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Rare Metals 2006年第Z2期25卷 146-149页

作者： chen Ling han jing YU Shengxue Department of Applied Chemistry Yanshan University Qinhuangdao 066004 China Department of Applied Chemistry Yanshan University Qinhuangdao 066004 China Department of Applied Chemistry Yanshan University Qinhuangdao 066004 China

In order to prepare ornamental and anti-corrosive coating on aluminum alloys, preparation technology of black micro-arc ceramic coatings on Al alloys in silicate based electrolyte was studied. The influence of content of Na2WO4 and combination additive in solution on the performance of black ceramic coatings was studied; the anticorrosion performances of black ceramic coatings were evaluated through whole-immersion test and electrochemical method in 3.5% NaCl solution at different pH value; SEM and XRD were used to analyze the surface morphology and phase constitutes of the black ceramic coatings. Experimental results indicated that, without combination additives, with the increasing of Na2WO4 content in the electrolyte, ceramic coating became darker and thicker, but the color was not black; after adding combination additive, the coating turned to be black; the black ceramic coating was multi-hole form in surface. There was a small quantity of tungsten existing in the black ceramic coating beside α-Al2O3 phase and β-Al2O3 phase. And aluminum alloy with black ceramic coating exhibited excellent anti-corrosion property in acid, basic and neutral 3.5% NaCl solution.

关键词： aluminum alloy micro-arc oxidation black coating anti-corrosion performance

An Initial Perturbation Method for the Multiscale Singular Vector in Global Ensemble Prediction

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Advances in Atmospheric Sciences 2024年第3期41卷 545-563页

作者： Xin LIU jing chen Yongzhu LIU Zhenhua HUO Zhizhen XU Fajing chen jing WANG Yanan MA Yumeng han School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing 210044China Chinese Academy of Meteorological Sciences Beijing 100081China CMA Earth System Modeling and Prediction Centre(CEMC) Beijing 100081China Key Laboratory of Earth System Modeling and Prediction of China Meteorological Administration Beijing 100081China Tianjin Meteorological Observatory Tianjin 300074China China Meteorological Administration Xiong’an Atmospheric Boundary Layer Key Laboratory Hebei 071799China

Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.

关键词： multiscale uncertainty singular vector initial perturbation global ensemble prediction system

Effect of slag composition on kinetic behavior of deep deoxidation of 5 wt.% Si high-silicon austenitic stainless steel

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Journal of Iron and Steel Research International 2024年第8期31卷 1873-1885页

作者： Guan-xiong Dou han-jie Guo jing Guo Xue-cheng Peng Qing-yun chen School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing 100083China

Based on a thermodynamic study of 5 wt.%Si high-silicon austenitic stainless steel(SS-5Si)smelting using CaF_(2)-CaO-Al_(2)0_(3)-Mg-Si0_(2) slag to obtain a low oxygen content of less than 10×10^(-4) wt.%,a kinetic mass transfer model for deep deoxidation was established through laboratory studies,and the effects of slag components and temperature on deoxidation during the slag-steel reaction process of sS-5Si were systematically *** experimental data verified the accuracy of the model *** results showed that the final oxygen content in the steel at 1873 K was mainly controlled by the oxygen content derived from the activity of SiO_(2) regulated by the[Si]-[O]equilibrium reaction in the slag system;in particular,when the slag basicity R(R=w(CaO)/w(SiO2),where w(CaO)and w(SiO_(2))are the contents of CaO and SiO_(2) in the slag,respectively)is 3,the Al2O3 content in the slag needs to be less than 2.7%.The mass transfer rate equation for the kinetics of the deoxidation reaction revealed that the mass transfer of oxygen in the liquid metal is the rate-controlling step under different slag conditions at 1873 K,and the oxygen transfer coefficient ko.m increases with increasing the slag basicity from 4.0×10^(-6)m s^(-1)(R=1)to 4.3×10^(-5) m s^(-1)(R=3).ko.m values at R=2 and R=3 are almost the same,indicating that high slag basicity has little *** integral of the mass transfer rate equation for the deoxidation reaction of SS-5Si under different slag conditions is *** total oxygen content of the molten steel decreases with increasing basicity from an initial content of 22×10^(-4) to 3.2×10^(-4) wt.%(R=3),consistent with the change in ko.m with slag *** R=2,the slag-steel reaction takes 15 min to reach equilibrium(w[O]=5.5×10^(-4) wt.%),whereas at R=3,the slag-steel reaction takes 30 min to reach equilibrium(w[0]=3.2×10^(-4) wt.%).Considering the depth of deoxidation and reaction time of SS-5Si smelting,it is recommended the slag b

关键词： Slag-steel reaction Kinetics Rate-controlling step Deep deoxidation Transfer coefficient

Thermodynamic and experimental study of high-temperature roasting of blast furnace gas ash for recovery of metallic zinc and iron

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Journal of Iron and Steel Research International 2024年第1期31卷 108-120页

作者： Zi-han Wang jing Guo han-jie Guo Bin Li School of Metallurgical Engineering University of Science and Technology BeijingBeijing100083China School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina

A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free *** results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron *** the full temperature range,iron oxides were more easily reduced than zinc *** of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of *** the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction *** the C/O ratio increased,the metallization and dezincification rates first increased and then *** effect of reduction time on BFA reduction was similar to that of reaction temperature.

关键词： Blast furnace gas ash Thermodynamics Zinc removal Iron reduction High-temperature reduction roasting Integrated utilization

Cellular Cd^(2+)fluxes in roots confirm increased Cd availability to rice(Oryza sativa L.)induced by soil acidifications

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Journal of Environmental Sciences 2024年第5期139卷 516-526页

作者： Xiaoyi Sun Meng Wang Luyao Qin Lei Yu jing Wang han Zheng Wenneng Zhou Shibao chen State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural SciencesBeijing 100081China Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds School of EcologyEnvironment and ResourcesGuangdong University of TechnologyGuangzhou 510006China

Soil acidifications become one of the main causes restricting the sustainable development of agriculture and causing issues of agricultural product *** order to explore the effect of different acidification on soil cadmium(Cd)availability,soil pot culture and hydroponic(soil potting solution extraction)were applied,and non-invasive micro-test technique(NMT)was *** three different soil acidification processes were simulated,including direct acidification by adding sulfuric acid(AP1),acid rain acidification(AP2)by adding artificial simulated acid rain and excessive fertilization acidification by adding(NH_(4))_(2)SO_(4)(AP3).The results showed that for direct acidification(AP1),DTPA-Cd concentration in field soils in Liaoning(S1)and Zhejiang(S2)increased by 0.167-0.217 mg/kg and 0.181-0.346 mg/kg,respectively,compared with control *** soil pH decreased by 0.45 units in S1,the Cd content of rice stems,leaves and roots increased by 0.48 to 6.04 mg/kg and 2.58 to 12.84mg/kg,respectively,When the pH value of soil S1 and S2 decreased by 0.20 units,the average velocity of Cd^(2+)at 200μm increased by 10.03-33.11 pmol/cm~2/sec and 21.33-52.86pmol/cm^(2)/sec,respectively,and followed the order of AP3>AP2>*** summary,different acidification measures would improve the effectiveness of Cd,under the same pH reduction condition,fertilization acidification increased Cd availability most significantly.

关键词： Soil acidification Cadmium Non-invasive micro-test technique Bioavailability

Gravitational wave fluxes on generic orbits in near-extreme Kerr spacetime:Higher spin and large eccentricity

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 16-28页

作者： Changkai chen Jiliang jing Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

To accurately obtain the waveform template of gravitational waves, substantial computational resources and extremely high precision are often required. In a previous study, we employed the confluent Heun function to obtain an exact solution to the Teukolsky equation. This approach allowed us to efficiently and accurately calculate the gravitational wave flux for a particle in circular orbits around a Schwarzschild black hole. Building on this method, we now extend its application to calculate the asymptotic gravitational wave fluxes from a particle in generic orbits around a near-extreme Kerr black hole. Our extended method proves particularly effective in handling computational challenges associated with large eccentricities(e = 0.9), higher spins(a = 0.999), higher harmonic modes, and strong-field regions. The results we obtained significantly outperform those derived from the numerical integration method based on the Mano-Suzuki-Takasugi method.

关键词： gravitational wave fluxes exact solution Teukolsky equation near-extreme Kerr black hole

Kerr black hole shadows cast by extraordinary light rays with Weyl corrections

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 18-26页

作者： Songbai chen Jiliang jing Department of Physics Institute of Interdisciplinary StudiesKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We investigate the equation of motion for photons with Weyl corrections in a Kerr black hole spacetime in a small coupling *** results show that Weyl corrections yield phenomena of *** light rays propagating in the spacetime are separated into the ordinary rays and the extraordinary rays,and the propagation of the latter depends on the *** probe the effects of Weyl corrections on the Kerr black hole shadows casted by the extraordinary rays and find that such corrections result in a weak stretching or squeezing in the vertical direction for the black hole ***,we also study the change of the length of the Near-Horizon Extremal Kerr line(NHEK line)with Weyl *** features could help us to understand the electrodynamics with Weyl corrections from black hole shadows.

关键词： correction light stretching

A Simple Proof of ACC for Minimal Log Discrepancies for Surfaces

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Acta Mathematica Sinica,English Series 2024年第2期40卷 425-434页

作者： jing Jun han Yu Jie LUO Shanghai Center for Mathematical Sciences Fudan UniversityJiangwan CampusShanghai 200438P.R.China Department of Mathematics Johns Hopkins UniversityBaltimoreMD 21218USA

Following Shokurov's idea,we give a simple proof of the ACC conjecture for minimal log discrepancies for surfaces.

关键词： Ascending chain condition minimal log discrepancies minimal model program surface

Comparisons and optimization of two absorption chiller types by considering heat transfer area,exergy and economy as single-objective functions

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Clean Energy 2024年第1期8卷 55-65页

作者： Yida Qiu jingkun Wang jing han Yuzhu chen Jun Wang Peter D.Lund Management School University of LiverpoolLiverpool L693BXUK Power China Huadong Engineering Corporation Limited No.201 Gaojiao RoadHangzhou 311122China Key Laboratory of Solar Energy Science and Technology in Jiangsu Province Southeast UniversityNo 2 Si Pai LouNanjing210096China School of Science Aalto UniversityPO Box 15100FI-00076Aalto(Espoo)Finland

Absorption cooling technology is an environmentally friendly method to generate continuous chilled water making use of multiple thermal sources,such as waste heat and renewable thermal *** this study,two absorption chillers(nominal capacity of 400 kW)with series and parallel connections are *** research the ideal configuration of chillers after thermodynamic analysis,the structures of the chillers are optimized using the particle swarm optimization algorithm by considering the heat transfer area(HTA),exergy efficiency and total annual cost as single-objective *** impact of temperature differences between external and internal flows,heat exchanger efficiencies and the solution allocation ratio is *** optimized HTA,coefficient of perform-ance,exergy efficiency and total annual cost are 149.0 m^(2),1.56,29.44%and$229119 for the series-connected chiller,and 146.7 m^(2),1.59,31.45%and$234562 for the parallel-connected type,*** the lowest HTA condition,compared with the reference simulation results,the energy and exergy performances are improved,while the annual total cost is *** annual total cost is highest when maximizing the exergy efficiency,which is attributed to the increase in the *** operating cost accounts for 27.42%(series type)and 26.54%(parallel type)when the annual cost is the lowest.

关键词： absorption chiller series/parallel-connected temperature difference parameters solution allocation ratio

Experimental and numerical study on dynamic mechanical behaviors of shale under true triaxial compression at high strain rate

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International Journal of Mining Science and Technology 2024年第2期34卷 149-165页

作者： Xiaoping Zhou Linyuan han jing Bi Yundong Shou School of Civil Engineering Wuhan UniversityWuhan 430072China College of Civil Engineering Guizhou UniversityGuiyang 550025China

High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing *** effectively extract shale gas,it is important to understand the dynamic mechanical properties of *** experiments on shale subjected to true triaxial compression at different strain rates are first conducted in this *** dynamic stress-strain curves,peak strain,peak stress and failure modes of shale are *** results of the study indicate that the intermediate principal stress and the minor principal stress have the significant influence on the dynamic mechanical behaviors,although this effect decreases as the strain rate *** characteristics of compression-shear failure primarily occur in shale subjected to triaxial compression at high strain rates,which distinguishes it from the fragmentation characteristics observed in shale under dynamic uniaxial ***,a numerical three-dimensional Split Hopkinson Pressure Bar(3D-SHPB),which is established by coupling PFC3D and FLAC3D methods,is validated to replicate the laboratory characteristics of *** dynamic mechanical characteristics of shale subjected to different confining stresses are systematically investigated by the coupling PFC3D and FLAC3D *** numerical results are in good agreement with the experimental data.

关键词： Dynamic behaviors True triaxial compression High strain rates Dynamic failure mechanism PFC3D-FLAC3D coupled method