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1.
对原有的表面分形维数的计算方法进行了简化 ,藉此可以利用压汞或其他分析方法获得的孔分布信息计算出多孔介质的表面分形维数 .Sierpinski海绵的自相似性分析结果显示其内表面只在局部范围内存在标度不变性 .应用获得的简化计算方法分析自相似范围内 Sierpinski海绵的孔分布信息发现 ,由本文的标度关系计算出来的表面分形维数与其理论值非常吻合 ,这一结果从理论上证明了该标度关系的正确性 . 相似文献
2.
Based on the laboratory experiments with the saltwater and freshwater replacing each other in the level sand column, taking the kaolin, illite, smectite, bivalent hydrargyrum ion (Hg2+) and phenol (C6H5OH) as exam-ples, this paper studies the applications of water sensitivity in situ remediation in saltwater-freshwater transition zone. In the water sensitivity process, the release and migration of clay minerals can make the hydraulic conductiv-ity (HC) decrease and pollutants remove. A new type of low penetrable or impenetrable purdah can be built by adding clay minerals into the sand media to replace the underground concrete impenetrable wall to prevent seawater intrusion, and a number of the heavy metals and organic pollutants in the sand media can be removed by in situ remediation. The results show that the content of kaolin and illite influences the water sensitivity process slightly, and HC of the sand columns descends from 0.011 cm/s to 0.001 4 cm/s and 0.001 2 cm/s respectively even if the content reaches 12% (weight ratio, sic passim). However, for smectite, HC descends sharply to about 1×10-8 cm/s when its content reaches 4%, and no water can flow through the sand columns beyond 5%. The particle release and migration processes can remove the Hg2+ and C6H5OH out of the sand columns efficiently, the removing rate of Hg2+ is 31.68% when the freshwater and saltwater are filtered through the sand columns polluted by Hg2+, while it is 67.55% when the water sensitivity occurs. With the same method, the removing rates of C6H5OH under the fluid flow and water sensitivity are 55.71% and 43.43% respectively. 相似文献
3.
Numerical investigation on the phase change of water-saturated porous media with thermosyphon 总被引：1，自引：0，他引：1
Numerical investigations were carried out to determine the coupled heat transfer of water-saturated porous media with a two-phase
closed thermosyphon for soil freezing, and to examine the characteristics of the freezing heat transfer in the water-saturated
porous media. The whole control volume includes the thermosyphon and the porous media. The two-dimensional governing equations
for the water-saturated porous media are used.
The conjugation of heat transfer between the thermosyphon and porous media is reflected through thermal balance between the
thermosyphon and the porous media.
The finite-difference method was used to solve the two-dimensional goverming equation, for the water-saturated porous media
and the heat transfer characteristics of the thermosyphon, obtain the flow fields and the temperature distributions in the
soil. This paper deals mainly with the effect of some factors (such as soil properties, climate and thermosyphon dimensions)
on the heat transfer rate of the thermosyphon and the growth of the freezing front. The predictions of the present study agree
well with the measured data. 相似文献
4.
ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｃｏｌｄｒｅｇｉｏｎｓ,ｓｏｉｌｅｘｐａｎｓｉｏｎｒｅｓｕｌｔｅｄｆｒｏｍａｓｏｉｌｆｒｅｅｚｉｎｇｐｒｏｃｅｓｓｏｆｔｅｎｄｅｆｏｒｍｓａｎｄｄａｍａｇｅｓｓｏｍｅｃｏｎｓｔｒｕｃｔｉｏｎｆｏｕｎｄａｔｉｏｎｓ.Ｏｎｅｗａｙｔｏｓｔａｂｉｌｉｚｅｔｈｅｆｏｕｎｄａｔｉｏｎｉｓｕｓｅｏｆｔｗｏｐｈａｓｅｃｌｏｓｅｄｔｈｅｒｍｏｓｙｐｈｏｎｉｎｔｈｅｃｏｌｄｒｅｇｉｏｎｓ.Ｄｕｅｔｏｉｔｓｅｘｃｅｌｌｅｎｔｈｅａｔｔｒａｎｓｆｅｒｃｈａｒａｃｔｅｒｉｓｔｉｃｓ,ｔｈｅｔｗｏ… 相似文献
5.
描述絮团分形结构的定量参数分维数可用沉降法、图像法等进行测量。本文提出了一种测量絮团分维数的新方法,即通过测量絮凝体系的表观粘度而获得絮团的分维数(文中名之为粘度分维数)。为此,将絮团依据其空间特征分成四类:分散的单体颗粒、线状絮团、面状絮团及体状絮团,类比说明体系粘度为分散相及各类絮团对体系粘度贡献的线性叠加。通过颗粒碰撞理论及絮团的绕流阻力分析殊途同归地得出了体系粘度与各类絮团分维数的数学模型。依据该模型,可以同时测量不同类型絮团的分维数,并使定量分析絮团的相对组成成为可能。 相似文献
6.
分形方法可以模拟传统欧氏几何方法所不能描述的各种自然景物。运用分形几何学原理和方法,利用Java可以绘制出具有真实感的自然景物。在此给出了分形插值算法绘制云彩的实现过程。结果表明,此方法对自然景物的模拟非常逼真,可以在虚拟场景的自然景物生成中得到应用。 相似文献
7.
基于分形维前臂动作表面肌电信号的分类 总被引：1，自引：0，他引：1
通过分形维对表面肌电信号进行识别分类.在30个健康志愿者做前臂内旋和外旋时,从他们的右前臂肌前群分别采集2类动作表面肌电信号.当原始动作表面肌电信号用小波包变换分解成几个子信号后,采用一种基于模糊自相似性的方法计算原始信号和4个子信号的分形维.结果表明:从频带0～125 Hz的子信号求得的内旋和外旋动作表面肌电信号的分形维有各自的范围;通过该分形维进行Bayes决策时,错误识别率仅2.26%.因此,该分形维适合用来识别内旋和外旋动作表面肌电信号. 相似文献
8.
Based on the laboratory experiments with the saltwater and freshwater replacing each other in the level sand column, taking
the kaolin, illite, smectite, bivalent hydrargyrum ion (Hg2+) and phenol (C6H5OH) as examples, this paper studies the applications of water sensitivity in situ remediation in saltwater-freshwater transition zone. In the water sensitivity process, the release and migration of clay
minerals can make the hydraulic conductivity (HC) decrease and pollutants remove. A new type of low penetrable or impenetrable
purdah can be built by adding clay minerals into the sand media to replace the underground concrete impenetrable wall to prevent
seawater intrusion, and a number of the heavy metals and organic pollutants in the sand media can be removed by in situ remediation. The results show that the content of kaolin and illite influences the water sensitivity process slightly, and
HC of the sand columns descends from 0.011 cm/s to 0.001 4 cm/s and 0.001 2 cm/s respectively even if the content reaches
12% (weight ratio, sic passim). However, for smectite, HC descends sharply to about 1×10−8 cm/s when its content reaches 4%, and no water can flow through the sand columns beyond 5%. The particle release and migration
processes can remove the Hg2+ and C6H5OH out of the sand columns efficiently, the removing rate of Hg2+ is 31.68% when the freshwater and saltwater are filtered through the sand columns polluted by Hg2+, while it is 67.55% when the water sensitivity occurs. With the same method, the removing rates of C6H5OH under the fluid flow and water sensitivity are 55.71% and 43.43% respectively.
Supported by National Natural Science Foundation of China (No. 40572142).
HAN Zhiyong, born in 1976, male, Dr, associate Prof. 相似文献
9.
谭启建 《四川教育学院学报》2013,29(5):105-108
利用Darcy定律和质量守恒定律,得到了含多种多孔介质区域中可压缩流体流动的数学模型;在适当的假设条件下,利用上下解方法,得到了模型解的存在唯一性。 相似文献
10.
A laser collimating system based on 2-D position sensitive detector (PSD) is presented in this paper. The working principle of PSD is depicted in detail. A calibration device was developed to check the nonlinearity errors of PSD and a multilayer feedforward neural network based on error back-propagation algorithm was used to compensate errors. With the aid of computer-based data acquisition system, an automatic dynamic measuring process was realized. A series of experiments, including comparison tests with laser interferometer, were done to evaluate the performance of the measuring system. The experimental results show that the spatial straightness errors of guide rails can be measured with high accuracy. The maximum differences between the device and laser interferometer are 0. 027 mm in Y direction, and 0. 053 mm in X direction in the measuring distance of 6 m. 相似文献
11.
混沌投资时间序列的分形维数谱 总被引：4，自引：0，他引：4
许清海 《泉州师范学院学报》2002,20(6):8-12
不同文献对沪指和深指的分形维数的计算结果相差甚大，究其原因，除计算方法，计算误差外，更深层次的原因是混沌投资时间序列分形维数谱的存在，本文对混沌投资时间序列分形维数的信息谱，奇异谱，动熵谱等问题进行探索，并简介其应用。 相似文献
12.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｉｎｓｐｅａｋｅｒｉｄｅｎｔｉｆｉｃａｔｉｏｎ ,ａｍａｊｏｒｐｒｏｂｌｅｍｉｓｔｏｓｅｅｋｅｆｆｅｃｔｉｖｅ ｐａｒａｍｅｔｅｒｓｆｏｒｃｈａｒａｃｔｅｒｉｚｉｎｇｉｎｄｉｖｉｄｕａｌｓｐｅｅｃｈ .Ｎｏｎｌｉｎｅａｒｄｙｎａｍｉｃｓｏｆａｉｒｆｌｏｗｄｕｒｉｎｇｓｐｅｅｃｈｐｒｏｄｕｃｔｉｏｎｍａｙｏｆｔｅｎｒｅｓｕｌｔｉｎｔｕｒｂｕｌｅｎｃｅ ,ｂｏｔｈｓｍａｌｌａｎｄｌａｒｇｅ[1,2 ] .Ｉｎｓｏｍｅｃａｓｅｓｔｈｉｓｍｕｌｔｉ ｓｃａｌｅｓｔｒｕｃｔｕｒｅｏｆｔｕｒｂ… 相似文献
13.
以公路客运量为规模参数分析了1997年至2004年中国前200位主要公路客运枢纽规模分布的分形特征,采用精确计算方法得到历年公路客运枢纽规模分布的分维数.发现中国公路客运枢纽体系的规模分布符合从双分形到单分形发展的结构特征,2000年至2004年规模分布维数介于1.486 2～1.5118之间.这与城镇体系规模分布维数一致,说明现阶段中国公路客运枢纽体系与城镇体系规模分布结构相适应.结果表明,公路客运枢纽体系处于较好发展阶段,政府需加强大型公路客运枢纽建设推动其结构优化. 相似文献
14.
Cong-jing REN Jing-dai WANG Di SONG Bin-bo JIANG Zu-wei LIAO Yong-rong YANG 《浙江大学学报(A卷英文版)》2011,12(4):260-267
Particle size distribution (PSD) is an important parameter in the process of fluidization, and it always plays a crucial role
in a gas-solid fluidized system. A PSD model for on-line PSD determination based on acoustic emission (AE) measurement was
developed according to the mechanism of particle collision with the inner wall of the cylinder and multi-scale wavelet decomposition
analysis. This PSD model illuminates the quantitative relationship between the energy percentage of AE signals for different
scales and the PSD, which indicates the feasibility of the application of the PSD model. Experiments were undertaken both
in lab and plant gas-solid fluidized setup with polyethylene particles, and the parameters of the PSD model were calibrated
and revised. The experimental conditions and results proved that the PSD model was suitable for on-line measurement and was
sufficiently sensible and accurate. Concerning agglomeration, the PSD model also showed exact serviceability on detecting
the onset of agglomeration by abnormal PSD, and the result agreed with that from the radiation method. Ultimately, AE measurement
was found to be a reliable and credible means for understanding the PSD information that affects the behavior of a system,
which can provide valuable guidance for practical applications. 相似文献
15.
王怀玉 《绵阳师范学院学报》2000,(5)
以地豆 (PhaseolusVulgarisL .)为宿主植物 ,接种摩西球囊霉(G mosseae) ,以混合沙、壤土、草碳、沸石、蛭石为基本原料 ,按照不同比例配制成九种基质 ,比较了它们对VA 菌根接种剂质量的影响。 相似文献
16.
王建军 《洛阳工业高等专科学校学报》2008,18(1)
阐述了花岗石表面轮廓的特点,提出对原始轮廓曲线进行高斯滤波,然后进行粗糙度及分形计算的方法:并对花岗石表面光泽度和粗糙度、分形维数之间的关系进行了研究.通过分析认为高斯滤波适合花岗石表面轮廓的粗糙度及分形研究,计算方法可靠、简捷. 相似文献
17.
选取三个辽东半岛丘陵区山前冲积平原典型棕壤为研究区,在野外调查的基础上,运用比重瓶法、重铬酸钾—硫酸氧化法对其棕壤的物理和化学性质进行分析,进一步研究采集土样的土壤特性。研究结果表明：（1）各发生层厚度差异较大,比重从上至下依次增大;（2）同一土壤剖面不同发生层有机质含量从上至下依次递减,全磷依次递增;（3）不同土地利用类型的棕壤中,林地有机质含量最大,果园与菜地有机质含量差异不大;菜地全磷最大,果园与林地差异不显著。这些地区土壤肥力较高,适宜进行农业生产活动。 相似文献
18.
上海人口郊区化的分形研究 总被引：1，自引：0，他引：1
运用分形理论,以上海为研究区域,结合统计分析、GIS分析技术,测算上海人口分形分维数,依据分形理论对上海区域进行人口分布和郊区化的分维刻画,探讨上海人口郊区化空间推进的规律,可以得出以下结论:人口分布分形维数的测算表明,上海人口郊区化以来,全市及中心城区的人口分布的集聚程度有所缓和,人口分形性态呈现优化,但是上海人口郊区化目前还只是近郊郊区化,还没有发展到远郊郊区化. 相似文献
19.
INTRODUCTION Surface EMG signal recorded from the skin surface over limb muscles in the process of limmovement is called action surface EMG (ASEMGsignal. Containing the electrical and functional properties of limb muscle contraction and providing thinformation on the neuromuscular activity fromwhich ASEMG signal originates, ASEMG signal habeen widely applied in rehabilitation and the controlof prosthetic devices for the individuals with amputations or congenitally deficient limbs … 相似文献
20.
CHENG Jin TAN Jian-rong 《浙江大学学报(A卷英文版)》2007,8(1):134-141
INTRODUCTION Mandelbrot and Julia sets have been extensively investigated in great detail in terms of their aestheti-cally pleasing geometrical shapes, infinite detail, self-similarity, periodicity and many other character-istics. The beauty and intricacy of these sets in the complex plane stimulate the scholars’ enthusiasm for viewing sets that occupy more than two dimensions. However, investigations on the generalizations of fractal sets to higher-dimensional spatial space have come u… 相似文献