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Transactions of Nonferrous Metals Society of China 2022年第8期32卷 2494-2509页

作者： Yue-hua SUN ri-chu wang Chao-qun PENG Xiao-feng wang School of Materials Science and Engineering Anhui University of TechnologyMaanshan 243002China School of Materials Science and Engineering Central South UniversityChangsha 410083China

The microstructure observation,tensile test,electrochemical measurement,and corrosion morphology characterization were conducted to study the effect of Gd on the microstructure,mechanical properties,and corrosion behavior of as-homogenized Mg−8Li−3Al−2Zn−0.2Zr(LAZ832−0.2Zr)*** addition of trace Gd can improve the mechanical properties of as-homogenized LAZ832−0.2Zr alloy by refining the microstructure,reducing the content of AlLi softening phase,and forming Al_(2)Gd strengthening ***,the addition of trace Gd can weaken the microgalvanic corrosion between matrix phase and AlLi phase,inhibit the galvanic corrosion betweenα-Mg phase andβ-Li phase,and result in the formation of dense oxide film containing Gd_(2)O_(3),thereby improving the corrosion resistance of the *** the Gd content is 1.0 wt.%,the alloy shows the best comprehensive properties with the ultimate tensile strength of 189.8 MPa,elongation of 42.3%,and corrosion rate(determined by hydrogen evolution)of 0.86 mm·a^(−1).

关键词： Mg-Li alloy rare earth Gd microstructure mechanical properties corrosion behavior

Hierarchical porous Co_(3)O_(4) spheres fabricated by modified solvothermal method as anode material in Li-ion batteries

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Transactions of Nonferrous Metals Society of China 2022年第4期32卷 1253-1260页

作者： Yan FENG Cai-yu CAO Jing ZENG ri-chu wang Chao-qun PENG Xiao-feng wang School of Materials Science and Engineering Central South UniversityChangsha 410083China Hunan Provincial Key Laboratory of Electronic Packaging and Advanced Functional Materials Changsha 410083China School of Metallurgy and Environment Central South UniversityChangsha 410083China

Hierarchical porous Co_(3)O_(4)spheres were synthesized by a solvothermal method followed by high-temperature ***,SEM,TEM and electrochemical tests were used to study the structure and performance of the hierarchical porous Co_(3)O_(4)*** results show that the Co_(3)O_(4)synthesized at a calcination temperature of 700°C(Co_(3)O_(4)-700)is micro-sized spheres(1-2μm)consisting of plentiful nanoparticles(50-200 nm)and numerous pores(~100 nm).Due to its numerous porous morphology,the Co_(3)O_(4)-700 anode exhibits the highest cycling performance with excellent reversible discharge and charge specific capacities of 745 and 755 m A·h/g at the current density of 100 m A/g after 100 charge-discharge cycles,respectively.

关键词： Co_(3)O_(4) lithium-ion batteries porous structure spheres calcination

Growth behavior and microstructure of intermetallics at interface of AuSn20 solder and metalized-Ni layer

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Transactions of Nonferrous Metals Society of China 2017年第5期27卷 1199-1205页

作者： Xiao-feng WEI Xue-wei ZHU ri-chu wang College of Mechanical and Electronic Engineering Northwest A&F University Yangling 712100 China School of Materials Science and Engineering Central South University Changsha 410083 China

The AuSn20/Ni joints were prepared by the reflow soldering technology and then annealed at solid-state temperature to form diffusion *** interfacial reactions and the growth kinetics of the intermetallic compounds(IMC)at the AuSn20/Ni soldering interface were investigated by scanning electron microscopy(SEM)and electron probe microanalysis(EPMA).The results show that,the(Ni,Au)3Sn2phases are formed at the AuSn20/Ni interface after soldering *** thickness l of the IMC layer monotonically increases with increasing annealing time t according to the relationship l=k(t/t0)n,where the exponent n is0.527,0.476and0.471for393,433and473K annealing,*** indicates that the volume diffusion contributes to the growth of the IMC layer at the AuSn20/Ni interface at solid-sate *** pre-exponential factor K0=1.23×10?7m2/s and the activation enthalpy QK=81.8kJ/mol are obtained from the results of the parabolic coefficient K by a least-squares method.

关键词： AuSn20/Ni joint interfacial reaction growth kinetics volume diffusion mechanism

Corrosion and discharge performance of Mg-9%Al-2.5%Pb alloy as anode for seawater activated battery

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Transactions of Nonferrous Metals Society of China 2016年第8期26卷 2144-2151页

作者： Min DENG ri-chu wang Yan FENG Nai-guang wang Lin-qian wang School of Materials Science and Engineering Central South University Changsha 410083 China

To obtain a new kind of Mg?Al?Pb alloy anode material with low content of Pb, the corrosion and discharge behavior of Mg?9%Al?2.5%Pb (hereafter in mass fraction) alloy were investigated by immersion tests and electrochemical techniques, and compared with those of Mg?6%Al?5%Pb alloy. The results indicate that Mg?9%Al?2.5%Pb alloy exhibits a lower self-corrosion rate and higher utilization efficiency in contrast with Mg?6%Al?5%Pb alloy because of the higher content of Al. As the result of the decrease of Pb content, the discharge activity of Mg?9%Al?2.5%Pb alloy is relatively weaker but still meets the requirement of anode. These results reveal that Mg?9%Al?2.5%Pb alloy with a low content of Pb can serve as a good candidate for the anode material used in seawater activated battery.

关键词： Mg.Al.Pb alloy anode material self-corrosion rate utilization efficiency discharge activity

Differentially private SGD with random features

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 1-23页

作者： wang Yi-guang GUO Zheng-chu Polytechnic Institute of Zhejiang University Zhejiang UniversityHangzhou 310015China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

In the realm of large-scale machine learning,it is crucial to explore methods for reducing computational complexity and memory demands while maintaining generalization ***,since the collected data may contain some sensitive information,it is also of great significance to study privacy-preserving machine learning *** paper focuses on the performance of the differentially private stochastic gradient descent(SGD)algorithm based on random *** begin,the algorithm maps the original data into a lowdimensional space,thereby avoiding the traditional kernel method for large-scale data storage ***,the algorithm iteratively optimizes parameters using the stochastic gradient descent ***,the output perturbation mechanism is employed to introduce random noise,ensuring algorithmic *** prove that the proposed algorithm satisfies the differential privacy while achieving fast convergence rates under some mild conditions.

关键词： learning theory differential privacy stochastic gradient descent random features reproducing kernel Hilbert spaces

Discharge performance of Mg-Al-Pb-La anode for Mg-air battery

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Transactions of Nonferrous Metals Society of China 2018年第11期28卷 2275-2287页

作者： Yan FENG Ge LEI Yu-qing HE ri-chu wang Xiao-feng wang School of Materials Science and Engineering Central South UniversityChangsha 410083China

b The discharge performance of Mg-Al-Pb-La anode was investigated by electrochemical techniques and compared withthat of Mg-Al-Pb alloy. The results indicate that the Mg-Al-Pb-La anode provides enhanced corrosion resistance at open circlepotential, and exhibits better discharge activity than the Mg-Al-Pb alloy. The utilization efficiency of Mg-Al-Pb-La anode ishigher than that of commercial Mg-Al-Zn （AZ） and Mg-Al-Mn （AM） alloys. A single Mg-air battery with Mg-Al-Pb-La alloy asthe anode and air as the cathode has an average discharge potential of 1.295 V and a discharge capacity of 1370 mA·h/g duringdischarge at 10 mA/cm2, which is higher than that of batteries using Mg-Li anodes. The enhancement in discharge performance ofthe Mg-Al-Pb-La anode is caused by its modified microstructure, which reduces the self-corrosion and accelerates the spalling ofoxidation products during battery discharge. Furthermore, the dissolution mechanism of Mg-Al-Pb-La anode during the dischargeprocess was analyzed.

关键词： Mg-air battery Mg-Al-Pb-La alloy corrosion resistance discharge activity utilization efficiency

Strigolactone regulates nitrogen-phosphorus balance in rice

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Science China(Life Sciences) 2024年第2期67卷 428-430页

作者： Huwei Sun Hanyun wang Chengcai chu Guangdong Provincial Key Laboratory of Plant Molecular Breeding College of AgricultureSouth China Agricultural UniversityGuangzhou 510642China Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China Ministry of Agriculture and Rural AffairsSouth China Agricultural UniversityGuangzhou 510642China Guangdong Laboratory for Lingnan Modern Agriculture Guangzhou 510642

Phosphorus(P) is one of the essential elements for growth and development of *** agriculture depends heavily on the application of large amounts of fertilizers,including P *** application of P fertilizers causes sever... 详细信息

关键词： pollution phosphorus fertilizers

Highly efficient expression of human extracellular superoxide dismutase(rhEcSOD)with ultraviolet-B-induced damage-resistance activity in transgenic silkworm cocoons

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Insect Science 2024年第4期31卷 1150-1164页

作者： Feng wang ri-Yuan wang De-Bin Zhong Ping Zhao Qing-You Xia Integrative Science Center of Germplasm Creation in Western China(CHONGQING)Science City Biological Science Research CenterSouthwest UniversityChongqingChina Century Legend Biotechnology Research Institute(Chongqing)Co. Ltd.ChongqingChina

Extracellular superoxide dismutase(EcSOD)protects tissues from oxidative stress,and thus is considered as a therapeutic agent for many diseases such as atherosclerosis,hypertension,and ***,cost-effective production of bioactive recombinant human EcSOD(rhEcSOD)remains a ***,we developed an efficient strategy for producing active rhEcSOD by transgenic *** was successfully synthesized as homodimers and homotetramers in the middle silk gland and spun into the cocoons with a concentration of 9.48±0.21 mg/*** of rhEcSOD from the cocoons could be conveniently achieved with a purity of 99.50%and a yield of 3.5±0.5 mg/***,N-glycosylation at the only site of N89 in rhEcSOD with 10 types were *** purified rhEcSOD gained the potent enzymatic activity of 4162±293 U/mg after Cu/Zn ions *** importantly,rhEcSOD was capable of penetrating and accumulating in the nuclei of cells to maintain cell morphology and attenuate ultraviolet B-induced cell apoptosis by eliminating reactive oxygen species and inhibiting the C-Jun N-terminal kinase signaling *** results demonstrated that the transgenic silkworm could successfully produce rhEcSOD with enzymatic and biological activities for biomedical applications.

关键词： antioxidant human extracellular superoxide dismutase recombinant expression silkworm silk gland

Optimizing piezoelectric performance of complex perovskite through increasing diversity of B-site cations

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Journal of Materials Science & Technology 2024年第3期170卷 78-86页

作者： Mengdi Cheng Dongyan Zhang Yangxi Yan Zhimin Li Pangpang wang ri-ichi Murakami School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China Nanomaterials Group Institute of SystemInformation Technologies and Nanotechnologies(ISIT)Fukuoka Industry-Academia Symphonicity(FiaS)4-1 KyudaishinmachiNishi-kuFukuoka 819-0388Japan School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Piezoelectric materials with unique properties are hugely appealing for high sensitivity sensors and ultrasonic ***,Pb(Ni_(1/3)Nb_(2/3))O_(3)-Pb(Yb_(1/2)Nb_(1/2))O_(3)-PbTiO_(3)piezoelectric system was designed and investigated in *** optimized piezoelectric response(d_(33)=826 pC/N,d_(33)∗=1017 pm/V)together with good temperature stability and negligible performance degradation up to 10^(6) cycles was achieved in 0.58PNN-0.10PYN-0.32PT *** analysis revealed the amplification of intrinsic and extrinsic contributions in MPB region due to more spontaneous polarization orientations and an increase in chemical disorder of system after the introduction of *** origin of high piezoelectric response was investigated through the combination of scanning electron microscopy and piezoresponse force *** diversity of B-site cations was shown to enhance local structural heterogeneity,weaken long-range ferroelectric ordered domains,and lower free energy barrier via the formation of nanodomain configuration that promoted polarization rotation,thereby improving piezoelectric properties of the ***,it is suggested that increasing the diversity of B-site cations is an effective strategy for achieving outstanding piezoelectric performance.

关键词： PNN-PYN-PT ceramics Piezoelectricity enhancement Relaxation behavior Domain structure

Recent progress in Mg-Li matrix composites

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Transactions of Nonferrous Metals Society of China 2019年第1期29卷 1-14页

作者： Yue-hua SUN ri-chu wang Chao-qun PENG Yan FENG Ming YANG School of Materials Science and Engineering Central South University Changsha 410083 China

Mg-Li matrix composites are one of the ideal structural materials in the fields of aerospace and military due to their high specific strength and stiffness, good damping and wear resistance, and small thermal expansion coefficient. The preparation technologies of Mg-Li matrix composites including powder metallurgy, pressure infiltration, stir-casting, foil metallurgy, and in-situ synthesis were introduced, and their advantages and disadvantages were compared. The common matrix alloys and reinforcements for Mg-Li matrix composites as well as the structure and performance of typical composites were mainly summarized. Then the interface chemistry between matrix and reinforcement was briefly reviewed. Finally, some problems existing at present and the possible solutions were discussed.

关键词： Mg-Li alloy composites preparation reinforcement interface chemistry