Comparative Study on Three Different Systems of Chemiluminescence Flow‐Injection Determination of Leucogen

Abstract

The effects of three systems on the chemiluminescence (CL) intensity have been studied in this paper, such as leucogen–potassium permanganate–rhodamine B, leucogen–cerium (IV)–rhodamine B, and leucogen–luminol–hydrogen peroxide (called system 1, system 2, and system 3, respectively). The mechanism of these reactions is also discussed. Surfactant (CTMAB) has a remarkably sensitive effect on these systems mentioned above. Therefore, three new flow injection chemiluminescence methods for the determination of leucogen have been established. For system 1, the linear range is 8.0×10^?8 to 4.0×10^?5 g mL^?1, with limits of detection 2×10^?8 g mL^?1; the relative standard deviation is 2.5% (n=11, Cs=4.0×10^?6 g mL^?1). For system 2, the linear range is 1.0×10^?8 to 5.0×10^?6 g mL^?1, with limits of detection 3×10^?9 g mL^?1; the relative standard deviation is 5.1% (n=11, Cs=1.0×10^?6 g mL^?1). For system 3, the linear range is 4.0×10^?8 to 2.0×10^?6 g mL^?1, with limits of detection 1×10^?8 g mL^?1; the relative standard deviation is 1.3% (n=11, Cs=1.0×10^?7 g mL^?1). Compared with the three methods above, system 3 is confirmed as the best method. This method has been applied to the determination of leucogen with satisfactory results.     

Investigation on diffraction characteristics of continuous terahertz beam limited by hard-edge apertures

Hard-edge apertures are common devices in optical systems. The light beam would be diffracted while transmitting through an aperture. The diffraction characteristics of terahertz (THz) beam passing through two hard-edge apertures have been simulated based on the Fresnel diffraction integral function, and an approximate parallel beam has been obtained. The effect on the diffraction spot has been compared and analyzed by changing the aperture diameter and distance between the two apertures and the diffraction plane. Then the experimental results were presented, which basically accorded with the numerical results. It can be inferred that the diameter of THz beam diminishes and the divergence angle can be neglected after the restriction of two apertures. The method is preferably available in some experiments which require small beam diameter and divergence angle.     

大气信道简化单次散射模型

采用椭球坐标系研究非直视日盲紫外光通信的单次散射模型,求解过程中要对有效散射体的体积进行复杂的数值积分并确定三组积分限。为便于分析,使用近似表达式极大简化了复杂单次散射信道模型,得出路径损耗是收发机几何结构与大气散射吸收系数的函数。对传输距离和路径损耗的仿真证明,该近似表达式与原始模型的所得结果吻合很好。利用该近似表达式,分别仿真分析了大气能见度对紫外光通信系统路径损耗和误码率的影响,仿真结果表明,大气能见度并不是越高越好,而是在能见度为10 km时紫外光通信系统有最佳性能。     

截断非傍轴双曲余弦-高斯光束的远场特性

基于瑞利-索末菲衍射积分公式,推导出截断非傍轴双曲余弦-高斯光束在自由空间传输的解析表示式,分析了一些特例,并引入非傍轴范畴的桶中功率概念,用以描述非傍轴光束的远场光束质量。结果表明:截断非傍轴双曲余弦-高斯光束的光强和桶中功率不仅与束腰宽度与波长之比、偏心参数及截断参数有关,而且桶中功率还与桶的尺寸有关。在一定的范围内,较大的束腰宽度与波长之比, 截断参数和较小的偏心参数使光束有更好的聚焦特性,表现出更好的光束质量。     

Differential-Operator Representations of S n and Singular Vectors in Verma Modules

Given a weight of sl(n, \mathbb C{\mathbb C}), we derive a system of variable-coefficient second-order linear partial differential equations that determines the singular vectors in the corresponding Verma module, and a differential-operator representation of the symmetric group S _n on the related space of truncated power series. We prove that the solution space of the system of partial differential equations is exactly spanned by {σ(1)|σ ∈ S _n }. Moreover, the singular vectors of sl(n, \mathbb C{\mathbb C}) in the Verma module are given by those σ(1) that are polynomials. The well-known results of Verma, Bernstein–Gel’fand–Gel’fand and Jantzen for the case of sl(n, \mathbb C{\mathbb C}) are naturally included in our almost elementary approach of partial differential equations.     

Single-frequency Brillouin distributed feedback fiber laser

We demonstrate a single-frequency Brillouin distributed feedback laser (DFB). The DFB laser cavity was a 12.4 cm long fiber Bragg grating with a π-phase shift offset from the grating center. It exhibited a threshold of 30 mW and conversion efficiency from pump to Stokes wave as high as 27%. Higher-order Stokes waves were suppressed by more than 20 dB. The Stokes output of the laser could be obtained in either the forward or backward direction, simply by changing the orientation of the offset of the discrete phase shift with respect to the pump propagation direction. The DFB laser operated over a pump frequency range of 1.2 GHz, more than 60 times larger than the SBS gain bandwidth.     

Fine Control of Polyester Properties via Epoxide ROP Using Monomers Carrying Diverse Functional Groups

Synthetic biodegradable polymers are important biomaterials. However, most of them are biologically inert. Free functional groups can allow easy biofunctionalization. Efficient introduction of functional groups to biodegradable polymers is still a challenge. Here, a practical strategy is presented to synthesize various functional polyesters with free hydroxyl groups polymerized via epoxide ring‐opening polymerization between dicarboxylic acids and diglycidyl dicarboxylates without protection and deprotection. The polymers exhibit a wide range of physical, thermal, and mechanical properties, and good cytocompatibilities. This synthetic platform is expected to lead to functional polymers useful for a wide variety of biomedical applications.

     

Phytochemicals and biological studies of plants from the genus Balanophora

This review focus on the phytochemical progress and biological studies of plants from the genus Balanophora (Balanophoraceae) over the past few decades, in which most plants growth in tropical and subtropical regions of Asia and Oceania, and nearly 20 species ranged in southwest China. These dioeciously parasitic plants are normally growing on the roots of the evergreen broadleaf trees, especially in the family of Leguminosae, Ericaceae, Urticaceae, and Fagaceae. The plants are mainly used for clearing away heat and toxic, neutralizing the effect of alcoholic drinks, and as a tonic for the treatment of hemorrhoids, stomachache and hemoptysis. And it has been used widely throughtout local area by Chinese people.Cinnamic acid derivative tannins, possessing a phenylacrylic acid derivative (e. g. caffeoyl, coumaroyl, feruloyl or cinnamoyl), which connected to the C(1) position of a glucosyl unit by O-glycosidic bond, are the characteristic components in genus Balanophora. In addition, several galloyl, caffeoyl and hexahydroxydiphenoyl esters of dihydrochalcone glucosides are found in B. tobiracola, B. harlandii, and B. papuana. Other compounds like phenylpropanoids, flavonoids, terpenoids and sterols are also existed. And their biological activities, such as radical scavenging activities, HIV inhibiting effects, and hypoglycemic effects are highlighted in the review.