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Improvement of Ga_(2)O_(3)vertical Schottky barrier diode by constructing NiO/Ga_(2)O_(3)heterojunction

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Journal of Semiconductors 2024年第4期45卷 63-68页

作者： Xueqiang Ji Jinjin Wang Song qi Yijie Liang Shengrun Hu Haochen Zheng Sai Zhang Jianying Yue xiaohui qi Shan Li Zeng Liu Lei Shu Weihua Tang Peigang Li School of Integrated Circuits&State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China College of Integrated Circuit Science and Engineering Nanjing University of Posts and TelecommunicationsNanjing 210023China Beijing Microelectronics Technology Institute Beijing 100076China

The high critical electric field strength of Ga_(2)O_(3)enables higher operating voltages and reduced switching losses in power electronic devices.Suitable Schottky metals and epitaxial films are essential for further enhancing device performance.In this work,the fabrication of vertical Ga_(2)O_(3)barrier diodes with three different barrier metals was carried out on an n--Ga_(2)O_(3)homogeneous epitaxial film deposited on an n+-β-Ga_(2)O_(3)substrate by metal-organic chemical vapor deposition,excluding the use of edge terminals.The ideal factor,barrier height,specific on-resistance,and breakdown voltage characteristics of all devices were investigated at room temperature.In addition,the vertical Ga_(2)O_(3)barrier diodes achieve a higher breakdown volt-age and exhibit a reverse leakage as low as 4.82×10^(-8)A/cm^(2)by constructing a NiO/Ga_(2)O_(3)heterojunction.Therefore,Ga_(2)O_(3)power detailed investigations into Schottky barrier metal and NiO/Ga_(2)O_(3)heterojunction of Ga_(2)O_(3)homogeneous epitaxial films are of great research potential in high-efficiency,high-power,and high-reliability applications.

关键词： Ga_(2)O_(3) Schottky barrier diode NiO/Ga_(2)O_(3)heterojunction

Analysis of the Current Situation and Influencing Factors of Social Isolation Among the Elderly in the Community

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Proceedings of Anticancer Research 2024年第3期8卷 150-156页

作者： Weiwei Dong xiaohui qi Jialiang Wang Dongmei Cui Yanling Li Shaohua Li Physical Examination Center Affiliated Hospital of Hebei UniversityBaoding 071000Hebei ProvinceChina Departement of Respiratory and Critical Care Medicine Affiliated Hospital of Hebei UniversityBaoding 071000Hebei ProvinceChina Department of Neurosurgery Affiliated Hospital of Hebei UniversityBaoding 071000Hebei ProvinceChina Departement of Nursing Affiliated Hospital of Hebei UniversityBaoding 071000Hebei ProvinceChina Departement of Neonatology Affiliated Hospital of Hebei UniversityBaoding 071000Hebei ProvinceChina

Objective: To investigate the current situation of social isolation among the elderly in the community, and to analyze its influencing factors. Methods: A total of 265 elderly people were selected to conduct the survey using the general information questionnaire and the Chinese version of the social isolation scale for the elderly. Results: The social isolation score of the elderly was (20.15 ± 0.23). Factors such as age, education level, economic status, and social participation ability influenced the social isolation score (P < 0.05). Conclusion: The social isolation of the elderly is more serious, and the social isolation can be alleviated by improving the level of education and the economic situation and strengthening social participation.

关键词： Community Elderly Social isolation

Stability analysis of linear/nonlinear switching active disturbance rejection control based MIMO continuous systems

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Journal of Systems Engineering and Electronics 2021年第4期32卷 956-970页

作者： WAN Hui qi xiaohui LI Jie Department of Unmanned Aerial Vehicle Engineering Army Engineering University of PLAShijiazhuang 050003China The 32nd Research Institute China Electronics Technology Group CorporationShanghai 201800China

In this paper,a linear/nonlinear switching active disturbance rejection control(SADRC)based decoupling control approach is proposed to deal with some difficult control problems in a class of multi-input multi-output(MIMO)systems such as multi-variables,disturbances,and coupling,etc.Firstly,the structure and parameter tuning method of SADRC is introduced into this paper.Followed on this,virtual control variables are adopted into the MIMO systems,making the systems decoupled.Then the SADRC controller is designed for every subsystem.After this,a stability analyzed method via the Lyapunov function is proposed for the whole system.Finally,some simulations are presented to demonstrate the anti-disturbance and robustness of SADRC,and results show SADRC has a potential applications in engineering practice.

关键词： linear/nonlinear switching active disturbance rejection control(SADRC) multi-input multi-output(MIMO)continuous system decoupling control stability analysis

Direction navigability analysis of geomagnetic field based on Gabor filter

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Journal of Systems Engineering and Electronics 2018年第2期29卷 378-385页

作者： XIAO Jing DUAN Xiusheng qi xiaohui WANG Jianchen Army Engineering University Shijiazhuang 050003China Government Representative Office Northwestern Polytechnical UniversityXi’an 710065China

Direction navigability analysis is a supplement to the navigability analysis theory, in which extraction of the direction suitable-matching features(DSMFs) determines the evaluation performance. A method based on the Gabor filter is proposed to estimate the direction navigability of the geomagnetic field. First,the DSMFs are extracted based on the Gabor filter’s responses.Second, in the view of pattern recognition, the classification accuracy in fault diagnosis is introduced as the objective function of the hybrid particle swarm optimization(HPSO) algorithm to optimize the Gabor filter’s parameters. With its guidance, the DSMFs are extracted. Finally, a direction navigability analysis model is established with the support vector machine(SVM), and the performances of the models under different objective functions are discussed. Simulation results show the parameters of the Gabor filter have a significant influence on the DSMFs, which, in turn, affects the analysis results of direction navigability. Moreover, the risk of misclassification can be effectively reduced by using the analysis model with optimal Gabor filter parameters. The proposed method is not restricted in geomagnetic navigation, and it also can be used in other fields such as terrain matching and gravity navigation.

关键词： geomagnetic navigation navigability analysis direction navigability Gabor filter direction suitable-matching feature

Assembly and Post-modification of Fe3O4@MIL-100（Fe） for Knoevenagel Condensation

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Chemical Research in Chinese Universities 2018年第4期34卷 655-660页

作者： ZHANG Yanmei ZHANG Fan ZHANG Xiang XU Yingmei qi xiaohui QUAN Chunshan Key Laboratory of Biotechnology and Bioresources Utilization Ministry of Education College of Life Science Dalian Minzu University Dalian 116600 P. R. China

Many efforts have been devoted to the integration of magnetic nanoparticles and metal organic frame- works, which makes it easy and simple to separate the nano-sized metal organic frameworks from liquid phase. Amino-functionalized magnetic metal organic frameworks[Fe3O4@MIL-100（Fe）-NH2] were prepared by a stepwise assembly method followed by post-modification with electron-rich reagent. This magnetic catalyst was characterized by means of X-ray diffraction（XRD）, transmission electron microscopy（TEM）, scanning electron micrnscopy（SEM） and nitrogen adsorption, and tested in Knoevenagel condensation as a base catalyst. The magnetic catalyst exhibits a core-shell structure and can afford a high activity for the Knoevenagel condensation due to its bifunctional property and reduced diffusion limitation. Furthermore, it could be recovered magnetically and recycled three times. Although activity loss was observed in the recycle experiments, it could be reactivated by dispersing in a fresh modifier solution.

关键词： Fe3O4 MIL-100（Fe） Heterogeneous catalyst Knoevenagel condensation Magnetic separation

Chemical Characteristics and Anticoagulant Activities of Two Sulfated Polysaccharides from Enteromorpha linza (Chlorophyta)

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Journal of Ocean University of China 2013年第1期12卷 175-182页

作者： qi xiaohui MAO Wenjun CHEN Yin CHEN Yanli ZHAO Chunqi LI Na WANG Chunyan Key Laboratory of Marine Drugs Ministry of Education Institute of Marine Drug and Food Ocean University of China

Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester (19.0%) and uronic acid (14.9%). The MP mainly consisted of (1→4)-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of (1→3, 4)-linked rhamnose, (1→2, 4)-linked rhamnose, (1→4)-linked glucuronic acid and (1→4)-linked xylose residues. The SP contained abundant (1→4)-linked rhamnose with minor amounts of (1→3)-linked rhamnose, (1→3, 4)-linked rhamnose, (1→2, 4)-linked rhamnose, (1→4)-linked glucuronic acid, (1→4)-linked xylose, and (1→3)-linked galactose residues. The sulfate groups were mainly located at C-3 of (1→4)-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.

关键词：硫酸多糖抗凝血活性海洋绿藻活化部分凝血活酶时间化学特征葡萄糖醛酸凝血酶原时间 APTT

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机动车尾气污染与防治措施分析

黑龙江环境通报 2024年第5期37卷 96-98页

作者：齐晓辉段晨斐陕西聚光环保科技有限公司陕西宝鸡721000

随着我国经济水平飞速发展,汽车行业更加多元化起来,但随之而来的是机动车尾气带来的困扰与危害。本文主要围绕机动车尾气污染与防治措施进行探究。首先,阐述了机动车尾气中的CO、铅、颗粒物和碳氢化合物的危害。然后,分析了目前我国防... 详细信息

随着我国经济水平飞速发展,汽车行业更加多元化起来,但随之而来的是机动车尾气带来的困扰与危害。本文主要围绕机动车尾气污染与防治措施进行探究。首先,阐述了机动车尾气中的CO、铅、颗粒物和碳氢化合物的危害。然后,分析了目前我国防治机动车尾气污染的现状,包括监管体系不够完善、燃油标准不达标和制造工艺问题等方面的不足之处。最后,提出了机动车尾气污染的防治措施,包括增强环保意识、加强政府监管和优化产业生产格局等。本文旨在有效控制和减少机动车尾气污染,保护环境和人类健康。

关键词：机动车尾气污染颗粒物铅

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环境检测技术应用中存在的问题及对策分析

黑龙江环境通报 2024年第4期37卷 61-63页

作者：段晨斐齐晓辉陕西聚光环保科技有限公司陕西宝鸡721000

随着人们对环境质量和健康的关注度不断提高,环境检测技术成为评估和监测环境中污染物和有害物质的重要手段。然而,尽管环境检测技术在保护环境和健康方面发挥着重要作用,但其应用也面临着一些挑战和问题。为了解决这些问题并进一步提... 详细信息

随着人们对环境质量和健康的关注度不断提高,环境检测技术成为评估和监测环境中污染物和有害物质的重要手段。然而,尽管环境检测技术在保护环境和健康方面发挥着重要作用,但其应用也面临着一些挑战和问题。为了解决这些问题并进一步提高环境检测技术的准确性和可靠性,需要探讨并采取相应的对策。本文将分析环境检测技术存在的问题,并提出一些针对性的对策,以期推动环境检测技术的发展与应用。

关键词：环境检测技术问题对策

三维酰胺质子转移成像在原发性肝癌临床扫描可行性及图像质量评估中的初步研究

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磁共振成像 2024年第3期15卷 163-169页

作者：齐晓辉王琦沈智威段梦婷刘响潘江洋范雪丽贾丽涛王亚宁杜煜河北医科大学第四医院CT/MRI科石家庄050000 飞利浦(中国)投资有限公司北京100600

目的评估参数优化的三维酰胺质子转移加权(3 dimensions-amide proton transfer weighted,3D-APTw)成像在原发性肝癌扫描中的图像质量并分析其临床扫描的可行性。材料与方法前瞻性招募2020年10月至2022年2月临床怀疑原发性肝癌患者,共... 详细信息

目的评估参数优化的三维酰胺质子转移加权(3 dimensions-amide proton transfer weighted,3D-APTw)成像在原发性肝癌扫描中的图像质量并分析其临床扫描的可行性。材料与方法前瞻性招募2020年10月至2022年2月临床怀疑原发性肝癌患者,共109例。采用飞利浦3.0 T MRI设备进行扫描,分别采集T1WI、T2WI、弥散加权成像、酰胺质子转移加权(amide proton transfer weighted,APTw)及多期增强图像。机器自动生成经过B0校正的肝脏APTw图像。计算3D-APTw成像的扫描成功率及计算成功率。采用Kendall一致性系数对观察者内及观察者间主观评分进行一致性分析,对主观评分3分以上的病例测量3D-APTw图像的信噪比(signal-to-noise ratio,SNR)、肿瘤对比噪声比(contrast-to-noise ratio,CNR)、肿瘤及肝实质的APTw值并计算各参数值的变异系数,采用组内相关系数进行观察者内及观察者间可重复性测量的一致性分析。结果 109例患者中有11例患者3D-APTw图像中病变区域存在信号缺失,扫描成功率为89.91%(98/109),剩余98例患者中78例3D-APTw图像的主观评分为3分以上,计算成功率为71.56%(78/109)。观察者内及观察者间图像质量主观评分一致性分别为0.771和0.692,P<0.01。肿瘤组织APTw值观察者内及观察者间ICC分别为0.822和0.811,肝实质APTw值、SNR及CNR观察者ICC分别为0.675、0.634、0.666,肝实质APTw值、SNR及CNR观察者间ICC分别为0.614、0.290、0.560。肿瘤组织APTw值高于肝实质[(2.55±0.08)%vs.(1.45±0.07)%],两者间差异有统计学意义(P<0.001)。肿瘤组织和肝实质APTw值的变异系数分别为30.40%和44.40%。SNR和CNR为25.92±18.50和3.35±3.20。SNR变异系数为71.40%,CNR变异系数为90.00%。结论参数优化后的3D-APTw成像可以用于原发性肝癌的临床扫描,但容易受呼吸运动、胆囊或血管的影响而出现信号缺失或伪影,在参数设置及成像技术上仍有需要改进和提高的空间,以进一步优化其图像质量。

关键词：原发性肝癌诊断可行性图像质量三维酰胺质子转移成像磁共振成像