用VHDL和CPLD的电路简化方法的研究

目的 使用VHDL降低目标电路的资源占用率和优化电路结构，方法。分析用VHDL和CPLD设计容易引起电路复杂化的原因，并提出了相应的解决方法，结果与结论 得到简化电路的一些有效的技巧与方法。     

电容传感器微弱电容测量电路的仿真研究

本文研究了电容传感器的三种微弱电容测量电路,分析和比较了它们的优缺点.基于对抗高过载低量程电容加速度传感器的设计要求,选择了一种基于电荷放大原理的电容测量电路方案,进行重点研究.并对该电路需要的元器件进行仔细的考虑和选择.运用Altera公司的软件MaxplusⅡ的VHDL语言,通过对复杂可编程逻辑器件CPLD进行编程,以产生开关控制时序,从而很好地实现了该测量电路的功能.     

基于CPLD的多波形发生器的设计

设计采用硬件编程语言VHDL,设计方波、三角波和正弦波,利用QuartusⅡ7.2软件对三种波形的程序进行仿真,通过CPLD芯片EPM1270T144C5和DAC0832及放大器实现信号的传输,最后示波器完成波形的显示。采用VHDL语言设计的电路能够灵活地修改参数,而且极大地提高了电路设计的通用性和可移植性。     

信号采集中峰值检测电路的设计与实现

为实现信号采集中峰值检测,改进峰值检测电路的指标,提高峰值检测电路的速度,捕捉更窄的毛刺信号,使用VHDL语言来编写程序,设计了一种基于FPGA的峰值检测电路.采用串并转换的思想,先把采集到的数据做串并转换以降低速度,并使用流水线技术,提高了电路的工作速度,实现了峰值检测的功能.该电路在实际项目中得到了验证,能捕获2.5 ns以上的毛刺信号,可广泛用于数字存储示波器中.     

基于FPGA的全同步数字频率计的设计与实现

利用全同步频率测量原理,通过FPGA(Field Programmalbe Gata Array)芯片,运用VHDL语言编程设计一个全同步数字式频率计,消除了±1的计数误差,测频范围在DC～100MHz,给出了各模块的VHDL设计方法和仿真波形.并且可以利用FPGA芯片构成系统板,具有较高的实用性和可靠性.     

基于FPGA和单片机的全同步数字频率计的实现

本数字频率计采用以FPGA为核心器件设计。设计的过程用VHDL语言实现测频，测周等模块，用单片机进行显示器等硬件控制，C语言实现其软件控制。对于Quartus II设计工具而言，与Verilog及VHDL的设计流程是完全支持的，Quartus II设计工具内部嵌入了Verilog逻辑综合器，Quartus II最大的优势之一在于能够利用第三方工具。基于QuartusⅡ的VHDL的设计方法电子系统的设计方法和“自顶向下”与“自底向上”的设计方法。     

用FPGA实现大容量闪存控制器

本文介绍了作者利用FPGA设计的大容量闪存控制器.该控制器采用VHDL进行设计,并用Altera公司的EPF10K20器件完成硬件电路.它的主要功能足用硬件实现NAND型闪存复杂的读、写及擦除时序,简化了外部接口,提高了读写速度及工作可靠性.该控制器可以用于海量数据采集系统中.     

基于FPGA自适应数字频率计的设计

介绍一种以FPGA（FieldProgrammableGateArray）为核心，基于硬件描述语言VHDL的数字频率计设计与实现。在介绍频率测量的原理和测量方法的基础上，针对所设计的频率计需简单易用的要求，采用FPGA和简单的外围电路使系统具有体积小、可靠性高、灵活性强及价格低廉等特点，同时还具有易于升级的特点。     

基于FPGA的1553B总线编、解码器设计

本文在基于FPGA的基础上设计实现1553B总线接口板中的曼彻斯特Ⅱ型码的编、解码器。设计采用VHDL语言,使用Quartus Ⅱ9.0对设计实现综合、优化、仿真,最后在FPGA硬件电路上实现测试。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.