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基于近红外高光谱图像的花生内部霉变快速判别方法研究

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食品安全质量检测学报 2024年第1期15卷 85-91页

作者：朱昊宇王俊杰杨一朱新峰扬州大学信息工程学院扬州225127 北京工商大学食品安全大数据技术北京市重点实验室北京100048

目的针对外观正常但内部存在不同程度霉变的花生,探索采用近红外高光谱成像技术结合机器学习方法构建花生内部霉变快速无损判别模型的可行性。方法采集100粒内部霉变和100粒健康花生的近红外高光谱图像构成数据集,将多种经典光谱预处理... 详细信息

目的针对外观正常但内部存在不同程度霉变的花生,探索采用近红外高光谱成像技术结合机器学习方法构建花生内部霉变快速无损判别模型的可行性。方法采集100粒内部霉变和100粒健康花生的近红外高光谱图像构成数据集,将多种经典光谱预处理方法与支持向量机(support vector machine,SVM)组合建立花生内部霉变判别模型,并采用蒙特卡洛-无信息变量消除法(Monte Carlo-uninformative variable elimination,MC-UVE)找出霉变判别中有效的光谱特征波长。结果将Savitzky-Golay卷积平滑方法和二阶求导光谱预处理方法与SVM组合,对内部霉变严重样本判别的总体识别准确率可达95%,对不同程度内部霉变样本的平均识别准确率为88%;基于MC-UVE筛选得到10、5、3个特征波长构建的模型总体识别准确率为90%、85%和82%。结论实验结果表明高光谱技术结合机器学习可为花生内部霉变的快速、无损判别提供可行的解决方案,同时特征波长筛选为基于光电原理的霉变花生色选机系统开发提供了参考。

关键词：内部霉变花生近红外高光谱支持向量机蒙特卡洛-无信息变量消除法

桔梗特异DNA条形码筛选、种质资源鉴定及遗传多样性分析

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药学学报 2024年第1期59卷 243-252页

作者：王馨石玥满金辉黄钰莹张晓芹安克露何高洁刘子齐关范圆郑语嫣王晓晖魏胜利北京中医药大学中药学院北京102488 北京中医药大学北京中医药研究院中药现代研究中心北京102488 北京中医药大学生命科学院北京102488 黑龙江诺初中药材种植有限公司黑龙江哈尔滨150600

中药材桔梗为桔梗科植物桔梗的干燥根,具有多种药理作用,是常用的大宗中药材。本研究利用Illumina HiSeq X Ten平台对6份来自不同产地的桔梗进行叶绿体基因组测序,筛选特异性DNA条形码,基于特异性DNA条形码对不同产区的桔梗样品的种质... 详细信息

中药材桔梗为桔梗科植物桔梗的干燥根,具有多种药理作用,是常用的大宗中药材。本研究利用Illumina HiSeq X Ten平台对6份来自不同产地的桔梗进行叶绿体基因组测序,筛选特异性DNA条形码,基于特异性DNA条形码对不同产区的桔梗样品的种质资源和遗传多样性进行分析。6份桔梗叶绿体基因组全长为172260~172275 bp,均呈现典型的环状四分体结构,编码141个基因。根据比较基因组学分析和扩增效率分析发现trnG-UCC和ndhG_ndhF可作为潜在的桔梗种内种质资源鉴定的特异性DNA条形码。对来自9省15个产地305份桔梗样品的trnG-UCC和ndhG_ndhF进行PCR扩增和序列分析,结果表明trnG-UCC和ndhG_ndhF分别有5和11个变异位点,分别鉴定到5和7个单倍型;两段序列联合分析鉴定13个单倍型(Hap1~Hap13),其中占比最多的是Hap4,其次是Hap1。3个产地拥有的特异单倍型,可作为该产地的DNA分子标签与其他产地的桔梗种质资源进行区分。单倍型多样性、核苷酸多样性和遗传距离分别为0.94、4.79×10^(-3)和0.0000~0.0203,表明桔梗在物种水平上有较高的遗传多样性,种内各单倍型之间亲缘关系比较接近。本研究为桔梗产地鉴定、种质资源保护利用和分子育种等工作奠定基础。

关键词：桔梗叶绿体基因组 DNA条形码种质资源遗传多样性

Study on the Application of Vibration Isolation by Using a Trench in Frame Structures

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Structural Durability & Health Monitoring 2023年第1期17卷 23-36页

作者： Pinwu Guan Zheng Ma Pu Zhang Shizhan Xu Wei Liu Yanwei Guo Xin Yang Zhen wang Haibo wang Chao Yuan jie wang Zhengzhou University Zhengzhou450002China Henan Xixi Expressway Construction Co. Ltd.Nanyang450015China

An isolation trench is a simple and effective method to isolate structural vibrations originating from sources of vibration other than earthquakes(machines,traffic,explosions,etc.);however,there is still not a conclusive depth of the isolation trench for frame structures.To investigate the isolation effect of a trench in the frame structure designed for ground vibration,both a field test and finite element analysis were conducted to analyze the reduced effect of the vibration.The vibration reduction analysis was based on the dynamic equation and wave theory.Considering the vibration control of an industrial plant frame,a soil-trench-building finite element model was built to analyze the vibration characteristics of the floor before and after the open isolation trench structure was used.According to the model,a dynamic test was carried out on the frame structure to assess the effect of the vibration reduction by introducing the trench.The results showed that the depth of the trench was the dominating factor in vibration isolation.When the depth of the trench reached 1~1.3 times the wavelength of the Rayleigh wave,the damping effect was the strongest.the width of the trench has little effect on the vibration isolation efficiency,and the trench must be maintained at a certain distance from the building to ensure the vibration damping efficiency.The vibration of each floor was obviously reduced after the trench was built.The vibration damping effect of the trench was significant.

关键词： Vibration reduction trench finite element process analysis

Molecular Insights into the Structure-Activity Relationship in Cobalt Porphyrin Catalyzed Oxygen Reduction Reaction

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CCS Chemistry 2023年第11期5卷 2628-2637页

作者： Xiang wang Ya-Chen Feng Yu-Qi wang Zhen-Yu Yi Jun-jie Duan Hui-Juan Yan Dong wang Li-Jun Wan CAS Key Laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Science(BNLMS)Institute of ChemistryChinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049

We present a microscopic investigation on the structure-activity relationship of the Co-N4 site in the oxygen reduction reaction(ORR)by electrochemical scanning tunneling microscopy(ECSTM)at the molecular scale.The cobalt porphyrins with various substituents(CoTPPX_(4),X=Cl,H,OCH_(3))that delicately regulate the electronic structure of the active site were investigatedasmodel catalysts.Electrochemical measurements evidenced that the CoTPPCl_(4)exhibits better activity,higher product selectivity for H_(2)O,and lower stability.The CoTPPX_(4)-O_(2)complex with higher contrast can be observed in the STM images and the proportion of the CoTPPCl_(4)-O_(2)is appreciably larger than that of CoTPP-O_(2)and CoTPP(OCH_(3))4-O_(2).Theoretical simulations of the model catalysts and the reaction processes of the ORR reveal the relationship between the electronic structure and the catalytic behavior of the model catalysts.The transformation of the CoTPPX_(4)-O_(2)and CoTPPX_(4)in the electrocatalytic reaction was monitored by in situ ECSTM characterization.The structure-activity relationship clarified by experimental and theoretical investigations in this work should help to guide the rational design and optimization of high-performance catalysts.

关键词： cobalt porphyrin oxygen reduction reaction electrochemical scanning tunneling microscope structure-activity relationship model catalyst

Improvement in Resolution of Multiphoton Scanning Structured Illumination Microscopy via Harmonics

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Engineering 2022年第9期16卷 65-72页

作者： Lei wang Xiaomin Zheng jie Zhou Meiting wang Jiajie Chen Youjun Zeng Gaixia Xu Ying wang Haixia Qiu Yonghong Shao Junle Qu Bruce Zhi Gao Ying Gu College of Physics and Optoelectronic Engineering Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceShenzhen UniversityShenzhen 518060China Department of Laser Medicine First Medical Center of PLA General HospitalBeijing 100853China Department of Bioengineering and COMSET Clemson UniversityClemsonSC 29634USA

We describe a multiphoton(mP)-structured illumination microscopy(SIM)technique,which demonstrates substantial improvement in image resolution compared with linear SIM due to the nonlinear response of fluorescence.This nonlinear response is caused by the effect of nonsinusoidal structured illumination created by scanning a sinusoidally modulated illumination to excite an mP fluorescence signal.The harmonics of the structured fluorescence illumination are utilised to improve resolution.We present an mP-SIM theory for reconstructing the super-resolution image of the system.Theoretically,the resolution of our m P-SIM is unlimited if all the high-order harmonics of the nonlinear response of fluorescence are considered.Experimentally,we demonstrate an 86 nm lateral resolution for two-photon(2P)-SIM and a 72 nm lateral resolution for second-harmonic-generation(SHG)-SIM.We further demonstrate their application by imaging cells stained with F-actin and collagen fibres in mouse-tail tendon.Our method can be directly used in commercial mP microscopes and requires no specific fluorophores or high-intensity laser.

关键词： Super-resolution microscopy Structured illumination microscopy Multiphoton-structured illumination microscopy(SIM) SIM Second-harmonic-generation(SHG)-SIM

The reversal of surface air temperature anomalies in China between early and late winter 2021/2022:Observations and predictions

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Advances in Climate Change Research 2023年第5期14卷 660-670页

作者： Chong-Bo ZHAO Qing-Quan LI Yu NIE Fang wang Bing XIE Li-Li DONG jie WU China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CenterBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China

During winter of 2021/2022,the temperature in China is characterized by a warm-to-cold transition,and the average temperature anomaly in February 2022 is−1.6℃,the coldest February in 2013-2022.We revealed the circulation regimes and physical mechanisms associated with this reversal event and demonstrated the advantage of a regional model downscaling over the use of the global model alone in predicting.In early winter,the warm anomalies are mainly related to an anomalous anticyclonic system downstream of a PNA-like(Pacific-North America)Rossby-wave train induced by La Niña.In late winter,due to the circulation response to the central Pacific warming and negative tropical Indian Ocean Dipole(TIOD),two‘−+−’Rossby-wave trains from high latitudes and the tropical Indian Ocean jointly lead to an anomalous cyclonic system in China.Meanwhile,an anticyclonic blocking system on the northern side of Baikal brings strong and cold air to China.These two systems together cause a significant drop in surface air temperature anomaly in China during the late winter.The Beijing Climate Center climate system model(BCC_CSM1.1 m)can essentially predict this temperature reversal in China about five months in advance.However,the reversal amplitude is weaker due to warm deviations over the tropical Pacific Ocean and equatorial Indian Ocean.Using dynamic downscaling,a regional Climate-Weather Research and Forecasting(CWRF)model correctly predicts the cold SAT anomalies in late winter 2021/2022.The regional model depicts more realistic circulation patterns in East Asia;the anomalous cyclonic system in Inner Mongolia accompanied by the northerly anomalies contribute to a lower-than-normal SAT over China.This study reveals the cooperative effect of wave trains from high latitudes and the tropics on the subseasonal temperature reversal and demonstrates a possible solution to improve the forecast skill by dynamic downscaling according to precise characterization of local surface information.

关键词： 2021/2022 winter Dynamical downscaling prediction CWRF BCC_CSM1.1 m Reversal of SAT anomalies

Multiscale evolution mechanism of sandstone under wet-dry cycles of deionized water:From molecular scale to macroscopic scale

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1171-1185页

作者： jie Meng Changdong Li Jia-Qing Zhou Zihan Zhang Shengyi Yan Yahui Zhang Dewei Huang Guihua wang Faculty of Engineering China University of GeosciencesWuhan430074China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan430074China

Water is the most abundant molecule found on the earth’s surface and is a key factor in multiscale rock destruction.However,given the fine-grained nature of rock and the complexity of its internal structure,the microstructural evolution of rock under the action of water has not yet been elucidated in detail,and little is understood about the relationship between the rock structure and solideliquid unit.A variety of techniques were used in this study to track the mechanical properties,pore and crack characteristics,and mineral structure degradation characteristics of sandstone at different stages under the action of deionized water,and the evolution mechanisms of the microstructure were analyzed at the molecular scale.The results showed that during the watererock interaction process,water was adsorbed onto the surface of dolomite minerals and the hydrophilic surface of clay minerals,forming a high-density hydrogen bond network.However,different mineral surface structures had different water adsorption structures,resulting in the strain of the dense clay mineral aggregates under expansion action.Stress concentrated at crack tips under the capillary force of dolomite minerals(very weak dolomite dissolution).These effects resulted in a substantial increase in the number of small pores and enhancements in poreecrack connectivity,and the rock strength exhibited varying degrees of decline at different stages of wet-dry cycles.In general,the results of this paper will help to further elucidate the internal connections between molecular-scale and macroscale processes in rock science.

关键词： Rock structure Watererock interaction Multiscale evolution Adsorption structure Hydrogen bond

Intermolecular interactions induced property improvement for clean fracturing fluid by deep eutectic solvents

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Petroleum Science 2023年第6期20卷 3540-3552页

作者： Xiang-Yu wang Ming-Wei Zhao Xu-Hao wang Peng Liu Meng-Yao Fan Teng Li Zhen-Feng Ma Ying-jie Dai Cai-Li Dai Key Laboratory of Unconventional Oil&Gas Development China University of PetroleumQingdao266580ShandongPR China Shandong Key Laboratory of Oilfield Chemistry China University of PetroleumQingdao266580ShandongPR China Dongxin Oil Production Plant Ying First Management Zone of Sinopec Shengli Oilfield Company Dongying257002ShandongPR China

Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.

关键词： Deep eutectic solvents(DESs) Clean fracturing fluids(CFFs) Intermolecular interactions Property improvement

单轴燃气-蒸汽联合循环机组FCB控制策略研究与应用

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工业加热 2024年第1期53卷 24-28页

作者：王永宏唐爽江彬吴占元李杰陈志刚王林大唐万宁天然气发电有限责任公司海南南万宁571500 东莞深能源樟洋电力有限公司陕西西安710054 西安热工研究院有限公司陕西西安710054

为强化本地支撑电源建设,提高应对突发因素造成的大面积停电事故,广东电网对联合循环机组孤网运行能力及“黑启动”功能提出了明确要求。依托某燃机电厂二期基建调试项目,开展了两套AE94.3A型燃气-蒸汽联合循环“一拖一”单轴式机组快... 详细信息

为强化本地支撑电源建设,提高应对突发因素造成的大面积停电事故,广东电网对联合循环机组孤网运行能力及“黑启动”功能提出了明确要求。依托某燃机电厂二期基建调试项目,开展了两套AE94.3A型燃气-蒸汽联合循环“一拖一”单轴式机组快速甩负荷(fast cut back,简称FCB)试验。试验模拟了电网外送回路故障,机组通过快切线路断路器,最终实现了汽机跳闸,燃机快速切负荷、输出功率降至带厂用电的“孤网运行”目的,试验过程各参数变化平稳,主辅机设备均为安全停运,试验取得了较好的效果。通过对汽机旁路系统、锅炉过热/再热减温水系统、汽包液位系统、凝结水及真空系统、轴封系统等的控制策略进行针对性的优化与完善,使得机组具备了完整可靠的FCB功能,显著增强了电源侧供电可靠性。相关经验可供后续同类机组参考。

关键词：燃气蒸汽联合循环机组 FCB 孤网运行热控控制策略