Miracle-dz/UniFAR-FTUs huggingface dataset:
Holographic storage in electrooptic crystals. i. steady state

The non-linear theory of the self-diffraction on the light induced grating of refractive index in electrooptic crystals is developed. The intensities of the diffracted beams, the diffraction efficiency, and the shape of the surfaces of equal index change are calculated analytically for saturation holograms.Holographic storage in nominally pure reduced crystals of LiNbO3 is studied experimentally. It is shown that the developed theory in diffusion approximation satisfactorily describes the experimental data.
Supernovae as a standard candle for cosmology.

Supernovae can perhaps be found at Zapprox. =1 using the Space Telescope and the Focal Plane Camera (cryogenic charge coupled devices) at a rate of approximately four per week using 3 hours per week of viewing time. If Type II supernovae are used as a self-calibrating candle at Zvery-much-less-than1, then Type I's can be calibrated from Type II's as a secondary standard candle (2 mag brighter) and used instead of Type II's for a less difficult determination of q/sub 0/. This assumes all Type I's are the same independent of Z whereas each Type II is self-calibrated. Adequate statistics of supernovae in nearby galaxies Z< or approx. =1 can further verify the uniqueness of Type I's. Three-color wide-band photometry performed over the period of the maximum luminosity of a Type I gives the time dilation proportional (1+Z)/sup -1/, color shift proportional (1+Z)/sup -1/, and apparent luminosity proportionalZ/sup -2/(1+0.5(1+q/sub 0/) Z+O (Z))/sup -2/ (1+Z)/sup -2/. A Type I supernova at maximum and Z=1, H/sub 0/=50, should give rise to a statistically meaningful maximum single pixel signal of approx.250 photoelectrons compared to an average galaxy center background of approx.25 photoelectrons for an 80 s integration time. An average of approx.100 large galaxiesmore » (10/sup 10/L/sub sun/) per field allows approx.10/sup 4/ galaxies to be monitored using 3 hours of viewing time. Z can be determined by time dilation and color shift sufficiently accurately that the determination of q/sub 0/ will have twice the error of the calibration of Type I as a standard candle. « less
SIZE-DEPENDENT DYNAMICS OF COHERENT ACOUSTIC PHONONS IN NANOCRYSTAL QUANTUM DOTS

Confined acoustic phonons in InAs nanocrystals are observed in the time domain by femtosecond pump-probe spectroscopy. The size dependence of both frequency and damping time is investigated for InAs. The frequency of the discrete modes varies between 18 and 30 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ for a nanocrystal radius ranging from 28 to 12 \AA{}, and the dependence deviates from the expected $1/R$ behavior at small sizes. The damping rate is found to vary linearly with $1/R,$ suggesting coupling to the matrix through the particle surface as a main damping route. This is corroborated by observing faster damping for the acoustic mode in solution compared to a polymer environment. The coupling strength is found to depend on material parameters: in CdSe nanocrystals, weaker coupling is observed. The role of acoustic phonon coupling in the dephasing dynamics of semiconductor nanocrystals is discussed.
Distortion of plasma due to installation of a grid in homogeneous He positive columns

Distortion in a weakly ionized homogeneous plasma caused by the installation of a mesh-grid is investigated in a wave-free He positive column. The installation causes distortion in the axial as well as the radial direction, the so-called double-sheath. Such a structure decelerates electrons in a phase of weak electric field, while it accelerates them in that of strong electric field, eventually resulting in a double-humped electron energy distribution function (EEDF). The detected axial variation of the EEDF is compared with a solution of the Boltzmann equation including the spatial derivative.
The double-humped fission barrier

The concept of the double-humped fission barrier of actinide nuclei has made possible an understanding of a vast amount of data on nuclear fission during the past decade. In this article the analysis of most available relevant data is reviewed, and a synthesis of the fission barrier parameters and their trends over the actinide region is built up. The sequence of the work begins with an outline (but not a critical discussion) of the theoretical foundation of the double-humped barrier, and this is followed by a full account of the nuclear reaction theory required to describe fission reactions within the concept of such a barrier. This reaction theory provides the theoretical tools for a quantitative understanding of a range of phenomena of such kinds as spontaneously fissioning isomers, their half-live and yields, vibrational resonances and narrower intermediate structure in fission cross sections, and the general trends and magnitudes of fission cross sections at excitation energies near the top of the fission barrier. The magnitudes and trends of fission barrier parameters and the level structure of highly deformed nuclei that are extracted from the data on these phenomena are discussed in the light of current concepts of nuclear structure. Also, themore » possibility of a three-humped and more complex barriers is reviewed. « less
Evidence-Based Identification of Weighting Factors in Bayesian Model Updating Using Modal Data

In Bayesian model updating, parameter identification of structural systems using modal data can be based on the formulation of the likelihood function as a product of two probability density functions, one relating to modal frequencies and one to mode-shape components. The selection of the prior distribution of the prediction-error variances relating to these two types of data has to be performed carefully so that the relative contributions are weighted to give balanced results. A methodology is proposed in this paper to select these weights by performing Bayesian updating at the model class level, where the model classes differ by having different ratios of the two prediction-error variances. The most probable model class on the basis of the modal data then gives the best choice for this variance ratio. Two illustrative examples, one using simulated data and one using experimental data, point out the effect of the different relative contributions of the modal frequencies and mode-shape components to the total amount of information extracted from the modal data.
Kinematics of Star Clusters in M33

Velocities are presented for about 45 M33 star clusters, spanning the range of cluster ages (about 0.1-10 Gyr) in that system. It is concluded that: (1) there is a kinematic halo of old clusters, with a velocity dispersion of about 70 km/s; (2) there is little or no sign of rotation for the old, metal-poor cluster system (V/sigma not greater than 0.6); (3) young (blue) clusters rotate sensibly with the H I and H II disk gas (V/sigma not less than 5); and (4) the intermediate age/color clusters have similar rotational motion to the young clusters, with a marginally lower rotational velocity and higher dispersion. Although the properties of these clusters resemble those of the LMC clusters in terms of star formation history, the kinematics of the M33 clusters appear significantly different from what has been reported for the LMC cluster system, and more closely mimic the kinematics of the Milky Way system. These results are discussed in terms of disk heating and diffusion arguments versus collapse or formation scenarios. 44 refs.
Sequential Measurements of Cosmic-Ray Neutron Spectrum and Dose Rate at Sea Level in Sendai, Japan

The cosmic-ray neutron energy spectrum and dose rate were measured sequentially for two years from April 2001 up to March 2003 by using three neutron detectors, a 3He-loaded multi-moderator detector (Bonner ball), 12.7 cm diameter by 12.7 cm long NE213 organic liquid scintillator, and high-sensitivity rem (dose equivalent) counter at the Kawauchi campus of Tohoku University in Sendai, Japan of geomagnetic latitude, 29°N, and cutoff rigidity, 10.43 GV. The neutron spectrum has three major peaks, thermal energy peak, evaporation peak around 1 MeV and cascade peak around 100 MeV. The ambient neutron dose equivalent rates measured by the rem counter, and the Bonner ball keep almost constant values of 4.0 and 6.5 (nSv/h), respectively, throughout this time period, after atmospheric pressure correction, and it often decreased about 30% after a large Solar Flare, that is called as the Forbush decrease. The total neutron flux was also obtained by the Bonner ball measurements to be 7.5×10-3 (n cm−2.s−1) in average. The altitude variation of neutron flux and dose was also investigated by comparing the measured results with other results measured at Mt. Fuji area and aboard an airplane, where the cutoff rigidities are similar.
Lyman α scattering in the Earth's hydrogen geocorona: 2.

Analysis of experiments bearing on Lyman α excitation in the night glow leaves two possible explanations. One is a combination of direct scattering in a distant hydrogen cloud following the earth and multiple scattering in the thermosphere and exosphere. There is a difficulty accounting for the presence of the hydrogen cloud or geocoma. The other explanation is that during the night the thermosphere and exosphere contain 4 to 5 times as much hydrogen per unit column above 120 km as during the day. Although considerably more hydrogen is expected at night because of the much lower temperature, it is questionable whether a large enough change can occur in half a day.
Inkjet-printed stretchable silver electrode on wave structured elastomeric substrate

We report high performance and stable inkjet-printed stretchable silver electrodes on wave structured elastomeric substrates. Highly conductive silver electrodes were deposited directly on a ultraviolet ozone treated polydimethylsiloxane (PDMS) substrates having vertical wavy structures. Adhesion between printed silver lines and PDMS surface has been enhanced by intentionally roughened PDMS surface with wire-electro discharge machined aluminum mold. During slow (16.7 μm/s) stretching test, resistance of the printed silver electrode was increased only by three times at 30% tensile strain. Inkjet-printed silver electrodes also showed good mechanical stability during 1000-time fast (1 mm/s) cycling test with 10% tensile strain, showing maximum resistance change of less than three times.
Integral equations for a class of problems concerning obstacles in waveguides

In this paper we consider the two-dimensional boundary-value problem that arises when the Helmholtz equation is solved in a parallel-plate waveguide on the centreline of which is placed an obstacle that is symmetric about the centreline but which has otherwise arbitrary shape. The normal derivative of the unknown potential ϕ is specified on the surface of the obstacle. Two problems are considered in detail. First the problem of determining any trapped-mode wavenumbers is considered and secondly the problem of the scattering of an incident wave by the obstacle is examined. The solutions to these problems are sought using integral equations. Both problems have relevance in acoustics and in water-wave theory.
Transient finite element method for calculating steady state three-dimensional free surfaces

In order to reduce the cost of large three-dimensional calculations of steady state free surfaces, we have combined a time-dependent approach, a decoupling algorithm and a conjugate gradient solver along the lines introduced earlier by Gresho and Chan. The free surface is calculated separately by applying the kinematic condition to a number of faces defined on the undeformed surface. For the pseudo-time-marching technique we show that it is economical to adopt different time steps for the free surface calculation and the other fields. The accuracy of the method is tested on the well-known circular die problem; the method is then used to reveal the effects of inertia and shear thinning on square and rectangular dies.
Parareal in time approximation of the Korteveg‐deVries‐Burgers' equations

The parareal in time algorithm is a predictor corrector method that allows to get parallelisation through the time. It consists in segmenting the interval of time integration into slabs, then propose iteratively seed values at the left hand side of each of the slabs. The derivation of the seed values is done sequentially and involves propagator that should mimic the equation to be solved but should be very cheap and parallel accurate propagations of each seed value over each slab. Various approaches have been proposed to get the coarse propagator, in this paper, we use the averaging approach developed by Barenblatt and Chorin for the Korteveg‐deVries‐Burgers' equations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dibenzoylmethane Protects Against CCl4-Induced Acute Liver Injury by Activating Nrf2 via JNK, AMPK, and Calcium Signaling

Oxidative stress is an important pathogenic factor in various hepatic diseases. Nuclear factor-erythroid 2-related factor-2 (Nrf2), which coordinates the expression of an array of antioxidant and detoxifying genes, has been proposed as a potential target for prevention and treatment of liver disease. Dibenzoylmethane (DBM) is a minor ingredient in licorice that activates Nrf2 and prevents various cancers and oxidative damage. In the present study, the mechanisms by which DBM activates Nrf2 signaling were delineated, and its protective effect against carbon tetrachloride (CCl4)-induced liver injury was examined. DBM potently induced the expression of HO-1 in cells and in the livers of mice, but this induction was diminished in Nrf2-deficient mice and cells. Overexpression of Nrf2 enhanced DBM-induced HO-1 expression, while overexpression of a dominant-negative fragment of Nrf2 inhibited this induction. DBM treatment resulted in dissociation from Keap1 and nuclear translocation of Nrf2. Moreover, DBM activated Akt/protein kinase B, mitogen-activated protein kinases, and AMP-activated protein kinase and increased intracellular calcium levels. Inhibition of JNK, AMPK, or intracellular calcium signaling significantly suppressed the induction of HO-1 expression by DBM. Finally, DBM treatment significantly inhibited CCl4-induced acute liver injury in wild-type but not in Nrf2-deficient mice. Taken together, our results revealed the mechanisms by which DBM activates Nrf2 and induces HO-1 expression, and provide molecular basis for the design and development of DBM and its derivatives for prevention or treatment of liver diseases by targeting Nrf2.
A class of estimators of the survival function from interval-censored data

A model of interval censorship of a failure time T is considered when there is only one inspection time Y. The observable data are n independent copies of the pair (Y, δ), where δ = [T ≤ Y]. We construct a class of self-consistent estimators of the survival function of T defined implicitly through two equations and show their strong consistency under certain conditions. The properties of the nonparametric maximum likelihood estimator are also investigated.
Mpchecker: Use-After-Free Vulnerabilities Protection Based on Multi-Level Pointers

Highly efficient languages, such as C/C++, have low-level control over memory. Due to the lack of validity detection for pointers and garbage collection for memory, developers are responsible for dynamic memory management by explicitly allocating and deallocating memory. However, explicit memory management brings a large number of memory safety-related vulnerabilities, such as use-after-free. The threat of use-after-free vulnerabilities has become more and more serious due to their high level of the severity and quick emergence of the number. In this paper, a dynamic defense system is proposed against use-after-free exploits by introducing an approach based on multi-level pointers that insert intermediate pointers between a heap object and its related pointers. First, the relationship between a heap object to be protected, and the related pointers pointing to it, is established by combing with intermediate pointers. Then, all of the accesses to this object via its related pointers can only be achieved through these intermediate pointers. Finally, to prevent the dangling pointers from being dereferenced to this object, all the intermediate pointers related to this object are invalidated when it is freed so that any access to a freed object can be prevented due to the invalidated intermediate pointers. The prototype system MPChecker is implemented, which can prevent use-after-free exploits for C/C++ multi-threaded programs. Compared with the related methods, MPChecker can protect pointers that are copied in a type-unsafe way from being dereferenced to freed objects. In addition, it can also defend against dangling pointers located on the whole memory, including the stack, the heap, and global memory, rather than the heap only. The defense capability is proved by protecting against two exploits to a real-world program, comparing the support of type-unsafe copy with a self-written program. The performance evaluation of MPChecker with some benchmarks, multi-threaded programs, and real-world programs, shows its comparable efficiency.
Facility location models for immobile servers with stochastic demand

This paper presents several models for the location of facilities subject to congestion. Motivated by applications to locating servers in communication networks and automatic teller machines in bank systems, these models are developed for situations in which immobile service facilities are congested by stochastic demand originating from nearby customer locations. We consider this problem from three different perspectives, that of (i) the service provider (wishing to limit costs of setup and operating servers), (ii) the customers (wishing to limit costs of accessing and waiting for service), and (iii) both the service provider and the customers combined. In all cases, a minimum level of service quality is ensured by imposing an upper bound on the server utilization rate at a service facility. The latter two perspectives also incorporate queueing delay costs as part of the objective. Some cases are amenable to an optimal solution. For those cases that are more challenging, we either propose heuristic procedures to find good solutions or establish equivalence to other well‐studied facility location problems. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Reliable electron-only devices and electron transport in n-type polymers

Current-voltage analysis of single-carrier transport is a popular method for the determination of charge carrier mobilities in organic semiconductors. Although in widespread use for the analysis of hole transport, only a few reports can be found where the method was applied to electron transport. Here, we summarize the experimental difficulties related to the metal electrode leakage currents and nonlinear differential resistance (NDR) effects and explain their origin. We present a modified preparation technique for the metal electrodes and show that it significantly increases the reliability of such measurements. It allows to produce test devices with low leakage currents and without NDR even for thin organic layers. Metal oxides were often discussed as a possible cause of NDR. Our measurements on forcibly oxidized metal electrodes demonstrate that oxide layers are not exclusively responsible for NDR effects. We present electron transport data for two electron-conducting polymers often applied in all-polymer solar cells for a large variety of layer thicknesses and temperatures. The results can be explained by established exponential trapping models.
Anti-Stokes Line in an Index-Guiding Photonic Crystal Fibre with Two Zero-Dispersion Wavelengths

An index-guiding photonic crystal fibre with a small hole in the core is fabricated. The simulated results show that the first higher order mode possesses two zero-dispersion wavelengths, and the phase-matching is possible in the anomalous dispersion regime between the two zero-dispersion wavelengths. Using 200 fs Ti: sapphire laser of 820, 830 and 840 nm, the anti-Stokes line around 530 nm can be generated efficiently. The maximum ratio of the anti-Stokes signal energy to the pump component in the output spectrum is estimated to be 1.03 and the conversion efficiency is above 50%.
An Approximate Analysis of Variance Test for Normality

Abstract This article presents a modification of the Shapiro-Wilk W statistic for testing normality which can be used with large samples. Shapiro and Wilk gave coefficients and percentage points for sample sizes up to 50. These coefficients required obtaining an approximation to the covariance matrix of the normal order statistics. The proposed test uses coefficients which depend only on the expected values of the normal order statistics which are generally available. Results of an empirical sampling study to compare the sensitivity of the test statistic to the W test statistic are briefly discussed.
A Unified Framework for Training, Mapping and Simulation of ReRAM-Based Convolutional Neural Network Acceleration

ReRAM-based neural network accelerators (RNAs) could outshine their digital counterparts in terms of computational efficiency and performance remarkably. However, some open software tool for broad architectural exploration and end-to-end evaluation are still missing. We present a simulation framework of RNA for CNN inference that encompasses a ReRAM-aware NN training tool, a CNN-oriented mapper and a micro-architecture simulator. Main characteristics of ReRAM and circuits are reflected by the configurable simulator, as well as by the customized training algorithm. The function of the simulator's core components is verified by the corresponding circuit simulation of a real chip design. This framework enables comprehensive architectural exploration and end-to-end evaluation, and it's preliminary version is available at https://github.com/CRAFT-THU/XB-Sim.
Lateral variance of implanted ions

A quadratic model is presented whereby the depth-dependent lateral variance of ions implanted into amorphous targets may be estimated from a knowledge of the first seven moments of the distribution. The authors compare their results, and those derived using a perturbation approach of Lorenz et al., (1989) against high resolution Monte-Carlo data.
Scoring Method and the Detection of Person Misfit in a Personality Assessment Context

The purpose of this research was to explore psycho metric issues pertinent to the application of an IRT based person-fit (response aberrancy) detection statistic in the personality measurement domain. Monte carlo data analyses were conducted to address issues regarding the l z person-fit statistic. The major issues explored were characteristics of the null distribution of l z and its power to identify nonfitting response patterns under different scoring strategies. There were two main results. First, the l z index null distribution was not well standardized when item parameters of personality scales were used; the l z null distribution variance was significantly less than the hypothesized value of 1.0 under several conditions. Second, the power of l z to detect response misfit was affected by the scoring method. Detection power was optimal when a biweight estimator of θ was used. Recommendations are made regarding proper implementation of person-fit statistics in personality measurement.
Brownian Motion Indexed by a Time Scale

In this article, we generalize Wiener's existence result for one-dimensional Brownian motion by constructing a suitable continuous stochastic process where the index set is a time scale. We construct a countable dense subset of a time scale and use it to prove a generalized version of the Kolmogorov–Čentsov theorem. As a corollary, we obtain a local Hölder-continuity result for the sample paths of generalized Brownian motion indexed by a time scale.