Finite element solution based on fast numerical technique for large-scale electromagnetic computation

A numerical technique of the target-region locating （TRL） solver in conjunction with the wave-front method is presented for the application of the finite element method （FEM） for 3-D electromagnetic computation. First, the principle of TRL technique is described. Then, the availability of TRL solver for nonlinear application is particularly discussed demonstrating that this solver can be easily used while still remaining great efficiency. The implementation on how to apply this technique in FEM based on magnetic vector potential （MVP） is also introduced. Finally, a numerical example of 3-D magnetostatic modeling using the TRL solver and FEMLAB is given. It shows that a huge computer resource can be saved by employing the new solver.

解决FAST TCP缓存溢出相关问题的改进pacing technique算法和α参数调整算法

分析FAST TCP在缓存溢出发生时的性能,发现在缓存溢出场景中,收敛中的FAST TCP流经历严重的报文段丢失。相反,已经收敛了的FAST TCP流维持着高吞吐量和低报文段丢失概率。这种不公平是由FAST TCP缩减其窗口时的零传输率导致的。通过修改FAST TCP pacing算法,可以解决此问题。文中提出的α-adjusting算法,通过动态调整FAST TCP协议中的α参数来避免频繁的缓存溢出。通过分析ns2仿真结果,证明该算法在公平性和稳定性方面可获得令人满意的性能。

A fast approach to optimize dye loading of photoanode via ultrasonic technique for highly efficient dye-sensitized solar cells

A distinctive method is proposed by simply utilizing ultrasonic technique in Ti02 electrode fabrication in order to improve the optoelectronic performance of dye-sensitized solar cells （DSSCs）. Dye molecules are at random and single molecular state in the ultrasonic field and the ultrasonic wave favors the diffusion and adsorption processes of dye molecules. As a result, the introduction of ultrasonic technique at room temperature leads to faster and more well-distributed dye adsorption on TiO2 as well as higher cell efficiency than regular deposition, thus the fabrication time is markedly reduced. It is found that the device based on 40 kHz ultrasonic （within 1 h） with N719 exhibits a Voc of 789 mV, Jsc of 14.94 mA]cm2 and fill factor （FF） of 69.3, yielding power conversion efficiency （PCE） of 8.16%, which is higher than device regularly dyed for 12 h （PCE = 8.06%）. In addition, the DSSC devices obtain the best efficiency （PCE = 8.68%） when the ultrasonic deposition time increases to 2.5 h. The DSSCs fabricated via ultrasonic technique presents more dye loading, larger photocurrent, less charge recombination and higher photovoltage. The charge extraction and electron impedance spectroscopy （EIS） were performed to understand the influence of ultrasonic technique on the electron recombination and performance of DSSCs.

Simplified heavy metal staining techniques demonstrated with Fast Plant leaf tissue

Fast Plant(Brassica rapa,Cruciferae)leaf tissuefixed in glutaraldehyde-acrolein and post-fixed in os-mium,was examined for response to several easily-prepared heavy metal stains.Lead and uranium,separately and in combination,gave typical resultsacross the spectrum of cell organellets.As a single stainfollowing osmium,bismuth produced images seeminglyequivalent to lead and uranium.Phosphotungstic acidproduced very good membrane delineation but produceda washed-out background image similar to that from leadstaining.Carbohydrate compounds were especiallyresponsive to ruthenium;the cytoplasm and the matrixof all organelles were also stained very well.Theprocedures were no more demanding than traditionalstaining methods and may be easily used in research andteaching.Fast Plant materials are a reliable,quick andeasy source of living material.

Enhancement of neutron irradiation uniformity for the CFBR-Ⅱ fast burst reactor with a biaxial rotational technique

A biaxial rotational technique is proposed to improve the neutron irradiation uniformity for a large sample,and the theoretical method is established to predict and design the main parameters. The technique used a device to rotate the target sample around two perpendicular axes simultaneously. Numerical calculations found that the lowest common multiple of the two angular speeds should be large enough to improve the uniformity,and the minimal experimental time should be no less than 600 s. For a three-dimensional sample with a size of 20 cm × 12 cm × 14 cm, the maximal non-uniform neutron irradiation factor of the sample is mainly determined by the distance between the center of the sample and of the point neutron source. It was computed to be less than 10% when the distance was no less than 34 cm. Experiments were carried out on the CFBR-II reactor and the experimental results were in good accordance with the theoretical analysis. As a result, the theoretical conclusions given above are reasonable and of reference value for the design of future irradiation experiments.

基于UBmap/AHP/FAST的医院建筑火灾应急避难装置设计

为提高医院火灾应急避难能力,针对医院住院楼建筑,设计一款在火灾下能及时进行应急避难、安全逃脱的装置产品。集合用户行为地图(UBmap)、层次分析法(AHP)、功能分析系统技术法(FAST),融入整体设计构架中,探究应急避难装置产品的用户需求以及相关产品设计要素。将医院住院楼建筑环境特点及患者人群对火灾的逃生行为过程融入UBmap中,构建行为旅程图,推测并提取各个阶段需求指标;再通过AHP/FAST聚合方法,对需求指标进行重要度排序,并转化为主次功能进行分析求解,以此推断产品设计定位与功能逻辑的准确性,完成设计方案生产。综合UBmap/AHP/FAST为依据的理论模型,运用到医院住院楼建筑火灾下的避难装置设计开发流程中,并运用ANSYS Workbench软件有限元分析方案,进一步验证校核该设计的整体装置强度与可行性。结果表明:将不同的方法融合分析,系统性地对产品展开分析设计与实现且进行仿真检验,减少设计过程中的薄弱环节与不确定性问题,能够使设计更具系统性与科学性,达到降低避难装置的生产成本、实现安全效率化、防灾减灾的目标。

应用于人脑胶质淋巴系统的磁共振成像技术研究进展

胶质淋巴系统是神经科学领域近期发现的解剖结构,具有调节间质液运动、废物清除和潜在的大脑免疫等功能,在中枢神经系统的生理及病理中发挥重要作用。随着影像学技术的发展,越来越多的磁共振成像(MRI)技术被应用于人脑胶质淋巴系统的研究,目前常用的MRI技术有动态对比增强磁共振成像技术、沿血管周围间隙扩散张量成像分析技术及新型多模态超快速磁共振技术等,本文就这些技术在脑胶质淋巴系统的应用现状进行汇总综述,以期为胶质淋巴系统的影像学研究提供参考。

45°双驱动弹光调制高速椭偏测量方法

为解决传统机械旋转补偿器型椭偏仪测量速度较慢问题,提出一种电驱动的双弹光调制的高速椭偏测量方法。通过理论分析并仿真研究45°双驱动弹光调制器工作在纯行波模式下的调制方式。结果发现,当双驱动弹光调制器工作在纯行波模式可实现快轴方向的高速周期性旋转,且相位延迟量为常量。结合椭偏原理,详细研究一种基于双驱动弹光调制的高速椭偏测量理论模型,结果表明,该模型光学周期<10μs,用于实际可真正实现超高速偏光调制。通过研究,有望解决半导体集成电路,微电子和光伏电池等生产过程中薄膜超高速检测难题,对薄膜在线检测、瞬态变化测量具有重要意义和学术价值。

基于近红外光谱技术的固体推进剂燃速模型化快速预估方法

利用近红外光谱技术建立了基于近红外光谱的固体推进剂燃速快速预估模型,通过波谱范围筛选和光谱预处理对模型进行优化,并采用内部验证和外部验证对该模型进行评价,验证模型的精密度及准确度。结果表明,基于近红外光谱技术的固体推进剂燃速快速预估模型测试时间约为2 min,燃速偏差范围为-0.122~0.067 mm/s,精密度测试相对标准偏差≤0.4%,准确度测试偏差-0.029~0.057 mm/s。该方法能够在药浆混合阶段快速预测固体推进剂的燃速,提供了一种简单快捷和稳定可靠的燃速测定新方法。

篮球训练中运动员快攻技术养成方法研究

在篮球运动训练中,快攻是一种非常重要的进攻技术,也是衡量运动员和球队进攻能力的一个重要标准。在篮球训练中,运动员快攻技术的养成对于提高运动员的进攻能力和球队的整体战斗力都具有重要意义。为此,该文采用文献资料法等研究方法,对篮球训练中运动员快攻技术养成方法展开研究,旨在为今后开展篮球快攻技术训练提供一些参考性借鉴。

FasT-Fix全内缝合器治疗半月板损伤80例

目的探讨FasT-Fix全内缝合器修复半月板损伤的临床效果。方法回顾性分析2010年11月至2012年11月广州军区广州总医院采用FasT-Fix全内缝合器治疗的80例半月板损伤患者的临床资料，观察术后膝关节活动度及半月板愈合情况，评估手术前后Lysholm评分的差异。结果随访6～24个月（平均12个月），术后膝关节活动度正常，无交锁。76例患者半月板达到临床愈合标准，临床愈合率95％（76／80）；4例修复失败患者出现关节间隙压痛（十），其中2例合并关节积液及McMurray征（＋）。术后膝关节Lysholm评分为（85士13）分，明显高于术前的（32士12）分，两者比较，差异有统计学意义（f=4．234，P=0．000）；80例患者中优60例、良12例、可8例，优良率为90％（72／80）。结论Fast-Fix全内缝合器治疗半月板损伤具有微创、高效、安全等优点，尤其对于难以缝合的半月板后角损伤具有独特的优势。

粮食新鲜度判定仪在稻谷新鲜度检测中的应用

基于比色法原理,采用光谱技术,研制出一种粮食新鲜度判定仪,可快速筛选出新鲜稻谷、次新稻谷和非新鲜稻谷。选用稻谷样品对仪器进行了准确度、重复性、台间差和检测时间检验,另外,该仪器在质检机构开展了应用测试。说明该仪器具有良好的准确性和重复性,检测效率高,可适用于收购现场快速筛选新鲜稻谷。

应用ATA的对数周期馈源方案于FAST的可能性探讨

介绍应用于美国凤凰计划的Allen望远镜阵(ATA)的对数周期馈源(LPA)概况,初步给出此种馈源的基本参数及性能,仿真估算了其驻波比和方向图,并结合正在进行中的我国500m孔径球面射电望远镜(FAST)计划,探讨了应用这种宽带馈源的可能性及其限制。

双下肢多发骨梗死MRI类CT及能谱CT钙抑制成像应用一例

骨梗死临床发病率较低,多发生于长骨干骺端及骨干,骨梗死影像新技术报道也较为罕见。本文报道1例双下肢多发骨梗死MRI基于受限回波间距的快速梯度回波类CT成像及能谱CT钙抑制技术的影像表现,为临床提供诊断经验。

重庆主城至永川区快速通道方案研究

永川区是重庆主城都市区战略支点城市,目前重庆主城至永川区仅靠高速公路或低等级公路连接,缺乏高等级市政道路的衔接。该文分析重庆主城至永川区快速通道的功能定位和建设意义,重点研究项目通道走廊、起终点衔接、互通立交等关键节点方案,并通过采用BIM、倾斜摄影等新技术解决工程重点和难点。方案研究对类似通道建设具有一定的借鉴意义。

A Fast Super-Resolution Reconstruction from Image Sequence

Based on the mechanism of imagery, a novel method called the delaminating combining template method, used for the problem of super-resolution reconstruction from image sequence, is described in this paper. The combining template method contains two steps： a delaminating strategy and a combining template algorithm. The delaminating strategy divides the original problem into several sub-problems; each of them is only eonnected to one degrading factor. The combining template algorithm is suggested to resolve each sub-problem. In addition, to verify the valid of the method, a new index called oriental entropy is presented. The results from the theoretical analysis and experiments illustrate that this method to be promising and efficient.

Simulation of FAST EM performance for both the axial and lateral feed defocusing

Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the world’s largest single dish radio telescope,which is located in Guizhou Province,in southwest China.The FAST feed cabin is supported and positioned by six steel cables.The deviation of the feed position and orientation would lead to loss in the telescope efficiency.In this paper,a series of electromagnetic(EM)simulations of the FAST facility with varying feed positions and orientation offsets was performed.The maximum gain of FAST is about 82.3 dBi and the sibelobe is–32 dB with respect to the main beam at 3 GHz.The simulation results have demonstrated that the telescope efficiency loss is more sensitive to the lateral feed deviation compared with the axial deviation.The telescope efficiency would decrease by 8.2%due to the FAST feed position deviation of 10 mm rms when the observing frequency is 3 GHz.The FAST feed deviation basically has no effect on the sidelobes and cross polarization characteristic according to the simulations.

基于E-FAST-SURF算法的移动增强现实技术

针对当前移动设备硬件处理能力有限的问题,采用E-FAST-SURF算法实现对平面标记物的检测与跟踪,使与标记采集特征点的匹配速度得到了提高。实验结果表明,该算法能适应复杂环境,以及对移动设备增强现实应用中的标记进行特征的提取。

关节镜下FasT-Fix半月板内缝合技术治疗膝半月板损伤的临床分析

目的：分析关节镜下FasT-Fix半月板内缝合技术治疗膝半月板损伤的临床效果。方法选取我院2012年12月～2013年12月收治98例膝半月板损伤患者，予以所有患者进行关节镜下FasT-Fix半月板内缝合技术治疗，观察患者治疗后的临床效果。结果经过治疗后，98例患者中，88例优，7例良，3例中。术后膝关节评分为（82.5±0.5）分，明显比术前评分（50.0±0.5）分高，差异有统计学意义（P＜0.05）。其中，仅有1例出现植入体T2“卡壳”，3例置入T2后于种植部脱落，并经调整植入点后取得良好的治疗效果。96例McMurray’s试验阴性，98例Apley’s试验阴性。结论关节镜下FasT-Fix半月板内缝合技术治疗膝半月板损伤的临床效果显著，具有微创、操作便捷等优点，可以有效地避免植入体“卡壳”“绕结”“脱落”等，因此具有十分重要的临床应用价值。