紫金山东南矿段成矿期次、阶段浅析

通过对紫金山东南矿段铜钼(金)矿床地质矿化特征分析,指出铜钼矿化带主要赋存于花岗闪长斑岩的内外接触带,处于似斑状花岗闪长斑岩的上部,金矿化带赋存在表生氧化带的英安玢岩、隐爆角砾岩中。经过对矿石的组构特征、矿物生成顺序等特征分析,将矿床的成矿演化过程分为斑岩热液期、高硫化浅成低温热液期、表生氧化期三个主要矿化期次,进一步将斑岩热液期分为黑云母-钾长石化阶段、石英-绢云母化阶段、碳酸盐化阶段三个阶段;高硫化浅成低温热液期分为地开石化阶段、明矾石化阶段、硅化阶段三个阶段。研究结果为进一步研究矿床成因提供了依据。     

Direct shear behavior of gravel-rubber mixtures: Discrete element modeling and microscopic investigations

In this paper, a newly developed 3-dimentional discrete element model (DEM) for gravel-rubber mixtures (GRMs), namely DEM4GRM, that is capable of accurately describing the macro-scale shear response (from small to large deformation) of GRMs in a direct shear box apparatus is presented. Rigid gravel grains are modelled as simple multi-shape clumps, while soft rubber particles are modeled by using deformable 35-ball body-centered-cubic clusters. Mixtures are prepared with different volumetric rubber content (VRC) at 0, 10, 25, 40 and 100%, statically compressed under 30, 60 and 100 kPa vertical stress and then sheared, by closely simulating a reference laboratory test procedure. The variation of micro-scale factors such as fabric, normal and tangential force anisotropy is carefully examined throughout the shearing process and described by means of novel micro-mechanical relationships valid for GRMs. Moreover, strong-force chains are scrutinized to identify the transition from rigid to soft granular skeleton and gain insights on the load transfer and deformation mechanisms of GRMs. It is shown that the development of the fabric and force anisotropy during shearing is closely related to the macro-scale shear strength of GRMs, and strongly depends on the VRC. Besides, strong-force chains appear to be primarily formed by gravel-gravel contacts (resulting in a rigid-like mechanical behavior) up to VRC = 30%, and by rubber-rubber contacts (causing a soft-like mechanical response) beyond VRC = 60%. Alternatively, at 30% < VRC < 60%, gravel-rubber contacts are predominant in the strong-force network and an intermediate mechanical behavior is observed. This is consistent with the behavioral trends observed in the macro- and micro-mechanical responses.     

Effect of the particle size ratio on macro- and mesoscopic shear characteristics of the geogrid-reinforced rubber and sand mixture interface

As a new type of material for civil engineering projects, the rubber and sand mixture is widely used in roadbed fillers, offering environmental benefits over traditional tyre disposal methods. This study uses a large-scale direct shear apparatus to examine the interface shear properties of the geogrid-reinforced rubber and sand mixture, considering different particle size ratios (r), rubber contents, and normal stresses. Based on indoor tests, direct shear models of the mixture with different values of r are established in PFC^3D, revealing the meso-mechanical mechanism of the mixture in the direct shear process. The results show that when r is greater than 1, incorporating a certain amount of rubber particles can increase the shear strength of the mixture. The r values of 15.78, 7.63, and 3.98 correspond to an optimal rubber content of 30%, 10%, and 20%, respectively. When r is less than 1, mixing rubber particles can only reduce the shear strength of the mixture. When the rubber content is low, the smaller the value of r, the greater is the thickness of the shear band. Furthermore, the normal and tangential contact forces are greater. The fabric anisotropy evolution law of the mixture is consistent with the change in the contact force distribution.     

针织物节能减排漂染工艺探讨

将新开发的高效前处理、染色助剂应用于针织物实用高效漂染工艺,探讨其应用工艺、产品质量及节能减排效果。分析各类前处理碱氧一浴工艺的特点、应用特性及节能减排效果;阐述涤棉针织物练染一浴工艺,免还原清洗工艺,棉针织物活性染色与抛光一浴工艺及活性染色后皂洗酶后处理工艺。并与相应的传统工艺对比其工艺曲线、质量水平、节能减排效果及污染物浓度降低情况。客观评价各类工艺的优缺点,建议生产厂家根据产品质量要求,选用相应高效助剂,并结合实际生产设备优化工艺后使用,节能减排效果将更加显著。     

Air distribution in room ventilated by fabric air dispersion system

Several researches about airflow distribution in a room generated by fabric air dispersion system (FADS) were reported, but details about the simulation in computer fluid dynamics (CFD) method were not elaborated. In present work The commercial software FLUENT with standard k−ε$k-\epsilon$ turbulence model is applied to predict air distribution in a room ventilated by FADS in penetration mode, where FADS is described with the porous media model based on the modified Forchheimer equation. And more details about the simulation are given. Flow visualization near the region of FADS is conducted using dry-ice as a smoking material. The distribution of indoor air velocity and temperature and draught rating (DR) around the ankle and neck level are predicted. The simulation well matches the corresponding experimental value and results of earlier work. Results showed that air is radially discharged out in the direction perpendicular to the spatial cambered porous fibre in lower velocity, and evenly distributed along its length direction when air is distributed by FADS in penetration mode. The velocity of indoor air is very low, and the vertical air temperature difference is small (less than 2 K). DR around the ankle and neck is immune to supply air flow rate and location, which is less than the comfort limit of ASHRAE Standard 55-2004. In addition, airflow pattern is greatly impacted by the location and strength of heat load.     

开放的社区与城市生活--宁波北岸琴森小区设计思考

该文通过介绍宁波北岸琴森小区的设计实践，对城市中心区大规模多层次的社区空间营造过程的剖析，指出城市社区应当是开放的、连续的、多样的、能够融入城市空间肌理和多层次城市生活的人性化社区。     

詹明信谈库哈斯、建筑和空间

文章讨论了美国杰出的马克思主义批评家詹明信在全球资本主义的历史背景中,如何阐述库哈斯的建筑,他的建筑与后现代主义建筑之间有何差异,这种差异如何形成并给出有意义的诠释。     

Bleaching of Knitted Cotton Fabric Applying Ozone

Several samples of knitted cotton fabric in raw state were impregnated with a solution of industrial wetting detergent and treated directly with ozone gas in a closed chamber. Working conditions for the variables: time, pH of the impregnation solution, residual pickup and feed flow rate of oxygen (for ozone generation) were investigated to identify the effects on whiteness degree and fabric strength. The application of ozone proved to be an efficient and promising technology with low water usage.     

Fabric electrodes coated with polypyrrole nanorods for flexible supercapacitor application prepared via a reactive self-degraded template

Wearable energy storage devices that can be used in the garment industry are strongly required to power E-textiles. In this article, polypyrrole (PPy) nanorods were deposited on cotton fabrics via in situ polymerization of pyrrole in the presence of the fibrillar complex of FeCl₃ and methyl orange as a reactive self-degraded template. The obtained fabrics could be directly used as supercapacitor electrodes, with a maximum specific capacitance of 325 F g⁻¹ and an energy density of 24.7 Wh kg⁻¹ at a current density of 0.6 mA cm⁻². The capacitance remained higher than 200 F g⁻¹ after 500 cycles.     

Canonical analysis of the Kawabata and sliding fabric friction measurement methods

Abstract

The aim of this study was to identify the latent structure and potential relationships between two sets of frictions measurements of warp-and-weft fabrics made with the sliding method and the Kawabata system (KES FB-4 method). First, linear relationships between all pairs of friction-related variables for the two methods were assessed and found to be weak and statistically not significant in most cases. Second, linear regression was applied to the variables previously exhibiting significant correlation only but the variables were found not to be useful for developing accurate predictive models. Third, multiple linear regression between a Kawabata variable and various parameters of the sliding method was used to construct a model that proved inaccurate owing to multicollinearity in the regressors; also, the method only allowed a single-dependent variable to be related. This was not the case with canonical correlation, which allowed two sets of variables to be correlated through multivariate analysis. This technique revealed a significant relationship between the two sets of friction-related variables.