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Search Results: 1 - 10 of 78494 matches for " Guoping Chen "
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Periodic Boundary Value Problems for a Class of Impulsive Functional Differential Equations of Hybrid Type
Guoping Chen
ISRN Applied Mathematics , 2014, DOI: 10.1155/2014/657629
Abstract: This paper is concerned with the existence of extreme solutions of periodic boundary value problems for a class of first-order impulsive functional differential equations of hybrid type. We obtain the sufficient conditions for existence of extreme solutions by using upper and lower solutions method coupled with monotone iterative technique. 1. Introduction The theory of impulsive differential equations is now being recognized to be not only richer than the corresponding theory of differential equations without impulses but also represents a more natural framework for mathematical modeling of many real-world phenomena [1–3]. Significant progress has been made in the theory of systems of impulsive differential equations in recent years (see [4–18] and the references cited therein). It is well known that the monotone iterative technique offers an approach for obtaining approximate solutions of nonlinear differential equations; for details, see [19] and the references therein. There also exist several works devoted to the applications of this technique to periodic boundary value problems of impulsive differential equations; see [20–26]. In [27, 28], the authors introduce a new concept of upper and lower solutions for periodic boundary value problems of a class of first-order functional differential equations. In paper [23], the authors applied this new concept to study the periodic boundary value problems for first-order impulsive functional differential equations. Motivated by [23, 27, 28], we will study periodic boundary value problem for the first-order impulsive functional differential equation of hybrid type where , , , , denotes the jump of at , , and represent the right and left limits of at , respectively. Denote . The integral part in (1) is defined by where , , , , , , and . Let , is continuous for , , , and exist, and , . is continuously differentiable for , . and are Banach spaces with the norms By a solution of (1), we mean a for which problem (1) is satisfied. Note that (1) has a very general form; as special instances resulting from (1), one can have impulsive differential equations with deviating arguments and impulsive differential equations with the Volterra or Fredholm operators. For example, if does not include and , then (1) reduces to periodic boundary problem for impulsive differential equations with deviating arguments, which is discussed in [22, 23]; when , (1) is the following periodic boundary problem for impulsive integrodifferential equations of mixed type: similar problems are also discussed in [24–26]. 2. Preliminaries To
Dynamic Performance Research on Reversing Valve of Hydraulic Breaker  [PDF]
Guoping Yang, Yubao Chen, Bo Chen
World Journal of Mechanics (WJM) , 2012, DOI: 10.4236/wjm.2012.26035
Abstract: The structure and operational principle on a new type reversing valve of hydraulic breaker are introduced. The nonlinear mathematic model and simulation model of the new type reversing valve are built. The dynamic simulation research of the new type reversing valve is conducted. The effects of the system parameters on the working performance are researched systematically and deeply. The regular understanding on the motion of the reversing valve is obtained, which provides theoretical basis for the innovation and manufacturing of a new generation of hydraulic breaker reversing valve.
The Research of New Type Hydraulic Breaker with Strike Energy and Frequency of Adjusted
Guoping Yang,Yubao Chen
Mechanical Engineering Research , 2012, DOI: 10.5539/mer.v2n2p45
Abstract: After analyzing the technology of hydraulic breaker at home and abroad, this paper challenges tradition and develops a new full hydraulic pressure hydraulic breaker with strike energy and frequency adjusted steplessly and independently, and discuss its working principle, structural feature and hydraulic system, analyses its technical properties and presents experiment results. With all the achievements mentioned above, it establishes technology foundation for the development of hydraulic breaker.
Endovascular Treatment Options of Acute Limb Ischemia  [PDF]
Di Zhang, Wensheng Lou, Guoping Chen, Xindao Yin, Jianping Gu
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2013, DOI: 10.4236/ijmpcero.2013.21006
Abstract:
Acute limb ischemia is a urgent condition which occurs when there is an abrupt interruption of blood flow into an extremity usually because of either embolic or thrombotic vascular occlusion. Restoration of perfusion through early intervention can decrease amputation and mortality. Contemporary treatment includes both surgery and endovascular techniques. There is a rapid progress in endovascular intervention therapy. This article aims to make a comprehensive review of the endovascular intervention options of acute limb ischemia.
Quantum Corrections on Tunneling Radiation by the Generalized Uncertainty Principle  [PDF]
Bingbing Chen, Guoping Li, Xiaotao Zu, Jian Tang
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.65063
Abstract: Based on the generalized uncertainty principle (GUP), the researchers find that the quantum gravity affects the Klein-Gordon equation exactly. Hence, the Klein-Gordon equation which is corrected by GUP will be more suitable on the expression of the tunneling behavior. Then, the corrected Hawking temperature of the GHS black hole is obtained. After analyzing this result, we find out that the Hawking temperature is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we infer that the Hawking radiation will be stopped, and the remnants of black holes exist naturally.
Establishing Multicultural-Oriented Teacher Education System: An Empirical Research on Cultural Conflicts between Teachers and Students in Tibet  [PDF]
Guoping Zheng
Open Journal of Social Sciences (JSS) , 2014, DOI: 10.4236/jss.2014.26047
Abstract: This study aimed at gaining an in-depth knowledge of cultural conflicts between Han and Tibetan teachers, between teachers and students in Tibetan Autonomous Region, then discussed and analyzed the reasons for that, and finally attempted to solve the issue by establishing culture-oriented teacher education system. This study chose Dazi Junior Middle School as the case empirical study. Data for this study were gathered through interviews, participant observations, questionnaire surveys and document analysis, to analyze the cultural conflicts and its reasons. Findings suggest that teachers are “professionals” as well as “cultural workers”, also teacher cultural buildings and works. The mission of teacher education is to preserve and establish the ecology of the cultural development of teachers to promote teacher’s self-development in the interaction of self-being and self-making culture. Therefore, Teacher education system based on multi culture in ethnic minority regions should be established to realize multi-cultural harmonious symbiosis.
Dependence of Spreading and Differentiation of Mesenchymal Stem Cells on Micropatterned Surface Area
Wei Song,Naoki Kawazoe,Guoping Chen
Journal of Nanomaterials , 2011, DOI: 10.1155/2011/265251
Abstract: Micropatterning technology is a highly advantageous approach for directly assessing and comparing the effects of different factors on stem cell functions. In this study, poly(vinyl alcohol)- (PVA-) micropatterned polystyrene surfaces were prepared using photoreactive PVA and ultraviolet photolithography with a photomask. The micropatterned surface was suitable for single-cell array formation and long-term cell culture due to the nanometer thickness of nonadhesive PVA layer. Different degrees of cell spreading with the same cell shape were established by adjusting the sizes of circular, cell-adhesive polystyrene micropatterns. Cell spreading and differentiation of mesenchymal stem cells (MSCs) on the micropatterns were investigated at the single-cell level. The assembly and organization of the cytoskeleton were regulated by the degree of cell spreading. Individual MSCs on large circular micropatterns exhibited a more highly ordered arrangement of actin filaments than did those on the small circular micropatterns. Furthermore, the differentiation of MSCs was dependent on the degree of cell spreading. Increased cell spreading facilitated the osteogenic differentiation but suppressed the adipogenic differentiation of MSCs. This micropatterning method is valuable for stem cell research in tissue engineering and regenerative medicine.
Spectral properties of LH2 exhibit very similar even when heterologously express LH2 with β-subunit fusion protein in Rhodobacter sphaeroides  [PDF]
Zhiping Zhao, Xin Nie, Zongli Hu, Guoping Chen, Zaixin Li, Zhi Zhang
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.31013
Abstract:

Interactions between the light-harvesting subunits and the non-covalently bound photopigments attribute considerably to the spectral properties of photosynthetic bacteria light-harvesting complexes. In our previous studies, we have constructed a novel Rhodobacter sphaeroides expression system. In the present study, we focus on the spectral properties of LH2 when heterologously express LH2 with β-subunit- GFP fusion protein in Rb. sphaeroides. Near infra-red spectrum of LH2 remained nearly unchanged as measured by spectroscopy. Fluorescence spectrum suggested that the LH2 with β-subunit-GFP fusion protein complexes still possessed normal activity in energy transfer. However, photopigments contents were significantly decreased to a very low level in the LH2 with β-subunit-GFP fusion protein complexes compared to that of LH2. FT-IR spectra indicated that interactions between photopigments and LH2 α/β- subunits appeared not to be changed. It was concluded that the LH2 spectral properties exhibited very similar even when heterologously expressed LH2 b-subunit fusion protein in Rb. sphaeroides. Our present study may supply a new insight into better understand the interactions between light-harvesting subunits and photopigments and bacterial photosynthesis and promote the development of the novel Rb. sphaeroides expression system.

Response of rice cultivation to fluctuating sea level during the Mid-Holocene
YunFei Zheng,GuoPing Sun,XueGao Chen
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-011-4786-3
Abstract: Archaeological analysis of a section of ancient rice fields at Tianluoshan for diatoms, seeds and phytoliths has shown that the highest local sea level in eastern China during the Holocene appeared before 7.0 ka BP. Entering the Mid-Holocene, as seawater regressed, a vast wetland plain appeared in the coastal area, where farmers of the Neolithic Hemudu culture cultivated rice. However, there were still several sea-level fluctuations in the Mid-Holocene, of which the biggest were from 6.4 to 6.3 ka BP and from 4.6 to 2.1 ka BP. In addition, in the period dominated by wetland grass vegetation, 6.3 to 4.6 ka BP, smaller fluctuations apparently pushed the coastline back on to the land. Even though the sea-level rises associated with these shoreline transgressions did not have the intensity of the highest sea level period, there still would have been profound impacts on the lives and production activities of people living in the region. Archaeological evidence from ancient rice fields at Tianluoshan shows that larger sea-level rise events pushed seawater onto the land and inundated large areas of rice fields, whereas weaker sea-level rise events resulted in the intrusion of seawater along rivers, causing an increase in soil salinity and a decrease in rice yields. The impact of sea-level rise on rice cultivation caused changes in local diet. In regions where rice production fell, the prevalence of gathering and hunting rose. High sea levels in the early Holocene imply that the origin of rice cultivation in the eastern coastal plain is likely to have been in small nearby mountain basins.
Characteristics of the short rachillae of rice from archaeological sites dating to 7000 years ago
YunFei Zheng,GuoPing Sun,XuGao Chen
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0258-1
Abstract: The abscission layer formed on a pedicel situated at the basal part of a short rachilla is an important characteristic for discriminating between wild, japonica, and indica rice. The short rachillae of paddy rice grains excavated from the Kuahuqiao, Luojiajiao, and Tianluoshan sites, located in the lower reaches of the Yangtze River and dating to 7000 years old, were observed. The results showed that the short rachillae could be divided into two types: a wild type and japonica type. These results indicated that the rice had been domesticated, but was a primitive cultivated rice that retained some of the characteristics of wild rice. The results also suggested that the rice was changing to resemble japonica type rice. Based on the ratios of wild and japonica types, it was inferred that rice domestication began 10000 years ago.
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