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Assessment of rockburst hazard by quantifying the consequence with plastic strain work and released energy in numerical models

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International Journal of Mining Science and Technology 2019年第1期29卷 93-97页

作者： f.wang R.kaunda Mining Engineering Department Colorado School of Mines

Quantifying the rockburst consequence is of critical importance to reduce the hazards with preventative measures in underground mines and deep tunnels. Contours of energy components within a pillar model are plotted at different rockmass damage stages, and plastic strain work and released energy are proposed as indicators of rockmass damage consequence. One pillar model under different loading stiffness is simulated to assess indicators of pillar burst and the resulting damages. The results show the rockmass damage under soft loading stiffness has larger magnitude of plastic strain work and released energy than that which is under stiff loading stiffness, indicating the rockburst consequence can be quantified with plastic strain work and released energy in numerical models. With the quantified rockburst consequence,preventative measures can be taken to avoid severe hazards to mine safety.

关键词： Unstable rock failure Rock burst Energy mechanism Numerical modeling Released energy

Teleportation of unknown states of a qubit and a single-mode field in strong coupling regime without Bell-state measurement

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Communications in Theoretical Physics 2023年第2期75卷 73-79页

作者： f Jahanbakhsh M k Tavassoly Optics and Laser Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran

In this paper,we develop the teleportation scheme in[Zheng in Phys Rev A 69,064302,2004],in the sense that,we work in the strong atom-field coupling regime wherein the rotating wave approximation(RWA)is no longer *** achieve the purpose,a scheme consisting of a qubit interacting with a single-mode quantized field is described via the Rabi model(counter rotation terms are taken into account).Our first aim is to teleport an unknown atomic state of a qubit(which interacts with the quantized field in a cavity)to a second qubit(exists in another distant cavity field),beyond the RWA and without the Bell-state measurement *** the continuation,in a similar way,we teleport an unknown state of a single-mode field *** fact,it is shown that,in this regime,after applying some particular conditions,containing the interaction time of atom-field in the cavities,adjusting the involved frequencies,as well as the atom-field coupling in the model,if a proper measurement is performed on the state of the first qubit(the related field in the cavity),the unknown states of the qubit(field)can be teleported from the first qubit(cavity field)to the second qubit(cavity field),*** show that in both considered cases,the teleportation protocol is successfully performed with the maximum possible fidelity,1,and the acceptable success probability,0.25.

关键词： strong atom-field coupling Rabi model quantum teleportation success probability fidelity

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新质生产力、双循环联动与共同富裕

华东经济管理 2025年第1期39卷 10-20页

作者：王江吉林农业大学马克思主义学院吉林长春130118 东北师范大学思想政治教育研究中心吉林长春130024

文章以2012—2022年为考察区间,选取我国276个地级及以上城市面板数据,就新质生产力对共同富裕的影响效应与作用机制展开研究。基准回归结果发现,新质生产力可显著推动共同富裕;异质性分析显示,新质生产力对共同富裕的影响效应具有城市... 详细信息

文章以2012—2022年为考察区间,选取我国276个地级及以上城市面板数据,就新质生产力对共同富裕的影响效应与作用机制展开研究。基准回归结果发现,新质生产力可显著推动共同富裕;异质性分析显示,新质生产力对共同富裕的影响效应具有城市规模异质性和分时段异质性;中介效应检验表明,国内循环、国际循环以及双循环联动在新质生产力与共同富裕之间发挥中介效应;门槛效应结果证实,随着数字金融水平不断提升,新质生产力对共同富裕的影响效应持续扩大。研究结论有利于进一步发挥新质生产力“助推器”作用,为实现共同富裕目标提供有益借鉴。

关键词：共同富裕新质生产力双循环联动数字金融新发展格局

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friction and wear behaviors of a gradient nano-grained AISI 316L stainless steel under dry and oil-lubricated conditions

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Journal of Materials Science & Technology 2018年第10期34卷 1835-1842页

作者： P.f. wang Z. Han Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China University of Chinese Academy of Sciences Beijing 100049 China

A gradient nano-grained （GNG） surface layer was fabricated on an AIS1316L stainless steel （SS） by using the surface mechanical rolling treatment （SMRT）. Reciprocating dry and oil-lubricated sliding tests of the GNG 316L SS in air at room temperature were conducted in comparison with the coarse-grained （CG） counterpart. Worn surface morphologies and subsurface microstructures were investigated for both 316L SS samples. 316L SS with a GNG surface layer shows a significantly improved wear resistance, especially under oil-lubricated condition. The notably wear resistance enhancement of the GNG 316L SS is attributed to the GNG surface layer with high strain accommodation ability and high hardness, which can reduce the wear volume in the running-in stage effectively.

关键词： Austenitic stainless steel Gradient nano-grained surface layer friction and wear Running-in

Modification Design Method for an Enveloping Hourglass Worm Gear with Consideration of Machining and Misalignment Errors

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Chinese Journal of Mechanical Engineering 2013年第5期26卷 948-956页

作者： DENG Xingqiao wang Jinge HORSTEMEYER Mark f School of Mechanical Engineering and Automation Xihua University Center for Advanced Vehicular Systems Mississippi State University

The influences of machining and misalignment errors play a very critical role in the performance of the anti-backlash double-roller enveloping hourglass worm gear(ADEHWG).However,a corresponding efficient method for eliminating or reducing these errors on the tooth profile of the ADEHWG is seldom *** gear engagement equation and tooth profile equation for considering six different errors that could arise from the machining and gear misalignment are derived from the theories of differential geometry and gear ***,the tooth contact analysis(TCA) is used to systematically investigate the influence of the machining and misalignment errors on the contact curves and the tooth profile by means of numerical analysis and three-dimensional solid *** research results show that vertical angular misalignment of the worm wheel(Δβ) has the strongest influences while the tooth angle error(Δα) has the weakest influences on the contact curves and the tooth profile.A novel efficient approach is proposed and used to minimize the effect of the errors in manufacturing by changing the radius of the grinding wheel and the approaching point of *** results from the TCA and the experiment demonstrate that this tooth profile design modification method can indeed reduce the machining and misalignment *** modification design method is helpful in understanding the manufacturing technology of the ADEHWG.

关键词： worm gears tooth contact analysis machining and misalignment errors tooth profile errors modification method

Synthesis and Crystal Structure of a New Potassium Yttrium Diphosphate Dihydrate kYP_2O_7·2H_2O

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Chinese Journal of Structural Chemistry 2008年第10期27卷 1199-1204页

作者： férid M Horchani-Naifer k Unité de Recherches de Matériaux de Terres Rares Centre National de Recherches en Sciences des MatériauxB.P.95 Hammam-Lif 2050Tunisie

The dihydrated potassium yttrium diphosphate, kYP2O7·2H2O, has been synthesized for the first time. Single-crystal XRD study has allowed the determination of its structure and correct formula. It crystallizes in the monoclinic system, space group P21/c, with the cell parameters a = 7.7069（3）, b = 10.5801（4）, c = 10.0204（5）A,β = 93.24（3）A, V= 815.76（6）A^3, Z= 4, Mr = 337.98, f（000） = 656, Dc = 2.752 g/cm^3 and/t = 8.073 mm^-1. The single-crystal structure was solved from 1856 unique reflections with the final R = 0.0365 and wR = 0.0772, refined with 119 parameters. The atomic arrangement of kYP2O7·2H2O is built by the P2O7 groups, the YO7 and the kO10 polyhedrons which are connected by corner and edge-sharing to form a three-dimensional framework. Water molecules are directly bonded to the Y and k atoms, and they are located in channels running along the a direction.

关键词： crystal structure yttrium diphosphate infrared spectrum TGA-DTA analysis

风洞模拟建筑物对大气污染物扩散影响的若干问题讨论

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实验流体力学 2006年第3期20卷 63-70页

作者：汪新 McNamara k f 广东工业大学建设学院广州510090 爱尔兰国立大学土木工程系

通过相似性分析,得到了大气污染建筑物影响风洞试验应满足的基本相似条件。由一个实例研究了利用常规风洞模拟装置和测试仪器进行大气污染建筑物影响风洞试验在技术上的可行性。结果显示:由于模拟装置和仪器条件的限制,在大多数风洞试... 详细信息

通过相似性分析,得到了大气污染建筑物影响风洞试验应满足的基本相似条件。由一个实例研究了利用常规风洞模拟装置和测试仪器进行大气污染建筑物影响风洞试验在技术上的可行性。结果显示:由于模拟装置和仪器条件的限制,在大多数风洞试验中存在大气边界层不完全模拟和仪器响应过慢等问题,但通过合理模拟来流的主要湍流特征和改进采样方法,可以在风洞中较真实地模拟建筑物对大气扩散的影响。

关键词：空气污染扩散风洞试验建筑物影响

Momentum and heat transfer of a special case of the unsteady stagnation-point flow

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Applied Mathematics and Mechanics(English Edition) 2020年第1期41卷 51-82页

作者： T.G.fANG f.J.wang Mechanical and Aerospace Engineering Department North Carolina State University

This paper investigates the unsteady stagnation-point flow and heat transfer over a moving plate with mass transfer,which is also an exact solution to the unsteady Navier-Stokes(NS)*** boundary layer energy equation is solved with the closed form solutions for prescribed wall temperature and prescribed wall heat flux *** wall temperature and heat flux have power dependence on both time and spatial *** solution domain,the velocity distribution,the flow field,and the temperature distribution in the fluids are studied for different controlling *** parameters include the Prandtl number,the mass transfer parameter at the wall,the wall moving parameter,the time power index,and the spatial power *** is found that two solution branches exist for certain combinations of the controlling parameters for the flow and heat transfer *** heat transfer solutions are given by the confluent hypergeometric function of the first kind,which can be simplified into the incomplete gamma functions for special *** wall heat flux and temperature profiles show very complicated variation *** wall heat flux can have multiple poles under certain given controlling parameters,and the temperature can have significant oscillations with overshoot and negative values in the boundary *** relationship between the number of poles in the wall heat flux and the number of zero-crossing points is *** difference in the results of the prescribed wall temperature case and the prescribed wall heat flux case is *** given in this paper provide a rare closed form analytical solution to the entire unsteady NS equations,which can be used as a benchmark problem for numerical code validation.

关键词： unsteady stagnation point flow Navier-Stokes(NS)equations analytical solution heat transfer

NUMERICAL SIMULATION Of COLUMNAR TO EQUIAXED TRANSITION fOR DIRECTIONALLY SOLIDIfIED Ti-44Al ALLOY

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Acta Metallurgica Sinica(English Letters) 2008年第2期21卷 146-156页

作者： k.f. wang J.J. Guo G.f. Mi C. Y. Li H.Z. fu School of IVlaterials Science and Engineering Henan Polytechnic University Jiaozuo 454100 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

Solute diffusion controlled solidification model was applied to simulate the columnar to equiaxed transition （CET） during directional solidification of Ti-44Al alloy. The simulation results show that the solutal interactions from growing equiaxed grains play an important role on CET. The effects of the applied thermal gradient and pulling velocity, the equiaxed seed spacing and nucleation undercooling on the CET are investigated in the present simulation. The simulated results indicated that the columnar branch spacing depends not only on the thermal gradient and the pulling velocity, but also on number of the seeds. A spacing adjustment can occur through initiation of seeds that develop into new columnar grains. The dependence of the CET on the thermal gradient and pulling velocity, qualitatively agrees with the analytical CET model of Hunt,

关键词： Ti-44Al alloy Directional solidification columnar to equiaxedtransition (CET) Numerical simulation