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基于场量梯度的快照分区POD降阶计算方法
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作者 杨帆 张潋镪 +2 位作者 何永胜 王鹏博 姜慧 《高电压技术》 北大核心 2025年第1期31-39,共9页
随着数字化电力系统的不断发展,对高价值电力装备数字孪生模型的研究成为热点。为满足计算的时效性,通常采用模型降阶的方法,其中本征正交分解法(proper orthogonal decomposition,POD)是最为常用的方法之一。传统的POD方法在构造快照... 随着数字化电力系统的不断发展,对高价值电力装备数字孪生模型的研究成为热点。为满足计算的时效性,通常采用模型降阶的方法,其中本征正交分解法(proper orthogonal decomposition,POD)是最为常用的方法之一。传统的POD方法在构造快照时无法高效提取网格节点信息,造成大的计算量、存储资源浪费。为此,该文提出基于场量梯度的快照分区POD降阶计算方法,以快照中各节点场量梯度为依据对计算域进行分区处理,通过对不同分区的节点数量进行不同程度的缩减,实现了高效的POD降阶计算。以换流变阀侧套管极性反转电场作为算例,对该文提出分区降阶方法的可行性及高效性进行了验证。研究结果显示:相较于有限元方法,计算时间缩短97.1%,同时相较于传统的POD方法,其快照中节点数量减少95.2%,节约存储资源91.7%。同时,分区降阶计算的准确率高,平均误差仅为0.80%,实现了对阀侧套管极性反转电场的高效计算。 展开更多
关键词 模型降阶方法 本征正交分解法 场量大梯度 pod快照 换流变 阀侧套管
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Silent information regulator sirtuin 1 ameliorates acute liver failure via the p53/glutathione peroxidase 4/gasdermin D axis 被引量:6
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作者 Xing-Nian Zhou Quan Zhang +6 位作者 Hong Peng Yu-Jie Qin Yu-Hong Liu Lu Wang Ming-Liang Cheng Xin-Hua Luo Hong Li 《World Journal of Gastroenterology》 SCIE CAS 2024年第11期1588-1608,共21页
BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple b... BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF. 展开更多
关键词 Silent information regulator sirtuin 1 Ferroptosis PYROPTOSIS p53/glutathione peroxidase 4/gasdermin D Acute liver failure
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基于A,Ф-A的变压器三维涡流场时域有限元POD降阶方法及其应用
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作者 朱章宸 刘尧 +1 位作者 刘刚 刘云鹏 《华北电力大学学报(自然科学版)》 北大核心 2025年第1期82-94,共13页
为解决三维涡流场时域求解时间长和存储空间需求较多的问题,首先基于A,Ф-A的三维涡流场时域有限元法结合POD(Proper Orthogonal Decomposition,POD)降阶算法实现了三维涡流场的高效计算。其次,以国际TEAM第21基准问题的模型B为例,通过... 为解决三维涡流场时域求解时间长和存储空间需求较多的问题,首先基于A,Ф-A的三维涡流场时域有限元法结合POD(Proper Orthogonal Decomposition,POD)降阶算法实现了三维涡流场的高效计算。其次,以国际TEAM第21基准问题的模型B为例,通过对比分析实测数据与自编程序和COMSOL的计算结果,验证了A,Ф-A的三维涡流场时域有限元求解方法的有效性。然后,通过POD不同阶数的降阶算例验证了POD降阶方法的有效性。最后,利用所提的基于A,Ф-A三维涡流场时域有限元法计算了一台三相变压器进行额定运行工况下的涡流场,并将计算结果与COMSOL仿真结果进行了对比。同时,还分析了三相变压器在负荷减少过程中的相电流和磁场变化,并分析了降阶模型阶数对计算时间和精度的影响,结果表明:15阶降阶模型耗时约为全阶耗时1/10,并且在方程降阶后各时间步的加速比最大,可达到70~165倍,在计算涡流损耗时相对误差不超过4.59%,计算精度相对较高。 展开更多
关键词 三维涡流场 三相变压器 A Ф-A方法 pod降阶方法
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新疆小麦过氧化物酶活性基因TaPod-A1、TaPod-A3和TaPod-D1等位变异及分布规律
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作者 刘鑫源 程宇坤 +4 位作者 王丽丽 战帅帅 马孟瑶 郭玲 耿洪伟 《作物学报》 CAS 北大核心 2025年第1期68-78,共11页
小麦面粉的颜色是其品质分级的重要指标,为了使小麦面粉的品质得到进一步提升,本研究利用位于TaPod-A1、TaPod-A3和TaPod-D1位点基因的功能标记对110份新疆小麦品种(系)进行等位变异基因检测。基因型与表型方差分析结果显示, TaPod-A1、... 小麦面粉的颜色是其品质分级的重要指标,为了使小麦面粉的品质得到进一步提升,本研究利用位于TaPod-A1、TaPod-A3和TaPod-D1位点基因的功能标记对110份新疆小麦品种(系)进行等位变异基因检测。基因型与表型方差分析结果显示, TaPod-A1、TaPod-A3和TaPod-D1位点的等位变异类型TaPod-A1b (35.5%)、TaPod-A3c (53.6%)和TaPod-D1b(60%)较其他等位变异类型TaPod-A1a (64.5%)、TaPod-A3a (46.4%)和TaPod-D1a(40%)均具有较高的POD活性。在新疆小麦材料中, TaPod-A1、TaPod-A3和TaPod-D1的3个不同基因位点上高POD活性的优异等位变异类型的分布频率均表现为引进品种(系)≈自育品种(系)>地方品种。TaPod-A3b在110份新疆小麦材料中并未检测出,说明该等位变异为稀有等位变异。具有TaPod-A1、TaPod-A3和TaPod-D1基因等位变异组合品种(系)的平均POD活性高低依次为TaPod-A1b/TaPod-A3c/TaPod-D1b (2836.25 U g^(–1) min^(–1))> TaPod-A1b/TaPod-A3c/TaPod-D1a (2796.00 U g^(–1)min^(–1))> TaPod-A1b/TaPod-A3a/TaPod-D1b(2520.31Ug^(–1)min^(–1))> TaPod-A1a/TaPod-A3c/TaPod-D1b(2473.91Ug^(–1)min^(–1))> TaPod-A1a/TaPod-A3a/TaPod-D1b(2407.65Ug^(–1)min^(–1))> TaPod-A1b/TaPod-A3a/TaPod-D1a(2339.06Ug^(–1)min^(–1))> TaPod-A1a/TaPod-A3c/TaPod-D1a(2320.38Ug^(–1)min^(–1))> TaPod-A1a/TaPod-A3a/TaPod-D1a(2210.69Ug^(–1)min^(–1))。其中,具有TaPod-A1b/TaPod-A3c/TaPod-D1b等位变异基因的活性(2836.25Ug^(–1)min^(–1))极显著高于具有TaPod-A1a/TaPod-A3a/TaPod-D1a(2210.69Ug^(–1)min^(–1))(P<0.01)的品种,说明具有较多优异等位变异类型的品种具有较高的POD活性。 展开更多
关键词 小麦 过氧化物酶 等位变异 分子标记检测
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茶树DREB基因的生信分析及其调控CsPOD3的抗旱机制
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作者 徐容 邓智英 +6 位作者 邵陈禹 罗玉麒 仇舒琪 王聪 周玲红 刘仲华 沈程文 《茶叶科学》 北大核心 2025年第1期29-42,共14页
基于课题组前期的转录组数据筛选到CsDREB11、CsDREB15和CsDREB25等基因。通过RT-qPCR验证,它们均受干旱诱导表达。从进化树、蛋白理化性质、亲/疏水性、二级和三级结构、亚细胞定位等方面进行预测与分析。结果表明,CsDREB11、CsDREB15... 基于课题组前期的转录组数据筛选到CsDREB11、CsDREB15和CsDREB25等基因。通过RT-qPCR验证,它们均受干旱诱导表达。从进化树、蛋白理化性质、亲/疏水性、二级和三级结构、亚细胞定位等方面进行预测与分析。结果表明,CsDREB11、CsDREB15和CsDREB25都与狭叶油茶(Camellialanceoleosa)的亲缘性最为密切,都属于不稳定的亲水性蛋白。二级/三级结构均以无规则卷曲和α-螺旋为主,其亚细胞定位均位于细胞核中。课题组前期的研究发现CsDREB25与CsPOD3均在干旱下高表达且呈显著相关,推测CsDREB25和CsPOD3存在相互作用关系。通过酵母单杂交验证(Y1H)和双荧光素酶报告基因检测(DLA)以及双荧光素酶互补成像(LCI)等方法试验验证了CsDREB25能正向调控CsPOD3的表达,提高POD的活性,清除过多活性氧,提高茶树的耐旱性。 展开更多
关键词 茶树 干旱胁迫 DREBs 过氧化物酶 生物信息学分析
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基于高光谱成像技术的西瓜叶片CAT和POD活性模型构建
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作者 马燕 马玲 +3 位作者 马思艳 王静 张祎洋 吴龙国 《现代农业科技》 2025年第6期169-174,共6页
利用高光谱成像技术建立西瓜叶片过氧化氢酶(CAT)、过氧化物酶(POD)活性的预测模型。采用归一化处理(NL)、高斯滤波平滑(GF)、标准正态变化(SNV)、正交信号校正(OSC)和移动平均法(MA)5种方法对原始光谱进行预处理,运用竞争性自适应加权... 利用高光谱成像技术建立西瓜叶片过氧化氢酶(CAT)、过氧化物酶(POD)活性的预测模型。采用归一化处理(NL)、高斯滤波平滑(GF)、标准正态变化(SNV)、正交信号校正(OSC)和移动平均法(MA)5种方法对原始光谱进行预处理,运用竞争性自适应加权算法(CARS)、连续投影算法(SPA)、无信息变量消除变换法(UVE)、遗传偏最小二乘算法(GAPLS)4种方法提取特征波长,基于优选的特征波长建立了偏最小二乘回归(PLSR)、多元线性回归(MLR)和主成分回归(PCR)预测模型。结果表明,PLSR-GAPLS构建CAT活性的预测模型效果较优(RC=0.85,RCV=0.61,RP=0.66),PLSR-UVE构建POD活性的预测模型效果较优(RC=0.92,RCV=0.85,RP=0.84)。研究结果可以为宁夏硒砂瓜精细化栽培提供数据支撑和理论依据,为西瓜生长信息无损检测提供技术支持。 展开更多
关键词 高光谱成像技术 西瓜叶片 SOD活性 pod活性 模型构建 无损检测
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基于POD-DNN降阶模型的油浸式变压器绕组稳态温升快速计算方法
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作者 赵庆贤 刘云鹏 +3 位作者 刘刚 傅榕韵 邹莹 武卫革 《中国电机工程学报》 北大核心 2025年第6期2423-2436,I0033,共15页
为解决油浸式变压器绕组稳态温升计算耗时久的问题,该文提出一种基于POD-DNN降阶模型的快速计算方法。首先,通过绕组稳态温升全阶模型构建快照矩阵,并基于本征正交分解(proper orthogonal decomposition,POD)获得物理系统的模态及模态... 为解决油浸式变压器绕组稳态温升计算耗时久的问题,该文提出一种基于POD-DNN降阶模型的快速计算方法。首先,通过绕组稳态温升全阶模型构建快照矩阵,并基于本征正交分解(proper orthogonal decomposition,POD)获得物理系统的模态及模态系数。然后,建立工况参数与模态系数间的深度神经网络(deep neural networks,DNN)代理模型,解决POD方法中非线性项求解效率低和控制方程依赖强的局限,同时设计网络正则化策略,避免小样本下模型过拟合。最后,将DNN代理模型预测的模态系数与对应的POD模态线性加权,重构绕组温度场。经验证,POD-DNN求解的绕组温升结果与Fluent仿真和试验测量高度一致,计算效率相较于全阶模型和Fluent仿真分别提升了247478倍和23056倍,该算法能够为变压器的在线监测、运行维护和绝缘设计提供技术支撑。 展开更多
关键词 本征正交分解 深度神经网络 绕组稳态温升 快速计算 降阶模型
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Pods Filling in Natural Pollination of 10 Spontaneous Cocoa Trees from French Guiana
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作者 Inago Caudou Trebissou Gnion Mathias Tahi Kacou Antoine Alban M’bo 《Agricultural Sciences》 2025年第1期193-205,共13页
The study focuses on the filling of pods from ten cacao clones originating from French Guiana in Côte d’Ivoire. Two reference clones (IFC5 and NA32) were used as controls. The parameters studied include the numb... The study focuses on the filling of pods from ten cacao clones originating from French Guiana in Côte d’Ivoire. Two reference clones (IFC5 and NA32) were used as controls. The parameters studied include the number of ovules per ovary, the average number of beans per pod, the fresh bean weight, and the pod index. The aim was to evaluate the genetic variability and agronomic performance of these clones under natural pollination conditions. The results show significant genetic variability between the clones for all traits studied. The IFC5 clone, known for its excellent pod filling, exhibited the highest apparent fertility (0.91), while the GU183/A clone had the lowest filling (0.47). Three types of distributions of the number of beans per pod were identified: a right-skewed unimodal distribution, characteristic of well-filled clones;a left-skewed unimodal distribution, associated with poorly filled clones;and an intermediate bimodal distribution. These differences could be related to pollination compatibility and the availability of compatible pollen. Regarding the fresh bean weight and pod index, the GU183/A clone stood out with the heaviest beans (3.27 g) but had a high pod index (49.58), indicating relatively low productivity. None of the Guyanese clones achieved the filling level of the IFC5 clone, although some surpassed the NA32 control. This study highlights the importance of apparent fertility and the number of beans per pod as essential criteria for cacao genetic improvement programs. The authors recommend extending research to a larger number of Guyanese clones and exploring complementary traits, such as the influence of pollination type and intergroup compatibility. 展开更多
关键词 Theobroma cacao PHYTOPHTHORA pod Index Apparent Fertility
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木薯MePOD10基因克隆及原核表达分析
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作者 何雪强 吴姝 +4 位作者 林慧靖 陈奥 王苗 史钊辉 闫语 《福建农业学报》 北大核心 2025年第1期10-17,共8页
【目的】克隆木薯(Manihot esculenta Crantz)过氧化物酶基因MePOD10并进行生物信息学分析、原核表达分析和蛋白酶动力学分析,为进一步研究MePOD10基因的功能提供参考。【方法】从木薯‘华南124’('South China 124','SC124... 【目的】克隆木薯(Manihot esculenta Crantz)过氧化物酶基因MePOD10并进行生物信息学分析、原核表达分析和蛋白酶动力学分析,为进一步研究MePOD10基因的功能提供参考。【方法】从木薯‘华南124’('South China 124','SC124')中扩增MePOD10基因编码区序列(coding sequence,CDS),对其进行生物信息学分析,并构建MePOD10-pET28a融合表达载体,再转化至BL21感受态细胞中进行蛋白诱导,通过SDS-PAGE以及Western blotting确定MePOD10蛋白的表达情况,纯化MePOD10蛋白后进行酶活性和动力学分析。【结果】MePOD10基因CDS序列长度为981 bp,编码326个氨基酸,蛋白分子量为35069.60 Da,理论等电点为6.59,属于不稳定疏水性蛋白。MePOD10含有植物过氧化物酶保守结构域,其氨基酸序列与橡胶树POD蛋白的相似性最高,为93.25%。在37℃、1 mmol·L^(-1)异丙基-β-D-硫代半乳糖苷(Isopropylβ-D-Thiogalactoside,IPTG)诱导6 h条件下,上清和沉淀均有蛋白表达,纯化后的上清蛋白酶活性高于对照蛋白,以愈创木酚为底物时,随着底物浓度增加,MePOD10蛋白催化活性迅速增加,之后趋于平稳,说明MePOD10蛋白具有催化活性。【结论】MePOD10蛋白具有过氧化物酶(Peroxidase,POD)保守结构域,在37℃、1 mmol·L^(-1)IPTG诱导6 h条件下,MePOD10-pET28a融合蛋白能正确表达,纯化后的融合蛋白具有催化活性。 展开更多
关键词 木薯 过氧化物酶 原核表达 酶活性
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A morphological and anatomical study for tracking the growth and development of individual flowers and pods in soybean(Glycine max L.)
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作者 Fang Li Yi-Ping Shao +4 位作者 Irsa Ejaz Zhen-Yuan Chen Zhi-Wei Wang Xin Wang Shun-Li Zhou 《The Crop Journal》 2025年第1期304-309,共6页
A morphology-based growth stage system should describe the growth and development of a crop and thereby help farmers and agronomists in formulating reasonable managementmeasures conducive to the development of marketa... A morphology-based growth stage system should describe the growth and development of a crop and thereby help farmers and agronomists in formulating reasonable managementmeasures conducive to the development of marketable products.However,existing growth stage systems for soybean are either based on plant growth or covered particular phases of flower or pod development,making it difficult to use for tracking the entire growth period of individual flowers and pods.Therefore,the first flower and pod,located at the base of the primary raceme in the eighth trifoliate node of the main stem,were chosen to illustrate growth dynamics during the full reproductive period.The size and fresh weight of the primary raceme in the eighth trifoliate leaf axil,the first flower and pod,the pistils in the first flower,and seeds in the first pod were examined,and the growth of these organs was depicted.Integrating the morphological characteristics and growth features of flowers and pods,as well as existing growth stage systems,the growth and development were delineated in 13 stages.In detail,we classified the flower phase based on the relative positions of floral components,inspired by the ratio of bract to flower used for staging,refined the lag phase proposed previously,retained the use of pod length to define the early pod phase,and innovatively described the late pod phase by the seed appearance.The developmental events in each stage of flower and pod were distinctive and closely connected to the corresponding morphology.Taken together,a more detailed growth stage system for describing individual flowers and pods in soybean was established.This system will serve as a valuable research tool for describing the development,gene expression,and cellular metabolism associated with the formation of flowers,pods,and seeds. 展开更多
关键词 SOYBEAN Growth stage system Flower and pod Morphology ANATOMY Growth and development
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融合离散节点温度与非侵入式POD方法的变压器绕组温度场快速计算
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作者 刘浩宇 高树国 +3 位作者 臧谦 郭猛 张志刚 代璐健 《高电压技术》 北大核心 2025年第1期88-96,共9页
为提高油浸式电力变压器绕组温度的计算效率,提出了一种融合离散节点温度与非侵入式本征正交分解(proper orthogonal decomposition,POD)的快速计算方法。首先,采用POD方法建立绕组温度计算的降阶模型,获得反映绕组温度场分布特征的降... 为提高油浸式电力变压器绕组温度的计算效率,提出了一种融合离散节点温度与非侵入式本征正交分解(proper orthogonal decomposition,POD)的快速计算方法。首先,采用POD方法建立绕组温度计算的降阶模型,获得反映绕组温度场分布特征的降阶模态;然后,选取场域内若干离散节点,建立节点温度与绕组工况相关的响应面模型;最后,借助降阶计算模型构建离散节点温度与绕组全场域温度之间的数学关系,实现从绕组工况到离散节点温度,再到全场域温度的快速反演。利用该文所提方法对110 kV油浸式变压器2维绕组传热模型进行分析,算例结果表明,温度场的最大平均绝对误差不超过0.49 K,最大平均相对误差不超过2.69%,热点温度最大误差不超过1.72 K;绕组温度分布计算时间仅为0.78 s,相较于全阶计算效率提升近千倍,充分说明了该算法的准确性与高效性,对变压器高精度数字孪生模型的建立具有重要意义,为实现数字孪生模型对物理实体的快速感知和主动预警提供了新思路。 展开更多
关键词 油浸式变压器 本征正交分解 离散节点 非侵入式 降阶计算
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Effects of Hg^(2+) on Isozymes of Peroxidase,Catalase and Superoxide Dismutase in Wheat Seedlings 被引量:20
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作者 王琳 王林嵩 +4 位作者 王丽 孙向东 宗秀征 李芳军 高雅 《Agricultural Science & Technology》 CAS 2008年第5期19-23,共5页
[Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedl... [Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedlings under Hg2+ stress at different concentrations.[Result]① There were no obvious effects on the growth of seedlings when the concentration of Hg2+ was lower than 0.10 mmol/L.However,toxic effects on the growth of seedling were observed when the concentration of Hg2+ was higher than 0.10 mmol/L.② Different tissues showed different resistant ability in response to Hg2+ stress.The leaves and roots of wheat seedlings were more insensitive to Hg2+ toxicity.③ CAT was more sensitive to Hg2+ stress compared to POD and SOD.[Conclusion]The toxic effect was related to the concentration of Hg2+(0.10 mmol/L).The higher concentration of Hg2+ could affect the expression of POD,CAT,and SOD isozymes in the leaves,roots of wheat seedlings and germinated seeds,which further affect the normal metabolism of membrane lipid and inhibit the growth of wheat seedlings at last. 展开更多
关键词 Wheat Hg2+ stress peroxidase CATALASE Superoxide DISMUTASE ISOZYME
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Effects of Catalase and Ascorbate Peroxidase on the Root Growth of Rice under Cadmium Stress 被引量:9
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作者 宋新华 王凯 +1 位作者 郭蕾蕾 赵凤云 《Agricultural Science & Technology》 CAS 2011年第9期1256-1259,共4页
[Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua ... [Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd+CAT inhibitor,Cd+APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice 展开更多
关键词 Cd stress CATALASE Ascorbate peroxidase
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Regulation of Heat Shock Factor AtHsfA1a on Ascorbate Peroxidase under Heat Stress in Arabidopsis thaliana 被引量:1
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作者 郭丽红 谭越 杨晓虹 《Agricultural Science & Technology》 CAS 2016年第8期1786-1789,共4页
[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic ... [Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant. 展开更多
关键词 Arabidopsis thaliana Heat shock factor AtHsfAla Aascorbate peroxidase Heat stress
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基于POD-αATS的油浸变压器瞬态温升降阶自适应变步长计算方法 被引量:4
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作者 刘刚 郝世缘 +2 位作者 胡万君 刘云鹏 李琳 《中国电机工程学报》 EI CSCD 北大核心 2024年第16期6656-6666,I0030,共12页
针对油浸式电力变压器瞬态温升计算效率过低的问题,该文提出本征正交分解-αATS(proper orthogonal decomposition-adaptive time stepping based onαfactor,POD-αATS)降阶自适应变步长瞬态计算方法。首先,推导变压器绕组瞬态温升计... 针对油浸式电力变压器瞬态温升计算效率过低的问题,该文提出本征正交分解-αATS(proper orthogonal decomposition-adaptive time stepping based onαfactor,POD-αATS)降阶自适应变步长瞬态计算方法。首先,推导变压器绕组瞬态温升计算的有限元离散方程;其次,采用POD降阶算法改善传统瞬态计算中存在的条件数过大及方程阶数过高的问题;同时对于瞬态计算中的时间步长选择问题,提出适用于非线性问题的αATS变步长策略;然后,为验证方法的有效性,基于110 kV油浸式电力变压器绕组的基本结构建立二维八分区数值计算模型,同时将计算结果与基于110 kV绕组的温升实验结果进行对比。数值计算及实验结果表明,所提算法与全阶定步长算法在流场和温度场中的精度几乎相同,且流场计算效率提升约45倍,温度场计算效率提升约38倍,计算速度得到显著提高。这一点在温升实验中同样得到验证,说明该文所提算法的准确性、高效性及一定的工程实用性。 展开更多
关键词 αATS变步长算法 本征正交分解降阶方法 瞬态流热耦合问题 快速计算方法 温升实验
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基于POD和Kriging的水滴收集量快速预测方法 被引量:1
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作者 郭琪磊 杜杰 张恒 《南京航空航天大学学报》 CAS CSCD 北大核心 2024年第2期318-326,共9页
数值模拟手段预测翼面处水滴撞击特性通常较为耗时,为快速准确计算结冰条件下的翼面处水滴收集量,提出了基于本征正交分解和代理模型的水滴收集量快速预测方法。首先对FAR 25部附录C中连续最大结冰条件进行优化拉丁超立方采样,通过数值... 数值模拟手段预测翼面处水滴撞击特性通常较为耗时,为快速准确计算结冰条件下的翼面处水滴收集量,提出了基于本征正交分解和代理模型的水滴收集量快速预测方法。首先对FAR 25部附录C中连续最大结冰条件进行优化拉丁超立方采样,通过数值模拟手段获得各采样点在翼面处水滴收集量分布,从而构造样本空间。在此基础上,利用本征正交分解(Proper orthogonal decompostion,POD)方法找到表达和重构水滴收集量的本征模态以及相应的拟合系数。最后,利用Kriging模型建立样本空间中各采样点与拟合系数间的代理模型,实现翼面处水滴收集量分布的快速预测。经多组工况验证表明:该方法可较为准确地预测翼面处水滴收集量分布,其计算成本较数值模拟方法大幅降低,能够为无人机防除冰设计提供有益参考。 展开更多
关键词 无人机 防/除冰 本征正交分解 代理模型 水滴收集量
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面向数字孪生模型应用的油浸式变压器绕组温度POD-RBFLP降阶计算方法 被引量:3
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作者 刘刚 胡万君 +4 位作者 郝世缘 高成龙 武卫革 刘云鹏 李琳 《中国电机工程学报》 EI CSCD 北大核心 2024年第11期4566-4578,I0034,共14页
了解油浸式电力变压器绕组的温度情况是保证其运行稳定性的关键,也是当前针对油浸式变压器数字孪生分析的必然需求。为了快速地获得变压器绕组的稳态温度,该文提出一种基于本征正交分解(proper orthogonal decomposition,POD)和包含线... 了解油浸式电力变压器绕组的温度情况是保证其运行稳定性的关键,也是当前针对油浸式变压器数字孪生分析的必然需求。为了快速地获得变压器绕组的稳态温度,该文提出一种基于本征正交分解(proper orthogonal decomposition,POD)和包含线性多项式的径向基函数响应面法(radial basis function response surface method including linear polynomial,RBFLP)的降阶计算模型。首先,讨论POD方法的降阶特性,并设计一种基于留一法交叉验证的自适应获得快照矩阵方法,以提高计算精度及效率;其次,采用响应面方法建立POD模态系数与绕组工况的相关关系,旨在实现通过绕组工况快速获得POD模态系数,从而跳过对降阶模型的复杂非线性计算,进而高效重构绕组温度场。相关算例表明,该方法具有较好的计算精度和效率,在50组测试工况下,与全阶计算相比,误差不超过2.5 K,且总计算时间仅为1.45 s;最后,基于110 kV变压器绕组搭建温升试验平台,试验结果表明,降阶计算结果相较于试验结果,平均计算误差不超过2 K,且单步计算时间仅为0.03 s,相较于同等规模的全阶计算,计算效率有较大幅度地提升。 展开更多
关键词 油浸式电力变压器 绕组稳态温度 本征正交分解 包含线性多项式的径向基函数响应面 降阶模型
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基于LSTM-POD的汽车湍流尾迹的高时间分辨速度场重构
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作者 杨志刚 李俣静 +2 位作者 夏超 王梦佳 余磊 《汽车工程》 EI CSCD 北大核心 2024年第7期1302-1313,共12页
本文针对方背Ahmed汽车标模的湍流尾迹,建立基于长短时记忆法(long short-term memory,LSTM)和本征正交分解(proper orthogonal decomposition, POD)相结合的深度学习模型LSTM-POD。通过建立非时间分辨平面速度场POD模态系数和若干离散... 本文针对方背Ahmed汽车标模的湍流尾迹,建立基于长短时记忆法(long short-term memory,LSTM)和本征正交分解(proper orthogonal decomposition, POD)相结合的深度学习模型LSTM-POD。通过建立非时间分辨平面速度场POD模态系数和若干离散点的时间分辨速度信号的映射关系,实现了方背Ahmed汽车标模湍流尾迹流场的高时间分辨率重构,并对比了不同时间步长配置,即单时间步长(LSTM-Sin)和多时间步长(LSTM-Mul)对重构效果的影响。研究表明:LSTM-POD模型在时间序列重构中具有较强的学习和泛化能力。另外,LSTM-Mul考虑到了时间上的连续性和相关性,相较于LSTM-Sin,其重构出的低阶模态系数和速度场与POD的重构结果更吻合。本研究提出的深度学习模型可以缓解通过实验及高精度数值模拟获取高时间分辨率流场数据资源消耗大、计算效率低等问题。 展开更多
关键词 汽车湍流尾迹 深度学习 流场重构 本征正交分解 长短时记忆法
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包含快照选择策略的POD-QDEIM油浸式变压器绕组瞬态温升降阶算法研究及其实验验证 被引量:1
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作者 刘刚 胡万君 +4 位作者 郝世缘 姜雄伟 高成龙 刘云鹏 王文浩 《中国电机工程学报》 EI CSCD 北大核心 2024年第12期4998-5010,I0033,共14页
为了提高采用有限元方法对油浸式电力变压器绕组瞬态温升进行仿真的计算速度,该文提出一种包含快照选择策略的本征正交分解(proper orthogonal decomposition,POD)-基于列主元QR分解的离散经验插值(QR factorization-discrete empirical... 为了提高采用有限元方法对油浸式电力变压器绕组瞬态温升进行仿真的计算速度,该文提出一种包含快照选择策略的本征正交分解(proper orthogonal decomposition,POD)-基于列主元QR分解的离散经验插值(QR factorization-discrete empirical interpolation method,Q-DEIM)(POD-QDEIM)算法。首先,文章基于最小二乘有限元法与迎风有限元法推导绕组流热耦合计算方程;其次,通过引入POD方法,降低有限元方程阶数提高求解效率;同时提出POD自适应快照选择策略,在保证降阶模型精度的前提下,减小快照矩阵规模;随后,为了改善POD方法求解非线性问题时效率不高的劣势,文章结合基于Q-DEIM方法,通过插值的方法形成方程中的非线性项,从而提高每一时步非线性项的形成效率;最后,基于110 kV油浸式电力变压器绕组基本结构,建立了八分区分匝绕组传热模型以及绕组温升试验装置对所提算法进行验证,仿真及实验结果表明POD-QDEIM降阶算法的计算精度在工程上属于可接受范围,其计算效率较全阶计算提升了近11.72倍,说明该算法在油浸式电力变压器绕组瞬态温升快速仿真领域的工程应用价值。 展开更多
关键词 绕组瞬态温升 快照选择策略 本征正交分解 离散经验插值 温升实验
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Polyphenol Oxidase, Peroxidase and PhenylalanineAmmonium Lyase Induced in Postharvest Peach Fruitsby Inoculation with Pichia membranefaciensor Rhizopus stolonifer 被引量:13
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作者 QIN Guo-zheng, TIAN Shi-ping, LIU Hai-bo and XU Yong(Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany , Chinese Academy of Sciences , Beijing 100093 , P. R. China) 《Agricultural Sciences in China》 CAS CSCD 2002年第12期1370-1375,共6页
Rhizopus rot of peach fruits could be significantly suppressed by Pichia membranefaciens. Polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonium-lyase (PAL) activities induced by inoculation with P. mem... Rhizopus rot of peach fruits could be significantly suppressed by Pichia membranefaciens. Polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonium-lyase (PAL) activities induced by inoculation with P. membrane faciens or R. stolonifer were studied in postharvest peach fruits. The activities of PPO and PAL in peaches increased significantly after being inoculated with P. membrane faciens + R. stolonifer by 24 h, the activities maintained at a high level throughout the experiment. Under the condition of infected with R. stolonifer alone, activity of PPO and PAL could also increased, but the levels were lower than those treated with P. membrane faciens+ R. stolonifer. However, fruits inoculaed with P. membrane-faciens + R. stolonifer or R. stolonifer alone did not stimulated POD activity. The results suggest that the activation of these defense enzymes is involved in the action of P. membrane faciens against R. stolonifer. 展开更多
关键词 Peach fruits Polyphenol oxidase peroxidase Phenylalanine ammonium-lyase Pichia membranefaciens Rhizopus stolonifer
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