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Search Results: 1 - 10 of 78954 matches for " Haiyan Chen "
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A Chinese Product Feature Extraction Method Based on KNN Algorithm  [PDF]
Biao Ma, Haiyan Chen
Open Journal of Social Sciences (JSS) , 2017, DOI: 10.4236/jss.2017.510012
The product feature set of online reviews obtained by the current product feature extraction methods has a low coverage rate of review information. In order to solve this problem, this paper proposes a method of product feature extraction based on KNN algorithm. We establish the classification system of product feature set firstly. Then we extract part of product features as training set manually, and according to similarity between words and the classification system, the product features of all reviews are quickly classified and extracted. At last, the PMI algorithm is used to filter and supplement it to improve the correct rate and the review information coverage rate of product feature set. Through the examples of online clothing reviews data in the Taobao platform, we prove that this method can effectively improve the review information coverage rate of product feature set.
The role of Tai Chi Chuan exercise on osteoporosis prevention and treatment in postmenopausal women
Haiyan Chen
Alternative Medicine Studies , 2011, DOI: 10.4081/ams.2011.e10
Abstract: Osteoporosis is a disease characterized by fragile bones and high susceptibility to low trauma fractures. Tai Chi, an ancient Chinese mind-body exercise that is reported to enhance muscle function, balance and flexibility, and to reduce pain, depression and anxiety, may safely and effectively be used to prevent or treat osteoporosis. The aim of this review is to evaluate the evidence for Tai Chi as an intervention to reduce rate of bone loss in postmenopausal women. A literature search on randomized controlled trials (RCTs), prospective cohort studies, and cross-sectional studies that included Tai Chi as an intervention, and had at least 1 outcome related to measurement of bone metabolism were identified in PubMed/Medline. Twenty-one controlled studies were identified in the database, which suggested Tai Chi slowed down the loss of bone mineral density in most postmenopausal women, improved balance and strength, relieves pain from arthritis, and improved mental strength so they can cope better with chronic diseases. Regular Tai Chi Chuan exercise is beneficial for retarding bone loss in the weight-bearing bones of postmenopausal women.
Numerical Simulations of the Equations of Particle Motion in the Gas Flow  [PDF]
Kelong Zheng, Liuxiang Zhang, Haiyan Chen
Open Journal of Applied Sciences (OJAppS) , 2013, DOI: 10.4236/ojapps.2013.31B1005

Under the assumption of considering the gravity and without gravity, two different acceleration models to describe particle’ motion in the gas flow are formulated, respectively. The corresponding numerical simulations of these models do not only show the trend of the velocity of the particle in different density and particle diameter sizes, but also the relationship between the maximum particle velocity and its diameter size.

Application of Carbon Dioxide and Polyacrylamide in Extracting Magnesium from Brine by Precipitation Method  [PDF]
Haiyan Hu, Lin Zhou, Qingguo Chen
Journal of Geoscience and Environment Protection (GEP) , 2016, DOI: 10.4236/gep.2016.47022
In this paper, carbon dioxide and polyacrylamide were used to improve the method to abstract magnesium from desalination brine. Experimental results showed that calcium ion in the desali-nation brine can be effectively removed using carbon dioxide, which thereby improves the purity and reaction efficiency of the magnesium hydrate precipitate. 0.1% - 0.2% PAM could help to promote the precipitation of magnesium hydrate colloid. And when hydroxyl anion was between 110% - 130% of theoretical amount, yield of magnesium hydrate exceeds 70% at standing time of 60 hours.
Secondary Structure Changes and Thermal Stability of Plasma Membrane Proteins of Wheat Roots in Heat Stress  [PDF]
Xin Zhao, Yong Shi, Li Chen, Fenlin Sheng, Haiyan Zhou
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.26096
Abstract: The wheat roots membrane separates the cell from the environment around it and encloses the cell contents. The pro-tein secondary structure and thermal stability of the plasma membrane of wheat root have been characterized in D2O buffer from 20°C to 90°C by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Quantitative analysis of the amide I band (1700 - 1600 cm–1) showed that the plasma membrane proteins contains 41% α-helix, 16% β-sheet, 18% turn, and 25% disorder structures at 20°C. At elevated temperatures from 25°C up to 90°C, the α-helix and the β-sheet structure unfold into turns and the disorder structure, with a major conformational transition occurring at 50°C. There is a rapid decline in H+-ATPase activity of plasma membrane from 35°C to 55°C and it remain very low level H+-ATPase activity of PM from 55°C to 90°C. Therefore the protein conformational transition was one of reasons of loses H+-ATPase activity of plasma membrane.
Research on Supercritical Methanol Treatment of Lignite  [PDF]
Haiyan Luan, Aiguo Wang, Qian Zhang, Fuming Chen
Advances in Materials Physics and Chemistry (AMPC) , 2012, DOI: 10.4236/ampc.2012.24B041

China has rich lignite reserves which are the proper resources to be liquefied. As its low coalification degree, much hydrogen is wasted. Solvent extraction can save hydrogen and improve its liquefaction performance. The paper studies supercritical methanol treatment of lignite with a device at high temperature and pressure. Experiments mainly focus on the effects of temperature, pressure, catalysts and pretreatment ways on the extraction rate. Results indicate that the extraction rate increases with raising of temperature and pressure below 330 ℃,10 MPa. When temperature exceeds 330 ℃, extraction rate decreases slightly.  After swelling pretreatment in methanol for 8 h, the lignite is treated for 60 min at 330 ℃,8.2 MPa with NaOH as catalyst(1%wt).  The weight ratio of methanol/ Xilinhaote lignite is 5/1.  Under these conditions, the extraction rate can reach 22.88%.


An Epsilon Half Normal Slash Distribution and Its Applications to Nonnegative Measurements  [PDF]
Wenhao Gui, Pei-Hua Chen, Haiyan Wu
Open Journal of Optimization (OJOp) , 2013, DOI: 10.4236/ojop.2013.21001

We introduce a new class of the slash distribution using the epsilon half normal distribution. The newly defined model extends the slashed half normal distribution and has more kurtosis than the ordinary half normal distribution. We study the characterization and properties including moments and some measures based on moments of this distribution. A simulation is conducted to investigate asymptotically the bias properties of the estimators for the parameters. We illustrate its use on a real data set by using maximum likelihood estimation.

2DGE-coomassie brilliant blue staining used to differentiate pasteurized milk from reconstituted milk  [PDF]
Yajun Wu, Ying Chen, Bin Wang, Haiyan Wang, Fei Yuan, Guiming Zhao
Health (Health) , 2009, DOI: 10.4236/health.2009.13024
Abstract: Differentiating pasteurized milk and reconsti-tuted milk by scientific approach was necessary to defend consumer from economic fraud of wrong labeling. In this paper 2DGE (2 Dimen-sional Gel Electrophoresis)-coomassie brilliant blue staining method was employed and sig-nificant color intensity changing was observed among raw milk, pasteurized milk, UHT milk and reconstituted milk. For example, the intensity of 10 protein spots including casein and lac-toglobulin reduced more than two folds from pasteurized milk to reconstituted milk. However, DIGE (Differential Gel Electrophoresis) assay showed that the majority protein remained simi-lar level from pasteurized milk to reconstituted milk. Therefore the color fading of coomassie brilliant blue stained 2D gels may be due to other biochemical reaction, such as Maillard reaction, instead of protein degradation. Stability of 2DGE pattern was confirmed by running six gels of the same sample in parallel and software analysis showed that all proteins were at similar level. Two commercialized pasteurized milk samples and one reconstituted milk sample were tested by 2DGE-coomassie blue staining method and re-constituted milk could be easily identified.
Nanoscale potassium niobate crystal structure and phase transition
Chen Haiyan,Zhang Yixuan,Lu Yanling
Nanoscale Research Letters , 2011,
Abstract: Nanoscale potassium niobate (KNbO3) powders of orthorhombic structure were synthesized using the sol-gel method. The heat-treatment temperature of the gels had a pronounced effect on KNbO3 particle size and morphology. Field emission scanning electron microscopy and transmission electron microscopy were used to determine particle size and morphology. The average KNbO3 grain size was estimated to be less than 100 nm, and transmission electron microscopy images indicated that KNbO3 particles had a brick-like morphology. Synchrotron X-ray diffraction was used to identify the room-temperature structures using Rietveld refinement. The ferroelectric orthorhombic phase was retained even for particles smaller than 50 nm. The orthorhombic to tetragonal and tetragonal to cubic phase transitions of nanocrystalline KNbO3 were investigated using temperature-dependent powder X-ray diffraction. Differential scanning calorimetry was used to examine the temperature dependence of KNbO3 phase transition. The Curie temperature and phase transition were independent of particle size, and Rietveld analyses showed increasing distortions with decreasing particle size.
Research on the Dynamic Data-driven Application System Architecture for Flight Delay Prediction
Haiyan Chen,Jiandong Wang,Lirong Feng
Journal of Software , 2012, DOI: 10.4304/jsw.7.2.263-268
Abstract: Flight delay prediction remains an important research topic due to the dynamics of the flight operating process. To solve this problem, a dynamic data-driven approach from the control area has been introduced, in which real-time data was collected and injected into the prediction process to get more accurate and reliable results. In the case of predicting the landing delays of consecutive arrival flights, delay propagation was analyzed to establish the corresponding state space model. Then, dynamic data-driven prediction architecture for flight delay and the prediction steps of on this architecture were presented. Several experiments were carried out on historic flight data to validate the performance of this solution. Results show that the accuracy is high, and not sensitive to the number of the predicted flights. Therefore, the solution has good predictive stability and reliability.
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