cssi/SciSciGPT-SciSciNet huggingface dataset:
Trap behavior in AlGaN/GaN HEMTs by post-gate-annealing

Trapping effects are investigated to examine the post-gate annealing effects on AlGaN/GaN high-mobility electron transistors (HEMTs) using pulsed I-V and transient measurements. In the unannealed devices, shallow traps are identified, which have an activation of 38 meV at a drain bias of 7 V. The time constant of these traps is determined to be -0.5 /spl mu/s. Devices annealed at 400 /spl deg/C for 10 minutes have a significantly smaller number of traps. However, a small number of traps with a longer time constant of 9.2 /spl mu/s are created or activated during post-gate annealing. 20-minute annealing at 400 /spl deg/C leads to the increase of the number of traps with emission time constants of 21.6 /spl mu/s and 1.25 ms. The breakdown voltage improvement by post-gate annealing is attributed to the removal or significant reduction of the shallow level traps.
Electronic states of semiconductor-metal-semiconductor quantum-well structures

Quantum-size effects are calculated in thin layered semiconductor-metal-semiconductor structures using an ideal free-electron model for the metal layer. The results suggest new quantum-well structures having device applications. Structures with sufficiently high-quality interfaces should exhibit effects such as negative differential resistance due to tunneling between allowed states. Similarly, optical detection by intersubband absorption may be possible. Ultrathin metal layers are predicted to behave as high-density dopant sheets.
Radiative Properties of Numerically Generated Fractal Soot Aggregates: The Importance of Configuration Averaging

The radiative properties of numerically generated fractal soot aggregates were studied using the numerically accurate generalized multisphere Mie-solution method. The fractal aggregates investigated in this study contain 10–600 primary particles of 30 nm in diameter. These fractal aggregates were numerically generated using a combination of the particle-cluster and cluster-cluster aggregation algorithms with fractal parameters representing flame-generated soot. Ten different realizations were obtained for a given aggregate size measured by the number of primary particles. The wavelength considered is 532 nm, and the corresponding size parameter of primary particle is 0.177. Attention is paid to the effect of different realizations of a fractal aggregate with identical fractal dimension, prefactor, primary particle diameter, and the number of primary particles on its orientation-averaged radiative properties. Most properties of practical interest exhibit relatively small variation with aggregate realization. However, other scattering properties, especially the vertical-horizontal differential scattering cross section, are very sensitive to the variation in geometrical configuration of primary particles. Orientationaveraged radiative properties of a single aggregate realization are not always sufficient to represent the properties of random-oriented ensemble of fractal aggregates. �DOI: 10.1115/1.4000245�
Control of pathogenic effector T-cell activities in situ by PD-L1 expression on respiratory inflammatory dendritic cells during respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) infection is a leading cause of severe lower respiratory tract illness in young infants, the elderly and immunocompromised individuals. We demonstrate here that the co-inhibitory molecule programmed cell death 1 (PD-1) is selectively upregulated on T cells within the respiratory tract during both murine and human RSV infection. Importantly, the interaction of PD-1 with its ligand PD-L1 is vital to restrict the pro-inflammatory activities of lung effector T cells in situ, thereby inhibiting the development of excessive pulmonary inflammation and injury during RSV infection. We further identify that PD-L1 expression on lung inflammatory dendritic cells is critical to suppress inflammatory T-cell activities, and an interferon–STAT1–IRF1 axis is responsible for increased PD-L1 expression on lung inflammatory dendritic cells. Our findings suggest a potentially critical role of PD-L1 and PD-1 interactions in the lung for controlling host inflammatory responses and disease progression in clinical RSV infection.
Catalytic amination of 5-iodouracil derivatives

Abstract Heterocyclic 5-amino uracil derivatives were prepared by catalytic amination of 1,3-dibenzyl-5-iodouracil using (CuOTf)2·PhH, 1,10-phenanthroline, dibenzylidene acetone, and Cs2CO3 as base in xylenes at 95°C. Imidazole and 2-amino thiazoline were problematic using the Cu catalyst, but were effectively coupled using Ni(COD)2, dppf, and NatOBu in toluene at 100°C. These are the first examples of catalytic amination with a uracil substrate.
Dry matter losses during hay production and storage of sweet sorghum used for methane production

Abstract Losses from production and storage of large round hay bales from sweet sorghum were measured. Dry matter losses from hay production were 55·3%. Storage losses were 18·1% and 10·1% for outdoor and indoor storage, respectively. It was concluded that hay storage of sweet sorghum used for anaerobic digestion is not a viable option.
Ultra-sensitive Electric-field Detector Enabled by Micro Antenna and Transparent Conductor (TC) Enhanced Electro-optic (EO) Structure

We propose a compact ultra-sensitive electric-field detector enabled by a T-shaped micro antenna and a transparent conductor enhanced GaAs electro-optic structure with a minimum detectable electric-field strength of 17?V/m*Hz-1/2and frequency response above 1GHz.
X-33 Hypersonic Boundary-Layer Transition

Boundary layer and aeroheating characteristics of several X-33 configurations have been experimentally examined in the Langley 20-Inch Mach 6 Air Tunnel. Global surface heat transfer distributions, surface streamline patterns, and shock shapes were measured on 0.013-scale models at Mach 6 in air. Parametric variations include angles-of-attack of 20-deg, 30-deg, and 40-deg; Reynolds numbers based on model length of 0.9 to 6.6 million; and body-flap deflections of 0, 10 and 20-deg. The effects of discrete and distributed roughness elements on boundary layer transition, which included trip height, size, location, and distribution, both on and off the windward centerline, were investigated. The discrete roughness results on centerline were used to provide a transition correlation for the X-33 flight vehicle that was applicable across the range of reentry angles of attack. The attachment line discrete roughness results were shown to be consistent with the centerline results, as no increased sensitivity to roughness along the attachment line was identified. The effect of bowed panels was qualitatively shown to be less effective than the discrete trips; however, the distributed nature of the bowed panels affected a larger percent of the aft-body windward surface than a single discrete trip.
Characteristic-based time domain method for antenna analysis

The characteristic-based time domain method, developed in the computational fluid dynamics community for solving the Euler equations, is applied to the antenna radiation problem. Based on the principle of the characteristic-based algorithm, a governing equation in the cylindrical coordinate system is formulated directly to facilitate the analysis of body-of-revolution antennas and also to achieve the exact Riemann problem. A finite difference scheme with second-order accuracy in both time and space is constructed from the eigenvalue and eigenvector analysis of the derived governing equation. Rigorous boundary conditions for all the field components are formulated to improve the accuracy of the characteristic-based finite difference scheme. Numerical results demonstrate the validity and accuracy of the proposed technique.
The Response of Bond Prices to Insurer Ratings Changes

This paper examines the impact of insurer ratings changes on bond prices. Using insurer ratings from four major rating agencies and data covering the recent financial crisis period, we document that downgrades have a strong negative price impact on bond prices, especially when the downgrades are reinforced by multiple agencies. In contrast, the announcement-day impact of upgrades is found to be weak. Our evidence is consistent with the predictions of structural credit risk models.
Innovation in non-profit and for-profit organizations: Visionary, strategic, and financial considerations

Abstract Innovation has been widely studied in the context of for-profit organizations. Less attention has been paid in business literature to innovation in non-profit organizations. This paper lays out a model for comparison and then explores the differences between the two types of organizations. Using these data, predictions are made as to how these differences will impact the innovative behaviour of non-profit organizations and theories are proposed about the methods of innovation most suited to a non-profit organization. A theoretical model is presented which incorporates differences in vision, in strategic constraints, and in financial constraints.
Experimental Study of a High-Frequency Fluidic Valve Fuel Injector

Fuel injectors composed of an ori ce connected to a small plenum cavity were mounted on a detonation tube. These fuel injectors, termed uidic valves, utilize their geometry and a supply pressure to deliver fuel and contain no moving parts. Behavior of these uidic valves is characterized in order to determine their feasibility for integration with high-frequency pulsed or rotating detonation wave engines. Fuel ow is initiated just prior to ignition of the detonation tube to understand the interaction between the uidic valves and the wave. Parametric studies have been conducted with the type of fuel injected, the ori ce diameter, and the plenum cavity pressure. Results indicate that the detonation wave pressure temporarily shuts o the uidic valve supply, but the wave products can be quickly expelled by the fresh fuel supply to allow for refueling. The interruption time of the valve scales with the injection and detonation wave pressure ratios as well as a characteristic time.
High frequency parametric wave phenomena and plasma heating: A review

Abstract A survey of parametric instabilities in plasma, and associated particle heating, is presented. A brief summary of linear theory is given. The physical mechanism of decay instability, the purely growing mode (oscillating two-stream instability) and soliton and density cavity formation is presented. Effects of density gradients are discussed. Possible nonlinear saturation mechanisms are pointed out. Experimental evidence for the existence of parametric instabilities in both unmagnetized and magnetized plasmas is reviewed in some detail. Experimental observation of plasma heating associated with the presence of parametric instabilities is demonstrated by a number of examples. Possible application of these phenomena to heating of pellets by lasers and heating of magnetically confined fusion plasmas by high power microwave sources is discussed.
Neural Networks for Inverse Problems Using Principal Component Analysis and Orthogonal Arrays

An obstacle in applying artificial neural networks (NNs) to system identification problems is that the dimension and the size of the training set for NNs can be too large to use them effectively in solving a problem with available computational resources. To overcome this obstacle, principal component analysis (PCA) can be used to reduce the dimension of the inputs for the NNs without impairing the integrity of data and orthogonal arrays (OAs) can be used to select a smaller number of training sets that can efficiently represent the given behavior system. NNs with PCA and OAs are used here in solving two parameter identification problems in two different fields. The first problem is identifying the location of damage in cantilever plates using the free vibration response of the structure. The free vibration response is simulated using the finite element method. The second problem is identifying an anomaly in an illuminated opaque homogeneous tissue using near-infrared light based on the simulation of the photon intensity and the photon mean time of flight in perfect and imperfect tissues using the finite element method.
Synthesis of the chlorin macrocycle by the ‘3 + 1’ approach

The one-step regioselective synthesis of a chlorin macrocycle from a tripyrrane and bisformylpyrrole is described for the first time; the chlorin is furnished in 46% yield and is constructed from readily prepared pyrroles.
The distance approach to approximate combinatorial counting

We develop general methods to obtain fast (polynomial time) estimates of the cardinality of a combinatorially defined set via solving some randomly generated optimization problems on the set. Examples include enumeration of perfect matchings in a graph, linearly independent subsets of a set of vectors and colored spanning subgraphs of a graph. Geometrically, we estimate the cardinality of a subset of the Boolean cube via the average distance from a point in the cube to the subset with respect to some distance function. We derive asymptotically sharp cardinality bounds in the case of the Hamming distance and show that for small subsets a suitably defined “randomized” Hamming distance allows one to get tighter estimates of the cardinality.
A Bayesian Analysis of Return Dynamics with Lévy Jumps

We have developed Bayesian Markov chain Monte Carlo (MCMC) methods for inferences of continuous-time models with stochastic volatility and infinite-activity Levy jumps using discretely sampled data. Simulation studies show that (i) our methods provide accurate joint identification of diffusion, stochastic volatility, and Levy jumps, and (ii) the affine jump-diffusion (AJD) models fail to adequately approximate the behavior of infinite-activity jumps. In particular, the AJD models fail to capture the “infinitely many” small Levy jumps, which are too big for Brownian motion to model and too small for compound Poisson process to capture. Empirical studies show that infinite-activity Levy jumps are essential for modeling the S&P 500 index returns.
C2-symmetric bisprolinamide as a highly efficient catalyst for direct aldol reaction.

The catalytic activity of the prolinamide-type catalysts may be improved by introducing additional prolinamide moiety into the catalyst, while the enantioselectivity can still be maintained or further improved. A C2-symmetric bisprolinamide with two prolinamide moieties has been found to be an excellent catalyst for direct aldol reaction with more than doubled reactivity and better asymmetric induction than its monoprolinamide counterpart.
A look toward the future

In looking to the future in a field such as sleep medicine, there seem to be two general areas about which one could speculate: (1) the scientific accomplishments that are likely to transpire in the years ahead and (2) how (and by whom) sleep medicine will be practiced in our evolving medical system. The two are certainly not mutually exclusive areas because the science must, to some extent, dictate how health care is delivered. As a result, I address first the science and then the implications for the practice of sleep medicine.
A fusion transmutation of waste reactor

Abstract A design concept and the performance characteristics for a fusion transmutation of waste reactor (FTWR)—a sub-critical fast reactor driven by a tokamak fusion neutron source—are presented. The present design concept is based on nuclear, processing and fusion technologies that either exist or are at an advanced stage of development and on the existing tokamak plasma physics database. A FTWR, operating with keff⩽0.95 at a thermal power output of about 3 GW and with a fusion neutron source operating at Qp=1.5–2, could fission the transuranic content of about a hundred metric tons of spent nuclear fuel per full-power-year and would be self-sufficient in both electricity and tritium production. In equilibrium, a nuclear fleet consisting of Light Water Reactors (LWRs) and FTWRs in the electrical power ratio of 3/1 would reduce the actinides discharged from the LWRs in a once-through fuel cycle by 99.4% in the waste stream that must be stored in high-level waste repositories.
Palladium-Catalyzed Picolinamide-Directed Acetoxylation of Unactivated γ-C(sp3)H Bonds of Alkylamines

N-Alkylpicolinamide substrates (I) are converted into the corresponding γ-acetoxylated products in the presence of lithium carbonate, which suppresses the competing intramolecular C-H amination process.
Comparison of Single Particle and Equivalent Circuit Analog Models for a Lithium-Ion Cell

The physics-based single particle (SP) model was compared to the semi-empirical equivalent circuit analog (ECA) model to predict the cell voltage under constant current charge and discharge for different sets of Li-ion cell data. The parameters of the models were estimated for each set of data using nonlinear least squares regression. In order to enhance the probability of finding the global optima, a combination of the trust region method with a genetic algorithm was applied to minimize the objective function (the sum of squared residuals). Several statistical quantities such as sum of the squared errors, adjusted R2, root mean squared error, confidence intervals of the parameters, and prediction bounds were included to compare the models. A significance test (t test) on the parameters and the analysis of the variances (F and χ2 tests) were also performed to discriminate between the goodness of the fit obtained from the two models. The statistical results indicate that the SP model superiorly predicts all sets of data compared to the ECA model, while the computation times of both models are on the same order of magnitude.
Optical third-harmonic microscopy of graphene

We report third-harmonic generation in graphene on glass. Polarization and azimuthal-rotation data confirm graphene's isotropic symmetry properties. High-contrast imaging yields structural features and its coherent nature via layer-number dependence.
RESOLUTION OF THE MACHO-LMC-5 PUZZLE: THE JERK-PARALLAX MICROLENS DEGENERACY

By extending the constant-acceleration analysis of Smith, Mao, & Paczynski to include jerk, I show that microlens parallax measurements are subject to a four-fold discrete degeneracy. The new degeneracy is characterized by a projected velocity j = -(3/4) csc βec( ψ βec + ψ)3/2v⊕, where βec is the ecliptic latitude, ψ is the phase of the Earth's orbit relative to opposition at the time of the event maximum, and v⊕ = 30 km s-1 is the speed of the Earth. The degeneracy becomes important when the lens projected velocity is of order j. For events toward the Large Magellanic Cloud, j (3/4)v⊕, so this degeneracy is important primarily for lenses in the Milky Way disk. In particular, it solves the puzzle of MACHO-LMC-5, whose microlens parallax measurement had yielded mass and distance determinations for the lens that were inconsistent with photometric estimates. Toward the Galactic bulge, j ranges from ~0.2 km s- 1 at the summer solstice to ~200 km s- 1 at the equinoxes , so the effect of the degeneracy depends strongly on the peak time of the event. The degeneracy applies mainly to events with Einstein timescales, tE yr/2π.
LOW-POWER BIOMEDICAL SIGNAL MONITORING SYSTEM FOR IMPLANTABLE SENSOR APPLICATIONS

Implantable biomedical sensors and continuous real time in vivo monitoring of various physiological parameters requires low-power sensor electronics and wireless telemetry for transmission of sensor data. In this article, generic blocks required for such systems have been demonstrated with design examples. Ideally neural or electro-chemical sensor signal monitoring units comprise of low noise amplifiers, current or voltage mode analog to digital domain data conversion circuits and wireless telemetry circuits. The low-noise amplifier described here has a novel open loop amplifier scheme used for neural signal recording systems. The design has been implemented using 0.5-μm SOI-BiCMOS process. The fabricated chip can work with 1 V supply and consumes 805 nA. The current mode analog to digital conversion signal processing circuitry takes the current signal as an input and generates a pulse-width modulated data signal. The data signal is then modulated with a high frequency carrier signal to generate FSK data for wireless transmission. The design is fabricated in 0.5-μm standard CMOS process and consumes 1.1 mW of power with 3.5 V supply.
On consistent boundary conditions for c = 1 string theory

Abstract We introduce a new parametrisation for the Fermi sea of the c = 1 matrix model. This leads to a simple derivation of the scattering matrix, and a calculation of boundary corrections in the corresponding (1 + 1)-dimensional string theory. The new parametrisation involves relativistic chiral fields, rather than the non-relativistic fields of the usual formulations. The calculation of the boundary corrections, following recent work of Polchinski, allows us to place restrictions on the boundary conditions in the matrix model. We provide a consistent set of boundary conditions, but believe that they need to be supplemented by some more subtle relationship between the space-time and matrix model. Inspired by these boundary conditions, some thoughts on the black hole in c = 1 string theory are presented.
Efficient Alkyl Ether Synthesis via Palladium-Catalyzed, Picolinamide-Directed Alkoxylation of Unactivated C(sp3)–H and C(sp2)–H Bonds at Remote Positions

We report the efficient synthesis of alkyl ethers by the functionalization of unactivated sp3- and sp2-hybridized C–H bonds. In the Pd(OAc)2-catalyzed, PhI(OAc)2-mediated reaction system, picolinamide-protected amine substrates undergo facile alkoxylation at the γ or δ positions with a range of alcohols, including t-BuOH, to give alkoxylated products. This method features a relatively broad substrate scope for amines and alcohols, inexpensive reagents, and convenient operating conditions. This method highlights the emerging value of unactivated C–H bonds, particularly the C(sp3)–H bond of methyl groups, as functional groups in organic synthesis.
Experimental investigation of propfan aeroelastic response in off-axis flow with mistuning

Measured vibratory strain amplitudes from off-axis flow are compared for the blades of two, 8-bladed propfan model rotors with mistuning. One rotor had inherent mistuning. The other was intentionally mistuned by replacing every other blade of the first rotor with a blade of same geometry but different frequencies and mode shapes. The data shows that the intentional mistuning had a beneficial effect on the aeroelastic response of the propfan motors for a wide range of off-axis flow angles, blade pitch angles, and rotational speeds. Statistical trends of blade strain amplitudes are compared for both the rotors in terms of the ratio of the maximum to the mean and the coefficient of variation.
$L^p$ asymptotic behavior of perturbed viscous shock profiles

We investigate the Lp asymptotic behavior (1 ≤ p ≤ ∞) of a perturbation of a Lax or overcompressive type shock wave solution to a system of conservation law in one dimension. The system of the equations can be strictly parabolic, or partially parabolic (real viscosity case, e.g. compressible Navier–Stokes equations or equations of Magnetohydrodynamics). We use known pointwise Green function bounds for the linearized equation around the shock to show that the perturbation of such a solution can be decomposed into a part corresponding to shift in shock position or shape, a part which is the sum of diffusion waves, i.e. the solutions to a viscous Burger's equation, conserving the initial mass and convecting away from the shock profile in outgoing modes, and another part which is more rapidly decaying in any Lp norm.
Resource estimation on wireless backhaul networks

The increased usage of IEEE 802.11 wireless backhaul networks and the growing popularity of real time applications, such as VoIP, presents a challenging resource management problem due to the limited capacity of wireless networks. At high traffic volumes, measurements have shown that packet collisions and interference in 802.11 networks can lead to degraded performance to the extent that users experience unacceptably low throughput, which can ultimately lead to complete network breakdown [1]. A resource management framework that limits network flows can prevent network breakdown and improve the performance of throughput and delay-sensitive multimedia applications. To address this problem, we present a measurement-driven framework that leverages wireless characteristics for intelligent admission control in a static wireless network. Experiments on a 25 node wireless testbed show that the proposed scheme can enhance network performance such that the QoS requirements of real time applications, such as VoIP, can be met.
Permutation patterns, Stanley symmetric functions, and generalized Specht modules

Abstract Generalizing the notion of a vexillary permutation, we introduce a filtration of S ∞ by the number of terms in the Stanley symmetric function, with the kth filtration level called the k-vexillary permutations. We show that for each k, the k-vexillary permutations are characterized by avoiding a finite set of patterns. A key step is the construction of a Specht series, in the sense of James and Peel, for the Specht module associated with the diagram of a permutation. As a corollary, we prove a conjecture of Liu on diagram varieties for certain classes of permutation diagrams. We apply similar techniques to characterize multiplicity-free Stanley symmetric functions, as well as permutations whose diagram is equivalent to a forest in the sense of Liu.
Experimental Techniques for the Assessment of Fuel Thermal Stability

Two different methods for characterizing the thermal oxidative tendencies of aviation fuels have been developed. A common feature of both methods is that the fuel being tested is passed through a heated tube which is maintained at a constant temperature throughout the test duration. One is a closed-loop system in which the fuel is recirculated continuously for periods of up to 22 h. The other is a single-pass device whereby the test fuel flows only once through the heated tube. These two methods and their relative merits are discussed in some detail, and the extent to which they simulate an actual aircraft fuel system is assessed alongside that of a more established test technique which maintains a constant heat flux through the tube wall and allows the wall temperature to increase continuously throughout the test duration.
An unexpected sialylation: Total syntheses of GM4 and a positional isomer

The use of glycals 3 and 4 as precursors to 1,2-anhydrosugars greatly simplifies the installation of a β-linked ceramide glycoside. By permuting the introduction of the ceramide and the sialic acid, one can access the ganglioside G M4 (1) and, by an unexpected regioselective glycosylation, its NeuAc (2→2) Gal positional isomer 10
Is Thermal Expansion Driving the Initial Gas Ejection in NGC 6251

The relativistic jets in active galactic nuclei (AGNs) are probably driven by the action of supermassive, spinning black holes. There is very little direct evidence for this, however, since the nuclei of active galaxies are difficult to study. This is now changing with new, high-resolution multiwavelength observations of nearby sources such as Sgr A* at the Galactic center and the nucleus of NGC 6251 (hereafter called NGC 6251*). In this paper, we explore the possibility that the radiative properties of the most compact region in NGC 6251* may be understood in the same sense as Sgr A*, though with some telling differences that may hint at the nature of jet formation. We show that observations of this object with ASCA, ROSAT, HST, and VLBI together may be suggesting a picture in which Bondi-Hoyle accretion from an ambient ionized medium feeds a standard disk accreting at ~ 4.0 × 1022 g s-1. Somewhere near the event horizon, this plasma is heated to more than 1011 K, where it radiates via thermal synchrotron (producing a radio component) and self-Comptonization (accounting for a nonthermal X-ray flux). This temperature is much greater than its virial value and the hot cloud expands at roughly the sound speed (~0.1c), after which it begins to accelerate on a parsec scale to relativistic velocities. In earlier work, the emission from the extended jet has been modeled successfully using nonthermal synchrotron self-Compton processes, with a self-absorbed inner core. In the picture we are developing here, the initial ejection of matter is associated with a self-absorbed thermal radio component that dominates the core emission on the smallest scales. The nonthermal particle distributions responsible for the emission in the extended jet are then presumably energized, e.g., via shock acceleration, within the expanding, hot gas. The power associated with this plasma represents an accretion efficiency of about 0.54, requiring dissipation in a prograde disk around a rapidly spinning black hole (with spin parameter a ~ 1).
Generation of very flat optical frequency combs from continuous-wave lasers using cascaded intensity and phase modulators driven by tailored radio frequency waveforms

We demonstrate a scheme based on a cascade of lithium niobate intensity and phase modulators driven by specially tailored RF waveforms to generate an optical frequency comb with very high spectral flatness. In this Letter, we demonstrate a 10 GHz comb with 38 comb lines within a spectral power variation below 1 dB. The number of comb lines that can be generated is limited by the power handling capability of the phase modulator, and this can be scaled without compromising the spectral flatness. Furthermore, the spectral phase of the generated combs in our scheme is almost purely quadratic, which, as we will demonstrate, allows for high-quality pulse compression using only single-mode fiber.
Chain-link hydrogen-bonded capsules

An approach to the design, synthesis and characterization of chain-link hydrogen-bonded capsules is described. The process involves the self-assembly of a series of bipyrimidines, namely 5,5′-bipyrimidine, 1,2-bis(5′pyrimidyl)ethyne and 1,2-bis(5′pyrimidyl)ethene with C-methyl calix[4]resorcinarene. The structures of resultant chain-link hydrogen-bonded capsules are presented.
Acquisition of a unique cue in positive and negative patterning

Forty college students received a classical differential conditioning procedure involving both positive and negative patterning, each of these being associated with a different pair of stimuli. In positive patterning, elemental stimuli, A and B, were presented without an unconditioned stimulus while their compound, AB, was paired with electric shock. In negative patterning, elemental stimuli, C and D, were paired with shock while their compound, CD, remained unpaired. Thirty of these subjects then received a negative patterning transfer test on new stimuli, while ten subjects received a positive patterning transfer test. First interval response (FIR) and second interval response (SIR) were measured. During initial acquisition, positive patterning occurred in both dependent measures, but negative patterning was present only in the SIR. The transfer tests showed almost significant transfer of positive patterning in FIR and SIR. Negative patterning showed significant transfer neither in FIR nor SIR. It was concluded that, although elementary models of conditioning can explain positive patterning on the basis of summation of excitation from the elements to the compound, the occurrence of negative patterning in the SIR and the almost significant transfer of positive patterning in FIR and SIR appear to require the additional assumption of a unique cue.
Novanet communications network for a control system

Novanet is a control system oriented fiber optic local area network that was designed to meet the unique and often conflicting requirements of the Nova laser control system which will begin operation in 1984. The computers and data acquisition devices that form the distributed control system for a large laser fusion research facility need reliable, high speed communications. Both control/status messages and experimental data must be handled. A subset of NOVANET is currently operating on the two beam Novette laser system.
Reconciliation of generalized refraction with diffraction theory

When an electromagnetic wave is obliquely incident on the interface between two homogeneous media with different refractive indices, the requirement of phase continuity across the interface generally leads to a shift in the trajectory of the wave. When a linearly position-dependent phase shift is imposed at the interface, the resulting refraction may be described using a generalized version of Snell's law. In this Letter, we establish a formal equivalence between generalized refraction and blazed diffraction gratings, further discussing the relative merits of the two approaches.
On the Classification of Cartan Actions

We study higher-rank Cartan actions on compact manifolds preserving an ergodic measure with full support. In particular, we classify actions by \(\mathbb{R}^{k}\) with k ≥ 3 whose one-parameter groups act transitively as well as nondegenerate totally nonsymplectic \(\mathbb{Z}^{k}\)-actions for k ≥ 3.
Megaton Water Cerenkov Detectors and Astrophysical Neutrinos

Although formal proposals have not yet been made, the UNO and Hyper-Kamiokande projects are being developed to follow-up the tremendously successful program at Super-Kamiokande using a detector that is 20-50 times larger. The potential of such a detector to continue the study of astrophysical neutrinos is considered and contrasted with the program for cubic kilometer neutrino observatories.
Production of Narrow Balmer Spectrum Lines in an Electron-Bombarded Atomic Hydrogen Beam

An apparatus is described which has produced and detected narrow Hβ and Hγ spectral lines in an electron-bombarded atomic hydrogen beam. Hydrogen atoms produced in an electrodeless 50-Mc/sec discharge in wet hydrogen, diffused through a slit in the discharge tube wall to form a beam in a vacuum chamber. An electron gun bombarded the atomic beam along an axis perpendicular to the beam and optical axes; light produced in the decay of atoms excited by the bombardment was analyzed by a pressure-scanned Fabry–Perot interferometer and detected by a cooled photomultiplier. The output pulses from the photomultiplier were amplified and then stored as counts in a 400-channel analyzer. Linewidths characteristic of a source at about 33°K were obtained; however, the signals were so small and the line shapes sufficiently uncertain that no precise wavelength measurements could be made.
Uniform modulus of continuity of random fields

A sufficient condition for the uniform modulus of continuity of a random field \(X = \{X(t), t \in \mathbb R^{N}\}\) is provided. The result is applicable to random fields with heavy-tailed distribution such as stable random fields.
Neighborhood matters: The impact of location on broad based stock option plans ☆

Abstract We find that fixed effects related to the location of firms’ headquarters explain variation in broad based option grants after controlling for industry effects and firm characteristics traditionally known to affect option granting. Location matters because of local labor market conditions and social interaction with neighboring firms. Broad based option grants are higher: (i) when a firm's stock prices co-move more with stock prices of other firms located in that Metropolitan Statistical Area (MSA); (ii) in states that are less likely to enforce non-compete agreements; and (iii) in MSAs where employees prefer options because stocks there experience abnormally high returns.
Parton Cascades in High-Energy Nuclear Collisions

This is a review of the parton cascade model (PCM) which provides a QCD-based description of nucleus-nucleus reactions at very high energy. The PCM describes the collision dynamics within the early and dense phase of the reaction in terms of the relativistic, probabilistic transport of perturbative excitations (partons) of the QCD vacuum, combined with the renormalization group flow of the parton virtuality. The current state of numerical implementations of the model, as well as its predictions for nuclear collisions at RHIC and LHC are discussed.
SERTS-95 Measurements of Wavelength Shifts in Coronal Emission Lines Across a Solar Active Region

We used slit spectra from the 18 November 1997 flight of Goddard Space Flight Center’s Solar EUV Rocket Telescope and Spectrograph (SERTS-97) to measure relative wavelength shifts of coronal emission lines as a function of position across NOAA active region 8108. The shifts are measured relative to reference wavelengths derived from spectra of the region’s nearby quiet surroundings (not necessarily at rest) because laboratory rest wavelengths for the coronal EUV lines have not been measured to sufficient accuracy for this work. An additional benefit to this approach is that any systematic uncertainties in the wavelength measurements are eliminated from the relative shifts by subtraction. We find statistically significant wavelength shifts between the spatially resolved active region slit spectra and the reference spectrum. For He II 303.78 A the maximum measured relative red shift corresponds to a Doppler velocity ∼ +13 km s−1, and the maximum relative blue shift corresponds to a Doppler velocity ∼ −3 km s−1. For Si X 347.40 A, Si XI 303.32 A, Fe XIV 334.17 A, and Fe xvi 335.40 A the corresponding maximum relative Doppler velocities are ∼ +19 and ∼ −14, ∼ +23 and ∼ −7, ∼ +10 and ∼ −10, and ∼ +13 and ∼ −5 km s−1, respectively. The active region appears to be divided into two different flow areas; hot coronal lines are predominantly red-shifted in the northern half and either blue-shifted or nearly un-shifted in the southern half. This may be evidence that material flows up from the southern part of the region, and down into the northern part. Qualitatively similar relative wavelength shifts and flow patterns are obtained with SOHO/CDS spectra.
Experiments on ladders reveal a complex interplay between a spin-gapped normal state and superconductivity

In recent years, the study of ladder materials has developed into a well-established area of research within the general context of strongly correlated electrons. This effort has been triggered by an unusual cross-fertilization between theory and experiments. In this paper, the main experimental results obtained in the context of ladders are reviewed from the perspective of a theorist. Emphasis is given to the many similarities between the two-dimensional high-Tc cuprates and the two-leg ladder compounds, including Sr14-xCaxCu24O41 ([14-24-41]) which has a superconducting phase at high pressure and a small hole density. Examples of these similarities include regimes of linear resistivity versus temperature in metallic ladders and a normal state with spin gap or pseudogap characteristics. It is remarked that the ladder [14-24-41] is the first superconducting Cu oxide material with a non-square-lattice layered arrangement, and certainly much can be learned from a careful analysis of this compound. A short summary of the main theoretical developments in this field is also included, as well as a brief description of the properties of non-Cu-oxide ladders. Suggestions by the author on possible experiments are described in the text. Overall, it is concluded that the enormous experimental effort carried out on ladders has already unveiled quite challenging and interesting physics that adds to the rich behaviour of electrons in transition metal-oxides, and in addition contributes to the understanding of the two-dimensional cuprates. However, considerable work still needs to be carried out to fully understand the interplay between charge and spin degrees of freedom in these materials.
Generating context-appropriate word orders in Turkish

Turkish, like Finnish, German, Hindi, Japanese, and Korean, has considerably freer word order than English. In these languages, word order variation is used to convey distinctions in meaning that are not generally captured in the semantic representations that have been developed for English, although these distinctions are also present-in somewhat less obvious ways in English. In the next section, I present a summary of the linguistic data on Turkish word order variations. Section 3 describes the categorial formalism I propose to model the syntax, semantics, and pragmatic information in Turkish sentences. To capture the syntax of free word order languages, I present an adaptation of Combinatory Categorial Grammars, CCGs (Steedman-85; Steedman-91), called {}-CCGs (set-CCGs). Then, I integrate a level of information structure, representing pragmatic functions such as topic and focus, with {}-CCGs to allow pragmatic distinctions in meaning to influence the word order of the sentence in a compositional way. In Section 4, I discuss how this strategy is used within a generation system which produces Turkish sentences with word orders appropriate to the context, and include sample runs of the implementation.
Phantom Towers: Feminist reflections on the battle between global capitalism and fundamentalist terrorism

Rosalind P. Petchesky asks whether there is some alternative, more humane and peaceable way out of the two unacceptable polarities now being presented to us: the permanent war machine (or permanent security state) and the regime of holy terror. She sketches out the post September 11th global power dynamics, including their gendered and racialized dimensions.
Differential rotation in a solar-driven quasi-axisymmetric circulation

The concept of a quasi-axisymmetric circulation is used to explore the global scale dynamics of planetary atmospheres. A numerical circulation model applicable to Jupiter is presented, and an analytical study is performed elucidating the conditions leading to differential rotation in an atmosphere which is convectively unstable. A linear system forced by solar differential heating is considered, with nonlinear effects arising from advection being represented in the form of eddy diffusion. An empirical, latitudinal spectrum of the observed zonal wind field on Jupiter is discussed. Numerical solutions are presented which reveal banded wind fields with alternating and equatorial zonal jets and a multicellular Ferrel-Thomson meridional circulation consistent with the observed cloud striations on Jupiter. The vertical derivatives are parameterized to construct a simplified one-layer model.
Low‐Field Magnetic Properties of Amorphous Alloys

The transition-metal-based ferromagnetic amorphous alloys made by the continuous splat-quenching method are excellent soft magnetic materials with low coercivity. Furthermore, their low-field magnetic properties are sensitive to heat treatments and can be greatly improved by such treatments. A review of low-field properties of these alloys such as anisotropy, remanence, and coercivity (as-received and after heat treatments) is presented together with data on the Fe/sub 80/B/sub 20/ amorphous alloy and the effect of fast-neutron irradiation.
Compiler Algorithms for Optimizing Locality and Parallelism on Shared and Distributed-Memory Machines

Distributed-memory message-passing machines deliver scalable performance but are difficult to program. Shared-memory machines, on the other hand, are easier to program but obtaining scalable performance with large number of processors is difficult. Recently, scalable machines based on logically shared physically distributed memory have been designed and implemented. While some of the performance issues like parallelism and locality are common to different parallel architectures, issues such as data distribution are unique to specific architectures. One of the most important challenges compiler writers face is the design of compilation techniques that can work well on a variety of architectures. In this paper, we propose an algorithm that can be employed by optimizing compilers for different types of parallel architectures. Our optimization algorithm does the following: (1) transforms loop nests such that, where possible, the iterations of the outermost loops can be run in parallel across processors; (2) optimizes memory locality by carefully distributing each array across processors; (3) optimizes interprocessor communication using message vectorization whenever possible; and (4) optimizes cache locality by assigning appropriate storage layout for each array and by transforming the iteration space. Depending on the machine architecture, some or all of these steps can be applied in a unified framework. We report empirical results on an SGI Origin 2000 distributed-shared-memory multiprocessor and an IBM SP-2 distributed-memory message-passing machine to validate the effectiveness of our approach.
Activity patterns of Californians: Use of and proximity to indoor pollutant sources

Abstract The California Air Resources Board funded a statewide survey of activity patterns of Californians over 11 years of age in order to improve the accuracy of exposure assessments for air pollutants. Telephone interviews were conducted with 1762 respondents over the four seasons from fall 1987 through summer 1988. In addition to completing a 24-h recall diary of activities and locations, participants also responded to questions about their use of and proximity to potential pollutant sources. Results are presented regarding time spent by Californians in different activities and locations relevant to pollutant exposure, and their frequency of use of or proximity to pollutant sources including cigarettes, consumer products such as paints and deodorizers, combustion appliances and motor vehicles. The results show that Californians spend, on average, 87% of their time indoors, 7% in enclosed transit and 6% outdoors. At least 62% of the population over 11 years of age and 46% of nonsmokers are near others' tobacco smoke at some time during the day. Potential exposure to different pollutant sources appears to vary among different gender and age groups. For example, women are more likely to use or be near personal care products and household cleaning agents, while men are more likely to be exposed to environmental tobacco smoke, solvents and paints. Data from this study can be used to reduce significantly the uncertainty associated with risk assessments for many pollutants.
Are There Quantum Jumps

A quantum statistical theory is developed for a single atom, three-state quantum system where a strong (1–3) and a weak (2–3) transition are driven resonantly by an incoherent field. From a second order correlation function of the fluorescence intensity, it is concluded that a quantum jump can occur, in the sense that the single atom can undergo large fluctuations between a state of full emission in the strong transition to a state of no emission when the electron is shelved in the metastable state (2).
Spectroscopic constants and potential energy curves for 16 electronic states of AsH

Abstract Relativistic complete active space multi-configuration SCF (CASSCF) followed by full secondorder configuration interaction (SOCI) calculations are carried out on 16 electronic states of AsH. Among these are found 11 bound states for which spectroscopic constants are reported. Potential energy curves of all 16 electronic states are computed. Spectroscopic constants of nine new electronic states of AsH which are yet to be observed are reported. The experimentally observed predissociation and Λ-doubling in the A3Π ← X3Σ− system are explained based on theoretical potential energy curves. The dipole moment curves for the low-lying states are presented. The nature of the lowlying electronic states is analyzed through CI wave functions and Mulliken population analyses. The theoretical spectroscopic constants of the X3Σ− state are R e = 1.528 A , ωe = 2194 cm−1, De = 2.71 eV, μe = 0.18 D, in excellent agreement with the experimental values of R e = 1.535 A , ωe = 2130 cm−1, and De = 2.80 eV.