全文获取类型
收费全文 | 201篇 |
免费 | 7篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 43篇 |
废物处理 | 2篇 |
环保管理 | 26篇 |
综合类 | 65篇 |
基础理论 | 59篇 |
环境理论 | 2篇 |
污染及防治 | 5篇 |
评价与监测 | 3篇 |
社会与环境 | 5篇 |
灾害及防治 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 5篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 15篇 |
2007年 | 15篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
排序方式: 共有214条查询结果,搜索用时 15 毫秒
181.
利用成都市2016~2019年6~8月O3浓度的逐时监测数据以及该时段同时次的地面气象观测资料,构建了O3污染潜势3维(紫外辐射、相对湿度和气温)Copula联合概率分布模型,并开展了模型的适用性研究.首先,通过对SciPy库概率分布函数的优选,确定了不同O3浓度等级条件下紫外辐射、气温和相对湿度的最优边缘概率分布函数(均通过了显著性水平a=0.05的K-S检验);其次,计算了3种Copula联合概率分布函数的均方根误差(RMSE值)、赤池信息准则(AIC值)、贝叶斯信息量(BIC值),并借助Anderson-Darling检验,发现非对称3维frank Copula联合概率分布函数(M3Copula)可以最佳地表征不同O3浓度等级条件下紫外辐射、相对湿度和气温的联合概率分布特征;最后,将不同O3浓度等级条件下M3Copula联合概率密度作为对应O3浓度等级的隶属度,O3污染潜势的分类结果对实际O3浓度等级具有较好的指示意义,模拟的平均准确率为63%,其中优等级、良等级、轻度污染等级以及中度及以上污染等级的模拟准确率分别为82%、64%、48%和75%. 相似文献
182.
Using data from 23 populations of Indian langurs (Presbytis entellus), we show that the proportion of one-male groups is a function of the males’ ability to defend groups of females, as predicted
by the monopolisation model of Emlen and Oring (1977). However, we show that in addition to the number of females in the group
and their reproductive synchrony, home range size is also a factor, probably because it affects a male’s willingness to search
for other groups. These variables in turn are shown to be functions of environmental parameters (rainfall volume and seasonality,
and mean ambient temperature) which probably act via the density of resources and refuges in habitats.
Received: 3 March 1994 / Accepted after revision: 24 June 1996 相似文献
183.
Predictions of the model of van Schaik (1989) of female-bonding in primates are tested by systematically comparing the ecology,
level of within-group contest competition for food (WGC), and patterns of social behaviour found in two contrasting baboon
populations. Significant differences were found in food distribution (percentage of the diet from clumped sources), feeding
supplant rates and grooming patterns. In accord with the model, the tendencies of females to affiliate and form coalitions
with one another, and to be philopatric, were strongest where ecological conditions promoted WGC. Group fission in the population
with strong WGC was “horizontal” with respect to female dominance rank, and associated with female-female aggression during
a period of elevated feeding competition. In contrast, where WGC was low, females’ grooming was focused on adult males rather
than other females. Recent evidence suggests that group fission here is initiated by males, tends to result in the formation
of one-male groups, and is not related to feeding competition but to male-male competition for mates. An ecological model
of baboon social structure is presented which incorporates the effects of female-female competition, male-male competition,
and predation pressure. The model potentially accounts for wide variability in group size, group structure and social relationships
within the genus Papio. Socio-ecological convergence between common baboons and hamadryas baboons, however, may be limited in some respects by phylogenetic
inertia.
Received: 22 April 1994/Accepted after revision: 9 December 1995 相似文献
184.
企业安全管理群体行为与动力理论探讨 总被引:7,自引:1,他引:7
毛海峰 《中国安全科学学报》2004,14(1):45-49
企业职工个体总是存在于某个群体之中 ,为了适应群体和群体环境 ,个体的安全行为与其单独行动时的行为有所不同。笔者首先讨论了群体的概念、特征和类型 ;然后给出了安全管理群体行为的概念 ,即群体行为主体在该群体组织内进行的与安全生产有关的活动就是安全管理的群体行为 ,以及安全管理群体行为的特征(群体行为的规律性、群体行为的可测量性、群体行为的可划分性、群体行为对个体的影响性 ) ;最后论述了安全管理中的群体动力理论和群体动力对职工安全行为的影响 ,包括对安全绩效的社会促进与促退作用、安全社会标准化倾向、群体压力和从众行为等 相似文献
185.
苏北海州群云台组上段变火山岩富含碱性长石(60-70%)和钾长石(35-60%),黑云母为富铁黑云母,部分火山岩含霓辉石、萤石等.其岩石地球化学特征:高硅(SiO_2>6.41%),富碱(Na_2O+K_2O8.54%).高钾(K_2O4.52%),低铝(Al_2O_311.88%).贫钙、镁(CaO0.25%,MgO0.13%);富Nb、Zr、Y、Zn和Ga等元素;富REE、LREE和Eu强烈亏损.上述特征与世界和福建魁歧、浙江青田、江苏苏州、山东崂山等A型(或碱性)花岗岩的特征一致,为A型火山岩.其连云港市东部分布区是寻找与海相A型火山岩有关的Sn、W、Zn、Ph、Ag(Au)等华前型块状硫化物矿床和热液矿床的重要靶区. 相似文献
186.
系统描述了东北老工业基地以及资源枯竭地区目前发展所面临的困境,并以具体的实例说明了生态工业园区在促进上述地区走上新型工业化道路中的重要作用。 相似文献
187.
Thomas?D.?SeeleyEmail author P.?Kirk?Visscher 《Behavioral ecology and sociobiology》2004,56(6):594-601
This study addresses a question about the nest-site selection process of honeybee swarms: how do the scout bees know when to initiate the preparation for their swarm’s move to their new home? We tested the quorum-sensing hypothesis: that the scouts do this by noting when one of the potential nest sites under consideration is being visited by a sufficiently large number of scouts. A falsifiable prediction of this hypothesis is that delaying the formation of a quorum of scout bees at a swarm’s chosen nest cavity, while leaving the rest of the decision-making process undisturbed, should delay the start of worker piping (the prepare-for-takeoff signal) and thus the takeoff of the swarm. In paired trials, we presented each of four swarms once with five nest boxes close to each other at a site and once with a single nest box. The multiple nest boxes caused the scouts visiting the site to be dispersed among five identical nest cavities rather than concentrated at one. We observed long delays in the start of piping and the start of takeoff in the five-nest-box trials relative to the one-nest-box trials. These results provide strong support for the quorum-sensing hypothesis. 相似文献
188.
189.
We study interactions between resource distributions, grouping, and diet development in foragers who learn by trial-and-error. We do this by constructing an individual-based model where individuals move and forage in groups in a 2-D space with high resource diversity and learn what to eat. By comparing diet development in different resource distributions, and in gregarious and solitary individuals, we elucidate how these factors affect patterns of diet variation. Our results indicate that different resource distributions have profound effects on learning opportunities, and thereby lead to contrasting phenomena. In uniform environments, local resource depletion by gregarious individuals, in interaction with learning, leads to diet differentiation. In patchy environments, grouping leads to enhanced diet overlap within groups and leads to differences in diet between groups. Surprisingly, mixed environments can generate all these phenomena simultaneously. Our results predict relationships between diet variation, trial-and-error learning, and resource distributions. The phenomena we describe are not evolved strategies, but arise spontaneously when groups of individuals learn to forage in certain resource distributions. This suggests that describing diet specialization or diet homogenization as the result of behavioral strategies may not always be justified. 相似文献
190.
陈哲勇 《湖南环境生物职业技术学院学报》2006,12(1):69-72
目前,我国流动人口犯罪率居高不下,严重危及着社会的安定,已成为社会各界关注的热点和解决的难点问题.流动人口犯罪的主要表现特征为主体的复杂性,犯罪的团伙性、流窜性、侵财性等.相对剥夺论是流动人口犯罪一种可行的理论阐释,有助于深化我们对流动人口犯罪的理解.加强和完善政府职能是控制流动人口犯罪行之有效的应对措施. 相似文献