Advanced Materials Research Vols. 179-180

Abstract: The exchange bias phenomena in Tb/Cr films, where the Curie temperature (TC) of ferromagnetic Tb is much less than the Néel temperature (TN) of antiferromagnetic Cr, are systematically investigated. For the Tb/Cr bilayers, the exchange bias field HE changes from negative to positive as the temperature goes up. The unusual behavior of HE(T) is due to the spin-density waves spin structure in the Cr layer. For the Tb/Cr/Tb/Cr film, however, HE is negative throughout the temperature range in our experiment and its absolute value decreases monotonously with the temperature, which is ascribed to the coexistence of the interlayer coupling between Tb layers and the interfacial exchange coupling between Tb and Cr layers.

Abstract: Rotary power head is a key component of the cutting drill. After researching the current situation of the rotary power head, this paper proposed a new device called higher-order elliptic profile movable tooth transmission, and applied this device to the cutting drill, then designed a new rotary power head based on this device. The moving parts in a higher-order elliptic profile movable tooth transmission are self-balancing, such as the input shaft and the output one. The transmission can achieve the random difference of the teeth. A rotary power head of a drill with this transmission has many advantages, such as convenient disassembly or loading, large transmission torque, small radial size and the suitability for heavy loads. Finally, 3D model based on Solidworks2010 was established in this paper.

Abstract: A rotary power head is a key component of the cutting drill. In this paper, first, we researched the current situation of the rotary power head; Second, we proposed a new retard device called higher-order elliptic end surface movable tooth transmission, and then designed a new rotary power head based on this device. The moving parts in the transmission such as input and output shafts are self-balancing, so the transmission can achieve the random tooth difference. A rotary power head of a drill with this transmission has many advantages, such as convenient disassembly or loading, large transmission torque, small radial size and the suitability for heavy loads. Finally, 3D model based on Solidworks2010 was established.

Abstract: The rotary power head is the most important part of the cutting drill. After researching the status of the rotary power head, we invented a new decelerator—roulette curve profile movable tooth transmission, and applied it in cutting drill, we presented the rotary power head with roulette curve profile movable tooth transmission. The moving components, such as the input shaft and the output shaft, of the roulette curve profile movable tooth transmission are self-balance, so the transmission can bring about random tooth number difference. Analyzing the principle of the transmission, we create the three-dimensional modeling by using Solidworks2010. The rotary power head with the new transmission installed is convenient in assembling and disassembling, transferring bigger torque, having a relatively small radial dimension, suitable for heavy-loaded rock drill machine.

Abstract: For the huge scale of China's housing construction, our nation housing construction area into a year, than all the housing area developed into a year combined. Research shows that nearly 99% of the buildings have high energy consumption buildings, building energy related to the national development plan, the construction and transformation of energy-saving design is imperative. This article describes China building energy consumption, China building energy efficiency issues. And put forward China building energy-saving measures.

Abstract: Aiming at the requirements of saving energy and reducing emission on power plant, NOx emission model was built by SVM ,an effective learning tool, based on the analysis of the emission characteristics, and ACO was applied to optimize the model parameters. The model was tested on a 660MW power plant ,and the result indicated that SVM was a good tool for building emission model and had better generalization ability and higher calculation speed comparing with BP modeling approaches.

Abstract: Environmental risk study is very important because of existence of chemical substance that probably leads to a lot of harm. At present, the environmental risk has become science foundation and one of important basics of the environmental risk management and environmental decision-making.This paper based on the chemical properties of nitromethane including physical and chemical properties, toxicity, explosive harms characteristics are studied and puts forward some preventive measures.

Abstract: Fabrication pioneer production with lower cost and shorter cycle is a major mission for an enterprise, and rapid prototyping is a digital manufacture technology based on discrete stacking, which can meet the requirement. Rapid prototyping technology can be used to machine complex physical part directly from CAD data without any cutter or technical equipments. The paper summaries the working principle and compares the application fields, machining cost and process parameters for four typical rapid prototyping technology. Finally, the significant performance of rapid prototyping for modern industry is discussed, and the merits and faults is analysed. The investigation is beneficial for choosing an optimal forming process in industry.

Abstract: This paper presents the working principle of rapid prototyping technology based on fused deposition modeling (FDM) and summaries its technology features. The basic constitution of FDM system, such as mechanical device and control cell, are discussed, respectively. Selecting a deep groove ball bearing as experimental object and manufactured in the MEM320A rapid prototyping machine to demonstrate the FDM fabrication process. Investigate into the application of FDM on production design, function demonstration and biomedical engineering. Finally, the future development of FDM is prospected.

Abstract: In this paper, a robust image watermarking method in two-dimensional time-frequency distributions domain is proposed which is robust against geometric distortion. This watermarking is detected by a linear frequency change. The chirplet transformation is used to detect the watermark. The chirp signals are used as watermarks and this type of signals is resistant to all stationary filtering methods and exhibits geometrical symmetry. In the two-dimensional Radon-Wigner transformation domain, the chirp signals used as watermarks change only its position in space/spatial-frequency distribution, after applying linear geometrical attack, such as scale rotation and cropping. But the two-dimensional Radon-Wigner transformation needs too much difficult computing. So the image is put into a series of 1D signal by choosing scalable local time windows. The watermark embedded in the chirplet transformation domain. The watermark thus generated is invisible and performs well in StirMark test and is robust to geometrical attacks. Compared with other watermarking algorithms, this algorithm is more robust, especially against geometric distortion, while having excellent frequency properties.