MATHEMATICAL PROBLEMS ON THE FLUID-SOLUTE-HEAT FLOW THROUGH POROUS MEDIA Ⅰ. UNSATURATED CASE

A degenerate parabolic system arising from the fluid-solute-heat flow through unsaturatedporous media is considered. The existence of weak solutions to the initial boundary value problemof this system is esteblished by parabolic regularizaton. The regularity is proved as well, i. e. theweak solutions satisfy the equations and initial boundary conditions pointwise in the region wherethe moisture content is positive.     

THE BOUNDARY VALUE PROBLEMS FOR THE FILTRATION EQUATION IN PARTIALLY SATURATED POROUS MEDIA

In this paper we considered the first and the second boundary value problems for one-dimensionalfiltration in partially saturated porous media.The existence,uniqueness and regularity of weaksolutions were obtained.We also studied the interface problems and discussed the asymptotic behaviorof weak solutions.     

电感耦合等离子体原子发射光谱法测定烧结增效剂中三氧化二硼和二氧化锰

提出了电感耦合等离子体原子发射光谱法测定烧结增效剂中主成分三氧化二硼和二氧化锰含量的方法。用盐酸-硝酸混合溶液溶解样品,选择波长257.610,249.773 nm两条谱线分别作为测定硼和锰的分析线,采用背景校正来扣除干扰。方法用于烧结增效剂样品分析,测定结果与化学法测定值相一致。     

气相色谱-串联质谱法同时测定化妆品中的10种挥发性亚硝胺

建立了同时测定化妆品中10种挥发性亚硝胺(N-亚硝基二甲基胺,N-亚硝基二乙基胺、N-亚硝基二正丙基胺、N-亚硝基吗啉、N-亚硝基毗咯烷、N-亚硝基哌啶,N-亚硝基二正丁基胺、N-亚硝基二苯基胺、N-亚硝基二环己基胺及N-亚硝基二苄基胺)的气相色谱-串联质谱分析方法.膏霜、水剂、散粉、香波、唇膏等不同类型的化妆品样品分...     

锂离子电池用复合导电剂浆料制备与性能

采用超声波混合、抽滤的方法把多壁碳纳米管(MWCNTs)和乙炔黑混合制备了锂离子电池用复合导电剂浆料,用扫描电子显微镜(SEM)和恒流充放电测试考察了复合导电剂的结构和其作为导电剂对LiCoO2电极放电比容量的影响.SEM的分析结果表明MWCNTs和乙炔黑实现了纳米层次的均匀混合.复合导电剂悬浮液和浆料分别被用作导电剂制成了两种LiCoO2电极,前一种电极为Cathode A,后一种电极为Cathode B,考察了不同MWCNTs含量时,两种电极0.5 C第10次放电比容量的差异.实验结果表明,随着MWCNTs含量的增加,两种电极放电比容量的差值增大,说明低含量MWCNTs的复合导电剂浆料是一种理想的锂离子电池导电剂.     

MATHEMATICAL PROBLEMS ON THE FLUID-SOLUTE-HEAT FLOW THROUGH POROUS MEDIA Ⅱ. PARTIALLY SATURATED CASE

A degenerate parabolic system arising from the fluid-solute-heat flow through partiallysaturated porous media is considered. The existence of weak solutions to the initial boundary valueproblem of this system is established by time discretization, and the continuity of the weak solutionsis discussed.     

AN ELLIPTIC-PARABOLIC SYSTEM ARISING FROM THE FLUID-SOLITE-HEAT FLOW THROUGH SATURATED POROUS MEDIA

In this paper an elliptic-parabolic coupled system arising from the fluid-solute-heat flowthrough a saturated porous medium is considerd.The uniqueness and the existence of classicalsolutions are proved.The asymptotic behavior of solutions for large time is shown,too.     

RF excited diffusively cooled all-metal slab waveguide CO_2 laser

In this paper, a new type of radio frequency (RF) excited diffusively cooled all-metal slab waveguide CO2 laser is presented, in which the waveguide channel is constructed by two aluminum side walls and two aluminum electrodes, the discharge is confined in the slab waveguide channel in terms of the voltage division structure. From this type of structure, 127-W laser power is obtained.     

甜茶叶中甜茶苷的UPLC-MS/MS分析

采用超高效液相色谱-质谱联用法测定广西特产甜茶叶中的主要甜味成分甜茶苷的含量.样品经前处理后以Acquity UPLC BEH C18柱为色谱柱,流动相为乙腈(含体积分数为0.1％甲酸)-蒸馏水(含体积分数0.1％甲酸),梯度条件为10min乙腈相体积由20％变化到65％,柱温35℃,进样量5μL,流速为0.15mL/...     

关于有限群子群的弱S-可补性

设G是一个有限群,H是G的一个子群.称H为G的一个s-置换子群,若对于G的任意Sylow子群P,成立HP=PH.称H为G的一个弱s-可补的子群.若存在G的一个子群T,使得G=HT且H∩T≤H_s G,其中H_s G是包含在H中的G的最大的s-置换子群.本文在假设G的某些子群是弱s-可补的前提下,得到了G的一个结构定理,并推广了许多近期的结果.