全文获取类型
收费全文 | 144篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 13篇 |
环保管理 | 7篇 |
综合类 | 70篇 |
基础理论 | 40篇 |
污染及防治 | 4篇 |
评价与监测 | 10篇 |
社会与环境 | 1篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 4篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 17篇 |
2007年 | 21篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 15 毫秒
81.
环境污染源监测中的警示性分析 总被引:1,自引:0,他引:1
利用概率论有关知识,对污染源监测数据进行处理、分析、建立数字模型。依该模型可即时捕捉发生环境污染的警示性信号。 相似文献
82.
Jean-Pierre Arz Jean-Pierre Gettliffe Philippe Delattre 《International journal of occupational safety and ergonomics》2018,24(1):149-159
The effect of wearing hearing protectors on the audibility of warning signals has been evaluated for three specific railway-related jobs: track workers, train drivers and platform agents. Masked thresholds were measured in the laboratory, on railway agents with normal hearing, using warning signals and background noises typical of each job. Out of the 36 situations tested in total, statistical analyses showed that wearing earplugs improves the perception in 11 situations, deteriorates the perception in 10 situations and has no significant effect in 15 situations (as compared to no hearing protector). The deteriorations essentially concern signals which have no (or not enough) energy in the low-frequency range (f1500?Hz) when they have to be heard in background noises which dominate in the low-frequency range. To prevent the deteriorations, these signals could be modified by adding some energy in the low-frequency range (f1500?Hz). 相似文献
83.
为探究组合煤岩力学性质与声-电荷信号关系,选用新邱矿区煤样和砂岩制备组合煤岩试样,采用物理实验和数值实验相结合的方法,开展不同岩煤高度比的组合煤岩试样受载破坏声发射与电荷感应监测试验,得到了组合煤岩力学性质、声-电荷信号规律及其相互关系。结果表明:组合煤岩试样中的岩石高度提高会提升其整体强度,其破坏脆性特征显著,冲击倾向性增强,弹性阶段的声发射信号提前,声发射能量累积量增加,峰后声发射能量变化率及电荷变化率增大;组合煤岩峰后产生连续声发射信号和电荷信号,强冲击和中等冲击组合煤岩破坏时声发射能量变化率分别为0.336和0.047 J/s,电荷变化率分别为204.88和24.52 pC/s。声发射信号与电荷信号可以在一定程度上反应组合煤岩应力状态并预测失稳破坏,为通过信号监测煤体冲击地压灾害发生提供依据。 相似文献
84.
豫东黄河故道湿地鸟类自然保护区现状调查及生态保护规划 总被引:4,自引:0,他引:4
对豫东黄河故道湿地鸟类自然保护区现状进行了调查,并提出了生态保护规划。 相似文献
85.
Ross A. Sutherland Filip M. G. Tack Christina A. Tolosa Marc G. Verloo 《Environmental monitoring and assessment》2001,71(3):221-242
Washoff of road deposited sediment into storm drainsystems is one of the major contributors to nonpoint sourcepollution in urban fluvial networks. These sediments contain avariety of potentially toxic organic and inorganic contaminants.Road sediment from 13 locations in an urban (non-industrialized)drainage basin, and soil from 10 background (control) locationswere collected to assess total and labile fractions of Al, Co,Cu, Fe, Mn, Ni, Pb and Zn. Four digestions, of varying strength,were used to assess contaminant levels, these included: a totalfour-acid digestion, a microwave-assisted digestion withconcentrated nitric acid (USEPA Method 3051), a 0.5 M `cold' HCl,and a 0.05 M EDTA (pH 7). Road sediment data indicate that Al,Co, Fe, Mn and Ni were primarily lithogenic in origin, while Cu,Pb and Zn showed very significant anthropogenic signals, mostprobably from vehicle-related sources. Median Pb concentrationenrichment ratios for the EDTA extraction were about 42,indicating an extreme anthropogenic signal. The weak extractants(HCl and EDTA) are considered in this study to be superior intheir ability to characterize the degree of anthropogeniccontamination and should be utilized more widely in environmentalcontaminant studies. 相似文献
86.
87.
Gainutdinov M. Kh. Yargunov V. G. Kalinnikova T. B. Gainutdinov T. M. Varlamov V. E. 《Russian Journal of Ecology》2000,31(6):444-446
Russian Journal of Ecology - 相似文献
88.
In monogamous species, females often choose between males according to the quality of the territories they defend, but the
extent to which females themselves contribute to territory defence is frequently underestimated. Here we test for differences
in male and female roles during paired scent-marking bouts, a key component of territorial defence, in a monogamous antelope.
In two populations (Kenya, Zimbabwe) of klipspringer, Oreotragus oreotragus, both males and females usually scent-marked at the same site, but there were significant differences between sexes in terms
of investment within bouts. Females initiated most bouts, thus dictating the marking strategy of the pair. Males initiated
relatively few bouts, but deposited more scent marks per bout than females and were usually the last to scent-mark before
leaving the site; they marked on the same branches as the female and thus overmarked her scent. Both sexes deposited more
marks during paired than solo visits. Immediately preceding and following scent-marking bouts, males approached females and
females left males more often than expected. Female scent-marking rates were higher when they were receptive than at other
times, and this increase was matched by elevated marking rates of males. Females may increase marking rates when they are
receptive in order to test the quality of their mate or to incite male competition. However, these ideas are unlikely to explain
female scent-marking behaviour outside the mating season, which appears to be related primarily to territorial defence. We
suggest that these differences in investment in scent-marking bouts are consistent with predictions that females may be autonomously
territorial and that overmarking of female scent by males is a form of mate-guarding.
Received: 17 November 1999 / Received in revised form: 24 February 2000 / Accepted: 13 March 2000 相似文献
89.
A methodology of characterizing status and trend of land changes in oases: a case study of Sangong River watershed, Xinjiang, China 总被引:11,自引:0,他引:11
Land change is often studied with Markov models to develop a probability transition matrix. The existing methods dependent on such matrixes cannot effectively characterize some important aspects associated with land change such as status, direction, trend and regional variations. This study presents mathematical models to quantify these elements, defining unbalanced, quasi-balanced and balanced status, one- and two-way transitions and the rising or falling trends. Using these models and remote-sensing imageries, the landscape was studied for a case area, the oasis of Sangong River in Xinjiang, Northwest China where typical arid conditions prevail. Land expansion and contraction among various land types and for the entire oasis were analyzed for the periods of 1978-1987, 1978-1998 and 1987-1998. The changes were closely related to a strong economic growth after the land-reform campaign and adoption of the market economy in China in the 1980s to early 1990s, a process not strictly Markovian that requires stationarity and randomness. Information on land-change status and trend is important for a better understanding of the underlying driving processes but also for land-use planning and decision-making. 相似文献
90.