检索结果-南通市图书馆

Direct extraction of Mo(Ⅵ) from sulfate solution by synergistic extractants in the rotation column

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第2期28卷 445-455页

作者： Benyamin Shakib Meisam Torab-Mostaedi Mohammad Outokesh Mehdi Asadollahzadeh Department of Energy Engineering Sharif University of TechnologyP.O.Box 11365-8639TehranIran Materials and Nuclear Fuel Research School Nuclear Science and Technology Research InstituteP.O.Box:11365-8486TehranIran

Direct extraction of molybdenum from sulfate solution with synergistic extractants(mixture of D2EHPA and TBP)was studied in the rotation column.The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments.The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase.In the continuous experiments,the effect of different operating parameters such as speed of agitation,inlet solvent flow rate and inlet aqueous flow rate on the holdup,mean drop size,drop size distribution,slip and characteristic velocities and extraction percentage were examined.Modified correlations were proposed for prediction of hydrodynamic parameters with consideration of reaction extraction condition in the rotation column.Furthermore,these correlations were compared with the experimental data.According to the results,the direct extraction of Mo(Ⅵ)from aqueous solution and sulfuric media with extraction efficiency of 90.4%was obtained at higher rotor speed(240 r·min–1 rpm)in this column.

关键词： Direct extraction Molybdenum rotation column Synergistic Extractant

Method of ballistic control and projectile rotation in a novel railgun

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2018年第5期14卷 628-634页

作者： Bo Tang Ying-tao Xu Gang Wan Jiang Yue Yong Jin Hai-yuan Li National Key Laboratory of Transient Physics Nanjing University of Science and Technology

In order to realize the ballistic control of the railgun and the flight stability of the projectile, a new type of railgun is designed, which can control the muzzle velocity and rotation rate. The method of the muzzle velocity and overload control is to adjust the voltage or other parameters of pulse power supply. It would be easy to change velocity accurately in large wide. Another widespread concern problem is launching the spinning stability projectile by railgun. This paper designed a new structure of additional rails to generate an unsymmetrical magnetic field to produce rotational torque in armature. The structure is simple and can control the rotation rate by linear changing the barrel parameters. The calculation formulas of interior ballistic are derived by Biot-Safar law. The important parameter is the deflection angle of the additional rails relative to the symmetry plane of main rail. The larger the angle, the greater the rotation torque generated in the armature. To maintain the flight stability of the projectile, the barrel structural parameters should be proportional to the projectile structural parameters. When changing the muzzle velocity, the rotation rate will also be the equal proportion change. So that the gyro stability is the same. The experiment proves that the railgun designed in this paper can launch the projectile to rotate. And the rotational projectile may not cause the transition or much arcs. This method expands the application of the railgun.

关键词： Ballistic control Railgun rotation Spin-stabilized projectile

Numerical Solution of a Problem of Thermal Stresses of a Magnetothermoelastic Cylinder with rotation by Finite-Difference Method

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第9期68卷 3339-3352页

作者： F.S.Bayones A.M.Abd-Alla A.M.Farhan Department of Mathematics and Statistics College of ScienceTaif UniversityTaif21944Saudi Arabia Department of Mathematics Faculty of ScienceSohag UniversityEgypt Physics Department Faculty of ScienceJazan UniversityJazanSaudi Arabia Physics Department Faculty of ScienceZagazig UniversityZagazigEgypt

The present article deals with the investigation thermal stress of a magnetothermoelastic cylinder subjected to rotation,open or closed circuit,thermal and mechanical boundary conditions.The outer and inner surfaces of the cylinder are subjected to both mechanical and thermal boundary conditions.A The transient coupled thermoelasticity in an infinite cylinder with its base abruptly exposed to a heat flux of a decaying exponential function of time is devised solve by the finite-difference method.The fundamental equations’system is solved by utilizing an implicit finite-difference method.This current method is a second-order accurate in time and space;it is also unconditionally stable.To illustrate the present model’s efficiency,we consider a suitable material and acquire the numerical solution of temperature,displacement components,and the components of stresses with time t and through the radial of an infinite cylinder.The results indicate that the effect of coupled thermoelasticity,magnetic field,and rotation on the temperature,stresses,and displacement is quite pronounced.In order to illustrate and verify the analytical developments,the numerical solution of partial differential equations,stress components,displacement components and temperature is carried out and computer simulated results are presented graphically.This study is helpful in the development of piezoelectric devices.

关键词： Thermoelasticity thermal stress finite-difference method non-homogeneous material rotation magnetic field

Influence of the Earth's rotation on measurement of gravitational constant G with the time-of-swing method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第2期29卷 137-141页

作者：罗杰董涛邵成刚谈玉杰张惠捷 School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China MOE Key Laboratory of Fundamental Physical Quantities Measurement&Hubei Key Laboratory of Gravitation and Quantum Physics PGMF and School of PhysicsHuazhong University of Science and TechnologyWuhan 430074China

In the measurement of the Newtonian gravitational constant G with the time-of-swing method,the influence of the Earth's rotation has been roughly estimated before,which is far beyond the current experimental precision.Here,we present a more complete theoretical modeling and assessment process.To figure out this effect,we use the relativistic Lagrangian expression to derive the motion equations of the torsion pendulum.With the correlation method and typical parameters,we estimate that the influence of the Earth's rotation on G measurement is far less than 1 ppm,which may need to be considered in the future high-accuracy experiments of determining the gravitational constant G.

关键词： the Earth's rotation relativistic Lagrangian G measurement time-of-swing method

Effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids by using the Lord-Shulman and dual-phase-lag models

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1135-1154页

作者： S.M.ABO-DAHAB A.M.ABD-ALLA A.A.KILANY Department of Mathematics Faculty of SciencesTaif UniversityTaif 888Saudi Arabia Department of Mathematics Faculty of ScienceSouth Valley UniversityQena 83523Egypt Department of Mathematics Faculty of ScienceSohag UniversitySohag 82524Egypt

The effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids in a generalized thermoplastic half-space are studied by using the Lord-Shulman (L-S) model and the dual-phase-lag (DPL) model. The analytical solutions for the displacements, stresses, temperature, diffusion concentration, and volume fraction field with different values of the magnetic field, the rotation, the gravity, and the initial stress are obtained and portrayed graphically. The results indicate that the effects of gravity, rotation, voids, diffusion, initial stress, and electromagnetic field are very pronounced on the physical properties of the material.

关键词： electromagnetic field gravity field rotation initial stress voids diffusion normal mode analysis Lord-Shulman (L-S) model dual-phase-lag (DPL) model

Bioinspired rotation Microneedles for Accurate Transdermal Positioning and Ultraminimal-Invasive Biomarker Detection with Mechanical Robustness

在线全文

学校读者我要写书评

暂无评论

Research 2022年第3期2022卷 45-59页

作者： Yilin Cai Shiyi Huang Zhinan Zhang Jiazheng Zhang Xingyue Zhu Xiaoxiang Chen Xianting Ding State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Oncogenes and Related Genes Institute for Personalized MedicineSchool of Biomedical EngineeringShanghai Jiao Tong UniversityShanghai 200030China Department of Rheumatology Renji HospitalShanghai Jiao Tong University School of MedicineShanghaiChina

Microneedle permits transdermal biosensing and drug delivery with minor pain.However,accurate microneedle transdermal positioning with minimal skin deformation remains a significant technical challenge due to inhomogeneous skin topology and discontinuous force applied to the microneedle.Here,we introduce bioinspired rotation microneedles for in vivo accurate microneedle positioning as inspired by honeybees’stingers.We demonstrate the benefits of rotation microneedles in alleviating skin resistance through finite element analysis,full-thickness porcine validations,and mathematical derivations of microneedleskin interaction stress fields.The max penetration force was mitigated by up to 45.7%and the force attenuation rate increased to 2.73 times in the holding stage after penetration.A decrease in max skin deflection and a faster deformation recovery introduced by rotation microneedles implied a more precise penetration depth.Furthermore,we applied the rotation microneedles in psoriasis mice,a monogenic disorder animal model,for minimally invasive biological sample extraction and proinflammatory cytokine monitoring.An ultrasensitive detection method is realized by using only one microneedle to achieve cytokine mRNA level determination compared to commonly required biopsies or blood collection.Thus,rotation microneedles permit a simple,rapid,and ultraminimal-invasive method for subcutaneous trace biological sample acquisition and subsequent point-of-care diagnostics with minimal damage to both microneedles and skins.

关键词： rotation precise faster

rotation of hydrogen molecules during the dissociative adsorption on the Mg(0001) surface:a first-principles study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第5期19卷 577-582页

作者：李艳芳杨宇孙博宋红州卫英慧张平 College of Materials Science and Engineering Taiyuan University of Technology LCP Institute of Applied Physics and Computational Mathematics

Using first-principles calculations, we systematically study the potential energy surfaces and dissociation processes of the hydrogen molecule on the Mg（0001） surface. It is found that during the dissociative adsorption process with the minimum energy barrier, the hydrogen molecule first orients perpendicularly, and then rotates tobecome parallel to the surface. It is also found that the orientation of the hydrogen molecule in the transition state is neither perpendicular nor parallel to the surface. Most importantly we find that the rotation causes a reduction of the calculated dissociation energy barrier for the hydrogen molecule. The underlying electronic mechanism for the rotation of the hydrogen molecule is also discussed in the paper.

关键词： first-principles hydrogen dissociation rotation

A magneto -thermo-elastic problem for a half-space without energy dissipation subjected to rotation and gravity field

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2019年第1期4卷 55-63页

作者： A.M.Abd-Alla S.M.Abo-Dahab S.M.Ahmed M.M.Rashid Faculty of Science Mathematics DepartmentSohag UniversityEgypt Faculty of Science Mathematics DepartmentSouth Valley UniversityQena 83523Egypt Faculty of Science Mathematics DepartmentTaif University888Saudi Arabia Faculty of Science Mathematics DepartmentAl-Arish UniversityEgypt

The prime objective of the present paper is to analyze the effects of the rotation,magnetic field and gravity in a thermo-elastic half-space containing heat source on the boundary of the half-space.The medium assumed under consideration is traction free,homogeneous,isotropic,as well as without energy dissipation.The normal mode analysis and eigenvalue approach technique are used to solve the resulting non-dimensional coupled equations.The comparisons for the physical quantities are established numerically and represented graphically in different cases with respect to the used effects.A comparative and remarkable study has been carried out through various graphs to deliberate the consequences of different parameter on the displacement components,stress components and temperature.

关键词： Green-Naghdi theory Thermo-elasticity Energy dissipation rotation Magnetic field Gravity field.

Evolution of Low-Angle Normal Faults in the Enping Sag,the Northern South China Sea: Lateral Growth and Vertical rotation

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 Earth Science 2019年第6期30卷 1326-1340页

作者： Zhichao Zhou Lianfu Mei Hesheng Shi Yu Shu Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of GeosciencesWuhan 430074China Research Institute of Exploration and Development PetroChina Tuha Oil Field CompanyHami 839000China Shenzhen Branch of the China National Offshore Oil Corporation Shenzhen 518000China

Low-angle normal faults(dip<30°,LANFs)are widespread in the northern margin of the South China Sea where the maximum crust thickness is approximately 30.0 km.Based on 3 D seismic survey data and drilling wells in the Enping sag,evidences for LANFs that initially formed at high-angles are discussed.After a detailed investigation of extensional fault system and description of 3 D fault geometry,the initial fault dips under the model of distributed vertical simple shear are also calculated.The results indicate that the present-day dip angles of the LANFs are in the range of 12°to 29°,and the initial fault dip angles are in the range of 39°to 49°.Deep seismic imaging suggests that the upper crust in the footwall block of the LANFs was tilted at an angle of ~14°to 22°due to the isostatic rebound during rifting.Moreover,the temporal and spatial sequences of the lateral growth of the LANFs have been investigated by the seismic interpretation of four isochronous stratigraphic interfaces,which demonstrates that two individual fault segments propagated towards each other and subsequently,were hard-linked during the Early Eocene.

关键词： low-angle normal fault fault rotation fault growth Enping sag Pearl River Mouth Basin the South China Sea