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Investigations on the Corrosion Behaviour and Structural Characteristics of Low Temperature Nitrided and Carburised Austenitic Stainless Steel

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材料热处理学报 2004年第5期25卷 311-315页

作者： D. Mnter H.-J. Spies H. Biermann chr. Eckstein Department of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyDepartment of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyDepartment of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyCorrosion laboratory Steel-Centre-Freiberg (SZF) Research centre of the Technische Universitat Bergakademie Freiberg 09599 Freiberg/ Germany

The wear resistance of austenitic stainless steels can be improved by thermo-chemical surface treatment with nitrogen and carbon. However, it is possible that the corrosion resistance will be impaired by the precipitation of chr.miumnitrid or -carbide. The present contribution deals with investigations of the corrosion behaviour and structural characteristics of a low temperature nitrided and carburised austenitic stainless steel. The material investigated was AISI 316L (X2CrNiMol7-12-2) austenitic stainless steel. A commercial plasma-nitriding unit (pulsed dc) was used for the nitriding and carburising process. Additional samples were treated by the gasoxinitriding process for a comparison between plasma- and gasoxinitriding. The nitrided and carburised layer of austenitic stainless steel consists of the nitrogen or carbon S-phase (expanded austenite), respectively. X-ray diffraction investigations show the typical shift of the peaks to lower angles, indicating expansion of the fee lattice. Also the X-ray diffraction technique was employed to study the residual stresses in the nitrogen and carbon S-phase. The corrosion behaviour of surface engineered samples was investigated with electrochemical methods. Anodic potentiodynamic polarisation curves were recorded for testing the resistance against general corrosion (in H2SO4) and pitting corrosion (in NaCl).

关键词：奥氏体不锈钢腐蚀低温渗氮低温渗碳残留应力

航行时轴带发电机同柴油机并联运行的频率波动分析

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机电设备 1985年第8期 30-38页

作者： chr.弗里克 K.吕塞尔宋新新

1.导言联邦德国汉诺威大学船舶辅机研究所对现代冷藏集装箱运输船上的大型轴带发电机装置和电网进行了广泛的测试分析。本文将对轴带发电机和柴油发电机并联运行的可行性进行分析及阐述。

关键词：并联运行辅柴油机船舶电网模拟计算轴带发电机转子角

Very Original Proofs of Two Famous Problems: “Are There Any Odd Perfect Numbers?” (Unsolved until to Date) and “Fermat’s Last Theorem: A New Proof of Theorem (Less than One and a Half Pages) and Its Generalization”

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Advances in Pure Mathematics 2021年第11期11卷 891-928页

作者： Demetrius chr. Poulkas Department of Mathematics Aristotle University of Thessaloniki Thessaloniki Greece School of Electrical and Computer Engineering National Technical University of Athens Athens Greece School of the Faculty of Engineering Aristotle University of Thessaloniki Thessaloniki Greece Department of Mechanical Engineering and Aeronautics Faculty of Engineering University of Patras Patra Greece

This article presents very original and relatively brief or very brief proofs about of two famous problems: 1) Are there any odd perfect numbers? and 2) “Fermat’s last theorem: A new proof of theorem and its generalization”. They are achieved with elementary mathematics. This is why these proofs can be easily understood by any mathematician or anyone who knows basic mathematics. Note that, in both problems, proof by contradiction was used as a method of proof. The first of the two problems to date has not been resolved. Its proof is completely original and was not based on the work of other researchers. On the contrary, it was based on a simple observation that all natural divisors of a positive integer appear in pairs. The aim of the first work is to solve one of the unsolved, for many years, problems of the mathematics which belong to the field of number theory. I believe that if the present proof is recognized by the mathematical community, it may signal a different way of solving unsolved problems. For the second problem, it is very important the fact that it is generalized to an arbitrarily large number of variables. This generalization is essentially a new theorem in the field of the number theory. To the classical problem, two solutions are given, which are presented in the chr.nological order in which they were achieved. Note that the second solution is very short and does not exceed one and a half pages. This leads me to believe that Fermat, as a great mathematician was not lying and that he had probably solved the problem, as he stated in his historic its letter, with a correspondingly brief solution. To win the bet on the question of whether Fermat was telling truth or lying, go immediately to the end of this article before the General Conclusions.

关键词： Perfect Numbers Odd Perfect Numbers Fermat’s Last Theorem Generalization of the Fermat’s Last Theorem Prime Number Problems Millennium Problems

Extended Cognition as a Case of Bottomless Theory Building

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Journal of Philosophy Study 2013年第12期3卷 1071-1087页

作者： Gerhard chr. Bukow University of Magdeburg

Extended cognition is the thesis that vehicles realizing cognitive systems can possibly extend beyond traditional boundaries of brain, skin, or skull. It is a popular thesis because of its counterintuitive consequence that coupled systems of vehicles of very different entities could form a realizer of one cognitive systems. Popular examples consist of human-handy-systems or human-notebook-systems, and it is a thesis that could non-dogmatically decide what individuates the realizers of cognitive systems. But the thesis is in need for individuation-criteria： How could we individuate a coupled system of different systems of vehicles？ We inspect some of the usually handled candidates for individuation-criteria and argue that in principal there will be no successful candidate due to methodological problems. We aim to show this by using a cookbook theory of extended cognition and add different types of candidates. No candidate is non-arbitrary or non-intrinsic, which leads the proponent to the forced selection between arbitrary or intrinsic candidates. We argue that without criteria, the talk about extended cognition is a bottomless pit that should only serve as an example for bottomless theory-building.

关键词： extended cognition cognitive system coupled system individuation-criteria

How Should We Construct Mind-Readers？

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Journal of Philosophy Study 2013年第9期3卷 801-822页

作者： Gerhard chr. Bukow M.A. Institute of Philosophy University of Magdeburg Germany

Structured models of kinds of mind-readers are explanatory tools in philosophy and psychology. Structure means that a structure like a theory with certain properties organizes the model of a kind of a reader. Structured models serve to explain mind-reading capabilities in opposition to pure behavior-reading capabilities by explicating properties of the structure that bring on specific capabilities of mind-reading. Typically, grades of fulfilling reading-capabilities are related to grades of rationality. But it is unclear：（1） when we are legitimated to title a reader a mind-reader or behavior-reader, and （2） how the kinds of readers are related with each other （if they can be related by a measure）. I argue that we know a reader if we can construct it and this gives legitimation. But it is unclear how to construct border-cases of readers, for example, minimal mind-readers. Should minimal mind-readers be constructed on the base of ＂reduced＂ mind-readers, or should they be constructed as ＂enriched＂ behavior-readers？ This is the specific question concerning the relations between readers the essay deals with by trying to reduce a maximal mind-reader by Craig-reduction. Because this kind of reduction-method fails, constructing specific kinds of mind-readers needs further research.

关键词： rationality mind-reader construction mind-reading

Evaluation of La AlO_3 as top coat material for thermal barrier coatings

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Transactions of Nonferrous Metals Society of China 2018年第8期28卷 1582-1592页

作者： N.VOURDAS E.MARATHONITI P.K.PANDIS chr.ARGIRUSIS G.SOURKOUNI C.LEGROS S.MIRZA V.N.STATHOPOULOS Laboratory of Chemistry and Materials Technology School of technological ApplicationsTechnological Educational Institute of Sterea Ellada 34400 Psachna Campus Evia Greece School of Chemical Engineering national Technical University of Athens I. Polytectmeiou 9 15780 Zografou Athens Greece Inst. f. Metallurgie Technische Universitat Clausthal Robert-Koch-Str. 42 38678 Clausthal-Zellerfeld Germany Institut de Chimie Moleculaire et des Materiaux d'Orsay université Paris Sud Bt 410 91405 Orsay Cedex France ELEMENT S.A. Hitchin SG4 0TW UK

Perovskite is a versatile group of oxide materials allowing their properties to be tailored by composition towards specific requirements. La Al O3 was prepared to study and report its properties in the context of its potential in thermal barrier coatings（TBCs） technology. A citric acid method was used for synthesis and the perovskite structure was confirmed using XRD and FT-IR. Viscosity of the solution precursor was checked as well as the particle size by laser particle size analysis. Densification behavior of the material was followed by conventional sintering and by spark plasma sintering. Apparent porosity by the Archimedes method, thermal conductivity and thermal expansion coefficient were studied. Mechanical and fracture properties were measured at elevated temperatures up to 1300 ℃ For samples sintered at 1200-1400 ℃, coefficient of thermal expansion ranged from 5.5×10^-6 to 6.5×10^-6 K^-1 and thermal conductivity ranged between 2.2 and 3.4 W/（m？K）. Elastic modulus and ultimate stress were measured at 1000-1300 ℃, while by micro-indentation, fracture toughness was found to be 3 MPa·m1/2. As the sintering temperature increased from 1200 to 1500 ℃, significant densification from 3.21 to 5.81 g/cm^3 was found, indicating that material annealing should be made at least at 1400 ℃. Under this condition, negligible dimensional change in phase transition temperature of La Al O3 from the rhombohedral（R3 c） to the ideal cubic（Pm3 m） is found. Data reported in this work can be useful for comparing the mechanical and fracture behaviours of different TBCs developed involving La Al O3 as well as input for numerical simulations.

关键词： perovsldte lanthanum aluminate thermal barrier coating (TBC)

A Brief New Proof to Fermat’s Last Theorem and Its Generalization

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Journal of Applied Mathematics and Physics 2020年第4期8卷 684-697页

作者： Demetrius chr. Poulkas Department of Mathematics of Aristotle University of Thessaloniki Thessaloniki Greece School of the Faculty of Engineering of Aristotle University of Thessaloniki Thessaloniki Greece School of Electrical and Computer Engineering of National Technical University of Athens Athens Greece Department of Mechanical Engineering and Aeronautics of Faculty of Engineering of University of Patras Patra Greece

This article presents a brief and new solution to the problem known as the “Fermat’s Last Theorem”. It is achieved without the use of abstract algebra elements or elements from other fields of modern mathematics of the twentieth century. For this reason it can be easily understood by any mathematician or by anyone who knows basic mathematics. The important thing is that the above “theorem” is generalized. Thus, this generalization is essentially a new theorem in the field of number theory.

关键词： Brief Proof of Fermat’s Last Theorem Unsolved Mathematical Problems Fermat’s Last Theorem Generalization of the Fermat’s Last Theorem Prime Number Problems Millennium Problems

Asphalt　fractions　in　airborne　particles　from　highway　traffic　and　the　accumulation　in　plants

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Journal of Environmental Sciences 1996年第2期8卷 196-202页

作者： He Kebin(Department of Environmental Engineering, Tsinghua University, Beijing 100084,China)Hans Mosbaek Jens chr. Tjell(Department of Environmental Engineering,Technical University of Dentnark, 2800 Lyngby,Denmark) Dept. of Environmental Engineering Tsinghua University Beijing 100084 China Dept. of Environmental Engineering Technical University of Denmark 2800 Lyngby Denmark

With reference to ASTM D4124, asphalt fractions, including polar aromatics (polars),naphthene aromatics (aromatics) and saturates,were characterized both in airborne particles collected in the distances of 2.0 -83.6m from the highway and in the plant samples (including grass,leaves and wheat straw) collected in the distance of 2.0 -10. 0m from the highway. In comparison to the results of diesel particulate, background plant samples and asphalt cernent samples from highway surface, it is concluded that there could be asphalt rnatters in airborne particles and asphalt makes the rnain contributions to the accumulation of the three factions mentioned above in plant species. In the ambient air,the concentrations of the three asphalt fractions are 0. 54- 3.06 ×10-3 mg polars,1. 77- 9. 50 × 10-4 mg aromatics and 0. 21- 1. 23 × 10-4 mg saturates for per cubic meter air. The percentage of bitumen in airborne particles is 1. 61%-11. 02%. In the plant samples, the concentrations are 0. 29- 3.07mg polars, 0.89- 3.89 aromatics and 0. 37-1. 53 mg saturates for per gram dry plant materials.

关键词： asphalt airborne particle traffic pollution HPLC.

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铝中杂质的取样与分析

轻合金加工技术 1989年第3期17卷 15-18页

作者： chr.J.SIMENSEN 杨小永

一、前言铝制品的许多性能与其中的杂质密切相关.典型的例子是,金属印刷铝板(PS板——译者注)的质量由于存在大夹杂物而降低,许多铝合金的塑性受富铁金属间相的大小及其分布的极大影响.现在,铝工业通过对熔体进行净化,对杂质进行分析,... 详细信息

一、前言铝制品的许多性能与其中的杂质密切相关.典型的例子是,金属印刷铝板(PS板——译者注)的质量由于存在大夹杂物而降低,许多铝合金的塑性受富铁金属间相的大小及其分布的极大影响.现在,铝工业通过对熔体进行净化,对杂质进行分析,可在很大程度上对其产品质量进行控制.关于杂质的取样与分析主要有两个问题:一是夹杂物在熔体中的分布通常不均匀。

关键词：铝杂质夹杂物取样金相分析