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Study on the clogging mechanism of punching screen in sand control by the punching structure parameters

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Petroleum Science 2024年第1期21卷 609-620页

作者： fu-cheng Deng fu-Lin Gui Bai-Tao Fan Lei Wen Sheng-Hong Chen Ning Gong Yun-Chen Xiao Zhi-Hui Xu Yangtze University Jingzhou434023HubeiChina CNOOC Research Institute Ltd. Beijing100028China CNOOC Ener Tech-Drilling&Production Co. Tianjin300457China Tianjin Branch of CNOOC Ltd. Tianjin300459China

As an independent sand control unit or a common protective shell of a high-quality screen,the punching screen is the outermost sand retaining unit of the sand control pipe which is used in geothermal well or oil and gas ***,most screens only consider the influence of the internal sand retaining medium parameters in the sand control performance design while ignoring the influence of the plugging of the punching screen on the overall sand retaining performance of the *** explore the clogging mechanism of the punching screen,this paper established the clogging mechanism calculation model of a single punching screen sand control unit by using the computational fluid mechanics-discrete element method(CFD-DEM)combined *** to the combined motion of particles and fluids,the influence of the internal flow state on particle motion and accumulation was *** results showed that(1)the clogging process of the punching sand control unit is divided into three stages:initial clogging,aggravation of clogging and stability of *** the initial stage of blockage,coarse particles form a loose bridge structure,and blockage often occurs preferentially at the streamline gathering place below chamfering inside the sand control *** the stage of blockage intensification,the particle mass develops into a relatively complete sand bridge,which develops from both ends of the opening to the center of the *** the stable plugging stage,the sand deposits show a“fan shape”and form a“V-shaped”gully inside the punching slot element.(2)Under a certain reservoir particle-size distribution,The slit length and opening height have a large influence on the permeability and blockage rate,while the slit width size has little influence on the permeability and blockage *** microscopic clogging mechanism and its law of the punching screen prevention unit are proposed in this study,which has some field guidance significance for the design of punching screen

关键词： Punching screen Plugging CFD-DEM Size parameter Sand control

Static recrystallization behaviors and mechanisms of 7Mo super-austenitic stainless steel with undissolved sigma precipitates during double-stage hot deformation

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Journal of Iron and Steel Research(International) 2024年第2期31卷 475-487页

作者： Shi-guang Xu Jin-shan He Run-ze Zhang fu-cheng Zhang Xi-tao Wang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004HebeiChina Shandong Provincial Key Laboratory for High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Science)Jinan250353ShandongChina

Static recrystallization(SRX)behaviors and corresponding recrystallization mechanisms of 7Mo super-austenitic stainless steel were studied under different deformation *** order of influence of deformation parameters on static recrystallization behaviors,from high to low,is followed by temperature,first-stage strain and strain ***,the effect of holding time on static recrystallization behaviors is significantly controlled by *** addition,with the increase in temperature from 1000 to 1200°C,the static recrystallization mechanism evolves from discontinuous static recrystallization and continuous static recrystallization(cSRX)to metadynamic recrystallization and cSRX,and finally to *** cSRX exists at all *** is because high stacking fault energy(56 mJ m−2)promotes the movement of dislocations,making the deformation mechanism of this steel is dominated by planar slip of *** undissolved sigma precipitates promote static recrystallization through particle-stimulated ***,small strain-induced precipitates at grain boundaries hinder the nucleation of conventional SRX and the growth of recrystallized grains,while the hindering effect decreases with the increase in temperature.

关键词： 7Mo super-austenitic stainless steel Double-stage hot deformation Conventional static recrystallization Metadynamic recrystallization Strain-induced precipitation

Cryptic diversity and rampant hybridization in annual gentians on the Qinghai-Tibet Plateau revealed by population genomic analysis

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Plant Diversity 2024年第2期46卷 194-205页

作者： Peng-cheng fu Qiao-Qiao Guo Di Chang Qing-Bo Gao Shan-Shan Sun School of Life Science Luoyang Normal UniversityLuoyang 471934PR China Key Laboratory of Adaptation and Evolution of Plateau Biota Northwest Institute of Plateau BiologyChinese Academy of SciencesXining 810001PR China

Understanding the evolutionary and ecological processes involved in population differentiation and speciation provides critical insights into biodiversity formation. In this study, we employed 29,865 single nucleotide polymorphisms(SNPs) and complete plastomes to examine genomic divergence and hybridization in Gentiana aristata, which is endemic to the Qinghai-Tibet Plateau(QTP) region. Genetic clustering revealed that G. aristata is characterized by geographic genetic structures with five clusters(West, East, Central, South and North). The West cluster has a specific morphological character(i.e., blue corolla) and higher values of FSTcompared to the remaining clusters, likely the result of the geological barrier formed by the Yangtze River. The West cluster diverged from the other clusters in the Early Pliocene;these remaining clusters diverged from one another in the Early Quaternary. Phylogenetic reconstructions based on SNPs and plastid data revealed substantial cyto-nuclear conflicts. Genetic clustering and D-statistics demonstrated rampant hybridization between the Central and North clusters,along the Bayankala Mountains, which form the geological barrier between the Central and North clusters. Species distribution modeling demonstrated the range of G. aristata expanded since the Last Interglacial period. Our findings provide genetic and morphological evidence of cryptic diversity in G. aristata, and identified rampant hybridization between genetic clusters along a geological *** findings suggest that geological barriers and climatic fluctuations have an important role in triggering diversification as well as hybridization, indicating that cryptic diversity and hybridization are essential factors in biodiversity formation within the QTP region.

关键词： Gentiana aristata Hybrid zone Qinghai-Tibet Plateau Plastome Nuclear SNPs

Nanocomposite: Keggin-type Co_(4)-polyoxometalate@cobaltporphyrin linked graphdiyne for hydrogen evolution in seawater

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Nano Research 2024年第3期17卷 1281-1287页

作者： Jiejie Ping Danyang He Fei Wang Nan Wang Yi-cheng fu Zihao Xing Zhiyu Jia Guo-Yu Yang Key Laboratory of Cluster Science Ministry of EducationSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Facluty of Chmeistry Northeast Normal UniversityChangchun 130024China Peking University Third Hospital Beijing 100190China

Polyoxometalate-based nanocomposites with electrocatalytic activity have been applied in hydrogen evolution reactions(HER).Seawater as the main water resource on the earth should be developed as the water electrolysis to prepare high-purity *** this paper,we used two synthesis strategies to prepare the nanocomposite Co_(4)-POM@Co-PGDY(Co_(4)-POM:the Kegging-type microcrystals of K_(10)[Co_(4)(PW_(9)O_(3)4)2]and Co-PGDY:cobalt-porphyrin linked graphdiyne)with excellent activity for ***-PGDY as the porous material is applied not only as the protection of microcrystals towards the metal ion in seawater but also as the co-electrocatalyst of Co_(4)-***_(4)-POM@Co-PGDY exhibits excellent HER performance in seawater electrolytes with low overpotential and high stability at high ***,we have observed a key H_(3)O+intermediate emergence on the surface of nanocomposite during hydrogen evolution process in seawater by Raman synchrotron radiation-based Fourier transform infrared(SR-FTIR).The results in this paper provide an effective strategy for preparing polyoxometalate-based electrocatalysts with high-performance toward hydrogen evolution reaction.

关键词： polyoxometalate graphdiyne seawater hydrogen evolution reaction

Molecule-based vertical transistor via intermolecular charge transport throughπ-πstacking

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Nano Research 2024年第5期17卷 4573-4581页

作者： cheng Liu cheng fu Lingyu Tang Jianghua Wu Zhangyan Mu Yamei Sun Yanghang Pan Bailin Tian Kai Bao Jing Ma Qiyuan He Mengning Ding Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Jiangsu Key Laboratory of Advanced Organic Materials School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied SciencesCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China

Theπ-πstacking is a well-recognized intermolecular interaction that is responsible for the construction of electron hopping channels in numerous conducting frameworks/***,the exact role ofπ-to-πchannels within typical single crystalline organic semiconductors remains unclear as the orientations of these molecules are diverse,and their control usually requires additional side chain groups that misrepresent the intrinsic properties of the original semiconducting ***,the construction of conduction channels with intrinsicπ-πstacking in the molecule-based device is crucial for the utilization of their unique transport characteristics and understanding of the transport *** this end,we present a molecular intercalation strategy that integrates two-dimensional layered materials with functional organic semiconductor molecules for functional molecule-based *** organic semiconductor molecules can be effectively intercalated into the van der Waals gaps of semi-metallic TaS_(2) withπ-πstacking configuration and controlled intercalant *** results show that the vertical charge transport in the stacking direction shows a tunneling-dominated mechanism that strongly depends on the molecular ***,we demonstrated a new type of molecule-based vertical transistor in which TaS_(2) andπ-πstacked organic molecules function as the electrical contact and the active channel,***/off ratios as high as 447 are achieved under electrostatic modulation in ionic liquid,comparable to the current state-of-the-art molecular *** study provides an ideal platform for probing intrinsic charge transport acrossπ-πstacked conjugated molecules and also a feasible approach for the construction of high-performance molecule-based electronic devices.

关键词： π-πstacking electrochemical intercalation organic semiconductor electrical transport tunneling field effect transistor

Optimization of water-urban-agricultural-ecological land use pattern:A case study of Guanzhong Basin in the southern Loess Plateau of Shaanxi Province,China

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China Geology 2024年第3期7卷 480-493页

作者： Sai Wang Bin Wu Hai-xue Li Min-min Zhao Lei Yuan Xi Wu Tao Ma fu-cheng Li Shuang-bao Han Center for Hydrogeology and Environmental Geology Survey China Geological SurveyMinistry of Natural ResourcesTianjin 300304China Center for Groundwater Exploration and Development Engineering Research China Geological SurveyMinistry of Natural ResourcesTianjin 300304China School of Environmental Studies China University of GeosciencesWuhan430078China State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic ScienceChina University of GeosciencesWuhan430078China

Extensive land use will cause many environmental *** is an urgent task to improve land use efficiency and optimize land use *** recent years,due to the flow decrease,the Guanzhong Basin in Shaanxi Province is confronted with the problem of insufficient water resources *** on the Coupled Ground-Water and Surface-Water Flow Model(GSFLOW),this paper evaluates the response of water resources in the basin to changes in land use patterns,optimizes the land use pattern,improves the ecological and economic benefits,and the efficiency of various spatial development,providing a reference for ecological protection and high-quality development of the Yellow River *** research shows that the land use pattern in the Guanzhong Basin should be further *** the condition of considering ecological and economic development,the percentage change of the optimum area of farmland,forest,grassland,water area,and urban area compared with the current land use area ratio is+2.3,+2.4,-6.1,+0.2,and+1.6,*** economic and ecological value of land increases by14.1%and 3.1%,respectively,and the number of water resources can increase by 2.5%.

关键词： Coupled Ground-Water and Surface-Water Flow Model(GSFLOW) Land use patterns Water resources optimization Ecological and economic benefits Coupling model Hydrological environmental engineering Guanzhong Basin Southern Loess Plateau Yellow River basin

基于GUM法的风电叶片结构试验方法不确定度研究

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太阳能学报 2024年第5期45卷 126-132页

作者：邢海瑞傅程朱雷中国船级社质量认证有限公司北京100010

针对风电叶片全尺寸结构试验方法,首先分析试验过程中所需测量物理量的不确定度因素来源;其次利用GUM法建立不确定度数学模型,然后评定各部分输入量的标准不确定度;最后分析得到叶片结构试验各测试物理量的合成标准不确定度和扩展不确定... 详细信息

针对风电叶片全尺寸结构试验方法,首先分析试验过程中所需测量物理量的不确定度因素来源;其次利用GUM法建立不确定度数学模型,然后评定各部分输入量的标准不确定度;最后分析得到叶片结构试验各测试物理量的合成标准不确定度和扩展不确定度,从而建立风电叶片试验不确定度的系统评价方法。

关键词：风力机叶片不确定度分析全尺寸结构试验 GUM法

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液滴撞击单丝铺展特性的数值研究

化工学报 2024年第6期75卷 2233-2242页

作者：黄斌丰生杰傅程张威重庆科技大学石油与天然气工程学院重庆401331 东北石油大学石油工程学院黑龙江大庆163318

液滴撞击单丝现象在石油与天然气处理过程中广泛存在,研究液滴撞击单丝的铺展特性对于提高化工设备的热质传递效率有重要意义。基于VOF方法建立液滴撞击单丝的数值模型,系统研究了初始速度、初始直径、撞击偏心距、撞击角度对液滴铺展... 详细信息

液滴撞击单丝现象在石油与天然气处理过程中广泛存在,研究液滴撞击单丝的铺展特性对于提高化工设备的热质传递效率有重要意义。基于VOF方法建立液滴撞击单丝的数值模型,系统研究了初始速度、初始直径、撞击偏心距、撞击角度对液滴铺展因子的影响。结果表明,增加初始速度能加快铺展因子增长速率并延长其最大铺展因子的保持时间。减小液滴的初始直径显示出更高的铺展因子;缩短撞击偏心距有助于液滴的更充分铺展,控制在0.2R以内时铺展效果最佳;减小撞击角度也可促进液滴更充分地铺展,其中铺展因子曲线在不同撞击角度下存在一个铺展转换点。此外液膜中心与两侧压差驱动液滴快速铺展,直至达到最大铺展长度后停止。研究结果可为含有丝网填料的化工设备的优化设计提供理论参考。

关键词：液滴碰撞铺展因子铺展机制数值模拟

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Multiple pulp stones emerge across all teeth during mixed dentition:A case report

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World Journal of Clinical Cases 2024年第22期12卷 5189-5195页

作者： Yuan Lv Jie Zhu cheng-Tao fu Le Liu Jing Wang Yan-Feng Li Department of Stomatology China Aerospace Science&Industry Corporation 731 HospitalBeijing 100074China School of Medicine Huzhou UniversityHuzhou 313204Zhejiang ProvinceChina Department of Stomatology The Fourth Medical CentreChinese People's Liberation Army General HospitalBeijing 100048China

BACKGROUND This paper reports a rare presentation of multiple pulp stones(PSs)emerging in all teeth during mixed *** offers valuable insights into the clinical diagnosis,treatment,and prognosis of multiple PSs,shedding light on their occurrence during the mixed dentition *** SUMMARY A 10-year-old girl presented with repeated pain in the mandibular right posterior *** examination revealed carious lesions,abnormal tooth shapes,and anomalies in tooth *** examinations showed multiple PSs with diverse shapes,sizes,and quantities in all teeth,alongside anomalies in tooth shape and *** canal therapy was initiated,but the patient initially lacked timely *** return for treatment completion,an extracted tooth revealed irregular calculus within the pulp *** This case underscores the importance of considering multiple PSs in mixed dentition,necessitating comprehensive evaluation and management strategies.

关键词： Mixed dentition Multiple pulp stones Pulp calcification Cone-beam computed tomography Case report