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| 1 | Design of a new dynamical core for global atmospheric models based on some efficient numerical methods显示文摘A careful study on the integral properties of the primitive hydrostatic balance equations for baroclinic atmosphere is carried out, and a new scheme todesign the global adiabatic model of atmospheric dynamics ispresented. This scheme includes a method of weighted equal-areamesh and a fully discrete finite difference method with quadraticand linear conservations for solving the primitive equationsystem. Using this scheme, we established a new dynamical corewith adjustable high resolution acceptable to the availablecomputer capability, which can be very stable without anyfiltering and smoothing. Especially, some important integralproperties are kept unchanged, such as the anti-symmetries of thehorizontal advection operators and the vertical convectionoperator, the mass conservation, the effective energy conservationunder the standard stratification approximation, and so on. Somenumerical tests on the new dynamical core, respectively regardingits global conservations and its integrated performances inclimatic modeling, incorporated with the physical packagesfrom the Community Atmospheric Model Version 2 (CAM2) of NationalCenter for Atmospheric Research (NCAR), are included. | WANG Bin, WAN Hui, Jl Zhongzhen, ZHANG Xin, YU Rucong, YU Yongqiang & LIU HongtaoState Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Department of Computational Mathematics, Academy of Mathematics and System Sciences, Peking University, Beijing 100871, China | 2004 | Science China Mathematics2004，47，z1： | 92 |
| 2 | Biomass carbon stocks in China's forests between 2000 and 2050:A prediction based on forest biomass-age relationships显示文摘China's forests are characterized by young forest age,low carbon density and a large area of planted forests,and thus have high potential to act as carbon sinks in the future.Using China's national forest inventory data during 1994-1998 and 1999-2003,and direct field measurements,we investigated the relationships between forest biomass density and forest age for 36 major forest types.Statistical approaches and the predicted future forest area from the national forestry development plan were applied to estimate the potential of forest biomass carbon storage in China during 2000-2050.Under an assumption of continuous natural forest growth,China's existing forest biomass carbon(C) stock would increase from 5.86 Pg C(1 Pg=1015 g) in 1999-2003 to 10.23 Pg C in 2050,resulting in a total increase of 4.37 Pg C.Newly planted forests through afforestation and reforestation will sequestrate an additional 2.86 Pg C in biomass.Overall,China's forests will potentially act as a carbon sink for 7.23 Pg C during the period 2000-2050,with an average carbon sink of 0.14 Pg C yr-1.This suggests that China's forests will be a significant carbon sink in the next 50 years. | XU Bing,GUO ZhaoDi,PIAO ShiLong & FANG JingYun* Department of Ecology,College of Urban and Environmental Sciences,and Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China | 2010 | Science China(Life Sciences)2010，53，7： | 61 |
| 3 | Patterns of above-and belowground biomass allocation in China's grasslands:Evidence from individual-level observations显示文摘Above-and belowground biomass allocation not only influences growth of individual plants,but also influences vegetation structures and functions,and consequently impacts soil carbon input as well as terrestrial ecosystem carbon cycling.However,due to sampling difficulties,a considerable amount of uncertainty remains about the root:shoot ratio(R/S),a key parameter for models of terrestrial ecosystem carbon cycling.We investigated biomass allocation patterns across a broad spatial scale.We collected data on individual plant biomass and systematically sampled along a transect across the temperate grasslands in Inner Mongolia as well as in the alpine grasslands on the Tibetan Plateau.Our results indicated that the median of R/S for herbaceous species was 0.78 in China's grasslands as a whole.R/S was significantly higher in temperate grasslands than in alpine grasslands(0.84 vs.0.65).The slope of the allometric relationship between above-and belowground biomass was steeper for temperate grasslands than for alpine.Our results did not support the hypothesis that aboveground biomass scales isometrically with belowground biomass.The R/S in China's grasslands was not significantly correlated with mean annual temperature(MAT) or mean annual precipitation(MAP).Moreover,comparisons of our results with previous findings indicated a large difference between R/S data from individual plants and communities.This might be mainly caused by the underestimation of R/S at the individual level as a result of an inevitable loss of fine roots and the overestimation of R/S in community-level surveys due to grazing and difficulties in identifying dead roots.Our findings suggest that root biomass in grasslands tended to have been overestimated in previous reports of R/S. | WANG Liang*,NIU KeChang,YANG YuanHe & ZHOU Peng Department of Ecology,Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China. | 2010 | Science China(Life Sciences)2010，53，7： | 54 |
| 4 | Mobius Isoparametric Hypersurfaces in S^(n+1) with Two Distinct Principal Curvatures | Hai Zhong LI Department of Mathematics, Tsinghua University. Beijing 100084. P. R. China Hui Li LIU Department of Mathematics, Northeastern University. Shenyang 110000. P. R. China Chang Ping WANG Key Laboratory of Pure and Applied Mathematics, School of Mathematical Sciences. Peking University, Beijing 100871, P. R. China Guo Song ZHAO Department of Mathematics, Sichuan University, Chengdu 610064. P. R. China | 2002 | Acta Mathematica Sinica,English Series2002，18，3： | 53 |
| 5 | Kinematics and dynamics of the Mesozoic orogeny and late-orogenic extensional collapse in the Sino-Mongolian border areas显示文摘The Sino-Mongolian border areas underwent two important tectonic events during Mesozoic time after late Paleozoic orogeny: a late Triassic to earlier Jurassic contractional event that resulted in a large-scale south-vergent thrust during the orogeny and a late Jurassic-earlier Cretaceous extensional event in a north-south direction that formed a metamorphic core complex. The kinematic and dynamic analyses show that the thrust sheet moved southwards with a kinematic vorticity number of ca. -0.10 and sub-horizontal maximum compressive stress axis that belongs to a contraction-thickening shear. The upper plate of the late-orogenic detachment relatively moved in a 165°direction. The average kinematic vorticity in its earlier stage was 0.74 that belongs to simple shear dominated shearing and related to the maximum compressive stress axes dipping at ~66°, while the later average kinematic vorticity was ~0.55°that belongs to pure shear dominated shearing with sub-vertical maximum compressive stress axes. This suggests that the thrusting led to the crust thickened and the lower plate rocks that were originally located in the upper crust depressed through a brittle-ductile transition zone into the lower crust and became warmer. The heated rocks trended to uplift since their increasing volume and decreasing density while the loading of the upper-plate rocks increased due to the structural thickening. Under the combined effect of the loading and the thermal-uplifting, the ductile shear zone in between increased in its component of vertical pure shear. Once its pure-shear component exceeded its simple-shear one the ductile shear zone became an extension-thinned shear zone. This progressive transitional process reflects internal and essential temporal and spatial relationships: the extensional factor nucleated during the crust thickening by thrusting and increase of the extensional factor finally led to late-orogenic collapse. | ZHENG Yadong 1 & WANG Tao2 1. Key Laboratory of Orogenic Belts and Crustal Evolution (Peking University), Ministry of Education, Beijing 100871, China 2. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China | 2005 | Science China Earth Sciences2005，48，7： | 38 |
| 6 | Ultrahigh pressure (>7 GPa) gneissic K-feldspar (-bearing) garnet clinopyroxenite in the Altyn Tagh, NW China: Evi- dence from clinopyroxene exsolution in garnet显示文摘The exsolution of clinopyroxene and rutile in coarse-grain garnet is found in the gneissic K-feldspar(-bearing) garnet clinopyroxenite from Yinggelisayi in the Altyn Tagh, NW China. The maximum content of the exsolved clinopyroxene in the garnet is up to >5% by volume. The reconstructed precursor garnet (Grt1) before exsolution has a maximum Si content of 3.061 per formula uint, being of supersilicic or majoritic garnet. The peak-stage metamorphic pressure of >7 GPa is estimated using the geobarometer for volume percentage of exsolved pyroxene in garnet and the Si-(Al+Cr) geobarometer for majoritic garnet, and the temperature of about 1000℃ using the ternary alkali-feldspar geothermometer and the experimental data of ilmen- ite-magnetite solid solution. The protoliths of the rocks are intra-plate basic and intermediate ig- neous rocks, of which the geochemical features indicate that they are probably the products of the evolution of basic magma deriving from the continental lithosphere mantle. The rocks are in outcrops associated with ultrahigh pressure garnet-bearing lherzolite and ultrahigh pressure garnet granitoid gneiss. All of these data suggest that the ultrahigh pressure metamorphic rocks in the Altyn Tagh are the products of deep-subduction of the continental crust, and such deep- subduction probably reaches to >200 km in depth. This may provide new evidence for further discussion of the dynamic mechanism of the formation and evolvement of the Altyn Tagh and the other collision orogenic belts in western China. | LIU Liang1,3, CHEN Danling1, ZHANG Anda1, SUN Yong1, WANG Yan1, YANG Jiaxi1,2 & LUO Jinhai1 1. Key Laboratory of Continental Dynamics of the Ministry of Education of China, Northwest University, Xi’an 710069, China 2. College of Earth Science and Land Resources, Chang’an University, Xi’an 710054, China 3. The Laboratory of Orogen and Basin of the Ministry of Education, Peking University, Beijing 100871, China | 2005 | Science China Earth Sciences2005，48，7： | 38 |
| 7 | Optimization of the head shape of the CRH3 high speed train显示文摘Aiming at optimizing the head shape of the CRH3 high speed train, an efficient optimization approach is proposed. The CFD analysis by solving Navier-Stokes equations is coupled with optimization calculation based on the multi-objective genetic algorithm, meanwhile the arbitrary shape deformation technique (ASD) is also introduced into the design flow, which greatly shortens the time consumption for geometry regeneration and flow field remeshing. As a result, the efficiency of the optimization calculation is highly improved. Statistical analysis is done to the designs in the design space, and the correlation between the design variables and the objective is studied to find out the key variables that most affect the objective. Response surface analysis is also performed to get the nonlinear relationship between the key design variables and the objective with the Kriging algorithm. Finally, after the optimization, an aerodynamic performance comparison between the optimal shape and the original shape reveals that the original shape of CRH3 high speed train owns a very stable aerodynamic performance and can be trustingly used in industry. | SUN ZhenXu1, SONG JingJing1 & AN YiRan1 College of Engineering, State Key Laboratory for Turbulence and Complex Systems, Peking University, Beijing 100871, China | 2010 | Science China(Technological Sciences)2010，53，12： | 35 |
| 8 | The^(40)Ar/^(39)Ar age record of formation and uplift of the blueschists and eclogites in the western Tianshan Mountains显示文摘The 40Ar/39Ar ages indicate that the eclogite facies rocks of the Hasiate slice in the western Tianshan Mountains were formed at the early stage of Devonian (401 Ma) and had been uplifted to the greenschist facies tectonic level in the middle stage of Devonian (381 Ma). The formation and uplift of the blueschists of the Akesayi slice are constrained to the late stage of Devonian (370-364 Ma). The different tectonic slices in the high-pressure metamorphic belt have experienced the different uplift history. | GAO Jun, ZHANG Lifei & LIU Shengwei1. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 2. Department of Geology, Peking University, Beijing 100871, Chin | 2000 | Chinese Science Bulletin2000，45，11： | 35 |
| 9 | Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process显示文摘The structural pattern of the eastern Himalayan syntaxis in Namjagbarwa consists of two series of structures with different styles. One series compiles the earlier ductile contractional and lateral-slip deformation system, formed by nearly north-south shortening within the syntaxis, left-lateral and right-lateral slipping along its western and eastern boundaries respectively. They were possibly produced by the indentation of the Indian continent into Asian continent after India-Asia collision. The peak deformation-metamorphic ages in these structures are 62-60 Ma, ~23 Ma and ~13 Ma. The other series is composed of ductile-brittle normal faults distributing concentrically and dipping toward the outsides of Namjagbarwa Peak. They were probably the collapse structures caused by rapid uplift in a later time and the beginning ages for the normal faulting are about 7.3-6.3 Ma. | ZHANG Jinjiang, Jl Jianqing, ZHONG Dalai, DING Lin & HE Shundong1. Department of Geology, Peking University, Beijing 100871, China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China Correspondence should be addressed to Zhang Jinjiang (email: zhjj@pku.edu.cn) | 2004 | Science China Earth Sciences2004，47，2： | 34 |
| 10 | An Archean continental block in the Taihangshan and Hengshan regions: Constraints from geochronology and geochemistry显示文摘Recent research on the tectonothermal evolution and geochronology in the Fuping, Hengshan and Wutaishan metamorphic complexes, together with the discoveries of a high-pressure granulite belt in the northern margin of the North China Craton (NCC) and high-pressure metapelites in the Jingangku Group of the Wutaishan complex, suggests that there was a Neoarchean to Paleoproterozoic orogenic belt related to collision between the Eastern and Western continental blocks. Comparison of geological, geochronological, tectonothermal and geochemical data between the Fuping and Hengshan complexes suggests these two complexes most likely originated and evolved as a single lithotectonic domain (i.e., the Taihangshan-Hengshan block) during the early evolution of the North China Craton, probably as an active margin to the Eastern Continental Block. The Taihangshan-Hengshan block has been subjected to intensive and extensive tectono-magmatism and high-grade metamorphism related to collision between the Eastern and Western continental blocks at ~1.80 Ga. | LIU Shuwen , LI Jianghai, PAN Yuanming, ZHANG Jian and LI Qiugen(1. The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China 2. Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada) | 2002 | Progress in Natural Science:Materials International2002，12，8： | 32 |
| 11 | Technical framework for Internetware: An architecture centric approach显示文摘Being a new software paradigm evolved by the Internet, Internetware brings many challenges to the traditional software methods and techniques. Sponsored by the national basic research program (973), researchers in China have developed an architecture centric technical framework for the definition, incarnation and engineering of Internetware. First of all, a software model for Internetware is defined for what to be, including that Internetware entities should be packaged as components, behaving as agents, interoperating as services, collaborating in a structured and on demand manner, etc. Secondly, a middleware for Internetware is designed and implemented for how to be, including that Internetware entities are incarnated by runtime containers, structured collaborations are enabled by runtime software architecture, Internetware can be managed in a reflective and autonomic manner, etc. Thirdly, an engineering methodology for Internetware is proposed for how to do, including the way to develop Internetware entities and their collaborations by transforming and refining a set of software architectures which cover all the phases of software lifecycle, the way to identify and organize the disordered software assets by domain modeling, etc. | YANG FuQing1,2, Lü Jian3,4 & MEI Hong1,2 1 Key Laboratory of High Confidence Software Technologies (Peking University), Ministry of Education, Beijing 100871, China 2 School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China 3 State Key Laboratory for Novel Software Technology, Nanjing 210093, China 4 Department of Computer Science and Technology, Nanjing University, Nanjing 210093, China | 2008 | Science in China(Series F)2008，51，6： | 33 |
| 12 | Above-and belowground biomass in relation to envi- ronmental factors in temperate grasslands, Inner Mongolia显示文摘Above- and belowground biomasses of grasslands are important parameters for characterizing re- gional and global carbon cycles in grassland ecosystems. Compared with the relatively detailed in- formation for aboveground biomass (AGB), belowground biomass (BGB) is poorly reported at the re- gional scales. The present study, based on a total of 113 sampling sites in temperate grassland of the Inner Mongolia, investigated regional distribution patterns of AGB, BGB, vertical distribution of roots, and their relationships with environmental factors. AGB and BGB increased from the southwest to the northeast of the study region. The largest biomass occurred in meadow steppe, with mean AGB and BGB of 196.7 and 1385.2 g/m2, respectively; while the lowest biomass occurred in desert steppe, with an AGB of 56.6 g/m2 and a BGB of 301.0 g/m2. In addition, about 47% of root biomass was distributed in the top 10 cm soil. Further statistical analysis indicated that precipitation was the primary determinant factor in shaping these distribution patterns. Vertical distribution of roots was significantly affected by precipitation, while the effects of soil texture and grassland types were weak. | MA WenHong1,2, YANG YuanHe1, HE JinSheng1, ZENG Hui1,2 & FANG JingYun1 1 Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China 2 School of Environment & Urban Study, Peking University Shenzhen Graduate School, Shenzhen 518055, China | 2008 | Science China(Life Sciences)2008，51，3： | 34 |
| 13 | Micro-mechanical analysis of dynamic processes of nanomanipulation显示文摘In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture. | HU Jie, ZHANG Yujun, LI Peng, WANG Hui, HUANG Lan & HU YuanzhongState Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China Department of Physics, Tsinghua University, Beijing 100084, China College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China | 2004 | Science China(Physics,Mechanics & Astronomy)2004，47，z1： | 28 |
| 14 | Study of spatial distribution of sandy desertification in North China in recent 10 years显示文摘Sandy desertification is a land degradation characterized by wind erosion, mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in North China. It is one of main kinds of desertification/land degradation as well as water-soil erosion and salinization in China. Rapid and continuous spread of sandy desertification during last 50 years has created a major environmental and socio-economic problem in North China. Remote sensing monitored results in 2000 showed that the sandy desertified land area has been 38.57×104 km2. The area of potential to slightly sandy desertified land is 13.93×104 km2, moderately land 9.977×104 km2, severely land 7.909×104 km2 and very severely land 6.756×104km2. Sandy desertification mainly occurs in the semi-arid mixed farming-grazing zone and its northern rangeland zone, semi-arid dryland rainfed cropping zone and arid oasis-desert margin zone. The average annually developmental rate of sandy desertified land increased from 2,100tion in North China is 'overall deterioration, while local rehabilitation'. Already achieved rehabilitation results and monitoring assessment show that about 60% of desertified land in North China can be restored under the conditions of rational land-use ways and intensity. | WANG Tao, WU Wei, XUE Xian, SUN Qingwei & CHEN GuangtingKey Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Department of Environment Engineering, Peking University, Beijing 100871, China | 2004 | Science China Earth Sciences2004，47，z1： | 28 |
| 15 | Nature of the Precambrian metamorphic blocks in the eastern segment of Central Tianshan:Constraint from geochronology and Nd isotopic geochemistry显示文摘Granitoid gneisses are widespread in Precambrian metamorphic blocks of eastern segment of the Central Tianshan Tectonic Zone, and they have intrusive contact relationships with their metamorphic sedimentary country rocks of Proterozoic Xingxingxia and Kawabulag groups. Zircon U-Pb ages from a granodioritic gneiss (IW11-1) and a parametamorphic schist (W05-9) are determined at the Weiya area. Euhedral prismatic zircons from the granodioritic gneiss (IW11-1) provide U-Pb isotopic discordia intercept ages of 1218±17 Ma and 426±26 Ma, respectively, and euhedral prismatic zircons from the parametamorphic schist (W05-9) display U-Pb isotopic discordia intercept ages of 1216±74 Ma and 290±15 Ma, respectively. A whole-rock Sm-Nd isotopic isochron is determined in augen granitoid gneiss samples at the Gang- gou-Kumishi area and we obtain the isochron age of 1142±120 Ma, and its ε Nd (t) = -4.3. These geochronological data suggest that these Precambrian metamorphic basement blocks within eastern segment of the Central Tianshan Tectonic Zone can be produced during 1140—1220 Ma, and occur a nearly homochronous metamorphism. Integrated to these geochronological data, Nd depleted mantle model ages (T DM ) and epsilon Nd(t) values of these granitoid gneiss samples indicate that they can derive from mixing in various scales both magmas from mantle and crust sources at a late Mesoproterozoic active continental margin tectonic environment. Similarity in geochronology, Sm-Nd isotopic geochemistry between Weiya-Xingxingxia, Pargangtag and Ganggou-Kumishi areas suggests that they could be a bigger uniform metamorphic basement block, which could be formed by the assembly of the supercontinent Rodinia and be separated by late geological processes. | LIU Shuwen,GUO Zhaojie,ZHANG Zhicheng,LI Qiugen & ZHENG Haifei The Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,China School of Earth and Space Sciences,Peking University,Beijing 100871,China | 2004 | Science China Earth Sciences2004，47，12： | 26 |
| 16 | The roles of heterogeneous chemical processes in the formation of an air pollution complex and gray haze显示文摘Urban and regional air pollutions are characterized by high concentrations of secondary pollutants such as photo-oxidants (mainly ozone) and fine particulate matter,which are formed through chemical reactions of the primary pollutants emitted from various sources.The accumulation of these pollutants under stagnant meteorological conditions results in the formation of gray haze,reducing visibility and causing major impacts on human health and climate.In an air pollution complex,the coexistence of high concentrations of primary and secondary gaseous and particulate pollutants provides a large amount of reactants for heterogeneous reactions on the surface of fine particles;these reactions change the oxidizing capacity of the atmosphere,as well as chemical compositions along with the physicochemical and optical properties of particulate matter,thereby accelerating formation of the air pollution complex and gray haze.Using in situ technologies,such as diffuse reflectance infrared Fourier-transform spectroscopy and single-particle Raman spectroscopy,we systematically investigated the reaction kinetics and mechanisms of gaseous pollutants (i.e.,NO2,SO2,O3,and formaldehyde) on the surfaces of the major components of atmospheric particles such as CaCO3,kaolinite,montmorillonite,NaCl,sea salt,Al2O3,and TiO2.We found that the main reaction products were sulfate,nitrate,or formate,which can change the hygroscopicity and light extinction parameters of those particles significantly.By analyzing the reaction kinetics of these heterogeneous reactions,we identified synergetic mechanisms of the three ternary reaction systems,i.e.,NO2-particlesH2O,SO2-particles-O3,and organics/SO2-particles–UV illumination.These synergetic mechanisms can provide experimental and theoretical bases for understanding the feedback mechanisms and nonlinear processes in the formation of an air pollution complex and gray haze. | ZHU Tong,SHANG Jing & ZHAO DeFeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China | 2011 | Science China Chemistry2011，54，1： | 24 |
| 17 | Quantitative relationships between vegetation and several pollen taxa in surface soil from North China显示文摘According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept | LI Yiyin, ZHANG Xinshi & ZHOU Guangsheng1. Department of Urbon and Environmental Sciences, Peking University, Beijing 100871, China 2. Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 3. School of Urban and Environmental Sciences, Northeast Normal University, Changchun 130024, China Correspondence should be addressed to Li Yiyin | 2000 | Chinese Science Bulletin2000，45，16： | 24 |
| 18 | Heterogeneous reactions on the surface of fine particles in the atmosphere显示文摘Fine particles play an important role in the atmosphere. Research on heterogeneous reactions on the surface of fine particles is one of the frontier areas of atmospheric science. In this paper, physical and chemical characteristics of fine particles in the atmosphere and the interactions between trace gases and fine particles are described, methods used in heterogeneous reactions research are discussed in detail, progress in the study of heterogeneous reactions on the surface of fine particles in the atmosphere is summarized, existing important questions are pointed out and future research directions are suggested. | DING Jie & ZHU Tong State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, China Correspondence should be addressed to Zhu Tong (e-mail:tzhu@ pku.edu.cn) | 2003 | Chinese Science Bulletin2003，48，21： | 24 |
| 19 | Some basic concepts and problems on the petrogenesis of intra-plate ocean island basalts显示文摘Basaltic magmatism that builds intra-plate ocean islands is often considered to be genetically associated with 'hotspots' or 'mantle plumes'. While there have been many discussions on why ocean island basalts (OIB) are geochemically highly enriched as an integral part of the mantle plume hypothesis, our current understanding on the origin of OIB source material remains unsatisfactory, and some prevailing ideas need revision. One of the most popular views states that OIB source material is recycled oceanic crust (ROC). Among many problems with the ROC model, the ocean crust is simply too depleted (e.g., [La/Sm]PM <1) to be source material for highly enriched (e.g., [La/Sm]PM >> 1) OIB. Another popular view states that the enriched component of OIB comes from recycled continental crust (RCC, i.e.; terrigenous sediments). While both CC and OIB are enriched in many incompatible elements (e.g., both have [La/Sm]PM >>1), the CC has characteristic enrichment in Pb and deletion in Nb, Ta, P and Ti. Such signature is too strong to be eliminated such that CC is unsuitable as source material for OIB. Plate tectonics and mantle circulation permit the presence of ROC and RCC materials in mantle source regions of basalts, but they must be volumetrically insignificant in contributing to basalt magmatism. The observation that OIB are not only enriched in incompatible elements, but also enriched in the progressively more incompatible elements indicates that the enriched component of OIB is of magmatic origin and most likely associated with low-degree melt metasomatism. H2O and CO2 rich incipient melt may form in the seismic low velocity zone (LVZ). This melt will rise because of buoyancy and concentrate into a melt rich layer atop the LVZ to metasomatize the growing lithosphere, forming the metasomatic vein lithologies. Erupted OIB melts may have three components: (1) fertile OIB source material from depth that is dominant, (2) the melt layer, and (3) assimilation of the metasomatic vein lithologies formed earlier in the growing/grown lithosphere. It is probable that the fertile source material from depth may be (or contain) recycled ancient metasomatized deep portions of oceanic lithosphere. In any attempt to explain the origin of mantle isotopic end-members as revealed from global OIB data, we must (1) remember our original assumptions that the primitive mantle (PM) soon after the core separation was compositionally uniform/homogeneous with the core playing a limited or no role in causing mantle isotopic heterogeneity; (2) not use OIB isotopes to conclude about the nature and compositions of ultimate source materials without understanding geochemical consequences of subduction zone metamorphism; and (3) ensure that models and hypotheses are consistent with the basic petrology and major/trace element geochemistry. | NIU Yaoling1,2,3 1 Department of Earth Sciences, Durham University, Durham DH1 3LE, UK 2 School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China 3 School of Earth and Space Sciences, Peking University, Beijing 100871, China | 2009 | Chinese Science Bulletin2009，54，22： | 23 |
| 20 | Study of ozone “weekend effect” in Shanghai显示文摘Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O_3) concentrations in Xujiahui are higher at week-ends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays. The possible chemical cause of ozone 'weekend effect' is that NO_2/NO ratio increases at weekends by 25.61% compared with those on weekdays. In addition, because of an average 12.13% reduction in NOx (NO + NO_2) in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate. The rate of ozone production is a function of VOCs and NOx in the atmosphere. VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the 'NOx-limited'. The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone 'weekend effect' in Xujiahui. Furthermore, combining with MICAPS cloud amount data, the fact that ozone 'weekend effect' in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone 'weekend effect' in Xujiahui of Shanghai. | TANG WenYuan1↑, ZHAO ChunSheng1, GENG FuHai1,2, PENG Li2, ZHOU GuangQiang2, GAO Wei2, XU JianMing2 & TIE XueXi2,3 1 Department of Atmospheric Science, School of Physics, Peking University, Beijing 100871, China 2 Atmospheric Chemistry Laboratory of Shanghai Meteorological Bureau, Shanghai 200030, China 3 Atmospheric Chemistry Division, NCAR, Boulder CO 80301, USA | 2008 | Science China Earth Sciences2008，51，9： | 23 |
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