Degenerate four-wave mixing based on excited-state absorption in azo-dye-doped polymer films

Degenerate Four-Wave Mixing (DFWM) based on excited-state absorption in azo-dye doped polymer films is firstly reported. Under a pre-exciting argon laser at 514.5 nm, DFWM is performed using a 632.8 nm HeNe laser which is absorbed only slightly when the molecules are in the ground state. The dynamic behavior of the DFWM signal due to excited-state absorption is also treated theoretically.     

BEHAVIOR AS t→∞ OF THE SOLUTIONS OF THE LINEAR SYSTEM OF ELASTIC THEORY ON NON－STAR－SHAPED EXTERIOR DOMAINS

（刘德辅）ＢＥＨＡＶＩＯＲＡＳｔ→∞ＯＦＴＨＥＳＯＬＵＴＩＯＮＳＯＦＴＨＥＬＩＮＥＡＲＳＹＳＴＥＭＯＦＥＬＡＳＴＩＣＴＨＥＯＲＹＯＮＮＯＮ－ＳＴＡＲ－ＳＨＡＰＥＤＥＸＴＥＲＩＯＲＤＯＭＡＩＮＳ￥ＬｉｕＤｅｆｕ（Ｄｅｐｔ．ｏｆＡｐｐｌＭａｔｈ．，Ｂｅｉ...     

A new thermochemical splitting cycle of sodium chloride for chlorine and sodium hydroxide production

A new thermochemical closed cycle of sodium chloride for the preparation of chlorine and sodium hydroxide is presented in this paper. The optimum conditions of the main reactions in the cycle were obtained from a series of experimental results. The heat flow of the cycle system was calculated based on the related thermodynamic equations and data. The kinetic study of the heterogeneous reaction in the cycle was carried out by means of a thermogravimetric method. The result shows that the proposed cycle demonstrates an obviously energy-saving advantage over all the other methods of chlorine and sodium hydroxide productions. It may become economically competitive with the current electrolytic method in the future.     

Identification of band structures in the 137La nucleus

High-spin states of ¹³⁷La have been investigated with the reaction ¹³⁰Te(¹¹B, 4n) at a beam energy of 50MeV. The level scheme of ¹³⁷La has been expanded with spin up to 33/2ℏ. Several new bands have been found in this nucleus. A band crossing in the band based on the 17/2^- level has been observed at a rotational frequency of ℏω ∼ 0.48MeV. From systematic comparison, this band crossing probably originates from the alignment of protons. One of the bands with strong M1 transitions is proposed as a collective oblate band ( γ ∼ -60^°).     

大型对称不定箭形线性方程组的分解方法

1 引言 首先考虑2×2矩阵 显然当k>1/2时,矩阵K是对称正定的,且K可以分解成Cholesky因子:当k=1/2时,K为奇异矩阵;而当k<1/2时,K为对称不定矩阵,这时K有广义Cholesky分解式:并且这种分解是稳定的,一般地我们给出定义 定义1.1 设有矩阵K∈R~((m+n)×(m+n)),若总存在排列矩阵P∈R~((m+n)×(m+n))和对称正定矩阵H∈R~(m×n)、G∈R(m×m)使得则称矩阵K为对称拟定(Symmetric quasidefinite)矩阵。     

Novel and Efficient Synthesis of DHPMs Catalyzed by di‐DACH‐Pyridylamide Ligands

Di‐DACH‐pyridylamide ligands, symmetrical bridged bis‐Schiff base, and spiro pyrrolizines as catalysts in the synthesis of dihydropyrimidinethiones (DHPMs) using the Biginelli reaction is first reported. This new protocol has the advantages of environmental friendliness, short reaction time, excellent yields, and simple post‐treatment procedure. A series of DHPMs were obtained in high yields (up to 98%) in only 6 h. Moreover, based on the optimized condition, a novel Biginelli‐like reaction was first developed.     

刚架结构变更定理与极限状态函数的连续生成

本文基于计算结构力学概念提出了刚架结构连续变更定理,用数值分析与递推公式相结合的方法连续生成结构极限状态函数,给出了结构退化为机构的新判据。由于引用了计算结构力学方法,重分析不必重新形成结构刚度阵,不必反复求逆矩阵,大大提高了计算效率。