理工科大学双语教学的探讨

本文结合自己出国留学的亲身经历，从双语教学的内涵及国内外发展出发说明了理工科大学只有推行双语教学才能为国家培养面向现代化、面向未来、具有国际竞争力的新世纪优秀人才。讨论了双语教学过程中中文与英文、双语教学与强化英语教学以及专业英语与双语教学等之间的关系。最后在理论与实践相结合的基础上提出了理工科大学推行双语教学的七大对策。     

论现阶段我国政府与高校的角色定位及其关系调整

新中国成立后，我国政府集举办者，管理者，办学者于一身，高校几乎是政府的行政附属物，政府与高校的关系主要是以行政行为和直接控制为主的隶属关系，市场经济体制的确立，对这种角色定位及关系提出了严峻挑战。因此，现阶段必须分化与重塑政府角色，归位与调适高校的角色，重新调整两者的关系。     

On the induction plasma deposition of tungsten metal

The central particle injection and long residence time characteristics of induction plasma have given rise to the complete melting of tungsten particles injected into an Ar- H₂ plasma under soft vacuum conditions. The influences of process variables such as power level, chamber pressure, and spray distance on splat morphology, apparent density, and deposition efficiency have been studied. Dense tungsten deposits with no oxidation have been obtained. Scanning electron microscopy (SEM) micrographs reveal a well-flattened lamellar structure in deposits. Radiative cooling is observed to play a significant role in the plasma spraying of this refractory metal.     

激光熔覆MoS2/TiC/Ni减摩耐磨复合涂层组织及磨损性能的研究

以MoS2、TiC、Ni粉为原料,在20钢基材表面利用激光熔覆技术制备了减摩耐磨复合涂层.采用SEM和XRD对复合涂层的组织和相组成进行了研究,结果表明复合涂层主要由部分未熔的TiC颗粒、Mo2C、γ镍基固溶体和多种两元、三元硫化物TiS、NiS、Ni3Ti4S8等组成.用FALEX-6摩擦磨损实验机对MoS2/TiC/Ni复合涂层、MoS2/Ni激光熔覆层以及45钢的耐磨性能进行了对比,并对三种试样表面的磨损形貌进行了SEM观察.实验表明:MoS2/Ni激光熔覆层具有最低的摩擦系数,但磨损失重最大;MoS2/TiC/Ni复合涂层在载荷17.8N、转速200r/min条件下,磨损40分钟,其磨损失重仅为45钢的1/6.     

Bio-mimetic surface structuring of coating for tribological applications

A novel multilayered coating was developed for applications associated with friction reduction and wear resistance improvement. The nano-engineered coating integrates a soft lubricating layer, consisting of MoS₂-PTFE, onto hard load-supporting layers, with controlled surface morphology (roughness and patterning) of cBN-TiN. The coating was synthesized by sequential procedures including electrostatic spray deposition of cBN particles with different average particle sizes, chemical vapor deposition of TiN, deposition of nano- and micro-sized MoS₂ dispersed in PTFE, and curing. The effect of cBN particle size (with different combinations of particle size) and deposition parameters (specifically electrical voltage) on the cBN-TiN surface morphology were studied experimentally and optimized. SEM characterization of the as-synthesized cBN-TiN coating shows surface features similar to that of colocasia esculenta, with alternating nano- and micro-sized domes and “pockets”; the MoS₂-PTFE top layer has MoS₂ particles retained in the pockets by a basket structure formed during PTFE curing. Tribological and scratch tests were carried out for the as-prepared cBN-TiN and cBN-TiN/MoS₂-PTFE multilayered coatings. Sliding test results demonstrate significantly lower friction coefficient for the multilayered coating, showing that the unique integration of soft lubricating layer and biomimetically structured hard layer can effectively improve tribological performance. It is suggested that lubrication at the frictional contacts was realized by continuous release of the lubricants, MoS₂ and PTFE, from the pockets.     

热处理对高铬铸铁轧辊组织和性能的影响

研究了淬火温度、淬火冷却方式和回火温度对高铬铸铁轧辊组织和性能的影响.结果表明,油冷条件下,淬火温度低于1000℃,随着淬火温度升高,硬度升高,随后硬度反而下降,雾冷和空冷条件下,淬火温度对硬度的影响规律与油冷时相似,获得最高硬度的淬火温度超过油冷时的淬火温度,达到1025℃.回火温度低于500℃时,高铬铸铁轧辊硬度变化不明显,超过575℃,硬度明显下降,高铬铸铁轧辊在450℃回火4小时,具有良好的综合力学性能和优异的耐磨性.     

宏指令编程在函数方程曲线加工中的应用

讨论了应用宏指令编程的普通数控机床上准确加工函数方程曲线的方法；给出了几种相应的算法和一个编程实例。该方法大大简化了此种零件加工程序的编制，经华中Ⅰ型数控铣床实际应用，效果良好。     

φ50mm穿孔机后台架的改进

运用力学方法建立了穿孔机后台架的力学模型，导出了顶杆挠度曲线方程，给出了顶杆临界压力及顶杆长度之间的关系式，为穿孔机后台架的改进提供了理论依据。     

变粘度条件下静压支承滑靴副的理论研究

本文对变粘度条件下的静压支承滑靴副进行了一定的理论研究和分析，通过计算机仿真，得出了滑靴副泄漏流量和支承反力不仅与中心油室压力有关，而且还与流体的粘温系数、粘压系数、密度和比热容等有关的结论，为高速高压轴向柱塞泵的设计提供了一定的理论依据。     

Fe掺杂对Bi2Sr2Co2Oy热电性能和自旋关联的影响

采用固相合成法制备出系列Fe掺杂的Bi2Sr2Co2Oy，样品，并对样品进行XRD分析，电阻率（p）、热电势（固和顺磁共振研究。结果表明：Fe掺杂浓度x≤0．3时样品基本为单相。Fe掺杂使体系的电阻率略微增大，热电势显著升高，这可能与Fe掺杂降低了空穴载流子浓度有关。Fe掺杂浓度x=0．05样品获得最大的功率因子（power factor，S^2／P）。顺磁共振结果显示，不掺Fe的样品有着较强的顺磁共振（ESR）信号，随着Fe含量的增加，ESR信号向低频方向移动，并逐渐宽化减弱直至消失。这表明Fe掺杂改变了体系的自旋关联状态，占据了Co位参与了Co—O—Co之间的自旋关联。研究结果表明合适的元素掺杂可以有效地调整体系的自旋关联状态，改善材料的热电性能。