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Metallaphotoredox-Catalyzed Three-Component Couplings for Practical Synthesis of Ureas and Carbamates

Chinese Journal of Chemistry 2024年第3期42卷 264-270页

作者： Ernest Koranteng Zhen-Cao Shu Yi-yin Liu Qian Yang bin shi Qiang-Xian Wu Fen Tan Liang-Qiu Lu Wen-Jing Xiao Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction Ministry of EducationCollege of ChemistryCentral China Normal University152 Luoyu RoadWuhanHubei430079 China Wuhan Youji Industries Co. LtdNo.1 2nd Chemical Rd.WuhanHubei430082 China Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients School of Chemistry and Life SciencesHubei University of EducationWuhanHubei430205 China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhouGansu730000 China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan453007 China Wuhan Institute of Photochemistry and Technology WuhanHubei430082 China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai200032 China

Ureas are widely used in drugs,materials and catalysts because of their diamide structure,which can form strong hydrogen ***,it is of great scientific significance to develop efficient and green methods for the synthesis of urea compounds,especially unsymmetrical ***,we have disclosed novel and highly efficient three-component coupling reactions of organic halides,sodium cyanate and amines enabled by nickel/photoredox dual catalysis for the preparation of unsymmetrical *** reaction features simple and safe operations,broad substrate scopes,and product *** allows the facile synthesis of N-aryl/vinyl ureas from readily available,user-friendly feedstocks under mild conditions(27 examples,36%—98%yields).In addition,this method is further derived to alcohols as nucleophiles to synthesize a series of carbamates(15 examples,40%—95%yields).The mechanism experiment shows that the isocyanate produced by the coupling of halide and sodium cyanate may be the key intermediate in this reaction.

关键词： Cross-coupling Nickel Photoredox catalysis Three-component reaction Ureas Carbamates

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Flashover Characteristics of Dry Band-water band on Hydrophobic Surfaces

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 392-400页

作者： Xiaohan Wu Fanghui yin bin Cao Daiming Yang shichao Shao Liming Wang Tsinghua-Berkeley Shenzhen Institute(TBSI) Shenzhen 518055China Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China Shenzhen Polytechnic School Shenzhen 518055China

Due to their outstanding anti-flashover characteristics,composite insulators have been extensively applied in power systems.A lot of research has investigated flashover characteristics of hydrophobic specimens with artificial water ***,the phenomenon is not consistent with that of the contaminated composite *** the test specimens covered with water droplets,there is no obvious leakage current before the flashover and no obvious relationship between flashover voltage and the conductivity of water *** the contaminated composite insulator surface,there are short continuous arcs on the insulators before critical flashover,making insulators look like a luminous *** that under these two conditions,the proportion of water along the insulation distance is different,the flashover characteristic of“dry band-water band”on a hydrophobicity surface is analyzed in the present *** influence of the water band parameter(including length,width,and conductivity)as well as the length of dry band is *** this basis,the arc generation and development process of the surface covered with“dry band-water band”is *** research results improve the understanding of the flashover process on contaminated composite insulators.

关键词： Flashover characteristics hydrophobicity partial arc water band

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X-ray-activated Bi^(3+)/Pr^(3+)co-doped LiYGeO_4 phosphor with UV and NIR dual-emissive persistent luminescence

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Journal of Rare Earths 2024年第5期42卷 955-961,I0005页

作者： Xianggui yin Hongyun Zhong Lin Liu Junpeng shi Xia Sun Yun Zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen361021China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China

X-ray-activated luminescence materials have broad application prospects in photodynamic therapy of deep *** them,X-ray-activated persistent luminescence materials(PLMs)exhibiting multiple emission peaks have drawn extensive attention for the ir capacity to achieve a combination of bioimaging and therapeutic ***,we developed a novel PLM,LiYGeO_4:Bi^(3+),Pr^(3+),that simultaneously exhibits UV and NIR dual persistent luminescence(PersL)emissions after irradiation by *** material can be re peatedly excited by X-ray and emits similar lumine scence intensity every time,which shows good PersL *** addition,LiYGeO_4:Bi^(3+),Pr^(3+)exhibits photostimulated PersL properties by stimulation with a red light-emitting diode(LED)or NIR laser after long-term *** work provides a new choice of X-ray-excited PLMs with UV and NIR dual emission and the novel phosphor shows promise as a potential candidate for the integration of treatment and diagnosis of deep tumors.

关键词： Co-doping X-ray-activated Dual emissions Persistent luminescence Rare earths

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Micromechanical interlocking-inspired dendritic porous silicabased multimodal resin composites for the tooth restoration

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Nano Research 2024年第10期17卷 9065-9077页

作者： Hongyan Chen Junjun Wang shi yin Ruili Wang Xinquan Jiang Meifang Zhu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Material Science and EngineeringDonghua UniversityShanghai 201620China Shanghai Engineering Research Center of Advanced Dental Technology and Materials Shanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyNational Clinical Research Center for Oral DiseasesShanghai Ninth People’s HospitalCollege of StomatologyShanghai Jiao Tong University School of MedicineShanghai 200011China

Porous silica particles have shown great potential application as reinforcing fillers in the field of dentistry due to their ability to construct the micromechanical interlocking effect at filler-matrix ***,how to accurately regulate the pore structure,especially the pore size,to increase the degree of the micromechanical interlocking and the performance of materials remains a ***,we have proposed a facile self-assembly process to synthesize dendritic porous silica with tunable pore sizes(DPS-x)by adjusting the chain-length of the alcohols in the *** mechanism of nucleation-growth is further put *** results indicate that the pore size of DPS-x indeed affects the mechanical property of composites,where the DPSpen particles with intermediate pore size are chosen as the optimal reinforcing *** bimodal and multimodal filler formulations are further established to address the loading limitation of unimodal DPS-pen(46 wt.%).In virtue of the closepacked structure of identical spheres,the particle sizes of secondary silica embedded into the maximally loaded bimodal D3S7 composite(DPS-pen:Si430=30:70,w/w)are theoretically calculated without *** all formulations,the developed multimodal D3S7+Si178+Si90 filler exhibits superior mechanical properties,the lowest shrinkage,and high polymerization conversion for dental composites,along with satisfied waster sorption and solubility,and good biocompatibility in vitro and in vivo,which are comparable to commercial composite Z350 XT(3M,USA).These DPS-x particles and their multimodal fillers can also be applied to other polymer-based biomaterials.

关键词： porous silica pore size multimodal filler dental composite physicochemical properties biosafety

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突出煤层卸压瓦斯抽采消突技术

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矿业安全与环保 2010年第S1期37卷 46-47页

作者：石银斌神华宁夏煤业集团公司汝箕沟煤矿宁夏平罗753404

通过对矿井不同生产条件的穿层钻孔、顺层钻孔卸压瓦斯抽采消突技术的探索及应用,消除了采掘工程中的瓦斯突出和瓦斯超限,确保了矿井安全生产。

关键词：卸压消突穿层钻孔顺层钻孔瓦斯抽采

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汝箕沟煤矿煤与瓦斯突出危险性区域划分技术

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矿业安全与环保 2010年第S1期37卷 71-72,75页

作者：石银斌神华宁夏煤业集团汝箕沟煤矿宁夏平罗753404

按《防治煤与瓦斯突出规定》要求,突出煤层的区域突出危险性预测采用单项指标(二指标法),但由于煤与瓦斯突出机理的复杂性,汝箕沟煤矿在实际应用过程中采用多种指标共同预测,结果互相参考印证,可以提高突出危险性预测的准确性。

关键词：煤与瓦斯突出危险性区域划分

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Experimental investigation of dynamic characteristics of leaching tubing for solution mining of salt cavern carbon and energy storage

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Petroleum Science 2024年第4期21卷 2703-2722页

作者： yin-Ping Li Xin-Bo Ge Xi-Lin shi Hong-Ling Ma State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences University of Chinese Academy of Sciences College of Energy and Mining Engineering Shandong University of Science and Technology State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology

Salt caverns are extensively utilized for storing various substances such as fossil energy, hydrogen,compressed air, nuclear waste, and industrial solid waste. In China, when the salt cavern is leached through single-well water solution mining with oil as a cushion, engineering challenges arise with the leaching tubing, leading to issues like damage and instability. These problems significantly hinder the progress of cavern construction and the control of cavern shape. The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space, which results in severe bending or damage to the tubing. This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus. The experiment utilizes a silicone-rubber pipe(SRP) and a polycarbonate pipe(PCP) to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid. These factors include external space constraint, flexural rigidity, medium outside the pipe, overhanging length, and end conditions. The experiments reveal four dynamic response phenomena: water hammer, static buckling, chaotic motion, and flutter instability. The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid. Additionally, the flutter critical flow velocity is influenced by the end conditions and different external media.

关键词： Salt cavern storage Solution mining Leaching tubing Experimental investigation Flutter instability

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Synergistic effect of Zr and Mo on precipitation and high-temperature properties of Al-Si-Cu-Mg alloys

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China Foundry 2024年第1期21卷 71-81页

作者： Chao Gao bing-rong Zhang yin-ming Li Zhi-ming Wang Xiang-bin Meng Faculty of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Hebei Ounai Machinery Mould Co.Ltd. Xingtai 054500HebeiChina

This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg *** synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were *** show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the *** can improve the strength of the alloy by hindering dislocation movement and crack *** addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain *** addition of Mo greatly improves the heat resistance of the *** extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy.

关键词： Al-Si-Cu-Mg alloy high-temperature properties Zr-Mo-rich intermetallics nano-strengthening phases

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Multistate transition and coupled solid-liquid modeling of motion process of long-runout landslide

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2694-2714页

作者： Yang Gao Yueping yin bin Li Han Zhang Weile Wu Haoyuan Gao Institute of Geomechanics Chinese Academy of Geological SciencesChina Geological SurveyBeijing100081China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesBeijing100081China China Institute of Geological Environment Monitoring China Geological SurveyBeijing100081China School of Geological Engineering and Geomatics Chang’an UniversityXi’an710054China

The recognition,repetition and prediction of the post-failure motion process of long-runout landslides are key scientific problems in the prevention and mitigation of geological *** this study,a new numerical method involving LPF3D based on a multialgorithm and multiconstitutive model was proposed to simulate long-runout landslides with high precision and *** following results were obtained:(a)The motion process of landslides showed a steric effect with mobility,including gradual disintegration and *** sliding mass can be divided into three states(dense,dilute and ultradilute)in the motion process,which can be solved by three dynamic regimes(friction,collision,and inertial);(b)Coupling simulation between the solid grain and liquid phases was achieved,focusing on drag force influences;(c)Different algorithms and constitutive models were employed in phase-state *** volume fraction is an important indicator to distinguish different state types and solid‒liquid *** flume experimental results were favorably validated against long-runout landslide case data;and(d)In this method,matched dynamic numerical modeling was developed to better capture the realistic motion process of long-runout landslides,and the advantages of continuum media and discrete media were combined to improve the computational accuracy and *** new method can reflect the realistic physical and mechanical processes in long-runout landslide motion and provide a suitable method for risk assessment and pre-failure prediction.

关键词： Long-runout landslide Multistate transition Mixed solid‒liquid flow Post-failure process Numerical simulation

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Joint Optimization of Energy Consumption and Network Latency in Blockchain-Enabled Fog Computing Networks

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China Communications 2024年第4期21卷 104-119页

作者： Huang Xiaoge yin Hongbo Cao bin Wang Yongsheng Chen Qianbin Zhang Jie School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China School of Communication and Information Engineering University of SheffieldUnited Kingdom

Fog computing is considered as a solution to accommodate the emergence of booming requirements from a large variety of resource-limited Internet of Things(IoT)*** ensure the security of private data,in this paper,we introduce a blockchain-enabled three-layer device-fog-cloud heterogeneous network.A reputation model is proposed to update the credibility of the fog nodes(FN),which is used to select blockchain nodes(BN)from FNs to participate in the consensus *** to the Rivest-Shamir-Adleman(RSA)encryption algorithm applied to the blockchain system,FNs could verify the identity of the node through its public key to avoid malicious ***,to reduce the computation complexity of the consensus algorithms and the network overhead,we propose a dynamic offloading and resource allocation(DORA)algorithm and a reputation-based democratic byzantine fault tolerant(R-DBFT)algorithm to optimize the offloading decisions and decrease the number of BNs in the consensus algorithm while ensuring the network *** results demonstrate that the proposed algorithm could efficiently reduce the network overhead,and obtain a considerable performance improvement compared to the related algorithms in the previous literature.

关键词： blockchain energy consumption fog computing network Internet of Things latency

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