A Criterion Describing the Dynamic Yield Behavior of PMMA

Ji Qiu,Tao Jin,Buyun Su,Qian Duan,Xuefeng Shu,Erqiang Liu,Xin Li 한국고분자학회 2019 Macromolecular Research Vol.27 No.8

Dynamic uniaxial and multiaxial tests were conducted to characterize the mechanical behavior of poly(methyl methacrylate) (PMMA). In this case, the multiaxial yield behavior of materials can be captured by the shear-compression samples (SCS). The experimental results were compared with different yield criteria, and which does not have a good agreement between theoretical prediction and experimental yield loci of PMMA undergoing combined shear-compression. Therefore, a phenomenological yield criterion is developed, and it notably involves hydrostatic stress sensitivity, lode angle, and one parameter. The parameter can be expressed by the asymmetry of yield strength between the tension and compression. The proposed criterion was verified by the utilization of differently combined shear-compression tests. The investigative results reveal that the proposed criterion can be successfully applied to describe the complex yield behavior of PMMA under dynamic loading conditions. The present study shows an efficient method to develop yield criterion of the reviewed materials.

Spirit, Culture And The Services

Luo Jiqiu 한국유통과학회 2013 한국유통과학회 학술대회 논문집 Vol.2013 No.-

Adam Smith had studied impersonal and personal exchange. GATS faces the dilemma of trade in services and culture diversity. Culture is distinctive in spirit and morality. As a result, services are simultaneously ongoing of economic behavior and spirit living among peoples.

In Situ Growth of FeCo-selenide on Ni Foam as High-Performance Electrode for Electrochemical Energy Storage Devices

An Ye,Jiqiu Qi,Yanwei Sui,Fei Yang,Fuxiang Wei,Yezeng He,Qingkun Meng,Zhi Sun 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.7

A solid-state energy storage device has been fabricated using FeCo-selenide nanosheet arrays as positive electrode and Fe2O3 nanorod as negative electrode. As an electrode material, the ternary FeCo-selenide nanosheet arrays supported by Ni foam show a highest specific capacitance of 978 F/g (specific capacity of 163 mAh/g) at 1 A/g and a superior cycle behavior of 81.2% are obtained after 5000 cycles at current density of 4 A/g. The asymmetric supercapacitor achieves the maximum energy density of 34.6Wh/kg at the power density of 759.6 W/kg. Furthermore, the superior cycling stability with 83% retention of initial capacitance after 5000 cycles further verify the practical applications of FeCo-selenide//Fe2O3 asymmetric supercapacitor. Meanwhile, the LED bulb and the light board of "CUMT" are lighted by connecting several capacitors to form a series circuit.

Functional Evaluation of Transplanted Kidneys with Reduced Field-of-View Diffusion-Weighted Imaging at 3T

Yuan Xie,Yanjun Li,Jiqiu Wen,Xue Li,Zhe Zhang,Jianrui Li,Yan’e Zhao,Peng Wang,Jun Zhang,Ying Tian,Long Jiang Zhang,Guang Ming Lu 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.2

Objective: To determine the feasibility of reduced field-of-view diffusion-weighted imaging (rFOV DWI) with multi-b values to detect functional variability in transplanted kidneys. Materials and Methods: Using a 3T MRI scanner, multi-b rFOV DWI of transplanted kidney or native kidney was performed in 40 renal transplantation recipients and 18 healthy volunteers. The patients were stratified, according to an estimated glomerular filtration rate (eGFR): Group 1, eGFR ≥ 60 mL/min/1.73 m2; Group 2, eGFR ≥ 30 mL/min/1.73 m2 and < 60 mL/min/1.73 m2; Group 3, eGFR < 30 mL/min/1.73 m2. Total apparent diffusion coefficient (ADCT), perfusion-free ADC (ADCD) and perfusion fraction (FP) of kidneys were calculated and compared among the four groups. Correlations between the imaging results and eGFR were assessed. Results: All volunteers had eGFR ≥ 60 mL/min/1.73 m2, while 16, 16, and 8 patients were included in Groups 1, 2, and 3, respectively. In the renal cortex, ADCT was higher in Group 1 ([1.65 ± 0.13] x 10-3 mm2/s) than Group 3 ([1.44 ± 0.11] x 10-3 mm2/s) (p < 0.05), and the inter-group differences of FP values were significant (all p < 0.05) (0.330 ± 0.024, 0.309 ± 0.019, 0.278 ± 0.033, and 0.250 ± 0.028 for control group, Groups 1, 2, and 3, respectively). Renal cortical ADCT, ADCD, FP, and renal medullary ADCT and FP correlated positively with eGFR (r = 0.596, 0.403, 0.711, 0.341, and 0.323, respectively; all p < 0.05). When using 0.278 as the cutoff value, renal cortical FP had a sensitivity of 97.1% and a specificity of 66.7% for predicting decreased renal function. Conclusion: Multi-b rFOV DWI presents transplanted kidneys with high resolution, which is a promising functional tool for non-invasively monitoring function of transplanted kidneys.

Controllable Zn0.76Co0.24S Nanoflower Arrays Grown on Carbon Fiber Papers for High-Performance Supercapacitors

Man Zhang,Yanwei Sui,Xiaofang Yuan,Jiqiu Qi,Fuxiang Wei,Qingkun Meng,Yezeng He,Yaojian Ren,Zhi Sun,Jinlong Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

A nanoflower structure of Zn0.76Co0.24S directly grown on carbon fiber papers (CFP) was successfully designed by a mild two-step hydrothermal method. Benefiting from their fascinating structural features, Zn0.76Co0.24S/CFP electrode exhibits a maximum specific capacitance of 300 F g -1 at current density of 1 A g -1 and 84% capacitance retention after 5,000 cycles at current density of 5 Ag -1. Subsequently, Zn0.76Co0.24S/CFP//AC all-solid-state asymmetric supercapacitor (ASC) device is assembled and able to illuminate the red LEDs. ASC devices deliver a maximum energy density of 9.59 Wh kg -1 at a power density of 750 W kg -1. Therefore, this impressive result demonstrates that the nanoflower Zn0.76Co0.24S have promising applications in the development of high-performance supercapacitors.

Hydrothermal Synthesis of Ni-MOF Vulcanized Derivatives for High-Performance Supercapacitors

Shuwen Gao,Yanwei Sui,Fuxiang Wei,Jiqiu Qi,Qingkun Meng,Yaojian Ren,Yezeng He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

A series of nickel sulfides derived from the hexagonal Ni-MOF are vulcanized through adjusting the hydrothermal time and the thiourea concentration. Among all the obtained nickel sulfides, one sample Ni-S2-3, which inherits the Ni-MOF's morphology, shows the best electrochemical performance with a remarkable specific capacitance of 1128 Fg -1 at 1 Ag -1, a rate capacitance of 50% and a long cycle life of 74% retention after 5000 cycles. Furthermore, the asymmetrical supercapacitors (SCs) based on Ni-S2-3//AC exhibit a good supercapacitive performance with a maximum power density of 16.3 Wh kg -1 at a power density of 800 Wkg -1. All these results indicate that vulcanizing Ni-MOF is an effective way to fabricate a superior electrode material with excellent electrochemical performance for SCs.

One-Step Hydrothermal Synthesis of CoNi2S4 for Hybrid Supercapacitor Electrodes

Peng Liu,Yanwei Sui,Fuxiang Wei,Jiqiu Qi,Qingkun Meng,Yaojian Ren,Yezeng He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

In this study, a simple one-step hydrothermal method was developed to prepare a novel hierarchical CoNi2S4 nanostructure similar to rambutan fruit. The surface microstructural study clearly visualized that the rambutan-like CoNi2S4 consists of nanorods grown directly on the surface of spherical core structures. The close attachment of the nanorods to the spheres increased the active areas of the electrode, which facilitates efficient charge transport from the nanorods to the spherical core structure. CoNi2S4 with a rambutan-like hierarchical structure showed an excellent specific capacitance of 944 F g -1 at 1 A g -1, considerable rate capacitance (75.6% retention at 10 Ag -1) and excellent cycling life (91.1% retention after 5000 circulations) in the three-electrode system. Besides, the assembled hybrid supercapacitor based on CoNi2S4 and reduced graphene oxide exhibited a high specific energy density of 23.58 Wh kg -1 at the power density of 800 W kg -1.

Effects of Carbonization Temperature on Nature of Nanostructured Electrode Materials Derived from Fe-MOF for Supercapacitors

Yanwei Sui,Dongling Zhang,Yongpeng Han,Zhi Sun,Jiqiu Qi,Fuxiang Wei,Yezeng He,Qingkun Meng 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.5

This work successfully demonstrates various temperature carbonization of iron based metal organic framework to deriveelectrode materials for supercapacitors. Furthermore, impacts of calcined temperatures on the nature of as-prepared productsare reported, and samples obtained at 300, 400, 500, 600 and 700 °C were investigated respectively. The products revealsexcellent electrochemical performance. Carbonized at 600 °C, the composite materials display the highest specific capacitanceof 972 F/g at a current density of 1 A/g. Carbonized at 500 °C, the capacitance retention of materials reach up to 93%. The high specific capacitance and excellent cyclic stability of the developed materials would exhibit nice prospect for thepractical utilization of electrode materials.

ZnO@Ni–Co–S Core–Shell Nanorods-Decorated Carbon Fibers as Advanced Electrodes for High-Performance Supercapacitors

Yanwei Sui,Man Zhang,Haihua Hu,Yuanming Zhang,Jiqiu Qi,Fuxiang Wei,Qingkun Meng,Yezeng He,Yaojian Ren,Zhi Sun 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

The interconnected three-dimensional Ni–Co–S nanosheets were successfully deposited on ZnO nanorods by a one-step potentiostatic electrodeposition. The Ni–Co–S nanosheets provide a large electrode/electrolyte interfacial area which has adequate electroactive sites for redox reactions. Electrochemical characterization of the ZnO@Ni–Co–S core–shell nanorods presents high specifc capacitance (1302.5 F/g and 1085 F/g at a current density of 1 A/g and 20 A/g), excellent rate capabilities (83.3% retention at 20 A/g) and great cycling stability (65% retention after 5000 cycles at a current density of 30 A/g). The outstanding electrochemical performance of the as-prepared electrode material also can be ascribed to these reasons that the special structure improved electrical conductivity and allowed the fast diffusion of electrolyte ions.

PRESERVATION OF MECHANICAL AND ENERGETIC FUNCTION AFTER ADENOVIRAL GENE TRANSFER IN NORMAL RAT HEARTS

Sakata, Susumu,Liang, Lifan,Sakata, Naoya,Sakata, Yuri,Chemaly, Elie R,Lebeche, Djamel,Takewa, Yoshiaki,Chen, Jiqiu,Park, Woo Jin,Kawase, Yoshiaki,Hajjar, Roger J Blackwell Publishing Asia 2007 Clinical and experimental pharmacology & physiolog Vol.34 No.12

<P>SUMMARY</P><OL TYPE='1'><li level='1'>The aim of the present study was to examine the acute and chronic effects of adenoviral gene transfer on cardiac function in terms of left ventricular (LV) mechanoenergetic function. Recombinant adenoviral vector carrying &bgr;-galactosidase and green fluorescent protein genes (Ad.&bgr;gal-GFP) was used. Cardiac function was examined in cross-circulated rat heart preparations, where end-systolic/diastolic pressure–volume relationships (ESPVR/EDPVR), systolic pressure–volume area (PVA), LV relaxation rate, equivalent maximal elastance at mid-range LV volume (eE<SUB>max</SUB> at mLVV), coronary blood flow, coronary vascular resistance and myocardial oxygen consumption (VO<SUB>2</SUB>) were also measured.</LI><li level='1'>To examine the <I>ex vivo</I> acute effects of the adenoviral vector, data were obtained before and 30–90 min after intracoronary infusion of Ad.&bgr;gal-GFP in the excised, cross-circulated hearts that underwent serotonin pretreatment. To examine the <I>in vivo </I>chronic effects of adenoviral gene transfer, normal rat hearts received Ad.&bgr;gal-GFP or saline by a catheter-based technique and data were obtained 3 days after the injection of Ad.&bgr;gal-GFP or saline.</LI><li level='1'>The ESPVR, EDPVR, LV relaxation rate, eE<SUB>max</SUB> at mLVV, coronary blood flow and coronary vascular resistance remained unchanged in Ad.&bgr;gal-GFP-transfected hearts in both <I>ex vivo</I> acute and <I>in vivo </I>chronic experiments. Moreover, the <I>ex vivo</I> and <I>in vivo </I>transfection caused no change in the slope and VO<SUB>2</SUB> intercept of the VO<SUB>2</SUB>–PVA relationship, VO<SUB>2</SUB> for basal metabolism and for Ca<SUP>2+</SUP> handling in excitation–contraction coupling and O<SUB>2</SUB> costs of LV contractility.</LI><li level='1'>These results indicate that adenoviral gene transfer has neither acute nor chronic toxic effects on LV mechanical and energetic function. A special combination of <I>in vivo </I>adenoviral gene transfer and a cross-circulation experimental system may provide a useful novel strategy to explore the functional and mechanoenergetic role of specifically targeted genes in the diseased heart.</LI></OL>