A single-step photolithographic interface for cell-free gene expression and active biochips

We have developed a biochip platform technology suitable for controlled cell-free gene expression at the micrometer scale. A new hybrid molecule, "Daisy", was designed and synthesized to form in a single step a biocompatible lithographic interface on silicon dioxide. A protocol is described for the immobilization of linear DNA molecules thousands of base pairs long on Daisy-coated surfaces with submicrometer spatial resolution and up to high densities. On-chip protein synthesis can be obtained with a dynamic range of up to four orders of magnitude and minimal nonspecific activity. En route to on-chip artificial gene circuits, a simple two-stage gene cascade was built, in which the protein synthesized at the first location diffuses to regulate the synthesis of another protein at a second location. We demonstrate the capture of proteins from crude extract onto micrometer-scale designated traps, an important step for the formation of miniaturized self-assembled protein chips. Our biochip platform can be combined with elastomeric microfluidic devices, thereby opening possibilities for isolated and confined reaction chambers and artificial cells in which the transport of products and reagents is done by diffusion and flow. The Daisy molecule and described approach enables groups not proficient in surface chemistry to construct active biochips based on cell-free gene expression.     

薄板结构动力学特性建模解析

运用边界元法研究薄板结构的动力学特性。从薄板自由振动的微分方程式出发,由相应的静态基本解建立薄板自由振动的边界控制方程,并依据边界上的约束条件,推导出薄板结构在边界和域内的动力学方程。为了避免求域内项的积分,将上述两个方程进行联立求解,快速、准确地得到薄板结构的频率方程表达式。数值计算和实验结果表明,该文方法具有良好的解析计算精度和较高的计算效率。     

组合式挡土墙在寒区软基上的应用

通过实例详细地论述了组合式挡土墙在寒区软基上的应用。克服了冻胀、沉陷对工程的破坏,保证了工程正常运行,在北方水利工程建设中具有一定的推广价值     

Molecular lubricants for silicon‐based microelectromechanical systems (MEMS): a novel assembly strategy

Microelectromechanical systems (MEMS) are poised to bring the next technology revolution. At present, many of these are fabricated from silicon using lithographic techniques developed in the microelectronics industry. Due to the large surface area to volume ratio on the micrometer scale, surface forces, such as adhesion and friction, are often detrimental to the fabrication and operation of MEMS devices. Thus, one of the key issues in MEMS is surface engineering to reduce adhesion and friction. Here, we present a general strategy for the efficient assembly of organic layers directly onto the silicon surface in both vacuum environment and solution phases via the robust Si–N or Si–O linkage. This is achieved by the reaction between an amine or alcohol functional group and a chlorinated Si surface. The resulting surface assemblies are thermally stable. Characterization by interfacial force microscope (IFM) reveals that these assemblies have very low surface energy and are mechanically stable. This revised version was published online in September 2006 with corrections to the Cover Date.     

拼装式食品周转箱结构设计

设计了一种拼装式食品周转箱,详细介绍了周转箱的侧板、底板和连接件的结构,并分析了周转箱的成型工艺。研究表明,该拼装式周转箱清洁卫生性能优良,能够灵活地组合不同尺寸,可循环使用,节约材料、空间和成本,能体现绿色环保思想。     

Ultra-Fine Control of Silica Shell Thickness on Silver Nanoparticle-Assembled Structures

To study the distance-dependent electromagnetic field effects related to the enhancement and quenching mechanism of surface-enhanced Raman scattering (SERS) or fluorescence, it is essential to precisely control the distance from the surface of the metal nanoparticle (NP) to the target molecule by using a dielectric layer (e.g., SiO₂, TiO₂, and Al₂O₃). However, precisely controlling the thickness of this dielectric layer is challenging. Herein, we present a facile approach to control the thickness of the silica shell on silver nanoparticle-assembled silica nanocomposites, SiO₂@Ag NPs, by controlling the number of reacting SiO₂@Ag NPs and the silica precursor. Uniform silica shells with thicknesses in the range 5–40 nm were successfully fabricated. The proposed method for creating a homogeneous, precise, and fine silica coating on nanocomposites can potentially contribute to a comprehensive understanding of the distance-dependent electromagnetic field effects and optical properties of metal NPs.     

Molecular Lubricants and Glues for Micro‐ and Nanodevices

Research advances in molecular coatings from functional polymeric and organic molecules designed as molecular lubricants or molecular glues for micro‐ and nanodevices are presented here, with a focus on organized molecular films from amphiphilic molecules, molecules with reactive ends and functional oligomers. The interfacial properties of molecular coatings critical for their lubrication (see Figure) or adhesive performance at the nanoscale are discussed in conjunction with results on molecular structure and morphology of these coatings. Examples of the latest developments in the field of nanocomposite molecular coatings and applications of molecular lubrication concepts for computer hard drives are presented.     

BIM技术在装配式内装设计中的应用

阐述了装配式装修的概念、优势和BIM技术在装配式装修行业的应用现状.结合BIM软件,从族库建立、参数化建模、碰撞检查、施工图出图、工程算量等方面提出了装配式装修设计的技术路线.以全装配式装修研发实验房项目为例,详细介绍了装配式装修BIM设计过程,验证了技术思路的可行性与合理性,为推动BIM技术在装配式装修行业的应用提供...