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21.
以低廉的铜胺络合物为新型模板剂, 成功地合成了含铜的 SSZ-13 沸石分子筛 (Cu-ZJM-1). 在合成过程中, 铜胺络合物既是模板分子, 又是催化活性组分铜物种的直接来源. 理论计算表明, 该模板分子的构型与尺寸恰好与构成 SSZ-13 分子筛结构的 CHA 笼相匹配, 因而可以成功地导向该沸石分子筛结构. 采用 X 射线衍射、扫描电镜、氮气吸附、红外、紫外-可见吸收光谱、差热-热重分析、氨气程序升温脱附及氢气程序升温还原等手段对样品的性质及模板分子的状态进行了系统表征. 结果表明, 所制 Cu-ZJM-1 样品为结晶度很高的 SSZ-13 沸石结构, 硅铝比和铜负载量可调且铜处于高分散状态, 在 NH3 选择催化还原氮氧化物反应中表现出优异的催化性能.  相似文献   
22.
为实现波浪传播的高保真数值模拟,采用包含单元均值和点值(volume-average/point-value method,VPM)的有限体积法求解纳维-斯托克斯方程和具有二次曲面性质和高斯积分的双曲正切函数(THINC method with quadratic surface representation and Gaussian quadrature,THINC/QQ)方法来重构自由面,建立以开源求解库OpenFOAM底层函数库为基础的VPM-THINC/QQ模型. 在本模型中添加推板造波法实现波浪的产生功能,采用松弛法实现消波功能,构建高精度黏性流数值波浪水槽. 分别采用VPM-THINC/QQ模型和InterFoam求解器(OpenFOAM软件包中广泛使用的多相流求解器)开展规则波的数值模拟,重点探究网格大小和时间步长等因素对波浪传播过程的影响,定量地分析波高衰减程度;为验证本模型的适应性,对长短波进行模拟. 结果表明,在相同网格大小或时间步长条件下,VPM-THINC/QQ模型的预测结果与参考值吻合较好,波高衰减较少,且无相位差,在波浪传播过程的模拟中呈现出良好的保真性. 本文工作 为波浪传播的模拟研究提供了一种高精度的黏性数值波浪水槽模型.   相似文献   
23.
I.IntroductionLetflbeaboundeddomaininRs.D=flisadomainprovidingoilanda\D=Q=Dl(t)UQl(t)UF'.Waterandoilfillrespectivelyol(t)andD2(f).rfisafreeboundarydividedwaterfromoilandtheinitialpositionisatr',oD=r',aD=r1UF',oD,(t)=piUF',i==l,2.Supposewaterandoildon'tmix…  相似文献   
24.
Given the numerous industrial applications of zeolites as adsorbents, catalysts, and ion-exchangers, the development of new zeolite structures is highly desired to expand their practical applications. Currently, a general route to develop new zeolite structures is to use interlayer expansion agents to connect layered silicates. In this review, we briefly summarize the novel zeolite structures constructed from the lamellar precursor zeolites MWW, RUB-36, PREFER, Nu-6(1), COK-5, and PLS-1 via interlayer expansion. The contents of the summary contain detailed experiments, physicochemical characterizations, possible expansion mechanisms, and catalytic properties. In addition, the insertion of metal heteroatoms (such as Ti, Fe, Sn) into the layered zeolite precursor through interlayer expansion, which could be helpful to modify the catalytic function, is discussed.  相似文献   
25.
In this paper we discuss the properties of hysteresis phenomena and give some conclusions about two parabolic equations with hysteresis raised by A. Visintin.  相似文献   
26.
A goal for human society is to convert organic waste into valuable materials. Herein, 2‐(methylthio)‐bezothiazole (MTBT), an important organic waste in urban runoff, was catalytically converted into a series of organic semiconductors through carbon–sulfur bond activation. The efficient conversion of various substrates with different aromatic moieties and reacting functional groups (tin and boron) proved the generality of this novel diarylation Liebeskind–Srogl methodology. Moreover, the resulting organic semiconductors showed excellent performance in field effect transistors and cell imaging. This contribution presents an excellent example of converting organic waste into valuable materials and may open a new avenue to utilizing widely available aromatic thioethers.  相似文献   
27.
传统的信号检测算法在不确定的海洋环境中性能出现下降。基于贝叶斯原理的最优检测算法可以实现对不确定海洋环境中信号的有效检测,但是其突出问题是计算量较大。本文提出了一种基于主成分量分析的稳健信号检测器,该检测器利用贝叶斯原理将环境先验信息引入到检测算法中,同时使用主成分量分析方法来降低运算量,实现了对信号的快速有效检测。分别使用标准失配海洋模型和海上实测数据进行了计算机仿真和实验验证,结果表明:(1)基于主成分量的稳健信号检测器检测性能达到最优贝叶斯检测器的效果。(2)本文方法在线运算速度是贝叶斯最优检测器的5^一8倍。(3)环境先验信息失配的情况下,扩大海洋环境参数模型的不确定度范围有助于提高检测性能。  相似文献   
28.
In this work, the effects of photo‐induced defects on polymer solar cells (PSCs) based on the blends of poly (4,8‐bis‐alkyloxybenzo (1,2‐b:4,5‐b′) dithiophene‐2,6‐diyl‐alt‐(alkyl thieno(3,4‐b) thiophene‐2‐carboxylate)‐2,6‐diyl) (PBDTTT‐C) and [6,6]‐phenyl C70‐butyric acid methyl ester (PC70BM) are investigated. In addition to conventional PSC characterization approaches, the capacitance–voltage (C–V) response and the ideality factor are used to analyze the changes in the built‐in potential and defect‐induced recombination at the internal donor/acceptor interface and the electrode interfaces in illuminated PSCs. The results show that the dominant trap states increase with increasing illumination time, which indicates that photo‐induced defects play an important role in the photodegradation of inverted PSCs. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)  相似文献   
29.
Single-molecule devices,which are fabricated by the single molecule bridged through electrodes,provide a promising approach to investigate the intrinsic chemical or physical properties of individual molecules.Beyond the studies of single-molecule wires,a large number of responsive single-molecule junctions or devices with unique chemical or physical properties have been designed and fabricated by introducing the external field,which further offers the chance to explore conductive materials at the molecular level.Here,we summarized the latest studies on the behaviors of single-molecule devices based on the photon,thermal,electric,or magnetic responses,and discussed the development of responsive single-molecule devices in prospect.  相似文献   
30.
栾慧敏  雷驰  马野  吴勤明  朱龙凤  徐好  韩世超  朱秋艳  刘小龙  孟祥举  肖丰收 《催化学报》2021,42(4):563-570,中插5-中插12
高硅沸石具有优异的热稳定性、水热稳定性、大的微孔体积、高表面积和均匀的微孔孔道,因而广泛应用于催化领域.然而,高硅沸石的合成往往需要使用有机结构导向剂,不但增加了沸石合成成本,而且还产生了大量的三废排放.为了解决这个问题,我们发展了在无有机导向剂存在条件下采用沸石晶种诱导合成沸石的方法,但是该方法合成的沸石产物骨架富铝...  相似文献   
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