Roughness of the globular protein surface]

The area and volume of the approximating ellipsoids taken from low resolution X-ray data have been calculated for 65 globular proteins. It has been shown that the dependence of these values on the protein molecular mass (M) coincides with those for even isometric bodies. This indicates that the asymmetry of globular proteins does not grow with the increase of their sizes. At the same time the 0.73 slope of the log-log dependence of the accessible surface area (A(s)) on the protein molecular mass differing from the value of 0.67 for even isometric bodies was observed (Miller S. et al., J. Mol. Biol. 1987. V.196. P.641). This can be explained by peculiarities of the protein surface. The method of molecule shape recovery by spherical harmonics has shown that the domain organization of protein molecule cannot explain the observed difference. Therefore the more detailed analysis of protein surface structure would be necessary.     

用ATmega8单片机设计串行编程器

介绍了美国ATMEL公司的新款单片机ATmega8的主要特点，并结合AVR单片机的编程特性的描述，论述了串行编程工作原理，并利用ATmega8采设计串行编程器。     

Structural effects of interaction between lanthanum cuprate and cerium dioxide

In the present work the structural effects of La₂CuO₄ doping with CeO₂, or of supporting the former on the latter, have been investigated. It was found that lanthanum oxide possesses a very good solubility in cerium dioxide in the presence of copper oxide, forming a solid solution. According to our experimental data, at 1050 °C and in the presence of copper oxide (over 1.5% mass), the boundary for the existence of the Ce_1-zLa_zO_2-z/2-δ phase falls between z = 0.398 and z = 0.462. Copper oxide itself has a very low, but appreciable solubility in this system. The excess of CuO strongly increases the rate of formation of the solid oxides solution, due to its relatively low melting point. This revised version was published online in November 2006 with corrections to the Cover Date.     

利用I2V 正向特性提取PN 二极管主要参数的研究

研究了利用电流－电压（I－V）正向特性提取PN结二极管参数的方法，与通常使用的PN结二极管模型不同，本文模型考虑了并联电导对电流的影响，在I－V特性曲线上读取四级（V，I）值，用牛顿法对模型方程组进行数值求解，可提取出PN结二极管的主要参数：反向饱和电流，串联电阻，发射系数以及并联电导。结果表明，该方法简便，实用。     

Experimental grounds for using chlorin e6 in the photodynamic therapy of malignant tumors

The toxicity, pharmacokinetics and antitumour effect of chlorin e6 after light irradiation were studied. The LD50 value of chlorin e6 in C3H mice is 189 +/- 9 mg kg-1 and in Wistar white rats is 113 +/- 18 mg kg-1 14 days after intraperitoneal injection. The concentration of chlorin e6 in blood, liver, kidney, spleen and tumors (sarcoma M-1 and sarcoma 45) of the rats was determined by a fluorescence method, 3, 6, 12, 18, 24, 48 and 72 h after administration at a dose of 10 mg kg-1. For this purpose, chlorin e6 was extracted from tissues by the detergent Triton X-100. The depth of necrosis in sarcoma 45, the regression rate of sarcoma M-1 and the animal cure rate were evaluated after chlorin e6 administration at doses of 1-10 mg kg-1 and subsequent irradiation with krypton laser light. Depending on the dose and the time interval between chlorin e6 injection and irradiation, the depth of necrosis in sarcoma 45 varied from 5.0 to 15.0 mm. The cure rate of the animals with sarcoma M-1 varied from 10% to 60%. The antitumor effect was directly proportional to the chlorin e6 dose and light energy exposure and inversely proportional to the time interval between photosensitizer injection and irradiation.     

电沉积ZnO薄膜超声处理后结构和缺陷的研究

以辛基酚聚氧乙烯(10)醚为有机添加剂,阴极电沉积制备了ZnO薄膜.经超声处理后,用X-射线衍射仪和光致发光光谱仪研究了ZnO薄膜的结构、应力状态和发光性能的变化.结果表明:样品的结晶性能变差,晶格内部的压应力变为张应力,于λ=395 nm处的激子发光峰和λ=580nm处的黄光发光峰强度比减小,同时发光谱中又出现了于λ...