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International Journal of Agricultural and Biological Engineering 2023年第2期16卷 30-37页

作者： Jianmin Gao Yinan Guo Mazhar Hussain Tunio xiangchao chen Zhijian chen School of Agricultural Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

In the process of aeroponics cultivation,the atomizer is one of the most important influencing factors on the cultivation *** study presented the design of an ultrasonic atomization nozzle using contact charging and a root droplet adhesion test *** purpose of this study was to reveal the relationship between the main operating parameters of the high-voltage electrostatic ultrasonic atomization nozzle and the atomization effect using droplet adhesion *** this study,the ultrasonic effect of nozzle was achieved by using Laval tube,and the design of the key parameters for the high-voltage electrostatic ultrasonic atomization nozzle were inlet pressure,electrostatic voltage root core electrode material and spray distance;the droplet size variation and root adhesion patterns were obtained through *** best operating parameters were analyzed by using the orthogonal test method,and the droplet deposition distribution of the root system at different scales was investigated in the atomization *** test results revealed that when the root core electrode material was coppe and the nozzle working parameters were at 0.4 MPa of inlet pressure,at 1.75 m the spray distance,at 12 kV of the electrostatic voltage,the root system has the highest droplet adhesion.

关键词： ultrasonic nozzle high pressure electrostatic system droplet size measurement root adhesion test droplet deposition effect

Experimental study on the sandstone abrasiveness via mineral composition and microstructure analysis

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PETROLEUM 2024年第3期10卷 440-445页

作者： Shi, xiangchao Tang, Yang chen, Shuai Gao, Leiyu Wang, Yuming Southwest Petr Univ State Key Lab Oil & Gas Reservoir Geol & Exploitat Chengdu 610500 Peoples R China

Rock abrasiveness is an important factor affecting the tool's lifetime and efficiency in breaking a rock. Characterizing rock abrasiveness helps in the design, optimization, and mean-life prediction of tools. Xray diffraction, cast thin section analysis, and CERCHAR abrasiveness tests were performed on 18 different sandstones to characterize rock abrasiveness and explore new methods for characterization. The relationship between the mineral composition and microstructure of sandstone and abrasiveness was investigated. The results show that different structural maturities have varying effects on abrasiveness. In addition, the higher the structural maturity, the more the abrasiveness. Furthermore, in sandstones of the same structural maturity, the abrasiveness increases with equivalent quartz content (EQC). The texture coefficient (TC) and CERCHAR abrasiveness index (CAI) of sandstones with the same structural maturity showed a good linear relationship. Moreover, the correlation coefficients considering the combined parameters are above 0.85. Therefore, obtaining the microstructure and mineral composition of sandstone can effectively characterize rock abrasiveness. It also provides a new method for predicting the abrasiveness of the rock in the well. (c) 2023 Southwest Petroleum University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// ***/licenses/by-nc-nd/4.0/).

关键词： Abrasiveness Microstructure Mineral compositions Structural maturity Equivalent quartz content Sandstone CERCHAR ABRASIVITY INDEX GEOMECHANICAL PROPERTIES ROCK STRENGTH CAI DRILLABILITY PREDICTION TEXTURE DRILL WEAR

First wetland mapping at 10-m spatial resolution in South America using multi-source and multi-feature remote sensing data

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Science China Earth Sciences 2024年第10期67卷 3252-3269页

作者： Weiwei SUN Gang YANG Yuling HUANG Dehua MAO Ke HUANG Lin ZHU xiangchao MENG Tian FENG Chao chen Yong GE Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences&Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Natural Resources and Planning Bureau Shanghai Pudong New DistrictShanghai 200100China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China School of Geography Science and Geomatics Engineering Suzhou University of Science and TechnologySuzhou 215009China

Wetland degradation has been accelerating in recent years globally. Accurate information on the geographic distribution and categories of wetlands is essential for their conservation and management. Despite being the world′s fourth largest continent, South America has limited research on wetland mapping, and there is currently no available map that provides comprehensive information on wetland distribution and categories in the region. To address this issue, we used Sentinel-1, Sentinel-2 and SRTM data, developed a sample collection method and a wetland mapping method with a collection of multi-source features such as optical features, polarization features and shape features for South American wetlands. We produced a 10-m resolution wetland map based on the Google Earth Engine(GEE) platform. Our Level-1 wetland cover map accurately captured six wetland sub-categories with an overall accuracy of 96.24% and a kappa coefficient of 0.8649, while our Level-2 water cover map included five sub-categories with an overall accuracy of 97.23% and a kappa coefficient of0.9368. The results show that the total area of existing wetlands in South America is approximately 1,737,000 km~2, which is6.8% of the total land area. Among the ten wetland categories, shallow sea had the largest area(960,527.4 km~2), while aquaculture ponds had the smallest area 1513.6 km~2. Swamp had the second largest area(306,240.1 km~2). Brazil, Argentina,Venezuela, Bolivia, and Colombia were found to have the largest wetland areas, with Brazil and Colombia having the most diverse wetland categories. This product can serve as baseline data for subsequent monitoring, management, and conservation of South American wetlands.

关键词： Wetland mapping Google Earth Engine Sentinel imagery South America

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Single-source-precursor synthesis and air-plasma ablation behavior of(Ti,Zr,Hf)C/SiC ceramic nanocomposites at 2200℃

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Journal of Advanced Ceramics 2024年第7期13卷 1043-1059页

作者： Li Lu Qingbo Wen Jinrun Hu Tianxing Jiang xiangchao Ren Yalei Wang Yi Zeng Xiang Xiong State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Dense monolithic(Ti,Zr,Hf)C/SiC ceramic nanocomposites with four different molar ratios of metallic elements in the(Ti,Zr,Hf)C phase(i.e.,Ti:Zr:Hf=1:1:1,2:3:5,2:3:3,and 1:2:1)were prepared upon pyrolysis of novel(Ti,Zr,Hf)-containing single-source precursors(SSPs),followed by spark plasma sintering(SPS).A thorough characterization was conducted to elucidate the synthesis of the SSPs,polymer-to-ceramic transformation,chemical/phase compositions,and microstructure of the SiTiZrHfC-based *** results revealed the feasibility of synthesizing nanocomposites with high(Ti,Zr,Hf)C contents using the SSP *** nanocomposites were characterized by a unique microstructure with in situ generated(Ti,Zr,Hf)C@C core-shell nanoparticles homogeneously mixed withβ-*** ablation behavior of the nanocomposites was evaluated on an air-plasma device for 60 ***,the nanocomposites exhibited excellent ablation resistance,and the lowest linear ablation rate reached−0.58μm/s at 2200°***,the ablation resistance can be dramatically improved by precisely tailoring the atomic ratios of metal elements within the(Ti,Zr,Hf)C phase via the molecular design of the *** formation of a multiple-oxide layer with both a high-meltingpoint phase((Ti,Zr,Hf)O_(2))and low-melting-point phases((Zr,Hf)TiO_(4))and glassy SiO_(2),as well as their structure,played a critical role in the enhanced ablation *** uniform distribution of the high-melting-point(Ti,Zr,Hf)O_(2)nano/microparticles throughout the glassy SiO_(2)matrix significantly enhanced the viscosity and stability of the oxide layer by the pinning effect,offering superior protection against the ingress of oxygen atoms and excellent resistance to mechanical erosion.

关键词： ultrahigh-temperature ceramics(UHTCs) multicomponent carbide nanocomposites ablation behavior multiple oxides

Development and experiments of low frequency ultrasonic electrostatic atomizing nozzle with double resonators

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International Journal of Agricultural and Biological Engineering 2022年第4期15卷 39-48页

作者： Jianmin Gao Ke Xu Rui He xiangchao chen Mazhar Hussain Tunio School of Agricultural Engineering Jiangsu UniversityZhenjiang 212013China

Fine droplets with high adhesion can greatly improve the efficiency of atomization ***,the development of a spray nozzle that can produce fine fog droplets with high adhesion is of great significance for *** to piezoelectric ultrasonic atomizer,Hartmann resonator low-frequency ultrasonic electrostatic atomizer has the advantages of large atomization volume and constant liquid chemical structure,but the droplet size is ***-speed gas can generate low-frequency ultrasonic vibration sound waves in Hartmann *** frequency and intensity of sound waves determine the atomization performance of supersonic atomizer ***,very few research literatures can be found on how the structure and operating parameters of Hartmann resonator affect the atomization *** order to improve the atomization performance of ultrasonic atomizer,a two-stage Hartmann resonator low-frequency ultrasonic electrostatic atomizer was *** shrinkage-type Laval tube was designed by fluid mechanics theory,and the design results were verified by fluent *** virtual orthogonal test method was used to optimize the structure parameters of two-stage resonator and spray test was carried *** results showed that when the included angle between the two stage resonators was 80°,the diameter was 4.86 mm,the tube length ratio was 1.0 and the gas pressure was 0.5 MPa,the droplet size could reach 22.05μ***,compared with the traditional Hartmann cavity with 90°included angle,the droplet size was decreased by 63%.The annular electrode was used as the charging electrode,and Comsol Multiphysics software was used to simulate and calculate the deformation and crushing process of electrostatic droplets and the influence of different voltage,surface tension and droplet diameter on the droplet deformation *** results showed that:(1)the optimum charge range of the electrode ring was within 20 mm of the axial distance along the ele

关键词： ultrasonic atomization Laval tube two-stage resonance tube electrostatic spray deformation rupture simulation analysis

碱式硫酸镁水泥早期水化和力学性能的电阻抗法试验研究

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哈尔滨工程大学学报 2024年第7期45卷 1415-1420页

作者：曾翔超长江师范学院土木学院重庆408100

针对碱式硫酸镁水泥的早期水化行为和力学性能关系的研究尚不充分,本文主要采用电阻抗法结合抗压强度测试、X射线衍射、扫描电镜和压汞法进行了研究。根据实测电阻率曲线将碱式硫酸镁水泥早期水化过程分为诱导期、加速期和减速期3个阶... 详细信息

针对碱式硫酸镁水泥的早期水化行为和力学性能关系的研究尚不充分,本文主要采用电阻抗法结合抗压强度测试、X射线衍射、扫描电镜和压汞法进行了研究。根据实测电阻率曲线将碱式硫酸镁水泥早期水化过程分为诱导期、加速期和减速期3个阶段。利用获得的电阻率微分曲线上的特征点A(电阻率开始增长的时间)和特征点B(电阻率增长达到最大值的时间)求得BMSC的初凝和终凝时间。此外,建立碱式硫酸镁水泥水化24 h电阻率与28 d抗压强度的拟合直线方程,通过实测水化后24 h的电阻率能准确预测碱式硫酸镁水泥的28 d抗压强度,为BMSC水化早期性能监测提供一种可行、准确的方法。

关键词：电阻抗法碱式硫酸镁水泥力学性能早期水化行为线性拟合抗压强度特征点

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The RNA binding protein EHD6 recruits the m^(6)A reader YTH07 and sequesters OsCOL4 mRNA into phase-separated ribonucleoprotein condensates to promote rice flowering

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Molecular Plant 2024年第6期17卷 935-954页

作者： Song Cui Peizhe Song Chaolong Wang Saihua chen Benyuan Hao Zhuang Xu Liang Cai Xu chen Shanshan Zhu xiangchao Gan Hui Dong Yuan Hu Liang Zhou Haigang Hou Yunlu Tian Xi Liu Liangming chen Shijia Liu Ling Jiang Haiyang Wang Guifang Jia Shirong Zhou Jianmin Wan State Key Laboratory for Crop Genetics&Germplasm Enhancement and Utilization Zhongshan Biological Breeding LaboratoryNational Observation and Research Station of Rice Germplasm ResourcesNanjing Agricultural UniversityNanjing 210095China State Key Laboratory for Crop Gene Resources and Breeding Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijing 100081China Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular SciencesKey Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking-Tsinghua Center for Life SciencesBeijing Advanced Center of RNA BiologyPeking UniversityBeijingChina Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding Agricultural College of Yangzhou UniversityYangzhou 225009China Max Planck Institute for Plant Breeding Research Carl-von-Linne´-Weg 1050829 KolnGermany

N6-Methyladenosine(m^(6)A)is one of the most abundant modifications of eukaryotic mRNA,but its comprehensive biological functionality remains further *** this study,we identified and characterized a new flowering-promoting gene,EARLY HEADING DATE6(EHD6),in ***6 encodes an RNA recognition motif(RRM)-containing RNA binding protein that is localized in the non-membranous cytoplasm ribonucleoprotein(RNP)granules and can bind both m^(6)A-modified RNA and unmodified RNA *** found that EHD6 can physically interact with YTH07,a YTH(YT521-B homology)domain-containing m^(6)A *** showed that their interaction enhances the binding of an m^(6)A-modified RNA and triggers relocation of a portion of YTH07 from the cytoplasm into RNP granules through phase-separated *** these condensates,the mRNA of a rice flowering repressor,CONSTANS-like 4(OsCOL4),becomes sequestered,leading to a reduction in its protein abundance and thus accelerated flowering through the Early heading date 1 *** together,these results not only shed new light on the molecular mechanism of efficient m^(6)A recognition by the collaboration between an RNA binding protein and YTH family m^(6)A reader,but also uncover the potential for m^(6)A-mediated translation regulation through phaseseparated ribonucleoprotein condensation in rice.

关键词： N6-methyladenosine m^(6)A EHD6 YTH domain-containing protein phase separation heading date

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岩石可钻性分级标准的改进建议

石油学报 2024年第9期45卷 1432-1442页

作者：石祥超陈帅西南石油大学油气藏地质及开发工程全国重点实验室四川成都610500

岩石可钻性分级是指导钻井工艺技术优化、提高钻井效率的重要依据,对推动钻井工程技术进步具有重要意义。在过去几十年,岩石可钻性分级标准不断完善,但随着工业的进步和钻井深度的不断增加,岩石可钻性分级标准也逐渐与钻井工业技术的进... 详细信息

岩石可钻性分级是指导钻井工艺技术优化、提高钻井效率的重要依据,对推动钻井工程技术进步具有重要意义。在过去几十年,岩石可钻性分级标准不断完善,但随着工业的进步和钻井深度的不断增加,岩石可钻性分级标准也逐渐与钻井工业技术的进步不相适应,存在难以区分难钻地层、难以指导钻井工艺技术优化等问题。因此,有必要对可钻性分级方法进行改进以便适应当前和未来技术的发展。通过回顾岩石可钻性分级方法的发展历史及其局限性,开展了大量覆盖三大类岩性的可钻性试验并进行统计分析。分析结果表明,不能依据可钻性测试结果的统计分布情况建立分级标准,两种微钻头测试的结果相关性较差,PDC微钻头可钻性测试结果可重复性较好,作为可钻性测试方法更科学;通过对岩石可钻性计算模型进行讨论,建议未来可钻性的分级标准应将区分硬地层为重要目标进行改进;针对PDC微钻头和牙轮微钻头提出了可钻性指数概念及计算方法;建议将PDC微钻头有效钻进时间0~60 s、60~360 s、360~600 s和大于600 s分别归为"软"、"中下—中—中上"、"硬下—硬—硬上"和"极硬",可钻性指数分别对应0~10、10~60、60~100和大于100;建议将牙轮微钻头有效钻进时间0~40 s、40~280 s、280~400 s和大于400 s分别归为"软"、"中下—中—中上"、"硬下—硬—硬上"和"极硬",可钻性指数分别对应0~10、10~70、70~100和大于100。

关键词：钻井工程岩石可钻性分级可钻性指数 PDC微钻头牙轮微钻头

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熟料中碱金属硫酸盐对水泥早期凝结的影响

硅酸盐学报 2017年第5期45卷 690-696页

作者：孙化强钱觉时杨莎熊青青陈祥超重庆大学材料科学与工程学院重庆400044

通过煅烧碱金属硫酸盐来模拟水泥熟料中的原生碱金属硫酸盐对水泥早期凝结行为的影响,根据ASTM C451水硬性水泥早凝测试方法研究不同碱金属硫酸盐对水泥早期凝结性能的影响,建立了不同硫酸钾、硫酸钠与石膏比例下水泥正常凝结、假凝和... 详细信息

通过煅烧碱金属硫酸盐来模拟水泥熟料中的原生碱金属硫酸盐对水泥早期凝结行为的影响,根据ASTM C451水硬性水泥早凝测试方法研究不同碱金属硫酸盐对水泥早期凝结性能的影响,建立了不同硫酸钾、硫酸钠与石膏比例下水泥正常凝结、假凝和速凝的区域范围,并采用水化微量热仪、综合热分析仪和X射线衍射仪对水泥水化热及水化产物进行分析。结果表明:当硫酸钾或者硫酸钠含量高于总硫酸盐含量的75%以上时水泥会出现早凝,硫酸钾或硫酸钠钾会使水泥会发生假凝;硫酸钠会使水泥出现速凝,外掺更多石膏才能缓解这一不利影响。熟料中硫酸钾、硫酸钠钾会与石膏反应形成钾石膏引起假凝。可根据熟料中碱金属硫酸盐含量对水泥早期凝结行为进行预判,也可以通过调整碱金属硫酸盐和石膏的比例来调控水泥的早期凝结行为。

关键词：硫酸钠钾硫酸钾硫酸钠钾石膏速凝假凝

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大洋湾湿地公园蓝藻水华成因及治理对策研究

水资源开发与管理 2023年第1期9卷 65-68,64页

作者：陈向超上海汀滢环保科技有限公司上海201707

本文以大洋湾湿地公园为例,探究了该湿地公园蓝藻暴发的主要成因:水体相对封闭、流速较缓、水体交换周期长、生态系统不完整等,针对存在的问题,提出水循环系统重构、底泥薄层清除、水生态修复、水生态优化、水质监测等方面的措施,以提... 详细信息

本文以大洋湾湿地公园为例,探究了该湿地公园蓝藻暴发的主要成因:水体相对封闭、流速较缓、水体交换周期长、生态系统不完整等,针对存在的问题,提出水循环系统重构、底泥薄层清除、水生态修复、水生态优化、水质监测等方面的措施,以提升水质,增加湿地生态系统生物多样性,抑制蓝藻水华,可为类似水体治理提供参考。

关键词：大洋湾湿地蓝藻水华成因分析治理措施