高分子建筑防水材料工业生产中的卫生防护(上)

对高分子建筑防水材料工业生产中的卫生危害及卫生防护进行了概貌性地评述。     

多层建筑沉降缝对倾及纠偏分析

根据相邻基础相互作用的分析理论 ,发展了被沉降缝分隔的两个建筑单元对倾、纠偏的计算方法。纠偏分析分以下步骤进行 :纠偏前在有效荷载作用下作没有桩支承的两个相邻单元基础的相互作用分析 ;纠偏后在剩余荷载作用下作有静压桩支承的两个相邻单元基础的相互作用分析 ;然后对两个计算结果进行叠加 ;有效荷载相对总荷载的比例与根据沉降观测资料推算的固结度相当。本文的计算方法可近似考虑单桩极限承载力的影响和沉桩产生的拖带作用。最后对一个工程实例进行了分析 ,根据倾斜量与桩数的相互关系可确定控制倾斜和纠偏的最佳桩数     

深厚软土大型油罐搅拌桩复合地基试验研究

本文结合国家石油储运舟山岙山基地成品油罐区4个10000m3油罐的实践，对采用搅拌桩复合地基加固深厚软土建大型油罐问题进行试验研究，简单介绍了设计方法和实施情况，对室内试验和现场测试结果进行了详细分析，提出了一些有价值的结论。     

Interlocked chitosan/poly(dl-lactide) blends

A novel processing method was developed to prepare chitosan/poly(dl-lactide) blends. These blends were further examined for their structures. SEM micrographs exhibited that under optimized processing conditions and with appropriate composition proportions, the resulting blends could possess interlocked internal microstructures. The results obtained from TGA and DMA measurements complementarily confirmed that two components could be well blended into a solid construct at a partially miscible level. The main mechanical properties of the blends were also investigated in both dry and hydrated states.     

Fabrication of chitosan-g-polycaprolactone copolymer scaffolds with gradient porous microstructures

Chitosan-g-polycaprolactone copolymer (CPC) with a relatively low degree of substitution of polycaprolactone (PCL) and a PCL content of around 50 wt.% was first synthesized. CPC was further used to fabricate porous scaffolds with a novel processing method. Basing on a layer-by-layer assembly technique and choosing salt as porogen, these produced scaffolds showed interconnected porous microarchitectures with gradually increasing pore size and porosity along the longitudinal direction. By selecting an appropriate solvent and optimizing processing conditions, the resulting scaffolds would have various pore sizes and porosities which changed from ~ 85 to ~ 390 μm and from ~ 66% to ~ 91%, respectively.     

Quaternized chitosan/rectorite intercalative materials for a gene delivery system

Non-viral vectors have gained increasing attention in gene therapy because of their safety, but with the shortcoming of low transfection efficiency. We have developed a hybrid material as a novel non-viral vector, which combines the advantages of both biopolymer and clay in a gene delivery system. Quaternized chitosan was intercalated into the interlayers of rectorite to obtain a new polymer/layered silicate nanocomposite. In vitro and in vivo toxicity studies revealed that the nanocomposites were biocompatible and non-toxic. At the nanocomposite:pDNA mass ratio of 8:1, they achieved 100% pDNA adsorption capacity. In vitro cell transfection revealed a transfection efficiency of 32.1% at 96?h as shown by a flow-cytometric study, and the intensive green fluorescence protein (GFP) expression could last for up to 120?h. Furthermore, an in vivo transfection study showed that the most prominent GFP expression was observed in the gastric and duodenum mucosa, and good transfection efficiency was also obtained when injected into the muscle. All the results suggest that quaternized chitosan/rectorite nanocomposite is a novel and potential non-viral gene carrier.     

纳米晶Mg2Si块体的制备及力学性能

采用机械激活固相反应及真空热压方法制备纳米晶Mg2Si金属间化合物块体材料.研究表明,过量Mg配量对获得纯相Mg2Si至关重要.在1.5GPa压力于450℃热压得到的纯相Mg2Si纳米块体(相对密度D～98%,晶粒度d～54nm)断裂韧性达1.67MPa·m1/2,较常规粗晶Mg2Si有明显提高.     

Mn(C_2Cl_3O_2)Cl(C_(12)H_8N_2)_2的合成、表征及其纳米晶体参数计算

以Cl3CCOOH、1,10-菲罗啉为配体,以MnCl2·4H2O为金属离子盐,通过溶液蒸发法合成了具有纳米级金属骨架的三元配合物Mn(C2Cl3O2)Cl(C12H8N2)2。通过元素分析、红外光谱、X单晶衍射测得配合物属于单斜晶系,其空间群为P21/c,a=1.8155nm,b=1.0638nm,c=1.4685nm,β=112.9°,z=4,V=2.6110nm3。通过纳米化计算的方法,计算出总晶胞数、总原子数、及表面参数随粒径变化的关系,得出Mn(C2Cl3O2)Cl(C12H8N2)2最佳纳米化尺度为115nm。     

跨临界二氧化碳汽车空调系统的研究与分析

随温室效应日益加剧,二氧化碳制冷剂重新回到人们的视野,引起广泛关注。介绍了跨临界二氧化碳汽车空调系统的组成及热力循环模型,并阐述了系统主要部件压缩机、气体冷却器、蒸发器、节流机构工作性能的影响因素和研究发展方向。     

化工泵用新型复合鼠笼结构屏蔽电机驱动性能及多物理场分析

化工泵用屏蔽电机是化工泵的主要动力源,具有运行可靠、无介质泄漏等优点,因而对其运行性能及多物理场分布情况进行分析十分重要。设计了一种用于化工泵用屏蔽电机的新型复合鼠笼结构,通过商业场路耦合时步有限元软件确定电机尺寸,并对其驱动性能进行了分析。基于流固耦合思路,对比分析了新型复合鼠笼结构以及常规纯铜鼠笼电机的三维温度场分布和应力场分布,通过试验和解析计算,验证了所设计的化工泵用屏蔽电机新型复合鼠笼结构及电机方案的合理性和可行性。在基本确保力能指标的前提下,其起动转矩倍数提高了2.6%,起动电流倍数减小了2.2%,绕组端部温度降低了3.18℃,电机质量和成本均有所降低。