二溴对甲基偶氮甲磺光度法测定钢中微量锶

研究了二溴对甲基偶氮甲磺与锶生成2:1兰色络合物进行钢中微量锶的测定.该法λ_(max)=638nm,摩尔吸光系数E_(638)=5.01×10~4,锶量在0.02～0.34μg/L范围内服从比尔定律.方法已用于钢中微量锶的测定,结果满意.     

阳离子染料可染改性涤纶及涤纶织物的碱减量研究

以阳离子染料可染改性涤纶丝与普通涤纶丝混纺（或交织）织物为研究对象,探讨碱剂。促进剂、减量温度及时间等因素对减量率的影响以及不同减量工艺经阳离子染料染色对织物闪色效果的影响。研究表明在保证一定减量率的基础上,染色后织物具有一定的闪色效果。     

5种药用植物挥发油对仓库害虫生物活性的研究

研究了香薷、鹤虱等５种药用植物挥发油对仓虫的生物活性作用。结果表明,香薷挥发油的作用最为明显,它（剂量０２μＬ／ｇ）及其粗分离１＃～５＃样品（剂量００５μＬ／ｇ）均有效地抑制了试虫卵、幼虫及成虫的生长发育,从而减少了试虫Ｆ１代种群的发生,其中粗分离１＃样品作用尤为突出。香薷挥发油１＃～５＃样品的主要化学成分为４,５,６,７,８,８ａ－六氢－８ａ－甲基－２［１Ｈ］－奥酮（５２６４％）、百里香酚（３０５％）和一未定成分（２１９２％）。     

复合型导电高分子材料研究进展

简述了复合型导电高分子材料的研究及发展,并对其导电机理、基体树脂、导电填料的研究概况进行了述评,介绍了其在各领域中的应用．     

走向断层造成地层重复和缺失的简捷判断法

构造地质学对走向断层造成的地层重复,缺失一直沿用Ｃ．Ｍ．Ｎｅｖｉｎ的方法判断,此法比较繁琐。用以下法则可使其简捷：走向断层横剖面上如果上升盘地层扬起,则地表地层缺失;反之,如果上升盘地层倾伏,则地层重复。     

一次风反切系统的数值模拟和多相流动特性分析

四角切圆燃烧锅炉,存在着稳燃和结渣的矛盾,一次风微反切技术已在多台锅炉上得到应用,较好地解决了这对矛盾并能在一定程度上降低ＮＯｘ的排放量。本文把湍流理论和多相流动理论应用于炉内空气动力场的计算机数值模拟,用投影法编制的计算软件对６００ＭＷ锅炉炉内流动进行了计算,得出了一次风反切系统中炉内速度场、实际切圆、颗粒运动轨迹等结果,与冷炉和冷模试验基本吻合,对一次风反切系统的设计和调试具有参考价值。     

Chromium-doped forsterite: the influence of crystal characteristics on laser performance

A study of the dependence of the gain-switched laser operation of chromium forsterite on crystal parameters is presented. Results are reported for a wide range of chromium (IV) ion concentration: 0.02-0.12 at. % and 12-41 figure of merit, with emphasis on performance of the recently developed material with a dopant level of >0.10 at. %. Threshold and slope efficiency calculations are compared with measured performance for all crystals, with variation of pump polarization and output coupling. With 3% output coupling, the lowest threshold of 1.8 mJ, and highest slope efficiency of 13% were measured for a short, high-dopant-level crystal. With 33% output coupling a slope efficiency of 44% was measured for this crystal. Results demonstrate the considerable potential of short, high-dopant-level crystals for applications such as amplification, diode pumping, and narrow-bandwidth operation.     

NMR study of quaternary superconductor RM2B2C (R = Y,La, Th,and M = Ni,Pd, Pt)

¹⁹⁵Pt-,¹³⁹La- and¹¹B-NMR have been investigated in quaternary RM₂B₂C (R=Y, La, Th and M=Ni, Pd, Pt). The electric quadrupole frequency of¹³⁹La changes more than 5 times in magnitude from M=Ni to Pt, indicating that the hybridization of La-5d and d-electrons of M-element changes largely. The analysis of¹¹B and¹³⁹La spectra shows also the large change of the magnetic anisotropy with R and M element, i.e., _{II c}>_{II ab} in LaNi₂B₂C, but _{II c}>_{II ab} YNi₂B₂C.The data of T₁T and K of¹⁹⁵Pt and¹¹B are consistent with the band effects and with no evidence of strong antiferromagnetic correlation effects.     

High-performance aromatic polyimide fibres

A new polyimide has been synthesized from 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA) and 2,2-dimethyl-4,4-diaminobiphenyl (DMB). A high-strength, high-modulus, high-temperature fibre has been developed from this polyimide via a dry-jet wet spinning method. The tensile strength of BPDA-DMB fibres is 3.3 GPa and the tensile modulus is around 130 GPa. The compressive strength of the fibres has been investigated through a tensile recoil test (TRT), while the fibre morphology after compression has been studied via polarized light microscopy (PLM) and scanning electron microscopy (SEM). From the TRT measurements, we have observed that the compressive strength of this fibre is 665 (±5) MPa, which is higher than those of other aromatic polymer fibres. The effect of fibre diameter on the compressive strength of BPDA-DMB fibres is not substantial. The critical compressive strain for this fibre at which the kink bands start appearing under the observation of PLM is at 0.51–0.54%. Subglass relaxation processes have been observed and the measure of an apparent relaxation strength may serve as one of the factors which significantly affect the compressive strength of the fibres. Tensile tests of pre-compressed fibres reveal a continuous loss in tensile strength (up to 30%) with increasing the compressive strain (up to 2.6%). PLM and SEM observations show that during the compression BPDA-DMB fibres form regularly-spaced kink bands at ±60 ° (±2 °) with respect to the fibre axis. The kink band density initially increases with the compressive strain, and reaches a maximum at around 1.1%. Further increase of the compressive strain decreases this density due to the merge of the neighbouring bands. The size of kink bands also correspondingly increases within this compressive strain region. The morphological observation via SEM implies the existence of a skin-core structure and microfibrillar texture which are common features in polymer fibres.     

模拟电路故障诊断的约束聚类集成BP网络算法

针对通用BP网络对于高纬度、大数据量训练收敛困难的问题,在使用动量因子、自适应调整学习速率等方法的基础,引入约束聚类,构造集成神经网络,以提高网络的训练速度及诊断效果;首先,采用约束聚类算法将训练样本集划分为若干个规模相当的子样本集,分别训练生成相应子网络;此外,在诊断过程中除各子网络的输出变量外,还加入了诊断数据相对各子训练样本集的隶属度因子;最后通过一个实际电路板25维采样数据、38类故障的BP网络诊断实例验证了算法的可行性。