摘要：A large dual-polarization microstrip reflectarray with China-coverage patterns in two operating bands is *** sufficiently compensate for the spatial phase delay differences in two operating bands separately,a three-layer rectangular patch element is addressed,which is suitable for the large dual-polarization *** to the complexly shaped areas and high gain requirements,there are more than 25000 elements in the reflectarray,making it difficult to design,due to more than 150000 optimization ***,the discrete fast Fourier transform(DFFT)and the inverse DFFT are used to establish a one-to-one relationship between the aperture distribution and the far field,which lays a foundation for optimizing the shaped-beam *** intersection approach,based on the alternating projection,is used to obtain the desired reflection phases of all the elements at some sample frequencies,and a new method for producing a suitable initial solution is proposed to avoid undesired local *** validate the design method,a dual-polarization shaped-beam reflectarray with 7569 elements is fabricated and *** measurement results are in reasonable agreement with the simulation ***,for the large broadband reflectarray with the minimum differential spatial phase delays in the operating band,an approach for determining the optimal position of the feed is *** simultaneously find optimal dimensions of each element in two orthogonal directions,we establish a new optimization model,which is solved by the regular polyhedron ***,a dual-band dual-polarization microstrip reflectarray with 25305 elements is designed to cover the continent of *** results show that patterns of the reflectarray meet the China-coverage requirements in two operating bands,and that the proposed optimization method for designing large reflectarrays with complexly shaped patterns is reliable and efficient.

摘要：A high-contrast coronagraph for direct imaging of an Earth-like exoplanet at the visible band needs a contrast of 10^-10 at a small angular separation of 4λ/D or less. Here we report our recent laboratory experiment that approaches these lim- its. Our test of a high-contrast imaging coronagraph is based on our step-transmission apodized filter. To achieve this goal, we use a liquid crystal array as a phase correc- tor to create a dark hole based on our dedicated algorithm. We have suppressed the diffraction and speckle noise near the point image of a star to a level of 1.68 × 10^-9 at 4λ/D, which can be used for direct imaging of Jupiter-like exoplanets. This demon- strates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.

摘要：Two-dimensional(2D)carbon nitride(CN)photocatalysts are attracting extensive attention owing to their excellent photocatalytic *** this study,we successfully prepared CN materials with heterogeneous structures via hydrothermal treatment,high-temperature roasting,ball milling,sintering,and other *** from interface interactions in hybrid architectures,the CN photocatalysts exhibited high photocatalytic *** rate of hydrogen production using these CN photocatalysts reached 17028.82μmol h^(−1)g^(−1),and the apparent quantum efficiency was 11.2%at 420 *** ns-level time-resolved photoluminescence(PL)spectra provided information about the time-averaged lifetime of fluorescence charge carriers;the lifetime of the charge carriers causing the fluorescence of CN reached 9.99 ***,the CN photocatalysts displayed satisfactory results in overall water splitting without the addition of sacrificial *** average hydrogen and oxygen production rates were 270.95μmol h^(−1)g^(−1)and 115.21μmol h^(−1)g^(−1)in 7 h,respectively,which were promising results for the applications of the catalysts in overall water splitting *** investigated the high efficiency of the prepared CN photocatalysts via a series of tests(UV-vis diffuse reflectance spectroscopy,photocurrent response measurements,PL emission spectroscopy,time-resolved PL spectroscopy,and Brunauer-Emmett-Teller analysis).Furthermore,the Mott-Schottky plot and current-voltage curve were acquired via electrochemical *** fabricated CN photocatalyst had a small p-n junction in its heterogeneous structure,which further enhanced its photocatalytic ***,this work can promote the development of CN photocatalysts.

摘要：医学场景下的数据集通常呈现长尾分布的特点,这种不平衡性可能导致模型偏向头部类,而对尾部类的识别性能较差,从而影响模型的准确性。常见的解决方法是对原始数据进行数据增强,使其具备平衡分布的特点,但增强后的尾部类样本质量往往不佳,没有真正改善尾部类的分类精度。针对此问题,提出一种大选择性核双边网络模型(LSKBB)。该模型主要由传统学习分支和重新再平衡分支两部分组成,采用LSK模块来获取关键信息和关注上下文信息,设计了可以使模型由一个关注方向逐渐过渡到另一个关注方向的动态损失函数,从而提高分类精度。在不改变长尾分布特点的医学数据集中进行图像分类实验,与现有方法相比,所提出的LSKBB模型性能在不平衡率为10,50和100时,在BreaKHis数据集下,准确率分别提高1.41%,1.25%和1.25%;在ChestX-ray数据集下,准确率分别提高6.10%,3.15%和2.47%。实验结果表明,LSKBB模型在不同的不平衡率下性能较好,可用于长尾分布的医学数据集的分类检测。

摘要：实现叉车障碍物识别与定位对提升物流仓储行业自动化、智能化具有重要的意义。现有技术大多受限于实际生产中的复杂场景,无法满足对障碍物识别与定位的高精度实时性的要求。针对现有问题,文中提出了一种基于深度学习的智能叉车障碍物识别与定位方法,以实现在仓储货场环境下对障碍物实时、高精度的识别与定位。首先,设计了改进的YOLOX-nano网络获取障碍物外接矩形框,实现对障碍物的检测与提取;然后设计了基于改进的DeepLabv3+网络对筛选出的障碍物进行分割;最后采用阈值化分割方法对障碍物分割区域进行轮廓提取,进而求解障碍物的像素中心点。在叉车实际工作环境中的障碍物数据集上进行实验,结果表明,该方法能够快速准确地对障碍物物中心进行定位。其中第1阶段的障碍物检测平均精度均值为99.90%,平均检测时间为25.62 ms;第2阶段障碍物分割的平均像素准确度为95.93%,平均分割时间为24.69 ms,保证叉车对障碍物实时识别的同时具有较高的准确率。

摘要：A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.

摘要：A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high selectivity toward F^- over Cl^-, Br^-, I^-, AcO^-, H2PO4^-.

摘要：On the basis of the FLP (frustrated Lewis pair) principle, a new strategy has been proposed to construct the "frustration" in de- signing metal-free hydrogen activation compounds, by using FMO (frontier molecular orbital) analyses and quantum mechanics calculations. Unlike the known FLPs which use bulky substituents to prevent them from forming stable Lewis acid/base com- plexes, the new approach encumbers the intramolecular π donation from the electron donor to the acceptor (e.g. in BH2NH2) by using a CH2 bridge (giving BH2CH2NH2). The strategy is simple and effective. Its effectiveness is demonstrated by the small hy- drogen activation energy (12.0 kcal/mol) of the model molecule (BH2CH2NH2), which is significantly less than the 42.7 kcal/mol of BH2NH2 and also less than the 18.5 kcal/mol of BH2PH2 whose derivative, R2PB(C6F5)2, has been experimentally shown to be able to activate hydrogen. We also exemplified how to use the strategy to design experimentally more realizable molecules. The example shows promises as a hydrogen activation agent. The strategy can be used to design metal-free catalysts for direct hydro-genation.

摘要：As a new software paradigm evolved by the Internet, Internetware brings many challenges for the traditional software development methods and techniques. Though architecture-based component composition （ABC） approach is originated in the traditional software paradigm, it supports the engineering of Internetware effectively due to its philosophy, rationales and mechanisms. ABC has three major contributions to the en- gineering of Internetware in detail. First, the feature oriented domain modeling method can structure the ＂disordered＂ ＂software entities＂ to ＂ordered Internetware＂ bottom-up in the problem space. Second, the architecture centric design and analysis method can support the development of self-adaptive Internetware. Third, the component operating platform is a reflective and self-adaptive middleware that not only provides Internetware with a powerful and flexible runtime infrastructure but also enables the self-adaptation of the structure and individual entities of Internetware.

摘要：基于电路交换、软交换及IMS技术的电力交换网标准体系已经初步形成,但电力行政交换网的云化发展以及调度交换网的IP化改造使得原有的标准体系不能充分支撑未来网络建设和演进。文章首先分析了现有标准体系架构,然后结合技术发展分析了各现行标准存在的问题,针对网络建设需求,提出了需要修订和增编的技术规范,最后构建了电力标准体系规划布局。