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Improved Hardy–Littlewood–Sobolev Inequality on S^(n)under Constraints

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Acta Mathematica Sinica,English Series 2023年第11期39卷 2149-2163页

作者： yun yun HU Jing bo DOU School of Mathematics and Statistics Shaanxi Normal UniversityXi’an 710119P.R.China

In this paper,we establish an improved Hardy–Littlewood–Sobolev inequality on Snunder higher-order moments ***,by constructing precise test functions,using improved Hardy–Littlewood–Sobolev inequality on S^(n),we show such inequality is almost optimal in critical *** an application,we give a simpler proof of the existence of the maximizer for conformal Hardy–Littlewood–Sobolev inequality.

关键词： Hardy–Littlewood–Sobolev inequality higher-order moments constraint concentration compactness principle almost optimal

Engineering versatile Au-based catalysts for solar-to-fuel conversion

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Journal of Energy Chemistry 2023年第8期83卷 341-362,I0010页

作者： Chunhua Wang Hongwen Zhang Feili Lai Zhirun xie yun Hau Ng bo Weng Xuejiao Wu Yuhe Liao Department of Chemistry KU LeuvenCelestijinenlaan 200F3001 LeuvenBelgium cMACS Department of Microbial and Molecular SystemsKU LeuvenCelestijnenlaan 200F3001 LeuvenBelgium School of Energy and Environment City University of Hong Kong83 Tat Chee AvenueKowloonHong Kong 999077China Centre for Sustainable Catalysis and Engineering Faculty of Bioscience EngineeringKU Leuven3001 LeuvenBelgium Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640GuangdongChina

Gold(Au) nanostructures(NSs) have been widely employed as cocatalysts to improve the photoactivity of semiconductor materials, while a systematic summary of the engineering approaches of Au NSs to maximize the solar-to-fuel conversion efficiency is still lacking. In this review, the recently developed strategies for elevating the overall photocatalytic performance of Au-based catalysts and the deep physical chemistry mechanisms are highlighted. Firstly, the synthetic approaches of Au NSs are summarized, followed by an elaboration on their multiple functions in improving photoactivity. Afterward, modification strategies of Au NSs used to enhance the photocatalytic efficiency of Au-semiconductor composites,including controlling the Au NSs morphology, size, crystal phase, defect engineering, alloying with different metals, modulating interfacial interaction, and introducing an external field, are summarized and discussed independently. Additionally, advanced characterization techniques that can provide insights into the charge dynamics of the photocatalysts are introduced. Finally, we share our opinion on the challenges and outline potentially promising opportunities and directions for efficient Au-based photocatalysis research moving forward. We sincerely look forward to this review can deliver insightful views to design efficient Au-based photocatalysts and spur certain innovations to other metal-based catalysts.

关键词： Au nanostructures Modification strategies Semiconductor Photocatalysis Solar-to-fuel conversion

Synthesis and Crystal Structure of N-[(3aR,4R,4aR,5aS,6S,6aS)-1,3-Dioxo-octahydro-4,6-ethenocyclopropa[f]isoindol-2(1H)-yl]-4-(trifluoromethyl)phenylmethanimine Monohydrate

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Chinese Journal of Structural Chemistry 2010年第7期29卷 1043-1046页

作者： ZHOU Xin-bo xie yun-De ZHONG Wu FAN Shi-Yong LI Song Institute of Pharmacology and Toxicology Academy of Military Medical Sciences Beijing 100850 China

The crystal structure of the title compound （C19H17F3N2O4, Mr = 394.35） was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/c with a = 28.383（6）, b = 10.355（2）, c = 12.799（3） A, β = 111.74（3）°, V= 3493.8（12） A3, Z = 8, De = 1.499 g,/cm3, λ（MoKα） = 0.71073, F（000） = 1632,μ = 0.127 mm^-1, R = 0.0412 and wR = 0.1019. In the title compound, there exist three intermolecular hydrogen interactions （O（4）...O（1）, 0（4）...0（3） and O（4）...N（1）） between water. The neighboring molecules are linked to each other generating a two-dimensional network structure via the three intermolecular hydrogen bonds and π-π interactions shaped by phen-phen with centroid distance of 4.049 A.

关键词： ST246 monohydrate crystal structure synthesis

Luminescence and Energy Transfer in Europium and Bismuth Codoped Trisodium Yttrium Silicates

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Chinese Physics Letters 2013年第8期30卷 173-177页

作者： xie Guo-bo Faculty of Computer Guangdong University of TechnologyGuangzhou 510006

Bi^(3+)and Eu^(3+)doped Na_(3)YSi_(2)O_(7) phosphors are prepared with solid state *** luminescence properties of Bi^(3+)and Eu^(3+)in Na_(3)YSi_(2)O_(7) and the energy transfer(ET)from Bi^(3+)to Eu^(3+)are investigated in *** ET mechanism is also ***^(3+)in Na_(3)YSi_(2)O_(7) emits near-ultraviolet(UV)light in a broad band peaking at 394 nm which can be attributed to the transition from excited states 3P0,1 to ground state 1S0 under the excitation of UV light with a wavelength of 309 ***^(3+)in Na_(3)YSi_(2)O_(7) emits orange and red *** co-doping of Bi^(3+)into Eu^(3+)doped Na_(3)YSi_(2)O_(7) introduces an intense absorption band from 270 to 350 nm due to ET from Bi^(3+)to Eu^(3+).The sensitization effect of Bi^(3+)on Eu^(3+)makes it possible that Bi^(3+)and Eu^(3+)co-doped Na_(3)YSi_(2)O_(7) could be used in AlGaN-based UV light emitting diodes as a red phosphor.

关键词： orange attributed excited

5-aza-2'-deoxycytidine in the regulation of antioxidant enzymes in retinal endothelial cells and rat diabetic retina

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International Journal of Ophthalmology(English edition) 2019年第1期12卷 1-7页

作者： Man-yun xie Yan Yang Ping Liu Yan Luo Shi-bo Tang Department of Ophthalmology the Second Xiangya HospitalCentral South University Hunan Clinical Research Center of Ophthalmic Diseas The State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen University Aier School of Ophthalmology Central South University Aier Research Institute of Ophthalmology

AIM: To investigate the roles of a DNA methyltransferase(DNMT) inhibitor 5-aza-2'-deoxycytidine(5-aza-dC) in the regulation of antioxidant enzymes in diabetic retinopathy(DR) models. METHODS: DNMTs expressions and activity, and changes of two key antioxidant enzymes in DR, MnSOD(encoded by SOD2 gene) and glutathione S-transferase theta 1(GSTT1), were quantified in the isolated human retinal endothelial cells(HRECs) exposed to high glucose(HG) with or without 5-aza-dC treatment. The downstream exacerbating factors including vascular endothelial growth factor(VEGF), intercellular adhesion molecule 1(ICAM-1) and matrix metalloproteinase 2(MMP2), which are implicated in the pathogenesis of DR and closely related to oxidative stress were also analyzed. The key parameters were confirmed in the retina from streptozotocin(STZ) diabetic rats. RESULTS: DNMTs expression and DNMT activity was induced in HRECs exposed to HG. Hyperglycemia decreased MnSOD and GSTT1 expression. 5-aza-dC administration effectively suppressed DNMTs expression and activity and reversed the MnSOD and GSTT1 expression under HG condition. VEGF, ICAM-1 and MMP2 induced by HG were also suppressed by 5-aza-dC treatment. Similar results were observed in the retina from STZ diabetic rats. CONCLUSION: Our findings suggest that DNA methylation may serves as one of the mechanisms of antioxidant defense system disruption in DR progression. Modulation of DNA methylation using pharmaceutic means such as DNMT inhibitors could help maintain redox homeostasis and prevent further progression of DR.

关键词： DNA methylation diabetic model 5-aza-dC oxidative stress inflammation human retinal endothelial cells rat

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

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Modulating sparks in a pulse train for repetitive and energy efficient plasma generation

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High Voltage 2023年第6期8卷 1168-1179页

作者： bo Yin Yifei Zhu yun Wu Institute of Aero‐Engine School of Mechanical EngineeringXi'an Jiaotong UniversityXi'anChina School of Electrical Engineering Xi'an Jiaotong UniversityXi'anChina Science and Technology of Plasma Dynamics Laboratory Airforce Engineering UniversityXi'anChina

Spark is a widely studied plasma source for active species production;however,it ex-periences unstable transitions(*** a thermal arc)at high frequencies or long pulse *** this study,the sparks generated in a pulse train were studied and modulated based on a physics‐corrected deep learning *** results show that a highly repeatable and stable spark plasma source can be achieved by automatically adjusting the voltage amplitude according to the discharge frequency in a high‐frequency pulse train within the time scale of the fluid *** influences of the electron number density increasing mode and modulated driven voltage profiles on the energy efficiencies were also studied.

关键词： Spark pulse energy

Building the toolbox for in vivo glia-to-neuron reprogramming

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Neural Regeneration Research 2024年第6期19卷 1171-1172页

作者： Ye xie bo Chen Departments of Ophthalmology and Neuroscience Icahn School of Medicine at Mount SinaiNew YorkNYUSA

Unlike regenerative-competent species that possess a remarkable intrinsic capacity to replenish lost neurons and restore neurocircuits spontaneously,the central nervous system in adult mammals lacks the ability to compensate for the neuronal loss caused by neurodegenerative diseases or traumatic injuries resulting in permanent loss of *** by earlier discoveries that radial glia or astrocytes isolated from the postnatal cortex can generate neurons.

关键词： injuries cortex diseases

Effects of Transition Metal Oxides on Thermal Conductivity of Mould Fluxes

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Journal of Iron and Steel Research International 2013年第11期20卷 27-32页

作者： QIU Xin xie Bing QING Xue-mei DIAO Jiang HUANG Qing-yun WANG Shui-bo College of Materials Science and Engineering Chongqing University Wuhan Iron and Steel Design and Research Institute Engineering Technology Company

The thermal conductivity of the mould fluxes containing transition metal oxides was measured by hotline method at different temperatures. The relationship between the thermal conductivity of mold fluxes and the contents of transition metal oxides was discussed. The synthetic slags were composed of 30.0% - 35.4%CaO, 34.7% - 38.6% SiO2, 6% Al2O3, 9% Na2O, 14.4% CaF2, 0-4% Cr2O3 and 0-8% MnO in mass percent. The results indicated that Cr2O3 and MnO had a negative effect on thermal conductivity of mold fluxes. The thermal conductivity of mold fluxes was about 0.25-0.55 W/（m · K） when the temperature reached 1 300 ℃, and it increased sharply to about 1.32-1.99 W/（m · K） when the temperature reduced from 1300 to 1000 ℃. The thermal conductivity of mold fluxes containing Cr2 O3 and MnO was 10 %- 25% lower than those of original fluxes. The decrease in thermal conductivity was attributed to the change of molecular structure of mold fluxes. In addition, the poor integrity and regulation of polycrystal structure, complexity of crystal structure, and effects of impurities in the boundary and lat- tice distortion leaded to the reduction in the thermal conductivity. Na2 CrO4, Mn2 SiO4 and other minor phases were also found in the samples containing Cr2O3 and MnO, respectively.

关键词： mould flux heat transfer transition metal oxide thermal conductivity