A compact variable optical attenuator, covering C and L bands with over 50 dB attenuation range, is realized using a single liquid crystal cell with a tilted fused silica coating compensating the cell's small resi...A compact variable optical attenuator, covering C and L bands with over 50 dB attenuation range, is realized using a single liquid crystal cell with a tilted fused silica coating compensating the cell's small residual birefringence.展开更多
To address issues such as poor initial population diversity, low stability and local convergence accuracy, and easy local optima in the traditional Multi-Objective Artificial Hummingbird Algorithm (MOAHA), an Improved...To address issues such as poor initial population diversity, low stability and local convergence accuracy, and easy local optima in the traditional Multi-Objective Artificial Hummingbird Algorithm (MOAHA), an Improved MOAHA (IMOAHA) was proposed. The improvements involve Tent mapping based on random variables to initialize the population, a logarithmic decrease strategy for inertia weight to balance search capability, and the improved search operators in the territory foraging phase to enhance the ability to escape from local optima and increase convergence accuracy. The effectiveness of IMOAHA was verified through Matlab/Simulink. The results demonstrate that IMOAHA exhibits superior convergence, diversity, uniformity, and coverage of solutions across 6 test functions, outperforming 4 comparative algorithms. A Wilcoxon rank-sum test further confirmed its exceptional performance. To assess IMOAHA’s ability to solve engineering problems, an optimization model for a multi-track, multi-train urban rail traction power supply system with Supercapacitor Energy Storage Systems (SCESSs) was established, and IMOAHA was successfully applied to solving the capacity allocation problem of SCESSs, demonstrating that it is an effective tool for solving complex Multi-Objective Optimization Problems (MOOPs) in engineering domains.展开更多
To study the complex internal flow field variation and output characteristics of a variable base radius scroll expander,this paper uses dynamic mesh techniques and computational fluid dynamics(CFD)methods to perform t...To study the complex internal flow field variation and output characteristics of a variable base radius scroll expander,this paper uses dynamic mesh techniques and computational fluid dynamics(CFD)methods to perform transient numerical simulations of a variable base radius scroll expander.Analysis of the flow field in the working cavity of a variable base radius scroll expander at different spindle angles and the effect of different profiles,speeds and pressures on the output characteristics of the scroll expander.The results of the study show that due to the periodic blocking of the inlet by the orbiting scroll,the fluid hits the internal walls of the expander at different flow rates,with excessive mechanical losses,resulting in an uneven distribution of the internal flow field.At the same temperature,pressure and scroll plate diameter,the variable base radius scroll expander increases the output torque by 0.046 N·m,the output power by 9.634 W and the isentropic efficiency by 3.8%compared to the fixed base circle scroll expander.As the speed is inversely proportional to the output torque,the isentropic efficiency of the expander tends to increase and then decrease as the speed increases.The density of the fluid is directly proportional to the pressure over a range of pressures.As the pressure increases from 0.6 to 0.9 Mpa,the average mass flow rate and isentropic efficiency increase by 0.02357 kg/s,and 6.61%,respectively.展开更多
Nuclear magnetic resonance gyroscopes （NMRGs） are a kind of rotation-speed sensor that senses the angular velocity by measuring a frequency shift in the Larmor pre- cession of the nuclear spin in a constant magnetic...Nuclear magnetic resonance gyroscopes （NMRGs） are a kind of rotation-speed sensor that senses the angular velocity by measuring a frequency shift in the Larmor pre- cession of the nuclear spin in a constant magnetic field.展开更多
We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the propos...We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ~ 35 dB). The generated PDL value could be maintained within ±0.02 dB for >70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520 nm~ 1590 nm.展开更多
An improved unslotted CSMA/CA MAC scheme of HORNET based on the node structure with variable optical buffer is reported. It can be used for transmitting high effectively all variable IP packets in the WDM network.
Polychlorinated dibenzothiophenes（PCDTs） are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 ...Polychlorinated dibenzothiophenes（PCDTs） are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 PCDTs congeners at the B3LYP/6-31G＊ level of theory.By means of the VSMP（variable selection and modeling based on prediction） program,one optimal descriptor（molecular polarizability,α） was selected to develop a QSRR model for the prediction of gas chromatographic retention indices（GC-RI） of PCDTs.The estimated correlation coefficients（r2） and LOO-validated correlation coefficients（q2）,all more than 0.99,were built by multiple linear regression,which shows a good estimation ability and stability of the models.A prediction power for the external samples was validated by the model built from the training set with 17 polychlorinated dibenzothiophenes.展开更多
文摘A compact variable optical attenuator, covering C and L bands with over 50 dB attenuation range, is realized using a single liquid crystal cell with a tilted fused silica coating compensating the cell's small residual birefringence.
基金by National Natural Science Foundation of China(62373142,62033014)Natural Science Foundation of Hunan Province(2025JJ70017,2022JJ50074).
文摘To address issues such as poor initial population diversity, low stability and local convergence accuracy, and easy local optima in the traditional Multi-Objective Artificial Hummingbird Algorithm (MOAHA), an Improved MOAHA (IMOAHA) was proposed. The improvements involve Tent mapping based on random variables to initialize the population, a logarithmic decrease strategy for inertia weight to balance search capability, and the improved search operators in the territory foraging phase to enhance the ability to escape from local optima and increase convergence accuracy. The effectiveness of IMOAHA was verified through Matlab/Simulink. The results demonstrate that IMOAHA exhibits superior convergence, diversity, uniformity, and coverage of solutions across 6 test functions, outperforming 4 comparative algorithms. A Wilcoxon rank-sum test further confirmed its exceptional performance. To assess IMOAHA’s ability to solve engineering problems, an optimization model for a multi-track, multi-train urban rail traction power supply system with Supercapacitor Energy Storage Systems (SCESSs) was established, and IMOAHA was successfully applied to solving the capacity allocation problem of SCESSs, demonstrating that it is an effective tool for solving complex Multi-Objective Optimization Problems (MOOPs) in engineering domains.
基金funded by the Provincial Natural Science Foundation of Shandong,Grant Number ZR2021ME233,ZR202103040075funded by the Qingdao Emerging Industry Cultivation Program,Grant Number 22-3-4-xxgg-7-gx.
文摘To study the complex internal flow field variation and output characteristics of a variable base radius scroll expander,this paper uses dynamic mesh techniques and computational fluid dynamics(CFD)methods to perform transient numerical simulations of a variable base radius scroll expander.Analysis of the flow field in the working cavity of a variable base radius scroll expander at different spindle angles and the effect of different profiles,speeds and pressures on the output characteristics of the scroll expander.The results of the study show that due to the periodic blocking of the inlet by the orbiting scroll,the fluid hits the internal walls of the expander at different flow rates,with excessive mechanical losses,resulting in an uneven distribution of the internal flow field.At the same temperature,pressure and scroll plate diameter,the variable base radius scroll expander increases the output torque by 0.046 N·m,the output power by 9.634 W and the isentropic efficiency by 3.8%compared to the fixed base circle scroll expander.As the speed is inversely proportional to the output torque,the isentropic efficiency of the expander tends to increase and then decrease as the speed increases.The density of the fluid is directly proportional to the pressure over a range of pressures.As the pressure increases from 0.6 to 0.9 Mpa,the average mass flow rate and isentropic efficiency increase by 0.02357 kg/s,and 6.61%,respectively.
基金supported by the National Natural Science Foundation of China(Nos.61673041,61673041,and 61227902)the National High Technology Research and Development Program 863(No.2014AA123401)
文摘Nuclear magnetic resonance gyroscopes （NMRGs） are a kind of rotation-speed sensor that senses the angular velocity by measuring a frequency shift in the Larmor pre- cession of the nuclear spin in a constant magnetic field.
文摘We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ~ 35 dB). The generated PDL value could be maintained within ±0.02 dB for >70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520 nm~ 1590 nm.
文摘An improved unslotted CSMA/CA MAC scheme of HORNET based on the node structure with variable optical buffer is reported. It can be used for transmitting high effectively all variable IP packets in the WDM network.
基金Sponsored by the NSF of Guangxi Province (No. 2011XNSFA018059)Guangxi Key Laboratory Research Fund of Environmental Engineering and Protection Assessment (No. 0801Z026)+1 种基金Major Science of Water Pollution Control and Management (No. 2008ZX07317-02)the Guangxi Zhuang Autonomous Region Department of Education Research (No. 201010LX174) Funding
文摘Polychlorinated dibenzothiophenes（PCDTs） are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 PCDTs congeners at the B3LYP/6-31G＊ level of theory.By means of the VSMP（variable selection and modeling based on prediction） program,one optimal descriptor（molecular polarizability,α） was selected to develop a QSRR model for the prediction of gas chromatographic retention indices（GC-RI） of PCDTs.The estimated correlation coefficients（r2） and LOO-validated correlation coefficients（q2）,all more than 0.99,were built by multiple linear regression,which shows a good estimation ability and stability of the models.A prediction power for the external samples was validated by the model built from the training set with 17 polychlorinated dibenzothiophenes.
