基于FPGA&ASIC的专用USB接口设计与实现

无驱型USB KEY专用接口的设计和实现是基于FPGA&ASIC的. 该设计主要使用Verilog语言在FPGA上实现USB协议,并提供针对USB收发器和微控制器的接口. 通过该接口USB KEY在接入系统后不需要驱动程序即可正常使用. 该设计通过了软件的仿真并在FPGA上进行了硬件验证.     

一种基于人员定位的矿井综合通信系统

针对目前矿井井下通信系统功能不完善,技术与实现复杂的现状,提出了一种基于井下人员定位的综合通信监控系统。详细介绍了定位原理与具体实现过程,给出了系统中关键设备基站（BS）与人载通信器的结构原理图,并对综合通信与监控功能的实现进行了分析,最后给出了CMC管理软件的系统功能框图。     

Liquid-phase hot-pressing and WC-particle reinforcement of SiC-Si composites

The sintering behaviour of SiC-Si and SiC-Si-WC composites hot-pressed via silicon liquid phase has been studied. The results show that the increase of silicon makes the sintered materials densify at lower temperature and the grain growth is restricted due to the effect of the liquid. The strength of SiC-25 vol.% Si samples is higher than the strength obtained for SiC-5 vol.% Si with the same hot-pressing conditions. The addition of WC particles improves relative densities and strengths of SiC-Si ceramics.     

Safety-based availability assessment at design stage

The availability of a system or equipment is one of the crucial characteristics that measures the customer satisfaction and strongly influences his final choice decision between concurrent products. The aim of this work is to provide an approach to improve the products availability assessment by taking into account the safety criteria by considering the use situations at design stage. Our work focuses on the routine design of complex products. The availability is often simply estimated considering reliability and maintainability. Basically, the intrinsic availability is the probability that it is operating satisfactorily at any point in time when used under conditions stated by design specifications. The time considered includes operating time and active repair time. Thus, intrinsic availability excludes from consideration all other times in the product lifecycle such as: accident management time, storage time, administrative time or logistic time. But many studies show that the loss of availability performance is also due to accidents that occur in different unforeseeable utilization situations. This engenders stops of the system to ensure the users safety according to standards recommendations. In this purpose, we consider the structural product architecture and the different use cases that correspond to the operational states and downtimes due to stop events that may happen during the utilization like failures, maintenance tasks and accidents. Then, we propose a product behavioral analysis including the use cases to describe interactions between the product and users or maintenance operators. We use Markov chains to model the use cases corresponding to operating time (OT), maintenance time (MT) and preparing time after accidents (RT). Then these three parameters are considered to specify a generic approach to improve the availability assessment. Such an approach provides the traceability of the product behavior along its lifecycle. In this way, the main causes of stop can be identified and this may guide the designer for improving the availability of the product future versions. To validate our approach, an application is presented considering a printing line. The comparison of our simulation considering an industrial case study shows a good agreement about the influence of safety on the availability.     

家用电器保温隔热用聚合MDI的研制

根据分子设计的原理，通过研究聚合MDI组成与性能之间的关系，优化了聚合MDI的合成工艺，进而研制出家用电器保温隔热用聚合MDI，并对其进行性能评价。结果表明，所研制的聚合MDI可以替代进口产品，用于家用电器的保温隔热。     

锦纶6聚合中冷冻停车工艺的改进

以往锦纶6短丝车间冷冻停车工艺采用自然降温方式,导致停车过程中经常发生设备故障。通过工艺改进,采用自上而下的梯度式降温方式,避免了降温速度不均匀的问题。改进后的工艺克服了原工艺的不足,完全满足了生产技术要求,具有较高的实际应用价值。     

Mixed monolayer and mixed micelle formation in binary mixture of surfactants—Systems for trioxyethylenated dodecyl sulfonate and some polyoxyethylenated fatty alcohol ether nonionic surfactants

The interaction and synergism of some polyoxyethylenated fatty alcohol ether (POE) nonionic surfactants (C₁₂E₂, C₁₂E₃, C₁₀E₅, C₁₀E₇, where C_x indicates number of carbon atoms in the chain and E_y indicates number of oxyethylene glycol ethers) with trioxyethylenated dodecyl sulfonate (C₁₂E₃S) in mixed monolayer formation at the surface and in mixed micelle formation in aqueous solutions were studied at 25 and 40°C by calculating interaction parameters (β_α, β_M) from surface tension-concentration data by use of Rosen's equations based on the nonideal solution theory. All the systems investigated adapt reasonably well to the nonideal model, with negative values of β_σ and β_M (where M means micelle and σ refers to the air-liquid interface) indicating a favorable interaction between the mixed surfactants. Either at a monolayer or in a mixed micelle, the attractive interaction becomes stronger when the alkyl chain in the POE surfactant is longer, i.e., when the POE becomes more hydrophobic. The interaction increases in the order C₁₀E₇<C₁₀E₅<C₁₂E₃, C₁₂E₂. For the two C₁₀E _n (n= 5,7)/C₁₂E₃S systems, as temperature increases from 25 to 40°C, the interaction increases in a mixed micelle, but it decreases in a mixed monolayer. Synergism in mixed micelle formation exists for C₁₂E₃S/C₁₀E _n mixtures when X₁ ^M , the mole fraction of POE in a mixed micelle, is ≈0.4–0.8, whereas synergism does not occur in the systems of C₁₂E₃S/C₁₂E _m due to the large difference between CMC₁ and CMC₂, i.e., large |In(C ₁ ^M /C ₂ ^M )| value (where CMC=critical micelle concentration). The degree of synergism in mixed micelle formation is temperature independent and is 0.23, 0.18, and close to zero for C₁₀E₅/C₁₂E₃S, C₁₀E₇/C₁₂E₃S, and C₁₂E _m (m=2,3)/C₁₂E₃S systems, respectively. Synergism in surface tension reduction effectiveness occurs in C₁₂E₃S/C₁₂E₂ and C₁₂E₃S/C₁₂E₃ systems. The mole fractions of POE in the solution phase are 0.302 and 0.333 for the two mixtures at the point of maximum synergism.     

Preparation,morphology, and mechanical properties of elastomers based on α,ω‐dihydroxy‐polydimethylsiloxane/polystyrene blends

α,ω‐Dihydroxy‐polydimethylsiloxane/polystyrene (PDMS/PS) blends were prepared by the solution polymerization of styrene (St) in the presence of α,ω ‐dihydroxy‐polydimethylsiloxane (PDMS), using toluene as solvent and benzoyl peroxide (BPO) as initiator. The PDMS/PS blends obtained by this method are a series of stable, white gums, which were vulcanized to elastomers at room temperature with methyl‐triethoxysilicane (MTES). The use level of MTES was far more than the necessary amount used to end‐link hydroxy‐terminated chains of PDMS, with the excess being hydrolyzed to crosslinked networks, which were similar to SiO₂ and acted as filler. Investigations were carried out on the elastomeric materials by extraction measurement, swelling measurement, and scanning electron microscopy. The extraction data show that at each composition the amount of soluble fraction is less than expected and the difference between experimental and theoretical values becomes more and more significant as PS content increases. This is mainly due to the grafting of PS onto PDMS and the entanglement of PS in the interpenetrating polymer network (IPN), which consists of either directly linked PDMS chains or chains linked via PS grafts and is formed by free radical crosslinking of PDMS during the radical polymerization of St. PS grafted on PDMS is insoluble and PS entangled in the IPN is difficult to extract. Both render the soluble fraction to be less than expected. As the St content in preparing PDMS/PS blends increases, the probability of grafting PS onto PDMS also increases, which may subsequently produce a higher crosslinking level of PDMS networks that linked via PS grafts by radical crosslinking. As a result, not only the amount of insoluble PS increases but also PS entangled in the IPN is more difficult to extract. Scanning electron microscopy demonstrates that the elastomer system has a microphase‐separated structure and a certain amount of PS remains in the PDMS networks after extraction, which is in accordance with the extraction data. Moreover, the mechanical properties of the elastormeric materials have been studied in detail. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3542–3548, 2004