Guo ang Li

New Intelligent-Environment Wood-Based Materials

The objective of this paper is to apply the wood-based composite materials into the field of intelligent decorative materials or wooden crafts materials, and then improve peoples life quality in the micro-environment. We introduce photochromic materials and the micro-capsule technology, and bring them into the processing field of wood-based composite materials, which make us find a new thinking direction for high value-added wood-based products. So that wood will be efficient and rational use of meeting demands of domestic and international market for intelligent and environment-friendly high-grade raw materials.

New Method to Identify CT Saturation Based on EMD

Aiming at the problem that Current Transformer (CT) affects differential protection, this paper proposes a new method to identify CT saturation based on Empirical Mode Decomposition (EMD). Differential current can be decomposed into few Intrinsic Mode Functions (IMFs) by EMD. When CT is linear transfer, the current waveform is nearly a sine wave, and it only contains one dominant IMF. However, CT saturation leads to the distortion of secondary current which contains at least two dominant IMFs. From the defined projection area on t-axis of each IMF and the specific gravity coefficient, the number of dominant IMF can be got. Thus CT saturation can be identified. Theoretical analysis and simulation results show that this method can identify CT saturation of different degree. It is convenient to achieve and hardly to be affect by aperiodic component.

Preparation of Nano-CaCO3/Fast-Growing Poplar Composite by the Diffusion Method

This paper introduced gap filling mechanism of wood and inorganic composite and used the mechanism to optimize the wood properties of poplar. Through double diffusion method of the vacuum impregnation, CaCO3 and poplar composite was prepared. Using Sample characterization methods and performance indexes, prepared wood inorganic nanometer composite (WINC) was with hydrophobic and higher hardness.

New Method to Identify Sympathetic Inrush in Transformer Based on Hilbert Huang Transform

Sympathetic inrush may cause the mal-operation of differential protection. Aiming at this problem, based on the characteristic that sympathetic inrush contains a lot of aperiodic component and high harmonics, this paper proposes to use Hilbert Huang transform to identify sympathetic inrush. Firstly, the mathematical model of sympathetic inrush is established to analyze its characteristic. Then Hilbert transform is used to obtain harmonic contents of sympathetic inrush and internal fault current. According to the proportion of fundamental to current, sympathetic current can be identified and differential protection can be blocked. The simulation results show that this method has better reliability and sensitivity than the second harmonic restraint scheme. Besides, it has a good ability against TA saturation.

A New Method to Detect Harmonics and Inter-Harmonics Based on Hilbert Marginal Spectrum

Aiming at the problem that harmonic pollution is becoming more and more serious in power system, a new method to detect harmonics and inter-harmonics based on Hilbert marginal spectrum is proposed in this paper. Firstly, the original signal is decomposed into several Intrinsic Mode Functions through Empirical Mode Decomposition. Then Hilbert marginal spectrum is obtained through Hilbert Huang Transform. It contains the information of signal’s harmonics frequency and those amplitudes. Finally, both harmonics and inter-harmonics are detected by this method. Fourier transform lacks the ability of time-frequency analysis. Wavelet transform is affected by the selection of wavelet base. This method overcomes these shortages and can detect the component of each harmonic quickly and accurately. Simulation result verifies that this method can meet the requirement of voltage and current distortion detection in power system.

The Study on PF-CaCO3/Fast-Growing Poplar Composite

This paper introduced the preparation method of PF-CaCO3/fast-growing poplar composite. Adopting AFM, DSC and SEM samples characterization methods was to explore the intersolubility of this PF and nano-CaCO3. And WPG and contact angles of treated veneers were measured. The results showed that this treatment method improved greatly density and hydrophilic of poplar veneers.

Study of Synthesis of Nao-CaCO3 and Intermiscibility of PF and Nao-CaCO3

This paper introduced common special effects of nano-CaCO3 with nanometer materials and prepared nano-CaCO3 using the raw material, CaCl2 and (NH4)2CO3 and surfactant, appropriate organic matter. The intermiscibility of Phenolic resin and CaCO3 was preliminarily researched and the distribution, morphology and size and of nano-CaCO3 were characterized and analysed by sample characterization methods.

Preparing Phenolic Resin / Calcium Carbonate Nanocomposites by Polymerization In Situ

The objective of this paper is to use polycondensation in situ to prepare phenolic resin / calcium carbonate nanocomposites in alkaline catalyst. This paper explored the optimization time of produce in situ calcium carbonate making use of metathesis reaction in the system of phenolic resin condensation, and analyzed the effects of the added time on water dilution and solid content of phenolic resin / calcium carbonate nanocomposites. We obtained the optimum preparation process, which provided a good research base for studying further their performances.

Preparation of new Environmental Materials from Poplar Wood as Raw Material

The objective of this paper is to use the modified nano-calcium carbonate compositing directly or sol-gel compositing with poplar wood by the vacuum infusion methods to prepare new environmental materials. This paper introduces promotion effects of nano-technology on the development of fast-growing poplar wood, the problems and research of fast-growing poplar wood compositing with nano-materials. By preparing the new environmental materials, we implement the use of plantation timber to produce high value-added products, and the use of a variety of nano-technology to improve the performances of wood, and improve timber utilization.

Study on the Assessment of Urbanization Level Based on Set Pair Analysis

The method of Set Pair Analysis is to study the certain and uncertain relationship between the different things and the key of this method is to calculate the connection degree of these things. In order to assess the urbanization levels, this paper proposed a new method to establish the assessment standards according to the value of assess indexes. The urbanization level of Yangtze River delta cities was assessed by Set Pair Analysis, and the results calculated are generally consistent with Nonlinear Mapping Analysis and Factor Analysis. Set Pair Analysis can provide an effective solution to urbanization assessment. The proposed method of standards establishment and Set Pair Analysis can also be used in other areas without unified assessment standards.