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大断面暗挖地铁车站交叉群洞施工顺序及关键工序研究

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重庆建筑 2024年第9期23卷 49-55页

作者：赵志民涂怀宇刘建峰中国水利水电第五工程局有限公司四川成都610066 西南交通大学交通隧道工程教育部重点实验室四川成都610031 西南交通大学土木工程学院四川成都610031

为探究大断面浅埋暗挖地铁车站交叉群洞施工力学特性并给出交叉风道最优施工方案,该文依托重庆地铁4号线玉带山车站隧道工程,利用三维数值模拟的方法建立车站交叉群洞的三维模型,研究了与主洞相交的两风道先后开挖顺序、风道各部全导洞... 详细信息

为探究大断面浅埋暗挖地铁车站交叉群洞施工力学特性并给出交叉风道最优施工方案,该文依托重庆地铁4号线玉带山车站隧道工程,利用三维数值模拟的方法建立车站交叉群洞的三维模型,研究了与主洞相交的两风道先后开挖顺序、风道各部全导洞开挖或挂2 m洞门处理对群洞结构稳定性的影响。研究结果表明,越靠近车站端头处隧道拱顶沉降值越大,施工过程中临时支护结构能有效控制隧道变形和受力;3号风道各部采用挂洞门处理时与全导洞开挖相比,能降低拱顶约1.3 cm的最大沉降,拱腰处结构安全系数最大增加了22%;先行施工3号风道与先施工6号风道相比6号风道周边围岩更为稳定,3号风道周边围岩塑性区延伸范围也更小;车站隧道底部两层台阶开挖、最终临时支护的拆除这两个工序引起的拱顶测点沉降增量最大,结构的安全系数也在这两个工序有较大幅度降低,为施工过程中的关键步序。

关键词：大断面地铁车站群洞效应力学特性施工优化浅埋暗挖

老年T2DM病人肌少症发生与颈动脉粥样硬化的相关性研究

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实用老年医学 2024年第8期38卷 826-830页

作者：梁杉杉梁欢杨珊刘建凤沧州市人民医院内分泌科河北省沧州市061000

目的分析老年T2DM病人肌少症发生与颈动脉粥样硬化(AS)的相关性。方法回顾性收集本院2021年4月至2023年4月收治的97例老年T2DM病人临床资料,依据骨骼肌质量指数(ASMI)分为肌少症组41例、非肌少症组56例。收集病人临床资料及颈动脉超声指... 详细信息

目的分析老年T2DM病人肌少症发生与颈动脉粥样硬化(AS)的相关性。方法回顾性收集本院2021年4月至2023年4月收治的97例老年T2DM病人临床资料,依据骨骼肌质量指数(ASMI)分为肌少症组41例、非肌少症组56例。收集病人临床资料及颈动脉超声指标,比较2组病人一般资料、颈动脉血流动力学参数、颈动脉AS分级情况,并分析影响老年T2DM病人肌少症发生的危险因素。结果肌少症组BMI、骨密度T值、胰岛素抵抗指数(HOMA-IR)、UA、ASMI水平均低于非肌少症组,差异有统计学意义(P<0.05)。肌少症组颈动脉斑块数、Crouse积分、半定量积分、等级积分及颈动脉内中膜厚度(IMT)明显高于非肌少症组(P<0.05)。肌少症组颈动脉AS分级以3级为主,非肌少症组以0级、1级为主(P<0.05)。Logistic回归分析显示:BMI、颈动脉斑块数、颈动脉IMT、Crouse积分、半定量积分、等级积分为肌少症发生的危险因素(P<0.05)。结论老年T2DM病人肌少症发生与颈动脉AS有关,有合并动脉AS斑块者需警惕肌少症发生,需积极采取相应预防手段,以改善病情进展。

关键词：老年人 2型糖尿病肌少症颈动脉粥样硬化相关性骨骼肌质量指数

Woody species Rhus chinensis Mill. seedlings tolerance to Pb:Physiological and biochemical response

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Journal of Environmental Sciences 2019年第4期31卷 63-73页

作者： Xiang Shi Shufeng Wang Dongxue Wang Haijing Sun Yitai Chen jianfeng liu Zeping Jiang Research Institute of Subtropical Forestry Key Laboratory of Tree Breeding of Zhejiang ProvinceChinese Academy of Forestry Research Institute of Forestry Chinese Academy of Forestry Forestry College of Inner Mongolia Agricultural University

Screening potential plant species is a crucial consideration in phytoremediation *** previous study demonstrated that Rhus chinensis Mill. seedlings had potentials for phytoremediation of Pb contaminated soil. However, its bioaccumulation and tolerance characteristics remain unclear. Seedling growth, LMWOAs secreted by roots, Pb subcellular distribution and chemical forms, and mineral elements in R. chinensis tissues were evaluated under different Pb concentrations(0, 25, 50, 100, 200 and 400 mg/L) in culture solution at14 days after planting. R. chinensis did not show visual symptoms of Pb toxicity under lower Pb treatments; however, Pb significantly declined the growth of seedlings under higher Pb treatments. Higher Pb stress also decreased the concentrations of nitrogen in leaves, but increased the concentrations of P and K in roots. Pb stress also decreased Mn concentrations in leaves. A great quantity of Pb was uptake and mostly retained in R. chinensis ***, R. chinensis can still concentrate 459.3 and 1102.7 mg/kg Pb in leaves and stems,respectively. Most of Pb in R. chinensis tissues was stored in the cell wall with HAc-, HCl-, and NaC l-extractable form. LMWOAs secreted by R. chinensis roots showed a strong positive correlation with Pb concentrations in all plant tissues and with P in roots. Our results suggested that Pb deposited in the cell wall and integration with phosphate or oxalate might be responsible for the tolerance of R. chinensis under Pb stress in short period.

关键词： Lead Tolerance Subcellular distribution Chemical form Low molecular weight organic acids

Failure behavior of a rock-coal-rock combined body with a weak coal interlayer

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International Journal of Mining Science and Technology 2013年第6期23卷 907-912页

作者： Zuo Jianping Wang Zhaofeng Zhou Hongwei Pei Jianliang liu jianfeng State Key Laboratory of Coal Resources and Safe Mining China University of Mining&Technology School of Mechanics and Civil Engineering China University of Mining&Technology College of Hydraulic and Hydroelectric Engineering Sichuan University

Using an MTS 815 testing machine,the deformation and failure behavior of a rock-coal-rock combined body containing a weak coal interlayer has been investigated and described in this *** loading leads to the appearance of mixed cracks in the coal body which induce instability and lead to bursts in *** the mixed crack propagates at a sufficiently high speed to carry enough energy to damage the roof rock,then coal and rock bursts may occur-this is the main mechanism whereby coal bumps or coal and rock bursts occur after excavation *** increasing confining pressure,the failure strength of a rock-coal-rock combined body gradually increases,and the failure mechanism of the coal interlayer also changes,from mixed crack damage under low confining pressures,to parallel crack damage under medium confining pressures,and finally to single shear crack damage or integral mixed section damage under high confining *** general,it is shown that a weak coal interlayer changes the form of overall coal damage in a rock-coal-rock combined body and reduces the overall stability of a coal ***,the whole failure behavior of a rock-coal-rock combined body in large cutting height working faces is controlled by these mechanisms.

关键词： Cracks Failure (mechanical) Loading Rock bursts Rock pressure Rocks Unloading

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深埋高温硐室围岩开挖损伤规律研究

采矿与岩层控制工程学报 2024年第3期6卷 124-135页

作者：周训乾刘建锋姜海波谢良甫李洪涛周家文鲁功达四川大学山区河流保护与治理全国重点实验室四川成都610065 四川大学水利水电学院四川成都610065 新疆农业大学水利与土木工程学院新疆乌鲁木齐830052 新疆大学建筑工程学院新疆乌鲁木齐830046 成都理工大学地质灾害防治与地质环境保护国家重点实验室四川成都610059

深部工程的高地应力与高地温问题将对地下资源开采和空间利用构成严峻挑战。通过建立深埋高温硐室爆破–卸荷–降温全过程的数值模型,并嵌入率相关岩石本构关系反映钻爆开挖和通风降温过程中的岩体动静态力学响应,分析了不同地应力条件... 详细信息

深部工程的高地应力与高地温问题将对地下资源开采和空间利用构成严峻挑战。通过建立深埋高温硐室爆破–卸荷–降温全过程的数值模型,并嵌入率相关岩石本构关系反映钻爆开挖和通风降温过程中的岩体动静态力学响应,分析了不同地应力条件下围岩开挖损伤的时空演化规律。计算结果表明:围岩在动态开挖过程中会由于爆破、卸荷或两者的共同作用产生初始动力损伤,而硐室通风冷却过程所诱发的热应力将在保留岩体中造成额外的热力损伤。在静水应力条件下,围岩动力损伤随地应力量级的提高表现出先减弱后增强的演化趋势,降温损伤则随地应力的上升而单调增大。在非静水应力条件下,硐室拱顶和拱腰附近岩体的动力损伤将随侧压力系数的增大而分别表现出先减小后增大和单调增大的演化趋势;在通风冷却阶段,应力水平较低的拱腰附近未产生显著的热力损伤,而拱顶围岩的热力损伤则随侧压力系数的提升而逐渐增强。

关键词：钻爆开挖瞬态卸荷开挖损伤数值模拟原岩温度通风降温

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ZnO-based micromotors fueled by CO2: the first example of self-reorientation-induced biomimetic chemotaxis

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National Science Review 2021年第11期8卷 102-109页

作者： Fangzhi Mou Qi Xie jianfeng liu Shengping Che Lamya Bahmane Ming You Jianguo Guan State Key Laboratory of Advanced Technology for Materials Synthesis and Processing International School of Materials Science and EngineeringWuhan University of Technology

Synthetic chemotactic micro/nanomotors are envisioned to actively 'seek out' targets by following specific chemicals,but they are mainly powered by bioincompatible fuels and only show pseudochemotaxis（or advanced chemokinesis） due to their weak self-reorientation *** we demonstrate that synthetic ZnO-based Janus micromotors can be powered by the alternative biocompatible fuel of CO;2;,and further provide the first example of self-reorientation-induced biomimetic chemotaxis using *** ZnO-based micromotors are highly sensitive to dissolved CO;2;in water,which enables the corrosion of ZnO to continuously occur by providing H;+;through ***,they can autonomously move even in water exposed to air based on ***,they can sense the local CO;2;gradient and perform positive chemotaxis by self-reorientations under the phoretic *** discovery opens a gate to developing intelligent micro/nanomotors powered by,and sensitive to,biocompatible atmospheric or endogenous gaseous chemicals for biomedical and environmental applications.

关键词： micro/nanomotors zinc oxide carbon dioxide self-propulsion chemotaxis

3D reconstruction method and connectivity rules of fracture networks generated under different mining layouts

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International Journal of Mining Science and Technology 2013年第6期23卷 863-871页

作者： Zhang Ru Ai Ting Li Hegui Zhang Zetian liu jianfeng State Key Laboratory of Hydraulics and Mountain River Engineering College of Hydraulic and Hydropower EngineeringSichuan University College of Architecture and Environment Sichuan University

In current research, a series of triaxial tests, which were employed to simulate three typical mining lay-outs (i.e., top-coal caving, non-pillar mining and protected coal seam mining), were conducted on coal by using MTS815 Flex Test GT rock mechanics test system, and the fracture networks in the broken coal samples were qualitatively and quantitatively investigated by employing CT scanning and 3D reconstruc-tion techniques. This work aimed at providing a detail description on the micro-structure and fracture-connectivity characteristics of rupture coal samples under different mining layouts. The results show that: (i) for protected coal seam mining layout, the coal specimens failure is in a compression-shear manner and oppositely, (ii) the tension-shear failure phenomenon is observed for top-coal caving and non-pillar mining layouts. By investigating the connectivity features of the generated fractures in the direction of r1 under different mining layouts, it is found that the connectivity level of the fractures of the samples corresponding to non-pillar mining layout was the highest.

关键词： Coal Coal deposits Computerized tomography Rock mechanics Room and pillar mining Three dimensional

Liquid-phase a-Pinene Isomerization over Fe-doped Sulfated Zirconia Prepared by a Hydrothermal Treatment-assisted Process

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Chinese Journal of Chemistry 2011年第6期29卷 1095-1100页

作者： liu, jianfeng Zhao, Jie Miao, Changxi Yue, Yinghong Hua, Weiming Gao, Zi Shanghai Research Institute of Petrochemical Technology Shanghai 201208 China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of Chemistry Fudan University Shanghai 200433 China

A series of Fe-doped （0.5%--3%） sulfated zirconia have been prepared by a hydrothermal treatment-assisted process. Textural and structural characterizations of the as-synthesized materials were performed by means of N2 adsorption, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and thermogravimetric analysis. Temperature-programmed desorption of ammonia was used to determine the acidity of the samples. The effects of Fe-doping on the structure, acidity and catalytic activity of sulfated zirconia for liquid-phase a-pinene isornerization were investigated. The incorporation of small amounts of Fe into sulfated zirconia results in the increase of sulfate content and the number of acid sites, which is responsible for the enhanced activity of Fe-doped catalysts in comparison with the undoped one. Meanwhile, hydrothermal treatment helps to improve the activity of the catalyst.

关键词： sulfated zirconia Fe-doping hydrothermal treatment promoting effect acidity isomerization

Role of FGF-2/FGFR signaling pathway in cancer and its signification in breast cancer

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Chinese Science Bulletin 2003年第15期48卷 1539-1547页

作者： FANG Jianwu HUANG Siluo liu Huisheng M. Crepin XU Tao liu jianfeng Instiute of Biophyscis & Biochemnistry of Huazhong University of Science & Technology Wuhan 430074China CNRS-UPR 9023 Mecanismes Moleculaires des Communications CellulairesCCIPE 34090 France Laboratoire de Recherche Oncologie MoleAculaire Humaine (EA445) UFR LeAonard de Vinci UniversiteA Paris-nord 74 rue Marcel Cachin 93012BobignyFrance

Fibroblast growth factor-2 (FGF-2) is a member of a large family of proteins that bind heparin and heparan sulfate and modulate the function of a wide range of cell types. It has been proved that FGF-2 stimulates the growth and development of new blood vessels (angiogenesis) that contribute to the pathogenesis of several diseases (i.e. cancer, atherosclerosis). However, many of the biological activities of FGF-2 have been found to depend on its receptor抯 intrinsic tyrosine kinase activity and second messengers such as the mitogen activated protein kinases. This review will focus on the mechanism of FGF-2/FGFR induced signaling pathway in tumor and human breast cancer.

关键词：乳腺癌蛋白质肝磷脂硫酸乙酰肝素血管生成