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Time-dependent behavior and permeability evolution of limestone under hydro-mechanical coupling

Journal of Mountain Science 2024年第5期21卷 1697-1714页

作者： WANG Zhilong ZENG Zhengqiang lyu cheng WANG Mingnian HU Xiongyu DONG Yucang School of Civil Engineering Southwest Jiaotong UniversityChengdu 61003China College of Civil Engineering Tongji UniversityShanghai 200092China College of Water Resource and Hydropower Sichuan UniversityChengdu 610065China Hebei GEO University Shijiazhuang 050031China

Excessively high pore water pressure presents unpredictable risks to the safety of rock tunnels in mountainous regions that are predominantly composed of limestone. Investigating the creep characteristics and permeability evolution of limestone under varying hydrated conditions is crucial for a better understanding of the delayed deformation mechanisms of limestone rock tunnels. To this end, this paper initially conducts a series of multi-stage triaxial creep tests on limestone samples under varying pore water pressures. The experiment examines how pore water pressure affects limestone’s creep strain, strain rate, long-term strength, lifespan, and permeability, all within the context of hydraulicmechanical(HM) coupling. To better describe the creep behavior associated with pore water pressure, this paper proposes a new nonlinear fractional creep constitutive model. This constitutive model depicts the initial, steady-state, and accelerated phases of limestone’s creep behavior. Finally, the proposed model is applied to the numerical realization of deformation in limestone tunnel, validating the effectiveness of the proposed constitutive model in predicting tunnel’s creep deformation. This research enhances our understanding of limestone’s creep characteristics and permeability evolution under HM coupling, laying a foundation for assessing the longterm stability of mountain tunnels.

关键词： Creep test Hydraulic-mechanical coupling Creep constitutive model Fractional derivatives Pore pressure

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Preoperative systemic inflammatory response index as a prognostic marker for distal cholangiocarcinoma after pancreatoduodenectomy

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World Journal of Gastrointestinal Surgery 2024年第9期16卷 2910-2924页

作者： Wen-Hui Zhang Yu Zhao cheng-Run Zhang Jin-Can Huang Shao-cheng lyu Ren Lang Department of Hepatobiliary Surgery Beijing Chao-Yang Hospital Affiliated to Capital Medical UniversityBeijing 100020China Department of Urology Surgery Beijing Chao-Yang Hospital Affiliated to Capital Medical UniversityBeijing 100020China

BACKGROUND The relationship between preoperative inflammation status and tumorigenesis as well as tumor progression is widely *** To assess the prognostic significance of preoperative inflammatory biomarkers in patients with distal cholangiocarcinoma(dCCA)who underwent pancreat-oduodenectomy(PD).METHODS This single-center study included 216 patients with dCCA after PD between January 1,2011,and December 31,*** individuals were categorized into two sets based on their systemic inflammatory response index(SIRI)levels:A low SIRI group(SIRI<1.5,n=123)and a high SIRI group(SIRI≥1.5,n=93).Inflam-matory biomarkers were evaluated for predictive accuracy using receiver operating characteristic *** univariate and multivariate Cox proportional hazards analyses were performed to estimate SIRI for overall survival(OS)and recurrence-free survival(RFS).RESULTS The study included a total of 216 patients,with 58.3%being male and a mean age of 65.6±9.6 years.123 patients were in the low SIRI group and 93 were in the high SIRI group after PD for *** had an area under the curve value of 0.674 for diagnosing dCCA,showing better performance than other inflammatory *** analysis indicated that having a SIRI greater than 1.5 independently increased the risk of dCCA following PD,leading to lower OS[hazard ratios(HR)=1.868,P=0.006]and RFS(HR=0.949,P<0.001).Additionally,survival analysis indicated a significantly better prognosis for patients in the low SIRI group(P<0.001).CONCLUSION It is determined that a high SIRI before surgery is a significant risk factor for dCCA after PD.

关键词： Distal cholangiocarcinoma Pancreatoduodenectomy Biomarker Systemic inflammatory response index Prognosis

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基于FLUENT的船用铝合金板激光焊接数值仿真分析

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计算机辅助工程 2024年第3期33卷 7-12页

作者：吕成沪东中华造船集团有限公司上海200129

为得到最佳激光焊接工艺参数,以船用铝合金板为研究对象,利用FLUENT软件建立焊接温度场与流场模型进行仿真分析,按照实际的力和边界条件进行加载,得到不同激光焊接速度下的熔池形貌和温度、速度分布云图。结果表明,在焊接工况一定的条件... 详细信息

为得到最佳激光焊接工艺参数,以船用铝合金板为研究对象,利用FLUENT软件建立焊接温度场与流场模型进行仿真分析,按照实际的力和边界条件进行加载,得到不同激光焊接速度下的熔池形貌和温度、速度分布云图。结果表明,在焊接工况一定的条件下,激光焊接速度对熔池形貌和温度场产生重要影响:焊接速度较快时,金属流体流动不均衡,温度场分布紊乱,熔池形貌复杂且不稳定;焊接速度较慢时,熔池出现大梯度温度分布,金属流体流动较弱;选择合适的焊接速度才能得到较优的产品。

关键词：激光焊接熔池焊接速度温度场流场铝合金

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某三甲医院分离的耐碳青霉烯类肠杆菌目细菌的耐药基因及其同源性

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中华医院感染学杂志 2024年第1期34卷 7-12页

作者：吕岩吕承秀李庆孙晓琳淄博市第一医院检验科山东淄博255200

目的对某三甲医院分离的耐碳青霉烯肠杆菌目细菌(CRE)的耐药表型和耐药基因进行检测,并对其进行同源性分析,探讨产生耐药性的原因,为控制院内传播感染提供理论依据。方法收集2019年1月-2021年9月淄博市第一医院临床标本分离的鉴定为CRE... 详细信息

目的对某三甲医院分离的耐碳青霉烯肠杆菌目细菌(CRE)的耐药表型和耐药基因进行检测,并对其进行同源性分析,探讨产生耐药性的原因,为控制院内传播感染提供理论依据。方法收集2019年1月-2021年9月淄博市第一医院临床标本分离的鉴定为CRE的菌株,通过改良碳青霉烯灭活试验(mCIM)和EDTA改良碳青霉烯灭活试验(eCIM)对CRE菌株进行耐碳青霉烯表型筛选,采用聚合酶链反应(PCR)法对菌株进行耐碳青霉烯相关耐药基因的检测并通过接合实验研究耐药基因的传播能力,多位点序列分型(MLST)分析菌株的同源性关系。结果CRE菌株中,大肠埃希菌54株,肺炎克雷伯菌15株;耐碳青霉烯大肠埃希菌bla_(NDM-1)阳性38株、bla_(OXA-23)阳性9株、bla_(DXA-48)阳性7株,耐碳青霉烯肺炎克雷伯菌bla_(KPC-gp)阳性3株、bla_(KPC-qc)阳性3株、bla_(OXA-48)阳性9株;接合实验结果证实bla_(NDM-1)和bla_(KPC-gp)可以通过接合实验进行传播;大肠埃希菌的ST类型为ST10、ST23、ST131、ST117型,聚类分析发现其分属于不同的克隆群;肺炎克雷伯菌的ST类型为ST11、ST23和ST342型,聚类分析发现其分属于不同的克隆群。结论本地区CRE菌株中,bla_(NDM-1)是导致大肠埃希菌耐药的主要基因,bla_(OXA-48)是导致肺炎克雷伯菌耐药主要基因;MLST分型聚类分析发现碳青霉烯类抗菌药物耐药的大肠埃希菌和肺炎克雷伯菌存在多个克隆复合群的克隆性传播,医院应加强院感防控和监测。

关键词：耐碳青霉烯的肠杆菌目耐药基因接合实验多位点序列分析同源性分析

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数字法学教育的范式转型、规范构建与技术路径

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河北法律职业教育 2024年第6期2卷 4-18页

作者：吕铖钢姚琳浙江工商大学法学院

数字化的浪潮已经席卷了整个中国,面对整个社会的数字化转型,法学教育也迎来了理论知识重组、教学方式更新、培养模式更迭等全新挑战。世异时移,传统的法学教育模式难以匹配数字社会对法治人才培养的要求,数字法学面向的革新已为大势所... 详细信息

数字化的浪潮已经席卷了整个中国,面对整个社会的数字化转型,法学教育也迎来了理论知识重组、教学方式更新、培养模式更迭等全新挑战。世异时移,传统的法学教育模式难以匹配数字社会对法治人才培养的要求,数字法学面向的革新已为大势所趋。在数字技术的推动下,数字法学教育正处于范式转型与规范构建的重要阶段,亟须推进有关数字法学教育的理论研究,对数字法学教育进行价值重塑、体系重建与内容重构,明确数字法学教育发展的技术路径,以适应不断发展的数字化实践,为数字法学教育的发展注入新动力,为数智人才的培养增添新动能。

关键词：数字法学教育数字法学法学教育数字技术虚拟实践教学平台

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Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

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Frontiers of Structural and Civil Engineering 2021年第6期15卷 1480-1493页

作者： Zhengqiang ZENG Shengzhi WU cheng lyu State Key Laboratory of Disaster Reduction in Civil Engineering College of Civil EngineeringTongji UniversityShanghai 200092China School of Civil Engineering Shandong Jianzhu UniversityJinan 250000China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

In waterfront geotechnical engineering,seismic and drainage conditions must be considered in the design of retaining *** paper proposes a general analytical method to evaluate the seismic active earth pressure on a retaining wall with backfill subjected to partial steady seepage flow under seismic *** method comprises the following steps:i)determination of the total head,ii)upper bound solution of seismic active earth thrust,and iii)deduction for the earth pressure *** determination of total head h(x,z)relies on the Fourier series expansions,and the expressions of the seismic active earth thrust and pressure are derived by using the upper bound *** studies reveal that insufficient drainage and earthquakes are crucial factors that cause unfavorable earth *** numerical results confirm the validity of the total head *** indicate that the proposed method is consistent with other relevant existing methods in terms of predicting seismic active earth *** method can be applied to the seismic design of waterfront retaining walls.

关键词： seismic active earth pressure partial seepage flow pore pressure anisotropy upper bound theorem

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Mapping Spatial Distribution Characteristics of Lineaments Extracted from Remote Sensing Image Using Fractal and Multifractal Models

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Journal of Earth Science 2017年第3期28卷 507-515页

作者： cheng lyu Qiuming cheng Renguang Zuo Xueping Wang State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China Faculty of Earth Resources China University of Geosciences Wuhan 430074China

Mapping mineral prospectivity in vegetated areas is a challenge. For this reason, we aimed to map spatial distribution characteristics of linear structures detected in remote sensing images using fractal and multifractal models. The selected study area was the Pinghe District of the Fujian Province（China）, located in the Shanghang-Yunxiao polymetallic and alunite ore belt（within the Wuyishan polymetallic belt）, where mineral resources such as copper, molybdenum, gold, silver, iron, lead, zinc, alunite and pyrophyllite have been discovered. The results of our study showed that：（1） the values of fractal dimension for all lineaments, NW-trending lineaments, and NE-trending lineaments, are 1.36, 1.32, and 1.23, respectively, indicating that these lineaments are statistically self-similar;（2） the fractal dimensions of the spatial distribution of the linear structures in the four selected hydrothermal-type ore deposits of the Pinghe District, named Zhongteng, Panchi, Xiaofanshan and Fanshan, are 1.43, 1.52, 1.37 and 1.37, respectively, which are higher than the mean value in South China;（3） the spatial distribution of the linear structures extracted from the remote sensing image and displayed by the contour map of fractal dimensions, correlates well with the known hydrothermal ore deposits; and（4） the results of the anomaly map decomposed by the spectrum-area（S-A） multifractal model is much better than the original fractal dimension contour map, which showed most of the known hydrothermal-type deposits occur in the high anomalous area. It is suggested that a high step tendency possibly matches with the boundary of the volcanic edifice and the deep fault controlling the development of the rock mass and the volcanic edifice. The complexity of the spatial distribution of mapped lineations（faults） in the Pinghe District, characterized by high values in the anomaly map, may be associated with the hydrothermal polymetallic ore mineralization in the study area.

关键词： fractal model ETM+ data vegetation coverage area Pinghe molybdenum deposit

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Lateral Vibration Behavior Analysis and TLD Vibration Absorption Design of the Soft Yoke Single-Point Mooring System

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China Ocean Engineering 2017年第3期31卷 284-290页

作者： lyu Bai-cheng WU Wen-hua YAO Wei-an DU Yu State Key Laboratory of Structural analysis for Industrial Equipment Dalian University of Technology Dalian 116023 China

Mooring system is the key equipment of FPSO safe operation. The soft yoke mooring system is regarded as one of the best shallow water mooring strategies and widely applied to the oil exploitation in the Bohai Bay in China and the Gulf of Mexico. Based on the analysis of numerous monitoring data obtained by the prototype monitoring system of one FPSO in the Bohai Bay, the on-site lateral vibration behaviors found on the site of the soft yoke subject to wave load were analyzed. ADAMS simulation and model experiment were utilized to analyze the soft yoke lateral vibration and it was determined that lateral vibration was resonance behaviors caused by wave excitation. On the basis of the soft yoke longitudinal restoring force being guaranteed, a TLD-based vibration damper system was constructed and the vibration reduction experiments with multi-tank space and multi-load conditions were developed. The experimental results demonstrated that the proposed TLD vibration reduction system can effectively reduce lateral vibration of soft yoke structures.

关键词： FPSO soft yoke mooring system vibration absorption TLD prototype monitoring system Bohai Bay

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微波消解-电感耦合等离子体质谱(ICP-MS)法测定黑土地地表基质调查样品中碘

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中国无机分析化学 2024年第7期14卷 980-985页

作者：谢旭卢兵赵文志吕程何添张元韩晨灏中国地质调查局哈尔滨自然资源综合调查中心哈尔滨150086

碘是活跃元素,价态多,各价态间易相互转化,使其具有熔点低、易挥发,严重记忆效应的独特性质,其分析一直是个挑战。传统方法如半熔法、高压密闭法等存在操作难度大、消解时间长、工作效率低等问题。通过采用硝酸-氢氟酸微波消解处理样品... 详细信息

碘是活跃元素,价态多,各价态间易相互转化,使其具有熔点低、易挥发,严重记忆效应的独特性质,其分析一直是个挑战。传统方法如半熔法、高压密闭法等存在操作难度大、消解时间长、工作效率低等问题。通过采用硝酸-氢氟酸微波消解处理样品,并利用电感耦合等离子体质谱(ICP-MS)法测定碘含量,克服了传统碘分析方法的一系列问题。研究了不同酸体系和赶酸时间对样品分解效率和挥发损失的影响,同时验证了不同冲洗液对降低碘记忆效应的效果。在此基础上,确定了最佳反应条件为7 mL硝酸+1 mL氢氟酸混合酸比例,180℃赶酸控温程序,并采用2%NH_(3)·H_(2)O充当冲洗液,降低了ICP-MS测定过程中的记忆效应,提高测试的稳定性。为验证该使用国家一级标准物质对方法的准确性和精密度进行验证,结果表明,方法的准确度(Δlgc)为0.001~0.004,相对标准偏差(RSD)为1.2%~3.4%,相关系数为0.9998,检出限为0.17 mg/kg,定量限为0.54 mg/kg,表现出较好的准确度和精密度,满足规范要求。通过实际样品测试,进一步验证了方法的可行性,实验结果表明,相对偏差在1.6%~4.1%。方法操作方便、试剂用量少、工作效率高,适用于测定黑土地地表基质调查样品,同时也为碘的快速、准确分析提供了一种可行的解决方案。

关键词：微波消解电感耦合等离子体质谱法黑土地地表基质调查样品碘

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急性高原病的中西医非药物预防策略研究进展

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中华危重病急救医学 2024年第6期36卷 669-672页

作者：李丽卢佩佩曹志文温博沈珊珊王子荣谭勇吕诚中国中医科学院中医临床基础医学研究所北京100700 北京市门头沟区中医医院脑病科北京102300 国家移民管理局后勤保障处北京100741

急性高原病(AHAD)是对高原低压缺氧环境适应不良出现的一系列临床反应的总称,轻者会发生头痛、恶心呕吐,重者则会出现肺水肿、脑水肿等危重情况,对人体造成致命性威胁。随着进入高原需求的增加,了解AHAD的常见预防措施可在一定程度上降... 详细信息

急性高原病(AHAD)是对高原低压缺氧环境适应不良出现的一系列临床反应的总称,轻者会发生头痛、恶心呕吐,重者则会出现肺水肿、脑水肿等危重情况,对人体造成致命性威胁。随着进入高原需求的增加,了解AHAD的常见预防措施可在一定程度上降低其发病率或致死率,对短期内旅居高原者大有裨益。近年来,人们的健康保健意识提高,对非药物预防疾病的关注度增加,同时非药物疗法防治高原病的疗效显著,引起了该领域研究人员的重视。本文撷取现代医学非药物预防策略,并着重从中医学角度出发,概括当前应对AHAD的非药物防治方法,以期服务于临床,降低AHAD的发病率,并改善预后。

关键词：急性高原病现代医学中医学预防策略非药物

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