- 标题
- 摘要
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- 实验方案
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A highly independent multiband bandpass filter using a multi-coupled line stub-SIR with folding structure
摘要： The main problem in designing a multiband bandpass filter (BPF) is making each passband response highly independent, where each bandwidth of multiband BPF can be controlled and adjusted separately. To overcome this problem, this paper proposes a highly independent multiband BPF based on a multicoupled line stub-SIR with a folding structure. The proposed multiband BPF is constructed as a multicoupled line to generate a highly independent inter passband. Moreover, the multiband performance is produced separately and independently by using three sets of resonators: resonator A1/A2 (RA1 and RA2), resonator B1/B2 (RB1 and RB2), and resonator C1/C2 (RC1 and RC2). The three passband frequencies can be independently arranged and designed. To miniaturize the multiband BPF, a folding structure is also proposed. As a result, the multiband BPF has a compact size that is reduced by over 61.29 % compared to previous structures. The even-odd excitation model and the equivalent circuit model are used to analyze the multiband BPF structure. This BPF is designed for GPS applications at 1.57 GHz, WCDMA (3G) at 1.8 GHz, WLAN (WiFi) at 2.4 GHz, LTE (4G) at 2.6 GHz, and 5G communication at 3.5 GHz. To evaluate and validate the proposed structure of the multiband BPF, the circuits are fabricated and tested. The simulated and measured results of the multiband BPF show good agreement. In conclusion, the proposed multiband BPF structure has a highly independent inter passband response and a compact size.
关键词： highly independent,Compact,multiband BPF,folding structure
更新于2025-09-23 15:19:57
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Source-device-independent heterodyne-based quantum random number generator at 17 Gbps
摘要： Random numbers are commonly used in many different fields, ranging from simulations in fundamental science to security applications. In some critical cases, as Bell’s tests and cryptography, the random numbers are required to be both private and to be provided at an ultra-fast rate. However, practical generators are usually considered trusted, but their security can be compromised in case of imperfections or malicious external actions. In this work we introduce an efficient protocol which guarantees security and speed in the generation. We propose a source-device-independent protocol based on generic Positive Operator Valued Measurements and then we specialize the result to heterodyne measurements. Furthermore, we experimentally implemented the protocol, reaching a secure generation rate of 17.42 Gbit/s, without the need of an initial source of randomness. The security of the protocol has been proven for general attacks in the finite key scenario.
关键词： quantum cryptography,source-device-independent,heterodyne detection,continuous variable,quantum random number generator
更新于2025-09-23 15:19:57
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Multiple Input Single Output Phase Retrieval
摘要： In this paper, we consider the problem of recovering the phase information of multiple sources from a mixed phaseless short-time Fourier transform measurement, which is called multiple input single output (MISO) phase retrieval problem. It is an inherently ill-posed problem due to the lack of the phase and mixing information, and the existing phase retrieval algorithms are not explicitly designed for this case. To address the MISO phase retrieval problem, a least-squares method coupled with an independent component analysis (ICA) algorithm is proposed for the case of sufficiently long window length. When these conditions are not met, an integrated algorithm is presented, which combines a gradient descent algorithm by minimizing a non-convex loss function with an ICA algorithm. Experimental evaluation has been conducted to show that under appropriate conditions the proposed algorithms can explicitly recover the signals, the phases of the signals, and the mixing matrix. In addition, the algorithm is robust to noise.
关键词： Short-time Fourier transform (STFT),Multiple input single output (MISO),Independent component analysis (ICA),Non-convex optimization,Phase retrieval
更新于2025-09-19 17:15:36
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Isotope shifts and band progressions in SO <sub/>2</sub> rovibrational energy levels: using quantum theory to extract rotational constants
摘要： We report the isotope shifts of the rotational constants and vibrational band progressions of the sulfur dioxide molecule (SO2), for all four stable sulfur isotopes32S,33S,34S, and36S. These are extracted from exact quantum theoretical calculations of the SO2 rovibrational energy levels, as reported in Chem. Phys. 450–451, 59 (2015) and Chem. Phys. 461, 34 (2015) and by fitting these levels to a J-shifting (JS)-type scheme, applied to a representative set of total angular momentum (J) values. The approach used to obtain the rotational constants is unusual in that it is derived directly from the quantum theoretical framework used for the earlier calculation, which gives rise to a flexible (i.e., vibrational- and rotational-state-dependent) but symmetric rotor description. The usual (Ka, Kc) rotational quantum numbers are thus replaced with a single body-fixed azimuthal rotation quantum number, K, with various strategies introduced a posteriori to address rotor asymmetry. The new model fits the numerically computed rovibrational levels well, over a fairly broad range of vibrational (v) and rotational (J) excitations. The computed rotational constants agree well with previously reported experimental values [J. Chem. Phys. 58, 265 (1973)]. The explicitly v- and J-dependent approach used here should thus prove valuable in broader contexts—e.g., for an analysis of self-shielding in sulfur mass-independent fractionation, even though the rovibrational levels themselves exhibit mass-dependent fractionation.
关键词： J-shifting,Self-shielding,Mass-independent fractionation,Rotational constant,SO2 isotopologue
更新于2025-09-19 17:15:36
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Tracking solar cell conversion efficiency
摘要： Keeping track of the rapidly improving solar cell performance is not as easy as it might seem. Martin Green describes the Solar Cell Efficiency Tables that have been providing 6-monthly updates of record solar cell performance since the 1990s. Solar cells have become the lowest-cost source of electricity in many countries because their price has dropped dramatically, thanks partly to enhanced energy conversion efficiency, which has improved across all solar cell technologies. For single cells, the efficiency is fundamentally limited by the Shockley–Queisser (SQ) limit of 33.8%, with the well-established GaAs and Si cells the closest to this limit. Particularly rapid progress is evident for perovskite and organic cells. The SQ limit can be exceeded by stacking cells from different materials, each converting part of the solar spectrum. Such multi-junctions already surpassed the SQ limit experimentally in 2009. However, measuring efficiency is more difficult than it might appear, and by the 1980s the solar cell community was calling for the ‘independent confirmation’ of cell results by a recognized test centre. In the 1990s, I started compiling the Solar Cell Efficiency Tables, with the aim of providing an authoritative summary of the progress and encouraging independent confirmation of results — which was a necessary condition for inclusion in the Tables.
关键词： conversion efficiency,independent confirmation,solar cell,multi-junctions,Shockley–Queisser limit
更新于2025-09-19 17:13:59
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Hyperthermia and Controllable Free Radicals Co-Enhanced Synergistic Therapy in Hypoxia Enabled by Near-Infrared-II Light Irradiation
摘要： Tumor cells metabolism and tumor blood vessels proliferation represent in a distinctive way compared to normal cells. The resulting tumor microenvironment will presents a characteristic of hypoxia, which greatly limits the generation of oxygen free radicals and affects the therapeutic effect of photodynamic therapy. Here, we developed an oxygen-independent free radicals generated nanosystem (CuFeSe2-AIPH@BSA) with dual-peak absorption in both near-infrared (NIR) regions and utilized it for imaging-guided synergistic treatment. The special absorption endows the nanosystem with high photothermal conversion efficiency and favorably matched photoactivity in both (I and II) NIR biological windows. Upon NIR light irradiation, the generated heat could prompt AIPH release and decompose, and then to produce oxygen-independent free radicals for killing cancer cells effectively. The contrastive research results show the enhanced therapeutic efficacy of NIR-II over NIR-I principally due to its deeper tissue penetration and higher maximum permission exposure benefited from longer wavelength. Hyperthermia effect and the production of toxic free radicals upon NIR-II laser illumination are extremely effective in triggering apoptosis and death of cancer cells in tumor hypoxia microenvironment. The high biocompatibility and excellent anti-cancer efficiency of CuFeSe2-AIPH@BSA allow it to be an ideal oxygen-independent nanosystem for imaging-guided and NIR-II-mediated synergistic therapy via systemic administration.
关键词： second near-infrared window,free radicals,photothermal,hypoxia,oxygen-independent,CuFeSe2
更新于2025-09-19 17:13:59
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Polarization-Independent Reconfigurable Graphene Gas Sensor Using Crescent Plasmonic Antenna
摘要： A polarization-independent gas sensor based on crescent plasmonic dipole antenna loaded with graphene monolayer is introduced in this paper for environment monitoring applications. Single, dual, and four arms crescent dipoles are designed, analyzed and investigated. The proposed gas sensor has reconfigurable absorption characteristics in the wavelength range from 900 to 1600 nm which covers the different gases responses. A parametric study on the effect of the sensor dimensions and polarization of the illuminated waves on the total absorption of different gases is investigated. A graphene monolayer is used to enhance the gas molecule absorption in its unbiased state. An enhancement of the total absorption cross section (ACS) values for n = 1.4 is 1.028 × 105 nm2 for the unloaded sensor case and is 1.77 × 105 for the graphene loaded sensor case. The unloaded graphene sensor sensitivity is 630 nm/RIU, and for the graphene loaded case is 677.5 nm/RIU. Dual-polarized crescent dipole consists of two orthogonal arms is designed to maintain the same sensitivity for x- and y-polarized E-field illumination. A polarization independent gas sensor consists of four crescents dipole arms rotated with 45° is explained. An enhancement of gas absorption is achieved by using a sensor array of four-arm dipole sensor. Different array sizes loaded with graphene monolayer are investigated. The total ACS peak value is 7.84 × 106 nm2 for 6 × 6 dipole array is obtained.
关键词： Gas sensor,Graphene,Sensing antenna,Polarization independent
更新于2025-09-19 17:13:59
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Near-Field Radio Holography of Slant-Axis Terahertz Antennas
摘要： Principal component analysis (PCA) and independent component analysis (ICA) for radiated emissions from printed circuits are critically intercompared, revealing similarities and differences of the extracted components between both methods. The input data in this analysis are measured wideband complex-valued magnetic radiated and evanescent fields with quasi-Gaussian spatial distributions. PCA and ICA lead to similar maps of their components when considered as spatial eigenmodes, but independent components exhibit simpler field structure than principal components.
关键词： stochastic fields,principal component analysis (PCA),uncertainty quantification,Independent component analysis (ICA),radiated emissions
更新于2025-09-19 17:13:59
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Graphene Fabrication by Using Femtosecond Pulsed Laser and Its Application on Passively Q-Switched Solid-State Laser as Saturable Absorber
摘要： This paper presents an independent operation of the rotor-side converter (RSC) and grid-side converter (GSC) for a doubly fed induction generator (DFIG)-based wind energy conversion system under unbalanced grid voltage conditions. In this paper, the RSC is controlled to achieve four different control targets, including balanced stator current, sinusoidal rotor current, smooth stator active and reactive powers, and constant DFIG electromagnetic torque. The GSC is commanded to keep the dc voltage at a constant value. Additional feedback compensators using resonant regulators for the RSC are employed, and the decompositions of the positive and negative sequence components and calculations of the rotor negative current references can be avoided. Another similar compensator is used in the GSC to suppress the dc voltage ?uctuates and remove the GSC reactive power oscillations without the stator or rotor power information. The proposed method can make the RSC and GSC available to an independent operation with a simple implementation for higher reliability. The experimental results demonstrate the effectiveness of the proposed control strategy for both the RSC and GSC under unbalanced grid voltage conditions.
关键词： wind energy conversion system (WECS),independent operation,unbalanced grid voltage,resonant regulator,Doubly fed induction generator (DFIG)
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Investigation of Accuracy of various STC Correction Procedures for I-V Characteristics of PV Modules Measured at Different Temperature and Irradiances
摘要： Principal component analysis (PCA) and independent component analysis (ICA) for radiated emissions from printed circuits are critically intercompared, revealing similarities and differences of the extracted components between both methods. The input data in this analysis are measured wideband complex-valued magnetic radiated and evanescent fields with quasi-Gaussian spatial distributions. PCA and ICA lead to similar maps of their components when considered as spatial eigenmodes, but independent components exhibit simpler field structure than principal components.
关键词： Independent component analysis (ICA),principal component analysis (PCA),radiated emissions,uncertainty quantification,stochastic fields
更新于2025-09-19 17:13:59