Ultra-low thermal conductivity of roughened silicon nanowires:Role of phonon-surface bond order imperfection scattering

The ultra-low thermal conductivity of roughened silicon nanowires(SiNWs)can not be explained by the classical phonon-surface scattering mechanism.Although there have been several efforts at developing theories of phonon-surface scattering to interpret it,but the underlying reason is still debatable.We consider that the bond order loss and correlative bond hardening on the surface of roughened SiNWs will deeply influence the thermal transport because of their ultra-high surface-to-volume ratio.By combining this mechanism with the phonon Boltzmann transport equation,we explicate that the suppression of high-frequency phonons results in the obvious reduction of thermal conductivity of roughened SiNWs.Moreover,we verify that the roughness amplitude has more remarkable influence on thermal conductivity of SiNWs than the roughness correlation length,and the surface-to-volume ratio is a nearly universal gauge for thermal conductivity of roughened SiNWs.

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.

Advances of phononics in 2012-2022

Due to its great potential applications in thermal management,heat control,and quantum information,phononics has gained increasing attentions since the first publication in Rev.Mod.Phys.841045(2012).Many theoretical and experimental progresses have been achieved in the past decade.In this paper,we first give a critical review of the progress in thermal diodes and transistors,especially in classical regime.Then,we give a brief introduction to the new developing research directions such as topological phononics and quantum phononics.In the third part,we discuss the potential applications.Last but not least,we point out the outlook and challenges ahead.

Thermal conductivity of carbon nanotube superlattices:Comparative study with defective carbon nanotubes

We use molecular dynamics simulation to calculate the thermal conductivities of（5, 5） carbon nanotube superlattices（CNTSLs） and defective carbon nanotubes（DCNTs）, where CNTSLs and DCNTs have the same size. It is found that the thermal conductivity of DCNT is lower than that of CNTSL at the same concentration of Stone–Wales（SW） defects. We perform the analysis of heat current autocorrelation functions and observe the phonon coherent resonance in CNTSLs, but do not observe the same effect in DCNTs. The phonon vibrational eigen-mode analysis reveals that all modes of phonons are strongly localized by SW defects. The degree of localization of CNTSLs is lower than that of DCNTs, because the phonon coherent resonance results in the phonon tunneling effect in the longitudinal phonon mode. The results are helpful in understanding and tuning the thermal conductivity of carbon nanotubes by defect engineering.

Electronic Phase Separation in Iron Selenide(Li,Fe)OHFeSe Superconductor System

The phenomenon of phase separation into antiferromagnetic（AFM） and superconducting（SC） or normal-state regions has great implication for the origin of high-temperature（high-T_c） superconductivity. However, the occurrence of an intrinsic antiferromagnetism above the T_c of（Li,Fe）OHFe Se superconductor is questioned. Here we report a systematic study on a series of（Li,Fe）OHFe Se single crystal samples with T_c up to ～41 K. We observe an evident drop in the static magnetization at T_（afm） ～ 125 K, in some of the SC（T_c 38 K, cell parameter c■9.27 ？） and non-SC samples. We verify that this AFM signal is intrinsic to（Li,Fe）OHFe Se. Thus, our observations indicate mesoscopic-to-macroscopic coexistence of an AFM state with the normal（below T_（afm）） or SC（below T_c） state in（Li,Fe）OHFe Se. We explain such coexistence by electronic phase separation, similar to that in high-T_c cuprates and iron arsenides. However, such an AFM signal can be absent in some other samples of（Li,Fe）OHFe Se, particularly it is never observed in the SC samples of T_c 38 K, owing to a spatial scale of the phase separation too small for the macroscopic magnetic probe. For this case, we propose a microscopic electronic phase separation. The occurrence of two-dimensional AFM spin fluctuations below nearly the same temperature as T_（afm）, reported previously for a（Li,Fe）OHFe Se（T_c ～ 42 K） single crystal, suggests that the microscopic static phase separation reaches vanishing point in high T_c（Li,Fe）OHFe Se. A complete phase diagram is thus established. Our study provides key information of the underlying physics for high-T_c superconductivity.

Prospective study of light dark matter search with a newly proposed DarkSHINE experiment

Dark photons have been well motivated as strong candidates for dark force carriers and light dark matter in the sub-GeV mass range.Compared with collider experiments,fixed-target experiments provide a complementary approach to searching for dark photons,particularly in the lower mass range.We have studied the physics potential of the electron-on-target experiment based on the Shanghai SHINE facility,which provides 10 MHz single electron beam at 8 GeV energy.This analysis focuses on dark photons being produced via electron and nucleon interaction and then decays to dark matter candidates,which escape detection as missing momentum in the detector.This experiment takes advantage of using missing momentum to enhance signal versus background separation power.In this study,signal samples as a function of dark photon mass and an inclusive background sample with 2.5 billion events are simulated with GEANT4.For better background estimates,major rare background processes have also been simulated.This paper presents the experiment and detector design,signal and background simulations,analysis strategy,and the prospective study of the experiment sensitivity.With 9×10^(14) electron-on-target events(about three years running),this experiment is expected to rule out most of the sensitive regions predicted by popular dark photon models.

REVIEW OF PARTICLE PHYSICS

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on： Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews （and errata） are also available on the Particle Data Group website： http ：//pdg. lbl. gov.

A first-principles study of site occupancy and interfacial energetics of an H-doped TiAl-Ti_3 Al alloy

We investigate the site occupancy and the interfacial energetics of TiAl-Ti 3 Al binary-phase system with H using a first-principles method.H energetically prefers to occupy the Ti-rich octahedral interstitial site because H prefers to bond with Ti rather than with Al.The occupancy tendency of H in the binary phase TiAl-Ti 3 Al alloy from high to low is 2-Ti 3 Al to/2 interface and-TiAl,because the decrease of the Ti local concentration is in the same order.We demonstrate that H can largely affect the mechanical properties of the TiAl-Ti 3 Al system.On the one hand,H at the interface reduces the interface energy with the H 2 molecule as a reference,implying the TiAl/Ti 3 Al interface is stabilized.On the other hand,the ratio between the cleavage energy and the unstable stacking fault energy decreases after H-doping,indicating H will reduce the ductility of the TiAl/Ti 3 Al interface.Consequently,the mechanical property variation of TiAl alloy due to the presence of H not only depends on the amount of TiAl/Ti 3 Al interfaces but also is related to the H concentration in the alloy.

ACCELERATOR PHYSICS OF COLLIDERS

Revised August 2013 by M.J. Syphers （MSU） and F. Zimmermann （CERN）.29.1. Luminosity This article provides background for the High-Energy Collider Parameter Tables that follow. The number of events, Nexp, is the product of the cross section of interest,

STATUS OF HIGGS BOSON PHYSICS

Written November 2013 by M. Carena （Fermi National Accelerator Laboratory and the University of Chicago）, C. Grojean （ICREA at IFAE, Universitat Autbnoma de Barcelona）, M, Kado （Laboratoire de l＇Accelerateur Lineaire, LAL and CERN）, and V. Sharma （University of California San Diego）.

HIGHLIGHTS OF THE 2014 EDITION OF THE REVIEW OF PARTICLE PHYSICS

899 new papers with 3283 new measurements Over 330 papers from LHC experiments （ATLAS, CMS, and LHCb）.

The nonlinear effects of large amplitude ion acoustic wave in a collisional plasma

When plasma wave amplitude is large enough, some electrons are trapped in the trough of the wave. Because of wave-particle interaction electron distribution function is distorted seriously at the wave phase velocity V_φ=ω/k. Hasegawa discussed the large amplitude wave based on the assumption that the electron distribution function becomes flat in the trapped region. Krapchev studied the adiabatic theory of current generation by a coher ent, nonlinear, large amplitude travelling wave. But they neglected the dissipation effects. Xia discussed a new stochastic mechanism of current driven by a wave. He thought that the stochastic effect will appear when the wave amplitude is higher than a threshold.

Single Domain Temperature of FE Single Crystal

Near the FE phase transition temperature T_c, a ferroelectric crystal has very large pyroelectric coefficient p and may be used for energy converter as a heat engine. But there is a single domain temperature T_s below T_c. The single domain state of a ferroelectric crystal is steady only at temperature below T_s. Between T_s and T_c, macroscopic pyroelectric effect is irreversible since opposite domains are present. For triglycine sulphate (TGS), T_c=49℃ and T_s=33℃.

Correlativity of nucleosynthesis in low-mass AGB stars

In a self-consistent treatment, an LM-AGB TP model of HHe-burning and no-branch reaction passway for s-process from Fe-Bi with correlative reaction network from C-Ne is used to reproduce the enrichment of F, C and heavy elements in the surface of MS and S stars (with Tc). The growing of the core mass and the mass loss through steller winds are also considered. Comparisons between the computed correlation: {[F/O], C/O}; {[F/O], (s/Ti)} and that of the observations are then presented. It appears that fluorine and heavy elements can be synthesized where the nucleosynthesis events occur in a fit temperature range, and then are dredged up to the surface of the star. Because F production only occurs in a narrow temperature range, the synthesis events are sensitive to temperature. The observation of this case is discussed specially.

External control of qubit-photon interaction and multi-qubit reset in a dissipative quantum network

A quantum network is a promising quantum many-body system because of its tailored geometry and controllable interaction. Here,we propose an external control scheme for the qubit-photon interaction and multiqubit reset in a dissipative quantum network,which comprises superconducting circuit chains with microwave drives and filter-filter couplings. The traditional multiqubit reset of the quantum network requires physically disconnected qubits to prevent their entanglement. However, we use an original effect of dissipation, i.e., consuming the entanglement generated by qubits’ interaction, to achieve an external control of the multiqubit reset in an always-connected superconducting circuit. The reset time is independent of the number of qubits in the quantum network. Our proposal can tolerate considerable fluctuations in the system parameters and can be applicable to higherdimensional quantum networks.

Role of phase separation in nanocomposite indium-tin-oxide films for transparent thermoelectric applications

We report that oxygen vacancies have a profound impact on phase separation and thermoelectric properties of ITO films grown at room temperature.Oxygen vacancies in non-stoichiometric In1.8Sn0.2O2.5 films aided the formation of In-rich metallic clusters.It yields a high electrical conductivity s=1540 Scm1 and Seebeck coefficient|a|=27.2 mVK1,which resulted in the highest power factor(a2 s=113.8 mW m1 K2)but low optical transmission(Top-25%).An increase in oxygen partial pressure resulted in stochiometric In1.8Sn0.2O3 films which improved the optical transparency by 300%(Top-75.4%),but power factor was reduced by-85%due to a decrease in a and s.A decrease in a was due to the lack of energy filtering of charge carriers in the stoichiometric ITO film which did not have In-rich metallic clusters.XPS results showed that the valence band energy shifts with a change in oxygen partial pressure due to a decrease in carrier density,which implied a change in Fermi energy due to the reverse Moss-Burstein effect.Our results showed that phase separation can be obtained in nanocomposite ITO films by tuning their stoichiometry simply by varying the oxygen partial pressure during deposition of thermoelectric materials at low temperatures.

ELECTROWEAK MODEL AND CONSTRAINTS ON NEW PHYSICS

Revised November 2013 by J. Erler （U. Mexico） and A. Freit＆s （Pittsburgh U.）.10.1 Introduction 10.2 Renormalization and radiative corrections

ATOMIC AND NUCLEAR PROPERTIES OF MATERIALS

Table 6.1 Abridged from pdg. ibl.gov/AtomicNuclearProperties by D. E. Groom （2007）. See web pages for more detail about entries in this table including chemical formulae, and for several hundred other entries. Quantities in parentheses are for gases at 20℃ and 1 atm, and square brackets indicate evaluation at 0℃ and 1 atm. Boiling points are at 1 atm.