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现用△P 值测定方法的局限性及其改进 被引量:1
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作者 杨福蓉 王佑安 《煤矿安全》 CAS 北大核心 1992年第8期27-30,共4页
煤的瓦斯放散初速度指标ΔP 值的实质是煤在0.1MPa 压力吸附瓦斯条件下,向一固定体积的真空空间放散时,10~60秒时间内所放散的瓦斯量(即ΔP<sub>10-60</sub>)。对瓦斯放散速度随时间衰减不十分大的煤来说,这种测定方法是... 煤的瓦斯放散初速度指标ΔP 值的实质是煤在0.1MPa 压力吸附瓦斯条件下,向一固定体积的真空空间放散时,10~60秒时间内所放散的瓦斯量(即ΔP<sub>10-60</sub>)。对瓦斯放散速度随时间衰减不十分大的煤来说,这种测定方法是适用的,但对瓦斯放散初速度异常大且随时间衰减异常快的煤来说。 展开更多
关键词 瓦斯 测定 △p值 局限性
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Location of emergency rescue center based on SIR epidemiological model 被引量:3
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作者 胡家香 赵林度 江亿平 《Journal of Southeast University(English Edition)》 EI CAS 2007年第S1期89-93,共5页
In view of the pressure time of emergency rescue against the infectious diseases,a mathematical model to optimize the location of emergency rescue centers is proposed.The model takes full account of the spread functio... In view of the pressure time of emergency rescue against the infectious diseases,a mathematical model to optimize the location of emergency rescue centers is proposed.The model takes full account of the spread function of infectious diseases,the cycle of pulse vaccination,the distance between the demand area and the emergency rescue centers,as well as the building and maintenance cost for the emergency rescue center,and so on.At the same time,the model integrates the traditional location selection models which are the biggest cover model,the p-center model and the p-median model,and it embodies the principles of fairness and efficiency for the emergency center location.Finally,a computation of an example arising from practice provides satisfactory results. 展开更多
关键词 susceptible-infective-removed(SIR)model pulse vaccination LOCATION emergency rescue p-median model
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“瓦斯放散初速度”△P 测定中的问题与改进
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作者 鲁宗厚 《工业安全与防尘》 1992年第9期39-41,共3页
在煤矿防止煤和瓦斯突出工作中,△P值是个很重要的技术参数。它是描述突出煤与非突出煤释放瓦斯速度不同的一个物理量概念,我国和世界上不少国家都用以作为判断煤与瓦斯突出危险程度的单项指标之一。1988年,原煤炭工业部制订的《防治煤... 在煤矿防止煤和瓦斯突出工作中,△P值是个很重要的技术参数。它是描述突出煤与非突出煤释放瓦斯速度不同的一个物理量概念,我国和世界上不少国家都用以作为判断煤与瓦斯突出危险程度的单项指标之一。1988年,原煤炭工业部制订的《防治煤与瓦斯突出细则》明确规定。 展开更多
关键词 瓦斯 △p值 测定
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On a Class of p-valent Analytic Functions
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作者 刘金林 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期27-32,共6页
In this paper we consider the extreme points of closed convex hull of the class T σ(p,α) and then it is used to determine the coefficient bounds. Some other interesting properties of the class T σ(p,α) are also... In this paper we consider the extreme points of closed convex hull of the class T σ(p,α) and then it is used to determine the coefficient bounds. Some other interesting properties of the class T σ(p,α) are also investigated. 展开更多
关键词 convex hull p-VALENT SUBORDINATION best dominant
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Existence of Solutions for S-L Singular Boundary Value Problems with p-Laplacian Operators
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作者 郭彦平 葛渭高 单文锐 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期220-224,共5页
The existence of solutions for singular nonlinear two point boundary value problems subject to Sturm Liouville boundary conditions with p Laplacian operators is studied by the method of upper and lower solution... The existence of solutions for singular nonlinear two point boundary value problems subject to Sturm Liouville boundary conditions with p Laplacian operators is studied by the method of upper and lower solutions. The proof is based on an application of Schauder’s fixed point theorem to a modified problem whose solutions are that of the original one. At the same time, Arzela Ascoli theorem is used to prove that the defined operator N is a compact map. 展开更多
关键词 nonlinear boundary value problems p Laplacian operators fixed point upper solution lower solution
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Evaluation of CA125 and NT-proBNP values in patients undergoing transcatheter aortic valve implantation 被引量:5
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作者 Huseyin Ayhan Haca Ahmet Kasapkara +8 位作者 Tahir Durmaz Telat Keles Cenk San Serdal Bastug Kemal Esref Erdogan Nihal Akar Bayram Emine Bilen Murat Akgay Engin Bozkurt 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第2期100-106,共7页
Background Transcatheter aortic valve implantation (TAVI) is a minimally invasive, emerging therapy in surgically high risk, or in- operable patients. Parameters used for risk classification have some deficiencies i... Background Transcatheter aortic valve implantation (TAVI) is a minimally invasive, emerging therapy in surgically high risk, or in- operable patients. Parameters used for risk classification have some deficiencies in the selection of patients. The objective of this study is to evaluate the impact of TAVI on carbohydrate antigen 125 (CA125) and N-terminal pro brain-type natriuretic peptide (NT-proBNP) as biomarkers that have been used frequently in recent years, and also the relationship of these biomarkers to prognosis. Methods & Results Transcatheter aortic valve implantation was practiced on 31 patients in this study. Then, CA125 and NT-proBNP levels studied in patients prior to and after the TAVI were evaluated. The patients were also grouped in accordance with their left ventrieular ejection fraction (LVEF) and CA125 levels (LVEF 〉 40% and 〈 40%; CA125 ≤ 35 U/L and 〉 35 U/L). The TAVI operation was successfully performed in all patients. There was no in-hospital mortality and substantial improvement in functional capacity was detected at follow ups. In addition, a statistically significant decrease was detected in post-TAVI CA 125 and NT-proBNP levels of all patients (CA 125 83.8 ± 18.1 U/L vs. 64.3 ±14.2 U/L, P = 0.008; NT-proBNP: 4633.6± 627.6 pg/mL vs. 2866.3±536.8 pg/mL, P 〈 0.001). In groups divided according to the CA125 levels, there was also statistically significant post-TAVI decline in CA125 levels. Within CA125 〉 35 U/L and LVEF 〈 40% groups, the permanent need for a pacemaker was required in one (3.2%) patient and mortality was observed in two (6.4%) patients after TAVI at follow up. Conclusions The results show that TAVI can be performed effectively and reliably in patients with high baseline levels of CA125 and NT-proBNP. These biomarkers are reduced substantially with TAVI, while high biomarker levels are associated with undesired events, and certainly, these biomarkers can be used for risk classifications in patient selection for TAVI. 展开更多
关键词 B-type natriuretic peptide BIOMARKER Carbohydrate antigen Heart failure Transcatheter aortic valve implantation Risk score
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Existence of Multiple Positive Solutions for Higher-Order p-Laplacian Boundary Value Problems
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作者 贺小明 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期212-216,共5页
The existence of multiple positive solutions for a class of higher order p Laplacian boundary value problem is studied. By means of the Leggett Williams fixed point theorem in cones, existence criteria which e... The existence of multiple positive solutions for a class of higher order p Laplacian boundary value problem is studied. By means of the Leggett Williams fixed point theorem in cones, existence criteria which ensure the existence of at least three positive solutions of the boundary value problem are established. 展开更多
关键词 positive solutions cone Leggett Williams fixed point theorem p Laplacian boundary value problems
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An Intelligent Early Warning Method of Press-Assembly Quality Based on Outlier Data Detection and Linear Regression
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作者 XUE Shanliang LI Chen 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第4期597-606,共10页
Focusing on controlling the press-assembly quality of high-precision servo mechanism,an intelligent early warning method based on outlier data detection and linear regression is proposed.Linear regression is used to d... Focusing on controlling the press-assembly quality of high-precision servo mechanism,an intelligent early warning method based on outlier data detection and linear regression is proposed.Linear regression is used to deal with the relationship between assembly quality and press-assembly process,then the mathematical model of displacement-force in press-assembly process is established and a qualified press-assembly force range is defined for assembly quality control.To preprocess the raw dataset of displacement-force in the press-assembly process,an improved local outlier factor based on area density and P weight(LAOPW)is designed to eliminate the outliers which will result in inaccuracy of the mathematical model.A weighted distance based on information entropy is used to measure distance,and the reachable distance is replaced with P weight.Experiments show that the detection efficiency of the algorithm is improved by 5.6 ms compared with the traditional local outlier factor(LOF)algorithm,and the detection accuracy is improved by about 2%compared with the local outlier factor based on area density(LAOF)algorithm.The application of LAOPW algorithm and the linear regression model shows that it can effectively carry out intelligent early warning of press-assembly quality of high precision servo mechanism. 展开更多
关键词 quality early warning outlier data detection linear regression local outlier factor based on area density and p weight(LAOpW) information entropy p weight
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Inflnence of PH on Chemical Forms of Phosphate Ad-sorbed on Goethite Snrfaces
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作者 LIU FAN ̄1 JIE XIAO-LEIl ̄1 +3 位作者 ZHOU DAI-HUA ̄1 Ll XUE-YUAN ̄1 HE JI-ZHENG ̄1 XUFENGLIN ̄1 and WANG DIAN-FEN ̄2( Huazhong Agricultural Unzverszty, Wuhan 43O070 ( China)(Wuhan Unzverszty of Technology, Wuhan 450070 (China) 《Pedosphere》 SCIE CAS CSCD 1995年第2期157-162,共6页
Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinategroups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results sho... Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinategroups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results showed that the chemical forms of P on goethite surfaces changed from the dominance of monodentatecorrdination to that of bidentate one with increasing pH of the solution. By influencing types of phosphateions in solutions, pH affected the chemical forms of P on goethite surfaces. The amount of OH ̄- displacedby phosphate on goethite surfaces was the most at pH 7.0, the second at pH 9.0, and the least at pH 4.5. 展开更多
关键词 GOETHITE pH phosphate adsorption X-ray photoelectron spectroscopy
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Equivalent Doping Transformation Method for Predicting Breakdown Voltage and Peak Field at Breakdown of Epitaxial-Diffused Punch-Through Junction
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作者 何进 张兴 +1 位作者 黄如 王阳元 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第3期256-260,共5页
Based on a new semi empirical analytical method, namely equivalent doping transformation, the breakdown voltage and the peak field of the epitaxial diffused punch through junction have been obtained. The basic prin... Based on a new semi empirical analytical method, namely equivalent doping transformation, the breakdown voltage and the peak field of the epitaxial diffused punch through junction have been obtained. The basic principle of this method is introduced and a set of breakdown voltage and peak field plots are provided for the optimum design of the low voltage power devices. It shows that the analytical results coincide with the previous numerical simulation well. 展开更多
关键词 epitaxial diffused punch through junction breakdown voltage peak field equivalent doping transformation
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Discriminating between explosions and earthquakes
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作者 Cho Kwang-Hyun 《Applied Geophysics》 SCIE CSCD 2014年第4期429-436,509,510,共10页
Earthquake, explosion, and a nuclear test data are compared with forward modeling and band-pass filtered surface wave amplitude data for exploring methodologies to improve earthquake–explosion discrimination. The pro... Earthquake, explosion, and a nuclear test data are compared with forward modeling and band-pass filtered surface wave amplitude data for exploring methodologies to improve earthquake–explosion discrimination. The proposed discrimination method is based on the solutions of a double integral transformation in the wavenumber and frequency domains. Recorded explosion data on June 26, 2001(39.212°N, 125.383°E) and October 30, 2001(38.748°N, 125.267°E), a nuclear test on October 9, 2006(41.275°N, 129.095°E), and two earthquakes on April 14, 2002(39.207°N, 125.686°E) and June 7, 2002(38.703°N, 125.638°E), all in North Korea, are used to discriminate between explosions and earthquakes by seismic wave analysis and numerical modeling. The explosion signal is characterized by first P waves with higher energy than that of S waves. Rg waves are clearly dominant at 0.05–0.5 Hz in the explosion data but not in the earthquake data. This feature is attributed to the dominant P waves in the explosion and their coupling with the SH components. 展开更多
关键词 explosion EARTHQUAKE nuclear test p wave Rg wave numerical modeling
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An approximation to the P-wave reflection coefficient for amplitude variation with long-offset seismic data 被引量:1
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作者 Wang Pu Zhang Wenpo Hu Tianyue 《Applied Geophysics》 SCIE CSCD 2007年第1期29-36,共8页
In recent years, long-offset exploration has been widely used, especially on marine seismic surveys. Conventional AVO analysis is insufficient for long-offset seismic data. To widen the application range of AVO analys... In recent years, long-offset exploration has been widely used, especially on marine seismic surveys. Conventional AVO analysis is insufficient for long-offset seismic data. To widen the application range of AVO analysis, we present a new P-wave reflection coefficient approximation applicable to long-offset data. Our result is similar to the well known Shuey formula which can be treated as an approximation to our results for short-offset seismic data. 展开更多
关键词 AVO long-offset Zoeppritz equations poisson's ratio.
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Laboratory investigation on relationship between degree of saturation, B-value and P-wave velocity 被引量:4
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作者 GU Xiao-qiang YANG Jun HUANG Mao-song 《Journal of Central South University》 SCIE EI CAS 2013年第7期2001-2007,共7页
Laboratory tests were performed on Toyoura sand specimens to investigate the relationship between degree of saturation Sr, B-value and P-wave velocity Vp. Different types of pore water (de-aired water or tap water) ... Laboratory tests were performed on Toyoura sand specimens to investigate the relationship between degree of saturation Sr, B-value and P-wave velocity Vp. Different types of pore water (de-aired water or tap water) and pore gas (air or CO2) as well as different magnitudes of back pressure were used to achieve different Sr (or B-value). The measured relationship between B-value and Vp was not consistent with the theoretical prediction. The measurement shows that the Vp value in the specimen flushed with de-aired water is independent of B-value (or St) and is always around the one in fully saturated condition. However, the Vp value in the specimen flushed with tap water increases with B-value, but the shape of the relationship between Vp and B-value is quite different from the theoretical prediction. The possible explanation for the discrepancy between laboratory measurement and theoretical prediction lies in that the air exists in the water as air bubbles and therefore the pore fluid (air-water mixture) is heterogeneous instead of homogenous assumed in the theoretical prediction. 展开更多
关键词 degree of saturation B-VALUE p-wave velocity bender element
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Application of a joint algorithm based on L-T to pulse pressure detection signal of fiber Fabry-Perot nano pressure sensor
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作者 FENG Fei QIN Li 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第1期61-67,共7页
An improved denoising method and its application in pulse beat signal denoising are studied.The proposed denoising algorithm takes the advantages of local mean decomposition(LMD)and time-frequency peak filtering(TFPF)... An improved denoising method and its application in pulse beat signal denoising are studied.The proposed denoising algorithm takes the advantages of local mean decomposition(LMD)and time-frequency peak filtering(TFPF),called L-T algorithm.As a classical time-frequency filtering method,TFPF can effectively suppress random noise with signal amplitude retained when selecting a longer window length,while the signal amplitude will be seriously attenuated when selecting a shorter window length.In order to maintain effective signal amplitude and suppress random noise,LMD and TFPF are improved.Firstly,the original signal is decomposed into progression-free survival(PFS)by LMD,and then the standard error of mean(SEM)of each product function is calculated to classify many PFSs into useful component,mixed component and noise component.Secondly,by using the shorter window TFPF for useful component and the longer window TFPF for mixed component,noise component is removed and the final signal is obtained after reconstruction.Finally,the proposed algorithm is used for noise reduction of an Fabry-Perot(F-P)pressure sensor.Experimental results show that compared with traditional wavelet,L-T algorithm has better denoising effect on sampled data. 展开更多
关键词 local mean decomposition(LMD) time-frequency peak filtering(TFpT) noise reduction Fabry-perot(F-p)sensor
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{P,Q,k+1}-reflexive solutions to a system of matrix equations 被引量:1
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作者 LI Jie WANG Qingwen 《应用数学与计算数学学报》 2018年第3期619-630,共12页
In this paper,we investigate the{P,Q,k+1}-reflexive and anti-reflexive solutions to the system of matrix equations AX=C,XB=D and AXB=E.We present the necessary and sufficient conditions for the system men-tioned above... In this paper,we investigate the{P,Q,k+1}-reflexive and anti-reflexive solutions to the system of matrix equations AX=C,XB=D and AXB=E.We present the necessary and sufficient conditions for the system men-tioned above to have the{P,Q,k+1}-reflexive and anti-reflexive solutions.We also obtain the expressions of such solutions to the system by the singular value decomposition.Moreover,we consider the least squares{P,Q,k+1}-reflexive and anti-reflexive solutions to the system.Finally,we give an algorithm to illustrate the results of this paper. 展开更多
关键词 matrix equation least squares solution {p Q k%pLUS%1}-reflexive and anti-reflexive solution singular value decomposition
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Multiple Positive Solutions to a Nonlinear Two-point Boundary Value Problem with p-Laplacian 被引量:4
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作者 李志艳 严树林 葛渭高 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2006年第3期480-488,共9页
By a simple application of a new three functionals fixed point theorem, sufficient conditions axe obtained to guarantee the existence of at least three positive solutions for p-Laplacian equation: (φp(u′))′ +... By a simple application of a new three functionals fixed point theorem, sufficient conditions axe obtained to guarantee the existence of at least three positive solutions for p-Laplacian equation: (φp(u′))′ + α(t)f(t,u(t)) = 0 subject to nonlinear boundary value conditions. An example is presented to illustrate the theory. 展开更多
关键词 boundary value problem p-Laplacian operator positive solution the threefunctionals fixed point theorem.
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Minimization of eigenvalues and construction of non-degenerate potentials for the one-dimensional p-Laplacian 被引量:1
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作者 WEN ZhiYuan ZHANG MeiRong 《Science China Mathematics》 SCIE CSCD 2016年第1期49-66,共18页
We first use the Schwarz rearrangement to solve a minimization problem on eigenvalues of the one-dimensional p-Laplacian with integrable potentials. Then we construct an optimal class of non-degenerate potentials for ... We first use the Schwarz rearrangement to solve a minimization problem on eigenvalues of the one-dimensional p-Laplacian with integrable potentials. Then we construct an optimal class of non-degenerate potentials for the one-dimensional p-Laplacian with the Dirichlet boundary condition. Such a class of nondegenerate potentials is a generalization of many known classes of non-degenerate potentials and will be useful in many problems of nonlinear differential equations. 展开更多
关键词 p-LApLACIAN EIGENVALUE minimization problem Schwarz rearrangement non-degenerate potential boundary value problem
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GENERALIZED p-VALUES FOR TESTING REGRESSION COEFFICIENTS IN PARTIALLY LINEAR MODELS
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作者 Huimin HU Xingzhong XU Guoying LI 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2010年第6期1118-1132,共15页
The one-sided and two-sided hypotheses about the parametric component in partially linear model are considered in this paper. Generalized p-values are proposed based on fiducial method for testing the two hypotheses a... The one-sided and two-sided hypotheses about the parametric component in partially linear model are considered in this paper. Generalized p-values are proposed based on fiducial method for testing the two hypotheses at the presence of nonparametric nuisance parameter. Note that the nonparametric component can be approximated by a linear combination of some known functions, thus, the partially linear model can be approximated by a linear model. Thereby, generalized p-values for a linear model are studied first, and then the results are extended to the situation of partially linear model. Small sample frequency properties are analyzed theoretically. Meanwhile, simulations are conducted to assess the finite sample performance of the tests based on the proposed p-values. 展开更多
关键词 Fiducial inference frequency property generalized p-value hypothesis testing partially linear model.
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The first eigenfunctions and eigenvalue of the p-Laplacian on Finsler manifolds 被引量:1
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作者 YIN SongTing HE Qun 《Science China Mathematics》 SCIE CSCD 2016年第9期1769-1794,共26页
This paper proves that the first eigenfunctions of the Finsler p-Lapalcian are C^(1,α). Using a gradient comparison theorem and one-dimensional model, we obtain the sharp lower bound of the first Neumann and closed e... This paper proves that the first eigenfunctions of the Finsler p-Lapalcian are C^(1,α). Using a gradient comparison theorem and one-dimensional model, we obtain the sharp lower bound of the first Neumann and closed eigenvalue of the p-Laplacian on a compact Finsler manifold with nonnegative weighted Ricci curvature,on which a lower bound of the first Dirichlet eigenvalue of the p-Laplacian is also obtained. 展开更多
关键词 the first eigenvalue p-Laplacian Ricci curvature S curvature
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