A 3D nano-displacement measurement method,where the difference in phase between the beams in a four-beam laser interference is changed,is proposed.Simulation results demonstrate that the variation of phase difference ...A 3D nano-displacement measurement method,where the difference in phase between the beams in a four-beam laser interference is changed,is proposed.Simulation results demonstrate that the variation of phase difference causes the deviation of the interference pattern in the laser interference system.Based on this theory,we design and build a four-beam laser interference system.The corner cube prism in the optical path is shifted,and the phase of the beam is changed by applying different voltages to a piezoelectric stage.The phase difference is obtained by analyzing the lattice pattern with subpixel precision,and then the displacement is determined by correlation operation.The experimental measurement results are consistent with the theoretical analysis,thereby verifying the feasibility of this measurement method.展开更多
对西安南—宝鸡750 k V、西安南—户县330 k V混压同塔四回线路投运后的不平衡电流进行了计算与分析,结果表明线路采用的四回杆塔结构对750 k V线路的不平衡度影响较小,对330 k V线路的不平衡度影响较大,并且在计算分析的基础上给出了75...对西安南—宝鸡750 k V、西安南—户县330 k V混压同塔四回线路投运后的不平衡电流进行了计算与分析,结果表明线路采用的四回杆塔结构对750 k V线路的不平衡度影响较小,对330 k V线路的不平衡度影响较大,并且在计算分析的基础上给出了750 k V、330 k V合理的相序布置。展开更多
Free gas saturation is a key parameter for calculating shale gas reserves.The complex conductivity mechanism of shale reservoirs restricts the application of Archie's formula and its extended form for the evaluati...Free gas saturation is a key parameter for calculating shale gas reserves.The complex conductivity mechanism of shale reservoirs restricts the application of Archie's formula and its extended form for the evaluation of free gas saturation.Instead,a number of non-resistivity-based saturation evaluation methods suitable for shale gas reservoirs have been established,including core calibration(TOC method,clay content method),gas porosity cutoff,excavation effect and four-pore modeling.These methods,together with adsorbed phase porosity correction,are used to calculate the free gas saturation.These methods are applied to shale reservoirs of the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation in the Sichuan Basin,southwestern China to test their applicability and accuracy.The results,when compared with measured data from core samples,show that the TOC-based core calibration is more accurate in evaluating free gas saturation in the entire shale gas interval,which is of great significance to the calculation of shale gas reserves.展开更多
In this paper,we propose and demonstrate simultaneous phase regeneration of four different channels of QPSK signal based on phase sensitive amplification.The configuration can be divided into two parts.The first one u...In this paper,we propose and demonstrate simultaneous phase regeneration of four different channels of QPSK signal based on phase sensitive amplification.The configuration can be divided into two parts.The first one uses four wave mixing in high nonlinear fiber(HNLF)to generate the corresponding three harmonic conjugates precisely at the frequency of the original signals.The other one uses optical combiner to realize coherent addition which is aimed at completely removing the interaction in phase regeneration stage.The simulation results suggest that this scheme can optimize signal constellation to a large extend especially in high noise environment.Besides,optical signal to noise ratio(OSNR)can improve more than 3 dB while the bit-error-rate(BER)reaches 10 – 3 with a constant white noise and 15° phase noise.展开更多
When applying Grover＇s algorithm to an unordered database, the probabifity of obtaining correct results usually decreases as the quantity of target increases. A four-phase improvement of Grover＇s algorithm is propos...When applying Grover＇s algorithm to an unordered database, the probabifity of obtaining correct results usually decreases as the quantity of target increases. A four-phase improvement of Grover＇s algorithm is proposed to fix the deficiency, and the unitary and the phase-matching condition are also proposed. With this improved scheme, when the proportion of target is over 1/3, the probability of obtaining correct results is greater than 97.82% with only one iteration using two phases. When the computational complexity is O（ √M/N）, the algorithm can succeed with a probability no less than 99.63%.展开更多
基金supported by National Key R&D Program of China(No.2023YFE0108900)Horizon Europe Program(L4DNANO No.101086227)+1 种基金Jilin Provincial Science and Technology Program(Nos.20210101393JC,20210101069JC,20210101038JC,2020C022-1,20190201287JC and 20190702002GH)“111”Project of China(No.D17017).
文摘A 3D nano-displacement measurement method,where the difference in phase between the beams in a four-beam laser interference is changed,is proposed.Simulation results demonstrate that the variation of phase difference causes the deviation of the interference pattern in the laser interference system.Based on this theory,we design and build a four-beam laser interference system.The corner cube prism in the optical path is shifted,and the phase of the beam is changed by applying different voltages to a piezoelectric stage.The phase difference is obtained by analyzing the lattice pattern with subpixel precision,and then the displacement is determined by correlation operation.The experimental measurement results are consistent with the theoretical analysis,thereby verifying the feasibility of this measurement method.
文摘Free gas saturation is a key parameter for calculating shale gas reserves.The complex conductivity mechanism of shale reservoirs restricts the application of Archie's formula and its extended form for the evaluation of free gas saturation.Instead,a number of non-resistivity-based saturation evaluation methods suitable for shale gas reservoirs have been established,including core calibration(TOC method,clay content method),gas porosity cutoff,excavation effect and four-pore modeling.These methods,together with adsorbed phase porosity correction,are used to calculate the free gas saturation.These methods are applied to shale reservoirs of the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation in the Sichuan Basin,southwestern China to test their applicability and accuracy.The results,when compared with measured data from core samples,show that the TOC-based core calibration is more accurate in evaluating free gas saturation in the entire shale gas interval,which is of great significance to the calculation of shale gas reserves.
基金the National Natural Science Foundation of China(NSFC)(Grant No.61871051).
文摘In this paper,we propose and demonstrate simultaneous phase regeneration of four different channels of QPSK signal based on phase sensitive amplification.The configuration can be divided into two parts.The first one uses four wave mixing in high nonlinear fiber(HNLF)to generate the corresponding three harmonic conjugates precisely at the frequency of the original signals.The other one uses optical combiner to realize coherent addition which is aimed at completely removing the interaction in phase regeneration stage.The simulation results suggest that this scheme can optimize signal constellation to a large extend especially in high noise environment.Besides,optical signal to noise ratio(OSNR)can improve more than 3 dB while the bit-error-rate(BER)reaches 10 – 3 with a constant white noise and 15° phase noise.
基金Supported by the National Basic Research Program of China under Grant No 2013CB338002the National Natural Science Foundation of China under Grant No 11504430
文摘When applying Grover＇s algorithm to an unordered database, the probabifity of obtaining correct results usually decreases as the quantity of target increases. A four-phase improvement of Grover＇s algorithm is proposed to fix the deficiency, and the unitary and the phase-matching condition are also proposed. With this improved scheme, when the proportion of target is over 1/3, the probability of obtaining correct results is greater than 97.82% with only one iteration using two phases. When the computational complexity is O（ √M/N）, the algorithm can succeed with a probability no less than 99.63%.
