22°晕和近假日的折射─衍射理论的探讨

简述了２２°晕和近假日的折射理论，论证了“三日同晖”不是正弦光栅衍射形成的，提出了２２°晕和近假日的折射─衍射理论．     

葡萄酒成分分析与质量研究

通过对１９种葡萄酒的主要成分及其感官质量的分析评价，结果显示：葡萄酒中除含有糖、酒、酸、单宁、多酚外，还含有丰富的氨基酸、维生素Ｃ、矿物质及多种微量香味成分，其含量及感官质量因酒种及来源的不同而有所差异。在分析的基础上探讨了影响葡萄酒质量的主要因素，提出了提高国产葡萄酒质量的技术工艺措施；并建议加强对葡萄酒香味成分的分析研究，建立新的葡萄酒质量评价体系。     

漂烫及硬化处理对果块品质影响及机理研究

针对果脯加工中易褐变和软化的问题,以苹果为试材,通过考察漂烫温度、漂烫时间、硬化剂对产品中VC、酶活、硬度等指标的影响,研究漂烫和硬化处理对果块的影响和机理.结果表明:漂烫温度为100℃,漂烫时间为4min,可以起到较好的抑制褐变的目的,5?Cl2溶液硬化3h可以起到较好的硬化效果.     

油脂营养成分及其对肠道健康影响的研究进展北大核心CSCD

油脂是人体最主要的营养物质之一,其消化吸收主要发生在肠道,而肠道内存在种类繁多的菌群,可以直接参与人体的消化吸收、脂质代谢、能量供应等。油脂的消化吸收可能与多种代谢紊乱和肠道疾病、糖尿病、肥胖等慢性疾病存在联系,而食用油脂摄入不平衡会影响肠道菌群组成和代谢,破坏肠道稳态,进而可能导致上述疾病的发生。综述了油脂的脂肪酸组成、功能性伴随成分及其对人体健康的影响,分析了近年来油脂对肠道菌群组成及其代谢产物影响的研究,并对未来的研究方向进行了展望,这对进一步开展油脂营养特性及其对肠道健康影响的研究以及合理膳食保障人体健康具有积极意义。     

Effects of nitrogen and phosphorus fertilisers on yield and on inorganic and organic composition of italian ryegrass grown on phosphorus-deficient soil

Italian ryegrass (Lolium multiflorum) S22, grown in a greenhouse in phosphorus-deficient soil in pots was given 40 and 160 mg N/kg of soil (as ammonium nitrate) and 5, 25 and 100 mg P/kg of soil (as calcium tetrahydrogen diorthophosphate). Giving more nitrogen increased yields only when adequate phosphorus was applied. A significant response to added phosphorus was obtained when ryegrass dry matter contained about 0.15% P or less. Nitrogen increased the amount of sugars but decreased that of fructosan. Phosphorus increased the production of both sugars and fructosan. Protein N (expressed as a percentage of total N) increased with increasing amounts of phosphorus given. The largest values for protein N were obtained when grass contained about 0.3 % P in the dry matter. In phosphorus-deficient grass nitrate-N accumulated and the predominant compounds within the free amino acid fraction were asparagine and glutamine. Adding phosphorus decreased the concentrations of both nitrate-N and the amides. The amino acid composition of the grass protein was not affected by the nitrogen and phosphorus treatments.     

植物提取物用于果蔬植物防腐保鲜研究进展

致腐菌是诱发果蔬采后病害，造成果蔬腐败变质的主要原因。现对植物提取物对果蔬致腐菌的抑制作用，不同提取方法对致腐菌的抑制效果和提取物用于果蔬防腐保鲜的研究进展作一综述。     

植物提取物用于果蔬植物防腐保鲜研究进展

致腐菌是诱发果蔬采后病害,造成果蔬腐败变质的主要原因。现对植物提取物对果蔬致腐菌的抑制作用,不同提取方法对致腐菌的抑制效果和提取物用于果蔬防腐保鲜的研究进展作一综述。     

二氢吡啶对肉仔鸡生产性能及对尿素氮、甲状腺激素的影响

选用1日龄AA肉用雏鸡300只,随机分成5组。采用单因子试验设计方法。试验日粮按二氢吡啶添加水平的不同分为5个不同的处理组,即二氢吡啶添加水平为0(对照组)、50、100、150和200mg/kg。试验结果表明,二氢吡啶添加水平为100和150mg/kg时均能显著提高日增重、饲料转化率(P<0.05);添加水平为50、150和200mg/kg时血清中尿素氮(BUN)含量与对照组相比分别下降了20.30%、26.80%和25.26%,并达到差异显著(P<0.05)。血清中三碘甲腺原氨酸(T3)、四碘甲腺原氨酸(T4)和胰岛素(INS)含量各处理组间差异不显著(P>0.05);但二氢吡啶添加水平为100和150mg/kg的处理组T3含量比对照组分别提高了26.50%和37.61%,T4含量比对照组分别下降了34.53%和40.22%。     

细菌胞外多糖构效关系及特性的研究

近年来随着糖生物学的发展，细菌胞外多糖所表现出独特的理化特性、生物学活性越来越被人们所关注。本文对目前已研究发现的细菌胞外多糖，从结构出发对构效关系、理化性质及生物学活性进行了详细阐述。并对今后细菌胞外多糖在工业应用的前景进行了展望，以期对新型细菌胞外多糖的研究与开发提供一定的理论基础。     

培养基对细菌总数测定的影响及其改进

本实验分别用我国国家标准GB47892-94的营养琼脂,美国食品药品管理局(FDA)的标准平板(SA),及在此基础上优选出的C8、C9等四种培养基对常见的食品污染菌的菌液进行细菌总数测定的比较。结果表明:C8培养基的检测效果优于NA和SA培养基,在C8基础上添加0.15%吐温80从而优选所得的C9培养基,其检出率又比C8和SA培养基分别高出16.5%和40.8%。     

Effect of maltodextrin and emulsifiers on the viscosity of cake batter and on the quality of cakes

The effect of fat replacement by maltodextrin on cake batter viscosity and the quality of the resultant cakes was studied. The viscosity of batter was reduced significantly when fat was replaced with equal quantities of maltodextrin. Cakes prepared from this batter had low volume and firmer texture. Relatively better cakes were obtained when lower quantities of maltodextrin were used in the formulation. Viscosity of the above cake batter was relatively higher. A relationship between batter viscosity and cake volume was observed. Further improvement in cake volume could be achieved using emulsifiers. In the presence of glycerol monostearate little improvement in cake batter was observed, but the resultant cake volume was improved. However, sodium steroyl lactylate, which improved the batter viscosity, did not improve the cake volume or texture. Copyright © 2005 Society of Chemical Industry     

The influence of diet and time on feed on carcass traits and quality

Seventy-two Simmental-sired steer calves (approximately 8 months old) were randomly assigned to one of two pre-finishing dietary treatments (low energy or high energy). Energy intake was monitored to produce average daily gains of approximately 0·41 (low energy) or 0·68 (high energy) kg during a 6-month growth interval. At 14 months of age the steers were assigned to four finishing (time on feed) groups—0, 56, 112 or 168 days. Steers assigned to the 0-day group received their respective pre-finishing diets from 14 to 20 months of age. The other groups received a finishing diet for the final 56, 112 or 168 days of the experiment. All steers were slaughtered at 20 months. Steers backgrounded on high energy diets produced heavier (P < 0·01), fatter (P < 0·01) carcasses with higher (P < 0·01) marbling scores and quality grades and LD steaks with greater (P < 0·05) ease of fragmentation, less (P < 0·05) detectable connective tissue and higher (P < 0·05) tenderness ratings as compared to steers on low energy diets. After 112 days on feed, quality grades were similar for high energy and low energy steers; however, tenderness ratings still favored the high energy treatment. Increased time on feed was associated with higher quality grades, but only within the low energy treatment group. Additionally, tenderness of LD steaks improved with increased time on feed; howver, the greatest improvement was observed from 0 to 56 days.     

红曲米豆的培养及酶学研究

以红曲霉为菌种，以米、豆粕为原料，对其适合的培养条件进行了研究，得出最佳培养条件：米豆比例1.5：1；物料厚度5cm；初始水分含量50％；曲料pH值为4；30℃，6d。在此基础上对红曲米豆的酶学性质进行了初步研究，在该工艺条件下培养出的红曲米豆较红曲米的酸性蛋白酶活力提高近10倍，中性蛋白酶活力提高不大，碱性蛋白酶检测不出。糖化酶活力仍能达883．7。色价达180以上，基本保持不变。     

转谷氨酰胺酶对鸡肉猪肉混合肉糜的作用研究

目的研究转谷氨酰胺酶对混合肉的作用。方法混合肉加入该酶对比不加酶的肉糜的性能。结果经过实验得出最佳条件组合为保温时间1.5h,加酶量0.35%,保温温度40℃。结论转谷氨酰胺酶的添加可以改变肉的保水性。     

淫羊藿对成骨细胞和破骨细胞作用的研究进展

淫羊藿可促进成骨细胞增殖分化,抑制破骨细胞,其机制与调节多种骨相关蛋白质及其mRNA表达等有关。淫羊藿血清代谢物也可促进成骨细胞增殖分化。现参考近年文献,综述淫羊藿对成骨细胞和破骨细胞作用的研究进展,为进一步研究淫羊藿提供新的思路。建议加强淫羊藿体内作用试验及代谢物作用机制的研究。     

环境污染对食品的危害与对策研究

20世纪人类在享受产业和科技革命所带来的辉煌的同时,也体验到自然生态环境破坏所带来的巨大创伤。人与环境的关系密切,环境污染使得环境中物质组成改变,并因此而引起的食品安全性问题。本文阐述了人与环境的关系、食品污染的概念、食品污染的分类、食品污染的途径和食品污染的特点,并提出了降低食品污染的措施与对策。     

Impact of fungicides on Aspergillus carbonarius growth and ochratoxin A production on synthetic grape-like medium and on grapes

A study was undertaken to evaluate the impact of the application of several fungicide treatments used in Spanish vines on Aspergillus carbonarius growth and ochratoxin A production. Three trials were designed in order: (1) to screen 26 fungicides at the doses recommended by manufacturers on grape-like synthetic medium at 20 and 30°C; (2) to find out the minimum inhibitory concentration of each fungicide for A. carbonarius growth on synthetic medium; and (3) to investigate the effect of several fungicides on A. carbonarius-inoculated grapes. In synthetic medium nine fungicides significantly reduced A. carbonarius growth rate. Meanwhile, 13 fungicides completely inhibited its growth. In general, growth was faster at 30°C than at 20°C, contrary to ochratoxin A production. Fungicides that stopped fungal growth also inhibited ochratoxin A production, but not all the fungicides that reduced growth reduced the ochratoxin A synthesis. In general, fungicides that contained copper or strobilurins reduced both growth and ochratoxin A production, contrary to sulphur fungicides. At the optimum temperature for A. carbonarius growth of 30°C, higher amounts of fungicide were needed to prevent fungal growth than at 20°C. Among the fungicides that inhibited A. carbonarius growth on synthetic medium at the initial doses, cyprodinil seemed to be the active ingredient more effective at stopping fungal growth when testing reduced doses. The fungicide effect on grapes was similar to that on synthetic medium. Both infection and ochratoxin A production were reduced when using cyprodinil (37.5%) plus fludioxonil (25%) and azoxystrobin (25%). Penconazole (10%) also showed a clear reduction in ochratoxin A production at both temperatures, although infection was only reduced at 20°C. Ochratoxin A reduction was strain and temperature-dependent. In general, fenhexamid (50%), mancozeb (80%) and copper hydroxide (80%) plus copper (50%) enhanced infection and ochratoxin A production.     

摩尔比对脲醛树脂胶和刨花板性能影响的研究

本文探讨了脲醛树脂胶中甲醛与尿素摩尔比(F/U)对胶粘剂和刨花板性能的影响,从而优选出生产E1级刨花板所用的胶粘剂。     

右旋龙脑和肉桂醛抑制游离态和生物被膜态食源致病菌的研究

目的:以天然产物右旋龙脑和肉桂醛为研究对象,研究其抑制游离态和生物被膜态单核增生李斯特菌和鼠伤寒沙门氏菌的特征。方法:在采用微量肉汤稀释法研究右旋龙脑和肉桂醛单独对游离态单核增生李斯特菌、鼠伤寒沙门氏菌及其混合菌的最低抑菌浓度(MIPC)的前提下,分析两种天然产物共同作用下对游离态致病菌的最低抑菌浓度以及对生物被膜态致病菌的最低抑菌浓度(MIBC)。结果:右旋龙脑对游离态单核增生李斯特菌的MIPC为0.56 mg/mL,对游离态鼠伤寒沙门氏菌的MIPC为0.58 mg/mL,对混合菌的MIPC为0.60 mg/mL;添加肉桂醛时的3种培养状态下MIPC均为0.40μL/mL;在右旋龙脑和肉桂醛共同作用下(即0.50 mg/mL右旋龙脑和0.40μL/mL肉桂醛)对游离态菌体均可完全抑制,而2.50 mg/mL右旋龙脑和2.00μL/mL肉桂醛共同作用下可以完全抑制生物被膜态的菌体。结论:两种天然产物对生物被膜态菌体的最低抑菌浓度远远大于游离态菌体,右旋龙脑和肉桂醛在抑制游离态菌体和生物被膜态菌体生长方面具有协同作用。     

基于儿童生理、心理的童装品牌调查研究

从儿童生理、心理发展角度论述了各年龄阶段儿童所特有的心理特征，并结合我国目前童装市场现状及消费特征提出了童装品牌发展的相关策略。