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TRIMETHYLSILYLATED SILICA AS RHEOLOGY MODIFIER FOR SILICONE RESINS

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chinese Journal of Polymer science 2000年第1期18卷 51-55页

作者： Wei Huang Ying Huang Yunzhao Yu center for Molecular science, Institute of Chemistry, chinese academy of sciences, beijing 100080, china 中科院化学所北京

Trimethylsilylated silica was synthesized. through hydrolytic condensation of tetraethoxysilane followed by trimethylsilylation. Rheological properties of the silicone resin with trimethylsilylated silica as modifier were studied. It turned out that the particle size of silica was important to the rheological behavior of the modified resin. Trimethylsilylated silica of medium particle size shows the strongest tendency of forming physical network in the resin.

关键词： silica trimethylsilylation rheology modifier silicone resins

An improved δ-Eddington approximation

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chinese science Bulletin 1999年第4期44卷 304-309页

作者： QIU JinhuanInstitute of Atmospheric physics , chinese academy of sciences , beijing 100029, china Institute of Atmospheric physics Chinese Academy of Sciences Beijing China

Based on an accuracy analysis of two-stream approximations, an improved δ-Eddington ap-proximation is developed. The approximation has much better accuracy than all exiting two-stream ap-proximations as the optical depth is less than unity. As the surface reflectance is zero and the opticaldepth is less than unity, errors in both transmission and reflection calculated by the present approxima-tion are more one time less than those by other two-stream approximations. In the case of aerosol opti-cal depth of2.6%, respectively. The errors are over 41% and one times lessthan those by Eddington or δ-Eddington.

关键词： radiation flux fractional factor of δ-function Eddington approximation.

Effects of gravity waves on the distributions of O_3 and OH in the mesopause region

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chinese science Bulletin 2001年第15期46卷 1265-1268页

作者： XU Jiyao & MA RuipingLaboratory for Space Weather, center for Space science and Applied Research, chinese academy of sciences, beijing 100080, china Laboratory of Numeric Study of Heliospheric physics, chinese academy of sciences, beijing 100080, china Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric physics Chinese Academy of Sciences Beijing China

A dynamical-photochemical model of atmospheric gravity waves is used to study the influences of gravity waves on distributions of atmospheric minor species through transportation and photochemical reactions. We mainly study the effect of gravity waves on the distributions of atmospheric trace gases through the nonlinear photochemical reactions. O3 and OH are taken as examples in this note. The calculations indicate that the effect of gravity waves on the distributions of atmospheric trace gases is mainly through the nonlinear photochemical reactions in the mesopause region. The contribution of the nonlinear photochemical reaction caused by gravity waves can exceed the nonlinear transportation and the eddy diffusion.

关键词： gravity wave photochemical reaction coupling between photochemistry and dynamics.

Ionic effective radii under high-temperatures state

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chinese science Bulletin 1997年第15期42卷 1265-1268页

作者： FU ZhengminInstitute of physics, chinese academy of sciences, beijing 100080, china Institute of physics Chinese Academy of Sciences Beijing China

REFERENCES [1, 2] prove that ionic radii will increase or decrease with temperature rising orlowering. If the ionic radii at room temperature are known, many phenomena of the ioniccompounds occurring at room temperature can be explained. Also if the ionic radii at high tem-perature are known, many phenomena of the ionic compounds occurring at high temperaturecan also be explained. Therefore, to calculate the effective radii of ions at high temperature isconsidered of great significance. For example, the 'investigation of KIO3-CsIO3

关键词： high temperature ionic effective radii ionic compounds.

The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking

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science china Earth sciences 2007年第8期50卷 1266-1272页

作者： YAN BangLiang CMSR, Institute of Atmospheric physics, chinese academy of sciences, beijing 100029, china CMSR Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking is ex-amined by using a mixed-mode model. The results show that the positive feedback process of the ef-fects of the seasonal variation of the upwelling mean on the Kelvin wave is the mechanism of the locking of the event mature phase to the end of the calendar year. The memory of the Rossby waves for the sign-shifting of the sea surface temperature anomaly from positive to negative 6 months before the cold peak time is the other mechanism of the locking of the La Nia event mature phase to the end of the calendar year. The results here are different from previous ones which suggest that the balance between cold and warm trends of sea surface temperature anomaly is the mechanism involved. The cold trend is caused by the upwelling Kelvin wave from upwelling Rossby wave reflected at the western boundary, excited by the westerly anomaly stress over the central Pacific and amplified by the seasonal variation of the coupled strength in its way propagating westward. The warm trend is caused by the Kelvin wave forced by the western wind stress over the middle and eastern equatorial Pacific. The cause of the differences is due to the opposite phase of the seasonal variation of the upwelling mean to that in the observation and an improper parameterization scheme for the effects of the seasonal varia-tion of the upwelling mean on the ENSO cycle in previous studies.

关键词： Kelvin wave Rossby wave interaction between atmosphere and sea positive feedback

Nonlinear interactions between gravity waves and background winds

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Progress in Natural science:Materials International 2007年第6期17卷 639-644页

作者： Liu Xiao1,2 and Xu Jiyao1(1. State Key Laboratory for Space Weather, center for Space science and Applied Research, chinese academy of sciences, beijing 100080, china 2. Graduate University of chinese academy of sciences, beijing 100039, china) State Key Laboratory for Space Weather Chinese Academy of Sciences Beijing 100080 China center for Space science and Applied Research Chinese Academy of Sciences Beijing 100080 China Graduate University Chinese Academy of Sciences Beijing 100039 China

Using the nonlinear propagating gravity waves (GW) model in the two-dimensional compressible atmosphere and the linear GW theory, the process of GW propagation in different background winds, e.g. the direction of the background wind is opposite to (dead wind) or the same as (tail wind) the direction of the horizontal phase velocity of GW, is studied. The results show that the dead wind prolongs the vertical wavelength and accelerates GW propagation. Therefore, GW propagates up to a higher height becomes instable in a short time and eventually induces an inverse jet flow. Then, the vertical wavelength is becoming short due to the nonlinear interactions between GW and the inverse jet flow. The vertical wavelength and group velocity decrease after GW propagates into the tail wind. The initial instable time is delayed. Although most of GW is trapped in the instable region, some of GW propagates above the instable region. Compared with GW propagation in the tail wind, the nonlinear interactions between GW and the dead wind are also strong. In contrast, the linear GW theory predicts that GW can propagate freely in the dead wind. The vertical wavelength simulated by the nonlinear numerical model is different from that predicted by the linear theory greatly after GW propagates into the dead wind.

关键词： gravity waves background winds vertical group velocity vertical wavelength nonlinear interactions.

Difference discrete connection and curvature on cubic lattice

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science china Mathematics 2006年第11期49卷 1458-1476页

作者： WU Ke, ZHAO Weizhong & GUO Hanying Department of Mathematics, Capital Normal University, beijing 100037, china Institute of theoretical physics, chinese academy of sciences, beijing 100080, china Department of Mathematics Capital Normal University Beijing China Institute of theoretical physics Chinese Academy of Sciences Beijing China

In a way similar to the continuous case formally, we define in different but equivalent manners the difference discrete connection and curvature on discrete vector bundle over the regular lattice as base space. We deal with the difference operators as the discrete counterparts of the derivatives based upon the differential calculus on the lattice. One of the definitions can be extended to the case over the random lattice. We also discuss the relation between our approach and the lattice gauge theory and apply to the discrete integrable systems.

关键词： discrete connection, discrete curvature, noncommutative calculus, lattice gauge theory, discrete Lax pair.

An efficient chiral synthesis of (R)-N-[3-acetyl-4-(2-hydroxy-3-isopropylamino-propoxy)phenyl]-butanamide with high enantioselectivity

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science china Chemistry 2009年第8期52卷 1216-1219页

作者： WANG NaiXing1,2 & TANG XinLiang1,3 1 Technical Institute of physics and Chemistry,chinese academy of sciences,beijing 100080,china 2 College of Chemistry and Chemical Engineering,Graduate University of chinese academy of sciences,beijing 100049,china 3 School of Chemical Engineering and Environment,beijing Institute of Technology,beijing 100081,china Technical Institute of physics and Chemistry Chinese Academy of Sciences Beijing China College of Chemistry and Chemical Engineering Graduate University of Chinese Academy of Sciences Beijing China School of Chemical Engineering and Environment Beijing Institute of Technology Beijing China

R-Enantiomer of the β-receptor antagonist N-[3-acetyl-4-(2-hydroxy-3-isopropylamino-propoxy)phenyl] butanamide with high enantioselectivity was synthesized from cheap starting materials and enantiopure chiral reagent through an efficient,convenient and practical synthetic *** product was detected by 1H NMR,13C NMR,and MS,and the enatiomeric excess was determined by chiral HPLC analysis using a chiracel AD-H column.

关键词： chiral synthesis enantioselectivity enatiomeric excess chiral HPLC analysis

Pattern phenomena in an rf discharge dusty plasma system

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science china(physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2, YE Maofu2 & WANG Long2 1. College of science, china Agricultural University, beijing 100083, china 2. Institute of physics, chinese academy of sciences, beijing 100080, china College of science China Agricultural University Beijing China Institute of physics Chinese Academy of Sciences Beijing China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns