层次式级联多网络模型及其性能

本文提出了一种层次式级联多网络结构，论述了其训练算法，并验证了该结构的收敛性。这种结构在处理高阶非线性分布数据的分类问题方面具有优良的性能，用北京谱仪事例过滤进行性能测试结果表明，其训练和泛化性能都优于单个ＢＰ网络。     

游梁式抽油机曲柄销所受扭矩分析

在分析游梁式抽油机连杆大头轴承座因装配不当而产生变形的基础上，用有限元法分析了轴承所受的径向力，得出了曲柄销上所受的扭矩。最后，以ＣＹＪ１０－３－５３ＨＢ游梁式抽油机曲柄销为例进行计算，得出当轴承座径向变形量为０．１ｍｍ时，曲柄销中相应产生的扭矩可达１．０８ｋＮ·ｍ。为消除这种不良影响，应考虑采用其他的联接方式，以避免装配时产生过大的装配应力。     

电位滴定法研究~(99)Tc-HMDP和~(99)Tc-HEDP中Tc的氧化态

~(99)Tc-HMDP和~(99)Tc-HEDP溶液是在相应的螫合剂存在下,用过量SnCl_2还原~(99)TcO_4-制得。用标准I_2液对SnCl_2进行了剩余量电位滴定,确定了在pH～3的介质中,~(99)Tc-HMDP和~(99)Tc-HE-DP中~(99)Tc的氧化态均为+4。全部实验在N_2气流中进行。~(99)Tc-HMDP和~(99)Tc-HEDP的紫外光谱表明:在用I_2滴定的过程中,~(99)Tc只处于一种氧化态+4;将它们放置在空气中,一小时后仍较稳定。     

经食道心房调搏的放射性核素心血管造影

本文应用反符合电路剔除调搏脉冲干扰的方法,制成经食道心房调搏心电心音门电路触发装置,用于经食道心房调搏的核素心血管造影。参考Tzivoni标准,当逐级增加调搏心率至140次/min或亚极量心率后发现:冠心病人有调搏后EF降低;急性心肌梗塞病人EF减低更为明显,并呈室壁反向运动。因此,心房调搏核素心血管造影有助于冠心病,特别是心肌梗塞的诊断。     

焊接设备中计算机控制系统的抗干扰

本文分析提出焊接设备中影响计算机控制系统的几种主要干扰。结合实际工作,提出了解决的措施和方法。     

Site occupations and ordering behaviour of O phase in Ti2AlNb—based intermetallics

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｏｒｔｈｏｒｈｏｍｂｉｃａｌｌｏｙｓａｒｅｏｆｇｒｅａｔｔｅｃｈ ｎｏｌｏｇ ｉｃａｌｉｎｔｅｒｅｓｔｉｎｈｉｇｈｔｅｍｐｅｒａｔｕｒｅａｐｐｌｉｃａｔｉｏｎｓｓｉｎｃｅｔｈｅｙｈａｖｅａｇｏｏｄｂａｌａｎｃｅａｍｏｎｇｓｔ     

The Synthesis of Covalent Triazine-Based Frameworks via Friedel–Crafts Reactions of Cyanuric Chloride with Thienyl and Carbazolyl Derivatives for Fluorescence Sensing to Picric Acid,Iodine and Capturing Iodine

A multifunctional thiophene-based covalent triazine framework (TTPATTh) with triphenylamine as core is synthesized by Friedel–Crafts reaction of cyanuric chloride with thienyl derivative for the first time. The yield of TTPATTh (99.59%) is far higher than that of the carbazole-based CTF (TTPATCz, 47.03%). TTPATTh and TTPATCz possess high BET surface areas with 1235 and 2501 m² g^–1 as well as high pore volumes with 1.60 and 2.23 cm³ g^–1, respectively. TTPATTh and TTPATCz have high thermal stability with high thermal decomposition temperatures of 514 and 598 °C in nitrogen atmosphere. With the introduction of triazine rings, the fluorescence sensing sensitivities of TTPATTh and TTPATCz to picric acid and iodine are improved significantly. Especially for TTPATTh, the K_sv values reach 5.95 × 10⁵ and 1.61 × 10⁴ L mol^–1, and LODs reach 1.02 × 10^–12 and 1.86 × 10^–12 mol L^–1. To the best of the knowledge, this is the most sensitive value among thiophene-based porous organic polymers to PA and I₂. Furthermore, TTPATTh and TTPATCz can also adsorb iodine in vapor phase, cyclohexane solution and aqueous solution, and release iodine by heating or in ethanol solution. The efficiency of controlling the release of iodine is higher than that in ethanol.     

活性酯硬化水玻璃砂的研究

用焙烧活性砂混制而成的活性酯硬化水玻璃砂与普通酯硬化水玻璃砂相比，强度成倍提高，从而减少水玻璃的加入量，改善水玻璃砂的溃散性。实验证明：原砂的表面活性直接影响在水玻璃砂中水玻璃的加入量，是改善水玻璃砂溃散性的关键之一。焙烧活性砂的水玻璃加入量只要１．５％～２．０％，即能满足实际生产的强度要求。     

航空发动机滑油系统镁合金微生物腐蚀与防护

针对航空发动机滑油系统镁合金部件的工作环境特点，结合外场出现的滑油系统故障分析和返厂大修某发动机统计资料，发现微生物是引起其腐蚀的主要原因。同时，提出一些防护措施。     

Electron Emission from Barium Strontium Titanate Ceramics

This paper focuses on understanding the influence of materials' properties on the ferroelectric electron emission. Ferroelectric ( x =1.0 and 0.8) and paraelectric ( x =0.67 and 0.5) compositions of barium strontium titanate (Ba _x Sr_{(1− x )}TiO₃) system were chosen for study based on their different ferroelectric and dielectric properties. Similar emission current waveforms were obtained from four compositions with negative triggering voltage applied to the rear electrode of the samples. It was difficult to explain the experimental results using the spontaneous polarization-switching model. The mechanism of electron emission from Ba _x Sr_{(1− x )}TiO₃ ceramics was ascertained to surface plasma emission.