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Modulation doping of p-type Cu_(12)Sb_(4)S_(13)toward improving thermoelectric performance

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Journal of Materials Science & Technology 2024年第4期171卷 71-79页

作者： khak ho lim Mingquan Li Yu Zhang Yue Wu Qimin Zhou Qingyue Wang Xuan Yang Pingwei Liu Wen-Jun Wang Ka Wai Wong Ka Ming Ng Yu Liu Andreu Cabot Institute of Zhejiang University-Quzhou Quzhou 324000China College of Chemical and Biological Engineering Zhejiang UniversityHangzhou 310007China School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China Materials Research Institute The Pennsylvania State UniversityUniversity ParkPA 16802USA Ostia Technologies limited United Kingdom Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayHong KongChina ICREA Pg.Lluis Companys 23Barcelona 08010Spain Catalonia Energy Research Institute-IREC Sant Adria del BesosBarcelona 08930Spain

The commercial viability of thermoelectric(TE)devices relies heavily on two factors:cost reduction and efficiency *** this study,we first produce p-type Cu_(12)Sb_(4)S_(16-x)(x=0,3,4)using a low-temperature bottom-up approach and demonstrate Cu_(12)Sb_(4)S_(13)to show the best TE performance among the three tested ***,the TE energy conversion efficiency of Cu_(12)Sb_(4)S_(13)is further enhanced by optimizing its electronic band structure through the incorporation of small amounts of *** an optimal Te content of 5 mol%,more than a twofold increase in the TE figure of merit(zT)is *** gain insight into the mechanism of improvement on the transport properties of the mate-rial,we compare the interphase transport mechanism by incorporating nanodomains of different metals(Ag and Cu)into the Cu_(12)Sb_(4)S_(13)*** improved electrical conductivity obtained with Cu_(12)Sb_(4)S_(13)-Te nanocomposites is attributed to a charge flooding of the Cu_(12)Sb_(4)S_(13)*** contrast,excessive down-ward band-bending at the interphases of Ag/Cu metal-semiconductor drastically reduces the electrical ***,a weighted mobility(μw)analysis shows a dominant thermal activation of carri-ers in Cu_(12)Sb_(4)S_(13)-Te *** this material,a strong decrease in lattice thermal conductivity is also found,which is associated with a phonon-carrier scattering *** work shows the impor-tance of proper band-engineering in TE nanocomposites to decouple electrical and thermal transport to enhance TE performance,and the efficacy ofμw for electrical and thermal transport analysis.

关键词： Modulation doping Thermoelectric Interphase transport Charge flooding Phonon-carrier scattering

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自由基聚合反应动力学常数测定技术

化工学报 2023年第2期74卷 559-570页

作者：李雨萧王青月 lim khak ho 李晓辉 Mastan Erlita 彭博王文俊浙江大学工程师学院衢州分院浙江衢州324000 浙江大学衢州研究院浙江衢州324000 巴斯夫新材料有限公司上海200137 浙江大学化学工程联合国家重点实验室浙江杭州310027

自由基聚合是一类重要的聚合反应,其反应动力学常数的获取对于聚合机理研究、聚合物链结构定制、反应过程调控都有着重要的意义。综述了自由基聚合中最重要的链增长和链终止反应速率常数的测定方法,着重介绍连续脉冲激光引发结合凝胶渗... 详细信息

自由基聚合是一类重要的聚合反应,其反应动力学常数的获取对于聚合机理研究、聚合物链结构定制、反应过程调控都有着重要的意义。综述了自由基聚合中最重要的链增长和链终止反应速率常数的测定方法,着重介绍连续脉冲激光引发结合凝胶渗透色谱测定链增长反应速率常数、单脉冲-连续脉冲激光耦合结合近红外光谱与电子顺磁共振波谱测定链终止反应速率常数,涵盖了各方法的检测原理、要求和适用条件,讨论了增长自由基链长对链增长和链终止反应速率常数的影响。此外,对链增长和链终止反应速率常数检测方法的提升和新方法的开发进行了展望。

关键词：自由基聚合链增长速率常数链终止速率常数连续脉冲激光引发聚合单脉冲-连续脉冲耦合

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Prediction of product roughness,profile,and roundness using machine learning techniques for a hard turning process

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Advances in Manufacturing 2021年第2期9卷 206-215页

作者： Chunling Du Choon lim ho Jacek Kaminski Advanced Remanufacturing and Technology Center(ARTC) Agency for ScienceTechnology and Research(A*STAR)Singapore

High product quality is one of key demands of customers in the field of manufacturing such as computer numerical control(CNC)*** monitoring and prediction is of great importance to assure high-quality or zero defect *** this work,we consider roughness parameter Ra,profile deviation Pt and roundness deviation RONt of the machined products by a ***,these three parameters are much related to the machine spindle parameters of preload,temperature,and rotations per minute(RPMs),while in this paper,spindle vibration and cutting force are taken as inputs and used to predict the three quality *** spectral density(PSD)based feature extraction,the method to generate compact and well-correlated features,is proposed in details in this *** the efficient features,neural network based machine learning technique turns out to be able to result in high prediction accuracy with R2 score of 0.92 for roughness,0.86 for profile,and 0.95 for roundness.

关键词： Computer numerical control(CNC)machining Quality prediction Roughness parameter Profile deviation Roundness deviation Machine learning

Diurnal Variation of Tropical Convection during TOGA COARE IOP

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Advances in Atmospheric Sciences 2005年第5期22卷 685-702页

作者： Jae-Young BYON Gyu-ho lim School of Earth and Environmental Sciences Seoul National University Seoul South KoreaSchool of Earth and Environmental Sciences Seoul National University Seoul South Korea

Diurnal variation of tropical convection and kinematic and thermodynamic conditions was investigated for different large-scale environments of the convectively active and inactive periods by using satellite observations and surface measurements during the Intensive Observation Period （IOP） of the Tropical Ocean Global Atmosphere/Coupled Ocean-Atmosphere Response Experiment （TOGA/COARE）. During the convectively active period, the features of nocturnal convection appear in vertical profiles of convergence, vertical velocity, heat source, and moisture sink. The specific humidity increases remarkably in the middle troposphere at dawn. On the other hand, the altitude of maximum convergence and that of the upward motion is lower during the convectively inactive period. The specific humidity peaks in the lower troposphere in the daytime and decreases in the middle troposphere. Spectral analyses of the time series of the infrared （IR） brightness temperature （TBB） and amounts of rainfall suggest multiscale temporal variation with a prominent diurnal cycle over land and oceanic regions such as the Intensive Flux Array （IFA） and the South Pacific Convergence Zone （SPCZ）. Over land, the daily maximum of deep convection associated with cloud top temperature less than 208 K appears at midnight due to the daytime radiative heating and the sea-land breeze. Over the ocean, convection usually tends to occur at dawn for the convectively active period while in the afternoon during the inactive period. Comparing the diurnal variation of convection with large-scale variables, the authors inferred that moisture in the middle troposphere contributes mostly to the development of nocturnal convection over the ocean during the convectively active period.

关键词： diurnal variation tropical convection rainfall large-scale environment

Automatic Discontinuity Classification of Wind-turbine Blades Using A-scan-based Convolutional Neural Network

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Journal of Modern Power Systems and Clean Energy 2021年第1期9卷 210-218页

作者： Jiyeon Choung Sun lim Seung Hwan lim Su Chung Chi Mun ho Nam Korea Electronics Technology Institute 401-402Bucheon Technopark655Pyeongcheon-roWonmi-guBucheon-siGyeonggi-do 14502Korea Sam Yong Inspection Engineering Co.Ltd.

Recent development trends in wind power generation have increased the importance of the safe operation of wind-turbine blades(WTBs). To realize this objective, it is essential to inspect WTBs for any defects before they are placed into operation. however, conventional methods of fault inspection in WTBs can be rather difficult to implement, since complex curvatures that characterize the WTB structures must ensure accurate and reliable inspection. Moreover, it is considered useful if inspection results can be objectively and consistently classified and analyzed by an automated system and not by the subjective judgment of an inspector. To address this concern,the construction of a pressure-and shape-adaptive phased-array ultrasonic testing platform, which is controlled by a nanoengine operation system to inspect WTBs for internal defects, has been presented in this paper. An automatic classifier has been designed to detect discontinuities in WTBs by using an A-scanimaging-based convolutional neural network(CNN). The proposed CNN classifier design demonstrates a classification accuracy of nearly 99%. Results of the study demonstrate that the proposed CNN classifier is capable of automatically classifying the discontinuities of WTB with high accuracy, all of which could be considered as defect candidates.

关键词： Wind-turbine blade(WTB) blade inspection platform convolutional neural network(CNN) discontinuity phased-array ultrasonic testing(PAUT) A-scan

Gastroesophageal reflux disease at the turn of millennium

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World Journal of Gastroenterology 2003年第10期9卷 2135-2136页

作者： Lee-Guan lim Khek-Yu ho Department of Medicine National University HospitalSingapore

Gastroesophageal reflux disease (GERD) has been an area of active research in the Asia-Pacific region in the recent years. This article outlines some of the interesting research findings. It comprises three parts. The first part dealt with recent data on the changing epidemiology of GERD in *** second part summarized published studies on the relationship between GERD and Helicobacter pylori, relevant to the Asia-Pacific region. The last part discussed some of the recent advances in the treatment of GERD.

关键词： Gastroesophageal Reflux Helicobacter Infections Humans

Optimization of post-warranty sequential inspection for second-hand products

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Journal of Systems Engineering and Electronics 2017年第4期28卷 793-800页

作者： Dae-Kyung Kim Jae-Hak lim Dong ho Park Department of Statistics Chonbuk National University Department of Management & Accounting Hanbat National University Industry Academic Cooperation Foundation Hallym University

This paper considers an optimal sequential inspection schedule for a second-hand product after that the free nonrenewable warranty is expired. The length of warranty is prespecified and during the warranty period, the product is minimally repaired by the dealer when it fails. Following the expiration of the non-renewing warranty, the product is inspected and upgraded sequentially a fixed number of times at the expenses of the *** each inspection, the failure rate of the product is reduced proportionally so that the product is upgraded. The product is assumed to deteriorate as it ages and the replacement of the product occurs when a fixed number of inspections are rendered. In addition,the intervals between two successive inspections are assumed to decrease monotonically. The main objective of this paper is to determine the optimal improvement level to upgrade the product at each inspection so that the expected maintenance cost during the life cycle of the product is minimized from the perspective of the customer. Under the given cost structures, we derive an explicit formula to obtain the expected maintenance cost incurred during the life cycle of the product and discuss the method to find the optimal level of the improvement analytically in case the failure times follow the Weibull distribution. Numerical results are analyzed to observe the impact of relevant parameters on the optimal solution.

关键词： second-hand product sequential inspection upgrade action life cycle of the product expected maintenance cost free non-renewable warranty

Inhibitory effects of Cnidium monnieri fruit extract on pulmonary inflammation in mice induced by cigarette smoke condensate and lipopolysaccharide

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Chinese Journal of Natural Medicines 2014年第9期12卷 641-647页

作者： ho-Geun Kwak Heung-Bin lim Department of Industrial Plant Science & Technology Chungbuk National University Cheongju 361-763 Republic of Korea

The aim of this study was to investigate the inhibitory effect of Cnidium monnieri fruit(CM) extracts on pulmonary inflammation induced in mice by cigarette smoke condensate(CSC) and lipopolysaccharide(LPS). Pulmonary inflammation was induced by intratracheal instillation of LPS and CSC five times within 12 days. CM extract was administered orally at a dose of 50 or 200 mg·kg-1. The number of inflammatory cells in the bronchoalveolar lavage fluid was counted using a fluorescence activated cell sorter. Inflammatory mediator levels were determined by enzyme-linked immunosorbent assay. The administration of LPS and CSC exacerbated airway hyper-responsiveness(AHR) and induced an accumulation of inflammatory cells and mediators, and led to histological changes. however, these responses are modulated by treatment with CM, and the treatment with CM extract produces similar or more extensive results than the treatment with cyclosporin A(CSA). CM extract may have an inhibitory effect on pulmonary inflammation related with chronic obstructive pulmonary disease.

关键词： Pulmonary inflammation Chronic obstructive pulmonary disease Cigarette smoke condensate Cnidium monnieri fruits Lipopolysaccharide

Validation of four Helicobacter pylori rapid blood tests in a multi-ethnic Asian population

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World Journal of Gastroenterology 2005年第42期11卷 6681-6683页

作者： Lee-Guan lim Khay-Guan Yeoh Bow ho Seng-Gee lim Department of Gastroenterology and Hepatology National University hospital 5 Lower Kent Ridge Road Singapore 119074 Republic of Singapore Department of Microbiology National University of Singapore Lower Kent Ridge Road Singapore 119260 Republic of Singapore

AIM: To validate the accuracy of four rapid blood tests in the diagnosis of Helicobacter ***: Consecutive dyspeptic patients scheduled for endoscopy at the National University hospital,Singapore, were interviewed and had blood drawn for serology. The first 109 patients were tested with BM-test (BM), Pyloriset Screen (PS) and QuickVue (QV), and the next 99 subjects were tested with PS and Unigold (UG).Endoscopies were performed blinded to rapid blood test results and biopsies were taken for culture and rapid urease test. Urea breath tests were performed after endoscopies. The rapid blood test results were compared with four reference tests (rapid urease test, culture,serology, and breath test).RESULTS: The study population composed of 208patients (mean age 43.1 years; range 18-73 years; 119males; 174 Chinese). The number of evaluable patientsfor BM, QV, UG and PS were 102, 102, 95, and 197,respectively. The sensitivity and specificity, respectively were: PS 80.2%, 95.8%; UG 55.9%, 100%; QV 43.3%,100%; BM 67.2%, 97.1%.CONCLUSION: The rapid blood test kits showed high specificity and positive predictive value (97-100%), while sensitivity and negative predictive value ranged widely (43%-80% and 47%-73%, respectively). Among test kits, PS showed the best sensitivity (80%), best negative predictive value (73%) and best negative likelihood ratio (0.207). PS had a specificity of 96%, positive predictive value of 97% and positive likelihood ratio of 19.1.

关键词： Helicobacter pylori Rapid blood test