CO2 storage capacity of anthracite coal in deep burial depth conditions and its potential uncertainty analysis: a case study of the No. 3 coal seam in the Zhengzhuang Block in Qinshui Basin, China

Hongjie Xu,Shuxun Sang,Jingfen Yang,Huihu Liu 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.5

The storage of CO2 in deep unminable coal seams can mitigate greenhouse gas emissions. However, CO2 storage in deep anthracite coal is complex with some uncertainties in the estimation of CO2 storage capacity. Based on isothermal adsorption experiments and gas solubility experiments under high temperature and pressure conditions, the total storage capacity of CO2 in anthracite coal is discussed. The results show that the absolute adsorption amount is over 44 cm3/g at temperatures of 318.15, 335.65, and 353.15 K as well as adsorption equilibrium pressures of 10 MPa. The storage capacity of adsorbed and free gas is 35–70 cm3/g and 5–8 cm3/g, respectively, within a depth range of 1000–2000 m. The soluble gas can be ignored for its low content between 0.22 cm3/g and 0.28 cm3/g with a proportion of less than 1%. The storage capacity of CO2 may be estimated inaccurately because of the heterogeneity and uncertainty of the macroscopic geological conditions and coal reservoir parameters. Taking the No. 3 coal seam in Zhengzhuang block as an example, the storage priority area was divided into supercritical area and subcritical area with five sub-areas according to storage conditions, and the storage capacity was calculated, showing a relatively good storage potential.

Histone lysine demethylases in mammalian embryonic development

Hongjie Shen,Wenqi Xu,Fei Lan 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Post-translational modifications, such as methylation, acetylation and phosphorylation, of histone proteins play important roles in regulating dynamic chromatin structure. Histone demethylation has become one of the most active research areas of epigenetics in the past decade. To date, with the exception of histone H3 lysine 79 methylation, the demethylases for all major lysine methylation sites have been discovered. These enzymes have been shown to be involved in various biological processes, with embryonic development being an exciting emerging area. This review will primarily discuss the involvement of these demethylases in the regulation of mammalian embryonic development, including their roles in embryonic stem cell pluripotency, primordial germ cell (PGC) formation and maternal-to-zygotic transition.

Robust Stochastic Sampled-data-based Output Consensus of Heterogeneous Multi-agent Systems Subject to Random DoS Attack: A Markovian Jumping System Approach

Hongjie Ni,Zhenhua Xu,Jun Cheng,Dan Zhang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7

This paper addresses the robust stochastic sampled-data-based output feedback (SSDBOF) consensuscontroller design for a network of continuous-time heterogeneous multi-agent systems (MASs) in the presence ofdenial-of-service (DoS) attack. Under the mild assumption that the sampling instant is stochastically triggered andsatisfies the Markov property, a homogeneous Markovian jump system (MJS) method is introduced that is capable ofmodeling the stochastic sampled-data-based control system. Furthermore, the randomly occurring Deny-of-Service(DoS) attack problem is also taken into account due to the existence of potential adversary that tries to block thecommunication channels. A novel discrete-time stochastic Markovian system model is first introduced that enablesus to deal with the stochastic sampling and random DoS attack phenomena in a unified framework. Then byadopting the decoupling scheme, some sufficient conditions are proposed such that all the outputs of the followingagents can track the output of the leading agent, and the prescribed H∞ performance level is also guaranteed. Inour work, the SSDBOF consensus controller design method is transformed to a feasibility problem subject to thelinear matrix inequality (LMI) constraints. The theoretical results are finally applied to solve the position trackingproblem of a network of vehicle systems

A Novel Fluorescent Nanoswitch Based on Carbon Dots for Sensitive Detection of Hg2+ and I-

Xiqing Liu,Xiao Wei,Yeqing Xu,Hongji Li,Kai Lu,Kun Wang,Yongsheng Yan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.2

In this paper, a novel fluorescent nanoswitch based on carbon dots (CDs) was developed for the sensitive and selective determination of Hg2+ and I-. The CDs were obtained by simple hydrothermal process and had a strong fluorescence emission at 440 nm. The fluorescence of the CDs can be selectively quenched by Hg2+ ion, and then the I- was added into the system, which can interact with Hg2+ and recover fluorescence of the CDs. Under optimal conditions, the quenching fluorescence intensity on addition of Hg2+ has obtained a satisfactory linear relationship covering the linear range of 0–50 µM with the linear relationship (R21 = 0.9991), and the limit of detection is 0.047 µM. The additions of I- could lead to the fluorescence intensity of the solution of CDs and Hg2+ (50 µM) recover rapidly, which is linearly related (R22 = 0.9957) to the concentration of I- in the range from 0 to 70 µM, the detection limit for I- was calculated to be 0.084 µM. Moreover, the developed method to detect Hg2+ and I- was evaluated in real examples, and the fluorescence switching can sensitively and selectively detect Hg2+ and I- over some potentially interfering ions, the recoveries were up to 97.8–107.0% and 96.7–106.6%, respectively.

Uncertainty analysis of heat transfer of TMSR-SF0 simulator

Jiajun Wang,Ye Dai,Yang Zou,Hongjie Xu Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.2

The TMSR-SF0 simulator is an integral effect thermal-hydraulic experimental system for the development of thorium molten salt reactor (TMSR) program in China. The simulator has two heat transport loops with liquid FLiNaK. In literature, the 95% level confidence uncertainties of the thermophysical properties of FLiNaK are recommended, and the uncertainties of density, heat capacity, thermal conductivity and viscosity are ±2%, ±10, ±10% and ±10% respectively. In order to investigate the effects of thermophysical properties uncertainties on the molten salt heat transport system, the uncertainty and sensitivity analysis of the heat transfer characteristics of the simulator system are carried out on a RELAP5 model. The uncertainties of thermophysical properties are incorporated in simulation model and the Monte Carlo sampling method is used to propagate the input uncertainties through the model. The simulation results indicate that the uncertainty propagated to core outlet temperature is about ±10 ℃ with a confidence level of 95% in a steady-state operation condition. The result should be noted in the design, operation and code validation of molten salt reactor. In addition, more experimental data is necessary for quantifying the uncertainty of thermophysical properties of molten salts.

Development of TREND dynamics code for molten salt reactors

Yu, Wen,Ruan, Jian,He, Long,Kendrick, James,Zou, Yang,Xu, Hongjie Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.2

The Molten Salt Reactor (MSR), one of the six advanced reactor types of the 4th generation nuclear energy systems, has many impressive features including economic advantages, inherent safety and nuclear non-proliferation. This paper introduces a system analysis code named TREND, which is developed and used for the steady and transient simulation of MSRs. The TREND code calculates the distributions of pressure, velocity and temperature of single-phase flows by solving the conservation equations of mass, momentum and energy, along with a fluid state equation. Heat structures coupled with the fluid dynamics model is sufficient to meet the demands of modeling MSR system-level thermal-hydraulics. The core power is based on the point reactor neutron kinetics model calculated by the typical Runge-Kutta method. An incremental PID controller is inserted to adjust the operation behaviors. The verification and validation of the TREND code have been carried out in two aspects: detailed code-to-code comparison with established thermal-hydraulic system codes such as RELAP5, and validation with the experimental data from MSRE and the CIET facility (the University of California, Berkeley's Compact Integral Effects Test facility).The results indicate that TREND can be used in analyzing the transient behaviors of MSRs and will be improved by validating with more experimental results with the support of SINAP.

Detecting small lung tumors in mouse models by refractive-index microradiology

Chien, Chia-Chi,Zhang, Guilin,Hwu, Y.,Liu, Ping,Yue, Weisheng,Sun, Jianqi,Li, Yan,Xue, Hongjie,Xu, Lisa X.,Wang, Chang Hai,Chen, Nanyow,Lu, Chien Hung,Lee, Ting-Kuo,Yang, Yuh-Cheng,Lu, Yen-Ta,Ching, Y Springer-Verlag 2011 ANALYTICAL AND BIOANALYTICAL CHEMISTRY Vol.401 No.3