基于VB的断面程序设计

主要针对导线极坐标法测设路线曲线的方法,通过到实地采集纵横断面点数据,研究并建立了与之相应的数据处理与内业图形绘制系统,实现了路线工程测量的现代化。     

Critical contact angle for coarse sphalerite flotation in a fluidised-bed separator vs. a mechanically agitated cell

This work investigates the critical contact angle for the flotation of coarse (850–1180 μm, 425–850 μm and 250–425 μm) sphalerite particles in an aerated fluidised-bed separator (HydroFloat) in comparison to a mechanically agitated flotation cell (Denver flotation cell). In this study, the surface chemistry (contact angles) of the sphalerite particles was controlled by varying collector (sodium isopropyl xanthate) addition rate and/or purging the slurry with either nitrogen (N₂) or oxygen (O₂) before flotation. The flotation performance varied in response to the change in contact angle in both the aerated fluidised-bed separator and the mechanically agitated cell. A critical contact angle threshold, below which flotation was not possible, was determined for each particle size fraction and flotation machine. The results indicate that the critical contact angle required to float coarse sphalerite particles in a mechanically agitated cell was higher than that in the fluidised-bed separator, and increased as the particle size increased. At the same particle size and similar contact angles, the recoveries obtained by the aerated fluidised-bed separator in most cases were significantly higher than those obtained with the mechanically agitated flotation cell.     

岸边集装箱起重机节能发电系统的设计

针对港口岸边集装箱起重机设计了一种新型高效的节能发电方案,利用简单有效的机械传动方式,在原有控制系统的基础上,增加部分闭环控制系统,实现无级变矩,使发电量最大化。运用ADAMS软件对下降过程中可调变速器的状态进行运动学仿真,并建立节能系统发电方案,以及控制流程。     

Dielectric and magnetic studies of 0.5Bi2/3Cu3Ti4O12 - 0.5Bi3LaTi3O12 nano-composite ceramic synthesized by semi-wet route

A nano-composite electro ceramic with the chemical composition of 0.5Bi_2/3Cu₃Ti₄O₁₂ - 0.5Bi₃LaTi₃O₁₂ was synthesized by a semi-wet route using high purity metal nitrate and solid TiO₂ in a stoichiometric ratio. X-ray diffraction (XRD) analysis showed the presence of Bi₃LaTi₃O₁₂ (BLTO) and Bi_2/3Cu₃Ti₄O₁₂ (BCTO) phases in the composites sintered at 900 °C for 8 h. Transmission electron microscope (TEM) analysis of the composite shows the presence of nanoparticles in the range of 55±3 nm. Atomic force microscopy (AFM) study also substantiates the presence of nanoparticles in the composite. Scanning electron microscope (SEM) images show that the surface morphology consists of plates like and spherical grains. The study of PE hysteresis loop revealed no saturation polarization which suggested lossy capacitor behavior of the composite. Magnetic behavior of the composite shows the weak ferromagnetic nature in M-T and M-H curve. The High observed value of dielectric constant (ε’=13.94×10³) of the composite may be due to the presence of space charge polarization.     

Electrical connectors for blanket modules in ITER

Blanket electrical connectors (E-straps, ES) are low-impedance electrical bridges crossing gaps between blanket modules (BMs) and vacuum vessel (VV). Similar ES are used between two parts on each BM: the first wall panel (FW) and shield block (SB). The main functions of E-straps are to: (a) conduct halo currents intercepting some rows of BM, (b) provide grounding paths for all BMs, and (c) operate as electrical shunts which protect water cooling pipes (branch pipes) from excessive halo and eddy currents. E-straps should be elastic enough to absorb 3-D imposed displacements of BM relative VV in a scale of ±2 mm and at the same time strong enough to not be damaged by EM loads. Each electrical strap is a package of flexible conductive sheets made of CuCrZr bronze. Halo current up to 137 kA and some components of eddy currents do pass through one E-strap for a few tens or hundreds milliseconds during the plasma vertical displacement events (VDE) and disruptions. These currents deposit Joule heat and cause rather high electromagnetic loads in a strong external magnetic field, reaching 9 T. A gradual failure of ES to conduct Halo and Eddy currents with low enough impedance gradually redistributes these currents into branch pipes and cause excessive EM loads. When branch pipes will be bent so much that will touch surrounding structures, the Joule heating in accidental electrical contact spots will cause local melting and may lead to a water leak.The paper presents and compares two design options of E-straps: with L-shaped and Z-shaped elastic elements. The latter option was developed in 2012 on the basis of more thoughtful analysis of bi-directional cyclic loading conditions influencing a fatigue lifetime. Detail comparative simulations of current and field patterns and subsequent analysis of the fatigue strength and technological assessment allowed make a final choice for the E-strap design in ITER.     

Winding Method to Reduce Vibration and Loss Caused by Fractional Slot of Synchronous Machine

Fractional‐slot windings are widely used in rotating machines in order to improve the output voltage waveform, increase the design flexibility, and gain many other advantages. However, fractional‐slot windings are known to produce different harmonic components such as an even order and/or fractional number of space flux harmonics compared to integral‐slot windings. These harmonics may increase stray losses and cause stator core vibration. This paper describes an analysis of space flux harmonics and proposes new winding methods such as “novel interspersed windings” to reduce these harmonic components. The proposed winding methods were verified by numerical analysis and model tests.     

从预算合约角度看房地产企业产品力提升

结合工作经验,简要介绍了房地产企业产品策划阶段、规划设计阶段、项目实施阶段以及物业服务/运营阶段的预算合约与产品力提升的关系,阐明了预算合约在房地产企业产品力提升过程中的重要作用,从而为房地产企业开发提供参考。     

基于.net的频带传输系统设计与实现

针对频带传输存在概念抽象、知识点深等教学问题,设计了一款基于Visual Studio.net的频带传输系统,该系统采用结构化与面向对象相结合的方法进行开发,内容包含ASK、FSK、PSK的调制与解调技术.本文介绍了该系统的功能模块分析与设计,并对各种关键技术予以重点介绍.经测试,系统界面友好、交互性强,能够有效的降低课程学习的难度.     

Monitoring by Remote Sensing of Habitat Quality Changes in Xianyang City

With the accelerating process of society，economy and urbanization，land use and landscape changes have gradually become important to make effects on regional habitat quality.It is necessary to further investigate those two effects，the result of which can provide a scientific basis for regional habitat conservation and reasonable utilization of land，then will be of great importance in habitat protection and development of the region.In this paper，the study area was located in Xianyang city，Shaanxi Province，which had the frequent human activities and obvious land use changes.Based on the classification of land use data which interpreted by remote sensing，supported by ArcGIS software，the land use transfer matrix of Xianyang from 2000 to 2010 was analyzed.Landscape metrics were calculated by the Fragstats software，which represented for the landscape pattern changes and spatial characteristics.The InVEST model was selected to evaluate habitat quality in study area.The habitat quality changes was monitored.The results indicate that the integrated land use dynamics of Xianyang city is 2.34%，and the changes of land use rate is slow.The main transition from cultivated land and grassland to forest and construction land，which cause the area of first two land use types reduced，and the latter two types increased.The degree of fragmentation and the complexity of structure in landscape are higher than before.Habitat quality improved slightly，and its overall spatial pattern is that central and north areas are relatively higher than the south.Area percentage of excellent，good and poor grades increase，while the habitat quality of medium grade significantly decline.Among 14 districts and counties of habitat quality in Xianyang city，Xunyi County is the best，and the improved magnitude of Liquan county is the most significant.The main driving force of habitat quality change is the transform of land use pattern.Therefore，the relevant departments of Xianyang city should continue to implement the ecological protection measures，and increase the intensity about the protection and management of environment.Thereby to promote the coordinated sustainable development of land use and habitats.     

热力耦合作用下脉冲电流烧结初期驱动力研究

采用L–S型广义热弹性理论,建立了氧化铝粉末非等径三颗粒模型,探究脉冲电流烧结过程的热力耦合传播规律和烧结驱动力。结果表明,三颗粒系统中小颗粒的温度明显高于大颗粒,在颈部形成高温度梯度,由温度梯度形成的热扩散通量与空位扩散通量共同为脉冲电流烧结初期颈部物质迁移提供驱动力;随着烧结过程的进行,热扩散对烧结驱动力的影响越大;三颗粒系统的计算值小于两颗粒系统,这是由于两颗粒系统产生的热耗散较小。