某石英砂矿地下开采保安矿柱稳定性分析

某石英砂矿由于受到产品销售问题及周围环境条件的限制，决定采用地下开采方式。矿体南西部已经靠近矿界，为了保证矿体开采过程中的安全，需要在靠近矿界的矿段预留保安矿柱。因此，采用FLAC3D数值模拟软件，对矿体开采留设不同厚度的保安矿柱进行安全稳定性分析及比较，最终确定留设保安矿柱的合理尺寸。     

Flotation and adsorption of a new collector α-Bromodecanoic acid on quartz surface

A new type collector α-Bromodecanoic acid (CH₃(CH₂)₇CHBrCOOH, α-BDA) was synthesized by solvent-free method (Hell–Volhard–Zelinski reaction) in laboratory for the flotation of quartz mineral at a relatively low temperature of 16 °C. The adsorption mechanism of α-BDA collector on quartz mineral surface was established by zeta potential measurements, contact angle measurements, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS), in conjunction with the results of quartz micro-flotation tests. The flotation results showed that the activator Ca(II) functioned as an indispensable and crucial factor on the recovery of pure quartz. When the quartz was floated with α-BDA alone at strong alkaline conditions (pH ⩾ 11.50), the recovery rate reached to only 11.9%. However, when using the activator Ca(II) at a concentration of 4 × 10⁻⁴ mol/L, the collector exhibited an excellent performance, where about 99.5% of the quartz had been floated at or above pH value 11.50 at 16 °C. The study revealed that the α-BDA collector had adsorbed on the surface of pure quartz in the forms of electrostatic interaction, hydrogen bonding and chemical adsorption based on the results of zeta potential measurements, contact angle measurements, FT-IR spectra, and XPS.     

AT切石英晶体频率力敏特性的实验研究

研究了石英晶体谐振器的力敏特征及晶体的活力与晶片的外形结构、电极尺寸、激励电平、振动模式的关系。实验表明，沿厚度方向剪切振动的AT切石英晶体谐振器的频率力敏特性与激励电平及电极大小无关，泛音振动下的频率力敏特性的增加与泛音次数的增加不成严格的倍数关系，晶体的活力与晶体外形、谐振频率及受力无关。     

新型液体中双调制式石英晶体传感器系统的研制

传统的调频式石英晶体传感器无法区分引起频率变化的两种不同负载效应，介绍一种新型液体中双调制式石英晶体传感器系统，讨论了传感器谐振电路、液体测头结构及采集系统的设计。实验表明，该传感器在液体中３个小时频率稳定度达到±５Ｈｚ，幅值达到±２．５ｍＶ，液体的高度对传感器输出基本没有影响。     

薄型石英晶体半波片的制造

介绍薄型石英晶体半波片的平面和侧面加工。     

差动石英谐振式力传感器的温度特性及其温度自测

推导出了差动石英谐振式力传感器的一种输出表达式，考虑温度的影响进一步得到了温度影响下的传感器输出特性。并找到了一种新的温度自测方法——差动式温度自测法。结果表明：选择较高的泛音次数、合适的作用力方位，能够提高传感器的测力灵敏度，可使其达到单敏感型传感器的4．1倍；温度是影响传感器输出特性的一个主要因素，温度越高，影响越大，必须对输出特性进行补偿。选择合适的泛音次数、作用力方位能提高温度自测的灵敏度，可使其达到双频温度自测的2，7倍。     

Adsorption of disulfide-modified polyacrylamides to gold and silver surfaces as cushions for polymer-supported lipid bilayers

Inclusion of a polymer cushion between a lipid bilayer membrane and solid surface has been suggested as a means to provide a soft, deformable layer that will allow for transmembrane protein insertion and mobility. In this study, we evaluate the properties of a disulfide- and lipid-modified polyacrylamide polymer cushion. High molecular weight random copolymers with various degrees of disulfide and lipid substitution were synthesized. X-ray photoelectron spectroscopy (XPS) was used to determine quantitatively the percentage of disulfide groups bound to gold and silver surfaces. A quartz crystal microbalance with dissipation (QCM-D) was used to study the adsorption process and resulting film properties in situ. The presence of backbone-surface interactions leads to a competition between physisorption of the acrylamide backbone and chemisorption of the disulfide side-chains. This competition limits the degree of chemisorption to gold and silver surfaces. For a polyacrylamide with 10 mol% disulfide side-chains, 78% of the side-chains covalently bind to silver and only 41% bind to gold. The undesired physisorption of the acrylamide backbone leads to adsorption of the homopolymer itself. In addition, film thicknesses, as indicated by both XPS and QCM-D, are limited to 15-30 Å. The QCM-D results for all films indicate the formation of relatively rigid films, rather than the soft, deformable films desired for a lipid membrane polymer cushion.     

基于SVM的花岗岩薄片图像石英分割方法研究

花岗岩薄片不同矿物成分在图像中可能存在相同灰度分布甚至相似纹理。通过结合正交偏光镜镜下图片干涉色信息和单偏光镜图片信息分析,提高了花岗岩薄片石英分割的准确率。方法是从单偏光镜和正交偏光镜下图片中提取图像块的特征信息,运用支持向量机分类方法对图像块进行分类,在分类为石英的图像块中选取种子,再根据两张图片信息,用区域生长方法完成石英分割。该方法实现了自动化分割,分割准确率高,实验证明该方法切实可行。     

光纤电压传感器传感头的设计

基于逆压电效应原理，介绍了光纤电压传感器的工作原理，提出了一种全新的传感头设计方案，为光纤电压传感器测量高电压提出了理论依据。     

Immersion‐Angle Dependence of the Resonant‐Frequency Shift of a Quartz Crystal Microbalance in Three Types of Newtonian Liquids

Abstract

The present work reports the new characteristics of the immersion‐angle dependence of the resonant‐frequency shift (ΔF) of the one‐face sealed quartz crystal microbalance (QCM) in three types of Newtonian liquids, i.e., sucrose, glucose, and glycerol solutions. Below some 1.80×10^?2 g cm^?2 · s^?1/2, the ΔF values are dependent on the immersion angles in all solutions. However, we have found that the transition phenomenon of ΔF occurs between 1.78×10^?2 and 4.80×10^?2 g · cm^?2 · s^?1/2 in the sucrose solution, between 1.75×10^?2 and 4.34×10^?2 g · cm^?2 · s^?1/2 in the glucose solution and between 1.83×10^?2 and 3.03×10^?2 g · cm^?2 · s^?1/2 in the glycerol solution, respectively. Moreover, above the concentrations of the end points of the transition phenomenon, the ΔF values of the sucrose solution are equal to those of 90° at all immersion angles. On the other hand, those of the glucose and the glycerol solutions are the same as those of 30°. This difference may be caused by inherent characteristics of adsorption to the surface of the QCM electrode.