全文获取类型
收费全文 | 358篇 |
免费 | 20篇 |
国内免费 | 49篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 2篇 |
环保管理 | 115篇 |
综合类 | 125篇 |
基础理论 | 115篇 |
污染及防治 | 22篇 |
评价与监测 | 16篇 |
社会与环境 | 20篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 6篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 33篇 |
2012年 | 13篇 |
2011年 | 19篇 |
2010年 | 6篇 |
2009年 | 19篇 |
2008年 | 13篇 |
2007年 | 17篇 |
2006年 | 32篇 |
2005年 | 20篇 |
2004年 | 19篇 |
2003年 | 20篇 |
2002年 | 7篇 |
2001年 | 26篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有427条查询结果,搜索用时 31 毫秒
221.
丰、沛、铜重氟病区,禽、畜体内氟主要积聚在骨骼中(羊骨1096×10-6~2001.9×10-6,鸡骨335×10-6~378×10-6)及生理功能强的内脏(肝、心、肾等)器官中,氟的含量3.3×10-6~7.17×10-6,肌肉和蛋、奶品中氟的含量大多接近或低于氟的卫生标准,显然肉、蛋、奶食品不是该区地氟病的致病因子。研究表明,动物体内氟含量与环境水氟及叶菜和树叶(含水分高)中的氟含量呈明显的正相关。因而造成食草动物比以食粮食为主的家禽体内的氟含量明显偏高。说明水是氟的传播媒界,为该区地氟病的主要致病因子。 相似文献
222.
Lily Maynard 《Environmental Communication: A Journal of Nature and Culture》2018,12(2):177-190
Zoos and aquaria are controversial institutions, vilified by animal rights activists and championed by those who value their entertainment and educational resources. Examining media frames of these institutions can identify public perspectives. A qualitative content analysis was conducted for print and online magazine articles that discussed zoos and aquaria in North America. Sixty-five articles were analysed, and eight different frames were identified. The diverse frames highlight the differing roles of zoos and aquaria. Most of the articles were positive and supportive of zoos; 11% were negative. Animal welfare was the most common frame, from both positive and negative perspectives. Other frames, such as conservation and education, were less prevalent in the sample than expected, since zoos and aquaria portray themselves to be leaders in these fields. The unbalanced media discourse and small publication rate over the four years sampled suggest opportunities for increased media engagement on zoos and aquaria. 相似文献
223.
I. V. Emelyanova G. E. Donald D. J. Miron D. A. Henry M. G. Garner 《Environmental Modeling and Assessment》2009,14(4):449-465
A probabilistic Bayesian method called weights of evidence (WofE) was used to develop a synthetic dataset of cattle farm locations at a national scale across Australia. The synthetic
dataset was required for the modelling of livestock movements with a view to assessing biosecurity implications. The WofE method is based on the analysis of spatial relationships between evidential patterns with respect to an event, such
as the actual location of a farm. The evidential patterns of cattle farms were derived from maps of land use, land tenure,
drainage systems, roads, settlements and long-term averaged rainfall. These evidential patterns were used for delineating
and ranking land areas suitable for cattle farming. For each evidential pattern statistics such as a positive weight, a negative weight and a contrast were calculated for estimating the degree of correlation between the evidential patterns and known farm locations. The integrated
evidential patterns of known farms were then used for estimating posterior probabilities and splitting land into five different
classes according to its suitability for farming.
相似文献
I. V. EmelyanovaEmail: |
224.
Shunji Hashimoto Toshihiro Horiguchi Yasuyuki Shibata Masatoshi Morita 《Chemosphere》1999,39(15):1512-2669
PCDDs and PCDFs were analyzed by high resolution GC MS in several invertebrate animals collected from a rural beach in Japan. PCDDs and PCDFs were detected in all samples. Total concentration of PCDDs and PCDFs ranged 8.8–120 pg g−1 wet and 3.5–38 pg g−1 wet, respectively. TEQs of invertebrate animals examined ranged from 0.048 pg g−1 wet in sea slug to 0.91 pg g−1 wet in mussel. Isomer profiles in all samples were similar to each other despite of variety of species. Their major sources are estimated to be herbicides such as CNP and PCP, and combustion by using a statistical analysis of isomer profiles. 相似文献
225.
低聚糖或称寡糖是由2-10个单糖分子通过糖苷键连接组成的小聚合体。作为一种新型的功能性饲料添加剂,在动物体内可促进消化道有益菌的生长,抑制有害病原菌的繁殖,提高动物机体免疫力。多数试验研究表明,饲料中添加适量低聚糖,能在较大程度上替代抗生素而改善动物健康,增强抗病力,提高家禽及幼龄动物成活率,提高动物的生长增重和饲料转化率。 相似文献
226.
Perfluorinated compounds (PFCs) are man-made fluorinated hydrocarbons, which are very persistent in the environment. Since the early 1980s, the usage of PFCs has sharply increased for a wide array of industrial and commercial applications. Being the most important PFC, perfluorooctane sulfonate (PFOS) has received much attention. In the past decades, increasing surveys have been focused on this compound, to study its sources, fates and effects in the environment. According to the large production volume and wide usage in industrial and commercial products in the past, PFOS can be detected in various environmental media and matrix, even in human tissues. This article attempted to review the current status of PFOS contaminations in Asia, focusing on water systems, sediments, wide animals and human tissues. A special section is devoted to examine the pathways of human exposure to this compound, as well as human body loadings of PFOS and their possible association with diseases. 相似文献
227.
动物细胞的体外培养需要多种生长因子。本研究假设Vero细胞生长和对营养物的吸收利用与一个关键生长密切相关,一个控制变量c控制这一关键生长因子的合成。根据这假设建立了一个简单的Vero细胞生长的控制模型,该模型较好地描述了细胞从延迟期到静止期的整个生长过程。 相似文献
228.
Itay Fischhendler Dror Boymel Maxwell T Boykoff 《Environmental Communication: A Journal of Nature and Culture》2016,10(2):147-168
Although solar farms are often favorably received by the public due to their contribution to clean energy, they are not conflict-free. In various contexts, this land-intensive technology often competes with other land uses like agriculture, nature reserves, and army training. As a result of this competition, interest groups often seek political leverage in order to prioritize their spatial use. Framing their uses as existential is one possible way to capture the attention of decision-makers. Yet, this securitization process may create a framing contest whereby different actors use similar securitization language to promote different land uses. This study is the first attempt to trace how this framing contest of securitized discourses over land appropriation is constructed. It is based on the Israeli experience of promoting solar energy in the Negev Desert, an area conceived as available to solar development. Through an analysis of protocols of Israeli policy-makers’ meetings between 2002 and 2011, the study documents the ways in which players adopt securitized language concerning various land uses such as energy, food, ecology, and traditional (national) security. The study found that the use of securitized framing varies between uses, forums, actors, and sectors. Yet competition between securities discourses remained uneven as, in the Israeli context, many players find it difficult to challenge the hegemonic role of traditional (national) security. 相似文献
229.
基于虹膜识别的肉类食品可追溯系统研究 总被引:6,自引:3,他引:6
为了加强食品安全管理,提高肉类食品溯源准确性的目的,首先提出肉类食品溯源体系的3个基本要素,认为:动物个体识别是肉食品质量控制的重要环节;采用虹膜识别作为大型动物个体识别的关键技术;解决了其他动物识别系统中的欺骗以及设备功能异常现象等问题。以奶牛为例,讨论人眼虹膜识别技术应用于大型动物识别在图像采集、虹膜定位、特征提取3方面存在的技术难点;给出了实现动物虹膜识别的技术路线;最后构建了基于虹膜识别的肉食品可追溯系统。通过详细功能划分和流程设计,为虹膜技术在肉食品可追溯系统中的应用实施提供了参考。 相似文献
230.
本文在对动,植物生态学研究进展论述的基础上,提出在退化生态系统的恢复与重建过程中,运物种群与植物种群具有密切相关性的构思,认为动物种群与植物种群以“联合种群”的方式存在于此系统中,二者应作为一个有机的整体来加以研究。 相似文献