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Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu Yan-Bo Li Qi Zhang Jun-Zhao Xiao yi-Fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian peng Liang yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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A dual-site Fe-based catalyst for efficient ammonia synthesis under mild conditions

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Science China Chemistry 2025年

作者： Shiyong Zhang Mingyuan Zhang Tianhua Zhang Jizhen sun Jiaxin Li Kailin Su Ruishao Mao Yanliang Zhou Xuanbei peng Yangyu Zhang Jun Ni Bingyu Lin Xiuyun Wang Lilong Jiang National Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou University Qingyuan Innovation Laboratory

Achieving green ammonia （NH3） synthesis requires developing effective catalysts under mild ***,the competitive adsorption of N2and H2,as well as the strong binding of N-containing intermediates on the catalyst,greatly inhibits the active sites for efficient ***,we constructed a series of ZrH2-modified Fe catalysts with dual active sites to address these issues and realized efficient NH3synthesis under mild *** study shows that ZrH2can not only provide active sites for H2activation but also transfer electrons to Fe sites for accelerating *** interaction between Fe and ZrH2over 40ZrH2-Fe leads to a decrease in work function and a downward shift of the d-band center,which is conducive to N2activation and NH3desorption,*** utilization of distinct sites for activating different reactants can avoid the competitive adsorption of N2and H2,leading to excellent NH3synthesis activity of the 40 wt.%ZrH2-mediated Fe *** a result,40ZrH2-Fe exhibits a high NH3synthesis rate of 23.3 mmol g-1cath-1at 400°C and 1 MPa and robust stability during100 h time-on-stream.

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Collusion-Proof Result Inference in Crowdsourcing

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Journal of Computer Science & Technology 2018年第2期33卷 351-365页

作者： peng-peng Chen Hai-Long sun yi-Li Fang Jin-peng Huai State Key Laboratory of Software Development Environment School of Computer Science and Engineering Beihang University Beijing 100191 China Beijing Advanced Innovation Center for Big Data and Brain Computing Beijing 100191 China

In traditional crowdsourcing, workers are expected to provide independent answers to tasks so as to ensure the diversity of answers. However, recent studies show that the crowd is not a collection of independent workers, but instead that workers communicate and collaborate with each other. To pursue more rewards with little effort, some workers may collude to provide repeated answers, which will damage the quality of the aggregated results. Nonetheless, there are few efforts considering the negative impact of collusion on result inference in crowdsourcing. In this paper, we are specially concerned with the Collusion-Proof result inference problem for general crowdsourcing tasks in public platforms. To that end, we design a metric, the worker performance change rate, to identify the colluded answers by computing the difference of the mean worker performance before and after removing the repeated answers. Then we incorporate the collusion detection result into existing result inference methods to guarantee the quality of the aggregated results even with the occurrence of collusion behaviors. With real-world and synthetic datasets, we conducted an extensive set of evaluations of our approach. The experimental results demonstrate the superiority of our approach in comparison with the state-of-the-art methods.

关键词： crowdsourcing quality control collusion collaborative crowdsourcing result inference

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Improving the Quality of Crowdsourced Image Labeling via LabelSimilarity

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Journal of Computer Science & Technology 2017年第5期32卷 877-889页

作者： yi-Li Fang Hai-Long sun peng-peng Chen Ting Deng State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China

Crowdsourcing is an effective method to obtain large databases of manually-labeled images, which is especially important for image understanding with supervised machine learning algorithms. However, for several kinds of tasks regarding image labeling, e.g., dog breed recognition, it is hard to achieve high-quality results. Therefore, further optimizing crowdsourcing workflow mainly involves task allocation and result inference. For task allocation, we design a two-round crowdsourcing framework, which contains a smart decision mechanism based on information entropy to determine whether to perform the second round task allocation. Regarding result inference, after quantifying the similarity of all labels, two graphical models are proposed to describe the labeling process and corresponding inference algorithms are designed to further improve the result quality of image labeling. Extensive experiments on real-world tasks in Crowdflower and synthesis datasets were conducted. The experimental results demonstrate the superiority of these methods in comparison with state-of-the-art methods.

关键词： image labeling crowdsourcing information entropy label similarity

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In situ polymerization of poly(3,4-ethylenedioxythiophene)protective layer towards stable zinc anode

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Nano Research 2025年第1期18卷 382-394页

作者： Debin Luo peng Zhou Xiaowei Lv Panpan sun Xiaohua sun Hewei Zhao College of Materials and Chemical Engineering Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion MaterialsChina Three Gorges UniversityYichang 443002China Hubei Three Gorges Laboratory Yichang 443007China School of Chemistry Beihang UniversityBeijing 100191China

Aqueous zinc-ion devices are considered promising candidates for energy storage due to their high safety,low cost and relatively high energy ***,the dendrite growth,hydrogen evolution reaction(HER)and corrosion of the zinc anode significantly limit the development of Zn-ion ***,an inexpensive poly(3,4-ethylenedioxythiophene)(PEDOT)protective layer was constructed in situ on the Zn surface using electropolymerization to suppress dendrite growth and side reactions,thereby enhancing the reversibility of *** and theoretical calculations revealed that this hydrophilic protective layer promotes the desolvation process of hydrated Zn^(2+)and facilitates the transport of zinc ions,thus improving the thermodynamic and kinetic properties of Zn^(2+)deposition and inhibiting interfacial side ***,the optimized PEDOT@Zn symmetric battery exhibited a cycling stability exceeding 1250 h at 0.5 mA·cm^(-2)and 0.25 mAh·cm^(-2),with a significantly reduced overpotential(from 91.8 to 35 mV).With the assistance of the PEDOT protective layer,the PEDOT@Zn//Cu battery maintained approximately 99.5%Coulombic efficiency after 450 ***-situ scanning electron microscopy(SEM)and in situ optical microscopy characterizations further confirmed that the PEDOT protective layer can effectively suppress the growth of zinc ***,the Zn-ion capacitors assembled by the PEDOT@Zn and activated carbon also demonstrated outstanding cycling stability.

关键词： zinc-ion devices zinc anode poly(3 4-ethylenedioxythiophene)(PEDOT) dendrite desolvation process

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Tailoring carbon chains for repairing graphite from spent lithium-ion battery toward closed-circuit recycling

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Journal of Energy Chemistry 2022年第9期31卷 97-107,I0004页

作者： Chenxing yi peng Ge Xiqing Wu Wei sun Yue Yang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina

Graphite, as a strategic mineral resource, the recycling from spent lithium-ion batteries(LIBs) has attracted considerable attention for meeting considerable economic value. However, closed-circuit recycling still suffers from the lack of effective repair methods. Considering the existing defects, a series of Cchain length carbons have been successfully introduced to repair spent graphite. Obviously, with the evolution of carbon resources, the thickness and pores of the coating layer were tailored with the functional groups. Benefitting from the increased active sites and created fold structure, their coulombic efficiency is obviously restored from 14% to 86.89%, while the stable capacity is kept at approximately 384.9 mAh gafter 100 cycles. Moreover, their excellent rate properties are kept about approximately 200 mAh gat2 C, meeting the standard of commercial materials. Supported by the detailed kinetic behaviors, the enhanced rate is mainly dominated by pseudocapacitive behaviors, accompanied by deepening redox reactions. Meanwhile, the cost of the proposed approach for recycling spent graphite is 894.87 $ t^(-1),and the recycling profit for regenerating graphite is approximately 7000 $ t^(-1). Given this, this work is anticipated to shed light on the closed-circuit recycling of spent graphite and offer significant strategies to repair graphite.

关键词： Spent lithium-ion battery Graphite Carbon coating Regeneration Kinetic behaviors

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绿色建筑材料的环保性能评估与应用前景

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城市建筑 2025年第1期22卷 202-204页

作者：孙毅山东省建筑材料工业设计研究院

文章以具体工程项目为例,探讨绿色建筑材料的应用优势,并通过绿色建筑材料在工程中的具体运用,评估材料的环保性能,同时探讨绿色建筑材料的应用前景,最后从不同角度出发,提出绿色建筑材料的发展对策。

关键词：绿色建筑材料环保性能评估应用前景

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基于生物质气化的绿色甲醇制备系统性能分析

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现代化工 2025年第1期45卷 232-238页

作者：李博孙昊陈衡王奕楠孙颖刘文毅华北电力大学能源动力与机械工程学院北京102206 国网智能电网研究院有限公司北京102211

为提升生物质制备甲醇的效率并减少碳排放,提出了一种基于生物质秸秆气化的绿色甲醇制备系统。该系统以生物质为碳源,利用碱性电解水制取绿氢,并形成调节合成气制备绿色甲醇。通过Aspen Plus模拟系统流程,结果表明,虽然电解水增加了厂... 详细信息

为提升生物质制备甲醇的效率并减少碳排放,提出了一种基于生物质秸秆气化的绿色甲醇制备系统。该系统以生物质为碳源,利用碱性电解水制取绿氢,并形成调节合成气制备绿色甲醇。通过Aspen Plus模拟系统流程,结果表明,虽然电解水增加了厂用耗电量,但新提出的系统在碳转化率和综合能源效率方面均得到显著提升,分别为65.41%和69.47%。系统的效率为67.26%,显示该系统对有效能的利用率较高。系统动态回收周期为8.62 a,净现值为210.11万美元,单位产品能耗量为4.07 MWh,且单位能耗二氧化碳排放量低至0.04 t/GJ,表明该系统在经济效益以及环境保护方面具有一定优势。

关键词：生物质气化绿色甲醇热力学性质数值模拟效益评估

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Secondary solar heat gain modelling of spectral-selective glazing based on dynamic solar radiation spectrum

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Building Simulation 2023年第12期16卷 2211-2224页

作者： peng Xue yi Shen Sheng Ye Jinqing peng Yanyun Zhang Qianqian Zhang Yuying sun Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology Beijing University of TechnologyBeijing 100124China Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China State Grid Zhongxing CO. LTDLvyuan BranchBeijing 100761China College of Civil Engineering Hunan UniversityChangsha 410082HunanChina Key Laboratory for New Functional Materials of Ministry of Education Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

The secondary solar heat gain,defined as the heat flows from glazing to indoor environment through longwave radiation and convection,grows with the increasing of glazing *** the rapid development and application of spectrally selective glazing,the secondary solar heat gain becomes the main way of glazing heat transfer and biggest proportion,and indicates it should not be simplified calculated ***,a dynamic secondary solar heat gain model is developed with electrochromic glazing system in this study,taking into account with three key aspects,namely,optical model,heat transfer model,and outdoor radiation *** with the traditional K-Sc model,this new model is verified by on-site experimental measurements with dynamic outdoor spectrum and *** verification results show that the root mean square errors of the interior and exterior glass surface temperature are 3.25°C and 3.33°C,respectively,and the relative error is less than 10.37%.The root mean square error of the secondary heat gain is 13.15 W/m2,and the dynamic maximum relative error is only 13.2%.The simulated and measured results have a good *** addition,the new model is further extended to reveal the variation characteristics of secondary solar heat gain under different application conditions(including orientations,locations,EC film thicknesses and weather conditions).In summary,based on the outdoor spectrum and window spectral characteristics,the new model can accurately calculate the increasing secondary solar heat gain in real time,caused by spectrally selective windows,and will provide a computational basis for the evaluation and development of spectrally selective glazing materials.

关键词： econdary solar heat gain spectral-selective glazing solar spectrum dynamic heat transfer

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A bio-inspired optical imaging method for robotic perception in turbid water

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Science China Technological Sciences 2025年第1期 79-81页

作者： Xudong sun Yafeng LI peng LIN Xiaodi SHANG Xianping FU School of Information Science and Technology Dalian Maritime University College of Computer Science and Technology Qingdao University

In the realm of underwater robotics, optical imaging plays a pivotal role in many scientific researches. Due to the effects of absorption and scattering,images captured in turbid water are severely degraded. Therefore, enhancing the quality of underwater optical images stands paramount in ensuring the continued advancement and efficacy of underwater robots across its multifarious applications.

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