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Studies of internal magnetic fluctuation in the HL-1M tokamak

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核聚变与等离子体物理 2005年第1期25卷 42-48页

作者： zhenGYong-zhen DINGxuan-tong LIWen-zhong SouthwesternInstituteofPhysics Chengdu610041

The transport of runaway electrons in a hot plasma can be comparatively easily measured in steady state or perturbation experiments, which provide runaway electron diffusivity Dr. The diffusivity can be interpreted in terms of the magnetic fluctuation level. The runaway electron diffusion coefficient is determined by internal magnetic fluctuations. The internal magnetic fluctuations level （r/BT） is estimated to be about （2～4） ×10-4 in the HL-1M plasma. The results demonstrate the effectiveness of using runaway transport techniques for determining internal magnetic fluctuations. A profile of the magnetic fluctuation level in the HL-1M tokamak can be estimated from Dr.

关键词：内禀磁波动扩散系数热等离子体稳定性失控电子传输

Structure–activity relationship and mechanisms of reagents used in scheelite flotation

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Rare Metals 2015年第12期34卷 882-887页

作者： Wan-zhong Yin Ji-zhen Wang zhong-Mei Sun School of Resource and Civil Engineering Northeastern University Design & Research Institute of Zijin

Effects of carboxylic acid collector, benzohydroxamic acid (BHA), sodium hexametaphosphate (SHAP), sodium silicate, and oxalic acid on scheelite flotation were studied through flotation tests, quantum chemical calculation, and flotation solution computational chemistry. In terms of the calculation results, the relationship between chemical reactions occurring on the scheelite surface and molecular structures of the reagents were analyzed. The results show that BHA and carboxylic acid collectors interact with scheelite in different forms and the recovery of scheelite using sodium oleate as collector declines successively from SHAP, sodium silicate, to oxalic acid. Moreover, it is found that the performance of depressant in scheelite flotation is directly related to the group electronegativity, indicating that the latter is a dominant factor that determines the former. These findings will be helpful to the academic research communities of scheelite flotation.

关键词： Scheelite Flotation Flotation reagents Structure–activity relationship

An aero-engine life-cycle maintenance policy optimization algorithm: Reinforcement learning approach

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Chinese Journal of Aeronautics 2019年第9期32卷 2133-2150页

作者： zhen LI Shisheng zhong Lin LIN School of Mechatronics Engineering Harbin Institute of Technology

An aero-engine maintenance policy plays a crucial role in reasonably reducing maintenance cost. An aero-engine is a type of complex equipment with long service-life. In engineering,a hybrid maintenance strategy is adopted to improve the aero-engine operational reliability. Thus,the long service-life and the hybrid maintenance strategy should be considered synchronously in aero-engine maintenance policy optimization. This paper proposes an aero-engine life-cycle maintenance policy optimization algorithm that synchronously considers the long service-life and the hybrid maintenance strategy. The reinforcement learning approach was adopted to illustrate the optimization framework, in which maintenance policy optimization was formulated as a Markov decision process. In the reinforcement learning framework, the Gauss–Seidel value iteration algorithm was adopted to optimize the maintenance policy. Compared with traditional aero-engine maintenance policy optimization methods, the long service-life and the hybrid maintenance strategy could be addressed synchronously by the proposed algorithm. Two numerical experiments and algorithm analyses were performed to illustrate the optimization algorithm in detail.

关键词： Aero-engine Hybrid strategy Maintenance policy Optimization algorithm Reinforcement learning

Experiment of heat transfer in oscillating turbulent flow in a pipe with constant heat flux

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航空动力学报 2013年第9期28卷 1949-1955页

作者： LI Ming-zhen DONG Jin-zhong School of Energy and Power Engineering Beijing University of Aeronautics and Astronautics

Heat transfer characteristics of oscillating turbulent air flow in a pipe heated with constant heat flux were experimentally *** experiments were performed over a range of 245.7 to 902 of the kinetic Reynolds number and 25 to 175 of the dimensionless oscillation *** effects of these two dimensionless parameters were *** results show that the cycle-averaged local Nusselt number increases with both the kinetic Reynolds number and the dimensionless oscillation *** space-cycle averaged Nusselt number also effectively increases with the kinetic Reynolds number and the dimensionless oscillation *** on the experimental data,a correlation equation of the space-cycle averaged Nusselt number for air in terms of these two dimensionless parameters has been obtained.

关键词： oscillating turbulent flow heat transfer kinetic Reynolds number Nusselt number constant heat flux

Plasma Niobium Surface Alloying of Pure Titanium and its Oxidation at 900 ℃

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Chinese Journal of Aeronautics 2007年第2期20卷 111-114页

作者： WANG Wen-bo zhong xu HE Zhi-yong WANG zhen-xia ZHANG Ping-ze Research Institute of Surface Engineering Taiyuan University of Technology Taiyuan 030024 China Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A niobium-modified layer on pure titanium surface was obtained by means of double glow plasma surface alloying technique. The modified layer was uniform, continuous, compact and well adhered to the substrate. The niobium composition in the modified layer decreased gradually from the surface to the substrate. The oxidation behavior of the niobium-modified layer was investigated and com- pared with the untreated surface at 900 ~C for 100 h. Characterization of the layers was performed using X-ray diffraction and scanning electron microscope, respectively. The test results show that the oxidation behavior of pure titanium was improved by niobium alloying process. Niobium has a positive influence on the oxidation resistance.

关键词： niobium pure titanium plasma surface alloying oxidation

Two New Saponins from Lysimachia capillipes Hemsl.

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Journal of Integrative Plant Biology 2005年第10期47卷 1271-1275页

作者： Jing-Kui TIAN zhong-Mei ZOU Li-zhen xu Shi-Lin YANG Department of Chinese Medicine Sciences and Engineering Zhejiang University Hangzhou 310027 China Institute of Medicinal Plants Development Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100094 China

To investigate the saponins from whole plants of Lysimachia capilUpes Hemsl., two new saponins, named capilliposide E （1） and capilliposide F （2）, were isolated. The structures of the new saponins were elucidated as 3β, 22α-dihydroxy-16α-acetat-28→ 13-lactone-oleanane-3-O- [β-D-glucopyranosyl- （1 →2）-α-L-arabinpyranoyl]-22-O-β-D-glucopyranoside （1） and 3β, 22α-dihydroxy- 16α-acetat-28→ 13-lactone-oleanane-3-O-{ [β-D-glucopyranosyl-（1→2）-β-D-glucopyranosyl-（1→4）]-α-L-arabinpyranoyl}-22-O-β- D-glucopyranoside （2）. The structures of these compounds were determined by 1D- and 2D-NMR, MS techniques, and chemical methods.

关键词： capilliposide E and F, Lysimachia capillipes triterpene saponin.

As-cast structure of DC casting 7075 aluminum alloy obtained under dual-frequency electromagnetic field

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 150-154页

作者： Zhi-hao Zhao zhen xu Gao-song Wang Qing-feng Zhu Jian-zhong Cui The Key Laboratory of the Ministry of Education of China for Electromagnetic Processing of Materials Northeastern University

We have experimentally determined the as-cast structures of semi-continuous casting 7075 aluminum alloy obtained in the pres-ence of dual-frequency electromagnetic field. Results suggest that the use of dual-frequency electromagnetic field during the semi-continuous casting process of 7075 aluminum alloy ingots reduces the thickness of the surface segregation layer, increases the height of the melt menis-cus, enhances the surface quality of the ingot, and changes the surface morphology of the melt pool. Moreover, low-frequency electromag-netic field was found to show the most obvious influence on improving the as-cast structure because of its high permeability in conductors.

关键词： electromagnetic fields: semi-continuous casting aluminum alloys as-cast structure

New Cytotoxic Saponins from Lysimachia davurica Ledeb.

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Journal of Integrative Plant Biology 2006年第2期48卷 232-235页

作者： Jing-Kui Tian zhong-Mei Zou Li-zhen xu Shi-Lin Yang Department of Chinese Medicine Sciences and Engineering Zhejiang University Hangzhou 310028 China Institute of Medicinal Plants Development Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100094 China

To investigate the saponins from whole plants of Lysimachia davurica Ledeb., two new saponins named davuricoside I （compound 1） and E （compound 2） were isolated. Their chemical structures were elucidated as 3β, 16α, 28, 29-tetrihydroxy-olean-12-en-3-O-β-D-glucopyranosyl-（1→2）-β-D-glucuronopyranoside （compound 1） and 3β, 16α, 29-trihydroxy-13, 28-epoxy-oleanane-3-O-β-D-glucopyranosyl-（1→2）-β-D-glucuronopyranoside （compound 2） on the basis of their one- and two-dimensional nuclear magnetic resonance and mass spectrometry data, and chemical methods. Compound 1 showed significant cytotoxic activity against human A2780 cells.

关键词： davuricoside I and E Lysimachia davurica triterpene saponin.

Ionic liquid functionalized polymer composite nanotubes toward dye decomposition

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Chinese Chemical Letters 2015年第8期26卷 942-945页

作者： Shu-Qin Cui xu-Yang Ji Fu-Xin Liang zhen-zhong Yang State Key Laboratory of Polymer Physics and Chemistry Institute of Chemistry Chinese Academy of Sciences

Poly（ionic liquid） functionalized composite nanotubes are achieved by ATRP grafting ionic liquid monomers for example ViEtIm^＋Br^- from the poly（DVB-co-VBC） nanotubes surface. PW12O40^3- anion is introduced through anion exchange. The PW12O40^3- based composite nanotubes can synchronously absorb and decompose water soluble dyes for example methyl orange（MO）. The cooperative interplay is promising in highly efficient decomposition of dyes.

关键词： nanotubes toward decompose ionic orange ATRP Ionic absorb dispersed ethanol