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Quality of life after pancreatic surgery

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World Journal of Gastroenterology 2024年第8期30卷 943-955页

作者： shi-zhen li Ting-Ting zhen Yi Wu Min Wang Ting-Ting Qin Hang Zhang Ren-Yi Qin Department of Biliary-Pancreatic Surgery Affiliated Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030Hubei ProvinceChina

BACKGROUND Pancreatic surgery is challenging owing to the anatomical characteristics of the *** attention has been paid to changes in quality of life(QOL)after pancreatic *** To summarize and analyze current research results on QOL after pancreatic *** A systematic search of the literature available on PubMed and EMBASE was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses *** studies were identified by screening the references of retrieved *** on patients’QOL after pancreatic surgery published after January 1,2012,were *** included prospective and retrospective studies on patients'QOL after several types of pancreatic *** results of these primary studies were summarized *** A total of 45 articles were included in the study,of which 13 were related to pancreaticoduodenectomy(PD),seven to duodenum-preserving pancreatic head resection(DPPHR),nine to distal pancreatectomy(DP),two to central pancre-atectomy(CP),and 14 to total pancreatectomy(TP).Some studies showed that 3-6 months were needed for QOL recovery after PD,whereas others showed that 6-12 months was more *** TP and PD had similar influences on QOL,patients needed longer to recover to preoperative or baseline levels after *** QOL was better after DPPHR than ***,the superiority of the QOL between patients who underwent CP and PD remains *** decrease in exocrine and endocrine functions postoperatively was the main factor affecting the *** invasive surgery could improve patients’QOL in the early Core Tip:This review summarizes and analyzes current research results on quality of life(QOL)after pancreatic *** article covers the discussion and analysis of the QOL of various pancreatic *** kind of surgical procedure has better QOL is *** long-term benefits on QOL of minimally invasive su

关键词： Quality of life Pancreaticoduodenectomy Duodenum-preserving pancreatic head resection Distal pancreatectomy Central pancreatectomy Total pancreatectomy

Geological conditions and reservoir characteristics of various shales in major shalehosted regions of China

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China Geology 2024年第1期7卷 138-149页

作者： Shu-jing Bao Tian-xu Guo Jin-tao Yin Wei-bin liu Sheng-jian Wang Hao-han li Zhi Zhou shi-zhen li Xiang-lin Chen The Key Laboratory of Unconventional Petroleum Geology China Geological SurveyMinistry of Natural Resources100083 BeijingChina Oil and Gas Survey China Geological Survey100083 BeijingChina Research Institute of Yanchang Petroleum(Group)CO.LTD 710076 Xi’anChina

China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional *** types of shale gas are associated with significantly different formation conditions and major controlling *** study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale *** general,shales in China’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas *** strata generally show high degrees of thermal *** contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these *** shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of *** shales are followed by those in the Niutitang and Longtan *** contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low ***,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral *** a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some *** marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production.

关键词： Shale gas Marine shale Continental shale Marine-continental transitional shale Neoproterozoic-Cretaceous strata Geological conditions Reservoir characteristics Petroleum geological survey engineering

Formation,evolution,reconstruction of black shales and their influence on shale oil and gas resource

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China Geology 2024年第3期7卷 551-585页

作者： shi-zhen li Qiu-chen Xu Mu liu Guo-heng liu Yi-fan li Wen-yang Wang Xiao-guang Yang Wei-bin liu Yan-fei An Peng Sun Tao liu Jiang-hui Ding Qian-chao li Chao-gang Fang State Key Laboratory of Continental Shale Oil Beijing 100083China The Key Laboratory of Unconventional Oil and Gas Geology China Geological SurveyBeijing 100083China Oil and Gas Survey China Geological SurveyMinistry of Natural ResourcesBeijing 100083China State Key Laboratory of lithospheric and Environmental Coevolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Geosciences China University of Petroleum(East China)Qingdao 266580China School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Petroleum Resources Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Resource and Environment Engineering Anhui UniversityHefei 230601China Yangtze University Wuhan 430100China Nanjing Center China Geological SurveyNanjing 210016China National Elite Institute of Engineering CNPCBeijing 100096China

Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and *** are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human *** also record the evolution process of the earth and improve the understanding of the *** review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and *** terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional *** formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom *** a geological perspective,the formation of black shales is often closely related to global or regional major geological *** enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation *** terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore *** terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore *** activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black *** resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales wou

关键词： Black shales Shale oil and gas Resource effects Sedimentary environment Sedimentary process Organic matter accumulation Diagenetic evolution Thermal evolution Organic matter and inorganic minerals Tectonic reconstruction Oil and gas exploration engineering Veins Fluid activity

THE OPTIMAL CONVERGENCE ORDER OF THE DISCONTINUOUS FINITE ELEMENT METHODS FOR FIRST ORDER HYPERBOliC SYSTEMS

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Journal of Computational Mathematics 2008年第5期26卷 689-701页

作者： Tie Zhang Datao shi zhen li Department of Mathematics and School of Information Science and Engineering Northeastern University Shenyang 110004 China

In this paper, a discontinuous finite element method for the positive and symmetric, first-order hyperbolic systems （steady and nonsteady state） is constructed and analyzed by using linear triangle elements, and the O（h^2）-order optimal error estimates are derived under the assumption of strongly regular triangulation and the Ha-regularity for the exact solutions. The convergence analysis is based on some superclose estimates of the interpolation approximation. Finally, we discuss the Maxwell equations in a two-dimensional domain, and numerical experiments are given to validate the theoretical results.

关键词： First order hyperbolic systems Discontinuous finite element method Convergence order estimate.

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高寒区冻融环境下岩体爆破漏斗试验研究

爆破 2024年第3期41卷 60-68,110页

作者：刘博苟永刚叶明珠潘懿拾立振长沙矿山研究院有限责任公司长沙410012 湖南省矿山地质灾害防治与环境再造工程技术研究中心长沙410012 河海大学土木与交通学院南京210029 南通河海大学海洋与近海工程研究院南通226000

相比常规岩体,高寒区冻融环境下岩体的力学参数及破碎特征均存在显著变化,其矿岩爆破开挖也难以直接应用传统设计参数,开展冻融环境下的爆破工艺参数研究具有重要意义。研究以巨龙铜矿为依托,在分析冻融循环对岩石力学特性影响的基础上... 详细信息

相比常规岩体,高寒区冻融环境下岩体的力学参数及破碎特征均存在显著变化,其矿岩爆破开挖也难以直接应用传统设计参数,开展冻融环境下的爆破工艺参数研究具有重要意义。研究以巨龙铜矿为依托,在分析冻融循环对岩石力学特性影响的基础上,开展了冻融环境下矿岩的单孔和双孔同段爆破漏斗试验,测定了爆破漏斗几何参数和块度分布,采用拟合方法确定了爆破设计的合理参数,并对比分析了该矿山四种不同岩性条件下的爆破漏斗参数变化。结果表明:冻融循环作用下岩体力学特性显著衰减,单轴抗压强度和弹性模量下降幅度可达40.6%、54.0%;不同岩性条件下冻融矿岩的单孔爆破最佳埋深比为0.678~0.789,最佳药包埋深与漏斗半径比值分布在0.875~1.076范围内。针对知不拉矿区炮孔孔径152 mm,矽卡岩孔网参数为4.5 m×3 m,炸药单耗0.56 kg/m^(3);凝灰岩孔网参数为5 m×4 m,炸药单耗0.63 kg/m^(3);针对巨龙矿区孔径310 mm,凝灰岩爆破孔网参数为7 m×5 m,炸药单耗0.61 kg/m^(3);花岗斑岩孔网参数为8 m×5 m,炸药单耗0.64 kg/m^(3)。

关键词：高寒地区冻融环境岩体爆破爆破设计参数物理力学特性爆破漏斗试验

Effects of Dendritic Orientation on Stress Rupture Properties of DD6 Single Crystal Superalloy

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Journal of Iron and Steel Research International 2011年第10期18卷 66-71页

作者： shi zhen-xue li Jia-rong liU shi-zhong ZHAOJin-qian National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095 China

DD6 single crystal superalloy slabs were prepared with seed method in the direetionally solidified furnace with high temperature gradient. The transverse stress rupture properties and fracture hehaviour of the alloy at 760 ℃/758 MPa, 850 ℃/550 MPa and 980 ℃/250 MPa were investigated and compared with those of longitudinal specimens. The transverse stress rupture lives are corresponding with the longitudinal stress rupture lives at 760 ℃/758 MPa and 850 ℃/550 MPa. The transverse stress rupture lives are slightly less than the longitudinal stress rupture lives at 980 ℃/ 250 MPa. The fracture mechanism of the transverse stress rupture of the alloy at 760 ℃/758 MPa shows quasi-cleav- age mode and the fracture mechanism at 980 ℃/250 MPa shows dimple mode, while the fracture mechanism at 850 ℃/ 550 MPa shows quasi-cleavage and dimple mixture mode. At higher temperature and lower stress, the microeracks are easier to initiate and interconnect in the transverse specimen than those in longitudinal specimen because there are interdendritic regions perpendicular to the axis of stress.

关键词： DD6 single crystal superalloy stress rupture property fracture behaviour

后冬奥时期我国冰雪体育保险的价值意蕴、现实困境与纾解方略

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哈尔滨体育学院学报 2024年第1期42卷 22-28页

作者：吴建曹电康李晓栋时丽珍荆立新中北大学体育学院山西太原030051 西南大学体育学院重庆400715 哈尔滨体育学院体育人文社会学院黑龙江哈尔滨150008

采用文献资料、逻辑分析等研究方法,立足冰雪体育保险,分析其在后冬奥时期的价值意蕴和现实困境,并提出纾解方略。研究认为:后冬奥时期发展冰雪体育保险可以拓宽保障范围,完善体育保险市场体系;繁荣冰雪经济,推动冰雪体育产业高质量发展... 详细信息

采用文献资料、逻辑分析等研究方法,立足冰雪体育保险,分析其在后冬奥时期的价值意蕴和现实困境,并提出纾解方略。研究认为:后冬奥时期发展冰雪体育保险可以拓宽保障范围,完善体育保险市场体系;繁荣冰雪经济,推动冰雪体育产业高质量发展;巩固冬奥成果,保障“带动三亿人参与冰雪运动”可持续发展。冰雪体育保险发展面临的现实困境:体育保险法律体系不完善;冰雪体育参与者保险意识淡薄;冰雪体育保险中介市场发展缓慢;冰雪体育保险产品单一,保险数据匮乏;冰雪体育保险专业人才短缺等。纾解方略:制度推进,完善体育保险法律法规体系;宣传引领,提升国民冰雪体育保险意识;企业为先,夯实冰雪体育保险中介市场;创新导向,丰富冰雪体育保险产品供给;人才保障,培育冰雪体育保险专业人才。以期为冰雪运动提供良好的支持和保障,为冰雪体育产业高质量发展保驾护航。

关键词：后冬奥时期冰雪运动体育保险冰雪体育保险

An anti-collision algorithm for robotic search-and-rescue tasks in unknown dynamic environments

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 569-584页

作者： Yang CHEN Dianxi shi Huanhuan YANG Tongyue li zhen WANG School of Computer Science Peking UniversityBeijing 100871China Tianjin Artificial Intelligence Innovation Center Tianjin 300457China Intelligent Game and Decision Lab Beijing 100071China College of Computer National University of Defense TechnologyChangsha 410073China

This paper deals with the search-and-rescue tasks of a mobile robot with multiple interesting targets in an unknown dynamic *** problem is challenging because the mobile robot needs to search for multiple targets while avoiding obstacles *** ensure that the mobile robot avoids obstacles properly,we propose a mixed-strategy Nash equilibrium based Dyna-Q(MNDQ)***,a multi-objective layered structure is introduced to simplify the representation of multiple objectives and reduce computational *** structure divides the overall task into subtasks,including searching for targets and avoiding ***,a risk-monitoring mechanism is proposed based on the relative positions of dynamic *** mechanism helps the robot avoid potential collisions and unnecessary ***,to improve sampling efficiency,MNDQ is presented,which combines Dyna-Q and mixed-strategy Nash *** using mixed-strategy Nash equilibrium,the agent makes decisions in the form of probabilities,maximizing the expected rewards and improving the overall performance of the Dyna-Q ***,a series of simulations are conducted to verify the effectiveness of the proposed *** results show that MNDQ performs well and exhibits robustness,providing a competitive solution for future autonomous robot navigation tasks.

关键词： Search and rescue Reinforcement learning Game theory Collision avoidance Decision-making

A Novel Gymnosperm Wood from the Lopingian(Late Permian)in Zhangzi,Shanxi,North China and Its Paleoecological and Paleogeographic Implications

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Journal of Earth Science 2024年第1期35卷 167-176页

作者： Xiao shi Jianxin Yu Yuewu Sun zhen Xu Hui li College of Earth Sciences Jilin UniversityChangchun 130061China International Center of Future Science Dinosaur Evolution Research CenterJilin UniversityChangchun 130012China State Key Laboratory of Biogeology and Environmental Geology School of Earth SciencesChina University of GeosciencesWuhan 430074China Research Center of Palaeontology and Stratigraphy Jilin UniversityChangchun 130026China Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation East China University of TechnologyNanchang 330013China

The Permian-Triassic transition saw extreme climatic changes that severely impacted the terrestrial *** plants,particularly fossil woods,are sensitive to climatic changes,and they,therefore,are unique materials revealing extreme environmental and climatic changes on land at that *** conifer woods were discovered in the Lopingian(Late Permian)strata of the Sunjiagou Formation in Shanxi Province,North *** newly finding permineralized woods record the unique landscape of Lopingian North *** represent a new conifer genus and species:Shanxiopitys zhangziensis *** *** of growth pattern and anatomical characteristics of the fossil woods indicate these trees grew under optimal growing conditions,and without seasonal growth ***,climate signals from leaf fossils,vertebrate fossils and sedimentary evidences indicate a strongly seasonal climate in North China during the ***,it is speculated that these trees likely lived in the gallery forests,which were distributed along the paleo-rivers within a seasonal landscape in the central North China block during the Lopingian.

关键词： Shanxiopitys zhangziensis gen.et sp.nov. wood ecology geography gallery forest Lopingian North China