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1.
大同C-P纪高岭岩质煤矸石在不同的煅烧温度与恒温煅烧时间条件下,煤矸石的物理化学性能和化学活性有异.研究结果表明,经600℃煅烧形成的偏高岭石,具有最佳的火山灰活性;掺合经600℃煅烧的大同偏高岭石到水泥中,能显著改善混凝土的力学性能,提高混凝土的密实度和机械强度,为大同高岭岩煤矸石在建材、化工等领域的深加工利用提供了科学依据.  相似文献   

2.
配制了由减水剂、盐类组成的NY 2复合激发剂 ,并将其掺入由 42 5R水泥和粘土混合而成的火山灰水泥中。实验结果表明 ,当粘土掺量为 30 %时 ,掺加 0 .8%~ 1.2 %的NY 2复合激发剂 ,可以在提高水泥早、后期强度的同时 ,改善水泥流动性 ,调整水泥凝结时间并保持火山灰水泥的其他特性。应用该复合外加剂可取得较好的经济效益  相似文献   

3.
配制了由减水剂、盐类组成的NY-2复合激发剂,并将期掺入由425R水泥和粘土混合而成的火山灰水泥中。实验结果表明,当粘土掺量为30%时,掺加0.8% ̄1.2%的NY-2复合激发剂,可以在提高水泥早、后期强度的同时,改善水泥流动性,调整水泥凝结时间并保持火山灰水泥的其他特性。应用该复合外加剂可取得较好的经济效益。  相似文献   

4.
《河南科学》2016,(6):910-916
掺碱激发剂火山灰-水泥既可以有效利用火山灰和保护环境,又可以改善火山灰-水泥胶凝材料的性能.选用掺合料为火山灰,变换不同含量的碱激发剂(氢氧化钠与水玻璃),测定龄期为7、28、90 d时混凝土的力学性能,确定最佳组合,并进行电镜试验,观察微观结构.研究结果表明:掺碱激发剂会使胶凝材料的强度随碱掺量的变化而变化,掺氢氧化钠的早期强度要优于掺水玻璃的早期强度,而后期掺水玻璃的强度要比掺氢氧化钠的强度发展得好.  相似文献   

5.
为推进煤矸石的综合利用,提出对中级硅铝比新采/堆存煤矸石进行煅烧活化,并利用活化产物配制低熟料复合硅酸盐水泥,研究了活化煤矸石对复合水泥性能及水化的影响。结果表明:提高煅烧温度对新采煤矸石活性发挥更为有利,800℃煅烧活化1 h其活性指数达到86%;堆存煤矸石经历了自燃过程,不经煅烧或低温煅烧即具备较高活性,600℃煅烧活化1 h其活性指数达到89%。以熟料、活化新采/堆存煤矸石、石灰石、磷石膏的质量比50∶30∶15∶5配制复合水泥,其28 d抗压强度分别为36.7 MPa和32.1 MPa。由于活化煤矸石颗粒疏松多孔且保留了黏土矿物层状结构,故复合水泥密度低、比表面积大、标准稠度需水量高、凝结时间长,其力学性能发展较为缓慢。进一步提高复合水泥中熟料用量,水泥力学性能提高,当熟料质量分数为70%时,所配制复合水泥力学性能可达到GB 175 《通用硅酸盐水泥》中P.C 42.5等级。  相似文献   

6.
对煤矸石化学成分与煤矸石水泥的28 d抗压强度建立了GM(1.6)的差分方程.以探求不同化学成分对煤矸石水泥28 d抗压强度的影响.结果表明.煤矸石的化学成分中.对煤矸石复合水泥28 d抗压强度影响最显著的成分是CaO.故对煤矸石采用了化学增钙与热复合活化的方法.并对煤矸石不同化学增钙活化后复合水泥的28 d抗压强度性能及复合活化的历程进行了初步的研究.实验结果表明.当煤矸石中掺入适当比例的碳酸钙.经一定的温度热活化后.煤矸石复合水泥的28 d强度有一定程度的提高.  相似文献   

7.
该文以煤系高岭土和碱激发剂水玻璃为原料,煅烧温度、水玻璃模数和掺量为3个试验因素,以凝结时间、强度和收缩值为响应值,利用响应曲面法进行设计3因素3水平试验,通过对回归方程分析探讨制备性能优异的土聚水泥的最优条件参数。研究结果表明,土聚水泥的最佳制备参数为:偏高岭土煅烧温度约为850℃,水玻璃模数为1.1,水玻璃掺量介于19%~20%之间。  相似文献   

8.
采用CaSO_4·2H_2O为活化剂,粉磨2.0h的铁尾矿粉具有火山灰活性.当其掺量为0.5%时,7d、28d活性指数与抗折强度比为最大,最大程度激发了铁尾矿粉的胶凝活性.并采用红外光谱法与微量热法研究了活化机理,研究结论表明:在化学-机械耦合作用下,铁尾矿粉中无序物质增多;而且该铁尾矿粉的掺加促进了水泥铝相的二次水化,显著提高了胶凝活性.  相似文献   

9.
煤矸石水泥复合体系强度的化学激发   总被引:1,自引:0,他引:1  
以正交设计实验法研究了Ca(OH)2、CaSO4.2H2O和NaOH等激发剂对煤矸石水泥复合体系早期强度的影响。结果表明:加入激发剂可以大幅度地提高煤矸石水泥复合体系的3天、7天早期强度;适当掺量的激发剂对复合体系的后期强度也有促进作用。依据实验结果,最佳的Ca(OH)2、CaSO4.2H2O和NaOH激发剂掺量分别为2.5%,4.0%,0.5%。另外,对激发剂对体系强度影响的机理进行了探讨。  相似文献   

10.
尾矿制备辅助胶凝材料是实现尾矿产业化资源利用和减少建筑业碳排放的重要途径. 主要探究了不同活化方法下金尾矿的活性机理和水化特性. 采用高温活化、机械活化和化学-高温-机械复合活化等方法激发金尾矿的活性,探究不同活化方式对金尾矿活性的影响. 测定标准稠度用水量和凝结时间,分析不同金尾矿掺量对复合胶凝材料物理性能的影响. 通过XRD分析、SEM分析和火山灰试验研究了金尾矿的活化机理和水化特性. 结果表明:化学-高温-机械复合活化效果>高温-机械复合活化>机械活化>高温活化. 在化学-高温-机械复合活化下,较原金尾矿28 d抗压强度比(58.25%),治化后的金尾矿强度提高到74.98%. 高温活化和机械活化会使得金尾矿的主要矿物相结晶度降低,但火山灰活性较低. CaO的存在有助于进一步降低结晶度,并在水化反应过程中,其提供的碱性环境,会产生活性SiO2和Al2O3,加速Ca(OH)2与活性SiO2和Al2O3反应,C—S—H凝胶和铝酸盐水合物含量增多,结构更加致密,抗压强度得到提升.  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
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   

18.
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   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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