Intercalation of Europium Inclusion Complex of β-Cyclodextrin into Layered Double Hydroxides Through Layer-By-Layer Assembly and Its Luminescent Properties

Wenjun Zhang,Yi Chen,Yanlin Li,Sumin Guan,Yan Chen,Qian-Qian Yang,Lu Liu,Qing-Chen Xue,Yu-Cui Guang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10

"In this work, organic–inorganic hybrid ultrathin transparent films (UTFs), produced by layer-by-layer (LBL) assembly of the europium inclusion complex of β-cyclodextrin ( β-CD) and Mg–Al layered double hydroxide (MgAl–NO3–LDHs) nanosheets, are reported. UV-visible (UV-Vis) absorption and fluorescence spectroscopy show orderly growth of the europium inclusion complex of β-CD/layered double hydroxide (EICC/LDH) films with an increasing number of deposition cycles. X-ray diffraction and scanning electron microscopy measurements indicate that the films feature periodic layered structures with uniform surface morphology. Moreover, when EICC is assembled with inorganic rigid LDH nanosheets, the lifetimes are prolonged due to the isolation effect, and the UTFs are transparent with high brightness, which indicate that these films could serve as new optical materials."

Meta-mordant Dyeing with Camellia sinensis (L.) O. Ktze var. waldensae (S.Y.Hu) Chang (Yellow-bud Tea) Extract for Wool Fabrics Treated by UV Radiation

Cheng Chen,Min Li,Chunxia Wang,Shaohai Fu,Wenjun Yan,Chuansheng Chen 한국섬유공학회 2018 Fibers and polymers Vol.19 No.6

The wool fabrics were treated by ultraviolet (UV) radiation and then dyed with Camellia sinensis (L.) O. Ktze var. waldensae (S.Y.Hu) Chang (yellow-bud tea) extract using meta-mordant dyeing method. The results indicated that the hydrophilicity of wool fabrics was improved after UV radiation treatment, which was conducive in improving color performance for the meta-mordant dyeing with yellow-bud tea extract of wool fabrics. The optimal dyeing process was that the powdered extract (5.0 % o.w.f) and the CuSO4 (2.0 % o.w.f) were added to the dyeing liquor, the pH value was adjusted to 3.5-4.0 by HCOOH, the wool fabrics treated by UV radiation for 10 min and then were dyed at a bath ratio of 1:50 under 95 oC for 70 min. By means of three-factor quadratic current rotation revolving design (TQCRRD) method, the computation results of the mathematical equations and models indicated that UV radiation was the most important factor for meta-CuSO4 dyeing with yellow-bud tea extract for wool fabrics.

Research and Application of Fiber Bragg Grating Sensor in Geological Disaster Automation Monitoring

Liu Yimin,Wang Jie,Ji Weifeng,Zhou Ce,Chen Wenjun 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

In this paper, fiber grating technology is used for accurately measure stresses, temperature and displacement. The paper introduces the basic principles of FBG technology and the wavelength demodulation method of FBG sensors, and put fiber grating technology into practical engineering projects. The paper design a optical fiber grating real-time automation monitoring system to distributed measure stress, temperature and displacement in geological disaster body, to provide effective technical supports for geological disaster prevention and mitigation.

Small-World Features of Real-World Networks

Wenjun Xiao,Meisheng Li,Guanrong Chen 한국통신학회 2017 Journal of communications and networks Vol.19 No.3

It is well known that there are a large number of complex networks that have vertex-degree distributionsin a power-law form of $ck^{-\gamma}$, where $\emph{k}$ is the degree variable and $\emph{c}$ and $\gamma$are scaling and exponent constants. Recently, we found that it is effective to reveal the underlyingmechanism of power-law formation in real-world networks by analyzing their vertex-degree sequences. We showed before that, for a scale-free network of size \emph{N}, if its vertex-degree sequence is$ k_{1}<k_{2}<{\cdots}<k_{l} $, where $\{k_{1},k_{2},{{\cdots}},k_{l}\}$ is the set of all non-equal vertex degreesin the network, and if its power exponent satisfies $\gamma>1$, then the length \emph{l} of the abovevertex-degree sequence is of order $\log N$. We underline that this conclusion is important, which proves thatthe length of the vertex-degree sequence is a fundamental characteristic of a scale-free network. In this paper,we further investigate complex networks with more general distributions and we prove that the same conclusionabout the vertex-degree sequences holds even for non-network type of complex systems. We thereby conclude thatreal-world networks typically possess small-world features. We support this conclusion by verifying a largenumber of real-world networks and systems. To that end, we discuss some potential applications of the new findingin various fields of science, engineering and society, demonstrating that the conclusion is important with manyreal applications.

Removing the Effects of Environmental Factors from Proximally Sensed Vis-Nir Spectra

Wenjun Ji,Zhou Shi,Raphael Viscarra Rossel,Songchao Chen,Qianlong Wang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Atypical triggers in trigeminal neuralgia: the role of A-delta sensory afferents in food and weather triggers

( Wenjun Koh ),( Huili Lim ),( Xuanxuan Chen ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.1

Background: Trigeminal neuralgia is a debilitating craniofacial pain syndrome that is characterized by paroxysms of intense, short-lived electric shock-like pains in the trigeminal nerve distribution. Recently, the presence of triggers has become one of the key diagnostic criteria in the 3rd edition of the International Classification of Headache Disorders. Light touch is the most common trigger, however other non-mechanical triggers, such as cold weather and certain foods, have been thought to provoke trigeminal neuralgia anecdotally. We aimed to characterize the prevalence and characteristics of these atypical triggers. Methods: We conducted a retrospective, cross-sectional study of atypical triggers in trigeminal neuralgia patients seen in a tertiary pain clinic in Singapore. Patients were recruited via clinic records, and study data were identified from physician documentation. Results: A total of 60 patients met the inclusion criteria. Weather triggers were observed in 12 patients (20%), of which five patients (8%) reported strong winds, 4 patients (7%) reported cold temperatures, and 3 patients (5%) reported cold winds as triggers. Fifteen patients (25%) had a specific food trigger, of which 10 patients (17%) reported hard or tough food, 5 patients (8%) reported hot/cold food, 4 patients (7%) reported spicy food, and 2 patients (3%) reported sweet food as triggers. Conclusions: Although trigeminal neuralgia is most commonly triggered by mechanical stimuli, atypical triggers such as cold temperatures and certain foods are seen in a significant proportion of patients. These atypical triggers may share a common pathway of sensory afferent Aδ fiber activation.

One-Step Hydrothermal Deposition of Ag-Doped g-C3N4-TiO2 Nanocomposites on Cotton Fabric Surface with Enhanced Photocatalytic Activity

Wenjun Li,Hui Zhang,Pei Chen,Jiale Yao,Xiangzhi Dong 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2

In this study, Ag-doped g-C3N4-TiO2 nanocomposite photocatalysts were deposited on the surface of cotton fabric by a simpleone-step hydrothermal method. The structure features of as-modified cotton fabric were examined by a series of characterizationtechniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction(XRD) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectroscopy (DRS) andphotoluminescence spectroscopy (PL). The experimental results showed that highly dispersed Ag nanoparticles were dopedinto g-C3N4-TiO2 nanocomposites which were evenly coated on the fabric surface. The introduction of Ag nanoparticles intog-C3N4-TiO2 composites could significantly improve the photodegradation rate of methyl orange (MO) dye under visiblelight irradiation. Importantly, the doping site of Ag nanoparticles had a significant influence on the photocatalytic activityof Ag-doped g-C3N4-TiO2 nanocomposites. Compared with the g-C3N4-TiO2 coated cotton fabric, the Ag-doped g-C3N4-TiO2 coated cotton fabric displayed excellent photocatalytic properties for the photodegradation of MO dyes because of thenarrowed band gap and the faster separation and transfer of photoinduced charge carriers. The substrate of cotton fabric hadlittle influence on the active radicals produced by the Ag-doped g-C3N4-TiO2 nanocomposites. In addition, the as-modifiedcotton fabric exhibited good reusability and stability after five recycles for the photodegradation of MO dyes.

Semi-fragile Watermarking Scheme for H.264/AVC Video Content Authentication Based on Manifold Feature

( Chen Ling ),( Obaid Ur-rehman ),( Wenjun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.12

Authentication of videos and images based on the content is becoming an important problem in information security. Unfortunately, previous studies lack the consideration of Kerckhoffs`s principle in order to achieve this (i.e., a cryptosystem should be secure even if everything about the system, except the key, is public knowledge). In this paper, a solution to the problem of finding a relationship between a frame`s index and its content is proposed based on the creative utilization of a robust manifold feature. The proposed solution is based on a novel semi-fragile watermarking scheme for H.264/AVC video content authentication. At first, the input I-frame is partitioned for feature extraction and watermark embedding. This is followed by the temporal feature extraction using the Isometric Mapping algorithm. The frame index is included in the feature to produce the temporal watermark. In order to improve security, the spatial watermark will be encrypted together with the temporal watermark. Finally, the resultant watermark is embedded into the Discrete Cosine Transform coefficients in the diagonal positions. At the receiver side, after watermark extraction and decryption, temporal tampering is detected through a mismatch between the frame index extracted from the temporal watermark and the observed frame index. Next, the feature is regenerate through temporal feature regeneration, and compared with the extracted feature. It is judged through the comparison whether the extracted temporal watermark is similar to that of the original watermarked video. Additionally, for spatial authentication, the tampered areas are located via the comparison between extracted and regenerated spatial features. Experimental results show that the proposed method is sensitive to intentional malicious attacks and modifications, whereas it is robust to legitimate manipulations, such as certain level of lossy compression, channel noise, Gaussian filtering and brightness adjustment. Through a comparison between the extracted frame index and the current frame index, the temporal tempering is identified. With the proposed scheme, a solution to the Kerckhoffs`s principle problem is specified.

Investigation on Ploidy Level and Reproductive Characteristic of Whipgrass

Chen Lingzhi,Yang Chunhua,Tang Zhisong,Huang Huijun,Zhang Wenjun 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08

26 wild accessions and 2 cultivars of whip grass (Hemarthria compress a (L. f.) R. Br.), which collected in the fields of Sichuan Agricultural University (SAU), were used to study on their ploidy level and reproductive characteristics. The results showed that there were 4 tetraploids (14.3%), H028, H029, H052, H053, chromosome numbers were 2n=4x=36, and 24 hexaploids (85.7%), 2n=6x=54. There was no significant correlation between geographical distribution and ploidy level in this research. From 2006 to 2008, hexaploids set few seeds, but all of the tetraploids set some seeds more or less. H052 had the highest seed set (11.22%). The tetraploids had potential for seed production, especially H052, it should be possible to obtain hybrids by cross-pollination in the future.

The Mixed Kernel Function SVM-based Point Cloud Classification

Chao Chen,Xiaomin Li,Abdelkader Nasreddine Belkacem,Zhifeng Qiao,Enzeng Dong,Wenjun Tan,Duk Shin 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.5

Measurement and detection of ground information by airborne Lidar are one of the hot topics in the field of intelligent sensing in recent years. This study proposes a new point cloud classification algorithm of Mixed Kernel Function SVM to distinguish different types of ground objects. Firstly, the combined features including the coordinate values, the RGB value, normalized elevation, standard deviation of elevation, and elevation difference of point cloud data were extracted. A mixed kernel function of Gauss and Polynomial was designed. Then, one-versus-rest SVM multiple classifiers was constructed. Finally, the feature of 3D point cloud data was employed to train the SVM classifiers. The overall classification accuracies of test data were 97.69% and 99.13% for two data sets, I and II respectively. In addition, the experimental results have showed that the performance of the proposed method with mixed kernel function SVM was better than standard SVM method with Gaussian kernel function and polynomial kernel function only, which demonstrates the effectiveness of the proposed method.