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Analysis and optimization of performance parameters of the^(220)Rn chamber in flow-field mode using computational fluid dynamics method

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Nuclear Science and Techniques 2024年第10期35卷 70-85页

作者： Shao-Hua Hu Yong-Jun Ye Zheng-Zhong He de-tao xiao Xiang-Yu Xu Jian-Kai Wang Qing-Zhi Zhou School of Nuclear Science and Technology University of South ChinaHengyang 421001China School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China

The impact of the radiation dose produced by^(222)Rn/^(220)Rn and its progeny on human health has garnered increasing interest in the nuclear research *** establishment of robust,regulatory,and competent^(220)Rn chambers is crucial for accurately measuring radioactivity ***,studying the uniformity of the^(220)Rn progeny through experimental methods is challenging,because measuring the concentration of^(220)Rn and its progeny in multiple spatial locations simultaneously and in real time using experimental methods is ***,achieving precise control of the concentration of^(220)Rn and its progeny as well as the reliable sampling of the progeny pose significant *** solve this problem,this study uses computational fluid dynamics to obtain the flow-field data of the^(220)Rn chamber under different wind speeds and progenyreplenishment *** analysis of the concentration distribution of the progeny and quantitative analysis of the progeny concentration and uniformity of the progeny concentration are *** research findings indicated that the progeny concentration level is primarily influenced by wind speed and the progeny-complement *** speed also plays a crucial role in determining progeny concentration uniformity,whereas the progeny-complement rate has minimal impact on *** ensure the accuracy of^(220)Rn progeny concentration sampling,we propose a methodology for selecting an appropriate sampling area based on varying progeny *** study holds immense importance for enhancing the regulation and measurement standards of^(220)Rn and its progeny.

关键词： Thoron Progeny Regulatory CFD simulation

Rapid determination of radon monitor＇s calibration factors

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Nuclear Science and Techniques 2016年第5期27卷 188-192页

作者： Zhi-Qiang Li de-tao xiao Gui-Zhi Zhao Xi-Jun Wu Jian Shan Qing-Zhi Zhou Zheng-Zhong He University of South China Hengyang 421001 China Hengyang Normal University Hengyang 421008 China

The monitors used to measure radon concentration must be calibrated,and the calibration factor of each measurement cycle should be ***,the determination time of calibration factors of NRL-Ⅱ radon monitors should be *** this study,a method is proposed to determine the calibration factors of radon monitors *** the proposed method,the calibration factor is initially determined in the 60-min measurement cycle;the calibration factor is then identified in the other measurement cycle on the basis of the principle that the calibration factor of the same radon monitor in different measurement cycles is inversely proportional to the number of a particles produced by ^(218)Po decay in this *** demonstrate that the calculated calibration factor of the different measurement cycles is consistent with the experimental calibration ***,this method is reliable and can be used to determine the calibration factor of radon monitors rapidly.

关键词：校准因子氡浓度监测仪快速测定测量周期监测器测定时间校正因子

Adsorption and desorption of hydrogen on/from single-vacancy and double-vacancy graphenes

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Nuclear Science and Techniques 2019年第4期30卷 150-158页

作者： Xi-Jun Wu Ze-Jie Fei Wen-Guan Liu Jie Tan Guang-Hua Wang Dong-Qin Xia Ke deng Xue-Kun Chen de-tao xiao Sheng-Wei Wu Wei Liu School of Mathematics and Physics University of South China Shanghai Institute of Applied Physics Chinese Academy of Sciences Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen University Key Laboratory of Neutronics and Radiation Safety Institute of Nuclear Energy Safety Technology Chinese Academy of Sciences

Adsorption and desorption of hydrogen on/from single-vacancy and double-vacancy graphenes were studied by means of first-principles calculations. The structure and stability of continuous hydrogenation in single vacancy were investigated. Several new stable structures were found, along with their corresponding energy barriers. In double-vacancy graphene, the preferred sites of H atoms were identified, and H2 molecule desorption and adsorption of from/on were calculated from the energy barriers. This work provides a systematic and comprehensive understanding of hydrogen behavior on defected graphene.

关键词： Hydrogen Graphene Single vacancy Double vacancy Adsorption desorption First-principles calculation

Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

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Journal of Energy Chemistry 2025年第1期100卷 721-729页

作者： Guanyu Luo Min Song Lulu An xiao Huang Qian Zhang Chenhao Zhang tao Shen Shuang Wang deli Wang Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology) Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Integrating multi-scale sites in a composite catalyst is vital to realize efficient ***,a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds （IMCs）(o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction *** loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic *** remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic *** from the ordered structure,synergistic effect of Pt Co IMCs and Co single atoms,o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,***,o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for *** integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

关键词： Electrolytic reduction

Electrochemical conversion of methane to bridge the gap in the artificial carbon cycle

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Journal of Energy Chemistry 2025年第1期100卷 286-308页

作者： Yuhao Peng Yuefeng Song Ihar Razanau Juanxiu xiao Wei xiao Di Hu Guoxiong Wang College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Dalian Institute of Chemical Physics Chinese Academy of Sciences Laboratory of Physical-Chemical Technologies SSPA Scientific and Practical Materials Research Centre of NAS of Belarus State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University department of Chemical and Environmental Engineering University of Nottingham Ningbo China

Methane, an abundant one-carbon（C1） resource, is extensively used in the industrial production of vital fuels and value-added chemicals. However, current industrial methane conversion technologies are energy-and carbon-intensive, mainly due to the high activation energy required to break the inert C–H bond, low selectivity, and problematic side reactions, including CO2emissions and coke deposition. Electrochemical conversion of methane（ECM） using intermittent renewable energy offers an attractive solution, due to its modular reactor design and operational flexibility across a broad spectrum of temperatures and pressures. This review emphasizes conversion pathways of methane in various reaction systems, highlighting the significance and advantages of ECM in facilitating a sustainable artificial carbon cycle. This work provides a comprehensive overview of conventional methane activation mechanisms and delineates the complete pathways of methane conversion in electrolysis contexts. Based on surface/interface chemistry, this work systematically analyzes proposed reaction pathways and corresponding strategies to enhance ECM efficiency towards various target products, including syngas, hydrocarbons, oxygenates, and advanced carbon materials. The discussion also encompasses opportunities and challenges for the ECM process, including insights into ECM pathways, rational electrocatalyst design, establishment of benchmarking protocols, electrolyte engineering, enhancement of CH4conversion rates, and minimization of CO2emission.

关键词： Methane Electrochemical conversion Reaction mechanism Catalyst design Electrode Electrocatalysis

Fine-tuning the spatial allocation of phytohormones for smart canopy, smart breeding, and smart agriculture

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Science China Life Sciences 2025年第1期 309-310页

作者： tao Zhou Lin Li National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University HuBei HongShan Laboratory

The dual challenges of global climate change and population growth have increased demand for higher crop yields per unit area. The innovative technology of smart agriculture aims to synergize breeding, cultivation, and production through the application of biological and informatics technologies. Historically, the “Green Revolution” introduced semidwarf varieties of certain key crops by utilizing mutations affecting gibberellin pathways, which significantly increased planting densities and yields.

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Tumor inflammation-specific self-amplifying fluorescent molecular probes induce an anti-tumor immune response

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Science China Chemistry 2025年第1期 273-287页

作者： Shuguang Yang Lijun Hu Hong xiao Zecong xiao Xintao Shuai PCFM Lab of Ministry of Education School of Materials Science and Engineering Sun Yat-sen University department of Ultrasound The Fifth Affiliated Hospital Sun Yat-sen University department of Medical Ultrasound The Third Affiliated Hospital of Sun Yat-sen University Nanomedicine Research Center The Third Affiliated Hospital of Sun Yat-sen University

Enhancing the concentration of exogenous molecular drugs within the tumor microenvironment through enzyme-catalyzed polymerization presents a novel strategy for cancer therapy. Nonetheless, the optimization of the catalytic efficiency is often impeded by the inefficient expression of enzymes. Herein, we reported a self-amplifying fluorescent molecular probe, Bis-HTPICG, for photodynamic therapy(PDT) and subsequent PDT-induced immunoreaction. The Bis-HTP-ICG probe possesses a noticeable enzyme-catalyzed polymerization facilitated by myeloperoxidase(MPO), a crucial enzyme secreted by neutrophils at inflammation sites. Upon exposure to laser irradiation, Bis-HTP-ICG showed a high PDT efficacy, inducing an acute inflammatory response that stimulates further recruitment of neutrophils and then elevated MPO secretion. The heightened level of MPO enhances the accumulation of the Bis-HTP-ICG via self-polymerization or binding with intratumoral proteins following MPO enzyme catalysis, instigating a self-amplifying chain reaction cycle involving Bis-HTP-ICG, neutrophils and ***, PDT efficiently incites immunogenic cell death(ICD) in tumor cells, initiating an anti-tumor immune response including dendritic cells(DCs) maturation, T cell proliferation and reprogramming of tumor-associated neutrophils(TANs). This work portrays a promising strategy for self-amplification of fluorescent molecular probes through adjustable enzyme levels,potentially offering a unique avenue to enhance the tumor accumulation of molecular drugs for improved tumor therapy.

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design of a cationic accelerator enabling ultrafast ion diffusion kinetics in aqueous zinc-ion batteries

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Journal of Energy Chemistry 2025年第1期100卷 377-384页

作者： Yawei xiao Qianqian Gu Haoyu Li Mengyao Li Yude Wang National Center for International Research on Photoelectric and Energy Materials School of Materials and Energy Yunnan University Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources School of Chemistry and Chemical Engineering Hainan University College of Chemical Engineering Fuzhou University Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies Yunnan University

Aqueous zinc-ion batteries are highly favored for grid-level energy storage owing to their low cost and high safety,but their practical application is limited by slow ion *** address this,a strategy has been developed to create a cation-accelerating electric field on the surface of the cathode to achieve ultrafast Zn2+diffusion *** employing electrodeposition to coat MoS2on the surface of BaV6O16·3H2O nanowires,the directional built-in electric field generated at the heterointerface acts as a cation accelerator,continuously accelerating Zn2+diffusion into the active *** optimized Zn2+diffusion coefficient in CC@BaV-6O16·3H2O@MoS2(7.5×10～8cm2s-1) surpasses that of most reported V-based ***,MoS2serving as a cathodic armor extends the cycling life of the Zn-CC@BaV6O16·3H2O@MoS2full batteries to over 10000 *** work provides valuable insights into optimizing ion diffusion kinetics for high-performance energy storage devices.

关键词： Internal electric field Cationic accelerator Ion diffusion kinetics Cathode modification strategy Aqueous zinc ion battery

Inhibiting SHP2 reduces glycolysis, promotes microglial M1 polarization, and alleviates secondary inflammation following spinal cord injury in a mouse model

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Neural Regeneration Research 2025年第3期20卷 858-872页

作者： Xintian Ding Chun Chen Heng Zhao Bin Dai Lei Ye tao Song Shuai Huang Jia Wang tao You department of Orthopedics The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina department of Orthopedics Provincial Hospital Affiliated to Anhui Medical UniversityHefeiAnhui ProvinceChina

Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.

关键词： apoptosis glycolysis inflammatory response microglia neurons polarization spinal cord injury Src homology 2-containing protein tyrosine phosphatase 2