Characteristics and properties of metal aluminum thin films prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

Metal aluminum (Al) thin films are prepared by 2450 MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas. We focus our attention on the plasma source for the thin-film preparation and annealing of the as-deposited films relative to the surface square resistivity. The square resistivity of as-deposited Al films is greatly reduced after annealing and almost reaches the value of bulk metal. Through chemical and structural analysis, we conclude that the square resistivity is determined by neither the contaminant concentration nor the surface morphology, but by both the crystallinity and crystal size in this process.     

拟齐次核的 Hilbert 型重积分不等式最佳搭配参数的等价条件及应用*

利用权函数方法, 讨论拟齐次核Hilbert型重积分不等式的最佳搭配参数,得到最佳搭配参数的若干等价条件及不等式最佳常数因子的表达公式. 最后讨论其在奇异积分算子理论中的应用.     

一类非齐次核的Hilbert型级数算子最佳搭配参数的充要条件

选择搭配参数a,b,利用权函数方法,可得核为K(m,n)的级数算子T的不等式:‖T(?)‖₍p,β(a,b))≤M(a,b)‖?‖₍p,α(a,b)),?={a_m}一般地,M(a,b)并不是T:l_p~(α(a,b))→l_p~(β(a,b))的算子范数,针对非齐次核K(m,n)=G(m^λ₁/n^λ₂(λ₁λ₂>0),利用权函数方法讨论算子T的最佳搭配参数a,b的充分必要条件,并在a,b为最佳搭配参数时,得到了T的算子范数表达式.     

高维非线性时滞系统的稳定性

在自动控制、物理、生物、经济等不同学科的理论和应用中,经常需要研究带有时滞的动力系统的稳定性。文献[1]中,运用特征根法和V函数法对线性时滞系统给出了许多结果。至于高维变系数非线性时滞系统情形,进行研究则更为困难,目前尚无一般的有效方法,也很少见到简便实用的判据,本文不采用通常的(dV)/(dt)之判别法,也不引入条件,而直接利用线性型V函数[5]-[7]对一类高维变系数非线性时滞     

大学物理考核改革与能力、素质的量化原则初探

按照目前的共识，工科物理的教学改革应以提高学生的能力、素质(统称能力素质)为目的，特别是在如何提高学习能力、创造能力和科学素质等方面寻找突破口，为培养适应新世纪需要的现代工程人材探索实际可行的改革方案。而教学内容和课程体系的改革应该也必须包括对于考核方式方法的改革。     

力学问题中的估算方法

估算法是指在分析某些物理问题时,无需追求结果的精确性,而是忽略次要因素,突出主要矛盾,抓住问题的本质,充分运用物理规律和有关数学近似计算公式,对物理量的数量级进行快速计算和大致数据范围进行科学合理推算的方法.它不仅是一种常用的解题方法和思维方法,而且也是一种重要的科学研究方法.     

SLIP-LINE FIELD THEORY OF PLANE PLASTIC STRAIN DEALING WITH MOHR''''S CRITERION EXPRESSED BY QUADRATIC LIMITING CURVES

In this paper, the slip-line field theory of plane plastic strain dealing with Mohr's criterion expressed by quadratic limiting curves is preliminarily established. It takes the classical slip-line field theory as its special case, and it can be applied to the analysis of plane-strain problems in metal processing, rock and soil mechanics and tectonomechanics. As preliminary application, the slip-line field and limiting loads of flat punch indenting problem are determined by numerical solution, and the Slip-line field of bedded medium gravity-sliding problem is determined and discussed.