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81.
G. Pizzella 《Il Nuovo Cimento C》1995,18(3):285-294
Summary A brief historical survey of the GW experiments is presented. In particular, the experiments with resonant detectors are illustrated
and the problems arising when comparing data of different detectors for the search of coincidences are discussed. The experimental
results so far obtained are shown, among them the correlation during the SN1987A with various GW and neutrino detectors. Finally
a warning for the long times needed to improve the sensitivity of the GW detectors is given and the improvements expected
with spherical resonant detectors are mentioned. 相似文献
82.
高分辨方位估计特征分解法是一类性能良好的方法,本文从水下阵列信号处理的实际应用出发,对这类方法进行了C30硬件实验研究,所得结果为高分辨技术的实际应用提供了重要依据文中构造了高分辨方位估计的C30硬件实验系统;并实现了高分辨方位估计的Pisarenko法、MUSIC法、Johnson法和最小摸(Mininorm)法;对高分辨实验系统进行了仿真实验和消声水池实验,并测试了各特征分解法的运行时间.结果表明,高分辨C30实验系统表现了良好的方位估计统计性能和实时性能 相似文献
83.
A sonic spray ionization (SSI) interface for liquid chromatography-mass spectrometry (LC-MS) analysis was optimized for analysis of 2-[(1R)-3-[bis(1-methylethyl)amino]-1-phenylpropyl]-4-methyl-phenol (tolterodine), used as a model drug substance, and the influence of different parameter settings was evaluated using factorial design. A comparison between SSI and electrospray ionization (ESI) was made for tolterodine, tolterodine metabolites, and a set of steroids.SSI was found to give slightly poorer repeatability and broader peaks for tolterodine compared to ESI. However, there was no significant difference in chromatographic peak shape, and the repeatability using SSI was similar to that obtained using ESI if a ratio (area of tolterodine/area of metabolite) was used. In this study, the sensitivity was higher using SSI. For the analysis of pregnanolone, less water loss was obtained using SSI, probably due to less energy being transferred to the analyte upon ionization. 相似文献
84.
D.M. Svirachev 《Applied Surface Science》2007,253(9):4232-4241
In the following paper, empirical constants are determined by a plasma-chemical model and experimental data of the wetting contact angle. The constants characterize the alteration of the contact angle as a function of the time of the polymer treatment and the kind of the plasma-creating gas. The presented equations of the model connect the contact angle with the empirical constants for arbitrary time intervals of treatment and arbitrary percentage content of the researched gas mixtures and gasses. The chemical rate constants, which describe the process of the plasma modification of the polymer material, are determined. 相似文献
85.
86.
The modified Blalock-Taussig shunt is a connection created between the systemic and pulmonary arterial circulations to improve pulmonary perfusion in children with congenital heart diseases. Survival of these patients is critically dependent on blood flow distribution between the pulmonary and systemic circulations, that in turn depends upon the fluid dynamic behaviour of the shunt. Computational fluid dynamics, structural analyses as well as in vitro experiments were carried out to derive a quantitative relationship between the shunt flow and the corresponding pressure drop. While computational fluid dynamics simulations were based on the assumption of rigid wall for the shunt and the arteries, proper distensible conduits were used in the in vitro study and the structural analysis of the anastomosis deformation. The results indicated that the internal pressure combined with wall distensibility modifies the cross-sectional area of the distal anastomosis (between the shunt and the pulmonary artery). This fact affects the pressure drop across the shunt, especially at low pressures. Based on the results from the computational analyses and the in vitro experiments, a relationship between pressure drop and flow in the shunt was obtained, which matches data from clinical measurements. 相似文献
87.
非饱和土的广义朗肯土压力 总被引:1,自引:0,他引:1
本文从 4条基本假设出发 ,建立了非饱和土的广义朗肯土压力公式 ,采用理想试验对该公式进行了验证 ,在北京地铁13号线的东直门车站基坑工程中理论分析结果和实测值非常接近 ,证明了该理论的有效性。土的广义朗肯土压力公式建立了土的试验指标与原位指标的关系 ,从理论上给出了用土的试验指标得到原位主动 (被动 )土压力的方法。对于非饱和土 ,采用简单易得的直剪试验指标应用广义朗肯土压力公式就可以得到相当精确的结果 ,弥补了扩展朗肯土压力理论的不足。而且广义朗肯土压力公式能够合理利用已有的工程经验和工程数据 ,为非饱和土力学的工程实用化提供了一条新的思路。 相似文献
88.
In-tube magnetic solid phase microextraction (in-tube MSPME) of fluoroquinolones from water and urine samples based on the use of sodium dodecyl sulfate (SDS) coated Fe3O4 nanoparticles packed tube has been reported. After the preparation of Fe3O4 nanoparticles (NPs) by a batch synthesis, these NPs were introduced into a stainless steel tube by a syringe and then a strong magnet was placed around the tube, so that the Fe3O4 NPs were remained in the tube and the tube was used in the in-tube SPME-HPLC/UV for the analysis of fluoroquinolones in water and urine samples. Plackett–Burman design was employed for screening the variables significantly affecting the extraction efficiency. Then, the significant factors were more investigated by Box–Behnken design. Calibration curves were linear (R2 > 0.990) in the range of 0.1–1000 μg L−1 for ciprofloxacin (CIP) and 0.5–500 μg L−1 for enrofloxacin (ENR) and ofloxacin (OFL), respectively. LODs for all studied fluoroquinolones ranged from 0.01 to 0.05 μg L−1. The main advantages of this method were rapid and easy automation and analysis, short extraction time, high sensitivity, possibility of fully sorbent collection after analysis, wide linear range and no need to organic solvents in extraction. 相似文献
89.
90.
The nonlinear dynamics of the same experimental model of an internally resonant hanging elastic cable considered in Part I [1] are addressed here from the point of view of the global system behaviour in the control parameter space. Synthetic results of systematic response measurements, made at different amplitudes of the support motion in frequency ranges including meaningful external resonance conditions, are reported and discussed. Attention is devoted to the detection of the most robust classes of motion. Quite complicated overall pictures of regular response regions with variable contributions from different planar and nonplanar cable modes are observed, as well as several regions of quasiperiodic and chaotic responses. Sample quantitative characterizations of nonregular motions are presented. Some experimental results are also observed against the background of the nonlinear dynamic phenomena exhibited by a theoretical model of a continuous cable with four-degrees-of-freedom. 相似文献