全文获取类型
收费全文 | 155篇 |
免费 | 3篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 6篇 |
环保管理 | 8篇 |
综合类 | 47篇 |
基础理论 | 22篇 |
污染及防治 | 42篇 |
评价与监测 | 8篇 |
社会与环境 | 6篇 |
灾害及防治 | 13篇 |
出版年
2023年 | 4篇 |
2022年 | 13篇 |
2021年 | 11篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 4篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1941年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
141.
河流生态系统管理研究——以香溪河为例 总被引:19,自引:0,他引:19
香溪河是三峡水库湖北库区最大的支流,其健康与否对三峡水库水质有直接影响,因此开展香溪河生态系统管理研究具有重要意义。然而,由于河流生态系统管理是一个新兴的研究领域,如何开展相关研究值得探讨。简要介绍了该领域的研究现状,并重点结合香溪河主要受水电站建设、流域土地不合理开发、工业污染等因素影响的事实,认为应该以保证水量、水质作为河流生态系统管理研究和各种管理措施的出发点,并以维持健康的水生态系统,保证河流各项服务功能的正常发挥为最终管理目标。以该思路为基础,就香溪河而言,可以着重从流域土地利用的生态学规划、香溪河水电站的生态学管理、香溪河流域水质污染源控制、香溪河生态系统健康和服务功能的监测及评价等四方面开展该河流的生态系统管理研究。 相似文献
142.
Anna Marszałek Grażyna Grabowska Krzysztof Łężak The Secret Study Group 《International journal of occupational safety and ergonomics》2019,25(2):268-277
Research into newly developed ballistic vests to be worn by police officers under clothing was carried out with air temperature conditions of +20 °C. A ballistic vest should incorporate protective features, comfort and ergonomics. The thermal strain on users who wore the vests was evaluated as an average and individually, after they had been conditioned in high (+50 °C), low (?40 °C) or neutral (+20 °C) air temperatures, while performing various occupational activities. Research involved six police officers aged 36–42 years, who wore civilian clothing used in moderate environmental conditions. During the tests, physiological parameters (internal temperature, local skin temperatures and amount of sweat secreted) were determined. The ease of doing exercises while wearing the vests, vest service and level of discomfort in use were assessed. Research showed that the vests tested, both as an average and individually, meet the requirements of Standard No. PN-V-87000:2011 (clause 4.5). 相似文献
143.
Mau Dung Nguyen 《Environment, Development and Sustainability》2011,13(1):35-50
This study investigated the compliance of paper-making plants in Phong Khe Commune of Bac Ninh Province with regulations on
wastewater management. According to existing regulations for wastewater management, all paper plants in Bac Ninh province
are required to submit an environmental impact assessment report, pay the wastewater charges, and establish a wastewater treatment
system. Many paper-making plants in the commune did not, however, comply with these regulations. Although fines were imposed
for non-compliance, only a few plants paid the fines due to weak enforcement. As a result, the current costs of compliance
of paper-making plants were very small compared with the full costs of compliance. Type of plant, location of the plant, and
number of schooling years of the plant owners were found to be significant factors affecting compliance. The main reasons
why the plants did not comply with the regulations were the plant owners’ inadequate understanding of environmental regulations,
their lack of financial resources, limited space for treatment system installation, small fines, and the limited capacity
of the local environment authorities in enforcing the regulations. The option of wastewater treatment for a group of paper-making plants located close to one another was widely accepted. The
study proposes collective action for the adoption of this treatment option and policy recommendations. 相似文献
144.
Bui Dung The 《Environment, Development and Sustainability》2003,5(3-4):461-476
Soil erosion is a significant problem in the uplands of the Central Coast, Vietnam. It affects the livelihood of farmers and could hinder the long-term economic development efforts in the uplands. Yet, trapped in poverty, upland farmers, especially the ethnic minority, are still mining the soil using erosive land use systems to meet their urgent needs. This study demonstrates that the level of soil erosion varies across the typical land use systems. The fruit tree-based agroforestry (AF) system is least erosive and most financially profitable. The choice of land use system is influenced by farmers' attributes, land plot characteristics, and policy-related variables. The set of policy variables is important in explaining land use choice by upland farmers. Promoting the switch to AF system and the adoption of soil conservation is of great importance to reducing soil erosion and sustaining development in the uplands. However, it is a very challenging task. 相似文献
145.
146.
Duong Minh Bui Phuc Duy Le Minh Tien Cao Trang Thi Pham Duy Anh Pham 《International Journal of Green Energy》2020,17(7):382-406
ABSTRACTTime-series and machine-learning methods are being strongly exploited to improve the accuracy of short-term load forecasting (STLF) results. In developing countries, power consumption behaviors could be suddenly changed by different customers, e.g. industrial customers, residential customers, so the load-demand dataset is often unstable. Therefore, reliability assessment of the load-demand dataset is obviously necessary for STLF models. Hence, this paper proposes a novel and unified statistical data-filtering method with the best confidence interval to eliminate unexpected noises/outliers of the input dataset before performing various short-term load forecasting models. This proposed novel data-filtering method, so-called the data pre-processing method, is also compared to other existing data-filtering methods (e.g. Kalman filter, Density-Based Spatial Clustering of Applications with Noise, Wavelet transform, and Singular Spectrum Analysis). By using an SCADA system?-based database of a typical 22kV distribution network in Vietnam, NYISO database, and PJM-RTO database, case studies of short-term load forecasting have been conducted with a conventional ARIMA model, an ANN forecasting model, an LSTM-RNN model, an LSTM-CNN combined model, a deep auto-encoder (DAE) network, a Wavenet-based model, a Wavenet and LSTM hybrid model, and a Wavelet Neural Network (WNN) model, which are to validate the novel and unified statistical data-filtering method proposed. The achieved numerical results demonstrate which the accuracy of the aforementioned STLF models can be significantly improved due to the proposed statistical data-filtering method with the best confidence interval of the input load dataset. The proposed statistical data-filtering method can considerably outperform the existing data-filtering methods. 相似文献
147.
148.
介绍了飞机不锈钢导管原位挤压扩口工艺和模具设计.该模具具有结构简单、易于加工、更换方便等特点,该工艺不仅适用于飞机导管修理,而且还可供其它设备导管修理时参考. 相似文献
149.
此文提出冲裁中,对于垂直面及垂直面非垂直切断的问题。并根据板料的回弹特性,提出了变形切断法,用普通模具,得以简便地解决提出的问题。 相似文献
150.
此文介绍采用壁厚达90mm的离心铸坯,旋压成形大直径高纯铝筒的工艺试验。讨论了旋压中出现的各种问题,从而确定了合理的工艺参数,旋出了符合技术要求的大直径筒形件。 相似文献