BFRP筋再生混凝土梁抗弯性能试验研究

通过7根玄武岩纤维(BFRP)筋再生混凝土梁和1根钢筋再生混凝土梁的抗弯性能试验,研究了不同纵筋配筋率与再生骨料取代率对BFRP筋再生混凝土梁受弯性能的影响,分析其承载力变化过程、破坏形态、挠度变形与裂缝发展情况,并与钢筋再生混凝土梁进行对比。结果表明,BFRP筋再生混凝土梁的破坏形式有少筋和超筋破坏两种,分别由BFRP筋拉断和受压区再生混凝土压碎控制。合理配筋的BFRP筋再生混凝土梁破坏前产生的挠度较大,且受拉BFRP筋的应变也较大,说明合理配筋的BRPP筋再生混凝土梁具有一定的延性,能较好地发挥两种材料的性能。BFRP筋再生混凝土梁的裂缝宽度和裂缝条数受再生骨料取代率影响较小,而受配筋率影响较大。此外,BFRP筋再生混凝土梁的初裂荷载相比钢筋再生混凝土梁略低,但极限荷载却有明显提高。     

The effects of fiber orientation on failure behaviors of 2D C/SiC torque tube

Different failure behaviors were observed in the 2D C/SiC torque tubes which were fabricated by chemical vapor infiltration (CVI) with different fiber orientations (0°/90° and ±45°). CT test was implemented to characterize the density heterogeneity of the ceramic matrix composite (CMC) torque tubes. With the density value measured by Archimedes drainage method, FEM software was implemented to simulate the stress distribution of the ceramic matrix composite torque tubes and calculate the failure stress. Torsional tests were conducted using special attachments to a universal material test machine. Different torsional behaviors of CMC torque tubes with two different fiber orientations were presented in the stress-strain curves. The fracture morphologies were observed by SEM, and the predominant factors of failure were analyzed. CMC torque tubes with fiber orientation of ±45° have a higher torque capacity and modulus. In failure analysis, we found that ±45° fiber orientation CMC torque tubes have reasonable fracture morphologies.     

高储氧能力的Ce—Zr—La—Y—AI储氧材料的制备

采用共沉淀法制备了多组分储氧材料ce0.5 Zr0.15 Y0.075 La0.075 O1.825。在以氨水和碳酸铵为共沉淀剂、聚乙二醇为表面活性剂、pH值约10．O、H202与Ce的摩尔比为1：1、聚乙二醇与氧化物的质量比为1：1、陈化温度为90℃的条件下,500℃煅烧时储氧材料的储氧量达587．0μmo1．g-1,1000℃煅烧时储氧量达399．9μmol·g-1。老化样品的储氧量远高于摩托车欧Ⅲ排放标准中对三效催化剂中储氧材料储氧性能的要求,且该储氧材料的储／放氧性能稳定。     

基于模糊预测型线性规划模型的矿山产能配置

将线性规划与模糊数学及灰色理论有机结合,构建了与产能分配实际情况较为接近的模糊预测型线性规划模型.利用灰色预测理论对各灰色系数进行白化,将模糊预测型线性规划模型转化为模糊线性规划模型,利用最优判决条件进一步转化,得到以最大隶属度为目标函数的一般线性规划模型,求解得到了矿山的最优产能分配,以实现矿山产能的科学配置和效益的最大化.     

苯乙烯供需现状及预测

综述了国内外苯乙烯生产、消费现状,预测了未来的发展趋势。预计到2015年国内年需求量将达到1000万t。但随着亚洲和中东新装置的投产,我国苯乙烯企业将面临越来越大的挑战。     

高压大容量变频器在超临界600MW机组中的应用

采用大容量变频器对凝结水泵、闭式泵、补水泵、引风机等10台电机进行变频改造,运行安全可靠,共降低厂用电率0.5%,节能效果显著。     

低温液氨储罐的冰机选型设计

介绍了低温液氨储罐的操作工况和条件,阐述了冰机为低温液氨储罐保冷的工艺流程。详细给出了冰机吸气量、制冷量的计算公式和计算过程,介绍了冰机的型式和其他参数的确定,并通过计算结果为低温液氨储罐选择了合适的保压和保安冰机。     

丁基橡胶发展现状及发展建议

2003-2009年我国丁基橡胶需求量平均增长速率超过25%,自给率不到20%。2010年浙江信汇5万t装置投产,在一定程度将缓解市场供需矛盾,但市场缺口依然很大,预计到2014年,国内丁基橡胶总需求量达35万t。文章分析了我国丁基橡胶发展现状并提出了发展建议。     

浅谈OEM与药企发展之路

研究了OEM的发展和现状,结合国内制药企业生存现状,权衡了OEM生产方利弊,进而探讨工业化大生产中的国内制药企业面对复杂的国内外市场环境以及产能过剩的现实条件,能否将OEM作为企业生存发展的途径。     

Investigation on specific heat capacity and thermal behavior of sodium hydroxyethyl sulfonate

The thermal decomposition process was studied by the TG–DTA analyzer. The results show that the decomposition process of sodium hydroxyethyl sulfonate consisted of three stages: the mass loss for the first, the second and third stages may be about the groups of CH_3CH_2OH, CH_3CHO and SO_2 volatilized, respectively. The decomposition residuum of three stages was analyzed by FT-IR, and the results of FT-IR agreed with the decomposition process predicted by theoretical weight loss. The specific heat capacity of sodium hydroxyethyl sulfonate was determined by differential scanning calorimetry(DSC). The melting temperature and melting enthalpy were obtained to be 465.41 K and 25.69 kJ·mol~(-1), respectively. The molar specific heat capacity of sodium hydroxyethyl sulfonate was determinated from 310.15 K to 365.15 K and expressed as a function of temperature.