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Efficient unequal error protection for online fountain codes

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Journal of Systems Engineering and Electronics 2024年第2期35卷 286-293页

作者： SHI Pengcheng WANG Zhenyong li Dezhi lyu Haibo School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Shenzhen Academy of Aerospace Technology Shenzhen 518057China

In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is *** the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in the completion phase,the weighted-selection strategy is applied to provide low *** performance of the proposed scheme is analyzed and compared with the existing UEP online fountain *** results show that in terms of MIS and the least important symbols(liS),when the bit error ratio is 10-4,the proposed scheme can achieve 85%and 31.58%overhead reduction,respectively.

关键词： online fountain code random graph unequal error protection(UEP) rateless code

Effects of Co-Firing Biomass and Pulverized Coal on NO Reduction in Cement Precalciner

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Journal of Thermal Science 2024年第2期33卷 751-760页

作者： li Pengpeng REN Qiangqiang lyu Qinggang WANG Mingyue School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

With increased awareness of the large-scale CO_(2) emissions from the cement industry,there has been growing focus on greenhouse gas reduction *** all these strategies,fuel substitution using biomass fuel is extensively used to achieve CO_(2) zero-emission in cement *** to the avoidable high-temperature-generated thermal nitrogen oxides during cement production,research on the impact of biomass application on nitrogen oxide emissions shall be carried *** types of biomass fuel and bituminous coal were used to investigate the NO reduction characteristics under different O_(2) concentrations on experimental *** was found that the change in oxygen concentration from 9% to 1% increased the reaction time in the reactor from 555 s to 1425 s,which means the increase in oxygen concentration can lead to shorter reaction time,and correspondingly,the existing time of nitric oxide in the flue gas is also shortened,but the peak value of nitric oxide rises,during the process of O_(2) concentration changing from 1% to 9%,the peak NO concentration in the flue gas increased from 5.4×10^(-5) to 1.05×10^(-4).An increase in O_(2) concentration greatly reduces the total reduction of NO and the minimum change in NO *** peak NO concentration during the combustion process of corn stalk is 4.56×10^(-4),which is approximately 7 times higher than that of coal,and it is caused by the high amount of N in corn *** addition of raw meal has an inhibitory effect on the reduction of NO:after adding raw meal,the effective reduction time of NO by fuel decreased by about 20%,but adding raw meal raises CO_(2) concentration of fuel gas in the early stage of reaction.

关键词： cement precalciner biomass fuel coal NO reduction co-firing

Investigation and measurement of old building response to the overlapped shield tunnel of multiple schemes in the sandy cobble stratum

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Underground Space 2024年第2期15卷 260-274页

作者： xue li Aopeng Geng School of Geoscience and Technology Southwest Petroleum UniversityChengduSichuan 610500China China Railway Construction Bridge Engineering Bureau Group Co. Ltd.Tianjin 300300China

Ground movements due to tunneling are becoming increasingly critical as buildings are located around construction *** study proposes a new combined reinforcement method using a foundation grouting oblique pipe *** former improves the bearing capacity of the subsoil,and the latter blocks the transmission of soil deformation,which weakens the influence of construction during overlapped tunnel *** on this new method,a case study of the shield tunneling response to an old building in line 6 of China’s Chengdu Metro is ***,three-dimensional numerical models without reinforcement,traditional foundation grouting reinforcement,and the new combined reinforcement schemes were *** numerical simulation performance was verified using a set of field instrumentation data,which demonstrated that the old building response to the overlapped tunnels was under control,and the maximum deformation,angular distortion,and principal tensile strain of the building were 5.25 mm,5.1010–6 rad/m,and 0.0081%,*** with the traditional reinforcement scheme,the deformation,angular distortion,and principal tensile strain in the combined reinforcement scheme were reduced by 54.78%,71.02%,and 70.22%,*** results have important implications for the design and construction of shield tunnels and their response to old buildings.

关键词： Overlapped tunnels Reinforcement schemes Under-crossing Old building Numerical simulation

Sustainable Intensification and Large-scale Operation of Cultivated Land Use at the Farmers’ Scale:A Case Study of Shandong Province,China

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Chinese Geographical Science 2024年第1期34卷 149-167页

作者： li li lyu Xiao ZHANG Anlu NIU Shandong PENG Wenlong School of Public Administration Huazhong Agricultural UniversityWuhan430070China Department of Geography University of ZurichZurich8057Switzerland School of Humanities and Law Northeastern UniversityShenyang110169China School of Geography and Tourism Qufu Normal UniversityRizhao276800China

Sustainable intensification of cultivated land use(SICLU) and large-scale operations(LSO) are widely acknowledged strategies for enhancing agricultural ***,the existing literature has faced challenges in precisely defining SICLU and constructing comprehensive indicators,which has hindered the exploration of factors influencing LSO within the SICLU *** address this gap,we integrated self-efficacy theory into the design of an index framework for evaluating *** subsequently employed econometric models to analyze the significant factors that impact *** findings reveal that SICLU can be divided into four key dimensions:intensive management,efficient output,resource conservation,and ecological environment ***,it is crucial to incorporate belief-based cognitive factors into the index system,as farmers’ understanding of fertilizer and pesticide application significantly influences their willingness to engage in ***,we identify grain market turnover as the most influential factor in promoting LSO,with single-factor contribution rates reaching 70.9% for cultivated land transfer willingness and 62.5% for the total planting ***,unlike irrigation and agricultural machinery inputs,increased labor inputs correspond to larger planting areas for *** trend may be attributed to reduced labor availability because of rural labor migration,whereas the reduction in irrigation and agricultural input is contingent on innovations in production practices and the transfer of cultivated land management ***,SICLU dynamically influences LSO,with each index related to SICLU having an optimal range that fosters *** insights offer valuable guidance for policymakers,emphasizing farmers as their central focus,with the adjustment of input and output factors as a means to achieve LSO as the ultimate *** conclusion,we propose research avenues for further enriching the SICLU framework to ensur

关键词： sustainable intensification of cultivated land use(SICLU) self-efficacy status quo bias input and output Boosted Regression Tree willingness to transfer cultivated land cultivated land planting areas Shandong,China

Engineering a non-model yeast Rhodotorula mucilaginosa for terpenoids synthesis

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Synthetic and Systems Biotechnology 2024年第3期9卷 569-576页

作者： Qiongqiong Chen liting lyu Haizhao xue Aabid Manzoor Shah Zongbao Kent Zhao Laboratory of Biotechnology Dalian Institute of Chemical PhysicsCAS457 Zhongshan RoadDalian116023China MOE Key Laboratory of Bio-Intelligent Manufacturing School of BioengineeringDalian University of TechnologyDalian116024China University of Chinese Academy of Sciences 19 Yuquan RoadBeijing100049China

Terpenoids have tremendous biological activities and are widely employed in food,healthcare and pharmaceutical *** synthetic biology to product terpenoids from microbial cell factories presents a promising alternative route compared to conventional methods such as chemical synthesis or *** red yeast Rhodotorula mucilaginosa has been widely studied due to its natural production capacity of carotenoid and lipids,indicating a strong endogenous isoprene pathway with readily available metabolic *** study constructed several engineered strains of *** with the aim of producing different ***α-terpineol was produced by expressing theα-terpineol synthase from Vitis *** titer ofα-terpineol was further enhanced to 0.39 mg/L by overexpressing the endogenous rate-limiting gene of the MVA *** ofα-farnesene synthase from Malus domestica,in combination with MVA pathway rate-limiting gene resulted in significant increase inα-farnesene production,reaching a titer of 822 mg/*** carotenoid degradation productβ-ionone was produced at a titer of 0.87 mg/L by expressing theβ-ionone synthase from Petunia *** study demonstrates the potential of *** as a platform host for the direct biosynthesis of various terpenoids and provides insights for further development of such platforms.

关键词： Rhodotorula mucilaginosa Synthetic biology α-Terpineol β-Ionone α-Farnesene

Modification of Melting Combustion Kinetic Model of Fine Ash from Entrained-Flow Gasifier

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Journal of Thermal Science 2024年第1期33卷 300-310页

作者： WANG Wenyu li Wei LU Yu REN Qiangqiang lyu Qinggang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Coal gasification technology is a prominent technology in the coal chemical industry and serves as the fundamental basis for various process industries,including coal-based chemicals,coal-based liquid fuels,Integrated Gasification Combined Cycle(IGCC) power generation,multi-generation systems,hydrogen production,and fuel *** gasification process generates significant quantities of ash residue,with annual emissions exceeding tens of millions of tons and accumulation reaching hundreds of millions of ***,there is an urgent need to investigate methods for its *** combustion of gasified fine ash(GFA) was conducted in a tube furnace,and the conventional shrinking core model was modified to accurately predict the combustion behaviors at different temperatures(900℃-1500℃).We divided the reaction temperatures into three ranges,which is defined as unmelted combustion(TFT) and mixed combustion(DTFT),the surface ash of GFA grains fell off,and the residual carbon and gas-phase reactants were nearly no longer affected by the diffusion resistance,thus significantly accelerated the reaction of internal residual *** order to predict the melt combustion process more accurately,the time term of the shrinkage core model(SCM) is modified,and the effective diffusion coefficient of T>FT is defined.

关键词： fine ash melting combustion kinetic model combustion characteristics

Fast fixed-time three-dimensional terminal guidance with non-concave trajectory constraint

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Chinese Journal of Aeronautics 2024年第3期37卷 208-218页

作者： Youmin GONG Yanning GUO Yueyong lyu Dongyu li Guangfu MA Department of Control Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Cyber Science and Technology Beihang UniversityBeijing 100191China

Focusing on the non-concave trajectory constraint,a sliding-mode-based nonsingular feedback fast fixed-time three-dimensional terminal guidance of rotor unmanned aerial vehicle landing,planetary landing and spacecraft rendezvous and docking terminal phase with external disturbance is investigated in this ***,a fixed-time observer based on real-time differentiator is developed to compensate for the external disturbance,whose estimation error can converge to zero after a time independent of the initial ***,a sliding surface ensuring fixed-time convergence is *** sliding surface can guarantee that the vehicle achieves a non-concave trajectory,which is better for avoiding collision and maintaining the visibility of the landing site or docking ***,the nonsingular guidance ensuring the fixed-time convergence of the sliding surface is proposed,which is continuous and chatter *** last,three numerical simulations of Mars landing are performed to validate the effectiveness and correctness of the designed scheme.

关键词： Three-dimensional Terminal guidance Non-concave trajectory constraint Fast fixed-time control Sliding mode control

Oscillation Characteristics Analysis and Equivalent Modeling of Multiple CIGs Connected to Weak Grid

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2004-2015页

作者： Longyuan li Ruiqing Fu Xiaoqin lyu Xiaoru Wang School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China

The stability problem of weak grid connected converter interfaced generation(CIG)cannot be *** multiple weak grid connected CIGs with different parameters,the system oscillation characteristics and equivalence methods still need to be further *** paper first discusses the oscillation characteristics when CIGs are perfectly coupled,perfectly decoupled and their general conditions *** on the Monte Caro simulation,the number of critical eigenvalues,the participation of each CIG to critical eigenvalues and the correlative parameters to participation are *** the single-CIG and multi-CIG equivalence methods are proposed for stations containing nonidentical *** CIG parameters of a single-CIG equivalent model are identified based on the consistency of the output admittance *** to the different participations of CIGs with critical eigenvalues,the station is equivalent to a multi-CIG *** of large simulation samples show that the two equivalent models can both preserve the critical eigenvalues very well,and can be used for stability ***,the multi-CIG equivalent model can also very well reflect the participation of CIGs in detailed models,and can be used for damping control study.

关键词： Critical eigenvalues equivalence Monte Caro simulation multiple CIGs participation weak grid

Low H_(2)O_(2)consumption Fenton-like catalysts for pollutant cleavage based on the construction of a dual reaction center

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Journal of Environmental Sciences 2024年第11期145卷 107-116页

作者： Weixiang liao Ziwen Zhao Lai lyu Chun Hu Fan li Key Laboratory for Water Quality and Conservation of the Pearl River Delta Ministry of EducationInstitute of Environmental Research at Greater BayGuangzhou UniversityGuangzhou 510006China Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510345China

High energy consumption has seriously hindered the development of Fenton-like reactions for the removal of refractory organic pollutants in *** solve this problem,we designed a novel Fenton-like catalyst(Cu-PAN3)by coprecipitation and carbon thermal *** catalyst exhibits excellent Fenton-like catalytic activity and stability for the degradation of various pollutants with low H_(2)O_(2)*** experimental results indicate that the dual reaction centers(DRCs)are composed of Cu-N-C and Cu-O-C bridges between copper and graphene-like carbon,which form electron-poor/rich centers on the catalyst surface.H_(2)O_(2)is mainly reduced at electron-rich Cu centers to free radicals for pollutant ***,pollutants can be oxidized by donating electrons to the electron-poor C centers of the catalyst,which inhibits the ineffective decomposition of H_(2)O_(2)at the electron-poor *** therefore significantly reduces the consumption of H_(2)O_(2)and reduces energy consumption.

关键词： Water purification Fenton-like Dual reaction centers Graphene-like carbon Low H_(2)O_(2)consumption