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Countercurrent imbibition in low-permeability porous media: Nondiffusive behavior and implications in tight oil recovery

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Petroleum Science 2023年第1期20卷 322-336页

作者： song-chao qi Hai-Yang Yu Xiao-Bing Han Hang Xu Tian-Bo Liang Xu Jin Xue-Feng Qu Yu-Jing Du Ke Xu State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China Research Institute of Petroleum Exploration and Development China National Petroleum CorporationBeijing100083China Research Institute of Exploration and Development PetroChina Changqing Oilfield CompanyXi'an710018ShaanxiChina School of Engineering and Applied Sciences Harvard UniversityMassachusetts02138United States College of Engineering Peking UniversityBeijing100871China

Countercurrent imbibition is an important mechanism for tight oil recovery,that is,water imbibes spontaneously from the fracture into the porous matrix while oil flows reversely into the *** significance over cocurrent imbibition and forced imbibition is highlighted when permeability *** used the computed tomography(CT)scanning to measure the one-dimensional evolution of water saturation profile and countercurrent imbibition distance(CID)at different fluid pressures,initial water saturations,and ***,experiments show that CID evolution for tight reservoir cores dramatically deviates from the classical diffusive rule(i.e.,evolutes proportional to square root of time,t^(0.5)).At early stage,CID extends faster than t^(0.5)(super-diffusive);while at late stage,CID extends much slower than t^(0.5)(sub-diffusive).After tens of hours,the CID change becomes too slow to be practically efficient for tight oil *** research demonstrates that this deviation from classic theory is a result of(1)a much longer characteristic capillary length than effective invasion depth,which eliminates full development of a classical displacement front;and(2)non-zero flow at low water saturation,which was always neglected for conventional reservoir and is amplified in sub-mili-Darcy *** well depict the details of the imbibition front in this situation,we introduce non-zero wetting phase fluidity at low saturation into classical countercurrent imbibition model and conduct numerical simulations,which successfully rationalizes the non-diffusive behavior and fits experimental *** data and theory imply an optimum soaking time in tight oil recovery by countercurrent imbibition,beyond which increasing exposed fracture surface area becomes a more efficient enhanced oil recovery(EOR)strategy than soaking for longer time.

关键词： Countercurrent spontaneous imbibition Tight reservoir Imbibition mechanism Tight oil development

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Potential role of tanycyte-derived neurogenesis in Alzheimer's disease

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Neural Regeneration Research 2025年第6期20卷 1599-1612页

作者： Guibo qi Han Tang Jianian Hu Siying Kang song qin Department of Anatomy Histologyand EmbryologySchool of Basic Medical SciencesFudan UniversityShanghaiChina State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science Fudan UniversityShanghaiChina

Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. The precise coordination of the gene networks controlling neurogenesis in naive and mature tanycytes is essential for maintaining homeostasis in adulthood. However, our understanding of the molecular mechanisms and signaling pathways that govern the proliferation and differentiation of tanycytes into neurons remains limited. This article aims to review the recent advancements in research into the mechanisms and functions of tanycyte-derived neurogenesis. Studies employing lineage-tracing techniques have revealed that the neurogenesis specifically originating from tanycytes in the hypothalamus has a compensatory role in neuronal loss and helps maintain energy homeostasis during metabolic diseases. Intriguingly,metabolic disorders are considered early biomarkers of Alzheimer's disease. Furthermore,the neurogenic potential of tanycytes and the state of newborn neurons derived from tanycytes heavily depend on the maintenance of mild microenvironments, which may be disrupted in Alzheimer's disease due to the impaired blood–brain barrier ***, the specific alterations and regulatory mechanisms governing tanycyte-derived neurogenesis in Alzheimer's disease remain unclear. Accumulating evidence suggests that tanycyte-derived neurogenesis might be impaired in Alzheimer's disease, exacerbating neurodegeneration. Confirming this hypothesis, however, poses a challenge because of the lack of long-term tracing and nucleus-specific analyses of newborn neurons in the hypothalamus of patients with Alzheimer's disease. Further research into the molecular mechanisms underlying tanycyte-derived neurogenesis holds promise for identifying small molecules capable of restoring tanycyte proliferation in neurodegenerative diseases. This line of investigation could pro

关键词： Alzheimer's disease blood–brain barrier ependymoglial cells hypothalamus metabolic diseases neural stem cells neurogenesis neuroinflammatory diseases neurons tanycyte

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微小型纵弯复合激励式圆筒超声电机的设计

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电测与仪表 2013年第11期50卷 106-109页

作者：宋起超周真哈尔滨理工大学测控技术与通信工程学院哈尔滨150040 测控技术与仪器黑龙江省高校重点实验室哈尔滨150040 黑龙江工程学院哈尔滨150050

为了有效提高超声电机的机械输出性能,研制了一种微小型贴片式纵弯复合激励式圆筒型行波超声电机。该电机由圆筒和一个纵弯复合换能器组成,换能器位于圆筒的外侧壁上,换能器由一对弯振压电陶瓷片、一对纵振压电陶瓷片和前端为变幅杆的... 详细信息

为了有效提高超声电机的机械输出性能,研制了一种微小型贴片式纵弯复合激励式圆筒型行波超声电机。该电机由圆筒和一个纵弯复合换能器组成,换能器位于圆筒的外侧壁上,换能器由一对弯振压电陶瓷片、一对纵振压电陶瓷片和前端为变幅杆的长方形铝块组成。对电机的工作原理进行了分析,利用有限元方法对电机进行了设计与仿真,实现了电机两个基本振动模态特征频率的简并。对振动特性进行了测试,测试结果与有限元分析结果吻合良好。测试结果表明,换能器的纵振、弯振和圆筒弯振模态之间均实现了很好的匹配。

关键词：超声电机纵弯式振动模态贴片式频率简并

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我国医疗保障体系主体制度模式选择研究

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中央财经大学学报 2008年第6期 1-7页

作者：宋其超郭雪剑中国社会科学院社会学研究所北京100732 中国人民大学财政金融学院北京100872

党的十七大报告明确提出了建立基本医疗卫生制度,提高全民健康水平。联系到近年来我国医改争论,相关部门和专家学者对基本医疗卫生制度具体内涵的理解并不一致。就我国医疗保障体系的主体制度来说,当前主要有两种观点:一种是强调税收筹... 详细信息

党的十七大报告明确提出了建立基本医疗卫生制度,提高全民健康水平。联系到近年来我国医改争论,相关部门和专家学者对基本医疗卫生制度具体内涵的理解并不一致。就我国医疗保障体系的主体制度来说,当前主要有两种观点:一种是强调税收筹资的全民免费医疗模式,另一种是强调保险筹资的社会医疗保险模式。借鉴国外相关经验和教训,立足现实国情,我国应该发展以保险筹资的社会医疗保险为主体制度的城乡医疗保障体系。

关键词：医疗保障医疗改革社会医疗保险全民免费医疗

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无源化汽车轮胎压力监测系统设计与实现

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黑龙江交通科技 2007年第5期30卷 88-88,90页

作者：宋起超黑龙江工程学院

在现有的TPMS(Tire Pressure Monitoring System)基础上提出了一种无源TPMS,该系统能够对轮胎的参数进行实时测量,当轮胎参数出现异常时立即报警。通过在轮胎内部安装微型的压力和温度传感器(NPX1),中央控制单元(NPXC01746)对轮胎内部... 详细信息

在现有的TPMS(Tire Pressure Monitoring System)基础上提出了一种无源TPMS,该系统能够对轮胎的参数进行实时测量,当轮胎参数出现异常时立即报警。通过在轮胎内部安装微型的压力和温度传感器(NPX1),中央控制单元(NPXC01746)对轮胎内部的温度、压力值进行采集、处理后,通过无线通信的方式将数据发送给驾驶室内部的中央监视器,中央监视器对轮胎的数据进行分析,如果发现轮胎的状态异常,则通过声光报警提示驾驶员进行处理,以避免交通事故的发生。

关键词：汽车电子轮胎压力无源监测

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Multilevel analysis of the central-peripheral-target organ pathway:contributing to recovery after peripheral nerve injury

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Neural Regeneration Research 2025年第10期20卷 2807-2822页

作者： Xizi song Ruixin Li Xiaolei Chu qi Li Ruihua Li qingwen Li Kai-Yu Tong Xiaosong Gu Dong Ming Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjinChina Haihe Laboratory of Brain-Machine Interface and Human-Machine Fusion TianjinChina Department of Rehabilitation Tianjin University Tianjin HospitalTianjinChina Department of Hand Microsurgery Tianjin University Tianjin HospitalTianjinChina School of Exercise and Health Tianjin University of SportTianjinChina Department of Biomedical Engineering the Chinese University of Hong KongHong Kong Special Administrative RegionChina

Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and *** on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites,neglecting multilevel pathological analysis of the overall nervous system and target *** has led to restrictions on current therapeutic *** this paper,we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective,covering the central nervous system,peripheral nervous system,and target *** peripheral nerve injury,the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves;changes such as neuronal apoptosis and axonal demyelination occur in the spinal *** nerve will undergo axonal regeneration,activation of Schwann cells,inflammatory response,and vascular system regeneration at the injury *** damage to target organs can occur,including skeletal muscle atrophy and sensory receptor *** then provide a brief review of the research advances in therapeutic approaches to peripheral nerve *** main current treatments are conducted passively and include physical factor rehabilitation,pharmacological treatments,cell-based therapies,and physical ***,most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ ***,we should further explore multilevel treatment options that produce effective,long-lasting results,perhaps requiring a combination of passive(traditional)and active(novel)treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery.

关键词： central nervous system central peripheral target organ multilevel pathological analysis nerve regeneration peripheral nerve injury peripheral nervous system target organs therapeutic approach

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贴片式纵弯复合激励圆筒超声电机

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哈尔滨理工大学学报 2013年第6期18卷 90-94页

作者：宋起超周真哈尔滨理工大学测控技术与仪器黑龙江省高校重点实验室黑龙江哈尔滨150080 黑龙江工程学院电气与信息工程学院黑龙江哈尔滨150050

为了有效提高贴片式环形行波超声电机的机械输出性能,利于超声电机的小型化和微型化,研制了一种贴片式纵弯复合激励圆筒超声电机,电机利用d33工作模式和d31工作模式,由单臂变幅杆和一个环形换能器构成,且变幅杆和换能器采用一体结构.在... 详细信息

为了有效提高贴片式环形行波超声电机的机械输出性能,利于超声电机的小型化和微型化,研制了一种贴片式纵弯复合激励圆筒超声电机,电机利用d33工作模式和d31工作模式,由单臂变幅杆和一个环形换能器构成,且变幅杆和换能器采用一体结构.在对电机的工作原理进行分析的基础上,利用ANSYS软件完成了电机的设计和仿真,实现了两个振动模态的特征频率简并,并采用多普勒激光测振仪对样机进行了振动测试,测试结果与仿真结果基本一致.样机的机械输出特性测试表明,样机的最大转速为268r/min,最大输出力矩为1.1N·m.

关键词：超声电机纵弯激励工作模态特征频率圆筒型

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基于单片机技术的压力测控仪的设计

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黑龙江工程学院学报 2007年第4期21卷 56-58页

作者：宋起超邵国平黑龙江工程学院电子工程系黑龙江哈尔滨150050

以扩散硅压力传感器、变送器为测量部件,应用单片机技术对液体压力进行测量的一套扩散硅液体压力检测系统。介绍压力检测系统检测原理、方法以及系统软件结构,对产生测量误差的原因进行分析,并提出解决的途径和方法。该测控仪检测精度... 详细信息

以扩散硅压力传感器、变送器为测量部件,应用单片机技术对液体压力进行测量的一套扩散硅液体压力检测系统。介绍压力检测系统检测原理、方法以及系统软件结构,对产生测量误差的原因进行分析,并提出解决的途径和方法。该测控仪检测精度高、使用简单、成本较低、工作稳定可靠。

关键词：液体压力 AT89s52 设计

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High-selectivity electroreduction of low-concentration CO2 with large concentration fluctuation

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Science China Chemistry 2025年

作者： Mengyu qi Yanbin Ma chao Zhang Bingwei Li Xueqing Yang Zhaolin Shi Simeng Liu Changhua An Jiqing Jiao Tongbu Lu MOE International Joint Laboratory of Materials Microstructure Analysis and Testing CenterInstitute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringSchool of Chemistry and Chemical EngineeringTianjin University of Technology Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Nankai University

Electrochemical CO2reduction reaction（CO2RR） has been regarded as one of the most promising solutions to achieving “zero carbon emission”. In most of the CO2RR-related studies, high-purity CO2has been employed as the feed gas; however, in practice, CO2is generally emitted in low concentrations, so it is of great significance to realize high-selectivity electroreduction of low-concentration CO2with large concentration fluctuation. In this work, we constructed a dual-active-site catalyst and successfully achieved CO2local enrichment and conversion for low-concentration CO2. Operando experiments reveal that the catalyst has one type of site for activating CO2and one type of site for binding the reaction intermediates. The dual-active-site catalyst displays a selectivity for formic acid consistently above 97% over a broad potential window（from-0.9 to-1.6 V ***）. Even when fed with a low-concentration CO2stream（volume ratio from 50% down to 10%）, the dual-active-site catalyst could display high activity and selectivity（>91%）. In particular, the selectivity is still above 85% when the CO2volume ratio is as low as 5%. This work offers a feasible route for converting low-concentration CO2via a synergistic effect for dual-active-site catalysts.

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Practical approach for detecting k-nonseparability of multipartite quantum states

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 32-48页

作者： Jie Guo Jinchuan Hou Xiaofei qi Kan He College of Mathematics Taiyuan University of Technology School of Mathematics and Statistics Shanxi University Key Laboratory of Complex Systems and Data Science of Ministry of Education Shanxi University

The instantaneous detection of entanglement in quantum states poses a significant challenge in the fields of quantum computation and quantum information, and there are no practical methods or tools to complete this task satisfactorily so far. We propose a sufficient and necessary criterion of k-nonseparability for any n-partite finite or infinite dimensional systems, 2 ≤ k ≤ n. This criterion serves as the foundation for a practical scheme designed to detect entanglement and k-nonseparability across multipartite finite-dimensional systems. To exemplify the application of our scheme, we have developed a software tool that facilitates swift and precise identification of entanglement, k-nonseparability, and genuine entanglement within n-qubit systems, specifically tailored for systems with 2 ≤ n ≤ 4.

关键词： multipartite systems entanglement states entanglement witnesses ${\bm~k}$-nonseparability

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