Kinetics of 5-Hydroxymethylfurfural Formation in Chinese Acacia Honey during Heat Treatment

Yuyu Zhang,Yi Song,Tingting Zhou,Xiaojun Liao,Xiaosong Hu,Quanhong Li 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.6

In this paper, the 5-hydroxymethylfurfural (HMF) contents of the acacia honeys after heat treatment were determined by HPLC; the kinetics of HMF formation was also investigated. The HMF content of acacia honey was 0.38±0.01mg/kg, but rapidly increased to the maximum of 18,320.07±14.29 mg/kg at 190oC and decreased to 1,180.24±6.54 mg/kg at 230oC after heating. The HMF content increased gradually in honey samples heated in 12h at the temperature of 80, 100, and 120oC. The apparent frequency constant was kf =3.91×1025/h, and the apparent activation energy was Ea=173.10 kJ/mol. The HMF content in the acacia honey was related to honey composition,heating temperature, and time, and the HMF formation could also be related to the initial honey pH.

Preparation and Aroma Analysis of Chinese Traditional Fermented Flour Paste

Yuyu Zhang,Mingquan Huang,Hongyu Tian,Baoguo Sun,Jing Wang,Quanhong Li 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.1

Volatile compounds in Chinese fermented flourpaste were extracted using simultaneous distillation andextraction (SDE) and analyzed using gas chromatographymassspectrometry (GC-MS) with DB-5 and DB-WAXcapillary columns. A total of 84 volatile compounds wereidentified, including 8 aldehydes, 19 esters, 14 acids, 17hydrocarbons, 7 heterocycles, and 19 other trace compounds. The major volatiles included furfural, 5-methyl-2-phenyl-2-hexenal, 4-ethylguaiacol, 2-phenylacetaldehyde, ethylhexadecanoate, isovaleraldehyde, palmitic acid, and 5-methylfurfural. Aroma compounds were investigated usinggas chromatography-olfactometry (GC-O) and aroma extractdilution analysis (AEDA). A total of 27 olfactory regionswere exposed and 18 aroma extracts were located. Altogether,6 aroma compounds identified using GC-O showed higherflavor dilution factors (FD≥32), including isovaleraldehyde,furfural, pentanoic acid, 2-acetylfuran, 1-octen-3-ol, and 2-phenylacetaldehyde. Compared with soybean sauce, fermentedflour paste has more esters and aldehydes, which contributeto the desired fruity, caramel, sweet, and roasted odors.

Deep dechlorination of hydrocarbon oil by reactive adsorption on TiO2-based metal oxides

Hui Niu,Yuyu Feng,Jie Ding,Wei Zhang,Chenxing Hu,Qingxiang Zhang,Chen Zhang,Cuiqing Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.7

This study reports reactive adsorptive dechlorination of hydrocarbon oil over TiO2-based metal oxides atthe temperatures of 20-150 oC. TiO2 and a series of TiO2-CeO2 were prepared by precipitation method and characterizedby N2 adsorption, XRD, FT-IR, pyridine-IR, NH3-TPD and CO2-TPD. The characterization results showed thatboth the acidity and basicity of the adsorbent had a significant impact on its dechlorination capacity. TiO2-U precipitatedby urea exhibited higher dechlorination capacity than TiO2-A precipitated by ammonia due to the higher surfacearea, more acid and base amounts of the former. Among various Ti(1x)CexO2 (x=0.1, 0.3, 0.5, 0.7, 0.9, 1) oxides,Ti0.7Ce0.3O2 and Ti0.3Ce0.7O2 bimetallic oxides showed higher dechlorination capacity than TiO2-U, and the chlorineremoval over Ti0.7Ce0.3O2 reached 82.8% after adsorption at 150 oC for 3 h. Mixing 5 wt% of alkali earth metal oxideinto Ti0.7Ce0.3O2 mechanically enhanced its dechlorination capacity, and the chlorine removal over Ti0.7Ce0.3O2-BaOreached as high as 92.1%. The chlorine removal increased with increasing the adsorption temperature. Ion chromatographyand GC-MS analysis revealed that organochlorine compound was converted into Cl and its corresponding alcoholover the adsorbent at 150 oC. Finally, the mechanism of reactive adsorption dechlorination was proposed.

Cross-domain Recommendation by Combining Feature Tags with Transfer Learning

Yuyu Yin,Xin Wang,Jilin zhang,Jian Wan 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.10

Most recommender systems based on collaborative filtering aim to provide recommendations for a user in one domain. But data sparsity is a major problem for collaborative filtering techniques. Recently, many scholars have proposed recommendation models to alleviate the sparsity problem by transferring rating matrix in other domains. But different domains have different rating scales (e.g., rating scale may be 1-5 or 1-10). Simple process for the rating scale does not reflect the real situation. The diversity of rating scales may cause the opposite effect, making the recommendation results more imprecise. In this paper, we propose a transfer model which learning the common feature tags from other domain. This model ignores the difference of rating scales between two domains, and focus on studying the feature tags. Using its own rating values to fill the missing value. We first get the different types of users (items) based on non-negative matrix tri-factorization from auxiliary domain. The process we call the user (item) clustering. Than we can get a BP neural network which can judge the type of user according to user's feature tags by studying the features of different types of users (items). And we classify the user (items) which from target domain by exploiting the trained neural network and the users’ feature tags of target domain. Use the average rating values of the same type of users (items) to fill the missing value of target domain. We perform extensive experiments to show that our proposed model outperforms the state-of-the-art CF methods for the cross-domain recommendation task.

Hierarchical Age Estimation based on Dynamic Grouping and OHRank

( Li Zhang ),( Xianmei Wang ),( Yuyu Liang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.7

This paper describes a hierarchical method for image-based age estimation that combines age group classification and age value estimation. The proposed method uses a coarse-to-fine strategy with different appearance features to describe facial shape and texture. Considering the damage to continuity between neighboring groups caused by fixed divisions during age group classification, a dynamic grouping technique is employed to allow non-fixed groups. Based on the given group, an ordinal hyperplane ranking (OHRank) model is employed to transform age estimation into a series of binary enquiry problems that can take advantage of the intrinsic correlation and ordinal information of age. A set of experiments on FG-NET are presented and the results demonstrate the validity of our solution.

A BIM Based Approach for Structural Health Monitoring of Bridges

Xiaofei Li,Yuyu Xiao,Hainan Guo,Jisong Zhang 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.1

With the development of bridges, independent condition assessment of large-scale bridges has garnered significant attention over the past few decades. Data-driven structural health monitoring (SHM) techniques offer valuable information on the existing health of the structures, maintain safety, and uninterrupted use under varied operational conditions by undertaking timely risk and hazard mitigation. Traditional approaches, however, are not enough to monitor a large amount of SHM data and conduct systematic decision making for future maintenance. In this paper, a bridge health monitoring system is developed through the combination of building information modeling (BIM) and traditional bridge health monitoring that can organize and visualize a considerable amount of sensor data and subsequent structural health information over a prolonged period. The system can identify the structural damage by evaluating the data from sensors using Wigner-Ville distribution (WVD) in bilinear time-frequency analysis. A BIM-enabled platform is utilized to develop the proposed visualization tool for a long-span bridge and enable automated sensor data inventory into the BIM environment. The system has been tested for its robustness and functionality against the development requirements, and the results showed promising potential to support more effective bridge information management.

Thermal creep behavior of CZ cladding under biaxial stress state

Jin, Xin,Lin, Yuyu,Zhang, Libin Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.12

Thermal creep is a key property of zircaloy cladding. CZ developed by CGN is a new zircaloy used as PWR fuel cladding. This research is devoted to investigating the thermal creep behavior of CZ and build the thermal creep model of CZ. Twenty internal pressure creep tests were conducted, and the ranges of temperature and Tresca stress were 320-430 ℃ and 70-300 MPa, respectively. Real-time creep data were analyzed by separating primary creep and steady-state creep. Based on Soderberg model and creep test data, CZ thermal creep model is derived. As a whole, the mean value and the standard deviation of P/M of CZ saturated primary creep strain are very close to these from steady-state creep rate, however, the predictive effect of primary creep is less satisfactory. Four conditions, where there exists large deviation between predicted values and test data, are 320 ℃ and 300 MPa, 350 ℃ and 190 MPa, 380 ℃ and 160 MPa, 380 ℃ and 190 MPa, respectively. As primary creep was much smaller than steady-state creep in long-time operation, the thermal creep model built can be applied to predict the thermal creep behavior of CZ cladding.

Sexual dimorphism-related gene expression analysis based on the transcriptome in Gynaephora qinghaiensis, a pest of grassland on the Qinghai-Tibet Plateau

Wang Hai-Zhen,Zhang Ru-yi,Yuyu-Li,Liu Xin 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.2

Gynaephora qinghaiensis is a pest in the alpine meadows of the Qinghai-Tibet Plateau (QTP) that seriously harms grassland vegetation. Sexual dimorphism (SD) is common in insects, but its molecular mechanism at the tran scriptome level in insects, especially in G. qinghaiensis, has not been reported. In this study, we conducted transcriptome analysis of pupae and adults of the two sexes (male and female) of G. qinghaiensis. A total of 204,557,900 clean reads assembled into 114,944 unigenes were obtained by RNA-Seq. To explore differences in the transcriptome levels of molecular characteristics related to SD between the two sexes of G. qinghaiensis, gene expression profiling was performed. A total of 88 differentially expressed unigenes related to sex determination were found in the pupae of G. qinghaiensis; of these, 74 were upregulated and 14 were downregulated in the female pupae compared to the male pupae. Forty-five unigenes related to sex determination were found in the adults of G. qinghaiensis; of these, 15 were upregulated and 30 were downregulated in the female adults compared to the male adults. This indicated some differences in the expression of genes involved in sex deter mination between male and female individuals of G. qinghaiensis. Therefore, we speculated that sex-determining genes may play an important role in the formation of sexual dimorphism in G. qinghaiensis. Our report provides a valuable genomic resource for further studies of grassland caterpillars and improves our understanding of the molecular mechanisms underlying sexual dimorphism between male and female insects.

Modeling urban building energy use: A review of modeling approaches and procedures

Li, Wenliang,Zhou, Yuyu,Cetin, Kristen,Eom, Jiyong,Wang, Yu,Chen, Gang,Zhang, Xuesong Elsevier 2017 ENERGY Vol.141 No.-

<P><B>Abstract</B></P> <P>With rapid urbanization and economic development, the world has been experiencing an unprecedented increase in energy consumption and greenhouse gas (GHG) emissions. While reducing energy consumption and GHG emissions is a common interest shared by major developed and developing countries, actions to enable these global reductions are generally implemented at the city scale. This is because baseline information from individual cities plays an important role in identifying economical options for improving building energy efficiency and reducing GHG emissions. Numerous approaches have been proposed for modeling urban building energy use in the past decades. This paper aims to provide an up-to-date review of the broad categories of energy models for urban buildings and describes the basic workflow of physics-based, bottom-up models and their applications in simulating urban-scale building energy use. Because there are significant differences across models with varied potential for application, strengths and weaknesses of the reviewed models are also presented. This is followed by a discussion of challenging issues associated with model preparation and calibration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Advances in urban buildings energy models are reviewed. </LI> <LI> Strengths and weaknesses of urban building energy models are discussed. </LI> <LI> The workflow of physics-based bottom-up models are illuminated. </LI> <LI> Challenges and future research avenues in urban buildings energy use modeling are highlighted. </LI> </UL> </P>

Analyzing the Impact of the Internet on Higher Education

Renjie Zhou,Dongchen Xia,Yuyu Yin,Jilin Zhang,Wei Zhang,Jin Feng 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.6

The Internet has gone deeply into nowadays college students’ life, and has become an important platform for students to study, entertainment, and build social relationships. In this paper, we study the patterns of how college students use the Internet, and analyze the potential impacts of Internet on the living and education of college students. We find that 95% of college students spend more than two hours online per day. Academic and career development is the top motivation for college students to use the Internet. However, high percentage of the college students is not able to control their usage of the Internet well, which leading to recognition that the Internet is a negative factor that affects their course performance. The findings are helpful for educators to guide students to use Internet in a reasonable way and to find ways to make the Internet to be conducive to high quality of higher education.