A Comparative Study of Amplitude and Timing Estimation in Experimental Particle Physics using Monte Carlo Simulation

Optimal detection of liquid ionization calorimeter signal in experimental particle physics is considered. A few linear and nonlinear approaches for amplitude and arrival time estimation based on the χ2 function are compared in simulation considering the noise sample correlation introduced by the analog pulse shaper. The estimation bias of the first-order approximation, a.k.a linear optimal filtering, is studied and contrasted to those of the second-order as well as the exhaustive search. A gradient-descent technique is presented as an alternative to the exhaustive search with significantly reduced search time and computation complexity. Results from various pulse shapers including the CR-RC2, CR-RC3, and CR2-RC2 are also compared.

无序体系的理论方法(Ⅰ)

本文综合评述了无序体系的理论方法,包括数值计算方法,平均格林函数求解方法。

Constraining the Parameterized Neutron Star Equation of State with Astronomical Observations

We utilize the phenomenologically parameterized piecewise polytropic equations of state to study various neutron star properties.We investigate the compliance of these equations of state with several astronomical observations.We also demonstrate that the theoretical estimates of the fractional moment of inertia cannot explain all the pulsar glitches observed.We model the crust as a solid spheroidal shell to calculate the fractional moment of inertia of fast-spinning neutron stars.We also show that the braking index obtained in a simple magnetic dipole radiation model with a varying moment of inertia deviates significantly from the observed data.Future developments in both theory and observations may allow us to use the fractional moment of inertia and braking index as observational constraints for neutron star equation of state.

The Influence of Benzophenone Substitution on the Physico-Chemical Characterizations of 8-HydroxyQuinoline NLO Single Crystals

Single crystals of 8-Hydroxyquinoline(8-HQ) and Benzophenone substituted 8-HydroxyQuinoline(B8-HQ) are grown by slow evaporation of acetone at room temperature. Coloured crystals of 8-HQ and B8-HQ with good optical quality of dimensions 54 × 3 × 1.5 mm3 and 27 × 3 × 1 mm3 are harvested. Single crystal X-ray diffractometer was utilized to measure the unit cell parameters and to confirm the crystal structure. The presence of various functional groups in the molecule was ascertained by FTIR spectral analysis. The cut-offwavelength of 8-HQ andB8-HQwas centered at 350 and 356 nm. The functional groups in the molecule are elucidated by 1H and 13C-NMR spectral analyses. Kurtz Perry test confirms the SHG in8-HQ andB8-HQ single crystals.

Cabibbo-Suppressed Non-leptonic Decays of ∧c and Final State Interaction

With the diquark structure of ∧c, we investigate the branching ratio of ∧c→nπ^+ and pπ^0. The results show that without considering the finM state interaction (FSI), the branching ratio of ∧c→pπ^0 is only of order 10^-6 whereas this ratio could reach 10^-4 and is at the same order as ∧c→nπ^+ if taking into account the FSI effects. Concrete values depend on phenomenologicM parameters adopted in the calculations. These branching ratios can be measured in the experiments to come.

Electric and Magnetic Properties of [(NCZF)_1-x(Na(ac.ac))_x] Nanocomposite

The pure spinel phase of Ni0.45Co0.2Zn0.35F2O4[NCZF] was prepared by co-precipitation method. The nanocomposite [(NCZF)1-x(Na(ac.ac))x] (x = 0%, 20%, 40%, 60%, 80%, 100%) was prepared by mixing two phases: ferrite phase and ferroelectric phase. The magnetic characters of compo-sites performed using vibrating sample magnitude (VSM) at room temper-ature with maximum applied field up to 2 kG. For smaller particle size 30.89 nm. The saturation magnetization Ms decreases linearly with increasing particle size. The effect of temperature on the electrical resistivity of the different composites samples was studied. It is noted that, the resistivity decreases with rising temperature to have a minimum value at ferroelectric transition temperature, above this value the resistivity increases. The dielectric constant increases with increasing temperature for all composites. The dielectric loss tan (δ) as a function of temperature sharply with temperature reached to maximum value at ferroelectric phase transition then decrease again.

Post-traumatic headache:A neurorehabilitation perspective(Part Ⅱ)

Musculoskeletal headache is classically characterized as a cap-like discomfort,but varies with the offending musculature. The sternoeleidomastoid is notorious for refer—ring pain retro or periorbitally.

Determination of Photon and Elementary Particles Rest Masses Using Maxwell’s Equations and Generalized Potential Dependent Special Relativity

The nature and origin of the photon and elementary rest masses are some of the challeng-ing problems that physics face. The approaches used to solve these problems are complex and time-consuming. Specifically, the photon rest mass pays attention to theoretical physi-cists. Many experimental works show that the photon rest mass is non zero. This problem can be solved using generalized potential dependent special relativity, which has been de-rived using simple arguments, and Maxwell’s equations, besides the conventional Einstein energy-momentum relation. The results obtained show that the rest mass of photons and elementary particles are strongly dependent on the vacuum energy and a universal con-stant. This result conforms with the models that predict time decaying vacuum energy as-sociated with production of smaller rest mass particles followed by larger masses. The two potential dependent mass expressions conform with the cosmological models that suggest the photon is generated first by assuming the universe consisting of total constant vacuum with decaying cosmological part and mass generating part. Using Maxwell’s equations, beside plank and De Broglie hypothesis together with special relativity energy-momentum relation the photon rest mass is estimated. It was shown that the photon rest mass is ex-tremely small compared to the electron mass.

A Simple Nonfused Ring Electron Acceptor with a Power Conversion Efficiency over 16%

By simplifying the r-bridge unit,a nonfused ring electron acceptor(NFREA)BM-2F was designed and synthesized with several high-yield steps.The specific molecular structure features of BM-2F are planar molecular backbone and out-of-plane side chain,which is favorable for charge transport and can suppress the over-aggregation.BM-2F based neat and blend films display obvious face-on molecular orientation.Specially,D18:BM-2F based blend film can form good bicontinuous interpenetrating network.More excitingly,a power conversion efficiency of 16.15%was achieved with D18:BM-2F based photovoltaic devices,which is the highest one based on NFREAs.Our researches manifest that NFREA is a promising direction for low-cost and high-performance organic solar cells.

Synergetic Alkoxy Side-Chain and Chlorine-Contained End Group Strategy toward High Performance Ultra-Narrow Bandgap Small Molecule Acceptors

Ultra-narrow bandgap(ultra-NBG)small molecule acceptors(SMAs)show great potential in organic solar cells(OSCs)due to the extended near-infrared(NIR)absorption.In this work,a synergetic alkoxy side-chain and chlorine-contained end group strategy is employed to achieve A-DA'D-A type ultra-NBG SMAs by introducing alkoxy chains with oxygen atom at the second position into the thiopheneβposition as well as replacing the F atoms with Cl atoms in the end group.As a result,the heptacyclic BZO-4F shows a redshifted absorption onset(960 nm)compared with Y11(932 nm)without oxygen atoms in the side chains.Then,the fluorinated end groups are substituted with the chlorinated ones to synthesize BZO-4Cl.The absorption onset of BZO-4Cl is further redshifted to 990 nm,corresponding to an optical ultra-NBG of 1.25 eV.When blending with the polymer donor PBDB-T,the binary devices based on PBDB-T:BZO-4F and PBDB-T:BZO-4Cl deliver power conversion efficiencies(PCEs)over 12%.Furthermore,ternary devices with the addition of BZ4F-O-1 into PBDB-T:BZO-4Cl system achieve the optimal PCE of 15.51%.This work proposes a synergetic alkoxy side-chain and chlorine-contained end group strategy to achieve A-DA'D-A type ultra-NBG SMAs,which is important for future molecular design.

Gauge invariant perturbations of general spherically symmetric spacetimes

In this paper,the gauge choices in general spherically symmetric spacetimes are explored.In particular,we construct the gauge invariant variables and the master equations for both the Detweiler easy gauge and the Regge-Wheeler gauge,respectively.The particular cases for l=0,1 are also investigated.Our results provide analytical calculations of metric perturbations in general spherically symmetric spacetimes,which can be applied to various cases,including the effective-one-body problem.A simple example is presented to show how the metric perturbation components are related to the source perturbation terms.

Amorphous phase stability of NbTiAlSiNx high-entropy films

In this study, high-entropy films with the compo- sition of NbTiA1SiNx were prepared by a reactive direct current （DC） magnetron sputtering technique, with different nitrogen flow rates （0, 4 and 8 ml.min^-1）. The microstructures and properties were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high-resolution transmission electron microscopy （HRTEM）, nano-indenter and spectrophotometer. All of the as-deposited NbTiA1SiNx films are shown to have an amorphous structure, and the films exhibit high thermal stability up to 700℃. The maximum hardness and modulus values of the films reach 20.5 GPa （4 ml.min-1） and 206.8 GPa （0 ml.min^-l）, respectively. The films exhibit high absorption of the solar energy in the wavelength of 0.3-2.5 pm, which indicates that NbTiA1SiNx nitride film is a potential candidate solar selective absorbing coating for high-temperature photo-thermal conversion in the concentrated solar power project.

Sign-reversed anomalous Nernst effect in the ferromagnetic Weyl-semimetal Fe_(3-δ)GeTe_(2): the role of Fe vacancies

Anomalous Nernst effect, as a thermal partner of anomalous Hall effect, is particularly sensitive to the Berry curvature anomaly near the Fermi level, and has been used to probe the topological nature of quantum materials. In this work, we report the observation of both effects in the ferromagnetic Weyl-semimetal Fe_(3-δ)GeTe_(2) with tunable Fe vacancies. With decreasing Fe vacancies,the anomalous Hall conductivity evolves as a function of the longitudinal conductivity from the hopping region to the region where the intrinsic Berry curvature contribution dominates. Concomitant evolutions in the anomalous Nernst signal and the anomalous off-diagonal thermoelectric coefficient are observed below the Curie temperature, displaying a unique sign change caused by the Fe vacancies. Combining these results with first-principles calculations, we argue that the Fe-vacancy concentration plays a unique role in simultaneously tuning the chemical potential and ferromagnetism, which in turn controls the Berry curvature contribution in this family of ferromagnetic topological semimetals.