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1.
实验合成了氨基磺酸系高效减水剂,同时对产物进行净浆流动度经时损失和砂浆减水率的试验.结果表明该产品对水泥的适应性较好,并能较长时间防止流动度损失,掺量为0.8%时,3h的净浆流动度仍在180mm以上.在已有的氨基磺酸系高效减水剂基础上,引入三种改性剂,经物理复配制成三种复合型氨基磺酸系高效减水剂,实验证明该产品具有掺量小而减水率高的特点,掺量为0.8%时,砂浆减水率达28.0%.  相似文献   

2.
本文介绍了SM高效减水剂的合成试验,该产品的物理性能与国外同类产品的性能相近,已经达到甚至超过国家一级品减水剂的标准。  相似文献   

3.
高效减水剂的应用与发展   总被引:7,自引:0,他引:7  
介绍高效减水剂的种类和分子结构及国内外有关高效减水剂的质量标准,详述高效减水剂对新拌和硬化混凝土性能的影响及高效减水剂与水泥颗粒的作用机理,提出现有高效减水剂存在的问题和高效减水剂今后研究开发的方向。  相似文献   

4.
吴军 《科技资讯》2006,(33):36-36
本文介绍了改性废旧聚苯乙烯高效减水剂(复合一定比例的萘系高效减水剂)的产品性能,通过对其性能的测试,发现其减水率高,抗渗性好,混凝土塌落度损失小,施工工艺好等特点,是建材行业中变废为宝的利国利民的典型之一。  相似文献   

5.
共聚羧酸高效减水剂的合成与性能评价(第三部分)   总被引:3,自引:2,他引:3  
合成出一类含多种侧链官能团的共聚羧酸高效减水剂(CoPoCa-Ⅲ)。这类共聚物分子中带有羧酸及其盐,磺酸及其盐,羟基,酯基及醚基等。减水率≥28-30%,新拌混凝土初始坍落度很大,且1h内坍落度保持性≥90%,混凝土28d抗压强度最大增加56%。CoPoCa-Ⅲ类高效减水剂还可以与萘系减水剂复配使用,采用20%和CoPoCa-Ⅲ与80%萘系复配的复合型高效减水剂,显改善了萘系减水剂的减水率和混凝土坍落度保持性能。  相似文献   

6.
丙酮,甲醛和亚硫酸钠为主要原料合成了脂肪族羟基磺酸盐类高效减水剂,讨论了合成条件对产物分散性能的影响并研究了这类高效减水剂的应用性能。丙酮,甲醛和亚硫酸钠在一定摩尔比条件下,通过适当的混合和加入,在90~93℃时反应3h。所得的产物脂肪族羟基磺酸盐高效减水剂HAF具有良好的分散性能。合成的高效减水剂HAF对水泥净浆有轻微缓凝作用;在混凝土中掺量为0.5%时,减水率达到19%,且具有明显的早强和增加抗压强度的特性。  相似文献   

7.
萘系高效减水剂的合成和性能研究   总被引:11,自引:0,他引:11  
浓硫酸滴加到萘中生成β-萘磺酸,在甲酸作用下合成出聚萘磺酸盐,并对它们的结构性能和作用机理进行了研究,结果表明,聚萘磺酸盐是一种优良的高效减水剂,在一定的条件下能合成出具有20%-30%减水率的高效减水剂,另外发现合成条件对建筑土的净浆流动性有着很大的影响。  相似文献   

8.
将碱法麦草浆黑液蒸发、磺化制得的SL型普通砼减水剂,其减水率≥8%,抗压强度增长率R_3≥15%,R_7≥15%,R_(28)≥10%,完全达到了国标GB8076—87的要求。 进一步的试操性试验表明,采用改性剂改性可使SL型普通减水剂达到高效减水剂的水平。  相似文献   

9.
产品包括JN高效减水剂、JN高效减水剂(缓凝型)、JN-2超塑化剂(高浓型)与JN-3缓凝高效减水剂,通过工艺及特殊的技术措施,使JN-2与JN-3的硫酸钠含量显著降低,改善了缓凝型产品对水泥的适应性,在预拌混凝土、泵送混凝土、大体积混凝土、防水混凝土、高强混凝土、预制混凝土、路桥混凝土等领域应用,提高了工程质量,节省了水泥,并降低了混凝土成本,技术经济效益显著.  相似文献   

10.
概述高效减水剂的合成方法,并通过和其他减水剂性能的比较,阐述了推广应用的价值。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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