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Flexible assistance strategy of lower limb rehabilitation exoskeleton based on admittance model

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Science China(Technological Sciences) 2024年第3期67卷 823-834页

作者： KOU JianGe WANG Yixuan CHEN ZhenLei SHI Yan GUO Qing xu meng School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China Department of Musculoskeletal Tumor Senior Department of Orthopedicsthe Fourth Medical Centerof PLA GeneralHospitalBeijing 100853China

Exercise training based on exoskeleton is an effective rehabilitation method for stroke patients. However, some rehabilitation exoskeletons still have poor wearable performance and obvious human-robot impedance during training, which easily cause secondary injuries to the patients. In this study, a variable admittance control strategy is proposed to improve the operator's wearable comfort, which can adapt to different operators by regulating admittance parameters. The admittance controller has two feedback loops: the position inner-loop and the admittance outer-loop. Meanwhile, the exoskeleton Lagrange model is constructed with unknown friction disturbance. By using Lyapunov technique and backstepping with state observer, the joint position error of exoskeleton is convergence into a zero neighborhood. The effectiveness of the proposed admittance controller is verified by both simulation and experiment. The tracking error of hip and knee joint is less than 4 degrees while the human-robot interaction torque is constrained in a tolerable range of the operator.

关键词： human-robot interaction exoskeleton backstepping admittance control

Metal–organic framework wafer enabled fast response radiation detection with ultra-low dark current

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Nano Research 2024年第4期17卷 2988-2993页

作者： meng xu Jianxi Liu Wei Wu Yang Chen Donghao Ma Sixin Chen Wanqi Jie menghua Zhu Yadong xu State Key Laboratory of Solidification Processing MIIT Key Laboratory of Radiation Detection Materials and Devices&School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

Semiconductive metal–organic frameworks(MOFs)have attracted great interest for the electronic ***,dark currents of present hybrid organic–inorganic materials are 1000–10,000 times higher than those of commercial inorganic detectors,leading to poor charge ***,we demonstrate a ZIF-8(Zn(mim)_(2),mim=2-methylimidazolate)wafer with ultra-low dark current of 1.27 pA·mm^(-2) under high electric fields of 322 V·mm^(-1).The isostatic pressing preparation process provides ZIF-8 wafers with good ***,the presence of redox-active metals and small spatial separation between components promotes the charge *** ZIF-8-based semiconductor detector shows promising X-ray detection sensitivity of 70.82μC·Gy^(-1)·cm^(-2) with low doses exposures,contributing to superior X-ray imaging capability with a relatively high spatial resolution of 1.2 lp·mm^(-1).Simultaneously,good peak discrimination with the energy resolution of~43.78%is disclosed when the detector is illuminated by uncollimated 241Am@5.48 MeVα-*** results provide a broad prospect of MOFs for future radiation detection applications.

关键词： MOFs lead-free α-particles X-ray detection and imaging dark current fast response

Mediated electron transfer process in α-MnO_(2)catalyzed Fenton-like reaction for oxytetracycline degradation

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Chinese Chemical Letters 2024年第8期35卷 367-372页

作者： Yiqian Jiang Zihan Yang Xiuru Bi Nan Yao Peiqing Zhao xu meng State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

In Fenton-like oxidation,the catalyst directly influences the reaction mechanism for the degradation of pollutants from ***,a α-MnO_(2)catalyst(OAm-1)was synthesized via a self-assembly method with the assistance of a ***-1 possessed a large specific surface area of_(2)21 m2/g,abundant mesoporous structures and a large proportion of Mn(III).Further characterization exhibited that OAm-1 had abundant oxygen vacancies and excellent reducibility and *** adsorption and catalytic ability of OAm-1 were studied in the degradation of oxytetracycline(OTC)via the activation of hydrogen peroxide(H_(2)O_(2)).Through the radical quenching experiments,electron resonance spectroscopy(EPR),X-ray photoelectron spectroscopy(XPS)and Fourier-transform infrared spectroscopy(FT-IR)analysis,Mn(III)of OAm-1 was proved to be the active sites for the chemisorption of *** electrochemical ex-periments and analysis have shown that a process of electron transfer mediated by OAm-1 occurred be-tween the pollutant and H_(2)O_(2)during a Fenton-like *** work experimentally verifies the elec-tron transfer process dominated nonradical mechanism overα-MnO_(2),which is helpful for understanding the catalytic mechanism of the Fenton-like oxidation.

关键词： Mediated electron transfer Hydrogen peroxide Oxidative degradation Manganese oxide Fenton oxidation

剪切增稠幂律流体中单气泡上升动力学行为的格子Boltzmann方法研究

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物理学报 2024年第13期73卷 190-200页

作者：许鑫萌娄钦上海理工大学能源与动力工程学院上海200093

采用不可压非牛顿气液两相流格子Boltzmann方法研究了剪切增稠流体中气泡上升的动力学行为,重点分析了流变指数n、Eoυos数(Eo)和Galilei数(Ga)对气泡形变、终端速度和剪切速率的影响.数值结果表明:气泡形变程度随Eo的增大而增大,n对气... 详细信息

采用不可压非牛顿气液两相流格子Boltzmann方法研究了剪切增稠流体中气泡上升的动力学行为,重点分析了流变指数n、Eoυos数(Eo)和Galilei数(Ga)对气泡形变、终端速度和剪切速率的影响.数值结果表明:气泡形变程度随Eo的增大而增大,n对气泡形状的影响与Ga相关.另一方面,随着Ga增大,气泡终端速度随n呈非线性单调增大,且n对终端速度的影响随Ga的增大逐渐明显;当Ga固定且值较小时,气泡终端速度在较小Eo下随n的增大先增大后减小,而当Eo较大时终端速度随n的增大呈增大趋势;当Ga固定且较大时,气泡终端速度在Eo较大时较为统一地随n增大而增大.此外,气泡左右两端存在剪切速率较高的区域,该区域尺寸随Eo,Ga的增大而增大,随n的增大先增大后缩小.最后利用正交试验法得到上述三变量对剪切速率和终端速度的影响程度.对于剪切速率,参数影响程度由大到小的顺序依次为n,Ga和Eo;对于终端速度,Ga对其影响最大,n次之,Eo影响程度最小.

关键词：格子Boltzmann方法气泡动力学剪切增稠流体

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水稻高温热害强度时空变化特征与预报模型构建

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农业工程学报 2024年第10期40卷 97-106页

作者：徐敏徐经纬徐萌徐忆菲江苏省气候中心南京210019 南京信息工程大学大气科学学院南京210044 金坛国家气候观象台金坛213200

构建定量表征水稻高温热害强度的指数,揭示时空变化特征,并建立中长期预报模型,准确预报高温热害发生的强度趋势对提前部署抗高温工作至关重要。该研究充分考虑高温热害累积效应,结合致灾指标,构建了强度指数,并采用Fisher分割法对其进... 详细信息

构建定量表征水稻高温热害强度的指数,揭示时空变化特征,并建立中长期预报模型,准确预报高温热害发生的强度趋势对提前部署抗高温工作至关重要。该研究充分考虑高温热害累积效应,结合致灾指标,构建了强度指数,并采用Fisher分割法对其进行了客观化分级;根据中长期天气预报原理,基于海温和大气环流指数两类预报因子,利用二维寻优技术,分别构建了水稻高温热害强度指数预报模型,并进行了验证和比较。结果表明:1)2010年以来江苏省水稻高温热害年频次增加且强度明显增强,其中2013年、2022年高温热害强度均达最高等级4级,高温热害强度指数存在明显的年代际差异,从20世纪90年代开始江苏省水稻高温热害强度逐年代增强,空间上呈现出高温热害强度指数年代累加值不低于10的区域从南向北随年代逐步扩大,至21世纪10年代已扩展至淮北西部,其中淮河以南水稻高温热害强度增强明显,为历年代最强。2)构建的两类水稻高温热害强度指数预报模型可在7月初进行预报,预报提前量均为1~2个月,总体都能较好地模拟出强度指数的年际波动特征,但模拟值波动幅度与实际值存在不同程度的差异。3)通过拟合检验和试报检验,预报因子经过最优化相关技术处理后,能有效增加因变量和自变量的相关度,提高预报模型的模拟效果,其中海温因子经最优化处理后的高温热害强度指数预报模型效果最佳,可在农业气象业务服务中进行应用。研究结果对主动防御高温灾害和保障粮食安全具有重要科学意义和参考价值。

关键词：预报强度指数水稻高温热害二维寻优海温大气环流指数

Systemic inflammatory response index is a predictor of prognosis in gastric cancer patients: Retrospective cohort and meta-analysis

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 382-395页

作者： Jing-Yao Ren meng xu Xiang-Dong Niu Shi-xun Ma Ya-Jun Jiao Da Wang Miao Yu Hui Cai School of Clinical Medicine Ningxia Medical UniversityYinchuan 750000Ningxia Hui autonomous regionChina Gansu Provincial Hospital Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina General Surgery Clinical Medical Center Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Medical College of Jiangsu University Jiangsu UniversityZhenjiang 212013Jiangsu ProvinceChina Key Laboratory of Molecular Diagnostics and Precision Medicine for Surgical Oncology in Gansu Province Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina

BACKGROUND The systemic inflammatory response index(SIRI)has been demonstrated to make a significant difference in assessing the prognosis of patients with different solid ***,research is needed to ascertain the accuracy and reliability of applying the SIRI to patients who undergo robotic radical gastric cancer *** To validate the applicability of the SIRI in assessing the survival of gastric cancer patients and evaluate the clinical contribution of preoperative SIRI levels to predicting long-term tumor outcomes in patients,who received robotic radical gastric cancer *** Initially,an exhaustive retrieval was performed in the PubMed,the Cochrane Library,EMBASE,Web of Science,and Scopus databases to identify relevant ***,a meta-analysis was executed on 6 cohort studies iden-tifying the value of the SIRI in assessing the survival of gastric cancer ***,the clinical data of 161 patients undergoing robotic radical gastric cancer surgery were retrospectively analyzed to evaluate their clinicopathological characteristics and relevant laboratory *** association between preoperative SIRI levels and 5-year overall survival(OS)and disease-free survival(DFS)was *** The findings demonstrated an extensive connection between SIRI values and the outcome of patients with gastric *** SIRI levels were identified as an independent hazard feature for both OS and DFS among those who received robotic surgery for gastric *** levels in gastric cancer patients were observed to be associated with the presence of comorbidities,T-stage,carcinoembryonic antigen levels,the development of early serious postoperative complications,and the rate of lymph node *** SIRI values are correlated with adverse in the gastric cancer population and have the potential to be utilized in predicting long-term oncological survival in patients who undergo robotic radical gastric canc

关键词： Systemic inflammatory response index Prognosis Gastric cancer Complications Meta-analysis

Exploring the Impact of Alcohol Consumption and Smoking on Primary Open Angle Glaucoma: A Mendelian Randomization Study

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American Journal of Molecular Biology 2024年第3期14卷 152-165页

作者： meng xu Longlong Chen Dongkan Li Bin Lin Xiamen Eye Center and Eye Institute of Xiamen University Xiamen China Xiamen Clinical Research Center for Eye Diseases Xiamen China Xiamen Key Laboratory of Ophthalmology Xiamen China Fujian Key Laboratory of Corneal & Ocular Surface Diseases Xiamen China Xiamen Key Laboratory of Corneal & Ocular Surface Diseases Xiamen China Translational Medicine Institute of Xiamen Eye Center of Xiamen University Xiamen China

Objective: Utilizing Mendelian Randomization, this study employs Single Nucleotide Polymorphisms (SNPs) as instrumental variables to explore the causal relationships between bibulosity, smoking, and Primary Open Angle Glaucoma (POAG). Methods: GWAS data for bibulosity, smoking, and POAG were obtained from the Social Science Genetic Association Consortium website and the IEU OpenGWAS Project website, respectively. Using a P-value threshold of −8, a linkage disequilibrium coefficient (r2) of 0.001, and a linkage disequilibrium region width of 10,000 kb, the data were aggregated, resulting in 6 SNPs for bibulosity and 253 SNPs for smoking. Three regression models, MR-Egger, Weighted Median Estimator (WME), and Random-Effects Inverse-Variance Weighted (IVW) were applied to analyze the causal impact of bibulosity and smoking on POAG. Results: The GWAS data for alcohol consumption and smoking were derived from European populations, while the GWAS data for Primary Open-Angle Glaucoma (POAG) were sourced from East Asian populations, with no gender restrictions. Analysis using three different regression models revealed that neither excessive alcohol consumption nor smoking significantly increased the risk of developing POAG. Specifically, the odds ratios with 95% confidence intervals for the alcohol consumption group were 0.854 (0.597 - 1.221) in MR-Egger regression, 0.922 (0.691 - 1.231) in WME regression, and 0.944 (0.711 - 1.252) in IVW regression. For the smoking group, the odds ratios were 1.146 (0.546 - 2.406) in MR-Egger regression, 0.850 (0.653 - 1.111) in WME regression, and 0.939 (0.780 - 1.131) in IVW regression. Given the significant heterogeneity in the SNPs associated with smoking, the focus was primarily on the results from the IVW regression model. Conclusion: Alcohol consumption and smoking are not significant risk factors for the development of POAG.

关键词： Alcohol Abuse Smoking Glaucoma Causal Relationship Mendelian Randomization

Medcheck:A novel software for automated de-formulation of traditional Chinese medicine(TCM)prescriptions by liquid chromatography-mass spectrometry

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Journal of Pharmaceutical Analysis 2024年第6期14卷 930-932页

作者： Xiao-lan Li Jian-qing Zhang Yun Li xuan-jing Shen Huan-ya Yang Lin Yang meng xu Qi-rui Bi Chang-liang Yao De-an Guo Shanghai Research Center for Modernization of Traditional Chinese Medicine National Engineering Research Center of TCM Standardization TechnologyShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China b University of Chinese Academy of Sciences Beijing100049China

Prescriptions are the main clinical application of traditional Chinese medicines(TCMs).Common forms include Chinese patent medicines,Kampo formulas,and hospital decoctions.A new pre-scription called“famous classical formulas”is recently developed and expected to boom in the *** constituent me-dicinal plants in prescriptions is critical for new drug development and quality control[1],which could avoid safety issues from adulteration or substandard ingredients,as seen in the notorious Longdan Xiegan Pill event.

关键词： medicines formulation prescription

Discovery of scheelite in the Zaozigou gold deposit of West Qinling Orogen,Northwest China and its implications for ore genesis

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China Geology 2024年第3期7卷 586-588页

作者： meng-xu Guo Jia-jun Liu De-gao Zhai Guo-ming Weng Rui Zhu State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences and ResourcesChina University of Geosciences(Beijing)Beijing 100083China Zaozigou Gold Mine Zhaojin Mining Industry Co.Ltd.Hezuo 747000China

*** The West Qinling Orogen extends east-west over 1500 km and is endowed with dozens of large-super large scale gold *** Zaozigou gold deposit has a proven reserve of 134 t with an average grade of 3.08 g/t thus is one of the largest deposits in the West Qinling ***,whether the fluid type is metamorphic or magmatichydrothermal and ore-formation processes of the Zaozigou gold deposit are *** is a ubiquitous accessory mineral in geologically diverse ore-deposit types and attested to be a strong indicator of ore-forming conditions and oredeposit genesis.

关键词： deposit gold Qinling