期刊文献+
共找到4,245篇文章
< 1 2 213 >
每页显示 20 50 100
Effects of Continuous Cropping of Polygonatum odoratum on Microbial Functional Diversity and Selected Environmental Factors in the Rhizosphere Soil
1
作者 Manjiang YU Yihong HU +3 位作者 Fan XIE Xiongmei ZHU Chenzhong JIN Jing YE 《Agricultural Biotechnology》 2025年第5期12-18,21,共8页
[Objectives]This study was conducted to investigate the mechanism of continuous cropping obstacles in Polygonatum odoratum.[Methods]Three treatments were established:continuous cropping(two consecutive crops),first-cr... [Objectives]This study was conducted to investigate the mechanism of continuous cropping obstacles in Polygonatum odoratum.[Methods]Three treatments were established:continuous cropping(two consecutive crops),first-crop control(with Phaseolus vulgaris as the preceding crop),and blank control.The effects of continuous cropping on the functional diversity of soil microorganisms,soil enzyme activities,and soil nutrient coordination in the rhizosphere soil of P.odoratum during different growth stages were investigated.[Results](1)Continuous cropping increased the carbon source metabolic capacity,Shannon diversity index,and richness of rhizosphere soil microorganisms by 3.2%-14.7%,0.9%-3.5%,and 1.3%-12.5%,respectively,but the differences were not significant.(2)Principal component analysis indicated that during the middle stage of rhizome expansion,continuous cropping significantly altered the characteristics of microbial carbon metabolism,and the microbial communities utilizing carbohydrates,amino acids,polymers,carboxylic acids and amines as carbon sources exhibited vigorous metabolism.(3)Continuous cropping significantly reduced the activities of urease,polyphenol oxidase,and acid phosphatase in rhizosphere soil,with decreases of 24.4%-39.5%,3.2%-14.8%,and 7.9%-18.2%,respectively.The activities of catalase and invertase sometimes exceeded and sometimes fell below those of the first crop,showing no consistent pattern.(4)Under continuous cropping conditions,nutrient imbalance occurred in the rhizosphere soil,characterized by nitrogen deficiency and phosphorus surplus.(5)Grey correlation analysis indicated that available phosphorus content,alkali-hydrolyzable nitrogen content and polyphenol oxidase activity in rhizosphere soil were the main factors influencing microbial functional diversity.[Conclusions]This study provides a theoretical basis for understanding the formation mechanism of continuous cropping obstacles in P.odoratum. 展开更多
关键词 Polygonatum odoratum continuous cropping Rhizosphere soil Microbial function
在线阅读 下载PDF
The Effect of Continuous Positive Airway Pressure Therapy on Daytime Sleepiness and Cognitive Function in Patients with Moderate to Severe OSAHS
2
作者 Juan Du Yinping Wang +2 位作者 Long Zhang Rui Lu Ming Cui 《Science International Innovative Medicine》 2025年第3期17-22,共6页
Objective:To explore the effect of continuous positive airway pressure(CPAP)therapy on daytime sleepiness and cognitive function in patients with moderate to severe obstructive sleep apnea-hypopnea syndrome(OSAHS).Met... Objective:To explore the effect of continuous positive airway pressure(CPAP)therapy on daytime sleepiness and cognitive function in patients with moderate to severe obstructive sleep apnea-hypopnea syndrome(OSAHS).Methods:From January to December 2024,60 patients with moderate to severe OSAHS were enrolled and randomly divided into an observation group and a control group,with 30 patients in each group.The observation group received CPAP combined with routine intervention,while the control group only received routine intervention,with a course of 3 months for both groups.Results:After 3 months of intervention,the observation group showed significantly better improvements in the frequency and duration of daytime sleepiness as well as all dimensions of cognitive function compared with the control group,and the differences were statistically significant(P<0.05).Conclusion:CPAP therapy can effectively relieve daytime sleepiness in patients with moderate to severe OSAHS,and significantly improve memory,attention and logical thinking ability.The comprehensive intervention effect is superior to simple routine management. 展开更多
关键词 continuous Positive Airway Pressure Obstructive Sleep Apnea-Hypopnea Syndrome Daytime Sleepiness Cognitive function Sleep Quality
暂未订购
CONSTRUCTION OF SOME KIESSWETTER-LIKE FUNCTIONS-THE CONTINUOUS BUT NON-DIFFERENT-IABLE FUNCTION DEFINED BY QUINARY DECIMAL 被引量:1
3
作者 TieYong YangGuangjun 《Analysis in Theory and Applications》 2004年第1期58-68,共11页
In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of ... In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of graphs of these functions and give a detailed proof. 展开更多
关键词 Kiesswetter-like functions continuous but non-differentiable quinary decimal iterated function system inequality Hausdorff dimension
在线阅读 下载PDF
On the Method of Multiplier-enlargement and Approximation of Unbounded Continuous Functions 被引量:1
4
作者 郑成德 王仁宏 《Northeastern Mathematical Journal》 CSCD 2001年第2期231-235,共5页
By combining the classical appropriate functions “1, x, x 2” with the method of multiplier enlargement, this paper establishes a theorem to approximate any unbounded continuous functions with modified positive... By combining the classical appropriate functions “1, x, x 2” with the method of multiplier enlargement, this paper establishes a theorem to approximate any unbounded continuous functions with modified positive linear operators. As an example, Hermite Fejér interpolation polynomial operators are analysed and studied, and a general conclusion is obtained. 展开更多
关键词 positive linear operator approximation of unbounded continuous function method of multiplier enlargement Hermite Fejér interpolation polynomial operator
在线阅读 下载PDF
Cylindrical Guided Wave Signals for Underground Pipe Inspection using Different Continuous Wavelet Mother Functions 被引量:1
5
作者 Rais Ahmad Tribikram Kundu 《Journal of Civil Engineering and Architecture》 2011年第12期1103-1110,共8页
Over the past decade, wavelets provided a powerful and flexible set of tools for handling fundamental problems in science and engineering. Wavelet analyses are being used for solving problems in different engineering ... Over the past decade, wavelets provided a powerful and flexible set of tools for handling fundamental problems in science and engineering. Wavelet analyses are being used for solving problems in different engineering areas like audio de-noising, signal compression, object detection, image decomposition, speech recognition etc. Wavelet analysis employs orthonormal as well as non-orthonornal functions. This research investigates the effectiveness of wavelet analysis in detecting defects in underground steel pipe networks. Continuous Wavelet Transforms (CWT) has been performed on the received signals of cylindrical guided waves. Cylindrical Guided waves are generated and propagated through the pipe wall boundaries in a pitch-catch system. Piezo-electric transducers are used to generate as well as receive guided waves. Several mother wavelet functions such as Daubechies, Symlet, Coiflet and Meyer have been used for the Continuous Wavelet Transform to investigate the most suitable function for defect detection. This research also investigates the effect of surrounding soil on wavelet transforms for different mother wavelet functions. 展开更多
关键词 Wavelet analysis guided waves mother wavelet functions continuous wavelet transform.
在线阅读 下载PDF
Dynamic Systems of Shifts in the Space of Piece-Wise Continuous Functions
6
作者 Isaac Kwame Dontwi William Obeng-Denteh 《Advances in Pure Mathematics》 2012年第6期446-449,共4页
In this paper we embark on the study of Dynamic Systems of Shifts in the space of piece-wise continuous functions analogue to the known Bebutov system. We give a formal definition of a topological dynamic system in th... In this paper we embark on the study of Dynamic Systems of Shifts in the space of piece-wise continuous functions analogue to the known Bebutov system. We give a formal definition of a topological dynamic system in the space of piece-wise continuous functions and show, by way of an example, stability in the sense of Poisson discontinuous function. We prove that a fixed discontinuous function, f, is discontinuous for all its shifts, whereas the trajectory of discontinuous function is not a compact set. 展开更多
关键词 Dynamic System SHIFTS PIECEWISE continuous functions Compact Sets POISSON DIScontinuous function
在线阅读 下载PDF
CONTINUOUS SELECTIONS OF THE SET-VALUED METRIC GENERALIZED INVERSE IN 2-STRICTLY CONVEX BANACH SPACES
7
作者 Shaoqiang SHANG 《Acta Mathematica Scientia》 SCIE CSCD 2022年第3期1225-1237,共13页
In this paper,we prove that if X is an almost convex and 2-strictly convex space,linear operator T:X→Y is bounded,N(T)is an approximative compact Chebyshev subspace of X and R(T)is a 3-Chebyshev hyperplane,then there... In this paper,we prove that if X is an almost convex and 2-strictly convex space,linear operator T:X→Y is bounded,N(T)is an approximative compact Chebyshev subspace of X and R(T)is a 3-Chebyshev hyperplane,then there exists a homogeneous selection T^(σ)of T^(■)such that continuous points of T^(σ)and T^(■)are dense on Y. 展开更多
关键词 continuous selection 3-Chebyshev hyperplane set-valued metric generalized inverses 2-strictly convex space
在线阅读 下载PDF
A Note on Discontinuous Functions with Continuous Second Iterate
8
作者 Pingping Zhang Xiaobing Gong 《Journal of Applied Mathematics and Physics》 2015年第6期691-696,共6页
This paper investigates four classes of functions with a single discontinuous point. We give the sufficient and necessary conditions under which the second order iterates are continuous functions. Furthermore, the suf... This paper investigates four classes of functions with a single discontinuous point. We give the sufficient and necessary conditions under which the second order iterates are continuous functions. Furthermore, the sufficient conditions for the continuity of the even order iterates with finitely many discontinuous points are obtained. 展开更多
关键词 ITERATION DIScontinuous POINT continuous function
在线阅读 下载PDF
On Continuous Programming with Support Functions
9
作者 Iqbal Husain Santosh K. Shrivastav Abdul Raoof Shah 《Applied Mathematics》 2013年第10期1441-1449,共9页
A second-order Mond-Weir type dual problem is formulated for a class of continuous programming problems in which both objective and constraint functions contain support functions;hence it is nondifferentiable. Under s... A second-order Mond-Weir type dual problem is formulated for a class of continuous programming problems in which both objective and constraint functions contain support functions;hence it is nondifferentiable. Under second-order strict pseudoinvexity, second-order pseudoinvexity and second-order quasi-invexity assumptions on functionals, weak, strong, strict converse and converse duality theorems are established for this pair of dual continuous programming problems. Special cases are deduced and a pair of dual continuous problems with natural boundary values is constructed. A close relationship between the duality results of our problems and those of the corresponding (static) nonlinear programming problem with support functions is briefly outlined. 展开更多
关键词 continuous PROGRAMMING SECOND-ORDER Generalized INVEXITY SECOND-ORDER DUALITY Nonlinear PROGRAMMING Support functions Natural BOUNDARY VALUES
在线阅读 下载PDF
Second-Order Duality for Continuous Programming Containing Support Functions
10
作者 Iqbal Husain Mashoob Masoodi 《Applied Mathematics》 2010年第6期534-541,共8页
A second-order dual problem is formulated for a class of continuous programming problem in which both objective and constrained functions contain support functions, hence it is nondifferentiable. Under second-order in... A second-order dual problem is formulated for a class of continuous programming problem in which both objective and constrained functions contain support functions, hence it is nondifferentiable. Under second-order invexity and second-order pseudoinvexity, weak, strong and converse duality theorems are established for this pair of dual problems. Special cases are deduced and a pair of dual continuous problems with natural boundary values is constructed. A close relationship between duality results of our problems and those of the corresponding (static) nonlinear programming problem with support functions is briefly outlined. 展开更多
关键词 continuous PROGRAMMING SECOND-ORDER INVEXITY SECOND-ORDER PSEUDOINVEXITY SECOND-ORDER DUALITY Nonlinear PROGRAMMING Support functions Natural Boundary VALUES
在线阅读 下载PDF
Gap Functions and Error Bounds for Set-Valued Vector Quasi Variational Inequality Problems
11
作者 Rachana Gupta Aparna Mehra 《Applied Mathematics》 2017年第12期1903-1917,共15页
One of the classical approaches in the analysis of a variational inequality problem is to transform it into an equivalent optimization problem via the notion of gap function. The gap functions are useful tools in deri... One of the classical approaches in the analysis of a variational inequality problem is to transform it into an equivalent optimization problem via the notion of gap function. The gap functions are useful tools in deriving the error bounds which provide an estimated distance between a specific point and the exact solution of variational inequality problem. In this paper, we follow a similar approach for set-valued vector quasi variational inequality problems and define the gap functions based on scalarization scheme as well as the one with no scalar parameter. The error bounds results are obtained under fixed point symmetric and locally α-Holder assumptions on the set-valued map describing the domain of solution space of a set-valued vector quasi variational inequality problem. 展开更多
关键词 set-valued VECTOR QUASI Variational Inequality Problem GAP function Regularized GAP function Error Bounds Fixed Point Symmetric MAP α-Holder MAP
在线阅读 下载PDF
Inverse Limit of Spaces of Upper Semicontinuous Functions
12
作者 张德学 《Northeastern Mathematical Journal》 CSCD 2001年第1期49-52,共4页
Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor o... Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor on compact Hausdorff space. It is proved in this note that this functor preserves inverse limits. 展开更多
关键词 upper semicontinuous function continuous lattice lim inf convergence inverse limit
在线阅读 下载PDF
On Approximation of Nonbounded Continuous Functions
13
作者 ZHENGCheng-de WANGRen-hong 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第1期44-48,共5页
This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are ... This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are analysed and studied. This paper gives a certain theorem as a general rule to approximate any nonbounded continuous functions. 展开更多
关键词 positive linear operator approximation of nonbounded continuous function method of multiplier-enlargement Bernstein polynomial operator
在线阅读 下载PDF
APPROXIMATION OF CONTINUOUS FUNCTIONS BY GENERALIZED KARAMATA MEANS
14
作者 S.A.SETTU 《Analysis in Theory and Applications》 1994年第1期88-98,共11页
A sufficient condition for the order of approximation of a continuous 2π periodic function with a given majorant for the modulus of continuity by the [F, d_n] means of its Fourier serier to be of Jackson order is obt... A sufficient condition for the order of approximation of a continuous 2π periodic function with a given majorant for the modulus of continuity by the [F, d_n] means of its Fourier serier to be of Jackson order is obtained. This sufficient condition is shown to be not enough for the order of approximation by partial sums of their Fourier series to be of Jackson order. The error estimate is shown to be the best possible. 展开更多
关键词 exp APPROXIMATION OF continuous functions BY GENERALIZED KARAMATA MEANS
在线阅读 下载PDF
Uniformly Bounded Set-Valued Composition Operators in the Spaces of Functions of Bounded Variation in the Sense of Riesz
15
作者 Wadie Aziz Nelson Merentes 《International Journal of Modern Nonlinear Theory and Application》 2015年第4期226-233,共8页
We show that the lateral regularizations of the generator of any uniformly bounded set-valued composition Nemytskij operator acting in the spaces of functions of bounded variation in the sense of Riesz, with nonempty ... We show that the lateral regularizations of the generator of any uniformly bounded set-valued composition Nemytskij operator acting in the spaces of functions of bounded variation in the sense of Riesz, with nonempty bounded closed and convex values, are an affine function. 展开更多
关键词 j-Variation in the SENSE of RIESZ set-valued functions Left and Right Regularizations UNIFORMLY BOUNDED OPERATOR Composition (Nemytskij) OPERATOR Jensen Equation
在线阅读 下载PDF
Fuzzy φψ-continuous Functions between L-topological Spaces(Ⅰ)
16
作者 Bayaz Daraby 《模糊系统与数学》 CSCD 北大核心 2009年第3期90-94,共5页
In the present paper,φψ-continuous function on L-topological spaces and productive operation are defined.By means of this operation,we study fuzzy φψ-continuity from L-product spaces into L-product spaces and also... In the present paper,φψ-continuous function on L-topological spaces and productive operation are defined.By means of this operation,we study fuzzy φψ-continuity from L-product spaces into L-product spaces and also from L-topological spaces into L-product spaces. 展开更多
关键词 模糊数学 模糊集 理论 发展
在线阅读 下载PDF
Fuzzy φψ-continuous Functions between L-topological Spaces(Ⅱ)
17
作者 Bayaz Daraby 《模糊系统与数学》 CSCD 北大核心 2009年第5期125-129,共5页
In the present paper,sum operation on sum spaces of a family of L-topological spaces is defined. Fuzzy φψ-continuity from sum spaces of a family of L-topological spaces into L-product spaces and from sum spaces of a... In the present paper,sum operation on sum spaces of a family of L-topological spaces is defined. Fuzzy φψ-continuity from sum spaces of a family of L-topological spaces into L-product spaces and from sum spaces of a family of L-topological spaces into L-topological spaces are investigated. 展开更多
关键词 模糊数学 理论 模糊系统 系统论
在线阅读 下载PDF
Sub-Differential Characterizations of Non-Smooth Lower Semi-Continuous Pseudo-Convex Functions on Real Banach Spaces
18
作者 Akachukwu Offia Ugochukwu Osisiogu +4 位作者 Theresa Efor Friday Oyakhire Monday Ekhator Friday Nkume Sunday Aloke 《Open Journal of Optimization》 2023年第3期99-108,共10页
In this paper, we characterize lower semi-continuous pseudo-convex functions f : X → R ∪ {+ ∞} on convex subset of real Banach spaces K  ⊂ X with respect to the pseudo-monotonicity of its Clarke-Rockafellar Su... In this paper, we characterize lower semi-continuous pseudo-convex functions f : X → R ∪ {+ ∞} on convex subset of real Banach spaces K  ⊂ X with respect to the pseudo-monotonicity of its Clarke-Rockafellar Sub-differential. We extend the results on the characterizations of non-smooth convex functions f : X → R ∪ {+ ∞} on convex subset of real Banach spaces K  ⊂ X with respect to the monotonicity of its sub-differentials to the lower semi-continuous pseudo-convex functions on real Banach spaces. 展开更多
关键词 Real Banach Spaces Pseudo-Convex functions Pseudo-Monotone Maps Sub-Differentials Lower Semi-continuous functions and Approximate Mean Value Inequality
在线阅读 下载PDF
Effect of continuous nursing combined with respiratory exercise nursing on pulmonary function of postoperative patients with lung cancer 被引量:9
19
作者 Qiong-Xiang Qiu Wen-Juan Li +1 位作者 Xi-Miao Ma Xue-Hua Feng 《World Journal of Clinical Cases》 SCIE 2023年第6期1330-1340,共11页
BACKGROUND Lung cancer is a malignant tumor with high morbidity and mortality among cancers.Surgery is currently one of the primary methods of treating lung cancer.Although it can slow down the progression of the dise... BACKGROUND Lung cancer is a malignant tumor with high morbidity and mortality among cancers.Surgery is currently one of the primary methods of treating lung cancer.Although it can slow down the progression of the disease by removing the lesion,this invasive surgery inevitably damages the integrity of the patient’s chest.Moreover,the patient’s pulmonary function may have a low compensatory capacity after surgery,causing various respiratory diseases such as atelectasis,respiratory function decline,and even serious cardiovascular disease.All of these have great negative impacts on the surgical effect and the prognosis of patients.With the continuous exploration and development of nursing,continuous nursing and respiratory exercise nursing have been gradually applied in the nursing of patients after lung cancer surgery,and have achieved good nursing results.AIM To investigate the effect of continuous nursing combined with respiratory exercise nursing on the pulmonary function of postoperative patients with lung cancer.METHODS A total of 80 patients with lung cancer who underwent surgery in our hospital from January 2021 to December 2021 were selected as the study subjects.All subjects were randomly divided into the control group(n=40 cases)and the experimental group(n=40 cases).Patients with lung cancer in the control group were given conventional nursing after surgery,while the experimental group was given continuous nursing combined with respiratory exercise nursing based on conventional nursing.The recovery of pulmonary function and respiratory symptoms was observed before and after 3 mo of intervention in both groups.The pulmonary function parameters,blood gas analysis,MD Anderson Symptom Inventory-lung cancer module(MDASI-LC)scores,incidence of pulmonary complications,and Morisky compliance scores were compared between the two groups before and after 3 mo of intervention.RESULTS There was no significant difference in pulmonary function and blood gas analysis between the two groups before intervention(P>0.05).3 mo after the intervention,the pulmonary function parameters in the experimental group(SpO2,VC,MVV,FEV1,FEV1%pred,and FEV1/FVC)were higher than those in the control group,and the differences were statistically significant(P<0.05).There was no significant difference in blood gas analysis between the two groups before intervention(P>0.05).PaO2 in the experimental group was significantly higher than that in the control group,and PaCO_(2) was significantly lower than that in the control group 3 mo after the intervention.The difference had statistical significance(P<0.05).3 mo after the intervention,the MDASI score of respiratory symptoms in the experimental group was significantly lower than that in the control group(P<0.05),and the incidence of pulmonary complications was lower than that in the control group(P<0.05).In addition,the treatment compliance and nursing satisfaction of patients in the experimental group were higher than those in the control group,and the differences were statistically significant(P<0.05).CONCLUSION Continuous nursing combined with respiratory exercise nursing can significantly accelerate the recovery of respiratory function in postoperative lung cancer patients,reduce the incidence of postoperative complications of lung cancer as well as improve the treatment compliance of patients. 展开更多
关键词 Postoperative lung cancer continuous nursing Respiratory exercise nursing Pulmonary function
暂未订购
Nonsingle-valley Continuous Solutions of p-order Feigenbaum's Functional Equation 被引量:2
20
作者 张爱华 王立娟 宋威 《Northeastern Mathematical Journal》 CSCD 2003年第4期375-380,共6页
The author considers the Feigenbaum's functional equation fp(λx) = λf(x) for each p > 2. The existence of nonsingle-valley continuous solutions to this equation is discussed and a feasible method to construct... The author considers the Feigenbaum's functional equation fp(λx) = λf(x) for each p > 2. The existence of nonsingle-valley continuous solutions to this equation is discussed and a feasible method to construct such solutions is given. 展开更多
关键词 functional equation single-valley continuous solution nonsingle-valley continuous solution
在线阅读 下载PDF
上一页 1 2 213 下一页 到第
使用帮助 返回顶部