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Effect of silicon carbide-based iron catalyst on reactor optimization for non-oxidative direct conversion of methane

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Journal of Energy Chemistry 2023年第6期81卷 519-532,I0012页

作者： Eun-hae Sim Sung Woo Lee jin Ju Lee Seung Ju Han jung Ho Shin Gracia Lee Sungrok Ko Kwan-Young Lee yong Tae Kim C1 Gas&Carbon Convergent Research Center Korea Research Institute of Chemical TechnologyDaejeon 34114Republic of Korea Department of Chemical and Biological Engineering Korea University145 Anam-roSeoul 02841Republic of Korea Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-roSeoul 03722Republic of Korea Chemical Data-Driven Research Center Korea Research Institute of Chemical TechnologyDaejeon 34114Republic of Korea Prospective Tech.Exploring Section Basic Chemical R&D centerLottechemical Corp.Daejeon 34059Republic of Korea Department of Advanced Materials and Chemical Engineering University of Science and Technology(UST)Gajeong-dongYuseongDaejeon 34113Republic of Korea

The conversion of methane to olefins,aromatics,and hydrogen(MTOAH)can be used to stably obtain hydrocarbons when the effect of the catalytic surface is optimized from the reaction engineering *** this study,Fe/Si C catalysts were packed into a quartz tube *** catalytic surfaces of Si C and the impregnated Fe species decreased the apparent activation energies(E_a)of methane consumption in the blank reactor between 965 and 1020℃.Consequently,the hydrocarbon yield increased by 2.4times at 1020℃.Based on the model reactions of ethane,ethylene,and acetylene mixed with hydrogen in the range of 500-1020℃,an excess amount of Fe in the reactor favored the C-C coupling reaction over the selective hydrogenation of acetylene;consequently,coke formation was favored over the hydrogenation *** gas-phase reactions and catalyst properties were optimized to increase hydrocarbon yields while reducing coke *** 0.2Fe catalyst-packed reactor(0.26 wt%Fe)resulted in a hydrocarbon yield of 7.1%and a coke selectivity of<2%when the ratio of the void space of the postcatalyst zone to the catalyst space was adjusted to be≥*** on these findings,the facile approach of decoupling the reaction zone between the catalyst surface and the gas-phase reaction can provide insights into catalytic reactor design,thereby facilitating the scale-up from the laboratory to the commercial scale.

关键词： Non-oxidative methane conversion Ethylene Aromatic Methane pyrolysis Fe/SiC Coke resistance Catalytic reactor

Indeterminate pulmonary nodules in colorectal cancer

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World Journal of Gastroenterology 2015年第10期21卷 2967-2972页

作者： Eun-Joo jung Su-Ran Kim Chun-Geun Ryu jin Hee Paik Jeong Geun Yi Dae-yong Hwang Department of Surgery Colorectal Cancer Center Konkuk University Medical Center Konkuk University School of Medicine Department of Radiology Konkuk University Medical Center Konkuk University School of Medicine

AIM:To investigate the clinicopathologic parameters of pulmonary metastasis in colorectal cancer(CRC) patients after lung operation of indeterminate pulmonary nodules(IPNs).METHODS:From a prospective database of CRCpatients,40 cases that underwent lung operation between November 2008 and December 2012 for suspicious metastatic pulmonary nodules on chest computed tomography(CT)were *** decision to perform a lung operation was made if the patient met the following criteria:(1)completely resected or resectable primary CRC;(2)completely resectable IPNs;(3)controlled or controllable extrapulmonary metastasis;and(4)adequate general condition and pulmonary function to tolerate pulmonary *** operation was performed by a thoracic surgeon without CT-guided biopsy for pathologic ***:A total of 40 cases of lung resection was performed in 29 *** patients underwent repeated lung *** final pathology result showed metastasis from the CRC in 30 cases(75%)and benign pathology in 10 cases(25%).The primary tumor site was the rectum in 26/30(86.6%)cases with pulmonary metastasis,but only 3/10(30%)cases in the benign group had a primary rectal cancer(P=0.001).Positron emission tomography(PET)-CT was performed for 22/30(73.4%)patients in the lung metastasis group and for 6/10(60.0%)patients in the benign ***-CT revealed hot uptake of18fluorine 2-fluoro-2-deoxy-D-glucose with all IPNs in both *** group with pulmonary metastasis had a higher incidence of primary rectal cancer(P=0.001),a more advanced tumor stage(P=0.011),and more frequent lymphatic invasion of tumor cells(P=0.005).Six cases with previous liver metastasectomy were present in the lung metastasis *** carcinoembryonic antigen levels before lung operation were not elevated in any of the ***:The stage and location of the primary tumor and tumor cell infiltration of lymphatics provide useful indicators for deciding on lung resection of IP

关键词： Colorectal neoplasm Lung neoplasm Indeterminate pu

Inverse Curvature Flows of Rotation Hypersurfaces

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Acta Mathematica Sinica,English Series 2021年第11期37卷 1692-1708页

作者： Yu Han jin Xian Feng WANG yong WEI School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071P.R.China School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026P.R.China

We consider the inverse curvature flows of smooth,closed and strictly convex rotation hypersurfaces in space forms M_(κ)^(n+1)with speed function given by F^(-α),whereα∈(0,1]forκ=0,-1,α=1 forκ=1 and F is a smooth,symmetric,strictly increasing and 1-homogeneous function of the principal curvatures of the evolving *** show that the curvature pinching ratio of the evolving hypersurface is controlled by its initial value,and prove the long time existence and convergence of the *** second derivatives conditions are required on F.

关键词： Inverse curvature flow rotation hypersurface

A structure translation model for crystal compounds

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npj Computational Materials 2023年第1期9卷 875-883页

作者： Sungwon Kim Juhwan Noh Taewon jin Jaewan Lee Yousung jung Department of Chemical and Biomolecular Engineering KAIST291 Daehak-roDaejeon 34141South Korea School of Chemical and Biological Engineering Seoul National University1Gwanak-roGwanak-guSeoul 08826South Korea

High-throughput virtual screening for crystals aims to discover new materials by evaluating the property of every virtual candidate in the database *** this process,the major computational bottleneck is the costly structural relaxation of each hypothetical material on the large-scale dataset using density functional theory(DFT)***,we present a generative domain translation framework that maps the unrelaxed structural domains to the relaxed domains,enabling data-driven structural *** model predicts the materials formation energy with a small mean absolute error without DFT relaxations,and furthermore can produce the atomic coordinates consistent with the DFT relaxed *** utility of the proposed concept is not restricted to the structural domains,and we expect that it can be extended to translate the domain of easy-to-compute properties into the domain of more difficult properties.

关键词： translation translate relaxed

Numerical Simulation of Flow in Centrifugal Pump with Complex Impeller

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Journal of Thermal Science 2011年第1期20卷 47-52页

作者： Bao-ling Cui yong-gang Lin Ying-zi jin The Laboratory of Fluid Transmission and Application Zhejiang Sci-Tech University Hangzhou 310018China State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

Based on the Navier-Stokes equations and the Spalart-Allmaras turbulence model,three dimensional turbulent flow fields in centrifugal pump with long-mid-short blade complex impeller are calculated and analyzed *** relative velocity and pressure distributions in the flowpart are *** is found that the flow in the passage of the complex impeller is unsymmetrical due to the joint action between volute and *** back-flow region is at inlet of long-blade suction side,near middle part of long-blade pressure side and outlet of short-blade suction *** flow near volute throat is affected greatly by *** relative velocity is large and it is easy to bring back flow at outlet of the complex impeller near volute *** static and total pressure rise uniformly from inlet to outlet in the *** impeller outlet,the pressure periodically decreases from pressure side to suction side,and then the static pressure sharply rise near the *** experimental results show that the back flow in the impeller has an important influence on the performance of pump.

关键词： Complex impeller Centrifugal pump Numerical simulation Experiment

Phase Transformation and Carbide Precipitation of Functional Gradient Semi-solid 9Cr18 Steel

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Acta Metallurgica Sinica(English Letters) 2018年第8期31卷 823-830页

作者： yong-jin Wang Ren-Bo Song Ren-Feng Song School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Institute of Industrial Science The University of TokyoKomaba 4-6-1MeguroTokyo 153-8505Japan Ansteel Mining Engineering Corporation Anshan 114004China

The unique phase transformation and carbide evolution in 9Cr18 steel were investigated during semi-solid forming and subsequent heat treatment. The functional gradient thixoforging 9Cr18 component was divided into inner area and edge area. Microstructure evolution was different at each area. After semi-solid cooling, the solid particles in the inner area were retained as meta-austenite. During annealing, M_（23）C_6 carbide began to precipitate when temperature reached 700 °*** transformation occurred when temperature reached 800 °C. The occurrence of M_（23）C_6 carbide and martensite structure would be harmful to the mechanical properties of inner area. In the edge area, the liquid underwent eutectic transformation to form bar-shape M_7C_3 carbide and secondary austenite after semi-solid cooling. The width of bar-shape carbide would decrease during annealing. By controlling the carbide evolution, we could tailor the functional gradient material with required property.

关键词： Semi-solid forming Solid/liquid phase Annealing Carbide precipitation

NURBS curve blending using extension

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 570-576页

作者： yong-jin LIU Rong-qi QIU Xiao-hui LIANG Tsinghua National Lab for Information Science and Technology Tsinghua University Beijing 100084 China State Key Lab of Virtual Reality Technology and Systems Beihang University Beijing 100191 China

Curve and surface blending is an important operation in CAD systems, in which a non-uniform rational B-spline （NURBS） has been used as the de facto standard. In local comer blending, two curves intersecting at that comer are first made disjoint, and then the third blending curve is added-in to smoothly join the two curves with G^1- or G^2-continuity. In this paper we present a study to solve the joint problem based on curve extension. The following nice properties of this extension algorithm are exploited in depth：（1） The parameterization of the original shapes does not change; （2） No additional fragments are created. Various examples are presented to demonstrate that our solution is simple and efficient.

关键词： Curve blending Curve fairing Curve extension Non-uniform rational B-spline (NURBS)

Constitutive Modeling for Thixoforming of 9Cr18 Semi-solid Alloy and 3D Forecast Mapping

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Journal of Iron and Steel Research International 2016年第12期23卷 1309-1315页

作者： Ya-ping LI Ren-bo SONG yong-jin WANG School of Materials Science and Engineering University of Science and Technology Beijing

Thixotropic Compression tests were carried out on 9Cr18 semi-solid alloy through Gleeble-1500 thermal simulation machine. According to the experiment analysis, macro separation occurred during thixoforming. The liquid film was extruded outside to the surface and solidified to form eutectic structure. The solid particles were connected with each other and underwent plastic deformation. According to the comparison between Zhou-Guan model and modified Zhou-Guan model, it could be observed that the adding of thixotropic factor played an important role in the regression and the latter one was more credible. The modified Zhou-Guan model could well describe the thixoforming behavior. 3D forecast mapping was built for 9Cr18 semi solid alloy in thixoforming temperature range. It would provide valuable information for selecting process parameters during thixoforming in the manufacture process.

关键词： thixoforming constitutive model liquid fraction thixotropic factor 3D forecast

Inhibitory Effect of the Extract of Phellodendron amurense Ruprecht Root on Collagen-Induced Arthritis in Mice

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Chinese Journal of Integrative Medicine 2017年第10期23卷 755-762页

作者： Hyo Won jung Kyung-Ho Kim yong-Ki Park Department of Herbology College of Korean Medicine Dongguk University Gyeongju (740-814) Republic of Korea Korean Medicine Research and Development Center Dongguk University Gyeongju (740-814) Republic of Korea Department of Acupuncture College of Korean Medicine Dongguk University Gyeongju (740-814) Republic of Korea

Objective： To investigate whether the dried root of Phellodendron amurense Ruprecht（Phellodendri cortex; PC） extract improves arthritic symptoms through anti-inflammatory and immune-modulatory effects in collagen-induced arthritis in mice. Methods： Rheumatoid arthritis（RA） was induced in male DBA/1 mice by immunization with type Ⅱ collagen（ColⅡ）. CIA mice were divided into 5 groups（n=10 per a group） with normal, CIA control, PC extract（50 mg/kg and 100 mg/kg）-treated, and meloxicam（50 mg/kg）-treated as the reference drug. The PC extract or meloxicam were administered orally in CIA mice once a day for 14 days after arthritis induction. Arthritic score, levels of anti-ColⅡ IgG2a antibody, prostaglandin E2（PGE2）, tumor necrosis factor（TNF）-α, and interleukin（IL）-17 in the sera of CIA mice were measured. Histopathological changes in the ankle joints of CIA mice were also analyzed by staining with hematoxylin and eosin（H and E）, safranin-O and immunohistochemistry using anti-TNF-α and anti-IL-17 antibodies. Results： The arthritic score was increased in CIA mice in a time-dependent manner, as were the serum levels of anti-ColⅡ IgG2a antibody, PGE2, TNF-α, and IL-17. However, the oral administration of PC extract at 50 and 100 mg/kg in CIA mice significantly decreased the arthritic scores, and the serum levels of anti-ColⅡ IgG2a, PGE2, TNF-α, and IL-17 compared with those in the CIA group（P〈0.05 or P〈0.01）. Furthermore, histopathological improvement of the joint architecture in CIA mice was observed after administration of PC extract. PC extract also significantly inhibited the expression of TNF-α and IL-17 in the joints of CIA mice by suppressing the expression of their m RNA and proteins. Conclusion： PC extract may improve the pathological progression of RA through the inhibition of joint destruction by synovial inflammation and immune-stimulation, therefore, it would be a potential anti-arthritic agent in RA.

关键词： Phellodendron amurense Phellodendri cortex collagen-induced arthritis anti-arthritic effect