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1.
Fiber production from inorganic industrial solid wastes is an effective waste management strategy. Because of cost considerations, most enterprises generally use local solid wastes as raw materials to produce fibers. In this study, we explored the feasibility of producing fibers using fly ash and magnesium slag. The results show that the melting temperature of the blends composed of fly ash, magnesium slag, and a small amount of calcined dolomite first decreased and then increased with an increase in acidity coefficient (Mk) from 1.0 to 2.4. The samples could form a eutectic system in the Mk range of 1.4–1.8, and therefore have a relatively low melting temperature in this Mk range. Fly ash could react with magnesium slag and calcined dolomite to form akermanite, gehlenite-magnesium, and anorthite at temperatures close to the melting temperature; therefore, these crystalline phases were the main reaction products formed in the samples with Mk values lower than 1.80. Anorthite reacted further with some Na-containing and Si-containing spieces to produce labradorite. Thus, the content of anorthite and labradorite rapidly increased and they became the major crystal phases in the blend samples with Mk values greater than 1.80. MAS-NMR spectroscopic analysis revealed that the network structure of the melts depended on the ratio of bridging oxygen to non-bridging oxygen; a high ratio of bridging oxygen to non-bridging oxygen could lead to the formation of a dense network structure in the melt. The blends of fly ash and magnesium slag can be used to produce wool fibers and continuous fibers. In addition, the suitable temperature ranges for the production of both types of fibers were determined. The drawing temperature for continuous fiber production depended on the degree of polymerization and structure of the melt.  相似文献   
2.
In this study, blends of the bio-based poly(limonene carbonate) (PLimC) with different commodity polymers are investigated in order to explore the potential of PLimC toward generating more sustainable polymer materials by reducing the amount of petro- or food-based polymers. PLimC is employed as minority component in the blends. Next to the morphology and thermal properties of the blends the impact of PLimC on the mechanical properties of the matrix polymers is studied. The interplay of incompatibility and zero-shear melt viscosity contrast determines the blend morphology, leading for all blends to a dispersed droplet morphology for PLimC. Blends with polymers of similar structure to PLimC (i.e., aliphatic/aromatic polyester) show the best performance with respect to mechanical properties, whereas blends with polystyrene or poly(methyl methacrylate) are too brittle and polyamide 12 blends show very low elongations at break. In blends with Ecoflex (poly(butylene adipate-co-terephthalate)) and Arnitel EM400 (copoly(ether ester)) with poly(butylene terephthalate) hard and polytetrahydrofuran soft segments) a threefold increase in E-modulus can be achieved, while keeping the elongation at break at reasonable high values of ≈200%, making these blends highly interesting for applications.  相似文献   
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4.
Based on the 3 factors and 3 levels orthogonal experiment method, compositional effects of Mg, Si, and Ti addition on the microstructures, tensile properties, and fracture behaviors of the high-pressure die-casting Al-x Mg-y Si-z Ti alloys have been investigated. The analysis of variance shows that both Mg and Si apparently infl uence the tensile properties of the alloys, while Ti does not. The tensile mechanical properties are comprehensively infl uenced by the amount of eutectic phase(α-Al + Mg_2Si), the average grain size, and the content of Mg dissolved into α-Al matrix. The optimized alloy is Al-7.49 Mg-3.08 Si-0.01 Ti(wt%), which exhibits tensile yield strength of 219 MPa, ultimate tensile strength of 401 MPa, and elongation of 10.5%. Furthermore, contour maps, showing the relationship among compositions, microstructure characteristics, and the tensile properties are constructed, which provide guidelines for developing high strength and toughness Al–Mg–Si–Ti alloys for high-pressure die-casting.  相似文献   
5.
基于现有热成形零件冷弯性能不足、氢脆敏感性强等共性技术问题,在22MnB5钢的基础上采用Nb、V微合金化的设计思路,对试验钢的显微组织、淬透性和极限尖冷弯性能进行研究。结果表明:微合金化前后22MnB5热成形钢的显微组织均为全马氏体,但是微合金化后的试验钢组织更为细小;Nb-V微合金化能有效提高22MnB5热成形钢的淬透性,其淬硬层深度达到13~14 mm,并且试验钢的极限尖冷弯角达到58°~72°,进一步拓宽了热冲压成形的工艺窗口。综合分析试验钢微观组织、淬透性能及极限尖冷弯性能的检测结果,添加0.04%Nb和0.04%V实现复合微合金化,提升材料的综合强塑性,满足了高冷弯性能汽车零部件用材需求。  相似文献   
6.
井筒完整性对超深井安全高效生产意义重大,为揭示改造液对完井管柱的腐蚀规律,选取超深井改造常用的5种改造液与超级JFE 13Cr材质油管试片,通过金属挂片失重法和应力腐蚀实验,评价了超深层改造液对13Cr材料的腐蚀和新型高密度盐水加重压裂液缓蚀剂的缓蚀性能。结果表明,5种改造液对13Cr材质油管试片均存在一定程度的表面腐蚀,在140℃下的腐蚀速率为4.8~10.6 g/(m2·h)。当加载90%应力屈服强度时,试片在5种改造液中均出现不同程度的应力开裂裂纹,其中在硝酸钠加重压裂液中的应力腐蚀较为显著。在硝酸钠和氯化钙加重压裂液中加入由炔胺类化合物及一些金属化合物组成的高浓度缓蚀剂后,应力腐蚀显著缓解。该项研究对认识改造液的应力腐蚀、安全高效改造超深井油田具有借鉴意义。  相似文献   
7.
油气处理站库集散式控制系统(DCS)是对油、气、水处理全过程、多环节、多领域,以生产过程数据实时采集及处理、智能分析、控制的工业控制系统。集散式控制系统实现智能化和管控一体化,仅依靠传统防火墙和IT信息安全技术体系已无法有效应对,亟需在攻防地位严重不对称、存在大量被漏洞被后门的现实环境中,建立全生命周期管控的深度防护整体解决方案。  相似文献   
8.
将Copulas理论引入文本特征词关联模式挖掘,提出融合Copulas理论和关联规则挖掘的查询扩展算法.从初检文档集中提取前列n篇文档构建伪相关反馈文档集或用户相关反馈文档集,利用基于Copulas理论的支持度和置信度对相关反馈文档集挖掘含有原查询词项的特征词频繁项集和关联规则模式,从这些规则模式中提取扩展词,实现查询扩展.在NTCIR-5 CLIR中英文本语料上的实验表明,文中算法可有效遏制查询主题漂移和词不匹配问题,改善信息检索性能,提升扩展词质量,减少无效扩展词.  相似文献   
9.
以黑木耳(Auricularia auricula-judae)粉末为材料,研究了超声微波联用辅助提取黑木耳黑色素的方法。通过单因素实验考察黑木耳干粉粉碎粒度、超声功率、微波功率和超声微波联用时间对提取效果的影响,并采用响应面法优化工艺条件。通过与传统溶剂提取法及超声辅助提取法进行比较,结合扫描电镜(Scanning electron microscope)观察不同提取方法对于黑木耳干粉组织结构的破坏程度,以此验证超声微波联用辅助提取黑木耳黑色素的优势。结果表明:木耳黑色素的最佳提取工艺条件是:超声功率398 W、微波功率392 W、联合作用时间31 min。此条件下黑木耳黑色素吸光度为0.984,粗黑色素得率达到9.10%,相较传统溶剂法提取法(7.20%)、超声辅助提取法(5.20%)分别提高26.38%、75.00%。经比较不同提取方法后的黑木耳组织的SEM图像,表明黑木耳组织经超声微波联用辅助提取方法后,组织结构破损严重。结果证实:超声微波联用辅助提取黑木耳黑色素的方法相较于传统溶剂法可节约溶剂的使用量,相较于超声辅助提取法所耗费的时间有所减少,并且可提升黑木耳黑色素得率。  相似文献   
10.
With the blossom of information industry, electromagnetic wave technology shows increasingly potential in many fields. Nevertheless, the trouble caused by electromagnetic waves has also drawn extensive attention. For instance, electromagnetic pollution can threaten information safety in vital fields and the normal function of delicate electronic devices. Consequently, electromagnetic pollution and interference become an urgent issue that needs to be addressed. Carbon nanotubes (CNTs) have become a potential candidate to deal with these problems due to many advantages, such as high dielectric loss, remarkable thermodynamic stability, and low density. With the appearance of climbing demands, however, the carbon nanotubes combining various composites have shown greater prospects than the single CNTs in microwave absorbing materials. In this short review, recent advances in CNTs-based microwave absorbing materials were comprehensively discussed. Typically, we introduced the electromagnetic wave absorption mechanism of CNTs-based microwave absorbing materials and generalized the development of CNTs-based microwave absorbers, including CNTs-based magnetic metal composites, CNTs-based ferrite composites, and CNTs-based polymer composites. Ultimately, the growing trend and bottleneck of CNTs-based composites for microwave absorption were analyzed to provide some available ideas to more scientific workers.  相似文献   
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