煤炭产业塑造不同规模煤企间的组织形式

从产业结构调整和煤炭产业价值链的角度出发 ,分析了煤炭产业调整应塑造不同规模煤企间有效协同的组织形式 ,这种组织形式有利于大煤企发展煤基多元化产业链 ,调整产品结构 ,并集中有限的资源 ,投入到煤炭产业价值链中创造附加价值最多的核心环节 ,有效提高我国大煤企的核心竞争力。同时有利于克服煤炭产业过度分散和过度竞争的现状 ,提高煤炭产业集中度和实现有效竞争 ,有利于政府对煤炭产业的宏观调控 ,提高我国煤炭产业的国际竞争力。     

变压器铁心智能叠装技术及发展方向

变压器是电力系统的核心设备,其铁心制造对变压器行业的发展至关重要。本文着重介绍了目前国内外变压器铁心的智能叠装技术并对其未来发展方向做了展望。     

采用“钻芯-回弹”综合法检测预拌混凝土强度

“钻芯-回弹”综合法通过将钻芯法和回弹法的有机结合,有效修正了预拌混凝土中粉煤灰、外加剂等对回弹值的影响,以对结构较小的破损,带来检测精度的大大提高,并能全面反映结构混凝土质量。     

The solids flow in the riser of a Circulating Fluidised Bed (CFB) viewed by Positron Emission Particle Tracking (PEPT)

Circulating Fluidised Beds (CFB) are attracting increasing interest for both gas-solid and gas-catalytic reactions, although the operating modes in these two cases are completely different. In modelling CFBs as reactors, the solids residence time is an important parameter. Previous studies mostly assess operations at moderate values of the solids circulation rates (≤ 100 kg/m² s), whereas gas-catalytic reactions and e.g. biomass pyrolysis require completely different operating conditions. In the current work, Positron Emission Particle Tracking (PEPT) is used to study the movement and population density of particles in the CFB-riser.The PEPT results can be used to obtain: (i) the vertical particle movement and population density in a cross sectional area of the riser; (ii) the transport gas velocity (U_tr) required in order to operate in a fully established circulation mode; (iii) the overall particle movement mode (core flow versus core/annulus flow); and (iv) the particle slip velocity (U_s).Only in a core flow mode can the particle slip velocity be estimated from the difference between the superficial gas velocity (U) and the particle terminal velocity (U_t). The slip velocity is lower than U − U_t outside the core flow mode. To operate in core flow, the superficial gas velocity should exceed U_tr by approximately 1 m/s and the solids circulation rate should exceed 200 kg/m² s.     

塑料水龙头壳体模具设计

分析塑料水龙头的成型特点,采用了圆弧抽芯.在设计中,通过分析塑件的结构,采用了一模一腔的模具布局形式.在模具设计过程中,对分型面的设计,浇注系统、冷却系统、脱模机构进行了介绍.经生产验证,模具结构合理,具有一定的推广价值.     

Facile fabrication of pseudo-microspherical ZnO/CdS core-shell photocatalysts for solar hydrogen production by water splitting

Photocatalytic hydrogen production attracts great attention due to its clean energy conversion and renewable usage. In order to achieve efficient charge separations in photocatalysts, pseudo-microspherical ZnO/CdS core-shell structures were fabricated by precipitation method. ZnO pseudo-microspheres of about 2 µm diameter were uniformly synthesized, and they were used as core materials covered with various amounts of CdS shell nanoparticles. The highest hydrogen production rate from as-prepared photocatalysts was 146 μmol g⁻¹ h⁻¹ at 63 wt% CdS content under one sun irradiation condition. After thermal treatments, it was much improved to 241.2 μmol g⁻¹ h⁻¹ at the same CdS content possibly due to the increased crystallinity and efficient charge flows with an aid of additional CdO component. Reproducibility of hydrogen production revealed stable mode of operation for three consecutive runs. Therefore, ZnO/CdS/CdO ternary photocatalyst systems provide efficient charge separations and electron flows for improving solar hydrogen production by suppressing electron-hole recombinations.     

Effect of particle size on the mechanical properties of polystyrene and poly(butyl acrylate) core/shell polymers

The effects of particle size and polymer location (core or shell) on the mechanical properties of core/shell materials composed of polystyrene (PST) and poly(butyl acrylate) (PBA) made by a two-stage emulsion or microemulsion polymerization process are reported. Low-seed content (LSC) latexes were made by batch polymerization in microemulsions stabilized with DTAB in the presence of an organic salt (dibutyl phosphite). High-seed content (HSC) latexes were produced by microemulsion or emulsion polymerization in semi-continuous process. These latexes were subsequently used to form core/shell particles of PST/PBA or PBA/PST and their mechanical properties were examined and compared. Our results indicate that core/shell particle size and the location of the polymers have important effects on the mechanical properties.     

基于IC3标准的高职院校计算机基础课程改革探索与实践

计算机基础课程核心是培养高技能应用型人才利用计算机收集、处理加工信息的基本能力。为了使课程更能适应培养学生职业能力和全面信息素养的要求,在教学中引入IC3认证,从教学内容、教学模式、考核方式三方面进行改革的探索与实践。     

嵌入式Linux在开发板gec2410上的完全启动过程

本文介绍了嵌入式Linux在开发板上的启动过程与在普通PC机上的启动过程的不同,以及配置嵌入式Linux系统开发平台的几个重要文件．重点介绍了嵌入式Linux在开发板上启动所涉及到的两个文件的详细启动过程,这两个文件是我们在gec2410开发板上配置开发平台时制作的,且能正确使用。     

浅谈高职院校品牌专业建设与核心竞争力的培育

针对高职院校专业建设上存在的问题,提出提升院校核心竞争力,创建本院校的品牌专业的观点,并通过师资队伍建设合理化,产学研一体化,分类培养与岗位就业紧密结合,充实完善实训设施,以学生为主体,切实提高人才培养质量等途径来实现。