CO2 Adsorption on the B12N12 Nanocage Encapsulated with Alkali Metals: A Density Functional Study

Haiyan Zhu,Qiyan Zhang,Qinfu Zhao,He Zhao,Yifan Feng,Bingbing Suo,Huixian Han,Qi Song,Yawei Li,Wenli Zou,Haiyan Zhu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

Density functional theory (DFT) calculations have been carried out to study the capacity of the B12N12 nanocage encapsulated with alkali metals (Li, Na, K) for the CO2 adsorption and activation. It is found that after encapsulating alkali metals, the alkali metal atoms are closer to one side of clusters instead of exactly lying at the center, and a considerable charge transfers from the inner alkali metal atoms to the B12N12 cage. Besides, the HOMO–LUMO gap (HLG) values of Li@B12N12, Na@B12N12 and K@B12N12 are decreased to about 6 eV, being much smaller than that of the pristine B12N12. Although the geometry structure parameters and the energy differences of M06-2X are slightly different from the ones of ωB97X-D, some identical results of two kinds of functional can be obtained. CO2 can be adsorbed chemically and physically on majority bonds of all the clusters, except for some bonds with large change in bond length and bond indices. The encapsulation of alkali-metal atoms may enhance the physical and chemical adsorption of CO2 on the surface of the clusters, in which Na@B12N12 and K@B12N12 are the most powerful physical and chemical adsorbent for CO2, respectively.

Direct Synthesis of H2O2 over Ti-Containing Molecular Sieves Supported Gold Catalysts: A Comparative Study for In-situ-H2O2-ODS of Fuel

Han Zhang,Guangliang Liu,Haiyan Song,Chunxia Chen,Fuqin Han,Ping Chen,Zhixi Zhao,Shaozheng Hu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.10

Direct synthesis of H2O2 and in situ oxidative desulfurization of model fuel over Au/Ti-HMS and Au/TS-1 catalysts has been comparatively investigated in water or methanol. Maximum amount (82%) of active Au0 species for H2O2 synthesis was obtained. Au/Ti-HMS and Au/TS-1 exhibited the contrary performances in H2O2 synthesis as CH3OH/H2O ratio of solvent changed. H2O2 decomposition and hydrogenation in water was inhibited by the introduction of methanol. Effect of O2/H2 ratio on H2O2 concentration, H2 conversion and H2O2 selectivity revealed a relationship between H2O2 generation and H2 consumption. The highest dibenzothiophene removal rate (83.2%) was obtained over Au/Ti-HMS in methanol at 1.5 of O2/H2 ratio and 60 oC. But removal of thiophene over Au/TS-1 should be performed in water without heating to obtain a high removal rate (61.3%). Meanwhile, H2 conversion and oxidative desulfurization selectivity of H2 were presented.

Direct Synthesis of H₂O₂ over Ti-Containing Molecular Sieves Supported Gold Catalysts: A Comparative Study for In-situ-H₂O₂-ODS of Fuel

Zhang, Han,Liu, Guangliang,Song, Haiyan,Chen, Chunxia,Han, Fuqin,Chen, Ping,Zhao, Zhixi,Hu, Shaozheng Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.10

Direct synthesis of $H_2O_2$ and in situ oxidative desulfurization of model fuel over Au/Ti-HMS and Au/TS-1 catalysts has been comparatively investigated in water or methanol. Maximum amount (82%) of active $Au^0$ species for $H_2O_2$ synthesis was obtained. Au/Ti-HMS and Au/TS-1 exhibited the contrary performances in $H_2O_2$ synthesis as $CH_3OH/H_2O$ ratio of solvent changed. $H_2O_2$ decomposition and hydrogenation in water was inhibited by the introduction of methanol. Effect of $O_2/H_2$ ratio on $H_2O_2$ concentration, $H_2$ conversion and $H_2O_2$ selectivity revealed a relationship between $H_2O_2$ generation and $H_2$ consumption. The highest dibenzothiophene removal rate (83.2%) was obtained over Au/Ti-HMS in methanol at 1.5 of $O_2/H_2$ ratio and $60^{\circ}C$. But removal of thiophene over Au/TS-1 should be performed in water without heating to obtain a high removal rate (61.3%). Meanwhile, $H_2$ conversion and oxidative desulfurization selectivity of $H_2$ were presented.

Industries TFP and Environmental Regulation Cost Analysis Using Malmquist Luenberger

Haiyan Wang,Liting Shen,Chunlan Liu,Hui Han 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.2

Environmental problem is a worldwide focus, so is the effect of environmental regulation on economy. In this paper, we constructed a model including energy consumption and integrated pollutant emissions of "Three wastes" as "bad" output. This studyr used Malmquist –Luenberger based on directional distance function to measure TFP and environmental regulation cost of Chinese 36 industries from 2001 to 2010. The result was that: From the overall analysis, the TFP was lower after considering the environmental regulation. Technological progress was the main driver of productivity growth. Environmental regulation brought about a certain cost; from the industry analysis, Difference of TFP growth and the cost of environmental regulation existed among different industries. The monopoly and heavy industries were the focus in the industry; from the annual analysis, TFP increased during "Eleventh Five-Year Plan" period, mainly drived by technological progress.

Associations between Quality of Life and Marital Status in Cancer Patients and Survivors

Han, Kyu-Tae,Kim, Sun Jung,Song, Haiyan,Chun, Sung-Youn,Kim, Chan Ok,Kim, Jung-Soo,Park, Eun-Cheol Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: The cancer survival rate in Korea has substantially increased, necessitating the management of not only patients with cancer but also longer term survivors. Although the divorce rate has drastically increased in Korea, there is not sufficient research regarding the relationship between changes in marital status and quality of life (QOL) in cancer patients and survivors. Thus, we aimed to examine the relationship between marital status and QOL in such cases. Materials and Methods: This study was performed using the Community Health Survey of 2008 administered by the Korea Centers for Disease Control and Prevention (N=169,328). We used t-tests and Chi-square tests to compare demographic variables between men and women, and analysis of variance (ANOVA) to compare QOL scores among comparison groups. We also performed a multilevel analysis on the relationship between QOL and marital status while accounting for provincial differences. Results: Decline of EuroQOL five dimensions (EQ-5D) in single patients with cancer was greater than in any other marital status group, but there was no statistically significant decline in survivors of cancer with regard to marital status. In the general population, the decline of EQ-5D was higher among single people than married people. Using the EuroQOL visual analog scale (EQ-VAS), single people had higher values than those of other marital status among both patients with cancer and survivors of cancer. In the general population, EQ-VAS values were higher for single people compared to married people. Conclusions: There may be a significant relationship between marital status and QOL in cancer patients and survivors. Policy interventions to manage patients with cancer who experience a decline in QOL as well as marital problems should be conducted.

Structural evolution of the thermal conversion products of modified coal tar pitch

Qi Li,Dongyun Han,Haiyan Qiao,Weiwei Shi,Yuqi Zhang,Zubin Cao 한국탄소학회 2023 Carbon Letters Vol.33 No.1

Coal tar pitch is a product with high carbon content and aromatic compounds. Modified coal tar pitch is a high quality raw material for the preparation of intermediate phase pitch, needle coke, carbon microspheres, et al. In this paper, modified coal tar pitch was used as raw material, nitrogen was used as protective gas, and thermal conversion was carried out at constant temperatures (370, 390, 410, 420 °C). Polarized light microscopy, SEM, elemental analysis, FTIR spectroscopy, Raman spectroscopy and XRD diffraction combined with split-peak fitting were used to characterize the microstructures of the thermal transformation products. The results showed that the Iar and CH3/ CH2 contents of the products increased with the gradual increase of the thermal conversion temperature, and the aromatic content increased. And the higher the temperature at the same heating rate, the more the ideal graphite microcrystal content, and the defective graphite microcrystals are converted into ideal graphite microcrystals during the thermal conversion process. When the reaction temperature exceeds 390 °C, the microstructure of the thermal transformation products is anisotropic spheres, and the small spheres fuse with each other and tend to be basin-like and mosaic structure as the temperature increases.

Dynamics of high-speed train in crosswinds based on an air-train-track interaction model

Wanming Zhai,Jizhong Yang,Zhen Li,Haiyan Han 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.2

A numerical model for analyzing airtraintrack interaction is proposed to investigate thedynamic behavior of a high-speed train running on a track in crosswinds. The model is composed of atraintrack interaction model and a trainair interaction model. The traintrack interaction model is built onthe basis of the vehicletrack coupled dynamics theory. The trainair interaction model is developed basedon the train aerodynamics, in which the Arbitrary LagrangianEulerian (ALE) method is employed to dealwith the dynamic boundary between the train and the air. Based on the airtraintrack model, characteristicsof flow structure around a high-speed train are described and the dynamic behavior of the high-speed trainrunning on track in crosswinds is investigated. Results show that the dynamic indices of the head car arelarger than those of other cars in crosswinds. From the viewpoint of dynamic safety evaluation, the runningsafety of the train in crosswinds is basically controlled by the head car. Compared with the generally usedassessment indices of running safety such as the derailment coefficient and the wheel-load reduction ratio,the overturning coefficient will overestimate the running safety of a train on a track under crosswindcondition. It is suggested to use the wheel-load reduction ratio and the lateral wheelrail force as thedominant safety assessment indices when high-speed trains run in crosswinds.

Exploring Resident’s Daily Activity-Travel Behavior: Activity Pattern, Duration and Competition

Wanying Li,Hongzhi Guan,Yan Han,Haiyan Zhu,Pengfei Zhao 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.8

This paper aims to deeply analyze the regularity of residents' daily activity-travel behaviors to help traffic management departments predict travel demand and evaluate transportation policies. Taking time use data in American as empirical analysis, the influencing factors such as residents’ activity pattern, duration and competition were discussed and analyzed based on the competing risk model. Results can be concluded that: a) people feel happy and meaningful during most of the activities, while they feel sad or pain in relatively rare occasions; b) there is no significant difference between young people and the elderly as for the total number of activities during one day; c) estimation results show that personal, household and activity characteristics have significant influence on activity duration and pattern, and the pattern of last activity (N) has a great influence on the occurrence of next activity (N+1); d) the competition between residents' daily activities is confirmed based on the competing risk model, and travel is closely related to various activities and can be seen as the derived demand of various activities. In all combinations of activity-travel chain schedule, personal - household (30.0%), household - recreation (25.9%), work - travel (45.2%), purchase - travel (33.7%), recreation - travel (22.5%), volunteer - travel (55.3%) and travel - purchase (28.4%) have the highest proportion respectively.

Short-Term Holiday Travel Demand Prediction for Urban Tour Transportation: A Combined Model Based on STC-LSTM Deep Learning Approach

Wanying Li,Hongzhi Guan,Yan Han,Haiyan Zhu,Ange Wang 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.9

Short-term prediction of holiday travel demand is a complex but key issue to the planning and management of tour transportation system in big cities. This paper develops an improved spatial and temporal correlation long short-term memory model (STC-LSTM) to forecast short-term holiday travel demand based on deep learning approach. Analysis results show six kinds of tourist flow correlations appears in different sets of tourist attractions, and 27.94 percent of the tourist attractions have mid- or high- positive tourist flow correlation with others, meaning that a positive synchronization mechanism exists between suburban tourist attractions in Beijing. The proposed model predicts the holiday travel demand on the basis of the historical data of the spatial and temporal related tourist flows, and the auxiliary data including meteorological data, temporal data, and Internet search index. Based on actual case study with tourist flow data of the suburban tourist attraction in Beijing, the proposed STC-LSTM is carried out to compared with other conventional prediction approaches. Results show that the proposed approach can improve the prediction accuracy and well capture the different spatial and temporal correlations of tourist flows.

Dynamics of high-speed train in crosswinds based on an air-train-track interaction model

Zhai, Wanming,Yang, Jizhong,Li, Zhen,Han, Haiyan Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.2

A numerical model for analyzing air-train-track interaction is proposed to investigate the dynamic behavior of a high-speed train running on a track in crosswinds. The model is composed of a train-track interaction model and a train-air interaction model. The train-track interaction model is built on the basis of the vehicle-track coupled dynamics theory. The train-air interaction model is developed based on the train aerodynamics, in which the Arbitrary Lagrangian-Eulerian (ALE) method is employed to deal with the dynamic boundary between the train and the air. Based on the air-train-track model, characteristics of flow structure around a high-speed train are described and the dynamic behavior of the high-speed train running on track in crosswinds is investigated. Results show that the dynamic indices of the head car are larger than those of other cars in crosswinds. From the viewpoint of dynamic safety evaluation, the running safety of the train in crosswinds is basically controlled by the head car. Compared with the generally used assessment indices of running safety such as the derailment coefficient and the wheel-load reduction ratio, the overturning coefficient will overestimate the running safety of a train on a track under crosswind condition. It is suggested to use the wheel-load reduction ratio and the lateral wheel-rail force as the dominant safety assessment indices when high-speed trains run in crosswinds.