Studies on Bioactive Selenium-containing Organophosphorus Compounds: Synthesis of 1-Aminoalkanephosphonate Derivatives of Benzisoselenazolone and Their Antitumor Activity

Various selenium-containing compounds are widely used as reagents and intermediates in organic synthesis.¹ In recent years biologically active organoselenium compounds have begun to attract considerable interest due to their unique and diverse potential pharmacological importance such as broad spectrum antitumor and antiviral activities, and some of them are even many times more active than their thio analogues.^2,3 It was found that benzisoselenazolones[e.g.,Ebselen, 2-phenyl-1,2-benzisoselenazol-3(2H)-one], are effective for the treatment of diseases caused by cell damage owing to increased formation of active oxygen metabolites⁴ and these pharmacological effects are mainly attributed to the glutathione peroxidase (GSH-Px) like properties.⁵     

Improved adaptive-threshold burst assembly in optical burst switching networks

An improved adaptive-threshold burst assembly algorithm is proposed to alleviate the limitation of conventional assembly schemes on data loss and delay. The algorithm will adjust the values of assembly factors according to variant traffic regions. And the simulation results show that, by using the adaptive-factor adaptive assembly scheme, the performance of networks is extensively enhanced in terms of burst loss probability and average queuing delay.     

Bidirectional passively mode-locked soliton fiber laser with a four-port circulator

We present an all-fiber bidirectional passively mode-locked soliton laser with what we believe is a novel cavity configuration. Using a four-port circulator, we incorporate two different semiconductor saturable absorber mirrors (SESAMs) into the laser cavity, which enables bidirectional mode locking. The laser allows the generation of two independent countercirculating mode-locked pulse trains, each with an individual fundamental repetition rate that can be adjusted by varying the SESAM pigtail length. Two countercirculating pulse trains with repetition rates of 21.3 and 15.2 MHz are obtained simultaneously. By controlling the intracavity loss imposed on these two pulse trains, either one of the two pulse trains can be switched on or off. The bidirectional operation with other repetition rates is also demonstrated.     

电热法测固体比热容实验的改进

探讨了电热法测固体的比热容实验装置的改进,并介绍用自补偿方式消除系统误差的方法,用集成温度传感器AD590测量温度,通过模拟电路调零和放大,其温度由数字毫伏表直接显示,用不锈钢真空杜瓦瓶代替量热器。     

Growth of Sb(2)E(3) (E = S, Se) polygonal tubular crystals via a novel solvent-relief-self-seeding process

A novel solvent-relief-self-seeding (SRSS) process was applied to grow bulk polygonal tubular single crystals of Sb(2)E(3) (E = S, Se), using SbCl(3) and chalcogen elements E (E = S, Se) as the raw materials at 180 degrees C for 7 days in ethanol solution. The products were characterized by various techniques, including X-ray powder diffraction (XRD), scanning electronic microscope (SEM), transmission electronic microscope (TEM), electronic diffraction (ED), and X-ray photoelectron spectra (XPS). The calculated electrical resistivities of the tubular single crystals in the range 20-320 K were of the order of 10(5)-10(6) Omega cm for Sb(2)S(3) and 10(3)-10(4) Omega cm for Sb(2)Se(3), respectively. The studies of the optical properties revealed that the materials formed had a band gap of 1.72 eV for Sb(2)S(3) and 1.82 eV for Sb(2)Se(3), respectively. The optimal reaction conditions for the growth of bulk tubular single crystals were that the temperature was not lower than 180 degrees C and the reaction time was not shorter than 7 days. The possible growth mechanism of tubular crystals was also discussed.     

基于局部Gabor二进制模式的高光谱伪装目标图像分类

为提高光谱伪装目标图像分类精度,提出了一种基于局部Gabor二进制模式（LGBP)的空间分类方法。LGBP作为一种多尺度算法,被用来提取高光谱图像的纹理特征。然后高光谱图像中的每一个像元可以用一个光谱特征向量及一个纹理特征向量表示。通过这种方法,增大类间距离。最后使用多核支持向量机结合光谱信息和空间纹理信息实现对高光谱伪装目标图像的分类。实验证明了该方法的有效性,分类总体精度和Kappa系数分别达到了95.6%和0.937。所提出的方法对于提高分类精度及鲁棒性具有重要意义。     

蚯蚓诱导-黑麦草吸收土壤Cd的相关性研究

利用石墨炉(GF-990)原子吸收法,对蚯蚓诱导条件下黑麦草对土壤Cd吸收规律进行了研究.结果表明:(1)在3～6 mg·kg-1的Cd浓度范围内,黑麦草地下部分Cd含量与蚯蚓数量呈极显著正相关(γ=0.8832*～0.9862**),黑麦草地上部分Cd含量与蚯蚓数量的正相关性不显著(γ=0.3455～0.325 4);而土壤Cd含最与蚯蚓数量之间呈显著的负相关性(r=-0.5887～-0.6784*).(2)在相等数最的蚯蚓条件下,随着土壤中Cd浓度增加,黑麦草地上、地下部分Cd的含量均升高.(3)在相同的土壤环境下,蚯蚓数量与蚯蚓体内Cd含量呈极显著负相关(r=-0.982 0**～-0.9916**).     

基于串联哑铃型微环谐振腔的二维相干光码分多址编解码器

利用微环谐振腔阵列进行光码分多址编解码过程中,微环谐振腔反射谱的自由频谱宽度(FSR)范围制约该系统用户容量的提升.本文提出了一种新型的基于游标效应的串联哑铃型微环谐振腔光编解码器.利用Matlab建立了半径分别为40μm-30μm-40μm的哑铃型微环谐振腔光编解码器模型.详细分析了光反射谱伪模抑制与耦合系数的关系,研究了耦合系数、码片速率对串联哑铃型微环谐振腔光编解码器性能的影响.结果表明,与半径分别为40μm-40μm-40μm的传统串联微环谐振腔编解码器相比,哑铃型微腔编解码器FSR值扩大了4倍.理想情况下,用户容量可呈指数增长.同时,互相关峰值比(P/W)与自相关峰值旁瓣比(P/C)分别提高了约33%和8%.     

超声集成双水相体系提取石榴皮中总生物碱的研究

研究了石榴皮中总生物碱的提取工艺并对其含量进行测定.以酸性染料比色法为分析手段,通过正交试验,探讨了影响总生物碱提取率因素的范围和最佳组合.石榴皮中总生物碱的最佳提取工艺条件为:硫酸铵8.0g、丙醇用量20 mL、醇水比为0.8∶1的双水相体系、超声时间60 min.在此条件下,石榴皮中总生物碱的平均提取率为0.559 mg/g,平均回收率为100.8％.     

A Smoothing Newton Method for Semi-Infinite Programming

This paper is concerned with numerical methods for solving a semi-infinite programming problem. We reformulate the equations and nonlinear complementarity conditions of the first order optimality condition of the problem into a system of semismooth equations. By using a perturbed Fischer–Burmeister function, we develop a smoothing Newton method for solving this system of semismooth equations. An advantage of the proposed method is that at each iteration, only a system of linear equations is solved. We prove that under standard assumptions, the iterate sequence generated by the smoothing Newton method converges superlinearly/quadratically.