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NUMERICAL SIMULATION OF FLOW OF PULP FIBER SUSPENSIONS IN STOCK PUMP WITH SEMI-OPEN IMPELLER

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 546-549页

作者： li Hong yuan Shouqi liu Weiwei Research Center of Fluid Machinery Engineering and Technology Jiangsu University Zhenjiang 212013 China

The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction chamber, front board, semi-impeller and volute casing for the first time. The pseudo-fluid model and the k-ε turbulent model are modified. Phase coupled SIMPLE algorithm is applied to make pressure-velocity correction equation. Based on the results of the numerical simulation, the distribution of velocity, pressure and density of liquid and particle phase are compared and analyzed. The flow analysis in the tip between front board and impeller is emphasized, which reflects the advantage of semi-open impeller when it transports 2-phase medium. This calculation result will be helpful for the design of pump impeller and the establishment of design method of centrifugal stock pump.

关键词： Centrifugal stock pump Pulp fiber suspensions Numerical simulation

Pricing in combinatorial double auction-based grid allocation model

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 59-65页

作者： li li liu yuan-an liu Kai-ming MA Xiao-lei YANG Ming Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

This article proposes a novel grid resource allocation model, in which the users and the grid service providers participate in the combinatorial double auction for the resource allocation. To obtain the detailed resource allocation status and the price information, a novel pricing algorithm is designed for the allocation model. Simulation results demonstrate that the proposed algorithm completes the resource allocation and pricing efficiently, and exhibits incentive compatible characteristic. Moreover, users with the higher average price and providers with the lower average price get compensation during the pricing process.

关键词： grid combinatorial double auction resource allocation pricing

Temperature-induced dissociation reaction and dynamics of light-harvesting complex II isolated from purple photosynthetic bacterium ***

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Chinese Science Bulletin 2007年第8期52卷 1029-1035页

作者： FENG Juan li XueFeng liu yuan School of life Science and Technology University of Electronic Science & Technology of China Chengdu 610054 China

Steady-state absorption spectroscopy,circular dichroism,and resonance Raman spectroscopy have been used to investigate the thermal stability of LH2 complex isolated from purple photosynthetic bacterium *** results show that:1)upon increasing the temperature,a transition from B800 and B850 to free bacteriochlorophyll(B780)happens;2)a gradual decrease and disappearance of CD signal in visible region occur;3)a shift of the frequency,belonging to C==C and C—C stretching vibration,to higher wavenumber takes *** is suggested that LH2 complex can be dissociated in the presence of B800,B850 and carotenoids ***-exponential fitting on the dynamic decay curves gives the apparent time constants of hundreds of minutes for various pigments.

关键词：紫色光合细菌沼泽红假单胞菌温度诱导离解反应反应动力学捕光配合物Ⅱ

Time and Temperature Dependence of the Structural Evolution for Polyamide 1012

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Chinese Journal of Polymer Science 2020年第9期38卷 993-998,I0007页

作者： Xin-Ran liu Yu Wang li-yuan liu Xia Dong Du-Jin Wang CAS Key Laboratory of Engineering Plastics CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China

The rheological property evolution of polyamide 1012(PA1012)in the isothermal process in molten state has been *** results show that the viscosity increases and crosslinking reaction occurs simultaneously together with the increase of temperature,thus causing the variation of storage modulus(G')and loss modulus(G")in the repeated frequency sweeps with residual *** research has pointed out that the superposition is valid for monitoring the complex behavior composed of the viscosity increasing and crosslink occurring process by tracing the variation behavior of the crossover points of G'and G"with time,revealing the same time-temperature dependence of the two reactions in the isothermal process.A normalized master curve has been proposed to describe the melt behavior at a given temperature.

关键词： Polyamide 1012 Rheology Crosslinking Viscosity increasing Time-temperature superposition

Molecular Characterization of Three Ethylene Responsive Element Binding Factor Genes from Cotton

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Journal of Integrative Plant Biology 2010年第5期52卷 485-495页

作者： Long-Guo Jin Hui li Jin-yuan liu Laboratory of Molecular Biology and MOE Laboratory of Protein Science Department of Biological Sciences and Biotechnology TsinghuaUniversity Beijinq 100084 China

Ethylene-responsive factors （ERFs） are important regulators of plant gene expression. In this study, three novel ERF genes, GhERF2, GhERF3 and GhERF6, were isolated from cotton （Gossypium hirstum） using rapid amplification of cDNA ends-polymerase chain reaction. Transient expression analysis using GhERF-green fluorescent protein fusions showed that these three proteins were targeted to the nucleus. Fusion proteins consisting of GhERF2, GhERF3 or GhERF6 coupled to the GAL4 DNA binding domain strongly activated transcription in yeast. Furthermore, GhERF6 was shown to be able to bind specifically to GCC boxes using a particle bombardment assay in tobacco cells. Semi-quantitative reverse transcription-polymerase chain reaction revealed that GhERF2 and GhERF3 are constitutively expressed in all organs, while GhERF6 is only constitutively expressed in vegetative organs. When plants were treated with ethylene, abscisic acid, salt, cold and drought, the transcripts of GhERF2, GhERF3 and GhERF6 were rapidly induced to high levels. Promoter analysis also indicated that the 5＇ upstream regions of the three genes possess elements induced by these physiological and environmental factors. Collectively, our data suggest that GhERF2, GhERF3 and GhERF6 might function as positive trans-acting factors in the plant responses to ethylene, abscisic acid and other stresses and provide useful clues for further research into the mechanism of them in regulating cotton multiple stress responses.

关键词： PLANT gene expression COTTON POLYMERASE chain reaction ETHYLENE ABSCISIC acid

Power control for two-way amplify-and-forward relaying over Rayleigh fading channels

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第4期12卷 280-287页

作者： Xing-zheng li yuan-an liu Gang XIE Pan-liang DENG Fang liu School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

We propose two novel power control policies for a two-way amplify-and-forward (AF) relaying system,in which each node (two sources and one relay) is assumed to operate under bothminimum and peak power *** the exploitation of instantaneous channel gains,the first policy can maximize the sum rate of the ***,the instantaneous channel gains may be unavailable in a rapid time-varying system,where the first policy is ***,a robust power control policy which requires only mean channel gains is proposed to maximize the upper bound of the average sum rate,and the properties of this policy are *** results show that,by comparison with the policy in which all the nodes use their peak transmit power,the proposed power control policies can provide considerable system performance ***,the performance difference between the two proposed policies is negligible when the relay is close to one source.

关键词： Amplify-and-forward (AF) relaying Power control Two-way relay channel Bidirectional relaying Cooperative communication

Clustering-triggered Emission of Cellulose and Its Derivatives

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Chinese Journal of Polymer Science 2019年第4期37卷 409-415,I0007页

作者： lin-lin Du Bing-li Jiang Xiao-Hong Chen Yun-Zhong Wang lin-Min Zou yuan-li liu Yong-Yang Gong Chun Wei Wang-Zhang yuan Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials Ministry of EducationCollege of Materials Science and EngineeringGuilin University of Technology College of Pharmacy Guilin Medical University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University

In recent years, nonconventional luminogens free of aromatic groups have attracted extensive attention due to their academic importance and promising wide applications. Whilst previous studies generally focused on fluorescence from aliphatic amine or carbonylcontaining systems, less attention has been paid to room temperature phosphorescence(RTP) and the systems with predominant oxygen functionalities. In this work, photophysical properties of the polyhydroxy polymers, including microcrystalline cellulose(MCC), 2-hydroxyethyl cellulose(HEC), hydroxypropyl cellulose(HPC), and cellulose acetate(CA), were studied and compared. While MCC,HEC, and HPC solids showed bright emission alongside distinct RTP, CA demonstrated relatively low intensity of solid emission without noticeable RTP. Their emissions were explained in terms of the clustering-triggered emission(CTE) mechanism and conformation rigidification. Additionally, on account of its intrinsic emission, concentrated HEC aqueous solution could be used as the probe for the detection of 2,4,6-trinitrophenol(TNP).

关键词： Cellulose Nonconventional luminogens Room temperature phosphorescent Clustering-triggered emission

Microstructure and Corrosion Behavior of Friction Stir Welded Al Alloy Coated by In Situ Shot-Peening-Assisted Cold Spray

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Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 172-182页

作者： Hua Zhang Chang-Yu Zhao Qi-Long Guo Rui-Sheng Yang li-yuan liu San-Bao lin School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China Beijing Institute of Astronautical Systems and Engineering Beijing 100076China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

To improve the corrosion resistance of friction stir welded(FSW)joints,in situ shot-peening-assisted cold spray coating was applied to the surface of FSW *** microstructure and corrosion behavior of the coatings were *** results showed that a dense coating was obtained by cold spraying ***,the use of in situ shot-peeningassisted technology significantly reduced the porosity of the coating,which has a positive impact on the microstructure and the mechanical *** corrosion tests showed that the coating aff ected positively on the corrosion *** the coated surface,the craters caused by shot-peening particles were corroded in the form of exfoliation corrosion,while the exposed particles were corroded in the form of intercrystalline *** work provides a new approach to the corrosion protection of FSW joints.

关键词： Aluminum alloy coating Cold spray Friction stir welding In situ shot-peening Intergranular corrosion

Mitigation of greenhouse gases released from mining activities:A review

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International Journal of Minerals,Metallurgy and Materials 2021年第4期28卷 513-521页

作者： li-yuan liu Hong-guang Ji Xiang-feng Lü Tao Wang Sheng Zhi Feng Pei Dao-lu Quan Beijing Key Laboratory of Urban Underground Space Engineering University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Department of Energy and Mineral Engineering EMS Energy Institute and G3 CenterPennsylvania State UniversityUniversity ParkPA 16802USA

Climate changes that occur as a result of global warming caused by increasing amounts of greenhouse gases(GHGs)released into the atmosphere are an alarming *** greenhouse gas emissions is critically important for the current and future status of mining *** mining industry is one of the significant contributors of greenhouse *** essence,anthropogenic greenhouse gases are emitted directly during the actual mining and indirectly released by the energy-intensive activities associated with mining equipment,ore transport,and the processing ***,we reviewed both direct and indirect GHG emissions to analyze how mining contributes to climate *** addition,we showed how climate change impacts mineral *** assessment was performed using a GHG inventory model for the gases released from mines undergoing different product life *** also elucidate the key issues and various research outcomes to demonstrate how the mining industry and policymakers can mitigate GHG emission from the mining *** review concludes with an overview of GHG release reduction and mitigation strategies.

关键词： greenhouse gas emission greenhouse gas reduction mining climate change life cycle assessment mitigation strategy