基于波动模态耦合的铝电解槽磁流体稳定性傅立叶级数法分析

铝电解槽内磁流体稳定性对铝电解生产有重要影响。本文结合铝电解槽实体仿真的电磁场计算结果,应用傅立叶级数法对槽内磁流体波动稳定性进行数值计算,并对波动的模态耦合问题进行了重点分析。在此基础上,本文以某320kA铝电解槽为研究载体分析了槽长宽比设计对磁流体稳定性的影响,结果表明:波动的不稳定分量集中分布在频谱图中重力波模态密集的低频区域;不考虑母线对体系的影响,增大槽的长宽比,有利于提高磁流体的稳定性。     

高比能LiFePO4的制备及性能研究

应用液相沉淀法-固相烧结法制备高密度的LiFePO4/C及纯相LiFePO4.X射线衍射、扫描电镜、傅立叶红外光谱仪、电化学性能测试表明:该样品具有单一的橄榄石结构和3.4 V左右的放电平台,掺碳的LiFe-PO4具有更优良的性能,粒度较小粒径分布均匀,振实密度达1.46 g/cm3,0.1C首次放电比容量为144.6mAh/g,循环20次后容量保持率为93.2%,1C倍率首次放电比容量为133.5 mAh/g,循环20次后容量下降8.76%.     

单点子域积分与多点子域积分

基于单点子域精细积分的思想,针对抛物线型热传导方程初边值问题,提出了多点子域积分的概念,推出了一种多点子域积分的FTCS格式。该格式为显格式,并证明其为无条件稳定。数值算例表明,多点子域积分的FTCS格式具有比单点子域积分的FTCS格式收敛速度快的特点。     

各向异性浮力紊流的显式代数应力模型及其验证

在Wallin & Johansson的显式代数雷诺应力模型(EARSM)基础上,引入浮力的紊动效应,使该模型能够反映浮力对紊流运动的影响.利用同位网格上的SIMPLEC算法,模拟了T-型连接管内的温度混合流动.与实验资料和DNS计算结果比较表明,提出的模型能够反映各向异性的浮力紊流特征,而且模型在计算进程中显示出良好的数值收敛性能,与涡粘性两方程模型的计算花费相当.     

Global existence of solutions of the critical semilinear wave equations with variable coefficients outside obstacles

In this paper, we consider the exterior problem of the critical semilinear wave equation in three space dimensions with variable coefficients and prove the global existence of smooth solutions. As in the constant coefficients case, we show that the energy cannot concentrate at any point (t, x) ∈ (0, ∞) ×Ω. For that purpose, following Ibrahim and Majdoub's paper in 2003, we use a geometric multiplier similar to the well-known Morawetz multiplier used in the constant coefficients case. We then use the compari...     

对称熵损失下成功概率p的E-Bayes估计

研究对称熵损失下成功概率p的Bayes估计和E-Bayes估计,证明了前者的存在性及唯一性.模拟结果表明E-Bayes估计优于极大似然估计和Bayes估计.并将E-Bayes方法应用在证券投资预测之中,预测效果较好.     

二维空间中半线性摄动波动方程初值问题解的渐近理论

研究二维空间中具初值问题的半线性波动方程解的渐近理论,在二次连续的古典空间中得到了形式近似解的渐近合理性在长时间范围内成立,这一结果描述了渐近解的长时间存在性.作为所得到的渐近理论的应用,对二维空间中的一个特殊波动方程作出了分析.     

初始点任意的一个非线性优化的广义梯度投影法

广义投影算法的优点是避免转轴运算。它成功地给出了线性约束问题、初始点任意的只带非线性不等式约束问题，以及利用辅助规划来处理带等式与不等式约束问题的算法．后者完满地解决了投影算法对于非线性等式约束问题的处理，但要求满足不等式约束的初始点．本文据此利用广义投影与罚函数技巧给出了一个初始点任意的等式与不等式约束问题的算法，省去了求初始解的计算，并保持了上述方法的优点，证明了算法的全局收敛性     

Cu2+离子A位取代对MgTiO3陶瓷结构及介电性能的影响

采用固相反应制备了Mg_1-xCu_x TiO₃(0.00≤x≤0.20)微波介电陶瓷,研究CuO烧结助剂对MgTiO₃陶瓷的微观结构和微波介电性能的影响。实验结果表明,CuO中的Cu²⁺离子会进入到MgTiO₃晶格中并取代Mg²⁺,形成Mg_1-xCu_x TiO₃固溶体。由于液相效应,适量的CuO可以促进MgTiO₃陶瓷的致密化烧结,降低其烧结温度。Cu²⁺离子的A位取代会改变样品的TiO₆八面体扭曲度。随着Cu²⁺离子含量的增加,会使MgTiO₃陶瓷的结构稳定性降低。随着CuO含量的增加,晶粒的不均匀生长和液相的出现导致样品的品质因数(Qf)下降。同时,Mg_1-xCu_x TiO₃陶瓷的相对密度、结构...     

Design,Synthesis, and Cytotoxic Activity of Novel Natural Arylsulfonamide-Inspired Molecules

Primary arylsulfonamide functional groups feature prominently in diverse pharmaceuticals. However, natural arylsulfonamides are relatively infrequent. In this work, two novel arylsulfonamide natural products were first synthesized, and then a series of novel molecules derived from natural arylsulfonamides were designed and synthesized, and their in vitro cytotoxic activities against A875, HepG2, and MARC145 cell lines were systematically evaluated. The results indicate that some of these arylsulfonamide derivatives exhibit significantly good cytotoxic activity against the tested cell lines compared with the control 5-fluorouracil (5-FU), such as compounds 10l, 10p, 10q, and 10r. In particular, the potential molecule 10q, containing a carbazole moiety, exhibited the highest inhibitory activity against all tested cell lines, with IC₅₀ values of 4.19 ± 0.78, 3.55 ± 0.63, and 2.95 ± 0.78 μg/mL, respectively. This will offer the potential to discover novel drug-like compounds from the sparsely populated area of natural products that can lead to effective anticancer agents.