卫星遥感估测土壤水分的一种方法   总被引：46，自引：1，他引：46  

刘培君  张琳  艾里西尔·库尔班  常萍  李良序  镨拉提  赵兵科 《遥感学报》1997,1(2):135-138,81

对于植被影响土壤水分遥感的大小 ,提出了“光学植被盖度”新概念来衡量 ,并用遥感法进行估测。用分解象元法排除植被干扰来提取土壤水分光谱信息。采用土壤水分光谱法并借助回归分析建立土壤水分遥感的TM数据模型。以此为桥梁 ,建立了AVHRR数据模型  相似文献   

Partitioning of boron among melt, brine and vapor in the system haplogranite–H₂O–NaCl at 800 °C and 100 MPa     

Oliver J. Schatz  David Dolej  John Stix  Anthony E. Williams-Jones  Graham D. Layne 《Chemical Geology》2004,210(1-4):135-147

Fluid-saturated experiments were conducted to investigate the partitioning of boron among haplogranitic melt, aqueous vapor and brine at 800 °C and 100 MPa. Experiments were carried out in cold-seal pressure vessels for 1 to 21 days, and utilized powdered synthetic subaluminous haplogranite glass doped with 1000 ppm B (crystalline H₃BO₃) and variable amounts of NaCl and H₂O at a fluid/haplogranite mass RATIO=1:1. Run-product glasses were analyzed for boron concentration by secondary ion mass spectrometry (SIMS) and for major elements and chlorine by electron microprobe. The composition of the coexisting fluid was calculated by mass balance. Boron partition coefficients between aqueous vapor and hydrous granitic melt range from 3.1 to 6.3, and demonstrate a clear preference of boron for the vapor over the hydrous melt. Partition coefficients between brine and hydrous granitic melt vary from 0.45 to 1.1, suggesting that boron has no preference for the brine or the melt. The bulk fluid–melt partition coefficients for low-salinity and high-salinity experiments are D_B^(vapor/melt)=4.6±1.3 and D_B^(brine/melt)=0.91±0.49, respectively. The corresponding vapor–brine partition coefficient is 5.0±3.1, demonstrating that boron partitions preferentially into the vapor over the brine at the conditions of this study. The preferential incorporation of boron in the aqueous vapor is controlled by borate speciation and solution mechanism. The dominant borate species in aqueous fluids, H₃BO₃^o, is highly soluble in aqueous vapor (X_B2O3=0.187); however, B₂O₃ is immiscible in NaCl liquid. Consequently, concentrations of boron in aqueous vapor are significantly higher than in the coexisting brine. Furthermore, Na–B complexing in the melt at high chlorine fluid contents stabilizes boron in the melt thereby contributing to the non-preferential partitioning of boron between brine and melt. The commonly observed association of tourmalinization (boron metasomatism), brecciation and ore deposition in nature is consistent with the preferential partitioning of boron into aqueous vapor of magmatic-hydrothermal systems predicted by this study.  相似文献   

不同硼水平与光照条件的交互作用对春小麦生长发育和结实的影响     

孙东旭  孙彦坤  刘春生  严红  朱洪麟  江洪飞 《黑龙江气象》2003,(1):19-20

用溶液培养法对硼和光照与小麦生长发育及结实率的关系进行了试验研究。结果表明：缺硼小麦株高和干物重下降；光照减弱，小麦干物质和株高明显降低。相反较高硼的供给可以增强小麦的抗逆性。缺硼严重影响小麦结实率，甚至导致小麦不结实；在相同供硼水平下，小麦硼积累量随光照减弱而降低。  相似文献   

找矿信息量法在铜山铜矿成矿预测中的应用   总被引：4，自引：0，他引：4  

王勇  陈邦国 《地质与勘探》2002,38(3):49-51

在分析铜山矿田控矿条件，总结成矿规律的基础上，利用找矿信息量法对矿田进行综合成矿预测，提出了预测靶区。  相似文献   

河南省飞机人工增雨试验效果检验   总被引：1，自引：0，他引：1  

冶林茂  胡鹏等 《河南气象》2002,(1):33-34

采用区域对比的试验方法，选取1991年至1998年春、秋季试验作业区和对比区内测站逐时历史降水资料，对历史增雨作业效果进行了评估。统计检验结果表明，河南省1991年至1998年春、秋季人工增雨效果分别为20．05％、13．22％，总平均效果为16．63％。  相似文献   

西部含锂、钾、镁、硼盐卤资源水盐体系相化学研究   总被引：4，自引：0，他引：4       下载免费PDF全文

张逢星  李君  魏小兰  杨琴  郭志箴  陈运生 《盐湖研究》2002,10(3):20-25

从资源特点出发 ,分别回顾了含锂、钾、镁氯化物多元水盐体系 ,镁水泥体系 ,盐卤锂、钾卤化物水盐体系的相化学研究 ,概括了主要研究成果并指出实际应用上的关键问题 ,以及研究的主要内容。  相似文献   

两种区域电离层拟合模型比较研究     

范叹奇  施闯  刘科  章红平  刘根 《测绘信息与工程》2008,33(6):8-9

建立了单基准站和多基准站的三角级数模型和多项式模型,设计了利用邻近站数据进行两种模型内外符合精度检验的方法,分析了两种模型在精度方面的差异。  相似文献   

Diet of Littoraria scabra, while vertically migrating on mangrove trees: Gut content, fatty acid, and stable isotope analyses   总被引：1，自引：1，他引：0  

Andrea C. Alfaro   《Estuarine, Coastal and Shelf Science》2008,79(4):718-726

The snail, Littoraria scabra, is a dominant grazer on tropical mangrove trees, and may play an important role in the food web dynamics of these ecosystems. Its daily vertical migration to avoid tidal submersion results in exposure to varying food types and abundances. A comprehensive diet analysis – gut contents, fatty acid profiles, and stable isotopes (δ¹⁵N and δ¹³C) – was conducted on snails migrating along mangrove trees and snails maintained in non-tidal mesocosms at Nananu-i-ra, Fiji Islands. In addition, fatty acid profiles and stable isotope signatures were obtained from surface scrapings of mangrove roots, trunks, branches, and leaves. Results from this multi-technique study indicate that L. scabra is mainly a generalist herbivore, which easily shifts diets depending on food availability, and which also has the ability to ingest and assimilate zooplankton. Ingestion of greater quantities of diverse foods (i.e., microalgae, foliose/corticated macrophytes, filamentous algae, mangrove tissues, zooplankton) takes place in the bottom areas of mangrove trees (roots and trunks) during low tides, while top areas (branches and leaves) provide limited food resources for snails feeding during high tides. However, snails preferentially assimilate microalgae and bacteria, regardless of their feeding habitat (different areas within mangrove trees and non-tidal mesocosms). The daily vertical movements of this snail result in variable feeding times, ingestion of different food types and amounts, and different assimilations. These findings also suggest that organic matter derived from mangrove tissues may not be readily transferred to higher trophic levels through this grazing pathway.  相似文献   

科尔沁沙地退化植被恢复过程中碳氮化学计量特征的变化          下载免费PDF全文

吕朋  左小安  孙珊珊  张晶  赵生龙  程清平  胡亚 《干旱区地理》2019,42(3):606-614

为研究沙地退化植被恢复过程中碳氮化学计量特征的变化，分别于2011年、2013年和2015年8月中旬对流动、半固定、固定沙丘和草地进行植被调查，并测定植被—土壤系统的碳氮化学计量特征。结果表明：（1） 随着沙地退化植被的恢复，地上植物、凋落物和根系的C、N含量及C/N比波动变化，土壤（0～10 cm）C和N含量及C/N比显著增加（P <0.05）。（2）沙地4种生境上的地上植物、凋落物、根系、土壤的C、N含量及C/N比年际间变化显著（P <0.05）。（3） 沙地退化植被恢复过程中地上植物、凋落物、土壤的C/N比与物种丰富度呈正线性关系（P <0.01）。沙地退化植被恢复过程中优势植物演替导致植被—土壤系统中C、N化学计量特征的变化，植被恢复过程中植物的氮素利用效率也在逐渐增强，而封育时间的增加能够促进沙地土壤中N的积累。  相似文献   

Hydrochemical characteristics of Lastochka Spa (Primorye, Far East of Russia)     

N.A. Tchepkaia  G.A. Chelnokov  A.A. Karabtsov  I.A. Tarasenko 《Journal of Geochemical Exploration》2006,88(1-3):148

This study presents new data on major, trace and REE element concentration of groundwaters in Lastochka spa located in the northern part of Primorye, Far East of Russia. The studied area is characterized by two types of groundwaters issued from a spring and wells: fresh waters with low mineralization (Total Dissolved Solids is up to 400 mg/l) and high pCO₂ waters with high mineralization (TDS is up to 4700 mg/l). New data and previous δ¹³C_(TIC), oxygen (δ¹⁸O) and hydrogen (δ²H) isotope data indicate that these waters result from meteoric water infiltration in the Sikhote–Alin mountain, circulating at shallow depths in sedimentary rocks. CO₂ in groundwater is of mantle origin.  相似文献