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Search Results: 1 - 10 of 119541 matches for " Lifang Wang "
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A note on products of finite groups
Lifang Wang,Yanming Wang
International Journal of Algebra , 2012,
Abstract:
Marginal Distribution in Copula Estimation of Distribution Algorithm Based Dynamic K-S test
Zhao Hui,Wang Lifang
International Journal of Computer Science Issues , 2012,
Abstract: Estimation of distribution algorithms based on copula, and a number of different distribution functions were selected as the dimension of the marginal distribution function by applying K-S test. Dynamic K-S test, that is, dynamic adjust frequency of K-S test in different stages. In the estimation of the probability model stage, according to the actual distribution of the dominant group respectively subject to inspection of the distribution function of each dimension. In the parameter estimation stage, according to fix the copula function parameters to make the emulation experiment. According to the obedience of the different marginal distribution function to sample separately, thus increasing the diversity of the population, and improving an execution efficiency of the estimation of distribution algorithms based on copula.
Total Flavonoid Content, the Antioxidant Capacity, Fingerprinting and Quantitative Analysis of Fupenzi (Rubus chingii Hu.)  [PDF]
Huajin Zeng, Ran Yang, Lifang Lei, Yaping Wang
Chinese Medicine (CM) , 2015, DOI: 10.4236/cm.2015.64023
Abstract: Objective: In this study, one of the objectives was to investigate the total flavonoid contents of Fupenzi (R. chingii Hu.) obtained from different regions of China and to evaluate their anatioxidant activities. And the second objective of this study was to develop a validated HPLC method for chromatographic fingerprints of the samples extracts of Fupenzi. Method: The total flavonoid contents were determined by a colorimetric method and the antioxidant activity was determined spectrophotometrically by DPPH and ABTS radical scavenging assays. The chromatographic fingerprint was developed by high-performance liquid chromatography coupled with diode array detection for the control of Fupenzi. Results: A significant correlation between antioxidant activity and the total flavonoid content was observed for the DPPH assay (r2 = 0.758, ρ = 0.004) and the ABTS assay (r2 = 0.788, ρ = 0.002). Under the optimized chromatographic conditions, the validated method was successfully applied to assessment of chemical fingerprinting of 12 batches of FPZ collected from different regions of China. Comparisons of the chromatograms showed that 15 characteristic peaks could be selected as markers for identification and evaluation of Fupenzi. In addition, the proposed method was also successfully applied to simultaneous determination of five compounds (including puerarin, rutin, hyperin, quercetin and kaempferol) in these samples. Conclusions: The qualitative and quantitative analysis described in this paper could be used for identification and evaluation of Fupenzi.
Corrigendum. Finite Groups in which (S )Semipermutability is a Transitive Relation, International Journal of Algebra, 2(3), 2008, 143-152
Lifang Wang,Yangming Li,Yanming Wang
International Journal of Algebra , 2012,
Abstract:
A 180-Day Subchronic Oral Toxicity Study of Total Flavones of E. leptorrhizum Stearn in Rats  [PDF]
Ting Liu, Lianqiang Hui, Chunyu Cao, Ran Hao, Shuangrong Gao, Rong He, Baoqiang Dai, Lifang Wang
Chinese Medicine (CM) , 2015, DOI: 10.4236/cm.2015.61005
Abstract: A subchronic oral toxicity was conducted to evaluate the safety of total flavones of E. leptorrhizum Stearn in Sprague-Dawley rats. The test article was administered once daily by gavage in male and female rats at dose levels of 24, 48, and 96 mg/kg body weight/day for 180 days. 90 and 180 days after administration, ten and tweedy animals (each half of male and female) of each group were tested. 28 days after withdrawal, five male and female rats were tested. There were no significant toxicological changes shown in daily clinical signs, body weight, food consumption, hematology parameters, blood biochemistry, organ weights and histopathological examination except leukocyte differential count. It was concluded that the no-observed-effect level (NOEL) for total flavones of E. leptorrhizum Stearn was >96 mg/kg in SD rats.
Systematic Analysis of Conducted Electromagnetic Interferences for the Electric Drive System in Electric Vehicles
Yanjie Guo;Lifang Wang;Chenglin Liao
PIER , 2013, DOI: 10.2528/PIER12092816
Abstract: There are serious electromagnetic compatibility (EMC) problems in electric vehicles. In order to explain and solve them, a systematic method to analyze conducted interferences of the electric drive system is shown in this paper. This method represents the effects of the power battery which is the most different part between electric drive systems used in electric vehicles and other cases. Also, Equivalent models are established from power electronics devices to the entire system by considering both the working mechanism and stray parameters. Firstly, insulated gate bipolar transistor (IGBT) and inverter are studied as the main interference source. A new expression is put forward to estimate the frequency domain features of the inverter disturbances. Then, power battery and electric motor are discussed as the main propagation paths. Their high frequency circuit models are given with parameters obtained from tests and measurements. Finally, the system model is established. The system interferences are analyzed to get their generation causes, influence factors and frequency domain characteristics. Comparisons between simulations and experiments verify the correctness of the models and the method.
Modeling and Analysis of Conducted Electromagnetic Interference in Electric Vehicle Power Supply System
Yanjie Guo;Lifang Wang;Chenglin Liao
PIER , 2013,
Abstract: Electromagnetic interference (EMI) of the power supply system in electric vehicles will seriously affect the safety of the vehicle and passengers' health. So a model of power supply system is presented to analyze its conducted EMI in the paper. This model shows the effects of paralleled interleaving DC/DC converter, which contains the new circular current EMI characteristics. Also, a novel power battery model is established considering both the energy dynamic processes and the high frequency features. Firstly, the power electronics devices are studied as the most important part of the DC/DC converter. Then, the equivalent model of the paralleled interleaving DC/DC converter is set up to express the interference source features. Also, the power battery, which is the main energy storage equipment in electric vehicles, is modeled as EMI propagation paths. Furthermore, loads of the power supply system, such as lead acid battery and low voltage devices, are investigated to evaluate their immunity. Finally, the system model is established. The system EMI is analyzed to get their generating causes, time domain and frequency domain characteristics based on both simulations and experiments.
Operator Product Formula for a Special Macdonald Function  [PDF]
Lifang Wang, Ke Wu, Jie Yang
Applied Mathematics (AM) , 2018, DOI: 10.4236/am.2018.94033
Abstract:
In this paper, we construct two sets of vertex operators S+ and S? from a direct sum of two sets of Heisenberg algebras. Then by calculating the vacuum expectation value of some products of vertex operators, we get Macdonald function in special variables xi = t i-1 ( i = 0,1, 2,\"\"). Hence we obtain the operator product formula for a special Macdonald function Pλ (1,t,\"\",tn-1;q,t ) when n is finite as well as when n goes to infinity.
A novel mechanism controls anther opening and closing in Paris polyphylla var. Yunnanensis
DingKang Wang,GuiFang Sun,LiFang Wang,ShuHua Zhai,XiaoJiang Cen
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-008-0507-y
Abstract: The phenomena of anther opening and closing in Paris polyphylla var. yunnanensis (Franch) Hand.-Mazz were described in detail, and the effects of ecological factors on those phenomena related to anther opening, closing and the fly-pollination mechanism were discussed. Anthers of P. polyphylla var. yunnanensis open in the morning and close in the evening every day during an over 20 days’ period of anthesis. Light was detected as the main factor controlling this daily anther opening and closing. Anther opening can be reversed in response to rain and re-opens when rain stops. Relative humidity (RH) has a slight effect on anther opening and closing. Flower spans can be prolonged under laboratory conditions. This novel behavior of anther is likely to be a mechanism to enhance the male fitness in this species, of which has no inherited structure to protect pollen from the perianth.
Application of GDAHP on Quality Evaluation of Urban Lake Landscape  [PDF]
Lifang QIAO, Yichuan ZHANG
Journal of Water Resource and Protection (JWARP) , 2009, DOI: 10.4236/jwarp.2009.16051
Abstract: The quality evaluation of urban lake landscape (QEULL) is extremely important for the healthy development of lake landscape. In this research, the evaluation model was established with the group decision analytic hierarchy process (GDAHP) method, which consisted of four layers including the target layer, the factor layer, the index layer and the criterion layer, thus forming a model tree based on their subordinate relation-ships. The GDAHP method was employed to determine the weights of constituting factors of each layer in the evaluation model, and the fuzzy method was used to establish the factors remark sets of the criterion layer, thus the single-layer evaluation and comprehensive evaluation of urban lake landscape quality was carried out. Quality evaluation model of urban lake landscape established based on the GDAHP method can provide grounds for planning, design, and renewal of urban lake landscape. This model has been used to evaluate and analyze the artificial lake in People’s Park of Xinxiang City, Henan Province. The results proved that the overall landscape quality of the artificial lake of Peoples Park in Xinxiang city was good.
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