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1.
通过剖析4n阶和4n+1阶自补图之间的关系,应用度序列的方法,以4n阶自补图为基础,给出了构造4n+1阶自补图的递推方法。  相似文献   

2.
在 4N阶幻方构造研究的基础上 ,一种 4N阶幻立方构造方法被发现。介绍了 4N阶幻立方构造方法的论证  相似文献   

3.
在4N阶幻方构造研究的基础上,一种4N阶幻立方构造方法被发现.介绍了4N阶幻立方构造方法的论证.  相似文献   

4.
对Meyer-Knig and Zeller算子的4阶矩及6阶矩进行了研究,通过推导计算,给出了该算子4阶矩及6阶矩的估计结果.  相似文献   

5.
对Meyer-K(o)nig and Zeller算子的4阶矩及6阶矩进行了研究,通过推导计算,给出了该算子4阶矩及6阶矩的估计结果.  相似文献   

6.
使用Lagrange定理及n次对称群的基本概念证明了4次对称群存在且只存在30个子群,并给出了每个子 群.其中,除去两个平凡的子群,另有9个2阶循环群;4个3阶循环群;3个4阶循环群;4个Klein4元群;4个S3(在 同构意义之下);3个8阶子群以及1个12阶子群.  相似文献   

7.
24阶正交拉丁方的构造方法   总被引:1,自引:0,他引:1  
提出了一种4t 阶正交拉丁方法的构造方法,阐明了4t 阶正交拉丁方构造的思路,介绍了24阶正交拉丁方构造的基本步骤和构造结果。  相似文献   

8.
根据构造无反射数值边界格式的基本思想,采用多项式拟合的方法,构造了一种高精度的数值边界格式(SFEBS).理论分析表明:SFEBS边界格式与4阶紧致差分格式相结合,既能保持格式的G-K-S稳定性,又能保持三对角矩阵是严格对角占优的.数值试验表明:2阶和3阶边界格式分别能够保持3阶和4阶的整体精度;4阶的SFEBS格式也能够保持4阶的整体精度,同时能够减小自由流出边界上的最大误差.  相似文献   

9.
利用倒正交拉丁方,给出了关于2m 1阶幻方的和合成公式。另外,引入了幻方乘积的概念,给出了4m阶幻方的积合成公式;同时引入了加边幻方的定理,将4t阶幻方加边成4t 2阶幻方。  相似文献   

10.
利用4阶矩阵的2阶复合矩阵与其复合伴随矩阵的性质,给出一类4阶非对称、非反对称矩阵合同的充要条件.丰富了与已有2阶、3阶矩阵结构类似的矩阵合同的研究结果,得到对更高阶矩阵的类似讨论具有指向意义的研究方法.  相似文献   

11.
采用密度泛函理论B3LYP/6—311++g^**方法对[NH3(H2O)n]^-(n=2—4)团簇的结构和频率进行研究,从而得到[NH3(H2O)n](n=2—4)团簇的基态结构,得到的结构与SubhaPratihar等的研究一致.同时,文章还研究了水氨团簇的电子束缚方式和偶极矩,结果表明,在n=2时,电子束缚方式为表面束缚,而在n=3,4时,既有表面束缚方式,又有内部束缚方式.  相似文献   

12.
Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work the melt spun(Ni_(0.6)Nb_(0.4-y)Ta_y)_(100-x)Zr_x with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T 400 °C, even in a hydrogen atmosphere(1-10 bar), the amorphous structure was retained. The crystallization process was characterized by differential thermal analysis and the activation energy of such process was obtained. The hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method,and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear change of the hydrogen solubility was observed with the variation of the Zr content. The values of the hydrogenation enthalpy changed from ~37 k J/mol for x=30 to ~9 k J/mol for x=20. The analysis of the volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum of energy levels.  相似文献   

13.
本文记述采自云南东川市的舟形蝗属Lcmba Huang,1983一新种。本新种与舟形蝗属已知种的主要区别为:前翅较长,超过腹部第二节背板后缘;后足胫节淡黄绿色;雄性下生殖板末端微凹但不加宽。  相似文献   

14.
罗罹  吾国强  雷宏 《科技资讯》2009,(19):11-12
在管式反应器中,2-(4^1-乙基苯甲酰基)苯甲酸在发烟硫酸存在下闭环得到2-乙基蒽醌,发烟硫酸与2-(4^1-乙基苯甲酰)苯甲酸配比为2.4(ml):1(g),反应温度190℃,反应时间48.4s,收率91.5%。  相似文献   

15.
Bulk material of (Se80Te20)100 xAgx (0rxr4) system was prepared by using a conventional melt quenching technique. Thin films of a-(Se80Te20)100 xAgx (0rxr4) were deposited by the vacuum evaporation technique at a base pressure of 10 4 mbar onto well-cleaned glass substrates. Temperature dependence of electrical conductivity in the temperature range of 263–333 K has been studied. There is increase in the value of conductivity with increase in temperature as well as with Ag content. The measurements of intensity dependence of photoconductivity show that the photoconductivity increases with intensity as a power law where the power is found to be between 0.5 and 1.0, representing the continuous distribution of traps. Rise and decay of photocurrent with time at room temperature at different light intensities for (Se80Te20)98Ag2 thin film samples have also been reported. The results have been explained on the basis of the Dember voltage and interaction between photoexcited holes and the trapped electrons on the surface.  相似文献   

16.
Cu(In,Ga)Se2 (CIGS) thin films were prepared by directly sputtering Cu(In,Ga)Se2 quaternary target consisting of Cu:In:Ga:Se 25:17.5:7.5:50 at%. The composition and structure of CIGS layers have been investigated after annealing at 550 ℃ under vacuum and a Se-containing atmosphere. The results show that recrystallization of the CIGS thin film occurs and a chalcopyrite structure with a preferred orientation in the (112) direction was obtained. The CIGS thin film annealed under vacuum exhibits a loss of a portion of Se, while the film annealed under Se-containing atmosphere reveals compensation of Se. Several solar cells with three different absorber thicknesses were fabricated using a soda lime glass/Mo/CIGS/CdS/i-ZnO/ZnO:Al/Al grid stack structure. The highest conversion efficiency of 9.65% with an open circuit voltage of 452.42 mV, short circuit current density of 32.16 mA cm2 and fill factor of 66.32% was obtained on a 0.755 cm2 cell area.  相似文献   

17.
陈余陆  汪明 《科技资讯》2009,(19):170-170
根据活性亚结构拼接原理,利用aza-Wittg法合成5-氨基-2-苯氨基噻唑-4-苯甲酸乙酯化合物,通过1HNMR,EI-MS分析等方法对合成的化合物进行了结构表征。  相似文献   

18.
SnS is a promising Ⅳ-Ⅵ semiconductor,which is very less explored for diluted magnetic semiconducting and dielectric applications.In this study,the Ni doping(x_(Ni)=0-10mol%) effects on SnS host lattice were investigated.A simple and low cost co-precipitation technique was employed to grow Ni doped SnS powders.The X-ray diffraction confirmed single phase orthorhombic structure with a nano-crystalline nature that was further verified through the surface structure observed by scanning electron microscopy.Near edge x-ray absorption fine structure spectroscopy revealed a shift in the Ni absorption edge towards higher energy,depicting the formation of Ni~(+3) oxidation state.The impedance measurements,in the frequency range 1 kHz to 20 MHz,depict that owing to the excellent sensitivity to the electromagnetic radiations at the low energy,the Ni doped SnS finds potential applications in various energy related devices.Vibrating sample magnetometer measurements have elucidated room temperature ferromagnetism,which depicts potential memory device applications.  相似文献   

19.
Poly(3,4-propylenedioxythiophene)/nano-Zinic Oxide(PProDOT/ZnO) composites with the content of 3-7 wt%nano-ZnO were synthesized by the solid-state method with FeCl3 as oxidant.The structure and morphology of the composites were characterized by Fourier transform infrared(FTIR)spectroscopy,ultraviolet-visible(UV-vis) absorption spectroscopy,X-ray diffraction(XRD) and transmission electron microscopy(TEM).The electrochemical performances of the composites were investigated by galvanostatic charge-discharge,cyclic voltammetry and electrochemical impedance spectroscopy(EIS).The photocatalytic activities of the composites were investigated by the degradation of methylene blue(MB) dyes in aqueous medium under UV light irradiation.The results from FTIR and UV-vis spectra showed that the PProDOT/ZnO composites were successfully synthesized by solid-state method,and nano-ZnO had great influences on the conjugation length and oxidation degree of the polymers.Furthermore,the PProDOT/5 wt%ZnO had the highest conjugation and oxidation degree among the composites.The results of XRD analysis indicated that there were some FeCl4- ions as doping agent in the PProDOT matrix,and the content of ZnO had no effect on diffraction pattern of PProDOT.Morphological studies revealed that the pure PProDOT and composites had similar morphological structure,and all the composites displayed an irregular sponge like morphology.The results of electrochemical tests showed that the PProDOT/5 wt%ZnO had a higher electrochemical activity with a specific capacitance value of 220 F g-1 than others.The results from photocatalytic activities of the composites indicated that the PProDOT/5 wt%ZnO had better photocatalytic activity than other composites.  相似文献   

20.
富勒烯C_(100)及其衍生物C_(100)X_4的理论研究   总被引:1,自引:1,他引:0  
在混合密度泛函B3LYP理论下,用6-31G*基函数对富勒烯C100分子的6个能量较低异构体及基于能量最低异构体衍生物C100X4(X=H,F,Cl,Br)的几何结构、电子结构进行了研究.计算结果表明:D2C100是最稳定的,C100X4(X=H,F,Cl)的形成均为放热反应.振动频率计算表明,C100X4(X=H,F,Cl,Br)均是势能面上的稳定驻点,C100F4在所研究的簇分子中是较为稳定的,应该能够合成出来.  相似文献   

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