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Search Results: 1 - 10 of 126826 matches for " Yingmin Li "
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Substitute materials of furfuryl alcohol in furan resin used for foundry and their technical properties
Ren Yuyan,Li Yingmin
China Foundry , 2009,
Abstract: Based on a special synthesis process of furan resin, the furfuryl alcohol (FA), the main component of typical no-bake furan resins is substituted by ethanol and xylitol mother liquor which is relatively low price and chemically active. Through orthogonal test, the optimal amount of xylitol liquor, ethanol and modifi er has been determined. Finally, the test results on technical properties show that the performance can meet the production requirement well, which indicate a success in this substituting attempt.
Kullback-Leibler divergence for interacting multiple model estimation with random matrices
Wenling Li,Yingmin Jia
Computer Science , 2014,
Abstract: This paper studies the problem of interacting multiple model (IMM) estimation for jump Markov linear systems with unknown measurement noise covariance. The system state and the unknown covariance are jointly estimated in the framework of Bayesian estimation, where the unknown covariance is modeled as a random matrix according to an inverse-Wishart distribution. For the IMM estimation with random matrices, one difficulty encountered is the combination of a set of weighted inverse-Wishart distributions. Instead of using the moment matching approach, this difficulty is overcome by minimizing the weighted Kullback-Leibler divergence for inverse-Wishart distributions. It is shown that a closed form solution can be derived for the optimization problem and the resulting solution coincides with an inverse-Wishart distribution. Simulation results show that the proposed filter performs better than the previous work using the moment matching approach.
A Research on Emergency DC Power Support Based on DCOI  [PDF]
Fan Fan, Yingmin Zhang, Xingyuan Li, Wei Ma
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B166

An integrated scheme of emergency DC power support which is based on dominant center of Inertia DCOI is proposed to improve power system transient stability. The inter-area speed differences equivalent by dominant center of inertia alleviates the main weakness of the traditional signal which is made of the frequencies at both sides and is represent of abnormal information of the nonlinear dynamic behavior of the power system based on a model in which two AC systems are connected by a HVDC Link. Sichuan Power Grid connected with Southwest Power Grid by Deyang-Baoji HVDC project is used to testify the method. The simulation results show that the control strategy can significantly advance the transient stability of AC/DC system through extended equal area criterion (EEAC).

Dynamic Time Warping Distance Method for Similarity Test of Multipoint Ground Motion Field
Yingmin Li,Huiguo Chen,Zheqian Wu
Mathematical Problems in Engineering , 2010, DOI: 10.1155/2010/749517
Abstract: The reasonability of artificial multi-point ground motions and the identification of abnormal records in seismic array observations, are two important issues in application and analysis of multi-point ground motion fields. Based on the dynamic time warping (DTW) distance method, this paper discusses the application of similarity measurement in the similarity analysis of simulated multi-point ground motions and the actual seismic array records. Analysis results show that the DTW distance method not only can quantitatively reflect the similarity of simulated ground motion field, but also offers advantages in clustering analysis and singularity recognition of actual multi-point ground motion field.
A Grid-Based Method to Represent the Covariance Structure for Earthquake Ground Motion
Yingmin Li,Zheqian Wu,Huiguo Chen
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/420309
Abstract: Spatial variation of earthquake ground motion is an important phenomenon that cannot be ignored in the design and safety of strategic structures. However, almost all the procedures for the evaluation of variation assumed that the random field is homogeneous in space. It is obvious that reality does not fully conform to the assumption. How to investigate the inhomogeneous feature of ground motion in space is a challenge for researcher. A body-fitted grid-coordinates-based method is proposed to estimate and describe the local spatial variations for the earthquake ground motion; it need not to make the assumption that the random field of earthquake is homogeneous in space. An analysis of spatial variability of seismic motion in smart-1 array monitored in Lotung, Taiwan demonstrates this methodology.
Optimization of a new animal glue binder system cured by CO2 for use in foundry
Liu Weihua,Zhang Yilin,Li Yingmin
China Foundry , 2012,
Abstract: A new sand binder system cured by CO2 was prepared based on the animal bone glue. To overcome the disadvantages of animal glue such as agglomeration at room temperature, high energy consumption and low efficiency, an alkaline decomposition process was selected, and certain modifier was used to modify the performance of the animal glue binder. For the alkaline decomposition, NaOH was used as the catalyst with an addition of 4wt.% to the animal glue. A modifier was determined through the orthogonal experiment with a weight ratio of glycerin: glycol: dextrin: animal glue = 9:16:15:100, and the optimal modification reaction should be performed at 75 ℃ with a reaction time of 90 min. Ca(OH)2 was used as a promoter; the optimal CO2 gas flux blowing into the sand was 0.7 m3·h-1 for a duration of 60 s under the experimental conditions. Results show that an original strength above 0.7 MPa and a final strength about 4.2 MPa can be achieved, which could meet the requirement of rapid moulding and core-making for foundry. The new binder was characterized and analyzed by means of IR, and the modification and CO2-cured mechanisms of this animal glue binder were also discussed.
Study on binder system of CO2-cured phenol-formaldehyde resin used in phenol-formaldehyde resin used in foundry
Liu Weihua,Li Yingmin,Qu Xueliang
China Foundry , 2008,
Abstract: A new aqueous alkaline resol phenol-formaldehyde resin has been prepared from phenol and formaldehyde using NaOH as catalyst; the optimum synthetic process has been determined. With addition of some cross-linking agents, after passing carbon dioxide gas through the resin bonded sand, high as-gassed strength and 24 h strength are achieved. The bonding bridge of the resin bonded sand fracture has been analyzed by using SEM.
Renal neutrophil gelatinase associated lipocalin expression in lipopolysaccharide-induced acute kidney injury in the rat
Mei Han, Ying Li, Maodong Liu, Yingmin Li, Bin Cong
BMC Nephrology , 2012, DOI: 10.1186/1471-2369-13-25
Abstract: To induce acute renal injury, rats were treated with lipopolysaccharide (LPS, 3.5 mg/kg, ip), and the location of NGAL mRNA was evaluated by in situ hybridization. Quantitative RT-PCR was also used to determine the dynamic changes in NGAL, tumor necrosis factor α (TNFα) and interleukin (IL)-6 mRNA expression 1, 3, 6, 12, and 24 hours following LPS treatment. The correlation among NGAL, TNFα and IL-6 was analyzed. Urinary and plasma NGAL (u/pNGAL) levels were measured, and the relationship between humoral NGAL and NGAL expression in the kidney was investigated.Renal function was affected 3–12 hours after LPS. NGAL mRNA was significantly upregulated in tubular epithelia at the same time (P < 0.001). The course of NGAL mRNA upregulation occurred in parallel with renal damage. There was a transient increase in TNFα and IL-6 mRNA levels within 3 hours following LPS administration, and a strong correlation between TNFα and NGAL mRNA (r = 0.995, P <0.001) but not with IL-6 mRNA. Both pNGAL and uNGAL levels were markedly increased compared with those in the control group (P < 0.001); however, only uNGAL levels were correlated with NGAL mRNA (r = 0.850, P <0.001).NGAL upregulation is sensitive to LPS-induced renal TNFα increase and injury, which are observed in the tubular epithelia. Urinary NGAL levels accurately reflect changes in NGAL in the kidney.Acute kidney injury (AKI; or acute renal failure) is an important issue for patients during critical care, with sepsis being the most common trigger for AKI in the intensive care unit (ICU) [1-3]. Because of the lack of sensitive and specific biomarkers for indicating renal cell injury, the mortality rates for septic AKI have remained high [1,4]. Recently, genomic, transcriptomic, and proteomic techniques have identified neutrophil gelatinase associated lipocalin (NGAL) as an early marker of AKI [5,6]. NGAL has been investigated in a range of different clinical settings, such as contrast-induced nephropathy, AKI after cardiac s

Li Enliang,Wang Yingmin,

环境科学学报 , 1989,
Abstract: A general equation for describing the particle profile in filters based on mass conservation, Fick's first diffusion equation and Boussinesq's assumption and the resultant expressions were found. The new equation is much better than the previous theory.

Li Enliang,Wang Yingmin,

环境科学学报 , 1989,
Abstract: A general theory for collection efficiency of electrostatic precipitator was proposed and Deutsch's formula is only a specific case of which with the transverse turbulent diffusion coefficient approaching to indefinite, indicating that the theoretical maximum collection efficiency of the equipment could be higher than that suggested by Deutsch's method. Based on the theory,certain non-Deutsch phenomena can then be explained and gas flow quality is considered to be a significant factor affecting the collection efficiency.
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