期刊文献+
共找到169,467篇文章
< 1 2 250 >
每页显示 20 50 100
Dual‑Donor‑Induced Crystallinity Modulation Enables 19.23% Efficiency Organic Solar Cells
1
作者 Anhai Liang Yuqing Sun +9 位作者 Sein Chung Jiyeong Shin Kangbo Sun Chaofeng Zhu Jingjing Zhao Zhenmin Zhao Yufei Zhong Guangye Zhang Kilwon Cho Zhipeng Kan 《Nano-Micro Letters》 SCIE EI CAS 2025年第3期376-388,共13页
Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challengin... Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challenging.Herein, wide bandgap polymer donor PTzBI-dF is demonstrated as an effectivemodulator for enhancing the crystallinity of the bulk heterojunction active layerscomposed of D18 derivatives blended with Y6, leading to dense and orderedmolecular packings, and thus, improves photoluminescence quenching properties.As a result, the photovoltaic devices exhibit reduced trap-assisted charge recombinationlosses, achieving an optimized power conversion efficiency of over 19%.Besides the efficiency enhancement, the devices comprised of PTzBI-dF as athird component simultaneously attain decreased current leakage, improved chargecarrier mobilities, and suppressed bimolecular charge recombination, leading toreduced energy losses. The advanced crystalline structures induced by PTzBI-dFand its characteristics, such as well-aligned energy level, and complementaryabsorption spectra, are ascribed to the promising performance improvements.Our findings suggest that donor phase engineering is a feasible approach to tuning the molecular packings in the active layer, providingguidelines for designing effective morphology modulators for high-performance organic solar cells. 展开更多
关键词 Trap-assisted charge recombination PHOTOLUMINESCENCE MISCIBILITY Current leakage Power conversion efficiency
下载PDF
Two-Stage High-Efficiency Encryption Key Update Scheme for LoRaWAN Based IoT Environment 被引量:1
2
作者 Kun-Lin Tsai Li-Woei Chen +1 位作者 Fang-Yie Leu Chuan-Tian Wu 《Computers, Materials & Continua》 SCIE EI 2022年第10期547-562,共16页
Secure data communication is an essential requirement for an Internet of Things(IoT)system.Especially in Industrial Internet of Things(IIoT)and Internet of Medical Things(IoMT)systems,when important data are hacked,it... Secure data communication is an essential requirement for an Internet of Things(IoT)system.Especially in Industrial Internet of Things(IIoT)and Internet of Medical Things(IoMT)systems,when important data are hacked,it may induce property loss or life hazard.Even though many IoTrelated communication protocols are equipped with secure policies,they still have some security weaknesses in their IoT systems.LoRaWAN is one of the low power wide-area network protocols,and it adopts Advanced Encryption Standard(AES)to provide message integrity and confidentiality.However,LoRaWAN’s encryption key update scheme can be further improved.In this paper,a Two-stage High-efficiency LoRaWAN encryption key Update Scheme(THUS for short)is proposed to update LoRaWAN’s root keys and session keys in a secure and efficient way.The THUS consists of two stages,i.e.,the Root Key Update(RKU)stage and the Session Key Update(SKU)stage,and with different update frequencies,the RKU and SKU provide higher security level than the normal LoRaWAN specification does.A modified AES encryption/decryption process is also utilized in the THUS for enhancing the security of the THUS.The security analyses demonstrate that the THUS not only protects important parameter during key update stages,but also satisfies confidentiality,integrity,and mutual authentication.Moreover,The THUS can further resist replay and eavesdropping attacks. 展开更多
关键词 Key update AES LoRaWAN IoT security high efficiency
下载PDF
Multi-objective Optimization of a Two-Stage Helical Gearbox to Improve Efficiency and Reduce Height
3
作者 Tran Quoc Hung Truong Thi Thu Huong 《Journal of Environmental Science and Engineering(B)》 2023年第5期236-247,共12页
The goal of this research is to look at multi-target optimization of a two-stage helical gearbox in order to determine the best key design elements for reducing gearbox height and enhancing gearbox efficiency.To do th... The goal of this research is to look at multi-target optimization of a two-stage helical gearbox in order to determine the best key design elements for reducing gearbox height and enhancing gearbox efficiency.To do this,the method known as Taguchi and GRA(Grey Relation Analysis)were used in two stages to address the problem.The single-objective optimization problem was addressed first to close the gap between variable levels,and then the multi-objective optimization problem was solved to determine the best primary design variables.The first and second stage CWFWs(Coefficients of Wheel Face Width),ACS(Permissible Contact Stresses),and first stage gear ratio were also calculated.The study’s findings were utilized to identify the best values for five critical design aspects of a two-stage helical gearbox. 展开更多
关键词 Helical gearbox multi-objective optimization gear ratio gearbox height gearbox efficiency.
下载PDF
Understanding Bridging Sites and Accelerating Quantum Efficiency for Photocatalytic CO_(2) Reduction 被引量:2
4
作者 Kangwang Wang Zhuofeng Hu +8 位作者 Peifeng Yu Alina M.Balu Kuan Li Longfu Li Lingyong Zeng Chao Zhang Rafael Luque Kai Yan Huixia Luo 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期68-84,共17页
We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in... We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR. 展开更多
关键词 Quantum efficiency Electronic structure Steric interaction Bridging sites CO_(2)reduction
下载PDF
Enhancing I^(0)/I^(-)Conversion Efficiency by Starch Confinement in Zinc-lodine Battery 被引量:1
5
作者 Danyang Zhao Qiancheng Zhu +4 位作者 Qiancheng Zhou Wenming Zhang Ying Yu Shuo Chen Zhifeng Ren 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第1期114-120,共7页
The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle li... The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs. 展开更多
关键词 aqueous battery conversion efficiency iodine-zinc battery starch confinement
下载PDF
Technical efficiency of cocoa farms at varying elevation levels in Davao City, Philippines: implications to sustainable upland farming systems 被引量:1
6
作者 Francis Levi A.DURANO Jon Marx SARMIENTO +1 位作者 Larry N.DIGAL Pedro A.ALVIOLA IV 《Journal of Mountain Science》 SCIE CSCD 2024年第1期33-48,共16页
Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa ... Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation areas. 展开更多
关键词 Cocoa farms Cobb-Douglas production function ELEVATION Philippines Stochastic frontier analysis Technical efficiency
下载PDF
Elucidating the enhancement of kaolinite flotation by iron content through density functional theory: A study on sodium oleate adsorption efficiency 被引量:1
7
作者 Lingyun Liu Chuilei Kong +1 位作者 Hongyu Zhao Fangqin Lu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第6期855-866,共12页
This study delves into the intricate relationship between iron(Fe)content in kaolinite and its impact on the adsorption behavior of sodium oleate.The effects of different iron concentrations on adsorption energy,hydro... This study delves into the intricate relationship between iron(Fe)content in kaolinite and its impact on the adsorption behavior of sodium oleate.The effects of different iron concentrations on adsorption energy,hydrogen bond kinetics and adsorption efficiency were studied through simulation and experimental verification.The results show that the presence of iron in the kaolinite structure significantly improves the adsorption capacity of sodium oleate.Kaolinite samples with high iron content have better adsorption properties,lower adsorption energy levels and shorter and stronger hydrogen bonds than pure kaolinite.The optimal concentration of oleic acid ions for achieving maximum adsorption efficiency was identified as 1.2 mmol/L across different kaolinite samples.At this concentration,the adsorption rates and capacities reach their peak,with Fe-enriched kaolinite samples exhibiting notably higher flotation recovery rates.This optimal concentration represents a balance between sufficient oleic acid ion availability for surface interactions and the prevention of self-aggregation phenomena that could hinder adsorption.This study offers promising avenues for optimizing the flotation process in mineral processing applications. 展开更多
关键词 Iron Influence Sodium Oleate Adsorption Kaolinite Surfaces Molecular Interaction Analysis Flotation efficiency Optimization
下载PDF
Microscopic characteristics of tight sandstone reservoirs and their effects on the imbibition efficiency of fracturing fluids:A case study of the Linxing area,Ordos Basin 被引量:1
8
作者 Qihui Li Dazhong Ren +6 位作者 Hu Wang Haipeng Sun Tian Li Hanpeng Zhang Zhen Yan Rongjun Zhang Le Qu 《Energy Geoscience》 EI 2024年第3期328-338,共11页
The Linxing area within the Ordos Basin exhibits pronounced reservoir heterogeneity and intricate micro-pore structures,rendering it susceptible to water-blocking damage during imbibition extraction.This study delved ... The Linxing area within the Ordos Basin exhibits pronounced reservoir heterogeneity and intricate micro-pore structures,rendering it susceptible to water-blocking damage during imbibition extraction.This study delved into the traits of tight sandstone reservoirs in the 8th member of the Shihezi Formation(also referred to as the He 8 Member)in the study area,as well as their effects on fracturing fluid imbibition.Utilizing experimental techniques such as nuclear magnetic resonance(NMR),high-pressure mercury intrusion(HPMI),and gas adsorption,this study elucidated the reservoir characteristics and examined the factors affecting the imbibition through imbibition experiments.The findings reveal that:①The reservoir,with average porosity of 8.40%and average permeability of 0.642×10^(-3)μm^(2),consists principally of quartz,feldspar,and lithic fragments,with feldspathic litharenite serving as the primary rock type and illite as the chief clay mineral;②Nano-scale micro-pores and throats dominate the reservoir,with dissolution pores and intercrystalline pores serving as predominant pore types,exhibiting relatively high pore connectivity;③Imbibition efficiency is influenced by petrophysical properties,clay mineral content,and microscopic pore structure.Due to the heterogeneity of the tight sandstone reservoir,microscopic factors have a more significant impact on the imbibition efficiency of fracturing fluids;④A comparative analysis shows that average pore size correlates most strongly with imbibition efficiency,followed by petrophysical properties and clay mineral content.In contrast,the pore type has minimal impact.Micropores are vital in the imbibition process,while meso-pores and macro-pores offer primary spaces for imbibition.This study offers theoretical insights and guidance for enhancing the post-fracturing production of tight sandstone reservoirs by examining the effects of these factors on the imbibition efficiency of fracturing fluids in tight sandstones. 展开更多
关键词 Tight sandstone Ordos Basin Fracturing fluid Microscopic reservoir characteristics Imbibition efficiency Influencing factor
下载PDF
Research on a TOPSIS energy efficiency evaluation system for crude oil gathering and transportation systems based on a GA-BP neural network 被引量:1
9
作者 Xue-Qiang Zhang Qing-Lin Cheng +2 位作者 Wei Sun Yi Zhao Zhi-Min Li 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期621-640,共20页
As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crud... As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems. 展开更多
关键词 Crude oil gathering and transportation system GA-BP neural network Energy efficiency evaluation TOPSIS evaluation method Energy saving and consumption reduction
下载PDF
Does Financial Inclusion Influence Economic Efficiency of Rice Farming? Evidence from Ogun State, Nigeria
10
作者 Shakirat B.IBRAHIM Raheem O.AMINU +2 位作者 Aisha O.AROWOLO Opeyemi O.OKANLAWON Afeez A.ADEGBOLA 《Rice science》 SCIE CSCD 2024年第6期638-642,I0012-I0014,共8页
Local production of rice has struggled to meet local demand despite its suitability for cultivation in many parts of Nigeria.Using data from 240 rice farmers, this study examined the economic efficiency of rice produc... Local production of rice has struggled to meet local demand despite its suitability for cultivation in many parts of Nigeria.Using data from 240 rice farmers, this study examined the economic efficiency of rice production and the effects of financial inclusion on the economic efficiency of rice farming in Ogun State, Nigeria. Data were analyzed using the Stochastic Cost Frontier model with inefficiency effects. 展开更多
关键词 NIGERIA SUITABILITY efficiency
下载PDF
Two-Stage Approach for Targeted Knowledge Transfer in Self-Knowledge Distillation
11
作者 Zimo Yin Jian Pu +1 位作者 Yijie Zhou Xiangyang Xue 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第11期2270-2283,共14页
Knowledge distillation(KD) enhances student network generalization by transferring dark knowledge from a complex teacher network. To optimize computational expenditure and memory utilization, self-knowledge distillati... Knowledge distillation(KD) enhances student network generalization by transferring dark knowledge from a complex teacher network. To optimize computational expenditure and memory utilization, self-knowledge distillation(SKD) extracts dark knowledge from the model itself rather than an external teacher network. However, previous SKD methods performed distillation indiscriminately on full datasets, overlooking the analysis of representative samples. In this work, we present a novel two-stage approach to providing targeted knowledge on specific samples, named two-stage approach self-knowledge distillation(TOAST). We first soften the hard targets using class medoids generated based on logit vectors per class. Then, we iteratively distill the under-trained data with past predictions of half the batch size. The two-stage knowledge is linearly combined, efficiently enhancing model performance. Extensive experiments conducted on five backbone architectures show our method is model-agnostic and achieves the best generalization performance.Besides, TOAST is strongly compatible with existing augmentation-based regularization methods. Our method also obtains a speedup of up to 2.95x compared with a recent state-of-the-art method. 展开更多
关键词 Cluster-based regularization iterative prediction refinement model-agnostic framework self-knowledge distillation(SKD) two-stage knowledge transfer
下载PDF
Two-Stage Optimal Scheduling of Community Integrated Energy System
12
作者 Ming Li Rifucairen Fu +4 位作者 Tuerhong Yaxiaer Yunping Zheng Abiao Huang Ronghui Liu Shunfu Lin 《Energy Engineering》 EI 2024年第2期405-424,共20页
From the perspective of a community energy operator,a two-stage optimal scheduling model of a community integrated energy system is proposed by integrating information on controllable loads.The day-ahead scheduling an... From the perspective of a community energy operator,a two-stage optimal scheduling model of a community integrated energy system is proposed by integrating information on controllable loads.The day-ahead scheduling analyzes whether various controllable loads participate in the optimization and investigates the impact of their responses on the operating economy of the community integrated energy system(IES)before and after;the intra-day scheduling proposes a two-stage rolling optimization model based on the day-ahead scheduling scheme,taking into account the fluctuation of wind turbine output and load within a short period of time and according to the different response rates of heat and cooling power,and solves the adjusted output of each controllable device.The simulation results show that the optimal scheduling of controllable loads effectively reduces the comprehensive operating costs of community IES;the two-stage optimal scheduling model can meet the energy demand of customers while effectively and timely suppressing the random fluctuations on both sides of the source and load during the intra-day stage,realizing the economic and smooth operation of IES. 展开更多
关键词 Integrated energy system two-stage optimal scheduling controllable loads rolling optimization
下载PDF
Enhancing Energy Efficiency with a Dynamic Trust Measurement Scheme in Power Distribution Network
13
作者 Yilei Wang Xin Sun +4 位作者 Guiping Zheng Ahmar Rashid Sami Ullah Hisham Alasmary Muhammad Waqas 《Computers, Materials & Continua》 SCIE EI 2024年第3期3909-3927,共19页
The application of Intelligent Internet of Things(IIoT)in constructing distribution station areas strongly supports platform transformation,upgrade,and intelligent integration.The sensing layer of IIoT comprises the e... The application of Intelligent Internet of Things(IIoT)in constructing distribution station areas strongly supports platform transformation,upgrade,and intelligent integration.The sensing layer of IIoT comprises the edge convergence layer and the end sensing layer,with the former using intelligent fusion terminals for real-time data collection and processing.However,the influx of multiple low-voltage in the smart grid raises higher demands for the performance,energy efficiency,and response speed of the substation fusion terminals.Simultaneously,it brings significant security risks to the entire distribution substation,posing a major challenge to the smart grid.In response to these challenges,a proposed dynamic and energy-efficient trust measurement scheme for smart grids aims to address these issues.The scheme begins by establishing a hierarchical trust measurement model,elucidating the trust relationships among smart IoT terminals.It then incorporates multidimensional measurement factors,encompassing static environmental factors,dynamic behaviors,and energy states.This comprehensive approach reduces the impact of subjective factors on trust measurements.Additionally,the scheme incorporates a detection process designed for identifying malicious low-voltage end sensing units,ensuring the prompt identification and elimination of any malicious terminals.This,in turn,enhances the security and reliability of the smart grid environment.The effectiveness of the proposed scheme in pinpointing malicious nodes has been demonstrated through simulation experiments.Notably,the scheme outperforms established trust metric models in terms of energy efficiency,showcasing its significant contribution to the field. 展开更多
关键词 IIoT trusted measure energy efficient
下载PDF
Solar-assisted two-stage catalytic membrane reactor for coupling CO_(2) splitting with methane oxidation reaction
14
作者 Jinkun Tan Zhenbin Gu +4 位作者 Zhengkun Liu Pei Wang Reinout Meijboom Guangru Zhang Wanqin Jin 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第11期1771-1780,共10页
A two-stage catalytic membrane reactor(CMR)that couples CO_(2) splitting with methane oxidation reactions was constructed based on an oxygen-permeable perovskite asymmetric membrane.The asymmetric membrane comprises a... A two-stage catalytic membrane reactor(CMR)that couples CO_(2) splitting with methane oxidation reactions was constructed based on an oxygen-permeable perovskite asymmetric membrane.The asymmetric membrane comprises a dense SrFe_(0.9)Ta_(0.1)O_(3-σ)(SFT)separation layer and a porous Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Cu_(0.1)O_(3-σ)(SFTC)catalytic layer.In thefirst stage reactor,a CO_(2) splitting reaction(CDS:2CO_(2)→2CO+O_(2))occurs at the SFTC catalytic layer.Subsequently,the O_(2) product is selectively extracted through the SFT separation layer to the permeated side for the methane combustion reaction(MCR),which provides an extremely low oxygen partial pressure to enhance the oxygen extraction.In the second stage,a Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Ni_(0.1)O_(3-σ)(SFTN)catalyst is employed to reform the products derived from MCR.The two-stage CMR design results in a remarkable 35.4%CO_(2) conversion for CDS at 900℃.The two-stage CMR was extended to a hollowfiber configuration combining with solar irradiation.The solar-assisted two-stage CMR can operate stably for over 50 h with a high hydrogen yield of 18.1 mL min^(-1) cm^(-2).These results provide a novel strategy for reducing CO_(2) emissions,suggesting potential avenues for the design of the high-performance CMRs and catalysts based on perovskite oxides in the future. 展开更多
关键词 CO_(2)splitting two-stage catalytic membrane reactor Perovskite oxide Asymmetric membrane Solar irradiation assisted
下载PDF
Effect of building energy efficiency standards on carbon emission efficiency in commercial buildings
15
作者 Xia Wang Qi Ye +1 位作者 Yan Du Mao Zhou 《Chinese Journal of Population,Resources and Environment》 2024年第3期250-257,共8页
The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,expl... The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation. 展开更多
关键词 Commercial buildings Carbon emissions efficiency Building energy efficiency standards Slack-based measure–data development analysis Difference in differences
下载PDF
Assessing the yield difference of double-cropping rice in South China driven by radiation use efficiency
16
作者 Jian Lu Sicheng Deng +6 位作者 Muhammad Imran Jingyin Xie Yuanyuan Li Jianying Qi Shenggang Pan Xiangru Tang Meiyang Duan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第11期3692-3705,共14页
Double-cropping rice in South China continues to break the total yield record,but the yield potential of singlecropping rice is not being realized.Radiation use efficiency(RUE)has been singled out as an important dete... Double-cropping rice in South China continues to break the total yield record,but the yield potential of singlecropping rice is not being realized.Radiation use efficiency(RUE)has been singled out as an important determinant of grain yield in many cereal species.However,there is no information on whether the yield gaps in doublecropping rice involve differences in RUE.Field experiments were performed over two years to evaluate the effects of intercepted radiation(IP)and RUE on the above-ground biomass production,crop growth rate(CGR),and harvest index(HI),in four representative rice varieties,i.e.,Xiangyaxiangzhan(XYXZ),Meixiangzhan 2(MXZ2),Nanjingxiangzhan(NJXZ),and Ruanhuayoujinsi(RHYJS),during the early and late seasons of rice cultivation in South China.The results revealed that grain yield in the early season was 8.2%higher than in the late season.The yield advantage in the early season was primarily due to higher spikelets per panicle and above-ground biomass resulting from a higher RUE.The spikelets per panicle in the early season were 6.5,8.3,6.9,and 8.5%higher in XYXZ,MXZ2,NJXZ,and RHYJS,respectively,than in the late season.The higher early season grain yield was more closely related to RUE in the middle tillering stage(R^(2)=0.34),panicle initiation(R^(2)=0.16),and maturation stage(R^(2)=0.28),and the intercepted photosynthetically active radiation(IPAR)in the maturation stage(R^(2)=0.28),while the late season grain yield was more dependent on IPAR in the middle tillering stage(R^(2)=0.31)and IPAR at panicle initiation(R^(2)=0.23).The results of this study conclusively show that higher RUE contributes to the yield progress of early season rice,while the yield improvement of late season rice is attributed to higher radiation during the early reproductive stage.Rationally allocating the RUE of double-cropping rice with high RUE varieties or adjustments of the sowing period merits further study. 展开更多
关键词 grain yield radiation use efficiency double-cropping rice
下载PDF
Effect of antioxidants on the efficiency of jet milling and the powder characteristics of Sm2Co17 permanent magnets
17
作者 Da-Shuai Xu Lei Liu +6 位作者 Jian-Hui Yuan Bo Zhou Chuang-Hui Dong Feng-Qing Wang Yong Ding Ying-Li Sun A-Ru Yan 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期615-620,共6页
This study investigated the effect of antioxidants on the grinding efficiency,magnetic powder characteristics,microstructure,and magnetic properties of 2:17 type SmCo permanent magnet materials.The results show that a... This study investigated the effect of antioxidants on the grinding efficiency,magnetic powder characteristics,microstructure,and magnetic properties of 2:17 type SmCo permanent magnet materials.The results show that adding antioxidants helps improve the dispersion among magnetic powders,leading to a 33.3%decrease in jet milling time and a 15.8%increase in magnet powder production yield.Additionally,adding antioxidants enhances the oxidation resistance of the magnetic powders.After being stored in a constant temperature air environment at 25C for 48 h,the O content in the powder decreased by 33%compared to samples without antioxidants.While in the magnet body,the O content decreased from 0.21 wt.%to 0.14 wt.%,which helps increase the effective Sm content and domain wall pinning uniformity in the magnet.Excellent magnetic properties were obtained in the magnet with added antioxidants:B_(r)=11.6 kGs,SF=79.6%,H_(cj)=16.8 kOe,and(BH)_(max)=32.5 MGOe. 展开更多
关键词 ANTIOXIDANT SmCo permanent magnet oxidation resistance grinding efficiency
下载PDF
The Impact of Privatization on Terminal Efficiency: A Case Study of Tema Port
18
作者 Bernard Kwei Tetteh Calvin Elorm Atsunyo Alex Boateng 《Journal of Transportation Technologies》 2024年第3期358-371,共14页
Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been ... Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been notable variations of studies around it. This paper analyzes the impact of privatization on terminal efficiency using the Port of Tema as a Case Study. The main objective of this paper is to analyze the efficiency trends of the public and private terminals in the port over the years. To achieve this objective, DEA-CCR methodology was employed to calculate the annual technical efficiency trends of the private and public terminals using four input variables and three output variables. The main results of the paper indicated that the public and private terminals were efficient for multiple years. However, the efficiency scores over the years demonstrated inconsistency, exhibiting notable fluctuations. The findings of this study will aid policymakers across the region on policies relating to the efficiency and ownership structure of ports and terminals. 展开更多
关键词 PRIVATIZATION Terminal efficiency DEA Tema Port
下载PDF
Spatial-temporal Divergence Characteristics and Driving Factors of Green Economic Efficiency in the Yangtze River Economic Belt of China
19
作者 PAN Ting JIN Gui +1 位作者 ZENG Shibo WANG Rui 《Chinese Geographical Science》 SCIE CSCD 2024年第6期1158-1174,共17页
The spatial and temporal variation of green economic efficiency and its driving factors are of great significance for the construction of high-efficiency and low-consumption green development model and sustainable soc... The spatial and temporal variation of green economic efficiency and its driving factors are of great significance for the construction of high-efficiency and low-consumption green development model and sustainable socio-economic development.The research focused on the Yangtze River Economic Belt(YREB)and employed the miniumum distance to strong efficient frontier DEA(MinDs)model to measure the green economic efficiency of the municipalities in the region between 2008 and 2020.Then,the spatial autocorrelation model was used to analyze the evolution characteristics of its spatial pattern.Finally,Geodetector was applied to reveal the drivers and their interactions on green economic efficiency.It is found that:1)the overall green economic efficiency of the YREB from 2008 to 2020 shows a W-shaped fluctuating upward trend,green economic efficiency is greater in the downstream and smallest in the upstream;2)the spatial distribution of green economic efficiency shows clustering characteristics,with multi-core clustering based on‘city clusters-central cities'becoming more obvious over time;the High-High agglomeration type is mainly clustered in Jiangsu and Zheji-ang,while the Low-Low agglomeration type is clustered in the western Sichuan Plateau area and southwestern Yunnan;3)from input-output factors,whether it is the YREB as a whole or the upper,middle and lower reaches regions,the economic development level,labor input,and capital investment are the leading factors in the spatial-temporal evolution of green economic efficiency,with the com-prehensive influence of economic development level and pollution index being the most important interactive driving factor;4)from so-cio-economic factors,information technology drivers such as government intervention,transportation accessibility,information infra-structure,and Internet penetration are always high impact influencers and dominant interaction factors for green economic efficiency in the YREB and the three major regions in the upper,middle and lower reaches.Accordingly,the article puts forward relevant policy re-commendations in terms of formulating differentiated green transformation strategies,strengthening network leadership and informa-tion technology construction and coordinating multi-factor integrated development,which could provide useful reference for promoting synergistic green economic efficiency in the YREB. 展开更多
关键词 green economic efficiency miniumum distance to strong efficient frontier DEA(MinDs) spatial-temporal evolution Geo-detector Yangtze River Economic Belt(YREB) China
下载PDF
OsNPF3.1,a nitrate,abscisic acid and gibberellin transporter gene,is essential for rice tillering and nitrogen utilization efficiency
20
作者 Junnan Hang Bowen Wu +3 位作者 Diyang Qiu Guo Yang Zhongming Fang Mingyong Zhang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1087-1104,共18页
Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone ... Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively. 展开更多
关键词 rice tillering grain yield PHYTOHORMONE NITRATE transporter nitrogen utilization efficiency
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部