759 research outputs found
Managers’ Bad Accounting Behaviors of Listed Companies in China
Managers’ unintentional or intentional bad accounting behaviors will result in poor quality of accounting information of listed companies, making a great extent to interfere with investors, causing confusion in the capital market, is not conducive to reflect the performance management responsibility. Research on Managers bad accounting behaviors of listed companies is of great significance to improve management, optimize the allocation of social resources. This paper respectively discusses the manifestation and the causes both of managers’ unintentional and intentional bad accounting behaviors. It also puts forward recommendations to prevent managers’ bad accounting behaviors of listed companies in China, so as to safeguard the interests of stakeholders and provide good environment for capital market by improving the efficiency and accounting information quality of listed companies.Key words: Bad accounting behaviors; Managers; Listed companies; The quality of accounting informatio
Investigations of supernovae and supernova remnants in the era of SKA
Two main physical mechanisms are used to explain supernova explosions:
thermonuclear explosion of a white dwarf(Type Ia) and core collapse of a
massive star (Type II and Type Ib/Ic). Type Ia supernovae serve as distance
indicators that led to the discovery of the accelerating expansion of the
Universe. The exact nature of their progenitor systems however remain unclear.
Radio emission from the interaction between the explosion shock front and its
surrounding CSM or ISM provides an important probe into the progenitor star's
last evolutionary stage. No radio emission has yet been detected from Type Ia
supernovae by current telescopes. The SKA will hopefully detect radio emission
from Type Ia supernovae due to its much better sensitivity and resolution.
There is a 'supernovae rate problem' for the core collapse supernovae because
the optically dim ones are missed due to being intrinsically faint and/or due
to dust obscuration. A number of dust-enshrouded optically hidden supernovae
should be discovered via SKA1-MID/survey, especially for those located in the
innermost regions of their host galaxies. Meanwhile, the detection of
intrinsically dim SNe will also benefit from SKA1. The detection rate will
provide unique information about the current star formation rate and the
initial mass function. A supernova explosion triggers a shock wave which expels
and heats the surrounding CSM and ISM, and forms a supernova remnant (SNR). It
is expected that more SNRs will be discovered by the SKA. This may decrease the
discrepancy between the expected and observed numbers of SNRs. Several SNRs
have been confirmed to accelerate protons, the main component of cosmic rays,
to very high energy by their shocks. This brings us hope of solving the
Galactic cosmic ray origin's puzzle by combining the low frequency (SKA) and
very high frequency (Cherenkov Telescope Array: CTA) bands' observations of
SNRs.Comment: To be published in: "Advancing Astrophysics with the Square Kilometre
Array", Proceedings of Science, PoS(AASKA14
6,8-Di-tert-butyl-3-(4-nitrophenyl)-2H-chromen-2-one
The title compound, C23H25NO4, was synthesized by the reaction of 2-(4-nitrophenyl)acetonitrile and 3,5-di-tert-butyl-2-hydroxybenzaldehyde. The dihedral angle formed by the benzene ring and the mean plane through the benzopyranone ring system is 35.57 (5)°. The nitro group is almost coplanar with the attached benzene ring [dihedral angle = 5.19 (15)°]. The crystal packing is stabilized by an intermolecular C—H⋯O hydrogen-bond interaction
Proper Scaling of the Anomalous Hall Effect
Working with epitaxial films of Fe, we succeeded in independent control of
different scattering processes in the anomalous Hall effect. The result
appropriately accounted for the role of phonons, thereby clearly exposing the
fundamental flaws of the standard plot of the anomalous Hall resistivity versus
longitudinal resistivity. A new scaling has been thus established that allows
an unambiguous identification of the intrinsic Berry curvature mechanism as
well as the extrinsic skew scattering and side-jump mechanisms of the anomalous
Hall effect.Comment: 5 pages, 4 figure
Multivariable Scaling for the Anomalous Hall Effect
We derive a general scaling relation for the anomalous Hall effect in
ferromagnetic metals involving multiple competing scattering mechanisms,
described by a quadratic hypersurface in the space spanned by the partial
resistivities. We also present experimental findings, which show strong
deviation from previously found scaling forms when different scattering
mechanism compete in strength but can be nicely explained by our theory
Structure Evaluation of AES-like Ciphers against Mixture Differential Cryptanalysis
In ASIACRYPT 2017, Rønjom et al. analyzed AES with yoyo attack. Inspired by their 4-round AES distinguisher, Grassi proposed the mixture differential cryptanalysis as well as a key recovery attack on 5-round AES, which was shown to be better than the classical square attack in computation complexity.
After that, Bardeh et al. combined the exchange attack with the 4-round mixture differential distinguisher of AES, leading to the first secret-key chosen plaintext distinguisher for 6-round AES. Unlike the attack on 5-round AES, the result of 6-round key-recovery attack on AES has extremely large complexity, which implies the weakness of mixture difference to a certain extent. Our work aims at evaluating the security of AES-like ciphers against mixture differential cryptanalysis. We propose a new structure called a boomerang struncture and illustrate that a
differential distinguisher of a boomerang struncture just corresponds to a mixture differential distinguisher for AES-like ciphers. Based on the boomerang structure, it is shown that the mixture differential cryptanalysis is not suitable to be applied
to AES-like ciphers with high round number. In specific, we associate the primitive index with our framework built on the boomerang structure and give the upper bound for the length of mixture differentials with probability 1 on AES-like ciphers. It can be directly deduced from our framework that there is no mixture differential distinguisher for 6-round AES
Evidence of the side jump mechanism in the anomalous Hall effect in paramagnets
Persistent confusion has existed between the intrinsic (Berry curvature) and
the side jump mechanisms of anomalous Hall effect (AHE) in ferromagnets. We
provide unambiguous identification of the side jump mechanism, in addition to
the skew scattering contribution in epitaxial paramagnetic NiCu
thin films, in which the intrinsic contribution is by definition excluded.
Furthermore, the temperature dependence of the AHE further reveals that the
side jump mechanism is dominated by the elastic scattering
Improved Distinguisher Search Techniques Based on Parity Sets
Division property is a distinguishing property against block ciphers proposed by Todo at EUROCRYPT 2015. To give a new approach to division property, Christina et al. proposed a new notion called the parity set at CRYPTO 2016. Using parity sets, they successfully took further properties of S-boxes and linear layers into account and found improved distinguishers against PRESENT. However, the time and memory complexities to compute parity sets are expensive. In this paper, we introduce the idea of meet-in-the-middle to the integral distinguisher search along with a variety of techniques to reduce computation complexity. As a result, we obtain a new distinguisher against 9-round PRESENT which has 22 balanced bits
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