Terahertz Characteristics of Hydroxygraphene Based on Microfluidic Technology

Boyan Zhang,Siyu Qian,Bo Peng,Bo Su,Zhuang Peng,Hailin Cui,Shengbo Zhang,Cunlin Zhang 한국광학회 2023 Current Optics and Photonics Vol.7 No.4

Hydroxygraphene as a kind of functionalized graphene has important applications in composite, photoelectric and biological materials. In the present study, THz and microfluidic technologies were implemented to study the THz transmission characteristics of hydroxygraphene with different concentrations and residence times in magnetic and electric fields. The results show that the THz transmission intensity decreases with the increase in sample concentration and duration of an applied electric field, while it increases by staying longer in the magnetic field. The phenomenon is analyzed and explained in terms of hydrogen bond, conductivity and scattering characteristics. The results establish a foundation for future research on the THz absorption characteristics of liquid graphene based on microfluidic technology in different external environments. It also provides technical support for the application and development of graphene in THz devices.

An Investigation of the Terahertz Absorption Characteristics of a Graphene Oxide Aqueous Solution Using Microfluidic Technology

Ningyi Cai,Boyan Zhang,Qinghao Meng,Siyu Qian,Bo Su,Hailin Cui,Shengbo Zhang,Cunlin Zhang 한국광학회 2023 Current Optics and Photonics Vol.7 No.2

The vibratory and rotational levels of many biological macromolecules lie in the terahertz (THz) band, which means that THz techniques can be used to identify and detect them. Moreover, since the biological activity of most biomolecules only becomes apparent in aqueous solution, we use microfluidic technology to study the biological properties of these biomolecules. THz time-domain spectroscopy was used to study the THz absorption characteristics of graphene oxide (GO) aqueous solution at different concentrations and different exposure times in fixed electric or magnetic fields. The results show that the spectral characteristics of the GO solution varied with the concentration: as the concentration increased, the THz absorption decreased. The results also show that after placing the solution in an external electric field, the absorption of THz first increased and then decreased. When the solution was placed in a magnetic field, the THz absorption increased with the increase in standing time. In this paper, these results are explained based on considerations of what is occurring at the molecular scale. The results of this study provide technical support for the further study of GO and will assist with its improved application in various fields.

Nolinear Multi-component Spectroscopy Analysis Based on Evolutionary Construction Optimazation

Boyan Cai,Hui Cao,Yanbin Zhang,Lixin Jia,Gangquan Si,Zhongjian Li 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

Spectroscopy has been widely used to evaluate product quality or to predict components. To deal with the nonlinearity of spectral data, artificial neural networks (ANN) are widely used. One weakness of ANN is we have no accurate analytical method to design a optimal network structure. A multivariate component prediction method based on optimized neural network combined with evolutionary algorithm (EA) for spectral analysis is proposed in the paper. For the proposed method, ANNs are combined with nonlinear adaptive evolutionary programming algorithm (NAEP) to evolve ANNs architecture including the number of hidden nodes and the number of hidden layers. And the root-meansquares error of cross-validation (RMSECV) is the fitness function of NAEP. In order to present the effectiveness of this method, back propagation neural network (BP) and ANN with genetic algorithm (ANN-GA) methods were also used for component predicting models. An application research has been demonstrated with spectral data which is recorded in an experiment of meat content determination. Results indicate that our method has the ability to design the best ANN structure to predict more accurate and robust as a practical spectral analysis tool.

Facile Preparation of Polymer-Grafted Halloysite Nanotubes via a Redox System: a Novel Approach to Construct Antibacterial Hydrogel

Yanfang Ma,Zhihang Zhao,Boyan Tang,Yonggang Wu,Hailei Zhang 한국고분자학회 2020 Macromolecular Research Vol.28 No.10

We demonstrate the use of a supernormal valence transition-metal (Ce(IV) and Cu(III))-mediated redox system for the surface grafting on the halloysite nanotubes (HNTs). Following this way, commonly-used vinyl monomers were grafted on HNTs in one step under mild condition. The grafting was evidenced using FTIR, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The micromorphology was carefully characterized by transmission electron microscope (TEM). The results indicate that the surface grafting reaction was successfully processed in all cases, in which the Ce(IV) shows a much higher initiation activity than that of Cu(III). Then a uniform hydrogel was constructed by mixing poly(triethyl(4-vinylbenzyl)phosphonium chloride-grafted HNTs (HNTs-P(Et-P)) with sodium polyacrylate-grafted HNTs (HNTs-P(AA-Na)), which show desirable antibacterial activity.

Terahertz Spectroscopy and Molecular Dynamics Simulation of Five Citrates

Siyu Qian,Bo Peng,Boyan Zhang,Jingyi Shu,Zhuang Peng,Bo Su,Cunlin Zhang 한국광학회 2024 Current Optics and Photonics Vol.8 No.1

This research investigation employs a terahertz time-domain spectroscopy (THz-TDS) system to study the terahertz (THz) spectral characteristics of five different citrates in both solution and solid state. The citrates under examination are lithium citrate, monosodium citrate, disodium citrate, trisodium citrate, and potassium citrate. The results show that the THz absorption coefficients of the first four citrate solutions exhibit a decreasing trend with increasing concentration. However, the potassium citrate solution shows an opposite phenomenon. At the same time, the absorption coefficients of lithium citrate, trisodium citrate, and potassium citrate solutions are compared at the same concentration. The results indicate that the absorption coefficient of citrate solution increases in proportion to the increase of metal cation radius, which is explained from the perspective of the influence of metal cations on hydrogen bonds. In addition, we also study the absorption peaks of solid citrates, and characterize the formation mechanism of the absorption peaks by molecular dynamics (MD) simulations. This methodology can be further extended to the study of multitudinous salts, presenting theoretical foundations for the detection in food and medicine industries.

Combined Application Effects of Arbuscular Mycorrhizal Fungi and Biochar on the Rhizosphere Fungal Community of Allium fistulosum L.

Ji Chunxiang,Li Yingyue,Xiao Qingchen,Li Zishan,Wang Boyan,Geng Xiaowan,Lin Keqing,Zhang Qing,Jin Yuan,Zhai Yuqian,Li Xiaoyu,Chen Jin 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.8

Arbuscular mycorrhizal fungi (AMF) are widespread soil endophytic fungi, forming mutualistic relationships with the vast majority of land plants. Biochar (BC) has been reported to improve soil fertility and promote plant growth. However, limited studies are available concerning the combined effects of AMF and BC on soil community structure and plant growth. In this work, a pot experiment was designed to investigate the effects of AMF and BC on the rhizosphere microbial community of Allium fistulosum L. Using Illumina high-throughput sequencing, we showed that inoculation of AMF and BC had a significant impact on soil microbial community composition, diversity, and versatility. Increases were observed in both plant growth (the plant height by 8.6%, shoot fresh weight by 12.1%) and root morphological traits (average diameter by 20.5%). The phylogenetic tree also showed differences in the fungal community composition in A. fistulosum. In addition, Linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed that 16 biomarkers were detected in the control (CK) and AMF treatment, while only 3 were detected in the AMF + BC treatment. Molecular ecological network analysis showed that the AMF + BC treatment group had a more complex network of fungal communities, as evidenced by higher average connectivity. The functional composition spectrum showed significant differences in the functional distribution of soil microbial communities among different fungal genera. The structural equation model (SEM) confirmed that AMF could improve the microbial multifunctionality by regulating the rhizosphere fungal diversity and soil properties. Our findings provide new information on the effects of AMF and biochar on plants and soil microbial communities.