全文获取类型
收费全文 | 215篇 |
免费 | 1篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 23篇 |
废物处理 | 3篇 |
环保管理 | 45篇 |
综合类 | 49篇 |
基础理论 | 55篇 |
污染及防治 | 21篇 |
评价与监测 | 25篇 |
社会与环境 | 4篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 5篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 8篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 17篇 |
2008年 | 23篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有228条查询结果,搜索用时 15 毫秒
111.
陈秀梅 《环境监测管理与技术》2023,(4):72-75
运用相关性分析、因子分析及多元线性回归模型对南通市2020—2021年15个监测井第Ⅲ承压层地下水的监测数据进行分析,研究深层地下水中氨氮的主要影响因素。结果表明,氨氮的主要来源是地下水沉积物中有机质的矿化及一部分工业开采引入的氮污染,地下水的还原性环境是氨氮赋存的主要成因;地下水中As、Fe及总硬度含量的同时增加也能反映氨氮含量的提高;硝态氮(NO-3-N)与NH3-N在深层地下水中是竞争关系,当地下水环境处于还原性时,更易于NH3-N的富集。降低深层地下水中氨氮的主要方法是减少有机污染物输入及还原性废水的入渗。 相似文献
112.
基于MODIS AOD遥感数据,采用多元线性回归模型对PM2.5地面监测数据进行模拟估算,同时加入降水量、相对湿度等气象因子以提高模型精度,结合GIS空间分析技术,得到2015—2016年京津冀地区空间连续的PM2.5浓度分布。结果表明:利用多元线性回归模型反演PM2.5浓度效果较好,R 2均在0.59~0.84之间。在时间上,京津冀地区PM2.5浓度呈现出夏季最低、秋季稍高、冬春两季最高的变化趋势;在空间上,2015年和2016年京津冀地区PM2.5浓度有明显的区域差异,均呈现出西北低、东南高的分布格局,大致与燕山山脉和太行山脉走向一致。 相似文献
113.
Local Responses to Inundation and De-Farming in the Reservoir Region of the Three Gorges Project (China) 总被引:1,自引:0,他引:1
Large-scale infrastructural developments in rural areas often impose significant direct and indirect impacts on environment
and people. The Three Gorges Project to dam the Yangtze River in China will create a huge reservoir, inundate farmlands and
villages, and incur large-scale resettlement. The concurrent de-farming program to reforest marginal farmlands on steep slopes
imposes additional stresses on local people. This study evaluates the ecological and economic adjustments in rural areas affected
by both projects, and explores villagers’ knowledge, attitudes, perceptions, and expectations vis-à-vis the drastic changes.
Eleven villages in Yunyang County in Sichuan Province, stratified into three zones based on topography and agriculture, were
assessed by field studies, questionnaire surveys, maps, satellite imagery, and census and government reports. Multiple regressions
identified predictors for 17 dependent variables. Spatial variations in the difficult terrain imposed zone-differentiated
agricultural constraints, ecological impacts, and human responses. The dominant farming population—mainly young adults working
as migrant laborers in cities—has adopted some nonagricultural work to supplement incomes. Expected per-capita standardized
farmland (SF) exceeded threshold SF, which surpasses existing SF. Motivations to reclaim more farmlands, de-farm marginal
lands, and become migrant laborers were explained by different multiple-regression predictors. Reduction in farmland stock
by inundation and de-farming, aggravated by unwillingness towards nonlocal resettlement, would impose ecological pressures
and stimulate demands for nonfarming incomes. Common anticipation of better future income and occupation has been subdued
by unfavorable feedbacks from early relocatees. Future environmental and landscape changes are hinged upon changing human
responses. Government policies could be informed by research findings to match economic, ecological, and social realities. 相似文献
114.
Strategic land retirement in agricultural settings has been used as one way to achieve a combination of social objectives,
which include ameliorating water quality problems and enhancing existing systems of wildlife habitat. This study uses a simulation
model operating on a virtual landscape, along with the compromise programming method, to illustrate the implications of alternative
weighting schemes for the long-term performance of the landscape toward various objectives. The analysis suggests that particular
spatial patterns may be related to how various objectives are weighted. The analysis also illustrates the inevitable trade-offs
among objectives, although it may be tempting to present retirement strategies as “win-win.” 相似文献
115.
Performance Evaluation of the SLEUTH Model in the Shenyang Metropolitan Area of Northeastern China 总被引:5,自引:0,他引:5
Xiaoqing Wu Yuanman Hu Hong S. He Rencang Bu Jeff Onsted Fengming Xi 《Environmental Modeling and Assessment》2009,14(2):221-230
Performance evaluation is crucial for the development and improvement of an urban cellular automata model, such as SLEUTH.
In this paper, we employed multiple methods for map comparison and model validation to evaluate the simulation performance
of the SLEUTH urban growth model in the Shenyang metropolitan area of China. These multiple methods included the relative
operating characteristic (ROC) curve statistic, multiple-resolutions error budget, and landscape metrics. They were used to
quantitatively examine model performance in terms of the amount and spatial location of urban development, urban spatial pattern
and prediction ability. The assessment results showed that SLEUTH performed well in the way of the quantitative simulation
of urban growth for this case study. Similar to other urban growth models, however, the simulation accuracy for spatial location
of new development at the pixel scale and urban spatial pattern still needs to be improved greatly. These inaccuracies might
be attributed to the structure and nature of SLEUTH, local urban development characteristics, and the temporal and spatial
scale of its application. Finally, many valuable suggestions had been put forward to improve simulation performance of SLEUTH
model for spatial location of urban development in the Shenyang metropolitan area. 相似文献
116.
基于多元回归理论的太湖湖泛预警模型研究 总被引:1,自引:0,他引:1
在太湖宜兴段藻源性湖泛高发区设立4个监测点,以湖泛发生的物质基础"藻类生物量"为研究对象,运用数据分析软件SPSS对监测点的藻类生物量、水质、气温等数据进行相关分析,建立了以藻密度为因变量的多元逐步回归模型。结合往年太湖藻源性湖泛发生时的气象条件等历史资料以及相关藻密度阈值的报道,构建了太湖宜兴段藻源性湖泛高发区监测预警模型系统,该模型能够基于监测点的实时水质数据和气象预报数据,对监控区域湖水在未来某时间段内发生湖泛风险的可能性进行分级预警。 相似文献
117.
Chemicals such as those used for scent marking, or visual cues such as color badges, can transmit information pertaining to
different aspects of individual, group and species recognition and attributes. Here, we show that complex acoustic cues, such
as calls also have the capacity for such information transfer. Although songs are usually attributed to birds, rock hyraxes
(Procavia capensis) engage in a rich and complex vocalizing behavior that we term ‘singing’. Previous studies on various species have shown
that a specific vocalization can closely reflect a specific attribute. Using a series of multiple regressions, we show that
a single complex vocalization by the adult male rock hyrax closely reflects numerous individual traits, possibly encoding
various types of biologically important information (multiple-messages hypothesis). Our study reveals that hyrax songs provide
accurate information regarding body weight, size and condition, social status and hormonal state of the singer. We also show
that these independent data are sent in a sequential manner, a pattern that probably allows a better partition of the messages
embedded in the song. Our results imply that animals, through complex individual vocalizations, can potentially advertise
multiple individual attributes in the same manner as that produced by chemical scent marking.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
118.
In insects, the last male to mate with a female often gains access to a disproportionate number of subsequent fertilizations.
This study examined last-male sperm precedence patterns in doubly and triply mated Tribolium castaneum females. Sperm storage processes were investigated by measuring the quantity of sperm stored within the female spermatheca
following single, double, and triple matings. Both doubly mated and triply mated females exhibited high last-male sperm precedence
for progeny produced during the first 48 h following the last mating, with females in both groups exhibiting parallel declines
in sperm precedence 1 and 2 weeks later. The number of sperm stored by females increased by 33% between singly mated and doubly
mated females, indicating that the spermatheca is filled to only two-thirds capacity following insemination by the first male.
Based on the proportion of stored sperm from first and second matings, we tested predictions about sperm precedence values
based on models of random sperm mixing. High initial last-male sperm precedence strongly supports stratification of last-male
sperm. By 1–2 weeks after double matings, sperm precedence declined to levels indistinguishable from values expected under
random mixing. These results provide insight into mechanisms of sperm storage and utilization in this species.
Received: 20 August 1997 / Accepted after revision: 24 May 1998 相似文献
119.
Adaptation as a Political Process: Adjusting to Drought and Conflict in Kenya’s Drylands 总被引:3,自引:3,他引:0
In this article, we argue that people’s adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically
political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to
climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options
and promote particular adaptation interests through forming social relations and political alliances to influence collective
decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians,
customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing
material means of survival. Second, national economic and political structures and processes affect local adaptive capacity
in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against
pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process,
not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation,
but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at
multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies
are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however,
existing power structures and conflicts of interests represent political obstacles to developing such policies. 相似文献
120.
As population densities have risen and settlements become increasingly crowded, wastewater effluent volumes have, not unexpectedly, also risen. The adverse impacts of effluent from housing estates (HEs) in suburban areas of Thailand, served by local wastewater management (WWM) systems, are of particular concern. Because of this problem, which reflects the poor performance of WWM systems, it has become increasingly important that the pivotal factors that hinder WWM improvements be identified and effective solutions be proposed and implemented. The goal of the research described in this paper was to determine the critical factors influencing WWM performance at HEs in suburban Bangkok, using multiple regression analysis. Three significant factors encompassing financial, social, institutional and general aspects were identified for each type of WWM system (community centralized and onsite). For the community centralized system, the key factors were house price, type of organization managing the HE, and the attitudes of the organization. For onsite systems, the three factors were total number of house units, direct experience with water pollution and percentage of occupied houses. These findings reflect the importance of having a WWM that employs an integrated approach rather than focusing on specific aspects in isolation from other factors. WWM performance could be improved if significant factors indicating high priority concerns were to be identified and properly applied. Addressing the priority concerns could, consequently, contribute to the development of appropriate environmental management measures, plans, and policies related to HE WWM. 相似文献