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Damage evolution of rock-encased-backfill structure under stepwise cyclic triaxial loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 597-615页

作者： xin Yu Yuye Tan Weidong Song john Kemeny Shengwen Qi Bowen Zheng Songfeng Guo Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100089China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100089China University of Chinese Academy of Sciences Beijing100049China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of High-Efficient Mining and Safety of Metal Mines(Ministry of Education of China) University of Science and Technology BeijingBeijing100083China Department of Mining and Geological Engineering University of ArizonaTucsonAZ86721USA

Rock-encased-backfill(RB)structures are common in underground mining,for example in the cut-andfill and stoping *** understand the effects of cyclic excavation and blasting activities on the damage of these RB structures,a series of triaxial stepwise-increasing-amplitude cyclic loading experiments was conducted with cylindrical RB specimens(rock on outside,backfill on inside)with different volume fractions of rock(VF=0.48,0.61,0.73,and 0.84),confining pressures(0,6,9,and 12 MPa),and cyclic loading rates(200,300,400,and 500 N/s).The damage evolution and meso-crack formation during the cyclic tests were analyzed with results from stress-strain hysteresis loops,acoustic emission events,and post-failure X-ray 3D fracture *** results showed significant differences between cyclic and monotonic loadings of RB specimens,particularly with regard to the generation of shear microcracks,the development of stress memory and strain hardening,and the contact forces and associated friction that develops along the rock-backfill *** important finding is that as a function of the number of cycles,the elastic strain increases linearly and the dissipated energy increases ***,compared with monotonic loading,the cyclic strain hardening characteristics are more sensitive to rising confining pressures during the initial compaction *** finding is that compared with monotonic loading,more shear microcracks are generated during every reloading stage,but these microcracks tend to be dispersed and lessen the likelihood of large shear fracture *** transition from elastic to plastic behavior varies depending on the parameters of each test(confinement,volume fraction,and cyclic rate),and an interesting finding was that the transformation to plastic behavior is significantly lower under the conditions of 0.73 rock volume fraction,400 N/s cyclic loading rate,and 9 MPa *** the findings have important practical implications on t

关键词： Rock and backfill Triaxial cyclic loading Volume fraction Damage evolution 3D visualization

Targeting TrkB–PSD-95 coupling to mitigate neurological disorders

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Neural Regeneration Research 2025年第3期20卷 715-724页

作者： xin Yang Yu-Wen Alvin Huang john Marshall Department of Molecular Biology Cell Biology and BiochemistryBrown UniversityProvidenceRIUSA Department of Neurology Warren Alpert Medical School of Brown UniversityProvidenceRIUSA Center for Translational Neuroscience Robert J.and Nancy D.Carney Institute for Brain Science and Brown Institute for Translational ScienceBrown UniversityProvidenceRIUSA

Tropomyosin receptor kinase B(TrkB)signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and *** activity-dependent release of brain-derived neurotrophic factor at synapses binds to pre-or postsynaptic TrkB resulting in the strengthening of synapses,reflected by long-term ***,the association of postsynaptic density protein-95 with TrkB enhances phospholipase Cγ-Ca^(2+)/calmodulin-dependent protein kinaseⅡand phosphatidylinositol 3-kinase-mechanistic target of rapamycin signaling required for long-term *** this review,we discuss TrkB-postsynaptic density protein-95 coupling as a promising strategy to magnify brain-derived neurotrophic factor signaling towards the development of novel therapeutics for specific neurological disorders.A reduction of TrkB signaling has been observed in neurodegenerative disorders,such as Alzheimer's disease and Huntington's disease,and enhancement of postsynaptic density protein-95 association with TrkB signaling could mitigate the observed deficiency of neuronal connectivity in schizophrenia and *** with brain-derived neurotrophic factor is problematic,due to poor pharmacokinetics,low brain penetration,and side effects resulting from activation of the p75 neurotrophin receptor or the truncated TrkB.T1 *** TrkB agonists and antibodies that activate TrkB are being intensively investigated,they cannot distinguish the multiple human TrkB splicing isoforms or cell type-specific *** TrkB–postsynaptic density protein-95 coupling provides an alternative approach to specifically boost TrkB signaling at localized synaptic sites versus global stimulation that risks many adverse side effects.

关键词： Angelman syndrome autism brain-derived neurotrophic factor depression neurodegenerative disorder neurodevelopmental disorder postsynaptic density protein-95 synaptic plasticity TrkB

An Extended DC Power Flow Model Considering Voltage Magnitude

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Journal of Modern Power Systems and Clean Energy 2021年第3期9卷 679-683页

作者： Dundun Liu Lu Liu haozhong Cheng Shenxi Zhang Jieqing xin Laboratory of Control of Power Transmission and Conversion Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China

A quasi-linear relationship between voltage angles and voltage magnitudes in power flow calculation is *** accurate estimation of voltage magnitudes can be provided by the quasi-linear relationship when voltage angles are derived by classical DC power *** on the quasi-linear relationship,a novel extended DC power flow(EDCPF)model is proposed considering voltage *** is simple,reliable and accurate for both distribution network and transmission network in normal system operation *** accuracy of EDCPF model is verified through a series of standard test systems.

关键词： DC power flow distribution network transmission network voltage magnitude linear power flow model

Optimal Siting and Sizing of Distributed Renewable Energy in an Active Distribution Network

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CSEE Journal of Power and Energy Systems 2018年第3期4卷 380-387页

作者： Haijun xing Hong Fan xin Sun Shaoyun Hong haozhong Cheng School of Electric Power Engineering Shanghai University of Electric PowerShanghai200090China Construction Branch of State Grid Jiangxi Electric power Co.Ltd. NanchangJiangxi330001China Key Laboratory of Control of Power Transmission and Conversion(SJTU) Ministry of EducationShanghai200240China

The distributed generation (DG) plays an important role in the context of the environmental problems and sustain- able development throughout the world. This paper proposes a DG siting and sizing model in an active distribution network (ADN). The objective is to minimize the total cost, including investment, operation and maintenance costs. The proposed model is transferred to a Mixed Integer Second-Order Cone Programming (MISOCP) model based on a distribution network forward backward-sweep power flow and constraint relaxation. The CVX platform and GUROBI solver are used for the solution. The scenario analysis is used for the uncertainties of load and DG. Different numbers of operational scenarios are considered in order to analyze the effect of a non-network solution to the final planning result and total investment. The planning results with and without consideration of active managements, and the planning results with and without taking environmental profits into consideration, are compared and analyzed. The proposed methodology is verified with a modified IEEE 33 example.

关键词： Active distribution network distributed generation distribution network siting and sizing second-order cone programming

Bibliometric and visual analysis of post-stroke hemiplegia in the past 20 years

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Clinical Research Communications 2024年第3期7卷 29-37页

作者： Jie Li Xue-Min Yin Yong-Fang Yang xin-Ju Li Acupuncture department Tianjin Academy of Traditional Chinese Medicine Affiliated HospitalTianjin 300120China. School of Acupuncture Moxibustion and Tuina Tianjin University of Traditional Chinese MedicineTianjin 301617China. College of Traditional Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjin 301617China.

Objective:The purpose of this study is to use CiteSpace software to examine the development patterns and hotspots in post-stroke hemiplegia research during the last 20 ***:Articles about post-stroke hemiplegia from January 2005 to December 2024 were analyzed in the Web of Science *** software was used to conduct co-citation analysis of the articles about post-stroke hemiplegia as well as cooperative network analyses of authors,countries,and institutions,as well as keyword co-occurrence,clustering,emergence,and time line *** results were displayed in a visual ***:A total of 2625 papers were obtained,and there were more publications *** and the United States had the most number of articles,while Chae,john was the author with the most number of *** Med University and Ohio State University had the most articles among their *** keywords"stroke"and"rehabilitation"were used the *** key word analysis indicates that the present study focus is on exercise rehabilitation measures and post-stroke ***:Using CiteSpace software to analyze the literature on post-stroke hemiplegia,it is discovered that the use of new technologies in the field of mechanical thrombectomy and the effectiveness of rehabilitation techniques like mirror treatment are the key areas of study *** study has positive significance for finding safer and more effective treatments for post-stroke hemiplegia.

关键词： CiteSpace stroke hemiplegia visual analysis

One-dimensional and two-dimensional synergized nanostructures for high-performing energy storage and conversion

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InfoMat 2020年第1期2卷 3-32页

作者： xin Li john Wang Center for Advanced 2D Materials National University of SingaporeSingaporeSingapore Department of Materials Science and Engineering National University of SingaporeSingaporeSingapore

To address the worldwide energy challenges,advanced energy storage and conversion systems with high comprehensive performances,as the promising technologies,are inevitably required on a timely *** performance of these energy systems is intimately dependent on the properties of their *** addition to the electrode materials selection and their compositional optimization,materials fabrication with the designed nanostructure also provides significant benefits for their *** the past decade,considerable efforts have been made to promote the search for multidimensional nanostructures containing both onedimensional(1D)and two-dimensional(2D)nanostructures in synergy,namely,1D-2D synergized *** developing the freestanding electrodes with such unique nanoarchitectures,the structural features and electroactivities of each component can be manifested,where the synergistic properties among them can be simultaneously obtained for further enhanced properties,such as the increased number of active sites,fast electronic/ionic transport,and so *** review overviews the state-of-the-art on the 1D-2D synergized nanostructures,which can be broadly divided into three groups,namely,core/shell,cactus-like,and sandwich-like *** each category,we introduce them from the aspects of structural features,fabrication methodologies to their successful applications in different types of energy storage/conversion devices,including rechargeable batteries,supercapacitors,water splitting,and so ***,the main challenges faced by and perspectives on the 1D-2D synergized nanostructures are discussed.

关键词： 1D-2D synergized nanostructure cactus-like nanostructure core/shell nanostructure energy storage/conversion sandwich-like nanostructure

Generalized Hyers-Ulam Stability of a General Mixed Additive-cubic Functional Equation in Quasi-Banach Spaces

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Acta Mathematica Sinica,English Series 2012年第3期28卷 529-560页

作者： Tian Zhou XU john Michael RASSIAS Wan xin XU School of Mathematics Beijing Institute of Technology Pedagogical Department E.E. Section of Mathematics and InformaticsNational and Capodistrian University of Athens Department of Electrical and Computer Engineering College of EngineeringUniversity of Kentucky

In this paper, we establish a general solution and the generalized Hyers-Ulam-Rassias stability of the following general mixed additive-cubic functional equation

关键词： Stability additive mapping cubic mapping quasi-Banach space p-Banach space

Structural and mechanistic understanding of an active and durable graphene carbocatalyst for reduction of 4-nitrophenol at room temperature

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Nano Research 2015年第12期8卷 3992-4006页

作者： Huawen Hu john H. xin Hong Hu Xiaowen Wang Nanotechnology Centre Institute of Textiles and Clothing The Hong Kong Polytechnic University Hong Kong SAR 999077 China

The development of an active, durable, and metal-free carbocatalyst that is able to replace metal-based catalysts is of increasing scientific and technological importance. The use of such a catalyst would avoid problems caused by metal- containing catalysts, for example, environmental pollution by heavy metals and depletion of rare metal resources. Herein, an active and durable graphene carbocatalyst is presented for the carbocatalytic conversion of 4-nitrophenol to 4-aminophenol at ambient temperature. The carbocatalyst was prepared via a mild, water-based reaction between L-ascorbic acid （AA） and graphene oxide （GO） and did not involve any other reactants. During the structure and catalytic property optimization, a series of carbocatalysts were fabricated at various reaction temperatures and AA/GO ratios. Using several characterization techniques, detailed structural features of these carbocatalysts were identified. Possible active species and sites on the carbocatalysts were also identified such as certain oxygen-containing groups, the ~x-conjugated system, and graphene sheet edges. In addition, the synergistic effect between these active species and sites on the resulting catalytic activity is highlighted. Furthermore, we clarified the origin of the high stability and durability of the optimized carbocatalyst. The work presented here aids the design of high-performance carbocatalysts for hydrogenation reactions, and increases understanding of the structural and mechanistic aspects at the molecular level that lead to high catalyst activity and durability.

关键词： metal-free graphene carbocatalyst activity and durability L-ascorbic acid active sites and domains synergistic effect carbocatalytic conversion of 4-nitrophenol (4NP) to 4-aminophenol (4AP)

Understanding livestock production and sustainability of grassland ecosystems in the Asian Dryland Belt

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Ecological Processes 2017年第1期6卷 225-234页

作者： Jiaguo Qi Xiaoping xin Ranjeet john Pavel Groisman Jiquan Chen Department of Geography Environmentand Spatial Sciences and Center for Global Change and Earth ObservationsMichigan State UniversityEast LansingMIUSA Chinese Academy of Agricultural Sciences BeijingChina University Corp.for Atmospheric Research NOAA National Centers for Environmental Information AshevilleNCUSA Zhejiang University HangzhouChina

Background:Companioned by economic development,a dietary shift toward higher meat consumption is seen in developing countries and transitional economies,where the demand for livestock production has been increasing in response to such a dietary *** the Asian Dryland Belt,approaches to meet this demand have focused on grazing intensification,cropland conversion for animal feed,and supplemental *** the scarcity of water,energy,and food in the region,a key question is whether or not the current approaches are *** not,what are the pathways to increase livestock production while protecting the region’s environment for a sustainable future?We provide our reviews and discuss current approaches in response to these dietary shifts and assess their environmental resilience with a focus on the grassland ecosystems in the Asian Dryland ***:While current approaches alleviate the urgent need for short-term livestock production,they lead to longterm vulnerability in food ***-offs between short gains and long-term losses,between food for humans and for animals,and between agricultural intensification and environmental degradation need to be holistically examined for the sustainable development of the region.A grassland water,energy,and food nexus framework is proposed with specific recommendations to increase livestock production while considering other ecosystem services of the dryland grassland ecosystems in the Asian Dryland ***:Current practices to increase livestock production are likely to lead to long-term,large-scale ecological degradation of the grassland ecosystems in the Asian Dryland Belt and are thus *** considering the trade-offs in the nexus of water,land,food,and livelihoods,sustainable pathways were articulated and *** pilot studies are needed for validation and adoption.

关键词： Dietary shift Livestock production Sustainability Grassland WEF nexus Drylands