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Influence of Temperature on the Protectiveness and Morphological Characteristics of Calcareous Deposits Polarized by Galvanostatic Mode

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Acta Metallurgica Sinica(English Letters) 2014年第1期27卷 131-139页

作者： Chengjie Li min du Jing Qiu Jing Zhang Congjie Gao The Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationCollege of Chemistry and Chemical EngineeringOcean University of China

The influence of temperature on calcareous deposits formed under galvanostatic polarization mode was studied. The deposition was monitored by electrochemical impedance spectrum, and a supplementary loop in Nyquist diagram at high frequency was found to be an indicator of deposits precipitation with sufficient protection at above 20 ~C. An exponential increase of protectiveness with temperature was observed, which was quantified by linear polarization resistance technique. Observation by scanning electron microscope and X-ray diffraction analyses demonstrated that the critical temperature of calcium carbonate crystal form transition ranged from 15 to 20 ℃. Calcite formed below 15 ℃, while aragonite precipitated at above 20 ℃.

关键词： Calcareous deposits Temperature Galvanostatic Cathodic protection

Rhus laccase catalysis and product characterization of 1,2-dimethoxyphenol in organic solutions

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Chinese Chemical Letters 2008年第3期19卷 333-336页

作者： Yun Yang Wan Yu min du Tetsuo Miyakoshi State Key Laboratory of Petroleum Resources and Prospecting Faculty of Natural Resources and Information TechnologyChina University of Petroleum Beifing 102249 China Department of Industrial Chemistry Meifi University Higashi-mita Tama-ku Kawasaki 214 Japan School of Resource and Environment Science Wuhan University Wuhan 430079 China

Dimethoxyphenol was a widely used substrate in determination of laccases activity. It was surprised, however, that the products of it had not been completely determined until now. Studies were thus conducted on Rhus laccase （RL） and immobilized Rhus laccase （IRL）-catalyzed oxidation of 2,6-dimethoxyphenol （DMP） in water-organic solvent systems. Only one product, 3,3′,5,5′- tetramethoxy-1 ,1′-biphenyl-4,4′-diol （TMBP）, was produced by RL catalysis, and it was thoroughly characterized by FT-IR, NMR and GC-MS, etc.

关键词： Rhus laccase Laccase-catalyzed oxidation Organic solvents 2,6-Dimethoxyphenol

Retinoic acid inhibits white adipogenesis by disrupting GADD45A-mediated Zfp423 DNA demethylation

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Journal of Molecular Cell Biology 2017年第4期9卷 338-349页

作者： Bo Wang Xing Fu Mei-Jun Zhu min du Advanced Innovation Center for Food Nutrition and Human Health China Agricultural University Beijing 100094 China Department of Animal Sciences Washington State University Pullman WA 99164 USA School of Food Science Washington State University Pullman WA 99164 USA

Retinoic acid （RA）, a bioactive metaboUte of vitamin A, is a critical mediator of cell differentiation. RA blocks adipogenesis, but mechanisms remain to be established. ZFP423 is a key transcription factor maintaining white adipose identity. We found that RA inhibits Zfp423 expression and adipogenesis via blocking DNA demethylation in the promoter of Zfp423, a process mediated by growth arrest and DNA-damage-inducible protein alpha （GADD45A）. RA induces the partnering between retinoic acid receptor （PAR） and tumor suppressor inhibitor of growth protein 1 （ING1）, which prevents the formation of GADD45A and ING1 complex necessary for locus-specific Zfp423 DNA demethylation. In vivo, vitamin A supplementation prevents obesity, downregulates Godd45a expression, and reduces GADD45A binding and DNA demethylation in the Zfp423 promoter. Inhibition of Zfp423 expres- sion due to PA contributes to the enhanced brown adipogenesis. In summary, PA inhibits white adipogenesis by inducing PAR and ING1 interaction and inhibiting Godd45a expression, which prevents GADD45A-mediated DNA demethylation.

关键词： vitamin A retinoic acid Gadd45α adipogenesis demethylation Zfp423

Coupling Thermomechanical and Microstructural FE Analysis in Plate Rolling Process

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Journal of Iron and Steel Research International 2008年第4期15卷 42-50页

作者： LI Xue-tong WANG min-ting du Feng-shan College of Mechanical Engineering Yanshan University Qinhuangdao 066004 Hebei China

Using three-dimensional rigid-viscoplastic finite element method （FEM）, a coupling multivariable numerical simulation model for steel plate rolling has been established based on the physical metallurgy microstructural evolution rule and experiential equations. The effects of reduction, deformation temperature, and rolling speed on the deformation parameters and microstructure in plate rolling were investigated using the model. After a typical rolling process of steel plate 16Mn is simulated, the strain, temperature, and microstructure distributions are presented, as well as the ferrite grain transformation during the period of cooling. By comparing the calculated ferrite grain sizes with measured ones, the model is validated.

关键词： hot rolling plate FEM microstructure coupling

Asymmetric Fuzzy Control of a Positive and Negative Pneumatic Pressure Servo System

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Chinese Journal of Mechanical Engineering 2017年第6期30卷 1438-1446页

作者： Gang Yang Jing-min du Xiao-Yun Fu Bao-Ren Li School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074China

The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative （PID） controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mecha- nisms employing the error and change in error of the controlled variable as input parameters, the current cham- ber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the pro- posed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consis- tent control performance across the scope of work （2-140 kPa）. The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.

关键词： Pneumatic pressure control system Positiveand negative pressure Asymmetric control Fuzzy control

Performance evaluation of a bubble generator and a bubble separator designed for the gas removal system of a small thorium molten salt reactor

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Chinese Journal of Chemical Engineering 2020年第5期28卷 1250-1259页

作者： Licheng Sun Liang Zhao min du Zhengyu Mo Jiguo Tang Guo Xie State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource&HydropowerSichuan UniversityChengdu 610065China

In the present study, a bubble generator and a bubble separator were designed and evaluated for an independent off-gas removal system of a small thorium molten salt reactor(TMSR) with reference to the design of the Oak Ridge National Laboratory(ONRL). The bubble generator employed a Venturi tube as its main body owing to its simplicity and highly reliable structure. A centrifugal separator was used as the bubble separator, taking advantage of the kinetic energy of fluid to create a centrifugal force to separate gas bubbles from the mixture flow. Both the bubble generator and the separator were demonstrated to have good potential to meet the performance requirements of an off-gas removal system for a small TMSR. With water and air as the working fluids, for the final designs of the two key pieces of equipment, a liquid flow rate exceeding 15 m3·h-1 can essentially make their performance meet the requirements of the off-gas removal system in terms of the average size of the generated bubbles and gas separation efficiency.

关键词： Bubble generator Venturi Bubble separator Off-gas removal TMSR

Study on Hydrography and Small-Scale Process over Zhoushan Sea Area

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Journal of Ocean University of China 2015年第5期14卷 829-834页

作者： WU He du min WANG Xiaoyong MENG Jie National Ocean Technology Center

This paper mainly analyzes the tidal characteristics and small-scale mixing process near Zhoushan Islands. First, the spectral analysis and wavelet analysis are adopted for the measured tide level data and tidal current data from the Zhoushan sea area, which indicate that the main tidal cycle near Hulu Island and Taohua Island is semi-diurnal cycle, the diurnal cycle is subordinate. Both their intensities are changed periodically, meanwhile, the diurnal tide becomes stronger when semi-diurnal tide becomes weak. The intensity of baroclinie tidal current weakens at first and then strengthens from top to bottom. Then, in this paper, the Gregg-Henyey （G-H） parameterization method is adopted to calculate the turbulent kinetic energy dissipation rate based on the measured temperature and tidal current data. The results of which shown that the turbulent kinetic energy dissipation rate around Hulu Island is higher than that around Taohua Island. In most cases, the turbulent kinetic energy dissipation rate during spring tide is larger than that during the neap tide; the turbulent kinetic energy dissipation rate in the surface layer and the bottom layer are higher than that in the intermediate water; the changes of turbulent kinetic energy dissipation rate and tidal current are basically synchronous The modeled turbulent kinetic energy dissipation rate gets smaller with the increase of the stratification, however, gets larger with the increase of shearing.

关键词： tidal characteristics parameterization method turbulent kinetic energy dissipation rate

Investigation of the stable and the metastable liquidus miscibility gaps in Fe–Sn and Fe–Cu binary systems

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International Journal of minerals,Metallurgy and Materials 2019年第11期26卷 1427-1435页

作者： Jiang-tao Gao Chang-rong Li Cui-ping Guo Zhen-min du School of Materials Science and Engineering University of Science and Technology Beijing

Two kinds of experimental methods were tried in the present work:(i)the powder metallurgy method combined with differential thermal analysis(DTA)to determine the metastable liquidus miscibility gap for a Fe–Cu binary system and(ii)the high-temperature melting method combined with isothermal treatment to determine the stable liquidus miscibility gap for a Fe–Sn binary *** experimental method was adopted according to the characteristics of the liquidus miscibility gap of the specific *** the powder metallurgy method,a uniform microstructure morphology and chemical composition was obtained in the DTA specimen,and the phase-separation temperature of the supercooled metastable liquid was *** isothermal treatment was applied for the samples inside the stable liquidus miscibility gap;here,equilibrated compositions were reached,and a layered morphology was formed after rapid *** liquid miscibility gaps of the Fe–Cu and Fe–Sn binary systems were measured,and the peak temperatures of the corresponding miscibility gaps were determined to be about 1417°C at x(Cu)=0.465 at%and 1350°C at x(Sn)=0.487 at%,*** the basis of the experimental results,both the Fe–Cu and the Fe–Sn binary systems were thermodynamically assessed.

关键词： binary systems miscibility gap differential thermal analysis(DTA) metastable state

Inhibition of ROS elevation and damage to mitochondrial function prevents lead-induced neurotoxic effects on structures and functions of AFD neurons in Caenorhabditis elegans

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Journal of Environmental Sciences 2012年第4期24卷 733-742页

作者： Qiuli Wu Peidang Liu Yinxia Li min du Xiaojuan Xing Dayong Wang Key Laboratory of Environmental Medicine Engineering in ministry of Education Medical School of Southeast UniversityNanjing 210009China Department of Biochemistry and Molecular Biology Medical School of Southeast UniversityNanjing 210009China

Here we investigated the possible roles of oxidative stress in the formation of decreased thermotaxis to cultivation temperature in lead （Pb）-exposed nematodes Caenorhabditis elagans. Exposure to Pb at the examined concentrations decreased thermotaxis behaviors, and induced severe deficits in the structural properties of AFD sensory neurons. Meanwhile, Pb exposure caused the induction of severe oxidative damage, reactive oxygen species （ROS） production, and mitochondrial dysfunction in young adults. Moreover, pre-treatment with the antioxidants dimethyl sulfoxide （DMSO）, ascorbate and N-acetyl-L-cysteine （NAC）, used to inhibit both the ROS elevation and the mitochondrial dysfunction caused by Pb exposure, at the L2-1arval stage prevented the induction of oxidative damage and the formation of severe deficits in thermotaxis and structural properties of AFD sensory neurons in Pb-exposed young adults. Therefore, the formation of oxidative stress caused by Pb exposure may be due to both the induction of ROS elevation and damage to mitochondrial function, and oxidative stress may play a key role in inducing the neurotoxic effects on the structures and function of AFD sensory neurons in Pb-exposed nematodes.

关键词： thermotaxis lead exposure oxidative stress AFD sensory neuron Caenorhabditis elegans