Fuzhou UniversityFujian

Fuzhou, China

Fuzhou UniversityFujian

Fuzhou, China
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Fang Q.,Fuzhou UniversityFujian | Dong Y.,Fuzhou UniversityFujian | Chen Y.,Fuzhou UniversityFujian | Lu C.-H.,Fuzhou UniversityFujian | And 3 more authors.
Carbon | Year: 2017

Carbon based dots (CDs) have attracted broad attention exhibit due to the unique optical properties. However, the exact origins of their optical properties are still controversial. Citric acid (CA) coupled with some amino group-containing small molecules are believed to be ideal precursors for the synthesis of high luminescent CDs through various thermal treatment processes. Herein, CA coupled with four amino group-containing small molecules are chosen as models to synthesize CDs for a systematical study on the photoluminesce (PL) properties. It is found that the PL properties of CDs are resulted from the synergistic effect of the contained luminescent pyridine-derivatives and the defect states. A reasonable mechanism of PL emission from the CDs has been proposed. The results presented here must be critical for understanding the origins of PL, and also for preparing CDs with strong and wavelength tunable PL emission. © 2017 Elsevier Ltd

Xu W.,Fuzhou UniversityFujian | Chen Q.,Fuzhou UniversityFujian | Ge Q.,Fuzhou UniversityFujian
Desalination | Year: 2017

Forward osmosis (FO) has been developing rapidly in recent years and demonstrated its advantages in various applications. However, challenges from reverse solute diffusion, concentration polarization and membrane fouling are still extensively present in FO processes. To alleviate these problems, considerable efforts have been made in exploring appropriate FO membranes. Chemical modification on ready-made membranes has become an important method in novel FO membrane exploration in recent years. This paper focuses on the progress of FO membranes obtained specially from chemical modifications. First of all, an overview of FO membrane related to membrane materials and chemical modification approaches is provided. The strengths and weaknesses of the chemical modification methods are assessed. Then, typical FO applications promoted by the chemically modified FO membranes are exemplified. Finally, challenges and future directions of chemical modification approaches in exploring novel FO membranes are highlighted. This review may provide new insights into the future advancement of both FO membrane and FO technology. © 2017 Elsevier B.V.

Shi J.,Fuzhou UniversityFujian | Cui K.,Fuzhou UniversityFujian | Wang B.,Fuzhou UniversityFujian | Deng L.,Fuzhou UniversityFujian | And 3 more authors.
Materials Characterization | Year: 2017

The effects of twin types on grain nucleation and texture evolution during static recrystallization were investigated. Three kinds of cylindrical samples were cut from an AZ31 magnesium alloy plate with their compression directions aligned 0°, 45°, and 90° to the normal direction (ND), and they were referred as 0ND, 45ND and 90ND samples, respectively. The compression tests were conducted at room temperature with a strain of 16%, followed by an annealing at 250 °C for 3 min, 20 min and 60 min respectively. The effects of twin types in different samples on grain nucleation and texture evolution during static recrystallization were investigated with electron backscattered diffraction (EBSD) technology. The {10 − 11} − {10 − 12} double twinning was found to be the dominant deformation mechanism in 0ND and 90ND samples, while {10–12} tension twins and compression twins can be observed in some grains in 45ND sample. The {10–11} − {10–12} double twins are the preferred sites for new grain nucleation, and the {10–12} tensile twins are unfavorable for nucleation of static recrystallization. It is noteworthy that a tiny fraction of {10–11} and {10 − 13} compression twins can be nucleation sites for new grains. The sequence of recrystallized speed in the samples is: 90ND sample > 0ND sample > 45ND sample. The grain size can be refined effectively and the deformation texture becomes weaken during the static recrystallization. The misorientation angle between recrystallized grains and matrix is fluctuated from 20° to 60°, and this phenomenon is suggested to be related to the {10–11} − {10–12} double twins, {10–11} and {10–13} compression twins. © 2017 Elsevier Inc.

Chen Y.,Fuzhou UniversityFujian | Shang P.,Fuzhou UniversityFujian | Dong Y.,Fuzhou UniversityFujian | Chi Y.,Fuzhou UniversityFujian
Sensors and Actuators, B: Chemical | Year: 2017

Carbon-based dots (CDs) exhibiting excellent fluorescence (FL) properties have been well applied in sensing. In particular, many FL sensors based CDs have been developed for various metal ions. However, the sensors based on the CDs without special functionalization usually show poor selectivity and sensitivity. In this work, cobalt(II) ion (Co2+) is taken as the model to introduce a novel, sensitive and selective FL sensing mode for metal ions based on CDs without special functionalization. A kind of highly luminescent nitrogen and sulfur co-doped CDs (N,S-CDs) are used as the probes. The FL signal of N,S-CDs is insensitive to Co2+ itself, but is quenched sensitively and selectively by Co2+ in the presence of cysteamine. Actually, cysteamine reacts with Co2+ to form a positively charged and absorbent complex (Co(cys)3 2+), whose absorption band covers completely the emission spectrum of N,S-CDs. Then, a FL resonance energy transfer (FRET) system is formed, in which N,S-CDs act as the donor and Co(cys)3 2+ acts as the acceptor. Furthermore, the electrostatic interaction between the positivity charged Co(cys)3 2+ and the negatively charged N,S-CDs increases the collision, enhancing the FRET effects. As a result, the FL signal of N,S-CDs can be dynamically quenched by Co(cys)3 2+. Finally, a sensitive and selective FL sensor is developed for Co2+. More importantly, this paper provides CDs a novel FL sensing mode, which may be applied in many other metal ions. © 2016

Peng K.-P.,Fuzhou UniversityFujian | Mou X.-P.,Fujian Inspection and Research Institute for Product Quality | Ma Y.-S.,Fujian Qianda Heavy Machinery Co LtdFujian
Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment | Year: 2014

Cu-35Zn alloy deformed by constrained groove pressing (CGP) up to 10 passes and 30% cold rolling was annealed at different temperatures. The thermal stability of Cu-35Zn processed by CGP and cold rolling was studied. The results show that the grains of Cu-35Zn alloy are refined by CGP and cold rolling. After the deformation of CGP and cold rolling, the hardness and strength of the samples are improved. The recovery process of specimens deformed by CGP and cold rolling is dominants when annealing below 200 ℃. The crystallites with large angle grain boundary are formed at 220 ℃. The recrystallization and grain growth are completed at 300-400 ℃.

Huang F.,Tongji University | Huang F.,Fuzhou UniversityFujian | Huang F.,University of Nevada, Reno | Yu X.,Fuzhou UniversityFujian | And 3 more authors.
Thin-Walled Structures | Year: 2016

In general, the calculation of ultimate load capacity (UL) of a concrete-filled steel tubular (CFST) column is based on the assumption that the load is resisted by both the steel tube and the concrete core simultaneously as a composite member. However, steel tubes of CFST columns are preloaded due to self-weight, wet concrete weight as well as temporary construction loads before the composite action is formed. There is still no consensus on how the preload affects the loading resistance of CFST columns and how to quantify the effect of preload on the ultimate strength. The paper reported an experimental study on circular CFST columns subjected to preload. The testing results showed that the preloading effect increased with the increase of slenderness, decreased the ultimate load capacity and increased the deformation significantly at high preloading ratio, but did not have much influence on the ultimate load capacity at light preload. Then, a parametric analysis of coupled effects of preloading ratio with other parameters, such as slenderness ratio, eccentric ratio, as well as material properties, is presented. Finally, a simplified method is proposed to predict the ultimate load capacity of CFST columns with preload. The preloading reduction factor of simplified methods of UL based on regressive analysis can be used to evaluate the UL of CFST columns with preload after verified by overall comparison of total preloading tests. © 2015 Elsevier Ltd. All rights reserved.

Dong H.,Fuzhou UniversityFujian | Sun H.,Fuzhou UniversityFujian | Zheng J.,Fujian Provincial HospitalFujian
Talanta | Year: 2016

With the development of large-scale biologic databases, precision medicine is becoming a frontier in biomedical research. As a main focus of precision medicine study, cancer has been widely accepted as a disease born out of inherited genetic variations or accumulating genomic damage. At the single-cell level, microfluidics or lab-on-a-chip technology for cancer study is an emerging tool for improving risk assessment, diagnostic categories and therapeutic strategies. This work presents a multi-layer microchip for single-cell gene expression profiling. Treated by three drug reagents (i.e. methyl methanesulfonate, docetaxel and colchicine) with varied concentrations and time lengths, individual human breast cancer cells (MCF-7) are then lysed on-chip, and the released mRNA templates are captured and reversely transcribed into cDNA on microbead surface. Three genes (GAPDH, CDKN1A, AURKA) are amplified and quantified simultaneously through triplex real-time polymerase chain reactions (qPCR). Readout per run is set to be eighteen, and can be further improved following same approach. The microchip is able to integrate all steps of single-cell gene expression profiling, and provide precision study of drug induced genotoxicity with reduced reagents consumption per reaction and instrumental cost. © 2016 Elsevier B.V.

Wang B.,Fuzhou UniversityFujian | Deng L.,Fuzhou UniversityFujian | Adrien C.,Chongqing University | Guo N.,Chongqing University | And 2 more authors.
Materials Characterization | Year: 2015

The effects of initial texture on the flow behavior, microstructure and texture evolution of Mg-3Al-1Zn alloy hot rolled plate with a strong basal texture during tension at room temperature have been investigated by experiments and simulations. Three kinds of specimens were cut from this plate with their tensile directions aligned 0°, 45°, and 90° to the normal direction (ND), and they were referred as 0ND, 45ND and 90ND specimens, respectively. A crystal plasticity model was developed to demonstrate the relationship between textures and deformation modes. The results show that the general features of flow curves and texture evolutions of AZ31 alloy during tension can be well explained by the relative activities of deformation modes, which exhibit a pronounced orientation dependence on both the starting and current textures. The obvious yielding behaviors in 0ND and 45ND specimens are induced by the initial activity of {10-12} twinning, and the strain hardening behavior is related to the activities of {10-12} twinning, basal slip and prismatic slip. Due to the existence of {10-11} twinning at low strain, the elongation to rupture of 90ND specimen is much lower than those the elongation of 0ND and 45ND specimens. Although prismatic slip activity depends on the initial texture, its activities always increases during tension, affecting the flow curves, microstructure and texture evolutions. The high prismatic slip activities in 0ND and 90ND specimens result in a strong {10-10} prismatic texture, while the activity of pyramidal < c + a > slip is always negligible in all specimens and insensitive to the initial texture during tension. © 2015 Elsevier Inc. All rights reserved.

Dong H.,Fuzhou UniversityFujian | Sun H.,Fuzhou UniversityFujian
Sensors (Switzerland) | Year: 2016

Microfluidics-based single-cell study is an emerging approach in personalized treatment or precision medicine studies. Single-cell gene expression holds a potential to provide treatment selections with maximized efficacy to help cancer patients based on a genetic understanding of their disease. This work presents a multi-layer microchip for single-cell multiplexed gene expression profiling and genotoxicity detection. Treated by three drug reagents (i.e., methyl methanesulfonate, docetaxel and colchicine) with varied concentrations and time lengths, individual human cancer cells (MDA-MB-231) are lysed on-chip, and the released mRNA templates are captured and reversely transcribed into single strand DNA. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), cyclin-dependent kinase inhibitor 1A (CDKN1A), and aurora kinase A (AURKA) genes from single cells are amplified and real-time quantified through multiplex polymerase chain reaction. The microchip is capable of integrating all steps of single-cell multiplexed gene expression profiling, and providing precision detection of drug induced genotoxic stress. Throughput has been set to be 18, and can be further increased following the same approach. Numerical simulation of on-chip single cell trapping and heat transfer has been employed to evaluate the chip design and operation. © 2016 by the author; licensee MDPI, Basel, Switzerland.

Dong Y.,Fuzhou UniversityFujian | Wu H.,Fuzhou UniversityFujian | Shang P.,Fuzhou UniversityFujian | Zeng X.,Fuzhou UniversityFujian | Chi Y.,Fuzhou UniversityFujian
Nanoscale | Year: 2015

Hydrazide-modified graphene quantum dots (HM-GQDs) obtained by refluxing GQDs with hydrazine hydrate were hybridized with gold nanoparticles (AuNPs) through a redox reaction between HM-GQDs and AuCl4 -. The obtained nano-hybrids (HM-GQD-AuNPs) possess the unique electrochemiluminescence (ECL) properties of HM-GQDs and the easy self-assembly with some bio-molecules of AuNPs, which have great potential applications in bio-sensors. HM-GQD-AuNPs were modified on a glassy carbon electrode to develop a novel ECL immunosensor of carcinoembryonic antigen (CEA) as a model target analyte. Due to the increment of electron-transfer resistance after immunoreaction, the ECL intensity decreased as the concentration of CEA was increased. The linear response range was between 0.02 and 80 ng mL-1, and the detection limit was 0.01 ng mL-1. © The Royal Society of Chemistry.

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