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961.
962.
Peifen Zhu Zhonghua Yu Guangmei Wan Huixin Sha Keman Su Bingyao Yu Guangsheng Zhao 《Journal of mass spectrometry : JMS》1991,26(6):613-618
N-Trifluoroacetyl-n-butyl ester derivatives of deuterium-labelled valine, leucine, isoleucine and phenylulanine were analysed by the isotope dilution technique and gas chromatography/mass spectrometry (GC/MS). Selected ion retrieval and peak-area integration were applied. The conditions adopted gave good separations with a short experimental time and high intensity. Ratios of the total isotopic abundance and metabolic kinetic curves were obtained. The regression coefficient of the standard dilution curve was 0.99 and the relative standard deviation was 0.3%. The stabilities of the amino acid derivatives were also tested. 相似文献
963.
Nanosized ZnGa2O4:Cr3+ powder is synthesized through hydrothermal method. The average particle size is 20 nm and they are spherical in shape. The excitation band from the charge transfer between Cr3+-O2− shows a blueshift behavior due to quantum confinement effect. X-ray diffraction pattern, Fourier transform-infrared spectrum, and electron paramagnetic resonance signal indicate that nanosized ZnGa2O4:Cr3+ phosphor shows many defect-related energy states and heavy lattice distortion in comparison with bulk ZnGa2O4:Cr3+ phosphor. Many defect states result in more nonradiative loss and shorter decay time. 相似文献
964.
Highly ordered Co0.71Pt0.29 alloy nanowire arrays have been fabricated successfully by direct current electro-deposition into the pores of a porous anodic aluminum oxide (AAO) template. SEM and TEM images reveal that the nanowires of array are uniform, well isolated, and parallel to one another. The aspect ratio of nanowires is over 200. XRD and EDS pattern indicates that amorphous Co0.71Pt0.29 structure was formed during electro-deposition. In amorphous sample, magnetocrystal anisotropy is very small, therefore, shape anisotropy plays a dominant role which leads to strong perpendicular anisotropy. High coercivity (Hc=1.7 kOe) and squareness (Mr/Ms) around 0.7 were obtained in the samples when the field was applied parallel to the axis of the nanowires. However, when it changed to polycrystalline structure after annealing, due to the competition of magnetocrystal anisotropy and shape anisotropy, the sample did not display perpendicular anisotropy. 相似文献
965.
HDPE based composites were produced with 10-20-30 and 40% composite mass of wood fiber. The coupling agents were epolene and
silane. The thermal behavior of composite samples was analyzed as a function of the coupling agent content, the exposure time
and the wood fibers content by means of differential scanning calorimetry. Calorimetric curves of all samples of first and
second heating shows a similar behavior. Some significant relation has been observed between the exposure time and the degree
of crystallinity for the same percentage of fiber samples. A linear relation between the melting enthalpy average vs. content
in cellulosic fibers is detected. Nevertheless, the fibers non-pretreated with coupling agent show a lower loss of crystallinity
of the HDPE matrix at low wood fiber content (10%). A slight diminution of the melting peak temperature is detected as increasing
the exposure time.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
966.
关于度量加的一个定理及一个矩阵不等式 总被引:4,自引:1,他引:3
关于度量加的一个定理及一个矩阵不等式苏化明(合肥工业大学数学力学系230009)§1关于度量加的一个定理R。Alexander在[1]中曾提出如下猜想:设两个单形的顶点分别为p_1,P_2,…,P_(n+1),和构作第三个单形,使得测应当有不等式这里... 相似文献
967.
Singular Points Near an X_0-breaking Double Singular Fold Point in Z_2-symmetric Nonlinear Equations
SingularPointsNearanX_0-breakingDoubleSingularFoldPointinZ_2-symmetricNonlinearEquationsSuYi(苏毅)andWuwei(吴微)(DepartmentofMathe... 相似文献
968.
系统可靠性与最优检测周期的综合研究 总被引:4,自引:0,他引:4
苏保河 《应用数学与计算数学学报》1998,12(1):29-36
本文研究可修系统的一个模型,假定系统可能因为各种原因造成失效率增大,并且这种情况需要检测之后才能发现,本文利用概率分析、补充变量和最优化方法,求出了系统的可靠性指标,并给出了计算最优检测周期的方法。 相似文献
969.
大孔膦酸树脂吸附钇的研究 总被引:6,自引:0,他引:6
大孔膦酸树脂吸附钇的研究舒增年熊春华(丽水师范专科学校化学系浙江323000)林峰(杭州大学化学系杭州310028)关键词大孔膦酸树脂钇吸附机理中图分类号O614.322本文在HAc-NaAc体系中,研究了树脂吸附钇的性能及其机理,获得了诸多的结果,... 相似文献
970.
文献[1],[2],[3]中讨论了Rn上的局部Hardy空间,并利用乘子定理证明了hp(Rn)=Fp.20(Rn).本文利用Chebyshev等式及正则函数的性质证明了在局部域上有类似的结果hp(Rn)=Fp.20(Rn),从而建立起函数空间之间的关系,并由此给出一个乘子定理. 相似文献