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Possible Superconductivity at 37K in Graphite-Sulphur Composite

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Chinese Physics Letters 2001年第12期18卷 1648-1650页

作者： yang hai-peng WEN hai-Hu ZHAO Zhi-Wen LI Shi-Liang ZHAO Zhong-Xian National Laboratory for Superconductivity Institute of Physics and Center for Condensed Matter PhysicsChinese Academy of SciencesP.O.Box 603Beijing 100080

Sulphur intercalated graphite composites with diamagnetic transitions at 6.7 and 37K are prepared. The magnetization hysteresis loops (MHL), x-ray diffraction (XRD) patterns, and resistance have been measured. From the MHL, a slight superconducting-like penetration process is observed at 15K in the low field region. The XRD shows no large difference from the mixture of graphite and sulphur indicating that the volume of the superconducting phase (if any) is very small. The temperature dependence of resistance shows a typical semi-conducting behaviour with a saturation in the low-temperature region. This saturation is either induced by the delocalization of conducting electrons or by possible superconductivity in this system.

关键词： composites saturation conducting

Assessing the influence of the minimum measured diameter on forest spatial patterns and nearest neighborhood relationships

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Journal of Mountain Science 2019年第10期16卷 2308-2319页

作者： LI Yuan-fa yang hai-peng WANG Hong-xiang YE Shao-ming LIU Wen-zhen Guangxi Key Laboratory of Forest Ecology and Conservation College of ForestryGuangxi UniversityNanning 530004China Xiaolongshan Research Institute of Forestry of Gansu Province Gansu Provincial Key Laboratory of Secondary Forest CultivationTianshui 530004China

Forest structure analysis is important for understanding the properties and development of a forest community,and its outcomes can be influenced by how trees are measured in sampled *** there is a general consensus on the height at which tree diameter should be measured[1.3 m:diameter at breast height(DBH)],the minimum measureddiameter(MMD)often varies in different *** this study,we assumed that the outcomes of forest structure analysis can be influenced by MMD and,to this end,we applied g(r)function and stand spatial structural parameters(SSSPs)to investigate how different MMDs affect forest spatial structure analysis in two pine-oak mixed forests(30 and 57 years old)in southwest China and one old-growth oak forest(>120years old)from northwest *** results showed that 1)MMD was closely related to the distribution patterns of forest *** distribution patterns at each observational scale(r=0-20 m)tended tobecome random as the MMD *** older the community,the earlier this random distribution pattern appeared.2)As the MMD increased,neighboring trees became more regularly distributed around a reference *** most cases,however,nearest neighbors of a reference tree were randomly distributed.3)Tree species mingling decreased with increasing diameter,but it decreased slowly in older forests.4)No correlations can be found between individual tree size differentiation and *** recommend that comparisons of spatial structures between communities would be more effective if using a unified MMD criterion.

关键词： Distribution patterns Minimum measured diameter Mixed forest Nearest neighbor analysis Species mingling Uniform angle index

Multiparameter Numerical Investigation of Two Types of Moving Interactions Between the Deep-Sea Mining Vehicle Track Plate and Seabed Soil:Digging and Rotating Motions

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China Ocean Engineering 2024年第3期38卷 408-423页

作者： SUN peng-fei LYU hai-ning yang Jian-min XU Zhi-yong State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Yazhou Bay Institute of Deepsea SCI-TECH Shanghai Jiao Tong UniversitySanya 572024China Institute of Marine Equipment Shanghai Jiao Tong UniversityShanghai 200240China

To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track *** rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed *** this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging ***,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ ***,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil *** results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed ***,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.

关键词： deep-sea mining vehicle rotating motion digging motion track plate-seabed soil interaction CEL numerical method

Strong ferroelectric and luminescence properties of 0-3 type 0.8BaTiO_(3)-0.2CaTiO_(3):Pr^(3+)composite ceramics prepared by cold sintering process

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Journal of Advanced Ceramics 2024年第7期13卷 1002-1010页

作者： Xiaocui Rao Xueling yang Renbing Sun peng Du hai Jiang Yao Huang Laihui Luo Department of Microelectronics Science and Engineering School of Physical Science and TechnologyNingbo UniversityNingbo 315211China College of Materials Science and Engineering Ningbo University of TechnologyNingbo 315016China

0-3 type ferroelectric-phosphor composite ceramics cannot be prepared by the traditional solid-state sintering(SSS)method due to the strong chemical reaction between ferroelectrics and phosphors during high-temperature *** cold sintering process(CSP)may solve this issue by densifying ceramics at ultralow sintering *** this work,dense 0-3 type 0.8BaTiO3-0.2CaTiO3:Pr^(3+)(0.8BT-0.2CT:Pr^(3+))binary composite ceramics were fabricated at an ultralow temperature of 225℃via CSP with the Ba(OH)2·8H2O hydrated *** effects of the Ba(OH)2·8H2O content,sintering temperature,and sintering time on the microstructure and densification of the ceramics were *** density of the composite ceramics prepared by the optimized sintering parameters reaches 89%.Both energy-dispersive X-ray(EDX)spectroscopy and X-ray diffraction(XRD)confirm the existence of BT and CT:Pr^(3+)phases in the prepared ceramics.A strong ferroelectric performance is obtained,and the luminescent properties of CT:Pr^(3+)are preserved for the ***,the 0.8BT-0.2CT:Pr^(3+)composite ceramics prepared by CSP have stronger photoluminescence and photo-stimulated luminescence than their counterparts prepared by cold sintering assistance(CSA)and SSS ***,CSP is a promising method for combining luminescent and ferroelectric properties into 0-3 type composite ceramics.

关键词： single-step densification cold sintering composite ceramics ferroelectric luminescence

Neurophysiological, histological, and behavioral characterization of animal models of distraction spinal cord injury: a systematic review

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Neural Regeneration Research 2024年第3期19卷 563-570页

作者： Bo Han Weishi Liang Yong hai Duan Sun Hongtao Ding Yihan yang peng Yin Department of Orthopedics Beijing Chao-Yang HospitalCapital Medical UniversityBeijingChina

Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal *** the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and *** few studies have been published on the specific characteristics of distraction spinal cord *** this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this *** addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord *** provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.

关键词： animal models behavior distraction heterogeneity histology mechanism neurophysiology spinal cord injury systematic review tension

Towards the insights into the deactivation behavior of acetylene hydrogenation catalyst

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Petroleum Science 2024年第2期21卷 1405-1414页

作者： hai-Xia Su yang Jiao Jian-Gong Shi Zhi-Wei Yuan Di Zhang Xu-peng Wang Jing Ren Dan Liu Jian-Zhou Gui hai-yang Gao Xiao-Li Xu State Key Laboratory of Separation Membranes&Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of Material Science and EngineeringTiangong UniversityTianjin300387China Institute of Engineering Technology Sinopec Catalyst Co.LtdBeijing101100China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of ChemistryTiangong UniversityTianjin300387China

A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;finally, the deactivation behavior of the commercial catalyst for acetylene hydrogenation were studied. The influence of various possible deactivation factors on the catalytic performance was elucidated via detailed structural characterization, surface composition analysis, and activity *** results showed that green oil, carbon deposit and sintering of active metal were the main reasons for deactivation, among which green oil and carbon deposit led to rapid deactivation, while the activity could be recovered after regeneration by high-temperature calcination. The sintering of active metal components was attributed to the high-temperature regeneration in hydrothermal conditions, which was slow but irreversible and accounted for permanent deactivation. Thus, optimizing the regeneration is expected to extend the service life of the commercial catalyst.

关键词： Acetylene Hydrogenation Green oil Carbon deposit Sintering Catalyst deactivation

Strong Quantum Fluctuation of Vortices in Bulk Samples of the New Superconductor MgB_(2)

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Chinese Physics Letters 2001年第6期18卷 816-819页

作者： WEN hai-Hu LI Shi-Liang ZHAO Zhi-Wen NI Yong-Ming REN Zhi-An CHE Guang-Can yang hai-peng LIU Zhi-Yong ZHAO Zhong-Xian National Laboratory for Superconductivity Institute of Physics and Center for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100080

By using transport and magnetic measurement,the upper critical field H_(c2)(T)and the irreversibility line Hirr(T)has been determined.A big separation between H_(c2)(0)and Hirr(0)has been found showing the existence of a quantum vortex liquid state induced by quantum fluctuation of vortices in the new superconductor MgB_(2).Further investigation on the magnetic relaxation shows that both the quantum tunneling and the thermally activated flux creep depends weakly on ***,when the melting field Hirr is approached,a drastic rise of the relaxation rate is *** may indicate that the melting of the vortex matter at a finite temperature is also induced by the quantum fluctuation of vortices.

关键词： temperature. quantum relaxation

Interface optimization of graphene paper-Cu composite prepared by electrodeposition

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Journal of Iron and Steel Research International 2024年第1期31卷 64-73页

作者： Jing Guo hai-jing Wang Shuang-juan Liu peng Zhang Jing-yu Tang Wei-yang Zhang Han-jie Guo peng-cheng Wang Cai Meng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Advanced Technology and Materials Co. Ltd.Beijing100083China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei230027AnhuiChina

A room-temperature electrodeposition method with an organic electrolyte was developed to fabricate a HNO3-pretreated graphene paper Cu(GP'-Cu)*** improve the interfacial bonding of GP'-Cu composite,magnetron sputtering technology was used to create a"sandwich"structural gradient GP'-Cu *** selection of the intermediate transition layer metal was based on two-dimensional *** electron microscopy,X-ray photoelectron spectroscopy,and other analytical methods confirmed that the addition of an intermediate transition metal(Cr,Ni)layer reduced the gap distance and enhanced the interfacial bonding of the GP'and Cu deposited *** GP'-Ni-Cu composite exhibited the largest increase in tensile strength and *** addition,it had the highest thermal diffusivity and elongation at break among the GP'-Cu,GP'-Cr-Cu and GP'-Ni-Cu composites.

关键词： Graphene paper Two-dimensional disregistry Magnetron sputtering Metal composite

MOF glass foam: a blueprint to porous membrane scaling-up

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Science China Chemistry 2024年第3期67卷 746-748页

作者： Yuan peng Weishen yang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

In comparison with conventional energy-intensive separation technologies, such as distillation and crystallization,membrane separation is labelled as an advanced technology with low energy consumption, a small carbon footprint,continuous operation, etc. Metal-organic frameworks(MOFs) are a burgeoning category of crystalline materials consisting of metal ions/clusters coordinated with organic ligands.

关键词： separation porous distillation