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101.
研究全球变暖背景下藏西南高原气候及气候生产潜力时空分布,对该区农牧业发展、生态保护和可持续发展等具有重要意义。基于1901—2017年的中国气象再分析数据,利用Miami和Thornthwaite Memorial模型对近117年藏西南高原气候变化、气候生产潜力的时空分布及影响因素进行了分析。结果表明:近117年来藏西南高原年均温呈上升趋势,年均降水量呈下降趋势,并存在明显周期和突变点;温度生产潜力呈增加趋势,空间上自东南向西北递减;降水、蒸散和标准生产潜力呈减小趋势,呈现自南向北递减的空间分布特征;标准生产潜力由降水和温度共同决定,降水是主要限制因子。未来气候若持续“暖干化”变化,将导致藏西南高原气候生产潜力下降。为促进畜牧业发展和生态环境的改善,未来应进一步推进退牧还草、人工种草、舍饲养殖等工程,并选用耐寒耐旱高产草种,提高牧草产量,实现草畜平衡,以推动传统畜牧业向现代牧业转变,实现草原生态保护和可持续发展。 相似文献
102.
103.
三江源地区是我国生态安全的重要屏障,同时也是我国最主要的畜牧业生产基地之一,在保证草地资源可持续利用前提下,探究合理的人口容量对该区的生态保护建设和可持续发展具有重要意义。通过模型模拟草地理论载畜量以估算畜牧业产值,设定三种居民生活水平情景,模拟不同情景不同时期下的适度人口容量,分析人口承载力的空间差异性。结果表明:“十五”期间,三种情景下全区人口承载力呈富余状态;“十一五”和“十二五”期间在当前居民和小康水平情景的人口容量尚有结余;到“十三五”期间,三种情景下人口承载力总体均超载,但空间分布不同,在当前居民、小康和富裕生活水平情景下,分别有11个、8个和2个县的人口容量尚有结余,人口承载力超载地区主要分布于三江源地区东部。应根据现有资源分布和符合主体功能要求的方向进行调整和优化人口结构,将对该地区可持续发展战略具有重要意义。 相似文献
104.
王盈 《环境监测管理与技术》2013,25(4):61-63
对水中油类测定的新旧标准---《水质石油类和动植物油类的测定红外分光光度法》( HJ 637-2012)和《水质石油类和动植物油类的测定红外分光光度法》( GB/T 16488-1996)作比较,前者的内容中增加了总油的定义,修改了干燥剂的处理条件、样品体积的测量方法及萃取条件和萃取液脱水方式,删除了絮凝富集萃取的内容。试验证明,改进后的方法降低了检出限和空白干扰,样品体积测量更加准确。 相似文献
105.
As result of a study to control feedstuff, analyses were carried out to evaluate the contamination caused by PCDDs and PCDFs in different animal feed ingredients. Thirty two samples were selected, including ingredients of animal and mineral origin. For samples of mineral origin, some additives widely employed as binder and anticaking agents, such as bentonite, damoline, kaolin, magnesite, sepiolite and zeolite were selected. And, for ingredients of animal origin, samples of hemoglobin, animal fat, fish oil, fish meal and meat and bone meal were analyzed. The levels ranged from 0.52 to 9.08 pg WHO-TEQ/g fat for samples of animal origin, and from 0.05 to 460.59 pg WHO-TEQ/g for samples of mineral origin. The higher concentrations were observed for the kaolin samples that presented high levels of dioxin contamination. 相似文献
106.
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in some additives widely employed as binder and anti-caking agents in feedstuffs, such as kaolin, bentonite, zeolite, etc. with an special attention on sepiolite samples. Owing to their physico-chemical properties, the little information of these materials reported in the literature, the variability of PCDDs/PCDFs found in a preliminary evaluation and the absence of reference materials highlighted further research needed. Therefore, an extensive study on the analytical procedures based on the classical methods was performed with sepiolite samples. The study includes evaluation of reproducibility and repeatibility. To this end, a series of intra-day and nine inter-day analysis were made. The methodolgy was also assessed against the sample size and series of 12.5, 25, 37.5 and 50 g were analyzed. In all cases, the results confirmed good correlation with the parameters evaluated. 相似文献
107.
随着畜禽养殖业的发展,养殖废弃物的产生量逐年增加,对环境的影响日益严重,为控制和治理养殖污染物的排放进行环境影响评价成为社会普遍关注的热点。通过对养殖项目环境影响评价工作的编制依据、评价标准的介绍,并以阜康市某规模化肉牛养殖项目为例,对其运营期环境影响进行评价,并提出相应的环境保护措施,为环保部门和企业的管理提供理论依据,并为规模化养殖项目污染的预防治理提供实践经验,最大限度降低项目建设对周围环境的不利影响,推动养殖业的可持续发展。 相似文献
108.
A calibrated auction-conjoint valuation method: Valuing pork and eggs produced under differing animal welfare conditions 总被引:1,自引:0,他引:1
This paper develops a valuation method which generates consistent and systematic estimates of people's preferences for complex multi-attribute goods by inextricably linking auction bids with conjoint ratings. The advantage of the valuation approach is that it permits the estimation of people's values for many potential goods, allows one to decompose people's values for a good into its sub-components, and permits the study of preference heterogeneity without distributional assumptions. We apply the method to an important and increasingly controversial topic: animal welfare. The method is used to determine people's preferences for eggs and pork produced from different production systems. Data from experiments conducted in three diverse U.S. locations (Chicago, IL; Dallas, TX; and Wilmington, NC) indicates that people are, on average, willing to pay $0.95 more for a dozen eggs raised in an aviary, pasture system vs. a cage system, and are willing to pay $2.02 more for two-pounds of pork chops raised in a pasture system as opposed to a crate system. 相似文献
109.
Conservation planning of critical habitats for wildlife species at risk is a priority topic that requires the knowledge of how animals select and use their habitat, and how they respond to future developmental changes in their environment. This paper explores the role of a habitat-modeling methodological approach, agent-based modeling, which we advocate as a promising approach for ecological research. Agent-based models (ABMs) are capable of simultaneously distinguishing animal densities from habitat quality, can explicitly represent the environment and its dynamism, can accommodate spatial patterns of inter- and intra-species mechanisms, and can explore feedbacks and adaptations inherent in these systems. ABMs comprise autonomous, individual entities; each with dynamic, adaptive behaviors and heterogeneous characteristics that interact with each other and with their environment. These interactions result in emergent outcomes that can be used to quantitatively examine critical habitats from the individual- to population-level. ABMs can also explore how wildlife will respond to potential changes in environmental conditions, since they can readily incorporate adaptive animal-movement ecology in a changing landscape. This paper describes the necessary elements of an ABM developed specifically for understanding wildlife habitat selection, reviews the current empirical literature on ABMs in wildlife ecology and management, and evaluates the current and future roles these ABMs can play, specifically with regards to scenario planning of designated critical habitats. 相似文献
110.
Rapid growth of intensive animal industries in southeast Queensland, Australia, has led to large volumes of animal waste production,
which posses serious environmental problems in the Murray Darling Basin (MDB). This study presents a method of selecting sites
for the safe application of animal waste as fertiliser to agricultural land. A site suitability map for the Westbrook subcatchment
within the MDB was created using a geographic information system (GIS)-based weighted linear combination (WLC) model. The
factors affecting the suitability of a site for animal waste application were selected, and digital data sets derived from
up to 1:50,000 scale maps were acquired. After initial preprocessing, digital data sets were clipped to the size of the delineated
subcatchment boundary producing input factors. These input factors were weighted using the analytical hierarchy process (AHP)
that employed an objectives-oriented comparison (OOC) technique to formulate the pairwise comparison matrix. The OOC technique,
which is capable of deriving factor weight independently, formulated the weight derivation process by making it more logical
and systematic. The factor attributes were classified into multiple classes and weighted using the AHP. The effects of the
number of input factors and factor weighting on the areal extent and the degree of site suitability were examined. Due to
the presence of large nonagricultural and residential areas in the subcatchment, only 16% of the area was found suitable for
animal waste application. The areal extent resulting from this site suitability assessment was found to be dependent on the
areal constraints imposed on each input factor, while the degree of suitability was principally a function of the weight distribution
between the factors. 相似文献