Advanced Materials Research Vols. 760-762

Abstract: We used a simple low-temperature hydrothermal approach to synthesize Ag nanoparticles (NPs) and demonstrated their efficiency as organic molecule detectors in surface enhanced Raman Scattering (SERS). Using finite difference time domain simulation, we described an investigation on the distribution of electric fields amplitude of the neighboring Ag NPs. The enhanced electric field is confined at the interparticle gaps and the enhancement factor can be further increased with reducing the spacing between the NPs. The theoretical simulation demonstrated good consistency with the experimental measurement results, which predicts an electric fields amplitude enhancement of 115 at the center of NPs gap and an electromagnetic SERS enhancement of 10⁸. The evidence of clear correlations between SERS enhancement and morphology distribution offer a route to develop more effective SERS substrates.

Abstract: The ordinary laser etching on Al₂O₃ ceramic could bring many problems. Here introduced a new process named low-pressure water jet assisted laser etching on Al₂O₃ ceramic. The new composite process is much better than ordinary laser etching on Al₂O₃ ceramic. And the water jet can greatly reduce the thermal cracks and slag which improved the quality of the Al₂O₃ ceramic surface apparently. It also shows that the parameters of the laser have complex influences on the etching surface quality. Here introduces the method of orthogonal experiment to finish the experiment. Via this method can not only reduce the times of the experiment but also clearly reflect the optimization of the experimental parameters.

Abstract: This report presents the synthesis, growth, crystal structure determination and second-harmonic generation efficiency of nonlinear optical co-crystal 4-N, N-dimethylamino-4-N-methyl-stilbazolium (m-nitrobenzenesulfonate)_0.6I_0.4 (DSIMNS)_. It is co-crystal of two DAST (4-N,N-dimethylamino-4-N-methyl-stilbazolium tosylate) derivatives. X-ray crystallographic analyses revealed that the crystal structure of DSIMNS is monoclinic, with space group P2₁. Kurtz powder test has shown that DSIMNS exhibits a large second-harmonic generation efficiency 500 times of that of urea.

Abstract: We demonstrate that single crystalline ZnO nanowires with large length/diameter ratio are successfully grown on Si, glass, and Si with ZnO seed layer via simple thermal vapor deposition, without introducing any catalyst or additive. In this work, we study impact of growth conditions such as growth temperature, substrates, and ZnO seed layer on morphology and photoluminescence properties of ZnO nanowires, in terms of systematic characterizations. The investigations show that the growth temperatures have substantial effect on the morphology of ZnO nanowires, while substrates have low impact. And 700 °C is believed to be the optimized growth temperature among the series of temperatures. Moreover, ZnO seed layer plays an important role in the uniformity and reproducibility of ZnO nanowires growth. PL measurements for the ZnO nanowires exhibit two emission bands including a UV emission and a blue emission, respectively. Finally, the growth behavior of the ZnO nanowires is discussed based on the VS growth mechanism. Our resluts have made a positive progress toward improving control of the morphology of ZnO nanowires.

Abstract: Uniform Y₂O₃:Tb³⁺ nanowires with diameters of about 70 nm were fabricated using the anodic aluminum oxide template (AAO). The Y₂O₃:Tb³⁺ nanowires and Y₂O₃:Tb³⁺/AAO composite were characterized by using powder X-ray diffraction (XRD), scanning electron microscope (SEM) and spectrofluorometer techniques. The Y₂O₃:Tb³⁺ nanowires are amorphous phase in symmetry as the annealing temperature was lower than 1000 °C. And the cubic Y₂O₃: Tb³⁺ nanowires were formed partly as the annealing temperature approached to 1000 °C. The spectral measurements indicate that the excitation and emission intensity increased with the increasing annealing temperature as well as annealing time. The lifetime of ⁵D₄-⁷F₅ transition becomes longer with the increasing annealing temperature and time in Y₂O₃:Tb³⁺/AAO composite.

Abstract: In this paper, traditional data transmission strategy of lighting control system is compared. Defects are analyzed. Through Petri based formal verification, the Petri model of SDT is built. Rationality of the model and SDT is validated, which proves that SDT is reachable. Reliability and circulation characteristics of the protocol are also proved.

Abstract: This paper develops a remote monitoring system of water injection well based on TWACS (Two Way Automatic Communication System), the system is comprised of remote monitoring terminal, communication master station and water injection well data back-stage management center. This system, which is based on TWACS, can realize the datas remote multi-channel parallel transmission and monitoring. Through the field experiment shows that the system has a small investment and no signal blind area, it is well suited in oilfield distribution.

Abstract: Well monitoring system based on power line transmission information has low cost, can realize to span transformers through the area of long distance, as well as in remote areas does not exist blind area, the paper designs a kind of wells monitoring background management software based on the Labview. Due to the characteristics of well monitoring and power frequency communication technology, the labview reaches not only the data management, but also realizes to collect data for simulation and analysis of the channel. Wells monitoring background software based on labview not only realize data collection and management, but also realize the system equipment monitoring and debugging.

Abstract: Rotating target is the main equipment used to test tracking performance of electro-optics system indoor, but it can only simulate a single track, so a new dynamic tracking performance testing system is designed, which can offset the disadvantage of the rotating target. In this paper, the new testing systems basis structure is given, then the movement track theory model of the system is established, and the space relation between the testing system and the electro-optics system is deduced. At last, the movement track, tracking velocity and tracking acceleration is simulated through computer, the simulation results proved that the new testing system can simulate more movement track, make the multi-tracking velocity and multi-tracking acceleration realization, and can test electro-optics system more comprehensive.

Abstract: Failure and security risks of communication optical cable in electric power system caused by anomalous changing of strain have been investigated, the current situation of the strain monitoring system for optical cable of electric power system has been introduced, and the principle and features of measuring the strain by using fiber grating sensing technology have been presented. The new method that can be used in strain monitoring for communication optical cable of key position in electric power system has been put forward, and fiber grating sensor scheme has been designed. Finally, several key technical problems in its practical application have been analyzed in detail.