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61.
改性硫氧镁胶凝材料的配制及性能研究 总被引:1,自引:0,他引:1
为确定工业级轻烧氧化镁粉与七水硫酸镁溶液配制改性硫氧镁胶凝材料的最优参数,分别研究了不同氧化镁/七水硫酸镁摩尔比,硫酸镁溶液浓度及水稳剂水玻璃对硫氧镁胶凝材料工作和力学性能的影响.结果表明:随着氧化镁/硫酸镁摩尔比的提高,硫氧镁水泥的初凝时间逐渐缩短,流动性逐渐降低,抗压和抗折强度逐渐提高;随着七水硫酸镁浓度的提高,硫氧镁水泥的抗压抗折强度也呈现增长趋势,MgO:MgSO4·7H2O:H2O摩尔比为14:1:12时,硫氧镁胶凝材浆体的28d抗压和抗折强度分别达到38.3MPa和7.0MPa.耐水性研究表明,加入氧化镁质量2%的水玻璃可以很好地改善硫氧镁水泥的耐水性. 相似文献
62.
With all driving fields on Raman resonance, a tripod-type atomic system quickly evolves into a dark state decoupled from the lossy excited level. The dark state depends strongly on field Rabi frequencies, spontaneous decay rates, and the initial atomic population in a complicated way. Analytical results reveal that it is a sixfold degenerate dark state with its three components superposed both coherently and incoherently due to population redistribution from spontaneous emission. 相似文献
63.
Brinkmann G Fowler PW Justus C 《Journal of chemical information and computer sciences》2003,43(3):917-927
Representation of isomerization and carbon insertion or extrusion mechanisms as patch replacements on a fullerene surface allows construction of a catalogue of topologically distinct local transformations of fullerenes, classified by patch boundary and pentagon content. All isomerization patches and isomerization pairs containing up to five pentagons and with an upper limit for the boundary length depending on the number of pentagons are listed. Several infinite series of transformations are identified. 相似文献
64.
In the simulation of a liquid drop it is expensive to calculate the excess pressure and obtain the surface tension by the Laplace formula. We use the Kelvin formula which only requires the vapour density, or at most the virial pressure. Some results are given for a Lennard-Jones 12-6 fluid. 相似文献
65.
David B. Redmond Charles M. Quinn Patrick W. Fowler 《Journal of mathematical chemistry》1998,23(3-4):263-276
Some new aspects of qualitative molecular-orbital theory are developed within the context of group theory and a symmetrized
Hückel approximation. Conclusions concerning the eigenvalue sums for sets of eigenfunctions of the same symmetries, the occurrence
of repetitions of symmetry-adapted projections and the relations between eigenvalues of Γg and Γu symmetries are exemplified using the 120 cage structure of Ih point symmetry. The implications of the orbit-by-orbit approach are outlined for larger clusters.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
66.
Tian J Ma S Thallapally PK Fowler D McGrail BP Atwood JL 《Chemical communications (Cambridge, England)》2011,47(27):7626-7628
Cucurbit[7]uril (CB[7]), in its amorphous solid state, shows one of the highest CO(2) sorption capacities among known organic porous materials at 298 K and 0.1 and 1 bar. In addition to the highest CO(2) capacity, CB[7] also shows remarkable selectivity of CO(2) over N(2) and CH(4). These properties, along with the existence of readily available precursors, indicate amorphous CB[7] might find applications in recycling CO(2) particularly considering the easy synthesis and potentially low manufacturing costs. 相似文献
67.
G.N. Fowler 《Molecular physics》2013,111(4):383-386
The response of a molecular crystal to electromagnetic radiation is discussed in terms of a response function using the analogy of the electron gas and the results of the previous paper. A qualitative explanation of the phenomenon of hypochromism is suggested according to which the ‘missing’ oscillator strength goes into the photon-exciton modes found by Hopfield. 相似文献
68.
LIU Yan-Ping CHEN Zhao-Yang BA Wei-Zhen FAN Yan-Wei DU Yan-Zhao PAN Shi-Lie GUO Qi 《中国物理C(英文版)》2008,32(5)
The optically stimulated luminescent (OSL) radiation dosimeter technically surveys a wide dynamic measurement range and a high sensitivity.Optical fiber dosimeters provide capability for remote monitoring of the radiation in the locations which are difficult-to-acoess and hazardous.In addition.optical fiber dosimeters are immune to electrical and radio-frequency interference.In this paper,a novel remote optical fiber radiation dosimeter is described.The optical fiber dosimeter takes advantage of the charge trapping materials CaS:Ce, Sm that exhibit OSL.The measuring range of the dosimeter is from 0.1 to 100 Gy.The equipment is relatively simple and small in size,and has low power consumption.This device is suitable for measuring the space radiation dose and also can be used in high radiation dose condition and other dangerous radiation occasions. 相似文献
69.
Perdeuterated benzofluoranthenes have slightly shorter retention times than their equivalent unlabeled forms in a DB-5 capillary column. Under column overload conditions, perdeuterated benzofluoranthenes in moderate multifold excesses, which might be encountered in their use as internal standards and carriers for quantitative analysis, are seen to exhibit both normal and reverse solvent effects on their close eluting congeners. In some cases the effects may be used to advantage by knowledgeable analysts, but for the ignorant and unwary the effects can lead to serious errors in identification and quantification. 相似文献
70.
The as-deposited and annealed Ge-Au film and Ge-Au/Au bilayer films have been observed by transmission electron microscopy. The bilayer with a composition of Ge-5at%Au film is amorphous, while the Ge-22at%Au film is polycrystalline. Higher concentration of Au raises the structural heterogeneity and instability. Fractals can be observed in the Ge-5at%Au/Au bilayer samples annealed at 60-100℃. The difference of the fractal patterns generated from Ge-Au/An and a-Ge/Au films call be attributed to the higher heterogeneity and instability in Ge-Au/An bilayers. 相似文献