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Pyridapeptides F–I,cyclohexapeptides from marine sponge-derived Streptomyces ***-4539

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Chinese Chemical Letters 2024年第7期35卷 341-344页

作者： Shuige Zhao Pengcheng Yan Peipei liu haishan liu Ning Li Peng Fu Weiming Zhu Key Laboratory of Marine Drugs Ministry of Education of ChinaSchool of Medicine and PharmacyOcean University of ChinaQingdao 266003China Key Laboratory for Marine Drugs and Bioproducts Laoshan LaboratoryQingdao 266237China School of Biological Science and Technology University of JinanJi'nan 250022China Key Laboratory for Biosensors of Shandong Province Biology InstituteQilu University of TechnologyJi'nan 250103China

Four new cyclohexapeptides,pyridapeptides F–I(1–4),were isolated from the fermentation broth of marine sponge-derived Streptomyces *** pyridapeptides F–H(1–3)are composed ofβ-hydroxyleucine,alanine,O-methylthreonine,hexahydropyridazine-3-carboxylic acid,5-hydroxytetrahydropyridazine-3-carboxylic acid,and(2S,3R,4E,6E)-2-amino-3–hydroxy-4,6-dienoic acid *** I(4)contains(2S,3R,4E,6E)-2-amino-3–hydroxy-8-methylnona-4,6-dienoic acid residue and a very rare glycose residue,*** structures were determined based on spectroscopic analysis and chemical *** G–I(2–4)have the 2,3,6-trideoxyhexose units glycosylated at theγ-OH-TPDA residue,displayed significant antiproliferative activity against four(PC9,MKN45,Hep G2,K562)or two(PC9,MKN45)human cancer cell lines.

关键词： Marine microorganism Streptomyces Cyclopeptide glycosides Pyridapeptides Antiproliferative activity

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论苏时学的校勘活动

河池学院学报 2024年第3期44卷 115-120页

作者：陈丕武刘海珊桂林电子科技大学外国语学院广西桂林541004 桂林电子科技大学党委巡察工作办公室广西桂林541004

清代学者苏时学在校勘方面颇有成就,他指出古书的讹、脱、倒、衍等问题。他还指出古书讹误的原因主要是传抄引起的,如形近而误、音近而误、附注抄成正文以及错简脱简等。苏时学的校书方法有对校法、本校法、他校法以及理校法四种。他以... 详细信息

清代学者苏时学在校勘方面颇有成就,他指出古书的讹、脱、倒、衍等问题。他还指出古书讹误的原因主要是传抄引起的,如形近而误、音近而误、附注抄成正文以及错简脱简等。苏时学的校书方法有对校法、本校法、他校法以及理校法四种。他以此四法校书,取得了巨大的成就,也值得借鉴。

关键词：苏时学校勘文献

Characterizing extreme drought and wetness in Guangdong,China using global navigation satellite system and precipitation data

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Satellite Navigation 2024年第1期5卷 258-274页

作者： Hai Zhu Kejie Chen haishan Chai Yuanbin Ye Wenjian liu Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen518055China Lands and Resource Department of Guangdong Province Surveying and Mapping InstituteGuangzhou510500China

As global temperature rises,the frequency of extreme climate events,e.g.,severe droughts and floods,has increased significantly and caused severe damage over the past *** this regard,precipitation efficiency,a crucial meteorological parameter,could provide valuable insights for a better understanding of the patterns and characteristics of these extreme *** this study,taking Guangdong province as an exemplary region,we first obtained long-term and high-resolution historical records of precipitation efficiency by integrating the observations from a dense network of Global Navigation Satellite System(GNSS)stations with precipitation data,and then characterized the extreme drought and wetness through climate *** found a distinct seasonal trend in precipitation efficiency in Guangdong,with annual fluctuations ranging from 10 to 25%.Notably,precipitation efficiency is higher in proximity to the Pearl River Delta Plain and gradually decreases towards the east and *** occurrence of anomalous peaks and valleys in precipitation efficiency generally corresponds to dry and wet conditions,respectively.A total of 9 extreme wet events and 6 dry events occurred from January 2007 to May 2022,with durations from 3 to 6 *** results also demonstrated that both wet and dry frequencies exhibit an increasing trend with the expansion of the time scale,and the frequency of extreme events near the Pearl River Delta Plain surpasses that of other ***,the propagation time from meteorological anomalies to agricultural and hydrological anomalies is about 3 *** periodic characteristics of meteorological anomalies are identified as the primary driver for other anomalous periodic *** work unveils the long-term dynamic behavior of precipitation efficiency,as well as the characteristics of extreme drought and wetness events in the regions characterized by intricate land–atmosphere interactions.

关键词： GNSS Precipitation efficiency Extreme drought and wetness

Differences in Variations of Long-Lived and Short-Lived Summer Heat Waves during 1981-2020 over Eastern China and Their Corresponding Large-Scale Circulation Anomalies

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Journal of Meteorological Research 2024年第3期38卷 414-436页

作者： Liqun JI haishan CHEN Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of EducationNanjing University of Information Science&TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing210044China

Using daily maximum temperature(Tmax)data from 516 observation stations in eastern China from 1981 to 2020,this study employed a relative threshold method to define short-and long-lived heat waves(HWs)by considering regional climate differences to investigate the spatial characteristics and evolution of large-scale circulation during summer *** results demonstrated spatial disparities in the frequency distribution of HWs of different durations and differences in the magnitude of duration and intensity between short-and long-lived *** orthogonal function analysis revealed three dominant spatial modes for both short-and long-lived *** first mode showed that short-lived HWs occur prominently in both northern and southern regions,whereas long-lived HWs mainly occur in the northern *** second mode was characterized by a meridional dipole pattern in both *** third mode exhibited a quadrupole pattern for short-lived HWs and a tripole pattern for long-lived *** in the center locations of anomalies in the 500-hPa geopotential height and 850-hPa wind fields significantly influenced the temperature and precipitation anomaly distribution of typical HWs by affecting the warm column in the lower troposphere,cloud distribution,and moisture ***,the atmospheric circulation evolution processes of typical HWs associated with the different modes of long-and short-lived HWs were linked to distinct teleconnection *** the three modes of long-lived(short-lived)HWs,there was stronger(weaker)wave flux activity with multiple(single)propagation *** westward Atlantic wave train activity at 300 hPa triggered the synergistic action of meridional and zonal wave fluxes,favoring the strengthening and maintenance of positive anomalies in geopotential height of 500 *** may have contributed to the formation of long-lived *** findings provide valuable insights to enhance our understanding and prediction of summer

关键词： short-lived heat waves(HWs) long-lived HWs empirical orthogonal function(EOF)modes large-scale atmospheric circulation

Impacts of Roof/Ground Mitigation Strategies on Improving the Urban Thermal Environment and Human Comfort over the Yangtze River Delta, China

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Journal of Meteorological Research 2024年第1期38卷 108-125页

作者： Hongyun MA Mi ZHANG haishan CHEN Yan WANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric Sciences Nanjing UniversityNanjing 210023 Experimental Teaching Center for Meteorology and Environment Nanjing University of Information Science&TechnologyNanjing 210044

The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal environment. In this study, the Weather Research and Forecasting Model(WRF), coupled with a single-layer Urban Canopy Model(UCM), was used to study the impact of heat mitigation strategies. In addition, a 5-km resolution land-cover dataset for China(ChinaLC), which is based on satellite remote sensing data, was adjusted and used, and 18 groups of numerical experiments were designed, to increase the albedo and vegetation fraction of roof/ground parameters. The experiments were conducted for four heatwave events that occurred in the summer of 2013 in the Yangtze River Delta urban agglomeration of China. The simulated results demonstrated that, for the single roof/ground schemes, the mitigation effects were directly proportional to the albedo and greening. Among all the experimental schemes, the superposed schemes presented better cooling effects. For the ground greening scheme, with similar net radiation flux and latent heat flux, its storage heat was lower than that of the roof greening scheme, resulting in more energy flux into the atmosphere, and its daytime cooling effect was not as good as that of the roof greening scheme. In terms of human thermal comfort(HTC), the improvement achieved by the ground greening scheme was better than any other single roof/ground schemes, because the increase in the relative humidity was small. The comprehensive evaluation of the mitigation effects of different schemes on the thermal environment presented in this paper provides a theoretical basis for improving the urban environment through rational urban planning and construction.

关键词： urban heat island human thermal comfort urban canopy mitigation strategies Yangtze River Delta Weather Research and Forecasting Model(WRF) Urban Canopy Model(UCM)

Synergistic Impacts of Indian Ocean SST and Indo-China Peninsula Soil Moisture on the 2020 Record-breaking Mei-yu

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Advances in Atmospheric Sciences 2024年第9期41卷 1735-1750页

作者： Yinshuo DONG haishan CHEN Xuan DONG Wenjian HUA Wenjun ZHANG Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China Bureau of Hydrology ChangJiang Water Resources CommissionWuhan 430010China

The Yangtze River basin(YRB)experienced a record-breaking mei-yu season in June‒July *** unique long-lasting extreme event and its origin have attracted considerable *** studies have suggested that the Indian Ocean(IO)SST forcing and soil moisture anomaly over the Indochina Peninsula(ICP)were responsible for this unexpected ***,the relative contributions of IO SST and ICP soil moisture to the 2020 mei-yu rainfall event,especially their linkage with atmospheric circulation changes,remain *** using observations and numerical simulations,this study examines the synergistic impacts of IO SST and ICP soil moisture on the extreme mei-yu in *** show that the prolonged dry soil moisture led to a warmer surface over the ICP in May under strong IO SST *** intensification of the warm condition further magnified the land thermal effects,which in turn facilitated the westward extension of the western North Pacific subtropical high(WNPSH)in June‒*** intensified WNPSH amplified the water vapor convergence and ascending motion over the YRB,thereby contributing to the 2020 *** contrast,the land thermal anomalies diminish during normal IO SST backgrounds due to the limited persistence of soil *** roles of IO SST and ICP soil moisture are verified and quantified using the Community Earth System *** synergistic impacts yield a notable 32%increase in YRB *** findings provide evidence for the combined influences of IO SST forcing and ICP soil moisture variability on the occurrence of the 2020 super mei-yu.

关键词： super mei-yu Indian Ocean SST soil moisture Indochina Peninsula

Insight into the mechanism of 5-hydroxymethylfurfural electroreduction to 2,5-bis(hydroxymethyl)furan over Cu anchored N-doped carbon nanosheets

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Nano Research 2024年第9期17卷 7991-7999页

作者： Haoran Wu Xinwei Chen haishan Xu Runlu Yang Xin Wang Junying Chen Zhenbing Xie Liang Wu Yiyong Mai School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgeingShanghai Jiao Tong UniversityShanghai 200240China Department of Chemistry Tangshan Normal UniversityTangshan 063000China

Design of non-noble metal electrocatalysts for biomass conversion to high-value chemicals and understanding the related catalytic mechanisms are of profound significance but have remained a major ***,we developed a novel biomass-derived electrocatalyst(denoted as Cu/NC),featuring with electron-deficient copper nanoparticles anchored on N-doped carbon nanosheets,for the electrochemical reduction of 5-hydroxymethylfurfural(HMF)to 2,5-bis(hydroxymethyl)furan(BHMF,a vital precursor of functional polymers).The optimized Cu/NC electrocatalyst exhibited an excellent performance with high Faradaic efficiency(89.5%)and selectivity(90.8%)of BHMF at a low concentration of HMF(18.1 mM).Even at a very high HMF concentration(108.6 mM),the Faraday efficiency and selectivity of BHMF could still reach 74.8%and 81.1%,*** performance approached those of the reported noble metal-based *** study revealed that the N doping in the Cu/NC catalyst could regulate the electronic structure of Cu,strengthening the adsorption of the HMF carbonyl group,and thus boosting the selectivity of ***,strong electronic metal-support interactions of Cu and the N-doped carbon support optimized the charge transfer rate,thus promoting the dissociation of water to the active hydrogen(H^(*))species and boosting the reaction kinetic rate of H^(*)and HMF.

关键词： biomass 5-hydroxymethylfurfural electrochemical reduction N-doped carbon materials 2,5-bis(hydroxymethyl)furan

Pressure stimulated current in progressive failure process of combined coal-rock under uniaxial compression:Response and mechanism

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International Journal of Mining Science and Technology 2024年第2期34卷 227-243页

作者： Tiancheng Shan Zhonghui Li Xin Zhang haishan Jia Xiaoran Wang Enyuan Wang Yue Niu Dong Chen Weichen Sun Dongming Wang State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou 221116China National Engineering Research Center for Coal Gas Control China University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground *** reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength *** mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is *** influence of strength combinations on PSCs in the progressive failure process are *** results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical *** the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture *** PSC flow model is initially validated by the relationship between the accumulated charges of different *** results are expected to provide a new reference and method for mining design and roadway quality assessment.

关键词： Combined coal-rock Pressure stimulated current Progressive failure process Mechanism Flow model

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分两阶段变换坐标的点云粗配准算法

激光与光电子学进展 2022年第16期59卷 117-124页

作者：李思远刘瑾杨海马刘海珊上海工程技术大学电子电气工程学院上海201620 上海理工大学光电信息与计算机工程学院上海200093

针对传统点云配准方法效率低、误差大的问题,提出了一种沿竖直方向和水平方向分阶段变换的点云粗配准方法。首先对点云P、Q进行去中心化处理,使得两点云中心点重合;通过遍历距质心的距离寻找特征点,并将特征点旋转至y轴上,完成竖直方向... 详细信息

针对传统点云配准方法效率低、误差大的问题,提出了一种沿竖直方向和水平方向分阶段变换的点云粗配准方法。首先对点云P、Q进行去中心化处理,使得两点云中心点重合;通过遍历距质心的距离寻找特征点,并将特征点旋转至y轴上,完成竖直方向上的对齐;然后在xOz平面内,再次通过遍历距质心的距离寻找特征点,将其绕y轴旋转,在水平方向完成对齐;最后配合迭代最近点精配准算法完成配准。所提方法不存在迭代计算,具有线性时间复杂度和常数空间复杂度。对所提方法与三种经典方法进行对比实验,采用了点数量不同以及尺度不同的三组点云。实验结果表明,对于不同的点云,所提方法具有较强的鲁棒性,配准时间在4 s左右,变化幅度较小,相对于三种传统方法,耗时减少了50%以上;同时所提方法的均方根误差控制在10mm左右,保持了较好的精度。

关键词：图像处理点云配准分阶段迭代最近点三维重构