Sunspot Group Detection and Classification by Dual Stream Convolutional Neural Network Method

The automatic detection and analysis of sunspots play a crucial role in understanding solar dynamics and predicting space weather events.This paper proposes a novel method for sunspot group detection and classification called the dual stream Convolutional Neural Network with Attention Mechanism(DSCNN-AM).The network consists of two parallel streams each processing different input data allowing for joint processing of spatial and temporal information while classifying sunspots.It takes in the white light images as well as the corresponding magnetic images that reveal both the optical and magnetic features of sunspots.The extracted features are then fused and processed by fully connected layers to perform detection and classification.The attention mechanism is further integrated to address the“edge dimming”problem which improves the model’s ability to handle sunspots near the edge of the solar disk.The network is trained and tested on the SOLAR-STORM1 data set.The results demonstrate that the DSCNN-AM achieves superior performance compared to existing methods,with a total accuracy exceeding 90%.

Reheat effect on the improvement in efficiency of the turbine driven by pulse detonation

Due to the strong unsteadiness of pulse detonation,large flow losses are generated when the detonation wave interacts with the turbine blades,resulting in low turbine efficiency.Considering that the flow losses are dissipated into the gas as heat energy,some of them can be recycled during the expansion process in subsequent stages by the reheat effect,which should be helpful to improve the detonationdriven turbine efficiency.Taking this into account,this paper developed a numerical model of the detonation chamber coupled with a two-stage axial turbine,and a stoichiometric hydrogen-air mixture was used.The improvement in turbine efficiency attributable to the reheat effect was calculated by comparing the average efficiency of the stages with the efficiency of the two-stage turbine.The research indicated that the first stage was critical in suppressing the flow unsteadiness caused by pulse detonation,which stabilized the intake condition of the second stage and consequently allowed much of the flow losses from the first stage to be recycled,so that the efficiency of the two-stage turbine was improved.At a 95%confidence level,the efficiency improvement was stable at 4.5%—5.3%,demonstrating that the reheat effect is significant in improving the efficiency of the detonation-driven turbine.

Genome-Wide Identification and Expression Profiling of the Shaker K+ Channel and HAK/KUP/KT Transporter Gene Families in Grape (Vitis vinifera L.)

Potassium(K+)is an essential macronutrient for plants to maintain normal growth and development.Shaker-like K+channels and HAK/KUP/KT transporters are critical components in the K+acquisition and translocation.In this study,we identified 9 Shaker-like K+channel(VvK)and 18 HAK/KUP/KT transporter(VvKUP)genes in grape,which were renamed according to their distributions in the genome and relative linear orders among the distinct chromosomes.Similar structure organizations were found within each group according to the exon/intron structure and protein motif analysis.Chromosomal distribution analysis showed that 9 VvK genes and 18 VvKUP genes were unevenly distributed on 7 or 10 putative grape chromosomes.Three pairs of tandem duplicated genes and one pair of segmental duplicated genes were observed in the expansion of the grape VvKUP genes.Gene expression omnibus(GEO)data analysis showed that VvK and VvKUP genes were expressed differentially in distinct tissues.Various cis-acting regulatory elements pertinent to phytohormone responses and abiotic stresses,including K+deficiency response and drought stress,were detected in the promoter region of VvK and VvKUP genes.This study provides valuable information for further functional studies of VvK and VvKUP genes,and lays a foundation to explore K+uptake and utilization in fruit trees.

Photoperiod and Nitrogen Supply Limit the Scope of Northward Migration and Seed Transfer of Black Spruce in a Future Climate Associated with Doubled Atmospheric CO2 Concentration

The predicated changes in precipitation and temperature associated with the continued elevation of atmospheric CO2 concentration will trigger the northward shift of the Climate Envelopes for 130 North America tree species by as much as 10 degrees. However, climate envelope models do not take into account changes in other factors that may also influence the survival and growth of plants at the predicted new locations, such as photoperiod and nutrient regimes. This study investigated how photoperiod and nitrogen supply would affect the ecophysiological traits of black spruce (Picea mariana (Mill) B. S. P.) that are critical for survival and growth at new locations predicted by climate envelope models. We exposed black spruce seedlings to the photoperiod regime at the seed origin (PS) and that 10° north of the seed origin (PNM) as predicted by climate envelope models under the current and doubled atmospheric CO2 concentration and different levels of N supply (30 vs. 300 μmol·mol-1 N). We found that the PNM and the 30 μmol·mol-1 N supply both had negative impact on the development of seedling cold hardiness in the fall, and led to earlier burst of the terminal bud and greater rate of mortality in the following growing season. While the PNM stimulated seedling growth in the first growing season, the effect was not sustained in the second growing season. Our results suggest that the photoperiod regimes and poor nutrient conditions at higher latitudes will likely constrain the scope of the northward migration or seed transfer of black spruce.

N/P/K Ratios and CO₂Concentration Change Nitrogen-Photosynthesis Relationships in Black Spruce

The relationship between photosynthesis and leaf nitrogen concentration is often used to model forest carbon fixation and ratios of different nutrient elements can modify this relationship. However, the effects of nutrient ratios on this important relationship are generally not well understood. To investigate whether N/P/K ratios and CO2 concentration ([CO2]) influence relationships between photosynthesis and nitrogen, we exposed one-year-old black spruce seedlings to two [CO2] (370 and 720 μmol·mol-1), two N/P/K ratio regimes (constant (CNR) and variable (VNR) nutrient ratio) at 6 N supply levels (10 to 360 μmol·mol-1). It was found that photosynthesis (Pn) was more sensitive to nitrogen supply and N/P/K ratios under the elevated [CO2] than under ambient [CO2];under the elevated [CO2], Pn declined with increases in N supplies above 150 μmol·mol-1 in the CNR treatment but was relatively insensitive to N supplies of the same range in the VNR treatment. Further, our data suggest that the nutrient ratio and the CO2 elevation effects on photosynthesis were via their effects on the maximum rate of carboxylation (Vcmax) but not electron transport (Jmax) or triose phosphate utilization (TPU). The results suggest that the CO2 elevation increased the demand for all three nutrient elements but the increase was greater for N than for P and K. The CO2 elevation resulted in greater photosynthetic use efficiencies of N, P and K, but the increases varied with the nutrient ratio treatments. The results suggest that under elevated [CO2], higher net photosynthetic rates demand different optimal N-P-K ratios than under the current [CO2].

Analysis of displacement damage effects on bipolar transistors irradiated by spallation neutrons

Displacement damage induced by neutron irradiation in China Spallation Neutron Source(CSNS) is studied on bipolar transistors with lateral PNP, substrate PNP, and vertical NPN configurations, respectively. Comparison of the effects on different type transistors is conducted based on displacement damage factor, and the differences are analyzed through minority carrier lifetime calculation and structure analysis. The influence of CSNS neutrons irradiation on the lateral PNP transistors is analyzed by the gate-controlled method, including the oxide charge accumulation, surface recombine velocity,and minority carrier lifetime. The results indicate that the total ionizing dose in CSNS neutron radiation environment is negligible in this study. The displacement damage factors based on 1-MeV equivalent neutron flux of different transistors are consistent between Xi’an pulse reactor(XAPR) and CSNS.

Analysis on non-oscillatory singularity behaviors of mode Ⅱ interface crack tip in orthotropic bimaterial

The fracture behaviors near the mode II interface crack tip for orthotropic bimaterial are studied. The non-oscillatory field, where the stress singularity exponent is a real number, is discussed by the complex function method and the undetermined coefficient method. From the research fracture problems, the stress functions with ten undetermined coefficients and an unknown singularity exponent are introduced when △1 〉 0 and △2 〉 0. By the existence theorem of non-trival solutions for the system of eight homogeneous linear equations, the characteristic equation, the stress singularity exponent, and the discriminating condition of the non-oscillatory singularity are found. By the uniqueness theorem of the solutions for the system of twelve non-homogeneous linear equations with ten unknowns, the ten undermined coefficients in the stress functions are uniquely determined. The definitions of the stress intensity factors are given with the help of one-sided limit, and their theoretical formulae are deduced. The analytic solutions of the stresses near the mode II interface crack tip are derived. The classical results for orthotropic material are obtained.

Delta.EPI:a probabilistic voting-based enhancer-promoter interaction prediction platform

Enhancer promoter interaction(EPI)involves most of gene transcriptional regulation in the high eukaryotes.Predicting the EPIs from given genomic loci or DNA sequences is not a trivial task.The benchmarking work so far for EPI predictors is more or less empirical and lacks quantitative model-based comparisons,posing challenges for molecular biologists to obtain reliable EPI predictions.Here,we present an EPI prediction platform,namely Delta.EPI.Based on a statistic model of the data integration,Delta.EPI is capable of comprehensively assessing the predictions from four state-of-the-art EPI predictors.Equipped with a userfriendly interface and visualization platform,Delta.EPI presents the sorted results with the confidence of EPI relevance,which may guide the molecular biologists who lack the pre-knowledge of the algorithms of EPI prediction.Last,we showcase the utility of Delta.EPI with a case study.Delta.EPI provides a powerful tool to fuel the gene regulation and 3D genome studies by ease-to-access EPI predictions.Delta.EPI can be freely accessed at https://ngdc.cncb.ac.cn/deltaEPI/.

Numerical simulation and experimental research on the wheel brush sampling process of an asteroid sampler

To examine the environmental characteristics of the microgravity force and the weathered layer on an asteroid surface,a symmetric wheel brush asteroid sampler is proposed for the collection of particles on the asteroid surface.To study the influence of the wheel brush rotation speed on the sampling efficiency and the driving torque required for the wheel brush,the contact dynamics model between particles and sampling wheel brushes is established and a simulation and experimental verification of the sampling process are conducted.The parameter calibration of the sampled particles is studied first,and the calibrated particle parameters are used in the numerical simulation of the sampling process.The sampling results and the particle stream curves are obtained for the working conditions of different rotation speeds,and the effects of different parameter settings on the sampling efficiency are analyzed.In addition,a set of rotating symmetrical sampling wheel brush devices is built for the ground test,and the dynamic torque sensor is used to test the torque change of the wheel brush during the sampling process.The relationship between the speed of the wheel brush and the driving torque of the wheel brush motor is determined by comparing the simulation results with the test results.Results indicate that when the rotating speed of the wheel brush is faster,the sampling efficiency is higher,and the driving torque required for the sampling wheel brush is greater.Moreover,a numerical simulation analysis of the sampling process of the wheel brush sampler in a microgravity environment is conducted to determine the optimal speed condition,and the brushing test of the wheel brush sampler in the microgravity environment is verified with the drop tower method.This research proposes the structural optimization design and motor selection of a wheel brush asteroid sampler,which provides important reference value and engineering significance.

Data-driven surrogate model for aerodynamic design using separable shape tensor method

In the context of increasing dimensionality of design variables and the complexity of con-straints,the effcacy of Surrogate-Based Optimization(SBO)is limited.The traditional linear and nonlinear dimensionality reduction algorithms are mainly to decompose the mathematical matrix composed of design variables or objective functions in various forms,the smoothness of the design space cannot be guaranteed in the process,and additional constraint functions need to be added in the optimization,which increases the calculation cost.This study presents a new parameterization method to improve both problems of SBO.The new parameterization is addressed by decoupling affine transformations(dilation,rotation,shearing,and translation)within the Grassmannian sub-manifold,which enables a separate representation of the physical information of the airfoil in a high-dimensional space.Building upon this,Principal Geodesic Analysis(PGA)is employed to achieve geometric control,compress the design space,reduce the number of design variables,reduce the dimensions of design variables and enhance predictive performance during the surrogate optimiza-tion process.For comparison,a dimensionality reduction space is defined using 95%of the energy,and RAE 2822 for transonic conditions are used as demonstrations.This method significantly enhances the optimization efficiency of the surrogate model while effectively enabling geometric con-straints.In three-dimensional problems,it enables simultaneous design of planar shapes for various components of the aircraft and high-order perturbation deformations.Optimization was applied to the ONERA M6 wing,achieving a lift-drag ratio of 18.09,representing a 27.25%improvement com-pared to the baseline configuration.In comparison to conventional surrogate model optimization methods,which only achieved a 17.97%improvement,this approach demonstrates its superiority.

Stimuli-responsive nano vehicle enhances cancer immunotherapy by coordinating mitochondria-targeted immunogenic cell death and PD-L1 blockade

Induction of immunogenic cell death promotes antitumor immunity against cancer. However, majority of clinically-approved drugs are unable to elicit sufficient ICD. Here, our study revealed that mitochondria-targeted delivery of doxorubicin(DOX) massively amplified ICD via substantial generation of reactive oxygen species(ROS) after mitochondrial damage. The underlying mechanism behind increased ICD was further demonstrated to be ascribed to two pathways:(1) ROS elevated endoplasmic reticulum(ER) stress, leading to surface exposure of calreticulin;(2) ROS promoted release of various mitochondriaassociated damage molecules including mitochondrial transcription factor A. Nevertheless, adaptive upregulation of PD-L1 was found after such ICD-inducing treatment. To overcome such immunosuppressive feedback,we developed a tumor stimuli-responsive nano vehicle to simultaneously exert mitochondrial targeted ICD induction and PD-L1 blockade. The nano vehicle was self-assembled from ICD-inducing copolymer and PD-L1 blocking copolymer, and possessed long-circulating property which contributed to better tumor accumulation and mitochondrial targeting. As a result, the nano vehicle remarkably activated antitumor immune responses and exhibited robust antitumor efficacy in both immunogenic and non-immunogenic tumor mouse models.

Atomically dispersed dual Fe centers on nitrogen-doped bamboo-like carbon nanotubes for efficient oxygen reduction

Interfacial atomic configuration between dual-metal active species and nitrogen-carbon substrates is of great importance for improving the intrinsic activity of catalysts toward oxygen reduction reaction(ORR).Thus,from the atomic-scale engineering we develop a high intrinsic activity ORR catalyst in terms of incorporating atomically dispersed dual Fe centers(single Fe atoms and ultra-small Fe atomic clusters)into bamboo-like N-doped carbon nanotubes.Benefiting from atomically dispersed dual-Fe centers on the atomic interface of Fe-Nx/carbon nanotubes,the fabricated dual Fe centers catalyst exhibits an extremely high ORR activity(E_(onset)=1.006 V;E_(1/2)=0.90 V),beyond state-of-the-art Pt/C.Remarkably,this catalyst also shows a superior kinetic current density of 19.690 mA·cm^(−2),which is 7 times that of state-of-the-art Pt/C.Additionally,based on the excellent catalyst,the primary Zn-air battery reveals a high power density up to 137 mW·cm^(−2) and sufficient potential cycling stability(at least 25 h).Undoubtedly,given the unique structure–activity relationship of dual-Fe active species and metal-nitrogen-carbon substrates,the catalyst will show great prospects in highly efficient electrochemical energy conversion devices.

Fe(III)-Catalyzed Aerobic Oxidation of 1,4-Diols

Comprehensive Summary Aerobic oxidation has been catching more and more attention because of its atom economy and environmental friendliness.Oxidation of diols is a challenge due to various oxidative products.Thus,highly selective aerobic oxidation affording specific products is of current interest.In this work,a combination of Fe(NO_(3))_(3)·9H_(2)O/TEMPO/KCl catalysis has been identified as an efficient recipe for the aerobic oxidation of 1,4-diols affordingγ-butyrolactones under mild conditions.The reaction exhibits decent chemo-and regioselectivity of symmetrical and unsymmetrical 1,4-diols.The optically activeγ-lactones may also be prepared from optically active 1,4-diols without erosion of the ee via this method.Furthermore,this approach was successfully applied to synthesize NBP,a commercial drug.

A novel sparse feature extraction method based on sparse signal via dual-channel self-adaptive TQWT

Sparse signal is a kind of sparse matrices which can carry fault information and simplify the signal at the same time.This can effectively reduce the cost of signal storage,improve the efficiency of data transmission,and ultimately save the cost of equipment fault diagnosis in the aviation field.At present,the existing sparse decomposition methods generally extract sparse fault characteristics signals based on orthogonal basis atoms,which limits the adaptability of sparse decomposition.In this paper,a self-adaptive atom is extracted by the improved dual-channel tunable Q-factor wavelet transform(TQWT)method to construct a self-adaptive complete dictionary.Finally,the sparse signal is obtained by the orthogonal matching pursuit(OMP)algorithm.The atoms obtained by this method are more flexible,and are no longer constrained to an orthogonal basis to reflect the oscillation characteristics of signals.Therefore,the sparse signal can better extract the fault characteristics.The simulation and experimental results show that the selfadaptive dictionary with the atom extracted from the dual-channel TQWT has a stronger decomposition freedom and signal matching ability than orthogonal basis dictionaries,such as discrete cosine transform(DCT),discrete Hartley transform(DHT)and discrete wavelet transform(DWT).In addition,the sparse signal extracted by the self-adaptive complete dictionary can reflect the time-domain characteristics of the vibration signals,and can more accurately extract the bearing fault feature frequency.

XFEM for Fracture Analysis in 2D Anisotropic Elasticity

In this paper,a method is proposed for extracting fracture parameters in anisotropic thermoelasticity cracking via interaction integral method within the framework of extended finite element method(XFEM).The proposed method is applied to linear thermoelastic crack problems.The numerical results of the stress intensity factors(SIFs)are presented and compared with those reported in related references.The good agreement of the results obtained by the developed method with those obtained by other numerical solutions proves the applicability of the proposed approach and confirms its capability of efficiently extracting thermoelasticity fracture parameters in anisotropic materials.

Derivative ghost imaging

We propose a new experimentally verified ghost imaging(GI) mechanism,derivative GI.Our innovation is that we use the derivatives of the intensities of the test light and the reference light for imaging.Experimental results show that by combining derivative GI with the standard GI algorithm,multiple independent signals can be obtained in one measurement.This combination greatly reduces the number of measurements and the time required for data acquisition and imaging.Derivative GI intrinsically does not produce the storage-consuming background term of GI,so it is suitable for on-chip implementation and makes practical application of GI easier.

Fracture Analysis in Orthotropic Thermoelasticity Using Extended Finite Element Method

In this paper,a method for extracting stress intensity factors(SIFs)in orthotropic thermoelasticity fracture by the extended finite element method(XFEM)and interaction integral method is present.The proposed method is utilized in linear elastic crack problems.The numerical results of the SIFs are presented and compared with those obtained using boundary element method(BEM).The good accordance among these two methods proves the applicability of the proposed approach and conforms its capability of efficiently extracting thermoelasticity fracture parameters in orthotropic material.