检索结果-南通市图书馆

Enhanced Natural Convection for Accelerating Melting of Phase Change Material in Cellular Structure through Inserting Fin

引用

Journal of Thermal Science 2024年第2期33卷 548-563页

作者： KONG Dekui zhang Yongcun LIU shutian State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian116024China

The design of thermal conductivity enhancers(TCE) is quite critical to overcoming the disadvantage of the poor thermal conductivity of phase change materials(PCM).The main contribution of this study is firstly to discuss how to actively enhance natural convection of the melted PCM in cellular structure by the fin formed in the structure under the condition of the same metal mass,apart from simultaneously improving heat conduction,which can boost the heat transfer ***,a tailored hybrid fin-lattice structure(HFS) as TCE is designed and fabricated by additive manufacturing(AM).A two-equation numerical method is applied to study the heat transfer of the PCM,and its feasibility is validated with the experimental *** numerical results indicate that enhanced natural convection and improved heat conduction can be obtained simultaneously when a well-designed fin is embedded into a lattice *** enhanced natural convection results in the improved melting rate and the decreased wall temperature;e.g.,the complete melting time and the wall temperature are reduced by 11.6% and 19.7%,respectively,because of the fin for metal ***,the parameters of HFS including the porosity,pore density,and fin dimension have a great impact on the heat *** enhancement effect of the fin for HFS on the melting rate of the PCM increases as the thermal conductivity of the base material *** example,when the fin is introduced into the lattice structure,the complete melting time is reduced by 24.1% for metal *** summary,this study enables us to obtain a good understanding of the mechanism of the heat transfer and provides necessary experimental data for the structural design of HFS fabricated by AM.

关键词： natural convection heat transfer enhancement phase change material additive manufacturing hybrid fin-lattice structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Topology Optimization Method for Microscale Structures Described with Integral Nonlocal Theory

引用

Acta Mechanica Solida Sinica 2024年第1期37卷 63-71页

作者： Jiayu Li Quhao Li shutian Liu State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China

The integration of additive manufacturing and topology optimization makes it possible to fabricate complex configurations,especially for microscale structures,which can guarantee the realization of high-performance structural ***,topology results often contain microstructures(several multicellular scales)similar to the characteristic length of local macrostructures,leading to errors in structural performance analysis based on classical ***,it is necessary to consider the size effect in topology *** this paper,we establish a novel topology optimization model utilizing the integral nonlocal theory to account for the size *** approach consists of an integral constitutive model that incorporates a kernel function,enabling the description of stress at a specific point in relation to strain in a distant *** optimization structures based on nonlocal theory are presented for some benchmark examples,and the results are compared with those based on classical medium *** material layout exhibits significant differences between the two approaches,highlighting the necessity of topology optimization based on nonlocal theory and the effectiveness of the proposed method.

关键词： Topology optimization Microstructures Integral nonlocal theory Size effect

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modifiable risk factors for esophageal cancer in endoscopic screening population:A modeling study

引用

Chinese Medical Journal 2024年第3期137卷 350-352页

作者： Qian zhang Fan Wang Hao Feng Jie Xing Shengtao Zhu Hao zhang Yang Li Wenqiang Wei shutian zhang Department of Gastroenterology Beijing Friendship HospitalCapital Medical UniversityNational Clinical Research Center for Digestive DiseaseBeijing Digestive Disease CenterBeijing Key Laboratory for Precancerous Lesion of Digestive DiseaseBeijing 100050China Center for Applied Statistics and School of Statistics Renmin University of ChinaBeijing 100872China Statistical Consulting Center Renmin University of ChinaBeijing 100872China National Cancer Center National Clinical Research Center for CancerCancer InstituteChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China Department of Gastroenterology Jizhong Energy Fengfeng Group HospitalHandanHebei 056000China RSS and China-Re Life Joint Lab on Public Health and Risk Management Renmin University of ChinaBeijing 100872China

To the Editor:Esophageal cancer,one of the most common cancer types in China,with an estimated 346,633 new cases and 323,600 deaths in 2022,is becoming an increasingly serious clinical and public health problem.^([1])The successful promotion of the self-management strategy has indicated that lifestyle modifications can be valuable in the primary prevention of cancer *** a healthy lifestyle has become a novel strategy for primary prevention and risk reduction in high-risk *** epidemiological studies have identified several lifestyle-related risk factors for esophageal cancer,including smoking and diet.^([2])Each factor can typically explain a modest proportion of cancer ***,when combined,these known risk factors may substantially affect the risk of esophageal ***,some risk factors for esophageal cancer are non-modifiable,including age,low socioeconomic status,and family *** and how these non-modifiable risk factors affect primary cancer prevention by intervening with modifiable risk factors remain unclear.

关键词： esophageal prevention promotion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Three-level NPC Inverter with IGCT for High Power AC Drives

Three-level NPC Inverter with IGCT for High Power AC Drives

引用

第11届国际电机与系统学术会议

作者： shutian zhang~1,Qiongxuan Ge~1,Yaohua Li~1 1 Institute of Electrical Engineering Chinese Academy of Sciences,Beijing P.R.China

This paper present a high power three-level NPC inverter with the Integrated Gate-Commntated Thyristor(IGCT) *** power circuit consisted of a 12-pulse diodes rectifier and three-level NPC inverter with IGCT.A valid SVPWM control strategy filled with a TMS320F2407 DSP controller is proposed to improve power quality,reduce total harmonic distortion and overcome the problem of the minimum pulse *** to the three-level configuration and the valid SVPWM control method, the output harmonic is *** experimental of three phase system demonstrated that both the power circuit and control system designed are reasonable and valid.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Three-level NPC Inverter with IGCT for High Power AC Drives

Three-level NPC Inverter with IGCT for High Power AC Drives

引用

11th International Conference on Electrical Machines and Systems

作者： shutian zhang~1 Qiongxuan~1 Ge Yaohua Li 1 Institute of Electrical Engineering Chinese Academy of Sciences Beijing P.R.China

＜正＞Ⅰ.INTRODUCTION Recently,Three-level NPC inverters have been widely used for high power AC *** Integrated Gate-Commutated Thyristor（IGCT）is a new power *** several years of its introduction,the IGCT has established itself as power device of choice at MW levels by offering reliability and efficiency and the high power densities. This paper presents a high power Three-level NPC inverter with IGCT devices and its control for variable frequency AC drives.A new switching sequence method is proposed to overcome minimum-on-pulsewidth and eliminate even-order harmonic.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Vonoprazan 10 mg or 20 mg *** 15 mg as maintenance therapy in Asian patients with healed erosive esophagitis:A randomized controlled trial

引用

Chinese Medical Journal 2024年第8期137卷 962-971页

作者： Yinglian Xiao Jiaming Qian shutian zhang Ning Dai Hoon Jai Chun Chengtang Chiu Chui Fung Chong Nobuo Funao Yuuichi Sakurai Jessica D.Eisner Li Xie Minhu Chen Department of Gastroenterology The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong 510062China Department of Gastroenterology Peking Union Medical College HospitalPeking Union Medical CollegeChinese Academy of Medical SciencesBeijing 100006China Department of Gastroenterology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Department of Gastroenterology Sir Run Run Shaw HospitalSchool of Medicine Zhejiang UniversityHangzhouZhejiang 310020China Department of Internal Medicine Korea University Anam HospitalKorea University College of Medicine73 Goryeodae-roSeongbuk-guSeoul 02841Republic of Korea Department of Gastroenterology&Hepatology Linkou Medical CenterChang Gung Memorial HospitalTaoyuanTaiwan 33353China College of Medicine Chang Gung UniversityTaoyuanTaiwan 33353China Takeda Development Center Asia Singapore 018981Singapore Takeda Pharmaceutical Company Chuo-kuOsaka 540-8645Japan Takeda Pharmaceuticals International Company CambridgeMA02142 USA China Medical Team Takeda ChinaBeijing 100027China Hoffmann-La Roche Basel4070 Switzerland Abbott Laboratories Lake ForestIL 60045USA

Background:Erosive esophagitis(EE)is a gastroesophageal reflux disease characterized by mucosal breaks in the *** pump inhibitors are widely used as maintenance therapy for EE,but many patients still *** this trial,we evaluated the noninferiority of vonoprazan *** as maintenance therapy in patients with healed ***:We performed a double-blind,double-dummy,multicenter,phase 3 clinical trial among non-Japanese Asian adults with endoscopically confirmed healed EE from April 2015 to February *** from China,South Korea,and Malaysia were randomized to vonoprazan 10 mg or 20 mg once daily or lansoprazole 15 mg once daily for 24 *** primary endpoint was endoscopically confirmed EE recurrence rate over 24 weeks with a noninferiority margin of 10%using a two-sided 95%confidence interval(CI).Treatment-emergent adverse events(TEAEs)were ***:Among 703 patients,EE recurrence was observed in 24/181(13.3%)and 21/171(12.3%)patients receiving vonoprazan 10 mg or 20 mg,respectively,and 47/184(25.5%)patients receiving lansoprazole(differences:-12.3%[95%CI,-20.3%to-4.3%]and-13.3%[95%CI,-21.3%to-5.3%],respectively),meeting the primary endpoint of noninferiority to lansoprazole in preventing EE recurrence at 24 *** of superiority(upper bound of 95%CI12 weeks,endoscopically confirmed EE recurrence was observed in 5/18,2/20,and 7/20 of patients receiving vonoprazan 10 mg,vonoprazan 20 mg,and lansoprazole,*** were experienced by 66.8%(157/235),69.0%(156/226),and 65.3%(158/242)of patients receiving vonoprazan 10 mg,vonoprazan 20 mg,and lansoprazole,*** most common TEAE was upper respiratory tract infection in 12.8%(30/235)and 12.8%(29/226)patients in vonoprazan 10 mg and 20 mg groups,respectively and 8.7%(21/242)patients in lansoprazole ***:Vonoprazan maintenance therapy was well-tolerated and noninferior to lansoprazole for preventing EE recurrence i

关键词： Erosive esophagitis Lansoprazole Maintenance therapy Potassium-competitive acid blockers Vonoprazan

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese national clinical practice guidelines on prevention, diagnosis and treatment of early colorectal cancer

引用

中华医学杂志(英文版) 2024年第17期137卷 2024 Aug 6页

作者： Li Jingnan Yao Hongwei Lu Yun zhang shutian zhang Zhongtao Society of Digestive Endoscopy of the Chinese Medical Association Colorectal Surgery Group of the Chinese Medical Association Chinese Association of Gastroenterologist & Hepatologist National Clinical Research Center for Digestive Diseases Chinese Medical Journal Clinical Practie Guideline Collaborative Department of Gastroenterology Peking Union Medical College Hospital Chinese Academy of Medical Sciences Peking Union Medical College Beijing China Department of General Surgery Beijing Friendship Hospital Capital Medical University National Clinical Research Center for Digestive Diseases Beijing China Department of General Surgery The Affiliated Hospital of Qingdao University Qingdao Shandong China Department of Gastroenterology Beijing Friendship Hospital Capital Medical University National Clinical Research Center for Digestive Disease Beijing China

Background: The incidence and mortality of colorectal cancer (CRC) in China are increasing in recent years. The clarified pathogenesis and detectable precancerous lesions of CRC make it possible to prevent, screen, and diagnose CRC at an early stage. With the development of endoscopic and surgical techniques, the choice of treatment for early CRC is also worth further discussion, and accordingly, a standard follow-up program after treatment needs to be ***: This clinical practice guideline (CPG) was developed following the recommended process of the World Health Organization, adopting Grading of Recommendations Assessment, Development and Evaluation (GRADE) in assessing evidence quality, and using the Evidence to Decision framework to formulate clinical recommendations, thereby minimizing bias and increasing transparency of the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guides to ensure the guideline’s completeness and ***: This CPG comprises 46 recommendations concerning prevention, screening, diagnosis, treatment, and surveillance of CRC. In these recommendations, we have indicated protective and risk factors for CRC and made recommendations for chemoprevention. We proposed a suitable screening program for CRC based on the Chinese context. We also provided normative statements for the diagnosis, treatment, and surveillance of CRC based on existing clinical evidence and ***: The 46 recommendations in this CPG are formed with consideration for stakeholders’ values and preferences, feasibility, and acceptability. Recommendations are generalizable to resource-limited settings with similar CRC epidemiology pattern as China.

关键词： Colorectal cancer Early detection of cancer Prevention Screening Diagnosis Treatment Follow-up Guideline

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Non-alcoholic fatty liver degree and long-term risk of incident inflammatory bowel disease: A large-scale prospective cohort study

引用

中华医学杂志(英文版) 2024年第14期137卷 2023 Nov 13页

作者： zhang Qian Liu Si Wu Jing Zhu Shengtao Wu Yongdong Wu Shanshan zhang shutian Department of Gastroenterology Beijing Friendship Hospital Capital Medical University National Clinical Research Center for Digestive Disease Beijing Digestive Disease Center Beijing Key Laboratory for Precancerous Lesion of Digestive Disease Beijing China

Background: Non-alcoholic fatty liver disease (NAFLD) and inflammatory bowel disease (IBD) have shown similar worsening epidemic patterns globally and shared various overlapping pathophysiological mechanisms. However, evidence on the relationship between NAFLD and IBD risk is lacking. We aimed to investigate the associations between long-term risk of incident IBD and NAFLD in a large prospective ***: Participants from the United Kingdom Biobank cohort (https://***/) who were free of IBD and alcoholic liver disease at baseline were enrolled. Baseline non-alcoholic fatty liver degree was measured by the well-established fatty liver index (FLI). The outcomes of interest included incident IBD, ulcerative colitis (UC), and Crohn’s disease (CD). Multivariable Cox proportional hazard regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).Results: Among 418,721 participants (mean FLI: 48.11 ± 30.11), 160,807 (38.40%) participants were diagnosed as NAFLD at baseline. During a median of 12.4 years’ follow-up, 2346 incident IBD cases (1545 UC, 653 CD, and 148 IBD-unclassified) were identified. Due to limited events, those IBD-unclassified were combined in UC or CD when examining the associated risk of UC or CD, separately. Compared with the lowest quartile of FLI, the highest quartile showed a separately 36.00%, 25.00%, and 58.00% higher risk of incident IBD (HRQ4vs. Q1 =1.36, 95% CI: 1.19-1.55,Ptrend 1), UC (HRQ4vs. Q1 =1.25, 95% CI: 1.07-1.46,Ptrend=0.047), and CD (HRQ4vs. Q1 =1.58, 95% CI: 1.26-1.97,Ptrend 1) after multivariable adjustment. Compared with non-NAFLD, NAFLD participants had a significantly higher risk of incident IBD (HR=1.13, 95% CI: 1.04-1.24) and CD (HR =1.36, 95% CI: 1.17-1.58).Conclusions: Higher degree of non-alcoholic fatty liver is associated with increased risk of incident IBD. Interventions aimed at improving NAFLD may be a potential targeted strategy for the detection and treatm

关键词： Non-alcoholic fatty liver disease Inflammatory bowel disease Ulcerative colitis Crohn’s disease Cohort study

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于因果正则化极限学习机的风电功率短期预测方法

引用

电力系统保护与控制 2024年第11期52卷 127-136页

作者：杨茂张书天王勃现代电力系统仿真控制与绿色电能新技术教育部重点实验室(东北电力大学) 吉林吉林132012 新能源与储能运行控制国家重点实验室(中国电力科学研究院有限公司) 北京100192

随着风电并网比例的逐年提高,电力系统对风电功率预测的准确性和稳定性提出了更高要求。对于同一风电场而言,为了避免不同特征选择方法所选择的风电场特征子集不同,从因果关系的角度出发,提出了一种基于因果正则化极限学习机(causal reg... 详细信息

随着风电并网比例的逐年提高,电力系统对风电功率预测的准确性和稳定性提出了更高要求。对于同一风电场而言,为了避免不同特征选择方法所选择的风电场特征子集不同,从因果关系的角度出发,提出了一种基于因果正则化极限学习机(causal regularized extreme learning machine, CRELM)的风电功率短期预测方法。首先将极限学习机(extreme learning machine, ELM)建模为结构因果模型(structural causal model, SCM),在此基础上计算隐藏层神经元与输出层神经元之间的平均因果效应向量。然后将该平均因果效应向量与输出层权重相结合构成因果正则化项,在最小化训练误差的同时最大化网络的因果关系,以进一步提升模型的预测准确性和预测稳定性。最后,以国内蒙西某风电场数据为例,与采用特征选择或不采用特征选择的预测模型相对比,验证了所提方法的有效性和适用性。

关键词：特征选择因果正则化结构因果模型平均因果效应向量极限学习机

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

知识经济时代的价值创造:企业科技关联会创造超额回报吗?

引用

中国软科学 2024年第1期 47-58页

作者：张少华梁舒恬广州大学经济与统计学院广东广州510006 广东培正学院数字经济研究所广东广州510830

在知识经济时代,企业科技关联会创造超额回报吗?研究揭示中国资本市场是否存在科技动量效应以及该效应的来源。研究发现:中国资本市场存在显著的科技动量效应。投资科技关联因子构建的多空投资策略可以带来1.06%~1.68%的月度超额回报。... 详细信息

在知识经济时代,企业科技关联会创造超额回报吗?研究揭示中国资本市场是否存在科技动量效应以及该效应的来源。研究发现:中国资本市场存在显著的科技动量效应。投资科技关联因子构建的多空投资策略可以带来1.06%~1.68%的月度超额回报。此超额回报不是风险补偿的结果,而是由于投资者有限注意力造成的错误定价,并且这种错误定价需要1~3个月才可以得到纠正。研究结果对于理解企业研发收益、企业技术溢出、投资组合构建以及中国资本市场有效性等有着重要的参考价值。

关键词：科技关联因子市场异象投资组合分析法 Fama-MacBeth回归分析

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：