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Study of the pressure transient behavior of directional wells considering the effect of non-uniform flux distribution

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Petroleum Science 2024年第3期21卷 1765-1779页

作者： Yan-Zhong Liang bai-lu teng Wan-Jing luo School of Energy Resources China University of Geosciences(Beijing)Beijing100083China

During the production,the fluid in the vicinity of the directional well enters the wellbore with different rates,leading to non-uniform flux distribution along the directional ***,in all existing studies,it is oversimplified to a uniform flux distribution,which can result in inaccurate results for field ***,this paper proposes a semi-analytical model of a directional well based on the assumption of non-uniform flux ***,the direction well is discretized into a carefully chosen series of linear sources,such that the complex well trajectory can be captured and the nonuniform flux distribution along the wellbore can be considered to model the three-dimensional flow *** using the finite difference method,we can obtain the numerical solutions of the transient flow within the *** the aid of Green's function method,we can obtain the analytical solutions of the transient flow from the matrix to the *** complete flow behavior of a directional well is perfectly represented by coupling the above two types of transient ***,on the basis of the proposed model,we conduct a comprehensive analysis of the pressure transient behavior of a directional *** computation results show that the flux variation along the direction well has a significant effect on pressure *** addition,the directional well in an infinite reservoir may exhibit the following flow regimes:wellbore afterflow,transition flow,inclined radial flow,elliptical flow,horizontal linear flow,and horizontal radial *** horizontal linear flow can be observed only if the formation thickness is much smaller than the well ***,a dip region that appears on the pressure derivative curve indicates the three-dimensional flow behavior near the wellbore.

关键词： Directional well Pressure transient behavior Semi-analytical model Non-uniform flux

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The role of exosomes in adult neurogenesis:implications for neurodegenerative diseases

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Neural Regeneration Research 2024年第2期19卷 282-288页

作者： Zhuoyang Yu Yan teng Jing Yang lu Yang Institute of Neurology Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Laboratory of Aging Research School of MedicineUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina

Exosomes are cup-shaped extracellular vesicles with a lipid bilayer that is approximately 30 to 200 nm in *** are widely distributed in a range of body fluids,including urine,blood,milk,and *** exert biological function by transporting factors between different cells and by regulating biological pathways in recipient *** an important form of intercellular communication,exosomes are increasingly being investigated due to their ability to transfer bioactive molecules such as lipids,proteins,mRNAs,and microRNAs between cells,and because they can regulate physiological and pathological processes in the central nervous *** neurogenesis is a multistage process by which new neurons are generated and migrate to be integrated into existing neuronal *** the adult brain,neurogenesis is mainly localized in two specialized niches:the subventricular zone adjacent to the lateral ventricles and the subgranular zone of the dentate *** increasing body of evidence indicates that adult neurogenesis is tightly controlled by environmental conditions with the *** recent studies,exosomes released from different sources of cells were shown to play an active role in regulating neurogenesis both in vitro and in vivo,thereby participating in the progression of neurodegenerative disorders in patients and in various disease ***,we provide a state-of-the-art synopsis of existing research that aimed to identify the diverse components of exosome cargoes and elucidate the therapeutic potential of exosomal contents in the regulation of neurogenesis in several neurodegenerative *** emphasize that exosomal cargoes could serve as a potential biomarker to monitor functional neurogenesis in *** addition,exosomes can also be considered as a novel therapeutic approach to treat various neurodegenerative disorders by improving endogenous neurogenesis to mitigate neuronal loss in the central nervous system.

关键词： adult neurogenesis Alzheimer’s disease amyotrophic lateral sclerosis exosome Huntington’s disease neurodegenerative disease neurogenic niches Parkinson’s disease

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Eutectogel-based self-powered wearable sensor for health monitoring in harsh environments

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Nano Research 2024年第6期17卷 5559-5568页

作者： Junpeng Wu Xinru teng lu Liu Hongzhi Cui Xiaoyi Li College of Materials Science and Engineering Ocean University of ChinaQingdao 266100China Key Lab for Special Functional Materials of Ministry of Education School of Materials Science and EngineeringHenan UniversityKaifeng 475004China

Triboelectric nanogenerators(teng)have emerged as a highly promising energy harvesting technology,attracting significant attention in recent years for their broad ***-based tengs,with superior stretchability and sensitivity,have been widely reported as wearable ***,the traditional hydrogel-based tengs suffer from freezing at low temperatures and drying at high temperatures,resulting in *** this study,we introduce an anti-freezing eutectogel,which uses a deep eutectic solvent(DES),to improve the stability and electrical conductivity of tengs in harsh environmental *** eutectogel-based teng(E-teng)produces an open-circuit voltage of 776 V,a short-circuit current of 1.54μA,and a maximum peak power of 1.1 ***,the E-teng exhibits exceptional mechanical properties with an elongation at a break of 476%under ***,it maintains impressive performances across a wide temperature range from−18 to 60℃,with conductivities of 2.15 S/m at−10℃and 1.75 S/m at−18℃.Based on the excellent weight stability of the E-teng sensor,motion sensing can be achieved in the air,and even ***,the versatility of the E-teng can serve as a wearable sensor,by integrating it with Bluetooth *** self-powered E-teng can monitor various human motion signals in real-time and send the health signals directly to mobile *** research paves a new road for the applications of tengs in harsh environments,offering wireless flexible sensors with real-time health signal monitoring capabilities.

关键词： triboelectric nanogenerators self-powered harsh environment health monitoring Eutectogel

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Efficient Dynamic Locomotion of Quadruped Robot via Adaptive Diagonal Gait

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Journal of Bionic Engineering 2024年第1期21卷 126-136页

作者： Jian Bi teng Chen Xuewen Rong Guoteng Zhang Guanglin lu Jingxuan Cao Han Jiang Yibin Li The Center for Robotics School of Control Science and EngineeringShandong UniversityJi Nan 250000China

Quadruped animals in the nature realize high energy efficiency locomotion by automatically changing their gait at different *** by this character,an efficient adaptive diagonal gait locomotion controller is designed for quadruped robot.A unique gait planning method is proposed in this *** the speed of robot varies,the gait cycle time and the proportion of stance and swing phase of each leg are adjusted to form a variety of *** optimal joint torque is calculated by the controller combined with Virtual Model Control(VMC)and Whole-Body Control(WBC)to realize the desired *** gait and step frequency of the robot can automatically adapt to the change of *** experiments are done with a quadruped robot made by our laboratory to verify that the gait can change automatically from slow-trotting to flying-trot during the period when speed is from 0 to 4 m/*** ratio of swing phase is from less than 0.5 to more than 0.5 to realize the running motion with four feet off the *** have shown that the controller can indeed consume less energy when robot runs at a wide range of speeds comparing to the basic controller.

关键词： Quadruped robot Gait transition Adaptive gait Energy efficiency

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Climate warming is likely to weaken the performance of two-phase closed thermosyphon on the Qinghai-Tibet Plateau

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Advances in Climate Change Research 2024年第1期15卷 90-100页

作者： Guan-Li JIANG Zi-teng FU Xin-Yu MEN Hong-Ting ZHAO Si-Ru GAO Yong-Zhi LI Qing-bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Beiluhe Observation and Research Station on Frozen Soil Engineering and Environment in the Qinghai-Tibet Plateau Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Muli Field Scientific Observation and Research Station for Gas Hydrate China Geological SurveyBeijing 100083China University of Chinese Academy of Sciences Beijing 100049China School of Civil Engineering and Architecture Jiaxing Nanhu UniversityJiaxing 314001China

Over the years,numerous geotechnical approaches have been implemented to mitigate the adverse effects of climate warming on various infrastructures in the permafrost region of the Qinghai-Tibet Plateau(QTP),such as the Qinghai-Tibet Highway and Railway,and achieved the expected engineering ***,little attention has been given to whether the performance of these geotechnical approaches has changed during the ongoing process of climate *** investigate the performance variation of one of these geotechnical approaches,which is two-phase closed thermosyphon(TPCT),during sustained climate warming,we conducted a statistical analysis of soil temperature monitoring data in 2003-2020 from eight regular embankments and six TPCT embankments in our permafrost monitoring *** results indicate that TPCT undeniably has a cooling effect on the permafrost beneath embankments,even rapidly eliminated previously formed taliks beneath ***,further analysis reveals that the performance of TPCT has been weakening during sustained climate warming,which has confirmed by the re-forming of the taliks beneath embankment where they had been previously *** on the current understanding,we attributed the weakening of thermosyphon performance to a significant reduction in the air temperature freezing index caused by ongoing climate *** this study,we aimed to draw attention to the evolving performance of geotechnical approaches in permafrost regions amid climate warming,prompting necessary engineering innovations to address this situation and ensure the sustainable development of the permafrost region on the QTP.

关键词： Two-phase closed thermosyphon Climate warming Supra-permafrost talik Permafrost degradation Qinghai-Tibet Highway

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Polyoxometalate-based flexible conductive materials with superionic conductivity

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Science China Chemistry 2024年

作者： Yuxin Wang Shuping Xue Jun Geng Ying lu teng Li Xiaozheng Duan Xue bai Yanli Yang Jingqi Yang Shuxia Liu Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education College of Chemistry Northeast Normal University State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Flexible ion-conductive materials exhibit intriguing advantages for applications in flexible electronic devices. Currently, the further enhancement of their conductivity within environmental limitations is an urgent demand for the development of flexible electronic devices, yet remains as a great challenge. Herein, we report a “dual-acid” strategy, via the encapsulation of two acids,H3PW12O40（HPW） and NH2SO3H（SA）, with synergistic interaction into poly（vinyl alcohol）-glycerol（PVA-Gly） hydrogel, to achieve polyoxometalate（POM）-based flexible materials with superionic conductivity under various environmental *** a representative example, the prepared PVA-Gly/HPW-SA-20% hydrogel presents an ultrahigh proton conductivity ranging from-30 °C(3.33×10-2S cm-1) to room temperature(2.78×10-1S cm-1) under ambient humidity. Moreover, the PVA-Gly/HPW-SA-20% hydrogel exhibits remarkable advantages in anti-freezing, mechanical flexibility and self-adhesiveness, making it a promising multifunctional electrolyte for flexible electronic devices. Both experimental results and molecular dynamics（MD）simulations jointly demonstrate that SA bridges HPW clusters to form a dense proton transport pathway induced by multiple electrostatic and hydrogen bonding interactions between SA and HPW counterparts, which contributes to the high-level proton conductivity of the PVA-Gly/HPW-SA-20% hydrogel. This work provides new insights into the design of POM-based flexible materials with superionic conductivity.

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Tuning the ferroelectricity of Hf0.5Zr0.5O2 with alloy electrodes

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Science China(Information Sciences) 2024年第8期67卷 321-330页

作者： Keqin LIU Bingjie DANG Zhiyu YANG teng ZHANG Zhen YANG Jinxuan bai Zelun PAN Ru HUANG Yuchao YANG Beijing Advanced Innovation Center for Integrated Circuits School of Integrated Circuits Peking University School of Electronic and Computer Engineering Peking University Center for Brain Inspired Chips Institute for Artificial Intelligence Peking University Center for Brain Inspired Intelligence Chinese Institute for Brain ResearchBeijing

Tuning ferroelectricity of Hf0.5Zr0.5O2is crucial for facilitating its practical applications in various fields, including in-memory and neuromorphic computing. Previous studies have revealed that the electrodes have a significant influence on ferroelectricity, and changing electrode materials can realize different but discrete ferroelectric polarization values. Here, we introduce an alloy-electrode method, in order to achieve gradual and accurate modulation of ferroelectric polarization, especially useful for matching the polarization charges at the interface of ferroelectric insulators and ferroelectric semiconductors. Au and W electrodes are chosen as baselines for realizing weak and strong ferroelectric polarization, where the intermediate states can be achieved by adjusting the ratio of metals in the Au-W alloy. To demonstrate the generality of this approach, the Cu-W alloy electrode is also realized for tuning ferroelectric polarization. The effect of alloy electrodes on device leakage current, endurance, and retention is evaluated. In addition, the temperature stability of ferroelectric capacitors is tested, where limited changes in both remnant polarization and coercive voltages are observed, showing the great potential of the ferroelectric hafnium oxide. Such gradual modulation of ferroelectric polarization could facilitate the application of Hf0.5Zr0.5O2in in-memory and neuromorphic computing.

关键词： ferroelectric hafnium oxide alloy electrode gradual modulation temperature stability

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Durable K-ion batteries with 100% capacity retention up to 40,000 cycles

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Carbon Energy 2024年第5期6卷 201-212页

作者： Xianlu lu Zhao Liang Zhi Fang Dongdong Zhang Yapeng Zheng Qiao Liu Dingfa Fu Jie teng Weiyou Yang Institute of Micro/Nano Materials and Devices Ningbo University of TechnologyNingboZhejiangChina College of Materials Science and Engineering Hunan UniversityChangshaChina College of Mechanical and Vehicle Engineering Hunan UniversityChangshaChina

Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induced by the large radius of K+***,we explore high-performance K-ion half/full batteries with high rate capability,high specific capacity,and extremely durable cycle stability based on carbon nanosheets with tailored N dopants,which can alleviate the change of volume,increase electronic conductivity,and enhance the K+ion *** as-assembled K-ion half-batteries show an excellent rate capability of 468 mA h g^(−1) at 100 mA g^(−1),which is superior to those of most carbon materials reported to ***,the as-assembled half-cells have an outstanding life span,running 40,000 cycles over 8 months with a specific capacity retention of 100%at a high current density of 2000 mA g^(−1),and the target full cells deliver a high reversible specific capacity of 146 mA h g^(−1) after 2000 cycles over 2 months,with a specific capacity retention of 113%at a high current density of 500 mA g^(−1),both of which are state of the art in the field of K-ion *** study might provide some insights into and potential avenues for exploration of advanced K-ion batteries with durable stability for practical applications.

关键词： carbon nanosheet cycle stability K-ion batteries rate performance specific capacity

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S-scheme heterojunction in photocatalytic hydrogen production

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Journal of Materials Science & Technology 2024年第2期169卷 82-104页

作者： teng Li Noritatsu Tsubaki Zhiliang Jin School of Chemistry and Chemical Engineering North Minzu UniversityYinchuan 750021China Department of Applied Chemistry Graduate School of EngineeringUniversity of ToyamaGofuku 3190Toyama 930-8555Japan

As an ideal secondary energy source,hydrogen has the title of clean energy and the product of its complete combustion is only water,which is not polluting to the *** hydrogen production technology is an environmentally friendly,safe,and low-cost strategy that requires only an inexhaustible amount of solar energy and water as *** paper provides a detailed and detailed review of S-scheme heterojunction photocatalysts for photocatalytic hydrogen production,mainly including TiO_(2)-based,Perovskite-based,CdS-based,Graphitic phase carbon nitride-based,COF-based graphdiyne-based,ZnO-based,and ZnIn_(2)S_(4)-based S-scheme heterojunction *** classification of S-scheme heterojunctions is ***’s more,various characterizations for direct verification of the charge migration mechanism of S-scheme heterojunctions are *** on the present study,the future potential challenges and future research trends for S-scheme heterojunctions in photocatalytic hydrogen evolution technology are pointed out,which provides feasible strategies for the development and design of S-scheme heterojunction photocatalysts in the field of photocatalytic hydrogen evolution.

关键词： S-scheme heterojunction Photocatalysis Charges migration Hydrogen evolution

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Room-temperature phonon-coupled single-photon emission in hexagonal boron nitride

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 109-114页

作者： Jia-Min Lai Qing-Hai Tan Feilong Song Haonan Chang Yanpei Lv Xue-lu Liu Jinghua teng Weibo Gao Ping-Heng Tan Jun Zhang State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing100083China Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education&Research Institute of Materials Science Shanxi Normal UniversityTaiyuan 030000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Institute of Materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore

Photon-lattice(phonon)coupling is fundamental to light-matter interaction,particularly when it reaches the quantum limit of the phonon-coupled single-photon emission,which holds great potential for quantum manipulation and quantum information ***,we report single defect state-phonon coupling in hexagonal boron nitride(h BN)at room *** ultrabroad spectrum of single-photon emissions can be achieved by selecting the excitation *** photoluminescence excitation spectroscopy,we observe single-phonon-assisted resonance-enhanced single-photon emission,along with multiple phonon replicas that herald the creation of phonon Fock *** also develop a transition model to gain insight into the physical process behind the single defect state-phonon *** work sets the stage for manipulating electron-phonon coupling state with single quantum-level precision at room temperature.

关键词： temperature phonon hexagonal

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