复合桩墙锚支护技术在深基坑中的应用

针对传统的支护结构土压力计算存在的缺陷,介绍了一种新型复合桩墙支护技术和特点,当基境支护深度较大或需对基坑及周围环境变形进行严格控制时,可对桩墙顶部采用预应力斜锚、桩墙中部采用锚杆、预应力锚杆等技术配合支护,具有止水挡土双重作用,介于刚性重力式档墙和柔性悬壁桩墙间的一种属半刚性、半柔性支护结构.实例结果表明,该支扩经济实用,有较高的推广应用价值.     

488天然气发动机的模拟计算

拟将一台CA4G22汽油机改为天然气专用发动机，为此对不同的技术方案进行了模拟计算。计算结果表明，采用增压中冷稀燃方案与理论空燃比方案相比，可以取得很好的动力性与经济性。     

Effect of Sm on the cyclic stability of La–Y–Ni-based alloys and their comparison with RE–Mg–Ni-based hydrogen storage alloy

The LaY₂Ni_9.7Mn_0.5Al_0.3 and LaSm_0.3Y_1.7Ni_9.7Mn_0.5Al_0.3 alloys have been synthesized to investigate the effect of Sm partial substitution for Y on the cyclic stability of A₂B₇-type La–Y–Ni-based alloys. Their cyclic properties were also compared with the A₂B₇-type (RE_0.85Mg_0.15)₂(NiAl)₇ (RE = Rare Earth) alloys. The gas-solid and electrochemical cycle lives were tested. The structural stability, pulverization, and oxidation/corrosion performances were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical methods. The partial substitution of Sm for Y improves anti-corrosion and anti-pulverization performances, thereby increasing the cycle life of A₂B₇-type La–Y–Ni-based hydrogen storage alloys. The A₂B₇-type RE–Y–Ni-based alloys exhibit better crystal structure stability, but the gas-solid and electrochemical cyclic stability is worse than A₂B₇-type (RE_0.85Mg_0.15)₂(NiAl)₇ alloys due to easier pulverization of particles and the oxidation of Y elements.     

Influence of metal oxide on LiBH4/2LiNH2/MgH2 system for hydrogen storage properties

In this study, various nanoscale metal oxide catalysts, such as CeO₂, TiO₂, Fe₂O₃, Co₃O₄, and SiO₂, were added to the LiBH₄/2LiNH₂/MgH₂ system by using high-energy ball milling. Temperature programmed desorption and MS results showed that the Li–Mg–B–N–H/oxide mixtures were able to dehydrogenate at much lower temperatures. The order of the catalytic effect of the studied oxides was Fe₂O₃ > Co₃O₄ > CeO₂ > TiO₂ > SiO₂. The onset dehydrogenation temperature was below 70 °C for the samples doped with Fe₂O₃ and Co₃O₄ with 10 wt.%. More than 5.4 wt.% hydrogen was released at 140 °C. X-ray diffraction indicated that the addition of metal oxides inhibited the formation of Mg(NH₂)₂ during ball milling processes. It is thought that the changing of the ball milling products results from the interaction of oxide ions in metal oxide catalysts with hydrogen atoms in MgH₂. The catalytic effect depends on the activation capability of oxygen species in metal oxides on hydrogen atoms in hydrides.     

用计算机辅助创新软件解决产品技术创新问题的研究

本文简要介绍了发明问题解决理论TRIZ和机算机辅助创新软件Pro/Innovator的主要内容,建立了基于创新理论TRIZ和CAI软件的创新问题解决流程模型,作为特例建立了Pro/Innovator1.0的简化流程图,最后用软件完成了一个工程实例问题的创新设计.     

柴油机喷油泵接头疲劳寿命的有限元分析

为查找某型柴油机喷油泵接头疲劳失效的原因,利用有限元软件ANSYS和FE-SAFE相结合的方法,开展了表面粗糙度对零件疲劳寿命及疲劳安全系数影响的研究分析,并与试验结果进行了比较。分析结果表明,计算结果与试验检测结果较为一致,零件表面的粗糙度等级对其疲劳寿命的影响很大,在设计时应予充分考虑。分析结果可为表面设计及加工工艺改进提供参考依据。     

Research on the hot surface ignition of hydrogen‐air mixture under different influencing factors

To further reveal the pre‐ignition characteristics of hydrogen internal combustion engine, the effect of hot surface characteristic parameters on the ignition characteristics of hydrogen‐air mixture was investigated in this research. Based on the prototype of the constant volume combustion bomb with an overhead glow plug, the duration from the heating of the hot surface to the combustion of hydrogen‐air mixture, the so‐called heating duration, was firstly researched under different fuel‐air equivalence ratio, initial temperature, initial pressure, hot surface temperature, and hot surface area, and the influence of each factor on the heating duration was analyzed. The results show that the order of the effect of each factor on the hot surface ignition is as follows: hot surface temperature > initial pressure of hydrogen‐air mixture > equivalent ratio > initial temperature of hydrogen‐air mixture > hot surface area. The influence of the hot surface characteristic parameters on the heating duration was further analyzed in detail. On this basis, the relationship among the critical ignition temperature, the heating duration and the hot surface area was researched and established. The results show that the heating duration is the only major factor affecting the critical ignition temperature. Finally, the research results were applied to analysis the pre‐ignition in hydrogen internal combustion engine.     

马斯京根模型参数抗差估计方法风险分析

针对马斯京根模型参数抗差估计方法存在将真实值作为异常值的风险,利用蒙特卡洛方法分析了不同频率、不同量级的异常值影响下马斯京根模型参数抗差估计方法风险与效果间的关系。结果表明,马斯京根模型参数抗差估计方法的风险随异常值量级和频率的减小而增大,同时还与估计方法选取的抗差权函数有关。     

基于和谐论的水资源管理模型及应用

有效管理水资源,提高水资源利用率,是经济社会与资源环境和谐发展的必然要求。将和谐论引入到水资源管理中,基于水资源管理的系统、区域、部门三个管理层次,构建了水资源管理量化指标体系;并以水资源管理和谐度最大为目标函数、各层次的管理因素为约束条件,建立了基于和谐论的水资源管理模型,以新密市为例对所建模型进行了应用研究。结果表明,该模型为评价水资源管理在系统、区域和部门层次的管理水平提供了定量分析方法。     

氧传感器参考电平自适应空燃比闭环控制方法研究

为了解决开关式氧传感器空燃比闭环控制点的漂移问题，建立了开关式氧传感器闭环控制的数学模型，并分析了氧传感器信号参考电平对空燃比闭环控制的影响，据此，提出了氧传感器参考电平自适应空燃比闭环控制方法，在发动机上试验了氧传感器参考电平对空燃比的影响规律，并进行了氧传感器参考电平的优化试验，结果表明，氧传感器参考电平自适应控制方法可以有效避免空燃比闭控制点随发动机工况变化的漂移问题，有效地降低了汽油机的排放。