A New Method to Measure the Conversion of Radiation Polymerization of Electrolyte Monomer Diallyldimethylammonium Chloride in Dilute Aqueous Solution

Zhang, Yalong,Yi, Min,Ren, Jing,Zhai, Maolin,Ha, Hongfei The Polymer Society of Korea 2003 Macromolecular Research Vol.11 No.3

The dependence of electrical conductivity on concentrations of diallyldimethylammonium chloride (DADMAC) monomer, linear poly(DADMAC) and their mixture monomer/poly(DADMAC) in dilute aqueous solution exhibits a linear relationship. It was possible to calculate conversion of DADMAC polymerization by measuring its electric conductivity. Although the electrical conductivity of the poly(DADMAC) solution decreased with increasing its molecular weight, in the process of UV or ionizing radiation polymerization the molecular weight of the polymers could be kept constant in the case of fixed temperature, UV-luminous intensity or dose rate. Based on the method mentioned above, the kinetics of UV induced polymerization of DADMAC in aqueous solution was studied; the overall activation energy of polymerization of DADMAC in the water phase was calculated to be 18.8 kJ mol$^{-1}$ . ${\gamma}$-Radiation-induced polymerization of DADMAC in aqueous solution as a function of absorbed dose was studied as well. The conversion of DADMAC increased quickly with dose before 30 kGy and then increased slowly. The experimental data of both UV- and ${\gamma}$-induced polymerization were verified to be reliable by inverted ultracentrifugation method.

A New Method to Measure the Conversion of Radiation Polymerization of Electrolyte Monomer Diallyldimethylammonium Chloride in Dilute Aqueous Solution

Yalong Zhang,Min Yi,Jing Ren,Maolin Zhai,Hongfei Ha 한국고분자학회 2003 Macromolecular Research Vol.11 No.3

Effect of carbon nanotube addition on friction coefficient of nanotubes/hydroxyapatite composites

Qian Zhao,Yalong Shen,Meiru Ji,Lei Zhang,Tingshun Jiang,Cangsheng Li 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.2

Carbon nanotubes/hydroxyapatite (CNTs/HA) composites with different CNTs contents were synthe-sized by in situ method and were characterized by XRD, TEM and Raman spectroscopy. Frictioncoefficients of the composites were tested using UMT-2 friction tester. Effect of various factors includingCNTs content, testing time and applied load on friction coefficient was carried out. Results show that theCNTs/HA composites exhibited lower friction coefficient than pure HA and their friction coefficientsdecreased with increase of CNTs content from 0 to 20 wt.%. Addition of CNTs in composite is beneficial toincrease wear resistance of the CNTs/HA composite and to decrease its friction coefficient.

First-principles study of Ti doping in FeF3$0.33H2O

Zhenhua Yang,Zhijuan Zhang,Yalong Yuan,Yunqing Huang,Xianyou Wang,Xiaoying Chen,Shuangying Wei 한국물리학회 2016 Current Applied Physics Vol.16 No.8

The effect of Ti doping on the geometrical and electronic structures of FeF3$0.33H2O are systematically investigated by using the first principles calculations. We focused on TixFe1-xF3$0.33H2O systems, in which x is equal to 0, 0.08, 0.17 and 0.25, respectively. Different kinds of Ti dopant sites are checked and the most stable structure can be obtained by comparison of total energy. The crystal volume of TixFe1- xF3$0.33H2O expands gradually with increasing Ti doping concentration. Calculated formation energies indicate TixFe1-xF3 is easiest to fabricate and the difficulty of Ti doping FeF3 with hexagonal-tungstenbronze( HTB) structure decreases with the increase of Ti doping concentration under the Fe-rich and Ti-rich growth conditions. Moreover, TixFe1-xF3$0.33H2O is thermodynamically stable, indicating that water molecule can preferentially occupy one-dimensional cavity in the TixFe1-xF3. The band gap of TixFe1-xF3$0.33H2O decreases with increasing Ti doping concentration and Ti0.25Fe0.75F3$0.33H2O exhibits character of half metal, indicating that the conductivity of FeF3$0.33H2O can be improved by Ti-doping. Besides, it can be confirmed that Ti-doping also can broaden the hexagonal cavity in the FeF3$0.33H2O by analyzing the crystal structure of FeF3$0.33H2O and TixFe1-xF3$0.33H2O. With excellent conductivity and larger hexagonal cavity, TixFe1-xF3$0.33H2O can afford open diffusion channels. Therefore, Li ions can remain unblocked, which is beneficial to fast charge and discharge.

Is the mobile touch device a good tool to learn Chinese?

Zhe Chen,Yatzu Tsao,Bumsuk Kim,Philipp Osterwald,Da Sun,Xuhui Liu,Yalong Chen,Constantin Siemons,Jean Elie Guillaume,Shuiping Chen,Liangliang Zhang,Karl Jesper Ornerud 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

Learning Chinese language becomes increasingly important and popular worldwide. It is a challenge for native alphabetic language speaker to learn Chinese as Chinese is a symbolic language. Various learning methods are used to help foreign students to improve their learning performance. Interactive applications in the mobile touch devices make it possible to learn Chinese anytime anywhere. It is interesting to discover the role of mobile touch devices in Chinese learning. Thus, this study investigated the usability of mobile touch devices, including mobile phones and tablet personal computer, in Chinese learning for foreign students. This study included two phases. In the first phase, an online survey and an after-interview were used to investigate the users’ attitude to using mobile touch devices in Chinese learning. Thirty international students were invited to the survey (19 males and 11 females) with 10 Germany, 4 French, 3 Italians, 2 Iranian, 2 Russians, 2 English, 2 American, 1 Indonesian, 1 Pakistani, 1 Thai, 1 Swedish and 1 Kazakhstan. In the second phase, an experiment was conducted to evaluate the effect of mobile touch devices in Chinese learning. Fourteen participants were invited to experiment with 8 international students and 6 Chinese students. International students were considered as beginner learner students compared to Chinese students who were considered as advanced learner. Both Android and iOS developing systems for smart devices are considered in the experiment. The results of the survey showed users have a positive attitude towards using mobile touch devices in Chinese learning. The interview results indicated that most participants were willing to pay for it if the usability of learning tool in mobile devices improves. The experiment results indicated the advantage and disadvantage of using mobile phones and tablets in Chinese learning. It was suggested that beginning leaner regarded motivation and organization of Chinese learning tool in the mobile devices. Advanced learner focused on visual design, touch performance, cognitive process. As an exploration of usability of mobile touch device in Chinese learning, this study found that user held a positive attitude to learning Chinese in mobile touch devices. Mobile touch device is a good tool to learn Chinese as it provides interactive learning tools. However, it needs much effort for the mobile application designer to improve the usability. This study had suggestions on how to develop a user-friendly Chinese learning tool in touch mobile devices.

Is the Mobile Touch Device a Good Tool to Learn Chinese?

( Zhe Chen ),( Bumsuk Kim ),( Philipp Osterwald ),( Da Sun ),( Xuhui Liu ),( Yalong Chen ),( Constantin Siemons ),( Jean Elie Guillaume ),( Shuiping Chen ),( Liangliang Zhang ),( Karl Jesper Ornerud ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

Learning Chinese language becomes increasingly important and popular worldwide. It is a challenge for native alphabetic language speaker to learn Chinese as Chinese is a symbolic language. Various learning methods are used to help foreign students to improve their learning performance. Interactive applications in the mobile touch devices make it possible to learn Chinese anytime anywhere. It is interesting to discover the role of mobile touch devices in Chinese learning. Thus, this study investigated the usability of mobile touch devices, including mobile phones and tablet personal computer, in Chinese learning for foreign students. This study included two phases. In the first phase, an online survey and an after-interview were used to investigate the users`attitude to using mobile touch devices in Chinese learning. Thirty international students were invited to the survey (19 males and 11 females) with 10Germany, 4 French, 3 Italians, 2 Iranian, 2 Russians, 2 English, 2 American, 1 Indonesian, 1 Pakistani, 1 Thai, 1 Swedish and 1 Kazakhstan. In the second phase, an experiment was conducted to evaluate the effect of mobile touch devices in Chinese learning.