糖尿病活体胰腺体积测量的临床应用

应用ＮＡＩ－２００医用数字图象处理系统对２４例国人糖尿病的胰腺ＣＴ影象进行了前瞻性研究，首次得出了精确的活体胰腺体积为１２．７９±２．２８ｃｍ３／ｍ２．正常人为１６．４４±４．１４ｃｍ３／ｍ２．经ｔ检验后具有明显的差异性Ｐ＜０．０１．提示国人糖尿病对叶伴有明显的胰腺体积缩小。     

基于G2G信息共享需求识别的G2B业务流程设计研究*

为了给公众和企业提供更好的服务,给政府决策者提供更准确及时的支持,政府部门间G2G信息共享势在必行。然而,由于政府业务繁多且程序复杂,许多政府部门对政府信息分布及共享需求并不清晰,给电子政务流程设计造成了一定的难度。为此,试图从跨组织信息资源管理的角度出发,首先对G2B传统业务流程中业务依托信息和产生信息进行分析,以确定各职能部门的信息需求状况;其次,通过分析不同部门间的业务信息关系,分别建立依托信息与依托信息、依托信息与产生信息以及产生信息与产生信息三种信息交集关系,从而识别部门间信息共享需求并分析可能     

Web用户行为预测的一种新模型及算法

有效地预测互联网用户在浏览过程中的行为方向,尽可能有针对性的提供其感兴趣的信息,有助于提高网站的服务质量,最大限度地留住客户.马尔科夫模型是解决这一问题的一种有效建模方式.但是该模型,尤其是高阶马尔科夫模型的指数级复杂度大大影响了其实际的应用.建立新的模型需要权衡自身的预测准确度与复杂度,尽可能保持前者,同时降低后者.结合马尔科夫模型和有向图特点,提出了一种新的建模方式.新模型具有与马尔科夫模型相同的预测准确度,但是各种时间、空间复杂度相对较低,综合性能良好.     

ARSlice: Head-Mounted Display Augmented with Dynamic Tracking and Projection

Computed tomography (CT) generates cross-sectional images of the body. Visualizing CT images has been a challenging problem. The emergence of the augmented and virtual reality technology has provided promising solutions. However, existing solutions suffer from tethered display or wireless transmission latency. In this paper, we present ARSlice, a proof-of-concept prototype that can visualize CT images in an untethered manner without wireless transmission latency. Our ARSlice prototype consists of two parts, the user end and the projector end. By employing dynamic tracking and projection, the projector end can track the user-end equipment and project CT images onto it in real time. The user-end equipment is responsible for displaying these CT images into the 3D space. Its main feature is that the user-end equipment is a pure optical device with light weight, low cost, and no energy consumption. Our experiments demonstrate that our ARSlice prototype provides part of six degrees of freedom for the user, and a high frame rate. By interactively visualizing CT images into the 3D space, our ARSlice prototype can help untrained users better understand that CT images are slices of a body.     

Insight into crystal growth and upconversion luminescence property of tetragonal Ba3Sc2F12 nanocrystals

Sc-based nanomaterials have attracted consid-erable attention due to their unique optical properties dif-ferent from those of Ln/Y-based nanomaterials.However,s...     

改性环氧富锌底粉在高耐盐雾锈蚀方面的研究

防腐型熔结环氧粉末涂料与富锌环氧粉末涂料应用多年,但在很多高耐盐雾锈蚀环境仍无法完全替代溶剂型涂层.为提升粉末涂料耐盐雾性能,本研究通过对环氧富锌粉末涂料进行改性,在降低涂层体积电阻率的基础上提升牺牲阳极效率,使涂层达到液体涂料耐盐雾等级性能.结果 表明:添加0.2％导电材料单壁碳纳米管与30％片状锌粉以及其他功能助剂...     

中空海胆状结构的碳包覆Fe2O3用作锂离子电池的高性能负极材料

Fe2O3由于成本低廉,储量丰富和理论比容量高(1007 mA hg^-1)等特点,在锂离子电池负极材料的应用中极具发展前景.然而一些问题仍然存在,如:充放电过程中比容量的迅速衰减,不可逆的体积膨胀以及较短的循环寿命等.这些问题严重制约了Fe2O3在锂离子电池中的实际应用.为了突破这些局限,本文以金属-有机骨架(MOF...     

基于EEMD和BPNN的动态误差溯源研究

针对动态测试系统在测试过程中存在误差导致精度损失的问题,提出了一种基于集合经验模态分解和BP神经网络的动态误差溯源方法.该方法在全系统动态精度理论的基础上,首先通过EEMD对动态测试系统输出总误差进行分解,对分解得到的单项误差进行希尔伯特变换,分析误差信号的幅频特性,然后采用BP神经网络拟合溯源.通过仿真分析,结果表明该方法可以有效地追溯到动态测试系统中误差产生的模块,并且偏差精度达到10-2,比经验模态分解的方法溯源效果更好,避免了EMD存在的模态混叠等问题,具有可行性和应用性.     

Dried Blood Spots as Matrix for Evaluation of Valproate Levels and the Immediate and Delayed Metabolomic Changes Induced by Single Valproate Dose Treatment

The immediate and delayed metabolic changes in rats treated with valproate (VPA), a drug used for the treatment of epilepsy, were profiled. An established approach using dried blood spots (DBS) as sample matrices for gas chromatography/mass spectrometry-based metabolomics profiling was modified using double solvents in the extraction of analytes. With the modified method, some of the previously undetectable metabolites were recovered and subtle differences in the metabolic changes upon exposure to a single dose of VPA between males and female rats were identified. In male rats, changes in 2-hydroxybutyric acid, pipecolic acid, tetratriacontane and stearic acid were found between the control and treatment groups at various time points from 2.5 h up to 24 h. In contrast, such differences were not observed in female rats, which could be caused by the vast inter-individual variations in metabolite levels within the female group. Based on the measured DBS drug concentrations, clearance and apparent volume of distribution of VPA were estimated and the values were found to be comparable to those estimated previously from full blood drug concentrations. The current study indicated that DBS is a powerful tool to monitor drug levels and metabolic changes in response to drug treatment.     

PVC卷帘门窗型材挤出技术

对PVC卷帘门窗型材挤出技术进行了研究。介绍了PVC卷帘门窗型材的配方设计要点、产品性能、生产工艺流程、重点工艺参数控制和挤出成型设备的性能特点。