全文获取类型
收费全文 | 129篇 |
免费 | 1篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 8篇 |
环保管理 | 14篇 |
综合类 | 20篇 |
基础理论 | 33篇 |
污染及防治 | 21篇 |
评价与监测 | 7篇 |
社会与环境 | 6篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 2篇 |
2021年 | 2篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 10篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 9篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1964年 | 1篇 |
1960年 | 1篇 |
1958年 | 1篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1954年 | 1篇 |
1950年 | 1篇 |
1921年 | 1篇 |
1920年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 15 毫秒
121.
122.
123.
Carsten K. W. De Dreu Arne Evers Bianca Beersma Esther S. Kluwer Aukje Nauta 《组织行为杂志》2001,22(6):645-668
Conflict management influences individual wellbeing, group performance and organizational effectiveness. This research examined the psychometric qualities of two versions of the newly developed test for conflict handling. The lean version (Study 1 and 2) included problem solving, forcing, yielding and avoiding as distinct conflict management strategies, and the expanded version (Study 3) also included compromising. A negotiation study (Study 1) showed substantial convergence between self‐reports, opponent‐reports and observer rated behavior for problem solving, forcing and yielding, but not for avoiding. In Study 2 and Study 3 the psychometric properties were examined of the lean and the expanded version, respectively. Confirmatory factor analyses revealed good to excellent psychometric qualities of both versions of the scale. We conclude that the scale is a parsimonious, flexible and valid instrument to assess conflict management strategies at work. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
124.
Bushcricket males of Poecilimon zimmeri transfer large and protein-rich spermatophores during mating, which females directly ingest. There is correlational evidence
that heavier males transfer larger nuptial gifts. In no-choice mating trials, females mated randomly with respect to male’s
body weight. In contrast, in two-choice mating trials, female bushcrickets exhibit clear choice for the heavier male. This
heavier male advantage was also found in pre-mating choice during phonotaxis. With manipulated mute males, females mated at
random with regard to body weight of the competitors. The number of physical encounters between a female and males was low
in all tests with a single male (no choice) and greater in choice-tests with two competing males. The latencies to mate also
differed significantly between treatments. The time mating pairs spent in precopula was short in experiments where the males
could hear rivals and significantly longer in all other tests using either a single male or mute males. Thus, acoustic signalling
in male bushcrickets seems to signal male body weight. A preference for heavier males may reflect a female’s preference for
a larger spermatophore and therefore a greater direct benefit. 相似文献
125.
Habitat structure affects intraguild predation 总被引:4,自引:0,他引:4
Intraguild predation is thought to be ubiquitous in natural food webs. Yet, theory on intraguild predation predicts the intraguild prey to persist only under limited conditions. This gap between theory and empirical observations needs scrutiny. One reason might be that theory has focused on equilibrium dynamics and a limited set of species (usually three) that interact in well-mixed populations in unstructured habitats, and these assumptions will often not hold in natural systems. In this review, we focus on the effects of habitat structure on intraguild predation. Habitat structure could reduce encounter rates between predators and prey and could create refuges for prey. In both cases, habitat structure could reduce the strength of intraguild interactions, thereby facilitating species coexistence. A meta-analysis of studies on manipulation of habitat structure shows that intraguild prey indeed suffer less from intraguild predation in structured habitats. This was further confirmed by a meta-analysis in which studies on intraguild predation were classified according to habitat structure. Intraguild predation reduced densities of the intraguild prey significantly more in habitats with little structure than in habitats rich in structure. The effect of intraguild predation on the shared prey was negative, and not significantly affected by habitat structure. We conclude that habitat structure may increase persistence of the intraguild prey by decreasing the strength of the interaction between intraguild predator and intraguild prey. 相似文献
126.
The composition of benthic invertebrates was investigated in three Norwegian alpine watersheds during the period 1991–1997. The watersheds represented an environmental gradient in chemical factors. The Kvenna watershed was relatively well buffered, Lake Øvre Neådalsvatn was poorly buffered, but receives low inputs of atmospheric pollution while Lake Stavsvatn has low buffering capacity and receives larger inputs of acidifying components. Qualitative samples were taken in the inlet rivers, lake littoral zone, lake outlet and in the outlet rivers of the lakes for analyses of species composition. In Ø. Neådalsvatn the water chemical data showed strong seasonal variations with waters of low ionic content during snowmelt and summer, while increased ion concentrations build up during winter. The time of ice break and/or water temperature rise during the growing season affected the life cycle of Siphlonurus lacustris and Parameletus chelifer. Even small changes in pH or ANC seemed to have a strong effect on Baetis rhodani. In the Kvenna watershed eight very sensitive species were found at sites with pH 6.5, Ca 1.2 mg L-1 and LAl < 10 eq L-1. Only two highly sensitive species, B. rhodani and Capnia sp. were recorded when pH was 6, concentration of calcium 0.8 mg L-1 and low labile aluminium < 10 eq L-1. None of the highly sensitive species occurred in Stavsvatn, a formerly acidified area, where LAl concentrations ranged between 25–40 eq L-1. Low ionic content and elevated concentrations of labile aluminium are suggested to exclude sensitive invertebrates in alpine lakes. Synergistic effects of dilute water and harsh climate are assumed to increase sensitivity of invertebrates to acid water. Global warming will result in higher precipitation and more snow in the west Norwegian alpine area. This will shorten the growing season, increase the amount of dilute water and consequently threaten invertebrate species living close to their tolerance limits. 相似文献
127.
William A. Searcy Dag Eriksson Arne Lundberg 《Behavioral ecology and sociobiology》1991,29(3):167-175
Summary One explanation for polygyny in pied flycatchers (Ficedula hypoleuca) is the deception hypothesis, which proposes that females mate with already-mated males only because they are unaware that such males already have a mate on another territory. Recently this hypothesis has been criticized on the grounds that already-mated and unmated males differ sufficiently in their behavior that human observers can discriminate between the two classes fairly easily. Here we test whether male pied flycatchers change their behavior when visited by a female so as to make this discrimination more difficult. In our experiments we presented a caged female near the nestbox of an advertising male, in order to mimic the situation in which a female investigates the male and his nest site. During control periods, when only an empty cage was presented, we found that already-mated males were present on their secondary territories significantly less and sang significantly less than unmated males on their primary territories, confirming the earlier results. When we presented the stimulus female, all behaviors we measured changed significantly relative to control periods for both mated and unmated males: both classes of males increased the time spent on the territory, decreased singing rates, and increased various courtship behaviors. During the experimental periods there were no significant differences between mated and unmated males on any of the behavioral measures. Discriminant analysis was more successful in classifying males as to mating status using data from the control periods (without female) than using data from the experimental periods (with female). We conclude that when a female is present male pied flycatchers change their behavior in ways that make it more difficult to discriminate mated from unmated males.Offprint requests to: W.A. Searcy 相似文献
128.
Sexual selection in a monomorphic lek-breeding bird: correlates of male mating success in the great snipe Gallinago media 总被引:2,自引:0,他引:2
Summary In the lek-breeding great snipe, male morphology, behaviour, and territory features were recorded for individually marked birds on two adjacent leks. Partial correlation sshowed that male mating success, expressed as the number of female solicitations and copulations, was negatively correlated with the distance of a display territory to the lek center and positively correlated with the number of displays per unit time given by a male. No other variables were directly correlated with male matin success. Thus, central males obtain more matings than peripheral males and successful males display more per unit time than do less successful males, independently of position on the lek. Central males were found to be older than peripheral ones and were present more often on the lek. Furthermore, central males had a larger number of white tail feathers, which are usea as visual signals in the displays, but this may be explained by the fact that these males were older. It is suggested that male great snipe are subject to sexual selection mainly in behavioural and vocal cues and that this may explain the absence of size and plumage dimorphism in this species. 相似文献
129.
Arne Stahl 《Die Naturwissenschaften》1996,83(10):459-466
130.
Coevolution is defined as specialized relationships between species that lead to a reciprocal evolutionary change. A particularly
suitable model system for studying coevolution is the interactions between obligate avian brood parasites and their hosts.
The common cuckoo (Cuculus canorus, hereafter cuckoo) is a well-known brood parasite, which utilizes a range of smaller passerines as hosts. However, warblers
of the genus Hippolais have rarely been reported as being victims of cuckoos, and furthermore, few data exist on the occurrence of antiparasite
defenses in these hosts. In this study, we examined possible host–parasite coevolution between cuckoos and eastern olivaceous
warblers (Hippolais pallida elaeica, hereafter olivaceous warblers) in three closely situated areas in northwestern Bulgaria. The olivaceous warbler has never
been reported to be a regular cuckoo host. However, the present study, carried out in 2001–2003 shows that the olivaceous
warbler is regularly and heavily parasitized by the cuckoo in this area. Parasitism rate was high (26.6%, 34/128) and consistent
among years, with some variation between areas. The cuckoo egg mimicry was moderately good, and olivaceous warbler rejection
rate of such eggs was 50%. Cuckoo eggs laid in olivaceous warbler nests had a whitish to whitish-green ground color, and the
majority appeared to be distinctly different from cuckoo eggs found in other host species in the area. The olivaceous warbler
proved to be a rather good host for cuckoos as 20.6% (7/34) of cuckoo eggs laid produced fledglings, a breeding success comparable
to other suitable hosts in Europe. This is the first in-depth study of brood parasitism in a warbler of the genus Hippolais, and cuckoos parasitizing olivaceous warblers probably represent a previously unknown gens. 相似文献