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Rapid Quantitative Determination of Isoprene Monomer in Living Taraxacum kok-saghyz by Ultra-High Performance Liquid Chromatography Tandem mass Spectrometry

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China Petroleum Processing & Petrochemical Technology 2020年第2期22卷 30-36页

作者： Xiang Tong Guo Tianyang Zhang Xi Chen Yunhan Dong Yiyang Zhang Jichuan ma qiang Zhang Liqun Center of Advanced Elastomer materials College of Materials and EngineeringBeijing University of Chemical TechnologyBeijing 100029 College of Life Science and Technology Beijing University of Chemical TechnologyBeijing 100029 School of Food and Health Beijing Technology and Business UniversityBeijing 100048 Institute of Industrial and Consumer Product Safety Chinese Academy of Inspection and QuarantineBeijing 100176

Taraxacum kok-saghyz(TKS)is rich in natural rubber(NR),a natural organic macromolecular compound composed of cis-1,4-polyisoprene,and may become the second NR-bearing plant for biochemical engineering *** this paper,a rapid and quantitative ultra-high performance liquid chromatography tandem mass spectrometry(UHPLCMS/MS)method was established for determination of macromolecular biosynthesis substrate(dimethylallyl pyrophosphate,DmaPP)and initiator(farnesyl pyrophosphate,FPP)contained in TKS.A Kromasil C18 chromatographic column was used for separation,and the multi-reaction monitoring mode(MRM)of triple quadrupole mass spectrometry was used for *** was performed by external calibration *** results showed that the limit of detection(LOD)and the limit of quantitation(LOQ)of DmaPP were 2.42μg/L and 7.26μg/L,respectively,and the LOQ and the LOD of FPP were 1.02μg/L and 3.05μg/L,*** a concentration of 1—1000μg/L,both analytes had good determination coefficients(>0.999)of calibration *** recoveries of DmaPP and FPP were between 99.0%and 117.1%.In real samples detection,the contents of DmaPP and FPP in TKS samples were between 23.32—82.77μg/L and 12.03—85.67μg/L,***,this approach is a reliable method to quantify DmaPP and FPP in TKS.

关键词： quantitation Taraxacum kok-saghyz(TKS) isoprenoids ultra-high performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS) natural rubber(NR)

Photocatalytic degradating methyl orange in water phase by UV-irradiated CdS carried by carbon nanotubes

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Science China(Technological Sciences) 2007年第3期50卷 279-289页

作者： LI ChenSha TANG YaPing KANG BoNan WANG BinSong ZHOU Feng ma qiang XIAO Ji WANG DaZhi LIANG Ji Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China New material Division Institute of Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China Department of Chemistry Tsinghua UniversityBeijing 100084China School of Chemistry and materials Science Heilongjiang UniversityHarbin 150080China

A new candidate for photocatalytic degradating organic dyes,CdS carried by car-bon nanotubes(CdS/CNTs) ,is reported. The degradation ratio curves of methyl orange in water phase show that the capability for degradating organic molecules of CdS/CNTs is obviously higher than that of separated CdS. The degradation ca-pability enhances as the increase of the amount of net CdS catalyst,the ratio of carbon nanotubes to CdS,and the area of the template,and is influenced by the pH value and the temperature of aqueous solution. These results suggest that the photocatalyst of CdS/CNTs is very suitable for potential applications in organic waste removal from water.

关键词： carbon nanotube cadmium sulfide methyl orange photocatalysis

Temporal and Spatial Distribution of Lightning Activity in Ulanqab City

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Meteorological and Environmental Research 2023年第1期14卷 60-62页

作者： qiang ma Ulanqab Meteorological Bureau of Inner Mongolia Ulanqab 012000China

From January 2020 to December 2021,Ulanqab Meteorological Bureau of Inner Mongolia used VLF/LF lightning locator to carry out three-dimensional lightning monitoring in Ulanqab City,and compared with ADTD lightning location data in the same *** results show that both VLF/LF lightning locator and ADTD lightning locator had excellent monitoring ability for lightning during flood season in ***/LF lightning locator was slightly superior to ADTD lightning locator in observation accuracy,the observation ability of low-current cloud-to-ground lightning,intracloud lightning observation and so *** were obvious temporal and spatial characteristics of cloud-to-ground lightning during flood season in Ulanqab,and there was a certain correlation between the areas where lightning appeared frequently and surface *** lightning was mainly concentrated at a height of 1-7 *** cloud-to-ground lightning accounted for about 75%of total cloud-to-ground lightning,and negative intracloud lightning accounted for 39%of total intracloud lightning.

关键词： Lightning location Cloud-to-ground lightning Intracloud lightning Temporal and spatial distribution

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质子偶素:实验发现及理论预言

科学通报 2024年第31期69卷 4620-4624页

作者：马伯强北京大学物理学院北京100871

2024年4月9日,北京谱仪Ⅲ(Beijing SpectrometerⅢ,BESⅢ)合作组[1]在Physical Review Letter发表了一篇文章,报道了实验组利用北京正负电子对撞机(Beijing Electron Positron Collider,BEPC)产生的100亿个粲夸克偶素事例,分析由粲夸克偶素衰变到一个光子和三对正负介子对的衰变过程,通过重建三对正负介子对的不变质量并由两个共振态结构X(1840)和X(1880)来拟合数据(图1),发现X(1880)的统计显著性超过10倍标准偏差的偏离.

关键词：粲夸克偶素 BESⅢ 不变质量衰变过程理论预言统计显著性标准偏差北京谱仪Ⅲ

Study of latch-up immunization in bulk CMOS integrated circuits exposed to transient ionizing radiation

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Science China(Technological Sciences) 2012年第11期55卷 3242-3247页

作者： LI RuiBin CHEN Wei LIN DongSheng YANG ShanChao BAI XiaoYan WANG GuiZhen LIU Yan QI Chao ma qiang Northwest Institute of Nuclear Technology Xi'an 710024China

This paper presents experimental results of transient gamma irradiation effects on two kinds of *** is a two-stage circuit consisting of a bipolar power device L7805CV and a bulk complementary metal-oxide-semiconductor(CMOS) device IDT6116,the other is a two-stage circuit consisting of a bipolar power device L7805CV and the equivalent circuit of the parasitic P-N-P-N structure in bulk CMOS *** results show that the L7805CV's output interruption after transient irradiation can prevent latch-up from occurring on the second stage *** demanded minimum interruption duration to avoid latch-up varies with dose rate,and this is confirmed by the experimental results.

关键词： transient radiation' latch up dose rate bulk CMOS device

Two new saponins from Anemarrhena asphodeloides Bge.

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Chinese Chemical Letters 2007年第2期18卷 171-174页

作者： Ying Peng Yu Jing Zhang Zhi qiang ma Wei San Pan Yu Qing Sun Shao Jiang Song School of Pharmacy Shenyang Pharmaceutical UniversityShenyang 110016China No.2 Herbal Factory Haerbin Phamarceuticals GroupHaerbin 150078China

Two new saponins 3-O-β-d-glucopyranosyl (1 → 2)-β-d-mannopyranosyl sarsasapogenin, named timosaponin A IV(1) and (5β, 25S)-26-O-β-d-glucopyranosyl-furost-20(22)-en-3,26-diol-3-O-β-d-glucopyranosyl (1 → 4) glucopyranosyl (1 → 2)-β-d-galacopyranoside, named timosaponin B IV(2), were isolated by silica gel column chromatography and preparative HPLC from Anemarrhena asphodeloides Bge. Their structures were elucidated by chemical characters and spectroscopic analysis.

关键词： Anemarrhena asphodeloides Bge. Saponin Timosaponin A IV Timosaponin B IV Structural identification

Identification and distribution of a single nucleotide polymorphism responsible for the catechin content in tea plants

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Horticulture Research 2020年第1期7卷 2395-2403页

作者： Chen-Kai Jiang Jian-qiang ma Yu-Fei Liu Jie-Dan Chen De-Jiang Ni Liang Chen Key Laboratory of Tea Biology and Resources Utilization Ministry of Agriculture and Rural AffairsTea Research Institute of the Chinese Academy of Agricultural Sciences9 South Meiling RoadHangzhouZhejiang 310008China College of Horticulture and Forestry Science Huazhong Agricultural University1 Shizishan StreetHongshan DistrictWuhanHubei 430070China Tea Research Institute Yunnan Academy of Agricultural SciencesMenghaiYunnan 666201China

Catechins are the predominant products in tea plants and have essential functions for both plants and *** genes encoding the enzymes regulating catechin biosynthesis have been identified,and the identification of single nucleotide polymorphisms(SNPs)resulting in nonsynonymous mutations within these genes can be used to establish a functional link to catechin ***,the transcriptomes of two parents and four filial offspring were sequenced using next-generation sequencing technology and aligned to the reference genome to enable SNP ***,176 tea plant accessions were genotyped based on candidate SNPs using kompetitive allelespecific polymerase chain reaction(KASP).The catechin contents of these samples were characterized by highperformance liquid chromatography(HPLC),and analysis of variance(ANOVA)was subsequently performed to determine the relationship between genotypes and catechin *** a result of these efforts,a SNP within the chalcone synthase(CHS)gene was shown to be functionally associated with catechin ***,the geographical and interspecific distribution of this SNP was ***,these results will contribute to the early evaluation of tea plants and serve as a rapid tool for accelerating targeted efforts in tea breeding.

关键词： distribution content mining

^(226)Ra evidence for the ecosystem shift over the past 40 years in the North Pacific Subtropical Gyre

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Chinese Science Bulletin 2007年第6期52卷 832-838页

作者： YANG JunHong CHEN Min QIU YuSheng LI YanPing ma qiang LUE E ZHANG Run HUANG YiPu Department of Oceanography Xiamen University Xiamen 361005 China State Key Laboratory of marine Environmental Science Xiamen University Xiamen 361005 China

Surface seawater was collected for ^(226)Ra measurement in the North Pacific Subtropical Gyre from July to October, 1999 and October to December, 2003. Combined with the historical data reported for this sea area, a declined trend of surface ^(226)Ra concentrations was observed since 1960s, indicating the ecosystem shift in response to global warming. On one side, the enhanced stratification of the upper water column resulting from global warming reduced the ^(226)Ra input from the depth, on the other, the temporal increase of biological production resulting from the climate-related ecosystem structure change strengthened the ^(226)Ra removal from the surface ocean. Both the physical and biological processes resulted in the decrease of surface ^(226)Ra concentrations in the North Pacific Subtropical Gyre. The temporal trend of surface ^(226)Ra concentrations was consistent with the trends of chlorophyll a, silicate, phosphate and primary production previously reported. This study provided ^(226)Ra evidence for the ecosystem shift under global change.

关键词：北太平洋亚热带涡流生态系统漂变镭226 放射性同位素浓度海面海水

Site testing campaign for the Large Optical Telescope at the Ali site

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Research in Astronomy and Astrophysics 2020年第6期20卷 141-150页

作者： Li-Yong Liu Yong-qiang Yao Jia Yin Hong-Shuai Wang Jun-Rong Li Yun-He Zhou Xian-Long You Peng Tang Xi-Yue Zhao De-qiang ma Jian Dong National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The Large Optical/infrared Telescope(LOT)is a ground-based 12 m diameter telescope which is proposed to be built in western *** site selection for LOT in China began in 2016,and Ali was listed as one of the three candidate *** studies and local surveys have been carried out for more than 15 years in western China,and the results show that Ali is a promising site with comprehensive quality in terms of atmospheric and supporting *** overview of the site testing campaign at the Ali site from 2016 to 2019 is *** the two years of data collection,the overall median seeing value is found to be 1.17 arcsec,the observable nights are 81.71%and the good observable nights are 71.76%.The weather conditions as follows,the median night temperature value is-5.18℃,the median night relative humidity value is 41.25%,the median night atmospheric pressure value is 540.92 hPa,the median night wind speed value is 7.41 m s-1 and the mainly wind direction is southwestern(SW).The median night sky background value is 22.07 *** also discuss the wind speed at different locations on-site,the possibility of light pollution and the effect of wind speed on differential image motion monitor(DIMM)seeing measurements.

关键词： large optical telescope site testing Ali site cloudiness seeing