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51.
利用米曲霉对牛乳进行发酵,通过单因子及正交试验以菌丝体干重为指标对其在牛乳中的生长进行了研究.结果表明:接种量为4%,装液量为30mL,摇床转速为180r/min时菌丝体干重可达到最大.此外测得最大菌丝体干重时的蛋白质分解率可达35.6%. 相似文献
52.
从提高太阳能电池板的输出功率出发,提出了基于双CPU控制方式的太阳能跟踪系统。系统采用俯仰-水平双轴控制,以单片机STC12C2052AD为光电控制单元的核心处理器,以混合式步进电机为执行机构,以TMS320F2812为核心控制器件的三相正弦波细分驱动器实现了混合式步进电机的精确定位。实验表明系统运行稳定,具有很高的实用价值。 相似文献
53.
54.
基于储氢合金的太阳能制冷系统理论研究 总被引:1,自引:0,他引:1
结合金属氢化物的特点,提出了一种新型太阳能吸附式制冷循环系统;具体介绍了系统结构形式,建立了系统能量转换与分析模型,并对构成系统的各部件进行了分析;根据具体算例,计算了系统各部件的效率与损失,结果表明,系统具有较好的节能效果,且系统优化应以太阳能辐射量为基准,以提高金属氢化物系统中的氢气转化率为目标进行。系统优化的另一方向在于发展与其他太阳能利用技术相结合的复合式系统。 相似文献
55.
为了能够提高风光互补发电机控制的效果,深入地研究了灰色预测PID在风光互补发电机控制中的应用.构造了风光互补发电机的数学模型;剖析了灰色预测的基本原理.针对风光互补发电机控制的实际情况,将灰色预测PID技术引入到风光互补发电机的控制中,提出了风光互补发电机灰色预测PID控制系统,并且提出了相应的算法流程;分别利用灰色预测PID控制技术、模糊PID控制技术和传统PID控制技术对风光互补发电机进行控制仿真研究,仿真结果表明灰色预测PID技术可以获得较好的控制效果. 相似文献
56.
A. Fernere L. Lestrade A. Rouanet A. Denoirjean A. Grimaud P. Fauchais 《Journal of Thermal Spray Technology》1994,3(4):362-370
An original process of superficial thermal treatment is described. This process has been successfully applied to partially
stabilized yttria-zirconia coatings (ZrO2-Y2O3) to increase the lifetime of the thermal barriers. A thin superficial layer was melted, and morphological transformations
were observed. A microstructural comparison between as-sprayed layers and thermally treated layers is presented. 相似文献
57.
ZO U Hongcheng DAI Shujuan QIAN Zhixiong LI Guangxia Huazhong University of Science Technology Wuhan China Originally published in ACTA METALL SIN 《金属学报(英文版)》1989,2(6):428-432
The change of microstructure of fatigue specimens before and after laser radiation was studiedby transmission electron microscopy.The results show that the diameter of dislocation cell λtends to a constant at fatigue failure.Based on the principles of continuous damagemechanics,expressions of the fatigue damage criterion and processes of fatigue damage evolu-tion for L Y12CZ have been derived. 相似文献
58.
Nanocrystalline titania films codoped with aluminum and boron were prepared by cathodic vacuum arc deposition. In the process, titanium alloy target was used under an O2/Ar atmosphere, and sensitization of films were carried out by natural dye-sensitized complex in anhydrous ethanol. The structure, surface morphology and UV-vis spectra of titania films codoped were measured by X-ray diffraction analysis, scanning electron microscopy and ultraviolet-visible spectrometer. Theas-deposited films are found to be amorphous. The films annealed were examinedto be of anatase structure with orientation along the (101) planes, the averagecrystal size is in the range between 41 and 45 nm. SEM results show that thereare some pores in the codoped titania films, the optical properties of the dye-sensitized films were also measured which reveals that the spectral responses of films shift to the visible region. Under simulated sunlight illumination, the overall energy conversion efficiency of dye-sensitized nanocrystalline solar cell is 0.9%. 相似文献
59.
H.?H.?ParkEmail author M.?H.?Lee J.?S.?Yoon I.?S.?Bae B.?I.?Kim 《Metals and Materials International》2003,9(3):311-317
STS310S and SC-STS310S (simultaneously co-deposited chromium and aluminum onto 310S austenitic stainless steel substrate by
pack-cementation process) were used as separator materials on the cathode side of a molten carbonate fuel cell. With the STS310S,
corrosion proceeded via three steps; a formation step of unstable corrosion product, a protection step against corrosion until
breakaway, and an advance step of corrosion after breakaway. The final corrosion product was LiFeO2 and the loss of mass was 6.5 mg/cm2 after a corrosion test of 480 hr at 650°C. The SC-STS310S showed more effective corrosion resistance, however, than did common
STS310S. There was especially no corrosion loss on the SC-STS310S after the 480 hr corrosion test. It is anticipated that
it will be very useful as an alternative separator on the cathode side off the MCFC in the future. 相似文献
60.
Calcium dynamics in a cardiac cell are described by a system of 3-D non-linear stochastic partial differential equations. To obtain solutions that have biophysical properties, it is necessary to explore the model parameter space. To decrease the complexity of the parameter search, we reduce the 3-D stochastic model to a 1-D deterministic model. The reduction of the problem from 3-D to 1-D is done through an asymptotic approximation after non-dimensionalization and based on rational biophysical assumptions of the 3-D domain; the stochastic to deterministic transformation is based on the regular property of the 3-D solution. The result of the model reduction proves very effective in reducing the time required to get qualitative as well as quantitative information about parameter regions in the 3-D stochastic model including calcium dynamics (sparks, wave propagation, and recovery) observed in cardiac cells. 相似文献