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1.
本文通过分析我省历史发生的特大干旱灾害事件,论述了不同时期特大干旱对粮食产量的严重影响。提出了21世纪特大干旱的研究与对策。  相似文献   
2.
The compressive stress-strain relationships of two puffed cereals, rice and corn based, in bulk were determined using a Universal Testing Machine. The general sigmoid shape of the relationship could be described by a four parameter empirical model originally developed for cellular solids. Jaggedness could be expressed in terms of an apparent fractal dimension and/or the mean magnitude of the power spectrum determined using the Fast Fourier Transform. Both measures as well as a particular parameter of the empirical model were sensitive indicators of the changes in the stress-strain relationships resulting from exposure to different relative humidities. Although the stress strain relationship, especially of dry samples, had an irregular, irreprodu-cible shape, the magnitude of the two roughness measures was highly reproducible.  相似文献   
3.
Summary Ready‐to‐eat breakfast cereals immersed in milk undergo undesirable changes in texture because of sudden moisture uptake. The textural changes are ascribable to a plasticizing effect of water, which modifies the mechanical strength of products by softening the starch/protein matrix. In this work, some textural parameters of different cereal flakes were derived from the force–displacement curves monitored during 300 s of immersion in milk. Hardness loss, deformability increment and changes in the force–displacement curve profile were calculated and plotted against soaking time. The application of a sugar coating process to a model cereal flake increased the initial product hardness and improved the preservation of the textural parameters during immersion. The Peleg model closely fitted the experimental data, with regression coefficients from 0.967 to 0.999.  相似文献   
4.
The activity and molecular weights of glutathioneS-transferase were studied in three species of cereal aphid:Metopolophium dirhodum, Sitobion avenae, andRhopalosiphum padi. The highest level of glutathioneS-transferase activity was recorded in extracts fromM. dirhodum and the lowest fromS. avenae, and extracts of larvae were more active than those from adults. The activity of this enzyme was higher in extracts ofS. avenae andR. padi previously fed on a moderately resistant wheat variety than on a susceptible variety. Gel filtration followed by SDS-PAGE revealed three protein bands in the active fractions. The first had a molecular weight of 28,500 and the second of 27,500 and were present in all three species of aphid. The third protein differed in the three species, having a molecular weight of 26,000 inS. avenae, 25,500 inM. dirhodum, and 24,000 inR. padi.  相似文献   
5.
通过敦煌汉简中所见到的有关谷物收支记录的简文,对汉代的账簿记录格式和财务审计工作进行了研究,并分析了当时会计工作的进步性。  相似文献   
6.
分别用气相色谱法、地衣酚-盐酸法、间苯三酚-冰醋酸法以及Duffau蒸馏法对小麦戊聚糖含量进行了测定.在研究过程中以气相色谱法为标准,就地衣酚-盐酸法、间苯三酚-冰醋酸法以及Duffau蒸馏法与气相色谱法之间的相关性进行研究,通过研究得到测定谷物中戊聚糖含量的最佳方法,即采用间苯三酚-冰醋酸比色法.研究发现间苯三酚-冰醋酸法与气相色谱法具有较好的相关性,并且该方法测定较快速、准确.  相似文献   
7.
β-葡聚糖是一类由β-吡喃型葡萄糖基通过(1→3)、(1→4)或(1→6)糖苷键连接而成的多糖。β-葡聚糖除了具有降低胆固醇、控制血糖等功能外,在胃肠道方面还具有其他重要的生理学功能。本文详细地综述了谷物β-葡聚糖对胃排空的影响,在小肠中对营养素吸收与肠道蠕动的影响,以及在大肠中对肠道微生物生长与微生物发酵的影响,同时对酵母β-葡聚糖和索拉胶在胃肠道方面的生理学功能作了简述,并展望了细菌胞外β-葡聚糖的应用前景。   相似文献   
8.
The objectives of this study were to evaluate production performance, milk fatty acid composition, and nutrient digestibility in high-producing dairy cows consuming diets containing corn and hull-less barley (cultivar Amaze 10) in different proportions as the grain source. Eight primiparous and 16 multiparous Holstein cows were assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design with 21-d periods. Cows were fed once daily (1200 h) by means of a Calan gate system (American Calan Inc., Northwood, NH). All diets contained ~20% grain (dry matter basis). Treatments consisted of 100% corn (0B), 67% corn and 33% hull-less barley (33B), 33% corn and 67% hull-less barley (67B), and 100% hull-less barley (100B) as the grain sources. Total-tract nutrient digestibility was estimated using lanthanum chloride (LaCl3) as an external marker. Dry matter intake differed quadratically among treatments, being lowest for 67B and highest for 0B and 100B. Feeding hull-less barley did not affect milk yield, and milk fat concentration differed cubically among treatments. The cubic response was attributed to the higher milk fat concentration observed for the diet containing 67B. Neither the concentrations in milk of protein and lactose nor the yields of protein and lactose differed among treatments. The proportion of de novo synthesized fatty acids in milk did not differ among treatments. The apparent total-tract digestibility of dry matter, crude protein, and neutral detergent fiber did not differ among treatments. Although a quadratic effect was observed, starch digestibility was minimally affected by treatments. In conclusion, this study indicates that hull-less barley grain is as good as corn grain as an energy source when formulating diets for high-producing dairy cows.  相似文献   
9.
The aim of this study was to measure the variation in dietary fibre (DF) content and composition among different rye varieties grown in the same location in three successive years and to estimate the contributions of genotype and harvest year to this variation. The study included grain from 19 different varieties of rye, of which seven varieties were analysed in all three years. The content of total DF in all samples ranged from 147 to 209 g kg?1 dry matter (dm), with 34–66 g kg?1 being water‐extractable (WE) DF and 108–159 g kg?1 being water‐unextractable (WUE) DF. The main DF component was arabinoxylan (AX) with a content of 80–121 g kg?1 dm, of which 26–41 g kg?1 dm was WE AX. The ratio of arabinose to xylose (ara/xyl) of total AX ranged from 0.59 to 0.69. The content of β‐glucan was 13–22 g kg?1 dm and that of fructan was 45–64 g kg?1 dm. Analysis of the data from seven varieties and three harvest years showed a highly significant influence of harvest year on most DF components. Significant genotype effects were found for the contents of total DF, total AX, β‐glucan and fructan and for the ara/xyl ratio of total and WUE AX. Estimation of variance components showed that yearly variations in the contents of total DF, total AX, WUE DF, WUE AX and β‐glucan were generally higher (27–55% of total variance) than genotype effects (14–19%). The ara/xyl ratio of total and WUE AX showed a high influence of genotype (46 and 43% respectively). Non‐adapted rye varieties with small kernel size had the highest contents of total DF and total AX. The content of β‐glucan was positively correlated with kernel weight (r = 0.68), whereas no overall correlation was found between kernel size and the content of DF. As a conclusion, the variation in DF content and composition in this study was significantly influenced by both harvest year and rye genotype. © 2002 Society of Chemical Industry  相似文献   
10.
结合中国传统的五行概念以纯牛奶为主要原料,复配谷物和果蔬汁生产五行牛奶。应用正交试验法,确定了适合的配方和适宜的工艺条件,并对产品质量做出评价。结果表明:牛奶、谷物、果蔬汁分别为80%、2%、2%,同时加入4%的白糖和0.2%的稳定剂,可以保证产品具有最佳的感官品质。最佳均质温度为70℃,最佳均质压力为27MPa最佳杀菌方式为138℃下保温5s。以此配方和工艺生产的五行牛奶具有感官品质佳、稳定性好和营养丰富等特点。  相似文献   
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