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 共查询到18条相似文献,搜索用时 62 毫秒
1.
蜂蜜流变特性及其质量鉴定   总被引:7,自引:1,他引:7  
对紫云英蜂蜜和白砂糖溶液以及二者的混和液进行流变试验,建立了流变体模型(New-ton)。并就温度和浓度对粘度的影响进行分析,提出采用测粘度的方法鉴别紫云蜜是否掺水和掺糖。  相似文献   

2.
国产蜂蜜流变特性研究(英)   总被引:1,自引:0,他引:1  
采用流变学方法对国产蜂蜜流变特性进行了研究。流变试验数据分析表明国产蜂蜜流变模型为Newton体,而非过去所认为的Bingham体。影响国产蜂蜜粘度的诸因素中,水分的影响最为显著。建立了国产蜂蜜w-t-η图,以充分描述其水分、温度与粘度之间的各种关系  相似文献   

3.
作者用NXS—11型旋转粘度计对八种南京市售蜂蜜进行测定,并对试验数据进行回归分析,建立了这八种蜂蜜的通用流变模型——Bingham模型。  相似文献   

4.
蜂蜜是一种触变物质。作者对八种南京市售蜂蜜在扰动条件下进行触变试验,发现其触变特性曲线均可拟合为可逆直线,几乎没有滞后圈。 又在持续匀速扰动情况下试验,八种蜂蜜的各条η—t曲线均呈线性关系,且斜率极小。即随着扰动时间t增长,粘度η降低极少。 试验证明这些蜂蜜触变性极不显著。这与《第2报》试验所知:这八种蜂蜜的表观粘度都较低,前后试验结论是一致的。  相似文献   

5.
鱼糜流变特性的研究   总被引:4,自引:0,他引:4  
研究了三种鱼糜(鲢鱼、鲤鱼、草鱼)的流变特性,建立了流变模型,提出了鱼糜表观粘度随掺水量变化而变化的关系方程,并分析了引起这种变化的原因  相似文献   

6.
作者根据实验,发现八种南京市售蜂蜜的表观粘度η′(pa·s)与温度T(℃)之间存在下列关系: η′=Be-AT 式中A和B为系数,由实验决定。 进一步分析表明上式可简化为 η′=Be-0.079T 式中0.079为系数A的平均值。 测得一种蜂蜜在某一室温下的表观粘度后,即可按上式算出这种蜂蜜在规定温度下的表观粘度。  相似文献   

7.
果品静载流变特性的研究进展   总被引:4,自引:3,他引:4  
本文通过对国内外各类果品的静载压缩流变特性研究现状的分析,指出了在果品的静载流变学研究领域内存在的主要问题,提出了今后果品流变学研究中需要加强和进一步研究的内容:1)加强对采后各阶段受压时果品的微观组织结构、生理生化过程的变化以及储运环境温度等因素与流变损伤效应的交叉性影响的研究; 2)加强对实际储运中较多出现的多果接触、受压问题的系统性研究;3)重视研究储运受压后流变损伤的发展与果品储藏品质关系的研究;4)根据国内外生产实际,应加强特色果品的流变学研究,像西瓜、甜瓜等,既具有较高的营养价值和经济价值,又在世界范围内广泛种植。同时,提出了以果品本身的粘弹性为依据,在ADAMS软件平台上利用计算机虚拟样机技术建立流变学模型并获得相应参数的新方法。  相似文献   

8.
在自制试验型挤压机和狭缝式流变仪上测定了糯米、粳米、玉米等谷物粉料的在线挤压流变特性,求得它们在中、低含水量情况下的本构方程,表明它们均为符合幂律流的假塑性流体。  相似文献   

9.
鱼糜微结构与其流变特性相关性的研究   总被引:1,自引:1,他引:1  
鱼糜的流变特性与其微结构密切相关,而对微结构与其流变特性参数间的定量描述却很少有人探讨。文章用偏最小二乘法建立了鱼糜微结构与其流变特性之间相互关系的定量描述,检验结果表明该关系方程是合理的。  相似文献   

10.
鱼糜在挤压过程中流变特性的初探   总被引:6,自引:1,他引:6       下载免费PDF全文
文章研究了鱼糜在挤压过程中的流变特性,建立了在不同压力下的流变模型,并分析了鱼糜表观粘度随压力而变化的原因  相似文献   

11.
采用流变学方法对国产蜂蜜流变特性进行了研究。流变试验数据分析表明国产蜂蜜流变模型为Newton体,而非过去所认为的Bingham体。影响国产蜂蜜粘度的诸因素中,水分的影响最为显著。建立了国产蜂蜜w-t-η图,以充分描述其水分、温度与粘度之间的各种关系  相似文献   

12.
Holocene soil chronofunctions,Southern Alps,New Zealand   总被引:1,自引:0,他引:1  
Field and laboratory data for two soil chronosequences from the high country of the South Island of New Zealand suggest rapid soil formation rates. The areas studied are the Ben Ohau Range and the Mt. Cook area, where mean annual precipitation is about 1 and 4 m, respectively. Most soil ages are estimated from the thicknesses of rock weathering rinds. Soil chronofunctions are derived for indices that depict field profile and color development, and a modified index of profile anisotropy for laboratory data. Out of a possible 21 chronofunctions, 16 are statistically significant (at the 0.05 level) and 8 are from each area. Most (13) of the chronofunctions best fit a power model, and the remaining ones are split between linear (2) and exponential (1) models. Although problems exist in the purity of the chronosequences because other soil-forming factors are not constant, duration of pedogenesis seems to be the most significant factor in explaining the trends. Despite the large differences in mean annual precipitation between the two areas, many of the derived curves for property vs. time are quite similar.  相似文献   

13.
M.L. Leamy 《Geoderma》1975,13(1):53-60
Field and laboratory methods used for the identification of paleosols in New Zealand are discussed, and examples are given of their application to both buried and relict paleosols. Field methods include a pedomorphic index based on the quantitative assessment of four or more selected diagnostic properties for each horizon, which is useful under certain conditions to express the relative degree of development of several profiles.The significance of paleosol identification is only fully appreciated when the paleosol is defined stratigraphically and interpreted in terms of time and environment. The basis for defining soil-stratigraphic units in parts of New Zealand is outlined.  相似文献   

14.
OBJECTIVES: To explore how time spent watching television (TV) is associated with the dietary behaviours of New Zealand children and young adolescents. DESIGN: Secondary data analysis of a nationally representative, cross-sectional survey. SETTING: In homes or schools of New Zealand school students. PARTICIPANTS: In total, 3275 children aged 5 to 14 years. RESULTS: The odds of being overweight or obese increased with duration of TV viewing for children and adolescents when controlling for age, sex, ethnicity, socio-economic status and physical activity. Children and adolescents who watched the most TV were significantly more likely to be higher consumers of foods most commonly advertised on TV: soft drinks and fruit drinks, some sweets and snacks, and some fast foods. Both children and adolescents watching two or more hours of TV a day were more than twice as likely to drink soft drinks five times a week or more (P = 0.03 and P = 0.04, respectively), eat hamburgers at least once a week (both P = 0.02), and eat French fries at least once a week (both P < 0.01). CONCLUSIONS: These findings suggest that longer duration of TV watching (thus, more frequent exposure to advertising) influences the frequency of consumption of soft drinks, some sweets and snacks, and some fast foods among children and young adolescents. Efforts to curtail the amount of time children spend watching TV may result in better dietary habits and weight control for children and adolescents. Future studies examining the impact of advertising on children's diets through interventions and international comparisons of legislation would provide more definitive evidence of the role of advertising in child and adolescent obesity.  相似文献   

15.
Substrates associated with two historic gold mining sites in north Westland, New Zealand, have locally very high arsenic concentrations (commonly 10–40 wt% As). The substrates consist of iron oxyhydroxide precipitates, and processing mill residues. Waters associated with some of these substrates have high dissolved arsenic (commonly 10–50 mg/L As). Natural revegetation of these very high arsenic sites has occurred over the past 50 years, although some areas of substrate remain bare. Revegetating species include native and adventive shrubs, adventive grasses, rushes, and mosses, and native ferns. Revegetation by higher plants follows initial colonization by mosses, and some shrubs are growing directly in high-arsenic substrate. Shrubs, especially manuka (Leptospermum scoparium), gorse (Ulex europaeus), tree fuchsia (Fuchsia excorticata) and broadleaf (Griselinia littoralis) largely exclude arsenic from their shoots (<?10 mg/kg dry weight) irrespective of the As content of the substrate. Likewise, most grasses, and reeds (Juncus spp.), have only modest As contents (typically <?100 mg/kg dry weight). However, mosses growing on high-arsenic substrates have strongly elevated arsenic contents (>?0.2% dry weight). In particular, the moss Pohlia wahlenbergii acts as a hyperaccumulator, with up to 3% (dry weight) As. Antimony (Sb) contents of all plants are about one thousandth of that of arsenic, reflecting the As/Sb ratio of the substrates. Plant establishment in the high-As substrates may be locally limited by low nutrient status, rather than arsenic toxicity. The shrubs, grasses, and reeds identified in this study are arsenic tolerant and largely exclude arsenic from their shoots so that revegetation with these species, can help to isolate the high-arsenic substrates from the surface environment. These species could be used as phytostabilisation agents on high-arsenic sites that are remote from human habitation. In contrast, the mosses, despite their high arsenic tolerance, are a less desirable component of revegetation of high-arsenic substrates because they actively transfer arsenic from the substrate to the biosphere.  相似文献   

16.
Concentrated solutions of copper (Cu2+), dichromate (Cr2O2? 7) and aresenate (AsO4 3?) ions (CCA solutions) are used extensively in the New Zealand timber preservation industry. These ions are therefore, potential soil pollutants at timber treatment sites. Sorption of these three ions was examined by the surface and sub-surface horizons of two free-draining New Zealand soils over a range of soil solution pH values. Copper sorption by both soils increased substantially with increasing pH and was greater in the surface compared with the sub-surface horizons. Less dichromate was sorbed than the other two ions and wa similar in both surface and sub-surface horizons for each soil. Dichromate sorption increased with decreasing pH. Arsenate sorption from solutions containing all three ions was not greatly different to influenced by changes in soil solution pH. Arsenate sorption was generally greater in the sub-surface horizons of both soils. Sorption from solutions containing all three ions was not greatly different to sorption from solutions containing the single metal ions. Sorption behaviour for each ion is related to its chemistry and the soil chemical properties of each horizon. Results suggest that in the event of soil contamination by CCA solution, the immediate leaching potential of the initial ions species present would increase in the following order: Cu2+ < HAsI 4 ? ? Cr2O 7 2? .  相似文献   

17.
《CATENA》2005,59(2):147-171
Contemporary rates of dust deposition monitored along a 300-km section of the superhumid West Coast of New Zealand's South Island are presented. In this setting, dust is entrained primarily from the dry channels of braided glaciofluvial rivers that drain the western slopes of the Southern Alps. Measured dust deposition ranged between 0.21 and 118.9 kg−1 ha−1 month−1, which is similar to dust deposition rates monitored in arid and semiarid environments. However, these are not considered to be sufficient for present day loess genesis. Dust deposition was highest in summer because of the greater frequency of favourable dust transporting winds, and the effect of rainfall was secondary. Dust transportation occurred mainly during the passage of nonprecipitating cold fronts or postfrontal southwesterlies. Transportation also occurred during prefrontal conditions, and in winter föhn southeasterlies were the predominant dust transporting winds to affect the West Coast.  相似文献   

18.
Soil erosion assumes a different form in Australia and New Zealand. Sheet, rill and gully erosion are common in eastern Australia and wind erosion in the dry cropland areas. In New Zealand, mass movement dominates the erosion landscape but other kinds, including wind erosion, do occur. It is unclear how much of the mass movement is a natural phenomenon and how much is human-induced. In either case, it causes long-term reductions in soil productivity. A landmark analysis of the soil productivity loss due to land degradation was conducted by the Australian state of New South Wales. Water erosion was a greater problem than wind erosion, but soil structure deterioration was more costly than either kind of erosion.  相似文献   

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