期刊文献+
共找到211篇文章
< 1 2 11 >
每页显示 20 50 100
A Note on the Property of ψ-Function 被引量:2
1
作者 XIE Zitian ZHOU Qinghua 《Wuhan University Journal of Natural Sciences》 CAS 2011年第2期139-142,共4页
About the accurate value of ψ ( x ) = Γ′ ( x ) / Γ ( x), we know only ψ (1)and ψ (1/ 2).In this paper, by calculating the accurate values of some series expansion of a function and applying some skills... About the accurate value of ψ ( x ) = Γ′ ( x ) / Γ ( x), we know only ψ (1)and ψ (1/ 2).In this paper, by calculating the accurate values of some series expansion of a function and applying some skills of complex analysis, we prove that the expression of the ψ-function admits a finite expression in elementary function for rational number z. As an application, some examples are given. 展开更多
关键词 ψ-function Γ-function Euler’s constant
原文传递
A New Alpha-function for the Peng-Robinson Equation of State: Application to Natural Gas 被引量:3
2
作者 Hamid Saffari Alireza Zahedi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第10期1155-1161,共7页
Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The ind... Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The industrial applications of natural gas are very wide and as a result, prediction of thermodynamic properties and phase behavior of natural gas is an important part of design for such processes. In this work we develop a newα-function for the Peng-Robinson(PR) EOS with the parameters optimized especially for natural gas components.The parameters are generalized as a linear function of acentric factor. The results are compared to the predictions from original PR EOS and other α-functions in literature. It is shown that the new α-function presents a good accuracy with the average deviation of 1.42% for natural gas components. 展开更多
关键词 Peng-Robinson equation of state natural gas α-function
在线阅读 下载PDF
Azulenoisoindigo: A building block for π-functional materials with reversible redox behavior and proton responsiveness 被引量:1
3
作者 Bin Hou Jing Li +4 位作者 Xiaodi Yang Jianwei Zhang Hanshen Xin Congwu Ge Xike Gao 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第4期2147-2150,共4页
Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo anal... Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo analogue, is designed and synthesized, which has a twisted molecular backbone and R/Sisomers in single crystals. Interestingly, Az II shows the characteristics of both isoindigo and azulene,such as reversible redox behavior and reversible proton responsiveness. UV-vis-NIR,^(1)H NMR and electron paramagnetic resonance(EPR) measurements were carried out to get insights into the possible mechanism of the proton-responsive property of Az II. The results demonstrated that only one azulenyl moiety of molecule of Az II was protonated and deprotonated, and the protonated Az II can be further oxidized to form azulenium cation radicals. 展开更多
关键词 AZULENE Nonbenzenoid aromatic hydrocarbons Isoindigo π-functional materials Proton responsiveness
原文传递
Adsorptive removal of tetracycline from water using Fe(Ⅲ)-functionalized carbonized humic acid 被引量:1
4
作者 Dairui Xie Hongcheng Zhang +4 位作者 Meng Jiang Hao Huang Heng Zhang Yang Liao Shilin Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第10期2689-2698,共10页
Humic acid(HA)was carbonized at 300,400 and 500℃ and then functionalized with 1 wt%–12 wt%Fe(Ⅲ)respectively[CHA300/400/500-Fe(Ⅲ)].Adsorption of such Fe(III)-functionalized carbonized HA as adsorbents to aqueous te... Humic acid(HA)was carbonized at 300,400 and 500℃ and then functionalized with 1 wt%–12 wt%Fe(Ⅲ)respectively[CHA300/400/500-Fe(Ⅲ)].Adsorption of such Fe(III)-functionalized carbonized HA as adsorbents to aqueous tetracycline(TC:25 mg·L^-1)was studied.The adsorption equilibrium time for CHA400-Fe(Ⅲ)to TC was 6 h faster and the adsorption removal efficiency(Re)was two times higher than that of HA/CHA.The adsorption Reof CHA400-Fe(Ⅲ)loaded 10%iron[CHA400-(10%)Fe(Ⅲ)]to TC could reach 99.8%at 8 h and still kept80.6%after 8 cycles.The adsorption kinetics were well fitted to the pseudo-second-order equation and the adsorption isotherms could be well delineated via Langmuir equations(R^2N 0.99),indicating that the homogeneous chemical adsorption of TC occurred on the adsorbents.The main adsorption mechanisms of TC were complexation Fe(III)and hydrophobic distribution.Electropositive and electronegative repulsion between TC and CHA400-(10%)Fe(Ⅲ)at lowly p H(2)and highly p H(8–10)respectively,leaded to the relatively low adsorption capacity and more notable influence of ion concentration.When the p H was between 4 and 8,TC mainly existed in neutral molecules(TCH2),so the influence of ion concentration was not obvious.The dynamic adsorption results showed that the CHA400-(10%)Fe(Ⅲ)could continuously treat about 2.4 L TC(27 mg·L^-1)wastewater with the effluent concentration as low as 0.068 mg·L^-1.Our study suggested a broad application prospect of a new,effective,lowcost and environment-friendly adsorbent CHA400-(10%)Fe(Ⅲ)for treatment of low-concentration TC polluted wastewater. 展开更多
关键词 Fe(Ⅲ)-functionalized carbonized humic acid Composites ADSORPTION Low-concentration tetracycline Waste water
在线阅读 下载PDF
Comparative study of the adsorption performance of NH_(2)-functionalized metal organic frameworks with activated carbon composites for the treatment of phenolic wastewaters
5
作者 Bolong Jiang Shunjie Shi +3 位作者 Yanyan Cui Jiayou Li Nan Jiang Yanguang Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第11期130-139,共10页
To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that ... To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that the-NH_(2)group could increase the mesopore volume for composites,which promotes mass transfer and full utilization of active sites,because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites.Furthermore,the introduction of the-NH_(2)group can improve the adsorption capacity,decrease the activation energy,and enhance the interaction between the adsorbent and p-nitrophenol,demonstrating that the-NH_(2)group plays a crucial role in the adsorption of p-nitrophenol.The density functional theory calculation results show that the H-bond interaction between the-NH_(2)group in the adsorbent and the-NO_(2)in the p-nitrophenol(adsorption energy of -35.5 kJ·mol^(-1)),and base-acid interaction between the primary-NH_(2)group in the adsorbent and the acidic-OH group in the p-nitrophenol(adsorption energy of -27.3 kJ·mol^(-1))are predominant mechanisms for adsorption in terms of the NH_(2)-functionalized adsorbent.Both NH_(2)-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites.Among the composites,the NH_(2)-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^(-1). 展开更多
关键词 NH_(2)-functionalized adsorbent Phenolic wastewaters ADSORPTION Mechanism Density functional theory
在线阅读 下载PDF
The Symmetry of Riemann <i>ξ</i>-Function
6
作者 Chuanmiao Chen 《Advances in Pure Mathematics》 2020年第8期464-470,共7页
To prove RH, studying <span style="white-space:nowrap;">ζ and using pure analysis method likely are two kinds of the incorrect guide. Actually, a unique hope may study Riemann function <img src=&qu... To prove RH, studying <span style="white-space:nowrap;">ζ and using pure analysis method likely are two kinds of the incorrect guide. Actually, a unique hope may study Riemann function <img src="Edit_b4e53620-7ae2-4a2b-aee0-351c62aef8cd.png" width="250" height="20" alt="" /> by geometric analysis, which has the symmetry: <span style="white-space:nowrap;">v = 0 if <span style="white-space:nowrap;">β = 0, and <img src="Edit_8c67c5d7-c1d4-4cad-8792-78e4bd172ebd.png" width="150" height="28" alt="" /> Assume that |u| is single peak in each root-interval <img src="Edit_a91df253-2965-4b03-8033-54aba2e23036.png" width="85" height="27" alt="" /> of u for any fixed <span style="white-space:nowrap;">β <span style="white-space:nowrap;">∈ (0,1/2], using the slope u<sub>t </sub>of the single peak, we prove that v has opposite signs at two end-points of I<sub>j</sub>, there surely is an inner point so that v = 0, so {|u|,|v|/<span style="white-space:nowrap;">β}form a local peak-valley structure, and have positive lower bound <img src="Edit_04798c0f-8e21-4a3a-ae12-0e28b01ee348.png" width="167" height="22" alt="" />in I<sub>j</sub>. Because each t must lie in some <em style="white-space:normal;">I<sub style="white-space:normal;">j</sub> , then ||<span style="white-space:nowrap;">ξ|| > 0 is valid for any t. In this way, the summation process of <span style="white-space:nowrap;">ξ is avoided. We have proved the main theorem: Assume that u (t, <span style="white-space:nowrap;">β) is single peak, then RH is valid for any <img src="Edit_ed8521a3-63b1-417f-a3b0-a3c790bae519.png" width="140" height="19" alt="" />. If using the equivalence of Lagarias (1999), the assumption of single peak can be canceled. Therefore our new thinking is that we have found the local peak-valley structure of <span style="white-space:nowrap;">ξ, which may be the geometry structure expected by Bombieri (2000), and proposed a basic framework of proving RH by geometric analysis. 展开更多
关键词 Riemann ξ-function SYMMETRY Peak-Valley Structure Single Peak RH
在线阅读 下载PDF
GENERALIZED FRACTIONAL CALCULUS OF THE ALEPH-FUNCTION INVOLVING A GENERAL CLASS OF POLYNOMIALS
7
作者 R.K.SAXENA D.KUMAR 《Acta Mathematica Scientia》 SCIE CSCD 2015年第5期1095-1110,共16页
The object of this article is to study and develop the generalized fractional calcu- lus operators given by Saigo and Maeda in 1996. We establish generalized fractional calculus formulas involving the product of R-fun... The object of this article is to study and develop the generalized fractional calcu- lus operators given by Saigo and Maeda in 1996. We establish generalized fractional calculus formulas involving the product of R-function, Appell function F3 and a general class of poly- nomials. The results obtained provide unification and extension of the results given by Saxena et al. [13], Srivastava and Grag [17], Srivastava et al. [20], and etc. The results are obtained in compact form and are useful in preparing some tables of operators of fractional calculus. On account of the general nature of the Saigo-Maeda operators, R-function, and a general class of polynomials a large number of new and known results involving Saigo fractional calculus operators and several special functions notably H-function, /-function, Mittag-Leffier function, generalized Wright hypergeometric function, generalized Bessel-Maitland function follow as special cases of our main findings. 展开更多
关键词 generalized fractional calculus operators a general class of polynomials R-function H-function /-function generalized Wright hypergeometric function Mittag-Leffler function generalized Bessel-Maitland function
在线阅读 下载PDF
AGGREGATE SPECIAL FUNCTIONS TO APPROXIMATE PERMUTING TRI-HOMOMORPHISMS AND PERMUTING TRI-DERIVATIONS ASSOCIATED WITH A TRI-ADDITIVEψ-FUNCTIONAL INEQUALITY IN BANACH ALGEBRAS
8
作者 Safoura Rezaei ADERYANI Azam AHADI +1 位作者 Reza SAADATI Hari M.SRIVASTAVA 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期311-338,共28页
In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better... In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better estimation for permuting tri-homomorphisms and permuting tri-derivations in unital C*-algebras and Banach algebras by the vector-valued alternative fixed point theorem. 展开更多
关键词 permuting tri-homomorphism in Banach algebra permuting tri-derivation on C*-algebra fixed point theorem Ulam-Hyers-Rassias stability aggregate special functions tri-additiveψ-functional inequality
在线阅读 下载PDF
Synthesis and Characterization of α-End Functionalized 3,4-Polyisoprene Using Fe(acac)_(3)/IITP/AliBu_(3)Catalyst
9
作者 Yu-Fan Sun Ying-Nan Zhao +8 位作者 Shi-Liang Xu Yao Yu Liang Fang Li-Hua Na Qi Yang Feng Wang Heng Liu Chun-Yu Zhang Xue-Quan Zhang 《Chinese Journal of Polymer Science》 2025年第8期1367-1374,共8页
The synthesis of functionalized rubber copolymers is a topic of great research interest.In this study,we present a novel approach for the direct construction ofα-functionalized 3,4-polyisoprene through polymerization... The synthesis of functionalized rubber copolymers is a topic of great research interest.In this study,we present a novel approach for the direct construction ofα-functionalized 3,4-polyisoprene through polymerization of polar monomers and isoprene monomer.Theα-functionalized 3,4-polyisoprene was successfully synthesized via in situ sequential polymerization using the iron-based catalytic system(Fe(acac)_(3)/IITP/AliBu_(3)),exhibiting high activity and resistance to polar monomers without requiring protection of polar groups.The structure ofα-functionalized 3,4-polyisoprene was confirmed by proton nuclear magnetic resonance spectroscopy(^(1)H-NMR)and two-dimensional diffusion-ordered spectroscopy(2D DOSY)spectra analysis.The introduction of polar groups,particularly hydroxyl groups,enhanced the hydrophilicity of the copolymer.This was evidenced by a decrease in the water contact angle from 106.9°to 96.4°with increasing hydroxyl content in the copolymer. 展开更多
关键词 Iron-based catalyst 3 4-Polyisoprene α-functionalized In situ sequential polymerization HYDROPHILICITY
原文传递
Parameterized Littlewood-Paley Operators and Their Commutators on Two-Weight Grand Homogeneous Variable Herz-Morrey Spaces
10
作者 Xijuan CHEN Wenwen TAO Guanghui LU 《Journal of Mathematical Research with Applications》 2025年第2期231-242,共12页
In this paper,the authors prove that the parameterized area integralμ_(Ω,S)^(ρ)and the parameterized Littlewood-Paley g_(δ)^(*)-functionμ_(Ω,δ)^(*,ρ)are bounded on two-weight grand homogeneous variable Herz-Mo... In this paper,the authors prove that the parameterized area integralμ_(Ω,S)^(ρ)and the parameterized Littlewood-Paley g_(δ)^(*)-functionμ_(Ω,δ)^(*,ρ)are bounded on two-weight grand homogeneous variable Herz-Morrey spaces MK_(p),θ,q(·))^(α(·),λ)(ω_(1),ω_(2)),where θ>0,λ∈(2,∞),q(·)∈B(R^(n)),α(·)∈L^(∞)(R^(n)),ω_(1)∈A_(p_(ω_(1)))for p_(ω_(1))∈[1,∞]and ω_(2) is a weight.Furthermore,the authors prove that the commutators[b,μ_(Ω,S)^(ρ)]which is formed by b∈BMO(R^(n))and the μ_(Ω,S)^(ρ),and the[b,μ_(Ω,δ)^(*,ρ)]generated by b∈BMO(R^(n))and theμ_(Ω,δ)^(*,ρ)are bounded on MK_(p),θ,q(·))^(α(·),λ)(ω_(1),ω_(2)),respectively. 展开更多
关键词 Grand homogeneous variable Herz-Morrey space parameterized area integral parameterized Littlewood-Paley g_(δ)^(*)-function commutator space BMO(R^(n))
原文传递
相关函数法计算容性设备介质损失角正切 被引量:32
11
作者 王楠 律方成 +1 位作者 李燕青 陈志业 《华北电力大学学报(自然科学版)》 CAS 北大核心 2001年第3期22-25,共4页
首先简要介绍了当前常用的介质损耗测量方法及其存在的问题,然后分析了计算容性设备介质损失角正切的相关函数法,并提出了基于抛物插值的改进算法,比较了改进前后算法的有效性,分析了算法的误差影响,通过仿真算例进行了验证,最后... 首先简要介绍了当前常用的介质损耗测量方法及其存在的问题,然后分析了计算容性设备介质损失角正切的相关函数法,并提出了基于抛物插值的改进算法,比较了改进前后算法的有效性,分析了算法的误差影响,通过仿真算例进行了验证,最后对计算精度的改进提出了更好的设想。 展开更多
关键词 介质损失角正切 相关函数法 抛物插值 容性设备 计算
在线阅读 下载PDF
频率域线源大地电磁法有限元正演模拟 被引量:50
12
作者 王若 王妙月 底青云 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2006年第6期1858-1866,共9页
本文介绍了频率域线源大地电磁法有限元正演模拟的研究结果.在外边界上统一应用适合于人工源的一阶吸收边界条件来形成边值问题,可减小基于平面波假设造成的人为截断边界的影响.程序编辑中设计了两个二维数组分别存储总体系数矩阵的非... 本文介绍了频率域线源大地电磁法有限元正演模拟的研究结果.在外边界上统一应用适合于人工源的一阶吸收边界条件来形成边值问题,可减小基于平面波假设造成的人为截断边界的影响.程序编辑中设计了两个二维数组分别存储总体系数矩阵的非零元素和在总体结点编号中的位置,使内存占用量减少,且物理意义明确,方便用高斯-赛德尔等迭代法解有限元方程时调用.采用视δ函数模拟线源,提高了解方程组的稳定性.最后通过对1个简单模型和1个复杂模型的模拟,证明所用的方法对异常体能够有明显的反映,说明了该方法的可靠性和有效性. 展开更多
关键词 频率域 线源 有限元法 正演 一阶吸收边界条件 压缩存储系数矩阵 视δ函数 高斯-塞德尔迭代法
在线阅读 下载PDF
Kriging插值无网格方法及其在力学边值问题中的应用 被引量:8
13
作者 樊成 栾茂田 +1 位作者 黎勇 杨庆 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2007年第1期195-200,共6页
在传统的无网格Galerkin法中,采用滑动Kriging插值方法构造形函数,并与无网格方法相结合建立一种新的无网格方法。依此方法所构造的形函数具有Kroneckerδ-函数属性,便于直接施加强制边界条件。结合弹性力学边值问题,阐述该方法的基本原... 在传统的无网格Galerkin法中,采用滑动Kriging插值方法构造形函数,并与无网格方法相结合建立一种新的无网格方法。依此方法所构造的形函数具有Kroneckerδ-函数属性,便于直接施加强制边界条件。结合弹性力学边值问题,阐述该方法的基本原理,进而通过算例计算与分析,考察该方法的计算精度及其效率。 展开更多
关键词 数值分析 无网格方法 KRIGING插值 KRONECKER δ-函数属性
在线阅读 下载PDF
集中力作用下的两相饱和介质位移场Green函数 被引量:13
14
作者 丁伯阳 丁翠红 孟凡丽 《力学学报》 EI CSCD 北大核心 2001年第2期234-241,共8页
以复模两相饱和介质Biot动力学方程为基础,根据该方程D’Alembert解的Fourier变换所属的Homholtz方程特性,由Biot方程解的相容性条件及δ函数性质较好地解决了快、慢纵波位势的耦合问题,较为简便地... 以复模两相饱和介质Biot动力学方程为基础,根据该方程D’Alembert解的Fourier变换所属的Homholtz方程特性,由Biot方程解的相容性条件及δ函数性质较好地解决了快、慢纵波位势的耦合问题,较为简便地得到了两相饱和介质在集中力作用下低频(ω<ωc)时的频域和时域的Green函数. 展开更多
关键词 集中力 两相饱和介质 GREEN函数 位移场 Homholtz方程 Δ函数
在线阅读 下载PDF
SAW器件叉指换能器δ函数模型的改进 被引量:5
15
作者 王代强 陈雨青 +1 位作者 徐稀嫔 刘桥 《电子元件与材料》 CAS CSCD 北大核心 2010年第9期62-65,共4页
通过对传统SAW器件的叉指换能器(IDT)的δ函数模型进行分析,研究了δ函数模型的改进方法。将一根叉指指条分解成若干个边长为αik的正方形,并把这个正方形而不是整根叉指条看成一个独立声波激发源,表示为基本δ函数单元,这可引入叉指指... 通过对传统SAW器件的叉指换能器(IDT)的δ函数模型进行分析,研究了δ函数模型的改进方法。将一根叉指指条分解成若干个边长为αik的正方形,并把这个正方形而不是整根叉指条看成一个独立声波激发源,表示为基本δ函数单元,这可引入叉指指条宽度及耦合孔径等影响SAW器件性能的因素,仿真分析及实验结果表明,改进后的δ函数模型更适合对变迹加权后的IDT进行精确计算。 展开更多
关键词 δ函数模型 IDT变迹加权 基本δ函数单元 叉指换能器
在线阅读 下载PDF
交通载荷下管道的位移响应分析初探 被引量:7
16
作者 吴小刚 吴军 宋洁人 《仪器仪表学报》 EI CAS CSCD 北大核心 2006年第z1期14-15,共2页
基于单位脉冲(函数属性以及傅里叶级数技术,建立了随机交通荷载下管道的Eular-Bernoulli弹性地基梁受力模型对管道的位移响应进行了解析计算,模型中考虑了管道所受的阻尼,并进一步探讨了考虑管土系统动态参数特性时求解梁响应的解析算法... 基于单位脉冲(函数属性以及傅里叶级数技术,建立了随机交通荷载下管道的Eular-Bernoulli弹性地基梁受力模型对管道的位移响应进行了解析计算,模型中考虑了管道所受的阻尼,并进一步探讨了考虑管土系统动态参数特性时求解梁响应的解析算法,从而为地下管道受载荷作用下的力学性状研究提供了简捷、明析的解题方法。 展开更多
关键词 地下管道 交通荷载 Δ函数 动态参数
在线阅读 下载PDF
高压传感器在高静压下的动态校准方法 被引量:7
17
作者 张瑜 裴东兴 祖静 《传感技术学报》 CAS CSCD 北大核心 2011年第8期1146-1150,共5页
提出了一种校准高压传感器频响特性的方法,动态校准系统主要由甘油油腔、霍普金森杆、气枪、应变片、电荷放大器、活塞式压力计和数据采集系统等组成。校准时先利用活塞式压力计在封闭式油腔中产生高静压,高静压作用于被校准的压力传感... 提出了一种校准高压传感器频响特性的方法,动态校准系统主要由甘油油腔、霍普金森杆、气枪、应变片、电荷放大器、活塞式压力计和数据采集系统等组成。校准时先利用活塞式压力计在封闭式油腔中产生高静压,高静压作用于被校准的压力传感器。气枪发射子弹,子弹撞击霍普金森杆产生近似于冲激函数的窄脉冲应力波,应力波通过甘油传播并激励传感器,数据采集系统同时采集激励信号和传感器的输出信号,最后计算出被校传感器的频响特性。分析了瞬态信号的脉宽与频率校准范围的关系。该校准方法是高压测试系统动态校准的理想方法,实现了高压下压力传感器的动态校准,可校准的下限频率严格地达到零频,为动态高压测试提供有效的计量手段。 展开更多
关键词 高压 压力传感器 动态校准 频率响应 准δ函数
在线阅读 下载PDF
利用δ函数计算间歇试采井压力分布 被引量:5
18
作者 张衍臣 卢德唐 +1 位作者 马华丽 戴江 《石油学报》 EI CAS CSCD 北大核心 2006年第2期98-102,共5页
δ函数是一个用于描述非连续分布物理量的数学工具,利用δ函数的相关理论和性质,采用密度方程求解瞬时注入或采出δm量流体后(集中分布的物理量)的地层压力分布,对这个集中分布量的地层压力进行叠加,模拟了间歇采油井的压力分布和井底... δ函数是一个用于描述非连续分布物理量的数学工具,利用δ函数的相关理论和性质,采用密度方程求解瞬时注入或采出δm量流体后(集中分布的物理量)的地层压力分布,对这个集中分布量的地层压力进行叠加,模拟了间歇采油井的压力分布和井底压力。利用井底压力的表达式进行间歇采油井的压力历史拟合,为间歇采油井的试井分析和产能评价提供了依据。对大庆油田一口间歇井进行了实例计算,并与实测数据进行了对比,该方法的计算结果符合间断流动状态地层压力分布的实际情况。 展开更多
关键词 Δ函数 间歇试采 压力分布 产能评价 试井分析 叠加原理
在线阅读 下载PDF
有限覆盖径向点插值法及其在土工问题中的应用 被引量:4
19
作者 栾茂田 樊成 +1 位作者 黎勇 杨庆 《岩土力学》 EI CAS CSCD 北大核心 2006年第12期2143-2148,共6页
将有限覆盖技术与径向点插值方法相结合发展了有限覆盖径向点插值无网格方法,从而综合了数值流形方法与点插值方法的各自优点,能够有效地处理连续与非连续性问题。用该方法构造的形函数具有Kroneckerδ-函数属性,方便了位移边界条件的... 将有限覆盖技术与径向点插值方法相结合发展了有限覆盖径向点插值无网格方法,从而综合了数值流形方法与点插值方法的各自优点,能够有效地处理连续与非连续性问题。用该方法构造的形函数具有Kroneckerδ-函数属性,方便了位移边界条件的处理。在简要阐述了这种方法基本原理的基础上,将该方法用用于地基附加应力计算分析,结果证明本文方法精度高,方法简单有效。 展开更多
关键词 有限覆盖 无网格方法 径向点插值 KRONECKER δ-属性
在线阅读 下载PDF
放入式电子测压器的校准技术研究 被引量:7
20
作者 杨文 张瑜 祖静 《传感技术学报》 CAS CSCD 北大核心 2015年第9期1384-1388,共5页
电子测压器是理想的火炮膛压测试仪器,用经过静态标定的测压器测得的火炮膛压峰值与铜柱测压器测得的峰值相比散布很大。究其原因可能是选用的压力传感器的带宽无法完全覆盖膛压信号的带宽,也可能是火炮发射时的恶劣环境改变了传感器的... 电子测压器是理想的火炮膛压测试仪器,用经过静态标定的测压器测得的火炮膛压峰值与铜柱测压器测得的峰值相比散布很大。究其原因可能是选用的压力传感器的带宽无法完全覆盖膛压信号的带宽,也可能是火炮发射时的恶劣环境改变了传感器的动态特性。针对上述问题,通过准δ函数校准法得出压力传感器的频响特性完全满足测量膛压的要求。设计了模拟膛压校准装置,能模拟火炮膛内高温高压环境,产生幅值在80 MPa^800 MPa,脉宽在10 ms^20 ms的压力信号。实弹测试数据表明,经过模拟应用环境校准后的测压器所测压力峰值分布稳定性好、置信度高。 展开更多
关键词 准δ函数校准法 模拟应用环境 电子测压器 高精度
在线阅读 下载PDF
上一页 1 2 11 下一页 到第
使用帮助 返回顶部