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Relationship between δ^(13)C and index of ring width

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chinese Science Bulletin 1999年第S2期44卷 81-83页

1 Materials and methods THE tree-ring reported here is one of pine discs sampled at 3 2.0 m a.s.l. in Qongtelian Valley in the Tuomu’er Peak region in 1978. The local geographical and climate condition has been introduced in detail. An index series was obtained after the width of tree-rings on 5 different radii was measured andfitted by linear and negative exponential functional regression. Each annual ring has been separated on the whole to simultaneously measure △14 C and δ13 C of treerings. Cellulose was extracted by the standard chemical method, then oxidized by copper oxide to C02./sub>.Carbon isotopic analyses were performed with a Mat-2.2.mass spectrometer. Results are expressed in thestandard δ notation with respect to the PDB standard with a precision of 0.1‰. 2

关键词： tree rings δ13C index of ring width correlation climate changes.

Stable carbon isotopic composition of soil organic carbon in karst area in Central Guizhou, china

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chinese Science Bulletin 1999年第S2期44卷 87-88页

作者： ZHENG Leping~(1,2., LI Tingyu~2. wan guojiang~2. {2. Shijie~2.and OUYANG Ziyuan~2.1. Department of environmental Science and Engineering, Shanghai University, Shanghai 2.0072. china 2. state key Laboratory of environmental geochemistry, institute of geochemistry, chinese academy of sciences, guiyang 550002, china Department of environmental Science and Engineering Shanghai University Shanghai 200072 China state key Laboratory of {2. geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE stable carbon isotopic composition of soil organic carbon is a powerful tool for discussing the source ofsoil CO2.and the relationship of CO2.source and sink between soil CO2.and atmosphere CO2.and has beenwidely ... 详细信息

THE stable carbon isotopic composition of soil organic carbon is a powerful tool for discussing the source ofsoil CO2./sub> and the relationship of CO2./sub> source and sink between soil CO2./sub> and atmosphere CO2./sub> and has beenwidely studied. However, few similar researches have been done in karst area which comprises 15%global terrestrial area. Preliminary research results about the stable carbon isotopic composition of soil organic carbon in karst area are reported here. In April and August 1998, the samples were collected continuously at 5-cm intervals from 0 to -45cm depth in meadow soil profile described by Zheng and located in the Hongfong Lake area in the central Guizhou Plateau which lies in the central East-Asia karst area. CO2./sub> for δ13 C analysis was prepared

关键词： δ13C of soil organic carbon karst area Guizhou Province.

The seasonal and daily CO_2.concentration variance in karst meadow soil profile with depth in Central Guizhou, china

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chinese Science Bulletin 1999年第S2期44卷 93-94页

THE seasonal variance of soil CO2.concentration with depth in soil profile was widely studied. Few similarresearches on this topic have been done in karst area which comprises 15% global terrestrial area. In thisnote,... 详细信息

THE seasonal variance of soil CO2./sub> concentration with depth in soil profile was widely studied. Few similarresearches on this topic have been done in karst area which comprises 15% global terrestrial area. In thisnote, the research results about the seasonal and daily soil CO2./sub> concentration variance in karst area arereported. The soil gases were collected respectively by the sampling device at 2.0, 5,0, -5, -10,-15, -2., -35 and -45 cm from the land surface in meadow soil profile described by Zheng andlocated in the Hongfeng lake area in the central Guizhou Plateau which lies in the central East-Asia karstarea. Sampling time is in the morning, midday and at night in April, August and November, 1998 aswell as in January, 1999, respectively. Concentrations （volume percent） of CO2./sub> in soil gas samples

关键词： soil CO2 concentration karst area Guizhou Province.

Geochemical Speciation of Soil ~7Be, ^(137)Cs,^(2.6)Ra and ^(2.8)Ra as Tracers to Particle Transport

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Pedosphere 1997年第3期7卷 263-268页

作者： BAI ZHANGUO wan guojiang {2. CHANGSHENG wan XI and HUANG RONGGUI (institute of Soils and Fertilizers, chinese academy of Agricultural sciences, Beijing 100081 china)(state key Laboratory of environmental {12., institute of geochemistry, Chines institute of Soils and Fertilizers Chinese Academy of Agricultural Sciences Beijing 100081 China state key Laboratory of {2. geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

A brunisolic soil collected from an erosive forest land (HF-1-1) and a yellow soil from an accumulative shallow basin (HF-6-1) in the watershed of Lake Hongfeng (HF) were used for activity measurements of 7Be, 137Cs, 2.6Ra and 2.8Ra in different geochemical speciation. More than 85% of 7Be, 137Cs, 2.6Ra and 2.8Ra in the soils were bound to organic, Fe-Mn oxy-hydroxide and residual fractions. They could move with soil particles and be used as tracers for the erosion and/or accumulation of soil particles. 7Be geochemical speciation in the soils agreed with its trace for seasonal particle transport. 137Cs geochemical speciation was suitable for tracing soil particle accumulation and for sediment dating. 2.6Ra and 2.8Ra were combined in crystalline skeleton of clay minerals and mainly remained as residues in the soils and little was bound to the soluble, exchangeable and carbonate fractions. The differentiation of 2.6Ra/2.8Ra activity ratios in different geochemical fractions in the soils could be used as a parameter to trace accumulation and /or erosion of soil particles.

关键词： erosion trace geochemical speciation radionuclides soils

7~Be: A Geochemical Tracer for Seasonal Erosion of Surface Soil in Watershed of Lake Hongfeng, Guizhou, china

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Pedosphere 1996年第1期6卷 23-28页

作者： BAI ZHANGUO wan guojiang {2. CHANGSHENG wan XI HUANGRONGGUI P.H. SANTSCHIZ and M. BASKARANZ(1￣state key Lab. Of environmental geochemistry, institute of geochemistry, chinese academy of sciences,guiyang 550002 ({12.))(2.Department Of Marine Scien state key Lab. of {2. geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550005 China Department of Marine sciences Texas a K M University Galveston TX 77551 United States

e penetrative depth in undisturbed surface soil is within 4 mm.7￣Be activity shows exponential decrease with soil depth, which is expressed as a diffusion process.7￣Be penetrative depth in undisturbed surface soil is apparently deeper in the fall (0.2.-0.37 g cm￣(-2. than in the spring (0.11-0.2. g cm￣(-2. at the same site; Whereas, ￣7Be apparent activity at the top of surface soil is higher in the spring (0.3-2.2.Bq g￣(-1_) than in the fall (0.2.0.5 Bq g￣(-1) at the same site. The ￣7Be inventory (189-544 Bq m￣(-2. changes with both locations and seasons. Although the ￣7Be flux to the earth's surface increases with amount of precipitation, its maximum inventory in the soil profiles decreases to 30%-40% after the rainy period. Calculated by the diffusion equation, the erosion and accumulation rates of soil particles are agreeable with the observation in situ., which shows that the rates in fall are 1.5 times those in spring. The eroded soil particles almost all have been removed on the tablelands rather than transported into the drainage system. This indicstes that the soil erosion process in the karst region is only partial transportation within a short distance.

关键词： e erosion trace Lake Hongfeng watershed surface soil

Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system

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Journal of Forestry Research 2024年第3期35卷 175-188页

作者： Niu Zhu Jinniu wang Dongliang Luo Xufeng wang Cheng Shen {2. Wu {2. Zhang Binghui Tian Aihong Gai Chengdu institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China College of Resources and environmental sciences Gansu Agricultural UniversityLanzhou 730070People's Republic of China Mangkang Ecological Monitoring Station Tibet Ecological Security Barrier Ecological Monitoring NetworkQamdo 854500People's Republic of China Northwest institute of Eco environmental Resources Chinese Academy of SciencesLanzhou 730000People's Republic of China

Evapotranspiration is an important parameter used to characterize the water cycle of *** under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2.2. to October 2.2. in a core area of the Three Parallel Rivers in the Qing-hai-Tibet *** results show that the evapotranspira-tion peaked daily,the maximum occurring between 11:00 and 15:*** factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2.=0.487),and relative humidity the least(R^(2.=0.001).The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent *** energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale.

关键词： Evapotranspiration Energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau

Geochemical records of carbon in recent sediments of Erhai Lake, china: Implication of effects of the Himalayas uplift on global environmental changes

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chinese Science Bulletin 1999年第S2期44卷 123-124页

作者： wan guojiang~1, BAI Zhanguo~(1,2., {2. Haoran~1 and HUANG Ronggui~1 1. state key Laboratory of environmental geochemistry, institute of geochemistry, chinese academy of sciences, guiyang 550002, china 2. state key Laboratory of Plant Nutrition Research of chinese Ministry of Agriculture, institute of Soil and Fertilizer, chinese academy of Agricultural sciences, Beijing 100081, china

THE formation and uplift of the Himalayas and the Tibetan Plateau may have been responsible for the past150 Ma global environmental changes, resulting in the development of a three-tiered landform in southernchina. The Yunnan-Guizhou Plateau, as the middle tier in eastern slope of the Himalayas, has beencomplex environmental unit with great altitude gradients and plateau landform characters. Both monsoonsfrom the Pacific and the Indian resulting in apparent environmental changes on variable time scales influence it. environmental geochemical effect of low latitude-high altitude could be yielded, and well recorded in the geological bodies in this region. To build and verify a quantitative model of environmental evolution it is necessary to obtain high-resolution data of elemental cycles and mass equilibrium.

关键词： records sediments Erhai Lake Himalayas uplift global environmental changes.

Triboelectric nanogenerator hybrid array driven by multiform natural energies and its applications in self-powered cathodic protection

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Science china(Technological sciences) 2024年第3期67卷 878-890页

作者： SUN Weixiang YANG Di LUO ning LI Hao wang DaoAi School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China state key Laboratoryof Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Qingdao Center of Resource Chemistry and New Materials Qingdao 266100China

In view of the increasing energy shortage and environmental pollution, the collection of friction charges to achieve the conversion of various natural energies and provide in-situ cathodic protection for metals is a significant challenge. Here, we designed a dual device-structure TENG composite array with the triboelectric layer of linear siloxane-modified polyurethane(PU) coating. This array could achieve a comprehensive collection for multiple forms of nature energy and cathodic protection of metals in multi-weather conditions. For one thing, the wave-mode TENG based on tanker structure could collect wave energy and showed the output performance with a short-circuit current of 15.5 μA. For another thing, the droplet-mode TENG based on arc-shaped surface structure could collect raindrop kinetic energy and showed the output performance with a short-circuit current of 16.3 μA. Notably, the parallel array of wave-mode TENG(W-TENG) and droplet-mode TENG(D-TENG) could simultaneously collect wave energy and raindrop kinetic energy, which showed a short-circuit current of 30.7 μA. Besides, a selfpowered a cathodic protection system powered by the dual structure TENG array is assembled and the open-circuit potential drop of the carbon steel connected with the TENG array is about 450 mV. Compared with cathodic protection system powered by single structure TENG, the composite array could provide more effective corrosion resistance for marine equipment in rainy weather. Due to the characteristic for comprehensive collection of nature energy, the anti-corrosion system supplied by TENG parallel array possesses great application potential in the all-weather corrosion protection of metal machinery under complex marine conditions.

关键词： triboelectric nanogenerator hybrid structure array siloxane-modified polyurethane cathodic protection

Recent progress in CdS-based S-scheme photocatalysts

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Journal of Materials Science & Technology 2024年第4期171卷 162-184页

作者： Yajing Ren Yunfeng Li Guixu Pan ning wang Yan Xing Zhenyi Zhang College of environmental and Chemical Engineering Xi’an Polytechnic UniversityXi’an 710048China Jilin Provincial key Laboratory of Advanced Energy Materials Department of ChemistryNortheast Normal UniversityChangchun 130024China key Laboratory of New Energy and Rare Earth Resource Utilization of state Ethnic Affairs Commission Key Laboratory of Photosensitive Materials and Devices of Liaoning ProvinceSchool of Physics and Materials EngineeringDalian Minzu UniversityDalian 116600China

Photocatalytic technology with sunlight as driving force can convert solar energy into other energy sources for storage and further *** sulfide(CdS),as a typical reducing semiconductor of metal sulfides,represents an interesting research hotspot in photocatalysis due to its suitable bandgap(2.4 eV)for utilizing visible light and strong reducing ability for inducing surface catalytic ***,the photocatalytic performance of CdS is still limited by its fast carrier recombination and serious *** far,CdS semiconductor has been widely developed as a typical reducing photocatalyst in constructing novel S-scheme heterojunction to overcome the above *** this review,the de-sign concepts,basic principles,and charge transfer characteristics of CdS-based S-scheme heterojunction photocatalysts have been comprehensively *** advanced and effective characterization methods for studying the mechanism of CdS-based S-scheme heterojunction are analyzed in ***-thermore,we also summarize the typical applications of CdS-based S-scheme heterojunctions for water splitting,CO_(2. reduction,pollutant degradation,***,according to the current investigation sta-tus,some drawbacks in the current synthetic strategy,mechanism exploration,and application prospect of CdS-based S-scheme heterojunction are proposed,which need to be addressed by further expansion and innovative research.

关键词： Photocatalysis CdS semiconductor Heterojunction S-scheme Metal sulfide