This paper studies high-dimensional vector autoregressions (VARs) augmented with common factors that allow for strong cross-sectional dependence. Models of this type provide a convenient mechanism ...for accommodating the interconnectedness and temporal co-variability that are often present in large dimensional systems. We propose an ℓ1-nuclear-norm regularized estimator and derive the non-asymptotic upper bounds for the estimation errors as well as large sample asymptotics for the estimates. A singular value thresholding procedure is used to determine the correct number of factors with probability approaching one. Both the LASSO estimator and the conservative LASSO estimator are employed to improve estimation precision. The conservative LASSO estimates of the non-zero coefficients are shown to be asymptotically equivalent to the oracle least squares estimates. Simulations demonstrate that our estimators perform reasonably well in finite samples given the complex high-dimensional nature of the model. In an empirical illustration we apply the methodology to explore dynamic connectedness in the volatilities of financial asset prices and the transmission of ‘investor fear’. The findings reveal that a large proportion of connectedness is due to the common factors. Conditional on the presence of these common factors, the results still document remarkable connectedness due to the interactions between the individual variables, thereby supporting a common factor augmented VAR specification.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the hierarchical theory of galaxy formation, a galaxy overdensity is a hallmark of a massive cosmic structure. However, it is less well understood how different types of galaxies trace the ...underlying large-scale structure. Motivated by the discovery of a z = 3.13 protocluster, we examine how the same structure is populated by Ly -emitting galaxies (LAEs). To this end, we have undertaken a deep narrowband imaging survey sampling Ly emission at this redshift. Of the 93 LAE candidates within a 36′ × 36′ (70 × 70 Mpc2) field, 21 galaxies form a significant surface overdensity (δ , LAE = 3.3 0.9), which is spatially segregated from the Lyman break galaxy (LBG) overdensity. One possible interpretation is that they trace two separate structures of comparable masses ( 1015 M ) where the latter is hosted by a halo assembled at an earlier time. We speculate that the dearth of LAEs in the LBG overdensity region may signal the role of halo assembly bias in galaxy formation, which would suggest that different search techniques may be biased accordingly to the formation age or dynamical state of the host halo. The median Ly and UV luminosity is 30%-70% higher for the protocluster LAEs relative to the field. This difference cannot be explained by the galaxy overdensity alone and may require a top-heavy mass function, higher star formation efficiency for protocluster halos, or suppression of galaxy formation in low-mass halos. A luminous Ly blob and an ultramassive galaxy found in this region paint a picture consistent with the expected early growth of galaxies in clusters.
sp2 carbon-conjugated covalent organic frameworks (sp2c-COFs) with superb in-plane π-conjugations, high chemical stability, and robust framework structure are expected to be ideal films/membranes for ...a wide range of applications including energy-related devices and optoelectronics. However, so far, sp2c-COFs have been mainly limited to microcrystalline powders, and this consequently hampered their performances in devices. Herein, we report a simple and robust methodology to fabricate large-area, free-standing, and crystalline sp2c-COF films (TFPT–TMT and TB–TMT) on various solid substrates (e.g., fluorine-doped tin oxide, aluminum sheet, polyacrylonitrile membrane) by self-assembly monolayer-assisted surface-initiated Schiff-base-mediated aldol polycondensation (namely, SI-SBMAP). The resultant sp2c-COF films show lateral sizes up to 120 cm2 and tunable thickness from tens of nanometers to a few micrometers. Owing to the robust framework and highly ordered quasi-1D channels, the sp2c-COF membrane-based osmotic power generator presents an output power density of 14.1 W m–2 under harsh conditions, outperforming most reported COF membranes as well as commercialized benchmark devices (5 W m–2). This work demonstrates a simple and robust interfacial methodology for the fabrication of sp2c-COF films/membranes for green energy applications and potential optoelectronics.
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IJS, KILJ, NUK, PNG, UL, UM
The super τ-charm facility (STCF) is an electron−positron collider proposed by the Chinese particle physics community. It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with ...a peak luminosity of 0.5 × 10 35 cm −2·s −1 or higher. The STCF will produce a data sample about a factor of 100 larger than that of the present τ-charm factory - the BEPCII, providing a unique platform for exploring the asymmetry of matter-antimatter (charge-parity violation), in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions, as well as searching for exotic hadrons and physics beyond the Standard Model. The STCF project in China is under development with an extensive R&D program. This document presents the physics opportunities at the STCF, describes conceptual designs of the STCF detector system, and discusses future plans for detector R&D and physics case studies.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Equiatomic alloys (e.g. high entropy alloys) have recently attracted considerable interest due to their exceptional properties, which might be closely related to their extreme disorder induced by the ...chemical complexity. In order to understand the effects of chemical complexity on their fundamental physical properties, a family of (eight) Ni-based, face-center-cubic (FCC), equiatomic alloys, extending from elemental Ni to quinary high entropy alloys, has been synthesized, and their electrical, thermal, and magnetic properties are systematically investigated in the range of 4-300 K by combining experiments with ab initio Korring-Kohn-Rostoker coherent-potential-approximation (KKR-CPA) calculations. The scattering of electrons is significantly increased due to the chemical (especially magnetic) disorder. It has weak correlation with the number of elements but strongly depends on the type of elements. Thermal conductivities of the alloys are largely lower than pure metals, primarily because the high electrical resistivity suppresses the electronic thermal conductivity. The temperature dependence of the electrical and thermal transport properties is further discussed, and the magnetization of five alloys containing three or more elements is measured in magnetic fields up to 4 T.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A search for the charged lepton flavor violating decay J/ψ → e± τ∓ with τ∓ → π∓ π0 ντ is performed with about 10 × 10 9 J/ψ events collected with the BESIII detector at the BEPCII. No significant ...signal is observed, and an upper limit is set on the branching fraction B (J/ψ → e± τ∓) < 7.5 × 10−8 at the 90% confidence level. This improves the previously published limit by two orders of magnitude.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
A search for invisible decays of the Lambda baryon is carried out in the process J/psi -> Lambda(Lambda) over bar based on (1.0087 +/- 0.0044) x 10(10) J/psi events collected with the BESIII ...detector located at the BEPCII storage ring. No signals are found for the invisible decays of. baryon, and the upper limit of the branching fraction is determined to be 7.4 x 10(-5) at the 90% confidence level. This is the first search for invisible decays of baryons; such searches will play an important role in constraining dark sector models related to the baryon asymmetry.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Previous work on studying FCC/BCC martensite transformations using molecular dynamics (MD) was mainly adopting an atomistically flat interface between the two transforming phases as initial ...structural model, whereas recent HRTEM observations show that martensitic interfaces are comprised of atomic terraces with regularly distributed steps reticulated by interfacial defects. In this work, migration behavior of stepped FCC/BCC martensitic interface aided by disconnections is studied using MD simulation method, and two typical orientation relationships (ORs), i.e., Kurdjumov–Sachs (KS) and Nishiyama–Wassermann (NW) ORs, commonly found in ferrous alloys are considered. For both ORs, the stepped interfaces maintain a macroscopically planar morphology as they advance in constant velocities by the collective motion of disconnections in the absence of homogeneous nucleation. The migration velocities of interfaces as obtained are 550 and 90 m·s
−1
for the NW and KS ORs, respectively, showing good agreement with published experimental measurements. The disconnections under the NW OR exhibit edge defect character and move laterally along the terrace plane at a velocity approaching the speed of sound, while remaining straight along their dislocation lines, whereas the disconnections under the KS OR possess screw defect character and migrate in a zigzag and sluggish manner through cross-slipping on two nonparallel planes of
{
101
}
BCC
by a kink pair mechanism. By implementing a thin slab of atoms as tracing marker in the simulation model, the transformation shear accompanying the interface motion can be quantified and the so-determined transformation shear angles show good agreement with experimental measurements. The results provide a physical insight into the interrelations between interface structure and transformation process, which is crucial for understanding the atomic mechanism of martensitic transformations.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Highlights ► Implantation sarcoma-induced bone cancer pain and upregulation of SCN7A/Nax in DRG. ► Knockdown of SCN7A reversed bone cancer pain. ► Enhanced expression of SCN7A/Nax increased the ...neuron excitability. ► SCN7A/Nax knockdown suppressed the excitability of SCN7A/Nax-positive neurons.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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