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We explore the chemodynamical properties of the Galaxy in the azimuthal velocity V ϕ and metallicity [Fe/H] space using red giant stars from Gaia Data Release 3. The row-normalized V ϕ –[Fe/H] maps form a coherent sequence from the bulge to the outer disk, clearly revealing the thin/thick disk and the Splash. The metal-rich stars display bar-like kinematics, while the metal-poor stars show dispersion-dominated kinematics. The intermediate-metallicity population (−1 < [Fe/H]< − 0.4) can be separated into two populations, one that is bar-like, i.e., dynamically cold ( σ V R ∼ 80 km s−1) and fast-rotating (V ϕ ≳ 100 km s−1), and the Splash, which is dynamically hot ( σ V R ∼ 110 km s−1) and slow-rotating (V ϕ ≲ 100 km s−1). We compare the observations in the bulge region with an Auriga simulation where the last major merger event occurred ∼10 Gyr ago: only stars born around the time of the merger reveal a Splash-like feature in the V ϕ –[Fe/H] space, suggesting that the Splash is likely merger-induced, predominantly made up of heated disk stars and the starburst associated with the last major merger. Since the Splash formed from the proto-disk, its lower metallicity limit coincides with that of the thick disk. The bar formed later from the dynamically hot disk with [Fe/H] > − 1 dex, with the Splash not participating in the bar formation and growth. Moreover, with a set of isolated evolving N -body disk simulations, we confirm that a nonrotating classical bulge can be spun up by the bar and develop cylindrical rotation, consistent with the observations for the metal-poor stars. [ABSTRACT FROM AUTHOR]

A highly-stable and effective Er-doped random fiber laser (RFL) is proposed and experimentally demonstrated based on external optical injection locking technology. By adjusting the optical injected wavelength, the lasing wavelength can be selected precisely and emitted separately within the spectral bandwidth of 1555.5 nm to 1563.5 nm. The wavelength and output power fluctuation are less than 0.004% and 2.9%, respectively, indicating that optical injection locking of the RFL is quite stable over a long time. The optical injection locking technology is used in the half-open cavity incoherent RFL systems based on the random distributed Rayleigh scattering scheme, which provides an effective method to control or select the wavelength emission with high stability in a RFL. [ABSTRACT FROM AUTHOR]

To address the problem that it is difficult to detect an intermediate frequency (IF) signal at the receiving end of a communication system under extremely low signal-to-noise ratio (SNR) conditions, we propose a stochastic resonance (SR)-enhanced sine-signal detection method based on the sign function. By analyzing the SR mechanism of the sine signal and combining it with the characteristics of a dual-sequence frequency-hopping (DSFH) receiver, a periodic stationary solution of the Fokker–Planck equation (FPE) with a time parameter is obtained. The extreme point of the sine signal is selected as the decision time, and the force law of the electromagnetic particles is analyzed. A receiving structure based on the sign function is proposed to maximize the output difference of the system, and the value condition of the sign function is determined. In order to further improve the detection performance, in combination with the central-limit theorem, the sampling points are averaged N times, and the signal-detection problem is transformed into a hypothesis-testing problem under a Gaussian distribution. The theoretical analysis and simulation experiment results confirm that when N is 100 and the SNR is greater than 20 dB, the bit-error ratio (BER) is less than 1.5 × 10−2 under conditions in which the signal conforms to the optimal SR parameters. [ABSTRACT FROM AUTHOR]

In this paper, we collect a sample of stars observed both in LAMOST and Gaia, which have colors implying a temperature hotter than 7000 K. We train a machine-learning algorithm on LAMOST spectroscopic data which has been tagged with stellar classifications and metallicities, and use this machine to construct a catalog of blue horizontal branch stars (BHBs), together with metallicity information. Another machine is trained using Gaia parallaxes to predict absolute magnitudes for these stars. The final catalog of 13,693 BHBs is thought to be about 86% pure, with σ[Fe/H] ∼ 0.35 dex, and σG ∼ 0.31 mag. These values are confirmed via comparison to globular clusters, although a covariance error seems to affect our magnitude and abundance estimates. We analyze a subset of this catalog in the Galactic Halo. We find that BHB populations in the outer halo appear redder, which could imply a younger population, and that the metallicity gradient is relatively flat around [Fe/H] = −1.9 dex over our sample footprint. We find that our metal-rich BHB stars are on more radial velocity dispersion-dominated orbits (β ∼ 0.70) at all radii than our metal-poor BHB stars (β ∼ 0.62). [ABSTRACT FROM AUTHOR]

By combining the Large Sky Area Multi-object Fiber Spectroscopic Telescope and Gaia data, we investigate the vertical phase mixing across the Galactic disk. Our results confirm the existence of phase space snail shells (or phase spirals) from 6–12 kpc. We find that grouping stars by the guiding radius (Rg), instead of the present radius (R), further enhances the snail shell signal in the following aspects: (1) clarity of the snail shell shape is increased; (2) more wraps of the snail shell can be seen; (3) the phase spaces are less affected by the lack of stars closer to the disk midplane due to extinction; and (4) the phase space snail shell is amplified in greater radial ranges. Compared to the R-based snail shell, the quantitatively measured shapes are similar, except that the Rg-based snail shells show more wraps with a better contrast. These lines of evidence lead to the conclusion that the guiding radius (angular momentum) is a fundamental parameter tracing the phase space snail shell across the Galactic disk. Results of our test particle simulations with impulse approximation verify that particles grouped according to Rg reveal well-defined and sharper snail shell features. By comparing the radial profiles of the snail shell pitch angle between the observation and simulation, the external perturbation can be constrained to ∼500−700 Myr ago. For future vertical phase mixing study, it is recommended to use the guiding radius with additional constraints on orbital hotness (ellipticity) to improve the clarity of the phase snail. [ABSTRACT FROM AUTHOR]

We revisit the stellar velocity distribution in the Galactic bulge/bar region with Apache Point Observatory Galactic Evolution Experiment DR16 and Gaia DR2, focusing in particular on the possible high-velocity (HV) peaks and their physical origin. We fit the velocity distributions with two different models, namely with Gauss–Hermite polynomials and Gaussian mixture models (GMMs). The result of the fit using Gauss–Hermite polynomials reveals a positive correlation between the mean velocity () and the "skewness" (h3) of the velocity distribution, possibly caused by the Galactic bar. The n = 2 GMM fitting reveals a symmetric longitudinal trend of ∣μ2∣ and σ2 (the mean velocity and the standard deviation of the secondary component), which is inconsistent with the x2 orbital family predictions. Cold secondary peaks could be seen at ∣l∣ ∼ 6°. However, with the additional tangential information from Gaia, we find that the HV stars in the bulge show similar patterns in the radial–tangential velocity distribution (VR–VT), regardless of the existence of a distinct cold HV peak. The observed VR–VT (or VGSR–μl) distributions are consistent with the predictions of a simple Milky Way bar model. The chemical abundances and ages inferred from ASPCAP and CANNON suggest that the HV stars in the bulge/bar are generally as old as, if not older than, the other stars in the bulge/bar region. [ABSTRACT FROM AUTHOR]

A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS2 transistors. It is found that the carrier mobility of the transistor after the sulfur treatment on the MoS2 channel is greatly enhanced due to the reduction of the sulfur vacancies during vulcanization of MoS2. Furthermore, as compared to those transistors with HfO2 and SiO2 as the gate dielectric, the Al2O3-gate dielectric MoS2 FET shows a better electrical performance after the sulfur treatment, with a lowered subthreshold swing of 179.4 mV/dec, an increased on/off ratio of 2.11×106, and an enhanced carrier mobility of 64.74 cm2/V⋅s (about twice increase relative to the non-treated MoS2 transistor with SiO2 as the gate dielectric). These are mainly attributed to the fact that a suitable k-value gate dielectric can produce a dominant dielectric-screening effect overwhelming the phonon scattering, increasing the carrier mobility, while a larger k-value gate dielectric will enhance the phonon scattering to counteract the dielectric-screening effect, reducing the carrier mobility. [ABSTRACT FROM AUTHOR]

The initial orbits of infalling subhalos largely determine the subsequent evolution of the subhalos and satellite galaxies therein and shed light on the assembly of their hosts. Using a large set of cosmological simulations of various resolutions, we quantify the orbital distribution of subhalos at infall time and its mass and redshift dependence in a large dynamic range. We further provide a unified and accurate model validated across cosmic time, which can serve as the initial condition for semianalytic models. We find that the infall velocity v follows a nearly universal distribution peaked near the host virial velocity Vh for any subhalo mass or redshift, while the infall orbit is most radially biased when v ∼ Vh. Moreover, subhalos that have a higher host mass or a higher sub-to-host ratio tend to move along a more radial direction with a relatively smaller angular momentum than their low host mass or low sub-to-host ratio counterparts, though they share the same normalized orbital energy. These relations are nearly independent of the redshift when using the density peak height as the proxy for host halo mass. The above trends are consistent with the scenario where the dynamical environment is relatively colder for more massive structures because their own gravity is more likely to dominate the local potentials. Based on this understanding, the more massive or isolated halos are expected to have higher velocity anisotropy. [ABSTRACT FROM AUTHOR]

We estimate the Milky Way (MW) halo properties using satellite kinematic data including the latest measurements from Gaia DR2. With a simulation-based 6D phase-space distribution function (DF) of satellite kinematics, we can infer halo properties efficiently and without bias, and handle the selection function and measurement errors rigorously in the Bayesian framework. Applying our DF from the EAGLE simulation to 28 satellites, we obtain an MW halo mass of and a concentration of with the prior based on the M–c relation. The inferred mass profile is consistent with previous measurements but with better precision and reliability due to the improved methodology and data. Potential improvement is illustrated by combining satellite data and stellar rotation curves. Using our EAGLE DF and best-fit MW potential, we provide much more precise estimates of the kinematics for those satellites with uncertain measurements. Compared to the EAGLE DF, which matches the observed satellite kinematics very well, the DF from the semi-analytical model based on the dark-matter-only simulation Millennium II (SAM-MII) over-represents satellites with small radii and velocities. We attribute this difference to less disruption of satellites with small pericenter distances in the SAM-MII simulation. By varying the disruption rate of such satellites in this simulation, we estimate a ∼5% scatter in the inferred MW halo mass among hydrodynamics-based simulations. [ABSTRACT FROM AUTHOR]

We propose a versatile and accurate method to estimate the halo mass and concentration from the kinematics of satellite galaxies. We construct the 6D phase-space distribution function of satellites from a cosmological simulation based on the similarity of internal dynamics for different halos. Within the Bayesian statistical framework, not only can we efficiently infer the halo mass and concentration, we can also treat various observational effects, including the selection function, incomplete data, and measurement errors, in a rigorous and straightforward manner. Through tests with mock samples, we show that our method is valid and accurate, as well as more precise than pure steady-state methods. It can constrain the halo mass to within ∼20% using only 20 tracers and has a small intrinsic uncertainty of ∼10%. In addition to the clear application to the Milky Way and similar galaxies, our method can be extended to galaxy groups or clusters. [ABSTRACT FROM AUTHOR]

The galaxy is found to be in disequilibrium based on recent findings of the north/south (N/S) asymmetry and the phase mixing signatures, such as a phase spiral (snail) structure in the vertical phase space (z âˆ' V z ). We show that the N/S asymmetry in a tracer population of dwarfs may be quantitatively modeled with a simple phase snail model superimposed on a smooth equilibrium background. As the phase snail intersects with the z -axis, the number density is enhanced, and the velocity dispersion (σ z ) is decreased relative to the other side of the Galactic plane. Fitting only to the observed asymmetric N/S σ z profiles, we obtain reasonable parameters for the phase-space snail and the potential utilized in modeling the background, despite the complex dependence of the model on the potential parameters and the significant selection effects of the data. Both the snail shape and the N/S number density difference given by our best-fit model are consistent with previous observations. The equilibrium background implies a local dark matter density of 0.0151 âˆ' 0.0051 + 0.0050 M ⊙ pcâˆ'3. The vertical bulk motion of our model is similar to the observation, but with a ∼1.2 km sâˆ'1 shift. Our work demonstrates the strong correlation between the phase-space snail and the N/S asymmetry. Future observational constraints will facilitate more comprehensive snail models to unravel the Milky Way potential and the perturbation history encoded in the snail feature. [ABSTRACT FROM AUTHOR]

As promising materials, alloy-type anode materials have been intensively investigated in both academia and industry. To release huge volume expansion during alloying/dealloying process, they are usually doped with transition metals. However, the electrochemical role of transition metals has not been fully understood. Here, pure Sn3Fe films were deposited by sputtering, and the electrochemical mechanism was systematically investigated by operando magnetometry. We confirmed that Fe particles liberated by Li insertion recombine partially with Sn during the delithiation, while the stepwise increase in magnetization with the cycles demonstrates growth of Fe nanoparticles. In addition, we also found an unconventional increase of magnetization in the charging process, which can be attributed to the space charge storage at the interface of Fe/Li x Sn. These critical findings pave the way for the mechanism understanding and development of high-performance Sn based alloy electrode materials. [ABSTRACT FROM AUTHOR]

The Lie symmetries and conserved quantities of a two-dimensional nonlinear diffusion equation of concentration are considered. Based on the invariance of the two-dimensional nonlinear diffusion equation of concentration under the infinitesimal transformation with respect to the generalized coordinates and time, the determining equations of Lie symmetries are presented. The Lie groups of transformation and infinitesimal generators of this equation are obtained. The conserved quantities associated with the nonlinear diffusion equation of concentration are derived by integrating the characteristic equations. Also, the solutions of the two-dimensional nonlinear diffusion equation of concentration can be obtained. [ABSTRACT FROM AUTHOR]

The Lie group theoretical method is used to study the equations describing materials with competing quadratic and cubic nonlinearities. The equations share some of the nice properties of soliton equations. From the elliptic functions expansion method, we obtain large families of analytical solutions, in special cases, we have the periodic, kink and solitary solutions of the equations. Furthermore, we investigate the stability of these solutions under the perturbation of amplitude noises by numerical simulation. [ABSTRACT FROM AUTHOR]

Considering that capillary force is one of the most important forces between nanoparticles and atomic force microscope (AFM) tips in ambient atmosphere, we develop an analytic approach on the capillary force between an AFM tip and a nanoparticle. The results show that the capillary forces are considerably affected by the geometry of the AFM tip, the humidity of the environment, the vertical distance between the AFM tip and the nanoparticle, as well as the contact angles of the meniscus with an AFM tip and a nanoparticle. It is found that the sharper the AFM tip, the smaller the capillary force. The analyses and results are expected to be helpful for the quantitative imaging and manipulating of nanoparticles by AFMs. [ABSTRACT FROM AUTHOR]

The black hole candidate system SLX 1746–331 was back to business in 2023, after a long silence of roughly 13 years. An outburst was observed thoroughly by Insight-HXMT and NICER. The outburst is characterized by spectral dominance of the soft state, where the joint Insight-HXMT and NICER spectral analysis shows the temperature dependence of the disk flux follows T in 3.98 , and thus suggests that the inner disk reaches its innermost stable circular orbit during almost the entire outburst. By assuming 0.3 L Edd for the peak flux and an inclination angle of zero degrees, the lower limit of the compact object hosted in this system is estimated as 3.28 ± 2.14 M ⊙. We also look into the relation between the disk temperature and disk flux for a sample of black hole systems, and by taking the disk temperature derived in the outburst of SLX 1746–331, such a relation results in a mass estimation of 5.2 ± 4.5 M ⊙. Finally, the spin of the compact object is constrained to be larger than 0.8 with the spectral model KERRBB. [ABSTRACT FROM AUTHOR]

Spatial characteristics of Thomson scattering spectra are studied for an electron moving in the circularly polarized laser field in the presence of a strong uniform magnetic field. The results show that the angular distributions of the spectra with respect to the azimuthal and polar angles exhibit different symmetries, respectively, which depend on the fields and electron parameters sensitively and significantly. Moreover, for relatively large parameters such as high laser intensity, high magnetic resonance parameter as well as large initial momentum of electron, the two lobes in spectra tend to the laser-propagating direction so that the radiation can be collimated in the forward direction. Furthermore, an important finding is that by choosing the appropriate fields and initial momentum of electron, the high frequency part of the Thomson scattering spectra can reach the frequency range of soft x-ray, in which a high radiation power per solid angle as ∼1011 a.u. can be obtained. [ABSTRACT FROM AUTHOR]

The binary properties of open clusters place crucial constraints on star formation theory and clusters' dynamical evolution. We develop a comprehensive approach that models the color–magnitude diagram (CMD) of the cluster members as a mixture of single stars and photometric unresolved binaries. This method enables us to infer the binary properties, including the binary fraction fb and binary mass ratio distribution index γq when a power law is assumed, with high accuracy and precision, which was unfeasible in conventional methods. We employ a modified Gaussian process to determine the main-sequence ridgeline and its scatter from the observed CMD as model input. As a first example, we apply the method to the open cluster NGC 3532 with the Gaia DR2 photometry. For the cluster members within a magnitude range corresponding to FGK dwarfs, we obtain fb = 0.267 ± 0.019 and γq = −0.10 ± 0.22 for binaries with mass ratio q > 0.2. The fb value is consistent with the previous work on NGC 3532 and smaller than that of field stars. The close-to-zero γq indicates that the mass ratios of binaries follow a nearly uniform distribution. For the first time, we unveil that the stars with smaller mass or in the inner region tend to have lower fb and a more positive value of γq due to the lack of low mass ratio binaries. The clear dependences of binary properties on mass and radius are most likely caused by the internal dynamics. In this scheme, binaries with smaller primary mass or lower mass ratio have smaller binding energy; hence, they are more vulnerable to dynamical disruption, especially in the inner region where stars interact more frequently. [ABSTRACT FROM AUTHOR]

In the global climate system, the polar regions are sensitive indicators of climate change, in which sea ice plays an important role. Satellite remote sensing is a significant tool for monitoring sea ice. The use of synthetic aperture radar (SAR) images to distinguish sea ice from sea water is one of the current research hotspots in this topic. To distinguish sea ice from the open sea, the polarization ratio characteristics of sea ice and sea water are studied for L-band and C-band radars, based on an electromagnetic scattering model of sea ice derived from the integral equation method (IEM) and the radiative transfer (RT) model. Numerical experiments are carried out based on the model and the results are given as follows. For L-band, the polarization ratio for sea water depends only on the incident angle, while the polarization ratio for sea ice is related to the incident angle and the ice thickness. For C-band, the sea water polarization ratio is influenced by the incident angle and the root mean square (RMS) height of the sea surface. For C-band, for small to medium incident angles, the polarization ratio for bare sea ice is mainly determined by the incident angle and ice thickness. When the incident angle increases, the RMS height will also affect the polarization ratio for bare sea ice. If snow covers the sea ice, then the polarization ratio for sea ice decreases and is affected by the RMS height of snow surface, snow thickness, volume fraction and the radius of scatterers. The results show that the sea ice and the open sea can be distinguished by using either L-band or C-band radar according to their polarization ratio difference. However, the ability of L-band to make this differentiation is higher than that of C-band. [ABSTRACT FROM AUTHOR]

In this study, we designed and fabricated optical materials consisting of alternating ITO and Ag layers. This approach is considered to be a promising way to obtain a light-weight, ultrathin and transparent shielding medium, which not only transmits visible light but also inhibits the transmission of microwaves, despite the fact that the total thickness of the Ag film is much larger than the skin depth in the visible range and less than that in the microwave region. Theoretical results suggest that a high dielectric/metal thickness ratio can enhance the broadband and improve the transmittance in the optical range. Accordingly, the central wavelength was found to be red-shifted with increasing dielectric/metal thickness ratio. A physical mechanism behind the controlling transmission of visible light is also proposed. Meanwhile, the electromagnetic shielding effectiveness of the prepared structures was found to exceed 40 dB in the range from 0.1 GHz to 18 GHz, even reaching up to 70 dB at 0.1 GHz, which is far higher than that of a single ITO film of the same thickness. [ABSTRACT FROM AUTHOR]

We investigate the localization of a five-dimensional vector field on a pure geometrical thick brane. By introducing two types of interactions between the vector field and the background scalar field, we obtain a typical volcano potential for the first type of coupling and a Pöschl–Teller potential for the second one. These two types of couplings guarantee that the vector zero mode can be localized on the pure geometrical thick brane under certain conditions. [ABSTRACT FROM AUTHOR]

The experimental Compton profile of the propane molecule is measured at an incident photon energy of 20 keV based on the third generation synchrotron radiation, and the statistical accuracy of 0.2% is achieved near pz = 0. The calculated Compton profile by the density functional theory with aug-cc-pVTZ basis set reproduces the experimental observation very well. The joint experimental and theoretical investigation provides the benchmark data of the electronic structure of propane. [ABSTRACT FROM AUTHOR]

The explicit solutions to both the Oldroyd-B model with an infinite Weissenberg number and the coupled Navier-Stokes/phase-field system are constructed by the method of separation of variables. It is found that the solutions blow up in finite time. [ABSTRACT FROM AUTHOR]

We obtain a new type of conserved quantity of Mei symmetry for the motion of mechanico-electrical coupling dynamical systems under the infinitesimal transformations. A criterion of Mei symmetry for the mechanico-electrical coupling dynamical systems is given. Simultaneously, the condition of existence of the new conserved quantity of Mei symmetry for mechanico--electrical coupling dynamical systems is obtained. Finally, an example is given to illustrate the application of the results. [ABSTRACT FROM AUTHOR]

We would like to correct a typographical error. In the last paragraph of Page N296, line 4, it should read 'a =1.2269, b = -0.9446, g = 1.1046 and d = -0.004' [ABSTRACT FROM AUTHOR]

We propose a scheme for generating a genuine four-particle polarisation entangled state |kh00) that has many interesting entanglement properties and potential applications in quantum information processing. In our scheme, we use the weak cross-Kerr nonlinear interaction between field-modes and the non-demolition measurement method based on highly efficient homodyne detection, which is feasible under the current experiment conditions. [ABSTRACT FROM AUTHOR]

The nonlinear optical properties of an azobenzene polymer azo12—MO were investigated by a Z-scan technique. The polymer was synthesized by assembling the liquid-crystalline polymer azo12 with methyl orange. The nonlinear refractive index (1.39 × 10−15 cm2/W) and the nonlinear absorption coefficient (0.11 cm/GW) of azo12—MO were determined with 532-nm picosecond laser pulses at the irradiance of 92.40 GW/cm2. When compared to the nonlinear properties of azo12 and methyl orange, azo12—MO possesses the advantages of its two constituents and shows larger nonlinear optical properties. [ABSTRACT FROM AUTHOR]

We analyze the responsivity and signal-to-noise ratio (SNR) of a punchthrough enhanced phototransistor (PEPT). Measurement results show that the PEPT exhibits a good response to light over a wide range of intensity. Because the responsivity is still as high as 106 A/W when the bias voltage is as low as 0.2 V, the device is suitable for ultra-low voltage applications. Meanwhile, with 1-10 μA bias current, the PEPT shows the best performance for the responsivity and SNR. When incident light is as low as 3.8×10-8 W/cm2, the responsivity reaches approximately 108 A/W. The super high responsivity of PEPTs makes it possible to fabricate small sized photodetector. [ABSTRACT FROM AUTHOR]

This paper studies two-dimensional analysis of the surface state effect on current gain for a 4H-SiC bipolar junction transistor (BJT). Simulation results indicate the mechanism of current gain degradation, which is surface Fermi level pinning leading to a strong downward bending of the energy bands to form the channel of surface electron recombination current. The experimental results are well-matched with the simulation, which is modeled by exponential distributions of the interface state density replacing the single interface state trap. Furthermore, the simulation reveals that the oxide quality of the base emitter junction interface is very important for 4H-SiC BJT performance. [ABSTRACT FROM AUTHOR]

In this paper, a new structure of a 4H-SiC bipolar junction transistor (BJT) with a buried layer (BL) in the base is presented. The current gain shows an approximately 100% increase compared with that of the conventional structure. This is attributed to the creation of a built-in electric field for the minority carriers to transport in the base which is explained based on 2D device simulations. The optimized design of the buried layer region is also considered by numeric simulations. [ABSTRACT FROM AUTHOR]

A new analytical model of high voltage silicon on insulator (SOI) thin film devices is proposed, and a formula of silicon critical electric field is derived as a function of silicon film thickness by solving a 2D Poisson equation from an effective ionization rate, with a threshold energy taken into account for electron multiplying. Unlike a conventional silicon critical electric field that is constant and independent of silicon film thickness, the proposed silicon critical electric field increases sharply with silicon film thickness decreasing especially in the case of thin films, and can come to 141 V/mm at a film thickness of 0.1 mm which is much larger than the normal value of about 30V/mm. From the proposed formula of silicon critical electric field, the expressions of dielectric layer electric field and vertical breakdown voltage (VB,V) are obtained. Based on the model, an ultra thin film can be used to enhance dielectric layer electric field and so increase vertical breakdown voltage for SOI devices because of its high silicon critical electric field, and with a dielectric layer thickness of 2mm the vertical breakdown voltages reach 852 and 300V for the silicon film thicknesses of 0.1 and 5mm, respectively. In addition, a relation between dielectric layer thickness and silicon film thickness is obtained, indicating a minimum vertical breakdown voltage that should be avoided when an SOI device is designed. 2D simulated results and some experimental results are in good agreement with analytical results. [ABSTRACT FROM AUTHOR]

To study theoretically the relationship between the differential interference angle and the scattering angle in collisional quantum interference (CQI), we have investigated the differential interference angle of the atom-diatomic [case(a)] molecule system in detail. For the 2? electronic state in Hund's case (a), the degree of the differential interference is also discussed. The differential interference angles of NO(X2?) are calculated quantitatively for the rotational energy transfer in Hund's case (a) induced by collision with He, Ne and Ar atoms. The method to calculate the differential interference angle is presented. Several factors that affect the differential interference angle are investigated. Finally the variation of the differential interference angle with the impact parameter and relative velocity is discussed. [ABSTRACT FROM AUTHOR]

A new super-junction lateral double diffused MOSFET (LDMOST) structure is designed with n-type charge compensation layer embedded in the p[?]-substrate near the drain to suppress substrate-assisted depletion effect that results from the compensating charges imbalance between the pillars in the n-type buried layer. A high electric field peak is introduced in the surface by the pn junction between the p[?]-substrate and n-type buried layer, which given rise to a more uniform surface electric field distribution by modulation effect. The effect of reduced bulk field (REBULF) is introduced to improve the vertical breakdown voltage by reducing the high bulk electric field around the drain. The new structure features high breakdown voltage, low on-resistance and charges balance in the drift region due to n-type buried layer. [ABSTRACT FROM AUTHOR]

A new lateral double diffused metal oxide semiconductor field effect transistor with a double-charge accumulation layer using a folded silicon substrate is proposed to improve the performance of the breakdown voltage and specific on-resistance. Three kinds of technologies, which are the additional electric field modulation effect, majority carrier accumulation and increasing the effective conduction area, are applied simultaneously by a semi-insulating polycrystalline silicon layer deposited over the top of thin oxide covering the drift region. It is indicated that by the simulator, the ideal silicon limits of the breakdown voltage and specific on-resistance have been broken due to the complete three-dimensional reduced surface field effect and the doubled majority carrier accumulation layer. [ABSTRACT FROM AUTHOR]

Using optical fiber devices at the terminal is an important means to improve the performance of free space optical communication systems. We proposed a Fraunhofer diffraction integral based method to calculate the coupling efficiency between spatial light and few-mode fiber, and studied the influences of alignment tolerance on coupling efficiency. Numerical simulations confirm that the results obtained by this new method are consistent with the traditional calculation method. What is more, a few-mode fiber has flatter response characteristics to F-number mismatch, fiber lateral offset and defocus. Compared with single mode fiber, few-mode fibers can not only improve the maximum coupling efficiency, but also their coupling efficiency is much less sensitive to deviations from ideal conditions, thereby making them a more practical option for real world applications. [ABSTRACT FROM AUTHOR]

Free radical species in aqueous solution—various alcohol–water reaction mixtures—by exposure to non-equilibrium cold atmospheric pressure Ar plasma (CAP), were monitored using electron paramagnetic resonance spin-trapping techniques with 3, 5-dibromo-4-nitrosobenzene sulfonate as a water soluble nitroso spin trap. The major radical species were formed by H-abstraction from alcohol molecules due to ·OH radicals. In the ethanol–water mixture ·CH2CH2OH produced by H abstraction from CH3 group of the ethanol and ·CH3 radicals were detected. The latter was due to the decomposition of unstable CH3·CHOH to form the ·CH3 radicals and the stable formaldehyde by C–C bond fission. These intermediates are similar to those observed by reaction with ·OH radicals generation in the H2O2–UV photolysis of the reaction mixtures. The evidence of ·CH3 radical formation in the pyrolytic decomposition of the reaction mixtures by exposure to ultrasound or in methane irradiated with microwave plasma have been reported previously. However, the pyrolytic ·CH3 radicals were not found in both plasma and H2O2–UV photolysis condition. These results suggests that free radicals produced by Ar-CAP are most likely due to the reaction between abundant ·OH radicals and alcohol molecules. [ABSTRACT FROM AUTHOR]

Engineering local angular momentum of structured light fields in real space enables applications in many fields, in particular, the realization of unidirectional robust transport in topological photonic crystals with a non-trivial Berry vortex in momentum space. Here, we show transverse angular momentum modes in silicon topological photonic crystals when considering transverse electric polarization. Excited by a chiral external source with either transverse spin angular momentum or transverse phase vortex, robust light flow propagating along opposite directions is observed in several kinds of sharp-turn interfaces between two topologically-distinct silicon photonic crystals. A transverse orbital angular momentum mode with alternating phase vortex exists at the boundary of two such photonic crystals. In addition, unidirectional transport is robust to the working frequency even when the ring size or location of the pseudo-spin source varies in a certain range, leading to the superiority of the broadband photonic device. These findings enable one to make use of transverse angular momentum, a kind of degree of freedom, to achieve unidirectional robust transport in the telecom region and other potential applications in integrated photonic circuits, such as on-chip robust delay lines. [ABSTRACT FROM AUTHOR]

A systematic investigation of oxidation on a superconductive FeTe0.5Se0.5 thin film, which was grown on Nb-doped SrTiO3 (001) by pulsed laser deposition, has been carried out. The sample was exposed to ambient air for one month for oxidation. Macroscopically, the exposed specimen lost its superconductivity due to oxidation. The specimen was subjected to in situ synchrotron radiation photoelectron spectroscopy (PES) and x-ray absorption spectroscopy (XAS) measurements following cycles of annealing and argon ion etching treatments to unravel what happened in the electronic structure and composition after exposure to air. By the spectroscopic measurements, we found that the as-grown FeTe0.5Se0.5 superconductive thin film experienced an element selective substitution reaction. The oxidation preferentially proceeds through pumping out the Te and forming Fe–O bonds by O substitution of Te. In addition, our results certify that in situ vacuum annealing and low-energy argon ion etching methods combined with spectroscopy are suitable for depth element and valence analysis of layered structure superconductor materials. [ABSTRACT FROM AUTHOR]

A novel silicon-on-insulator (SOI) trench metal-oxide-semiconductor field effect transistor (MOSFET) with a reduced specific on-resistance (Ron,sp) is presented. It features an oxide-filled trench and a non-depleted embedded p-type island (p-SOI). The oxide trench folds the drift region into a U-shape, resulting in a reduction in cell pitch and Ron,sp. The non-depleted p-island is employed to further reduce Ron,sp by increasing the optimized doping concentration of the drift region without deteriorating the breakdown voltage (BV). The simulation results show that the p-SOI decreases the fion, sp to 10.2mΩcm² from 17.4mQcm² of the conventional SOI MOSFET at the same BV. [ABSTRACT FROM AUTHOR]

In this paper, a novel dual-gate and dielectric-inserted lateral trench insulated gate bipolar transistor (DGDI LTIGBT) structure, which features a double extended trench gate and a dielectric inserted in the drift region, is proposed and discussed. The device can not only decrease the specific on-resistance Ron,sp, but also simultaneously improve the temperature performance. Simulation results show that the proposed LTIGBT achieves an ultra-low on-state voltage drop of 1.31 V at 700 A·cm² with a small half-cell pitch of 10.5 μm, a specific on-resistance Ron,sp of 187 mΩ ·mm², and a high breakdown voltage of 250 V. The on-state voltage drop of the DGDI LTIGBT is 18% less than that of the DI LTIGBT and 30.3% less than that of the conventional LTIGBT. The proposed LTIGBT exhibits a good positive temperature coefficient for safety paralleling to handling larger currents and enhances the short-circuit capability while maintaining a low self-heating effect. Furthermore, it also shows a better tradeoff between the specific on-resistance and the turnoff loss, although it has a longer turnoff delay time. [ABSTRACT FROM AUTHOR]

In this paper, a subwavelength metal-grating assisted sensor of Kretschmann style that is capable of detecting the sample with a refractive index higher than that of the substrate is proposed. The sensor configuration is similar to the traditional Kretschmann structure, but the metal film is pattered into a grating. As a TM-polarized laser beam impinges from the substrate, a resonant dip point in reflectance curve is produced at a certain incident angle. Our studies indicate that the sensing sensitivity and resolution are affected by the grating’s gap and period, and after these parameters have been optimized, a sensing sensitivity of 51.484°/RIU is obtained with a slightly changing resolution. [ABSTRACT FROM AUTHOR]

A novel super-junction lateral double-diffused metal--oxide semiconductor (SJ-LDMOS) with a partial lightly doped P pillar (PD) is proposed. Firstly, the reduction in the partial P pillar charges ensures the charge balance and suppresses the substrate-assisted depletion effect. Secondly, the new electric field peak produced by the P/P- junction modulates the surface electric field distribution. Both of these result in a high breakdown voltage (BV). In addition, due to the same conduction paths, the specific on-resistance (Ron,sp) of the PD SJ-LDMOS is approximately identical to the conventional SJ-LDMOS. Simulation results indicate that the average value of the surface lateral electric field of the PD SJ-LDMOS reaches 20 V/µm at a 15 m drift length, resulting in a BV of 300 V. [ABSTRACT FROM AUTHOR]

A novel controllable hybrid-anode AlGaN/GaN field-effect rectifier (HA-FER) with low operation voltage (LOV) is proposed. Its mechanism can be explained by the field-controlled energy band model. This model reveals that the electric field in the AlGaN layer alters the energy band to result in a variation of the two-dimensional electron gas (2DEG) at AlGaN/GaN interface; the field can be changed by the thickness d of the AlGaN layer and the applied bias. As the d reduces below the critical thickness, the 2DEG vanishes and then the channel is pinched off. Therefore, the threshold voltage of HA-FER can be designed as low as 0V leading to LOV (<1 V). The analytical characteristic of the HA-FER is calculated and validated by the simulated results. These results also demonstrate that the forward properties of HA-FER are superior to the conventional SBD due to the high Schottky barrier. [ABSTRACT FROM AUTHOR]

Based on the theoretical and experimental investigation of a thin silicon layer (TSL) with linear variable doping (LVD) and further research on the TSL LVD with a multiple step field plate (MSFP), a breakdown voltage (BV) model is proposed and experimentally verified in this paper. With the two-dimensional Poisson equation of the silicon on insulator (SOI) device, the lateral electric field in drift region of the thin silicon layer is assumed to be constant. For the SOI device with LVD in the thin silicon layer, the dependence of the BV on impurity concentration under the drain is investigated by an enhanced dielectric layer field (ENDIF), from which the reduced surface field (RESURF) condition is deduced. The drain in the centre of the device has a good self-isolation effect, but the problem of the high voltage interconnection (HVI) line will become serious. The two step field plates including the source field plate and gate field plate can be adopted to shield the HVI adverse effect on the device. Based on this model, the TSL LVD SOI n-channel lateral double-diffused MOSFET (nLDMOS) with MSFP is realized. The experimental breakdown voltage (BV) and specific on-resistance (Ron;sp) of the TSL LVD SOI device are 694 V and 21.3 Ω.mm2 with a drift region length of 60 µm, buried oxide layer of 3 µm, and silicon layer of 0.15 µm, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we present a monolithic integration of a self-protected AlGaN/GaN metal-insulator field-effect transistor (MISFET). An integrated field-controlled diode on the drain side of the AlGaN/GaN MISFET features a selfprotected function for a reverse bias. This diode takes advantage of the recessed-barrier enhancement-mode technique to realize an ultra-low voltage drop and a low turn-ON voltage. In the smart monolithic integration, this integrated diode can block a reverse bias (> 70 V/&ghr;m) and suppress the leakage current (< 5 × 10-11 A/mm). Compared with conventional monolithic integration, the numerical results show that the MISFET integrated with a field-controlled diode leads to a good performance for smart power integration. And the power loss is lower than 50% in conduction without forward current degeneration. [ABSTRACT FROM AUTHOR]

A new analytical model for the surface electric field distribution and breakdown voltage of the silicon on insulator (SOI) trench lateral double-diffused metal-oxide-semiconductor (LDMOS) is presented. Based on the two-dimensional Laplace solution and Poisson solution, the model considers the influence of structure parameters such as the doping concentration of the drift region, and the depth and width of the trench on the surface electric field. Further, a simple analytical expression of the breakdown voltage is obtained, which offers an effective way to gain an optimal high voltage. All the analytical results are in good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

A new high-voltage and low-specific on-resistance (Ron,sp) adaptive buried electrode (ABE) silicon-on-insulator (SOI) power lateral MOSFET and its analytical model of the electric fields are proposed. The MOSFET features are that the electrodes are in the buried oxide (BOX) layer, the negative drain voltage Vd is divided into many partial voltages and the output to the electrodes is in the buried oxide layer and the potentials on the electrodes change linearly from the drain to the source. Because the interface silicon layer potentials are lower than the neighboring electrode potentials, the electronic potential wells are formed above the electrode regions, and the hole potential wells are formed in the spacing of two neighbouring electrode regions. The interface hole concentration is much higher than the electron concentration through designing the buried layer electrode potentials. Based on the interface charge enhanced dielectric layer field theory, the electric field strength in the buried layer is enhanced. The vertical electric field EI and the breakdown voltage (BV) of ABE SOI are 545 V/μm and -587 V in the 50 μm long drift region and the 1 μm thick dielectric layer, and a low Ron;sp is obtained. Furthermore, the structure also alleviates the self-heating effect (SHE). The analytical model matches the simulation results. [ABSTRACT FROM AUTHOR]

We studied the horizontal branch oscillations (HBO) and the band-limited components observed in the power spectra of the transient neutron star low-mass X-ray binary XTE J1701-462 and the persistent “Sco-like” Z source GX 17+2. These two components were studied based on the state-resolved spectra. We found that the frequencies of XTE J1701-462 lie on the known correlations (WK and PBK), showing consistency with other types of X-ray binaries (black holes, atoll sources, and millisecond X-ray pulsars). However, GX 17+2 is shifted from the WK correlation like other typical Z sources. We suggest that the WK/PBK main track forms a boundary that separates persistent sources from transient sources. The characteristic frequencies of break and HBO are independent of accretion rate in both sources, though it depends on spectral models. We also report the energy dependence of the HBO and break frequencies in XTE J1701-462 and how the temporal properties change with spectral state in XTE J1701-462 and GX 17+2. We studied the correlation between rms at the break and the HBO frequency. We suggest that HBO and break components for both sources probably arise from a similar physical mechanism: Comptonization emission from the corona. These two components could be caused by the same kind of oscillation in a corona with uneven density, and they could be generated from different areas of the corona. We further suggest that different proportions of the Comptonization component in the total flux cause the different distribution between GX 17+2 and XTE J1701-462 in the rmsbreak-rmsHBO diagram. [ABSTRACT FROM AUTHOR]

In observations, it is important to deproject the two fundamental quantities characterizing a bar, i.e., its length (a) and ellipticity (e), to face-on values before any careful analyses. However, systematic estimation on the uncertainties of the commonly used deprojection methods is still lacking. Simulated galaxies are well suited in this study. We project two simulated barred galaxies onto a two-dimensional (2D) plane with different bar orientations and disk inclination angles (i). Bar properties are measured and deprojected with the popular deprojection methods in the literature. Generally speaking, deprojection uncertainties increase with increasing i. All of the deprojection methods behave badly when i is larger than 60°, due to the vertical thickness of the bar. Thus, future statistical studies of barred galaxies should exclude galaxies more inclined than 60°. At moderate inclination angles (i ⩽ 60°), 2D deprojection methods (analytical and image stretching), and Fourier-based methods (Fourier decomposition and bar-interbar contrast) perform reasonably well with uncertainties ∼10% in both the bar length and ellipticity, whereas the uncertainties of the one-dimensional (1D) analytical deprojection can be as high as 100% in certain extreme cases. We find that different bar measurement methods show systematic differences in the deprojection uncertainties. We further discuss the deprojection uncertainty factors with the emphasis on the most important one, i.e., the three-dimensional structure of the bar itself. We construct two triaxial toy bar models that can qualitatively reproduce the results of the 1D and 2D analytical deprojections; they confirm that the vertical thickness of the bar is the main source of uncertainties. [ABSTRACT FROM AUTHOR]

A novel high-voltage light punch-through (LPT) carrier stored trench bipolar transistor (CSTBT) with buried p-layer (BP) is proposed in this paper. Since the negative charges in the BP layer modulate the bulk electric field distribution, the electric field peaks both at the junction of the p base/n-type carrier stored (N-CS) layer and the corners of the trench gates are reduced, and new electric field peaks appear at the junction of the BP layer/N- drift region. As a result, the overall electric field in the N- drift region is enhanced and the proposed structure improves the breakdown voltage (BV) significantly compared with the LPT CSTBT. Furthermore, the proposed structure breaks the limitation of the doping concentration of the N-CS layer (NN-CS) to the BV, and hence a higher NN-CS can be used for the proposed LPT BP-CSTBT structure and a lower on-state voltage drop (Vce(sat)) can be obtained with almost constant BV. The results show that with a BP layer doping concentration of NBP = 7×1015 cm-3, a thickness of LBP = 2.5 μm, and a width of WBP = 5 μm, the BV of the proposed LPT BP-CSTBT increases from 1859 V to 1862 V, with NN-CS increasing from 5 × 1015 cm-3 to 2.5 × 1016 cm-3. However, with the same N--drift region thickness of 150 μm and NN-CS, the BV of the CSTBT decreases from 1598 V to 247 V. Meanwhile, the Vce(sat) of the proposed LPT BP-CSTBT structure decreases from 1.78 V to 1.45 V with NN-CS increasing from 5 × 1015 cm-3 to 2.5 × 1016 cm-3. [ABSTRACT FROM AUTHOR]