内蒙古东升庙白垩系红层的近红外光谱分析

在内蒙古东升庙矿区西部采取白垩系红层岩心及地表风化土壤样,用近红外光谱分析技术对各个样品进行测试分析。结果表明,近红外光谱技术能通过矿物中各基团的特征吸收峰快速鉴别出矿物,东升庙矿区西部白垩系红层为泥质胶结主要由石英、长石、蒙脱石、伊利石、绿泥石、白云母等组成,其矿物组成主要受到上游物源区影响;其崩解主要为蒙脱石等粘土矿物吸水膨胀,失水收缩不均匀,使原有裂隙扩大并产生新的裂隙,导致强度降低,发生崩解;根据其粘土矿物的组合推测其风化过程中气候以寒冷干燥为主,风化过程主要为物理风化。研究结果一方面可以完善该矿区地质特征,另一方面表明在矿物光谱学的基础上,近红外光谱分析技术可以有效地分析土壤和岩石的矿物成分,从而论证了近红外光谱分析技术应用于土壤、岩石矿物的的快速分析可行性,表明了其在地质研究中的可行性,为以后的土壤、岩石研究提供新思路。     

A high-order numerical method for the nonlinear Helmholtz equation in multidimensional layered media

We present a novel computational methodology for solving the scalar nonlinear Helmholtz equation (NLH) that governs the propagation of laser light in Kerr dielectrics.     

An XPS analytical approach for elucidating the microbially mediated enargite oxidative dissolution

In this work, the microbe-mediated oxidative dissolution of enargite surfaces (Cu₃AsS₄) was studied on powdered samples exposed to 9K nutrient solution (pH 2.3) inoculated by Acidithiobacillus ferrooxidans initially adapted to arsenopyrite. These conditions simulate the acid mine environment. The redox potential of the inoculated solutions increased up to +0.72 V vs normal hydrogen electrode (NHE), indicating the increase of the Fe³⁺ to Fe²⁺ ratio, and correspondingly the pH decreased to values as low as 1.9. In the sterile 9K control, the redox potential and pH remained constant at +0.52 V NHE and 2.34, respectively. Solution analyses showed that in inoculated medium Cu and As dissolved stoichiometrically with a dissolution rate of about three to five times higher compared to the sterile control. For the first time, X-ray photoelectron spectroscopy (XPS) was carried out on the bioleached enargite powder with the aim of clarifying the role of the microorganisms in the dissolution process. XPS results provide evidence of the formation of a thin oxidized layer on the mineral surface. Nitrogen was also detected on the bioleached surfaces and was attributed to the presence of an extracellular polymer substance layer supporting a mechanism of bacteria attachment via the formation of a biofilm a few nanometers thick, commonly known as nanobiofilm. Figure SEM image of enargite is in the background of the figure; in foreground the scheme of the dissolution mechanism in presence of microorganisms showing a sulphur enriched layer; the mechanism is supported by the presence of the high binding energy signal in the S2p photoelectron spectrum (upper-right).     

MATHEMATICAL ANALYSIS OF THE COLLAPSE IN BOSE-EINSTEIN CONDENSATE

In this article, the authors consider the collapse solutions of Cauchy problem for the nonlinear Schrdinger equation iψt + 1/2 △ψ - 1/2 ω2|x|2ψ + |ψ|2ψ = 0, x ∈ R2, which models the Bose-Einstein condensate with attractive interactions. The authors establish the lower bound of collapse rate as t → T . Furthermore, the L2-concentration property of the radially symmetric collapse solutions is obtained.     

航行体垂直出水载荷与空泡溃灭机理分析

针对航行体水下垂直发射出水载荷机理问题, 首先开展了典型工况全过程的数值 模拟, 得到了航行 体肩、尾空泡及表面压力的演化过程, 并与试验结果进行了对比验证. 在此基础上揭示了航 行体肩部空泡溃灭的过程和机制, 进而提出了出水溃灭压力的物理模型, 探索了空泡厚度、 水层厚度、声速等重要参数的影响, 讨论了试验溃灭压力相似律等相关问题.     

转印头在受压下的塌陷(英文)

可逆粘附是转移印刷中转印头重要的特性,在最近的实验中通过控制接触面实现可逆粘附.通过外加压力控制转印头的塌陷和其与基体的接触面使界面的粘附力达到3个量级的转换.建立的力学模型研究了在外压作用下转印头的塌陷和接触面积,接触面积与外压及长高比的关系对转印头的设计很有帮助.     

基于ZigBee的煤矿井下甲烷浓度检测系统设计

针对传统煤矿井下甲烷浓度采用工业总线检测方法的不灵活和存在盲点等问题,本文提出了一种基于ZigBee的煤矿井下甲烷浓度检测系统。系统采用ZigBee协议栈构建无线传感器通讯网络,该网络的终端节点感知和采集矿井甲烷的浓度,并将浓度数据通过无线传输至协调器,协调器再经过串口传输到地面的监控中心。详细介绍了检测系统的软硬件设计,并对系统进行了测试验证。     

Numerical simulation of rock fragmentation during cutting by conical picks under confining pressure

In this article, the effect of confining pressure on rock fragmentation process during cutting was investigated by numerical simulation with a discrete element method (DEM). Four kinds of sandstones with different physical properties were simulated in the rock cutting models under different confining pressures. The rock fragmentation process, the cutting force, and the specific energy under different confining pressures were analyzed. With the increase in confining pressure and rock strength, the vertical propagation of cracks was restrained. Rock samples were compacted and strengthened by confining pressure resulting in the increase of the cutting force. The specific energy of rock cutting linearly increased with the increase of the confining pressure ratio.     

弹性板水下爆炸冲击载荷的修正虚拟流体方法分析

研究非接触水下爆炸中板结构厚度和密度对冲击载荷和空化演变的影响.将近期发展的修正的虚拟流体方法推广应用于处理可压缩流体与弹性板结构的非线性相互作用.研究发现,假设结构不发生断裂破坏,较小的板厚度或密度可以减弱爆炸波对结构的冲击,冲击载荷随着厚度或密度的增大非线性地趋向于固壁边界下的结果.而且较小的板厚度或密度可以促使空化较早形成,产生较大的空化区,并推迟和减弱空化破裂对结构的二次冲击.     

Geochemical Anomaly Characteristics of Cd in Soils around Abandoned Lime Mines: Evidence from Multiple Technical Methods

Lime mines are a potential source of pollution, and the surrounding soil environment is generally at threat, especially in abandoned lime mines. This paper focuses on the study area in eastern Anhui, attempting to analyze whether Cd enrichment is related to abandoned mines. On the basis of geological investigation, this study systematically used XRD, XRF, GTS and universal Kriging interpolation to determine the distribution law of Cd in the study area, and evaluated the potential ecological risk of Cd. The results showed that the main mineral types of soil samples of red clastic rock soil parent material (RdcPm) and soil samples of carbonate soil parent material (CPm) were not completely the same. Correlation analysis showed that CaO, MgO and Cd were positively correlated with the CPm. Human activities led to the accumulation of Cd in the study area. High Cd was mainly concentrated in the northwest of the study area, which was correlated with abandoned mines and soil parent materials. The study area was dominated by slight potential risks, although some areas had medium potential risks and high potential risks. All potential high risks were in the CPm field. This study provides a scientific basis for the comprehensive utilization and development planning of soil in the study area.