期刊文献+
共找到304篇文章
< 1 2 16 >
每页显示 20 50 100
Phase states of moisture content in different maize kernel types 被引量:1
1
作者 Na Li Tongyu Xu Nan Hao 《International Journal of Agricultural and Biological Engineering》 SCIE CAS 2023年第1期250-259,共10页
Accurate determination of the moisture content in maize kernels conduces to screen maize germplasm materials with efficient dehydration.Low-field nuclear magnetic resonance(LF-NMR)single-kernel non-destructive testing... Accurate determination of the moisture content in maize kernels conduces to screen maize germplasm materials with efficient dehydration.Low-field nuclear magnetic resonance(LF-NMR)single-kernel non-destructive testing technology was used to determine the moisture content at different phase states in the kernels for selected types of maize.The NMR T 2 relaxation inversion spectrum was monitored in maize kernels to determine the variation in the moisture content in different phase states with time.The total water and free water peaked at the filling stage of the maize kernels and then declined to a minimum at physiological maturity.The semi-bound water generally increased to a long-lasting peak in the dough stage and then declined.The bound water increased from kernel formation to maturity and then remained stable.The contents of total water,free water,semi-bound water,and bound water had significant differences among kernel types but not among varieties of the same type.The contents of semi-bound water and free water were linearly correlated with the dehydration rates of the kernels.The results of this study can provide a means for creating new germplasm materials. 展开更多
关键词 maize(Zea mays L.) LF-NMR moisture phase state kernel type dehydration rate
原文传递
ON RIESZ TYPE KERNELS OVER LOCAL FIELDS 被引量:1
2
作者 Zheng Shijun(Nanjing University, China) 《Analysis in Theory and Applications》 1995年第4期24-34,共11页
Based on a representation lemma. Riesz type kernels on the local field K and on the integer ring O in K are coitstructed. Furthermore, we discuss approximation theorems for the Lipschitz class Lip(L ;α) ana the Lp bo... Based on a representation lemma. Riesz type kernels on the local field K and on the integer ring O in K are coitstructed. Furthermore, we discuss approximation theorems for the Lipschitz class Lip(L ;α) ana the Lp boundedness of such operators motivated by the open problem: Does σηfa,s→f for f ∈L1(O) (see M. H. Taible-son [6] and [5])? 展开更多
关键词 ON RIESZ type kernelS OVER LOCAL FIELDS LIM
在线阅读 下载PDF
HEAT KERNELS AND HARDY'S UNCERTAINTY PRINCIPLE ON H-TYPE GROUPS
3
作者 朱赋鎏 杨乔华 《Acta Mathematica Scientia》 SCIE CSCD 2008年第1期171-178,共8页
This article obtains an explicit expression of the heat kernels on H-type groups and then follow the estimate of heat kernels to deduce the Hardy's uncertainty principle on the nilpotent Lie groups.
关键词 H-type groups heat kernel Hardy's uncertainty principle
在线阅读 下载PDF
A Class of Singular Integral Equation of Convolution Type with CSC(τ- θ) Kernel
4
作者 LI Ping-run 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第4期620-626,共7页
In this paper, we propose and discuss a class of singular integral equation of convolution type with csc(τ- θ) kernel in class L2[-π, π]. Using discrete Fourier transform and the lemma, this kind of equations is t... In this paper, we propose and discuss a class of singular integral equation of convolution type with csc(τ- θ) kernel in class L2[-π, π]. Using discrete Fourier transform and the lemma, this kind of equations is transformed to discrete system of equations, and then we obtain the solvable conditions and the explicit solutions in class L2[-π, π]. 展开更多
关键词 singular integral equation convolution type csc(τ-θ) kernel
在线阅读 下载PDF
Hilbert-type integral inequality with the homogeneous kernel of 0-degree
5
作者 杨必成 《Journal of Shanghai University(English Edition)》 CAS 2010年第6期391-395,共5页
Through using weight function, we give a new Hilbert-type integral inequality with two independent parameters and two pair of conjugate exponents, which is a best extension of a Hilbert-type integral inequality with t... Through using weight function, we give a new Hilbert-type integral inequality with two independent parameters and two pair of conjugate exponents, which is a best extension of a Hilbert-type integral inequality with the homogeneous kernel of 0-degree. The equivalent form, the reverses and some particular results are considered. 展开更多
关键词 Hilbert-type integral inequality weight function kernel conjugate exponent
在线阅读 下载PDF
Analysis of Variations in White-Belly and White-Core Rice Kernels Within a Panicle and the Effect of Panicle Type
6
作者 ZHANG Xin-cheng Md A.Alim +5 位作者 LIN Zhao-miao LIU Zheng-hui LI Gang-hua WANG Qiang-sheng WANG Shao-hua DING Yan-feng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第8期1672-1679,共8页
This study aims to investigate the variation in occurrence of white-belly rice kernel(WBRK) and white-core rice kernel(WCRK) among different positions within a panicle. Twenty-four M4 mutants involved in four pani... This study aims to investigate the variation in occurrence of white-belly rice kernel(WBRK) and white-core rice kernel(WCRK) among different positions within a panicle. Twenty-four M4 mutants involved in four panicle types, namely the compact, intermediate, loose, and chicken foot panicle were used. They derived from a japonica rice cultivar Wuyujing 3. Considerable differences in morphological characters existed among the four types of panicle, especially in panicle length, the secondary branch number and ratio of grain number to total branch length. Marked differences were found in WBRK and WCRK among different positions within a panicle for all types of panicle. In general, grains located on the primary rachis and top rachis branches had higher WBRK and WCRK percentage than those on the secondary rachis and bottom rachis branches. WCRK exhibited larger variation among grain positions than WBRK did. Moreover, there was a significant difference in WCRK/WBRK among grain positions within a panicle, with primary rachis and top rachis branches having higher values than the secondary and bottom rachis. In addition, panicle type showed no significant effect on the pattern of WBRK and WCRK occurrence within a panicle. The results indicated the difference in mechanism of WBRK and WCRK formation in grain position within a panicle, and are valuable for breeding and agronomic practices aimed at lowering chalky grain rate. 展开更多
关键词 panicle type white-belly rice kernel white-core rice kernel grain position mutants japonica rice
在线阅读 下载PDF
Herz-type Hardy Space Estimates for Multilinear Operators with Dini Kernels
7
作者 刘明菊 陆善镇 《Northeastern Mathematical Journal》 CSCD 2004年第3期275-283,共9页
In this paper, the authors study the multilinear operators with Dini Kernel and obtain their boundedness from Herz spaces to Herz-type Hardy spaces. Moreover, the authors also consider the corresponding fractional ope... In this paper, the authors study the multilinear operators with Dini Kernel and obtain their boundedness from Herz spaces to Herz-type Hardy spaces. Moreover, the authors also consider the corresponding fractional operators. 展开更多
关键词 multilinear operator Herz-type Hardy space Herz space Dini kernel
在线阅读 下载PDF
Toeplitz Type Operator Associated to Singular Integral Operator with Variable Kernel on Weighted Morrey Spaces 被引量:1
8
作者 Yuexiang He Yueshan Wang 《Analysis in Theory and Applications》 CSCD 2016年第1期90-102,共13页
Suppose T^k,l and T^k,2 are singular integrals with variable kernels and mixed homogeneity or ±I (the identity operator). Denote the Toeplitz type operator by T^b=k=1∑^QT^k,1M^bT^k,2 where M^bf= bf. In this pa... Suppose T^k,l and T^k,2 are singular integrals with variable kernels and mixed homogeneity or ±I (the identity operator). Denote the Toeplitz type operator by T^b=k=1∑^QT^k,1M^bT^k,2 where M^bf= bf. In this paper, the boundedness of Tb on weighted Morrey space are obtained when b belongs to the weighted Lipschitz function space and weighted BMO function space, respectively. 展开更多
关键词 Toeplitz type operator singular integral operator variable Calderon-Zygmund kernel weighted BMO function weighted Lipschitz function weighted Morrey space.
在线阅读 下载PDF
青贮玉米籽粒破碎技术研究进展
9
作者 王其欢 姜伟 +4 位作者 李洪迁 邸志峰 周进 张华 孙志民 《农业装备与车辆工程》 2026年第2期14-19,28,共7页
青贮玉米作为优质饲料,是支撑我国畜牧产业高质量发展的重要物质基础。为应对畜牧产业对青贮饲料的巨大需求,加快青贮玉米收获机研发与产业化应用至关重要,其中籽粒破碎技术装备是影响收获质量的核心环节。系统梳理了国内外青贮玉米籽... 青贮玉米作为优质饲料,是支撑我国畜牧产业高质量发展的重要物质基础。为应对畜牧产业对青贮饲料的巨大需求,加快青贮玉米收获机研发与产业化应用至关重要,其中籽粒破碎技术装备是影响收获质量的核心环节。系统梳理了国内外青贮玉米籽粒破碎技术的研究进展,首先从工作原理出发,对差速辊式、齿盘式及组合式等主流破碎装置的结构特点与应用现状进行了总结与对比;进而重点围绕籽粒破碎机理、关键影响因素与参数优化、智能化调控技术等方面,综述了相关研究方法与最新成果。分析表明,我国在该领域虽取得一定进展,但在破碎机理深入认知、关键部件材料工艺以及智能化闭环控制等方面仍与国际先进水平存在显著差距。基于此,总结了当前研究存在的问题,并从深化机理研究、突破先进制造工艺、构建智能作业系统等方向提出了未来展望,以期为我国青贮玉米籽粒破碎技术的自主创新与装备升级提供参考。 展开更多
关键词 青贮玉米 籽粒破碎 差速辊式 齿盘式 智能化
在线阅读 下载PDF
BOUNDEDNESS OF MARCINKIEWICZ INTEGRAL RELATED TO MULTILINEAR COMMUTATORS WITH VARIABLE KERNELS ON HARDY SPACES 被引量:1
10
作者 Xiaomei Wu 《Analysis in Theory and Applications》 2008年第2期139-148,共10页
Let b = (b1 ,b2,… ,bm),bi ∈∧βi(R^n), 1 ≤ i≤ m,βi 〉 0, m∑i=1βi = β,0 〈 β 〈 1 μΩ,b (f)(x) =(∫0^∞|Fb,t (f) (x)|^2 dt/t^3)^1/2,Fb,t(f)(x)= ∫|x-y|≤t Ω(x,x-y)/|x-y|^n-1 m∏i=1... Let b = (b1 ,b2,… ,bm),bi ∈∧βi(R^n), 1 ≤ i≤ m,βi 〉 0, m∑i=1βi = β,0 〈 β 〈 1 μΩ,b (f)(x) =(∫0^∞|Fb,t (f) (x)|^2 dt/t^3)^1/2,Fb,t(f)(x)= ∫|x-y|≤t Ω(x,x-y)/|x-y|^n-1 m∏i=1[bi(x)-bi(t)]f(y)cy.We consider the boundedness of μΩ,b on Hardy type space Hp/b(R^n) 展开更多
关键词 Marcinkiewicz integral multilinear commutators variable kernels Hardy type space
在线阅读 下载PDF
变指数Herz-type Hardy空间上的一类分数次积分及交换子
11
作者 周疆 赵欢 《河南师范大学学报(自然科学版)》 CAS 北大核心 2018年第5期13-19,共7页
设Ω∈L~∞(R^n)×L^r(S^(n-1))(r≥1)是零次齐次函数,且b∈Lip_γ(R^n).利用Herz-type Hardy空间的原子分解理论,研究了带变量核的分数次积分算子,当核函数满足一定条件时,证明了这类算子T_(Ω,μ)及其交换子[b^m,T_(Ω,μ)]在变指... 设Ω∈L~∞(R^n)×L^r(S^(n-1))(r≥1)是零次齐次函数,且b∈Lip_γ(R^n).利用Herz-type Hardy空间的原子分解理论,研究了带变量核的分数次积分算子,当核函数满足一定条件时,证明了这类算子T_(Ω,μ)及其交换子[b^m,T_(Ω,μ)]在变指数Herz-type Hardy空间上的有界性. 展开更多
关键词 变量核 分数次积分算子 高阶交换子 变指数Herz-type HARDY空间
在线阅读 下载PDF
带粗糙核的分数次积分算子的交换子在Morrey-type空间上的加权有界
12
作者 黄慧娟 王子雄 马江山 《上饶师范学院学报》 2023年第3期1-6,共6页
证明了带粗糙核的分数次积分算子的交换子在Morrey-type空间上的加权估计,其中加权Morrey-type空间是加权Morrey空间的推广。
关键词 分数次积分算子 交换子 粗糙核 Morrey-type空间 加权估计
在线阅读 下载PDF
区间删失型数据下相依AFT模型的参数估计
13
作者 赵煜 候苗苗 《工程数学学报》 北大核心 2026年第2期373-382,共10页
在生存分析领域,区间删失数据是常见的数据类型。基于K型区间删失响应变量和区间删失型协变量,构建相依加速失效时间模型来研究失效时间与删失时间存在的相依关系。在该模型中,采用多项式核函数表述失效时间和删失时间的未知关系,并采用... 在生存分析领域,区间删失数据是常见的数据类型。基于K型区间删失响应变量和区间删失型协变量,构建相依加速失效时间模型来研究失效时间与删失时间存在的相依关系。在该模型中,采用多项式核函数表述失效时间和删失时间的未知关系,并采用Polya Tree分布对区间删失型协向量进行逼近,运用极大似然估计方法估计参数。模拟实验结果显示,该方法在不同情况下均取得较好效果,且当协向量彼此具有较强相关性时,非线性模型能够较好地拟合失效时间与删失时间的关系。最后,将所提出的方法和模型应用于临床试验数据进一步验证了其有效性。 展开更多
关键词 加速失效时间模型 K型区间删失 相依关系 删失时间 多项式核函数
在线阅读 下载PDF
IMPROVED GAGLIARDO-NIRENBERG INEQUALITIES ON HEISENBERG TYPE GROUPS 被引量:1
14
作者 罗光洲 《Acta Mathematica Scientia》 SCIE CSCD 2011年第4期1583-1590,共8页
Motivated by the idea of M. Ledoux who brings out the connection between Sobolev embeddings and heat kernel bounds, we prove an analogous result for Kohn’s sub-Laplacian on the Heisenberg type groups. The main result... Motivated by the idea of M. Ledoux who brings out the connection between Sobolev embeddings and heat kernel bounds, we prove an analogous result for Kohn’s sub-Laplacian on the Heisenberg type groups. The main result includes features of an inequality of either Sobolev or Galiardo-Nirenberg type. 展开更多
关键词 Heisenberg type group heat kernel Sobolev inequality Galiardo-Nirenberg inequality
在线阅读 下载PDF
FAST ALGORITHM FOR CALDERóN-ZYGMUND OPERATORS:CONVERGENCE SPEED AND ROUGH KERNEL
15
作者 杨奇祥 丁勇 《Acta Mathematica Scientia》 SCIE CSCD 2016年第2期345-358,共14页
In this article, we consider a fast algorithm for first generation Calderon-Zygmund operators. First, we estimate the convergence speed of the relative approximation algorithm. Then, we establish the continuity on Bes... In this article, we consider a fast algorithm for first generation Calderon-Zygmund operators. First, we estimate the convergence speed of the relative approximation algorithm. Then, we establish the continuity on Besov spaces and Triebel-Lizorkin spaces for the oper- ators with rough kernel. 展开更多
关键词 First generation Calderon-Zygmund operators WAVELETS rough kernel ring type operators Besov spaces and Triebel-Lizorkin spaces
在线阅读 下载PDF
TypeⅡ试验下ε(λ,μ)分布位置参数的EB估计
16
作者 叶尔骅 杨纪龙 《南京航空航天大学学报》 CAS CSCD 1995年第3期333-340,共8页
讨论了在TypeⅡ(无替换定数截尾)试验方案下,当产品寿命为双参数指数分布时,位置参数μ的经验Bayes(简记EB)估计及其收敛速度问题。设受试产品有n个,试验中前r个产品依次出现的失效时间为t(1)≤t(2)≤…≤... 讨论了在TypeⅡ(无替换定数截尾)试验方案下,当产品寿命为双参数指数分布时,位置参数μ的经验Bayes(简记EB)估计及其收敛速度问题。设受试产品有n个,试验中前r个产品依次出现的失效时间为t(1)≤t(2)≤…≤t(r),令记:μ的Bayes点估计为(x,y),利用密度函数及其偏导数的核估计构造出μ的EB估计为(x,y),(x,y)与(x,y)的Bayes风险分别为R_(2x)与R_(2m)。在一定的正则条件下,证明了这表明,μ的EB估计的收敛速度q可任意接近于1/4。 展开更多
关键词 统计分析 可靠性 指数分布 收敛速度
在线阅读 下载PDF
Singular Integral Operators on New BMO and Lipschitz Spaces of Homogeneous Type
17
作者 Peng LI Jiang ZHOU 《Journal of Mathematical Research with Applications》 CSCD 2016年第1期97-108,共12页
Let (X, d,u) be a space of homogeneous type, BMOA(X) and LiPA(β, X) be the space of BMO type, lipschitz type associated with an approximation to the identity {At}t〉0 and introduced by Duong, Yah and Tang, resp... Let (X, d,u) be a space of homogeneous type, BMOA(X) and LiPA(β, X) be the space of BMO type, lipschitz type associated with an approximation to the identity {At}t〉0 and introduced by Duong, Yah and Tang, respectively. Assuming that T is a bounded linear operator on L2(X), we find the sufficient condition on the kernel oft so that T is bounded from BMO (X) to BMOA (X) and from Lip(β, X) to LiPA (β, X). As an application, the boundedness of Calder6n-Zygmund operators with nonsmooth kernels on BMO(Rn) and Lip(β, Rn) are also obtained. 展开更多
关键词 singular integral operators BMO spaces Lipschitz spaces heat kernel spacesof homogeneous type
原文传递
Boundedness of Hyper-Singular Parametric Marcinkiewicz Integrals with Variable Kernels
18
作者 Qiquan Fang Xianliang Shi 《Applied Mathematics》 2013年第11期28-34,共7页
In this article, we consider the boundedness of? on Hardy type space? .
关键词 Hyper-Singular MARCINKIEWICZ Integral Variable kernel MULTILINEAR COMMUTATOR Hardy type Space
在线阅读 下载PDF
A NOTE ON LI-YAU-TYPE GRADIENT ESTIMATE
19
作者 Chengjie YU Feifei ZHAO 《Acta Mathematica Scientia》 SCIE CSCD 2019年第4期1185-1194,共10页
In this article, we obtain Li-Yau-type gradient estimates with time dependent parameter for positive solutions of the heat equation that are different with the estimates by Li-Xu [21] and Qian [23]. As an application ... In this article, we obtain Li-Yau-type gradient estimates with time dependent parameter for positive solutions of the heat equation that are different with the estimates by Li-Xu [21] and Qian [23]. As an application of the estimate, we also obtained slight improvements of Davies' Li-Yau-type gradient estimate. 展开更多
关键词 HEAT equation Li-Yau-type gradient ESTIMATE HEAT kernel
在线阅读 下载PDF
TOEPLITZ-TYPE OPERATORS ON LEBESGUE SPACES 被引量:9
20
作者 陆善镇 默会霞 《Acta Mathematica Scientia》 SCIE CSCD 2009年第1期140-150,共11页
Let L be the infinitesimal generator of an analytic semigroup on L 2 (Rn)with Gaussian kernel bounds,and L-α/ 2 be the fractional integrals generated by L for 0< α<n.Let Tj,1 be the singular integral with nons... Let L be the infinitesimal generator of an analytic semigroup on L 2 (Rn)with Gaussian kernel bounds,and L-α/ 2 be the fractional integrals generated by L for 0< α<n.Let Tj,1 be the singular integral with nonsmooth kernel related to L,or Tj,1=I, Tj,2,Tj,4 be the linear operators,which are bounded on Lp(Rn)for 1<p<∞,and Tj,3=±I(j=1,2,···,m),where I is the identity operator.For b∈L 1 loc (Rn),denote the Toeplitz-type operator byΘαbfmj=1(Tj,1MbIαTj,2 + Tj,3MbIαTj,4),where Mb is a multiplication ope... 展开更多
关键词 Toeplitz type operator generalized fractional integral singular integral with nonsmooth kernel Lipschitz function space
在线阅读 下载PDF
上一页 1 2 16 下一页 到第
使用帮助 返回顶部