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Search Results: 1 - 10 of 116228 matches for " Ji Zhang "
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The Series of Reciprocals of Non-central Binomial Coefficients  [PDF]
Laiping Zhang, Wanhui Ji
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.33B006
Abstract:

Utilizing Gamma-Beta function, we can build one series involving reciprocal of non-central binomial coefficients, then We can structure several new series of reciprocals of non-central binomial coefficients by item splitting, these new created denominator of series contain 1 to 4 odd factors of binomial coefficients. As the result of splitting items, some identities of series of numbers values of reciprocals of binomial coefficients are given. The method of splitting terms offered in this paper is a new combinatorial analysis way and elementary method to create new series.

Lyapunov Function and Exponential Trichotomy on Time Scales
Ji Zhang
Discrete Dynamics in Nature and Society , 2011, DOI: 10.1155/2011/958381
Abstract: We study the relation between Lyapunov function and exponential trichotomy for the linear equation on time scales. Furthermore, as an application of these results, we give the roughness of exponential trichotomy on time scales. 1. Introduction Exponential trichotomy is important for center manifolds theorems and bifurcation theorems. When people analyze the asymptotic behavior of dynamical systems, exponential trichotomy is a powerful tool. The conception of trichotomy was first introduced by Sacker and Sell [1]. They described SS-trichotomy for linear differential systems by linear skew-product flows. Furthermore, Elaydi and Hájek [2, 3] gave the notions of exponential trichotomy for differential systems and for nonlinear differential systems, respectively. These notions are stronger notions than SS-trichotomy. In 1991, Papaschinopoulos [4] discussed the exponential trichotomy for linear difference equations. And in 1999 Hong and his partners [5, 6] studied the relationship between exponential trichotomy and the ergodic solutions of linear differential and difference equations with ergodic perturbations. Recently, Barreira and Valls [7, 8] gave the conception of nonuniform exponential trichotomy. From their papers, we can see that the exponential trichotomy studied before is just a special case of the nonuniform exponential trichotomy. For more information about exponential trichotomy we refer the reader to papers [9–14]. Many phenomena in nature cannot be entirely described by discrete system, or by continuous system, such as insect population model, the large population in the summer, the number increases, a continuous function can be shown. And in the winter the insects freeze to death or all sleep, their number reduces to zero, until the eggs hatch in the next spring, the number increases again, this process is a jump process. Therefore, this population model is a discontinuous jump function, it cannot be expressed by a single differential equation, or by a single difference equations. Is it possible to use a unified framework to represent the above population model? In 1988, Hilger [15] first introduced the theory of time scales. From then on, there are numerous works on this area (see [16–23]). Time scales provide a method to unify and generalize theories of continuous and discrete dynamical systems. In this paper, motivated by [8], we study the exponential trichotomy on time scales. We firstly introduce -Lyapunov function on time scales. Then we study the relationship between exponential trichotomy and -Lyapunov function on time scales. We
Research of Teaching Innovation on the Course of Water Resources Planning and Utilization  [PDF]
Baohui Men, Shanghong Zhang, Changming Ji, Cheng Zhang, Yanke Zhang
Creative Education (CE) , 2017, DOI: 10.4236/ce.2017.810115
Abstract: Objective: To innovate the teaching contents and teaching methods for the course of Water Resources Planning and Utilization which is one of the Hydrology and Water Resources Engineering professional 433 core courses of NCEPU. Methods: Literature review, modification of the course syllabus, text-books, curriculum design task and construction of the professional teachers’ team. Results: According to the basic requirements of the course construction of Water Resources Planning and Utilization, we have made some enrichment, expansion and necessary complements to the teaching contents. We have also tried to impart professional knowledge to students and to develop their practical abilities in the professional field of water resources. Gradually our under-graduate students are able to independently complete the summary of an academic paper, which includes their research methods, result analysis and conclusion drawing by writing their course papers. Conclusion: The innovation of the course of Water Resources Planning and Utilization is very successful by updating the content and changing the teaching method.
Facile Synthesis of Polypyrrole/Titanate Core-Shell Nanorods and Their Electrorheological Characteristics  [PDF]
Jiexu Zhang, Ying He, Lijun Ji
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.22015
Abstract: In this work, polypyrrole (PPy)/titanate (TN) composite nanorods were successfully synthesized using cetyl trimethyl-ammonium bromide (CTAB) as a structure-directing agent by in situ chemical oxidative polymerization. The structural characterization indicated that the new composite rods were core (TN)-shell (PPy) nanostructure with the average diameter in the range of 250-300 nm. Further, this semiconducting composite can be used as a dispersed phase in silicone oil for a new electrorheological (ER) fluid, and its ER behavior was investigated under steady and oscillatory shear. It was found that the PPy/TN fluid showed typical ER characteristics under an external electric field.
Second Descendible Self-Mapping with Closed Periodic Points Set  [PDF]
Gengrong Zhang, Zhanjiang Ji, Fanping Zeng
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.47133
Abstract:

Let \"\"and f:XnXn be a continuous map. If f is a second descendible map, then P(f) is closed if and only if one of the following hold: 1) \"\" ; 2) For any z ε R (f), there exists a yεw (z,f) P(f) such that every point of the set orb (y,f) is a isolated point of the set w (z,f); 3) For any z ε R(f), the set w (z,f) is finite; 4) For any z ε R(f), the set w' (z,f) is finite. The consult give another condition of f with closed periodic set other than [1].

Nonlinear Polarization Rotation Characteristic Phenomenon in a Bulk Semiconductor Optical Amplifier  [PDF]
Xianghua Feng, Jiarong Ji, Guomin Zhang
Optics and Photonics Journal (OPJ) , 2013, DOI: 10.4236/opj.2013.32B045
Abstract:

The phenomena of polarization rotation induced by self-modulation in semiconductor optical amplifier (SOA) are analyzed theoretically. The relationship between polarization parameters and gain as well as phase is obtained by the correlation parameter of ellipse polarization and SOA nonlinearity polarization rotation theory. The experiment employs polarizer drive by walking electromotor and power meter, the light power of 360 degree is measured. The transformation law of output polarization power components is found for obvious polarization rotation in the selected coordinate axes based on connection of polarization state in difference axes. Using this law make the manipulation easily on getting ideal polarization state. It can offer a fine method to realize all-optical switch and other logic elements in experiment. This work is of great significance for the applications of SOA nonlinear polarization rotation at high-speed all-optical signal processing and all-optical logic gate.

Investigation of an Adenovirus-Induced Respiratory Disease Outbreak  [PDF]
Xingyi Geng, Ji Zhang, Guoliang Yang
Advances in Infectious Diseases (AID) , 2013, DOI: 10.4236/aid.2013.34039
Abstract:

Objective: An epidemiological investigation was carried out in school X in Jinan, Shandong Province, China, to identify the cause, epidemiology, and etiological characteristics of a febrile respiratory disease outbreak; and therefore to control the dissemination. Methods: Both field epidemiological investigations and laboratory examinations were carried out. Results: Forty cases were identified, in which 38 cases were students and two were teachers. Clinical manifestations included fever, coughing, headache, and sore throat. A total of 21 pharyngeal swab specimens were collected and 18 tested positive for adenovirus. The adenovirus hexon gene was sequenced in three of the 18 positive specimens and the results showed a 100% homology with the standard HAdV-55 HEXO. Conclusions: The outbreak originated from an adenovirus-infected student, who spread the pathogen to her classmates and teacher. The teacher then further disseminated the disease within the school which led to 40 febrile respiratory infections.

 

The Intelligent Terminal Design for Integrated Substation Auxiliary System  [PDF]
Enliang Pang, Sanfeng Zhang, Yi Ji
Journal of Software Engineering and Applications (JSEA) , 2013, DOI: 10.4236/jsea.2013.65B003
Abstract: The integrated substation auxiliary system is a project composed by software and hardware to help operators of a substation carry daily maintain works. The intelligent terminal is the key part of the system and it provides important UI and communication functions for the user. Smart phones can achieve higher bandwidth data communication, and at the same time can carry Bluetooth communication, video call, multimedia display and other functions. Smart phone is a potential common platform, suitable for the deployment of substation integrated auxiliary system terminal. Based on the Android Smart phone platform, this paper develops intelligent client-side software for the integrated substation auxiliary system and it can realize the operation ticket control, the video call, the substation map display and other functions. This client-side software has been applied in practice, and has gained good effects.
Vitamin E Therapy in Non-Alcoholic Fatty Liver Disease  [PDF]
Xiangbing Shu, Li Zhang, Guang Ji
International Journal of Clinical Medicine (IJCM) , 2014, DOI: 10.4236/ijcm.2014.53016
Abstract:


Non-alcoholic fatty liver disease (NAFLD) is closely related to oxidative stress. Vitamin E (VE) is an effective antioxidant, which could relieve NAFLD symptoms by improving the balance of oxidation and anti-oxidation. However, recent researches indicate that the functional mechanisms of VE are not only limited to anti-oxidation, but also include adjusting the metabolism disorders of glucose and lipid. Furthermore, the efficacy of VE remains controversial in the treatment of NAFLD by far, and the suitable condition of patient, drug dosage, drug safety and course of treatment during clinical application still need to be discussed. Therefore, this paper reviewed the recent study progresses of clinical application of VE alone and VE and other drugs.


The Study of 1 + X Evaluation Mode Reform  [PDF]
Tian Zhang, Man Liu, Qiang Ji
Creative Education (CE) , 2014, DOI: 10.4236/ce.2014.516163
Abstract: To solve the question of the present situation of professional education, we analyze the outstanding problems of the process, and put forward the design of content, the main measures of reform and the relationship that should be handled in the process of 1 + X evaluation mode reform, in order to adapt to the reform of the professional education, and build a scientific and reasonable system of 1 + X evaluation mode. Accordingly, we can improve the quality of teaching and talent training.
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