Modification of coal tar-based porous carbon and analysis of its structure and electrochemical characteristics

Xu Xinyuan,Wu Peng,Zhou Chunru,Dou Qiang,Lv Yuting 한국탄소학회 2024 Carbon Letters Vol.34 No.1

Oxygen-rich porous carbon is of great interest for energy storage applications due to its improved local electronic structures compared with unmodified porous carbon. However, a tunable method for the preparation of oxygen-rich porous carbon with a special microstructure is still worth developing. Herein, a novel modification of porous carbon with different microstructures is facilely prepared via low-temperature solvothermal and KOH activation methods that employ the coal tar and eight substances, such as cellulose as carbon source and modifier, respectively. By testing the yield, surface group structure, lattice structures, morphology, thermal weight loss, and specific capacitance of carbonaceous mesophase, cellulose–hydrochloric acid is identified as the additive for the preparation of oxygen-rich coal tar-based porous carbon. The obtained porous carbon displays a specific surface area of up to 859.49 m2 g−1 and an average pore diameter of 2.39 nm. More importantly, the material delivers a high capacity of 275.95 F g−1 at 0.3 A g−1 and maintains a high capacitance of 220 F g−1 even at 10 A g−1. When in a neutral electrolyte, it can still retain a reversible capacity of 236.72 F g−1 at 0.3 A g−1 and 136.79 F g−1 at 10 A g−1. This work may provide insight into the design of carbon anode materials with high specific capacity.

Three Degrees of Freedom Global Calibration Method for Measurement Systems with Binocular Vision

Guan Xu,Xinyuan Zhang,Xiaotao Li,Jian Su,Xue Lu,Huanping Liu,Zhaobing Hao 한국광학회 2016 Current Optics and Photonics Vol.20 No.1

We develop a new method to globally calibrate the feature points that are derived from the binocularsystems at different positions. A three-DOF (degree of freedom) global calibration system is establishedto move and rotate the 3D calibration board to an arbitrary position. A three-DOF global calibration modelis constructed for the binocular systems at different positions. The three-DOF calibration model unifiesthe 3D coordinates of the feature points from different binocular systems into a unique world coordinatesystem that is determined by the initial position of the calibration board. Experiments are conducted onthe binocular systems at the coaxial and diagonal positions. The experimental root-mean-square errorsbetween the true and reconstructed 3D coordinates of the feature points are 0.573 mm, 0.520 mm and0.528 mm at the coaxial positions. The experimental root-mean-square errors between the true andreconstructed 3D coordinates of the feature points are 0.495 mm, 0.556 mm and 0.627 mm at the diagonalpositions. This method provides a global and accurate calibration to unity the measurement points ofdifferent binocular vision systems into the same world coordinate system.

Psychological Resilience of Second-Pregnancy Women in China: A Cross-sectional Study of Influencing Factors

Xiaohuan Jin,Xinyuan Xu,Junyan Qiu,Zexun Xu,Lixue Sun,Zhilin Wang,Ling Shan 한국간호과학회 2021 Asian Nursing Research Vol.15 No.2

Purpose The aim of the study was to evaluate the status of psychological resilience among women in their second pregnancy and to investigate the possible influencing factors. Methods A total of 275 women in their second pregnancy and who met the criteria were surveyed from two public hospitals in China from July 2018 to January 2019. The instruments included the General Self-designed Questionnaire, Connor–Davidson Resilience Scale, Social Support Rate Scale, and 36-item Pregnancy Stress Rating Scale. Results The total psychological resilience score of second-pregnancy women was relatively low. Multivariate regression analysis identified five factors associated with psychological resilience: intimacy with husbands, social support utilization, gender of the first child, high-risk pregnancy of the first child, and the stress caused by worrying about the health and safety of the mother and fetus. Conclusion Women in their second pregnancy represent a unique population, and their low psychological resilience score deserves attention. Identification of factors contributing to decreased psychological resilience may enable us to design prevention and intervention strategies and to deliver specific psychological supports to pregnant women at high risk of developing negative psychology.

Dislocation Damping and Defect Friction Damping in Magnesium: Molecular Dynamics Study

Jingyu Zhai,Xinyuan Song,Anyang Xu,Yugang Chen,Qingkai Han 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

In this study, the molecular dynamics method was used to study the damping mechanism in Mg alloys at the atomic scale. The energy dissipated by the nucleation and motion of dislocations and by defects friction, and the effect of defects, such asvacancies, cracks, and grain boundaries, on them were studied. The study shows that different kinds of defect have differenteffects on the dislocation damping and defect friction damping. And then, the effect of strain amplitude and temperature ondamping capacity of Mg was studied. The result shows that the amplitude independent damping is caused by defect frictionand the amplitude dependent damping is mainly caused by the nucleation and motion of dislocation; the damping of Mgincreased exponentially with the temperature, and the damping peck appeared at 440 K is attributed to the appearance ofdislocations at the grain boundaries which may be caused by boundaries self-diffusion.

Decision tree model to efficiently optimize the process conditions of carbonaceous mesophase prepared with coal tar

Zhou Chunru,Wu Peng,Xu Xinyuan,Song Weina 한국탄소학회 2023 Carbon Letters Vol.33 No.2

It is difficult to optimize the process parameters of directly preparing carbonaceous mesophase (CMs) by solvothermal method using coal tar as raw material. To solve this problem, a Decision Tree model for CMs preparation (DTC) was established based on the relationship between the process parameters and the yields of CMs. Then, the importance of variables in the preparation process for CMs was predicted, the relationship between experimental conditions and yields was revealed, and the preparation process conditions were also optimized by the DTC. The prediction results showed that the importance of the variables was raw material type, solvothermal temperature, solvothermal time, solvent amount, and additive type in order. And the optimized reaction conditions were as follows: coal tar was pretreated by decompress distillation and centrifugation, the solvent amount was 50.0 ml, the solvothermal temperature was 230 °C, and the reaction time was 5 h. These prediction results were consistent with the actual experimental results, and the error between the predicted yields and the actual yields was about − 1.1%. Furthermore, the prediction error of DTC method was within the acceptable range when the data sample sets were reduced to 100 sets. These results proved that the established DTC for chemical process optimization can effectively lessen the experimental workload and has high application value.

Heterologous prime-boost immunization with live SPY1 and DnaJ protein of Streptococcus pneumoniae induces strong Th1 and Th17 cellular immune responses in mice

Yulan Qiu,XueMei Zhang,Hong Wang,Xinyuan Zhang,Yunjun Mo,Xiaoyu Sun,Jichao Wang,YiBing Yin,WenChun Xu 한국미생물학회 2017 The journal of microbiology Vol.55 No.10

diseases in children under 5-year-old. Vaccine has been used as an indispensable strategy to prevent S. pneumoniae infection for more than 30 years. Our previous studies confirmed that mucosal immunization with live attenuated strain SPY1 can protect mice against nasopharyngeal colonization of S. pneumoniae and lethal pneumococcal infection, and the protective effects are comparable with those induced by commercially available 23-valent polysaccharide vaccine. However, live attenuated vaccine SPY1 needs four inoculations to get satisfactory protective effect, which may increase the risk of virulence recovery. It is reported that heterologous primeboost approach is more effective than homologous primeboost approach. In the present study, to decrease the doses of live SPY1 and improve the safety of SPY1 vaccine, we immunized mice with SPY1 and DnaJ protein alternately. Our results showed that heterologous prime-boost immunization with SPY1 and DnaJ protein could significantly reduce the colonization of S. pneumoniae in the respiratory tract of mice, and induce stronger Th1 and Th17 cellular immune responses than SPY1 alone. These results indicate heterologous prime-boost immunization method not only elicits better protective effect than SPY1 alone, but also reduces the doses of live SPY1 and decreases the risk of SPY1 vaccine. This work is the first time to study the protective efficiency with two different forms of S. pneumoniae candidate vaccine, and provides a new strategy for the development of S. pneumoniae vaccine.

Population genetics reveals new introgression in the nucleus herd of min pigs

Liu Tianxin,Ji Dongqing,Li Xinyuan,Liu Jiadong,Xu Fei,Miao Zhiying,Chang Yang,Tian Ming,Xu Chunzhu 한국유전학회 2024 Genes & Genomics Vol.46 No.4

Objective Min pigs are a unique genetic resource among local pig breeds in China. They have more excellent characteristics in cold and stress resistance, good meat quality, and a high reproductive rate. However, the genetic structure and driving factors remain unclear in the nucleus herd. In this study, the genetic diversity of Min pigs was studied to reveal the formation mechanism of its unique genetic structure. We hope to protect and develop the genetic resources of Min pigs. Methods We analyzed different types of genes to identify the genetic structure and gene introgression pattern of Min pigs. The nuclear DNA dataset includes information on 21 microsatellite loci and 6 Y-chromosome genes, and the mitochondrial D-loop gene is selected to represent maternal lineages. The above genes are all from the nucleus herd of Min pigs. Results The results of genetic structure identification and analysis of potential exogenous gene introgression patterns indicate that the nucleus herd of Min pigs maintains a high level of genetic diversity (polymorphism information content = 0.713, expected heterozygosity = 0.662, observed heterozygosity = 0.612). Compared with other Asian pig breeds, the formation of Min pig breeds is more special. Gene introgression from European pig breeds to Min pigs has occurred, which is characterized by complete introgression of paternal genes and incomplete introgression of maternal genes. Conclusion Gene introgression caused by cross-breeding is not the main factor leading to the formation of the current genetic structure of Min pigs, but this process has increased the level of genetic diversity in the nucleus herd. Compared with the influence of gene introgression, our research suggest that artificial selection and environmental adaptive evolution make Min pigs form unique genetic characteristics. Objective Min pigs are a unique genetic resource among local pig breeds in China. They have more excellent characteristics in cold and stress resistance, good meat quality, and a high reproductive rate. However, the genetic structure and driving factors remain unclear in the nucleus herd. In this study, the genetic diversity of Min pigs was studied to reveal the formation mechanism of its unique genetic structure. We hope to protect and develop the genetic resources of Min pigs. Methods We analyzed different types of genes to identify the genetic structure and gene introgression pattern of Min pigs. The nuclear DNA dataset includes information on 21 microsatellite loci and 6 Y-chromosome genes, and the mitochondrial D-loop gene is selected to represent maternal lineages. The above genes are all from the nucleus herd of Min pigs. Results The results of genetic structure identification and analysis of potential exogenous gene introgression patterns indicate that the nucleus herd of Min pigs maintains a high level of genetic diversity (polymorphism information content = 0.713, expected heterozygosity = 0.662, observed heterozygosity = 0.612). Compared with other Asian pig breeds, the formation of Min pig breeds is more special. Gene introgression from European pig breeds to Min pigs has occurred, which is characterized by complete introgression of paternal genes and incomplete introgression of maternal genes. Conclusion Gene introgression caused by cross-breeding is not the main factor leading to the formation of the current genetic structure of Min pigs, but this process has increased the level of genetic diversity in the nucleus herd. Compared with the influence of gene introgression, our research suggest that artificial selection and environmental adaptive evolution make Min pigs form unique genetic characteristics.