Sulfonated polysulfone proton exchange membrane with flexible side chains for fuel cells

Zongwen Qiao,Jiaqi Deng,Tao Chen 한국고분자학회 2024 Macromolecular Research Vol.32 No.2

In this study, chloromethylated polysulfones (CPS) were used as precursors to synthesize two kinds of sulfonated polysulfones with flexible side chains, namely PS-BS (The end of the side chain contains a sulfonic acid group) and PS-BDS (The end of the side chain contains two sulfonic acid groups). This was achieved through nucleophilic substitution reaction using sodium 4-hydroxybenzenesulfonate and disodium 1,2-dihydroxybenzene-3,5-disufonate as nucleophilic reagents, respectively. The chemical structures of the resulting sulfonated polysulfones were characterized using the Fourier infrared spectrum (FT-IR) and nuclear magnetic hydrogen spectrum ( H1-NMR). The proton exchange membranes (PEMs) were fabricated using a solution casting method. Thermogravimetric analysis (TGA) analysis revealed that the obtained PEMs exhibited stability up to 270 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis indicated that PS-BS and PS-BDS PEMs exhibited a clear microphase separation structure, with the hydrophilic sulfonic acid groups located far away from the hydrophobic main chain of PS. This unique structure contributed to improved dimensional stability and oxidative stability of the PEMs. The obtained PEMs show better dimensional stability and oxidative stability. Comparing the two types of PEMs at the same temperature and ion exchange capacity (IEC), PS-BDS PEMs demonstrate better dimensional stability and lower methanol permeability compared to PS-BS PEMs. For instance, PD-BDS-4 PEMs exhibited a dimensional of stability up to 8.6% at room temperature and 30% at 85 °C. The corresponding methanol permeability was 10.29 × 10– 7 cm2/ s at 25 °C, which was significantly lower than that of Nafion112 (10.5 × 10– 7 cm2/ s) PEMs under the same condition.

Magnetic Nanoclusters for Ultrasensitive Magnetophoretic Assays

Jin, Zongwen,Hahn, Young Ki,Oh, Eunkeu,Kim, Young-Pil,Park, Je-Kyun,Moon, Seung Ho,Jang, Jung-Tak,Cheon, Jinwoo,Kim, Hak-Sung WILEY-VCH Verlag 2009 Small Vol.5 No.20

<B>Graphic Abstract</B> <P>Magnetic nanoclusters (MNCs) are developed and used for an ultrasensitive magnetophoretic assay system. Prostate-specific antigen (PSA) is used as a target analyte (see image). The deflection velocity of a microbead is well correlated with the PSA concentration, with a detection limit of 45 fg mL<SUP>−1</SUP>, and this value is three orders of magnitude higher than conventional ELISA. The developed assay format is expected to be effectively applied to the detection of a target analyte with low abundance. <img src='wiley_img/16136810-2009-5-20-SMLL200900311-content.gif' alt='wiley_img/16136810-2009-5-20-SMLL200900311-content'> </P>

Recent change in agricultural trends and PGR activities in China

Zhang Zongwen 한국작물학회 2007 한국작물학회 학술발표대회 논문집 Vol.2007 No.11

China is an agricultural country with a large proportion of rural population. With the transition from a planned to a market-oriented rural economy, the accomplishments in agriculture were remarkable in the country in last decades. It is the fact that land holdings are very small in China and a large number of labours are shifting from rural areas to the urban areas. With the goals to meet the nation's food needs and poverty reduction for the huge population, China is facing challenges in the way of raising the income of rural people and sustainable development in agriculture. Farmers currently gain benefits from the new policies on rural reform, which has played critical role in the success of sustained rural development. The strategies for harmonizing the development between rural and urban areas being implemented will help to generate more developmental opportunities for rural communities. The researches on science and technology in agriculture have progressed dramatically in China. The hybrid rice is a remarkable achievement by Chinese scientists, which not only contributes to the food security in China, but also the whole world. The relevant organizations play a significant role in improving sciences and technologies among farmers by bringing advanced knowledge to the countryside and to every rural household. Currently, many programmes are going on for promoting economic construction in rural areas. Plant genetic resources are critical for meeting the goals of agricultural development in China. In last many years, Chinese government gave high priority to conservation and use of plant genetic resources. The national plant genetic resources management system is very complicated and usually operated by several relevant ministries, the State Forestry Administration for forest genetic resources programme, the Ministry of Health and the State Administration of Traditional Medicine for the medicinal plant genetic resources programme, and the Ministry of Agriculture for the crop genetic resources programme. China has set up the national ex situ conservation system composed of long-term genebank, mid-term genebank and field genebank. About 390 thousand accessions have been stored in these genebanks. Characterization and evaluation were carried out for most of agronomic characters. Useful materials were identified and distributed to breeders and other users. Documentation system on crop genetic resources was well developed. For future, the efforts will be made to promote the safeguard of the existing collections, including wild relatives of crops. The use of crop genetic resources in improvement programmes should be the ultimate objective of all undertaking activities in the country. The researches on plant genetic resources will be advanced through the activities on analyzing the genetic diversity, identifying genepools, mining useful genes, and promoting the access to genetic materials.

Increase in the detection sensitivity of a lateral flow assay for a cardiac marker by oriented immobilization of antibody

유이슬,Zongwen Jin,강문석,김학성 한국바이오칩학회 2011 BioChip Journal Vol.5 No.3

Early detection of human cardiac markers is regarded as a gold standard for diagnosis of acute myocardial infarction (AMI). Here we demonstrate the increase in the detection sensitivity of a lateral flow assay for a cardiac marker troponin I (cTnI) by oriented immobilization of antibodies on magnetic beads. For the construction of sensitive magnetic labels, orientated-immobilization of anti-troponin I antibodies on magnetic beads was attempted using protein G. Magnetic beads were first conjugated with protein G followed by immobilization of anti-cTnI antibodies. The factors affecting the detection sensitivity in the lateral flow assay system were investigated. The lateral flow assay of cTnI was carried out using the magnetic beads and a Giant magnetoresistive (GMR) sensor at the optimized conditions, and compared the results with using a conventional random immobilization method. Magnetic labels with oriented immobilization of antibodies enabled the detection of cTnI up to 0.01 ng/mL, showing significantly increased sensitivity compared with conventional immobilization method. This result clearly shows that the magnetic labels with oriented immobilization of antibodies can find wide applications in the lateral flow assays of target analytes.

A Novel Cross-Layer Dynamic Integrated Priority-Computing Scheme for 3G+ Systems

Weidong Wang,Zongwen Wang,Xinlei Zhao,Yinghai Zhang,Yao Zhou 한국통신학회 2012 Journal of communications and networks Vol.14 No.1

As Internet protocol and wireless communications have developed, the number of different types of mobile services has increased gradually. Existing priority-computing schemes cannot satisfy the dynamic requirements of supporting multiple services in future wireless communication systems, because the currently used factors, mainly user priority, are relatively simple and lack relevancy. To solve this problem and provide the desired complexity,dynamic behavior, and fairness features of 3G and beyond 3G mobile communication systems, this paper proposes a novel crosslayer dynamic integrated priority-computing scheme that computes the priority based on a variety of factors, including quality of service requirements, subscriber call types, waiting time, movement mode, and traffic load from the corresponding layers. It is observed from simulation results that the proposed dynamic integrated priority scheme provides enhanced performance.

Coating of Enzymes and Magnetic Nanoparticles on Carbon Nanotubes for High Performance Electrochemical Immunoassay based on Substrate Recycling

Yunxian PIAO,Zongwen JIN,Dohoon LEE,Hyejin LEE,Hyun-Bin NA,Taeghwan HYEON,Min-Kyu OH,Jungbae KIM,Hak-Sung KIM 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.10

A dependent stress–strength interference model based on mixed copula function

Jianxiong Gao,Zongwen An,Bo Liu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.10

In the traditional Stress–strength interference (SSI) model, stress and strength must satisfy the basic assumption of mutual independence. However, a complex dependence between stress and strength exists in practical engineering. To evaluate structural reliability under the case that stress and strength are dependent, a mixed copula function is introduced to a new dependent SSI model. This model can fully characterize the dependence between stress and strength. The residual square sum method and genetic algorithm are also used to estimate the unknown parameters of the model. Finally, the validity of the proposed model is demonstrated via a practical case. Results show that traditional SSI model ignoring the dependence between stress and strength more easily overestimates product reliability than the new dependent SSI model.

Increase in the Detection Sensitivity of a Lateral Flow Assay by Oriented Immobilization of Antibody

Yiseul RYU,Zongwen JIN,Mun Suk KANG,Hak-Sung KIM 한국생물공학회 2012 한국생물공학회 학술대회 Vol.2012 No.4

A method of determining test load for full-scale wind turbine blade fatigue tests

Qiang Ma,Zongwen An,Jianxiong Gao,Hai-Xia Kou,Xue-Zong Bai 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.11

Full-scale fatigue test is an effective method for validating the fatigue performance of wind turbine blade. Its primary problem is how to design the test load. The conventional approach to determine test load requires a complicated and time-consuming process. Thus, a simplified method for directly converting load spectrum of blade into test load is proposed in this paper. Firstly, beam theory is used to obtain the relationship between stress, strain and bending moment of blade cross section. Based on the assumption of local stress concentration and linear relationship between stress and strain, M-N curves (applied moment vs. allowable number of cycles to failure) is defined. Secondly, based on Miner's linear cumulative damage theory and constant life diagram, the equivalent fatigue cumulative damage of load spectrum which is equal to the damage of full-scale fatigue test is obtained. Then, in the case of the selected test load ratio and cycles, the mean and amplitude of test load can be solved. Finally, the validity of the proposed method is verified by an illustrative example. The result indicates that the error of the calculated results between this method and the traditional method is close to 5 %, and it can be used for fatigue test and improve the efficiency of test load design.

A Novel Cross-Layer Dynamic Integrated Priority-Computing Scheme for 3G+ Systems

Wang, Weidong,Wang, Zongwen,Zhao, Xinlei,Zhang, Yinghai,Zhou, Yao The Korea Institute of Information and Commucation 2012 Journal of communications and networks Vol.14 No.1

As Internet protocol and wireless communications have developed, the number of different types of mobile services has increased gradually. Existing priority-computing schemes cannot satisfy the dynamic requirements of supporting multiple services in future wireless communication systems, because the currently used factors, mainly user priority, are relatively simple and lack relevancy. To solve this problem and provide the desired complexity, dynamic behavior, and fairness features of 3G and beyond 3G mobile communication systems, this paper proposes a novel cross-layer dynamic integrated priority-computing scheme that computes the priority based on a variety of factors, including quality of service requirements, subscriber call types, waiting time, movement mode, and traffic load from the corresponding layers. It is observed from simulation results that the proposed dynamic integrated priority scheme provides enhanced performance.