Search

In this research, a regioregular poly (3-alkylthiophene) derivative had been synthesized via the post-polymerization functionalization, poly (3-hexylamine thiophene), which are soluble in water and water miscible solvents such as methanol, DMSO. The suitable energy level, good thermal stability and water/alcohol solubility of polymers which promising applied in polymer solar cells and processed by water or environmental-friendly solvents. In blend of functionalization polymers and fullerene derivative potassium [6,6]-phenyl-C61-butyrate shows significant UV absorption decay phenomenon and occur precipitates follow with time increase. To further investigate the mechanism of composite, FT-IR analysis and TEM investigate were used, the polymer would be bonded with carboxyl of fullerene derivative via hydrogen bonding in the carboxyl region and TEM images demonstration the mixture that be able to self-assembly a interpenetrating network composite.

Tag collision problems seriously affected the performance of the RFID system. In order to solve this problem, we proposed an improved Recession Binary Tree Algorithm to avoid duplication and redundancy search, so that system throughput can substantial increased in the case of there have large quantities of labels.

Coal bumps happened many times in mining at No.5 seam of Tangshan coal mine. Strengthen the roadway’s support of working face can effectively reduce disaster losses. With the research background of the 3654 working face, the mine pressure monitoring for the existing support form of roadway has been carried on. Perform a numerical simulation for the original roadway support, base on the in-situ stress and physical and mechanical characteristics of surrounding rock in experimental; study the impact of the stability of roadway’s surrounding rock, while the space change of trellis and change of supporting intensity; optimizing the original support form, so as to maximum reducing the impact of the coal bumps.

Traditional trellis support was mainly used in deep mining roadway of Kailuan group. With the increase of mining depth, section of roadway and deformation of surrounding rock also increased gradually. As a passive support ways of roadway, trellis support had been unable to meet the requirements of high yield and high efficiency comprehensive mechanized mining. Therefore, anchor bolt supportis in urgent need to turn passive support into active support and to ensure the safety and the stability of surrounding rock of roadway, meanwhile, the cost saving and boosting yield was made sure. This paper is based on the physical and mechanical parameters of coal seam roof and floor of working face 1357w, numerical simulation method was took, and the parameters of anchor bolt support suitable for the roadway with working face were also studied. The result of study could provide theoretical basis for later projects.

The instability failure of coal and rock mass occur frequently in deep mining. However, this destruction occurs with abnormal intensity and suddenness, with hardly any obvious macro precursors. The ability to extract this precursory information and make certain the relationship among the parameters is therefore important. During the process of instability and failure of coal samples, the evolution characteristics of deformation field were monitored by digital image correlation system. Base on the researches, the appearance of the deformation localization band could be divided into three time periods for the samples which all had splitting failure. During period I, the relative sliding component increased rapidly. During period II, the relative tension component increased rapidly. During period III, both the relative tension and relative sliding components increased rapidly.

This paper proposes a communication scheme for heterogeneous wireless and wired sensor networks. In the scheme, through a common protocol to shield the differences of different types of wireless-wired networks, to realize the mobility management for heterogeneous wireless and wired network environment. In addition, access technology of the second layer can be shielded, and provided a unified interface for upper protocol layers. From the theoretical and simulative perspectives, the paper analyzes the performance parameters, including the mobile function, throughput capacity, energy consumption and network lifetime, and the analytical results show that the performance of the scheme is better than other mobility management scheme.

Effect of Y2O3 on the viscosity and Crystallization of of borosilicate glass at high temperature was investigated at high temperature. Melt viscosity as a function of temperature was determined by using a rotating spindle viscometer. Liquidus temperature was determined by the Gradient Furnace Method. The results show that the viscosity decreased as a function of Y2O3 content. The activation energy of glass without Y2O3 is about 110.3 kJ·mol-1 and the activation energy increases with the Y2O3 addition up to the 2 wt%. At 2 wt% Y2O3, the specimen shows the maximum activation energy value of 112.6 kJ·mol-1. As Y2O3 content increase, the activation energy decreases. The fiber-forming temperature of glass without Y2O3 is about 1342 oC and the fiber-forming temperature increases with the Y2O3 addition up to the 2 wt%. At 2 wt% Y2O3, the sample shows the maximum activation energy value of 1370 °C. When Y2O3 content increase, the fiber-forming temperature decreases. The liquidus temperature of glass decreases from 1313 °C to 1023 °C when Y2O3 content increases from 0 wt% to 6 wt%. The difference between the fiber-forming and the liquidus temperatures of glass increases from 30 oC to 336 °C when Y2O3 content increases from 0 wt% to 6 wt%.

The present work describes a solution-liquid-solid (SLS) synthesis route for the preparation of CdSe nanocrystal quantum dots using the low-melting-point Bi nanoparticles as catalysts. UV-vis absorption spectra were used to determine the growth of CdSe cluster. The shape and size distribution of the CdSe QDs were determined by analysis of Transmission electron microcopy (TEM) images. A peak wavelength of 399nm in the absorption spectra on day 5 indicated that the CdSe cluster formed. TEM micrographs showed that CdSe QDs had a relatively narrow distribution of QD size, and the diameter of CdSe QDs was about 4 nm. Our preliminary results illustrated that smaller size of CdSe QDs could be prepared by SLS method and it was small enough for bioimaging applications.

The system for well-logging data designed for data files unified management, can offer a function based on data query and download, also can offer instant replays for data curves. This system contains some functions following that format converting, uploading, query, download and preview for well-logging data curves. All system is designed by software Delphi GDI+.

To expand the extent of conjugation with biologically active molecules (biopolymers, peptides, drugs, etc.) and biomaterial substrates, we synthesized a serial of poly (ethy1ene glycol) (PEG) derivatives (PEG-2000-NH2, MPEG-1200-NH2, and APEG-1200-NH2) in three efficient steps. The end groups were characterized by 1H NMR spectroscopy.

Abatract: The poly (L-lactide)/laponite composite films are prepared by the method of solution blending with polylactide (PLA) and laponite. The results show that when laponite content was lower than 0.2 %( mass w/w), laponite can be uniform dispersed in PLA and the composed material had good stability. Fourier transform infrared spectroscopy (FTIR) study demonstrates that PLA was successfully incorporated with laponite by Si-O bond. The mechanical measurement reveals that the tensile strength of PLA/laponite composite film has been increased with compared to pure PLA. The water contact angle (WCA) tests indicate that the hydrophobicity of the laponite modified PLA films can be improved. The present study reveals that the laponite as a complexing agent can improve the mechanical properties and hydrophilicity of PLA.

An engineering case based three stages teaching mode is presented by issue bring forward, question analyzes and problem solve. From the perspectives of teaching through case, constructivism, cognition psychology, authors analyzed the function of teaching mode in cognition process mode and its control rules, emotion stimulating, and knowledge constructing as well. With the help of teacher in implementation of case design and class organization in Modern Quality Engineering(MQE) teaching, the three stages teaching mode has shown a significant effect on approaching to the objectives of education and teaching in inspiring students to learn and apply knowledge, as well as develop their ability initiatively. The three stages teaching methodology can be used as a helpful reference for young teachers in teaching effect improvement further.

The mechanical alloying method process has been innovatively used to prepare Cu-Cr coating on the inner wall of steel pipe. The effect of the rotating speed on thickness, microhardness and friction coefficient of the Cu-Cr coating was investigated. The coating thickness was measured from all samples using optical microscope. The microhardness was analyzed by Digital Microhardness Tester. The friction coefficient was tested by high speed reciprocating friction testing machine. The results show that the coating thickness is 26, 29 and 31μm at the rotating speed of 200, 250 and 300 rpm. The microhardness of the Cu-Cr coating prepared at 200, 250 and 300 rpm are about 760, 780 and 830 Hv. The friction coefficient of the Cu-Cr coating prepared at 200 rpm are about 0.25, 0.40 and 0.38 at the frequencies of 3, 4 and 5 Hz. The friction coefficient of the Cu-Cr coating prepared at 250 rpm are about 0.30, 0.29 and 0.20 at the frequencies of 3, 4 and 5 Hz. The friction coefficient of the Cu-Cr coating prepared at 300 rpm are about 0.10, 0.13 and 0.09 at the frequencies of 3, 4 and 5 Hz.

This study was designed to comparative evaluate the chemical composition of the essential oil from leaf, aerial root, twig, root and bark parts of Ficus microcarpa L.f. (Moraceace). Gas chromatography (GC) and gas chromatography/mass spectrometry (GC–MS) analyses of the oils revealed the presence of 6, 6, 5, 5 and 5 compounds in the essential oils obtained by hydrodistillation from different parts, respectively. The total yield of the volatile fractions was subsequently 1.89%, 0.87%, 1.27%, 0.97% and 0.71%. Higher amounts of aliphatic acids were found to compose a major chemotype in diverse parts of the plant. n-Hexadecanoic acid, elaidic acid and linoleic acid were the main and common component of all the essential oils totally attaining in average 74%, 87%, 56%, 46% and 88%, independently. In addition, some pharmaceutical components such as elaidic acid, linoleic acid and squalene were discovered. The study offers theoretic basis for utilization of the traditional folk herb F. microcarpa.

This study was designed to comparative evaluate total flavonoid contents (TFC) in leaf, aerial root, twig, root and bark parts of Ficus microcarpa L.f. (Moraceace). Ultrasonic-assisted extraction was adopted using benign solvent: ethanol and water to determine the extraction efficiency under the condition of ethanol concentration 40%, solid/liquid ratio of 1:25, extraction time 35 min and extraction temperature at 60 °C. According to the experimental results, the TFC values varied considerably and the extraction yield of 2.67±0.02%, 3.70±0.043%, 2.99±0.04%, 6.56±0.83% and 4.26±0.18% were obtained from different parts, respectively. The root part was characterized as containing a high amount of flavonoids, which might be the active compounds responsible for the pharmaceutical properties of the plant. The study offers theoretic basis for further utilization of the traditional folk herb F. microcarpa.

The linear model state equation of single-machine infinity bus power system with SVC was gotten by feedback linearization technology. The SVC fuzzy sliding mode controller was designed for this model. In order to adjust the controller outputs, the value and its derivative of sliding mode switching function were chosen for fuzzy controller inputs. The simulation shows that the SVC controller effectively improves the quality of power response, and settles power oscillations quickly when a disturbance occurs.

The digital campus project has become an important part of the campus information construction. This paper proposes a realization plan of information platform of deep development and utilization for digital campus based on Web Services and SOA on the analysis of problems of digital campus construction. It introduces the platform based on SOA and the realization of data exchange platform facing Web, and provides the example for service encapsulation. The whole plan with good encapsulation, expansibility and loose coupling solves the problem of utilization and sharing of campus resources.