检索结果-南通市图书馆

Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

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 Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： kun Gao Yan peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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

China Foundry 2024年第1期21卷 82-90页

作者： kun Gao Yan peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

Tensor perturbations from bounce inflation scenario in f(Q)gravity

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 78-92页

作者： kun hu Tanmoy Paul Taotao Qiu Institute of Astrophysics Central China Normal UniversityWuhan 430079China School of Physics Huazhong University of Science and TechnologyWuhan 430074China National Institute of Technology Jamshedpur Department of PhysicsJamshedpur 831014India

In this paper,we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity,namely f(Q)theory,and investigate the tensor perturbations *** is well-known,the tensor perturbations generated in the very early Universe(inflation and pre-inflation regions)can account for the primordial gravitational waves(PGWs)that are to be detected by the next generation of GW *** discuss the stability condition of the tensor perturbations in the bounce inflation process and investigate in detail the evolution of the perturbation *** general form of the tensor power spectrum is obtained both for large as well as small scale *** a result,we show both kinds of modes(short or long wavelength modes),and the tensor spectrum may get a positive tilt in the parametric range where the tensor perturbation proves to be stable—this interestingly hints an enhancement of gravitational waves’amplitude in the background of the f(Q)bounce-inflation ***,we study the LQC-like scenario as a specific case of our model,in which,the primordial tensor power spectrum turns out to be nearly scale-invariant on both small and large scales.

关键词： bounce cosmology modified gravity cosmological perturbations

Flotation separation of feldspar from quartz using sodium fluosilicate as a selective depressant

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1288-1300页

作者： Xin hu Xian-Ping Luo Zi-Shuai Liu Yong-Bing Zhang He-peng Zhou Zhi-Zhao Yang Xue-kun Tang Faculty of Resource and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou341000China Yichun Lithium New Energy Industry Research Institute Jiangxi University of Science and TechnologyYichun336000China

The physical and chemical properties of feldspar and quartz are highly similar,thus they cannot be easily separated *** this work,the flotation separation of feldspar from quartz using sodium fluosilicate(Na_(2)SiF_(6);SF)as a selective depressant was ***,the influence mechanism of SF on the selective flotation separation of feldspar and quartz was investigated via flotation tests,chemical analysis of flotation solution,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and contact angle *** results of the flotation tests show that feld spar and quartz without SF treatment have good *** SF treatment,feldspar still has good floatability,whereas quartz has significantly reduced *** solution chemical analysis shows that the functional group plays an important role in depressing the quartz is[SiF_(6)]^(2-).FTIR,XPS and contact angle analysis results show that[SiF_(6)]^(2-)is adsorbed only on the surface of ***,a thin hydrophilic SiOF layer is generated on the surface,which interferes with the adsorption of the collector on the surface of the *** phenomenon leads to a significant reduction in quartz's ***,SF has a good ability to separate feldspar from quartz by flotation.

关键词： Flotation separation Depressants Sodium fluorosilicate Quartz Feldspar

Giant reversible barocaloric effects with high thermal cycle stability in epoxybonded(MnCoGe)_(0.96)(CuCoSn)_(0.04) composite

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第11期31卷 2528-2534页

作者： Yafei Kuang kun Tao Bo Yang peng Tong Yan Zhang Zhigang Sun Kewei Zhang Dunhui Wang Jifan hu Liang Zuo College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Shanxi Key Laboratory of Magnetic and Electric Functional Materials and Applications Taiyuan University of Science and TechnologyTaiyuan 030024China Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031China Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China

Hexagonal MnMX-based(M=Co or Ni,X=Si or Ge)alloys exhibit giant reversible barocaloric ***,giant volume expansion would result in the as-cast MnMX ingots fragmenting into powders,and inevitably bring the deterioration of mechanical properties and *** fragmentation can bring degradation of structural transformation entropy change during cyclic application and removal of *** this paper,giant reversible barocaloric effects with high thermal cycle stability can be achieved in the epoxy bonded(MnCoGe)0.96(CuCoSn)0.04 *** reversible isothermal entropy change of 43.0 J·kg^(−1)·K^(−1) and adiabatic temperature change from barocaloric effects(ΔT_(BCE))of 15.6 K can be obtained within a wide temperature span of 30 K at 360 MPa,which is mainly attributed to the integration of the change in the transition temperature driven by pressure of−101 K·GPa^(−1) and suitable thermal hysteresis of 11.1 ***,the variation of reversibleΔ_(TBCE) against the applied hydrostatic pressure reaches up to 43 K·GPa^(−1),which is at the highest level among the other reported giant barocaloric *** importantly,after 60 thermal cycles,the composite does not break and the calorimetric curves coincide well,demonstrating good thermal cycle stability.

关键词： barocaloric effects cycle stability reversible isothermal entropy change reversible adiabatic temperature change MnCoGe alloys

Paracrine function amplifies pro-tumor electrochemical signal within neuron-glioma synapses

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第6期67卷 1318-1320页

作者： Yan hu Peishan hu Xiaozhong peng Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE State Key Laboratory of BiotherapyWest China Second University HospitalSichuan UniversityChengdu 610041China Guangdong Institute of Gastroenterology Department of General SurgeryGuangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesThe Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655China Department of Molecular Biology and Biochemistry Institute of Basic Medical SciencesMedical Primate Research CenterNeuroscience CenterChinese Academy of Medical SciencesSchool of Basic Medicine Peking Union Medical CollegeBeijing 100730China State Key Laboratory of Respiratory Health and Multimorbidity Institute of Basic Medical Sciences Chinese Academy of Medical SciencesSchool of Basic Medicine Peking Union Medical CollegeBeijing 100730China Institute of Laboratory Animal Science Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

Neuronal activity plays a pivotal role in various physiological processes,including tissue development,homeostasis,and *** in recent years have improved our understanding of neuronal activity in brain cancers,such as glioblastoma(GBM)and diffuse midline gliomas(DMG),which are among the most prevalent and lethal cancers affecting children and ***,the neurons regulate brain cancers via two routes.

关键词： glioma homeostasis function

WSN Mobile Target Tracking Based on Improved Snake-Extended Kalman Filtering Algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2024年第1期33卷 28-40页

作者： Duo peng kun Xie Mingshuo Liu School of Computer and Communication of Lanzhou University of Technology Lanzhou Gansu 730050China

A wireless sensor network mobile target tracking algorithm(ISO-EKF)based on improved snake optimization algorithm(ISO)is proposed to address the difficulty of estimating initial values when using extended Kalman filtering to solve the state of nonlinear mobile target ***,the steps of extended Kalman filtering(EKF)are ***,the ISO is used to adjust the parameters of the EKF in real time to adapt to the current motion state of the mobile ***,the effectiveness of the algorithm is demonstrated through filtering and tracking using the constant velocity circular motion model(CM).Under the specified conditions,the position and velocity mean square error curves are compared among the snake optimizer(SO)-EKF algorithm,EKF algorithm,and the proposed *** comparison shows that the proposed algorithm reduces the root mean square error of position by 52%and 41%compared to the SOEKF algorithm and EKF algorithm,respectively.

关键词： wireless sensor network(WSN)target tracking snake optimization algorithm extended Kalman filter maneuvering target

Performance Analysis and Optimization of Energy Harvesting Modulation for Multi-User Integrated Data and Energy Transfer

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第1期21卷 148-162页

作者： Yizhe Zhao Yanliang Wu Jie hu kun Yang School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Integrated data and energy transfer(IDET)enables the electromagnetic waves to transmit wireless energy at the same time of data delivery for lowpower *** this paper,an energy harvesting modulation(EHM)assisted multi-user IDET system is studied,where all the received signals at the users are exploited for energy harvesting without the degradation of wireless data transfer(WDT)*** joint IDET performance is then analysed theoretically by conceiving a practical time-dependent wireless *** the aid of the AO based algorithm,the average effective data rate among users are maximized by ensuring the BER and the wireless energy transfer(WET)*** results validate and evaluate the IDET performance of the EHM assisted system,which also demonstrates that the optimal number of user clusters and IDET time slots should be allocated,in order to improve the WET and WDT performance.

关键词： energy harvesting modulation(EHM) integrated data and energy transfer(IDET) performance analysis wireless data transfer(WDT) wireless energy transfer(WET)

Blockchain-Based Key Management Scheme Using Rational Secret Sharing

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 307-328页

作者： Xingfan Zhao Changgen peng Weijie Tan kun Niu State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China Guizhou Big Data Academy Guizhou UniversityGuiyang550025China

Traditional blockchain key management schemes store private keys in the same location,which can easily lead to security issues such as a single point of ***,decentralized threshold key management schemes have become a research focus for blockchain private key *** security of private keys for blockchain user wallet is highly related to user identity authentication and digital asset *** threshold blockchain private key management schemes based on verifiable secret sharing have made some progress,but these schemes do not consider participants’self-interested behavior,and require trusted nodes to keep private key fragments,resulting in a narrow application scope and low deployment efficiency,which cannot meet the needs of personal wallet private key escrow and recovery in public *** design a private key management scheme based on rational secret sharing that considers the self-interest of participants in secret sharing protocols,and constrains the behavior of rational participants through reasonable mechanism design,making it more suitable in distributed scenarios such as the public *** proposed scheme achieves the escrow and recovery of personal wallet private keys without the participation of trusted nodes,and simulate its implementation on smart *** to other existing threshold wallet solutions and keymanagement schemes based on password-protected secret sharing(PPSS),the proposed scheme has a wide range of applications,verifiable private key recovery,low communication overhead,higher computational efficiency when users perform one-time multi-key escrow,no need for trusted nodes,and personal rational constraints and anti-collusion attack capabilities.

关键词： Blockchain smart contract rational secret sharing key management