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1.
预测矿井涌水量的计算级别与精度评述 总被引：5，自引：0，他引：5
根据水利部2005年发布的《建设项目水资源论证导则（试行）》技术文件中的有关规定与要求,参照《供水水文地质勘察规范》以及《固体矿产资源/储量分类,》认为地下水可开采量与预测矿井涌水量的计算可按勘查研究程度,将其可分为A、B、C、D、E等5个精度等级。参照各级别的允许误差,论证了目前矿井涌水量预测计算公式及方法的可靠程度。 相似文献
2.
We show that the non-radial field-boundary condition (or the line-of-sight boundary condition) for the Laplacian-like equation developed by Bogdan and Low (1986) is sufficient to uniquely determine the model coronal magnetic field provided the electric currents are horizontal (or zero, the current-free case) at the solar surface as well as in the solar atmosphere between the photosphere and the source surface. The derived recursion formulae for the spherical harmonic coefficients can be used to determine the spherical harmonic coefficients in the solutions of the horizontal current models very efficiently. 相似文献
3.
石膏喀斯特陷落柱的形成及其水文地质意义 总被引：10，自引：1，他引：9
华北地区,石炭二叠纪地层内有陷落柱分布,这种现象在世界其它地区是少见的。山西省太原、霍县和阳泉煤田陷落柱最为发育,每平方公里一般有陷落柱0.5—5个。陷落柱横断面一般呈圆形或椭圆形,直径20—200米,高50—500米,由上覆岩层坠落的碎石、砂和土所充填。 自1944年以来,地质学家和水文地质学家普遍认为陷落柱是奥陶系石灰岩溶洞坍陷的产物。这种假说对野外一些地质现象难以解释。作者论证陷落柱形成的过程是:在地下深处,中奥陶系石灰岩中赋存有很厚的硬石膏。地壳不断上升,在地下水的作用下,硬石膏水化变成石膏。体积膨胀了64％的石膏,沿着破碎带的交线挤入上覆的岩层。这种柱状的石膏体不断被地下水溶蚀,上覆岩层塌陷填充形成了陷落柱。 陷落柱除对采矿有影响外,对喀斯特大泉补给、矿坑充水、地下水的人工补给等方面都有重要的意义。 相似文献
4.
太行期岩溶剥蚀面的发现及地文期的划分 总被引：8，自引：2，他引：6
<正> 华北地区的山地,在燕山运动以后,没有经历剧烈的造山运动,基本是同步振荡式地上升。区域地形发展的历史表现为剥蚀期与堆积期的交替出现,形成了华北山地十分醒目的多层地形—多级山地剥蚀面与多级河流阶地。由于地质年代久远,在华北地区,古老的剥蚀面很少保留下来。因此,对唐县期以前的地文期论述较少。1980年,笔者在平顺县赵城附近找到了完整的岩溶剥蚀面。既而进行了一些测绘、钻探和孢粉鉴定等工作。我们认为,这项工作的成果,对华北地文期和岩溶发育历史的划分都是有意义的。 相似文献
5.
When globally mapping the observed photospheric magnetic field into the corona, the interaction of the solar wind and magnetic
field has been treated either by imposing source surface boundary conditions that tacitly require volume currents outside
the source surface (Schatten, Wilcox, and Ness, 1969) or by limiting the interaction to thin current sheets between oppositely
directed field regions (Wolfson, 1985). Yet observations and numerical MHD calculations suggest the presence of non-force-free
volume currents throughout the corona as well as thin current sheets in the neighborhoods of the interfaces between closed
and open field lines or between oppositely directed open field lines surrounding coronal helmet-streamer structures. This
work presents a model including both horizontal volume currents and streamer sheet currents. The present model builds on the
magnetostatic equilibria developed by Bogdan and Low (1986) and the current-sheet modeling technique developed by Schatten
(1971). The calculation uses synoptic charts of the line-of-sight component of the photospheric magnetic field measured at
the Wilcox Solar Observatory. Comparison of an MHD model with the calculated model results for the case of a dipole field
and comparison of eclipse observations with calculations for CR 1647 (near solar minimum) show that this horizontal current-current-sheet
model reproduces polar plumes and axes of corona streamers better than the source-surface model and reproduces coronal helmet
structures better than the current-sheet model. 相似文献
6.
Bin Gui Chenglong Shen Yuming Wang Pinzhong Ye Jiajia Liu Shui Wang Xuepu Zhao 《Solar physics》2011,271(1-2):111-139
In this paper, ten CME events viewed by the STEREO twin spacecraft are analyzed to study the deflections of CMEs during their propagation in the corona. Based on the three-dimensional information of the CMEs derived by the graduated cylindrical shell (GCS) model (Thernisien, Howard, and Vourlidas in Astrophys. J. 652, 1305, 2006), it is found that the propagation directions of eight CMEs had changed. By applying the theoretical method proposed by Shen et?al. (Solar Phys. 269, 389, 2011) to all the CMEs, we found that the deflections are consistent, in strength and direction, with the gradient of the magnetic energy density. There is a positive correlation between the deflection rate and the strength of the magnetic energy density gradient and a weak anti-correlation between the deflection rate and the CME speed. Our results suggest that the deflections of CMEs are mainly controlled by the background magnetic field and can be quantitatively described by the magnetic energy density gradient (MEDG) model. 相似文献
7.
Most work on coronal mass ejection (CME) interpretation focuses on the involved active region rather than on the large-scale coronal context. In this paper a global potential-field source-surface model of the coronal magnetic field is used to evaluate the sensitivity of the coronal field configuration to the location, orientation, and strength of a bipolar active region relative to a background polar field distribution. The results suggest that the introduction of antiparallel components between the field of the active region and the background field can cause significant topological changes in the large-scale coronal magnetic field resembling observations during some simple CMEs. Antiparallel components can be introduced in the real corona by the diffusion and convection of photospheric fields, flux emergence, or erupted or shear-induced twist of active-region fields. Global MHD models with time-dependent boundary conditions could easily test the stability of such configurations and the nature of any related transients. 相似文献
8.
卤水勘查规范编写组李博昀等6人撰文“试论现行盐湖卤水矿勘查规范的适用性——兼与钱学溥先生商榷”(李博昀等, 2023), 认为,“现行卤水勘查规范,总体是一部适用的规范,没有发现大的问题”。然而,笔者认为,规范编写组把卤水视为固体矿产,要求依照固体矿产勘查的方法,按工程网度施工几十个、几百个地质孔以确定卤水的地质储量,是极端错误的。执行现行卤水勘查规范,造成了重大的经济损失,扼杀了深层卤水的开发。目前,这个彻头彻尾错误的规范,迫切需要进行修订。本人提出了一个《卤水矿产地质勘查纲要》,供修订该规范参考。 相似文献
9.
地震电磁辐射脉冲计数的异常判别 总被引：1，自引：0，他引：1
对山西省地震局研制的ＤＷＭＪ－８９Ａ（Ｂ）型电磁波微计算机脉冲记录仪１０多年的实验结果进行了分析，得出凡属震源辐射出的前兆电磁信息为显著的阵发性簇状脉冲且呈随机分布，而自然界或人工干扰则是量值近乎相等的有规律分丰分布的结论。 相似文献
10.
Shutter noise induces a small random shift of the zero point in full-disk magnetograms obtained by the Michelson Doppler Imager
(MDI) instrument aboard SOHO. In this paper, we develop a method to remove this offset by fitting the distribution of the
magnetic field strength with a Gaussian function (Ulrich et al., 2002). We also discover a systematic error in the five-minute magnetograms that are the sum of five individual magnetograms
computed on-board; this error can be removed together with the offset. The mean solar magnetic field and synoptic frames derived
from corrected magnetograms show significant improvement. Standard synoptic charts benefit from reduced noise and elimination
of systematic errors in the individual magnetograms. This indicates that this correction is effective and necessary. 相似文献