304 research outputs found
Effects of Rashba spin-orbit coupling and a magnetic field on a polygonal quantum ring
Using standard quantum network method, we analytically investigate the effect
of Rashba spin-orbit coupling (RSOC) and a magnetic field on the spin transport
properties of a polygonal quantum ring. Using Landauer-Buttiker formula, we
have found that the polarization direction and phase of transmitted electrons
can be controlled by both the magnetic field and RSOC. A device to generate a
spin-polarized conductance in a polygon with an arbitrary number of sides is
discussed. This device would permit precise control of spin and selectively
provide spin filtering for either spin up or spin down simply by interchanging
the source and drain
Detection of small single-cycle signals by stochastic resonance using a bistable superconducting quantum interference device
We propose and experimentally demonstrate detecting small single-cycle and
few-cycle signals by using the symmetric double-well potential of a radio
frequency superconducting quantum interference device (rf-SQUID). We show that
the response of this bistable system to single- and few-cycle signals has a
non-monotonic dependence on the noise strength. The response, measured by the
probability of transition from initial potential well to the opposite one,
becomes maximum when the noise-induced transition rate between the two stable
states of the rf-SQUID is comparable to the signal frequency. Comparison to
numerical simulations shows that the phenomenon is a manifestation of
stochastic resonance.Comment: 5 pages 3 figure
(E)-2-[2-(4-Chlorobenzylidene)hydrazin-1-yl]-4-{[3-(dimethylazaniumyl)propyl]amino}quinazolin-1-ium bis(perchlorate)
In the title compound, C20H25ClN6
2+·2ClO4
−, the organic cation is roughly planar, as shown by the dihedral angle of 3.78 (3)° between the quinazoline and chlorophenyl rings. The quinazoline ring is itself approximately planar, with an average deviation of 0.018 (4) Å. The organic cation adopts an E configuration with respect to the C= N double bond of the hyrazinyl group. The (dimethylazaniumyl)propylamino side chain is disordered over two sets of sites with occupancies of 0.768 (10) and 0.232 (10). In the crystal, two cations and four anions are linked by strong N—H⋯O hydrogen bonds. Weak C—H⋯O hydrogen bonds exist among these aggregates
Interrelated Thermalization and Quantum Criticality in a Lattice Gauge Simulator
Gauge theory and thermalization are both foundations of physics and nowadays
are both topics of essential importance for modern quantum science and
technology. Simulating lattice gauge theories (LGTs) realized recently with
ultracold atoms provides a unique opportunity for carrying out a correlated
study of gauge theory and thermalization in the same setting. Theoretical
studies have shown that an Ising quantum phase transition exists in this
implemented LGT, and quantum thermalization can also signal this phase
transition. Nevertheless, it remains an experimental challenge to accurately
determine the critical point and controllably explore the thermalization
dynamics in the quantum critical regime due to the lack of techniques for
locally manipulating and detecting matter and gauge fields. Here, we report an
experimental investigation of the quantum criticality in the LGT from both
equilibrium and non-equilibrium thermalization perspectives by equipping the
single-site addressing and atom-number-resolved detection into our LGT
simulator. We accurately determine the quantum critical point agreed with the
predicted value. We prepare a state deterministically and study
its thermalization dynamics across the critical point, leading to the
observation that this state thermalizes only in the critical
regime. This result manifests the interplay between quantum many-body scars,
quantum criticality, and symmetry breaking.Comment: 6+4 pages, 4+7 figure
Assessing genetic diversity and population structure of Salix viminalis across Ergun and West Liao basin
L. is an important shrub that has potential for use as a bioenergy crop, for phytoremediation of heavy metal contaminated soil and sewage sludge treatment. It is mainly distributed in the northeast of China, but the species has not yet been used a resource here. We examined the genetic diversity and population structure of populations from the Ergun basin and West Liao basin using 20 microsatellite markers. A high level of genetic diversity (Nâ=â16.45, Hâ=â0.742) was detected for , and populations from the Ergun basin exhibited higher genetic diversity and private alleles numbers than the West Liao basin. The 12 populations could be divided into two clusters by both Bayesian analysis and UPGMA clustering which were consistent with the populations derived from the two basins. Moderate population differentiation (Fâ=â0.076) was shown in , and AMOVA analysis confirmed that most of the genetic variation (86.13%) was attributed to individual differences within populations, while 11.49% was attributed to differences between basins and 2.38% to differences within each basin. Significant correlations of F/(1âF) with log (geographic distance) among 12 populations (râ=â0.634, pâ<â0.00) and 10 populations within the Ergun basin (râ=â0.482, pâ=â0.0002) indicated that geographical distance was the principal factor influencing genetic structure. As most of genetic variation exist within populations, so protection measures should be focused on populations with higher genetic diversity and unique alleles, such as Tuli, Mordaga downstream, Zhadun1 and Genhe.Salix viminalisaeS. viminalisSTS. viminalisSTS
The regulatory mechanism of fungal elicitor-induced secondary metabolite biosynthesis in medical plants.
A wide range of external stress stimuli trigger plant cells to undergo complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Throughout evolution, endophytic fungi, an important constituent in the environment of medicinal plants, have known to form long-term stable and mutually beneficial symbiosis with medicinal plants. The endophytic fungal elicitor can rapidly and specifically induce the expression of specific genes in medicinal plants which can result in the activation of a series of specific secondary metabolic pathways resulting in the significant accumulation of active ingredients. Here we summarize the progress made on the mechanisms of fungal elicitor including elicitor signal recognition, signal transduction, gene expression and activation of the key enzymes and its application. This review provides guidance on studies which may be conducted to promote the efficient synthesis and accumulation of active ingredients by the endogenous fungal elicitor in medicinal plant cells, and provides new ideas and methods of studying the regulation of secondary metabolism in medicinal plants
Advances in automated tongue diagnosis techniques
This paper reviews the recent advances in a significant constituent of traditional oriental medicinal technology, called tongue diagnosis. Tongue diagnosis can be an effective, noninvasive method to perform an auxiliary diagnosis any time anywhere, which can support the global need in the primary healthcare system. This work explores the literature to evaluate the works done on the various aspects of computerized tongue diagnosis, namely preprocessing, tongue detection, segmentation, feature extraction, tongue analysis, especially in traditional Chinese medicine (TCM). In spite of huge volume of work done on automatic tongue diagnosis (ATD), there is a lack of adequate survey, especially to combine it with the current diagnosis trends. This paper studies the merits, capabilities, and associated research gaps in current works on ATD systems. After exploring the algorithms used in tongue diagnosis, the current trend and global requirements in health domain motivates us to propose a conceptual framework for the automated tongue diagnostic system on mobile enabled platform. This framework will be able to connect tongue diagnosis with the future point-of-care health system
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