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991.
Michael Thompson 《Trends in analytical chemistry : TRAC》2011,30(7):1168
Analytical chemists can advantageously use an uncertainty function to describe the performance of an analytical system in terms of the standard uncertainty or standard deviation as a function of the concentration of the analyte. This “characteristic function” is useful for estimating uncertainty at a new concentration. A similar function can be used to prescribe the uncertainty that is regarded as fit for purpose for a particular application. This “fitness function” is useful in setting standards of accuracy in proficiency tests and similar exercises without revealing the concentration of the analyte. In combination, these two functions provide a rational basis for method selection. 相似文献
992.
In this paper we show that the unit ball of an infinite dimensional function algebra has no strongly exposed points.
993.
加速管中的高次模(HOM)能导至累积束流崩溃,因此这些模式必须被抑制.在S波段直线对撞机中(SBLC),采用了在束流孔膜片上复盖适当的损耗材料的方式.HOM的Q值被减小了5倍,而基模的Q值几乎保持不变.3种材料被考虑,即:stainlesssteel,kanthal和galvedc为了对具有这种涂层的加速腔进行高功率测试,一个两腔的谐振器结构被设计.本文描述了高功率测试的原理,过程以及初步的结果. 相似文献
994.
In this paper,an initial boundary value problem with homogeneous Neumann boundary condition is studied for a reaction-diffusion system which models the spread of infectious diseases within two population groups by means of self and criss-cross infection mechanism. Existence,uniqueness and boundedness of the nonnegative global solution (u1,u2,u3,u4),existence of the limit of the solution as t→+∞,namely,(u1,u2,u3,u4)→(u*1,0,u*3,0),are proved. 相似文献
995.
Received September 24, 1998; accepted August 9, 1999 相似文献
996.
In the paper we construct a system of bounded functions which generates an uncomplemented subspace in the Lorentz space Λ(α)
for all α∈(0,1). Lower bounds of the norms of the projector onto such subspaces are obtained.
Translated fromMatematicheskie Zametki, Vol. 68, No. 1, pp. 57–65, July, 2000. 相似文献
997.
杨乐不等式的推广及加强 总被引:1,自引:0,他引:1
赵长健 《数学的实践与认识》2000,30(4)
本文首先利用凸函数基本不等式和平均值不等式推广并加强了杨乐不等式 ,然后利用 Jensen不等式给出了两个更为广泛的结果 . 相似文献
998.
Radar ambiguity function in Lp frame 总被引:1,自引:0,他引:1
QI Minyou 《中国科学A辑(英文版)》2000,43(8)
In modern radar techniques, pulse signal can be replaced by the chirps, which is taken to be signals in Lp space. Wigner's function and ambiguity functions are constructed in an Lp frame and a partial generalization of the uncertainty principle is given by means of the notion of coherent dual. 相似文献
999.
本文运用 Liapunov第二方法 ,研究了食饵有常数放养率的广义 Rosenzweig-Macarthur系统x=f ( x) -yφ( x) +H ,y=h( y) [-e+Kφ( x) ]唯一正平衡点的稳定性 .并利用 Poincare-Bendixon环域定理及张芷芬唯一性定理 ,论证了在 R+ 2 ={( x,y)∶x>0 ,y>0 }内极限环的存在唯一性及其稳定性 . 相似文献
1000.
Time evolutions of the droplet size distribution in miniemulsions, which is constituted of water/n-hexadecane/nonionic surfactants, were investigated by using light scattering techniques. A hard-sphere model is applied to
characterize the polydispersity of miniemulsion droplets. Measuring the relative scattering intensity as a function of the
volume fraction of dispersed phase, the variance of the droplets size distribution, σ2, was evaluated. Miniemulsions developed gradually from monodisperse systems (σ2 ≅0.02) to polydisperse ones (σ2 ≥0.13) over 12 days after preparation. σ2 increased rapidly in the early stage, and ceased to develop at about 6 days after preparation. The z-average hydrodynamic radius of miniemulsion droplets grew with time over the whole time range. The change with time of the
total droplet number of miniemulsion is in agreement with that predicted by Smoluchowski's theory for diffusion-controlled
coagulation. Although the characteristic coagulation time obtained here was much larger than that estimated by Smoluchowski's
theory, the qualitative agreement between the theory and the experimental results obtained here is good. At the earlier stage
of the destabilization process of miniemulsions, the growth mechanism of droplets may be explained in terms of a diffusion-controlled
coagulation.
Received: 1 April 2000 Accepted: 10 August 2000 相似文献