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Effects of Optimized Root Water Uptake Parameterization Schemes on Water and Heat Flux Simulation in a Maize Agroecosystem

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Journal of Meteorological Research 2017年第2期31卷 363-377页

作者： fu cai Huiqing MING Na MI Yanbing XIE Yushu ZHANG Rongping LI Institute of Atmospheric Environment China Meteorological Administration Shenyang 110166 Liaoning Province Meteorological Service Center Shenyang 110166 Institute of Meteorological Science of Liaoning Province Shenyang 110166

As root water uptake（RWU）is an important link in the water and heat exchange between plants and ambient air,improving its parameterization is key to enhancing the performance of land surface model *** different types of RWU functions have been adopted in land surface models,there is no evidence as to which scheme most applicable to maize farmland *** on the 2007–09 data collected at the farmland ecosystem field station in Jinzhou,the RWU function in the Common Land Model（Co LM）was optimized with scheme options in light of factors determining whether roots absorb water from a certain soil layer（W_x）and whether the baseline cumulative root efficiency required for maximum plant transpiration（W_c）is *** sensibility of the parameters of the optimization scheme was investigated,and then the effects of the optimized RWU function on water and heat flux simulation were *** results indicate that the model simulation was not sensitive to W_x but was significantly impacted by W_*** the original model,soil humidity was somewhat underestimated for precipitation-free days;soil temperature was simulated with obvious interannual and seasonal differences and remarkable underestimations for the maize late-growth stage;and sensible and latent heat fluxes were overestimated and underestimated,respectively,for years with relatively less precipitation,and both were simulated with high accuracy for years with relatively more *** optimized RWU process resulted in a significant improvement of Co LM’s performance in simulating soil humidity,temperature,sensible heat,and latent heat,for dry *** conclusion,the optimized RWU scheme available for the Co LM model is applicable to the simulation of water and heat flux for maize farmland ecosystems in arid areas.

关键词： root water uptake land surface model water flux heat flux maize agroecosystem

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Effect of Magnesium on Inclusion Formation in Ti-Killed Steels and Microstructural Evolution in Welding Induced Coarse-Grained Heat Affected Zone

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Journal of Iron and Steel Research International 2009年第1期16卷 69-74页

作者： CHAI Feng YANG cai-fu SU Hang ZHANG Yong-quan XU Zhou Central Iron and Steel Research Institute Beijing 100081 China Shanghai Jiaotong University Shanghai 200030 China

Effects of Mg on the chemical component and size distribution of Ti-bearing inclusions favored grain refinement of the welding induced coarse-grained heat affected zone （CGHAZ）, with enhanced impact toughness in Ti-killed steels, which were examined based on experimental observations and thermodynamic calculations. The results indicated that the chemical constituents of the inclusions gradually varied from the Ti-O＋Ti-Mg-O compound oxide to the Ti-Mg-O＋MgO compound oxide and the single-phase MgO, as the Mg content increased from 0.002 3M to 0.006%. A trace addition of Mg （approximately 0. 002%） led to the refinement of Ti-bearing inclusions by creating the Ti-Mg-O compound oxide and provided favorable size distribution of the inclusions for acicular ferrite transformation with a high nucleation rate in the CGHAZ, and a high volume fraction of acicular ferrite was obtained in the CGHAZ with enhanced impact toughness. Otherwise, a high content of Mg （approximately 0. 006%） produced a single-phase MgO, which was impotent to nucleate an acicular ferrite, and a microstructure comprised of a ferrite side plate and a grain boundary ferrite developed in the CGHAZ. The experimental results were confirmed by thermodynamic calculations.

关键词： non-metallic inclusion magnesium acicular ferrite coarse-grained heat affected zone (CGHAZ)

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Effects of Cu on Corrosion Resistance of Low Alloyed Steels in Acid Chloride Media

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Journal of Iron and Steel Research International 2014年第6期21卷 619-624页

作者： Hang SU Xiao-bing LUO cai-fu YANG Feng CHAI Hao LI Institute for Engineering Steel Central Iron and Steel Research Institute

The corrosion resistance of two kinds of low alloyed steels was studied according to the test procedures for qualification of corrosion resistant steel for cargo oil tanks issued by International Maritime Organization. The results indicated that the addition of Cu improved the corrosion resistance of the NS-D36 steel to more than three times that of the conventional D36 steel in the strong acid solution containing chloride （10% NaC1, pHi0.85）. The anodic polarization behavior of the copper-bearing steel was studied by polarization curves and electrochemical impedance spectroscopy （EIS）, and alloying element Cu showed beneficial effects including an active potential range, low current density and high transfer resistance of electric charge. The rust layer was analyzed by scanning electron microscopy （SEM） and Auger electron spectroscopy （AES）, and the results pointed out that the mechanism of copper＇s benefi cial effects was based on the suppression of anodic dissolution by metallic copper re-deposition on the steel surface immersed in the strong acid chloride media.

关键词： low alloyed steel acid chloride media corrosion copper deposition

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Hot roll bonding between commercially pure titanium and high-strength low-alloy steel using Fe interlayer

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Journal of Iron and Steel Research International 2019年第10期26卷 1126-1136页

作者： Xi-yang Chai Gang Chen Feng Chai Tao Pan Zhi-gang Yang cai-fu Yang Department of Structural Steel Central Iron and Steel Research InstituteBeijing 100081China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Hot roll bonding was carried out between commercially pure titanium TA2 and high-strength low-alloy steel Q390 using no interlayer and Fe interlayer at temperatures of 850,900,950 and 1000℃with a total reduction ratio of 86.7%.Interfacial microstructure and bonding property of clad plates were investigated by electron microscopy and shear *** results showed that with the increase in heating temperature,the shear strength of titanium clad steel plates decreases *** with that of titanium clad steel plates with no interlayer,inserting Fe interlayer between titanium and steel can improve the shear strength at 850 and 900℃but deteriorate the shear strength at 950 and 1000℃.The reason for this consequence was that Fe interlayer prevented the reaction diffusion of C in titanium to form a thinner TiC layer at 850 and 900℃,while Fe interlayer promoted the reaction diffusion of Fe in titanium to generate thicker Fe2Ti and FeTi intermetallic compound layers at 950 and 1000℃.

关键词： Titanium clad steel plate Fe interlayer TiC Intermetallic compound Hot roll bonding

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Precipitation Behavior of V-N Microalloyed Steels during Normalizing

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Journal of Iron and Steel Research International 2015年第11期22卷 1037-1042页

作者： Tao PAN Xi-yang CHAI Jin-guang WANG Hang SU cai-fu YANG Division of Structural Steels Central Iron and Steel Research Institute Division of Equipment Construction China Sinopec Engineering Incorporation

The precipitation behavior of V-N microalloyed steel during normalizing process was studied by physicochemical phase analysis and transmission electron microscopy（TEM）. The effect of precipitation behavior on mechanical properties was investigated by theoretical calculations. The results showed that 32.9% of V（C,N） precipitates remained undissolved in the austenite during the soaking step of the normalizing process. These precipitates prevented the growth of the austenite grains. During the subsequent cooling process, the dissolved V（C,N） re-precipitated and played a role in precipitation strengthening. The undissolved V（C,N） induced intragranular ferrite nucleation and refined the ferrite grains. Consequently, compared with hot-rolled steel, the normalized steel exhibited increased grain-refining strengthening but diminished precipitation strengthening, leading to an improvement of the impact energy at the expense of about 40 MPa yield strength.

关键词： normalizing V-N microalloyed steel precipitation strengthening grain-refining strengthening

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汽车零部件阳光模拟试验方法浅析

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环境技术 2024年第2期42卷 105-110页

作者：叶岗孙福才王钊桐傅童陈建彬李成森威凯检测技术有限公司广州510663

随着汽车工业的快速发展,对汽车零部件的质量和性能要求越来越高。为了测试汽车零部件在自然阳光环境下的性能表现,评估其耐候性、耐久性和安全性等方面的性能,阳光模拟试验成为了一种重要的测试方法。本文主要介绍汽车零部件阳光模拟... 详细信息

随着汽车工业的快速发展,对汽车零部件的质量和性能要求越来越高。为了测试汽车零部件在自然阳光环境下的性能表现,评估其耐候性、耐久性和安全性等方面的性能,阳光模拟试验成为了一种重要的测试方法。本文主要介绍汽车零部件阳光模拟试验的设备结构、测试方法等方面,并依据设备特点着重分析各试验方法的测试要求及试验特点。

关键词：汽车零部件太阳光模拟

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Chemistry and Process Optimization of V-Microalloyed N80-Class Seamless Casing Tube

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Journal of Iron and Steel Research International 2010年第3期17卷 72-78页

作者： PAN Tao YANG cai-fu MA Yue XUE Dong-mei ZHANG Yong-quan Division for Structural Materials Central Iron and Steel Research Institute Beijing 100081 China

The complex effects of different nitrogen （N） contents and thermal routines on the microstructure and mechanical properties of 33Mn2V steels for N80-Class seamless casing tube application were investigated using Gleeble simulation technique. The results showed that the N additions of 0. 014 %- 0. 021 % in the steels for the in-line normalization process （ILNP） increased the strength while the toughngss remained at a high level as compared with the steel with N content of 0. 005 %. It was also revealed that the N addition of 0. 021%could enhance the performance combination of strength and toughness in the steels by using 700 ℃ as the cooling interrupted temperature （CIT） for the non in-line normalizing process （NILNP）. It was further evidenced that the toughness was improved at expense of strength to some degree in all the steels by decreasing reheating temperature for the ILNP, while an increase of CIT for NILNP severely impaired the toughness and slightly improve the strength in the high-N steel with N content of 0. 021%. This can be attributed to the dissolution and precipitation behavior of V（C,N）. The optimization of V （C,N） precipitation could be achieved by enhancing N. The precipitation of V（C, N） in austenite was promoted by cooling to a certain temperature lower than the A,1 for the ILNP. The V（C,N） particles formed in austenite contrib- uted to grain refinement by the VN-induced nucleation of intragranular ferrite, but as a result the effect of precipitation on strengthening would become weaker due to a decrease of the precipitation of V in ferrite.

关键词： seamless tube in-line normalizing V-N microalloying reheating mechanical properties Gleeble simulation

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Prediction of Deformation-Induced γ→α Transformation of 16MnNb Steel

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Journal of Iron and Steel Research International 2003年第4期10卷 59-62页

作者： YUN Bing PAN Hao YANG cai-fu SHEN Jun-chang SU Hang Central Iron and Steel Research Institute

Based on the nucleation and growth theory together with the influence of deformation on driving force and nucleation site,a numerical model was developed for predicting deformation-induced transformation(DIT).The numerical results of DIT of 16 MnNb steel was presented and compared with the experimental *** calculated results are in agood agreement with the experimental ones,and the best calculated result is obtained when the constantα=0.25 for steel 16 MnNb.

关键词： 16MnNb steel phase transformation computer simulation microstructure deformation

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Context-Aware Usage-Based Grid Authorization Framework

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Wuhan University Journal of Natural Sciences 2006年第6期11卷 1736-1740页

作者： CUI Yongquan HONG Fan fu cai College of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China

Due to inherent heterogeneity, multi-domain characteristic and highly dynamic nature, authorization is a critical concern in grid computing. This paper proposes a general authorization and access control architecture, grid usage control （GUCON）, for grid computing. It＇s based on the next generation access control mechanism usage control （UCON） model. The GUCON Framework dynamic grants and adapts permission to the subject based on a set of contextual information collected from the system environments; while retaining the authorization by evaluating access requests based on subject attributes, object attributes and requests. In general, GUCON model provides very flexible approaches to adapt the dynamically security request. GUCON model is being implemented in our experiment prototype.

关键词： context-aware access control usage control (UCON)

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Optical Properties of Cirrus Transition Zones over China Detected by CALIOP

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Journal of Meteorological Research 2017年第3期31卷 576-585页

作者： Hongke cai Yunfei fu Quanliang CHEN Xiao FENG Xin TIE Ranting TAO Kepiao XU School of Atmospheric Science Chengdu University of Information Technology/Plateau Atmospheric and Environment Laboratory of Sichuan Province School of Earth and Space Sciences University of Science and Technology of China

A transition zone near cirrus lateral boundaries can be detected by CALIOP （cloud-aerosol lidar with orthogonal polarization）. In the present study, for such transition zones over China, a number of optical properties, such as the backscatter coefficient and depolarization ratio, showed transitional characteristics between cirrus and clear sky. The stepped horizontal profile showed sharp changes in particle number and morphology between cirrus clouds and clear sky. The color ratio, however, was unable to show cirrus transition features because of the low signal-to-noise ratio. Typical ice particles presented a color ratio of 0.55-1.25 and a depolarization ratio of greater than 0.12, which were significantly higher than those of clear sky. Therefore, optical properties in transition took the form of stepwise hori- zontal profiles. The proportion of typical-featured particles also demonstrated a stepped horizontal profile similar to the optical characteristics, but the relationship between the proportion and the optical characteristics was not uniform in the cirrus clouds, transition zone, and clear sky. Therefore, the optical changes in the transition zone were caused by not only the change in particle concentration, but also the change in the particles themselves. The probability dens- ity distribution of the transition-zone widths showed a positive skewness distribution, and transition zones with widths of 3-5 km occurred most frequently. Overall, transition-zone width decreased with increasing temperature and increased with increasing vertical and horizontal wind speeds. This trend demonstrated independence with the direc- tion of the vertical and horizontal winds. These observations implied that the transitional features were caused by ma- terial exchange, such as entrainment and turbulent transport, near the cirrus lateral boundaries, and by the phase trans- formation of particles, such as sublimation.

关键词： cirrus transition zone lidar temperature wind speed

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