摘要：Nanomaterials have garnered recognition for their notable surface effects and demonstration of superior mechanical *** studies on the surface effects of nanomaterials,employing the finite element method,often relied on simplified twodimensional models due to theoretical ***,these simplified models inadequately represent the mechanical properties of nanomaterials and fail to capture the substantial impact of surface effects,particularly the curvature dependence of *** study applies the principle of minimum energy and leverages the Steigmann-Ogden surface theory of nanomaterials to formulate a novel finite element surface element that comprehensively accounts for surface *** conducted an analysis of the stress distribution and deformation characteristics of four typical 2D and 3D nanomaterial *** accuracy of the developed surface element and finite element calculation method was verified through comparison with established *** resulting finite element model provides a robust and compelling scientific approach for accurately predicting the mechanical performance of nanomaterials.

摘要：Phase transformation of two-dimensional(2D)nanomaterials can lead to significant changes in electronic and optical properties,which enables the development of novel *** strategies for phase engineering of 2D nanomaterials have drawn considerable attention in recent *** review focuses on the state-of-the-art progress in the phase transformation of 2D nanomaterials and their catalytic ***,the basic concepts of phase transformation and the outstanding electronic and optical properties induced by phase transformation are briefly ***,different strategies for achieving phase transformation are discussed in detail and classified into several types based on their characteristics,including(i)doping,(ii)external fields,(iii)optical irradiation,(iv)strain effect,(v)high-energy particle excitation,and(vi)thermal *** applications of 2D nanomaterials in catalysis based on phase transformation have also been ***,a summary of the technical challenges to phase control in 2D nanomaterials and potential opportunities for developing novel applications is presented.

摘要：The nitrogen-coordinated metal single-atom catalysts(M−N−C SACs)with an ultra-high metal loading synthetized by direct high-temperature pyrolysis have been widely ***,most of metal single atoms in these catalysts were buried in the carbon matrix,resulting in a low metal utilization and inaccessibility for adsorption of reactants during the catalytic ***,we reported a facile synthesis based on the hard-soft acid-base(HSAB)theory to fabricate Co single-atom catalysts with highly exposed metal atoms ligated to the external pyridinic-N sites of a nitrogen-doped carbon *** from the highly accessible Co active sites,the prepared Co−N−C SAC exhibited a superior oxygen reduction reactivity comparable to that of the commercial Pt/C catalyst,showing a high turnover frequency(TOF)of 0.93 e^(−)·s^(-1)·site^(-1)at 0.85 V ***,far exceeding those of some representative SACs with a ultra-high metal *** work provides a rational strategy to design and prepare M−N−C single-atom catalysts featured with high site-accessibility and site-density.

摘要：Molybdenum-based catalysts have demonstrated significant potential in the electrocatalytic hydrogen evolution reaction(HER).However,the limited exposure of active sites and strong hydrogen adsorption result in suboptimal ***,a Mo_(2)N±MoSe_(2) heterojunction is prepared on carbon cloth(MNS/CC)to enhance the *** strong electronic interaction between Mo_(2)N and MoSe_(2),combined with the lower work function of Mo_(2)N,creates an intrinsic electric field at the heterojunction interface,which markedly improves charge transfer ***,the optimized electronic structure of Mo sites further enhances charge transfer and intrinsically catalytic activity in *** a result,MNS/CC requires overpotentials of mere 65 and 210 mV to achieve current densities of 20 mA cm^(−2) and 1 A cm^(−2),respectively,with a Tafel slope of only 96 mV dec−***,MNS/CC maintains stable operation at 1 A cm^(−2) for 240 h without significant *** results offer insights into the design of non-precious metal-based electrocatalysts for industrial hydrogen production.

摘要：A kind of closed-loop Hall effect sensor is designed and fabricated by considering several factors such as iron core material, Hall device, as well as selected integrated circuit. Through studying the effect of the iron material and structures of current sensor, a kind of optimal Hall effect current sensor is found. The experimental results show that the presented closed-loop Hall effect current sensor achieves 1 mA/A sensitivity. And its lineafity and accuracy are 0.1% and 0.35% FS, respectively, at cur- rents ranging from 0 to 50 A.

摘要：There is a comm on sense view for atomic magnetometers that their spin-projection-noises(SPNs) are inversely proportional to (T_2)^(1/2), where (T_2)^(1/2) is the transverse relaxation time. We analyze the current atomic magnetometer types and give a counter-example of this common sense, which is the all-optical spin precession modulated threeaxis atomic magnetometer proposed by our group in 2015. Unlike the other atomic magnetometers, the SPN of this kind of atomic magnetometers is proportional to (T_2)^(1/2) due to the fact that the scale factor between P_x and B can be unrelated to the transverse relaxation time T_2. We demonstrate this irrelevance experimentally and analyze the SPN theoretically. Using short-pulse ultra-high power laser to fully polarize the atoms, the phenomenon that SPN decreases with T_2 may also be demonstrated experimentally and a new tool for researching SPN in atomic magnetometers may be realized.

摘要：This paper discusses the design and implementation of a low cost multi-sensor integrated attitude determination system for small unmanned aerial vehicles( UAVs),which uses strapdown inertial navigation system( SINS) based on micro electromechanical system( MEMS) inertial sensors,commercial GPS receiver,and 3-axis ***-SINS initial attitude determination cannot be well performed for the reason that the MEMS inertial sensors biases are time-varying and poor repeatability,therefore in this paper the magnetometer and inclinometer are used to assist the MEMS-SINS initial attitude determination and MEMS inertial sensors field ***,the attitude determination algorithms are presented to estimate the full attitude during GPS signal outage and non-accelerating ***,the attitude information estimation results are compared with the reference of the non-magnetic marble platform and 3-axis *** the attitude estimation precision satisfies the requirement of attitude measurement for small UAVs during GPS signal outage and ***,the small UAV autonomous flight test results show that the low cost and real-time attitude determination system can yield continuous,reliable and effective attitude information for small UAVs.

摘要：Fano-like quantum routing of single photons in a system with two waveguides coupled to two collocated atoms is investigated theoretically. Using a full quantum theory in real space, photonic scattering amplitudes along four ports of the waveguide network are analytically obtained. It is shown that, by adjusting the atomic dipole-dipole interaction, an evident Fano-line shape emerges in the scattering spectra of the single-dot configuration system. Moreover, Fano resonance can also be achieved by varying the atom-waveguide coupling strength and atomic detuning, in the presence of the atomic dipole-dipole interaction. Therefore, the atomic dipole-dipole interaction may be utilized as a possible way to control spectral Fano-like resonance. The feasibility with the experimental waveguide channels is also discussed.

摘要：Nihility material is a medium whose relative permittivity and permeability tend to zero simultaneously. In this work, comparing with the scattering properties of perfect nihility nanoparticles （made from nihility material）, we provide an optimization design of electromagnetic nihility nanoparticles, which is a coated hybrid nanosphere constituted by commutative c-negative （ENG） and μ-negative （MNG） media. Compared to a single ENG or MNG nanosphere, it is found that the total and back scattering spectra of coated hybrid nanospheres are much closer to those of perfect nihility nanospheres. Moreover, it is observed that the scattered electromagnetic field distribution of coated hybrid nanospheres is identical to that of perfect nihility nanospheres. These results indicate that the combination of commutative ENG and MNG media can constitute a composite structure which gives the closest approximation of electromagnetic scattering of perfect nihility nanospheres in a wide frequency range.

摘要：The separator is a key component of sodium-ion battery,which greatly affects the electrochemical performances and safety characteristics of the *** glass fiber separator cannot meet the requirements of large-scale application because of high cost and poor mechanical ***,the novel composite separators are prepared by a simple slurry sieving process using glass fiber separator scraps and ordinary qualitative filter paper as raw *** the composite mass ratio is 1:1,the composite separator has excellent comprehensive properties,including tensile strength of 15.8 MPa,porosity of 74.3%,ionic conductivity of 1.57×10^(-3)S·cm^(-1)and thermal stability at 210℃.The assembled sodium-ion battery shows superior cycling performance(capacity retention of 94.1%after 500 cycles at 1C)and rate capacity(retention rate of 87.3%at 10C),and it maintains fine interface *** above results provide some new ideas for the separator design of high-performance and low-cost sodium-ion batteries.