160 research outputs found

    Solvent-induced Intramolecular Charge Transfer in D-σ-A Dyads and Triads with Narrow HOMO-LUMO Gaps: A Theoretical Investigation

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    由强电子给体与强电子受体基团通过饱和s桥键连而成的D-s-A型二对物及A-s-D-s-A型三对物分子化合物,极易受环境因素的诱导发生分子内的电荷/电子转移(ICT),而表现出双稳态。该特性为分子水平上设计和制作多功能的有机分子材料提供了极大可能性,已成为新型分子器件的研究热点。针对这类可能具有双稳态特性的桥连二对物与三对物分子,本文基于现有的理论溶剂模型,采用量子化学计算,系统地研究了一系列基于TTF(TTF=trathiafulvalene)为电子给体的D-s-A型二对物及A-s-D-s-A型三对物分子的电子结构性质,以及溶剂对这类化合物电子态及相关性质的影响。具体结果总结如下:一、对于强电...The molecular D-s-A dyads and A-s-D-s-A triads, containing a strong electron-donor (D) and an electron-acceptor (A) linked by a saturated covalent , have narrow HOMO-LUMO gaps and readily undergo intramolecular charge/ transfer (ICT) upon various external stimulations and exhibit bistability as well as fascinating phenomena, e.g., solvatochromism. Accordingly, they are promising building blocks o...学位:理学博士院系专业:化学化工学院化学系_物理化学学号:1912005140307

    コミュニケーション ハ デザインシテ ナラナイ

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    Power Allocation Algorithm Minimizing Outage Probability in Cognitive Radio Relay Network

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    为提升认知无线中继网络的中断性能,通过分析系统中断概率及用户功率分配情况,提出一种最小化中断概率的功率分配算法。给出在主用户干扰约束和总功率约束; 条件下最小化中断概率的数学优化方程组,根据用户的最大发射功率与干扰电平阈值的受限关系,分别考虑分配功率不超过干扰电平阈值、中继节点功率受限于干扰; 电平阈值以及所有节点受限于干扰电平阈值这3种情况,对应提出3种最佳功率分配方案,并基于KKT条件求解最优值。实验结果表明,该功率分配算法与基于频; 谱共享以及基于机会主义中继选择的中断概率分析方法相比,性能增益提升显著,并且在总功率、干扰电平变化的条件下,所采用的功率分配方案提升系统中断性能; 效果较好。To improve the outage performance of cognitive radio relay network,this; paper proposes a power allocation algorithm minimizing outage; probability by analyzing the system outage probability and user power; allocation conditions. It presents the mathematical optimization; equations minimizing outage probability of under master user; interference constraint and total power constraint. Then, according to; the relationship between the user's maximum transmit power and; interference level threshold,it proposes three optimal power allocation; schemes respectively to deal with three types of cases,including the; distribution of power not exceeding the interference level threshold,the; relay node power limited by the interference level threshold,and all; nodes limited by the interference level threshold. Finally,the optimal; value is solved based on Karush-Kuhn-Tucker(KKT) conditions.; Experimental results show that compared with similar power allocation; methods,the proposed algorithm has obvious performance gain promotion.; And the effectiveness of the adopted power allocation schemes is proved; the most effective in enhancing the system outage performance when the; total power or the interference level is changing.国家自然科学基金; 闽南师范大学教学研究基

    思行善政、教书育人——通识教育课在新工科建设中的教改研究与创新实践

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    深化教育教学改革、创新思政教育工作,将知识技能传授、素质能力培养与学生理想、价值、道德、信念有机结合,是中国特色社会主义新时代对\"新工科\"人才培养工作提出的全新挑战。通识教育作为\"课程思政\"建设的排头兵,肩负着打开局面、示范指引的重要作用。通过对通识教育课程思政的教改研究与创新实践,有助于推动高等院校形成\"三全育人\"新氛围,开创\"新工科\"人才培养新方式,树立\"思行善政、教书育人\"新模式,为打造以实践能力养成和社会主义核心价值观形成为核心的创新性人才的培养奠定基础

    压汞法在氧化铝陶瓷膜制备中的应用

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    用压汞法测定非对称氧化铝(Al2O3)陶瓷膜从原料粉到支撑体和成品膜制备过程中各阶段样品的孔径及其分布、孔隙率和密度等参数,并与扫描电子显微镜(SEM)的结果进行比较。研究表明,用压汞法测定原料粉体粒子间的孔的孔径及其分布与支撑体中孔的孔径及其分布一致,其最可几孔径与理论计算结果接近,因此可以通过压汞法测定原料粉粒子间的孔的孔径及其分布来预测陶瓷膜支撑体的孔径及其分布。用压汞法测定非对称Al2O3陶瓷膜,可以直观地看出膜中多孔支撑体、过渡层和分离层各层的孔径及其分布。结合SEM的测试结果,压汞法对陶瓷膜生产过程中各样品的孔径及其分布、孔隙率、体积密度等进行了量化,合理解释了陶瓷膜生产中结构与性能的变化规律,可以用于指导陶瓷膜的生产

    密封条件对压汞仪分析测试的影响

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    在压汞仪样品室的密封中用硅橡胶垫片取代传统的真空油脂,考察了这两种密封法对压汞仪低压注汞时抽真空时间、空样品池注汞质量和对多孔SiO2标准样品测试结果的影响。研究显示,用硅橡胶垫片密封不仅不影响样品的测试速度和测量准确度,而且具有操作简便、能重复使用、不污染样品等优点。另外,由于硅橡胶垫片的厚度和直径可控,每次注入的汞质量相对稳定,有利于提高样品体积、孔隙率、表观密度和真密度的测量准确度和精度

    粒子增强PAN支撑膜的研究

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    对无机粒子填充的PAn渗透蒸发支撑膜进行了初步的研究。考察了不同填充量和填充体系及拉伸热定型的后处理工艺对膜通量和粘弹性的影响。结果表明,不同填充量和填充体系对膜通量及粘弹性的影响不明显;而拉伸和热定型的后处理工艺条件对膜通量和粘弹性有较大的影响。随拉伸比的提高,膜通量迅速增大,膜的稳定性变好,具有很好的耐热性,而膜的截流率却几乎不变。此外,还就膜的耐热机理进行了初步探

    Electrochemical Behavior of Irreversibly Adsorbed Sb on Au Electrode

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    用电化学循环伏安法和电化学石英晶体微天平(EQCM)技术研究了Sb在Au电极上不可逆吸附的电化学过程.研究结果表明,在-0.25V到0.18V(vs SCE)范围内,Sb可在Au电极上稳定吸附,并且在0.15V附近出现特征氧化还原峰.根据EQCM实验数据,在电位0.18V时,Sb在Au电极上的氧化产物是Sb2O3;同时Sb的吸附阻止了电解液中阴离子和水在Au电极上的吸附.当电极电位超过0.20V时,Sb2O3会被进一步氧化成Sb5+化合物,同时逐渐从Au电极表面脱附.The electrochemical processes of irreversibly adsorbed antimony (Sbad) on Au electrode were investigated by cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM). CV data showed that Sbad on Au electrode yielded oxidation and reduction features at about 0.15 V (vs saturated calomel electrode, SCE). EQCM data indicated that Sbad species were stable on Au electrode in the potential region from-0.25 to 0.18 V (vs SCE);the adsorption of Sb inhibited the adsorption of water and anion on Au electrode at low electrode potentials. Sb2O3 species was suggested to form on the Au electrode at 0.18 V. At a potential higher than 0.20 V the Sb2O3 species could be further oxidized to Sb(V) oxidation state and then desorbed from Au electrode.国家自然科学基金(20673091,20433060
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