Micromechanics of saturated and unsaturated porous media

The homogenization method is used to determine the formulation of the behaviour of both saturated and unsaturated porous media. This approach makes it possible to assess the validity of the effective stress concept as a function of the properties of the porous media at the microscopic scale. Furthermore, the influence of the morphologies of the solid and fluid phases on the macroscopic behaviour is studied. The strain induced by drying is examined as a function of the morphological properties. Copyright © 2002 John Wiley & Sons, Ltd.     

重组鲑鱼降钙素结肠黏附缓释微球的制备

为考察重组(酵母)鲑鱼降钙素结肠黏附缓释微球的制备工艺和最优处方,并对释药特性进行探讨。以阿拉伯胶、β-环糊精、可溶性淀粉、明胶为壁材,HPMC和卡波姆为生物黏附剂,运用正交试验确定喷雾干燥法制备微球的最佳工艺条件和处方。结果表明,微球的最佳制备工艺和处方为β-环糊精与阿拉伯胶以15∶1、HPMC与CP以4∶1配比为理想壁材,喷雾干燥进风温度160℃、进料速度10mL·min-1、雾化压力0.5MPa、壁材浓度15%、芯材比1∶3为最佳组合,所得微球能达到缓释12h的试验设计要求。本法工艺稳定、可行,所得鲑鱼降钙素结肠黏附缓释微球具有良好的缓释效果。     

Determation method for water content of diesel contaminated soil

With the increasing researches on geotechnical properties of the diesel contaminated soil （ DCS）, the water content measured is indispensable part during the early period. In this study, the relative error of water content measurement using the traditional method is as high as 20.78%, which is no longer suitable for contaminated soil. Through a series of tests to measure the loss coefficient of diesel in the drying time, the authors finally proposed a modified calculation formula for test samples. The results show that the maximum relative error calculated by using the modified formula is 0.96% , far lower than that of traditional formula, which can pro- vide accurate data for further study of diesel contaminated soil.     

贵州省织金县四方井岩溶大泉断流原因浅析

本文通过对织金县城四方井岩溶大泉系统的岩溶发育规律、水文地质特征、地下水动力条件进行调查分析,认为织金县四方井岩溶大泉的突然断流与2010年西南特大干旱造成区域地下水位的急剧下降及位于主径流带上的高层建筑深基坑施工产生的动荷载导致的塌陷体堵塞地下水径流通道有着密切联系。     

气流式雾化器结构的改进

气流式雾化器常存在产品颗粒粗,水分高等问题,因而影响产品质量。根据某工厂生产操作数据,对气流式雾化器性能进行了校核计算。根据计算结果,分析了影响产品质量的原因,并对气流式雾化器的结构进行改造。经改造后的雾化器,产品细度、所含水分等有所降低。     

环境磁学样品干燥过程中的磁性效应

对长江口南岸潮滩沉积物柱样和表层样品的烘干、风干和冻干法处理,然后进行系统磁性测量和水分、有机质的测定。实验结果得知:以冻干法为参照,烘干和风干方法对样品的磁参数的稳定性影响很小,但研究质地粘重样品时,应避免采用风干方法或校正风干样含水量质量后计算相关的磁参数。有机质的含量与主要磁参数成正相关,它对磁参数的影响很小     

膨胀土干湿循环胀缩裂隙演化的CT试验研究

对南阳重塑膨胀土在干湿循环过程中裂隙的演化进行了CT试验研究，试样的CT图像显示了原有裂隙开展，新裂隙产生，裂缝数量增加并连通，最后形成裂隙网络的过程。定义了基于CT数据的裂隙损伤变量，分析了裂隙损伤变量随累计干缩体变的变化规律。     

关于我国北方干旱化及其转折性变化

过去半个世纪,中国经历了北方的"西湿东干"和东部的"南涝北旱"的降水分布格局。近十几年来,这种降水长期变化的分布格局是维持还是发生了变化?针对这个问题,本文基于年降水观测数据、自矫正的帕尔默干旱指数scPDSI、地表湿润指数SWI及GRACE（Gravity Recovery and Climate Experiment）卫星数据反演的陆地水储量（TWS）对中国区域干旱化问题进行了再分析。结果表明,近16年（2001~2016年）,中国东部地区（100°E以东）"南涝北旱"的格局正在发生显著的变化,长江上中游及江淮流域已转为显著的干旱化趋势,而华北地区的降水已转为增加趋势,东部"南旱北涝"的格局基本形成;北方过去的"西湿东干"也转变为"西干东湿"的空间分布特征。显然,中国区域的降水格局在2001年后发生了明显的年代尺度转折性变化,两种常用干旱指数scPDSI和SWI的分析也证明了这一点。但GRACE的陆地水储量（TWS）的分析却显示,最近16年来,中国东部"南涝北旱"的格局仍未发生变化,北方大部分地区仍然处于干旱化的时段,且有加剧的趋势,其原因有待于进一步研究。     

深海鲣鱼(Katsuwonus pelamis)低温热泵联合干燥技术优化及品质分析

为了提高深海鲣鱼(Katsuwonus pelamis)干制品的质量,采用低温热泵联合干燥技术,对深海鲣鱼干制品的色差值、复水比、细菌总数、T-VBN值以及能耗值等指标进行分析测定。实验结果表明,低温热泵联合干燥技术较传统单一干燥技术在干燥效果、干燥能耗以及投入设备成本等方面更具有优势。进一步对影响低温热泵干燥技术的因素主要包括填物料量、循环风速、干燥室温度和相对湿度等进行优化。研究结果表明:深海鲣鱼(500g左右)在干燥室相对湿度控制35%、干燥室温度为45°C、装填物料量为8kg、循环风速为2.5m/s时候干燥效果最佳,并且节能效果明显,能耗降低达到35.2%。该成果的成功开发对降低水产品干燥过程中的耗能问题具有促进作用。     

Selected aspects of studies of sediments from the Ebro River （Spain） and the Dobczyce drinking water reservoir （Poland） within the frames of the European and national research projects

Mineral and organic matter either soluble or suspended are transported by the rivers and when deposited in the bed of the river or in the water reservoir, sediments are formed, whose chemical composition may serve as a fingerprint of the history of the ecosystem. The results of the studies of sediments in water systems （river catchments, reservoirs） can be used not only for the evaluation of the current state of the ecosystem but also to prevent any dangerous environmental changes. Bottom sediments can in many ways accumulate both suspended and soluble components. The process is influenced by several factors like pH, red-ox potential, oxygen content, interactions, etc. The complexity of those phenomena causes that in order to study the accumulation processes of compounds in sediments the application of various analytical techniques is required. The authors participate in two big projects on sediment studies. The AquaTerra Project is the EU funded project on understanding river-sediment-soil-groundwater interactions for support of management of river basins and catchment areas. Our group＇s studies are focused on mercury determination and its speciation in sediments and fish from the Ebro River in Spain. The Dobczyce Project is the national project funded by the Ministry of Education and sciences of Poland which is also a EU member country. The latter covers many aspects of accumulation and fate processes of chemical compounds in sediments of the reservoir which supplies 60% of drinking water to about one million population in the city of Krakow in Poland.