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Synthesis and Modulation of Low-Dimensional Transition Metal Chalcogenide Materials via Atomic Substitution

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Nano-Micro Letters 2024年第9期16卷 49-94页

作者： Xuan Wang Akang Chen XinLei Wu Jiatao Zhang Jichen Dong Leining Zhang Key laboratory of Cluster Science Ministry of Education of ChinaBeijing Key Laboratory of Photoelectronic and Electrophonic Conversion MaterialsSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081People’s Republic of China Beijing National laboratory for Molecular Sciences Key Laboratory of Organic SolidsInstitute of Chemistry Chinese Academy of SciencesBeijing 100190People’s Republic of China

In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk *** controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various *** this context,the atomic substitution method has emerged as a favorable *** involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting *** this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC *** effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are *** enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these ***,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.

关键词： Transition metal chalcogenides Atomic substitution Ion exchange Low-dimensional materials Controllable synthesis

A credible traffic prediction method based on self-supervised causal discovery

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Science China(Information Sciences) 2024年第5期67卷 244-258页

作者： Dan WANG Yingjie LIU Bin SONG State Key laboratory of Integrated Services Networks Xidian University

Next-generation wireless network aims to support low-latency, high-speed data transmission services by incorporating artificial intelligence(AI) technologies. To fulfill this promise, AI-based network traffic prediction is essential for pre-allocating resources, such as bandwidth and computing power. This can help reduce network congestion and improve the quality of service(QoS) for users. Most studies achieve future traffic prediction by exploiting deep learning and reinforcement learning, to mine spatio-temporal correlated variables. Nevertheless, the prediction results obtained only by the spatio-temporal correlated variables cannot reflect real traffic changes. This phenomenon prevents the true prediction variables from being inferred, making the prediction algorithm perform poorly. Inspired by causal science, we propose a novel network traffic prediction method based on self-supervised spatio-temporal causal discovery(SSTCD). We first introduce the Granger causal discovery algorithm to build a causal graph among prediction variables and obtain spatio-temporal causality in the observed data, which reflects the real reasons affecting traffic ***, a graph neural network(GNN) is adopted to incorporate causality for traffic prediction. Furthermore,we propose a self-supervised method to implement causal discovery to to address the challenge of lacking ground-truth causal graphs in the observed data. Experimental results demonstrate the effectiveness of the SSTCD method.

关键词： wireless network traffic prediction causal discovery self-supervised

Broadband high-efficiency plasmonic metalens with negative dispersion characteristic

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Photonics Research 2024年第4期12卷 813-820页

作者： YONG-QIANG LIU YONG ZHU HONGCHENG YIN JINHAI SUN YAN WANG YONGXING CHE National Key laboratory of Scattering and Radiation Beijing 100854China

Controlling the dispersion characteristic of metasurfaces(or metalenses) along a broad bandwidth is of great importance to develop high-performance broadband metadevices. Different from traditional lenses that rely on the material refractive index along the light trajectory, metasurfaces or metalenses provide a new regime of dispersion control via a sub-wavelength metastructure, which is known as negative chromatic ***, broadband metalenses design with high-performance focusing especially with a reduced device dimension is a significant challenge in society. Here, we design, fabricate, and demonstrate a broadband highperformance diffractive-type plasmonic metalens based on a circular split-ring resonator metasurface with a relative working bandwidth of 28.6%. The metalens thickness is only 0.09λ0(λ0is at the central wavelength),which is much thinner than previous broadband all-dielectric metalenses. The full-wave simulation results show that both high transmissive efficiency above 80%(the maximum is even above 90%) and high average focusing efficiency above 45%(the maximum is 56%) are achieved within the entire working bandwidth of 9–12 ***, an average high numerical aperture of 0.7(NA = 0.7) of high-efficiency microwave metalens is obtained in the simulations. The broadband high-performance metalens is also fabricated and experimental measurements verify its much higher average focusing efficiency of 55%(the maximum is above 65% within the broad bandwidth) and a moderate high NA of 0.6. The proposed plasmonic metalens can facilitate the development of wavelength-dependent broadband diffractive devices and is also meaningful to further studies on arbitrary dispersion control in diffractive optics based on plasmonic metasurfaces.

关键词： resonator dispersion high

Learnware:small models do big

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Science China(Information Sciences) 2024年第1期67卷 39-50页

作者： Zhi-Hua ZHOU Zhi-Hao TAN National Key laboratory for Novel Software Technology Nanjing University

There are complaints about current machine learning techniques such as the requirement of a huge amount of training data and proficient training skills,the difficulty of continual learning,the risk of catastrophic forgetting,and the leaking of data privacy/*** research efforts have been focusing on one of those concerned issues separately,paying less attention to the fact that most issues are entangled in *** prevailing big model paradigm,which has achieved impressive results in natural language processing and computer vision applications,has not yet addressed those issues,whereas becoming a serious source of carbon *** article offers an overview of the learnware paradigm,which attempts to enable users not to need to build machine learning models from scratch,with the hope of reusing small models to do things even beyond their original purposes,where the key ingredient is the specification which enables a trained model to be adequately identified to reuse according to the requirement of future users who know nothing about the model in advance.

关键词： artificial intelligence machine learning learnware

Dynamic interactive bitwise meta-holography with ultra-high computational and display frame rates

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Opto-Electronic Advances 2024年第1期7卷 36-46页

作者： Yuncheng Liu Ke Xu Xuhao Fan Xinger Wang Xuan Yu Wei Xiong Hui Gao Wuhan National laboratory for Optoelectronics and School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Optics Valley laboratory Wuhan 430074China

Interactive holography offers unmatched levels of immersion and user engagement in the field of future *** of the substantial progress has been made in dynamic meta-holography,the realization of real-time,highly smooth interactive holography remains a significant challenge due to the computational and display frame rate *** this study,we introduced a dynamic interactive bitwise meta-holography with ultra-high computational and display frame *** our knowledge,this is the first reported practical dynamic interactive metasurface holographic *** spa-tially divided the metasurface device into multiple distinct channels,each projecting a reconstructed *** switching states of these channels were mapped to bitwise operations on a set of bit values,which avoids complex holo-gram computations,enabling an ultra-high computational frame *** approach achieves a computational frame rate of 800 kHz and a display frame rate of 23 kHz on a low-power Raspberry Pi computational *** to this methodology,we demonstrated an interactive dynamic holographic Tetris game system that allows interactive gameplay,color display,and on-the-fly hologram *** technology presents an inspiration for advanced dynamic meta-holography,which is promising for a broad range of applications including advanced human-computer interaction,real-time 3D visualization,and next-generation virtual and augmented reality systems.

关键词： interactive display meta-holography bitwise operation ultra-high frame rate

Analysis of Piezoelectric Semiconductor Structures Considering Both Physical and Geometric Nonlinearities

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Acta Mechanica Solida Sinica 2024年第1期37卷 72-81页

作者： Zhengguang Xiao Shuangpeng Li Chunli Zhang Key laboratory of Soft Machines and Smart Devices of Zhejiang Province Department of Engineering MechanicsZhejiang UniversityHangzhou 310027China Huanjiang laboratory Zhuji 311816China

Piezoelectric semiconductors(PSs),such as ZnO and GaN,known as the third-generation semiconductors,have promising applications in electronic and optoelectronic devices due to the coexistence and interaction of piezoelectricity and semiconductor *** modeling of PS structures under external loads,such as thermal and mechanical loads,plays a crucial role in the design of PS *** this work,we propose a nonlinear fully coupling theoretical model and investigate the multi-field coupling behaviors of PS structures and PN junctions under thermal and mechanical loads,considering physical and geometric *** electromechanical and semiconducting behaviors of a PS rod-like structure with flexural deformations under different combinations of temperature changes and mechanical loads are *** tuning effect of temperature changes and mechanical loads on multi-field coupling behaviors of PSs is *** current–voltage characteristics of PS PN junctions are studied under different combinations of temperature changes and mechanical *** obtained results are helpful for the development of novel PS devices.

关键词： Piezoelectric semiconductor Nonlinearity Multi-field Coupling Tuning

Role of cancer stem cell ecosystem on breast cancer metastasis and related mouse models

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Zoological Research 2024年第3期45卷 506-517页

作者： Xilei Peng Haonan Dong Lixing Zhang Suling Liu Fudan University Shanghai Cancer Center&Institutes of Biomedical Sciences/State Key laboratory of Genetic Engineering/Cancer Institutes/Department of Oncology/Key laboratory of Breast Cancer in Shanghai/Shanghai Key laboratory of Medical Epigenetics/Shanghai Key laboratory of Radiation Oncology/International Co-laboratory of Medical Epigenetics and Metabolism Ministry of Science and Technology/Shanghai Medical College/Fudan UniversityShanghai 200032China

Breast cancer metastasis is responsible for most breast cancer-related deaths and is influenced by many factors within the tumor ecosystem,including tumor cells and *** cancer stem cells(BCSCs)constitute a small population of cancer cells with unique characteristics,including their capacity for self-renewal and *** have shown that BCSCs not only drive tumorigenesis but also play a crucial role in promoting metastasis in breast *** tumor microenvironment(TME),composed of stromal cells,immune cells,blood vessel cells,fibroblasts,and microbes in proximity to cancer cells,is increasingly recognized for its crosstalk with BCSCs and role in BCSC survival,growth,and dissemination,thereby influencing metastatic ***,a thorough understanding of BCSCs and the TME is critical for unraveling the mechanisms underlying breast cancer *** this review,we summarize current knowledge on the roles of BCSCs and the TME in breast cancer metastasis,as well as the underlying regulatory ***,we provide an overview of relevant mouse models used to study breast cancer metastasis,as well as treatment strategies and clinical trials addressing BCSC-TME interactions during ***,this study provides valuable insights for the development of effective therapeutic strategies to reduce breast cancer metastasis.

关键词： Breast cancer Metastasis Cancer stem cell Ecosystem Tumor microenvironment Mouse model

Applications of genetic code expansion technology in eukaryotes

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Protein & Cell 2024年第5期15卷 331-363页

作者： Qiao-ru Guo Yu J.Cao State Key laboratory of Chemical Oncogenomic Guangdong Provincial Key Laboratory of Chemical GenomicsPeking University Shenzhen Graduate SchoolShenzhen 518055China Institute of Chemical Biology Shenzhen Bay LaboratoryShenzhen 518132China

Unnatural amino acids(UAAs)have gained significant attention in protein engineering and drug development owing to their ability to introduce new chemical functionalities to *** eukaryotes,genetic code expansion(GCE)enables the incorporation of UAAs and facilitates posttranscriptional modification(PTM),which is not feasible in prokaryotic *** is also a powerful tool for cell or animal imaging,the monitoring of protein interactions in target cells,drug development,and switch ***,there is keen interest in utilizing GCE in eukaryotic *** review provides an overview of the application of GCE in eukaryotic systems and discusses current challenges that need to be addressed.

关键词： genetic code expansion unnatural amino acid eukaryotes basic research therapeutic applications

Efficient stochastic parallel gradient descent training for on-chip optical processor

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Opto-Electronic Advances 2024年第4期7卷 5-15页

作者： Yuanjian Wan Xudong Liu Guangze Wu Min Yang Guofeng Yan Yu Zhang Jian Wang Wuhan National laboratory for Optoelectronics and School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Optics Valley laboratory Wuhan 430074China

In recent years,space-division multiplexing(SDM)technology,which involves transmitting data information on multiple parallel channels for efficient capacity scaling,has been widely used in fiber and free-space optical communication *** enable flexible data management and cope with the mixing between different channels,the integrated reconfig-urable optical processor is used for optical switching and mitigating the channel ***,efficient online train-ing becomes intricate and challenging,particularly when dealing with a significant number of *** we use the stochastic parallel gradient descent(SPGD)algorithm to configure the integrated optical processor,which has less com-putation than the traditional gradient descent(GD)*** design and fabricate a 6×6 on-chip optical processor on silicon platform to implement optical switching and descrambling assisted by the online training with the SPDG ***,we apply the on-chip processor configured by the SPGD algorithm to optical communications for optical switching and efficiently mitigating the channel crosstalk in SDM *** comparison with the traditional GD al-gorithm,it is found that the SPGD algorithm features better performance especially when the scale of matrix is large,which means it has the potential to optimize large-scale optical matrix computation acceleration chips.

关键词： optical communications optical signal processing channel descrambling optical neural network chip silicon photonics