基于波形时域分布特征的变压器励磁涌流识别

提出了一种基于波形时域分布特征的新型变压器励磁涌流识别方法。文中在直方图技术的基础上定义电流波形分布系数,分析了变压器内部故障电流和励磁涌流的波形分布特征,在此基础上将两个不同子区间的分布系数的比值定义为波形分布特征系数,提出了根据该系数大小来识别励磁涌流的具体实现方案,并分析了确定子区间数目的理论依据。利用动模实验和数字仿真数据对本方法做了验证分析,结果表明:本方法计算量小,能快速区分励磁涌流和故障电流,在可靠性和灵敏性等方面的性能优于目前的二次谐波判据和间断角判据。

基于频率分布波形的最小跳频间隔估计算法

针对最小跳频间隔的估计问题,提出了一种基于频率分布波形的最小跳频间隔估计算法。利用跳频信号检测结果中的信号频率构造了一个频率分布波形,从理论上推导了频率分布波形的频谱与最小跳频间隔的关系,给出了基于频率分布波形的最小跳频间隔估计算法的实现方法。仿真结果表明,当跳频信号检测结果中信号频率的误差控制在一定范围内时,算法具有较高的成功率和较小的均方误差。

矿产资源量估计法在金矿中的应用

大比例尺矿床统计预测中 ,矿产资源量的估计是矿体定位预测的前提 ,其中精度最高的方法是体积估计法。文章借助实例分析 ,对体积估计法的计算程序进行了阐述。以区间概率解析法对矿脉和矿化体在垂向空间的金品位进行分解 ,解析出其金品位统计分布模型 ;利用波形分布模型对深部盲区进行预测 ,对各中段的金品位、矿化体体积、矿石在矿化体中的体积分数进行解析和计算 ;并利用有效探矿指数进行合理的校正 ,最后得到近似于地质储量的金矿产资源量 ,为下一步的矿体定位预测提供定量数据。经计算该矿重点预测区 (- 2 90 m～ - 810 m标高 )预测的有效金矿产资源量为 70 .2 8t,经部分工程控制 ,已获 D+E级金储量

动态光散射技术在静脉注射亚微乳剂粒径评价中的应用

目的用动态光散射技术分析粒径大小及分布,为静脉注射乳剂的制备提供指导。方法制备3种不同的维生素E烟酸酯静脉注射亚微乳剂(Ⅰ,Ⅱ和Ⅲ),用Nicomp–380激光粒度测定仪分别测定3种制剂的光子相关光谱,并用离心法测定乳剂的稳定常数(KE)。结果 3种制剂的光子相关光谱有显著差别。制剂Ⅰ的Nicomp多波形分布图为双峰,制剂Ⅱ和Ⅲ的Nicomp多波形分布图为单峰,但制剂Ⅲ的Gaussian粒径分布图比制剂Ⅱ的Gaussian粒径分布图明显窄,且PSDI,PSDV和PSDN重合性很好。得到3个不同的KE值,分别为0.72,0.64,0.51。结论用Nicomp多波形分布图和Gaussian粒径分布图可以指导制剂的制备。

凌海市刘屯金矿成矿地质条件及深部矿化分析

刘屯地区金地球化学异常与构造关系密切,构造对金成矿具有控制作用。20纪90年代以来,本区的采矿活动时断时续,至2011年上半年还有单位在此处开展采矿,因深部矿化减弱而终止。本文就刘屯地区地表和深部金矿化分布特征,阐述刘屯金矿采空区底部赋存金矿的可能性,预测其深部矿化特征。为较清晰显示矿区内地质特征,将全区分两个矿段:分别是金屯和刘屯矿段。近东西构造与北东向脉岩交汇部位是金成矿有利部位,赋存于近东西向构造内的矿体符合波形分布理论;根据矿体分布特征和元素地球化学特征在其深部还有赋矿可能性。

上海应用物理研究所发现纳米水通道的新特性

上海应用物理所方海平研究员等运用分子动力学模拟，对水在亲、疏水表面的性质、生物分子中水的重要性开展了一系列研究工作。通过对蛋白通道的简化模型（具有合适半径的纳米碳管）的分子动力学模拟研究，他们发现这种典型的纳米孔道具有极好的通道特性，即在噪音信号下，其“通”或“关”的状态不受干扰，而在有效信号下，“通”或“关”的状态迅速响应。研究表明，这个优异开关特性的主要原因是纳米碳管内水分子的波形分布。水分子波形中极大极小值出现的空间位置的移动，抵消了纳米碳管彤变对内部水分子的作用，从而使内部水分子的平均个数、流量基本保持不变。

Cauchy prior distribution-based AVO elastic parameter estimation via weakly nonlinear waveform inversion

Cauchy priori distribution-based Bayesian AVO reflectivity inversion may lead to sparse estimates that are sensitive to large reflectivities. For the inversion, the computation of the covariance matrix and regularized terms requires prior estimation of model parameters, which makes the iterative inversion weakly nonlinear. At the same time, the relations among the model parameters are assumed linear. Furthermore, the reflectivities, the results of the inversion, or the elastic parameters with cumulative error recovered by integrating reflectivities are not well suited for detecting hydrocarbons and fuids. In contrast, in Bayesian linear AVO inversion, the elastic parameters can be directly extracted from prestack seismic data without linear assumptions for the model parameters. Considering the advantages of the abovementioned methods, the Bayesian AVO reflectivity inversion process is modified and Cauchy distribution is explored as a prior probability distribution and the time-variant covariance is also considered. Finally, we propose a new method for the weakly nonlinear AVO waveform inversion. Furthermore, the linear assumptions are abandoned and elastic parameters, such as P-wave velocity, S-wave velocity, and density, can be directly recovered from seismic data especially for interfaces with large reflectivities. Numerical analysis demonstrates that all the elastic parameters can be estimated from prestack seismic data even when the signal-to-noise ratio of the seismic data is low.

Acoustic emission characteristics of rock under impact loading

Acoustic emission tests were performed using a split Hopkinson pressure bar system(SHPB) on 50-mm-diameter bars of granite, limestone, sandstone and skarn. The results show that the amplitude distribution of hits is not well centralized around 50 d B, and that some hits with large amplitudes, usually larger than 70 d B, occur in the early stages of each test, which is different from the findings from static and low-loading-rate tests. Furthermore, the dominant frequency range of the recorded acoustic emission waveforms is between 300 k Hz and 500 k Hz, and frequency components higher than 500 k Hz are not significant. The hit with the largest values of amplitude, counts, signal strength, and absolute energy in each test, displays a waveform with similar frequency characteristics and greater correlation with the waveform obtained from the elastic input bar of the split Hopkinson pressure bar system compared with the waveforms of the other hits. This indicates that the hit with the largest values of amplitude, counts, signal strength, and absolute energy is generated by elastic wave propagation instead of fracture within the rock specimen.

Trapping Mechanism for Long Waves over Circular Islands with Power Function Profiles

Long waves such as tsunamis can be trapped by islands due to wave refraction,and these trapped waves will cause huge damage even in the sheltered shoreline of the island.That all waves propagating into the topography and finally reaching the coastline are called perfect trapped modes,while any waves escaping from the topography are called leaky modes.Whether these long waves can be trapped is dependent on the depth profile of the island.This paper presents analytic solutions of the ray path for waves propagating into the circular island with power function profiles.Wave height distributions over the island are further investigated based on the principia that crowded rays correspond to large wave height and sparse rays correspond to small wave height.The trapped mechanism for water waves over the island is revealed based on their ray paths.Furthermore,the perfectly trapped criterion is derived,that is,when the slope gradient at the topography toe is greater than twice the ratio of the water depth to the radial distances,all wave rays propagating on the island will finally reach the coastline,and the waves are perfectly trapped.

Multi-fractal Behaviors of Relative Humidity over China

The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis （DFA） method. Three multi fractal parameters （the spectrum width Aa, the asymmetry Aaas, and the long-range correlation exponent a0） of the singularity spectrum are introduced to quantify the multi-fractal behaviors. The results show that multi-frac tality exists in daily humidity records over most stations in China and is mainly due to the broad distribution of the probability density of the sequence values. Strong multi fractal behaviors over some stations in the Yunnan, Guangdong, and Inner Mongolia provinces are obvious. These behaviors are mainly caused by different long range correlations between large and small fluctuations. The asymmetry of the singularity of relative humidity records is weak, except for a small number of stations in the far east and west of China, where the singularity spec trum is left-skewed. Finally, the long-range correlations in North China are stronger than those in South China, which indicates better predictability in North China. By studying the parameters of the multi-fractal spectrum, various data of long-range power law correlations of the relative humidity records are obtained, which may pro vide theoretical support for climate prediction.

汽轮发电机转子γ系数取值的分析

计算并分析了γ系数对转子磁势在空间分布波形的影响，据此，对γ系数的取值提出了不同的看法．

Morphological Research on Geometrical Scattering Waves of an Underwater Target

In this paper, a new method based on morphologic research named reconstruction cross-component removal （RCCR） is developed to analyze geometrical scattering waves of an underwater target. Combining the origin of the cross-component in Wigner-ViUe distribution, the highlight model of target echoes and time-frequency features of linear frequency-modulated signal can remove cross-components produced by multiple component signals in Wigner-Ville distribution and recover the auto-components of output signals. This method is used in experimental data processing, which can strengthen the real geometric highlights, and restrain the cross components. It is demonstrated that this method is helpful to analyze the geometrical scattering waves, providing an effective solution to underwater target detection and recognition.

Energy-Momentum Distribution of Gravitational Waves

This paper has been addressed to the well-known problem of energy in gravitational waves. We have investigated the energy of cylindrical gravitational waves in the context of General Relativity and teleparallel theory of gravity. For this purpose, the prescriptions of Einstein, Landau-Lifshitz, Bergmann-Thomson, and Moeller are used in both the theories. It is shown that these energy-momentum complexes do not provide equivalent results in the two theories. However, these turn out to be constant for all the prescriptions except Moeller in both the theories at large distances.

Dynamics of Spiral Wave Tip in Excitable Media with Gradient Parameter

Using a Barkley model as an example, we study spirM waves and spiral tips in a gradient excitable medium. The gradient distribution of parameters is introduced to depict the inhomogeneous medium. It is found that the parameter fluctuations play an important role in the morphology of spiral pattern and the movements of spiral tips. For varied gradient parameters, it is observed that there exist three kinds of spiral behaviors, stable rotation, rebound of spiral tip from the boundary, and spiral breakup.

Automated Recovery of the 2012 Sumatera Aftershock Sequence Using Waveform Cross Correlation

We assess the performance of waveform cross correlation as applied to automatic and interactive processing of the aftershock sequence of the April 11, 2012 Sumatera Ms（IDC） = 8.2 earthquake. The XSEL （cross correlation standard event list） is compared to the REB （Reviewed Event Bulletin） issued by the IDC （International Data Centre）. The latter includes 1,181 aftershocks between April 11 and May 25. To automatically recover the sequence, sixteen aftershocks were selected from the IDC SEL3 （Standard Event List） available on April 13 and used as master events. Waveform templates from only seven IMS （International Monitoring System） array stations with the largest SNR （signal-to-noise ratio） for the main shock were used to calculate cross correlation coefficients. Approximately 620,000 arrivals were detected and then used to build events according to the IDC definition. After conflict resolution between event hypotheses with similar arrivals found by more than one master, all survived hypotheses populated the XSEL. The total number of distinct hypotheses was 4,924, with 2,763 hypotheses not matched by the REB, i.e. potentially new REB events. To evaluate the quality of the XSEL, we randomly selected a representative portion （-15%） from 2,763 hypotheses and reviewed them interactively according to standard IDC rules and guidelines. There were 119 new REB events built and 145 XSEL hypotheses rejected. Several frequency and probability density distributions have been constructed for all detections, the associated detections, the XSEL detections, the detections in the new REB, and rejected events.

数控汽车发电机定子绕线机的研制

在消化吸收了国外引进设备的基础上,提出了国产化设计方案并开展研制工作,7对极绕线成型装置是采用了凸轮式绕线成型的工作原理,自行开发研制成功的,增加了进口设备所不具备的功能,解决了进口设备多品种生产拓展性差的不足,提高了发电机定子线圈的生产能力,设备主要性能指标达到进口设备的性能、部分指标优于进口设备的性能,技术达到国外同类产品的先进水平。

Joint Antenna Selection and Robust Beamforming Design in Multi-cell Distributed Antenna System

Most of studies on Distributed Antenna System(DAS) focus on maximizing the sum capacity and perfect channel state information at transmitter(CSIT).However,CSI is inevitable imperfect in practical wireless networks.Based on the sources of error,there are two models.One assumes error lies in a bounded region,the other assumes random error.Accordingly,we propose two joint antenna selection(AS) and robustbeamforming schemes aiming to minimize the total transmit power at antenna nodes subject to quality of service(QoS) guarantee for all the mobile users(MUs) in multicell DAS.This problem is mathematically intractable.For the bounded error model,we cast it into a semidefinite program(SDP) using semidefinite relaxation(SDR) and S-procedure.For the second,we first design outage constrained robust beamforming and then formulate it as an SDP based on the Bernstein-type inequality,which we generalize it to the multi-cell DAS.Simulation results verify the effectiveness of the proposed methods.

Using Array Methods to Identify and Process Weak Signals Generated by the Brightlight(Ⅰ) 50t Explosion

Waveforms generated by the 50t explosion of project Brightlight （ I ） were recorded by HILR array. Using array techniques, the author performed identification, f-k analysis, velocity spectrum analysis, etc. of the weak signals. The analysis results show that the signal-to-noise ratio after beamforming was obviously enhanced, and the signal could be clearly shown. The energy from this explosion was mainly concentrated in the 1 -8Hz range from f-k analysis. The velocity spectrum gave clear positions of event phases, which could not be seen in the original weak signals. The maximum energy distribution obtained by the Beaman method is close to the theoretical value in the azimuth-slowness domain.

Experimental evaluation on well pattern adaptability of ultra-low permeability reservoir using sandstone flat model

As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous flow characteristics,the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models' well pattern adaptability.Through experiments,the models' pressure distribution is measured and on which basis,the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region,non-linear porous flow region,and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve.The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability,while the worst is inverted nine-spot equilateral well pattern.With the increase of drawdown pressure,dead oil region decreases,pressure sweep efficiency and deliverability index increase; meantime,the deliverability index of rectangular well pattern has much more rational increase.Under the same drawdown pressure,the rectangular well pattern has the largest pressure sweep efficiency.