威权意识下女性命运的真实写照--评析《大地》中的阿兰形象

阿兰是赛珍珠的代表作品《大地》中旧式中国农村妇女的学形象，她忠厚朴实，坚毅勤劳，深受威权意识和封建思想道德的重重压迫。中分析了阿兰的优点和她性格中的缺陷，再现了旧中国女性难以摆脱封建威权意识深重压迫的悲惨命运。     

Sunflower Head Residue Pectin Extraction as Affected by Physical Conditions

Effects of extraction pH, temperature, and time on yield and quality of pectin from sunflower heads (Interstate cultivar) were investigated. The low-methoxyl pectin was extracted, using 0.75% sodium hexametaphosphate at pH 3, 4, and 5 and at 75, 85, and 95°for 20, 40, and 60 min, respectively. Yield, molecular mass, and firmness of jellies of the pectins were determined. Three-way statistical analysis on yield, molecular mass and gel firmness showed strong interactions among pH, temperature and time. Highest yields were obtained at pH 5, 95°for 20 min and pH 4, 85°for 40 min. Pectin extracted for 40 min at pH 3 and 4 and at 85°and 75°C, respectively, had the highest molecular mass. Gel firmness of sunflower pectin prepared at pH 5.4 was higher than that of a commercial citrus pectin.     

Physicochemical and Sensory Evaluation of 'Rocha' Pear Following Controlled Atmosphere Storage

ABSTRACT: The effects of several processing factors (storage time, time in the open air at room temperature, and overhead concentrations of O₂ and CO₂) on color, firmness, polyphenol oxidase (PPO) activity, and sensory attributes of pears (cv. Rocha) grown in 2 locations were studied using a multiple linear regression model. Backward elimination (F ≥ 0.005) was used to assess the significant factors. Extended storage time, long‐time exposure at room temperature, and high O₂ concentration played major roles on color changes assessed instrumentally and further confirmed by a sensory panel. Firmness was strongly affected by storage time and by time in the open air at room temperature. Finally, PPO activity was dependent on the growing location.     

引气剂在南水北调中线工程中的应用

引气剂在混凝土中能够引入大量微小、封闭、稳定的气泡,可改善混凝土和易性、耐久性,延长建筑物的使用寿命。引气剂的使用效果与混凝土的原材料质量、拌和工艺及环境有关,使用时应适当调整掺量,满足含气量的技术指标要求。     

引气剂在南水北调中线工程中的应用

引气剂在混凝土中能够引人大量微小、封闭、稳定的气泡,可改善混凝土和易性、耐久性,延长建筑物的使用寿命.引气剂的使用效果与混凝土的原材料质量、拌和工艺及环境有关,使用时应适当调整掺量,满足含气量的技术指标要求.     

Invited review: Genetics and modeling of milk coagulation properties

Milk coagulation properties (MCP) are conventionally measured using computerized renneting meters, mechanical or optical devices that record curd firmness over time (CF_t). The traditional MCP are rennet coagulation time (RCT, min), curd firmness (a₃₀, mm), and curd-firming time (k₂₀, min). The milk of different ruminant species varies in terms of CF_t pattern. Milk from Holstein-Friesian and some Scandinavian cattle breeds yields higher proportions of noncoagulating samples, samples with longer RCT and lower a₃₀, and samples for which k₂₀ is not estimable, than does milk from Brown Swiss, Simmental, and other local Alpine breeds. The amount, proportion, and genetic variants (especially κ-casein) of milk protein fractions strongly influence MCP and explain variable proportions of the observed differences among breeds and among individuals of the same breed. In addition, other major genes have been shown to affect MCP. Individual repeatability of MCP is high, whereas any herd effect is low; thus, the improvement of MCP should be based principally on selection. Exploitable additive genetic variation in MCP exists and has been assessed using different breeds in various countries. Several models have been formulated that either handle noncoagulating samples or not. The heritability of MCP is similar to that of other milk quality traits and is higher than the heritability of milk yield. Rennet coagulation time and a₃₀ are highly correlated, both phenotypically and genetically. This means that the use of a₃₀ data does not add valuable information to that obtainable from RCT; both traits are genetically correlated mainly with milk acidity. Moreover, a₃₀ is correlated with casein content. The major limitations of traditional MCP can be overcome by prolonging the observation period and by using a novel CF_t modeling, which uses all available information provided by computerized renneting meters and allows the estimation of RCT, the potential asymptotic curd firmness, the curd-firming rate, and the syneresis rate. Direct measurements of RCT obtained from both mechanical and optical devices show similar heritabilities and exhibit high phenotypic and genetic correlations. Moreover, mid-infrared reflectance spectroscopy can predict MCP. The heritabilities of predicted MCP are higher than those of measured MCP, and the 2 sets of values are strongly correlated. Therefore, mid-infrared reflectance spectroscopy is a reliable and cheap method whereby MCP can be improved at the population level; this is because such spectra are already routinely acquired from the milk of cows enrolled in milk recording schemes.     

太阳能聚光器薄膜的牢固度理论和制备技术

针对太阳能聚光器薄膜在制备过程中牢固度不理想这一问题，确定在薄膜的生长过程中影响薄膜牢固度的各个因素，对这些因素作了具体的分析，并在实验的基础上，给出了提高薄膜牢固度的具体措施。     

Cooking and texture properties of gluten‐free fettuccine processed from defatted flaxseed flour and rice flour

Nonconventional raw materials have been applied in gluten‐free pasta, to meet the demand of people with coeliac disease. The objective of this study was to evaluate the cooking properties and texture of pasta formulated with rice flour, defatted flaxseed flour and pregelatinised mixed flour of rice and flaxseed (80:20). For this experiment, simplex design was used. Cooking properties and texture were found within the quality limits established for this type of product. The pasta with the most desirable properties (short optimum cooking time (OCT), less solid loss (SL) and intermediate mass increase (MI)) was that one formulated with 43 g 100 g^?1 of pregelatinised flour, 47 g 100 g^?1 of rice flour and 10 g 100 g^?1 of defatted flaxseed flour. This formulation can be characterised as a food rich in dietary fibre and of high nutritional value.     

Effects of rind removal on physicochemical quality characteristics of fresh‐cut watermelon [Citrullus lanatus (Thunb) Matsum & Nakai] during cold storage

The impact of removing the rind from fresh‐cut watermelon slices was assessed on the quality of the product during storage at 4 °C for 9 days. Flesh lycopene declined from 55.4 to 47.9 mg kg^?1 f.w. and colour lightness (L*) increased from 43.2 to 45.8 after 2 days of storage. Initial heart and placental flesh firmness increased from 7.3 and 9.8 N, respectively, to 9.5 and 12.8 N after 9 days, but were unaffected by rind processing. Electrolyte leakage from placental tissue was unaffected by storage and rind. Rind presence limited juice run‐off by 47.2% and maintained mean total soluble sugar concentration in the slices at 86.0 mg mL^?1 as opposed to 76.8 mg mL^?1 in rind‐less slices. Change in the quality was most pronounced between 0 and 2 day of storage. Removing the rind accelerated senescence and off‐flavour production, while the presence of rind improved the overall storage stability of fresh‐cut watermelon slices.