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621.
● Six largely produced agricultural biomass wastes were pyrolyzed into biochars. ● Feedstock type significantly determined physiochemical properties of biochars. ● The biochars showed powerful adsorption capabilities to Plasticizer DEP. ● Giant reed biochar with higher DEP adsorption was a prominent sorbent. Plastic pollution as a global environmental issue has become a research hotspot, among which the removal of inherent plasticizer (e.g., phthalic acid esters, PAEs) received increasing attention. However, the effects of biochars derived from different feedstocks on the adsorption of PAEs are poorly understood. Thus, the characteristics of biochars derived from six largely produced biomass wastes in China at 400 °C, as well as their performance in adsorption of diethyl phthalate (DEP), one of frequently detected PAEs in aqueous environment, were investigated. The results indicated that the variation in feedstock type showed significant changes in the properties (e.g., porosity, specific surface area, surface functional groups) of biochars, which affected DEP adsorption and desorption. Pseudo-second order and Freundlich models fitted the adsorption data well, and adsorption mechanisms mainly included hydrophobic effect, followed by micropore filling, hydrogen bonding, and π-π EDA interactions. Adsorption thermodynamics revealed that the adsorption was a spontaneous and exothermic the adsorption capacities of DEP on these biochars slightly decreased with the increasing pH but increased with the increasing ionic strength. Among these biochars, the giant reed biochar with relatively higher DEP adsorption and low desorption exhibited the great efficiency for DEP removal as an environment-friendly sorbent. These results highlighted the significant roles of micropore filling and hydrogen bond in determining adsorption capacity of designed biochars prepared from selecting suitable agricultural straws and wetland plant waste to typical plasticizer. The findings are useful for producing designed biochars from different biomass wastes for plasticizer pollution control.  相似文献   
622.
北京大气气溶胶部分无机组分及相关气体的浓度变化   总被引:20,自引:4,他引:16  
利用SJAC-MOBIC在2000-05~2000-09的3个采样时段测量了北京大气中的气溶胶SO42-、NO3-、NO2-、Cl-及相关气体组分,得出了这些污染组分的逐时变化.结果表明气溶胶Cl-、NO2-、NO3-及气体HCl、HNO2和HNO3有明显的变化规律,SO2和气溶胶SO42-的变化取决于SO2的排放,SO42-的峰值一般比SO2的峰值晚2h左右.  相似文献   
623.
Chen  Yiqun  Gao  Shuxian  Liu  Zizheng  Shao  Senlin  Yin  Weizhao  Fang  Zheng  Huang  Li-Zhi 《Environmental Chemistry Letters》2019,17(2):1017-1021
Environmental Chemistry Letters - Metal-activated persulfate is an efficient reagent for the oxidative degradation of organic contaminants. However, homogenous catalytic activation of persulfate...  相似文献   
624.
全氟化合物污染现状及风险评估的研究进展   总被引:3,自引:0,他引:3  
全氟化合物(polyfluorinated compounds,PFCs)是近年来受到广泛关注的一类新型持久性有机污染物。PFCs因具有优良的化学稳定性、耐热性以及高表面活性,而被广泛应用于生活消费和工业生产等领域。PFCs具有难降解、生物富集和长距离迁移等特点,已在大气、土壤和水体等环境介质及生物体中检出。在生态环境中,PFCs能够通过食物链不断传递放大,其具有的多种毒性效应已对生态系统和人类造成了一定的威胁。本文主要综述了PFCs在各类环境介质的污染现状、生物的毒性效应、人类摄入健康风险评估以及PFCs的降解研究,以期为未来PFCs的研究提供参考。  相似文献   
625.
离子选择性微电极(ISME)是一种电化学传感器。在单细胞检测中可用来测定细胞内各种离子的浓度和胞外空间的离子流。本文提出了一种离子选择性微电极用于单细胞检测的新方法,即用离子选择性微电极测量植物细胞原生质体破裂时形成的离子浓度脉冲信号,进而分析细胞液中离子浓度的分布。并用此方法研究了在低温、纳米氧化铜(CuO NPs)、重金属(铽、镉)和乙醇等不同因素作用下,芦荟(Aloe vera)细胞原生质体的细胞液中Ca~(2+)的浓度分布。实验结果表明,在冷冻、CuO NPs、硝酸铽和氯化镉处理后细胞液中的Ca~(2+)浓度分布发生分层现象,而乙醇处理则不会出现这种现象。这种方法具有抗干扰能力强和操作简便的优点,为更全面地揭示细胞对外界刺激的响应特征提供了新的视角,也可为各种环境和生态毒理学评价提供新的途径。  相似文献   
626.
A total of six nuclear reactors installed in three power plants, two along the northern and one along the southern coasts of Taiwan, started their operations one after another since October 1977. Owing to the large quantities of cooling water intake into and discharge from the plants, some environmental factors such as water temperature, chlorine, environmental radioactivity and nearshore currents may be significantly changed. Variations of these abiotic environmental factors may influence the biological activities in the ecosystem, particularly doing some kinds of damage to marine biological resources. Therefore, the possible environmental impact upon the biological systems including the fishery resources along the northern and southern coasts of Taiwan should be studied before and during the plant operation.

We have started the long-term programmes of biological, chemical and hydro-graphical surveys of the nuclear power plant sites on both northern (since July 1974) and southern (since July 1979) coasts of Taiwan. the survey items include ocean currents, physical and chemical properties of sea water, primary productivity, specific compositions and interspecific relationships among phyto- and zooplankton, algae, invertebrates, corals, and fishes; and radionuclides in water and biological specimens, and fishery statistics. in general, except for a few events, the operations of the six units of nuclear power plants have not produced detectable effects on the marine ecosystem. Radio activity levels and radionuclides in water and the biological specimens remained the same as background levels throughout the survey period. However, the events of coral bleaching and fish body anomalies caused by thermal discharges were observed respectively along the outlets of third and second Nuclear Power Plants. the purposes of this paper are to report and evaluate these two events during the operations of nuclear power plants in Taiwan.  相似文献   
627.
SUMMARY

Arid and semi-arid environments undergo periodic seasonal agricultural droughts of varying extents and duration, erratic and ineffective rainfall of high intensity and short duration, with high surface runoff. High efficiency water-harvesting agriculture has been routinely used in the Loess Plateau agricultural production of China over the past 10 years. Localized habitat effect and regional water resource enrichment are the theoretical basis of high efficient water-harvesting agriculture. Features of this agricultural system are described, including: water harvesting of surface runoff from roads and collection in concrete yards on plastic sheets; water storage cellar tanks for harvesting runoff to provide life-saving/critical irrigation, with devices for water lifting and conveying such as hand pumps and pipelines; feasible methods of water use for limited supplies such as drip, hole, subsoil, and super-sheet irrigation; agronomic measures of high water use efficiency; and field micro-catchment for water harvesting and conservation to increase fallow efficiency in rainy seasons. Using the stored runoff water to irrigate the mulched winter wheat and spring corn, as well as vegetables and fruit trees, significant yield increasing and water use efficiency improvements have been achieved. Plastic mulching for increasing fallow efficiency in rainy seasons and improving yield of the next winter wheat crop have been developed and demonstrated. These techniques have provided obvious benefits in terms of soil and water conservation on slope farmland in the hill regions and remarkable effects of storing water and reducing drought in the dryland farming regions have been obtained.  相似文献   
628.
长江流域旱涝灾害特征研究   总被引:2,自引:0,他引:2  
利用长江流域地区(1956-2007年)148个站点全年的逐日降水资料,采用Z指数作为旱涝指标,对长江流域地区旱涝的转化规律及其时空变化特征进行了探讨,结果表明:长江流域降水量具有明显的年际变化,夏季和年降水量的变化趋势一致;春季的降水周期较夏季具有明显的周期性,从研究的时段内看,春季降水周期为17 ~21年为主,夏季以10~ 15年为主周期;旱涝灾害发生的频率与降水量、暴雨出现的频数呈现正相关,旱涝空间分布上存在一定的结构性,干旱大都发生在长江上游地区(四川和云南的一部分地区)以及湖北部分地区,洪涝主要发生于长江中下游地区,特别是在湖南、安徽、湖北等地.  相似文献   
629.
水污染的防治问题是我国关注的重中之重,现有理化监测方法的实时性和综合性较差,特别是对于一些极端可变化的环境,更需要新的方法以辅助和解决。生物式水质监测方法被提出,通过利用生物对环境污染或变化所产生的反应来直接或间接体现水质的污染情况。然而,观测指标与量化标准是面临的一大难题。文章利用机器视觉的方法,以青鳉鱼为模式生物,并以青鳉鱼的生理特征以及运动特征(呼吸频率、胸鳍摆动频率、摆尾频率)为观测指标,两方面综合评定青鳉鱼应激状态,实时监测与分析。实验结果表明该方法能为生物式水质监测和预警的发展提供一定支持与参考。测得青鳉鱼呼吸频率为3.06 Hz,胸鳍摆动频率为4.83 Hz,尾鳍摆动频率为5.08 Hz,结果与实际指标一致。  相似文献   
630.
本研究旨在探讨BDE 209长期暴露对出生后不同发育阶段子鼠血液系统的影响。将75只雌性昆明小鼠随机分为对照组、低剂量组(1.5 mg·kg-1·d-1)和高剂量组(225 mg·kg-1·d-1)。BDE 209暴露10 d后,将雌鼠与雄鼠合笼。选取怀孕时间相近(相差不过2 d)的10只孕鼠持续染毒直至自然分娩。出生后子鼠在哺乳期通过母乳染毒,断乳后则按照与母鼠相同的方式进行染毒,并在不同时间点进行外周血常规、外周血形态学、骨髓细胞形态学、骨髓细胞染色体组型和数目分析。血常规结果显示,低、高剂量BDE 209暴露对出生后不同发育阶段子鼠的白细胞计数没有影响,即白细胞、中性粒细胞、淋巴细胞及单核细胞的数量均无显著变化(P0.05);红细胞系统检查显示一定性别差异,即低剂量和高剂量BDE 209染毒的雄性小鼠在PND30出现红细胞(RBC)(P0.05)、血红蛋白(Hb)(P0.05或P0.01)及红细胞压积(P0.05或P0.01)的显著降低;而雌性小鼠只在PND 30出现红细胞压积的降低(P0.05);在PND 30,高剂量暴露组的雌性及雄性小鼠,低剂量暴露组的雌性小鼠均出现血小板计数的显著降低(P0.05或P0.01);而PND 60、PND 90的实验组血小板均未观察到显著改变(P0.05)。外周血形态学检查表明,低剂量组在PND 30、PND 60,及高剂量组在PND 90检测到典型异常结果多表现为白细胞数的增多。而低剂量组在PND 90检测到的典型异常结果多表现为异型深染淋巴细胞(P0.05)。骨髓形态学检测表明,低剂量组子代雄性及雌性小鼠在PND 60、PND 90骨髓涂片可检测到骨髓细胞的异常结果,表现为骨髓增生活跃,高剂量组雄性小鼠在PND 90观察到3例异常涂片,表现为骨髓增生异常(P0.05)。研究结果表明,BDE 209长期暴露可能导致出生子代外周血和骨髓的毒性,提示具有血液系统发育毒性。  相似文献   
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