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Phytochemical Profile,Fatty Acid Composition,Mineral Content,andα-Amylase/α-Glucosidase Inhibitory Activities of Date Seed Extracts from Four Moroccan Varieties Grown in the Figuig Oasis
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作者 Manar Bouhchich Abdessadek Rahimi +3 位作者 Rhizlan Abdnim Amine Elbouzidi Mohamed Addi Mostafa Mimouni 《Phyton-International Journal of Experimental Botany》 2026年第2期184-203,共20页
Date palm(Phoenix dactylifera L.)seeds,often discarded as by-products during date fruit processing,represent approximately 6-20%of the fruit’s mass depending on cultivar and maturity stage.Although traditionally used... Date palm(Phoenix dactylifera L.)seeds,often discarded as by-products during date fruit processing,represent approximately 6-20%of the fruit’s mass depending on cultivar and maturity stage.Although traditionally used for producing activated charcoal and in environmental remediation,their pharmacological potential remains underexplored.This study aimed to evaluate the chemical composition,biological activity,and potential commercial value of seeds from four widely consumed Saharan cultivars(Assiane,Boufegouss,Aziza,and Majhoul)collected in the Figuig region.Soxhlet extraction was employed to obtain seed extracts,which were subsequently characterized by qualitative and quantitative phytochemical screening.The analyses revealed the presence of polyphenols,flavonoids,terpenoids,steroids,alkaloids,and other secondary metabolites.The Aziza and Boufegouss varieties were particularly rich in flavonoids(82.09-139.61 mg quercetin equivalents/100 g dry matter)and total polyphenols(69.81-1183.96 mg gallic acid equivalents/100 g dry matter).Mineral profiling confirmed the occurrence of essential trace elements,including Zn,Cu,Fe,and Co.To investigate their antidiabetic potential,in vitro assays ofα-glucosidase andα-amylase inhibition were performed.Acetone extracts demonstrated significant inhibitory activity against both enzymes,suggesting a promising role of P.dactylifera seed extracts as natural agents for the management of type 2 diabetes mellitus. 展开更多
关键词 Phoenix dactylifera L. date seeds PHYTOCHEMICALS mineral analysis Α-AMYLASE Α-GLUCOSIDASE antidiabetic potential
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A Multi-Stage Pipeline for Date Fruit Processing: Integrating YOLOv11 Detection, Classification, and Automated Counting
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作者 Ali S.Alzaharani Abid Iqbal 《Computers, Materials & Continua》 2026年第1期1327-1353,共27页
In this study,an automated multimodal system for detecting,classifying,and dating fruit was developed using a two-stage YOLOv11 pipeline.In the first stage,the YOLOv11 detection model locates individual date fruits in... In this study,an automated multimodal system for detecting,classifying,and dating fruit was developed using a two-stage YOLOv11 pipeline.In the first stage,the YOLOv11 detection model locates individual date fruits in real time by drawing bounding boxes around them.These bounding boxes are subsequently passed to a YOLOv11 classification model,which analyzes cropped images and assigns class labels.An additional counting module automatically tallies the detected fruits,offering a near-instantaneous estimation of quantity.The experimental results suggest high precision and recall for detection,high classification accuracy(across 15 classes),and near-perfect counting in real time.This paper presents a multi-stage pipeline for date fruit detection,classification,and automated counting,employing YOLOv11-based models to achieve high accuracy while maintaining real-time throughput.The results demonstrated that the detection precision exceeded 90%,the classification accuracy approached 92%,and the counting module correlated closely with the manual tallies.These findings confirm the potential of reducing manual labour and enhancing operational efficiency in post-harvesting processes.Future studies will include dataset expansion,user-centric interfaces,and integration with harvesting robotics. 展开更多
关键词 date fruit cultivation YOLOv11 precision agriculture real-time processing automated fruit counting deep learning agricultural productivity
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Variations in the starting date of the pre-summer rainy season in South China, 1736-2010 被引量:1
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作者 DING Lingling GE Quansheng +1 位作者 ZHENG Jingyun HAO Zhixin 《Journal of Geographical Sciences》 SCIE CSCD 2014年第5期845-857,共13页
The starting dates of the pre-summer rainy season during historical times (1736- 1911) in Fuzhou and Guangzhou of South China, were determined and reconstructed on the basis of historical documents in the Yu-Xue-Fen... The starting dates of the pre-summer rainy season during historical times (1736- 1911) in Fuzhou and Guangzhou of South China, were determined and reconstructed on the basis of historical documents in the Yu-Xue-Fen-Cun archive, together with observed features of precipitation during the pre-summer rainy season. In addition, starting dates of the pre-summer rainy season from 1953 in Fuzhou and from 1952 in Guangzhou were reconstructed for the instrumental period. These data allowed for analyses of inter-annual and inter-decadal changes in the starting dates of the pre-summer rainy season in South China over the past 300 years. Results show that the mean starting date of the pre-summer rainy season in South China was the first pentad of May; in addition, periodicities in the starting dates of 2-3 years, 10 years, and 40 years were detected during the period 1736-1911, and of 2-3 years, 10 years, and 22 years during the instrumental period. From 1736 to 1911, the earliest starting dates at Fuzhou and Guangzhou both occurred at the fourth pentad of April, while the latest starting dates were at the sixth pentad of May in Fuzhou and the first pentad of June in Guangzhou. During the instrumental period, the earliest and latest starting dates were at the fourth pentad of April and the first pentad of June, respectively, in both Fuzhou during 1953-2010 and Guangzhou during 1952-2010. The maximum difference between neighboring decades during 1736-1911 was 2.2 and 1.6 pentads in Fuzhou and Guangzhou, respectively, and during the instrumental period it was 2.5 and 2.4 pentads in Fuzhou and Guangzhou, respectively. 展开更多
关键词 South China starting date of the pre-summer rainy season reconstruction variation Yu-Xue-Fen-Cun
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Updating the Outdated
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作者 QI YU 《China Today》 2025年第3期74-75,共2页
The ideology of being ready to make innovation and keeping abreast of the times is a defining feature of the Chinese civilization.IN several of his recent speeches President Xi Jinping stressed that the Chinese civili... The ideology of being ready to make innovation and keeping abreast of the times is a defining feature of the Chinese civilization.IN several of his recent speeches President Xi Jinping stressed that the Chinese civilization has the tradition of discarding the outdated in favor of the new and moving ahead with the times.In exploring a new philosophy that is suitable for governing China in the new era,China draws on its fine traditional culture to find ways of abolishing outdated ideas and making theoretical,practical,and institutional innovations,thus staying abreast of the time to create a better future. 展开更多
关键词 dated DATING CULTURE
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Optimizing sowing dates increase solar radiation to mitigate maize lodging and yield variability:A five-year field study
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作者 Xinglong Wang Fan Liu +7 位作者 Nan Zhao Xia Du Pijiang Yin Tongliang Li Tianqiong Lan Dongju Feng Fanlei Kong Jichao Yuan 《Journal of Integrative Agriculture》 2025年第12期4573-4587,共15页
Optimizing sowing dates(SDs)represents a viable strategy for adapting maize production to climate change and enhancing yield.However,research remains limited regarding the integrated effects of lodging and yield in re... Optimizing sowing dates(SDs)represents a viable strategy for adapting maize production to climate change and enhancing yield.However,research remains limited regarding the integrated effects of lodging and yield in relation to climatic variables across different SDs.This study examines the patterns and distribution of key climatic variables during maize growth seasons,their influence on yield and lodging,and the critical factors affecting lodging at crucial growth stages under various SD scenarios.The research evaluated climate change impacts on yield and lodging through field experiments spanning 5 years(2015,2016,2019-2021),incorporating 25 SDs in the Sichuan Basin,China.Results indicated that lodging rate significantly affected the coefficient of variation(CV,3.31-10.50%)of maize yield.Each 1%increase in lodging rate resulted in a yield reduction of 58.05 kg ha^(-1).SD modifications notably influenced solar radiation(Sr)from emergence to silking(E-R1).The study determined that Sr accounted for 34.7%of lodging rate variation in E-R1.Analysis of historical meteorological data revealed significant inter-annual Sr variations,showing a decline of-8.7763 MJ m^(-2)yr^(-1)from 1990 to 2021,particularly evident from late May to early July.Variation partitioning analysis(VPA)demonstrated that climatic variables during emergence to physiological maturity(E-R6)and E-R1 explained 43.9 and 53.2%of yield variation across SDs,respectively,while contributing 56.0 and 45.4%to lodging.Random forest(RF)analysis established that SD changes primarily influenced lodging rates through modifications in basal internode morphology,explaining 69.79%of the variation.The research identified optimal sowing dates between late March and mid-April for achieving consistent high yields,attributed to increased Sr during E-R1.This study provides critical insights into climate change effects on stalk lodging and offers practical guidance for SD adjustment to reduce maize lodging rates. 展开更多
关键词 sowing date climatic variables stalk lodging maize yield
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Can a delayed sowing date improve the eating and cooking quality of mechanically transplanted rice in the Sichuan Basin,China?
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作者 Yuxin He Fei Deng +13 位作者 Chi Zhang Qiuping Li Xiaofan Huang Chenyan He Xiaofeng Ai Yujie Yuan Li Wang Hong Cheng Tao Wang Youfeng Tao Wei Zhou Xiaolong Lei Yong Chen Wanjun Ren 《Journal of Integrative Agriculture》 2025年第9期3368-3383,共16页
Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological c... Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological conditions.In this study,we conducted experiments using four different sowing dates,the conventional sowing date 1(CS1),CS2(10 d later than CS1),DS1(30 d later than CS1),and DS2(30 d later than CS2),and three rice varieties,i.e.,Yixiangyou 2115,Fyou 498,and Chuanyou 6203.This experiment was conducted at four sites in the Sichuan Basin in 2018 and 2019 to evaluate the infuence of DS on the pasting properties of rice,which are a proxy for the eating and cooking quality(ECQ).In DS1 and DS2,the rice had a signifcantly greater amylose content(AC)but a lower protein content(PC),peak viscosity(PKV),cool paste viscosity(CPV),and hot paste viscosity(HPV)than in CS1 and CS2.Moreover,except for CS2 and DS1 in 2018,DS1 and DS2 led to 2.15-11.19%reductions in breakdown viscosity(BDV)and 23.46-108.47%increases in setback viscosity(SBV).However,the infuence of DS on rice pasting properties varied by study site and rice variety.In 2019,DS1 and DS2 led to BDV reductions of 2.35-9.33,2.61-8.61,10.03-17.78,and 2.06-8.93%,and SBV increases of 2.32-60.93,63.74-144.24,55.46-91.63,and-8.28-65.37%at the Dayi,Anzhou,Nanbu,and Shehong(except for SBV in CS2 and DS1)sites,respectively.DS resulted in greater reductions in PKV,HPV,CPV,and BDV and greater increases in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.The correlation analysis indicated that PKV and HPV were signifcantly and positively related to the mean,maximum,and minimum temperatures after heading.These temperatures must be greater than 25.9,31.2,and 22.3℃,respectively,to increase the relative BDV and reduce the relative SBV of rice,thereby enhancing ECQ.In conclusion,DS might contribute to a signifcant deterioration in ECQ in machine-transplanted rice in the Sichuan Basin.A mean temperature above 25.9℃ after heading is required to improve the ECQ of rice. 展开更多
关键词 eating and cooking quality RICE sowing date pasting characteristics TEMPERATURE
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Genetic interaction network of quantitative trait genes for heading date in rice
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作者 Mengjiao Chen Yifeng Hong +6 位作者 Jiongjiong Fan Dengyi Cao Chong Yin Anjie Yu Jie Qiu Xuehui Huang Xin Wei 《Journal of Genetics and Genomics》 2025年第6期747-760,共14页
Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interacti... Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interaction network for these QTGs has not yet been established.In this study,we use 18K-rice lines to identify QTGs and their epistatic interactions affecting rice heading date.We identify 264 pairs of interacting quantitative trait loci(QTL)and construct a comprehensive genetic network of these QTL.On average,the epistatic effects of QTL pairs are estimated to be approximately 12.5%of additive effects of identified QTL.Importantly,epistasis varies among different alleles of several heading date genes.Additionally,57 pairs of interacting QTGs are also significant in their epistatic effects on 12 other agronomic traits.The identified QTL genetic interactions are further validated using near-isogenic lines,yeast two-hybrid,and split-luciferase complementation assays.Overall,this study provides a genetic network of rice heading date genes,which plays a crucial role in regulating rice heading date and influencing multiple related agronomic traits.This network serves as a foundation for understanding the genetic mechanisms of rice quantitative traits and for advancing rice molecular breeding. 展开更多
关键词 Genetic network EPISTASIS Epistatic effect Quantitative trait gene RICE Heading date
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Experimental Study on the Influence of Date Palm Fibers Reinforced Bituminous Mixtures
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作者 Saci Abdelhakim Ferkous Kahlouche Ramdane 《Journal of Building Material Science》 2025年第3期143-165,共23页
This study investigates the influence of date palm fibers(DPF)on the mechanical performance of bituminous mixtures using two experimental methodologies:the wet and dry processes.In the wet process,DPFs were pre-blende... This study investigates the influence of date palm fibers(DPF)on the mechanical performance of bituminous mixtures using two experimental methodologies:the wet and dry processes.In the wet process,DPFs were pre-blended with bitumen at varying contents ranging from 1%to 5%by weight,prior to mixing with aggregates.The resulting mixtures were evaluated based on several key performance indicators,including Marshall stability,creep resistance,compactness,and water sensitivity.The inclusion of fibers generally enhanced mechanical properties,with optimal improvements observed at 2%to 4%fiber content.Notably,the mixture with 3%DPF content demonstrated a 35.7%increase in Marshall stability,while the lowest compactness reduction(−1.9%)occurred at 1%fiber addition.In the dry process,the effects of both fiber length(1 cm,3 cm,and 5 cm)and fiber content(0.1%to 0.5%)were examined,focusing specifically on rutting and creep resistance.The results showed that 3 cm fibers significantly improved rutting resistance,whereas the 0.1%fiber content yielded the highest enhancement in creep resistance.However,no clear correlation was established between the two performance metrics,suggesting that the mechanical response is highly deformation-dependent.Overall,the addition of DPF contributed to improved durability,strength,and resistance to deformation in asphalt mixtures.The findings underscore the potential of date palm fibers as a sustainable,low-cost,and environmentally friendly additive in pavement engineering,particularly in regions where palm waste is readily available and underutilized. 展开更多
关键词 date Palm Fibers Creep Behavior Rutting Resistance Oedometric Apparatus Sustainable Development
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Optimizing sowing dates to increase maize yield across the Huanghuaihai Plain in China
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作者 Jing Chen Alam Sher +5 位作者 Baizhao Ren Ningning Yu Bin Zhao Peng Liu Wei Xiong Jiwang Zhang 《The Crop Journal》 2025年第6期1975-1980,共6页
With the aim of adapting agricultural practices to climate warming,this study projected sowing dates for summer maize in the 2030s(2031–2040)across the Huanghuaihai Plain by analyzing key photo-thermal variables deri... With the aim of adapting agricultural practices to climate warming,this study projected sowing dates for summer maize in the 2030s(2031–2040)across the Huanghuaihai Plain by analyzing key photo-thermal variables derived from field experiments and projected future climate data under Shared Socioeconomic Pathway 2–4.5 within a restricted planting season.Results showed that growing degree days(GDD)during the active dry matter accumulation period(AP),killing degree days(KDD)during AP,and GDD during the late dry matter accumulation period(LP)explained most yield variation and were used for determining suitable sowing windows.Thresholds of them were 571°C d,21°C d and 411°C d,respectively.In the 2030s,postponing sowing dates and shifting planting regions northward resulted in gradual declines in KDD during AP and GDD during LP.The proportion of regions limited by KDD and GDD changed from 66%to 0%and from 3%to 100%when sowing dates were postponed from June 1 to July 15.Suitable sowing dates for maize were determined as follows:June 25 to July 10 in regions south of 34°N,June 5 to June 30 between 34°N and 39°N,and before June 20 in regions north of 39°N. 展开更多
关键词 Maize(Zea mays L.) Dry matter accumulation and reallocation Temperature Solar radiation Sowing date
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A Deep Learning Approach to Classification of Diseases in Date Palm Leaves
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作者 Sameera V Mohd Sagheer Orwel P V +2 位作者 P M Ameer Amal BaQais Shaeen Kalathil 《Computers, Materials & Continua》 2025年第7期1329-1349,共21页
The precise identification of date palm tree diseases is essential for maintaining agricultural productivity and promoting sustainable farming methods.Conventional approaches rely on visual examination by experts to d... The precise identification of date palm tree diseases is essential for maintaining agricultural productivity and promoting sustainable farming methods.Conventional approaches rely on visual examination by experts to detect infected palm leaves,which is time intensive and susceptible to mistakes.This study proposes an automated leaf classification system that uses deep learning algorithms to identify and categorize diseases in date palm tree leaves with high precision and dependability.The system leverages pretrained convolutional neural network architectures(InceptionV3,DenseNet,and MobileNet)to extract and examine leaf characteristics for classification purposes.A publicly accessible dataset comprising multiple classes of diseased and healthy date palm leaf samples was used for the training and assessment.Data augmentation techniques were implemented to enhance the dataset and improve model resilience.In addition,Synthetic Minority Oversampling Technique(SMOTE)was applied to address class imbalance and further improve the classification performance.The system was trained and evaluated using this dataset,and two of the models,DenseNet and MobileNet,achieved classification accuracies greater than 95%.MobileNetV2 emerged as the top-performing model among those assessed,achieving an overall accuracy of 96.99%and macro-average F1-score of 0.97.All nine categories of date palm leaf conditions were consistently and accurately identified,showing exceptional precision and dependability.Comparative experiments were conducted to assess the performance of the Convolutional Neural Network(CNN)architectures and demonstrate their potential for scalable and automated disease detection.This system has the potential to serve as a valuable agricultural tool for assisting in disease management and monitoring date palm cultivation. 展开更多
关键词 Deep learning convolutional neural networks date palm disease classification InceptionV3 DenseNet MobileNet precision agriculture smart farming sustainable agriculture disease monitoring
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Cloning of qHD8^(BAS),a Quantitative Trait Locus Regulating Heading Date in Rice
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作者 ZHANG Zhengjiu BIAN Ying +3 位作者 YANG Ruoju ZHANG Xiaobo GONG Junyi FAN Jiongjiong 《Rice science》 2025年第3期283-286,I0005-I0011,共11页
Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD... Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD)conditions due to the synergistic regulation of many photosensitive genes.Using a set of chromosome segment substitution lines(CSSLs)with the indica cultivar Huanghuazhan(HHZ)as the recipient parent and Basmati Surkh 89-15(BAS)as the donor parent,we identified a QTL locus. 展开更多
关键词 chromosome segment substitution lines cssls agronomic traits identified qtl locus indica cultivar quantitative trait locus synergistic regulation many photosensitive genesusing heading date CLONING
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华北克拉通南缘少华山-崤山-熊耳山地区2.9~1.7Ga多期次花岗质岩浆作用成因与陆壳演化 被引量:1
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作者 周艳艳 郑亚莉 +5 位作者 笪永发 张儒诚 祝禧艳 赵磊 赵太平 翟明国 《岩石学报》 北大核心 2026年第1期38-70,共33页
华北克拉通太古宙-古元古代的构造-岩浆-沉积记录丰富、完整,是研究早期陆壳多阶段增生和演化规律的天然实验室。然而,目前关于其早期陆壳增生机制和构造演变过程仍存有争议。华北克拉通南缘太华杂岩发育完整的太古宙-古元古代结晶基底... 华北克拉通太古宙-古元古代的构造-岩浆-沉积记录丰富、完整,是研究早期陆壳多阶段增生和演化规律的天然实验室。然而,目前关于其早期陆壳增生机制和构造演变过程仍存有争议。华北克拉通南缘太华杂岩发育完整的太古宙-古元古代结晶基底,出露丰富的TTG及基性-花岗质岩石组合,是研究早期陆壳生长和演化的理想区域。本文聚焦华北克拉通南缘少华山-崤山-熊耳山地区2.9~1.7Ga的TTG及花岗质岩石,开展系统的岩石学、年代学和地球化学的研究。结果显示,研究区至少发育七期TTG及花岗质岩浆作用,包括~2.9Ga英云闪长岩(TTG)、~2.7Ga花岗闪长岩(TTG)、2.53~2.42Ga英云闪长岩(TTG)和钾长-二长花岗岩、2.33~2.27Ga奥长花岗岩(TTG)、闪长岩和钾长-二长花岗岩、2.22~2.19Ga二长花岗岩及侵入TTG片麻岩中的浅色脉体、1.94~1.81Ga钾长-二长花岗岩-花岗闪长岩,以及1.78~1.76Ga的钾长-二长花岗岩。其中,2.9~2.3Ga TTG以中-低压型为主;~2.5Ga的花岗质岩石显示I-S型花岗岩特征;~2.3Ga、~2.2Ga及~1.7Ga的花岗质岩石类似于A型花岗岩;1.94~1.81Ga同时发育A型花岗岩和I-S型花岗岩。~2.9Ga、~2.7Ga和~2.5Ga的三期TTG和~2.5Ga花岗质岩石记录了早期陆壳多阶段的生长和演化,可能形成于俯冲-碰撞的构造环境。~2.3Ga TTG总体具有低压特征,来自基性下地壳在高地温梯度下的部分熔融,与同期古老富集地幔来源的闪长岩和板内A型花岗岩一起指示板内伸展环境。2.2~2.1Ga A型花岗岩来自古老陆壳物质的重熔,结合已有2.3~2.1Ga双峰式火山岩、A型花岗岩、低δ18 O花岗岩-辉长闪长岩等,指示了伸展-裂解背景下不同深度地壳和地幔的再循环。1.94~1.81Ga I-S型花岗岩和A型花岗岩可能记录了古元古代俯冲-碰撞拼合的历史。1.78~1.76Ga A型花岗岩可能是板内伸展-裂解作用下的陆壳减薄诱发地壳部分熔融的产物。华北克拉通南缘太古宙-古元古代广泛发育的花岗质岩浆作用记录了多阶段的陆壳生长、演化和构造体制转型,为揭示不同阶段地球圈层物质循环规律和动力学过程提供了关键约束。 展开更多
关键词 华北克拉通南缘 2.9~1.7Ga TTG-花岗质岩石 锆石U-Pb定年 锆石Lu-Hf同位素 陆壳生长与再循环
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播期和移栽期对烤烟‘豫浓香201’生长发育及品质的影响
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作者 刘芳 孟智勇 +5 位作者 蒲团卫 王丽 孙晓伟 张东峰 王京 张生杰 《湖南农业科学》 2026年第1期29-33,共5页
为探究播期和移栽期对烤烟‘豫浓香201’生长发育及产质量的影响,筛选该品种在许昌烟区的最佳栽培模式,采用随机区组设计,设置4个处理,分别为T_(1)(早播早栽)、T_(2)(早播晚栽)、T_(3)(晚播早栽)和T_(4)(晚播晚栽),系统观测不同播栽期... 为探究播期和移栽期对烤烟‘豫浓香201’生长发育及产质量的影响,筛选该品种在许昌烟区的最佳栽培模式,采用随机区组设计,设置4个处理,分别为T_(1)(早播早栽)、T_(2)(早播晚栽)、T_(3)(晚播早栽)和T_(4)(晚播晚栽),系统观测不同播栽期组合处理对烟株生育期、病害发生情况、农艺性状、经济性状、烤烟常规化学成分和中性致香物质的影响,并评估烤烟的外观与感官质量。结果表明:T_(1)处理的上等烟比例和烟叶感官质量均偏低;T_(2)处理的烟叶外观和感官质量均较高,烟叶均价最高(31.05元/kg),但产量和产值均较低;T_(3)处理烟叶的外观质量综合评分较高,但存在早花现象,其产值为处理间最低;T_(4)处理综合表现最优,未发生早花,田间自然发病率较低,产量(2298.75 kg/hm^(2))和产值(69950.96元/hm^(2))均最高,烟叶化学成分协调性最好,中、上部烟叶中性致香物质总量均最高,较同部位最低值处理(T_(1))分别提高23.93%和17.18%,感官评吸总分亦最高。综上,建议在许昌烟区‘豫浓香201’生产中示范推广育苗期65 d的晚播晚栽(约3月6日播种,5月10日移栽)栽培模式。 展开更多
关键词 烤烟 豫浓香201 播期 移栽期 生长发育 烟叶品质
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鄂尔多斯盆地中—晚奥陶世岩相古地理演化新认识
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作者 苏中堂 黄浩 +5 位作者 魏柳斌 刘洋 师平平 任军锋 朱梦涵 付斯一 《地质学报》 北大核心 2026年第1期72-84,共13页
盆地沉积充填特征记录了周缘构造演变过程,中—晚奥陶世是鄂尔多斯盆地西缘构造变换期,岩相古地理重建可揭示该时期构造-沉积演化过程。以盆地构造演化、地层归属、沉积模式研究新认识为基础,在构造-沉积分异作用思想指导下,重建了中—... 盆地沉积充填特征记录了周缘构造演变过程,中—晚奥陶世是鄂尔多斯盆地西缘构造变换期,岩相古地理重建可揭示该时期构造-沉积演化过程。以盆地构造演化、地层归属、沉积模式研究新认识为基础,在构造-沉积分异作用思想指导下,重建了中—晚奥陶世岩相古地理。结果表明:克里摩里期,盆地构造开始转换,西缘发育潮坪-开阔台地-斜坡沉积,古隆起周缘与台地边缘发育颗粒滩;乌拉力克早期,盆地西缘处于前陆盆地鼎盛期,形成强迫海侵沉积,发育斜坡相沉积;平凉期(乌拉力克晚期—蛇山期)全球海平面达到最大,东、西海域再次贯通,盆地本部发育开阔台地相沉积,西、南缘为斜坡-盆地相沉积,发育重力流;背锅山期,原特提斯造山,盆地西、南缘为残留盆地,发育开阔台地-台地边缘-斜坡相沉积。新厘定的岩相古地理图修正了盆地平凉期的古地理图,表明古亚洲洋、古秦岭-祁连洋俯冲伊始,不足以使盆地整体抬升,全球海平面上升期盆地内存在沉积记录;同时揭示平凉期沉积物才是鄂尔多斯盆地奥陶纪风化壳被剥蚀的主要物质。 展开更多
关键词 构造-沉积分异作用 凝灰岩 锆石U-Pb定年 同沉积断裂 岩相古地理
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胶北地体新太古代晚期变基性火山岩年代学、地球化学和Hf-O同位素研究
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作者 智云宝 孙斌 +5 位作者 李晓 李秀章 杨超 郝兴中 朱学强 李风华 《岩石学报》 北大核心 2026年第1期207-224,共18页
胶北地体位于华北克拉通东部,经历了中太古代(~2.9Ga)和新太古代(~2.7Ga和~2.5Ga)多期次岩浆活动。太古宙岩石主要由花岗质片麻岩和变辉长岩组成,含少量变质表壳岩包体或透镜体。本研究拟通过新的锆石SHRIMP U-Pb定年、全岩地球化学和H... 胶北地体位于华北克拉通东部,经历了中太古代(~2.9Ga)和新太古代(~2.7Ga和~2.5Ga)多期次岩浆活动。太古宙岩石主要由花岗质片麻岩和变辉长岩组成,含少量变质表壳岩包体或透镜体。本研究拟通过新的锆石SHRIMP U-Pb定年、全岩地球化学和Hf-O同位素分析来揭示其岩石成因和构造背景。锆石SHRIMP U-Pb定年获得变基性岩火山岩岩浆锆石年龄为2524±22Ma以及新太古代晚期(2494±9Ma)构造热事件的影响,从而限定了变基性火山岩形成时代在2494~2507Ma之间,归属于新太古代晚期的胶东岩群,岩石具拉斑玄武岩成分特征,在岩浆演化过程中经历了橄榄石和单斜辉石的结晶分离。分析样品的全岩成分显示其具低-中等SiO_(2)含量(50.39%~52.01%)和较高Mg值(Mg^(#)=41~67),富集轻稀土元素(LREE)和大离子亲石元素(LILE)Rb、Ba、Pb,亏损重稀土元素(HREE)和高场强元素(HFSE)Nb、Ta、Ti,无明显Eu异常。锆石ε_(Hf)(t)值介于+1.22~+6.0,δ^(18)O值介于3.46‰~6.59‰,这些地球化学特征显示出典型的俯冲相关的岛弧特征,表明变基性火山岩源自亏损地幔的部分熔融。新太古代晚期(~2.5Ga)大量TTG、赞岐岩和富钾花岗岩组合,显示出强烈的壳幔相互作用和地壳物质再循环,显示华北克拉通在新太古代晚期完成初始克拉通化。 展开更多
关键词 变基性火山岩 锆石SHRIMP U-Pb定年 地球化学 构造演化 胶北地体
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长距离带式输送机新型起动曲线及其动态特性分析
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作者 袁媛 寇俊雄 周利东 《机械传动》 北大核心 2026年第1期155-162,191,共9页
【目的】针对长距离带式输送机起动过程中的纵向振动问题,基于输送带黏弹特性分析,构建了带式输送机的动力学方程。以实际工程中的长距离带式输送机为例,利用AMESim平台搭建了动力学仿真模型,旨在探究起动过程中的加速度曲线及最佳加载... 【目的】针对长距离带式输送机起动过程中的纵向振动问题,基于输送带黏弹特性分析,构建了带式输送机的动力学方程。以实际工程中的长距离带式输送机为例,利用AMESim平台搭建了动力学仿真模型,旨在探究起动过程中的加速度曲线及最佳加载时间。【方法】首先,分析了常见起动曲线对输送带动张力的影响,提出一种“正弦+抛物线”的新型组合起动曲线;其次,通过引入爬行段和调整预起动阶段的速度,对该曲线进行了优化;最后,对比分析了不同加载时间下输送带的张力变化规律。【结果】结果表明,在起动过程中采用优化后的“正弦+抛物线”组合起动曲线后,输送带产生的最大张力值较常用的正弦加速度曲线降低了5.8%;在系统稳定运行后加载物料,可有效降低输送带受到的张力冲击,从而延长设备使用寿命。 展开更多
关键词 带式输送机 起动曲线 AMESIM 最大张力值 动态特性 负载
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辽宁生铁岭稀土矿磁铁变粒岩年代学和地球化学特征 及其矿床成因类型初探
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作者 鞠楠 刘博 +7 位作者 马婧轩 辛后田 刘欣 伍月 施璐 樊金虎 杨高 曾维顺 《地学前缘》 北大核心 2026年第2期195-222,共28页
辽宁中部生铁岭稀土矿床产于古元古代胶辽吉构造带南辽河群内,有关其赋矿层位里尔峪组磁铁变粒岩研究程度偏低。本文对生铁岭稀土矿磁铁变粒岩开展岩相学、锆石和独居石U-Pb年代学和微量元素分析、全岩地球化学研究,以约束其岩石成因和... 辽宁中部生铁岭稀土矿床产于古元古代胶辽吉构造带南辽河群内,有关其赋矿层位里尔峪组磁铁变粒岩研究程度偏低。本文对生铁岭稀土矿磁铁变粒岩开展岩相学、锆石和独居石U-Pb年代学和微量元素分析、全岩地球化学研究,以约束其岩石成因和构造背景,并对其成因类型进行初步探讨。岩相学、背散射图像、电子探针和独居石激光剥蚀电感耦合等离子体质谱仪(laser ablation inductively coupled plasma mass spectrometry,LA-ICP-MS)原位微区微量元素研究结果显示,生铁岭稀土矿产于里尔峪组磁铁斜长变粒岩和含磁铁黑云斜长变粒岩中,主要稀土矿物为独居石、磷钇矿和磷灰石等。锆石和独居石U-Pb年代学结果表明,生铁岭磁铁变粒岩最大沉积年龄为1.95 Ga(岩浆成因碎屑锆石),变质作用发生在1.90~1.87 Ga(变质锆石和独居石)。磁铁变粒岩Th-Sc-Zr/10和Th-Co-Zr/10图解显示样品落入大陆岛弧区域,结合区域上已发表的辽河群变沉积岩资料,认为其原岩可能是俯冲作用下的岛弧相关沉积。磁铁变粒岩样品的变质作用时限(1.90~1.87 Ga)与区域上辽河群中普遍记录的区域变质作用时限一致,形成于胶辽吉构造带形成过程中的弧陆碰撞作用。综合磁铁变粒岩的稀土元素赋存特征、岩石成因和构造产出环境,推测其成因类型应为火山沉积变质型。该认识为辽宁地区寻找火山沉积变质型稀土矿提供了理论依据,产自辽河群里尔峪组的磁铁变粒岩是重要找矿标志。 展开更多
关键词 稀土矿床 变粒岩 里尔峪组 锆石和独居石U-Pb年龄 火山沉积变质型 生铁岭
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大兴安岭加不斯钽铌稀有金属矿床LA-ICP-MS锆石和铌钽矿物U-Pb年代学特征及成矿指示意义
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作者 丁建华 张勇 +4 位作者 叶会寿 余金杰 付雪瑞 吴胜华 张彤 《地质学报》 北大核心 2026年第1期145-167,共23页
加不斯钽铌稀有金属矿是位于大兴安岭稀有金属成矿带西南部的一处大型钽矿床,伴生有Nb、Li、Rb、Cs矿化。本文通过系统的岩相学、岩石地球化学及铌钽矿LA-ICP-MS U-Pb年代学工作,对矿床成岩成矿机制进行了研究。加不斯成矿花岗岩主要为... 加不斯钽铌稀有金属矿是位于大兴安岭稀有金属成矿带西南部的一处大型钽矿床,伴生有Nb、Li、Rb、Cs矿化。本文通过系统的岩相学、岩石地球化学及铌钽矿LA-ICP-MS U-Pb年代学工作,对矿床成岩成矿机制进行了研究。加不斯成矿花岗岩主要为黄玉锂白云母碱长花岗岩和锂白云母钠长花岗岩,富硅、铝和碱,贫铁和镁,尤其贫钛和磷,属过铝质高钾钙碱性系列;相对富集Rb、Th、Nd、Zr,亏损Ba、Nb、Sr、P,强烈亏损Ti;稀土元素总量较低,平均47.97×10^(-6),具有强烈负Eu异常和显著的M型“四分组”效应;成矿花岗岩的Zr/Hf=2.58~3.47,Nb/Ta=0.3~0.39,表明成矿岩体经历了强烈的分异作用,属高分异花岗岩。矿区矿石矿物主要为细晶石、铌钽锰矿和锂白云母,铷(铯)主要以类质同象赋存于锂白云母和铌钽矿物中。矿区不含矿的黑云母(角闪)花岗岩中锆石的^(206)Pb/^(238)U加权平均年龄为144.0±1.0 Ma(2σ,n=16,MSWD=1.3),反映了围岩那仁乌拉岩体的成岩年龄。成矿的黄玉锂白云母碱长花岗岩矿石中岩浆成因铌钽矿物的^(206)Pb/^(238)U加权平均年龄为120.7±0.2 Ma(2σ,n=17,MSWD=6),代表了铌钽矿的成矿年龄,也代表了成矿岩体的成岩年龄为早白垩世晚期,成岩成矿与蒙古-鄂霍茨克洋中侏罗世闭合后的岩石圈伸展有关。笔者认为,加不斯钽铌稀有金属矿床是高分异演化的花岗岩熔体和富Li、F等挥发分流体共同作用和制约的结果,成矿可以划分为两个阶段,第一阶段为岩浆原始结晶阶段,以Ta、Nb矿化为主,第二阶段为热液流体的自交代阶段,以Li、Rb、Cs矿化为主。围绕着那仁乌拉岩体,仍然具有找到同类型稀有金属矿床的潜力。 展开更多
关键词 高分异花岗岩 稀有金属 铌钽矿物U-Pb年龄 加不斯 大兴安岭
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闸门慢速启动下水泵机组起动过程水力稳定性研究
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作者 徐辉 王楚怡 +3 位作者 陈会向 阚阚 冯建刚 张睿 《农业机械学报》 北大核心 2026年第3期252-260,共9页
为探究水泵机组起动过程中,闸门慢速启动对机组水力稳定性的影响,建立了泵机组全过流几何模型,采用铺层网格和动网格技术实现闸门运动和转轮旋转,分别对不同闸门启动速度下的水泵机组起动过程开展了三维数值模拟。设置3种不同闸门启动... 为探究水泵机组起动过程中,闸门慢速启动对机组水力稳定性的影响,建立了泵机组全过流几何模型,采用铺层网格和动网格技术实现闸门运动和转轮旋转,分别对不同闸门启动速度下的水泵机组起动过程开展了三维数值模拟。设置3种不同闸门启动速度的控制方案,从外部参数变化、压力脉动特性和内流特性3个角度探究闸门慢速启动对水泵起动过程水力稳定性所产生的影响,结合熵产理论量化了不同区域的能量损失,进一步分析了泵起动过程中的能量损失变化。研究结果表明,不同控制方案在外部参数、压力波动、水头损失等方面表现出相似的演变趋势,但在时间进程和变化幅值上存在差异。在起动过程中,减慢闸门启动速度将减慢流量变化,减慢外特性参数的回落速率,方案1、2、3的进口流量分别于12.2、25.4、56.4 s达到运行流量值;增大转矩和轴向力的波动幅值,同时增大机组内压力峰值和压力脉动峰峰值。水头损失方面,减慢闸门启动速度对能量损失的影响具有明显的时域双重性:加速阶段以增损为主,而后期则转为抑损。 展开更多
关键词 水泵机组 快速闸门 起动过程 熵产理论 三维数值模拟
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船用预混氨氢发动机冷启动性能分析
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作者 王忠诚 成建山 +2 位作者 郭浩 梁鹏 李升龙 《船海工程》 北大核心 2026年第1期161-166,共6页
为改善氨燃料在船舶发动机中的冷启动困难问题,以MAN公司L23/30H型柴油机为目标机型构建三维仿真模型,采用掺混氢气的方式来改善氨燃料的燃烧,在进气道内预混氨氢燃料,基于CONVERGE软件数值模拟计算方法,探究掺氢比和点火时刻对发动机... 为改善氨燃料在船舶发动机中的冷启动困难问题,以MAN公司L23/30H型柴油机为目标机型构建三维仿真模型,采用掺混氢气的方式来改善氨燃料的燃烧,在进气道内预混氨氢燃料,基于CONVERGE软件数值模拟计算方法,探究掺氢比和点火时刻对发动机冷启动性能的影响。结果表明,在当量比为0.5,进气温度为340 K条件下,随着掺氢比增加,指示热效率增大,缸内燃烧效果提升显著,但NO_(x)排放也增加4.7倍;在15%掺氢比时,点火时刻最晚为10℃A BTDC时可正常点火,提前点火时刻至16℃A BTDC时,指示热效率最大,缸内压力峰值接近发动机所允许的最大压力,最有利于点火燃烧。 展开更多
关键词 船舶 氨氢发动机 冷启动 燃烧 排放
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