Background Error Statistics for Aerosol Variables from WRF/Chem Predictions in Southern California

Zengliang Zang,Zilong Hao,Xiaobin Pan,Zhijin Li,Dan Chen,Li Zhang,Qinbin Li 한국기상학회 2015 Asia-Pacific Journal of Atmospheric Sciences Vol.51 No.2

Background error covariance (BEC) is crucial in data assimilation. This paper addresses the multivariate BEC associated with black carbon, organic carbon, nitrates, sulfates, and other constituents of aerosol species. These aerosol species are modeled and predicted using the Model for Simulating Aerosol Interactions and Chemistry scheme (MOSAIC) in the Weather Research and Forecasting/Chemistry (WRF/Chem) model at a resolution of 4 km in Southern California. The BEC is estimated from the differences between the 36-hour and 12-hour forecasts using the NMC method. The results indicated that the maximum background error standard deviation is associated with nitrate and is larger than that of black carbon, organic carbon, and sulfate. The horizontal and vertical scale of the correlation of nitrate is much smaller than that of other species. A significant cross-correlation is found between the species of black carbon and organic carbon. The cross-correlations between nitrate and other variables are relatively smaller and exhibit a relatively smaller length scale. Single observation data assimilation experiments are performed to illustrate the effect of the BEC on analysis increments.

Spatio-Temporal Residual Networks for Slide Transition Detection in Lecture Videos

( Zhijin Liu ),( Kai Li ),( Liquan Shen ),( Ran Ma ),( Ping An ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.8

In this paper, we present an approach for detecting slide transitions in lecture videos by introducing the spatio-temporal residual networks. Given a lecture video which records the digital slides, the speaker, and the audience by multiple cameras, our goal is to find keyframes where slide content changes. Since temporal dependency among video frames is important for detecting slide changes, 3D Convolutional Networks has been regarded as an efficient approach to learn the spatio-temporal features in videos. However, 3D ConvNet will cost much training time and need lots of memory. Hence, we utilize ResNet to ease the training of network, which is easy to optimize. Consequently, we present a novel ConvNet architecture based on 3D ConvNet and ResNet for slide transition detection in lecture videos. Experimental results show that the proposed novel ConvNet architecture achieves the better accuracy than other slide progression detection approaches.

Hydrodynamic Description for the Pseudorapidity Distributions of the Charged Particles Produced in Nucleus+Nucleus Collisions at High Energy

Haili Zhang,Zhijin Jiang,Qingguang Li,Guanxiang Jiang 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.3

By using the revised Landau hydrodynamic model and taking into account the effect of leadingparticles, we discuss the pseudorapidity distributions of the charged particles produced in highenergyheavy-ion collisions. The leading particles are assumed to have the rapidity distributions withGaussian forms with the normalization constant being equal to the number of participants, whichcan be figured out in theory. The results from the revised Landau hydrodynamic model, togetherwith the contributions from leading particles, were found to be consistent with the experimentaldata obtained by the PHOBOS Collaboration on RHIC (Relativistic Heavy Ion Collider) at BNL(Brookhaven National Laboratory) in different centrality Cu+Cu and Au+Au collisions at highenergies.

Synthesis and self-assembly of rod-coil molecules with n-shaped rod building block

Zhong, Ke-Li,Huang, Zhegang,Man, Zhijin,Jin, Long Yi,Yin, Bingzhu,Lee, Myongsoo Wiley Subscription Services, Inc., A Wiley Company 2010 Journal of polymer science Part A, Polymer chemist Vol.48 No.6

<P>The rod-coil molecules with n-shaped rod building block, consisting of an anthracene unit and two biphenyl groups linked together with acetylenyl bonds at the 1,8-position of anthracene as a rigid rod segment, and the alkyl or alkyloxy chains with various length (i.e., methoxy- (1), octyl- (2), hexadecyl- (3)) at the 10-position of anthracene and poly(ethylene oxide) with the number of repeating units of 7 connected with biphenyl as coil segments were synthesized. The molecular structures were characterized by <SUP>1</SUP>H NMR and MALDI-TOF mass spectroscopy. The self-assembling behavior of new type of molecules 1–3 was investigated by means of DSC, POM, and SAXS at the bulk state. These molecules with a n-shaped rod building block segment self-assemble into supramolecular structures through the combination of π–π stacking of rigid rod building blocks and microphase separation of the rod and coil blocks. SAXS studies reveal that molecules 1 and 2 show hexagonal columnar and rectangular columnar structures in the liquid crystalline phase, respectively; meanwhile, molecules 1–3 self-organize into lamellar structures in the crystalline state. In addition, self-assembling studies of molecules 1–3 by DLS and TEM indicated that these molecules self-assemble into elongated nanofibers in aqueous medium. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1415–1422, 2010</P> <B>Graphic Abstract</B> <P>Rod-coil molecules with n-shaped rod building block were successfully synthesized. In the melt state, molecule with a methoxy group at 10 position of anthracene self-assembles into hexagonal columnar structure, Whereas molecule with an octanyl group at 10 position of anthracene self-organizes into rectangular columnar structure. Further increasing the length of alkyl chain suppresses a liquid crystalline phase and exhibits only a lamellar structure in the solid state. In aqueous medium, these molecules can self-assemble into elongated nanofiber structure with a radial aggregation of aromatic segments. <img src='wiley_img/0887624X-2010-48-6-POLA23909-gra001.gif' alt='wiley_img/0887624X-2010-48-6-POLA23909-gra001'> </P>

Association analysis of polymorphism in the NR6A1 gene with the lumbar vertebrae number traits in sheep

Xiangyu Zhang,Cunyuan Li,Xiaoyue Li,Zhijin Liu,Wei Ni,Yang Cao,Yang Yao,Esenbay Islamov,Junchang Wei,Xiaoxu Hou,Shengwei Hu 한국유전학회 2019 Genes & Genomics Vol.41 No.10

Introduction The vertebral number is an economically significant trait, which is associated with body length and carcass traits. Nuclear Receptor Subfamily 6, Group A, Member 1 (NR6A1) is a member of the nuclear receptor superfamily and it plays an important role in the early development of embryos. Objectives The NR6A1 gene was considered as an important candidate for influence vertebrae number, while the potential associations between this gene and the number of lumbar vertebrae traits of sheep have not been explored. Methods In this study, we detected the genetic variants of NR6A1 gene and analyzed the associations of the polymorphisms with lumbar number traits in 130 Kazakh sheep. We use single-strand conformation polymorphism (SSCP) technique to detect single nucleotide polymorphism (SNP) of NR6A1 gene, and the association of the genotype and lumbar number variation was analyzed by independent Chi-square test. Results We detect SNP of NR6A1 gene by PCR-SSCP technique, and polymorphisms were only found in the coding region of exon-6 and exon-8 of NR6A1 gene. In order to investigate the connection between the SNP locus and lumbar number traits in sheep, we conducted a Chi-square test for independence for exon-6 and exon-8 of NR6A1 gene, respectively. Association analysis revealed significant associations between the SNP (rs414302710: A >C) in the exon-8 of NR6A1 gene with the number of lumbar vertebrae (P < 0.01). Conclusion Our study indicated that this SNP (rs414302710: A>C) locus of exon-8 of NR6A1 gene in sheep possible influence the number of lumbar vertebrae, which has the potential to be applied in selective breeding of sheep.

A New Method of Gelatin Modified Collagen and Viscoelastic Study of Gelatin-Collagen Composite Hydrogel

Lang He,Sheng Li,Chengzhi Xu,Benmei Wei,Juntao Zhang,Yuling Xu,Beirong Zhu,Yang Cao,Xilin Wu,Zhijin Xiong,Rongrui Huang,Jian Yang,Haibo Wang 한국고분자학회 2020 Macromolecular Research Vol.28 No.9

Pure collagen materials are expensive with poor mechanical properties, which need modifications in most cases. As the degradation product of collagen, gelatin is cheap, degradable and biocompatible, but few literatures have reported the research about gelatin-collagen composite materials. This is because gelatin and collagen have different soluble temperatures—gelatin is soluble in hot water (≥30 oC) and swells in cold water. However, a low temperature (2-10 oC) is required to prepare and store collagen solution, and neutral collagen solution denatures quickly above the room temperature. In this study, gelatin was ground into powders and swelled in neutral bovine tendon pepsin-soluble collagen solution (BPSC) to form a homogeneous gelatin-collagen mixture, in light of the swelling characteristics of gelatin in cold water. The assembly properties and gel properties of this composite material were further studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) test results showed that the bovine tendon collagen had typical type-I collagen structural characterizations with two α chains of about 100 kDa and one β chain of about 200 kDa; while the SDS-PAGE pattern of gelatin displayed bands continuously distributed from 30 to 200 kDa. Amino acid composition analysis test indicated that the content of polar amino acids and the sum of acidic and base amino acids for gelatin were higher than that of BPSC. Studies on gel properties demonstrated that gelatin-collagen mixed solution had collagenlike assembly characteristics and assembly kinetics. The moduli of the assembled gel at 35 oC were equivalent to that of pure bovine tendon collagen system; moreover, the system moduli didn’t change with time with elastic moduli (G') of about 40 Pa. However, at 25 oC, the moduli of gelatin-collagen composite hydrogel increased with the extension of time, its G' increased about 18 times within 8 h, and the ratio of elastic modulus to viscous modulus (G'') increased 4.6 times, showing a significant aging effect of structural strength. Meanwhile, the mechanical strength of the composite hydrogel was also regulated by temperature—the gel was highly elastic (G'≈3,000 Pa, G'>>G'') at a low temperature (5 oC); as the temperature rose, the system moduli gradually decreased and the elastic gel transformed into waterlike fluid at 50 oC little by little. What’s more, gelatin-collagen composite hydrogel also had reversible sol-gel performances and self-healing capability similar to the gelatin hydrogel. This novel preparation method for preparing composite materials and the resultant composite hydrogel are expected to be used in the fields of natural food gels, injectable hydrogels, cell scaffolds, drug sustained-release materials and so on, and improve and promote the processing performances, price and large-scale production of collagen-based materials.

Mental Health Problems of Individuals Under the Stay-Home Policy

Wang Hayson Chenyu,Ting Wenyun,Li Zhijin,Sun Elliot Tianyu,Wang Xiaojun 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.7