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171.
Protected areas present a global heritage. Assessing conservation achievements in protected areas is of crucial importance with respect to the on-time delivery of international biodiversity conservation targets. However, monitoring data from publicly accessible databases for comparative studies of conservation achievements in the protected areas of the world are very scarce, if not non-existent. At first glance this is surprising because, with regards to protected areas, at least according to well established protected area management guidelines and widely accepted public mandates, a great deal of monitoring work and data gathering is to be conducted. This would imply that data on changes of biodiversity in protected areas could be expected to exist, and the constant progress in information technologies and Web tools engenders hope that some of it might even be available online for the global public. This review article presents the results of an extensive online search and review of existing monitoring data from freely accessible online databases for its use in an assessment of conservation achievements in a larger sample of protected areas. Results show two contrary sides to the status quo of accessible data from the World Wide Web for conservation science: data overkill and data scarcity with poor metadata provision. While ever more research is, in fact, based on open-access online data, such as extrapolations of species ranges used in conservation management and planning, it remains almost impossible to obtain a basic set of information for an assessment of conservation achievements within a larger number of protected areas. This awareness has triggered a detailed discussion about the discrepancies in sharing data at the level of protected areas; mismatching relationships between expected activities in protected areas and the capacity for delivering these requirements are certainly among the main challenges. In addition, the fear of data misuse potentially resulting in harm for nature, careers, and competencies still seems to be a critical barrier strictly controlling the willingness to share data. Various initiatives aimed at tackling technical and cultural obstacles are introduced and discussed to reach the goal of a modern resource management based on adaptive management using digital opportunities of the new millennium for a sustainable global village. 相似文献
172.
我国洗衣粉消费形成的COD总量测 总被引:1,自引:0,他引:1
根据水质COD重铬酸钾法,实测了市场上5种常见品牌洗衣粉的COD负荷值,得到其平均值为0.328(w/w)(绝干洗衣粉)。由我国使用量计算得到2005年洗衣粉形成的COD总量为88.87×10^4t,这相当于当年全国工业和生活COD排放总量的6.3%,全国生活COD排放总量的10.3%,2005年我国洗衣粉消费过程COD产污系数为1.86g/(d·人),需要对洗衣粉消费形成的COD总量水平予以必要的关注。 相似文献
173.
本文介绍了使用超声波和磁粉探伤技术对某大吨位铸造用桥式起重机主起升系统吊具金属结构母材及其焊缝探伤检验的一些情况,重点阐述了探伤检验部位确定的方法和依据。 相似文献
174.
Gurnell AM Morrissey IP Boitsidis AJ Bark T Clifford NJ Petts GE Thompson K 《Environmental management》2006,38(4):580-596
A conceptual model of the morphological development of the riparian margins of newly cut river channels is presented, suggesting
early feedbacks between vegetation growth and bank form. To test the model, observations of long and cross profiles, bank
sediment and seed deposition, and bank vegetation development were collected over the first 2 years of river flows through
a reach of the River Cole, West Midlands, UK. The newly created channel had a sinuous planform and varying asymmetric trapezoidal
cross section in sympathy with the planform. No imposed bedforms or bank reseeding were included in the design. Over the 2
years, development of bedforms was rapid, with bed sediment sorting and bank profile adjustment occurring more steadily and
progressively. Six classes of bank profile were identified by the end of the study period, illustrating close associations
with sediment aggradation, vegetation colonization, and growth patterns. Vegetation colonization of the banks was seeded predominantly
from local sources during the summer and from hydrochory (transport by the river) during the winter. Colonizing vegetation
on the riverbanks appeared to act as a significant propagule source by the second summer and as an increasingly important
roughness element, trapping both propagules and sediment, within the second year and providing early feedback into bank evolution.
As a result, the time required for riparian margin development in the conceptual model was found to be considerably longer
than observed in the study river. In addition, the role of surface wash/bank failure in modifying the bank profile and transporting
seeds onto the upper bank face during the first year of bank development was found to be important in initiating rapid bank
vegetation colonization and surface stabilization. This set of processes had not been incorporated in the initial conceptual
model. In relation to channel restoration, this research illustrates that in small temperate rivers of modest energy the provision
of an initial, sinuous corridor is sufficient to induce rapid development of fluvial features and vegetation cover without
the need to construct bed forms or to seed the banks. 相似文献
175.
176.
J. M. Castillo C. J. Luque E. M. Castellanos M. E. Figueroa 《Journal of Coastal Conservation》2000,6(1):89-96
This study reports on the quantification of horizontal erosion by undermining of slopes in the atlantic mesotidal salt marshes
of Odiel, SW Spain, and analyses its causes and consequences. Horizontal erosion has produced considerable losses of salt
marsh area, including zones of mature salt marsh. Human pressure, such as from water-borne traffic or the exploitation of
the slopes for the capture of bait, increases the natural erosion processes. The role of vegetation in protecting the slopes
against erosion is studied. Channel banks covered with plants, many of which belong to species with long-living, above-ground
creeping stems, were less eroded than those without vegetation cover. The enormous volume of sediments moved (ca. 7000m3 in one year) could contribute to the silting-up of the navigable channels of the estuary, so that continual dredging is necessary
to allow access to shipping. These sediments are highly contaminated, and dredging exposes them more directly to the trophic
network of the estuary. There is a considerable loss of natural resources. Finally, the integrated management of this coastal
ecosystem is discussed. 相似文献
177.
B. Bowonder 《Resources Policy》1983,9(3):206-224
The problem of forest depletion needs to be given serious consideration in developing countries due to the preponderance of exploitative factors over regenerative factors. In most of the developing countries there is over-exploitation of forest resources and, unless an integrated forest resource policy is formulated and implemented, forest resources of the Third World will become the greatest ‘tragedy of the commons’. 相似文献
178.
江汉湖沼资源的开发与保护 总被引:1,自引:0,他引:1
张家玉|冯慧芳 《长江流域资源与环境》1992,1(1):7-48
湖沼是重要的自然资源,是开发水体生态农业与发展轻化工业原材料的生产基地。保护湖沼资源不但能调控环境,且可成为天然水生或沼生生物的基因库。对江汉湖沼资源的保护与合理开发利用,既能收到巨大的经济效益,又可保护湖沼生态环境和发挥其生态经济效益。 相似文献
179.
The Total Maximum Daily Load (TMDL) for ammonia and biochemical oxygen demand for the Pee Dee, Waccamaw, and Atlantic Intracoastal Waterway system near Myrtle Beach, South Carolina, mandated a 60-percent reduction in point-source loading. For waters with a naturally low background dissolved-oxygen concentrations, South Carolina anti-degradation rules in the water-quality regulations allows a permitted discharger a reduction of dissolved oxygen of 0.1 milligrams per liter (mg/L). This is known as the 0.1 rule. Permitted dischargers within this region of the State operate under the 0.1 rule and cannot cause a cumulative impact greater than 0.1 mg/L on dissolved-oxygen concentrations. For municipal water-reclamation facilities to serve the rapidly growing resort and retirement community near Myrtle Beach, a variable loading scheme was developed to allow dischargers to utilize increased assimilative capacity during higher streamflow conditions while still meeting the requirements of a recently established TMDL.As part of the TMDL development, an extensive real-time data-collection network was established in the lower Waccamaw and Pee Dee River watershed where continuous measurements of streamflow, water level, dissolved oxygen, temperature, and specific conductance are collected. In addition, the dynamic BRANCH/BLTM models were calibrated and validated to simulate the water quality and tidal dynamics of the system. The assimilative capacities for various streamflows were also analyzed.The variable-loading scheme established total loadings for three streamflow levels. Model simulations show the results from the additional loading to be less than a 0.1mg/L reduction in dissolved oxygen. As part of the loading scheme, the real-time network was redesigned to monitor streamflow entering the study area and water-quality conditions in the location of dissolved-oxygen sags. The study reveals how one group of permit holders used a variable-loading scheme to implement restrictive permit limits without experiencing prohibitive capital expenditures or initiating a lengthy appeals process. 相似文献
180.
基于地基遥感资料的厦门市污染边界层特征分析 总被引:2,自引:0,他引:2
城市大气边界层是影响城市环境气象的重要研究对象,本研究利用新型地基遥感数据针对城市颗粒物污染过程开展边界层特征分析,旨在利用风廓线雷达和微波辐射计等高时空分辨率的遥感数据探讨边界层内大气运动、温湿条件的变化与近地面污染累积的关系.结果表明:厦门地区颗粒物污染过程中,边界层内弱风层厚度较地面风速而言更能够代表边界层内扩散条件的变化,可以更好地表征和预测近地面污染的变化;在局地累积的污染过程中,边界层内存在较厚的弱风层,同时2 km以下的风场有明显的风向转变特征,导致边界层内不存在有效的传输和扩散,另外,污染时边界层垂直温差可以在一定程度上反映干季的垂直扩散条件,0~3 km温差与PM_(2.5)浓度有着密切的联系;冷空气过程有将上游污染物向本地区输送的可能,城市边界层在东北大风的条件下伴随着显著的垂直下沉运动,有利于上空污染向下扩散.多源地基遥感数据联合分析能够进一步解释城市边界层内气象条件对于城市大气污染变化的影响,集合各设备的探测优势开展城市宜居和污染气象条件研究具有较高的科学性和可行性. 相似文献