Stellar classification (Total 454034 Papers Found)

Massive MIMO systems are well-suited for mm-Wave communications, as large arrays can be built with reasonable form factors, and the high array gains enable reasonable coverage even for outdoor communications. One of the main obstacles for using such systems in frequency-division duplex mode, namely, the high overhead for the feedback of channel state information (CSI) to the transmitter, can be mitigated by the recently proposed joint spatial division and multiplexing (JSDM) algorithm. In this p ...
CLIMA programs reveal the presence of energetic gravity currents that are formed over the western continental slope of the Ross Sea when High Salinity Shelf Water exits the shelf through Drygalski Trough. Joides Trough, immediately to the east, offers an additional escape route for less saline Shelf Water, while the Glomar Challenger Trough still farther east is a major pathway for export of the once supercooled low-salinity Ice Shelf Water that forms under the Ross Ice Shelf. The Drygalski Trou ...
The data incorporated in the HITRAN database for NH3 are analyzed using a comprehensive and consistent set of quantum numbers, empirical lower energy levels and the BYTe variationally calculated line list as reference points. Labelings are checked to ensure that they obey both the usual selection rules and the HITRAN labeling formalisms; the problems identified are corrected where possible. Further assignments are brought into question by combination difference (CD) checking of implied upper ene ...
Spectral expansions are alternative representations of logic functions/signals in which the information are redistributed and presented differently in terms of spectral coefficients. The use of spectral representations often allows certain operations or analysis to be performed more efficiently on the data. In this paper, spectral expansions for ternary functions based on new fastest linearly independent arithmetic transforms are presented and discussed. The new transforms are generalizations of ...
The development of displacement-based approaches to assessment and design has created the need for reliable displacement response spectra for a wide range of response periods and damping ratios. The displacement spectra obtained from conversion of the acceleration spectra in most codes are unrealistic in both shape and amplitude. Recent work has led to the development of simple procedures to construct displacement response spectra for specific design earthquake scenarios. In this paper, such an ...
The basic optical properties and optical constants of the polystyrene doped with methylene blue (mb) and methyl orange (mo) with thickness in the range (0.04-0.05) mm have been investigated by means of transmittance and reflectance spectra, were measured in the wavelength range (300-900) nm. The optical band gap Eg was determined and the optical absorption spectra show that the absorption mechanism is an indirect allowed transition, it has been found that optical energy gap Eg decreases with the ...
Radio astronomical observations of highly Doppler shifted spectral lines of neutral hydrogen and the hydroxyl molecule must often be made at frequencies allocated to pulsed air surveillance radar in the 1215-1350 MHz frequency range. The Green Bank telescope (GBT) and many other observatories must deal with these terrestrial signals. Even when strong radar fixed clutter echoes are removed, there are still weaker aircraft echoes present which can corrupt the data. We present an algorithm which im ...
Trimers of light harvesting complex II from Arabidopsis thaliana were studied by femtosecond fluorescence upconversion. The average lifetime of the carotenoid S2 state was 57 fs for wild type trimers and 70 fs for trimers from a mutant plant with a distinctly different carotenoid composition. We estimate that 56% of the energy transferred from carotenoids to chlorophylls proceeds via the carotenoid S2 state in the wild type and 46% in the mutant. By comparison with the fluorescence excitation sp ...
Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S, and COSMOS fields, it is possible to sample the 8–500 μm spectral energy distributions (SEDs) of galaxies with at least 7–10 bands. Extending to the UV, optical, and near-infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selec ...
Gallic acid and its derivatives are widely present in the plant kingdom and are known to display antioxidant activity by the ability to counteract the damaging effects of free radicals in tissues and thus are believed to protect against cancer, arteriosclerosis, heart disease, and several other diseases. Hence, the present work describes the isolation of gallic acid derivatives from the ethyl acetate fraction of leaves of T. bangwensis. The structures of three phenolic acids of gallic acid deriv ...
Hematoporphyrin monomethyl ether (HMME) that is the second generation photosensitizers is a new and promising porphyrin related photosensitizer for photodynamic therapy and diagnosis in certain tumor. The binding of HMME to bovine serum albumin (BSA) in aqueous solution was studied using fluorescence spectra and absorption spectra. It was shown that HMME has a powerful ability to quench the BSA fluorescence by a non-radiative energy transfer mechanism. The binding constants, Kq, at 303 K and 310 ...
In this letter we study a new class of inflation models which generalize the Dirac-Born-Infeld (DBI) action with the addition of a nonminimal kinetic coupling (NKC) term. We dubbed this model as the new DBI inflation model. The NKC term does not bring new dynamical degree of freedom, so the equations of motion remain of second order. However, with such a coupling, the action is no longer linear with respect to the Einstein curvature term (R or G), which leads to a correction term of k in the per ...
This is a review article of our work on hysteresis, avalanches, and criticality. We provide an extensive introduction to scaling and renormalization–group ideas, and discuss analytical and numerical results for size distributions, correlation functions, magnetization, avalanche durations and average avalanche shapes, and power spectra. We focus here on applications to magnetic Barkhausen noise, and briefly discuss non-magnetic systems with hysteresis and avalanches. ...
Fruit of Malus domestica is the most well-known and utilized fruit. The history of apple cultivation covers about 50 centuries. The chemical composition of apples is widely studied because of their beneficial effect on the human body. Apples contain large amounts of both simple and complex carbohydrates [1]. Bioflavonoids, phenolic acids, vitamins, and trace elements are responsible for the principal biological activities [1, 2]. Apple peel was reported to have a high content of triterpene acids ...
THE signal strength and Doppler frequency spectra of v.h.f. backscatter radar echoes from the equatorial electrojet are being recorded at Thumba near Trivandrum (dip ∼ 1 °S). The v.h.f. radar operates on 54.95 MHz, with identical arrays of Yagi antennae for transmission and reception; the beam axis is orientated either vertically or obliquely at 30° to the vertical. Analysis of the radar backscatter signals and the magnetograms at Thumba has revealed that quasi-periodic fluctuations of the e ...
We analysed new simultaneous Suzaku and Swift data of the broad-line Seyfert 1 (BLS1) galaxy CBS 126. A clear Fe emission line and a strong soft excess are present in the source spectra. We fit the spectra with a relativistic reflection model and find that the model tends to fit the data with a high iron abundance possibly due to the large soft excess present. By checking the difference and the rms spectra, we find that there is likely an absorption edge at ∼0.89 keV, which might be caused by ...
Late-time BV RIJHK photometry of the peculiar Type Ic SN 2002ap, taken between 2002 June 12 and 2003 August 29 with the MAGNUM telescope, is presented. The light curve decline rate is derived in each band and the color evolution is studied through comparison with nebular spectra and with SN 1998bw. Using the photometry, the OIR bolometric light curve is built, extending from before light maximum to day 580 after explosion. The light curve has a late-time shape strikingly similar to that of the h ...
Computational and spectroscopic techniques have been combined to probe local protein structure. Experimental resonance Raman spectra were obtained for small fragments of the 29 amino acid glucose regulating protein glucagon. The Raman spectra for these fragments were also simulated computationally and were used to aid in the interpretation of the experimental spectra. Glucagon was then probed with experimental resonance Raman at a wavelength of 224 nm. Both the experimental and computational dat ...
T he metabolic studies described in the previous article represent a relatively straightforward application of NMR spectroscopy. The positions of the various resonances and their heights allow one to determine the presence and amount of metabolic intermediates and products and, in turn, the specific metabolic pathways involved. These tracer studies with stableisotope labels are thus directly analogous to studies with radiolabels such as carbon14. But NMR spectra contain a wealth of additional in ...
Published data offer numerous examples of the lipophilic modification of various lowand high-molecular-mass compounds. Synthesized and characterized compounds include the lipid derivatives of antitumor preparations such as 5fluorottracil conjugated with cholesterol [1], 5-fluoro-2'-deoxyuridine conjugated with palmitic acid [2], methotrexate conjugated with phosphatidylethanolamine [3], 1-13-Darabinofuranosylcytosine conjugated with cholesteryloxycarbonylglycine [4, 5], 1,2-dipalmitoylphosphatid ...
Complementary XAFS measurements (LURE and NSLS) of Sel,Te, glasses have been canied out on both the Se and Te Kedges at low and room temperatures. Using a multi-shell best fit analysis procedure, we have reconstructed the Se and Te local environment: (i)first shell intrachain nearest neighbors (Se-Sel, Se-Tel, Te-Se~,and Te-Tel); (ii) second shell intrachain (Se-Sez and Se-Tez) and interchain next nearest neighbors (SeoSe3 single scattering in the chains Se-Sel-Se3 and Se-Tel-Se3). For the f i t ...
-Diffuse Reflectance Fourier Transform Infrared spectroscopy was used to monitor both molecular interactions and concentrations of volatile organic chemicals adsorbed on a commercial montmorillonite. Chemicals tested included propanoic acid, hexanal, heptanal, trimethylamine, dimethylsulfide and dimethyldisulfide. Diffuse Reflectance Fourier Transform Infrared spectroscopy had several advantages over other infrared techniques including ease of sample preparation, greater numbers of useful bands ...
[1] In the paper ‘‘Effects of hydration on the elastic properties of olivine’’ by S. D. Jacobsen et al. (Geophysical Research Letters, 35, L14303, doi:10.1029/2008GL034398, 2008), the sample of hydrous olivine labeled hy-Fo97 with (001) orientation in the bottom plot of original Figure 1b has been subsequently identified by Raman spectroscopy as OH-chondrodite, (Mg,Fe)5Si2O8(OH)2 [e.g., Lin et al., 1999]. The OH-chondrodite co-existed with hydrous forsterite in the synthesis run, and all ...
A complete sample of 659 field galaxies with 17.0<U≤21.1, each with U-B-VR-I7500-I8600 photometry, has been selected from a deep field survey which covers 0.83 deg2 along six lines of sight (Hall et al. 1996a). Each galaxy’s spectral type and redshift has been estimated using a multicolor photometric technique (Liu & Green 1998). Total number counts of the galaxies in the U-band give a count slope d(logN)/dM = 0.55 ± 0.05, consistent with previous studies. The 545 galaxies in the sample ...
The ground state, singlet! singlet and singlet! triplet vertical excited states of styrene have been studied by using the symmetry adapted cluster-configuration interaction (SAC-CI) method with aug-cc-pVDZ basis sets supplemented with molecule-centered Rydberg functions. The characteristic structures of the bands observed in the vacuum ultraviolet (VUV) and electron energy loss (EEL) spectra have been theoretically clarified by calculating the excitation energies, oscillator strengths, and secon ...
The absolute absorption spectra of low-loss optical waveguides, together with their intrinsic and extrinsic scatterings, were measured in the near infrared. Photothermal deflection spectroscopy was used to measure the full absorption spectra of a series of fluorinated cross-linked polymers. Assignment of —CH3, —CH2—, and —OH overtones as well as of combinations of overtones were made by use of the theory of anharmonic vibrations based on a Morse potential for local modes. Details of the ...
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für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namensnennung 4.0 Lizenz. Determination of Vibrational Resonance Parameters in the Spectra of Polyatomic ...
We examine the spectral function of the single electron Green function at finite temperatures for the Tomonaga-Luttinger model which consists of the mutual interaction with only the forward scattering. The spectral weight, which is calculated as a function of the frequency with the fixed wave number, shows that several peaks originating in the excitation spectra of charge and spin fluctuations vary into a single peak by the increase of temperature. ...
A series of new Schiff bases derived from 2-aminopyridenes and various aromatic aldehydes have been synthesized and thoroughly investigated by 1H and 13C NMR spectroscopy. The imines were found to exist as only a single E-isomer at ambient temperature. Interestingly, 1Hand 13C-NMR chemical shifts of the (CH=N) amino group are affected by the type of substituent group (X) on the aryl ring. Furthermore UV and IR Spectra of some of the title compounds are also reported. ...
Planetary nebulae (PNe) can be used to trace intermediate and old stellar populations in galaxies and the intracluster medium out to approximately 20 Mpc. PNe can be easily identified with narrow-band surveys, and their chemical abundances and radial velocities can be measured with multi-slit or multi-fiber spectrographs. We briefly review what has been accomplished to date, and include tables (with references) that summarize the observations of PNe in 42 galaxies and in the intracluster media o ...
Tandem mass spectrometric techniques in combination with high-level quantum chemical calculations have been employed to study the coordination chemistry of manganese– and oxomanganese–salen complexes in the gas phase. Electrospray ionization was used to transfer the ionic complexes from solution to the gas phase. The formation of fiveversus six-coordinate manganese(III) species was subsequently probed by ion–molecule reactions with neutral ligands, e.g. acetonitrile, pyridine, alcohols, et ...
Polar ring galaxies are flattened stellar systems with an extended ring of gas and stars rotating in a plane almost perpendicular to the central galaxy. We show that their formation can occur naturally in a hierarchical universe where most low mass galaxies are assembled through the accretion of cold gas infalling along megaparsec scale filamentary structures. Within a large cosmological hydrodynamical simulation we find a system that closely resembles the classic polar ring galaxy NGC 4650A. Ho ...
The first study of the local interstellar medium (LISM) toward Puppis-Vela (l = 245 to 275, b = −15 to +5, d < 200 pc) is presented in this paper. A study of the locations, sizes, and physical characteristics of local interstellar gas, i.e. “astronephography,” is included, and relies upon the improved distance measurements provided by Hipparcos parallax measurements. All spectra of more distant sight lines contain absorption features due to intervening local gas, and more distant struct ...
Recently we have studied the Bloch effective Hamiltonian approach to bound states in 2+1 dimensional gauge theories. Numerical calculations were carried out to investigate the vanishing energy denominator problem. In this work we study similarity renormalization approach to the same problem. By performing analytical calculations with a step function form for the similarity factor, we show that in addition to curing the vanishing energy denominator problem, similarity approach generates linear co ...
Ideal hydrodynamic simulations are performed to compute the evolution with collision energy of hadron spectra and elliptic flow between AGS and LHC energies. We argue that viscous effects should decrease with increasing energy, improving the applicability of ideal fluid dynamics at higher energies. We show that the increasing radial flow at higher energies pushes the elliptic flow to larger transverse momenta, leading to a peaking and subsequent decrease of the elliptic flow at fixed pT with inc ...
The objective of this project was to use sucrose as a partial substitute for melamine in the synthesis of sucrose–melamine-formaldehyde (SMF) resin. The SMF was synthesized in a base condition. The wet bonding strength, shelf life, and formaldehyde emission of the SMF resin were determined. Fourier transform infrared spectroscopy (FT-IR) and mass spectroscopy (MS) were employed to analyze the chemical structure of the SMF resin. The shelf life of SMF resin increased as the sucrose content incr ...
The sampling of spectrally sparse high-bandwidth signals below the Nyquist rate is of importance in many applications. In order to keep the front-end analog-to-digital converter sampling rate low, there has been a lot of recent interest in the literature to develop efficient and practical architectures for low-rate sampling and recovery of spectrally sparse signals. Our main contribution is a simple, implementation-friendly front-end sampling-architecture and a computationally efficient back-end ...
Various semiconductor devices with an S-shaped current-voltage characteristic exhibit complex self-organized spatio-temporal spiking where a current lament nu-cleates and vanishes immediately afterwards. We analyze a simple generic model for this type of behaviour, and nd a variety of scenarios where stationary laments , homogeneous relaxation oscillations, periodic spiking and chaotic spiking (via period-doubling or intermittency) occur, including bistability between spiking and a stable lament ...
We present that the radio emission with flat spectrum in X-ray binaries comes from the synchrotron emission of relativistic electrons in the high energy tail of hot electrons in continuous conical jet. The jet is assumed to be produced by the advection-dominated accretion flow (ADAF) and maintains ion and electron temperatures constant in the case of adiabatic steady conical expansion. The flat spectrum is result of self-absorbed synchrotron emission by relativistic thermal electrons. We find th ...
Introduction: 3D MR spectroscopic imaging (3D MRSI) is a powerful tool for diagnosis of brain tumors but long acquisition times in the order of 20-30 minutes causes patient discomfort and motion artifacts. In recent years, several pulse sequence developments proposing different trajectories in k-space such as elliptical sampling (sampling the central elliptical portion of k-space) or echo-planar imaging have been proposed in the literature to reduce the scan time. Alternatively, sensitivity enco ...
By using LEKIDs the prospect rises to multi-pixel arrays with an extremely small footprint. Moreover, these arrays have the advantage of frequency-division multiplex readout method (FDM). However, the increase of packing density of LEKIDs leads to an increase of crosstalk between adjacent pixels and complicates the readout process significantly. In this paper, we present a newly developed LEKID structure with reduced crosstalk and present their improved performance in terms of equally spaced res ...
Silica based waveguides on Si fabricated by flame hydrolysis deposition were doped with erbium ions using an aerosol doping technique, and co-doped with GeO2, P2O5 and B2O3. Erbium doping levels in the films were dependent on the nebulized solution concentration and delivery rate of the aerosol to the torch. The erbium solution concentration was varied from 4 to 8 wt%. The refractive index was measured by a prism coupler at 633 nm. FTIR absorption spectra and XRD profiles were made to check the ...
The use of lifetime measurements for the specification of transition probabilities along isoelectronic sequences is hindered by the fact that virtually no branching fraction measurements exist for multiply charged ions. Part of the reason for this lies in the lack of calibration standards for intensity as a function of wavelength in the ultraviolet region. It has been shown that transitions of the form ns2np2–ns2npn′s in Si I and Ge I are virtually free of configuration interaction, hence th ...
Here we study various covering spectra for complete noncompact length spaces with universal covers (including Riemannian manifolds and the pointed Gromov Hausdorff limits of Riemannian manifolds with lower bounds on their Ricci curvature). We relate the covering spectrum to the (marked) shift spectrum of such a space. We define the slipping group generated by elements of the fundamental group whose translative lengths are 0. We introduce a rescaled length, the rescaled covering spectrum and the ...
The low dispersion STIS spectrophotometric flux calibration must account for all instrumental non-linearities and all changes in sensitivity with time and temperature. An empirical algorithm for CCD Charge Transfer Efficiency (CTE) is presented along with the wavelength dependent sensitivity changes. Precise STIS spectrophotometry includes corrections for CTE losses as large as 20% for faint signals and low sky, for MAMA non-linearities of ∼ 2%, and for loss in system throughput that currently ...
Although many well controlled experiments have been cotlducted to measure the static properties of systems near criticali[), few experiments have explored the transport properties in systems driven far away from equilibrium as a phase transition occurs. The cryogenic design of an experiment to study the dynamic aspect of critical phenomena is reported here. Measurements of the thermal gradient across the superfluid (}ie II) normal fluid (He 1) interface in helium under microgravity conditions wi ...
The research of abnormal phenomena in the spectra of the particles effective mass in nucleon-nucleon and nucleon-nucleus interactions is of great interest. To the present time in scientific centers of CIS, France, Germany, USA, Japan and etc. a lot of studies with the purpose of baryon structure discovering in the two-nucleon system have been executed. Obtained results, however, are not convincing because of the presence of both numerous indications on dinucleon resonances existence in the wide ...
The structure of acceptor–hydrogen complexes is a subject of fundamental and technological interest. To probe the interactions between hydrogen, the acceptor, and the surrounding host atoms, hydrostatic pressure may be applied over a wide range. Using infrared spectroscopy at liquid-helium temperatures, we have observed carbon and carbon– hydrogen local vibrational mode (LVMs) in InP at hydrostatic pressures as high as 5.5GPa. For pressures beyond 4.5GPa, the carbon–hydrogen mode was not o ...
We consider a classical model of matter–radiation interaction, in which the matter is represented by a system of infinitely many dipoles on a one– dimensional lattice, and the system is dealt with in the so–called dipole (i.e. linearized) approximation. We prove that there exist normal–mode solutions of the complete system, so that in particular the dipoles, though performing accelerated motions, do not radiate energy away. This comes about in virtue of an exact compensation which we pro ...
We observed GX 9+1 on 1996 Feb 29, Apr 21, May 29, and 1997 Feb 10 and Mar 9, and GX 9+9 on 1996 Aug 12, Oct 16, and Oct 30 with the RXTE satellite. We obtained a total of 23.3 ksec (GX 9+1) and 15.2 ksec (GX9+9) of data. The X-ray hardness-intensity diagrams (HIDs) were made using the Standard 2 data. Due to gain changes the GX 9+1 HID for the 1996 Feb 29 observation can not be directly compared with those of the other observations. The power density spectra were made using the 250μs time reso ...