality in MI patients (RR per 10 μg/m3?=?1.024, 95 % CI 1.007–1.041 for hospitalization and RR per 10 μg/m3?=?1.012, 95 % CI 1.010–1.015 for mortality). The results of the cumulative meta-analysis indicated that PM10 and PM2.5 were associated with myocardial infarctionwith the addition of new studies each year. In conclusion, short-term exposure to high PM10 and PM2.5 levels revealed to increase risk of hospitalization and mortality for myocardial infarction. Policy support of pollution control and individual protection was strongly recommended.  相似文献   
89.
To address the pollution that accompanies rapid industrial growth in China, a National Eco-industrial Park Demonstration Program was launched in 2000. This article provides a case study of the Tianjin Economic-Technological Development Area (TEDA). The emergence of an environmental institution in TEDA is used as a backdrop to assess how TEDA has transformed itself into one of the top three national eco-industrial parks in China. Following two years of field research, a network of 81 inter-firm symbiotic relationships formed in TEDA during the past 16 years were identified involving the utility, automobile, electronics, biotechnology, food and beverage, and resource recovery clusters. The article assesses the environmental benefits of the key symbiotic exchanges in TEDA and summarizes some unique characteristics of EIP progress in a developing country.  相似文献   
90.
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