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11.
论述了高压蓄势器气体绝热膨胀过程的判别条件及气罐容积的设计计算方法。由于考虑到了常温高压条件下实际气体和理想气体之间的差别,所以其方法更加符合实际,结果更加准确。  相似文献   
12.
手动控制小型水轮机水门开张角度,不能针对水势及时、准确地调整水门,无法实现水资源充分利用且不宜于无压引水溶洞的维护.基于以上问题提出智能化控制系统,实现水文自动监控和远程自动控制,从而实现发电系统的最优化运行.  相似文献   
13.
The grain size and precipitate amount which are affected by heat treatment have significant impact on the properties of high nitrogen austenitic stainless steel. In this study, Cr18Mn18 high nitrogen steel sheet is employed to investigate the effects of precipitate on austenitic grain size. It can be seen that the lamella precipitates which are rich in nitrogen and chromium nucleate in the austenite grain boundary and grow inward into grain when aged at 800 ℃ through electron probe micro-analyzer. The transmission electron microscopy results demonstrate that the precipitate is Cr2N and its morphology are detected as ellipsoid-like with major axis of 100-300 nm and minor axis of 50-100 nm roughly. The experiment show that coarsen of the austenite grain is quite critical at 1000-1100 ℃. However, the samples which pre-precipitated at 800 ℃ for 240 min to obtain the most nitride precipitate exhibits much smaller grain size than the as-rolled samples after solid solution treated at 1000, 1050 and 1100 ℃ for 240 min. The results show that the nitride precipitates in the grain boundary can effectively pin the austenite grain boundary and inhibit the grain growth.  相似文献   
14.
裂纹扩展抗力是材料的内在属性,Paris的重要贡献是将ΔK引入疲劳裂纹扩展的研究,表明疲劳裂纹扩散的控制参数是应力强度因子ΔK。本试验异种焊接接头采用钨极氩弧焊(TIG)进行打底焊接,而后采用埋弧自动焊进行多层多道焊接,焊后进行相应的回火处理,之后随炉自然冷却。实验材料为9Cr钢母材、Cr Mo V母材和两侧的热影响区及焊缝区。按照降K法进行测试,应力比分别设定为0.5、0.7、0.9,在近门槛值区域进行多次测量,通过线性回归法拟合出直线方程,由此计算出疲劳扩展门槛值,可反映该焊接条件下9Cr与Cr Mo V异种材料接头的疲劳裂纹扩展行为。  相似文献   
15.
This contribution mainly studied the preparation of hyperbranched polyethylene (HBPE) fibers and HBPE/multiwalled carbon nanotube (MWCNT) composite fibers via electrospinning for the first time. Firstly, the effects of solvents, solution concentration, voltage, and rotating speed of collector on the morphology of HBPE fibers were studied. Among the factors, solvent type, concentration, and voltage showed notable influence on the morphology of HBPE fibers. HBPE has an excellent dispersion effect on CNT in organic solvents. Through ultrasonic dispersion, the HBPE solutions with dispersed MWCNT were obtained. Then HBPE/MWCNT composite fibers were obtained with different contents of MWCNT via electrospinning. The effects of voltage and working distance on the morphology of HBPE/MWCNT composite fibers were investigated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42517.  相似文献   
16.
介绍了 8 7dtex/ 72f涤纶细旦POY生产过程 ,通过调整和优化生产工艺 ,如控制切片质量、纺丝温度、侧吹风速度及温度、上油率、卷绕速度等 ,在常规熔融纺丝设备上可生产出优质涤纶细旦POY。  相似文献   
17.
为了研究钢筋混凝土两跨连续梁在火灾和集中荷载作用下的力学性能,基于钢筋混凝土梁截面平衡条件提出了一种双筋矩形截面梁在火灾高温作用下的截面抗弯刚度计算方法,并应用于钢筋混凝土连续梁内力的计算.根据力学原理和材料高温特性对恒载升温条件下的钢筋混凝土两跨连续梁的内力重分布和变形全过程进行了弹塑性分析,所得结果与试验值吻合较好...  相似文献   
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19.
介绍了武钢生产的铁路车辆用耐候钢的特点,分析稀土对Cu—P系列耐候钢的作用机理,并介绍武钢正在开发的耐候钢新钢种。  相似文献   
20.
In this article, a functional ferrocene-based metalloligand has been synthesized and used as the building block to assemble novel coordination polymer microspheres. Specifically, this metalloligand was coordinated with two different types of metal ions (Co2+ and Mn2+) to fabricate two different but isostructural microspheres under solvothermal conditions. To deepen our understanding of the formation process of the coordination polymer microspheres, a growth mechanism has been proposed based on the morphology change of these spheres throughout the whole reaction process. Furthermore, the prepared multi disperse microspheres, in the form of hollow spheres with high thermostability, can be applied to store hydrogen for their promising hydrogen uptake capacity (1.84wt% for CPM-1 and 1.00 wt% for CPM-2 at 163 K under 5 MPa). Moreover, the different adsorption enthalpies of these two materials that relevant to the varied hydrogen uptake capacity have been calculated, compared and explained.  相似文献   
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