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Search Results: 1 - 10 of 9159 matches for " Jingfeng Meng "
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The Necessity of Anti-Piracy and Anti-Monopoly in Software Industry
Jingfeng Meng,Xu Xiao
International Journal of Business and Management , 2009,
Abstract: The piracy and monopoly in the software industry is analyzed in this article which shows that they will ultimately endanger the national industry but not the foreign monopoly enterprises. The author considers that the low price of the pirated software and the internets monopoly form are the two reasons to form monopoly. Anti-pirate and anti-monopoly are both imperative ways to develop Chinese software industry. A general strategy regulation in the software industry elicited by this article is to strike piracy in the protected period, shorten moderately protection period of the software product and limit the monopoly manufacturers to some extent.
Dynamic Coal Logistics Facility Location under Demand Uncertainty  [PDF]
Jiang Wu, Jingfeng Li
Open Journal of Social Sciences (JSS) , 2014, DOI: 10.4236/jss.2014.29006
Abstract:

In this paper, dynamic facility location and supply chain planning are studied through minimizing the costs of facility location, path selection and transportation of coal under demand uncertainty. The proposed model dynamically incorporates possible changes in transportation network, facility investment costs, operating cost and changes in facility location. In addition, the time variation and the demand uncertainty for coal in each period of the planning horizon is taken into account to determine the optimal facility location and the optimal production volumes. Computational process and results are presented for the model in a java language. Also, an empirical case study in Shanxi province is conducted in order to investigate the dynamic effects of traffic congestion and demand uncertainty on facility location design and total system costs.

Fabrication and Analysis of Vanadium-Based Metal Powders for Selective Laser Melting  [PDF]
Jialin Yang, Jingfeng Li
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2018, DOI: 10.4236/jmmce.2018.61005
Abstract: Vanadium Alloy is a type of advanced nuclear material with many ideal properties compared as traditional nuclear materials, which has very wide and important application in first-wall and blanket structural material for fusion power plant applications. So it has attracted increasing attentions, especially on new manufacturing methods, such as selective laser melting and so on. In this paper, the comparative study of the powders obtained by mechanical mixing method, dry grinding method and wet grinding method respectively was performed to evaluate the effect of ball milling process on the microstructure and degree of alloying of the vanadium-based powder mixtures with the nominal composition of V5Cr5Ti vanadium alloy. The powders prepared by dry grinding method exhibits better spherical-like morphology and degree of alloying than those prepared by mechanical mixing method and wet grinding method, which indicates that dry grinding method can be used to prepare the superfine vanadium alloy powders for selective laser melting. This work provides a new method as well as important insights into the preparation of superfine vanadium alloy powders for selective laser melting additive manufacturing technology.
Benzopyranones from the Endophytic Fungus Hyalodendriella sp. Ponipodef12 and Their Bioactivities
Xiangjie Meng,Ziling Mao,Jingfeng Lou,Liang Xu,Lingyun Zhong,Youliang Peng,Ligang Zhou,Mingan Wang
Molecules , 2012, DOI: 10.3390/molecules171011303
Abstract: The endophytic fungus Hyalodendriella sp. Ponipodef12 was isolated from the hybrid ‘Neva’ of Populus deltoides Marsh × P. nigra L. In this study, four benzopyranones were isolated from the ethyl acetate extract of Hyalodendriella sp. Ponipodef12, and identified as palmariol B (1), 4-hydroxymellein (2), alternariol 9-methyl ether (3), and botrallin (4) by means of physicochemical and spectroscopic analysis. All the compounds were evaluated for their antibacterial, antifungal, antinematodal and acetylcholinesterase inhibitory activities. 4-Hydroxymellein (2) exhibited stronger antibacterial activity than the other compounds. Palmariol B (1) showed stronger antimicrobial, antinematodal and acetylcholinesterase inhibitory activities than alternariol 9-methyl ether (3) which indicated that the chlorine substitution at position 2 may contribute to its bioactivity. The results indicate the potential of this endophytic fungus as a source of bioactive benzopyranones.
A New Refinement of Generalized H?lder’s Inequality and Its Application
Jingfeng Tian
Journal of Function Spaces , 2013, DOI: 10.1155/2013/686404
Abstract: We present a new refinement of generalized H?lder’s inequality due to Vasi? and Pe?ari?. Moreover, the obtained result is used to improve Beckenbach-type inequality due to Wang. 1. Introduction If , , , and , then The sign of inequality is reversed for , (for ; we assume that ). Inequality (1) and its reversed version are called H?lder’s inequalities and are important in the study of inequalities and in the field of applied mathematics. The important inequalities have attracted interest of many mathematicians and have been improved as well as generalized in several different directions. For example, Barza et al. [1] presented matriceal versions of H?lder’s inequality. Nikolova and Varo?anec [2] obtained some new refinements of the classical H?lder’s inequality by using a convex function. Tian and Hu [3] established a new reversed version of a generalized sharp H?lder’s inequality. For more detailed expositions, the interested reader may consult [1–13] and the references therein. Among various generalizations of (1), Vasi? and Pe?ari? in [14] presented the following interesting theorem. Theorem A. Let .(a)If are positive numbers, such that , then (b)If , and if , then (c)If , then The main objective of this paper is to build some new refinements of inequalities (2), (3), and (4). Moreover, the obtained results will be applied to improve Beckenbach-type inequality which is due to Wang [15]. 2. A New Refinement of Generalized H?lder’s Inequality In this section, we first prove the following lemma, which plays a crucial role in proving our main results. Lemma 1. Let and let .(a) If and if , then ?where .(b)If , and if , then (c)If , then Proof. (a) Without loss of generality, we assume that . Case 1 (when ). It implies that and . According to , by using inequality (2), we have which means that the desired inequality (5) holds for . Case 2 (when ). By applying inequality (2), we obtain That is, inequality (5) is true for . (b) If , , then , . By the same method as in Case 1, we obtain the desired inequality (6). (c) The proof of inequality (7) is similar to the one of inequality (5), and we omit it. The proof of Lemma 1 is completed. Next, we present new refinements of inequalities (2), (3), and (4). Theorem 2. Let , and let be any given natural number .(a) If and if , then ?where .(b)If , and if , then (c)If , then Proof. Consider the following substitution: It is easy to see that, for any given natural number , the following inequalities hold: Consequently, by using the substitution (13) and inequality (5), we have for , , and thus we have that is, So, we
Mandates and the Contributions of Open Genomic Data
Jingfeng Xia
Publications , 2013, DOI: 10.3390/publications1030099
Abstract: This research attempts to seek changing patterns of raw data availability and their correlations with implementations of open mandate policies. With a list of 13,785 journal articles whose authors archived datasets in a popular biomedical data repository after these articles were published in journals, this research uses regression analysis to test the correlations between data contributions and mandate implementations. It finds that both funder-based and publisher-based mandates have a strong impact on scholars’ likelihood to contribute to open data repositories. Evidence also suggests that like policies have changed the habit of authors in selecting publishing venues: open access journals have been apparently preferred by those authors whose projects are sponsored by the federal government agencies, and these journals are also highly ranked in the biomedical fields. Various stakeholders, particularly institutional administrators and open access professionals, may find the findings of this research helpful for adjusting data management policies to increase the number of quality free datasets and enhance data usability. The data-sharing example in biomedical studies provides a good case to show the importance of policy-making in the reshaping of scholarly communication.
The Open Access Divide
Jingfeng Xia
Publications , 2013, DOI: 10.3390/publications1030113
Abstract: This paper is an attempt to review various aspects of the open access divide regarding the difference between those academics who support free sharing of data and scholarly output and those academics who do not. It provides a structured description by adopting the Ws doctrines emphasizing such questions as who, what, when, where and why for information-gathering. Using measurable variables to define a common expression of the open access divide, this study collects aggregated data from existing open access as well as non-open access publications including journal articles and extensive reports. The definition of the open access divide is integrated into the discussion of scholarship on a larger scale.
Research on Fuzzy Recommendation System Based on User Profile  [PDF]
Jingfeng Shao, Xiaoyu Yang, Chuangtao Ma
Open Journal of Social Sciences (JSS) , 2017, DOI: 10.4236/jss.2017.510001
Abstract:
To provide the personalized services for learners according to user’s learning behavior, firstly, through theory of Fuzzy Ontology, the ambiguity and uncertainty of information in E-learning recommendation system was analyzed, and fuzzy information was extended to the ontology. Secondly, the user interest estimation based on behavior was studied in term of user’s learning preferences and cognitive status, user profile was described by the learning object, and then a user model updating algorithm was proposed. Finally, a fuzzy recommendation system based on user profile was built. As verified by experiment, the results have shown that the system can provided the personalized learning services according to user’s learning behavior, and it is useful in describing user preferences.
FRACTURE-MECHANICS ANALYSIS OF COLD-DRAWN Si-Cr VALVE STEEL

by Yin Jiang,Xu Jingfeng,

金属学报 , 1981,
Abstract:
A bulk metal/ceramic composite material with a cellular structure
Zhankui Zhao,Kefu Yao,Jingfeng Li
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-004-0491-9
Abstract: A bulk metal/ceramic composite material with a honeycomb-like micro-cell structure has been prepared by sintering the spherical Al90Mn9Ce1 alloy powders clad by Al2O3 nano-powder with the spark plasma sintering (SPS) technique. The as-prepared material consists of Al90Mn9Ce1 alloy cell and closed Al2O3 ceramic cell wall. The diameter of the cells is about 20–40 μm, while a thickness of the cell wall is about 1–2 μm. The ultimate compressive strength of the as-sintered materials is about 514 MPa, while its fracture strain is up to about 0.65 %. This composite material might possess good anti-corrosion, thermal endurance and other potential properties due to its unique microstructure. The result shows that the Al90Mn9Ce1/Al2O3 composite powders can be sintered by spark plasma sintering technique despite the large difference in their sintering temperature. This work offers a way of designing and preparing metal/ceramic composite material with functional property.
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