检索结果-南通市图书馆

Neural Regeneration Research 2010年第17期5卷 1291-1295页

作者： Changsuo Xia Yajuan li wen cao Zhaohua Yu Department of Orthopedics Affiliated Hospital of Qingdao University Medical SchoolQingdao 266003Shandong ProvinceChina

Autologous nerve grafting is the gold standard of peripheral nerve *** previously showed that autologous platelet-rich plasma（PRP）contains high concentrations of growth factors and can induce in vitro cultured bone marrow mesenchymal stem cells（BMSCs）to differentiate into Schwann *** we used PRP-induced BMSCs combined with chemically extracted acellular nerves to repair sciatic nerve defects and compared the effect with autologous nerve *** BMSCs and chemically extracted acellular nerve promoted target muscle wet weight restoration,motor nerve conduction velocity,and axonal and myelin sheath regeneration,with similar effectiveness to autologous nerve *** finding suggests that PRP induced BMSCs can be used to repair peripheral nerve defects.

关键词： bone marrow mesenchymal stem cells platelet-rich plasma peripheral nerve transplantation tissue engineering

Recent advances on the nitrogen-rich 1,2,4-oxadiazole-azoles-based energetic materials

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第3期18卷 344-367页

作者： wen-li cao Qamar-un-Nisa Tariq Zhi-Min li Jun-Qing Yang Jian-Guo Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081 PR China CAS Key Laboratory of Energy Regulation Materials Shanghai200032China

This review covers recent advances in the synthesis and energetic performance of nitrogen-rich 1,2,4-oxadiazole-azoles-based energetic *** materials comprise of 1,2,4-oxadiazole subunit as a key structural motif linked to different nitrogen-rich or nitrogen-oxygen azoles:tetrazole,furazan,furoxan,1,3,4-oxadiazole,pyrazole,and *** attention is devoted to the introduction of various energetic groups including nitro,nitramino,azo,azoxy,dinitromethyl,trinitroethyl moieties,and their *** physicochemical and available performance parameters including density,decomposition temperature,heat of formation,detonation pressure,detonation velocity,impact sensitivity,and friction sensitivity of typical energetic compounds are also provided and ***,it was obtained that several screened compounds exhibit superior detonation properties and outstanding insensitivities,which can be classified as a new family of high-performance energetic ***,1,2,4-oxadiazole-azoles-based energetic materials still have many thorough works to further exploited and studied,expecting to get very promising insensitive high explosives for practical application and industrialization.

关键词： 1,2,4-Oxadiazole-azoles Triazole Tetrazole Furazan Energetic materials Furoxan

Recent advances in the synthesis and energetic properties of potassium-based potential green primary explosives

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第11期18卷 1945-1959页

作者： Qamar-un-Nisa Tariq Saira Manzoor Maher-un-Nisa Tariq wen-li cao Jian-Guo Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Department of Chemistry University of OkaraOkara56300Pakistan

Primary explosives are utilized as a reliable initiator for secondary explosives in an extensive range of military and civilian operations. Heavy-metal-based primary explosives are moderate performing, more sensitive, and environmentally hazardous, posing a direct and indirect threat to health and ***, heavy-metal-based primaries have been replaced by environment-friendly metal-based primary explosives, such as potassium complexes. This review presents not only a summary of the current progress of new-generation potassium-based primary explosives and their methods of preparation, energetic properties, and applications, but also a further comparison with traditional primary explosives. In addition, this work discusses the necessity of heavy metal-free primary explosives and the major challenges faced in replacing traditional primary explosives.

关键词： Green primary explosives Heterocyclic compounds Synthesis Energetic properties

Effect of TiO_(2) addition on microstructures and properties of Mgo-cao refractory aggregates

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1547-1554页

作者： Shuai Zhang Jing-ran Wang Yuan-gao li Feng-you li wen Yan Hui-ying Shi The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Joint International Research Laboratory of Refractories and Metallurgy Wuhan 430081HubeiChina Shanxi Luweibao Taigang Refractory Co. Ltd.Taiyuan 030003ShanxiChina

MgO-cao(40 wt.%cao)refractory aggregates were prepared using the calcined dolomite and light-burned magnesia fine powder as raw materials and TiO_(2) as *** effect of TiO_(2) on their phase composition,microstructures and properties was investigated by X-ray diffraction and scanning electron *** properties such as bulk density,apparent porosity,relative aggregate tube strength and hydration resistance were also *** results showed that the CaTiO_(3) generated by the reaction between cao and TiO_(2) was distributed around the cao grain boundaries and intermittently distributed with MgO,which formed an isolation layer around cao and greatly improved the hydration ***,the introduction of TiO_(2) promoted sintering and increased the grain size,further improving the strengths and hydration resistance of the *** addition,the most significant enhancement in the hydration resistance and strengths of the samples was achieved when 1.0-2.0 wt.%TiO_(2) was *** this case,the relative strength of aggregate increased from 33.3% to 37.3%-43.1%,and the mass gain after the hydration test decreased from 3.13% to 1.26%-1.45%.

关键词： MgO-cao refractory aggregate TiO_(2)addition Phase composition Microstructure Hydration resistance

Dynamic response mechanism and precursor characteristics of gneiss rockburst under different initial burial depths

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第3期21卷 1004-1018页

作者： liU Dongqiao SUN Jie MENG wen HE Manchao ZHANG Chongyuan li Ran cao Binghao State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing 100083China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China

To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real *** experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial *** then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of ***’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack ***,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor.

关键词： Traffic Engineering Gneiss Rockburst Crack propagation Excess energy Precursor characteristic

Fixed-Time Gradient Flows for Solving Constrained Optimization: A Unified Approach

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1849-1864页

作者： Xinli Shi Xiangping Xu Guanghui wen Jinde cao School of Cyber Science and Engineering Southeast UniversityNanjing 210096China School of Mathematics Southeast UniversityNanjing 210096China

The accelerated method in solving optimization problems has always been an absorbing *** on the fixedtime(FxT)stability of nonlinear dynamical systems,we provide a unified approach for designing FxT gradient flows(FxTGFs).First,a general class of nonlinear functions in designing FxTGFs is provided.A unified method for designing first-order FxTGFs is shown under Polyak-Łjasiewicz inequality assumption,a weaker condition than strong *** there exist both bounded and vanishing disturbances in the gradient flow,a specific class of nonsmooth robust FxTGFs with disturbance rejection is *** the strict convexity assumption,Newton-based FxTGFs is given and further extended to solve time-varying ***,the proposed FxTGFs are further used for solving equation-constrained ***,an FxT proximal gradient flow with a wide range of parameters is provided for solving nonsmooth composite *** show the effectiveness of various FxTGFs,the static regret analyses for several typical FxTGFs are also provided in ***,the proposed FxTGFs are applied to solve two network problems,i.e.,the network consensus problem and solving a system linear equations,respectively,from the perspective of ***,by choosing component-wisely sign-preserving functions,these problems can be solved in a distributed way,which extends the existing *** accelerated convergence and robustness of the proposed FxTGFs are validated in several numerical examples stemming from practical applications.

关键词： Consensus constrained optimization disturbance rejection linear equations fixed-time gradient flow(FxTGF).

Experimental study on the effect of unloading rate on gneiss rockburst

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2064-2076页

作者： Dongqiao liu Jie Sun Ran li Manchao He Binghao cao Chongyuan Zhang wen Meng State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing100083China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China

Rockburst are often encountered in tunnel construction due to the complex geological *** study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in *** results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection *** mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of *** makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack ***,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation *** enlightenments of reducing the unloading rate for the project are also described *** rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.

关键词： Rockburst Unloading rate Crack propagation Influence mechanisms

Vibration-Based Fault Diagnosis for Railway Point Machines Using VMD and Multiscale Fluctuation-Based Dispersion Entropy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第3期33卷 803-813页

作者： Yongkui SUN Yuan cao Peng li Guo XIE Tao wen Shuai SU National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University School of Electronic and Information Engineering Beijing Jiaotong University Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an University of Technology Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University

As one of the most important railway signaling equipment,railway point machines undertake the major task of ensuring train operation *** fault diagnosis for railway point machines becomes a hot *** the advantage of the anti-interference characteristics of vibration signals,this paper proposes an novel intelligent fault diagnosis method for railway point machines based on vibration signals.A feature extraction method combining variational mode decomposition(VMD) and multiscale fluctuation-based dispersion entropy is developed,which is verified a more effective tool for feature ***,a two-stage feature selection method based on Fisher discrimination and ReliefF is proposed,which is validated more powerful than single feature selection ***,support vector machine is utilized for fault *** comparisons show that the proposed method performs *** diagnosis accuracies of normal-reverse and reverse-normal switching processes reach 100% and 96.57% ***,it is a try to use new means for fault diagnosis on railway point machines,which can also provide references for similar fields.

关键词： Fault diagnosis Vibrations Support vector machines Diversity reception Switches Feature extraction Rail transportation

Orientation controlled photogenerated carriers on selfsupporting CdS/Ni_(3)S_(2) paper toward photocatalytic hydrogen evolution and biomass upgrading

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2015-2025页

作者： Xiao-Yan liu Qing cao Gui-Xiang li Hui liu li-li Zeng li-li Zhao Bin Chang Xi-wen Wang Hong liu Wei-Jia Zhou Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China Institute of Chemical Sciences and Engineering Ecole Polytechnique Federale de Lausanne1015LausanneSwitzerland KAUST Catalysis Center King Abdullah University of Science and TechnologyThuwal 23955-6900Kingdom of Saudi Arabia School of Environment and Energy South China University of TechnologyGuangzhou Higher Education Mega CenterGuangzhou 510006China State Key Laboratory of Crystal Materials Shandong UniversityJinan250100China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710054China

The appropriate regulation of band structure is an effective strategy in constructing efficient photocatalytic *** photocatalytic system mainly employs powder photocatalysts,which makes their recovery reliant on expensive separation processes and severely limits their industrial ***,we constructed a novel CdS/Ni_(3)S_(2)heterostructure using free-standing and flexible nickel fiber paper as the *** regulated energy band structure achieves effective electron–hole *** as-synthesized flexible photocatalyst exhibits considerable photocatalytic activity toward the H_(2)evolution reaction under visible-light irradiation,with an H_(2)production rate of5.63μmol·cm^(-2)·h^(-1)(14.1 mmol·g^(-1)cat·h^(-1)according to the catalyst loading content).Additionally,the otherwisewasted excited holes simultaneously drive organic transformations to yield value-added organic products,thus markedly improving the photocatalytic H_(2)evolution *** a photocatalytic system is scaled up further,where a self-supported 20 cm×25 cm sample achieves a champion H_(2)production rate of 60-80μmol·h^(-1)under practical sun *** newly developed self-supported photocatalyst produces opportunities for practical solar H2production with biomass upgrading.

关键词： Self-supporting photocatalyst CdS/Ni_(3)S_(2) heterojunction Hydrogen evolution Biomass upgrading Large-scaleapplication

A small-scale experimental study of CO_(2) enhanced injectivity methods of the high-rank coal

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2021年第5期18卷 1427-1440页

作者： Qing-He Niu li-wen cao Shu-Xun Sang Wei Wang Wei Yuan Jiang-Fang Chang Xiao-Jun Jia Wei-Min Zheng Zeng-Xue Zhang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China Hebei Technology and Innovation Center on Safe and Efficient Mining of Metal Mines Shijiazhuang050043China School of Resource and Earth Science China University of Mining and TechnologyXuzhou221008China Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhou221008China Hebei Academy of Emergency Management Shijiazhuang050081China Hebei Iron and Steel Group Mining Co. LtdTangshan063000China Minmetals Mining Holding Co. LtdHefei241000China

The attenuation of CO_(2)injectivity has become the biggest technical barrier for the application of CO_(2)enhanced coalbed methane recovery(CO_(2)-ECBM).Commonly,the intermittent CO_(2)injection,N2 displacing CO_(2)and pre-fracturing are the potential CO_(2)enhanced injectivity methods for coal reservoirs,but their mechanism and effectiveness remain to be *** paper thus conducted small-scale experiments to simulate the working process of these engineering measures by an independently developed experimental *** show that the CO_(2)injectivity of coal is remarkably improved by the intermittent injection mode since the CO_(2)injection time is increased by folds and the loss of reservoir pressure can be complemented in *** N_(2)displacing CO_(2)method promotes the desorption of CO_(2)and reduces the swelling strain,with the result that the permeability of coal is improved by 74.82%and 64.95%compared with the methods of the primary subcritical CO_(2)(Sub CO_(2))and supercritical CO_(2)(Sc CO_(2))***,the permeability reduces again with the secondary CO_(2)*** permeability of the coal sample after pre-fracturing is averagely improved by 1-2 orders of magnitude,the irreversible permeability loss rate,average stress sensitivity coefficient and the permeability loss rate due to adsorption are averagely reduced by 95.885%,61.538%and 96.297%,*** indicates that the permeability of coal after pre-fracturing is no longer sensitive to both the effective stress and Sc CO_(2)adsorption,the injectivity is thus improved and *** CO_(2)enhanced injectivity effects of the intermittent CO_(2)injection,the N_(2)displacing CO_(2)and the pre-fracturing are various,which thus can be selected individually or jointly to improve the CO_(2)injectivity according to the reservoir physical properties and geological *** research deepens the understanding of the functional mechanism of CO_(2)enhanced injectivity method

关键词： Supercritical CO_(2) Permeability Intermittent injection N_(2)displacing CO_(2) Pre-fracturing