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The contribution of photoinduced charge-transfer enhancement to the SERS of uranyl(VI)in a uranyl-Ag2O complex
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作者 Shaofei Wang Shanli Yang +7 位作者 Haoxi Wu Jiaolai Jiang Lang Shao Yiming Ren Yingru Li Chuanhui Liang Mingfu Chu Xiaolin Wang 《科学通报:英文版》 SCIE EI CSCD 2019年第5期315-320,共6页
Charge-transfer(CT)is an important enhancement mechanism in the field of surface-enhanced Raman scattering(SERS)that typically increases the Raman intensity of molecules by as much as 10–100 times.Herein,a low-cost A... Charge-transfer(CT)is an important enhancement mechanism in the field of surface-enhanced Raman scattering(SERS)that typically increases the Raman intensity of molecules by as much as 10–100 times.Herein,a low-cost Ag2O aggregates substrate was prepared via a facile chemical precipitation method,and the calculated CT-based enhancement factor of the uranyl ions adsorbed on it reached as high as 105,a metal-comparable value.The efficient photoinduced CT process from the valence band of Ag2O to the LUMO of uranyl ions under appropriate excitation sources resulted in the repulsion of the axial oxygen atoms of the O=U=O bond,which enhanced its polarizability,creating a more intense Raman mode.To the best of our knowledge,this study firstly reports such a strong photoinduced CT enhancement of uranyl ions,with concentrations of 10^-8 mol L^-1 or lower being detected using this Ag2O substrate.Most importantly,this research has shown that the photoinduced CT enhancement also contributes to the SERS of uranyl ions on pure Ag substrates which have often been ascribed to the electromagnetic enhancement in previous studies.In addition,Ag2O can be used to selectively detect uranyl ions without interference from many other molecules or ions because of the energy matching rule of the photoinduced CT process,which was readily available for uranyl detection in the environmental aqueous solution. 展开更多
关键词 PHOTOINDUCED CHARGE-TRANSFER URANYL SERS AG2O AGGREGATES Trace analysis
低压均质处理对大豆分离蛋白凝胶特性的影响
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作者 吕博 李明达 +3 位作者 张毅方 李杨 江连洲 刘军 《食品工业》 CAS 北大核心 2019年第2期168-172,共5页
通过测定凝胶的持水性、黏性、巯基含量,运用扫描电子显微镜、质构测定等方法分析探讨了低压均质处理(0~40 MPa)对大豆分离蛋白(Soy protein isolate)凝胶特性和结构的影响。结果表明,随着均质压力的增大,大豆分离蛋白内部疏水基团暴露... 通过测定凝胶的持水性、黏性、巯基含量,运用扫描电子显微镜、质构测定等方法分析探讨了低压均质处理(0~40 MPa)对大豆分离蛋白(Soy protein isolate)凝胶特性和结构的影响。结果表明,随着均质压力的增大,大豆分离蛋白内部疏水基团暴露,分子结构逐渐展开,当均质压力达到20 MPa时,疏水相互作用促进了凝胶网状结构的形成,有效提高了凝胶的弹性、回复性、黏性。扫描电子显微镜结果表明,当均质压力达到20 MPa时,凝胶结构规律,致密有序;当压力进一步增大时,产生的不溶性聚集体破坏了凝胶的网状结构,产生不均匀的空穴,立体感差。 展开更多
关键词 大豆分离蛋白 低压均质 凝胶性 聚集
Soil organic carbon associated with aggregate-size and density fractions in a Mollisol amended with charred and uncharred maize straw 预览
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作者 GUAN Song LIU Si-jia +4 位作者 LIU Ri-yue ZHANG Jin-jing REN Jun CAI Hong-guang LIN Xin-xin 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第7期1496-1507,共12页
Straw return has been strongly recommended in China,whereas applying biochar into soil is considered to provide more benefits for agriculture as well as the environment.In this study,a five-year(2011-2015) field exper... Straw return has been strongly recommended in China,whereas applying biochar into soil is considered to provide more benefits for agriculture as well as the environment.In this study,a five-year(2011-2015) field experiment was conducted to evaluate the effects of uncharred maize straw amendment(MS) and charred maize straw amendment(charred MS) on organic carbon(C) contents in bulk soil and in various soil aggregate-size and density fractions.Compared to no amendment(CK),the bulk soil organic C content significantly improved by 9.30% for MS and by 23.4% for charred MS.Uncharred and charred maize straw applied annually at a consistent equal-C dosage resulted in 19.7 and 58.2% organic C sequestration efficiency in soil,respectively,after the five years of the field experiment.The percentages of macroaggregates(>0.25 mm) and occluded microaggregates(0.25-0.053 mm) obviously increased by 7.73 and 18.1% for MS and by 10.7 and 19.6% for charred MS,respectively.Moreover,significant incremental increases of 19.4 and 35.0% in macroaggregate-associated organic C occurred in MS and charred MS,respectively.The occluded microaggregates associated organic C significantly increased by 21.7% for MS and 25.1% for charred MS.Mineral-associated organic C(<0.053 mm) inside the macroaggregates and the occluded microaggregates obviously improved by 24.7 and 33.3% for MS and by 18.4 and 44.9% for charred MS.Organic C associated with coarse particulate organic matter(POM) within the macroaggregates markedly increased by 65.1 and 41.2% for MS and charred MS,respectively.Charred MS resulted in a noteworthy increment of 50.4% for organic C associated with heavy POM inside the occluded microaggregates,whereas charred MS and MS observably improved organic C associated with heavy POM inside the free microaggregates by 36.3 and 20.0%,respectively.These results demonstrate that uncharred and charred maize straw amendments improve C sequestration by physically protecting more organic C in the macroaggregates and the occluded microaggregates.Compa 展开更多
关键词 SOIL organic carbon SOIL aggregates DENSITY FRACTIONATION maize STRAW BIOCHAR
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Development of a sample preparation approach to measure the size of nanoparticle aggregates by electron microscopy
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作者 Agnieszka Dudkiewicz Angela Lehner +6 位作者 Qasim Chaudhry Kristian Molhave Guenter Allmaier Karen Tiede Alistair B.A. Boxall Peter Hofmann John Lewis 《颗粒学报:英文版》 SCIE EI CAS CSCD 2019年第4期49-57,共9页
Electron microscopy (EM) is widely used for nanoparticle (NP) sizing. Following an initial assessment of two sample preparation protocols described in the current literature as"unperturbed", we found that ne... Electron microscopy (EM) is widely used for nanoparticle (NP) sizing. Following an initial assessment of two sample preparation protocols described in the current literature as"unperturbed", we found that neither could accurately measure the size of NPs featuring a broad size distribution, e.g., aggregates. Because many real-world NP samples consist of aggregates, this finding was of considerable concern. The data showed that the protocols introduced errors into the measurement by either inducing agglomeration artefacts or providing a skewed size distribution towards small particles (skewing artefact). The focus of this work was to develop and apply a mathematical refinement to correct the skewing artefact. This refinement provided a much improved agreement between EM and a reference methodology, when applied to the measurement of synthetic amorphous silica NPs. Further investigation, highlighted the influence of NP chemistry on the refinement. This study emphasised the urgent need for greater and more detailed consideration regarding the sample preparation of NP aggregates to routinely achieve accurate measurements by EM. This study also provided a novel refinement solution applicable to the size characterisation of silica and c让rate-coated gold NPs featuring broad size distributions. With further research, this approach could be extended to other NP types. 展开更多
关键词 NANOPARTICLES AGGREGATES Measurement Electron MICROSCOPY SAMPLE preparation Artefacts
Punching shear behavior of recycled aggregate concrete slabs with and without steel fibres
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作者 Jianzhuang XIAO Wan WANG +1 位作者 Zhengjiu ZHOU Mathews M.TAWANA 《结构与土木工程前沿:英文版》 EI CSCD 2019年第3期725-740,共16页
A study on the punching shear behavior of 8 slabs with recycled aggregate concrete(RAC)was carried out.The two main factors considered were the recycled coarse aggregate(RCA)replacement percentage and the steel fibre ... A study on the punching shear behavior of 8 slabs with recycled aggregate concrete(RAC)was carried out.The two main factors considered were the recycled coarse aggregate(RCA)replacement percentage and the steel fibre volumetric ratio.The failure pattern,load-displacement curves,energy consumption,and the punching shear capacity of the slabs were intensively investigated.It was concluded that the punching shear capacity,ductility and energy consumption decreased with the increase of RCA replacement percentage.Research findings indicated that the incorporation of steel fibres could not only improve the energy dissipation capacity and the punching shear capacity of the slab,but also effectively improve the integrity of the slab tension surface and thereby changing the trend from typical punching failure pattern to bending-punching failure pattern.On the basis of the test,the punching shear capacity formula of RAC slabs with and without steel fibres was proposed and discussed. 展开更多
关键词 recycled AGGREGATE concrete steel fibres SLAB PUNCHING shear recycled coarse AGGREGATES REPLACEMENT PERCENTAGE
餐厨垃圾制备的外源有机碳对土壤团聚体的影响 预览
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作者 王越 刘东明 +4 位作者 侯佳奇 郝艳 孟繁华 李鸣晓 樊华 《环境科学研究》 EI CAS CSCD 北大核心 2019年第1期166-173,共8页
为了阐明外源有机碳对土壤碳库的作用机制,以餐厨垃圾为原料,制备了4种不同分子量级的外源有机碳,通过室内试验,研究了外源有机碳对土壤有机碳组分及土壤团聚体的影响.结果表明:①以分子量≤1ku为主的小分子有机碳处理组土壤中w(DOC)(DO... 为了阐明外源有机碳对土壤碳库的作用机制,以餐厨垃圾为原料,制备了4种不同分子量级的外源有机碳,通过室内试验,研究了外源有机碳对土壤有机碳组分及土壤团聚体的影响.结果表明:①以分子量≤1ku为主的小分子有机碳处理组土壤中w(DOC)(DOC为水溶性有机碳)比CK组增加了0.383g/kg,CO2累积释放量达到(6.595±0.259)mg/kg(以C计);微生物活性增强,>5mm水稳大团聚体质量分数相对于CK组提升了25.06%,表明小分子有机碳增强了土壤微生物活性,微生物通过菌根网络缠绕作用促进大团聚体形成,增强土壤团聚体稳定性.②以分子量≥5ku的大分子有机碳为主的大分子有机碳处理组w(POC)(POC为颗粒态有机碳)为CK组的5.65倍,0.5~1mm水稳大团聚体质量分数增加了10.84%,有机碳贡献率提升了14.79%,表明大分子有机碳通过增加土壤中w(POC),促进0.5~1mm水稳大团聚体形成,提高团聚体有机碳贡献率.研究显示,不同分子量级外源有机碳通过不同的方式改善土壤团聚体结构进而促进土壤有机碳固定,餐厨垃圾生物强化有机肥中各量级有机碳比例合理,能够明显提升土壤有机碳水平,增加土壤团聚体稳定性. 展开更多
关键词 外源有机碳 小分子有机碳 大分子有机碳 土壤活性有机碳组分 团聚体
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Transcriptional dysregulation in neurodegenerative diseases:who tipped the balance of Yin Yang 1 in the brain? 预览
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作者 Zhefan Stephen Chen Ho Yin Edwin Chan 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第7期1148-1151,共4页
Yin Yang 1(YY1)is a multi-functional transcription factor that regulates gene expression in a range of cell types,including neurons.It controls neuronal differentiation,as well as neuronal specification and migration ... Yin Yang 1(YY1)is a multi-functional transcription factor that regulates gene expression in a range of cell types,including neurons.It controls neuronal differentiation,as well as neuronal specification and migration during the development of the mammalian nervous system.Besides,YY1 also mediates the transcription of genes that are required for neuronal survival.An impairment of the transcriptional function of YY1 causes neuronal death.This review summarizes recent research findings that unveil the dysfunction of YY1 in multiple neurodegenerative disorders.The expression of disease proteins perturbs the function of YY1 via distinct molecular mechanisms,including recruitment to protein aggregates,protein degradation and aberrant nuclear/cytoplasmic shuttling.Understanding the pathogenic roles of YY1 will further broaden our knowledge of the disease mechanisms in distinct neurodegenerative disorders. 展开更多
关键词 Alzheimer’s disease amyotrophic lateral SCLEROSIS neurodegeneration PROTEIN aggregates recruitment PROTEIN degradation SUBCELLULAR localization TRANSCRIPTIONAL regulation YIN Yang 1
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Evaluation of the mechanical degradation of carbonate aggregate by rock strength tests 预览
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作者 Mojtaba Kamani Rassoul Ajalloeian 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期121-134,共14页
Aggregate degradation(AD)is one of the major reasons accounting for failure of aggregate materials,and the mechanical degradation of aggregate materials can be determined by different test methods.This process basical... Aggregate degradation(AD)is one of the major reasons accounting for failure of aggregate materials,and the mechanical degradation of aggregate materials can be determined by different test methods.This process basically requires many aggregate samples and special instruments,and thus is time-consuming.The main purpose of this research is to evaluate the possibility of estimating the AD characteristics using rock strength tests and to investigate the relationships between AD properties and rock strength tests.For understanding the relationships,two common rock strength tests are employed,i.e.unconfined compressive strength(UCS)and point load index(PLI)tests.In the tests,the AD properties of 40 kinds of carbonate aggregates sampled from Iran were studied.The AD properties were determined by Los Angeles abrasion value(LAAV),aggregate impact value(AIV)and aggregate crushing value(ACV).Also,the samples are classified according to the strength and rock types,and the effect of this classification is investigated based on the relationship between rock strengths and AD properties.The results indicate that the PLI is better than UCS for evaluation of AD properties.Among rock strength tests,PLI has a closer relationship with AIV(R^2=0.832).Also,UCS has relative larger effects on the ACV(R^2=0.812)under the same loading condition.The weakest correlation occurs between LAAV and UCS(R^2=0.679).In view of the rational AD properties in the predictive procedure,it is possible to predict AD properties based on the strength tests and rock types.The results also show that the prediction of AD properties using rock strength test based on rock types yields better correlations than that using unclassified samples.The classification based on rock types can extrapolate the different relationships of AD prediction from rock strength tests.The results in this context could be used for preliminarily selecting proper rock aggregates with a limit of allowable AD tests for practical applications by PLI. 展开更多
关键词 AGGREGATE DEGRADATION Unconfined COMPRESSIVE strength Point LOAD index CARBONATE AGGREGATES
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混凝土细观破坏过程的近场动力学模拟 预览
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作者 郭士强 夏晓舟 +1 位作者 顾鑫 章青 《河南科学》 2019年第7期1122-1128,共7页
近场动力学(Peridynamic,PD)是一种基于非局部作用思想的理论,解决不连续问题时具有独特优势.首先概述了常规态型PD基本理论(Ordinary State-Based PD,OSB PD),采用了一种新的圆形骨料投放方法,有效地提高了混凝土骨料的投放率,建立了... 近场动力学(Peridynamic,PD)是一种基于非局部作用思想的理论,解决不连续问题时具有独特优势.首先概述了常规态型PD基本理论(Ordinary State-Based PD,OSB PD),采用了一种新的圆形骨料投放方法,有效地提高了混凝土骨料的投放率,建立了适用于混凝土细观破坏的常规态型PD计算模型.对混凝土结构的细观破坏过程进行了模拟,数值模拟结果与理论解吻合较好,进而分析了混凝土结构细观破坏机理. 展开更多
关键词 近场动力学 混凝土 细观破坏 数值模拟 骨料
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秸秆还田对盐渍土团聚体稳定性及碳氮含量的影响 预览
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作者 王会 何伟 +4 位作者 段福建 胡国庆 娄燕宏 宋付朋 诸葛玉平 《农业工程学报》 EI CAS CSCD 北大核心 2019年第4期124-131,共8页
以黄河三角洲典型盐化潮土为研究对象,分析了3种盐渍化程度(轻度、中度、重度)和3a连续秸秆还田下土壤水稳性团聚体组成、稳定性以及各级团聚体C、N含量的变化。研究结果表明:重度盐渍土0.25~2mm和0.053~0.25mm团聚体所占比例显著低于... 以黄河三角洲典型盐化潮土为研究对象,分析了3种盐渍化程度(轻度、中度、重度)和3a连续秸秆还田下土壤水稳性团聚体组成、稳定性以及各级团聚体C、N含量的变化。研究结果表明:重度盐渍土0.25~2mm和0.053~0.25mm团聚体所占比例显著低于轻度和中度盐渍土;土壤盐分含量与0.25~2mm团聚体中有机碳和全氮的分配比例、0.053~0.25mm团聚体中全氮的分配比例成显著负相关。秸秆还田使轻度盐渍土平均重量直径(MWD)、几何平均直径(GMD)和>0.25mm团聚体所占比例(R0.25)分别增加47.6%、39.7%和54.0%,使中度盐渍土MWD、GMD和R0.25分别增加31.0%、31.9%和31.4%;各粒级中秸秆还田使轻度盐渍土0.053~0.25mm粒级有机碳和全氮含量增加最多,增加比例分别为29.1%和28.8%,该粒级中C、N分配比例也显著提高;秸秆还田使中度盐渍土0.25~2mm团聚体有机碳及其分配比例提高最多,比例分别为56.1%和58.7%。秸秆还田对轻度和中度盐渍土团聚体的稳定性均起到了明显的改善作用,但不同盐渍土秸秆还田对土壤团聚体C、N分布的影响明显不同。 展开更多
关键词 土壤 有机碳 团聚体 秸秆 全氮 盐化潮土
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基于RSM-BBD的混合骨料充填料浆配比优化 预览
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作者 高谦 杨晓炳 +2 位作者 温震江 陈得信 何建元 《湖南大学学报:自然科学版》 EI CAS CSCD 北大核心 2019年第6期47-55,共9页
针对混合骨料充填矿山,为了确定充填料浆优化配比,首先进行充填材料物化特性分析,在此基础上,根据泰波级配理论和最大堆积密实度理论,确定棒磨砂-废石配比;然后采用BBD响应面法设计13组试验,研究料浆质量分数、胶砂比(胶凝材料与骨料的... 针对混合骨料充填矿山,为了确定充填料浆优化配比,首先进行充填材料物化特性分析,在此基础上,根据泰波级配理论和最大堆积密实度理论,确定棒磨砂-废石配比;然后采用BBD响应面法设计13组试验,研究料浆质量分数、胶砂比(胶凝材料与骨料的比值)、混合骨料配比对充填体强度影响规律.最后以各龄期强度为响应值构建响应面模型,揭示各响应参数与目标响应量相关关系及多目标条件下充填料浆优化配比.研究结果表明,充填体强度不仅受单因素影响,而且各因素间交互作用对充填体也有很大影响.其中料浆质量分数与骨料配比的交互作用对充填体早期强度起决定性作用,胶砂比与骨料配比的交互作用对充填体中期强度影响显著,充填体后期强度受料浆质量分数和胶砂比交互作用影响较大.以充填成本作为目标建立优化模型进行优化,由此获得充填料浆的优化配比为:料浆质量分数80%,胶砂比为1∶6,棒磨砂-废石配比为3∶7.通过试验验证满足金川矿山充填体强度要求. 展开更多
关键词 采矿方法 BBD响应面法 料浆配比 骨料 抗压强度 交互作用 多目标优化 成本
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生物炭对日光大棚土壤团聚体结构的影响 预览
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作者 王亚琼 牛文全 +3 位作者 李学凯 王婕 官雅辉 董继红 《水土保持通报》 CSCD 北大核心 2019年第4期190-195,共6页
[目的]探明果木生物炭对杨凌地区日光大棚土壤团聚体结构的影响,提出适宜该地区的生物炭添加量,为改良日光温室大棚土壤结构,提升作物产量提供科学依据。[方法]设置10,30,50,70,90 t/hm^2共5个生物炭添加量处理,以未添加生物炭处理为对... [目的]探明果木生物炭对杨凌地区日光大棚土壤团聚体结构的影响,提出适宜该地区的生物炭添加量,为改良日光温室大棚土壤结构,提升作物产量提供科学依据。[方法]设置10,30,50,70,90 t/hm^2共5个生物炭添加量处理,以未添加生物炭处理为对照,采用干筛法和湿筛法,对比分析不同处理的团聚体几何平均直径、平均重量直径、破坏率和分形维数等指标。最后通过分析不同生物炭添加量下的作物产量,综合考虑土壤团聚体指标,提出最优的生物炭添加量。[结果]添加生物炭后,土壤机械稳定性大团聚体含量增加0.6~4.6 mg/kg,机械稳定性微团聚体含量降低4.0%~32.6%;添加生物炭后,粒径为3~2 mm,2~1 mm,1~0.5 mm水稳性大团聚体含量分别增加25.3%~41.2%,22.7%~74.2%,9.1%~46.4%,粒径为0.5~0.25 mm水稳性大团聚体含量降低2.1%~18.1%。生物炭能够促进小粒径微团聚体的形成,但对微团聚体稳定性和总含量没有显著影响。添加生物炭后菠菜鲜重显著提升(68.7%~214.9%)。[结论]生物炭能够改良土壤团聚体结构。综合考虑团聚体、作物产量因素,在日光大棚添加70 t/hm^2生物炭效果最好。 展开更多
关键词 生物炭 团聚体 稳定性 植株鲜重
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缙云山4种森林植被土壤团聚体有机碳分布特征
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作者 王富华 吕盛 +3 位作者 黄容 高明 王子芳 徐畅 《环境科学》 EI CAS CSCD 北大核心 2019年第3期1504-1511,共8页
以重庆市缙云山的竹林、阔叶林、针叶林和针阔叶混交林这4种亚热带森林植被为研究对象,分析不同林分下土壤团聚体及团聚体有机碳在0~20、20~40、40~60和60~100 cm土壤剖面上的分布规律.结果表明,阔叶林土壤> 2 mm粒级团聚体含量、平... 以重庆市缙云山的竹林、阔叶林、针叶林和针阔叶混交林这4种亚热带森林植被为研究对象,分析不同林分下土壤团聚体及团聚体有机碳在0~20、20~40、40~60和60~100 cm土壤剖面上的分布规律.结果表明,阔叶林土壤> 2 mm粒级团聚体含量、平均重量直径(MWD)、几何平均直径(GMD)及> 0. 25 mm团聚体含量(R0. 25)均随土层深度的增加而降低,而其他林分在整个土层中则无明显规律.在各土层中,竹林以> 2 mm粒级团聚体为主(30. 73%~53. 08%);阔叶林和混交林的2~0. 25 mm粒级团聚体含量较高,为36. 27%~44. 67%和48. 69%~52. 44%;针叶林的优势粒径为2~0. 25 mm和<0. 053 mm.总体上,在各土层中,竹林团聚体的MWD、GMD、R0. 25值均高于其他林分,且其分形维数(D)低于其他林分,可见竹林的土壤团聚体稳定性较好.随着土层深度的增加,不同林分(除针叶林外)土壤团聚体有机碳含量逐渐降低,其中竹林团聚体有机碳含量最高,显著高于针叶林和混交林.就不同团聚体粒级而言,4种林分土壤团聚体有机碳在整个土壤剖面上无明显规律,但各土层均以2~0. 25 mm和<0. 053 mm粒级团聚体有机碳含量较高.不同林分下土壤团聚体有机碳相对贡献率存在显著差异,其中针叶林中<0. 053 mm粒级团聚体有机碳贡献率最高;竹林的> 2 mm粒级团聚体有机碳贡献率高达27. 44%~53. 47%;而阔叶林和混交林则以2~0. 25 mm粒级团聚体有机碳贡献率最高.缙云山的4种林分中,竹林的土壤团聚体稳定性较好,而针叶林的较差;在各土层中,竹林土壤各粒级团聚体有机碳含量最高,针叶林最低. 展开更多
关键词 缙云山 林分类型 有机碳 团聚体 稳定性
一株耐盐碱细菌的筛选及其在赤泥改良中的应用
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作者 宋建 王帝伟 +4 位作者 张晓晶 李志辉 杨志辉 邱坤艳 王洋洋 《河南大学学报:自然科学版》 CAS 2019年第1期26-35,共10页
从赤泥堆场筛选出一株可高效降低环境pH的耐盐碱细菌ZH-22,经16SrRNA基因测序鉴定为芽孢杆菌属(Bacillus).对ZH-22产酸条件进行优化分析,确定ZH-22的最优产酸条件,探明ZH-22的产酸种类及各自浓度.在最优产酸条件下将ZH-22投加到赤泥中,... 从赤泥堆场筛选出一株可高效降低环境pH的耐盐碱细菌ZH-22,经16SrRNA基因测序鉴定为芽孢杆菌属(Bacillus).对ZH-22产酸条件进行优化分析,确定ZH-22的最优产酸条件,探明ZH-22的产酸种类及各自浓度.在最优产酸条件下将ZH-22投加到赤泥中,研究ZH-22对赤泥的改良效果及其在赤泥中的生长情况.结果表明,ZH-22最优产酸条件为:葡萄糖5g/L,酵母膏4g/L,磷酸二氢钾0.3g/L,氯化镁0.3g/L;在静置培养条件下,ZH-22产生的有机酸以草酸为主;振荡培养条件下,则以酒石酸为主,且振荡培养条件下产酸速度及浓度均大于静置培养.将ZH-22加入赤泥后,赤泥pH可从11.53降低至9.3左右,并可较长时间保持在9.3左右;同时赤泥的大粒径团聚体明显增多,团聚体稳定性提升明显,赤泥物理结构得到显著改善.群落分析显示,ZH-22能够快速适应赤泥环境且能在赤泥中快速生长,随着时间的推移丰度不断增加. 展开更多
关键词 赤泥改良 耐盐碱菌株 16S RRNA 有机酸 团聚体
Properties of coarse particles in suspended particulate matter of the North Yellow Sea during summer 预览
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作者 ZHANG Kainan WANG Zhenyan +1 位作者 LI Wenjian YAN Jun 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第1期79-92,共14页
Fine particles in seawater commonly form large porous aggregates.Aggregate density and settling velocity determine the behavior of this suspended particulate matter(SPM)within the water column.However,few studies of a... Fine particles in seawater commonly form large porous aggregates.Aggregate density and settling velocity determine the behavior of this suspended particulate matter(SPM)within the water column.However,few studies of aggregate particles over a continental shelf have been undertaken.In our case study,properties of aggregate particles,including size and composition,over the continental shelf of the North Yellow Sea were investigated.During a scientifi c cruise in July 2016,in situ eff ective particle size distributions of SPM at 10 stations were measured,while temperature and turbidity measurements and samples of water were obtained from surface,middle,and bottom layers.Dispersed and inorganic particle size distributions were determined in the laboratory.The in situ SPM was divided into(1)small particles(<32μm),(2)medium particles(32–256μm)and(3)large particles( >256μm).Large particles and medium particles dominated the total volume concentrations(VCs)of in situ SPM.After dispersion,the VCs of medium particles decreased to low values(<0.1μL/L).The VCs of large particles in the surface and middle layers also decreased markedly,although they had higher peak values(0.1–1μL/L).This suggests that almost all in situ medium particles and some large particles were aggregated,while other large particles were single particles.Correlation analysis showed that primary particles<32μm infl uenced the formation of these aggregates.Microscopic examination revealed that these aggregates consisted of both organic and inorganic fi ne particles,while large particles were mucus-bound organic aggregates or individual plankton.The vertical distribution of coarser particles was clearly related to water stratifi cation.Generally,medium aggregate particles were dominant in SPM of the bottom layer.A thermocline blocked resuspension of fi ne material into upper layers,yielding low VCs of medium-sized aggregate particles in the surface layer.Abundant large biogenic particles were present in both surface and middle layers. 展开更多
关键词 suspended PARTICULATE matter(SPM) coarse particles aggregates North Yellow Sea laser in SITU SCATTERING and transmissometery(LISST)
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施肥对采煤塌陷复垦土壤团聚体组成及其碳、氮分布的影响 预览
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作者 梁利宝 冯鹏艳 许剑敏 《灌溉排水学报》 CSCD 北大核心 2019年第7期45-51,共7页
【目的】研究施肥对采煤塌陷复垦土壤团聚体组成及其碳、氮分布的影响,为改善采煤塌陷复垦土壤的物理团粒结构与化学性质,促进复垦土壤碳氮循环与利用提供一定理论基础。【方法】以山西省晋城市采煤塌陷复垦区土壤为研究对象,在常规灌... 【目的】研究施肥对采煤塌陷复垦土壤团聚体组成及其碳、氮分布的影响,为改善采煤塌陷复垦土壤的物理团粒结构与化学性质,促进复垦土壤碳氮循环与利用提供一定理论基础。【方法】以山西省晋城市采煤塌陷复垦区土壤为研究对象,在常规灌溉条件下,以不施肥处理为对照(CK),研究了有机肥、无机肥、有机无机肥配施3种施肥处理对0~20、20~40cm土层团聚体组成及碳、氮分布的影响。【结果】与CK相比,有机肥处理显著增加了土壤>2mm和1~2mm粒级团聚体量,降低了0.053~0.25mm和<0.053mm粒级微团聚体量,单施化肥较有机肥处理提高了微团聚体量。单施有机肥、有机无机肥配施处理土壤的平均质量直径(MWD)、几何平均直径(GMD)显著高于单施化肥处理,分形维数(D)低于化肥处理。有机肥处理土壤有机碳、全氮量最高,有机无机肥处理配施次之,单施化肥处理显著低于有机肥处理;土壤有机碳、全氮主要分布在>2mm、1~2mm、0.25~1mm粒级大团聚体,显著高于0.053~0.25mm、<0.053mm粒级小团聚体;有机肥处理、有机无机肥配施处理土壤>2mm、1~2mm、0.25~1mm粒级团聚体中的有机碳、全氮量要显著高于单施无机肥处理的。各施肥处理土壤1~2mm、0.25~1mm粒级团聚体有机碳、全氮贡献率较高,显著高于其余粒级。有机肥、有机无机配施处理各级团聚体(除0.053~0.25mm外)的C/N值显著高于CK,而单施化肥处理与CK差异不显著。【结论】不同施肥处理(尤其是有机肥)提高了复垦土壤大团聚体量,增强了团聚体稳定性,提高了团聚体有机碳、全氮量。 展开更多
关键词 采煤塌陷 复垦土壤 施肥 团聚体 有机碳 全氮 常规灌溉
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Solvothermal synthesis of nano-CeO2 aggregates and its application as a high-efficient arsenic adsorbent
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作者 Jing-Hua Pang Ying Liu +1 位作者 Jun Li Xiao-Jiao Yang 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第1期73-80,共8页
Aggregates of cerium dioxide nanoparticles(nano-CeO2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO2 were system... Aggregates of cerium dioxide nanoparticles(nano-CeO2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO2 were systematically studied by X-ray diffraction(XRD),transmission electron microscopy(TEM), laser particle size analyzer(LA) and specific surface area and pore size analyzer during the solvothermal process. Among all the obtained samples, the 18-h solvothermal-prepared nano-CeO2 aggregates show the best crystallinity and the largest specific surface area of 110.92 m2·g^-1. Owing to the high activity derived from the high specific surface area of the aggregates, the application as arsenic(As) adsorption was also studied. The adsorption efficiency of arsenic by nano-CeO2 aggregates was established as the function of adsorbent dose, then pH value and at last adsorption time.The results indicate that the nano-CeO2 aggregates show a high efficiency in removing arsenic from low As concentration solution, from which the nano-CeO2 adsorbent could be easily separated. In addition, the adsorption kinetics is best fitted to pseudo-second-order model(R^2 = 0.99999). 展开更多
关键词 NANO-CEO2 Large surface AGGREGATES SOLVOTHERMAL REMOVAL of ARSENIC
Long-Term Effects of Different Passages of Vehicular Traffic on Soil Properties and Carbon Storage of a Crosby Silt Loam in USA
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作者 Gulab Singh YADAV Rattan LAL +1 位作者 Ram Swaroop MEENA Basant RIMAL 《土壤圈:英文版》 SCIE CAS CSCD 2019年第2期150-160,共11页
The passage of vehicles with heavy axle loads causes soil compaction, and this adversely affects soil properties and crop yield.The adverse effects can persist for several years due to significant changes in key soil ... The passage of vehicles with heavy axle loads causes soil compaction, and this adversely affects soil properties and crop yield.The adverse effects can persist for several years due to significant changes in key soil properties. However, the mechanisms of the aforementioned effects are not well understood for conservation agriculture(CA)(e.g., no-till(NT)) wherein the use of heavy machinery is considerably common. Therefore, known compaction forces(0 Mg load for compaction(NT-0, control), two passages of 2.5 Mg water wagon axle load(NT-2), and four passages of 2.5 Mg water wagon axle load(NT-4)) were applied to all the plots annually for 20 consecutive years. The experiment was established in 1997 at the Waterman Agricultural and Natural Resources Laboratory(WANRL), Ohio State University, Columbus, Ohio. Each treatment was replicated thrice. Soil samples were obtained in November2016 to determine the effects of variations in the axle load and vehicular passages on carbon(C) and nitrogen(N) storage and selected soil properties of a Crosby silt loam soil under NT-based corn-soybean rotation with residue retention in Central Ohio, USA. Three locations were also randomly selected in an adjoining natural woodlot(WL) soil plot and sampled(30 m away from the compaction field) to compare the effects of vehicular traffic on soil under NT with WL soil. Results revealed that soil bulk density(ρb) and total porosity at 0–10 and 10–20 cm depths were not affected by the passages of vehicular traffic for 20 years under the NT system.The penetration resistance(PR)(1.86 and 2.03 MPa at 0–10 and 10–20 cm soil depths, respectively) was significantly higher under NT-4 compared with that under other treatments. Saturated hydraulic conductivity at 0–10 and 10–20 cm soil depths ranged from19.7 to 31.4 and 18.5 to 29.5 mm d-1, respectively, across all the treatments. The proportion of macroaggregates(> 0.25 mm) and microaggregates(< 0.25 mm), mean weight diameter and geometric mean diameter of aggregates, pH, electrical con 展开更多
关键词 carbon stock heavy machinery NO-TILL residue retention SOIL aggregates SOIL COMPACTION SOIL quality well-drained SOIL
Distribution of soil aggregates and organic carbon in deep soil under long-term conservation tillage with residual retention in dryland
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作者 WANG Bisheng GAO Lili +7 位作者 YU Weishui WEI Xueqin LI Jing LI Shengping SONG Xiaojun LIANG Guopeng CAI Dianxiong WU Xueping 《干旱区科学:英文版》 SCIE CSCD 2019年第2期241-254,共14页
To ascertain the effects of long-term conservation tillage and residue retention on soil organic carbon(SOC) content and aggregate distribution in a deep soil(>20-cm depth) in a dryland environment,this paper analy... To ascertain the effects of long-term conservation tillage and residue retention on soil organic carbon(SOC) content and aggregate distribution in a deep soil(>20-cm depth) in a dryland environment,this paper analyzed the SOC and aggregate distribution in soil, and the aggregate-associated organic carbon(OC) and SOC physical fractions. Conservation tillage(reduced tillage with residue incorporated(RT) and no-tillage with residue mulch(NT)) significantly increased SOC sequestration and soil aggregation in deep soil compared with conventional tillage with residue removal(CT). Compared with CT, RT significantly increased the proportion of small macroaggregates by 23%–81% in the 10–80 cm layer, and the OC content in small macroaggregates by 1%–58% in the 0–80 cm layer. RT significantly increased(by 24%–90%) the OC content in mineral-SOC within small macroaggregates in the 0–60 cm layer, while there was a 23%–80% increase in the 0–40 cm layer with NT. These results indicated that:(1) conservation tillage treatments are beneficial for soil aggregation and SOC sequestration in a deep soil in a dryland environment;and(2)the SOC in mineral-associated OC plays important roles in soil aggregation and SOC sequestration. In conclusion, RT with NT is recommended as an agricultural management tool in dryland soils because of its role in improving soil aggregation and SOC sequestration. 展开更多
关键词 LONG-TERM TILLAGE residue RETENTION SOIL aggregates SOC deep SOIL DRYLAND
棉粕对不同类型盐渍化土壤团聚体中碳氮含量的影响 预览
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作者 孟春梅 王开勇 +2 位作者 张开祥 马宏秀 李宗飞 《江苏农业学报》 CSCD 北大核心 2019年第2期307-312,共6页
盐渍化导致土壤中养分流失、土壤结构被破坏,是阻碍新疆绿洲农业向前发展的一个主要原因。本研究采用田间试验和室内分析相结合的方法,研究棉粕对不同类型盐渍化(NaCl盐渍化、Na2CO3盐渍化)土壤团聚体碳氮含量的影响,并通过测定土壤中... 盐渍化导致土壤中养分流失、土壤结构被破坏,是阻碍新疆绿洲农业向前发展的一个主要原因。本研究采用田间试验和室内分析相结合的方法,研究棉粕对不同类型盐渍化(NaCl盐渍化、Na2CO3盐渍化)土壤团聚体碳氮含量的影响,并通过测定土壤中各粒级团聚体中碳氮含量探究其变化。结果表明:小粒级团聚体(<0.25mm、0.25~2.00mm)中有机碳含量高于大粒级(2.01~5.00mm)团聚体中碳含量,全氮含量则相反。两种盐渍化土壤施入棉粕后可以减少2.01~5.00mm大粒级团聚体比例,增加小粒级团聚体比例,不同含量氯化钠盐渍化+棉粕处理的土壤团聚体中碳氮含量增加幅度大于不同含量碳酸钠盐渍化+棉粕处理,小粒级团聚体中有机碳含量和大粒级团聚体中全氮含量是影响盐渍化壤养分的主要因子。 展开更多
关键词 棉粕 盐渍化土壤 碳氮含量 团聚体
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