A feasibility study simulating superconducting magnetic separators for weakly-magnetic ores

A “straight-wire” flow-through magnetic ore separator has been designed, built, and successfully used to separate magnetite from synthetic slurries. The purpose of these experiments was to simulate the field profile of a “straight-wire” superconducting magnetic separator which would be capable of separating weakly-magnetic hematite ore from typical slurries. Magnetite is used as the test mineral because it experiences the same magnetic forces at low field as does hematite at high field; thereby making possible less expensive low-field simulation.The present separator concept is based on the fact that there is a particle concentration profile due to the gravity field for low-velocity turbulent flow. When an upward magnetic force is applied, the concentration profile of magnetic particles can be reversed leaving the nonmagnetic particles flowing alone at the bottom of the channel. By means of a divider at the end of the channel, the concentrate is separated from the tailings. It is shown that the time needed to deflect hematite particles in a narrow cylindrical channel concentric with the superconducting wire is small enough so that high throughputs in the turbulent flow region are possible. In the case of a high-field superconducting separator, the centrifugal force could replace gravity by rotating the flow around a straight-wire conductor.     

激电找矿在拾金坡矿区的试验研究

应用激发极化法 (简称激电 )查明拾金坡矿区优选区内主要脉体的含矿性 ,含金石英脉体的走向和深部的产状 ,为布置钻探工程提供依据     

材料复合桩的现场承载性能试验研究

基于水平荷载作用下桩基的弯矩沿深度呈由上向下骤减的规律,将桩的上部设计为抗弯性能良好的钢管桩而下部为抗弯性能较弱的PHC桩,并选择适当的部位通过焊接等方式连接两种桩型。在现场进行锤击试验、水平承载力试验和连接部位抗弯性能试验,将复合桩的压应力、拉应力和水平承载力与材料允许值对比比较。结果表明,所选择的材料复合型桩充分发挥了材料性能,尤其在水平承载力方面表现突出,且不同材料桩型连接部位性能良好。试验结果为桩基的改进提供了新思路和试验依据。     

井地电法点电源供电地表异常电场分布特征实验研究

井地电法供电点位置与地表电位分布关系密切。为研究点电源供电时供电点位于电性异常层上、下不同位置时地表电位的分布特征,通过物理模型研究的方法,采用铜圆柱体作为固定的点电源供电,利用有机玻璃模拟高阻体,通过三维电位观测系统,获得高阻体位于供电源上、下不同深度时水面测得的电位值,计算该值与无异常体存在所测得的背景场电位值的差值作为异常电场,进一步分析异常电场的特征,推断异常体的空间展布情况。模拟实验表明,点源供电时供电点与异常体越近,其地表异常电位值越高,并且供电点源位于异常体下方时其在地表的异常形态越接近其真实形态。     

Effect of magnetic permeability in induction logging

Due to the fact that the quasi-stationary electromagnetic fields applied in induction logging depend on the specific electrical conductivity and magnetic permeability (μ) of the medium, it was of interest to study the effect of μ on induction logging data. A preliminary discussion is presented of certain peculiarities of the μ-effect in a homogeneous conductive medium and the analysis of results concerning two cases: 1) Drilling mud with an increased magnetic susceptibility (e.g., because of the addition of magnetite to increase the weight of the mud); and 2) the rocks studied had an increased magnetic susceptibility (the induction logging of certain ore deposits). The analysis results, which are based on the calculation of an electromagnetic field located at the well axis in the absence of any mud penetration into the layer, are tabulated. —Petroleum Abstracts.     

Sources of the global magnetic field of the Sun

Data on the global magnetic field (GMF) of the Sun as a star for 1968–1999 are used to determine the correlation of the GMF with the radial component of the interplanetary magnetic field (IMF) |B _r|; all data were averaged over a half year. The time variations in the GMF |H| are better correlated with variations in |B _r|; than the results of extrapolating the field from the “source surface” to the Earth’s orbit in a potential model based on magnetic synoptic maps of the photosphere. Possible origins for the higher correlation between the GMF and IMF are discussed. For both the GMF and IMF, the source surface actually corresponds to the quiet photosphere—i.e., background fields and coronal holes—rather than to a spherical surface artificially placed ≈2.5 R _⊙ from the center of the Sun, as assumed in potential models (R _⊙ is the solar radius). The mean effective strength of the photospheric field is about 1.9 G. There is a nearly linear dependence between |H| and |B _r|. The strong correlation between variations in |H| and |B _r| casts doubt on the validity of correcting solar magnetic fields using the so-called “saturation” factor δ^?1 (for magnetograph measurements in the λ 525.0 nm FeI line).     

Quasi-biennial oscillations of the global solar magnetic field

Quasi-biennial oscillations (QBOs) can clearly be distinguished in uniform series of data on the solar magnetic-field polarity derived from Hα observations in 1915–1999. These have been proven to represent oscillations of the global magnetic field of the Sun. This is verified by spectral analyses executed using various methods: the QBOs are clearly visible in low harmonics (l=1–3), but abruptly disappear for l=4 and higher. First and foremost, the QBOs are displayed in variations of the sector structure of the large-scale magnetic field, demonstrating that they correspond to variations of the horizontal multipoles.     

人工振动场源下的被动源面波试验研究

传统的被动源面波测量过程中,因环境噪声过于均衡安静,造成高频信息缺失。为拓宽被动源面波信号的频带范围,在被动源面波连续测量过程中加载人工振动震源,具体采用直线排列的方式对马路边、废弃工厂内两个不同噪音水平的区域进行连续16 min的野外数据采集,人为地控制马路上、废弃工厂内的车辆进出等方式来观测不同噪音水平的面波数据,并对采集的数据分别应用空间自相关法（SPAC/ESPAC）进行分析。结果显示:相同位置同样的观测方式下,有车辆经过相比安静环境下采集的数据,面波频散曲线高频信息显著增加,因此,在通过人工加载振动震源的情况下,能够拓宽被动源面波的高频信息,提升浅部地层分辨率,此具有重要应用价值。      

井地电法地表电场分布规律模型试验研究

为研究井地电法在确定异常体边界时电场的分布规律,笔者对室内水槽固定位置的低阻体(铜板)直接供电,并对充电低阻体形成的电场在地表的电位分布特征进行观测。研究不同方向电位分布特征,及进行线性拟合建立电位梯度曲线,分析异常体不同方向上的电位梯度变化规律,确定该低阻体的边界特征。模拟实验表明,电位梯度曲线在异常体的边界会出现明显的拐点,与电位分布图的对比表明,电位梯度曲线在异常体边界的变化可以作为识别异常体边界的标志。     

A study on the various types of arrhythmias in relation to the polarity reversal of the solar magnetic field

Over the last few years, various researches have reached the conclusion that cosmic ray variations and geomagnetic disturbances are related to the condition of the human physiological state. In this study, medical data concerning the number of incidents of different types of cardiac arrhythmias for the time period 1983–1992, which refer to 1902 patients in Tbilisi, Georgia, were used. The smoothing method and the Pearson r-coefficients were used to examine the possible effect of different solar and geomagnetic activity parameters and cosmic ray intensity variations on the different types of arrhythmias. The time interval under examination was separated into two different time periods, which coincided with the polarity reversal of the solar magnetic field occurred in the years 1989–1990, and as a result, a different behavior of all the above-mentioned parameters as well as of the different types of arrhythmias was noticed during the two time intervals. In addition, changing of polarity sign of the solar magnetic field was found to affect the sign of correlation between the incidence of arrhythmias and the aforementioned parameters. The primary and secondary maxima observed in the solar parameters during the solar cycle 22, also appeared in several types of arrhythmias with a time lag of about 5 months.     

The magnetic field of the pulsating subdwarf Balloon 090100001

We have analyzed polarization observations of the subdwarf Bal 09, which is one of a group of hybrid sdB stars that display simultaneously both short- and long-period pulsations. Certain properties previously unknown for subdwarfs have been established for Bal 09, such as variations of the pulsation amplitude of the main oscillation mode, rotational splitting of multiplets, and variations of this splitting. Information about the stellar magnetic field must be considered if we wish to explain these properties. New observational data enabling estimation of the longitudinal magnetic field of Bal 09 have been obtained on the main stellar spectrograph of the 6-m telescope of the Special Astrophysical Observatory. Studies of the longitudinal component of the magnetic field 〈B _z 〉 were carried out using a regression analysis. This method simultaneously yields estimates of the uncertainty in 〈B _z 〉. Test measurements of 〈B _z 〉 were carried out using the same method. For the star HD 158974, which has zero total magnetic field, the estimated longitudinal magnetic field is 〈B _z 〉 = −4 ± 5 G. The standard magnetic field for the Ap star α ²CVn was measured to be −363 ± 17 G, in very good agreement with measurements in the literature. The estimated longitudinal magnetic field for Bal 09 is 34 ± 63G—appreciably lower than values established earlier for six subdwarfs, ≈1.5 kG. The results of the regression analysis for both individual spectral subranges and for intervals containing characteristic spectral features did not indicate reliable detections of a magnetic field exceeding the uncertainties in 〈B _z 〉. The uncertainty in 〈B _z 〉, which was 60–80 G for the entire spectral range and 140–200 G for selected spectral intervals, leads to an estimated upper limit on the longitudinal magnetic field 〈B _z 〉 for Bal 09. This estimate for 〈B _z 〉 can place observational constraints on theoretical explanations for the amplitude variations of the pulsations, rotational splitting of multiplets, and possible variations of the internal structure of the star.     

不同加载速率下岩石变形场演化试验研究

开展不同加载速率条件下岩石变形场演化特征的试验研究,对岩石安全施工及岩石工程灾害预测预警等具有重要意义。通过不同加载速率下红砂岩单轴压缩试验,在以数字散斑相关方法分析试件变形场的基础上,对加载速率与岩石变形局部化演化特征、泊松比变化及能量积累和释放特征的对应关系进行分析。结果表明:随着加载速率的增加,岩石试件的峰值强度及脆性呈增加趋势。加载速率越大岩石试件的变形局部化启动应力越接近强度峰值,且变形局部化启动时对应的应力量值总体上呈增加的趋势。在不同量级加载速率下岩石试件泊松比量值差别明显,总体趋势表现为:在岩石试件变形局部化启动前,随着加载速率增加,岩石试件泊松比减小;在岩石试件变形局部化阶段,随着加载速率增加,岩石试件泊松比增大。在能量积累阶段,岩石试件最大变形能密度随加载速率增加而增大;在能量释放过程中,岩石试件能量释放速率随着加载速率增加而增大。     

Modeling the generation of the magnetic field in NGC 5775

A model for the generation of large-scale magnetic fields is constructed for the galaxy NGC 5775, in which the magnetic field has the form of a dipolar dynamo wave propagating along the galactic disk. The excitation of such a mode, which is unusual for galactic dynamos, can be explained by the strong variation of the galactic rotation with height above the plane of symmetry of the galactic disk.     

The signature of the interplanetary magnetic field components on the low latitude geomagnetic field disturbance

The signature of the interplanetary magnetic field componentB _y andB _z and their effects on the low lattitude field are studied for Alibag station. It has been found that the direction and magnitude of theB _y component of IMF have their signatures on the low latitude geomagnetic field, varying with the time of the day and season.     

地质力学磁力模型试验中均匀梯度磁场的构建

地质力学磁力模型试验利用电磁力（场）模拟重力（场）的原理研究地质力学工程问题,采用的相似材料由铁磁材料与岩土体混合而成。铁磁材料在磁场中的受力方向和大小与所处空间的磁通密度梯度的大小和方向有关,为了模拟均匀的重力场,需要得到在一定空间范围内磁通密度梯度大小相同、方向单一的磁场。根据电磁学基本原理,构建了3种磁路形式以获得磁通密度梯度相对均匀的磁场,对磁力模型试验相似材料进行加载。对比3种磁路,在最佳试验区内开放式磁路对磁场的利用率更高,所以在电流相同条件下等到的磁通密度梯度的量值也更大。与另两种磁路形式相比,尽管半开放式磁路在重量和工作效率上的性能不及开放式和封闭式磁路,但其最佳试验空间的磁通密度梯度的均匀性最好,误差在5%以内,半开放式磁路可以作为地质力学磁力模型试验的磁场发生装置。     

冻土未冻水含量的低场核磁共振试验研究

采用低场核磁共振技术测试了冻融循环过程中不同土质、不同NaCl离子浓度饱和试样的未冻水含量,结合T2分布曲线从微细观角度分析了冻融过程中未冻水在孔隙赋存分布情况。试验结果表明：冻结过程可分为过冷度段、快速下降段、稳定段3个阶段,而融化过程仅存在稳定段、快速融化段,并不存在与过冷现象对应的过热现象。冻结时大孔隙的水首先冻结,而融化时孔隙水的增加却是从小孔隙开始的,这是由水分热动力学势能的差异导致孔隙水冻结和融化在时间上的有序性。并且分析了冻融循环中土质类型、离子浓度对未冻水含量的影响,以及探讨了冻融过程出现的滞后现象的原因。     

Parameters of the turbulent magnetic field in the solar photosphere: Power spectrum of the line-of-sight field

Ground-based (Big Bear Solar Observatory) and extra-atmospheric (SOHO/MDI) measurements of the photospheric line-of-sight magnetic field of one active and two quiet regions are used to calculate power spectra of the field, taking into account the characteristic function for the diffraction limit of the telescope resolution. At high frequencies, the physically meaningful linear interval in the spectrum extends to a wave number of k=4.6 Mm^?1 (spatial scale l=1.4 Mm) for the quiet regions and k=3.35 Mm^?1 (l=1.9 Mm) for the active region. A high-frequency spectral break at k≥3 Mm^?1 is associated with the characteristic telescope function; the position of the break and the spectral slope beyond the break do not reflect the turbulent state of the field. As the field recording improves, the break shifts toward higher frequencies. The spectral indices in the physically meaningful linear interval are substantially different for the active and quiet regions: in the active region (NOAA 8375), the spectrum behaves as E(k)≈k ^?1.7 (very close to the Kolmogorov index, ?5/3) in the interval 0.78≤k≤3.35 Mm^?1, while in the quiet regions E(k)≈k ^?1.3 for 0.77≤k≤4.57 Mm^?1. This difference can be explained by the additional effect of a small-scale turbulent dynamo in the unperturbed photosphere. In this case, this mechanism can generate at least 6% of the magnetic energy of the photospheric line-of-sight field in quiet regions.     

基于PNI磁感式传感器的钻孔测斜仪的研制

研制了一款基于PNI磁感式传感器和SCAl00T加速度传感器的矿用全空间钻孔测斜仪。详细论述了系统的总体结构、测量原理及传感器的电路设计;同时分析了系统的误差及其来源,给出了误差补偿模型及其补偿、标定的方法。实验结果表明：该钻孔测斜仪具有体积小、精度高、可靠性高等特点,满足工程的需要。     

Coherent structures in the dynamics of the large-scale solar magnetic field

Variations in the mean solar magnetic field (MSMF) are studied in both the frequency-time and longitude-time domains. A wavelet analysis of the MSMF clearly demonstrates that variations in the mean field are not stationary. Combined with longitude-time diagrams for the background solar magnetic field (BSMF), the analysis reveals the emergence of the background field, which occurs discretely at intervals of 1.5–2 years. Based on an analysis of the fine structure in MSMF variations, we develop a numerical technique to study timedependent heliographic-longitude distribution of the large-scale magnetic field. A detailed picture of the rotation of the large-scale magnetic field is derived for activity cycles 20–23. Coherent structures are detected in longitude-time diagrams obtained by deconvolving the MSMF series. These structures are related to discrete rigid-rotation modes of the large-scale magnetic fields. Various rotational modes coexist and replace one another. During the phase of activity growth, modes with periods of 27.8–28.5 days dominate, whereas a mode with a rotational period of about 27 days dominates during the decline phase. Occasionally, modes with periods of 29–30 days appear. Most structures in the longitude-time MSMF distribution correspond to similar structures in the BSMF distribution for the northern or southern hemisphere. Chronologically, the emergence of the BSMF has frequently been accompanied by changes in the solar rotational regime and has been correlated with variations in the polarity asymmetry in the course of the 11-year activity cycle.     

岩石圆孔结构破坏过程变形场演化的实验研究

采用自行设计的岩石材料破坏过程变形场监测系统(Geo-DSCM系统),观测了受单轴压缩的岩石圆孔结构破坏过程中的变形场演化。圆孔结构由大理岩方板在中心钻孔加工而成,以0.02 mm/min的位移加载速度进行单轴压缩至破坏。实验结果表明,载荷水平较低时圆孔结构的拉应力集中部位发生变形集中现象;当载荷水平接近加载曲线的峰值点时,变形集中在两条共轭的与加载方向成一定角度的局部化带上;之后,变形的集中迁移到其中一条带上集中,结构最终在此带上形成宏观裂纹而破坏。