校园网的升级与改造

基于中南民族大学校园网建设需求、目标及设计原则,论述了在校园网升级改造中的网络技术选择、设备选型,设计了网络拓扑图.在实施时,实现了以千兆以太网为核心技术,千兆交换为主干、百兆交换机输出到桌面的宽带校园网的网络结构.     

大学英语口语教学中的学习焦虑及对策

在大学英语口语教学中,许多同学不愿开口讲英语,其中焦虑是导致这一现象的一个重要原因。文章重点讨论焦虑原理,导致焦虑的原因及减轻焦虑的对策,旨在进一步提高大学英语口语教学的效果,提高学生学习英语的积极性。     

“一带一路”倡议下海南国际化人才培养模式探析

"一带一路"作为国家顶级合作倡议,除了造福沿线国家和人民之外,也对人才培养提出了更高的要求。在此背景下,海南作为"一带一路"建设的重要节点,亟须培养一批能适应新时代发展的高素质国际化人才。基于现有人才培养模式,本研究从开设国际联合教育实验室、校政企共建资源、涉外人才培养以及海南本土人才培养四方面进行深入探析,为"一带一路"倡议下海南国际化人才培养模式的创新提供建议。     

反思在服务学习中的作用研究

反思是服务学习的一个重要特质,也是实施过程中一个重要的阶段,是保证服务学习质量,提升服务效果的重要组成部分。本文主要从反思的理论基础,反思的特质以及反思的作用等方面阐述反思在服务学习中的地位和价值,有助于更好地开展服务学习,提升服务学习效果。     

SwiftArray: Accelerating Queries on Multidimensional Arrays

Scientific instruments and simulation programs are generating large amounts of multidimensional array data.Queries with value and dimension subsetting conditions are commonly used by scientists to find useful information from big array data,and data storage and indexing methods play an important role in supporting queries on multidimensional array data efficiently.In this paper,we propose SwiftArray,a new storage layout with indexing techniques to accelerate queries with value and dimension subsetting conditions.In SwiftArray,the multidimensional array is divided into blocks and each block stores sorted values.Blocks are placed in the order of a Hilbert space-filling curve to improve data locality for dimension subsetting queries.We propose a 2-D-Bin method to build an index for the blocks’value ranges,which is an efficient way to avoid accessing unnecessary blocks for value subsetting queries.Our evaluations show that SwiftArray surpasses the NetCDF-4 format and FastBit indexing technique for queries on multidimensional arrays.     

Flow and heat transfer behaviour of nanofluids in microchannels

Flow and heat transfer of aqueous based silica and alumina nanofluids in microchannels were experimentally investigated. The measured friction factors were higher than conventional model predictions at low Reynolds numbers particularly with high nanoparticle concentrations. A decrease in the friction factor was observed with increasing Reynolds number, possibly due to the augmentation of nanoparticle aggregate shape arising from fluid shear and alteration of local nanoparticle concentration and nanofluid viscosity. Augmentation of the silica nanoparticle morphology by fluid shear may also have affected the friction factor due to possible formation of a core/shell structure of the particles. Measured thermal conductivities of the silica nanofluids were in approximate agreement with the Maxwell-Crosser model, whereas the alumina nanofluids only showed slight enhancements. Enhanced convective heat transfer was observed for both nanofluids, relative to their base fluids (water), at low particle concentrations. Heat transfer enhancement increased with increasing Reynolds number and microchannel hydraulic diameter. However, the majority of experiments showed a larger increase in pumping power requirements relative to heat transfer enhancements, which may hinder the industrial uptake of the nanofluids, particularly in confined environments, such as Micro Electro-Mechanical Systems (MEMS).     

Dendrite growth and micromechanical properties of rapidly solidified ternary Ni-Fe-Ti alloy

The rapid solidification of undercooled liquid Ni_(45)Fe_(40)Ti_(15)alloy was realized by glass fluxing technique.The microstructure of this alloy consists of primaryγ-(Fe,Ni)phase and a small amount of interdendritic pseudobinary eutectic.The primaryγ-(Fe,Ni)phase transferred from coarse dendrite to fragmented dendrite and the lamellar eutectic became fractured with the increase of undercooling.The growth velocity ofγ-(Fe,Ni)dendrite increased following a power relation with the rise of undercooling.The addition of solute Ti suppressed the rapid growth ofγ-(Fe,Ni)dendrite,as compared with the calculation results of Fe-Ni alloy based on LKT model.The microhardness values of the alloy and the primaryγ-(Fe,Ni)phase increased by 1.5 times owing to the microstructural refinement caused by the rapid dendrite growth.The difference was enlarged as undercooling increases,resulting from the enhanced hardening effects on the alloy from the increased grain boundaries and the second phase.     

Facile construction of novel CoMoO4 microplates@CoMoO4 microprisms structures for well-stable supercapacitors

A simple and controllable strategy has been developed to fabricate CoMoO_4 microplates/CoMoO_4 microprisms(CMCMs) structures on Ni foam via a facile, cost-effective, two-step hydrothermal route. The as-grown 3D architecture exhibited excellent areal capacitance of 4.33 F cm~(-2)at a galvanostatic chargedischarge current density of 50 mA cm~(-2)(6 Ag~(-1)) and outstanding cycle performance with only 2.8%degradation over 6500 cycles in the 3 M KOH solution. The asymmetric all-solid-state supercapacitors based on activated carbon(AC) and CMCMs exhibited much better electrochemical performance than the symmetric counterpart, showing an areal capacitance of 95.22 mF cm~(-2)at the current density of 12 m A cm~(-2)and excellent cycling stability with 92.27% of the initial capacitance after 5000 cycles. These results may provide useful guidelines for materials selection and configuration designs for the novel energy storage devices based on Co Mo O4 components and substrates.     

好好芭叶片RNA提取方法和cDNA干旱消减文库的构建

介绍了从好好芭成熟叶片中提取总RNA的方法;用含有SDS的裂解液裂解细胞,用DNase除去可能出现的DNA干扰,再经植物提取试剂盒纯化后,获得了高质量的完整RNA,可用于基因编码序列的克隆和基因表达的mRNA分析等精细研究,并进一步构建了好好芭干旱消减文库.     

基于扩散模型的ZnO/p-Si异质结伏安特性研究

为了揭示ZnO/p-Si异质结的导电机理,基于p-n结扩散模型和Anderson扩散模型推导了ZnO/p-Si异质结在理想情况下的伏安特性,并分析了掺杂浓度、工作温度以及能带补偿的影响.结果表明:当正向偏压超过势垒高度时,界面两边多数载流子由耗尽变为堆积,形成反向势垒,对异质结的正向电流起阻碍作用;当外加正向电压等于内...