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Fuzzy Varying Coefficient Bilinear Regression of Yield Series
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作者 Ting He Qiujun Lu 《Journal of Data Analysis and Information Processing》 2015年第3期43-54,共12页
We construct a fuzzy varying coefficient bilinear regression model to deal with the interval financial data and then adopt the least-squares method based on symmetric fuzzy number space. Firstly, we propose a varying ... We construct a fuzzy varying coefficient bilinear regression model to deal with the interval financial data and then adopt the least-squares method based on symmetric fuzzy number space. Firstly, we propose a varying coefficient model on the basis of the fuzzy bilinear regression model. Secondly, we develop the least-squares method according to the complete distance between fuzzy numbers to estimate the coefficients and test the adaptability of the proposed model by means of generalized likelihood ratio test with SSE composite index. Finally, mean square errors and mean absolutely errors are employed to evaluate and compare the fitting of fuzzy auto regression, fuzzy bilinear regression and fuzzy varying coefficient bilinear regression models, and also the forecasting of three models. Empirical analysis turns out that the proposed model has good fitting and forecasting accuracy with regard to other regression models for the capital market. 展开更多
关键词 FUZZY VARYING coefficient BILINEAR Regression Model FUZZY Financial Assets yield LEAST-SQUARES Method Generalized Likelihood Ratio Test Forecast
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Dynamics and Hopf Bifurcation Analysis of a Chemostat Model with Modified Growth Rate and Variable Yield Coefficient
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作者 Md. Shariful Islam Touhid Hossain Mir Shariful Islam 《Open Journal of Modelling and Simulation》 2022年第4期417-427,共11页
The objective of this study is to analyze a chemostat model of very simple type with the Haldane expression of growth rate and a variable yield coefficient. The proposed modified model is analyzed qualitatively and qu... The objective of this study is to analyze a chemostat model of very simple type with the Haldane expression of growth rate and a variable yield coefficient. The proposed modified model is analyzed qualitatively and quantitatively. Analytic conditions for stability and optimality are determined for washout and no washout equilibrium solutions. One of the main focuses of the study is to determine parameter values for which Hopf Bifurcations occur in a bioreactor. It has been shown that the maximum stable non-washout equilibrium exits at a residence time under suitable parameter values. Hopf bifurcation is observed at three different conditions of the parameters. 展开更多
关键词 CHEMOSTAT Residence Time Hopf Bifurcation BIOREACTOR Growth Rate Haldane Model yield coefficient
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Correlation and Path Coefficient Analyses of Yield in Cacao(Theobroma cacao L.)
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作者 Omotayo Olalekan Adenuga Abigail Funlayo Adepoju +3 位作者 Ibrahim Olalekan Sobowale Olayinka Olufemi Olaniyi Oluwatobi James Areola Terkula Felix Nyamkyume 《Journal of Botanical Research》 2022年第3期1-8,共8页
Cacao(Theobroma cacao L.)is an important commodity tree crop which produces the cocoa bean,a major source of income for most West African countries and many smallholder farmers.Declining yield of cacao is a major limi... Cacao(Theobroma cacao L.)is an important commodity tree crop which produces the cocoa bean,a major source of income for most West African countries and many smallholder farmers.Declining yield of cacao is a major limitation to cocoa production in Nigeria.This study aimed at determining the correlations of the phenotypic traits that were related in the yield of the cacao genotypes.Nine cacao hybrids produced from some high-yielding parents in the research farm of Cocoa Research Institute of Nigeria,Ibadan,Nigeria were evaluated from 2012 through 2017 in Owena(7°11’N,5°1’E),Ondo state,Nigeria.Character Correlations and Path Coefficient Analysis were used in the description of the performance of the genotypes.The study concluded that significant genotypic and phenotypic correlations existed among many of the pairs of the fruit and bean characters with one another and with pod index,suggesting a complex contribution of these characters either positively or negatively to growth and yield in cacao,and that fruit and bean traits are determinants of yield in cacao. 展开更多
关键词 CACAO yield CORRELATION Phenotypic traits Path coefficients
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Determination of rock resistant coefficient based on Mohr-Coulomb criterion for underwater tunnel 被引量:5
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作者 Zhong-ren TU Qiang YANG +1 位作者 Qi-ming SHEN Xiao-wen WANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第9期1239-1244,共6页
According to the load-structure method, the wall rock with lining can bear the load caused by the surrounding rock, and the rock resistant coefficient (RRC) is a key parameter for evaluating the capacity of this wall ... According to the load-structure method, the wall rock with lining can bear the load caused by the surrounding rock, and the rock resistant coefficient (RRC) is a key parameter for evaluating the capacity of this wall rock. Based on the Mohr-Coulomb yield criterion, this paper develops a formula for calculating the RRC, which has been applied to the real engi-neering project, such as Xiamen Xiang’an East Passage Underwater Tunnel Project. The fact shows that this formula is helpful for designers to determine the RRC value. 展开更多
关键词 Rock resistant coefficient (RRC) Mohr-Coulomb yield criterion Rock mechanics Underwater tunnel
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Calculation of Empirical and True Maintenance Coefficients by Flux Balance Analysis 被引量:2
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作者 马红武 赵学明 郭晓峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第1期89-92,共4页
The stoichiometric matrix of a simplified metabolic network inBacillus Subtillis was constructed from the flux balance equations,which were used for reconciliation of the measured rates anddetermination of the inner m... The stoichiometric matrix of a simplified metabolic network inBacillus Subtillis was constructed from the flux balance equations,which were used for reconciliation of the measured rates anddetermination of the inner metabolic rates. Thus more reliableresults of the true and empirical maintenance coefficients wereobtained. The true maintenance coefficient is linearly related to thespecific growth rate and changes with the P/O ratio. The measuredbiomass yield of adenosine triphosphate (ATP) is also linearlyrelated to the P/O ratio. 展开更多
关键词 maintenance coefficient flux balance analysis metabolic network biomass yield
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Effect of particle gradation characteristics on yield stress of cemented paste backfill 被引量:22
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作者 Hai-yong Cheng Shun-chuan Wu +1 位作者 Xiao-qiang Zhang Ai-xiang Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第1期10-17,共8页
Along with slurry concentration and particle density,particle size distribution(PSD)of tailings also exerts a significant influence on the yield stress of cemented paste,a non-Newtonian fluid.In this work,a paste stab... Along with slurry concentration and particle density,particle size distribution(PSD)of tailings also exerts a significant influence on the yield stress of cemented paste,a non-Newtonian fluid.In this work,a paste stability coefficient(PSC)was proposed to characterize paste gradation and better reveal its connection to yield stress.This coefficient was proved beneficial to the construction of a unified rheological model,applicable to different materials in different mines,so as to promote the application of rheology in the pipeline transportation of paste.From the results,yield stress showed an exponential growth with increasing PSC,which reflected the proportion of solid particle concentration to the packing density of granular media in a unit volume of slurry,and could represent the properties of both slurry and granular media.It was found that slurry of low PSC contained extensive pores,generally around 20μm,encouraging free flow of water,constituting a relatively low yield stress.In contrast,slurry of high PSC had a compact and quite stable honeycomb structure,with pore sizes generally<5μm,causing the paste to overcome a higher yield stress to flow. 展开更多
关键词 paste backfill grading theory yield stress paste stability coefficient MICROSCALE
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Analysis of Yielding Ability and Yield Stability and Extension Prospect on New Maize Varieties in Jiangsu Province 被引量:1
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作者 郑飞 孔令杰 +5 位作者 刘瑞响 张美景 孟庆长 赵文明 陈艳萍 袁建华 《Agricultural Science & Technology》 CAS 2017年第4期619-623,626,共6页
[Objective] This study was conducted to select new hybrids with good ex- tension prospect, and to comprehensive assess various varieties and combinations from yielding ability, yield stability and adaptability. [Metho... [Objective] This study was conducted to select new hybrids with good ex- tension prospect, and to comprehensive assess various varieties and combinations from yielding ability, yield stability and adaptability. [Method] The yielding ability and yield stability of 5 varieties and 2 pioneer combinations in 5 test locations in Jiang- su Province in 2013-2015 were analyzed comprehensively. [Result] The environment effects and genotype x environment interaction effects of various tested varieties differed very significantly. It could be seen from various test locations that Mingyu 1301 and Sushi 51417 had very good yielding ability and yield stability, and were comprehensively assessed to be very good, Suyu 41 had very good yield stability and better yielding ability, and was comprehensively assessed to be good, while Suyu 29 and Suyu 39 showed instable yields in various locations and were greatly affected by environment, and thus should be planted in carefully-selected areas in extension. [Conclusion] This study provides theoretical foundation for breeding and extension of new varieties. 展开更多
关键词 MAIZE yielding ability yield stability High stability coefficient AMMI model
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Simulation of Runoff and Sediment Yield for a Kaneri Watershed Using SWAT Model 被引量:1
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作者 Vidula A. Swami Sushama S. Kulkarni 《Journal of Geoscience and Environment Protection》 2016年第1期1-15,共15页
Watershed as an entry point acts as a beginning to address the issues of sustainable rainwater management for improving livelihoods. Extraction of watershed parameters using Geographical Information System (GIS) and u... Watershed as an entry point acts as a beginning to address the issues of sustainable rainwater management for improving livelihoods. Extraction of watershed parameters using Geographical Information System (GIS) and use of simulation models is the current trend for hydrologic evaluation of watersheds. In the present study, the open Source Tool Quantum GIS 2.2.0 was used for preparation of maps to verify the spatial extent of the area. The Soil and Water Assessment Tool (SWAT) having an interface with Arc-View GIS software (ArcGIS 10.1 with Arc SWAT 2012 extension) was selected for the estimation of runoff and sediment yield from Kaneri watershed, located in Western Maharashtra region. The coefficient of determination (R<sup>2</sup>) for the monthly and yearly runoff was obtained as 0.849 and 0.951 respectively for the calibration period 1979 to 2000 and 0.801 and 0.950 respectively for the validation period 2001-2013. The R<sup>2</sup> value in estimating the monthly and yearly sediment yield during calibration period was computed as 0.722 and 0.788 respectively. The R<sup>2</sup> for monthly and yearly sediment yield values for validation period was observed to be 0.565 and 0.684 respectively. 展开更多
关键词 Arc SWAT CALIBRATION VALIDATION GIS RUNOFF Sediment yield coefficient of Determination R2
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Quantitative Assessment of the Impact of China's Direct Grain Subsidies on Grain Yield--Based on the Empirical Analysis of Panel Data Pertaining to 29 Provinces in the Period 2004-2007
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作者 SUN Shun-qiang ZHU Gui-ying 《Asian Agricultural Research》 2012年第4期34-36,共3页
We build the influence function empirical model of China's grain production at the present stage in view of the factors influencing direct grain subsidies,using Cobb-Douglas production function model.And we estima... We build the influence function empirical model of China's grain production at the present stage in view of the factors influencing direct grain subsidies,using Cobb-Douglas production function model.And we estimate the elasticity coefficient of impact of China's direct grain subsidies on grain yield,using the panel data pertaining to 29 provinces in the period 2004-2007;comparatively analyze the validity and limitation of policy factors of direct grain subsidies on China's grain yield.The results show that at the present stage,the elasticity coefficient of impact of China's direct grain subsidies on grain yield is 0.002 3,and under the existing subsidy system and level,direct grain subsidies play a positive role in increasing grain yield,but the role is limited;the elasticity coefficient of impact of the food price on grain yield is much larger than that of impact of direct grain subsidies on grain yield.Therefore,the government should strengthen and improve direct grain subsidy policies;in the mean time,pay full attention to the use of market mechanism to consolidate the basic role of the food price in promoting food security to a great extent. 展开更多
关键词 Direct grain subsidies Grain yield Food price Elasticity coefficient
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我国城镇污水处理厂污泥产率系数现状及影响因素分析 被引量:2
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作者 陈敏敏 刘杰 +3 位作者 李莉娜 邱立莉 杨伟伟 敬红 《工业水处理》 CAS CSCD 北大核心 2024年第3期24-29,共6页
以我国城镇污水处理厂生态环境统计和监测数据为基础,分析了我国城镇污水处理厂经验污泥产率系数(YQ)和以去除COD导致的污泥增殖来计算的污泥产率系数(YCOD),研究了进水COD、设计处理规模、处理工艺、区域分布等单一因素以及多因素与污... 以我国城镇污水处理厂生态环境统计和监测数据为基础,分析了我国城镇污水处理厂经验污泥产率系数(YQ)和以去除COD导致的污泥增殖来计算的污泥产率系数(YCOD),研究了进水COD、设计处理规模、处理工艺、区域分布等单一因素以及多因素与污泥产率系数的响应关系。结果表明,我国城镇污水处理厂YQ平均值为1.33×10-4 t/m3,YCOD平均值为0.81 kg/kg,YQ、YCOD总体呈正偏态分布;YQ平均值与进水COD、设计处理规模正相关,YCOD平均值与进水COD、设计处理规模负相关;YQ、YCOD平均值对应的COD区间范围为150~250 mg/L,设计处理规模为1×104~1×105 m3/d的污水处理厂YQ、YCOD与平均值最为接近,相对偏差分别为2.8%、-4.3%;A2/O工艺、氧化沟类、普通活性污泥法、A/O工艺的YQ、YCOD与平均值接近,相对偏差范围分别为-1.8%~1.9%、-2.3%~5.8%;华东和华中地区的YQ,华东、西南地区YCOD与平均值基本持平;多因素方差分析显示进水COD为YQ和YCOD的显著影响因素。 展开更多
关键词 城镇污水处理厂 污泥产率系数 影响因素 多因素方差分析
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新疆空中水资源和地表水资源变化特征研究 被引量:2
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作者 姚俊强 《干旱区研究》 CSCD 北大核心 2024年第2期181-190,共10页
大气降水是新疆一切水资源的根本来源,空中水资源是大气降水的物质基础,大气降水在当地形成地表水资源。水资源短缺是制约新疆经济社会高质量发展和生态安全保障的最关键自然因素。本文分析新疆空中水资源和地表水资源的变化特征,对新... 大气降水是新疆一切水资源的根本来源,空中水资源是大气降水的物质基础,大气降水在当地形成地表水资源。水资源短缺是制约新疆经济社会高质量发展和生态安全保障的最关键自然因素。本文分析新疆空中水资源和地表水资源的变化特征,对新疆水资源系统规划和高效利用具有重要的科学意义。结果显示:1961—2022年新疆年降水资源量为2717.12×10^(8)m^(3),水汽输入量为21115×10^(8)m^(3),水汽净收支量为347.5×10^(8)m^(3),水汽降水效率为12.5%;2001—2021年新疆平均水资源总量为912.3×10^(8)m^(3),其中地表水资源量为864.1×10^(8)m^(3),产水系数为0.32。从变化趋势来看,1961—2022年新疆年降水量明显增加,新疆上空水汽总输入量和总输出量微弱减少,水汽净收支量微弱增加,水汽降水效率明显增加;2001—2021年新疆地表水资源处于丰水阶段,但产水系数有微弱的波动减小趋势。新疆水资源问题依然突出,在不同水资源精细化特征、不同相态水体转化关系等方面研究不足,未来需要加强研究以应对气候变化可能带来的新疆水资源安全风险。 展开更多
关键词 空中水资源 地表水资源 产水系数 变化特征 新疆
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不同栽培深度对食用百合大花卷丹种球生长及产量的影响
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作者 王伟东 张睿琪 +4 位作者 白一光 胡新颖 李雪艳 周俐宏 杨迎东 《辽宁林业科技》 2024年第5期9-11,17,共4页
以食用百合大花卷丹为试验材料,运用随机区组设计方法,设定了种球顶端以上覆土5 cm、10 cm、15 cm,探究不同栽培深度对种球生长及产量的影响。结果表明:在栽培深度为5 cm时,收获大规格种球所占比例最高,主球鲜重增长率达到最大;当栽培... 以食用百合大花卷丹为试验材料,运用随机区组设计方法,设定了种球顶端以上覆土5 cm、10 cm、15 cm,探究不同栽培深度对种球生长及产量的影响。结果表明:在栽培深度为5 cm时,收获大规格种球所占比例最高,主球鲜重增长率达到最大;当栽培深度为10 cm时,收获种球的总鲜重最高,增产率最为显著;而栽培深度为15 cm时,收获的种球数量最多,增殖系数处于最高水平。研究结果为食用百合大花卷丹的科学栽培提供了重要依据,有助于种植者根据生产目标选择适宜的栽培深度,以实现优质高产。 展开更多
关键词 大花卷丹 栽培深度 增殖系数 种球产量
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8份强筋小麦品种抗旱性评价 被引量:2
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作者 张军 魏国 +5 位作者 彭彦珉 汪洪涛 黄修利 吴金芝 黄明 李友军 《麦类作物学报》 CAS CSCD 北大核心 2024年第4期442-452,共11页
为给强筋冬小麦品种的抗旱性评价和抗旱指标筛选提供理论依据,以黄淮麦区种植的8个强筋小麦品种为材料,在水培条件下设置正常供水(对照)和20%聚乙二醇(PEG-6000)模拟干旱胁迫两个处理,测定了萌发期11个抗旱相关指标、幼苗期20个抗旱相... 为给强筋冬小麦品种的抗旱性评价和抗旱指标筛选提供理论依据,以黄淮麦区种植的8个强筋小麦品种为材料,在水培条件下设置正常供水(对照)和20%聚乙二醇(PEG-6000)模拟干旱胁迫两个处理,测定了萌发期11个抗旱相关指标、幼苗期20个抗旱相关指标,计算各指标的抗旱系数,采用主成分分析法和隶属函数法求得综合抗旱能力评价值(D值),基于D值评价萌发期和幼苗期抗旱性;在旱棚池栽条件下,测定了2种水分处理下(适时一次灌溉、雨养)籽粒产量,基于产量抗旱系数评价全生育期抗旱性。结果表明:(1)干旱处理下,8个小麦品种萌发期发芽势、发芽率等10个抗旱指标显著低于对照,根冠比显著高于对照;幼苗期叶片净光合速率、气孔导度等13个抗旱指标不同程度地低于对照,胞间CO 2浓度、SOD活性等7个抗旱指标显著高于对照。(2)与适时一次灌溉相比,雨养条件下小麦籽粒产量显著降低,降幅18.70%~28.66%,产量抗旱系数为0.713~0.813。(3)8个强筋小麦品种在萌发期和幼苗期抗旱等级不尽相同。藁8901在2个生育时期均表现出抗旱性;科大1026、郑麦7698和丰德存麦5号在幼苗期表现出抗旱性,在萌发期对干旱敏感;新麦26、郑麦366、周麦32号和周麦36在2个生育时期均对干旱敏感。(4)产量抗旱系数与萌发期D值无显著相关性,但与幼苗期D值呈显著正相关。(5)经逐步回归分析,胞间CO 2浓度、蒸腾速率、CAT活性、脯氨酸含量、最大根长和总根长可作为强筋小麦品种苗期抗旱性鉴定的关键指标。 展开更多
关键词 强筋小麦 抗旱性 萌发期 幼苗期 产量抗旱系数 相关性
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不同燃料外配比例烧结杯试验及烧结矿冶金性能试验
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作者 鲁逢霖 《酒钢科技》 2024年第1期16-21,共6页
本文针对酒钢烧结生产中存在的问题,系统研究了不同燃料外配比例对烧结垂直烧结速度、成品率、利用系数、烧结时间、转鼓强度及烧结矿冶金性能等指标的影响。试验结果表明:随着燃料外配比例的增加,烧结利用系数呈先提高后降低的趋势,综... 本文针对酒钢烧结生产中存在的问题,系统研究了不同燃料外配比例对烧结垂直烧结速度、成品率、利用系数、烧结时间、转鼓强度及烧结矿冶金性能等指标的影响。试验结果表明:随着燃料外配比例的增加,烧结利用系数呈先提高后降低的趋势,综合考虑最佳的燃料外配比例为60%;随着燃料外配比例的增加,烧结矿低温还原粉化率RDI_(+3.15mm)、烧结矿900℃还原度、烧结矿软化熔滴性能均变化不大,基本持平。 展开更多
关键词 不同燃料外配比例 烧结杯试验 烧结矿冶金性能 利用系数 成品率
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不同钝化剂对镉污染小麦镉富集及产量的影响
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作者 贾彪 赵宝平 +6 位作者 张茹 鲁瑞英 王永宁 郭晓宇 陈淼 雷雪峰 刘景辉 《麦类作物学报》 CAS CSCD 北大核心 2024年第5期648-657,共10页
为实现河套灌区轻中度Cd污染农田的修复与安全利用,在河套灌区轻中度Cd污染农田开展了为期两年不同钝化剂处理的大田试验,7种钝化剂分别为生物炭(BC)、海泡石(SEP)、膨润土(BE)、坡缕石(PA)、腐植酸(HA)、硅酸钠(SS)、硫酸锰(MN),以不... 为实现河套灌区轻中度Cd污染农田的修复与安全利用,在河套灌区轻中度Cd污染农田开展了为期两年不同钝化剂处理的大田试验,7种钝化剂分别为生物炭(BC)、海泡石(SEP)、膨润土(BE)、坡缕石(PA)、腐植酸(HA)、硅酸钠(SS)、硫酸锰(MN),以不施用钝化剂为对照(CK),分析了不同处理下小麦产量、生物量、各器官Cd富集系数和转运系数,比较了不同钝化剂的钝化效果。结果表明,2020-2021年,SEP和SS处理较CK增产显著,增幅为11.09%~81.49%,各器官生物量均有不同程度的增加,其中籽粒及根增加显著;SS处理显著降低叶部Cd含量,降幅为26.75%,SEP处理显著降低籽粒Cd含量,降幅达47.62%。钝化剂处理下,各部位Cd富集系数均<1,根部到叶部Cd最高。小麦籽粒Cd含量与茎中Cd富集系数呈极显著的正相关,与茎向叶部、根向穗部的Cd转运系数呈显著的正相关;2年茎的Cd富集系数对籽粒Cd富集系数均有显著正效应,穗到籽粒、茎到叶的Cd转运系数对籽粒Cd富集系数影响最大。海泡石和硅酸钠处理增加了小麦产量,降低了植株Cd含量,抑制了Cd在植株体内的转运富集;内蒙古河套灌区轻中度Cd污染农田,推荐施用硅酸钠和海泡石进行小麦安全生产。 展开更多
关键词 镉污染 小麦 转运系数 富集系数 生物量 产量
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不同施肥处理对夏玉米产量及肥料利用率的影响
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作者 李娜 张志伟 +1 位作者 李艳红 石德杨 《安徽农业科学》 CAS 2024年第16期130-132,共3页
以玉米登海605为试验对象,探讨不同施肥处理对土壤理化性状、秸秆和籽粒中氮磷钾含量、玉米产量及经济系数的影响,测算夏玉米氮肥、磷肥和钾肥的利用率。结果表明,不同施肥处理降低了土壤pH及有机质、碱解氮、有效磷含量;氮磷钾全量施... 以玉米登海605为试验对象,探讨不同施肥处理对土壤理化性状、秸秆和籽粒中氮磷钾含量、玉米产量及经济系数的影响,测算夏玉米氮肥、磷肥和钾肥的利用率。结果表明,不同施肥处理降低了土壤pH及有机质、碱解氮、有效磷含量;氮磷钾全量施肥提高了夏玉米籽粒和秸秆产量及籽粒和秸秆养分吸收量。夏玉米氮肥、磷肥和钾肥的利用率分别为32.96%、14.25%、41.67%,综合肥料利用率为40.34%,玉米经济系数为0.47~0.51。 展开更多
关键词 夏玉米 肥料利用率 产量 经济系数
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超高桥塔混凝土泵送性能优化试验研究
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作者 黄涛 潘利 +1 位作者 毛永琳 徐文 《混凝土与水泥制品》 2024年第11期17-21,共5页
以常泰长江大桥工程为背景,采用一种基于流变仪摩擦计测试流变性能的试验方法,研究了水胶比、同胶凝材料总量、砂率对超高桥塔混凝土工作性及泵送性能的影响,并分析了泵管管径、泵送排量对泵送性能的影响。结果表明:适当提高水胶比、增... 以常泰长江大桥工程为背景,采用一种基于流变仪摩擦计测试流变性能的试验方法,研究了水胶比、同胶凝材料总量、砂率对超高桥塔混凝土工作性及泵送性能的影响,并分析了泵管管径、泵送排量对泵送性能的影响。结果表明:适当提高水胶比、增加胶凝材料总用量、增加砂率均对改善混凝土的工作性与泵送性能有利;流变改性材料的掺入可大幅降低润滑层的黏度系数与混凝土的泵送阻力。 展开更多
关键词 泵送阻力 润滑层 黏度系数 混凝土 屈服应力 泵送性能
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灌浆初期高温胁迫对水稻籽粒活性氧积累及产量形成的影响
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作者 刘晓龙 叶世河 +9 位作者 廖俊婕 骆依菲 龙莎 廖婧芃 钟歆 谢菲 谢子怡 曾鹏 胡永轩 徐晨 《西北农林科技大学学报(自然科学版)》 CSCD 北大核心 2024年第5期33-47,共15页
【目的】研究灌浆初期高温胁迫对水稻籽粒活性氧积累及产量形成的影响,为耐热水稻种质资源的筛选和鉴定提供理论依据。【方法】以长江中下游地区普遍推广种植的8个水稻品种为材料,在灌浆初期进行高温胁迫(38℃/32℃,昼/夜),研究各水稻... 【目的】研究灌浆初期高温胁迫对水稻籽粒活性氧积累及产量形成的影响,为耐热水稻种质资源的筛选和鉴定提供理论依据。【方法】以长江中下游地区普遍推广种植的8个水稻品种为材料,在灌浆初期进行高温胁迫(38℃/32℃,昼/夜),研究各水稻品种在灌浆初期高温胁迫下的ROS含量、抗氧化酶活性、淀粉合成相关酶活性、产量及其构成要素以及稻米品质的差异。【结果】与对照相比,灌浆初期高温胁迫导致水稻籽粒O_(2)^(-·)和H_(2)O_(2)含量及抗氧化酶活性显著增加。在不同水稻品种中,淀粉合成相关酶活性对灌浆初期高温胁迫的响应具有差异性。高温胁迫下,产量损失较大水稻品种的O_(2)^(-·)和H_(2)O_(2)含量增幅较大,淀粉合成酶活性受高温胁迫影响也较大。灌浆初期高温胁迫导致水稻结实率、千粒质量、收获指数和产量显著下降,其中黄华占和湘两优900的产量损失较小,在灌浆初期的耐热性较强;粤王丝苗、泰优390和湘两优2号的产量损失较大,在灌浆初期的耐热性弱。灌浆初期高温胁迫导致糙米率、精米率和淀粉含量显著下降,垩白粒率和垩白度增加。高温胁迫下,产量损失较大水稻品种的淀粉含量下降幅度较大,稻米品质受高温胁迫影响也较大。在高温胁迫下,水稻产量与ROS含量显著负相关,而与抗氧化酶活性显著正相关。产量、籽粒加工指标、淀粉含量和淀粉合成酶活性的抗逆系数与ROS含量的抗逆系数显著负相关,而与抗氧化酶活性的抗逆系数显著正相关。【结论】灌浆初期高温胁迫导致水稻籽粒ROS过量积累是降低淀粉合成酶活性和淀粉含量,进而导致产量和稻米外观加工品质下降的重要因素。ROS的增加量可作为灌浆初期水稻耐热性评价的参考指标。 展开更多
关键词 水稻 高温胁迫 籽粒产量 抗逆系数 耐热品种
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基于主成分分析和隶属函数法筛选低镉高产辣椒品种
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作者 黄鑫浩 许洪扬 +4 位作者 缪武 雷佳奇 金雨珂 郑井元 朱凡 《湖南农业大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第5期44-53,共10页
为筛选高产且适合在轻度镉(Cd)污染土壤中种植的低镉积累辣椒品种,选取了4个辣椒类型(朝天椒、泡椒、牛角椒、线椒)主产区的12个主栽品种为供试材料,通过Cd污染(2.5 mg/kg)土壤盆栽试验,研究不同辣椒品种中Cd积累量的差异,分析Cd对光合... 为筛选高产且适合在轻度镉(Cd)污染土壤中种植的低镉积累辣椒品种,选取了4个辣椒类型(朝天椒、泡椒、牛角椒、线椒)主产区的12个主栽品种为供试材料,通过Cd污染(2.5 mg/kg)土壤盆栽试验,研究不同辣椒品种中Cd积累量的差异,分析Cd对光合色素、光合能力、产量的影响,并通过主成分分析和隶属函数法从果实Cd含量、产量和光合能力等3个维度筛选具有低Cd、高产特性的辣椒品种。结果表明:12个辣椒品种中长兴8号和龙福椒的单株产量较高,分别为402.35、384.26 g,显著高于其他品种;供试辣椒品种中根、茎、叶、果中的Cd含量依次降低;4个类型中,牛角椒的根和茎富集系数最高,线椒的根和茎富集系数最低,朝天椒叶片的富集系数最低;长兴8号、湘辛28号、龙福椒的果实富集系数较低;龙福椒鲜果中Cd含量最低,为0.11 mg/kg;目标危险系数(THQ)显示,健康风险较高的是星秀(1.373)、橙艳(1.125)和湘辣699(1.152),较低的是龙福椒(0.587)、湘辛28号(0.722)、长兴8号(0.732);Cd对叶片CO_(2)同化效率的抑制程度高于其对光化学效率的抑制程度,Pn和Fv/Fm共同影响辣椒在Cd处理下的产量,路径系数分别为0.58和0.37;通过综合评价值,龙福椒具备低镉高产的特性,可优先考虑在轻度Cd污染农田推广种植。 展开更多
关键词 辣椒 高产 主成分分析 隶属函数法 富集系数
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南疆陆地棉农艺性状与皮棉产量性状的遗传贡献及决策系数分析
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作者 李长喜 董占鹏 +3 位作者 关永虎 刘金伟 李航 梅拥军 《作物学报》 CAS CSCD 北大核心 2024年第6期1486-1502,共17页
研究陆地棉亲本及F1组合农艺性状与皮棉产量性状的遗传,为育种工作者对某些性状的选择和改良提供参考依据。采用加性-显性及其与环境互作的遗传模型对130个陆地棉品种(系)及其206个F1组合的4个农艺性状和4个产量性状的观察结果进行了遗... 研究陆地棉亲本及F1组合农艺性状与皮棉产量性状的遗传,为育种工作者对某些性状的选择和改良提供参考依据。采用加性-显性及其与环境互作的遗传模型对130个陆地棉品种(系)及其206个F1组合的4个农艺性状和4个产量性状的观察结果进行了遗传贡献分析和决策系数分析。分析结果显示,这些性状具有丰富的遗传多样性,亲本的8个性状的变异系数在5.54%~50.83%之间, F1组合则在3.96%~55.87%之间。农艺性状(除第一果枝节位对衣分外)对产量性状的加性贡献率均达到极显著水平(贡献率在4%~100%),五瓣铃率和株高对单株铃数和铃重的加性贡献率和显性×环境互作贡献率均达0.01以上的正向极显著水平。遗传效应中受加性效应控制有第一果枝高度、株高、五瓣铃率、铃重和衣分,其中衣分为最大。株高除加性效应较小外,其显性效应、加性×环境互作效应、显性×环境互作效应和互作广义遗传率均为最大。确定了提高陆地棉杂交种后代单株皮棉产量的主要决策性状和限制性状。陆地棉变异系数幅度较大;五瓣铃率和株高对提高单株铃数和铃重起着更为重要的作用;单株铃数、铃重和衣分是提高单株皮棉产量的主要决策性状。 展开更多
关键词 陆地棉 产量性状 农艺性状 遗传多样性 遗传贡献分析 决策系数分析
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