金刚石薄膜制备和评价

采用平直钨丝作热解源,并借助钨丝支架的弹性恢复力,较好地解决了热丝热解化学气相沉积法(HFCVD)合成金刚石过程中热解丝的变形问题.样品独立加热,基片温度、钨丝温度、钨丝与样品基片距离均可独立调节.装置改进后,在Si(100)上合成了面积大约45mm×25mm的比较均匀的金刚石膜.用扫描电子显微镜(SEM)、Raman光谱和X射线衍射仪对制备的金刚石膜进行了分析.     

转变观念是润滑技术现代化的必要途径

探讨了国内润滑工作存在的问题，分析了近20年来润滑技术的发展状况，介绍了国内先进单位合理用油取得的效益和经验，提出用油现代化的看法。     

低相噪,低杂波数字锁相环路滤波器的设计

较详细地分析数字锁相频率合成器的相位噪声，着重用控制论方法对低相噪、低杂波锁相环的环路滤波器进行设计，并用某Ｓ波段频率合成器的实验结果进行了验证。     

对市毛纺二厂中南楼倒塌的分析研究

本市第二毛纺厂中南楼是一幢三层四跨的纯框架结构，它在1976年7月28日的唐山地震中，结构遭受了严重的破坏．后经过加固，在同年的11月15日的宁河地震作用下，房屋全部倒塌，笔者利用平面杆系模型，对其结构进行弹塑性分析，以期得到影响该房屋倒塌的因素。     

如何有效激励研发人员

研发人员要捣起鬼来,再精明的老板恐怕也拿他们没有办法.因为研发项目存在大量的不确定性,老板在管理研发人员时一般都是外行管理内行,研发人员可以随意地拿出几个技术问题甚至技术术语将老板弄得干着急."创新嘛,总有很多不确定性,因此我们无法制定准确的计划.譬如说,爱迪生能事先知道何时能够发明灯泡吗?牛顿能够预知他何时能够发现万有引力吗?……"我想,这些话说出来能将老板们噎得背过气去."技术问题"成了研发人员的免死牌.如果老板本身就是技术高手,这些问题可能少一些,但企业也可能面临更大的问题.     

基于"替换法"的汉字加、解密实现技术

文章讨论的基于“替换法”的汉字信息加、解密实现技术,改变了传统的汉字加密结果,使加密后的密文仍是可以识别和再利用的汉字,发送者可以在任何可编辑汉字的通讯设备上发送和接收密文,确保中文信息传输过程中的安全性。加、解密算法实现的代码语言为VFP6.0。     

机载隐蔽式短波天线研究

给出了一种用于Y7—200A运输机的隐蔽式短波天线，该天线为位于飞机垂尾前缘的回线天线，与飞机的外形共形，不影响飞机的飞行性能。在利用传输线理论与缝隙天线理论对该天线进行分析的基础上，对输入阻抗、天线与天线调谐器结合后的天线效率进行了研究，给出了该天线与KHF950电台相配合的测试试验结果，该天线能够在2．5MHz到30MHZ范围内与KHF950电台良好调谐，表明这种天线完全可以用于Y7—200A型飞机，代替原有的钢索天线。这是在国产飞机上首次使用这种天线。     

Microwave heating synthesis of HgS and PbS nanocrystals in ethanol solvent

A novel route was developed to prepare PbS and HgS nanocrystals in ethanol solvent in the presence of sodium hydroxide by microwave heating method. PbS and HgS nanocrystals were obtained with an average size of approximately 10 and 6 nm, respectively. In the reaction, mercury acetate and lead acetate were used as mercury and lead source; sulfur powder was employed as chalcogenide source. The products were characterized by X-ray powder analysis (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–Vis absorption spectroscopy. The probable mechanism was presented.     

Analytical solution for the axisymmetric plane strain electroelastic dynamics of a special non-homogeneous piezoelectric hollow cylinder

By virtue of the introduction of a dependent variable and the separation of variables technique, the axisymmetric plane strain electroelastic dynamic problem of a special non-homogeneous piezoelectric hollow cylinder is transformed to a Volterra integral equation of the second kind about a function with respect to time, which can be solved successfully by means of the interpolation method. Then the solutions of displacements, stresses, electric displacements and electric potential are obtained. The present method is suitable for a piezoelectric hollow cylinder with an arbitrary thickness subjected to arbitrary mechanical and electrical loads. Numerical results are finally presented.     

Generalized eigenvectors and fractionalization of offset DFTs and DCTs

The offset discrete Fourier transform (DFT) is a discrete transform with kernel exp[-j2/spl pi/(m-a)(n-b)/N]. It is more generalized and flexible than the original DFT and has very close relations with the discrete cosine transform (DCT) of type 4 (DCT-IV), DCT-VIII, discrete sine transform (DST)-IV, DST-VIII, and discrete Hartley transform (DHT)-IV. In this paper, we derive the eigenvectors/eigenvalues of the offset DFT, especially for the case where a+b is an integer. By convolution theorem, we can derive the close form eigenvector sets of the offset DFT when a+b is an integer. We also show the general form of the eigenvectors in this case. Then, we use the eigenvectors/eigenvalues of the offset DFT to derive the eigenvectors/eigenvalues of the DCT-IV, DCT-VIII, DST-IV, DST-VIII, and DHT-IV. After the eigenvectors/eigenvalues are derived, we can use the eigenvectors-decomposition method to derive the fractional operations of the offset DFT, DCT-IV, DCT-VIII, DST-IV, DST-VIII, and DHT-IV. These fractional operations are more flexible than the original ones and can be used for filter design, data compression, encryption, and watermarking, etc.