3,484 research outputs found
Engineering planar transverse domain walls in biaxial magnetic nanostrips by tailoring transverse magnetic fields with uniform orientation
Designing and realizing various magnetization textures in magnetic
nanostructures are essential for developing novel magnetic nanodevices in
modern information industry. Among all these textures, planar transverse domain
walls (pTDWs) are the simplest and the most basic, which make them popular in
device physics. In this work, we report the engineering of pTDWs with arbitrary
tilting attitude in biaxial magnetic nanostrips by transverse magnetic field
profiles with uniform orientation but tunable strength distribution. Both
statics and axial-field-driven dynamics of these pTDWs are analytically
investigated. It turns out that for statics these pTDWs are robust again
disturbances which are not too abrupt, while for dynamics it can be tailored to
acquire higher velocity than Walker's ansatz predicts. These results should
provide inspirations for designing magnetic nanodevices with novel
one-dimensional magnetization textures, such as 360 walls, or even
two-dimensional ones, for example vortices, skyrmions, etc.Comment: 14 pages, 3 figure
The largest virialized dark halo in the universe
Using semi-analytic approach, we present an estimate of the properties of the
largest virialized dark halos in the present universe for three different
scenarios of structure formation: SCDM, LCDM and OCDM models. The resulting
virial mass and temperature increase from the lowest values of and 9.8 keV in OCDM, the mid-range values of and 31 keV in LCDM, to the highest values of
, 65 keV in SCDM. As compared with the
largest virialized object seen in the universe, the richest clusters of
galaxies, we can safely rule out the OCDM model. In addition, the SCDM model is
very unlikely because of the unreasonably high virial mass and temperature. Our
computation favors the prevailing LCDM model in which superclusters may be
marginally regarded as dynamically-virialized systems.Comment: 5 pages, Accepted by Int. J. Mod. Phys.
Investigation of Maillard reaction involvement in the steam processing of Panax Notoginseng root
Purpose: To explore the possible mechanism of Maillard reaction (MR) involvement in the steam processing of Panax notoginseng (PN) root.Methods: PN root was soaked in water for 24 h and then steamed at 100 °C using an autoclave for 1, 2, 3, 4, 5 and 6 h, respectively. Several indicators associated with MR during steam processing were measured. The pH and absorbance at 420 nm (A420) of samples were measured using a pH meter and an ultraviolet-visible spectrophotometer, respectively. The contents of 5-hydroxy-methyl-furfural (5-HMF) and sugars were determined by high performance liquid chromatography (HPLC) while amino acids were evaluated using an automatic amino acid analyzer.Results: During PN root steam processing (0 - 6 h), pH value gradually decreased from 6.35 ± 0.02 to 5.88 ± 0.03 while A420 value gradually increased from 0.23 ± 0.01 to 0.44 ± 0.02. The levels of reducing sugars (maltose and glucose) and amino acids (aspartic acid, glutamate, cysteine, lysine and arginine) in PN root decreased after steaming for 6 h. However, the content of 5-HMF in PN root increased with increase in steaming time.Conclusion: The results indicate that MR occurs during steam processing of PN root, and the reaction mechanism might be closely related to the reaction between the reducing sugars and amino acids.Keywords: Panax notoginseng, Steaming, Reducing sugars, Amino acids, Maillard reactio
Over-expression of the Hybrid Aspen Homeobox PttKN1 Gene in Red Leaf Beet Induced Altered Coloration of Leaves
PttKN1 (Populus tremula × tremuloides KNOTTED1) gene belongs to the KNOXI gene family. It plays an important role in plant development, typically in meristem initiation, maintenance and organogenesis, and potentially in plant coloration. To investigate the gene functions further, it was introduced into red leaf beet by the floral dip method mediated via Agrobacterium tumefaciens. The transformants demonstrated typical phenotypes as with other PttKN1 transformants. These alterations were very different from the morphology of the wild type. Among them, morphological modification of changed color throughout the entire plant from claret of wild type to yellowish green was the highlight in those transgenic PttKN1-beet plants. The result of spraying selection showed that the PttKN1-beet plants had kanamycin resistance. PCR assay of the 35S-Promoter, NPTII and PttKN1 gene, PCR-Southern analysis of the NPTII and PttKN1 gene showed that the foreign PttKN1 gene had successfully integrated into the genome of beet plant. Furthermore, the results of RT-PCR analysis showed that the gene was ectopic expressed in transgenic plants. These data suggested that there is a correlation between the ectopic expression of PttKN1 gene and morphological alterations of beet plants. Pigment content assay showed that betaxanthins concentrations shared little difference between wild type and transgenic lines, while betacyanins content in transgenic plants was sharply decreased, indicating that the altered plant coloration of the transgenic beet plants may be caused by the changed betacyanins content. The tyrosinase study suggested that the sharply decreased of betacyanins content in transgenic plants was caused via the decreased tyrosinase level. Therefore, the reason for the altered plant coloration may be due to partial inhibition of betacyanin biosynthesis that was induced via the pleiotropic roles of PttKN1 gene
Maillard reaction induces changes in saccharides and amino acids during stir-baking of areca nuts
Purpose: To investigate changes in saccharides and amino acids induced by Maillard reaction (MR) during stir-baking of areca nuts (AN).Methods: The pH of aqueous extracts of AN and charred AN (CAN) were measured by a pH meter, and their absorbances at 420 nm were read in an ultraviolet-visible (UV-VIS) spectrophotometer. Changes in saccharides and amino acids were evaluated by high performance liquid chromatography (HPLC) and automated amino acid analyzer, respectively.Results: The pH of AN (5.85 ± 0.09) was lower than that of CAN (5.25 ± 0.04). Stir-baking significantly increased the A420 value of AN (0.32 ± 0.01 to 0.62 ± 0.02 (CAN). In addition, the contents of reducing saccharides (fructose and glucose) and free amino acids (serine, lysine, arginine and proline) were significantly decreased in the stir-baked CAN compared with AN.Conclusion: MR, during stir-baking of AN, decreases levels of free amino acids and reducing sugars due probably to the reaction between saccharides and amino acids.Keywords: Areca nut, Stir-baking, Maillard reaction, Reducing sugars, Free amino acid
Synchronization of chaotic delayed systems via intermittent control and its adaptive strategy
In this paper the problem of synchronization for delayed chaotic systems is considered based on aperiodic intermittent control. First, delayed chaotic systems are proposed via aperiodic adaptive intermittent control. Next, to cut down the control gain, a new generalized intermittent control and its adaptive strategy is introduced. Then, by constructing a piecewise Lyapunov auxiliary function and making use of piecewise analysis technique, some effective and novel criteria are obtained to ensure the global synchronization of delayed chaotic systems by means of the designed control protocols. At the end, two examples with numerical simulations are provided to verify the effectiveness of the theoretical results proposed scheme
Weakly-supervised Micro- and Macro-expression Spotting Based on Multi-level Consistency
Most micro- and macro-expression spotting methods in untrimmed videos suffer
from the burden of video-wise collection and frame-wise annotation.
Weakly-supervised expression spotting (WES) based on video-level labels can
potentially mitigate the complexity of frame-level annotation while achieving
fine-grained frame-level spotting. However, we argue that existing
weakly-supervised methods are based on multiple instance learning (MIL)
involving inter-modality, inter-sample, and inter-task gaps. The inter-sample
gap is primarily from the sample distribution and duration. Therefore, we
propose a novel and simple WES framework, MC-WES, using multi-consistency
collaborative mechanisms that include modal-level saliency, video-level
distribution, label-level duration and segment-level feature consistency
strategies to implement fine frame-level spotting with only video-level labels
to alleviate the above gaps and merge prior knowledge. The modal-level saliency
consistency strategy focuses on capturing key correlations between raw images
and optical flow. The video-level distribution consistency strategy utilizes
the difference of sparsity in temporal distribution. The label-level duration
consistency strategy exploits the difference in the duration of facial muscles.
The segment-level feature consistency strategy emphasizes that features under
the same labels maintain similarity. Experimental results on three challenging
datasets -- CAS(ME), CAS(ME), and SAMM-LV -- demonstrate that MC-WES is
comparable to state-of-the-art fully-supervised methods
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