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Deterioration of equivalent thermal conductivity of granite subjected to heating-cooling treatment

Journal of Rock Mechanics and Geotechnical Engineering 2024年第10期16卷 4229-4246页

作者： Mohua Bu Peng Zhang Pingye Guo Jiamin Wang Zhaolong Luan Xin Jin State Key Laboratory for Geo-Mechanics and Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing100083China School of Qilu Transportation Shandong UniversityJinan250001China Academy of Deep Earth Sciences Chinese Institute of Coal ScienceBeijing100013China China State Key Laboratory of Coal Mining and Clean Utilization China Coal Technology and Engineering GroupBeijing100013China

Understanding the thermal conductivity of granite is critical for many geological and deep engineering *** heated granite was subjected to air-,water-,and liquid nitrogen(LN2-)coolings in this *** transient hot-wire technique was used to determine the equivalent thermal conductivity(ETC)of the granite before and after *** deterioration mechanism of ETC is analyzed from the ***,the numerical model is used to quantitatively study the impact of cooling rate on the microcrack propagation and heat conduction characteristics of *** results show that the ETC of granite is not only related to the heating temperature,but also affected by the cooling *** ETC of granite decreases nonlinearly with increasing heating temperature.A faster cooling rate causes a greater decrease in ETC at the same heating *** higher the heating temperature,the stronger the influence of cooling rate on *** main explanation for the decrease in ETC of granite is the increase in porosity and microcrack density produced by the formation and propagation of pore structure and microcracks during heating and *** analysis displays that the damage of granite at the heating stage is induced by the difference in thermal expansion and elastic properties of mineral *** the cooling stage,the faster cooling rate causes a higher temperature gradient,which in turn produces greater thermal *** a result,it not only causes new cracks in the granite,but also aggravates the damage at the heating stage,which induces a further decrease in the heat conduction performance of granite,and this scenario is more obvious at higher temperatures.

关键词： Equivalent thermal conductivity(ETC) Granite Heating-cooling treatment Pore structure Microcrack Grain-based model

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High-selectivity electroreduction of low-concentration CO_(2)with large concentration fluctuation

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science China Chemistry 2025年第4期68卷 1620-1626页

作者： Mengyu Qi Yanbin Ma Chao Zhang Bingwei Li Xueqing Yang Zhaolin Shi Simeng Liu Changhua An Jiqing Jiao Tongbu Lu MOE International Joint Laboratory of Materials Microstructure Analysis and Testing CenterInstitute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringSchool of Chemistry and Chemical EngineeringTianjin University of TechnologyTianjin 300384China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) NankaiUniversityTianjin 300071China

Electrochemical CO_(2)reduction reaction(CO_(2)RR)has been regarded as one of the most promising solutions to achieving“zero carbon emission”.In most of the CO_(2)RR-related studies;high-purity CO_(2)has been employed as the feed gas;however;in practice;CO_(2)is generally emitted in low concentrations;so it is of great significance to realize high-selectivity electroreduction of low-concentration CO_(2)with large concentration *** this work;we constructed a dual-active-site catalyst and successfully achieved CO_(2)local enrichment and conversion for low-concentration CO_(2).Operando experiments reveal that the catalyst has one type of site for activating CO_(2)and one type of site for binding the reaction *** dual-active-site catalyst displays a selectivity for formic acid consistently above 97%over a broad potential window(from-0.9 to-1.6 V ***).Even when fed with a low-concentration CO_(2)stream(volume ratio from 50%down to 10%);the dual-active-site catalyst could display high activity and selectivity(>91%).In particular;the selectivity is still above 85%when the CO_(2)volume ratio is as low as 5%.This work offers a feasible route for converting low-concentration CO_(2)via a synergistic effect for dual-active-site catalysts.

关键词： electrochemical CO_(2)reduction low-concentration CO_(2) high-selectivity dual-active-site catalyst operando infrared spectroscopy

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Identification of a novel caspase cleavage motif AEAD

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Virologica Sinica 2024年第5期39卷 755-766页

作者： Yujie Fang Zhou Gong Miaomiao You Ke Peng State Key Laboratory of Virology Center for Antiviral ResearchCenter for Biosafety Mega-ScienceWuhan Institute of VirologyChinese Academy of SciencesWuhan430207China University of Chinese Academy of Sciences Beijing100049China State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of SciencesWuhan430071China Provincial Key Laboratory of Jiangxia Wuhan430207China

Infections of many viruses induce caspase activation to regulate multiple cellular pathways,including programmed cell death,immune signaling and *** of caspase cleavage sites and substrates are important for understanding the regulation mechanisms of caspase ***,we identified and analyzed a novel caspase cleavage motif AEAD,and confirmed its caspase dependent cleavage activity in natural substrate,such as nitric oxide-associated protein 1(NOA1).Fusing the enhanced green fluorescent protein(EGFP)with the mitochondrial marker protein Tom20 through the AEAD motif peptide localized EGFP to the *** the activation of caspase triggered by Sendai virus(SeV)or herpes simplex virus type 1(HSV-1)infection,EGFP diffusely localized to the cell due to the caspase-mediated cleavage,thus allowing visual detection of the virusinduced caspase *** AEAD peptide-derived inhibitor Z-AEAD-FMK were developed,which significantly inhibited the activities of caspases-1,-3,-6,-7,-8 and-9,exhibiting a broad caspase inhibition *** inhibitor further prevented caspases-mediated cleavage of downstream substrates,including BID,PARP1,LMNA,pro-IL-1β,pro-IL-18,GSDMD and GSDME,protecting cells from virus-induced apoptotic and pyroptotic cell ***,our findings provide a new perspective for the identification of novel caspase cleavage motifs and the development of new caspase inhibitors and anti-inflammatory drugs.

关键词： Caspase AEAD motif Inhibitor Virus Cell death

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Enzymatically prepared alginate oligosaccharides improve broiler chicken growth performance by modulating the gut microbiota and growth hormone signals

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Journal of Animal science and Biotechnology 2023年第5期14卷 2107-2127页

作者： A La Teng Zhu La Yuqing Feng Die Hu Yimei Feng Xiaolu Jin Dan Liu Yuming Guo Gong Cheng Yongfei Hu State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Background Alginate oligosaccharide(AOS)holds great potential as a novel feed supplement in farm ***,the effects of AOS on chicken health and the underlying mechanisms are not fully *** study aimed to optimize the enzymatic preparation of AOS by using bacterial alginate lyases expressed in yeast,investigate the effects of the prepared AOS on the growth performance and gut health of broiler chickens,and reveal the underlying *** Five alginate lyases from bacteria were cloned into Pichia pastoris GS115 and the alginate lyase PDE9 was expressed at relatively high yield,activity and stability in *** trials were carried out using 3201-day-old male Arbor Acres broilers(four groups;8 replicates/group×10 chicks/replicate)receiving either a basal diet or the same diet supplemented with 100,200 and 400 mg/kg PDE9-prepared AOS for 42 *** results showed that dietary supplementation of 200 mg/kg AOS displayed the highest activity in promoting the birds’ADG and ADFI(P<0.05).AOS ameliorated the intestinal morphology,absorption function and barrier function,as indicated by the enhanced(P<0.05)intestinal villus height,maltase activity,and the expression of PEPT,SGLT1,ZNT1,and *** also increased serum insulin-like growth factor-1,ghrelin(P<0.05),and growth hormone(P<0.1).Moreover,the concentrations of acetate,isobutyrate,isovalerate,valerate,and total SCFAs in cecum of birds fed AOS were significantly higher than the control birds(P<0.05).Metagenomic analysis indicated that AOS modulated the chicken gut microbiota structure,function,and microbial interactions and promoted the growth of SCFAs-producing bacteria,for example,Dorea sp.002160985;SCFAs,especially acetate,were found positively correlated with the chicken growth performance and growth-related hormone signals(P<0.05).We further verified that AOS can be utilized by Dorea *** grow and to produce acetate in *** We demonstrated that the enzymatically

关键词： Acetate Alginate lyases Alginate oligosaccharides Dorea sp. Gut microbiota

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A bibliometric analysis of molybdenum-based nanomaterials in the biomedical field

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Tungsten 2024年第1期6卷 17-47页

作者： Zhi-Qiang Wang Ya-Wen Pan Jing Wu Hong-Bin Qi Shuang Zhu Zhan-Jun Gu School of Science China University of GeosciencesBeijing 100083China CAS Key Laboratory for Biomedical Eff ects of Nanomaterials and Nanosafety Institute of High Energy PhysicsBeijing 100049China CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology of ChinaChinese Academy of SciencesBeijing 100190China College of Materials Science and Optoelectronic Technology University of Chinese Academy of SciencesBeijing 100049China

Molybdenum(Mo)-based nanomaterials have been widely used in biomedical fields due to their various nanostructures and unique physical/chemical *** various reviews have described the development of Mo-based materials in the biomedical field,an objective and comprehensive summary and analysis of research trends in this field is still ***,we used the bibliometric analysis method to analyze all relevant literature on the biological application of Mobased nanomaterials in recent ***,we use bibliometric tools to analyze the dataset by year,country/region,institution and research hotspot to obtain the research ***,based on objectively identified research hotspots,the biomedical applications of Mo-based nanomaterials are reviewed comprehensively,mainly including sensors,cancer imaging/therapy and antibacterial ***,we discussed the application prospects and challenges of Mo-based *** article provides a new perspective to understand the current research progress and further promote the development of Mobased nanomaterials in biomedical research.

关键词： Molybdenum Nanomaterial Biomedicine Bibliometric analysis

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Multiscale causes of the 2022 Yangtze mega-flash drought under climate change

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science China Earth sciences 2024年第8期67卷 2649-2660页

作者： Xing YUAN Yumiao WANG Shiyu ZHOU Hua LI Chenyuan LI School of Hydrology and Water Resources Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources Nanjing University of Information Science and TechnologyNanjing 210044China

The 2022 Yangtze mega-flash drought is characterized by strong intensity and rapid development both in time and space,accompanied by a persistent anticyclonic circulation ***,the causes of the extreme event remain elusive given the multiscale nature of *** we presented a brief overview for the oceanic and terrestrial causes of the megaflash drought during the summer of 2022,and estimated the risk in a changing *** the soil moisture percentile as the drought index,it was found that the drought expanded to the entire Yangtze River basin within two months,with 80%of basin under severe drought conditions at the end of *** the intensity and onset speed of the 2022 mega-flash drought were ranked as the first during the past 62 years,with return periods of 86 and 259 years,*** results of composite analysis showed that the spring La Ni?a can facilitate the abrupt change from a wet/normal condition in May–June to drought in July–August over the Yangtze River basin,which was beneficial for the increase of flash drought intensity and onset speed *** analysis through the linear regression also indicated that the unprecedented intensity was associated with the negative phase of the Pacific Decadal *** by a coupling strength index for soil moisture and vapor pressure deficit,it was found that there was a strong land-atmosphere coupling over the Yangtze River basin during July–August *** attribution by using CMIP6 climate models suggested that land-atmosphere coupling increased the risks of flash drought intensity and onset speed like 2022 by 61%±6%and 64%±7%under natural climate forcings,and the synergy of coupling and anthropogenic climate change would increase the risks by 75%±22%and 85%±12%.Our findings emphasized the role of landatmosphere coupling combined with anthropogenic climate change in intensifying flash droughts.

关键词： Flash drought Yangtze River basin Land-atmosphere coupling Climate change Attribution

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Fluorescence analysis of antibiotics and antibiotic-resistance genes in the environment: A mini review

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Chinese Chemical Letters 2024年第10期35卷 82-91页

作者： Yuxin Li Chengbin Liu Qiuju Li Shun Mao College of Environmental Science and Engineering State Key Laboratory of Pollution Control and Resource ReuseTongji UniversityShanghai 200092China Institute for Agri-food Standards and Testing Technology Shanghai Academy of Agricultural SciencesShanghai 201403China

Antibiotics,as widely used antibacterial drug,exist in various environmental *** residues can affect biological metabolism and lead to bacterial resistance and the formation of antibiotic-resistance genes,posing a threat to human health and ecological *** efficient detection methods for antibiotics and antibiotic-resistance genes has great environmental *** detection methods,due to their fast response,high sensitivity and specificity,and low-cost,are widely used in chemical and biological *** review first summarizes the pre-treatment methods for different types of environmental samples,and then focuses on the recent advances of fluorescence methods for the detection of antibiotics and antibiotic-resistance ***,main challenges and future research directions of fluorescence methods for antibiotic and antibiotic-resistance genes detection are *** review highlights the promising prospect of fluorescence methods in-situ detection and monitoring of antibiotics and antibiotic-resistance genes,and provides guidance for the construction of overall risk assessment system of environmental media.

关键词： Antibiotics Antibiotic-resistancegenes Fluorescence detection Environmental samples In-situdetection

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Massive Outbreak of Red Sprites in South Asia Observed from the Tibetan Plateau

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Advances in Atmospheric sciences 2025年第6期42卷 1247-1260页

作者： Hailiang HUANG Gaopeng LU Angel AN Di XU Zhengwei CHENG Yongping WANG Yazhou CHEN Xin HUANG School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Beijing 100000 China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China MNR Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China National Key Laboratory on Electromagnetic Environment Effects Shijiazhuang Campus of AEUShijiazhuang 050003China

On 19 May 2022, an outbreak of 105 red sprites that occurred over South Asia was fortuitously recorded by two amateurs from a site in the southern Tibetan Plateau(TP), marking the highest number captured over a single thunderstorm in South Asia. Nearly half of these events involved dancing sprites, with an additional 16 uncommon secondary jets and at least four extremely rare green emissions called “ghosts” observed following the associated sprites. Due to the absence of the precise timing needed to identify parent lightning, a method based on satellite motion trajectories and star fields is proposed to infer video frame timestamps within an error of less than one second. After verifying 95 sprites from two videos, our method identified the parent lightning for 66 sprites(~70%). The sprite-producing strokes, mainly of positive polarity with peak currents exceeding +50 k A, occurred in the stratiform region of a mesoscale convective complex(MCC)that spanned the Ganges Plain to the southern TP, with a cloud area over 200 000 km2 and a minimum cloud-top black body temperature near 180 K. This observation confirms that thunderstorms in South Asia, akin to mesoscale convective systems(MCSs) in the Great Plains of the United States or coastal thunderstorms in Europe, can produce numerous sprites,including complex species. Our analysis bears important implications for characterizing thunderstorms above the southern TP and examining their physical and chemical effects on the adjacent regions, as well as the nature of the coupling between the troposphere and middle-upper atmosphere in this region.

关键词： red sprites Tibetan Plateau South Asia parent lightning strokes satellite trajectory mesoscale convective complex

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Characterization of creep cavities in P91 steel and analysis of their formation patterns based on industrial CT 5

Characterization of creep cavities in P91 steel and analysis...

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2024 5th International Conference on Advanced Materials and Intelligent Manufacturing, ICAMIM 2024

作者： Shi, Yan Xu, Yi Hu, Jiansheng Chen, Jichang Chen, Yun Cao, Huiquan Wang, Liqin Tang, Ping Zhejiang Academy of Special Equipment Science Hangzhou China Key Laboratory of Special Equipment Safety Testing Technology of Zhejiang Province Hangzhou China

Creep cavities constitute a quintessential form of creep degradation in P91 steel, serving as an indicator for evaluating the residual creep life. In this study, industrial CT was employed to examine the creep and tensile fracture surfaces of P91 steel specimens exhibiting both normal high hardness and anomalously low hardness, respectively, and the formation patterns of creep cavities were analyzed. It was discovered that a moderate increase in the number of scanning frames coupled with the implementation of beam hardening correction enhanced the quality of industrial CT images depicting creep cavities. Creep cavities, around 20 μm in size, were observed beneath the fibrous zone of the fracture samples;their genesis was attributed to the coalescence of micro-voids during the tertiary stage of creep. Specimens with high hardness presented a greater abundance of creep cavities compared to those with low hardness, whereas the latter exhibited more cavities than those generated by tensile processes. The elucidation of the formation patterns of creep cavities may provide technical support for the grading of aging in the microstructure of P91 steel. 2025 Published under licence by IOP Publishing Ltd.

关键词： Rockwell hardness

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Enhancing the peroxidase-like activity of MoS_(2)-based nanozymes by introducing attapulgite for antibacterial application and sensitive detection of glutathione

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Nano Research 2024年第8期17卷 7415-7426页

作者： Feng Feng Yihe Zhang Xiao Zhang Bin Mu Jiahe Zhang Wenjie Qu Wangshu Tong Minmin Liang Qi An Zhanjun Guo Lu Zhao Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid WastesNational Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Clay Mineral Applied Research of Gansu Province Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Experimental Center of Advanced Materials School of Materials Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China

Nanozymes are next-generation of nanomaterials with enzyme-like *** particular,nanozymes with peroxidase(POD)-like activity have been utilized in various fields,including antibacterial,detection,degradation,***,their extensive applications were limited by their low catalytic activity ***,we have presented a composite nanozyme based on attapulgite(ATP)(Fe-ATP-MoS_(2)(FAM)),which exhibited enhanced POD-like activity(185.33 U·mg^(−1)),4.25 times higher than that of Fe-MoS_(2)(FM)(43.63 U·mg^(−1)).The density functional theory(DFT)calculations indicated that the addition of ATP increased the electron density of metal centers(Mo and Fe).More importantly,Michaelis–Menten kinetics revealed that the introduction of ATP significantly enhanced the binding affinities of substrates through the pores of ATP,forming a highly concentrated substrate microenvironment and thus promoting its POD-like ***,from molecular size and kinetic analysis,we proposed that the changes in substrate size before and after oxidation also significantly affected its Michaelis-constant(Km)***,we utilized FAM in the applications of highly effective antibacterial application and sensitive detection of glutathione(GSH).In conclusion,this work provides a novel approach for designing a highly efficient nanozyme based on natural mineral composites.

关键词： attapulgite peroxidase electron density affinity antibacterial

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