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Fractionation of soil organic carbon in a calcareous soil after longterm tillage and straw residue management

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Journal of Integrative Agriculture 2022年第12期21卷 3611-3625页

作者： LI Teng-teng zhang Jiang-zhou zhang hong-yan Peter CHRISITE zhang Jun-ling Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems&CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones South China Botanical GardenChinese Academy of Sciences(CAS)Guangzhou 510650P.R.China College of Resources and Environmental Sciences China Agricultural University/National Academy of Agriculture Green Development/Key Laboratory of Plant–Soil InteractionsMinistry of EducationBeijing 100193P.R.China College of Resources and Environment/International Magnesium Institute Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China

No-tillage(NT)and straw return(S)collectively affect soil organic carbon(SOC).However,changes in the organic carbon pool have been ***,we assessed the quantity and quality of SOC after 11 years of tillage and straw return on the North China *** of SOC and its labile fractions(particulate organic carbon(POC),potassium permanganate-oxidizable organic carbon(POXC),microbial biomass carbon(MBC),and dissolved organic carbon(DOC)),components of DOC by fluorescence spectroscopy combined with parallel factor analysis(PARAFAC),and the chemical composition of SOC by 13C NMR(nuclear magnetic resonance)spectroscopy were *** comprised conventional tillage(CT)and NT under straw removal(S0),return of wheat straw only(S1),or return of both wheat straw and maize residue(S2).Straw return significantly increased the concentrations and stocks of SOC at 0–20 cm depth,but NT stratified them with enrichment at 0–10 cm and a decrease at 10–20 cm compared to CT,especially under *** C fractions showed similar patterns of variation to that of SOC,with POC and POXC more sensitive to straw return and the former more sensitive to *** fluorescence components of DOC were identified,mainly comprising humic-like substances with smaller amounts of fulvic acid-like substances and *** return significantly decreased the fluorescence index(FI)and autochthonous index(BIX)and increased the humification index(HIX).No-tillage generally increased HIX in topsoil but decreased it and increased the FI and BIX below the *** abudance order of the chemical composition of SOC was:O-alkyl C>alkylC>aromatic-C>***,NT under S2 effectively increased SOC and its labile C forms and DOC humification in topsoil and microbially-derived DOC below the *** of both wheat and maize straw was a decisive factor in promoting SOC in the plow *** stratification of SOC under NT may confer a long-term influence on

关键词： soil organic carbon labile C fractions EEM fluorescence PARAFAC analysis 13C NMR spectrometry

论高职教育中如何促进高品质课堂教学——基于师生互动的视角

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云南开放大学学报 2024年第3期26卷 98-103页

作者：张艳红鲍顺萍张永萍云南开放大学云南昆明650500 昆明幼儿师范高等专科学校云南昆明651701 云南机电职业技术学院云南昆明650203

在课堂教学过程提升教学质量,课堂教学设计与师生的良性互动是关键。经过文献研究和课堂教学观察,目前高职课堂教学中存在师生互动形式较为单一、师生互动频率低、互动时间短、学生学习动机不明确、师生互动机会不均等困境,需要教师在... 详细信息

在课堂教学过程提升教学质量,课堂教学设计与师生的良性互动是关键。经过文献研究和课堂教学观察,目前高职课堂教学中存在师生互动形式较为单一、师生互动频率低、互动时间短、学生学习动机不明确、师生互动机会不均等困境,需要教师在课堂教学中通过师生互动发挥积极引导作用、结合课程目标及专业特色创新课堂教学模式、在课堂教学中融入社会情感支持、构建“学校、教师、学生”联动机制等策略来提升课堂教学质量,为打造高品质课堂教学提供参考。

关键词：师生互动课堂教学教学质量教学实践

CHARACTERISTICS OF PRESSURE DROP AND CORRELATION OF FRICTION FACTORS FOR SINGLE-PHASE FLOW IN ROLLING HORIZONTAL PIPE

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Journal of Hydrodynamics 2009年第5期21卷 614-621页

作者： zhang Jin-hong yan Chang-qi GAO Pu-zhen College of Nuclear Science and Technology Harbin Engineering University Harbin 150001 China

Gas-liquid two-phase flow occurs increasingly in some dynamic devices operating in the oceanic condition. The relative data are limited with respect to flow characteristics, so the present study is to investigate systematically single-phase pressure drop, and to develop the theory for frictional factor under the roiling condition. Using deionized water as the test fluid, a series of experiments of single-phase flow were conducted in pipe with the inner diameter of 34.5 ram. The test section was horizontally settled on the rolling apparatus, and its regularity was similar to simple harmonic motion. It is found that the pressure drop during rolling motion fluctuate with the change of the rolling period and rolling angle, which is significantly different from fluid motion in a steady state. By the contrast between experiment results and stable-state theory values, existing correlations can not predict present frictional factor very well. Therefore, in the present article, the single-phase frictional factor is correlated with the Reynolds number for rolling motion, and its computated results agree well with experimental data.

关键词： single-phase flow pressure drop friction factor horizontal pipe rolling motion

广西小花老鼠簕可培养细菌多样性及促生、防病、产酶活性分析

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南方农业学报 2024年第4期55卷 973-984页

作者：殷豆豆黄宏智宋超东刘睿梁颖陆君铭谢俊杰阎冰申乃坤张红岩广西民族大学海洋与生物技术学院/广西多糖材料与改性重点实验室广西南宁530006 广西科学院广西红树林研究中心/广西红树林保护与利用重点实验室广西北海536007

【目的】分析广西小花老鼠簕可培养细菌多样性及促生、防病、产酶活性,为小花老鼠簕种群恢复及筛选可利用菌种资源提供参考依据。【方法】采用稀释涂布法对小花老鼠簕根、茎、叶及根际土壤可培养细菌进行分离、纯化;对菌株的16S rRNA序... 详细信息

【目的】分析广西小花老鼠簕可培养细菌多样性及促生、防病、产酶活性,为小花老鼠簕种群恢复及筛选可利用菌种资源提供参考依据。【方法】采用稀释涂布法对小花老鼠簕根、茎、叶及根际土壤可培养细菌进行分离、纯化;对菌株的16S rRNA序列进行PCR扩增,测序结果经EzBioCloud比对确定菌株的分类地位;通过功能培养基对菌株的促生[溶磷、固氮、产吲哚乙酸(IAA)和分泌铁载体]、防病(香蕉枯萎病)及产酶(蛋白酶、淀粉酶和纤维素酶)活性进行分析。【结果】从小花老鼠簕根、茎、叶及根际土壤共筛选获得细菌159株,根据菌落形态及16S rRNA测序结果排除重复后为65株,隶属于8目7科14属,其中芽孢杆菌属(Bacillus)为优势菌属,占分离菌株的64.62%,同时发现1株潜在新种(Gxun-T66),与已发现菌株相似性仅为98.49%;植物促生防病活性结果显示,溶磷菌株34株、固氮菌株31株、产IAA菌株20株、分泌铁载体菌株17株,其中北澳伯克霍尔德氏菌(Burkholderia territorii)Gxun-T33的溶磷和分泌铁载体能力最强;29株对香蕉枯萎病尖孢镰刀菌(Fusarium oxysporum ***)有明显抑制作用,其中暹罗芽孢杆菌(Bacillus siamensis)Gxun-T25的抑菌效果最好,抑菌率达69.67%;产酶活性结果显示,产蛋白酶菌株56株,产淀粉酶49株,产纤维素酶48株,同时产3种酶活性的菌株有34株,占分离菌株的52.31%。【结论】红树植物小花老鼠簕富含微生物资源且具备促生、防病及产酶活性,同时发现1株潜在新种。

关键词：小花老鼠簕可培养细菌促生拮抗菌酶活性

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从细胞衰老视角论中医药防治糖尿病心肌病

中国中西医结合杂志 2024年第2期44卷 222-227页

作者：漆仲文赵俊男张艳虹王青刘玥徐凤芹中国中医科学院老年医学研究所北京100091 中国中医科学院博士后科研流动站北京100091 国家中医药管理局病证结合防治血管衰老重点研究室北京100091 中国中医科学院西苑医院国家中医心血管病临床医学研究中心北京100091

糖尿病心肌病是糖尿病心脏病主要并发症。笔者从糖脂代谢导致的代谢稳态失衡为主线,以细胞衰老为切入点,全面梳理糖尿病心肌病不同阶段病机演变特点,总结出因虚致衰是始动环节,因毒致衰是加重因素,因瘀致衰是表现形式。围绕细胞衰老提... 详细信息

糖尿病心肌病是糖尿病心脏病主要并发症。笔者从糖脂代谢导致的代谢稳态失衡为主线,以细胞衰老为切入点,全面梳理糖尿病心肌病不同阶段病机演变特点,总结出因虚致衰是始动环节,因毒致衰是加重因素,因瘀致衰是表现形式。围绕细胞衰老提出病证结合指导下的防治策略,认为未病先防理念下的主动健康模式是关口前移的根本,借助现代生物信息技术,形成不同阶段的“病-证-时-方”个体诊疗方案是关键,联合多组学技术阐明细胞衰老不同阶段证候学实质是抓手。为糖尿病心肌病防治提供新视角。

关键词：糖尿病心肌病血管稳态糖脂代谢细胞衰老防治策略中医药

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320份蚕豆蛋白质含量的SSR关联分析

作物学报 2024年第11期50卷 2775-2786页

作者：陈志凯周仙莉张红岩滕长才侯万伟青海大学青海西宁810016 青海省农林科学院青海西宁810016 国家农作物种质资源复份库青海西宁810016

蚕豆是重要的植物蛋白源作物,富含8种必须氨基酸且含量均衡,挖掘蚕豆蛋白质相关基因不仅有利于优质蛋白蚕豆品种选育,而且对于未来植物蛋白的需求具有重要意义。本研究以320份蚕豆种质资源为材料,测定了1年3个点(青海西宁市、互助县、... 详细信息

蚕豆是重要的植物蛋白源作物,富含8种必须氨基酸且含量均衡,挖掘蚕豆蛋白质相关基因不仅有利于优质蛋白蚕豆品种选育,而且对于未来植物蛋白的需求具有重要意义。本研究以320份蚕豆种质资源为材料,测定了1年3个点(青海西宁市、互助县、湟源县)的蛋白质含量,并用筛选的132对SSR引物进行了蚕豆蛋白质含量关联分析。结果表明,蛋白质含量范围在19.51%~54.34%,3个地点的变异系数分别为10.835、20.865、13.380,均符合正态分布,具有表型多样性。132个标记在320份材料中共检测到778个多态性位点,平均等位基因数为6,变幅为3~12,多态性信息量(PIC)的变幅为0.1527(V1797)~0.8225(SSR-12192),平均值为0.5583,PIC值大于平均值的标记占总数的49.24%,选用的标记基因遗传多样性较高;遗传结构分析将320份材料分成2个亚群,其中亚群I有176份材料,亚群II有107份材料,其余37份没有明显的群类归属特性,为混合类群,供试群体结构较为单一;利用GLM和MLM 2种关联分析模型共检测到与蛋白质含量显著相关的22个SSR标记,有3个SSR标记与蛋白质含量极显著相关(SSR-10894、SSR-12695、V1929),在多个环境中均检测到SSR-13584,解释率范围在4.07%~5.19%,V1929在湟源县的2种模型关联分析中均极显著相关,解释率分别为10.00%、9.20%。该研究结果可为亲本选配及蚕豆蛋白相关基因挖掘及品质育种提供理论基础。

关键词：蚕豆蛋白质含量 SSR标记关联分析

Mapping and Assessing Typhoon-induced Forest Disturbance in Changbai Mountain National Nature Reserve Using Time Series Landsat Imagery

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Journal of Mountain Science 2015年第2期12卷 404-416页

作者： GUO Xiao-yi zhang hong-yan WANG Ye-qiao John Clark School of Geographical Sciences Northeast Normal University Department of Natural Resources Science University of Rhode Island

Monitoring forest disturbances is important for understanding changes in ecosystems. The 1986 Typhoon Vera was a serious disturbance that severely impacted the forest ecosystems of Changbai Mountain National Nature Reserve. Although the typhoon disturbance occurred more than two decades ago, the effects of the typhoon still remain within the study area. Few studies have focused on mapping and assessing disturbances across broad spatial and temporal scales. For this study, we first generated a map of forest composition prior to the typhoon disturbance, which served as a baseline data for the extraction of disturbed area. Then, the Disturbance Index(DI) method was tested for mapping the extent and magnitude of disturbance in the study area by applying a Tasseled Cap transformation to the Landsat imagery. The Landsatbased DI method estimated that an area of 13,764.78 ha of forest was disturbed by the typhoon. Based on visual assessments, these results correspond closely with the reference map derived from ground surveys. These results also revealed the influence of local topographic features on the distribution of windthrow areas. Windthrow areas were more pronounced inareas with elevations ranging from 1,000 to 2,000 m, slopes of less than 10 degrees, and southwestern to northwestern aspects. In addition, the relatively long(25 years) post-typhoon recovery period assessed by this study provided a more comprehensive analysis of the dynamics of forest recovery processes over time. Windthrow areas did not recover immediately after the typhoon, likely due to forest management practices enacted at the time. So far, forest recovery has proceeded more rapidly at elevations below 1,400 m, particularly on western slopes within the study area. Finally, a time series of DI values within the study period suggests a secondary disturbance may have occurred between 2000 and 2001.

关键词： Typhoon Vera Windthrow areas Disturbance Index(DI) Topographic features Forest recovery process

The driving factors and their interactions of fire occurrence in Greater Khingan Mountains, China

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Journal of Mountain Science 2020年第11期17卷 2674-2690页

作者： GUO Xiao-yi zhang hong-yan WANG Ye-qiao ZHAO Jian-jun zhang Zheng-xiang Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains Ministry of EducationSchool of Geographical SciencesNortheast Normal UniversityChangchun 130024China Department of Natural Resources Science University of Rhode IslandKingstonRhode Island 02881USA

Fire is an important disturbance in terms of forest management.A comprehensive understanding of the relationships between the spatial distribution of fire occurrence and its driving factors are critical for effective forest fire *** reveal biogeoclimatic and anthropogenic influences,this study introduced a geographical detector model to quantitatively examine the effects of multiple individual factors and their combinations on spatial patterns of fire occurrence in the Greater Khingan Mountains between 1980 and *** geographical detector computes the explanatory power(q value)to measure the connection between driving factors and spatial distributions of fire *** density estimation revealed the spatial variability of fire occurrence which was impacted by bandwidth.30 km might be the optimal bandwidth in this *** biogeoclimatic and anthropogenic effects were explored using topography,climate,vegetation,and human activity factors as *** results indicated that solar radiation had the most influence on the spatial pattern of fire occurrence in the study ***,Normalized Difference Vegetation Index,temperature,wind speed,and vegetation type were determined as the major driving *** various groups of driving factors,climate variables were the dominant factors for the density of fire occurrence,while vegetation exerted a strong *** interactions between the driving factors had a more significant impact than a single ***,the factors in the topography and human activity groups exhibited weaker ***,their effects were enhanced when combined with climate and vegetation *** study improves our understanding of various driving factors and their combined influences on fire occurrences of the study area in a spatial *** findings of this study verify that the geographical detector is applicable in revealing the driving factors of fire occurrence.

关键词： Fire occurrence Driving factors Interactions Geographical detector Greater Khingan Mountains

超高效液相色谱-四极杆/静电场轨道阱质谱法快速筛查减肥食品中非法添加物

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质谱学报 2024年第5期45卷 712-722页

作者：张虹艳谢瑜杰常巧英吴兴强夏寒仝凯旋范春林陈辉中国检验检疫科学研究院北京100176 河北大学化学与材料科学学院河北保定071002

本研究建立了超高效液相色谱-四极杆/静电场轨道阱质谱(UHPLC-Q/Orbitrap MS)法快速筛查减肥类食品中非法添加的化学药物。采用乙腈超声提取样品,使用UHPLC-Q/Orbitrap MS采集数据,以青梅和果冻为基质,外标法定量分析。基于7种自建的减... 详细信息

本研究建立了超高效液相色谱-四极杆/静电场轨道阱质谱(UHPLC-Q/Orbitrap MS)法快速筛查减肥类食品中非法添加的化学药物。采用乙腈超声提取样品,使用UHPLC-Q/Orbitrap MS采集数据,以青梅和果冻为基质,外标法定量分析。基于7种自建的减肥类食品非法添加物数据库,在青梅中检出1种未知添加物。通过分析未知添加物的分子离子峰、二级质谱碎片离子信息及同位素信息,结合密度泛函理论,并经过标准品验证,确认其为新型非法添加物4-氯双醋酚丁。通过优化样品提取溶剂和流动相溶液,考察了8种非法添加物的检出限、定量限、线性范围、回收率、相对标准偏差和基质效应。结果表明,脱乙酰比沙可啶和比沙可啶的检出限为0.001 mg/kg、定量限为0.005 mg/kg,其余6种化合物的检出限为0.05 mg/kg、定量限为0.1 mg/kg,线性相关系数(R^(2))不低于0.999,所有化合物均表现为中等和弱基质效应,回收率为71.02%~103.01%,相对标准偏差为0.87%~13.24%。将该方法应用于减肥类食品青梅和果冻的快速筛查中,30%青梅检出4-氯双醋酚丁。本方法适用于减肥类食品中非法添加物的快速定性、定量分析,可在潜在风险物识别方面发挥作用。

关键词：减肥食品非法添加物超高效液相色谱-四极杆/静电场轨道阱质谱(UHPLC-Q/Orbitrap MS) 可疑物筛查

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