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Construction of a Metallacyclopentadiene Ring through the Attack of Carbanions to M≡C Bond Followed by C—H Activation

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Chinese Journal of Chemistry 2024年第3期42卷 235-242页

作者： chun Tang Shengjie Zhang Zhengyu Lu Qian li Ming Luo Dafa Chen Haiping Xia State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringCollaborative Innovation Center of Chemistry for Energy MaterialsXiamen UniversityXiamenFujian361005 China Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis Department of ChemistrySouthern University of Science and TechnologyShenzhenGuangdong518055 China

Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are *** this study,a formal[3+2]method,through the reactions of an osmapentalyne with benzyl carbanions,was *** reactions underwent a nucleophilic attack of carbanions to the Os≡C bond,followed by C—H activation to form the five-membered osmacyclopentadiene *** of the reactions were carried out at room temperature,the substituents on the aromatic rings of benzyl carbanions are diverse,and the resulting products contain an Os—H bond,representing a novel type of 10C-carbolong *** work provides a new convenient route to construct metallacyclopentadienes,which is expected to further promote the development of such a type of substances.

关键词： Metallacyclopentadiene Carbolong chemistry Osmium C–H activation Nucleophilic addition

Development of a DFN-based probabilistic block theory approach for bench face angle design in open pit mining

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3047-3062页

作者： Jianhua Yan Xiansen Xing Zhihai li Weida Ni liuyuan Zhao chun Zhu Yuanyuan He School of Earth Sciences and Engineering Hohai UniversityNanjing210098China POWERCHINA Huadong Engineering Corporation limited Hangzhou311122China Zhejiang Huadong Construction Corporation limited Hangzhou310004China The Seventh Geological Brigade of Hubei Geological Bureau Yichang443000China

In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation *** this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable *** study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks *** proposed approach was applied to a granite mine in ***,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit ***,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each ***,a bench face angle was determined commensurate with an acceptable risk level of *** simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities.

关键词： Open pit mine Bench face angle Block theory Probabilistic approach Discrete fracture network modeling Fractured rock slope

Regulating metal-acid double site balance on mesoporous SiO2-Al2O3 composite oxide for supercritical n-decane cracking

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Petroleum Science 2024年第4期21卷 2881-2891页

作者： liu-ling Chen Jun Zhang chun-Guang li li-Qun Fei Bo Wang Chen-Qi Zhang Yi Jiao Jian-li Wang Institute of New Energy and Low-Carbon Technology Sichuan University Engineering Research Center of Combustion and Cooling for Aerospace Power Ministry of Education School of Chemical Engineering Sichuan University State Key Laboratory of Industrial Vent Gas Reuse Southwest Institute of Chemical Co. Ltd Science and Technology on Scramjet Laboratory Beijing Power Machinery Research Institute

The balance between metal and acid sites directly affects the preparation of high-performance cracking catalysts with high heat sink and low ***,how to control acid-metal sites balance and its relationship with cracking performance are reported *** this work,a series of Pt/Al2O3-SiO2dual sites catalysts with different metal to acid active sites ratio(CM/CSA) were constructed by ethanolassisted impregnation method and the impact on n-decane cracking under supercritical conditions was systematically and deeply *** results showed that the conversion and carbon deposition increased gradually with varied CM/CSAand reached the balance at CM/CSAof *** proper ratio CM/CSA（0.13） can balance the deep dehydrogenation coking over metal active sites and high heat sink of cracking over acid active sites,the chemical heat sink reaches amazing 1.75 MJ/kg and carbon deposition is only22.03 mg/cm2at 750℃.Meanwhile,the few metal sites at low CM/CSAand the few strong acid sites at high CM/CSAare the main factors limiting the cracking *** CM/CSAlimit the activation of C-H bond and deep dehydrogenation of coking precursor,resulting in relative low cracking activity and carbon deposition,while high CM/CSAlimit the activation of C-C bond and increase the deep *** this contribution,design and construction of metal-acid dual sites can not only provide the technical solution for the preparation of high heat sink and low coking cracking catalyst,but also deepen the understanding of the cracking path of hydrocarbon fuel.

关键词： Metal-acid dual sites balance Catalytic cracking Hydrocarbon fuels Chemical heat sink Carbon deposition

Prediction of contact resistance of electrical contact wear using different machine learning algorithms

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Friction 2024年第6期12卷 1250-1271页

作者： Zhen-bing CAI chun-lin li Lei YOU Xu-dong CHEN li-ping HE Zhong-qing CAO Zhi-nan ZHANG Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

H62 brass material is one of the important materials in the process of electrical energy transmission and signal transmission,and has excellent performance in all *** the wear behavior of electrical contact pairs is particularly complex when they are in service,we evaluated the effects of load,sliding velocity,displacement amplitude,current intensity,and surface roughness on the changes in contact *** learning(ML)algorithms were used to predict the electrical contact performance of different factors after wear to determine the correlation between different factors and contact *** forest(RF),support vector regression(SVR)and BP neural network(BPNN)algorithms were used to establish RF,SVR and BPNN models,respectively,and the experimental data were trained and *** was proved that BP neural network model could better predict the stable mean resistance of H62 brass alloy after *** analysis shows that the load and current have great influence on the predicted electrical contact *** wear behavior of electrical contacts is influenced by factors such as load,sliding speed,displacement amplitude,current intensity,and surface roughness during *** learning algorithms can predict the electrical contact performance after wear caused by these *** results indicate that an increase in load,current,and surface roughness leads to a decrease in stable mean resistance,while an increase in displacement amplitude and frequency results in an increase in stable mean resistance,leading to a decline in electrical contact *** reduce testing time and costs and quickly obtain the electrical contact performance of H62 brass alloy after wear caused by different factors,three algorithms(random forest(RF),support vector regression(SVR),and BP neural network(BPNN))were used to train and test experimental results,resulting in a machine learning model suitable for predicting the stable mean

关键词： electrical contact wear contact resistance machine learning(ML) neural network

Atomistic understanding of capacity loss in liNiO_(2)for high-nickel li-ion batteries:First-principles study

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Chinese Physics B 2024年第5期33卷 625-629页

作者：彭率陈丽娟何长春杨小宝 School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510000China Center of Excellence for Advanced Materials Dongguan 523808China

Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of liNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formation energy of li_(x)NiO_(2).Meanwhile,the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4,2/5,3/7,1/2,2/3,3/4,5/6,and 6/7 are *** understand the capacity decay in the experiment during the charge/discharge cycles,deoxygenation and li/Ni antisite defects are calculated,revealing that the chains of oxygen vacancies will be energetically *** can be inferred that in the absence of oxygen atom in high delithiate state,the diffusion of Ni atoms is facilitated and the formation of li/Ni antisite is induced.

关键词： li-ion battery ground state formation energy oxygen vacancy li/Ni antisite

Cytochrome P45026A1 Contributes to the Maintenance of Neuropathic Pain

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Neuroscience Bulletin 2024年第3期40卷 293-309页

作者： De-li Cao ling-Jie Ma Bao-chun Jiang Qiang Gu Yong-Jing Gao Institute of Pain Medicine and Special Environmental Medicine Co-innovation Center of NeuroregenerationNantong UniversityNantong226019China Nantong University Medical School Nantong226001China Department of Pain Management The Affiliated Hospital of Nantong UniversityNantong226001China

The cytochrome P450 proteins(CYP450s)have been implicated in catalyzing numerous important biological reactions and contribute to a variety of ***26A1,a member of the CYP450 family,carries out the oxidative metabolism of retinoic acid(RA),the active metabolite of vitamin *** we report that CYP26A1 was dramatically upregulated in the spinal cord after spinal nerve ligation(SNL).CYP26A1 was mainly expressed in spinal neurons and *** analysis displayed that the content of all-trans-RA(at-RA),the substrate of CYP26A1,was reduced in the spinal cord on day 7 after *** of CYP26A1 by siRNA or inhibition of CYP26A1-mediated at-RA catabolism by talarozole relieved the SNL-induced mechanical allodynia during the maintenance phase of neuropathic *** also reduced SNL-induced glial activation and proinflammatory cytokine production but increased anti-inflammatory cytokine(IL-10)*** RA receptors RARα,RXRβ,and RXRγwere expressed in spinal neurons and glial *** promoter of Il-10 has several binding sites for RA receptors,and at-RA directly increased Il-10 mRNA expression in ***,intrathecal IL-10 attenuated SNL-induced neuropathic pain and reduced the activation of astrocytes and ***,the inhibition of CYP26A1-mediated at-RA catabolism alleviates SNL-induced neuropathic pain by promoting the expression of IL-10 and suppressing glial ***26A1 may be a potential therapeutic target for the treatment of neuropathic pain.

关键词： CYP26A1 Microglia Astrocytes ERK P38 IL-10 Neuropathic pain

Cationic surface polarization centers on ionic carbon nitride for efficient solar-driven H2O2 production and pollutant abatement

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Chinese Chemical Letters 2024年第10期35卷 409-414页

作者： Zhenyu Hu Zhenchun Yang Shiqi Zeng Kun Wang lina li chun Hu Yubao Zhao MOE Key Laboratory for Water Quality and Conservation of the Pearl River Delta Institute of Environmental Research at Greater Bay Guangzhou University

Solar-driven H2O2production and emerging organic pollutants（EOPs） elimination are of great significance from the perspective of environmental sustainability. The efficiency of the photocatalytic reaction system is the key challenge to be addressed. In this work, the strategy of constructing surface ionic local polarization centers to enhance the exciton dissociation of the polymeric photocatalytic is *** bipyridinium cation（TMAP） is complexed on a K+-incorporated carbon nitride（CNK） framework, and the combination of local polarization centers both on the surface（bipyridinium cation） and bulk（K+cation） contributes to a superior photocatalytic H2O2production performance, affording a remarkable H2O2generation rate of 46.8 μmol h-1mg-1and a high apparent quantum yield（AQY） value of 77.5% under irradiation of 405 nm photons. As substantiated experimentally by steady state/transient spectroscopy techniques, the surface local polarization centers increase the population of the long-lived trapped electrons, and thereby promote the interfacial charge transfer process for chemical conversion reaction. The strategy is potentially applicable to the design of a wide range of efficient solar-to-chemical conversion systems.

关键词： Hydrogen peroxide production Local polarization Oxygen reduction reaction Pollutant degradation Polymeric carbon nitride

Rhegmatogenous retinal detachment in highly myopic eyes with implantable collamer lens

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International Journal of Ophthalmology(English edition) 2024年第2期17卷 392-396页

作者： Jun li Chong-lin Chen Jia-Qing li Xiao-ling liang chun Zhang State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhou 510060Guangdong ProvinceChina

AIM:To investigate the clinical characteristics,treatment methods and outcomes of rhegmatogenous retinal detachment(RRD)in highly myopic eyes with implantable collamer lens(ICL).METHODS:High myopia patients who received treatment for nontraumatic RRD after ICL implantation surgery at the Retinal Department of Zhongshan Ophthalmic Center from Jan 2018 to Dec 2022 were *** ophthalmologic examinations including visual acuity measurement and digital fundus photography were performed in each ***:A total of nine RRD eyes from nine patients who received V4c-ICL implantation were *** mean time from ICL implantation surgery to the diagnosis of RRD was 32.44±22.56mo(range,1-60mo).At the initial visit for RRD,giant retinal tear(GRT),horseshoe tear,simple round hole,and horseshoe tear combined with round hole were detected in 3,3,2,and 1 eye(s),respectively,with maculaoff in *** patients received surgical treatment,and one patient was treated by retinal laser photocoagulation *** ICL was preserved in 7 *** the last followup,the mean best corrected visual acuity(BCVA)improved significantly from 1.76±1.06 logMAR at presentation to 0.81±1.01 logMAR(P=0.035),and no case of recurrent retinal detachment was ***:The morphological presentation of retinal breaks is diverse in this *** ICL can be preserved in most cases during the course of retinal detachment repair surgery in our data,companied with acceptable visual and anatomical outcomes.

关键词： high myopia implantable collamer lens rhegmatogenous retinal detachment

Unmanned Ship Identification Based on Improved YOLOv8s Algorithm

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Computers, Materials & Continua 2024年第3期78卷 3071-3088页

作者： chun-Ming Wu Jin Lei Wu-Kai liu Mei-ling Ren ling-li Ran Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology School of Electrical EngineeringNortheast Electric Power UniversityJilin132012China School of Biomedical Engineering Taiyuan University of TechnologyTaiyuan030600China

Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes an infrared ship detection model based on the improved YOLOv8 algorithm(R_YOLO).The algorithm incorporates the Efficient Multi-Scale Attention mechanism(EMA),the efficient Reparameterized Generalized-feature extraction module(CSPStage),the small target detection header,the Repulsion Loss function,and the context aggregation block(CABlock),which are designed to improve the model’s ability to detect targets at multiple scales and the speed of model *** algorithm is validated in detail on two vessel *** comprehensive experimental results demonstrate that,in the infrared dataset,the YOLOv8s algorithm exhibits improvements in various performance ***,compared to the baseline algorithm,there is a 3.1%increase in mean average precision at a threshold of 0.5(mAP(0.5)),a 5.4%increase in recall rate,and a 2.2%increase in mAP(0.5:0.95).Simultaneously,while less than 5 times parameters,the mAP(0.5)and frames per second(FPS)exhibit an increase of 1.7%and more than 3 times,respectively,compared to the CAA_YOLO ***,the evaluation indexes on the visible light data set have shown an average improvement of 4.5%.

关键词： Unmanned ships R_YOLO EMA CSPStage YOLOv8s