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Routing valley exciton emission of a WS_(2) monolayer via delocalized Bloch modes of in-plane inversion-symmetry-broken photonic crystal slabs

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Light(Science & Applications) 2020年第1期9卷 603-610页

作者： Jiajun Wang Han Li Yating Ma Maoxiong Zhao wenzhe liu Bo Wang Shiwei Wu Xiaohan liu Lei Shi Tian Jiang Jian Zi State Key Laboratory of Surface Physics Key Laboratory of Micro-and Nano-Photonics Structures(Ministry of Education)and Department of PhysicsFudan University200433 ShanghaiChina College of Advanced Interdisciplinary Studies National University of Defense Technology410073 ChangshaChina Collaborative Innovation Center of Advanced Microstructures Nanjing University210093 NanjingChina

The valleys of two-dimensional transition metal dichalcogenides(TMDCs)offer a new degree of freedom for information processing.To take advantage of this valley degree of freedom,on the one hand,it is feasible to control valleys by utilizing different external stimuli,such as optical and electric fields.On the other hand,nanostructures are also used to separate the valleys by near-field coupling.However,for both of the above methods,either the required low-temperature environment or low degree of coherence properties limit their further applications.Here,we demonstrate that all-dielectric photonic crystal(PhC)slabs without in-plane inversion symmetry(C_(2) symmetry)can separate and route valley exciton emission of a WS2 monolayer at room temperature.Coupling with circularly polarized photonic Bloch modes of such PhC slabs,valley photons emitted by a WS_(2) monolayer are routed directionally and are efficiently separated in the far field.In addition,far-field emissions are directionally enhanced and have long-distance spatial coherence properties.

关键词： valley symmetry Bloch

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基于特征校正的多对抗域适应方法

电信科学 2024年第1期40卷 71-82页

作者：张永刘昊双章琪刘文哲湖州师范学院信息工程学院浙江湖州313000 辽宁师范大学计算机与信息技术学院辽宁大连116081

领域自适应可以通过对齐源域和目标域的分布将有标签的源域信息迁移到没有标签但相关的目标域。然而,现有的大多数方法仅对源域和目标域的低层特征分布进行对齐,无法捕获样本中的细粒度信息。基于此,提出了一种基于特征校正的多对抗域... 详细信息

领域自适应可以通过对齐源域和目标域的分布将有标签的源域信息迁移到没有标签但相关的目标域。然而,现有的大多数方法仅对源域和目标域的低层特征分布进行对齐,无法捕获样本中的细粒度信息。基于此,提出了一种基于特征校正的多对抗域适应方法。该方法在引入注意力机制以突出可迁移区域的基础上,通过部署特征校正模块对齐两个域之间的高级特征分布,进一步缩小域差异。此外,为了避免单个分类器过度拟合其自身的噪声伪标签,还提出了双分类器协同训练,并利用图神经网络特征聚合的特性生成更精准的源域标签。在3个迁移学习基准数据集上的大量实验证明所提方法的有效性。

关键词：领域自适应迁移学习对抗网络注意力机制

The de novo genome assembly of Tapiscia sinensis and the transcriptomic and developmental bases of androdioecy

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Horticulture Research 2020年第1期7卷 219-234页

作者： Peng Zhao Guiliang Xin Feng Yan Huan Wang Xiaolong Ren Keith Woeste wenzhe liu Key Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationCollege of Life SciencesNorthwest UniversityXi’anShaanxi 710069China USDA Forest Service Hardwood Tree Improvement and Regeneration Center(HTIRC) Department of Forestry and Natural ResourcesPurdue University715 West State StreetWest LafayetteIN 47907USA

Tapiscia sinensis(Tapisciaceae)possesses an unusual androdioecious breeding system that has attracted considerable interest from evolutionary biologists.Key aspects of T.sinensis biology,including its biogeography,genomics,and sexlinked genes,are unknown.Here,we report the first de novo assembly of the genome of T.sinensis.The genome size was 410 Mb,with 22,251 predicted genes.Based on whole-genome resequencing of 55 trees from 10 locations,an analysis of population genetic structure indicated that T.sinensis has fragmented into five lineages,with low intrapopulation genetic diversity and little gene flow among populations.By comparing whole-genome scans of male versus hermaphroditic pools,we identified 303 candidate sex-linked genes,79 of which(25.9%)were located on scaffold 25.A 24-kb region was absent in hermaphroditic individuals,and five genes in that region,TsF-box4,TsF-box10,TsF-box13,TsSUT1,and TsSUT4,showed expression differences between mature male and hermaphroditic flowers.The results of this study shed light on the breeding system evolution and conservation genetics of the Tapisciaceae.

关键词： breeding flowers bases

利用冰冻切片机快速制作木质茎的显微切片技术

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西北植物学报 2024年第7期44卷 1164-1168页

作者：马芳宋玉霞刘文哲西北大学生命科学学院西安710069 宁夏大学民族预科教育学院银川750021 宁夏农林科学院农业生物技术中心银川750002

【目的】植物的木质茎因次生维管组织含量多、细胞壁木质化程度高、质地较硬,所以徒手切片和石蜡切片均难以获得满意的切片效果。冰冻切片机可对一定硬度的组织进行切片,是植物木质茎制片的有效工具之一。【方法】利用冰冻切片机对一些... 详细信息

【目的】植物的木质茎因次生维管组织含量多、细胞壁木质化程度高、质地较硬,所以徒手切片和石蜡切片均难以获得满意的切片效果。冰冻切片机可对一定硬度的组织进行切片,是植物木质茎制片的有效工具之一。【方法】利用冰冻切片机对一些质地均匀、含水量较高的幼小木质茎直接切片;对木质坚硬、含水量较少的茎,经过FAA固定液固定、OCT包埋后(-30)~(-25)℃冰冻切片,再用0.1%甲苯胺蓝染色,显微镜观察并拍照染色效果。【结果】来源于乔木或灌木,直径不超过6 cm的木质茎,利用冰冻切片均可快速获得结构完整、图像清晰、色彩丰富的显微结构图像。【结论】冰冻切片机可用于幼小木质茎的显微切片制作,结合甲苯胺蓝染色,具有简便、高效、易操作的优点。

关键词：木质茎冰冻切片显微结构

Phase characterisation of metalenses

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Light(Science & Applications) 2021年第4期10卷 551-561页

作者： Maoxiong Zhao Mu Ku Chen Ze-Peng Zhuang Yiwen Zhang Ang Chen Qinmiao Chen wenzhe liu Jiajun Wang Ze-Ming Chen Bo Wang Xiaohan liu Haiwei Yin Shumin Xiao Lei Shi Jian-Wen Dong Jian Zi Din Ping Tsai State Key Laboratory of Surface Physics Key Laboratory of Micro-and Nano-Photonic Struaures(Ministry of Education)and Department of PhysicsFudan University200433 ShanghaiChina Department of Electronic and Information Engineering The Hong Kong Polytechnic University999077 Hong KongChina School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen University510275 GuangzhouChina Shanghai Engineering Research Center of Optical Metrology for Nanofabrication(SERCOM) 200433 ShanghaiChina State Key Laboratory on Tunable Laser Technology Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information SystemShenzhen Graduate SchoolHarbin Institute of Technology518055 ShenzhenChina

Metalenses have emerged as a new optical element or system in recent years,showing superior performance and abundant applications.However,the phase distribution of a metalens has not been measured directly up to now,hindering further quantitative evaluation of its performance.We have developed an interferometric imaging phase measurement system to measure the phase distribution of a metalens by taking only one photo of the interference pattern.Based on the measured phase distribution,we analyse the negative chromatic aberration effect of monochromatic metalenses and propose a feature size of metalenses.Different sensitivities of the phase response to wavelength between the Pancharatnam-Berry phase-based metalens and propagation phase-reliant metalens are directly observed in the experiment.Furthermore,through phase distribution analysis,it is found that the distance between the measured metalens and the brightest spot of focusing will deviate from the focal length when the metalens has a low nominal numerical aperture,even though the metalens is ideal without any fabrication error.We also use the measured phase distribution to quantitatively characterise the imaging performance of the metalens.Our phase measurement system will help not only designers optimise the designs of metalenses but also fabricants distinguish defects to improve the fabrication process,which will pave the way for metalenses in industrial applications.

关键词： character distribution nominal

Non-Convex Optimization of Resource Allocation in Fog Computing Using Successive Approximation

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Journal of Systems Science & Complexity 2024年第2期37卷 805-840页

作者： LI Shiyong liu Huan LI wenzhe SUN Wei School of Economics and Management Yanshan UniversityQinhuangdao 066000China

Fog computing can deliver low delay and advanced IT services to end users with substantially reduced energy consumption.Nevertheless,with soaring demands for resource service and the limited capability of fog nodes,how to allocate and manage fog computing resources properly and stably has become the bottleneck.Therefore,the paper investigates the utility optimization-based resource allocation problem between fog nodes and end users in fog computing.The authors first introduce four types of utility functions due to the diverse tasks executed by end users and build the resource allocation model aiming at utility maximization.Then,for only the elastic tasks,the convex optimization method is applied to obtain the optimal results;for the elastic and inelastic tasks,with the assistance of Jensen’s inequality,the primal non-convex model is approximated to a sequence of equivalent convex optimization problems using successive approximation method.Moreover,a two-layer algorithm is proposed that globally converges to an optimal solution of the original problem.Finally,numerical simulation results demonstrate its superior performance and effectiveness.Comparing with other works,the authors emphasize the analysis for non-convex optimization problems and the diversity of tasks in fog computing resource allocation.

关键词： Fog computing non-convex optimization optimal resource allocation successive approximation method utility function

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燃煤机组锅炉负荷偏差分析模型与评价系统

锅炉技术 2024年第3期55卷 19-27页

作者：陈冬林蒋权胡章茂殷立国杨宁武刘文哲张博长沙理工大学能源与动力工程学院湖南长沙410114 中国大唐集团有限公司北京100033 大唐华银电力股份有限公司湖南长沙410111 湖南大唐先一科技有限公司湖南长沙410111

“双碳”大背景下我国上网新能源装机发展十分迅速。为了加大电网对新能源发电的消纳,燃煤发电机组频繁参与深度调峰导致了机组实际负荷与自动发电控制(AGC)指令负荷出现较大偏差。针对这一技术难题,以锅炉及其辅助设备为对象,研究构建... 详细信息

“双碳”大背景下我国上网新能源装机发展十分迅速。为了加大电网对新能源发电的消纳,燃煤发电机组频繁参与深度调峰导致了机组实际负荷与自动发电控制(AGC)指令负荷出现较大偏差。针对这一技术难题,以锅炉及其辅助设备为对象,研究构建了锅炉机组本体及其辅助设备的实际出力模型、应有出力模型和最大出力模型,建立了用以分析评价锅炉机组负荷偏差原因及诊断与预警的分析评价系统,并将该系统在电厂中进行了验证。结果表明:该分析评价系统可有效地对锅炉及其辅助设备的出力故障进行早期预警和诊断,可有效提高机组运行的可靠性、安全性与经济性。

关键词：燃煤机组锅炉负荷偏差系统开发

Asymmetrically ligated single atomic nickel sites for efficient hydrogen peroxide electrosynthesis

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Nano Research 2024年第3期17卷 1094-1100页

作者： Xusheng Cheng Jinwen Hu wenzhe Shang Jingya Guo Cuncun Xin Songlin Zhang Suchan Song Wei liu Yantao Shi State Key laboratory of Fine Chemicals Frontier Science Center for Smart MaterialsSchool of ChemistryDalian University of TechnologyDalian 116024China

Atomic transition-metal-nitrogen-carbon electrocatalysts hold great promise as alternatives to benchmark Pt in the oxygen reduction reaction.The pristine metal centers with quasi square-planar D_(4h) configuration,however,still suffer from unfavorable energetics and thereby strong activity/selectivity trade-off during the catalytic process.Here we present a ligand-field engineering of single-atom Ni-N-C catalysts to boost the sluggish kinetics via rationally constructing prototypical asymmetrically ligated Ni-N_(3)O_(1) sites.The as-obtained Ni-supported multi-walled carbon nanotubes with molten salt-treated(defined as Ni/CNS)catalyst delivered an excellent H_(2)O_(2) selectivity(>90%)within a wide potential window(0.2–0.7 V vs.reversible hydrogen electrode(RHE))and robust stability(for 10 h)in alkaline medium.Combined electron paramagnetic resonance and theoretical analysis rationalize this finding and demonstrate that the broken symmetry facilitates the electron transfer of a σ* to O–O orbital as compared to the Ni-N_(4) counterpart,playing an indispensable role in efficient O_(2) activation.

关键词： broken D4h single nickel sites oxygen reduction H_(2)O_(2)production

Annexin5 Is Essential for Pollen Development in Arabidopsis

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Molecular Plant 2014年第4期7卷 751-754页

作者： Jingen Zhu[a], Shunjie Yuan[a], Guo Wei[a], Dong Qian[a], Xiaorong Wu[a], Honglei Jia[a], Mengyuan Gui[b], wenzhe liu[b], Lizhe An[a], Yun Xiang[a], a MOE Key Laboratory of Cell Activities and Stress Adaptations School of Life Sciences Lanzhou University Lanzhou 730000 Chinab School of Life Sciences Northwest University Xi’an 710069 China

Pollen development is a post-meiotic process that produces mature pollen grains from microspores and can be regarded as an ideal model for the study of important plant physiological processes such as reproduction, cellular differentiation, cell fate determination, signal transduction, membrane transport, and fusion and polar growth. The regulation of pollen development is a complicated biological process that is crucial for sexual reproduction in flowering plants （Yamamoto et al.,

关键词： LIPOCORTINS POLLEN ARABIDOPSIS