圆锥滚动轴承外圈制造工艺改进

圆锥滚动轴承的套圈是重要的承载部件,对轴承的性能有着重要的影响。圆锥滚动轴承的套圈大都采用传统的热锻造加工工艺,这种工艺存在很多缺点,影响轴承的性能。文中讨论了一种冷辗扩成形工艺,能有效地节省材料和能耗,提高套圈精度,从而提高轴承的使用寿命。     

一种基于LPFG高灵敏度浓度传感器

利用Sagnac光纤环全反射的特性和单根长周期光纤光栅(LPFG)构成Michelson干涉仪,入射光经LPFG后,部分被耦合到包层中传输,经过包层和纤芯传输的光信号经Sagnac光纤环全反射后重新耦合回LPFG,在光栅区域干涉。利用传输矩阵理论分析了干涉结构的光谱特性。用此干涉结构检测了蔗糖溶液浓度,传感灵敏度可达0.065 nmLg-1。     

Electromagnetic Modeling of Quasi‐Square Open Metallic Ring Frequency Selective Surface Using Wave Concept Iterative Procedure

The wave concept iterative procedure (WCIP) is used to analyze a quasi‐square open metallic ring frequency selective surface (FSS). The quasi‐square open metallic ring FSS is dual‐polarized. When the incident plane wave is polarized in a direction parallel to the FSS’ coupled parallel strips, it shows two rejecting bands. Moreover, another rejecting band can be obtained if the source plane wave is perpendicularly polarized with respect to the FSS’ coupled parallel strips. The three resonant frequencies are inversely proportional to the length of the FSS’ coupled strips to provide an easy fine tuning of the FSS structure. The simulated results obtained using WCIP are compared to the measured results, and a good agreement is reported.     

一种混合防腐技术在水环真空泵上的应用

从技术经济角度出发,对耐腐蚀水环真空泵过流零件表面处理的现状及各工艺方案的特点进行了分析,提出了能够满足使用需要的混合防腐工艺方案,达到使用寿命延长,防腐成本降低。     

基于湖泊保护的环湖路规划与控制——以武汉市中心城区湖泊保护三线规划为例

针对湖泊水体不断被城市开发建设侵蚀、湖泊面积不断缩小等现象,武汉市中心城区湖泊保护三线规划通过界定蓝线、确定绿线和划定灰线的控制范围指导城市湖泊水体周边地区的开发建设,采取分级控制体系,对已建区.发展区和生态控制区三个不同地区的湖泊提出不同的环湖路控制模式,将环湖路的规划控制与湖泊保护相结合,不仅改变了无序开发的现象,还进一步强化了对湖泊水体、岸线的管理,提升了湖泊岸线的景观功能.     

New Indenylidene‐Schiff Base‐Ruthenium Complexes for Cross‐Metathesis and Ring‐Closing Metathesis

We here report on the stability and catalytic activity of new indenylidene‐Schiff base‐ruthenium complexes 3a – f through representative cross‐metathesis (CM) and ring‐closing metathesis (RCM) reactions. Excellent activity of the new complexes was found for the two selected RCM reactions; prominent conversion was obtained compared to the commercial Hoveyda–Grubbs catalyst 2 . Moreover, excellent results were obtained for a standard CM reaction. Higher conversions were achieved with one of the indenylidene catalysts compared with Hoveyda–Grubbs catalyst. Unexpectedly, an isomerization reaction was observed during the CM reaction of allylbenzene. To the best of our knowledge, isomerization reactions in this model CM reaction in closed systems have never been described using first generation catalysts, including the Hoveyda–Grubbs catalyst. The first model CM reactions as well as the RCM reactions have been monitored using ¹H NMR. The course of the CM reaction of 3‐phenylprop‐1‐ene ( 8 ) and cis‐1,4‐diacetoxybut‐2‐ene ( 9 ) was monitored by GC. The isomerization reaction was studied by means of GC‐mass spectrometry and in situ IR spectroscopy. All catalysts were structurally characterized by means of ¹H, ¹³C, and ³¹P NMR spectroscopy.     

国家体育场空间顶环梁施工技术

国家体育场看台共分三层,通过环梁将混凝土结构柱、钢管混凝土柱和上层看台斜梁连接在一起。形成上层看台结构体系,环梁随斜梁端头起伏呈马鞍形。由于看台结构层层外挑,环梁支撑、定位、配模施工难度很大,对此采取针对性措施,快速精确地完成了该空间环梁的施工。     

试述定襄县三环路景观设计方案

以定襄县三环路景观设计为例,对道路景观的空间规划、特殊功能作了简要分析,并对道路景观设计理念、总体布局、设计构思及植物种植等进行了重点阐述,从而创造出一个独特亮丽的绿色道路景观。     

南水北调工程中碱—骨料反应的问题及防治

结合南水北调工程,介绍了混凝土碱—骨料反应机理和特点,详细阐述了抑制碱—骨料反应的具体措施和方法,并指出抑制碱—骨料反应需注意的几点问题,以及施工过程中应注意的事项,以期杜绝碱—骨料反应给工程带来的危害。     

广州地铁六号线3标段盾构管片设计关键技术

通过对广州地铁六号线盾构3标段管片设计、选型及施工的研究,论述了在盾构隧道曲线段的通用环管片和左右转管片的楔形量、转弯能力计算方法和设计技术,该文提供的设计计算方法对类似工程的管片设计具有参考价值。