全文获取类型
收费全文 | 150篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 3篇 |
环保管理 | 12篇 |
综合类 | 45篇 |
基础理论 | 45篇 |
污染及防治 | 16篇 |
评价与监测 | 12篇 |
社会与环境 | 6篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 5篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 15篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 312 毫秒
11.
德国《民法典》确定了一般环境侵权的规则——行为责任,再以《环境责任法》确立了特殊的环境侵权的规则——设备责任。设备侵权是危险责任的一种,其构成要件有两个:设备运营对环境产生不良影响进而导致损害;人身、财产受侵害。设备责任的承担不要求设备运营人的过错。设备责任归责采用因果关系推定原则。 相似文献
12.
Arrebola JP Mutch E Rivero M Choque A Silvestre S Olea N Ocaña-Riola R Mercado LA 《Environment international》2012,38(1):54-61
The organochlorine pesticide p,p′-Dichlorodiphenyltrichloroethane (DDT) was widely used in the early 1960s-70s for vector control in tropical and subtropical areas of South America. Due to its persistence, DDT has a high potential to bioaccumulate in the food chain and living organisms and is a major public health concern, especially in South America.The main purpose of the present study was to investigate predictors of serum and adipose tissue concentrations of p,p′-DDT and its main metabolite, p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE), in an adult cohort (n = 112) from Santa Cruz de la Sierra, Bolivia, using multiple linear regression models. These models explained 29.3-47.8% of the variability in adipose tissue concentrations of p,p′-DDT and p,p′-DDE, respectively, and 32.9-47.0% of that in serum. Main exposure predictors included age, occupational class, residence, diet, smoking habit, and accumulated breastfeeding time.This is one of the few studies to explore predictors of human exposure to these chemicals using a multivariate approach in a South American population. Results show that predictors of human exposure to p,p′-DDT and p,p′-DDE in Santa Cruz de la Sierra may diverge from those found in other populations of the world, due to particular sociodemographic and lifestyle characteristics of this region. 相似文献
13.
We measured the concentration of each polychlorinated biphenyl (PCB) congener in whole blood, plasma and blood cells, and investigated the distribution of PCBs in human blood using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The PCB concentrations in plasma and whole blood in terms of lipid concentrations were almost equal, with a correlation coefficient of r = 0.972. In the blood, the ratio of PCBs in blood cells to those in plasma was generally about 1:9 and the congener distribution patterns in blood cells and plasma were similar.We performed verification of a simple mass screening method by obtaining information on the main PCB congeners for investigations on human accumulation and exposure. The total concentration of the seven PCB congeners (UNEP-7) proposed to the United Nations Environment Programme (UNEP) by Muir and Morita was about 50% of the total concentration of all PCB congeners, and UNEP-30 was about 80%. The seven main congeners in the blood (MCB-7) showed a value that was about 60%, and MCB-30 showed a value that was about 90%. Determinations with the main congeners in the blood showed a correlation of r = 0.990 or more between the main eight congeners (MCB-7 plus #74) and the total PCB concentration for all congeners. The results suggest that, although total PCB concentration can be effectively estimated from the main seven congeners, the main eight congeners would be preferable, and that the use of these congeners in the simple mass screening method would be effective for populations in areas uncontaminated by PCBs. 相似文献
14.
Nina Peuhkuri 《Behavioral ecology and sociobiology》1998,43(4-5):333-337
Individuals which deviate from the majority in groups are likely to be most vulnerable to predation. This oddity effect,
by definition, is frequency dependent, eventually fading at equal frequencies of the phenotypes in a group. It has been hypothesized
that the increased predation risk of odd individuals may play an important role in the formation of phenotypically uniform
shoals of fish. However, recent work has indicated that individuals may experience, or value, their predation hazard differently
depending on their own size in relation to that of other group members: single large fish, but not small ones, appear concerned
about their oddity in a shoal. Here I show that the apparent wariness of large fish is also expressed in a frequency-dependent
manner, closely conforming to what is predicted if the oddity effect is responsible for their behavior. Using foraging activity
of individuals as a means to evaluate their predation risk, I demonstrate with shoals comprising 12 threespine sticklebacks
(Gasterosteus aculeatus) that large fish forage least actively when in a shoal consisting of 2 large and 10 small fish. An increase in the number
of large fish to 4 among 8 small individuals clearly results in an increase in their foraging activity. However, having reached
an equal frequency with small fish in a shoal, large fish do not seem to change their foraging activity much even when their
number in a shoal increases further. In contrast, foraging activity of small sticklebacks remains fairly constant throughout
the entire range of tested shoal compositions, providing further evidence that small and large fish respond to their oddity
differently.
Received: 12 February 1998 / Accepted after revision: 7 May 1998 相似文献
15.
张雅琴 《辽宁城乡环境科技》2006,26(5):20-21
从环保审计的现状入手,分析目前企业环保审计难以向纵深发展的主要原因,提出实施企业环保审计的最佳切入点,将环保审计融入常规审计之中,并对环保审计提出配套的措施,确保环保审计适应现代化企业的发展。 相似文献
16.
Length of maternal care, i.e. the interval between successfully raised litters, is the most important factor explaining the variation in reproductive rate among brown-bear (Ursus arctos) populations. In this paper, we examine the variation in length of maternal care in radio-marked brown bears and its effect on their offspring in northern Sweden. Young stayed with their mothers for 1.4–1.5 or 2.4–2.5 (in one case 3.5) years and were weaned with body masses varying from 17 to 69 kg. The probability of yearling litters staying with their mother for a 2nd year increased with decreasing yearling body mass, and was higher for litters with two offspring than for litters with one or three to four offspring. Staying with their mothers for a 2nd year had a positive effect on mass gain in yearlings and this effect was more pronounced in litters with two than three to four offspring. Body mass of 2-year-olds was not related to age of weaning, suggesting that keeping offspring for an additional year mainly compensated for low yearling body mass. If large offspring body mass positively affects later offspring survival and reproduction, mothers may be able to optimize the length of maternal care according to the litter size and the size of their yearlings.Communicated by F. Trillmich 相似文献
17.
Simultaneous hermaphrodites are predicted to optimally divide resources between male and female function, which can result in both size-dependent mating behaviors and conflict between potential mates. Predicted strategies include size-assortative mating, conditional exchange of gametes, and mating patterns where relative size affects investment in each sexual role. This study investigated the effect of body size on the mating strategies of a hermaphroditic opisthobranch, Bulla gouldiana. Although individuals were spatially aggregated in the field with high levels of movement and size variation, there was little evidence for predictions. Laboratory experiments, however, revealed complicated effects of mass on the probability and duration of mating, as well as gender choice. Pairs were more likely to mate if they included at least one large animal, with the larger animal typically inseminating the smaller. When both individuals were large, they were more likely to each mate in both sexual roles by switching roles once. Although B. gouldiana did not usually alternate between sexual roles multiple times within mating events, paired individuals behaved similarly (neither or both mating as sperm donors) more often than expected by chance. This suggests some level of reciprocity, which is unlikely to be conditional given rates of unilateral mating. When the larger member of the mating pair inseminated the smaller, the duration of insemination increased with the size of the smaller sperm recipient. Copulations lasted longer in pairs that switched sexual roles than in those that did not switch roles. This study suggests that variation in body size can lead to size-dependent mating patterns, but only some of the patterns in B. gouldiana support theoretical predictions. We review other studies that have addressed similar issues, providing inconsistent mating patterns in sperm-storing hermaphrodites. 相似文献
18.
Katja?BargumEmail author Jacobus?J.?Boomsma Liselotte?Sundstr?m 《Behavioral ecology and sociobiology》2004,57(1):9-16
The genetic basis of morphological traits in social insects remains largely unexplored. This is even true for individual body size, a key life-history trait. In the social insects, the size of reproductive individuals affects dispersal decisions, so that small size in queens is often associated with reduced dispersal, and large size with long-range dispersal and independent colony founding. Worker size is connected to division of labour when workers specialize in certain tasks according to their size. In many species, variation in worker size has been shown to increase colony performance. In this study, we present the first evidence of an additive genetic component to queen size in ants, using maternal half sib analysis. We also compared intra-colony size variation in colonies with high (queen doubly mated) versus low (queen singly mated) genetic variability. We found a high and significant heritability (h2=0.51) for queen size in one of the two study years, but not in the other. Size variation among queens was greater in colonies headed by a doubly mated queen in one of the study years, but not in the other. This indicates that genetic factors can influence queen size, but that environmental factors may override these under some circumstances. The heritability for worker size was low (h2=0.09) and non-significant. Increased genetic diversity did not increase worker size variation in the colonies. Worker size appeared largely environmentally determined, potentially allowing colonies to adjust worker size ratios to current conditions.Communicated by J. Heinze 相似文献
19.
Although filial cannibalism (eating one’s own offspring) occurs in numerous species, including several teleost fishes, its
adaptive value is still not well understood. One often-discussed explanation is that individuals enhance their mass and body
condition by consuming part of their eggs. However, evidence for this assumption is scarce thus far. In this study, male three-spined
sticklebacks (Gasterosteus aculeatus), a species with paternal care, were allowed to care for a batch of eggs or for an empty nest under food-deprived conditions.
All brood-caring males cannibalised at least part of their eggs and thus preserved their initial mass and body condition.
Furthermore, mass as well as body condition was significant positively correlated with the number of cannibalised eggs. In
contrast, empty-nest males that had no possibility to cannibalise eggs significantly lost mass and body condition. This is,
to our knowledge, the first experimentally documented evidence that mass as well as body condition were preserved by filial
cannibalism. 相似文献
20.
In mammalian polygynous mating systems, male reproductive effort consists mainly of male–male competition and courting of
females, which entail substantial somatic costs. Males are thus expected to adjust their reproductive effort according to
their age and condition. In this study, we examined how activity budgets of male mountain goats (Oreamnos americanus), a polygynous ungulate, varied with age in a marked population over two periods: (1) summers 1995–2006 and (2) ruts 2004–2006.
We then assessed if the proportions of time spent in male–male competition and courtship behaviors were influenced by age-specific
body mass and social rank during the rut. Males spent most of their time foraging and resting during summer, and rested more
and foraged less with increasing age. During the rut, pronounced shifts in activity budgets occurred as juveniles (1–2 years)
increased time spent foraging, whereas adults (≥3 years) increased standing and time spent in social interactions at the expense
of foraging. At old age, reproductive effort either stabilized or decreased slightly, providing weak support for the ‘mating
strategy–effort’ hypothesis, predicting that courtship behaviors should peak in prime-aged males. Age-specific body mass did
not affect time spent in male–male competition, but was positively related with time spent in courtship behaviors, providing
support for the ‘individual quality’ hypothesis, predicting that males with more resources at the start of the rut should
spend more time in mating-related activities. Age-specific social rank did not affect reproductive effort. Surviving to prime
age while increasing mass each year should thus allow male ungulates to gain greater ability to court estrus females. 相似文献