NoC边界扫描测试系统硬件设计

为了解决内部结构日益复杂的片上网络系统故障测试的问题,在研究3×3 2D-Mesh体系结构的NoC系统、边界扫描测试技术和资源节点故障类型的基础上,以FPGA为核心器件设计边界扫描测试系统。完成了数据采集、频率计、放大器、SRAM、IEEE1500 Wrapper等资源节点电路以及资源节点边界扫描链路的接口电路设计,并利用测试软件、信号发生器、万用表和数字示波器,通过边界扫描链路完成对整个硬件设计的测试。测试结果表明该设计性能稳定,为研究NoC系统的边界扫描测试技术提供了硬件平台。     

基于条纹式激光传感器与机器人的扫描成像系统

提出了一种以条纹式激光传感器和工业机器人为平台对工件进行扫描检测并对其轮廓进行成像的系统方案。条纹式激光传感器移动式扫描工件获取工件轮廓的三维点云数据,然后结合特定的算法对点云数据进行去噪、插值、插补处理,使得点云数据能更加真实地反映工件的客观形貌,最终根据点云数据的信息生成工件轮廓的二值化图像。在实验中成像精度能达到0.1 mm 级,从而在某些特殊的工业场合替代传统的CCD 相机实现对工件的成像及检测定位,解决了传统CCD 的抗干扰能力不足的问题。     

Physicochemical and Graph Theoretical Descriptors in Developmental Toxicity SAR: A Comparative Study

Abstract

Chemical insults to the developing fetus can lead to growth retardation, malformation, death, and functional deficits. The present study seeks to determine if physicochemical and/or graph theoretical parameters can be used to determine a structure-activity relationship (SAR) for developmental toxicity, and if consistency is observed among the selected features. The biological data utilized consists of a diverse series of compounds evaluated within the Chernoff-Kavlock in vivo mouse assay. Physicochemical parameters calculated correspond to electronic, steric, and transport properties. Graph theoretical parameters calculated include the simple, valence, and kappa indices. Both sets of parameters were independently applied to derive SARs in order to compare the quality of the respective models. Multiple random sampling, without replacement, was utilized to obtain ten training/test partitions. Models were built by linear discriminant analysis, decision trees, and neural networks respectively. Comparisons on identical sets of data were carried out to determine if any of the model building procedures had a significant advantage in terms of predictive performance. Furthermore, comparison of the features selected within and across the model building processes led to the determination of model consistency. Our results indicate that consistent features related to developmental toxicity are observed and that both physicochemical and graph theoretical parameters have equal utility.     

Enantioseparation of chiral aromatic acids by multiple dual mode counter‐current chromatography using hydroxypropyl‐β‐cyclodextrin as chiral selector

This work concentrates on extending the utilization of multiple dual mode (MDM) counter‐current chromatography in chiral separations. Two aromatic acids, 2‐(6‐methoxy‐2‐naphthyl)propionic acid (NAP) and 2‐phenylpropionic acid (2‐PPA), were enantioseparated by MDM counter‐current chromatography using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as chiral selector. The two‐phase solvent systems consisting of n‐hexane/ethyl acetate 0.1 mol/L phosphate buffer pH 2.67 containing 0.1 mol/L HP‐β‐CD (7.5:2.5:10 for NAP and 7:3:10 for 2‐PPA, v/v/v) were used. Conventional MDM and modified MDM were compared according to peak resolution under current separation mechanism. The influence of elution time after the first‐phase inversion and number of cycles for MDM were investigated. Peak resolution of NAP and 2‐PPA increased from 0.62 to 1.05 and 0.72 to 0.84, respectively, using optimized MDM conditions. Being an alternative elution method for counter‐current chromatography, MDM elution greatly improved peak resolution in chiral separations.     

Quantitative fingerprinting by headspace—Two-dimensional comprehensive gas chromatography–mass spectrometry of solid matrices: Some challenging aspects of the exhaustive assessment of food volatiles

The study proposes an investigation strategy that simultaneously provides detailed profiling and quantitative fingerprinting of food volatiles, through a “comprehensive” analytical platform that includes sample preparation by Headspace Solid Phase Microextraction (HS-SPME), separation by two-dimensional comprehensive gas chromatography coupled with mass spectrometry detection (GC × GC–MS) and data processing using advanced fingerprinting approaches.     

ADSORPTION OF SURFACE-ACTIVE AGENTS FROM AQUEOUS SOLUTION: HYDROPHOBIC SUBSTRATES∗

Isotherms for the adsorption of sodium dodecyl benzene sulfonate, sodium POE (4) nonyl phenol sulfate, and POE (25) nonyl phenol, on the hydrophobic crystalline herbicides atrazine and cyanazine were determined. Anionic surfactants were measured at 5°, 25°, and 50° C; the nonionic surfactant at 25° C only. Low degrees of surface coverage were observed; in only one case (atra-zine/NaDBS) was monolayer coverage approached. On the other hand, adsorption was accompanied by a significant increase in negative zeta potential. Although DLVO calculations suggest that this adsorption should lead to stable aggregates, these are of such size that gravitational effects overpower the DLVO terms.     

Influence of branched chains on the mesomorphic properties of symmetrical and unsymmetrical triphenylene discotic liquid crystals

A series of novel symmetrical and unsymmetrical triphenylene‐based discotic liquid crystalline materials with one or six branched peripheral alkoxy chains have been prepared. These materials have been compared with analogous known symmetrical and unsymmetrical compounds to reveal a balance between steric and space‐filling effects of the peripheral branched chains, which significantly affects intermolecular forces of attraction and packing, and hence affects melting and isotropisation temperatures of the liquid crystalline materials. The desired result of reduction of melting points and enhancement of isotropisation temperatures has been accomplished by use of branched alkoxy chains in both symmetrical and unsymmetrical materials.     

支化侧链偶氮无规共聚物中空和类囊泡聚集体研究

研究了支化侧链型偶氮无规共聚物(PMAPB6P-AA)在THF/H2O混合溶液中的自组装行为.研究发现,通过缓慢增加体系的水含量,可以制备出具有中空结构的非球形聚集体.调节聚合物的初始浓度,可以得到不同粒径的聚集体.聚集体中偶氮生色团的光致异构化速率与异构化程度随聚合物初始浓度的增大而减小.在此基础上,采用更加缓慢的增加水含量的方法,使聚合物分子进行充分的疏水聚集与H-聚集,制备出类囊泡状聚集体.在紫外光照射条件下,观察到类囊泡聚集体发生了光致解聚集.     

非齐次树上马氏链的若干强偏差定理

通过构造适当的非负鞅,将Doob鞅收敛定理应用于几乎处处收敛的研究,给出了一类非齐次树上马氏链场加权和滑动平均的若干强偏差定理.