Prediction of tectonic fractures in coal reservoirs using geomechanical method

Xiaolong Fu,Junsheng Dai,Jianwei Feng 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.4

Coalbed methane (CBM) resources are one of the most important and broadly developed unconventional resources. Considering the particularity of the coal, an adapted geomechanical method involving elastic-plastic deformation is badly needed to calculate the fracture parameters of the coal reservoir. Based on the rock mechanics experiments and three-dimensional μCT scan, the fracture evolution of coals can be summed up to initial compaction, propagation and coalescence stage. The microfractures will rapidly connect to each other when reaching 85% peak strength. Based on the plenty of measurement data, the relationship between fracture volume density and stress-strain of coals is established, and the acquisition of the quantitative geomechanical models made it possible to characterize fracture parameters after various tectonic movements under different stress state. Furtherly, the preparation of procedural language for the finite element (FE) simulation platform made it more popular and effective in the prediction of the generation of fractures and spatial distribution. The simulated results of No. 3 coal seam of Shizhuangbei area, both of the fracture density and direction, were in agreement with field observation results, which can be a compelling evidence for the effectiveness of the method.

Analysis of transient flow in a pump-turbine during the load rejection process

Xiaolong Fu,Deyou Li,Hongjie Wang,Guanghui Zhang,Zhenggui Li,Xianzhu Wei 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.5

The transient flow in pump-turbines during the load rejection process is very complex. However, few studies have been conducted on three-dimensional (3-D) numerical simulation. Hence, we simulated 3-D transient turbulent flow in a pump-turbine during the load rejection process using the calculation method of coupling the flow with the rotor motion of rigid body. To simulate the unsteady boundary conditions, the dynamic closing process of the guide vanes was simulated with the dynamic mesh technology. The boundary conditions at the spiral-casing inlet and the draft tube outlet were determined using the user defined functions (UDF) according to the experimental data. The numerical results of the rotational speeds show a good agreement with the experimental data. Then, the complex transient flow in the pump-turbine during the load rejection process was analyzed based on the numerical results. The results show that there are severe unsteady vortex flows in the vaneless space near the conditions under which the hydraulic torque on the runner equals to zero. When the pump-turbine operates into the maximum reverse discharge condition in the reverse pump operating process, the unsteady vortex flows in the vaneless space are instantaneously impacted into the region between the guide vanes and the stay vanes by the sudden reverse flows. The formation and development mechanism of the unsteady vortex flow in the vaneless space is associated with the distribution characteristic of the velocity field.

CDH17 nanobodies facilitate rapid imaging of gastric cancer and efficient delivery of immunotoxin

Jingbo Ma,Xiaolong Xu,Chunjin Fu,Peng Xia,Ming Tian,Liuhai Zheng,Kun Chen,Xiaolian Liu,Yilei Li,Le Yu,Qinchang Zhu,Yangyang Yu,Rongrong Fan,Haibo Jiang,Zhifen Li,Chuanbin Yang,Chengchao Xu,Ying Long,J 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: It is highly desirable to develop new therapeutic strategies for gastric cancer given the low survival rate despite improvement in the past decades. Cadherin 17 (CDH17) is a membrane protein highly expressed in cancers of digestive system. Nanobody represents a novel antibody format for cancer targeted imaging and drug delivery. Nanobody targeting CHD17 as an imaging probe and a delivery vehicle of toxin remains to be explored for its theragnostic potential in gastric cancer. Methods: Naïve nanobody phage library was screened against CDH17 Domain 1-3 and identified nanobodies were extensively characterized with various assays. Nanobodies labeled with imaging probe were tested in vitro and in vivo for gastric cancer detection. A CDH17 Nanobody fused with toxin PE38 was evaluated for gastric cancer inhibition in vitro and in vivo. Results: Two nanobodies (A1 and E8) against human CDH17 with high affinity and high specificity were successfully obtained. These nanobodies could specifically bind to CDH17 protein and CDH17-positive gastric cancer cells. E8 nanobody as a lead was extensively determined for tumor imaging and drug delivery. It could efficiently co-localize with CDH17-positive gastric cancer cells in zebrafish embryos and rapidly visualize the tumor mass in mice within 3 h when conjugated with imaging dyes. E8 nanobody fused with toxin PE38 showed excellent anti-tumor effect and remarkably improved the mice survival in cell-derived (CDX) and patient-derived xenograft (PDX) models. The immunotoxin also enhanced the anti-tumor effect of clinical drug 5-Fluorouracil. Conclusions: The study presents a novel imaging and drug delivery strategy by targeting CDH17. CDH17 nanobodybased immunotoxin is potentially a promising therapeutic modality for clinical translation against gastric cancer.

THE ALGORITHM OF DYNAMIC MEMORY BASED ON RESIDUAL ANTIGENFOR INTRUSION DETECTION

Haidong Fu,Xue Li,Jianxun Chen,Xiaolong Zhang 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

A novel dynamical memory algorithm is proposed based on residual antigen theory. The theory is used to formulate a view that the memory is dynamical. The model of multilayer defending system in Network Intrusion Detection is constructed according to the defending hierarchy of Human Immune System.The dynamical memory algorithm applied in Intrusion Detection System has been presented. Results from experiment indicated that the algorithm makes the dynamic and permanent of memory in the Intrusion Detection come true and improves the utilization of system resource.

Stress sensitivity in naturally fractured reservoirs: a case study of the Lower Cretaceous Xiagou Formation, Qingxi Oilfield, Jiuxi Basin, northwestern China

Wei Ju,Xiaolong Fu,Weifeng Sun,Haoran Xu,Shengyu Wang 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.3

Stress sensitivity is the variation of rock petrophysical parameters resulting from changes in effective stress. In fractured reservoirs, experimental methods exhibit a certain amount of error in the quantitative analysis of reservoir rock stress sensitivity. In addition, fracture-bearing experimental rock samples are difficult to obtain and prepare. Therefore, in the present study, reservoir rock stress sensitivity in naturally fractured reservoirs was investigated based on geomechanical modeling using a case study of the Lower Cretaceous Xiagou Formation in the Qingxi Oilfield. The results indicate that the Xiagou fractured reservoir experiences strong stress sensitivity with a fracture permeability damage rate reaching 94.38%. Natural fractures influence reservoir rock stress sensitivity. The degree of filling and type of filled minerals within natural fractures have great effects on the permeability damage rate. A higher permeability damage rate suggests stronger rock stress sensitivity. Generally, I) for reservoir rocks with unfilled natural fractures, the permeability damage rate is extremely high; II) for reservoir rocks with partially filled natural fractures, the permeability damage rate is high, and if the minerals within the natural fractures are insoluble, the permeability damage rate is slightly higher than if the materials are soluble; III) for reservoir rocks with completely filled natural fractures, the permeability damage rate is extremely low if the minerals within the natural fractures are insoluble; however, if the materials are soluble, the permeability becomes slightly higher with the increase of effective stress. Most importantly, this study provides a practical method for analyzing stress sensitivity in naturally fractured reservoirs.

Preparation and Performance of Road Micro-surfacing Materials with Exhaust Purification Function

Chaohui Wang,Hao Fu,Qian Chen,Xiaolong Sun,Tengteng Guo,Jin Guo 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Road micro-surfacing materials with exhaust purification function were developed to purify and alleviate serious air pollution in cities. Two types of functional materials satisfied the basic performance requirements of aggregates and fillers were selected to develop micro-surfacing materials with exhaust purification function. Test equipment for exhaust purification effect was invented, and test methods were proposed. The exhaust purification effect involved in functional micro-surfacing materials was comprehensively investigated. The road performance was also evaluated. Finally, the exhaust purification mechanism of functional micro-surfacing materials was revealed. Results showed that the purification rates of gaseous pollutants (COx, NOx, and SO2) and particulate pollutants (PM 2.5 and PM 10) were above 15% and 50%, respectively based on indoor heating and cooling intervals, and that of outdoors were 20% and 40%. The functional micro-surfacing materials exhibited satisfactory road performance. Moreover, the self-polarization effect of the functional materials contributed to the exhaust purification effect.

Aerodynamic Design of the Supersonic Aircraft Wing-Shape and Wing-Twist Optimization

Li Li,Junqiang Bai,Tongbiao Guo,Xiaolong He,Ziyuan Fu 한국항공우주학회 2018 International Journal of Aeronautical and Space Sc Vol.19 No.2

This paper builds an aerodynamic optimization design system by coupling the free form deformation parameterization technique,thedynamicmeshtechniquebasedoninversedistanceweightinginterpolationmethodandparticleswarmoptimization algorithm,Krigingsurrogatemodel,withthecomputationalfluiddynamicssolverbasedonReynolds-averagedNavier–Stokes equations. And it carries out aerodynamic optimization designs with a supersonic transport aircraft configuration. The wing shape is parameterized by defining 60 design variables and the wing twist is by four design variables. Meanwhile, the wing thickness constraints are considered. Afterwards, a single-point optimization design aiming at minimum of the supersonic cruise drag is conducted, and in order to consider the transonic cruise condition, a multipoint aerodynamic optimization design aiming at minimum of a weighted drag for the supersonic cruise drag and transonic cruise drag is performed. The analyses of optimization results illustrate the specific drag reduction, the characteristics of pressure distributions for both the supersonic cruise condition and transonic cruise condition, and how the shock wave region and strength have improved on thesupersoniccruisecondition.Theoptimizationdesignthispaperpresentsrealizingthedragreductionisquitepracticaland effective, which is instructive in supersonic aircraft design.

Selection and Validation of Reference Genes for Quantitative Real-Time PCR in Artemisia sphaerocephala Based on Transcriptome Sequence Data

Xiaowei Hu,Shuzhen Nan,Xiumei Miao,Yuanyuan Zhao,Guoqin Duan,Pengfang Yang,Xiaolong Chen,Lijing zhang,Hua Fu 한국초지조사료학회 2016 한국초지조사료학회 학술대회논문집 Vol.2016 No.08

The Effect of Enhanced UV-B Radiation and Drought on the Growth and Physiology in Artemisia sphaerocephala

Yuanyuan Zhao,Xiaowei Hu,Xiumei Miao,Shuzhen Nan,Guoqin Duan,Pengfang Yang,Xiaolong Chen,Lijing zhang,Hua Fu 한국초지조사료학회 2016 한국초지조사료학회 학술대회논문집 Vol.2016 No.08

The electrocatalysis of Mn-Co3O4/CeO2@C particles with different Ce content modified Ti/PbO2 anode and its application for copper electrodeposition

Yin Zihang,He Ruibo,Nie Fei,Wei Zhen,Jia Bo,Feng Qing,Fu Xiaolong,Zhang Wenyan 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

The oxygen evolution kinetics of industrial copper electrodeposition is slow, resulting in low electrocatalytic activity and high energy consumption. In this work, a quaternary composite of carbon coated active particles containing Mn, Co and Ce were prepared (Mn-Co3O4/CeO2@C), and Ti/Sb-SnO2/PbO2 electrode doped with these active particles was prepared by co-electrodeposition. The microstructure and chemical composition of the electrode was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). Linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and Tafel polarization curve (Tafel) were used to study the electrochemical properties of anode materials. The results showed that the doping of Mn-Co3O4/CeO2@C active particles promoted the crystal transition of PbO2, decreased the average grain size, and the doping of Ce increases the average valence state of Co. The modified titanium electrode showed excellent catalytic activity of the oxygen evolution reaction (OER) characteristics. The overpotential of the doped Ti/Sb-SnO2/PbO2 anode was only 453 mV when the current density was 20 mA cm−2 in 0.5 M H2SO4 solution, which is 508 mV lower than that of the undoped Ti/Sb-SnO2/PbO2 anode. In simulated copper electro-deposition experiments, the cell voltage was reduced by about 400 mV, compared to the undoped Ti/Sb-SnO2/PbO2 electrode.