Characterization and Identification of NPK Stress in Rice Using Terrestrial Hyperspectral Images.

Due to nutrient stress, which is an important constraint to the development of the global agricultural sector, it is now vital to timely evaluate plant health. Remote sensing technology, especially hyperspectral imaging technology, has evolved from spectral response modes to pattern recognition and vegetation monitoring. This study established a hyperspectral library of 14 NPK (nitrogen, phosphorus, potassium) nutrient stress conditions in rice. The terrestrial hyperspectral camera (SPECIM-IQ) collected 420 rice stress images and extracted as well as analyzed representative spectral reflectance curves under 14 stress modes. The canopy spectral profile characteristics, vegetation index, and principal component analysis demonstrated the differences in rice under different nutrient stresses. A transformer-based deep learning network SHCFTT (SuperPCA-HybridSN-CBAM-Feature tokenization transformer) was established for identifying nutrient stress patterns from hyperspectral images while being compared with classic support vector machines, 1D-CNN (1D-Convolutional Neural Network), and 3D-CNN. The total accuracy of the SHCFTT model under different modeling strategies and different years ranged from 93.92% to 100%, indicating the positive effect of the proposed method on improving the accuracy of identifying nutrient stress in rice.

28.02 W LD side-pumped CW laser operated at 2.8†µm in YSGG/Er:YSGG/YSGG crystal.

We demonstrated a 978 nm laser diode (LD) side-pumped YSGG/Er:YSGG/YSGG composite crystal with a size of Ф 3 mm × 65 mm and continuous-wave (CW) mode. By optimizing resonator length and output mirror transmittance, a maximum output power of 28.02 W is generated, corresponding to slope efficiency of 17.55% and optical-optical efficiency of 12.29%, respectively. The thermal focal lengths are obtained by resonator stability condition. The laser wavelength is centered near 2.8 µm. Moreover, the beam quality factors M x2/M y2 are fitted to be 8.14 and 7.35, respectively. The above results indicate that a high-performance 2.8 µm CW laser can be achieved by LD side-pumped YSGG/Er:YSGG/YSGG composite crystal with excellent heat dissipation ability, which promotes effectively the development and applications of the mid-infrared solid-state lasers.

Hepatoid Adenocarcinoma of the Esophagus with Thyroid Metastasis: A Case Report.

Rare hepatoid adenocarcinomas are highly heterogeneous. In this case, hepatoid adenocarcinoma occurred in both the esophagus and thyroid, and the combination of chemotherapy and immunotherapy may be a promising therapeutic tool for rare tumors. Laryngoscope, 134:3673-3676, 2024.

A fast response time gas ionization chamber detector with a grid structure.

The time response characteristic of the detector is crucial in radiation imaging systems. Unfortunately, existing parallel plate ionization chamber detectors have a slow response time, which leads to blurry radiation images. To enhance imaging quality, the electrode structure of the detector must be modified to reduce the response time. This paper proposes a gas detector with a grid structure that has a fast response time. In this study, the detector electrostatic field was calculated using COMSOL, while Garfield++ was utilized to simulate the detector's output signal. To validate the accuracy of simulation results, the experimental ionization chamber was tested on the experimental platform. The results revealed that the average electric field intensity in the induced region of the grid detector was increased by at least 33%. The detector response time was reduced to 27% -38% of that of the parallel plate detector, while the sensitivity of the detector was only reduced by 10%. Therefore, incorporating a grid structure within the parallel plate detector can significantly improve the time response characteristics of the gas detector, providing an insight for future detector enhancements.

A rapid response time gas detector with embedded glass plates for digital radiography systems.

The response time of a detector stands as a critical parameter in radiation imaging systems. However, the existing parallel plate ionization chamber detector manifests a noteworthy delay in response time, leading to the production of blurred radiation images. To enhance the image quality of radiation imaging systems, it becomes imperative to modify the electrode structure of the detector and consequently reduce the response time. We propose a gas ionization chamber detector incorporating a glass plate, resulting in a notably swift response time. The COMSOL software is employed to calculate the electric and weighting fields within the detector, while Garfield++ software is utilized to derive the output signal, including information on the response time. To validate the simulation data, an experimental ionization chamber underwent testing on a dedicated platform to acquire the output signal. The results revealed that the average electric field intensity in the induced region of the grid detector was increased by at least 10%. The detector response time was reduced to 50%-28% of that of the parallel plate detector. However, this improvement comes at the cost of a decrease in the detector's sensitivity. The incorporation of glass plates in a parallel plate detector offers a substantial improvement in the time response characteristics of a gas ionization chamber detector, thereby suggesting a valuable direction for future advancements in ionization chamber technology.

ReaxFF Molecular Dynamics Study on the Microscopic Mechanism for Kerogen Pyrolysis.

Kerogen is mainly composed of carbon, hydrogen, and oxygen, which are the main components of crude oil and gas. The pyrolysis of kerogen is an efficient method to generate clean energy. In the present work, the pyrolysis reaction process of three types of kerogen is simulated using ReaxFF molecular dynamics (MD) methods to study the microscopic mechanism and the distribution of products. The results indicated that the pyrolysis products of the three types of kerogen significantly depend on the molecular structures, temperature, and reaction time. As the temperature increases, the gaseous hydrocarbon and the light and heavy oil fractions decreased, where small molecular fragments polymerized to form new molecular fragments. For an isothermal temperature, with the reaction proceeding, some component polymerization of the pyrolyzed fragments occurred, resulting in the generation of new light oils and heavy oils. Moreover, quantum chemical analysis was employed to reveal the kerogen pyrolysis mechanism. First, the weak bonds such as C-O, C-N, and C-S structures were decomposed to generate large carbon and some heavy shale oil fragments. Second, the cycloalkanes and long-chain alkanes were decomposed to generate a large amount of light shale oil and gaseous hydrocarbons. Finally, the decomposition of C═C in the aromatic ring, the secondary decomposition of light and heavy shale oils, and the further decomposition of short-chain alkanes occurred. In addition, the production of hydrogen (H2) occurred at the late stage of the pyrolysis reaction. Hydrogen radicals were formed by the decomposition of C-H bonds and subsequently collided with each other, resulting in the formation of H2 molecules. The pyrolysis and chemical analysis of kerogen can clearly determine the type and content of hydrocarbon substances, providing scientific data for exploration, development, and utilization of shale gas and shale oil.

The timing of the initial collision between the South and North China blocks constraining from the sediments in the eastern Sichuan Basin.

In this study, detrital zircon U-Pb geochronology, trace element and Hf isotopic compositional data from the Early-Middle Triassic clastic rocks in the eastern Sichuan Basin were obtained to distinguish the sediment provenance and constrain the timing of the initial collision between the South China and North China blocks. Detrital zircons from the Early Triassic Feixianguan Formation clastic rocks yield one major age peak at 2476 Ma and three minor age peaks at 1886, 802 and 304 Ma. These detrital zircons may be derived from the South China Block. Detrital zircons from the Early Triassic Jialingjiang Formation clastic rocks yield multiple age peaks at 979, 856, 392 and 269 Ma, indicating a mixed sediment provenance from the South China Block and Qinling Orogenic Belt. This is the first appearance of the detritus with the Qinling Orogenic Belt affinity in the eastern Sichuan Basin. Detrital zircons from the Middle Triassic Leikoupo Formation clastic rocks yield two centralized age peaks at 447 and ca. 245 Ma. These zircons may mainly be derived from the Qinling Orogenic Belt. The results indicate an abrupt change in the detrital zircon U-Pb provenance from the South China Block to the Qinling Orogenic Belt during the Early-Middle Triassic. Integrating the provenance change and other geological characteristics, we suggest that the initial collision in the eastern Qinling Orogenic Belt occurred in the Early Triassic.

Overview of solar thermal applications of heat exchangers with thermophysical features of hybrid nanomaterials.

With their notable thermal characteristics, fluids incorporating nanoparticles have significant importance in industrial processes. Due to the higher proficiency of hybrid nanofluid, this study is organized to observe the flow phenomenon and thermal characteristics of kerosene-oil-based hybrid ferrofluid in relation to the modified versions of two imperative Yamada-Ota and Xue models. A performance-based comparison is conducted for an incompressible hybrid ferrofluid in relation to the upgraded Yamada-Ota and Xue models. The magnetized flow mechanism in two dimensions is explored over a stretchable, curved sheet. With the ordinary kerosene oil liquid, the ferroparticles, namely cobalt ferrite and magnetite, are merged to form (CoFe2O4-Fe3O4/kerosene oil) hybrid ferrofluid. Mass and heat transport mechanisms are scrutinized with the execution of activation energy, convective constraints, Joule heating, exponential heat sources, and thermal radiation. Suitable ansatzes are utilized to achieve the dimensionless pattern of the equations that regulate the problem. To numerically explore the dimensionless equations, a powerful bvp4c strategy is implemented. On behalf of both considered models, the characteristics of hybrid ferrofluid relative to pertinent parameters are graphically investigated and comparatively analyzed. This study ensures that the improved Yamada-Ota model yields more proficient outcomes in comparison to the Xue model. Moreover, the concentration field demonstrates an escalating trend with the enhanced activation energy parameter.

Thermal, spectroscopy and optimized ∼3†µm CW laser properties for Ho,Pr:YAP crystal.

We demonstrate the thermal, spectroscopy and laser properties of Ho,Pr doped YAP crystal grown successfully by Cz method. The thermal expansion coefficient, thermal conductivity, absorption and emission spectra of Ho,Pr:YAP crystal are investigated in detail. Additionally, the level lifetimes suggest that Pr3+ is a suitable deactivating ion for Ho:YAP crystal. Particularly, the actual laser performance is optimized by doping active ion Ho with high concentrations and introducing deactivated Pr3+, resulting in decreased laser threshold, increased laser output power and slope efficiency. A 3.01 µm laser with output power of 502 mW, slope efficiency of 6.3% and beam quality factors of 1.42/1.43 is achieved in the Ho,Pr:YAP crystal, as far as we know this is the highest ∼3 µm CW laser power realized in Ho3+ doped oxide crystals.

Enhancement in the efficiency of heat recovery in a Williamson hybrid nanofluid over a vertically thin needle with entropy generation.

The purpose of the present research is to conduct an examination of entropy generation in a 2D magneto Williamson hybrid nanofluid flow that contains cobalt ferrite and titanium oxide nanoparticles and undergoes surface-catalyzed reactions through a thin vertical needle. The consequences of joule heating and viscous dissipation are considered to elaborate the features of heat transport. Further, the influence of thermal stratification, thermal radiation, and homogeneous-heterogeneous reaction is also taken into account. Through the application of appropriate similarity variables, the dimensionless system of coupled ordinary differential equations is achieved. The coupled system of equations is numerically solved by the usage of the bvp4c technique in the MATLAB algorithm. The current investigation also compared the existing outcomes with the available literature, which shows great harmony between the two. The consequences of the physical parameters are discussed graphically and with numerical data. It is worth noting that larger values of homogeneous reaction strength and the surface-catalyzed parameter diminish the concentration field. Further, the velocity distribution and their related momentum boundary layer thickness, diminishes with the enlargement of the Weissenberg parameter.

Structure, spectroscopy and laser performance of an Er:YGGAG crystal.

In this work, we report on investigations of structure, spectroscopic properties and laser performances of, what we believe to be, a novel Er:YGGAG laser crystal. High crystalline quality is proved by an FWHW of XRC of 0.019°. Thermal conductivity of a 30 at.% Er:YGGAG crystal is determined as 4.98 W/(m·K). The refractive index is measured in the range of 400 to 1000 nm and fitting with Sellmeier equation is done. A broad fluorescence emission band is located at 2786∼2819 nm, suggesting that this crystal is favorable to realize tunable and ultrafast laser. Under the pump at 969 nm with a fiber-coupled diode laser, at 400 Hz repetition rate and 600 µs pulse duration, the 30 at.% Er:YGGAG delivered maximum average power of 506 mW with overall optical-to-optical efficiency of 12.4% and slope efficiency of 16.9%. The laser beam quality was characterized by M2 factors of 1.53 and 1.39 in horizontal and vertical directions, respectively.

Flow investigation of the stagnation point flow of micropolar viscoelastic fluid with modified Fourier and Fick's law.

Non-Newtonian fluids are extensively employed in many different industries, such as the processing of plastics, the creation of electrical devices, lubricating flows, and the production of medical supplies. A theoretical analysis is conducted to examine the stagnation point flow of a 2nd-grade micropolar fluid into a porous material in the direction of a stretched surface under the magnetic field effect, which is stimulated by these applications. The stratification boundary conditions are imposed on the surface of the sheet. Generalized Fourier and Fick's laws with activation energy is also considered to discuss the heat and mass transportation. To obtain the dimensionless version of the flow modeled equations, an appropriate similarity variables are used. These transfer version of equations is solved numerically by the implement of the BVP4C technique on MATLAB. The graphical and numerical results are obtained for various emerging dimensionless parameters and discussed. It is noted that by the more accurate predictions of [Formula: see text] and M, the velocity sketch is decreased due to occurrence of resistance effect. Further, it is seen that larger estimation of micropolar parameter improves the angular velocity of the fluid.

CP2 skyrmions and skyrmion crystals in realistic quantum magnets.

Magnetic skyrmions are nanoscale topological textures that have been recently observed in different families of quantum magnets. These objects are called CP1 skyrmions because they are built from dipoles-the target manifold is the 1D complex projective space, CP1 ≅ S2. Here we report the emergence of magnetic CP2 skyrmions in a realistic spin-1 model, which includes both dipole and quadrupole moments. Unlike CP1 skyrmions, CP2 skyrmions can also arise as metastable textures of quantum paramagnets, opening a new road to discover emergent topological solitons in non-magnetic materials. The quantum phase diagram of the spin-1 model also includes magnetic field-induced CP2 skyrmion crystals that can be detected with regular momentum- (diffraction) and real-space (Lorentz transmission electron microscopy) experimental techniques.

Duloxetine for rehabilitation after total knee arthroplasty: a systematic review and meta-analysis.

OBJECTIVE: The aim was to evaluate the efficacy and safety of duloxetine for postoperative recovery after total knee arthroplasty. METHODS: The following electronic databases were searched for eligible trials: PubMed, EMBASE, Web of Science, Cochrane Library, VIP, Wanfang Data, and China National Knowledge Infrastructure (CNKI). The search was performed from the inception dates to 10 August 2022. Data extraction and quality assessment were performed by two independent reviewers. Standard mean differences or mean differences with 95% CIs for pooled data were calculated. The primary outcomes were pain, physical function, and analgesic consumption. Secondary outcomes included range of motion (ROM) of the knee, depression, and mental health. RESULTS: This meta-analysis included 11 studies, reporting on a total of 1019 patients. Results of analyses indicated that duloxetine showed a statistically significant reduction in pain at rest at 3 days, 1 week, 2, and 6 weeks and pain on movement at 5 days, 1 week, 2, 4, 6, and 8 weeks. However, there was no statistical significance in pain at rest and on movement at 24 h, 12 weeks, 6 months, and 12 months. Additionally, duloxetine had a significant improvement in physical function, ROM of the knee at 6 weeks, and emotional function (depression and mental health). Moreover, the cumulative opioid consumption at 24 h in the duloxetine groups was lower than in the control groups. But there was no statistical significance for the cumulative opioid consumption over 7 days between the duloxetine groups and controls. CONCLUSIONS: In conclusion, duloxetine might reduce pain mainly over a time span of 3 days-8 weeks and lower cumulative opioid consumption within 24 h. In addition, it improved physical function, ROM of the knee with a time span of 1-6 weeks and emotional function (depression and mental health).

α-Arylsulfonyloxyacrylates: attractive O-centered electrophiles for synthesis of α-substituted acrylates via Pd-catalysed Suzuki reactions.

We herein report α-arylsulfonyloxyacrylates as a kind of useful and attractive O-centered electrophiles for Suzuki cross-coupling reactions. A range of α-(hetero)aryl substituted acrylates has been prepared via the palladium-catalysed C-C cross-coupling reactions between potassium (hetero)aryltrifluoroborates and α-arylsulfonyloxyacrylates. Moreover, α-arylsulfonyloxyacrylate could also react with B-alkyl-9-BBN to produce α-alkyl substituted acrylates. The synthetic application of this new method was demonstrated by the preparation of the intermediate for synthesis of retinoid X receptors-selective retinoids. These Suzuki reaction-based protocols feature broad substrate scope, generality, and mild reaction conditions.

Behaviour of polymer-coated composite nanoparticles at bubble-stabilizing interfaces during bubble coarsening and accelerated coalescence: A Cryo-SEM study.

HYPOTHESIS: Dynamics of polymer-coated silica composite nanoparticles (CPs) during bubble coarsening is highly dominated by the behaviour of the polymer layer, while in-situ particle aggregation would lead to accelerated bubble coalescence. EXPERIMENTS: CPs-stabilized foams were prepared in 0.1 M and 0.55 M Na2SO4 solution, referring to the 0.1 M and 0.55 M foam/bubble respectively. The 0.1 M to 0.55 M transition foam was also prepared. High resolution Cryo-SEM was originally used to investigate the CPs behaviour at the bubble-stabilizing interface during bubble coarsening and accelerated coalescence. FINDINGS: The 0.1 M bubble-stabilizing interface buckles in uniaxial compression due to coarsening, with the CPs being observed to desorb from the interface. While the CPs were visualized to rearrange into crumpled particle multi-layers surrounding the shrinking 0.55 M bubbles, due to the adhesion between interpenetrating polymer chains and the unique lubrication effect of the PVP layers. The 0.1 M to 0.55 M transition foaming behaviour was also studied. Cracks and voids were observed at interfaces surrounding the transition bubbles driven by in-situ particle aggregation, resulting in accelerated bubble coalescence during the transition process.

Experimental study of the negative effects of raised bedroom temperature and reduced ventilation on the sleep quality of elderly subjects.

This study investigated the effects of air temperature and ventilation on the sleep quality of elderly subjects and elucidated the mechanisms involved. Sixteen subjects aged over 65 years old were exposed to four conditions in a 2 × 2 design: air temperatures of 27°C and 30°C (with a ceiling fan in operation at 30°C) and two ventilation conditions (with and without mechanical ventilation) in experimental bedrooms. Their electroencephalogram, electrooculogram, chin electromyogram, electrocardiogram, respiration, oxygen saturation, and wrist skin temperature were measured continuously during sleep. Saliva samples were collected, and blood pressure was measured both before and after sleep. The results showed that at the temperature of 30°C, the total sleep time, sleep efficiency, and duration of REM sleep of the elderly decreased by 26.3 min, 5.5%, and 5.3 min, respectively, and time awake increased by 27.0 min, in comparison with 27°C, indicating that the sleep quality of the elderly is very vulnerable to heat exposure. Even a small heat load led to an overactive sympathetic nervous system and increased wrist skin temperature, which reduced sleep quality. Improving the ventilation increased the duration of deep sleep and REM sleep by 10.3 min and 3.7 min, respectively. Higher pollutant concentrations affected the respiration and autonomous nervous systems to reduce sleep quality. The benefits of improved thermal environment and ventilation on sleep quality were found to be additive. Good ventilation and the avoidance of raised temperatures in the bedroom are thus both important for the sleep quality of the elderly.

Microstructure, Fatigue Properties and Stress Concentration Analysis of 6005 Aluminum Alloy MIG Welded Lap Joint.

This paper studies the microstructure and mechanical properties of MIG (Melt Inert Gas) lap welded 6005 aluminum alloy plates. Microstructure analysis (OM) of the joint showed that 15~30 µm small grains were observed at the fusion line. Mechanical analysis shows that the small grains are broken by shielding gas and molten pool flow force. Hardness test shows that there is a softening zone (41~43 HV) in HAZ much lower than BM and WZ. The low cycle fatigue test showed that the performance of lap joint decreased sharply, and the fatigue strength of weld decreased significantly, which was only 27.34% of the base metal. The fatigue fracture (SEM) of the weld observed slip band cracking and a large number of brittle fracture characteristics. Using the stress concentration factor Kt for analysis, it was found that the cause of brittle fracture was mostly stress concentration. Lap joint stress concentration model appears in two ways: firstly, at the weld toe, the weld is subjected to eccentric force, secondly, there is a small gap between the two plates at the weld root, which cracks along the direction of 45° of the maximum shear stress.

Fatigue Property and Small Crack Propagation Mechanism of MIG Welding Joint of 6005A-T6 Aluminum Alloy.

In this study, metal inert gas welding (MIG) was applied to 4 mm thick 6005A-T6 aluminum alloy welding. Compared with other parts, the hardness of the weld zone (WZ) was the lowest, about 67 HV. There was the Softening in WZ, which might make WZ the weakest zone. Then, fatigue tests were carried out on MIG welded joints. All the fatigue specimens fractured at the weld toe of the lap joint, and the fracture was characterized by a cleavage fracture. Crack closure induced by oxide was observed during the steady propagation of the fatigue crack. Impurities hindered crack propagation, changed the direction of crack propagation, and appeared in stepped fatigue strip distribution morphology; in the process of the main crack propagation, the initiation and propagation of small cracks were easily restricted and hindered by the main crack, which slowed down the propagation rate and even stopped the propagation directly.