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Induction System for a Fusion Reactor: Quantum Mechanics Chained up
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作者 Friedrich Björn Grimm 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期158-166,共9页
In the quest for a sustainable and abundant energy source, nuclear fusion technology stands as a beacon of hope. This study introduces a groundbreaking quantum mechanically effective induction system designed for magn... In the quest for a sustainable and abundant energy source, nuclear fusion technology stands as a beacon of hope. This study introduces a groundbreaking quantum mechanically effective induction system designed for magnetic plasma confinement within fusion reactors. The pursuit of clean energy, essential to combat climate change, hinges on the ability to harness nuclear fusion efficiently. Traditional approaches have faced challenges in plasma stability and energy efficiency. The novel induction system presented here not only addresses these issues but also transforms fusion reactors into integrated construction systems. This innovation promises compact fusion reactors, marking a significant step toward a clean and limitless energy future, free from the constraints of traditional power sources. This revolutionary quantum induction system redefines plasma confinement in fusion reactors, unlocking clean, compact, and efficient energy production. 展开更多
关键词 Fusion Reactor Plasma Confinement Quantum Mechanics Clean Energy
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Data-Driven Control of Distributed Event-Triggered Network Systems 被引量:2
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作者 Xin Wang Jian Sun +2 位作者 Gang Wang Frank Allgower Jie Chen 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期351-364,共14页
The present paper deals with data-driven event-triggered control of a class of unknown discrete-time interconnected systems(a.k.a.network systems).To this end,we start by putting forth a novel distributed event-trigge... The present paper deals with data-driven event-triggered control of a class of unknown discrete-time interconnected systems(a.k.a.network systems).To this end,we start by putting forth a novel distributed event-triggering transmission strategy based on periodic sampling,under which a model-based stability criterion for the closed-loop network system is derived,by leveraging a discrete-time looped-functional approach.Marrying the model-based criterion with a data-driven system representation recently developed in the literature,a purely data-driven stability criterion expressed in the form of linear matrix inequalities(LMIs)is established.Meanwhile,the data-driven stability criterion suggests a means for co-designing the event-triggering coefficient matrix and the feedback control gain matrix using only some offline collected state-input data.Finally,numerical results corroborate the efficacy of the proposed distributed data-driven event-triggered network system(ETS)in cutting off data transmissions and the co-design procedure. 展开更多
关键词 Data-driven control distributed event-triggered network system(ETS) linear matrix inequalitie(LMI) looped-functional STABILITY
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三种溅射深度剖析定量分析模型解析表达式的比较
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作者 钟凤敏 王穗鹏 +4 位作者 郑锦权 杨浩 Siegfried Hofmann 徐从康 王江涌 《真空》 CAS 2023年第3期24-41,共18页
本文系统地讨论了三种广泛应用于溅射深度剖析定量分析的原子混合-粗糙度-信息深度(MRI)模型、上下坡(UDS)模型与粗糙度-级联混合-反冲注入(RMR)模型的解析表达式。先从定义、公式推导、仿真结果分析三方面逐一分析了这三种模型对应的... 本文系统地讨论了三种广泛应用于溅射深度剖析定量分析的原子混合-粗糙度-信息深度(MRI)模型、上下坡(UDS)模型与粗糙度-级联混合-反冲注入(RMR)模型的解析表达式。先从定义、公式推导、仿真结果分析三方面逐一分析了这三种模型对应的剖面特征,再通过其对应的深度分辨率子函数、深度分辨率函数、分析膜层厚度的解析表达式以及实验数据的拟合,将三种模型进行了细致的比较。最后解释了上下坡模型存在的不足,纠正了粗糙度-级联混合-反冲注入模型存在的错误描述,实测/模拟深度剖面的动态特性验证了原子混合-粗糙度-信息深度模型的可靠性和优越性。 展开更多
关键词 深度剖析定量分析 原子混合-粗糙度-信息深度模型 上下坡模型 粗糙度-级联混合-反冲注入模型 解析表达式 动态特性
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微尺度声操控研究及其生物学应用
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作者 Zhichao Ma Peer Fischer 《Engineering》 SCIE EI CAS CSCD 2023年第5期13-16,I0001,共5页
Acoustic waves-and ultrasound waves in particular-are biocompatible,with excellent transmission through biological tissues.Furthermore,the wavelength and intensity of acoustic waves can be tuned over several orders of... Acoustic waves-and ultrasound waves in particular-are biocompatible,with excellent transmission through biological tissues.Furthermore,the wavelength and intensity of acoustic waves can be tuned over several orders of magnitude.Most notably,the commonly used 10–300 MHz frequency range is attractive for biomedical applications,as its wavelength in water(5–150μm)corresponds to the cellular-length scale. 展开更多
关键词 声操控 生物学应用 微尺度
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Extremely fast vortex dynamics in Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ) crystalline nanostrip
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作者 于奥博 林成天 +1 位作者 张孝富 尤立星 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期563-568,共6页
The maximum velocity of a mobile vortex in movement is generally limited by the phenomenon of flux-flow instability(FFI),which necessitates weak vortex pinning and fast heat removal from non-equilibrium electrons.We h... The maximum velocity of a mobile vortex in movement is generally limited by the phenomenon of flux-flow instability(FFI),which necessitates weak vortex pinning and fast heat removal from non-equilibrium electrons.We here demonstrate exfoliations and nano-fabrications of Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ) crystalline nanostrips,which possess a rather weak pinning volume of vortices,relatively low resistivity,and large normal electron diffusion coefficient.The deduced vortex velocity in Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ) crystalline nanostrips can be up to 300 km/s near the superconducting transition temperature,well above the speed of sound.The observed vortex velocity is an order of magnitude faster than that of conventional superconducting systems,representing a perfect platform for exploration of ultra-fast vortex matter and a good candidate for fabrications of superconducting nanowire single photon detectors or superconducting THz modulator. 展开更多
关键词 Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ)(Bi2223) vortices dynamics ultra thin single crystal nanowire
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Hydrogen production at intermediate temperatures with proton conducting ceramic cells:Electrocatalytic activity,durability and energy efficiency
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作者 Haoyu Zheng Feng Han +1 位作者 Noriko Sata Rémi Costa 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期437-446,I0010,共11页
Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatur... Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis(PCCEL).We demonstrate a highperformance steam electrolysis owing to a composite positrode based on BaGd_(0.8)La_(0.2)Co_(2)O_(6-δ)(BGLC1082)and BaZr0.5Ce0.4Y0.1O3-δ(BZCY541).The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as-0.8 A cm^(-2)close to the thermoneutral cell voltage at 600℃.The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg^(-1)that is comparable to state-of-the-art low temperature electrolysis technologies,while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells(SOCs).Compared to SOCs,the results verified the higher performances of PCCs at the relevant operating temperatures,due to the lower activation energy for proton transfer comparing with oxygen ion conduction.However,because of the p-type electronic conduction in protonic ceramics,the energy conversion rate of PCCs is relatively lower in steam electrolysis.The faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions,making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into hydrogen.To increase the faradaic efficiency by optimizing the materials,the cell design,or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits. 展开更多
关键词 Steam electrolysis Hydrogen production Proton conducting ceramics Intermediate temperature Energy efficiency
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Intrinsic electronic structure and nodeless superconducting gap of YBa_(2)Cu_(3)O_(7)-σ observed by spatially-resolved laser-based angle resolved photoemission spectroscopy
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作者 李帅帅 苗泰民 +17 位作者 殷超辉 李颖昊 闫宏涛 陈逸雯 梁波 陈浩 朱文培 张申金 王志敏 张丰丰 杨峰 彭钦军 林成天 毛寒青 刘国东 许祖彦 赵林 周兴江 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期263-268,共6页
The spatially-resolved laser-based high-resolution angle resolved photoemission spectroscopy(ARPES) measurements have been performed on the optimally-doped YBa_(2)Cu_(3)O_(7)-σ(Y123) superconductor. For the first tim... The spatially-resolved laser-based high-resolution angle resolved photoemission spectroscopy(ARPES) measurements have been performed on the optimally-doped YBa_(2)Cu_(3)O_(7)-σ(Y123) superconductor. For the first time, we found the region from the cleaved surface that reveals clear bulk electronic properties. The intrinsic Fermi surface and band structures of Y123 were observed. The Fermi surface-dependent and momentum-dependent superconducting gap was determined which is nodeless and consistent with the d+is gap form. 展开更多
关键词 YBCO angle resolved photoemission spectroscopy electronic structure superconducting gap
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A Low Mach Number IMEX Flux Splitting for the Level Set Ghost Fluid Method
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作者 Jonas Zeifang Andrea Beck 《Communications on Applied Mathematics and Computation》 2023年第2期722-750,共29页
Considering droplet phenomena at low Mach numbers,large differences in the magnitude of the occurring characteristic waves are presented.As acoustic phenomena often play a minor role in such applications,classical exp... Considering droplet phenomena at low Mach numbers,large differences in the magnitude of the occurring characteristic waves are presented.As acoustic phenomena often play a minor role in such applications,classical explicit schemes which resolve these waves suffer from a very restrictive timestep restriction.In this work,a novel scheme based on a specific level set ghost fluid method and an implicit-explicit(IMEX)flux splitting is proposed to overcome this timestep restriction.A fully implicit narrow band around the sharp phase interface is combined with a splitting of the convective and acoustic phenomena away from the interface.In this part of the domain,the IMEX Runge-Kutta time discretization and the high order discontinuous Galerkin spectral element method are applied to achieve high accuracies in the bulk phases.It is shown that for low Mach numbers a significant gain in computational time can be achieved compared to a fully explicit method.Applica-tions to typical droplet dynamic phenomena validate the proposed method and illustrate its capabilities. 展开更多
关键词 IMEX flux splitting Level set method Ghost fluid method Low Mach number flows
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Process Characterization of the Transesterification of Rapeseed Oil to Biodiesel Using Design of Experiments and Infrared Spectroscopy
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作者 Tobias Drieschner Andreas Kandelbauer +1 位作者 Bernd Hitzmann Karsten Rebner 《Journal of Renewable Materials》 SCIE EI 2023年第4期1643-1660,共18页
For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is compulsory.Thus,process analytical technology(PAT)that allows deeper insight into the proc... For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is compulsory.Thus,process analytical technology(PAT)that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process factors can help to achieve higher production efficiency and quality.The present study aims at characterizing a well-known industrial process,the transesterification reaction of rapeseed oil with methanol to produce fatty acid methyl esters(FAME)for usage as biodiesel in a continuous micro reactor set-up.To this end,a design of experiment approach is applied,where the effects of two process factors,the molar ratio and the total flow rate of the reactants,are investigated.The optimized process target response is the FAME mass fraction in the purified nonpolar phase of the product as a measure of reaction yield.The quantification is performed using attenuated total reflection infrared spectroscopy in combination with partial least squares regression.The data retrieved during the conduction of the DoE experimental plan were used for statistical analysis.A non-linear model indicating a synergistic interaction between the studied factors describes the reactor behavior with a high coefficient of determination(R^(2))of 0.9608.Thus,we applied a PAT approach to generate further insight into this established industrial process. 展开更多
关键词 Process analytical technology TRANSESTERIFICATION design of experiment attenuated total reflection infrared spectroscopy partial least square regression
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Impact of COVID-19 lockdown on hospital admissions for epistaxis in Germany
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作者 Adrian Hoenle Martin Wagner +1 位作者 Stephan Lorenz Helmut Steinhart 《World Journal of Methodology》 2023年第5期446-455,共10页
BACKGROUND Reports of a decrease in hospital admissions during the coronavirus disease 2019(COVID-19)lockdown period have raised concerns about delayed or missed diagnoses and treatments for non-COVID-19-related illne... BACKGROUND Reports of a decrease in hospital admissions during the coronavirus disease 2019(COVID-19)lockdown period have raised concerns about delayed or missed diagnoses and treatments for non-COVID-19-related illnesses.AIM To investigate the impact of the COVID-19 pandemic-induced lockdown and its end on hospital admissions of patients with epistaxis in Germany.METHODS A retrospective analysis based on the national database of the Hospital Remuneration System was used to compare hospital admissions during defined time periods between 2019 and 2022 with the lockdown period as the reference period.This was done on a weekly basis before,during,and after the lockdown.An Interrupted Time Series was used as the analysis method.RESULTS In our analysis,we included 26183 patients.The implementation of the lockdown led to a substantial reduction in the overall occurrence of epistaxis among patients(P<0.05).This effect was most pronounced in the age group of 0-39 years,where the decrease was highly significant(P<0.001).However,there was no change observed in patients aged 80 years and older(not significant).With the end of the lockdown period,the overall number of patients,especially in the youngest age group,increased abruptly and significantly(P<0.01).CONCLUSION During the lockdown period,there was a decrease in hospital admissions for younger patients with epistaxis,possibly due to the fear of COVID-19 exposure.We also conclude that the severity of epistaxis was not underestimated in the elderly during the pandemic. 展开更多
关键词 COVID-19 EPISTAXIS Lockdown PANDEMIC Emergency medicine OTOLARYNGOLOGY
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Impact of the Heat Pump on the Environment
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作者 Jovan Mitrović 《Journal of Power and Energy Engineering》 2023年第6期26-33,共8页
The paper deals with the impact of a mechanical compression heat pump, operated by electrical energy, on the environment. Irrespective of its origin and the history of its production, this energy pollutes the environm... The paper deals with the impact of a mechanical compression heat pump, operated by electrical energy, on the environment. Irrespective of its origin and the history of its production, this energy pollutes the environment as waste heat. The operational energy, obtained from the so-called alternative energy sources (wind, water energy), also burdens the environment as waste heat. This is not the case with the solar energy. A direct conversion of the Sun’s rays into electricity does not additionally affect the environment, compared to their direct conversion into heat without our intervention. 展开更多
关键词 Heat Pump ENVIRONMENT
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Recent Advances in Nano‑Enabled Seed Treatment Strategies for Sustainable Agriculture:Challenges,Risk Assessment,and Future Perspectives
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作者 Amruta Shelar Shivraj Hariram Nile +6 位作者 Ajay Vikram Singh Dirk Rothenstein Joachim Bill Jianbo Xiao Manohar Chaskar Guoyin Kai Rajendra Patil 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第4期153-189,共37页
Agro seeds are vulnerable to environmental stressors,adversely affecting seed vigor,crop growth,and crop productivity.Different agrochemical-based seed treatments enhance seed germination,but they can also cause damag... Agro seeds are vulnerable to environmental stressors,adversely affecting seed vigor,crop growth,and crop productivity.Different agrochemical-based seed treatments enhance seed germination,but they can also cause damage to the environment;therefore,sustainable technologies such as nano-based agrochemicals are urgently needed.Nanoagrochemicals can reduce the dose-dependent toxicity of seed treatment,thereby improving seed viability and ensuring the controlled release of nanoagrochemical active ingredients However,the applications of nanoagrochemicals to plants in the field raise concerns about nanomaterial safety,exposure levels,and toxicological implications to the environment and human health.In the present comprehensive review,the development,scope,challenges,and risk assessments of nanoagrochemicals on seed treatment are discussed.Moreover,the implementation obstacles for nanoagrochemicals use in seed treatments,their commercialization potential,and the need for policy regulations to assess possible risks are also discussed.Based on our knowledge,this is the first time that we have presented legendary literature to readers in order to help them gain a deeper understanding of upcoming nanotechnologies that may enable the development of future generation seed treatment agrochemical formulations,their scope,and potential risks associated with seed treatment. 展开更多
关键词 Agro seeds Environmental seed stressors Nanoagrochemicals Toxicological implications Risk regulations
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Soil Moisture Rather than Soil Nutrient Regulates the Belowground Bud Bank of Rhizomatous Species Psammochloa villosa in Arid Sand Dunes
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作者 Yawei Dong Ziyue Guo +6 位作者 Qun Ma Zhiming Xin Jin Tao Jiatai Tian Jinlei Zhu Zhiming Zhang Jianqiang Qian 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第5期1301-1309,共9页
In arid and semi-arid sand dune ecosystems,belowground bud bank plays an important role in population regeneration and vegetation restoration.However,the responses of belowground bud bank size and composition to sand ... In arid and semi-arid sand dune ecosystems,belowground bud bank plays an important role in population regeneration and vegetation restoration.However,the responses of belowground bud bank size and composition to sand burial and its induced changes in soil environmental factors have been rarely studied.In arid sand dunes of Northwestern China,we investigated belowground bud bank size and composition of the typical rhizomatous psammophyte Psammochloa villosa as well as three key soil environmental factors(soil moisture,total carbon and total nitrogen)under different depths of sand burial.Total buds and rhizome buds increased significantly with increasing burial depth,whereas tiller buds first increased and then decreased,with a peak value at the depth of 20-30 cm.Soil moisture increased significantly with sand burial depth,and was positively correlated with the number of all buds and rhizome buds.Soil total carbon concentration first increased and then decreased with sand burial depth,and total nitrogen concentration was significantly lower under deep sand burial than those at shallow depths,and only the number of tiller buds was positively correlated with soil total nitrogen concentration.These results indicate that soil moisture rather than soil nutrient might regulate the belowground bud bank of P.villosa,and that clonal psammophytes could regulate their belowground bud bank in response to sand burial and the most important environmental stress(i.e.,soil moisture).These responses,as the key adaptive strategy,may ensure clonal plant population regeneration and vegetation restoration in arid sand dunes. 展开更多
关键词 Adaptive strategy clonal plant population regeneration PSAMMOPHYTE vegetation restoration
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Changes of the liver metabolome following an intravenous lipopolysaccharide injection in Holstein cows supplemented with dietary carnitine
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作者 Wei Xu Sandra Grindler +3 位作者 Akos Kenez Sven Danicke Jana Frahm Korinna Huber 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第1期188-199,共12页
Background:Carnitine facilitates the flux of long-chain fatty acids for hepatic mitochondrial beta-oxidation,which acts to ameliorate the negative energy balance commonly affecting high-yielding dairy cows.Inflammatio... Background:Carnitine facilitates the flux of long-chain fatty acids for hepatic mitochondrial beta-oxidation,which acts to ameliorate the negative energy balance commonly affecting high-yielding dairy cows.Inflammation triggered by lipopolysaccharide(LPS)load can however pose a challenge to the metabolic integrity via the expression of pro-inflammatory mediators,leading to immune system activation and respective metabolic alterations.The effect of enhanced carnitine availability on hepatic metabolome profiles during an inflammatory challenge has not yet been determined in dairy cows.Herein,Holstein cows were supplemented with 25 g/d rumen-protected carnitine from 42d prepartum until 126 d postpartum(n=16)or assigned to the control group with no supplementation during the same period(n=14).We biopsied the liver of the cows before(100 d postpartum)and after(112 d postpartum)an intravenous injection of 0.5μg/kg LPS.Liver samples were subjected to a targeted metabolomics analysis using the AbsoluteIDQ p180 Kit(Biocrates Life Sciences AG,Innsbruck,Austria).Results:Multivariate statistical analyses revealed that hepatic metabolome profiles changed in relation to both the carnitine supplementation and the LPS challenge.Comparing the metabolite profiles on 100 d,carnitine increased the concentration of short-and long-chain acyl-carnitines,which may be explained by an enhanced mitochondrial fatty acid shuttle and hence greater energy availability.The LPS injection affected hepatic metabolite profiles only in the carnitine supplemented group,particularly altering the concentration of biogenic amines.Conclusions:Our results point to interactions between an acute hepatic inflammatory response and biogenic amine metabolism,depending on energy availability. 展开更多
关键词 Acyl-carnitines Inflammatory response Lipid metabolism Liver metabolome Mitochondrial function
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Combining rhizosphere and soil-based P management decreases the P fertilizer demand of China by more than half based on LePA model simulations
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作者 YU Wen-jia LI Hai-gang +9 位作者 Peteh MNKEBIWE YANG Xue-yun GUO Da-yong LI Cui-lan ZHU Yi-yong XIAO Jing-xiu LI Guo-hua SUN Zhi Torsten MüLLER SHEN Jian-bo 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第8期2509-2520,共12页
Phosphorus(P)is a finite natural resource and is increasingly considered to be a challenge for global sustainability.Agriculture in China plays a key role in global sustainable P management.Rhizosphere and soil-based ... Phosphorus(P)is a finite natural resource and is increasingly considered to be a challenge for global sustainability.Agriculture in China plays a key role in global sustainable P management.Rhizosphere and soil-based P management are necessary for improving P-use efficiency and crop productivity in intensive agriculture in China.A previous study has shown that the future demand for phosphate fertilizer by China estimated by the LePA model(legacy phosphorus assessment model)can be greatly reduced by soil-based P management(the building-up and maintenance approach).The present study used the LePA model to predict the phosphate demand by China through combined rhizosphere and soil-based P management at county scale under four P fertilizer scenarios:(1)same P application rate as in 2012;(2)rate maintained same as 2012 in low-P counties or no P fertilizer applied in high-P counties until targeted soil Olsen-P(TPOlsen)level is reached,and then rate was the same as P-removed at harvest;(3)rate in each county decreased to1–7 kg ha^(-1) yr^(-1) after TPOlsen is reached in low-P counties,then increased by 0.1–9 kg ha^(-1) yr^(-1) until equal to P-removal;(4)rate maintained same as 2012 in low-P counties until TPOlsen is reached and then equaled to P-removal,while the rate in high-P counties is decreased to 1–7 kg ha^(-1) yr^(-1) until TPOlsen is reached and then increased by 0.1–9 kg ha^(-1) yr^(-1)until equal to P-removal.Our predictions showed that the total demand for P fertilizer by whole China was 693 Mt P2O5and according to scenario 4,P fertilizer could be reduced by 57.5%compared with farmer current practice,during the period 2013–2080.The model showed that rhizosphere P management led to a further 8.0%decrease in P fertilizer use compared with soil-based P management.The average soil Olsen-P level in China only needs to be maintained at 17 mg kg^(-1) to achieve high crop yields.Our results provide a firm basis for government to issue-relevant policies for sustainable P management in China. 展开更多
关键词 phosphorus reserves Pmanagement CROP agriculture China modelling
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基于果萼图像的猕猴桃果实夜间识别方法 被引量:15
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作者 傅隆生 孙世鹏 +3 位作者 Vázquez-Arellano Manuel 李石峰 李瑞 崔永杰 《农业工程学报》 EI CAS CSCD 北大核心 2017年第2期199-204,共6页
根据猕猴桃的棚架式栽培方式,提出了一种适用于猕猴桃采摘机器人夜间识别的方法。采用竖直向上获取果实图像的拍摄方式,以果萼为参考点,进行果实的识别,并测试该方法对光照的鲁棒性。试验结果表明:基于果萼能够有效的识别猕猴桃果实,成... 根据猕猴桃的棚架式栽培方式,提出了一种适用于猕猴桃采摘机器人夜间识别的方法。采用竖直向上获取果实图像的拍摄方式,以果萼为参考点,进行果实的识别,并测试该方法对光照的鲁棒性。试验结果表明:基于果萼能够有效的识别猕猴桃果实,成功率达94.3%;未识别和误识别的果实一般出现在5果及5果以上的簇中,原因是果实相互挤压导致的果萼部分不在果实图像的中心区域,以及果实之间的三角区形成暗色封闭区域;光照过小或过大会导致成像模糊或过曝,对正确率有细微影响;识别速度达到了0.5 s/个。因此,基于果萼的猕猴桃果实夜间识别方法在正确识别率和速度上都有很大提升,更接近实际应用。 展开更多
关键词 机器人 图像识别 农作物 猕猴桃 果萼 夜间识别 毗邻果实
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基于近红外高光谱图像的冬枣损伤早期检测 被引量:26
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作者 孙世鹏 彭俊 +3 位作者 李瑞 朱兆龙 Vázquez-Arellano MANUEL 傅隆生 《食品科学》 EI CAS CSCD 北大核心 2017年第2期301-305,共5页
为了对冬枣损伤进行早期检测,采用近红外高光谱图像技术对损伤区域成像。针对高光谱图像波长多的特点,分别采用连续投影算法、相关特征选择算法、一致性(Consistency)算法选择冬枣损伤的特征波长,对提取的特征波长分别应用k-邻近、朴素... 为了对冬枣损伤进行早期检测,采用近红外高光谱图像技术对损伤区域成像。针对高光谱图像波长多的特点,分别采用连续投影算法、相关特征选择算法、一致性(Consistency)算法选择冬枣损伤的特征波长,对提取的特征波长分别应用k-邻近、朴素贝叶斯(naive bayes,NB)、支持向量机(support vector machine,SVM)3种分类方法进行损伤区域识别。结果表明:所有方法选择的一致特征波长在1 353 nm和1 691 nm附近。Consistency算法选择的特征波长在SVM分类器下分类识别正确率达到95.16%,一致特征波长在NB分类器下分类识别正确率达到84.26%,验证了一致波长的有效性,为多光谱成像技术实现在线检测冬枣损伤提供参考依据。 展开更多
关键词 冬枣 高光谱成像 特征波长 轻微损伤 检测
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基于支持向量机的玉米苗期田间杂草光谱识别 被引量:11
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作者 邓巍 张录达 +7 位作者 何雄奎 Mueller J 曾爱军 宋坚利 刘亚佳 周继中 陈吉 王旭 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2009年第7期1906-1910,共5页
田间全面积均匀喷施除草剂不经济,还污染环境,精准喷施除草剂意义重大,其关键是正确识别杂草。用便携式野外光谱仪,在田间测量了玉米、马唐和稗草植株冠层在350~2 500 nm波长范围内的光谱数据,经过数据预处理,数据分析波长选为35... 田间全面积均匀喷施除草剂不经济,还污染环境,精准喷施除草剂意义重大,其关键是正确识别杂草。用便携式野外光谱仪,在田间测量了玉米、马唐和稗草植株冠层在350~2 500 nm波长范围内的光谱数据,经过数据预处理,数据分析波长选为350~1 300和1 400~1 800 nm。数据处理采用支持向量机(SVM)模式识别方法。SVM具有可实现对小样本建模结构风险最小化、结果最优化、泛化能力强的优点。用线性、多项式、径向基和多层感知核函数对玉米和杂草建立二分类模型,结果表明,三阶多项式核函数SVM分类模型的正确识别率最高,达到80%以上,且支持向量比例较小。以二分类模型为基础,利用投票机制,建立了玉米、马唐和稗草的一对一多分类SVM模型,正确识别率达80%。田间光谱测量受光照、背景和仪器测量精度等条件的影响较大,但结果仍表明SVM结合光谱技术在田间杂草识别中应用潜力很大,此研究为田间杂草识别及传感器的建立提供了一种研究思路和应用基础。 展开更多
关键词 光谱 模式识别 支持向量机(SVM) 玉米 杂草
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水稻核心种质表型性状遗传多样性分析及综合评价 被引量:142
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作者 胡标林 万勇 +4 位作者 李霞 雷建国 罗向东 严文贵 谢建坤 《作物学报》 CAS CSCD 北大核心 2012年第5期829-839,共11页
种质资源是水稻遗传育种和解析复杂性状的重要基础,而对遗传多样评估有利于鉴定最优亲本组合,以产生遗传变异最大的后代群体和促进不同资源的有利基因渗透到栽培品种。选用14个表型性状对美国农业部水稻核心种质中的六大洲1579份水稻种... 种质资源是水稻遗传育种和解析复杂性状的重要基础,而对遗传多样评估有利于鉴定最优亲本组合,以产生遗传变异最大的后代群体和促进不同资源的有利基因渗透到栽培品种。选用14个表型性状对美国农业部水稻核心种质中的六大洲1579份水稻种质,分析与评价其遗传多样性和优良稻种资源,主要结果如下:(1)亚洲、非洲与大洋洲种质间遗传距离较远,且亚洲、非洲和大洋洲的水稻资源具有较丰富的表型遗传多样性,而不同性状的遗传多样性在洲际间表现不同;粒长宽比、碱消值、株高、粒宽、千粒重和淀粉含量6个性状具有很高的表型遗传多样性。(2)采用主成分分析法和逐步回归分析法综合评判表明,越南的PI392768的综合性状表现最好,法国的PI281760综合性状表现最差,同时淀粉含量、抽穗期、株高、倒伏性、糙米色和颖壳色6个性状可作为种质资源综合评价指标。在水稻育种中应注重利用具有丰富遗传多样性的种质资源,并在亲本选配时适当选择遗传距离较远且综合性状表现差异大的种质材料。 展开更多
关键词 核心种质 表型性状 遗传多样性 主成分分析 综合评价
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禾谷镰刀菌在小麦穗部侵染过程的细胞学研究 被引量:25
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作者 康振生 黄丽丽 +2 位作者 H.BUCHENAUER 韩青梅 蒋选利 《植物病理学报》 CAS CSCD 北大核心 2004年第4期329-335,共7页
采用扫描和透射电镜技术系统地观察了禾谷镰刀菌 (Fusarium graminearum)在小麦穗部的侵染过程。接种后 6~12h ,分生孢子在小麦穗部的任何部位均可萌发 ,每个孢子可产生 1至多个芽管 ,新产生的芽管并不立即入侵寄主组织 ,而是在寄主体... 采用扫描和透射电镜技术系统地观察了禾谷镰刀菌 (Fusarium graminearum)在小麦穗部的侵染过程。接种后 6~12h ,分生孢子在小麦穗部的任何部位均可萌发 ,每个孢子可产生 1至多个芽管 ,新产生的芽管并不立即入侵寄主组织 ,而是在寄主体表生长扩展 ;接种后 36~ 4 8h观察 ,小穗颖片、外稃、内稃的内侧和子房的表面形成了密集的菌丝网 ,然而在小麦穗轴表面、颖片和内稃的外表面 ,菌丝生长缓慢、分布稀疏 ,但颖片外表边缘的菌丝可跨越边缘扩展到颖片的内表皮上 ;接种后 36h ,寄主体表菌丝产生入侵菌丝 ,以直接入侵方式由颖片、外稃、内稃的内侧及子房的顶部侵入寄主组织体内 ,随后 ,菌丝以胞间和胞内生长的方式向下扩展 ;接种后 4~ 5d ,菌丝由上述组织扩展到达穗轴后 ,在穗轴内沿微管束组织和皮层组织向上和向下扩展 ,延伸到相邻小花 ,随菌丝在小麦穗部组织内不断地生长扩展 ,使得寄主细胞坏死、解体 。 展开更多
关键词 禾谷镰刀菌 小麦 穗部侵染过程 细胞学 赤霉病
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