基于水性聚氨酯超纤革开纤工艺研究进展

超细纤维聚氨酯合成革是近年发展起来的新一代合成革。目前,生产超纤革含浸所用的树脂几乎全部为溶剂型聚氨酯,但大量有机溶剂的使用造成了环境污染和资源浪费,以水性聚氨酯替代溶剂型聚氨酯来含浸并生产超纤革势在必行,本文综述了基于水性聚氨酯超纤革开纤工艺研究进展,为基于水性聚氨酯超纤革的开纤工艺提供科学思路。     

Combined Decarbonization of Electrical Energy Generation and Production of Synthetic Fuels by Renewable Energies and Fossil Fuels

Power generation from renewable energy sources and fossil fuels are integrated into one system. A combination of technologies in the form of a carbon capture utilization (CCU)-combined power station is proposed. The technology is based on energy generation from fossil fuels by a coal power plant with CO₂ recovery from exhaust gases, and pyrolysis of natural gas to hydrogen and carbon, completed by reverse water-gas shift for the conversion of CO₂ to CO, which will react with hydrogen in a Fischer-Tropsch synthesis for synthetic diesel. The carbon from the pyrolysis can replace other fossil carbon or can be sequestered. This technology offers significant CO₂ savings compared to the current state of technology and makes an environmentally friendly use of fossil fuels for electricity and fuel sectors possible.     

Generating synthetic benchmark circuits for accelerated life testing of field programmable gate arrays using genetic algorithm and particle swarm optimization

Accelerated life testing (ALT) of a field programmable gate array (FPGA) requires it to be configured with a circuit that satisfies multiple criteria. Hand-crafting such a circuit is a herculean task as many components of the criteria are orthogonal to each other demanding a complex multivariate optimization. This paper presents an evolutionary algorithm aided by particle swarm optimization methodology to generate synthetic benchmark circuits (SBC) that can be used for ALT of FPGAs. The proposed algorithm was used to generate a SBC for ALT of a commercial FPGA. The generated SBC when compared with a hand-crafted one, demonstrated to be more suitable for ALT, measured in terms of meeting the multiple criteria. The SBC generated by the proposed technique utilizes 8.37% more resources; operates at a maximum frequency which is 40% higher; and has 7.75% higher switching activity than the hand-crafted one reported in the literature. The hand-crafted circuit is very specific to the particular device of that family of FPGAs, whereas the proposed algorithm is device-independent. In addition, it took several man months to hand-craft the SBC, whereas the proposed algorithm took less than half-a-day.     

基于DRGAN和支持向量机的合成孔径雷达图像目标识别

为解决SAR图像目标识别中样本缺乏和方位角敏感问题,提出了一种基于DRGAN和SVM的SAR图像目标识别算法。首先,采用多尺度分形特征对SAR图像进行增强,经过分割得到目标二值图像,基于Hu二阶矩估计目标的方位角。然后对估计得到的目标方位角进行量化编码,结合原始图像作为输入,对设计的DRGAN模型参数进行训练与优化。由于DRGAN中的深度生成模型将目标姿态与外观表示进行解耦设计,故可利用该模型将SAR图像样本变换到同一方位角区间。基于变换后的训练样本分别提取归一化灰度特征,利用SVM训练分类器。采用MSTAR数据集在多个不同操作条件下对提出的算法进行测试,实验结果表明,在带变体的标准操作条件下,能够达到97.97%的分类精度,优于部分基于CNN模型的分类精度,在4种扩展操作条件下的分类精度分别为97.83%,91.77%,97.11%和97.04%,均优于传统方法的分类精度。在SAR图像目标方位角估计存在一定误差的情况下,训练得到的GAN模型作为SAR图像目标旋转估计器,能够使得在不进行复杂样本预处理的前提下,仍然取得较高的SAR图像目标识别精度。     

Change detection in synthetic aperture radar images based on unsupervised artificial immune systems

In this paper, we propose a novel change detection method for synthetic aperture radar images based on unsupervised artificial immune systems. After generating the difference image from the multitemporal images, we take each pixel as an antigen and build an immune model to deal with the antigens. By continuously stimulating the immune model, the antigens are classified into two groups, changed and unchanged. Firstly, the proposed method incorporates the local information in order to restrain the impact of speckle noise. Secondly, the proposed method simulates the immune response process in a fuzzy way to get an accurate result by retaining more image details. We introduce a fuzzy membership of the antigen and then update the antibodies and memory cells according to the membership. Compared with the clustering algorithms we have proposed in our previous works, the new method inherits immunological properties from immune systems and is robust to speckle noise due to the use of local information as well as fuzzy strategy. Experiments on real synthetic aperture radar images show that the proposed method performs well on several kinds of difference images and engenders more robust result than the other compared methods.     

Potential of plasmonic microreactor for Photothermal hydrogen-enriched fuel production from biomethane

In the present article, a series of coupled computational physics - fluid dynamics models were developed aiming at assessing the feasibility of photothermal synthetic fuel production from biogas (biomethane) and steam blends using plasmonic nanostructure Ag/TiO₂ substrate (each, 0.1 μm in thickness) inside a thermal, momentum and mass transport boundary layer in a microreactor. A chain of partial and complete biogas reforming and water-gas shift reactions were modelled as the dominant chemical reactions responsible for synthetic fuel production from biomethane. Using equilibrium analysis, plausible thermodynamic operating conditions were identified and applied to the computational models. The effect of light wavelength (λ) on the reaction rate, chemical conversion extent, syngas quality, exergy partitioned in synthetic fuel, and composition of gas products were investigated. The results showed that the performance of the microreactor is wavelength-dependent. It was found that the highest production rate for the synthetic fuel was achieved at 580 nm < λ < 620 nm. Within the same wavelength range, the chemical conversion of biomethane to synthetic fuel reached 85% at steam to methane ratio of 3 and the synthetic fuel quality was >2.05, which is suitable for a Fischer-Tropsch process. It was also identified that the syngas quality of the synthetic fuel can be regulated by adjusting the wavelength of the light. The exposure time was also identified to be a critical parameter affecting the performance of the microreactor. For an exposure duration of up to 10 ns, high quality of synthetic fuel >2.05 can be achieved within the optimum wavelength range of 580 nm < λ < 620 nm.     

Bio-mediated generation of food flavors – Towards sustainable flavor production inspired by nature

BackgroundThe consumers’ trend toward naturalness and “clean-label” products advocates the development of “bio-mediated” tools including new processes for the generation of flavors. Today, many fundamental studies demonstrate the feasibility of producing individual flavor compounds or more complex flavoring preparations by fermentation or by enzymatic reactions. However, to turn research into industrial applications, the processes have to be simplified and optimized by combining chemistry, biology and process engineering know-how.Scope and approachThis review summarises recent basic research and development on cell and enzyme based formation of volatile flavors with focus on smart combinations of biocatalytic and thermal steps to enrich the natural flavor profile of foods. Ideally, targeted bioconversion of specific raw materials and ingredients will release flavor precursors required to generate the desired flavor profile by appropriate thermal processing.Key findings and conclusionsThe combination of fermentation or enzymatic treatment of raw materials with heat-induced food processes (e.g. drying, extrusion, roasting) represent an elegant approach in industrial food processing to generate flavors under mild conditions. This requires a good control of fermentation or enzymatic reaction steps to produce suitable substrates at the optimal concentrations adapted to the thermal processes. Using traditional cooking and minimal processing conditions (nature-inspired strategies) has become an attractive approach to generate authentic flavor profiles resonating with consumers’ demand for more naturalness.     

Anatase/rutile-TiO2 hollow hierarchical architecture modified by SnO2 toward efficient lithium storage

Hierarchical architecture of anatase/rutile-mixed phases TiO₂ with hollow interior was successfully fabricated via a Topotactic synthetic method, including the synthesis of CaTiO₃ precursors and transforming them into TiO₂ through ion-exchange process. The as-synthesized TiO₂ hierarchical architectures as the anode materials were used as lithium-ion batteries (LIBs). Compared with TiO₂ samples, the TiO₂@SnO₂-5% shows the improved lithium storage capacity, cycling performance and rate properties. The impedance of the TiO₂ electrode decreases evidently after adding few amount of SnO₂. The hollow hierarchical structure with different compositions provide much more active sites, and well connect interface among anatase, rutile, and SnO₂, facilitating the electron and ion transport quickly and efficiently. Addition appropriate number of SnO₂ not only well kept the hierarchical architecture but also enhanced the capacity and conductivity of the TiO₂ sample. As a result, TiO₂@SnO₂-5% exhibited excellent lithium storage performance.     

高效液相色谱法测定熟肉制品中8种合成着色剂

目的建立高效液相色谱法同时快速测定熟肉制品中8种合成着色剂的检测方法。方法称取粉碎后的样品于离心管中,加入碱性乙醇溶液提取合成着色剂,用硫酸溶液和钨酸钠溶液去除蛋白,滤液经浓缩后定容。样液过滤后经Agilent C18(5μm, 250 mm×4.6 mm)色谱柱分离,,流动相为0.02 mol/L NH4Ac(pH 6.86)和甲醇,流速为1.0mL/min,柱温40℃。采用二极管阵列检测器在254nm波长处进行检测,外标法定量。结果该方法在0.5～10.0 mg/kg线性范围内(靛蓝为1.0～20.0 mg/kg)线性良好,相关系数均大于0.990,检出限为0.1～1.0μg/kg,平均回收率为80.8%～104.7%,相对标准偏差为4.29%～4.87%。结论该方法操作简单、灵敏度高、重复性好,满足同时检测熟肉制品中8种合成着色剂的要求。     

军用涤纶长丝面料热转移印花及功能整理研究

介绍涤纶长丝面料分散染料热转移印花工艺,包括工艺流程、主要技术创新、产品应用等方面。阐述涤纶长丝面料阻燃涂层整理技术,并讨论阻燃剂用量、涂层增重量对整理效果的影响。总结防热红外侦察整理、防雷达波侦察整理、多功能迷彩面料生产及要点。文章表明,化纤长丝纺织产品的发展与国防建设是密切相关、相互促进、相辅相成的。以化纤长丝为基材生产的系列化军用产品是建设强大国防的重要保障。不断深化化纤长丝面料的功能性深度加工具有非常重要的意义。