25-Gb/s OOK Transmission Using 1.5-<tex> $\mu{\rm m}$</tex> 10G-Class VCSEL for Optical Access Network

Zhou, Jingjing,Yu, Changyuan,Mohan, Gurusamy,Kim, Hoon IEEE 2016 Journal of lightwave technology Vol.34 No.16

<P>We explore the possibility of transmitting 25-Gb/s ON-OFF keying (OOK) signals generated by using a 1.5-mu m 10G-class vertical-cavity surface-emitting laser (VCSEL) over standard single-mode fiber (SSMF) for optical access applications. A transistor-outline-can packaged VCSEL having a 3-dB modulation bandwidth of 7 GHz is utilized to transmit the 25-Gb/s signals. We experimentally investigate the transmission performances of OOK signals obtained from two different transmitter schemes: with and without a delay interferometer (DI) at the output of the directly modulated VCSEL. In order to maximize the transmission distance without using bulky and lossy dispersion compensation modules, we optimize the extinction ratio of the signals and apply the electrical equalization at the receiver. Also optimized is the free-spectral range (FSR) of the DI when it is utilized. The experimental results show that we can successfully transmit the 25-Gb/s OOK signals over 33- and 45-km long SSMF with and without the DI, respectively. The use of DI not only alleviates the band limitation of the VCSEL but also significantly improves the receiver sensitivity of the 25-Gb/s OOK signal up to 30 km. Moreover, a larger power budget is achieved for transmission distances shorter than 25 km when a DI having an FSR of 25 GHz is utilized at the output of the VCSEL.</P>

Gender, Personality, and Benefits Sought: Examining Chinese Leisure Travelers

Jingjing Zhou 한국관광학회 2010 International Journal of Tourism Sciences Vol.10 No.3

This paper reports on a study that tested empirically the extent to which tourists’ leisure benefits sought is explained by tourists travel personality and their gender. 348 Chinese potential leisure travelers (convenient sample) participated and successfully finished the on-line survey. Based on the information provided by the respondents, 7 main benefits sought were identified and the respondents were grouped into 4 personality groups based on the psychocentric-allocentric continuum. Furthermore, this study examined the differences of benefits sought among personality groups and gender groups. The study found that there were significant association between the respondents’ tourist personality types, their gender, and their leisure benefits sought, for some benefits factors. The implications for tourism marketing are discussed.

Transmission Performance of OOK and 4-PAM Signals Using Directly Modulated 1.5-μm VCSEL for Optical Access Network

Jingjing Zhou,Changyuan Yu,Hoon Kim IEEE 2015 Journal of lightwave technology Vol.33 No.15

<P>We evaluate the possibility of realizing optical access networks using 1.5-mu m vertical-cavity surface-emitting lasers (VCSELs) in the on-off keying (OOK) and four-level pulse amplitude modulation (4-PAM) formats. In order to maximize the power budget of the networks, we optimize the extinction ratio of the 10.7- and 21.4-Gb/s signals and exploit the electrical equalization at the receiver. The experimental comparison made at 10.7 Gb/s shows that the OOK format vastly outperforms the 4-PAM format in terms of tolerance to chromatic dispersion. For example, we achieve the 80-km transmission of the OOK signal over standard single-mode fiber (SSMF), but the maximum reach is halved when the 4-PAM signal is employed. Nevertheless, the 4-PAM format is still an effective way to double the data rate of the VCSEL links in optical access networks. We successfully transmit the 21.4-Gb/s 4-PAM signal generated by using the 1.5-mu m VCSEL over 18-km long SSMF.</P>

DNA Vaccines Encoding Toxoplasma gondii Cathepsin C1 Induce Protection against Toxoplasmosis in Mice

Yali Han,Aihua Zhou,Gang Lu,Guanghui Zhao,Wenchao Sha,Lin Wang,Jingjing Guo,Jian Zhou,Huaiyu Zhou,Hua Cong,Shenyi He 대한기생충학열대의학회 2017 The Korean Journal of Parasitology Vol.55 No.5

Phosphorylation of Silk Fibroin via Maillard Reaction and Its Behavior of Biomimetic Mineralization

Jingjing Yuan,Qian Zhou,Ping Wang,Chao Deng,Jiugang Yuan,Qiang Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.8

Silk fibroin (SF) has the characteristics of non-toxicity, good biocompatibility and low immunogenicity, andexhibits many potential applications in biomaterial fields. In the present work, chemical phosphorylation of SF was carriedout via the Maillard reaction using D-glucose-6-phosphate (GP), aiming at increasing the number of binding-sites forcalcium ion and promoting the biomimetic mineralization of SF films. Changes in the molecular weight of SF before andafter GP grafting were analyzed by SDS-PAGE and SEC chromatogram. Structures, morphologies, and elementalcompositions for the fibroin-based films before and after mineralization were evaluated by the means of EDS, SEM, FTIR,and XRD. The results indicated that GP was successfully grafted onto SF surfaces, companying with a slight decrease in themolecular weight. Biomimetic mineralization led to a noticeable deposition of hydroxyapatite (HAp) on the film of SF-g-GP, and higher contents of calcium and phosphorous were detected on the mineralized material, revealing thatphosphorylation promoted the mineralization processing. Meanwhile, biocompatibility of the obtained SF-g-GP/HAp wasabove the acceptable level according to ISO 10993-5-2009. The present work provides an alternative to prepare the fibroinbasedbone repair materials.

Simple fabrication of N-doped mesoporous TiO ₂ nanorods with the enhanced visible light photocatalytic activity

Zhou, Xiufeng,Lu, Juan,Jiang, Jingjing,Li, Xiaobin,Lu, Mengna,Yuan, Guotao,Wang, Zuoshan,Zheng, Min,Seo, Hyo Jin Springer 2014 NANOSCALE RESEARCH LETTERS Vol.9 No.1

<P>N-doped mesoporous TiO<SUB>2</SUB> nanorods were fabricated by a modified and facile sol–gel approach without any templates. Ammonium nitrate was used as a raw source of N dopants, which could produce a lot of gasses such as N<SUB>2</SUB>, NO<SUB>2</SUB>, and H<SUB>2</SUB>O in the process of heating samples. These gasses were proved to be vitally important to form the special mesoporous structure. The samples were characterized by the powder X-ray diffraction, X-ray photoelectron spectrometer, nitrogen adsorption isotherms, scanning electron microscopy, transmission electron microscopy, and UV-visible absorption spectra. The average length and the cross section diameter of the as-prepared samples were <I>ca</I>. 1.5 μm and ca. 80 nm, respectively. The photocatalytic activity was evaluated by photodegradation of methylene blue (MB) in aqueous solution. The N-doped mesoporous TiO<SUB>2</SUB> nanorods showed an excellent photocatalytic activity, which may be attributed to the enlarged surface area (106.4 m<SUP>2</SUP> g<SUP>-1</SUP>) and the narrowed band gap (2.05 eV). Besides, the rod-like photocatalyst was found to be easy to recycle.</P>

Mechanical Stimulation and Diameter of Fiber Scaffolds Affect the Differentiation of Rabbit Annulus Fibrous Stem Cells

Zhou Pinghui,Wei Bangguo,Guan Jingjing,Chen Yu,Zhu Yansong,Ye Yuchen,Meng Yue,Guan Jianzhong,Mao Yingji 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.1

BACKGROUND: Degeneration of the annulus fibrosus (AF), an important structure of the intervertebral disc, is one of the main causes of degenerative disc disease. Fabrication of scaffolds replicating the stratified microstructure of the AF is critical for the successful regeneration of AF. METHODS: In this study, we cultured rabbit AF-derived stem cells (AFSCs) using fabricated electrospun fibrous poly-L-lactic acid scaffolds with different diameters. We applied cyclic tensile strain (CTS) on the scaffolds to regulate the differentiation of AFSCs into specific cell types that resided at the inner, middle, and outer zones of the AF. RESULTS: We found that the morphologies of AFSCs on the smaller-fiber-diameter scaffolds were nearly round, whereas spindle-like cells morphologies were observed on large-diameter scaffolds. CTS enhanced these phenomena and made the cells slender. The expression levels of collagen-I in cells increased as a function of the fiber diameter, whereas collagen-II and aggrecan exhibited opposite trends. Moreover, the application of CTS upregulated the gene expressions of collagen-I, collagen-II, and aggrecan. CONCLUSION: Overlaying the scaffolds with different CTS-stimulated cells could eventually lead to engineered AF tissues with hierarchical structures that approximated the native AF tissue. Thus, the proposed methodologies could be potentially applied for AF regeneration. BACKGROUND: Degeneration of the annulus fibrosus (AF), an important structure of the intervertebral disc, is one of the main causes of degenerative disc disease. Fabrication of scaffolds replicating the stratified microstructure of the AF is critical for the successful regeneration of AF. METHODS: In this study, we cultured rabbit AF-derived stem cells (AFSCs) using fabricated electrospun fibrous poly-L-lactic acid scaffolds with different diameters. We applied cyclic tensile strain (CTS) on the scaffolds to regulate the differentiation of AFSCs into specific cell types that resided at the inner, middle, and outer zones of the AF. RESULTS: We found that the morphologies of AFSCs on the smaller-fiber-diameter scaffolds were nearly round, whereas spindle-like cells morphologies were observed on large-diameter scaffolds. CTS enhanced these phenomena and made the cells slender. The expression levels of collagen-I in cells increased as a function of the fiber diameter, whereas collagen-II and aggrecan exhibited opposite trends. Moreover, the application of CTS upregulated the gene expressions of collagen-I, collagen-II, and aggrecan. CONCLUSION: Overlaying the scaffolds with different CTS-stimulated cells could eventually lead to engineered AF tissues with hierarchical structures that approximated the native AF tissue. Thus, the proposed methodologies could be potentially applied for AF regeneration.

Electronic structure and optical properties for blue phosphorene/ graphene-like GaN van der Waals heterostructures

Jingjing Guo,Zhongpo Zhou,Tianxing Wang,Zhansheng Lu,Zongxian Yang,Chang Liu 한국물리학회 2017 Current Applied Physics Vol.17 No.12

In this paper, first-principle calculations based on density functional theory are carried out to explore the interface properties of the blue phosphorene/graphene-like GaN van der Waals heterostructures. The edge positions for valence and conduction band of blue phosphorene and graphene-like GaN nanosheets change with the Fermi energy level and form the type-II heterostructure. The internal electric field facilitates the separation of electronhole pairs and restrained the carrier recombination in the blue phosphorene/graphene-like GaN interfaces.

LAMP, PCR, and real-time PCR detection of Acetobacter aceti in yogurt

Wei Zhou,Yan Zhang,Shuang Wang,Yuehua Li,Jingjing Zhang,Cuixia Zhang,Zan Wang,Zhisheng Zhang 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.1

Acetic acid bacteria (AAB) can spoil food. Acetobacter aceti as a core subgroup of AAB is usually isolated from yogurt. A. aceti should be timely and effectively detected to prevent yogurt contamination. The present study focused on A. aceti to establish an assay that can be performed to detect AAB in yogurt. LAMP, PCR, and real-time PCR were applied and compared for detecting A. aceti from pure culture and artificially contaminated yogurt samples. In pure culture, LAMP showed the highest detection sensitivity with 10−1 CFU/mL. For yogurt samples, the sensitivity limit of LAMP was 102 CFU/mL, which was lower than that of real-time PCR (101 CFU/mL). The results indicated that these methods could be quickly and efficiently applied to detect A. aceti. As LAMP technology has low cost and high detection efficiency, it can potentially be applied for detecting A. aceti in production and quality control programs of yogurt.

Theoretical Research and Simulation Analysis on the Cutter Spacing of Double Disc Cutters Breaking Rock

Peng Zhou,Jingjing Guo,Jian Sun,Defang Zou 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

The arrangement of disc cutter on a cutter head is important to improve the performance of TBM (tunnel boring machine) cutter, cutter life and cutter disc bearing life, then reduce vibration of TBM and reduce the noise. The rock breaking with double disc cutters is the basis of study on the distribution of disc cutter on cutter head, and it plays an important role on optimum arrangement of disc cutter on cutter head. In the process of rock breaking with double disc cutters, the axial vertical distance between two cutters is an important construction parameter, which directly affects rock breaking efficiency. Therefore, research on optimal cutter spacing and analysis of adaptability between cutter spacing and rock characteristics play an important role in optimizing the arrangement of cutter on the cutter head and improving the rock breaking efficiency of TBM. This paper analyzed the breaking rock force of double disc cutters. Taking granite samples as an example, the process of rock breaking with double disc cutters was simulated. Then rock fragmentation analysis based on different cutter spacing was carried out. Finally, the rock of different cutter spacing adaptability was studied. A series of conclusions about double disc cutters breaking rock were drawn.