Existence of Matrix-Valued Multiresolution Analysis-Based Matrix-Valued Tight Wavelet Frames

In this article, we introduce and study the matrix-valued tight wavelet frames for analyzing matrix-valued signal based on matrix-valued multiresolution analysis (MMRA). We put our emphasis on the existence of the MMRA-based matrix-valued tight wavelet frames by establishing the correspondence with their the unitary extension principle (UEP). Here in particular we introduce the square brackets product and the quasi-interpolatory operator, which makes the certificating process for UEP become relatively simple. Some interesting byproducts, such as features on the quasi-interpolatory operator 𝒫_n in the matrix-valued function space case, are the critical foundation for our main work.     

圆锥形血管中的振荡发展流动

本文在小锥度角的假设下,研究了圆锥形血管的非定常振荡的发展流动问题.导得了相应的速度分布公式.分析表明,所有收缩的圆锥形血管的流动都是发展流动,而且锥度角对发展流动的影响随着锥度角的增大而增大.     

Developing flows and developed flows

This paper puts emphasis on the problem of the developing flows in the circular tube under oscillatory conditions. According to the Navier-Stokes' equations and using the method of Bessel function of imaginary argument, a system of formulas is obtained. Comparing the formulas obtained in this paper with Atabek's formulas, it may be seen that the former is simpler and more convenient. When both the formulas obtained in this paper and Atabek's formulas are reduced to the representation of developed flows, both of them are consistent. Numerical calculation results show that the computed results obtained in this paper are rather consistent with both Atabek's computed results and the experimental results.     

含缺陷结构的塑性极限分析

结合极限分析中的数学规划理论和有限元技术,提出了三维含结构极限分析的数学规划方法,并采用罚函数法引入塑性不可压条件,对于考虑多组独立变化载荷作用的情况,提出了加载路径射线辐射求解方案,并基于这种射线射状的加载路径,推导了多组载荷联合作用下结构塑性极限上限分析的数学规划格式,编制了相应的有限元程序,文中的数值了该方法的正确性与有效性。     

First Total Synthesis of (±)-13-Hydroxyneocembrene

First total synthesis of (±)-13-hydroxyneocembrene ( 1 ), starting from 6-methyl-5-hepten-2-one ( 6 ) and geraniol ( 7 ), is described. The key steps are (i) the addition of sulfur-stabilized carbanion 12 to aldehyde 9 , (ii) the synthesis of 18 by using phase-transfer catalyzed coupling reaction, and (iii) low-valent titanium-induced intramolecular coupling of oxo aldehyde 3 to afford the target molecule after the final deprotection.     

一类实奇芽等价的充要条件

给定一自反的Ｂａｎａｃｈ空间Ｘ．在ｃ^∞函数芽环∈（Ｘ）中,任何在原点Ｏ∈Ｘ的实奇芽ｆ,若其二阶Ｆｒｅｃｈｅｔ导数ｆ″（０）＝Ｔ是一个Ｆｒｅｄｈｏｌｍ算子,则它同构于形如：1/2+g(v)的一个芽．如果代替ｇ以一个与之同构的芽ｇ_１,显然得到一个与原来的芽同构的芽．然而,其逆是否真呢？本文将证明其逆命题亦真     

Investigating particle and volatile evolution during pulverized coal combustion using high-speed digital in-line holography

Devolatilization is an important process in pulverized coal combustion because it affects the ignition, volatile combustion, and subsequent char burning and ash formation. In this study, high-speed digital in-line holography is employed to visualize and quantify the particle and volatile evolution during pulverized coal combustion. China Shanxi bituminous coal particles sieved in the range of 105–154 µm are entrained into a flat flame burner through a central tube for the study. Time-resolved observations show the volatile ejection, accumulation, and detachment in the early stage of coal combustion. Three-dimensional imaging and automatic particle extraction algorithm allow for the size and velocity statistics of the particle and stringy volatile tail. The results demonstrate the smaller particle generation and coal particle swelling in the devolatilization. It is found that the coal particles and volatiles accelerate due to the thermal buoyancy and the volatiles move faster than the coal particles. On average, smaller particles move faster than the larger ones while some can move much slower possibly because of the fragmentation.     

四种藏药成方制剂中铅、砷含量的湿法消化-流动注射氢化物发生-原子吸收光谱法测定研究

选择藏族地区常用的四种藏药成方制剂安置精华散、当佐、仁青常觉和七十味珍珠丸作为研究对象,通过优化消化条件和测定条件,探索建立其铅、砷含量测定的湿法消化与流动注射氢化物发生-原子吸收光谱(FI-HAAS)联用分析方法,并对其铅砷含量进行精确测定。在优化的工作条件下,铅和砷的检出限分别为：0.067和0.012 μg·mL-1;定量限分别为：0.22和0.041 μg·mL-1;线性范围分别为：25～1 600 ng·mL-1(r=0.999 5),12.5～800 ng·mL-1(r=0.999 4);精密度(RSD)分别为：2.0%和3.2%;加标回收率范围分别为：98.00%～99.98%和96.67%～99.87%。四种藏药成方制剂的铅、砷含量测定结果如下,安置精华散中铅砷含量分别为：0.63～0.67和0.32～0.33 μg·g-1;当佐为：42.92～43.36和24.67～25.87 μg·g-1;仁青常觉为：1 611.39～1 631.36和926.76～956.52 μg·g-1;七十味珍珠丸为：1 102.28～1 119.27和509.96～516.87 μg·g-1。本研究建立了藏药成方制剂中铅、砷检测方法,并测定了四种藏药成方制剂中铅、砷含量,为其在临床安全有效使用提供了参考依据。     

CMOS-compatible light-emitting devices based on thin aluminum nitride film containing Al nanocrystals

Electroluminescence (EL) from Al-rich AlN thin films grown on p-type Si substrate by radio frequency (RF) magnetron sputtering has been observed at room temperature. The light-emitting structure based on the thin films can be driven by an electrical pulse as short as 10⁻⁵ s. No obvious change in the light emission intensity was observed after 10⁶ pulse cycles. It has been found that the light emission intensity increases with the Al concentration. It is shown that the phenomenon is due to the enhancement of the percolative conduction via the Al nanocrystals distributed in the AlN matrix as a result of the increase in Al concentration.     

沉积速率和氧分压对HfO2薄膜残余应力的影响

采用ZYGO MarkIII-GPI数字波面干涉仪对以K9玻璃为基底的电子束蒸发方法制备的HfO₂薄膜中的残余应力进行了研究,讨论了沉积速率、氧分压这两种工艺参量对HfO₂薄膜残余应力的影响.实验结果表明：在所有的工艺条件下,薄膜的残余应力均为张应力;随着沉积速率的升高,氧分压的减小,薄膜的堆积密度逐渐增大,而残余应力呈减小趋势.同时用X射线衍射技术测量分析了不同工艺条件下HfO₂薄膜的晶体结构,探讨了HfO₂薄膜晶体 关键词： 残余应力 2薄膜')" href="#">HfO₂薄膜 沉积速率 氧分压