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Nitrogen-doped carbon dots as photocatalysts for organic synthesis:Effect of nitrogen content on catalytic activity

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Nano Research 2024年第6期17卷 4825-4833页

作者： Kai-Kai Niu Chao-Qun Ma Rui-zhi dong Hui liu Sheng-Sheng Yu Ling-Bao Xing School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000China

Regulating the doping of carbon dots(CDs)and the generation of reactive oxygen species(ROS)is essential to selectively control their application in photocatalytic organic *** study successfully synthesized five newly developed nitrogen-doped carbon dots(CDs 1-5)with varying nitrogen content,which have the ability to generate ROS when exposed to light radiation,specifically superoxide anion radicals(O_(2)•-)and singlet oxygen(^(1)O_(2)).The utilization of the aforementioned nitrogen-doped CDs as photocatalysts enables the realization of their potential in facilitating efficient photocatalytic organic ***,it was observed that the photocatalytic efficiency exhibited a gradual decrease when the nitrogen content in the CDs *** order to provide more evidence for this claim,we employed a set of five CDs in the context of photocatalytic dehalogenation ofα-bromoacetophenone,photocatalytic oxidative coupling reaction of amines to imines,photooxidation reaction of sulfides to sulfoxides,and cross-dehydrogenation coupling(CDC)reaction,in which it was further observed that there was a steady decrease in the yields of photocatalytic organic reactions as the nitrogen content in CDs ***,CDs 1 exhibited the best photocatalytic efficiency,thereby reinforcing the hypothesis that a higher nitrogen content corresponds to a decreased catalytic *** study not only investigates the impact of the nitrogen content on the catalytic performance of CDs,but also offers valuable insights for the future utilization of CDs for photocatalytic organic reactions in water.

关键词： carbon dots nitrogen-doped reactive oxygen species photocatalysis

Equivalence between the internal observability and equation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： liu Wen-jun TU zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

Quasi-2D weak lensing cosmological constraints using the PDF-SYM method

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 44-58页

作者： Zhenjie liu Jun Zhang Hekun Li zhi Shen Cong liu Department of Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai 200240China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

Cosmic shear statistics,such as the two-point correlation function(2PCF),can be evaluated with the PDF-SYM method instead of the traditional weighted-sum *** makes use of the full PDF information of the shear estimators,and does not require weightings on the shear estimators,which can in principle introduce additional systematic *** work presents our constraints on S8and?mfrom the shear-shear correlations using the PDF-SYM *** data we use is from the z-band images of the Dark Energy Camera Legacy Survey(DECa LS),which covers about 10000 deg2with more than 100 million *** shear catalog is produced by the Fourier Quad method,and well tested on the real data itself with the field-distortion *** main approach is called quasi-2D as we do use the photo-z information of each individual galaxy,but without dividing the galaxies into redshift *** mainly use galaxy pairs within the redshift interval between 0.2 and 1.3,and the angular range from 4.7 to 180 *** analysis yields S8=0.762±0.026 and?m=0.234±0.075,with the baryon effects and the intrinsic alignments *** results are robust against redshift *** check the consistency of our results by deriving the cosmological constraints from auto-correlations ofγ1andγ2separately,and find that they are consistent with each other,but the constraints from theγ1component are much weaker than that fromγ*** implies a much worse data quality ofγ1,which is likely due to additional shear uncertainties caused by CCD electronics(according to the survey strategy of DECa LS).We also perform a pure 2D analysis,which gives S8=0.81_(-0.04)^(+0.03)and?m=0.25_(-0.05)^(+0.06).Our findings demonstrate the potential of the PDF-SYM method for precision cosmology.

关键词： weak lensing shear-shear correlations cosmological parameters observations analysis

A robust tensor watermarking algorithm for diffusion-tensor images

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Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 384-397页

作者： Chengmeng liu zhi LI Guomei WANG Long ZHENG State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang 550025China

Watermarking algorithms that use convolution neural networks have exhibited good robustness in studies of deep learning ***,after embedding watermark signals by convolution,the feature fusion eficiency of convolution is relatively low;this can easily lead to distortion in the embedded *** distortion occurs in medical images,especially in diffusion tensor images(DTIs),the clinical value of the DTI is *** address this issue,a robust watermarking algorithm for DTIs implemented by fusing convolution with a Transformer is proposed to ensure the robustness of the watermark and the consistency of sampling distance,which enhances the quality of the reconstructed image of the watermarked DTIs after embedding the watermark *** the watermark-embedding network,Ti-weighted(Tlw)images are used as prior *** correlation between T1w images and the original DTI is proposed to calculate the most significant features from the T1w images by using the Transformer *** maximum of the correlation is used as the most significant feature weight to improve the quality of the reconstructed *** the watermark extraction network,the most significant watermark features from the watermarked DTI are adequately learned by the Transformer to robustly extract the watermark signals from the watermark *** results show that the average peak signal-to-noise ratio of the watermarked DTI reaches 50.47 dB,the diffusion characteristics such as mean diffusivity and fractional anisotropy remain unchanged,and the main axis deflection angleαAc is close to *** proposed algorithm can effectively protect the copyright of the DTI and barely affects the clinical diagnosis.

关键词： Robust watermarking algorithm Transformer Image reconstruction Diffusion tensor images Soft attention Hard attention Tl-weighted images

Ultrafast pulse-dilation framing camera and its application for time-resolved X-ray diagnostic

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Nuclear Science and Techniques 2024年第7期35卷 101-114页

作者： Hou-zhi Cai Qiu-Yan Luo Kai-Xuan Lin Xuan Deng Jun-Kai liu Kai-zhi Yang dong Wang Jia-Jie Chen Jia-Heng Wang Jing-Hua Long Li-Hong Niu Yun-Fei Lei Jin-Yuan liu Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province Shenzhen Key Laboratory of Photonics and BiophotonicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China

An ultrafast framing camera with a pulse-dilation device,a microchannel plate(MCP)imager,and an electronic imaging system were *** camera achieved a temporal resolution of 10 ps by using a pulse-dilation device and gated MCP imager,and a spatial resolution of 100μm by using an electronic imaging system comprising combined magnetic *** spatial resolution characteristics of the camera were studied both theoretically and *** results showed that the camera with combined magnetic lenses reduced the field curvature and acquired a larger working area.A working area with a diameter of 53 mm was created by applying four magnetic lenses to the ***,the camera was used to detect the X-rays produced by the laser-targeting *** diagnostic results indicated that the width of the X-ray pulse was approximately 18 ps.

关键词： Inertial confinement fusion Plasma diagnostics Framing camera Combined lenses Pulse-dilation

Normalized solutions of Kirchhoff equation with Hartree type nonlinearity

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Acta Mathematica Sinica,English Series 2024年

作者： Xiao Jing FENG Hai dong liu zhi Tao ZHANG School of Mathematical Sciences University of Chinese Academy of Sciences School of Mathematical Sciences Shanxi University HLM Academy of Mathematics and Systems Science Chinese Academy of Sciences Institute of Mathematics Jiaxing University School of Mathematical Sciences Jiangsu University Zhenjiang 212013 P.R.China

Consider the Kirchhoff equation with Hartree type nonlinearity ■ where a, b> 0,λ,μ∈R, 2 0, also known as normalized solutions, are of particular interest in the current paper. Under various assumptions onμ, c and q, we establish the existence, nonexistence and asymptotic behavior of normalized solutions for the above elliptic equation.

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Preparation and evaluation of a water-in-oil nanoemulsion drug delivery system loaded with salidroside

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Chinese Journal of Natural Medicines 2021年第3期19卷 231-240页

作者： LIANG Chun-Xia QI dong-Li ZHANG Li-Na LU Peng liu zhi-dong State Key Laboratory of Component-based Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjin 301617China Engineering Research Center of Modern Chinese Medicine Discovery and Preparation Technique Ministry of EducationTianjin University of Traditional Chinese MedicineTianjin 301617China

Salidroside(SAL)is a phenolic substance with high solubility and low permeability,which make it easy to cause the efflux effect of P-glycoprotein and degradation of intestinal flora,resulting in lower *** aim of this study was to develop and optimize a water-in-oil nanoemulsion of SAL(w/o SAL-N)to explore its suitability in oral drug delivery *** this work,SAL-N was successfully prepared by water titration method at K_(m)=1 to construct the pseudo-ternary phase *** characterization including the average viscosity,pH,refractive index,particle size,PDI,TEM,DSC,the content of SAL,and stability study were *** was evaluated for drug release in vitro and pharmacokinetic studies in *** optimized nanoemulsion formulation consisted of Labrafil M 1944 CS(63%),Span-80/Tween-80/EtOH(27%)and 200 mg·mL^(-1) SAL solution(SAL-SOL)(10%).Low viscosity and suitable pH were expected for the *** spherical morphology and nanoscale size of SAL-N enhanced the stability of the nanoemulsion *** vitro drug release showed that SAL-N had a better controlled release property than SAL-SOL at earlier time *** pharmacokinetic studies exhibited that SAL-N had significantly higher in t_(1/2)(2.11-fold),AUC_(0-48 h)(1.75-fold)and MRT0-48 h(2.63-fold)than SAL-SOL(P<0.01).The w/o SAL-N prepared in this work can be effectively delivered via the oral *** can be seen w/o nanoemulsion is a strategy for the drug with polyphenols to delay the release,enhance oral absorption and reduce metabolic rate.

关键词： Salidroside Water-in-oil nanoemulsion Polyphenol Drug release Pharmacokinetics Bioavailability

Nanopore design of sulfur doped hollow carbon nanospheres for superior potassium-ion battery anodes

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Rare Metals 2024年第5期43卷 2103-2114页

作者： Zhen-dong liu Hui-Yan Feng Yu-Chen Wang Fei Wang Yue liu Jian-Xiao Yang Yue Gu Jun Tan Chong Ye Cheng-zhi Zhang Ji Hua Laboratory Foshan 528000China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and EngineeringHunan UniversityChangsha 410082China

Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term *** design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling ***,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic *** finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.

关键词： Nanopore Carbon materials Sulfur doping Anode Potassium-ionbatteries

Research on the Dynamic Compressibility of Polyurethane Microcellular Elastomer and its Application for Impact Resistance

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Chinese Journal of Polymer Science 2024年第8期42卷 1185-1197页

作者： zhi-Ying Zhao Hao Jiang Xiao-dong Li Xu-dong Zhang Xing Su Mei-Shuai Zou School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

The packaging materials with cushioning performance are used to prevent the internal contents from being damaged by the impact and vibration of external *** polyurethane microcellular elastomers(PUMEs)can absorb energy through cell collapse and molecular chain *** this study,PUMEs with different densities were investigated by scanning electron microscopy,dynamic mechanical analysis and dynamic compression *** exhibited significant im pact resistance and the maximum peak stress attenuation ratio reached 73.33%.The protective equipment was made by PUME with the optimal density of 600 kg/m^(3),and then the acceleration sensing device installed with the same protective equipment fell from a height of 3,5 and 10 m to evaluate the energy-absorbing property and reusability of *** results showed that PUMEs equipment reduced the peak acceleration of the device by 93.84%,with a maximum deviation of 9%between actual test and simulation,and shortened the impact time of first landing by 57.39%.In addition,the equipment PUMEs equipment could effectively reduce the stress on the protected items.

关键词： Polyurethane microcellular elastomer Impact velocity Stress attenuation ratio Impact resistance