氧化钒制取碳化钒的热力学分析

采用热力学的方法对以五氧化二钒为原料制取碳化钒的工艺过程进行了分析,分析表明:钒氧化物的转化过程中遵守逐级还原理论。钒氧化物碳化过程中,不转化为金属钒,直接转化为碳化钒。在钒氧化物的转化过程中,应尽可能使其转化为二氧化钒。若采用气相还原碳化的方法,可通过调节气体的流量、配比、还原与碳化工艺参数进行质量控制。     

THE APPARENT VISCOSITY OF SEMI-SOLID AZ91D ALLOY AT STEADY STATE

The rheological behavior of semi-solid AZ91D at steady state is studied using a Couette type viscometer in the present paper. The results show that the apparent viscosity of semi-solid AZ91D at the steady state increases with the solid fraction increasing, and goes up sharply when the solid fraction reaches a certain value, which is called critical fraction. In addition, the apparent viscosity of semi-solid AZ91D at the steady state takes on a distinct downtrend with the shearing rate increasing, which indicates a strong shear thinning property. In addition, the critical solid fraction becomes higher under larger shearing rate, owing to the more globular shape of the solid particles. Based on the present experiment results, an empirical equation is built as that, relating the steady state apparent viscosity of semi-solid AZ91D with the solid fraction fs andshearing rate (?) at the same time: ηapp=10.74exp(6.95fs)(?)-0.86.     

MICROSTRUCTURE STUDY OF CONSTITUENT PHASES IN 2024 SERIES Al ALLOYS

X-ray microanalysis,convergent beam electron diffraction(CBD)and selected area electrondiffraction(SAD)studies on the structures and compositions of the constituent phases in2024 series Al alloys have been conducted.Partial substitution of alloying elements is found tooccur in all the constituent phases,which cause small deviations from the stoichiometric com-positions reported in these ternary compounds.The dominant phase is α-Al_(12)(FeMn)_3Si whichhas a body center cubic crystal structure with the Im■ space group and a=1.25 nm.The nextdominant phase is Cu_2FeAl_7 which has a primitive tetragonal crystal structure with theP4/mnc space group and a=0.6336 nm,c=1.487 nm.The minor phase is α'-Al_(12)Fe_3Si hav-ing α primitive cubic crystal structure with the Pm■ space group and α=1.27 nm.     

较小半径溢洪弯道急流超高的研究

为了探求急流弯道的超高及其相关的影响因素,通过对较小半径弯道急流的水流现象的描述,指出较小半径弯道凹岸水流受惯性离心力和冲击力的共同作用。在此基础上,利用动量原理,推导出了较小半径弯道水流超高公式,与试验资料对比,该理论的合理性得到了证实。还讨论了弯道水流各因素同超高的关系,结果表明,弯道的超高和宽度几乎成正比,弯道的转角影响超高很大,当弯道半径越小,其超高将增加越快。     

High-performance Multicrystalline Silicon Ingots Assisted by Recycled Multicrystalline Silicon Block Tailing as Seeds

Silicon - Nowadays, casted multicrystalline silicon is the most important material in photovoltaic industry. In order to reduce the cost of silicon ingots, the recycle of silicon ingot tailings is...     

10 kV变频器在输油站离心泵电机控制的应用

为了验证异步电机变频调速在输油站应用的实际应用效果,进行了变频调速泵(离心泵)的工作特性分析、运动流体的能量分析和电机功率因数的分析。然后,对某输油站串联安装且同时运行的变频离心泵和非变频(工频)离心泵近一年的运行数据进行分析验证。理论分析和数据统计分析的结果一致。结果表明异步电动机变频调速(降频)运行后,节能效果显著,且输油管道压力调节范围更大,提高了电机的功率因数。     

CFRP与金属结合件盐雾腐蚀试验研究

采用中性盐雾、乙酸盐雾、铜加速乙酸盐雾3种电化学方法研究碳纤维/环氧复合材料与CR4级冷轧钢板的电偶腐蚀行为.比较了CR4级冷轧钢板与碳纤维复合材料紧固件构成偶对时3种盐雾腐蚀试验的电偶腐蚀性能.结果表明在NaCl电解质溶液体系中电偶腐蚀作用对CFRP影响不大,CFRP基本没有受到腐蚀.     

关于核电厂附加柴油发电机低电压动作缺陷分析及处理

厂区附加柴油发电机组作为核辅助设备的后备电源,关系到整个核电机组的可靠性和安全性.对自动起励试验期间出现的低电压三取二保护误动的问题进行了PLC逻辑优化后,解决了由继电器固有的1.5～1.9 s延时特性与起励逻辑不匹配导致的厂区附加柴油机组不可用问题,保证了核电厂安全系统后备电源的可靠性和安全性.     

核电厂应急交流电源切换逻辑缺陷分析及处理

核电厂应急交流电源作为核辅助设备的应急电源,关系到整个核电机组的安全性和可靠性,能否正常响应切换电源关系到核电机组安全.对应急交流电源反切逻辑进行修改优化后,初步解决了应急交流电源切换后重要核安全辅助设备的供电问题,提高了核电厂安全系统应急电源的可靠性.     

In Vitro Characterization of Neutralizing Hen Antibodies to Coxsackievirus A16

Coxsackievirus A16 (CA16) is one of the major causative agents of hand, foot, and mouth disease (HFMD). Children aged <5 years are the most affected by CA16 HFMD globally. Although clinical symptoms of CA16 infections are usually mild, severe complications, such as aseptic meningitis or even death, have been recorded. Currently, no vaccine or antiviral therapy for CA16 infection exists. Single-chain variable fragment (scFv) antibodies significantly inhibit viral infection and could be a potential treatment for controlling the infection. In this study, scFv phage display libraries were constructed from splenocytes of a laying hen immunized with CA16-infected lysate. The pComb3X vector containing the scFv genes was introduced into ER2738 Escherichia coli and rescued by helper phages to express scFv molecules. After screening with five cycles of bio-panning, an effective scFv antibody showing favorable binding activity to proteins in CA16-infected lysate on ELISA plates was selected. Importantly, the selected scFv clone showed a neutralizing capability against the CA16 virus and cross-reacted with viral proteins in EV71-infected lysate. Intriguingly, polyclonal IgY antibody not only showed binding specificity against proteins in CA16-infected lysate but also showed significant neutralization activities. Nevertheless, IgY-binding protein did not cross-react with proteins in EV71-infected lysate. These results suggest that the IgY- and scFv-binding protein antibodies provide protection against CA16 viral infection in in vitro assays and may be potential candidates for treating CA16 infection in vulnerable young children.