Single-mode rib polymer waveguides and electro-optic polymer waveguide switches

Mode-matching and effective index methods are used to analyze single-mode operation of optical rib polymer waveguides. Their single-mode waveguiding conditions are determined. Single-mode rib waveguides fabricated from guest–host polyetherketone are presented. The estimated propagation loss of straight rib-waveguides is 0.7 dB/cm at 1.55 μm. Furthermore, by using the mode field-transfer matrix method, 2×2 and 4×4 polymer Mach–Zehnder interference switch operating at 1.55 μm wavelength has been designed based on optical multi-mode interference.     

夫琅禾费衍射公式的一般形式

从不同的途径导出了大角度情形下亦成立的夫琅禾费衍射积分的一般形式，指出此一般形式公式是求解夫琅禾费衍射的基本公式．并通过对夫琅禾费衍射公式的级数形式的推导，揭示了傅里叶光学中“夫琅禾费衍射公式”与一般形式公式存在的差别，以及消除这种差别的措施．此外，还较详细地讨论了倾斜因子对衍射花样的影响．这对于衍射测量及深入理解夫琅禾费衍射的本质有一定的指导意义．     

超短脉冲贝塞尔光束的非近轴效应对传输的影响

 对超短脉冲贝塞尔光束在近轴近似和非近轴情况下自由空间中的传输作了研究。结果表明，其空间波形在传输中保持贝塞尔形状不变，不受非近轴效应影响；然而当空间参数较大时，非近轴效应影响超短脉冲贝塞尔光束的时间波形。     

Modeling hyperelastic behavior of rubber: A novel invariant‐based and a review of constitutive models

A constitutive phenomenological model completing the Gent‐Thomas concept is carried out to formulate laws governing the hyperelastic behavior of incompressible rubber materials. It is shown that the phenomenological Gent‐Thomas model (1958) and the constrained chain model (1992) give similar precise results at small to moderate deformation. On the other hand, comparisons of the outcome of the proposed model with that of the molecular model from the combined concepts of Flory‐Erman and Boyce‐Arruda (2000), and with those of the phenomenological models of Ogden (1982), Yeoh‐Fleming (1997), Pucci‐Saccomandi (2002) and Beda (2005) are made. Residual inconveniences raised by attractive continuum models in rubber elasticity literature have been successfully overcome. Results from both the statistical and phenomenological mechanics concepts are compared with the data of some useful classical materials (rubbers of Treloar, Rivlin‐Saunders, Pak‐Flory and Yeoh‐Fleming). The results permit one to see salient equivalence of the two theories for a more reliable prediction of stress‐stretch response for all states of any mode of deformation. A complete and exhaustive analysis of the Mooney plot that combines small and very large extension‐compression has been quite essential in assessing the validity of models. A method of identification of material parameters is presented and data of the simple tension suffice for the determination of the parameter values. It is shown that the ordinary identification procedures, such as the usual least squares, a very much used numerical method in materials investigation, can be unsuitable in some cases of hyperelastic modeling. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1713–1732, 2007     

Circadian synchrony in networks of protein rhythm driven neurons

The interaction between gene activation and cellular activity has recently emerged as a critical aspect of brain behavior, but the dynamics of networks incorporating these interactions are poorly understood. An interesting phenomena arises when the genetic activation oscillates endogenously and a network of such cells synchronize to a coherent rhythm, such as is the case with the suprachiasmatic nucleus. To explain this synchronization, we propose a model in which a mRNA/protein expression cycle drives neurons electrical activity, and synaptic activation shifts the phase of the protein rhythm. Using lattice networks, we demonstrate that these interactions are sufficient to generate coherent oscillation. © 2006 Wiley Periodicals, Inc. Complexity 12: 67–72, 2006     

神经网络在工程爆破应力波规律探讨中的应用

采用BP（Back Propagation)前馈人工神经网络模型，对工程爆破中柱状震源的自由场应力波传播规律进行了探讨。结果表明：利用人神经网络模型的非线性映射功能，可以较好地给出工程爆破引起的近区自由场力学规律，对于同类型问题的研究，也有着很重要的意义。     

Taura 综合征病毒主要结构蛋白的表达与纯化

根据Taura综合征病毒(TSV)基因组,设计特异性引物,从感染病毒组织中提取组织总RNA后扩增,分别将3个主要结构蛋白基因VP1、VP2和VP3克隆到pGEM TEasyVector.与表达载体连接后,导入大肠杆菌中诱导表达,并纯化目的蛋白.诱导表达的融合蛋白分子量分别为54.2×103、43×103和57.1×103,在变性条件下过柱纯化VP1和VP2,一次可以纯化10mg以上纯度较高的蛋白.     

Time-domain simulations of sound propagation through screen-induced turbulence

A flow model in combination with a statistical-dynamical turbulence generator and a linearised Euler time-domain model for sound waves were used to simulate the effect of screen-induced turbulence on the noise level in the acoustical shadow of a screen in wind. Instead of simulating a great number of different frozen turbulence realisations, the concept of transient turbulence was successfully tested and applied. This concept is adequate to the time-domain model and reduces the computational demands. Several two-dimensional simulations allowed to isolate the individual effects of wind and screen on the propagation of 500 Hz sound waves over a 4-m high noise barrier. At a distance of 250 m from the source (240 m behind the screen) the sheltering effect of the screen and the refraction effect of the wind are in the order of 6 and 4 dB, respectively. The screen-induced turbulence leads to fluctuations in the noise level with a standard deviation of 1.2 dB and a maximum amplitude of 3 dB. However, the time averaged effect turned out to be in the order of merely 0.2 dB. The effect of the screen-induced turbulence on the average noise level behind the screen is therefore negligible.     

TNFa在血管内皮细胞ECV304中的靶向表达研究

在缺失了3'LTR U3区内病毒的启动子／增强子序列的逆转录病毒载体pLXSNd中,用血管内皮生长因子受体KDR的特异性启动子调控了TNFa在血管内细胞ECV304中的靶向表达。将构建的载体pLXSN-TNFa,pLXSNd-KDRp-TNFa和空载体pLXSN用PA317细胞包装后获得重组病毒,并用重组病毒分别感染NIH3T3细胞和ECV304细胞,培养物上清的ELISA结果证明,KDR启动子指导的TNFa在KDR阳性细胞ECV304中的表达量为在KDR阴性细胞NIH3T3中的表达量的8倍;而TR指导的TNFa在这两种细胞中的表达无明显差异,实现了TNFa在血管内皮细胞中的靶向表达,这可能为肿瘤基因治疗提供新途径。     

TRANSFER OF FOREIGN GENES BY ELECTROPORATION AND THEIR EXPRESSION IN MAMMALIAN CELLS

Expression of foreign genes transferred into mammalian cells by electroporation has been studied. The pX1TK gene, pSV2Neo gene and pUCEJ oncogene have been introduced into MLTK-cells and NIH/3T3 cells, respectively. Stable transformation transient expression of TK gene by MLTK-cells as well as stable and malignant transformation of NIH/3T3 cells have been obtained. Transient expression frequency is about 80% and stable transformation frequency is about 10~(-4). Integration of foreign genes into the cellular genome was verified with molecular hybridization. Tumor development was observed after inoculation of transformed celts into nude mice.