Highly Active Interfacial Sites in SFT-SnO_(2) Heterojunction Electrolyte for Enhanced Fuel Cell Performance via Engineered Energy Bands:Envisioned Theoretically and Experimentally

Extending the ionic conductivity is the pre-requisite of electrolytes in fuel cell technology for high-electrochemical performance.In this regard,the introduction of semiconductor-oxide materials and the approach of heterostructure formation by modulating energy bands to enhance ionic conduction acting as an electrolyte in fuel cell-device.Semiconductor(n-type;SnO_(2))plays a key role by introducing into p-type SrFe_(0.2)Ti_(0.8)O_(3-δ)(SFT)semiconductor perovskite materials to construct p-n heterojunction for high ionic conductivity.Therefore,two different composites of SFT and SnO_(2)are constructed by gluing p-and n-type SFT-SnO_(2),where the optimal composition of SFT-SnO_(2)(6∶4)heterostructure electrolyte-based fuel cell achieved excellent ionic conductivity 0.24 S cm^(-1)with power-output of 1004 mW cm^(-2)and high OCV 1.12 V at a low operational temperature of 500℃.The high power-output and significant ionic conductivity with durable operation of 54 h are accredited to SFT-SnO_(2)heterojunction formation including interfacial conduction assisted by a built-in electric field in fuel cell device.Moreover,the fuel conversion efficiency and considerable Faradaic efficiency reveal the compatibility of SFT-SnO_(2)heterostructure electrolyte and ruled-out short-circuiting issue.Further,the first principle calculation provides sufficient information on structure optimization and energy-band structure modulation of SFT-SnO_(2).This strategy will provide new insight into semiconductor-based fuel cell technology to design novel electrolytes.

An Ultra-Compact Broadband Polarizing Beam Splitter Utilizing Hybrid Plasmonic Waveguide

Polarizing beam splitter has rather significant applications in polarization diversity circuits and polarization multiplexing systems.In this paper,we present an asymmetric polarizing beam splitter utilizing hybrid plasmonic waveguide.The special hybrid structure with a hybrid waveguide and a dielectric waveguide can limit the energy of TE and TM modes to a different layer.Therefore,we can achieve beam splitting by adjusting the corresponding parameters of the two waveguides.First,we studied the influences of different structure parameters on the real part of the effective mode refractive index of the two waveguides,and obtained a set of parameters that satisfy the condition of strong coupling of TM mode and weak coupling of TE mode.Then,the performance of our proposed polarizing beam splitter is evaluated numerically.The length of the coupling section is only 4.1μm,and the propagation loss of TM and TE modes is 0.0025 d B/μm and 0.0031 d B/μm respectively.Additionally,the extinction ratios of TM and TE modes are 10.62 d B and 12.55 d B,respectively.Particularly,the proposed device has excellent wavelength insensitivity.Over the entire C-band,the fluctuation of the whole normalized output power is less than 0.03.In short,our proposed asymmetric polarizing beam splitter features ultra-compactness,low propagation loss,and broad bandwidth,which would provide promising applications in polarization multiplexing system and polarization diversity circuits relevant to optical interconnection.

A review of crosstalk research for plasmonic waveguides

Plasmonic waveguides,as a competitive candidate,have been widely studied in rapid developing photonic integrated circuits(PICs)and optical interconnection fields.However,crosstalk between plasmonic waveguides is a critical issue that has to be considered in practice.Actually,crosstalk dominates the ultimate integration density of the planar photonic circuits.This paper reviews the recent research work on evaluation methods and crosstalk suppression approaches of plasmonic waveguides.Three crosstalk evaluation methods based on comparison of specific parameters of waveguides have been summarized.Furthermore,four specific approaches to reduce crosstalk have been illustrated as two categories according to their impacts on waveguide performances and the whole circuit.One means of crosstalk suppression is changing the placement of waveguides,which could maintain the transmission characteristics of the original waveguide.The other means is inserting medium,which has the advantage of occupying smaller space compared to the first method.Consequently,to suppress crosstalk between plasmonic waveguides,one should choose suitable approach.

Interlayer sensitized van der Waals heterojunction photodetector with enhanced performance

Although photodetection based on two-dimensional(2D)van der Waals(vdWs)P-N heterojunction has attracted extensive attention recently,their low responsivity(R)due to the lack of carrier gain mechanism in reverse bias or zero bias operation hinders their applications in advanced photodetection area.Here,a black phosphorus/rhodamine 6G/molybdenum disulfide(BP/R6G/MoS_(2))photodiode with high responsivity at reverse bias or zero bias has been achieved by using interfacial charge transfer of R6G molecules assembled between heterojunction layers.The formed vdWs interface achieves high performance photoresponse by efficiently separating the additional photogenerated electrons and holes generated by R6G molecules.The devices sensitized by the dye molecule R6G exhibit enhanced photodetection performance without sacrificing the photoresponse speed.Among them,the R increased by 14.8-20.4 times,and the specific detectivity(D^(*))increased by 24.9-34.4 times.The strategy based on interlayer assembly of dye molecules proposed here may pave a new way for realizing high-performance photodetection based on 2D vdWs heterojunctions with high responsivity and fast response speed.

Targeted Fully Homomorphic Encryption Based on a Double Decryption Algorithm for Polynomials

Several public-key encryption schemes used to solve the problem of ciphertext data processing on the fly are discussed. A new targeted fully homomorphic encryption scheme based on the discrete logarithm problem is presented. Public-key encryption cryptosystems are classified to examine homomorphic encryption. Without employing techniques proposed by Gentry such as somewhat homomorphic and bootstrapping techniques, or relinearization technique proposed by Brakerski et al., a new method called ＂Double Decryption Algorithm＂ is employed in our cryptography to satisfy a fully or targeted fully homomorphic property. Inspired by EIGamal and BGN cryptography, we obtain the desired fully homomorphic property by selecting a new group and adding an extra component to the ciphertext. Proof of semantic security is also demonstrated.

UCBIS:An improved consortium blockchain information system based on UBCCSP

Blockchain technologies have been applied in many areas,from economics,the internet of things to the industrial internet.In order to solve the issue that the Hyperledger Fabric does not currently support Chinese Commercial Cryptographic(CCC)algorithms,we extended the Blockchain Cryptographic Service Provider(BCCSP)module in the Hyperledger Fabric by upgrading the original BCCSP module to support the CCC algorithms SM2 and SM3.Furthermore,we designed a transaction process by using UBCCSP(Upgraded BCCSP),and a new smart contract also has been presented.After that,an improved consortium blockchain information system based on UBCCSP named UCBIS(Consortium Blockchain Information System based on UBCCSP)is proposed.In the Hyperledger Fabric transaction process,the identity information and transaction data are protected by the SM2 and SM3 algorithms,moreover,SM3 is also used in the construction process of smart contracts.Our smart contracts reduce the total data amount and improve query efficiency.Finally,the information query system based on UBCCSP is implemented.After being tested and analyzed,the average time for every query is only 31.162 ms in the blockchain system,which has better performance and higher query efficiency.

Single-shot terahertz polarization detection based on terahertz time-domain spectroscopy

This paper presents a novel design for single-shot terahertz polarization detection based on terahertz time-domain spectroscopy(THz-TDS).Its validity has been confirmed by comparing its detection results with those of the THz common-path spectral interferometer through two separate measurements for the orthogonal components.Our results also show that its detection signal-to-noise ratios(SNRs)are obviously superior to those of the 45°optical bias THz-TDS by electro-optical sampling due to its operation on common-path spectral interference rather than the polarization-sensitive intensity modulation.The setup works without need of any optical scan,which does not only save time,but also efficiently avoids the disturbances from the fluctuations of the system and environment.Its single-shot mode allows it to work well for the applications with poor or no repeatability.