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淬火工艺对28MnCrMoRE油井管钢显微组织及硬度的影响

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金属热处理 2024年第8期49卷 160-165页

作者：孙昭琦李涛韩强张行刚白岩松高志敏内蒙古科技大学材料与冶金学院内蒙古包头014010 内蒙古包钢钢联股份有限公司内蒙古包头014010

以28MnCrMoRE钢油井管钢为研究对象,探究淬火工艺对深井油井管显微组织及硬度的影响。采用金相显微镜对淬火后原奥氏体晶粒进行观察,通过Image-ProPlus软件对原始奥氏体晶粒度进行统计;利用扫描电镜对淬火后的微观组织进行了观察及分析... 详细信息

以28MnCrMoRE钢油井管钢为研究对象,探究淬火工艺对深井油井管显微组织及硬度的影响。采用金相显微镜对淬火后原奥氏体晶粒进行观察,通过Image-ProPlus软件对原始奥氏体晶粒度进行统计;利用扫描电镜对淬火后的微观组织进行了观察及分析;利用洛氏硬度计进行硬度测试。结果表明,28MnCrMoRE钢分别经870、900、930℃保温30 min水淬后,原始奥氏体晶粒平均尺寸随淬火温度上升由8.21μm增大到12.67μm。当淬火温度为900℃,试验钢在保温90 min时原始奥氏体晶粒发生明显的异常长大;保温30 min时,原始奥氏体晶粒相对细小均匀且尺寸符合正态分布。28MnCrMoRE钢淬火组织为马氏体+贝氏体+残留奥氏体。随着淬火温度的升高或保温时间的延长,马氏体含量逐渐减少,组织有一定的粗化,试验钢的硬度先上升后下降,最大值为53.02 HRC。

关键词： 28MnCrMoRE钢油井管淬火工艺显微组织硬度

Geomechanics involved in gas hydrate recovery

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Chinese Journal of Chemical Engineering 2019年第9期27卷 2099-2106页

作者： Zhiqiang Liu Yunxiao Lu Jiuhui Cheng qiang han Zunjing Hu Linlin Wang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum-BeijingBeijing 102249China College of Petroleum Engineering China University of Petroleum-BeijingBeijing 102249China Downhole Service Company of Sinopec Shengli Oilfield Service Corporation China

Gas hydrate is regarded as a promising energy owing to the large carbon reserve and high energy ***,due to the particularity of the formation and the complexity of exploitation process,the commercial exploitation of gas hydrate has not been *** paper reviews the physical properties of gas hydratebearing sediments and focuses on the geomechanical response during the *** exploitation of gas hydrate is a strong thermal–hydrological–mechanical–chemical(THMC)coupling process:decomposition of hydrate into water and gas produces multi-physical processes including heat transfer,multi-fluid flow and deformation in the *** physical processes lead to a potential of geomechanical issues during the production *** occurrence of sand production is the major limitation of the commercial exploitation of gas *** potential landslide and subsidence will lead to the cessation of the production and even serious *** researches have been conducted to investigate the geomechanical properties of gas hydrate-bearing sediments and to assess the wellbore integrity during the *** physical properties of hydrate have been fully studied,and some models have been established to describe the physical processes during the exploitation of gas *** the reproduction of actual conditions of hydrate reservoir in the laboratory is still a huge challenge,which will inevitably lead to a bias of *** addition,because of the effect of microscopic mechanisms in porous media,the coupling mechanism of the existing models should be further *** efforts,however,are still required for a comprehensive understanding of this strong coupling process that is extremely different from the geomechanics involved in the conventional reservoirs.

关键词： Gas hydrate Phase transition THMC coupling Wellbore integrity Sand production

Seismic damage of highway bridges during the 2008 Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2009年第2期8卷 263-273页

作者： han qiang Du Xiuli Liu Jingbo Li Zhongxian Li Liyun Zhao Jianfeng Lab. of Urban Security ＆ Dixaster Engineering of MOE Beijing University of Technology Beijing 100124 China Key Department of Civil Engineering Tsinghua University Belling 100084 China College of Civil Engineering Tianjin University Tianjin 200072 China College of Civil Engineering Qingdao Technological University Qingdao 266033 China

Many highway bridges were severely damaged or completely collapsed during the 2008 Wenchuan earthquake. A field investigation was carried out in the strongly affected areas and over 320 bridges were examined. Damage to some representative highway bridges is briefly described and a preliminary analysis of the probable causes of the damage is presented in this paper. The most common damage included shear-flexural failure of the pier columns, expansion joint failure, shear key failure, and girder sliding in the transversal or longitudinal directions due to weak connections between girder and bearings. Lessons learned from this earthquake are described and recommendations related to the design of curved and skewed bridges, design of bearings and devices to prevent girder collapse, and ductility of bridge piers are presented. Suggestions for future seismic design and retrofitting techniques for bridges in moderate to severe earthquake areas are also proposed.

关键词： Wenchuan earthquake seismic damage seismic design highway bridge field investigation

An Azoester-containing Photoresponsive Linear Liquid Crystal Polymer with Good Mesophase Stability

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Chinese Journal of Polymer Science 2020年第8期38卷 806-813,I0005页

作者： Shu-qiang han Ying-Ying Chen Bo Xu Jia Wei Yan-Lei Yu Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers Fudan UniversityShanghai200433China

Photoresponsive linear liquid crystal polymers(LLCPs)are attractive because of the excellent stimuli-responsibility and the good *** this study,a new photoresponsive LLCP containing azoester(PC11AE6)with good mesophase stability was synthesized by ringopening metathesis *** introducing photoresponsive azoester mesogenic unit,which has high rigidity and a large lengthdiameter ratio,the resultant polymer possesses a broad mesophase temperature interval(isotropic temperature=180℃).A study on mesophase by 2D-wide angle X-ray diffraction indicated that the mesogens were orientated spontaneously into smectic A phase after *** orientated films and fibres exhibited macroscopic,rapid and reversible deformations under light irradiation as a result of the photoisomerization of azoester as confirmed by UV-Vis absorption *** anticipate that this work provides a strategy for preparing LLCP with a broad mesophase temperature range,which is positive for potential applications.

关键词： Ring-opening metathesis polymerization Liquid crystal polymers Azoester Photodeformation

中医药治疗良性前列腺增生随机对照试验的方法学质量与文献报告质量评价

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中华男科学杂志 2024年第2期30卷 167-173页

作者：王任远唐新越韩强曾银王和天郭军首都医科大学附属北京中医医院男科首都医科大学附属北京中医医院肾病科中国中医科学院西苑医院男科

目的:系统评价中医药治疗BPH随机对照试验(RCT)的方法学质量与文献报告质量，以期为今后的临床实践和研究提供方法学参考。方法:检索中国知网(CNKI)、维普网(VIP)、万方数据(WF)、PubMed中自2013年1月以来至2023年11月公开发表的关于中... 详细信息

目的:系统评价中医药治疗BPH随机对照试验(RCT)的方法学质量与文献报告质量，以期为今后的临床实践和研究提供方法学参考。方法:检索中国知网(CNKI)、维普网(VIP)、万方数据(WF)、PubMed中自2013年1月以来至2023年11月公开发表的关于中医药治疗BPH的RCT,2名研究者单独筛选文献，以Cochrane偏倚风险评估工具和CONSORT-中药复方为依据，评价纳入RCT的方法学质量和报告质量。结果:纳入88篇RCT,方法学质量方面，根据Cochrane偏倚风险评估工具评价：随机化过程中的偏倚27篇为低风险，61篇存在一定风险；偏离既定干预措施的偏倚(干预措施分配的效果)中76篇为低风险，10篇存在一定风险，2篇高风险；偏离既定干预措施的偏倚(干预措施依从的效果)中76篇为低风险，12篇存在一定风险；结局数据缺失的偏倚中86篇为低风险，2篇存在一定风险；结局测量的偏倚中全部文献为低风险；选择性报告结果的偏倚中65篇为低风险，2篇存在一定风险，21篇为高风险。报告质量方面，根据CONSORT-中药复方的评价标准：1篇(0.01%)采用了适当的关键词，27篇(30.68%)描述了随机分配序列方法，5篇(5.68%)对分配限定细节进行了描述，3篇(3.41%)提及分配隐藏，3篇(3.41%)实施了盲法及分配隐藏，10篇(11.36%)记录了脱落情况，38篇(43.18%)报道了不良事件，18篇(20.45%)分析了试验局限性；所有文献均无完整的干预措施、无受试者流程图、无临床试验注册及研究方案。结论:目前国内有关中医药治疗BPH的RCT的方法学质量与文献报告质量普遍偏低，问题集中在实验设计不完整，缺乏随机与盲法的详细描述，结局指标缺少中医症候评价等方面。在采纳和运用其结果时应谨慎；研究者应遵循CONSORT声明进行方案设计、注册、实施及报告，充分考虑中医药治疗BPH的临床特点，合理设计和报告评价指标。

关键词：良性前列腺增生中医药随机对照试验质量评价

两样本孟德尔随机化分析炎性因子与前列腺癌因果关系

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中华男科学杂志 2024年第7期30卷 588-596页

作者：曾银张甘霖郭军杨梦萍韩强杨国旺首都医科大学附属北京中医医院北京100010 中国中医科学院西苑医院男科北京100091 北京中医药大学第三临床医学院北京100029

目的:采用两样本孟德尔随机化方法来评估91种炎性因子与前列腺癌的潜在因果关系。方法:选取91种炎性因子的全基因组关联分析(GWAS)汇总统计数据(n=14824)结合FinnGen最新第9版数据库中选取前列腺癌作为结局进行孟德尔随机化分析。通过... 详细信息

目的:采用两样本孟德尔随机化方法来评估91种炎性因子与前列腺癌的潜在因果关系。方法:选取91种炎性因子的全基因组关联分析(GWAS)汇总统计数据(n=14824)结合FinnGen最新第9版数据库中选取前列腺癌作为结局进行孟德尔随机化分析。通过逆方差加权法(IVW)、MR-Egger回归、简单中位数法(SM)、加权中位数法(WM)、加权中值法(WME)等回归模型的OR值和95%CI评估炎性因子与前列腺癌的因果关系,其中IVW法得出的因果关系相对稳定,作为本研究的主要统计方法。进一步采用贝叶斯分析法对孟德尔分析结果进行验证。使用Cochran's Q检验评估遗传工具变量的异质性,使用MR-Egger截距检验评估多效性,使用留一法评估作为工具变量的单核苷酸多态性(SNPs)对暴露和结局因果关系影响的敏感性。结果:IVW法结果显示,91种炎性因子中白介素-22受体A1(IL-22RA1)、磺基转移酶1A1(ST1A1)与前列腺癌发病风险呈正向因果关联:IL-22RA1:IVW[OR(95%CI):1.12(1.00~1.25),P=0.04];ST1A1:IVW[OR(95%CI):1.08(1.00~1.16),P=0.03]。趋化因子配体11(CXCL11)、白介素17A(IL-17A)与前列腺癌发病风险呈反向因果关联;CXCL11:IVW[OR(95%CI):0.88(0.81~0.95),P=0.00];IL-17A:IVW[OR(95%CI):0.91(0.84~0.98),P=0.02]。MR-Egger截距分析未检测到潜在的水平多效性(P均>0.05,IL-22RA1=0.885,ST1A1=0.949,CXCL11=0.391,IL-17A=0.884)。MR-PRESSO未检测到偏倚SNPs(P均>0.05,IL-22RA1=0.479,ST1A1=0.629,CXCL11=0.326,IL-17A=0.444),未发现异质性(P均>0.05,IL-22RA1=0.543,ST1A1=0.677,CXCL11=0.336,IL-17A=0.494),留一法敏感性分析结果图提示无个别单核苷酸多态性位点对整体因果关系预测产生明显影响,故分析结果可靠。结论:91种炎性因子中IL-22RA1、ST1A1与前列腺癌有正向因果关系,随着这些因子的水平增加,前列腺癌发病的风险升高;CXCL11、IL-17A与前列腺癌有反向因果关系,即随着这些因子的水平增加,前列腺癌发病风险降低。

关键词：炎性因子前列腺癌孟德尔随机化分析敏感性分析单核苷酸多态性贝叶斯分析

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张家峁矿近水体煤层群隔水煤柱合理宽度确定

西安科技大学学报 2024年第2期44卷 256-267页

作者：呼少平胡俭姬中奎杨帆王海贺晓忠韩强薛小渊陈盼东北大学冶金学院辽宁沈阳110819 陕煤神木张家峁矿业公司陕西神木719316 中煤科工西安研究院(集团)有限公司陕西西安710077

针对张家峁常家沟水库近水体煤层开采后覆岩裂隙扩展诱发透水的潜在风险,对煤层开采过程中的覆岩破坏特征及裂隙扩展规律进行了模型试验及数值模拟研究。为合理确定4^(-2)煤层的隔水煤柱宽度,基于矿山支承压力和静水压力对隔水煤柱的不... 详细信息

针对张家峁常家沟水库近水体煤层开采后覆岩裂隙扩展诱发透水的潜在风险,对煤层开采过程中的覆岩破坏特征及裂隙扩展规律进行了模型试验及数值模拟研究。为合理确定4^(-2)煤层的隔水煤柱宽度,基于矿山支承压力和静水压力对隔水煤柱的不同作用机理,将4^(-2)煤层隔水煤柱划分为矿压影响区和有效隔水区,分别构建了矿压影响区和有效隔水区的煤柱受力分析计算模型,推导了4^(-2)煤层矿压影响区和有效隔水区的理论宽度计算公式。在此基础上,考虑煤层开采边界角与水体下伏不同煤层矿压影响区宽度的关系,提出了“上覆煤柱宽度+矿压影响区”的水体下伏煤层群隔水煤柱宽度确定方法。结果表明:4^(-2)煤层工作面初次来压步距为45~56 m,周期来压步距为13.8~14.9 m,上覆岩层冒落带高度为12~13 m;地表最大下沉量为2.0~2.2 m,下沉系数为0.571~0.629,4^(-2)、4^(-3)、4^(-4)和5^(-2)煤层隔水煤柱的合理宽度分别为25,39,51和87 m。现场实测隔水效果验证了近水体煤柱理论留设宽度的合理性及其工程适用性,为张家峁近水体煤层群安全高效开采提供了技术保障。

关键词：近水体煤层群覆岩破坏隔水煤柱矿压影响区有效隔水区合理宽度

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Investigations on the degradation of aspartame using high-performance liquid chromatography/tandem mass spectrometry

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Chinese Chemical Letters 2014年第9期25卷 1259-1264页

作者： Jie-Ping Sun qiang han Xiao-Qiong Zhang Ming-Yu Ding Beijing Key Laboratory for Microanalytical Methods and Instrumentation Department of ChemistryTsinghua University

Aspartame is a widely used sweetener, the long-term safety of which has been controversial ever since it was accepted for human consumption. It is unstable and can produce some harmful degradation products under certain storage conditions. A high-performance liquid chromatography/tandem mass spectrometry method was developed for the simultaneous analysis of aspartame and its four degradation products, including aspartic acid, phenylalanine, aspartyl-phenylalanine and 5-benzyl-3,6- dioxo-2-piperazieacetic acid in water and in diet soft drinks. Aspartame and its four degradation products were quantified by a matrix matched external standard calibration curve with excellent correlation coefficients. The limits of detection were 0.16-5.8 μg/L, which exhibited higher sensitivity than common methods. This method was rapid, sensitive, specific and capable of eliminating matrix interferences. It was also applied to the study of the degradation of aspartame at various pH and temperatures. The results indicated that aspartame was partly degraded under strong acidic or basic conditions and the extent of degradation increased with increasing temperature.

关键词： High-performance liquid chromatography/tandem mass spectrometry Aspartame Degradation productsCola

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预制装配墩柱-桩基础承插节点冲切性能研究

市政技术 2024年第10期42卷 106-118页

作者：谢濠君张广达韩强杜修力北京工业大学桥梁工程安全与韧性全国重点实验室北京100124 福州大学土木工程学院福建福州350108

承插连接由于具有整体性能好、施工工序简单和拼装容许误差大等优点,成为预制装配桥墩节点的有效连接方式之一。为探明桩基础承插节点的冲切失效模式及承载力计算方法,采用ABAQUS有限元软件建立预制装配墩柱-桩基础承插节点数值计算模型... 详细信息

承插连接由于具有整体性能好、施工工序简单和拼装容许误差大等优点,成为预制装配桥墩节点的有效连接方式之一。为探明桩基础承插节点的冲切失效模式及承载力计算方法,采用ABAQUS有限元软件建立预制装配墩柱-桩基础承插节点数值计算模型,通过UHPC-NC直剪试验和墩柱-桩基础轴压试验进行了数值模型校验,研究了底板、接缝和承插连接参数对预制装配墩柱-桩基础承插节点的冲切传力机制、承载能力和失效模式的影响规律,提出了预制装配墩柱-桩基础承插节点冲切承载力计算公式。数值模拟结果表明,预制装配墩柱-桩基础承插节点的传力路径沿墩柱底部到桩的顶部;峰值荷载过后,承台底部混凝土开裂失效;接缝承载力和UHPC与混凝土之间的接触面积呈正相关,承台的冲切承载力与底板高度呈正相关。此外,当承插深度与底板高度之比由0.60增大到2.08时,接缝承载力提升了80.2%,而承插连接以及底板承载力分别降低了27.7%、52.9%,承插连接参数与底板参数具有相同的变化趋势,且底板承载力对承插连接承载力的占比较大,说明底板对承插节点承载力的贡献起主导作用。通过对已有试验和数值模拟分析,将底板和接缝的贡献系数分别取为1.00和0.92,为类似预制装配墩柱-桩基础承插节点冲切承载力的计算提供了依据。

关键词：墩柱-桩基础承插节点冲切性能界面黏聚力荷载传递路径承载力分配关系

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