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为探究配体维生素B3(C6H5NO2)、8-羟基喹啉(C9H7NO)及其稀土配合物[RE(C6H4NO2)2(C9H6NO)].2H2O(RE=La、Nd、Sm)对红酵母生物活性的影响,本实验采用平板培养皿法和抑菌圈法测定了上述三元配合物及其配体对野生红酵母和实验红酵母生长活性的影响通过比较分析抑菌圈直径的大小,我们发现8-羟基喹啉(C9H7NO)对红酵母抑制作用较强,而维生素B3没有抑制作用,与稀土(RE=La、Nd、Sm)形成三元配合物后,Sm的三元配合物抑菌能力得到了加强,而Nd和La的三元配合物抑菌能力减弱初步推测Sm配合物可应用于红酵母危害的防治 相似文献
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BP人工神经网络-光度法同时测定VB1、VB2、VB6和VPP 总被引：1，自引：0，他引：1
用BP人工神经网络解析了VB1、VB2、VB6和VPP的紫外吸收光谱,提出同时测定这四种维生素的计算分析方法,并对复合维生素片中的VB1、VB2、VB6和VPP进行了同时测定,VB1、VB2、VB6和VPP平均相对误差分别为1.45%,1.57%,4.08%和1.87%.使用了改进的BP算法,避免了神经网络学习过程中可能产生的麻痹现象;提出了目标向量的简单变换方法. 相似文献
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现象和解释:词汇重现率及其他 总被引：1，自引：0，他引：1
刘颂浩 《暨南大学华文学院学报》2006,(1):1-8
对外汉语教材编写中的词汇重现率问题最近得到了关注,研究者也发现了一些非常有价值的数据。但是,在对这些数据进行解释并据此对教材进行评价时,却出现了一些非常轻率的情况。本文对此进行了讨论。文章指出,对外汉语教学研究在方法论上必须提高“假设意识”。 相似文献
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In this opening commentary, we highlight the development of the teaching and learning of Chinese as a second or foreign language (CSL/CFL), which has attracted much attention from researchers, language educators, and other stakeholders worldwide. To contribute to this ongoing examination and discussion, this special issue documents the collective efforts of scholars in different educational contexts to review six critical issues in teaching and learning CSL/CFL: learning and instruction of reading Chinese as an additional language, Chinese character teaching and learning, learner identity in CSL/CFL education, teaching and learning Chinese through immersion, technology assisted CSL/CFL teaching and learning, and mobile assisted learning CFL. We contend that all efforts to address these critical issues require constant examination to facilitate further development in CSL/CFL education around the world. 相似文献
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Yu Ka Wong 《Reading and writing》2018,31(4):945-964
This study explored the concurrent and longitudinal relationships between reading and writing in young Chinese-as-a-second-language (CSL) learners’ sentence writing, using structural equation modeling. The participants comprised 126 Hong Kong senior primary ethnic minority students, whose literacy skills were assessed at two time points over the course of a year. In grade 5 (Time-1), they were assessed with Chinese character reading and reading comprehension measures to evaluate their reading ability. In grade 6 (Time-2), their sentence reading, sentence writing, and literacy component skills of Chinese character writing fluency and written syntactic skills were assessed. The results demonstrated that students’ reading and writing performances were substantially related both concurrently and longitudinally. Furthermore, (1) at Time-2, the component skills accounted for substantial portions of variance in sentence reading and writing skills, along with the relationship between them, while (2) Time-1 reading ability predicted Time-2 component skills and, through the mediation thereof, indirectly predicted sentence writing. Thus, in light of the linguistic characteristics of the Chinese language, literacy component skills are crucial component processes that connect reading and writing in CSL learners’ sentence writing. 相似文献
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To compare mid-infrared(MIR)and near-infrared(NIR)spectroscopies for the determination of the fat and protein contents in milk,the same sample sets with varying concentrations of fat and protein were measured in the MIR range of 3 200-700 cm-1 and NIR range of 9 000-4 000 cm-1.The spectral features in the two regions were analyzed.The MIR spectra of milk were characteristic due to the MIR inherent molecular specificity,whereas the NIR spectra were relatively characterless due to the NIR low selectivity.Partial least squares(PLS)regression models for fat and protein were developed by using both MIR and NIR spectra.MIR data with no pretreatment gave better results than NIR data.The square correlation coefficient(R2)and the root mean square error of prediction(RMSEP)were 0.98 and 0.10 g/dL for fat and 0.97 and 0.11 g/dL for protein.With NIR techniques,satisfactory results were not obtained with raw data.However,NIR data after pretreatment gave similarly good results to the ones using MIR method.This paper indicates that either of the MIR and NIR spectral methods is reliable for the determination of the fat and protein contents. 相似文献
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Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9-25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9-25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation withA. mediterranei XC 9-25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25％ of saturation in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day batch fermentation.By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentaion in the 15 L fermentor reached 18.67 g/L, which was 86.65％ higher than that of batch fermentation. Based on the scale-up principle of constantly aerated agitation power per unit volume, the scale-up ofrifamycin B fed-batch fermentation with continuous feed from a 15 L fermentor to a 7 m3 fermentor and further to a 60 m3 fermentor was realized successfully. The potency of rifamycin B fermentation in the 7 m3 fermentor and in the 60 m3 fermentor reached 17.25 g/L and 19.11 g/L, respectively. 相似文献
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Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9-25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9-25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation with A mediterranei XC 9-25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25% of saturation in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day batch fermentation. By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentaion in the 15 L fermentor reached 18.67 g/L, which was 86.65% higher than that of batch fermentation. Based on the scale-up principle of constantly aerated agitation power per unit volume, the scale-up of rifamycin B fed-batch fermentation with continuous feed from a 15 L fermentor to a 7 m3 fermentor and further to 相似文献
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自然手语与规约手语之研究 总被引：1，自引：3，他引：1
目前中国大多数聋校是以手语为主要教学语言。本文从手语的基本特点入手 ,把手语分为自然手语和规约手语并具体分析了两者的特点 ,进而就如何在课堂教学中运用好自然手语和规约手语 ,以提高课堂教学效率 ,促进聋生语言能力的发展以及以建立聋人手语语料厍。 相似文献
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Xia-ping Fu Jian-ping Li Ying Zhou Yi-bin Ying Li-juan Xie Xiao-ying Niu Zhan-ke Yan Hai-yan Yu 《Journal of Zhejiang University. Science. B》2009,10(2):120-125
The near infrared (NIR) spectroscopy technique has been applied in many fields because of its advantages of simple preparation,fast response,and non-destructiveness.We investigated the potential of NIR spectroscopy in diffuse reflectance mode for determining the soluble solid content (SSC) and acidity (pH) of intact loquats.Two cultivars of loquats (Dahongpao and Jiajiaozhong) harvested from two orchards (Tangxi and Chun'an,Zhejiang,China) were used for the measurement of NIR spectra between 800 and 2500 nm.A total of 400 loquats (100 samples of each cultivar from each orchard) were used in this study.Relationships between NIR spectra and SSC and acidity of ioquats were evaluated using partial least square (PLS) method.Spectra preprocessing options included the first and second derivatives,multiple scatter correction (MSC),and the standard normal variate (SNV).Three separate spectral windows identified as full NIR (800-2500 nm),short NIR (800～1100 nm),and long NIR (1100～2500 nm) were studied in factorial combination with the preprocessing options.The models gave relatively good predictions of the SSC of loquats,with root mean square error of prediction (RMSEP) values of 1.21,1.00,0.965,and 1.16 °Brix for Tangxi-Dahongpao,Tangxi-Jiajiaozhong,Chun'an-Dahongpao,and Chun'an-Jiajiaozhong,respectively.The acidity prediction was not satisfactory,with the RMSEP of 0.382,0.194,0.388,and 0.361 for the above four loquats,respectively.The results indicate that NIR diffuse reflectance spectroscopy can be used to predict the SSC and acidity of loquat fruit. 相似文献
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CSL （Chinese as a second language） learning is an emergency task in Taiwan, especially when more and more new immigrants joined in Taiwan. However, there are just a few new immigrants who can finish all language courses. For this reason, this research intends to provide a training system to assist new immigrants observing and learning the phrase structure. In this paper, the researchers design a system which can help new immigrants to form Chinese sentences by applying colligation and collocation technology. 相似文献
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新加坡基础华文教学模式特点分析 总被引：2，自引：0，他引：2
近年来,随着国外把汉语作为第二语文教学的不断发展,对其教学模式的研究也日益深入。新加坡是国外将汉语作为第二语文教学的少数国家之一,教学模式具有一定的代表性。其以学为中心的综合教学法的实施,量身定制的单元教学模式,都值得我们研究关注。 相似文献
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Endometrial stromal tumors(ESTs) include endometrial stromal nodule(ESN), low-grade endometrial stromal sarcoma(LG-ESS), high-grade endometrial stromal sarcoma(HG-ESS), and undifferentiated uterine sarcoma(UUS). Since these are rare tumor types, there is an unmet clinical need for the systematic therapy of advanced LG-ESS or HG-ESS. Cytogenetic and molecular advances in ESTs have shown that multiple recurrent gene fusions are present in a large proportion of LG-ESSs, and HG-ESSs are identified by the tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein epsilon(YWHAE)-family with sequence similarity 22(FAM22) fusion. Recently, a group of ESSs harboring both zinc finger CCCH domain-containing protein7 B(ZC3H7B)-B-cell lymphoma 6 corepressor(BCOR) fusion and internal tandem duplication(ITD) of the BCOR gene have been provisionally classified as HG-ESSs. In this review, we firstly describe current knowledge about the molecular characteristics of recurrent aberrant proteins and their roles in the tumorigenesis of LG-ESSs and HG-ESSs. Next, we summarize the possibly shared signal pathways in the tumorigenesis of LG-ESSs and HG-ESSs, and list potentially actionable targets. Finally, based on the above discussion, we propose a few promising therapeutic strategies for LG-ESSs and HG-ESSs with recurrent gene alterations. 相似文献
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Background
Using a 1-year longitudinal design, we evaluated the effectiveness of an intervention programme to improve reading attainments among Chinese-as-a-second-language (CSL) learners. Using the simple view of reading as a theoretical framework, the intervention focused on students' orthographic knowledge, word reading and listening comprehension to facilitate reading comprehension.Method
A total of 186 Grade 4 CSL students (mean age = 9.22, SD = 0.56) participated in the study and were grouped into the treatment (N = 96) and control (N = 90) groups. A range of Chinese language and literacy skills were assessed before and after the intervention.Results
The path analysis showed that the intervention significantly affected orthographic knowledge, word reading and listening comprehension directly and reading comprehension indirectly through the three componential skills after controlling for nonverbal reasoning, vocabulary and autoregressors.Conclusions
The findings suggest that orthographic knowledge, word reading and listening comprehension may be promising targets for instructing young CSL learners. 相似文献18.
利用VB6.0中的MMcontrol控件可以轻松地设计一个MP3播放器。在介绍MP3播放器功能和特点的基础上,对利用VB6设计MP3过程中涉及的歌曲信息存放、播放及音量控制等技术细节进行探讨。 相似文献
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Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9–25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9–25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation
with A. mediterranei XC 9–25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25% of saturation
in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day
batch fermentation. By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentation
in the 15 L fermentor reached 18.67 g/L, which was 86.65% higher than that of batch fermentation. Based on the scale-up principle
of constantly aerated agitation power per unit volume, the scale-up of rifamycin B fed-batch fermentation with continuous
feed from a 15 L fermentor to a 7 m3 fermentor and further to a 60 m3 fermentor was realized successfully. The potency of rifamycin B fermentation in the 7 m3 fermentor and in the 60 m3 fermentor reached 17.25 g/L and 19.11 g/L, respectively. 相似文献
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The use of near infrared (NIR) spectroscopy was proved to be a useful tool for quality analysis of fruits. A bifurcated fiber type NIR spectrometer, with a detection range of 800～2500 nm by lnGaAs detector, was used to evaluate the firmness of peaches. Anisotropy of NIR spectra and firmness of peaches in relation to detecting positions of different parts (including three latitudes and three longitudes) were investigated. Both spectra absorbency and firmness of peach were influenced by longitudes (i,ii, iii) and latitudes (A, B, C). For modeling, two thirds of the samples were used as the calibration set and the remaining one third were used as the validation or prediction set. Partial least square regression (PLSR) models for different longitude and latitude spectra and for the whole fruit show that collecting several NIR spectra from different longitudes and latitudes of a fruit for NIR calibration modeling can improve the modeling performance. In addition, proper spectra pretreatments like scattering correction or derivative also can enhance the modeling performance. The best results obtained in this study were from the holistic model with multiplicative scattering correction (MSC) pretreatment, with correlation coefficient of cross-validation rcv=0.864, root mean square error of cross-validation RMSECV=6.71 N, correlation coefficient of calibration r=0.948, root mean square error of cali-bration RMSEC=4.21 N and root mean square error of prediction RMSEP=5.42 N. The results of this study are useful for further research and application that when applying NIR spectroscopy for objectives with anisotropic differences, spectra and quality indices are necessarily measured from several parts of each object to improve the modeling performance. 相似文献