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排序方式: 共有552条查询结果,搜索用时 12 毫秒
1.
应用M68HC908LJ12设计单相复费率电能表 总被引:2,自引:0,他引:2
介绍了以Motorola公司的M68HC908LJ12高性能单片机为CPU的单相复费率电能表的硬、软件设计和抗干扰设计。 相似文献
2.
采用高精度数字温度传感器LM74和数字语音芯片ISD25120厦无线电收发模块设计了一种带语音功能的可遥控测温仪。文中介绍了测量记录仪的设计与应用,包括高精度数字温度传感器LM74的特点及其与单片机的接口技术,介绍了软件设计流程,并给出了部分参考程序。 相似文献
3.
用微分电容法研究质子辐照HCl氧化物铝栅MOS结构诱导的界面陷阱,栅氧化层在1 160℃很干燥的、含0~10%HCl的气氛中热生长而成,质子辐照能量为120~300keV,注入总剂量范围为8×10~(13)~1×10~(16)p/cm~2。结果表明,辐照诱导的界面陷阱能级密度随质子能量、剂量增加而增加。然而,氧化层中掺入6%HCl时,辐照诱导的界面陷阱明显减少。这样,已能有效地改变MOS器件的抗辐照性能。实验结果可用H~+二级过程解释。 相似文献
4.
本文分析了MC68HC908QT4单片机键盘模块的结构原理和寄存器功能,结合其键盘模块的特点,给出了具体的键盘应用实例。 相似文献
5.
FTIR spectroscopy was applied to study the initial steps of ethylene polymerization on reduced chromia-silica (0.5 wt% Cr/SiO2). To decrease the speed of the reaction small doses of gas were introduced to the catalyst in each run and C2D4 was used to confirm band assignments. At the initial steps of the reaction only ethylene molecules coordinated to probably Cr
A
2+
cations were observed. The concentration of such complexes was estimated to be about 50% of the total amount of Cr atoms in the sample. The FTIR spectrum of the polymer formed at the initial doses of C2H4 (when [C2H4] [Cr]) was found to be slightly different from that formed after excess ethylene was introduced onto the catalyst ([C2H4] > [Cr]). 相似文献
6.
Yana Y. Toporkova Elena O. Smirnova Natalia V. Lantsova Lucia S. Mukhtarova Alexander N. Grechkin 《International journal of molecular sciences》2021,22(9)
The CYP74 clan cytochromes (P450) are key enzymes of oxidative metabolism of polyunsaturated fatty acids in plants, some Proteobacteria, brown and green algae, and Metazoa. The CYP74 enzymes, including the allene oxide synthases (AOSs), hydroperoxide lyases, divinyl ether synthases, and epoxyalcohol synthases (EASs) transform the fatty acid hydroperoxides to bioactive oxylipins. A novel CYP74 clan enzyme CYP440A18 of the Asian (Belcher’s) lancelet (Branchiostoma belcheri, Chordata) was biochemically characterized in the present work. The recombinant CYP440A18 enzyme was active towards all substrates used: linoleate and α-linolenate 9- and 13-hydroperoxides, as well as with eicosatetraenoate and eicosapentaenoate 15-hydroperoxides. The enzyme specifically converted α-linolenate 13-hydroperoxide (13-HPOT) to the oxiranyl carbinol (9Z,11R,12R,13S,15Z)-11-hydroxy-12,13-epoxy-9,15-octadecadienoic acid (EAS product), α-ketol, 12-oxo-13-hydroxy-9,15-octadecadienoic acid (AOS product), and cis-12-oxo-10,15-phytodienoic acid (AOS product) at a ratio of around 35:5:1. Other hydroperoxides were converted by this enzyme to the analogous products. In contrast to other substrates, the 13-HPOT and 15-HPEPE yielded higher proportions of α-ketols, as well as the small amounts of cyclopentenones, cis-12-oxo-10,15-phytodienoic acid and its higher homologue, dihomo-cis-12-oxo-3,6,10,15-phytotetraenoic acid, respectively. Thus, the CYP440A18 enzyme exhibited dual EAS/AOS activity. The obtained results allowed us to ascribe a name “B. belcheri EAS/AOS” (BbEAS/AOS) to this enzyme. BbEAS/AOS is a first CYP74 clan enzyme of Chordata species possessing AOS activity. 相似文献
7.
8.
Influence of expandable graphite on fire resistance and water resistance of flame-retardant coatings 总被引:1,自引:0,他引:1
Expandable graphite (EG) coating and ammonium polyphosphate-pentaerythritol-melamine (APP-PER-MEL) coating were prepared. Thermal degradation and char formation of the coatings were investigated by differential thermal analysis (DTA), thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results have shown that the anti-oxidation and fire-resistant properties of expandable graphite coating containing EG with size of 74 μm are better than those of APP-PER-MEL coating. The static immersion test was applied to study water resistance of the coatings, and the fire protection test and mechanical test were used to analyse heat insulation and mechanical properties of coatings before and after water immersion. The fire-resistant and mechanical properties of APP-PER-MEL coating were severely damaged by water immersion, whereas EG coating containing 8.5% EG with size of 74 μm could retain the good fire resistance even after 500 h water immersion. 相似文献
9.
V. A. Sadykov T. G. Kuznetsova V. P. Doronin E. M. Moroz D. A. Ziuzin D. I. Kochubei B. N. Novgorodov V. N. Kolomiichuk G. M. Alikina R. V. Bunina E. A. Paukshtis V. B. Fenelonov O. B. Lapina I. V. Yudaev N. V. Mezentseva A. M. Volodin V. A. Matyshak V. V. Lunin A. Ya. Rozovskii V. F. Tretyakov T. N. Burdeynaya J. R. H. Ross 《Topics in Catalysis》2005,32(1-2):29-38
Approaches to design of zirconia pillared clays via control of the properties of pillaring species in solutions were elaborated. Structural features of pillars and Pt + Cu active components fixed at these nanoparticles were shown to determine catalytic properties of pillared clays in NOx selective reduction by hydrocarbons in the oxygen excess. 相似文献
10.
NC74-1型氨合成催化剂的升温还原及应用 总被引:1,自引:0,他引:1
介绍了NC74-1氨合成催化剂在山东华鲁恒升化工股份有限公司大氮肥氨合成的装填、升温还原及使用情况。 相似文献