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Heterogeneous reactions of gaseous methanesulfonic acid with calcium carbonate and kaolinite particles

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science china Chemistry 2010年第12期53卷 2657-2662页

作者： TANG MingJin,LI MengQiu & ZHU Tong State Key Joint Laboratory of environmental Simulation and Pollution Control college of environmental sciences and Engineering,peking university,beijing 100871,china State Key Joint Laboratory of environmental Simulation and Pollution Control college of environmental sciences and Engineering Peking University Beijing China

Heterogeneous reactions of gaseous methanesulfonic acid (MSA) with calcium carbonate (CaCO3) and kaolinite particles at room temperature were investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Methanesulfonate (MS-) was identified as the product in the condensed phase,in accordance with the product of the reaction of gaseous MSA with NaCl and sea salt *** the concentration of gaseous MSA was 1.34 × 10-13 molecules cm-3,the uptake coefficient was (1.21 ± 0.06) × 10-8 (1) for the reaction of gaseous MSA with CaCO3 and (4.10 ± 0.65) × 10 10 (1) for the reaction with *** uptake coefficients were significantly smaller than those of the reactions of gaseous MSA with NaCl and sea salt particles.

关键词： gaseous MSA heterogeneous reaction calcium carbonate kaolinite

PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON POLY (OXYETHYLENE-co-OXYTETRAMETHYLENE) DIOL

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Chinese Journal of Polymer science 2001年第4期19卷 371-376页

作者： Chen-yu Su Guang-li Zhang Hong-zhi Zhang Department of Polymer science and Engineering college of Chemistry and Molecular Engineering peking university beijing 100871, china 北京大学北京

Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of -3 degreesC, while that of polyurethane based upon poly(tetramethylene ether) glycol of the 'same molecular weight, i.e. being 2000, and molecular weight distribution, i.e, in the range of 1.4-1.5, starts to decrease dramatically at 5 degreesC.

关键词： polyurethane poly(oxyethylene-co-oxytetramethylene) diol low temperature resilience heteropolyacid-ethylene oxide initiator system

Heterogeneous reaction of SO_2 on TiO_2 particles

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science china Chemistry 2010年第12期53卷 2637-2643页

作者： SHANG Jing,LI Jia & ZHU Tong State Key Joint Laboratory of environmental Simulation and Pollution Control college of environmental sciences and Engineering,peking university,beijing 100871,china State Key Joint Laboratory of environmental Simulation and Pollution Control college of environmental sciences and Engineering Peking University Beijing China

The heterogeneous reaction of SO2 on TiO2 particles was studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).The influences of the oxygen concentration,relative humidity (RH),and ultraviolet (UV) light illumination (λ=365 nm) intensity on the reaction were *** main product of the heterogeneous reaction of SO2 on TiO2 particles was sulfate with UV illumination and sulfite without *** production of sulfate was promoted significantly with UV illumination or water,and there was a synergistic effect when both were *** the dry system without UV,the heterogeneous reaction of SO2 on TiO2 particles was found to be second-order for SO2 and the initial uptake coefficient,BET,was determined to be 1.94 × *** UV and RH=40%,the reaction order was first-order and the initial uptake coefficient was 1.35 × 10-5.

关键词： SO2 TiO2 DRIFTS heterogeneous oxidation

The reconstruction of fossil planation surface in Chin

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Chinese science Bulletin 2002年第5期47卷 434-440页

作者： FENG Jinliang & GUI ZhijiuDepartment of urban and environmental sciences, peking university, beijing 100871, china Institute of Geography, Hebei Academy of sciences, Shijiazhuang 050011, china Department of urban and environmental sciences Peking University Beijing China Institute of Geography Hebei Academy of Sciences Shijiazhuang China

On the basis of results of relative subjects, the fossil planation surface has been discussed by the authors from the point of geomorphologic view. The discussion contents included the characteristic information, research methods, paleotopography (gradient and altitude) and other problems about fossil planation surface. The recognition and reconstruction of fossil planation surface mainly rely on the following characteristic information: (i) the character of erosion unconformity surface; (ii) the paleo-weathering crust and residual deposits; (iii) the paleo-karst and filled deposit in the paleo-karst under the unconformity surface, and (iv) the character and environment of sediment above the unconformity surface. According to the above-mentioned characteristic information, the authors recognized and reconstructed two stages of fossil planation surface on Pa-leo-land of North china and Yangtze Paleo-land. These two fossil planation surfaces formed from Middle Ordovician to Lower Carboniferous and from

关键词： fossil planation surface characteristic information pa-leotopography reconstruction.

Analysis　of　relationship　between　economic　growth　and　environment　in　Benxi　Shiqiaozi　Development　Zone

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Journal of environmental sciences 1996年第3期8卷 269-274页

作者： Li Bin Ru Jiang Ye Wenhu Xu Yunlin(Center for environmental sciences, peking university, beijing 100871,china) Center for environmental sciences Peking University Beijing 100871 China

How to express and assess the coordination between environmental system and economic system is one crucial problem for the studies on regional sustainable *** present study applies environmental supporting capacity (ESC) to evaluate the comparative coordination of economic development plans in a case study in Shiqiaozi Development *** analysis conclusion showed the method is practicable.A new method for judging the efficiency of utilization of environmental system is also discussed in this paper.

关键词： sustainable development coordination environmental supporting capacity(ESC) Benxi Shiqiaozi Development Zone (BSDZ)

Experimental measurement of growth patterns on fossil corals:Secular variation in ancient Earth-Sun distances

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Chinese science Bulletin 2010年第35期55卷 4010-4017页

作者： ZHANG WeiJia1,3,4,LI ZhengBin2,3 & LEI Yang1 1 Department of Physics,peking university,beijing 100871,china 2 Department of Electrical Engineering and Computer science,peking university,beijing 100871,china 3 State Key Laboratory of Advanced Optical Communication Systems & Networks,peking university,beijing 100871,china 4 Committee of Yuanpei Honors Program,peking university,beijing 100871,china Department of Physics Peking University Beijing China State Key Laboratory of Advanced Optical Communication Systems & Networks Peking University Beijing China Committee of Yuanpei Honors Program Peking University Beijing China Department of Electrical Engineering and Computer science Peking University Beijing China

In recent years,much attention has been given to the increase in the Earth-Sun distance,with the modern rate reported as 5-15 m/cy on the basis of astronomical ***,traditional methods cannot measure the ancient leaving rates,so a myriad of research attempting to provide explanations were met with unmatched *** this paper we consider that the growth patterns on fossils could reflect the ancient Earth-Sun *** mechanical analysis of both the Earth-Sun and Earth-Moon systems,these patterns confirmed an increase in the Earth-Sun *** a large number of well-preserved specimens and new technology available,both the modern and ancient leaving rates could be measured with high precision,and it was found that the Earth has been leaving the Sun over the past 0.53 billion *** Earth's semi-major axis was 146 million kilometers at the beginning of the Phanerozoic Eon,equating to 97.6% of its current *** modern leaving rates are 5-14 m/cy,whereas the ancient rates were much *** results indicate a special expansion with an average expansion coefficient of 0.57H0 and deceleration in the form of Hubble *** the basis of experimental results,the Earth's semi-major axis could be represented by a simple formula that matches fossil measurements.

关键词：地球太阳古代距离生长模式实验石珊瑚量化

Development of tourism resources and environment conservation in china: with special reference to Taishan Mountain

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Journal of environmental sciences 1991年第3期3卷 99-104页

作者： Liu JihanDepartment of Geography,peking university,beijing 100871,china

By analyzing the cases in Taishan Mountain, Shandong Province and other tourist sites in china, this paper pointed out the problems in tourism management, such as resources damage, environment pollution, which are the result of tourism development, and are obstacles to the development. The paper also gave suggestion and practical ways to preserve tourism resources and environment.

关键词： tourism resources environment conservation Taishan Mountain tourism development.

Density-functional formula for strongly correlated systems

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Progress in Natural science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2 and CHEN Nanxian1(1. Department of Physics, Tsinghua university, beijing 100084, china 2. Department of Physics, peking university, beijing 100871, china) Dept. of Phys. Tsinghua Univ. Beijing 100084 China Dept. of Phys. Peking Univ. Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

The regular representation and regular covariant representation of crossed products of Woronowicz C^(*)-algebras

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science china Mathematics 2005年第9期48卷 1245-1259页

作者： ZHANG Xiaoxia~(1,2) & GUO Maozheng~(1,3) 1. School of Mathematical sciences,peking university,beijing 100871,china 2. Department of Mathematics,Yantai university,Yantai 264005,china 3. LMAM,peking university,beijing 100871,china School of Mathematical sciences Peking University Beijing China Department of Mathematics Yantai University Yantai China LMAM Peking University Beijing China

In this paper,it is shown that the regular representation and regular covariant representation of the crossed products A×α G correspond to the twisted multiplicative unitary operators,where A is a Woronowicz C~*-algebra acted upon by a discrete group ***,it is also shown that the regular covariant C~*-algebra is the Woronowicz C~*-algebra which corresponds to a multiplicative ***,an explicit description of the multiplicative unitary operator for C(SU_q(2) )×α (?) is given in terms of those of the Woronowicz C~*-algebra C(SU_q(2) ) and the discrete group G.

关键词： multiplicative unitary operator, Woronowicz C*-algebra, crossed product.