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DHAV-1、DAstV-1、DHAV-3和APMV-1四重PCR检测方法的建立及应用
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作者 李海名 吴晓燕 +3 位作者 康华裕 王旭 王一涵 张彦龙 《黑龙江畜牧兽医》 北大核心 2026年第2期94-99,共6页
为了建立一种能同时检测鸭甲肝病毒1型(DHAV-1)、鸭星状病毒1型(DAstV-1)、鸭甲肝病毒3型(DHAV-3)和禽副黏病毒1型(APMV-1)的方法,试验根据GenBank中公布的DHAV-13A基因、DAstV-11a基因、DHAV-33a3b基因和APMV-1 F基因序列分别设计4对... 为了建立一种能同时检测鸭甲肝病毒1型(DHAV-1)、鸭星状病毒1型(DAstV-1)、鸭甲肝病毒3型(DHAV-3)和禽副黏病毒1型(APMV-1)的方法,试验根据GenBank中公布的DHAV-13A基因、DAstV-11a基因、DHAV-33a3b基因和APMV-1 F基因序列分别设计4对特异性引物,通过优化反应条件及特异性、敏感性和重复性试验建立了四重PCR检测方法,并采用该方法对96份疑似病毒感染的鸭病料样本进行检测。结果表明:DHAV-1、DHAV-3、DAstV-1和APMV-1四重RT-PCR检测方法的最优退火温度和引物浓度分别为56℃、0.8μmol/L。该方法能同时扩增出大小为195 bp(DHAV-13A基因)、289 bp(DAstV-11a基因)、462 bp(DHAV-33a3b基因)、726 bp(APMV-1基因)的特异性片段,而与鸭瘟病毒(DPV)、鸭坦布苏病毒(DTMUV)、鸭圆环病毒(DuCV)和鸭甲肝病毒2型(DHAV-2)无交叉反应;对DHAV-1、DAstV-1、DHAV-3和APMV-1的最低检测限分别为1.111×10~4 copies/μL、3.078×10~2 copies/μL、4.938×10~3 copies/μL、3.456×10~2 copies/μL;批间重复试验和批内重复试验的3个平行样本的结果均一致。采用该方法对96份临床样本的检测结果与参考方法的符合率为100%。说明本研究建立的针对DHAV-1、DHAV-3、DAstV-1和APMV-1四重PCR检测方法特异性强、敏感性较高、重复性好,在临床样本检测中展现出良好的应用效果。 展开更多
关键词 鸭甲肝病毒 鸭星状病毒 禽副黏病毒1 混合感染 多重PCR检测方法 检测方法建立
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混合相α/β-Ni_(1-x)C_(r)(OH)_(2)的制备及电化学性能研究
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作者 赵娜娜 张鑫尧 +3 位作者 王海 周兴辉 沈俊诚 关明云 《功能材料》 北大核心 2026年第1期163-169,共7页
采用水热法制备了片状结构的混合相α/β-Ni_(1-x)C_(r)(OH)_(2)。XRD表征显示通过调控Cr^(3+)的掺杂量,β相、α相和混合相α/β-Ni_(1-x)C_(r)(OH)_(2)很容易被调控合成。CV和EIS测定显示,混合相α/β-Ni_(1-x)C_(r)(OH)_(2)(x=0.03~0... 采用水热法制备了片状结构的混合相α/β-Ni_(1-x)C_(r)(OH)_(2)。XRD表征显示通过调控Cr^(3+)的掺杂量,β相、α相和混合相α/β-Ni_(1-x)C_(r)(OH)_(2)很容易被调控合成。CV和EIS测定显示,混合相α/β-Ni_(1-x)C_(r)(OH)_(2)(x=0.03~0.10)的电化学性能优于β相和α相。当Cr掺杂量为3%时,产物的电化学性能最佳。将Cr含量3%的α/β-Ni_(0.97)Cr_(0.03)(OH)_(2)作为正极组装NiZn电池,电化学性能测试结果表明,其最高能量密度为250.49 Wh/kg,1500次循环后,仍能保持246.26 Wh/kg的能量密度,容量保持率达98.3%,库伦效率在98%以上,展现出优异的循环稳定性。 展开更多
关键词 锌镍电池 电化学性能 混合相α/β-Ni_(1-x)C_(r)(OH)_(2) 水热法 纳米材料
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LALR(1)语法分析器的自动生成 被引量:2
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作者 肖俊超 张家晨 《计算机应用》 CSCD 北大核心 2003年第4期65-68,共4页
文章简单介绍了语法分析器自动生成的原理和技术 ,根据语法分析器的生成过程 ,介绍了实用的语法分析器的自动生成器各个部件及其实现的详细过程。
关键词 lalr(1)语法分析器 自动生成 LR方法 lalr(1)方法 Shift表 Reduce表 C语言 程序设计 语法分析程序 文件输入方法
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VPGE:一个LALR(1)分析器的可视化生成和断点调试系统 被引量:3
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作者 李虎 金茂忠 许福 《计算机研究与发展》 EI CSCD 北大核心 2007年第5期823-828,共6页
LALR(1)分析程序生成系统在编译器构造领域以外被许多普通软件开发者学习和使用.为帮助用户理解LALR(1)分析器方法,编写出正确、完整、无语法分析冲突的文法规范,严格定义了使用LALR(1)分析器生成器时用户可能遇到的几类文法问题,描述... LALR(1)分析程序生成系统在编译器构造领域以外被许多普通软件开发者学习和使用.为帮助用户理解LALR(1)分析器方法,编写出正确、完整、无语法分析冲突的文法规范,严格定义了使用LALR(1)分析器生成器时用户可能遇到的几类文法问题,描述一个为帮助用户解决这些问题而开发的LALR(1)分析器可视化和断点调试系统VPGE.VPGE以多种视图显示LALR(1)分析器的数据结构,包括状态栈、符号栈、输入符号串、分析树和底层的自动机,支持LR分析动作的单步执行和断点调试.性能实验结果表明,VPGE比GNU的Bison有更快的分析器生成速度,从而提供了一个LALR(1)文法及分析器的快速交互式调试环境. 展开更多
关键词 lalr(1) 分析器生成 YACC BISON 文法调试 软件可视化 断点
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LALR(1)解析器的再工程:YACC和CUP剖析 被引量:1
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作者 张昱 张磊 《计算机工程》 EI CAS CSCD 北大核心 2005年第15期50-52,共3页
现有的前端分析多数是通过编写相应的可能含有二义的LALR(1)文法规范,利用YACC或其变种自动生成的。在这些解析器的Java再工程中,可以用CUP去替代YACC,这样再工程的焦点转移到对文法规范的变换。由于YACC及CUP在二义的解决、解析器的构... 现有的前端分析多数是通过编写相应的可能含有二义的LALR(1)文法规范,利用YACC或其变种自动生成的。在这些解析器的Java再工程中,可以用CUP去替代YACC,这样再工程的焦点转移到对文法规范的变换。由于YACC及CUP在二义的解决、解析器的构造等有细微的差别,因此对复杂的文法规范的变换并不是一件容易的事。该文通过剖析YACC和CUP,指出了它们的不同之处,并总结出有二义的YACC文法到CUP文法变换的基本原则和几个变换法则。 展开更多
关键词 lalr(1) 解析器 YACC CUP 二义性 冲突
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LALR(1)分析器快速生成 被引量:1
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作者 李虎 杨晓津 刘超 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2008年第1期117-121,共5页
根据LR(0)自动机的构造理论及Deremer和Pennello的LALR(1)向前看符号集计算公式,提出求解公式中的lookback关系和includes关系的高效算法.研究过程表明,LR(0)项目集闭包计算和项目集的查找是LR(0)分析器构造过程中的主要性能瓶颈.对这... 根据LR(0)自动机的构造理论及Deremer和Pennello的LALR(1)向前看符号集计算公式,提出求解公式中的lookback关系和includes关系的高效算法.研究过程表明,LR(0)项目集闭包计算和项目集的查找是LR(0)分析器构造过程中的主要性能瓶颈.对这两个计算过程给出了高效的数据结构和算法设计,实现了LALR(1)分析器的快速生成.系统实现及实验数据表明,LALR(1)分析器的生成速度超过了自由软件基金会的LALR(1)分析器生成器B ison. 展开更多
关键词 语法分析器生成 自底向上分析 向前看符号集
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Comparative Analysis of Improving Effects of 12 Maize Populations with Improved S_1 Selection Method
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作者 孙峰成 冯勇 +6 位作者 付增娟 苏二虎 张来厚 赵瑞霞 刘志雄 石海波 李美娜 《Agricultural Science & Technology》 CAS 2014年第10期1687-1692,1713,共7页
ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of... ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of grains per row and 100-grain weight were the three important component traits of maize yield. The highest genetic increment was found in Mengqun 2, fol owed by Mengqun 4, Mengqun 1 and other 7 maize populations. Negative genetic increment was shown in Mengqun 3 and 3 introduced foreign maize populations. Some changes were shown in spikes, plant traits and genetic diversity of maize populations. Based on our results, we concluded that Mengqun 2, Mengqun 4, Zhongzong 7, Mengqun C and Mengqun A could be directly used for the line breeding by selfing for their higher genetic increment of yield and better improvement effects of other agricultural traits. Compared with these 5 populations, the improvement potential of other maize populations was limited for their lower genetic increment. 展开更多
关键词 lmproved S1 selection method Maize population Genetic gain Comparative analysis
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一种基于BNF范式的LALR(1)语法分析器描述语言的设计 被引量:1
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作者 李洋 胥亮 《新技术新工艺》 2015年第6期70-72,共3页
常见的LALR(1)语法分析器自动生成系统所支持的程序设计语言语法复杂,用户学习困难。以此为出发点,设计了一种基于BNF范式的LALR(1)语法分析器描述语言,分析了该语言需满足的需求,并给出了该语言的文法。该语言文法功能完备,使用简单,... 常见的LALR(1)语法分析器自动生成系统所支持的程序设计语言语法复杂,用户学习困难。以此为出发点,设计了一种基于BNF范式的LALR(1)语法分析器描述语言,分析了该语言需满足的需求,并给出了该语言的文法。该语言文法功能完备,使用简单,易于学习,为构造LALR(1)语法分析器的自动化实现提供了一种思路。 展开更多
关键词 编译器 YACC BNF lalr(1)
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半夏新品种“息半夏1号”的选育
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作者 腊贵晓 史贵霞 +3 位作者 赵玉龙 杨振 代丹丹 杨铁钢 《北方园艺》 北大核心 2025年第13期156-160,共5页
“息半夏1号”从河南息县半夏半野生群体中经系统选育法筛选出的息半夏优良品系,2024年6月通过河南省中药材品种专业鉴定委员会鉴定。该品种于2018—2020年在多点区域试验中,块茎平均产量为713.58 kg·hm^(-2),比对照息县当地农家... “息半夏1号”从河南息县半夏半野生群体中经系统选育法筛选出的息半夏优良品系,2024年6月通过河南省中药材品种专业鉴定委员会鉴定。该品种于2018—2020年在多点区域试验中,块茎平均产量为713.58 kg·hm^(-2),比对照息县当地农家种增产29.1%;在2021—2023年的生产示范试验中,块茎平均产量为722.2 kg·hm^(-2),比对照息县当地农家种增产25.3%。其中所含主要有效成分均符合《中华人民共和国药典(一部2020年版)》标准要求,且β-谷甾醇含量显著高于当地农家种。适宜河南省信阳市息县及生态类型相似的地区种植。 展开更多
关键词 半夏 品种 系统选育 “息半夏1号”
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摩腹法对IBS-D模型大鼠肠黏膜紧密连接功能及ZO-1的影响研究
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作者 李华南 崔刘魁 +5 位作者 卢燚 张玮 包安 陈英英 刘书芹 王金贵 《辽宁中医杂志》 北大核心 2025年第2期173-176,共4页
目的验证摩腹法干预腹泻型肠易激综合征(irritable bowel syndrome with predominant diarrhea,IBS-D)模型大鼠效果,阐明腹部推拿对IBS-D模型大鼠肠黏膜紧密连接的影响。方法采用母婴分离法+慢性应激法制备IBS-D大鼠模型。将30只SD雄性... 目的验证摩腹法干预腹泻型肠易激综合征(irritable bowel syndrome with predominant diarrhea,IBS-D)模型大鼠效果,阐明腹部推拿对IBS-D模型大鼠肠黏膜紧密连接的影响。方法采用母婴分离法+慢性应激法制备IBS-D大鼠模型。将30只SD雄性大鼠,随机分为正常组、模型组、摩腹组,每组10只。采用粪便含水量测试、粪便性状评分评价干预效果。利用透射电镜观察结肠黏膜组织状态。应用Western-blot法检测大鼠结肠组织中ZO-1蛋白表达。结果(1)与模型组比较,摩腹组粪便含水率、粪便性状评分明显下降(P<0.05),接近正常组(P>0.05)。(2)透射电镜下观察,模型组肠上皮细胞胞浆内有空泡,线粒体大量减少,分布不均,少见完整细胞核,细胞形态大小不一,细胞间间隙变大,紧密连接结构遭到破坏,肠上皮微绒毛缺如;摩腹干预后,肠上皮细胞质空泡减少得到恢复,线粒体增多,结构清晰,细胞核结构可见,细胞间间隙变窄,紧密连接结构部分恢复,肠上皮微绒毛分布不均部分短缺。(3)与正常组相比,模型组ZO-1蛋白表达明显下调(P<0.05),当予以摩腹干预后,ZO-1蛋白表达明显上调(P<0.05)。结论摩腹法能够通过上调ZO-1蛋白表达对大鼠肠上皮紧密连接产生影响,进而对肠上皮紧密连接和肠上皮通透性产生影响,进而改善IBS-D大鼠肠道症状。 展开更多
关键词 IBS-D 摩腹法 肠上皮通透性 紧密连接 ZO-1蛋白
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A new approach for selecting best development face ventilation mode based on G1-coefficient of variation method 被引量:16
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作者 ZHOU Zhi-yong Mehmet KIZIL +1 位作者 CHEN Zhong-wei CHEN Jian-hong 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第10期2462-2471,共10页
The current popular methods for decision making and project optimisation in mine ventilation contain a number of deficiencies as they are solely based on either subjective knowledge or objective information.This paper... The current popular methods for decision making and project optimisation in mine ventilation contain a number of deficiencies as they are solely based on either subjective knowledge or objective information.This paper presents a new approach to rank the alternatives by G1-coefficient of variation method.The focus of this approach is the use of the combination weighing,which is able to compensate for the deficiencies in the method of evaluation index single weighing.In the case study,an appropriate evaluation index system was established to determine the evaluation value of each ventilation mode.Then the proposed approach was used to select the best development face ventilation mode.The result shows that the proposed approach is able to rank the alternative development face ventilation mode reasonably,the combination weighing method had the advantages of both subjective and objective weighing methods in that it took into consideration of both the experience and wisdom of experts,and the new changes in objective conditions.This approach provides a more reasonable and reliable procedure to analyse and evaluate different ventilation modes. 展开更多
关键词 development face ventilation G1 method coefficient of variation method comprehensive evaluation OPTIMIZATION
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Performances of conventional fusion methods evaluated for inland water body observation using GF-1 image 被引量:3
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作者 Yong Du Xiaoyu Zhang +1 位作者 Zhihua Mao Jianyu Chen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第1期172-179,共8页
Satellite remote sensing of inland water body requires a high spatial resolution and a multiband narrow spectral resolution, which makes the fusion between panchromatic(PAN) and multi-spectral(MS) images particularly ... Satellite remote sensing of inland water body requires a high spatial resolution and a multiband narrow spectral resolution, which makes the fusion between panchromatic(PAN) and multi-spectral(MS) images particularly important. Taking the Daquekou section of the Qiantang River as an observation target, four conventional fusion methods widely accepted in satellite image processing, including pan sharpening(PS), principal component analysis(PCA), Gram-Schmidt(GS), and wavelet fusion(WF), are utilized to fuse MS and PAN images of GF-1.The results of subjective and objective evaluation methods application indicate that GS performs the best,followed by the PCA, the WF and the PS in the order of descending. The existence of a large area of the water body is a dominant factor impacting the fusion performance. Meanwhile, the ability of retaining spatial and spectral informations is an important factor affecting the fusion performance of different fusion methods. The fundamental difference of reflectivity information acquisition between water and land is the reason for the failure of conventional fusion methods for land observation such as the PS to be used in the presence of the large water body. It is suggested that the adoption of the conventional fusion methods in the observing water body as the main target should be taken with caution. The performances of the fusion methods need re-assessment when the large-scale water body is present in the remote sensing image or when the research aims for the water body observation. 展开更多
关键词 GF-1 satellite IMAGE FUSION methods FUSION evaluation INLAND water body
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Nano/Micro HKUST-1 Fabricated by Coordination Modulation Method at Room Temperature 被引量:8
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作者 NA Li-yan HUA Rui-nian +1 位作者 NING Gui-ling OU Xiao-xia 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第4期555-558,共4页
A simple and fast route for the synthesis of metal-organic framework(MOF) particles was presented.Cu 3(BTC) 2(HKUST-1,BTC=1,3,5-benzenetricarboxylate),one of the most well-known MOFs,was synthesized at room temp... A simple and fast route for the synthesis of metal-organic framework(MOF) particles was presented.Cu 3(BTC) 2(HKUST-1,BTC=1,3,5-benzenetricarboxylate),one of the most well-known MOFs,was synthesized at room temperature via coordination modulation method.By adding different modulators(monocarboxylic acids) into the reaction system,the morphologies of HKUST-1 crystals were tuned from nano spheres to micro octahedrons at room temperature without any complex equipment.X-Ray diffractions and gas sorption measurements revealed highly crystalline particles with large Brunauer-Emmett-Teller(BET) surface areas(1116―1273 m^ 2 /g) and total pore volumes(0.62―0.73 cm^ 3 /g).The significantly small particle sizes and high capacity of gas sorption are considered advantageous for envisaged application in practical industrial process. 展开更多
关键词 Cu3(BTC)2(HKUST-1 Metal-organic framework Coordination modulation method
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Preparation of Perovskite-Type Oxides La_(1-x)Sr_xFe_(1-y)Co_yO_3 Using EDTA Sol-Gel Method 被引量:3
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作者 于洁 马文会 王华 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第6期766-770,共5页
Two series of perovskite-type oxides with composition (La_(1-x))Sr_xFeO_3(x≤0.8)and La_(1-x)Sr_xFe_(1-y)Co_yO_3(x=0.2; y=0.2, 0.4)powder productions were synthesized by EDTA complexing sol-gel method. The products we... Two series of perovskite-type oxides with composition (La_(1-x))Sr_xFeO_3(x≤0.8)and La_(1-x)Sr_xFe_(1-y)Co_yO_3(x=0.2; y=0.2, 0.4)powder productions were synthesized by EDTA complexing sol-gel method. The products were characterized by XRD, TEM, SEM, BET method(N_2 adsorption)and laser granularity analysis for different synthesis conditions to obtain the optimum conditions for the preparation process. Single-phased, uniform perovskite-type oxides with small particle size were obtained by EDTA sol-gel process with high stability and repeatability, and the process temperature is much lower than that of solid state reaction method. 展开更多
关键词 perovskite La_(1-x)Sr_xFe_(1-y)Co_yO_3 EDTA sol-gel method preparation process rare earths
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Error estimates of H^1-Galerkin mixed finite element method for Schrdinger equation 被引量:28
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作者 LIU Yang LI Hong WANG Jin-feng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第1期83-89,共7页
An H^1-Galerkin mixed finite element method is discussed for a class of second order SchrSdinger equation. Optimal error estimates of semidiscrete schemes are derived for problems in one space dimension. At the same t... An H^1-Galerkin mixed finite element method is discussed for a class of second order SchrSdinger equation. Optimal error estimates of semidiscrete schemes are derived for problems in one space dimension. At the same time, optimal error estimates are derived for fully discrete schemes. And it is showed that the H1-Galerkin mixed finite element approximations have the same rate of convergence as in the classical mixed finite element methods without requiring the LBB consistency condition. 展开更多
关键词 H1-Galerkin mixed finite element method Schrdinger equation LBB condition optimal error estimates
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The (G'/G, 1/G)-expansion method and its application to travelling wave solutions of the Zakharov equations 被引量:14
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作者 LI Ling-xiao LI Er-qiang WANG Ming-liang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2010年第4期454-462,共9页
The (G'/G, 1/G)-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the (G'/G)-expansion method proposed recently, is present... The (G'/G, 1/G)-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the (G'/G)-expansion method proposed recently, is presented. By using this method abundant travelling wave so- lutions with arbitrary parameters of the Zakharov equations are successfully obtained. When the parameters are replaced by special values, the well-known solitary wave solutions of the equations are rediscovered from the travelling waves. 展开更多
关键词 The (G /G 1/G)-expansion method travelling wave solutions homogeneous balance solitary wave solutions Zakharov equations.
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GF-3与Sentinel-1影像对山区小水体提取能力评估
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作者 陆建忠 张盛 +3 位作者 刘新波 翟少军 曹辉 鲍正风 《人民长江》 北大核心 2025年第6期56-63,共8页
为解决山区小水体监测中的实时跟踪难题,提高监测精度,评估GF-3和Sentinel-1雷达卫星影像的水体提取能力。在香溪河流域内选取多个水库,采用局部阈值法对两种雷达影像进行水体提取,并将结果与Sentinel-2 MSI影像使用归一化差分水体指数(... 为解决山区小水体监测中的实时跟踪难题,提高监测精度,评估GF-3和Sentinel-1雷达卫星影像的水体提取能力。在香溪河流域内选取多个水库,采用局部阈值法对两种雷达影像进行水体提取,并将结果与Sentinel-2 MSI影像使用归一化差分水体指数(NDWI)的提取结果进行比较,再通过精度指标进行定量分析。结果表明:GF-3在捕捉水体变化方面具有优势,召回率最高可达0.952,但在复杂地形下容易受到噪声影响而产生错误提取;相较之下,Sentinel-1展现出更好的精确度和一致性,精准率最高达到0.913,交并比(IoU)最高为0.830;在淹没频率分析中,GF-3对比Sentinel-1展现了更丰富的时空变化特征。研究成果可为云雨天气条件下水库群水体提取和水资源管理提供科学依据。 展开更多
关键词 水体提取 卫星遥感 GF-3 Sentinel-1 淹没频率 局部阈值法 香溪河流域
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新的(2+1)维Boussinesq方程的孤立子解
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作者 郭学军 曹玉雷 《山东大学学报(理学版)》 北大核心 2025年第5期33-39,共7页
研究(2+1)维的Boussinesq方程,该系统是Boussinesq方程的一个多维推广版本。利用Hirota的双线性方法构造(2+1)维Boussinesq方程的孤立子解,并分析孤立子解的局部特征,给出了孤立子解的动力学行为。此外,在特殊参数限制下得到了共振的孤... 研究(2+1)维的Boussinesq方程,该系统是Boussinesq方程的一个多维推广版本。利用Hirota的双线性方法构造(2+1)维Boussinesq方程的孤立子解,并分析孤立子解的局部特征,给出了孤立子解的动力学行为。此外,在特殊参数限制下得到了共振的孤立子解。由于共振碰撞,孤立子解呈现“V”型,不再是传统的交叉型。更高阶的共振孤立子解的动力学行为更加复杂多样,由基本的共振孤立子叠加而成。 展开更多
关键词 (2+1)-维Boussinesq方程 双线性方法 孤立子解 动力学
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Sea surface wind speed retrieval from Sentinel-1 HH polarization data using conventional and neural network methods 被引量:4
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作者 Tingting Qin Tong Jia +1 位作者 Qian Feng Xiaoming Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第1期13-21,共9页
Conventional retrieval and neural network methods are used simultaneously to retrieve sea surface wind speed(SSWS)from HH-polarized Sentinel-1(S1)SAR images.The Polarization Ratio(PR)models combined with the CMOD5.N G... Conventional retrieval and neural network methods are used simultaneously to retrieve sea surface wind speed(SSWS)from HH-polarized Sentinel-1(S1)SAR images.The Polarization Ratio(PR)models combined with the CMOD5.N Geophysical Model Function(GMF)is used for SSWS retrieval from the HH-polarized SAR data.We compared different PR models developed based on previous C-band SAR data in HH-polarization for their applications to the S1 SAR data.The recently proposed CMODH,i.e.,retrieving SSWS directly from the HHpolarized S1 data is also validated.The results indicate that the CMODH model performs better than results achieved using the PR models.We proposed a neural network method based on the backward propagation(BP)neural network to retrieve SSWS from the S1 HH-polarized data.The SSWS retrieved using the BP neural network model agrees better with the buoy measurements and ASCAT dataset than the results achieved using the conventional methods.Compared to the buoy measurements,the bias,root mean square error(RMSE)and scatter index(SI)of wind speed retrieved by the BP neural network model are 0.10 m/s,1.38 m/s and 19.85%,respectively,while compared to the ASCAT dataset the three parameters of training set are–0.01 m/s,1.33 m/s and 15.10%,respectively.It is suggested that the BP neural network model has a potential application in retrieving SSWS from Sentinel-1 images acquired at HH-polarization. 展开更多
关键词 Sentinel-1 HH-polarization sea surface wind speed retrieval methods
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Synthesis of LiEu_(1-x)Bix(MoO_4)_2 red phosphors by sol-gel method and their luminescent properties 被引量:7
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作者 雷惊雷 于艳 +3 位作者 李凌杰 程士宝 李冠宇 李念兵 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第4期330-334,共5页
The Bi3+ doped molybdate-based red-emitting phosphors, LiEu1-xBix(MoO4)2, were successfully synthesized with a sol-gel method. The prepared LiEu1-xBix(MoO4)2 phosphors exhibited pure and intense red emission at 6... The Bi3+ doped molybdate-based red-emitting phosphors, LiEu1-xBix(MoO4)2, were successfully synthesized with a sol-gel method. The prepared LiEu1-xBix(MoO4)2 phosphors exhibited pure and intense red emission at 613 nm under the excitation of near-UV 394 nm. It was discussed in detail that the influence of the synthesis conditions such as the doping concentration of Bi3, the dose of citric acid, pH of the precursor solution and the sintering temperature on the emission intensity of the phosphors. According to the results, the optimal condition was obtained: the doping concentration of Bi3+ was 15 mol.%, molar ratio of citric acid to metal ions was 1.5:1, pH of the precursor solution was 1.0 and the sintering temperature was 800 ℃. The X-ray diffraction (XRD) patterns of the LiEuo.85Bi0.15(MoO4)2 phosphor prepared under the optimal condition indicated that the phosphor was single phase with tetragonal scheelite structure. The Commission Intemationale de I'E- clairage (CIE) chromaticity coordinates of LiEuo.85Bio.15(MoO4)2 were (x=0.655, y=0.345), which were closer to the national television stan- dard committee (NTSC) standard values (x=0.670, y=0.330) than that of a commercial red phosphor of Y202S:Eu3+(x=0.630, y=0.350). This LiEuo.85Bi0As(MoO4)2 red phosphor is a promising candidate for the fabrication of white light-emitting diode (W-LED) with near-UV chips. 展开更多
关键词 red phosphor sol-gel method LiEU1-xBix(MoO4)2 rare earths
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