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城市轨道交通信号系统设施设备维护表现评估

价值工程 2024年第3期43卷 44-46页

作者：顾佳樑袁建军楚彭子上海申通地铁集团有限公司运营设施设备管理部上海201103 同济大学磁浮交通工程技术研究中心上海201804 上海申通地铁集团有限公司技术中心上海201103

信号系统在城市轨道交通运营中发挥着关键控制作用,对列车的可靠运行至关重要。设施设备的维护是保证信号系统持续正常工作的前提之一。针对信号系统设施设备维护表现,构建了维护表现评估指标体系,并结合物元分析法给出了具体的评估方... 详细信息

信号系统在城市轨道交通运营中发挥着关键控制作用,对列车的可靠运行至关重要。设施设备的维护是保证信号系统持续正常工作的前提之一。针对信号系统设施设备维护表现,构建了维护表现评估指标体系,并结合物元分析法给出了具体的评估方法。算例分析结果显示方法是有效的。

关键词：城市轨道交通信号系统设施设备维护表现

Partitioning of heavy metals in the surface sediments of Quanzhou Bay wetland and its availability to Suaeda australis

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Journal of Environmental Sciences 2006年第2期18卷 334-340页

作者： LI Yu-hong YAN Chong-ling yuan jian-jun LIU Jing-chun CHEN Huai-yu HU jun School of Life Sciences Xiamen University Xiamen 361005 China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China iology Department of Quanzhou Normal College Quanzhou 362000 China

In order to investigate distributions of heavy metal pollution in Quanzhou Bay wetland, the total concentration and chemical partitioning of a number of heavy metals （Cu, Zn, Cd, Pb, Cr, Hg） in sediments of three sampling sites of Quanzhou Bay wetland and their availability to Suaeda australis were analyzed. The Geoaccumulation Index （Igeo） values reveal that the sediments of three sampling sites may all be considered as moderately contaminated for Pb and Zn, and all sediments might be strongly contaminated with cadmium. The partitioning analyses revealed the measured heavy metals in three sites are bound to the exchangeable fraction at lower concentrations. The measured metals in a considerable amount are bound to the reducible and oxidizable fractions, and a high proportion of the measured heavy metals were distributed in the residual fraction in the sediment samples. The concentrations of Cd in each chemical phase extracted from the sediments are above natural global background levels and should be further investigated because of its toxicity. Suaeda australis has different accumulation abilities for the measured heavy metals. For the root and stem, the bioaccumulation ability assessed by bioaccumulation factor （BAF） for the measured heavy metals follows the decreasing order as： Cu〉Cr〉 Zn〉Cd, Pb, Hg. In the leaf, stronger bioaccumulation ability for Hg is exhibited. The heavy metal concentrations in Suaeda australis roots have positive correlations with their available fractions, while the exchangeable fraction of Cu and Cd might have be more important to both mature plant roots and seedling roots uptake than other fractions; as for Cr, the oxidizable fraction might make a greater contribution to the plant root uptake; as for Zn, the reducible fraction might make so contribution ; and for Pb, the oxidizable fraction might make a significant contribution to the mature plant root uptake, however, the exchangeable fraction might have a significant contribution to th

关键词： bioavailability geoaccumulation factor partitioning heavy metals Suaeda australis sediment Quanzhou Bay wetland

Apoptosis and necrosis of HeLa cells in response to low-energy ion radiation

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Nuclear Science and Techniques 2006年第4期17卷 222-226页

作者： ZHANG Feng-Qiu YA Hui-yuan LI Jing-yuan PENG jian-jun FANG Hua-Sheng SU Ming-Jie QIN Guang-Yong Henan Key Lab of lonbeam Bioengineering Zhengzhou University Zhengzhou 450052 China

The aim of this study was to investigate the damage of low-energy ions to HeLa cells and to particularly examine the relationship between apoptotic and necrotic effects and the low-energy ion radiation. In this study, HeLa cells were irradiated by low-energy ions (30keV N+) at different doses. The level of apoptosis and necrosis was evalu- ated using flow cytometry. Since vacuum is required for experimental low-energy ion generation and irradiation, the cells must be placed in vacuum. Mineral oil was used to prevent dehydration of cells. The results show that the apoptotic rate reached 7.09% when the ion implantation dose was 1 × 1015 ions/cm2; and when the cells were exposed to and implanted at 2 × 1015 ions/cm2 dose, the apoptotic rate was higher than that at 1 × 1015 ions/cm2, and the necrotic rate was 15.63%. In addition, the survival fraction gradually decreased with the increase in implantation dose. Some rela- tionships have been found between the radiation-induced apoptosis and the incubated time after irradiation.

关键词：人宫颈癌传代细胞细胞凋亡细胞增殖低能离子辐射流式细胞测量术

PRESSURE DISTRIBUTION ON THE WALL OF THE INNER CYLINDER RECIPROCATING AXIALLY TO THE UNSTEADY FLOW OF VISCOELASTIC FLUID IN ECCENTRIC ANNULUS

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Journal of Hydrodynamics 2006年第5期18卷 606-612页

作者： WANG Yan CUI Hai-qing YANG yuan-jian GUO jun-hui LI Nan Department of Petroleum Engineering China University of Petroleum Beijing 102249 China Department of Petroleum Engineering Daqing Petroleum Institute Daqing 163318 China

In this article, the governing equations for the unsteady flow of viscoelastic fluid in the eccentric annulus with the inner cylinder reciprocating axially and the expression of the pressure distribution on the wall of the inner cylinder of the annulus are established and derived, respectively, under the bipolar coordinate system. The equations and the expression are solved and calculated numerically using the finite difference method, respectively. The curves of the pressure distribution on the wall of the inner cylinder of the aqueous solution of Hydrolyzed Polyacrylamide （HPAM） are plotted and the influences of annular eccentricity, stroke, and stroke frequency on the pressure distribution are analyzed.

关键词： viscoelastic unsteady flow eccentric annulus fluid reciprocating axially pressure distribution

失眠、高敏C反应蛋白与腰痛和下肢疼痛共病之间关系的双向研究

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颈腰痛杂志 2024年第4期45卷 630-633,638页

作者：张权田融刘岩任志帅李广袁建军天津市人民医院脊柱科天津300121

目的探讨失眠、高敏C反应蛋白(hs-CRP)与慢性腰痛(LBP)和下肢疼痛共病之间关系的双向研究。方法选择该科2021年6月-2023年6月收治的60~85岁老年人289例进行研究,观察失眠、hs-CRP、慢性LBP、下肢疼痛之间的关系。结果慢性LBP患者和非慢... 详细信息

目的探讨失眠、高敏C反应蛋白(hs-CRP)与慢性腰痛(LBP)和下肢疼痛共病之间关系的双向研究。方法选择该科2021年6月-2023年6月收治的60~85岁老年人289例进行研究,观察失眠、hs-CRP、慢性LBP、下肢疼痛之间的关系。结果慢性LBP患者和非慢性LBP人群年龄、性别、教育程度、慢性阻塞性肺病、hs-CRP、失眠发生率存在统计学意义(P0.05)。失眠和非失眠人群年龄、教育程度、体力活动、心血管疾病、慢性阻塞性肺疾病、hs-CRP等差异存在统计学意义(P0.05),hs-CRP不是影响慢性LBP、慢性下肢痛、慢性LBP合并下肢痛、失眠的风险因素(P>0.05);慢性LBP、慢性下肢痛不是影响失眠的风险因素(P>0.05),慢性LBP合并下肢痛是失眠的风险因素(P<0.05)。结论失眠和慢性腰痛和下肢疼痛之间不存在显著的双向相关,但失眠可增加慢性LBP的风险,同时患有LBP和下肢疼痛的患者存在失眠风险,hs-CRP对失眠、慢性腰痛和下肢疼痛的发生无明显影响。

关键词：慢性腰痛下肢疼痛失眠高敏C反应蛋白

Preparation and Rheological Characterization of Long Chain Branching Polyglycolide

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Chinese Journal of Polymer Science 2024年第8期42卷 1177-1184页

作者： Wei-Lin Liu Ming-Fu Lyu Heng-yuan Zhang jian-Ye Liu Shi-jun Zhang Beijing University of Chemical Technology Beijing 100029China SINOPEC(Beijing)Research Institute of Chemical Industry Co. Ltd.Beijing 100013China

The long chain branching(LCB)polyglycolide(PGA)was successfully prepared by the successive reactions of the terminal hydroxyl groups of PGA with triglycidyl isocyanurate(TGIC)and pyromellitic dianhydride(PMDA).The influence of LCB produced by functional group reaction on rheological and crystallization behavior was studied and discussed through linear rheology,uniaxial elongation and DSC(differential scanning calorimetry).The much higher viscosity and the more notable strain hardening behavior of modified PGA indicates the LCB with high degree of entanglements are *** melt strength of PGA is finally improved greatly and can make su re that the supercritical CO_(2)foaming can be carried out successfully.

关键词： Polyglycolide(PGA) Long chain branching(LCB) Rheology

Study of primordial deuterium abundance in Big Bang nucleosynthesis

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Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： Zhi-Lin Shen jian-jun He Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

Clinical value of contrast-enhanced ultrasonography in the characterization of focal liver lesions:a prospective multicenter trial

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Hepatobiliary & Pancreatic Diseases International 2009年第4期8卷 370-376页

作者： Wang, Wen-Ping Wu, Ying Luo, Yan Li, Rui Zhou, Xiao-Dong Zhang, jun Qian, Chao-Wen Tan, Xu-Yan Xu, Qing-Hua Wang, Yan yuan, jian-jun Fudan Univ Zhongshan Hosp Dept Diagnost Ultrasound Shanghai 200032 Peoples R China Shenzhen Peoples Hosp Dept Ultrasound Shenzhen 518020 Peoples R China Sichuan Univ Dept Ultrasound W China Hosp Chengdu 610041 Peoples R China Chongqing SW Hosp Dept Ultrasound Chongqing 400038 Peoples R China Fourth Mil Med Univ Dept Diagnost Ultrasound Xijing Hosp Xian 710032 Peoples R China Jilin Prov Canc Hosp Dept Electrodiag Changchun 130012 Peoples R China Zhejiang Prov Canc Hosp Dept Ultrasound Hangzhou 310022 Zhejiang Peoples R China jiangsu Prov Canc Hosp Dept Ultrasound Nanjing 210009 Peoples R China First Peoples Hosp Foshan Dept Diagnost Ultrasound Foshan 528000 Peoples R China Henan Prov Canc Hosp Dept Ultrasound Zhengzhou 450003 Peoples R China Peoples Hosp Henan Prov Dept Diagnost Ultrasound Zhengzhou 450003 Peoples R China

BACKGROUND: Contrast-enhanced ultrasonography (CEUS) is increasingly accepted in clinical settings for diagnostic imaging of focal liver lesions (FLLs). This study aimed to assess the efficacy of CEUS in the characterization of FLLs in comparison with final diagnosis based on gold standard assessment. METHODS: The study was approved by the local ethics committee and participating patients provided written informed consent. A total of 148 patients with 164 FLLs were studied. Unenhanced ultrasonography (US) and CEUS were performed using fundamental and harmonic imaging, respectively. Contrast enhancement was assessed during the arterial, portal and late vascular phases after intravenous administration of contrast (SonoVue (R), Bracco, Italy). Sensitivity, specificity and diagnostic accuracy of US and CEUS were compared in identifying the lesion as benign, malignant or indeterminate and its actual tumor type. Final diagnosis was established by biopsy (129/164), MR imaging (11/164) or medical history (24/164). RESULTS: When compared to the gold standard, the number of indeterminate diagnoses was reduced from 56.7% (93/164) as assessed by fundamental imaging to 6.1% (10/164) after SonoVue (R) enhanced US examination. Sensitivity and specificity improved from 49% and 25% at baseline US to 93% and 75% with CEUS, respectively (P<0.01). Diagnostic accuracy of CEUS was 88% in contrast to 41% of baseline US. CONCLUSION: SonoVue (R) enhanced US improves the characterization of FLLs and may limit the need for further investigations.

关键词： contrast-enhanced ultrasonography characterization focal liver lesions

Global Spherically Symmetric Solutions for a Coupled Compressible Navier–Stokes/Allen–Cahn System

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Acta Mathematica Sinica,English Series 2024年第8期40卷 2037-2064页

作者： Chang Ming SONG jian Lin ZHANG yuan yuan WANG Department of Applied Mathematics School of Mathematics and Information ScienceZhongyuan University of TechnologyZhengzhou 450007P.R.China

In this paper,we consider the global spherically symmetric solutions for the initial boundary value problem of a coupled compressible Navier–Stokes/Allen–Cahn system which describes the motion of two-phase viscous compressible *** prove the existence and uniqueness of global classical solution,weak solution and strong solution under the assumption of spherically symmetry condition for initial dataρ0 without vacuum state.

关键词： Diffuse interface model global solutions Navier-Stokes equations Allen-Cahn equation spherically symmetry