有机光致变色功能涂料的研制

对有机光致变色化合物在涂料体系中的应用进行了系统的研究,确定了最佳涂料配方,研制开发了有机光致变色功能涂料,其涂层表现出明显的光致变色性,并讨论了三种不同化合物的光致变色时间与结构的关系,荧光发射光谱以及与无机稀土类光致变色化合物涂料光谱性能的异同,最后研究了涂料的稳定性能和涂层的稳定性,指出关键是化合物呈色体必须有足够的热稳定性和耐疲劳性。     

一种螺噁嗪光致变色自由基化合物的合成与性质

以邻羧基苯肼盐酸盐和甲基异丙基酮为起始原料,经一系列反应得到了一种全新的双功能螺噁嗪光致变色磁性化合物。研究了其光致变色性和顺磁性,结果表明,这种化合物既具有光致变色性,又具有顺磁性。     

苯基-[雌(甾)-17β-醇-3]-偶氮化合物(PED)在聚甲基丙烯酸甲酯薄膜中的光化学异构化反应研究

本文研究了PED偶氮化合物在聚甲基丙烯酸甲酯固体介质中的光化学顺反异构化反应。对此种体系在π,π~*和n,π~*激发条件下光化学顺反异构化的量子产率、光稳态组成以及所在聚合物体系中的自由体积分布等的测定方法和原理进行了详细的介绍。这些方法对其它类似的光致变色体系同样也是适用的。     

有机光存储材料二芳乙烯化合物研究的发展

本在介绍光致变色二芳乙烯化合物的发展动向基础上重点叙述了该类化合物的热稳定性、耐疲劳性、吸收光谱、量子产率、响应时间等各种性质．     

1-苯氧基-9，10-蒽醌的合成与光致变色性研究

报道了一种新的光致变色化合物1．苯氧基-9,10．蒽醌的合成方法,具有较高产率。目标化合物的紫外一可见光谱在387,319,281nm处有3个等吸光点,在波长472nm处吸收变化明显,证明了1-苯氧基-9,10-蒽醌具有光致变色性,且光致变色效果较好。     

1-苯氧基-91,0-蒽醌的合成与光致变色性研究

报道了一种新的光致变色化合物1-苯氧基-91,0-蒽醌的合成方法,具有较高产率。目标化合物的紫外-可见光谱在387,3192,81 nm处有3个等吸光点,在波长472 nm处吸收变化明显,证明了1-苯氧基-91,0-蒽醌具有光致变色性,且光致变色效果较好。     

2-芳氧基-1,8-邻苯二甲酰基萘的合成及光致变色性

合成了3种2-芳氧基-1,8-邻苯二甲酰基萘类光致变色化合物,通过核磁共振谱、红外光谱、质谱和元素分析确定了结构.对产物进行了荧光光谱测定,3种光致变色化合物的荧光强度和Stoke位移都较大.用紫外-可见分光光度计对其在丙酮溶液中的光致变色行为进行了测定,3种光致变色化合物在300—600 nm范围内都具有一定的光致变色性能和较大的吸光系数.     

紫精类杂化光致变色材料的研究进展

紫精是良好的电子受体,受光激发后会发生电子迁移,但是其光还原态极不稳定,而杂化的方式可明显提高化合物的稳定性,因此紫精类杂化光致变色材料具有实际应用价值。文章简要综述了近几年的紫精类杂化光致变色化合物的研究进展。     

全氟环戊二芳基乙烯多功能分子开关的研究进展

全氟环戊二芳基乙烯是近年来国内外备受关注的一类光致变色化合物.其优良的热稳定性、抗疲劳性,使其很有可能成为一种新型的超高密度信息存储、分子开关及光通信材料.主要介绍了该类化合物的结构异构所表现的不同特性的光/热控分子开关、电化学开关、荧光开关、手性开关和液晶等分子开关,并展望了该类化合物的发展前景.     

螺噁嗪类光致变色化合物的制备及其性能初探

通过萘并噁嗪环上引入不同类型的取代基,合成了三种螺噁嗪光致变色化合物。研究了其光致变色性能和抗疲劳性能,结果表明,在紫外灯照射下由无色变为蓝色,这种变化是可逆的,并且具有较高的抗疲劳性。     

Adsorption of superplasticizer admixtures on alkali-activated slag pastes

Alkali-activated slag (AAS) binders are obtained by a manufacturing process less energy-intensive than ordinary Portland cement (OPC) and involves lower greenhouse gasses emission. These alkaline cements allow the production of high mechanical strength and durable concretes. In the present work, the adsorption of different superplasticizer admixtures (naphthalene-based, melamine-based and a vinyl copolymer) on the slag particles in AAS pastes using alkaline solutions with different pH values have been studied in detail. The effect of the superplasticizers on the yield stress and plastic viscosity of the AAS and OPC pastes have been also evaluated.The results obtained allowed us to conclude that the adsorption of the superplasticizers on AAS pastes is independent of the pH of the alkaline solutions used and lower than on OPC pastes. However, the effect of the admixtures on the rheological parameters depends directly on the type and dosage of the superplasticizer as well as of the binder used and, in the case of the AAS, on the pH of the alkaline activator solution. In 11.7-pH NaOH-AAS pastes the dosages of the superplasticizers required to attain similar reduction in the yield stress are ten-fold lower than for Portland cement. In this case the superplasticizers studied show a fluidizing effect considerably higher in 11.7-pH NaOH-AAS pastes than in OPC pastes. In 13.6-pH NaOH-AAS pastes, the only admixture observed to affect the rheological parameters is the naphthalene-based admixture due to its higher chemical stability in such extremely alkaline media.     

Effect of silica fume, metakaolin, and low-calcium fly ash on chemical resistance of concrete

Effects of aggressive chemical environments were evaluated on the mortars prepared with ordinary portland cement (OPC) and silica fume (SF)/metakaolin (MK)/low-calcium fly ash at various replacement levels. The natural adverse chemical environmental conditions were simulated using sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid, and a mixture of sodium and magnesium sulfates. Chemical resistance information was used in conjunction with compressive strength measurements to propose realistic OPC/mineral admixture proportions.     

新型水泥基材料耐久性的预测(英文)

普通硅酸盐水泥（OPC）混凝土的耐久性已经历了一个世纪的试验验证和基础性研究,对一些破坏过程（如冻融）已有了较为深入的了解,但对多数破坏过程还只是泛泛的了解。在已有研究的基础上,通过试验,建立可行的模型,揭示材料的物理性质（如：扩散系数、结晶速率、化学势）可以加快研究的进程。这种方法对于新型水泥基材料的研究和开发尤为重要。新型水泥基材料的长期性能不能直接用OPC的经验模型,要用基于成熟的机理和可测量的物理性能来预测。OPC研究已经揭示了控制新型水泥基材料性能的参数,同时参考全面的数值模拟分析方法能够描述材料的真实行为。建立基于实验测试其性能的模型有利于研究和开发新型水泥基材料。本文综述了几种破坏类型（冻融、盐结晶,锈蚀）的模型及所需量化的性能参数。     

Deicer-scaling resistance of phosphate cement-based binder for rapid repair of concrete

In this paper, a magnesium phosphate cement-based binder (MPB) was prepared by mixing MgO with mono-ammonium phosphate, borax and fly ash. The deicer-scaling resistance of MPB mortar and concrete and the bond strength loss between MPB paste and mortar with ordinary Portland cement (OPC) concrete were investigated. Experimental results show that MPB materials themselves have high deicer-frost resistance, which is not lower than that of OPC concrete with the air content of 4.5-6.5%. The bond strength loss between MPB materials and OPC concrete with the air-entraining agent is obviously lower than that between MPB and OPC concrete without the air-entraining agent, and the higher the air content in OPC concrete is, the smaller the loss is. Furthermore, the air-bubble parameters were analyzed, which indicate that MPB mortar and concrete can also obtain a reasonable air-bubble structure by chemical reactions.     

Preparation,characterization, and antioxidative activity of Bletilla striata polysaccharide/chitosan microspheres for oligomeric proanthocyanidins

Novel oligomeric proanthocyanidins/Bletilla striata polysaccharide/chitosan (OPC/BSP/CTS) microspheres were obtained by spray-drying method. The morphology, size, physicochemical characterization, and in vitro release behavior of the formulation were evaluated. The results of scanning electron microscopy showed OPC-loaded microspheres with considerably wrinkled surfaces and drug-free microspheres with smooth surfaces. Particle-size analysis showed that the diameters of the OPC/BSP/CTS microspheres were 1–5?µm, with uniform distribution (polydispersity below 0.465). Fourier transform infrared indicated the occurrence of a chemical reaction between BSP and CTS. The OPC formed intermolecular hydrogen bonds with BSP/CTS carriers or transmuted amorphous structure. Differential scanning calorimetry displayed the absence of interaction; OPC was only physically encapsulated in the polymer matrix and OPC changed the crystallinity. All the microspheres showed desirable biodegradation rates; the high CTS content retarded their degradation and extended administration times. OPC/BSP/CTS microspheres showed pronounced antioxidant activity than pure OPC. These microspheres can be used as a potential platform to efficiently deliver unstable drugs as a sustained-release oral drug delivery system.     

水泥熟料生产培训系统数据通讯及模型嵌入研究

研究了水泥熟料生产培训系统基于OPC技术的MP72、力控和Matlab实时通讯以及系统模型嵌入的实现方案,并给出了具体实现步骤.基于OPC通讯进行了Matlab电机模型的嵌入,实验表明系统运行稳定可靠并能满足实时性的要求.     

Comparison of solidification/stabilization effects of calcite between Australian and South Korean cements

The differences in the effect of calcite on the strength and stability of Pb-rich wastes solidified and stabilized using Australian and South Korean ordinary Portland cements are examined in this study. Pb-rich waste stabilized using Australian OPC has been shown to possess both substantially higher unconfined compressive strength and lead immobilization ability than South Korean OPC as a result of its higher C₃S content and the associated enhanced degree of precipitation of lead on the surfaces of silicate phases present. Calcite addition is observed to have an accelerating effect on the OPC-induced solidification/stabilization of Pb-rich wastes as gauged by the unconfined compressive strength and leachability of the solids formed. This effect is observed to be far more dramatic for South Korean OPC than for Australian OPC. Using scanning electron microscopy, waste stabilized with cement and calcite was observed to develop significantly greater proportions of hydrated crystals than wastes stabilized with cement alone. The results of X-ray diffraction studies have shown that the presence of calcite in South Korean OPC results in greater acceleration in the formation of portlandite than is the case for Australian OPC.     

Microstructural studies of PMMA impregnated mortars

Studies on cement concrete microstructures are carried out to explain experimentally observed phenomenon and for modeling of concrete at the macroscopic level. In this article, the preparation of polymer impregnated mortar (PIC) is carried out by partially or fully replacing the pores in the cement mortars (OPC) by PMMA. The effect of this polymer impregnation on density and morphology of the cement matrix is studied. The microstructural changes in the mortar, on exposure of these specimens to hydrochloric acid and sea water for 7 and 28 days, are also investigated in this article. The above studies indicated that the polymer addition decreased the voids in the mortar thereby preventing leaching of water soluble salts present in the OPC. It was observed that the polymer also prevented the external chemical media from permeating into the cement matrix and undergoing interactions with it. It is concluded that the durability and chemical resistance properties of the PIC are better compared with OPC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Quality design of belite–melilite clinker

We have developed a new cement clinker, consisting mainly of belite and melilite, which is capable of increasing the amount of recycled waste as a part of its raw materials. We analyzed clinkers with a wide range of compositions, and clarified the quantitative relationship between the chemical and mineral compositions. Clinkers consisting mostly of belite and melilite were successfully obtained at the CaO/SiO₂ mass ratio of 1.7 to 1.9. Test cements were prepared using these clinkers and mixed with OPC for the evaluation of fluidity and strength. The belite–melilite cement was found to have good fluidity, and the belite–melilite cement mixed with OPC at up to 30% exhibited a satisfactory long term strength equivalent to the OPC, demonstrating the potential as an alternative to OPC. Electron probe microanalysis revealed the relatively high concentration of diphosphorus pentaoxide in belite, suggesting this component might contribute to the strength enhancement of the cement.     

Effect of nano-silica on the chemical durability and mechanical performance of fly ash based geopolymer concrete

In this study, the effect of nano silica on the short term severe durability performance of fly ash based geopolymer concrete (GPC) specimens was investigated. Four types of GPC were produced with two types of low calcium fly ashes (FAI and FAII) with and without nano silica, and ordinary Portland cement concrete (OPC) concrete was also cast for reference. For the geopolymerization process, the alkaline activator has selected a mixture of sodium silicate solution (Na₂SiO₃) and sodium hydroxide solution (NaOH) with a ratio (Na₂SiO₃/ NaOH) of 2.5. Main objectives of the study were to investigate the effect of usability or replaceability of nano silica-based low calcium fly ash based geopolymer concretes instead of OPC concrete in structural applications and make a contribution to standardization process of the fly ash based geopolymer concrete. To achieve the goals, four types of geopolymer and OPC concretes were subjected to sulfuric acid (H₂SO₄), magnesium sulfate (MgSO₄) and seawater (NaCl) solutions with concentrations of 5%, 5%, and 3.5%, respectively. Visual appearances and weight changes of the concretes under chemical environments were utilized for durability aspects. Compressive, splitting tensile and flexural strength tests were also performed on specimens to evaluate the mechanical performance under chemical environments. Results indicated that FAGPC concretes showed superior performance than OPC concrete under chemical attacks due to low calcium content. Amongst the chemical environments, sulfuric acid (H₂SO₄) was found to be the most dangerous environment for all concrete types. In addition, nano silica (NS) addition to FAGPC specimens improved both durability and residual mechanical strength due to the lower porosity and more dense structure. The FAIIGPC specimens including nano silica showed the superior mechanical performance under chemical environment.