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高速铁路路基填料智能振动压实系统研制与试验研究

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铁道学报 2024年第6期46卷 138-147页

作者：谢康陈晓斌肖宪普李泰灃张千里尧俊凯中南大学土木工程学院湖南长沙410075 中国铁道科学研究院集团有限公司铁道建筑研究所北京100081 石家庄铁道大学土木工程学院河北石家庄050043

针对现有振动压实设备的局限性,研制一种振动参数调节广、能够实时监测填料干密度的室内智能振动压实设备,并进一步量化评估填料压实状态动刚度和强度的新指标。基于振动理论,揭示室内振动压实设备稳定工作机制,提出振动参数动态优化方... 详细信息

针对现有振动压实设备的局限性,研制一种振动参数调节广、能够实时监测填料干密度的室内智能振动压实设备,并进一步量化评估填料压实状态动刚度和强度的新指标。基于振动理论,揭示室内振动压实设备稳定工作机制,提出振动参数动态优化方法,基于表面沉降理论提出干密度实时计算方法,结合压密曲线建立压实性能评估方法,分别从滞后角修正刚度理论和相似修正强度理论,提出刚度和强度等力学指标对压实状态进行综合评估方法;研发室内振动压实系统以及数据采集分析软件,分析系统部件的工作性能和指标的测试计算方法;最后,开展室内振动压实试验。研究结果发现,增大容器直径和设备自重可显著提高填料干密度;当系统处于共振频率下,填料动刚度减小,承载能力增大;基于振动参数动态优化方法,能够有效减少30%振动能量输出,进一步提高压实效率,减少压实器械磨损及颗粒破碎。研究成果有助于加深对振动压实成型机理的分析,为振动压实试验方法在高速铁路路基建设中推广应用提供理论基础。

关键词：高速铁路路基振动压实振动理论参数优化表面沉降法压实状态

不同含水率下级配碎石振动压实状态评价与机理研究

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铁道学报 2024年第2期46卷 150-158页

作者：谢康李泰灃肖宪普陈晓斌张千里王业顺中国铁道科学研究院集团有限公司铁道建筑研究所北京100081 中南大学土木工程学院湖南长沙410075 石家庄铁道大学土木工程学院河北石家庄050043

以重锤击实法中的最优含水率为高速铁路基床级配碎石振动压实法中含水率确定标准,振动压实过程中产生冒泥现象,劣化了级配碎石的压实质量。为研究含水率对振动压实法的影响机制,以不同土体结构类型的级配碎石为研究对象,通过大型室内振... 详细信息

以重锤击实法中的最优含水率为高速铁路基床级配碎石振动压实法中含水率确定标准,振动压实过程中产生冒泥现象,劣化了级配碎石的压实质量。为研究含水率对振动压实法的影响机制,以不同土体结构类型的级配碎石为研究对象,通过大型室内振动压实和三轴试验,分析不同含水率级配碎石的压实状态变化规律。研究结果表明,干密度随着含水率的增大呈先减小后增大的趋势,存在波谷,且含水率过高时,振动压实中会出现粗粒料黏着、冒泥等现象;采用压实烘干后,临界含水率作为振动压实法的加水量,压实中未产生翻浆现象,且干密度满足现场碾压标准;临界含水率下CEI和TDI处于最佳区间,颗粒破碎率最低,同时保证压实后填料的刚度、强度最大;基于临界状态土力学理论,解释孔隙水对填料振动压实的影响,即在含水率超过临界含水率后、外界总应力保持不变的情况下,孔隙水压力增大,土体有效应力减小,导致成型后填料强度下降。研究成果可为高速铁路粗粒土填筑控制提供理论参考。

关键词：高速铁路路基振动压实临界含水率智能压实压实机理

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含黄铁矿填料的高速铁路路基上拱特性与机理

中国铁道科学 2024年第4期45卷 12-21页

作者：邓逆涛陈锋张千里尧俊凯王鹏程刘景宇张栋郭云龙中国铁道科学研究院集团有限公司铁道建筑研究所北京100081 中国铁道科学研究院集团有限公司高速铁路轨道系统全国重点实验室北京100081

黄铁矿氧化膨胀对建筑物、铁路、公路等结构的影响较大,易引发结构物上拱。通过现场勘察、矿物成分分析和变形监测,系统研究含黄铁矿填料路基上拱病害特征,探究摩擦板及端刺结构型式、路基填料高度对路基上拱变形的影响,分析黄铁矿氧化... 详细信息

黄铁矿氧化膨胀对建筑物、铁路、公路等结构的影响较大,易引发结构物上拱。通过现场勘察、矿物成分分析和变形监测,系统研究含黄铁矿填料路基上拱病害特征,探究摩擦板及端刺结构型式、路基填料高度对路基上拱变形的影响,分析黄铁矿氧化膨胀反应机理和膨胀特性,以明确路基上拱原因。结果表明:所有上拱区段路基填料均检测出含有少量黄铁矿和石膏;上拱变形主要产生在路基高度范围内,线路开通后路基以0.13~0.46 mm·m^(-1)的速率持续上拱;半填半挖区段轨道结构的上拱量沿路基横向随填方高度的降低呈递减关系;路桥过渡段范围轨道垂向变形特征与摩擦板及端刺结构型式密切相关,摩擦板及端刺结构对路基上拱变形存在抑制作用;黄铁矿氧化是一个长久且持续过程,其生成硫酸盐引发的一系列化学反应所伴随的体积膨胀是造成路基上拱的主要原因;为彻底消除该隐患,应对含黄铁矿填料采取暗挖置换措施。

关键词：高速铁路路基上拱黄铁矿氧化摩擦板端刺结构变形监测矿物成分分析

腹腔镜子宫肌瘤剔除术联合宫瘤消胶囊治疗子宫肌瘤患者的临床效果

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临床医学工程 2024年第3期31卷 271-272页

作者：陈慧芳王芳张倩丽新郑华信民生医院妇产科河南郑州451100

目的探讨腹腔镜子宫肌瘤剔除术联合宫瘤消胶囊治疗子宫肌瘤患者的临床效果。方法将96例子宫肌瘤患者随机分为对照组(48例)和观察组(48例),对照组采用腹腔镜子宫肌瘤剔除术治疗,观察组在对照组基础上采用宫瘤消胶囊治疗,比较两组的治... 详细信息

目的探讨腹腔镜子宫肌瘤剔除术联合宫瘤消胶囊治疗子宫肌瘤患者的临床效果。方法将96例子宫肌瘤患者随机分为对照组(48例)和观察组(48例),对照组采用腹腔镜子宫肌瘤剔除术治疗,观察组在对照组基础上采用宫瘤消胶囊治疗,比较两组的治疗效果。结果观察组治疗总有效率为93.75%,高于对照组的79.17%(P<0.05)。治疗后,观察组血清LH、E_(2)、FSH水平低于对照组(P<0.05)。术后随访6个月,观察组复发率为2.08%,低于对照组的14.58%(P<0.05)。结论腹腔镜子宫肌瘤剔除术联合宫瘤消胶囊治疗子宫肌瘤患者,可明显提升临床疗效,改善患者性激素水平,降低复发率。

关键词：子宫肌瘤腹腔镜子宫肌瘤剔除术宫瘤消胶囊临床疗效性激素

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山区既有线降雨预警曲面研究

铁道建筑 2024年第4期64卷 96-100页

作者：刘振宇赵有明张新冈马鹏李泰灃张千里中国铁道科学研究院研究生部北京100081 中国铁道科学研究院集团有限公司北京100081 中国铁道科学研究院集团有限公司铁道建筑研究所北京100081 高速铁路轨道系统国家重点实验室北京100081 中国铁路上海局集团有限公司合肥高铁基础设施段合肥230011

对某山区既有线路基边坡溜坍风险点的地形特征以及降雨特征展开调研,得到该线路路堑边坡典型参数;基于提高多种致灾降雨类型条件下的预警成功率现实要求,提出以有效累积降雨量、时激发降雨量、降雨历时作为降雨预警空间建立降雨预警曲面... 详细信息

对某山区既有线路基边坡溜坍风险点的地形特征以及降雨特征展开调研,得到该线路路堑边坡典型参数;基于提高多种致灾降雨类型条件下的预警成功率现实要求,提出以有效累积降雨量、时激发降雨量、降雨历时作为降雨预警空间建立降雨预警曲面;运用2012—2019年降雨数据统计分析确定了适用于该线路溜坍病害的降雨预警曲面参数,对比分析了相同区段内降雨预警曲面与传统I‐D降雨预警曲线的预警效果,并采用2020年降雨数据对该降雨预警曲面进行了验证。结果表明:应用降雨预警曲面可对山区既有铁路溜坍病害进行有效预警,预警成功率达到90%。

关键词：山区铁路降雨浅层溜坍降雨预警曲面统计分析

DRAGON-Lab―Next generation internet technology experiment platform

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Science in China(Series F) 2008年第11期51卷 1908-1918页

作者： WANG JiLong LI ZhongHui LV GuoHan JIANG CaiPing LI Xing zhang qianli National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Network Research-Center Tsinghua University Beijing 100084 China

Testbed technology is very important in the development of the Internet. Similar to the present internet, next generation internet also starts from testbed. There are two kinds of testbeds, testbed networks like CNGI-CERNET2, Internet2, Geant; testbed systems like PlanetLab, NS2. DRAGON-Lab can be viewed as both testbed network and testbed system. DRAGON-Lab is an independent AS （autonomous system） and connected to multiple real networks. On the other hand, DRAGON-Lab integrates many resources of its own, partners＇ and internet＇s, so as to provide open service. DRAGON-Lab has a large scale, provides open service, supports remote visualized experiments and programmable experiments. More details will be introduced in this paper.

关键词： Internet testbed system confederation

Novel mutation c.1210-3C>G in cis with a poly-T tract of 5T affects CFTR mRNA splicing in a Chinese patient with cystic fibrosis

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Frontiers of Medicine 2022年第1期16卷 150-155页

作者： Xinyue Zhao Keqiang Liu Wenshuai Xu Meng Xiao qianli zhang Jiaxing Song Keqi Chen Yaping Liu Xinlun Tian Kai-Feng Xu Xue zhang McKusick-zhang Center for Genetic Medicine State Key Laboratory of Medical Molecular BiologyInstitute of Basic Medical SciencesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China Department of Pulmonary and Critical Care Medicine Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

Cystic fibrosis(CF)is a rare autosomal recessive disease with only one pathogenic gene cystic fibrosis transmembrane conductance regulator(CFTR).To identify the potential pathogenic mutations in a Chinese patient with CF,we conducted Sanger sequencing on the genomic DNA of the patient and his parents and detected all 27 coding exons of CFTR and their flanking intronic *** patient is a compound heterozygote of c.2909G>A,***970Asp in exon 18 and c.1210-3C>G in cis with a poly-T of 5T(T5)sequence,3 bp upstream in intron *** splicing effect of c.1210-3C>G was verified via minigene assay in vitro,indicating that wild-type plasmid containing c.1210-3C together with T7 sequence produced a normal transcript and partial exon 10-skipping-transcript,whereas mutant plasmid containing c.1210-3G in cis with T5 sequence caused almost all mRNA to skip exon ***,c.1210-3C>G,the newly identified pathogenic mutation in our patient,in combination with T5 sequence in cis,affects the CFTR gene splicing and produces nearly no normal transcript in ***,this patient carries a ***970Asp mutation,thus confirming the high-frequency of this mutation in Chinese patients with CF.

关键词： cystic fibrosis CFTR splicing mutation minigene

Detection of Denial-of-service Attacks

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计算机工程 2002年第S1期28卷 86-91页

作者： Anh Quang Tran, zhang qianli , LI Xing (Tsinghua University, Beijing 100084, China) Tsinghua University Beijing 100084 China

Denial-of-service (DOS) is a type of computer attack, which can essentially disable computers and networks. Resource consumption type of DOS attack could not be detected by the traditional misuse detection technique. This paper presents a new method of support vector mchine (SVM) to detect these attacks. We find that a DOS attack to a host is related to the activities within an impact data set of the host. The SVM method is used to classify the subsets of an impact data set to estimate its anomalism. The experiment result shows that this method can detect resource consumption type of DOS attacks, such as SYN-flood, Smurf and UDP-storm. A receiver operating characteristic curve is plotted to determine performance for any possible operating point of the DOS attacks detection.

关键词： Denial-of-service attack Support vector machine Intrusion detection Receiver operating characteristic

Numerical analysis for permafrost temperature field in the short term of permafrost subgrade filling

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Railway Sciences 2023年第2期2卷 179-196页

作者： Yunjia Wang qianli zhang Railway Science and Technology Research and Development Center China Academy of Railway Sciences Corporation LimitedBeijingChina Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijingChina

Purpose-It is of great significance to study the influence of subgrade filling on permafrost temperature field in permafrost area for the smooth construction and safe operation of ***/methodology/approach-The paper builds up the model for the hydrothermal coupling calculation of permafrost using finite element software COMSOL to study how permafrost temperature field changes in the short term after subgrade filling,on which basis it proposes the method of calculation for the concave distortion of freezing front in the subgrade-covered ***-The results show that the freezing front below the subgrade center sinks due to the thermal effect of subgrade filling,which will trigger hydrothermal erosion in case of sufficient moisture inflows,leading to the thawing settlement or the cracking of the subgrade,*** heat output of soil will be hindered the most in case of July filling,in which case the sinking and the distortion of the freezing front is found to be the most severe,which the recovery of the permafrost temperature field,the slowest,constituting the most unfavorable working *** concave distortion of the freezing front in the subgrade area increases with the increase in temperature difference between the filler and ground surface,the subgrade height,the subgrade width and the volumetric thermal capacity of filler,while decreases with the increase of the thermal conductivity of ***,the filler chose for engineering project shall be of small volumetric thermal capacity,low initial temperature and high thermal conductivity whenever ***/value-The concave distortion of the freezing front under different working conditions at different times after filling can be calculated using the method proposed.

关键词： Subgrade Permafrost Temperature field Hydrothermal coupling Numerical simulation