检索结果-南通市图书馆

Determination of Vapor Pressure of Liquid copper by carrier Gas Method

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2013年第12期29卷 1209-1213页

作者： y.J.Duan B.chen y.c.ma M.Gao K.Liu Institute of Metal Research Chinese Academy of Sciences

The relationship between the vapor pressure of liquid copper and the flow rate of carrier gas argon was discussed, when the carrier gas method was used to determine the vapor pressure of liquid copper at 1892 K. The proper argon flow rate range obtained was 150-500 mL/min and enough evidence was provided to verify the vapor pressure-flow rate of carrier gas relationship at the target temperature. Based on the proper flow rate range, the vapor pressure of liquid copper was measured at 1609-1892 K. The relationship of vapor pressure-temperature obtained by the method of regression analysis can be expressed as： In（p/Pa） = （25.470 -I- 0.903） - （39099.8 -4- 1574.5）/T, Further, the thermodynamic properties including the heat of vaporization and the Gibbs free energy of the cu （I） = cu （g） reaction were calculated by the vapor pressiJre obtained over the temperature range covered.

关键词： carrier gas method Liquid copper vapor pressure Thermodynamic property of copper

Solidification pathway and phase transformation behavior in a beta-solidified gamma-TiAl based alloy

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2019年第11期35卷 2652-2657页

作者： H.Xu X.B.Li W.W.Xing L.Shu y.c.ma K.Liu Institute of Metal Research Chinese Academy of SciencesShenyang 110016China MIIT Key Laboratory of Advanced Metallic and Intermetallic materials Technology Engineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

The phase transformation behavior of an as-cast Ti-42Al-5 Mn(at.%)alloy after subsequent quenching from 1380℃to 1000℃was investigated based on the differential thermal analysis(DTA),electron probe micro analyzer-backscattered electrons(EPma-BSE),transmission electron microscope(TEM)and X-ray diffraction(XRD).The results show that,the solidification path can be summarized as follows:Liquid→Liquid+β→β→β→α→β+α+γ→βo+α2+γ→βo+γ+α2/γ→βo+γ+α2/γ+βo,sec,with the phase transformationα→βtemperature(Tβ)=1311℃,phase transformationγ→βtemperature of(Tγsolv)=1231℃,phase transformationα2→αorβo→βtemperature(Tα2→α/Tβo→β)=1168 c,eutectoid temperature(Teut)=1132℃and T(α2/γ→βo,sec)≈1120℃.In comparison with Ti-42 Al alloy,the Teut and Tγsolv are slightly increased while both the Tp is decreased obviously by 5%Mn *** quenched from the temperature of 1380-1260℃,the martensitic transformationβ→α'could occur to form the needlelike martensite structure inβ*** kind of martensitic structure is much obvious with the increase of temperature from 1260℃to 1380℃.When the temperature is below Tγsolv(1231℃),theγgrains would nucleate directly from theβ*** the temperature slightly lower than T(eut)(1132℃),the dottedβ(o,sec)phases could nucleate in the lamellar colonies besides theγlamellae precipitated withinα2 ***,at room-temperature(RT),the alloy exhibits(po+α2+γ)triple phase with microstructure ofβo+lamellae+γ,of which the lamellar structure consists ofα2,γandβo,sec *** phase transformation mechanisms in this alloy,involvingβ→α',β→γ,α2→α2/γandα2→βo,sec were discussed.

关键词： Titanium aluminides Quenching Phase transformation Microstructure βphase

cHEMIcAL STUDIES OF MOTTLED ENAMEL AND BROWN STAIN

在线全文

学校读者我要写书评

暂无评论

中华医学杂志(英文版) 1932年第11期46卷 1099-1103页

作者： J.F.McINTOSH GEORGEMONTELIUS y.c.ma Department of Medicine and Division of Oral SurgeryPeiping Union Medical CollegePeiping.

The closely related conditions of the teeth known as mottled orchalky enamel,and brown stain are very common in certain regionsof North *** and Stevenson(1)have observed an in-cidence of chalky enamel as high as 82.6 per cent,and of brown stainas high as 45.4 per cent at *** well illustrated articlecomprises many interesting facts as to its incidence and ***(2)and McKay(3)have shown that the chalky state of theenamel is the primary *** is present at the time of erup-tion of the permanent teeth,and seems due to a defect in the forma-

关键词：

Dynamic Variation of Vegetation NPP and Its Driving Forces in the yellow River Basin, china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Geographical Science 2025年第1期35卷 24-37页

作者： WANG Shimei ma yutao GONG Jie JIN Tiantian Key Laboratory of Western china’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China center for Remote Sensing of Ecological Environments in cold and Arid Regions Lanzhou UniversityLanzhou 730000China

The productivity of vegetation is influenced by both climate change and human *** the specific contributions of these influencing factors is crucial for ecological conservation and regional *** study utilized a combination of multi-source data to examine the spatiotemporal patterns of Net Primary Productivity(NPP)in the yellow River Basin(yRB),china from 1982 to ***,a scenario-based approach was employed to compare Potential NPP(PNPP)with Actual NPP(ANPP)to determine the relative roles of climatic and human factors in NPP *** PNPP was estimated using the Lund-Potsdam-Jena General Ecosystem Simulator(LPJ-GUESS)model,while ANPP was evaluated by the carnegie-Ames-Stanford Approach(cASA)model using different NDVI data *** model simulations revealed that significant greening occurring in the yRB,with a gradual decrease observed from southeast to *** to the LPJ_GUESS model simulations,areas experiencing an increasing trend in NPP accounted for 86.82% of the *** using GIMMS and MODIS NDVI data with cASA model simulations,areas showing an increasing trend in NPP accounted for 71.42% and 97.02%,***,both climatic conditions and human factors had positive effects on vegetation restoration;approximated 41.15% of restored vegetation areas were influenced by both climate variation and human activities,while around 31.93% were solely affected by climate ***,it was found that human activities served as the principal driving force of vegetation degradation within the yRB,impacting 26.35% of degraded areas solely due to human ***,effective management strategies encompassing both human activities and climate change adaptation are imperative for facilitating vegetation restoration within this *** findings will valuable for enhancing our understanding in NPP changes and its underlying factors,thereby contributing to improved ecological man

关键词： Net Primary Productivity(NPP) vegetation greening carnegie-Ames-Stanford Approach(cASA) Lund-Potsdam-Jena General Ecosystem Simulator(LPJ_GUESS) yellow River Basin(yRB),china

同方期刊数据库

Electromagnetic wave absorption and corrosion resistance performance of carbon nanoclusters/ce-Mn codoped barium ferrite composite materials

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2025年第3期32卷 699-709页

作者： Bo Li Lin ma Sinan Li Jiewu cui Xiaohui Liang Wei Sun Pengjie Zhang Nan Huang Song ma Zhidong Zhang Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Metallurgy Engineering Liaoning Institute of Science and TechnologyBenxi 117004China School of materials Science and Engineering Hefei University of TechnologyHefei 230009China Institute of Microelectronics Hangzhou Dianzi UniversityHangzhou 310018China BGRIMM magnetic materials&Technology co. Ltd.Beijing 100160China

To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research *** utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination ***,ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of ce replacing Fe sites were *** from ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and *** Bace_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-c(BcM-c)was calcined at 600°c,the minimum reflection loss of-20.1 dB was achieved at 14.43 *** Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 *** BcM-c/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%Nacl solution).The|Z|0.01Hz value of BcM-c remained at 106Ω·cm^(2)after 12 soaking *** successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.

关键词： electromagnetic wave absorption anticorrosion barium ferrite cerium and manganese doping carbon nanoclusters

Phosphorylation modification reverses the transcriptional inhibitory activity of csMyB4a in tea plants(camellia sinensis)

在线全文

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2025年第1期11卷 406-416页

作者： Guoliang ma yunyun Han Tongtong Li Tao Xia Liping Gao School of Life Science Anhui Agricultural UniversityHefeiAnhui 230036China State Key Laboratory of Tea Plant Biology and Utilization Key Laboratory of Tea Biology and Tea Processing of Ministry of AgricultureAnhui Provincial Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhui 230036China

The members of the fourth subgroup of R2R3-MyB(Sg4 members)are well-known inhibitors of phenylpropanoid and lignin synthesis *** c2 domain is closely related to the transcriptional inhibitory activity of Sg4 *** modification enhances the transcriptional inhibitory activity of Sg4 ***,we identified a phosphorylation site on the c2 domain of cs MyB4a from tea plants(camellia sinensis).A mitogen-activated protein kinase(maPK),named cs MPK3-2,phosphorylated this site on the c2 domain of cs *** experiments revealed that phosphorylation of cs MyB4a weakened its ability to inhibit the gene expression of PAL,c4H,and 4cL in the phenylpropanoid pathway and activated the expression of transcription factor yABBy5,maintaining the adaxial-abaxial polarity of the *** out Nt yAB5 in cs MyB4a transgenic tobacco partially repaired the leaf wrinkling phenotype caused by cs *** c1 domain exhibited an activation function when the c2 domain of cs MyB4a was phosphorylated by cs MPK3-2,causing this reversal *** results enrich our understanding of the regulatory diversity of Sg4 members.

关键词： camellia sinensis cs MyB4a Phenylpropanoid pathway maPK yABBy Leaf development

Embedding prescribed-time adaptive control protocol unveiling distributed consensus in multirobot systems via directed topology

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2025年第2期68卷 383-384页

作者： yonghao XIE Xinru ma Hengyu LI Shaorong XIE School of computer Engineering and Science Shanghai University School of Mechatronic Engineering and Automation Shanghai University

Recently, multirobot systems(MRSs) have found extensive applications across various domains, including industrial manufacturing, collaborative formation of unmanned equipment, emergency disaster relief, and war scenarios [1]. These advancements are largely supported by the development of consistency control theory. However, traditional dynamicsfree models may cause instability in complex robotic systems. Lagrangian dynamics offers a better approach for modeling these systems, as it facilitates controller design and optimization analysis. Despite this, challenges persist with unknown parameters and nonlinear friction within the systems.

关键词： Microrobots

同方期刊数据库

Synergistic enhancement of ion/electron transport by ultrafine nanoparticles and graphene in Li2FeTiO4/c/G nanofibers for symmetric Li-ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2025年第02期101卷 42-51页

作者： Wenjie ma yakun Tang yue Zhang Xiaohui Li Lang Liu Xueting Wang yuliang cao State Key Laboratory of chemistry and Utilization of carbon Based Energy Resources Key Laboratory of Energy Materials Chemistry Ministry of Education College of Chemistry Xinjiang University college of chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University

Low-cost Fe-based disordered rock salt（DRX） Li2FeTiO4is capable of providing high capacity(295 ma h g-1) by redox activity of cations(Fe2+/Fe4+and Ti3+/Ti4+) and anionic ***,DRX structures lack transport channels for ions and electrons,resulting in sluggish kinetics,poor electrochemical activity,and ***,graphene conductive carbon network permeated Li2FeTiO4（LFT/c/G） nanofibers are successfully prepared by a facile sol-gel assisted electrospinning *** Li2FeTiO4nanoparticles（2 nm） and one-dimensional（1D） structure provide abu ndant active sites and unobstructed diffu sion channels,accelerating ion *** addition,introducing graphene reduces the band gap and Li+diffusion barrier and improves the dynamic properties of Li2FeTiO4,thus achieving a relatively mild interfacial reaction and reversible redox *** expected,the LFT/c/1.0G cathode delivers a remarkable discharge capacity(238.5 ma h g-1),high energy density(508.8 Wh kg-1),and excellent rate capability(51.2 ma hg-1at 1.0 A g-1).Besides,the LFT/c/1.0G anode also displays a high capacity(514.5 ma h g-1at 500 ma g-1) and a remarkable rate capability(243.9 ma h g-1at 8 A g-1).Moreover,the full batteries based on the LFT/c/1.0G symmetric electrode demonstrate a reversible capacity of 117.0 ma h g-1after 100 cycles at 50 ma *** study presents useful insights into developing cost-effective DRX cathodes with durable and fast lithium storage.

关键词： 1D structure Disordered rock salt Li2FeTiO4 Graphene Lithium-ion battery electrode Rapid ion/electron transport

Association between Non-high-density Lipoprotein cholesterol to High-density Lipoprotein cholesterol Ratio(NHHR)and Stroke among Adults in the USA:A cross-Sectional NHANES Study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2025年第1期38卷 37-46页

作者： Haixia ma Huaqiu chen Peichang Wang Department of clinical Laboratory Xuanwu HospitalNational Clinical Research Center for Geriatric DiseasesCapital Medical UniversityBeijing 100053China National clinical Research center for Geriatric Disorders Xuanwu HospitalCapital Medical UniversityBeijing 100053China

Objective The relationship between non-high-density lipoprotein(NHDL)cholesterol to high-density lipoprotein cholesterol(HDL-c)ratio(NHHR)and stoke remains *** study aimed to evaluate the association between the adult NHHR and stroke occurrence in the United States of America(USA).Methods To clarify the relationship between the NHHR and stroke risk,this study used a multivariable logistic regression model and a restricted cubic spline(RcS)model to investigate the association between the NHHR and stroke,and data from the National Health and Nutrition Examination Survey(NHANES)from 2005 to *** and sensitivity analyses were conducted to test the robustness of the *** This study included 29,928 adult participants,of which 1,165 participants had a history of *** regression analysis of variables demonstrated a positive association between NHHR and stroke(OR 1.24,95%cI:1.03-1.50,P=0.026).compared with the lowest reference group of NHHR,participants in the second,third,and fourth quartile had a significantly increased risk of stroke after full adjustments(OR:1.35,95%cI:1.08-1.69)(OR:1.83,95%cI:1.42-2.36)(OR:2.04,95%cI:1.50-2.79).In the total population,a nonlinear dose-response relationship was observed between the NHHR and stroke risk(P non-linearity=0.002).This association remained significant in several subgroup *** investigation of the NHHR may enhance our understanding of stroke prevention and *** Our findings suggest a positive correlation between the NHHR and an increased prevalence of stroke,potentially serving as a novel predictive factor for *** intervention and management of the NHHR may effectively mitigate stroke *** studies are required to validate this association and further explore the underlying biological mechanisms.

关键词： NHHR Stroke NHANES cross-sectional study