超疏水纳米结构表面池沸腾特性

本文通过采用物理气相沉积法于TiO2纳米管阵列表面修饰一层聚四氟乙烯(PTFE)纳米颗粒,得到超疏水表面,并研究此超疏水纳米结构表面的池沸腾特性.研究表明,超疏水纳米结构表面沸腾特性类似于膜沸腾,沸腾工质难以浸润该表面,其沸腾传热系数及临界热流密度均较低.分析表明,固液处于Cassie-Baxter接触状态,纳米结构表...     

关于厄米特矩阵的一个不等式

<正> 文献 [1] 中叙述了厄米特矩阵的一个重要性质:设 A_1,A_2,…,A_k 是 k 个 n 阶正定厄米特矩阵,则有     

相干态Jaynes—Cummings模型中场的振幅N次方压缩

研究了一初始处于基态的二能级原子与相干态光场相互耦合的单光子Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ（Ｊ－Ｃ）模型中场的振幅Ｎ次方压缩特性，并讨论了其压缩度随光场的初始平均光子数ｎ和压缩阶数Ｎ的变化。     

Ar—N2系统的相互作用势研究和输运系数计算

对ＢＯＷＥＲＳ等人的Ａｒ－Ｎ２相互作用势进行了修正，并利用量子力学的ＩＯＳＡ方法计算了Ａｒ在Ｎ２气体中的扩散系数和粘滞系数。结果表明，输运系数的计算结果，与实验数据的符合程度得到了明显改善。     

用于印刷电路板缺陷检测的光学视觉

本文提出了一种利用光学形态变换探测印刷电路板缺陷的新方法。以非相干光学相关器为基础,构成了一个实现印刷电路板微小缺陷检测的形态变换光学视觉系统给出了原理性实验结果。     

Problem of invariant subspaces in C*-algebras

Let A be a separable simple C*-algebra. For each a(≠0) in A, there exists a separable faithful and irreducible * representation (π, Hπ) on A such that π(a) has a non-trivial invariant subspace in Hπ.     

高阶非保守系统的2π-周期解

本文利用L~2-空间中的紧嵌入性质和 Schauder不动点原理,讨论了高阶n-维非保守系统: x~(k+1)+sum from j=1 to k (D_jx~(j)+g(t,x,x’,…,x~((m)))=p(t)2π-周期解的存在性问题。所得结果限制在k=1,m=0时,推广了文[1,2]中的相应结论。     

The interstellar methanol masers and their environments

To promote the understanding of massive star formation processes, we have studied the 6.6 GHz methanol (CH3OH) masers and their environments-- the dense cores and the outer regions of the molecular cloud. The physics of the CH3OH maser or the thermal emission formation region is studied by fitting the observational data of the 6.6 GHz 51-60 A+ and the 107 GHz 31-40 A+ CH3OH maser emission, using the radiative transfer calculations. The type II characteristics of the 6.6 GHz CH3OH maser are confirmed by the calculation results. A greater intensity of the radiation field leads to an increase in the peak intensity of the maser; however, high densities tend to turn off the maser. The calculation results show that to be a maser the 6.6 GHz CH3OH emission needs a radiation field of 150-300 K and a density not higher than 107cm-3, while the 107 GHz emission requires a radiation field of 210-300 K and a density not higher than 3×106 cm-3. The 6.6 GHz line is maser towards all six studied sources, while the 107 GHz line is maser towards Cep A only. Moreover, the former's intensity is much stronger than the latter. The radiative transfer calculations also indicate that the 6.6 GHz maser emission is so strong that the requirements of its formation (e.g. The radiation field, the density and the kinetic parameters) can only be satisfied at a certain stage of the processes of the massive star formation. Therefore it is often used as one of the most prominent tracers for the massive star formation regions. The calculation results of the simultaneous observations of (1,1) through (4,4) inversion lines of the ammonia (NH3) indicate that both the temperature and the density in the 6.6 GHz CH3OH maser formation regions are higher than that of the NH3 line formation regions. Furthermore, the common fact of |Vlsr(CO)| ＞ |Vlsr(NH3)| ＞ |Vlsr(CH3OH 6.6GHz maser)| in all six sources implies the ongoing developing trends of those gas flows driven by the masers.