The canonical solution operator of $ {\bar \partial } $ on weighted spaces with holomorphic coefficients

On weighted spaces with strictly plurisubharmonic weightfunctions the canonical solution operator of and the ‐Neumann operator are bounded. In this paper we find a class of strictly plurisubharmonic weightfunctions with certain growth conditions, so that they are Hilbert‐Schmidt operators between weighted spaces with different weightfunctions, if they are restricted to forms with holomorphic coefficients. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Carbide precipitates in solution-quenched PH13-8 Mo stainless steel: A small-angle neutron scattering investigation

This paper deals with the small-angle neutron scattering (SANS) investigation on solution-quenched PH13-8 Mo stainless steel. From the nature of the variation of the functionality of the profiles for varying specimen thickness and also from the transmission electron microscopy (TEM), it has been established that the small-angle scattering signal predominantly originates from the block-like metallic carbide precipitates in the specimen. The contribution due to double Bragg reflection is not significant in the present case. The single scattering profile has been extracted from the experimental profiles corresponding to different values of specimen thickness. In order to avoid complexity and non-uniqueness of the multi-parameter minimization for randomly oriented polydisperse block-like precipitate model, the data have been analyzed assuming randomly oriented polydisperse cylindrical particle model with a locked aspect ratio.     

Influence of oxidation time on semiconductive behaviour of thermally grown oxide films on AISI 304L

The oxide films formed on AISI 304L stainless steel at 300 °C in the oxidation time range between 2 and 4 h have been studied by photoelectrochemistry. Photocurrents were investigated as a function of the wavelength of the incident light and the electrode potential. The investigation allowed the determination of the semiconductive properties of the oxides. The oxide films showed n-type behaviour. A duplex structure of the oxide films has been suggested on the basis of the photocurrent spectra, with an internal oxide layer having an optical gap (E_g2 = 2.16-2.3 eV) depending on the applied potential and oxidation time, higher to that of the external oxide layer (E_g1 ≈ 1.9 eV). Significant variations in the amplitude of the photocurrent were detected as a function of the applied potential and the oxidation time.     

轻型汽车后桥半轴断裂件的组织及断口特征

采用光学显微镜和扫描电子显微镜等手段，对某轻型汽车40Cr后桥半轴断裂件的组织及断口特征进行了分析结果表明：半轴在调质处理时的淬火温度不够高，使其表层和心部组织中存在较多的铁素体相，造成了工件最终的硬度和疲劳强度不足，导致半轴在使用中发生扭转疲劳断裂．     

Rugged distal tips for CO2 laser medicine

Low-loss and rugged distal tips for CO₂ laser have been proposed and fabricated based on a commercially available stainless steel (St) pipe. A method of smoothening the inner surface of the St pipe with a rough inner surface is put forward. Fabrication parameters, transmission properties, and mechanical strength of the cyclic olefin polymer-coated silver hollow St distal tip are experimentally discussed.     

大型钢结构人行景观天桥的有限元分析

采用有限元方法对大型钢结构人行景观天桥进行了静力学、温度应力、动力学模态和初步的抗震能力分析,并就桥自重作用下的最大竖向位移和实际观测结果进行了比较,两者是一致的.计算结果表明:人行景观天桥在常规、温度极值改变和多遇地震荷载作用等多种工况下,现有的设计方案具有足够的强度、刚度和抗震能力.     

Cyclic cohomology and algebra extensions

We construct a spectral sequence to study cyclic cohomology for an extension A = R/I of algebras. When R is a free algebra we describe the cyclic cohomology of A in terms of traces defined on R or powers of I. Explicit cyclic cocycles representing the cyclic cohomology class belonging to the trace are constructed as analogues of Chern character and Chern-Simons forms.Dedicated to Alexander Grothendieck     

Effect of hydrogen on interatomic bonds in austenitic steels

Mössbauer spectroscopy was used to investigate the influence of dissolved hydrogen on the interatomic bonds in austenitic steels. It was carried out to prove the decohesion mechanism of hydrogen embrittlement (HE). It is shown that hydrogen increases Debye temperature, i.e., the interatomic bonds in hydrogenated austenitic steel becomes stronger.     

条形码技术的国际发展趋势及我国的对策

介绍了供应链管理中的一个得力工具——条形码技术，对这一技术进行了剖析，分析了条形码技术的国际发展趋势以及在我国的应用现状，最后针对我国在实现条形码技术时所遇到的各种问题提出了一些建议。     

Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution

The efficiency of 3,5-bis(n-pyridyl)-1,3,4-oxadiazole (n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO₄) have been determined by weight loss measurements and electrochemical studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO₄. The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR).