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Decarboxylative Amination with Nitroarenes via Synergistic Catalysis

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Chinese Journal of Chemistry 2024年第4期42卷 351-355页

作者： Meiling Ding Sitian Zhou Shunruo Yao Chengjian Zhu weipeng li Jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsChemistry and Biomedicine Innovation Center(ChemBIC)School of Chemistry and Chemical EngineeringNanjing UniversityNanjingJiangsu210023 China Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhouHenan450001 China

In this paper,we have developed a decarboxylative amination of carboxylic acids with nitroarenes for the synthesis of secondary amines.The protocol is performed at mild conditions without the use of noble metals as catalysts.A wide range of structurally diverse secondary amines could be obtained in good yields(up to 94%)with good functional group tolerance.This transformation shows good to excellent selectivity,avoiding the generation of over alkylated byproducts.

关键词： Nitroarenes Amines Synergistic catalysis Carboxylic acids Radical alkylation Amination Photocatalysis Steric hindrance

Cognitive impairment in cerebral small vessel disease induced by hypertension

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Neural Regeneration Research 2024年第7期19卷 1454-1462页

作者： weipeng Wei Denglei Ma lin li Lan Zhang Department of Pharmacy Xuanwu Hospital of Capital Medical UniversityBeijingChina Beijing Geriatric Medical Research Center Beijing Engineering Research Center for Nervous System DrugsNational Center for Neurological DisordersNational Clinical Research Center for Geriatric DiseasesBeijingChina

Hypertension is a primary risk factor for the progression of cognitive impairment caused by cerebral small vessel disease,the most common cerebrovascular disease.Howeve r,the causal relationship between hypertension and cerebral small vessel disease remains unclear.Hypertension has substantial negative impacts on brain health and is recognized as a risk factor for cerebrovascular disease.Chronic hypertension and lifestyle factors are associated with risks for stro ke and dementia,and cerebral small vessel disease can cause dementia and stroke.Hypertension is the main driver of cerebral small vessel disease,which changes the structure and function of cerebral vessels via various mechanisms and leads to lacunar infarction,leukoaraiosis,white matter lesions,and intracerebral hemorrhage,ultimately res ulting in cognitive decline and demonstrating that the brain is the to rget organ of hypertension.This review updates our understanding of the pathogenesis of hypertensioninduced cerebral small vessel disease and the res ulting changes in brain structure and function and declines in cognitive ability.We also discuss drugs to treat cerebral small vessel disease and cognitive impairment.

关键词： blood-brain barrier cerebral small vessel disease cognitive impairment dementia endothelial dysfunction enlarged perivascular space hypertension lacunar infarction neuroinflammation treatment white matter high signal intensity

Laser Wire Additive Manufacturing of Ti-6Al-4V Alloy and Its Machine Learning Study for Parameters Optimization(Invited)

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中国激光 2024年第4期51卷 182-198页

作者： Wu Junyi Zhang Bo Wang Weihua li weipeng Yao Xiyu Wang Dawei Xing Wei Yan Ming Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055GuangdongChina Songshan Lake Materials Laboratory Dongguan 523830GuangdongChina Institute of Physics Chinese Academy of SciencesBeijing 100190China Jiaxing Research Institute Southern University of Science and TechnologyShenzhen 518055GuangdongChina High Performance Computing Department National Supercomputing CenterShenzhen 518055GuangdongChina

Ti-6Al-4V is a benchmark Ti alloy. Laser wire additive manufacturing(LWAM) offers advanced manufacturing capability to the alloy for applications possibly including exploration of outer space. As a typical multiple-variable process, LWAM is complex, which, however, can be analyzed, predicated or even optimized by artificial intelligence(AI) methods such as machine learning(ML). In this study, printing parameters of the Ti-6Al-4V is firstly optimized using single-track-single-layer experiments, and then single-track-multiple-layer samples are printed, whose properties in terms of hardness and compressive strength are analyzed subsequently by both experiments and ML. The two ML approaches, artificial neural network(ANN) and support vector machine(SVM), are employed to predict the experimental results, whose coefficients of determination R2 show good values. Further optimized properties are realized by adopting genetic algorithm(GA) and simulated annealing(SA) approaches, which contribute to high mechanical properties achieved, for instance, an engineering compressive strength of about 1694 MPa. The results here indicate that important mechanical properties of the LWAM-prepared Ti alloys can be well predicted and enhanced using suitable ML approaches.

关键词： artificial printing additive

Corrosion Behavior of Graphene Nanosheets Reinforced Magnesium Matrix Composites in Simulated Body Fluids

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 525-536页

作者： liwen Chen Jianhui Jing Lulu Zhang Jing li weipeng Chen limin li Yuan Zhao Hua Hou Yuhong Zhao School of Materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy MaterialsNorth University of ChinaTaiyuan 030051China Shanxi Key Laboratory of Advanced Manufacturing Technology School of Mechanical EngineeringNorth University of ChinaTaiyuan 030051China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Magnesium(Mg)alloy is considered as a promising biodegradable implant material but restricted to rapid degradation.Here,the new strategies based on thixomolding process had been explored to utilize the outstanding anti-permeability of graphene nanosheets(GNPs)while inhibit its galvanic corrosion with the matrix,so as to improve the corrosion resistance of composites.The agglomerate of GNPs with 0.9 wt%content is the main reason for the deterioration of corrosion performance due to the formation of micro-galvanic corrosion.The grain refinement of composites with 0.6 wt%content had positive effects on the better corrosion resistance.After process adjusting,the unique distributions of GNPs along grain boundaries play a vital role in improving the corrosion resistance.It can be ascribed to the following mechanisms:(I)The barriers can be established between the Mg matrix and corrosive medium,hence blocking the charge transfer at the interface;(II)The GNPs can effectively promote apatite deposition on the Mg matrix,leading to form dense apatite layers and prevent the further invasion of SBF;(III)The GNPs acting as reinforcements exists in the corrosion layer and apatite layer,impede the apatite layer falling off from the Mg matrix.These findings broaden the horizon for biomedical applications in Mg matrix composites to realize desired performances.

关键词： Magnesium matrix composite Graphene nanosheets Corrosion resistance

Leaching kinetics of fluorine during the aluminum removal from spent li-ion battery cathode materials

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Journal of Environmental Sciences 2024年第4期138卷 312-325页

作者： Shengjie li Jianxin Zhu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

The high content of aluminum(Al)impurity in the recycled cathode powder seriously affects the extraction efficiency of Nickel,Cobalt,Manganese,and lithium resources and the actual commercial value of recycled materials,so Al removal is crucially important to conform to the industrial standard of spent li-ion battery cathode materials.In this work,we systematically investigated the leaching process and optimum conditions associated with Al removal from the cathode powder materials collected in a wet cathode-powder peeling and recycling production line of spent li-ion batteries(liBs).Moreover,we specifically studied the leaching of fluorine(F)synergistically happened along with the removal process of Al,which was not concerned about in other studies,but one of the key factors affecting pollution prevention in the recovery process.The mechanism of the whole process including the leaching of Al and F from the cathode powder was indicated by using NMR,FTIR,and XPS,and a defluoridation process was preliminarily investigated in this study.The leaching kinetics of Al could be successfully described by the shrinking core model,controlled by the diffusion process and the activation energy was 11.14 kJ/mol.While,the leaching of F was attributed to the dissolution of liPF6and decomposition of PVDF,and the kinetics associated was described by Avrami model.The interaction of Al and F is advantageous to realize the defluoridation to some degree.It is expected that our investigation will provide theoretical support for the large-scale recycling of spent liBs.

关键词： Al removal F leaching Cathode powder Heating alkali leaching Leaching kinetics

Two-point statistics of coherent structures in turbulent flow over riblet-mounted surfaces

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Acta Mechanica Sinica 2019年第3期35卷 457-471页

作者： weipeng li Hong liu School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Direct numerical simulations (DNS) of turbulent flow over a drag-reducing and a drag-increasing riblet configuration are performed. Three-dimensional two-point statistics are presented for the first time to quantify the interaction of the riblet surfaces with the coherent, energy-bearing eddy structures in the near-wall region. Results provide statistical evidence that the averaged organization of the streamwise vortices in the drag-reducing case is lifted above the riblet tip, while in the drag-increasing case the streamwise vortices are embedded further into the riblet cove. In the spanwise direction, the cores of the streamwise vortices over the riblet surfaces are shown to be closer to each other than those for flow over the smooth wall, and wider riblet spacing leads to more reduction on their spanwise distances. In the cases with riblets the streamwise vortices have longer streamwise lengths, but their inclination angles do not change much.

关键词： Turbulent drag reduction Riblets Coherent structures

Decarboxylative Acylation of Carboxylic Acids:Reaction Investigation and Mechanistic Study

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CCS Chemistry 2022年第7期4卷 2469-2480页

作者： Xiaopeng Wu Jie Han Siyu Xia weipeng li Chengjian Zhu Jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsChemistry and Biomedicine Innovation Center(ChemBIC)School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023 State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryShanghai 200032 Advanced Catalytic Engineering Research Center of the Ministry of Education Hunan UniversityChangsha 410082

Ketones serve as one of the most critical building blocks in organic synthesis,involving numerous functional group transformations.Herein,we rep ort an unprecedented photoredox-nickel metallap hotoredox-catalyzed decarboxylative acylation of common aliphatic acids with readily available aromatic and aliphatic thioesters.A wide range of structurally diverse asymmetrical aryl alkyl and dialkyl ketones have been constructed in yields of up to 98% with this strategy.The protocol has excellent reaction selectivity and functional group compatibility,representing a significant step forward in ketone synthesis.The one-pot decarboxylative acylation at the gram scale from two different carboxylic acids and the late-stage application for the synthesis of complex ketones shows its synthetic robustness.Both mechanistic experiments and density functional theory(DFT)calculations suggest that the decarboxylative acylation reaction operates via an underdeveloped Ni(Ⅰ)-Ni(Ⅱ)-Ni(Ⅰ)-Ni(Ⅲ)-Ni(Ⅰ)catalytic cycle.

关键词： metallaphotoredox decarboxylative acylation ketones synthesis dual-catalysis carboxylic acid

Additives strategies to improving cycling stability of li metal batteries by modifying electrode electrolyte interphases

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Progress in Natural Science:Materials International 2024年第2期34卷 338-344页

作者： Yuan li Pengfei Huang Chunyu Cui Xiaoyuan Ma li Chen Zekun li linhai li Yuhong Tian School of Biological and Chemical Engineering Guangxi University of Science and Technology School of College of Chemistry and Chemical Engineering Hunan University Isky Future Energy Institute

li metal batteries（LMBs） have attracted much attention due to the ultra-high theoretical capacity of the li metal anode（LMA）.However,the uncontrollable dendrites growth and low coulombic efficiency hinder their practical application.Here,we explore 3,5-difluoropyridine（2F-BD） as a novel electrolyte additive to enable highperformance LMBs.The 2F-BD additive participates in and modifies the solvation structure of li ions by reducing the coordinated number of PF6-at the electrode surface,leading to the formation of a liF and li3N-rich solid electrolyte interphase（SEI）.The liF component increases the robustness of SEI and suppresses the formation of li dendrites,while the li3N component facilitates the transportation and reaction kinetics of li ions.As a result,the li‖li symmetric cell presents a stable cycling performance of up to 500 h at a current density of 1 mA cm-2.After coupling with liFePO4cathode,the obtained full cell achieves high specific capacities of 106.06 mA h g-1and 84.98 mA h g-1at 2.55 mA cm-2and 5.10 mA cm-2,respectively,and maintains a high capacity retention of84.0% after 1000 cycles at 0.13 mA cm-2,with an average cycling CE of 99.58%.

关键词： Electrolyte additive li dendrites li metal batteries liF and li3N-Rich electrode-electrolyte interphase liFePO4 cathode

A Review of Terahertz Solid-state Electronic/Optoelectronic Devices and Communication Systems

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Chinese Journal of Electronics 2024年

作者： Wenbo li Hongxin ZENG lin HUANG Sen GONG Haoyi CAO weipeng WANG Zheng WANG Hongji ZHOU Shixiong liANG Ziqiang YANG Yaxin ZHANG University of Electronic Science and Technology of China Huzhou Key Laboratory of Terahertz Integrated Circuits and Systems Yangtze Delta Region Institute (Huzhou)University of Electronic Science and Technology of China Terahertz Institute Zhangjiang National Laboratory National Key Laboratory of Application Specific Integrated Circuit Hebei Semiconductor Research Institute

With the rapid development of modern communication technology, spectrum resources have become non-renewable and precious resources, and the terahertz frequency band has entered people's vision. Nowadays, terahertz communication technology has become one of the core technologies for future high-capacity and high-rate communication. This paper discusses and analyzes the core technologies related to the field of terahertz communication.We introduce the characteristics, domestic and international comparisons and development trends of the core devices for terahertz communication, and also introduce and discuss the terahertz solid-state frequency mixing communication system, terahertz direct modulation communication system, and terahertz optoelectronic communication system.Finally, we summarize the development of terahertz communication technology and the outlook of future applications.

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