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1.
J.G. CHUNG J.H. LEE C.C. HO J.M. LAI Y.C. CHOU H.H. TENG C.F. HUNG S.C. HUANG 《Journal of Food Biochemistry》1996,20(4):481-490
The N-acetyltransferase activity was determined in 58 common fruits and vegetables. The assay was based on acetylation of 2-aminofluorene or p-amino-benzoic acid, followed by high pressure liquid chromatographic analysis of products and remaining nonacetylated substrate. The highest specific activities were observed in Balsam pear which contained 17.37 ± 1.45 N-acetyl aminofluorene nmole/min/mg protein and 46.27 ± 6.87 N-acetyl p-aminobenzoic acid nmole/min/mg protein. N-acetyltransferase activities within the remaining 57 foodstuffs analyzed ranged from none detected to 3.39 ± 0.72 N-acetyl aminofluorene nmole/min/mg protein and none detected to 32.45 ± 6.55 N-acetyl p-aminobenzoic acid nmole/min/mg protein. This is the first demonstration of acetyl CoA: arylamine N-acetyltransferase activity in common foodstuffs. 相似文献
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Grinding, pH adjustment, heat treatment and centrifugation were studied to recover solids from ground cod frames and to apply ultrafiltration (UF) to the resulting aqueous phase. Early heat treatment (90°C/20 min) dissolved collagen into aqueous phase resulting in a very low UF flux. A pH adjustment to 4.5 after grinding (~0.32 cm die), with no heat resulted in efficient separation after centrifuging. UF of the aqueous phase showed an increase in initial flux (23 L/hr m2). However, when the same aqueous material was heated and then centrifuged (1–2% solids removed), UF flux was further increased to 46 L/hr m2and this process gave highest solids recovery (90%). 相似文献
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测定了庚烯-(3)的蒸气压。用Gillespie型平衡器测定了甲苯—庚烯-(3)、正庚烷—庚烯-(3)二元系及甲苯—正庚烷—庚烯-(3)三元系统的平衡数据,并分别用Spinner及White方法验证了这些数据,计算结果与实验结果是符合的。三元系统气液平衡的数据不论在工程中或是实验工作上都很重要,过去对三元系统气液平衡的研究虽然有一些,但对甲苯—正庚烷—庚烯-(3)三元系统气液平衡至今在文献上尚未有记载。 由于庚烯-(3)的蒸气压数据不见于文献,我们测定了它的蒸气压数据。正庚烷—甲苯二元系统前人已有许多结果发表,我们进行了一些校核,结果与文献记载符合。甲苯—庚烯-(3)二元系统文献上没有,我们倣效了并用Spinner方法及White方法整理。至于正庚烷—庚烯-(3)二元系统,因为此两组分的性质(如沸点、n_D~(20)等)极其接近,分析误差较大,我们将其当作理想溶液处理,误差当在允许误差以内。 三元系统的分析较为繁难,误差也较大,故希望从理论和实验材料找出其规律性,以校核实验数据和推算未知三元系统。本工作利用三个二元系统的数据,用Spinner以及White的方法推算三元系统的气液平衡,与实验数据相比较,是相互符合的。 相似文献
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稀疏表示因其所具有的鲁棒性,在模式分类领域逐渐得到关注.研究了一种基于稀疏保留模型的新颖领域适应学习方法,并提出一种鲁棒的稀疏标签传播领域适应学习(sparse label propagation domain adaptation learning,简称SLPDAL)算法.SLPDAL通过将目标领域数据进行稀疏重构,以实现源领域数据标签向目标领域平滑传播.具体来讲,SLPDAL算法分为3步:首先,基于领域间数据分布均值差最小化准则寻求一个优化的核空间,并将领域数据嵌入到该核空间;然后,在该嵌入核空间,基于l1-范最小化准则计算各领域数据的核稀疏重构系数;最后,通过保留领域数据间核稀疏重构系数约束,实现源领域数据标签向目标领域的传播.最后,将SLPDAL算法推广到多核学习框架,提出一个SLPDAL多核学习模型.在鲁棒人脸识别、视频概念检测和文本分类等领域适应学习任务上进行比较实验,所提出的方法取得了优于或可比较的学习性能. 相似文献
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An analogue method(AM) is a nonparametric approach that has been applied to predict the future states of a dynamic system by following the evolution of the analogues in the historical archive. In this study, we proposed a hidden Markov model(HMM)framework for a modified analogue forecasting(MAF) approach for meteorological droughts in Korea. The unobservable(hidden) state process in the framework aims to model the underlying drought state, while the observation process was formed from the time series of the standardized precipitation index(SPI) as a drought index. Within the framework, the likelihood estimator was used as the measure of similarity between past SPI analogues and current data. The MAF approach was conducted on the selected analogues to make forecasts at lead times of one and three months. The proposed model was applied to five selected stations in Korea using the SPI data from 1973 to 2016. The forecasting performance of the proposed model was tested during the validation period(2003–2016) using several statistical criteria and it was compared to a persistence-based benchmark model. The results showed significant improvement in the forecasting capacity, and satisfactory performance for numerical SPI forecasting and categorical drought forecasting. The results also suggested that the proposed model was able to provide useful information for determining future drought categories for early drought warning with a lead time of up to three months. 相似文献
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Wetting phenomena between MgO C and CaO SiO2 slags were investigated by varying carbon content.A sessile drop technique was adopted to study the wetting phenomena in conjunction with a high speed camera for the observation of intrinsic wetting phenomena.The results show that the high content of SiO2 and the presence of Al2O3 in slags enhance the diffusion of Mg2+,leading to the promotion of reactive wetting.The carbon in MgO C refractory impedes the penetration of slags by repelling the slag and slowing the diffusion of Mg2+.This accounts for the non-wetting behavior of the slag on MgO C refractory with 17% (mass fraction) carbon similar to that of graphite. 相似文献
10.
JUN-KI CHUNG SANG SU KIM DONG SIK BAE MYUNG-HO KIM TAE KWON SONG SEUNG EON MOON 《组合铁电体》2013,141(1):415-421
ABSTRACT Stress controlled epitaxial ferroelectric Ba0.5Sr0.5TiO3 (BST) films have been deposited on Gd2O3/SrTiO3 by pulsed laser deposition with oxygen background pressure of 200 mTorr at the deposition temperature of 750°C. In order to control the stress in BST films, oxygen pressures for Gd2O3 buffer layers have been varied from 0.1 to 100 mTorr, while that of BST films have been fixed at 200 mTorr. It has been found that the lattice parameters of the BST films deposited on Gd2O3 were changed. Furthermore, microwave properties of co-planar waveguide (CPW) fabricated on BST films were investigated by a HP 8510C vector network analyzer from 1–20 GHz. Large dielectric tunabilities were observed from the CPW's fabricated on BST films deposited on Gd2O3 layers deposited at low and high oxygen pressures, 0.1 and 100 mTorr, respectively. 相似文献