103 research outputs found
ON THE SMARANDACHE FUNCTION AND SQUARE COMPLEMENTS
The main purpose of this paper is using the elementary method to study the mean value properties of the Smarandache function, and give an interesting asymptotic formula
On a problem of D.H. Lehmer over short intervals
AbstractLet p be an odd prime and a be an integer coprime to p. Denote by N(a,p) the number of pairs of integers b,c with bc≡a (mod p), 1⩽b,c⩽(p−1)2 and with b,c having different parity. The main purpose of this paper is to study the sum ∑a=1p−1(N(a,p)−(p−1)8)2, and obtain a sharp asymptotic formula
On the order of the high-dimensional Cochrane sum and its mean value
AbstractThe main purpose of this paper is to study the high-dimensional Cochrane sum and give a sharp estimate of its order by using properties of hyper-Kloosterman sum and the mean value theorems of Dirichlet L-functions
Sharp uncertainty principles on metric measure spaces
We study the Heisenberg-Pauli-Weyl uncertainty principle and the
Caffarelli-Kohn-Nirenberg interpolation inequalities, on metric measure spaces
satisfying measure contraction property. Using localization techniques, we show
that these inequalities are valid only on volume cones
On the generalized Cochrane sum with Dirichlet characters
In this paper, we defined a new generalized Cochrane sum with Dirichlet characters, and gave the upper bound of the generalized Cochrane sum with Dirichlet characters. Moreover, we studied the asymptotic estimation problem of the mean value of the generalized Cochrane sum with Dirichlet characters and obtained a sharp asymptotic formula for it. By using this asymptotic formula, we also gave the mean value of the generalized Dedekind sum
Transmission of new CRF07_BC Strains with 7 amino acid deletion in Gag p6
A 7 amino acid deletion in Gag p6 (P6delta7) emerged in Chinese prevalent HIV-1 strain CRF07_BC from different epidemic regions. It is important to determine whether this mutation could be transmitted and spread. In this study, HIV-1 Gag sequences from 5 different epidemic regions in China were collected to trace the transmission linkage and to analyze genetic evolution of P6delta7 strains. The sequence analysis demonstrated that P6delta7 is a CRF07_BC specific deletion, different P6delta7 strains could be originated from different parental CRF07_BC recombinants in different epidemic regions, and the transmission of P6delta7 strain has occurred in IDU populations. This is for the first time to identify the transmission linkage for P6delta7 strains and serves as a wake-up call for further monitoring in the future; In addition, P6delta7 deletion may represent an evolutionary feature which might exert influence on the fitness of CRF07_BC strain
Extremely large magnetoresistance in topologically trivial semimetal -WP
Extremely large magnetoresistance (XMR) was recently discovered in many
non-magnetic materials, while its underlying mechanism remains poorly
understood due to the complex electronic structure of these materials. Here, we
report an investigation of the -phase WP, a topologically trivial
semimetal with monoclinic crystal structure (C2/m), which contrasts to the
recently discovered robust type-II Weyl semimetal phase in -WP. We
found that -WP exhibits almost all the characteristics of XMR
materials: the near-quadratic field dependence of MR, a field-induced up-turn
in resistivity following by a plateau at low temperature, which can be
understood by the compensation effect, and high mobility of carriers confirmed
by our Hall effect measurements. It was also found that the normalized MRs
under different magnetic fields has the same temperature dependence in
-WP, the Kohler scaling law can describe the MR data in a wide
temperature range, and there is no obvious change in the anisotropic parameter
value with temperature. The resistance polar diagram has a peanut
shape when field is rotated in plane, which can be understood by
the anisotropy of Fermi surface. These results indicate that both
field-induced-gap and temperature-induced Lifshitz transition are not the
origin of up-turn in resistivity in the -WP semimetal. Our findings
establish -WP as a new reference material for exploring the XMR
phenomena.Comment: 18 pages, 12 figure
Evidence for chiral superconductivity in Kagome superconductor CsV3Sb5
The interplay among frustrated lattice geometry, nontrivial band topology and
correlations yields rich quantum states of matter in Kagome systems. A class of
recent Kagome metals, AV3Sb5 (A= K, Rb, Cs), exhibit a cascade of
symmetry-breaking transitions, involving 3Q chiral charge ordering, electronic
nematicity, roton pair density wave and superconductivity. The interdependence
among multiple competing orders suggests unconventional superconductivity, the
nature of which is yet to be resolved. Here, we report the electronic evidence
for chiral superconducting domains with boundary supercurrent, a smoking-gun of
chiral superconductivity, in intrinsic CsV3Sb5 akes. Magnetic field-free
superconducting diode effects are observed with its polarity modulated by
thermal histories, unveiling a spontaneous time-reversal-symmetry breaking
within dynamical order parameter domains in the superconducting phase.
Strikingly, the critical current exhibits double-slit superconducting
interference patterns, when subjected to external magnetic field. This is
attributed to the periodic modulation of supercurrent owing along chiral domain
boundaries constrained by fluxoid quantization. Our results provide the direct
demonstration of a time-reversal symmetry breaking superconducting order in
Kagome systems, opening a potential for exploring exotic physics, e.g. Majorana
zero modes, in this intriguing topological Kagome system.Comment: 16 pages,13 figure
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