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Effect of burial depth of a new tunnel on the seismic response of an existing tunnel

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 863-882页

作者： Ma Runbo Cao qikun Lu Shasha Zhao Dongxu zhang Yanan Xu Hong College of Civil Engineering Liaoning Technical UniversityFuxin 123000China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China

Burial depth is a crucial factor affecting the forces and deformation of tunnels during *** key issue is a lack of understanding of the effect of a change in the buried depth of a single-side tunnel on the seismic response of a double-tunnel *** this study,shaking table tests were designed and performed based on a tunnel under construction in Dalian,*** models were established using the equivalent linear method combined with ABAQUS finite element software to analyze the seismic response of the interacting *** results showed that the amplification coefficient of the soil acceleration did not change evidently with the burial depth of the new tunnel but decreased as the seismic amplitude *** addition,the existing tunnel acceleration,earth pressure,and internal force were hardly affected by the change in the burial depth;for the new tunnel,the acceleration and internal force decreased as the burial depth increased,while the earth pressure *** shows that the earth pressure distribution in a double-tunnel system is relatively complex and mainly concentrated on the arch spandrel and arch springing of the relative ***,when the horizontal clearance between the center of the two tunnels was more than twice the sum of the radius of the outer edges of the two tunnels,the change in the burial depth of the new tunnel had little effect on the existing one,and the tunnel structure was deemed *** results provide a preliminary understanding and reference for the seismic performance of a double-tunnel system.

关键词： burial depth new tunnel existing tunnel seismic response shaking table tests numerical simulations

Preparation and characterization of solidified oleanolic acid–phospholipid complex aiming to improve the dissolution of oleanolic acid

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Asian Journal of Pharmaceutical Sciences 2016年第2期11卷 241-247页

作者： Xiaoxu Yang qikun Jiang Ping Du Juanhang Zhao Tianhong zhang School of Pharmacy Shenyang Pharmaceutical University

The purpose of this study was to prepare the oleanolic acid–phospholipid complex (OAPC) and then solidify it employing fumed silica by simple solvent evaporation technique to improve dissolution rate of oleanolic acid and oleanolic acid–phospholipid complex. The process of OA-PC was optimized and the type and proportion of fumed silica were studied by dissolution text. The structures of the phospholipid complex and solidified powder were also characterized by differential scanning calorimetry, X-ray diffraction, and scanning electron microscope. In the dissolution tests, OA from solidified powder was further released compared with that from pure OA and OA-PC in different kinds of dissolution media. These results suggest that the method of preparing solidified powder of oleanolic acid–phospholipid complex is suitable for enhancing the dissolution rate of OA and OA-PC.

关键词： Oleanolic acid Phospholipid complex Fumed silica Dissolution

Driver-automation shared steering control considering driver neuromuscular delay characteristics based on stackelberg game

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Green Energy and Intelligent Transportation 2022年第2期1卷 88-96页

作者： Jun Liu Hongyan Guo Wanqing Shi qikun Dai Jiaming zhang State Key Laboratory of Automotive Simulation and Control Jilin UniversityRenmin Street 5988Changchun130025China College of Communication Engineering Jilin UniversityRenmin Street 5988Changchun130025China

To promote the intelligent vehicle safety and reduce the driver steering workload,stackelberg game theory is adopted to design the shared steering control strategy that takes the driver neuromuscular delay characteristics into ***,a shared steering control framework with adjustable driving weight is proposed,and a coupling interaction model considering the driver neuromuscular delay characteristics is constructed by using the stackelberg game ***,the driver-automation optimal control strategy is deduced theoretically when the game equilibrium is ***,simulation and virtual driving tests are carried out to verify the superiority of the proposed *** results illustrate that the raised method can enhance the vehicle safety with low driving weight intervention,and it can achieve better auxiliary effect with less control *** addition,the driver-in-the-loop test results show that the proposed strategy can achieve better performance in assisting drivers with low driving skills.

关键词： Shared steering control Game theory Driver-automation interaction Driver neuromuscular delay characteristics

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两种比色法检测水体中微量氨含量的比较研究

大学化学 2019年第3期34卷 36-41页

作者：王佳敏李涵张文凯刘承上刘宝良孙华宇张其坤山东师范大学化学化工与材料科学学院化学国家级实验教学示范中心济南250014 邯郸市第一中学河北邯郸056001 山东师范大学附属中学济南250014

氨氮含量的高低是衡量湖泊和水库水体富营养化的指标之一,水体中的氮元素极易诱发水体富营养化。目前,国标中通过比色法来检测氨氮含量的方法主要有靛酚蓝分光光度法和纳氏试剂分光光度法。根据高等教育国家标准中对于培养大学生的创新... 详细信息

氨氮含量的高低是衡量湖泊和水库水体富营养化的指标之一,水体中的氮元素极易诱发水体富营养化。目前,国标中通过比色法来检测氨氮含量的方法主要有靛酚蓝分光光度法和纳氏试剂分光光度法。根据高等教育国家标准中对于培养大学生的创新实践、科研意识、实验动手能力的要求,依照检测水体中氨氮含量的国家标准,检测了济南市区内三大名泉(趵突泉、黑虎泉、五龙潭)、大明湖、聊城东昌湖以及天津海河的水体样品中的氨氮浓度,并把山东师范大学的生活自来水作为对比样品,比较了比色法检测水体中氨氮含量的两种检测方法的差异。更重要的是,学生从检测过程中的得失领悟到了采用比色法检测、分析样品的方法技巧。结果表明,通过不断地完善检测方案,两种方法的标准曲线相关系数均达到0.9999以上。在实验操作中,由于操作过程和操作手法的不同(例如显色剂浓度、标准溶液的取用技巧以及各溶剂混合之后放置时间的长短等),获得了不同的实验结果,对实验结果的异常现象出现的原因进行了分析,同时讨论了两种检测方法的不同。

关键词：靛酚蓝法纳氏试剂法比色法氨氮含量吸光度

Theoretical connection from the dielectric constant of films to the capacitance of capacitors under high temperature

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High Voltage 2023年第4期8卷 707-716页

作者： Yongxin zhang qikun Feng Shaolong Zhong Jiayao Pei Fangyi Chen Lei Huang Zhe Yang Zhimin Dang Department of Electrical Engineering Tsinghua UniversityBeijingChina Department of Electrical and Computer Engineering Carnegie Mellon UniversityPittsburghPennsylvaniaUSA Department of Energy Technology Aalborg UniversityAalborgDenmark

In the process of coping with energy and environmental protection issues,technologies such as energy materials,energy devices,and energy systems have made great *** excellent performance,film capacitors play an increasingly important role in energyrelated *** the increase of application scenarios and the continuous development of film material technology,it is urgent to establish a better theoretical connection from films to ***,the main components of the capacitor including the film and the positional relationships among them are ***,from the two perspectives of indirect calculation according to the volume and the direct calculation according to the winding process,the equation between the dielectric constant of films and the corresponding capacitance of capacitors is ***,the measurement data and error analysis results of the built test platform prove the accuracy and great potential of the proposed calculation *** addition,error sources,including film thickness uniformity,are ***,the challenges faced by the proposed calculation methods and the paths that can be referenced for future research are summarised and discussed.

关键词： film dielectric capacitance

Nanoscale superconductivity of ?-Ga islands grown by molecular beam epitaxy

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Science China(Physics,Mechanics & Astronomy) 2015年第10期58卷 89-93页

作者： zhang HuiMin PENG JunPing GUAN JiaQi LI Zhi SONG CanLi WANG LiLi HE Ke MA XuCun XUE qikun Institute of Physics Chinese Academy of Sciences State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Collaborative Innovation Center for Quantum Matter

We report on the preparation and superconductivity of metastable γ-Ga islands on Si(111) substrate. The Ga grows in a typical Volmer-Weber mode at a low temperature of 110 K, resulting in formation of Ga nanoislands at various sizes with the identical γ-phase. In-situ low temperature scanning tunneling spectra reveal quantized electronic states in ultrathin Ga islands. It is found that both the lateral size and thickness of the Ga islands strongly suppress the superconductivity. Due to substantial surface energy contribution, the transition temperature Tc scales inversely with the island thickness and the minimum thickness for the occurrence of superconductivity is calculated to be two monolayers.

关键词： γ-Ga superconductivity size effects molecular beam epitaxy

手术切除与射频消融治疗血管周围型单发小肝癌临床疗效分析

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中华肝脏外科手术学电子杂志 2023年第5期12卷 523-527页

作者：张海涛贾哲马超张其坤武聚山郭庆良曾道炳栗光明王孟龙首都医科大学附属北京佑安医院普通外科、首都医科大学肝癌临床诊疗及研究中心 100069

目的探讨手术切除与射频消融(RFA)治疗血管周围型单发小肝癌临床疗效。方法回顾性分析2015年1月至2018年12月在首都医科大学附属北京佑安医院治疗的219例血管周围型单发小肝癌患者临床资料。其中男169例,女50例;年龄34~76岁,中位年龄55... 详细信息

目的探讨手术切除与射频消融(RFA)治疗血管周围型单发小肝癌临床疗效。方法回顾性分析2015年1月至2018年12月在首都医科大学附属北京佑安医院治疗的219例血管周围型单发小肝癌患者临床资料。其中男169例,女50例;年龄34~76岁,中位年龄55岁;肿瘤≤4 cm。121例患者行肝切除治疗(LR组),98例行RFA治疗(RFA组)。患者均签署知情同意书,符合医学伦理学规定。采用倾向性评分匹配(PSM)对患者进行1∶1匹配,分析PSM后两组术后肝内复发、肝外复发、无进展生存期(PFS)及总体生存期(OS)。生存分析采用Kaplan-Meier和Log-rank检验。结果PSM后两组各60例患者,LR组术后1、3、5、7年PFS分别为93.7%、69.0%、58.0%、53.8%,RFA组相应为89.2%、45.4%、30.1%、14.1%,LR组术后PFS明显优于RFA组(HR=1.09,P0.05)。亚组分析结果显示,LR组门静脉周围型肝癌患者肝内复发、肝外复发、PFS和OS均明显优于RFA组(HR=0.24,0.68,0.25,0.22;P<0.05);而LR组肝静脉周围型肝癌患者仅肝内复发优于RFA组(HR=0.16,P<0.05)。结论对于血管周围型单发小肝癌,手术切除提供了较RFA更好的长期肿瘤控制和OS,特别是对于门静脉周围型肝癌的患者,如果具备手术切除的条件,应将手术切除作为首选。

关键词：癌,肝细胞射频消融肝切除术倾向性评分匹配血管周围型肝癌

In situ Raman spectroscopy of topological insulator Bi2Te3 films with varying thickness

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Nano Research 2013年第9期6卷 688-692页

作者： Chunxiao Wang Xiegang Zhu Louis Nilsson Jing Wen GuangWang Xinyan Shan Qing zhang Shulin zhang Jinfeng Jia qikun Xue State Key Laboratory for Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing 100084 China DepartmentofPhysics Peking University Beijing 100871 China Department of Physics andAstronomy and Interdisciplinary Nanoscience Center Aarhus University 8000 Aarhus C Denmark Department of Physics Shanghai Jiaotong University Shanghai200240 China

Topological insulators （TIs） are a new state of quantum matter with a band gap in bulk and conducting surface states. In this work, the Raman spectra of topological insulator Bi2Te3 films prepared by molecular beam epitaxy （MBE） have been measured by an in situ ultrahigh vacuum （UHV）-MBE-Raman spectroscopy system. When the thickness of Bi2Te3 films decreases from 40 quintuple-layers （QL） to 1 QL, the spectral characteristics of some Raman modes appearing in bulk Bi2Te3 vary and a new vibrational mode appears, which has not been reported in previous studies and might be related to quantum size effects and symmetry breaking. In addition, an obvious change was observed at 3 QL when a Dirac cone formed. These results offer some new information about the novel quantum states of TIs.

关键词： topological insulator in situ Raman spectroscop^surface phonon mode thin film

Observation of unconventional anomalous Hall effect in epitaxial CrTe thin films

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Nano Research 2018年第6期11卷 3116-3121页

作者： Dapeng Zhao Liguo zhang Iftikhar Ahmed Malik Menghan Liao Wenqiang Cui Xinqiang Cai Cheng Zheng Luxin Li Xiaopeng Hu Ding zhang Jinxing zhang Xi Chen Wanjun Jiang qikun Xue State Key Laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University Beijing 100084 China Department of Physics Beijing Normal University Beijing 100875 China Collaborative Innovation Center of Quantum Matter Beijing 100084 China

We have studied the magnetic and electrical transport properties of epitaxial NiAs-type CrTe thin films grown on SrTiO3（111） substrates. Unlike rectangle hysteresis loops obtained from magnetic measurements, we have identified intriguing extra bump/dip features from anomalous Hall experiments on the films with thicknesses less than 12 nm. This observed Hall anomaly is phenomenologically consistent with the occurrence of a topological Hall effect （THE） in chiral magnets with a skyrmion phase. Furthermore, the THE contribution can be tuned by the film thickness, showing the key contribution of asymmetric interfaces in stabilizing N6el-type skyrmions. Our work demonstrates that a CrTe thin film on SrTiO3（111） substrates is a good material candidate for studying real-space topological transport.

关键词： topological Hall effect CrTe films skyrmion phase molecular beam epitaxy