检索结果-南通市图书馆

Frontiers of Structural and Civil Engineering 2023年第2期17卷 191-204页

作者： Wenchang sun Nan JIANG Chuanbo ZHOU jinshan sun Tingyao WU Faculty of Engineering China University of GeosciencesWuhan 430074China Hubei(Wuhan)Institute of Explosion and Blasting Technology Jianghan UniversityWuhan 430056China

Blasting engineering in complex urban environments is considered to influence the safety and stability of the overlying drainage box culvert structure owing to ***,field blasting and vibration tests were performed on the blasting engineering of the Wuhan Metro Line 8 connected aisle,and the LS-DYNA software was used to analyze the dynamic response characteristics of an underground drainage box culvert during the blasting *** vibration response evolution law of the buried drainage box culvert under blasting vibration was investigated,and a safe surface control standard for the blast vibration of a drainage box culvert is *** results reveal that the maximum tensile stress of the box culvert structure was 0.33 *** peak particle velocity(PPV)and peak tensile stress(PTS)of the drainage box culvert decreased as the water level in the box culvert *** on the relationship between the tensile stress of the box culvert,PPV of the box culvert,and PPV of the surface,it is proposed that the surface control velocity of the buried drainage box culvert is 1.36 cm/s.

关键词： drainage box culvert underpass blasting dynamic response numerical simulation safety assessment

同方期刊数据库

Numerical Investigations on the Steady and Unsteady Leakage Flow and Heat Transfer Characteristics of Rotor Blade Squealer Tip

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第4期20卷 304-311页

作者： Jun LI Hao sun jinshan WANG Zhenping FENG Institute of Turbomachinery Xi＇an Jiaotong University Xi＇an 710049 CHINA

The steady and unsteady leakage flow and heat transfer characteristics of the rotor blade squealer tip were conducted by solving Reynolds-Averaged Navier-Stokes （RANS） equations with k-co turbulence model. The first stage of GE-E3 engine with squealer tip in the rotor was adopted to perform this work. The tip clearance was set to be 1% of the rotor blade height and the groove depth was specified as 2% of the span. The results showed that there were two vortexes in the tip gap which determined the local heat transfer characteristics. In the steady flow field, the high heat transfer coefficient existed at several positions. In the unsteady case, the flow field in the squealer tip was mainly influenced by the upstream wake and the interaction of the blades potential fields. These unsteady effects induced the periodic variation of the leakage flow and the vortexes, which resulted in the fluctuation of the heat transfer coefficient. The largest fluctuation of the heat transfer coefficient on the surface of the groove bottom exceeded 16% of the averaged value on the surface of the squealer tip.

关键词： Gas Turbine Blade Squealer Tip Leakage Flow Heat Transfer Numerical Simulation

The first-principle study on the equation of state of HMX under high pressure

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2011年第5期54卷 831-835页

作者： CHEN Jun LONG Yao LIU YongGang NIE FuDe sun jinshan Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P.O. Box 8009-26 Beijing 100083 China Institute of Chemical Materials CAEP Mianyang 621900 China

The equation of states （EOS） of high energy explosive HMX （octahydro-l,3,5,7-tetranitro-1,3,5,7-tetrazocine） has been studied by using the first principle method. Our results include the lattice constants, elastic constants, and the dependence of total en- ergy and pressure on volume for β- and 5-HMX. The calculated elastic constants and the pressure-volume relationship of ^-HMX are also compared with the experimental values. The theoretical tensile experiments are implemented on the 13-HMX. The atomic-scale analysis displays that the fracture originates from the intermolecule of HMX and is possibly due to the weak interaction of intermolecules.

关键词： HMX equation of states the In-st-principle method

Effect of Support Height on Microstructure and Mechanical Properties of Selective Laser Melting Ti-15Mo Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2023年第12期36卷 1947-1960页

作者： Libo Zhou Xisheng Bi jinshan sun Zhiming Hu Cong Li Jian Chen Yanjie Ren Yan Niu Wei Qiu Wei Chen Institute of Energy and Power Engineering Changsha University of Science and TechnologyChangsha410114China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

In this research,for the first time,the Ti-15Mo alloy generated via selective laser melting(SLM)with many different support heights was *** the increase of the support height,the risks of forming microcracks and small holes increase while the ductility of the sample *** grain sizes of the samples decrease with an increase in support height because of the more efficient heat dissipation rate during the SLM *** average grain sizes of the samples are 36.95±0.7μm(5 mm-sample I),35.24±0.7μm(10 mm-sample II)and 33.91±0.7μm(15 mm-sample III),*** the support height increases,the intensity of(111)texture increases and the misorientation angles gradually *** ultimate tensile strength,yield strength and ductility of the three samples are 970±13 MPa,769±12 MPa and 9.78%±1.5%(sample I),1051±11 MPa,932±11 MPa and 7.17%±2%(sample II),1123±14 MPa,1089±9 MPa and 5.4%±1.4%(sample III),*** decrease in grain size,increase in dislocation density and enhancement of the(111)texture are all conducive to achieving the higher strength.

关键词： Selective laser melting Titanium alloy Support height Microstructure

Fabry disease combined with acute interstitial nephritis:one case and literature review

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

TMR Clinical Research 2018年第2期1卷 61-67页

作者： jinshan sun Chaoying Chen Yubing Wen Children's Hospital Affiliated to Capital Institute Of Pediatrics Department of NephrologyBeijing 100020China Peking Union Medical College Hospital Chinese Academy of Medical SciencesDepartment of NephrologyBeijing 100020China

Objective:To explore the clinical and pathological features of Fabry disease complication of acute interstitial ***:A retrospective analysis of a patient with Fabry disease and acute interstitial nephritis diagnosed and in the Department of Nephrology,Children’s Hospital Affiliated to Capital Institute of Pediatrics in January 2017 was performed.A literature search was performed with“Fabry disease,acute interstitial nephritis”as the keywords in Wanfang database and PubMeds ***:The patient was 10-years-old with acute renal *** microscopy showed stratified myelin-like bodies,zebra bodies and fused foot *** patient was finally diagnosed with the combination of Fabry disease and acute interstitial *** now,such cases have been ***:Whether Fabry's disease and acute interstitial nephritis shared the common pathogenic mechanism is *** renal biopsy is important for the diagnosis of this disease.

关键词： Fabry disease Acute interstitial nephritis Renal biopsy

Advances in numerical simulation of demolition blasting

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

Engineering Sciences 2014年第6期12卷 24-31页

作者： Xie Xianqi Liu Jun Jia Yongsheng sun jinshan Wuhan Blasting Engineering Co. Ltd. Wuhan 430023 China College of Civil and Transportation Engineering Hohai University Nanjing 210098 China

The applications of numerical simulation in demolition blasting were *** methods of numerical simulation in demolition blasting were *** strength and weakness of the numerical methods mentioned in this paper were also indicated,***,the solid lattice model in the frame of discrete element method(DEM),which was developed by the author and his team,was detailedly *** existed problems in the current numerical simulation methods of demolition blasting were presented and the future trend of the numerical simulation is finally prospected.

关键词： demolition blasting numerical simulation discrete element method solid lattice model

在线全文

学校读者我要写书评

暂无评论

含能材料多孔颗粒床中致密波分析

兵工学报 2000年第3期21卷 212-216页

作者：贾祥瑞孙锦山解放军80811部队北京应用物理与计算数学研究所

本文采用一维两相流模型模拟了活塞驱动多孔颗粒床这一动态过程。用线方法 ( MOL)对该方程组求数值解。计算表明 ,经过短暂的非稳态过程 ,颗粒床中形成一稳态致密波 ,分析了致密波的结构以及活塞速度边界条件对致密波结构的影响规律。

关键词：致密波燃烧转爆轰两相流

财政支持下的货币发行与中美新冠肺炎疫情福利比较

在线全文

学校读者我要写书评

暂无评论

金融经济学研究 2020年第3期35卷 40-50页

作者：郭路孙金山中国社会科学院经济研究所北京100836 北京大学国家发展研究院北京100871

基于财政、货币与内生增长动态分析框架,理论上分析财政、货币对经济增长的影响机制,并用VAR检验中美真实经济中三者的关系,最后利用这种经济机制分析此次新冠肺炎对中美福利所带来的影响,结果显示,公共财政与经济增长存在稳定关系,基... 详细信息

基于财政、货币与内生增长动态分析框架,理论上分析财政、货币对经济增长的影响机制,并用VAR检验中美真实经济中三者的关系,最后利用这种经济机制分析此次新冠肺炎对中美福利所带来的影响,结果显示,公共财政与经济增长存在稳定关系,基于公共财政的货币发行也需与经济增长相匹配;虽然新冠肺炎疫情短期对两国经济增长造成了很大的冲击,但对整体福利所产生的影响并不大。因此,中国在复工、复产有序推进的情况下,应采取适度宽松的货币政策保障市场流动性;政府公共支出更应投向具有外部性的生产要素,如新基建、公共卫生和人力资本等领域。

关键词：新冠肺炎疫情货币政策财政政策经济增长

在线全文

学校读者我要写书评

暂无评论

中国潜在增长率的估算:人力资本变化的视角

中国人口·资源与环境 2021年第7期31卷 127-137页

作者：孙金山李钢汪勇北京大学国家发展研究院北京100871 中国社会科学院工业经济研究所北京100006 中国社会科学院金融研究所北京100028

中国经济从高速增长向高质量增长转换之际,增长动力也发生了变化,未来中国经济潜在增速如何演变是一个值得研究的话题。遵循内生经济增长理论中人力资本是长期经济增长的重要因素,文章构建了一个包含人力资本的增长核算方程,考虑了人力... 详细信息

中国经济从高速增长向高质量增长转换之际,增长动力也发生了变化,未来中国经济潜在增速如何演变是一个值得研究的话题。遵循内生经济增长理论中人力资本是长期经济增长的重要因素,文章构建了一个包含人力资本的增长核算方程,考虑了人力资本对潜在经济增长的影响,在生产函数中引入人力资本,运用生产函数法估算未来中国潜在经济增长率,文中考虑了三种数据来测算人力资本,除了传统的人力资本测算方法,考虑到人力资本投资的非线性和投入时间,采用大量调查问卷得来的公民科学素质作为人力资本的一个衡量指标。研究表明,在这三种情况下,C-D型生产函数中资本的产出弹性分别为0.63、0.59和0.57,这一结果与过去三十多年国民收入分配中资本的收入分配比例相近。在此基础上,结合长期经济增长潜力和短期经济波动,分别对人力资本、物质资本和技术进步进行了预测,并预测了2018—2035年中国经济的平均潜在增长率区间为5.02%~5.25%,其中2018—2025年期间为5.72%~5.91%,2026—2030年期间为4.69%~4.96%,2031—2035年期间为4.22%~4.50%。可以看出,随着物质资本投资增速和收益率不断下降,中国潜在经济增长率未来将不断下降,但由于人力资本积累的不断增加,将减缓这一下降趋势。在中国经济减速成为新常态的情形下,长期内政策考虑到对人力资本的长期持续投资,财政上加大对基础教育以及学前教育的投资,税收上鼓励对人力资本投资的税收减免;短期内政府继续实行积极的需求管理,重视投资结构的优化,加大政府对于经济周期的调节,防止经济剧烈波动,未来十五年中国还会平均保持一个5%以上的中速增长。

关键词：人力资本潜在增长率生产函数法潜在产出

爆破地震波作用下深埋圆形隧道围岩质点振动规律研究

在线全文

学校读者我要写书评

暂无评论

现代隧道技术 2014年第1期51卷 38-44页

作者：吕振利孙金山左昌群华侨大学土木工程学院泉州362021 中国地质大学(武汉)岩土钻掘与防护教育部工程研究中心武汉430074

开挖爆破产生的地震波会诱发邻近隧道的动力响应,并影响其安全和稳定。文章采用数值模拟方法,分析了爆破地震波中的P波与邻近圆形隧道的相互作用,研究了不同工况下围岩质点振动分布规律。计算结果表明,应力波通过圆洞时,围岩中质点的振... 详细信息

开挖爆破产生的地震波会诱发邻近隧道的动力响应,并影响其安全和稳定。文章采用数值模拟方法,分析了爆破地震波中的P波与邻近圆形隧道的相互作用,研究了不同工况下围岩质点振动分布规律。计算结果表明,应力波通过圆洞时,围岩中质点的振动方向将在洞壁附近发生微小的偏转,同时将使洞壁附近围岩的质点振动速度大于或小于振源速度,具有显著的质点振动缩放效应。振动频率、隧道尺寸、围岩性质,以及波长-洞径比对其质点振动速度的缩放效应的影响都较为显著。

关键词：圆形隧道爆破振动 P波数值模拟