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prEpArATION AND prOpErTIES OF Ni-Cr AND Fe-Cr-Al FILMS BY VACUUM EVApOrATION

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Acta Metallurgica Sinica(English Letters) 2003年第4期16卷 283-288页

作者： X.W. shi, Z.Y. Liu, B.C. Zeng and CM. LiInstitute of Materials science & technology, college of Mechanical engineering, south china university of technology, guangzhou 510640, china Inst. of Mat. Sci. and Technol. Coll. of Mech. Eng. South China Univ. of Technol. Guangzhou 510640 China

Ni-Cr and Fe-Cr-Al films deposited on the Al2O3 substrate are studied by a method of vacuum evaporation in this paper. Influence of resistance value on density and evaporation parameters of the films reveals that the resistance of films and the adhesion of films to substrates are determined by the evaporation time and the substrate temperate under the condition of the maximum vacuity of 6.2×10-4 pa, respectively.

关键词： vacuum evaporation resistance of film vacuity

UNIFOrM SUpErCONVErGENCE ANALYSIS OF A TWO-GrID MIXED FINITE ELEMENT METHOD FOr THE TIME-DEpENDENT BI-WAVE prOBLEM MODELING D-WAVE SUpErCONDUCTOrS

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Journal of Computational Mathematics 2024年第2期42卷 415-431页

作者： Yanmi Wu Dongyang shi pLA Information engineering university Zhengzhou 450001China School of Mathematics and Information sciences Yantai UniversityYantai 264005China

In this paper,a two-grid mixed finite element method(MFEM)of implicit Backward Euler(BE)formula is presented for the fourth order time-dependent singularly perturbed Bi-wave problem for d-wave superconductors by the nonconforming EQ_(1)^(rot) *** this approach,the original nonlinear system is solved on the coarse mesh through the Newton iteration method,and then the linear system is computed on the fine mesh with Taylor’s *** on the high accuracy results of the chosen element,the uniform superclose and superconvergent estimates in the broken H^(1)-norm are derived,which are independent of the negative powers of the perturbation parameter appeared in the considered *** results illustrate that the computing cost of the proposed two-grid method is much less than that of the conventional Galerkin MFEM without loss of accuracy.

关键词： Time-dependent Bi-wave problem Two-grid mixed finite element method Uniform superclose and superconvergent estimates

Facile Semiconductor p-n Homojunction Nanowires with Strategic p-Type Doping engineering Combined with Surface reconstruction for Biosensing Applications

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Nano-Micro Letters 2024年第10期16卷 15-30页

作者： Liuan Li shi fang Wei Chen Yueyue Li Mohammad Fazel Vafadar Danhao Wang Yang Kang Xin Liu Yuanmin Luo Kun Liang Yiping Dang Lei Zhao Songrui Zhao Zongzhi Yin Haiding Sun iGaN Laboratory School of MicroelectronicsUniversity of Science and Technology of ChinaHefei 230026People's Republic of China Department of Obstetrics and Gynecology The First Affiliated Hospital of Anhui Medical UniversityNo 218 Jixi RoadHefei 230022People's Republic of China Department of Electrical and Computer engineering McGill University3480 University StreetMontrealQC H3A 0E9Canada Union Hospital Tongji Medical CollegeHuazhong University of Science and TechnologyNo 1277 Jiefang Ave.Wuhan 430022People's Republic of China

photosensors with versatile functionalities have emerged as a cornerstone for breakthroughs in the future optoelectronic systems across a wide range of *** particular,emerging photoelectrochemical(pEC)-type devices have recently attracted extensive interest in liquid-based biosensing applications due to their natural electrolyte-assisted operating ***,a pEC-type photosensor was carefully designed and constructed by employing gallium nitride(GaN)p-n homojunction semiconductor nanowires on silicon,with the p-GaN segment strategically doped and then decorated with cobalt-nickel oxide(CoNiO_(x)).Essentially,the p-n homojunction configuration with facile p-doping engineering improves carrier separation efficiency and facilitates carrier transfer to the nanowire surface,while CoNiO_(x)decoration further boosts pEC reaction activity and carrier dynamics at the nanowire/electrolyte ***,the constructed photosensor achieves a high responsivity of 247.8 mA W^(-1)while simultaneously exhibiting excellent operating ***,based on the remarkable stability and high responsivity of the device,a glucose sensing system was established with a demonstration of glucose level determination in real human *** work offers a feasible and universal approach in the pursuit of high-performance bio-related sensing applications via a rational design of pEC devices in the form of nanostructured architecture with strategic doping engineering.

关键词： p-n GaN nanowires Strategic p-doping Surface decoration photoelectrochemical sensor Glucose sensing

Comparative Study of the Effects of Nano ZnO and CuO on the Biodegradation,Biocompatibility,and Antibacterial properties of Micro-arc Oxidation Coating of Magnesium Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 242-254页

作者： Ying Shen Xianfeng Shan Iniobong p.Etim Muhammad Ali Siddiqui Yang Yang Zewen shi Xuping Su Junxiu Chen Key Laboratory of Materials Surface science and technology of Jiangsu province Changzhou UniversityChangzhou213164China Department of Stomatology The Affiliated Xinhua Hospital of Dalian UniversityDalian116000China Department of physics University of CalabarCalabar540242Nigeria Metallurgical engineering Department NED University of Engineering and TechnologyUniversity RoadKarachi75270Pakistan Ningbo No.2 Hospital Ningbo315010China

This research systematically examined the degradation,antibacterial effects,and biocompatibility of micro-arc oxidation(MAO)coatings with nano CuO and ZnO on extruded Mg *** copper(Cu)and Zinc(Zn)possess antibacterial *** findings demonstrated that adding ZnO will appreciably reduce the degradation rate of MAO-coating alloy due to the self-sealing micro ***+MAO coating exhibited excellent antibacterial performance,with an antibacterial rate of over 90%within 6 h co-cultured with Staphylococcus ***,the antibacterial rate of ZnO+MAO coating reached 90%after 12 h *** test using MG63 cell indicated that the incorporation of CuO and ZnO did not notably affect the cell viability rate of the ***,after 14 days of culture,the CuO+MAO and ZnO+MAO coated samples exhibited higher alkaline phosphatase(ALp)activity than the MAO-coated and uncoated samples,suggesting favorable osteogenic properties.

关键词： Copper oxide Zinc oxide Micro-arc oxidation(MAO)coating Corrosion behavior Antibacterial characteristics

pressure transient characteristics of non-uniform conductivity fractured wells in viscoelasticity polymer flooding based on oil-water two-phase flow

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petroleum science 2024年第1期21卷 343-351页

作者： Yang Wang Jia Zhang shi-Long Yang Ze-Xuan Xu shi-Qing Cheng National Key Laboratory of petroleum resources and engineering China University of Petroleum(Beijing)Beijing102249China

polymer flooding in fractured wells has been extensively applied in oilfields to enhance oil *** contrast to water,polymer solution exhibits non-Newtonian and nonlinear behavior such as effects of shear thinning and shear thickening,polymer convection,diffusion,adsorption retention,inaccessible pore volume and reduced effective ***,the flux density and fracture conductivity along the hydraulic fracture are generally non-uniform due to the effects of pressure distribution,formation damage,and proppant *** this paper,we present an oil-water two-phase flow model that captures these complex non-Newtonian and nonlinear behavior,and non-uniform fracture characteristics in fractured polymer *** hydraulic fracture is firstly divided into two parts:high-conductivity fracture near the wellbore and low-conductivity fracture in the far-wellbore section.A hybrid grid system,including perpendicular bisection(pEBI)and Cartesian grid,is applied to discrete the partial differential flow equations,and the local grid refinement method is applied in the near-wellbore region to accurately calculate the pressure distribution and shear rate of polymer *** combination of polymer behavior characterizations and numerical flow simulations are applied,resulting in the calculation for the distribution of water saturation,polymer concentration and reservoir *** with the polymer flooding well with uniform fracture conductivity,this non-uniform fracture conductivity model exhibits the larger pressure difference,and the shorter bilinear flow period due to the decrease of fracture flow ability in the far-wellbore *** field case of the fall-off test demonstrates that the proposed method characterizes fracture characteristics more accurately,and yields fracture half-lengths that better match engineering reality,enabling a quantitative segmented characterization of the near-wellbore section with high fracture conductivity and th

关键词： polymer flooding Non-Newtonian fluid Non-uniform fracture conductivity Two-phase flow pressure transient analysis

Constructing the Impossible Differential of Type-II GFN with Boolean Function and Its Application to WArp

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Chinese Journal of Electronics 2024年第1期33卷 80-89页

作者： Jiali shi Guoqiang LIU Chao LI college of Liberal Arts and sciences National University of Defense Technology Hunan engineering research Center of Commercial Cryptography Theory and technology Innovation State Key Laboratory of Information Security Institute of Information Engineering

Type-Ⅱ generalized Feist el network(GFN) has attracted a lot of attention for its simplicity and high *** differential attack is one of the powerful cryptanalytic approaches for word-oriented block ciphers such as Feistel-like *** deduce the impossible differential of Type-Ⅱ GFN by analyzing the Boolean function in the middle *** main idea is to investigate the expression with the variable representing the plaintext(ciphertext) difference words for the internal state *** adopting the miss-in-the-middle approach,we can construct the impossible differential of Type-Ⅱ *** an illustration,we apply this approach to WArp,a lightweight 128-bit block cipher with a 128-bit key which was presented by Banik et *** SAC *** structure of WArp is a 32-branch Type-Ⅱ ***,we find two 21-round truncated impossible differentials and implement a 32-round key recovery attack on *** the 32-round key recovery attack on WArp,some observations are used to mount an effective *** the advantage of the early abort technique,the data,time,and memory complexities are 2125.69chosen plaintexts,2126.6832-round encryptions,and 2100-bit,*** the best of our knowledge,this is the best attack on WArp in the single-key scenario.

关键词： Ciphers Boolean functions parallel processing Complexity theory

research on the macro-and meso-mechanical properties of frozen sand mold based on Hertz-Mindlin with Bonding model

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particuology 2024年第5期88卷 176-191页

作者： Jianpei shi Zhongde Shan Haoqin Yang college of Mechanical and Electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China college of Material science and technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this study,macro-and meso-mechanical properties of frozen sand molds were discussed based on the Hertz-Mindlin with Bonding(HMB)***-Burman,steepest ascent,and central composite designs were utilized to propose a parameter calibration *** effects of mesoscopic parameter variations on the compressive strength and average gradient of stress-strain were investigated through response surface method *** showed that the relative error between the simulated and measured repose angle is 3.1%under calibrated intrinsic contact *** compressive strength and average stress-strain gradient primarily depend on the normal and shear stiffness per unit area,as well as the particle size and porosity of the silica ***,taking load-displacement curves of three frozen sand molds with different geometric characteristics as the target value,the reliability and effectiveness of the frozen sand mold HMB model were verified through uniaxial compression tests and discrete element simulations.

关键词： Frozen sand mold Hertz-Mindlin with Bonding model Uniaxial compression test Discrete element method Mechanical properties

Motion-pressure coupled control and simulation of long-endurance capability for multicapsule stratospheric airships

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Chinese Journal of Aeronautics 2024年第6期37卷 137-150页

作者： Zhiguang shi Wei HUO Zongyu ZUO School of automation science and Electrical engineering Beihang UniversityBeijing 100191China Beijing Near Space Airship technology Development Co. LtdBeijing 100070China

The current study focuses on the motion-pressure coupled control for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold control of airships into guidance tracking with a time-varying weighted sum of longitudinal and lateral velocities by the definition of compound ***,an improved nonlinear predictive control method is provided to reduce the control energy consumption by the rolling optimization of controller parameters based on finite time intervals,ensuring infinite-time path-tracking ***,combined with the proposed cyclic regulation process of safe pressure between internal and external capsules,this study can fully reflect the force-thermal coupled rule of airships under the actions of atmospheric environment and maneuvering force,while evaluating the long-endurance capability of airships under the conditions of safe superheating and *** effectiveness of the motionpressure coupled controller was verified through numerical simulations,which can overcome the influence of environmental wind and achieve a tracking effect for the desired cruise path and compound *** airspeed provided during the cyclic circadian time caused the maximum superheating of the helium controlled within 30*** helium in the internal and external capsules achieved circadian *** equivalent micropore diameter of the capsule of 5 mm can achieve 55 days of long-endurance *** controller satisfies the requirements of cruise-flight application modes for multicapsule stratospheric airships with important engineering value.

关键词： Compound speed Nonlinear predictive control Cyclic pressure regulation Long-endurance capability Stratospheric airship

Design and Gait planning of a Worm-inspired Metameric robot for pipe Crawling

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Journal of Bionic engineering 2024年第3期21卷 1265-1277页

作者： Yu Liu Qingbiao shi Zhen Chen pen-Tung Sah Institute of Micro-Nano science and technology Xiamen UniversityXiamen361102China

The earthworm has been attracted much attention in the research and development of biomimetic robots due to their unique locomotion mechanism,compact structure,and small motion *** paper presents a new design and prototype of a worm-inspired metameric robot with a movement pattern similar to that of *** robot consists of multiple telescopic modules connected in series through joint *** telescopic module mimics the contraction and elongation motion modes of the earthworm segments.A kinematic and dynamic analysis is conducted on the telescopic module,and an input torque calculation method is provided to ensure sufficient friction between the robot and the pipe *** gait modes of the prototype robot for straight and turning locomotion are introduced,and these modes are extended to robots constructed by different numbers of telescopic *** addition,a method is proposed to increase the friction between the robot and the pipe wall in the aforementioned gait modes without changing the robot structure,thereby improving the robot’s motion ability in *** theoretical model of gait modes has also been validated through gait *** findings of this paper would provide a useful basis for the design,modeling,and control of future worm inspired robots.

关键词： Bio-inspired robot Spatial linkage mechanism Kinematics model peristaltic locomotion