Daily variation of carbon flux in soils of Populus euphratica forests in the middle and lower reaches of the Tarim River

In order to lucubrate the daily variation of respiration in soils of Populus euphratica forests and analyze its relationship with environmental factors in the middle and lower reaches of the Tarim River, the LI-8100 instrument of soil CO2 flux system was used to measure the parameters of soil carbon flux and air temperature 10 cm above ground surface along the profiles of Usyman, Archy River, Yengisu and Karday, and the relationships between the soil carbon flux and the soil moisture content were analyzed. The nonlinear regression analysis was carried out with the software SPSS13.0. We observed that: (1) soil respiration began to be restrained when the air temperature was up to 30℃10 cm above the ground surface; (2) the rates of soil respiration under the forests of Populus euphratica were significantly different at various moisture contents, the soil carbon flux was high along the Usyman profile, which has a high soil moisture content, and it was low along the profiles of Archy River, Yengisu and Karday, which has a low soil moisture content; (3) the exponential model can be used to explain the relationship between soil respiration and air temperature 10 cm above the ground surface. The average Q10 values along the profiles of Usyman, Archy River, Yengisu and Karday are 0. 61, 0.16, 0. 22 and 0. 35 respectively, much lower than the average of the world; (4) there is a positive correlation between the soil carbon flux and the soil moisture content.     

热轧带钢横向温度研究方法及测量分析

对目前带钢横向温度分布的研究方法和结论进行了分析;对1800热连轧机精轧出口带钢的横向温度进行测量,针对典型的分布规律,提出了描述参数,并用该参数就其分布规律以及分布与带钢宽度、纵向温度的关系进行了讨论,为建立热连轧带钢横向温度控制模型提供了依据.     

西沙蒸发量的时间变化特征及与日照时间和近地面风速的关系

用中国西沙站1962-2004年月蒸发量、日照时间和近地面风速资料,分析了西沙各季节蒸发量的时间变化特征及其与日照时间、近地面风速变化的关系。结果表明:西沙春、夏和冬季蒸发量以年代际变化方差占优,年际变化方差次之;秋季蒸发量的年际变化方差和年代际变化方差相当。四季蒸发量年代际变化与近地面风速、日照时数的年代际变化都有显著的正相关。而蒸发量的年际变化仅与日照时数的年际变化有显著的正相关。四季蒸发量减弱的变化趋势是由近地面风速的减弱和太阳辐射的减少造成的。     

含B2O3高MgO炉渣组成对熔渣体积质量及表面张力的影响

用化学试剂氧化物配制合成宫硼渣，在ＺＣ－１６００型综合测试仪上，用双柱联称法同时测定富硼渣熔体体积质量及表面张力．体积质量在２．５±０．５ｇ·ｃｍ－３范围，表面张力在０．４～０．６Ｎ·ｍ－１范围内变化．二者均随渣中ＭｇＯ量的增加，或随ＳｉＯ２量的减少而增大，随温度的提高而减小．     

钼－棓酸配位吸附波的研究

在ｐＨ４．５的ＮａＡｃ－Ｈ２ＳＯ４缓冲溶液中，用单扫描示波极谱法可得到钼－棓酸配位化合物吸附波，峰电位为－０．８０Ｖ（ｖｓ．ＳＣＥ），二次导数波高与钼浓度在４．０×１０－８～８．０×１０－６ｍｏｌ／Ｌ范围内呈线性关系，最低检出限达１．０×１０－８ｍｏｌ／Ｌ．方法已应用于水样、金属样和食用植物中微量钼的测定，结果满意．利用线性扫描伏安法等对配位化物的伏安行为进行了较系统研究．     

Equal Width波方程的几种新解

应用齐次平衡法再次研究了Equal Width波方程的精确解,在不同的参数下,我求得了几种与文献[1]形式不相同的新解.在这些新解中,有一种孤波解的表达式,比文献[1]中的孤波解的那种表达式更具一般性.     

嵩山夷平面研究

夷平面研究作为一个永远年轻的课题,在经过1890～1910年和1950～1970年两次研究高潮以后,目前再度成为国内外地学界研究的热点,正在酝酿着第三次研究高潮.本文在形态分析、构造分析和相关沉积分析的基础上,确定了嵩山山顶古平坦面是早第三纪晚期形成的夷平面,它可与华北以及全球陆地同期的地形面进行对比.     

光致聚合材料收缩对谱面全息存储的影响

为了分析光致聚合材料记录的谱面全息图在再现过程中发生"擦除"现象,将谱面全息图看作由不同角谱的物光与参考光在光致聚合材料内形成的不同倾斜角度的光栅总和.使用二波耦合理论分析全息图像再现时,由于光致聚合材料发生形体收缩,不同倾斜程度的光栅发生不同程度的变形,产生不同程度的布拉格失配带来的衍射效率变化.理论分析表明,材料收缩越严重,全息图再现质量越差.实验证明了理论分析的正确性,并表明使用无收缩光致聚合材料可以消除这种"擦除"现象.     

基于径向基函数神经网络的滚动轴承故障模式的识别

The impacts of different groove shapes, numbers, and angle of friction dish on transmitting torque, speed, push pressure in wet speeding clutch are discussed in this paper. Since the wet speeed governing clutch works within hydrodynamic lubrication mixture lubrication. boundary, lubrication and contact situation, the oils combining with a-hydrocarbon or polyester are getting widely used as lubricant.The power-law fluid model with Patir-Cheng average flow model, GT asperity contact model and oil film inertia are applied for average Reynolds equation setting, In order to investigate the relationship between average push pressure within hydrodynamic lubrication and mixture lubrication, average transmitting torque and output speed, the numeral calculation and analysis are presented. According to calculation, it is found that the groove shape, groove angle and groove numbers affect the average transfer torque and push pressure with the speed rate.     

表面肌电在攀岩训练中的应用研究

肌肉疲劳产生过程中,肌电图的振幅和频谱指标均会产生相应变化.运用肌电图对运动员肌肉状态指标的评定可以对运动训练起指导作用.肌电图在攀岩领域的应用还比较少,通过对攀岩运动员在间歇训练法训练时的上肢主要做功肌肉左右腕屈肌、左右腕伸肌的的表面肌电信号(sEMG)进行分析,观察肌电图的变化情况,探讨肌电图在攀岩运动过程中应用的可行性.