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Study the Changes in Soil Organic Carbon of Rice-Maize Cropping System in the Top Layer of Alluvisol Soil in Dan Phuong: A Study of C-13 Stable Isotope Composition (<i>&delta;</i><sup>13</sup>C) 被引量:1
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作者 Nguyen Thi Hong Thinh Vu Hoai +4 位作者 Ha Lan Anh Vo Thi Anh Truong Viet Chau Trinh Van Giap Tran Minh Tien 《Journal of Environmental Protection》 2019年第10期1361-1372,共12页
In this study, the experiments on field were conducted to examine the change in the content of soil organic carbon (SOC), its C-13 stable isotope composition (δ 13C) and some main physical, chemical parameters (soil ... In this study, the experiments on field were conducted to examine the change in the content of soil organic carbon (SOC), its C-13 stable isotope composition (δ 13C) and some main physical, chemical parameters (soil moisture, pH, soil density, content of humic, fulvic, total N, total P, total K) in alluvial soil of Dan Phuong region—Vietnam at a depth of 0 - 30 cm when we changed the regime from 2 maize -1 rice crop to 2 rice - 1 maize crop per 1 year. In addition to analyzing the main parameters in soil, C content and its δ 13C value in parts of rice and maize (root, stem and leaf) were also analyzed to assess the contribution of plant residues on soil organic carbon content after harvest. The experiment was carried out in 2016-2017 on the field with the traditional farming method of local farmers along with the tropical monsoon weather conditions of the North-Vietnam. The results showed that SOC had positive correlation with total N, total P parameters and negative correlation with δ 13C values of soil samples at two layers (0 - 15 cm and 15 - 30 cm). The average of total dry biomass (stem, stump + roots and leaf parts) per 1 rice and 1 maize crop was 10.64 Mg/ha and 9.09 Mg/ha, respectively. The average of δ 13C value of rice (C3 plant) was -29.78‰ and its value of maize (C4 plant) was -12.61‰. The new plant (rice) contributes to the total soil organic carbon content from 11.31% to 44.14% at the 0 - 15 cm layer and from 6.55% to 11.31% at the 15 - 30 cm layer in one-year experiment period. 展开更多
关键词 SOIL organic carbon (SOc) c-13 Stable isotope MAIZE and RIcE crop SOIL Properties
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Differential response of radial growth and δ^(13)C in Qinghai spruce(Picea crassifolia) to climate change on the southern and northern slopes of the Qilian Mountains in Northwest China 被引量:1
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作者 Li Qin Huaming Shang +4 位作者 Weiping Liu Yuting Fan Kexiang Liu Tongwen Zhang Ruibo Zhang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期205-218,共14页
Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Q... Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic factors.Tree-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the southern.Tree-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing season.Stomatal conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate did.The response between tree rings and climate in mountains gradually weakened as climate warmed.Changes in radial growth and stable carbon isotope fractionation of P.crassifolia in response to climate in the Qilian Mountains may be further complicated by continued climate change. 展开更多
关键词 Tree rings Qinghai spruce(Picea crassifolia Kom.) Stable carbon isotope(δ^(13)c) Qilian Mountains:climate change
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^(13)C稳定同位素在陆地生态系统植物-微生物-土壤碳循环中的应用
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作者 白雪娟 翟国庆 刘敬泽 《林业科学》 EI CAS CSCD 北大核心 2024年第7期175-190,共16页
绿色植物通过光合作用吸收大气中的CO_(2),是陆地生态系统的主要碳(C)源,量化光合C在植物-土壤系统间的分配,对于明确C的周转与存留、预测气候变化背景下植被和土壤C库潜力具有重要意义。^(13)C稳定同位素技术具有准确性和易操作性,在C... 绿色植物通过光合作用吸收大气中的CO_(2),是陆地生态系统的主要碳(C)源,量化光合C在植物-土壤系统间的分配,对于明确C的周转与存留、预测气候变化背景下植被和土壤C库潜力具有重要意义。^(13)C稳定同位素技术具有准确性和易操作性,在C循环研究中被广泛应用,为探究植物-土壤系统C分配、土壤微生物群落结构、C利用效率和土壤C矿化为CO_(2)通量变化等特性提供重要技术支撑。本研究首先介绍^(13)C稳定同位素的发展和标记方法,主要有^(13)C脉冲(单次与多次)标记、^(13)C连续标记、借助C_(4)土壤种植C_(3)植物确定^(13)C丰度以及不改变植被条件鉴定自然^(13)C丰度等。其次总结该技术在植物-微生物-土壤系统C循环中的应用:主要包括^(13)C同位素标记在植物-土壤系统C分配,^(13)C自然丰度技术在树木生长轮和植物群落水平C循环、土壤有机C形成与分解过程中的应用;在土壤微生物方面,概述^(13)C稳定同位素在磷脂脂肪酸、氨基糖、芯片-稳定同位素探针、纳米二次离子质谱同位素成像、荧光原位杂交-纳米二次离子质谱技术等微生物标志物上的应用。接着总结^(13)C稳定同位素方法的缺点,即^(13)C样品检测价格昂贵、由于^(13)C分馏作用影响^(13)C丰度检测不准确及^(13)C标记与微生物标志物技术结合对^(13)C标记丰度要求较高等。最后,对未来^(13)C同位素示踪技术研究提出展望:在理论上,需探究^(13)C标记底物在植物-土壤-微生物系统C分配、转化和固持的作用机制和影响机制,构建统计与验证模型;在应用上,应注重交叉学科的运用,将地理信息系统、遥感等地学技术与^(13)C稳定同位素相结合,从更广泛、更全面的角度推进陆地生态系统C循环研究。 展开更多
关键词 ^(13)c稳定同位素标记技术 陆地生态系统 碳循环 土壤有机碳 微生物标志物
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Hydrogeochemical and isotopic assessment of the origin of NO_(3)^(−)and N-NH_(3)contents in the aquifer located in a closed lacustrine volcano-sedimentary basin in the metropolitan area of Mexico City
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作者 Jose Ivan Morales-Arredondo Maria Aurora Armienta Hernandez +1 位作者 Joel Edmundo Ortega-Gutierrez Elisa Cuellar Ramirez 《Acta Geochimica》 EI CAS CSCD 2024年第4期719-736,共18页
To explain the presence and spatial distribution of NO_(3)^(−)and N-NH_(3)in the Aquifer of the Metropolitan Area of Mexico City(AMAMC),a hydrogeochemical and isotopic analysis using^(13)C DIC(as well as the stable is... To explain the presence and spatial distribution of NO_(3)^(−)and N-NH_(3)in the Aquifer of the Metropolitan Area of Mexico City(AMAMC),a hydrogeochemical and isotopic analysis using^(13)C DIC(as well as the stable isotopes^(18)O and^(2)H)in groundwater was conducted.This aquifer is located in an old closed lacustrine volcano-sedimentary basin;some wells hosted in the semi-confined zone contain high N-NH_(3)concentrations,while others present NO_(3)^(−)contents in the recharge zones(hosted in an oxidizing environment).In this study,a change in the isotopic signature(primarily in^(18)O and^(2)H)was observed from the recharge zones to the basin center in some of the wells with high NO_(3)^(−)concentrations,this behavior can be attributed to evaporation during the incorporation of recently infiltrated water.In addition,the results for^(13)C(along with ^(2) H)in wells with the highest N-NH_(3)concentrations exhibited an atypically broad range of values.Results indicated the occurrence of hydrogeochemical and/or biochemical processes in the aquifer(in an oxidizing or reducing environment),such as organic degradation,bacterial decomposition(primarily in the ancient Lake Texcoco and which acts as a natural sink for carbon,nitrogen,sulfur,and phosphorus),besides rock weathering and dissolution,which may be responsible for a very marked isotopic modification of the^(13)C(and,to a lesser extent,2 H).Methanotrophic bacterial activity and methanogenic activity may be related to N-NH_(3)removal processes by oxidation and residual water incorporation respectively,whereas the increase in the NO_(3)^(−)content in some wells is due to the recent contribution of poor-quality water due to contamination. 展开更多
关键词 18 O and^(13)c isotopes Iron Hydrogeochemical processes NITRATE Nitrogen species
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Isotopes (<sup>13</sup>C and <sup>18</sup>O) Geochemistry of Lower Triassic Montney Formation, Northeastern British Columbia, Western Canada
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作者 Edwin I. Egbobawaye 《Natural Science》 2017年第10期355-376,共22页
Oxygen isotope (δ18O) serves as paleothermometer, and provides paleotemperature for carbonates. δ18O signature was used to estimate the temperature of fractionation of dolomite and calcite in Montney Formation, empi... Oxygen isotope (δ18O) serves as paleothermometer, and provides paleotemperature for carbonates. δ18O signature was used to estimate the temperature of fractionation of dolomite and calcite in Montney Formation, empirically calculated to have precipitated, between approximately 13°C to ±33°C during Triassic time in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Measurements of stable isotopes (δ13C and δ18O) fractionation, supported by quantitative X-ray diffraction evidence, and whole-rock geochemical characterization of the Triassic Montney Formation indicates the presence of calcite, dolomite, magnesium, carbon and other elements. Results from isotopic signature obtained from bulk calcite and bulk dolomite from this study indicates depleted δ13CPDB (-2.18‰ to -8.46‰) and depleted δ18OPDB (-3.54‰ to -16.15‰), which is interpreted in relation to oxidation of organic matter during diagenesis. Diagenetic modification of dolomitized very fine-grained, silty-sandstone of the Montney Formation may have occurred in stages of progressive oxidation and reduction reactions involving chemical elements such as Fe, which manifest in mineral form as pyrite, particularly, during early burial diagenesis. Such mineralogical changes evident in this study from petrography and SEM, includes cementation, authigenic quartz overgrowth and mineral replacement involving calcite and dolomite, which are typical of diagenesis. High concentration of chemical elements in the Montney Formation?-Ca and Mg indicates dolomitization. It is interpreted herein, that calcite may have been precipitated into the interstitial pore space of the intergranular matrix of very fine-grained silty-sandstone of the Montney Formation as cement by a complex mechanism resulting in the interlocking of grains. 展开更多
关键词 isotopeS Stable isotopeS 13c and 18O isotope GEOcHEMISTRY Montney FORMATION GEOcHEMISTRY chemical Element Mineralogy Tight Gas Reservoir BRITISH cOLUMBIA Western canada Sedimentary Basin (WcSB) Triassic Subsurface Geology
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土壤呼吸及其^(13)C同位素测定方法的对比研究 被引量:1
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作者 聂棠棠 王娟 +1 位作者 姚槐应 葛超荣 《土壤》 CAS CSCD 北大核心 2023年第3期578-586,共9页
为比较不同方法在土壤呼吸及其^(13)C同位素测定中的差异,应用气相色谱仪法(GC-TCD)、稳定同位素比值质谱仪气体进样法(Gasbench-IRMS)、甲酚红显色法(MicroResp)、碱液吸收法4种方法测定土壤呼吸速率,并采用Gasbench-IRMS法和碱液吸收... 为比较不同方法在土壤呼吸及其^(13)C同位素测定中的差异,应用气相色谱仪法(GC-TCD)、稳定同位素比值质谱仪气体进样法(Gasbench-IRMS)、甲酚红显色法(MicroResp)、碱液吸收法4种方法测定土壤呼吸速率,并采用Gasbench-IRMS法和碱液吸收法两种方式检测土壤呼吸的^(13)C同位素丰度,以期准确评估土壤呼吸及碳排放,并为相关研究提供参考。结果表明:(1)两种仪器法(GC、IRMS)测定土壤呼吸速率的数值结果相近(基础呼吸)或趋势一致(诱导呼吸),且重复性好(标准偏差分别为0.011、0.010mg/(kg·h)),准确度高;MicroResp法的测定结果与仪器测量值较为相近,但分辨率较低;碱液吸收法的测定结果较真实值偏高(当土壤有机质含量低时)或偏低(当土壤有机质含量高时)。(2)在测定CO_(2)中的^(13)C含量上,Gasbench-IRMS法直接测定的结果误差小(δ^(13)C值的标准偏差为0.137‰),接近实际值,可以准确地反映出土壤微生物呼吸对底物的利用状况。综上,仪器法较化学分析法(MicroResp、碱液吸收)更能准确测定土壤呼吸及其^(13)C同位素。 展开更多
关键词 土壤呼吸测定 ^(13)c同位素丰度 方法比较
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^(13)C示踪技术在利玛原甲藻中腹泻性贝毒合成研究的应用 被引量:1
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作者 张昊宇 谭志军 +3 位作者 郑关超 吕颂辉 杨越聪 吴海燕 《海洋与湖沼》 CAS CSCD 北大核心 2023年第2期457-464,共8页
选取具有显著产毒差异的利玛原甲藻(Prorocentrum lima)SHG株与2XS株为研究对象,以2-^(13)C-甘氨酸为示踪原料结合高分辨质谱方法,为腹泻性贝类毒素及其酯化态毒素合成与代谢途径的研究提供新方法和思路。结果表明,两株藻共发现16种腹... 选取具有显著产毒差异的利玛原甲藻(Prorocentrum lima)SHG株与2XS株为研究对象,以2-^(13)C-甘氨酸为示踪原料结合高分辨质谱方法,为腹泻性贝类毒素及其酯化态毒素合成与代谢途径的研究提供新方法和思路。结果表明,两株藻共发现16种腹泻性贝毒及其酯化态毒素成分。对照培养条件下SHG株(大田软海绵酸毒素含量为7.88 pg/cell,鳍藻毒素1含量为4.35 pg/cell)的产毒能力高于2XS株(大田软海绵酸毒素5.70pg/cell),而甘氨酸作为氮源培养条件可显著提高两株藻的产毒总量(P<0.05)。^(13)C-甘氨酸标记组与甘氨酸培养组单细胞产毒量无显著变化(P>0.05)。腹泻性贝毒被标记后其同位素异构体丰度发生变化,其中酯化态受^(13)C标记的影响程度更高,二级质谱图清晰表示出其碎片离子及脱水峰的标记情况。该方法直观阐明了甘氨酸可作为P.lima标记原料的产毒供体,并使用稳定同位素标记方法首次实现了酯化态的同步标记,有助于腹泻性贝毒生成机制的进一步研究。 展开更多
关键词 利玛原甲藻 腹泻性贝类毒素 酯化态 13c同位素示踪 四极杆/静电场轨道阱高分辨质谱
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一种基于高分辨液质联用仪的^(13)C标记葡萄糖同位素丰度检测方法 被引量:2
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作者 范若宁 赵雅梦 +5 位作者 王储尧 廖望 解龙 赵诚 罗勇 雷雯 《化学试剂》 CAS 北大核心 2023年第8期122-126,共5页
[U-^(13)C_(6)]葡萄糖是一种重要的同位素试剂,在代谢组学等生物医药领域具有重要应用。开发了一种基于超高效液相色谱-高分辨质谱联用仪的[U-^(13)C6]葡萄糖同位素丰度检测方法。在确定检测[U-^(13)C_(6)]葡萄糖同位素丰度的适用条件后... [U-^(13)C_(6)]葡萄糖是一种重要的同位素试剂,在代谢组学等生物医药领域具有重要应用。开发了一种基于超高效液相色谱-高分辨质谱联用仪的[U-^(13)C6]葡萄糖同位素丰度检测方法。在确定检测[U-^(13)C_(6)]葡萄糖同位素丰度的适用条件后,进行液质联用上机检测,根据不同同位素标记模式峰的强度值进行丰度计算;考察了样品浓度、质谱分析图数、流动相背景干扰对同位素丰度计算的影响,在最优条件下取出峰时间窗口内所有质谱图并扣除流动相背景干扰后,重复7次进样测得浓度为10μg/mL的[U-^(13)C_(6)]葡萄糖试剂^(13)C丰度为99.05%(理论值99.2%)且RSD为0.15%。该方法无需复杂的前处理过程,具有较好的准确性和稳定性,是一种具有潜力的同位素试剂质量控制方法。 展开更多
关键词 [U-^(13)c_(6)]葡萄糖 高分辨质谱 同位素丰度检测
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Trace element geochemistry and stable isotopic(δ^(13)C andδ^(15)N)records of the Paleocene coals,Salt Range,Punjab,Pakistan 被引量:1
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作者 Noshin Masood Tehseen Zafar +2 位作者 Karen A.Hudson-Edwards Hafiz U.Rehman Abida Farooqi 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2022年第3期551-561,共11页
The Paleocene coals of the Salt Range in the Punjab Province of Pakistan have great economic potential;however,their trace element and stable isotopic characteristics have not been studied in detail except for a few s... The Paleocene coals of the Salt Range in the Punjab Province of Pakistan have great economic potential;however,their trace element and stable isotopic characteristics have not been studied in detail except for a few sporadic samples.In this study,a total of 59 coal samples of which 14 are obtained from open cast mines have been investigated for elemental composition andδ^(13)C-δ^(15)N isotopic signatures.Average contents of trace elements such as Co,Cr,Cu,Pb,Sr,Th,U,V,and Zn are 7.4,41.7,11.2,12.5,90.2,4.0,1.9,128,and 31.1 mg/kg,respectively.These values,when compared with the World Coal Clarke values,were relatively higher in low-rank coals in comparison with Clarke values for brown coals.Likewise,As(20.4 mg/kg),Co(6.6 mg/kg),Cr(22.4 mg/kg),Cu(^(13).3 mg/kg),Pb(19.2 mg/kg),Sr(^(15)4.7 mg/kg),Th(2.5 mg/kg),V(47.8 mg/kg),and Zn(75.1 mg/kg)were significantly higher in the sub-bituminous to bituminous coals of the Salt Range.Mineralogical analysis,based on X-ray diffraction and energy dispersive X-ray spectroscopy,revealed that the studied samples contain illite,kaolinite calcite,gypsum,pyrite,and quartz.Elemental affinity with organic and inorganic phases of coals calculated by an indirect statistical approach indicated a positive association of ash content with Ag,Al,Co,Cr,Cs,Cu,Mn,P,Rb,Pb,Th,U,and V,suggesting the presence of inorganic components in studied coals.However,As,Fe,Sr,and Zn exhibit negative correlations that imply their association with the organic fraction.Theδ^(13)C andδ^(15)N isotopic range and average−24.94‰to−25.86‰(−25.41‰)and−2.77‰to 3.22‰(0.96‰),respectively,reflecting 3C type modern terrestrial vegetation were common in the palaeomires of studied coal seams.In addition,the trivial variations of 0.92‰and 0.45‰among^(13)C and^(15)N values can be attributed to water level fluctuations and plant assemblies. 展开更多
关键词 coal Salt Range Pakistan Geochemistry Trace elements δ^(13)c andδ^(15)N isotopes
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气相色谱法测定稳定同位素^13(C)标记辛酸纯度的不确定度评定
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作者 赵诚 孙雯 袁璋晶 《肥料与健康》 CAS 2023年第1期65-69,共5页
根据行业标准《稳定同位素^13(C)标记的辛酸》(HG/T 5941—2021),采用气相色谱法测定稳定同位素^13(C)标记的辛酸纯度,对测定过程中的不确定度来源进行了分析,主要为标准溶液配制、标准曲线拟合、样品制备和样品测量重复性等。按《测定... 根据行业标准《稳定同位素^13(C)标记的辛酸》(HG/T 5941—2021),采用气相色谱法测定稳定同位素^13(C)标记的辛酸纯度,对测定过程中的不确定度来源进行了分析,主要为标准溶液配制、标准曲线拟合、样品制备和样品测量重复性等。按《测定不确定度评定与表示》(JJF 1059.1—2012)的规定进行不确定度计算,稳定同位素^13(C)标记的辛酸纯度的测量不确定度来源主要为标准溶液配制与标准曲线拟合,其合成标准不确定度为0.817%,扩展不确定度为1.6%,测定结果为99.0%±1.6%(k=2)。 展开更多
关键词 稳定同位素 ^13(c)标记辛酸 气相色谱法 不确定度
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酶催化法测定^(13)C标记尿素同位素丰度
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作者 雷雯 解龙 宋明鸣 《应用技术学报》 2023年第4期299-304,共6页
建立酶催化法测定^(13)C标记尿素同位素丰度的快速检测方法。在特殊制作的三球反应管中经过2步反应:(1)利用脲酶的专一性将尿素-^(13)C催化转化生成碳酸铵-^(13)C,在40℃下,反应5 min;(2)经过酸化生成^(13)C标记CO_(2),将气体引入MAT-27... 建立酶催化法测定^(13)C标记尿素同位素丰度的快速检测方法。在特殊制作的三球反应管中经过2步反应:(1)利用脲酶的专一性将尿素-^(13)C催化转化生成碳酸铵-^(13)C,在40℃下,反应5 min;(2)经过酸化生成^(13)C标记CO_(2),将气体引入MAT-271气体同位素质谱仪中,检测质荷比为44和45离子流强度,并计算^(13)C同位素丰度。结果表明,测定值与标样的^(13)C标示值误差在0.1%以内,精密度RSD<0.1%,建立的检测方法与现行行业标准方法测试结果基本一致,该方法操作相对简便快速、专一性强,适用于呼气试验诊断试剂及原料药尿素-^(13)C中同位素丰度的快速检测。 展开更多
关键词 酶催化法 脲酶 尿素-^(13)c 气体同位素质谱仪 ^(13)c同位素丰度
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Stable isotopes in aquatic food web of an artificial lagoon in the Hangzhou Bay,China
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作者 全为民 施利燕 陈亚瞿 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期489-497,共9页
Stable isotope values, δ13C and δ15N, were determined for four primary producers and 19 dominant consumers in a small artificial lagoon located in Hangzhou Bay. Based on these results the major pathways for energy f... Stable isotope values, δ13C and δ15N, were determined for four primary producers and 19 dominant consumers in a small artificial lagoon located in Hangzhou Bay. Based on these results the major pathways for energy flow and trophic structure of the artificial lagoon ecosystem were characterized. The mean δ13C values for the 19 consumers ranged from -22.99‰ to -14.24‰. Apart from so-iny mullet Liza haematocheila, the other 18 consumers had intermediate δ13C values between those of epibenthic microalgae and particulate organic matter (POM). The results of a multiple source linear mixing model (IsoSource model) indicated that 50% or more of the organic carbon in the tissues of most consumers was derived from epibenthic microalgae. This indicated that these primary producers were the main food source fueling the lagoon food web. The mean δ15N values for the 19 consumers varied between 4.93‰ and 12.97‰ and indicated four trophic levels in the lagoon. Four macroinvertebrates and zooplankton represented the primary consumers, whilst the other 14 consumers occupied the secondary and tertiary consumer levels. The 19 consumers were divided into three trophic guilds (detritivores/suspension feeders, omnivores and carnivores). 展开更多
关键词 isotope ^13c ^15N lsoSource model trophic level food web
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Temporal and spatial variations of carbon isotope signature reveal substantial contribution of bracts and internode assimilates to grain filling of japonica rice
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作者 Mengjiao Jiang Hongfa Xu +4 位作者 Nianfu Yang Ganghua Li Yanfeng Ding Matthew J.Paul Zhenghui Liu 《The Crop Journal》 SCIE CSCD 2021年第2期271-281,共11页
Carbon isotope composition(δ^(13)C)of a plant organ is an inherent signature reflecting its physiological property,and thus is used as an integrative index in crop breeding.It is also a non-intrusive method for quant... Carbon isotope composition(δ^(13)C)of a plant organ is an inherent signature reflecting its physiological property,and thus is used as an integrative index in crop breeding.It is also a non-intrusive method for quantifying the relative contribution of different source organs to grain filling in cereals.Using the samples collected from two-year field and pot experiments with two nitrogen(N)fertilization treatments,we investigated the temporal and spatial variations of δ^(13)C in source organs of leaf,sheath,internode,and bracts,and in sink organ grain.Constitutive nature of δ^(13)C was uncovered,with an order of leaf(−27.84‰)<grain(−27.82‰)<sheath(−27.24‰)<bracts(−26.81‰)<internode(−25.67‰).For different positions of individual organs within the plant,δ^(13)C of the leaf and sheath presented a diminishing trend from the top(flag leaf and its sheath)to the bottom(the last leaf in reverse order and its sheath).No obvious pattern was found for the internode.For temporal variations, δ^(13)C of the leaf and sheath had a peak(the most negative)at 10 days after anthesis(DAA),whereas that of the bracts showed a marked increase at the time point of anthesis,implying a transformation from sink to source organ.By comparing the δ^(13)C in its natural abundance in the water-soluble fractions of the sheath,internode,and bracts with the δ^(13)C in mature grains,the relative contribution of these organs to grain filling was assessed.With reference to the leaf,the internode accounted for as high as 32.64%and 42.56%at 10 DAA and 20 DAA,respectively.Meanwhile,bracts presented a larger contribution than the internode,with superior bracts being higher than inferior bracts.In addition,N topdressing reduced the contribution of the internode and bracts.Our findings clearly proved the actual significance of non-foliar organs of the internode and bracts for rice yield formation,thus extending our basic knowledge of source and sink relations. 展开更多
关键词 japonica rice carbon isotope composition(δ^(13)c) Temporal and spatial variations Source and sink relation Grain yield formation
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稻秆木素侧链^(13)C同位素示踪及固体^(13)CNMR分析 被引量:24
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作者 顾瑞军 谢益民 +2 位作者 曾绍琼 伍红 安田征市 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2002年第6期1073-1076,共4页
在水稻 (Oryza sativa L.)生长过程中 ,向其茎秆部节间的空腔分别注入在侧链α,β,γ位带有 1 3C标记的松柏醇葡萄糖甙 ,得到 1 3C标记的稻秆木素 ,用高分辨率固体核磁 1 3C NMR对其组织进行分析 ,发现外源性的松柏醇葡萄糖甙并不影响... 在水稻 (Oryza sativa L.)生长过程中 ,向其茎秆部节间的空腔分别注入在侧链α,β,γ位带有 1 3C标记的松柏醇葡萄糖甙 ,得到 1 3C标记的稻秆木素 ,用高分辨率固体核磁 1 3C NMR对其组织进行分析 ,发现外源性的松柏醇葡萄糖甙并不影响水稻中木素的正常合成 .证明了 β-O-4,β-β,β-5和 β-1结构是稻秆原本木素中的主要结构 ,另外还有少量的松柏醇和阿魏酸类结构 ,并证实木素在 展开更多
关键词 稻秆 木素 同位素示踪 13 核磁共振 分离 造纸工业 制浆
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DHP的^(13)C同位素示踪及固体^(13)C NMR分析 被引量:16
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作者 顾瑞军 谢益民 +1 位作者 伍红 赖燕明 《林产化学与工业》 EI CAS CSCD 2002年第1期1-6,共6页
以侧链α位带13 C同位素标记的松柏醇葡萄糖苷作为起始物 ,在实验室中模拟木质素生物合成过程人工合成脱氢聚合物 (DHP) ,得到带13 C标记的DHP。用高分辨率固体13 CNMR和红外光谱对DHP进行了分析。红外分析结果显示 :该实验条件下用松... 以侧链α位带13 C同位素标记的松柏醇葡萄糖苷作为起始物 ,在实验室中模拟木质素生物合成过程人工合成脱氢聚合物 (DHP) ,得到带13 C标记的DHP。用高分辨率固体13 CNMR和红外光谱对DHP进行了分析。红外分析结果显示 :该实验条件下用松柏醇葡萄糖苷合成的DHP同天然银杏木材的磨木木质素 (MWL)在组成和结构上有较好的相似性。13 CNMR证明了 β O 4、β β、β 5和松柏醇结构为DHP的主要结构 ,另有少量香兰素结构和α 展开更多
关键词 脱氢聚合物 木质素 碳-13 同位素示踪 松伯醇 生物合成 同位素标记 核磁共振
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河西走廊中部沙漠植物δ^(13)C值的特点及其对水分利用效率的指示 被引量:35
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作者 苏培玺 陈怀顺 李启森 《冰川冻土》 CSCD 北大核心 2003年第5期597-602,共6页
通过分析河西走廊中部沙漠中几种木本植物叶片或同化枝的稳定碳同位素比率(δ13C)和碳同位素辨别力(Δ),以其作为水分利用效率(WUE)的指示,研究了本区沙漠植物叶片或同化枝δ13C值的季节变化特点,以及不同生境和不同水分状况下δ13C值... 通过分析河西走廊中部沙漠中几种木本植物叶片或同化枝的稳定碳同位素比率(δ13C)和碳同位素辨别力(Δ),以其作为水分利用效率(WUE)的指示,研究了本区沙漠植物叶片或同化枝δ13C值的季节变化特点,以及不同生境和不同水分状况下δ13C值的差异,并比较研究了绿洲防护林树种及绿洲作物.结果表明:梭梭和沙拐枣同化枝的δ13C值分别为-14 31‰和-14 82‰,Δ值在5‰~6‰之间;柠条、泡泡刺、花棒和红沙叶片的δ13C值分别为-25 75‰、-25 79‰、-26 38‰和-28 05‰,Δ值在16‰~20‰之间.几种沙漠植物长期水分利用效率大小的顺序为:梭梭≈沙拐枣>柠条≈泡泡刺≈花棒>红沙. 展开更多
关键词 河西走廊 沙漠植物 稳定碳同位素比率 稳定碳同位素辨别力 水分利用效率
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中国典型城市垃圾填埋场甲烷δ^(13)C特征研究 被引量:3
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作者 刘建国 邵可声 +2 位作者 邵敏 张远航 唐孝炎 《环境科学研究》 EI CAS CSCD 北大核心 2004年第5期41-43,51,共4页
城市垃圾填埋场是全球甲烷源中具有可削减意义的重要人为甲烷源。甲烷13C同位素特征是区域和全球甲烷源源强恒算的一个重要定量因子。研究测得中国阿苏卫垃圾填埋场甲烷δ13C特征值的一般范围为-54 9‰~-49 0‰,反映出了城市垃圾填埋... 城市垃圾填埋场是全球甲烷源中具有可削减意义的重要人为甲烷源。甲烷13C同位素特征是区域和全球甲烷源源强恒算的一个重要定量因子。研究测得中国阿苏卫垃圾填埋场甲烷δ13C特征值的一般范围为-54 9‰~-49 0‰,反映出了城市垃圾填埋场普遍的甲烷δ13C特征。研究表明,在排气系统方面与国外垃圾填埋场的结构差异和特定的场地条件,使阿苏卫垃圾填埋场排气系统和覆土层排放的甲烷都经历了相当程度的氧化,二者的甲烷δ13C特征值差异并不显著,普遍略重于国外相应研究结果,显示出较为显著的氧化特征。 展开更多
关键词 城市垃圾填埋场 甲烷 同位素 δ^13c特征
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气相色谱-质谱联用选择离子监测方法定量分析低浓度胞内游离氨基酸的^(13)C同位素丰度 被引量:9
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作者 李敏超 黄明志 +3 位作者 刘玉伟 储炬 庄英萍 张嗣良 《分析化学》 SCIE EI CAS CSCD 北大核心 2014年第10期1408-1413,共6页
胞内游离氨基酸具有周转快的特点,其13C同位素丰度能快速反映胞内代谢状态的变化。但胞内游离氨基酸的浓度很低,现有的基于气相色谱-质谱联用全扫描模式的13C同位素丰度检测方法不能满足要求。本研究考察理论上检测精度更高的选择离子... 胞内游离氨基酸具有周转快的特点,其13C同位素丰度能快速反映胞内代谢状态的变化。但胞内游离氨基酸的浓度很低,现有的基于气相色谱-质谱联用全扫描模式的13C同位素丰度检测方法不能满足要求。本研究考察理论上检测精度更高的选择离子监测方法在胞内游离氨基酸13C同位素丰度分析中应用的可能性。首先在全扫描模式下分析了不同氨基酸的断裂规律,找出与每种氨基酸对应的特征碎片,建立起包含有16种胞内游离氨基酸的特征碎片库。利用此特征碎片库,在样品分析时只需检测特定m/z处的信号,从而实现选择离子监测,提高信号质量。对标准品的检测结果表明,与全扫描模式相比,本方法的信噪比、测量精度和准确性分别提高了17倍、2倍和3.8倍。在对辅酶Q10生产菌株样品的分析中,本方法成功检测出8种胞内游离氨基酸的同位素丰度。 展开更多
关键词 选择离子监测 13c同位素丰度 气相色谱-质谱联用 游离氨基酸
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纤维素^(13)C同位素示踪法研究纤维素与木素连接方式 被引量:4
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作者 向松明 谢益民 +1 位作者 杨海涛 姚兰 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2013年第9期2488-2491,共4页
为了阐明裸子植物中纤维素与木素之间的连接方式,从多糖的角度分析糖单元与木素苯丙烷结构单元之间的共价键连接方式,合成了带6-13 C标记的纤维素前驱物尿苷二磷酸葡萄糖,并将其与PAL酶的抑制剂AOPP及外源性木素前驱物松柏醇-β-D-葡萄... 为了阐明裸子植物中纤维素与木素之间的连接方式,从多糖的角度分析糖单元与木素苯丙烷结构单元之间的共价键连接方式,合成了带6-13 C标记的纤维素前驱物尿苷二磷酸葡萄糖,并将其与PAL酶的抑制剂AOPP及外源性木素前驱物松柏醇-β-D-葡萄糖苷一起投入生长中的银杏植物体内。碳13丰度检测得知纤维素在细胞壁的沉积主要是从在初生壁开始,高分辨率固体核磁13 C NMR分析证实了纤维素6位碳与木素以苯甲醚键等方式连接。 展开更多
关键词 纤维素 13c标记 cP/MAS NMR 木素-碳水化合物复合体
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小麦不同进化材料叶与非叶器官C4光合酶活性及δ^(13)C值差异 被引量:4
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作者 魏爱丽 杨茂 +2 位作者 黄琴 张英华 王志敏 《麦类作物学报》 CAS CSCD 北大核心 2021年第2期183-190,共8页
为明确小麦进化过程中C_(4)代谢酶活性的变化趋势,以二倍体小麦种(野生一粒小麦、栽培一粒小麦、拟斯卑尔脱山羊草、粗山羊草)、四倍体小麦种(野生二粒小麦、栽培二粒小麦、阿拉拉特、提莫菲维小麦)及六倍体小麦种(斯卑尔脱小麦、普通小... 为明确小麦进化过程中C_(4)代谢酶活性的变化趋势,以二倍体小麦种(野生一粒小麦、栽培一粒小麦、拟斯卑尔脱山羊草、粗山羊草)、四倍体小麦种(野生二粒小麦、栽培二粒小麦、阿拉拉特、提莫菲维小麦)及六倍体小麦种(斯卑尔脱小麦、普通小麦)为试验材料,对不同染色体倍数小麦种不同绿色器官光合碳同化酶(PEPC、RuBPC、NADP-MDH、NADP-ME、NAD-ME)活性及稳定碳同位素(δ^(13)C)值进行了比较分析。结果表明,在同一种内,非叶器官(叶鞘、穗下节间、芒、护颖、外颖)RuBPC活性显著低于旗叶,除六倍体小麦品种外,其余小麦材料的PEPC及其他C_(4)途径酶活性均高于叶片。在小麦进化过程中,随着染色体倍数的增加,旗叶片的C_(3)和C_(4)同化酶活性均上升,且PEPC/RuBPC活性比值显著增加;非叶器官的RuBPC活性增加,但PEP羧化酶及其他C_(4)途径酶活性下降,PEPC/RuBPC活性比值显著降低。旗叶和穗器官的δ^(13)C值均在C3途径范围内,穗器官的δ^(13)C值高于叶片;随染色体倍数的增加,旗叶δ^(13)C值增高,而穗器官的δ^(13)C值下降。综合来看,小麦非叶器官具有较强的C_(4)光合酶活性,在进化过程中,其C4酶活性趋向减弱,而旗叶的C_(4)酶活性则趋向增加。 展开更多
关键词 小麦 非叶器官 进化 PEP羧化酶 稳定碳同位素(δ^(13)c)
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