The Tautomerism between Ketene Aminals and Amidines

A tautomerie equilibrium between ketene aminals and amidines is disclosed as an electron-donating group is substituted at the para-position of the phenyl ring in 4 .     

电除尘器电场闪络原因分析及改进

针对浑江发电公司5号静电除尘器电场内部频繁闪络现象,分析了电场电压、电流较低且运行不稳定,除尘效率降低的问题,提出了除尘器在设计、安装等方面存在的不足。经过改造,除尘效率提高到99.55%。     

共轭多孔聚合物应用于近红外光热转换材料

近红外光热转换材料在光热治疗、光驱动智能器件等医学和能源领域受到广泛重视.本文以商业化芳香小分子为单体,通过一步简单的交联聚合方法制得了四种共轭多孔聚合物,并首次系统研究了它们的光热转换性能.结果表明,它们均具有灵敏的近红外光热响应性,且材料的光热转换效率与单体结构中共轭苯环数有很大关系,其中两种聚合物的光热转换效率可...     

从通信专家到信息专家的机遇与挑战

本文从未来移动通信技术发展展望,当前工作中的热点问题及提高中国移动软实力3个方面进行了阐述。     

研究型20kW燃料电池发动机的设计及试验

为研究开发高性能燃料电池发动机,设计了一台研究型20 kW燃料电池发动机。在此发动机上研究了空气系统压力、流量、温度参数对燃料电池性能的影响,同时测试了氢气侧压力降。发现在一定氢气过量系数下燃料电池堆氢气侧压力降与输出电流成线性关系,对于间接判定燃料电池堆内液态水过多提供了依据。     

基于神经网络的机械结构系统优化问题的分解算法

基于前馈神经网络的权重分析，针对优化问题提出了一种分解算法，探讨了神经网络在桁架结构系统优化中的应用。实例分析表明此方法是可行和有效的。     

产品模型定位系统核心技术研究

模型定位一直是逆向工程领域和图像处理领域的重要技术之一,结合零件加工定位和无损检测的需要,提出了产品模型定位系统框架和问题解决方法。该系统以工业CT或CMM测量数据作为三维输入方式,构成待配准模型,以CAD模型作为理论模型。针对待配准模型与理论模型,研究并实现了粗配准技术、精确配准技术、配准定位的分析评估以及数据拼合等核心技术。该系统可以应用于无损检测、无损评估以及加工定位等领域,具有广泛的应用前景。     

Unfolding core asymmetries with x-ray emission images in symmetry diagnostic experiments

A novel inversion technique is proposed to unfold core asymmetries at the source with x-ray emission images, which were obtained from imploded surrogate capsules in symmetry diagnostic experiments. The axisymmetrical core emission can be expanded as a Fourier series, with Legendre polynomials and spherical Bessel functions as bases concerned with polar angle and radius, respectively. A least-squares estimator is employed to obtain the unknown coefficients from its two-dimensional image data. The unfolded Legendre coefficients can be further used to test modeling of drive asymmetries in hohlraums. This technique is also demonstrated with a proof-of-principle experiment performed on the Shenguang II laser facility [L. Zunqi et al., Chin. J. Lasers B10, 6 (2001)].     

PCVD TiN膜的界面制备及性能

用ＴｉＣｌ４作为反应气体制备ＰＣＶＤ ＴｉＮ镀层,对降低界面的氯含量,改善ＰＣＶＤＴｉＮ镀层的界面性能进行了研究。在镀层制备过程中增加了界面制备过程,即采用氩离子轰击以及氢的反应使界面的氯含量降低,膜基界面得到改善。结果表明,与常规ＰＣＶＤ制备的ＴｉＮ镀层相比,膜层的结合强度有大幅度的提高,耐磨性和耐蚀性均有改善,特别是其耐蚀性达到甚至超过奥氏体不锈钢的水平。     

Synthesis and Characterization of In Situ(Al_2O_3–Si)/Al Composites by Reaction Hot Pressing

In situ(Al2O3–Si)/Al composites with a reinforcement volume fraction of 10% were synthesized from the Al–Si O2 system using low energy ball milling and reaction hot pressing. Differential thermal analysis was used to investigate the reaction mechanisms between Si O2 and Al. X-ray diffraction results revealed that the reaction between Al and Si O2 took place completely at 900 °C with a holding time of 2 h, thereby forming Al2O3 and Si. Scanning electron microscopic, energy dispersive X-ray spectroscopic, and transmission electron microscopic(TEM) results showed that the in situ synthesized Al2O3 and Si particles, whose sizes are less than 2 lm, were polygonal in shape and dispersed uniformly in the matrix. Moreover, Al2O3 particle size showed a tendency to increase from *2 to *6 lm when the synthesis temperature was increased. Furthermore, TEM observation showed that the interface between the reinforcements and Al matrix is clean. The yield strength, ultimate tensile strength, and Brinell hardness of the in situ(Al2O3–Si)/Al composite was significantly higher than the aluminum matrix. Mechanisms governing the tensile fracture process are discussed.