脉冲偏压对电弧离子镀TiNbN硬质薄膜相结构的影响

用电弧离子镀设备,在其他工艺参数相同的条件下,通过仅改变脉冲偏压幅值的方法分别沉积TiNbN硬质薄膜,考察脉冲偏压对薄膜相结构的影响.结果表明,TiNbN硬质薄膜的相结构随脉冲偏压幅值的变化而变化:当幅值为-300 V时,得到TiN类型的(TiNb)N的固溶体;-600 V时,得到TiN和δ-NbN的混合相结构;而在-900 V时,则得到TiN和δ-NbN以及β-Nb2N三相混合结构.分析表明,脉冲偏压能够改变薄膜相结构,这与不同偏压提供的离子沉积能量,能够分别满足各个化合物生成自由能的热力学条件有关.     

重载包装木箱端板结构分析

比较重载包装木箱端板的原有设计与加入斜挡的改进设计的端板结构受力分析,通过计算,改进后的端板结构端梁抗弯强度提高12倍,端面角立柱的抗压强度提高3倍,有效提高了重载包装木箱承载能力.     

一种基于光三角法的激光测振仪

介绍了一种基于光三角法的激光非接触测振仪,对激光测振仪的结构参数的优化设计进行了分析。研制的激光测振仪的主要技术参数为工作距离 ４０ｍ ｍ ～２ｍ ,测量范围 ２～５０ｍ ｍ ,测量分辨力 ２～２０μｍ ,频率响应 ０～３ｋ Ｈｚ。     

Rational Design of Three‐Layered TiO2@Carbon@MoS2 Hierarchical Nanotubes for Enhanced Lithium Storage

Here we demonstrate the rational design and synthesis of three‐layered TiO₂@carbon@MoS₂ hierarchical nanotubes for anode applications in lithium‐ion batteries (LIBs). Through an efficient step‐by‐step strategy, ultrathin MoS₂ nanosheets are grown on nitrogen‐doped carbon (NC) coated TiO₂ nanotubes to achieve the TiO₂@NC@MoS₂ tubular nanostructures. This smart design can effectively shorten the diffusion length of Li⁺ ions, increase electric conductivity of the electrode, relax volume variation of electrode materials upon cycling, and provide more active sites for electrochemical reactions. Owing to these structural and compositional features, the hierarchical TiO₂@NC@MoS₂ nanotubes manifest remarkable lithium storage performance with good rate capability and long cycle life.     

阳离子分布对尖晶石型热敏陶瓷电性能的影响

以高温固相反应法合成了Mn3 -xNixO4( 0 .5≤x≤ 1 .0 )和Mn3 -x -yNixCuyO( 0 .5≤x≤ 1 .0 ;0≤y≤ 0 .5 )材料 ,用XPS和XRD手段对尖晶石结构中存在的阳离子价态和分布情况进行了研究。指出随Ni含量的变化 ,Ni占据A位的比例w为 :w =5 49.6×e-2 .85 174x 并探讨了阳离子分布对电性能的影响。同时指出在Mn3 -x -yNixCuyO材料中存在着占据B位的Cu+,Cu+的出现使得B位相应产生了大量的可引起跳跃电导的Mn4+,且产生了第二种跳跃电导机制 :Cu+oct+Mn+oct→Cu2 +tet +Mn3 +oct 。这一发现可以成功解释该系材料的电导率和热老化系数比未掺杂Cu的同类材料高得多的原因。     

玻璃料对可陶瓷化硅橡胶基复合材料耐高温性能的影响

玻璃料可以改善可陶瓷化硅橡胶基复合材料高温热解后的力学强度,保持结构的完整性。为了研究玻璃料的成分对云母/硅橡胶复合材料耐高温性能的影响,分别以玻璃料A和B为助熔剂,制得了2种复合材料,研究了其力学性能、微观形貌、热分解性能及陶瓷化机制。结果表明:云母/硅橡胶复合材料常温拉伸强度为3~4 MPa,600~1 200℃下热解后试样的弯曲强度在0.3~4.5 MPa之间,且保持结构完整;SEM结果显示玻璃料B有助于形成大量的液相结构,更好地改善热解后形成的陶瓷层的强度和结构;TG结果显示玻璃料可以加速硅橡胶的分解,因此要控制玻璃料的加入量;XRD结果显示在温度变化过程中,添加含SiO₂和K₂O成分较多的玻璃料B至云母/硅橡胶复合材料中形成了非晶相和钾长石（K₂O·Al₂O₃·6SiO₂）,从而提高陶瓷层的强度。      

A comparative study of fatigue estimation methods for single‐spot and multispot welds

Fatigue life and load data of spot‐welded samples were obtained by performing tensile‐shear fatigue tests on single‐spot‐welded samples, and by collecting published data on tensile‐shear fatigue tests of multispot‐welded samples. Finite element models of the spot‐welded samples were then constructed, and their accuracy was validated by comparing their results with those of static loading tests. Methods to estimate fatigue in spot‐welded joints proposed by Sheppard, Rupp, and Swellam were used to predict the fatigue life of each sample, and their results were compared. The sensitivity of each method to spot‐welding parameters, as well as the arrangement and number of welded spots, was analyzed to obtain their scope of applicability. Finally, the Sheppard and Rupp methods were used to obtain fitted fatigue curves of each spot‐welded sample, and the equivalent life method was used to generate P‐S‐N curves of the single‐spot‐ and multispot‐welded samples. This method can serve as a useful reference for fatigue reliability analyses of mechanical parts with spot‐welded joints.     

室内热湿环境仿真软件开发

建筑室内热环境仿真软件已成为室内环境研究的重要手段之一.在VB.NET开发平台下,采用高效的计算语言Visual Fortran与Visual Basic混合编程,开发了一套界面友好、计算速度较快、计算结果可视化的建筑室内热环境仿真软件Indoor Thermal Environment Simulation (ITES),并在重庆大学热环境实验室进行了实验,对特定热湿环境下的室内温度分布进行测试,其测试结果与ITES软件的模拟结果相一致.验证了ITES软件对建筑室内热环境仿真模拟的可信性.