Anwendung radioaktiver Indikatoren zur quantitativen Bestimmung nichtmetallischer Einschlüsse in Stahl

Es werden Methoden zur Bestimmung und zur Untersuchung der Quellen von nichtmetallischen Einschlüssen im Stahl sowie einige Ergebnisse der radiometrischen Untersuchungen dargestellt.

Die Erfahrungen mehrjähriger eigener Forschungen in der Industrie und ein ausführliches Studium der Weltliteratur wurden zu einer Systematik und kritischen Diskussion der angewandten Methoden herangezogen. Es wurden optimale Verfahren zur quantitativen Bestimmung der Oxideinschlüsse sowie zur Feststellung ihrer Herkunft (z. B. aus der feuerfesten Ofenauskleidung, dem Stichloch, der Rinne, der Gießpfanne oder der Kokillenschlacke) ausgewählt.

Besprochen werden Probleme des Tracers (Art, Menge, Zustand, Aktivität), der jeder Einschlußquelle entsprechenden Markierungsmethode, der Probennahme, der chemischen Verarbeitung des Probenmaterials und des radiometrischen Meßverfahrens (einschließlich einer evtl. Aktivierung).

Abschließend wird eine Methode zur Bestimmung von bei der Desoxydation des Stahls entstehenden Einschlüssen kurz dargestellt.     

In situ study of magmatic processes: a new experimental approach

We present an internally heated autoclave, modified in order to permit in situ studies at pressure up to 0.5 GPa and temperature up to 1000 °C. It is equipped with transparent sapphire windows, allowing the observation of the whole experiment along the horizontal axis. In the experimental cell, the sample is held between two thick transparent plates of sapphire or diamond, placed in the furnace cylinder. The experimental volume is about 0.01 cm³. Video records are made during the whole experiment. This tool is developed mainly to study the magmatic processes, as the working pressures and temperatures are appropriate for subvolcanic magma reservoirs. However, other applications are possible, such as the study of subsolidus phase equilibria as we have used well-known phase transitions, such as the system of AgI, to calibrate the apparatus with respect to pressure and temperature. The principle of the apparatus is detailed. Applications are presented, such as studies of melt inclusions at pressure and temperature and an in situ study of magma degassing through the investigation of nucleation and growth processes of gas bubbles in a silicate melt during decompression.     

Scattering of a plane harmonic SH wave by multiple layered inclusions

Scattering of a plane harmonic SH wave by an arbitrary number of layered inclusions in a half-space is investigated by using a direct boundary integral equation method. The inclusions of arbitrary shape and placement are embedded within an elastic half-space. The effects of multiple scattering, the geometry, and the impedance contrast of the materials for layered inclusions and pipes are considered in detail.     

实$q$-一致光滑Banach空间中一类新的涉及广义 增生映射的集值变分包含组的近似可解性

A new system of set-valued variational inclusions involving generalized H(·, ·)-accretive mapping in real q-uniformly smooth Banach spaces is introduced, and then based on the generalized resolvent operator technique associated with H(·, ·)-accretivity, the existence and approximation solvability of solutions using an iterative algorithm is investigated.     

MULTIVALUED DIFFERENTIAL EQUATIONS IN BANACH SPACES AND THEIR APPLICATIONS

IIntroductionConsider the initial value problemDtL干Au＋1ugi．U＜t＜I,oh山)”w,where A is of of。s(S＋)and F is a multivalued msp．If F is singl。vlued Hiranoti goteistence results for Fbeing compact．Ahmed and Xiang[21 extended Hirano’s results forFsatls州ngthat＜Fu。,u。一U＞－＋ 0 lfunconverges wewyto h;While Liul3]e枕ended theabOV6 th6lltlollsd T6SllltS to COf正erpolldlllg ClAsS Of yatlatlollal ill6qttallt16s ld lfittodllC6d 8 hO16gmerdC0nd让ND th幼劝m比a bro劝0 d%sdpenurb砒…     

Breathing Effect via Solvent Inclusions on the Linker Rotational Dynamics of Functionalized MIL-53

The breathing effects of functionalized MIL-53-X (X=H, CH₃, NH₂, OH, and NO₂) induced by the inclusions of water, methanol, acetone, and N,N-dimethylformamide solvents were comprehensively investigated by solid-state NMR spectroscopy. 2D homo-nuclear correlation NMR provided direct experimental evidence for the host-guest interaction between the guest solvents and the MOF frameworks. The variations of the ¹H and ¹³C NMR chemical shifts in functionalized MIL-53 from the narrow pore phase transitions to large pore forms due to solvent inclusions were clearly identified. The influence of functionalized linkers and their host-guest interactions with the confined solvents on the rotational dynamics of the linkers was examined by separated-local-field MAS NMR experiments in conjunction with DFT theoretical calculations. It is found that the linker rotational dynamics of functionalized MIL-53 in narrow pore form is closely related to the computational rotational energy barrier. The BDC-NO₂ linker of activated MIL-53-NO₂ undergoes relatively faster rotation, whereas the BDC-NH₂ and BDC-OH linkers of activated MIL-53-NH₂ and MIL-53-OH exhibit relatively slower rotation. The host-guest interactions between confined solvents and MIL-53-NO₂, MIL-53-CH₃ would significantly induce an increase of the order parameters of unsubstituted carbon and reduce the rotational frequency of linkers. This study provides a spectroscopic approach for the investigation of linker rotation in functionalized MOFs at natural abundance with solvents inclusions.     

电化学方法研究X120管线钢氢致裂纹行为

采用Davanathan-Stachursky双电池渗氢装置研究了X120试验管线钢中电化学氢渗透动力学行为,运用电化学充氢方法对X120管线钢进行预制微裂纹,采用SEM观察钢中夹杂物及其与氢致裂纹（HIC）形成的关系。 实验结果表明,随着充氢电流密度的增大,饱和阳极电流I∞、氢扩散通量J∞、氢有效扩散系数Deff均逐渐增大;HIC萌生与钢中夹杂物化学成分有关,X120管线钢中主要含有Al、Mn的硫化物、氧化物夹杂,氮化钛、铌的复合夹杂以及Ca-Al-O-S的混合物夹杂,HIC更易于在含Al、Mn的夹杂物处萌生及形成,且裂纹形核后一般沿轧制方向生长。     

System of generalized variational inclusions with -accretive operators in uniformly smooth Banach spaces

In this paper, we consider and study a system of generalized variational inclusions with H-accretive operators in uniformly smooth Banach spaces. We prove the convergence of iterative algorithm for this system of generalized variational inclusions. A new definition of H-resolvent operator as a retraction is introduced, and in support of the definition, we have constructed an example and a numerical example through Matlab programming. Some special cases are also discussed.     

Reconstruction of inclusions in an elastic body

We consider the reconstruction of elastic inclusions embedded inside of a planar region, bounded or unbounded, with isotropic inhomogeneous elastic parameters by measuring displacements and tractions at the boundary. We probe the medium with complex geometrical optics solutions having polynomial-type phase functions. Using these solutions we develop an algorithm to reconstruct the exact shape of a large class of inclusions including star-shaped domains and we implement numerically this algorithm for some examples.     

On the Floquet problem for second-order Marchaud differential systems

Solutions in a given set of the Floquet boundary value problem are investigated for second-order Marchaud systems. The methods used involve a fixed point index technique developed by ourselves earlier with a bound sets approach. Since the related bounding (Liapunov-like) functions are strictly localized on the boundaries of parameter sets of candidate solutions, some trajectories are allowed to escape from these sets. The main existence and localization theorem is illustrated by two examples for periodic and anti-periodic problems.