用一般辅助函数判定渐近稳定性

本文给出了用一般辅助函数判定常微分方程稳定性的方法,它是李雅普诺夫直接方法的推广,用辅助函数对方程作宏观控制。     

Effects of Waterborne Elastic Polyester with Different Compositions on the Properties and Compatibility of Maize Starch

Waterborne elastic polyester (WEP) with different content of hard polyester was applied in the maize starch (MS) based composites (MS/WEP) via solution casting method.The effects of WEP with different contents of hard polyester on the structure and properties of starch were studied by Fourier transform infrared,X-ray diffraction,ultraviolet-visible,tensile test,differential scanning calorimeter,thermogravimetric analysis and moisture measurement.The experimental results show that the addition of...     

Preparation of viscoelastic gel‐like halloysite hybrids and their application in halloysite/polystyrene composites

Self‐reinforcement gel‐like halloysite nanotube (g ‐HNT ) hybrids with various viscoelastic behaviors were fabricated by firstly treating with various concentrations of sodium hydroxide (NaOH ) solution and then grafting tertiary amine and ion‐exchange reacting with sulfonate anions. The morphology, composition, thermal stability and rheological behavior of the g ‐HNT hybrids were systematically characterized and analyzed using various methods. It is found that the viscoelasticity of g ‐HNT hybrids can be easily regulated by using different NaOH solution‐treated HNTs as inorganic core and temperatures. In addition, the g ‐HNT hybrids treated with medium concentration of NaOH (0.06 mol L^?1) have the lowest viscosity and highest level of dispersion compared with those treated with other concentrations of NaOH solution. Due to the amphiphilic nature of g ‐HNT hybrids and their lower viscosity than HNT powder, as novel hybrid fillers, they were utilized to prepare polystyrene composites by direct melt blending for achieving simultaneous reinforcement and plasticization effects. Besides the above mentioned advantages, the thermal conductivity of polystyrene composites is also surprisingly improved by reducing the interfacial mismatch between the filler and polymer matrix. The solvent‐free and self‐reinforcement hybrids provide a convenient and green path for fabricating high‐performance polymer composites. © 2017 Society of Chemical Industry     

接枝改性对淀粉与PVA混溶性的影响

以过硫酸钾-硫代硫酸钠引发淀粉与甲基丙烯酸接枝,其产物经红外光谱分析证明为接枝产物.以接枝共聚物作为增容剂,考察了PVA醇解度、接枝淀粉加入量以及接枝率对淀粉与PVA溶液共混体系的影响.同时考察了接枝淀粉与PVA-1799两种浆液溶液共混体系的稳定性.结果表明:接枝淀粉的加入可提高共混浆液的稳定性;随着PVA醇解度增加或淀粉接枝率、接枝产物添加量的增加,浆液的稳定性提高.     

混凝土中钢筋锈蚀的研究现状

详细阐述了混凝土中钢筋锈蚀的研究现状，从钢筋锈蚀的机理、速度、程度、防护和锈蚀钢筋的性能五个方面总结构归纳了国内外的研究成果。     

任意截形螺旋铣刀制造模型研究

螺旋铣刀在数控技术下可获满意产品，但降维技术无疑为其节省成本提供可能，本文以几何学为依据，给出一维数控磨制任意截形的螺旋铣刀在方案及数学模型，并用算例验证了其方案折可行性与模型的可靠性。     

A novel approach to prepare solvent-free cerium dioxide nanofluids

This paper develops a novel approach to prepare solvent-free cerium dioxide (CeO₂) nanofluids through N,N-didecyl-N-methyl-N-(3-trimethoxysilylpropyl) ammonium chloride covalently grafted on the surface of CeO₂ nanoparticles as core, and then poly(ethylene glycol) 4-nonylpheny 13-sulfopropyl ether sodium salt was grafted on the surface of CeO₂ nanoparticles through ion exchange reaction. It is obviously observed that CeO₂ nanofluids exhibited a solid state at room temperature, whereas they behave as liquid-like when being heated to above 45°C. To detect the properties of CeO₂ nanofluids, the morphology, thermal stability, dispersibility, and rheological behavior of CeO₂ nanofluids are mainly investigated. It is found that CeO₂ nanofluids can flow without solvent existence. Meantime, it shows good dispersion and stability in water and other organic solvents for weeks due to amphiphilic properties of the modifier molecules.     

支链淀粉含量对玉米淀粉浆料糊化和结晶性能的影响

将支链淀粉加入到玉米淀粉中组成混合纺织浆料,采用RVA和XRD研究了支链淀粉含量对淀粉浆料流变性以及结晶性能的影响。结果表明：随着支链含量的增加,淀粉浆液的峰值粘度、谷值粘度、末值粘度逐渐降低,衰减值和回生值也逐渐变小,达到峰值的时间缩短,加入支链淀粉有利于淀粉糊化和浆液稳定;同时,淀粉膜的结晶度随支链淀粉含量增加而减小,晶体尺寸呈增长趋势。     

生产技术知识在企业内部审计中的作用及发挥

随着审计领域的不断扩展和审计内容的不断完善,生产技术知识在企业内部审计中的重要性越来越突出。结合石油石化行业特点论述生产技术知识在企业内部审计中的应用,就如何进一步发挥其在内部审计中的作用进行阐述并提出相关建议。     

关于硬质合金渐开线型插齿刀CAD／CAM模型研究

本文给出了一种别于传统设计方案的渐开线齿形硬质合金插齿刀设计方案和相应ＣＡＤ／ＣＡＭ的数学模型，并通过实例计算验证了新方案的优越性，制造模型的可靠性．