Kondensationsprodukte von Oxyketonen und Aminoketonen mit 2,4,5-Triamino-6-oxy-pyrimidin

Summary By condensing 2:4:5-triamino-6-hydroxy-pyrimidine with dihydroxyacetone (diacetate), diaminoacetone or acetone-1,3-di (p-formylaminobenzoic acid) not the expected 8- or 9-oxymethyl resp. -aminomethyl-pteridines but 8-or 9-methyl-pteridines were obtained. With p-tolyl-d-isoglucosamine not a tetrahydroxybutyl-pteridine but a trihydroxybutyl-pteridine was formed. For an explanation of these results it is supposed that from the dihydro-pteridines formed at first by intramolecular splitting off of H₂O or R·NH₂ aromatization takes place.     

A propos d'antibiotiques insolubles

Summary The authors show the antibiotic activity of water-insoluble salts of hydrosoluble antibiotics in the case of penicillin G (salts of iron, copper, silver, gold, and uranium) and streptomycin (oleate).     

证券投资组合理论和无差异曲线

文章通过无差异曲线解释了最优证券投资组合并探讨了对现代投资组合理论三个主要组成部分的有关内容.     

浅析基于电子商务网络安全PKI技术的角色访问控制模型

文本提出了一种区别于传统自主访问控制策略和强制访问控制策略的RBAC网络安全策略,并提出了RBAC的面向对象模型,实现用户身份认证与访问权限的逻辑分离,且易于控制,既能有效的改进系统安全性能,又极大地减少了权限管理的负担。     

Long term monitoring of urban subsidence by Permanent Scatterer DInSAR

When using differential SAR interferometry (DInSAR) to monitor the surface deformation over a long time scale, it is often strongly affected by the spatial and temporal decorrelations and atmospheric dishomogeneities. The recently developed Permanent Scatterers (PS) technique proposed by Fertti et al. can overcome these difficulties by interpreting time-series of interferometric phase only at coherent point scatterers. In this study, we apply this PS technique using 25 ERS-1/2 scenes from 1992 to 2000 to monitor the subsidence in Suzhou. By using the linear deformation model, the deformation map in Suzhou urban area over the eight years is obtained. And the calculated results are in good agreement with the measurements of leveling.     

Influence of Microstructure and Sintering Routes on Transport Properties of Apatite Materials for Fuel Cells

1 Results Oxy-apatite materials are thought as zirconia-substitutes in Solid Oxide Fuel Cells due to their fast ionic conduction. However, the well known difficulties related to their densification prevent them from being used as such. This study presents strategies to obtain oxy-apatite dense materials and the influence of elaboration route on transport properties. Particular emphasis is put on the microstructure effect on ion conduction. By the combined use of freeze-drying and conventional or spark p...     

高校青年教师的专业化发展策略

高校青年教师专业化应立足于自主发展,加强自身五个方面的修养,还要立足于提高和增强批判意识与创新能力、学习与研究能力、教育审美能力,从选用机制、竞争机制、利益机制和学术创新等方面建立起适合青年教师健康成长的环境,使青年教师专业化更好地发展.     

Experimental gout from alloxan in pigeons. Findings in the joints and serous membranes

Zusammenfassung Bei Tauben erzeugt intravenös gegebenes Alloxan bekanntlich Läsionen, die denen der Eingeweidegicht ähneln. Chemische und mikroskopische Untersuchungen zeigten eine große Menge von Uraten auf Perikardium, Peritoneum und Pleura. Die große Zunahme der Harnsäure im Blute, die von anderen Autoren kolorimetrisch festgestellt wurde, wird durch die Urikasemethode bestätigt. In der vorliegenden Mitteilung wird weiterhin über ein der Gelenkgicht ähnliches Bild bei alloxanbehandelten Tauben berichtet. Verschiedene Tierarten mit einem «ureotelic-proteic metabolism» zeigen nach Alloxan weder eine nennenswerte Harnsäurezunahme im Blut noch eine Gicht der Eingeweide oder der Gelenke.