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Microstructure and properties of hydrophobic films derived from Fe-W amorphous alloy

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International Journal of Minerals,Metallurgy and Materials 2014年第4期21卷 395-400页

作者： Song wang Yun-han Ling jun Zhang jian-jun wang Gui-ying Xu School of Materials Science and Engineering University of Science and Technology Beijing School of Materials Science and Engineering Tsinghua University

Amorphous metals are totally different from crystalline metals in regard to atom arrangement. Amorphous metals do not have grain boundaries and weak spots that crystalline materials contain, making them more resistant to wear and corrosion. In this study, amorphous Fe-W alloy films were first prepared by an electroplating method and were then made hydrophobic by modification with a water repellent （heptadecafluoro-1,1,2,2-tetradecyl） trimethoxysilane. Hierarchical micro-nano structures can be obtained by slightly oxidizing the as-deposited alloy, accompanied by phase transformation from amorphous to crystalline during heat treatment. The mi-cro-nano structures can trap air to form an extremely thin cushion of air between the water and the film, which is critical to producing hydrophobicity in the film. Results show that the average values of capacitance, roughness factor, and impedance for specific surface areas of a 600°C heat-treated sample are greater than those of a sample treated at 500°C. Importantly, the coating can be fabricated on various metal substrates to act as a corrosion retardant.

关键词： iron tungsten alloys amorphous films hydrophobicity microstructure contact angle capacitance

Preparation of spherical tungsten and titanium powders by RF induction plasma processing

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Rare Metals 2015年第6期34卷 431-435页

作者： jian-jun wang jun-Jie Hao Zhi-Meng Guo Yu-Ming wang Institute for Advanced Materials and Technology University of Science and Technology Beijing Department for Quality Supervision and Test Shougang Jingtang United Iron & Steel Co. Ltd

Spherical tungsten and titanium powders were prepared by radio frequency inductively coupled plasma torch with irregular shaped tungsten and titanium hydride （TiH2） powders, respectively. The effect of the feed rate on spheroidization efficiency was investigated. The phase composition, oxygen content, morphology, and particle size distribution of the powders before and after spheroidization were characterized by X-ray diffraction （XRD）, nitrogen/oxygen analyzer, scanning electron microscopy （SEM）, and laser micron sizer （LMS）. The results show that both kinds of plasma-processed powders have good dispersity, smooth surface, and single phase. A maximum of 100 % of spheroidization efficiency can be achieved at a lower feed rate. The spherical titanium powder obtained by the plasma treatment consists of particles with mean diameter of 33.34 gin, while the mean diameter of ori- ginal Till2 powder is 136.56 μm. The apparent density and flowability of the spherical tungsten powder are 6.3 ***-3 and 0.16 s.g-1, respectively. The apparent density and flowability of the spherical titanium powder are 2.8 ***-3 and 0.52 s.g-1, respectively. With the increase of the feed rate, the sphemidization efficiency of raw powders drops gradually.

关键词： RF induction plasma Tungsten and titaniumpowders Titanium hydride Spheroidization Apparentdensity Flowability

SCHEDULING JOBS WITH GENERAL LEARNING FUNCTIONS

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Journal of Systems Science and Systems Engineering 2011年第1期20卷 119-125页

作者： Li-Yan wang jian-jun wang Ji-Bo wang En-Min FENG School of Science Shenyang Aerospace University Shenyang 110136 China School of Mathematical Sciences Dalian University of Technology Dalian 116024 China School of Management Dalian University of Technology Dalian 116024 China

This paper deals with single-machine scheduling problems with a more general learning effect based on sum-of-processing-time. In this study, sum-of-processing-time-based learning effect means that the processing time of a job is defined by a decreasing function of the total normal processing time of jobs that come before it in the sequence. Results show that even with the introduction of the sum-of-processing-time-based learning effect to job processing times, single-machine makespan minimization problems remain polynomially solvable. The curves of the optimal schedule of a total completion time minimization problem are V-shaped with respect to iob normal orocessinz times.

关键词： Scheduling single machine learning effect makespan total completion time

Effect of ultrasonic power introduced by a mold copper plate on the solidification process

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 139-146页

作者： Xiao-fang Shi Li-zhong Chang jian-jun wang school of metallurgy engineering anhui university of technologyMa'anshan 243002China

An electroslag furnace with ultrasonic vibration introduced by a mold copper plate was designed. The effects of ultrasonic power on the element distribution and compactness in electroslag remelting （ESR） ingots were studied, and the mechanism of ultrasonic assistance was analyzed in cold experiments. In the results, silicon, manganese and chromium are uniformly distributed at an ultrasonic power of 300-750 W. The absence of ultrasonic or higher ultrasonic power is not conducive to the uniformity of alloying elements. Carbon demon- strates a highly uneven distribution at 300 W, gradually reaches the uniform distribution as the ultrasonic power further increases, and shows the poor distribution at 1000 W. The compactness of ESR ingots gradually increases with increasing ultrasonic power and reaches the uni- form distribution at 500 W. A further increase in ultrasonic power does not improve the compactness. Introducing ultrasonic vibrations by a mold copper plate can improve the solidification quality; however, an appropriate ultrasonic power level should be determined.

关键词： electroslag remelting mold ultrasonic solidification

Effect of mold rotation on the bifilar electroslag remelting process

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International Journal of Minerals,Metallurgy and Materials 2015年第10期22卷 1033-1042页

作者： Xiao-fang Shi Li-zhong Chang jian-jun wang School of Metallurgy Engineering Anhui University of Technology

A novel electroslag furnace with a rotating mold was fabricated, and the effects of mold rotational speed on the electroslag remelting process were investigated. The results showed that the chemical element distribution in ingots became uniform and that their compact density increased when the mold rotational speed was increased from 0 to 28 r/min. These results were attributed to a reasonable mold speed, which resulted in a uniform temperature in the slag pool and scattered the metal droplets randomly in the metal pool. However, an excessive rotational speed caused deterioration of the solidification structure. When the mold rotational speeds was increased from 0 to 28 r/min, the size of Al2O3 inclusions in the electroslag ingot decreased from 4.4 to 1.9 μm. But the excessive mold rotational speed would decrease the ability of the electroslag remelting to remove the inclusions. The remelting speed gradually increased, which resulted in reduced power consumption with increasing mold rotational speed. This effect was attributed to accelerated heat exchange between the consumable electrode and the molten slag, which resulted from mold rotation. Nevertheless, when the rotational speed reached 28 r/min, the remelting speed did not change because of limitations of metal heat conduction. Mold rotation also improved the surface quality of the ingots by promoting a uniform temperature distribution in the slag pool.

关键词： electroslag remelting inclusions solidification mo

Study of evaluation method for the overseas oil and gas investment based on risk compensation

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Petroleum Science 2020年第3期17卷 858-871页

作者： Zu-Xin Li jian-Ye Liu Dong-Kun Luo jian-jun wang School of Business Administration China University of Petroleum BeijingBeijing 102249China Department of Overseas New Ventures Assessment Research Institute of Petroleum Exploration and DevelopmentBeijing 100083China

The overseas oil and gas investment evaluation is one of the core tasks in overseas investment of oil and gas companies,among which risk evaluation and benefit evaluation are the most *** paper sets forth transmission paths of risk factors to the investment benefit by identifying 14 overseas oil and gas investment risks in four *** the basis of the concept of risk compensation,different compensation mechanisms specific to each risk are *** risk and benefit are integrated objectively to develop a comprehensive evaluation model by correcting the recoverable reserve,adjusting benefit evaluation parameters such as investments on exploration and development,and compensating for the changes in risk factors with time through dynamic discount ***,two cases studies,namely the evaluations of Project A in Sudan and comparison among Blocks A–G,are used to describe usage method and applicable scope of such evaluation model,*** to the results,oil price is a key influencing factor for enterprise internal risk and industrial *** compensation reduces comprehensive benefit of overseas oil and gas investment and undermines the investment feasibility and priority of *** research findings of this paper are free from the effects of some subject factors and avoid multi-objective decision making,and also avoid the undesired repeated calculation of risk factors.

关键词： Overseas oil and gas investment Investment evaluation Risk compensation Dynamic discount rate Comprehensive benefit

Efficient extraction of uranium(VI)from aqueous solution by Zr/Ce-UiO-66-NH_(2) modified by dual strategies of bimetallization and amination

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Nuclear Science and Techniques 2024年第11期35卷 124-137页

作者： Wen-Hui Song Chen wang Cheng-De Xie Zhi-Xiong Zhang jian-jun wang MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China

We modified Zr/Ce-UiO-66-NH_(2) using dual bimetallization and amination strategies to efficiently extract uranium from water ***,FTIR,and XPS indicated the successful alteration of material ***,the metal Zr was partially replaced by Ce in Zr-oxygen atom clusters in Zr/Ce-UiO-66-NH_(2).It possessed commendable structural stability in acidic and alkaline *** of whether it was submerged in a 6 M strong acid or in a 0.5M strong base solution,the structural integrity of Zr/Ce-UiO-66-NH_(2) remained *** experiments at pH=6.0 revealed that uranium adsorption by Zr/Ce-UiO-66-NH_(2) reached 376.8 mg g^(−1) and 611.33 mg g^(−1) at 298 K and 328 K,*** values are much better than those obtained using bimetallic-modified Zr/Ce-UiO-66 or amine-functionalized UiO-66-NH_(2).After five consecutive sorption and desorption cycles,the material retained a uranium removal rate of more than 80%,proving its excellent regenerative *** modeling of U(VI)adsorption on Zr/Ce-UiO-66-NH_(2) implied that chemisorption dominated the rapid uranium sorption *** propose potential adsorption mechanisms involving three interactions:inner-sphere surface complexation,chemisorption,and electrostatic *** study shows that the dual strategies of bimetallization and amination can effectively enhance U(VI)extraction from *** approach has potential applications for the structural design of uranium adsorbents.

关键词： MOF modification Zr/Ce-UiO-66-NH_(2) Adsorption uranium Adsorption mechanism

An improved method of potential of mean force for protein-protein interactions

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Chinese Science Bulletin 2008年第8期53卷 1145-1151页

作者： SU Yux LI WenFei ZHANG jian wang jun wang Wei National Laboratory of Solid State Microstructure and Department of Physics Nanjing University Nanjing 210093 China

In this work, the traditional method of potential of mean force (PMF) is improved for describing the protein-protein interactions. This method is developed at atomic level and is distance-dependent. Compared with the traditional method, our model can reasonably consider the effects of the environ- mental factors. With this modification, we can obtain more reasonable and accurate pair potentials, which are the pre-requisite for precisely describing the protein-protein interactions and can help us to recognize the interaction rules of residues in protein systems. Our method can also be applied to other fields of protein science, e.g., protein fold recognition, structure prediction and prediction of thermo- stability.

关键词：基础知识 PMF 双蛋白交互作用

Giant room temperature elastocaloric effect in metal-free thinfilm perovskites

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npj Computational Materials 2021年第1期7卷 1194-1201页

作者： Cheng Li Yu Hui Huang jian-jun wang Bo wang Yong jun Wu He Tian Long-Qing Chen Zijian Hong Laboratory of Dielectric Materials School of Materials Science and EngineeringZhejiang UniversityHangzhouChina Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPAUSA Cyrus Tang Center for Sensor Materials and Applications State Key Laboratory of Silicon MaterialsSchool of Materials Science and EngineeringZhejiang UniversityHangzhouChina Center of Electron Microscopy State Key Laboratory of Silicon MaterialsSchool of Materials Science and EngineeringZhejiang UniversityHangzhouChina

Solid-state refrigeration which is environmentally benign has attracted considerable ***(mC)materials,in which the phase transitions can be induced by mechanical stresses,represent one of the most promising types of solid-state caloric ***,we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric(eC)strengths for the(111)-oriented metal-free perovskite ferroelectric[MDABCO](NH_(4))I_(3)*** predicted room temperature isothermal eC ΔS_(eC)/Δσ(eC entropy change under unit stress change)and adiabatic eCΔTeC/Δσ(eC temperature change under unit stress change)for[MDABCO](NH_(4))I_(3) are−60.0 J K^(−1)kg^(−1)GPa^(−1) and 17.9 K GPa^(−1),respectively,which are 20 times higher than the traditional ferroelectric oxides such as BaTiO_(3) thin *** have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient(which could be realized through chemical doping,etc.).We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

关键词： ferroelectric perovskite free