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Systematic distortion in cosmic microwave background maps

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Science China(Physics,Mechanics & Astronomy) 2009年第5期52卷 804-808页

作者： LIU Hao 1.3 &LI TiPei 1.2 1.ey Laboratory of Particle Astrophysics,institute of High Energy Physics,{1. academy of sciences,beijing 1.0049,China 2center for Astrophysics,Tsinghua University,beijing 1.0084,China 3 Graduate University of chinese academy of sciences,beijing 1.0049,China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China center for Astrophysics Tsinghua University Beijing 100084 China Graduate University of chinese academy of sciences Beijing 100049 China

To minimize instrumentally the induced systematic errors,cosmic microwave background(CMB)anisotropy experiments measure temperature differences across the sky using pairs of horn antennas, temperature map is recovered from temperature difference obtained in sky survey through a map-making *** inspect and calibrate residual systematic errors in the recovered temperature maps is important as most previous studies of cosmology are based on these *** analyzing pixel-ring coupling and latitude dependence of CMB temperatures,we find notable systematic devia- tion from CMB Gaussianity in released Wilkinson Microwave Anisotropy Probe(WMAP)*** detected deviation cannot be explained by the best-fit LCDM cosmological model at a confidence level above 99%and cannot be ignored for a precision cosmology study.

关键词： cosmology cosmic microwave background methods data analysis

Experimental investigation and numerical simulation on the effect of fissure water pressure in vertical sliding surface

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Science China(Technological sciences) 2005年第z1期48卷 53-64页

作者： ZHANG Lei1.2, LI Shihai1. LIAN Zhenzhong1.2 & WANG Yuannian1.1. institute of Mechanics,{1., beijing 1.0080, China 2. Graduate School,{1., beijing 1.0060, China 1. institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. Graduate School Chinese Academy of Sciences 100060 Beijing China

This paper studies the effect of fissure water pressure in different fractures on the critical angle of landslide by laboratory investigation and numerical simulation in order to understand the mechanisms of fissure water pressure on landslide stability. Laboratory observations show that the effect of fissure water pressure on the critical angle of landslide is little when the distance between water-holding fracture and slope toe is three times greater than the depth of fissure water. These experimental results are also simulated by a three-dimensional face-to-face contact discrete element method. This method has included the fissure water pressure and can accurately calculate the critical angle of jointed slope when fissure water pressure in vertical sliding surface exists. Numerical results are in good agreement with experimental observations. It is revealed that the location of water-holding structural surface is important to landslide stability. The ratio of the distance between water-holding fissure and slope toe to the depth of fissure water is a key parameter to justify the effect of fissure water pressure on the critical angle of landslide.

关键词： jointed rock slope, discrete element method, fracture in vertical sliding surface, model experiment,fissure water pressure.

Comparison of degradation reactions of Acid Yellow 61.in both oxidation processes of H_2O_2/UV and O_3

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Journal of Environmental sciences 2001年第3期13卷 304-310页

作者： WANG Yi zhong 1. A.Yedeler 2, A. Kettrup 2(1.Research center for Eco Environmental{1., chinese academy of sciences, beijing 1.0085, China 2 GSF institute of Ecological chemistry, Neuherberg, Postfach 1.29, 85758 Neuherberg, Germany) Research center for Eco-Environmental{1. Chinese Academy of Sciences Beijing 100085 China.

The comparison of degradation of Acid Yellow 61.as a model dye compound in both oxidation processes of H 2O 2/UV and O 3 has been studied. When the decolorization rate of Acid Yellow 61.in both reactions presented similar, it was found there are some differences from the results of AOX removal and production of inorganic ions and organic acids. The results reveal that the H 2O 2/UV has beneficial effect on mineralization than O 3 only for degradation of Acid Yellow 61.solution and it is possible for enhancement of method efficiency by taking longer reaction time and addition of high concentration of oxidants.

关键词： oxidation process H 2O 2/UV O 3 dye compound

MB_8^(2-) (M=Be,Mg,Ca,Sr,and Ba):Planar octacoordinate alkaline earth metal atoms enclosed by boron rings

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Science China chemistry 2010年第8期53卷 1737-1745,1829-1832页

作者： PU ZhiFeng1.GE MaoFa1.& LI QianShu2 1.tate Key Laboratory for Structural chemistry of Unstable and Stable Species {1. National Laboratory for Molecular sciences (BNLMS) institute of chemistry,chinese academy of sciences,{1. 1.01.0,China 2center for Computational Quantum chemistry,South China Normal University,Guangzhou 51.631.China 1. State Key Laboratory for Structural chemistry of Unstable and Stable Species beijing National Laboratory for Molecular{1. (BNLMS) institute of{1. Chinese Academy of Sciences Beijing 100190 China2. Center for Computational Quantum Chemistry South China Normal University Guangzhou 510631 China

Complexes involving planar octacoordinate alkaline earth metal atoms in the centers of eight-membered boron rings have been investigated by two density functional theory (DFT) ***82-with D8h symmetry is predicted to be stable,both geometrically and electronically,since a good match is achieved between the size of the central beryllium atom and the eight-membered boron *** contrast,the other alkaline earth metal atoms cannot be stabilized in the center of a planar eight-membered boron ring because of their large *** following the out-of-plane imaginary vibrational frequency,pyramidal C8v MgB82-,CaB82-,SrB82-,and BaB82-structures are *** presence of delocalized π and σ valence molecular orbitals in D8h BeB82-gives rise to aromaticity,which is reflected by the value of the nucleus-independent chemical *** D8h BeB82-structure is confirmed to be the global minimum on the potential energy surface.

关键词： density functional theory octacoordinate alkaline earth metal aromatic molecular orbital

Interfacial behaviors of PMMA-PEO block copolymers at the air/water interface

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Science China chemistry 2005年第6期48卷 567-573页

作者： CHENG Caixia1. JIAO Tifeng2, TANG Rupei1. LIU Minghua2 & XI Fu1.1. State Key Laboratory of Polymer Physics and chemistry, Joint Laboratory of Polymer Science and Materials,{1., chinese academy of sciences, beijing 1.0080, China 2. CAS Key Laboratory of Colloid and Interface Science,{1., chinese academy of sciences, beijing 1.0080, China 1. State Key Laboratory of Polymer Physics and chemistry Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 2. CAS Key Laboratory of Colloid and Interface Science Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China

Diblock copolymer of PMMA291.b-PEO1.4 and triblock copolymer of PMMA1.0-b- PEO227-b-PMMA1.0 were synthesized and their interfacial properties at the air-water interface were investigated, where both blocks of polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) are surface active but the former is soluble in water while the latter is not. Both the block copolymers could form monolayers with two obvious transition regions. The first transition point is around 1. mN/m, which could be assigned to the pancake-brush change of the PEO chains. The other is around 1. mN/m, which could be ascribed to the condensed packing of PMMA. The surface morphological changes during the compression of the Langmuir monolayers are inves-tigated by using the AFM and SEM methods for the films deposited at different surface pressure or molecular areas. At a lower surface pressure, a typical morphology of PEO-con- taining lipopolymers is observed. Upon compression, sphere-dominant morphologies were observed. While the diblock copolymer is easy to folding, the triblock copolymer is in favor of formation of circular domains through vesiculation.

关键词： PMMA-PEO, block copolymers, monolayer, Langmuir-Blodgett films, AFM.

Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

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Progress in Natural Science:Materials International 2004年第1期14卷 48-55页

作者： SHEN Yaoqing 1.2 , XIANG Jianhai 1.*, WANG Bing 1.2 , LI Fuhua 1.and TONG Wei 3(1. Experimental Marine Biology Laboratory, institute of Oceanology,{1., Qingdao 266071.China 2. Graduate School of the{1., beijing 1.0039, China 3. Genomics & Bioinformatics institute,{1., beijing 1.1.00, China) chinese Acad Sci Inst Oceanol Expt Marine Biol Lab Qingdao 266071 Peoples R China chinese Acad Sci Grad Sch Beijing 100039 Peoples R China chinese Acad Sci Geonom & Bioinformat Inst Beijing 101300 Peoples R China

A total of 1.446 expressed sequence tags (ESTs) are obtained by a large scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis . An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

关键词： Fenneropenaeus chinensis bioinformatics ESTs immune factors

Photogeneration of the free radicals and singlet oxygen by chrysophanol from rheum

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Science China chemistry 2004年第5期47卷 381-387页

作者： RAO Jing1.2, XIE Jie1. ZHAO Jingquan1.& ZHU Teng2 1. Key Laboratory of Photochemistry,{1. for Molecular Science, institute of chemistry, The chinese academy of sciences, beijing 1.0080, China 2. University of Science and Technology beijing, beijing 1.083, China 1. Key Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences 100080 Beijing China 2. University of Science and Technology beijing 10083 Beijing China

In the current work, chryosphanol (MHAQ) was isolated and purified from rheum, and the photosensitization activities were studied. In nitrogen-saturated DMSO solution, irradia- tion of chryosphanol (MHAQ) with visible light (>430 nm) produced the semiquinone radical anions (MHAQ??), which was intensified significantly by an electron donor NADH, suggesting electron transfer between the excited and ground state photosensitizer molecules. In an air-saturated DMSO solution, superoxide radical anions (O2 ), trapped by DMPO, were detected. ?? It was proved that O2 was not originated from the singlet oxygen (1.2) but dependent on DMPO, ?? chrysophanol, oxygen and the irradiation time. The singlet oxygen and OH could also be pro- ? duced by the photosensitization of the photosensitizer. These suggest that chrysophanol pos- sesses the photosensitization activity via Type I mechanism and Type II mechanism. To evaluate the photosensitization activities of MHAQ, emodin and mixed anthraquinone derivatives ex- tracted from rheum, the relative productivities of O2 were estimated to be 1.8, 1.1.and 1.0 re- ?? spectively and the quantum yields for singlet oxygen to be 0.36, 0.53 and 0.1. respectively. Therefore, these low-cost pigments may be potentially used as phototherapeutic medicine for some kind of vascular diseases or photo-activated pesticides.

关键词： chrysophanol, ESR, semiquinone radical anions, superoxide radical anions, hydroxyl radical, singlet oxygen.

Effect of concentration on surfactant micelle shapes——A molecular dynamics study

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Science China chemistry 2005年第5期48卷 470-475页

作者： GAO Jian1.2, GE Wei1.& LI Jinghai1.1. Multiphase Reaction Laboratory, institute of Process Engineering,{1., beijing 1.0080, China 2. Graduate School of The{1., beijing 1.0085, China 1. Multiphase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of The chinese academy of sciences 100085 Beijing China

Many aspects of the behavior of surfactants have not been well understood due to the coupling of many different mechanisms. Computer simulation is, therefore, attractive in the sense that it can explore the effect of different mechanisms separately. In this paper, the shapes, structures and sizes of sodium dodecylbenzenesulfonate (SDBS) micelles under different con-centrations in an oil/water mixture were studied via molecular dynamics (MD) simulations using a simplified atomistic model which basically maintains the hydrophile and lipophile properties of the surfactant molecules. Above the critical micellar concentration (cmc), surfactant molecules ag-gregate spontaneously to form a wide variety of assemblies, from spherical to rodlike, wormlike and bilayer micelles. Changes in their ratios of the principle moments of inertia (g1.g3, g2/g3) in-dicated the transition of micelle shapes at different concentrations. The aggregation number of micelle is found to have a power-law dependence on surfactant concentration.

关键词： surfactant, MD simulation, sodium dodecylbenzenesulfonate, micelle shape.

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,{1., beijing 1.0080, China 2. Graduate University of{1., beijing 1.0039, China) [a]State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China [b]Graduate University of chinese academy of sciences Beijing 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.