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中国植物性饮食结构调整具有显著的耕地资源效应

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Science Bulletin 2024年第6期69卷 737-740页

作者：朱晓华张燕朱媛媛李裕瑞 Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China key laboratory of Geographic process analysis&simulation hubei province Central China Normal UniversityWuhan 430079China

Food systems are already a major contributor to land degradation,and changes in global diets will exacerbate this situation[1].Population growth and affluent dietary patterns result in changes in land demand and land-use patterns,and up to 40% of global arable land and more than 30% of global food-crop production are used for animal feed[2].Furthermore,food-feed competition can result in an inadequate food supply[3].

关键词：耕地资源 arable food

A phenology-based vegetation index for improving ratoon rice mapping using harmonized Landsat and Sentinel-2 data

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Journal of Integrative Agriculture 2024年第4期23卷 1164-1178页

作者： Yunping Chen Jie Hu Zhiwen Cai Jingya Yang Wei Zhou Qiong Hu Cong Wang Liangzhi You Baodong Xu Macro Agriculture Research Institute College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China College of Resources and Environment Huazhong Agricultural UniversityWuhan 430070China key laboratory of Agricultural Remote Sensing Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China key laboratory for geographical process analysis&simulation of hubei province/College of Urban and Environmental Sciences Central China Normal UniversityWuhan 430079China International Food Policy Research Institute NWWashingtonD.C.20005USA

Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in hubei province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRV

关键词： ratoon rice phenology-based ratoon rice vegetation index(PRVI) phenological phase feature selection Harmonized Landsat Sentinel-2 data

analysis of the Flow Field and Impact Force in High-Pressure Water Descaling

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Fluid Dynamics & Materials processing 2024年第1期20卷 165-177页

作者： Yue Cui Liyuan Wang Jian Wu Haisheng Liu Di Wu key Lab of Intelligent Equipment Digital Design and process simulation Hebei ProvinceTangshan UniversityTangshan063000China Department of Intelligent Manufacturing Tangshan Vocational College of Science and TechnologyTangshan063001China

This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications.

关键词： High pressure water descaling flow field analysis FSI target distance strike range

Anisotropic shearing mechanism of Kangding slate:Experimental investigation and numerical analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1487-1504页

作者： Ping Liu Quansheng Liu Penghai Deng Yucong Pan Yiming Lei Chenglei Du Xianqi Xie The key laboratory of Geotechnical and Structural Engineering Safety of hubei province School of Civil EngineeringWuhan UniversityWuhan430072China State key laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

The shear mechanical behavior is regarded as an essential factor affecting the stability of the surrounding rocks in underground engineering.The shear strength and failure mechanisms of layered rock are significantly affected by the foliation angles.Direct shear tests were conducted on cubic slate samples with foliation angles of 0°,30°,45°,60°,and 90°.The effect of foliation angles on failure patterns,acoustic emission(AE)characteristics,and shear strength parameters was analyzed.Based on AE characteristics,the slate failure process could be divided into four stages:quiet period,step-like increasing period,dramatic increasing period,and remission period.A new empirical expression of cohesion for layered rock was proposed,which was compared with linear and sinusoidal cohesion expressions based on the results made by this paper and previous experiments.The comparative analysis demonstrated that the new expression has better prediction ability than other expressions.The proposed empirical equation was used for direct shear simulations with the combined finite-discrete element method(FDEM),and it was found to align well with the experimental results.Considering both computational efficiency and accuracy,it was recommended to use a shear rate of 0.01 m/s for FDEM to carry out direct shear simulations.To balance the relationship between the number of elements and the simulation results in the direct shear simulations,the recommended element size is 1 mm.

关键词： Anisotropy Empirical expression of cohesion foliation angles Combined finite-discrete element method(FDEM) Shear rate Element size

High nitrogen fertilizer input enhanced the microbial network complexity in the paddy soil

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Soil Ecology Letters 2024年第2期6卷 97-109页

作者： Yanan Chen Yan Li Tianyi Qiu Haoran He Ji Liu Chengjiao Duan Yongxing Cui Min Huang Chunyan Wu Linchuan Fang The Research Center of Soil and Water Conservation and Ecological Environment Chinese Academy of Sciences and Ministry of EducationYangling712100China State key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation CAS and MWRYangling712100China University of Chinese Academy of Sciences Beijing100049China Institute of Environment Resource and Soil Fertilizer Zhejiang Academy of Agricultural SciencesHangzhou310021China College of Natural Resources and Environment Northwest A&F UniversityYangling712100China hubei province key laboratory for geographical process analysis and simulation Central China Normal UniversityWuhan430079China Department of Ecohydrology Leibniz Institute of Freshwater Ecology and Inland FisheriesBerlin12587Germany Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking UniversityBeijing100871China College of Resources and Environmental Engineering Wuhan University of TechnologyWuhan430070China CAS Center for Excellence in Quaternary Science and Global Change Xi’an710061China

N fertilizer altered bacterial community compositions by changing soil nutrients.•Bacterial ammonia oxidation became predominated with the increasing N rate.•Excessive N input caused the information of a more complex microbial network.•Intensified microbial competition by excessive N was due to negative link increase.Nitrogen(N)fertilization drives the structure and function of soil microbial communities,which are crucial for regulating soil biogeochemical cycling and maintaining ecosystem stability.Despite the N fertilizer effects on soil microbial composition and diversity have been widely investigated,it is generally overlooked that ecosystem processes are carried out via complex associations among microbiome members.Here,we examined the effects of five N fertilization levels(0,135,180,225,and 360 kg N ha−1)on microbial co-occurrence networks and key functional taxa such as ammonia-oxidizers in paddy soils.The results showed that N addition altered microbial community composition,which were positively related to soil total N and available phosphorus(P)contents.The abundance of ammonia-oxidizing archaea(AOA)significantly decreased after N addition,whereas ammonia-oxidizing bacteria(AOB)increased in N360 treatment.Compared with low-N group(N0 and N135),the high-N group(N225 and N360)shaped more complex microbial webs and thus improved the stability of the microbial community.Partial least squares path modeling further revealed that N fertilizer had a higher effect on microbial network complexity in the high-N group(0.83)than the low-N group(0.49).Although there were more positive links across all microbial networks,the proportion of negative links significantly increased in the high-N network,suggesting that excess N addition aggravated the competition among microbial species.Disentangling these interactions between microbial communities and N fertilization advances our understanding of biogeochemical processes in paddy soils and their effects on nutrient supply to rice production.Our findings highlighted that h

关键词： nitrogen fertilizer paddy soil co-occurrence network microbial interaction

Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1557-1565页

作者： Jin-Xi Zhang Kai-Di Xu Qing-Guo Wang IEEE the State key laboratory of Synthetical Automation for process Industries Northeastern UniversityShenyang 110819China Institute of Artificial Intelligence and Future Networks Beijing Normal UniversityZhuhai 519087 Guangdong key laboratory of Artificial Intelligence and Multi-Modal Data processing Beijing Normal University-Hong Kong Baptist University United International CollegeZhuhai 519087

The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this paper.Herein, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings.

关键词： Nonlinear systems output constraints prescribed performance reference tracking time delays

simulation-Based Investigation of Crack Formation in Forged MB15 Magnesium Alloy

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Journal of Electronic Research and Application 2024年第1期8卷 73-79页

作者： Lulu Song Dongmei Liu Jie Yuan Ruihuan Tian Liying Jin Metrological Physics and Chemistry Center AVIC Aerospace Life-Support IndustriesLtd.Xiangyang 441003Hubei ProvinceChina Xiangyang key laboratory of Intelligent Manufacturing and Machine Vision Hubei University of Arts and ScienceXiangyang 441053Hubei ProvinceChina

In the process of riveting an MB15 forging die,cracks were discovered emerging along the longitudinal direction and near the riveting hole.Through fracture analysis,microscopic observation,energy spectrum analysis,metallographic examination,and hardness test,the properties and causes of the cracks are discussed.The results indicate that the cracking type is intergranular brittle cracking,occurring during the forging stage.Furthermore,the recrystallization at the crack site is found to be incomplete,which is attributed to the low deformation temperature.

关键词： MB15 Forging die Crack Deformation temperature

Research and Application of a Multi-Field Co-simulation Data Extraction Method Based on Adaptive Infinitesimal Element

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工程与科学中的计算机建模(英文) 2024年第1期138卷 321-348页

作者： Changfu Wan Wenqiang Li Sitong Ling Yingdong Liu Jiahao Chen School of Mechanical Engineering Sichuan UniversityChengdu610065China Innovation Method and Creative Design key laboratory of Sichuan province Sichuan UniversityChengdu610065China

Regarding the spatial profile extraction method of a multi-field co-simulation dataset,different extraction directions,locations,and numbers of profileswill greatly affect the representativeness and integrity of data.In this study,a multi-field co-simulation data extractionmethod based on adaptive infinitesimal elements is proposed.Themultifield co-simulation dataset based on related infinitesimal elements is constructed,and the candidate directions of data profile extraction undergo dimension reduction by principal component analysis to determine the direction of data extraction.Based on the fireworks algorithm,the data profile with optimal representativeness is searched adaptively in different data extraction intervals to realize the adaptive calculation of data extraction micro-step length.The multi-field co-simulation data extraction process based on adaptive microelement is established and applied to the data extraction process of the multi-field co-simulation dataset of the sintering furnace.Compared with traditional data extraction methods for multi-field co-simulation,the approximate model constructed by the data extracted from the proposed method has higher construction efficiency.Meanwhile,the relative maximum absolute error,root mean square error,and coefficient of determination of the approximationmodel are better than those of the approximation model constructed by the data extracted from traditional methods,indicating higher accuracy,it is verified that the proposed method demonstrates sound adaptability and extraction efficiency.

关键词： Multi-field co-simulation adaptive infinitesimal elements principal component analysis fireworks algorithm sintering furnace simulation

Mapping winter rapeseed in South China using Sentinel-2 data based on a novel separability index

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Journal of Integrative Agriculture 2023年第6期22卷 1645-1657页

作者： TAO Jian-bin ZHANG Xin-yue WU Qi-fan WANG Yun key laboratory for geographical process analysis&simulation of hubei province/School of Urban and Environmental Sciences Central China Normal UniversityWuhan 430079P.R.China

Large-scale crop mapping using remote sensing data is of great significance for agricultural production, food security and the sustainable development of human societies. Winter rapeseed is an important oil crop in China that is mainly distributed in the Yangtze River Valley. Traditional winter rapeseed mapping practices are insufficient since they only use the spectral characteristics during the critical phenological period of winter rapeseed, which are usually limited to a small region and cannot meet the needs of large-scale applications. In this study, a novel phenology-based winter rapeseed index(PWRI) was proposed to map winter rapeseed in the Yangtze River Valley. PWRI expands the date window for distinguishing winter rapeseed and winter wheat, and it has good separability throughout the flowering period of winter rapeseed. PWRI also improves the separability of winter rapeseed and winter wheat, which traditionally have been two easily confused winter crops. A PWRI-based method was applied to the Middle Reaches of the Yangtze River Valley to map winter rapeseed on the Google Earth Engine platform. Time series composited Sentinel-2 data were used to map winter rapeseed with 10 m resolution. The mapping achieved a good result with overall accuracy and kappa coefficients exceeding 92% and 0.85, respectively. The PWRI-based method provides a new solution for high spatial resolution winter rapeseed mapping at a large scale.

关键词： phenology-based winter rapeseed index winter rapeseed mapping Sentinel-2 Google Earth Engine