基于分布式虚拟现实技术的汽车驾驶模拟器的研究

介绍了正在研制的基于分布式虚拟现实技术的汽车驾驶模拟器。这是一个基于虚拟现实环境和网络环境的软硬件集成系统。重点研究视觉系统，包括外景系统和驾驶内景。对有关建模技术中的基于NLTRBS曲面法线的路面纹理(含路标线等)自动校准和生成技术、基于高程的多重纹理映射生成技术、模型和纹理的无缝切片技术和基于物理特性的环境仿真试验与交互技术进行了研究。给出了该汽车虚拟仿真驾驶系统在选择车辆、选择天气状况和时间以及选择各种路况等的示例。     

低成本VN微合金化HRB400热轧钢筋的生产试制和综合性能分析

济源钢铁公司采用添加钒氮合金生产的HRB400钢筋，具有强度高、焊接性能好的优点，达到一级抗震要求；和以前使用钒铁生产HRB400钢筋的工艺相比，生产成本大幅降低。     

低碳Cr-Mn-Si-Mo空冷贝氏体钢力学性能的研究

以A3钢、硅铁、锰铁、铬铁及钼铁为原料,冶炼成无缺口的冲击试样.试样经过奥氏体化后空冷处理,分别测试了铸态及空冷处理后试样的洛氏硬度、冲击韧性,并在Olympus和扫描电子显微镜（SEM）下观察了其组织形态与断口.试验结果表明,试样经920℃奥氏体化后空冷得到较好的硬度与冲击韧性的匹配,硬度为HRC31.0,冲击韧性为200.775J/cm^2,金相组织以粒状贝氏体为主,含有少量的残余奥氏体.     

加气混凝土应用中存在的问题与对策研究

加气混凝土作为一种新型的墙体填充材料，具有容重小、强度低、吸水率高、收缩性大等优点．目前，由于工程应用中存在空鼓、开裂、剥落和墙体收缩裂缝等施工质量问题，在很大程度上限制了加气混凝土材料的发展与应用．为此，应采取提高混凝土的表面性能，加强砂浆与加气混凝土的粘结等施工措施加以解决．     

CNa42+团簇的结构及其储氢性能研究

氢是一种理想的二次能源,它将成为化石燃料最有希望的替代能源之一,也是亟待开发的重要能源。而氢能的储存成本高,危险性大是急需解决的问题。理论上预测CNa_4~(2+)的储氢性能,通过理论分析,发现了每个CNa_4~(2+)团簇最多可与16个H2分子有效结合,获得23.5%的质量储氢密度。在B3LYP理论水平上,H2分子与CNa_4~(2+)团簇的平均相互作用能在2.107～4.948Kcal/mol之间。由于CNa_4~(2+)的质量储氢密度在7.1～23.7wt%之间,符合美国能源部的要求目标(5.5 wt%)。研究结果表明,CNa_4~(2+)在一定环境条件下可逆吸放氢性能良好,可作为潜在的理想高容量储氢材料。     

微量镍元素添加对铁基非晶/纳米晶磁芯软磁性能的影响

用单辊法制备的宽20 mm,厚25μm的Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9和Fe_(73.5)Ni_(0.3)Cu_1Nb_3Si_(14.2)B_8合金带材,绕制成外径为40 mm,内径为25 mm的环型磁芯,然后将磁芯在不同的温度下进行退火处理,研究了微量Ni元素添加对合金带材的晶化行为以及对横向磁场退火后的非晶/纳米晶磁芯的软磁性能的影响。结果表明:与Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9合金带材相比,添加微量Ni元素的Fe_(73.5)Ni_(0.3)Cu_1Nb_3Si_(14.2)B_8合金带材的一级起始晶化温度Tx1和一级晶化峰温度Tp1降低,其二级起始晶化温度Tx2和二级晶化峰温度Tp2升高,两级起始晶化温度之间的差值ΔTx增大;与横向磁场退火后的Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9非晶/纳米晶磁芯相比,横向磁场退火后的Fe_(73.5)Ni_(0.3)Cu_1Nb_3Si_(14.2)B_8非晶/纳米晶磁芯的起始磁导率μi和饱和磁感应强度Bs减小,矫顽力Hc增大;当测试频率f和最大磁感应强度Bm不变时,有效幅值磁导率μa增大,比总损耗Ps和矫顽力Hc减小;当测试频率f不变时,电感Ls和品质因数Q增大;当励磁电流I不变时,感应电动势E大。     

角膜生物力学特性研究进展

 角膜的光学功能与其形态结构紧密相联,角膜形态的异常可导致近视、远视、圆锥角膜等眼部疾病。细致研究角膜的力学特性,建立有临床用途的生物力学模型已成为一个重要研究领域。本文以首都医科大学眼生物力学研究团队的研究工作为基础,综述在角膜力学特性研究中的实验测试方法和本构参数获取方法等方面的进展。     

Nanoindentation response analysis of TiN-Cu coating deposited by magnetron sputtering

To investigate the change of the mechanical properties of soft metals doped PVD(Physical Vapor Deposition)coatings after the migration of soft metal to the surface, TiN-Cu coating was deposited on Si(100) by magnetron sputtering. The microstructure and mechanical properties at room temperature and after vacuum heat treatment at 300 ℃ were investigated. The results showed that the grains were clustered and the microstructure was porous for TiN-Cu coating at room temperature, while many micro-and nano-sized Cu particles were observed on the surface after vacuum heat treatment at 300 ℃. The elastic properties of the TiN-Cu coating after vacuum heat treatment at 300℃ degraded compared with that at room temperature. The hardness and elasticity modulus of TiN-Cu coating kept constant(3.7 GPa and 125.0 GPa, respectively) with the increase of nano-indentation depth, while the hardness and elasticity modulus of TiN-Cu coating after vacuum heat treatment at 300 ℃ increased gradually.     

Effect of minor Sc on the microstructure and mechanical properties of AZ91 Magnesium Alloy

The as-cast and heat-treated microstructures and mechanical properties of the AZ91 magnesium alloys with and without minor Sc addition were investigated and compared in this paper. The results indicated that adding0.15–0.45 wt% Sc to the as-cast AZ91 alloy not only could modify and refine the Mg_(17)Al_(12) phase but also suppress the formation of the Mg_(17)Al_(12) phase. At the same time, the grains of the Sc-containing as-cast AZ91 alloys were also effectively refined. As a result, the mechanical properties at room temperature(RT) for the Sccontaining as-cast AZ91 alloys were effectively improved. In addition, adding 0.15–0.45 wt%Sc to the AZ91 alloy promoted the formation of the continuous precipitates(CP) during the aging treatment in spite of that the formation of the discontinuous precipitates(DP) was simultaneously suppressed. Accordingly, the Sc-containing as-aged AZ91 alloys obtained the relatively higher mechanical properties at RT than the as-aged AZ91 alloy.     

Influence of minor boron on the microstructures of a second generation Nibased single crystal superalloy

Boron is added into single crystal superalloys as a micro-alloying element to strengthen low angle grain boundaries.However,systematic investigations on the effect of boron on microstructures of single crystal superalloys are limitedly reported.The effect of boron on as-cast and heat-treated microstructures was investigated in two experimental Ni-based single crystal superalloys containing 3 wt% Re.The current results indicated that the volume fraction of(γ+γ′)eutectic and M_3B_2 borides was evidently increased,while the number of micropores was evidently decreased with the addition of 0.02 wt% boron.The(γ+γ′)eutectic could not be dissolved completely due to the lower incipient melting temperature caused by the formation of M_3B_2 borides.Meanwhile,the M_3B_2 borides were found to be enriched with indispensable strengthening elements Cr,Mo,W and Re,and this may lower the strengthening effect and cause stress concentration during high temperature creep.