红外动态场景生成装置空间分辨率的测试

建立了一套基于刀口灰度图红外探测的实验装置,对红外场景生成器的空间分辨率进行了测试。首先通过被测红外场景生成器产生带有刀口标志的红外图像,然后利用红外热像仪采集红外场景生成器所成的红外图像,通过对采集到的红外热图的数据处理,实现了对红外场景生成器空间分辨率的测量。测得的红外场景生成器的空间分辨率为5lp/mm,标准误差为0.04。     

Microwave‐improved polymerization of ϵ‐caprolactone initiated by carboxylic acids

The ring‐opening polymerization of ε‐caprolactone (ε‐CL), initiated by carboxylic acids such as benzoic acid and chlorinated acetic acids under microwave irradiation, was investigated; with this method, no metal catalyst was necessary. The product was characterized as poly(ε‐caprolactone) (PCL) by ¹H NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet spectroscopy, and gel permeation chromatography. The polymerization was significantly improved under microwave irradiation. The weight‐average molecular weight (M_w) of PCL reached 44,800 g/mol, with a polydispersity index [weight‐average molecular weight/number‐average molecular weight (M_w/M_n)] of 1.6, when a mixture of ε‐CL and benzoic acid (25/1 molar ratio) was irradiated at 680 W for 240 min, whereas PCL with M_w = 12,100 and M_w/M_n = 4.2 was obtained from the same mixture by a conventional heating method at 210 °C for 240 min. A degradation of the resultant PCL was observed during microwave polymerization with chlorinated acetic acids as initiators, and this induced a decrease in M_w of PCL. However, the degradation was hindered by benzoic acid at low concentrations. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 13–21, 2003     

核内核子－核子非弹散射截面（Ⅰ）

在与平均场、核内核子－核子弹性散射截面以及输运方程相统一的理论框架内推导了核内核子－核子非弹散射截面的解析表达式．其数值结果能很好地重现自由非弹截面的实验值，所计算的有效非弹截面与Ｄｉｒａｃ－Ｂｒｕｅｃｋｎｅｒ的计算结果相一致．     

红外动态图像生成技术概念研究

红外动态图像生成技术的基本概念包括基本术语及其定义。为了描述红外动态图像生成技术的特性,通常采用如光源类型、光谱波段、阵列规模、空间分辨率、填充因子、时间常数、帧频、闪烁、温度范围、串扰、均匀性、发射率、辐射对比度、动态范围、温度分辨率、调制传递函数、几何畸变及最大温度和最大辐射强度等概念。介绍了描述红外动态图像生成系统性能的基本概念的定义。转换器的指标定义对于转换器的设计和性能指标的测试都有重要的意义。     

聚砜-尼龙6嵌段共聚物结构的研究

<正> 以金属钠作催化剂合成的聚砜-尼龙6嵌段共聚物对尼龙6的吸水性有一定的改善,而且可以作为聚砜与尼龙共混物的相容剂,但共聚物中聚砜组分的含量都不超过25％。这可能与共聚物的结构有关。近年来的工作表明:反相气相色谱法(IGC)是高聚物结构分析的有用的工具之一。我们试图用反相气相色谱法,通过观察嵌段共聚物     

Molecularly imprinted solid-phase extraction of (-)-ephedrine from Chinese Ephedra

Method of molecularly imprinted solid phase extraction (MISPE) of (-)-ephedrine from Chinese Ephedra has been developed in the research. The molecularly imprinted polymer (MIP) with good selectivity and affinity for (-)-ephedrine was synthesized with (-)-ephedrine as the template, methacrylic acid as the functional monomer. The washing and elution conditions in MISPE were selected and optimized for efficient analyte extraction and sample clean-up. A clean analytical HPLC base line of ephedra extract was obtained after MISPE, which indicated that the sample pre-treatment was efficient. Good recovery and precision were obtained in the assessment for the MISPE-HPLC procedure, which demonstrated it is a reliable method and can be used for the determination of (-)-ephedrine in herbal ephedra.     

铜在HOPG上电沉积过程的现场ECSTM研究

用自制的电化学扫描隧道显微镜（ＥＣＳＴＭ）现场研究Ｃｕ在ＨＯＰＧ上的电沉积过程．结果表明Ｃｕ在ＨＯＰＧ上的电沉积为三维成核的过程．当电位较低或Ｃｕ２＋离子浓度较低时，铜在本体金属生长主要沿着台阶方向．过电位较高时，铜的成核数目增加，沉积层的晶粒有所细化．同时，非现场ＥＣＳＴＭ比较研究表明，ＳＴＭ针尖对针尖局部区域的电沉积起屏蔽作用，针尖所在区域Ｃｕ的沉积速度比其它区域明显减小     

Highly enantioselective 1,4-conjugate addition of diethylzinc to acyclic enones with chiral phosphite–pyridine ligands derived from H8-NOBIN

A series of new phosphite–pyridine ligands, based on the H₈-binaphthyl backbone, were synthesized and employed in the copper-catalyzed enantioselective 1,4-conjugate addition of diethylzinc to acyclic enones. Ligands derived from (S)-H₈-NOBIN provided better results than their parent ligands in the reaction. Ligand L1 provided excellent ees for trans-4-aryl-3-buten-2-ones (up to 97.8% ee) as substrates. Ligand L2 was very efficient for various para-chalcones, and up to 97.2% ee was achieved.