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A New Anthranquinone Glycoside from the Seeds of Cassia obtusifolia 被引量:12
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作者 ChuHuaLI XiaoYiWEI +2 位作者 XuELI pingwu BaoJiangGUO 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第12期1448-1450,共3页
A new anthraquinone glycoside, emodin-1-O-β-gentiobioside 1, together with threeknown compounds, chrysophanol-1-O-β-gentiobioside 2, physcion-8-O-β-gentiobioside 3, andchrysophanol-1-O-β-D-glucopyranosyl-(1→3)-β... A new anthraquinone glycoside, emodin-1-O-β-gentiobioside 1, together with threeknown compounds, chrysophanol-1-O-β-gentiobioside 2, physcion-8-O-β-gentiobioside 3, andchrysophanol-1-O-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside4 was isolated from the seeds of Cassia obtusifolia. Its structure was elucidated on the basis ofspectroscopic evidence. 展开更多
关键词 Cassia obtusifolia LEGUMINOSAE anthraqinone glycosides emodin-1-Oβ-gentiobioside.
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Internal Friction and Elastic Study on Surface Nanocrystallized 304 Stainless Steel Induced by High-energy Shot Peening 被引量:4
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作者 pingwu JingyangWANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2002年第2期132-134,共3页
The 304 stainless steel with nanostructured surface layer was successfully obtained by using the high-energy shot peening (HESP) method. The internal friction and Young's modulus of this kind of surface nanocrysta... The 304 stainless steel with nanostructured surface layer was successfully obtained by using the high-energy shot peening (HESP) method. The internal friction and Young's modulus of this kind of surface nanocrystallized material were dynamically measured by means of the vibrating reed apparatus. The results implied that different treatment time could induce different microstructure and distribution characteristic of defects in this kind of materials. It is also demonstrated that there is a transition layer between the nano-layer on surface and the coarse grain region inside. The transition layer obviously has certain influence on the overall mechanical properties. 展开更多
关键词 Surface nanocrystallization Internal friction High-energy shot peening
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Surface-particle-emulsion heat transfer model between fluidized bed and horizontal immersed tube 被引量:1
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作者 pingwu XuFeng 《Journal of University of Science and Technology Beijing》 CSCD 2002年第2期99-103,共5页
A mathematical model, surface-particle-emulsion heat transfer model, ispresented by considering voidage variance in emulsion in the vicinity of an immersed surface. Heattransfer near the surface is treated by disperse... A mathematical model, surface-particle-emulsion heat transfer model, ispresented by considering voidage variance in emulsion in the vicinity of an immersed surface. Heattransfer near the surface is treated by dispersed particles touching the surface and through theemulsion when the distance from the surface is greater than the diameter of a particle. A film withan adjustable thickness which separates particles from the surface is not introduced in this model.The coverage ratio of particles on the surface is calculated by a stochastic model of particlepacking density on a surface. By comparison of theoretical solutions with experimental data fromsome references, the mathematical model shows better qualitative and quantitative prediction forlocal heat transfer coefficients around a horizontal immersed tube in a fluidized bed. 展开更多
关键词 fluidized bed heat transfer two-phase flow mathematical model
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Dynamic process of trace boron non-equilibrium grain boundary segregation and the effect of cooling rate
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作者 pingwu XinlaiHe +1 位作者 BingCao SenChen 《Journal of University of Science and Technology Beijing》 CSCD 2003年第3期30-34,共5页
The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The... The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The results indicate that during cooling process, theamount of segregated boron on grain boundary firstly increases fast, then enters a comparativelyeven increasing stage and increases rapidly again at the third stage. The details of each stagevaried with cooling rate are explained. When the segregation develops to a certain degree, thesegregated boron atoms transform from solute status to precipitate status. 展开更多
关键词 BORON grain boundary non-equilibrium segregation dynamic process
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Temperature distribution and control in liquefied petroleum gas fluidized beds
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作者 LiWang pingwu +2 位作者 YanpingZhang JingYang LigeTong 《Journal of University of Science and Technology Beijing》 CSCD 2004年第3期202-206,共5页
Temperature distribution and control have been investigated in a liquefiedpetroleum gas (LPG) fluidized bed with hollow corundum spheres (A1_2O_3) of 0.867-1.212 mm indiameter at moderately high temperatures (800-1100... Temperature distribution and control have been investigated in a liquefiedpetroleum gas (LPG) fluidized bed with hollow corundum spheres (A1_2O_3) of 0.867-1.212 mm indiameter at moderately high temperatures (800-1100℃). Experiments were carried out for the airconsumption coefficient α in the range of 0.3 to 1.0 and the fluidization number N in the range of1.3 to 3.0. Particle properties, initial bed height, α and N all affect temperature distribution inthe bed. Bed temperature can be adjusted about 200℃ by combined the adjusting of α and N. 展开更多
关键词 liquefied petroleum gas fluidized bed temperature distribution
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Structural and physical properties of permalloy thin films prepared by DC magnetron sputtering at different substrate temperature
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作者 FengpingWang pingwu +4 位作者 HongQiu LiqingPan HuanpingLiu YueTian ShengLuo 《Journal of University of Science and Technology Beijing》 CSCD 2004年第1期30-34,共5页
Permalloy Ni_(80)Fe_(20) films have been grown on thermal oxidized Si (111)wafers by magnetron sputtering at well-controlled substrate temperatures of 300, 500, 640 and 780 Kin 0.65 Pa argon pressure. The base pressur... Permalloy Ni_(80)Fe_(20) films have been grown on thermal oxidized Si (111)wafers by magnetron sputtering at well-controlled substrate temperatures of 300, 500, 640 and 780 Kin 0.65 Pa argon pressure. The base pressure was about 1x10^(-4) Pa. The deposition rate was about 5nm/min for all the films. The structure of the films was studied using X-ray diffraction, scanningelectron microscopy and atomic force microscopy. The composition of the films was analyzed usingscanning Auger microprobe. The resistance and magnetoresistance of the films were measured usingfour-point probe technique. The results show that the content of oxygen in the films decreasesgradually with raising substrate temperature. In addition, the surface morphology of the filmspresents notable change with the increasing of the substrate temperature; the residual gases anddefects decrease and the grains have coalesced evidently, and then the grains have grown upobviously and the texture of (111) orientation develops gradually in the growing film. As a result,the resistivity reduces apparently and magnetoresistance ratio increases markedly with raisingsubstrate temperature. 展开更多
关键词 permalloy film substrate temperature residual gases resistance andmagnetoresistance
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