期刊文献+
共找到5,132篇文章
< 1 2 250 >
每页显示 20 50 100
SHARP MORREY REGULARITY THEORY FOR A FOURTH ORDER GEOMETRICAL EQUATION
1
作者 向长林 郑高峰 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期420-430,共11页
This paper is a continuation of recent work by Guo-Xiang-Zheng[10].We deduce the sharp Morrey regularity theory for weak solutions to the fourth order nonhomogeneous Lamm-Rivière equation △^{2}u=△(V▽u)+div(w▽... This paper is a continuation of recent work by Guo-Xiang-Zheng[10].We deduce the sharp Morrey regularity theory for weak solutions to the fourth order nonhomogeneous Lamm-Rivière equation △^{2}u=△(V▽u)+div(w▽u)+(▽ω+F)·▽u+f in B^(4),under the smallest regularity assumptions of V,ω,ω,F,where f belongs to some Morrey spaces.This work was motivated by many geometrical problems such as the flow of biharmonic mappings.Our results deepens the Lp type regularity theory of[10],and generalizes the work of Du,Kang and Wang[4]on a second order problem to our fourth order problems. 展开更多
关键词 fourth order elliptic equation regularity theory Morrey space decay estimates Riesz potential
下载PDF
China:In the fourth quarter of 2023,exports of yarn and fabric to ASEAN ceased declining and rebounded
2
《China Textile》 2024年第1期22-23,共2页
On January 8th,the China Chamber of Commerce for Import and Export of Textiles released data showing that in the fourth quarter,China’s textile and clothing exports gradually stabilised.The proportion of intermediate... On January 8th,the China Chamber of Commerce for Import and Export of Textiles released data showing that in the fourth quarter,China’s textile and clothing exports gradually stabilised.The proportion of intermediate exports in textile and clothing exports continued to rise,providing a new impetus for the substantial expansion of exports to traditional markets and international supply chain cooperation. 展开更多
关键词 Export QUARTER fourth
下载PDF
Existence of Monotone Positive Solution for a Fourth-Order Three-Point BVP with Sign-Changing Green’s Function
3
作者 Junrui Yue Yun Zhang Qingyue Bai 《Open Journal of Applied Sciences》 2024年第1期63-69,共7页
This paper is concerned with the following fourth-order three-point boundary value problem , where , we discuss the existence of positive solutions to the above problem by applying to the fixed point theory in cones a... This paper is concerned with the following fourth-order three-point boundary value problem , where , we discuss the existence of positive solutions to the above problem by applying to the fixed point theory in cones and iterative technique. 展开更多
关键词 fourth-Order Three-Point Boundary Value Problem Sign-Changing Green’s Function Fixed Point Index Iterative Technique Monotone Positive Solution EXISTENCE
下载PDF
Fenlong Cultivation-the Fourth Set of Farming Methods Invented in China 被引量:17
4
作者 韦本辉 《Agricultural Science & Technology》 CAS 2017年第11期2045-2048,2052,共5页
The basic theory and effect of the new farming method of "Fenlong" cultivation which has been included in the main extension technology of Ministry of Agriculture of the People's Republic of China is fully illustra... The basic theory and effect of the new farming method of "Fenlong" cultivation which has been included in the main extension technology of Ministry of Agriculture of the People's Republic of China is fully illustrated for the first time, and it is the fourth set (generation) of farming modes and methods following manpower, animal and mechanical (tractor) farming. It follows the natural law to achieve soil activation, water saving, oxygen increase, warming and desalination through the active use of natural resources like soil, rainfall and solar energy, thereby promoting a new round of natural agricultural production and quality improvement and water con- servation, which has crop yield increase by 10%-30%, quality improvement of 5%, natural precipitation retaining increase by100%. The characteristics and mechanism are the use of spiral drill for one-time completion of the land preparation by drilling vertically to 30-50 cm of soil layer through high speed peeling. After instant high temperature and many fierce impacts, mechanical frictions, it could achieve the multiplication of the number of loose soil, soil physical modification and expansion of the soil nutrients, reservoirs, oxygen, microorganisms ("Four pools"). Fenlong cultivation can give birth to new farming culture and civilization, and it can achieve the physical "desalinized" transformation and utilization of saline soil. The formation of Fenlong green farming technology system makes it possible to invent the farming tools of "serf-propelled Fenlong machinery" that has got the patent, and it is the method for farmland (dry land, paddy field) Fenlong cultivation, saline-alkali soil smash-ridging cultivation and for the abundance of grass ecology on degraded grassland. The application of Fenlong "4+1" (arable, saline-alkali soil, grasslands, Sponge City+rivers) green development in China can achieve the "double safety" of food and living space. 展开更多
关键词 Fenlong cultivation The fourth set (generation) of new farming methods Activation and utilization of natural resources Improvement of production and quality Water conservation ecology
下载PDF
ON STABILITY OF SOLUTIONS OF CERTAIN FOURTH-ORDER DELAY DIFFERENTIAL EQUATIONS 被引量:5
5
作者 Cemil Tunc 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第8期1141-1148,共8页
By the use of the Liapunov functional approach, a new result is obtained to ascertain the asymptotic stability of zero solution of a certain fourth-order non-linear differential equation with delay. The established re... By the use of the Liapunov functional approach, a new result is obtained to ascertain the asymptotic stability of zero solution of a certain fourth-order non-linear differential equation with delay. The established result is less restrictive than those reported in the literature. 展开更多
关键词 non-linear delay differential equations of fourth order STABILITY Liapunov functional approach
下载PDF
Stokes'first problem for the fourth order fluid in a porous half space 被引量:4
6
作者 T.Hayat F.Shahazad M.Ayub 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2007年第1期17-21,共5页
In this study, the flow of a fourth order fluid in a porous half space is modeled. By using the modified Darcy's law, the flow over a suddenly moving flat plate is studied numerically. The influence of various parame... In this study, the flow of a fourth order fluid in a porous half space is modeled. By using the modified Darcy's law, the flow over a suddenly moving flat plate is studied numerically. The influence of various parameters of interest on the velocity profile is revealed. 展开更多
关键词 fourth order fluid Porous space Numerical solution Modified Darcy's law
下载PDF
Heat transfer on peristaltic flow of fourth grade fluid in inclined asymmetric channel with partial slip 被引量:2
7
作者 O.U.MEHMOOD N.MUSTAPHA S.SHAFIE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第10期1313-1328,共16页
In this paper, the effects of slip and heat transfer are studied on the peristaltic transport of a magnetohydrodynamic (MHD) fourth grade fluid. The governing equations are modeled and solved under the long waveleng... In this paper, the effects of slip and heat transfer are studied on the peristaltic transport of a magnetohydrodynamic (MHD) fourth grade fluid. The governing equations are modeled and solved under the long wavelength approximation by using a regular perturbation method. Explicit expressions of solutions for the stream function, the velocity, the pressure gradient, the temperature, and the heat transfer coefficient are presented. Pumping and trapping phenomena are analyzed for increasing the slip parameter. Further, the temperature profiles and the heat transfer coefficient are observed for various increasing parameters. It is found that these parameters considerably affect the considered flow characteristics. Comparisons with published results for the no-slip case are found in close agreement. 展开更多
关键词 peristaltic flow fourth grade fluid heat transfer slip condition inclinedchannel
下载PDF
ON THE COEFFICIENTS OF DIFFERENTIATED EXPANSIONS AND DERIVATIVES OF CHEBYSHEV POLYNOMIALS OF THE THIRD AND FOURTH KINDS 被引量:3
8
作者 Eid H.DOHA Waleed M.ABD-ELHAMEED Mahmoud A.BASSUONY 《Acta Mathematica Scientia》 SCIE CSCD 2015年第2期326-338,共13页
Two new analytical formulae expressing explicitly the derivatives of Chebyshev polynomials of the third and fourth kinds of any degree and of any order in terms of Chebyshev polynomials of the third and fourth kinds t... Two new analytical formulae expressing explicitly the derivatives of Chebyshev polynomials of the third and fourth kinds of any degree and of any order in terms of Chebyshev polynomials of the third and fourth kinds themselves are proved. Two other explicit formulae which express the third and fourth kinds Chebyshev expansion coefficients of a general-order derivative of an infinitely differentiable function in terms of their original expansion coefficients are also given. Two new reduction formulae for summing some terminating hypergeometric functions of unit argument are deduced. As an application of how to use Chebyshev polynomials of the third and fourth kinds for solving high-order boundary value problems, two spectral Galerkin numerical solutions of a special linear twelfth-order boundary value problem are given. 展开更多
关键词 Chebyshev polynomials of the third and fourth kinds expansion coefficients generalized hypergeometric functions boundary value problems
下载PDF
MULTIPLICITY RESULTS FOR FOURTH ORDER ELLIPTIC EQUATIONS OF KIRCHHOFF-TYPE 被引量:3
9
作者 许丽萍 陈海波 《Acta Mathematica Scientia》 SCIE CSCD 2015年第5期1067-1076,共10页
In this paper, we concern with the following fourth order elliptic equations of Kirchhoff type {Δ^2u-(a+bfR^3|↓△u|^2dx)△u+V(x)u=f(x,u),x∈R^3, u∈H^2(R3),where a, b 〉 0 are constants and the primitive... In this paper, we concern with the following fourth order elliptic equations of Kirchhoff type {Δ^2u-(a+bfR^3|↓△u|^2dx)△u+V(x)u=f(x,u),x∈R^3, u∈H^2(R3),where a, b 〉 0 are constants and the primitive of the nonlinearity f is of superlinear growth near infinity in u and is also allowed to be sign-changing. By using variational methods, we establish the existence and multiplicity of solutions. Our conditions weaken the Ambrosetti- Rabinowitz type condition. 展开更多
关键词 fourth order elliptic equations of Kirchhoff type symmetric mountain pass theorem variational methods
下载PDF
Thermophoresis and concentration effects in a fourth grade peristaltic flow with convective walls 被引量:1
10
作者 Ali Aamir Asghar S Awais M 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第7期1654-1662,共9页
In this investigation,we have studied the peristaltic fluid flow in an asymmetric channel with convective walls.Fourth grade fluid model has been utilized in view of the fact that the results of all other differential... In this investigation,we have studied the peristaltic fluid flow in an asymmetric channel with convective walls.Fourth grade fluid model has been utilized in view of the fact that the results of all other differential type models can be deduced as the special case.Combined effects of heat and mass transfer are considered.The thermophoresis effects occur in the energy equation.Convective heat and mass boundary conditions have been given special attention.Long wave length and low Reynolds number approximations are utilized for the simplifications.Approximate analytic solutions for the velocity,temperature and concentration profiles are calculated using perturbation technique and elaborated in the form of graphical observations for various physical quantities. 展开更多
关键词 fourth GRADE fluid CONVECTIVE boundary conditions pumping and TRAPPING PERISTALSIS
下载PDF
ON THE BOUNDEDNESS AND THE STABILITY RESULTS FOR THE SOLUTION OF CERTAIN FOURTH ORDER DIFFERENTIAL EQUATIONS VIA THE INTRINSIC METHOD 被引量:1
11
作者 Cemil TUNC Aydin TIRYAKI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第11期1039-1049,共11页
In this paper, we first present constructing a Lyapunov function for (1. 1) and then we show the asymptotic stability in the large of the trivial solution x=0 for case p≡ 0,and the boundedness result of the sol... In this paper, we first present constructing a Lyapunov function for (1. 1) and then we show the asymptotic stability in the large of the trivial solution x=0 for case p≡ 0,and the boundedness result of the solutions of (1 .1 ) for case p≠0. These results improve sveral well-known results. 展开更多
关键词 nonlinear differential equations of the fourth order Lyapunovfunction STABILITY BOUNDEDNESS intrinsic method
下载PDF
Effects of the fourth component and undercooling on morphology of primary Mg-Zn-Y icosahedral quasicrystal phase under normal casting conditions 被引量:2
12
作者 Wang Zhifeng Zhao Weimin +2 位作者 Bo-Young Hur Huang Chunying Yu Chengquan 《China Foundry》 SCIE CAS 2009年第4期293-299,共7页
The paper presents some results of the investigation on effects of the fourth component(Ti,C,Sb or Cu)and undercooling on the morphology,size and forming process of primary Mg-Zn-Y icosahedral quasicrystal phase(I-pha... The paper presents some results of the investigation on effects of the fourth component(Ti,C,Sb or Cu)and undercooling on the morphology,size and forming process of primary Mg-Zn-Y icosahedral quasicrystal phase(I-phase)under normal casting conditions.The result shows that the addition of certain amount of fourth component can transform I-phase morphology from petal-like to spherical.However,I-phase will grow up to petal-like if superfluous addition of the fourth component applied.It is also found that the solidified morphology of I-phase depends on the stability of spherical I-phase during the subsequent growth,and critical radius of maintaining the spherical I-phase interface relatively stable.Further,mini-sized spherical I-phase can be produced with high content of the fourth component by undercooling.Such findings are beneficial for industrializing Mgbased quasicrystals. 展开更多
关键词 magnesium alloy QUASICRYSTAL fourth component MORPHOLOGY degree of undercooling
下载PDF
Comparison of Kurtosis and Fourth Power Detectors with Applications to IR-UWB OOK Systems 被引量:1
13
作者 Javad Taghipour Vahid Tabataba Vakili Dariush Abbasi-Moghadam 《International Journal of Communications, Network and System Sciences》 2012年第1期43-49,共7页
On-off keying (OOK) is one of the modulation schemes for non-coherent impulse radio Ultra-wideband systems. In this paper, the utilization of the kurtosis detector (KD) and fourth power detector (FD) receivers for OOK... On-off keying (OOK) is one of the modulation schemes for non-coherent impulse radio Ultra-wideband systems. In this paper, the utilization of the kurtosis detector (KD) and fourth power detector (FD) receivers for OOK signaling is introduced. We investigate the effect of integration interval and the optimum threshold on the performance of energy detector (ED), KD and FD receivers. The semi analytic expression of BER is obtained by using generalized extreme value distribution function for KD and FD receivers. From performance point of view, the simulation results show that FD receiver outperforms KD and ED receivers. In contrast, the sensitivity to the optimum threshold is greatly reduced in KD receiver compared to ED and FD receivers. 展开更多
关键词 Ultra-Wideband (UWB) NON-COHERENT Receiver OOK Energy DETECTOR KURTOSIS DETECTOR fourth Power DETECTOR
下载PDF
Effective administration of cranial drilling therapy in the treatment of fourth degree temporal,facial and upper limb burns at high altitude:A case report 被引量:2
14
作者 Cong-Mo Shen Yi Li +1 位作者 Zhou Liu Yong-Zhang Qi 《World Journal of Clinical Cases》 SCIE 2020年第20期5062-5069,共8页
BACKGROUND Fourth degree burns damage the full thickness of the skin and affect underlying tissues.Skin grafting after debridement is often used to cover the wounds of salvageable severe burns.A granulation wound can ... BACKGROUND Fourth degree burns damage the full thickness of the skin and affect underlying tissues.Skin grafting after debridement is often used to cover the wounds of salvageable severe burns.A granulation wound can be formed by drilling the skull to the barrier layer to solve the problem of skull exposure.Low oxygen levels present at high altitudes aggravate ischemia and hypoxia which can negatively impact wound healing.The impaired healing in such cases can be ameliorated by hyperbaric oxygen therapy.CASE SUMMARY We describe a patient who presented with fourth degree burns to the left temporal and facial regions upon admission in December 2018.The periosteum of the skull and the deep fascia of the face were exposed.After the first stage of debridement and skin grafting,the temporal skin did not survive well.Granulation was induced by cranial drilling,and then a local flap was transferred to cover the wound.The left temporal and facial wounds were completely covered and the patient recovered well.CONCLUSION Skin grafting and flap transfer after early debridement to cover the wound and control infection were of great significance.In the later stages of the patient's treatment,survival of the skin graft and skin flap was observed.The second stage repair was performed to achieve successful skin grafting by cranial granulation.Granulation was formed by drilling the skull,and then the wound was closed,which is suitable for cases with skull exposure and wounds with poor blood supply.We consider that hyperbaric oxygen treatment and improving tissue oxygen supply were beneficial in this patient. 展开更多
关键词 fourth degree burn Skull exposure Chronic wounds Cranial drilling therapy High altitude area Case report
下载PDF
Hybrid Effects of Thermal and Concentration Convection on Peristaltic Flow of Fourth Grade Nanofluids in an Inclined Tapered Channel: Applications of Double-Diffusivity 被引量:2
15
作者 Safia Akram Alia Razia 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第6期901-922,共22页
This article brings into focus the hybrid effects of thermal and concentration convection on peristaltic pumping of fourth grade nanofluids in an inclined tapered channel.First,the brief mathematical modelling of the ... This article brings into focus the hybrid effects of thermal and concentration convection on peristaltic pumping of fourth grade nanofluids in an inclined tapered channel.First,the brief mathematical modelling of the fourth grade nanofluids is provided along with thermal and concentration convection.The Lubrication method is used to simplify the partial differential equations which are tremendously nonlinear.Further,analytical technique is applied to solve the differential equations that are strongly nonlinear in nature,and exact solutions of temperature,volume fraction of nanoparticles,and concentration are studied.Numerical and graphical findings manifest the influence of various physical flow-quantity parameters.It is observed that the nanoparticle fraction decreases because of the increasing values of Brownian motion parameter and Dufour parameter,whereas the behaviour of nanoparticle fraction is quite opposite for thermophoresis parameter.It is also noted that the temperature profile decreases with increasing Brownian motion parameter values and rises with Dufour parameter values.Moreover,the concentration profile ascends with increasing thermophoresis parameter and Soret parameter values. 展开更多
关键词 Nanofluids thermal and concentration convection peristaltic flow inclined tapered channel fourth grade fluid
下载PDF
Fourth Industrial Revolution:Technological Drivers,Impacts and Coping Methods 被引量:6
16
作者 LI Guoping HOU Yun WU Aizhi 《Chinese Geographical Science》 SCIE CSCD 2017年第4期626-637,共12页
The world is marching into a new development period when the digital technology,physical technology,and biological technology have achieved an unprecedented development respectively in their own fields,and at the same... The world is marching into a new development period when the digital technology,physical technology,and biological technology have achieved an unprecedented development respectively in their own fields,and at the same time their applications are converging greatly.These are the three major technological drivers for the Fourth Industrial Revolution.This paper discusses the specific technology niches of each kind technological driver behind the Fourth Industrial Revolution,and then evaluates impacts of the Fourth Industrial Revolution on global industrial,economic,and social development.At last this paper proposes possible measures and policies for both firms and governments to cope with the changes brought by the Fourth Industrial Revolution. 展开更多
关键词 fourth Industrial Revolution technological drivers global impacts firm-level adjustments government policies
下载PDF
Hyperbolic Fibonacci and Lucas Functions, “Golden” Fibonacci Goniometry, Bodnar’s Geometry, and Hilbert’s Fourth Problem—Part III. An Original Solution of Hilbert’s Fourth Problem 被引量:3
17
作者 Alexey Stakhov Samuil Aranson 《Applied Mathematics》 2011年第3期283-293,共11页
This article refers to the “Mathematics of Harmony” by Alexey Stakhov [1], a new interdisciplinary direction of modern science. The main goal of the article is to describe two modern scientific discoveries—New Geom... This article refers to the “Mathematics of Harmony” by Alexey Stakhov [1], a new interdisciplinary direction of modern science. The main goal of the article is to describe two modern scientific discoveries—New Geometric Theory of Phyl-lotaxis (Bodnar’s Geometry) and Hilbert’s Fourth Problem based on the Hyperbolic Fibonacci and Lucas Functions and “Golden” Fibonacci -Goniometry ( is a given positive real number). Although these discoveries refer to different areas of science (mathematics and theoretical botany), however they are based on one and the same scien-tific ideas—The “golden mean,” which had been introduced by Euclid in his Elements, and its generalization—The “metallic means,” which have been studied recently by Argentinian mathematician Vera Spinadel. The article is a confirmation of interdisciplinary character of the “Mathematics of Harmony”, which originates from Euclid’s Elements. 展开更多
关键词 Euclid’s Fifth Postulate Lobachevski’s GEOMETRY HYPERBOLIC GEOMETRY Phyllotaxis Bodnar’s GEOMETRY Hilbert’s fourth Problem the “Golden” and “Metallic” Means Binet Formulas HYPERBOLIC FIBONACCI and Lucas Functions Gazale Formulas “Golden” FIBONACCI -Goniometry
下载PDF
May Fourth Movement in China-language Planning and Innovation
18
作者 范丽颖 程静 《海外英语》 2015年第10期201-202,共2页
The purpose of this paper is to establish a clear comprehension and discernment of fundamental concepts of the languageplanning field and its correlation with and differences from innovation and change.It focuses on f... The purpose of this paper is to establish a clear comprehension and discernment of fundamental concepts of the languageplanning field and its correlation with and differences from innovation and change.It focuses on five aspects:a new language policyadopted in the period of late Qing;the status of classic Chinese in ancient times and the new vernacular in modern Chinese;the ori-gins of new vernacular;the problem that appeared alongside the new vernacularand the influence of May Fourth Movement in soci-ety and in education area. 展开更多
关键词 MAY fourth MOVEMENT LANGUAGE PLANNING LANGUAGE policy status PLANNING CORPUS PLANNING
下载PDF
The Energy-orthogonal Tetrahedral Finite Element for Fourth Order Elliptic Equations 被引量:1
19
作者 LIU Ming-fang CAO Ji-wei CHEN Shao-chun 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第3期388-393,共6页
In this paper,the 16-parameter nonconforming tetrahedral element which has an energy-orthogonal shape function space is presented for the discretization of fourth order elliptic partial differential operators in three... In this paper,the 16-parameter nonconforming tetrahedral element which has an energy-orthogonal shape function space is presented for the discretization of fourth order elliptic partial differential operators in three spatial dimensions.The newly constructed element is proved to be convergent for a model biharmonic equation. 展开更多
关键词 nonconforming finite element tree-dimension fourth order elliptic equation
下载PDF
Turiyam Set a Fourth Dimension Data Representation 被引量:1
20
作者 Prem Kumar Singh 《Journal of Applied Mathematics and Physics》 2021年第7期1821-1828,共8页
<div style="text-align:justify;"> Recently most of the authors focused on dealing with uncertainty. To deal with that algebra of fuzzy sets is introduced in three-way fuzzy space. It gave way to charac... <div style="text-align:justify;"> Recently most of the authors focused on dealing with uncertainty. To deal with that algebra of fuzzy sets is introduced in three-way fuzzy space. It gave way to characterize the attributes in true, false or uncertain regions. It is found in chemistry also as an electron, proton and neutron. The problem arises when the attributes are beyond the three-dimensions. One of suitable examples is winning, draw or loss of a match cannot define the win draw or loss of series. It is measured in international relationships also like USA-China, USA-Russia, India-Pakistan or Israel-Philistine. Some countries support the USA, some countries support China, some countries are neutral in hidden consciousness to fulfill their agenda. It is also measured in democratic countries like India where some people vote in favor of a party, some people vote against the given party, some people may be absent or walkout whereas some people vote NOTA. This last dimension is called as Turiyam or fourth dimension. This last dimension is influenced from Yin-Yang theory of Chinese Taoism as well as Sanskrit Yamma-Yammi and its complement. The Turiya means measuring each dimension in silent mode. There is less attention paid towards the necessity of fourth dimensions and its algebra. This paper will discuss gimbal lock of three-way fuzzy space using the Tuiyam set and its algebra. </div> 展开更多
关键词 fourth Dimensions Plithogenic Set Three-Way Decision Space Turiyam Set GRANULATION
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部