Search

In multicellular eukaryotes, autophagy is a conserved process that delivers cellular components to the vacuole or lysosome for recycling during development and stress responses. Induction of autophagy activates AUTOPHAGY-RELATED PROTEIN 1 (ATG1) and ATG13 to form a protein kinase complex that initiates autophagosome formation. However, the detailed molecular mechanism underlying the regulation of this protein complex in plants remains unclear. Here, we determined that in Arabidopsis thaliana, the regulatory proteins 14-3-3λ and 14-3-3κ redundantly modulate autophagy dynamics by facilitating SEVEN IN ABSENTIA OF ARABIDOPSIS THALIANA (SINAT)-mediated proteolysis of ATG13a and ATG13b. 14-3-3λ and 14-3-3κ directly interacted with SINATs and ATG13a/b in vitro and in vivo. Compared to wild-type (WT), the 14-3-3λ 14-3-3κ double mutant showed increased tolerance to nutrient starvation, delayed leaf senescence, and enhanced starvation-induced autophagic vesicles. Moreover, 14-3-3s were required for SINAT1-mediated ubiquitination and degradation of ATG13a. Consistent with their roles in ATG degradation, the 14-3-3λ 14-3-3κ double mutant accumulated higher levels of ATG1a/b/c and ATG13a/b than the WT upon nutrient deprivation. Furthermore, the specific association of 14-3-3s with phosphorylated ATG13a was crucial for ATG13a stability and formation of the ATG1–ATG13 complex. Thus, our findings demonstrate that 14-3-3λ and 14-3-3κ function as molecular adaptors to regulate autophagy by modulating the homeostasis of phosphorylated ATG13.

Aerodynamic optimization of the airfoil is of great significance to the shape design for wind turbine blade. However, it is tough to calculate the aerodynamic forces of airfoil with random shape variations. In response to this challenge, a stochastic parameterized model based on uncertainty quantification method is proposed. And the influence of non-deterministic airfoil geometry caused by designed parameters on the aerodynamic characteristics is evaluated through the combination of sparse grid-based polynomial chaos (SGPC) and computational fluid dynamic (CFD) taking two airfoils at different Reynolds numbers as examples. OpenFOAM is employed as CFD solver and connected with the in-house stochastic parametric analysis code in a non-intrusive way. Finally, the aerodynamic responses of lift, drag, as well as the surface pressure coefficients are obtained, and the sensitivity of the lift and drag coefficients to the stochastic designed parameters are evaluated. It can be concluded that for the same type airfoil, the sensitive parameters after stall behavior are effected to some extent by increasing Reynolds number, that is, the impact of the maximum curvature index on pressure surface is weakened. As for two kinds of airfoils, S809 is sensitive to parameters near the maximum curvature of the airfoil and the trailing edge of the suction surface under attached flow, while convert to those near the leading edge and maximum curvature of suction face once stalled. FFA-W3-241 airfoil has no sensitivity factors in attached flow and features the same sensitive indicators after stall. These results will provide a reference for coarse-to-fine strategy in optimizing the sample library which is generally the first step of airfoil design process.

The Ho2Fe17-xSix (x=0.0, 0.1, 0.2, 0.3) alloys were prepared by arc melting and high energy ball milling method. The influence of the Si substitution on phase structure, morphology and electromagnetic parameters were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vector network analyzer (VNA), respectively. The results show that the Ho-Fe-Si particles are flaky after the ball milling. The minimum absorption peak frequency shifts towards a lower frequency region with the increasing of Si content. The minimum RL of Ho2Fe16.7Si0.3 reaches-42.96 dB at 9.76 GHz, and the frequency bandwidth of R

In this study, whether H9N2 influenza A virus (IAV) infection contributed to secondary Klebsiella pneumoniae infection was investigated. From post-infection onwards, clinical symptoms were monitored, examined and recorded daily for 11 days. As a result, no clinical signs were observed in the mice infected with single H9N2 IAV, implying that H9N2 IAV was less pathogenic to mice. Compared to single K. pneumonia infection, K. pneumoniae infection following H9N2 IAV infection exacerbates lung histopathological lesions and apoptosis, resulting in more severe diseases. Lung index of the mice with H9N2 IAV and K. pneumoniae co-infection was significantly higher than those in the other groups. Bacterial loads in the tissues in H9N2 IAV and K. pneumoniae co-infection group were significantly higher than those in the single K. pneumoniae infection group at 7 dpi. It demonstrated that prior H9N2 IAV infection contributed to K. pneumonia proliferation and delayed bacterial clearance in mice. Secondary K. pneumoniae infection influences seroconversion of anti-H9N2 antibody titers and the cytokine profiles. The findings demonstrated that H9N2 IAV infection facilitated secondary K. pneumonia infection, causing severe the diseases in mice.

The hybrid method (HM) presented in this article assembles the high-resolution finite volume method (HRFVM) and the standard method of moments (SMOM) with an accurate inversion technique for determining the crystal size distribution (CSD), providing a computationally efficient solution with reliable accuracy for one-dimensional population balance modeling in batch thermocycling crystallizations. Two chemical systems, paracetamol and L-ascorbic acid, are chosen to study the accuracy and computational efficiency of the approach in the unseeded and seeded cases, respectively. Comparisons between the HRFVM and the HM are made for different temperature profiles in both cases. In addition, the compiled C/Mex files (MXFs) are implemented to further minimize the run time of the HM, and the benefits of the compiled files are discussed compared to the MATLAB files (MAFs).

The aeroelastic modeling of Tjaereborg wind turbine blades was performed based on the unsteady Reynolds Averaged Navier-Stokes equations (URANS) combined with Finite Element Method (FEM) in a loosely coupled manner. This method was verified by comparing numerical and experiment results at four axial inflow wind speeds. Furthermore, the aeroelastic performance of Tjaereborg wind turbine under yaw angle of 10°, 30° and 60°were computed and analyzed. The results showed that the average power and thrust of the wind turbine decreased with increasing yaw angle, along with the increasing oscillation amplitude under large yaw angle. The aerodynamic load showed periodic change within one revolution of rotor, resulting in the blade deflection and the strain present considerably asymmetric distributions. The maximum deflection and strain occurred at azimuth angle of about90° and their minimum values occurred at azimuth angle of about 270°. Besides, both the maximum deflection and strain under yaw conditions became larger than those in axial inflow condition do. For Tjaereborg wind turbine, the coupled solver gave a higher average power and thrust than the CFD solver alone. The aerodynamic performances showed more asymmetrical characters under the combined effect of yaw and fluid structure interaction (FSI).

The effect of seed loading and batch trajectory on the growth of crystals with two size coordinates is studied using a simple model for two crystallization systems known to exhibit shape evolution: hen egg white lysozyme and hydroquinone. For moderate seed loading, batch trajectories that lead to a high supersaturation near the beginning of the batch result in a larger nucleated mass and less growth of the seed crystals than other alternatives, while trajectories that keep the supersaturation almost constant give good performance. Increasing seed mass and decreasing seed size also improves performance. Critical seed loading analysis shows that the two-dimensional systems considered in this work behave similarly to one-dimensional crystallization systems considered previously.

The Nd7.69Fe92.31-xTix (x = 0, 4, 8, 12) alloy were prepared by arc smelting and high energy ball milling method. The morphology and phase structure of the powders were analyzed by Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and the effect of the Ti content on microwave absorbing properties of the powders were measured by a vector network analyzer (VNA). The results reveal that the samples mainly consisted of Nd2Fe17 and α-Fe crystal structure. The minimum absorption peak frequency shifts to lower frequency region firstly and then shifts to higher frequency region with the increasing amount of Ti content. The minimum reflection loss of Nd7.69Fe84.31Ti8 powder is-31.35 dB and the bandwidth of R < -5 dB reach 3.6 GHz when the coating thickness is 2.0 mm. With the increasing of the coating thickness, the minimum reflectivity peak value of the Nd7.69Fe84.31Ti8 moves to lower frequency region and the minimum reflection loss increase firstly and then decrease. And the minimum reflection value of Nd7.69Fe84.31Ti8 alloy can reach to-38.74 dB (microwave absorption rate 99.99%) at 5.68 GHz, and the bandwidth of R < -10 dB reach 1.12 GHz with the best matching thickness of 2.2 mm.

The wake of a wind turbine has substantial influence on the aerodynamic performance of downstream wind turbine. Unsteady numerical simulations are performed in this paper to investigate the wake structure of a three-bladed H-type VAWT (vertical axis wind turbine) and the influence on the aerodynamic performance of downstream wind turbine. A simplified two-dimensional model is used considering the blades are straight. Unsteady Reynolds Averaged Navier–Stokes equations are solved using FlowVision software, which uses dynamic grid method to handle the blade rotation. The SST turbulence model is used for turbulence modeling. The distance between two wind turbines is from 5D to 17D with 2D intervals, where D denotes the wind turbine diameter. The wind speed is 5.07 m/s, corresponding to a tip speed ratio of 2.15. The power coefficients of two wind turbines are compared in detail. The discussions focus on the periodic variations of the aerodynamic performance and flow variables of two turbines with two typical distances, i.e., 7D and 15D, respectively. The simulation results show that the velocity recovery distance needed for a VAWT is usually larger than 15D.

MnAlFe alloy was prepared by the combined use of smelting, high-energy ball milling and tempering heat treatment process. The phase composition and microwave absorbing properties of MnAlFe alloy were investigated by X-ray diffractometer(XRD) and vector network analyzer. The results show that the powders consist of Al8Mn5 single phase with different Fe content; the dielectric loss and the magnetic loss increases with the addition of Fe, the resonant frequency and absorption peak of ε″ and μ″ moves towardslower frequency region simultaneously. The (Al8Mn5)99Fe exhibits preferably comprehensive microwave absorbing properties in the range of 6-18 GHz. The value of the minimum reflectivity and absorption peak frequency with the coating thickness of 1.5 mm, are -23.1 dB, 15.04 GHz respectively. Owing to the wide applications of electromagnetic waves in the range of 1–4 GHz for mobile phone, local area network, radar systems and so on over the past few decades, the serious problems of the electromagnetic interference and electromagnetic compatibility have become increasingly prominent in recent years. Microwave absorbing materials, which possess special performance for absorbing electromagnetic wave, have been applied in both civil and military fields and play an important role in camouflage technology. In military field, stealth technology to reduce and eliminate the electromagnetic radiation and electromagnetic interference resulting from the broad applications of various kinds of electronic and microwave instruments, stealth technology plays an important strategic role in the wars in future[1-2]. The microwave absorbing materials can be used to reduce radar cross section for military use. For this reason, the microwave absorbing material is vitally important for both civil and military fields[3-7]. In view of this utilization, excellent microwave absorbing materials should exhibit strong microwave absorption properties over a wide frequency range and need to be thin and light in weight. It has an important meaning to the application of magnetic microwave absorbing materials. MnAl alloy can be used as microwave absorbent. It has properties such as light in weight, good thermal stability and corrosion resistance[8-11]. But as permanent magnets, MnAl has shortcomings such as their difficulties of fabrication and high costs that prevent them from being used as permanent magnets. A great value would be brought to either theory or practice through proper treatments as further improvement in properties. In this paper, we will discuss the effects of changing relative content of Fe on absorption properties of Al8Mn5 alloy.

This paper mainly focuses on the modeling and simulation of the doubly fed induction generator (DFIG) based wind turbine generation system. In this paper, a new method which combines the mechanical part and electrical part is presented to model the wind turbine generation system. The turbine rotor blade is modeled by the lifting line model and the aerodynamic forces are solved by the improved free vortex wakes method with the supplementary of two dimensional aerodynamic data (three dimensional corrected). The control system of pitching and generator with voltage oriented control (VOC) are established in Matlab/Simulink. The drive train is also modeled with two mass model. In order to realize the coupling computation of the wind turbine model, a data link is built to transfer the parameters between aerodynamic part and electrical part. In this way, the interaction between turbine rotor and generator could be predicted. The validations are firstly made to ensure the reliability of the model. Then the performance of a 1.5 MW wind turbine is investigated with this integrated model under different wind and symmetrical grid voltage dip condition.

In this paper, non-deterministic CFD (computational fluid dynamics) simulations have been performed to investigate the uncertain effects of stochastic boundary conditions on the aerodynamic performance of wind turbines. A NIPRC (non-intrusive probabilistic collocation) method is employed, which is coupled with a commercial flow solver. A 2D (two-dimensional) airfoil case is used to validate the non-deterministic simulation, where the angle of attack is considered as an uncertain parameter in a Gaussian distribution. The simulation results are compared with Monte Carlo simulation results. Based on the validation, non-deterministic CFD simulations were performed on a 3D (three-dimensional) wind turbine blades case, where the wind speed is considered as an uncertain parameter. The discussions mainly focus on the total performance variations and the uncertainty propagation in the fluid field. The simulation results show that the input uncertainty of the inlet velocity results in a high variation zone in the pressure distribution near the blade root, and which decreases from the root to the tip. With the wind speed increases, flow separation is observed. The separation vortex regions correspond to the maximum variation area, and the maximum variation extends to the trailing edge even to the whole suction side.

The aerodynamic performance and the bypass flow field of a vertical axis wind turbine under self-starting are investigated using CFD simulations in this paper. The influence of pitch angle variations on the performance of the wind turbine during self-starting is presented. A two-dimensional model of the wind turbine with three blades is employed. A commercial software FlowVision is employed in this paper, which uses dynamic Cartesian grid. The SST turbulence model is used for turbulence modeling, which assumes the flow full turbulent. Based on the comparison between the computed time-dependent variations of the rotation speed with the experimental data, the time-dependent variations of the torque are presented. The characteristics of self-starting of the wind turbine are analyzed with the pitch angle of 0o、-2oand 2o. The influence of pitch angle variations on two-dimensional unsteady viscous flow field through velocity contours is discussed in detail.

The present study focuses on the experimental and numerical investigation of heat transfer performance downstream of the cooling holes on a flat plate with zero streamwise pressure gradient. The experiment was conducted in a low speed wind tunnel. The holes are circular in either straight or curved shape with an angle of 90°. In the experiments, both local and transverse averaged cooling effectiveness and heat transfer coefficient in the surface are studied for single and multiple holes in a row over a range of blowing ratio from 0.5 to 1.22 for single hole and 0.32–1.18 for multiple holes. Surface temperatures downstream of the injection were measured by means of thermal liquid crystals (TLC) and its associated camera system. Numerical simulation were perform for single hole at blowing ratios 0.51 and 1.04 by using Detached Eddy Simulation (DES) method based on S–A one equation turbulence model. In comparison with the straight hole, the curved one shows better overall performance expressed by net heat flux reduction (NHFR) based on both the experimental and numerical results, such as a better transverse spreading, higher cooling effectiveness and an increased local heat transfer coefficient are concluded for the curved hole.

In order to assess the influences of curved hole passage on cooling effectiveness and flow structure of turbine blade leading edge, the detached eddy simulation is applied to numerically investigate the AGTB turbine cascade under the condition of global blowing ratio M=0.7. The straight or curved cooling holes are located at either the pressure or suction side near the leading edge. The analysis and discussion focus on the local turbulence structure; influence of pressure gradient on the structure, and distribution of cooling effectiveness on the blade surface. The numerical results show that cooling hole with curved passage could bring positive impact on the increase of the local cooling effectiveness. On the suction side, the increased cooling effectiveness could be about 82% and about 77% on the pressure side, compared to the conventional straight hole.

Remotely sensed data have become a valuable source of data for mapping regional or global land cover. Referable to the spectral complexity and the quality of remotely sensed data selected, classification errors usually occurred in land cover mapping, where the errors occurred can result in an issue in which the spatial heterogeneity in remotely sensed data is inconsistent with that in land cover data. To ensure data quality, land cover data checking mainly depends on manual labor, which is time-consuming and labor-intensive. To tackle this issue, a spatial heterogeneity-based Voronoi matching method for automated detection of land cover data inconsistency is proposed. First, Harris corner-based Voronoi diagrams (HCVDs) are constructed utilizing the image noise filter and Harris corner detector. Second, the regional statistics of range on land cover data using HCVDs is calculated. Ultimately, by matching the heterogeneity in HCVDs and using HCVDs-based first-order neighbor filter, where inconsistent spatial heterogeneity occurs in land cover data can be found. A GlobeLand30 case study from Linqu County, Shandong, for the year 2010 in China is carried out. After detection and validation, this method is shown to be workable for detecting spatial regions where inconsistent spatial heterogeneity occurs in land cover data, and the data quality is improved by 6.3% in this study area after manual verification.

In present paper, the mathematic background of intrusive polynomial chaos (IPC) method and coupling process with one dimension Euler equation were introduced. The IPC method was implemented for the 2D compressible stochastic Navier-Stokes equations to simulate the non-deterministic behavior of a lid driven cavity flow under the influence of uncertainties. The driven velocity and fluid viscosity were supposed respectively to be the uncertain variable which has Gaussian probability distribution. Based on the validation with benchmark results, discussions were mainly focused on the statistic properties of velocity distribution. The results indicated the effect of IPC method on the simulation of propagation of uncertainty in the flow field. For the simulated results of 2D cavity flow, influence of the driven velocity uncertainty is larger than that of viscosity.