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31.
Abstract High quality corrosion resistant Cr-Ni steels are used in many branches of industry. Constructors are faced with the problem of correctly dimensioning statically and dynamically loaded parts, but have little data available for dynamically loaded welded constructions of high alloy austenitic steels. To close this gap fatigue strength tests were carried out on three different steels and five different welded joints. 相似文献
32.
Jacek Słupski Jacek Achrem‐Achremowicz Zofia Lisiewska Anna Korus 《International Journal of Food Science & Technology》2010,45(8):1682-1688
The aim of this work was to evaluate the effect of processing on the amino acid content and protein quality of New Zealand spinach (Tetragonia tetragonioides Pall. Kuntze). In this research, fresh and cooked New Zealand spinach as well as two frozen products prepared for consumption, one obtained using the traditional method (blanching–freezing–storage–cooking) and the other a convenience food product obtained using a modified process (cooking–freezing–storage–defrosting and heating in a microwave oven), were analysed. Glutamic acid was the dominant amino acid in fresh New Zealand spinach, and the limiting amino acids were cystine and methionine. Technological and culinary processing caused a significant increase in amino acid content in 100 g of edible portion, with the exception of methionine and cystine in frozen products prepared for eating. Changes in amino acid content expressed in g/16 g of N (which corresponded to 100 g tissue protein) were not significant, with the exception of the lower glutamic acid content in the frozen product obtained using traditional processing method. 相似文献
33.
Pawe Maksimowski Maciej Duda Waldemar Tomaszewski 《Propellants, Explosives, Pyrotechnics》2011,36(4):320-326
2‐Acetyl‐4,6,8,10,12‐pentanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (PNAIW) is formed in the last step of nitration of acetyl isowurtzitane derivatives. The amount of the PNAIW formed depends on the conditions of the nitration reaction (temperature, time, and nitrating mixture used) and on the type of the starting acetyl intermediate. The highest PNAIW yields (30 %) were obtained by nitrating 2,6,8,12‐tetraacetylhexaazaisowurtzitane (TAIW) at 60 °C for half an hour using HNO3/H2SO4 nitrating mixture. HPLC, NMR, FTIR, and DSC measurements were used in the study and their results are reported. 相似文献
34.
We have utilized the Hewlett‐Packard LC/ESI‐MS technology to store electronic records of total ion current profiles of molecular species of various natural and peroxidized phospholipids of native and auto‐oxidized plasma lipoproteins before and after digestion with secretory phospholipase A2 (sPLA2). The present report illustrates the successful utilization of the stored data in several originally un‐intended applications, including chemical, physico‐chemical and enzymatic alterations of the lipoprotein lipids. The inclusion of lipid samples from enzyme and control incubations adds a dynamic aspect to multidimensional lipidomic analysis of plasma lipoproteins. 相似文献
35.
36.
Recovery of platinum, tin and indium from spent catalysts in chloride medium using strong basic anion exchange resins 总被引:1,自引:0,他引:1
This work describes a route for platinum recovery from spent commercial Pt and PtSnIn/Al2O3 catalysts using strong basic mesoporous and macroporous anion exchange resins (Cl− form). The catalysts were leached with aqua regia (75 °C, 20-25 min). Platinum adsorption was influenced by the presence of other metals which form chlorocomplexes (tin, indium) and also base metals (aluminum). However, it was possible to overcome this fact by a sequential desorption procedure. Aluminum was selectively removed from the resins by elution with 3 mol L−1 HCl. Platinum was desorbed passing 1 mol L−1 Na2S2O3 (pH 9). Tin was removed by elution with 0.1 mol L−1 ascorbic acid. Indium was removed using 0.1 mol L−1 EDTA as eluent. Desorption efficiency exceeded 99% for all metals. Metals were recovered in high yields (>98 wt%). 相似文献
37.
Waldemar Ternes Melanie Gronemeyer Karin Schwarz 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1995,201(6):544-547
p-Cymene-2,3-diol, carvacrol and thymol are components of thyme that exhibit antioxidant activities. The concentration of each substance was determined in different foodstuffs containing thyme extract. The stabilities ofp-cymene-2,3-diol, carvacrol and thymol were examined by heating lard containing thyme extract at temperatures from 80 °C to 160 °C. 相似文献
38.
Alfons Schloemer Waldemar Godbersen und Max Ohm 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1940,79(4):337-344
Zusammenfassung Bericht über die gemeinsame Kontrolle des Groß-Berliner Buttermarktes durch die Kontrollorgane der amtlichen Lebensmittelkontrolle, den Gewerbe-Außendienst der Polizei und die Preußische Landesanstalt zusammen mit den Buttersachverständigen der Hauptvereinigung der deutschen Milch- und Fettwirtschaft, sowie des Milch- und Fettwirtschaftsverbandes Kurmark im Jahre 1939; ambulante Kontrolle, Methodik der polizeilichen Probenahme, Begleitbogen, Prüfung der Butterproben bezüglich Kennzeichnung, Form, Gewicht, Perforierung, Wassergehalt, Verfälschung mit fremden Fetten sowie Sinnenprüfung; Beurteilung der Proben auf Grund der verschiedenen, hier angeführten Gesetze, Verordnungen und Anordnungen. 相似文献
39.
Influence of Molybdenum Silicide Additions on High-Temperature Oxidation Resistance of Silicon Nitride Materials 总被引:2,自引:0,他引:2
Hagen Klemm Katja Tangermann Christian Schubert Waldemar Hermel 《Journal of the American Ceramic Society》1996,79(9):2429-2435
The influence of additions of molybdenum disilicide (MoSi2 ) on the microstructure and the mechanical properties of a silicon nitride (Si3 N4 ) material, with neodymium oxide (Nd2 O3 ) and aluminum nitride (AIN) as sintering aids, was studied. The composites, containing 5, 10, and 17.6 wt% MoSi2 , were fabricated by hot pressing. All materials exhibited a similar phase composition, detected by X-ray diffractometry. Up to MoSi2 additions of 10 wt%, mechanical properties such as strength, fracture toughness, or creep at 1400°C were not affected significantly, in comparison to that of monolithic Si3 N4 . The oxidation resistance of the composites, in terms of weight gain, degraded. After 1000 h of oxidation at 1400° and 1450°C in air, a greater weight gain (by a factor of approximately three) was obtained, in comparison to that of the material without MoSi2 . Nevertheless, after 1000 h of oxidation, the degradation in strength of the composites was considerably less severe than that of the material without MoSi2 . An additional layer was formed, caused by processes at the surface of the Si3 N4 material, preventing the formation of pores, cracks, or glassy-phase-rich areas, which are common features of oxidation damage in Si3 N4 materials. This surface layer, containing Mo5 Si3 and silicon oxynitride (Si2 ON2 ), was the result of reactions between MoSi2 , Si3 N4 , and the oxygen penetrating by diffusion into the material during the hightemperature treatment. 相似文献
40.
Vitamin C and polyphenol content as well as total antioxidative activity were investigated in fresh leaves of kale; in leaves after blanching or cooking; and in frozen and canned leaves. In 100 g fresh matter, kale leaves contained 384.9 mg polyphenols and 112.1 mg vitamin C, with a Trolox equivalent antioxidant capacity (TEAC) level of 1175 μM Trolox. Of the polyphenols identified in kale leaves, ferulic acid occurred in the highest amount (240.44 mg/100 g, constituting 62% of total polyphenols). Freezing was a better method of preserving kale leaves since the loss of nutritive constituents was lower than in the case of canning. Depending on preliminary processing and storage temperature, after one-year storage frozen leaves contained 82.9–171.3 mg polyphenols and 39.3–65.4 mg vitamin C, with TEAC at the level of 501–681 μM Trolox in 100 g. In canned leaves these values were: 91.3–94.1 mg polyphenols, 16.1–19.3 mg vitamin C and 268–293 μM Trolox. 相似文献