期刊文献+
共找到202,416篇文章
< 1 2 250 >
每页显示 20 50 100
Impact of Shockwave on Condensation Efficiency of Supersonic Nozzle during Natural Gas Purification
1
作者 Lei Zhao Lihui Ma +3 位作者 Junwen Chen Pan Zhang Jiang Bian Dong Sun 《Energy Engineering》 2026年第2期314-328,共15页
Shock waves in the nozzle during supersonic separation under different conditions can disrupt the flow field’s thermodynamic equilibrium.While it contributes to the recovery of pressure energy,it also leads to the di... Shock waves in the nozzle during supersonic separation under different conditions can disrupt the flow field’s thermodynamic equilibrium.While it contributes to the recovery of pressure energy,it also leads to the dissipation of mechanical energy.This study aimed to investigate the effects of changes in back pressure on the shock wave position and its subsequent impact on the refrigeration performance of nozzles.A mathematical model for the supersonic gas in a nozzle was established and evaluated via experiments.The results show that when the back pressure is less than 0.2 MPa,no shock wave is generated in the nozzle,and high refrigeration and liquefaction efficiency can be ensured while effective pressure recovery is achieved.When the back pressure(pb)is increased from 0.3 to 0.6 MPa,the refrigeration efficiency of the nozzle decreases,and the shock wave position(x shock)is advanced from 157 to 118 mm.The maximum Mach number(Ma)that can be reached by the fluid in the nozzle is reduced from 1.97 to 1.27.When the back pressure is increased from 0.2 to 0.6 MPa,the minimum temperature is increased by 55.18 K.When the back pressure is greater than 0.3 MPa,the Mach number upstream of the shock wave is reduced from 1.97 to 1.27,the shock wave intensity is weakened,and the thickness of the boundary layer separation caused by the shock wave is also decreased accordingly.Therefore,to ensure refrigeration efficiency,measures should be taken to control the back pressure within a reasonable range. 展开更多
关键词 Supersonic nozzle SHOCKWAVE boundary layer energy conversion refrigeration efficiency
在线阅读 下载PDF
Design and optimization of a high-efficiency current-biased reverse load modulated power amplifier with impedance and performance constraints
2
作者 Zhongpeng NI Heng ZHANG +4 位作者 Jing XIA Wence ZHANG Wa KONG Chao YU Xiaowei ZHU 《ENGINEERING Information Technology & Electronic Engineering》 2026年第1期71-79,共9页
We propose an optimization method based on evolutionary computation for the design of broadband high-efficiency current-biased reverse load-modulation power amplifiers(CB-RLM PAs).First,given the reverse load-modulati... We propose an optimization method based on evolutionary computation for the design of broadband high-efficiency current-biased reverse load-modulation power amplifiers(CB-RLM PAs).First,given the reverse load-modulation characteristics of CB-RLM PAs,a comprehensive objective function is proposed that combines multi-state impedance trajectory constraints with in-band performance deviations.For the saturation and 6 dB power back-off(PBO)states,approximately optimal impedance regions on the Smith chart are derived using impedance constraint circles based on load-pull simulations.These regions are used together with in-band performance deviations(e.g.,saturated efficiency,6 dB PBO efficiency,and saturated output power)for matching network optimization and design.Second,a multi-objective evolutionary algorithm based on decomposition with adaptive weights,neighborhood,and global replacement is integrated with harmonic balance simulations to optimize design parameters and evaluate performance.Finally,to validate the proposed method,a broadband CB-RLM PA operating from 0.6 to 1.8 GHz is designed and fabricated.Measurement results show that the efficiencies at saturation,6 dB PBO,and 8 dB PBO all exceed 43.6%,with saturated output power being maintained at 40.9–41.5 dBm,which confirms the feasibility and effectiveness of the proposed broadband high-efficiency CB-RLM PA optimization and design approach. 展开更多
关键词 Current-biased reverse load-modulation Broadband High efficiency Power amplifier Optimization
在线阅读 下载PDF
Efficiency and regional differences of forest restoration across China's Upper Yangtze River Basin
3
作者 Zhiwei Lei Jia Zhou +2 位作者 Yike Li Yingnan Zhao Tao Lu 《Journal of Forestry Research》 2026年第1期42-59,共18页
Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost input... Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost inputs.This gap can lead to increased uncertainties in restoration planning.Here we investigated forest dynamics in China's Upper Yangtze River Basin(UYRB)using kernel Normalized Difference Vegetation Index(kNDVI),Leaf Area Index(LAI),Gross Primary Productivity(GPP),Ku-band Vegetation Optical Depth(Ku-VOD)time series and climate data from1982 to 2020.Subsequently,we employed a residual trend analysis integrating temporal effects to determine the relative contributions of climate change and human activities to forest dynamics before and after the implementation of forest restoration engineering in 1998.Additionally,we developed an Afforestation Efficiency Index(AEI)to quantitatively assess the cost efficiency of afforestation projects.Results indicated that forest in the UYRB showed sustained increases during 1982-2020,with most areas experiencing greater growth after 1998 than before.Temporal effects of climatic factors influenced over 42.7%of the forest,and incorporating time-lag and cumulative effects enhanced climate-based explanations of forest variations by 1.61-24.73%.Human activities emerged as the dominant driver of forest dynamics post 1998,whereas climate variables predominated before this period.The cost-effectiveness of forest restoration projects in the UYRB typically ranges from moderate to high,with higher success predominantly observed in the northeastern and eastern counties,while the central,western,and northwestern counties mainly showed relatively low efficiency.These findings stress the need for assessing forest restoration outcomes from both ecological and cost perspectives,and can offer valuable insights for optimizing the layout of forest restoration initiatives in the UYRB. 展开更多
关键词 Forest restoration Driving force analysis Temporal effects Afforestation efficiency
在线阅读 下载PDF
Multi-objective ANN-driven genetic algorithm optimization of energy efficiency measures in an NZEB multi-family house building in Greece
4
《建筑节能(中英文)》 2026年第2期62-62,共1页
The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measu... The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measures in a multi-family house building in Greece.The energy efficiency measures include different heating/cooling systems(such as low-temperature and high-temperature heat pumps,natural gas boilers,split units),building envelope components for floor,walls,roof and windows of variable heat transfer coefficients,the installation of solar thermal collectors and PVs.The calculations of the building loads and investment and operating and maintenance costs of the measures are based on the methodology defined in Directive 2010/31/EU,while economic assumptions are based on EN 15459-1 standard.Typically,multi-objective optimization of energy efficiency measures often requires the simulation of very large numbers of cases involving numerous possible combinations,resulting in intense computational load.The results of the study indicate that ANN-driven GA methods can be used as an alternative,valuable tool for reliably predicting the optimal measures which minimize primary energy consumption and life cycle cost of the building with greatly reduced computational requirements.Through GA methods,the computational time needed for obtaining the optimal solutions is reduced by 96.4%-96.8%. 展开更多
关键词 energy efficiency measures gas boilerssplit units building envelope components energy efficiency economic performance artificial neural network ann driven multi objective optimization economic performance optimization ANN driven GA methods
在线阅读 下载PDF
Asymmetric Side‑Group Engineering of Nonfused Ring Electron Acceptors for High‑Efficiency Thick‑Film Organic Solar Cells
5
作者 Dawei Li Nan Wei +11 位作者 Ya‑Nan Chen Xiaodong Wang Xu Han Ziqing Bian Xinyuan Zhang Zhe Zhang Wenkai Zhang Xinjun Xu Cuihong Li Yahui Liu Hao Lu Zhishan Bo 《Nano-Micro Letters》 2026年第3期227-239,共13页
A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamin... A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs. 展开更多
关键词 Organic solar cells Nonfused ring electron acceptors ASYMMETRIC Power conversion efficiency
在线阅读 下载PDF
Energy Efficiency and Total Mission Completion Time Tradeoff in Multiple UAVs-Mounted IRS-Assisted Data Collection System
6
作者 Hong Zhao Hongbin Chen +2 位作者 Zhihui Guo Ling Zhan Shichao Li 《Computers, Materials & Continua》 2026年第2期1849-1873,共25页
UAV-mounted intelligent reflecting surface(IRS)helps address the line-of-sight(LoS)blockage between sensor nodes(SNs)and the fusion center(FC)in Internet of Things(IoT).This paper considers an IoT assisted by multiple... UAV-mounted intelligent reflecting surface(IRS)helps address the line-of-sight(LoS)blockage between sensor nodes(SNs)and the fusion center(FC)in Internet of Things(IoT).This paper considers an IoT assisted by multiple UAVs-mounted IRS(U-IRS),where the data from ground SNs are transmitted to the FC.In practice,energy efficiency(EE)and mission completion time are crucial metrics for evaluating system performance and operational costs.Recognizing their importance during data collection,we formulate a multi-objective optimization problem to maximize EE and minimize total mission completion time simultaneously.To characterize this tradeoff while considering optimization objective consistency,we construct an optimization problem that minimizes the weighted sum of the total mission completion time and the reciprocal of EE.Due to the non-convex nature of the formulated problem,obtaining optimal solutions is generally challenging.To tackle this issue,we decompose it into three subproblems:UAV-SN association,number of reflecting elements allocation,andUAVtrajectory optimization.An iterative algorithmcombining genetic algorithm,CS-BJ algorithm,and successive convex approximation technique is proposed to solve these sub-problems.Simulation results demonstrate that when the transmitted data amount is 10 and 30Mbits,compared to the static collection benchmark(the UAV hovers directly above each SN),the EE of the proposed method improves by more than 10.4% and 5.2%,while the total mission completion time is reduced by more than 5.4% and 3.3%,respectively. 展开更多
关键词 Unmanned aerial vehicle intelligent reflecting surface energy efficiency totalmission completion time optimization
在线阅读 下载PDF
Balancing energy efficiency and avian conservation:divergent nest-site selection responses of Barn Swallows and Red-rumped Swallows to attached sunspaces in cold rural landscapes
7
作者 Zheng Han Kaiyan Li +8 位作者 Xiaoxiao Wang Xi Yang Piotr Tryjanowski Frederic Jiguet Letao Huang Houjun Wang Jingshu Zhang Ziqi liu Haitao Wang 《Avian Research》 2026年第1期108-115,共8页
Human-modified landscapes serve as ecological filters,determining species distributions and persistence.Energy-efficient technologies,while crucial for climate change mitigation,represent novel filters whose impacts o... Human-modified landscapes serve as ecological filters,determining species distributions and persistence.Energy-efficient technologies,while crucial for climate change mitigation,represent novel filters whose impacts on synanthropic biodiversity are poorly understood.We investigated how attached sunspaces,a widely adopted energy-saving technology in rural China,filter the distribution of two ecologically important aerial insectivores,the Barn Swallow(Hirundo rustica)and Red-rumped Swallow(Cecropis daurica).We surveyed 106 villages during the 2024 and 2025 breeding seasons and recorded a total of 2323 nests(612 Barn Swallow,1711 Red-rumped Swallow).Using Generalized Linear Models,we assessed their responses to building characteristics,landscape composition and the prevalence of sunspaces.Barn Swallow nests preferred perches at the base and single attachment faces,while Red-rumped Swallow nests favored multiple attachment faces and avoided long shelters.The proportion of buildings with sunspaces acted as a strong positive filter for Barn Swallow nest abundance(+24%)but as a significant negative filter for Red-rumped Swallow(-51%).Other landscape variables(e.g.,human population density,NDVI,Human Footprint Index)were not significant.This study demonstrates that specific architectural innovations can act as powerful ecological filters,leading to divergent distributional outcomes for sympatric species reliant on anthropogenic structures.Our findings reveal a critical trade-off in sustainable development:energy efficiency gains may inadvertently reduce habitat suitability for certain species.To reconcile climate and biodiversity goals in rural landscapes,we advocate integrating species-specific habitat requirements into building design.We propose actionable modifications to sunspaces to support swallows without compromising energy savings.These principles provide a template for mitigating the distributional impacts of green infrastructure globally. 展开更多
关键词 Barn Swallows Energy efficiency Multi-scale analysis Nest-site selection Red-rumped Swallows Rural landscape Sunspace
在线阅读 下载PDF
Superconducting nanowire single photon detector with efficiency over 90% at 2μm wavelength
8
作者 Zhen Wan Jia Huang +6 位作者 Guangzhao Xu Yu Ding Xiaoyu Liu Yiming Pan Hongxin Xu Hao Li Lixing You 《Chinese Physics B》 2026年第1期306-312,共7页
We here report a high system detection efficiency(SDE)superconducting single-photon detector(SSPD)at 2μm wavelength.The device integrates a SiO_(2)/Ta_(2)O_(5)distributed Bragg reflector(DBR)and a sandwich-structured... We here report a high system detection efficiency(SDE)superconducting single-photon detector(SSPD)at 2μm wavelength.The device integrates a SiO_(2)/Ta_(2)O_(5)distributed Bragg reflector(DBR)and a sandwich-structured double-layer NbN nanowire to enhance the optical absorption efficiency.A cold development technique is implemented to optimize the superconducting nanowires with sub-40-nm linewidths,thus enhancing the intrinsic detection efficiency(IDE).The fabricated SSPD shows an SDE exceeding 90% at 2μm wavelength.Moreover,the detector allows an operational working temperature of 2.2 K provided by a compact GM cryo-cooler.This detector delivers excellent performance at the 2μm wavelength,and its optimized structural design implies promising potential for extending detection toward longer infrared bands.It thus holds value for advancing high-sensitivity quantum technologies,mid-infrared optical communications,and dark matter detection research. 展开更多
关键词 superconducting single-photon detectors(SSPDs) system detection efficiency near infrared
原文传递
Energy Efficiency Maximization for CR-NOMA Based Smart Grid Communication Network
9
作者 Mubashar Sarfraz Sheraz Alam +1 位作者 Sajjad A.Ghauri Asad Mahmood 《China Communications》 2026年第2期244-259,共16页
Managing massive data flows effectively and resolving spectrum shortages are two challenges that smart grid communication networks(SGCN)must overcome.To address these problems,we provide a combined optimization approa... Managing massive data flows effectively and resolving spectrum shortages are two challenges that smart grid communication networks(SGCN)must overcome.To address these problems,we provide a combined optimization approach that makes use of cognitive radio(CR)and non-orthogonal multiple access(NOMA)technologies.Our work focuses on using user pairing(UP)and power allocation(PA)techniques to maximize energy efficiency(EE)in SGCN,particularly within neighbourhood area networks(NANs).We develop a joint optimization problem that takes into account the real-world limitations of a CR-NOMA setting.This problem is NP-hard,nonlinear,and nonconvex by nature.To address the computational complexity of the problem,we use the block coordinate descent(BCD)method,which breaks the problem into UP and PA subproblems.Initially,we proposed the zebra-optimization user pairing(ZOUP)algorithm to tackle the UP problem,which outperforms both orthogonal multiple access(OMA)and non-optimized NOMA(UPWO)by 78.8%and13.6%,respectively,at a SNR of 15 dB.Based on the ZOUP pairs,we subsequently proposed the PA approach,i.e.,ZOUPPA,which significantly outperforms UPWO and ZOUP by 53.2%and 25.4%,respectively,at an SNR of 15 dB.A detailed analysis of key parameters,including varying SNRs,power allocation constants,path loss exponents,user density,channel availability,and coverage radius,underscores the superiority of our approach.By facilitating the effective use of communication resources in SGCN,our research opens the door to more intelligent and energy-efficient grid systems.Our work tackles important issues in SGCN and lays the groundwork for future developments in smart grid communication technologies by combining modern optimization approaches with CR-NOMA. 展开更多
关键词 cognitive radio energy efficiency nonorthogonal multiple access smart grid communications zebra optimization algorithm
在线阅读 下载PDF
Optimizing nitrogen application and planting density improves yield and resource use efficiency via regulating canopy light and nitrogen distribution in rice
10
作者 Zichen Liu Liyan Shang +8 位作者 Shuaijun Dai Jiayu Ye Tian Sheng Jun Deng Ke Liu Shah Fahad XiaohaiTian Yunbo Zhang Liying Huang 《Journal of Integrative Agriculture》 2026年第1期81-91,共11页
Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting d... Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting density and N rate,and their relationships with grain yield,radiation use efficiency(RUE),and N use efficiency for grain production(NUEg)in rice.A two-year field experiment was conducted with two hybrid varieties under three N levels,0 kg ha^(-1)(N1),90 kg ha^(-1)(N2)and 180 kg ha^(-1)(N3),and two planting densities,22.2 hills m-2(D1)and 33.3 hills m^(-2)(D2).Results showed 3.4%higher yield and 4.4%higher NUEg under N2D2 compared with N3D1.The extinction coefficient for N(K_(N))and light(K_(L))and their ratio(K_(N)/K_(L))at heading stage were significantly influenced by N rate,planting density,and their interaction.K_(N)decreased with the increase of N input or planting density.Compared to N1,K_(N)decreased by 43.5 and 58.8%under N2 and N3,respectively,while K_(N)under D2 decreased by 16.0%compared to D1.Higher K_(L)and K_(N)/K_(L)values occurred under low N rates,with opposite trends under high N rates.Increased planting density led to decreased K_(L)and K_(N)/K_(L)values.N2D2 demonstrated higher K_(L)and K_(N),and thus comparable K_(N)/K_(L),compared to N3D1.Correlation analysis revealed K_(L)negatively correlated with RUE,while K_(N)and K_(N)/K_(L)positively correlated with NUEg.These findings indicate that increasing planting density under reduced N input could maintain rice yield while enhancing resource use efficiency through regulation of canopy light and N distribution. 展开更多
关键词 canopy light and N distribution nitrogen input planting density high yield and high efficiency hybrid rice
在线阅读 下载PDF
Examining the Nonlinear Effects of Urban Population Polycentricity on Carbon Emissions Efficiency Using a Gradient Boosting Decision Tree Model:Evidence from 295 Chinese Cities
11
作者 WANG Cheng YANG Xingzhu 《Chinese Geographical Science》 2026年第2期222-238,共17页
Transforming urban spatial structures to promote green and low-carbon development is an effective strategy.Although prior studies have examined the impact of urban polycentricity on carbon emissions and economic devel... Transforming urban spatial structures to promote green and low-carbon development is an effective strategy.Although prior studies have examined the impact of urban polycentricity on carbon emissions and economic development,research on its role in the synergistic relationship between these factors regarding carbon emission efficiency is limited.Furthermore,existing literature often overlooks nonlinear effects and interactions with other urban variables.This paper analyzed data from 295 Chinese cities in 2020,calculating urban population polycentricity,population dispersion indices,and carbon emission efficiency.Utilizing local spatial autocorrelation tools,we reveal interactions among urban population polycentricity,dispersion,carbon emissions,and carbon emission efficiency.We then employ a gradient boosting decision tree model(GBDT)to explore nonlinear and synergistic effects of polycentric urbanization.Key findings include:1)polycentric urbanization in Chinese cities exhibits significant spatial differentiation characteristics.The Polycentricity index is relatively high in economically developed eastern coastal regions with an overall low level,carbon emissions are concentrated in industrialized north-central cities and some Yangtze River Delta hubs,and carbon emission efficiency is the highest in the Yangtze River Delta while relatively low in Northeast China;there are significant spatially heterogeneous interaction characteristics among population polycentricity,population dispersion,carbon emissions,and carbon emission efficiency.2)Urban population polycentricity contributes 9.42%to total carbon emissions and 6.24%to carbon emission efficiency.3)The polycentricity index has a nonlinear impact on carbon emissions and carbon emission efficiency:no significant effect when below 0.50 or above 0.55,increased carbon emissions in 0.50-0.53,and reduced carbon emissions with improved efficiency in 0.53-0.55.4)The polycentricity index has an interaction effect with other variables;specifically,when the polycentricity index is between 0.53 and 0.55,its interaction with urban gross domestic product(GDP),urban population,urban built-up area,green coverage rate in built-up areas,urban technological expenditure,and the proportion of the output value of the secondary industry will reduce carbon emissions and improve carbon emission efficiency.These findings enhance the understanding of urban spatial structures and carbon emissions,providing valuable insights for policymakers in developing green and low-carbon strategies. 展开更多
关键词 urban polycentricity carbon emission efficiency gradient boosting decision tree(GBDT) nonlinear threshold effects Chinese cities
在线阅读 下载PDF
From Efficiency to Resilience New logic of China-ASEAN supply chain cooperation
12
作者 Luo Shengrong Li Ningxin 《China Report ASEAN》 2026年第2期22-25,共4页
The China-ASEAN Free Trade Area(CAFTA)3.0Upgrade Protocol added a section on“Supply Chain Connectivity,”which emphasizes that all parties recognize the lessons learned from the COVID-19 pandemic and cooperate to enh... The China-ASEAN Free Trade Area(CAFTA)3.0Upgrade Protocol added a section on“Supply Chain Connectivity,”which emphasizes that all parties recognize the lessons learned from the COVID-19 pandemic and cooperate to enhance the resilience of the regional supply chain.This is an inevitable trend amid the current accelerated restructuring of the global supply chain,the complex and severe international economic and trade situation,and the impact on the regional industrial chain.It also represents a fundamental shift and consensus on the logic of supply chain cooperation between China and ASEAN countries—a transformation from“Efficiency First”to“Resilience First.” 展开更多
关键词 efficiency enhance resilience supply chainthe supply chain connectivity fundamental shift RESILIENCE China ASEAN supply chain cooperation supply chainthis
在线阅读 下载PDF
A deep-junction single-photon detector with field polysilicon gate structure for increased photon detection efficiency and reduced dark count noise
13
作者 Zhentao Ni Dajing Bian +2 位作者 Haoxiang Jiang Xiaoming Huang Yue Xu 《Journal of Semiconductors》 2026年第1期65-71,共7页
A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep aval... A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep avalanche multiplication region for near-infrared(NIR)sensitivity enhancement.By optimizing the device size and electric field of the guard ring,the fill factor(FF)is significantly improved,further increasing photon detection efficiency(PDE).To solve the dark noise caused by the increasing active diameter,a field polysilicon gate structure connected to the p+anode was investigated,effectively suppressing dark count noise by 76.6%.It is experimentally shown that when the active diameter increases from 5 to 10μm,the FF is significantly improved from 20.7%to 39.1%,and thus the peak PDE also rises from 13.3%to 25.8%.At an excess bias voltage of 5 V,a NIR photon detection probability(PDP)of 6.8%at 905 nm,a dark count rate(DCR)of 2.12 cps/μm^(2),an afterpulsing probability(AP)of 1.2%,and a timing jitter of 216 ps are achieved,demonstrating excellent single photon detection performance. 展开更多
关键词 single-photon avalanche diode(SPAD) fill factor(FF) photon detection efficiency(PDE) dark count rate(DCR)
在线阅读 下载PDF
Energy Efficiency Optimization for Active Reconfigurable Intelligent Surface Assisted Multi-Antenna Jamming Systems 被引量:1
14
作者 Qin Hao Zhu Jia +5 位作者 Zou Yulong Li Yizhi Lou Yulei Zhang Afei Hui Hao Qin Changjian 《China Communications》 2025年第6期44-56,共13页
In this paper,we examine an illegal wireless communication network consisting of an illegal user receiving illegal signals from an illegal station and propose an active reconfigurable intelligent surface(ARIS)-assiste... In this paper,we examine an illegal wireless communication network consisting of an illegal user receiving illegal signals from an illegal station and propose an active reconfigurable intelligent surface(ARIS)-assisted multi-antenna jamming(MAJ)scheme denoted by ARIS-MAJ to interfere with the illegal signal transmission.In order to strike a balance between the jamming performance and the energy consumption,we consider a so-called jamming energy efficiency(JEE)which is defined as the ratio of achievable rate reduced by the jamming system to the corresponding power consumption.We formulate an optimization problem to maximize the JEE for the proposed ARIS-MAJ scheme by jointly optimizing the jammer’s beamforming vector and ARIS’s reflecting coefficients under the constraint that the jamming power received at the illegal user is lower than the illegal user’s detection threshold.To address the non-convex optimization problem,we propose the Dinkelbach-based alternating optimization(AO)algorithm by applying the semidefinite relaxation(SDR)algorithm with Gaussian randomization method.Numerical results validate that the proposed ARIS-MAJ scheme outperforms the passive reconfigurable intelligent surface(PRIS)-assisted multi-antenna jamming(PRIS-MAJ)scheme and the conventional multiantenna jamming scheme without RIS(NRIS-MAJ)in terms of the JEE. 展开更多
关键词 active reconfigurable intelligent surface(ARIS) beamforming optimization jamming energy efficiency(JEE)
在线阅读 下载PDF
Novel Giant Acceptors Drive Eco-Friendly Organic Solar Cells Past 20%Efficiency
15
《Bulletin of the Chinese Academy of Sciences》 2025年第4期257-257,共1页
A research team led by Dr.GE Ziyi from the Ningbo Institute of Materials Technology and Engineering(NIMTE)of the Chinese Academy of Sciences has developed novel giant acceptors with an oxygenated linker,enabling the c... A research team led by Dr.GE Ziyi from the Ningbo Institute of Materials Technology and Engineering(NIMTE)of the Chinese Academy of Sciences has developed novel giant acceptors with an oxygenated linker,enabling the creation of highly efficient non-halogen-processed organic solar cells(OSCs),with a power conversion efficiency(PCE)up to 20.02%. 展开更多
关键词 oxygenated linkerenabling non halogen processed giant acceptors oxygenated linker eco friendly organic solar cells power conversion efficiency
在线阅读 下载PDF
From seed to whole plant:An innovative visual marker system to enhance selection efficiency in soybean genome editing
16
作者 Tingwei Yan Xueyan Qian +5 位作者 Hong Pan Jiarui Han Qi Wang Chang Liu Dongquan Guo Xiangguo Liu 《Journal of Integrative Agriculture》 2026年第2期820-823,共4页
Emerging and powerful genome editing tools,particularly CRISPR/Cas9,are facilitating functional genomics research and accelerating crop improvement(Jiang et al.2021;Cao et al.2023;Chen C et al.2023;Liu et al.2023a).Ho... Emerging and powerful genome editing tools,particularly CRISPR/Cas9,are facilitating functional genomics research and accelerating crop improvement(Jiang et al.2021;Cao et al.2023;Chen C et al.2023;Liu et al.2023a).However,the detection and screening of transgenic lines remain major bottlenecks,being time-consuming,labor-intensive,and inefficient during transformation and subsequent mutation identification.A simple and efficient visual marker system plays a critical role in addressing these challenges.Recent studies demonstrated that the GmW1 and RUBY reporter systems were used to obtain visual transgenic soybean(Glycine max) plants(Chen L et al.2023;Chen et al.2024). 展开更多
关键词 accelerating crop improvement jiang mutation identificationa enhance selection efficiency SEED functional genomics research detection screening transgenic lines genome editing toolsparticularly innovative visual marker system
在线阅读 下载PDF
The Impact of the Digital Economy on Urban Energy-Environment Efficiency
17
作者 Menghao Tian 《Proceedings of Business and Economic Studies》 2025年第2期185-190,共6页
This study takes the panel data of 278 prefecture-level cities in China from 2011 to 2022 as samples,constructs a super-efficiency SBM model to measure urban energy-environment efficiency,uses the entropy method to sy... This study takes the panel data of 278 prefecture-level cities in China from 2011 to 2022 as samples,constructs a super-efficiency SBM model to measure urban energy-environment efficiency,uses the entropy method to synthesize the digital economy composite index,and introduces the green innovation index as a mediating variable.Breaking through the traditional analysis framework in the empirical method:Firstly,through the fixed-effects model and mediating-effect test,it reveals the direct impact of the digital economy on energy-environment efficiency and the transmission path of green innovation.Secondly,it divides the eastern,central,and western regions and low-carbon pilot cities for heterogeneity tests to identify the moderating effect of policy intervention.Thirdly,it strengthens the robustness of the conclusions by replacing the super-efficiency CCR model,shortening the sample period,and performing winsorization.The study finds that the digital economy significantly improves energy-environment efficiency through green technology innovation.These conclusions provide an empirical basis for optimizing the layout of digital infrastructure and improving the regional collaborative emission-reduction mechanism. 展开更多
关键词 Digital economy Energy-environment efficiency Super-efficiency SBM Green development
在线阅读 下载PDF
Social Governance Paths to Improve the Efficiency of Rural Collective Economic Audit
18
作者 Yan LI Qin LIU Dongwen SUN 《Asian Agricultural Research》 2025年第2期17-20,26,共5页
In view of the series of problems found in the rural collective economic audit in Zhangdian District of Zibo City in the past five years,this study used empirical research methods to deeply analyze the current situati... In view of the series of problems found in the rural collective economic audit in Zhangdian District of Zibo City in the past five years,this study used empirical research methods to deeply analyze the current situation and existing problems of the village collective audit work.On this basis,typical cases were selected for in-depth analysis,the effects of different audit modes were compared,and the reliable paths to improve the efficiency of village collective audit were studied and considered.The results show that the social governance strategy plays a positive role in improving the efficiency of village collective audit.This study is expected to provide a reference for the improvement of village collective audit efficiency,and is of great significance to improve the village collective financial management and promote the improvement of the rural governance system. 展开更多
关键词 Rural collective economy Audit efficiency Social governance PATHS
在线阅读 下载PDF
Analysis of Influencing Factors of Platform Economy on the Allocation Efficiency of Labor Resources
19
作者 Yifan Wang 《Proceedings of Business and Economic Studies》 2025年第4期245-251,共7页
Against the backdrop of the rapid development of digitalization today,the platform economy,as an emerging economic form,is profoundly changing the operation mode and resource allocation methods of the labor market.The... Against the backdrop of the rapid development of digitalization today,the platform economy,as an emerging economic form,is profoundly changing the operation mode and resource allocation methods of the labor market.The efficiency of labor resource allocation is an important indicator to measure the vitality and potential of economic development in a country or region.It is not only related to the welfare level of workers but also directly affects the productivity level and development quality of the entire society.With the help of modern information technology means such as Internet technology,big data algorithms,and mobile communication devices,the platform economy closely connects originally scattered individual workers with employers,building a large and complex networked trading platform.Based on this,this paper focuses on the impact and role of the platform economy on the efficiency of labor resource allocation,aiming to stabilize the efficient operation of the labor market. 展开更多
关键词 Platform economy Labor resources Allocation efficiency Influencing factors
在线阅读 下载PDF
Research on Governance Mechanisms and Supply Chain Efficiency Optimization of the Smart Home Enterprise Ecological Collaboration Platform
20
作者 Wen Peng 《Proceedings of Business and Economic Studies》 2025年第4期1-6,共6页
This paper focuses on the core challenges of the smart home enterprise ecological collaboration platform,and deeply discusses the absence of a governance mechanism and the inefficiency of the supply chain.The purpose ... This paper focuses on the core challenges of the smart home enterprise ecological collaboration platform,and deeply discusses the absence of a governance mechanism and the inefficiency of the supply chain.The purpose is to improve the overall efficiency by constructing an effective collaborative governance framework and optimizing the supply chain process.It is found that the implementation of multi-agent dynamic contract governance,the construction of an open data sharing middle platform,the introduction of AI-driven elastic supply chain planning,and the establishment of a distributed cloud manufacturing network are the key paths.From the research conclusion,these measures can significantly improve the transparency of cross-agent collaboration,break the data barriers,and achieve the accurate matching of supply and demand,and finally promote the ecological collaboration efficiency of the smart home industry to achieve a substantial leap. 展开更多
关键词 Smart home ecological collaboration platform Governance mechanism Supply chain efficiency Optimization research
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部