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The fast quality control strategy for P-wave receiver functions based on AlexNet and wiggle plot
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作者 Jiajun Chen Chuntao Liang Rui Xu 《Earthquake Science》 2026年第2期140-155,共16页
This paper proposes a fast quality control strategy for P-wave receiver functions based on AlexNet and wiggle plots.Receiver functions are essential tools in seismology,particularly for analyzing seismic wave propagat... This paper proposes a fast quality control strategy for P-wave receiver functions based on AlexNet and wiggle plots.Receiver functions are essential tools in seismology,particularly for analyzing seismic wave propagation and subsurface structures,such as the crust and upper mantle.However,the quality control of receiver functions is often a tedious,time-consuming process.In this study,we transform the time series classification problem of receiver function quality control problem into an image classification task by plotting receiver functions as wiggle diagrams and using the deep learning model AlexNet for binary classification to distinguish between“good”and“bad”receiver functions.The model achieved an accuracy of 92.55%on the testing set and demonstrated strong generalization performance with an accuracy of 89.23%on receiver functions of another seismic network(Sichuan Provincial Permanent Seismic Network).While maintaining strong performance,the model is capable of processing approximately 32 receiver function wiggle plots per second on an NVIDIA GeForce RTX 4050.The results show that the proposed feature mapping strategy significantly improves the efficiency and accuracy of receiver function quality control,making it a valuable tool for practical applications.Future work will focus on expanding the dataset and optimizing model performance for broader seismic data applications. 展开更多
关键词 receiver function automated quality control deep learning AlexNet wiggle plot
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Post-fire cyclic behavior of reinforced concrete shear walls 被引量:5
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作者 刘桂荣 宋玉普 曲福来 《Journal of Central South University》 SCIE EI CAS 2010年第5期1103-1108,共6页
The effects of fire exposure,reinforcement ratio and the presence of axial load under fire on the seismic behavior of reinforced concrete(RC) shear walls were investigated.Five RC shear walls were tested under low cyc... The effects of fire exposure,reinforcement ratio and the presence of axial load under fire on the seismic behavior of reinforced concrete(RC) shear walls were investigated.Five RC shear walls were tested under low cyclic loading.Prior to the cyclic test,three specimens were exposed to fire and two of them were also subjected to a constant axial load.Test results indicate that the ultimate load of the specimen with lower reinforcement ratio is reduced by 15.8%after exposure to elevated temperatures.While the reductions in the energy dissipation and initial stiffness are 59.2%and 51.8%,respectively,which are much higher than those in the ultimate load.However,this deterioration can be slowed down by properly increasing reinforcement due to the strength and stiffness recovery of steel bars after cooling.In addition,the combined action of elevated temperatures and axial load results in more energy dissipation than the action of fire exposure alone. 展开更多
关键词 shear wall reinforced concrete post-fire seismic behavior low cyclic loading
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Short-term effects of post-fire mulching with straw or wood chips on soil properties of semi-arid forests 被引量:1
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作者 Manuel Esteban Lucas Borja Demetrio Antonio Zema 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第6期1777-1790,共14页
Few studies have compared the variability of soil properties using different types of mulches in semi-arid forests.This study evaluated the changes in physico-chemical soil properties in a semi-arid forest of Central ... Few studies have compared the variability of soil properties using different types of mulches in semi-arid forests.This study evaluated the changes in physico-chemical soil properties in a semi-arid forest of Central Eastern Spain,where straw and pine wood chips were distributed as mulch three months after a wildfire.Soils were sampled under burned and unmulched and burned and mulched plots three and nine months after the treatments.The data was processed using Principal Component Analysis(PCA)and Analytical Hierarchical Cluster Analysis(AHCA).Mulching with straw or wood chips did not have any significant effects on the texture and chemical properties of burned sites few months after the treatment.In contrast,significant changes are expected over time in organic matter,nutrients and many ions.There were no significant differences in soil properties between the two mulches.These low changes were confirmed by PCA coupled with AHCA,which did not show a clear distinction among the three soil conditions.However,a noticeable and significant variability of many of these properties over time was evident.This study shows that mulching does not degrade of soil properties in the short-term after a wildfire and after post-fire treatments,and thus helps protect semi-arid forest ecosystems against the negative impacts of high-severity fires. 展开更多
关键词 post-fire management High-severity fire ARIDISOLS Erosion Vegetal residues incorporation Soil degradation
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Tree Planting:How Fast Can It Accelerate Post-fire Forest Restoration?——A Case Study in Northern Da Hinggan Mountains,China 被引量:1
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作者 LI Xiuzhen HE Hong S +3 位作者 WANG Xugao XIE Fuju HU Yuanman LI Yuehui 《Chinese Geographical Science》 SCIE CSCD 2010年第6期481-490,共10页
In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferou... In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferous tree planting had been conducted to accelerate forest restoration.To study the long term effect of these activities on forest recovery,we used a simulation modeling approach to study long-term(300 years) forest dynamics under current planting and natural regeneration scenarios.Results indicate that under tree planting scenario in the severely burned area,the dominant species Dahurian larch(Larix gmelinii) can reach pre-fire level(60% of the area) within 20 years and the maximum abundance can reach nearly 90% within 100 years.While under natural regeneration scenario,it needs about 250 years to reach its pre-fire level.From the perspective of timber production,tree planting can bring twice as much timber volume as that under natural regeneration within 300 years,which is the average longevity of L.gmelinii.It needs about 70 years to reach the timber volume of pre-fire level under the planting scenario,whereas it requires at least 250 years to reach the timber volume of pre-fire level under natural regeneration scenario.Another dominant species Asian White birch(Betula platyphylla) responded negatively to the planting of coniferous species.In general,tree planting of coniferous species after fire can greatly accelerate forest restoration in terms of species abundance and target timber volume,with desirable ecological and economic returns. 展开更多
关键词 tree planting natural regeneration post-fire forest restoration species abundance timber volume LANDIS model
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Salvage logging versus natural regeneration post-fire practices in a forest: Soil chemical and microbial aspects 被引量:1
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作者 Orit Ginzburg Yosef Steinberger 《Open Journal of Ecology》 2012年第1期29-37,共9页
The increase in forest-wildfire events around the world has revived the old debate regarding the practice of salvage logging and its effectiveness in comparison to the unlogged, natural regeneration of burned forests.... The increase in forest-wildfire events around the world has revived the old debate regarding the practice of salvage logging and its effectiveness in comparison to the unlogged, natural regeneration of burned forests. Since the logging of burned trees may have undesirable outcomes in soil systems, such as soil compaction and nutrient losses, these changes could further cause disturbances to soil microbial-community activity. The aim of this study was to examine chemical and biological changes in soil under two post-fire practices: salvage logging and unlogged, natural regeneration of burned areas, in the recently burned Byria Forest in Israel. Results indicated that salvage logging had a short- lived effect on soil chemical and biological properties that was confined mostly to the first year after logging. Soil moisture was greatly affected by salvage logging, and drier conditions were found in the logged compared to the unlogged burned areas. Moreover, logging had a negative effect on microbial biomass, with reduced biomass in the logged compared to unlogged areas, which was more evident during the first year after fire. These findings support the recommendations in the literature to postpone post-fire practices such as logging or, in turn, to combine the two practices in order to create a mosaic of burned-logged and burned-naturally regenerated areas. 展开更多
关键词 MICROBIAL community Natural REGENERATION post-fire practice SALVAGE LOGGING WILDFIRE
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Evaluation of the post-fire erosion and flood control works in the area of Cassandra(Chalkidiki, North Greece) 被引量:1
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作者 Kastridis Aristeidis Kamperidou Vasiliki 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第1期209-217,共9页
We quantified morphological and hydrographical characteristics of two drainage basins(Chanioti and N. Skioni) on Cassandra peninsula of Chalkidiki(North Greece), and evaluated the effectiveness of post-fire flood ... We quantified morphological and hydrographical characteristics of two drainage basins(Chanioti and N. Skioni) on Cassandra peninsula of Chalkidiki(North Greece), and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers(LEBs), log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed. 展开更多
关键词 Erosion Catchment Contour branch barrier Flood Log erosion barrier post-fire management
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Below-ground growth characteristics of 13-year-old Pinus densiflora on different contour conditions in a post-fire plantation in Samcheuk,Korea
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作者 Do-Hyun Kim Sung-Jun Na +3 位作者 Sea-Hyun Kim Ewane Basil Ewane Dae-Bong Kang Do-Hyung Lee 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第5期1007-1018,共12页
We estimated the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions by comparing and analyzing the vertical and horizontal distributions of below-ground... We estimated the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions by comparing and analyzing the vertical and horizontal distributions of below-ground roots on each contour. The main roots at the south-facing slope (SS) developed in a long and straight form, and those on the north-facing slope (NS) in a twisted form. The side roots developed more than the main roots on the Ridge. The depth of taproots decreased in the following order: SS > NS > Ridge. The roots on the SS developed in a pile-form root structure whereas those in the Ridge and NS developed concentrically near the root collar. The amount of root development decreased in the following order: SS > NS > Ridge. The ratio of fine roots from the whole-root development decreased in the following order: Ridge > SS > NS. These results can guide considerations of growth differences according to the planting contour conditions for future establishment of P. densiflora artificial plantations. 展开更多
关键词 Pinus densiflora Growth characteristics Contour conditions post-fire plantation WILDFIRE Restoration Soil depth
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Biomass growth characteristics of 13-year-old Pinus densiflora S.et Z.in a post-fire plantation on different contour conditions in Samcheuk,Korea
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作者 Lee Ju-Hyoung Lee Do-Hyung +2 位作者 Kim Do-Hyun Park Jin-Hwa KimJae-Hee 《Journal of Mountain Science》 SCIE CSCD 2016年第7期1238-1244,共7页
We used preliminary data to estimate the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions. We compared the growth of P. densiflora on a south-facing s... We used preliminary data to estimate the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions. We compared the growth of P. densiflora on a south-facing slope(Ssth), north-facing slope(Snth) and ridge area(Ridge), using 7 trees selected from each stand aspect. The tree height, diameter and growth volume were measured and the dry weight of each plant part were compared and analyzed. The results revealed that the total dry weight was highest on Ssth(5992.3 g), followed by Snth(4833.2 g) and lowest on Ridge(3160.1 g). The height growth was highest on Snth(285.8 cm), followed by Ssth(274.5 cm) and lowest on Ridge(211.5 cm). The diameter growth was greatest on Ssth(7.37 cm), followed by Snth(7.10 cm) and lowest on Ridge(5.72 cm). The volume growth was highest on Ssth(4257.7 cm3), followed by Snth(3750.7 cm3) and lowest on Ridge(2093.7 cm3). Therefore, we should consider and include the concept of slope orientation together with differences in habitat environments in afforestation projects when creating artificial forests with P. densiflora. These study results can serve as important preliminary data for future establishment of artificial forest of P. densiflora in a post-fire plantation. 展开更多
关键词 Pinus densiflora Growth characteristics Contour conditions Planted stand post-fire plantation
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小区播种机全自动弹匣式供种装置的设计与试验 被引量:1
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作者 刘春旭 张范良 +5 位作者 芦磊 朱炫铭 徐涛 李存斌 李蕾 邢璐露 《农机化研究》 北大核心 2026年第1期87-94,共8页
目前,大多数采用弹匣式供种装置的小区播种机在作业过程中都需要人工辅助完成种盒接续工作,由此导致辅助作业人员工作强度大,以及载人作业存在安全隐患的问题。为此,创新设计了一种全自动弹匣式供种装置。该装置包括5套相互独立且层叠... 目前,大多数采用弹匣式供种装置的小区播种机在作业过程中都需要人工辅助完成种盒接续工作,由此导致辅助作业人员工作强度大,以及载人作业存在安全隐患的问题。为此,创新设计了一种全自动弹匣式供种装置。该装置包括5套相互独立且层叠配置的弹匣式供种单元和1个总控单元,每套供种单元负责完成1个种盒组的装载、推送、抛盒和复位等步骤,总控单元响应上位机发出的供种信号,控制各套供种单元协同工作,有序衔接,从而取代人工作业。阐述了该装置的总体结构和关键部件的设计要点,分析了不同设计方案对于供种单元自身高度和供种单元层间高度的影响,研究了采用多个传感器协同检测以实现推送支架定位和种盒定位的技术细节,介绍了装置的主要工作流程、控制系统的硬件组成和软件设计架构。田间试验结果表明,该装置可在不同的作业速度下自动完成5个种盒组的连续推送,上种遗漏率为0,破碎率为0.072%,混种率为0,装置故障率为0,能够满足小区播种机全自动连续供种的作业需求。 展开更多
关键词 小区播种机 全自动 弹匣式 供种 层叠
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Assessing the effect of plot size on species diversity in a mixed oriental beech forest
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作者 Narges Kardgar Ramin Rahmani +1 位作者 Habib Zare Somayeh Ghorbani 《Journal of Forestry Research》 2025年第1期209-222,共14页
Plant species diversity is one of the most widely used indicators in ecosystem management.The relation of species diversity with the size of the sample plot has not been fully determined for Oriental beech forests(Fag... Plant species diversity is one of the most widely used indicators in ecosystem management.The relation of species diversity with the size of the sample plot has not been fully determined for Oriental beech forests(Fagus orientalis Lipsky),a widespread species in the Hyrcanian region.Assessing the impacts of plot size on species diversity is fundamental for an ecosystem-based approach to forest management.This study determined the relation of species diversity and plot size by investigating species richness and abundance of both canopy and forest floor.Two hundred and fifty-six sample plots of 625 m^(2) each were layout in a grid pattern across 16 ha.Base plots(25 m×25 m)were integrated in different scales to investigate the effect of plot size on species diversity.The total included nine plots of 0.063,0.125,0.188,0.250,0.375,0.500,0.563,0.750 and 1 ha.Ten biodiversity indices were calculated.The results show that species richness in the different plot sizes was less than the actual value.The estimated value of the Simpson species diversity index was not significantly different from actual values for both canopy and forest floor diversity.The coefficient of variation of this index for the 1-ha sample plot showed the lowest amount across different plot sizes.Inverse Hill species diversity was insignificant difference across different plot sizes with an area greater than 0.500 ha.The modified Hill evenness index for the 1-ha sample size was a correct estimation of the 16-ha for both canopy and forest floor;however,the precision estimation was higher for the canopy layer.All plots greater than 0.250-ha provided an accurate estimation of the Camargo evenness index for forest floor species,but was inaccurate across different plot sizes for the canopy layer.The results indicate that the same plot size did not have the same effect across species diversity measurements.Our results show that correct estimation of species diversity measurements is related to the selection of appropriate indicators and plot size to increase the accuracy of the estimate so that the cost and time of biodiversity management may be reduced. 展开更多
关键词 Species diversity Oriental beech forest Sample plot size Richness EVENNESS
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悬挂式全电驱小区精量播种机控制系统的设计与试验 被引量:1
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作者 东忠阁 程睿 +4 位作者 吴泽全 赵尔迪 侯云涛 李占成 蔡晓华 《农机化研究》 北大核心 2026年第3期70-77,共8页
为实现小区播种机高效清种与充种,提升区块行长、区间间隔与播种株距的控制精度,并完成多作业行区块的精确对齐,设计了一套悬挂式全电驱小区播种机智能控制系统。该系统集成RTK差分定位、种盒自动传送、排种器伺服驱动、快速清充种、电... 为实现小区播种机高效清种与充种,提升区块行长、区间间隔与播种株距的控制精度,并完成多作业行区块的精确对齐,设计了一套悬挂式全电驱小区播种机智能控制系统。该系统集成RTK差分定位、种盒自动传送、排种器伺服驱动、快速清充种、电驱变量施肥和人机交互等模块,构建了一套完整的精密播种控制体系。针对地轮滑移和北斗RTK定位更新频率低的问题,提出了动态校正算法,通过RTK信号对地轮速度进行在线辨识与滑移补偿,提升了行进测速和株距、播种控制精度;通过台架试验优化清充种控制时序,提升清种与充种效率;田间试验结合打标装置对小区行长、区间间隔、不同作业方向区块对齐精度和株距一致性进行验证,结果表明:在3.0 km/h作业速度下,品种隔离成功率达到100%,播种株距合格率为93.2%,小区行长和区间道控制误差分别小于5 cm和2 cm,各行区块对齐偏差不超过6 cm。研究为提高小区育种播种的精度与作业可靠性提供了有效的技术支撑。 展开更多
关键词 小区播种机 精准控制 动态校正 快速清充种 控制时序
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Relationship between topographic variables and live aboveground tree biomass on a large temperate forest plot
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作者 Dawn Lemke Luben Dimov +3 位作者 Helen Czech Patience Knight William Finch Richard Condit 《Forest Ecosystems》 2025年第5期813-821,共9页
Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tre... Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tree biomass within a fully censused 20 ha forest plot in a temperate forest of northern Alabama,USA.We evaluated the relationship between biomass and topography using ridge and valley landforms along with digitally derived moisture and solar radiation indices.Every live woody stem over 1 cm diameter at breast height within this plot was mapped,measured,and identified to species in 2019-2022,and diameter data were used along with speciesspecific wood density to map the aboveground biomass at the scale of 20 m×20 m quadrats.The aboveground tree biomass was 211 Mg·ha^(-1).Other than small stream areas that experienced recent natural disturbances,the total stand biomass was not associated with landform or topographic indices.Dominant species,in contrast,had strong associations with topography.American beech(Fagus grandifolia)and yellow-poplar(Liriodendron tulipfera)dominated the valley landform,with 37% and 54% greater biomass in the valley than their plot average,respectively.Three other dominant species,white oak(Quercus alba),southern shagbark hickory(Carya carolinaeseptentrionalis),and white ash(Fraxinus americana),were more abundant on slopes and benches,thus partitioning the site.Of the six dominant species,only sugar maple(Acer saccharum)was not associated with landform.Moreover,both topographic wetness and potential radiation indices were significant predictors of dominant species biomass within each of the landforms.The study highlights the need to consider species when examining forest productivity in a range of site conditions. 展开更多
关键词 Aboveground tree biomass Paint rock forest dynamics plot Topographic wetness index(TWI) Potential radiation Landform position index
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小区玉米籽粒联合收获机的设计与试验 被引量:1
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作者 王彬 董学虎 +1 位作者 张培 陈兴洲 《农机化研究》 北大核心 2026年第1期48-55,共8页
为了改善国内小区玉米育种收获机械装备缺乏、收获过程过于依靠人工的现状,设计了一种自走式小区玉米籽粒联合收获机。该机采用摘穗板-拉茎辊式摘穗、剥皮脱粒装置柔性脱粒,实现了一次性完成摘穗-剥皮-脱粒的作业要求。使用Design-Exper... 为了改善国内小区玉米育种收获机械装备缺乏、收获过程过于依靠人工的现状,设计了一种自走式小区玉米籽粒联合收获机。该机采用摘穗板-拉茎辊式摘穗、剥皮脱粒装置柔性脱粒,实现了一次性完成摘穗-剥皮-脱粒的作业要求。使用Design-Expert软件建立了因素与指标的响应面数学模型,分析了各因素与评价指标之间的关系并对影响因素进行优化。试验结果表明,各因素对果穗损失率影响的显著性顺序:摘穗台高度>前进速度>脱粒辊转速;各因素对籽粒破损率影响的显著性顺序:脱粒辊转速>前进速度>摘穗台高度;各因素对作业生产率影响的显著性顺序:前进速度>脱粒辊转速>摘穗台高度。各试验因素最优参数组合为机具前进速度2.12 m/s、摘穗台高度40 cm、脱粒辊转速700 r/min,此时果穗损伤率为0.26%、籽粒破损率为1.06%、作业生产率为0.20 hm^(2)/h。验证试验结果表明,果穗损伤率和籽粒破损率的实测值相对于预测值误差分别为0.08%和0.15%,预测模型可靠。研究结果可为玉米籽粒的机械化收获提供依据。 展开更多
关键词 小区育种 玉米收获 柔性脱粒 回归分析
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小区播种机发展现状与关键部件技术分析
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作者 朱炫铭 刘春旭 +5 位作者 徐涛 梁玉成 芦磊 张范良 周魏岩 王雷 《农机化研究》 北大核心 2026年第6期294-300,共7页
小区播种机是一种专门用于新品种培育、良种繁育、品种对比试验的设备,精准的育种试验能够创制高产、高附加值的农产品品种,其发展不仅关系到农业科技的进步和国家粮食安全,还直接影响农业生产的效率和作物品种的质量。相较于人工或半... 小区播种机是一种专门用于新品种培育、良种繁育、品种对比试验的设备,精准的育种试验能够创制高产、高附加值的农产品品种,其发展不仅关系到农业科技的进步和国家粮食安全,还直接影响农业生产的效率和作物品种的质量。相较于人工或半人工的育种,小区播种机在保障播种的播深一致性和播种均匀性上更具优势,是保障育种试验精准度与科学严谨性的关键环节。本文通过对国内外小区播种机的发展现状进行概述,列举近年来国内外主流机型的性能与特点,结合我国小区播种机研发现状,对小区供种装置、小区排种装置、小区清种装置等关键部件技术原理进行了分析,阐述了小区播种机与大田播种机的适配差异,指出了小区播种机的发展趋势。同时,针对小区播种机在技术、工艺、推广应用和农机农艺融合等方面存在的不足提出建议,以期为育种机械领域的产品研发提供参考。 展开更多
关键词 小区播种机 供种装置 排种装置 清种装置
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散点图解析策略之模型对照法
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作者 景永明 申继红 樊好义 《实用心电与临床诊疗》 2026年第1期88-96,共9页
本研究利用《几何画板》软件的动态作图与轨迹跟踪功能,构建了常用散点图的系列数学模型。在二维作图平台制作时间散点图、Lorenz散点图及差值散点图的数学模型;在三维作图平台完成三维Lorenz散点图的模型制作。三维Lorenz散点图的xyz... 本研究利用《几何画板》软件的动态作图与轨迹跟踪功能,构建了常用散点图的系列数学模型。在二维作图平台制作时间散点图、Lorenz散点图及差值散点图的数学模型;在三维作图平台完成三维Lorenz散点图的模型制作。三维Lorenz散点图的xyz面与二维差值散点图之间的相互转化模型,表明三维Lorenz散点图的xyz面等价于二维差值散点图,而三维Lorenz散点图的xOy面、yOz面就是二维Lorenz散点图。这从侧面证实了二维Lorenz散点图与二维差值散点图的优势互补关系。散点图的数学模型不仅能高精度模拟临床记录的真实心电散点图,还可演绎生成罕见、特殊病例的图形。通过调整模型初始参数,能够系统阐释不同类型心律失常散点图的形成机制。基于几何画板的模型对照法超越了传统依赖直觉与经验的分析模式,为心电散点图研究提供了可推理、可验证的数学框架。该方法不仅深化了对散点图背后电生理机制的理解,有助于建立整体性心律观,也为从新的视角认识已知疾病和发现新的疾病特征提供了工具。 展开更多
关键词 动态心电图 心律失常 心电散点图 时间散点图 LORENZ散点图 差值散点图 三维Lorenz散点图 模型对照法 几何画板
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基于北斗RTK的小区精量播种机区间控制算法研究
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作者 东忠阁 吴泽全 +4 位作者 叶岩 侯云涛 李占成 程睿 蔡晓华 《农机化研究》 北大核心 2026年第7期202-210,共9页
小区播种是作物育种试验的关键环节,其对作业精度的要求极为严苛,不仅需要在行进中精准控制小区与间隔道的交替区间,还要保证种子实际落地点与理论空间边界对齐,以实现小区长度的准确计量。针对传统方法在边界识别、长度控制和系统延迟... 小区播种是作物育种试验的关键环节,其对作业精度的要求极为严苛,不仅需要在行进中精准控制小区与间隔道的交替区间,还要保证种子实际落地点与理论空间边界对齐,以实现小区长度的准确计量。针对传统方法在边界识别、长度控制和系统延迟补偿等方面不足的问题,提出了一种融合北斗RTK厘米级定位、投影累加动态状态切换与落点预测的协同控制算法。首先,提出投影累加与动态状态切换触发算法,通过构建“播种-间隔道”双状态机模型,并采用沿航向投影的距离累加与动态状态判断机制,实现了小区与间隔道边界的精准识别与模式切换;然后,提出基于运动学的前馈落点预测模型,建立种子落点滞后距离与实时速度的映射关系,实现了播种动作的提前触发,消除种子落点偏差影响,保障以实际落种点为基准的小区与间隔道长度计量的真实性。田间试验结果表明:示踪标记对比试验中,投影累加算法100 m累计误差仅3.5 cm,较传统欧氏距离累加算法改善81.2%;状态切换试验,0.5~3.0 km/h速度范围内小区长度平均绝对偏差1.8~3.2 cm,切换成功率100%;落点预测试验,首粒种子落点与理论起点平均偏差3.3 cm,标准差2.5 cm。该研究为实现高精度、自动化的小区播种作业提供了技术解决方案,显著提升了育种试验的准确性与可比性。 展开更多
关键词 小区精量播种 电控系统 RTK定位 投影累加 状态切换 落点预测
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血细胞分析仪WDF和WNB散点图在血小板数量检测质量管理中的应用
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作者 张宁 何晓璇 孟欣 《现代检验医学杂志》 2026年第2期187-191,共5页
目的探讨并验证白细胞WDF通道散点图(WDF)和白细胞WNB通道散点图(WNB)在监测血液微小凝集、大血小板及血小板聚集中的价值。方法收集2023年4~12月西安交通大学第一附属医院EDTA-K2血液样本1788例,Mindray BC-6800 Plus全自动血细胞分析... 目的探讨并验证白细胞WDF通道散点图(WDF)和白细胞WNB通道散点图(WNB)在监测血液微小凝集、大血小板及血小板聚集中的价值。方法收集2023年4~12月西安交通大学第一附属医院EDTA-K2血液样本1788例,Mindray BC-6800 Plus全自动血细胞分析仪触发血小板聚集报警,或血小板直方图异常,或WDF、WNB散点图Ghost区域异常时,使用MC-80全自动血细胞形态学分析仪判断不同异常报警与血液微小凝集、血小板聚集及大血小板的关系。结果173例WDF散点图Ghost区域异常样本,血小板数量减低,与重新采集血液前比较,重新采集血液后血小板数量明显增高,差异具有统计学意义(Z=-10.009,P<0.05)。1252例WNB散点图Ghost区域异常的样本,MC-80全自动血细胞形态学分析系统镜检提示大血小板1035例(占比82.67%)、血小板聚集217例(占比17.33%),平均血小板体积(MPV)、大血小板比率(P-LCR)、血小板分布宽度标准差(PDW-SD)血小板聚集样本明显低于大血小板样本,差异具有统计学意义(t=9.785、8.682、8.344,均P<0.05)。血小板压积(PCT)、大血小板数量(P-LCC)血小板聚集样本高于大血小板样本,差异无统计学意义(t=-1.490、-0.777,均P>0.05)。200例大血小板样本,电阻抗法血小板(PLT-I)计数为100(84,127)×10^(9)/L,光学血小板(PLT-O)计数为104(85,132)×10^(9)/L,PLT-O高于PLT-I计数,差异无统计学意义(Z=-0.280,P>0.05)。217例WNB散点图Ghost区域异常的血小板聚集样本,PLT-I计数为95(77,119)×10^(9)/L,PLT-O计数为110(89,146)×10^(9)/L,PLT-O高于PLT-I计数,差异具有统计学意义(Z=-2.987,P<0.05)。结论血细胞分析检测及报告审核过程应结合血细胞计数、WDF散点图、WNB散点图、血小板直方图等信息,合理制定血小板复检规则及流程,必要时结合形态学分析结果综合判断,以保证血细胞分析检验结果准确可靠。 展开更多
关键词 散点图 血细胞分析仪 血小板 复检流程
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“天津桥上闻杜鹃”:一则政治寓言的建构、流传与化用
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作者 曹鹏程 李奕安 《中华文化论坛》 北大核心 2026年第2期67-73,共7页
“天津桥上闻杜鹃”是邵伯温在南宋初年的政治语境中建构的政治寓言。它借助邵雍的前知形象,将杜鹃出现在洛阳解释为政局转变与天下将乱的先兆,以抨击王安石与新党。在宋元士人反思宋代覆亡的过程中,这则寓言的叙事被广泛接受,成为极具... “天津桥上闻杜鹃”是邵伯温在南宋初年的政治语境中建构的政治寓言。它借助邵雍的前知形象,将杜鹃出现在洛阳解释为政局转变与天下将乱的先兆,以抨击王安石与新党。在宋元士人反思宋代覆亡的过程中,这则寓言的叙事被广泛接受,成为极具象征意义的文化符号。降至明初,这一符号被移植到元代覆亡的情境中,演变为可被反复调用的历史书写模式,折射出宋元明史家的政治立场与情感转变。“天津桥上闻杜鹃”叙事的建构、流传与模式化,体现了历史书写模式形成过程中时代背景、政治文化、知识传统等多方面的影响。 展开更多
关键词 杜鹃 邵伯温 模式化情节 历史书写
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面向耕地地块的水稻种植信息精细提取
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作者 刘善磊 李梦梦 +1 位作者 范雪婷 张亮 《测绘与空间地理信息》 2026年第1期53-56,共4页
针对江南水乡河网密布、耕地破碎的特点,结合多源影像数据在时间和空间分辨率的优势,探讨了面向耕地地块的水稻种植信息精细提取。首先以国土变更调查数据和优于1 m的卫星遥感影像数据为基础,构建多源、多时相、多尺寸耕地地块影像样本... 针对江南水乡河网密布、耕地破碎的特点,结合多源影像数据在时间和空间分辨率的优势,探讨了面向耕地地块的水稻种植信息精细提取。首先以国土变更调查数据和优于1 m的卫星遥感影像数据为基础,构建多源、多时相、多尺寸耕地地块影像样本库,接着通过深度学习框架获取耕地地块。在此基础上基于多时序Sentinel-2数据,利用时序数据重构和缺失信息插补等技术结合水稻物候期,从地块级别获得水稻种植信息,与董浜镇农业统计年鉴数据相比,精度达到94%,基于地理方格网的目标随机抽样精度达96%。研究表明,所采用的方法适用于小区域水稻的精细提取,能为小型灌区内水稻遥感监测和种植结构调整提供有效可行的参考和借鉴。 展开更多
关键词 耕地地块 混合像元 时序重构 种植结构
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谈电影叙事中的描写行为
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作者 赵世佳 梁晓辉 《衡水学院学报》 2026年第2期124-128,共5页
电影叙事文本所运用的媒介语言具有非常直观的运动性,这似乎与叙事中必须将故事时间停止下来才能进行的描写行为相矛盾。但这只是一种错觉,故事时间的停止并不意味着运动的终结。由于叙事的逻辑基础是序列性,读者阅读小说时想象的画面... 电影叙事文本所运用的媒介语言具有非常直观的运动性,这似乎与叙事中必须将故事时间停止下来才能进行的描写行为相矛盾。但这只是一种错觉,故事时间的停止并不意味着运动的终结。由于叙事的逻辑基础是序列性,读者阅读小说时想象的画面其实一直都是运动的。这种运动一方面源自情节序列,另一方面源自空间展现序列(亦即描写序列)。因此,描写行为与运动并不真正构成矛盾。若要辨识电影叙事中的描写行为,首先要识别出那些纯粹呈现状态的事件段落,并确定此类状态性事件段落不会改变故事内某一主体的知觉状态。当两个这样的状态性事件段落直接组合在一起时,电影叙事文本中的描写行为就产生了。 展开更多
关键词 电影叙事 描写行为 情节 序列性 状态性事件
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