无溶剂环保型单组分潜固化聚氨酯防水涂料的研制

采用环氧大豆油调整产品体系黏度,以潜固化剂固化方式制备了无溶剂单组分聚氨酯防水涂料。讨论了环氧大豆油和醛亚胺类潜固化剂的用量对产品的黏度、VOC含量以及涂膜力学性能的影响。结果表明,环氧大豆油用量在25~30份、潜固化剂的用量在1.5~2.0份时,所制备的无溶剂环保型单组分潜固化聚氨酯防水涂料能满足PU防水涂料GB/T 19250—2013的要求。     

Measurement of solubility and diffusion coefficients of ethylene in solid and molten low-density polyethylene with different melt indices

The diffusion behavior of ethylene in polyethylene is of great importance for the polymerization and degassing of polyethylene (PE) industry. Based on the gravimetric sorption and desorption measurement approach, an intelligent gravimetric analyzer is applied to obtain the solubility and diffusion coefficients of ethylene in solid low-density PE (LDPE) with different melt indices at 30°C to 70°C, 0 to 4 atm and in molten LDPE at 160°C to 230°C, 0 to 4 atm, respectively. Results indicate that both the solubility and diffusion coefficients of ethylene in solid LDPE are smaller than those in molten LDPE, while the dissolution enthalpy and diffusion activation energy of ethylene in solid LDPE are higher. In addition, one- and two-dimensional diffusion models are built and the effects of particle size, polymer properties, and operation conditions are systematically investigated on the diffusion behaviors of ethylene in solid and molten LDPE.     

Enhancement of solar cell efficiency via luminescent downshifting by an optimized coverglass

A novel approach to enhance the solar cell efficiency via employing a luminescent downshifting mechanism is presented in this work. Gold metal ions were diffused into a commercially available sodalime silicate glass using a versatile field-assisted solid-state ion diffusion technique under different experimental conditions. Some of these samples were irradiated with ns-laser to segregate the diffused ions into dimers and trimers to enhance their luminescence characteristics. The consequent structural modifications in the glass matrix were examined using Fourier transform infrared spectroscopy. Optical absorption and luminescence measurements were performed to check the presence of resonant plasmonic absorption of nanoclusters and suitability of the samples as luminescent downshifters, respectively. At UV excitation wavelengths (260 and 340 nm), the doped samples downshifted the solar spectrum compared to their undoped counterparts. Furthermore, ns-laser irradiation of the doped samples significantly enhanced the luminescence intensity in comparison to the unirradiated samples. Real-time performance of these samples was tested by measuring the output power of a Si solar cell covered with the treated coverglass when illuminated with a solar simulator. Finally, the Vicker's micro-indentation was applied to conclude that ionic diffusion increased the glass hardness as well.     

加压和超临界条件下乙醇分子的缔合

引言 在化学和化工领域,分子扩散系数是过程设计和装置优化所需的基本数据之一[1].乙醇作为一种高效绿色溶剂,具有良好的溶剂性能和比较温和的临界温度、临界压力(Tc=514.3 K,pc=6.38MPa),在食品、医药和化工等领域有巨大的应用空间[2].     

国有企业技术创新的路径分析

创新是一个民族的灵魂,也是企业生存和发展的根本动力.国有企业技术创新,主要体现在自主创新、技术扩散和技术模仿诸环节.国有企业从自身的实际情况出发,有所为有所不为,科学理解和正确运用技术创新的本质内涵,从而在技术创新中促进企业的发展.     

钛合金与不锈钢的钎焊和扩散焊技术研究现状及发展趋势

综述了钛及其合金与不锈钢连接技术研究现状和发展趋势,分析了钛及其合金与不锈钢连接的特点以及目前存在的问题,比较了各种连接方法的优缺点,重点论述了钎焊和扩散焊方法.     

造纸废水处理过程温室气体排放代理模型研究

造纸废水处理过程具有高维、非线性和不稳定性等特点,并且其温室气体排放受诸多因素影响,目前缺乏可描述该过程的模型,因此难以对造纸废水处理过程的温室气体排放进行有效地管控与优化。本课题基于造纸废水处理温室气体产生机理,提出将响应面模型（Response Surface Model,RSM）、Kriging等方法与高维模型表征（High Dimensional Model Representation,HDMR）相结合,建立造纸废水处理过程中温室气体排放的代理模型,保障模型精度,同时降低优化设计所需计算成本。研究结果表明,对比于RSM-HDMR,Kriging-HDMR具有更高的近似精度,其验证结果R²大于0.95,更适用于高维、非线性的造纸废水处理过程。最后还基于Kriging-HDMR进行了关键参数的灵敏度分析,发现溶解氧传递系数和外循环流量对造纸废水处理温室气体减排最为关键。     

双原料化一室二段气流床气化炉工艺及应用

在介绍甲烷转化工艺和煤气化工艺制取合成气生产技术的基础上,着重介绍了以煤炭和煤层气中的甲烷为原料的双原料化合成气制造工艺。论述了该工艺流程的特点,对其关键设备———一室二段气流床气化炉从设备结构和应用效果方面进行了介绍。结果表明,在富产煤层气的地区,以双原料化工艺制取的合成气生产甲醇和二甲醚,生产效率比传统方法高10%~16%,并可减轻煤炭利用对环境的影响。     

制浆过程木材浸渍研究进展

从多个角度对木材浸渍研究进展进行了分析论述,全面阐述了基于渗透理论及扩散理论的木材浸渍理论模型,介绍了木材浸渍研究的3种常用连续测量方法,详细论述了木材浸渍的影响因素及改善措施。     

各向异性扩散方程在数字图像去噪中的应用

研究了各向异性扩散方程在去除数字图像瑞利噪声中的应用.在理论上对其去噪原理进行了分析,并在此基础上提出了改进算法.在实践中,通过实验给出了改进算法更好的去噪效果,并说明了这种方法的特点和适用情形.将这种方法与中值滤波结合提出了混合法同时改善被瑞利噪声和随机散粒噪声污染的图像.