水助催化氢分子在金纳米粒子上解离的理论研究

金纳米粒子（GNPs）对氢分子（H2）的解离具有良好的催化活性.本文研究了水分子对GNPs催化H2解离的影响.对于H2在中性和带正电的金簇（Aunδ,n=3～5;δ=0,1）上的反应,考虑当水簇（（H2O）m,m=1,2,3,7）参与反应时GNPs催化H2的解离过程的热力学和动力学.研究结果表明,水对H2在GNPs上的解离有助催化的作用,且水簇大小不同,水助催化H2在金簇上解离的机理也有所不同,其由氢氢键的均裂解离转化为氧化解离.对两种机理所得的产物,作者计算了它们的Raman和IR光谱.国家自然科学基金项目(No.21373172,No.21533006,No.21621091);;国家科技部(No.2015CB932303);;固体物理化学国家重点实验室资

A Method for Assessing the Sustainability of Design in Developing World Projects

Projects for the developing world usually find themselves at the bottom of an engineer’s priority list. There is often very little engineering effort placed on creating new products for the poorest people in the world. This trend is beginning to change now as people begin to recognize the potential for these projects. Engineers are beginning to try and solve some of the direst issues in the developing world and many are having positive impacts. However, the conditions needed to support these projects can only be maintained in the short term. There is now a need for greater sustainability. Sustainability has a wide variety of definitions in both business and engineering. These concepts are analyzed and synthesized to develop a broad meaning of sustainability in the developing world. This primarily stems from the “triple bottom line” concept of economic, social, and environmental sustainability. Using this model and several international standards, this thesis develops a metric for guiding and evaluating the sustainability of engineering projects. The metric contains qualitative questions that investigate the sustainability of a project. It is used to assess several existing projects in order to determine flaws. Specifically, three projects seeking to deliver eyeglasses are analyzed for weaknesses to help define a new design approach for achieving better results. Using the metric as a guiding tool, teams designed two pieces of optometry equipment: one to cut lenses for eyeglasses and the other to diagnose refractive error, or prescription. These designs are created and prototyped in the developed and developing worlds in order to determine general feasibility. Although there is a recognized need for eventual design iterations, the whole project is evaluated using the developed metric and compared to the existing projects. Overall, the success demonstrates the improvements made to the long-term sustainability of the project resulting from the use of the sustainability metric

Promoting electrocatalytic CO2 reduction to formate via sulfur-boosting water activation on indium surfaces

一般认为，H2O还原析氢反应是CO2还原反应的竞争反应，若促进H2O活化将降低CO2还原反应的法拉第效率。因此，基于该认识设计出的高CO2还原法拉第效率的催化剂常常活性低。王野课题组打破这种认识，提出H2O分子活化在CO2还原中起着重要的作用，成功合成出硫修饰In催化剂来活化H2O分子而促进CO2还原制甲酸的新方法，该催化剂在非常宽的电流密度范围内（25~100 mA cm-2），均可以维持85%以上的甲酸法拉第效率。将硫拓展至硒和碲等其它硫族元素以及将金属铟拓展至铋和锡等其它p区金属，均实现很好的促进效果，表明通过促进水的活化来提高CO2电催化还原性能具有普适性。该工作为理性设计高效的CO2还原电催化剂提供了新策略。 该研究工作实验部分主要由王野、张庆红教授指导，能源材料化学协同创新中心iChEM2016级博士生马文超、固体表面物理化学国家重点实验室高级工程师谢顺吉（共同第一作者）完成；理论计算部分由吴德印教授指导，2015级博士生张霞光（共同第一作者）完成。醇醚酯国家工程实验室高级工程师康金灿参与了部分实验表征。上海光源姜政教授和孙凡飞博士为同步辐射表征提供了支持。【Abstract】Electrocatalytic reduction of CO2 to fuels and chemicals is one of the most attractive routes for CO2 utilization. Current catalysts suffer from low faradaic efficiency of a CO2-reduction product at high current density (or reaction rate). Here, we report that a sulfur-doped indium catalyst exhibits high faradaic efficiency of formate (>85%) in a broad range of current density (25–100 mA cm−2) for electrocatalytic CO2 reduction in aqueous media. The formation rate of formate reaches 1449 μmol h−1 cm−2 with 93% faradaic efficiency, the highest value reported to date. Our studies suggest that sulfur accelerates CO2 reduction by a unique mechanism. Sulfur enhances the activation of water, forming hydrogen species that can readily react with CO2 to produce formate. The promoting effect of chalcogen modifiers can be extended to other metal catalysts. This work offers a simple and useful strategy for designing both active and selective electrocatalysts for CO2This work was supported by the National Key Research and Development Program of the Ministry of Science and Technology of China (No. 2017YFB0602201), the National Natural Science Foundation of China (Nos. 21690082, 91545203, and 21503176). We thank staff at the BL14W1 beamline of the Shanghai Synchrotron Radiation Facilities (SSRF) for assistance with the EXAFS measurements. 研究工作得到科技部重点研发计划（批准号：2017YFB0602201）和国家自然科学基金（批准号：21690082、91545203、21503176）等项目的资助

In situ Raman spectroscopic evidence for oxygen reduction reaction intermediates at platinum single crystal surfaces

铂基催化剂表面的氧还原反应（ORR）是燃料电池重最重要的阴极反应。虽然经过几十年的研究，ORR的具体反应路径并没有真正解析清楚。在本研究中，李剑锋教授课题组首次利用其发展的电化学壳层隔绝纳米粒子增强拉曼光谱（SHINERS）技术原位研究了Pt(hkl)单晶表面的ORR反应过程，成功捕获到在1150 cm-1、1080 cm-1和732 cm-1区域O2-、OH*和HO2*等重要反应中间物种的直接拉曼光谱证据，并通过相应的同位素取代实验（氘和O-18同位素实验）及DFT理论模拟确认了中间物种的谱峰归属和吸附构型。总的来说，该项研究首次在Pt(hkl)单晶表面原位获得ORR反应重要中间物种的直接拉曼光谱证据，提出合理的ORR反应路径，加深了人们对ORR反应机理的认识，也为其他界面催化反应机理的研究提供了一条可行的研究思路。 该研究工作由校内外多个课题组共同努力完成，化学化工学院李剑锋教授课题组负责相关电化学原位拉曼光谱实验，Alicante大学Juan Feliu教授课题组负责单晶电化学实验，化学化工学院吴德印教授课题组负责DFT理论模拟，物理系杨志林教授课题组负责3D-FDTD的理论模拟。该研究工作的第一作者董金超和第二作者张霞光分别为化学化工学院2014级博士生（已毕业）和2015级博士生。【Abstract】Developing an understanding of structure-activity relationships and reaction mechanisms of catalytic processes is critical to the successful design of highly efficient catalysts. As a fundamental reaction in fuel cells, elucidation of the oxygen reduction reaction (ORR) mechanism at Pt(hkl) surfaces has remained a significant challenge for researchers. Here, we employ in situ electrochemical surface-enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculation techniques to examine the ORR process at Pt(hkl) surfaces. Direct spectroscopic evidences for ORR intermediates indicates that under acid conditions, the pathway of ORR at Pt(111) occurs through the formation of HO2, while at Pt(110) and Pt(100) it occurs via the generation of OH*. However, we propose that the pathway of ORR under alkaline conditions at Pt(hkl) surfaces mainly occurs through the formation of O2- . Significantly, these results demonstrate that the SERS technique offers an effective and reliable way for real-time investigation of catalytic processes at atomically flat surfaces.This work was supported by the NSFC (21522508, 21427813, 21521004, 21533006, 21621091,and 21775127), "111" Project (B16029 and B17027), Natural Science Foundation of Guangdong Province (2016A030308012), the Fundamental Research Funds for the Central Universities (20720180037), and the Thousand Youth Talents Plan of China. Support from MINECO and Generalitat Valenciana (Spain), through projects CTQ2016-76221-P (AEI/FEDER, UE) and PROMETEOII/2014/013 respectively, is greatly acknowledged. V.B.M thankfully acknowledges to MINECO the award of a pre-doctoral grant (BES-2014-068176, project CTQ2013-44803-P). 该研究工作得到国家自然科学基金委（21522508、21427813、21521004、21533006、21621091和21775127）的大力资助和支持。化学化工学院周志有教授、程俊教授，材料学院张华副教授，英国利物浦大学Gary Attard教授，以及化学化工学院苏敏、王耀辉、卢邦安等博士生和杨晓冬博士对本课题的研究给予了大力的支持和帮助

鱼类杂交不亲和性的研究

本文分析研究了鲮鱼属间杂交和亲本自交的胚胎发育时序和热量要求、胚后发育的形态特征、以及胚胎染色体组等方面的差异;并讨论了这些差异与各种杂交不亲和表现之间的相关性。明确地指出,决定鱼类杂交不亲和性的主要因素是亲本间核型的差异和核质间的矛盾程度。双亲的核型差异较大时,杂交胚胎往往在发育中途夭亡而成活率极低,甚至完全得不到仔鱼。核型相同或相似的亲本,其杂交子代的成活率一般甚高;但也可能与核型著异较大的组合一样,因核、质基因组表达的模式或调控机制等存在着差异,以及它们对外界环境条件的要求有矛盾,乃使胚后发育的速

mPEG-PLGA多孔微球的制备及其对降钙素的吸附行为

以聚乙二醇聚(乳酸乙醇酸)共聚物(mPEG-PLGA)为材料,采用溶剂挥发法与快速膜乳化法制备了尺寸均一的mPEG-PLGA多孔微球,用其吸附降钙素,考察了降钙素浓度、吸附时间、离子浓度、温度及pH值及微球性质对吸附的影响.结果表明,优化的吸附条件为:降钙素浓度1.0 mg/mL,pH 7.4,NaCl浓度0.2 mol/L,14℃下吸附8 h,该条件下,微球吸附量为48.9 mg/g;吸附量与微球比表面积正相关

mPEG-PLGA多孔微球的制备及其对降钙素的吸附行为

以聚乙二醇聚(乳酸乙醇酸)共聚物(mPEG-PLGA)为材料,采用溶剂挥发法与快速膜乳化法制备了尺寸均一的mPEG-PLGA多孔微球,用其吸附降钙素,考察了降钙素浓度、吸附时间、离子浓度、温度及pH值及微球性质对吸附的影响.结果表明,优化的吸附条件为:降钙素浓度1.0 mg/mL,pH 7.4,NaCl浓度0.2 mol/L,14℃下吸附8 h,该条件下,微球吸附量为48.9 mg/g;吸附量与微球比表面积正相关

快速膜乳化法制备尺寸均一PELA多孔微球及其孔径调控

采用快速膜乳化法,以二氯甲烷为油相,通过溶剂挥发制孔,在室温下制备了一系列聚乙二醇聚乳酸共聚物(PELA)多孔微球.结果表明,优化的制备条件为:搅拌速度250r/min、油相中PELA浓度50g/L、水/二氯甲烷/PVA水溶液体积比1:2.5:25及mPEG:PLA分子量比1:14,在该条件下可制备粒径均一、尺寸可控的PELA多孔微球,且孔径较大,孔径最大为15.0nm,属介孔材料,可用于蛋白多肽类药物的吸附

光MDPSK通用调制解调结构构建及仿真

新型相位调制格式技术能够有效地减少光传输损伤,是光传输系统中的重要技术。从理论上分析了光MDPSK（M进制差分相移键控）的调制解调原理,构建了通用的调制解调结构,并首次推导出MDPSK的通式和解调公式,最后以基于CSRZ（载波抑制归零,占空比为67%）码的DQPSK（差分正交相移键控）、8DPSK（3阶差分相移键控）和16DPSK（4阶差分相移键控）为例,用MATLAB软件仿真得到了其调制后的频谱图和解调后的眼图。仿真结果表明,随着级数的增加,MDPSK调制格式的频谱宽度会逐渐变窄,且解调后的眼图也令人满意