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tuning the particle size,physical properties,and photocatalytic activity of Ag_(3)PO_(4)materials by changing the Ag^(+)/PO_(4)^(3-)ratio

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Chinese Physics B 2023年第3期32卷 561-568页

作者： Hung N M Oanh L t M Chung D P thang D v mai v t Hang L t Minh N v Center for Nano Science and technology Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi 100000Vietnam Department of Physics Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi 100000Vietnam Hanoi University of Mining and Geology Duc Thang WardNorth Tu Liem DistrictHanoi 100000Vietnam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoi 100000Vietnam Faculty of Basic Sciences Hanoi University of Natural Resources and Environment41 A Phu Dien RoadNorth Tu LiemHanoi 100000Vietnam

this study demonstrates the influence of the Ag^(+)/PO_(4)^(3-)ratio in precursor solution on the crystal structural formation,morphology,physical properties,and photocatalytic performance of a Ag_(3)PO_(4)photocatalyst that is fabricated,using a facile precipitation method,from AgNO_(3)and Na2HPO_(4)·12H_(2)*** material characterizations were carried out using x-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive x-ray spectroscopy(EDX),Brunauer–Emmett–teller(BEt)surface area,Fourier transform infrared(FtIR)absorption,Raman scattering,x-ray photoelectron spectroscopy(XPS),Uv-vis absorption,and photoluminescence(PL).the results show that Ag_(3)PO_(4)crystallizes better when the excess PO_(4)^(3-)content increases,and the lattice parameters decrease slightly,while the crystal diameter and the particle size *** change is also observed in the Raman scattering and FtIR spectra with the increase in the vibration frequency of the[PO_(4)]*** compression of the[PO_(4)]unit was also confirmed in the XPS spectra with the shift of P 2p peaks toward higher binding *** photocatalytic results showed that the samples synthesized from excess PO_(4)^(3-)solution exhibited higher photocatalytic performance compared to the sample with a Ag^(+)/PO_(4)^(3-)ratio of 3:1.A sample prepared from the precursor solution with a Ag^(+)/PO_(4)^(3-)ratio of 3:1.5 was optimal for RhB decomposition under both visible light and natural sunlight,completely decomposing 10 ppm RhB after 15 minutes of xenon lamp irradiation and after 60 minutes under solar light *** is attributed to the high crystallinity,small particle size and low electron–hole recombination rate of the sample.

关键词： morphology photocatalytic Ag^(+)/PO_(4)^(3-)ratio visible light

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Efficient and Stable Perovskite Solar Cells and Modules Enabled by tailoring Additive Distribution According to the Film Growth Dynamics

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Nano-Micro Letters 2025年第2期17卷 387-400页

作者： Mengen Ma Cuiling Zhang Yujiao Ma Weile Li Yao Wang Shaohang Wu Chong Liu Yaohua mai Institute of New Energy technology College of Physics&Optoelectronic EngineeringJinan UniversityGuangzhou 510632People’s Republic of China Key Laboratory of New Semiconductors and Devices of Guangdong Higher Education Institutes Jinan UniversityGuangzhou 510632People’s Republic of China Guangdong Mellow Energy Co. LimitedYuanming RoadZhuhai 519075GuangdongPeople’s Republic of China

Gas quenching and vacuum quenching process are widely applied to accelerate solvent volatilization to induce nucleation of perovskites in blade-coating *** this work,we found these two pre-crystallization processes lead to different order of crystallization dynamics within the perovskite thin film,resulting in the differences of additive *** then tailor-designed an additive molecule named 1,3-bis(4-methoxyphenyl)thiourea to obtain films with fewer defects and holes at the buried interface,and prepared perovskite solar cells with a certified efficiency of 23.75%.Furthermore,this work also demonstrates an efficiency of 20.18%for the large-area perovskite solar module(PSM)with an aperture area of 60.84 cm^(2).the PSM possesses remarkable continuous operation stability for maximum power point tracking of t_(90)>1000 h in ambient air.

关键词： Gas quenching Additive distribution Buried passivation Blade coating Crystallization dynamics

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Semantic Segmentation of Lumbar vertebrae Using Meijering U-Net(MU-Net)on Spine Magnetic Resonance Images

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 733-757页

作者： Lakshmi S v v Shiloah Elizabeth Darmanayagam Sunil Retmin Raj Cyril Department of Computer Science and Engineering College of Engineering GuindyAnna UniversityChennai600025India Department of Information technology Madras Institute of TechnologyAnna UniversityChrompetChennai600044India

Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people *** to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the *** semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar *** is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation *** work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra ***-colour mask images were generated and used as ground truth for training the *** work has been carried out on 1312 images expanded from t1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley *** proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.

关键词： Computer aided diagnosis(CAD) magnetic resonance imaging(MRI) semantic segmentation lumbar vertebrae deep learning U-Net model

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Recent advances and remaining gaps in our knowledge of associations between gut microbiota and human health

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World Journal of Gastroenterology 2009年第1期15卷 81-85页

作者： volker mai Peter v Draganov Department of Gastroenterology Hepatology and Nutrition University of Florida1600 SW Archer Rd Room HD 602 PO Box 100214 Gainesville Florida 32610 United States

the complex gut microbial flora harbored by individuals(microbiota) has long been proposed to contribute tointestinal health as well as disease. Pre-and probioticproducts aimed at improving health by modifyingmicrobiota composition have already become widelyavailable and acceptance of these products appearsto be on the rise. However, although required forthe development of effective microbiota basedinterventions, our basic understanding of microbiotavariation on a population level and its dynamics withinindividuals is still rudimentary. Powerful new parallelsequence technologies combined with other efficientmolecular microbiota analysis methods now allow forcomprehensive analysis of microbiota composition inlarge human populations. Recent fi ndings in the fi eldstrongly suggest that microbiota contributes to thedevelopment of obesity, atopic diseases, inflammatorybowel diseases and intestinal cancers. through theongoing National Institutes of Health Roadmap 'HumanMicrobiome Project' and similar projects in other partsof the world, a large coordinated effort is currentlyunderway to study how microbiota can impact humanhealth. translating findings from these studies intoeffective interventions that can improve health,possibly personalized based on an individuals existingmicrobiota, will be the task for the next decade(s).

关键词： Microbiota Intestinal microbial flora Probiotic Gut Intestine

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A kinetic model for a single step biodiesel production from a high free fatty acid (FFA) biodiesel feedstock over a solid heteropolyacid catalyst

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Green Energy & Environment 2019年第3期4卷 328-341页

作者： Aashish Gaurav Stéphane Dumas Chau t.Q.mai Flora t.t.Ng Department of Chemical Engineering University of Waterloo

Production of biodiesel from yellow grease(waste cooking oil and waste animal fats) is fast emerging as a promising alternative to address the twin challenges before the biodiesel industry today-fluctuation in prices of vegetable oil and the food versus fuel debate. Yellow grease has a high percentage of free fatty acids(FFA) and proves to be an unsuitable feedstock for biodiesel production from commercially viable alkalicatalyzed production systems due to saponification problems.'Green' methodologies based on heterogeneous solid acid catalyzed reactions have the potential to simultaneously promote esterification and transesterification reactions of yellow grease to produce biodiesel without soap formation and offer easy catalyst separation without generation of toxic streams. this paper presents kinetic studies for the conversion of model yellow grease feeds to biodiesel using a heteropolyacid supported on alumina(HSiW/Al2O3) using a batch autoclave. three model yellow grease feeds were prepared using canola oil with added FFA such as palmitic, oleic and linoleic acid. A pseudo homogeneous kinetic model for the parallel esterification and transesterification was developed. the rate constants and activation parameters for esterification and transesterification reactions for the model yellow grease feeds were determined. the rate constants for esterification are higher than the transesterification rate constants. the kinetic model was validated using the experimental biodiesel data obtained from processing a commercial yellow grease feed. the kinetic model could be used to design novel processes to convert various low-value waste oils, fats and non-food grade oils to sustainable biodiesel.

关键词： Yellow grease Canola oil Free fatty acids Heteropolyacid Kinetics for esterification and transesterification

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3D Kinematics of Classical Cepheids According to Gaia EDR3 Catalog

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Research in Astronomy and Astrophysics 2023年第4期23卷 1-14页

作者： v.v.Bobylev A.t.Bajkova Pulkovo Astronomical Observatory St.-Petersburg 196140Russia

the kinematics of about 2000 classical Cepheids of the Milky Way with data from Gaia EDR3 catalog has been *** some of these stars,there are line-of-sight *** the basis of the nonlinear rotation model,the parameters of the rotation curve of the Galaxy were *** circular linear rotation velocity of the near-solar neighborhood around the Galaxy center was v0=236±3 km s^(−1) for the assumed Sun's galactocentric distance R0=8.1±0.1 *** of residual velocities of Cepheids based on the linear Ogorodnikov–Milne model showed the presence of the following significantly different from zero gradients:∂U/∂x,∂U/∂z,∂v/∂x,∂v/∂z and∂W/∂x,which behave differently depending on the selection *** most interesting is the gradient∂W/∂x∼−0.5±0.1 km s^(−1) kpc^(−1)(positive rotation of this star system around the Galactic axis y,Ωy)since the velocities W are free of Galactic *** we have an indirect influence of various effects leading to a perturbation of the vertical velocities of the Galactic disk *** on a simpler model,a more accurate estimate of this rotation is obtained,Ωy=0.51±0.07 km s^(−1) kpc^(−1).

关键词： stars distances-Galaxy kinematics and dynamics-stars variables Cepheids

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How Common can the Origin of Clusters Cha Ⅰ, Cha Ⅱ, ∈Cha and η Cha be?

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Research in Astronomy and Astrophysics 2024年第5期24卷 28-34页

作者： v.v.Bobylev A.t.Bajkova Pulkovo Astronomical Observatory St.-Petersburg 196140Russia

the trajectories of the groupings η Cha,∈Cha and Cha I,Cha II,constructed backward in time,have been *** concluded that the hypothesis about the joint formation of all four of these clusters from one molecular cloud cannot be completely ***,10–15 Myr ago,all these four clusters were located at approximately the same height above the plane of the ***,the gas-dust clouds from which all these four clusters were formed were located on one broad *** is possible that the appearance of the Cha I,Cha II,∈Cha and η Cha clusters may be associated with the impact on such a front of shock waves formed after supernova explosions in the Scorpius–Centaurus *** estimates of the kinematic ages of the clusters Cha I and Cha II are obtained as 0.12±0.19 and 0.05±0.15,*** is shown that the minimum size of the Cha I-north and Cha I-south clusters corresponded to the time of 0.55±0.24 Myr and 0.04±0.18 Myr ago,respectively,and approximately1.5 Myr ago the distance between the trajectories of these two groupings was minimal.

关键词： stars distances-stars kinematics and dynamics-galaxies star formation

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the Planck theory of Sonoluminescence

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Progress in Natural Science:Materials International 1998年第4期8卷 3-5页

作者： t.v.Prevenslik 2E Greenery Court China Discovery Bay Hong Kong

Sonolummescence (SL) may be explained by a theory, called the Planck theory of SL that treats she bubbles as miniature collapsing cavities. During bubble collapse, the Planck energy intrinsic to the cavity dimensions is converted to microwave photons that accumulate in the bubble wall molecules. Photons are emitted from the bubble wall molecules as the Planck energy accumulates to electronic levels.

关键词： Sonolluninescence Planck theory IRaser.

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Magnetoresistivity studies for BiPb-2223 phase added by BaSnO3 nanoparticles

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Journal of Advanced Ceramics 2017年第2期6卷 100-109页

作者： mai ME.BARAKAt Khulud HABANJAR Department of Physics Faculty of Science Alexandria University Alexandria Egypt Department of Physics Faculty of Science Beirut Arab University Beirut Lebanon

Co-precipitation method and conventional solid-state reaction technique were used to synthesize BaSnO3 nanoparticles and (BaSnO3)x/Bi1.6Pb0.4Sr2Ca2Cu3O10+δ (0≤x≤ 1.50w t％) samples,respectively.X-ray powder diffraction (XRD),scanning electron microscopy (SEM),and electrical resistivity data were used to characterize BiPb-2223 phase added by BaSnO3 *** relative volume fraction and superconducting transition temperature tc of BiPb-2223 phase were enhanced by increasing BaSnO3 addition up to 0.50 wt％.these parameters were decreased with further increase of *** resistive transition broadening under different applied DC magnetic fields (0.29-4.40kG) was analyzed through thermally activated flux creep (tAFC) model and Ambegaokar-Halperin (AH) *** of the derived flux pinning energy U,critical current density Jc (0) estimated from AH parameter C(B),and upper critical magnetic field Bc2 (0),were recorded by adding BaSnO3 nanoparticles up to 0.50 wt％,beyond which these parameters were *** magnetic field dependence of the flux pinning energy and critical current density decreased as a power-law relation,which indicated the single junction sensitivity between the superconducting grains to the applied magnetic ***,the increase in the applied magnetic field did not affect the electronic thermal conductivity Ke above the superconducting transition temperature and suppressed it below tc.

关键词： BiPb-2223 BaSnO3 nanoparticles flux pinning energy critical current density

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Modeling of Canonical Switching Cell Converter Using Genetic Algorithm

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Computer Modeling in Engineering & Sciences 2017年第1期113卷 109-116页

作者： t.v.viknesh v.Manikandan Department of Electrical and Electronics Engineering Coimbatore Institute of TechnologyCoimbatore-641014India

the working of Canonical switching cell(CSC)converter was studied and its equivalent circuit during ON and OFF states were *** space model of CSC converter in ON and OFF states were developed using the Kirchhoff *** state space matrices were used to construct the transfer functions of ON&OFF *** step response of the converter was simulated using *** step response curve was obtained using different values of circuit components(L,C1,C2 and RL)and *** characteristic parameters such as rise time,overshoot,settling time,steady state error and stability were determined using the step response *** response curve shows that there is no overshoot;the rise time and settling time are very low as expected for a converter and its stability is very high but the amplitude is *** circuit was tuned to attain the expected amplitude using PID controller with the help of Genetic *** excellent results of circuits’characteristic parameters are very useful guideline for constructing such CSC converters for DC-DC *** circuit characteristic parameters are useful in constructing such CSC converters for DCDC conversions in driving solar energy using solar panel.

关键词： Canonical switching cell converter state-space methods DC-DC converter step response stability power system modeling switching circuits genetic algorithm PID

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