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china Petroleum Processing & Petrochemical Technology 2024年第2期26卷 57-71页

作者： Zhao Wenjie Du Chengxin Song yu Zhou Yafen Wang Qing Zhou Limei Xu Bin Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry and Chemical EngineeringChina West Normal UniversityNanchongChina Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education Sichuan University of Science&EngineeringZigongChina

Organic-inorganic MoO_(3)/PI(MoPI)composites were prepared using a simple one-pot thermal copolymerization *** resulting composites exhibited enhanced photocatalytic activity for the selective oxidation of benzylamine to N-benzylidene benzylamine(N-BDBA)in ambient air under simulated solar light irradiation compared to pristine MoO_(3) or polyimide(PI).In particular,the MoPI composite with a 0.3:1 molar ratio of Mo to melamine,referred to as MoPI-0.3,demonstrated the best performance in the photo-oxidation of benzylamine,achieving a benzylamine conversion of 95%with a N-BDBA selectivity exceeding 99%after 3 h *** enhanced photocatalytic activity of the MoPI-0.3 catalyst was attributed to the formation of a direct Z-scheme heterojunction between MoO_(3) and PI,facilitating more efficient separation of the photoinduced electrons and ***,the MoPI-0.3 composite maintained considerably high activity over four consecutive cycles,highlighting its good stability and ***,the MoPI-0.3 composite could photo-oxidize benzylamine derivatives and heterocyclic amines to their corresponding imines,demonstrating the universal applicability of this composite catalyst.

关键词： MoO3/PI composite photocatalysis amine oxidation imine

Bioinspired zinc-mediated umpolung thiolation of alkyl electrophiles: reaction development, scope and mechanism

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Science china Chemistry 2024年第3期67卷 898-907页

作者： yuenian Xu Yan Zhang Yong Liu Wen-Wu Sun Jie Huang Hui he Yingjie Wu Wen Liu Shao-Fei Ni Xu-Qiong Xiao Xinxin Shao College of Material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material Technology of Ministry of EducationHangzhou Normal UniversityHangzhou 311121China School of Pharmaceutical Sciences South-Central Minzu UniversityWuhan 430074China Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guang-dong Province Shantou UniversityShantou 515063China

Zinc-promoted umpolung thiolation of alkyl electrophiles with masked sulfur transfer reagents in the absence of nickel or copper catalysis is described. This protocol proceeds via a SET process of Zn to electrophilic sulfur reagent followed by insertion of Zn into disulfide and nucleophilic thiolation, providing straightforward access to a wide range of alkyl sulfides with broad substrate scope. A neutral TMEDA-ligated four-coordinated zinc thiolate with tetrahedra geometry was synthesized, isolated and fully characterized by NMR, IR and X-ray analysis. More importantly, the chemical reactivity of this active intermediate has been investigated, enabling the construction of C-Se, C-Te, Sb-S and Bi-S bonds to prepare valuable sulfur-containing molecules and beyond.

关键词： umpolung thiolation C(sp^(3))-S bond formation masked sulfur reagents reductive coupling

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Survival Analysis of Patients Undergoing Intraoperative Contrast-enhanced Ultrasound in the Surgical Treatment of Malignant Glioma

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Current Medical Science 2024年第2期44卷 399-405页

作者： Xu CheN Ya-ni PENG Fang-ling CheNG Dan CAO An-yu TAO Jian CheN Department of Neurosurgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Urology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Medical Ultrasound Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Objective:Complete resection of malignant gliomas is often *** previous study indicated that intraoperative contrast-enhanced ultrasound(ICEUS)could aid in the detection of residual tumor remnants and the total removal of brain *** study aimed to investigate the survival rates of patients undergoing resection with or without the use of ICEUS and to assess the impact of ICEUS on the prognosis of patients with malignant ***:A total of 64 patients diagnosed with malignant glioma(WHO grade HI and IV)who underwent surgery between 2012 and 2018 were *** them,29 patients received *** effects of ICEUS on overall survival(OS)and progression-free survival(PFS)of patients were evaluated.A quantitative analysis was performed to compare ICEUS parameters between gliomas and the surrounding ***:The ICEUS group showed better survival rates both in OS and PFS than the control *** univariate analysis revealed that age,pathology and ICEUS were significant prognostic factors for PFS,with only age being a significant prognostic factor for *** multivariate analysis,age and ICEUS were significant prognostic factors for both OS and *** quantitative analysis showed that the intensity and transit time of microbubbles reaching the tumors were significantly different from those of microbubbles reaching the surrounding ***:ICEUS facilitates the identification of residual *** and ICEUS are prognostic factors for malignant glioma surgery,and use of ICEUS offers a better prognosis for patients with malignant glioma.

关键词： intraoperative contrast-enhanced ultrasound malignant glioma extent of resection survival prognosis

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面向高机动飞行的旋翼气动模型构建方法

机器人 2024年第4期46卷 385-396页

作者：包一峰谷丰杜心田于利何玉庆中国科学院沈阳自动化研究所机器人学国家重点实验室辽宁沈阳110016 中国科学院机器人与智能制造创新研究院辽宁沈阳110169 中国科学院大学北京100049

旋翼气动机理复杂、变量耦合严重,如何在线准确估计旋翼气动力是实现旋翼飞行机器人高机动安全自主飞行的关键问题之一。为此,本文提出了一种基于叶素动量理论的集成参数模型构建方法,结合参数集成的思想,将叶素动量模型中的叶素积分式... 详细信息

旋翼气动机理复杂、变量耦合严重,如何在线准确估计旋翼气动力是实现旋翼飞行机器人高机动安全自主飞行的关键问题之一。为此,本文提出了一种基于叶素动量理论的集成参数模型构建方法,结合参数集成的思想,将叶素动量模型中的叶素积分式简化为代数式,以提升计算效率并降低参数辨识的复杂度,同时保留旋翼诱导速度为状态变量,避免了近似悬停飞行状态假设,使模型能够适应高速高机动的飞行状态。基于实机机动飞行数据的仿真实验结果表明,该方法构建的模型相较于常见的集成参数模型和仅基于叶素动量理论的模型,整体旋翼气动合力预测误差分别同比降低20%和50%,且与仅基于叶素动量理论的模型相比计算效率提升显著。

关键词：旋翼无人机旋翼气动力叶素动量理论集成参数多旋翼无人机

Development status and research recommendations for thermal extraction technology in deep hot dry rock reservoirs

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Deep Underground Science and Engineering 2024年第3期3卷 317-325页

作者： Diquan Li Ning Li Jing Jia Hongguang yu Qinghu Fan Lichang Wang Ahmed Mohsen School of Geosciences and Info‐Physics Central South UniversityChangshaChina Downhole Service Company CNPC XiBu Drilling Engineering Company LimitedKaramayChina Shale Oil Reservoir Stimulation Sub‐Laboratory Key Laboratory of Reservoirs StimulationCNPCKaramayChina

Based on a comprehensive review of domestic and foreign literature, this article discusses the technical difficulties and development status of enhanced geothermal system(EGS) concerning the thermal energy extraction of deep hot dry rock(HDR) reservoirs and proposes suggestions for the research focus of numerical simulation of HDR reservoir stimulation. Additionally, it summarizes the existing methods and mainstream working fluids for HDR reservoir stimulation. The article emphasizes the significance of factors such as well location, production well depth, artificial fracture orientation, and complexity in optimizing the thermal production efficiency of the EGS. Furthermore, this article delves into a detailed discussion on the influence of fracture spacing, fracture permeability,fracture length, fluid injection rate, and injected fluid temperature on the performance of the EGS. In light of the thermo-hydro-mechanical coupling challenges associated with high-temperature reservoirs, it is suggested that future research efforts should focus on investigating the impact of thermo-induced stresses on the stability of the artificial fracture network within the EGS during long-term(>30 years) circulation of hot and cold fluids.

关键词： enhanced geothermal system hot dry rock reservoir thermoelastic stress thermo-hydro-mechanical coupling

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Deliberate self-harm among pediatric psychiatric inpatients in china:A single-center retrospective study

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World Journal of Psychiatry 2024年第3期14卷 398-408页

作者： Xing-Zhi Jiang Huan-Huan Li Zhen-Zhen yu Chen Wang Department of child and Adolescent Psychiatry Shenzhen Kangning HospitalShenzhen Mental Health CenterShenzhen Key Laboratory for Psychological Healthcare and Shenzhen Institute of Mental HealthShenzhen 518020Guangdong ProvinceChina Department of Psychiatry Xiamen Xianyue HospitalXiamen 361012Fujian ProvinceChina Department of Geriatric Medicine Dalian Medical UniversityDalian 116000Liaoning ProvinceChina Department of Neurology The Second Affiliated Hospital of Xiamen Medical CollegeXiamen 361000Fujian ProvinceChina Department of Neurology and Department of Neuroscience The First Affiliated Hospital of Xiamen UniversitySchool of MedicineXiamen UniversityXiamen 361000Fujian ProvinceChina

BACKGROUND For children and adolescents,deliberate self-harm(DSH)is becoming a mental health problem of *** several studies on the prevalence and factors of DSH in the world,there is little information on DSH among children and adolescents in *** study explores the prevalence,types,associated risk factors and tendency of DSH in pediatric psychiatric inpatients in *** To understand the situation of DSH among hospitalized children and adolescents and its related *** In this study,we retrospectively studied 1414 hospitalized children and adolescents with mental illness at Xiamen Mental health Center from 2014 to 2019,extracted the demographic and clinical data of all patients,and analyzed clinical risk factors of *** A total of 239(16.90%)patients engaged in at least one type of DSH in our ***(n=115,48.12%)was the most common type of ***(n=171,71.55%)were more likely to engage in DSH than males(n=68,28.45%).DSH was positively associated with depressive disorders[OR=3.845(2.196-6.732);Pchiatric illness[OR=7.767(2.952-20.433);Phe occurrence of DSH.

关键词： Deliberate self-harm children Adolescent Psychiatric inpatients Retrospective study

Robust Parameter Identification Method of Adhesion Model for heavy Haul Trains

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Journal of Transportation Technologies 2024年第1期14卷 53-63页

作者： Shuai Qian Lingshuang Kong Jing he College of Railway Transportation Hunan University of Technology Zhuzhou China College of Electronic Information and Electrical Engineering Changsha University Changsha China College of Electrical and Information Engineering Hunan University of Technology Zhuzhou China

A robust parameter identification method based on Kiencke model was proposed to solve the problem of the parameter identification accuracy being affected by the rail environment change and noise interference for heavy-duty trains. Firstly, a Kiencke stick-creep identification model was constructed, and the parameter identification task was transformed into a quadratic programming problem. Secondly, an iterative algorithm was constructed to solve the problem, into which a time-varying forgetting factor was added to track the change of the rail environment, and to solve the uncertainty problem of the wheel-rail environment. The Granger causality test was adopted to detect the interference, and then the weights of the current data were redistributed to solve the problem of noise interference in parameter identification. Finally, simulations were carried out and the results showed that the proposed method could track the change of the track environment in time, reduce the noise interference in the identification process, and effectively identify the adhesion performance parameters.

关键词： heavy-Duty Train Kiencke Model Quadratic Programming Time-Varying Forgetting Factor Granger Causality Test

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聚丙烯/热塑性弹性体复合绝缘材料介电性能

广东电力 2024年第9期37卷 56-64页

作者：余欣黄上师彭向阳姚驰吴吉程海涵何金良广东省电力装备可靠性企业重点实验室(广东电网有限责任公司电力科学研究院) 广东广州510080 清华大学电机工程与应用电子技术系北京100084

聚丙烯(PP)具有高温热稳定、工作温度高和电气绝缘强等优势,还可实现回收再利用,有望成为未来电缆绝缘的替代材料,但PP的机械性能还需通过增韧改性以满足电缆敷设的需求。对此,主要研究以热塑性弹性体苯乙烯乙烯丁二烯苯乙烯嵌段共聚物(... 详细信息

聚丙烯(PP)具有高温热稳定、工作温度高和电气绝缘强等优势,还可实现回收再利用,有望成为未来电缆绝缘的替代材料,但PP的机械性能还需通过增韧改性以满足电缆敷设的需求。对此,主要研究以热塑性弹性体苯乙烯乙烯丁二烯苯乙烯嵌段共聚物(SEBS)与PP进行共混,制备了不同组分配比的PP/SEBS复合材料,进行红外光谱、差式扫描、电阻率、击穿电场强度、介电谱和结构表征测试。测试结果表明,随着SEBS含量的增加,结晶度、直流体积电阻率和直流击穿电场强度均下降,介质损耗因子上升;形貌观察表明,随着SEBS含量的增加,SEBS在PP中的分散性变差,球晶边界也逐渐模糊,与结晶度下降现象一致。综合来说,PP与SEBS质量之比为60∶40的PP/SEBS具有较高的直流体积电阻率和直流击穿电场强度,质量之比为70∶30的PP/SEBS具有较低的介质损耗因子,可用于指导未来PP电缆绝缘材料的配比优化。

关键词：聚丙烯(PP) 热塑性弹性体苯乙烯乙烯丁二烯苯乙烯嵌段共聚物(SEBS) 介电性能

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Biomechanical behavior of grass roots at different gauge lengths

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Journal of Mountain Science 2024年第9期21卷 3201-3214页

作者： FU Jiangtao ZHOU Zhe GUO Hong ZHAO Jimei yu Dongmei WU Jie HU Xiasong School of Civil Engineering and Architecture Shaanxi University of TechnologyHanzhong 723000China Crop Science postdoctoral research station Qinghai UniversityXining 810016China School of Geological Engineering Qinghai UniversityXining 810016China Qinghai institute of Salt Lakes Chinese Academy of SciencesXining 810008China Department of Geographical Science Shaanxi University of TechnologyHanzhong 723000China

Gauge length influences the biomechanical properties of herbaceous roots such as tensile resistance,tensile strength and Young’s ***,the extent to which and how these biomechanical properties of herbaceous roots are influenced remain *** better understand the behavior of roots in tension under different conditions and to illustrate these behaviors,uniaxial tensile tests were conducted on the Poa araratica roots as the gauge length increased from 20 mm to 80 ***,ANOVA was used to test the impact of the significant influences of gauge length on the biomechanical properties,nonlinear regression was applied to establish the variation in the biomechanical properties with gauge length to answer the question of the extent to which the biomechanical properties are influenced,and Weibull models were subsequently introduced to illustrate how the biomechanical properties are influenced by gauge *** results reveal that(1)the variation in biomechanical properties with root diameter depends on both the gauge length and the properties themselves;(2)the gauge length significantly impacts most of the biomechanical properties;(3)the tensile resistance,tensile strength,and tensile strain at cracks decrease as the gauge length increases,with values decreasing by 20%-300%,while Young’s modulus exhibits the opposite trend,with a corresponding increase of 30%;and(4)the Weibull distribution is suitable for describing the probability distribution of these biomechanical properties;the Weibull modulus for both tensile resistance and tensile strain at cracks linearly decrease with gauge length,whereas those for tensile strength and Young’s modulus exhibit the opposite *** tensile resistance,tensile strength,and tensile strain at the cracks linearly decrease with increasing gauge length,while the tensile strength and Young’s modulus linearly increase with increasing gauge length.

关键词： Biomechanical properties of roots Weibull distribution ANOVA Uniaxial tensile test Linear regression

Student Academic Performance Predictive Model Based on Dual-stream Deep Network

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计算机科学 2024年第10期51卷 119-128页

作者： XIE Hui ZHANG Pengyuan DONG Zexiao YANG Huiting KANG Huan he Jiangshan CheN Xueli Center for Biomedical-photonics and Molecular Imaging Xi’an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life InformationSchool of Life Science and TechnologyXidian UniversityXi’an 710126China Engineering Research Center of Molecular and Neuro Imaging Ministry of EducationXi’an 710126China Innovation Center for Advanced Medical Imaging and Intelligent Medicine Guangzhou Institute of TechnologyXidian UniversityGuangzhou 510550China

Blended teaching is one of the essential teaching methods with the development of information *** a learning effect evaluation model is helpful to improve students’academic performance and helps teachers to better implement course ***,a lack of evaluation models for the fusion of temporal and non-temporal behavioral data leads to an unsatisfactory evaluation *** meet the demand for predicting students’academic performance through learning behavior data,this study proposes a learning effect evaluation method that integrates expert perspective indicators to predict academic performance by constructing a dual-stream network that combines temporal behavior data and non-temporal behavior data in the learning *** this paper,firstly,the Delphi method is used to analyze and process the course learning behavior data of students and establish an effective evaluation index system of learning behavior with universality;secondly,the Mann-Whitney U-test and the complex correlation analysis are used to analyze further and validate the evaluation indexes;and lastly,a dual-stream information fusion model,which combines temporal and non-temporal features,is *** learning effect evaluation model is built,and the results of the mean absolute error(MAE)and root mean square error(RMSE)indexes are 4.16 and 5.29,*** study indicates that combining expert perspectives for evaluation index selection and further fusing temporal and non-temporal behavioral features that for learning effect evaluation and prediction is rationality,accuracy,and effectiveness,which provides a powerful help for the practical application of learning effect evaluation and prediction.

关键词： Blended teaching Expert perspective indicators Two-stream information fusion model