表面活性剂强化空气扰动修复氯苯污染含水层     

秦传玉  赵勇胜  郑苇 《地球科学》2011,36(4):761-764

通过一维砂柱实验研究了阴离子表面活性剂十二烷基苯磺酸钠(SDBS)对空气扰动技术(air sparging,AS)修复氯苯污染地下水的强化效果.结果表明,SDBS的加入降低了地下水的表面张力,减小了水气两相毛细压力,从而提高了地下水中的空气饱和度.当曝气量为100 mL/min,地下水的表面张力由72.2 mN/m降至49.5 mN/m时,地下水中空气饱和度由13.2%提高至50.1%,而后随着表面张力的进一步降低,空气饱和度不再提高,反而有小幅下降.通过污染物的去除实验发现,SDBS的加入大大提高了氯苯的去除率,且去除率的变化与空气饱和度的变化趋势基本相符.因此,表面活性剂的加入可以作为空气扰动技术一种十分有效的强化手段.   相似文献   

Nutrient compositions of cultured Skeletonema costatum,Chaetoceros curvisetus,and Thalassiosira nordenskildii     

潘胜军  沈志良  刘文萍  韩笑天  苗辉  马海青 《中国海洋湖沼学报》2010,(6)

We cultured different-sized fractions of dominant phytoplankton species,Skeletonema costatum,Chaetoceros curvisetus,and Thalassiosira nordenski ldii,collected in different sea areas in various seasons,and measured and compared their C,N,P,Si contents.The N content of these species is similar,while the C,P,and Si contents of S.costatum from eutrophic Changjiang (Yangtze River) estuary are higher than those from Jiaozhou Bay (JZB),particularly the content of Si.The C,N,P,and Si contents of cultured phytoplank...  相似文献   

利用液态磷渣制备乳浊玻璃     

舒杼  周俊  王焰新  卢学实 《地球科学》2009,34(6):1019-1024

为实现炼磷排放的高温液态磷渣的热能、物质的同步回收利用, 并消除其环境污染问题, 通过现场试验, 以高温液态磷渣为主要原料, 直接与16.5%的石英粉和8.5%的高岭土热配合, 再经1450℃熔炼、浇铸成型和850℃乳化热处理, 制得了乳浊玻璃板材.磷渣乳浊玻璃的抗折强度为43.68MPa, 耐酸性为0.51%, 耐碱性为0.04%, 能满足建筑装饰材料的质量要求.ESEM、XRD和EDS分析结果共同表明, 母玻璃的乳浊机理在于主体玻璃中析出了富Ca元素的粒径为0.1~0.4μm的非晶质球形颗粒.由于高温液态磷渣掺量高达75%, 改性剂掺量低且成本低廉, 生产线易于配置, 本研究具有较高的工业化生产可行性、较佳的经济效益和应用前景.   相似文献   

Protection of bridge piers against scouring with tetrahedral frames     

Yee-Meng CHIEW 《国际泥沙研究》2009,24(4):385-399

Armoring countermeasures, such as riprap stones, are the primary method used to protect bridge piers against scouring; however, these methods have not had definitive success. Recently, flow-altering countermeasures, such as sacrificial piles, have been tested as an alternative to armoring countermeasures. This study investigated the mechanics of an innovative flow-altering countermeasure device, frames in the shape of tetrahedrons that act as a pier-scour countermeasure. Results of measured characteristics for turbulence flow showed that the flow around the tetrahedral frames can be divided into three regions： （1） a deceleration region near the sediment bed; （2） an acceleration region in the middle of water depth region; and （3） a restoration region near the water surface. The velocity magnitudes, turbulent intensities and vorticities decreased in the deceleration region, increased in the acceleration region and reverted to that of the unprotected condition in the restoration region. This pier-scour countermeasure is innovative because of its ability to dissipate energy associated with the downflow and the horseshoes vortex generated around the bridge pier. The scour tests revealed that the frames protected the foundation of bridge piers against scour. The experimental results showed that the percentage reduction of scour depth decreased as the velocity ratio, U/U c , decreased, reaching a value of 50% for the range of parameters tested in this study. Moreover, its efficiency was dependent on the placement density of the frames. The data showed that the frames were more effective when η was larger. However, their influence becomes less significant when η≥ 0.16.  相似文献   

Brief Introduction of Journals Sponsored by CAREERI     

Sciences in Cold  Arid Regions 《寒旱区科学》2009,1(3):0286-0286

  相似文献   

Brief Introduction of Journals Sponsored by CAREERI     

Sciences in Cold  Arid Regions 《寒旱区科学》2009,1(2):0192-0192

  相似文献   

西北地区东部冰雹云的卫星光谱特征和遥感监测模型   总被引：11，自引：0，他引：11  

张杰  张强  康凤琴  何金梅 《高原气象》2004,23(6):743-748

根据气象台站的冰雹观测记录,针对冰雹灾害多发的西北地区东部,选取2001—2004年间14次NOAA卫星过境的AVHRR资料,共88个样本数,对冰雹云和其他云的光谱特征进行对比分析。结果表明,雹云的热红外亮度温度的变化基本在245K以下,中红外波段反射率相对较低,基本变化在0.4及以下范围,可见光和近红外波段反射率>0.6。冰雹产生的两个重要条件是高的云光学厚度和大的云粒子有效半径共同发生的区域;西北地区冰雹发生的云顶高度基本在4.5～7km之间。根据雹云的光谱特征,确定雹暴指数及其模型阈值>0.35的冰雹监测方法,多普勒雷达回波和气象站观测结果说明,雹暴指数等多参数结合判别冰雹云效果显著。  相似文献   

NOAA卫星沙尘暴光谱特征分析及信息提取研究   总被引：12，自引：5，他引：7  

郭铌  倾继祖 《高原气象》2004,23(5):643-647,i001,i002

通过对2000—2002年多次沙尘暴过程NOAA卫星AVHRR资料的分析,研究了沙尘、云、沙漠、戈壁、积雪、裸地、植被等不同目标物的光谱特性,发现沙尘暴在AVHRR-2中各通道均有不同程度的反映。1,2通道中沙尘的反射率较高(介于云和沙漠之间);4,5通道的亮温低于晴空地表高于云;在3通道中沙尘表现的很独特,其亮度温度为所有研究目标物中最高的,表明通道3包含较多的沙尘信息,AVHRR-3取代AVHRR-2后对监测沙尘有不利影响。在此基础上提出定量提取沙尘信息的两种沙尘判识指数,并利用沙尘判识指数成功地提取多次沙尘暴过程的沙尘信息。结果表明：利用多通道组合沙尘判识指数能够对沙尘信息进行有效提取。  相似文献   

Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring     

YUE Ping      NIU ShengJie  HU YinQiao & ZHANG Qiang Key Laboratory of Arid Climate Change  Reducing Disaster of Gansu Province  Key Laboratory of Arid Climate Change  Reducing Disaster of CMA 《中国科学:地球科学(英文版)》2010,(5)

Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2008 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mo...  相似文献   

Fast and dynamic generation of linear octrees for geological bodies under hardware acceleration     

DENG Hao    ZHANG LiQiang  MAO XianCheng  MA JingTao  KANG ZhiZhong  PENG JunHuan  RUI XiaoPing & LIU Liu State Key Laboratory of Remote Sensing Science  Beijing Normal University  Beijing  China  School of Geoscience  Environmental Engineering  Central South University  Changsha  PTV America  Inc. Broadway Plaza Ste  Tacoma  WA  USA 《中国科学:地球科学(英文版)》2010,(1)

In the application of 3D Geoscience Modeling,we often need to generate the volumetric representations of geological bodies from their surface representations.Linear octree,as an efficient and easily operated volumetric model,is widely used in 3D Geoscience Modeling.This paper proposes an algorithm for fast and dynamic generation of linear octrees of geological bodies from their surface models under hardware acceleration.The Z-buffers are used to determine the attributes of octants and voxels in a fast way,a...  相似文献