全文获取类型
收费全文 | 184篇 |
免费 | 11篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 4篇 |
环保管理 | 27篇 |
综合类 | 83篇 |
基础理论 | 35篇 |
污染及防治 | 11篇 |
评价与监测 | 12篇 |
社会与环境 | 28篇 |
灾害及防治 | 18篇 |
出版年
2024年 | 1篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 15篇 |
2007年 | 11篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 12篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有218条查询结果,搜索用时 46 毫秒
91.
沿海生态旅游资源评价指标及尺度研究——以江苏沿海为例 总被引:22,自引:0,他引:22
旅游资源评价是生态旅游研究的主要内容之一,尺度选取和指标建立是评价的关键。从生态旅游的角度出发,筛选体现沿海湿地类型、生态环境、旅游期望值、海洋文化以及开发程度等项目的一系列指标,综合构建沿海生态旅游资源评价指标体系。运用景观生态学理论,文章提出了沿海生态旅游资源(景观)评价的时空尺度、自然人文理性尺度以及数理统计尺度。在此基础上,运用层次分析法对江苏沿海生态旅游资源的吸引力、开发潜力和综合价值进行定性和定量评价,并探讨了发展江苏沿海生态旅游的策略。 相似文献
92.
西部大开发与现代集约持续农业 总被引:9,自引:0,他引:9
卢良恕 《中国人口.资源与环境》2001,11(1):50-54
本文在分析西部大开发面临的机遇与挑战的基础上,阐述了我国发展现代集约持续农业的必然性,并对我国现代集约持续农业的目标、内容、重点领域及发展现代集约持续农业应注意的问题进行了探讨。 相似文献
93.
Renato A. M. Silvano John Valbo-Jørgensen 《Environment, Development and Sustainability》2008,10(5):657-675
Studies investigating the local ecological knowledge (LEK) held by fishermen about the fishing resources have indicated that
fishermen’s LEK may have the potential to improve fishery management, by providing new information about the ecology, behavior
and abundance trends of fish and other aquatic animals. Our major aim is to undertake a brief review of published ethnoichthyological
studies with a focus on coastal Brazilian fisheries and freshwater fisheries in both Brazil and Southeast Asia. Based on such
review, we provide 29 hypotheses on fish ecology based on fishermen’s LEK and compare them with what is already known from
the biological literature, using an arbitrary ‘likelihood’ measure: “Low likelihood” corresponded to unexpected hypotheses,
which contradict existing biological data. “Medium likelihood” corresponded to hypotheses that could not be compared to available
scientific knowledge. Hypotheses that agree with scientific data were considered as “High likelihood”. We therefore discuss
these three categories of hypotheses about several distinct topics, such as migration, reproduction, feeding habits, abundance
patterns, ecological relationships between fish and their predators, and fishing pressure. Our results may contribute to the
fisheries management and research in the studied regions and other similar places, besides raising the interest of biologists
to properly include fishermen’s LEK when planning and conducting fisheries surveys.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
94.
Han Mei Zhou Baohua Yang Peilin Gao Guiqin & Zhang Weiying . Department of Geography Shandong Normal University Jinan China . Department of Geography Jinan University Jinan China 《中国人口.资源与环境(英文版)》2005,(4)
1INTRODUCTIONAncient lakes are lakes that once existed in history,butnow have died out.As a kind of land water and geomorphicconfiguration,the formation and evolution of ancientlakes were closely linked with the variance of geographicenvironment.The south coast plain of Laizhou Bay is aplain extending from the estuary of the Xiaoqing Riverin the west to the estuary of the Jiaolai River in the east.There were once some lakes on the plain in history,suchas Judian Lake,Qingshuibo Lake,an… 相似文献
95.
Topography and vegetation of restored dunes on a developed barrier island were examined after a large-scale beach nourishment
project. Restoration began in 1993 using sand-trapping fences andAmmophila breviligulata Fern. plantings. Subsequent growth of dunes was favored by installing new fences and suspending beach raking to accommodate
nesting birds. Plant species richness, percent cover of vegetation, and height ofA. breviligulata were sampled in 1999 on seven shore perpendicular transects in six dune microhabitats (backdune, primary crest, mid-foredune,
swale, seaward-most fenced ridge, incipient dune on the backbeach).
A total of 26 plant taxa were found at all seven sites. Richness and percent cover were greatest in the backdune and crest,
especially in locations that predated the 1992 nourishment. Richness was greater where fences enhanced stabilization. Fences
initially compensate for time and space and allow vegetation to develop rapidly, but maintenance nourishment is required to
protect against wave erosion and ensure long-term viability of habitat. An expanded environmental gradient is an option, where
beach nourishment provides space for a species-rich crest and backdune to develop, while the incipient dune remains dynamic.
Options where space is restricted include a dynamic, full-sized seaward section of a naturally functioning dune (truncated
gradient) or a spatially restricted sampler of a wider natural dune (compressed gradient) maintained using fences. Expanded
and truncated gradients may become self-sustaining and provide examples of natural cycles of change. Compressed gradients
provide greater species richness and flood protection for the available space, but habitats are vulnerable to erosion, and
resident views may be impaired. 相似文献
96.
滨岸潮滩是海岸带的重要组成部分和主要的地理景观 ,具有多种环境功能和生态价值 ,对沿海地区的经济发展起着重要的作用 ;同时滨岸潮滩又是一个环境脆弱带和敏感区 ,极易受人为活动的干扰和破坏。生物多样性是人类生存和经济得以持续发展的基础。滨岸潮滩是生物多样性最为丰富的生态系统之一。通过对上海滨岸潮滩生物多样性影响因素的调查与分析 ,研究了目前人类活动对上海滨岸潮滩生物多样性造成的严重威胁 ,污水的排放使滨岸潮滩水质和底质严重污染 ,对滨岸潮滩的围垦改变了潮滩的自然本底状态 ,造成潮滩生物生长发育和栖息的环境受到破坏 ,影响滨岸潮滩生物多样性。指出滨岸潮滩等方面的社会与环境价值 ,并探讨了上海滨岸带开发与滨岸潮滩生物多样性的保护和利用问题 相似文献
97.
广东典型海水养殖区沉积物及鱼体中磺胺类药物的残留及其对人体的健康风险评价 总被引:9,自引:2,他引:7
采用高效液相色谱-紫外检测器(HPLC-UV)分析了广东沿海大亚湾和阳江两个典型海水养殖区中沉积物以及7种养殖鱼类肌肉和肝脏组织中磺胺嘧啶(SDZ)、磺胺二甲嘧啶(SM2)和磺胺甲基异噁唑(SMX)的残留量,并依据药品最高残留量(MRL)值和每日允许摄入量(ADI)值对海水养殖鱼类中磺胺类抗生素污染进行人体健康风险评价.结果表明,在所有沉积物样品中都能检出磺胺类抗生素.含量(干重)范围为:2.1~35.2 ng·g-1,检出率大小顺序为SDZ(85.7%)>SM2(71.4%)>SMX(28.6%).大亚湾养殖区磺胺药物在沉积物和鱼类样品中的检出频率大于阳江养殖区.3种磺胺类药物在鱼肝脏组织中的含量显著高于在肌肉组织中的含量(P<0.05).SDZ、SM2和SMX在鱼体肌肉组织中的含量(湿重)范围分别为11.6~37.9、16.3~27.8和4.9~20.0 ng·g-1.3种磺胺类药物的平均日摄入量范围为3.37~36.72 ng·kg-1,仅占食用肉类ADI的最高限值(50μg·kg-1)的0.007%~0.073%(<1%ADI),健康风险为可以忽略,膳食安全性高. 相似文献
98.
99.
福建罗源湾潮间带沉积物重金属含量空间分布及其环境质量影响 总被引:6,自引:2,他引:4
潮间带是典型的环境脆弱带和敏感带.为探明福建罗源湾潮间带的环境质量,于2009年在该区开展了野外调查,利用电感耦合等离子体发射光谱仪(ICP-AES)测定了该区表层沉积物中重金属(Co、Cr、Cu、Ni、Pb、V、Zn)浓度,用潜在生态风险评价法评价了该区的环境质量.结果表明,整个潮间带表层沉积物主要是粉砂和黏土质粉砂,重金属元素(Co、Cr、Cu、Ni、Pb、V、Zn)的平均含量分别为:20.48、77.82、23.24、40.67、36.25、134.75、111.21 mg.kg-1;互花米草盐沼区表层沉积物中重金属含量明显高于光滩区;与其它地区相比,本区表层沉积物重金属含量明显高于福建海岸带土壤背景值,但低于珠江口地区.主成分分析和相关分析表明,工业排污和生活污水是本区重金属污染的主要来源,而矿床开采以及有机质降解产生的内源释放也是该区重金属元素来源的主要途径之一.潜在生态风险评价显示,研究区具中等程度的潜在生态危害风险;Ni和Co是主要环境污染因子,Pb的污染程度较低;互花米草盐沼的潜在生态风险高于光滩区,不同重金属的潜在生态危害程度顺序为Ni>Co>Cu>Pb>Cr>V>Zn. 相似文献
100.
吉林西部原有生态系统敏感脆弱,若采用河湖连通势必会对原有的生态系统产生一定影响.主要从河湖连通后会对养殖水域水质可能出现的现象和问题进行研究,通过对氟化物、非离子氨、凯氏氮、生化耗氧量、硫酸盐与硫化物、氮磷比、本底性污染、河流湖泊退化等多个因素分析了河湖连通后潜在的生态危机,以及灌区退水及鱼产力影响西部河湖连通生态效益的主要因素,提出了切实改善西部河湖连通生态影响的建议. 相似文献