摘要: This study aimed to investigate the stainless steel 316L processing by means of selective laser melting (SLM). The processing parameters under consideration included laser power (25-225 W), scanning speed (50-320 mm/s), and scan spacing (0.04 and 0.06 mm). Every processing was constrained the layer thickness as of 100 µm. All parameters were performed based on two experiments, line scanning and multiple layers scanning. Each of final workpieces was examined by visual inspection, density measurement, hardness, and built rate. From the experiments, the optimal processing conditions which produced the smooth tracks were obtained. The workpiece processed by this optimal processing condition presented quality characteristics with 97.6% density and 220±6 HV hardness.
摘要: Harmonics reduces the power factor of power supply system, and thereby reduces the power utilization factor of the power supply system. This paper introduces calculating and correcting of power factor in harmonic environment, and the methods of restraining harmonics.
摘要: The Ultimate goal of property management in intelligent community lies in how to provide efficient and swift service with high quality. With the development of Science and Technology, Automatic Ammeter Reading System (RAARS) has made great improvement on Stability, accuracy and intelligence. The system with Automatic Ammeter for remote Reading is connected to property management center through Acquisition memory attached on the Bus using advanced sensing, electronics technologies based on traditional Mechanical instruments. As a result, managers can get the meter readings of central air conditioning, water, electricity, and gas of users from computer automatically which greatly decrease the labor force of workers and improve the management of property managing department.
摘要: In virtue of having some periodicity in space, the fabric weave pattern can be recognized by using computer image process technology. Firstly, the reflected image and transmissive image of fabric were scanned and disposed. Then its image of two-dimensional power spectrum and image of autocorrelation were obtained by means of Fourier transform technology. Finally the fabric weave parameters can be calculated, including density of warp and weft, the size of warp and weft and the yarn numbers of weave repetition etc. Based on foregoing theory, this paper develops automatic recognition system of fabric weave parameters, which is worth of popularizing.
摘要: Combining with load bearing capacity tests, the laminated glass simply supported on four sides subjected to bending is analyzed using the finite element software ANSYS. Based on the theoretical and experimental deflection results, the accurate calculation model is established. In order to calculate the deflection of laminated glass subjected to short-time loading such as wind load based on different codes, the equivalent thickness of laminated glass based on Chinese code 2003 and European code is calculated, respectively. Finally, on the basis of many finite element analyses, load bearing capacity tests and code values, the formulas for calculating maximum deflectiont of four-sides supported laminated glass is revised in “Technical code for glass curtain wall engineering” (China) and corresponding correction coefficient is given.
摘要: In order to measure the signals greater than kHz such as vibration, high frequency strain and ultrasonic wave, a high-speed demodulation system for fiber Bragg grating（FBG）sensor based on tunable laser light was established. The measuring principle of the demodulation system was presented. The output curve and the wavelength measurement sensitivity were given by theoretical deduction. Then the 41434.71028 [Hz] vibration signal of ultrasonic cleaner was measured using this system. The system was compactly built with high demodulation speed and S/N(signal to noise ratio), meeting the special requirement for the high frequency signals measurement.
摘要: The capable of structures to absorb large amount energy are great interest in an effort to reduce the impact of collision. In this research, an experimental investigation was carried out to study the crashworthiness parameter and behavior of pultruded fiber E-glass/polyester composite tubes subjected to oblique load during progressive collapses. Two different pultruded wall thicknesses of 6 mm and 9 mm tubes were used and four load angles of 0˚, 5˚, 10˚ and 15˚ were selected to study their effect on crushing behaviors and collapse modes. All specimens were chamfer 45˚ on top end as purpose to work as a collapse trigger mechanism. The result showed that increasing the angle of loading will decrease the energy absorption of the structures. Pultruded tubes with 9 mm thick wall absorb more energy compare to 6 mm thick walls.
摘要: The paper introduces the working principle of a logging instrument, and according to the working principle and instrument’s function of two-way hydraulic control valve. Facing to the key problems of process equipment in the actual service and workflow, the structure of value was designed and optimized. At the same time, the logging instrument with a dual-channel and two-way hydraulic control valve is designed and processed. Meanwhile, we build an experimental platform and make the experiment according to principle of the instrument. The results show that the design of this dual-channel and two-way hydraulic control valve logging instrument met the work requirements, and it has high reliability in oil exploration, which could be promoted and used in logging areas.
摘要: Unseating prevention devices(UPD) are used to prevent relative great displacement between supper-structure and sub-structure, and to protect the super-structure falling down from piers as the support loss capacity. Unseating prevention devices are the ultimate security installment in the collapse-proof system when the highway bridges encounter rare earthquake or unexpected earthquake. Based on the relational design standards at home and abroad, the paper is emphasis on the time-history analysis for structure with cable-unseating prevention devices under rare earthquake. The analysis results obtained show that the collapse-proof effectiveness of unseating prevention devices and the variation law of collapse-proof changing with cable length and design displacement value. What’s more, under rare seismic, the rational unseating prevention devices can ensure the ultimate security of the structure, increase the integrity and anti-pushing rigidity of the structure, and make the seismic load to be well-distributed among the piers. As a result, the unseating prevention devices can effectively avoid girder falling in strong seismic, achieving no collapsing in strong seismic.
摘要: E-waste released from Television colour picture tube manufacturing process is hazardous in nature and its worldwide disposal has become major concern to safe guard the environment and ecology. The solid wastes generated from the picture tube manufacturing process contain significant quantity of compounds of lead, nickel, cobolt, iron etc. The presence of toxic substances and their characteristic nature made these wastes hazardous and pose serious problems in their disposal resulting in major environmental concerns. In the present study an attempt has been made to develop a new cost effective process for immobilizing and recycling e-waste released from electronic industry in developing non-hazardous building material using additives and binders. Detoxification /immobilization of e-waste was achieved in making composite products using cement and sand as additives through solidification/stabilization process. Further strength and stability of solidified composite products was achieved through curing process. The quality and suitability of the S/S cured composite products were tested and assessed for their Engineering properties (compressive strength, water absorption, density), Toxicity leachate characteristics, Mineralogical studies, Morphological studies for their use in engineering applications, application as construction materials like bricks, blocks, aggregates and confirmed their environmental significance.