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聚羧酸系减水剂作为助磨剂使用的构效关系研究

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建筑材料学报 2022年第1期25卷 54-60页

作者：杨海静孙振平 plank johann 水亮亮董耀武同济大学先进土木工程材料教育部重点实验室上海201804 同济大学材料科学与工程学院上海201804 慕尼黑工业大学化学系德国加兴85747 上海市政工程设计研究总院(集团)有限公司上海200092 武汉优城科技有限公司湖北武汉430000

采用甲基烯丙基聚氧乙烯醚(HPEG)为大单体合成一系列具有不同酸醚比、侧链长度及相对分子质量的聚羧酸系减水剂(PCE)作为水泥助磨剂,研究了PCE分子结构对其助磨性能的影响.结果表明:PCE的助磨效果随着酸醚比的增大而增强,当酸醚比超过... 详细信息

采用甲基烯丙基聚氧乙烯醚(HPEG)为大单体合成一系列具有不同酸醚比、侧链长度及相对分子质量的聚羧酸系减水剂(PCE)作为水泥助磨剂,研究了PCE分子结构对其助磨性能的影响.结果表明:PCE的助磨效果随着酸醚比的增大而增强,当酸醚比超过一定范围后,助磨效果有所减弱;具有短侧链及低相对分子质量的PCE具有更好的助磨效果;PCE磨制水泥的标准稠度用水量降低,16 h抗压强度降低,28 d抗压强度没有损失.

关键词：水泥助磨剂聚羧酸系减水剂分子结构粉磨效率

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欧洲干混砂浆技术发展趋势

欧洲干混砂浆技术发展趋势

首届全国商品砂浆学术会议

作者： johann plank 慕尼黑技术大学

1 引言20世纪60年代之前,欧洲的砂浆无一例外都是在施工现场拌制的,即将原料如胶凝材料(水泥、石灰、石膏)和砂子运送到施工现场,再由人工小批量拌合使用。这种技术存在两大缺点。第一,由于原料质量差、施工现场储存环境不良以及混合比...

1 引言20世纪60年代之前,欧洲的砂浆无一例外都是在施工现场拌制的,即将原料如胶凝材料(水泥、石灰、石膏)和砂子运送到施工现场,再由人工小批量拌合使用。这种技术存在两大缺点。第一,由于原料质量差、施工现场储存环境不良以及混合比例不精确,砂浆质量的波动较大,且没有任何质量控制。无论砂浆的质量是否达到要求,其质量都取决于施工工人的操作技能。第二,现场搅拌和手工操作需要更多的工人来参与完成。

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性能优越的混合金属氢氧化物-膨润土钻井液

国外油田工程 2001年第8期17卷 34-35,57页

作者： johann plank 高光军中国石油天然气集团公司工程技术研究院

钻井液对油气井钻探和隧道开凿的成功至关重要 ,用含有悬浮膨润土颗粒的混合金属氢氧化物 (MMH)配制的钻井液具有优越的剪切稀释流变特性 ,特别适用于油气田钻井和施工钻孔。本文从MMH的形成、化学结构、稠化效应及作用方式模型等多方... 详细信息

钻井液对油气井钻探和隧道开凿的成功至关重要 ,用含有悬浮膨润土颗粒的混合金属氢氧化物 (MMH)配制的钻井液具有优越的剪切稀释流变特性 ,特别适用于油气田钻井和施工钻孔。本文从MMH的形成、化学结构、稠化效应及作用方式模型等多方面对其特性进行了解释 ,并举例说明其成功的应用。

关键词：钻井液剪切稀释流变性显微图三维网络模型

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当今欧洲混凝土外加剂的研究进展

当今欧洲混凝土外加剂的研究进展

超细粉掺合料专用聚羧酸减水剂的制备及性能研究

作者： johann plank 赵霄龙薛庆刘岩德国慕尼黑大学无机化学系建筑化学品研究所中国建筑科学研究院中国建筑科学研究院中国建筑科学研究院

＜正＞很早以前人们就已经发现,在建筑材料中使用外加剂可以提高其性能。例如,在古罗马,人们把蛋白质作为石膏的缓凝组分,把干血作引气剂使用。当今建筑工程中使用的外加剂则可以起缓凝、速凝、塑化、增黏、抗离析、保水、减缩、消泡、...

＜正＞很早以前人们就已经发现,在建筑材料中使用外加剂可以提高其性能。例如,在古罗马,人们把蛋白质作为石膏的缓凝组分,把干血作引气剂使用。当今建筑工程中使用的外加剂则可以起缓凝、速凝、塑化、增黏、抗离析、保水、减缩、消泡、防水、纤维增强等作用。

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新型建筑材料 2024年第1期51卷 49-53,64页

作者：谢瑞兴于奂泽岳光亮唐樱燕彭立刚于彭 johann plank 山东众森新材料有限公司山东济南250000 北京王府学校北京102209 山东众森科技股份有限公司山东济南250000 德国慕尼黑工业大学德国慕尼黑80539

为解决超细粉掺合料在混凝土应用中出现的黏度大、流速时间长、易抓底、收缩大的问题,通过合成原料的选择以及调整合成工艺,合成了超细掺合料专用聚羧酸减水剂ZS-CX。结果表明,采用EPEG单体、合成起始温度15℃、滴加反应时间60 min,MAP... 详细信息

为解决超细粉掺合料在混凝土应用中出现的黏度大、流速时间长、易抓底、收缩大的问题,通过合成原料的选择以及调整合成工艺,合成了超细掺合料专用聚羧酸减水剂ZS-CX。结果表明,采用EPEG单体、合成起始温度15℃、滴加反应时间60 min,MAP用量为单体质量的0.6%时,制备的减水剂性能最佳。与市售减水剂相比,净浆流动度、混凝土坍落度和扩展度增大,倒筒排空时间更短,达到5 s,Zeta电位绝对值大,而且混凝土60 d电通量小于1000 C、收缩率降低30%以上。

关键词：超细粉掺合料聚羧酸减水剂合成混凝土性能

General Solutions of First-Order Algebraic ODEs in Simple Constant Extensions

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Journal of Systems Science & Complexity 2023年第4期36卷 1769-1788页

作者： MITTERAMSKOGLER johann Josef WINKLER Franz Research Institute for Symbolic Computation(RISC) Johannes Kepler Universität LinzA-4040 LinzAustria

If a first-order algebraic ODE is defined over a certain differential field,then the most elementary solution class,in which one can hope to find a general solution,is given by the adjunction of a single arbitrary constant to this *** of this type give rise to a particular kind of generic point—a rational parametrization—of an algebraic curve which is associated in a natural way to the ODE’s defining *** for the opposite direction,we show that a suitable rational parametrization of the associated curve can be extended to a general solution of the ODE if and only if one can find a certain automorphism of the solution *** automorphisms are determined by linear rational functions,i.e.,Möbius *** properties of rational parametrizations,in combination with the particular shape of such automorphisms,lead to a number of necessary conditions on the existence of general solutions in this solution ***,the desired linear rational function can be determined by solving a comparatively simple differential system over the ODE’s field of *** results hold for arbitrary differential fields of characteristic zero.

关键词： Algebraic curve algebraic differential equation general solution Möbius transformation rational parametrization

Bare-throated spurfowl(Pternistis spp.)males across Africa impress females with bright throat colours during courtship

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Avian Research 2023年第3期14卷 416-424页

作者： johann H.van Niekerk Department of Environmental Sciences College of Agriculture and Environmental SciencesUniversity of South AfricaP.O.Box 392Pretoria0003South Africa

The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract *** the 23 Afrotropical spurfowl species,the bare-throated subgroup includes Yellow-necked Spurfowl(Pternistis leucosceptus),Rednecked Spurfowl(***),Grey-breasted Spurfowl(***) and Swainson’s Spurfowl(***).The rest of the species include fully feathered throated *** colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year’s *** throat(n=836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities,breeding cycles,and environmental *** for Swainson’s Spurfowl male saturation of throat colours correlated with monthly rainfall,which peaks one or two months before egg ***’s Spurfowl peaks during egg ***-necked Spurfowl has the largest bare ***-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat *** such displays occur in feather-throated *** with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated *** Red-necked Spurfowls have significantly larger bare throats than *** primary function of bare throats probably assists in thermoregulation,particularly in arid *** bare throat may have evolved a secondary role in ***-necked,Red-necked,and Greybreasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding *** female throat colours(unsaturated) may discourage male interlopers and predation during egg *** appears to be carotenoid-food *** different colours among the bare-throated species may serve as prezygotic mechani

关键词： Bare-throated spurfowls Breeding Colour saturation Ornaments Pternistis spp. Sexual size dimorphism

Orange River Francolins(Scleroptila levaillantoides)persist in fragmented Highveld farming landscapes,South Africa

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Avian Research 2017年第2期8卷 83-90页

作者： johann H.van Niekerk Department of Environmental Sciences College of Agriculture and Environmental ScienceUniversity of South AfricaPO Box 392Pretoria 0003South Africa

Background:How do Orange River Francolins(Scleroptila levaillantoides) adapt to an intensive farming landscape with grass(grazing) camps and crop cultivation? To answer this question, a study was carried out in south-east of johannesburg in South Africa to clarify the interaction of francolins with a landscape consisting of land use ***:A transect-road of 45 km was traversed weekly during November 2015–October 2016 through flat maize(Zea mays) and cattle(Bos primigenius) grazing fields. Francolins were counted in three land use mosaic types along the transect-road(including the road):grass camps on both sides of the road(grass/grass edges); arable fields on both sides(arable/arable edges) and arable land on one side with grass camps on the opposite side of the road(arable/grass edges).Results:Francolins used all three mosaic types, but the arable/arable edges were least frequented. Nonetheless, the arable/arable edges played an important part:francolins, including females with chicks, moved along the arable/arable edges, which enabled contact between sub-populations, and the arable/arable edges provided temporary cover(e.g. stubble and maize plants) and ploughed firebreaks to forage(e.g. for bulbs).Conclusion:Cultivation of crop within grasslands does not constrain breeding, movement and habitat use by the Orange River Francolin. For conservation purposes it is critical that the fine-scale mosaic of grazing and cultivation areas remain intact.

关键词： Agriculture Edge habitat Management Mosaics Orange River Francolin Scleroptila levaillantoides

Vocal behavior of Crested Guineafowl(Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve,Kwa Zulu-Natal province,South Africa

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Chinese Birds 2015年第3期6卷 132-139页

作者： johann H.van Niekerk Department of Environmental Sciences College of Agriculture and Environmental SciencesUniversity of South Africa

Background:Generally speaking,playbacks were often ineffective to determine the group sizes of birds since mainly males from leks *** limitation has not been tested properly for flocking birds such as Crested Guineafowl(Guttera edouardi) with the view to use it as a counting *** aims of the study reported in this paper were(1) to describe the cal s of Crested Guineafowl in a social context;(2) to interpret cal s in an evolutionary context;and(3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in smal isolated ***:The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve(Kwa Zulu-Natal,South Africa) from November 2010 to June *** line observations and sound playback methods were ***:The behavioral context and structure of cal s were *** eight cal s described for Crested Guineafowl were produced mainly to unite flock members in the dense understory,where visibility was poor,and to repel *** not disturbed,Crested Guineafowl were quiet and only made soft contact ***:The high rate of call back and the fact that flocks invariably approach the source of the call en masse,shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a *** value of playbacks as a conservation tool is assessed.

关键词： Guttera edouardi Playback Calls Social behavior Flocking Transect surveys