THE UPWIND FINITE DIFFERENCE FRACTIONAL STEPS METHOD FOR NONLINEAR COUPLED SYSTEM OF DYNAMICS OF FLUIDS IN POROUS MEDIA

For nonlinear coupled system of multilayer dynamics of fluids in porous media,the secondorder and first order upwind finite difference fractional steps schemes applicable to parallel arithmeticare put forward,and two-dimensional and three-dimensional schemes are used to form a completeset.Some techniques,such as calculus of variations,multiplicative commutation rule of differenceoperators,decomposition of high order difference operators and prior estimates,are adopted.Optimalorder estimates in L~2 norm are derived to determine the error in the second order approximate solution.This method has already been applied to the numerical simulation of migration-accumulation of oilresources.     

钨锡在花岗质硅酸盐熔体和共存含水流体间的分配实验研究

本文在进一步改进关键性实验技术的基础上,利用快速淬火高压釜系统成功地完成了四个系列的含水卤化物介质-花岗质岩浆体系中钨锡的流-熔分配实验。确定了一批钨锡流-熔分配系数;并建立了它们与卤化物摩尔浓度之间的线性关系式;分析了氯、钠、氟、钾对钨锡流-熔分配的影响;指出传统的钨锡岩浆期后热液成矿模式值得修正。     

云南腾冲热海热田中金和微量元素的分布特征

热海热田内热泉水和各类热水沉淀物中不同程度地富含Ａｕ、Ａｇ、Ａｓ、Ｓｂ、Ｈｇ、Ｔ１微量元素，金的富集与含黄铁矿的水热角砾岩、硅质泉华更为密切。热田内水热爆炸和沸腾作用广为发育，Ａｕ，Ａｇ、Ａｓ、Ｓｂ、Ｈｇ、Ｔ１微量元素组异常可能是热泉型金矿化浅部的地球化学特征。     

利用幂律液体压裂时水平裂缝几何尺寸的求解方法

本文提出了利用幂律液体压裂时求解水平裂缝几何尺寸的方法,分析了便于现场使用的图解法。应用实例说明,图版求解法使用简单、方便。     

金刚石压腔结合高速录像进行气–液体系中气相溶解、出溶动力学原位研究

利用水热金刚石压腔原位观测优势,结合显微镜高速录像技术,进行空气–H2O体系中气相溶解和出溶动力学实验研究.实验对金刚石压腔体系气泡生长、溶解过程进行原位实时记录,根据录像文件分解的照片来精确确定反应时间和温度,利用照片所记录的气泡半径随时间的变化来推算其体积生长参数和溶解程度.气–液相均一体系降温可促使气泡出溶,降温...     

水热法制备NaGd(WO_4)_2:Eu~(3+)发光材料

采用水热法,以十六烷基三甲基溴化铵(CTAB)为表面活性剂,合成了NaGd(WO4)2:Eu3+发光材料.采集XRD,SEM图谱来表征样品的晶型与形貌,利用激发光谱和发射光谱研究了材料的发光特性.结果表明,所制得的NaGd(WO4)2:Eu3+是由纳米棒组成的绒球状发光材料,球体直径为100nm,纳米棒长2～5μm.样品不仅可以被紫外光(266nm)激发,还能被近紫外光(393nm)和蓝光(464nm)有效激发,其主发射峰值位于614nm,为红色荧光成分,且当Eu3+掺杂物质的量分数为3%时,此发射峰达到最大,该发光粉可用于制造紫外光芯片激发的白光LED.     

周期性压力对T型微管内二元流体混合效果的影响

在微流动领域经常涉及到试剂的混合问题,但是在微设备中,雷诺数Re低,流体趋向于形成层流,很难发生有效的混合.通过对微管内流体施加周期性压力使流速随时间呈周期性变化可以有效促进微流动混合.运用格子Boltzmann方法模拟了T型微管内流体的流速随时间呈正弦曲线变化而导致的混沌现象.结果发现,混沌混合的效果取决于两流体流速的相位差、流速的变化周期和系统的雷诺数Re.     

塔北西部岩浆热液–地层水流体系统及碳酸盐岩储层的成岩作用响应

通过对塔北地区多个碳酸盐岩露头的深入研究,认为该区域碳酸盐岩依次经历了硅化→热液白云石化→方解石化3个主要的后期成岩作用改造。通过对包裹体、同位素及稀土元素地球化学的研究,发现硅化流体具有高温度、高盐度特征;热液白云石化流体具有相对基质白云石明显的Eu正异常以及更高的轻重REE的分异度,而对方解石化流体的平衡水的计算可知,δ18OSMOW主要分布在+5.5‰～+12‰区间内,与岩浆热液流体的同位素值相一致。综合分析认为,存在岩浆热液对塔北地区碳酸盐岩的后期成岩改造。此外,通过对各露头碳、氧、锶同位素等的分析发现,后期成岩流体具有复杂性和叠加性,存在有机碳的影响以及大气淡水、壳源富87Sr地层水的混溶。岩浆活动为热液循环提供了大量的热源,异常的热事件驱动成岩流体进行广泛的循环流动,对碳酸盐岩地层进行热液成岩改造,同时岩浆热液也为成岩流体提供了诸如Si,REE等物质组分。晶洞内大量石英、硬石膏的发现说明研究区域的碳酸盐岩经历了广泛的酸性溶蚀作用,具有岩浆活动背景的开启性断层发育带成为有利的勘探靶区。     

Preparing Ca-P coating on biodegradable magnesium alloy by hydrothermal method: In vitro degradation behavior

Magnesium alloys are potentially attractive biodegradable materials.However,their rapid corrosion rate limits their biomedical application.To slow down the rate of biodegradation,a protective calcium-phosphate coating was formed on a magnesium alloy substrate by a hydrothermal method.Scanning electron microscope results showed that the coating consisted of two layers with different crystalline characteristics.The loose outer layer showed a prism-like crystal structure,while the compact inner layer is a dense ultra-fine regular di-pyramid-like structure with an average grain dimension of ～200 nm.The compositions of the inner layer and outer layer were calcium-deficient hydroxyapatite (Ca-def HA) and dicalcium phosphate (DCPa),respectively.The coating adhered well to the substrate with a thickness of about 15 m.Immersion in Hank’s solution indicated that the coating could significantly improve the degradation properties of magnesium alloy.The pH of the solution containing the coated samples increased much more slowly than the untreated control.After 8 d immersion,the uncoated sample had corroded seriously while the coated sample was much less corroded.The Ca/P atom ratio in both the layers of the coating increased and the coating was still protecting the substrate.The two layers of the coating corroded differently because of differences in solubility.The outer layer was more severely attacked and many holes were formed on the surface,the inner layer suffered less attack.In addition,a growth of precipitate on the inner layer was observed,indicating that surface bioactivity was improved by the coating.Thus,magnesium alloys coated with a Ca-P coating prepared by a hydrothermal method are promising candidate biodegradable biomaterials,and further investigation of in vivo degradation behavior is suggested.