Pulsed electrochemical micromachining accuracy predominantly depends on pulse duration. To obtain high accuracy, an expensive power source with ultra-short pulse duration is needed. An electrochemical micromachining method based on double feedback circuits is proposed in this work to achieve this aim. A positive feedback circuit plus a negative feedback circuit is used in the circuit of the pulsed electrochemical micromachining. Thus, the gains of the feedback circuits can control the pulse duration of the machining system. Experiments show that the machining resolution can be improved notably by an increase in the feedback gains. Using the method, one micro double cure beam is produced, and its accuracy gets to nanometer level under the condition of using an ordinary pulse duration power source.
The machining resolution of pulse electrochemical micromachining technology can be increased by shorting the pulse duration and changing the voltage signal waveform. With a triangular pulse, the energy per pulse was reduced by about two-thirds, and the machining gap was decreased by about eleven times compared to one with a rectangular pulse. Here, we put forward a real pulse waveform for electrochemical micro-machining. The pulse waveform is obtained by rectangular pulse plus differential circuits. The waveform can greatly reduce energy per pulse and surprisingly improve the precision of micro-electrochemical machining. The basic principle of the micromachining is analyzed. The equations of the machining accuracy and energy per pulse are deduced. Using the equations, the machining accuracy and energy per pulse as a function of the differential times of the differential circuits are calculated and compared with simulated and experimental results. Compared to the rectangular pulse, the energy per pulse for the waveform can be reduced by about six times and the machining gap was decreased can be improved by about 11 times. Using this method, some micro structures are produced and nanometer lever machining accuracy is realized which illustrates the proposed machining method.
To achieve the synchronous opetation and control of each node in manufacturing industry supply chain, the autonomous, adaptive, cooperative service agent is adopted to achieve the supply chain agility and reconfigurability. The interaction need of different types of nodes is studied, service agents and establish appropriate service contracts are established. A prototype of the steel industry agile supply chain system with web service technology is realized. The experiment shows that the method can support manufacturing supply chain enterprises to smartly conduct the rapid reconfiguration and adjustment of supply chain at a low cost.
Abstract Rapidly and randomly drifted reference frames will shorten the transmission distance and decrease the secure key rate of realistic quantum key distribution (QKD) systems. In this article, we present a free-running reference-frame-independent (RFI) QKD scheme, where measurement events are classified into multiple slices with similar estimated classification parameter. We perform the free-running RFI QKD experiment with a fiber link of 100 km and reference frame misalignment more than 29 periods in 50.7 h. A key rate as high as 742.98 bps is achieved at the total loss of 31.5 dB benefiting from both the new protocol design and the 80 MHz repetition rate system in use. Our system runs 50.7 h freely without any reference frame alignment. In the experiment, the misalignment variation rate tolerance of the experiment is 0.262 rad/s, and could be optimized to 1.309 rad/s. Therefore, our free-running RFI scheme can be efficiently adapted into the satellite-to-ground and drone-based mobile communication scenarios.
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