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Mapping soil organic matter in cultivated land based on multi-year composite images on monthly time scales

Journal of Integrative Agriculture 2024年第4期23卷 1393-1408页

作者： Jie Song Dongsheng Yu Siwei Wang Yanhe Zhao Xin Wang lixia Ma jiangang li State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Agricultural and Rural Bureau of Luanping County Luanping 068250China Chinese Academy of Sciences University Beijing 100049China

Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance *** study proposed a novel approach to predict SOM with high accuracy using multiyear synthetic remote sensing variables on a monthly *** obtained 12 monthly synthetic Sentinel-2 images covering the study area from 2016 to 2021 through the Google Earth Engine(GEE)platform,and reflectance bands and vegetation indices were extracted from these composite *** the random forest(RF),support vector machine(SVM)and gradient boosting regression tree(GBRT)models were tested to investigate the difference in SOM prediction accuracy under different combinations of monthly synthetic *** showed that firstly,all monthly synthetic spectral bands of Sentinel-2 showed a significant correlation with SOM(P<0.05)for the months of January,March,April,October,and ***,in terms of single-monthly composite variables,the prediction accuracy was relatively poor,with the highest R^(2)value of 0.36 being observed in *** monthly synthetic environmental variables were grouped in accordance with the four quarters of the year,the first quarter and the fourth quarter showed good performance,and any combination of three quarters was similar in estimation *** overall best performance was observed when all monthly synthetic variables were incorporated into the ***,among the three models compared,the RF model was consistently more accurate than the SVM and GBRT models,achieving an R^(2)value of *** for band 12 in December,the importance of the remaining bands did not exhibit significant *** research offers a new attempt to map SOM with high accuracy and fine spatial resolution based on monthly synthetic Sentinel-2 images.

关键词： soil organic matter Sentinel-2 monthly synthetic images machine learning model spatial prediction

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Incorporation of source contributions to improve the accuracy of soil heavy metal mapping using small sample sizes at a county scale

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Pedosphere 2024年第1期34卷 170-180页

作者： Jie SONG Xin WANG Dongsheng YU jiangang li Yanhe ZHAO Siwei WANG lixia MA State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Chinese Academy of Sciences University Beijing 100049China Agricultural and Rural Bureau of Luanping County Luanping 068250China

Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to detect the concentrations of eight HMs(As, Hg, Cu, Cr, Ni, Zn, Pb, and Cd) in the herb growing area of Luanping County, northeastern Hebei Province, China. An absolute principal component score-multiple linear regression(APCS-MLR) model was used to quantify pollution source contributions to soil HMs. Furthermore, the source contribution rates and environmental data of each sampling point were simultaneously incorporated into a stepwise linear regression model to identify the crucial indicators for predicting soil HM spatial distributions. Results showed that 88% of Cu, 72% of Cr, and 72% of Ni came from natural sources;50% of Zn, 49% of Pb, and 59% of Cd were mainly caused by agricultural activities;and 44% of As and 56% of Hg originated from industrial activities. When three-type(natural, agricultural, and industrial) source contribution rates and environmental data were simultaneously incorporated into the stepwise linear regression model, the fitting accuracy was significantly improved and the model could explain 31%–86% of the total variance in soil HM concentrations. This study introduced three-type source contributions of each sampling point based on APCS-MLR analysis as new covariates to improve soil HM estimation precision, thus providing a new approach for predicting the spatial distribution of HMs using small sample sizes at the county scale.

关键词： absolute principal component score-multiple linear regression Chinese herbal medicine influencing factors spatial distribution stepwise multiple regression

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Rhizosphere microbes influence wogonoside accumulation in perennial Scutellaria baicalensis

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Pedosphere 2024年第3期34卷 553-566页

作者： Yang SUN Hong liU Junwei PENG Minchong SHEN Yang HU Dongsheng YU jiangang li Yuanhua DONG CAS Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) University of Chinese Academy of Sciences Beijing 100049(China) Tobacco Research Institute of Chinese Academy of Agricultural Sciences Qingdao 266101(China)

Dried roots of Scutellaria baicalensis Georgi are an acclaimed traditional Chinese medicine,and wogonoside content is a key indicator used to evaluate *** *** than rising linearly with cultivation years,*** quality initially increases and then ***,little is known regarding the dynamic variations in *** rhizosphere microorganisms under long-term cultivation and underlying mechanisms of their effects on wogonoside formation and *** aim of this study was to investigate the roles of soil nutrients and rhizosphere microbes on *** quality across different cultivation years(1-4 years).The wogonoside content(25.14 mg g^(-1))was highest in the biennial *** and then decreased following long-term *** soil nutrients(available nitrogen,available phosphorus,available iron,available manganese,and available zinc)were reduced significantly as cultivation years *** also affected rhizosphere bacterial community structure significantly,driving it toward deterministic process(i.e.,β-nearest taxon indexlity under long-term cultivation from the perspective of soil nutrients and microorganisms,which may theoretically support the future artificial cultivation and management of Chinese medicinal plants.

关键词： bacterial diversity medicinal plant rhizosphere bacterial community soil nutrient wogonoside content wogonoside formation

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Plasma current tomography for HL-2A based on Bayesian inference

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Plasma Science and Technology 2024年第5期26卷 165-173页

作者：刘自结王天博吴木泉罗正平王硕孙腾飞肖炳甲李建刚 College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Southwestern Institute for Physics Chengdu 610200People’s Republic of China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China University of Science and Technology of China Hefei 230026People’s Republic of China

An accurate plasma current profile has irreplaceable value for the steady-state operation of the *** this study,plasma current tomography based on Bayesian inference is applied to an HL-2A device and used to reconstruct the plasma current *** different Bayesian probability priors are tried,namely the Conditional Auto Regressive(CAR)prior and the Advanced Squared Exponential(ASE)kernel *** to the CAR prior,the ASE kernel prior adopts nonstationary hyperparameters and introduces the current profile of the reference discharge into the hyperparameters,which can make the shape of the current profile more flexible in *** results indicate that the ASE prior couples more information,reduces the probability of unreasonable solutions,and achieves higher reconstruction accuracy.

关键词： plasma current tomography Bayesian inference machine learning Gaussian distribution

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Magnetic diagnostics layout design for CFETR plasma equilibrium reconstruction

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Chinese Physics B 2024年第4期33卷 537-543页

作者：于庆泽黄耀罗正平汪悦航刘自结芮望颐吴凯肖炳甲李建刚 Institute of Plasma Physics Hefei Institute of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China

Plasma equilibrium reconstruction provides essential information for tokamak operation and physical *** extensive and reliable set of magnetic diagnostics is required to obtain accurate plasma *** study designs and optimizes the magnetic diagnostics layout for the reconstruction of the equilibrium of the plasma according to the scientific objectives,engineering design parameters,and limitations of the Chinese Fusion Engineering Test Reactor(CFETR).Based on the CFETR discharge simulation,magnetic measurement data are employed to reconstruct consistent plasma equilibrium parameters,and magnetic diagnostics'number and position are optimized by truncated Singular value decomposition,verifying the redundancy reliability of the magnetic diagnostics layout *** provides a design solution for the layout of the magnetic diagnostics system required to control the plasma equilibrium of CFETR,and the developed design and optimization method can provide effective support to design magnetic diagnostics systems for future magnetic confinement fusion devices.

关键词： plasma equilibrium reconstruction EFIT code flux loops and magnetic probes optimization

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一种新型登机门开启限速装置的设计

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北京航空航天大学学报 2024年第5期50卷 1532-1540页

作者：智文静李建刚张晨刘冬平杜秀军航空工业集团庆安集团有限公司航空设备研究所西安710077

登机门是民用飞机舱门中的一个重要部件,其直接影响民用客机结构、功能的完整性和安全性。根据项目研制的需要,针对MA600飞机登机门无阻尼式自由下落导致登机门转轴及舱门损坏的问题进行原因分析,设计了一种限制登机门下落速度的新型开... 详细信息

登机门是民用飞机舱门中的一个重要部件,其直接影响民用客机结构、功能的完整性和安全性。根据项目研制的需要,针对MA600飞机登机门无阻尼式自由下落导致登机门转轴及舱门损坏的问题进行原因分析,设计了一种限制登机门下落速度的新型开启限速装置。在CATIA中建立了包括登机门、登机梯、开启限速装置在内的虚拟样机模型,在MSC/ADAMS中对安装和未安装开启限速装置的登机门自由坠落进行动力学仿真分析,分析了产品不同设计参数对登机门自由坠落时间的影响,确定出了最优的结构参数,仿真结果表明:所设计的限速装置能够将登机门的坠落时间限制在6 s,有效减少登机门坠落对门体结构冲击,为后续的样件产出和试验提供理论依据。

关键词：登机门开启限速装置 ADAMS 动力学仿真超速保护

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特大跨径拱桥异形钢箱拱肋畸变翘曲效应影响研究

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市政技术 2024年第6期42卷 125-134页

作者：王磊李健刚四川省公路规划勘察设计研究院有限公司四川成都610041 北京市市政工程设计研究总院有限公司北京100082

针对特大跨径拱桥异形钢箱拱肋畸变翘曲研究成果较少的现状,且为更好地把握空间异形钢箱拱肋的结构受力特性,合理控制截面畸变翘曲效应的影响,以某特大跨径拱桥为例,采用3D Experience simulia软件建立钢箱拱肋有限元模型,对钢箱拱肋截... 详细信息

针对特大跨径拱桥异形钢箱拱肋畸变翘曲研究成果较少的现状,且为更好地把握空间异形钢箱拱肋的结构受力特性,合理控制截面畸变翘曲效应的影响,以某特大跨径拱桥为例,采用3D Experience simulia软件建立钢箱拱肋有限元模型,对钢箱拱肋截面畸变翘曲效应的主要影响因素进行了系统分析。通过分析可知,横隔板的最优间距约为3.0 m、最优开孔率为65%~85%;设置壁板加劲肋对钢箱拱肋的畸变翘曲和局部屈曲约束作用均比较明显;在不影响钢箱拱肋内部检修空间的情况下,设置分仓板对改善截面畸变翘曲作用明显。相关结论为优化调整钢箱拱肋构造提供了一定依据。

关键词：特大跨径拱桥异形钢箱拱肋畸变翘曲有限元分析

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RRM2在结直肠癌的放射增敏中的作用及研究

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激光生物学报 2024年第1期33卷 65-72页

作者：王俊李亮李建刚新疆医科大学第二附属医院普外科乌鲁木齐830063

大多数结直肠癌患者治疗失败的原因是对放射治疗的抵抗。本研究采用生物信息学方法,筛选放疗处理后癌组织中的差异基因(DEGs),寻找与放射敏感性相关的治疗靶点。通过细胞周期调节基因核糖核苷酸还原酶调节亚基M2(RRM2)的表达筛选后,分... 详细信息

大多数结直肠癌患者治疗失败的原因是对放射治疗的抵抗。本研究采用生物信息学方法,筛选放疗处理后癌组织中的差异基因(DEGs),寻找与放射敏感性相关的治疗靶点。通过细胞周期调节基因核糖核苷酸还原酶调节亚基M2(RRM2)的表达筛选后,分别采用lipofectamine 2000和3 Gy放射剂量对细胞进行转染及放疗处理,应用实时荧光定量PCR和蛋白质印迹检测RRM2蛋白在结直肠癌中的表达,采用噻唑兰(MTT)方法测量细胞活力,用流式细胞术测定细胞周期和细胞凋亡。本研究共鉴定出4269个DEGs,其中RRM2基因差异最显著。与肠上皮细胞FHC比较,RRM2在肿瘤细胞中的表达显著升高(P<0.05)。与对照(NC)组比较,过表达RRM2可促进细胞活力。与3 Gy组比较,过表达RRM2能够延缓放疗对细胞的杀伤作用。与NC组比较,过表达RRM2会导致细胞凋亡率降低,而抑制RRM2表达则导致细胞凋亡率升高。与单独使用si-RRM2或辐照相比,si-RRM2和辐照的组合显示出了更好的效果。在细胞周期的分析中,RRM2的过表达导致S期细胞聚集,而RRM2的敲低导致G1期细胞聚集。此外,辐照可导致显著的G1相停滞,而RRM2的敲低与辐照一起可导致更显著的G1相停滞。这表明,RRM2介导了结直肠癌细胞的细胞周期调节,并通过细胞周期影响结直肠癌的放射敏感性。本研究为结直肠癌联合疗法的开展提供了重要的数据支持。

关键词： RRM2 结直肠癌细胞周期放射敏感性治疗靶点

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Calculation of Energetic Ion Tail from Ion Cyclotron Resonance Frequency Heating

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Chinese Physics Letters 1994年第4期11卷 215-218页

作者： WANG Jianguo li Youyi li jiangang Institute of Plasma Physics Academia SinicaHeifei 230031

The second harmonic frequency of hydrogen ion cyclotron resonance heating experiment on HT-6M tokamak was studied by adding the quasi-linear wave-ion interaction term in the two-dimensional(velocity space),time-dependent,nonlinear and multi-species Fokker-Planck *** temporal evolution of ion distribution function and relevant parameters were calculated and compared with experiment *** calculation shows that the ion temperature increases,high-energy ion tail(above 5 keV)and anisotropy appear when the wave is injected to *** simulations are in reasonable agreement with experiment data.

关键词： equation adding anisotropy

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The frontier and perspective for tokamak development

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National Science Review 2019年第3期6卷 382-383页

作者： jiangang li Mingjiu Ni Yu Lu Institute of Plasma Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Bureau of Frontier Sciences and Education Chinese Academy of Sciences

Fusion is an ideal clean energy for human beings in the future. Significant progress has been achieved on tokamak research after successful construction of many large tokamak facilities and many years of experiments, which have established a sound base for tokamak experimental reactors. More than 10 MW fusion power has been produced in the Tokamak Fusion Testing Reactor (TFTR)[1]

关键词： China The frontier and perspective for tokamak development

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