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位涡源汇和位涡环流及其天气气候意义

大气科学 2024年第1期48卷 8-25页

作者：吴国雄刘屹岷毛江玉何编包庆谢永坤生宸马婷婷李言蹊中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG) 北京100029 中国科学院大学北京100049 兰州大学西部生态安全协同创新中心兰州730000

在扼要回顾地表位涡研究进展的基础上,本文介绍了复杂地形下的位涡及位涡制造的计算及近年来关于位涡源汇和位涡环流(PVC)的研究进展,侧重介绍青藏高原表层位涡的特殊性及其对天气气候的重要影响。阐明对于绝热和无摩擦大气运动,由于位... 详细信息

在扼要回顾地表位涡研究进展的基础上,本文介绍了复杂地形下的位涡及位涡制造的计算及近年来关于位涡源汇和位涡环流(PVC)的研究进展,侧重介绍青藏高原表层位涡的特殊性及其对天气气候的重要影响。阐明对于绝热和无摩擦大气运动,由于位涡本身的结构重组(位涡重构)可以引起垂直涡度的发展,在夏季可以激发高原涡形成,冬季使青藏高原东部成为重要的表面涡源。基于导得的包括非绝热加热作用的、与等熵面的位移相联系的垂直运动(ωID)方程,进一步阐明青藏高原制造的正位涡沿西风气流东传会引起下游地区低空气旋性涡度、偏南风、和上升运动发展,导致位涡平流随高度增加,激发极端天气气候事件发生发展。指出青藏高原地表加热和云底的潜热释放的日变化显著地影响着地表层位涡的日变化,导致青藏高原的低涡降水系统多在午后至夜间发生发展。证明与传统的青藏高原感热加热指数相比,青藏高原地表层位涡指数能够更好地刻画关于降水的季节变化,与亚洲夏季风降水相关更密切。本文还简单介绍了PVC的概念。指出由于区域边界面的PVC的辐散辐合的变化直接与区域位涡的变化相关联,为保持北半球位涡总量的相对稳定,跨赤道面上的PVC变化与地表PVC的变化必须相互补充,因此跨赤道面上的位涡环流的变化可以成为监测近地表气候变化的窗口。近赤道的海气相互作用能够直接造成沿赤道垂直面上的纬向风垂直切变的变化,激发跨赤道位涡环流异常,从而通过大气内部PVC的变化和青藏高原的调控影响北半球近地表的气候变化。结果表明位涡环流分析为建立热带和热带外大气环流变化的联系开辟了新的蹊径,有着广阔的应用前景。

关键词：位涡源汇位涡环流青藏高原极端天气事件

Assessment of the induced radioactivity in the treatment room of the heavy-ion medical machine in Wuwei using PHITS

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Nuclear Science and Techniques 2023年第2期34卷 153-166页

作者： Ying Luo sheng‑cong Huang Hui Zhang Hai‑Jun Mao Qiang Li Zhong‑Ying Dai Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Science Lanzhou 730000China Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine Lanzhou 730000China Lanzhou University Lanzhou 730000China

Carbon-ion radiotherapy(CIRT)offers unique physical and biological advantages over photon ***,some materials and devices in the CIRT treatment room become radioactive under bombardment by therapeutic carbon-ion beams due to nuclear reactions,thereby leading to possible radiation hazards to medical staff and additional and unwanted doses to *** study assessed the level of induced radioactivity in the treatment room of the Heavy-Ion Medical Machine(HIMM)in *** Carlo simulations using PHITS were performed for a conservative case under the conditions of maximum beam energy and intensity provided by the HIMM *** geometry and configuration of Treatment Room 2 of the HIMM facility in Wuwei were *** evaluated the activation of air,the phantom,and the components of the beamline,such as the primary collimator(PC),ridge filter(RF),and multileaf collimator(MLC).For air activation,we calculated the medical staff immersion external exposure and inhalation internal exposure caused by the corresponding *** phantom activation,we estimated the additional dose to the patient’s family members owing to secondary photons after *** addition,the exemption or non-exemption of the component material activation was *** results showed that external radiation caused by air activation was the main source of the annual effective dose at approximately 0.5 mSv/*** induced radioactivity exposure to family members of a patient after CIRT was approximately 40μSv,sufficiently lower than the public dose limit of 1 mSv/*** induced radioactivity of the PC,RF,and MLC was all above the exempt levels after the devices were retired,whereas the induced radioactivity of the RS and compensator could reach the exempt levels after one patient *** study indicated that medical staff engaged in CIRT should stay away from the high-dose-rate area of induced radioactivity along the beam direction,shorten the residence time in

关键词： activation approximate thereby

Effect of Co on Microstructure and Interfacial Properties of Fe-Based Laser Cladding

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Journal of Iron and Steel Research International 2009年第4期16卷 84-88页

作者： GAO Li-li bian Xiu-fang TIAN Yong-sheng FU Chun-xia Key Laboratory of Liquid Structure and Heredity of Materials of Ministry of Education Shandong University Jinan 250061 Shandong China

The coatings consisting of Fe0. 64 Ni0.36 dendrites as matrix and （Fe, Cr） 7 （C, B） 3 interdendritic compounds as reinforcement were fabricated on the medium steel substrate by laser cladding using the Fe-based powders with different Co content, and Co is uniformly dissolved in the coatings. Compared with the coatings containing 1 % and 5% Co, the coating containing 3 % Co increases in the area fraction of the interdendritic region by about 5 %, in the microhardness nearby the interface by about HV 55 and in the interracial bond strength by about 30 MPa. The interface fracture morphology exhibits the tear appearance, which can be characterized as the ductile fracture.

关键词： laser cladding microstructure microhardness bond strength fracture

Single-atom catalysts based on two-dimensional metalloporphyrin monolayers for ammonia synthesis under ambient conditions

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Nano Research 2022年第5期15卷 4039-4047页

作者： Chun-Xiang Huang sheng-Yao Lv cong Li Bin Peng Guoliang Li Li-Ming Yang Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica Key Laboratory of Material Chemistry for Energy Conversion and StorageMinistry of EducationHubei Key Laboratory of Materials Chemistry and Service FailureHubei Engineering Research Center for Biomaterials and Medical Protective MaterialsSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China Key Laboratory of Theoretical Chemistry of Environment Ministry of EducationCenter for Computational Quantum ChemistrySchool of ChemistrySouth China Normal UniversityGuangzhou 510006China

We systematically investigated the catalytic performance of 3d,4d,and 5d transition metals anchored onto two-dimensional extended porphyrin(PP)substrates as nitrogen reduction reaction(NRR)electrocatalysts,employing density functional theory(DFT)calculations and four-step high-throughput *** novel metalloporphyrin(MPP,M=Zr,Nb,Hf,and Re)single-atom catalyst candidates have been identified due to their excellent catalytic performance(low onset potential,high stability,and selectivity).Through comprehensive reaction path search,the maximum Gibbs free energy changes for NRR on the ZrPP(enzymatic-consecutive hybrid path),NbPP(consecutive path),HfPP(enzymatic-consecutive hybrid path),and RePP(distal path)catalysts are 0.38,0.41,0.53,and 0.53 eV,*** structures,projected density of states,and charge/spin distributions show that the high catalytic activity is due to significant orbital hybridizations and charge transfer between N_(2) and MPP *** hope our work will promote experimental synthesis of these NRR electrocatalysts and provide new opportunities to the electrochemical conversion of N_(2) to NH_(3) under ambient conditions.

关键词： electrocatalytic nitrogen reduction reaction two-dimensional(2D)extended metalloporphyrin(MPP)monolayer singleatom catalyst two-dimensional materials high-throughput screening first-principles calculations

Monte Carlo study of the neutron ambient dose equivalent at the heavy ion medical machine in Wuwei

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Nuclear Science and Techniques 2022年第9期33卷 111-125页

作者： sheng-cong Huang Hui Zhang Kai Bai Ying Luo Hai-Jun Mao Zhong-Ying Dai University of Chinese Academy of Sciences Beijing 100049China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

The use of carbon-ion radiotherapy(CIRT)is gradually *** to the generation of high-energy secondary neutrons during CIRT,its use presents new challenges in radiation ***,secondary neutron dose distributions must be explored and evaluated under clinical scenarios based on different treatment ***,neutron dose and energy spectrum measurements are often *** can be primarily attributed to the inherent limitations of most neutron detectors,such as their unsuitability for spectral measurements and inaccurate responses to neutrons with energies above 20 *** calculation methods based on probabilistic statistical theory are fast and convenient for neutron dose *** this study,external secondary neutron doses at the heavy ion medical machine in Wuwei,which is equipped with a passive beam delivery system,were calculated using the Monte Carlo *** dependence of neutron doses on various treatment parameters(incident carbon-ion beam energy,spatial location,field size,and spread-out Bragg peak(SOBP)width)was ***,the feasibility of applying an analytical model to predict the ambient dose equivalent was *** the combination involving an energy of 400 MeV=u and SOBP width of 6 cm,the ambient dose equivalent per therapeutic dose(H=D)at the isocenter was 79.87 mSv=Gy:The H=D value decreased rapidly with increasing spatial distance and slightly with increasing aperture size and SOBP *** H=D values derived from the Monte Carlo simulations were in good agreement with the results reported in the *** analytical model could be used to quickly predict the H=D value along the incidence direction of the beam with an error of less than 20%.Thus,our study contributes to the understanding of the relationship between neutron radiation and treatment configuration parameters,which establishes a basis for predicting non-therapeutic radiation doses in CIRT.

关键词： Carbon-ion radiotherapy Passive beam delivery Secondary neutrons Monte Carlo method

脓毒症并发急性肾损伤患儿血清中miR-93-5p和miR-424-5p的表达及临床意义

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海南医学 2024年第4期35卷 531-536页

作者：马静郑喜胜李长力赵聪源南阳市中心医院综合ICU 河南南阳473000

目的探讨血清中微小RNA-93-5p(miR-93-5p)和微小RNA-424-5p(miR-424-5p)在脓毒症并发急性肾损伤(S-AKI)患儿中的表达水平及其临床意义。方法选取2019年11月至2021年11月南阳市中心医院综合ICU收治的116例脓毒症患儿作为研究对象,根据脓... 详细信息

目的探讨血清中微小RNA-93-5p(miR-93-5p)和微小RNA-424-5p(miR-424-5p)在脓毒症并发急性肾损伤(S-AKI)患儿中的表达水平及其临床意义。方法选取2019年11月至2021年11月南阳市中心医院综合ICU收治的116例脓毒症患儿作为研究对象,根据脓毒症患儿是否并发AKI分为AKI组60例和非AKI组56例;比较两组患儿的一般资料和血清miR-93-5p、miR-424-5p及肾功能指标[血肌酐(Scr)、胱抑素C(Cys-C)]水平;采用Pearson法分析S-AKI患儿血清miR-93-5p、miR-424-5p与肾功能指标的相关性;采用多因素Logistic回归分析脓毒症患儿并发AKI的影响因素;采用受试者工作特征曲线(ROC)分析血清miR-93-5p、miR-424-5p水平对脓毒症患儿并发AKI的诊断价值。结果AKI组患儿的尿量为(1.52±0.31)mL·kg^(-1)·h^(-1)、血清miR-93-5p表达水平为0.62±0.14,均明显低于非AKI组的(1.87±0.36)mL·kg^(-1)·h^(-1)、(1.02±0.21),急性生理学与慢性健康状况评分(APACHEⅡ评分)、序贯器官衰竭评分(SOFA评分)、血清miR-424-5p表达水平、Scr、Cys-C水平分别为(17.35±5.01)分、(5.77±1.80)分、(2.36±0.51)、(182.84±43.31)μmol/L、(1.63±0.39)mg/L,明显高于非AKI组的(14.96±4.12)分、(5.10±1.41)分、(1.01±0.23)、(91.51±28.34)μmol/L、(0.96±0.28)mg/L,差异均有统计学意义(P<0.05);经Pearson法分析结果显示,S-AKI患儿血清miR-93-5p与Scr、Cys-C呈负相关(r=-0.621、-0.720,P<0.05),miR-424-5p与Scr、Cys-C呈正相关(r=0.503、0.538,P<0.05);经多因素Logistic回归分析结果显示,miR-424-5p、Scr、Cys-C是影响脓毒症患儿并发AKI的危险因素,miR-93-5p是保护因素(P<0.05);经ROC分析结果显示,血清miR-93-5p、miR-424-5p以及两者联合诊断脓毒血症患儿并发AKI的AUC分别为0.856、0.860、0.949,联合诊断的敏感度为90.00%,特异性为91.07%,两者联合优于血清miR-93-5p、miR-424-5p各自单独诊断(Z两者联合-miR-93-5p=2.897、Z两者联合-miR-424-5p=2.706,P=0.004、P=0.007)。结论S-AKI患儿血清miR-93-5p水平显著下调,miR-424-5p水平显著上调,两者联合诊断脓毒血症患儿并发AKI具有更高价值。

关键词：脓毒症急性肾损伤微小RNA-93-5p 微小RNA-424-5p 临床意义

Reduction kinetics of iron oxide pellets with H_2 and CO mixtures

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International Journal of Minerals,Metallurgy and Materials 2015年第7期22卷 688-696页

作者： Hai-bin Zuo cong Wang Jie-ji Dong Ke-xin Jiao Run-sheng Xu State Key Laboratory of Advanced Metallurgy University of Science and Technology of Beijing School of Metallurgical and Ecological Engineering University of Science and Technology of Beijing

Reduction of hematite pellets using H2-CO mixtures with a wide range of H2/CO by molar （1：0, 3：1, 1：1, 1：3, and 0：1） at different reducing temperatures （1073, 1173, and 1273 K） was conducted in a program reducing furnace. Based on an unreacted core model, the effective diffusion coefficient and reaction rate constant in several cases were determined, and then the rate-control step and transition were analyzed. In the results, the effective diffusion coefficient and reaction rate constant increase with the rise in temperature or hydrogen content. Reduction of iron oxide pellets using an H2-CO mixture is a compound control system; the reaction rate is dominated by chemical reaction at the very beginning, competition during the reduction process subsequently, and internal gas diffusion at the end. At low hydrogen content, increasing temperature takes the transition point of the rate-control step to a high reduction degree, but at high hydrogen content, the effect of temperature on the transition point weakens.

关键词： iron oxide pellets reduction kinetics kinetics models hydrogen carbon monoxide

基于微生物组学研究枸杞叶对来曲唑诱导PCOS小鼠的干预作用

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药学学报 2024年第7期59卷 2030-2040页

作者：张莘悦陆聪郑慧丽宿树兰朱悦郭盛钱大玮康宏杰段金廒南京中医药大学江苏省中药资源产业化过程协同创新中心中药资源产业化与方剂创新药物国家地方联合工程研究中心国家中医药管理局中药资源循环利用重点研究室江苏南京210023 宁夏枸杞创新中心宁夏银川750002

本研究旨在探讨枸杞叶对来曲唑诱导的多囊卵巢综合征(polycystic ovary syndrome,PCOS)小鼠的干预作用及其机制。采用来曲唑联合高脂饮食制备PCOS模型,造模成功后将40只小鼠随机分为PCOS组、阳性药二甲双胍组、枸杞叶低剂量组和枸杞叶... 详细信息

本研究旨在探讨枸杞叶对来曲唑诱导的多囊卵巢综合征(polycystic ovary syndrome,PCOS)小鼠的干预作用及其机制。采用来曲唑联合高脂饮食制备PCOS模型,造模成功后将40只小鼠随机分为PCOS组、阳性药二甲双胍组、枸杞叶低剂量组和枸杞叶高剂量组,灌胃给予相应药物,持续29天。实验结束摘眼球取血并收集卵巢组织,检测各组小鼠卵巢质量、空腹血糖(FBG)、空腹胰岛素(FINS)、睾酮(T)、抗苗勒管激素(AMH)、促黄体生成素(LH)、促卵泡刺激素(FSH)、雌二醇(E_(2))水平。采用苏木精-伊红染色观察卵巢组织形态,并计数卵母细胞、囊性卵泡和黄体。采集小鼠盲肠内容物进行肠道菌群组成和差异菌群等分析。动物实验过程经南京中医药大学动物伦理委员会审核通过。结果显示,PCOS小鼠动情周期紊乱。与PCOS组相比,枸杞叶组能明显减轻小鼠卵巢损伤,减少囊状扩张卵泡数,使动情周期正常化。经枸杞叶干预后的FBG、FINS、T、AMH、LH、FSH、LH/FSH水平显著降低(P<0.05),而E_(2)水平显著升高(P<0.001)。此外,枸杞叶能调节PCOS小鼠肠道菌群多样性紊乱,提高拟杆菌门丰度,降低厚壁菌门、回肠杆菌属、罗姆布茨菌属、类杆菌属的丰度。综上,枸杞叶可通过改善胰岛素抵抗、调节生殖激素紊乱及肠道菌群失调而发挥对PCOS小鼠的治疗作用,为枸杞叶的合理利用及开发提供了科学依据和有益参考。

关键词：多囊卵巢综合征枸杞叶胰岛素抵抗肠道菌群干预作用

基于代谢组学的枸杞叶改善D-半乳糖诱导白内障大鼠的生物效应与机制研究

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药学学报 2024年第9期59卷 2594-2605页

作者：陆聪宿树兰朱悦郭盛钱大玮康宏杰郭兰萍段金廒南京中医药大学江苏省中药资源产业化过程协同创新中心中药资源产业化与方剂创新药物国家地方联合工程中心国家中医药管理局中药资源循环利用重点研究室江苏南京210023 宁夏枸杞创新中心宁夏银川750002 中国中医科学院中药资源中心北京100700

评价枸杞叶提取物对白内障大鼠的干预作用及对血浆和肝脏代谢物的影响,探究枸杞叶明目的科学内涵。所有动物实验经南京中医药大学实验动物伦理委员会批准(批准号:202306A067)。采用D-半乳糖(D-gal)诱导的白内障大鼠模型,通过分析晶状体... 详细信息

评价枸杞叶提取物对白内障大鼠的干预作用及对血浆和肝脏代谢物的影响,探究枸杞叶明目的科学内涵。所有动物实验经南京中医药大学实验动物伦理委员会批准(批准号:202306A067)。采用D-半乳糖(D-gal)诱导的白内障大鼠模型,通过分析晶状体混浊程度、晶状体及肝脏组织病理形态改变、晶状体氧化应激水平及多元醇代谢调控水平变化、血清及肝脏氧化水平、肝功能水平及肿瘤坏死因子-α (tumor necrosis factor-α,TNF-α)、白细胞介素-6(interleukin-6,IL-6)等炎症因子含量变化,评价枸杞叶提取物改善大鼠白内障的生物效应。运用UPLC-QTOF-MS/MS技术对大鼠血浆和肝脏组织代谢物进行分析,通过主成分分析(PCA)、正交偏最小二乘法判别分析(OPLS-DA)对比空白组与模型组的代谢数据,筛选潜在的生物标志物,并通过KEGG数据库分析相关代谢通路。结果表明,枸杞叶提取物干预白内障大鼠后其晶状体及肝脏病理状态好转;晶状体中醛糖还原酶(aldose reductase,AR)及Ca^(2+)含量显著降低,山梨醇脱氢酶(sorbitol dehydrogenase,SDH)、GSH含量及CAT活力显著提升;肝脏及血清中GSH含量及SOD活力明显提升,MDA含量、ALT及AST活力及各炎症因子水平显著降低;代谢组学分析结果显示,鉴定出血浆及肝脏组织中15种生物标志物,其中枸杞叶提取物回调视黄酯、硬脂酸和棕榈酸等9种生物标志物。代谢通路富集发现,枸杞叶提取物主要调控视黄醇代谢通路。综上,枸杞叶能有效缓解白内障病理改变,抑制炎症反应,提高抗氧化能力等,其作用机制可能与调控视黄醇代谢通路密切相关,为枸杞叶明目功效科学内涵的揭示提供了科学依据和支撑。

关键词：枸杞叶白内障药效评价代谢组学晶状体肝脏血浆

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