Abstract
We report on high-resolution observations of recurrent fan-like jets by the Goode Solar Telescope in multiple wavelengths inside a sunspot group. The dynamics behavior of the jets is derived ...from the H
α
line profiles. Quantitative values for one well-identified event have been obtained, showing a maximum projected velocity of 42 km s
−1
and a Doppler shift of the order of 20 km s
−1
. The footpoints/roots of the jets have a lifted center on the H
α
line profile compared to the quiet Sun, suggesting a long-lasting heating at these locations. The magnetic field between the small sunspots in the group shows a very high resolution pattern with parasitic polarities along the intergranular lanes accompanied by high-velocity converging flows (4 km s
−1
) in the photosphere. Magnetic cancellations between the opposite polarities are observed in the vicinity of the footpoints of the jets. Along the intergranular lanes horizontal magnetic field around 1000 G is generated impulsively. Overall, all the kinetic features at the different layers through the photosphere and chromosphere favor a convection-driven reconnection scenario for the recurrent fan-like jets and evidence a site of reconnection between the photosphere and chromosphere corresponding to the intergranular lanes.
A general photocatalytic substrate‐controlled chemodivergent strategy starting from monoalkynes with polyhalomethanes such as BrCCl3 and CBr4 was develop, enabling Kharasch‐type addition/nucleophilic ...substitution cascade to selectively produce α‐gem‐dihalovinyl ketones and chromen‐2‐ones with moderate to good yields. Use of monoalkynes without additional nucleophilic sites furnished α‐gem‐dihalovinyl ketones through a Kharasch‐type addition and intermolecular allylic substitution cascade whereas the latter transformation of 2‐ethynylphenols allowed the full breaking of carbon‐halogen bonds of BrCX3 to access functionalized chromen‐2‐ones. The late‐stage application of these resulting α‐gem‐dihalovinyl ketones demonstrates the versatility of their derivatization.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this article, an XY parallel nanomanipulator with multiple actuation modes (PNM) is proposed, analyzed, and tested. Arising from the parallel mechanism of a machine tool, the PNM is featured with ...multiple actuation modes and configurable parallel chains. Analytical models with different approaches are established to compressively understand the presented PNM. Workspace distribution and reachability are analyzed under different actuation modes in a detail manner. The models also reveal the combined effect of multiple modes and the influence of chain arrangement on the achieved workspace and the stiffness property. Dynamic analysis indicates that PNM is with high bandwidth as well. Finite element analysis and experiments were carried out to verify the above analysis results. Finally, a compound decoupled controller is especially designed for PNM to achieve the decoupling motion control. Planar trajectory-tracking tests demonstrate the feasibility and effectiveness of proposed control method.
With the widespread global application of BeiDou navigation, BeiDou B1C signaling based on Quadrature Multiplexed Binary Offset Carrier (QMBOC) modulation is expected to be extensively used in urban ...environments due to its wider signal bandwidth, smaller code pseudorange measurement errors, and stronger multipath capabilities. Despite offering higher positioning accuracy and secondary modulation characteristics of the BeiDou, B1C signals introduce the challenge of multiple peaks in the autocorrelation function. This leads to phase ambiguity during signal acquisition and tracking, resulting in positioning deviations of tens or even hundreds of meters. In urban environments, such deviations give rise to significant practical application issues. To address this problem, we have designed a multi-loop structure for the synchronous tracking of B1C signals and proposed a multi-peak phase-deblurring algorithm specifically tailored for the BeiDou B1C signal in urban environments. This algorithm considers the coupling relationship between the code and the carrier loops, and by matching the structural design of multiple loops, it achieves a precise and unambiguous phase estimation of the pseudocode, enabling the stable tracking of the entire loop for the BeiDou B1C signal. Simulation and actual testing demonstrate that the algorithm exhibits an error less than 0.03 for chip intervals when the signal-to-noise ratio is greater than −20 dB. Additionally, the accuracy can be improved by adjusting the set conditions, making it suitable for urban environments.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this article, we study the existence of solutions for the Dirac system
where
is an
-dimensional compact Riemannian spin manifold,
are spinors,
is the Dirac operator on
, and the fiber preserving ...map
is a real-valued superquadratic function of class
with subcritical growth rates. Two existence results of nontrivial solutions are obtained via Galerkin-type approximations and linking arguments.
Nonalcoholic fatty liver disease (NAFLD) is a common liver disease that ranges from simple steatosis to nonalcoholic steatohepatitis (NASH). So far, the underlying mechanism remains poorly ...understood. Here, we show that hepatic carboxylesterase 2 (CES2) is markedly reduced in NASH patients, diabetic db/db mice, and high‐fat diet (HFD)‐fed mice. Restoration of hepatic CES2 expression in db/db or HFD‐fed mice markedly ameliorates liver steatosis and insulin resistance. In contrast, knockdown of hepatic CES2 causes liver steatosis and damage in chow‐ or Western diet‐fed C57BL/6 mice. Mechanistically, we demonstrate that CES2 has triglyceride hydrolase activity. As a result, gain of hepatic CES2 function increases fatty acid oxidation and inhibits lipogenesis, whereas loss of hepatic CES2 stimulates lipogenesis by inducing endoplasmic reticulum stress. We further show that loss of hepatic CES2 stimulates lipogenesis in a sterol regulatory element‐binding protein 1 (SREBP‐1)‐dependent manner. Finally, we show that hepatocyte nuclear factor 4 alpha (HNF‐4α) plays a key role in controlling hepatic CES2 expression in diabetes, obesity, or NASH. Conclusion: CES2 plays a protective role in development of NAFLD. Targeting the HNF‐4α/CES2 pathway may be useful for treatment of NAFLD. (Hepatology 2016;63:1860‐1874)
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Enveloped virus usually utilizes the receptor-mediated multiple endocytic routes to enter permissive host cells for successful infection. Cellular receptors are cell surface molecules, either by ...helping viral attachment to cell surface followed by internalization or by triggering antiviral immunity, participate in the viral-host interaction. White spot syndrome virus (WSSV), the most lethally viral pathogen with envelope and double strand DNA genome in crustacean farming, including shrimp and crayfish, has been recently found to recruit various endocytic routes for cellular entry into host cells. Meanwhile, other than the typical pattern recognition receptors for recognition of WSSV, more and more putative cellular receptors have lately been characterized to facilitate or inhibit WSSV entry. In this review, recent findings on the endocytosis-dependent WSSV entry, viral entry mediated by putative cellular receptors, the molecular interplay between WSSV and cellular receptors, and the following anti-WSSV immunity are summarized and discussed, which may provide us a better understanding of the WSSV pathogenesis and further possible antiviral control of white spot disease in crustacean farming.
•Recent findings on the putative cellular receptors-mediated recognition and entry of WSSVare summarized.•Advances in cellular receptors-mediated sensing of WSSV and triggering of anti-WSSV immunity are discussed.•IgSF receptors, Integrin, Laminin receptor, Chitin-binding protein and glucose transporter 1 mediate WSSV entry.•Toll-like receptors, C-type lectins and Scavenger receptors sense WSSV and trigger antiviral immunity.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A comprehensive understanding of the geometrical form of the concrete mesostructure is important because it is associated with the complex and random mechanical behavior of the concrete. There is ...still uncertainty about how to characterize the geometrical form of the concrete mesostructure and its effect on the observed macroscopic behavior. The coarse aggregate content and fractal dimension were used in this study to indicate the geometrical form of concrete at the mesolevel. Taking the mechanical parameters measured in experiments, a group of mesomodels with various fractal dimensions and coarse aggregate contents was simulated by using the random fractal modeling method and then was studied and discussed. The analytical solution, simulation, and experimental data all suggested that the elastic modulus increased with the increasing coarse aggregate content. Meanwhile, the fractal dimension can cause the elastic modulus to decline slightly. The comprehensive consideration of both fractal geometry and classical Euclidean geometry can aid in predicting the macroscopic behavior of concrete.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Display omitted
Photocatalytic performance of polymeric carbon nitride (CN) is primarily restricted by limited light utilization and poor charge separation efficiency. To this end, skeleton ...modification strategy was adopted by attaching thiophene ring and polar nickel complex (NiL) onto CN. The obtained bifunctionalized carbon nitride (TCN-NiL) displayed obviously elevated optical absorption and photoexcited charge separation efficiency. The NiL, with polar structure, plays as active sites like cocatalyst thus exhibited platinum-like H2 evolution activity from water splitting under visible light. The optimized photocatalytic H2 generation rate over TCN-NiL reached 136.7 μmol·h−1 without any cocatalyst, the highest rate reported so far in noble-metal-free CN-based catalysts, which is 5 times of that of CN loaded with 3 wt% Pt. Additionally, the maximum wavelength of performing H2 production capacity over TCN-NiL extends to 550 nm from 450 nm of CN, suggesting an excellent visible light absorption ability. This work provides a way for modifying CN to enhance the photocatalytic activities in a noble metal free system.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
You have reached the maximum number of search results that are displayed.
For better performance, the search offers a maximum of 1,000 results per query (or 50 pages if the option 10/page is selected).
Consider using result filters or changing the sort order to explore your results further.
PDF
