激光束偏转法检测金属表面层的缺陷

本文编程计算了由激光光热应产业的金属表面的温度分布和泵浦光的调制频率、金属层厚度等的关系，预言检测浓度缺陷的能力。用激光光束偏转法检测到表面下不同深处的缺陷，并把面扫描幅值信号以三维象和灰度象显示。     

Effects of capsules on attachment of human periodontal ligament fibroblasts to root surface

The stability of cimetidine (Tagamet) was investigated in total parenteral nutrition (TPN) mixtures containing different amino acid sources. TPN mixtures were stored at 5 degrees C in ethylvinyl acetate bags for 28 days and analysed by stability-indicating high-pressure liquid chromatography. Results indicated that cimetidine was physically compatible and chemically stable (less than 5% degradation) for at least 28 days in TPN mixtures containing either Freamine III, Vamin 14 or Aminoplex 12 as the amino acid source.     

相干光纤通信系统中的偏振分集接收机的实验研究

本文讨论了相干光纤通信系统中的偏振分集接收机的基本原理,并在实验中首次实现了基于偏振分集的偏振不敏感接收。在调制信号为137.2MHz和146.0MHz正弦波的情况下,得到了很好的与信号偏振面无关的解调信号。这一结果正在应用于1.5μm波段140Mb/s FSK相干光纤通信系统之中。     

准分子激光泵浦的皮秒染料激光器

利用准分子激光泵浦猝灭式染料激光器，获得了３０ｐｓ的可调谐染料激光脉冲输出。     

一种抑制SDH网中指针调整抖动的平滑相位泄漏技术

指针调整会在ＳＤＨ网中引入非常大的低频抖动。通常，在解同步器中需要采用指针泄漏技术来抑制这种抖动以使设备满足ＩＴＵ－Ｔ建议Ｇ．７８３的要求。本文给出了一种新颖的抑制指针调整抖动的方法，这种方法通过一个数字锁相环对指针抖动进行平滑并将平滑相位调相到一个参考信号上，从而避免了１比特或１／Ｎ比特泄中存在的较大的相位量化阶跃。这种方法对指针抖动的泄漏可以近似为一个平滑的过程。对一个ＡＵ－４／Ｅ４实验系统的     

A simplified CAD of millimeter-wave diplexer with E-plane T-junction and all-metal insert filters

An equivalent circuit theory design of a class of rectangular waveguide E-plane T-junction diplexer with E-plane all-metal insert filters is presented. Element values of equivalent circuit models of E-plane T-junction proposed in [1] are computed and approximated. The parameters of the filters designed by [2] are also given. By use of the network combining technique, the scattering matrix of the diplexer is obtained and optimized according to the diplexer specification with a novel objective function. The experimental results show a fairly good agreement with the computed results.     

筛前神经及下鼻甲激光切割术治疗过敏性鼻炎29例临床观察

本文介绍了用筛前神经和下鼻甲激光切割术治疗２９例过敏性鼻炎病人，有效率为９７％。随访６个月至２年，除２例于术后６个月复发外，余者均未复发。实践表明这一手术优于翼管神经手术，优点是：１、解剖标志清楚；２、手术操作简便且易于掌握；３、并发症少而不严重。本文对这一手术的方法，术后处置和疗效进行了讨论。     

Ginkgolides antagonizing some effects of platelet-activating factor in vitro

The mixture of platelet-activating factor (PAF) and platelets produced significant contraction of guinea pigs' bronchus, while the contraction induced by PAF alone was mild relatively, the IC50 were 6.14 x 10(-7) mol/L and 6.32 x 10(-4) mol/L respectively. There was significant difference between these two groups (P < 0.05). When the platelets were pre-incubated with ginkgolides for 10 minutes in Tris-Tyrode's buffered saline, effects of the PAF and platelets mixture were significantly inhibited (P < 0.01). Exposure of guinea pigs' bronchus to PAF in vitro resulted in a loss of beta-adrenergic receptors and responses to isoproterenol, and this effect of PAF was prevented by prior incubation of the guinea pigs' bronchus with ginkgolides (P < 0.05). The results showed ginkgolides were a potent PAF antagonist.     

DNS／GPS组合导航系统研究

本文阐述ＤＮＳ与ＧＰＳ组合导航的必要性、可行性及组合方法，给出了误差模型和卡尔曼滤波模型。选取观测量不同可有三种组合方式，通过模拟计算给出了相应曲线。当采用伪距及其变化率作为观测量时，其组合方式最佳，定位精度可达米级，航向精度可提高到０．２°。     

Comparative studies of several methods to determine the dynamic fracture toughness of a nuclear pressure vessel steel A508 CL3 with Charpy-size specimen

In this investigation, five estimation methods have been adopted to estimate the dynamic fracture toughness of a nuclear pressure vessel steel A508 CL3 by using pre-cracked Charpy-size specimens on an instrumented impact test machine. Furthermore, the merits and the demerits of the five methods have also been compared. The experimental results indicate that the maximum load energy method based on the curve of load versus load-point displacement overestimates the dynamic fracture toughness J _Id , especially above room temperature. The method of compliance changing rate underestimates the dynamic fracture toughness. The method of measuring the critical stretch zone width (SZW _c ) at the crack tip by means of SEM fractography and then converting the SZW _c into J _Id has a relatively large error. In addition, it is expensive and difficult to measure the SZW _c . The method of energy revised at the maximum load may be considered a better single-specimen method for determining the dynamic fracture toughness. Furthermore, the results indicate that although the dynamic resistance curve method can exactly estimate the dynamic fracture toughness of the material, this method needs several specimens. Moreover, the test procedure is complicated. Thus, it is not suitable for nuclear reactor pressure vessel embrittlement surveillance.