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The paper adopts modified carbon fiber with Meldrum's acid and silane coupling agent (KH-550), then add the modified carbon fiber to the paper based friction materials. The paper aims to explore the changes of modified carbon fiber in its surface structure and properties by electron microscopy and infrared spectral analysis, and the effect of anionic microparticle forming retention aid system comprised of lithium soapstone-cationic polyacrylamide (CPAM) on mechanical properties and retention of paper based friction materials. Compared with the addition of unmodified carbon fiber to paper based friction materials, the addition of modified carbon fiber with Meldrum's acid, silane coupling agent, Meldrum's acid and silane coupling agent enhance the tensile strength of paper based friction materials. The tensile index of paper based friction materials was separately enhanced by 64.87 %, 91.38 % and 28.88 %. Compared with the paper based friction materials without the anionic microparticle forming retention aid system, the basis weight of paper based friction materials increased by 13.97 %.

The dynamic process of cracks initiation in brittle materials during high speed cutting is primary for the analysis of material fracture mode and finished surface. Cast iron was considered in this paper and discrete element method (DEM) was employed to create a density packed bonded-particle model for studying its machining cracks. The numerical tests of split Hopkinson pressure bar (SHPB) and oblique plane impact were conducted to calibrate the dynamic behaviour of the model. The cutting simulations were carried out for a range of rake angles and cutting speeds. The results showed that both the processes of cracks initiation and the cracks distribution were different greatly under different cutting conditions and the cracks number increased with the cutting speed. In addition, within the detection zone in the model, the duration of crack initiation decreased dramatically with the increase of cutting speed in the lower range. But for the high speed cutting, the duration tended to be stable and was not affected by cutting speed and it was very close to the time of stress wave produced by cutting arriving at the zone. Furthermore, the stress state of particles’ connectors under the action of stress wave was analysed, which suggests that the stress wave is the key factor causing cracks initiation of brittle materials during high speed cutting.

A series of milling experiments with and without cutting fluid, arranged by uniform design method, were carried out on rotor material. The influence of cutting fluid on cutting force and surface roughness was explored and compared for the two kinds of conditions. The associated model was established between cutting force & surface roughness and cutting parameters according to the linear multivariable regression method. The results show that the cutting force deceases with the increase of the cutting speed or with the decrease of the feed per tooth and the cutting depth. Cutting fluid has little effect on cutting force, and for surface roughness, the influence of cutting fluid is uncertain.

In this research, the urea-formaldehyde prepolymer and multilayer hot-press drying was used to obtain modified wood. The timbers were compressed and dried by the multilayer hot-press drying kiln. The combination of chemical modification and hot-press drying can improve the drying rate, which can also enhanced the physical and mechanical properties. Based on the findings, the basic density of modified wood improved 25.2 %, the bending strength and the bend elastic modulus improved 15.6 % and 25.0 % respectively. The dimensional stability of the treatment appeared to be slightly higher than that of untreated samples under the same conditions for processing temperatures and times. The improving dimensional stability of wood mainly was attributed to the prepolymer that changes wood cell wall components such as the degradation of the hemicelluloses and cellulose during hot-press drying treatment. The XRD results indicated that the degree of crystallinity increased to 35.45 %from 31.25 %. The TGA results show that the degradation of the samples can be divided into two step, both of the maximum weight loss velocity temperature of the two step increased to 266 °C, 355 °C from 244 °C and 341 °C.

The aim of this work was to study the ability of NIR spectroscopy to determine holocellulose and alpha-cellulose contents in triploid clones of Populus tomentosa. For this purpose 90 trees with five families in different planting density grown in Shandong were analyzed. Calibration models were developed from wet chemical and NIR data using partial least squares (PLS) regression. High coefficients of determination (R2) and low root mean square errors of cross-validation (RMSECV) were obtained for holocellulose (R2 = 0.7805, RMSECV =0.652) and alpha-cellulose (R2 = 0.8702, RMSECV = 0.548) from wood meal. Prediction produced high correlation coefficients between laboratory and predicted values for holocellulose and alpha-cellulose contents, which R2 values are 0.7467 and 0.8505, and RMSEP are 0.993 and 0.553, respectively. This study showed that NIR analysis can be reliably used to predict holocellulose and alpha-cellulose contents in triploid clones of Populus tomentosa.

A preparation method of modifier with low molecular weight and high reactivity is presented. This modifier （called KFK in lab）can impregnate into polar wood along trachea from the ends with pressurized impregnation method. In the following heating and pressing processes of the polar wood, the KFK polymerizes, and it enhances stability and strength of the wood. It showed that the favorable conditions for synthetic reaction of the KFK are: molar ratio of U and F, 1:1; reaction temperature, 20°C; reaction time, 3 hours; dosage of ignition primer A: 5%. Results from test showed the degree of crystallinity tested by XRD were 30%, 32% in different dosage of the modifier. Utilizing a combination of low molecular weight resin impregnation and pressing resulted in a density increase of KFK resin-treated wood from 0.214 to 0.268g/cm3. At the same time, the Young’s modulus and bending strength increased from 1.407GPa to 1.759GPa and 64MPa to 74.5MPa, respectively. It can be concluded that the effective utilization of KFK resin impregnated in polar wood is a promising technique for the production of high-strength in the drying and pressing processing.