共查询到20条相似文献，搜索用时 203 毫秒
1.
《农产品加工．学刊》2016,(5)
通过综述玉米胚芽蛋白的营养价值、功能特性和3种不同的提取方法 (碱溶酸沉法、酶法、反胶束萃取法),简要分析了玉米胚芽蛋白的功能特性及其影响因素,为进一步综合利用玉米胚芽蛋白提供理论参考。 相似文献
2.
基于液-液萃取机理的新型环境样品前处理方法研究进展 总被引：2，自引：0，他引：2
新型环境样品前处理技术已经逐步取代传统液-液萃取。液相微萃取、液膜萃取和逆流色谱技术均是集采样、萃取和浓缩于一体的环境友好型环境样品前处理技术。液相微萃取、液膜萃取实质上是微型化的液-液萃取;逆流色谱结合了液液萃取和分配色谱的优点,是一种新型色谱分离技术。3种技术均对环境样品中的痕量/超痕量污染物质有高效的富集、净化效果。笔者综述了液相微萃取、液膜萃取和逆流色谱技术的优缺点及在环境样品前处理中的应用。 相似文献
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天然香精是从芳香植物中用物理方法提取的有机混合物,具有独特、自然、舒适的香气和香韵,在香料工业、日化、食品等领域有广泛应用,但利用传统方法萃取易使其原有香味失真;超临界CO2流体萃取是一种新型分离技术,特别适于不稳定及热敏性天然产物的萃取,利用该技术萃取天然香精可得到高品质高价值的产品。概述了超临界CO2流体萃取技术,介绍了近几年该技术萃取植物天然香精及其与其他分离技术结合的相关研究,探讨了该技术在应用中存在的问题及其发展前景,旨在为该技术萃取天然香精的进一步应用提供参考。 相似文献
4.
介绍了连续梯度法萃取大豆浓缩蛋白的生产工艺。以脱脂豆粕为原料,以不同体积分数的乙醇水溶液为溶剂,采用连续梯度浸提法来萃取大豆浓缩蛋白,从而使蛋白质的含量提高到65%以上,且产品的气味得到明显的改善。 相似文献
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《农产品加工．学刊》2017,(12)
超临界流体萃取是一项高新技术,在化学工业、食品工业、医药工业、香料工业等产业上应用广泛。综述了超临界流体萃取技术的基本原理和技术方法、超临界CO_2技术的优势,以及超临界CO_2萃取技术在天然香料工业上对天然香料的提取应用和该项技术的发展前景。 相似文献
7.
超临界CO2流体萃取瑞香狼毒根部油脂工艺条件的优化 总被引：1，自引：1，他引：0
【研究目的】本实验采用超临界CO2萃取技术提取瑞香狼毒根部油脂,并确立其工艺条件【方法】通过单因素试验及正交试验,对CO2流量、萃取时间、萃取压力、萃取温度、分离温度、分离压力等条件进行了优化。【结论】在试验范围内,各影响因素对瑞香狼毒根部油脂得率作用的大小依次为：萃取压力＞分离压力＞萃取温度＞分离温度。超临界CO2流体萃取技术提取瑞香狼毒根部油的最佳工艺参数为：CO2流量21L/h,萃取时间为100min,萃取压力30MPa,萃取温度46°C,分离温度45°C、分离压力5.5Mpa。在此最佳工艺条件下,瑞香狼毒根部油脂萃取率达到3.57%。 相似文献
8.
顶空固相微萃取在猕猴桃酒香气成分测定中的应用 总被引：9，自引：1，他引：9
利用固相微萃取和气相色谱、质谱联用技术,对猕猴桃果酒中的香气成分进行分析,研究了萃取温度、萃取时间、加电解质的量对猕猴桃果酒香气物质萃取的影响,优化了提取条件,建立了快速测定猕猴桃酒中香气物质的方法。结果表明,最佳萃取温度为40℃,最佳萃取时间为40min,最佳加盐量为0.3g/mL。 相似文献
9.
超临界流体萃取技术在食品中的应用研究 总被引：5，自引：0，他引：5
超临界流体萃取(SFE)技术是一种新型的分离技术。对超临界萃取的基本原理进行了阐述,介绍了超临界萃取的特点及其在食品加工方面的应用和研究进展,并对今后的发展趋势进行了展望。 相似文献
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超声波萃取技术已广泛用于食品、药物、工业原材料等样品中有机或无机组分的分离和提取,分析超声波萃取技术在农业科学研究领域中的应用,以促进超声波萃取在分离提取技术领域的发挥。 相似文献
11.
小麦植株器官光合作用与籽粒产量的研究 总被引：7，自引：0，他引：7
采用剪去叶片和芒及穗部、茎秆和叶鞘遮光处理,植株各器官对单穗粒重的影响依次为穗→芒和叶片→茎秆和叶鞘,不同叶序的叶片对单穗粒重的影响为倒2叶→旗叶→倒3叶→倒4叶。 相似文献
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A networked sharing application system for reverse engineering is proposed. It is targeted at a wide distribution of small and medium manufacturing enterprises and the technology complexity of reverse product design. Making full use of modern information 相似文献
14.
Toyoaki Anai 《Breeding Science》2012,61(5):462-467
Mutant-based reverse genetics offers a powerful way to create novel mutant alleles at a selected locus. This approach makes it possible to directly identify plants that carry a specific modified gene from the nucleotide sequence data. Soybean [Glycine max (L.) Merr.] has a highly redundant paleopolyploid genome (approx. 1.1 Gb), which was completely sequenced in 2010. Using reverse genetics to support functional genomics studies designed to predict gene function would accelerate post-genomics research in soybean. Furthermore, the novel mutant alleles created by this approach would be useful genetic resources for improving various traits in soybean. A reverse genetic screening platform in soybean has been developed that combines more than 40,000 mutant lines with a high-throughput method, Targeting Local Lesions IN Genome (TILLING). In this review, the mutant-based reverse genetic approach based on this platform is described, and the likely evolution of this approach in the near future. 相似文献
15.
The machine setting reverse method of spiral bevel gear 总被引：2，自引：0，他引：2
The profile error correction of spiral bevel gears is difficult. To solve this problem, the inspected method of spiral bevel gears tooth surface is studied in 3906 gear measuring center. The grids of tooth surface is measured by measurement software. Taking reference tooth surface as the goal, a method of machine setting reverse using approximation algorithms is proposed, and a mathematical model is build. At last, a reverse example based on grinded spiral gear is given. The result shows that the cutting machine setting of bevel gear tooth surface can be exactly calculated. 相似文献
16.
Simulating of Asymptotic Distributions of Extreme Wind Speed in ChongQing Using Short-term Wind Speed Records 总被引：1，自引：0，他引：1
In order to reduce the potential statistical error from the short sample of wind speed(the data of wind speed between 1990 and 1999 in ChongQing district),a method is introduced that simulates the asymptotic distributions of annul maximum wind speed according to the monthly maximum wind speed data.The simulated results of three extreme distributions(Gumbel,Frechet and reverse Weibull distributions) and Generalized Parato Distribution are contrasted and analysed.The reverse Weibull distribution is evaluated as the best asymptotic one for short-term wind speed records in ChongQing.And the optimal value of annul maximum wind speed is estimated. 相似文献
17.
Zheng Zhong Gao Jiarui 《保鲜与加工》1992,(1):35-41
The mechanism of heat transfer during sheet metals heating with impinging jet in a rapid heating furnace is studied with experiments and mathematical simulating methods. It is shown that the heat exchange between metals and impinging jet occurs mainly in the lower region of the hearth,most of which is carried out in the manner of convective heat transfer,and the convective portion of the total heat fluxing to metal is up to 80%. Furthermore,it is also found that the reverse heat flux from metals to the wall, which is a new heat transfer phenomenon, takes place in the late heating period, and the intenser the convective heat transfer in the furnace is, the earlier the reverse radiation occurs. 相似文献
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By using servo control shear loading system, specimens with non-coplanar rock-like intermittent joints were tested by the way of forward and reverse direct shear, rupture mechanism and shearing law for rock bridge with non-coplanar intermittent joints were studied under direct shear. The experimental studies showed that five apparent stages are presented in the process of rock bridge rupture under direct shear, which are linear elastic stage, initiation and extension of crack, fracture and transfixion of rock bridge, climbing and occlusion of shear plane and residual friction. Rock bridge presented profile fracture plane under forward direct shear. While under reverse direct shear, band form fracture plane is showed which penetrated along with the direction of forward shear, and the shear strength of initiation and peak shear strength under reverse direct shear are bigger than that under forward shear. Crack angle, normal stress and lap proportion among adjacent joint are the main factors that influence the initiation strength and peak shear strength. The FLAC 3D simulation for the process of non-coplanar intermittent joints rock bridge rupture and formation of shear rupture surface under forward and reverse direct shear was conducted. The results of numerical simulation agreed well with those of experiment. The simulation results revealed tension crack failure of non-coplanar intermittent joints rock bridge and shear yielding mechanism of fracture plane. 相似文献
19.
以辣椒属5个栽培种叶片为试材,利用Ty1-copia类逆转座子逆转录酶的保守序列设计简并引物,PCR扩增后均获得了260bp左右的目的条带。对C.annuum的扩增产物进行纯化、克隆和测序,经Mega4和DNAstar软件分析后,获得25条逆转录酶序列,核苷酸序列长度变化范围为225～272bp,这些序列存在高度的异质性,主要表现为缺失突变,同源性范围为23.1%～93.2%,核苷酸聚类分为7个组。翻译成氨基酸后,有9条序列存在1～3个不同程度的终止密码子突变,4条序列存在移框突变。将这25条逆转录酶的氨基酸序列与已发表的不同物种同一类型逆转座子的逆转酶序列进行聚类分析,表明辣椒的Ty1-copia型逆转座子与烟草、矮牵牛、马铃薯有很近的关系。 相似文献
20.
南郑春季低温及对水稻育秧的危害 总被引：5，自引：1，他引：5
分析了1966—2003年南郑春季（4—5月）低温发生情况，用＜12℃的负有效积温和最低气温划分低温对水稻的危害程度。结果表明南郑春季＜12℃的低温都发生在4月份，39%年份无危害，21%年份有轻危害，19%年份有中危害，21%年份有重危害。倒春寒发生频率为21%，集中于5月上中旬。＜12℃低温属连阴雨型的是晴冷型的2倍，倒春寒年份常伴有连阴雨型低温。分析了低温对水稻育秧的影响，4月中下旬是秧苗受＜12℃低温危害的关键时期，5月上中旬是秧苗受倒春寒危害的关键时期。针对不同类型低温，提出了不同预报服务和田间管理措施。 相似文献