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Atmospheric Methane over the Past 2000 Years from a Sub-tropical Ice Core, Central Himalayas

Journal of Mountain science 2010年第1期7卷 1-14页

作者： LI Jiule XU Baiqing YAO Tandong WANG Ninglian Ken MacClune laboratory of Tibetan Environment Changes and Land Surface Processes Chinese Academy of Sciences Beijing 100085 China state key laboratory of cryospheric science Chinese Academy of Sciences Lanzhou 730000 China Stable Isotope laboratory Institute ofArctic andAlpine Research University of Colorado Boulder Colorado CO 80303 USA

A high-resolution 2ooo-year methane record has been constructed from an ice core recovered at 7200 m a.s.1, on the Dasuopu Glacier in the central Himalayas. This sub-tropical methane record reveals an increasing trend in the concentration of methane during the industrial era that is similar to observations from polar regions. However, we also observed the differences in the atmospheric methane mixing ratio between this monsoon record and those from polar regions during pre-industrial times. In the time interval o N 1850 A.D., the average methane concentration in the Dasuopu ice core was 782±40 ppbv and the maximum temporal variation exceeded 200 ppbv. The difference gradient of methane concentration in Dasuopu ice core with Greenland and Antarctica cores are 66±40 ppbv and 107±40 ppbv, respectively. This suggests that the tropical latitudes might have acted as a major global methane source in preindustrial times. In addition, the temporal fluctuation of the pre-industrial methane records suggests that monsoon evolution incorporated with high methane emission from south Asia might be responsible for the relatively high methane concentration observed in the Dasuopu ice core around A.D. 800 and A.D. 1600. These results provide a rough understanding of the contribution of tropical methane source to the global methane budget and also the relationship betweenatmospheric methane and climate change.

关键词： climate change ice core air bubble atmospheric methane Dasuopu Glacier centralHimalayas

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Concentration and seasonal variation of 10Be in surface aerosols of Lhasa,Tibet

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science Bulletin 2010年第23期 2575-2581页

作者： HUANG Jie1,7,KANG ShiChang1,2,SHEN ChengDe3,CONG ZhiYuan1,LIU KeXin4,WANG Wei5 & LIU LiChao6 1 key laboratory of Tibetan Environment Changes and Land Surface Processes,Institute of Tibetan Plateau Research,chinese academy of sciences,Beijing 100085,china 2 state key laboratory of cryospheric science,chinese academy of sciences,lanzhou 730000,china 3 key laboratory of Isotope Geochronology and Geochemistry,Guangzhou Institute of Geochemistry,chinese academy of sciences,Guangzhou 510000,china 4 state key laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,china 5 Institute of Plateau Atmosphere and Environment sciences,Tibet Meteorological Bureau,Lhasa 850000,china 6 Cold and Arid Regions Environmental & Engineering Research Institute,chinese academy of sciences,lanzhou 730000,china 7 Graduate University of the chinese academy of sciences,Beijing 100049,china

Thirty samples of total suspended particles were collected at a site in western part of Lhasa,Tibet from August 2006 to July *** 10Be concentrations were determined by Accelerator Mass Spectrometer (AMS).Analysis of correlation between 10Be concentrations and meteorological factors revealed that the wet scavenging has little effect on 10Be.10Be can be used as a proxy of transport processes of the upper atmosphere over the Tibetan *** of correlation between 10Be concentrations and NCEP reanalysis data demonstrated that higher 10Be concentrations in spring were probably caused by the atmosphere exchange from stratosphere to troposphere during February to *** 10Be concentrations during August to September were consistent with the synchronous lower O3 values,suggestive of both 10Be and O3 were probably influenced by the atmosphere exchange from troposphere to stratosphere.

关键词： 10Be concentration background value seasonal variation Lhasa

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Review of several problems on the study of eco-hydrological processes in arid zones

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chinese science Bulletin 2002年第5期47卷 353-360页

作者： ZHAO Wenzhi & CHENG GuodongCold and Arid Regions Environmental and Engineering Research Institute, chinese academy of sciences, lanzhou 730000, china state key laboratory of Frozen Soil Engineering, chinese academy of sciences, lanzhou 730000, china Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China state key laboratory of Frozen Soil Engineering Chinese Academy of Sciences Lanzhou China

Ecosystem degradation is a common and cardinal environmental problem in arid zones. The change in the eco-hydrological processes is the basic cause responsible for such a problem. The study on the eco-hydrological processes in arid zones has become a forefront and focus of the eco-environmental research. Recent studies on eco-hydrological processes in arid zones show that the primary vegetation pattern and its eco-hydrological effect are of the most stable state of the ecosystem in arid zones. Special water absorption ways of plants in arid zones and the hydraulic lift and reverse hydraulic lift functions of some plants are the key mechanisms to maintain the stability of the ecosystem in arid zones. In the case of water shortage, ensuring ecological water requirement and maintaining proper ecological ground- water table are the prerequisite to keep healthful operation of the ecosystem in arid zones. The paper reviews some advances in the study of eco-hydrological processes in arid zones. It puts

关键词： arid zone vegetation pattern eco-hydrological effect hydraulic lift plant water source ecological water requirement.

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The consideration and choice on exploiting energy source

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chinese science Bulletin 1999年第18期44卷 1717-1728页

作者： WANG Xianbinstate key laboratory of Gas Geochemistry, lanzhou Institute of Geology, chinese academy of sciences , lanzhou 730000, china state key laboratory of Gas Geochemistry Lanzhou Institute of Geology Chinese Academy of Sciences Lanxhou China

A problem of petroleum energy crisis will probably be faced in the late 21st century. It is impossible to discover the giant oil fields again based on the traditional knowledge and theory of petroleum geology. From the global development point of view as well as the situation in china, the five choices of energy source in the future are to ( i ) extend the field of exploration in conventional petroleum and natural gas source, and exploit oil-gas source in ocean and

关键词： energy sources in the future unconventional gas coal hydrogen controllable nuclear fusion 3He source on the moon.

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Characterization and Tribological Behavior of Octadecene,Dodecene and Undecenoic Acid Films on Si Substrate

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Journal of Materials science & Technology 2005年第5期21卷 671-674页

作者： Jinfang ZHOU+ and Shengrong YANGstate key laboratory of Solid Lubrication, lanzhou Institute of Chemical Physics, chinese academy of sciences, lanzhou730000, china state key laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

The films of octadecene, dodecene, and undecenoic acid were prepared on H-terminated Si surface in the presence of ultraviolet irradiation. The resulted films were characterized with water-contact angle measurement and infrared spectroscopy. The friction-reducing behavior of the prepared films was examined on a static-dynamic friction coefficient measurement apparatus and on an atomic force microscope. It was found that all the reacted films on the Si substrate showed good friction-reducing ability; especially, the film of the octadecene exhibited the best friction-reducing ability. This was attributed to the transfer of the reacted films onto the counter face with formation of a transfer film on the counterpart surface, which led to the transformation of the sliding between the reacted films and the hard ceramic to fiat between the reacted films and its transfer film on the counterpart surface. The macroscopic and microscopic friction behaviors of the prepared films were dependent on their molecular chain lengths. Thus the octadecene reacted film with the highest degree of ordering arrangement showed the best friction-reducing and antiwear abilities in sliding against Si3N4.

关键词： Alkese Reaction film Hydrogen-terminated silicon Tribological behavior

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Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors

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science china(Technological sciences) 2010年第7期53卷 1957-1966页

作者： DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil Engineering, lanzhou University of Technology, lanzhou 730050, china 2 state key laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, chinese academy of sciences, lanzhou 730000, china 1. College of Civil Engineering Lanzhou University of Technology Lanzhou 730050 China2. State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3D nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.

关键词： frame supporting structure with prestressed anchor slope dynamic calculation model seismic performance seismic design

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Spatial distribution of 10m firn temperature in the Antarctic Ice Sheet

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science china Earth sciences 2011年第5期54卷 655-666页

作者： WANG YeTang1,3 & HOU ShuGui2,3 1 Shandong Marine Fisheries Research Institute,Yantai 264006,china 2 MOE,key laboratory for Coast and Island Development,School of Geographic and Oceanographic sciences,Nanjing University,Nanjing 210093,china 3state key laboratory of cryospheric science,Cold and Arid Regions Environmental and Engineering Research Institute,chinese academy of sciences,lanzhou 730000,china 1. Shandong Marine Fisheries Research Institute Yantai 264006 China3. State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China2. MOE Key Laboratory for Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

A database of Antarctic 10 m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate. Slopes from a high-resolution digital elevation model and the main ice divide were used to delineate main drainage sectors across Antarctica. In each drainage sector, a quantitative relationship between temperature and latitude, longitude and altitude was established using available tim temperature data. Quantitative relationships incorporating other factors affecting Antarctic air temperature such as atmospheric circulation and small-scale to- pography were used to derive a 10-km resolution grid map of surface temperature. The resulting temperature patterns presented a reasonable depiction of both large and small-scale variations in Antarctic 10 m firn temperature. This map is useful for many spatial variation studies, Antarctic ice sheet models, and comparison with satellite-derived temperature data and outputs of atmospheric general circulation models.

关键词： Antarctica 10 m firn temperature spatial distribution

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Nonlinear local Lyapunov exponent and atmospheric predictability research

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science china Earth sciences 2006年第10期49卷 1111-1120页

作者： CHEN Baohua1, LI Jianping1,2 & DING Ruiqiang2 1. College of Atmospheric sciences, lanzhou University, lanzhou 730000, china 2. state key laboratory of Numerical Modeling for Atmospheric science and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, chinese academy of sciences, Beijing 100029, china 1. College of Atmospheric sciences Lanzhou University Lanzhou 730000 China 2. state key laboratory of Numerical Modeling for Atmospheric science and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Because atmosphere itself is a nonlinear system and there exist some problems using the linearized equations to study the initial error growth, in this paper we try to use the error nonlinear growth theory to discuss its evolution, based on which we first put forward a new concept: nonlinear local Lyapunov exponent. It is quite different from the classic Lyapunov exponent because it may characterize the finite time error local average growth and its value depends on the initial condition, initial error, variables, evolution time, temporal and spatial scales. Based on its definition and the at-mospheric features, we provide a reasonable algorithm to the exponent for the experimental data, obtain the atmospheric initial error growth in finite time and gain the maximal prediction time. Lastly, taking 500 hPa height field as example, we discuss the application of the nonlinear local Lyapunov exponent in the study of atmospheric predictability and get some reliable results: atmospheric predictability has a distinct spatial structure. Overall, predictability shows a zonal distribution. Prediction time achieves the maximum over tropics, the second near the regions of Antarctic, it is also longer next to the Arctic and in subtropics and the mid-latitude the predictability is lowest. Particularly speaking, the average prediction time near the equation is 12 days and the maximum is located in the tropical Indian, Indonesia and the neighborhood, tropical eastern Pacific Ocean, on these regions the prediction time is about two weeks. Antarctic has a higher predictability than the neighboring latitudes and the prediction time is about 9 days. This feature is more obvious on Southern Hemispheric summer. In Arctic, the predictability is also higher than the one over mid-high latitudes but it is not pronounced as in Antarctic. Mid-high latitude of both Hemispheres (30°S―60°S, 30°―60°N) have the lowest predictability and the mean prediction time is just 3―4 d. In addition, predictab

关键词： nonlinear, local, Lyapunov exponent, atmospheric predictability, maximal prediction time.

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Effects of chlorothalonil and carbendazim on nitrification and denitrification in soils

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Journal of Environmental sciences 2009年第4期21卷 458-467页

作者： LANG Man, CAI Zucong state key laboratory of Soil and Sustainable Agriculture, Institute of Soil science, chinese academy of sciences,Nanjing 210008, china [a]state key laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.

关键词： fungicide nitrification denitrification chlorothalonil carbendazim

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Dry electrode for the measurement of biopotential signals

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science china(Information sciences) 2011年第11期54卷 2435-2442页

作者： WANG Yu 1,2,PEI WeiHua 2,GUO Kai 2,GUI Qiang 2,LI XiaoQian 2,CHEN HongDa 2 & YANG JianHong 11 Institute of Microelectronics,School of Physical science and Technology,lanzhou University lanzhou 730000,china 2 state key laboratory on Integrated Optoelectronics,Institute of Semiconductors,chinese academy of sciences,Beijing 100083,china 1. Institute of Microelectronics School of Physical Science and Technology Lanzhou University Lanzhou 730000 China2. State Key Laboratory on Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

This paper introduces a kind of silicon-based dry electrode for measuring biological *** uses microneedle arrays to penetrate into the stratum corneum to reduce skin *** dry electrode requires neither skin preparation nor the electrolytic gel,is easy to use and causes no skin *** different technologies are chosen to manufacture microneedle arrays of dry *** is deep dry etching combined with isotropic wet *** other is mechanical dicing combined with chemical wet etching (including isotropic wet etching and anisotropic wet etching).Microneedle arrays are coated with metal and divided into 25 mm 2 as dry electrode *** testing shows that the impedance value of dry electrode can be comparable with that of commercial electrode in the 20 Hz-10 kHz frequency *** steady-state visual evoked potential recording and analysis prove that the dry electrode can be used to detect electroencephalography.

关键词： dry electrode microneedle array dry etching wet etching EEG

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