23 research outputs found
Topological plasma transport from a diffusion view
Recent studies have identified plasma as a topological material. Yet, these
researches often depict plasma as a fluid governed by electromagnetic fields,
i.e., a classical wave system. Indeed, plasma transport can be characterized by
a unique diffusion process distinguished by its collective behaviors. In this
work, we adopt a simplified diffusion-migration method to elucidate the
topological plasma transport. Drawing parallels to the thermal
conduction-convection system, we introduce a double ring model to investigate
the plasma density behaviors in the anti-parity-time reversal (APT) unbroken
and broken phases. Subsequently, by augmenting the number of rings, we have
established a coupled ring chain structure. This structure serves as a medium
for realizing the APT symmetric one-dimensional (1D) reciprocal model,
representing the simplest tight-binding model with a trivial topology. To
develop a model featuring topological properties, we should modify the APT
symmetric 1D reciprocal model from the following two aspects: hopping amplitude
and onsite potential. From the hopping amplitude, we incorporate the
non-reciprocity to facilitate the non-Hermitian skin effect, an intrinsic
non-Hermitian topology. Meanwhile, from the onsite potential, the quasiperiodic
modulation has been adopted onto the APT symmetric 1D reciprocal model. This
APT symmetric 1D Aubry-Andr\'e-Harper model is of topological nature.
Additionally, we suggest the potential applications for these diffusive plasma
topological states. This study establishes a diffusion-based approach to
realizing topological states in plasma, potentially inspiring further
advancements in plasma physics.Comment: This letter has been published on Chinese Physics Letters as an
express letter.Comments are welcome
Controlling mass and energy diffusion with metamaterials
Diffusion driven by temperature or concentration gradients is a fundamental
mechanism of energy and mass transport, which inherently differs from wave
propagation in both physical foundations and application prospects. Compared
with conventional schemes, metamaterials provide an unprecedented potential for
governing diffusion processes, based on emerging theories like the
transformation and the scattering cancellation theory, which enormously
expanded the original concepts and suggest innovative metamaterial-based
devices. We hereby use the term ``diffusionics'' to generalize these remarkable
achievements in various energy (e.g., heat) and mass (e.g., particles and
plasmas) diffusion systems. For clarity, we categorize the numerous studies
appeared during the last decade by diffusion field (i.e., heat, particles, and
plasmas) and discuss them from three different perspectives: the theoretical
perspective, to detail how the transformation principle is applied to each
diffusion field; the application perspective, to introduce various intriguing
metamaterial-based devices, such as cloaks and radiative coolers; and the
physics perspective, to connect with concepts of recent concern, such as
non-Hermitian topology, nonreciprocal transport, and spatiotemporal modulation.
We also discuss the possibility of controlling diffusion processes beyond
metamaterials. Finally, we point out several future directions for diffusion
metamaterial research, including the integration with artificial intelligence
and topology concepts.Comment: This review article has been accepted for publication in Rev. Mod.
Phy
Gibberellin Increases the Bud Yield and Theanine Accumulation in Camellia sinensis (L.) Kuntze
Tea (Camellia sinensis) is one of the most important cash crops in the world. Theanine, as an important amino acid component in tea, is a key quality index for excellent tea quality and high economic value. People increase theanine accumulation in tea mainly through the application of nitrogen fertilizer, shading and pruning. However, these methods are not effective. In this study, we treated tea buds with a 100 ΌM solution of GA3 containing 1Ⱐtween-20, investigated the effects of GA3 on theanine accumulation, bud yield, chlorophyll fluorescence parameters and expression level of theanine biosynthesis pathway genes in tea plant by qPCR, LC-MS/MS etc. Results showed that change trends of theanine and GA3 was extremely positively correlated with each other. Exogenous GA3 upregulated the expression level of theanine biosynthesis pathway genes, caused an increase of theanine content (mg·g-1) by 27% in tea leaves compared with Mock, and accelerated the germination of buds and elongation of shoots, which lead to a significant increase of tea yield by 56% (w/w). Moreover, the decrease of chlorophyll contents, photochemical quenching coefficient (qP) and relative electron transport rate (rETR) under GA3 treatment suggested that GA3 reduced photosynthesis in the tender tea leaves, indicating that the decline of carbon assimilation in tea plants was conducive to the nitrogen metabolism, and it was beneficial to the accumulation of theanine. This study provided a new technical and theoretical support for the precise control of tea quality components and phenophase
Anthocyanins of the genus of Hosta and their impacts on tepal colors
Currently flower color in Hosta is limited to purple and white with some variation across species and cultivars in patterning of the two colors. This study was undertaken to determine the contributions of anthocyanins to current Hosta flower colors and to investigate the potential for increasing color diversity. Eighty-six hostas (6 species and 80 cultivars) were used in this study to investigate the composition and content of anthocyanins by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) and high-performance liquid chromatographic with electro spray ionization and mass spectrometry (HPLC-ESI-MS). The results showed that the color variation was low in the tepals of the genus of Hosta. Nine anthocyanins were initially identified using a typical purple cultivar (H. 'Nakaimo') and a white species (Hosta montana) The anthocyanins were delphinidin 3,5-O-diglucoside (Dp3G5G), cyanidin 3,5-O-diglucoside(Cy3G5G), petunidin 3,5-O-diglucoside (Pt3G5G), peonidin 3-O-rutinoside-5-O-glucoside (Pn3Ru5G), malvidin 3-O-rutinoside-5-O-glucoside (Mv3Ru5G), malvidin 3,5-O-diglucoside (Mv3G5G), petunidin 3-O-rutinoside (Pt3Ru), peonidin 3-O-rutinoside (Pn3Ru) and malvidin 3-O-rutinoside (Mv3Ru). Anthocyanin types and content were different between the purple flowered hostas (PFH) and the white flowered hostas (WFH, including white flower with purple spots or streaks): PFH had higher levels of anthocyanins and were correlated with the pigments Mv3Ru5G, Mv3G5G, Pt3G5G and Dp3G5G; WFH had lower levels of anthocyanins and were correlated with the pigments Pt3Ru, Pn3Ru, Mv3Ru and Pn3Ru5G. The dominance of Mv3G5G and Mv3Ru5G was responsible for flowers of simplex purple. Path analysis showed that Mv3G5G had the highest direct effect on lightness (11, and color balance (a* and b*), while Pt3G5G had the highest direct effect on saturation (C*). (C) 2012 Elsevier B.V. All rights reserved
Dynamic quantitative trait locus analysis of seed vigor at three maturity stages in rice.
Seed vigor is an important characteristic of seed quality. In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed vigor, including the germination potential, germination rate, germination index and time for 50% of germination, at 4 (early), 5 (middle) and 6 weeks (late) after heading in two years. A total of 24 additive and 9 epistatic quantitative trait loci (QTL) for seed vigor were identified using QTL Cartographer and QTLNetwork program respectively in 2012; while 32 simple sequence repeat (SSR) markers associated with seed vigor were detected using bulked segregant analysis (BSA) in 2013. The additive, epistatic and QTL Ă development interaction effects regulated the dry maturity developmental process to improve seed vigor in rice. The phenotypic variation explained by each additive, epistatic QTL and QTL Ă development interaction ranged from 5.86 to 40.67%, 4.64 to 11.28% and 0.01 to 1.17%, respectively. The QTLs were rarely co-localized among the different maturity stages; more QTLs were expressed at the early maturity stage followed by the late and middle stages. Twenty additive QTLs were stably expressed in two years which might play important roles in establishment of seed vigor in different environments. By comparing chromosomal positions of these stably expressed additive QTLs with those previously identified, the regions of QTL for seed vigor are likely to coincide with QTL for grain size, low temperature germinability and seed dormancy; while 5 additive QTL might represent novel genes. Using four selected RILs, three cross combinations of seed vigor for the development of RIL populations were predicted; 19 elite alleles could be pyramided by each combination
Sexâspecific difference in the relationship between body fat percentage and arterial stiffness: Results from Fuzhou study
Abstract Obesity and overweight are closely related to cardiovascular mortality. Arterial stiffness is one of the important risks for cardiovascular diseases and is strongly related with the cardiovascular mortality. However, the relationship between obesity and arterial stiffness is still controversial. A crossâsectional study was performed to examine the relationship of body fat percentage (BFP), an indicator of obesity, with carotidâfemoral pulse wave velocity (cfPWV) in 2603 subjects (aged 58.62 ± 11.27 years, male 71.07%, hypertension 64.89%). All participants were divided into four groups according to the gender and the presence of arterial stiffening based on a value â„10 m/s of cfPWV(group1 : male with cfPWV <10 m/s, group2 : male with cfPWV â„10 m/s, group3 : female with cfPWV <10 m/s, group4 : female with cfPWV â„10 m/s). Body weight, height, waist circumference, blood pressure were measured and clinical biochemical tests were recorded. cfPWV was measured using a nonâinvasive automatic device (Complior Analysis, France). BFP were calculated by CUNâBAE equation. The level of cfPWV was significantly increased with the increasing trend of BFP in both males and females. Stepwise multiple regression analysis revealed that SBP, DBP, HR, Hcy, BFP, FPG were independent associated with cfPWV in females and SBP, eGFR, FPG, BFP, DBP were independent associated with cfPWV in males. In the subgroups stratified by age, BFP was correlated with cfPWV only in females over 60 years old, but not in female those aged under 60 years old and males. In addition to the age and blood pressure, BFP was one of important predictor of arterial stiffening special in females aged over 60 years old
Abrupt warming of the equatorial intermediate Pacific during Heinrich Stadial 1
The Pacific intermediate water is essential for global ocean heat storage and transfer and connected to the higher latitude sea areas. Its thermohaline evolution and relationship to high latitudes on millennium scales, however, are both poorly understood. In this study, we used sediment core KX22â4 in the western equatorial Pacific to reconstruct the thermohaline and ÎŽ13C variations in the intermediate water over the past 28,000âŻyears based on Mg/Ca, ÎŽ18O and ÎŽ13C measurements of deep dwelling planktonic foraminiferal species. The results show that during Heinrich Stadial 1, the temperature of intermediate water rapidly increased by roughly 6âŻÂ°C and was simultaneous with the Southern Ocean surface water, carrying a typical Antarctic signature along with the salter and reduced ÎŽ13C signals. The Southern Hemisphere climatic development and the advection of the thermal anomaly into the tropical intermediate Pacific via the Southern Ocean intermediate water are thought to be closely coupled
The positive alleles of additive QTLs which stably expressed in two years in the selected RILs.
a<p>GP, Germination potential; GR, germination rate; GI, germination index; T<sub>50</sub>, time for 50% of germination;</p>b<p>The additive QTLs were detected in both years;</p>c<p>+ The positive allele were detected in the selected RIL.</p><p>The positive alleles of additive QTLs which stably expressed in two years in the selected RILs.</p
Phenotype of high and low vigor bulks in seeds collected at 4, 5 and 6 weeks after heading in 2013.
<p>(a) germination potential (%); (b) germination rate (%); (c) germination index; (d) time for 50% of germination (d); ** significance at the 1% level according to Student's <i>t</i> test.</p
Additive QTLs for seed vigor identified using single-maturity phenotypic values by QTL Cartographer in 2012.
a<p>Seeds were collected at 4, 5 and 6 weeks after heading;</p>b<p>GP, Germination potential; GR, germination rate; GI, germination index; T<sub>50</sub>, time for 50% of germination;</p>c<p>Chromosome on which the QTL was located;</p>d<p>Additive effect is the effect of substituting an IR26 allele for a Jiucaiqing allele; Its positive value indicates that IR26 has the positive allele; The case of negative values is just the opposite;</p>e<p>Variation explained by each putative QTL.</p><p>Additive QTLs for seed vigor identified using single-maturity phenotypic values by QTL Cartographer in 2012.</p