基于非对称打包和FSVM的图像检索

在图像检索的相关反馈中,引入支持向量机分类方法虽可以提升图像的检索性能,但是传统的支持向量机存在正样本数少、样本非对称、过学习和弱实时性的局限。针对上述问题,提出了一种基于非对称打包的FSVM算法。该算法首先对负样本进行非对称打包处理,最后结合模糊理论与SVM实现图像检索。Corel图片集上的实验表明,当正样本数较小时,该新算法的平均查准率-查全率要优于已有算法。     

AB SLC500与Modbus网络通信的实现

AB SLC500不支持Modbus协议,所以不能直接与Modbus网络通信。为了实现两者快速准确的通信,深入研究了Modbus协议,并在AB SLC500 BASIC-T模块中开发了Modbus应用程序,实现了SIE500与Modbus网络的通信。应用SIE500编写梯形图程序来控制其他设备和网络,由于程序冗长,增加了信息传输的延迟,不利于实时传送。BASIC-T模块的应用,与过去直接应用SIE500控制其他设备和网络相比,提高了控制的效率和响应速度,即提高了控制系统整体的实时性。实验测试结果表明,此方案能保证数据传输的准确性、可靠性和高效性。     

一种高线性度AB类CMOS功率放大器的设计与实现

率放大器作为发射机中最核心的模块之一,如何同时提高其效率和线性度一直是人们研究的热点。文章主要分析了AB类功率放大器中的主要非线性源—栅源电容对电路性能的影响,并且使用了一个PMOS管并联的技术来补偿这种影响,最后利用这种技术,采用JAZZ0.25um RF CMOS工艺实现了一个可应用于2.45GHz WLAN的高效率高线性度的AB类功率放大器,三阶交调(IM3)项为-12dBm,输出功率为26dBm,功率附加效率(PAE)为44%。     

Analysis of different containment models for IRIS small break LOCA, using GOTHIC and RELAP5 codes

Advanced nuclear water reactors rely on containment behaviour in realization of some of their passive safety functions. Steam condensation on containment walls, where non-condensable gas effects are significant, is an important feature of the new passive containment concepts, like the AP600/1000 ones.In this work the international reactor innovative and secure (IRIS) was taken as reference, and the relevant condensation phenomena involved within its containment were investigated with different computational tools. In particular, IRIS containment response to a small break LOCA (SBLOCA) was calculated with GOTHIC and RELAP5 codes. A simplified model of IRIS containment drywell was implemented with RELAP5 according to a sliced approach, based on the two-pipe-with-junction concept, while it was addressed with GOTHIC using several modelling options, regarding both heat transfer correlations and volume and thermal structure nodalization. The influence on containment behaviour prediction was investigated in terms of drywell temperature and pressure response, heat transfer coefficient (HTC) and steam volume fraction distribution, and internal recirculating mass flow rate. The objective of the paper is to preliminarily compare the capability of the two codes in modelling of the same postulated accident, thus to check the results obtained with RELAP5, when applied in a situation not covered by its validation matrix (comprising SBLOCA and to some extent LBLOCA transients, but not explicitly the modelling of large dry containment volumes).The option to include or not droplets in fluid mass flow discharged to the containment was the most influencing parameter for GOTHIC simulations. Despite some drawbacks, due, e.g. to a marked overestimation of internal natural recirculation, RELAP5 confirmed its capability to satisfactorily model the basic processes in IRIS containment following SBLOCA.     

Novel AB crosslinked polymer networks based on 1‐vinylimidazole‐ terminated polyurethane and poly(methyl methacrylate)

1‐Vinylimidazole‐terminated telechelic polyurethanes were prepared from 1‐vinylimidazole and bromine‐terminated polyurethane. This vinyl‐terminated telechelic polyurethane (VTPU) and methyl methacrylate were polymerized in the presence of benzoyl peroxide to prepare novel AB crosslinked polymer networks (ABCPs). These were characterized by spectral, thermal and mechanical studies. The absence of the characteristic peak of vinyl group in infrared spectra of ABCP films confirms the occurrence of crosslinking. Static mechanical testing showed that the tensile strength of ABCP increases with increasing poly(methyl methacrylate) content. Dynamic mechanical studies revealed that ABCPs, at equal compositions of VTPU and methyl methacrylate, show good damping properties. Copyright © 2006 Society of Chemical Industry     

La0.8Mg0.2(Ni27Co0.6Al0.1Mn0.1)x贮氢合金的节能分析

以La0.8Mg0.2(Ni27Co0.6Al0.1Mn0.1)x(X=0.9、0.95、1.00、1.05、1.10)贮氢合金为研究对象.采用电化学测试技术,揭示合金的成分与电化学性能的关系.在所研究的合金中,以X=1.00时合金的综合性能较好,其最大放电容量为357mAh/g,活化次数为2次,在1200mA/g放电...     

Titanium-iron-manganese (TiFe0.85Mn0.15) alloy for hydrogen storage: Reactivation upon oxidation

Titanium-iron (TiFe) is known to be a low-cost alloy that can be reactivated to nearly full hydrogen storage capacity after oxidation. However, this reactivation requires multiple heat treatments at high temperatures under vacuum even upon partial substitution of Fe with a small amount of manganese to form TiFe_0.85Mn_0.15. This process is cumbersome in the context of practical applications, and better strategies for the facile activation of TiFe are required. Herein, we report on an improvement in the reactivation strategy of TiFe_0.85Mn_0.15 by using a single heat treatment process after air oxidation of the alloy. After full oxidation of the material under air for 2 h, reactivation was achieved in a single step by heating the alloy to 300 °C under hydrogen pressure. During that process, the reduction of Fe was believed to lead to new reactive paths at the surface of the alloy facilitating the permeation of hydrogen. As a result, full cycling capability of the material was quickly re-gained, and the hydrogen capacity loss was of only 0.1 mass%.     

涤粘AB双色纱的生产与质量控制

探讨涤粘AB双色纱的生产工艺和质量控制措施。分析阐述了涤粘AB双色纱的特点以及生产技术和管理难点。从原料、工艺、生产管理入手采取一系列措施,成功纺制出涤/粘50/50 11.8tex AB双色纱。认为,合理选配原料及混和工艺,针对原料特点优化各工序工艺配置,严格控制色差和疵点,加强生产现场和回花再用棉管理,采取必要的防污染隔离措施,可以纺制出质量满足要求的涤粘AB双色纱。     

粘涤11.8tex AB双色纱的生产实践

探讨粘涤11.8tex AB双色集聚赛络纱的生产工艺。介绍了纺粘涤AB纱所配用5种原料的性能指标和纺纱工艺流程。通过对B组原料采取预混措施,A、B单独混棉纺成粗纱,对纺纱各工序优化配置工艺,制定相应的技术管理措施,成功纺制出粘涤11.8tex AB双色集聚赛络纱,满足了用户需求。认为:生产AB双色纱,配色和对色是基础,工艺和管理是关键,应认真实施有关工艺和技术管理措施。