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Assessment of International GNSS Service Global Ionosphere Map products over china region based on measurements from the Crustal Movement Observation Network of china

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Earth and Planetary Physics 2024年第2期8卷 400-407页

作者： Jin Hu HaiBing Ruan FuQing Huang shengyang Gu XianKang Dou Institute of Space Weather Nanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Space Weather Chinese Academy of Sciences(CAS)Beijing 100190China School of Electronic Information Wuhan UniversityWuhan 430072China Wuxi Research Institute Nanjing University of Information Science and TechnologyWuxi Jiangsu 214000China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China

The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical *** the credibility of GIM products in data-sparse regions is of paramount *** this study,measurements from the Crustal Movement Observation Network of china(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over china region in *** indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM *** revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:3.%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:3..5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by china’s distinct geomagnetic topology,may manifest as error *** results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across china and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions.

关键词： International GNSS Service(IGS)Global Ionosphere Maps(GIM) Crustal Movement Observation Network of china(CMONOC) total electron content(TEC) data assessment

A New Method for Determining J_(IC) of High StrengthHigh Fracture Toughness Steels by SingleThree Point Bend Specimen

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Journal of Materials science & Technology 1998年第4期14卷 377-379页

作者： Ping GENG M.K.Tseng and Cunfu QIAN (college of science, northeastern university, Shenyang {3., china) college of science Northeastern University Shenyang 110006 China

A single three point bend specimen compliance method for determining JIC of high strength high fracture toughness steels is presented and a formula for calculatinff J-integral is proposed as *** is simple and valid for high strength high fracture toughness steels. The values of JIC and KIC measured by this method are in good agreement with those measured by standard test method.

关键词： of High StrengthHigh Fracture Toughness Steels by SingleThree Point Bend Specimen A New Method for Determining J IC

Performance of composite foundations with different load transfer platforms and substratum stiffness over silty clay

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Journal of Mountain science 2024年第5期21卷 1761-1774页

作者： ZHANG Shuming LIU Yan YUAN shengyang LIU Xianfeng JIANG Guanlu LIU Junyan School of Civil Engineering and Architecture University of JinanJinan 250022China The Engineering Technology Research Center for Urban Underground Engineering Supporting and Risk Monitoring of Shandong Province Jinan 250022China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-speed Railway Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

The semi-rigid pile-supported composite foundation is widely used in highway projects due to its effectiveness in increasing the bearing capacity and stability of *** is crucial to understand the stress distribution across the embankment width and the behaviour of unreinforced ***,five centrifuge tests were conducted to examine the bearing and deformation behaviours of NPRS(Non-Connected Piled Raft Systems)and GRPS(GeosyntheticReinforced Pile-Supported systems)with varying substratum stiffness,then a comparative analysis was conducted on embankment settlement,pressures underneath the embankments,and axial forces along the *** results indicated that greater substratum stiffness correlates with reduced settlement and deformation at various *** occurring 5 meters from the embankment toe includes settlement in NPRS and upward movement in *** potential sliding surface is primarily located within the embankment in NPRS,whereas it may extend through both the embankment and foundation in *** pile-soil stress ratio and efficiency in NPRS are higher than in GRPS across the *** axial force borne by end-bearing piles is significantly greater than that by floating *** the buried depth increases,the axial force in GRPS initially rises then declines,whereas in NPRS,it remains relatively constant within a certain range before *** study aids in assessing the applicability of composite foundations in complex railway environments and provides a reference for procedural measures under similar conditions.

关键词： Centrifuge modelling Composite foundation Failure mode Load transfer platform Substratum Stiffness Silty clay

Acylfluorination of enynes via phosphine and silver catalysis

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Chinese Chemical Letters 2024年第8期35卷 260-264页

作者： Yu Mao Yilin Liu Xiaochen Wang shengyang Ni Yi Pan Yi Wang State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

This work describes intermolecular acylfluorination of gem-difluoroenynes using acyl fluorides as both acyl source and fluorine ***-substituted allenones or furans could be selectively achieved via phosphine and silve... 详细信息

关键词： Phosphine catalysis Silver catalysis Difunctionalization Allenone Furan Trifluoromethyl

Optimizing Domain Distribution of Grain Oriented Silicon Steel by Using Antimony as the Laser Surface Alloying Element

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Journal of Materials science & Technology 2000年第2期16卷 163-164页

作者： Fengjiu SUN, Xingjie PENG and Chuanjun LI (Dept. of Physics, northeastern university, shengyang 110006, china) Dept. of Physics Northeastern University Shengyang 110006 China

For reducing the core loss of grain oriented silicon steel and improving its aging property, a new method, the LLSA by using Sb as the laser surface alloying element, was investigated, and at proper technique conditio... 详细信息

关键词： Optimizing Domain Distribution of Grain Oriented Silicon Steel by Using Antimony as the Laser Surface Alloying Element

Mutual aid instead of mutual restraint:interactive probing for topological charge and phase of a vortex beam of large aberrations

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Photonics Research 2024年第1期12卷 172-182页

作者： shengyang WU BENLI YU LEI ZHANG Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of EducationAnhui UniversityHefei 230601China Information Materials and Intelligent Sensing Laboratory of Anhui Province Anhui UniversityHefei 230601China

An imperfect propagation environment or optical system would introduce wavefront aberrations to vortex *** phase aberrations and orbital angular momentum in a vortex beam are proved to be mutually restrictive in parameter *** make traditional topological charge(TC)probing methods ineffective while the phase singularity makes phase retrieval difficult due to the aliasing between the wrapped phase jump and the vortex phase *** interactive probing method is proposed to make measurements of the aberrated phase and orbital angular momentum in a vortex beam assist rather than hinder each *** phase unwrapping is liberated from the phase singularity by an annular shearing interference technique while the TC value is determined by a Moirétechnique immune to *** and experimental results proving the method effective are *** is of great significance to judge the characteristics of vortex beams passing through nonideal environments and optical systems.

关键词： vortex topological beam

Experimental and numerical investigation of the flexural performance of channel steel-bolt joint for prefabricated subway stations

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 918-935页

作者： Lei WANG shengyang ZHOU Xiangsheng CHEN Xian LIU Shuya LIU Dong SU Shouchao JIANG Qikai ZHU Haoyu YAO college of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Coastal Urban Resilient Infrastructures(MOE) Shenzhen UniversityShenzhen 518061China Shenzhen Key Laboratory of Green Efficient and Intelligent Construction of Underground Metro StationShenzhen UniversityShenzhen 518061China college of Civil Engineering Tongji UniversityShanghai 200092China Shenzhen Municipal Design&Research Co. Ltd.Shenzhen 518029China Shenzhen Metro Group Co. Ltd.Shenzhen 518026China

Flexural performance of joints is critical for prefabricated *** study presents a novel channel steel-bolt(CB)joint for prefabricated subway ***-scale tests are carried out to investigate the flexural behavior of the CB joint under the design loads of the test-case *** addition,a three dimensional(3.)finite element(FE)model of the CB joint is established,incorporating viscous contact to simulate the bonding and detachment behaviors of the interface between channel steel and *** on the 3. FE model,the study examines the flexural bearing mechanism and influencing factors for the flexural performance of the CB *** results indicate that the flexural behavior of the CB joint exhibits significant nonlinear characteristics,which can be divided into four *** illustrate the piecewise linearity of the bending moment-rotational angle curve,a four-stage simplified model is proposed,which is easily applicable in engineering *** study reveals that axial force can enhance the flexural capacity of the CB joint,while the preload of the bolt has a negligible *** flexural capacity of the CB joint is approximate twice the value of the designed bending moment,demonstrating that the joint is suitable for the test-case station.

关键词： channel steel-bolt joint flexural performance full-scale test numerical simulation prefabricated subway station

Dynamic response and failure process of horizontal-layered fractured structure rock slope under strong earthquake

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Journal of Mountain science 2024年第3期21卷 882-900页

作者： WANG Tong LIU Xianfeng HOU Zhaoxu XU Jiahang ZHANG Jun YUAN shengyang JIANG Guanlu HU Jinshan School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-Speed Railway Engineering of Ministry of Education Southwest Jiaotong UniversityChengdu 610031China School of Civil Engineering Xinjiang Institute of EngineeringUrumqi 830023China china Railway First Survey and Design Institute Group Co.LTD Xi'an 710043China

Rock slope with horizontal-layered fractured structure(HLFS)has high stability in its natural ***,a strong earthquake can induce rock fissure expansion,ultimately leading to slope *** this study,the dynamic response,failure mode,and spectral characteristics of rock slope with HLFS under strong earthquake conditions were investigated based on the large-scale shaking table model *** this basis,multiple sets of numerical calculation models were further established by UDEC discrete element *** influencing factors were considered in the parametric study of numerical simulations,including slope height,slope angle,bedding-plane spacing and secondary joint spacing as well as bedrock dip *** results showed that the failure process of rock slope with HLFS under earthquake action is mainly divided into four phases,i.e.,the tensile crack of the slope shoulder joints and shear dislocation at the top bedding plane,the extension of vertical joint cracks and increase of shear displacement,the formation of step-through sliding surfaces and the instability,and finally collapse of fractured rock *** acceleration response of slopes exhibits elevation amplification effect and surface *** simulations indicate that the seismic stability of slopes with HLFS exhibits a negative correlation with slope height and angle,but a positive correlation with bedding-plane spacing,joint spacing,and bedrock dip *** results of this study can provide a reference for seismic stability evaluation of weathered rock slopes.

关键词： Seismic behavior Horizontal layered Weathered rock slope Shaking table test Failure mode

Facile preparation of a SiC@SiO_(2)nanowire-toughened ZrB_(2)-SiC/SiC bilayer coating with good interfacial bonding,high toughness,and excellent cyclic ablation resistance on C/CA composites

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Journal of Advanced Ceramics 2024年第4期13卷 486-495页

作者： Meng Yan Chenglong Hu Jian Li shengyang Pang Bohui Sun Rida Zhao Bin Liang Rui Luo Sufang Tang Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials science and Engineering University of Science and Technology of ChinaShenyang 110016China

Preparing antioxidant coatings to address the inherent oxidation sensitivity of carbon fiber-reinforced carbon aerogel(C/CA)composites is a feasible way to promote their application in oxidizing environments as thermal insulation ***,preparing the coatings with excellent oxidation and ablation resistance while avoiding evident damage to the C/CA substrate still remains a ***,a SiC@SiO_(2)nanowire-toughened ZrB2–SiC/SiC bilayer coating with a large thickness of 500μm was prepared on C/CA using a one-step low-temperature reaction sintering method,which simultaneously formed a sintered outer layer with even-distributed nanowires and a siliconized gradient inner *** courtesy of the synergic thermal response of the layers and the crack deflection induced by the nanowires,the resulting coating has moderate residual compressive stress of 0.08–1.22 GPa in the interface,high interfacial bonding strength of 6.02 MPa,and good fracture toughness of 4.3. MPa·m^(1/2).Benefited from the optimum components and improved structure,the coating shows excellent cyclic ablation resistance with linear ablation rates of 0.1μm/s at 1650℃for 1500 s(3.0 s×5 cycles)and 0.4μm/s at 1850℃for 900 s(3.0 s×3.cycles).The one-step preparation strategy contributes to little damage to the substrate,thus showing the well-preserved mechanical and thermal insulation properties.

关键词： coating carbon fiber reinforced carbon aerogel(C/CA)composites toughness interface residual stress