Petroleum Drilling Techniques,Vol 46,No. 01
【Abstract】 A tracer, with its working performance affected greatly by the power supply, sometimes cannot collect a complete set of downhole data constrained by the source. In order to solve this problem, a power supply plan was designed using rechargeable lithium batteries as the source and the wireless charging technology to charge the battery. Through charge–discharge experiments, the relationship of charging voltage with transmission voltage, central distance of coils, and charging time, and the effects of high temperature on the discharge properties were researched. The research results showed that transmission voltage interacted with the central distance of coils. In theory, when the transmission voltage was much lower and the charging distance much longer, the charging voltage should have failed to reach the charging demands. However, on the contrary, the excessive charging voltage could result in an exploding battery due to overcharge. And, while a long charging time could assure good charging effects, the field operation duration should be further lengthened, because an overly brief charging time could also cause the inadequacy of charging; under high temperature, the lithium battery could experience accelerated discharge especially compared with batteries under normal temperature. Furthermore, the field downhole tests indicated that the tracer designed as the new power supply plan could collect all temperature data for the whole wellbore. Therefore, adopting the power supply plan in this type of tracers could solve the power supply problems.
Acta Optica Sinica,Vol 38,No. 09
【Abstract】 In the ultracold atomic system, to observe the parity-time (PT) symmetry with the gain balance requires controlled gain/loss of atom population and coherent coupling. We present a proposal to obtain an exponential growth of the atom population by dynamically controlling atom transport in a double-well trap on an atom chip. We numerically investigate the transport dynamics of the atomic ensemble between the sub-wells by using the direct simulation Monte Carlo method. It is found that the initial number and temperature of the atom cloud remarkably affect the transport performance, such as gain rate and transfer efficiency of the atom population in the target trap. Moreover, the effect of the lifting time of the left sub-well on the growing trend of the atom population in the right sub-well is analyzed in detail. Our strategy provides an achievable way for realizing a PT symmetric quantum system with gain/loss in ultracold atomic gas.
Chinese Optics,Vol 11,No. 03
【Abstract】 With excellent integrability and flexible operability, microfluidic chips have been developed rapidly. Among them, surface-enhanced Raman spectroscopy (SERS) has become a widely used detection technique due to its ultrasensitivity, unique fingerprint spectrum and narrow spectroscopic bands. The SERS microfluidic chip integrates the advantages of the SERS detection technology and the microfluidic chip. On one hand, it provides an efficient platform for the repeatability and reliability of the SERS detection method. On the other hand, it promotes function expansion for microfluidic chips. The SERS microfluidic chips have broad application prospects in the fields of biomolecule detection, cell capture and even tissue simulation. In this review, the principle of SERS is briefly introduced, and the construction of SERS microfluidic chip and its applications in biosensing and detection are emphatically summarized. Finally, the problems and development direction of the research are proposed.