电力负荷削峰减载系统在珠钢电炉的应用

借助现场采集装置,在计算机上获取每一分钟的冶炼工艺电能需求量,显示当前15分钟时段已发生的电耗量,调整用户设定,实现需量自动刷新、报警和专家分析推荐后续用量;实现平稳用电并减少对电网冲击,同时降低电能最大需用量以减少成本。     

Zur Nitratreaktion bei Milchprodukten

Zusammenfassung Wir haben die für die Abfüllung von Milchprodukten benützten Kartonpapiersorten auf ihren Nitratgehalt untersucht. Die untersuchten Kartonsorten zeigten schwankenden, aber unbedeutenden Nitratgehalt, der in erster Linie von den verschieden hohen Nitratgehalten der Fabrikationswässer abhängig ist. In den untersuchten Fällen wurde die Aufnahme von Nitraten durch Sauerrahm aus solchen paraffinierten Kartonbechern nachgewiesen. Die Herkunft dieser weit über den ursprünglichen Nitratgehalt der Kartons hinausgehenden Nitratmenge lag in dem zur Herstellung der Becher benützten, stark nitrathaltigen Stärkekleister. In solchen Fällen fallen somit die an die Nitratreaktion geknüpften Folgerungen (Wässerung, Verschmutzung) weg. Daher ist bei der Beurteilung der Milchprodukte auf Grund der Nitratreaktion auf diesen Umstand acht zu geben.Da solche Kartonbehälter auch zur Abfüllung anderer Lebensmittel verwendet werden (Honig, Senf, Marmelade usw.), behalten wir uns vor, unsere Untersuchungen auch auf dieses Gebiet auszudehnen.     

Buchbesprechungen

Ohne Zusammenfassung     

Agglomeration and networks in spatial economies

We consider the parallel developments in the economics of agglomeration and the economics of networks. We explore the complementarities between the productivity benefits of agglomeration and those of network linkages, arguing that networks of actors dispersed over space may substitute for agglomerations of actors at a single point.JEL Classification: D20, L14, R30     

Thomas Fincke und die <Emphasis Type="Italic">Geometria rotundi</Emphasis>

Thomas Fincke (January 6^th, 1561–April 24^th, 1656), born in Flensburg (Germany), was one of the very most important and significant scientists in Denmark during the seventeenth century, a mathematician and astrologer and physician in the beginning of modern science, a representative of humanism and an influentual academic organizer. He studied in Strasbourg (since 1577) and Padua (since 1583) and received his M.D. in Basel (1587), he practised as a physician throughout his life (since 1587 or 1590) and became a professor at Copenhagen (1591). But he was best known because of his Geometriae rotundi libri XIIII (1583), a famous book on plane and spherical trigonometry, based not on Euclid but on Petrus Ramus. In this influentual work, in which Fincke introduced the terms tangent and secant and probable first noticed the Law of Tangents and the so-called Newton-Oppel-Mauduit-Simpson-Mollweide-Gauss-formula, he showed himself to be „abreast of the mathematics of his time“.      

Bemerkungen zu “Himmelsbeobachtungen in karolingischer Zeit

Additional remarks are given for the data of auroras during the earlier centuries.     

Review on testers for measuring flow properties of bulk solids

 The author was asked by the International Fine Particle Research Institue (IFPRI) to write a critical review on shear testers for IFPRI-members. The review was delivered to IFPRI in summer 1999. Following the contract with IFPRI it was not allowed to publish the review elsewhere for at least two years. Granular Matter invited the author to submit the review in the original form; during the refereeing process (besides other changes) it turned out that some remarks should be added here for clarification: - Since 1999, the author is not aware of a really new device for testing bulk solid properties, which could lead to a change of the general comments and conclusions provided in the review. It was argued, that the review is referring too much to the work of Jenike, while the works of Johanson and Peschl were not adequately cited. Both are excellent engineers with a lot of experience, but their basic ideas are not available in published form, and if, they are not set in relation to alternative approaches so that an objective comparison in detail would be a future research issue rather than a topic in this report. A discussion on the influence of electrostatic charges was missing. There hardly is an influence, since the particles are in continuous contact. Only with non-conducting plastic particles electrostatic charges could cause problems. But no relevant experiments and results are known. In closed systems, the effect of electric charges is thus mainly neglected, but it is clear that electrostatic forces are eminent in flows with a free surface – an issue not addressed in this review. Received: 1 November 2002