Characterization of high-alumina coal fly ash based silicate material and its adsorption performance on volatile organic compound elimination

Guojun Yuan,Jianbin Zhang,Yongfeng Zhang,Yinan Yan,Xinxin Ju,Junmin Sun 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.3

A highly stable silicate material from high-alumina coal fly ash was prepared and characterized using X-raydiffraction, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermal analysis, Xrayphotoelectron spectroscopy, and elemental analysis. The spectral results show that the silicate material was mainlycomposed of six elements, C, Ca, O, Si, Mg, and Al, in the form of Ca2+, Mg2+, Al3+, SiO32−, and CO32− ions. Some adsorbedwater and/or water of crystallization was also observed. The silicate material showed exceptionally high capabilityto adsorb volatile organic compounds (VOCs). The results of dynamic adsorption behavior show that the silicatematerial presents similar properties with commercial activated carbon and stronger absorption properties than commercialdiatomite for the adsorption of VOCs. The FTIR spectral results show weak hydrogen bonding interactions ofthe silicate material with three VOCs.

Experimental study on seismic behavior of high strength reinforced concrete frame columns with high axial compression ratios

Zhang, Guojun,Liu, Boquan,Bai, Guoliang,Liu, Jianxin Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.33 No.5

Experimental study on seismic behavior of high strength reinforced concrete frame columns with high axial compression ratios

Guojun Zhang,Jianxin Liu,Guoliang Bai,Boquan Liu 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.33 No.5

Reduction of Energy Comsumptiuon and Thermal Deformation in WEDM by Magnetic Field Assisted Technology

Yanming Zhang,Zhen Zhang,Guojun Zhang,Wenyuan Li 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.2

Energy consumption and machining accuracy are considered to be two important attributes of performance indicators for green operations of wire electric discharge machining (WEDM). However, there is a paucity of studies that focus on the energy consumption and geometric error caused by thermal deformation. In this paper, a hybrid technique of WEDM with assisted magnetic field (MF) is proposed for enhancing machining performance to reduce energy consumption and thermal deformation. Based on the principles of thermal deformation, energy consumption, and magnetic field-assisted WEDM, a set of experiments is conducted to investigate thermal deformation and energy consumption of MF-assisted WEDM and conventional WEDM machining of Inconel 718. The effects of magnetic field on thermal deformation, discharge waveforms, surface integrity, and energy consumption are analyzed, and it is concluded that the proposed hybrid technique of MF-assisted WEDM offers numerous advantages and potential for applications in the green precision manufacturing field.

Petrogenesis of the late Mesozoic highly fractionated I-type granites in the Luanchuan district: implications for the tectono-magmatic evolution of eastern Qinling

Yunhui Zhang,Huawen Cao,Mo Xu,Shouting Zhang,Li Tang,Shiyan Wang,Qiuming Pei,Guojun Cai,Tong Shen 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.2

Late Mesozoic granites are extensively distributed in the Luanchuan district of eastern Qinling and can be divided into two types: Late Jurassic to Early Cretaceous granites (ore-related plutons) and Late Cretaceous granites (Laojunshan batholith). This study presents new geochemical and zircon U-Pb-Hf isotopic data from the Shibaogou and Yuku plutons to provide robust constraints on the petrogenesis and tectonic significance of the late Mesozoic granites in the Luanchuan district. Zircon U-Pb dating results yielded weighted mean 206Pb/238U ages of 149.1 ± 0.8 Ma and 150.5 ± 0.8 Ma, which were interpreted as the crystallization ages of the Shibaogou and Yuku plutons, respectively. We propose that the late Mesozoic granites contain high concentrations of SiO2 and alkali elements (Na2O + K2O) and feature metaluminous to weakly peraluminous characteristics. Enrichment in light rare earth elements and large ion lithophile elements and depletion in high field strength elements are observed. Mineralogical and geochemical evidence reveal that the late Mesozoic granites are highly fractionated I-type granites with fractional crystallization of feldspar, plagioclase and accessory minerals (e.g., apatite and titanite or magnetite). Based on the Hf composition, we suggest that the parental magmas of the ore-related plutons were derived from remelting of the Taihua and Xiong’er groups with minor contributions of mantle-derived materials and that the Laojunshan batholith was generated by the hybridization of ancient crust- (Kuanping group) and mantle-derived components. Collectively, the above arguments indicates a tectonic transition from compression to post-collisional extension during the late Mesozoic, that was likely triggered by the continental collision of the North China Block and the Yangtze Block, which generated numerous contemporaneous granites and Mo-W-Pb-Zn-Ag-Au poly-metallic deposits.

A brain somatic RHEB doublet mutation causes focal cortical dysplasia type II

Shanshan Zhao,Zhenghui Li,Muxian Zhang,Lingliang Zhang,Honghua Zheng,Jinhuan Ning,Yanyan Wang,Feng-Peng Wang,Xiaobin Zhang,Hexia Gan,Yuanqing Wang,Xian Zhang,Hong Luo,Guojun Bu,Huaxi Xu,Yi Yao,Yun-wu 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Focal cortical dysplasia type II (FCDII) is a cerebral cortex malformation characterized by local cortical structure disorganization, neuronal dysmorphology, and refractory epilepsy. Brain somatic mutations in several genes involved in the PI3K/AKT/mTOR pathway are associated with FCDII, but they are only found in a proportion of patients with FCDII. The genetic causes underlying the development FCDII in other patients remain unclear. Here, we carried out whole exome sequencing and targeted sequencing in paired brain–blood DNA from patients with FCDII and identified a brain somatic doublet mutation c.(A104T, C105A) in the Ras homolog, mTORC1 binding (RHEB) gene, which led to the RHEB p.Y35L mutation in one patient with FCDII. This RHEB mutation carrier had a dramatic increase of ribosomal protein S6 phosphorylation, indicating mTOR activation in the region of the brain lesion. The RHEB p.Y35L mutant protein had increased GTPλS-binding activity compared with wild-type RHEB. Overexpression of the RHEB p. Y35L variant in cultured cells also resulted in elevated S6 phosphorylation compared to wild-type RHEB. Importantly, in utero electroporation of the RHEB p.Y35L variant in mice induced S6 phosphorylation, cytomegalic neurons, dysregulated neuron migration, abnormal electroencephalogram, and seizures, all of which are found in patients with FCDII. Rapamycin treatment rescued abnormal electroencephalograms and alleviated seizures in these mice. These results demonstrate that brain somatic mutations in RHEB are also responsible for the pathogenesis of FCDII, indicating that aberrant activation of mTOR signaling is a primary driver and potential drug target for FCDII.

Research on Navigation-aids Information System

Zhang XingGu,Peng GuoJun,Xiang Lu,Chen Xin 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.2006 No.-

This thesis researches on the application of computer, modern communication, GIS, GPS, AIS and World-Wide-Web in the field of navigation-aids information system, and has realized an integrated system consisted of navigation-aids information GIS platform, navigation-aids monitoring system and navigation-aids information distribution system. This system has strong integration capability, and has realized navigation-aids information distribution based on WEBGIS at the first time. It strongly promotes navigation-aids daily management and maintenance, and this system provides technique guarantee for ships and marine departments to acquire navigation-aids information in time, by rule and line expediently.

Durable corrosion resistant and hot water repellent superhydrophobic bilayer coating based on fluorine-free chemicals

Binbin Zhang,Mengying Qiao,Guojun Ji,Baorong Hou 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.119 No.-

Due to their unique interface functions, superhydrophobic materials have a wide range of applications. However, the majority of current superhydrophobic surfaces are designed and manufactured using fluorinatedchemical reagents. Moreover, high temperature water droplets with lower surface tension easilypinning to the surface, resulting in interfacial property failures. To overcome these deficiencies, herein wefabricated a superhydrophobic bilayer coating on Q235 carbon steel based on fluorine-free chemicals ofpolydimethylsiloxane (PDMS) and hexadecyltrimethoxysilane modified aluminum oxide nanoparticles(Al2O3@HDTMS). Field-emission scanning electron microscopy (FE-SEM), Energy dispersive spectroscopy(EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Contactangle meter, and Electrochemical impedance spectroscopy (EIS) techniques were utilized to characterizethe constructed superhydrophobic bilayer coating. The results show that the superhydrophobic bilayercoating exhibits non-wetting, anti-fouling and self-cleaning capacities towards various solid and liquidpollutants. The superhydrophobic bilayer coating possesses superior anti-corrosion and weather resistingproperties with |Z|0.01Hz and Rct values increased by more than eight orders of magnitude, withstanding720 h accelerated salt-spray and 50 days outdoor atmospheric corrosion attack. Furthermore, the superhydrophobicbilayer coating features super-repellency towards water droplets in a wide temperaturerange (30 90 C) and accompanied with high mechanical stability against continuous sandpaper abrasionand tape-peeling cycles.

Fractal Random Walk and Classification of ECG Signal

Daoming Zhang,Guojun Tan,Jifei Hao 보안공학연구지원센터 2008 International Journal of Hybrid Information Techno Vol.1 No.1

This paper presents a new nonlinear method to analyze ventricular arrhythmia(VA) and sinus rhythms(SR). The problem is introduced from the discussion of Fractal Random Walk characteristics of ECG signal. Further, the fractal analysis is used to distinguish ventricular flutter(VFL), ventricular fibrillation(VF), ventricular tachycardia(VT)) and sinus rhythms(SR) from the raw electrocardiogram(ECG) data. The method has a three step processing. First, calculating the slope of permutation entropy(PE) to detect the onset of ventricular arrhythmia; Second, using regularization dimension(RD) to classify SR, VFL and VT/VF; Finally, according to multifractal spectrum(MS) area to distinguish VT and VF. Four databases are used to detect the method, and the accuracy of every step is 93.33%, 100% and 98%. As a whole, the accuracy of detecting onset of ventricular arrhythmia and confirming which ventricular arrhythmia is, is VFL 93.33%, VT and VF 91.47%.

Engineering Properties and Microstructural Characteristics of Foundation Silt Stabilized By Lignin-based Industrial By-product

Tao Zhang,Guojun Cai,Songyu Liu,Anand J. Puppala 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.7

This paper presents details of a study that deals with determination of engineering properties and microstructural characteristics of a foundation soil (silt) sedimented in Jiangsu Province of China when it is stabilized by lignin-based industrial by-product. A series of laboratory tests were carried out with respect to evaluate the effect of lignin content and curing time on the overall soil properties including Atterberg limits, pH, unconfined compressive strength, stress-strain characteristics, secant modulus, and California bearing ratio. In addition, scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry studies were conducted to understand the microstructural characteristics and stabilization mechanism of the stabilized silt. The results reveal that lignin has a great potential to improve engineering properties of silt and shows a promising prospect as a new environmentally friendly soil stabilizer. Curing time and lignin content have significant influence on the basic engineering properties and microstructural characteristics of the lignin stabilized silt. The optimum content of lignin for foundation silt in Jiangsu Province of China is approximately 12%. The precipitated cementing material is formed after stabilization of lignin with a period of curing. The stabilized silt switches over its response from a brittle to ductile material in the presence of lignin. Peak analysis results of the pore-size distribution curves demonstrates that the lignin stabilized silt exhibits bimodal behavior when the lignin content less than 8%, whereas it displays unimodal type when the lignin content is more than or equal to 8%. These observations provide enhanced understanding of lignin-based industrial by-product as a soil stabilizer at the foundation construction.