Spectral models for solar-scaled and α-enhanced stellar populations     

P. Coelho  G. Bruzual  S. Charlot  A. Weiss  B. Barbuy  J. W. Ferguson 《Monthly notices of the Royal Astronomical Society》2007,382(2):498-514

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Spatial and temporal dynamics of soil moisture after rainfall events along a slope in Regosols of southwest China     

Gangcai Liu  Jianhui Zhang 《水文研究》2007,21(20):2778-2784

High frequency seasonal drought in purple soils (Regosols in FAO taxonomy) of the hilly upland areas of Sichuan basin, China, is one of the key restrictive factors for crop production. In order to manage irrigation and fertilizer application in these soils effectively, the soil water content in a sloped plot with 60 cm soil depth was measured by neutron probe devices to investigate the soil moisture regime during the 1998 rainy season after various amounts of rainfall events. The results showed that variation of soil moisture along the slope positions was highest in the top soil layer during the period of sporadic rainfall that did not induce any runoff. The coefficients of variation of soil moisture at various slope positions (upper, middle, and lower) are 17·36%, 8·95%, 10·25%, 8·58%, 8·05% and 9·21% at the 10 cm, 20 cm, 30 cm, 40 cm, 50 cm and 60 cm soil depths respectively. When surface runoff occurred, the soil moisture dynamics at various positions on the plot were then very different. Soil water content decreased more rapidly on the upper slope than on the middle and lower slope positions. When both surface runoff and throughflow occurred, the soil moisture dynamics in the various layers showed a stable period (soil water content is near constant as time elapses) that lasted about 1 week. Also, the pattern of moisture dynamics is ‘decreasing–stabilization–decreasing’. Thus, irrigation and fertilization management according to the spatial and temporal features of soil moisture dynamics on sloped land can increase the water and fertilizer utilization efficacy by reducing their losses during the stable period. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

The metallicity distributions in high-latitudes with SDSS     

S. Ak  S. Bilir  S. Karaali  R. Buser  A. Cabrera-Lavers   《New Astronomy》2007,12(8):605-612

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Analysis of the water content in an unconfined aquifer with a partially penetrated pumping well     

Jiann‐Mou Chen 《水文研究》2008,22(26):5037-5047

Most methods developed to represent water flow phenomena in an unconfined aquifer with a fully penetrated pumping well are either numerical, such as the well‐known FEMWTER model, or experimental; analytical models of a partially penetrated pumping well are rare. This study employs the linearized Richards equation as the governing equation, with the aid of Fourier Integral Transformation, to obtain an analytical solution of the water content distribution in an unconfined aquifer with a partially penetrated pumping well. The results from this study could serve to substantiate in some sense results from numerical models. In addition, the theory developed herein can be modified to simulate a vacuum‐pressured pumping well since it is derived by considering, among others, the location and length of a well screen with fluxes. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

光子晶体光纤中零色散点处超连续谱演变的研究     

王晶  刘树燕  时延梅 《中国海洋大学学报(自然科学版)》2008,38(6)

从非线性薛定谔方程出发,采用分步傅立叶分析方法数值模拟光子晶体光纤中超连续谱的产生,计算、模拟并分析初始啁啾在光子晶体光纤的零色散点对超连续谱演变和带宽的影响.结果表明,非线性作用使频谱分裂成多峰不对称的结构,初始啁啾C的引入能明显的改善超连续谱的带宽和平坦性.由于二阶色散β2=0,三阶色散猹对超连续光谱的展宽影响较大.当β3>0时,C取正值时,随着C的增大,带宽减小; C取负值时,带宽有所增大,平坦性也有改善;β3<0时,无论C取正取负,频谱带宽增大,且平坦性较好.  相似文献   

On the interpretation of the age and chemical composition of composite stellar populations determined with line-strength indices   总被引：1，自引：0，他引：1  

P. Serra  S. C. Trager 《Monthly notices of the Royal Astronomical Society》2007,374(3):769-774

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闽南近海中国团扇鳐和林氏团扇鳐肌肉中水分含量、灰分含量及能值的分析   总被引：1，自引：0，他引：1  

杜建国  陈明茹  杨圣云 《台湾海峡》2009,28(4):509-515

测定了中国团扇鳐和林氏团扇鳐肌肉中的水分含量、灰分含量及能值．中国团扇鳐肌肉水分含量为75．86％，灰分含量为5．15％，能值为21．49MJ/kg；林氏团扇鳐肌肉水分含量为76．66％，灰分含量为5．04％，能值为21．29MJ／kg．中国团扇鳐、林氏团扇鳐的体重与体长有显著的正相关关系；中国团扇鳐、林氏团扇鳐的水分含量随体重的增加而减小，能值随体重的增加而升高；中国团扇鳐肌肉的能值与水分含量之间具有一定的相关递减的趋势，林氏团扇鳐水分含量与灰分含量之间具有一定的相关递增的趋势．此外，中国团扇鳐、林氏团扇水分含量、灰分含量及能值随季节的变化而变化．这与鱼体自身的生物学特性有关。也受到环境因子变化的影响．  相似文献   

Broad-band colours and overall photometric properties of template galaxy models from stellar population synthesis     

Alberto Buzzoni 《Monthly notices of the Royal Astronomical Society》2005,361(2):725-742

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Near-infrared imaging of 222 nearby Hδ-strong galaxies from the Sloan Digital Sky Survey     

Michael L. Balogh  Chris Miller  Robert Nichol  Ann Zabludoff  Tomo Goto 《Monthly notices of the Royal Astronomical Society》2005,360(2):587-609

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Application of a coil‐type TDR probe for measuring the volumetric water content in weathered granitic bedrock     

Shin'ya Katsura  Ken'ichirou Kosugi  Takahisa Mizuyama 《水文研究》2008,22(6):750-763

As a first step toward describing water flow processes in bedrock, a coil‐type time domain reflectometry (TDR) probe capable of measuring volumetric water content, θ, in weathered bedrock at three depths was prepared. Because the coil‐type TDR probe is large in diameter (19 mm), it can be installed even in highly weathered bedrock more easily and appropriately than conventional TDR probes that consists of two or three rods of small diameter (5‐8 mm). The probe calibrations suggest that the values measured by the probe are very sensitive to changes in θ. Using the calibrated probe together with commercially available profile soil moisture sensors, the θ profile was monitored for 1 year. Even rainfall events with relatively small cumulative rainfall of 15 mm increased the bedrock θ, and the increments were comparable to those in the soil. After the end of the rainfall events, the bedrock θ displayed a more rapid drop than the soil, and varied little during the period of no rainfall. The water storage showed similar tendencies. These observations suggest that the bedrock θ is controlled by clearly distinguishable macropores and micropores within the bedrock. It is concluded that the coil‐type TDR probe is very effective in determining θ in weathered bedrock, and that bedrock, conventionally defined by conducting cone penetration tests and treated as impermeable, does conduct and hold substantial amounts of water, and therefore contribute greatly to hydrological processes in headwater catchments. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献