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Rhodium-catalyzed Doyle-Kirmse rearrangement reactions of sulfoxoniun ylides

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Chinese Chemical Letters 2024年第4期35卷 363-366页

作者： Ying-Di Hao zhi-qian Lin Xiao-Yu Guo Jiao Liang Can-Kun luo qian-Tao Wang Li Guo Yong Wu Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial TechnologyWest China School of PharmacySichuan UniversityChengdu 610041China

Doyle-Kirmse rearrangement reactions have received continuous attention as an important method for constructing complex chemical structures. Herein, we disclosed an efficient rhodium-catalyzed DoyleKirmse rearrangement reaction, which can simultaneously construct C–C bonds and C–X(X = S/Se) bonds using sulfoxonium ylides as starting materials to obtain sulfur-or selenium-containing compounds. This strategy is characterized by the safer and greener carbene precursor, high yields and broad substrate scope, possessing a wide range of application.

关键词： Sulfoxonium ylides Rhodium(Ⅱ)-catalyzed Carbene Rearrangement reactions One-pot process

Study on the tribological properties of metal rolling bearing under lubrication with diketone lubricants

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Science China(Technological Sciences) 2024年第7期67卷 2003-2017页

作者： DU ShaoNan ZHANG ChenHui luo zhi State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Beijing National Laboratory of Molecular Sciences CAS Key Laboratory of Engineering PlasticsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

In this article, 1-(4-ethylphenyl)-nonane-1,3-dione(0206) was prepared by Claisen condensation. By mixing 0206, chelate, and base oil in a ratio of 3.2:4.8:2, a diketone lubricant(PAO=14(20%)) that can achieve superlubricity was prepared and applied to bearing lubrication experiments. The experimental results show that when the bearing was lubricated by base oil, the friction coefficient(COF) and temperature rise decreased with the decrease of the viscosity of PAO. When PAO=14(20%) was used as the lubricant, the COF of the bearing was the lowest(0.001), and the wear morphology was comparable to that of the bearing lubricated with commercial lubricant. Compared with the base oil with the same viscosity, it is found that the COF and temperature rise of the bearing lubricated by PAO=14(20%) were lower under any experimental conditions. And when the amount of lubricant added was 10 μL, the COF of the bearing lubricated by PAO=14(20%) reached a very low value(0.0004).Bearing ball surface analysis identified the formation of diketone adsorption films. Combined with the previous PAO=14(20%)superlubricity mechanism, it was considered that the occurrence of tribochemical reaction and the bearing effect of chelates were the main reasons for the existence of ultra-low friction coefficient and low wear. In addition, when there were polar molecules in the lubricant, they were adsorbed on the metal surface through tribochemical reactions, resulting in many irregular pits on the surface.

关键词： superlubricity diketone chelate tribochemical recations bearing lubrication

Reduction of dinitrogen to ammonia on doped three-atom clusters Nb_(2)M(M=Sc to Cu & Y to Ag)

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Rare Metals 2024年第8期43卷 3810-3818页

作者： Ran Cheng Chao-Nan Cui zhi-Xun luo Beijing National Laboratory for Molecular Science(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Science University of Chinese Academy of SciencesBeijing 100049China

Catalytic reduction of dinitrogen to ammonia under mild conditions remains an attractive topic for the purpose of lowering energy ***-atom metal clusters have been proved an ideal model to explore highly efficient catalysts taking advantage of unique geometric/electronic structures and cooperative active *** a study of N2 activation and reduction on seventeen bimetallic Nb_2M(M=Sc to Cu,and Y to Ag) clusters was *** key processes for ammonia fixation(namely nitrogen activation,hydrogenation,and ammonia desorption) are fully studied,and three preferred systems(Nb_2Ni,Nb_2Rh and Nb_2Pd) are highlighted with outstanding catalytic *** d-σ and d-π~* orbital hybridizations between these metal clusters and N_(2) were demonstrated and the internal association with the N≡N bond activation was *** examining the ammonia synthesis on four chosen Nb_(2)M clusters(M=Fe,Ni,Rh and Pd),it can be elucidated that the distal pathway is more favorable than the alternative pathway in these *** work not only clarifies the N_(2) reduction on the bimetallic Nb_(2)M clusters,but also guides efficient bimetallic catalyst design.

关键词： Three-atom cluster catalysis Three-criteria strategy Nitrogen fixation Ammonia synthesis Theoretical calculations

High-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： Wei-zhi luo Mu He Liang Xia Qi-Chang He State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Laboratoire Modélisation et Simulation Multi-Echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

3D robust anisotropic diffusion filtering algorithm for sparse view neutron computed tomography 3D image reconstruction

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Nuclear Science and Techniques 2024年第3期35卷 13-29页

作者： Yang Liu Teng-Fei Zhu zhi luo Xiao-Ping Ouyang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Xi’an 710024China

The most critical part of a neutron computed tomography(NCT) system is the image processing algorithm,which directly affects the quality and speed of the reconstructed *** types of noise in the system can degrade the quality of the reconstructed ***,to improve the quality of the reconstructed images of NCT systems,efficient image processing algorithms must be *** anisotropic diffusion filtering(ADF) algorithm can not only effectively suppress the noise in the projection data,but also preserve the image edge structure information by reducing the diffusion at the image ***,we propose the application of the ADF algorithm for NCT image *** compare the performance of different algorithms in NCT systems,we reconstructed images using the ordered subset simultaneous algebraic reconstruction technique(OS-SART) algorithm with different regular terms as image processing *** the iterative reconstruction,we selected two image processing algorithms,the Total Variation and split Bregman solved total variation algorithms,for comparison with the performance of the ADF ***,the filtered back-projection algorithm was used for comparison with an iterative *** reconstructing the projection data of the numerical and clock models,we compared and analyzed the effects of each algorithm applied in the NCT *** on the reconstruction results,OS-SART-ADF outperformed the other algorithms in terms of denoising,preserving the edge structure,and suppressing *** example,when the 3D Shepp–Logan was reconstructed at 25 views,the root mean square error of OS-SART-ADF was the smallest among the four iterative algorithms,at only *** universal quality index,mean structural similarity,and correlation coefficient of the reconstructed image were the largest among all algorithms,with values of 0.9877,0.9878,and 0.9887,respectively.

关键词： NCT OS-SART Sparse-view Anisotropic diffusion filtering

Rapid chemical recycling of waste polyester plastics catalyzed by recyclable catalyst

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Green Chemical Engineering 2024年第2期5卷 257-265页

作者： Yu-Ji luo Jia-Yin Sun zhi Li School of Physical Science and Technology ShanghaiTech UniversityShanghai201210China

Waste plastics are serious environmental threats due to their low degradability and low recycling *** and efficient waste plastics recycling technologies are urgently demanded for a sustainable ***,we report a rapid,closed-loop,and streamlined process to convert polyesters such as poly(ethylene terephthalate)(PET)back to its purified *** trifluoromethanesulfonic acid or metal triflates as the recyclable catalyst,polyesters such as PET can be completely depolymerized by simple carboxylic acids within 1 *** coupling this acidolysis with a subsequent hydrogenolysis process,the consumed carboxylic acid was recovered and the closed-loop of PET depolymerization could be *** catalysts and depolymerization agents are fully recycled while only PET and hydrogen are consumed.

关键词： Chemical recycling Waste polyester plastics Acidolysis Recyclable catalyst

Research progress on micro-force measurement of a hydrate particle system

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Petroleum Science 2024年第4期21卷 2169-2183页

作者： qiang luo Wei Li zhi-Hui Liu Feng Wang zhi-Chao Liu Fu-Long Ning Faculty of Engineering China University of Geosciences (Wuhan) Suzhou Laboratory

It remains a great challenge to understand the hydrates involved in phenomena in practical oil and gas systems. The adhesion forces between hydrate particles, between hydrate particles and pipe walls, and between hydrate particles and reservoir particles are essential factors that control the behaviors of clathrate hydrates in different applications. In this review, we summarize the typical micro-force measurement apparatus and methods utilized to study hydrate particle systems. In addition, the adhesion test results, the related understandings, and the applied numerical calculation models are systematically discussed.

关键词： Clathrate hydrates Hydrate particle Micro-force measurements Adhesion Interactions

An improved positioning model of deep-seafloor datum point at large incidence angle

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Journal of Oceanology and Limnology 2024年第1期42卷 90-100页

作者： qianqian LI Shoulian CAO Fanlin YANG Yu luo qian TONG College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150000China College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Ocean Geomatics Ministry of Natural ResourcesQingdao 266590China

The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic *** raytracing method is an indispensable tool for effectively handling ***,this method has a conflict between localization accuracy and computational *** equivalent sound speed profile(ESSP)method uses a simple sound speed profile(SSP)instead of the actual complex SSP,which can improve positioning precision but with residual *** residual error is especially non-negligible in deep water and at large beam incidence *** analyzing the residual error of the ESSP method through a simulation,an empirical formula of error is *** data collected in the sailing circle mode(large incidence angle)of the South China Sea are used for *** experiments show that compared to the ESSP method,the improved algorithm has higher positioning precision and is more efficient than the ray-tracing method.

关键词： underwater acoustic positioning seafloor datum points large incident angle equivalent sound speed profile(ESSP) deep water

Security-constrained Transmission Maintenance Optimization Considering Generation and Operational Risk Costs

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 767-781页

作者： Dan Xu zhi Cai qian Cheng Guodong Huang Jingyang Zhou Junjie Tang Beijing Key Laboratory of Research and System Evaluation of Power Dispatching Automation Technology China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China

With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power ***,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed *** model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission ***,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution *** cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment *** electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence *** IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.

关键词： Transmission maintenance security-constrained unit commitment iterative algorithm cost feedback N−1 risk assessment