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Effect of addition of minor amounts of Sb and Gd on hot tearing susceptibility of Mg-5Al-3Ca alloy

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Journal of Magnesium and Alloys 2023年第2期11卷 694-705页

作者： Xudong du Feng wang Zhi wang le Zhou Zheng Liu Pingli Mao School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870P R China Key Laboratory of Magnesium Alloys and the Processing technology of Liaoning Province Shenyang 110870P R China

The effects of addition of minor amount of(0.5 wt.%) antimony(Sb) or gadolinium(Gd) and combined addition of Sb and Gd(0.5 wt.%,respectively) on the hot tearing susceptibility(HTS) of Mg-5Al-3Ca alloy were investigated experimentally using a “T-shaped” hot tearing measuring system. Various solidification parameters of the alloys were measured and calculated through thermal analysis experiments. The microstructure, grain size, and morphology of the crack zone were characterized by scanning electron microscopy and electron backscatter diffraction, and the crystal phases of the alloys were analyzed by X-ray diffraction and energy-dispersive X-ray spectroscopy. The results showed that the addition of 0.5 wt.% Gd resulted in the increase in the vulnerable temperature range(Tv) and reduced the eutectic structure content that could participate in feeding, thereby improving the HTS of the alloy. However, addition of 0.5 wt.% Sb or combined addition of Gd and Sb(0.5 wt.%, respectively) to the Mg-5Al-3Ca alloy shortened the Tvand improved the skeleton strength of the alloy, thereby reducing HTS. Moreover, significantly refined structure of Mg-5Al-3Ca-0.5Gd-0.5Sb alloy improved the feeding ability of the eutectic structure, thus the alloy exhibited the lowest HTS.

关键词： Hot tearing susceptibility Mg-5Al-3Ca alloy Thermal analysis Microstructure

Controllable preparation of particles with microfluidics

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Particuology 2011年第6期9卷 545-558页

作者： Guangsheng Luo le du Yujun wang Yangcheng Lu Jianhong Xu The State Key Laboratory of Chemical Engineering Department of Chemical Engineering Tsinghua University Beijing 100084 China

This paper reviews recent development and achievements in controllable preparation of nanoparticles, micron spherical and non-spherical particles, using microfluidics. A variety of synthesis strategies are presented and compared, including single-phase and multiphase microflows. The main structures of microfluidic devices and the fundamental principles of microflows for particle preparation are summarized and identified. The controllability of particle size, size distribution, crystal structure, morphology, physical and chemical properties, is examined in terms of the special features of microfluidic reactors. An outlook on opinions and predictions concerning the future development of powder technology with microfluidics is specially provided.

关键词： Microfluidics Nanoparticles Micron spherical particles Micron non-spherical particles Preparation technology

RESREARCH ON FLUID CHARACTERISTIC WITHIN THE ROTATING-WING HEAT METER

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Journal of Hydrodynamics 2006年第4期18卷 458-463页

作者： LIU Zheng-gang du Guang-sheng wang ning PAN Ji-hong School of Energy Source and Power Engineering Shandong University Jinan 250061 China

In order to improve the performance of rotating-wing heat meter and reduce the cost of development, the three dimensions numerical calculations of the intemal fluid characteristic within a heat meter are carried out based on the standard k-e turbulent mode, the finite volume method and SIMPle algorithm. The speed field and pressure distribution within heat meter are analyzed according to the result of numerical calculation. The flux measurement accuracy and pressure loss of basal meter are forecasted according to the calculated results. The calculated results of the impeller＇s rotating speed are compared with experimental results and prove the validity of the calculated results. This researches shows the calculated results can forecast the performance parameters of basal meter and can provide great help for design of the heat meter.

关键词： heat meter numerical calculation rotating-wing

Preparation and optical properties of Nb-NbN multilayer films as solar selective absorptive coatings

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Rare Metals 2006年第z1期25卷 355-359页

作者： wang Cong du Xinkang wang Tianmin ZHOU Long RU ning CHEN Buliang Center for Condensed Matter and Materials Physics School of Science Beijing University of Aeronoutics and Astronantics Beijing 100083 China Center for Condensed Matter and Materials Physics School of Science Beijing University of Aeronoutics and Astronantics Beijing 100083 China Mechanical Engineering College Shijiazhuang 050003 China Center for Condensed Matter and Materials Physics School of Science Beijing University of Aeronoutics and Astronantics Beijing 100083 China Center for Condensed Matter and Materials Physics School of Science Beijing University of Aeronoutics and Astronantics Beijing 100083 China Center for Condensed Matter and Materials Physics School of Science Beijing University of Aeronoutics and Astronantics Beijing 100083 China China Academy of Space Technology Beijing 100029 China

Based on the cermet double layer structure, Nb-NbN multi-layer films for solar selective coatings were deposited by direct current reactive magnetron sputtering. The Nb/Nb-NbN/Al2O3 trilayered structure was deposited on a stainless steel (SS) substrate by using a single niobium target. The expected components were adjusted by changing the gas flowing ratios of Ar: N2. The Al2O3 antireflective layer on the top of the film was produced by r. f. magnetron sputtering using Al2O3 ceramic target. A solar absorptivity of 0.94 and a normal emissivity of 0.16 at room temperature have been achieved for the coating. Thermal vacuum aging to the samples was carried out at 350 and 500 ℃ for 1 h. The results show a good thermal stability. Microstructure and its dependence on temperature of the Nb, NbN and Nb-NbN single layers were investigated, respectively.

关键词： Nb-NbN cermet film solar selective coating magnetron sputtering

Rapid Damage Prediction and Risk Assessment for Tropical Cyclones at a Fine Grid in Guangdong Province,South China

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International Journal of Disaster Risk Science 2023年第2期14卷 237-252页

作者： Yazhou ning Xianwei wang Qi Yu du Liang Jianqing Zhai School of Geography and Planning Sun Yat-sen UniversityGuangzhou510275China Guangdong Provincial Engineering Research Center for Public Security and Disasters Guangzhou510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519082China National Climate Center China Meteorological AdministrationBeijing100081China

Rapid damage prediction for wind disasters is significant in emergency response and disaster mitigation,although it faces many *** this study,a 1-km grid of wind speeds was simulated by the Holland model using the 6-h interval records of maximum wind speed(MWS) for tropical cyclones(TC) from 1949 to 2020 in South *** MWS during a TC transit was used to build damage rate curves for affected population and direct economic *** results show that the Holland model can efficiently simulate the grid-level MWS,which is comparable to the ground observations with R2 of0.71 to 0.93 and mean absolute errors(MAEs) of 3.3 to 7.5 m/*** estimated damage rates were in good agreement with the reported values with R^(2)=0.69-0.87 for affected population and R^(2)=0.65-0.84 for GDP *** coastal areas and the Guangdong-Hong Kong-Macao Greater Bay Area have the greatest risk of wind disasters,mainly due to the region’s high density of population and developed *** proposed method is suitable for rapid damage prediction and supporting emergency response and risk assessment at the community level for TCs in the coastal areas of China.

关键词： Damage prediction Holland model Risk assessment South China Tropical cyclones Wind disasters

Microelectrode Recording of Tissue Neural Oscillations for a Bionic Olfactory Biosensor

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Journal of Bionic Engineering 2012年第4期9卷 494-500页

作者： Qingjun Liu Fenni zhang ning Hu hua wang Kuen Jimmy Hsia Ping wang Biosensor National Special Laboratory Department of Biomedical Engineering Zhejiang University Hangzhou 310027 P. R. China Key Laboratory of Biomedical Engineering of Education Ministry Department of Biomedical Engineering Zhejiang University Hangzhou 310027 P. R. China Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 USA

In olfactory research, neural oscillations exhibit excellent temporal regularity, which are functional and necessary at thephysiological and cognitive levels. In this paper, we employed a bionic tissue biosensor which treats intact epithelium as sensing element to record the olfactory oscillations extracellularly. After being stimulated by odorant of butanedione, the olfactory receptor neurons generated different kinds of oscillations, which can be described as pulse firing oscillation, transient firing oscillation, superposed firing oscillation, and sustained firing oscillation, according to their temporal appearances respectively. With a time-frequency analysis of sonogram, the oscillations also demonstrated different frequency properties, such as δ, θ, α, β and γ oscillations. The results suggest that the bionic biosensor cooperated with sonogram analysis can well improve the in- vestigation of olfactory oscillations, and provide a novel model for artificial olfaetion sensor design.

关键词： bionic sensor olfactory epithelium microelectrode array (MEA) neural oscillation olfactory bioscnsor

Migration and transformation of Sb are affected by Mn(Ⅲ/Ⅳ)associated with lepidocrocite originating from Fe(Ⅱ)oxidation

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Journal of Environmental Sciences 2022年第5期34卷 308-318页

作者： Yalu Shao Qian Sun Liangkai wang Weiyong zhan Hongwei zhang hua Zhong State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China School of Agriculture and Food The University of MelbourneVictoria 3010Australia College of Agricultural Sciences and Engineering Hohai UniversityNanjing 210098China

Antimony(Sb)is a recognized priority pollutant with toxicity that is influenced by its mi-gration and transformation *** of Fe(Ⅱ)to Fe(Ⅲ)oxides,which is a com-mon phenomenon in the environment,is often accompanied by the formation of Mn(Ⅲ/Ⅳ)and might affect the fate of *** this study,incorporated Mn(Ⅲ)and sorbed/precipitated Mn(Ⅲ/Ⅳ)associated with lepidocrocite were prepared by adding Mn(Ⅱ)during and after Fe(Ⅱ)oxidation,respectively,and the effects of these Mn species on Sb fate were *** results indicated that the association of these Mn species with lepidocrocite obviously enhanced Sb(Ⅲ)oxidation to Sb(V),while concomitantly inhibiting Sb sorption due to the lower sorption capacity of lepidocrocite for Sb(V)than Sb(Ⅲ).Additionally,Mn oxide equivalents increased in the presence of Sb,indicating that Sb oxidation by Mn(Ⅲ/Ⅳ)associated with lepidocrocite was a continuous recycling process in which Mn(Ⅱ)released from Mn(Ⅲ/Ⅳ)reduction by Sb(Ⅲ)could be oxidized to Mn(Ⅲ/Ⅳ)*** recycling pro-cess was favorable for effective Sb(Ⅲ)***,Sb(Ⅴ)generated from Sb(Ⅲ)ox-idation by Mn(Ⅲ/Ⅳ)enhanced Mn(Ⅱ)sorption at the beginning of the process,and thus favored Mn(Ⅲ/Ⅳ)formation,which could further promote Sb(Ⅲ)oxidation to Sb(V).Over-all,this study elucidated the effects of Mn(Ⅲ/Ⅳ)associated with lepidocrocite arisen from Fe(Ⅱ)oxidation on Sb migration and transformation and revealed the underlying reaction mechanisms,contributing to a better understanding of the geochemical dynamics of Sb.

关键词： Antimony Manganese lepidocrocite Sorption Oxidation

Effects of potassium deficiency on photosynthesis,chloroplast ultrastructure,ROS,and antioxidant activities in maize(Zea mays L.)

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Journal of Integrative Agriculture 2019年第2期18卷 395-406页

作者： du Qi ZHAO Xin-hua XIA le JIANG Chun-ji wang Xiao-guang HAN Yi wang Jing YU Hai-qiu College of Agronomy Shenyang Agricultural UniversityShenyang 110866P.R.China Bureau of Liaoning Provincial Seed Management Shenyang 110034P.R.China

Potassium(K)deficiency significantly decreases photosynthesis due to leaf chlorosis induced by accumulation of reactive oxygen species(ROS).But,the physiological mechanism for adjusting antioxidative defense system to protect leaf function in maize(Zea mays L.)is *** the present study,four maize inbred lines(K-tolerant,90-21-3 and 099;K-sensitive,D937 and 835)were used to analyze leaf photosynthesis,anatomical structure,chloroplast ultrastructure,ROS,and antioxidant *** results showed that the chlorophyll content,net photosynthetic rate(P_n),stomatal conductance(G_s),photochemical quenching(q_P),and electron transport rate of PSII(ETR)in 90-21-3 and 099 were higher than those in D937 and 835 under K deficiency *** of leaf anatomical structure in D937 that were significantly changed under K deficiency treatment include smaller thickness of leaf,lower epidermis cells,and vascular bundle area,whereas the vascular bundle area,xylem vessel number,and area in 90-21-3 were significantly larger or higher.D937 also had seriously damaged chloroplasts and PSII reaction centers along with increased superoxide anion(O_2^-·)and hydrogen peroxide(H_2O_2).Activities of antioxidants,like superoxide dismutase(SOD),catalase(CAT),and ascorbate peroxidase(APX),were significantly stimulated in 90-21-3 resulting in lower levels of O_2^-·and H_2O_*** results indicated that the K-tolerant maize promoted antioxidant enzyme activities to maintain ROS homeostasis and suffered less oxidative damage on the photosynthetic apparatus,thereby maintaining regular photosynthesis under K deficiency stress.

关键词： potassium deficiency maize photosynthesis chloroplast ultrastructure ROS and antioxidant

Detection and characterization of an isolate of Tomato mottle mosaic virus infecting tomato in China

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Journal of Integrative Agriculture 2018年第5期17卷 1207-1212页

作者： zhan Bin-hui CAO ning wang Kai-na ZHOU Xue-ping State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChina Academy of Agricultural Sciences State Key Laboratory of Rice Biology Institute of BiotechnologyZhejiang University

Tomato（Solanum lycopersicum） plants exhibiting severe leaf distortion, mottle and systemic crinkling symptoms were identified in Hainan province in China in 2016. To survey and control the disease, it is necessary to identify and characterize the pathogen causing the disease. Dot enzyme-linked immunosorbent assay showed that the crude saps of the infected tomato samples reacted positively with the monoclonal antibody against Tobacco mosaic virus which indicated that one or more tobamoviruses are likely associated with the disease. RT-p CR and DNA sequence analysis results further elucidated that Tomato mottle mosaic virus（To MMV） in Tobamovirus was the pathogen causing the mottle disease in tomato. We amplified and sequenced the full-length sequence of the genome which showed the highest nucleotide identity with To MMV YYMLJ and To MMV Ti Lha LJ isolates. The putative virus isolate was named To MMV Hainan. Biological indexing studies showed that To MMV Hainan can infect Nicotiana benthamiana, Capsicum annuum and Solanum lycopersicum showing serious symptoms. This was the first identification and characterization of To MMV infecting tomato in Hainan of China.

关键词： Tomato mottle mosaic virus tomato Tobamovirus dot-ELISA biological characterization