内部激励源二自由度结构扬声器振动特性分析

有别于多数基于简单振子结构的扬声器,针对一类内部激励源二自由度(IE2DOF)结构的扬声器,用类比线路图法建立集总参数模型,计算分析了这种结构的频率响应,同时计算了其固有共振频率和固有反共振频率。使用叠加法分析内部激励源对频响的影响。最后实际测量和理论计算吻合,进一步支持了理论模型,揭示了IE2DOF结构扬声器的振动特性。     

挖掘机器人视觉目标定位

为实现挖掘机器人的自动挖掘,在挖掘机实验模型基础上进行了电路改造,构建了以单片机为核心的控制电路,通过无线蓝牙与上位机进行通讯,实现对挖掘机操作装置的控制。通过视觉传感器采集挖掘机铲斗、目标物的实时图像,经图像处理后,对目标物中心及铲斗标记中心进行提取、定位,计算出二者之间的实时距离,进而控制挖掘机铲斗对目标物进行挖掘。     

Limit distribution of the coefficients of polynomials with only unit roots

We consider sequences of random variables whose probability generating functions have only roots on the unit circle, which has only been sporadically studied in the literature. We show that the random variables are asymptotically normally distributed if and only if the fourth central and normalized (by the standard deviation) moment tends to 3, in contrast to the common scenario for polynomials with only real roots for which a central limit theorem holds if and only if the variance is unbounded. We also derive a representation theorem for all possible limit laws and apply our results to many concrete examples in the literature, ranging from combinatorial structures to numerical analysis, and from probability to analysis of algorithms. © 2013 Wiley Periodicals, Inc. Random Struct. Alg., 46,707–738, 2015     

Approximation properties for solutions to non‐Lipschitz stochastic differential equations with Lévy noise

In this paper, we consider the non‐Lipschitz stochastic differential equations and stochastic functional differential equations with delays driven by Lévy noise, and the approximation theorems for the solutions to these two kinds of equations will be proposed respectively. Non‐Lipschitz condition is much weaker condition than the Lipschitz one. The simplified equations will be defined to make its solutions converge to that of the corresponding original equations both in the sense of mean square and probability, which constitute the approximation theorems. Copyright © 2014 John Wiley & Sons, Ltd.     

Water-soluble pillar[6]arene stabilized silver nanoparticles: preparation and application in amino acid detection

In the presence of a water-soluble pillar[6]arene WP6 containing 12 imidazolium groups, silver nanoparticles were successfully prepared and investigated in detail by ultraviolet visible spectroscopy, X-ray diffraction, and transmission electron microscopy. Excitingly, these pillar[6]arene stabilized silver nanoparticles were demonstrated to function as a colorimetric sensor to selectively probe glutamic acid in water.     

Sieving properties of end group‐halogenated Pluronic polymer matrix in DNA separation under nondenaturing CE analysis

CE‐SSCP analysis is a well‐established DNA separation method that is based on variations in mobility caused by sequence‐induced differences in the conformation of single‐stranded DNA. The resolution of CE‐SSCP analysis was improved by using a Pluronic polymer matrix, and it has been successfully applied in various genetic analyses. Because the Pluronic polymer forms a micellar cubic structure in the capillary, it provides a stable internal structure for high‐resolution CE‐SSCP analysis. We hypothesized that formation of micellar cubic structure is influenced by the end hydroxyl group of the Pluronic polymer, which affords structural stability through hydrogen bonding. To test this hypothesis, the hydroxyl group was halogenated to eliminate the hydrogen bonding without disturbing the polarity of polymer matrix. CE‐SSCP resolution of two DNA fragments with a single base difference was significantly worse in the halogenated polymer matrices due to band broadening. The viscoelastic properties of control (which has hydroxyl group), chlorinated, and brominated F108 solution upon heating were also investigated by rheological experiments, and we found that gelation was significantly associated with resolution. In this series of experiments, the effect of the hydroxyl group in Pluronic polymer matrix on separation resolution of CE‐SSCP analysis was demonstrated.     

Topography and field effects in the inner side of microvia hole using ToF‐SIMS

We have developed a simple and powerful method, which is called ‘angled sample holder method’, to characterize a topographic structured sample such as microsized via hole of ball grid array using time‐of‐flight SIMS. The diameter of via holes was 100 µm and the depth was 70 µm. To remove the shaded area by incidence primary ion beam and to extract secondary ions from the bottom of a via hole, several types of angled sample holders with compensation steering plate were applied on the basis of simulation results using SIMION code. And the analyses using angled sample holder method enabled us to characterize the bottom and side wall of a via hole in clear. Copyright © 2014 John Wiley & Sons, Ltd.     

A multiplex single nucleotide polymorphism genotyping method using ligase‐based mismatch discrimination and CE‐SSCP

Accuracy, simplicity, and cost‐effectiveness are the most important criteria for a genotyping method for SNPs compatible with clinical use. One method developed for SNP genotyping, ligase‐based discrimination, is considered the simplest for clinical diagnosis. However, multiplex assays using this method are limited by the detection method. Although CE has been introduced as an alternative to error prone microarray‐based detection, the design process and multiplex assay procedure are complicated because of the DNA size‐dependent separation principle. In this study, we developed a simple and accurate multiplex genotyping method using reaction condition‐optimized ligation and high‐resolution CE‐based SSCP. With this high‐resolution CE‐SSCP system, we are able to use similar‐sized probes, thereby eliminating the complex probe design step and simplifying the optimization process. We found that this method could accurately discriminate single‐base mismatches in SNPs of the tp53 gene, used as targets for multiplex detection.     

A simple fabrication method for tapered capillary tip and its applications in high‐speed CE and ESI‐MS

Fabrication of capillaries with tapered tips is an important technique that is required in many analytical chemistry areas, such as ESI‐MS, CE, electrochemical analysis, and microinjection. This paper describes a simple and effective grinding‐based fabrication method for capillaries with tapered tips. A novel grinding mode utilizing the combination of rotation and precession of an elastic capillary was developed, which significantly improved the controllability to the grinding process as well as the capillary tip shape. The capillary was fabricated by fixing it in an electric drill installed perpendicularly, and grind the capillary tip rotated around its own axis as well as the drill axis on sandpapers. Compared with conventional fabrication techniques for capillary tips, the present method is easy to control the capillary tip shape in routine laboratories without the requirement of expensive equipments or poisonous reagent (e.g. hydrofluoric acid (HF) solution). Various capillaries with different tip diameters and tip taper angles could be fabricated using the present method with good controllability and reproducibility. These capillaries were applied in high‐speed CE and ESI‐MS analysis to demonstrate the feasibility and potential of this fabrication method.