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Comparative Experiment of Ground Cucumber Varieties for Open Field Cultivation
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作者 Meiguang BI Yuanyuan CHE Lizhi YU 《Agricultural Biotechnology》 CAS 2018年第3期30-31,共2页
Seven ground cucumber varieties were cultivated in open field for the comparative experiment. The results showed that Texuan cucumber and Yantai ground cucumber had good commodity characters,good taste and high yield,... Seven ground cucumber varieties were cultivated in open field for the comparative experiment. The results showed that Texuan cucumber and Yantai ground cucumber had good commodity characters,good taste and high yield,and their output value exceeded 16 000 yuan/666. 7 m2,so they are more suitable for open cultivation in Yantai region. The next ones are Meiyu Diguawang and Aweishi ground cucumber. 展开更多
关键词 open field cultivation Ground cucumber VARIETY Comparative experiment
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Comparison of Cold Tolerance in Three Ground-cover Chrysanthemum Cultivars during Wintering in the Open Field
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作者 Xin ZHOU Man SHEN Pingsheng LENG 《Agricultural Biotechnology》 CAS 2022年第2期30-37,共8页
[Objectives]Among many chrysanthemum types,the ground-cover chrysanthemum cultivar group has the characteristics of dwarf plant,long flowering period,rich color and strong resistance to stress.This study aimed to scre... [Objectives]Among many chrysanthemum types,the ground-cover chrysanthemum cultivar group has the characteristics of dwarf plant,long flowering period,rich color and strong resistance to stress.This study aimed to screen out cultivars with strong cold tolerance in order that they can be used for planting in urban green space and economic forests in northern cold areas,so as to enrich the plant community structures of landscape in cold regions.[Methods]Three ground-cover chrysanthemum cultivars,i.e.,‘Meiaihuang’,‘Xinhong’and‘Zixunzhang’,were selected as the experimental materials.During the wintering period in the field in Beijing,they were observed and measured for the changes of the morphological manifestations and the physiological indices,and the relationship between the indices and low temperature was analyzed.The cold tolerance of the three ground-cover chrysanthemum cultivars was also comprehensively evaluated.[Results]During the open-field overwintering period,the root activity of the three ground-cover chrysanthemum cultivars increased slowly with cooling,decreased at the freezing low temperature,and then increased again in early spring.With natural cooling,the membrane injury percentages(MIPs)of the leaves and foot shoots increased significantly,and the contents of malondialdehyde(MDA)increased;the contents of soluble sugar(SS)and proline(Pro)gradually accumulated,and the contents of SS and Pro in foot shoots increased significantly in late winter;and the superoxide dismutase(SOD)activity showed a similar trend of rising slowly at first and then increasing significantly.There were correlations between MIPs in the leaves and foot shoots of the three cultivars and other physiological indices:a significant negative correlation with MDA content,and a significant positive correlation with SS content,Pro content and SOD activity.[Conclusions]Combining the morphological manifestations and physiological indices,the cold tolerance of the three ground-cover chrysanthemum cultivars was evaluated by the subordinate function method.The results showed that the cold tolerance of the three ground-cover chrysanthemum cultivars ranked as‘Meiaihuang’>‘Xinhong’>‘Zixunzhang’.The strong cold tolerance of foot shoots and roots was the main reason that the three ground-cover chrysanthemum cultivars could overwinter in the open field. 展开更多
关键词 Ground-cover chrysanthemum Cold tolerance Overwinter in the open field Comprehensive evaluation
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Analysis of the Declining of Open Field System in the Medieval England from the Perspective of Institutional Transition
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作者 Zhang Lin 《International English Education Research》 2015年第9期46-48,共3页
关键词 变迁 角度分析 英国 土地使用权 农村改革 耕作制度 财产权 开放式
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宁心解郁胶囊对慢性应激抑郁模型大鼠Open-Field行为的影响 被引量:2
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作者 孙亚男 邹忆怀 朱陵群 《天津中医药》 CAS 2014年第1期42-46,共5页
[目的]探讨宁心解郁胶囊的抗抑郁作用及可能的机制。[方法]以孤养加慢性轻度不可预见性应激方法建立大鼠抑郁模型,用Open-Field方法进行行为学评定,观察模型大鼠给药前后的行为学变化。[结果]经过孤养加慢性轻度不可预见性应激方法造模... [目的]探讨宁心解郁胶囊的抗抑郁作用及可能的机制。[方法]以孤养加慢性轻度不可预见性应激方法建立大鼠抑郁模型,用Open-Field方法进行行为学评定,观察模型大鼠给药前后的行为学变化。[结果]经过孤养加慢性轻度不可预见性应激方法造模后的大鼠,Open-Field行为学评定中模型组大鼠的总路程、平均速度、中央活动路程、中央活动时间、各角的活动路程和时间均较空白组有统计学差异(P<0.05)。治疗后大鼠的总活动路程、平均速度、中央活动时间、中央活动路程、下边活动路程、下边活动时间、各角的活动路程和时间均较模型组有统计学差异(P<0.05),活动路程较模型组增加,活动时间较模型组增加,且以中剂量组效果显著。[结论]宁心解郁胶囊具有抗抑郁作用,对大鼠抑郁行为有明显改善。 展开更多
关键词 宁心解郁胶囊 慢性应激抑郁模型 openfield实验 行为学
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Life cycle assessment of open field and greenhouse cultivation of lettuce and barley 被引量:7
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作者 Georgios Bartzas Dimitra Zaharaki Kostas Komnitsas 《Information Processing in Agriculture》 EI 2015年第3期191-207,共17页
In the present paper,a life cycle assessment(LCA)study regarding barley and lettuce production in Spain(Barrax and Santomera regions)and Italy(Albenga region)in both open field(OF)and standard greenhouse(GH)cultivatio... In the present paper,a life cycle assessment(LCA)study regarding barley and lettuce production in Spain(Barrax and Santomera regions)and Italy(Albenga region)in both open field(OF)and standard greenhouse(GH)cultivations was performed in order to evaluate energy consumption and environmental impacts.The study examines also the impact of the use of compost produced from agricultural wastes(AW).In this context,a detailed life cycle directory was created,based on site-specific experimental data,and used for a holistic cradle-to-gate LCA analysis using the GaBi 6 software package and specific related databases.In order to reveal the importance of system boundaries,factors that are often excluded from LCA studies,such as agricultural machinery manufacture,nursery production,waste management and raw materials transportation have been considered.According to the results of this study,the use of compost for fertilization of both crops is considered a good agronomic and ecological strategy in order to maintain productivity in terms of yield,especially in the case of greenhouse cultivation,and improve overall sustainability in the agricultural sector.Moreover,the phases of compost production,irrigation system,and greenhouse construction and operation were identified as the three main‘‘hotspots”with the highest environmental impact and energy contribution in all studied cases.Finally,improvements to reduce those impacts were proposed. 展开更多
关键词 LCA Agricultural waste LETTUCE BARLEY open field GREENHOUSE
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Suitability of open-field autorefractors as pupillometers and instrument design effects
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作者 Carles Otero Mikel Aldaba +3 位作者 Oriol Ferrer Andrea Gascón Juan C Ondategui-Parra Jaume Pujol 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第4期567-572,共6页
AIM:To determine the agreement and repeatability of the pupil measurement obtained with VIP-200(Neuroptics),Power Ref II(Plusoptix),WAM-5500(Grand Seiko) and study the effects of instrument design on pupillomet... AIM:To determine the agreement and repeatability of the pupil measurement obtained with VIP-200(Neuroptics),Power Ref II(Plusoptix),WAM-5500(Grand Seiko) and study the effects of instrument design on pupillometry.METHODS:Forty patients were measured twice in low,mid and high mesopic.Repeatability was analyzed with the within-subject standard deviation(Sw) and paired t-tests.Agreement was studied with Bland-Altman plots and repeated measures ANOVA.Instrument design analysis consisted on measuring pupil size with Power Ref II simulating monocular and binocular conditions as well as with proximity cues and without proximity cues.RESULTS:The mean difference(±standard deviation) between test-retest for low,mid and high mesopic conditions were,respectively:-0.09(±0.16),-0.05(±0.18) and-0.08(±0.23) mm for Neuroptics,-0.05(±0.17),-0.12(±0.23) and-0.17(±0.34) mm for WAM-5500,-0.04(±0.27),-0.13(±0.37) and-0.11(±0.28) mm for Power Ref II.Regarding agreement with Neuroptics,the mean difference for low,mid and high mesopic conditions were,respectively:-0.48(±0.35),-0.83(±0.52) and-0.38(±0.56) mm for WAM-5500,-0.28(±0.56),-0.70(±0.55) and-0.61(±0.54) mm for Power Ref II.The mean difference of binocular minus monocular pupil measurements was:-0.83(±0.87) mm;and with proximity cues minus without proximity cues was:-0.30(±0.77) mm.CONCLUSION:All the instruments show similar repeatability.In all illumination conditions,agreement of Neuroptics with WAM-5500 and Power Ref II is not good enough,which can be partially induced due to their open field design. 展开更多
关键词 PUPIL REPEATABILITY AGREEMENT open-field
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Positions Open in the Field of Plasma and Fusion
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《Plasma Science and Technology》 SCIE EI CAS CSCD 2004年第5期i001-i001,共1页
Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is sear... Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma diagnostics, electron cyclotron resonant heating, ion cyclotron resonant heating, lower hybrid wave, neutral beam injection, reactor design, fusion material, superconducting engineering. 展开更多
关键词 Positions open in the field of Plasma and Fusion open
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Positions Open in the Field of Plasma and Fusion
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《Plasma Science and Technology》 SCIE EI CAS CSCD 2004年第6期i004-i004,共1页
Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is sear... Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma diagnostics, electron cyclotron resonant heating, ion cyclotron resonant heating, lower hybrid wave, neutral beam injection, reactor design, fusion material, superconducting engineering. 展开更多
关键词 open Positions open in the field of Plasma and Fusion
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Positions Open in the Field of Plasma and Fusion
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《Plasma Science and Technology》 SCIE EI CAS CSCD 2004年第3期i001-i001,共1页
Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important Laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is sear... Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important Laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma diagnostics, electron cyclotron resonant heating, ion cyclotron resonant heating, lower hybrid wave, neutral beam injection, reactor design, fusion material, superconducting engineering. 展开更多
关键词 open Positions open in the field of Plasma and Fusion
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Experimental Measurement of Minority Carriers Effective Lifetime in Silicon Solar Cell Using Open Circuit Voltage Decay under Magnetic Field in Transient Mode
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作者 Alain Diasso Raguilignaba Sam +1 位作者 Bernard Zouma François Zougmoré 《Smart Grid and Renewable Energy》 2020年第11期181-190,共10页
<span style="font-family:Verdana;">This manuscript presents a simple method for excess minority carriers’ lifetime measurement</span><span style="font-family:""> </span&g... <span style="font-family:Verdana;">This manuscript presents a simple method for excess minority carriers’ lifetime measurement</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">within the base region of p-n junction polycrystalline solar </span><span style="font-family:Verdana;">cell</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">in transient mode.</span><span style="font-family:""> </span><span style="font-family:Verdana;">This work is an experimental transient</span><span style="font-family:Verdana;"> 3-Dimensionnal study.</span><span style="font-family:""> </span><span style="font-family:Verdana;">The magnitude of the magnetic field B is varied from 0 mT to 0.045 mT. Indeed, the solar cell is illuminated by a stroboscopic flash with air mass 1.5</span><span style="font-family:""> </span><span style="font-family:Verdana;">and under magnetic field in transient state.</span><span style="font-family:""> </span><span style="font-family:Verdana;">The experimental details are assumed in a figure. The procedure is outlined by the Open Circuit Voltage Decay analysis. Effective minority carrier life-time is calculated by fitting the linear zone of the transient voltage decay curve</span><span style="font-family:""> </span><span style="font-family:Verdana;">because linear decay is an ideal decay. The kaleidagraph software permits access to the slope of the curve which is inversely proportional to the</span><span style="font-family:""> </span><span style="font-family:Verdana;">lifetime. The external magnetic effects</span><span style="font-family:""> </span><span style="font-family:Verdana;">on minority carriers’ effective lifetime </span><span style="font-family:Verdana;">is</span><span style="font-family:Verdana;"> then</span><span style="font-family:""> </span><span style="font-family:Verdana;">presented and analyzed.</span><span style="font-family:""> </span><span style="font-family:Verdana;">The analysis show</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> that the charge carrier</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">s effective lifetime decrease with the magnetic field increase.</span> 展开更多
关键词 Carrier Lifetime FITTING Magnetic field open Circuit Voltage Decay
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Bruch's membrane opening-minimum rim width and visual field loss in glaucoma:a broken stick analysis 被引量:1
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作者 Keun-Heung Park Ji-Woong Lee +2 位作者 Jin-Mi Kim Kouros Nouri-Mahdavi Joseph Caprioli 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第5期828-834,共7页
AIM:To determine the Bruch's membrane opening-minimum rim width(BMO-MRW) tipping point where corresponding visual field(VF) damages become detectable.METHODS:A total of 85 normal subjects and 83 glaucoma patie... AIM:To determine the Bruch's membrane opening-minimum rim width(BMO-MRW) tipping point where corresponding visual field(VF) damages become detectable.METHODS:A total of 85 normal subjects and 83 glaucoma patients(one eye per participant) were recruited for the study.All of the patients had VF examinations and spectral-domain optical coherence tomography to measure the BMO-MRW.Total deviation values for 52 VF points were allocated to the corresponding sector according to the Garway-Heath distribution map.To evaluate the relationship between VF loss and BMOMRW measurements,a "broken-stick" statistical model was used.The tipping point where the VF values started to sharply decrease as a function of BMO-MRW measurements was estimated and the slopes above and below this tipping point were compared.RESULTS:A 25.9% global BMO-MRW loss from normative value was required for the VF loss to be detectable.Sectorally,substantial BMO-MRW thinning in inferotemporal sector(33.1%) and relatively less BMO-MRW thinning in the superotemporal sector(8.9%) were necessary for the detection of the VF loss.Beyond the tipping point,the slopes were close to zero throughout all of the sectors and the VF loss was unrelated to the BMO-MRW loss.The VF loss was related to the BMO-MRW loss below the tipping point.The difference between the two slopes was statistically significant(P≤0.002).CONCLUSION:Substantial BMO-MRW loss appears to be necessary for VF loss to be detectable in patients with open angle glaucoma with standard achromatic perimetry. 展开更多
关键词 Bruch's membrane opening-minimum rim width visual field loss structure function relationship broken stick model optical coherence tomography
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半夏泻心汤对功能性消化不良大鼠抑郁状态及促肾上腺皮质激素释放因子相关通路的影响
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作者 耿琦 李敬伟 +1 位作者 凌江红 蒋健 《陕西中医》 CAS 2024年第2期147-152,共6页
目的:观察半夏泻心汤对功能性消化不良(FD)大鼠抑郁样行为、下丘脑促肾上腺皮质激素释放因子(CRF)及其受体CRF-R1、CRF-R2的影响。方法:48只SPF级Wistar大鼠随机分为空白组、模型组、氟西汀组、半夏泻心汤低、中、高剂量组,共六组,每组... 目的:观察半夏泻心汤对功能性消化不良(FD)大鼠抑郁样行为、下丘脑促肾上腺皮质激素释放因子(CRF)及其受体CRF-R1、CRF-R2的影响。方法:48只SPF级Wistar大鼠随机分为空白组、模型组、氟西汀组、半夏泻心汤低、中、高剂量组,共六组,每组各8只。空白组正常饲养,其余五组采用不规则喂养+夹尾激惹刺激法造模,造模成功后半夏泻心汤低、中、高各剂量组分别给予0.62、1.24、2.48 g/ml剂量灌胃,氟西汀组给予2 mg/kg氟西汀,空白组及模型组均给予同等容积的蒸馏水,各组连续灌胃14 d。干预结束后采用糖水偏好实验和旷场实验测试各组抑郁样行为;HE染色观察大鼠胃窦组织基本形态;RT-qPCR和Western blot检测大鼠下丘脑中CRF、CRF-R1和CRF-R2 mRNA和蛋白的表达。结果:与空白组比较,模型组大鼠体重、糖水偏好度、旷场实验移动总距离和直立次数均明显下降(P<0.05);下丘脑中CRF、CRF-R1 mRNA和蛋白表达均明显升高(P<0.01),CRF-R2 mRNA和蛋白的表达均明显降低(P<0.01)。与模型组比较,半夏泻心汤各剂量组大鼠的体重、糖水偏好度、旷场实验移动总距离和直立次数均明显增加(P<0.05);半夏泻心汤各剂量组FD大鼠下丘脑中CRF、CRF-R1 mRNA的表达量均明显降低(P<0.01),CRF-R2 mRNA的表达明显升高;半夏泻心汤高剂量组FD大鼠下丘脑中CRF蛋白表达均明显降低(P<0.01),半夏泻心汤各剂量组FD大鼠下丘脑中CRF-R1蛋白表达明显降低(P<0.01),CRF-R2蛋白表达升高(P<0.05)。结论:半夏泻心汤可通过调控CRF通路,恢复CRF-R1和CRF-R2的平衡状态,发挥抗抑郁的作用。 展开更多
关键词 功能性消化不良 半夏泻心汤 抑郁状态 糖水偏好实验 旷场实验 促肾上腺皮质激素释放因子通路
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露地辣椒生产固碳增活全程施肥方案
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作者 李若楠 王丽英 +5 位作者 史建硕 陈莉 李建芬 贾舟 蒋龙刚 李桃 《中国果菜》 2024年第7期74-80,共7页
河北露地辣椒种植历史悠久,但生产中粗放的养分管理,导致土壤有机质消耗,植株抗逆性差,连作障碍频发。本文基于露地辣椒生产固碳增活施肥技术,围绕肥料养分均衡减量、有机替代固碳增效、菌剂滴灌沃土增活3项核心内容,从肥料养分总量推... 河北露地辣椒种植历史悠久,但生产中粗放的养分管理,导致土壤有机质消耗,植株抗逆性差,连作障碍频发。本文基于露地辣椒生产固碳增活施肥技术,围绕肥料养分均衡减量、有机替代固碳增效、菌剂滴灌沃土增活3项核心内容,从肥料养分总量推荐、有机物料多源配施、滴灌肥水协同运筹等方面制定了河北露地辣椒生产固碳增活全程施肥解决方案,并对比四种固碳技术模式应用效果,发现基施多样化来源的有机物料朝天椒增产效果优于单一有机物料,优选牛粪堆肥+秸秆类生物炭模式或牛粪堆肥+玉米秸秆+秸秆类生物炭技术模式(秸秆还田条件),以助力传统辣椒产区耕地保护与土壤质量提升,促进种植户养分管理由盲目粗放向合理精准转变。 展开更多
关键词 露地辣椒 固碳增活 有机肥料 菌剂 滴灌
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Effect of Mushroom Extract Hericium erinaceus on Spatial Memory and Morphology of Neurons in the CA1 and CA3 Regions of the Hippocampus in Ovariectomized Rats
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作者 Lucia Garcia-Delgado Mariana Monserrath Verdía-Venegas +5 位作者 Jacinto Bañuelos-Pineda Esther Albarrán-Rodríguez Guillermo Nolasco-Rodriguez José Ricardo Cuellar-Pérez Sergio Fausto-Guerra Manuel Rosales-Cortés 《Open Journal of Veterinary Medicine》 CAS 2024年第7期163-179,共17页
Various studies indicate that low levels of estradiol negatively impact cognitive abilities. Extracts from the fungus Hericium erinaceus (HE) contain bioactive components that promote the proper functioning of the ner... Various studies indicate that low levels of estradiol negatively impact cognitive abilities. Extracts from the fungus Hericium erinaceus (HE) contain bioactive components that promote the proper functioning of the nervous system and potential effects on protection against neurodegenerative diseases, including dementia and motor dysfunctions. The objective was to evaluate the effects of the administration of the HE mushroom extract on visuospatial memory and morphology of neurons in the CA1 and CA3 regions of the hippocampus in ovariectomized rats. 40 young Wistar rats weighing 90 ± 10 g BW were used, which were distributed into four groups of 10 animals;Control Group, non-ovariectomized and untreated rats;Group E2, ovariectomized rats treated with estradiol (2 μg/kg/body weight);Group HE, ovariectomized rats treated with the extract of the fungus Hericium erinaceus (0.5 mg/kg body weight) and Group Ovx/ST, ovariectomized rats, without treatment. The animals were tested in the Barnes and Open Field maze, then they were sacrificed, and their brains were obtained to perform a histological analysis of neuronal morphology in the CA1 and CA3 areas of the hippocampus. The most outstanding results showed that the Ovx/ST group recorded the longest time to arrive at the escape box and stay in the Barnes maze. A correlation was observed between neuronal damage and function;in the groups that did not present satisfactory performance in the maze tests, morphological alterations were identified such as the presence of some neuronal somata with degeneration characteristics such as pyknosis, nuclear basophilia and shrinkage of the cells. Its soma, as well as a decrease in the nuclear area of CA1 and CA3 neurons. It is concluded that the fungus Hericium erinaceus exerted a neuroprotective effect on the neuronal bodies of the hippocampus, associated with better performance in the visuospatial recognition memory test. 展开更多
关键词 Ovariectomized Rats Ovarian Hypofunction ESTRADIOL Hericium erinaceus Barnes Circular Labyrinth open field Labyrinth
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宁夏中部干旱区露地甘薯栽培适应性比较研究
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作者 张丽娟 曲继松 +3 位作者 朱倩楠 黄灵丹 杜海东 王瑞 《宁夏农林科技》 2024年第4期5-12,共8页
为丰富宁夏干旱区适宜栽种的甘薯品种,实现区域甘薯产业高质高效持续发展,以收集的国内外23个甘薯品种为材料,对植株农艺性状、甘薯产量、甘薯品质、栽培适应性等多指标进行比较分析。结果表明,徐薯25、苏薯8号、安平一号、济薯26号、徐... 为丰富宁夏干旱区适宜栽种的甘薯品种,实现区域甘薯产业高质高效持续发展,以收集的国内外23个甘薯品种为材料,对植株农艺性状、甘薯产量、甘薯品质、栽培适应性等多指标进行比较分析。结果表明,徐薯25、苏薯8号、安平一号、济薯26号、徐薯55-1、安纳芋、徐薯27、岩薯5号8个品种为早熟品种,9月中旬为最佳采收期。徐薯28和烟薯25号2个品种9月中旬至10月初采收均可;其他品种为中晚熟品种,适宜10月初采收。烟薯25号、川薯产量高(单株产量分别为2518 g、2295 g),综合品质较好。济薯26号和徐薯55-2产量及可溶性糖含量(分别为3.32%和3.25%)、富硒方面均有优势,适宜开发本地区鲜食品种;徐紫8号、徐紫5号2个紫薯品种产量均不高;徐紫8号粗纤维含量低,硒含量较高;徐紫5号淀粉含量较高。烟薯25号、川薯、济薯26号和徐薯55-2可作为宁夏干旱区域甘薯推荐种植品种。 展开更多
关键词 甘薯 露地栽培 农艺性状 适应性 宁夏中部干旱区
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河北省露地菜田固碳增活对策及解决方案
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作者 李若楠 王丽英 +3 位作者 史建硕 陈莉 贾舟 孙璇 《河北农业科学》 2024年第3期45-49,88,共6页
河北省是蔬菜生产大省,但露地蔬菜生产中养分管理较为粗放,长期存在有机物料施用种类单一、偏施化学氮肥、肥料养分配比失衡等问题,导致土壤有机质水平低、有效养分供应能力弱、连作障碍频发。针对露地蔬菜生产中存在的施肥问题,建立了... 河北省是蔬菜生产大省,但露地蔬菜生产中养分管理较为粗放,长期存在有机物料施用种类单一、偏施化学氮肥、肥料养分配比失衡等问题,导致土壤有机质水平低、有效养分供应能力弱、连作障碍频发。针对露地蔬菜生产中存在的施肥问题,建立了固碳增效与沃土增活综合施肥技术,制定了全程施肥解决方案。有助于改善与提升菜田土壤质量,促进蔬菜稳产增产和菜农增收,具有广阔的应用前景。 展开更多
关键词 露地蔬菜 土壤固碳增活 施肥技术 全程施肥解决方案
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苏里格致密砂岩气田效益开发技术对策研究
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作者 程敏华 雷丹凤 +2 位作者 张连群 刘丽芳 赵蒙 《油气藏评价与开发》 CSCD 北大核心 2024年第3期475-483,共9页
苏里格气田致密砂岩气藏的天然气储量规模和年产气量目前都位居中国第一。随着开发不断深入,气田储量品质劣质化及未动用储量碎片化趋势明显,增加了未来效益开发的不确定性。为确保气田致密砂岩气藏的可持续效益开发,基于深化气田开发... 苏里格气田致密砂岩气藏的天然气储量规模和年产气量目前都位居中国第一。随着开发不断深入,气田储量品质劣质化及未动用储量碎片化趋势明显,增加了未来效益开发的不确定性。为确保气田致密砂岩气藏的可持续效益开发,基于深化气田开发过程中所获得的地质与气藏工程认识的基础上,梳理了影响气田效益开发的影响因素,建立了该气田效益开发的技术对策。研究结果表明:①基于以经济产量为中心的评价模型对气田各区块经济效益进行实证分析,可以评价气田目前整体效益开发现状,指导未来整体开发方向;②为了支持气田致密气产业进一步发展,根据气田各区块效益评价,从地质和气藏工程的角度去寻求有效开发的配套措施,分类治理,分类施策,进而形成苏里格气田效益开发技术对策,实现气田持续经济有效开发。 展开更多
关键词 苏里格气田 致密气 无阻流量 内部收益率 效益开发
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基于无人机多光谱植被指数的生菜全氮含量预测
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作者 连炳瑞 李雅豪 +6 位作者 张静 李长青 杨小冬 王激清 邹国元 Thompson Rodney 杨俊刚 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第8期2318-2325,共8页
我国露地蔬菜种植规模庞大,生产方式高度集约化,但过量施肥等导致的水氮利用效率低下的问题较为严重。为实现露地蔬菜规模化种植中精准施肥、高效生产的目标,以露地生菜为研究对象,设无氮(N0)、低氮(N1)、高氮(N2)三个处理,通过无人机... 我国露地蔬菜种植规模庞大,生产方式高度集约化,但过量施肥等导致的水氮利用效率低下的问题较为严重。为实现露地蔬菜规模化种植中精准施肥、高效生产的目标,以露地生菜为研究对象,设无氮(N0)、低氮(N1)、高氮(N2)三个处理,通过无人机搭载多光谱相机,建立3种多光谱植被指数(NDVI、RVI和SAVI)与生菜叶绿素、生物量、吸氮量、全氮含量数据集,并构建单生育期和多生育期氮素诊断模型。结果表明:(1)在莲座期和结球期,生菜各处理NDVI、RVI和SAVI值表现出随施氮量的增加而增大,但在收获期,N1处理达到最大值。(2)在生菜结球期,NDVI与生菜的产量、吸氮量、叶绿素均存在显著相关性,其中生菜全氮含量与叶绿素在p≤0.01水平下显著相关,相关系数(R)为0.51;综合生菜多生育期,NDVI值与生菜的产量、叶绿素、吸氮量和全氮含量均在p≤0.001水平下达到极显著相关,相关系数分别为0.85、0.82、0.81和0.71。(3)通过相应数据集拟合出指数、线性、对数和幂函数4种模型关系,建立生菜多生育期植株全氮最佳预测模型:全氮=16.52ln(NDVI)+73.514;应用生菜全氮估层模型反演基地生产田块,其平均相对误差为3.22%、RMSE=0.5566、NRMSE=0.0108,说明模型估算效果均较好,通过无人机多光谱遥感对蔬菜氮素诊断具有一定的可行性。 展开更多
关键词 露地生菜 无人机多光谱 NDVI 全氮 预测模型
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基于扰动观测器的五相永磁同步电机开路和短路容错矢量控制
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作者 周华伟 陈铖 +2 位作者 向小龙 张多 陈前 《电工技术学报》 EI CSCD 北大核心 2024年第15期4782-4793,共12页
针对反电动势含有3次谐波的五相永磁同步电机(PMSM)开路和短路故障导致转矩脉动大的问题,该文提出一种基于扰动观测器的矢量控制(DOB-FOC)策略。该策略基于降阶正交变换矩阵在同步旋转坐标系上建立PMSM开路故障情况下的基波模型,将3次... 针对反电动势含有3次谐波的五相永磁同步电机(PMSM)开路和短路故障导致转矩脉动大的问题,该文提出一种基于扰动观测器的矢量控制(DOB-FOC)策略。该策略基于降阶正交变换矩阵在同步旋转坐标系上建立PMSM开路故障情况下的基波模型,将3次谐波反电动势、短路电流等作为扰动信号。在此基础上,设计扰动观测器,观测出以上扰动导致的转矩脉动,将其转化为q轴补偿电流前馈到q轴电流指令中,有效地抑制了故障导致的转矩脉动,并且实现了PMSM在开路和短路故障情况下的平稳无扰运行。仿真和实验结果验证了所提容错策略的有效性。 展开更多
关键词 永磁同步电机(PMSM) 矢量控制(FOC) 开路故障 短路故障 扰动观测器
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数据要素在医疗健康领域的内涵、价值与应用
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作者 朱庆华 王晰 赵宇翔 《图书情报知识》 北大核心 2024年第2期13-17,共5页
十七部门联合发布的《“数据要素×”三年行动计划(2024—2026年)》引发了社会的广泛关注。本文首先探讨医疗健康领域数据要素的本质、分类及其重要性。在此基础上,提出促进医疗健康数据融合创新的关键策略,包括通过技术赋能医疗健... 十七部门联合发布的《“数据要素×”三年行动计划(2024—2026年)》引发了社会的广泛关注。本文首先探讨医疗健康领域数据要素的本质、分类及其重要性。在此基础上,提出促进医疗健康数据融合创新的关键策略,包括通过技术赋能医疗健康数据的采集,推动医疗健康数据的整合与标准化工作,促进医疗健康数据的开放和共享,以及加强对医疗健康数据的安全保护。 展开更多
关键词 医疗健康领域 数据要素 数据标准化 数据开放共享 数据安全
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