基于海明编码的EEPROM数据存取功能的实现

针对工业现场对大容量数据存储空间及数据高可靠性的要求,基于单片机的IIC接口,设计了硬件电路和软件读写程序,实现了利用8片24LC512扩展单片机外部EEPROM存储空间的目的.并结合海明码的纠错能力,对数据先编码存储、后解码读取以提高数据的可靠性.现场应用验证,此设计可以实现4 Mbit空间数据的存取,数据准确可靠.     

Optimization of Oligosaccharide Synthesis from Cellobiose by Dextransucrase

There is a growing market for oligosaccharides as sweeteners, prebiotics, anticariogenic compounds, and immunostimulating agents in both food and pharmaceutical industries. Interest in novel carbohydrate-based products has grown because of their reduced toxicity and low immune response. Cellobiose is potentially valuable as a nondigestible sugar. The reaction of cellobiose, as an acceptor with a sucrose as a donor, catalyzed by a dextransucrase from Leuconostoc mesenteroides B-512FMCM, produced a series of cellobio-oligosaccharides. This production system was optimized using a Box–Behnken experimental design for 289 mM of sucrose and 250 mM of cellobiose and 54 U of the enzyme at pH 5.2 and 30 °C, to produce maximum yields of oligosaccharide.     

柔性LED驱动器的DMX512协议转换芯片设计

传统的显示用LED驱动器通常采用速度较高的数据传输协议,而柔性LED显示系统的数据线通常要长距离传输。为了解决这个矛盾,可以使用DMX512协议进行长距离传输,并在柔性LED灯带的端口处增加一个协议转换芯片。利用FPGA芯片实现了一个应用于柔性LED驱动器的DMX512协议转换芯片,并完成了实际系统的测试工作,协议转换速度符合协议的最高速度,有很强的实际应用价值。     

High-performance IR detectors at SCD present and future

For over 27 years, SCD has been manufacturing and developing a wide range of high performance infrared detectors, designed to operate in either the mid-wave (MWIR) or the long-wave (LWIR) atmospheric windows. These detectors have been integrated successfully into many different types of system including missile seekers, time delay integration scanning systems, hand-held cameras, missile warning systems and many others. SCD’s technology for the MWIR wavelength range is based on its well established 2D arrays of InSb photodiodes. The arrays are flip-chip bonded to SCD’s analogue or digital signal processors, all of which have been designed in-house. The 2D focal plane array (FPA) detectors have a format of 320×256 elements for a 30-μm pitch and 480×384 or 640×512 elements for a 20-μm pitch. Typical operating temperatures are around 77–85 K. Five years ago SCD began to develop a new generation of MWIR detectors based on the epitaxial growth of antimonide based compound semiconductors (ABCS). This ABCS technology allows band-gap engineering of the detection material which enables higher operating temperatures and multi-spectral detection. This year SCD presented its first prototype FPA from this program, an InAlSb based detector operating at a temperature of 100 K. By the end of this year SCD will introduce the first prototype MWIR detector with a 640×512 element format and a pitch of 15 μm. For the LWIR wavelength range SCD manufactures both linear Hg_1−xCd_xTe (MCT) detectors with a line of 250 elements and time delay and integration (TDI) detectors with formats of 288×4 and 480×6. Recently, SCD has demonstrated its first prototype uncooled detector which is based on VO_x technology and which has a format of 384×288 elements, a pitch of 25 μm, and a typical NETD of 50 mK at F/1. In this paper, we describe the present technologies and products of SCD and the future evolution of our detectors for the MWIR and LWIR detection. The paper presented there appears in Infrared Photoelectronics, edited by Antoni Rogalski, Eustace L. Dereniak, Fiodor F. Sizov, Proc. SPIE Vol. 5957, 59570S (2005).     

基于嵌入式技术的表面肌电信号采集仪设计

研制一种基于嵌入式技术的便携式表面肌电信号采集仪,以ARM7微处理器AT91SAM7SE512为核心,包含肌电采集放大、A／D转换、带触摸屏的液晶显示、USB有线传输、Xbee无线传输、数据存储等多个组成部分。采用μC／OS—Ⅱ操作系统和基于μC／GUI的图形化界面,性能稳定,操作简便。为了方便用户资料及肌电数据的管理,移植了FATFS文件系统。低功耗和微型化设计提高了设备的便携性,有利于提高表面肌电信号采集仪在运动员训练中的使用率。     

基于ARM的DIS采集系统设计

介绍嵌入式系统的DIS应用,分析DIS的一般模型,设计并实现了其主体部分的软硬件。硬件以ARM7核微控制器AT91SAM7SE512为核心,包括A／D转换、带触摸屏的液晶显示、ZigBee无线连接、数据存储等多个组成部分;软件采用μC／OS-Ⅱ实时操作系统,移植了FAT文件系统和图形用户界面。经测试,系统性能稳定,操作简便。     

ADSP-21262基于AT25HP512的SPI加载

利用FLASH存储芯片通过SPI接口加载DSP可以有效地降低系统开发成本,但DSP厂商提供的FLASH烧写程序所面向的芯片并不是很多,用户需要针对特殊加载芯片自行开发烧写程序。深入分析了AT25HP512的控制命令和时序结构,提出了修正引导文件的方法,解决了ADSP 21262正确将引导核文件写入AT25HP512的问题,实现了AT25HP512对ADSP 21262的SPI加载,对开发ADSP 21262系统有一定参考意义。     

Art-net网络协议在灯光系统工程的运用

现代电视台演播厅的整体灯光布线系统已经进入新的时代,传统的DMX512工程布线方式虽然在信号传送方面仍然占据主导地位,但有一种新的以以太网协议为基础的布线方式已经悄悄地在主线传输方式上被运用,这种以太网协议就是Art-net网络协议。     

Bessel capacities on compact manifolds and their relation to Poisson capacities

A motivation for this paper comes from the role of Choquet capacities in the study of semilinear elliptic partial differential equations. In particular, the recent progress in the classification of all positive solutions of Lu=uα in a bounded smooth domain E⊂Rd was achieved by using, as a tool, capacities on a smooth manifold ∂E. Either the Poisson capacities (associated with the Poisson kernel in E) or the Bessel capacities (related to the Bessel kernel) have been used. In this and many other applications there is no advantage in choosing any special member in a class of equivalent capacities. (Two capacities are called equivalent if their ratio is bounded away from 0 and ∞.) In the literature Bessel capacities are considered mostly in the space Rd. We introduce two versions of Bessel capacities on a compact N-dimensional manifold. A class Cap?,p of equivalent capacities is defined, for ?p?N, on every compact Lipschitz manifold. Another class CB?,p is defined (for all ?>0, p>1) in terms of a diffusion process on a C²-manifold. These classes coincide when both are defined. If the manifold is the boundary of a bounded C²-domain E⊂Rd, then both versions of the Bessel capacities are equivalent to the Poisson capacities.     

Production of monoclonal antibodies against hop-derived (Humulus lupulus L.) prenylflavonoids and the development of immunoassays

Monoclonal antibodies against the hop-derived prenylated chalcone xanthohumol (X) and the prenylated flavonoids isoxanthohumol (IX) and 8-prenylnaringenin (8-PN) were developed. Carboxylic acid haptens of X, IX and 8-PN were synthesized by linking a spacer to their C4′-OH group followed by subsequent coupling to bovine serum albumin (BSA) to form conjugates that were employed as immunogens in BALB/c mice to raise antibodies. The monoclonal antibodies that were secreted from the established hybridoma cell lines proved, in cross-reactivity studies, to possess highly specific binding capacities in an optimized competitive indirect ELISA. The immunoassays make use of immunogen-coated microtiterplates and a peroxidase-labeled anti-mouse IgG₁ secondary antibody with ABTS as a chromogenic substrate. For X the IC₅₀ value derived from the standard curve was 62.91 ng mL⁻¹, and for both IX and 8-PN 37.15 ng mL⁻¹. The assay was validated for the quantitative analysis of X, IX and 8-PN in urine and serum. A simple sample pretreatment procedure using a diethyl ether extraction was optimized and the recoveries and matrix effects were assessed. The validity of the established assay was tested and mean inter- and intra-assay variations in urine were 2.32% and 1.91%, respectively for X, 6.24% and 2.39%, respectively for IX and 7.18% and 0.74%, respectively for 8-PN. In serum, the mean inter- and intra-assay variations were 8.90% and 1.37%, respectively for X, 6.13% and 1.57%, respectively for IX and 6.13% and 2.43%, respectively for 8-PN. Furthermore, the method demonstrated excellent accuracy and significant correlation with measurements by an established and validated HPLC-MS method.