酵母蛋白质网络的动力学性质

蛋白质-蛋白质、蛋白质-DNA相互作用网络决定了细胞中各种关键功能的执行．基于芽殖酵母(budding yeast saccharomyces cerevisiae)的蛋白质-蛋白质相互作用网络数据和相关的实验文献，我们建立了调控细胞周期和生命周期(cell cycle and life cycle)的蛋白质网络，并利用离散模型研究了该网络的动力学性质，研究表明：细胞周期网络的动力学性质具有很强的稳定性，约94％的蛋白质初态将演化到对应于生物学G1基态的稳定态，使其成为惟一的全局吸引点；同时，绝大多数的初态的演化路径都通过由G1激发态到G1基态的细胞周期演化路径，使细胞周期路径成为全局性的“吸引”路径。     

Investigation of the Li1+xV3O8 electrode–organic electrolyte interface by scanning photoelectron microscopy

To investigate the formation of a solid electrolyte interface (SEI) on the Li_1+xV₃O₈ electrode surface in the thermodynamic stability range of the organic electrolyte, we applied scanning photoelectron microscopy (SPEM) to a pristine electrode and to an electrode after ten cycles. The F K-edge absorption spectrum of the cycled electrode showed that LiF forms on the electrode surface during the lithium insertion–extraction process in the Li_1+xV₃O₈/Li cell. The photoelectron spectrum for the cycled electrode showed intense spectral features corresponding to Li 1s, F 2s, F 2p, and P 2p electron signals, whereas these spectral features were of negligible intensity for the pristine electrode. The above results give strong support for the formation of an SEI that consists of LiF and compounds containing phosphorus during operation of the battery. The SPEM images also revealed that the fluorine distribution on the surface of the cycled electrode was inhomogeneous.     

Duffing-van der Pol振子随机分岔的全局分析

应用广义胞映射方法研究了参激和外激共同作用的Duffing-van der Pol振子的随机分岔.以 系统参数通过某一临界值时，如果系统的随机吸引子或随机鞍的形态发生突然变化，则认为 系统发生随机分岔为定义，分析了参激强度和外激强度的变化对于随机分岔的影响.揭示了 随机分岔的发生主要是由于系统的随机吸引子与系统的随机鞍碰撞产生的.分析表明，广义 胞映射方法是分析随机分岔的有力工具，这种全局分析方法可以清晰地给出随机分岔的发生 和发展. 关键词： 随机分岔 全局分析 广义胞映射方法 随机吸引子 随机鞍     

干电池供电式电子标准电池的设计

标准电池是度量电源电动势的标准仪器．利用RC4191和MC1403精密的低压稳压特性，设计一款电子稳压式的标准电池，既可克服传统汞镉标准电池的缺点，又能保证相同精度的实验性能要求．     

SXDG-1型汽车前照灯全自动检测仪的微机控制

SXDG—1型汽车前照灯全自动检测仪是用于检测汽车前照大灯光轴的偏斜情况及发光强度并进行定量检验的专用设备。它可以自动测出有关参数,并予以数字显示和打印输出。本文介绍了该仪器的主要性能、工作原理及微机控制系统(包括硬件结构和软件设计思想等)。     

Hydrothermal synthesis of FeS2 for lithium batteries

Nanocrystalline FeS₂ cathode material of lithium cell was synthesized from cheap materials of FeSO₄, Na₂S₂O₃, and sulfur by a hydrothermal process. The scanning electron microscopy analysis showed the obtained material was nano-sized, about 500 nm. The X-ray powder diffraction analysis showed that the synthetic FeS₂ material had two phases of the crystalline structure, pyrite and marcasite. The phase of marcasite seems to have no negative effect on the electrochemical performance of the material. The synthetic FeS₂ showed a significant improvement of electrochemical performance for Li/FeS₂ cells.     

C波段平面异向介质设计及其后向波特性验证

提出了一种工作在C波段的新型平面结构异向介质，它除了带宽宽和损耗小外，还具有体积小、结构简单的优点，而且能够实现工作频段的平移，频率平移范围为4—20 GHz.基于电磁波由自由空间入射半无限大异向介质平板的传输和反射数据，计算出了电波在其中传播时的相速随频率的变化曲线，结果表明所讨论的异向介质确实在预想的频段上表现出后向波特性；同时利用相位观察法进一步验证了上述的后向波特性，从而肯定了异向介质的存在. 关键词： 异向介质 宽频带 小单元 后向波特性     

Spectral Representation Theory for Dielectric Behavior of Nonspherical Cell Suspensions

Recent experiments revealed that the dielectric dispersion spectrum of fission yeast cells in a suspension was mainly composed of two sub-dispersions. The low-frequency sub-dispersion depended on the cell length, while the high-frequency one was independent of it. The cell shape effect was simulated by an ellipsoidal cell model but the comparison between theory and experiment was far from being satisfactory. Prompted by the discrepancy, we proposed the use of spectral representation to analyze more realistic cell models. We adopted a shell-spheroidal model to analyze the effects of the cell membrane. It is found that the dielectric property of the cell membrane has only a minor effect on the dispersion magnitude ratio and the characteristic frequency ratio. We further included the effect of rotation of dipole induced by an external electric field, and solved the dipole-rotation spheroidal model in the spectral representation.Good agreement between theory and experiment has been obtained.     

脑细胞激活素药物的化学成分分析

采用日本岛津LC-60A型高压液相色谱仪和美国P-E3030型原子吸收分光光度计，对该药进行了氨基酸、维生素和化学元素的含量测定。结果表明，该药含有18种氨基酸，不少于3种维生素和20几种化学元素，为进一步改进该药物的合理配制方法和临床应用提供了参考数据。     

Modeling of environmentally significant interfaces: Two case studies

When some parameters cannot be easily measured experimentally, mathematical models can often be used to deconvolute or interpret data collected on complex systems, such as those characteristic of many environmental problems. These models can help quantify the contributions of various physical or chemical phenomena that contribute to the overall behavior, thereby enabling the scientist to control and manipulate these phenomena, and thus to optimize the performance of the material or device. In the first case study presented here, a model is used to test the hypothesis that oxygen interactions with hydrogen on the catalyst particles of solid oxide fuel cell anodes can sometimes occur a finite distance away from the triple phase boundary (TPB), so that such reactions are not restricted to the TPB as normally assumed. The model may help explain a discrepancy between the observed structure of SOFCs and their performance. The second case study develops a simple physical model that allows engineers to design and control the sizes and shapes of mesopores in silica thin films. Such pore design can be useful for enhancing the selectivity and reactivity of environmental sensors and catalysts. This paper demonstrates the mutually beneficial interactions between experiment and modeling in the solution of a wide range of problems.