Flow-injection spectrophotometric determination of sulfadiazine and sulfamethoxazole in pharmaceuticals and urine.

A rapid and sensitive flow-injection spectrophotometric method is proposed for the determination of sulfadiazine and sulfamethoxazole. This method is based on the diazotization of sulfonamide with sodium nitrite, and a coupling reaction of the diazo-compound with alpha-naphthylamine. The optimum experimental conditions are obtained by using the controlled and weighted centroid simplex method. The linear ranges for the determination of sulfadiazine and sulfamethoxazole are 0.2-20 microg ml(-1) and 0.1-20 microg ml(-1), and their detection limits are 0.06 microg ml(-1) and 0.05 microg ml(-1), respectively, and the sampling frequency is 130 samples per hour. The method has been used to determine sulfadiazine and sulfamethoxazole in pharmaceuticals and urine without separation. The results are in agreement with those obtained by a high-performance liquid chromatograph technique at the 95% confidence level.     

金属UV光敏薄膜的实验研究

介绍了金属Au和Al薄膜的制备方法，研究了其UV光电发射特性，并做了寿命实验。给出了在真空中以及放在大气中光电发射衰减的情况。指出了其在大气中达到一个稳定值之后，再反复多次暴露于干燥大气时仍存在一个稳定光电发射周期的特点，可长达数月。金属薄膜有一个最佳膜层厚度，这与光电发射逸出深度、膜层结构等密切相关。近年来光电子成像器件发展非常迅速，急需光电发射均匀的面电子源，因此在微通道板的特性测试和像管的动态模拟中，Au和Al金属薄膜成为被优选的对象。     

Electrical properties of high Curie temperature (1−x)Pb(In1/2Nb1/2)O3-xPbTiO3 single crystals grown by the solution Bridgman technique

0.65Pb(In_1/2Nb_1/2)O₃-0.35PbTiO₃ (PINT65/35) (starting composition) single crystals were grown successfully through the solution Bridgman technique using PbO flux and PMNT67/33 seed crystals. Because of the composition variation, the final composition of achievable crystals is in a range of 0.32-0.34 with the corresponding T_c range of 265-269 °C. The (001) plates of as-grown PINT66/34 single crystals show high Curie temperature (T_c=269 °C) and rhombohedral-tetragonal phase transition temperature (T_rt=134 °C). Besides, good electrical properties with high dielectric constant (ε>3000), low dielectric loss (tan δ∼1.2%), high piezoelectric constant (d₃₃∼2000 pC/N) and large electromechanical coupling factor (k_t≈59%) at room temperature have been obtained on the (001) plates. The sound velocity, acoustic impedance and other piezoelectric parameters were also measured on the (001) plates in this study, which provide us more detailed information about PINT66/34 single crystals.     

新型菲涅尔线聚焦聚光太阳电池组件研究

以聚甲基丙烯酸甲脂为材料,采用热压成型工艺加工成型线聚焦菲涅尔聚光透镜(8×),可用于空间、地面光伏系统太阳电池组件的聚光系统,并对在其聚光条件下,太阳电池的电流电压特性进行测试,结果表明,该菲涅尔线聚焦棱镜能有效提高太阳电池的单位输出功率.模具的机械加工精度和光学抛光精度低,是造成其部分聚光率损失的原因.     

Optimal control of the obstacle in a quasilinear elliptic variational inequality

In this paper we consider an obstacle control problem where the state satisfies a quasilinear elliptic variational inequality and the control function is the obstacle. The state is chosen to be close to the desire profile while the H² norms of the obstacle is not too large. Existence and necessary conditions for the optimal control are established.     

The primary investigation of optical-limiting effects of optical active phthalocyanine derivative TMBO-SiPc

The optical-limiting property of an optically active phthalocyanine derivative with different configuration in chloroform solution was measured at 532 nm with 10 ns pulses. The excited state absorption cross-section σ_ex of the derivative was determined with the Z-scan technique. The results showed that the phthalocyanine derivative possesses larger σ_ex than the ground state absorption cross-section σ₀, indicating that it is a material for reverse saturable absorption. And it is specially noticed that the change in the optically active configuration affects its optical-limiting property significantly.     

Probabilistic and Average Linear Widths of Sobolev Space with Gaussian Measure in L \infty-Norm

In this paper we investigate the probabilistic linear $(n,\delta)$-widths and $p$-average linear $n$-widths of the Sobolev space $W^r_2$ equipped with the Gaussian measure $\mu$ in the $L_{\infty}$-norm, and determine the asymptotic equalities \begin{eqnarray*} \lambda_{n,\delta}(W^r_2,\mu,L_{\infty}) &\asymp&\frac{\sqrt{\ln (n/\delta)}}{n^{r+(s-1)/2}},\\[3pt] \lambda^{(a)}_n(W^r_2,\mu,L_{\infty})_p &\asymp&\frac{\sqrt{\ln n}}{n^{r+(s-1)/2}}, \qquad 0 < p < \infty. \end{eqnarray*}     

现代教育技术在物理教学中的应用

现代教育技术与课程教学的整合,是我国面向21世纪基础教育教学改革的新视点。笔者就物理教学中应用现代教育技术的实践作初步探讨。     

信息技术与物理课程整合的几个层面

《基础教育课程改革纲要》要求 :要“大力推进信息技术在教学过程中的普遍应用 ,促进信息技术与学科课程的整合 ,逐步实现教学内容的呈现方式、学生的学习方式、教师的教学方式和师生互动方式的变革 ,充分发挥信息的优势 ,为学生的学习和发展提供丰富多彩的教育环境和有力的学习工具 .”可见 :信息技术与其它课程的整合是课程教学中把信息技术、信息资源、信息方法和课程内容有机结合 ,是一种新型的教学方式 .下面讨论几个具体层面上的问题 :1　信息技术与物理教学目标和内容的整合面对新世纪 ,信息处理的技能、学习能力、问题解决能力、与…     

Pt（IV）修饰的非晶态TiO2对2，4-二氯苯氧基乙酸的可见光降解

用溶胶-凝胶法制备了在可见光照射下具有光催化活性的掺杂P（t Ⅳ）离子的非晶态微孔TiO2，表面积为160～200 m2/g；含3.0%Pt（Ⅳ）的AMM-Ti具有最大的光催化活性. X射线精细结构分析（EXAFS）表明，单个的PtCl4分子均匀地分布在非晶态二氧化钛表面；用这种光催化剂降解2，4-二氯苯氧基乙酸时，2，4-二氯苯酚是主要的中间物，通过Langmuir-Hinshelwood 方程的线性形式估算了反应速率常数k 和吸附平衡常数K，研究了光催化起始反应速率和反应物起始浓度之间的关系，同时，提