一种新型的FIR滤波器

在原有FIR滤波器结构的基础上给出全相位数字滤波器的结构，推导出了全相位数字滤波器的输出公式，并用实验证明全相位滤波器具有良好的滤波频率特性。     

非绝热、非周期演化量子相位特征与测量研究

以二能级原子系统为模型, 细致地研究了非绝热演化量子相位特征. 基于量子干涉原理, 提出了一种测量非绝热演化量子相位的新方法. 且阐述了这种测量方法的物理机理, 利用这种方法在原子态布居几率的干涉条纹中可直接获得量子相位的分布信息.     

层状钙钛矿锰氧化物La_（1.3-x）Gd_xSr_（1.7）Mn_2O_7（x=0,0.05）的磁性和电性研究

采用传统的固相烧结法制备了多晶样品La1.3-xGdxSr1.7Mn2O7（x=0,0.05）,对其磁性和电性进行了研究.研究表明：当x=0.05的Gd掺入后,由于铁磁性的减弱导致样品的磁化强度、二维磁转变温度T2D和三维磁转变温度T3D都随之降低,且在低温下有自旋璃态出现.此外,样品的金属-绝缘体转变温度TM1降低,电阻率增大.以上现象的产生可归结为：由于Gd掺杂导致了晶格失配,减弱了双交换作用,致使上述现象出现.     

缀饰态的几何相位特征及其分布状态研究

以时域对称光场作用下的二能级原子系统为模型, 细致地研究了缀饰态中动力学相位和几何相位的表现形式和分布状态. 利用量子干涉效应, 在理论上提出了实现测量几何相位分布的新方法. 这种测量方法克服了核磁共振和光子回波技术的不足之处, 阐述了测量方法和物理机理.     

Response of tree-ring width to rainfall gradient along the Tianshan Mountains of northwestern China

By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emphasizes the importance of regional-scale investigations into the biosphere-climate interac- tions. The results of this research indicated a substantial increment of tree-ring radial growth as a re- sult of warmer and wetter climate in the eastern regions. However, climate change will have less effect on forest growth and primary production in the western regions.     

变形影响下液滴热毛细迁移运动的瞬态行为

该文研究了在变形影响下的液滴热毛细迁移运动的瞬态行为.研究采波前追踪法描述可变形液滴的运动界面,整个控制方程使用有限差分法进行离散求解.随着液滴向高温区域迁移,液滴界面上平均界面张力不断减小,导致液滴变形不断增大.为此我们引入了一个实时毛细数以描述迁移过程中液滴在不同温度下的界面张力大小.研究发现随着液滴变形不断增大,密度小于/大于母液密度的液滴迁移速度会持续降低/增加.     

和频过程中的绝热与透热过程

基于原子绝热布居转移理论和研究方法，研究了和频过程中的绝热和透热物理过程，得到了绝热条件；以绝热和透热过程的新视角阐释了和频过程中能量转换的物理机理,揭示出利用QPM效应实现和频转换过程中能量转换点的位置与透热过程的联系．     

Spatial pattern of modern sedimentation rate of Qinghai Lake and a preliminary estimate of the sediment flux

We investigated the spatiotemporal distribution of1 37Cs radioactivity in surface sediment of Qinghai Lake,and developed the spatial pattern of sedimentation rate.The1 37Cs inventory is higher near the estuary/bank area,but lower at the central lake.On the other hand,the average1 37Cs activity is lower near the estuary/bank area,but higher at the central lake.The mass accumulation rate(MAR) and the fluxes and contents of the terrestrial detritus(e.g.SiO2,Fe2O3,and Ti) are higher near the estuary/bank area,b...