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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 16 (1933), S. 1201-1208 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 16 (1933), S. 54-69 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 16 (1933), S. 468-478 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 16 (1933), S. 375-382 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wurde gezeigt, dass bei der Fällung der Schwermetallferro-cyanide aus verdünnter Lösung (Konzentration der Metallsalze und des Ferrocyanids 0,01- bis 0,005-m.) charakteristische Maxima der Viskosität auftreten, deren Lage angenähert stöchiometrischen Verhältnissen der reagierenden Ionen entspricht, wobei aber der Permutit-charakter der Niederschläge eine Rolle spielt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dinucleoside monophosphates bearing usual protecting groups at the exocyclic amino functions of the heterocyclic bases, the 5′-hydroxy group, the phosphate moiety and the O-6-position of the guanine ring have been analysed by FAB mass specrometry in the negative ion mode. These non-charged key intermediates for oligodeoxynucleotide synthesis exhibit very simple spectra in the mass range of m/z 400-1500 using tetra-ethylene glycol as matrix. Most of the observed ions could easily be assigned. Apart from deprotonated molecular ions sequence specific ions arising from C-O-P bond cleavage and ions derived from loss of protecting groups were observed. The simplicity of spectra interpretation makes FAB mass spectrometry to a rapid and valuable tool for unambiguous identification of dimeric synthons for oligonucleotide synthesis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 3 (1980), S. 415-416 
    ISSN: 0935-6304
    Keywords: Gas chromatography/mass spectrometry ; Volatile sulfur compounds from waste water ; Adsorption of air samples on tenax GC ; Mechanism of corrosion of concrete ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 24 (1993), S. 131-141 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Arc-PVD-Coating of Cemented Carbides and Analysis of their Functional Behaviour in Interrupted Cut MachiningInterrupted machining of quenched and tempered steel demands the application of tools with high resistance against mechanically and tribologically induced wear. These demands can not be fully satisfied by uncoated carbides. Also CVD-coatings give only some improvement due to a certain embrittlement of the substrate during the coating process. PVD-coatings deposited at low temperatures without affection of the substrate lower the influence of the relevant wear mechanisms preferably at moderate cutting speeds.The combination of tough substrates with structural and compositional optimized coatings results in a multiplication of tool life within the whole range of low and medium cutting speeds. Coatings with homogenious structure, compressive residual stresses and high content of metalloides ensure excellent resistance against wear.Titanium-carbonitride deposited on carbide was found to be superiour compared with other carbonitride, nitride and carbide coatings within the system Ti—Zr—C—N due to excellent tribological properties. It was optimal suited for the interrupted cut application.
    Notes: Die Zerspanung von höherfesten Stahlwerkstoffen in unterbrochenen Schnitten stellt an die Werkzeuge hohe mechanische und tribologische Anforderungen, denen unbeschichtete Hartmetalle in vielen Fällen nicht gerecht werden können. Während sich bei der Zerspanung von höherfestem Stahl in stark unterbrochenen Schnitten durch die CVD-Beschichtung von Hartmetallen auf-grund prozeßbedingter Versprödungseffekte kaum Leistungssteigerungen erzielen lassen, können PVD-Hartstoffbeschichtungen, die bei substratschonend niedrigen Prozeßtemperaturen abgeschieden werden, dem Auftreten der relevanten Schädigungsmechanismen besonders bei niedrigen und mittleren Schnittgeschwindigkeiten entscheidend entgegenwirken.Insbesondere mit zähen Substratsorten sowie mit strukturell und kompositionell optimierten Schichten können Standzeitvervielfachungen im gesamten unteren und mittleren Schnittgeschwindigkeitsbereich erzielt werden. Homogene Schichtstrukturen, hohe Druckeigenspannungen und hohe Metalloidgehalte der Hartstoff-schichten gewährleisten eine hohe Verschleißfestigkeit. Titankarbonitrid zeichnet sich auf Hartmetallen gegenüber anderen karbonitridischen, nitridischen und karbidischen Schichten des Systems Ti—Zr—C—N durch ein besonders günstiges tribologisches Verhalten aus und hat sich als optimaler Beschichtungswerkstoff für unterbrochene Schnitte erwiesen.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 4 (1981), S. 553-556 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, glass ; Carbohydrate enantiomer separation ; New chiral stationary phases ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New chiral polymers have been prepared by conversion of cyano groups of polysiloxanes XE-60 and OV-225 into carboxylic groups and subsequent coupling to give the respective S-valine-R-α-phenyl-ethyl amide. In contrast to the corresponding stationary phases with S-α-phenylethyl amide groups, which have been used for the resoultion of trifluoroacetylated hexose derivatives, the new phase show high enantioselectivity for pentose and 6-deoxyhexose derivatives.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 29 (1998), S. 525-536 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Temperature of cutting tools by thin filmsDuring the cutting process, cutting tools are exposed to complex mechanical, thermal, dynamic and tribological loads. Especially in the case of dry machining the demands on cutting tools are very high. Dry machining becomes more and more interesting because of tightened up ecolaws and increased costs for the handling of coolants. Due to a renunciation on coolants the cutting tools need to be modified to the process of dry machining. Thereby modern plasma and ion based surface technologies can be used to deposit a thin film adopting the functions of coolants, e.g. cooling and lubricating.In this research project several coating types, e.g. titanium and chromium based coatings, where developed and characterized regarding their mechanical, tribological and thermal properties. For the research, four partners collaborated permuting all steps of surface and coatings design. Materials Science Institute (WW), Aachen University of Technology, performed the development of PVD coatings and the thermophysical characterization by thermal wave analysis. Surface modifications of uncoated and coated tools by ion beam assisted deposition were carried out at Stiftung Institut für Werkstofftechnik (IWT), Bremen. To determine the cutting properties of coated tools, practical tests were performed at Laboratory for Machine Tools and Production Engineering (WZL), Aachen University of Technology.
    Notes: Zerspanwerkzeuge sind während ihres Einsatzes einem komplexen und schwer zu erfassenden Beanspruchungskollektiv ausgesetzt. Dieses wird besonders durch die aus ökonomischen und ökologischen Gründen angestrebte Trockenzerspanung beeinflußt. Der vollständige Verzicht auf Kühlschmierstoffe bedeutet aus technologischer Sicht, daß Werkzeuge, Schneidstoffe und Zerspanoperationen auf die Bedingungen der Trockenzerspanung umgestellt werden müssen. Dabei bieten moderne ionen-und plasmagestütze Oberflächentechnologien insofern einen Lösungsansatz, daß durch Beschichtungen bzw. Oberflächenmodifikationen wichtige Aufgaben der Kühlschmiermittel durch den beschichteten Schneidstoff selbst übernommen werden können. Dies sind vor allem der Ersatz von Schmierung und Kühlung.Für den Bereich der Trockenzerspanung wurden im Rahmen eines Verbundvorhabens u.a Titanbasisschichten sowie Chrombasisschichten entwickelt und hinsichtlich der physikalischen Eigenschaften untersucht. Durch die enge Zusammenarbeit der beteiligten Forschungsstellen konnte das jeweils vorhandene Erfahrungspotential vollständig in die Schichtsystementwicklung einfließen. Diese umfaßte alle iterativen Schritte des Schichtmodifikation, begleitende Schichtanalytik bis hin zum Praxistest. So war beispielsweise das Lehr- und Forschungsgebiet Werkstoffwissenschaften der RWTH Aachen für die Schichtentwicklung sowie fü die thermophysikalische Charakterisierung der Schichten zuständig. Die Stiftung Institut für Werkstofftechnik, Bremen, führte eine Optimierung der Interfaces und der Hartstoffschichten mittels ionenstrahlgestützter Beschichtungsverfahren durch. So konnte das Substrat vor bzw. die Hartstoffschicht nach der Beschichtung an den Anwendungsfall angepaßt werden. Die Untersuchung hinsichtlich der Praxistauglichkeit der beschichteten Schneidstoffe erfolgte am Werkzeugmaschinenlabor der RWTH Aachen durch entsprechende Zerspanversuche.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 1 (1978), S. 69-71 
    ISSN: 0935-6304
    Keywords: Gas Chromatography Mass Spectrometry ; Capillary, glass/Varian, MAT 311A ; Separation and detection (El, Cl) of some roast coffee constituents ; Three new phenolic compounds found ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A roast coffee infusion (nicaragua arabica) was acidified (pH 1,5) with hydrochloric acid and extracted with diethyl ether in a perforator. After evaporation of the solvent the residue was treated with N-methyl-N-trimethylsilyl trifluoroacetamide and analyzed by glass capillary GC/MS. The main components were identified by their electron impact and isobutane chemical ionization mass spectra. 1,2,4-trihydroxy benzene, 1-ethyl-3, 4-dihydroxy benzene and 2,3-dihydroxy toluene were identified as new constituents of roast coffee with possible emetic properties.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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