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991.
Liu Yang Pengfei Yu Wenyuan Li Fengliang Cao Xin Jin Sheng Xue Xianglong Zhang Tingwei Zhang Mingbo Wu Wenting Wu 《American Institute of Chemical Engineers》2022,68(9):e17760
Hydrogen peroxide (H2O2) has been listed as one of the 100 most important chemicals in the world. However, huge amount of residual H2O2 is hard to timely decomposed into O2 and H2O under acidic condition, easily resulting in explosion hazard. Here, we reported a core–shell structure catalyst, that is graphene with Co N structure encapsulated Co nanoparticles. Co N graphene shell serves as the active site for the H2O2 decomposition, and Co core further enhance this decomposition. Benefiting from it, the H2O2 decomposition were close to 100% after 6 cycles without pH adjustment, which increased 6 orders of magnitude compared with no catalyst. At the same time, the O2 generation reached 99.67% in 2 h with little metal leaching, and ·OH has been greatly inhibited to only 0.08%. This work can cleanly remove H2O2 with little deep oxidation and protect the process of H2O2 utilization to achieve a safer world. 相似文献
992.
Thomas C. Farmer Corinne L. Carpenter Michael F. Doherty 《American Institute of Chemical Engineers》2016,62(9):3505-3514
This article is motivated by a remarkable observation reported recently by Myerson, Trout, and co‐workers that continuous crystallization is capable of producing metastable polymorphs in stable steady‐state operation. We explain why this phenomenon occurs and give simple design rules for reproducing it in other polymorphic systems. A linear stability analysis gives simple functions of parameters for which one can continuously produce thermodynamically metastable products based only on the relative polymorph dynamics. We demonstrate agreement with two sets of experimental data; L‐glutamic acid grown from aqueous solution and p‐aminobenzoic acid also grown from aqueous solution. For many polymorphic compounds, engineering a process to produce a desired polymorph is as simple as finding a reasonable operating point for the continuous mixed‐suspension mixed‐product removal crystallization process (temperature, residence time, initial supersaturation, etc.) according to the rules reported in this article. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3505–3514, 2016 相似文献
993.
Laccase‐catalyzed synthesis of polypyrrole‐multiwalled carbon nanotube composites as energy storage materials for capacitors 下载免费PDF全文
Multiwalled carbon nanotubes (MWNTs) were coated with polypyrrole (PPy) using in situ enzymatic polymerization of pyrrole catalyzed by a laccase (benzenediol:oxygen oxidoreductase, EC 1.10.3.2) from Trametes versicolor. Transmission electron microscopy revealed that the MWNTs were uniformly coated with very thin layers of PPy without any indication of globular polymer aggregate formations. The enzymatic synthesis of the MWNTs/PPy composites was quite simple being performed in a one‐pot aqueous solution (pH 4.0) under mild reaction conditions. The potential of the composites with respect to the development of energy storage devices was demonstrated by fabricating a two‐electrode coin cell capacitor (diameter 20 mm, thickness 1.6 mm) utilizing the composites as electrode materials. The capacitance of the cell was 28.0 F g?1 for the electrode material as measured by a galvanostatic charge–discharge method. The energy density and power density were 2.55 and 805 W kg?1, respectively, which were close to those of the capacitors classified as ultracapacitors. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43307. 相似文献
994.
Ming Weng 《应用聚合物科学杂志》2016,133(16)
The Hansen solubility parameters (HSPs) are useful for predicting solvent–solute affinity. In this study, the HSPs and the sphere radii (Ro's) of poly(ether sulfone), bitumen, and lignin were determined by a novel optimization method. A hybrid algorithm, which could locate multiple optima, was developed and used to solve optimization problems for maximizing the fitness (F) and minimizing both Ro and the numbers of good solvent and total outliers. For most selected samples, improved results with higher F and reduced Ro and number of outliers were obtained. The results clarify the correlations among three criteria for an optimal solubility sphere, namely, the smallest Ro, highest F, and lowest number of outliers. They can be satisfied simultaneously only when outliers are avoided; otherwise, a reduction in Ro decreases F but can retain the same outliers. Thereby, defining the solubility sphere as the one having the smallest Ro and the lowest number of outliers is more reasonable according to the physical significance in both cases. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43328. 相似文献
995.
Effects of antimicrobial agents on the thermal and mechanical properties of acrylate hydrogel matrices 下载免费PDF全文
Polymer materials with antimicrobial activity are prepared by UV polymerization of acrylate and methacrylate mixture at room temperature. The antimicrobials are silver acetate and copper (II) acetate, used without pretreatment. Their chemical stability in the acrylate matrix and their effect on the thermal and mechanical properties of the polymer matrix are investigated as a function of their concentration up to 15 wt %. Physico‐chemical, thermal, rheological, and morphological analyses as well as the surveillance of metal salts release in aqueous medium are conducted. A significant decrease in the thermal stability of the salts introduced into the acrylate matrix is observed after UV treatment. The metal salts also have significant effects on the properties of the matrix. A plasticization and densification of the material associated with an aggregation of salts up to the percolation at the highest concentration are highlighted. At equal concentrations, the effects are more pronounced in the presence of copper salts. The latter was released more slowly than silver salts from acrylate material. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43501. 相似文献
996.
Preparation and characterization of hyperbranched poly(ether sulfone) and its application as a coating additive for linear poly(ether sulfone) 下载免费PDF全文
Hyperbranched poly(ether sulfone) (HPES), a suitable coating additive for improving the rheological properties of linear poly(ether sulfone) (LPES), was easily produced via polymerization of commercially available bisphenol S (A2 monomer, BPS) and synthesized 2,4′,6‐trifluoro‐phenylsulfone (BB′2 monomer, TF). During this reaction, fluoro‐ or phenolic‐terminated HPES (F‐HPES or OH‐HPES) could be facilely obtained by controlling the feed mole ratios of the two monomers. The polymerization mode A2 + BB′2 was confirmed by analyzing the model compounds and the degree of branching (DB) was calculated systematically. In addition, the synthesized polymers' chemical structures were exhibited by FTIR, 1H NMR as well as 19F NMR spectroscopy. Notably, the addition of 1 wt % HPES reduced the melt viscosity and improved the high temperature liquidity of LPES because of its unique spherical shape. Furthermore, the addition of HPES did not have a negative impact on the performance of LPES, which was attributed to the good miscibility between HPES and LPES. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43892. 相似文献
997.
998.
本文研究了工业电解镍沉积层的微观组织随着生产时间变化的特征。利用XRD、SEM、EBSD等分析手段对电解镍板择优取向,微观形貌,特征晶界分布等随着生产时间变化的特征进行了研究。结果表明:电沉积镍板在表面上晶体主要以垂直于(200)面的方向生长,在截面上表现为(111)、(200)双择优取向,晶体生长方式为侧向生长。表面与截面表现出不同的微观形貌,表面上由棱锥状转变为胞状,生长机制由螺旋位错驱动生长变为原子聚集堆积长大;各阶段镍板截面形貌始终为层片状组织。沉积层中截面主要为大角度晶界,并产生大量的∑3孪晶界。稳定生长过程中,随着沉积进行大角度晶界比例逐渐下降,∑3晶界相对频率逐渐升高,但是它们都会受到电解槽环境变化的影响。在截面上沿着生长方向,电解镍板主要表现为<001>纤维织构,大量∑3孪晶界对沉积层取向产生影响。通过提高∑3孪晶界比例或选择∑3孪晶界较高频率所对应时间的电解镍,以此获得强度和塑性更优的电解镍。电解镍沉积层演变规律得以明确意味着在后期的研究或者指导工业生产中能够对电解镍的组织进行微观调控,实现工业条件下电解镍的订制生产。 相似文献
999.
助力实现双碳目标,促进西部地区新能源产业发展,以宁夏为例,探索与我国西部地区相适应的招商引资政策,并给出具有针对性的新能源产业招商引资建议。深入分析宁夏现有资源、招商引资现状与产业招商引资面临的挑战,总结出西部地区新能源产业招商的几大痛点:电气外送不足,企业需求不明,招商考核指标不匹配,产业链与招商链不适应,区域产业饱和。通过改进招商引资考核计量方法,降低相关制造业招商门槛,提高发电企业招商引资门槛,打造地区产业集群。提出产业距离的概念,通过量化产业距离明确招商引资顺序。以市场为导向,根据国家政策与当地项目确定招商引资总体方向。分析西部各省新能源产业发展情况,量化各省产业生态圈建设情况,确定跨省产业生态圈基本布局。结合地方优势产业,实现多产业融合,进一步促进新能源产业发展。 相似文献
1000.
工业自整定PID调节器关键设计技术综述 总被引:21,自引:1,他引:21
杨智 《化工自动化及仪表》2000,27(2):5-10
对十年来国内外在工业过程控制中使用的自整定PID调节的设计方法与关键技术进行了全面综述和评价,这对我国进行同类高科技自动化仪表的开发研制及商品化有重要的指导意义. 相似文献