638 research outputs found
Study on Quality Control of Concrete Raw Materials in Road and Bridge Construction
The main material of concrete is a construction building material composed of water and mineral mixture and cement and chemical additives in the corresponding proportion and below the standard. In the process of making concrete material, slurry and cement are needed to mix, then cement slurry and sand are mixed into mortar according to the corresponding proportion, and aggregate is added to mortar to form concrete building material. In the process of concrete preparation, the most important construction link is mixing, which needs to be fully stirred to make the performance of concrete meet the construction needs. In the process of concrete construction technology development, both mix ratio and production technology have become more and more mature, but there are still some problems, which have an impact on the quality of concrete. Therefore, this paper discusses the quality control of concrete raw materials according to the construction process of road and bridge
Tilted Fiber Bragg Grating Sensors based on Time-Domain Measurements with Microwave Photonics
Tilted fiber Bragg gratings (TFBGs) have garnered substantial research attention and have found widespread applications for sensing a diverse array of physical, chemical, and biological parameters based on optical spectrum measurements. The interrogation of a TFBG sensor typically requires a high-resolution bulky optical spectrum analyzer (OSA) due to the extremely narrow dips caused by the resonance of cladding modes. However, high-resolution OSAs can be costly and have limitations on measuring speed, limiting their practicality. In this paper, a new approach to interrogating TFBG sensors is proposed and experimentally demonstrated based on a microwave photonics technique. Instead of measuring the optical transmission spectrum, the frequency response of the TFBG sensor is acquired using a vector network analyzer. Followed by time domain analysis, sensing information embedded in the transmission spectra of the TFBG sensor subject to external perturbations is successfully extracted. Monitoring of variations in temperature, strain, and liquid level is experimentally demonstrated, and the potential for multi-parameter discrimination is also discussed. The introduced technique is easy to implement, and the corresponding characteristic sensing signal is easy to demodulate, offering a promising solution for TFBG-based sensor systems
Basic Amino Acid Mutations in the Nuclear Localization Signal of Hibiscus Chlorotic Ringspot Virus p23 Inhibit Virus Long Distance Movement
10.1371/journal.pone.0074000PLoS ONE89-POLN
High-Sensitivity Fabry-Perot Interferometric Sensor based on Microwave Photonics with Phase Demodulation
Optical fiber sensors have emerged as vital tools in various applications. Among them, Fabry-Perot interferometers (FPIs), have gained prominence due to their compactness and versatility in sensor design. Microwave photonics (MWP) techniques offer enhanced performance and flexibility for developing optical sensor interrogation methods. This paper proposes and experimentally demonstrates a novel MWP interrogation technique based on phase measurement for short-cavity FPI sensors. The technique utilizes the phase response of the FPI sensor within an MWP-assisted single radio frequency bandpass filter, providing improved sensitivity and dynamic sensing capabilities compared to traditional methods. Simulation and experimental results validate the effectiveness of the proposed technique in measuring both static and dynamic strains. The high sensitivity of the system, surpassing 0.00217 rad/μϵ, enables achieving a high resolution better than 100 nϵ at an operating frequency of 247.0 MHz. Additionally, the feasibility of using the technique for interrogating multiplexed FPIs with different cavity lengths is explored, showing promising results for future sensor development
Transfer Learning for Motor Imagery Based Brain-Computer Interfaces: A Complete Pipeline
Transfer learning (TL) has been widely used in motor imagery (MI) based
brain-computer interfaces (BCIs) to reduce the calibration effort for a new
subject, and demonstrated promising performance. While a closed-loop MI-based
BCI system, after electroencephalogram (EEG) signal acquisition and temporal
filtering, includes spatial filtering, feature engineering, and classification
blocks before sending out the control signal to an external device, previous
approaches only considered TL in one or two such components. This paper
proposes that TL could be considered in all three components (spatial
filtering, feature engineering, and classification) of MI-based BCIs.
Furthermore, it is also very important to specifically add a data alignment
component before spatial filtering to make the data from different subjects
more consistent, and hence to facilitate subsequential TL. Offline calibration
experiments on two MI datasets verified our proposal. Especially, integrating
data alignment and sophisticated TL approaches can significantly improve the
classification performance, and hence greatly reduces the calibration effort
Genome-wide characterization of heavy metal-associated isoprenylated plant protein gene family from Citrus sinensis in response to huanglongbing
IntroductionHeavy metal-associated isoprenylated plant proteins (HIPPs) play vital roles in maintaining heavy metal balance and responding to both biotic and abiotic stresses in vascular plants. However, the role of HIPPs in the response to Huanglongbing (HLB), a harmful disease of citrus caused by the phloem-colonizing bacterium Candidatus Liberibacter asiaticus (CLas), has not been examined.Methods and resultsIn this study, a total of 26 HIPP genes were identified in Citrus sinensis, and they were grouped into 5 clades. The CsHIPP genes are distributed on 8 chromosomes and exhibited considerable synteny with HIPPs found in Arabidopsis thaliana. Additionally, we analyzed the gene structure, conserved motifs and domains of the CsHIPPs. Various cis-acting elements related to plant hormones and stress responses were identified in the promoters of CsHIPPs. Public transcriptome data and RT-qPCR analysis showed that the expression level of CsHIPP03 was significantly reduced in samples infected by CLas and Xanthomonas citri ssp. citri (Xcc). Furthermore, silencing the homologous gene of CsHIPP03 in Nicotiana benthamiana increased the disease resistance of plants to bacteria.DiscussionOur results provide a basis for functional studies of HIPP gene family in C. sinensis, highlighting their functions in bacterial resistance, and improve our understanding to the susceptibility mechanism of HLB
A Fast Time-Step Selection Method for Explicit Solver-Based Simulation of High Frequency Low Loss Circuit and Its Application on EMI Filter
Rational Design of a Chalcogenopyrylium-Based Surface-Enhanced Resonance Raman Scattering-Nanoprobe with Attomolar Sensitivity
High sensitivity and specificity are two desirable features in biomedical imaging. Raman imaging has surfaced as a promising optical modality that offers both. Here, we report the design and synthesis of a group of near infrared absorbing 2-thienyl-substituted chalcogenopyrylium dyes tailored to have high affinity for gold. When adsorbed onto gold nanoparticles, these dyes produce biocompatible SERRS-nanoprobes with attomolar limits of detection amenable to ultrasensitive in vivo multiplexed tumor and disease marker detection
Guiding Brain Tumor Resection Using Surface-Enhanced Raman Scattering Nanoparticles and a Hand-Held Raman Scanner
The current difficulty in visualizing the true extent of malignant brain tumors during surgical resection represents one of the major reasons for the poor prognosis of brain tumor patients. Here, we evaluated the ability of a hand-held Raman scanner, guided by surface-enhanced Raman scattering (SERS) nanoparticles, to identify the microscopic tumor extent in a genetically engineered RCAS/tv-a glioblastoma mouse model. In a simulated intraoperative scenario, we tested both a static Raman imaging device and a mobile, hand-held Raman scanner. We show that SERS image-guided resection is more accurate than resection using white light visualization alone. Both methods complemented each other, and correlation with histology showed that SERS nanoparticles accurately outlined the extent of the tumors. Importantly, the hand-held Raman probe not only allowed near real-time scanning, but also detected additional microscopic foci of cancer in the resection bed that were not seen on static SERS images and would otherwise have been missed. This technology has a strong potential for clinical translation because it uses inert gold-silica SERS nanoparticles and a hand-held Raman scanner that can guide brain tumor resection in the operating room
Integration of Small-Scale Compressed Air Energy Storage with Wind Generation for Flexible Household Power Supply
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