YSZ/MoS2 self-lubricating coating fabricated by thermal spraying and hydrothermal reaction

Thermal sprayed ceramic coatings have extensively been used in components to protect them against friction and wear. However, the poor lubricating ability severely limits their application. Herein, yttria-stabilized zirconia (YSZ)/MoS₂ composite coatings were successfully fabricated on steel substrate with the combination of thermal spraying technology and hydrothermal reaction. Results show that the synthetic MoS₂ powders are composed of numbers of ultra-thin sheets (about 7 ~ 8?nm), and the sheet has obvious lamellar structure. After vacuum impregnation and hydrothermal reaction, numbers of MoS₂ powders, look like flowers, generate inside the plasma sprayed YSZ coating. Moreover, the growing point of the MoS₂ flower is the intrinsic micro-pores of YSZ coating. The friction and wear tests under high vacuum environment indicate that the composite coating has an extremely long lifetime (>?100,000 cycles) and possesses a low friction coefficient less than 0.1, which is lower by about 0.15 times than that of YSZ coating. Meanwhile, the composite shows an extremely low wear rate (2.30?×?10^?7 mm³ N^?1 m^?1) and causes slight wear damage to the counterpart. The excellent lubricant and wear-resistant ability are attributed to the formation of MoS₂ transfer films and the ultra-smooth of the worn surfaces of hybrid coatings.     

Tuning effect of silicon substitution on magnetic and high frequency electromagnetic properties of R2Fe17 and their composites

In this work, we report the tuning effect of the Si substitution on the magnetic and high frequency electromagnetic properties of R₂Fe₁₇ compounds and their paraffin composites. It is found that the introduction of Si can remarkably improve the magnetic and electromagnetic properties of the R₂Fe₁₇ compounds, making the R₂Fe_17–xSi_x-paraffin composites excellent microwave absorption materials (MAMs). By introducing the Si element, their saturation magnetizations decrease slightly, while much higher Curie temperatures are obtained. Furthermore, better impedance match is reached due to the decrease of the high-frequency permittivity ε′ by about 40%–50%, which finally enhances the performance of the microwave absorption. The peak frequency (f_RL) of the reflection loss (RL) curve moves toward high frequency domain and the qualified bandwidth (QB, RL ≤ ?10 dB) increases remarkably. The maximum QB of 3.3 GHz (12.0–15.3 GHz) is obtained for the Sm_1.5Y_0.5Fe₁₅Si₂-paraffin composite (d = 1.0 mm) and the maximum RL of ?53.6 dB is achieved for Nd₂Fe₁₅Si₂-paraffin composite (d = 2.2 mm), both surpassing most of the reported MAMs. Additionally, a distinguished dielectric microwave absorption peak is observed, which further increases the QB in these composites.     

Cu基络合物催化甲醇液相氧化羰化反应

针对甲醇液相氧化羰基化法合成碳酸二甲酯(DMC)工艺,开发了新型Cu基络合催化剂(CuB rnLm)。对CuB rnLm催化剂的活性及其稳定性进行了研究。实验结果表明,采用该催化剂,甲醇转化率和DMC选择性较高;元素价态和物质结构分析表明,CuB rnLm催化剂循环使用5次后仍保持较好的稳定性。采用正交设计和中心响应曲面法设计实验,并使用S tatistica软件进行统计分析,寻求出反应的主要影响因素,并得到优化的工艺条件:反应温度100~110℃、反应压力3.0~3.5M Pa、反应时间4~6h、CuB rnLm催化剂质量浓度(以甲醇的体积计)0.15~0.20g/mL。在此工艺条件下,甲醇转化率可达23%以上,DMC的选择性为96%~98%。     

溶剂对环氧乙烷催化水合制乙二醇的影响

研究了NY催化剂催化环氧乙烷水合制乙二醇(EG)过程中,溶剂、催化剂添加量和水与环氧乙烷的摩尔比(简称水比)对EG选择性的影响。实验结果表明,以丙三醇作为溶剂使催化剂进行循环,能提高EG的选择性,效果好于以生成的EG作为溶剂循环催化剂。催化剂添加量、水比和溶剂添加量对EG选择性具有较大影响,其中溶剂添加量对EG选择性的影响最显著。在低水比(1.0~4.0)条件下,EG质量分数小于30%、催化剂质量分数大于7.2%时,EG选择性稳定在95.63%~97.92%,平均值为96.80%,此结果对于进一步降低EG合成工艺的能耗具有指导意义。     

光缆CATV用DFB激光器发射组件

介绍了国内首次研制的光缆ＣＡＴＶ用１．３μｍＤＦＢ激光器组件。组件工作频带达到１ＧＨｚ，带内起伏〈１ｄＢ，组件的ＲＩＮ〈－１５３ｄＢ／Ｈｚ；出纤光功率〉２ｍＷ，载噪比ＣＮＲ〉５０ｄＢ。首次实现用低反射尖锥端光纤的ＤＦＢ激光器耦合。     

住宅建筑结构中隔震技术的应用和经济评价

对当前隔震系统做了简单介绍 ,介绍了基础隔震的技术和施工方法等。讨论在住宅结构中推广隔震技术的方法 ,对各种类型的住宅结构做经济评价 ,讨论推广的可能性和难点。     

酒精中甲醇,水在NaA沸石上吸附性能的研究

本文测定了酒精中甲醇、水单组分及二元组分的吸附等温线,并用Langmuir方程进行了拟合。在固定床动态吸附研究申测定了酒精中甲醇、水单组分及双组分吸附穿透曲线;着重考察了流速、温度、不同甲醇和水含量对双组分吸附性能的影响。对二个组分的传质机理及置换关系进行了分析探讨。     

3mm波段极近距离雷达

提出一种极近距离雷达概念，并导出其作用距离公式，在此基础上研制出一台３ｍｍ波段极近距离多普勒雷达样机．试验结果表明该雷达结构简单，成本低廉，在作用距离为零点几米至几米范围内可获得较高的定距精度．     

集成基础结构中应用服务器的研究与开发

通过对集成基础结构中应用服务器的功能需求分析，采用面向对象方法、矩阵理论和Ｐｅｔｒｉ网技术研究了应用服务器系统的实现策略，并依据智能工程理论给出了应用服务器的系统结构。