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91.
Summary We report on the development of an adaptive optimum filter for processing the data of a resonant bar gravitational-wave detector.
This filter, based on the matched-filter theory, is adaptive in the sense that the function it realizes is derived from the
actual noise spectrum of the data being analysed (instead from an idealized model of the noise). Its implementation is mostly
based on frequency domain techniques. We also report on the application of the new filter to the data of the cryogenic antenna
Explorer of the Rome group, with particular reference to the comparison between its performance and that of an otpimum filter
with fixed values of the parameters. 相似文献
92.
We introduce a dynamic force spectroscopy technique enabling the quantitative measurement of conservative and dissipative tip-sample forces in ambient conditions. In difference to the commonly detected force-vs-distance curves dynamic force microscopy allows to measure the full range of tip-sample forces without hysteresis effects caused by a jump-to-contact. The approach is based on the specific behavior of a self-driven cantilever (frequency-modulation technique). Experimental applications on different samples (Fischer-sample, silicon wafer) are presented. 相似文献
93.
94.
共轴均匀带电薄圆盘间的相互作用力 总被引:3,自引:0,他引:3
本文利用静电场的高斯定律和环路定律巧妙地求出了均匀带电圆盘在空间任一点所产生的电场 ,进而计算出了共轴均匀带电薄圆盘之间的相互作用力 相似文献
95.
96.
北京正负电子对撞机重大改造工程(BEPCⅡ)要求其直线注入器提供更高的能量和流强, 为此必须设计大电流和小发射度的新电子枪, 以提高正电子的产额. 利用ANSYS对BEPCⅡ新电子枪的温度场分布及结构的热变形进行了模拟分析. 对于电子枪复杂的内部结构形态以及能量转换方式, 分析了传导传热方式对温度场的影响. 在此基础上进行了温度场与结构变形的耦合分析, 利用EGUN对电子枪形变前后束流光学特性进行模拟分析, 并对模拟结果与试验
测试结果进行了分析比较. 相似文献
97.
Scanning probe microscopy characterization of gold-chemisorbed poplar plastocyanin mutants 总被引:1,自引:0,他引:1
L. Andolfi B. Bonanni G. W. Canters M. Ph. Verbeet S. Cannistraro 《Surface science》2003,530(3):181-194
Two poplar plastocyanin mutants adsorbed onto gold electrodes have been characterized at single molecule level by scanning probe microscopy. Immobilization of the two redox metalloprotein mutants on Au(1 1 1) surface was achieved by either a disulphide bridge (PCSS) or a single thiol (PCSH), both the anchoring groups having been introduced by site-directed mutagenesis. Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) analysis gives evidence of a stable and robust binding of both mutants to gold. The lateral dimensions, as estimated by STM, and the height above the gold substrate, as evaluated by AFM, of the two mutants well agree with crystallographic sizes. A narrower height distribution is observed for PCSS compared to PCSH, corresponding to a more homogeneous orientation of the former mutant adsorbed onto gold. Major differences between the mutants are observed by electrochemical STM. In particular, the image contrast of adsorbed PCSS is affected by tuning the external electrochemical potential to the redox levels of the mutant, consistent with some involvement of copper active site in the tunneling process. On the contrary, no contrast variation is observed in electrochemical STM of adsorbed PCSH. Moreover, scanning tunneling spectroscopy experiments reveal asymmetric I–V characteristics for single PCSS proteins, reminiscent of a rectifying-like behaviour, whereas an almost symmetric I–V relation is observed for PCSH. 相似文献
98.
In this paper experimental study and mathematical modelling of newly designed vibro-impact moling rig are presented. The design is based on electro-mechanical interactions of a conductor with an oscillating magnetic field. The rig consists of a metal bar placed within a solenoid which is connected to an RLC circuit, and an obstacle block positioned nearby. Both the solenoid and the block are attached to a base board. Externally supplied alternating voltage causes the bar to oscillate and hit the block resulting in the forward motion of the base board mimicking a mole penetration through the soil. By varying the excitation voltage and the capacitance in the circuit, a variety of system responses can be obtained.In the paper the rig design and experimental procedure are explained in detail, and the mathematical modelling of the rig is described. Then the obtained coupled electro-mechanical equations of motion are integrated numerically, and a comparison between experimental results and numerical predictions is presented. 相似文献
99.
I. M. Lavit Nguyen Viet Trung 《Journal of Applied Mechanics and Technical Physics》2008,49(3):491-499
The thermoelastoplastic fracture mechanics problem of a thick-walled cylinder subjected to internal pressure and a nonuniform
temperature field is solved by the method of elastic solutions combined with the finite-element method. The correctness of
the solution is provided by using the Barenblatt crack model, in which the stress and strain fields are regular. The elastoplastic
problem of a cracked cylinder subjected to internal pressure and a nonuniform temperature field are solved. The calculation
results are compared with available data.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 173–183, May–June, 2008. 相似文献
100.
DUAL RECIPROCITY HYBRID BOUNDARY NODE METHOD FOR THREE-DIMENSIONAL ELASTICITY WITH BODY FORCE 总被引:1,自引:0,他引:1
Combining Dual Reciprocity Method (DRM) with Hybrid Boundary Node Method (HBNM), the Dual Reciprocity Hybrid Boundary Node Method (DRHBNM) is developed for three-dimensional linear elasticity problems with body force. This method can be used to solve the elasticity problems with body force without domain integral, which is inevitable by HBNM. To demonstrate the versatility and the fast convergence of this method, some numerical examples of 3-D elasticity problems with body forces are examined. The computational results show that the present method is effective and can be widely applied in solving practical engineering problems. 相似文献