籽粒苋蛋白质功能特性的理论研究(II)—籽粒苋蛋白质发泡性的理论研究

采用碱性提取和等电点法分离出籽粒苋蛋白质 ,测定了不同浓度、pH值、离子强度、蔗糖浓度条件下的蛋白质发泡力和泡沫稳定性 ,探讨了籽粒苋蛋白质在不同条件下发泡性的变化规律 ,为籽粒苋蛋白质在食品加工中的应用提供了一定的理论依据。     

Prickly Ni3S2 nanowires modified CdS nanoparticles for highly enhanced visible-light photocatalytic H2 production

The photocatalytic water splitting strategy is one of the most promising ways to achieve clean and renewable solar-to-hydrogen energy conversion. In this study, a highly enhanced photocatalytic H₂ production system has been achieved, using CdS nanoparticles (NPs) decorated on prickly Ni₃S₂ nanowires (NWs) as the light-driven photocatalyst. The photocatalyst was prepared by a co-precipitated method in which spiky Ni NWs were employed as starting material for prickly Ni₃S₂ NWs. Characterization analysis (XRD, TEM, XPS, etc.) show the high purity of Ni₃S₂/CdS hybrid structures and the well deposition of CdS NPs on prickly Ni₃S₂ NWs. Besides, the as synthesized Ni₃S₂/CdS photocatalyst exhibit reduced photoluminescence peak intensity, which means the Ni₃S₂ NWs functions as electron collector and transporter to quench the photoluminescence of CdS. This prickly Ni₃S₂/CdS nanocomposite demonstrates a 70 times higher H₂ production rate than that of pure CdS and a quantum efficiency of 12.3% at the wavelength of 400 nm in the absence of noble metals. This enhanced H₂ production activity is better than the one of CdS loaded with 0.5 wt% Pt. Our findings highlight the potential application of Ni₃S₂/CdS hybrid structures for visible light photocatalytic hydrogen yielding in the energy conversion field.     

Synthesis of NiS coated Fe3O4 nanoparticles as high-performance positive materials for alkaline nickel-iron rechargeable batteries

In this paper, ethyl xanthate nickel (EXN) was used as nickel and sulfur sources to modify Fe₃O₄ powder nanoparticles dissolved in pyridine. After short heat treatments, the generated NiS nanoparticles were not only compactly and uniformly coated on the surface of Fe₃O₄ but also induced the decreased particle size of Fe₃O₄. The microstructure, morphology and particle size of the resulting NiS coated Fe₃O₄ particles were characterized X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Raman spectroscopy. The results showed that thickness of the NiS coating on Fe₃O₄ particles was about 6 nm. The NiS coated Fe₃O₄ particles were tested as positive materials for nickel-iron batteries and found to effectively inhibit the iron anode passivation and improve the efficiency of charge capacity. The NiS (1.5%) – Fe₃O₄ nanoparticles delivered a significant power density of 557.2 mA h g^?1 at a current density of 120 mA g^?1, with a charging efficiency of 79.6%. Furthermore, discharge capacities of 550.2 and 436.8 mA h g^?1 were achieved respectively at 300 and 600 mA g^?1, with charging efficiencies reaching up 85.9% and 76.5% of the initial capacity after 100 cycles.     

2-氨乙基十七烯基咪唑啉缓蚀性能评价

实验以二乙烯三胺和油酸为原料,经升温脱水合成咪唑啉缓蚀剂。以正交试验法和静态失重法研究了以油酸和二乙烯三胺为反应物、二甲苯为携水剂合成咪唑啉缓蚀剂时在模拟采出水中其反应物配比、合成温度、合成反应时间对咪唑啉缓蚀剂缓蚀性能的影响。经红外光谱、咪唑啉缓蚀性能实验表明,其最佳合成反应条件为:n(油酸):n(二乙烯三胺)=1.0:1.0、合成温度为170℃,反应时间为8 h,此时缓蚀效率最佳达95%;实验室评价结果表明:该种缓蚀剂的最佳使用温度为50℃,当质量浓度为250 mg/L时缓蚀率可达96%;腐蚀试片腐蚀形貌分析可知,该种缓蚀剂能抑制点蚀;通过添加不同浓度缓蚀剂电化学曲线实验表明,该种缓蚀剂为混合型缓蚀剂。     

Preparations and photocatalytic hydrogen evolution of N-doped TiO2 from urea and titanium tetrachloride

Nitrogen (N)-doped TiO₂ samples with high specific surface areas were directly prepared by heating the mixture of urea and TiO₂, where the TiO₂ was obtained with titanium tetrachloride as precursor. The absorption spectrum of the N-doped TiO₂ shifted to wavelength up to 600 nm with increasing urea contents. X-ray photoelectron spectroscopic measurements showed that the N presented in TiO₂ was in the state of both molecularly chemisorbed N₂ and substituted N. While both of them contribute to the response to visible light, the latter gave the prepared samples with hydrogen evolution under visible light. The apparent photocatalytic activity of water splitting demonstrated as high amount of H₂ evolution was partly due to the phase transformation from anatase to rutile for the N-doped TiO₂.     

Impedance Characteristics of Closed Elliptic-Groove Waveguide for Millimeter Waves

A characteristic equation and impedance characteristic for the dominant mode of closed elliptic-groove guide have been analyzed and discussed by using the mode-matching method. The reference size of the closed elliptic-groove guide for the good impedance matching with rectangular guide in actual application is given. The obtained conclusions are of important significance in theoretical studies and actual applications of closed elliptic-groove guide for millimeter waves.     

小直径炸弹控制技术研究

对美国小直径炸弹的总体布局及控制系统进行了研究,给出了滑翔段和俯冲攻击段的弹道分析及制导律的设计.最后,给出了数学仿真结果.     

以铬酸盐阴离子柱撑镁铝水滑石为前体的脱氢催化剂研究

用离子交换法合成铬酸盐阴离子柱撑镁铝水滑石作为催化剂前体,由焙烧前体制备一系列不同原子比的铬镁铝复合氧化物;通过XRD、DTA、TGA、BET等对其进行初步表征,并考察其对二氧化碳氧化丙烷制丙烯反应的催化性能,结果表明：Cr：Mg：Al(原子比)为1．25：2：1的复合氧化物催化活性较好,在反应条件下,C3H8的转化率为23．3％,对C3H6的选择性为80．1％。     

Synthesis and interlayer modification of RbLaTa2O7

A layered semiconductor, lanthanum tantalum oxide was prepared by solid reaction at high temperature, and the processes for the modification of the interlayers by protonation, intercalation and pillaring were investigated. n-Butylamine could easily be intercalated into the interlayers of HLaTa₂O₇ to significantly enhance the interlayer distance, which facilitated the exchange of cation with n-butylamine. Finally, CdO pillars in the interlayer of lanthanum tantalum oxide were formed via calcinating at 500°C in air.     

基于磁流变制动器的自供能式汽车线控制动系统的设计与分析

磁流变液是近年来研究的热点,如今汽车线控技术的不断成熟和发展,利用传感器,控制元件,电子元件驾驶员动作转化为电信号,通过电线传递指令来操纵汽车,而不再需要传统的复杂的机械和液压连接装置.针对新型智能流体材料——磁流变液,我们将其应用于汽车线控制动系统中.利用磁流变液的这一特性设计出的制动器,再辅以合理的控制和信息反馈系统,可以实现制动力与地面附着力的快速匹配,甚至可以完成连续精准无脉动的ABS制动过程,从而代替传统液压机械式ABS,有利于实现底盘集成控制,大幅改善车辆制动性能.