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1Numerical Simulation on Climate Effects of Freezing-Thawing Processes Using CCM3显示文摘A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.Chenghai Wang1,2*,Guodong Cheng3,Aijun Deng4,Wenjie Dong5 1.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 2.State Key Laboratory of Cryosphere Sciences,Cold and Arid Regions Environmental and Engineering Research Insti-tute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 3.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 4.Department of Meteorology,The Pennsylvania State University,University Park,PA 16802 5.State Key Laboratory of Earth Surface Processes and Ecology Resource,Beijing Normal University,Beijing 100875,China Chenghai Wang1,2*,Guodong Cheng3,Aijun Deng4,Wenjie Dong5 1.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 2.State Key Laboratory of Cryosphere Sciences,Cold and Arid Regions Environmental and Engineering Research Insti-tute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 3.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 4.Department of Meteorology,The Pennsylvania State University,University Park,PA 16802 5.State Key Laboratory of Earth Surface Processes and Ecology Resource,Beijing Normal University,Beijing 100875,China 2008Research in Cold and Arid Regions2008,,1:44
2Simulation of energy and water balance in Soil-Vegetation-Atmosphere Transfer system in the mountain area of Heihe River Basin at Hexi Corridor of northwest China显示文摘In the mountain area of inland Heihe River Basin at Hexi Corridor of northwest China during the vegetation growing season from May to September, the Simultaneous Heat and Water (SHAW) model of Soil-Vegetation-Atmosphere Transfer (SVAT) system is applied to simulating and studying energy and water balance of the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope and the grassland at the sun-facing slope. The simulation of energy balance indicates that net radiation of the grass- land at the sun-facing slope is more than that of the Picea crassifolia forest and the grassland by the forest at the shaded slope. The energy outgoing components are the first latent heat and next sensible heat from the grassland both at the shaded slope and the sun-facing slope, but those at the former are less. The energy outgoing components are the first sensible heat and next latent heat from the Picea crassifolia forest. The composition and distribution of energy in the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope make the soil layer receive less energy, which therefore, especially the forest possesses the energy conditions for soil water conservation. The simulation of water balance indicates that the water loss of the grassland at the sun-facing slope is mainly caused by soil evaporation, while evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is less than that of the grassland at the sun-facing slope. Half of the evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is consumed by transpiration. After precipitation, the soil water storage is increased much more for the Picea crassifolia forest and also more for the grassland by the forest at the shaded slope. Therefore the shaded slope vegetation, especially the forest is favorable for soil water storage.KANG Ersi1, CHENG Guodong1, , SONG Kechao1, JIN Bowen1, , LIU Xiande3 2 3 & WANG Jinye3 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2. State Key Laboratory of Frozen Soil Engineering, Chinese Academy of Sciences, Lanzhou 730000, China 3. Academy of Water Resources Conservation Forest of Qilian Mountains, Gansu Province, Zhangye 734000, China 2005Science China Earth Sciences2005,48,4:25
3Results of Carbon Ion Radiotherapy for Skin Carcinomas in 33 Patients显示文摘Purpose: To evaluate outcome and toxicity after carbon ion radiotherapy (RT) in skin carcinomas. Patients and Methods: Between November 2006 to September 2008,H.Zhang1,2, S.Li3, X.H.Wang 4, Q.Li1,2, S.H.Wei3, L.Y.Gao4, W.P.Zhao1,2, Z.G.Hu1, R.S.Mao1, H.S.Xu1, H.Y.Cai 4, Y.Y.Yue3, G.Q.Xiao1 1Institute of Modern Physics, CAS, Lanzhou 730000, China 2 Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000, China 3 The General Hospital of Lanzhou Command, Lanzhou 730050, China 4 Tumor Hospital of Gansu Province, Lanzhou 730050, China 2009生物物理学报2009,25,S1:23
4Effect of 5-Aza-2'-deoxycytidine on the P16 tumor suppressor gene in hepatocellular carcinoma cell line HepG2显示文摘INTRODUCTIONHepatocellular carcinoma (HCC) is one of the mostcommon human malignancies worldwide[1,2], and isclosely associated with infection of HBV and HCVand contamination of aflatoxin B1[3-6]. Althoughthe molecular mechanisms of hepatocarcinogenesisremain poorly understood, an increasing number ofgenetic abnormalities have been recognized[7-10],for example, the p16 gene[11,12] the p53gene[13-18], the E-cadherin gene[19], and the c-mycgene[20].Li Hua Liu1 Wen Hua Xiao2 Wei Wen Liu3 1Department of Oncology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China (now working in Department of Gastroenterology, General Hospital of PLA, Lanzhou 730050, Gansu Province, China)2Department of Oncology3Department of Gastroenterology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China 2001World Journal of Gastroenterology2001,7,1:21
5Genetic diversity in Chinese modern wheat varieties revealed by microsatellite markers显示文摘Genetic diversity of 1680 modern varieties in Chinese candidate core collections was analyzed at 78 SSR loci by fluorescence detection system. A total of 1336 alleles were detected, of which 1253 alleles could be annotated into 71 loci. For these 71 loci, the alleles ranged from 4 to 44 with an average of 17.6, and the PIC values changed from 0.19 to 0.89 with an average of 0.69. (1) In the three genomes of wheat, the average genetic richness was B>A>D, and the genetic diversity indexes were B>D>A. (2) Among the seven homoeologous groups, the average genetic richness was 2=7>3>4>6>5>1, and the genetic diversity indexes were 7>3>2>4>6>5>1. As a whole, group 7 possessed the highest genetic diversity, while groups 1 and 5 were the lowest. (3) In the 21 wheat chromosomes, 7A, 3B and 2D possessed much higher genetic diversity, while 2A, 1B, 4D, 5D and 1D were the lowest. (4) The highest average genetic diversity index existed in varieties bred in the 1950s, and then it declined continually. However, the change tendency of genetic diversity among decades was not greatly sharp. This was further illustrated by changes of the average genetic distance between varieties. In the 1950s it was the largest (0.731). Since the 1960s, it has decreased gradually (0.711, 0.706, 0.696, 0.695). The genetic base of modern varieties is becoming narrower and narrower. This should be given enough attention by breeders and policy makers.HAO Chenyang, WANG Lanfen, ZHANG Xueyong, YOU Guangxia, DONG Yushen, JIA Jizeng, LIU Xu, SHANG Xunwu, LIU Sancai & CAO Yongsheng Key Laboratory of Crop Germplasm & Biotechnology, MOA, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China Agronomy College, Gansu Agricultural University, Lanzhou 730070, China 2006Science China(Life Sciences)2006,49,3:19
6Effect of areca on contraction of colonic muscle strips in rats显示文摘AIM: To investigate the effects of areca on the contractileactivity of isolated colonic muscle strips in rats andmechanism involved.METHODS: Each strip (LMPC, longitudinal muscle ofproximal colon; CMPC, circular muscle of proximal colon;LMDC, longitudinal muscle of distal colon; CMlC, circularmuscle of distal colon. ) was suspended in a tissue chambercontaining 5 mL Krebs solution (37 ℃), bubbledcontinuously with 950 mL@ L-1 O2 and 50 mL@ L-1 CO2 . Themean contractile amplitude (A), the resting tension (T),and the contractile frequency (F) were simultaneouslyrecorded on recorders.RESULTS: Arsca dose dependently increased the meancontractile amplitude, the resting tension of proximal anddistal colonic smooth muscle strips in rats ( P < 0.05). Italso partly increased the contractile frequency of colonicsmooth muscle strips in rats ( P < 0.05). The effects werepartly inhibited by atropine (the resting tension of LMPCdecreased from 0. 44 ± 0. 12 to 0. 17 ± 0.03; the restingtension of LMDC decreased from 0.71 ± 0.14 to 0.03 ± 0.01;the mean contractile amplitude of LMPC increased from -45.8 ± 7.2 to -30.5 ± 2.9; the motility index of CMDC decreasedfrom 86.6± 17.3 to 32.8 ± 9.3; P< 0.05 vs areca), but theeffects were not inhibited by hexamethonium (P> 0.05).CONCLUSION: Areca stimulated the motility of isolatedcolonic smooth muscle strips in rats. The stimulation ofareca might be relevant with M reoeptor partly.Dong-Ping Xie Lian-Bi Chen,Department of Physiology,Medical College,Shandong University,Jinan 250012,Shandong Province,China Wei Li Song-Yi Qu Tian-Zhen Zheng,Department of Physiology,Lanzhou Medical College,Lanzhou 730000,Gansu Province,China Ying-Li Yang,Northwest Normal University,Lanzhou 730070,Gansu Province,China Yong-Hui Ding Yu-Ling Wei,Drug Control Institute of Gansu Province,Lanzhou 730000,Gansu Province,China 2002World Journal of Gastroenterology2002,8,2:18
7Photochemical pollution in Lanzhou, China - A case study显示文摘The photochemical air pollution in Xigu district of Lanshou city, Gansu Province was studied during a period of 1981-1984. The extremely high NMHC/NOx ratio and ozone level elevation after rain have been noticed. A series of outdoor and indoor reaction chamber simulation experiments conducted in order to understand the specific conditions. The ozone formation under NMHC/NOx condition and the possible reason for high ozone concentration after rain are discussed.Tang Xiaoyan , Li Jinglong, Dong ZhenXing, Wang Yuying,Wang Wenxing , Qi Liwen, Liu Xiling, Zhang Yutian, Zhang Xuejin,Tian Bingshen, Jin Suwen , Yang Lingqing and Zhang Yixin Department of Technical Physics,Peking University, Beijing, China. Chinese Reaearch Academy of Eavironmental Sciences, Beijing,China. Gansu Provincial Environmental Research Institute, Lanshou, China. Lanshou Petrochemical Engineering Institute, Lanshou, China. 1989Journal of Environmental Sciences1989,1,1:15
8Temperature and precipitation trends in Minqin Desert during the period of 1961-2007显示文摘This paper analyzed the data of temperature and precipitation in Minqin,typical desert area in north-west China,during the period of 1961 2007 by linear regression.The result indicated that the increasing rate of the mean annual temperature in Minqin was higher than that of the average of China;and the temperature in February increased by 3.01oC averagely in the past 47 years.The climate in Minqin displayed an evident warming trend.However,there was no evidently increasing trend of precipitation in the past 47 years,and drought occurred during the whole growing season.ShuJuan ZHU1,2,3,ZhaoFeng CHANG1,2,3 1 Gansu Minqin National Field Observation & Research Station on Ecosystem of Desertified Rangeland,Minqin 733300,China 2 Key Laboratory of Desertification Combating of Gansu Province,Lanzhou 733070,China 3 Gansu Desert Control Research Institute,Lanzhou 733070,China 2011Journal of Arid Land2011,3,3:14
9Comparison of sensible and latent heat fluxes during the transition season over the western Tibetan Plateau from reanalysis datasets显示文摘The sensible and latent heat fluxes during the transition season over the western Tibetan Plateau from the NCEP-1 (NCEP/NCAR Reanalysis 1), AR-Ⅱ (NCEP-DOE Reanalysis 2) and ERA40 reanalysis datasets were compared and analyzed. The results show that the phase change in soil moisture has a significant effect on the sensible and latent heat fluxes over the western Tibetan Plateau (TP) due to the freezing-thawing processes during the transition from the dry to the wet period. The uncertainties in the sensible and latent heat fluxes over the western TP are quite high in the reanalysis data, and depend largely on the success of the soil moisture simulations in the models. Improving the hydrological process simulations in the land-surface models in seasonally frozen ground and in the active frozen soil layer may be an effective way of enhancing the reliability of the surface heat fluxes from the reanalysis data over the Tibetan Plateau.Yang Cui, Chenghai Wang Disaster Reduction Key Laboratory of Gansu Province, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China 2009Progress in Natural Science:Materials International2009,19,6:13
10Spectrofluorimetric determination of terbium(Ⅲ) by fluorescence enhancement system of Tb-TPA-Triton X-100 by La^(3+)显示文摘The phenomenon of fluorescence enhancement for the system of terbium(Ⅲ) with terephthalic acid (benzene-1,4-dicarboxylic acid (TPA)) in the presence of an excess of La^3+ in Triton X-100 aqueous solution has been studied. The fluorescence intensity of Tb^Ⅲ-TPA system can be greatly increased by La^3+. The intermolecular transfer of energy was responsible for the mechanism of the fluorescence enhancement. Triton X-100 plays an imporlant role for the stabilization of the system. The system, having the maximum excitation and emission wavelengths at 256nm and 546nm, respectively,shows a constant fluorescence intensity over the pH range between 4-6. The fluorescence intensity is a linear function of Tb^3+ concentration in the range of 1.00×10^-8 -2.56× 10^-5 mol·L^-1 and the limit of detection is 5.00×10^-9 mol·L^-1.ZHAO Guohu and ZHAO JunBasic Science Department, Gansu Agricultural University, Lanzhou 730070, China (Received 2002-04-29) 2003Rare Metals2003,22,2:9
11Rainfall interception by sand-stabilizing shrubs related to crown structure显示文摘On the edge of the Tengger Desert in northern China,revegetation has changed the landscape from moving dunes to stabilized dunes covered by shrubs,which further modifies the pattern of rainfall redistribution.To study rainfall interception loss by shrubs and its relationship to rainfall properties and crown structure,throughfalls passing through crowns of Artemisia ordosica Krash.and Caragana korshinskii Kom.were measured using nine PVC cups under the canopy of each of the two shrubs during 73 rain events over a three-year period,with total rainfall of 260.9 mm.Interception losses of gross rainfall by A.ordosica and C.korshinskii account for 15% and 27% of the total on a crown area basis,and 6% and 11% on a ground area basis,respectively.Individual throughfall(T) and interception(I) were significantly related to rainfall amount(Pg),duration(D),and intensity(R).Ratios of throughfall to rainfall(T/Pg) and interception to rainfall(I/Pg) were not only significantly related to Pg,D,and R,but also to shrub species,and interactions of species with crown volume(CV) and leaf area index(LAI).Under most rain events,interceptions by C.korshinskii with greater CV and LAI were significantly higher than those by A.ordosica,and more rainfall interception occurred at locations closer to the stems of the two shrubs.For C.korshinskii,I/Pg had a significant positive linear relation with CV and LAI,while T/Pg had a significant negative linear relation with them.CV has a greater influence on T/Pg and I/Pg than does LAI.Using a regression method,canopy water storage capacities are estimated to be 0.52 and 0.68 mm,and free throughfall coefficient to be 0.62 and 0.47 for A.ordosica and C.korshinskii,respectively.ZhiShan Zhang 1*,XinRong Li 1,XueJun Dong 2,XiaoHong Jia 1,MingZhu He 1,HuiJuan Tan 1 1.Shapotou Desert Research and Experiment Station,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China.2.Central Grasslands Research Extension Center,North Dakota State University,Streeter,ND 58483,USA. 2009Research in Cold and Arid Regions2009,1,2:9
12Expression of liver cancer associated gene HCCA3显示文摘AIM: To study and clone a novel liver cancer reisted gene,and to explore the molecular basis of liver cancer genesis.METHODS: Using mRNA differential display polymerasechain reaction (DDPCR), we investigated the difference of mRNA in human hepatocellular carcinoma (HCC) and paired surrounding liver tissues, and got a gene probe. By screening a human placenta cDNA library and genomic homologous extend, we obtained a full-length cDNA named HCCA3. We analyzed the expression of this novel gene in 42pairs of HCC and the surrounding liver tissues, and distribution in human normal tissues by means of Northern blot assay.RESULTS: A full-length cDNA of liver cancer associated gene HCCA3 has been submitted to the GeneBank nucleotide sequence databases ( Accession No. AF276707 ). The positive expression rate of this gene was 78.6% (33/42) in HCC tissues, and the clinical pathological data showed that the HCCA3 was closely associated with the invasion of tumor capsule ( P = 0.023) and adjacant small metastasis satellite nodules lesions ( P= 0.041). The HCCA3 was widely distributed in the human normal tissues, which was intensively expressed in lungs, brain and colon tissues,while lowly expressed in the liver tissues.CONCLUSION: A novel full-length cDNA was cloned and differentiated, which was highly expressed in liver cancer tissues. The high expression was closely related to the tumor invasiveness and metastasis, that may be the late heredited change in HCC genesis.Zheng-Xu Wang~1 Gui-Fang Hu~1 Hong-Yang Wang~2 Meng-Chao Wu~2 1 Department of General Surgery,Chinese PEA General Hospital of Lanzhou Military Command,Lanzhou 730050,Gansu Province,China2 Eastern Hepatobilliary Surgical Hospital,Second Military Medical University,Shanghai 200438,China 2001World Journal of Gastroenterology2001,7,6:9
13羊肚菌发酵液对小鼠抗疲劳作用试验研究显示文摘本研究对羊肚菌发酵液的抗疲劳作用进行了动物实验。结果表明,羊肚菌发酵液能明显提高机体糖原储备(肌糖原和肝糖原),使小鼠血红蛋白含量升高,血乳酸含量降低,小鼠运动能力和耐疲劳能力显著加强。Yun Jianmin (Department of Food Engineering,Gansu Agricultural University,Lanzhou 730070,China) 1997卫生研究1997,26,5:8
14Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring显示文摘Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2008 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mongolian grassland, under the condition of spring unstable stratification of the surface layer, dependence of the similarity function of turbulent intensity on stratification stability follows a '2/3 power law'. The structural function is a constant under the neutral stratification condition, and complicated under the stable condition. The calculated turbulent intensity has a close correlation with the observed one, which verifies the accuracy of the similarity functions and the suitability of the theorem of turbulent intensity in the grassland region.YUE Ping1,2,3, NIU ShengJie2, HU YinQiao4 & ZHANG Qiang1 1 Key Laboratory of Arid Climate Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climate Change and Reducing Disaster of CMA, Institute of Arid Meteorology, CMA, Lanzhou 730020, China 2 Nanjing University of Information Science and Technology, Nanjing 210044, China 3 Zhangye National Meteorological Observatory, Zhangye 734000, China 4 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, China 2010Science China Earth Sciences2010,53,5:7
15THE RELATIONSHIP BETWEEN TROPICAL PACIFIC SEA SURFACE TEMPERATURE AND SUMMER RAINFALL OVER NORTHWEST CHINA显示文摘In this paper,the data of summer precipitation in Northwest China were expanded by means of EOF.According tomajor eigenvectors in expansion the area of Northwest China was divided into four natural rainfall regions.Amongthem the region of greatest precipitation variability is found over the East Qinghai-North Shaanxi region,includingEast Qinghai,Central and East Gansu,Ningxia and North Shaanxi.There is apparent teleconnection between the firstand second time-dependent coefficients in EOF expansion and the tropical Pacific SST in the corresponding period andearlier months.The variation of the east tropical Pacific SST in winter and spring is able to predict precipitation trend ofNorthwest China next summer.Moreover,in the El Nino years precipitation trend is opposite to the following year,andthe region from East Qinghai to North Shaanxi is most sensitive.Zhu Bingyuan Li Dongliang Gansu Meteorological Bureau,Lanzhou 730020 1992Acta meteorologica Sinica1992,6,4:7
16Geochemical Characteristics and Origin of Natural Gases in the Qaidam Basin,China显示文摘Sixty-five natural gas samples were collected from 19 oil-gasfields in the Qaidam basin, China. The chemical composition and carbon isotope values of the samples were measured, and the geochemical characteristics and origin of the natural gases were studied. The gases can be divided into biogenic gases, sapropelic oil-type gases, mixed type oil-type gases, coal-type gases and mixed gas. The δ13C1 values of the biogenic gases are very small and the C2+ contents of them are very low, ranging from -68.2‰ to -61.8‰ and 0.06% to 0.20% respectively. They have heavy δD and δ13CCO2, showing a CO2 reduction pathway. They are distributed in the East depression region and derived from the Quaternary source rocks. The sapropelic oil-type gases have small δ13C2 values and high C2+ ranging from -36.6‰ to -28.6‰ and from 33.01% to 47.15% respectively. The mixed type oil-type gases have δ13C2 values and C2+ contents varying from -28.6‰ to -24.8‰ and from 4.81% to 26.06% respectively. Both sapropelic oil-type gases and mixed type oil-type gases are associated with oil-type oils, distributed in the West depression region and derived from the Tertiary saltwater lacustrine sapropelic source rocks and humic source rocks respectively. The δ13C2 values of the coal-type gases are extremely high and the C2+ contents are very low, changing from -23.3‰ to -12.5‰ and from 0.06% to 18.07% respectively. The coal-type gases in the Nanbaxian gasfield and the Lenghu oil-gasfields in the North fault block belt are derived from the Middle Jurassic coal-measures source rocks, whereas those in the West depression region are derived from the Tertiary saltwater lacustrine humic source rocks. Compared with some other basins in China, the natural gases there have obviously heavier δ13C due to the heavier δ13C of different types of kerogens of the Tertiary saltwater lacustrine source rocks in the West depression region of the basin. The mixing of natural gases is common in the West depression region, but the mixed gases are formed by sapropelic oil-type gases, mixed type oil-type gases or coal-type gases, respectively, of different levels of maturity. Most of the sapropelic oil-type gases and mixed type oil-type gases in the west part are thermally immature and low-mature, but the coal-type gases in the West depression region and the North fault block belt are mature and high- to over-mature.ZHANG Xiaobao, HU Yong, DUAN Yi, MA Liyuan, MENG Zifang, HE Peng,ZHOU Shixin and PENG DehuaState Key Laboratory of Gas Geochemistry, Lanzhou Institute of Geology, Chinese Academy ofSciences, Lanzhou, Gansu 730000 Research Institute of Petroleum Exploration and Development, Qinghai Petroleum Company,CNPC, Dunhuang, Gansu 736200 2003Acta Geologica Sinica(English Edition)2003,77,1:6
17Theorem of turbulent intensity and macroscopic mechanism of the turbulence development显示文摘Turbulence is one of the most common nature phenomena in everyday experience, but that is not adequately understood yet. This article reviews the history and present state of development of the turbulence theory and indicates the necessity to probe into the turbulent features and mechanism with the different methods at different levels. Therefore this article proves a theorem of turbulent transpor- tation and a theorem of turbulent intensity by using the theory of the nonequilibrium thermodynamics, and that the Reynolds turbulence and the Rayleigh-Bénard turbulence are united in the theorems of the turbulent intensity and the turbulent transportation. The macroscopic cause of the development of fluid turbulence is a result from shearing effect of the velocity together with the temperature, which is also the macroscopic cause of the stretch and fold of trajectory in the phase space of turbulent field. And it is proved by the observed data of atmosphere that the phenomenological coefficient of turbulent in- tensity is not only a function of the velocity shear but also a function of temperature shear, viz the sta- bility of temperature stratification, in the atmosphere. Accordingly, authenticity of the theorem, which is proved by the theory of nonequilibrium thermodynamics, of turbulent intensity is testified by the facts of observational experiment.HU YinQiao1,2, CHEN JinBei3,4 & ZUO HongChao2 1 Gansu Province Key laboratory of Arid Climatic Change and Reducing Disaster, Cold and Arid Regions Environment and Engi- neering Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2 State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Beijing 100029, China 3 Atmospheric Science College, Lanzhou University, Lanzhou 730000, China 4 Resource Environment Department, Lanzhou Agriculture University, Lanzhou 730060, China 2007Science China Earth Sciences2007,50,5:5
18The cooling effect of crushed rock structures on permafrost under an embankment显示文摘Based on the analysis and comparison of soil temperature, thermal regime and permafrost table under the experimental embankment of crushed rock structures in Beiluhe, results show that crushed rock structures provide an extensive cooling effect, which produces a rising permafrost table and decreasing soil temperatures. The rise of the permafrost table under the embankment ranges from an increase of 1.08 m to 1.67 m, with an average of 1.27 m from 2004 to 2007. Mean annual soil temperatures under the crushed rock layer embankment decreased significantly from 2005 to 2007, with average decreases of ?1.03 °C at the depth of 0.5 m, ?1.14 °C at the depth of 1.5 m, and ?0.5 °C at the depth of 5 m. During this period, mean annual soil temperatures under the crushed rock cover embankment showed a slight decrease at shallow depths, with an average decrease of ?0.2 °C at the depth of 0.5 m and 1.5 m, but a slight rise at the depth of 5 m. After the crushed rock structures were closed or crammed with sand, the cooling effect of the crushed rock layer embankment was greatly reduced and that of the crushed rock cover embankment was just slightly reduced.QingBai Wu*, MingYong Li, YongZhi LiuState Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China. 2009Research in Cold and Arid Regions2009,1,1:4
19The ecohydrology of the soil-vegetation system restoration in arid zones: a review显示文摘Arid zones, which cover approximately 40 percent of the earth's land surface, support complicated and widely varied ecological systems. As such, arid zones are an important composition of the global terrestrial ecosystem, and water is the key and abiotic lim-ited factor in ecosystem-driven processes in these areas. Ecohydrology is a new cross discipline that provides, in an objective and comprehensive manner, novel ideas and approaches to the evaluation of the interaction and feedback mechanisms involved in the soil-vegetation systems in arid zones. In addition, ecohydrology provides a theoretical basis of ecological restoration that is cen-tered on vegetation construction. In this paper, long-term monitoring and local observations in the transitional belt between a de-sertified steppe and a steppified desert at the Shapotou Desert Research and Experiment Station, Tengger Desert, in northern China, were evaluated. The primary achievements and related research progress regarding ecohydrology in arid zones were analyzed and summarized, as a keystone, and the response of soil ecohydrological processes to the changes in the species composition, structure, and function of sandland vegetation was discussed. Meanwhile, the long-term ecological effects and mechanism of regulation of vegetation on soil habitat and on water-cycling were considered. As a vital participant in the ecohydrological processes of soil-vegetation systems, the studies on biological soil crusts was also summarized, and related theoretical models of restoration based on the water balance was reviewed.XinRong Li 1,2, ZhiShan Zhang 1,2, Lei Huang 1,2, LiChao Liu 1,2, XinPing Wang 1,2 1. Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China. 2. Laboratory of Stress Ecophysiology and Biotechnology, Cold and Arid Regions Environmental and Engineering Research In-stitute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China. 2009Research in Cold and Arid Regions2009,1,3:4
20Important progress on the use of isotope techniques and methods in catchment hydrology显示文摘The use of isotope techniques and methods in catchment hydrology in the last 50 years has generated two major types of progress: (1) Assessment of the temporal variations of the major stocks and flows of water in catchments, from which the estimation of wa-ter residence times is introduced in this paper. (2) Assessment of catchment hydrologic processes, in which the interactions be-tween different waters, hydrographical separation, and bio-geochemical process are described by using isotopes tracers. Future progress on isotope techniques and methods in hydrology is toward the understanding of the hydrological process in large river basins. Much potential also waits realization in terms of how isotope information may be used to calibrate and test distributed rainfall-runoff models and regarding aid in the quantification of sustainable water resources management.JinKui Wu 1,2, YongJian Ding 1, BaiSheng Ye 1, QiYue Yang 3, Zhi Wei 1 1. Key Laboratory of Ecological Hydrology and Basin Sciences in Cold and Arid Regions Environmental and Engineering Re-search Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China. 2. Institute for Landscape Ecology and Resources Management, Justus-Liebig-University Giessen, Giessen 35392, Germany. 3. College of Earth and Environmental Science, Lanzhou University, Lanzhou, Gansu 730000, China. 2009Research in Cold and Arid Regions2009,1,3:4
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