Design of Principal-agent Incentive Mechanism between Government and NPO

Based on principal-agent theory,this paper establishes an incentive contract mechanism between government and NPO under asymmetric information,and analyzes the impact of absolute risk aversion and output level on the expected utility of government,NPO and society.Research shows that risk aversion is negatively correlated with the expected utility of government,NPO and society.The output coefficient is positively correlated with the expected utility of government,NPO and society.Reducing absolute risk aversion,increasing output coefficient and increasing government incentives can effectively motivate NPO to actively participate in social rescue activities.

Coordination Model of Consumer Information Sharing in the Online Tourism Supply Chain

This is a study of the coordination model of consumer information sharing in the tourism supply chain with e-commerce platforms as the core.On the basis of considering the risks,a game theory is used to explore the information sharing effort level and the output profit of the tourism supply chain under both,centralized decision-making and decentralized decision-making.Finally,numerical simulation is used to verify the model and put forward a method of coordination for all parties in the tourism supply chain to achieve maximum profit.

Financial Coordination and Income Distribution of Agricultural Supply Chain

The agriculture field is a fundamental industry which supports the rapid development of the nation?s economy.However,credit constraints faced by farmers have restricted the modernization in the agricultural industry.The agricultural supply chain finance is effective in promoting rural industrial revitalization and agricultural modernization,which is of great significance to the transformation and development of rural economy and agriculture in China.In this paper,the financial coordination model in agricultural supply chain is constructed,and the income distribution model of Shapley value method is introduced.The results showed that the agricultural supply chain finance can significantly improve the income of the participants in the agricultural industrial chain and verify the economic feasibility of agricultural supply chain finance.

健康中国背景下城市社区老年体育服务供给的反思与优化策略

本文运用文献资料法、问卷调查法、逻辑分析法等,通过对城市社区老年人公共体育服务需求及供给现状的调查研究,探讨了老年人公共体育服务供给存在的问题及原因,并从政策引导、社区体育公共服务体系建设及社区体育多元共治等方面提出了优化策略,以期为城市社区老年人公共体育服务的发展提供思路和参考。

新型电化学传感器在生物分子检测中的研究进展

随着“提高全民健康素养”的号召深入人心,自主健康监测的需求也逐渐扩大,代谢物分析在健康管理过程中占据不可替代的重要作用。与质谱法、色谱法和光谱法等传统分析技术相比,电化学传感器因其选择性强、灵敏度高和检测范围宽,在生物医学、环境科学、材料科学等领域均显示出巨大的应用潜力。目前,科研工作者已经开发出多种面向生物代谢物检测的电化学传感器,用于确定离体体液中疾病标志物的水平或进行在体实时动态监测。以生物分子检测为切入点,综述了便携式、植入式和可穿戴式新型电化学传感器在疾病相关代谢物分析中的应用进展,并对这些传感装置进行总结和比较,以期为生物传感器的创新及临床应用拓展提供参考。

Refractive index sensing based on a twisted nano-kirigami metasurface

Plasmonic sensing technology has attracted considerable attention for high sensitivity due to the ability to effectively localize and manipulate light.In this study,we demonstrate a refractive index(RI)sensing scheme based on open-loop twisted meta-molecule arrays using the versatile nano-kirigami principle.RI sensing has the features of a small footprint,flexible control,and simple preparation.By engineering the morphology of meta-molecules or the RI of the ambient medium,the chiral surface lattice resonances can be significantly enhanced,and the wavelength,intensity,and sign of circular dichroism(CD)can be flexibly tailored.Utilizing the relation between the wavelength of the CD peak and the RI of the superstrate,the RI sensor achieves a sensitivity of 1133 nm/RIU.Additionally,we analyze these chiroptical responses by performing electromagnetic multipolar decomposition and electric field distributions.Our study may serve as an ideal platform for applications of RI measurement and provide new insights into the manipulation of chiral light–matter interactions.

Light-induced tumor theranostics based on chemical-exfoliated borophene

Among 2D materials(Xenes)which are at the forefront of research activities,borophene,is an exciting new entry due to its uniquely varied optical,electronic,and chemical properties in many polymorphic forms with widely varying band gaps including the lightest 2D metallic phase.In this paper,we used a simple selective chemical etching to prepare borophene with a strong near IR light-induced photothermal effect.The photothermal efficiency is similar to plasmonic Au nanoparticles,with the added benefit of borophene being degradable due to electron deficiency of boron.We introduce this selective chemical etching process to obtain ultrathin and large borophene nanosheets(thickness of ~4 nm and lateral size up to ~600 nm)from the precursor of AlB_(2).We also report first-time observation of a selective Acid etching behavior showing HCl etching of Al to form a residual B lattice,while HF selectively etches B to yield an Al lattice.We demonstrate that through surface modification with polydopamine(PDA),a biocompatible smart delivery nanoplatform of B@PDA can respond to a tumor environment,exhibiting an enhanced cellular uptake efficiency.We demonstrate that borophene can be more suitable for safe photothermal theranostic of thick tumor using deep penetrating near IR light compared to gold nanoparticles which are not degradable,thus posing longterm toxicity concerns.With about 40 kinds of borides,we hope that our work will open door to more discoveries of this top-down selective etching approach for generating borophene structures with rich unexplored thermal,electronic,and optical properties for many other technological applications.

Reconfigurable nano-kirigami metasurfaces by pneumatic pressure

Tunable/reconfigurable metasurfaces that can actively control electromagnetic waves upon external stimuli are of great importance for practical applications of metasurfaces.Here,we demonstrate a reconfigurable nano-kirigami metasurface driven by pneumatic pressure operating in the near-infrared wavelength region.The metasurfaces consist of combined Archimedean spirals and are fabricated in a free-standing gold/silicon nitride nanofilm by employing focused ion beam(FIB)lithography.The deformable spirals are instantly transformed from two dimensional(2 D)to three-dimensional(3 D)by the FIB-based nano-kirigami process.The 2 D–to–3 D transformation induces a dramatic irreversible change of the plasmonic quadruple modes and results in significant modulation in reflection by 137%.The suspended porous nano-kirigami metasurface is further integrated with an optofluidics device,with which the optical resonance is reversibly modulated by the pneumatic pressure.This work provides a strategy for tunable/reconfigurable metasurfaces,which are useful to build a promising lab-ona-chip platform for microfluidics,biological diagnostics,chemical sensing,and pressure monitoring.

Ray-optics model for optical force and torque on a spherical metal-coated Janus microparticle

In this paper, we develop a theoretical method based on ray optics to calculate the optical force and torque on a metallo-dielectric Janus particle in an optical trap made from a tightly focused Gaussian beam. The Janus particle is a 2.8 μm diameter polystyrene sphere half-coated with gold thin film several nanometers in thickness. The calculation result shows that the focused beam will push the Janus particle away from the center of the trap,and the equilibrium position of the Janus particle, where the optical force and torque are both zero, is located in a circular orbit surrounding the laser beam axis. The theoretical results are in good agreement qualitatively and quantitatively with our experimental observation. As the ray-optics model is simple in principle, user friendly in formalism, and cost effective in terms of computation resources and time compared with other usual rigorous electromagnetics approaches, the developed theoretical method can become an invaluable tool for understanding and designing ways to control the mechanical motion of complicated microscopic particles in various optical tweezers.

Microscopic and macroscopic manipulation of gold nanorod and its hybrid nanostructures[Invited]

Gold nanorods(GNRs)have potential applications ranging from biomedical sciences and emerging nanophotonics.In this paper,we will review some of our recent studies on both microscopic and macroscopic manipulation of GNRs.Unique properties of GNR nanoparticles,such as efficient surface plasmon amplifications effects,are introduced.The stable trapping,transferring,positioning and patterning of GNRs with nonintrusive optical tweezers will be shown.Vector beams are further employed to improve the trapping performance.On the other hand,alignment of GNRs and their hybrid nanostructures will be described by using a film stretch method,which induces the anisotropic and enhanced absorptive nonlinearities from aligned GNRs.Realization and engineering of polarized emission from aligned hybrid GNRs will be further demonstrated,with relative excitation–emission efficiency significantly enhanced.Our works presented in this review show that optical tweezers possess great potential in microscopic manipulation of metal nanoparticles and macroscopic alignment of anisotropic nanoparticles could help the macroscopic samples to flexibly represent the plasmonic properties of single nanoparticles for fast,cheap,and high-yield applications.

Strongly nonlinear topological phases of cascaded topoelectrical circuits

Circuits provide ideal platforms of topological phases and matter,yet the study of topological circuits in the strongly nonlinear regime,has been lacking.We propose and experimentally demonstrate strongly nonlinear topological phases and transitions in one-dimensional electrical circuits composed of nonlinear capacitors.Nonlinear topological interface modes arise on domain walls of the circuit lattices,whose topological phases are controlled by the amplitudes of nonlinear voltage waves.Experimentally measured topological transition amplitudes are in good agreement with those derived from nonlinear topological band theory.Our prototype paves the way towards flexible metamaterials with amplitude-controlled rich topological phases and is readily extendable to two and three-dimensional systems that allow novel applications.