For the low productivity in low alloy high tensile steel of thick plate, it is possible to realize robot arc welding through adopting double-sided arc welding which does not need back chipping. Off-line program and di...
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For the low productivity in low alloy high tensile steel of thick plate, it is possible to realize robot arc welding through adopting double-sided arc welding which does not need back chipping. Off-line program and distributed controlling were adopted to realize the integration of multiple welding methods, multiple tasks and multi-robot system. Instruction catalog was used to manage multi-robot instruction. The executive condition of instruction catalog was set to control the movement order between robots. Control center was developed to plan and manage the multi-task according to the welding technology and the executive condition of robots and realize the double-sided arc welding robot in thick plate.
Presented is a MEMS probe-card with ultra dense two dimensional (2-D) probe arrays for wafer-level IC test. About 110000 probe tips can be simultaneously fabricated in a 4-inch wafer, with the 2-D tip pitch as 240 mum...
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Presented is a MEMS probe-card with ultra dense two dimensional (2-D) probe arrays for wafer-level IC test. About 110000 probe tips can be simultaneously fabricated in a 4-inch wafer, with the 2-D tip pitch as 240 mum times 160 mum. The "hoe-shaped" microprobe structure is composed of one or two planar arms and an up-tilted tip, both of which are high-yield fabricated by metal micromachining techniques including electroplating. The measured spring constants for all the three types of designed probes agree well with the designed values. As both mechanical and electrical interconnections, the Sn/Ag solder-bumps feature excellent properties. The tested contact resistance values are always below 0.8Omega, while the current leakage between two adjacent probes is only 150 pA under 3.3 V.
A novel low-driven MEMS capacitive switch structure for microwave distributed phase shifter is presented based on the analysis of the operation principle. The driven voltage, response time, release time and vibration ...
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A novel low-driven MEMS capacitive switch structure for microwave distributed phase shifter is presented based on the analysis of the operation principle. The driven voltage, response time, release time and vibration modes of the capacitive switch are analyzed using the Intellisuitetrade software. The simulation results show the driven voltage of 2.5 V, the response time less than 30 us, the release time high than 40 us and vibration frequency high than 15 KHz. The microwave distributed phase shifter based on the novel MEMS capacitive switch structure takes on superior electromechanical performance and rapid response time by comparing with other phase shifters based on the common MEMS beam structure switches.
A two-stage subsurface-flow constructed wetland (SSFCW);combined with horizontal flow constructed wetland (HFCW) and vertical flow constructed wetland (VFCW) was established to investigate nutrients transfer in the ca...
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A two-stage subsurface-flow constructed wetland (SSFCW);combined with horizontal flow constructed wetland (HFCW) and vertical flow constructed wetland (VFCW) was established to investigate nutrients transfer in the carriers and the macrophytes. Under average temperature of about 24.8℃, the system operated in the hydraulic load of 0.3～0.4m3m-2d-1 and six dominant natural macrophytes conditions for eight months. The results demonstrated with horizontal direction of HFCW, the concentration of total nitrogen (TN) and total phosphorus (TP) decreased dramatically, and the correlation of nutrients and organics was significantly positive both in terms of nutrients concentration and the ratio of nutrients/MLSS. At vertical direction, from 5～15cm to 55cm, the nutrients concentration were obviously removed in HFCW and VFCW (260 mg (dm-3) and 510 mg (dm-3) of TN decrement as well as 340 mg(dm-3) and 750 mg(dm-3) of TP decrement). With the exception of TP rebound occurred in the bottom of HFCW. On the other hand, the distribution of TN in macrophytes was depended on the differences of the plant's organ and growing phase. The concentration of TN was higher in tender organs and seeds than in caudex and pedicel. The concentration of TP was greatly correlated to the species of macrophytes. Environmental conditions induced the change of TP transformation.
The operating principle of the RF MEMS phase shifter is described. A novel design concept for dual-frequency RF MEMS phase shifter is proposed. By using network theory and CST microwave studio simulation tool, the pro...
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The operating principle of the RF MEMS phase shifter is described. A novel design concept for dual-frequency RF MEMS phase shifter is proposed. By using network theory and CST microwave studio simulation tool, the proposed RF MEMS phase shifter is modelled. Simulation results show that the proposed model has the return loss less than -10dB and the insertion loss more than -2dB in two operating frequencies, both of which are more than 1 GHz bandwidth. For one RF MEMS phase shifter, both 180-degree and 90-degree phase shift are realized.
In order to study the application of moderately halophilic bacterium in the hypersaline organic wastewater treatment, a moderately halophilic bacterium YS-1 was isolated from the salty water of a Ludaokou salina of We...
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In order to study the application of moderately halophilic bacterium in the hypersaline organic wastewater treatment, a moderately halophilic bacterium YS-1 was isolated from the salty water of a Ludaokou salina of Weihai in China. The polyphasic taxonomy study was conducted by identifying its morphological features by AFM by studying the features of culture, measuring the physiologic biochemical index and analyzing 16 S rDNA sequence homology. Phylogenetic analysis based on 16 S rDNA gene sequences showed that the closest relative of the strain was Halomonas sp. (AB167061). Experiments of intensifying hypersaline organic wastewater treatment processing in the SBR demonstrate a significant result. The wastewater salt content of initial wastewater was 12% and the initial CODcr was 1494 mg/L. After 72 h, the removal efficiency of CODcr achieved 90.0%, and after 120 h, it achieved 98.1%. The experiments also showed that the hypersaline organic wastewater treatment had the feasibility acclimating of halophilic bacteria and running of processing system.
In order to grasp the hydrophilic characteristics of mudstone in deep well, a self-developed soft rock hydrophilic experiment system is used to analyze the main influential factors, as well as SEM and X-ray techniques...
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In order to grasp the hydrophilic characteristics of mudstone in deep well, a self-developed soft rock hydrophilic experiment system is used to analyze the main influential factors, as well as SEM and X-ray techniques are applied. Based on a series of test results of diverse mudstone samples, the hydrophilic characteristics can be divided into two stages in time series, i.e. decelerating suction phase and uniform speed suction phase. According to the lnQ-lnt curve, where Q is the soakage and t is the soaking time, there are three kinds of curves: convex, concave and linear curves. Porosity, content and sort of minerals as well as clay occurrence are the main factors influencing the hydrophilic characteristics of mudstone. The soaking velocity or soakage of mudstone is directly proportional to its porosity, but is inversely proportional to the clay mineral content. The characteristic curve is also affected by the occurrence of clay mineral obviously.
Weld shape control is a fundamental issue in automatic welding. In this paper, a double side visual system is established for pulsed gas metal arc welding （ P-GMAW） , and both topside and backside weld pool images c...
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Weld shape control is a fundamental issue in automatic welding. In this paper, a double side visual system is established for pulsed gas metal arc welding （ P-GMAW） , and both topside and backside weld pool images can be captured and stored continuously in real time. By analyzing the weld shape regulation with the molten metal volume, some topside weld pool characterized parameters （WPCPs） are proposed for determining penetration in butt welding of thin mild steel. Moreover, some BP network models are established to predict backside Weld pool width with welding parameters and WPCPs as inputs.
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