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精准调控Baeyer-Villiger单加氧酶的底物选择性以避免拉唑亚砜的过氧化
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作者 吴殷琦 陈倩倩 +9 位作者 陈琦 耿强 张巧玉 郑宇璁 赵晨 张龑 周佳海 王斌举 许建和 郁惠蕾 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第8期157-167,共11页
氧化酶催化的分子功能化是非常具有吸引力的研究领域之一,其中,高度选择性氧化反应对手性分子的构建至关重要.大量研究集中在对氧化酶立体选择性和区域选择性的分子改造上,而由于底物选择性差引起的过度氧化问题长期被忽视.Baeyer-Villi... 氧化酶催化的分子功能化是非常具有吸引力的研究领域之一,其中,高度选择性氧化反应对手性分子的构建至关重要.大量研究集中在对氧化酶立体选择性和区域选择性的分子改造上,而由于底物选择性差引起的过度氧化问题长期被忽视.Baeyer-Villiger单加氧酶(BVMOs)是一类多功能的生物催化剂,可以在脂肪族或环状酮底物的羰基附近插入一个氧原子,具有较高的区域选择性.BVMOs还可以催化包括硫、氮和磷在内的杂原子的不对称氧化.由于其温和的反应条件和较好的对映选择性,BVMOs催化硫醚不对称氧化生成手性亚砜被认为是一种极具吸引力且绿色清洁的合成方法.BVMOs可以催化硫醚不对称氧化生成有价值的手性亚砜,但亚砜过氧化生成无用的副产物砜限制了其进一步应用.这种过度氧化的本质原因是BVMOs对底物选择性不足,导致目标产物亚砜被进一步氧化.本文建立了一个数学模型,将酶对硫醚和亚砜两种相似底物之间的特异性常数之比(kcat/Km)定义为酶对底物选择性.随后使用蛋白结构引导的底物通道工程方法精准调控了拉唑硫醚单加氧酶AcPSMO的底物选择性,成功地将亚砜的过氧化降至最低.酶促氧化奥美拉唑硫醚24h后,突变体F277L生成的副产物砜含量低于1%(mol/mol),而野生型的砜含量为65%.分子动力学模拟和量子力学/分子力学研究结果表明,黄素氢过氧化物(FADH-OOH)周围改变的氢键网络可以调节亚砜氧化的机制和活性.此外,重新设计的AcPSMO突变体也成功地应用于其它手性拉唑亚砜的可控合成.综上,本文开发的精确控制氧化酶底物选择性的方法对于提高其它杂原子生物氧化反应的底物特异性具有借鉴意义. 展开更多
关键词 Baeyer-Villiger单加氧酶 手性亚砜 过度氧化 底物选择性 蛋白质工程 分子动力学模拟 量子力学/分子力学研究
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理论设计和实验研究吡啶掺杂聚合氮化碳提升光催化CO_(2)还原性能
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作者 陈成成 刘芳庭 +3 位作者 张巧钰 张正国 刘琼 方晓明 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第3期91-102,共12页
光催化CO_(2)还原是利用太阳光和水将CO_(2)转化为高价值化学品或燃料(如CO、甲醇、甲烷等),被认为是解决CO_(2)问题的理想途径之一.CO_(2)分子中C=O离解能高而活化困难,且光催化CO_(2)还原涉及多质子耦合多电子转移过程且产物多样,因... 光催化CO_(2)还原是利用太阳光和水将CO_(2)转化为高价值化学品或燃料(如CO、甲醇、甲烷等),被认为是解决CO_(2)问题的理想途径之一.CO_(2)分子中C=O离解能高而活化困难,且光催化CO_(2)还原涉及多质子耦合多电子转移过程且产物多样,因而研制效率高且选择性好的光催化剂是该技术的关键.聚合物氮化碳(PCN)作为一种结构可调的有机光催化剂,具有化学稳定性好且能带位置适宜于还原CO_(2)的优势,是一种具有发展潜力的CO_(2)还原光催化剂;但是PCN也存在因其禁带宽度较大而对可见光响应范围有限以及因其结构由三均三嗪单元构成而缺乏足够活性位点来吸附和活化CO_(2)等不足.目前在提升PCN的光催化CO_(2)还原性能方面已有不少研究,但所得的PCN基光催化剂在效率和选择性上仍处于较低水平.考虑到光催化CO_(2)还原涉及复杂的热力学和动力学要求,对基于PCN的光催化剂进行精准设计和研究是非常必要的,这有望获得同时具有可见光吸收增强、光生载流子复合减少、吸附和活化CO_(2)的位点增加以及能带位置适宜等特性的高性能光催化剂.为此,本论文采用理论设计与实验研究相结合的方法,以吡啶掺杂PCN为模型,研制了一种用于CO_(2)还原的高性能PCN基光催化剂.本文设计了将吡啶掺杂到PCN结构单元中不同位置的两种结构,并运用理论计算确定其中禁带宽度较窄、更利于光生载流子分离、更有助于CO_(2)吸附和活化以及总能量较低的结构作为最优结构.然后,采用尿素与适量的2-氨基吡啶共聚的方法,制备了吡啶掺杂的PCN样品,并通过一系列表征确定结构设计成功.还测定了所得吡啶掺杂PCN样品的光学和光电化学特性,评价了它们光催化CO_(2)还原的活性和选择性.最后,通过理论计算和实验研究,阐明了该吡啶掺杂PCN光催化剂的性能增强机制及其光催化还原CO_(2)的反应路径.结果表明,以CO(bpy)_(2)为助催化剂,本文制备的吡啶掺杂PCN(CN-5%AP)光催化剂不仅取得了较高的CO产量,而且还获得99.6%的CO选择性,在λ=420 nm处的表观量子效率可达2.86%.研究表明,该吡啶掺杂的PCN光催化性能增强主要源于其提升的CO_(2)吸附容量以及对CO_(2)还原为CO反应的促进.综上,本工作为设计和制备实现高效CO_(2)还原的光催化剂提供了参考. 展开更多
关键词 光催化CO_(2)还原 先理论后实验 聚合氮化碳 密度泛函理论 吡啶
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Stretchable alkenamides terminated Ti_(3)C_(2)T_(x)MXenes to release strain for lattice-stable mixed-halide perovskite solar cells with suppressed halide segregation
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作者 Xuemei Yao Jialong Duan +7 位作者 Yuanyuan Zhao Junshuai zhang Qiyao Guo qiaoyu zhang Xiya Yang Yanyan Duan Peizhi Yang Qunwei Tang 《Carbon Energy》 SCIE EI CAS CSCD 2023年第12期21-30,共10页
Bandgap-tunable mixed-halide perovskite materials have attracted considerable interest because of their indispensability as top counterparts in tandem solar cells.However,the soft and disordered lattice always suffers... Bandgap-tunable mixed-halide perovskite materials have attracted considerable interest because of their indispensability as top counterparts in tandem solar cells.However,the soft and disordered lattice always suffers from severe phase segregation under illumination,which is particularly susceptible to residual lattice strain.Herein,we report a strain regulation strategy by using alkenamides terminated Ti_(3)C_(2)T_(x)MXenes as an additive into perovskite precursor.Apart from the role of a template for grain growth to obtain high-quality films,the stretchable alkyl chain promotes lattice shrinkage or expansion to form an elastic grain boundary to eliminate the spatially distributed stain and shut down ion migration channels.As a result,the all-inorganic perovskite solar cells based on CsPbIBr_(2)and CsPbI_(2)Br halides achieve prolonged device stability under harsh conditions and the best power conversion efficiencies up to 11.06%and 14.30%,respectively. 展开更多
关键词 all-inorganic perovskite solar cells defect passivation halide segregation stability strain relaxation
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Research on the Development of City Financial Systems under the Rural Revitalization Strategy 被引量:1
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作者 Jilu Liu qiaoyu zhang Xiaoming Zeng 《Journal of Contemporary Educational Research》 2021年第5期14-19,共6页
The implementation of the rural revitalization strategy can provide a better solution for problems such as the“three rural”development limitations and the imbalance of urban and rural economic development as it is t... The implementation of the rural revitalization strategy can provide a better solution for problems such as the“three rural”development limitations and the imbalance of urban and rural economic development as it is the key to comprehensive building of a well-off society.Based on Linhai City’s finance status,this article analyzes the financial needs of the city for a better economic development under the rural revitalization strategy which prioritizes the policy of building a city financial system.The city’s financial system should be organized in a multi-level stucture for better economic development.This will improve the credit system of villages and towns,strengthen agricultural product innovation financially,and improve the finances of rural residents. 展开更多
关键词 Rural revitalization City economy City financial system Linhai City
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Triplet-triplet annihilation upconversion materials as electrophoretic inks
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作者 qiaoyu zhang Guiwen Luo +5 位作者 Jinping Chen Tianjun Yu Rui Hu Guoqiang Yang Yi Zeng Yi Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第3期439-442,共4页
Luminescent materials that can be reversibly switched by electric field stimulation are attractive since the potential application for optoelectronic devices.Here we report a triplet-triplet annihilation upconversion(... Luminescent materials that can be reversibly switched by electric field stimulation are attractive since the potential application for optoelectronic devices.Here we report a triplet-triplet annihilation upconversion(TTA-UC)system with electrophoretic response which is developed as the electrophoretic ink.The TTA-UC system consists of an ionic derivative of 9,10-diphenyl anthracene(DPA)as the annihilator and Pt(II)octaethylporphyrin(PtOEP)as the sensitizer.Upon applying an electric field,migration and enrichment of positively charged DPA derivatives towards the cathode results in a 20%enhancement of TTA-UC.A quasi-solid film for electrically writing is made using the electrophoretic TTA system as the ink and a platinum electrode as a pen.The prototype of TTA-UC ink demonstrates unique luminescence functions upon electrically writing and erasing,providing a promising strategy to develop electronic devices for display,information storage and encryption. 展开更多
关键词 Triplet-triplet annihilation Photon upconversion ELECTROPHORESIS Electrophoretic ink Luminescence display
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溶液微晶提升全无机CsPbIBr_(2)钙钛矿的薄膜质量并减小碳基光伏器件内部载流子复合
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作者 闫福日 段加龙 +4 位作者 郭琪瑶 张乔宇 杨希娅 杨培志 唐群委 《Science China Materials》 SCIE EI CAS CSCD 2023年第2期485-492,共8页
钙钛矿前驱体溶液的胶体特性决定了钙钛矿薄膜的质量以及钙钛矿太阳能电池的光电转换效率.在本文中,我们通过简单地调控钙钛矿溶液的温度,实现了钙钛矿薄膜质量的优化.系统的表征测试表明,与室温下的钙钛矿前驱体溶液不同,在高温条件下... 钙钛矿前驱体溶液的胶体特性决定了钙钛矿薄膜的质量以及钙钛矿太阳能电池的光电转换效率.在本文中,我们通过简单地调控钙钛矿溶液的温度,实现了钙钛矿薄膜质量的优化.系统的表征测试表明,与室温下的钙钛矿前驱体溶液不同,在高温条件下,钙钛矿前驱体溶液中会产生尺寸在一微米以上的稳定微晶,能够促进钙钛矿中间相的自发成核并实现薄膜的择优生长.薄膜质量优化后,由于缺陷态减少和晶粒尺寸增加,光生电荷能够快速地在大晶粒内部传输,降低晶粒内部的非辐射复合以及辐射复合,将电池效率提升至11.12%,明显高于未优化器件的8.51%.更重要的是,优化器件表现出非常优异的空气稳定性和高温稳定性. 展开更多
关键词 薄膜质量 钙钛矿太阳能电池 钙钛矿薄膜 光电转换效率 空气稳定性 自发成核 电池效率 载流子复合
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Regulating^(*)COOH intermediate via amino alkylation engineering for exceptionally effective photocatalytic CO_(2) reduction
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作者 Chengcheng Chen qiaoyu zhang +3 位作者 Fangting Liu Zhengguo zhang Qiong Liu Xiaoming Fang 《Journal of Energy Chemistry》 SCIE EI CAS 2024年第5期282-291,共10页
Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate ... Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate and retarded desorption of target products.Engineering the interface microenvironment of catalysts has been proposed as a strategy to exert a significant influence on reaction outcomes,yet it remains a significant challenge.In this study,amino alkylation was successfully integrated into the melem unit of polymeric carbon nitrides(PCN),which could efficiently drive the photocatalytic CO_(2) reduction.Experimental characterization and theoretical calculations revealed that the introduction of amino alkylation lowers the energy barrier for CO_(2) reduction into^(*)COOH intermediate,transforming the adsorption of^(*)COOH intermediate from the endothermic to an exothermic process.Notably,the as-prepared materials demonstrated outstanding performance in photocatalytic CO_(2) reduction,yielding CO_(2)at a rate of 152.8μmol h^(-1) with a high selectivity of 95.4%and a quantum efficiency of 6.6%. 展开更多
关键词 Polymeric carbonnitride Regulate intermediate Photocatalytic CO_(2)reduction Amino alkylation ^(*)COOH adsorption
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