192 research outputs found
Composite metamaterials with dual-band magnetic resonances in the terahertz frequency regime
Composite metamaterials(CMMs) combining a subwavelength metallic hole array
(i.e. one-layer fishnet structure) and an array of split-ring resonators(SRRs)
on the same board are fabricated with gold films on silicon wafer. Transmission
measurements of the CMMs in the terahertz range have been performed. Dual-band
magnetic resonances, namely, a LC resonance at 4.40 THz and an additional
magnetic resonance at 8.64 THz originating from the antiparallel current in
wire pairs in the CMMs are observed when the electrical field polarization of
the incident light is parallel to the gap of the component SRR. The numerical
simulations agree well with the experimental results and further clarify the
nature of the dual-band magnetic resonances.Comment: 4 figures, 14 page
Optimization of Worker Scheduling at Logistics Depots Using Genetic Algorithms and Simulated Annealing
This paper addresses the optimization of scheduling for workers at a
logistics depot using a combination of genetic algorithm and simulated
annealing algorithm. The efficient scheduling of permanent and temporary
workers is crucial for optimizing the efficiency of the logistics depot while
minimizing labor usage. The study begins by establishing a 0-1 integer linear
programming model, with decision variables determining the scheduling of
permanent and temporary workers for each time slot on a given day. The
objective function aims to minimize person-days, while constraints ensure
fulfillment of hourly labor requirements, limit workers to one time slot per
day, cap consecutive working days for permanent workers, and maintain
non-negativity and integer constraints. The model is then solved using genetic
algorithms and simulated annealing. Results indicate that, for this problem,
genetic algorithms outperform simulated annealing in terms of solution quality.
The optimal solution reveals a minimum of 29857 person-days
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Regulation of Two-Dimensional Lattice Deformation Recovery
The lattice directly determines the electronic structure, and it enables controllably tailoring the properties by deforming the lattices of two-dimensional (2D)materials. Owing to the unbalanced electrostatic equilibrium among the dislocated atoms, the deformed lattice is thermodynamically unstable and would recover to the initial state. Here, we demonstrate that the recovery of deformed 2D lattices could be directly regulated via doping metal donors to reconstruct electrostatic equilibrium. Compared with the methods that employed external force fields with intrinsic instability and nonuniformity, the stretched 2D molybdenum diselenide (MoSe2)could be uniformly retained and permanently preserved via doping metal atoms with more outermost electrons and smaller electronegativity than Mo. We believe that the proposed strategy could open up a new avenue in directly regulating the atomic-thickness lattice and promote its practical applications based on 2D crystals. © 2019 The Author(s
Therapeutic potential of traditional Chinese medicine in pancreatic fibrosis: mechanisms of TCM formulas and active ingredients
Pancreatic fibrosis (PF), the primary pathological hallmark of chronic pancreatitis (CP), is recognized as a pivotal driver of CP progression. Currently, no therapies are approved by the U.S. Food and Drug Administration (FDA) specifically for PF treatment, highlighting an urgent need for novel therapeutic strategies. Emerging evidence positions Traditional Chinese Medicine (TCM) as a promising multi-target approach against PF. This paper summarizes the pathogenesis of PF and provides a detailed review and comprehensive analysis of the mechanisms underlying Chinese herbal formulas and active ingredients investigated for PF prevention and treatment in existing experimental studies. Numerous studies indicate that TCM combats PF by inhibiting pancreatic stellate cells (PSCs) activation, regulating extracellular matrix (ECM) breakdown, suppressing macrophage infiltration and polarization, and inhibiting pancreatic acinar cell apoptosis. Current basic research predominantly focuses on PSC activation and associated signaling pathways, particularly key pathways such as TGF-β/Smad, MAPK, NF-κB, and Hedgehog. This work thus offers novel insights and approaches for PF treatment and further research
Micro-reflectance and transmittance spectroscopy: a versatile and powerful tool to characterize 2D materials
Optical spectroscopy techniques such as differential reflectance and
transmittance have proven to be very powerful techniques to study 2D materials.
However, a thorough description of the experimental setups needed to carry out
these measurements is lacking in the literature. We describe a versatile
optical microscope setup to carry out differential reflectance and
transmittance spectroscopy in 2D materials with a lateral resolution of ~1
micron in the visible and near-infrared part of the spectrum. We demonstrate
the potential of the presented setup to determine the number of layers of 2D
materials and to characterize their fundamental optical properties such as
excitonic resonances. We illustrate its performance by studying mechanically
exfoliated and chemical vapor-deposited transition metal dichalcogenide
samples.Comment: 5 main text figures + 1 table with all the part numbers to replicate
the experimental setup + 4 supp. info. figure
Assessment of community-wide antimicrobials usage in Eastern China using wastewater-based epidemiology
RT-DETR-SoilCuc: detection method for cucumber germinationinsoil based environment
Existing seed germination detection technologies based on deep learning are typically optimized for hydroponic breeding environments, leading to a decrease in recognition accuracy in complex soil cultivation environments. On the other hand, traditional manual germination detection methods are associated with high labor costs, long processing times, and high error rates, with these issues becoming more pronounced in complex soil–based environments. To address these issues in the germination process of new cucumber varieties, this paper utilized a Seed Germination Phenotyping System to construct a cucumber germination soil–based experimental environment that is more closely aligned with actual production. This system captures images of cucumber germination under salt stress in a soil-based environment, constructs a cucumber germination dataset, and designs a lightweight real-time cucumber germination detection model based on Real-Time DEtection TRansformer (RT-DETR). By introducing online image enhancement, incorporating the Adown downsampling operator, replacing the backbone convolutional block with Generalized Efficient Lightweight Network, introducing the Online Convolutional Re-parameterization mechanism, and adding the Normalized Gaussian Wasserstein Distance loss function, the training effectiveness of the model is enhanced. This enhances the model’s capability to capture profound semantic details, achieves significant lightweighting, and enhances the model’s capability to capture embryonic root targets, ultimately completing the construction of the RT-DETR-SoilCuc model. The results show that, compared to the RT-DETR-R18 model, the RT-DETR-SoilCuc model exhibits a 61.2% reduction in Params, 61% reduction in FLOP, and 56.5% reduction in weight size. Its [email protected], precision, and recall rates are 98.2%, 97.4%, and 96.9%, respectively, demonstrating certain advantages over the You Only Look Once series models of similar size. Germination tests of cucumbers under different concentrations of salt stress in a soil-based environment were conducted, validating the high accuracy of the RT-DETR-SoilCuc model for embryonic root target detection in the presence of soil background interference. This research reduces the manual workload in the monitoring of cucumber germination and provides a method for the selection and breeding of new cucumber varieties
YOLOv8-segANDcal: segmentation, extraction, and calculation of soybean radicle features
The high-throughput and full-time acquisition of images of crop growth processes, and the analysis of the morphological parameters of their features, is the foundation for achieving fast breeding technology, thereby accelerating the exploration of germplasm resources and variety selection by crop breeders. The evolution of embryonic soybean radicle characteristics during germination is an important indicator of soybean seed vitality, which directly affects the subsequent growth process and yield of soybeans. In order to address the time-consuming and labor-intensive manual measurement of embryonic radicle characteristics, as well as the issue of large errors, this paper utilizes continuous time-series crop growth vitality monitoring system to collect full-time sequence images of soybean germination. By introducing the attention mechanism SegNext_Attention, improving the Segment module, and adding the CAL module, a YOLOv8-segANDcal model for the segmentation and extraction of soybean embryonic radicle features and radicle length calculation was constructed. Compared to the YOLOv8-seg model, the model respectively improved the detection and segmentation of embryonic radicles by 2% and 1% in mAP50-95, and calculated the contour features and radicle length of the embryonic radicles, obtaining the morphological evolution of the embryonic radicle contour features over germination time. This model provides a rapid and accurate method for crop breeders and agronomists to select crop varieties
Akabane virus isolated from biting midges and its infection in local domestic animal, Yunnan, China: a field and laboratory investigation
IntroductionWe verified that Akabane virus (AKAV) is transmitted through biting midges and infects local domestic animals.MethodsIn 2013, viruses were isolate from biting midges in Yunnan, China, using BHK-21 and C6/36 cells. Two AKAV strains (No. 52 and 55) that induced cytopathogenic effects (CPE) in BHK-21, MDBK, and Vero cells were characterized.ResultsThe complete genomic sequence of both viruses consisted three RNA segments (S, M, and L). The S segment (856 nucleotides) encoded a 233-amino-acid nucleocapsid protein and a 91-amino-acid nonstructural protein, while the M segment (4309 nucleotides) encoded a 1401-amino-acid polyprotein. The L segment (6869 nucleotides) encoded a 2511-amino-acid RNA-dependent RNA polymerase. Phylogenetic analysis revealed that specimen Nos. 52 and 55 clustered with AKAV genotype Ia viruses isolated from Asia. The AKAV strain (55) neutralizing antibody exhibited a total positive rate of 43.55% (202/466) against serum samples from cattle and goats collected in Yunnan Province. Specifically, the positive rates were 48.77% (139/285) for cattle and 34.81% (63/181) for goats. Neutralizing antibody titers in cattle (1:32–1:128) were higher than those in goats (1:4–1:16).DiscussionThis study represents the first isolation of AKAV from biting midges in China, along with the detection of high neutralizing antibody titers against AKAV in the serum samples of local cattle and goats. These findings suggested that biting midges are involved in AKAV transmission among domestic animals in Yunnan Province, China
A biophoton method for identifying the quality states of fresh Chinese herbs
Introduction: The quality of Chinese herbs is the basis for ensuring their safety and efficacy. However, the quality evaluation system is imperfect. In particular, there is a lack of quality evaluation methods for fresh Chinese herbs during growth. The biophoton is a common phenomenon and provides complete information about the interior of the living system, which is consistent with the holistic concept of traditional Chinese medicine. Therefore, we aim to correlate the biophoton characteristics with the quality states to find the biophoton parameters that can characterize the quality states of fresh Chinese herbs.Methods: The biophoton characteristics of motherwort and safflower were measured and characterized by the counts per second (CPS) in the steady state and the initial intensity (I0) and coherent time (T) of delayed luminescence. The active ingredient content was measured by ultra-high-performance liquid chromatography (UPLC). The pigment content of motherwort leaves was measured by UV spectrophotometry. The t-test and correlation analysis were performed on the experimental results.Results: The CPS and I0 of motherwort and I0 of safflower showed a significant downward trend during the growth process, and their active ingredient content showed a trend that increased and then decreased. The CPS, I0, and the content of active ingredients and pigments in a healthy state were significantly higher than those in a poor state, while T showed the opposite results. The CPS and I0 were all significantly and positively correlated with the content of active ingredients and pigments, while the T of motherwort showed the opposite results.Conclusion: It is feasible to identify the quality states of fresh Chinese herbs by using their biophoton characteristics. Both CPS and I0 have better correlations with the quality states and can be considered characteristic parameters of the quality of fresh Chinese herbs
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