500 kV超高压变电站综合自动化系统应用

0 引言 LSA678分布式变电站综合自动化系统集变电站的监测、控制、继电保护和防误闭锁于一体,在功能上又相互独立.通过灵活的配置与组态,能满足各种电压等级的有人或无人值班变电站自动化的要求,已成功应用于浙江金华500 kV双龙变电站.     

力学系统的自适应性——系统科学引起物理学的新思考(Ⅱ)

本文按着笔者《新思考(Ⅰ)》中提出的基本原理,建立以自适应性为基础的力学,使经典力学的各种现象和规律得到了统一的解释。这将有利于科学的逻辑统一,体现了系统科学对力学的影响和推进。     

金属超微粒子的气体蒸发法制备技术

本文介绍了用气体蒸发法制备金属超微粒子的实验技术。在He、Ne和Ar三种不同气体中,用蒸发法制备了A1、Zn、Cu、Mg、Fe、Co、Ni等七种金属超微粒子,分析了粒径与制备条件的关系。     

Transesterification of rapeseed oil catalyzed by liquid organic amine in supercritical methanol in a continuous tubular‐flow reactor

The catalytic activity of four liquid organic amines, triethylamine (TEA), diethylamine (DEA), ethylenediamine (EDA) and monoethanolamine (MEA), in the transesterification reaction of rapeseed oil in supercritical methanol was studied in this paper. The results showed that the order of the catalytic activity was DEA > TEA > MEA > EDA. The effect of the molar ratio of methanol to oil on the reaction was involved. Further, with TEA as the catalyst, the effect of the reaction pressure on this reaction was investigated. Pressure had a positive effect on this reaction. Additionally, the efficiency of the co‐solvent, including ethyl acetate, propylene oxide, tetrahydrofuran and cyclohexanone, was studied, showing that ethyl acetate had a positive effect on this reaction. The overall results suggested that the methyl ester yield in a continuous reactor was inferior to that in a batch reactor, mainly because of the poor mutual solubility between the oil and methanol. Furthermore, possible mechanisms for this amine‐catalyzed reaction were proposed.     

Transesterification of the crude Jatropha curcas L. oil catalyzed by micro‐NaOH in supercritical and subcritical methanol

Transesterification of the crude Jatropha curcas L. oil catalyzed by micro‐NaOH in supercritical/subcritical methanol was studied. The effects of various reaction variables such as the catalyst content, reaction temperature, reaction pressure and the molar ratio of methanol to oil on the conversion of crude Jatropha curcas L. oil to biodiesel were investigated. The results showed that even micro‐NaOH could noticeably improve this reaction. When NaOH was added from 0.2 to 0.5 to 0.8 wt‐‰ of triacylglycerols, the transesterification rate increased sharply; when the catalyst content was further increased, the reaction rate was just poorly improved. It was observed that increasing the reaction temperature had a favorable influence on the methyl ester yield. For the molar ratio ranging from 18 to 36, the higher the molar ratio of methanol to oil was charged, the faster the transesterification rate seemed. At the fixed stirring rate of 400 rpm, when the catalyst content, reaction temperature, reaction pressure and the molar ratio of methanol to oil were developed at 0.8 wt‐‰ NaOH, 523 K, 7.0 MPa and 24 : 1, respectively, the methyl ester yield could reach 90.5% within 28 min. Further, the kinetics of this reaction was involved and the results showed that it was a pseudo‐first‐order reaction whose apparent activation energy was 84.1 kJ/mol, and the pre‐exponential factor was 2.21×10⁵.     

Effect of cation doping on the structure of hydroxyapatite and the mechanism of defluoridation

The structure of three cation-doped hydroxyapatite filter materials with different cation radii and valence states, aluminum-doped hydroxyapatite (Al-HA), magnesium-doped hydroxyapatite (Mg-HA) and lanthanum-doped hydroxyapatite (La-HA), were studied to explore the performance and possible mechanism of defluoridation by means of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM)/Energy-dispersive X-ray spectroscopy (EDS), BET and Zeta potential analysis. The results demonstrated that cation doping with different radii could weaken lattice structure of hydroxyapatite, increase content of hydroxyl group and improve exchange ability with fluoride ions. However, the decisive factor affecting the capacity of fluoride removal was valence state of doped ion, because defluoridation capacity of Al-HA and La-HA with trivalent cations were larger than Mg-HA with bivalent cation. In addition, other studies related to the process of defluorination were carried out. The mechanism of defluoridation mainly included physical adsorption and chemical adsorption. First, F^- was deposited on the surface of the filter material by physical adsorption. After F^- diffused into the voids of the filter interval, and underwent ion exchange and complexation with -OH functional group in the lattice. Cation-doped hydroxyapatite structure and mechanism of fluoride removal were of great significance in the field of environmental governance.     

Excellent performance of gas sensor based on In2O3-Fe2O3 nanotubes

In₂O₃-Fe₂O₃ nanotubes are synthesized by an electrospinning method. The as-synthesized materials are characterized by scanning electron microscope and X-ray powder diffraction. The gas sensing results show that In₂O₃-Fe₂O₃ nanotubes exhibit excellent sensing properties to acetone and formaldehyde at different operating temperatures. The responses of gas sensors based on In₂O₃-Fe₂O₃ nanotubes to 100 ppm acetone and 100 ppm formaldehyde are 25 (240℃) and 15 (260℃), and the response/recovery times are 3/7 s and 4/7 s, respectively. The responses of In₂O₃-Fe₂O₃ nanotubes to 1 ppm acetone (240℃) and formaldehyde (260℃) are 3.5 and 1.8, respectively. Moreover, the gas sensor based on In₂O₃-Fe₂O₃ nanotubes also possesses an excellent selectivity to acetone and formaldehyde.     

催化裂化反再系统腐蚀影响分析

随着原料性质不断变化以及硫质量分数的增加（由原来的0.4％上升至0.9％）,导致催化裂化装置反再系统设备和管线腐蚀速度加剧.为及时掌握反再系统设备和管线的腐蚀情况,对催化裂化装置反再系统腐蚀机理、易腐蚀部位及防护措施进行了分析,另外也对催化裂化装置反再系统易发生腐蚀部位进行了案列分析并提出了相应的防护措施.近两年来装置反再系统腐蚀有所控制,实现装置连续两年长周期运行.     

基于PowerBuilder的软件重用研究

研究了基于PowerBuilder软件的重用技术,通过PowerBuilder对象重用、全局函数重用和外部对象重用这三个方面实现软件重用,应用PowerBuilder软件重用技术能提高软件开发效率,设计出高质量、低成本的软件系统。     

山东土堆—沙旺金矿床矿体特征及成矿规律浅析

土堆—沙旺金矿床位于胶莱盆地东北缘,是牟平—即墨成矿带的重要组成部分。矿区出露地层以古元古代荆山群和中生代莱阳群为主,断裂十分发育,区内主要工业矿体均产于早期形成的NE向次级断裂中。由于受低角度伸展断裂的控制,本区土堆西成矿带(Q2号矿带)、土堆成矿带(46号矿带)、沙旺成矿带(28号矿带)和沙旺东成矿带均表现出等距性展布的特征,矿化强弱带相间展布,间距为500～700 m,各成矿带内矿体定位具有北东浅、南西深的特点。野外工作发现,沙旺矿带深部-500 m标高以下可能存在第三矿化富集带,今后应重点加强该部位的探矿工作。本区矿床成因属于中低温热液构造裂隙充填型。