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An average-value-at-risk criterion for Markov decision processes with unbounded costs

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Frontiers of Mathematics in China 2022年第4期17卷 673-687页

作者： Qiuli LIU Wai-ki CHING Junyu ZHANG Hongchu WANG School of Mathematical Sciences South China Normal UniversityGuangzhou510631China Advanced Modeling and Applied Computing Laboratory Department of MathematicsThe University of Hong KongHong KongChina School of Mathematics Sun Yat-Sen UniversityGuangzhou510275China

We study the Markov decision processes under the average-value-at-risk *** state space and the action space are Borel spaces,the costs are admitted to be unbounded from above,and the discount factors are state-action *** suitable conditions,we establish the existence of optimal deterministic stationary ***,we apply our main results to a cash-balance model.

关键词： Markov decision processes average-value-at-risk(AVaR) state-action dependent discount factors optimal policy

Mechanical and electrochemical characteristics evaluation in annealing treatment for ship material

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中国有色金属学会会刊：英文版 2009年第B9期19卷 40-44页

作者： Seok-ki JANG Young-Jae JEONG Seong-Jong kiM Division of Marine Engineering Mokpo Maritime University Jeonnam Techno Park

The effect of heat treatment on the electrochemical and mechanical properties of SS400 steel was investigated, and the effects of annealing conditions on notched specimens subjected to the slow strain rate test (SSRT) were studied. The results show that no correlations are observed among the maximum tensile strength, yield strength, and stress corrosion cracking. In contrast, the elongation and time-to-fracture are improved with stress-relieving annealing compared with the as-received condition. The elongation, time-to-fracture, and number of dimples increase with annealing heat treatment.

关键词：退火处理电化学船舶材料特性评价机械 SS400钢应力腐蚀开裂消除应力退火

Levels of evidence and grades of recommendation supporting European society for medical oncology clinical practice guidelines

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Oncology Research 2024年第5期32卷 807-815页

作者： MARKO SKELIN BRUNA PERKOV-STIPIČIN SANJA VUŠKOVIĆ MARINAŠANDRK PLEHAČEK ANE BAŠIĆ DAVIDŠARČEVIĆ MAJA ILIĆ IVAN kreČAK Pharmacy Department General Hospital ofŠibenik-Knin CountyŠibenikCroatia Faculty of Medicine University of RijekaRijekaCroatia Undergraduate Study in Nursing University of Applied SciencesŠibenikCroatia Department of Oncology University Hospital Center ZagrebZagrebCroatia Pharmacies Joukhadar Sveta NedeljaCroatia Pharmacies Prima Pharme ZagrebCroatia Pharmacy Department General Hospital ZadarZadarCroatia Pharmacy Department General Hospital PulaPulaCroatia Department of Internal Medicine General Hospital ofŠibenik-Knin CountyŠibenikCroatia

Background:The European Society for Medical Oncology(ESMO)guidelines are among the most comprehensive and widely used clinical practice guidelines(CPGs)***,the level of scientific evidence supporting ESMO CPG recommendations has not been systematically *** study assessed ESMO CPG levels of evidence(LOE)and grades of recommendations(GOR),as well as their trends over time across various cancer ***:We manually extracted every recommendation with the Infectious Diseases Society of America(IDSA)classification from each *** examined the distribution of LOE and GOR in all available ESMO CPG guidelines across different topics and cancer ***:Among the 1,823 recommendations in the current CPG,30%were classified as LOEⅠ,and 43%were classified as GOR ***,there was a slight decrease in LOEⅠ(−2%)and an increase in the proportion of GOR A(+1%)in the current CPG compared to previous *** proportion of GOR A recommendations based on higher levels of evidence such as randomized trials(LOEⅠ–Ⅱ)shows a decrease(71%vs.63%,p=0.009)while recommendations based on lower levels of evidence(LOEⅢ–Ⅴ)show an increase(29%vs.37%,p=0.01)between previous and current *** the current versions,the highest proportion of LOEⅠ(42%)was found in recommendations related to pharmacotherapy,while the highest proportion of GOR A recommendations was found in the areas of pathology(50%)and diagnostic(50%)*** variability in LOEⅠand GOR A recommendations and their changes over time was observed across different cancer ***:One-third of the current ESMO CPG recommendations are supported by the highest level of *** well-designed randomized clinical trials are needed to increase the proportion of LOEⅠand GOR A recommendations,ultimately leading to improved outcomes for cancer patients.

关键词： ESMO guidelines Clinical practice guidelines Level of evidence Grade of recommendation

One-Pot Process to Carborano-Coumarin via Catalytic Cascade Dehydrogenative Cross-Coupling

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Chinese Journal of Chemistry 2020年第4期38卷 383-388页

作者： Yik ki Au Hairong Lyu Yangjian Quan Zuowei Xie Deportment of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong KongShatinN.T.Hong KongChina

Summary of main observation and conclusion Ir-catalyzed cascade dehydrogenative CH/BH and BH/OH cross-coupling of carboranyl carboxylic acid with readily available benzolc acid has been achieved,leading to the facile synthesis of previously unavailable carborano-coumarin in a simple one-pot *** cage B-H,one aryl C--H and one 0-H bonds are activated to construct eficiently new B-C and B-0 *** cascade cyclization can stop at the first B-H/C-H cross-coupling step by tuning the reaction conditions,resulting in a series of a-carboranyl benzoic acid and aryl carborane *** experiments indicate that B-H/C-H dehydrocoupling proceeds preferentially over B-H/O-H dehydrocoupling,and both directing groups and oxidants are crucial for this *** iridium(V)intermediate is proposed to be involved in the catalytic cycle.

关键词： reaction. process. coupling

Effects of 3D deformation and nonlinear stress–strain relationship on the Brazilian test for a transversely isotropic rock

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第12期15卷 3221-3229页

作者： Juhyi Yim Yoonsung Lee Seungki Hong ki-Bok Min R&D Center Hyundai Engineering and Construction75Yulgok-roJongno-guSeoulRepublic of Korea Department of Energy Systems Engineering and Research Institute of Energy and Resources Seoul National University1Gwanak-roGwanak-guSeoul08826Republic of Korea

To improve the accuracy of indirect tensile strength for a transversely isotropic rock in the Brazilian test, this study considered the three-dimensional (3D) deformation and the nonlinear stress–strain relationship. A parametric study of a numerical Brazilian test was performed for a general range of elastic constants, revealing that the 3D modeling evaluated the indirect tensile strength up to 40% higher than the plane stress modeling. For the actual Asan gneiss, the 3D model evaluated the indirect tensile strength up to 10% higher and slightly enhanced the accuracy of deformation estimation compared with the plane stress model. The nonlinearity in stress–strain curve of Asan gneiss under uniaxial compression was then considered, such that the evaluated indirect tensile strength was affected by up to 10% and its anisotropy agreed well with the physical intuition. The estimation of deformation was significantly enhanced. The further validation on the nonlinear model is expected as future research.

关键词： Anisotropy Transversely isotropy Brazilian test Indirect tensile strength Nonlinearity 3D modeling

Modification strategies improving the electrochemical and structural stability of high-Ni cathode materials

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Journal of Energy Chemistry 2024年第9期96卷 185-205页

作者： Yoon Bo Sim Hami Lee Junyoung Mun ki Jae kim Department of Energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

With the increasing spotlight in electric vehicles,there is a growing demand for high-energy-density batteries to enhance driving ***,several studies have been conducted on high-energy-density LiNi_(x)Co_(y)Mn_(z)O_(2)***,there is a limit to permanent performance deterioration because of side reactions caused by moisture in the atmosphere and continuous microcracks during cycling as the Ni content to express high energy increases and the content of Mn and Co that maintain structural and electrochemical stabilization *** direct modification of the surface and bulk regions aims to enhance the capacity and long-term performance of high-Ni cathode ***,an efficient modification requires a study based on a thorough understanding of the degradation mechanisms in the surface and bulk *** this review,a comprehensive analysis of various modifications,including doping,coating,concentration gradient,and single crystals,is conducted to solve degradation issues along with an analysis of the overall degradation mechanism occurring in high-Ni cathode *** also summarizes recent research developments related to the following modifications,aims to provide notable points and directions for post-studies,and provides valuable references for the commercialization of stable high-energy-density cathode materials.

关键词： High energy density High-Ni cathode materials Degradation Structural stability Lithium-ion battery

Surface characteristics of chemical conversion coating for Mg-Al alloy

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中国有色金属学会会刊：英文版 2009年第4期19卷 892-897页

作者： Masazumi OkiDO Ryoichi ICHINO Seong-Jong kiM Seok-ki JANG Nagoya University Division of Marine Engineering Mokpo Maritime University

The chemical conversion coating was formed on Mg alloy for low cost and harmlessness in environment by using the colloidal silica as the main *** film formed at 298 K was thick,which was thought to be the combination of Si and *** salt spray test,the ratio of black rust on the specimen that did not conducted chemical conversion treatment was five times or more than those of the chemical conversion treated *** film of chemical conversion coating produced by alkali treatment process was thinner than the specimen produced in basic chemical conversion treatment solution.

关键词：化学转化膜镁铝合金表面特性环境无害化盐雾试验涂膜厚度低成本硅溶胶

Integration of omics studies indicates that species-dependent molecular mechanisms govern male fertility

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Journal of Animal Science and Biotechnology 2023年第3期14卷 1026-1039页

作者： Yoo-Jin Park Won-ki Pang Myung-Geol Pang Department of Animal Science&Technology and BET Research Institute Chung-Ang UniversityAnseongGyeonggi‑do17546Republic of Korea

Background Comparative and comprehensive omics studies have recently been conducted to provide a comprehensive understanding of the biological mechanisms underlying ***,because these huge omics datasets often contain irrelevant information,editing strategies for summarizing and filtering the data are necessary prerequisite steps for identifying biomarkers of male ***,we attempted to integrate omics data from spermatozoa with normal and below-normal fertility from boars and bulls,including transcriptomic,proteomic,and metabolomic *** enrichment analysis was conducted and visualized using g:Profiler,Cytoscape,EnrichmentMap,and AutoAnnotation to determine fertility-related biological functions according to *** In particular,gamete production and protein biogenesis-associated pathways were enriched in bull spermatozoa with below-normal fertility,whereas mitochondrial-associated metabolic pathways were enriched in boar spermatozoa with normal *** results indicate that below-normal fertility may be determined by aberrant regulation of protein synthesis during spermatogenesis,and the modulation of reactive oxygen species generation to maintain capacitation and the acrosome reaction governs boar sperm *** Overall,this approach demonstrated that distinct molecular pathways drive sperm fertility in mammals in a species-dependent ***,we anticipate that searching for species-specific signaling pathways may aid in the discovery of fertility-related biomarkers within large omics datasets.

关键词： Integrated signaling pathways Male fertility Metabolomics Proteomics Spermatozoa transcriptomics

Heat Storage/Heat Release of Phase-Change Filling Body with Casing Heat Exchanger for Extracting Geothermal Energy

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Journal of Thermal Science 2023年第3期32卷 1171-1189页

作者： ZHANG Xiaoyan XU Muyan LIU Lang YANG Qixing ki-IL Song Energy School Xi'an University of Science and TechnologyXi'an 710054China Key Laboratory of Western Mines and Hazards Prevention Ministry of Education of ChinaXi'an 710054China Department of Civil Engineering Inha UniversityIncheon 402-751South Korea

Arranging heat exchanger in filling body to extract geothermal energy is an effective way to alleviate the problems of high ground pressure and high ground temperature in deep resource *** body with casing heat exchanger was acted as research object,encapsulating phase change materials(PCMs)in annular *** heat storage and heat release process,the effects of different PCMs on temperature distribution,phase-change process and heat transfer performance were *** result indicates:During heat storage process,the temperature increases rapidly and the melting process is accelerated for the position closer surrounding ***_(2)·6H_(2)O/EG can make filling body complete heat storage process in the shortest time because of its good thermal *** heat storage capacity of PCMs backfill is significantly higher than that of ordinary backfill;it increases by 36.6%-67.3%at heat storage of 10 *** heat release process,the closer to the heat exchange tube,the greater the temperature drop in filling *** maximum value of heat release rate and heat release capacity is in CaCl_(2)·6H_(2)O/EG backfill,it can release 116.4%more heat than RT35backfill after heat release of 12 h,the maximum value of effectiveness and its heat transfer rate also is in CaCl_(2)·6H_(2)O/EG *** paper provides the basic data for the selection of PCMs in phase-change thermal storage filling body.

关键词： flling body heat exchanger phase change material heat storage/heat release