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Rock strength interval analysis using theory of testing blind data and interval estimation

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Journal of Central South University 2017年第1期24卷 168-177页

作者：田森陈建宏董陇军 State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Environmental Science Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Central South UniversityChangsha 410083China

The concepts of rock strength intervals are presented in this work, furthermore, central values of intervals and their corresponding credibility are provided using two-case study based on blind data theory and fuzzy interval estimation. 60 granite specimens are first tested, the compressive strength interval and tensile strength interval are [ 103.68, 219.6 l ] and [7.53, 11,86] MPa, while the tested mean values of compressive strength and tensile strength are 152.86 and 10.14 MPa, the credibilities are less than 58.4% and around 70.4%, respectively, the credibility of shear strength is between 40% and 60%. Then 70 other rock specimens are designed and tested, the similar conclusions can be reached. The results show that the conventional definite values are the particular values within the intervals, and the credibility of them often fails to reach the high-precision engineering requirement. The results demonstrate the feasibility and application potential of this proposed algorithm for the engineering practice. The references for engineering value selection of rock strength under different credibility or according to frequency distribution of central values are provided to increase the reliability and precision of calculation.

关键词： rock strength interval uniaxial compressive strength uniaxial tensile strength shear strength blind data interval theory

Mechanical properties and microstructure of Mg-treated and Catreated industrial H13 steel after quenching and tempering

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Journal of Iron and Steel Research International 2024年第8期31卷 1987-2001页

作者： jun-ying Yue dong Hou De-yong Wang Tian-peng Qu Xiang-long Li jun Tian School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

The effect of magnesium treatment and calcium treatment on the microstructure and mechanical properties of industrial H13 steel after quenching and tempering was *** impact toughness and tensile tests were mainly carried out,and the microstructure was observed by scanning electron microscopy,electron backscattered diffraction,and X-ray *** results show that magnesium treatment is still feasible in industrial *** is mainly manifested in the refinement of lath martensite and *** with calcium treatment,the prior austenite grains and carbides size of industrial H13 steel treated with magnesium decreased by 3.17μm after *** quenching and tempering,the carbides(especially V-rich carbides)in Mg treatment obviously spheroidized and distributed uniformly and increased in quantity *** lath martensite size is reduced from 2.45 to 2.31μ*** suggests that magnesium treatment was able to yield smaller grains and more evenly distributed ***,the impact toughness,yield strength,and ultimate tensile strength of industrial H13 steel with magnesium treatment increased by 28%,65.5 MPa and 123.7 MPa,*** increment of strength mainly comes from dislocation strengthening,grain refinement strengthening,and precipitation strengthening,among which precipitation strengthening accounts for the largest proportion.

关键词： Industrial H13 steel Mg treatment Heat treatment Carbide-Mechanical property

The diagnostic value of tenascin-C in acute aortic syndrome

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Journal of Geriatric Cardiology 2024年第3期21卷 359-368页

作者： Ming MA Wei CHEN Hai-long CAO jun PAN Qing ZHOU Xin-long TANG dong-Jin WANG Department of Thoracic and Cardiovascular Surgery Nanjing Drum Tower Hospital Clinical College of Nanjing Medical UniversityNanjingChina Department of Thoracic and Cardiovascular Surgery Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingChina Department of Thoracic surgery Kunshan Hospital of Traditional Chinese MedicineJiangsuChina

OBJECTIVES Misdiagnosis of acute aortic syndrome(AAS)significantly increases ***-C(TN-C)is an extracellular matrix glycoprotein related to cardiovascular *** elevation of TN-C in AAS and whether it can discriminate suddenonset of acute chest pain in Chinese remains *** We measured the plasma concentration of TN-C by ELISA in a cohort of 376 patients with chest or back *** to discriminate AAS from acute coronary syndrome(ACS)were compared and *** From October 2016 to September 2021,376 undiagnosed patients with chest or back pain were enrolled.166 of them were finally diagnosed as AAS,100 were ACS and 110 without cardiovascular diseases(NCV).TN-C was significantly elevated in AAS at 18.18 ng/mL(IQR:13.10–27.68)compared with 7.51 ng/mL(IQR:5.67–11.38)in ACS(P<0.001)and 3.68 ng/mL(IQR:2.50–5.29)in NCV(P<0.001).There was no significant difference in TN-C level among the subtypes of *** the 166 AAS patients,the peaked level of TN-C was at acute stage(P=0.012),then a slight of decrease was observed at subacute *** area under receiver operating characteristic curve for AAS patients versus NCV was 0.979(95%CI:0.964-0.994)for *** a cutoff level of 11.474 ng/mL,TN-C has a sensitivity of 76.0%,specificity of 85.5%,accuracy of 82.0%,positive predictive value(PPV)of 76.0%,negative predictive value(NPV)of 85.5%.Diagnostic performance of TN-C was superior to D-dimer and *** The concentration of serum TN-C in AAS patients was significantly higher than that in ACS patients and ***-C could be a new biomarker to distinguish AAS patients in the early stage after symptoms onset from other pain diseases.

关键词： acute cardiovascular elevated

Effect of multiple coulomb scattering on the beam tests of silicon pixel detectors

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Nuclear Science and Techniques 2024年第4期35卷 200-207页

作者： Lan-Kun Li Ming-Yi dong Ze Gao Liang-Cheng-long Jin Shu-jun Zhao School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Particle Detection and Electronics(Institute of High Energy Physics CAS)Beijing 100049China University of Chinese Academy of Science Beijing 100049China University of South China Hengyang 421001China

In the research and development of new silicon pixel detectors,a collimated monoenergetic charged-particle test beam equipped with a high-resolution pixel-beam telescope is crucial for prototype verification and performance *** the beam energy is low,the effect of multiple Coulomb scattering on the measured resolution of the Device Under Test(DUT)must be considered to accurately evaluate the performance of the pixel chips and *** study aimed to investigate the effect of multiple Coulomb scattering on the measured resolution,particularly at low beam *** were conducted using Allpix^(2) to study the effects of multiple Coulomb scattering under different beam energies,material budgets,and telescope *** simulations also provided the minimum energy at which the effect of multiple Coulomb scattering could be *** with the results of a five-layer detector system tested with an electron beam at DESY,the simulation results were consistent with the beam test results,confirming the reliability of the simulations.

关键词： Silicon Pixel Detectors Beam Telescope Multiple Coulomb Scattering Spatial Resolution

Three-dimensional analytical solution of acoustic emission or microseismic source location under cube monitoring network

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Transactions of Nonferrous Metals Society of China 2012年第12期22卷 3087-3094页

作者：董陇军李夕兵中南大学资源与安全工程学院长沙410083

To find the analytical solution of the acoustic emission/microseismic(AE/MS) source location coordinates, the sensor location coordinates were optimized and simplified. A cube monitoring network of sensor location was selected, and the AE/MS source localization equations were established. A location method with P-wave velocity by analytical solutions (P-VAS) was obtained with these equations. The virtual location tests show that the relocation results of analytical method are fully consistent with the actual coordinates for events both inside and outside the monitoring network; whereas the location error of traditional time difference method is between 0.01 and 0.03 m for events inside the sensor array, and the location errors are larger, which is up to 1080986 m for events outside the sensor array. The broken pencil location tests were carried out in the cross section of 100 mm×98 mm, 350 mm-length granite rock specimen using five AE sensors. Five AE sources were relocated with the conventional method and the P-VAS method. For the four events outside monitoring network, the positioning accuracy by P-VAS method is higher than that by the traditional method, and the location accuracy of the larger one can be increased by 17.61 mm. The results of both virtual and broken pencil location tests show that the proposed analytical solution is effective to improve the positioning accuracy. It can locate the coordinates of AE/MS source only using simple four arithmetic operations, without determining the fitting initial value and iterative calculation, which can be solved by a conventional calculator or Microsoft Excel.

关键词： acoustic emission seismic source sensor location analytical solution

Carbon nanofibers embedded with Fe-Co alloy nanoparticles via electrospinning as lightweight high-performance electromagnetic wave absorbers

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Rare Metals 2024年第6期43卷 2769-2783页

作者： Wen-jun Cai Jian-Guo Jiang Zi-dong Zhang Zi-Xuan Liu Lu-JieZhang Zhen-Kun long Ke Bi Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China Energy Institute Qilu University of Technology(Shandong Academy of Sciences)Jinan 250014China State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China

As a lot of electromagnetic pollution and interference issues have emerged,to overcome electromagnetic interference,prevent electromagnetic hazards,and develop new high-performance electromagnetic wave(EMW)absorbers have become a significant task in the field of materials *** this paper,a three-dimensional(3D)carbon nanofibers network with core-shell structure,embedded with varied molar ratios of iron and cobalt(4:0,3:1,2:2,1:3,0:4),was effectively synthesized(Fe/Co@C-CNFs)via *** phase,microstructure,magnetic and EMW absorption properties were *** is discovered that Fe/Co@C-CNFs doped with iron:cobalt=1:1 have excellent EMW absorption *** the matching thickness is 1.08 mm,the minimum reflection loss(RL)value is-18.66 dB,while the maximum effective absorption bandwidth(EAB)reaches 4.2 GHz(13.9-18 GHz)at a thickness of 1.22 *** is owing to the absorbers'superior impedance matching and multiple reflections as well as the conductivity,dielectric,and magnetic losses of carbon nanofibers embedded with Fe-Co alloy *** addition,the radar cross section(RCS)of the absorbers has been calculated by CST Studio Suite,showing that the absorbing coating can effectively reduce the RCS at various angles,especially for Fe/Co@C-CNFs doped with iron:cobalt=1:*** findings not only provide new insights for the preparation of light-weight and high-performance electromagnetic wave absorbers,but also contribute to energy storage and conversion.

关键词： Electromagnetic wave(EMW)absorbers Fe/Co@C-CNFs Core-shell structure EMW absorbing mechanism Radar cross section(RCS)

Preparation of entangledW states based on the cavity QED system

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Chinese Physics B 2024年第9期33卷 290-296页

作者： Ke Li jun-long Zhao Department of Physics Shanghai Second Polytechnic UniversityShanghai 201209China Quantum Information Research Center Shangrao Normal UniversityShangrao 334001China

We present a qubit-loss-free(QLF)fusion scheme for generating large-scale atom W states in cavity quantum electrodynamics(QED)*** to the most current fusion schemes which are conditioned on the case where one particle can be extracted from each initial W state to the fusion process,our scheme will access one or two particles from each W *** on the atom–cavity-field detuned interaction,three jWin+m+t states can be generated from the jWin,jWim,and jWit states with the help of two auxiliary atoms,and three jWin+m+t+q states can be generated from jWin,jWim,jWit,and a jWiq state with the help of three auxiliary *** the numerical simulations of the resource cost of fusing three small-size W states based on the previous schemes,our fusion scheme seems to be more *** QLF fusion scheme can be generalized to the case of fusing k different or identical particle W ***,with no qubit loss,it greatly reduces the number of fusion steps and prepares W states with larger particle numbers.

关键词： W state detuned interaction state fusion cavity quantum electrodynamics

Could π-aromaticity cross an unsaturated system to a fully saturated one?

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Chinese Chemical Letters 2024年第6期35卷 298-302页

作者： Shicheng dong jun Zhu State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChem)Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China School of Science and Engineering The Chinese University of Hong KongShenzhen 518172China

The classification of π-/σ-aromaticity depends on the electrons with the dominating ***,π-andσ-aromaticity are used to describe the unsaturated and saturated systems,***,it is rarely reported that π-aromaticity is dominated in a saturated *** we demonstrate that π-aromaticity could be dominating in several fully saturated four-membered rings(4MRs),supported by various aromaticity indices including ΔBL,NICS,EDDB,MCI,and Ad *** origin of suchπ-aromaticity in saturated rings could be attributed to an introduction of two additional electrons into the π-type LUMO of the parent neutral *** findings represent a novel approach to achieve π-aromaticity into a fully saturated system which has traditionally been dominated by σ-aromaticity.

关键词： π-Aromaticity Saturated rings Silicon

Phase behavior of gas condensate in porous media using real-time computed tomography scanning

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Petroleum Science 2024年第2期21卷 1032-1043页

作者： Wen-long Jing Lei Zhang Ai-Fen Li jun-Jie Zhong Hai Sun Yong-Fei Yang Yu-long Cheng jun Yao Institute of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina

The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir *** was used as a sample to investigate the influence of porous media on the phase behavior of the gas *** pore structure was first analyzed using computed tomography(CT)scanning,digital core technology,and a pore network *** sandstone core sample was then saturated with gas condensate for the pressure depletion *** each pressure-depletion state was stable,realtime CT scanning was performed on the *** scanning results of the sample were reconstructed into three-dimensional grayscale images,and the gas condensate and condensate liquid were segmented based on gray value discrepancy to dynamically characterize the phase behavior of the gas condensate in porous *** network models of the condensate liquid ganglia under different pressures were built to calculate the characteristic parameters,including the average radius,coordination number,and tortuosity,and to analyze the changing mechanism caused by the phase behavior change of the gas *** types of condensate liquid(clustered,branched,membranous,and droplet ganglia)were then classified by shape factor and Euler number to investigate their morphological changes dynamically and *** results show that the dew point pressure of the gas condensate in porous media is 12.7 MPa,which is 0.7 MPa higher than 12.0 MPa in PVT *** average radius,volume,and coordination number of the condensate liquid ganglia increased when the system pressure was between the dew point pressure(12.7 MPa)and the pressure for the maximum liquid dropout,Pmax(10.0 MPa),and decreased when it was below *** volume proportion of clustered ganglia was the highest,followed by branched,membranous,and droplet *** study provides crucial experimental evidence for the phase behavior chan

关键词： Gas condensate Pressure depletion Real-time micro-computed tomography scanning Distribution of condensate liquid