人工神经网络模型在瓦斯预测中的应用

通过对神经网络的基本原理和学习算法的分析，建立了基于瓦斯涌出量预测的BP网络应用模型，采用Delphi编程语言，预测了瓦斯的涌出量，并结合实例进行了验证。     

生物质协同流程工业节能、降污、减碳路径思考

流程工业的低碳/零碳/负碳转型,需从节能、降污、减碳出发,根本上要在能源和原料供给侧摆脱传统化石能源的束缚。风电、光电、水电等为未来社会提供源源不断的可再生能源,但其不具备资源属性,而生物质兼具能源和资源属性,是未来替代化石燃料和原料的重要载体。本文指出,当前生物质转化主要集中在能源、材料、化学品等领域,以生物甲烷、乙醇、航煤等为代表的生物质能源取得了阶段性成果。将生物质转化技术与流程工业耦合,是当下流程工业低碳转型的重要手段,也是实现未来零碳/负碳目标的根本性措施。本文从生物质气化热电联用、生物质气化与燃煤耦合发电、水泥工业生物质替代燃料等案例出发,简要阐述了生物质转化与流程工业耦合面临的挑战,以及未来亟需发展的可再生能源为主的流程再造新理论和前沿颠覆性技术。     

Numerical Simulation and Technological Parameter Optimization for Quenching Process of a Gas Turbine Compressor Disk Based on Metallo-Thermo-Mechanics

Thermal, mechanical and microstructural phenomena are involved in the process of steel quenching. Based on the coupled metallo-thermo-mechanics theory, a calculation model has been developed in this study to simulate the quenching process of a gas turbine compressor disk by finite element method. The thermal physical and mechanical properties were treated as a functions of temperature. Moreover, a series of subroutines were developed on the MARC software platform. Consequently, simulated results on temperature, internal stress and distortion during the quenching were illustrated. With the aid of the simulated results, an optimum quenching scheme was proposed. The quenching process simulated in this study appears to be a promising tool in design of heat-treatment processing parameters for gas turbine compressor disks.     

TC6钛合金卡环锤锻过程模具受力的有限元分析

在TC6钛合金卡环的高温锤锻过程中,模具承受非常大的应力。本文采用刚粘塑性有限元法模拟了TC6钛合金卡环的高温锤锻过程,给出了变形过程金属的流动情况、锻造载荷以及不同时刻模具的应力分布。模拟结果可以为该零件的成形工艺和模具设计提供参考。     

An Efficient SCF-PEKS Without Random Oracle Under Simple Assumption

The Public key encryption scheme with keyword search (PEKS), firstly put forward by Boneh et al., can achieve the keyword searching without revealing any information of the initial data. However, the original PEKS scheme was required to construct a secure channel, which was usually expensive. Aimed at resolving this problem, Baek et al. put forward an improved scheme, which tried to construct a Secure channel free PEKS (SCF-PEKS). Subsequently, several SCF-PEKS schemes were proposed, however most of them turned out only secure in the random oracle model, which possibly lead to the construction of insecure schemes. Therefore, Fang et al. put forward an enhanced SCF-PEKS construction, which was provably secure in the standard model, however this construction needed a strong and complicated assumption. Then Yang et al. put forward an SCF-PEKS construction under simple assumption, but their construction had a big reduction in efficiency. In this article, we propose an SCF-PEKS construction, which is provably secure under the same assumption as that of Yang et al.'s scheme, however, with better performance. Then we give its full security proof, along with the performance analysis. Finally, we improve the SCF-PEKS construction to resist Keyword guessing attack (KGA) and give its security demonstration.     

催化裂化催化剂形貌分析方法的建立

结合显微镜观察,通过分析毫米级颗粒、微米级Duke粒子及催化裂化催化剂,研究动态数字图像分析仪CamsizerX2分析颗粒形貌的合理准确性。考察分散方式、分散压力和记录颗粒数量因素的影响,建立了催化裂化催化剂球形貌分析方法。     

原子吸收分光光度法测定硬脂酸钙中的钙

用原子吸收分光光度计测定了硬脂酸钙中的钙,确定了仪器的最佳工作条件.测定结果表明方法线性良好,r=0.999 9,加标回收率为98.9%～101.7%,相对标准偏差0.37%;测定结果与行业标准一致.操作简单易行,可以满足实际工作需要,并可对同一样品溶液进行其他元素的测定,更适合于成批样品的例行分析.     

腐乳品质改善的研究进展

腐乳是通过微生物发酵而成的一种滋味鲜美,营养丰富的佐餐食品,具有独特的风味以及良好的生理保健功能.结合国内外对腐乳的研究,主要对腐乳的生产工艺、微生物种类、风味物质、后发酵期的缩短以及腐乳生产和安全性控制进行了综述.相信随着人们健康意识的提高以及现代科学技术的应用,腐乳将具有更为广阔的发展前景.     

基于香气指纹图谱和多元化学计量法对黄金茶2号等级的判别分析

以黄金茶2号为研究对象,采用顶空固相微萃取-气相色谱-质谱联用技术建立不同等级黄金茶香气成分气相色谱-质谱指纹图谱,并通过化学计量法对两个等级的黄金茶进行判别分析。研究表明,2个等级的黄金茶中鉴定出81种香气组分,其中41种为共有香气组分。基于共有香气组分的正交偏最小二乘判别分析可以区分2个等级黄金茶,并筛选出9种差异香气组分,分别是庚醛、柠檬烯、反式-β-罗勒烯、1-辛醇、反式-4,8-二甲基-1,3,7-壬三烯、反-橙花叔醇、1,10-diepicubenol、epicubenol、十六酸甲酯。以9种差异香气组分为变量建立的线性判别方程对2个等级的黄金茶进行等级判别,自身验证和交叉验证正确率为100%。本实验结果可为黄金茶的分级提供客观量化的参考依据。     

Structural evaluation and mechanical property of boron nitride fibers during melt‐drawn fabrication process

Boron nitride (BN) fibers were fabricated on a large scale through the melt‐drawn technique from low‐cost boric acid, NH₃, and N₂. Evolution of structure and properties of BN fibers during the fabrication process was studied by Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), scanning electron microscope (SEM), and X‐ray photoelectron spectroscopy (XPS). The mechanical properties of BN fibers were tested and analyzed. The results shown that both the mechanical properties and the crystallinity of BN fibers slightly increased with the temperature from 450 to 850°C, due to the combination of the fused‐B₃N₃. For BN fibers heat‐treated at 850 or 1000°C, the tensile strength (σ^R) and elastic modulus (E) were strongly increased because of the increase in crystallization of the BN phase. The meso‐hexagonal BN fibers with a diameter of 5.0 μm were fabricated at 1750°C, of which the tensile strength (σ^R) and elastic modulus (E) are 1200 MPa and 85 GPa, respectively. BN fibers with excellent mechanical properties and proper diameters were obtained by nitriding of green fibers during their conversion into ceramic.