Design of a 0.9 V 2.45 GHz Self-Testable and Reliability-Enhanced CMOS LNA

A self-testable and highly reliable low noise amplifier designed in 0.13 m CMOS technology is presented in this paper. This reliable LNA could be used to design the front-end of critical nodes in wireless local area networks to ensure data transmission. The LNA test, based on a built-in self test methodology, monitors its behavior. The test circuit is composed of one sensor and one biasing voltage sensor, and it offers high fault coverage. The high reliability is ensured by the use of redundancies. The LNA works under a 0.9 V supply voltage and the test chip has RF characteristics suitable for 802.11b/g applications. Parametric faults are injected and detected to demonstrate the efficiency of the BIST circuitry. Thanks to the switching on redundant blocks, performances are maintained and hence this proves the reliability of the methodology proposed.     

Even 2 × 2 Submatrices of a Random Zero-One Matrix

Consider an m×n zero-one matrix A. An s×t submatrix of A is said to be even if the sum of its entries is even. In this paper, we focus on the case m=n and s=t=2. The maximum number M(n) of even 2×2 submatrices of A is clearly and corresponds to the matrix A having, e.g., all ones (or zeros). A more interesting question, motivated by Turán numbers and Hadamard matrices, is that of the minimum number m(n) of such matrices. It has recently been shown that for some constant B. In this paper we show that if the matrix A=A_n is considered to be induced by an infinite zero one matrix obtained at random, then where E_n denotes the number of even 2×2 submatrices of A_n. Results such as these provide us with specific information about the tightness of the concentration of E_n around its expected value of Acknowledgments. The research of both authors was supported by NSF Grant DMS-0139291 and conducted at East Tennessee State University during the Summer of 2002, when Johnson was a student in Godboles Research Experiences for Undergraduates Program. The valuable suggestions of two anonymous referees are gratefully acknowledged.     

A modification over Sakoe and Chiba's dynamic time warping algorithm for isolated word recognition

A modification over Sakoe and Chiba's dynamic time warping algorithm for isolated word recognition is proposed. It is shown that this modified algorithm works better without any slope constraint. Also, this algorithm not only consumes less computation time but also improves the word recognition accuracy.     

A simple static circuit model for low-high junctions

A simple circuit model for low-high junctions is developed by using basic charge-control concepts. The model is valid in the low-level injection regime. The junction current is expressed as a function of the quasi-Fermi level separation in the space-charge region, and contains linear and non-linear terms. It is shown that the linearity of the junction depends on which of the two terms dominates at a given applied voltage. Calculated static V-J characteristics are given for an n-n⁺ device with donor concentration, N_D, on n-side as a parameter and that on n⁺-side equal to 10¹⁹ cm^?3. For N_D ≦ 10¹³cm^?3, the device is non-linear, for N_D = 10¹⁴ and 10¹⁵ cm^?3, the device is linear in low-level injection regime, and for $\text{N}{}_{\mathrm{D}}\text{≧ 10}{}^{16}\text{cm}{}^{\mathrm{?3}}$, the device is linear over a practically realizable range of applied voltages. The proposed model is expected to be useful in integrated circuit modeling.     

图像导引介入治疗中可视化3D的2D/3D图像数据分析

三维成像对许多医学过程(根本上是对患者的健康)来说,是非常关键的。本文探讨了三维成像方法的与众不同之处,以及作为一种不断发展创新的技术,临床医生们对它的需求和期待。     

Judd-Ofelt analysis of Tm and energy transfer studies between Tm and Er codoped in lithium tellurite network

Optical properties of Tm(3+) and Er(3+) and Tm(3+)+Er(3+) codoped tellurite glass have been studied using different wavelengths from a Ti-Sapphire laser as excitation source. The energy transfer from one rare earth to other on excitation with different wavelengths has been studied. The Judd-Ofelt theory has been used to calculate various optical parameters suitable for laser oscillation.     

An effective continuum approach for modeling non-equilibrium structural evolution of protein nanofiber networks

We quantify the formation and evolution of protein nanofibers using a new phase field modeling framework and compare the results to transmission electron microscopy measurements (TEM) and time-dependent growth measurements given in the literature. The modeling framework employs a set of effective continuum equations combined with underlying nanoscale forces and chemical potential relations governing protein nanofiber formation in solution. Calculations based on the theoretical framework are implemented numerically using a nonlinear finite element phase field modeling approach that couples homogenized protein molecular structure via a vector order parameter with chemical potential relations that describe interactions between the nanofibers and the surrounding solution. Homogenized, anisotropic molecular and chemical flux relations are found to be critical in obtaining nanofiber growth from seed particles or a random monomer bath. In addition, the model predicts both sigmoidal and first-order growth kinetics for protein nanofibers for unseeded and seeded models, respectively. These simulations include quantitative predictions on time scales of typical protein self-assembly behavior which qualitatively match TEM measurements of the RADA16-I protein and growth rate measurements for amyloid nanofibers from the literature. For comparisons with experiments, the numerical model performs multiple nanofiber protein evolution simulations with a characteristic length scale of ～2.4 nm and characteristic time scale of ～9.1 h. These results provide a new modeling tool that couples underlying monomer structure with self-assembling nanofiber behavior that is compatible with various external loadings and chemical environments.     

Well-defined air-stable palladium HASPO complexes for efficient Kumada-Corriu cross-couplings of (hetero)aryl or alkenyl tosylates

Palladium complexes of representative heteroatom-substituted secondary phosphine oxide (HASPO) preligands were synthesized and fully characterized, including X-ray crystal structure analysis. Importantly, these well-defined complexes served as highly efficient catalysts for Kumada-Corriu cross-coupling reactions of aryl, alkenyl, and even heteroaryl tosylates. Particularly, an air-stable catalyst derived from inexpensive PinP(O)H displayed a remarkably high catalytic efficacy, which resulted in cross-couplings at low catalyst loadings under exceedingly mild reaction conditions with ample scope.     

Highly selective SERS probe for Hg(II) detection using tryptophan-protected popcorn shaped gold nanoparticles

Contamination of the environment with toxic Hg(II) is becoming a huge concern throughout the world now. Driven by the need, this communication reports for the first time a tryptophan protected popcorn shaped gold nanomaterials based SERS probe for rapid, easy and highly selective recognition of Hg(II) ions in the 5 ppb level from aqueous solution, with high sensitivity and selectivity over competing analytes. We demonstrate that our SERS assay is capable of measuring the amount of Hg(II) in alkaline battery.     

Selective detection of mercury (II) ion using nonlinear optical properties of gold nanoparticles

Contamination of the environment with heavy metal ions has been an important concern throughout the world for decades. Driven by the need to detect trace amounts of mercury in environmental samples, this article demonstrates for the first time that nonlinear optical (NLO) properties of MPA-HCys-PDCA-modified gold nanoparticles can be used for rapid, easy and reliable screening of Hg(II) ions in aqueous solution, with high sensitivity (5 ppb) and selectivity over competing analytes. The hyper Rayleigh scattering (HRS) intensity increases 10 times after the addition of 20 ppm Hg(2+) ions to modified gold nanoparticle solution. The mechanism for HRS intensity change has been discussed in detail using particle size-dependent NLO properties as well as a two-state model. Our results show that the HRS assay for monitoring Hg(II) ions using MPA-HCys-PDCA-modified gold nanoparticles has excellent selectivity over alkali, alkaline earth (Li(+), Na(+), K(+), Mg(2+), Ca(2+)), and transition heavy metal ions (Pb(2+), Pb(+), Mn(2+), Fe(2+), Cu(2+), Ni(2+), Zn(2+), Cd(2+)).