Medusa: a scalable MR console using USB

Magnetic resonance imaging (MRI) pulse sequence consoles typically employ closed proprietary hardware, software, and interfaces, making difficult any adaptation for innovative experimental technology. Yet MRI systems research is trending to higher channel count receivers, transmitters, gradient/shims, and unique interfaces for interventional applications. Customized console designs are now feasible for researchers with modern electronic components, but high data rates, synchronization, scalability, and cost present important challenges. Implementing large multichannel MR systems with efficiency and flexibility requires a scalable modular architecture. With Medusa, we propose an open system architecture using the universal serial bus (USB) for scalability, combined with distributed processing and buffering to address the high data rates and strict synchronization required by multichannel MRI. Medusa uses a modular design concept based on digital synthesizer, receiver, and gradient blocks, in conjunction with fast programmable logic for sampling and synchronization. Medusa is a form of synthetic instrument, being reconfigurable for a variety of medical/scientific instrumentation needs. The Medusa distributed architecture, scalability, and data bandwidth limits are presented, and its flexibility is demonstrated in a variety of novel MRI applications.     

2011中国(厦门)卫生用品博览会暨浆纸技术装备展览会成功举办

由福建省纸业协会、广东省造纸行业协会、山东省轻工机械协会、河南省造纸学会联合主办,浙江省造纸行业协会、江苏宜兴丹森科技有限公司协办,厦门博卫展览服务有限公司承办的2011中国(厦门)卫生用品博览会暨浆纸技术装备展览会于7月28日上午在厦门国际会展中心隆重开幕。开幕式由福建省纸业协会常务副会长李谦逊主持,福建省轻工业联合会会长王学鼎致辞。28日下午举行了造纸及纸制品行业装备技术推介会广东省造纸行业协会吕永松副会长主持了会议汶瑞机械(山东)有限公司、山东省轻工业机械协会、香港森鑫国际企业集团广州森鑫日化有限公司、     

基于碳纳米管的微纳单元的实验研究

利用碳纳米管生长技术和微加工技术,开展了微纳单元的实验方法研究,探索了"管压电极"和"电极压管"的微纳单元制备工艺.结构表征和电学特性测试结果表明,这两种工艺均可以加工出具有欧姆接触或者是肖特基接触的微纳单元,但"管压电极"工艺具有过程简单、成本低等特点,为基于碳纳米管的微纳单元的集成化制备工艺提供了新的思路.     

如何升级MODEM的BIOS

升级Modem的BIOS可以可使它兼容新的协议标准，明显改善Modem性能（包括ADSL、ISDN、CABLE等Modem都适用，56KModem还可以通过升级BIOS来支持V92协议）。不同的厂商提供的刷新程序可能有所不同，但刷新的步骤都大同小异。升级需要什么？不是所有的MODEM都能利用软件升级Firmware，在通讯速率低于28.8K的时代，MODEM大多不具备软件升级Firmware能力的。直到33.6KMODEM流行、56K通讯协议即将出台的情况发生后，MODEM厂商才纷纷推出能够使用户利用软件自行升级Firmware的MODEM，以便用户利用老式的MODEM获取56K的速…     

Information technology and road transport industry: how does IT affect the lorry driver?

A quasi-experimental design was used to study the effect of on board computer-systems (OBC-systems) on the Dutch lorry drivers' psychosocial work environment (i.e., control and demands) and coinciding mental health (i.e., need for recovery after work) and job attitudes (i.e., organisational commitment). The intervention group (n = 26) started working with an OBC-system between 1998 and 2000 and was compared with two matched reference groups (n = 26 in both groups). All participants were from a cohort of 650 drivers who participated in a prospective study on occupational stress and health. All outcome variables were quantified by standardised and validated questionnaires. Results showed that the application of OBC-systems negatively affected the drivers' job control and organisational commitment. However, OBC-systems did not influence the drivers' psychological job demands and need for recovery after work. Accordingly, it is concluded that the application of OBC-systems negatively affects the lorry driver's psychosocial work environment and job attitudes.     

Investigations on factors affecting chitosan for dissolution enhancement of oxcarbazepine by spray dried microcrystal formulation with an experimental design approach

In the present work effect of chitosan on microcrystal formulation for dissolution enhancement of oxcarbazepine using controlled crystallization technique coupled with spray drying was explored. The work was extended for exploration of simplified approach for stable particle size reduction. The study was performed with an experimental design approach i. e. a fractional factorial design of resolution 5 (with all 2 factor interaction) for the screening of predefined independent variables drug concentration, chitosan concentration, feed rate, inlet temperature and percent aspiration for spray drying. Whereas percent drug dissolved, wettability time, flowability in terms of angle of repose and particle size were designated as response variables. Resultant models were analyzed using multiple linear regression analysis, which generated equation to plot response surface curves along with desirability function. Results showed that chitosan concentration had significant effect on dissolution enhancement of oxcarbazepine at a level of 2% w/v. Increase in drug concentration showed decreased dissolution rate however on particle size it did not show statistically significant effect. Topographical characterization was carried out by SEM which showed that feed rate, percent aspiration and inlet temperature had significant effect on particle morphology. For deriving optimized formulation results were analyzed using desirability function for the maximum percent drug dissolved and least drug polymer matrix particle size. DSC studies showed that drug was molecularly associated with chitosan matrix or particles.     

降低集成化平面螺旋电感寄生串联电阻的途径

对集成化平面电感的串联电阻对电感Q值的影响进行了计算机模拟分析,结果表明,微型电感中的串联电阻对电感Q值的影响严重,在电感的串联电阻大于200Ω时,电感的Q值下降到1左右,已无法满足实际需要。围绕微型电感中对串联电阻起主要作用的导通电阻开展实验,得出了降低导通电阻的最佳工艺条件,为研究通讯用的微型电感打下了基础。     

正电子致电离截面实验中束流强度的在线测量

本文采用HPGe探测器实时收集了正电子碰撞厚Ti靶伴随产生的湮灭光子,并结合HPGe探测器对放置在碰撞点处²²Na标准源产生的511 keV湮灭光子的探测效率刻度值,得到了8~9.5 keV正电子引起Ti原子内壳层电离截面实验中正电子束流强度的实时测量结果。结果表明,在实验测量的38 h内,基于²²Na标准源慢正电子束流装置产生的正电子束流强度不稳定,随时间的变化有着不同程度的衰减,且存在小幅度波动现象。因此,低能正电子致原子内壳层电离截面实验中应采用在线法获取慢正电子束流强度。     

双雄动——茅台、五粮液“12.18”经销商大会解读

一次有预谋的“撞车”这是一次有预谋的“撞车”!在过去十余年间,茅台和五粮液在一年一度的经销商大会召开时间上,从未撞过车。自1996年起,五粮液每年的经销商大会都定在12月18日,而茅台则很有“默契”地将会议时间定在早于或晚于12月18日的某一天。这样的默契．更多是出于对经销商、尤其是同时代理茅台、五粮液的大商的体谅。     

TC10钛合金高温变形行为和组织演变的研究

通过恒应变压缩实验研究了锻态TC10钛合金的高温变形行为和组织演变规律,变形温度为800~920℃,应变速率为0.01~10 s~(-1),变形量为60%。研究结果表明:降低变形温度、提高应变速率,流变应力会在变形初期迅速增加,而显微组织没有明显变化,当流变应力达到最大值后随着动态再结晶的发生而逐渐降低。提高变形温度、降低应变速率,能够为动态再结晶提供能量,细化组织并降低流变应力。综合分析表明:在变形温度为840~900℃,应变速率为0.01~0.1 s~(-1)的参数范围内进行热变形可以获得性能优良的TC10钛合金产品。