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1.
We prepared long carbon fiber (LCF)-reinforced thermoplastic composites using a compatibilizer of itaconic acid grafted polypropylene (PP-g-IA). We confirmed the structure of PP-g-IA and investigated the compatibilizing effects of PPg- IA on LCF/polypropylene composites. The tensile strength, tensile moduli, flexural strength, and flexural moduli of the composites increased with increasing PP-g-IA content in the thermoplastic composites. Using single pull-out analyzing system, we found PP-g-IA improved interfacial strength between the carbon fiber and PP matrix. The thermal properties of the composites were measured by thermogravimetric analysis (TGA). We could observe that LCF enhanced the mechanical properties and thermal decomposition temperature of the polypropylene (PP) composites, compared with neat PP. The fractured surfaces of PP/PP-g-IA/LCF composites showed that PP-g-IA was effective for improving the interfacial adhesion between LCF and PP matrix.  相似文献   

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The partial substitution of humic acid derivatives for fertilizer did not improve yield, specific gravity or boiling, chipping and storage quality in Kennebec and Sebago potatoes in Ontario.  相似文献   

4.
Maize was harvested at one‐third milk line (297 g kg?1 DM) stage. All inoculants were applied at 1 × 106 cfu g?1 of fresh forage. After treatment, the chopped forages were ensiled in 1·5‐L anaerobic jars. Three jars per treatment were sampled on days 2, 4, 7, 12 and 90 after ensiling, for chemical and microbiological analysis. Homofermentative LAB‐inoculated silages had lower pH and higher lactate:acetate ratio (except for Lactobacillus plantarum/Pediococcus cerevisiae and L. plantarum/Propionibacterium acidipropionici) than the control and both heterofermentative LAB‐inoculated silages. Both L. buchneri inhibited yeast growth and CO2 production during exposure of silage to air. The L. plantarum/P. cerevisiae, L. plantarum (Ecosyl) and L. plantarum/Enterococcus faecium‐inoculated silages had higher dry‐matter digestibility than the control and L. buchneri‐inoculated silages. Inoculants did not affect digestibility of neutral detergent fibre, except for L. buchneri (Biotal), organic matter nor ME content of silages. The LAB silage inoculants generally had a positive effect on maize silage characteristics in terms of lower pH and shifting fermentation toward lactate with homofermentative LAB or toward acetate with L. buchneri. The use of L. buchneri can improve the aerobic stability of maize silages by the inhibition of yeast activity.  相似文献   

5.
Lots of studies have been carried out to improve the strength of polyvinyl alcohol (PVA) fibers. One of these studies is crosslinking spinning for a good quality fiber. As a crosslinking agent, boric acid (BA, H3BO3) was used. PVA can crosslink with BA without adding cation in using dimethyl sulfoxide (DMSO). The effects of BA addition and molecular weight (MW) on the formation of the physical structure in PVA/DMSO solutions were investigated. The results showed that the time dependence of the rheological responses was greatly influenced by the BA addition to the PVA/DMSO solutions. The results also showed that the BA addition to the PVA/DMSO solutions increased the dynamic viscosity (η′), the storage modulus (G′), and the loss modulus (G″) of the PVA/DMSO solutions. Increasing MW of PVA also decreased the time dependence. In addition, the BA addition to the PVA/DMSO solutions decreased the gelation time of the PVA/DMSO solutions. These overall results suggested that the structure formation through specific interactions between PVA molecules and BA resulted in the time dependent changes of the rheological properties of the PVA/DMSO solutions.  相似文献   

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Abstract In view of the evidence indicating several potential benefits of high intakes of conjugated linoleic acid (CLA) on human health, an experiment was conducted to examine the effects of the diet of beef cattle on the total CLA concentration in muscle and subcutaneous fat. High‐concentrate [steers consumed 515 g concentrates and 485 g grass silage kg?1 dry matter (DM) for 8 weeks followed by 887 g concentrates and 113 g grass silage kg?1 DM for 14 weeks until slaughter] and high‐forage (steers consumed 803 g grass silage and 197 g concentrates kg?1 for 8 weeks followed by grass silage only for 10 weeks and then grazed perennial ryegrass‐based pasture for 23 weeks until slaughter) treatments were imposed on 48 steers, which were crosses of continental beef breeds (initially 414 kg live weight) The concentrates were based on barley, extracted soyabean meal, molassed sugarbeet pulp and maize meal. The silages were of medium to low digestibility and contained 117–137 g crude protein kg?1 DM and 83–158 g ammonia‐N kg?1 total N. The pasture was of high quality and contained 168 g crude protein, 234 g acid‐detergent fibre and 222 g water‐soluble carbohydrate kg?1 DM. Samples of muscle were taken post slaughter from the m. semimembranosus, m. gluteobiceps, m. longissimus and m. deltoideous muscles, and subcutaneous fat was taken from over the m. longissimus. Concentrations of total CLA in the tissues were for the high‐concentrate and high‐forage treatments, respectively (mg 100 g?1 fresh tissue), m. gluteobiceps 18 and 47 (s.e. 3·5); m. semimembranosus 9 and 20 (s.e. 1·6); m. longissimus 15 and 35 (s.e. 3·2), m. deltoideous 20 and 59 (s.e. 4·3); subcutaneous fat 584 and 1975 (s.e. 138·7). It is concluded that muscle and subcutaneous fat tissue from grass‐fed cattle contained three times as much CLA as those from concentrate‐fed cattle, and that the consumption of beef from grass‐fed cattle should be effective in increasing the intake of CLA by humans.  相似文献   

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Neurotoxicity induced in fish by domoic acid (DA) was assessed with respect to occurrence of neurotoxic signs, lethality, and histopathology by light microscopy. Sparus aurata were exposed to a single dose of DA by intraperitoneal (i.p.) injection of 0, 0.45, 0.9, and 9.0 mg DA kg(-1) bw. Mortality (66.67 ± 16.67%) was only observed in dose of 9.0 mg kg(-1) bw. Signs of neurological toxicity were detected for the doses of 0.9 and 9.0 mg DA kg(-1) bw. Furthermore, the mean concentrations (±SD) of DA detected by HPLC-UV in extracts of brain after exposure to 9.0 mg DA kg(-1) bw were 0.61 ± 0.01, 0.96 ± 0.00, and 0.36 ± 0.01 mg DA kg(-1) tissue at 1, 2, and 4 hours. The lack of major permanent brain damage in S. aurata, and reversibility of neurotoxic signs, suggest that lower susceptibility to DA or neuronal recovery occurs in affected individuals.  相似文献   

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Various enzyme families such as sulfhydryl oxidase have been successfully applied to bread production although their mechanism of action has not been fully described yet. In this study, we investigated the effects of the recently characterized fungal sulfhydryl oxidase AoSOX1 in fresh and frozen dough alone and in combination with ascorbic acid. The addition of AoSOX1 to an additive-free dough resulted in a weaker and more extensible dough while opposite effects were detected in the presence of ascorbic acid. The hardening of the doughs registered upon the combined use of AoSOX1 and ascorbic acid was dependent on the amount of enzyme used and not on the amount of ascorbic acid. The ability of the sulfhydryl oxidase to enhance the effects of the ascorbic acid system suggests their combined use as a valuable tool to stabilize the structure of fresh and frozen dough.  相似文献   

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α-亚麻酸、二十二碳六烯酸、二十碳五烯酸以及n-6 PUFA亚油酸等多不饱和脂肪酸(PUFA)对人体具有显著的健康功效,目前被广泛应用于在食品、医药等领域。但是含有PUFA的油脂极易被氧化,且具有强疏水性,因此其应用受到一定限制。乳液递送体系是一种经典的脂质载体,现已被应用于高生物利用率的PUFA产品的研究与开发中。脂质伴随物是来源于油脂的天然植物化合物,主要包括多酚、植物甾醇、磷脂、脂溶性维生素等。研究表明,将一定量的脂质伴随物添加入乳液体系中能够有效改善体系的稳定性。基于此,本文主要归纳总结了极性多酚类化合物、双亲性植物甾醇及磷脂、非极性维生素等脂质伴随物对乳液稳定性的影响及潜在的作用机制,并针对研究中存在的科学问题以及发展方向进行了分析和展望。  相似文献   

10.
Storage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field-cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays. Nutrient losses, and water-soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive. Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploited.  相似文献   

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The purpose of this study was to determine the effects which dihydroquercetin (DHQ) has on the natural healing process of suberization and wound periderm initiation in cut seed potatoes. Dihydroquercetin is a phenolic compound extracted from the bark of Douglas Fir,Pseudotsuga menziesii (Mirb.) Franco. Anatomical studies of treated seed potato tissue showed that treatment with bark-383, the cork-rich fraction of the whole bark containing approximately 2% pure DHQ, increases the thickness of the suberized layer formed below the cut surface. Treatment with 4% bark fraction I, which is blended to that concentration with the inert carrier dust Pyrax and contains approximately the same amount of DHQ as does the bark-383, also promoted the formation of a thicker layer of suberized cells. The thickness of the wound periderm did not significantly vary as a result of the use of any treatments containing DHQ. The use of Captan (Orthocide 50W) as a cut seed treatment in these studies was found to inhibit the formation of a suberized layer and subsequently the initiation of a wound periderm. The combination of bark-383 and Orthocide 50W in a treatment mixture reversed the inhibitory affect of the Orthocide 50W alone and therefore allowed for the formation of a well suberized layer and a wound periderm. It was found that wound healing on the cut surface of seed potatoes is largely dependent on the type of tissue present at any given point on that cut surface. Therefore, the response to treatment of the stolon end, center, and blossom end tissues was related to the type of tissue which was present in each of those tuber regions. The fungal mold growth on treated seed pieces incubated in a controlled environment was adequately retarded when Orthocide 50W was combined with bark-383 in a mixture ratio of 1:9 respectively. The longer the treatment material was allowed to remain on the seed piece, the greater was the protection against mold growth afforded by the mixture.  相似文献   

13.
Summary Turnip plants have been grown under conditions of normal mineral nutrition and with deficiencies of nitrogen, phosphorus, sulfur, potassium, calcium or magnesium. The uncombined amino acids were separated from the protein fraction.The protein fraction of the leaves was analyzed for constituent amino acids. It was found that there were considerable differences in protein level between deficient and normal leaves but that the relative composition of the protein fraction was only slightly affected.The non-protein amino acids were profoundly influenced by mineral nutrition. The differences in amino acid concentrations suggested that the lack of various macronutrients affected the metabolism of amino acids in many ways.
Zusammenfassung Brassica rapa var.Shogoin — als turnip greens in den Südstaaten der USA wie ein Gemüse verzehrt — wurde in Gefäßversuchen unter normalen und unter Mangelbedingungen (Stickstoff-, Phosphorsäure-, Schwefel-, Kalium-, Calzium- oder Magnesium-Mangel) kultiviert. In der Pflanzensubstanz wurden die nicht gebundenen Aminosäuren von der Eiweißfraktion abgetrennt.Die Eiweißfraktion der Blätter wurde auf ihre Aminosäuregarnitur untersucht. Es wurden beträchtliche Unterschiede im Eiweißhaushalt der Blätter von Mangelreihen und normalen gefunden, jedoch war die relative Zusammensetzung der Eiweißfraktion von dieser Veränderung nur wenig betroffen.Die nicht eiweißgebundenen Aminosäuren wurden dagegen weitgehend durch die Mineralstoffversorgung der Pflanze beeinflußt. Die Unterschiede in der Aminosäurekonzentration lassen erkennen, daß die Abwesenheit der verschiedenen Makronährstoffe den Aminosäurestoffwechsel in mannigfacher Weise verändert.

Résumé Brassica rapa var.Shogoin — bien connue aux Etats-Unis comme légume — était cultivée dans les pots d'expérience sous des conditions normales et des conditions de carence en Azote, en Acide phosphorique, en Sulfure, en Potasse, en Calcium ou en Magnesium. Dans les matières fraîches les acides aminés libres étaient isolés de la fraction de Protéines.La fraction de Protéines des feuilles était analysée en ce qui concerne les acides aminés. On a trouvé des différences considérables dans le contenu de Protéines des plantes cultivées aussi bien dans les conditions normales que dans les conditions de carence. La composition relative de la fraction de Protéines n'ðait que peu effectuées par ces différentes conditions.Les acides aminés libres étaient par contre influencés considérablement par les engrais minéraux fournis aux plantes. Les différences de concentration des acides aminés montrent que l'absence des différents macroéléments change le métabolisme des acides aminés d'une façon diverse.
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14.
Barley oil was extracted with hexane from the grain of a high oil waxy hull-les barley. Twelve male broiler chicks were fed corn-based diets with either 10% barley oil, 10% corn oil or 10% margarinead libitum for ten days. Total plasma cholesterol concentration of the chicks fed barley oil was 34% lower (p<0.05) than that of the chicks fed margarine. Plasma low density lipoprotein cholesterol concentration of chicks fed barley oil was 53% and 59% lower (p<0.05) than those of chicks fed corn oil and margarine, respectively. Plasma high density lipoprotein cholesterol and triglyceride concentration of the barley oil group were similar to those of the margarine but higher (p<0.05) than those of the corn oil group. Chicks fed the barley oil gained more (p<0.05) body weight than those fed the corn oil and margarine. Barley oil had an effect in suppression of TC and LDLC in chicks compared to margarine. Barley oil supressed LDLC but not HDLC in chicks compared to corn oil. A greater weight gain of the chicks fed barley oil suggested that these chicks had normally functioning digestion and absorption. -Tocotrienol and -tocotrienol content of the barley oil were 24 and 17 times greater, respectively, than those observed in the corn oil, while the same fractions were not detectable in the margarine. Polyunsaturated fatty acid content of the barley oil was more than threefold that of margarine. These data suggest that -tocotrienol and polyunsaturated fatty acids are hypocholesterolemic components in barley oil.Contribution No. J-2617, Montana Agricultural Experiment Station. This research was supported, in part, by grants from the Montana Wheat and Barley Committee, Great Falls, MT and Ross Laboratories, Columbus, OH.  相似文献   

15.
Eight lactic acid bacteria (LAB) strains isolated from five naturally fermented silages of different ensilage materials on the Tibetan Plateau were characterized, and their effects on the silage quality of common vetch (Vicia sativa L.) were studied. These LAB isolates were evaluated using morphological, physiological and biochemical tests. The eight isolated strains and one commercial inoculant (Lactobacillus plantarum MTD‐1) were subsequently added to common vetch for ensiling 60 days. All the isolated strains (LW4, M1, WG27, O30, I2, LCG3, LCG9, CG35) could grow normally at 5–20°C, pH 3.5–6.0 and NaCl (3.0%, 6.5%), and they were identified as Lactobacillus plantarum and Pediococcus pentosaceus by sequencing 16S rDNA. All the LAB inoculants improved the silage quality of common vetch, indicated by significantly (< .05) higher lactic acid (LA) contents and ratios of lactic acid to acetic acid (LA/AA), and significantly (< .05) lower pH and ammonia nitrogen (NH3–N) contents. Strain LCG3 performed best among all LAB inoculants, indicated by the highest (< .05) LA content and ratio of LA/AA, and the lowest (< .05) pH and NH3–N content. Strain LCG3 is recommended as starter culture for common vetch silage.  相似文献   

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The effects of temperature on silage effluent production were examined. In the first experiment, samples of perennial ryegrass ( Lolium perenne ) underwent fermentation at 20°C for between 52 and 66 d. The samples were then transferred to rooms at temperatures between 5°C and 27°C. Effluent production during creep consolidation was measured. Increasing temperature resulted in a significant increase in effluent production. There was a strong linear relationship between the mechanical properties of the silage and the amount of effluent produced. In the second experiment, Italian ryegrass ( Lolium multiflorum ) samples were ensiled at temperatures between 5°C and 25°C. The higher temperature treatments had faster and more extensive fermentations, and produced more effluent than the cooler temperatures. Again, there was a strong linear relationship between the mechanical properties of the silage and the amount of effluent produced. Increasing the temperature at the end of the experiment resulted in no extra effluent production from any treatment except that at 5°C. This indicated that the effects of temperature were evident only while effluent was available for release. The effects of temperature will therefore be most evident in the early stages of ensilage. In both experiments, effluent was released from the higher temperature treatments earlier. This was probably due to the effects of temperature on the viscosity of the effluent and to fermentation effects in the second experiment. In both experiments, the increase in effluent production with temperature was equivalent to the effects to be expected from decreasing the herbage dry matter concentration by between 3% and 4%.  相似文献   

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The role of mechanical action on the washing process was studied. The experimental apparatus was designed to simulate each mechanical action such as the hydrodynamic flow action, the fabric flexing action, the abrasion action during washing process. The influence of mechanical action strongly depends on the property and attached state of each soil. The abrasion action was found as the most effective mechanical action for soil removal.  相似文献   

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