Precise control of light polarization at the nanoscale is critical for accessing chiral optical responses and manipulating spin-photon interactions in advanced materials. Yet, conventional scattering-type near-field probes predominantly generate out-of-plane linear polarization and offer little control over phase or polarization state. Here, we introduce a polarization-engineered near-field methodology based on a combined metallic tip and planar dipole nanoantenna system. Using full-wave electromagnetic simulations, we show that the tip acts as a vertically oriented plasmonic resonator, while the antenna supports an in-plane dipolar mode. By tuning the tip-antenna geometry and tip height, the two orthogonal field components attain comparable amplitudes and a controllable ∼90° phase offset, producing circularly polarized nano-light in the antenna gap. The proposed system effectively functions as a nanoscale quarter-wave plate, converting linearly polarized illumination into circularly polarized hotspots without external polarization optics. This method establishes an experimentally accessible route toward polarization-programmable near-field nanoscopy, enabling chiral spectroscopy, selective excitation of spin/valley degrees of freedom, and quantum optical investigations at the nanoscale.

Microsphere nano-imaging is a promising technique for label-free and real-time imaging, making optical sub-diffraction resolution possible. Due to the limited size and high surface curvature of microspheres, the magnified imaging suffers from the limited depth of field and low contrast. The performance of this technique depends not only on the geometric parameters of microspheres but also on the illumination conditions of an optical system. In this work, a specially designed filter is added to the microscope to adjust the illumination angle and area on the microsphere. Experimental results demonstrate that with the filter, the imaging contrast is increased by 2.77 times, and the resolution is improved from 125 nm to 100 nm. It also increases the depth of field, extending it from 519 nm to 900 nm coupled with a 20× objective lens. This effective light manipulation strategy establishes suitable illumination conditions to enhance the imaging contrast and resolution. It is also applicable to improve the performance of microspheres in other optical applications.

Optical microscopy has a key role in research, development and quality control across a wide range of scientific, technological and medical fields. However, diffraction limits the spatial resolution of conventional optical instruments to about half the illumination wavelength. A technique that surpasses the diffraction limit in the wide spectral range between visible and terahertz frequencies is scattering-type scanning near-field optical microscopy (s-SNOM). The basis of s-SNOM is an atomic force microscope in which the tip is illuminated with light from the visible to the terahertz spectral range. By recording the elastically tip-scattered light while scanning the sample below the tip, s-SNOM yields near-field optical images with a remarkable resolution of 10 nm, simultaneously with the standard atomic force microscopic topography image. This resolution is independent of the illumination wavelength, rendering s-SNOM a versatile nanoimaging and nanospectroscopy technique for fundamental and applied studies of materials, structures and phenomena. This Review presents an overview of the fundamental principles governing the measurement and interpretation of near-field contrasts and discusses key applications of s-SNOM. We also showcase emerging developments that enable s-SNOM to operate under various environmental conditions, including cryogenic temperatures, electric and magnetic fields, electrical currents, strain and liquid environments. All these recent developments broaden the applicability of s-SNOMs for exploring fundamental solid-state and quantum phenomena, biological matter, catalytic reactions and more. Scattering-type scanning near-field optical microscopy (s-SNOM) enables nanoscale imaging and spectroscopy through elastic light scattering at a scanning probe tip. This Review highlights the fundamental principles, applications and recent advancements of s-SNOM across various sample environments.

Superconducting transition-edge sensors are renowned for their extraordinary photon sensitivity and energy resolution, finding applications spanning quantum information, astronomy, and nanophotonics. Here, we report the development of bolometric superconducting optical nanoscopy (BOSON), a novel platform that integrates bolometric detection at the superconducting transition edges with near-field optical techniques. BOSON enables the mapping of photoinduced changes in superconductivity with unprecedented spatial resolution and photon sensitivity. By incorporating BOSON with low-dimensional materials, we achieved polariton imaging at nanowatt excitation levels—at least 4 orders of magnitude lower than the power typically required in prior near-field nanoscopy experiments. Our findings highlight the potential for BOSON to advance scanning-probe-based optical platforms to enable the detection of photons, polaritons, and Cooper pair dynamics at the nanoscale. This paves the way for quantum sensing applications using single-polariton detection and can offer deeper insights into quasiparticle dynamics.

Nanophotonic cavities are the foundation for a broad spectrum of applications, including quantum sensing, on-chip communication, and cavity quantum electrodynamics. In van der Waals (vdW) materials, these cavities can harness polaritons, which are quasiparticles emerging from photon interactions with excitons, plasmons, or phonons that are confined in microscopic sample flakes. Hybrid phonon-plasmon cavities leverage the long lifetimes of phonons and good tunability of plasmons, but their reconfigurability remains fundamentally limited. Here, we introduce a magnetic-field-tuning mechanism for polaritonic cavities in a vdW heterostructure. Specifically, we demonstrate that the primary Landau transition in magnetized charge-neutral graphene can be harvested for controlling polaritonic cavity modes in a graphene-based phononic heterostructure. Additionally, we predict a magnetic-field-induced topological transition in the polariton isofrequency contour, causing a nontrivial cavity mode profile redistribution. Our study underscores the versatility of Landau-based nanophotonic cavities, offering new paradigms for the design and manipulation of light-matter interactions at the nanoscale.

Besides learning theoretical knowledge in class, participating in extracurricular activities is vital to students' life development. Interpersonal trust is the basis for university students to establish a good social network. However, there is little discussion on the mechanism analysis that affects university students' participation in the second classroom. To explore the impact of interpersonal trust on university students' participation in extracurricular activities, this study uses self-acceptance and self-esteem as mediating variables to make it a complete chain mediation model. Through a sample survey of university students, the chain mediation model is used to analyze the data. The results show that interpersonal trust, self-acceptance, and self-esteem significantly and positively impact university students' participation in extracurricular activities. In the chain mediation model, interpersonal trust positively affects university students’ second-classroom participation through the sequential mediators of self-acceptance and self-esteem. This hypothesized pathway was statistically supported by robust model fit indices, including Akaike’s Information Criterion (AIC) and Bayesian Information Criterion (BIC), derived from structural equation modeling (SEM). Universities should create an excellent interpersonal trust environment for students and cultivate their self-acceptance and self-esteem. Improving students' participation in the second classroom is conducive to promoting university students' physical and mental health and all-around development.

Charge transfer at material interfaces governs a wide range of physical properties, from electronic band structures to emergent collective excitations. In two-dimensional (2D) material heterostructures, charge transfer phenomena play important roles in enabling novel quantum phases, proximity effects, and tunable plasmonic responses. One representative charge transfer interface is formed between alpha-RuCl3, a van der Waals material with high electron affinity, and graphene. Significant charge transfer across this interface induces the formation of charge-transfer plasmon polaritons (CPPs), hybrid excitations between light and charge oscillations. However, previous studies found that as the charge transfer process takes place, alpha-RuCl3 becomes lossy, which limits the quality factor of CPPs. Here, we investigate CPPs down to 10 K using a home-built scattering-type scanning near-field optical microscope (s-SNOM) optimized for low-temperature measurements. Our study reveals a dramatic suppression of plasmon loss channels below 40 K, contributing to a significant enhancement in the plasmonic quality factor. This reduction in loss is likely attributed to the blue shift of the correlation-induced Mott gap in alpha-RuCl3 with decreasing temperature, along with the reduction of phonon scattering at low temperature. Our results highlight the potential of using s-SNOM and CPPs to study complex 2D interfaces and reveal correlated electron dynamics in the underlying material.

Online learning has been greatly widespread since the explosion of COVID-19. However, due to the lack of interaction between teachers and students in online courses, it is very difficult for students to focus on course content and complete the learning. Therefore, we developed a novel intelligent multilevel knowledge graph to help students quickly and systematically grasp the framework and key content of video lectures. Specifically, our method introduced cues into the interactive knowledge mapping. This approach not only allows students to interact with the graphs but also displays different levels of knowledge based on its importance. In addition, a quasi-experiment was implemented to verify the effectiveness of our method. Specifically, we compare the effects of knowledge graphs in three weighting strategies for cues with traditional manual concept maps on students' learning effectiveness and learning perception. Our study shows that although static artificial concept maps do enhance student learning to a certain extent compared to traditional learning, its development efficiency and enhancement of student learning outcomes are not ideal. In contrast, interactive graphs presenting overlay cues can effectively help students to restructure and systematize their knowledge, direct their attention and thus improve their learning outcomes.

Polaritons, i.e., hybrid quasi-particles of light and matter resonances, have been extensively investigated due to their potential to enhance light-matter interactions. Although polaritonic applications thrive in the mid-infrared range, their extension to the terahertz (THz) range remains limited. Here, we present paratellurite (alpha-TeO2) nanowires, a versatile material acting as a platform for different types of phonon polaritons. Utilizing synchrotron infrared nanospectroscopy from 10 to 24 THz, we uncover the polaritonic properties of alpha-TeO2 nanowires, showcasing their dual functionality as both a Fabry-P & eacute;rot cavity and a waveguide for surface phonon polaritons. Furthermore, near-field measurements with a free-electron laser as a THz source reveal a localized optical contrast down to 5.5 THz, an indication of hyperbolic bands. Our findings complement the repertoire of polaritonic materials, with significant implications for advancing THz technologies.

基于H大学2016-2021年毕业生数据,系统分析了农业高校博士毕业生的就业去向及就业特征.研究发现,农业高校博士毕业生职业选择仍以学术职业为主,多元化就业趋势不显著;行业选择上农业高校博士毕业生以从事涉农教育和科技为主,直接进入农林牧渔业的博士生占比较低;地区选择上受学术资本积累和地缘亲近因素等影响,农业高校博士毕业生就业地区具有明显的属地特征;出国出境上农科博士毕业生赴美仍是当前主流,表现出单一化态势.针对农业高校博士毕业生就业去向及特征分析,认为需要对接市场需求、优化学科结构布局,引导就业方向、强化涉农就业支持,提升能力素质、营造多元就业格局.

农民共同富裕是一段时期中国共同富裕的最大短板和制约瓶颈,知识经济社会背景下教育是改造优化农民进而实现农民共同富裕的根本出路.历史上,美国曾在全国各州广设赠地学院开展面向农民的农业工业化教育,实现了大学、农业、农民、政府等多主体互利多赢.从分流施教看,目前我国教育分流促农共富存在没有有效关注多数农民的流源问题、将农民教育置于最低层次的流层问题、多用非正规形式进行教育的流型问题、只顾眼前而忽视长远质量的流质问题和过分强调初级农产品农业的流向问题.面向三农现代化和强国建设,我国教育分流促农共富亟需构建培育新型农民、造就务工市民、幸福农民子代、促使农民回流、加快农民更新的系列促进机制,内外分流相互结合,改造提升和转化循环有机统一.推动五大系列机制良性运行,我国需要立法赋予高等教育承担转化农民的教育分流职能,建立以本科教育为主体的促农共富教育分流体系,实施配套教育改革和政策保障.

Magnetic fields can have profound effects on the motion of electrons in quantum materials. Two-dimensional electron systems subject to strong magnetic fields are expected to exhibit quantized Hall conductivity, chiral edge currents and distinctive collective modes referred to as magnetoplasmons and magnetoexcitons. Generating these propagating collective modes in charge-neutral samples and imaging them at their native nanometre length scales have thus far been experimentally elusive. Here we visualize propagating magnetoexciton polaritons at their native length scales and report their magnetic-field-tunable dispersion in near-charge-neutral graphene. Imaging these collective modes and their associated nano-electro-optical responses allows us to identify polariton-modulated optical and photo-thermal electric effects at the sample edges, which are the most pronounced near charge neutrality. Our work is enabled by innovations in cryogenic near-field optical microscopy techniques that allow for the nano-imaging of the near-field responses of two-dimensional materials under magnetic fields up to 7 T. This nano-magneto-optics approach allows us to explore and manipulate magnetopolaritons in specimens with low carrier doping via harnessing high magnetic fields. Dirac magnetoexcitons with non-trivial nanoscale electrodynamics are formed from the excitation of Landau levels in charge-neutral graphene. Here, the Dirac magnetoexciton dispersion is directly imaged up to 7 T via a magneto cryogenic near-field microscope.

(Received 2022; accepted 2023; published April 2023) The terahertz (THz) electrodynamics of few-layer WTe2 is dominated by the plasmon response. However, THz surface plasmons (SPs) with long wavelengths in two-dimensional exfoliated crystals are typically confined by the lateral geometry. Direct visualization of the plasmonic standing wave patterns is challenging due to the spatial confinement and low quality factor of the SP, especially for samples that are only a few monolayers thick. Here, we resolve subtle real-space features of the plasmonic response of WTe2 by augmenting more common scattering amplitude experiments with the phase contrast accomplished within the time-domain version of THz nanoimaging. Amplitude and phase images allow us to quantitatively evaluate the evolution of the plasmonic response at cryogenic temperatures in samples with variable thickness from 3 to 12 monolayers. The proposed imaging modality is universally applicable to the THz near-field nanoscopy of low-dimensional materials.

From a global perspective, after-school tutoring education, also known as shadow education, has developed rapidly since the beginning of this century. However, shadow education has also brought many practical problems, such as the increased burden on parents and children, and the unfairness in education. At present, the Chinese government is vigorously implementing the double reduction policy and has achieved remarkable practical results. This study focuses on the evolution of the government policy of shadow education in China. First, it analyzed the four stages of shadow education governance policy experience: the acquiescent survival stage, the encouraging development stage, the preliminary regulation stage, and the comprehensive rectification stage. Python was used for text mining the policies from different periods and analyzing the focus of the policies in different stages by obtaining high-frequency vocabulary. Then, the multiple streams theory was used to explore the policy evolution process and change mechanism. Finally, relevant recommendations have been discussed to address the gaps in the current shadow education governance policies. The study found that the objectives, scope of adjustment, and protection of rights and interests of China's shadow education governance policies have undergone significant changes over time. Through the constant interaction and interweaving of the stream of problems, the stream of politics, and the stream of policy, the window of opportunity for policy change was jointly promoted. The innovations of this article mainly include the following: First, the evolution of China's shadow education governance policies was systematically reviewed using text mining methods to compare the differences of governance policies at different stages and second, multiple streams theory was used as the theoretical framework to analyze the reasons for the focus of shadow education governance policy changes.

Despite several attempts made to analyze students’ socialization into academic discourse in relevant reviews, we still lack a topical study providing an overview of how students are apprenticed into academic communities through oral activities at post-secondary institutions. This study aims at contributing to a comprehensive overview of both theoretical and empirical studies in the field of academic discourse socialization (ADS). A systematic review approach was adopted due to the qualitative and quantitative research design and connections between theory and evidence. The material search of ADS literature published between 2000 and 2022 resulted in 72 studies in total. While the synthesis of theoretical studies reveal the extant definitions, categorization of characteristics and theoretical orientations, the empirical study findings compare differences in participants and contexts, research approaches, communication events, and academic outcomes. This review also discusses major areas of research concerning ADS, mainly types of socialization agents, students’ feedback, learners’ identity construction, and assessment of consequences of ADS. With limitations concluded, the review encourages further focused investigation into micro-macro connections, application of digital technologies, a wider range of participants, disciplines and contexts, multiple types of oral activities and perspectives, learners’ linguistic production as well as correlation of oral and written texts, and joint efforts from multiple sides.

Ferroelectricity, a spontaneous and reversible electric polarization, is found in certain classes of van der Waals (vdW) materials. The discovery of ferroelectricity in twisted vdW layers provides new opportunities to engineer spatially dependent electric and optical properties associated with the configuration of moiré superlattice domains and the network of domain walls. Here, we employ near-field infrared nano-imaging and nano-photocurrent measurements to study ferroelectricity in minimally twisted WSe 2 . The ferroelectric domains are visualized through the imaging of the plasmonic response in a graphene monolayer adjacent to the moiré WSe 2 bilayers. Specifically, we find that the ferroelectric polarization in moiré domains is imprinted on the plasmonic response of the graphene. Complementary nano-photocurrent measurements demonstrate that the optoelectronic properties of graphene are also modulated by the proximal ferroelectric domains. Our approach represents an alternative strategy for studying moiré ferroelectricity at native length scales and opens promising prospects for (opto)electronic devices.

Polaritons are light-matter quasiparticles that govern the optical response of quantum materials and enable their nanophotonic applications. We have studied a new type of polaritons arising in magnetized graphene encapsulated in hexagonal boron nitride (hBN). These polaritons stem from hybridization of Dirac magnetoexciton modes of graphene with waveguide phonon modes of hBN crystals. We refer to these quasiparticles as the Landau-phonon polaritons (LPPs). Using infrared magneto nanoscopy, we imaged LPPs and controlled their real-space propagation by varying the magnetic field. These LLPs have large in-plane momenta and are not bound by the conventional optical selection rules, granting us access to the "forbidden" inter-Landau level transitions (ILTs). We observed avoided crossings in the LPP dispersion - a hallmark of the strong coupling regime - occurring when the magnetoexciton and hBN phonon frequencies matched. Our LPP-based nanoscopy also enabled us to resolve two fundamental many-body effects: the graphene Fermi velocity renormalization and ILT-dependent magnetoexciton binding energies. These results indicate that magnetic-field-tuned Dirac heterostructures are promising platforms for precise nanoscale control and sensing of light-matter interaction.

Due to the two-dimensional character of graphene, the plasmons sustained by this material have been invariably studied in supported samples so far. The substrate provides stability for graphene but often causes undesired interactions (such as dielectric losses, phonon hybridization, and impurity scattering) that compromise the quality and limit the intrinsic flexibility of graphene plasmons. Here, we demonstrate the visualization of plasmons in suspended graphene at room temperature, exhibiting high-quality factor Q ~33 and long propagation length > 3 μm. We introduce the graphene suspension height as an effective plasmonic tuning knob that enables in situ change of the dielectric environment and substantially modulates the plasmon wavelength, propagation length, and group velocity. Such active control of micrometer plasmon propagation facilitates near-unity-order modulation of nanoscale energy flow that serves as a plasmonic switch with an on-off ratio above 14. The suspended graphene plasmons possess long propagation length, high tunability, and controllable energy transmission simultaneously, opening up broad horizons for application in nano-photonic devices.

The ability to perform nanometer-scale optical imaging and spectroscopy is key to deciphering the low-energy effects in quantum materials, as well as vibrational fingerprints in planetary and extraterrestrial particles, catalytic substances, and aqueous biological samples. These tasks can be accomplished by the scattering-type scanning near-field optical microscopy (s-SNOM) technique that has recently spread to many research fields and enabled notable discoveries. Herein, it is shown that the s-SNOM, together with scanning probe research in general, can benefit in many ways from artificial-intelligence (AI) and machine-learning (ML) algorithms. Augmented with AI- and ML-enhanced data acquisition and analysis, scanning probe optical nanoscopy is poised to become more efficient, accurate, and intelligent.