摘要：A validated numerical model was established to simulate gas−liquid flow behaviors in the oxygen-enriched side-blown bath *** model included the slip velocity between phases and the gas thermal expansion *** modeling results were verified with theoretical correlations and experiments,and the nozzle-eroded states in practice were also involved in the *** comparison,it is confirmed that the thermal expansion effect influences the flow pattern significantly,which may lead to the backward motion of airflow and create a potential risk to production ***,the influences of air injection velocity and furnace width on airflow behavior were investigated to provide operating and design *** is found that the thin layer melt,which avoids high-rate oxygen airflow eroding nozzles,shrinks as the injection velocity increases,but safety can be guaranteed when the velocity ranges from 175 to 275 m/***,the isoline patterns and heights of thin layers change slightly when the furnace width increases from 2.2 to 2.8 m,indicating that the furnace width shows a limited influence on production safety.

摘要：Instance segmentation plays an important role in image *** Deep Snake algorithm based on contour iteration deforms an initial bounding box to an instance contour end-to-end,which can improve the performance of instance segmentation,but has defects such as slow segmentation speed and sub-optimal initial *** solve these problems,a real-time instance segmentation algorithm based on contour learning was ***,ShuffleNet V2 was used as backbone network,and the receptive field of the model was expanded by using a 5×5 convolution ***,a lightweight up-sampling module,multi-stage aggregation(MSA),performs residual fusion of multi-layer features,which not only improves segmentation speed,but also extracts effective features more ***,a contour initialization method for network learning was designed,and a global contour feature aggregation mechanism was used to return a coarse contour,which solves the problem of excessive error between manually initialized contour and real ***,the Snake deformation module was used to iteratively optimize the coarse contour to obtain the final instance *** experimental results showed that the proposed method improved the instance segmentation accuracy on semantic boundaries dataset(SBD),Cityscapes and Kins datasets,and the average precision reached 55.8 on the SBD;Compared with Deep Snake,the model parameters were reduced by 87.2%,calculation amount was reduced by 78.3%,and segmentation speed reached 39.8 frame·s−1 when instance segmentation was performed on an image with a size of 512×512 pixels on a 2080Ti *** proposed method can reduce resource consumption,realize instance segmentation tasks quickly and accurately,and therefore is more suitable for embedded platforms with limited resources.

摘要：化学取代是有效调节分子电导,产生多通道输运、量子干涉效应和其他机制的关键方法.但分子骨架和侧基之间存在复杂的相互作用,目前仍未被研究清楚.在本工作中,我们结合扫描隧道显微镜裂结实验技术和第一性原理计算方法,深入研究了具有不同σ和π侧基的分子电导.实验结果及理论分析表明,σ侧基的加入引起了分子前线轨道的对称性破缺并加剧了分子内散射,从而导致电导的降低.相反,π侧基引入了额外的电荷传输通道,实现了电荷传输的多通道效应,增加了分子的电导.这些发现为未来分子功能化和分子电子器件的设计提供了坚实的基础.

摘要：computational thermodynamics,known as CALPHAD method when dawned in 1950s,aimed at coupling phase diagrams with thermochemistry by computational *** eventually evolves toward kinetic simulations integrated with thermodynamic calculations,i.e.,computational kinetics,including diffusion-controlled phase transformation,precipitation simulation,and phasefield *** the meantime,thermodynamic,mobility,and physical property databases for multi-component and multi-phase materials,served as basic knowledge for materials design,are critically evaluated by CALPHAD approach combining key experiments,first-principles calculations,statistic methods,and empirical *** combination of these computational techniques with their conjugated databases makes it possible to simulate phase transformations and predict the microstructure evolution in real materials in a foreseeable *** links to microand macro-scale simulations lead to a multi-scale computational framework,and aid the search for the quantitativerelations among chemistry,process,microstructures,and materials properties in order to accelerate materials development and *** is a new route of materials and process design pursued by Integrated computational Materials engineering(ICME)and Materials Genome Initiative(MGI).This article presents a review on the basic theories and applications,the state of the art and perspective of computational thermodynamics and kinetics.

摘要：Peptoids(or poly-N-substituted glycines)are a promising class of bioinspired sequence-defined polymers due to their highly efficient synthesis,high chemical stability,enzyme hydrolysis resistance,and *** tuning the side chain chemistry of peptoids,it allows for precise control over sequences and achieving a large side-chain *** to these unique features,in the last several years,many amphiphilic peptoids were designed as highly tunable building blocks for the preparation of biomimetic nanomaterials with well-defined hierarchical structures and desired ***,we provide an overview of the recent achievements in this area by dividing them into the following three ***,mica-and silica-templated peptoid selfassembly are *** presence of inorganic substrates provides the guarantee of investigating their selfassembly mechanisms and interactions between peptoids and substrates using nanoscale characterization techniques,particularly in situ atomic force microscopy(AFM)and AFMbased dynamic force spectroscopy(AFM-DFS).Second,solution-phase self-assembly of peptoids into nanotubes and nanosheets is presented,as well as their self-repair ***,the applications of peptoid-based nanomaterials are outlined,including the construction of catalytic nanomaterials as a template and cytosolic delivery as cargoes.

摘要：A reasonable design strategy to improve the utilization of noble metal electrocatalysts for the hydrogen evolution reaction(HER)is crucial to simplify the process flow and accelerate the future renewable energy ***,abundant defects were created on 2.4-nm Ru nanoparticles to achieve unprecedently high mass-specific reactivity in harsh acidic and alkaline *** obtained defect-enriched Ru(DR-Ru)exhibits an ultrahigh HER turnover frequency of16.4 s^(-1)with a 100-mV overpotential in alkaline media,and it also retains an excellent value of 20.6 s^(-1)in acidic media;these results are superior to those reported for other Ru ***,a record-low loading of 2.5μg cm^(-2)for the DR-Ru catalysts and low overpotentials of 28.2 and 25.1 mV at10 mA cm^(-2)can be realized in alkaline and acidic media,***,the less coordinated Ru surface sites and partial lattice oxygen introduction weaken the bonding between H and DR-Ru catalysts,facilitate fast acidic HERkinetics and help dissociate the water molecule to overcome the major challenge of HER in alkaline electrolytes,leading to an activity comparable to that under acidic *** result provides a guideline for defect engineering on noble metal nanocatalysts to effectively improve the utilization of the catalysts and optimize reactivities.

摘要：Ocean waves can directly drive WECs （wave energy converters） to perform two types of motion--reciprocating motion and unidirectional rotary motion. In general, the efficiency of a reciprocating WEC is strongly wave-frequency dependent, whereas the efficiency of a rotary WEC can be somewhat wave-frequency independent. To date, a huge majority of WEC technologies under development in industry belong to the reciprocating class, and only a few WEC concepts fall in the unidirectional rotary class. In the present work, a wave-driven rotor for unidirectional rotary motion was proposed and characterized. A numerical tool has been developed for characterization of the rotor＇s unidirectional rotary tendency. The tool included a wave model and a drag force model. Simple circular tubes were used as blades in a basic rotor design. This basic design demonstrated strong potential for unidirectional rotary motion at a proper rotor submersion level and under various wave conditions. Two improved designs were yielded from the basic design. In one improved design, the original circular tubes were replaced with cylindrical shells of semicircular cross section as new blades. In another design, the semicircular shells were further modified to become one-way foldable. The two improvements significantly enhanced the rotors＇ unidirectional rotary tendency in waves, which has been verified by numerical simulation. Broad ranges of wave parameters and the submersion level have been numerically explored on the two improved rotor designs in conjunction with dimensional analysis.

摘要：The K-multiple-means(KMM)retains the simple and efficient advantages of the K-means algorithm by setting multiple subclasses,and improves its effect on non-convex data *** aiming at the problem that it cannot be applied to the Internet on a multi-view data set,a multi-view K-multiple-means(MKMM)clustering method is proposed in this *** new algorithm introduces view weight parameter,reserves the design of setting multiple subclasses,makes the number of clusters as constraint and obtains clusters by solving optimization *** new algorithm is compared with some popular multi-view clustering *** effectiveness of the new algorithm is proved through the analysis of the experimental results.

摘要：A flow control method based on an active jet is developed to restart hypersonic inlets. The dynamic restarting process is numerically reproduced by unsteady Reynolds averaged Navier-Stokes(RANS) modeling to verify the effectiveness and reveal the influence of jet conditions. The active jet improves the inlet unstart status by drawing the high-pressure separation bubble from the internal compression duct and performing a full expansion to alleviate the adverse pressure gradient. Moreover, the favorable pressure gradient in the inlet caused by jet expansion allows for a successful restart after turning off the jet. The influence of the jet momentum ratio is then analyzed to guide the design of the active jet control method and choose the proper momentum ratios. A low jet momentum does not eliminate the high-pressure separation bubble, whereas an excessive jet momentum causes severe momentum loss due to the induced shock. The general rule in restarting the inlet using an active jet is to allow a full jet expansion downstream of the jet slot while avoiding excessive momentum loss upstream and preventing the thick low-speed layer.

摘要：In view of the problems of multi-scale changes of segmentation targets,noise interference,rough segmentation results and slow training process faced by medical image semantic segmentation,a multi-scale residual aggregation U-shaped attention network structure of MAAUNet(MultiRes aggregation attention UNet)is proposed based on ***,aggregate connection is introduced from the original feature aggregation at the same *** connection is redesigned to aggregate features of different semantic scales at the decoder subnet,and the problem of semantic gaps is further solved that may exist between skip ***,after the multi-scale convolution module,a convolution block attention module is added to focus and integrate features in the two attention directions of channel and space to adaptively optimize the intermediate feature ***,the original convolution block is *** convolution channels are expanded with a series convolution structure to complement each other and extract richer spatial *** connections are retained and the convolution block is turned into a multi-channel convolution *** model is made to extract multi-scale spatial *** experimental results show that MAAUNet has strong competitiveness in challenging datasets,and shows good segmentation performance and stability in dealing with multi-scale input and noise interference.