A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long peri...A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was investigated.Moreover,a quantitative relationship between the microstructure and tensile yield strength was established.The results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were broken.In IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute atoms.The severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO phase.After MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% respectively.Grain refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP sample.In particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in IZ.This result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate.展开更多
Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD...Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD)and organic sulfur contents.Even after the recovery of H_(2)S from the sour water by the stripping process,the effluent still contains a high concentration of dissolved organic sulfur(DOS),which can have a huge bad influence.While chemical composition of dissolved organic matter(DOM)in refinery wastewater has been extensively studied,the investigation of recalcitrant DOS from sour waters remains unclear.In the present study,chemical composition of sour water DOMs(especially DOS)was investigated using fluorescence spectroscopy(excitation-emission matrix,EEM)and mass spectrometry,including gas chromatography-mass spectrometry(GC-MS)and high-resolution Orbitrap MS.The GC-MS and EEM results showed that volatile and low-aromaticity compounds were effectively removed during the stripping process,while compounds with high hydrophilicity and humification degree were found to be more recalcitrant.The Orbitrap MS results showed that weak-polar oxygenated sulfur compounds were easier to be removed than oxygenated compounds.However,the effluent still contained significant amounts of sulfur-containing compounds with multiple sulfur atoms,particularly in the form of highly unsaturated and aromatic compounds.The Orbitrap MS/MS results of CHOS-containing compounds from the effluent indicate that the sulfur atoms may exist as sulfonates,disulfide bonds,thioethers.Understanding the composition and structure of sour water DOS is crucial for the development of effective treatment processes that can target polysulfide compounds and minimize their impact on the environment.展开更多
In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.Th...In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.The data collection for this paper includes data on deep processing of Chinese coal products from 2009 to 2020,as well as data on asset structure evolution and financial performance of 34 listed companies in the Chinese coal mining.Entropy value method is used to calculate the entropy value of low-carbon transformation,and the regression analysis is used to study the performance of cleaner transformation,the conclusion is as follows:(1)From 2009 to 2020,in China’s total energy consumption,coal consumption accounted for 71.6%in 2009 and 56.8%in 2020,the goals set by the state have been achieved.(2)The national goal of reducing the proportion of coal consumption and reducing carbon emissions has forced the transformation of deep processing of coal products.The transformation of coal enterprises towards low-carbon and clean production has achieved remarkable results.(3)From 2009 to 2020,the non coal industry income of 34 listed companies in China’s coal mining industry increased by 8.21%annually.At the same time,the asset structure was adjusted,and nearly 80%of the asset structure evolution showed an orderly development trend.(4)The regression analysis results show that the entropy value of coal deep processing products and the entropy value of asset structure adjustment are significantly related to transformation performance.The paper proposes to summarize the successful experience of China’s coal energy economic transformation,lay a foundation for achieving the carbon peak and carbon neutral goals in the future,further increase the intensity of coal deep processing,increase the proportion of clean energy in total energy consumption,and strive to control asset operation towards the goal of increasing the proportion of non coal industry income.展开更多
Phosphorus(P)is an essential nutrient for many organisms in the ocean,which plays a central role in the stability of ecosystems and the evolution of the environment.The distribution,occurrence and source-sink process ...Phosphorus(P)is an essential nutrient for many organisms in the ocean,which plays a central role in the stability of ecosystems and the evolution of the environment.The distribution,occurrence and source-sink process of P in offshore waters are highly influenced by mariculture activities.P transformation in water-sediment system is the key process in P cycling,however,the mechanism is poorly documented in the coastal sea which is influenced by human activities.Based on the comprehensive surveys in the adjacent waters outside Rushan Bay in May,July and August 2014 and February 2015,the form and transformation of P in the suspended particulate matter(SPM)and surface sediment were analyzed.The results showed that contents of total P,authigenic P and organic P of SPM increased with the increase in distance from the shoreline off Rushan Bay,and the detrital-P decreased.The partition coefficient of P between water and SPM was related to the chemical activity of different forms of P,and a higher reactivity of inorganic P associated with SPM was observed.Hypoxia induced by mariculture changes the distribution and morphological composition of P in SPM and sediment in this typical aquaculture area,which can result in a conversion of sink to source of P in the sediment,thereby having a significant impact on the regional nutrient budget and associated with eutrophication.展开更多
Objective:To investigate the effects of Intron on the EMT capability of non-small cell lung cancer cell line PC-9.Methods:Firstly,using the psiCHECK-2 plasmid as a basic framework to construct the recombinant plasmid ...Objective:To investigate the effects of Intron on the EMT capability of non-small cell lung cancer cell line PC-9.Methods:Firstly,using the psiCHECK-2 plasmid as a basic framework to construct the recombinant plasmid of psiCHECK-2-Intron dual-luciferase reporter gene;secondly,the psiCHECK-2-Intron and psiCHECK-2 were transfected into PC-9 cells respectively.The migration and invasion abilities of PC-9 cells were analyzed by Matrigel assay.The expression changes of EMT related hallmarks,including N-cadherin,β-catenin and snail,were detected by qRT-PCR and Western Blotting.Results:Compared with the control group,the migration and invasion abilities of PC-9 cells in Intron group significantly decreased(p<0.001).The expression of N-cadherin,β-catenin and snail also down-regulated(p<0.001).Conclusion:The introns could inhibit the EMT of PC-9 cells.展开更多
Decomposition and reconstruction of Mallat fast wavelet transformation (WT) is described. A fast algorithm, which can greatly decrease the processing burden and can be very easy for hardware implementation in real-t...Decomposition and reconstruction of Mallat fast wavelet transformation (WT) is described. A fast algorithm, which can greatly decrease the processing burden and can be very easy for hardware implementation in real-time, is analyzed. The algorithm will no longer have the processing of decimation and interpolation of usual WT. The formulae of the decomposition and the reconstruction are given. Simulation results of the MEMS (micro-electro mechanical systems) gyroscope drift signal show that the algorithm spends much less processing time to finish the de-noising process than the usual WT. And the de-noising effect is the same. The fast algorithm has been implemented in a TMS320C6713 digital signal processor. The standard variance of the gyroscope static drift signal decreases from 78. 435 5 (°)/h to 36. 763 5 (°)/h. It takes 0. 014 ms to process all input data and can meet the real-time analysis of signal.展开更多
由于水下环境的多样性和光在水中受到的散射及选择性吸收作用,采集到的水下图像通常会产生严重的质量退化问题,如颜色偏差、清晰度低和亮度低等,为解决以上问题,本文提出了一种基于Transformer和生成对抗网络的水下图像增强算法。以生...由于水下环境的多样性和光在水中受到的散射及选择性吸收作用,采集到的水下图像通常会产生严重的质量退化问题,如颜色偏差、清晰度低和亮度低等,为解决以上问题,本文提出了一种基于Transformer和生成对抗网络的水下图像增强算法。以生成对抗网络为基础架构,结合编码解码结构、基于空间自注意力机制的全局特征建模Transformer模块和通道级多尺度特征融合Transformer模块构建了TGAN(generative adversarial network with transformer)网络增强模型,重点关注水下图像衰减更严重的颜色通道和空间区域,有效增强了图像细节并解决了颜色偏差问题。此外,设计了一种结合RGB和LAB颜色空间的多项损失函数,约束网络增强模型的对抗训练。实验结果表明,与CLAHE(contrast limited adaptive histogram equalization)、UDCP(underwater dark channel prior)、UWCNN(underwater based on convolutional neural network)、FUnIE-GAN(fast underwater image enhancement for improved visual perception)等典型水下图像增强算法相比,所提算法增强后的水下图像在清晰度、细节纹理和色彩表现等方面都有所提升,客观评价指标如峰值信噪比、结构相似性和水下图像质量度量的平均值分别提升了5.8%、1.8%和3.6%,有效地提升了水下图像的视觉感知效果。展开更多
State estimation is the precondition and foundation of a bioprocess monitoring and optimal control. However,there are many difficulties in dealing with a non-linear system,such as the instability of process, un-modele...State estimation is the precondition and foundation of a bioprocess monitoring and optimal control. However,there are many difficulties in dealing with a non-linear system,such as the instability of process, un-modeled dynamics,parameter sensitivity,etc.This paper discusses the principles and characteristics of three different approaches,extended Kalman filters,strong tracking filters and unscented transformation based Kalman filters.By introducing the unscented transformation method and a sub-optimal fading factor to correct the prediction error covariance,an improved Kalman filter,unscented transformation based robust Kalman filter,is proposed. The performance of the algorithm is compared with the strong tracking filter and unscented transformation based Kalman filter and illustrated in a typical case study for glutathione fermentation process.The results show that the proposed algorithm presents better accuracy and stability on the state estimation in numerical calculations.展开更多
Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to d...Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to develop original solutions to such challenging technological problems due to their remote,sterile,rapid,and site-selective processing of materials.In this review,recent developments in relevant laser processes are summarized under two separate categories.First,transformative approaches,such as for laser-induced graphene,are introduced.In addition to design optimization and the alteration of a native substrate,the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors,or the sequential addition of functional layers coupled with other electronic elements.In addition,the more conventional laser techniques,such as ablation,sintering,and synthesis,can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new mechanisms.Later,various wearable device components developed through the corresponding laser processes are discussed,with an emphasis on chemical/physical sensors and energy devices.In addition,special attention is given to applications that use multiple laser sources or processes,which lay the foundation for the all-laser fabrication of wearable devices.展开更多
To alleviate the heavy load of massive alarm on operators, alarm threshold in chemical processes was optimized with principal component analysis(PCA) weight and Johnson transformation in this paper. First, few variabl...To alleviate the heavy load of massive alarm on operators, alarm threshold in chemical processes was optimized with principal component analysis(PCA) weight and Johnson transformation in this paper. First, few variables that have high PCA weight factors are chosen as key variables. Given a total alarm frequency to these variables initially, the allowed alarm number for each variable is determined according to their sampling time and weight factors. Their alarm threshold and then control limit percentage are determined successively. The control limit percentage of non-key variables is determined with 3σ method alternatively. Second, raw data are transformed into normal distribution data with Johnson function for all variables before updating their alarm thresholds via inverse transformation of obtained control limit percentage. Alarm thresholds are optimized by iterating this process until the calculated alarm frequency reaches standard level(normally one alarm per minute). Finally,variables and their alarm thresholds are visualized in parallel coordinate to depict their variation trends concisely and clearly. Case studies on a simulated industrial atmospheric-vacuum crude distillation demonstrate that the proposed alarm threshold optimization strategy can effectively reduce false alarm rate in chemical processes.展开更多
The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La 3+ were studied by chemical p hase analysis, X-ray diffraction and infrared spectrometry an...The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La 3+ were studied by chemical p hase analysis, X-ray diffraction and infrared spectrometry analysis. The expe rimental results show that phase transformation reactions of FeCO 3, Fe 2O 3 and BaFe 2O 4, barium hexaferrite and γ-Fe 2O 3 take place in the heat tr eatment of gel. While the doping lanthanide ion replace barium ion, an equivalen t quantity of Fe 3+ are reduced to Fe 2+ to maintain the charge equili brium.展开更多
AIM:To investigate the role of reactive oxygen species(ROS)in epithelial–mesenchymal transition(EMT)and apoptosis of human lens epithelial cells(HLECs).METHODS:Flow cytometry was used to assess ROS production after t...AIM:To investigate the role of reactive oxygen species(ROS)in epithelial–mesenchymal transition(EMT)and apoptosis of human lens epithelial cells(HLECs).METHODS:Flow cytometry was used to assess ROS production after transforming growth factorβ2(TGF-β2)induction.Apoptosis of HLECs after H_(2)O_(2) and TGF-β2 interference with or without ROS scavenger N-acetylcysteine(NAC)were assessed by flow cytometry.The corresponding protein expression levels of the EMT markerα-smooth muscle actin(α-SMA),the extracellular matrix(ECM),marker fibronectin(Fn),and apoptosis-associated proteins were detected by using Western blotting in the presence of an ROS scavenger(NAC).Wound-healing and Transwell assays were used to assess the migration capability of HLECs.RESULTS:TGF-β2 stimulates ROS production within 8h in HLECs.Additionally,TGF-β2 induced HLECs cell apoptosis,EMT/ECM synthesis protein markers expression,and pro-apoptotic proteins production;nonetheless,NAC treatment prevented these responses.Similarly,TGF-β2 promoted HLECs cell migration,whereas NAC inhibited cell migration.We further determined that although ROS initiated apoptosis,it only induced the accumulation of the EMT markerα-SMA protein,but not COL-1 or Fn.CONCLUSION:ROS contribute to TGF-β2-induced EMT/ECM synthesis and cell apoptosis of HLECs;however,ROS alone are not sufficient for EMT/ECM synthesis.展开更多
The transformation process of an m-DOF free-floating robot from one staticstate to a different static state has m degrees of freedom. The proposed approach of thesetransformations utilizes a series of single-DOF trans...The transformation process of an m-DOF free-floating robot from one staticstate to a different static state has m degrees of freedom. The proposed approach of thesetransformations utilizes a series of single-DOF transformation processes as an alternative to them-DOF transformation process. Two static state transformation processes are studied in detail.First, a single-DOF transformation process is established using a newly defined concept, referred toas transformation planning, and the definite integral of conservation of angular momentum. Second,the governing equation of the single-DOF transformation process is established using the dynamicequations of motion of the robot. This allows the joint torques to be computed to effect the statetransformation. Finally, an extension of the single-DOF transformation process is proposed to extendthe application of this proposed transformation methodology to create a transformation net whichallows the reconfiguration of a robot from one state to many other possible states.展开更多
基金supported by the National Key Research and Development Program of China(2021YFB3501002)State Key Program of National Natural Science Foundation of China(5203405)+3 种基金National Natural Science Foundation of China(51974220,52104383)National Key Research and Development Program of China(2021YFB3700902)Key Research and Development Program of Shaanxi Province(2020ZDLGY13-06,2017ZDXM-GY-037)Shaanxi Province National Science Fund for Distinguished Young Scholars(2022JC-24)。
文摘A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was investigated.Moreover,a quantitative relationship between the microstructure and tensile yield strength was established.The results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were broken.In IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute atoms.The severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO phase.After MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% respectively.Grain refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP sample.In particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in IZ.This result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate.
基金supported by the National Natural Science Foundation of China(42003059)State Key Laboratory of Coal Mining and Clean Utilization(2021-CMCU-KF009)the Science Foundation of China University of Petroleum,Beijing(No.2462023YJRC003)。
文摘Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD)and organic sulfur contents.Even after the recovery of H_(2)S from the sour water by the stripping process,the effluent still contains a high concentration of dissolved organic sulfur(DOS),which can have a huge bad influence.While chemical composition of dissolved organic matter(DOM)in refinery wastewater has been extensively studied,the investigation of recalcitrant DOS from sour waters remains unclear.In the present study,chemical composition of sour water DOMs(especially DOS)was investigated using fluorescence spectroscopy(excitation-emission matrix,EEM)and mass spectrometry,including gas chromatography-mass spectrometry(GC-MS)and high-resolution Orbitrap MS.The GC-MS and EEM results showed that volatile and low-aromaticity compounds were effectively removed during the stripping process,while compounds with high hydrophilicity and humification degree were found to be more recalcitrant.The Orbitrap MS results showed that weak-polar oxygenated sulfur compounds were easier to be removed than oxygenated compounds.However,the effluent still contained significant amounts of sulfur-containing compounds with multiple sulfur atoms,particularly in the form of highly unsaturated and aromatic compounds.The Orbitrap MS/MS results of CHOS-containing compounds from the effluent indicate that the sulfur atoms may exist as sulfonates,disulfide bonds,thioethers.Understanding the composition and structure of sour water DOS is crucial for the development of effective treatment processes that can target polysulfide compounds and minimize their impact on the environment.
基金fund major project“Research on China’s Natural Resources Capitalization and Corresponding Market Construction”(No.:15zdb163)Construction project of key disciplines of business administration in Jiangsu Province during the 14th five-year plan(SJYH2022-2/285).
文摘In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.The data collection for this paper includes data on deep processing of Chinese coal products from 2009 to 2020,as well as data on asset structure evolution and financial performance of 34 listed companies in the Chinese coal mining.Entropy value method is used to calculate the entropy value of low-carbon transformation,and the regression analysis is used to study the performance of cleaner transformation,the conclusion is as follows:(1)From 2009 to 2020,in China’s total energy consumption,coal consumption accounted for 71.6%in 2009 and 56.8%in 2020,the goals set by the state have been achieved.(2)The national goal of reducing the proportion of coal consumption and reducing carbon emissions has forced the transformation of deep processing of coal products.The transformation of coal enterprises towards low-carbon and clean production has achieved remarkable results.(3)From 2009 to 2020,the non coal industry income of 34 listed companies in China’s coal mining industry increased by 8.21%annually.At the same time,the asset structure was adjusted,and nearly 80%of the asset structure evolution showed an orderly development trend.(4)The regression analysis results show that the entropy value of coal deep processing products and the entropy value of asset structure adjustment are significantly related to transformation performance.The paper proposes to summarize the successful experience of China’s coal energy economic transformation,lay a foundation for achieving the carbon peak and carbon neutral goals in the future,further increase the intensity of coal deep processing,increase the proportion of clean energy in total energy consumption,and strive to control asset operation towards the goal of increasing the proportion of non coal industry income.
基金The National Natural Science Foundation of China under contract Nos 41806097,42176048 and 42149902.
文摘Phosphorus(P)is an essential nutrient for many organisms in the ocean,which plays a central role in the stability of ecosystems and the evolution of the environment.The distribution,occurrence and source-sink process of P in offshore waters are highly influenced by mariculture activities.P transformation in water-sediment system is the key process in P cycling,however,the mechanism is poorly documented in the coastal sea which is influenced by human activities.Based on the comprehensive surveys in the adjacent waters outside Rushan Bay in May,July and August 2014 and February 2015,the form and transformation of P in the suspended particulate matter(SPM)and surface sediment were analyzed.The results showed that contents of total P,authigenic P and organic P of SPM increased with the increase in distance from the shoreline off Rushan Bay,and the detrital-P decreased.The partition coefficient of P between water and SPM was related to the chemical activity of different forms of P,and a higher reactivity of inorganic P associated with SPM was observed.Hypoxia induced by mariculture changes the distribution and morphological composition of P in SPM and sediment in this typical aquaculture area,which can result in a conversion of sink to source of P in the sediment,thereby having a significant impact on the regional nutrient budget and associated with eutrophication.
基金National Natural Science Foundation of China(No.81660474)。
文摘Objective:To investigate the effects of Intron on the EMT capability of non-small cell lung cancer cell line PC-9.Methods:Firstly,using the psiCHECK-2 plasmid as a basic framework to construct the recombinant plasmid of psiCHECK-2-Intron dual-luciferase reporter gene;secondly,the psiCHECK-2-Intron and psiCHECK-2 were transfected into PC-9 cells respectively.The migration and invasion abilities of PC-9 cells were analyzed by Matrigel assay.The expression changes of EMT related hallmarks,including N-cadherin,β-catenin and snail,were detected by qRT-PCR and Western Blotting.Results:Compared with the control group,the migration and invasion abilities of PC-9 cells in Intron group significantly decreased(p<0.001).The expression of N-cadherin,β-catenin and snail also down-regulated(p<0.001).Conclusion:The introns could inhibit the EMT of PC-9 cells.
基金The National High Technology Research and Devel-opment Program of China (863Program) (No2002AA812038)
文摘Decomposition and reconstruction of Mallat fast wavelet transformation (WT) is described. A fast algorithm, which can greatly decrease the processing burden and can be very easy for hardware implementation in real-time, is analyzed. The algorithm will no longer have the processing of decimation and interpolation of usual WT. The formulae of the decomposition and the reconstruction are given. Simulation results of the MEMS (micro-electro mechanical systems) gyroscope drift signal show that the algorithm spends much less processing time to finish the de-noising process than the usual WT. And the de-noising effect is the same. The fast algorithm has been implemented in a TMS320C6713 digital signal processor. The standard variance of the gyroscope static drift signal decreases from 78. 435 5 (°)/h to 36. 763 5 (°)/h. It takes 0. 014 ms to process all input data and can meet the real-time analysis of signal.
文摘由于水下环境的多样性和光在水中受到的散射及选择性吸收作用,采集到的水下图像通常会产生严重的质量退化问题,如颜色偏差、清晰度低和亮度低等,为解决以上问题,本文提出了一种基于Transformer和生成对抗网络的水下图像增强算法。以生成对抗网络为基础架构,结合编码解码结构、基于空间自注意力机制的全局特征建模Transformer模块和通道级多尺度特征融合Transformer模块构建了TGAN(generative adversarial network with transformer)网络增强模型,重点关注水下图像衰减更严重的颜色通道和空间区域,有效增强了图像细节并解决了颜色偏差问题。此外,设计了一种结合RGB和LAB颜色空间的多项损失函数,约束网络增强模型的对抗训练。实验结果表明,与CLAHE(contrast limited adaptive histogram equalization)、UDCP(underwater dark channel prior)、UWCNN(underwater based on convolutional neural network)、FUnIE-GAN(fast underwater image enhancement for improved visual perception)等典型水下图像增强算法相比,所提算法增强后的水下图像在清晰度、细节纹理和色彩表现等方面都有所提升,客观评价指标如峰值信噪比、结构相似性和水下图像质量度量的平均值分别提升了5.8%、1.8%和3.6%,有效地提升了水下图像的视觉感知效果。
基金Supported by the National Natural Science Foundation of China (20476007, 20676013).
文摘State estimation is the precondition and foundation of a bioprocess monitoring and optimal control. However,there are many difficulties in dealing with a non-linear system,such as the instability of process, un-modeled dynamics,parameter sensitivity,etc.This paper discusses the principles and characteristics of three different approaches,extended Kalman filters,strong tracking filters and unscented transformation based Kalman filters.By introducing the unscented transformation method and a sub-optimal fading factor to correct the prediction error covariance,an improved Kalman filter,unscented transformation based robust Kalman filter,is proposed. The performance of the algorithm is compared with the strong tracking filter and unscented transformation based Kalman filter and illustrated in a typical case study for glutathione fermentation process.The results show that the proposed algorithm presents better accuracy and stability on the state estimation in numerical calculations.
基金supported by the Basic Research Program through the National Research Foundation of Korea(NRF)(Nos.2022R1C1C1006593,2022R1A4A3031263,and RS-2023-00271166)the National Science Foundation(Nos.2054098 and 2213693)+1 种基金the National Natural Science Foundation of China(No.52105593)Zhejiang Provincial Natural Science Foundation of China(No.LDQ24E050001).EH acknowledges a fellowship from the Hyundai Motor Chung Mong-Koo Foundation.
文摘Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to develop original solutions to such challenging technological problems due to their remote,sterile,rapid,and site-selective processing of materials.In this review,recent developments in relevant laser processes are summarized under two separate categories.First,transformative approaches,such as for laser-induced graphene,are introduced.In addition to design optimization and the alteration of a native substrate,the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors,or the sequential addition of functional layers coupled with other electronic elements.In addition,the more conventional laser techniques,such as ablation,sintering,and synthesis,can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new mechanisms.Later,various wearable device components developed through the corresponding laser processes are discussed,with an emphasis on chemical/physical sensors and energy devices.In addition,special attention is given to applications that use multiple laser sources or processes,which lay the foundation for the all-laser fabrication of wearable devices.
基金Supported by the National Natural Science Foundation of China(21576143)
文摘To alleviate the heavy load of massive alarm on operators, alarm threshold in chemical processes was optimized with principal component analysis(PCA) weight and Johnson transformation in this paper. First, few variables that have high PCA weight factors are chosen as key variables. Given a total alarm frequency to these variables initially, the allowed alarm number for each variable is determined according to their sampling time and weight factors. Their alarm threshold and then control limit percentage are determined successively. The control limit percentage of non-key variables is determined with 3σ method alternatively. Second, raw data are transformed into normal distribution data with Johnson function for all variables before updating their alarm thresholds via inverse transformation of obtained control limit percentage. Alarm thresholds are optimized by iterating this process until the calculated alarm frequency reaches standard level(normally one alarm per minute). Finally,variables and their alarm thresholds are visualized in parallel coordinate to depict their variation trends concisely and clearly. Case studies on a simulated industrial atmospheric-vacuum crude distillation demonstrate that the proposed alarm threshold optimization strategy can effectively reduce false alarm rate in chemical processes.
文摘The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La 3+ were studied by chemical p hase analysis, X-ray diffraction and infrared spectrometry analysis. The expe rimental results show that phase transformation reactions of FeCO 3, Fe 2O 3 and BaFe 2O 4, barium hexaferrite and γ-Fe 2O 3 take place in the heat tr eatment of gel. While the doping lanthanide ion replace barium ion, an equivalen t quantity of Fe 3+ are reduced to Fe 2+ to maintain the charge equili brium.
基金Supported by the National Natural Science Foundation of China(No.82201163,No.81800812)Natural Science Foundation Youth Foundation of Shaanxi Province(No.2023-JC-QN-0861)Shaanxi Province Key Research and Development Program(No.2023-YBSF-483).
文摘AIM:To investigate the role of reactive oxygen species(ROS)in epithelial–mesenchymal transition(EMT)and apoptosis of human lens epithelial cells(HLECs).METHODS:Flow cytometry was used to assess ROS production after transforming growth factorβ2(TGF-β2)induction.Apoptosis of HLECs after H_(2)O_(2) and TGF-β2 interference with or without ROS scavenger N-acetylcysteine(NAC)were assessed by flow cytometry.The corresponding protein expression levels of the EMT markerα-smooth muscle actin(α-SMA),the extracellular matrix(ECM),marker fibronectin(Fn),and apoptosis-associated proteins were detected by using Western blotting in the presence of an ROS scavenger(NAC).Wound-healing and Transwell assays were used to assess the migration capability of HLECs.RESULTS:TGF-β2 stimulates ROS production within 8h in HLECs.Additionally,TGF-β2 induced HLECs cell apoptosis,EMT/ECM synthesis protein markers expression,and pro-apoptotic proteins production;nonetheless,NAC treatment prevented these responses.Similarly,TGF-β2 promoted HLECs cell migration,whereas NAC inhibited cell migration.We further determined that although ROS initiated apoptosis,it only induced the accumulation of the EMT markerα-SMA protein,but not COL-1 or Fn.CONCLUSION:ROS contribute to TGF-β2-induced EMT/ECM synthesis and cell apoptosis of HLECs;however,ROS alone are not sufficient for EMT/ECM synthesis.
文摘The transformation process of an m-DOF free-floating robot from one staticstate to a different static state has m degrees of freedom. The proposed approach of thesetransformations utilizes a series of single-DOF transformation processes as an alternative to them-DOF transformation process. Two static state transformation processes are studied in detail.First, a single-DOF transformation process is established using a newly defined concept, referred toas transformation planning, and the definite integral of conservation of angular momentum. Second,the governing equation of the single-DOF transformation process is established using the dynamicequations of motion of the robot. This allows the joint torques to be computed to effect the statetransformation. Finally, an extension of the single-DOF transformation process is proposed to extendthe application of this proposed transformation methodology to create a transformation net whichallows the reconfiguration of a robot from one state to many other possible states.