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排序方式: 共有939条查询结果,搜索用时 31 毫秒
1.
一种PDMS薄膜型微阀的制备与性能分析   总被引:2,自引:0,他引:2  
通过厚胶光刻工艺在硅片上制备SU-8胶模板,利用该模板制备了高分子聚合物PDMS(Polvdimethvlsiloxane,聚二甲基硅氧烷)微流道和薄膜结构。通过对不同结构的两层PDMS的不可逆粘接得到一种简单的阀结构,在外加气源压力作用下薄膜产生变形实现对微流道的控制。实验测量了微阀的控制气源压力与被控制液体流量之间的关系,说明膜阀的开闭性能良好。根据弹性薄膜的变形理论,对影响微阀性能的参数进行了分析,并提出了几种可行的用于薄膜微阀控制的方法。  相似文献   
2.
软印刷技术     
软印刷技术是基于弹性体印章/模具来转移图形结构的微纳加工技术。详细介绍了软印刷技术中转移图形结构的多种方式,并探讨软印刷技术在微纳电子学、光学、传感器、生物等领域的广泛应用。对软印刷技术的弹性体印章/模具制备、聚二甲基硅氧烷的属性、理论研究等进行了探讨。  相似文献   
3.
介绍了时间戳规范的编制背景和时间戳系统部件组成.时间戳的产生和颁发、时间戳的管理、时间戳的格式和时间戳系统的安全等方面的具体内容。  相似文献   
4.
We describe a novel microfluidic perfusion system for high-resolution microscopes. Its modular design allows pre-coating of the coverslip surface with reagents, biomolecules, or cells. A poly(dimethylsiloxane) (PDMS) layer is cast in a special molding station, using masters made by photolithography and dry etching of silicon or by photoresist patterning on glass or silicon. This channel system can be reused while the coverslip is exchanged between experiments. As normal fluidic connectors are used, the link to external, computer-programmable syringe pumps is standardized and various fluidic channel networks can be used in the same setup. The system can house hydrogel microvalves and microelectrodes close to the imaging area to control the influx of reaction partners. We present a range of applications, including single-molecule analysis by fluorescence correlation spectroscopy (FCS), manipulation of single molecules for nanostructuring by hydrodynamic flow fields or the action of motor proteins, generation of concentration gradients, trapping and stretching of live cells using optical fibers precisely mounted in the PDMS layer, and the integration of microelectrodes for actuation and sensing.  相似文献   
5.
A new composite catalyst for selective epoxidation of olefins with tert-butyl hydroperoxide (tBHP) is reported. The catalyst contains manganese diimine complexes (cis-Mn bis-2,2′-Bipyridyl), occluded within a NaY zeolite, in turn incorporated in a polydimethylsiloxane membrane (cis-[Mn(bpy)2]2+-NaY-PDMS). The three-step synthesis consists of a Mn2+exchange of NaY, ligand sorption to form cis-[Mn(bpy)2]2+-NaY and incorporation of the latter in a PDMS membrane. The major differences between [Mn(bpy)2]2+-NaY as such and occluded in PDMS are observed in the sorption and catalytic characteristics. With the membrane system, the use of a solvent becomes obsolete. Whereas optimal cyclohexene oxidation with [Mn(bpy)2]2+-NaY occurs with hydrogen peroxide in acetone, tBuOOH proves to be a better oxidant for [Mn(bpy)2]2+-NaY-PDMS. The reactions in batch and fed-batch reactors are discussed. A simple regeneration procedure, monitored by FT-IR spectroscopy is proposed.  相似文献   
6.
《The Journal of Adhesion》2008,84(3):231-239
A process to fabricate stretchable gold tracks on silicone rubber substrates is studied by XPS, static water contact angle measurement, AFM, and SEM. The process involves several steps: removing uncured oligomers by hexane Soxhlet extraction; pre-stretching the substrate; activating the strained silicone surface by an oxygen plasma treatment; coating the strained substrate with 5 nm titanium and 80 nm gold layers; and finally releasing the sample. The plasma treatment creates a thin brittle silica-like layer that temporarily increases the substrate's surface energy. Indeed, the plasma treatment is followed by a hydrophobic recovery. As a consequence, the delay between plasma treatment and metal deposition has to be reduced as much as possible. The silica-like layer can be nicely observed after release. The entire process allows us to obtain stretchable metallized samples that remain conductive even after an excessive deformation leading to electrical failure.  相似文献   
7.
武钢第二炼钢厂连铸坯喷号机自动控制系统   总被引:1,自引:0,他引:1  
邹红 《武钢技术》2004,42(5):38-40
对武钢第二炼钢厂连铸坯喷号机自动化控制景统配置、网络通讯、伺服控制系统进行了阐述;经运行考验证明系统性能提高、稳定可靠。  相似文献   
8.
由于多媒体信息系统中,需要集成各种数据类型,而这些数据类型又有着密切的时间关系,所以对于多媒体来说,同步问题是很重要的,而同步的基础是为同步关系建立一个独立于实现环境的抽象的表示模型,本文着重讨论几种描述媒体同步关系的模型。  相似文献   
9.
Force-balance experiments in conjunction with the Johnson-Kendall-Roberts (JKR) theory have been used to determine the work of adhesion between solid systems. It has been shown that deficiencies in understanding the deformation behavior can lead to erroneous results. A modified procedure for determining the work of adhesion by force-balance experiments and JKR theory using normal displacement behavior has been introduced to address these deficiencies. This procedure involves improved experiental and data analysis protocols and has been applied to give more precise work of adhesion values for PDMS poly(dimethylsiloxane)-PDMS, PDMS-F(fluorinated silicon) and PDMS-Si (silicon) systems. The work of adhesion determinations are consistently less than those estimated by contact angle measurements.  相似文献   
10.
Recent advances in the various theories of strain-birefringenece of polymer networks are presented. The classical theories as well as the more advanced models are outlined together with some recent theoretical results on poly (dimethylsiloxane). Reference to work on other Si-containing polymers is made. The problems of intermolecular correlations occurring in polymer networks and their effect on the observed optical properties are discussed with reference to the optical-configuration parameter. Conclusions report areas of current research.This review was presented at the Second International Topical Workshop, Advances in Silicon-Based Polymer Science.  相似文献   
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