Photosensitive sacrificial polymer with low residue

In this study, a technique is described to achieve enclosed air-cavities using a photosensitive sacrificial polymer with significantly lower residue. The residual residue after decomposition of the sacrificial polymer originates primarily from the photoacid generator used for patterning the polymer. In the two-layer technique, the photoacid is added only to the top layer resulting in significantly lower overall PAG loading. During decomposition, the photoacid used to decompose the polymer in the top layer then diffuses into the acid-free region promoting decomposition in the otherwise non-photosensitive layer. This approach significantly lowered the amount of residue produced. These results also showed that the acid generated from the PAG after UV radiation was not consumed by the polymer in the layer from which it originated. Rather, the acid was reused in other layers. The patterns fabricated from the two-layer structure used less PAG, had higher spatial resolution, and less line edge roughness. When the thickness of the top PAG-loaded layer was decreased, a lower UV exposure dose was required to achieve patterning.     

A review of recent progress in holmium-doped silica fibre sources

In this paper we present a review of holmium-doped silica fibre based sources. We discuss recent demonstrations of an efficient cladding-pumped fibre geometry and the impact it has made on the power scaling of these sources. We discuss the wavelength region that is addressable by holmium-doped silica based devices and highlight the advantage over thulium-doped fibres in terms of atmospheric transmission. Finally we review the development and current status of the pulsed and CW operation of holmium fibre sources and discuss the future development potential of sources in the ns-fs pulse-width range.     

分散红3B在聚酯超细纤维上吸附等温线的绘制

对分散红３Ｂ上染普通聚酯纤维、减量前后聚酯超细纤维的等温吸附线进行了不测定,证实了在聚酯超细纤维的低温染色过程中存在Ｎｅｒｎｓｔ和Ｌａｎｇｍｕｉｒ二元吸附的可能性,并对其它位吸附的机理进进了分析。     

CATV fibre-optic supertrunking: A comparison of parameters and topologies using analog and/or digital techniques

Fibre-optic supertrunking has a well-established place in larger CATV networks. Supertrunks have to be transparent to the quality of the transmitted TV signals and they have to have a negligible impact on the system reliability of the total network. At least 60 dB (weighted) video SNR has to be achieved and down times of less than one hour per year per fibre are desirable. AM on fibre can achieve these goals only in shorter supertrunks. FM and digital modulation techniques with a higher loss budget than AM are well suited for high transmission quality as well as for redundant supertrunk topologies, achieving excellent system availability numbers at the expense of increased equipment complexity.     

人造牛肉的研究

将植物制成蛋白纤维,生产色、香、味、质地及口感均酷似天然肉品的研究在国外已取得重大进展,产品已广泛应用于学校、医院、监狱等的食堂中。我国在这方面的研究则刚兴起,本文根据天然牛肉纤维较粗的这一特点,应用“粗纺法”直接将大豆分离蛋白纺成1mm左右的纤维,以此为原料生产人造牛肉,并对该法存在的问题及解决途径作了探讨。     

聚丙烯装置聚合区设备布置及管廊的配管设计

结合工程特点及工艺流程,阐述了300 kt/a聚丙烯装置的布置原则,管道、管架设计要点和方法,以及需要注意的问题。     

内层半固化片选择对PCB耐CAF性能的影响

阳极导电丝（CAF）是PCB业内近十年来较为热门的可靠性问题之一,当PCBA工作在高温高湿的环境下时,有可能产生沿玻璃纤维生长的阳极导电丝CAF。文章主要研究了PCB设计中的关键因素叠层设计对耐CAF性能的影响,通过分析不同半固化片的异同点,对比不同半固化片在玻纤裂纹和CAF失效寿命方面的差异。通过不同半固化片的CAF寿命数据,推算不同叠层设计的CAF寿命,为有较高cAF可靠性要求的产品研究提供了理论依据和试验基础。     

Initial deployment of fibre in the local network for narrowband use in Spain: Technology,engineering and cost

This paper covers: (1) the field trials, with fibre in the local network systems, being conducted in Spain and intended for delivery telephone-based services to residential customers; (2) the technical and functional requirements of these types of system intended for commercial (regular) deployment to be started around late 1993/early 1994, and (3) the most relevant initial deployment scenarios and persubscriber investment aspects. The field trials are located in Madrid and in Barcelona: their rationale, technical characteristics and the lessons learned so far are described. Such trials are providing insight into what requirements and objectives are anticipated to be needed should such new technology be an actual alternative to copper-based subscriber loops. The requirement for such fibre in the local network systems intended for regular deployment in the near term are indicated, including technical and functional requirements of the optical line terminals (OLTs) (at local exchanges) and optical network units (ONUs) (located near customer premises); transmission requirements and optical distribution network (ODN) requirements and design aspects. For starting regular deployment, three preferred scenarios are identified. The chief parameters affecting persubscriber investments are illustrated including the number of fibres per ONU, and the number of users being served from each ONU. It is shown that in order to achieve cost parity with copper loop (which requires an initial investment of between $600 and $800) a capacity of some 60 narrowband (64 kb/s) channels per ONU should be required.     

高速CCD图像采集存储系统的硬件设计

针对某高速CCD相机图像数据量大的特点,设计采用LVDS格式信号输出,转换成Camlink格式后实现海量数据的高速、稳定传输,提出了一种新型的高速数据采集存储系统的设计方案,该方案采用Fibre Channel接口硬盘实现对图像数据的高速存储,最高存储速度可达850 Mbyte/s,现已在CCD相机系统图像采集实验中得到应用.     

双功能受阻胺与紫外线吸收剂并用的协同效应研究

本文用IR、UV、ESR、TLC等方法研究了新型的双功能受阻胺光稳定剂,Tinuvin-144 [2-(4′-羟基-3′,5′-二叔丁基)苄基-2-正丁基丙二酸五甲基哌啶醇酯]与紫外线吸收剂,UV-531(2-羟基-4-正辛氧基二苯甲酮)和UV-327(2-[2′-羟基-3′,5′-二叔丁基]-5-氯 代苯并三唑)并用体系对聚丙烯光稳定化的并用效应。结果表明,Tinuvin-144与UV-531,UV-327并用时均具有良好的协同效应,144对531,327或531,327对144的光分解均具有相互的保护作用。结果还表明,144与531或327无论在模拟体系或聚丙烯中,在诱导期内均不存在促使他们消耗的化学反应,提出了协同作用的机理。