oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 12 )

2019 ( 96 )

2018 ( 374 )

2017 ( 370 )

Custom range...

Search Results: 1 - 10 of 28426 matches for " Zhihong Ma "
All listed articles are free for downloading (OA Articles)
Page 1 /28426
Display every page Item
Gaseous and Electrochemical Hydrogen Storage Properties of Nanocrystalline Mg2Ni-Type Alloys Prepared by Melt Spinning  [PDF]
Zhihong Ma, Bo Li, Huiping Ren, Zhonghui Hou, Guofang Zhang, Yanghuan Zhang
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.23018
Abstract: A partial substitution of Ni by Cu has been carried out in order to improve the hydrogen storage characteristics of the Mg2Ni-type alloys. The nanocrystalline Mg20Ni10-xCux (x = 0, 1, 2, 3, 4) alloys are synthesized by the melt-spinning technique. The structures of the as-cast and spun alloys have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM). The electrochemical performances were evaluated by an automatic galvanostatic system. The hydrogen absorption and desorption kinetics of the alloys were determined by using an automatically controlled Sieverts apparatus. The results indicate that the substitution of Cu for Ni does not alter the major phase Mg2Ni. The Cu substitution significantly ameliorates the electrochemical hydrogen storage performances of alloys, involving both the discharge capacity and the cycle stability. The hydrogen absorption capacity of alloys has been observed to be first increase and then decrease with an increase in the Cu contents. However, the hydrogen desorption capacity of the alloys exhibit a monotonous growth with an increase in the Cu contents.
Biocompatibility of Porous Spherical Calcium Carbonate Microparticles on Hela Cells  [PDF]
Yaran Zhang, Ping Ma, Yao Wang, Juan Du, Qi Zhou, Zhihong Zhu, Xu Yang, Junlin Yuan
World Journal of Nano Science and Engineering (WJNSE) , 2012, DOI: 10.4236/wjnse.2012.21005
Abstract: Recently there has been a wide concern on inorganic nanoparticles as drug delivery carriers. CaCO3 particles have shown promising potential for the development of carriers for drugs, but little research had been performed regarding their safe dosage for maximizing the therapeutic activity without harming biosystems. In this study, we assessed the biological safety of porous spherical CaCO3 microparticles on Hela cells. The reactive oxygen species (ROS), glutathione (GSH), carbonyl content in proteins (CCP), DNA-protein crosslinks (DPC) and cell viability were measured. Results showed that with the exposure concentration increase, ROS and CCP in Hela cells presented a significant increase but GSH contents in Hela cells and cell viability showed a significant decrease respectively compared with the control. DPC coefficient ascended, but no statistically significant changes were observed. The results indicated that porous spherical CaCO3 microparticles may induce oxidative damage to Hela cells. But compared with other nanomaterials, porous spherical CaCO3 appeared to have good biocompatibility. The results implied that porous spherical calcium carbonate microparticles could be applied as relatively safe drug vehicles, but with the caveat that the effect of high dosages should not be ignored when attempting to maximize therapeutic activity by increasing the concentration.
Research on the Influence of Political Correlation of Private Listed Companies on Corporate Social Responsibility Behavior  [PDF]
Zhihong Fu
American Journal of Industrial and Business Management (AJIBM) , 2019, DOI: 10.4236/ajibm.2019.93040
Abstract:
Based on the perspective of legitimacy, this paper uses the Logistic and OLS regression methods to analyze the relationship between the release of CSR reports issued by private companies from 2010 to 2016 and the relationship between report quality and executive political connections. The analysis shows that executive political relations can significantly affect the quality of private companies in the CSR report release and publication possibility of CSR report. According to the analysis results, the paper finally proposes how to promote corporate social responsibility by exerting the political correlation role of executives. Through theoretical and empirical research, it analyzes the influence of executive political association on corporate financial performance and social responsibility, and analyzes and verifies the role of regional marketization development process in private social responsibility behavior and political association formation motivation, thus making private enterprise politics rational use of related resources, standardizing and guiding the commitment of civil society’s social responsibility, and providing corresponding policy recommendations for promoting healthy and sustainable economic development. Secondly, this study analyzes the influence of executive political connections on corporate social responsibility behavior from a multi-theoretical perspective, and provides more analytical perspectives for future related research.
Key Issues for Implementing Smart Polishing in Semiconductor Failure Analysis  [PDF]
Jacobus Leo, Hao Tan, Yinzhe Ma, Shreyas M. Parab, Yamin Huang, Dandan Wang, Lei Zhu, Jeffrey Lam, Zhihong Mai
Journal of Applied Mathematics and Physics (JAMP) , 2017, DOI: 10.4236/jamp.2017.59139
Abstract:
“Industry 4.0” has become the future direction of manufacturing industry. To prepare for this upgrade, it is important to study the automation of semiconductor failure analysis. In this paper, the sample polishing activity was studied for upgrading to a smart polishing process. Two major issues were identified in implementing the smart polishing process: the optimization of current polishing recipes and the capability of making decisions based on live feedback. With the help of Solver add-in, the current polishing recipes were optimized. To make decisions based on live images captured during polishing, strategies were explored based on finger polishing process study. Our investigation showed that a grey scale line profile analysis on images can be used to build the vision capability of our smart polishing system, on which a decision- making capability can be developed.
Secrecy Transfer
Zhihong Liu,Jianfeng Ma,Yong Zeng,Li Yang,YoungHo Park
International Journal of Distributed Sensor Networks , 2012, DOI: 10.1155/2012/847805
Abstract: Suppose that n nodes with 0 acquaintances per node are randomly deployed in a two-dimensional Euclidean space with the geographic restriction that each pair of nodes can exchange information between them directly only if the distance between them is at most r, the acquaintanceship between nodes forms a random graph, while the physical communication links constitute a random geometric graph. To get a fully connected and secure network, we introduce secrecy transfer which combines random graph and random geometric graph via the propagation of acquaintanceship to produce an acquaintanceship graph ,0, a kind of random geometric graph with each edge representing an acquaintanceship between two nodes. We find that components of graph ,0 that undergoes a phase transition from small components to a giant component when 0 is larger than a threshold, the threshold for ,0 to be a connected graph is derived. In addition, we present its implementation method and applications in wireless sensor networks.
Association between COX-2 rs2745557 polymorphism and prostate cancer risk: a systematic review and meta-analysis
Hongtuan Zhang, Yong Xu, Zhihong Zhang, Ranlu Liu, Baojie Ma
BMC Immunology , 2012, DOI: 10.1186/1471-2172-13-14
Abstract: A comprehensive search was conducted to identify all case-control studies of COX-2 rs2745557 polymorphism and PCa risk. We used odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) give a sense of the precision of the estimate. Statistical analyses were performed by Review Manage, version 5.0 and Stata 10.0.A total of 8 available studies were considered in the present meta-analysis, with 11356 patients and 11641 controls for rs2745557. When all groups were pooled, there was no evidence that rs2745557 had significant association with PCa under co-dominant, recessive, over-dominant, and allelic models. However, our analysis suggested that rs2745557 was associated with a lower PCa risk under dominant model in overall population (OR = 0.85, 95%CI = 0.74-0.97, P = 0.02). When stratifying for race, there was a significant association between rs2745557 polymorphism and lower PCa risk in dominant model comparison in the subgroup of Caucasians (OR = 0.86, 95%CI = 0.75-0.99, P = 0.04), but not in co-dominant, recessive, over-dominant and allelic comparisons.Based on our meta-analysis, COX-2 rs2745557 was associated with a lower PCa risk under dominant model in Caucasians.PCa is one of the most frequently diagnosed malignancies and a common cause of cancer mortality in men in the Western hemisphere [1,2]. Identifying risk factors for PCa is critically important to develop potential interventions and to expand our understanding of the biology of this disease. Despite the fact that the complex etiology of PCa remains obscure, various risk factors play an important role in PCa development such as advanced age, environmental variations, culture changes, and genetic variations. A strong association exists between states of chronic inflammation and cancer, and it is believed that mediators of inflammation may be responsible for this phenomenon [3]. Chronic inflammation may lead to tumorigenesis by damaging DNA through radical oxygen and nit
The Diagnosis of Components Information Distribution of Wheat Seedlings Based on the Hyperspectral Imaging
Qiong Wu,Dazhou Zhu,Cheng Wang,Zhihong Ma
Advance Journal of Food Science and Technology , 2012,
Abstract: It is adopted mostly of the non-imaging spectrometer in current crop seedling monitoring, this method is greatly interfered by the soil background, makes it difficult to analyze the partial area nutritional status of the seedlings. In this study, we took advantage of merging the image with spectrum of the imaging spectrometer, to analyze the canopy, individuals, different size of leaves, characteristics of different regions of the wheat seedlings under the condition of salt stress, to diagnose the distribution of its chlorophyll composition information. We collected the imaging spectrum of 126 wheat samples in the wavelength range of 400 ~1000 nm, selected the average spectrum, exerted Correlation Analysis on the spectrum of wheat seedlings with the SPAD value, It could be seen that the biggest absolute value of the correlation coefficient was at 693 nm, which was considered as the characteristics wavelength of wheat seedlings. To establish the linear regression model using this wavelength and substituted 1the reflectance data of each point into the model, then we got the SPAD value of each point, to form the relative content distribution map of chlorophyll, whereby to diagnose the distribution of seedlings component. The results showed that: Hyper spectral imaging could reflect the reflectance differences of wheat seedlings under different salt stress treatments, through extracting the spectral reflectance curve leaves of single wheat seedlings in different parts of the different leaves and single leaf base, the midst of leaves and tip in the plant, from the results of filling map we could intuitively see the leaves’ chlorophyll distribution in different parts. It indicated that hyper spectral imaging can characterize the seedlings situation of different plants, also could characterize the characteristics of different district of leaves. The results indicated that hyper spectral imaging were suitable for the non-invasive detection of chlorophyll content of wheat seeding and it has potential for precise diagnosing of the growing status of wheat seeding.
Association of Methylenetetrahydrofolate Dehydrogenase 1 Polymorphisms with Cancer: A Meta-Analysis
Hongtuan Zhang, Hui Ma, Liang Li, Zhihong Zhang, Yong Xu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069366
Abstract: Background Studies investigating the association between single-nucleotide polymorphisms (SNPs) of the methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) and cancer risk report conflicting results. To derive a more precise estimation of the relationship between MTHFD1 polymorphisms and cancer risk, the present meta-analysis was carried out. Methodology/Principal Findings A comprehensive search was conducted to determine all the eligible studies about MTHFD1 polymorphisms and cancer risk. Combined odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association between the MTHFD1 polymorphisms and cancer risk. We investigated by meta-analysis the effects of 2 polymorphisms in MTHFD1: G1958A (17 studies, 12348 cases, 44132 controls) and G401A (20 studies, 8446 cases, 14020 controls). The overall results indicated no major influence of these 2 polymorphisms on cancer risk. For G1958A, a decreased cancer risk was found in acute lymphoblastic leukemia (ALL)/Asians (the dominant: OR = 0.74, 95% CI = 0.58–0.94, P = 0.01; allelic: OR = 0.80, 95% CI = 0.65–0.99, P = 0.04) and other cancers (recessive: OR = 0.80, 95% CI = 0.66–0.96, P = 0.02). For G401A, the data showed that MTHFD1 G401A polymorphism was associated with a decreased colon cancer risk under dominant model (OR = 0.89, 95% CI = 0.80–0.99, P = 0.04). Conclusions The results suggest that MTHFD1 G1958A polymorphism might be associated with a decreased risk of ALL and other cancers. Meanwhile, the MTHFD1 G401A might play a protective role in the development of colon cancer. Large-scale and well-designed case-control studies are necessary to validate the risk identified in the present meta-analysis.
Sensitivity Analysis of Parameters in Water Quality Models and Water Environment Management  [PDF]
Dongjun Liu, Zhihong Zou
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.328101
Abstract: The impacts of changes of various parameters and stochastic factors on water quality models were studied. The impact of deviation of the degradation coefficient on the model results was investigated. The degradation coefficient was decomposed into the exact part and the deviation part, and the relationship between the errors of the water quality model results and the deviation of the degradation coefficient was derived. The impact of changes in the initial concentration on the model results was discussed. A linear relationship between the initial concentration changes and errors in the model results was obtained, and relevant recommendations to the water quality management were made based on the results. The impacts of stochastic factors in the water environment on the water quality model were analyzed. A variety of random factors which may affect the water quality conditions were attributed to one stochastic factor and it was further assumed to be the white noise. The solutions to the water quality model including the stochastic process were obtained by solving the stochastic differential equation. Simulation results showed that the decay trend of the concentration of the solute would not be changed, and that the results would fluctuate around the expectation centered at each corresponding displacement x
Free Vibration Analysis of Elastic Bodies for Six-Axis Force Sensor  [PDF]
Dezhang Xu, Zhihong Wang
Journal of Sensor Technology (JST) , 2013, DOI: 10.4236/jst.2013.31003
Abstract:

Now the six-axis force sensor (6-AFS) is used widely, and as the core components, mechanical properties of its elastic bodies are significant. With the increase of dynamic loads, studies on dynamic characteristics of the 6-AFS become more and more important. In this paper, the study focuses on the free vibration problem of a novel 6-AFS. The research approach is to decompose the sensor into several separate elastic bodies (four lamellas and upper and lower membranes) and research these elastic bodies respectively. The free vibration of the lamella is studied based on Rayleigh-Ritz method and the separation of variables. The analytical solutions of free vibration of the membranes are deduced according to the nature of Bessel functions. Both the analytical results are simulated with MATLAB. Compared the simulated diagrams with actual situations, they are very close. The mode shapes obtained play a major role in solving the forced vibration of the sensor.

Page 1 /28426
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.