全文获取类型
收费全文 | 100篇 |
免费 | 8篇 |
国内免费 | 46篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 14篇 |
环保管理 | 8篇 |
综合类 | 77篇 |
基础理论 | 2篇 |
污染及防治 | 35篇 |
评价与监测 | 2篇 |
社会与环境 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 2篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 312 毫秒
51.
52.
In this study, an innovative heat and mass transfer core is proposed to provide thermal comfort and humidity control using a hollow fiber contactor with multiple bundles of micro-porous hollow fibers. The hollow fiber-based core utilizes 12 bundles aligned vertically, each with 1,000 packed polypropylene hollow fibers. The proposed core was developed and tested under various operating and ambient conditions as a cooling core for a compact evaporative cooling unit and a dehumidification core for a liquid desiccant dehumidification unit. As a cooling core, the fiber-based evaporative cooler provides a maximum cooling capacity of 502 W with a wet bulb effectiveness of 85%. As a dehumidification core and employing potassium formate as a liquid desiccant, the dehumidifier is capable of reducing the air relative humidity by 17% with an overall dehumidification capacity of 733 W and humidity effectiveness of 47%. Being cheap and simple to design with their attractive heat and mass transfer characteristics and the corresponding large surface area-to-volume ratio, hollow fiber membrane contactors provide a promising alternative for cooling and dehumidification applications. 相似文献
53.
Progress of the Indian economy is threatened by the impact of climate change. Generation of urban heat islands (UHIs), waning of urban green cover, increase in carbon emissions and air pollution deteriorate the living environment. Rise in urban temperatures and heat stress induced mortality remain major concerns. Although the National Action Plan on Climate Change emphasises the national missions of ‘enhanced energy efficiency’, and ‘green India’, little research has been devoted to explore the passive cooling potential of urban greenery in India, thus lending uniqueness to this study. The manifestations of unplanned urban development (UHIs, escalated carbon emissions, air pollution) are discussed and corroborated with identification of contributory factors. Contemporary greening practices and bye-laws in four major Indian cities (New Delhi, Pune, Chennai, and Visakhapatnam) are analysed and compared with global best practices. The findings are used to propose planning guidelines which are expected to assist in consolidating natural sustainability of emerging economies. 相似文献
54.
采用悬浮结晶法处理喹乙醇生产废液,考察了成冰率(冰晶融化后的体积占原水总体积的百分比)对废液COD、氨氮、TN和电导率去除效果的影响。在一级冷冻成冰率45%的条件下,经过三级冷冻处理后,三级出水的COD、氨氮、TN和电导率的去除率分别为99.4%、98.7%、98.5%和98.2%,一级浓缩液的COD、氨氮和TN的浓缩比分别为1.6、1.5和1.5;在一级冷冻成冰率80%的条件下,每一级出水的各项指标的去除率均有所下降,三级出水的COD、氨氮、TN和电导率的去除率分别为98.6%、98.3%、97.1%和95.9%,但一级浓缩液的浓缩比明显提高,COD、氨氮和TN的浓缩比分别为2.7、2.2和2.4。成冰率为80%时一级浓缩液的热值为7 449 J/g,在焚烧过程中可以依靠自身热量维持燃烧,不需要添加辅助燃料,减少焚烧处理的成本。 相似文献
55.
Detlef Hinneburg Eberhard Renner Ralf Wolke 《Environmental science and pollution research international》2009,16(1):25-35
Background, aim, and scope The fraction of ambient PM10 that is due to the formation of secondary inorganic particulate sulfate and nitrate from the emissions of two large, brown-coal-fired
power stations in Saxony (East Germany) is examined. The power stations are equipped with natural-draft cooling towers. The
flue gases are directly piped into the cooling towers, thereby receiving an additionally intensified uplift. The exhausted
gas-steam mixture contains the gases CO, CO2, NO, NO2, and SO2, the directly emitted primary particles, and additionally, an excess of ‘free’ sulfate ions in water solution, which, after
the desulfurization steps, remain non-neutralized by cations. The precursor gases NO2 and SO2 are capable of forming nitric and sulfuric acid by several pathways. The acids can be neutralized by ammonia and generate
secondary particulate matter by heterogeneous condensation on preexisting particles.
Materials and methods The simulations are performed by a nested and multi-scale application of the online-coupled model system LM-MUSCAT. The Local
Model (LM; recently renamed as COSMO) of the German Weather Service performs the meteorological processes, while the Multi-scale
Atmospheric Transport Model (MUSCAT) includes the transport, the gas phase chemistry, as well as the aerosol chemistry (thermodynamic
ammonium–sulfate–nitrate–water system). The highest horizontal resolution in the inner region of Saxony is 0.7 km. One summer
and one winter episode, each realizing 5 weeks of the year 2002, are simulated twice, with the cooling tower emissions switched
on and off, respectively. This procedure serves to identify the direct and indirect influences of the single plumes on the
formation and distribution of the secondary inorganic aerosols.
Results and conclusions Surface traces of the individual tower plumes can be located and distinguished, especially in the well-mixed boundary layer
in daytime. At night, the plumes are decoupled from the surface. In no case does the resulting contribution of the cooling
tower emissions to PM10 significantly exceed 15 μgm−3 at the surface. These extreme values are obtained in narrow plumes on intensive summer conditions, whereas different situations
with lower turbulence (night, winter) remain below this value. About 90% of the PM10 concentrations in the plumes are secondarily formed sulfate, mainly ammonium sulfate, and about 10% originate from the primarily
emitted particles. Under the assumptions made, ammonium nitrate plays a rather marginal role.
Recommendations and perspectives The analyzed results depend on the specific emission data of power plants with flue gas emissions piped through the cooling
towers. The emitted fraction of ‘free’ sulfate ions remaining in excess after the desulfurization steps plays an important
role at the formation of secondary aerosols and therefore has to be measured carefully. 相似文献
56.
鸟粪石结晶法回收垃圾渗滤液氨氮研究 总被引:7,自引:3,他引:4
采用MgSO4·7H2O和Na2HPO4·12H2O使NH3-N生成MgNH4PO4·6H2O(鸟粪石)结晶沉淀法回收渗滤液中NH3-N。考察了pH值、反应时间、药剂配比对NH3-N去除率的影响。结果表明,鸟粪石结晶回收NH3-N反应的适宜pH值为9~9.5之间,过高的pH会破坏鸟粪石晶体结构,导致固定氨从MgNH4PO4中游离出来,不利于氨氮的去除。在pH值为9.5、反应时间为25 min、Mg2+∶NH+4∶PO3-4=1.5∶1∶1.5的最佳条件下,渗滤液中NH3-N浓度由初始3 500 mg/L,经结晶沉淀后降低至175 mg/L,去除率达95%。鸟粪石结晶沉淀过程中几乎不吸收重金属,同时回收了氨氮,其沉淀产物鸟粪石是一种优良的缓释肥原料。 相似文献
57.
58.
MAP结晶法回收和去除尿液中的磷 总被引:8,自引:1,他引:7
以分解后的尿液为研究对象,采用MgCl2·6H2O 溶液作为MAP结晶剂,对MAP结晶同步回收尿液中的磷和部分氮的影响因素Mg/PO3-4-P摩尔比、反应pH、反应时间、沉淀时间和搅拌速度等进行小试试验.结果表明,Mg/PO3-4-P摩尔比是重要的运行参数,当其摩尔比超过1.3∶1时,磷的回收率超过95%,上清液剩余PO3-4-P浓度小于10 mg/L,而提高反应pH不能明显增加磷的回收率.该工艺的最佳运行条件为反应时间20 min,沉淀时间2.0 h,搅拌速度120 r/min,不需要pH调节控制.选择Mg/PO3-4-P摩尔比分别为1∶1、1.3∶1和1.5∶1,对在最佳条件下反应获得的3种产物采用SEM、XRD和ICP分析表明,3种产物都为比较纯净的MAP产品,其主要元素P、N、Mg的含量接近于MAP的理论含量(P=12.62%, N = 5.71%, Mg= 9.91%),分别为13.54%, 5.34%,9.01% (Mg/PO3-4-P =1∶1)、13.78%,5.23%,9.36% (Mg/PO3-4-P =1.3∶1)和13.34%,5.12%,9.15% (Mg/PO3-4-P=1.5∶1),具有较高的回收利用价值. 相似文献
59.
磁场对静态纳滤过程的膜通量及CaCO3结晶的影响 总被引:3,自引:0,他引:3
使用NF270型和NF型纳滤膜研究了经磁化预处理的钙溶液的静态纳滤过程,并与未经磁化预处理钙溶液的静态纳滤结果相比较.结果表明,当水样中Ca2+ 浓度为3.6 mmol/L,硬度等于碱度,初始水样体积为300 mL,体积浓缩倍数为2时,普通溶液的膜通量随滤出液体积呈现单调递减趋势;但处理磁化溶液时,膜通量随滤出液的体积先下降后上升,然后才下降,且平均膜通量比普通溶液的高,表明磁化预处理可以改善纳滤膜的部分操作性能.对膜的扫描电镜分析表明,处理磁化溶液的纳滤膜膜面上生成的晶体相对较多.综合纳滤膜通量和膜面晶体生成量的观察,认为磁场的引入可使膜表面结晶速率增加,致使膜面溶质浓度降低,通量上升,同时因生成的晶体全部留在膜面上,运行一段时间后有效膜面积减少,又导致通量下降.晶体生成量较多的膜,通量却相对较高,这与平常对膜污染的认识相矛盾.通过对结晶过程的理论分析,认为一定程度的结晶对膜操作性能有改善作用. 相似文献
60.
以模拟厌氧消化液为处理对象,进行了磷酸铵镁(MAP)结晶实验,考察了p H值、CO2-3、Ca2+以及CO2-3和Ca2+共存对磷酸铵镁结晶反应的影响;利用扫描电子显微镜(SEM-EDX)、X射线衍射(XRD)和傅里叶变换红外光谱(FTIR)对产物进行了表征.结果表明,随着p H值升高,磷的去除率显著提高,并在p H值为9.5时得到具有良好沉降性能的针状MAP晶体;CO2-3的存在会使磷去除率降低,在实验设定CO2-3浓度最大的条件下,磷去除率降低约17%,同时CO2-3会削弱Ca2+对MAP结晶反应的贡献,但并不改变MAP晶体形态和纯度;Ca2+存在则可以提高P去除率,但对MAP结晶反应抑制作用显著,当体系中n(Ca)/n(Mg)0.65,产物主要以无定形磷酸钙盐为主;在Ca2+与CO2-3共存的体系中,Ca2+可有效地消除CO2-3对除磷效果的影响,随着两者浓度的增加,产物Ca CO3含量增多,磷酸盐则主要以MAP形式沉淀. 相似文献