- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tetramodal Imaging and Synergistic Cancer Radio-Chemotherapy Enabled by Multiple Component-Encapsulated Zeolitic Imidazolate Frameworks
摘要： The abundant species of functional nanomaterials have attracted tremendous interests as components to construct multifunctional composites for cancer theranostics. However, their distinct chemical properties substantially require a specific strategy to integrate them in harmony. Here, we report the preparation of a distinctive multifunctional composite by encapsulating small-sized semiconducting copper bismuth sulfide (CBS) nanoparticles and rare-earth down-conversion (DC) nanoparticles in larger-sized zeolitic imidazolate framework-8 (ZIF8) nanoparticles, followed by loading an anticancer drug, doxorubicin (DOX). Such composites can be used for tetramodal imaging, including traditional computed tomography and magnetic resonance imaging and, recently, for photoacoustic imaging and fluorescence imaging. With a pH-responsive release of the encapsulated components, synergistic radio-chemotherapy with a high (87.6%) tumor inhibition efficiency is achieved at moderate doses of the CBS&DC-ZIF8@DOX composite with X-ray irradiation. This promising strategy highlights the extending capacity of zeolitic imidazolate frameworks to encapsulate multiple distinct components for enhanced cancer imaging and therapy.
关键词： multifunctional,zeolitic imidazolate frameworks,tetramodal imaging,multiple encapsulation,synergistic radio-chemotherapy
更新于2025-11-14 15:24:45
-
Research on photo-radiation darkening performance of ytterbium-doped silica fibers for space applications
摘要： Yb3+/Al3+-doped and Yb3+/Al3+/P5+-doped silica fibers with almost identical Yb3+ doping concentrations were prepared using modified chemical vapor deposition methods. A harsh experimental environment for simultaneous photo-darkening (PD) and radio-darkening (RD) of an ytterbium-doped silica fiber (YDF) was established. The RD, PD, and photo–radio-darkening (PRD) of the YDF were characterized at two dose rates of 0.1 rad(Si)/s and 1 rad(Si)/s. The laser performances before and after the darkening process were tested under 974-nm pumping. The results demonstrated that the PD largely dominated the PRD kinetics of the YDF at a low dose rate (e.g., that in space) and that the PRD was not a superposition of RD and PD owing to the pump light bleaching if the induced loss was larger than the PD equilibrium level. The induced loss and defect types were investigated through absorption spectra and electron paramagnetic resonance. The results revealed that the P doping could enhance the PD, RD, and PRD resistances by inhibiting the formation of aluminum–oxygen hole centers.
关键词： photo-radio darkening,radio-darkening,photodarkening,defects in silica glass,ytterbium doped silica fiber
更新于2025-09-23 15:23:52
-
A Radio-Fluorogenic Polymer-Gel Makes Fixed Fluorescent Images of Complex Radiation Fields
摘要： We review the development and application of an organic polymer-gel capable of producing fixed, three-dimensional fluorescent images of complex radiation fields. The gel consists for more than 99% of γ-ray-polymerized (~15% conversion) tertiary-butyl acrylate (TBA) containing ~100 ppm of a fluorogenic compound, e.g., maleimido-pyrene (MPy). The radio-fluorogenic effect depends on copolymerization of the MPy into growing chains of TBA on radiation-induced polymerization. This converts the maleimido residue, which quenches the pyrene fluorescence, into a succinimido moiety (SPy), which does not. The intensity of the fluorescence is proportional to the yield of free-radicals formed and hence to the local dose deposited. Because the SPy moieties are built into the polymer network, the image is fixed. The method of preparing the gel and imaging the radiation-induced fluorescence are presented and discussed. The effect is illustrated with fluorescent images of the energy deposited in the gel by beams of X-rays, electrons, and protons as well as a radioactive isotope.
关键词： polymer gel dosimetry,radio-fluorogenic co-polymerization,radio-fluorogenic gel,3D dose imaging,proton beam imaging,tertiary-butyl acrylate gel
更新于2025-09-23 15:23:52
-
Antenna Placement and Performance Tradeoffs with Hand Blockage in Millimeter Wave Systems
摘要： The ongoing commercial deployment of millimeter wave systems brings into focus a number of practical issues in form factor user equipment (UE) design. With wavelengths becoming smaller, antenna gain patterns becoming directional, and link budgets critically dependent on beamforming, it becomes imperative to use a number of antenna modules at different locations of the UE for good performance. While more antennas/modules can enhance beamforming array gains, it comes with the tradeoff of higher component cost, power consumption of the associated radio frequency circuitry, and a beam management overhead in learning the appropriate beam weights. Thus, the goal of a good UE design is to provide robust spherical coverage corresponding to good array gains over the entire sphere around the UE with a low beam management overhead, complexity, and cost. The scope of this paper is to study the implications of two popular commercial millimeter wave UE designs (a face and an edge design) on spherical coverage. We show that analog beam codebooks can result in good performance for both the designs, and the edge design provides a better tradeoff in terms of robust performance (with hand blockage), beam management overhead, implementation complexity from an antenna placement standpoint and cost.
关键词： hand blockage,5G-New Radio,Millimeter wave,spherical coverage,commercial deployments,antenna placement,UE design,modular design
更新于2025-09-23 15:23:52
-
10?Gbps CPRI signals transmission impaired by intercore crosstalk in 5G network fronthauls with multicore fibers
摘要： The impact of intercore crosstalk (ICXT) of weakly-coupled multicore fibers (MCFs) on the transmission performance of a Common Public Radio Interface (CPRI) signal in 5G networks fronthaul is studied by numerical simulation. The results show that forward error correction-supported CPRI signals have more tolerance to ICXT due to the higher targeted bit error rate (of 10?3). For a receiver power penalty of 1 dB, an improvement of the tolerance of CPRI signals to ICXT, due to the increase of the MCF skew by about 1 dB, is observed. However, for the crosstalk levels that lead to 1 dB power penalty, we have shown that, the system is unavailable with a high probability. The crosstalk level required for an acceptable outage probability is about 10 dB lower than the crosstalk level leading to 1 dB power penalty.
关键词： 5G wireless networks,Multicore fiber,Common public radio interface,Outage probability,Intercore crosstalk,Bit error rate
更新于2025-09-23 15:23:52
-
Circular economy in RFID technology: analysis of recycling methods of RFID tags
摘要： Circular Economy (CE) is one of the approaches which are intensively developed and tested in different areas of industry and services. The aim of this solution is to use many kinds of resources in a closed flow and to achieve as a small amount of waste as it is possible. One of the potential areas of using CE is Radio Frequency Identification (RFID). In RFID systems tags are utilized in various forms. This paper addresses investigation of a recycling process of RFID tags. Different attachment methods of these tags were tested and then, a recycling procedure was prepared based on the obtained results in which adhesives are recommended to be used as an attaching material between a tag and an identified object. The mentioned procedure was evaluated with using paper-face RFID tags. It was confirmed applicability of the proposed solution. Moreover, the conducted research revealed that an adhesion force of the adhesive layers in the prepared RFID tags decreased in the most extent during the first recycling cycle. It was found that in order to preserve a high adhesion force of these layers it is suggested to place the tags on a clean surface.
关键词： Zero waste economy,mechanical force measurements,radio frequency identification,multiuse RFID tags,recycling cycle
更新于2025-09-23 15:23:52
-
[IEEE 2018 International Flexible Electronics Technology Conference (IFETC) - Ottawa, ON, Canada (2018.8.7-2018.8.9)] 2018 International Flexible Electronics Technology Conference (IFETC) - Circularly Polarized Microstrip Antenna on Ultrathin PET Substrate for UHF RFID Applications
摘要： Design of a circularly polarized microstrip patch antenna on an ultrathin PET substrate of 125 μm thickness is proposed for RFID applications. Screen-printed silver coating of 25 μm thickness serves as the antenna metallization. Improved feed-design and systematic optimization of the antenna overcomes the intrinsic constrains of designing microstrip antennas on extremely thin substrate. Optimally designed feed excites a nearly square patch antenna with truncated corners to achieve good impedance and radiation characteristics. The proposed antenna exhibiting 48 MHz impedance bandwidth (896 MHz to 944 MHz) and a 16 MHz AR bandwidth (907-923 MHz), can serve as a potential candidate as a low cost UHF reader antenna for RFID applications.
关键词： Microstrip Antenna,radio-frequency identification (RFID),Circular Polarization (CP),Quarter Wave Transformer,Axial Ratio (AR)
更新于2025-09-23 15:23:52
-
Dynamic Behavioral Modeling of RF Power Amplifier Based on Time-Delay Support Vector Regression
摘要： A new, dynamic behavioral modeling technique, based on a time-delay support vector regression (SVR) method, is presented in this paper. As an advanced machine learning algorithm, the SVR method provides an effective option for behavioral modeling of radio frequency (RF) power amplifiers (PAs), taking into account the effects of both device nonlinearity and memory. The basic theory of the proposed modeling technique is given, along with a detailed model extraction procedure. Unlike traditional artificial neural network (ANN) techniques, which take time to determine the best configuration of the model, the SVR method can obtain the optimal model in short time, using the grid-search technique. An example of an optimal SVR model selection applied to an RF PA is also given; the performance of the selected model presents a big improvement when compared with the default SVR model. Experimental validation is performed using an LDMOS PA, a single device gallium nitride (GaN) PA, and a Doherty GaN PA, revealing that the new modeling methodology provides very efficient and extremely accurate prediction. Compared with traditional Volterra models, canonical piecewise linear models, and ANN-based models, the proposed SVR model gives improved performance with reasonable complexity. In addition, it is shown that the model can predict accurately the behavior of the PA under input power levels that are different from those under which it is extracted.
关键词： time delay,radio frequency (RF) power amplifiers (PAs),machine learning,Dynamic behavioral model,support vector regression (SVR)
更新于2025-09-23 15:23:52
-
[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - Assessment of RB Noise in Bidirectional RoF Based on Different O-OFDM SSB Systems
摘要： Novel bidirectional architecture on two optical OFDM SSB modulation techniques to mitigate Rayleigh backscattered and reflections interferences in RoF transmission is proposed. The interference effect is analyzed with mathematical model comparing conventional SSB and the modified SSB based on elimination of higher order RB-RE harmonics.
关键词： Single sideband (SSB) modulation,Orthogonal Frequency Division Multiplexing (OFDM),Bidirectional Radio over Fiber (RoF)
更新于2025-09-23 15:23:52
-
The impact of out of band emissions: A measurement based performance comparison of UF-OFDM and CP-OFDM
摘要： Long Term Evolution (LTE) networks, along with their recent releases, rely on the cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform as the foundation. However, high sidelobes, synchronization problems and spectral efficiency constraints of CP-OFDM cannot meet future requirements of cellular network design targets. At this point, universal filtered orthogonal frequency division multiplexing (UF-OFDM) emerges as a strong candidate. Equipped with the advantages of using filters, UF-OFDM provides additional design flexibility to address the fundamental problems of CP-OFDM. In this study, the effect of adjacent channels that causes interference between different frequency channels because of out-of-band (OoB) emissions on UF-OFDM performance is investigated by performing real-time tests on software defined radio (SDR) nodes with multiple reception paths. Frequency domain carrier frequency offset (CFO) and symbol timing offset (STO) correction techniques are used. By the application of the same correction approaches to CP-OFDM, these two waveforms are evaluated in terms of signal to noise ratio (SNR), bit/symbol error rate (BER/SER) and error vector magnitude (EVM). Test results indicate that, based on lower OoB emissions, UF-OFDM uses the spectrum more efficiently and provides better results than CP-OFDM in congested environments.
关键词： synchronization,CP-OFDM,out-of-band emissions,software defined radio nodes,UF-OFDM
更新于2025-09-23 15:23:52