音频场景识别中非对称卷积和知识迁移方法研究

针对当前音频场景识别中训练数据量不足的问题,设计了基于知识迁移的非对称卷积声音场景识别系统。相较于现有方法利用音频场景识别数据集从头训练网络模型,该系统在其他任务训练好的网络模型上进行调整和训练,从而保留了源领域的有效信息。与此同时,该系统针对声学特征的特点,采用了非对称卷积模块来增强网络的特征提取能力。实验结果为该系统的准确率相较基准系统提高了0.023,并且该系统的卷积核可视化结果观察到的特征纹理更清晰。结果表明知识迁移可以提升模型的特征表示能力,与非对称卷积结合能进一步提升系统性能。     

聚酯型双键封端聚氨酯预聚物的合成及其在团状模塑料中的应用

以高附着力耐温二元醇（XC-488）、甲苯二异氰酸酯（TDI）、甲基丙烯酸羟乙酯（HEMA）为原料,合成了聚酯型双键封端的聚氨酯预聚物（HPU）,然后将不同含量的HPU与不饱和聚酯树脂、短切玻璃纤维、碳酸钙、阻燃剂等进行共混,用于团状模塑料（BMC）的制备。通过傅里叶变换红外光谱、差示扫描量热仪、力学性能、吸水率、熔体流动性、耐酸碱性、耐老化测试和扫描电子显微镜进行测试。结果表明,当HPU的含量为6 %（质量分数,下同）时,BMC复合材料的综合力学性能最好,此时复合材料的拉伸强度、弯曲强度、冲击强度分别为（47.24 ±0.42） MPa、（117.76±0.65）MPa、（33.8±0.2） kJ/m²。     

基于局部间隙状况电火花磨削周期的伺服策略

分析了现有的一些电火花磨削伺服策略存在的问题，提出了基于周期性和局部性特点的伺服策略。该策略以回转周期为控制周期，以局部间隙状况为控制的依据，通过极端局部间隙状况控制极端局部表面加工状态，从而控制整个表面优质高效的加工，具有快速修圆和一定的自动寻优功能。     

Fault diagnosis of internal combustion engines using visual dot patterns of acoustic and vibration signals

An investigation of the fault diagnosis technique in internal combustion engines based on the visual dot pattern of acoustic and vibration signals is presented in this paper. Acoustic emissions and vibration signals are well known as being able to be used for monitoring the conditions of rotating machineries. Most of the conventional methods for fault diagnosis using acoustic and vibration signals are primarily based on observing the amplitude differences in the time or frequency domain. Unfortunately, the signals caused by damaged elements, such as those buried in broadband background noise or from smearing problems arising in practical applications, particularly at low revolution, are not always available. In the present study, a visual dot pattern technique is proposed to identify the acoustic emission and vibration signals for fault diagnosis in an internal combustion engine and drive axle shaft. Experiments are carried out to evaluate the proposed system for fault diagnosis under various fault conditions. The experimental results indicate that the proposed technique is effective in the fault diagnosis of an internal combustion engine and drive axle shaft.     

材料表面技术的研究及双辉技术在防腐蚀中的应用

文章简要介绍了化学气相沉积（CVD）、物理气相沉积（PVD）、高能束表面改性及其它表面处理技术的新进展,讨论了利用双辉离子渗技术处理后碳钢对酸液的耐腐蚀性能.经双辉技术处理后的碳钢试样在稀硫酸和富液中的耐腐蚀性能显著提高.     

MoSz在空间对接摩擦材料烧结过程中的行为变化

采用粉末冶金技术制备了空间对接用铜基摩擦材料，利用X射线衍射及定量化学分析技术对MoS2在材料烧结过程中的变化行为及与其他组元之间的作用进行研究。结果表明，MoS2在加压烧结过程中存在三个方面的反应：在高温下分解成Mo和S,并造成了S元素的损失；与Cu作用形成了复杂的铜钼硫化合物；与Cu反应生成了Cu的硫化物，该类化合物具有与MoS2相类似的层状结构，有一定的润滑作用。MoS2高温分解后或MoS2与Cu反应产生的Mo元素与石墨反应形成了Mo的碳化物。另外，双飞粉的加入不仅与材料中的Mo元素作用形成CaMoO4并且改变了铜钼硫化合物、Cu的硫化物以及Mo的碳化物中各元素的麾尔比。     

The Internal Oxidation of Ternary Alloys II: The Coupled Internal Oxidation of the Two Most-Reactive Components Under Intermediate Oxidant Pressures

The kinetics of the coupled internal oxidation of the two most-reactive components in the scaling of ternary alloys under oxidant pressures below the stability of the oxide of the most noble component are examined using a number of simplifying conditions which allow to develop an approximate analytical treatment. The precipitation of the two oxides may occur either at a single front or at two different fronts of internal oxidation. The former case corresponds to a unique solution for all the parameters involved in the process. On the contrary, the existence of two fronts of internal oxidation yields a finite range of possible solutions for the oxidation kinetics as well as for all the other relevant parameters. Even though the present treatment does not allow to predict which solution will be adopted by a real system, it is possible to set limits to the values of the parameters yielding physically-acceptable solutions. After considering a general case, the treatment is applied to a real system already examined experimentally.     

利用双层辉光放电形成Mo-N硬质镀层

用双层辉光放电在钛合金Ti6Al4V表面形成了Mo-N硬质镀层。用X射线衍射仪和纳米压入仪分别对镀层的相结构、硬度和弹性模量进行了研究，并用涂层压入仪对镀层与基体间的结合强度进行了测定。结果表明：Ti6Al4V表面形成了均匀的Mo—N硬质镀层，镀层厚约10μm，由面心立方结构Mo2N化合物构成；Mo2N硬质镀层的硬度和弹性模量分别为13．80GPa和261．65GPa;镀层与基体间具有较好的结合强度。     

铸件表面合金化层性能研究

针对采用水玻璃、树脂等作为粘结剂进行铸件表面合金化时，合金层中容易产生气孔、夹渣缺陷的问题，研究了一种铸件表面合金化新工艺，即加入一种YB成型剂将合金粉末压制成块的方法进行表面合金化，在铸钢ZG65Mn本体表面得到高含Cr、W等元素的合金化层。结果表明，通过消失模铸造工艺，使用YB成型剂较好地消除了水玻璃等粘结剂造成的气孔、夹渣，合金化层和本体之间实现了冶金结合；合金化层具有较好的耐磨性和耐热性能，加入WC后耐磨性可达本体材料的4．82倍，抗氧化性能提高50％左右，且合金化粉末压块放置操作简便、可靠。     

Creep behavior and microstructure evolution of directionally solidified superalloy IC 10 at high temperature

The creep behavior of directionally solidified （DS） superalloy IC 10 was investigated under 192 MPa and 218 MPa at 980 ℃. Under the testing conditions, the marked creep characteristic of the superalloy is that the creep curve has a short primary and secondary stage and a long tertiary stage. Another creep characteristic is that the superalloy has excellent plasticity at high temperature. To study the creep behavior, the microstructure was observed by SEM and TEM. Different from other microstructure of Ni-base superalloys, superalloy IC10 forms incompletely rafted γ＇ phase during the creep processes. To understand the creep deformation mechanism of superalloy IC10, the movement of dislocations was analyzed. The results show that the dislocations moving in the γ matrix and climbing over the γ＇ precipitates is the main deformation mechanism under the experimental conditions.