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Crystallization behavior of zeolite beta from acid-leached metakaolin

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Petroleum Science 2010年第4期7卷 541-546页

作者： Li Qiang Zhang Ying Cao Zhijun Gao Wei Cui Lishan Department of Materials Science and Technology China University of Petroleum Beijing 102249 China National key laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Microstructure laboratory for energy Materials China University of Petroleum Beijing 102249 China

Well-crystallized zeolite beta was synthesized by using acid-leached metakaolin as the silica-alumina source and tetraethylammonium hydroxide structure-directing *** influence of the composition of the reaction mixture on product crystallinity was investigated,and the crystallization process was studied by examining solid samples obtained at different synthesis *** showed that the acid-leached metakaolin was fully converted into soluble aluminum and silicon species,which is crucial for the formation of well-crystallized zeolite *** the beginning of the crystallization process,these soluble aluminum and silicon species formed a aluminum-rich intermediate structure with layer *** the crystallization proceeding,more silicon species were incorporated into the zeolite beta framework and the layered structure was changed into spherical particles of zeolite beta with high SiO 2 /Al 2 O 3.ratio and crystallinity.

关键词： Zeolite beta acid-leached metakaolin tetraethylammonium hydroxide (TEAOH) liquid phase transformation mechanism

Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in China

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Journal of Systematics and Evolution 2011年第2期49卷 95-107页

作者： 1,2,3.Sheng-Bin CHEN § 1 Gao-Ming JIANG 3.Zhi-Yun OUYANG 3.Wei-Hua XU 3.Yi XIAO 1 (State {4. laboratory of Vegetation and Environmental Change, Institute of Botany, chinese academy of sciences, Beijing 100093. China) 2 (Graduate University of the chinese academy of sciences, Beijing 10004., China) 3.(State {4. laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental {4., chinese academy of sciences, Beijing 100085, China) (State key laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the chinese academy of sciences Beijing 100049 China) (State key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China) *Correspondence: Gao-Ming JIANG *Correspondence: Sheng-Bin CHEN *Correspondence: ?Author for correspondence. E-mail: jianggm@*** Tel.: 86-10-6283.506 Fax: 86-10-8259614..

Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from China, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

关键词： habitat heterogeneity pteridophytes seed plants species richness water-energy hypothesis.

High-resolution photofragment translational spectro- scopy for the UV photodissociation of C_2H_5I

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Science China Chemistry 2007年第4期50卷 476-482页

作者： BI WeiBin, XU XiLing, HUANG JianGou, XIAO DaoQing & ZHU QiHe Beijing National laboratory for Molecular sciences, State key laboratory of Molecular Reaction Dynamics, Institute of Chemistry, {4., Beijing 100080, China 1. Beijing National laboratory for Molecular sciences State Key Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The photodissociation of ethyl iodide at 279.71, 281.73. 3.4.02 and 3.4.67 nm has been studied on our new mini-photofragment translational spectrometer with a total flight path of only 5 cm. Some vibra-tional peaks are firstly resolved in the TOF spectra of I*(2P1/2) and I(2P3.2) channels. These vibrational peaks are assigned to the excitation states (ν2 = 0, 1, 2,…) of the umbrella mode (ν2, 54. cm-1) of the photofragment C2H5, and the distribution of the vibrational states is obtained. The dissociation {4. has been determined to be D0(C-I)=2.3.4.± 0.03.eV. The {4. partitioning of the available {4. (Eavl=ET+Eint=ET+EV,R) calculated from our experimental data E int /E avl= 22.1% at 281.73.nm, 22.4. at 3.4.02 nm for the I* channel, and E int /E avl= 25.2% at 279.71 nm, 25.9% at 3.4.67 nm for the I channel, seem to be more reliable.

关键词： photofragment translational spectroscopy C_2H_5I photodissociation vibrational state distribution energy partitioning dissociation energy

Diagnostics for the structure of AGNs'broad line regions with reverberation mapping data:confirmation of the two-component broad line region model

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Science China(Physics,Mechanics & Astronomy) 2010年第S1期53卷 196-201页

作者： ZHU Ling1 & ZHANG ShuangNan2 1 Department of Physics and Tsinghua Center for Astrophysics,Tsinghua University,Beijing 100084.China 2 key laboratory of Particle Astrophysics,Institute of High energy Physics,{3.,Beijing 10004.,China 1. Department of Physics and Tsinghua Center for Astrophysics Tsinghua University Beijing 100084 China 2. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

We re-examine the ten Reverberation Mapping(RM) sources with public data based on the two-component model of the Broad Line Region(BLR).In fitting their broad Hβ Mlines,six of them only need one Gaussian component,one of them has a double-peak profile,one has an irregular profile,and only two of them need two components,i.e.,a Very Broad Gaussian Component(VBGC) and an Inter-Mediate Gaussian Component(IMGC).The Gaussian components are assumed to come from two distinct regions in the two-component model;they are the Very Broad Line Region(VBLR) and the Inter-Mediate Line region(IMLR).The two sources with a two-component profile are Mrk 509 and NGC *** time lags of the two components of both sources satisfy tIMLR/tVBLR=V 2VBLR/V 2IMLR,where tIMLR and tVBLR are the lags of the two components while VIMLR and VVBLR represent the mean gas velocities of the two regions,supporting the two-component model of the BLR of Active Galactic Nuclei(AGNs).The fact that most of these ten sources only have the VBGC confirms the assumption that RM mainly measures the radius of the VBLR;consequently,the radius obtained from the R-L relationship mainly represents the radius of ***,NGC 4.51,with a lag of about 5 days in the one component model,is an outlier on the R-L relationship as shown in Kaspi et al.(2005);however this problem disappears in our two-component model with lags of about 2 and 6 days for the VBGC and IMGC,respectively.

关键词： broad line region AGN Reverberation Mapping cross correlation

Influence of synthesis parameters on the crystallinity and Si/Al ratio of NaY zeolite synthesized from kaolin

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Petroleum Science 2010年第3期7卷 403-409页

Well-crystallized high-silica NaY zeolites （Si/Al〉2.5） were prepared from a reaction mixture consisting of metakaolin, sodium silicate solution and seed solution via optimization of the mixture composition and reaction conditions. The transformation from kaolin to high-silica NaY zeolite was confirmed by XRD, SEM and IR techniques. Subsequently, the influence of synthesis parameters, i.e. initial SIO2/Al2O3. initial Na2O/SiO2, initial H2O/SiO2, aging time of the seed solution, crystallization temperature and crystallization time, on the NaY growth was investigated in terms of crystallinity and Si/Al ratio. The results showed that the effects of initial SiO2/Al2O3. initial Na2O/SiO2 and initial H2O/ SiO2 on the crystaIlinity and Si/Al ratio of NaY zeolite are similar to those observed in the conventional syntheses of NaY zeolites only using sodium silicate solution as silicon source. However, due to the use of metakaolin as the main silicon and aluminum sources in the present study, a long crystallization induction period of 20 h was achieved, which can be attributed to the dissolution of metakaolin. In addition, different from the conventional syntheses of zeolite NaY, pure NaY zeolites （i.e. without NaP zeolite impurity） were still obtained even at 120℃ because of the use of a large quantity of seed solution （23.wt%） in the reaction mixture. As the aging time of the seed solution increased from 3.5 h to 22 h, the relative crystallinity of the NaY zeolite first increased sharply and then reached a plateau, while the Si/Al ratio first increased rapidly up to a maximum value of 2.75 corresponding to an aging time of 6.5 h, and then decreased sharply with the aging time.

关键词： Kaolin NaY zeolite high-silica seed solution aging time crystallinity

Light collection of the POLAR detector

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Science China(Physics,Mechanics & Astronomy) 2010年第S1期53卷 43-46页

作者： DONG YongWei,LI YanGuo,WU BoBing,ZHANG YongJie & ZHANG ShuangNan key laboratory of Particle Astrophysics,Institute of High energy Physics,{3.,Beijing 10004.,China 1. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

POLAR is a compact polarimeter dedicated to measuring the polarization of GRBs between 50-3.0 *** light collection of 200 mm×6 mm×6 mm plastic bars has been simulated and optimized in order to get uniform response to X-rays at different points along one single *** to the Monte Carlo results,the amplitude uniformity strongly depends on the level of polishing of the scintillator surface and the covering.A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4.4.bars.

关键词： plastic scintillator light collection gamma-ray burst polarimeter

SVOM gamma ray monitor

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Science China(Physics,Mechanics & Astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,LI YanGuo,ZHANG YongJie & ZHANG ShuangNan key laboratory of Particle Astrophysics,Institute of High energy Physics,{3.,Beijing 10004.,China 1. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich

Cavitation Erosion Behavior of CrMnN Duplex Stainless Steel in Distilled Water and 3. NaCl Solution

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Journal of Materials Science & Technology 2003年第4期19卷 346-350页

作者： Suzhen LUO, Yugui ZHENG, Wei LIU, Heming JING, Zhiming YAO and Wei KEState key laboratory for Corrosion and Protection, Institute of Metai Research, chinese academy of sciences, Shenyang 110016, China Lab. for Corrosion and Protection Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

The cavitation erosion (CE) behavior of CrMnIM ferrite-austenite duplex stainless steel in distilled water and 3. NaCI solution was investigated by using a magnetostrictive-induced CE facility. The damaged surfaces were observed by scanning electron microscope (SEM). It was found that the CE resistance of CrMnN steel was higher than that of OCrl3.i5Mo steel. The mass loss rate of CrMnN steel in distilled water was similar to that in 3. NaCI except at the early stage of CE. The failure mode of ferrite phase was brittle fracture, which had adverse effect on the resistance to CE, while the failure of austenite phase was a ductile failure in CrMnN steel. The excellent resistance to CE was related to the good mechanical properties of austenitic phase and the consumption of CE energy by plastic deformation involving slip and twinning.

关键词： Cavitation erosion CrMnN duplex stainless steel Microstructure Ferrite Austenite Plastic deformation

GRB 0904.3.Marking the death of a massive star at z=8.2

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Science China(Physics,Mechanics & Astronomy) 2010年第S1期53卷 64-68页

作者： LIN Lin1,LIANG EnWei2 & ZHANG ShuangNan3.1 Department of Physics and Center for Astrophysics,Tsinghua University,Beijing 100084.China 2 Department of Physics,Guangxi University,Nanning 53.004.China 3.key {4. of Particle Astrophysics,Institute of High energy Physics,{3.,Beijing 10004.,China Guangxi Univ Dept Phys Nanning 530004 Peoples R China Tsinghua Univ Dept Phys Beijing 100084 Peoples R China Tsinghua Univ Ctr Astrophys Beijing 100084 Peoples R China chinese Acad Sci Inst High Energy Phys Key Lab Particle Astrophys Beijing 100049 Peoples R China

GRB 0904.3.is the new high-z record holder of Gamma-ray bursts(GRBs) with *** present a detailed analysis of both the spectral and temporal features of GRB 0904.3.observed with Swift/BAT and Fermi/*** find that the T90 observed with BAT in the 15-150 keV band is 13.2 s,corresponding to-1.4.s at z=*** once again gives rise to the issue of whether the progenitors of high-z GRBs are massive stars or mergers since the discovery of GRB 080913.at z=*** comparison with the T90 distribution in the burst frame of the current redshift-known GRB sample,we find that it is marginally grouped into the long group(Type II GRBs).The spectrum observed with both BAT and GBM is well fitted by a power-law with exponential cutoff,which yields an Ep=(50.4.7.0) *** event satisfies the Amati-relation well for Type II GRBs within their 3. uncertainty *** results indicate that this event would be produced by the death of a massive *** on the Amati-relation,we derive its distance modulus,which follows the Hubble diagram of the concordance cosmology model at a redshift of-8.2.

关键词： gamma-ray bursts high energy phenomenon cosmology