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1Belowground carbon balance and carbon accumulation rate in the successional series of monsoon evergreen broad-leaved forest显示文摘The balance, accumulation rate and temporal dynamics of belowground carbon in the successional series of monsoon evergreen broadleaved forest are obtained in this paper, based on long-term observations to the soil organic matter, input and standing biomass of litter and coarse woody debris, and dissolved organic carbon carried in the hydrological process of subtropical climax forest ecosystem—monsoon evergreen broad-leaved forest, and its two successional forests of natural restoration—coniferous and broad-leaved mixed forest and Pinus massoniana forest, as well as data of root biomass obtained once every five years and respiration measurement of soil, litter and coarse woody debris respiration for 1 year. The major results include: the belowground carbon pools of monsoon evergreen broad-leaved forest, coniferous and broad-leaved mixed forest, and Pinus massoniana forest are 23191 ± 2538 g·m?2, 16889 ± 1936 g·m?2 and 12680 ± 1854 g·m?2, respec- tively, in 2002. Mean annual carbon accumulation rates of the three forest types during the 24a from 1978 to 2002 are 383 ± 97 g·m?2·a?1, 193 ± 85 g·m?2·a?1 and 213 ± 86 g·m?2·a?1, respectively. The belowground carbon pools in the three forest types keep increasing during the observation period, suggesting that belowground carbon pools are carbon sinks to the atmosphere. There are seasonal variations, namely, they are strong carbon sources from April to June, weak carbon sources from July to September; while they are strong carbon sinks from October to November, weak carbon sinks from December to March.ZHOU Guoyi1, ZHOU Cunyu1, LIU Shuguang2, TANG Xuli1, OUYANG Xuejun1, ZHANG Deqiang1, LIU Shizhong1, LIU Juxiu1, YAN Junhua1, ZHOU Chuanyan1, LUO Yan1, GUAN Lili1 & LIU Yan1 1. Dinghushan Forest Ecosystem Research Station, Chinese Academy of Sciences, Guangzhou 510650, China 2. SAIC, EROS Data Center, U.S. Geological Survey, Sioux Falls, SD 57198, USA 2006Science China Earth Sciences2006,49,3:36
2Effect of Cultivation on Spatial Distribution of Nematode Trophic Groups in Black Soil显示文摘Geostatistics combined with GIS was applied to assess the spatial distribution of nematode trophic groups following two contrasting soil uses in the black soil region of Northeast China. Two plots, one with fallow for 12 years and the other cultivated, were marked on regular square grids with 2-m spacing. Soil samples were collected from each sampling point, nematodes were extracted from these samples and classified into four trophic groups: bacterivores, fungivores, plant parasites, and omnivores/predators. The numbers of total nematodes and trophic groups analyzed had normal distributions on both fallow and cultivated plots. The absolute abundances of total nematodes and trophic groups were observed to be much more homogeneous on cultivated plot than on fallow one. Geostatistical analysis showed that the densities of total nematodes and trophic groups on both fallow and cultivated plots exhibited spatial dependence at the sampled scale and their experimental semivariograms were adjusted to a spherical or exponential model, except those of bacterivores and fungivores on cultivated plot. The spatial distribution of nematode trophic groups was found to be different for the two land uses, indicating that cultivation changed the native condition for soil nematode activities.LIANG WENJU, LI QI, JIANG YONG, CHEN WENBO and WEN DAZHONGShenyang Experimental Station of Ecology, Institute of Applied Ecology, the Chinese Academy of Sciences, Shenyang 110016 (China) 2003Pedosphere2003,13,2:29
3Estimate of Methane Emission from Rice Paddy Fieldsin Taihn Region, China显示文摘EstimateofMethaneEmissionfromRicePaddyFieldsinTaihnRegion,ChinaCAIZU-CONG;XUHUA;ZHANGHAN-HUI;andJINJI-SHENG(InstituteofSoilSc...CAI ZU-CONG XU HUA ZHANG HAN-HUI and JIN JI-SHENG(Institute of Soil Science, Chinese Academy of Sciences, P. O. Box 821, Nanjing 210008 ( China)Agricultural Extension Station of Wuxian County, Suzhou 215007 (China)) 1994Pedosphere1994,4,4:22
4Ecological response to the climate change on the northern slope of the Tianshan Mountains in Xinjiang显示文摘The Tianshan Mountains is a high and huge mountain body lying across the central part of Xinjiang, China, and is also the main area where the runoff forms in Xinjiang. In this paper, a set of RS-based study methods is put forward for deriving the information about the natural change of the ecology in arid areas, and the relationship between the climate change trend and the corresponding ecological response on the northern slope of the Tianshan Mountains since recent 40 years is analyzed from the scales of the land cover ecosystems and landscapes based on the observed data of climate, hydrology, modern glaciers and lakes on the northern slopes of the Tianshan Mountains since recent 40 years and the satellite RS data since recent 10 years by using the RS and GIS technologies. The results are as follows: (1) The overall trend of climate change on the northern slope of the Tianshan Mountains since recent 40 years is that both air temperature and precipitation are increased, especially the increase amplitudes of air tempera-ture, precipitation and annual runoff volume are high since the decade of the 1990s; (2) the in-tegrated indexes of the vegetation in all the geographical divisions on the northern slope of the Tianshan Mountains are obviously increased since recent 10 years, especially in the artificial oases and the foothill belts, such a change trend is advantageous for improving the vegetation ecology; and (3) the vegetation ecology in the arid areas is extremely sensitive to the climate change, the vegetation coverage and the biomass on the northern slope of the Tianshan Moun-tains are continuously increased because of the climate change since recent 10 years, their in-crease amplitudes in the plains and during the late stage are obviously higher than that in the mountainous regions and during the early stage.CHEN Xi1, LUO Geping1, XIA Jun2, ZHOU Kefa1, LOU Shaoping3 & YE Minquan4 1. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China 2. Institute of Geographical and Resources Sciences, Chinese Academy of Sciences, Beijing 100101, China 3. Urumqi Meteorological-satellite Land Station, Urumqi 830011, China 4. Seismological Bureau of Xinjiang Uygur Autonomous Region, Urümqi 830011, China Correspondence should be addressed to Chen Xi 2005Science China Earth Sciences2005,48,6:19
5Changes in individual plant traits and biomass allocation in alpine meadow with elevation variation on the Qinghai-Tibetan Plateau显示文摘Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes,plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts,especially storage organs,as altitude increases,so as to geminate and resist environmental stress.However,results indicate that some divergence in biomass allocation exists among organs.With increasing altitude,the mean fractions of total biomass allocated to aboveground parts decreased.The mean fractions of total biomass allocation to storage organs at the subalpine site (7%±2% S.E.) were distinct from those at the alpine (23%±6%) and subnival (21%±6%) sites,while the proportions of green leaves at all altitudes remained almost constant.At 4300 m and 5000 m,the mean fractions of flower stems decreased by 45% and 41%,respectively,while fine roots increased by 86% and 102%,respectively.Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation,while sedges showed opposite trends.For all three functional groups,leaf area ratio and leaf area root mass ratio decreased,while fine root biomass increased at higher altitudes.Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots,while the proportion of leaves remained stable.It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots.In contrast to forbs and grasses that had high mycorrhizal infection,sedges had higher single leaf area and more root fraction,especially fine roots.MA WeiLing1,2,SHI PeiLi1*,LI WenHua1,HE YongTao1,ZHANG XianZhou1,SHEN ZhenXi1 & CHAI SiYue1,2 1Lhasa National Ecological Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 2Graduate University of Chinese Academy of Sciences,Beijing 100049,China 2010Science China(Life Sciences)2010,53,9:19
6Elemental composition of aerosols collected in the glacier area on Nyainqêntanglha Range, Tibetan Plateau, during summer monsoon season显示文摘In order to investigate the elemental composition in atmospheric aerosols and its sources in the glacier area over the Tibetan Plateau (TP), seven totally suspended particle samples were collected continuously at the col of the Zhadang glacier (30°28′N,90°39′E,5800 m a.s.l.), Nyainqêntanglha Range, southern TP, from June to October 2006. Twenty-seven elements (Li, Be, B, Na, Mg, Al, K, Ca, Sc, Ti, V, Fe, Mn, Zn, Ga, As, Rb, Sr, Y, Cd, Cs, Ba, Tl, Pb, Bi, Th, U) were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The result indicates that the concentrations of most elements (especially crustal elements) are lower than values at the Nam Co Station during the same period of 2005, and also much lower than other sites in the TP such as Wudaoliang and Waliguan. This suggests that elemental compositions of aerosols in the Zhadang glacier area may represent the background levels of the middle/upper troposphere over the TP. Crustal enrichment factors (EFs) reveal that several elements (e.g. B, Zn, As, Cd, Pb and Bi) may have anthropogenic sources. The southern TP is mainly influenced by the summer Indian monsoon during the sampling period. Backward air mass trajectory analysis suggests that air masses in the region may originate from South Asia. Therefore, anthropogenic pollutants from South Asia may be transported by the summer Indian monsoon to the region which clearly affects the atmospheric environment in the southern TP during the summer monsoon season.LI ChaoLiu1,2, KANG ShiChang1,3 & CONG ZhiYuan1,2 1 Nam Co Monitoring and Research Station for Multisphere Interactions, Institute of Tibetan Plateau Research, CAS, Beijing 100085, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100039, China 3 State Key Laboratory of Cryospheric Sciences, CAS, Lanzhou 730000, China 2007Chinese Science Bulletin2007,52,24:18
7Canopy and leaf gas exchange of Haloxylon ammodendron under different soil moisture regimes显示文摘In order to reveal the drought resistance and adaptation of the C4 desert plant Haloxylon ammodendron under artificially controlled soil moisture regimes,representative plants were selected to measure canopy photosynthesis using canopy photosynthetic measurement system.The results showed that appropriate soil moisture significantly enhances the canopy and leaf photosynthetic capacity,and extremely high soil moisture is not conducive to the photosynthesis of H.ammodendron.GAO Song,SU PeiXi,YAN QiaoDi & DING SongShuang Linze Inland River Basin Research Station,Plant Stress Ecophysiology and Biotechnology Laboratory,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China 2010Science China(Life Sciences)2010,53,6:15
8Permafrost on the Qinghai-tibet Plateau under a Changing Climate显示文摘Permafrost on the Qinghai-Tibet Plateau (QTP) has experienced major shifts during theQuaternary. During the past 40 years, permafrost has been degrading extensively, due to climaticwarming. Simulations suggest significant degradation of permafrost both in extent and inthickness within the next 50-100 years. Freshwater wetlands on the QTP can contributesignificantly to the global budgets in the atmospheric greenhouse gases. Permafrost degradationon the QTP has caused destabilization of foundations of engineering structures, deterioration ofgrasslands and meadows, and weakening of permafrost control on water resources.JIN Huijun CHENG Guodong LI Xin LI Shuxun Observatory and Research Station of the Qinghai-Tibet Plateau. State Key Laboratory of Frozen Soil Engineering, LIGG, CAS, Lanzhou 730000 CHINA. 1999Chinese Science Bulletin1999,44,S1:14
9Temperature 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
10Spatial heterogeneity of DTPA-extractable zinc in cultivated soils induced by city pollution and land use显示文摘The spatial heterogeneity of DTPA-extractable zinc in the cultivated soils of Shenyang suburbs in Liaoning Province of China was investigated, and its map was drawn by the methods of geostatistics combined with geographic information system. The data of soil DTPA-extractable zinc fitted normal distribution after logarithm transformation, and its semivariogram fitted a spherical model. The semivariogram indicated that the spatial dependence of soil DTPA-extractable zinc content was moderate, with the spatial dependence range of 1.69 km and the fractal dimension of 1.96. Stochastic factors contributed to 49.9% of the spatial variability, while structural factors contributed to 50.1% of it. The spatial heterogeneity of soil DTPA-extractable zinc shown by a kriged interpolation map was deeply influenced by stochastic factors such as city pollution, land use pattern and crop distributions. For example, the average content of Zn in vegetable garden soils was 2.5-4 times as much as in their originated soils, and was lower in paddy soils than in their originated soils. The areas with a higher content of soil DTPA-extractable zinc appeared in the near suburbs and the riverside along Hunhe River and the wastewater drainage of Xihe River, and the extremely high values in the near suburb of the city's residential area were a striking feature, indicating the key role of city pollution in the spatial heterogeneity of soil DTPA-extractable zinc. When recorded in the form of a soil pollution map,the results of such a survey make it possible to identify the unusually polluted areas, and to provide more information for precise agriculture and environmental control.JIANG Yong, LIANG Wenju, WEN Dazhong, ZHANG Yuge & CHEN Wenbo Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, Shenyang 110016, China College of Land and Environment, Shenyang Agricultural University, Shenyang 110161, China 2005Science China(Life Sciences)2005,48,z1:13
11Characterizing and estimating rice brown spot disease severity using stepwise regression,principal component regression and partial least-square regression显示文摘Detecting plant health conditions plays a key role in farm pest management and crop protection. In this study, measurement of hyperspectral leaf reflectance in rice crop (Oryzasativa L.) was conducted on groups of healthy and infected leaves by the fungus Bipolaris oryzae (Helminthosporium oryzae Breda. de Hann) through the wavelength range from 350 to 2 500 nm. The percentage of leaf surface lesions was estimated and defined as the disease severity. Statistical methods like multiple stepwise regression, principal component analysis and partial least-square regression were utilized to calculate and estimate the disease severity of rice brown spot at the leaf level. Our results revealed that multiple stepwise linear regressions could efficiently estimate disease severity with three wavebands in seven steps. The root mean square errors (RMSEs) for training (n=210) and testing (n=53) dataset were 6.5% and 5.8%, respectively. Principal component analysis showed that the first principal component could explain approximately 80% of the variance of the original hyperspectral reflectance. The regression model with the first two principal components predicted a disease severity with RMSEs of 16.3% and 13.9% for the training and testing dataset, respec-tively. Partial least-square regression with seven extracted factors could most effectively predict disease severity compared with other statistical methods with RMSEs of 4.1% and 2.0% for the training and testing dataset, respectively. Our research demon-strates that it is feasible to estimate the disease severity of rice brown spot using hyperspectral reflectance data at the leaf level.LIU Zhan-yu1, HUANG Jing-feng1, SHI Jing-jing1, TAO Rong-xiang2, ZHOU Wan3, ZHANG Li-li3 (1Institute of Agriculture Remote Sensing and Information System Application, Zhejiang University, Hangzhou 310029, China) (2Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China) (3Plant Inspection Station of Hangzhou City, Hangzhou 310020, China) 2007Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2007,8,10:13
12Susceptibility to hepatocellular carcinoma associated with null genotypes of GSTM] and GSTT1显示文摘AIM In order to study the association betweenthe null genotypes of GSTM1 and GSTT1 and thegenetic susceptibility to hepatocellularcarcinoma(HCC).METHODS The genotypes of GSTM1 and GSTT1of 63 cases of HCC and 88 controls were detectedwith the multiple PCR technique.RESULTS The frequency of GSTM1 nullgenotype was 57.1% among the cases,and42.0% among the controls,the difference beingstatistically significant(χ~2=3.35,P=0.067),but χ~2 value approaching the significance level.The odds ratio was 1.84(95% Cl= 0.91-3.37).The frequency of GSTT1 non-null genotype was87.3% among the cases and 52.5% among thecontrols,the difference being statisticallysignificant(χ~2=11.42,P=0.0007274).The oddsratio was 4.13(95% Cl=1.64-10.70).According to the cross analysis,the GSTT1 non-null genotype was more closely associated withHCC than GSTM1 null genotype,and these twofactors play an approximate additive interactionin the occurrence of HCC.CONCLUSION The persons with GSTM1 nullgenotype and GSTT1 non-null genotype have theincreased risk to HCC.Jian Chao Bian Fu Min Shen Li Shen Tian Ru Wang Xiao Hong Wang Gong Chao Chen Jin Bing Wang Department of Epidemiology,Shanghai Medical University,Shanghai 200032,China Haimen Municipal Anti-Epidemic and Health Station,Haimen 226201,Jiangsu Province,China Qidong Institute for Liver Cancer,Qidong 226200,Jiangsu Province,China 2000World Journal of Gastroenterology2000,6,2:12
13Environmental Implications of Excessive Selenium: A Review显示文摘Selenium is a naturally occurring trace element that is nutritionally required in smallamounts but it can become toxic at concentrations only twice those required. The narrow mar-gin between beneficial and harmful levels has important implications for human activities thatincrease the amount of selenium in the environment. Two of these activities, disposal of fbssilfuel wastes and agricultural irrigation of arid, seleniferous soils, have poisoned fish andwildlife, and threatened public health at several locations in the United States. Research stud-ies of these episodes have generated a data base that clearly illustrates the environmental hazardof excessive selenium. It is strongly bioaccumulated by aquatic organisms and even slight in-creases in waterborne concentrations can quickly result in toxic effects such as deformed em-bryos and reproductive failure in wildlife. The selenium data base has been very beneficial indeveloping hazard assessment procedures and establishing environmentally sound water qualitycriteria. The two faces of selenium, required nutrient and Potent toxin, make it a particularlyimportant trace element in the health of both animals and man. Because of this paradox, envi-ronmental selenium in relation to agriculture, fisheries, and wildlife wiIl continue to raise im-POrtant land and water management issues for decades to come. If these issues are dealt withusing prudence and the available environmental selenium data base, adverse irnpacts to naturalresources andspublic health can beA. DENNIS LEMLY(United States Forest Service, Southern Research Station, Coldwater Fisheries Research Unit, Department of Fisheries and Wildlife Sciences, Virginia Tech University, Blacksburg, VA 24061-0321, USA) 1997Biomedical and Environmental Sciences1997,10,4:10
14Rainfall 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
15Stiffness requirement of flexible skin for variable trailing-edge camber wing显示文摘The method for analyzing the deformation of flexible skin under the air loads was developed based on the panel method and finite element method.The deformation of flexible skin under air pressures and effects of the local deformation on the aerodynamic characteristics were discussed.Numerical results show that the flexible skin on the upper surface of trailing-edge will bubble under the air loads and the bubble has a powerful effect on the aerodynamic pressure near the surface of local deforma-tion.Then the stiffness requirements for flexible skin of variable trailing-edge were given by using the Jacobs rule,i.e.,the maximum displacement of skin is not greater than 0.1% of wing chord.Results show that the in-plane stiffness can be reduced by increasing the ratio of bending stiffness to in-plane stiffness.Although the deformation of flexible skin increases with the in-plane stiffness decreasing,it depends on the bending stiffness.When the bending stiffness exceeds critical value,the deformation of flexible skin only depends on the bending stiffness and has nothing to do with the in-plane stiffness.The conclusions can be used for the structural design of flexible skin.YIN WeiLong Center for Composite Materials and Structures and Postdoctoral Station of Mechanics,Harbin Institute of Technology,Harbin 150080,China 2010Science China(Technological Sciences)2010,53,4:9
16The role of MC1R gene in buffalo coat color显示文摘Melanocortin-1 receptor (MC1R) plays a major role in pigmentation in many species.To investigate if the MC1R gene is associated with coat color in water buffalo,the coding region of MC1R gene of 216 buffalo samples was sequenced,which included 49 black river buffalo (Murrah and Nili-Ravi),136 swamp buffalo (Dehong,Diandongnan,Dechang,Guizhou,and Xilin) with white and gray body,and 31 hybrid offspring of river buffalo Nili-Ravi (or Murrah) and swamp buffalo.Among the three variation sites found,SNP684 was synonymous,while SNP310 and SNP384 were nonsynonymous,leading to p.S104G and p.I128M changes,respectively.Only Individuals carrying homozygote EBR/EBR were black.The genotype and phenotype analysis of the hybrid offspring of black river buffalo and gray swamp buffalo further revealed that the river buffalo type allele EBR or the allele carrying the amino acid p.104S was important for the full function of MC1R.The in silico functional analysis showed that the amino acid substitutions p.G104S and p.M128I had significant impact on the function of MC1R.Above results indicate that the allele EBR or the allele carrying the amino acid p.104S was associated with the black coat color in buffalo.MIAO YongWang1,2,WU GuiSheng3,WANG Lei2,LI DaLin4,TANG ShouKun5,LIANG JianPing2,MAO HuaMing2,LUO HuaiRong3 & ZHANG YaPing1,6 1 Laboratory for Conservation and Utilization of Bio-resource,Yunnan University,Kunming 650091,China 2 Faculty of Animal Science and Technology,Yunnan Agricultural University,Kunming 650201,China 3 Kunming Institute of Botany,Chinese Academy of Sciences,Kunming 650204,China 4 Yunnan Institute of Buffalo Science and Technology,Kunming 650021,China 5 Animal Husbandry and Veterinary Station of Luxi city,Luxi 678400,China 6 State Key Laboratory of Genetic Resources and Evolution,Kunming Institute of Zoology,Chinese Academy of Sciences,Kunming 650223,China 2010Science China(Life Sciences)2010,53,2:8
17A NEW QUANTITATIVE WAY FOR DETERMINING LEAF AREA INDEXAND NET PRIMARY PRODUCTIVITY IN REGIONAL SCALE显示文摘An inversion of bidirectional reflection distribution fiJnedon (BRDF) wastested using NK Model and NOAA AVHRR datu. The test involVed sensitiveanalysis, optimum inversion selecting, ground simulated expenment, calibrahngmeasuremed with satellite and computer image processmg. Results of comparisonwith NDVI indicatal that inversion of BRDF will have brigh developing prospect inthe next decade.Zhang Renhua(Institute of Geography, CAS, Bejing 100101, P.R. China)Andres Kuusk(Estorua Observatory, Tatu, Estorua)Chen Gang(Ground Station of Satellite Remote Sensing, CAS, Behing 100086, P.R. China)Alan Strahler Li Xiaonen(Remote Sensing Cater, Boston 1996Journal of Geographical Sciences1996,6,4:7
181998~1999年国外塑料工业进展显示文摘收集了 1998年 7月到 1999年 6月国外塑料工业相关期刊资料 ,介绍了 1998~ 1999年国外塑料工业进展。提供了日本、美国、加拿大、德国、法国、比利时、意大利、英国、西班牙、匈牙利、马来西亚等国通用热塑性树脂、工程塑料、通用热固性树脂、特种工程塑料的产量和增长率 ,提供了美国、日本、德国、韩国、法国、比利时、荷兰、意大利和其他国家以及亚洲、欧洲、北美洲、中南美洲、非洲和大洋洲等地域的树脂产量及构成比 ,此外还提供了中国台湾的树脂产量。按通用热塑性塑料、通用热固性塑料、通用工程塑料和特种工程塑料分类 ,对其合成工艺、树脂品种延伸。WT5BZ]National General Information Station of Synthetic Resin and Plastics Industry CHINA PLASTICS INDUSTRY Editorial Office 2000塑料工业2000,28,3:7
19Recent Advances in Swine Amino Acid Nutrition显示文摘Recent advances in swine protein nutrition are characterized by the development of functional amino acids(AA)in regulating fetal and postnatal survival,growth and development.These AA include arginine,glutamine,glutamate,proline,leucine,cysteine and tryptophan.Due to limited knowledge on AA nutrition,pork producers have traditionally paid little attention to supplementing the arginine family of AA to swine diets.Results of recent studies indicate that functional AA serve important regulatory functions in nutrient metabolism,protein turnover,and immune function,therefore enhancing efficiency of feed utilization by pigs.The underlying mechanisms include activation of nitric oxide,mammalian target of rapamycin,gaseous signaling,and AMP-activated protein kinase pathways,as well as anti-oxidative function.Dietary supplementation with arginine,glutamine,proline or leucine to weanling piglets enhances their growth performance.Arginine or glutamine is also effective in increasing milk production by lactating sows.Furthermore,supplementing arginine to the diet of pregnant gilts between days 30 and 114 of gestation increases the number of live-born piglets and litter birth-weight.Availability of feed-grade functional AA holds great promise for improving animal health and nutrient utilization in pig production worldwide.Additionally,feedstuffs of animal origin [e.g.,blood meal(ring dried),feather meal(hydrolyzed),meat and bone meal,porcine protein meal,and poultry by-product meal(both feed-and petfood-grades)] are excellent and cost-effective sources of both essential and functional AA for formulating balanced swine diets.New knowledge on AA nutrition provides a much needed scientific basis for revising the next edition of swine nutrient requirements.Guoyao Wu Department of Animal Science and Faculty of Nutrition,Texas A&M University,College Station,TX,77843,U.S.A and State Key Laboratory of Animal Nutrition,China Agricultural University,Beijing,100193,China 2010Journal of Animal Science and Biotechnology2010,1,2:7
20Stochastic modelling of soil moisture dynamics in a grassland of Qilian Mountain at point scale显示文摘Stochastic modeling of soil moisture dynamics is crucial to the quantitative understanding of plant responses to water stresses,hydrological control of nutrient cycling processes,water competition among plants,and some other ecological dynamics,and thus has become a hotspot in ecohydrology at present.In this paper,we based on the continuously monitored data of soil moisture during 2002―2005 and daily precipitation date of 1992―2006,and tried to make a probabilistic analysis of soil moisture dynamics at point scale in a grassland of Qilian Mountain by integrating the stochastic model improved by Laio and the Monte Carlo method.The results show that the inter-annual variations for the soil moisture patterns at different depths are very significant,and that the coefficient of variance(CV) of surface soil moisture(20 cm) is almost continually kept at about 0.23 whether in the rich or poor rainy years.Interestingly,it has been found that the maximal CV of soil moisture has not always appeared at the surface layer.Comparison of the analytically derived soil moisture probability density function(PDF) with the statistical distribution of the observed soil moisture data suggests that the stochastic model can reasonably describe and predict the soil moisture dynamics of the grassland in Qilian Mountain at point scale.By extracting the statistical information of the historical precipitation data in 1994―2006,and inputting them into the stochastic model,we analytically derived the long-term soil moisture PDF without considering the inter-annual climate fluctuations,and then numerically derived the one when considering the inter-annual fluctuation effects in combination with a Monte-Carlo procedure.It was found that,though the peak position of the probability density distribution significantly moved towards drought when considering the disturbance forces,and its width was narrowed,accordingly its peak value was increased,no significant bimodality was observed in the soil moisture dynamics under the given intensity of random fluctuation disturbance.LIU Hu,ZHAO WenZhi HE ZhiBin & ZHANG LiJie Linze Inland River Basin Research Station,Chinese Ecosystem Research Network Laboratory of Watershed Hydrology and Ecol-ogy,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China 2007Science China Earth Sciences2007,50,12:7
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