东乡铜矿区构造特征与成矿的关系

本文针对东乡铜矿区构造特征的分析,尤其是对矿区北东向断层,含矿破碎带及横跨褶皱的深入探讨,结合地史背景阐明构造的产生、演化及对成矿的关系,并指出其找矿意义。     

Advances in healing-on-demand polymers and polymer composites

Healing-on-demand materials exhibit the capability to close cracks and heal the closed/narrowed cracks when needed and to recover functionality using intrinsic or extrinsic resources. In this paper, advances in healing-on-demand polymers and polymer composites in the past decade are reviewed, covering different schemes and technologies used to trigger crack closure and to heal molecularly. A balanced review on non-load-bearing polymers and polymer composites as well as load-carrying polymers and polymer composites is presented. The progress in self-healing polymers and polymer composites has been well discussed recently in the literatures. In this review, therefore, less attention has been paid on what has been widely reported; we primarily focus on healing-on-demand materials concerned with large volume damage healing by a close-then-heal (CTH) strategy. The healing-on-demand material by the CTH approach undergoes a process of crack closure, followed by crack healing with healing agents. Healing theories, including those within the continuum damage mechanics framework, and healing efficiency evaluations are also reviewed. Perspectives on future development in this emerging research area are discussed.     

In-vitro behavior of different fully dense calcium phosphate materials fabricated by Spark Plasma Sintering

Results obtained during in-vitro experiments concerning human osteoblasts cultivated on the surface of dense samples produced by Spark Plasma Sintering from three types of hydroxyapatite powders are described and discussed. The sintered products display diverse composition and microstructures which are found to significantly influence the biological response of the cells. Osteoblasts adhesion, viability and proliferation are quantitatively comparable for the three classes of bioceramics, whereas matrix mineralization occurs only in products exclusively consisting of hydroxyapatite. Correspondingly, a calcium-phosphate layer exhibiting a trabecular-like microstructure is deposited on the materials surface. Matrix mineralization is favored when the substrate is composed of submicrometer-sized apatite grains. On the other hand, the latter phenomena is markedly suppressed, and so does the formation of the new apatite phase, when cells are seeded on sintered disks composed of β-Tri-Calcium Phosphate, which was formed during the sintering process from the decomposition of initial apatite.     

气动肌肉驱动仿生关节的理论分析

根据气动肌肉的简化模型,通过引入关节的刚度和力矩-压力系数等概念,建立了由一对对抗性气动肌肉驱动仿生关节的理论模型.研究了关节的刚度和位置独立控制时对气动肌肉输入压力的要求,并对气动肌肉驱动关节运动时的几种压力变化方式进行了分析.研究表明,两个气动肌肉的压力的不同变化方式对于关节动态的刚度、转矩有很大的影响.     

Decolorization of methylene blue by heterogeneous Fenton reaction using Fe3−xTixO4 (0 ≤ x ≤ 0.78) at neutral pH values

In this work, a series of Fe_3−xTi_xO₄ (0 ≤ x ≤ 0.78) was synthesized using a new soft chemical method. The synthetic Fe_3−xTi_xO₄ were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Mössbauer spectroscopy, thermogravimetric and differential scanning calorimetry (TG–DSC) analyses. The results showed that they were spinel structures and Ti was introduced into their structures.Then, decolorization of methylene blue (MB) by Fe_3−xTi_xO₄ in the presence of H₂O₂ at neutral pH values was studied using UV–vis spectra, dissolved organic carbon (DOC) and element C analyses. Furthermore, the degradation products remained in reaction solution after the decolorization were identified using ionic chromatography (IC), ¹³C nuclear magnetic resonance spectra (NMR), liquid chromatography and mass spectrometry (LC–MS). Although small amounts of MB were mineralized, the aromatic rings in MB were destroyed completely after the decolorization. Decolorization of MB by Fe_3−xTi_xO₄ in the presence of H₂O₂ was promoted remarkably with the increase of Ti content in Fe_3−xTi_xO₄ due to the enhancement of both adsorption and degradation of MB on Fe_3−xTi_xO₄.     

Synthesis and characterization of hydrophobic calcium carbonate particles via a dodecanoic acid inducing process

A carbonation route for the synthesis of hydrophobic calcium carbonate was studied. In the process, dodecanoic acid was used as an organic substrate to induce the nucleation and growth of calcium carbonate. The calcium carbonate particles were produced by means of carbonation of the mixture of calcium hydroxide and dodecanoic acid by bubbling CO₂/N₂ gas mixture. The operating parameters such as temperature and the concentration of the organic substrate were varied to study their influences on the active ratio and contact angle of calcium carbonate particles. The morphology of the calcium carbonate particles was characterized with scanning electron microscopy (SEM). The synthesized calcium carbonate particles in the presence of the organic substrate are rod-like and ellipse-like particles. The polymorphs were characterized with X-ray diffraction (XRD).     

Solar photocatalytic degradation of reactive blue 4 using a Fresnel lens

The heterogeneous photocatalytic degradation of reactive blue 4 dye (RB4) solutions under Fenton reagent and TiO(2) assisted by concentrated solar light irradiation using a Fresnel lens has been studied. Multivariate experimental design was applied to study the kinetic process. The efficiency of photocatalytic degradation was determined from the analysis of color and total organic carbon (TOC) removal. Factorial experimental design allowed to determine the influence of four parameters (pH and initial concentrations of TiO(2), Fe(II) and H(2)O(2)) on the value of the decoloration kinetic rate constant. Experimental data were fitted using neural networks (NNs). The mathematical model reproduces experimental data within 86% of confidence and allows the simulation of the process for any value of parameters in the experimental range studied. Also, a measure of the saliency of the input variables was made based upon the connection weights of the neural networks, allowing the analysis of the relative relevance of each variable with respect to the others. Results showed that acidic pHs (pH=3.6) are preferred for the complete dye decoloration. The optimum catalyst concentration is 1.2g TiO(2)/l. The use of a low cost catalyst and its activation using a Fresnel lens to concentrate solar energy significantly accelerates the degradation process when compared with direct solar radiation alone and can offer an economical and practical alternative for the destruction of environmental organic compounds.     

Mineralization and biodegradability enhancement of natural organic matter by ozone-VUV in comparison with ozone, VUV, ozone-UV, and UV: Effects of pH and ozone dose

The increase in mineralization and biodegradability of natural organic matter (NOM) by ozone-vacuum ultraviolet (VUV) in comparison with ozone, VUV, ozone-ultraviolet (UV), and UV were investigated. The effects of operating parameters including pH and ozone dose were evaluated. Results showed that the mineralization rate of dissolved organic carbon (DOC) provided by the processes tested was in the following order: ozone-VUV > VUV > ozone-UV > ozone > UV. Among three pH studied (7, 9, and 11), pH 7 provided the highest DOC mineralization rate and biodegradability increase. A synergistic effect was observed when combining ozone with UV or VUV at pH 7 and 9 but not at pH 11. The oxidized NOM samples were separated into six fractions based on polarity (hydrophobic/hydrophilic) and charge (acid/neutral/base) to reveal NOM characteristic changes. Ozone-VUV was effective in mineralizing hydrophobic neutral and acid fractions. The hydrophilic neutral fraction was a major NOM fraction after oxidation (39-87%) and was contributed to by the biodegradable DOC produced during oxidation. High performance size exclusion chromatography results revealed that the combination of UV or VUV with ozone was more effective in the decomposition of high molecular weight compounds than ozone alone.     

西藏尼木县厅宫铜矿床地质特征与成矿机理

厅宫铜矿床矿区位于冈底斯斑岩铜矿带东段,属于雅江缝合带北侧的冈底斯火山—岩浆弧构造带与念青唐古拉构造带的交汇部位,是西藏尼木地区三个大型斑岩铜矿区之一。结合矿区地质特征、矿体特征及矿石特征研究,分析厅宫铜矿床的类型和成矿作用,认为该矿床属斑岩型铜矿床。     

西藏帮浦斑岩—矽卡岩型铜钼铅锌矿床地质特征分析

西藏帮浦铜钼多金属矿床是冈底斯带重要的多金属矿床之一,根据野外调查以及室内分析工作总结,从矿区相关地层、岩浆岩、断裂构造及控矿构造、围岩蚀变等方面分析该矿床地质特征。西藏帮浦矿床属斑岩型—矽卡岩型复合矿床,由斑岩体内接触带细脉浸染型铜钼矿化体和接触带外侧灰岩地层中脉状铜铅锌矿化体构成。中二叠统洛巴堆组地层(P1l)是矿区内的主要赋矿层位。F1断裂是矿区的主要控矿容矿构造。在中新世后碰撞伸展构造环境下,帮浦一带大量的二长花岗斑岩、闪长玢岩侵入及后期构造作用和岩浆期后含矿热液作用是成矿关键。