一次梅雨锋降水系统三维风场双、三雷达对比研究

2002年，“我国重大气候和天气灾害的形成机理与预测理论研究”项目首次启用三多普勒天气雷达组网对暴雨系统进行同步观测，作者使用MUSCAT技术对6月24日梅雨锋雨带上的一个中β系统进行了双、三多普勒雷达三维风场对比分析，表明大气中低层辐合线是此次暴雨系统的一个重要特征。     

双多普勒雷达风场反演误差和资料的质量控制

提出了用双多普勒雷达观测资料进行回波强度、径向速度和方位定位的质量控制方法，以及利用概率分布法订正配对的双多普勒雷达回波强度的方法。以2001年973“中国暴雨”外场试验期间获取的双多普勒雷达观测资料为例，比较了合肥、马鞍山和宜昌、荆州的两对双多普勒雷达同步观测的回波强度、径向速度和方位的改变对观测数据对比的影响；分析了这两对双多普勒雷达径向速度测量误差引起的风场反演的误差。结果表明:两对双多普勒雷达观测的回波强度和径向速度的空间位置和变化趋势比较一致，合肥与马鞍山雷达的回波强度有一定差异，径向速度也有1～2 m/s的差异。风场反演的误差与风场的方向、大小、空间位置等有关。在两个径向速度夹角在40°～140°范围内，共面上的风场的反演误差在1～2倍的雷达探测径向速度的误差范围内。     

用GMS双谱资料估计湿度场及其在数值预报中的应用

对GMS红外和可见光两个通道的资料进行了处理，并估计出了700 hPa和850 hPa两个层次的湿度场。将卫星资料估计的湿度场取代数值模式通常的客观分析湿度场进行了对比业务试验。业务运行表明，应用卫星资料后，预报结果有较大改进。     

94/220 GHz星载雷达双波长比对非球形冰晶云参数敏感性分析

利用不同形状冰晶的散射特性,获得了非球形冰晶云的94/220 GHz测云雷达双波长比,探讨了非球形冰晶云的双波长比与云内微物理参数的关系,分析了衰减前后的星载雷达反射率因子及双波长比的垂直廓线。结果表明:（1）双波长比可以反映小到0.1 mm中值尺度的冰粒子,对粒子总数、谱的形状参数不敏感,对粒子大小、形状、云衰减较敏感。（2）雷达灵敏度一定时,星载雷达可测云厚与雷达波长、冰含水量（IWC）的垂直分布、云厚及衰减有关;没有进行衰减订正时,双波长比和衰减有关,冰含水量越大,波长越短,衰减越大,双波长比最大值与可探测云厚有关。两部雷达可探测冰含水量为0.001—0.1 g/m3、厚2 km的冰云;当云厚5 km、冰含水量垂直分布在0.001—0.2 g/m3时,云厚的94%基本可以被220 GHz云雷达探测到。（3）如果两部雷达气象方程中用水的介电因子,测量回波强度应进行介电因子的订正后再计算双波长比。      

A contribution to seismic shear design of R/C walls in dual structures

The paper focuses on the seismic response of walls in dual (frame + wall) structures, with particular emphasis on shear behaviour. Although dual structures are widely used in earthquake-resistant medium-rise and high-rise buildings, the provisions of modern seismic codes regarding design of walls for shear are not fully satisfactory, particularly in the (common) case that walls of substantially different length form part of the same structure. Relevant provisions of the leading seismic codes are first summarised and their limitations discussed. Then an extensive parametric study is presented, involving two multistorey dual systems, one with identical walls, and one with walls with unequal length, designed to the provisions of Eurocode 8 for two different ductility classes (H and M). The walls of the same structures are also designed to other methods such as those used in New Zealand and Greece. The resulting different designs are then assessed by subjecting the structures to a suite of strong ground motions, carrying out inelastic time history analysis, and comparing the results against design action effects. It is found that although modern code procedures generally lead to satisfactory performance (differences among them do exist), the design of walls seems to be less appropriate in the case of unequal length walls. For this case a modified procedure is proposed, consisting of an additional factor to account for the relative contribution of walls of the same length to the total base and an improved envelope of wall shears along the height; this improved method seems to work better than the other procedures evaluated herein, but further calibration is clearly required.     

Inversion of interference hydraulic pumping tests in both homogeneous and fractal dual media

This work proposes a complete method for automatic inversion of data from hydraulic interference pumping tests based on both homogeneous and fractal dual-medium approaches. The aim is to seek a new alternative concept able to interpret field data, identify macroscopic hydraulic parameters and therefore enhance the understanding of flow in porous fractured reservoirs. Because of its much contrasted sensitivities to parameters, the dual-medium approach yields an ill-posed inverse problem that requires a specific optimization procedure including the calculation of analytical sensitivities and their possible re-scaling. Once these constraints are fulfilled, the inversion proves accurate, provides unambiguous and reliable results. In the fractal context inverting several drawdown curves from different locations at the same time reveals more accurate. Finally, hydraulic parameters drawn from inversion should be taken into account to improve in various situations the conditioning of up-scaled flow in fractured rocks.     

单片机电话计时计费器的设计

本文介绍了一个以单片机为核心的电话单机计时计费器的设计。提出了一种识别脉冲拨号和双音多频拨号的方法,同时在设计中充分利用了单片机的资源,注意发挥软件功能。因此使该设计具有结构合理,使用方便,性能价格比高的特点。     

双线偏振雷达的降水估测Ⅰ. 排序配对逼近法

提出使用新的途径──排序配对逼近法得出的双线偏振雷达降水估测ＺＲ关系参数因子比线性拟合法具有更好的代表性,且能体现提高区域降水估测精度,也能根据实际情形采用其它的误差类型作为获取及衡量参数的标准。对指数函数形式的ＺＲ关系来说,其参数因子Ａ０,ＡＨ及ＡＤＲ分别为０．０１６８４,０．０９６和－０．４１６５。该方法可以推广应用到多个变元及参数因子的复杂函数中。     

Salt weathering in dual-porosity building dolostones

The influence of rock fabric on physical weathering due to the salt crystallization of selected brecciated dolostones is discussed. These dual-porosity dolostones are representative of heterogeneous and anisotropic building rocks, and present highly complex and heterogeneous rock fabric features. The pore structure of the matrix and clasts is described in terms of porosity and pore size distribution, whereas the relative strength for each textural component is assessed using the Knoop hardness test. The whole characterisation process was carried out using the same samples as those used in the standard salt durability test (EN-12370), including connected porosity, the water saturation coefficient, fissure density, compressional wave velocity and waveform energy.

Results show the most important rock fabric elements to be considered are the matrix and clast properties and the nature of fissures. Firstly, a relatively weak matrix was the focus of major granular disintegration as it presents high porosity, low pore radius and reduced strength. Secondly, narrow micro-fissures appear to be important in the decay process due to the effectiveness of crystallization pressure generated by salt growth. On the contrary, macro-fissures do not contribute greatly to rock decay since they act as sinks to consume the high supersaturations caused by growth of large crystals. Additionally, an analysis of stress generated by crystallization was carried out based on the general situation of a lenticular crystal geometry. Finally, the relationships between whole petrophysical properties and durability were established using a principal component analysis. This analysis has clearly established that the durability of rocks affected by salt crystallization mechanisms diminishes in weaker and anisotropic rocks with high porosity and fissure density.