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1.
Front Plant Sci ; 15: 1346182, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952848

RESUMO

Accurate and real-time field wheat ear counting is of great significance for wheat yield prediction, genetic breeding and optimized planting management. In order to realize wheat ear detection and counting under the large-resolution Unmanned Aerial Vehicle (UAV) video, Space to depth (SPD) module was added to the deep learning model YOLOv7x. The Normalized Gaussian Wasserstein Distance (NWD) Loss function is designed to create a new detection model YOLOv7xSPD. The precision, recall, F1 score and AP of the model on the test set are 95.85%, 94.71%, 95.28%, and 94.99%, respectively. The AP value is 1.67% higher than that of YOLOv7x, and 10.41%, 39.32%, 2.96%, and 0.22% higher than that of Faster RCNN, SSD, YOLOv5s, and YOLOv7. YOLOv7xSPD is combined with the Kalman filter tracking and the Hungarian matching algorithm to establish a wheat ear counting model with the video flow, called YOLOv7xSPD Counter, which can realize real-time counting of wheat ears in the field. In the video with a resolution of 3840×2160, the detection frame rate of YOLOv7xSPD Counter is about 5.5FPS. The counting results are highly correlated with the ground truth number (R2 = 0.99), and can provide model basis for wheat yield prediction, genetic breeding and optimized planting management.

2.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(4): 360-364, 2023 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-37580283

RESUMO

Advanced radiotherapy technology enables the dose to more accurately conform to the tumor target area of the patient, providing accurate treatment for the patient, but the gradient of the patient's radiation dose at the tumor edge is getting larger, which putting forward higher requirements for radiotherapy dose verification. The dose verification system software KylinRay-Dose4D can verify the patient's pre-treatment plan and the in vivo/on-line dose during the patient's treatment, providing important reference for the physicist to modify the radiotherapy plan and ensuring that the patient receives accurate treatment. This study introduces the overall design and key technologies of KylinRay-Dose4D, and tests the pre-treatment plan dose checking calculation and 2D/3D dose verification through clinical cases. The test results showed that the 2D/3D gamma pass rate (3 mm/3%) of KylinRay-Dose4D reconstructed dose compared with TPS plan dose and measured dose is larger than 95%, which indicating that the reconstructed dose of KylinRay-Dose4D meets the requirement of clinical application.


Assuntos
Neoplasias , Radioterapia de Intensidade Modulada , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Software , Imagens de Fantasmas , Radiometria/métodos
3.
Phys Med Biol ; 68(16)2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-37433303

RESUMO

Objective.Computed tomography-cone-beam computed tomography (CT-CBCT) deformable registration has great potential in adaptive radiotherapy. It plays an important role in tumor tracking, secondary planning, accurate irradiation, and the protection of at-risk organs. Neural networks have been improving CT-CBCT deformable registration, and almost all registration algorithms based on neural networks rely on the gray values of both CT and CBCT. The gray value is a key factor in the loss function, parameter training, and final efficacy of the registration. Unfortunately, the scattering artifacts in CBCT affect the gray values of different pixels inconsistently. Therefore, the direct registration of the original CT-CBCT introduces artifact superposition loss.Approach. In this study, a histogram analysis method for the gray values was used. Based on an analysis of the gray value distribution characteristics of different regions in CT and CBCT, the degree of superposition of the artifact in the region of disinterest was found to be much higher than that in the region of interest. Moreover, the former was the main reason for artifact superposition loss. Consequently, a new weakly supervised two-stage transfer-learning network based on artifact suppression was proposed. The first stage was a pre-training network designed to suppress artifacts contained in the region of disinterest. The second stage was a convolutional neural network that registered the suppressed CBCT and CT.Main Results. Through a comparative test of the thoracic CT-CBCT deformable registration, whose data were collected from the Elekta XVI system, the rationality and accuracy after artifact suppression were confirmed to be significantly improved compared with the other algorithms without artifact suppression.Significance. This study proposed and verified a new deformable registration method with multi-stage neural networks, which can effectively suppress artifacts and further improve registration by incorporating a pre-training technique and an attention mechanism.


Assuntos
Artefatos , Tomografia Computadorizada de Feixe Cônico Espiral , Algoritmos , Tomografia Computadorizada de Feixe Cônico/métodos , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Humanos
4.
Front Pediatr ; 8: 551, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072658

RESUMO

To compare a novel modified W-incision scrotoplasty (MWS) operation method with the conventional V-Y scrotoplasty for treatment of severe penoscrotal webbing (PSW) in children a retrospective study was conducted on 26 children. Circumcision combined with modified scrotoplasty was used to repair the webbed penis and phimosis of children and another 32 patients undergoing V-Y scrotoplasty served as the control group. There was a statistically significant difference of angle improvements of penis and scrotum in a horizontal position (-66 ± 10; -57 ± 6, P < 0.001) and the parent satisfaction score (Five Likert Scale) (4.7 ± 0.56; 3.8 ± 0.47, P < 0.001) between the two groups. All 26 children who underwent MWS presented with no serious postoperative complications, and there was no significant difference in surgical complications compared to children treated with V-Y scrotoplasty.

5.
Phys Med Biol ; 65(18): 185015, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32521518

RESUMO

The pencil beam algorithm (PBA) has become the predominant dose calculation method in proton therapy, due to its high level of efficiency. However, density heterogeneity decreases the accuracy of PBA. To improve PBA's accuracy, a beam splitting method is used to divide the original scanning beam into multiple thinner beamlets. Beam splitting should ensure that the beamlets' summed fluence is as close to the original beam fluence as possible, while keeping the spatial variance of beamlets small, and minimizing the number of beamlets. In this work, the generalized differential evolution (GDE) algorithm is utilized for the optimal scheme. Under reasonable constraints for the radius and weight of beamlets, several schemes are optimized via the GDE algorithm. In order to achieve a trade-off between accuracy and calculation speed, three hexagon-based schemes, which split the original beam into 7, 13, and 19 beamlets, respectively, are proposed and compared with the scheme of Raystation 4.5. The fluence distribution calculated by the schemes with 13 beamlets and 19 beamlets are demonstrated to be more accurate than the Raystation scheme, which has 19 beamlets, with a maximum absolute difference between the summed beamlets fluence and the original beam fluence of 2.12%, and 0.93%, respectively. Furthermore, beam splitting schemes are implemented into a proton dose calculation algorithm based on the KylinRay-IMPT TPS. These schemes, based on the dose algorithm, are compared with the Monte Carlo program TOPAS 3.2 in slab geometry with lateral heterogeneity. The dose, calculated by the dose algorithm using a scheme of 13 beamlets, shows a good agreement with the dose from TOPAS. In addition, an abdominal geometry is used for further verification. Gamma analysis passing rates greater than 99.7% are observed, with a 2%/2 mm criterion. Thus, the accuracy and effectiveness of the improved beam splitting method are preliminarily verified.


Assuntos
Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Algoritmos , Humanos , Método de Monte Carlo , Dosagem Radioterapêutica
6.
ACS Appl Mater Interfaces ; 11(25): 22692-22702, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199111

RESUMO

Poly(tetrafluoroethylene) (Teflon) has been selected as the self-template structural material in the preparation of VO2 films using a reactive magnetron sputtering method and post-annealing process. VO2 films with spontaneous random nanoporous structures growing on quartz glasses have been deliberately established via bottom-up processing through this novel and facile approach. The nanoporous VO2 films exhibit an excellent optical performance based on the localized surface plasmon resonance, with ultrahigh luminous transmittance ( Tlum-L) up to 78.0% and the promoted solar modulation ability (Δ Tsol) of 14.1%. Meanwhile, the ingenious microstructure of the film provides an antireflection function from multiple perspectives on visible light and indicates the potential of the windshield on vehicles for smart solar modulation. The nanoporous films expand the practical application of thermochromic VO2 to a fire-new field, breaking the optical performance envelope of the single-layer dense VO2 film away, and offering a universal method to prepare homogeneous nanoporous structures for thin films.

7.
ACS Appl Mater Interfaces ; 11(5): 4712-4718, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30672290

RESUMO

The VO2 film with "movable" antireflective (AR) coating was initially designed and successfully prepared to deal with the challenges that VO2 faced. The "movable" AR layer, including water and other organic solvents, not only endowed VO2 with active-passive regulation mode but also dramatically enhanced the thermochromic performance. Furthermore, we combined solid and movable antireflection layer for further structural optimization, and the result turned out to be superior to any multilayer structure reported previously. We believe that this revolutionary concept of AR coating will open up a new avenue for low-cost smart window applications.

8.
Chem Commun (Camb) ; 54(41): 5241-5244, 2018 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-29726884

RESUMO

Here, we fabricated an oxygen-deficient WO3-x crystalline/amorphous homojunction with a strong and tunable localized surface plasmon resonance (LSPR) absorption and realized selective solar modulation over infrared light by controlling the experimental parameters. The homojunction shows good LSPR stability in photochromic cycles, which paves the way to control LSPR applications.

9.
Sci Rep ; 8(1): 5342, 2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29593280

RESUMO

Coating of VO2-based thin film has been extensively studied for fabricating energy-saving smart windows. One of the most efficient ways for fabricating high performance films is to create multi-nanolayered structure. However, it has been highly challenge to make such layers in the VO2-based films using conventional methods. In this work, a facile two-step approach is established to fabricate multilayered VO2-TiO2 thin films. We first deposited the amorphous thin films upon sputtering, and then anneal them to transform the amorphous phase into alternating Ti- and V-rich multilayered nanostructure via a spinodal decomposition mechanism. In particular, we take advantage of different sapphire substrate planes (A-plane (11-20), R-plane (1-102), C-plane (0001), and M-plane (10-10)) to achieve different decomposition modes. The new approach has made it possible to tailoring the microstructure of the thin films for optimized performances by controlling the disorder-order transition in terms of both kinetic and thermodynamic aspects. The derived thin films exhibit superior optical modulation upon phase transition, significantly reduced transition temperature and hysteresis loop width, and high degradation resistance, these improvements indicate a high potential to be used for fabricating the next generation of energy saving smart windows.

10.
ACS Appl Mater Interfaces ; 9(31): 26029-26037, 2017 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-28723095

RESUMO

In the pursuit of energy efficient materials, vanadium dioxide (VO2) based smart coatings have gained much attention in recent years. For smart window applications, VO2 thin films should be fabricated at low temperature to reduce the cost in commercial fabrication and solve compatibility problems. Meanwhile, thermochromic performance with high luminous transmittance and solar modulation ability, as well as effective UV shielding function has become the most important developing strategy for ideal smart windows. In this work, facile Cr2O3/VO2 bilayer coatings on quartz glasses were designed and fabricated by magnetron sputtering at low temperatures ranging from 250 to 350 °C as compared with typical high growth temperatures (>450 °C). The bottom Cr2O3 layer not only provides a structural template for the growth of VO2 (R), but also serves as an antireflection layer for improving the luminous transmittance. It was found that the deposition of Cr2O3 layer resulted in a dramatic enhancement of the solar modulation ability (56.4%) and improvement of luminous transmittance (26.4%) when compared to single-layer VO2 coating. According to optical measurements, the Cr2O3/VO2 bilayer structure exhibits excellent optical performances with an enhanced solar modulation ability (ΔTsol = 12.2%) and a high luminous transmittance (Tlum,lt = 46.0%), which makes a good balance between ΔTsol and Tlum for smart windows applications. As for UV-shielding properties, more than 95.8% UV radiation (250-400 nm) can be blocked out by the Cr2O3/VO2 structure. In addition, the visualized energy-efficient effect was modeled by heating a beaker of water using infrared imaging method with/without a Cr2O3/VO2 coating glass.

11.
Nanoscale ; 9(24): 8298-8304, 2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28585945

RESUMO

Plasmonic materials have drawn emerging interest with their high charge carrier density and solar harvesting ability, resulting in tunable enhanced absorption and scattering resonances. Herein, a novel plasmonic MoO3-x hybrid comprising orthorhombic MoO3-x nanorod and hexagonal MoO3 nanograin was obtained using a simple hydrothermal method. An excellent photochromic property with up to 40% solar modulation efficiency at 600-1000 nm was achieved, which was mainly attributed to the localized surface plasmon resonance (LSPR) absorption at around 900 nm and the polaron absorption at 650 nm with a synergistic effect. In comparison to the limited near-infrared absorption of conventional crystalline MoO3, a distinct modulation range in the critical range between visible and near-infrared was rationalized by a size effect deduced from Mie scattering theory. Our research provided a novel plasmonic molybdenum oxide hybrid to realize an optical modulation function with a tunable wavelength range for energy saving.

12.
Chem Asian J ; 12(14): 1709-1714, 2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28636086

RESUMO

In this Communication, we report MoO3-x nanocomposites in which the near-infrared and visible light transmittance can be selectively modulated through the crystallinity. The MoO3-x nanocomposites were fabricated by a hydrothermal method, and their optical properties were characterized by UV-Vis spectrometer. The obtained results proved the possibility to tune the nanocomposite's optical properties in the UV/Visible spectral region: crystalline MoO3 mainly regulates the near-infrared range (800-2600 nm), and amorphous MoO3-x mainly changes the visible range from 350 nm to 800 nm and MoO3-x , with semi-crystalline structures mainly modulating around 800-1000 nm. These kinds of optical modulations could be attributed to small polar absorption, free electron absorption and plasmon absorption according to different crystallinity. Our work may create new possibilities for future applications such as photochromism, photocatalysis, and electrochromism.

13.
ACS Appl Mater Interfaces ; 8(11): 7054-9, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-26937588

RESUMO

Composite films of VO2-TiO2 were deposited on sapphire (11-20) substrate by cosputtering method. Self-assembled well-ordered multilayer structure with alternating Ti- and V-rich epitaxial thin layer was obtained by thermal annealing via a spinodal decomposition mechanism. The structured thermochromic films demonstrate superior optical modulation upon phase transition, with significantly reduced transition temperature. The results provide a facile and novel approach to fabricate smart structures with excellent performance.

14.
Spectrochim Acta A Mol Biomol Spectrosc ; 134: 388-98, 2015 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-25025311

RESUMO

Ho(3+)/Yb(3+) codoped TeO2-WO3-ZnO-ZnX2(X=F, Cl) glasses were prepared by melt-quenching method. The absorption spectra, transmittance spectra, X-ray diffraction (XRD) curves, Raman spectra and mid-infrared fluorescence spectra were measured, along with the Judd-Ofelt intensity parameters, stimulated emission and absorption cross-sections were calculated to evaluate the effects of halide amount of the spectroscopic properties. It is shown that the introduction of an appropriate amount of halide can further improve the mid-infrared fluorescence intensity through an enhanced phonon-assisted energy transfer between Ho(3+)/Yb(3+) ions and the energy transfer mechanisms are investigated quantitatively in detail by calculating energy transfer microparameters and phonon contribution ratios. The results indicate that this kind of glasses is a promising material for mid-infrared optical fiber.


Assuntos
Vidro/química , Hólmio/química , Telúrio/química , Itérbio/química , Transferência de Energia , Fluorescência , Halogenação , Difração de Raios X
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