硅酸铋晶体的蚀像形貌

本文研究了提拉法生长的硅酸铋晶体(BSO)的蚀像形貌,比较了{100},{110},{211},{111}面族的腐蚀像特征和腐蚀速度,并用周期性键链(PBC)的形貌理论分析了腐蚀形貌。通过蚀像形貌特征便可方便地进行晶体定向,准确地确定各族晶面之间的相对位置和极轴的方向等。     

An IR study on ion-specific and solvent-specific swelling of poly(N-vinyl-2-pyrrolidone) gel

Swelling degrees of poly(N-vinyl-2-pyrrolidone) (PVP) gel were measured in aqueous salt solutions and in water/organic solvent mixtures to find marked ion- and solvent-specificities. In order to investigate any correlation of those specificities with hydration or solvation of PVP, IR spectra band of the CO group was monitored by means of ATR method both for PVP gel and the relevant solution systems. Dependence of the peak frequency on the swelling ratio suggested that hydration of PVP carbonyl group in deswollen gel systems is different from that in the corresponding solution systems. In the solution systems, PVP carbonyl band showed a high-wavenumber shift for deswollen systems, which can be well correlated with changes in water proton charge through ionic hydration and with Gutmann's acceptor number of organic solvents. In the deswollen gel systems, the CO band showed a low-wavenumber shift, suggesting a strong hydration or doubly hydrated state. This unexpected behavior was interpreted by assuming an intermolecular hydrogen bond of two carbonyl groups intermediated by water molecules.     

一步法合成松香改性酚醛树脂

探讨了一步法合成松香改性酚醛树脂的反应机理，确定了最佳原料组成及合成工艺，由此制备出高溶解粘度和矿油容纳度的松香改性酚醛树脂，是一种性能优异的高级胶印油墨连接料     

双马来酰亚胺树脂体系的固化反应研究

利用ＤＳＣ及原位ＦＴＩＲ技术研究了双马来酰亚妥树脂体系的固化反应，获得了在固化反应过程中各组分的转化率与时间的关系，结合热分析数据，确立了最佳固化工艺。     

Synthetic resins: XV. Chelation ion exchange properties of 2,4- dinitrophenylhydrazone of resacetophenone-formaldehyde resin

A number of copolymers were synthesised by condensing the 2,4-dinitrophenylhydrazone of resacetophenone with substituted benzoic acids/ phenols and formaldehyde in the presence of sodium hydroxide or hydrochloric acid. The decomposition temperature, solubility and viscosity of the polymers have been determined. The ion-exchange properties have been studied by using a batch equilibrium method. The distribution of a number of metal ions between an aqueous solution and the resin have been measured. A wide range of pH and variable ionic strengths have been investigated.     

稀土树脂相分光光度法研究

在HCl—KCl(pH0.5)介质中,稀土—三溴偶氮胂二元络合物能较好地被阴离子交换树脂吸附。RE_2O_8在0～8μg/25ml范围内符合比尔定律,以双波长等吸收点法(测量波长λ_1=650nm,参比波长λ_2=740nm)扣除树脂背景影响,应用于稀土矿中稀土总量测定,结果令人满意。     

磨机大齿轮对缝处产生张口的初探

针对大中型磨机大齿轮对缝处在使用中会产生张口现象而降低其使用寿命的问题,从分析产生张口的原因入手,通过理论计算,提出设计的配合间隙,并指出在安装与使用中应注意的问题.     

Microstructure-related fracture toughness and fatigue crack growth behaviour in toughened, anhydride-cured epoxy resins

Fracture toughness and fatigue crack propagation (FCP) of plain and modified anhydride-cured epoxy resin (EP) were studied at ambient temperature. Liquid carboxyl-terminated acrylonitrile-butadiene (CTBN) and silicon (SI) rubber dispersions were used as tougheners for the EP. The morphology of the modified EP was characterized by dynamic mechanical analysis (DMA) and by scanning electron microscopy (SEM). The fracture toughness, K_c, of the compositions decreased with increasing deformation rate. K_c of the EP was slightly improved by CTBN addition and practically unaffected by incorporation of the SI dispersion when tests were performed at low cross-head speed, v. Both modifiers improved K_c at high v, and also the resistance to FCP, by shifting the curves to higher stress intensity factor ranges, ΔK, by comparison with the plain EP. It was established that both fracture and fatigue performance rely on the compliance, J_R, at the rubbery plateau, and thus on the apparent molecular mass between crosslinks, M_c. The failure mechanisms were less dependent upon the loading mode (fracture, fatigue), but differed basically for the various modifiers. Rubber-induced cavitation and shear yielding of the EP were dominant for CTBN, whereas crack bifurcation and branching controlled the cracking in SI-modified EP. The simultaneous use of both modifiers resulted in a synergistic effect for both the fracture toughness at high deformation rate and the FCP behavior.     

机械研磨 Ni_(50)B_(50)合金形成非晶的过程

本文研究了机械研磨 Ni_(50)B_(50)合金非晶的形成过程。唯象地提出用 J-M-A 方程描述此过程,并作了简单的讨论。     

大口径管道带水抢修

包头地区1996年5月3日发生6.4级强烈地震,给包钢生产造成重大损失,地震发生后,包钢生产用动力系统发生多起事故.本文针对4#高炉工业回水管道(φ1220×10)震后发生断裂,如何在保证不停止生产的前提下,采取什么措施进行管道带水抢修进行了阐述,本文是经过现场抢修过程总结而来,对今后大口径管道带水抢修提供了宝贵的经验.