Investigation on Doppler imaging and chromospheric activity of the young dwarf LQ Hya based on high-resolution spectroscopy

This study is supported by the National Natural Science Foundation of China under grants Nos. 10373023, 10773027, U1531121, 11603068, and 11903074. We acknowledge the science research grant from the China Manned Space Project with NO. CMS-CSST-2021-B07. This work is partially supported by the Open Project Program of the Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences.We have obtained four Doppler images of LQ Hya in 2005 November–December, 2006 November–December, 2008 November, and 2014 January–February using high-resolution spectra obtained at three different observing sites. All of the surface maps show that the spots of LQ Hya are in bimodal distribution, i.e., in polar/high-latitude and low-latitude regions. Its chromospheric activity indicators exhibit obvious rotational modulations that are correlated with the simultaneous light curves, except in 2008. The correspondence between the maximum value of chromospheric emission and the low-latitude spot of new reconstructed image is clear, which indicates that both of them are driven by homologous magnetic field. The variation of Hα emission over a long time span suggests that the chromospheric plages may implicate a similar active cycle as photospheric spots.Publisher PDFPeer reviewe

Pro-inflammatory miR-223 mediates the cross-talk between the IL23 pathway and the intestinal barrier in inflammatory bowel disease

Genes that showed greater than four-fold upregulation in IBD. (XLSX 28 kb

The first Doppler images of the eclipsing binary SZ Piscium

We present the first Doppler images of the active eclipsing binary system SZ Psc, based on the high-resolution spectral data sets obtained in 2004 November and 2006 September–December. The least-squares deconvolution technique was applied to derive high signal-to-noise profiles from the observed spectra of SZ Psc. Absorption features contributed by a third component of the system were detected in the LSD profiles at all observed phases. We estimated the mass and period of the third component to be about 0.9 M⊙ and 1283 ± 10 d, respectively. After removing the contribution of the third body from the least-squares deconvolved profiles, we derived the surface maps of SZ Psc. The resulting Doppler images indicate significant star-spot activities on the surface of the K subgiant component. The distributions of star-spots are more complex than that revealed by previous photometric studies. The cooler K component exhibited pronounced high-latitude spots as well as numerous low- and intermediate-latitude spot groups during the entire observing seasons, but did not show any large, stable polar cap, different from many other active RS CVn-type binaries

Synthesis and antibacterial activity against ralstonia solanacearum for novel hydrazone derivatives containing a pyridine moiety

<p>Abstract</p> <p>Background</p> <p><it>Ralstonia solanacearum</it>, one of the most important bacterial diseases on plants, is a devastating, soil-borne plant pathogen with a global distribution and an unusually wide host range. In order to discover new bioactive molecules and pesticides acting on tobacco bacterial wilt, we sought to combine the active structure of hydrazone and pyridine together to design and synthesize a series of novel hydrazone derivatives containing a pyridine moiety.</p> <p>Results</p> <p>A series of hydrazone derivatives containing a pyridine moiety were synthesized. Their structures were characterized by ¹H-NMR, ¹³C-NMR, IR, and elemental analysis. The preliminary biological activity tests showed that compound 3e and 3g exhibited more than 80% activity against <it>Ralstonia solanacearum </it>at 500 mg/L, especially compound 3g displayed relatively good activity to reach 57.0% at 200 mg/L.</p> <p>Conclusion</p> <p>A practical synthetic route to hydrazone derivatives containing a pyridine moiety by the reaction of intermediates 2 with different aldehydes in ethanol at room temperature using 2-chloronicotinic acid and 2-amino-5-chloro-3-methylbenzoic acid as start materials is presented. This study suggests that the hydrazone derivatives containing a substituted pyridine ring could inhibit the growth of <it>Ralstonia solanacearum</it>.</p

Relaxation behavior study on PET and PET/Ti

The relaxation behavior of neat PET and PET/Ti3N4 nanocomposites was investigated by means of internal friction. The temperature dependence of internal friction exhibit two relaxation peaks i.e. α and β peaks, and both heights of the peaks first increase and then decrease with increasing concentration of Ti3N4 nanoparticles. However, the peak temperature and activation energy for α and β peaks show different change trends with increasing concentration of Ti3N4 nanoparticles, which associated with the changes of nucleation and crystallization of the PET due to the addition of nanoparticles. Further increasing the concentration of Ti3N4 nanoparticles, a third peak, α′ located at the temperature between α and β peaks appears in the PET/Ti3N4 nanocomposites, which may be a physical aging peak

A Bibliometric Analysis of Food-Energy-Water Nexus: Progress and Prospects

Food, energy and water are important basic resources that affect the sustainable development of a region. The influence of food–energy–water (FEW) nexus on sustainable development has quickly become a frontier topic since the Sustainable Development Goals (SDGs) were put forward. However, the overall context and core issues of the FEW nexus contributions to SDGs are still unclear. Using co-citation analysis, this paper aims to map the knowledge domains of FEW nexus research, disentangles its evolutionary context, and analyzes the core issues in its research, especially the progress of using quantitative simulation models to study the FEW nexus. We found that (1) studies within the FEW nexus focused on these following topics: correlation mechanisms, influencing factors, resource footprints, and sustainability management policies; (2) frontier of FEW studies have evolved from silo-oriented perspective on single resource system to nexus-oriented perspective on multiple systems; (3) quantitative research on the FEW nexus was primarily based on spatiotemporal evolution analysis, input–output analysis and scenario analysis; (4) the resource relationship among different sectors was synergies and tradeoffs within a region. In general, current research still focuses on empirical data, mostly qualitative and semiquantitative analyses, and there is a lack of research that can systematically reflect the temporal and spatial contribution of the FEW nexus to multiple SDGs. We believe that future research should focus more on how FEW nexus can provide mechanistic tools for achieving sustainable development

Ball Milling-Induced Plate-like Sub-microstructured Iron for Enhancing Degradation of DDT in a Real Soil Environment

The remediation of soil contaminated by 1,1,1-trichloro-2,2-bis­(4-chlorophenyl) ethane (DDT) has been a challenge. In this paper, the degradation performances of the ball milling-induced plate-like sub-microstructured zero valent iron (SMZVI) to DDT in a real soil environment is studied. It has been found that such SMZVI exhibits much higher degradation performances to DDT in soil than commercial ZVI powders under acidic conditions. More than 95% DDT could be degraded within 80 min in the 5 ppm DDT-contaminated soil with addition of 50 mg g^–1 SMZVI, which is much better than the previously reported results. The time-dependent DDT removal amount can be well described by the pseudo first-order kinetic model. Further experiments have revealed that the ZVI dosages, surfactant’s and acidic additions, and the weight ratio of soil-to-water in the slurries are important to DDT degradation, and the degradation products were mainly DDD (a product with less chlorine). An acid-assisted ZVI-induced reductive dechlorination process is proposed, which can well explain the DDT degradation behaviors in soil and the influence from the other factors. This work not only deepens the understanding of DDT degradation in soils based on ZVI but also demonstrates that the SMZVI could be a promising material for DDT degradation in real environments

Ni/carbon aerogels derived from water induced self-assembly of Ni-MOF for adsorption and catalytic conversion of oily wastewater

Herein, we reported a facile tactics for the fabrication of Ni nanoparticles embedded carbon (Ni/C) aerogels via water induced self-assembly of Ni-MOFs, and followed by pyrolysis carbonization under nitrogen atmosphere. The water induced assembly mechanism of Ni-MOF hydrogel was investigated by adjusting the ratio of water/ethanol and molecular dynamics simulation. Utilizing the nanofibers with hierarchical porous structures, the Ni/C aerogels with low density (27.9 mg/cm), superhydrophobic (163.1 of water contact angle), high elasticity (8.94 MPa at 70% of strain) and large specific surface areas (144.6 m/g) were fabricated, achieving remarkable adsorption efficiency (1903% to 3899%) and cycling stability (15 cycles) for various oil and organic compounds. After oil adsorption, the Ni/C aerogels can be recycled by using extra magnetic field owing to the magnetic properties of metal Ni nanoparticles (14.4 nm size). More importantly, the Ni/C aerogels can be used as a catalyst to further convert the adsorbed organic compounds into high value-added chemicals in the aqueous phase via catalytic hydrogenation reaction. Specifically, nitrobenzene was completely converted into aniline and selective hydrogenation of furfural transferred to tetrahydrofurfuryl alcohol was achieved. Therefore, the multifunctional Ni/C aerogels could be used to kill two birds with one stone for advanced treatment of oily wastewater

Preparation and Characterization of Poly(butylene terephthalate)/Silica Nanocomposites

In this study, we presented a convenient, in situ polymerization route for the preparation of Poly (butylene terephthalate) (PBT)/silica nanocomposites, in which silica was not premodified. The nanocomposites were synthesized by in situ polymerization of terephthalic acid (TPA), 1,4-butanediol (BD) and silica. The structure of these nanocomposites were investigated by Fourier transform infrared (FTIR) and thermogravimetric analyses (TGA). The results show that PBT chains were successfully grafted onto the surface of silica. Transmission electron microscope (TEM) micrographs revealed that silica were homogeneously dispersed in PBT matrix at a size level of 10-20 net. The isothermal crystallization kinetics of pure PBT and PBT/silica nanocomposites were investigated by differential scanning calorimeter (DSC) and simulated by Avrami model. The existence of silica could lead to an acceleration of crystallization and enhance the thermal stability of PBT. According to dynamic mechanical analysis (DMA), the storage modulus of PBT/silica nanocomposites were markedly improved compared with pure PBT. POLYM. ENG. SCI., 49:799-.807, 2009. (c) 2009 Society of Plastics Engineer