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Invasive rats strengthen predation pressure on bird eggs in a South Pacific island rainforest 被引量:1
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作者 Quiterie DURON Edouard BOURGUET +2 位作者 Helene DE MERINGO Alexandre MILLON Eric VIDAL 《Current Zoology》 SCIE CAS CSCD 2017年第6期583-590,共8页
Invasive rats (Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects ... Invasive rats (Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects are undertaken on islands worldwide. However, such projects represent a huge investment and the decision-making process requires proper assessment of rat impacts. Here, we assessed the influence of two sympatric invasive rats (Rattus rattus and R. exulans) on native bird eggs in a New Caledonian rainforest, using artificial bird-nest monitoring. A total of 178 artificial nests containing two eggs of three different sizes were placed either on the ground or 1.5 m high and monitored at the start of the birds' breeding season. Overall, 12.4% of the nests were depredated during the first 7 days. At site 1, where nests were monitored during 16 days, 41.8% of the nests were depredated. The main predator was the native crow Corvus moneduloides, responsible for 62.9% of the overall predation events. Rats were responsible for only 22.9% of the events, and ate only small and medium eggs at both heights. Our experiment suggests that in New Caledonia, predation pressure by rats strengthens overall bird-nest predation, adding to that by native predators, Experimental rat control operations may allow reduced predation pressure on nests as well as the recording of biodiversity responses after rat population reduction. 展开更多
关键词 bird-nest predation forest birds invasive rodents island conservation rat management.
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8款市售椰奶理化指标及稳定性分析 被引量:1
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作者 胡子宁 陈俊宇 +4 位作者 单萌 朱恒伟 徐嘉泽 周婀 金颖 《饮料工业》 2025年第2期15-22,共8页
为了明确现有市售椰奶产品的品质差异,为椰奶产品开发和品质评价提供数据支持与理论指导,对8款市售椰奶产品的pH值、可溶性固形物含量、蛋白质与脂肪含量、色泽、粒度、LUMiSizer和Turbiscan稳定性、ζ-电位、流变特性等理化指标进行测... 为了明确现有市售椰奶产品的品质差异,为椰奶产品开发和品质评价提供数据支持与理论指导,对8款市售椰奶产品的pH值、可溶性固形物含量、蛋白质与脂肪含量、色泽、粒度、LUMiSizer和Turbiscan稳定性、ζ-电位、流变特性等理化指标进行测定分析。结果表明,8款椰奶为中性pH值产品,蛋白质和脂肪含量在0.58g/100mL~1.29g/100mL和2.05g/100mL~5.80g/100mL范围。椰奶色泽受蛋白质与脂肪含量、生产工艺、包装形式等影响。椰奶物理稳定性与粒径大小及分布、蛋白质与脂肪含量、乳化剂类型相关。所有椰奶产品均为剪切变稀的假塑性流体,黏度与颗粒大小有关,且均随温度升高呈现相似降低趋势。8款椰奶产品中C6产品平均粒径最小,ζ电位绝对值较大,无颗粒团聚及析油现象发生,稳定性最佳。本研究结果可为市售椰奶产品理化性质评价体系的构建和未来产品开发提供参考。 展开更多
关键词 椰奶 理化指标 稳定性 流变特性
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Modeling the Conversion of Forest Land to Other Types of Occupation Due to Urban Growth in Five Forest Towns in the Congo Basin
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作者 Stoffenne Malonga Binsangou Suspense Averti Ifo Benoit Mertens 《Open Journal of Ecology》 2025年第1期43-64,共22页
The conversion of forest land to other types of land cover is one of the major issues in the global fight against climate change. Understanding the direct and indirect factors of these conversions from local studies i... The conversion of forest land to other types of land cover is one of the major issues in the global fight against climate change. Understanding the direct and indirect factors of these conversions from local studies in the tropics is essential to project the future impact of human activities on the preservation of tropical forests in general and the forests of the Republic of Congo in particular. This study, conducted in five localities with different socioeconomic contexts in the Republic of Congo, aims to analyze the variability of drivers of deforestation and forest degradation linked to urbanization in the Congo Basin. Using a series of land cover maps from the years 1986, 2003 and 2019 for the cities of Ouesso, Pokola, Ngombe, Impfondo and Dongou, as well as field data and socio-economic information collected from local and central administrations, a unique model has been developed to understand the explanatory patterns of forest loss. Deforestation around urban centers is mainly due to urban agriculture due to population growth, as well as the spatial expansion of cities, which have a major impact on the stability and integrity of forests. Shifting agriculture is the main direct cause of deforestation and forest degradation, representing 48% of the total sample, followed by the collection of wood fuel (22%), the collection of construction wood (19%), illegal logging (6%) and urban expansion (5%). Forecasts indicate that forest loss around major cities will increase by 487, 20 ha to 5266, 73 ha by 2050 compared to the base year of 2019. This study highlights the need for a new system of land management and poverty alleviation of local populations to ensure the stability of the Congo Basin tropical forests around large and small African cities. 展开更多
关键词 DEFORESTATION Degradation MODELING Congo Basin Land Use Change LANDSAT Strong Points
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The evolution process between the earthquake swarm beneath the Noto Peninsula,central Japan and the 2024 M 7.6 Noto Hanto earthquake sequence 被引量:1
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作者 Zhigang Peng Xinglin Lei +6 位作者 Qing-Yu Wang Dun Wang Phuc Mach Dongdong Yao Aitaro Kato Kazushige Obara Michel Campillo 《Earthquake Research Advances》 2025年第1期10-21,共12页
Several physical mechanisms of earthquake nucleation,such as pre-slip,cascade triggering,aseismic slip,and fluid-driven models,have been proposed.However,it is still not clear which model plays the most important role... Several physical mechanisms of earthquake nucleation,such as pre-slip,cascade triggering,aseismic slip,and fluid-driven models,have been proposed.However,it is still not clear which model plays the most important role in driving foreshocks and mainshock nucleation for given cases.In this study,we focus on the relationship between an intensive earthquake swarm that started beneath the Noto Peninsula in Central Japan since November 2020 and the nucleation of the 2024 M 7.6 Noto Hanto earthquake.We relocate earthquakes listed in the standard Japan Meteorological Agency(JMA)catalog since 2018 with the double-different relocation method.Relocated seismicity revealed that the 2024 M 7.6 mainshock likely ruptured a thrust fault above a parallel fault where the M 6.5 Suzu earthquake occurred in May 2023.We find possible along-strike and along-dip expansion of seismicity in the first few months at the beginning of the swarm sequence,while no obvious migration pattern in the last few days before the M 7.6 mainshock was observed.Several smaller events occurred in between the M 5.5 and M 4.6 foreshocks that occurred about 4min and 2 min before the M 7.6 mainshock.The Coulomb stress changes from the M 5.5 foreshock were negative at the hypocenter of the M 7.6 mainshock,which is inconsistent with a simple cascade triggering model.Moreover,an M 5.9 foreshock was identified in the JMA catalog 14 s before the mainshock.Results from backprojection of high-frequency teleseismic P waves show a prolonged initial rupture process near the mainshock hypocenter lasting for~25 s,before propagating bilaterally outward.Our results suggest a complex evolution process linking the earthquake swarm to the nucleation of the M 7.6 mainshock at a region of complex structures associated with the bend of a mapped large-scale reverse fault.A combination of fluid migration,aseismic slip and elastic stress triggering likely work in concert to drive both the prolonged earthquake swarm and the nucleation of the M 7.6 mainshock. 展开更多
关键词 EARTHQUAKE BENEATH EVOLUTION
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Parental phenotypes and breeding performance:a review of non-experimental investigation in well-studied Western palearctic tits and flycatchers
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作者 Marcel M.Lambrechts D.Charles Deeming 《Avian Research》 2025年第4期736-753,共18页
Numerous hypotheses predict associations between phenotype-associated breeder traits and reproductive success.In secondary cavity-nesting passerine birds,which have been investigated most,up to more than 90parental ch... Numerous hypotheses predict associations between phenotype-associated breeder traits and reproductive success.In secondary cavity-nesting passerine birds,which have been investigated most,up to more than 90parental characteristics have been linked to at least one field measure of breeding performance.However,within study populations,different parental traits,such as clutch size,first-egg date,egg size,nest architecture,plumage colour,adult morphometry,or song performance,are often weakly correlated across female and/or male breeders.Furthermore,many of these studies have been conducted outside the theoretical framework of the'Individual Optimisation Hypothesis' of clutch size(IOH).IOH predicts that:(i) females with larger clutches will have larger broods at hatching and fledging compared to those with smaller clutches;and(ii) clutch size,which is adaptively adjusted to the parents' ability to rear nestlings,should always maximize the percentage of eggs producing fledglings so that variation in clutch size becomes disconnected from variation in breeding success.In this paper,we present the first detailed review of implications of IOH for parental characters other than clutch size.Our review covered 188 non-experimental studies and 1074 statistical results that examined how parental traits influence breeding success in Western Palearctic Great Tits(Parus major),Blue Tits(Cyanistes spp.),and flycatchers(Ficedula spp.).Clutch size explained one third of the variation in brood size at hatching and fledging within study populations.However,most parental characteristics associated weakly with the number of hatchlings or fledglings,likely because they did not correlate with clutch size.Overall,parental traits were poorly correlated with the proportion of hatchlings and fledglings per egg.We discuss why intraspecific variation in phenotype-associated breeder traits is often disconnected from interindividual differences in breeding success,and highlight the importance of underexplored research problems in avian breeding biology. 展开更多
关键词 Breeding success Clutch size Cyanistes FICEDULA Parental trait PARUS
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AquaVar decision support system for water resource management:Lessons learned from the first five years of operation
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作者 Fanny Picourlat Lian Guey Ler +4 位作者 Jérémy Targosz Paguedame Game HézouwéAmaou Tallé Morgan Abily Félix Billaud 《River》 2025年第1期44-54,共11页
Decision support systems(DSS)based on physically based numerical models are standard tools used by water services and utilities.However,few DSS based on holistic approaches combining distributed hydrological,hydraulic... Decision support systems(DSS)based on physically based numerical models are standard tools used by water services and utilities.However,few DSS based on holistic approaches combining distributed hydrological,hydraulic,and hydrogeological models are operationally exploited.This holistic approach was adopted for the development of the AquaVar DSS,used for water resource management in the French Mediterranean Var watershed.The year 2019 marked the initial use of the DSS in its operational environment.Over the next 5 years,multiple hydrological events allowed to test the performance of the DSS.The results show that the tool is capable of simulating peak flows associated with two extreme rainfall events(storms Alex and Aline).For a moderate flood,the real-time functionality was able to simulate forecast discharges 26 h before the flood peak,with a maximum local error of 30%.Finally,simulations for the drought period 2022-2023 highlighted the essential need for DSS to evolve in line with changing climatic conditions,which give rise to unprecedented hydrological processes.The lessons learned from these first 5 years of AquaVar use under operational conditions are synthesized,addressing various topics such as DSS modularity,evolution,data positioning,technology,and governance. 展开更多
关键词 decision support system distributed physically based models holistic approach water resource management
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Effect of Baobab (Adansonia digitata L.) Seeds Washing and Origin on Their Fatty Acids and Phenolic Compounds Oils Content
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作者 Alioune Sow Edouard Mbarick Ndiaye +9 位作者 Oumar Ibn Khatab Cissé Pape Guédel Faye Alé Kane Delphine Margout-Jantac Bou Ndiaye Samba Baldé Khadim Niane Nicolas Ayessou Patrick Poucheret Mady Cissé 《American Journal of Analytical Chemistry》 2025年第1期1-14,共14页
The aim of the present study was to evaluate the effects of baobab seed washing and origin on the chemical composition of the oil extracted by pressing. Six (6) oil samples were obtained from seeds of three (3) geogra... The aim of the present study was to evaluate the effects of baobab seed washing and origin on the chemical composition of the oil extracted by pressing. Six (6) oil samples were obtained from seeds of three (3) geographical origins. The identification and quantification of fatty acids and the polyphenolic profile were carried out by GC-MS and HPLC-UV, respectively. Analysis of fatty acid methyl esters allowed the identification and quantification of 18 fatty acids. Oils from unwashed seeds were richer in palmitic (C16:0), stearic (C18:0), oleic (C18:1) and arachidic (C20:0) acids. In addition, HPLC-UV analysis at 279 nm shows that oils from unwashed seeds are richer in tyrosol, hydroxytyrosol and caffeic acid. With regard to the polyphenolic profile, gallic acid and quercetin were not detected in these baobab oils. Principal component analysis of fatty acid and phenolic compound content showed that oils from unwashed seeds would best preserve their chemical and associated potential bioactive characteristics. 展开更多
关键词 Adansonia digitata L. SEEDS Extraction Pressure Oil Fatty Acids TYROSOL Hydroxytyrosol
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Biosecurity in a Biodiversity Hotspot: An Updated Checklist of the Thysanoptera Fauna of New Caledonia
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作者 Christian G. Mille Sylvie Cazères +1 位作者 Hervé Jourdan Laurence A. Mound 《Advances in Entomology》 2025年第1期1-47,共47页
The insect order Thysanoptera is used as an indicator of the vulnerability to foreign insect invasions of New Caledonian ecosystems—both the unique natural systems, and the agricultural and horticultural systems on w... The insect order Thysanoptera is used as an indicator of the vulnerability to foreign insect invasions of New Caledonian ecosystems—both the unique natural systems, and the agricultural and horticultural systems on which the economy is dependent. A total of 103 species in 67 genera of Thysanoptera are here listed from New Caledonia, in contrast to the 68 species in 44 genera that were recorded 23 years ago. Of the 103 species, 22 are not known from anywhere else in the world. Thus, up to 80% of these insect species have arrived in New Caledonia from other countries, with a very high proportion likely to have been introduced through modern trading patterns, despite vigorous efforts by quarantine services. 展开更多
关键词 THRIPS BIOSECURITY Biodiversity New Caledonia QUARANTINE
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Evolutionary factors and habitat filtering affect the pattern of Gerbillinae diversity
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作者 Yaqian Cui Jilong Cheng +6 位作者 Zhixin Wen Anderson Feijó Lin Xia Deyan Ge Emmanuelle Artige Laurent Granjon Qisen Yang 《Current Zoology》 2025年第1期65-78,共14页
How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the ... How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns. 展开更多
关键词 arid regions evolutionary time GERBILLINAE habitat filtering landcover speciation rate
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Biochars improve agricultural production:The evidence base is limited
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作者 Vincent CHAPLOT Philippe BAVEYE +3 位作者 RenéGUENON Elie LE GUYADER Budiman MINASNY Anoop Kumar SRIVASTAVA 《Pedosphere》 2025年第1期295-298,共4页
Biochar application to soil is commonly recognized to improve soil fertility and consequently biomass and food production sustainably.We re-examined the robustness of the underlying data and found that,of the 12000+ p... Biochar application to soil is commonly recognized to improve soil fertility and consequently biomass and food production sustainably.We re-examined the robustness of the underlying data and found that,of the 12000+ publications on“biochar and agriculture”used in meta-studies,only 109 Institute for Scientific Information(ISI)papers(or 0.9%)provide experimental data on the impacts on crop yield and/or biomass production. 展开更多
关键词 SOIL IMPROVE BASE
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稻曲病不同抗性水稻品种的组织化学及分生孢子侵染途径的初步观察 被引量:14
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作者 代光辉 赵杰 +2 位作者 何润梅 金素心 M.NICOLE 《植物病理学报》 CAS CSCD 北大核心 2005年第1期37-42,共6页
用稻曲病菌分生孢子悬浮液对抽穗期水稻进行接种,观察分生孢子及其侵染途径。结果发现,分生孢子在颖壳表面可萌发形成菌丝,在颖口内侧可以见到菌丝伸向谷颖内部,可能为分生孢子直接侵染稻穗提供了一定证据。对抗、感品种谷粒的组织化学... 用稻曲病菌分生孢子悬浮液对抽穗期水稻进行接种,观察分生孢子及其侵染途径。结果发现,分生孢子在颖壳表面可萌发形成菌丝,在颖口内侧可以见到菌丝伸向谷颖内部,可能为分生孢子直接侵染稻穗提供了一定证据。对抗、感品种谷粒的组织化学研究结果表明:抗病品种的颖壳中含有大量的木质素,感病品种中的木质素较少;在抗病品种谷粒的颖壳中的红色荧光物质远远多于感病品种;在抗病品种谷粒表皮的胚乳细胞中也含有多酚类物质,这层细胞较正常细胞大,在感病品种中没有发现。稻曲球切片的紫外光观察可发现每一个稻曲球中存在 6个“蝴蝶”型荧光结构,染色剂染色后观察证明该结构不含过氧化物酶、单宁类物质、木栓质和木质素。 展开更多
关键词 分生孢子 侵染途径 组织化学 抗性水稻品种 抗病品种 感病品种 孢子悬浮液 多酚类物质 过氧化物酶 木质素 稻曲病菌 研究结果 荧光物质 胚乳细胞 正常细胞 抽穗期 颖壳 谷粒 紫外光 染色剂 菌丝 结构 接种 稻穗
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超微血管成像及超声造影在甲状腺结节鉴别诊断中的应用 被引量:20
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作者 赵永锋 周平 +3 位作者 彭洪 刘稳刚 章燕 卢鑫 《中南大学学报(医学版)》 CAS CSCD 北大核心 2019年第6期649-656,共8页
目的:比较超微血管成像(superb microvascular imaging,SMI)与超声造影(contrast enhanced ultrasound,CEUS)对甲状腺结节鉴别诊断的价值,并进一步研究SMI和/或CEUS与二维超声甲状腺影像报告及数据系统(thyroid imagingreporting and da... 目的:比较超微血管成像(superb microvascular imaging,SMI)与超声造影(contrast enhanced ultrasound,CEUS)对甲状腺结节鉴别诊断的价值,并进一步研究SMI和/或CEUS与二维超声甲状腺影像报告及数据系统(thyroid imagingreporting and data system,TI-RADS)联合应用是否可以提高其诊断价值。方法:分别运用SMI,CEUS,二维超声TI-RADS,二维超声TI-RADS联合CEUS,二维超声TI-RADS联合SMI,二维超声TI-RADS与SMI和CEUS 3项联合对甲状腺结节进行良恶性鉴别诊断。将甲状腺结节二维超声TI-RADS分类4b^5类,CEUS低增强,SMI周边为主型血流分布并穿支血管检出作为恶性征象。以术后病理或细针穿刺细胞学检查结果作为参考标准对比其诊断效力。结果:237例患者共296个甲状腺结节被纳入研究。敏感性、特异性、准确率在二维超声TI-RADS诊断时分别为78.4%,77.7%,78.0%;在SMI诊断时分别为75.5%,86.6%,81.4%;在CEUS诊断时分别为82.0%,88.5%,85.5%;在二维超声TI-RADS与SMI和CEUS 3项联合诊断时分别为92.1%,90.4%,91.2%。受试者工作特征曲线下面积(area under the receiver operatingcharacteristic curve,AUROC)在SMI,CEUS,二维超声TI-RADS之间差异无统计学意义(χ2=4.29,P=0.117);二维超声TI-RADS联合CEUS(χ2=39.62,P<0.001),二维超声TI-RADS联合SMI(χ2=36.61,P<0.001)均优于二维超声TI-RADS;二维超声TI- RA DS与SMI,CEUS 3项联合诊断优于二维超声TI- RA DS联合SMI(χ2=4.50,P=0.033)或二维超声TI- RA DS联合CEUS(χ2=4.24,P=0.039)。结论:SMI周边为主型血流分布并穿支血管检出对诊断甲状腺癌具有较高的诊断价值,与CEUS低增强具有相当的诊断效力。SMI和/或CEUS与二维超声TI- R ADS联合应用均可以提高甲状腺结节的鉴别诊断效力。 展开更多
关键词 超微血管成像 超声造影 甲状腺 超声 甲状腺影像报告及数据系统
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基于抗生素使用史的含铋剂四联方案对幽门螺杆菌的根除效果 被引量:10
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作者 唐丹 袁玲芝 +3 位作者 岳纯 蔡婷 姚瑶 王芬 《中南大学学报(医学版)》 CAS CSCD 北大核心 2018年第7期772-778,共7页
目的:基于患者既往抗生素使用史,观察不同抗生素组合的含铋剂四联方案对幽门螺杆菌(Helicobacter pylori,Hp)感染的根除效果,为临床用药提供参考。方法:选择就诊于中南大学湘雅三医院的327名Hp感染患者,针对患者既往抗生素使用情况分别... 目的:基于患者既往抗生素使用史,观察不同抗生素组合的含铋剂四联方案对幽门螺杆菌(Helicobacter pylori,Hp)感染的根除效果,为临床用药提供参考。方法:选择就诊于中南大学湘雅三医院的327名Hp感染患者,针对患者既往抗生素使用情况分别采取A方案[艾司奥美拉唑+丽珠维三联(克拉霉素/替硝唑/枸橼酸铋钾)]、B方案[艾司奥美拉唑+阿莫西林+克拉霉素+胶体酒石酸铋]、C方案[艾司奥美拉唑+多西环素+呋喃唑酮+胶体酒石酸铋],疗程均为14 d,观察用药不良反应,分析不同根除方案疗效。结果:A,B,C三种方案意向性(intention to treat,ITT)分析根除率分别为63.5%,76.2%,82.6%;符合方案(pre protocol,PP)分析根除率分别为76.7%,92.4%,96.4%。B,C方案根除率均高于A方案(P<0.05)。治疗期间药物总不良反应发生率为20.2%,A,B,C三种方案不良反应发生率分别为28.0%(14/50),10.7%(8/75),22.0%(40/182),症状大多轻微,能够耐受。结论:质子泵抑制剂(proton pump inhibitors,PPI)联合丽珠维三联方案Hp根除率低、不良反应发生率高;对于既往未抗Hp治疗、未使用阿莫西林及克拉霉素的患者,选用阿莫西林、克拉霉素的含铋剂四联方案根除率高;对于以往接受抗Hp治疗失败的,或者既往反复使用多种抗生素的患者,选用呋喃唑酮、多西环素的含铋剂四联方案仍可获得较高的Hp根除率,但其药物不良反应发生率较高。 展开更多
关键词 幽门螺杆菌 抗生素使用史 含铋剂四联方案 根除率
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粤北大宝山高含硫多金属矿污染的水稻土壤污染元素的多元分析 被引量:26
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作者 李永涛 张池 +5 位作者 刘科学 Thierry BECQUE Cécile QUANTIN Marc BENEDETTI Patrick LAVELLE 戴军 《华南农业大学学报》 CAS CSCD 北大核心 2005年第2期22-25,34,共5页
调查了粤北大宝山高含硫多金属矿长期污染的水稻田的污染状况,用主成分分析法分析了环境变量间的关系及污染物在样点的空间分布.结果表明:长期的污灌导致了被调查水田土壤中铁矿、硫铜矿和铅锌矿酸性矿泥的沉积,引起土壤酸化和硫、铜、... 调查了粤北大宝山高含硫多金属矿长期污染的水稻田的污染状况,用主成分分析法分析了环境变量间的关系及污染物在样点的空间分布.结果表明:长期的污灌导致了被调查水田土壤中铁矿、硫铜矿和铅锌矿酸性矿泥的沉积,引起土壤酸化和硫、铜、铅和镉的积累.上述污染元素与pH及矿质元素铁、钙之间高度相关,而与锰和铬的相关性差. 展开更多
关键词 重金属污染 水稻土 主成分分析 大宝山 土壤污染
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邻甲苯胺的溶液聚合及聚合物链结构的表征 被引量:6
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作者 许一婷 宋晓晖 +4 位作者 何云游 戴李宗 邹友思 Gal Jean-Yves 吴辉煌 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2002年第1期153-155,共3页
采用溶液聚合法合成邻甲基苯胺聚合物 (POT) ,由于甲基的空间位阻效应大于其给电子效应 ,不利于获得高分子量聚合物 ,从讨论引发剂用量对聚合反应的影响 ,得出可获得数均分子量为 1.90× 10 3的 POT的聚合条件 :反应温度为 0℃ ,p H... 采用溶液聚合法合成邻甲基苯胺聚合物 (POT) ,由于甲基的空间位阻效应大于其给电子效应 ,不利于获得高分子量聚合物 ,从讨论引发剂用量对聚合反应的影响 ,得出可获得数均分子量为 1.90× 10 3的 POT的聚合条件 :反应温度为 0℃ ,p H≤ 1,[M]=1.5 5 4 mol/L,[KPS]/[M]=1∶ 1(摩尔比 ) ,反应时间 2 4 .0 h。1H- NMR和 FT- IR分析结果表明 ,POT聚合物链为半氧化还原结构 emeraldine ,结构单元中苯醌比为 3∶ 展开更多
关键词 聚邻甲苯胺 溶液聚合 分子结构 链结构 表征
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聚苯胺衍生物膜修饰电极的电化学和催化性质 被引量:4
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作者 许一婷 戴李宗 +3 位作者 何云游 Tahina Rakotoartsoa Jean-Yves Gal 吴辉煌 《物理化学学报》 SCIE CAS CSCD 北大核心 2003年第6期564-568,共5页
采用聚-2,5-二甲氧基苯胺(PDMAn)、聚邻甲苯胺(POT)膜修饰电极,以异丙醇(i-P)氧化为模型反应,研究功能性膜电极的电催化性能.两种聚合物的伏安行为都表现为两对氧化还原峰;与镀铂的Pt电极比较,Pt金属化的PDMAn和POT修饰电极,大大提高了... 采用聚-2,5-二甲氧基苯胺(PDMAn)、聚邻甲苯胺(POT)膜修饰电极,以异丙醇(i-P)氧化为模型反应,研究功能性膜电极的电催化性能.两种聚合物的伏安行为都表现为两对氧化还原峰;与镀铂的Pt电极比较,Pt金属化的PDMAn和POT修饰电极,大大提高了i-P氧化电流密度,而且随着循环次数增加,氧化电流不断增大,表明功能性膜修饰电极具有较高的催化活性.POT修饰电极在较低的铂含量下就表现出对i-P的强烈催化活性,而且对低浓度i-P的氧化,具有较高的响应灵敏度;此外POT还具有良好的环境稳定性,可望成为一种具有实际应用前景的电化学传感器. 展开更多
关键词 聚苯胺衍生物膜 修饰电极 电化学 催化性质 聚-2 5-二甲氧基苯胺 PDMAn 聚邻甲苯胺 POT 异丙醇氧化
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木麻黄科植物共生基因遗传转化研究进展 被引量:8
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作者 姜清彬 仲崇禄 +2 位作者 张勇 黄桂华 Clandine FRANCHE 《热带亚热带植物学报》 CAS CSCD 北大核心 2009年第2期205-210,共6页
木麻黄科(Casuarinaceae)植物是世界热带和亚热带地区的造林先锋树种,它能与Frankia放线菌共生形成固氮根瘤,使其具有能够适应各种恶劣环境的优良特性。对木麻黄科植物的共生基因遗传转化研究方法和进展进行了综述,并对今后木麻黄科植... 木麻黄科(Casuarinaceae)植物是世界热带和亚热带地区的造林先锋树种,它能与Frankia放线菌共生形成固氮根瘤,使其具有能够适应各种恶劣环境的优良特性。对木麻黄科植物的共生基因遗传转化研究方法和进展进行了综述,并对今后木麻黄科植物共生基因研究进行了探讨和展望。 展开更多
关键词 木麻黄 共生基因 遗传转化 进展
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汶川地震同震滑坡物质在震区的滞留和运移及其对龙门山地形演化的影响 被引量:2
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作者 王伟 刘静 +7 位作者 Vincent Godard 张金玉 许冲 李志刚 徐心悦 许强 王鹏 谢克家 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2018年第5期1970-1983,共14页
2008年M_W7.9汶川地震导致龙门山断裂发生强烈地壳变形,同时引发的巨量同震滑坡加速了该地区的地表剥蚀和河流侵蚀.然而,目前尚缺少系统的数据定量研究滑坡物质的运移以及河流侵蚀速率随时间的演化规律,这些对理解龙门山前缘物质的再分... 2008年M_W7.9汶川地震导致龙门山断裂发生强烈地壳变形,同时引发的巨量同震滑坡加速了该地区的地表剥蚀和河流侵蚀.然而,目前尚缺少系统的数据定量研究滑坡物质的运移以及河流侵蚀速率随时间的演化规律,这些对理解龙门山前缘物质的再分配以及强震对活动造山带地形塑造的作用至关重要.为此,本研究在汶川地震后的6年间,对震区沱江上游3条支流湔江、石亭江、绵远河流域进行了多期次的定点现代河沙采样.通过系统测量河沙中的石英10Be浓度,并与震前已发表的数据进行对比,发现如下基本特点:(1)震后河沙10 Be浓度均有明显降低,表明同震滑坡物质对河沙的稀释作用;(2)震后河流对河沙的运移量增加为震前的1.3~18.5倍,因此震后龙门山地区侵蚀速率短期显著增加;(3)初步估计得到汶川地震产生的滑坡物质被完全运移出造山带所需要的时间至少为100~4000年,接近龙门山地区强震复发周期;(4)震间和同震产生的构造变形和地表剥蚀在空间上具有互补性.考虑到地表剥蚀引起的地壳均衡反弹效应,认为类似汶川地震的强震有利于龙门山的隆升.认识震前、震时和震后的地壳变形及侵蚀过程有助于更好地理解单次强震事件对高原边界龙门山地形演化的作用. 展开更多
关键词 龙门山 汶川地震 同震滑坡 河流卸载 地形演化
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