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101.
心血管疾病越来越年轻化,尤其在驾车一族中比率逐年上升。因为开车时注意力高度集中,又缺乏运动,血液循环缓慢,所以驾车族已经成为心脏病的易感人群。  相似文献   
102.
本文以LEEMAN中阶梯光栅ICP光谱仪为倒,介绍了新一代中阶梯ICP扫描光谱仪的结构、原理、性能及其特点。同时介绍了ICP光谱仪在环境分析中的初步应用。  相似文献   
103.
The article investigated the adsorption of Hg(II) on Macrocystis pyrifera and Undaria pinnatifida in monometallic system and in the presence of Zn(II), Cd(II) and Ni(II).  相似文献   
104.
Moisture distributions in municipal sewage sludge, printing and dyeing sludge and paper mill sludge were experimentally studied based on four di erent methods, i.e., drying test, thermogravimetric-di erential thermal analysis (TG-DTA) test, thermogravimetricdi erential scanning calorimetry (TG-DSC) test and water activity test. The results indicated that the moistures in the mechanically dewatered sludges were interstitial water, surface water and bound water. The interstitial water accounted for more than 50% wet basis (wb) of the total moisture content. The bond strength of sludge moisture increased with decreasing moisture content, especially when the moisture content was lower than 50% wb. Furthermore, the comparison among the four di erent testing methods was presented. The drying test was advantaged by its ability to quantify free water, interstitial water, surface water and bound water; while TG-DSC test, TG-DTA test and water activity test were capable of determining the bond strength of moisture in sludge. It was found that the results from TG-DSC and TG-DTA test are more persuasive than water activity test.  相似文献   
105.
环球扫描     
《世界环境》2011,(6):6-6
珠峰冰川消融发出危险信号 越来越多的证据显示,气候变化正对喜马拉雅地区产生着巨大的影响,连海拔8000米以上的区域都难以幸免。科学家们在努力寻求切实可行的解决办法,以面对冰川融化带来的高海拔洪水灾害和威胁。珠穆朗玛峰南坡冰雪融化的迹象,或使登山者将来无冰攀登世界最高峰成为可能。  相似文献   
106.
环球扫描     
《世界环境》2011,(5):6-6
赫兹推动电动汽车租赁新潮流美国汽车租赁公司赫兹(Hertz)开始在中国提供电动汽车租赁业务,甚至同时提供司机。这一计划将在北京、上海和深圳三个城市推出,此举被看作是与中国先进汽车技术合作的标志。早在去年10月,赫兹就在纽约发起了其电动汽车的全球推广计划。在不到一年的时间里,已经在全球10个城市推出了电动汽车,并有多种品牌车型可供选择。作为全球最大的租车品牌,赫兹正致力于把电动汽车和插电式混合动力车推广到城市驾车  相似文献   
107.
《环境教育》2014,(6):21-23
随着全球经济化的迅速发展,世界上的不少国家都曾遭遇土壤污染的难题。这引起各国的高度重视。一些国家利用先进的技术与严格的法规进行生态治理,积累了大量经验,值得中国学习与借鉴。  相似文献   
108.
Ferric oxyhydroxide loaded anion exchanger (FOAE) hybrid adsorbent was prepared by loading nanosized ferric oxyhydroxide (FO) on anion exchanger resin for the removal of phosphate from wastewater. TEM and XRD analysis confirmed the existence of FO on FOAE. After FO loading, the adsorption capacity of the hybrid adsorbent increased from 38.70 to 51.52mg.g-1. Adsorption processes for both FOAE and anion resin were better fit to the pseudo first order model. Batch adsorption experiments revealed that higher temperature (313K), higher initial phosphate concentration (50 mg.L-1) and lower solution pH (pH value of 2) would be more propitious to phosphate adsorption. Competition effect of coexisting anions on phosphate removal can be concluded as sulfate 〉 nitrate 〉 chloride. Freundlich isotherm model can describe the adsorption of phosphate on FOAE more accurately, which indicated the heterogeneous adsorption occurred on the inner-surface of FOAE.  相似文献   
109.
A novel Ultrasonic Assisted Membrane Reduction (UAMR)-hydrothermal method was used to prepare flower-like Pt/CeO2 catalysts. The texture, physical/chemical properties, and reducibility of the flower-like Pt/CeO2 catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), N2 adsorption, and hydrogen temperature programmed reduction (HE-TPR) techniques. The catalytic performance of the catalysts for treating automobile emission was studied relative to samples prepared by the conventional wetness impregnation method. The Pt/CeO2 catalysts fabricated by this novel method showed high specific surface area and metal dispersion, excellent three-way catalytic activity, and good thermal stability. The strong interaction between the Pt nanoparticles and CeO2 improved the thermal stability. The Ce4+ ions were incorporated into the surfactant chains and the Pt nanoparticles were stabilized through an exchange reaction of the surface hydroxyl groups. The SEM results demonstrated that the Pt/CeO2 catalysts had a typical three-dimensional (3D) hierarchical porous struc- ture, which was favorable for surface reaction and enhanced the exposure degree of the Pt nanoparticles. In brief, the flower-like Pt/CeO2 catalysts prepared by UAMR-hydrothermal method exhibited a higher Pt metal dispersion, smaller particle size, better three-way catalytic activity, and improved thermal stability versus conven- tional materials.  相似文献   
110.
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