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991.
李鑫  乔琰  钟国祯 《环境科学》2015,36(11):4319-4324
多环芳烃是一类普遍存在的环境污染物,可以诱发癌症,对人们的健康造成严重威胁.本研究利用一种四环芳烃芘的衍生物作为半抗原,利用活泼酯法合成人工抗原免疫小鼠研制多环芳烃单克隆抗体.通过非竞争性ELISA与竞争性ELISA相结合的筛选方式得到一株单克隆抗体,命名为6A6.该抗体能特异性识别芘和苯并芘,其IC50值分别为8.1μg·L-1和6.8μg·L-1,对其他多环芳烃的交叉反应率均低于5%.在此基础上,建立了免疫传感器法对芘和苯并芘进行检测,线性范围为0.2~10.0μg·L-1.利用该方法对添加在水样中的样品进行回收,并与传统ELISA方法进行比对,结果证明传感器法检测更加快速且灵敏度更高.该方法可以用于含有芘和苯并芘的环境样品的快速筛选,可以在10 min内初步获得检测结果.  相似文献   
992.
2009年1—8月于滇池外海水体随机取样20组,监测叶绿素a项目,采用两种不同监测分析方法,对其监测结果,应用线性函数Y=a+bx的形式,进行了一元线性回归相关关系(r)值的显著性检验,验证了两种监测方法之间的相关关系。  相似文献   
993.
黄文超 《环境保护科学》2013,39(4):57-60,96
根据2009~2012年水源地水质自动监测所得数据,分析叶绿素a的动态变化与环境因子的相关关系,筛选影响叶绿素a含量变化的环境因子。分析表明:该水源地水库水质状况属贫营养型,其中叶绿素a含量变化主要受总磷、水温、高锰酸盐指数影响,以这3种影响因子建立起的多元回归方程能较好的预测水库叶绿素a的变化趋势。  相似文献   
994.
杨凡  纪道斌  王丽婧  李虹  李莹杰 《环境科学》2020,41(5):2107-2115
采用2018年9月对三峡水库典型一级支流——香溪河和神农溪回水区水质监测数据,分析和对比了香溪河和神农溪的溶解氧和叶绿素a等指标垂向分布特征,讨论了影响其垂向分布的环境因子.结果表明,香溪河与神农溪的溶解氧含量在表层0~10 m和0~12 m水体分层现象明显,且随水深增加而递减.其表层水体的溶解氧饱和度S_(DO)分别为139.20%和107.78%,已经达到过度饱和状态(S_(DO)100%);中层与底层水体溶解氧浓度较稳定,无分层现象.香溪河和神农溪回水区水体中叶绿素a垂向分布与溶解氧分布的规律一致,表层水体中叶绿素a浓度整体上表现为中度富营养化(5μg·L~(-1)Chl-a20μg·L~(-1)).Pearson相关性分析显示,香溪河与神农溪水体中的溶解氧与水温、浮游植物垂向分布之间存在显著相关性,水温分层以及浮游植物的生命活动是影响溶解氧垂向分布的关键因素.叶绿素a与水温和pH呈现出显著的正相关性,与浊度表现为显著负相关性,表明浮游植物垂向分布主要受光照强度沿水深衰减和水温分层现象的影响.  相似文献   
995.
根据《“十二五”主要污染物总量控制规划编制技术指南》提供的公式,预测社会经济发展主要参数,包括GDP、能源消费总量、煤炭消费量等指标。二氧化硫新增量预测以宏观测算方法为主,并按行业测算方法予以校核。宏观测算分为火电行业和非电力行业,结果为1.419万t;分行业预测分为石化、建材(水泥)、有色、冶金和其他行业,结果为1.774万t,两者预测偏差为25%,采用分行业预测结果作为2015年二氧化硫新增量预测。  相似文献   
996.
Retractable type fall arresters are designed to protect against falls from a height of people who need freedom of vertical movement. The practice of fall protection shows that the devices are also used to protect people who work on flat roofs. This application creates quite different operating conditions for the devices. In some situations those conditions can be dangerous for users. The article presents a theoretical analysis of phenomena occurring during a fall arrest with retractable type fall arresters arranged horizontally. The analysis was verified with laboratory tests. The article presents a proposal for the construction of a test stand and a test method for estimating retractable type fall arresters intended for horizontal use.  相似文献   
997.
Retractable type fall arresters are very effective personal equipment protecting against falls from a height. These devices are used under different atmospheric conditions and in the presence of various types of industrial pollution. For this reason appropriate locking after conditioning simulating extreme conditions of a worksite is one of the essential characteristics of retractable type fall arresters. This article presents the requirements for locking of the devices. A previously used locking test method and its disadvantages are discussed. The article suggests an improved test method and test equipment. Measurement of the test mass acceleration is the most important improvement introduced into the test method. The article shows laboratory tests used to verify the method, which turned out to be a valuable source of information concerning the performance of retractable type fall arresters.  相似文献   
998.
Back in 1992, the Gulf of Aqaba Environmental Action Plan (GAEAP), a collaboration between the Aqaba Region Authority (ARA), Jordan and the World Bank, gave considerable emphasis to the environmental protection of the Gulf of Aqaba [The World Bank. Gulf of Aqaba Environmental Action Plan. Report No. 12244JO (1993).]. The document recommended the establishment of a marine reserve and the long term monitoring of the coastal habitats' environmental quality. The combination of a dedicated follow up, the collaborative efforts of ARA and the Marine Science Station (MSS), and the founding of the Aqaba Special Economic Zone Authority (ASEZA) have turned the recommendations into reality. A comprehensive monitoring program of the Jordanian coastal habitats commenced in 1999. The first three years of the program were financed by a donation from The Global Environmental Facility (GEF). In return, Jordan has committed itself to the maintenance of the monitoring program as an ongoing tool for sustainable coastal management. The monitoring program includes observations on benthic habitat, fish communities, bottom sediments and seawater quality. This paper focuses on the results of seawater-quality monitoring in the first three years. Records of weather conditions, coastal currents, seawater temperature, transparency, salinity, density, pH, alkalinity, dissolved oxygen, ammonia, nitrate, nitrite, phosphate, silicate, particulate matter, chlorophyll a, zooplankton biomass, total coliform, fecal coliform, hydrocarbons and sedimentation rate have been generated monthly since January 1999 at six coastal stations, and one offshore reference station, in the Jordanian waters of the Gulf of Aqaba. The coastal stations are located at sites with different benthic habitats and are occupied by different human activities. Offshore records of density (thermohaline structure), nutrients and chlorophyll a depicted two well-defined seasons; a nutrient-/chlorophyll a-rich, mixed water winter from December to April and a nutrient-/chlorophyll a-poor, stratified water summer from June to October. Short transition seasons appeared in May and November. The mixing and stratification seasons were also clearly depicted in the coastal waters. Statistical analysis of the three-year data collected at the offshore station revealed no significant inter-annual differences in the upper 125 m of the water column with respect to any of the measured parameters. At coastal stations, the water quality at the two northernmost stations was significantly different in comparison to the upper 125 m at the offshore station and to the other coastal stations, with respect to the two key indicator parameters: inorganic nitrogen and chlorophyll a. The three-year findings of the monitoring program are employed to suggest standard codes of reference for the coastal water quality.  相似文献   
999.
Abstract: Climate‐change scenarios project significant temperature changes for most of South America. We studied the potential impacts of predicted climate‐driven change on the distribution and conservation of 26 broad‐range birds from South America Cerrado biome (a savanna that also encompass tracts of grasslands and forests). We used 12 temperature or precipitation‐related bioclimatic variables, nine niche modeling techniques, three general circulation models, and two climate scenarios (for 2030, 2065, 2099) for each species to model distribution ranges. To reach a consensus scenario, we used an ensemble‐forecasting approach to obtain an average distribution for each species at each time interval. We estimated the range extent and shift of each species. Changes in range size varied across species and according to habitat dependency; future predicted range extent was negatively correlated with current predicted range extent in all scenarios. Evolution of range size under full or null dispersal scenarios varied among species from a 5% increase to an 80% decrease. The mean expected range shifts under null and full‐dispersal scenarios were 175 and 200 km, respectively (range 15–399 km), and the shift was usually toward southeastern Brazil. We predicted larger range contractions and longer range shifts for forest‐ and grassland‐dependent species than for savanna‐dependent birds. A negative correlation between current range extent and predicted range loss revealed that geographically restricted species may face stronger threat and become even rarer. The predicted southeasterly direction of range changes is cause for concern because ranges are predicted to shift to the most developed and populated region of Brazil. Also, southeastern Brazil is the least likely region to contain significant dispersal corridors, to allow expansion of Cerrado vegetation types, or to accommodate creation of new reserves.  相似文献   
1000.
Objective: This study aimed at identifying and predicting in advance the point in time with a high risk of a virtual accident before a virtual accident actually occurs using the change of behavioral measures and subjective rating on drowsiness over time and the trend analysis of each behavioral measure.

Methods: Behavioral measures such as neck bending angle and tracking error in steering maneuvering during the simulated driving task were recorded under the low arousal condition of all participants who stayed up all night without sleeping. The trend analysis of each evaluation measure was conducted using a single regression model where time and each measure of drowsiness corresponded to an independent variable and a dependent variable, respectively. Applying the trend analysis technique to the experimental data, we proposed a method to predict in advance the point in time with a high risk of a virtual accident (in a real-world driving environment, this corresponds to a crash) before the point in time when the participant would have encountered a crucial accident if he or she continued driving a vehicle (we call this the point in time of a virtual accident).

Results: On the basis of applying the proposed trend analysis method to behavioral measures, we found that the proposed approach could predict in advance the point in time with a high risk of a virtual accident before the point in time of a virtual accident.

Conclusion: The proposed method is a promising technique for predicting in advance the time zone with potentially high risk (probability) of being involved in an accident due to drowsy driving and for warning drivers of such a drowsy and risky state.  相似文献   

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