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In this paper a new recursive DFT is proposed based on sum-and-difference formula of trigonometrical function and solution of linear equations. Its computation work is nearly the same as that of traditional recursive DFT, but it can solve many problems effectively which can't be solved easily by traditional recursive DFT, such as algorithms for overcoming attenuation direct-current component part existing in power system.

文中基于三角函数的和差公式以及线性方程组的求解，提出了一种新的递推离散傅里叶变换算法，它的计算量与传统递推算法接近，但可以解决传统递推算法不易解决的许多问题，如适用于人们提出的克服电力系统中衰减直流分量对DFT影响的一些方法中，因而具有广阔的应用前景。

Based on a computing model of floor heating residences, indoor thermal environment and heat distribution under the effect of heat charge/discharge, operation control and solar radiation has been concluded. Concept and formula of equivalent heat supply has been put forward which indicate that actual heat supply will be equal to the sum of design heat supply and equivalent heat supply. Recommend coefficient has been given taken Dalian as an example. Computed according to the new method, design heat supply can be reduced to 37% in cloudy day and 43.3% in sunny day, energy saving effect is very obvious. In Tromb wall solar house, effect of concrete wall on indoor temperature swing and attenuation of temperature wave is very obvious. While the outdoor air-temperature swing exceeds 10℃, indoor air-temperature swing belows 3℃. In the experiment, maximal difference in temperature between inner surface and outer surface of the 300mm wall exceeded 10℃. Heat storage and collector efficiency varies adversely according to solar radiation. Factors such as thickness, material, absorptance of the wall and permeation of the glass cover all have big influence on heat storage and collector efficiency. There exsisted an optimal thickness of the wall, which can make the best of heat storage and collector efficiency. Most of the heat stored in conventional Trombe wall during the daytime has been lost to the outside at night without heat preservation. Heat preservation on the outside surface of the wall has effectively improved heat release performance of the wall at night, heat supply to the room has increased too.

通过建立的地板采暖系统动态热性能分析模型，得出了在蓄放热特性、运行方式和太阳辐射等因素耦合作用下的室内热环境及热量分配比例，提出了等效供热量的概念及计算公式，指出实际所需供热量应等于设计供热量加上等效供热量，并以大连为例，给出了等效供热量的修正系数，以新方法计算，阴天可减少设计供热量37％，晴天最大可以减少设计供热量43.3％，节能效果显著；集热蓄热墙式太阳房中，混凝土蓄热墙的室温均一化效果和对温度波的削减作用非常明显，当室外温度波动最大幅度超过10℃时，室温波幅不超过3℃，实验中300mm厚墙体内外表面温差超过10℃；墙体蓄热效率与集热效率随太阳辐射照度的变化呈相反的变化趋势；墙体厚度、材料、表面吸收率以及盖板透过率等因素对集热和蓄热效率均有较大的影响，存在一个最佳的墙体厚度值，使得墙体集热和蓄热综合性能最优；传统的蓄热墙夜间没有外保温，辐射散热损失很大，研究表明墙体外保温方式明显改善了蓄热墙夜间的散热性能，增加了向室内的供热量。

Experiments are developed on different aspects, including the thickness of aluminum filter, choosing of the unattenuated data or not, characteristics of X-ray spectra, sensitivities to errors of attenuation data. Conclusion is that the iteration method is the best estimation technique.

以铝板作为滤波器材料，论文在滤波器厚度（包括最大厚度和最小厚度的选择）、未衰减数据的选取与舍弃、韧致辐射谱和包含特性辐射的光谱、对衰减误差的敏感性等多个层面进行仿真实验，比较分析了矩阵法和迭代法的优缺点，认为迭代法是进行光谱估计的最好方法。

In the telecom devices and digital networks, it can guarantee the digital or analogy signal which is transformed has low attenuation and unconspicuous distortion. All of these requests determine the important status of transmission line transformers in modern telecommunication.

包括在电信设备和数字网络中，要求使传输的模拟或数字信号有低的衰减，以及无明显的失真，这些都决定了传输线变压器在现代通信中的重要地位。

The specific gravity of degassed and undistilled beer sample plus real extract solution are determined in this method.The results of alcohol,real extract,original extract and real degree of attenuation etc.can be shown through the running of software program.

摘 要：通过测定脱气而不蒸馏的啤酒样品及浸出物溶液的比重，在开发的软件程序上运行后可得出酒精度、真正浓度、原麦汁浓度及真正发酵度等参数结果，该方法不需额外实验室硬件投入，比GB4928—91标准中蒸馏法测酒精度及原麦汁浓度含量提高效率8倍。

Objective To determine the correlation between unenhanced CT attenuation value and signal intensity loss on opposed-phase chemical shift MR imaging of adrenal tumors.

目的探讨肾上腺肿瘤的平扫CT值与磁共振化学位移成像反相位信号丢失程度的相关性。

A series of experiments were conducted to study absorption, biodegradation and volatilization in natural attenuation of diesel pollution in sand layer of vadose zone quantitatively.

通过实验定量研究了柴油污染包气带砂层自然衰减过程中吸附、生物和挥发作用。

According to the analysis of relations between optical power,center wavelength,sensing fiber Verdet constant,and Fiber Optic Current Transformerscale factor,it was demonstrated that the center wavelength excursion generated by power attenuation of SLD was the prime reason of FOCT scale factor error.

通过分析光源功率、中心波长、传感光纤Verdet常量，以及闭环光纤电流互感器变比之间的关系，结合测试数据，证明了中心波长漂移是光源功率衰减引起闭环互感器变比变化的主要原因。

Taking the Liu'an Huoshan seismic risk area as an example, the authors have carried out a three dimensional analysis of the area, and predicted the potential location of future earthquake and its corresponding parameters including focal depth, magnitude, and the attenuation direction of the isoseism.

在执行中国地震局&九五&课题&江淮地区地震区划的研究&等项目的过程中，基于上述认识，笔者重点对具有中强震过渡区特色的鲁苏皖地区的地震构造环境开展了系统研究，具体采用宏观和微观相结合的综合研究方法，充分利用了现有的地表和深部研究成果。

AIM: To label bone marrowderived stem cells with superparamagnetic iron oxid and to explore the image characteristics and signal attenuation rules of in vivo the magnetic resonance imaging of the labeled cells in rabbit liver.

目的：探讨超顺磁性氧化铁标记骨髓干细胞的方法和标记细胞在肝脏内的磁共振活体成像特点和衰减规律。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。