First Order Sea Clutter Cross Section for HF Hybrid Sky-Surface Wave Radar

This paper presents a modified method to simulate the first order sea clutter cross section for high frequency (HF) hybrid sky-surface wave radar, based on the existent model applied in the bistatic HF surface wave radar. The modification focuses on the derivation of Bragg scattering frequency and the ionosphere dispersive impact on the clutter resolution cell. Meanwhile, an analytic expression to calculate the dispersive transfer function is derived on condition that the ionosphere is spherical stratified. Simulation results explicate the variance of the cross section after taking account of the influence triggered by the actual clutter resolution cell, and the spectral width of the first order sea clutter is defined so as to compare the difference. Eventually, experiment results are present to verify the rationality and validity of the proposed method

Semi-actively implemented non-linear damping for building isolation under seismic loadings

It is well-known that semi-active solution can achieve building isolation with much less energy requirements than active solutions. Also, it has been shown in previous studies that compared to linear damping, non-linear damping performs better for building isolation under sinusoidal ground motions. The present study is concerned with the extension of the application of the semi-actively implemented non-linear damping to building isolation under seismic loadings. A two-degree-of-freedom (2-DOF) scaled building model is used for simulation studies. Experimental tests on a physical building model have been used to validate the effectiveness of the 2-DOF scaled building model in representing the behaviors of a physical building structure. The optimal design of the semi-actively implemented non-linear damping for building isolation under design seismic motions is then carried out using the 2-DOF scaled building model based on simulation studies. The results show that an optimal design of semi-actively implemented non-linear damping can improve the performance of building isolation under design seismic motions in terms of both absolute acceleration and inter-story drift

πΔΔ\pi \Delta\Delta coupling constant

We calculate the $\pi \Delta\Delta$ coupling $g_{\pi^0\Delta^{++}\Delta^{++}}$ using light cone QCD sum rule. Our result is $g_{\pi^0\Delta^{++}\Delta^{++}}=(11.8\pm 2.0)$.Comment: RevTex, 5 pages + 1 PS figur

The analysis of nonlinear systems in the frequency domain using Nonlinear Output Frequency Response Functions

The Nonlinear Output Frequency Response Functions (NOFRFs) are a concept which provides a new extension of the well-known concept of the Frequency Response Function (FRF) of linear systems to the nonlinear case. The present study introduces a NOFRFs based approach for the analysis of nonlinear systems in the frequency domain. It is well known that a nonlinear system can, under rather general conditions, be represented by a polynomial type Nonlinear Auto Regressive with eXogenous input (NARX) model. From the NARX model of a nonlinear system under study, the NOFRFs based approach for the frequency analysis of nonlinear systems involves solving a set of linear difference equations known as the Associated Linear Equations (ALEs) to determine the system nonlinear output responses and then the NOFRFs of the system up to an arbitrary order of nonlinearity of interests. The results enable a representation of the frequency domain characteristics of nonlinear systems by means of a series of Bode diagram like plots that can be used for nonlinear system frequency analyses for various purposes including, for example, condition monitoring, fault diagnosis, and nonlinear modal analysis

Superconductivity and single crystal growth of Ni0:05TaS2

Superconductivity was discovered in a Ni0:05TaS2 single crystal. A Ni0:05TaS2 single crystal was successfully grown via the NaCl/KCl flux method. The obtained lattice constant c of Ni0:05TaS2 is 1.1999 nm, which is significantly smaller than that of 2H-TaS2 (1.208 nm). Electrical resistivity and magnetization measurements reveal that the superconductivity transition temperature of Ni0:05TaS2 is enhanced from 0.8 K (2H-TaS2) to 3.9 K. The charge-density-wave transition of the matrix compound 2H-TaS2 is suppressed in Ni0:05TaS2. The success of Ni0:05TaS2 single crystal growth via a NaCl/KCl flux demonstrates that NaCl/KCl flux method will be a feasible method for single crystal growth of the layered transition metal dichalcogenides.Comment: 13pages, 6 figures, Published in SS

Hadronic Parity Violation and Inelastic Electron-Deuteron Scattering

We compute contributions to the parity-violating (PV) inelastic electron-deuteron scattering asymmetry arising from hadronic PV. While hadronic PV effects can be relatively important in PV threshold electro- disintegration, we find that they are highly suppressed at quasielastic kinematics. The interpretation of the PV quasielastic asymmetry is, thus, largely unaffected by hadronic PV.Comment: 27 pages, 13 figures, uses REVTeX and BibTe

Molecular cytogenetic aberrations in patients with multiple myeloma studied by interphase fluorescence in situ hybridization

Background: Multiple myeloma (MM) is an incurable hematological disorder characterized by the accumulation of malignant plasma cells within the bone marrow (BM). The clinical heterogeneity of MM is dictated by the cytogenetic aberrations present in the clonal plasma cells (PCs). Cytogenetic studies in MM are hampered by the hypoproliferative nature of plasma cells in MM. Therefore, fluorescence in situ hybridization (FISH) analysis combined with magnetic-activated cell sorting (MACS) is an attractive alternative for evaluation of numerical and structural chromosomal changes in MM. Methods: Interphase FISH studies with three different specific probes for the regions containing 13q14.3 (D13S319), 14q32 (IGHC/IGHV) and 1q12(CEP1 ) were performed in 48 MM patients. Interphase FISH studies with LSI IGH/CCND1, LSI IGH/FGFR3, and LSI IGH/MAF probes were used to detect t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23) in patients with 14q32 rearrangement. Results: Molecular cytogenetic aberrations were found in 40 (83.3%) of the 48 MM patients. 13 patients (27.1%) simultaneously had 13q deletion/monosomy 13 [del(13q14)], illegitimate IGH rearrangement and chromosome 1 abnormality. Del(13q14) was detected in 21 cases (43.7%), and illegitimate IGH rearrangements in 29 (60.4%) including 6 with t(11;14) and 5 with t(4;14). None of 9 patients with illegitimate IGH rearrangements and without t(11;14) or t(4;14) we detected had t(14;16) (q32;q23). 24 of the 48 MM patients (50%) had chromosome 1 abnormalities. Among 21 patients with del(13q14), 15 patients had Amp1q12;16 had IgH rearrangements. Whereas, among 27 cases without del(13q14), 8 had Amp1q12; 13 had IgH rearrangements. There was a strong association between del(13q14) and Amp1q12(c2 = 8.26, р < 0.01), and between del(13q14) and IgH rearrangement(c2 = 3.88, p < 0.05). Conclusion: 13q deletion/monosomy 13, IGH rearrangement and chromosome 1 abnormality are frequent in MM. They are not randomly distributed, but strongly interconnected. Interphase FISH technique combined with MACS using CD138-specific antibody is a highly sensitive technique at detecting molecular cytogenetic aberrations in MM.Обоснование: множественная миелома (MM) — неизлечимое гематологическое заболевание, характеризирующееся накоплением злокачественных плазматических клеток в костном мозге (КM). Клиническая гетерогенность MM определяется цитогенетическими аберрациями, присутствующими в клоне плазматических клеток (ПК). Цитогенетические исследования MM осложнены гипопролиферативными особенностями ПК. В связи с этим флуоресцентная гибридизация in situ (FISH) в комбинации с сортировкой клеток, активированных магнитными полями (MACS) представляется достойной альтернативой методам оценки точечных и структурных изменений хромосом при MM. Методы: интерфазные исследования методом FISH с использованием трех различных специфических зондов для участков, содержащих 13q14.3 (D13S319), 14q32 (IGHC/IGHV) и 1q12(CEP1), проводили у 48 больных с MM. Интерфазные исследования методом FISH с использованием зондов LSI IGH/CCND1, LSI IGH/FGFR3 и LSI IGH/MAF применяли для детекции t(11;14)(q13;q32), t(4;14)(p16;q32), и t(14;16)(q32;q23) у пациентов с перестройкой 14q32. Результаты: молекулярные цитогенетические аберрации выявляли у 40 (83,3%) из 48 больных с MM. У 13 пациентов (27,1%) одновременно определены 13q делеция/моносомия 13 [del(13q14)], аномальная перестройка IGH и аномалия хромосомы 1. Del(13q14) детектировали в 21 случае (43,7%), а аномальные перестройки IGH — в 29 (60,4%), в том числе у 6 пациентов с t(11;14) и 5 с t(4;14). Ни у одного из 9 больных с аномальными перестройками IGH и без t(11;14) или t(4;14) не выявляли транслокацию t(14;16) (q32;q23). У 24 из 48 пациентов с MM (50%) определяли аномалии хромосомы 1. В группе из 21 больных с del(13q14) в 15 случаях имелись перестройки IgH Amp1q12;16. В то же время из 27 случаев без del(13q14) у 8 содержались Amp1q12; в 13 случаях отмечали перестройки IgH. Выявлена взаимосвязь между del(13q14) и Amp1q12(χ2 = 8,26, p < 0,01) и между del(13q14) и перестройками IgH (χ2 = 3,88, p < 0,05). Выводы: 13q делецию/моносомию 13, перестройку IGH и аномалию хромосомы 1 часто отмечают при MM, причем их распределение не случайно и тесно взаимосвязано. Интерфазный анализ FISH в комбинации с MACS с использованием CD138-специфичных антител является высокочувствительным методом детекции молекулярных цитогенетических аберраций при MM

Wigner Crystals Phases in Bilayer Quantum Hall Systems

(This is a substantially shortened version of the original abstract:) The Wigner crystal phase diagram of the bilayer systems have been studied using variational methods. Five crystal phases are obtained. As the layer spacing increases, the system will undergo a sequence of phase transitions. A common feature of most bilayer Wigner crystals is that they have mixed (pseudo-spin) ferromagnetic and antiferromagnetic order.Comment: 19 figures. Figures will be provided upon request. Submitted in PRB in Nov 94

A Green's function approach to transmission of massless Dirac fermions in graphene through an array of random scatterers

We consider the transmission of massless Dirac fermions through an array of short range scatterers which are modeled as randomly positioned $\delta$- function like potentials along the x-axis. We particularly discuss the interplay between disorder-induced localization that is the hallmark of a non-relativistic system and two important properties of such massless Dirac fermions, namely, complete transmission at normal incidence and periodic dependence of transmission coefficient on the strength of the barrier that leads to a periodic resonant transmission. This leads to two different types of conductance behavior as a function of the system size at the resonant and the off-resonance strengths of the delta function potential. We explain this behavior of the conductance in terms of the transmission through a pair of such barriers using a Green's function based approach. The method helps to understand such disordered transport in terms of well known optical phenomena such as Fabry Perot resonances.Comment: 22 double spaced single column pages. 15 .eps figure