激光光镊技术在单细胞、单分子科学中的应用研究

首先阐明了单细胞、单分子分析与研究的学科价值和社会意义：强调了激光光镊技术的出现对促进单分子、单细胞科学的发展的实际贡献;介绍了光镊的物理原理和工作特点;着重总结了激光光镊技术在单分子、单细胞领域的具体应用情况,并结合详细的研究工作,对这一技术的开发完善和应用发展给出了一些评述和建议：阐述了光镊技术在单细胞、单分子研究中的潜在地位和巨大的发展前景。     

Cell trapping, DNA extraction and Molecular Combing in a microfluidic device for high throughput genetic analysis of human DNA

We report on an integrated microfluidic device for cell trapping, DNA extraction and Molecular Combing which can be used for genetic analysis of human DNA. Our results show that it is possible to isolate and linearize the genetic material of a few cells without introducing any manipulation step of DNA molecules, thus increasing dramatically the size of the events that can be studied on the genome. Such extraction strategy is simple and fast, providing a new possibility of high throughput single-cell DNA analysis which should be applicable to cancer research, genome mapping, and genotoxicity studies.     

DNA单分子的纳米定位切割与拾取研究

报道了一种对DNA单分子进行精细的纳米定位切割和拾取的技术。首先用分子梳技术将DNA拉直固定在经3-氨基丙基三乙氧基硅烷修饰的云母基底上,然后通过精细控制原子力显微镜针尖与DNA样品之间的作用力,实现了对DNA链的定位切割和拾取。这种方法不仅可制备应用于临床遗传诊断和致病基因的定位等多种的微小DNA探针．而且有望发展为一种基于纳米操纵技术的DNA有序化测序策略。     

A practical metric for soft error vulnerability analysis of combinational circuits

Besides the advantages brought by technology scaling, soft errors have emerged as an important reliability challenge for nanoscale combinational circuits. Hence, it is important for vulnerability analysis of digital circuits due to soft errors to take advantage of practical metrics to achieve cost-effective and reliable designs. In this paper, a new metric called Triple Constraint Satisfaction probability (TCS) is proposed to evaluate the soft error vulnerability of combinational circuits. TCS is based on a concept called Probabilistic Vulnerability Window (PVW) which is an inference of the necessary conditions for soft-error occurrence in the circuit. We propose a computation model to calculate the PVW’s for all circuit gate outputs. In order to show the efficiency of the proposed metric, TCS is used in the vulnerability ranking of the circuit gates as the basic step of the vulnerability reduction techniques. The experimental results show that TCS provides a distribution of soft error vulnerability similar to that obtained with fault injections performed with HSPICE or with an event driven simulator while it is more than three orders of magnitude faster. Also, the results show that using the proposed metric in the well-known filter insertion technique achieves up to 19.4%, 34.1%, and 55% in soft error vulnerability reduction of benchmark circuits with the cost of increasing the area overhead by 5%, 10%, and 20%, respectively.     

Study of indium droplets formation on the InxGa1−xN films by single crystal x-ray diffraction

Indium droplet formation during the epitaxial growth of In_xGa_1−xN films is a serious problem for achieving high quality films with high indium mole fraction. In this paper, we studied the formation of indium droplets on the In_xGa_1−xN films grown by metalorganic chemical vapor deposition (MOCVD) using single crystal x-ray diffraction. It is found that the indium (101) peak in the x-ray diffraction spectra can be utilized as a quantitative measure to determine the amounts of indium droplets on the film. It is shown by monitoring the indium diffraction peak that the density of indium droplets increases at lower growth temperature. To suppress these indium droplets, a modulation growth technique is used. Indium droplet formation in the modulation growth is investigated and it is revealed in our study that the indium droplets problem has been partially relieved by the modulation growth technique.     

C_(60)对DNA光动力学作用的FT-Raman光谱研究

采用傅里叶变换激光Ｒａｍａｎ光谱术从分子水平研究了富勒烯Ｃ６０对小牛胸腺ＤＮＡ的光动力学作用。结果表明光激发Ｃ６０对ＤＮＡ各组分基团均有不同程度的损伤，其中ＤＮＡ的空间构像破坏显著，腺嘌呤次之，骨架磷酸基团、脱氧核糖、嘧啶环等也遭到破坏并导致ＤＮＡ链断裂。这种结果并非由于Ｃ６０与ＤＮＡ分子之间直接的电子相互作用，而是通过单线态氧（１Ｏ２）或·ＯＨ，Ｏ２·－等多自由基作用所致     

结构分析技术在行波管可靠性评估中的应用

结构分析是一种重要的元器件可靠性评估方法,可以评估元器件内是否存在潜在的缺陷。行波管结构分析可以为行波管固有质量和固有可靠性的判断提供重要依据。探讨了结构分析技术在行波管可靠性评估中的应用,给出了行波管结构分析的一般试验流程、一般技术流程、分解原则以及典型的结构单元分解,并提出了行波管结构分析中应注意的几个问题。     

LIBS检测钢液Mn元素的实验条件优化

激光诱导击穿光谱(LIBS)技术作为一种快速分析元素组成技术,在冶金分析领域具有广阔的应用前景.实验参数对LIBS检测钢液元素有较大影响,为提高LIBS技术检测的灵敏度需要对系统关键参数激光脉冲能量和ICCD门延时进行优化.本实验以钢液中Mn元素的分析线为研究对象,在激光等离子体满足局部热平衡和光学薄条件下,用Mn元素...     

自相关分析在漏磁信号检测中的应用

漏磁检测（MFL）是目前常用的一种无损检测（NDE）方法,针对漏磁检测中漏磁信号微弱且噪声影响大的问题,提出采用自相关分析的方法处理漏磁信号,提高检测精度。通过理论推导验证自相关分析能够有效消除噪声干扰．并通过Matlab仿真证明其有效性。     

User emotion analysis in conflicting versus non-conflicting regions using online social networks

Society plays a vital role in maintaining the emotional health of an individual. People living in conflicting zones are emotionally degraded and often hold more negativity than the people living in serene areas. Nowadays, analyzing the emotions shared on social networking websites is an ongoing topic of research. In this paper, we presented the potential of user data available on the Facebook website in distinguishing the emotions of netizens in conflicting versus non-conflicting areas. We collected the Facebook posts of the users living in Kashmir (conflicting region) and Delhi (non-conflicting) with the help of two source accounts. Plutchik’s eight basic emotions, namely, fear, anger, sadness, joy, surprise, disgust, trust and anticipation have been used to determine the emotion state of a user. Based on two well-known lexicons, namely, EmoLex and Empath, a new dictionary called MoodBook is designed to determine the user emotions from their posts.After analyzing the data, we found that violence in the conflicting region has badly affected the psychology of the citizens as most of the people in Kashmir fall under three negative emotion categories, namely, fear, anger, and sadness, whereas the joy mood has been found more in the posts of Delhi-based users. Furthermore, a mood-vector is created for each user and used as an input to k-means clustering where it has been found that the citizens of two regions form separate groups based on their psychological state. The study of the difference between emotions expressed online by the citizens of conflicting and non-conflicting has not been seen in the literature till date.     

搅拌器配置对混波室独立采样点的影响

分别用数值计算(FDTD)和实验方法给出了不同频率不同搅拌器配置情况下混波室功率密度的相关函数,并计算了相应的独立采样数,数值计算结果与实验结果吻合,表明了算法的有效性.所得结论为混波室搅拌器的设计提供了依据.     

Quantitative mobility spectrum analysis (QMSA) for hall characterization of electrons and holes in anisotropic bands

An extension of the quantitative mobility spectrum analysis (QMSA) procedure, which determines free electron and hole densities and mobilities from magnetic-field-dependent Hall and resistivity measurements, to materials exhibiting anisotropic conduction is presented. As test cases, the fully computer-automated procedure is used to analyze magnetotransport data from Bi thin films and Bi/CdTe superlattices. Using the results of the QMSA procedure, the thermoelectric properties of these films can be accurately modeled. As a second exmaple, an electron mobility anisotropy ratio of ≈4.5 is derived from the QMSA treatment of the Hall data for bulk Si samples.     

Qualification of plastic encapsulated microcircuits (PEM) for avionicsBased on ``Plastic Encapsulated Microcircuits (PEM) Qualification Testing'''', by J. A. Scalise, which appeared in the Proceedings of the 46th Electronic Components and Technology Conference, Orlando, FL, U.S.A., 28–31 May 1996, pp. 392–397. © 1996 IEEE.

Microcircuit package qualification testing is used to establish the reliability of integrated circuit processes and devices as they relate to part packaging. This paper presents the results of package qualification tests conducted on plastic encapsulated microcircuits (PEMs) and plastic discrete devices (diodes, transistors) used in avionics applications. Highly accelerated stress test (HAST) and temperature cycle (TC) test results, including part failure mechanisms and associated failure rates, are provided. A variety of plastic package styles and integrated circuit functions have been tested. Examples of package styles tested include small outline (SO), plastic leaded chip carrier (PLCC), thin small outline package (TSOP), plastic quad flat package (PQFP) and plastic dual-in-line (PDIP).Manufacturers' devices have been evaluated and various plastic compounds have been compared to determine which provide optimum reliability. The testing showed that package qualification performance of PEMs is affected by type of compound, passivation (including die coat) and die size. HAST failures are caused by moisture penetration of the package while temperature cycle failures result from coefficient of thermal expansion (CTE) mismatch effects.