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Mapping upland crop–rice cropping systems for targeted sustainable intensification in South China

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The Crop Journal 2024年第2期12卷 614-629页

作者： Bingwen Qiu Linhai Yu Peng yang Wenbin Wu jianfeng Chen Xiaolin Zhu Mingjie Duan Key Laboratory of Spatial Data Mining&Information Sharing of Ministry of Education Academy of Digital China(Fujian)Fuzhou UniversityFuzhou 350116FujianChina Key Laboratory of Agricultural Remote Sensing Ministry of Agriculture and Rural AffairsBeijing 100081China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina

Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural *** UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural ***,datasets describing cropping systems are limited in spatial coverage and crop *** UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples,which limits its applications over large *** describe a novel algorithm(RRSS)for automatic mapping of upland crop-rice cropping systems using Sentinel-1 Synthetic Aperture Radar(SAR)and Sentinel-2 Multispectral Instrument(MSI)*** indicator,the VV backscatter range,was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed *** RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic *** study developed 10-m UCR maps of a major rice bowl in South China,the Xiang-Gan-Min(XGM)*** performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites,with an overall accuracy of 91.92%.There were7348 km^(2) areas of UCR,roughly one-half of them located in *** UCR was represented mainly by oilseed-UCR and tobacco-UCR,which contributed respectively 69%and 15%of UCR *** patterns accounted for only one-tenth of rice production,which can be tripled by intensification from single rice *** to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm,which could be further applied to generate 10-m UCR datasets for application at national or global scales.

关键词： Cropping-pattern mapping Paddy rice Sentinel-1/2 China Sustainable intensification

Prognostic value of time-varying dead space estimates in mechanically ventilated patients with acute respiratory distress syndrome

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Journal of Intensive Medicine 2024年第2期4卷 187-193页

作者： Lianlian Jiang Hui Chen jianfeng Xie Ling Liu Yi yang Jiangsu Provincial Key Laboratory of Critical Care Medicine Department of Critical Care MedicineZhongda HospitalSchool of MedicineSoutheast UniversityNanjingJiangsuChina Department of Critical Care Medicine The First Affiliated Hospital of Soochow UniversitySoochow UniversitySuzhouJiangsuChina

Background The dead space fraction(VD/VT)has proven to be a powerful predictor of higher mortality in acute respiratory distress syndrome(ARDS).However,its measurement relies on expired carbon dioxide,limiting its widespread application in clinical *** estimates employing routine variables have been found to be reliable substitutes for direct measurement of VD/*** this study,we evaluated the prognostic value of these dead space estimates obtained in the first 7 days following the initiation of *** This retrospective observational study was conducted using data from the Chinese database in intensive care(CDIC).Eligible participants were adult ARDS patients receiving invasive mechanical ventilation while in the intensive care unit between 1st January 2014 and 31st March *** collected data during the first 7 days of ventilation to calculate various dead space estimates,including ventilatory ratio(VR),corrected minute ventilation(V_(Ecorr)),VD/VT(Harris–Benedict),VD/VT(Siddiki estimate),and VD/VT(Penn State estimate)longitudinally.A time-dependent Cox model was used to handle these time-varying *** A total of 392 patients(median age 66[interquartile range:55–77]years,median SOFA score 9[interquartile range:7–12])were finally included in our analysis,among whom 132(33.7%)patients died within 28 days of ***(hazard ratio[HR]=1.04 per 0.1 increase,95%confidence interval[CI]:1.01 to 1.06;P=0.013),V_(Ecorr)(HR=1.08 per 1 increase,95%CI:1.04 to 1.12;P1.3,V_(Ecorr)>7.53,a

关键词： Acute respiratory distress syndr ome Mechanical ventilation Dead space 28-day mortality

Indication from finite-frequency tomography beneath the North China Craton： The heterogeneity of craton destruction

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Science China Earth Sciences 2018年第9期61卷 1238-1260页

作者： Xiaobing XU Liang ZHAO Kun WANG jianfeng yang State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101 China

We picked new traveltime residual datasets in three frequency bands(0.02–0.1, 0.1–0.8, and 0.8–2.0 Hz) for P-waves from 793 teleseismic events and two frequency bands(0.02–0.1 and 0.1–0.8 Hz) for S-waves from 310 teleseismic events,recorded by 389 permanent stations of the China National Seismic Network and 832 broadband stations of 10 temporary arrays deployed in the North China Craton(NCC) region. The final datasets are composed of 65628 P-arrivals and 47050 *** on previous research and our team's 2012 tomographic work, we constructed new three-dimensional P-velocity and Svelocity models of the NCC through some improvements, such as augmenting a much denser station coverage in the western NCC, considering the incident angle effect in crustal correction and using a multi-frequency joint inversion tomographic technique. The new velocity models provide several salient features, from which we draw possible inferences on regional dynamic processes. We observed high-velocity anomalies in the mantle transition zone(MTZ). Obvious morphological heterogeneities suggest buckling and/or fragmentation of the subducted Pacific slab, and some of the slab materials are visible below 660-km discontinuities. The velocity structure of the eastern NCC is dominated by small-scale lateral heterogeneities. At shallow depths, high-velocity anomalies beneath the southern part of the eastern NCC and the Yanshan region likely represent a remnant of cratonic lithosphere, which may suggest that the NCC destruction is spatially non-uniform. We also detected a highvelocity anomaly in the Sulu Orogen extending downward to ~300 km, which is seemingly controlled by the Tan-Lu Fault. The northern boundary of this anomaly spatially coincides with the Yantai-Qingdao-Wulian Fault, and is likely a remnant of the yangtze cratonic lithosphere subducting northwestward. Significant low-velocity anomalies imaged beneath the central NCC show a spatial discordance between their northern and south

关键词：有限频率断层摄影术中国异质北方空间关联速度模型高速度

基于四焦距相位相干机器视觉的晶体微缺陷检测

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电子器件 2024年第3期47卷 743-748页

作者：朱涛黄玉玲陶昕辰张泽宇朱厚森陈王宇羊箭锋杨勇吴迪苏州大学光电科学与工程学院江苏苏州215006

针对目前在晶体内部微缺陷研究上的检测精度较低、检测尺度不足的问题,提出了一种基于四焦距相位相干机器视觉的晶体内部微缺陷检测法,并建立了相应的检测系统。本方法通过四焦距相位相干光路,将晶体内部缺陷的相位信息转化为灰度信息,... 详细信息

针对目前在晶体内部微缺陷研究上的检测精度较低、检测尺度不足的问题,提出了一种基于四焦距相位相干机器视觉的晶体内部微缺陷检测法,并建立了相应的检测系统。本方法通过四焦距相位相干光路,将晶体内部缺陷的相位信息转化为灰度信息,形成晶体内部缺陷特征图像。利用机器视觉算法,提取缺陷特征图像中的相位信息丢失点,并通过滤波算法对这些点进行恢复。然后通过特征提取、灰度分析算法,对缺陷特征图像进行处理分析,最后得出晶体内部缺陷的厚度,完成对晶体内部微缺陷的检测。实验结果表明,利用该方法对有机玻璃表面中心镀60 nm的二氧化硅膜的模拟相位缺陷进行检测,相对误差为1.83%,检测分辨率达到纳米量级。相对于动态泰曼干涉仪检测的2.4%的相对误差以及激光聚焦线扫描法的40μm检测分辨率,有着较大的提升,也证明所提出的方法能够有效运用于晶体内部的微缺陷的检测。

关键词：图像处理相位相干机器视觉晶体缺陷检测

弹力带抗阻训练对脑卒中下肢运动功能障碍患者肌力水平和运动耐力的影响

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中国实用神经疾病杂志 2024年第5期27卷 611-615页

作者：李民丰谢华李爱杨剑峰杜文文史荣芬张超南京市江宁医院江苏南京211100

目的探讨弹力带抗阻训练对脑卒中下肢运动功能障碍患者肌力水平、运动耐力的影响。方法选择2021-06—2022-12在南京市江宁医院接受治疗的80例脑卒中下肢运动功能障碍患者进行研究,采用随机数表法分为试验组(n=40)和对照组(n=40)。对... 详细信息

目的探讨弹力带抗阻训练对脑卒中下肢运动功能障碍患者肌力水平、运动耐力的影响。方法选择2021-06—2022-12在南京市江宁医院接受治疗的80例脑卒中下肢运动功能障碍患者进行研究,采用随机数表法分为试验组(n=40)和对照组(n=40)。对照组给常规运动指导治疗,试验组加用弹力带抗阻训练治疗。比较2组临床疗效、肌力水平、峰值摄氧量(VO_(2)peak)、无氧阈值(AT)、6 min步行距离、步态参数及Barthel指数、平衡功能评分变化情况。结果治疗后,试验组总有效率85%,高于对照组的65%,差异有统计学意义(P<0.05);试验组下肢肌力评分低于对照组[(1.40±0.23)分比(1.98±0.63)分],Fugl Meyer运动量表评分高于对照组[(29.87±3.58)分比(24.15±3.74)分],差异均有统计学意义(P<0.05);试验组VO_(2)peak、AT及6 min步行距离分别为(20.42±1.71)m L/(min·kg)、(13.89±1.01)mL/(min·kg)、(140.56±23.78)m,均高于对照组的(18.46±1.23)m L/(min·kg)、(13.02±1.21)mL/(min·kg)、(116.58±29.61)m,差异均有统计学意义(P<0.05);试验组步长、步速、步频及单支撑相水平分别为(36.87±4.71)cm、(57.78±7.23)cm/s、(69.31±5.41)step/s、(31.05±3.01)%,均高于对照组的(31.52±3.67)cm、(52.84±6.09)cm/s、(63.05±6.08)step/s、(27.21±3.08)%,差异均有统计学意义(P<0.05);试验组Barthel指数、平衡功能评分分别为(78.61±5.61)分、(41.15±2.31)分,均高于对照组的(67.59±6.13)分、(32.56±5.47)分,差异均有统计学意义(P<0.05)。结论在脑卒中下肢运动功能障碍患者中弹力带抗阻训练治疗有较好的效果,可有效改善肌力水平、运动耐力水平。

关键词：脑卒中弹力带抗阻训练下肢运动功能障碍肌力水平运动耐力

Heterogeneous destruction of the North China Craton： Coupled constraints from seismology and geodynamic numerical modeling

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Science China Earth Sciences 2018年第5期61卷 515-526页

作者： Kun WANG Liang ZHAO Xiaobing XU jianfeng yang State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institutions of Earth Science Chinese Academy of Sciences Beijing 100029 China

The prevailing academic view regards mantle flow and the metasomatism triggered by the subduction of the Pacific plate as the cause and mechanism for the destruction of the North China Craton(NCC). However, the geodynamic destruction process remains ambiguous, necessitating detailed information at this stage. Combining the structural images obtained by the exploration of dense seismic arrays and the geodynamic simulations inspired by numerical modeling, this paper arrives at the following conclusions: the spatial variation of the P-and S-wave velocities, as well as their velocity ratio in the mantle transition zone, are key evidences of the nonuniform dehydration of the Pacific plate, the subducted plate induces hot upwellings in the mantle transition zone(MTZ), resulting in the heterogeneous distribution of the melt/fluid beneath the craton, characterized by small scale anomalies in the seismic velocity field, and as revealed by dense seismic array observation, the heterogeneities in the upper mantle structure and deformation are the synthetic results of lithospheric strain localization and the heterogeneous distribution of the melt/fluid. It is known that the nonuniform dehydration of the Pacific slab and the heterogeneous distribution of the melt/fluid have occured in the Cenozoic. If these scenarios could have already occurred in the Early Cretaceous, their interaction with the NCC lithosphere would be the dynamic mechanism for the heterogeneous lithospheric destruction of the NCC. The inference in this study is significant for further reconciling the multidisciplinary evidences in the NCC.

关键词：数字建模地震学异构中国北方地震速度交代作用破坏过程

SOLVING SYSTEMS OF PHASELESS EQUATIONS VIA RIEMANNIAN OPTIMIZATION WITH OPTIMAL SAMPLING COMPLEXITY

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Journal of Computational Mathematics 2024年第3期42卷 755-783页

作者： jianfeng Cai Ke Wei Department of Mathematics Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina School of Data Science Fudan UniversityShanghaiChina

A Riemannian gradient descent algorithm and a truncated variant are presented to solve systems of phaseless equations|Ax|^(2)=*** algorithms are developed by exploiting the inherent low rank structure of the problem based on the embedded manifold of rank-1 positive semidefinite *** recovery guarantee has been established for the truncated variant,showing that the algorithm is able to achieve successful recovery when the number of equations is proportional to the number of *** key ingredients in the analysis are the restricted well conditioned property and the restricted weak correlation property of the associated truncated linear *** evaluations show that our algorithms are competitive with other state-of-the-art first order nonconvex approaches with provable guarantees.

关键词： Phaseless equations Riemannian gradient descent Manifold of rank-1 and positive semidefinite matrices Optimal sampling complexity

Limit state analysis of rigid retaining structures against seismically induced passive failure in heterogeneous soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1095-1105页

作者： jianfeng Zhou Changbing Qin College of Civil Engineering Huaqiao UniversityXiamen362021China School of Civil Engineering Chongqing UniversityChongqing400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing400045China

Soils are not necessarily uniform and may present linearly varied or layered characteristics,for example the backfilled soils behind rigid retaining *** the presence of large lateral thrust imposed by arch bridge,passive soil failure is possible.A reliable prediction of passive earth pressure for the design of such wall is challenging in complicated soil strata,when adopting the conventional limit analysis *** order to overcome the challenge for generating a kinematically admissible velocity field and a statically allowable stress field,finite element method is incorporated into limit analysis,forming finiteelement upper-bound(FEUB)and finite-element lower-bound(FELB)***-static,original and modified pseudo-dynamic approaches are adopted to represent seismic acceleration *** generating feasible velocity and stress fields within discretized elements based on specific criteria,FEUB and FELB formulations of seismic passive earth pressure(coefficient K_(P))can be derived from work rate balance equation and stress *** to an interior point algorithm,optimal upper and lower bound solutions are *** proposed FEUB and FELB procedures are well validated by limit equilibrium as well as lower-bound and kinematic *** studies are carried out to investigate the effects of influential factors on seismic K_(P).Notably,true solution of K_(P) is well estimated based on less than 5%difference between FEUB and FELB solutions under such complex scenarios.

关键词： Retaining wall Passive earth pressure Earthquakes Finite-element limit-analysis methods

Microstructure and properties of Si_3N_4 ceramics obtained from addition of β-phase seeds and celsian

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Journal of University of Science and Technology Beijing 2006年第5期13卷 465-468页

作者： Jun yang Jiqiang Gao jianfeng yang Guanjun Qiao Yonghong Luo State Key Laboratory for Mechanical Behavior of Materials Xi＇an Jiaotong University Xi＇an 710049 China Xi＇an University of Architecture and Technology Xi＇an 710055 China

The silicon nitride based ceramics obtained by the addition of β-Si3N4 seeds was fabricated using celsian as the additive and by pressureless sintering. The microstructure of the material was observed and analyzed using XRD, SEM, and TEM and the mechanical response of this array microstructure was characterized for flexural strength and fracture behavior. The result shows that the growth of the larger aspect ratio grains initiate mainly from the seeds through the heterogeneous nucleation mechanism during the process of phase transformation, and the intergranular phase BaAl2Si20s services as good refractory materials. In contrast to conventional processing, a stable bimodal microstructure and complicated component with a lower cost can be achieved using the abovementioned process theoretically and practically.

关键词： silicon nitride ceramics celsian β-silicon nitride seed pressureless sintering microstructure properties