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71.
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73.
Wilfried H. Eppendorfer 《Journal of the science of food and agriculture》1977,28(7):607-614
In experiments with increasing applications of nitrogen to ryegrass, red clover and lucerne grown in pots, freeze-dried plant material with widely varying N-content was obtained. Increasing N-concentrations were associated with increasing nitrate contents which proportionally decreased the concentrations (g/16 g total-N) of all amino acids. Expressed as g amino acid/16 g total-N minus NO3-N, concentrations of all amino acids were closely similar at different N-levels. Differences between the three species ' amino acid composition were negligible except for a lower concentration of lysine in the crude protein of ryegrass and of methionine + cystine in the crude protein of clover and lucerne. In feeding experiments with rats increasing total-N concentrations were generally associated with higher true digestibilities of the crude protein of ryegrass, red clover and lucerne, but slightly lower biological values, especially in red clover. Net crude protein utilisation was increased by increasing total-N concentration in ryegrass, decreased in red clover and unchanged in lucerne. When ranked according to the nutritional value of the crude protein, ryegrass comes first, lucerne second and red clover last. Addition of synthetic methionine to ryegrass and lucerne improved their biological values by 30 and 47% respectively. 相似文献
74.
Wilfried H. Eppendorfer 《Journal of the science of food and agriculture》1977,28(2):152-156
In experiments with increasing applications of nitrogen to oats and rye grown in pots, grain with widely varying N-content was obtained. In rye increasing N-concentrations were associated with decreases in the protein of lysine and several other amino acids including threonine, tryptophan, methionine and cystine, whereas glutamic acid, proline and phenylalanine increased. In oat protein the amino acid composition was less affected by increasing N-content in grain. Concentrations of most essential amino acids were higher in oat than in rye protein, especially at high N-levels. The ratio lysine + arginine/proline was higher in oat than in rye protein and did not, as in rye, decrease with increasing N-concentration. Lysine as a percentage of dry matter increased up to the highest N-level in both cereals. In rat feeding experiments true digestibility of the protein of oats and rye increased to the same extent with increasing N-concentration in grain, whereas the biological value of the protein decreased considerably in rye but only slightly in oats. Net protein utilisation decreased with increasing N-content in rye but increased in oats. 相似文献
75.
Wilfried Pestemer und Werner Mannt 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1980,171(4):272-277
Zusammenfassung Die Rückstandssituation von 14 herbiciden Wirkstoffen (Alachlor, Chloridazon, Chlorpropham, Chloroxuron, Chlorthal-methyl, Desmetryn, Lenacil, Linuron, Methabenzthiazuron, Monolinuron, Napropamid, Pendimethalin, Phenmedipham und Terbutryn) in 6 Küchenkräutern (Borretsch, Dill, Kerbel, Kresse, Pimpinelle und Sauerampfer) wird erläutert anhand von Rückstandsdaten aus Freilandversuchen (2 Vegetationsperioden), die in zwei Laboratorien ermittelt wurden. Die Methoden werden schematisch beschrieben sowie Bestimmungsgrenzen und Wiederfindungsraten für beide Laboratorien angegeben.
Herbicide residues in some herbs
Summary Residue occurrence is discussed with use of 14 herbicides (Alachlor, Chloridazone, Chlorpropham, Chloroxuron, Chlorthal-methyl, Desmetryne, Lenacil, Linuron, Methabenzthiazuron, Monolinuron, Napropamide, Pendimethalin, Phenmedipham and Terbutryne) on 6 herbs (borage, dill, garden-chervil, garden cress, anise and sorrel) in the light of residue analyses (from field trials over two seasons with analyses carried out in two laboratories). The methods are outlined; limits of the determinations and recoveries are given.相似文献
76.
Versuche und Rechnungen zur Ankoppelung von Ultraschall an heiße, metallische Prüfstücke durch Wasser. Ermittlung der höchsten, eine Ultraschallübertragung durch Wasser noch zulassenden Oberflächentemperatur. Ankoppelungszeiten in Abhängigkeit von Wasserdurchfluß, Wassertemperatur und Oberflächentemperatur. Beschreibung eines wirksamen Kühlverfahrens zur schnellen Ankoppelung an bewegte Prüfstücke bei hohen Temperaturen. Anwendung auf Stranggußknüppel mit einer Oberflächentemperatur von 1250 °C bei einer Prüfgeschwindigkeit von 3 m/min. Rißempfindlichkcit verschiedener Stähle gegenüber rascher Abkühlung. 相似文献
77.
de Boer AR Alcaide-Hidalgo JM Krabbe JG Kolkman J van Emde Boas CN Niessen WM Lingeman H Irth H 《Analytical chemistry》2005,77(24):7894-7900
The potential of high-temperature liquid chromatography (HTLC) was investigated in an on-line combination with a screening system for bioactive compounds against the enzyme cathepsin B. Samples were separated by HTLC and subsequently analyzed by an on-line continuous-flow enzymatic assay. Detection was performed by electrospray ionization mass spectrometry, revealing both the bioactivity and the molecular mass of the bioactive compounds. Compared to conventional reversed-phase liquid chromatography, the amount of methanol necessary for separation could be decreased to only 10%, which improved the compatibility of LC with a biochemical assay. Sufficient preheating of the mobile phase prior to the separation and postcolumn cooling to prevent deactivation of the enzyme, even at column temperatures as high as 208 degrees C, was achieved as indicated by the reliable peak shapes obtained. The sensitivity was comparable with previously described systems operating at ambient temperatures as similar IC50 values were obtained. Exposing the inhibitors to high temperatures did not lead to thermal decomposition. The separation of inhibitors and the subsequent biochemical assay was performed either isothermally at various temperatures or by applying various temperature gradients as well as at various flow rates. The results obtained clearly show the compatibility of HTLC with an enzymatic screening assay. 相似文献
78.
Zur Frage der Kohlenstoffbestimmung bei emissionsspektrometrischen Verwechslungsprüfungen an Stählen
Notwendigkeit der Kohlenstoffbestimmung bei Verwechslungsprüfungen. Spektralanalytische Möglichkeiten bei Funken-und Bogenanregung in Luft. Einflüsse einiger Legierungselemente. Wiederholbarkeit und Bestimmungsgrenzen. Bestehende Forderungen. 相似文献
79.
80.
用伪并行遗传/模拟退火算法进行多流股换热器网络综合的研究 总被引:4,自引:0,他引:4
The multi-stream heat exchanger network synthesis (HENS) problem can be formulated as a mixed integer nonlinear programming model according to Yee et al. Its nonconvexity nature leads to existence of more than one optimum and computational difficulty for traditional algorithms to find the global optimum. Compared with deterministic algorithms, evolutionary computation provides a promising approach to tackle this problem. In this paper, a mathematical model of multi-stream heat exchangers network synthesis problem is setup. Different from the assumption of isothermal mixing of stream splits and thus linearity constraints of Yee et al., non-isothermal mixing is supported. As a consequence, nonlinear constraints are resulted and nonconvexity of the objective function is added. To solve the mathematical model, an algorithm named GA/SA (parallel genetic/simulated annealing algorithm) is detailed for application to the multi-stream heat exchanger network synthesis problem. The performance of the proposed approach is demonstrated with three examples and the obtained solutions indicate the presented approach is effective for multi-stream HENS. 相似文献