Miracle-dz/UniFAR-FTUs huggingface dataset:
Carrier lifetimes of >1 μs in Sn-Pb perovskites enable efficient all-perovskite tandem solar cells

Efficient all-perovskite tandem cells Organic-inorganic perovskite films can boost the output of conventional silicon solar cells in tandem geometries by utilizing more of the light at the blue end of the solar spectrum. Tandem cells that use only perovskite films have been less successful because of the lack of a suitable material with a low bandgap that can replace silicon. Tong et al. report that a mixed tin-lead organic-inorganic material containing a small fraction of guanidinium thiocyanate has a low bandgap, long charge-carrier lifetime, and efficiencies around 25%. Science, this issue p. 475 The addition of guanidinium thiocyanate improves the performance of mixed tin-lead perovskite solar cells. All-perovskite–based polycrystalline thin-film tandem solar cells have the potential to deliver efficiencies of >30%. However, the performance of all-perovskite–based tandem devices has been limited by the lack of high-efficiency, low–band gap tin-lead (Sn-Pb) mixed-perovskite solar cells (PSCs). We found that the addition of guanidinium thiocyanate (GuaSCN) resulted in marked improvements in the structural and optoelectronic properties of Sn-Pb mixed, low–band gap (~1.25 electron volt) perovskite films. The films have defect densities that are lower by a factor of 10, leading to carrier lifetimes of greater than 1 microsecond and diffusion lengths of 2.5 micrometers. These improved properties enable our demonstration of >20% efficient low–band gap PSCs. When combined with wider–band gap PSCs, we achieve 25% efficient four-terminal and 23.1% efficient two-terminal all-perovskite–based polycrystalline thin-film tandem solar cells.
Magnetoelectric thin film composites with interdigital electrodes

Magnetoelectric (ME) thin film composites on silicon cantilevers are fabricated using Pb(Zr0.52Ti0.45)O3 (PZT) films with interdigital transducer electrodes on the top side and FeCoSiB amorphous magnetostrictive thin films on the backside. These composites without any direct interface between the piezoelectric and magnetostrictive phase are superior to conventional plate capacitor-type thin film ME composites. A limit of detection of 2.6 pT/Hz1/2 at the mechanical resonance is determined which corresponds to an improvement of a factor of approximately 2.8 compared to the best plate type sensor using AlN as the piezoelectric phase and even a factor of approximately 4 for a PZT plate capacitor.
Long Range Interactions in Nanoscale Science.

Our understanding of the "long range" electrodynamic, electrostatic, and polar interactions that dominate the organization of small objects at separations beyond an interatomic bond length is reviewed. From this basic-forces perspective, a large number of systems are described from which one can learn about these organizing forces and how to modulate them. The many practical systems that harness these nanoscale forces are then surveyed. The survey reveals not only the promise of new devices and materials, but also the possibility of designing them more effectively.
Who Plays With Whom: Farrowing Environment Influences Isolation of Foster Piglets in Play

Cross fostering piglets is a common management practise in the pig industry to manage large and heterogeneous litters, whereby piglets are moved from their biological litter to be reared by another sow. At present research has focused on immediate survival consequences and time of cross fostering, with little attention given to positive aspects of welfare such as social affiliations and the potential for positive interactions for these piglets such as play behaviour. The focus of our study was purely observational to record behaviour of piglets reared in either impoverished (farrowing crates) or enriched neonatal environments (PigSAFE pens) where fostering was practised as part of normal husbandry routines to promote piglet survival. We employed social network analysis to understand more about the behaviour of foster piglets in these environments and their acceptance into their new litter. In line with previous work, piglets exposed to enriched neonatal farrowing pens demonstrated more play behaviour than piglets reared in farrowing crates. We showed that pen piglets received and initiated more play invitations (higher degree centrality) than piglets in crates. We also found effects of cross fostering irrespective of neonatal environment. Non-foster piglets received and initiated more play behaviours (higher degree centrality) 2–3 weeks post-farrowing compared to piglets fostered into the litter and as such, fostered piglets remained isolated from play for the first few weeks of life. However, our data suggests this may be mitigated by neonatal environment; foster piglets reared in pens were better connected (betweenness centrality) within their foster litter than those fostered in crates. Our findings highlight the importance of the neonatal environment and its potential influence on the isolation of cross-fostered piglets and suggest that rearing in enriched neonatal environments may help mitigate against social isolation in early life of cross-fostered piglets, having obvious immediate, and long-term consequences for piglet welfare and behaviour. We also highlight the importance and application of methodologies such as social network analysis, for gaining more insight and understanding about the sociality of animal behaviour and its potential for measuring indicators of positive welfare, thus highlighting its application for veterinary science and animal behaviour and welfare research.
The Effect of the Number of Phoneme Clusters on Speech Recognition

본 논문에서는 음성 인식의 효율을 높이기 위하여 음소 클러스터 개수의 효과에 대해 연구하였다. 이를 위하여 음소 클러스터 개수를 바꾸어 가면서 수정된 k-평균 군집 알고리듬을 사용하여 코우드북을 작성하였다. 그런 다음, 퍼지 벡터 양자화와 은닉 마코브 모델을 사용하여 음성인식 테스트를 수행하였다. 실험 결과 두 개의 영역이 구분되어 나타났다. 음소 클러스터 개수가 클 때 인식 성능은 대체로 그와 무관하지만, 개수가 작을 때에는 그 감소와 더불어 인식 오류율이 비선형적으로 증가하는 것으로 나타났다. 수치 해석적 계산으로부터, 이 비선형 영역은 멱승함수에 의해 모델링 될 수 있었다. 또한 300개의 고립단어 인식의 경우에, 166개의 음소클러스터가 최적의 수임을 보일 수 있었다. 이는 음소당 3개 정도의 변화에 해당하는 값이다.
Circuit modeling of quantum-well lasers for optoelectronic integrated circuits (ICs) including physical effect of deep-level traps

For the purposes of optoelectronic design, this paper presents a new and original small signal two-port circuit model of a quantum-well laser that has been developed from rate equations. This model is based on the physics of the spontaneous emission, stimulated emission, lightwave resonance, high-level injection, active-layer carrier degeneracy, and deep-level traps simultaneously. This model is compatible with general-purpose circuit analysis program (e.g., PSPICE) and is used to determine the frequency modulation bandwidth and the intensity modulation of the semiconductor laser. The results indicate that an increment in the density of the traps causes a decrease in both the amplitude of the output light and the bandwidth of the frequency response and an increase in the steady-state time.
Computation and visualization of spreading depression based on reaction-diffusion equation with recovery

Spreading depression (SD) shows as propagating suppression of electrical activity, which relates with migraine and focal cerebral ischaemia. The putative mechanism of SD is the reaction-diffusion hypothesis involving potassium ions. In part inspired by optical imaging of two SD waves collision, we aimed to show the merged and large wavefront but not annihilation during collision by experimental and computational study. This paper modified Reggia et al established bistable equation with recovery to compute and visualize SD. Firstly, the media tissue of SD was assumed as one-dimensional continuum. The Crank-Nicholson method was used to solve the modified equations with recovery term. Then, the computation results were extended to two-dimensional space by symmetry. One individual SD was visualized as a concentric wave initiating from the stimulation point. The mergence but not annihilation of two colliding waves of SD was demonstrated. In addition, the dynamics of SD depending on the parameters was studied and presented. The results allied SD with the emerging concepts of volume transmission. This work not only supplied a paradigm to compute and visualize SD but also became a tool to explore the mechanisms of SD.
Advanced scheme for high-yield laser driven nuclear reactions

The use of a low contrast nanosecond laser pulse with a relatively low intensity (3 × 1016 W cm−2) allowed the enhancing of the yield of induced nuclear reactions in advanced solid targets. In particular the ‘ultraclean’ proton–boron fusion reaction, producing energetic alpha particles without neutron generation, was chosen. A spatially well-defined layer of boron dopants in a hydrogen-enriched silicon substrate was used as a target. A combination of the specific target composition and the laser pulse temporal shape allowed the enhancing of the yield of alpha particles up to 109 per steradian. This result can be ascribed to the interaction of the long-laser pre-pulse with the target and to the optimal target geometry and composition.
Noise in solid-state microstructures: A new perspective on individual defects, interface states and low-frequency (1/ƒ) noise

Abstract In very small electronic devices the alternate capture and emission of carriers at an individual defect site generates discrete switching in the device resistance—referred to as a random telegraph signal (RTS). The study of RTSs has provided a powerful means of investigating the capture and emission kinetics of single defects, has demonstrated the defect origins of low-frequency (1/ƒ) noise in these devices, and has provided new insight into the nature of defects at the Si/SiO2 interface.
Robust estimation for non-homogeneous data and the selection of the optimal tuning parameter: the density power divergence approach

The density power divergence (DPD) measure, defined in terms of a single parameter α, has proved to be a popular tool in the area of robust estimation [1]. Recently, Ghosh and Basu [5] rigorously established the asymptotic properties of the MDPDEs in case of independent non-homogeneous observations. In this paper, we present an extensive numerical study to describe the performance of the method in the case of linear regression, the most common setup under the case of non-homogeneous data. In addition, we extend the existing methods for the selection of the optimal robustness tuning parameter from the case of independent and identically distributed (i.i.d.) data to the case of non-homogeneous observations. Proper selection of the tuning parameter is critical to the appropriateness of the resulting analysis. The selection of the optimal robustness tuning parameter is explored in the context of the linear regression problem with an extensive numerical study involving real and simulated data.
Effect of sample size on deformation in amorphous metals

Uniaxial compression tests were performed on micron-sized columns of amorphous PdSi to investigate the effect of sample size on deformation behavior. Cylindrical columns with diameters between 8μm and 140nm were fabricated from sputtered amorphous Pd77Si23 films on Si substrates by focused ion beam machining and compression tests were performed with a nanoindenter outfitted with a flat diamond punch. The columns exhibited elastic behavior until they yielded by either shear band formation on a plane at 50° to the loading axis or by homogenous deformation. Shear band formation occurred only in columns with diameters larger than 400nm. The change in deformation mechanism from shear band formation to homogeneous deformation with decreasing column size is attributed to a required critical strained volume for shear band formation.
Linear, nonadiabatic analysis of nonradial oscillations of massive near main sequence stars

The equations for linear, nonadiabatic, nonradial oscillations have been solved for models with 7 M/sub sun/, 12 M/sub sun/, and 20 M/sub sun/ in the core-hydrogen burning and hydrogen exhaustion phases. Although the nonadiabatic periods are essentially the same as those of the corresponding adiabatic ones for those models investigated, the e-folding times for the oscillation amplitude are considerably different from the results of a quasi-adiabatic analysis, in particular for f and p modes. All the modes investigated are stable. However, the opacity bump near the He/sup +/ ionization zone has a destabilizing influence on nonradial modes in the 7 M/sub sun/ models about as strong as on purely radial oscillations. The effective temperatures of the 12 M/sub sun/ and 20 M/sub sun/ models are too high for the opacity bump mehcanism to be effective as a destabilizing mechanism for nonradial modes. For the g/sup +/ modes another driving zone exists in the intermediate-to-high temperature region. This driving zone's effect on stability is larger than the destabilizing effect of the nuclear reactions of zero-age main-sequence models. The phase lag of maximum luminosity behind minimum radius is small except for relatively high order g/sup +/ modes, for which the maximum luminositymore » and the maximum temperature occur near the phase of maximum radius because of the dominant effect of horizontal motions. ''Avoided crossing'' of the modes in evolved models is also discussed. « less
Numerical calculation of image motion and vibration modulation transfer functions: a new method

A new method of numerical calculation of MTF is presented here for image motion in one- dimension. The method is applicable in principle to any type of motion and can be expanded to two-dimensional motion. It is applied here to uniform velocity motion and to sinusoidal vibrations. Comparison to known analytical methods is made where possible, and agreement is excellent. This supports its implementation to any kind of random motion, particularly where no unique analytical MTF is possible.
Application of algebraic graph descriptors for clustering of real-world structures

We propose several vector graph descriptors created on the basis of vertex rank measures such as PageRank, Hubs and Authorities or Betweenness Centrality. The descriptors are used for clustering artificial and real-world data. We present the comparison of descriptors with the use of criteria such as computational complexity, size and quality of clustering. The experiments were performed mainly on the sets of aerial photos transformed to graphs with the use of Harris corner detection and Delaunay triangulation. The results show that the introduced pattern vectors can be a lower dimensional, less computationally expensive and graph size independent alternative for spectral descriptors, such as defined by Wilson, Hancock and Luo in [1].
Underlying liver disease and advanced stage liver cancer are associated with elevated neutrophil-lymphocyte ratio

Background/Aims Inflammation-based scores, such as the neutrophil-to-lymphocyte ratio (NLR), have been associated with prognosis in hepatocellular carcinoma (HCC); but variable cut-off values and potential lack of specificity have limited the utility of NLR. This study evaluates NLR in a large cohort of HCC patients. Methods We retrospectively reviewed 789 HCC cases (1993–2017) for demographics, tumor characteristics, treatment, and survival. NLR was stratified into NLR ≥1.5 and NLR ≥3 and analyzed for correlation with American Joint Committee on Cancer (AJCC) and Barcelona Clinic Liver Cancer (BCLC) stages. In 235 patients who underwent liver resection, survival and recurrence were evaluated by NLR. Results In 789 HCC cases, mean NLR was increased with advanced AJCC and BCLC stages. Hepatitis C patients were less likely to have NLR ≥1.5 and ≥3. Non-alcoholic steatohepatitis patients were more likely to have NLR ≥3. Patients with tumor size >5 cm, rupture, or macrovascular invasion were more likely to have NLR ≥3. In patients treated with resection, NLR ≥3 predicted early recurrence (odds ratio [OR] 4.14, P<0.01) and overall recurrence (OR 4.05, P<0.01). Mean NLR was 4.30 in those with recurrence and 2.75 in those without recurrence. Patients with NLR ≥3 showed significantly worse survival compared to those with NLR <3 (P<0.01 by log-rank test). Conclusions Elevated NLR is associated with advanced cancer stage and aggressive tumor characteristics, such as large size, rupture, and invasion. NLR ≥3 was associated with early and overall recurrence after resection but varied with etiology. NLR may be a useful biomarker in predicting recurrence for HCC patients undergoing curative resection, but further studies are required to elucidate the effect of disease etiology.
Analysis of a continuous-time proportional hazard model using discrete duration data

Many economic duration variables are often available only up to intervals, and not up to exact points. However, continuous time duration models are conceptually superior to discrete ones. Hence, in duration analyses, one faces a situation with discrete data and a continuous model. This paper discusses (i) the asymptotic bias of a conventional approximation procedure in which a discrete duration is treated as an exact observation; and (ii) the efficiency of a correct maximum likelihood estimator which appropriately accounts for the discrete nature of the data.
Meshless approach to shape optimization of linear thermoelastic solids

This paper presents a formulation for shape optimization in thermoelasticity using a meshless method, namely the element‐free Galerkin method. Two examples are treated in detail and comparisons with previously published finite element analysis results demonstrate the excellent opportunities the EFG offers for solving these types of problems. Smoother stresses, no remeshing, and better accuracy than finite element solutions, permit answers to shape optimization problems in thermoelasticity that are practically unattainable with the classical FEM without remeshing. For the thermal fin example, the EFG finds finger shapes that are missed by the FEM analysis, and the objective value is greatly improved compared to the FEM solution. A study of the influence of the number of design parameters is performed and it is observed that the EFG can give better results with a smaller number of design parameters than is possible with traditional methods. Copyright © 2001 John Wiley & Sons, Ltd.
Meteor showers associated with 2003EH1

Using the Everhart RADAU19 numerical integration method, the orbital evolution of the near-Earth asteroid 2003EH 1 is investigated. This asteroid belongs to the Amor group and is moving on a comet-like orbit. The integrations are performed over one cycle of variation of the perihelion argument co. Over such a cycle, the orbit intersect that of the Earth at eight different values of ω. The orbital parameters are different at each of these intersections and so a meteoroid stream surrounding such an orbit can produce eight different meteor showers, one at each crossing. The geocentric radiants and velocities of the eight theoretical meteor showers associated with these crossing points are determined. Using published data, observed meteor showers are identified with each of the theoretically predicted showers. The character of the orbit and the existence of observed meteor showers associated with 2003EH1 confirm the supposition that this object is an extinct comet.
Two-Equation k-s Turbulence Model: Application to a Supersonic Base Flow

Base e ows are an important subject of theoretical studies due to the determinant role of the rear part of projectiles, missiles, or launchers in their e ight capabilities. The problem of accurately predicting the aerothermal e elds in which they are embedded is still not satisfactorily solved by current theoretical methods. However, such e ows are very useful test cases for improving turbulence modeling because they incorporate nearly all of the fundamental problems that can be encountered in supersonic turbulent e ows submitted to strong viscous interactions. Axisymmetriccone gurationsareappreciableforperforming numerousparametricalstudiesofmodelsdueto their rigorous two dimensionality. In this framework, a theoretical examination of the k‐! model is performed, and its principal distinguishing characteristics with respect to k‐" models are used to establish a k‐ae model whosesecond variable has a simple physical interpretation. A closeexamination of the predictivecapabilities of thesethree types of models is done in comparison with the well documented and largely accepted database from the experiments of Herrin and Dutton (Herrin, J. L., and Dutton, J. C., “ Supersonic Base Flow Experiments in the Near Wake of a Cylindrical Afterbody,” AIAA Paper 93-2924, July 1993 ). In particular, the evolution of the e uctuating quantities predicted by the models in separated e ow are given in detail. The results obtained prove that the simulation of separated e ows with two-equation turbulence models is still promising in the framework of Reynolds averaged Navier‐Stokes calculations.
A diagnostic for selecting the threshold in extreme value analysis

A new approach is suggested for choosing the threshold when fitting the Hill estimator of a tail exponent to extreme value data. Our method is based on an easily computed diagnostic, which in turn is founded directly on the Hill estimator itself, ‘symmetrized’ to remove the effect of the tail exponent but designed to emphasize biases in estimates of that exponent. The attractions of the method are its accuracy, its simplicity and the generality with which it applies. This generality implies that the technique has somewhat different goals from more conventional approaches, which are designed to accommodate the minor component of a postulated two‐component Pareto mixture. Our approach does not rely on the second component being Pareto distributed. Nevertheless, in the conventional setting it performs competitively with recently proposed methods, and in more general cases it achieves optimal rates of convergence. A by‐product of our development is a very simple and practicable exponential approximation to the distribution of the Hill estimator under departures from the Pareto distribution.
The Poisson Birnbaum–Saunders model with long-term survivors

In this paper, we propose a cure rate survival model by assuming that the number of competing causes of the event of interest follows the Poisson distribution and the time to event has the Birnbaum–Saunders (BS) distribution. We define the Poisson BS distribution and provide two useful representations for its density function which facilitate to obtain some mathematical properties. Two closed-form expressions for the moments of the new distribution are given. We estimate the parameters of the model with cure rate using maximum likelihood. For different parameter settings, sample sizes and censoring percentages, several simulations are performed. We derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes and present some ways to perform a global influence study. We analyse a real data set from the medical area.
Collisional removal of H I from the inner disks of Virgo Cluster galaxies

There is sufficient observational evidence to show that many Virgo Cluster spirals are H I deficient in their inner disks (in addition to being H I deficient globally, as previously established). It is shown here that collisions between galaxies in a cluster can lead to the removal of H I gas from these galaxies while leaving the H2 gas, undisturbed. This follows directly from the application of the Spitzer-Baade collisional gas removal mechanism to galaxies consisting of stars and a two-component ISM consisting of H I and H2, with H I having the largest filling factor. This can account for both the observed H I deficiency in the inner regions and the normal H2 content of these galaxies. The frequency of galaxy collisions in the Virgo Cluster is shown to be large enough to make collisional gas removal a viable mechanism. 46 refs.