二苯并噻吩合成方法的改进

对文献报道的由联苯和硫在AlCl3催化下反应合成二苯并噻吩(DBT方法中的提纯过程作了改进，大大简化了提纯步骤，使制备DBT的时间缩短了一半，产率为63．4％，经提纯后的成品含量达99．7％，其纯度、外观、晶相均优于进口试剂，但成本远低于进口试剂。产品用FT-IR、LRS、XRD和^1H NMR表征结果与文献报道完全相符合。     

Isotopic Oxygen Exchange and EPR Studies of Superoxide Species on the SrF2/La2O3 Catalyst

By using the in situ IR spectroscopy, the superoxide species (O₂⁻), characterized by the O–O stretching peak at 1130 cm⁻¹, was detected on the SrF₂/La₂O₃ catalyst at temperatures up to 973 K. The introduction of ¹⁸O₂ isotope caused the 1130 cm⁻¹ peak to shift to lower wavenumbers (1095 and 1064 cm⁻¹), consistent with the assignment of the spectra to the superoxide species. A good correlation between the rate of the disappearance of the O₂⁻ species and that of the formation of C₂H₄ was observed, suggesting that O₂⁻ was the active oxygen species responsible for the oxidative coupling of methane (OCM) on the SrF₂/La₂O₃ catalyst. This conclusion was reinforced by the EPR experiments (g_xx = 2.0001, g_yy = 2.0045, g_zz = 2.0685), showing that O₂⁻ was the only paramagnetic oxygen species detectable on the O₂-preadsorbed SrF₂/La₂O₃ catalyst. These results suggest that superoxide O₂⁻ can be a stable active oxygen species, whose role in the OCM reaction cannot be overlooked.     

高支化度酯类增塑剂的结构鉴定

利用AV50 0核磁共振波谱仪鉴定了一种从聚氨酯材料中分离出的增塑剂。这是一种新型的性能优良的耐迁移性脂肪族增塑剂。使用的手段有红外光谱 ,1 H NMR ,1 3C NMR ,1 3C 1 HCOSY ,1 H 1 HCOSY以及DEPT等技术。     

Durable antimicrobial treatment of cotton fabrics using N‐(2‐hydroxy)propyl‐3‐trimethylammonium chitosan chloride and polycarboxylic acids

N‐(2‐hydroxy)propyl‐3‐trimethylammonium chitosan chloride (HTCC), a water‐soluble chitosan quaternary ammonium derivative, was used as an antimicrobial agent for cotton fabrics. HTCC has a lower minimum inhibition concentration (MIC) against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli compared to that of chitosan; however, the imparted antimicrobial activity is lost on laundering. Thus crosslinking agents were utilized to obtain a durable antimicrobial treatment by immobilizing HTCC. Several crosslinkers such as dimethyloldihydroxyethylene urea (DMDHEU), butanetetracarboxylic acid (BTCA), and citric acid (CA) were used with HTCC to improve the laundering durability of HTCC treatment by covalent bond formation between the crosslinker, HTCC and cellulose. The polycarboxylic acid treatment was superior to the DMDHEU treatment in terms of prolonged antimicrobial activity of the treated cotton after successive laundering. Also, the cotton treated with HTCC and BTCA showed improved durable press properties without excessive deterioration in mechanical strength or whiteness when compared to the citric acid treatment. With the addition of only 0.1% HTCC to BTCA solutions, the treated fabrics showed durable antimicrobial activity up to 20 laundering cycles. The wrinkle recovery angle and strength retention of the treated fabrics were not adversely affected with the addition of HTCC. Therefore, BTCA can be used with HTCC in one bath to impart durability of antimicrobial activity along with durable press properties to cotton fabric. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1567–1572, 2003     

数字环境中的机构知识库研究略述

机构知识库（Institutional Repository,简称IR）,是伴随着开放获取运动出现的一个新概念,是数字学术环境中的一种资源存储形式和服务方式。综合国内外学者对IR的知识含义、特征、作用与意义的概述,以及国内外研究现状和IR发展中存在的问题,分析其与开放获取和数字图书馆的关系。     

碱体系中系列羟基苯基卟啉红外光谱和拉曼光谱性质研究

本文继续深入研究该体系中相关物质的红外光谱和拉曼光谱的性质.论文结果说明,在碱体系中,NaOH只与羟基苯基卟啉周边meso-位的羟基反应形成盐,这个性质与紫外可见光谱性质是一致的.同时这一结果也为研究卟啉与金属的相互作用提供了有益的理论支持.     

带有干扰观测器的凝视航天器姿态变结构控制

研究了实现对地凝视观测时的航天器姿态控制问题.首先介绍了对地凝视模式及其成像优点,继而推导出实现对地凝视的期望姿态四元数和期望角速度,在此基础上得到姿态相对动力学和运动学方程;考虑到提高凝视成像精度、延长成像时间的要求,设计了一种变结构控制律,并采用干扰观测器的方法来抑制变结构控制的固有振颤,提高控制效果,并对这种方法和传统控制方法进行了比较.仿真结果表明,在实现对地凝视的姿态控制过程中,设计的控制器响应速度更快,具有更好的鲁棒性,并减弱了变结构控制的振颤问题.     

纸浆漂白过程流中非过程铁元素的表征

以新制铁和陈化铁模拟纸浆漂白过程流中的非过程铁元素,研究了非过程铁元素存在颗粒的粒径大小和分布、表面形态和物象组成.研究发现,新制铁胶体颗粒以纳米级存在(210～250 nm),并随体系pH值增加而增加,其密度和体积分布呈双峰分布.70 ℃水浴加热1 h后,新制铁胶体颗粒粒径明显增加,pH 13时达到1 620 nm.陈化铁颗粒粒径较大,高达10 μm.IR、XRD、SEM-EDS分析表明,以新制铁形式的非过程铁胶体颗粒没有结晶成分存在,其宏观分子式为Fe29.1O17.2(OH)52.9;以陈化铁形式存在的非过程铁胶体颗粒主要以Fe2O3晶体存在,其宏观分子式为Fe34.7O38.8(OH)26.5.     

电气设备红外测温影响因数及温度修正

红外测温在电气设备温度测量的应用日趋广泛,但是测温精度易受外界干扰.研究了影响红外测温的3个主要因素,即设备发射率、大气衰减、环境因素,并提出了解决方法.通过实验采用修正算法得出了准确的温度数据,同时利用两种比较法来对修正后的温度进行判断.     

Applications of rheological torque–time curves to the study of thermooxidative degradation of polypropylene powder

The torque–time curves of polypropylene (PP) powder treated under various thermooxidative degradation conditions were obtained through processing in the mixing chamber of a rheometer. Meanwhile, the Fourier transform infrared (FTIR) spectra of the corresponding samples were determined, and the quantitative analysis of the carbonyl indices of the FTIR spectra of the samples of the PP powder was carried out to provide evidence for the rheological characterization. PP granules, to which an antideteriorant was added before they were commercially supplied so good antidegradation could be achieved, was investigated for the sake of contrast. The analysis of the experimental results showed that the height of the torque–time curve of the PP powder and the corresponding value of the equilibrium torque could be used to characterize or evaluate the variations of the thermooxidative degradation of the PP powder. Under the same processing conditions, the heights of the torque–time curves of the PP powder and the corresponding values of the equilibrium torque decreased with the enhancement of the thermooxidative degradation treatment before mixing; on the contrary, the heights and areas of the characteristic bands of the carbonyl groups in the FTIR spectra of the PP powder and the corresponding values of the carbonyl index increased. The quantitative analysis of the FTIR spectra provided evidence for the conclusion that the heights of the torque–time curves of the PP powder and the corresponding values of the equilibrium torque could be used to characterize or evaluate the thermooxidative degradation of the PP powder. If the treatment under thermooxidative degradation conditions weakened or the degradation of the PP powder just began (i.e., in the viscosity range for processability), the evaluation method using the heights of the torque–time curves of the PP powder or the corresponding values of the equilibrium torque could provide more sensitivity than the method using the values of the carbonyl index. Consequently, the method using the heights of the torque–time curves to evaluate the thermooxidative degradation of the PP powder had its advantages. The application of the torque–time curves could be used to evaluate not only the variation of the thermooxidative degradation of the PP powder treated under aging conditions before mixing but also the variation of the degradation, including the mechanochemical degradation, of the PP powder during the period of mixing. The dependence of the variation of the degradation of the polymer on the processing time during mixing could be evaluated by the study of the variation of the torque–time curves. It can be concluded that the application of torque–time curves to the evaluation of degradation of PP powder has the advantages of being convenient, real‐time, in situ, online, and production‐oriented. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007