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The maximal super-singular integral operators on product spaces

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Science China mathematics 2011年第12期54卷 2615-2626页

作者： wang hui1 & chen jiecheng2.3, 1department of mathematics,{2., xi’an 710071, China 2.4} of mathematics, Zhejiang Normal university, Jinhua 32.004, China 3department of mathematics, Zhejiang university, Hangzhou 31002., China department of mathematics Xidian University Xi’an China department of mathematics Zhejiang Normal University Jinhua China department of mathematics Zhejiang University Hangzhou China

We study the maximal super-singular integral operator T＊Ω,α,β（f）（x,y）=sup ∈1〉0,∈2.0｜∫｜u｜〉ε1,｜v｜〉ε2.b1（｜u｜）b2.｜u｜）Ω（u＇,u＇）/｜u｜^n＋α｜u｜^m＋β-f（x-u,y-u）dudu｜defined on all f ∈ S（R^n ×R^m）, where 0 ≤ α,β〈∞, b1 b2.∈ L∞（R＋1 ）,Ω satisfies certain cancellation conditions and Ω∈L1（S^n-1×S^m-1）in the case α,β〉0;Ω∈L（log＋L）（S^n-1×S^m-1）in the case αβ=0 and α＋β 〉0. It is proved that, for 1〈p〈∞.T＊Ω,α,βis a bounded operator from the homogeneous Sobolev space Lα,β^p（R^n×R^m）to the Lebesgue space L^p（R^n×R^m）.

关键词： super-singular integral maximal operator product spaces

Selective synthesis of the B_(11)H_(14)^(-) and B_(12.H_(12.^(2.) borane derivatives and the general mechanisms of the B-H bond condensation

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Science China Chemistry 2024年第3期67卷 876-881页

作者： Yi Jing xinghua wang {2. Han xin-Ran Liu xing-Chao Yu xi-Meng chen Dong{2. Wei Lai-Sheng wang Xuenian chen College of Chemistry Green Catalysis CenterZhengzhou UniversityZhengzhou 450001China School of Chemistry and Chemical Engineering Henan Key Laboratory of Boron Chemistry and Advanced Energy MaterialsHenan Normal UniversityXinxiang 453007China department of Chemistry Brown UniversityProvidenceRI 02912USA

Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic ***,the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B-H bond condensation reaction,critical for the synthesis of the polyhedral boranes,is not well *** we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate(1-)(B_(11)H^(-)_(14)) and dodecahydrido-dodecaborates(2.)(B_(12.H_(12.^(2.)) anions by employing commercially available and inexpensive starting *** theoretical and experimental investigations are carried out to elucidate the reaction *** have found that the nature of the B-H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens(bridged hydrogens) play a crucial *** current study has not only led to more effective and selective synthetic methods for B_(11)H^(-)_(14) and B_(12.H_(12.^(2.) but also unveiled the nature of the B-H bond condensation and the general formation mechanisms of polyhedral *** finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.

关键词： Boranes polyhedral boranes dihydrogen bond nucleophilicity

Revealing the Role of Defect in 3D Graphene-Based Photocatalytic Composite for Efficient Elimination of Antibiotic and Heavy Metal Combined Pollution

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Energy & Environmental Materials 2024年第3期7卷 164-174页

作者： xin wang Jingzhe Zhang {2. wang Mengjun Liang Qiang wang Fuming chen Research Institute of Frontier Science Southwest Jiaotong UniversityChengdu 610031China Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials School of Electronics and Information EngineeringSouth China Normal UniversityFoshan 528225China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Hubei Key Laboratory for High-Efficiency Utilization of Solar Energy and Operation Control of Energy Storage System Hubei University of TechnologyWuhan 430068China MOE Key Laboratory of Thermo-Fluid Science and Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

Defect engineering can give birth to novel properties for adsorption and photocatalysis in the control of antibiotics and heavy metal combined pollution with photocatalytic ***,the role of defects and the process mechanism are complicated and ***,TiO_(2./CN/3DC was fabricated and defects were introduced into the tripartite structure with separate O_(2.plasma treatment for the single *** find that defect engineering can improve the photocatalytic activity,attributing to the increase of the contribution from h^(+)and *** contrast to TiO_(2./CN/3DC with a photocatalytic tetracycline removal rate of 75.2.,the removal rate of TC with D-TiO_(2./CN/3DC has increased to 88.5%.Moreover,the reactive sites of tetracycline can be increased by adsorbing on the defective *** defect construction on TiO_(2.shows the advantages in tetracycline degradation and Cu^(2.)adsorption,but also suffers significant inhibition for the tetracycline degradation in a tetracycline/Cu^(2.)combined *** contrast,the defect construction on graphene can achieve the cooperative removal of tetracycline and Cu^(2.).These findings can provide new insights into water treatment strategies with defect engineering.

关键词： 3D graphene Cu defect photocatalytic composite tetracycline

Prevalence and Risk Factors of Stroke in Inpatients with Type 2.Diabetes Mellitus in China

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Current Medical Science 2024年第4期44卷 698-706页

作者： Zuo-ling xiE chen-chen wang xi HUANG Zheng wang Hai-yan SHANGGUAN Shao-hua wang department of Endocrinology the Affiliated ZhongDa Hospital of Southeast UniversityNanjing210009China School of Medicine Southeast UniversityNanjing210009China

Objective The prevalence and the cluster characteristics of risk factors of stroke were assessed in a Chinese diabetic *** Clinical data of 30693 inpatients who were diagnosed with type 2.diabetes mellitus(T2.M)and admitted between 2.13 and 2.18 were retrospectively *** age-standardized prevalence of stroke was estimated using the 2.10 Chinese population census data,and risk factors were analyzed by multiple imputation and *** The crude and standardized prevalence rates of stroke in patients with T2.M were 34.4%and 2..5%,respectively,and 85.2.of the stroke patients had ischemic *** half of the patients who experienced stroke had clusters of more than 4 risk *** with no-risk-factor clustering,the risk of stroke significantly increased 3-4 times in the presence of more than 4 risk-factor clusters(P1).Hypertension was the most common major risk factor for ischemic stroke[odds ratio(OR),2.34;95%confidence interval(CI),2.18-2.50]and hemorrhagic stroke(OR,3.68;95%CI 2.95-4.59;P1).Moreover,a 1-standard-deviation increase in fasting blood glucose(FBG)was significantly negatively correlated with ischemic stroke risk,and the same change in FBG was significantly associated with an 8%increased risk of hemorrhagic *** The prevalence of stroke in patients with T2.M is rather high,and the clustering of risk factors is associated with the development of stroke in T2.M *** factors differ in different stroke *** risk factors for a specific high-risk group is necessary.

关键词： type 2.diabetes mellitus stroke prevalence risk factor cluster

A data-driven approach for predicting the fatigue life and failure mode of self-piercing rivet joints

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Advances in Manufacturing 2024年第3期12卷 538-555页

作者： Jian wang Qiu-Ren chen Li Huang chen-Di Wei Chao Tong xian-hui wang Qing Liu Nanjing university of Science and Technology Nanjing210094People’s Republic of China Material Academy JitriSuzhou215100JiangsuPeople’s Republic of China Key Laboratory for Light-weight Materials Nanjing Tech UniversityNanjing210009People’s Republic of China xi’an Jiaotong-Liverpool university Suzhou215123JiangsuPeople’s Republic of China

In lightweight automotive vehicles,the application of self-piercing rivet(SPR)joints is becoming increasingly *** the importance of automotive service performance,the fatigue performance of SPR joints has received considerable ***,this study proposes a data-driven approach to predict the fatigue life and failure modes of SPR *** dataset comprises three specimen types:cross-tensile,cross-peel,and *** ensure data consistency,a finite element analysis was employed to convert the external loads of the different *** selection was implemented using various machine-learning algorithms to determine the model *** Gaussian process regression algorithm was used to predict fatigue life,and its performance was compared with different kernel functions commonly used in the *** results revealed that the Matern kernel exhibited an exceptional predictive capability for fatigue *** the data points,95.9%fell within the 3-fold error band,and the remaining 4.1%exceeded the 3-fold error band owing to inherent dispersion in the fatigue *** predict the failure location,various tree and artificial neural network(ANN)models were *** findings indicated that the ANN models slightly outperformed the tree *** ANN model accurately predicts the failure of joints with varying dimensions and ***,minor deviations were observed for the joints with the same ***,this data-driven approach provided a reliable predictive model for estimating the fatigue life and failure location of SPR joints.

关键词： Self-piercing rivet(SPR)joints Fatigue life prediction Failure mode prediction Machine learning

Engineering FeOOH/Ni(OH)_(2. heterostructures on Ni_(3)S_(2.surface to enhance seawater splitting

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Rare Metals 2024年第5期43卷 1989-1998页

作者： chen Yang Ya-Dong Li Li-Juan Cao xi-Long {2. Han-Pu Liang Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China

The construction of highly stable and efficient electrocatalysts is desirable for seawater splitting but remains challenging due to the high concentration of Cl-in ***,FeOOH/Ni(OH)_(2.heterostructure supported on Ni_(3)S_(2.-covered nickel foam(Fe–Ni/Ni_(3)S_(2./NF)was fabricated by hydrothermal and etching methods,as well as anodic oxidation *** electronic structure of FeOOH and Ni(OH)_(2.could be modulated after depositing FeOOH nanoparticles on Ni(OH)_(2.nanosheet,which greatly boosted the catalytic *** the catalyst used as an electrode for oxygen evolution reaction(OER),it needed low overpotentials of 2.6 and 368 m V to achieve current densities of 100 and 800 m A·cm^(-2.,respectively,in 1 mol·L^(-1)KOH+seawater *** can operate continuously at 100 m A·cm^(-2.for 400 h without obvious ***,in situ generated SO_(4)^(2.)from inner Ni_(3)S_(2.during electrolysis process would accumulate on the surface of active sites to form passivation layers to repel Cl^(-),which seemed to be responsible for superior *** study not only synthesizes an OER catalyst for highly selective and stable seawater splitting,but also gives a novel approach for industrial hydrogen production.

关键词： Anodic oxidation Heterostructure Oxygen evolution reaction Seawater splitting

Synthesis of Anti-Pancreatic Cancer Natural Product Majusculamide D and Analogues Reveals a Preliminary Structure-Activity Relationships

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Chinese Journal of Chemistry 2024年第6期42卷 605-610页

作者： xiuhe Zhao Mengxue Lv xiaonan xi Yaxin Lu Liang wang Yue chen The State Key Laboratory of Medicinal Chemical Biology College of PharmacyNankai UniversityTianjin300350 China College of Chemistry Nankai UniversityTianjin300071 China

The total synthesis of majusculamide D(1)was achieved from commercially available *** addition,we synthesized eight analogues including three stereoisomers of majusculamide D that differ in the fatty acid *** analogues including a simplified analogue 2. exhibited significant nanomolar-level IC50 values against Panc-1 cells in MTT assays.A preliminary SAR analysis indicated that the hydroxyl group at C10 and C2.C3 unsaturated double bond of majusculamide D were essential in maintaining the high activity against Panc-1 cells and the orientation of C40-Me and C42.Me groups was tolerable.

关键词： Majusculamide D Natural products SAR Anti-pancreatic cancer Lipopentapeptide

RpUGT344J7 is involved in the reproduction switch of Rhopalosiphum padi with holocyclic life cycle

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Insect Science 2024年第4期31卷 1073-1089页

作者： Suji wang Wenjie Huang Mengtian Li Ni wang {2. Liu Maohua chen {2.ong Peng State Key Laboratory of Crop Stress Biology for Arid Areas Key Laboratory of Plant Protection Resources and Pest Management of Ministry of EducationKey Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural AffairsCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi ProvinceChina

Many aphid species exhibit both cyclical parthenogenesis(CP)and the obligate parthenogenesis(OP)life history,which are genetically *** CP aphid lineages,the parthenogenetic individuals can switch from asexual to sexual reproduction quickly in response to environmental factors such as changes in photoperiod and ***,the OP aphid lineages do not undergo sexual reproduction under any *** far,mechanisms underlying the reproduction switch in CP aphids have not been fully *** padi,a serious worldwide insect pest of wheat,has both CP and OP *** diphosphate-glycosyltransferases(UGTs)are enzymes that participate in the metabolic detoxification of ***,we identified 43 RpUGT genes from *** genome and transcriptome sequences,and found that:(1)the UGT content of the CP lineage was significantly higher than that in the OP lineage at the key time points when CP lineage mainly produce virginoparae,gynoparae,and males under inducing condition,while there were no significant difference under normal conditions;(2.RpUGT344J7 gene was highly expressed during the time points when CP lineages produce gynopara and males;(3)the critical time points for CP lineages to produce virginoparaee,gynoparae,and males were affected when the CP lineages were injected with dsRpUGT344J7;(4)the knockdown of RpUGT344J7 caused a significant reduction in the total number of virginoparae,gynoparae,and males in the offspring under inducing *** findings contribute to our understanding of the molecular mechanisms underlying the quick shift from asexual to sexual reproduction in aphid species.

关键词： bird cherry-oat aphid cyclical parthenogenesis obligate parthenogenesis reproduction switch uridine diphosphate-glycosyltransferases(UGTs)

Quantitative effect of kerogen type on the hydrocarbon generation potential of Paleogene lacustrine source rocks,Liaohe Western Depression,China

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Petroleum Science 2024年第1期21卷 14-30页

作者： Sha-Sha hui xiong-Qi Pang Fu-Jie Jiang {2.-xi wang Shu-xing Mei Tao Hu Hong Pang Min Li xiao-Long Zhou Kan-Yuan Shi State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Exploration and Development Research Institute PetroChina Liaohe Oilfield CompanyPanjin 124010LiaoningChina

Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source *** source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organic carbon(TOC)content,various kerogen types,and a wide range of thermal ***,their hydrocarbon generation potential and resource estimation can be *** this study,geochemical tests,numerical analysis,hydrocarbon generation kinetics,and basin modeling were integrated to investigate the differential effects of kerogen types on the hydrocarbon generation potential of lacustrine source *** hydrocarbon generation and expulsion(HGE)models of different kerogen types were established quantitatively upon abundant Rock-Eval/TOC/vitrinite reflectance(R_(o))*** sets of good-excellent source rocks deposited in the fourth(Es4),third(Es3),and first(Es1)members of Paleogene Shahejie Formation,are predominantly types I-II_(1),II_(1)-II_(2.,and II-III,*** activation energy of types I-II_(2.kerogen is concentrated(180-2.0 kcal/mol),whereas that of type III kerogen is widely distributed(150-2.0 kcal/mol).The original hydrocarbon generation potentials of types I,II_(1),II_(2.,and III kerogens are 790,510,2.0,and 85 mg/g TOC,*** Ro values of the hydrocarbon generation threshold for type I-III source rocks gradually increase from 0.42.to 0.74%,and Ro values of the hydrocarbon expulsion threshold increase from 0.49%to 0.87%.Types I and II_(1)source rocks are characterized by earlier hydrocarbon generation,more rapid hydrocarbon expulsion,and narrower hydrocarbon generation windows than types II_(2.and III source *** kerogen types also affect the HGE history and resource *** types(conventional,tight,and shale oil/gas)and three levels(realistic,expected,and prospective)of hydrocarbon resources of different members in the Liaohe Western Depression are *** suggest that t

关键词： Kerogen type Hydrocarbon generation potential Lacustrine source rocks Liaohe western depression