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Mechanical behavior and failure mechanism of polyurea nanocomposites under quasi-static and dynamic compressive loading

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Defence Technology（防务技术） 2021年第2期17卷 495-504页

作者： Qiang Liu Peng-wan Chen yan-song guo Jian-jun Su Lu Han Ali Arab Jian-fei Yuan State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Xi’an Modern Chemistry Research Institute Xi’an 710065China

Polyurea is an elastomeric material that can be applied to enhance the protection ability of structures under blast and impact *** order to study the compressive mechanical properties of SiC/polyurea nanocomposites under quasi-static and dynamic loading,a universal testing machine and split Hopkinson pressure bar(SHPB)apparatus were used *** stress-strain curves were obtained on polyurea and its composites at strain rates of 0.001e8000 s*** results of the experiment suggested that increase in the strain rates led to the rise of the flow stress,compressive strength,strain rate sensitivity and strain *** indicates that all of the presented materials were dependent on strain ***,these mechanical characters were enhanced by incorporating a small amount of SiC into polyurea *** relation between yield stress and strain rates were established using the power law ***,in order to investigate the fracture surfaces and inside information of failed specimens,scanning electron microscopy(SEM)and micro X-ray computed tomography(micro-CT)were used *** voids,crazes,micro-cracks and cracking were observed in fracture *** the other hand,the cracking propagation was found in the micro-CT slice *** is essential to understand the deformation and failure mechanisms in all the polyurea materials.

关键词： Polyurea nanocomposites Mechanical properties Strain rate Micro-CT Failure

Syntheses,Crystal Structures and Fluorescent Properties of Two Zinc Complexes Assembled by Bis(imidazol)Ligands

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Chinese Journal of Structural Chemistry 2020年第10期39卷 1885-1891,1745页

作者： LV Meng-Ying LV Cong yan guo-song ZHOU Shi JIANG Wei LIU Bo LI Xiu-Mei Key Laboratory of Preparation and Applications of Environmental Friendly Materials(Jilin Normal University) Ministry of EducationChangchun 130103Chin Faculty of Chemistry Tonghua Normal UniversityTonghua 134002China

Two new complexes[Zn(nph)(bix)]n·nH2O(1)and[Zn(nba)2(bix)]n(2)(H2nph=4-nitrophthalic acid,Hnba=4-nitrobenzoic acid,bix=1,4-bis(imidazol-1-yl)-benzene)have been hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum,fluorescence spectrum,single-crystal and power X-ray *** 1 exhibits a three-dimensional(3D)framework,which is stabilized through C–H…O hydrogen bonds andπ-πstacking *** 2 shows a zero-dimensional structure,which is further extended into a three-dimensional supramolecular structure through C–H…O and C–H…N hydrogen bonding interactions.

关键词： hydrothermal synthesis crystal structure Zn(Ⅱ)complex 1 4-bis(imidazol-1-yl)-benzene

Zooplankton community composition in summers of 2021and 2022 in the northern East China Sea and Yellow Sea,and their linkage with abiotic and biotic factors

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Journal of Oceanology and Limnology 2025年第1期43卷 159-176页

作者： Dongjie guo Fang ZHANG Shuangyan ZHANG song SUN CAS Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China College of Marine Science University of Chinese Academy of SciencesQingdao 266071China Jiaozhou Bay National Marine Ecosystem Research Station Institute of OceanologyChinese Academy of SciencesQingdao 266071China

The northern East China Sea and Yellow Sea are highly dynamic marginal seas,serving as important fishing grounds and primary areas for *** zooplankton community structure,including abundance,biovolume,and normalized biovolume size spectra(NBSS)within this ecosystem in summers 2021 and 2022 was assessed through ZooScan digital imaging *** abundances of zooplankton in summers 2021 and 2022 were 3364.22±2190.53 and 4435.52±2520.06 inds./m^(3),respectively,whereas the corresponding biovolumes were 649.10±519.63 and 1064.86±1254.87 mm^(3)/m^(3),*** copepods as the dominant zooplankton functional group in terms of abundance in both years,while chaetognath and medusae were the dominant groups in terms of *** dominance of medusae and chaetognath in terms of biovolume,along with the flatter slopes of NBSS compared to a stable community,indicated that more energy accumulated in gelatinous organisms within the study *** were significant positive relationships between temperature and tunicates or medusae,with a significantly higher population size observed in summer 2022 than in *** lower abundance and biovolume of zooplankton,mainly of small copepods,in summer 2021 may be related to the larger population size of the large jellyfish and the proliferation of green *** investigation provided basic data and fundamental insights for achieving a comprehensive understanding of zooplankton community structure and their long-term dynamics.

关键词： zooplankton community spatial distribution global warming Nemopilema nomurai Ulva prolifera

Laparoscopy-assisted D2 radical distal gastrectomy for advanced gastric cancer： initial experience

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Chinese Medical Journal 2009年第12期122卷 1404-1407页

作者： DU Xiao-hui LI Rong CHEN Lin SHEN Di LI song-yan guo Qiang Department of General Surgery General Hospital of PLA Beijing 100853 China

Background Laparoscopy-assisted radical gastrectomy is gaining acceptance for treating early gastric cancer. However, few reports concerning the effectiveness of laparoscopy-assisted D2 radical distal gastrectomy （LADG） for advanced gastric cancer or data comparing the results obtained after open distal gastrectomy （ODG） are yet available. The aim of this study was to evaluate the method, feasibility and clinical result of LADG for advanced gastric cancer. Methods A retrospective study was performed comparing LADG and ODG for advanced gastric cancer. Seventy-eight patients who underwent LADG were compared with 90 patients who underwent ODG in terms of pathologic findings, operative outcome, and complications. Results There was no conversion to open surgery in the LADG group and no postoperative mortality of any patients. There were no significant differences between LADG and ODG in operative time （（245±35） vs （220±620） minutes）, complication rate （7.7% vs 10.0%）, and number of lymph nodes （23.5±6.0 vs 21.0±7.5）, while the blood loss was less after LADG （（110±25） vs （196±30） ml, P 〈0.05）. The time to postoperative flatus and postoperative hospital stay were shorter after LADG （（73.0±8.5） vs （102.0±10.5） hours, and （8.6±1.2） vs （12.1 ±2.5） days, P 〈0.05, respectively）. Conclusion LADG for advanced gastric cancer is feasible, safe, and minimally invasive.

关键词： gastric cancer laparoscopic distal gastrectomy minimally invasive surgery lymph node dissection

Gradient age-precipitation behavior induced by gradient nano-grain in Mg-Gd-Ag-Zr alloy

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Journal of Iron and Steel Research International 2025年第1期32卷 19-24页

作者： Bang-jun Li Jia-peng Sun Jing Han guo-song Wu College of Materials Science and Engineering Hohai UniversityNanjing 210024JiangsuChina School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116JiangsuChina

Gradient nano-grained structure is frequently engineered into metallic materials,including Mg alloys,to achieve superior combination of strength and ***,the influence of this microstructural feature on aging precipitation behavior remains inadequately *** this study,the age-precipitation behavior of a gradient nano-grained Mg-Gd-Ag-Zr alloy prepared via ultrasonic severe surface rolling was *** result indicates that the aging precipitation behavior exhibits a depth-dependent variation within this *** the nano-grained surface layer,hierarchicalβnano-precipitates are predominant,while at greater depths,the precipitates consist ofβnanoparticles located at grain boundaries,along with intragranularβ′andγ″*** formation ofβnano-precipitates deviates from the conventional precipitation behavior observed in Mg-Gd-Ag alloys,and is attributed to the high density of defects induced by the surface nano-grained *** finding advances our understanding of the precipitation behavior in the alloys with heterogeneous microstructure.

关键词： Mg alloy Gradient Precipitation Aging behavior Microstructure

Impact of probiotics-derived extracellular vesicles on livestock gut barrier function

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Journal of Animal Science and Biotechnology 2025年第1期16卷 34-48页

作者： Yuhan Zhang Mengzhen song Jinping Fan Xuming guo Shiyu Tao College of Animal Sciences and Technology Huazhong Agricultural UniversityNo.1 Shizishan StreetHongshan DistrictWuhanHubei Province 430070China

Probiotic extracellular vesicles(pEVs)are biologically active nanoparticle structures that can regulate the intestinal tract through direct or indirect *** enhance the intestinal barrier function in livestock and poultry and help alleviate intestinal *** specific effects of pEVs depend on their internal functional components,including nucleic acids,proteins,lipids,and other *** paper presents a narrative review of the impact of pEVs on the intestinal barrier across various segments of the intestinal tract,exploring their mechanisms of action while highlighting the limitations of current *** the mechanisms through which probiotics oper-ate via pEVs could deepen our understanding and provide a theoretical foundation for their application in livestock production.

关键词： Extracellular vesicles Intestinal barrier Livestock production Probiotics

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碟形轴对称无人直升机总体设计

南京航空航天大学学报 2005年第4期37卷 479-484页

作者：吴剑邵松宋彦国张呈林南京航空航天大学直升机旋翼动力学国家重点实验室南京210016

在研究碟形轴对称无人直升机气动特性的基础上,选择碟形无人直升机总体参数并提出了一个总体方案;给出了碟形无人直升机的飞行性能计算方法;建立了碟形无人直升机飞行动力学模型,分析碟形无人直升机的操纵性和稳定性,并进行飞行仿真验... 详细信息

在研究碟形轴对称无人直升机气动特性的基础上,选择碟形无人直升机总体参数并提出了一个总体方案;给出了碟形无人直升机的飞行性能计算方法;建立了碟形无人直升机飞行动力学模型,分析碟形无人直升机的操纵性和稳定性,并进行飞行仿真验证。结果表明:本文提出的碟形无人直升机的总体设计方案和设计方法是可行的。

关键词：无人直升机碟形轴对称总体设计仿真

Metrological traceable calibration of organic carbon and elemental carbon based on laboratory-generated reference materials

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Journal of Environmental Sciences 2025年第3期149卷 524-534页

作者： Yue Liu Junjie Liu Ji Xiao Jing Ye Lixu guo Caiqing yan Center for Environmental Metrology National Institute of Metrology ChinaBeijing 100029China College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030024China Environment Research Institute Shandong UniversityQingdao 266237China

Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate *** measurement of carbonaceous aerosol is essential to reduce the uncertainty of radiative forcing estimation and source *** accurate separation of OC and EC is controversial due to the charring of ***,the development of reference materials(RM)for the validation of OC/EC separation is an important basis for further *** RMs were mainly based on ambient air sampling,which could not provide traceability of OC and EC *** develop traceable RMs with known OC/EC contents,our study applied an improved aerosol generation and mixing technique,providing uniform deposition of particles on quartz *** generate OC aerosol with similar pyrolytic property of ambient aerosol,both water soluble organic carbon(WSOC)and water insoluble organic carbon(WIOC)were used,and amorphous carbon was selected for EC *** RMs were analyzed using different *** homogeneity within the filter was validated,reaching below 2%.The long-term stability of RMs has been validated with RSD ranged from 1.7%–3.2%.Good correlationwas observed between nominal concentration of RMswithmeasured concentration by two protocols,while the difference of EC concentration was within 20%.The results indicated that the newly developed RMs were acceptable for the calibration of OC and EC,which could improve the accuracy of carbonaceous aerosol ***,the laboratory-generated EC-RMs could be suitable for the calibration of equivalent BC concentration by Aethalometers.

关键词： Carbonaceous aerosol Split point Reference material Laboratory-generated Traceability

Artificial intelligence advances drug delivery system and its clinical transition

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Science Bulletin 2025年第3期70卷 305-308页

作者： Hui Wang Xiao-yan You guo-Ping Zhao Master Lab for Innovative Application of Nature Products National Center of Technology Innovation for Synthetic BiologyTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences(CAS)Tianjin 300308China Henan Engineering Research Center of Food Microbiology College of Food and BioengineeringHenan University of Science and TechnologyLuoyang 471023China Haihe Laboratory of Synthetic Biology Tianjin 300308China CAS-Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China CAS Key Laboratory of Quantitative Engineering Biology Shenzhen Institute of Synthetic BiologyShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Since November 2022,ChatGPT,an artificial intelligence(AI)chatbot,has rapidly captured global attention for its detailed responses and articulated answers across a broad spectrum of knowledge domains[1],[2].All industries will reorient around it,prompting a reevaluation of how this technology could further promote scientifical research and its clinical applications.

关键词： system transition spectrum