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Role of methoxy and C_(α)-based substituents in electrochemical oxidation mechanisms and bond cleavage selectivity of β-O-4 lignin model compounds

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Green Energy & Environment 2024年第1期9卷 114-125页

作者： Yang Zhou qiang Zeng Hongyan He Kejia Wu Fuqiao liu Xuehui Li School of Chemistry and Chemical Engineering The Guangdong Provincial Key Laboratory of Green Chemical Product TechnologyState Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouGuangdong510640China CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.

关键词： Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect

Mechanical behaviors of backfill-rock composites: Physical shear test and back-analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 807-827页

作者： Jie Xin Quan Jiang Fengqiang Gong Lang liu Chang liu qiang liu Yao Yang Pengfei Chen State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China School of Civil Engineering Southeast UniversityNanjing211189China Energy School Xi’an University of Science and TechnologyXi’an710054China

The shear behavior of backfill-rock composites is crucial for mine safety and the management of surface *** exposing the shear failure mechanism of backfill-rock composites,we conducted shear tests on backfill-rock composites under three constant normal loads,compared with the unfilled *** investigate the macro-and meso-failure characteristics of the samples in the shear tests,the cracking behavior of samples was recorded by a high-speed camera and acoustic emission *** parallel with the experimental test,the numerical models of backfill-rock composites and unfilled rock were established using the discrete element method to analyze the continuous-discontinuous shearing *** on the damage mechanics and statistics,a novel shear constitutive model was proposed to describe mechanical *** results show that backfill-rock composites had a special bimodal phenomenon of shearing load-deformation curve,*** first shearing peak corresponded to rock break and the second shearing peak induced by the broken of aeolian sand-cement/fly ash paste ***,the shearing characteristic curves of the backfill-rock composites could be roughly divided into four stages,*** shear failure of the specimens experienced:stage I:stress concentration;stage II:crack propagation;stage III:crack coalescence;stage IV:shearing *** numerical simulation shows that the existence of aeolian sand-cement/fly ash paste backfill inevitably altered the coalescence type and failure mode of the specimens and had a strengthening effect on the shear strength of backfillrock *** on damage mechanics and statistics,a shear constitutive model was proposed to describe the shear fracture characteristics of specimens,especially the bimodal ***,the micro-and meso-mechanisms of shear failure were discussed by combining the micro-test and numerical *** research can advance the better understanding of the shear behavior of

关键词： Physical simulation Backfill-rock composites Shear failure Cracking Shear constitutive model

B cell development and antibody responses in human immune system mice:current status and future perspective

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Science China(Life Sciences) 2024年第4期67卷 645-652页

作者： Tao Zhang Wentao liu yong-Guang Yang Key Laboratory of Organ Regeneration&Transplantation of the Ministry of Education The First Hospital of Jilin UniversityChangchun 130061China National-Local Joint Engineering Laboratory of Animal Models for Human Diseases Jilin UniversityChangchun 130061China International Center of Future Science Jilin UniversityChangchun 130061China

Humanized immune system(HIS)mice have been developed and used as a small surrogate model to study human immune function under normal or disease *** variations are found between models,most HIS mice show robust human T cell ***,there has been unsuccessful in constructing HIS mice that produce high-affinity human antibodies,primarily due to defects in terminal B cell differentiation,antibody affinity maturation,and development of primary follicles and germinal *** this review,we elaborate on the current knowledge about and previous attempts to improve human B cell development in HIS mice,and propose a potential strategy for constructing HIS mice with improved humoral immunity by transplantation of human follicular dendritic cells(FDCs)to facilitate the development of secondary follicles.

关键词： humanized immune system mouse humoral immunity germinal center B cell follicular dendritic cell

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Intraoperative ultrasonography in ＂cave-in＂ 360° circumferential decompression for thoracic spinal stenosis

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Chinese Medical Journal 2011年第23期124卷 3879-3885页

作者： WANG yong-qiang liu Xiao-guang JIANG Liang JIANG Ling WEI Feng YU Miao liu Zhong-jun Department of Orthopaedics Peking University Third Hospital Beijing 100191 China

The surgical outcomes of decompression for thoracic spinal stenosis （TSS） are unfavorable. The purpose of this study was to determine the efficacy of intraoperative ultrasonography during ＂cave-in＂ 360~ circumferential decompression surgery in patients with TSS. Methods Thirteen patients with TSS underwent ＂cave-in＂ 360° circumferential decompression surgery between May 2010 and November 2010. Intraoperative ultrasonography was used after removal of the posterior wall of thoracic spinal canal to assess the morphologic restoration of the spinal cord and the anterior surface of the spinal canal. In seven patients, ultrasonography was used again after circumferential decompression to compare the cross-sectional area of the spinal cord before and after circumferential decompression. Results The average period of follow-up was （12±2） months （range 9-15 months）. The Japanese Orthopedic Association score was significantly higher at the final follow-up （8.5±2.1, range 3-10） than preoperatively （5.2±1.1, range 3-7; P 〈0.01）. The cross-sectional area of the spinal cord was （30.8±6.6） mm2 before and （53.6±19.1） mm2 after circumferential decompression （P 〈0.01）. For five patients with TSS caused by thoracic disc herniation, the levels of circumferential decompression performed corresponded to those expected preoperatively. In contrast, for eight patients with TSS caused by ossification of the posterior longitudinal ligament, on average 1.6±0.9 fewer levels of circumferential decompression were performed than expected preoperatively. Conclusions ＂Cave-in＂ 360° circumferential decompression is an effective therapeutic option for TSS. Intraoperative ultrasonographic evaluation may reduce the levels of circumferential decompression and ensure sufficient decomoression, and increase the efficacy of this surqical technique.

关键词： spinal stenosis ossification of the posterior longitudinal ligament "cave-in" technique circumferential decompression ultrasonography ossification-kyphosis angle

Progress in research on metal-based materials in stabilized Zn anodes

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Rare Metals 2024年第1期43卷 20-40页

作者： Le Li Shao-Feng Jia Ming-Hui Cao yong-qiang Ji Heng-Wei Qiu Dan Zhang Shaanxi Key Laboratory of Industrial Automation School of Mechanical EngineeringShaanxi University of TechnologyHanzhong 723001China School of Electronic and Information Engineering Qingdao UniversityQingdao 266071China State Key Laboratory for Artifcial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Department of Chemistry Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyTsinghua UniversityBeijing 100084China Shaanxi Key Laboratory of Catalysis School of Chemistry and Environment ScienceShaanxi University of TechnologyHanzhong 723001China

Aqueous zinc-ion batteries(ZIBs) combine the benefits of metallic Zn anodes with those of aqueous electrolytes and are well suited for large-scale energy storage because of their inherent high safety, cost-effectiveness, and eco-friendliness. Currently, the practical application of such batteries is hindered by the poor cycling performance of Zn anodes due to uncontrolled dendrite formation and severe side reactions, although recent reports suggest that these problems can be mitigated through the modification of Zn anodes with metal-based *** that the mechanisms of improving Zn deposition and the structural evolution of metal-based materials have not been systematically reviewed, we herein systematically overview the metal-based materials used to stabilize Zn anodes, starting with a brief summary of the anode working mechanism and the challenges faced by stabilized Zn anodes. Subsequently, the design principles of Zn anodes stabilized by metal-based materials and the related recent progress are reviewed, and the key challenges and perspectives for the future development of such Zn anodes are proposed.

关键词： Zinc-ion batteries(ZIBs) Zn anode Metalbased materials Alloying metal Stabilized Zn anodes

Generation of mitochondrial replacement monkeys by female pronucleus transfer

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Zoological Research 2024年第2期45卷 292-298页

作者： Chun-Yang Li Xing-Chen liu Yu-Zhuo Li Yan Wang Yan-Hong Nie Yu-Ting Xu Xiao-Tong Zhang yong Lu qiang Sun Institute of Neuroscience Center for Excellence in Brain Science and Intelligence TechnologyState Key Laboratory of NeuroscienceChinese Academy of SciencesShanghai 200031China Key Laboratory of Genetic Evolution and Animal Models Chinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China

Mutations in mitochondrial DNA(mtDNA)are maternally inherited and have the potential to cause severe *** replacement therapies,including spindle,polar body,and pronuclear transfers,are promising strategies for preventing the hereditary transmission of mtDNA *** pronuclear transfer has been used to generate mitochondrial replacement mouse models and human embryos,its application in non-human primates has not been previously *** this study,we successfully generated four healthy cynomolgus monkeys(Macaca fascicularis)via female pronuclear *** individuals all survived for more than two years and exhibited minimal mtDNA carryover(3.8%–6.7%),as well as relatively stable mtDNA heteroplasmy dynamics during *** successful establishment of this nonhuman primate model highlights the considerable potential of pronuclear transfer in reducing the risk of inherited mtDNA diseases and provides a valuable preclinical research model for advancing mitochondrial replacement therapies in humans.

关键词： Non-human primates Mitochondrial replacement Female pronuclear transfer

Engineering the Interface Between Au Nanoparticles and CoO-Ov to Enhance the Catalytic Performance of 5-Hydroxymethylfurfural(HMF)to 2,5-Dimethylfuran(DMF)

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Chemical Research in Chinese Universities 2024年第1期40卷 47-54页

作者： XIANG Shuang GUO yong liu Xiaohui WANG Yanqin Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterResearch Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237P.R.China

The interface between Au and support has attracted extensive interest because of its unique catalytic ability for hydrogen activation in catalytic hydrogenation/hydrogenolysis ***,we create the Au-CoO-OV interface in the 1.0%Au/Co3O4-Rod-250 catalyst,which could dissociate H2 via the heterolytic way to yield rich hydride species and achieve excellent catalytic performance in the hydrogenolysis of biomass-derived 5-hydroxymethylfurfural(HMF)to 2,5-dimethylfuran(DMF).The XRD and HRTEM analyses show that Au nanoparticles are uniformly dispersed on CoO-OV surface and in situ DRIFTS spectra show the enhancement of heterolytic dissociation of hydrogen(signals of Au-D and O-D vibration)compared with bare CoO(Co3O4-Rod-250).This work provides insights for fabricating highly active Au-support catalysts for catalytic hydrogenation/hydrogenolysis reactions.

关键词： Au-CoO-OV interface Hydride species Heterolytic dissociation 5-Hydroxymethylfurfural(HMF) 2 5-Dimethylfuran(DMF)

On the Probability of Generating a Primitive Matrix

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Journal of Systems Science & Complexity 2024年第4期37卷 1755-1771页

作者： CHEN Jingwei FENG yong liu Yang WU Wenyuan Chongqing Key Laboratory of Automated Reasoning and Cognition Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Chongqing College University of Chinese Academy of SciencesChongqing 400714China Key Laboratory of Advanced Manufacturing Technology of Ministry of Education Guizhou UniversityyGuiyang 550025China Information Science and Engineering Chongqing Jiaotong UniversityChongqing 400074China

Given a k×n integer primitive matrix A(i.e.,a matrix can be extended to an n×n unimodular matrix over the integers)with the maximal absolute value of entries‖A‖bounded by an integer λ from above,the authors study the probability that the m×n matrix extended from A by appending other m-k row vectors of dimension n with entries chosen randomly and independently from the uniform distribution over{0,1,…,λ-1}is still *** authors present a complete and rigorous proof of a lower bound on the probability,which is at least a constant for fixed m in the range[k+1,n-4].As an application,the authors prove that there exists a fast Las Vegas algorithm that completes a k×n primitive matrix A to an n×n unimodular matrix within expected O(n^(ω)log‖A‖)bit operations,where O is big-O but without log factors,ω is the exponent on the arithmetic operations of matrix multiplication.

关键词： Integer matrix matrix completion probabilistic algorithm unimodular matrix

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Empirical likelihood for spatial cross-sectional data models with matrix exponential spatial specification

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 125-139页

作者： liu Yan RONG Jian-rong QIN yong-song Nanning University Nanning 530200China Center for Applied Mathematics of Guangxi and College of Mathematics and Statistics Guangxi Normal UniversityGuilin 541004China

In this paper,we study spatial cross-sectional data models in the form of matrix exponential spatial specification(MESS),where MESS appears in both dependent and error *** empirical likelihood(EL)ratio statistics are established for the parameters of the MESS *** is shown that the limiting distributions of EL ratio statistics follow chi-square distributions,which are used to construct the confidence regions of model *** experiments are conducted to compare the performances of confidence regions based on EL method and normal approximation method.

关键词： MESS empirical likelihood con dence region