A new class of generalized quasi-variational inequalities with applications to Oseen problems under nonsmooth boundary conditions

In this paper, we study a generalized quasi-variational inequality(GQVI for short) with two multivalued operators and two bifunctions in a Banach space setting. A coupling of the Tychonov fixed point principle and the Katutani-Ky Fan theorem for multivalued maps is employed to prove a new existence theorem for the GQVI. We also study a nonlinear optimal control problem driven by the GQVI and give sufficient conditions ensuring the existence of an optimal control. Finally, we illustrate the appli...     

阴离子表面活性剂和β-环糊精包结作用

环糊精由于其特殊结构可与众多物质(客体分子)形成包结物,这种包结物在化学理论研究、化工工业、农业及医药等领域有广阔的应用前景[1、2],因而受到人们极大的关注.人们用电导法、核磁技术、表面张力法等研究了环糊精与阴离子表面活性剂的相互作用,但这些方法得出的结果很...     

Solar-driven CO2 conversion to methane and methanol using different nanostructured Cu2O-based catalysts modified with Au nanoparticles

This work describes the use of TiO₂ nanotubes-based electrodes(TNT) modified with Cu₂O nanostructures and gold nanoparticles for the photoelectroreduction of CO₂ to produce value-added compounds.A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator,due to its π-conjugated electron system.The highest production yield was achieved using a TNT@PDA/Nc/Au^40% electrode,with Faradaic efficiencies of 47.4%(110.5 μM c...     

在固定曲面上作平面纯滚动刚体的接触点加速度

用复合运动的方法推导了刚体在固定曲面上作平面纯滚动时接触点加速度的一般公式, 该方法较简便严谨.     

离子色谱法测定南京市道路灰尘中的四种无机阴离子

采用离子色谱法测定南京市道路灰尘中无机阴离子F^-、Cl^-、SO4^2-、NO3^-的含量。道路灰尘样品过150μm孔径的筛网,经3次涡旋离心提取,再取上清液高速离心,0.22μm滤膜过滤后上离子色谱测定。离心后的样品经IonPacTMAS 11-HC(250 mm×4 mm)色谱柱分离,以NaOH溶液(25 mmol/L)为淋洗液,采用电导检测器检测。4种阴离子均具有较宽的线性范围(0.01~0.20 mg/L),其线性相关系数r≥0.999。样品的加标回收率在87.4%~95.2%,仪器相对标准偏差(RSD)均≤3.5%,方法相对标准偏差(RSD)均≤7.7%。方法具有分析速度快,精密度好等优点,可用于评价南京市城区道路灰尘中的四种无机阴离子水平。     

含偶氮苯与噻吩结构单元的共轭聚合物合成及酸致变色性质

以1,3-二(二苯膦基)丙烷二氯化镍(Ⅱ)作催化剂[Ni(dpp)Cl2],通过2,5-二溴噻吩格式试剂与4,4′-二碘偶氮苯共聚得到了一种新型共轭聚合物.采用红外光谱、核磁共振氢谱对聚合物的结构进行表征并通过紫外-可见吸收光谱、荧光光谱、X-射线衍射、热失重分析(TGA)、差热分析(DTA)等测试手段对聚合物的性能进行了详细的研究.紫外可见光谱分析结果表明,聚合物在384 nm处显示了偶氮苯发色团的特征吸收峰,相对于单体红移34 nm.在聚合物的氯仿溶液中观察到酸致变色现象,即分别加入CF3COOH和CH3SO3H后,溶液颜色由黄色分别变成墨绿色和紫色,而加入三乙胺溶液后溶液恢复到初始颜色.在25℃下测得的特性粘数为0.53 dL/g.热失重分析结果显示,该聚合物具有较好的热稳定性.     

0.6Ca0.61La0.26TiO3-0.4La(Mg0.5Ti0.5)O3介质陶瓷微波烧结的晶粒生长动力学研究

采用微波烧结制备了0.6Ca0.61La0.26TiO3-0.4La(Mg0.5Ti0.5)O3[0.6CLT-0.4LMT]陶瓷,研究烧结工艺对其显微结构和晶粒生长行为的影响,并采用线性回归方法建立了Hillert模型和Sellars简化模型,采用非线性回归方法建立了具有时间指数的Sellars-Anelli模型.结果 表明,随着烧结温度的升高、保温时间越长,晶粒尺寸越大,且烧结温度对晶粒生长的影响更为明显.对三种模型预测的晶粒尺寸与实验结果的平均晶粒尺寸进行了误差分析,发现Hillert模型对该陶瓷的预测精度最低,Sellars-Anelli模型对该陶瓷的预测精度最高.由Sellars-Anelli模型得到的0.6CLT-0.4LMT陶瓷的晶粒生长动力学方程为d4.718=d04.718 +4.516×1033×t0.888×exp[-1 059 682/(RT)],能够有效预测0.6CLT-0.4LMT陶瓷微波烧结的晶粒生长过程.     

星际氧气分子的气相-尘埃模型研究

本文采用气相-尘埃模型Nautilus研究了星际氧气的演化过程,使用了两种典型初始丰度值下的恒温模型和变化物理条件下的加热模型进行模拟计算. 结果表明,在冷致密云的条件下,CO、O₂和H₂O达到峰值的时间依赖于氢核密度的多少,其随氢核密度的增大而减小. 在加热模型中,在温度升高后的10⁵年后,氧气的丰度值与观测结果符合较好. 在温度大于30 K后,氧气的稳态丰度值将不再随氢核密度而变化,且大于此温度可以阻止氧气大量的沉降到尘埃表面. 此外,无论在恒温模型还是在加热模型中,低氢核密度更有利于O₂的生成.     

Decomposition of multi-particle azimuthal correlations in Q-cumulant analysis

The method of Q-cumulants is a powerful tool for studying the fine details of azimuthal anisotropies in high energy nuclear collisions.This paper presents a new method,based on mathematical induction,to evaluate the analytical form of high-order Q-cumulants.The capability of this method is demonstrated via a toy model that uses the elliptic power distribution to simulate the anisotropic emission of particles,quantified in terms of Fourier flow harmonics v_n.The method can help in study...     

Learning to select the recombination operator for derivative-free optimization

Extensive studies on selecting recombination operators adaptively, namely, adaptive operator selection(AOS), during the search process of an evolutionary algorithm(EA), have shown that AOS is promising for improving EA’s performance. A variety of heuristic mechanisms for AOS have been proposed in recent decades, which usually contain two main components: the feature extraction and the policy setting. The feature extraction refers to as extracting relevant features from the information collected ...