检索结果-南通市图书馆

Time-periodic solutions of the Einstein's field equations Ⅲ:physical singularities

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2011年第1期54卷 23-33页

作者： kong dexing liu kefeng shen ming department of mathematics Zhejiang University Hangzhou 310027 China department of mathematics University of California at Los Angeles CA 90095 USA Center of Mathematical Sciences Zhejiang University Hangzhou 310027 China

In this paper we construct a new time-periodic solution of the vacuum Einstein's field equations, this solution possesses physical singularities, i.e., the norm of the solution's Riemann curvature tensor takes the infinity at some points. We show that this solution is intrinsically time-periodic and describes a time-periodic universe with the "time-periodic physical singularity". By calculating the Weyl scalars of this solution, we investigate new physical phenomena and analyze new singularities for this universal model.

关键词： Einstein's field equations time-periodic solution geometric singularity physical singularity Weyl scalar

Association of Pringle maneuver with postoperative recurrence and survival following hepatectomy for hepatocellular carcinoma: a multicenter propensity score and competing-risks regression analysis

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary Surgery and Nutrition 2024年第3期13卷 412-424,I0003-I0010页

作者： Shi-Chuan Tang Yong-Kang Diao kong-Ying Lin Chao Li Xiao Xu Lei Liang Jie kong Qing-Jing Chen Xian-ming Wang Fu-Bao liu Wei-Min Gu Ya-Hao Zhou Ying-Jian Liang Hong-Zhi liu ming-Da Wang Lan-Qing Yao Timothy M.Pawlik Feng shen Wan Yee Lau Tian Yang Yong-Yi Zeng department of Hepatobiliary Surgery Mengchao Hepatobiliary Hospital of Fujian Medical UniversityFuzhouChina department of Hepatobiliary Surgery Eastern Hepatobiliary Surgery HospitalNavy Medical University(Second Military Medical University)ShanghaiChina department of Hepatobiliary Surgery Affiliated Hospital of Nantong UniversityNantongChina department of Hepatobiliary Surgery People’s Hospital of Zhejiang ProvincialPeople’s Hospital of Hangzhou Medical CollegeHangzhouChina department of Hepatobiliary Heze Municiple HospitalHezeChina department of General Surgery First Affiliated Hospital of Shandong First Medical University&Shandong Provincial Qianfoshan HospitalJinanChina department of Hepatobiliary Surgery First Affiliated Hospital of Anhui Medical UniversityHefeiChina The First department of General Surgery Fourth Hospital of HarbinHarbinChina department of Hepatobiliary Surgery Pu’er People’s HospitalPu’erChina department of Hepatobiliary Surgery First Affiliated Hospital of Harbin Medical UniversityHarbinChina department of Surgery Ohio State UniversityWexner Medical CenterColumbusOHUSA Faculty of Medicine The Chinese University of Hong KongHong KongChina department of Hepatopancreatobiliary Surgery First Affiliated Hospital of Fujian Medical UniversityFuzhouChina The Liver Disease Research Center of Fujian Province FuzhouChina

Background:The application of Pringle maneuver(PM)during hepatectomy reduces intraoperative blood loss and the need for perioperative transfusion,but its effect on long-term recurrence and survival for patients with hepatocellular carcinoma(HCC)remains *** sought to determine the association between the application of PM and post-hepatectomy oncologic outcomes for patients with ***:Patients who underwent curative hepatectomy for HCC at 9 Chinese hospitals from January 2010 to December 2018 were *** two propensity score methods[propensity score matching(PSM)and inverse probability of treatment weight(IPTW)],cumulative recurrence rate and cancer-specific mortality(CSM)were compared between the patients in the PM and non-PM *** competing-risks regression models were performed to adjust for the effect of non-cancer-specific mortality and other prognostic risk ***:Of the 2,798 included patients,2,404 and 394 did and did not adopt PM(the PM and non-PM groups),*** rates of intraoperative blood transfusion,postoperative 30-day mortality and morbidity were comparable between the two groups(all P>0.05).In the PSM cohort by the 1:3 ratio,compared to 382 patients in the non-PM group,1,146 patients in the PM group also had the higher cumulative 5-year recurrence rate and CSM(63.9%and 39.1%vs.55.3%and 31.6%,both P2 and 0.77 in the adjusted entire cohort,HR 0.80 and 0.73 in the PSM cohort,and HR 0.80 and 0.76 in the IPTW cohort,respectively].Conclusions:The findings suggested that no application of PM during hepatectomy for patients with HCC reduced the risk of postoperative recurrence and cancer-specific death by appr

关键词： Hepatocellular carcinoma(HCC) Pringle maneuver(PM) recurrence survival hepatectomy

Frontiers in high entropy alloys and high entropy functional materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第10期43卷 4639-4776页

作者： Wen-Tao Zhang Wen Huang Fu-Jie Yu Qi Zhao Xin-Dong Zhu Tao Feng Yao Jiang Xiao-ming Li Xue-Fei Miao He Zhu Si Lan Xue-Qian Wang Bao-Long shen Zhe Jia Feng-Qi Zhang Wei Wang Qi liu Yang Ren Xun-Li Wang Xiao-Ya Cui Xiao-Yang Wang Ya-Nan Chen Bing-Bing Fan Meng-Ru Li Qi-Long Gao Jia-ming Guo Zeng-Bao Jiao Zhi-Min Guo Yu-Ping Zhao Qian Yu Rui Huang Ling-Kun Zhang Yi-Ping Lu Xu-Bo Li Huai-Jun Lin Yan Ma Wei-ming Yang Zhi-Hua shen Hai-Yan He Yong-Gang Sun Yong-Jiang Huang De-Zhuang Wang Qing-Feng liu Fei-Yang Wang Hui liu Hong-Hui Wu Li-Qiang Wang Yang Lu Nan Wang Tian-Li Wang Wei-Bing Liao Yi-Han Wang Yuan Wu Yu-Zhen Yin Jie Pan Yi Zhang Qing Wang Jian-Yang Zhang Tao Yang Yasir Sohail Jin-Yu Zhang Hua Ji Qiang Li Wei-Di liu Zhi-Gang Chen Xiong-Jun liu Wen Ma Liang Mao Zhen-Duo Wu School of Materials Science and Engineering Nanjing University of Science and Technology Jiangsu Key Laboratory for Advanced Metallic Materials School of Materials Science and Engineering Southeast University department of Physics City University of Hong Kong School of Materials Science and Engineering Tianjin University School of Physics and Microelectronics Zhengzhou University department of Mechanical Engineering Research Institute for Advanced Manufacturing The Hong Kong Polytechnic University Center of Electron Microscopy and State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province) School of Materials Science and Engineering Dalian University of Technology Institute of Advanced Wear & Corrosion Resistance and Functional Materials Jinan University School of Mechanics and Civil Engineering China University of Mining and Technology School of Physical Sciences Great Bay University School of Materials Science andEngineering Harbin Institute of Technology State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University Beijing Advanced Innovation Center for Materials Genome Engineering Research Institute for Carbon Neutrality University of Science and Technology Beijing department of Mechanical Engineering The University of Hong Kong School of Computing Macquarie University Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering Shenzhen University State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing State Key Laboratory of Materials Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Institute of materials Shanghai University department of Materials Science and Engineering C

Owing to their exceptional properties, high-entropy alloys(HEAs) and high-entropy materials have emerged as promising research areas and shown diverse applications. Here,the recent advances in the field are comprehensively reviewed,organized into five sections. The first section introduces the background of HEAs, covering their definition, significance,application prospects, basic properties, design principles, and microstructure. The subsequent section focuses on cutting-edge high-entropy structural materials, highlighting developments such as nanostructured alloys, grain boundary engineering,eutectic systems, cryogenic alloys, thin films, micro-nano-lattice structures, additive manufacturing, high entropy metallic glasses, nano-precipitate strengthened alloys, composition modulation, alloy fibers, and refractory systems. In the following section, the emphasis shifts to functional materials, exploring HEAs as catalysts, magneto-caloric materials, corrosion-resistant alloys, radiation-resistant alloys, hydrogen storage systems, and materials for biomedicine. Additionally, the review encompasses functional high-entropy materials outside the realm of alloys, including thermoelectric, quantum dots, nanooxide catalysts, energy storage materials, negative thermal expansion ceramics,and high-entropy wave absorption materials. The paper concludes with an outlook, discussing future directions and potential growth areas in the field. Through this comprehensive review,researchers, engineers, and scientists may gain valuable insights into the recent progress and opportunities for further exploration in the exciting domains of high-entropy alloys and functional materials.

关键词： Cutting-edge structural materials Cutting-edgefunctional materials High entropy alloys

Diagnosis,treatment and prevention of severe acute respiratory syndrome coronavirus 2 infection in children:experts'consensus statement updatedforthe Omicron variant

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第3期20卷 272-286页

作者： Rong-Meng Jiang Zheng-De Xie Yi Jiang Xiao-Xia Lu Run-ming Jin Yue-Jie Zheng Yun-Xiao Shang Bao-Ping Xu Zhi-sheng liu Gen Lu Ji-Kui Deng Guang-Hua liu Xiao-Chuan Wang Jian-She Wang Lu-Zhao Feng Wei liu Yi Zheng Sai-Nan Shu Min Lu Wan-Jun Luo Miao liu Yu-Xia Cui Le-Ping Ye A-Dong shen Gang liu Li-Wei Gao Li-Juan Xiong Yan Bai Li-Kai Lin Zhuang Wei Feng-Xia Xue Tian-You Wang Dong-Chi Zhao Jian-Bo Shao Daniel Kwok-keung Ng Gary Wing-kin Wong Zheng-Yan Zhao Xing-Wang Li Yong-Hong Yang Kun-Ling shen Diagnosis and Treatment Center of Infectious Diseases Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Beijing Key Laboratory of Pediatric Respiratory Infection Diseases Key Laboratory of Major Diseases in ChildrenMinistry of EducationNational Clinical Research Center for Respiratory DiseasesResearch Unit of Critical Infection in ChildrenChinese Academy of Medical Sciences2019RU016Laboratory of Infection and VirologyBeijing Pediatric Research InstituteBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijing 100045China department of Pediatrics Renmin Hospital of Wuhan UniversityWuhan 430060China department of Respiratory Wuhan Children's HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430016China department of Pediatrics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China department of Respiratory Shenzhen Children's HospitalShenzhen 518038China department of Pediatric Respiratory Shengjing Hospital Affiliated to China Medical UniversityShenyang 110004China department of Respiratory Beijing Children's HospitalCapital Medical UniversityNational Clinical Research Center for Respiratory DiseasesNational Center for Children's HealthBeijing 100045China department of Neurology Wuhan Children's HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430016China department of Respiratory Guangzhou Women and Children's Medical CenterGuangzhou 510623China department of Infectious Diseases Shenzhen Children's HospitalShenzhen 518038China department of Pediatrics Fujian Branch of Shanghai Children's Medical CenterFujian Children's HospitalFuzhou350005China department of Clinical Immunology and Allergy Children's Hospital of Fudan UniversityNational Center for Children's HealthShanghai 201102China department of Infectious Diseases Children's Hospital of Fudan UniversityNational Center for Children's Health.Shanghai

It has been more than 3 years since the novel coronavirus(SARS-CoV-2)pandemic raged *** coronavirus disease 2019(COVID-19)has greatly influenced human *** to data from the World Health Organization(WHO),there were ove... 详细信息

关键词： prevention infection statement

基于PSD的分离式长导轨直线度测量方法研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

计量学报 2024年第3期45卷 425-432页

作者：金挺朱进陈挺郭斌沈斌孔明程银宝王瑛辉浙江省计量科学研究院浙江杭州310018 浙江省数字精密测量技术研究重点实验室浙江杭州310018 杭州光尺科技有限公司浙江杭州310018 中国计量大学浙江杭州310018

利用分段拼接测量方法能够将PSD激光准直测量系统测量范围扩大,相较于传统长导轨直线度测量方法,该方法可同时适用于连续型导轨和分离式超长导轨的直线度测量。首先,在(-5~+5) mm测量范围内,通过激光干涉仪分别测得激光准直测量系统的... 详细信息

利用分段拼接测量方法能够将PSD激光准直测量系统测量范围扩大,相较于传统长导轨直线度测量方法,该方法可同时适用于连续型导轨和分离式超长导轨的直线度测量。首先,在(-5~+5) mm测量范围内,通过激光干涉仪分别测得激光准直测量系统的接收靶在水平和竖直方向上的位移,误差均优于±(1μm+1%H)。然后,在40 m范围内与激光准直测量系统的直线度测量精度进行对比,二者水平方向直线度误差相差0.06 mm,竖直方向直线度误差相差0.13 mm。最后,在70 m分离式超长导轨上,测得水平方向直线度为0.50 mm,竖直方向直线度为0.53 mm。该方法可迅速定位和调整直线度误差极值点位置,能够较为有效地解决分离式超长导轨的直线度装配调试问题。

关键词：几何量计量超长导轨直线度拼接方法最小二乘

Grading severity of microscopic vascular invasion was independently associated with recurrence and survival following hepatectomy for solitary hepatocellular carcinoma

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary Surgery and Nutrition 2024年第1期13卷 16-28页

作者： Lan-Qing Yao Chao Li Yong-Kang Diao Lei Liang Hang-Dong Jia Shi-Chuan Tang Yong-Yi Zeng Han Wu ming-Da Wang Li-Hui Gu Timothy MPawlik Wan Yee Lau Cheng-Wu Zhang Feng shen Kui Wang Tian Yang department of Hepatobiliary Surgery Eastern Hepatobiliary Surgery HospitalSecond Military Medical University(Navy Medical University)ShanghaiChina department of General Surgery Cancer CenterDivision of Hepatobiliary and Pancreatic SurgeryZhejiang Provincial People’s HospitalAffiliated People’s HospitalHangzhou Medical CollegeHangzhouChina department of Hepatobiliary Surgery Mengchao Hepatobiliary HospitalFujian Medical UniversityFuzhouChina department of Surgery Ohio State UniversityWexner Medical CenterColumbusOHUSA Faculty of Medicine the Chinese University of Hong KongShatinNew TerritoriesHong KongChina Eastern Hepatobiliary Clinical Research Institute Third Affiliated Hospital of Navy Medical UniversityShanghaiChina

Background:Hepatectomy is the preferred treatment for solitary hepatocellular carcinoma(HCC)without macrovascular invasion and distant metastasis,but long-term survival remains unsatisfactory in certain *** sought to identify whether the grading severity of microscopic vascular invasion(MVI)was associated with recurrence and survival among patients with solitary ***:Consecutive patients who underwent hepatectomy for solitary HCC were identified from a multicenter prospectively-collected *** were categorized into three groups according to the MVI grading system proposed by the Liver Cancer Pathology Group of china:M0(no MVI),M1(1-5 sites of MVI occurring≤1.0 cm away from the tumor),and M2(>5 sites occurring≤1.0 cm or any site occurring>1 cm away from the tumor).Recurrence-free survival(RFS)and overall survival(OS)were compared among the ***:Among 227 patients,97(42.7%),83(36.6%),and 47(20.7%)patients had M0,M1,and M2,*** RFS rates among patients with M0,M1,and M2 were 38.3,35.1,11.6 months,respectively,while OS rates were 66.8,62.3,30.6 months,respectively(both P1).Multivariate Cox-regression analyses demonstrated that both M1 and M2 were independent risk factors for RFS(hazard ratio 1.20,95%CI:1.03-1.89,P=0.040;and hazard ratio 1.67,95%CI:1.06-2.64,P=0.027)and OS(hazard ratio 1.28,95%CI:1.05-2.07,P=0.035;and hazard ratio 1.97,95%CI:1.15-3.38,P=0.013).Conclusions:Grading severity of MVI was independently associated with RFS and OS after hepatectomy for solitary *** surveillance for recurrence and potentially adjuvant therapy may be considered for patients with MVI,especially individuals with more severe MVI grading(M2).

关键词： Hepatocellular carcinoma microscopic vascular invasion recurrence survival hepatectomy

浅水环境水体底部湍流对船舶气泡减阻效果影响的实验研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

船海工程 2024年第S01期53卷 63-68,72页

作者：沈琪高启迪李铭中国船级社大连分社辽宁大连116013 浙江海洋大学浙江舟山316022 香港明华船务有限公司广东深圳518000

为了解外部湍流流场对气泡减阻效果的影响,通过平板实验的方式,对不同水深的浅水环境进行模拟实验。通过粒子测速仪(PIV)观测平板气泡流场,结合平板在水流中的受力变化,研究不同水深湍流流场对于气泡减阻效果的影响。结果表明,气泡减阻... 详细信息

为了解外部湍流流场对气泡减阻效果的影响,通过平板实验的方式,对不同水深的浅水环境进行模拟实验。通过粒子测速仪(PIV)观测平板气泡流场,结合平板在水流中的受力变化,研究不同水深湍流流场对于气泡减阻效果的影响。结果表明,气泡减阻机理之一是通过湍流抑制减阻,在非浅水环境和浅水环境下,减阻效果不同,且喷气量在浅水环境中对气泡减阻起着关键作用。

关键词：船舶气泡减阻气泡流浅水环境

Effects of vacancies on interwall spacings of multi-walled carbon nanotubes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of zhejiang university-Science A(Applied Physics & Engineering) 2010年第10期11卷 714-721页

作者： ming-du MA Jefferson Zhe liu Li-feng WANG Lu-ming shen Quan-shui ZHENG department of Engineering Mechanics Tsinghua University Beijing 100084 China department of Mechanical and Aerospace Engineering Monash University Clayton Victoria 3168 Australia department of Mechanical Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA School of Civil Engineering University of Sydney NSW 2006 Australia

We use molecular dynamics (MD) simulations to study the effects of vacancies on tube diameters and interwall spacings of multi-walled carbon nanotubes (MWCNTs). Two types of vacancies, double vacancy and three dangling-bond (3DB) single vacancy, are identified to have opposite effects on the tube size change, which explains the inconsistency of the experimentally measured interwall spacings of MWCNTs after electron beam irradiation. A theoretical model to quantitatively predict the shrunk structures of the irradiated MWCNTs is further developed. We also discuss the fabrications of prestressed MWCNTs, in which reduced interwall spacings are desired to enhance the overall elastic modulus and strength.

关键词： Multi-walled carbon nanotubes (MWCNTs) Noise carbon nanotubes Electron beam irradiation Defects

Synchronous primary duodenal papillary adenocarcinoma and gallbladder carcinoma:A case report and review of literature

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第27期10卷 9790-9797页

作者： Jing Chen ming-Yuan Zhu Yan-Hua Huang Zhong-Cheng Zhou Yi-Yu shen Quan Zhou ming-Jian Fei Fan-Chuang kong department of General Surgery The Second Affiliated Hospital of Jiaxing UniversityJiaxing 314000Zhejiang ProvinceChina department of Pathology The Second Affiliated Hospital of Jiaxing UniversityJiaxing 314000Zhejiang ProvinceChina

BACKGROUND Synchronous primary cancers(SPCs) have become increasingly frequent over the past ***,the coexistence of duodenal papillary and gallbladder cancers is rare,and such cases have not been previously reported in the English ***,we describe an SPC case with duodenal papilla and gallbladder cancers and its diagnosis and successful *** SUMMARY A 68-year-old Chinese man was admitted to our hospital with the chief complaint of dyspepsia for the past ***-enhanced computed tomography of the abdomen performed at the local hospital revealed dilatation of the bile and pancreatic ducts and a space-occupying lesion in the duodenal *** revealed a tumor protruding from the duodenal *** findings for the biopsied tissue revealed tubular villous growth with moderate heterogeneous *** treatment was *** examination of this surgical specimen revealed a 2-cm papillary tumor and another tumor protruding by 0.5 cm in the gallbladder neck *** rapid pathology identified adenocarcinoma in the gallbladder neck duct and tubular villous adenoma with high-grade intraepithelial neoplasia and local canceration in the duodenal *** an uneventful postoperative recovery,the patient was discharged without *** It is essential for clinicians and pathologists to maintain a high degree of suspicion while evaluating such synchronous cancers.

关键词： Synchronous primary cancers Gallbladder carcinoma Duodenal papillary adenocarcinoma Surgical treatment Case report