Negative absorption of an inverse V type which risesfirst and then drops is often observed in the adsorption test of low adsorption samples.In view of this,a gravimetric isotherm rig with a large sample size was introd...Negative absorption of an inverse V type which risesfirst and then drops is often observed in the adsorption test of low adsorption samples.In view of this,a gravimetric isotherm rig with a large sample size was introduced.Its testing principles and operation processes were analyzed based on the previous research results.Then,the volumetric method,magnetic-levitation gravimetric method and large sample size gravimetric method were compared in terms of their advantages and disadvantages.Accordingly,this gravimetric isotherm rig with a large sample size was adopted to perform isotherm adsorption experiments on the low-rank coal samples taken from Well Jimei 2 in the Jiergalangtu sag,Erlian Basin,Inner Mongolia,and shale samples from the Lower Silurian Longmaxi Fm in the southern Sichuan Basin,so as to explore the essential reason for the“negative adsorption”after the effect of a systematical cumulative error is eliminated.And the following research results were obtained.First,when the large sample size gravimetric method is adopted,the phenomenon of“negative adsorption”doesn't occur and the test results of low-rank coal and shale samples are reliable with a highfitting degree(R2>0.99).Second,an electronic sensor error(e.g.electronic balance and P&T sensors),a system cumulative error and an adsorbed phase density error are not the factors leading to the reversal of negative adsorption curves.Third,the void volume error of a sample cell is the essential reason for the negative adsorption.In conclusion,the test accuracy can be improved by introducing the volume correction factor into the isotherm adsorption interpretation algorithm.展开更多
To address the limitation of low harvesting efficiency in intelligent mechanized harvesting in standardized orchards,a negative pressure adsorption apple harvesting robot has been designed and developed.The robot is b...To address the limitation of low harvesting efficiency in intelligent mechanized harvesting in standardized orchards,a negative pressure adsorption apple harvesting robot has been designed and developed.The robot is based on a Cartesian coordinate system and incorporates direct negative pressure adsorption picking combined with multi-stage buffering collection methods.Additionally,the proposed model pipeline integrates YOLOv8 and Segment Anything Model for precise apple picking point localization.Finally,field trials of the apple harvesting robot were conducted in a V-shaped layout apple orchard at Experiment and Demonstration Orchard at Tianping Lake.The experimental results showed an apple recognition rate of 90.54%,an overall harvesting success rate of 83.65%,an average picking efficiency of 4.83 s per fruit,and a damage rate of 13.61%.It demonstrates the potential of the robot in improving the efficiency and reliability of automated apple harvesting.At the same time,the results highlight the need to focus on enhancing the robustness of apple recognition algorithms under varying lighting conditions,and reducing apple damage rates by shortening the transport pipeline and optimizing the structure of the collection device.This study provides a promising solution for addressing global challenges in agricultural automation,offering insights into the future optimization of intelligent harvesting technologies.展开更多
Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy（XRD） and transmissi...Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy（XRD） and transmission electron microscopy（TEM）. The electrooxidation behaviors of ethanol on the Pd/C electrode in alkaline media were investigated using cyclic voltammetry（CV）, chronoamperometry（CA）, electrochemical impedance spectroscopy（EIS） and single cell performance methods. Pd/C electrode for ethanol oxidation showed high electro-catalytic activity and long term stability. However, it is observed that the current density decreases with the increasing of the potential and negative impedance presents in the potential from-0.1 to0.1 V. The decreasing current density and the negative impedance could be due to the adsorbed intermediates species that inhibited the further oxidation of ethanol. Based on the chemical reaction analysis and EIS spectra, equivalent circuits relating to various potential zones have been obtained. These results reveal the dynamic adsorption of intermediates species on Pd surfaces. Significantly, it is clarified that the adsorption behavior begins from the maximum catalysis of electro-catalysis and ends in the formation of the palladium（II） oxide layer on the electrode surface.展开更多
The single thiolated arylethynylene molecule with 9,10-dihydroanthracene core（denoted as TADHA） possesses pronounced negative differential conductance（NDC） behavior at lower bias regime. The adsorption effects of ...The single thiolated arylethynylene molecule with 9,10-dihydroanthracene core（denoted as TADHA） possesses pronounced negative differential conductance（NDC） behavior at lower bias regime. The adsorption effects of F2 molecule on the current and NDC behavior of TADHA molecular junctions are studied by applying non-equilibrium Green＇s formalism combined with density functional theory. The numerical results show that the F2 molecule adsorbed on the benzene ring of TADHA molecule near the electrode can dramatically suppresses the current of TADHA molecular junction. When the F2 molecule adsorbed on the conjugated segment of 9,10-dihydroanthracene core of TADHA molecule, an obviously asymmetric effect on the current curves induces the molecular system showing apparent rectifier behavior. However, the current especially the NDC behavior have been significantly enlarged when F2 addition reacted with triple bond of TADHA molecule.展开更多
基金supported by the National Major Science and Technology Project“Study on the Accumulation Mechanism and Resource Effectiveness of Me dium-and Low-Rank Coalbed Methane”(No.:2016ZX05041-001)Pet roChina Major Science and Technology Project“Study on Resource Potential and Strategic Succession Area of Coalbed Methane”(No.:2017E-1401).
文摘Negative absorption of an inverse V type which risesfirst and then drops is often observed in the adsorption test of low adsorption samples.In view of this,a gravimetric isotherm rig with a large sample size was introduced.Its testing principles and operation processes were analyzed based on the previous research results.Then,the volumetric method,magnetic-levitation gravimetric method and large sample size gravimetric method were compared in terms of their advantages and disadvantages.Accordingly,this gravimetric isotherm rig with a large sample size was adopted to perform isotherm adsorption experiments on the low-rank coal samples taken from Well Jimei 2 in the Jiergalangtu sag,Erlian Basin,Inner Mongolia,and shale samples from the Lower Silurian Longmaxi Fm in the southern Sichuan Basin,so as to explore the essential reason for the“negative adsorption”after the effect of a systematical cumulative error is eliminated.And the following research results were obtained.First,when the large sample size gravimetric method is adopted,the phenomenon of“negative adsorption”doesn't occur and the test results of low-rank coal and shale samples are reliable with a highfitting degree(R2>0.99).Second,an electronic sensor error(e.g.electronic balance and P&T sensors),a system cumulative error and an adsorbed phase density error are not the factors leading to the reversal of negative adsorption curves.Third,the void volume error of a sample cell is the essential reason for the negative adsorption.In conclusion,the test accuracy can be improved by introducing the volume correction factor into the isotherm adsorption interpretation algorithm.
基金supported by China’s Central Guiding Local Technology Development Special Fund Project(Grant No.ZYYD2025CG21)the Zhejiang Science and Technology Plan Project-National Key Research and Development Program of China(Grant No.2019C03075)+1 种基金“Leading Goose”Research and Development Program Subproject of Zhejiang(Grant No.2022C02021)Xinjiang Boshiran Intelligent Agricultural Machinery Co.,Ltd.(Grant No.KYY-HX-20210639).
文摘To address the limitation of low harvesting efficiency in intelligent mechanized harvesting in standardized orchards,a negative pressure adsorption apple harvesting robot has been designed and developed.The robot is based on a Cartesian coordinate system and incorporates direct negative pressure adsorption picking combined with multi-stage buffering collection methods.Additionally,the proposed model pipeline integrates YOLOv8 and Segment Anything Model for precise apple picking point localization.Finally,field trials of the apple harvesting robot were conducted in a V-shaped layout apple orchard at Experiment and Demonstration Orchard at Tianping Lake.The experimental results showed an apple recognition rate of 90.54%,an overall harvesting success rate of 83.65%,an average picking efficiency of 4.83 s per fruit,and a damage rate of 13.61%.It demonstrates the potential of the robot in improving the efficiency and reliability of automated apple harvesting.At the same time,the results highlight the need to focus on enhancing the robustness of apple recognition algorithms under varying lighting conditions,and reducing apple damage rates by shortening the transport pipeline and optimizing the structure of the collection device.This study provides a promising solution for addressing global challenges in agricultural automation,offering insights into the future optimization of intelligent harvesting technologies.
文摘Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy（XRD） and transmission electron microscopy（TEM）. The electrooxidation behaviors of ethanol on the Pd/C electrode in alkaline media were investigated using cyclic voltammetry（CV）, chronoamperometry（CA）, electrochemical impedance spectroscopy（EIS） and single cell performance methods. Pd/C electrode for ethanol oxidation showed high electro-catalytic activity and long term stability. However, it is observed that the current density decreases with the increasing of the potential and negative impedance presents in the potential from-0.1 to0.1 V. The decreasing current density and the negative impedance could be due to the adsorbed intermediates species that inhibited the further oxidation of ethanol. Based on the chemical reaction analysis and EIS spectra, equivalent circuits relating to various potential zones have been obtained. These results reveal the dynamic adsorption of intermediates species on Pd surfaces. Significantly, it is clarified that the adsorption behavior begins from the maximum catalysis of electro-catalysis and ends in the formation of the palladium（II） oxide layer on the electrode surface.
基金Project supported by the National Natural Science Foundation of China(Grant No.11374195)the Taishan Scholar Project of Shandong Province,Chinathe Jinan Youth Science and Technology Star Project,China(Grant No.201406004)
文摘The single thiolated arylethynylene molecule with 9,10-dihydroanthracene core（denoted as TADHA） possesses pronounced negative differential conductance（NDC） behavior at lower bias regime. The adsorption effects of F2 molecule on the current and NDC behavior of TADHA molecular junctions are studied by applying non-equilibrium Green＇s formalism combined with density functional theory. The numerical results show that the F2 molecule adsorbed on the benzene ring of TADHA molecule near the electrode can dramatically suppresses the current of TADHA molecular junction. When the F2 molecule adsorbed on the conjugated segment of 9,10-dihydroanthracene core of TADHA molecule, an obviously asymmetric effect on the current curves induces the molecular system showing apparent rectifier behavior. However, the current especially the NDC behavior have been significantly enlarged when F2 addition reacted with triple bond of TADHA molecule.
