http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nguyen, Van-Toan,Tran, Quoc Chinh,Quang, Nguyen Duc,Nguyen, Ngoc-Anh,Bui, Van-Tien,Dao, Van-Duong,Choi, Ho-Suk Elsevier 2018 Journal of alloys and compounds Vol.766 No.-
<P><B>Abstract</B></P> <P>The improvement of the catalytic performance for methanol and formic acid oxidation reactions remains a key issue for the development of a new generation of direct methanol and formic acid fuel cells. This study reports a simple approach, using selective chemical etching for the synthesis of unique nitrogen-doped carbon dot/Pt<SUB>84</SUB>Pd<SUB>16</SUB> (N-Cdot/Pt<SUB>84</SUB>Pd<SUB>16</SUB>) nano-network structure at room temperature with excellent electrocatalytic properties. The obtained nano-network hybrid material exhibits significant enhancement of the electrocatalytic activity for the electro-oxidation reaction of both methanol and formic acid with current densities of 999.0 and 1919.5 mA/mg<SUB>metal</SUB>, respectively, compared with the commercial ones of 751.32 and 806.02 mA/mg<SUB>metal</SUB>, respectively. Furthermore, the N-Cdot/Pt<SUB>84</SUB>Pd<SUB>16</SUB> nano-network hybrid materials exhibit excellent stability and hydrophilic dispersibility at room temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N-Cdot/PtPd nanonetwork hybrid material is synthesized at room temperature. </LI> <LI> A simple coreduction and a selective chemical etching are applied to the synthesis. </LI> <LI> It generates a nano-network structure with excellent electrocatalytic properties. </LI> <LI> N-Cdot functions as a uniform interconnection between the nanohybrid materials. </LI> <LI> The hybrid exhibits significant enhancement of the activity for both MOR and FAOR. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Minh Luon,Nguyen Ngoc Bich,Le Van Thanh Son,Nguyen Trung Kien,Dao Ngoc Nhiem,Nguyen Thanh Tuoi,Dinh Quang Khieu 대한환경공학회 2024 Environmental Engineering Research Vol.29 No.4
In the present work, ZnO/g-C₃N₄/biochar was prepared, and it was used for visible-light driven photocatalytic degradation of some colorants (methylene blue, rhodamine B, methyl orange) and some antibiotics (doxycycline, ciprofloxacin, amoxicilline). Biochar was prepared by pyrolysing Phragmites australis biomass. The ZnO/g-C₃N₄/biochar composite was synthesized with the alkaline hydrolysis method. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transition electron microscopy, energy dispersive X-ray/elemental mapping, ultraviolet-visible-diffuse reflectance spectroscopy, photoluminescence spectroscopy, nitrogen adsorption/desorption isotherms and X-ray photoelectron spectroscopy. The results show that ZnO nanoparticles with a large surface area are highly dispersed on the g-C₃N₄ particle surface and biochar. The composite exhibits superior photocatalytic degradation ability toward doxycycline, a broad-spectrum antibiotic of the tetracycline compared with individual components (ZnO or g-C₃N₄) and satisfies stability after six treatment cycles. The kinetics and degradation mechanisms of doxycyline were also addressed. In addition, the present catalyst also exhibits the photocatalytic degradation of methylene blue, rhodamine B, methyl orange, ciprofloxacin and amoxicillin in visible-light regions.
Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Mau Thanh,Nguyen Duc Vu Quyen,Vo Thang Nguyen,Dao Ngoc Nhiem,Dinh Quang Khieu 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.3
In this study, longan seeds - an agricultural by-product was used to fabricate activated carbon (LSAC) through two-step pyrolysis with pre-carbonization at low temperature in the first step and then activation by H3PO4. LSAC with large surface area and porous structure exhibits an excellent capacity of absorption towards both cationic dyes (methylene blue (MB), rhodamine-B (RhB)) and anionic dyes (methyl orange (MO), congo red (CR)). Experimental data can be described well by the pseudo-second kinetic model. The maximum adsorption capacity based on Langmuir isotherm model was found as 502.84; 397.77; 464.66 and 350.64 mg.g−1 for MB, RhB, MO and CR, respectively. The adsorption of MB, RhB and CR on LSAC is spontaneous and endothermic, while that for MO is spontaneous but exothermic. Furthermore, the adsorption mechanism of dyes on LSAC was also studied showing that it can occur by electrostatic interaction, hydrogen bonding, the filling of pores involving the interaction between dye ions with specific functional groups such as –OH, –COOH, –NH2 and –PO43− on the LSAC surface. These results suggest that LSAC material may be envisaged as a promising adsorbent for treatment of wastewater in textile industries.
Highly efficient adsorption of arsenite from aqueous by zirconia modified activated carbon
Pham Ngoc Chuc,Nguyen Quang Bac,Dao Thi Phuong Thao,Nguyen Trung Kien,Nguyen Thi Ha Chi,Nguyen Van Noi,Vo Thang Nguyen,Nguyen Thi Hong Bich,Dao Ngoc Nhiem,Dinh Quang Khieu 대한환경공학회 2024 Environmental Engineering Research Vol.29 No.2
Dao Hang Thi,Beattie George Andrew Charles,Watson Gillian W.,Mottern Jason,Evans Greg,Van Nguyen Liem,Nguyen Hoa Thi,Nguyen Viet Duc,Holford Paul 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.2
The false coconut scale, Aspidiotus rigidus Reyne (Hemiptera: Diaspididae), is a serious pest of coconut in the Indonesian and Philippine archipelagos. Field surveys in Viêt Nam in 2015–2018 discovered A. rigidus (a new country record). Also found were three of its primary hymenopteran parasitoids: an unidentified ectoparasitic Aphytis species (Aphelinidae) and two endoparasitoids, Comperiella calauanica (Encyrtidae) and Pteroptrix parvipennis (Aphelinidae). Aphytis sp. was the commonest parasitoid; the average level of parasitism of A. rigidus found in six surveys was 46%, in immatures of both sexes and adult females. Comperiella calauanica was recorded in three surveys, with an average parasitism level of 54% in adult female A. rigidus. It was also found attacking Aspidiotus destructor Signoret. Pteroptrix parvipennis was recorded in 47% of second instar A. rigidus in one survey. In molecular phylogenies based on 28S and COI genes, Pteroptrix parvipennis grouped with species of Encarsia. Although A. rigidus occurs in the largest coconut-growing areas in Việt Nam, incidence of the scale is low, and no outbreaks have been recorded. Its parasitoids therefore have potential for use as biological control agents in areas where the scale is problematic. The low incidence of A. rigidus in Việt Nam and the presence of the three parasitoid species there suggests that the scale and these parasitoids originated in Indochina.
Dao, Van-Duong,Larina, Liudmila L.,Tran, Quoc Chinh,Bui, Van-Tien,Nguyen, Van-Toan,Pham, Thanh-Dong,Mohamed, Ibrahim M.A.,Barakat, Nasser A.M.,Huy, Bui The,Choi, Ho-Suk Elsevier 2017 Carbon Vol.116 No.-
<P>This work focuses on systematic studies of dissolution engineering for Pt0.9M0.1/graphene(M = Au, Co, Cu, Fe, Mo, Ni, Pd, Ru, and Sn) counter electrodes (CEs). The developed nanohybrid materials exhibit higher catalytic activity and electrical conductivity compared with those of Pt/graphene CEs. The results also indicate the improved stability of the developed CEs in iodide electrolyte. Furthermore, the trend in the variation of the reactivity of the PtM alloys agrees well with the concept of density functional theory (one-electron description). An enhancement in the catalytic activity of the developed nanohybrids results from the electronic effect that originates from an upward shift of the platinum d-band to the Fermi energy level upon alloying. Thus, the Pt(0.9)M(0.1)graphene nanohybrids are cost-effective alternative CE materials to the expensive Pt. The obtained results provide a foundation for enhancing the catalytic activities of CEs for dye-sensitized solar cells (DSCs). The implementation of the Pt0.9M0.1/graphene nanohybrids offers significant potential for increasing the efficiency of DSCs. (C) 2017 Elsevier Ltd. All rights reserved.</P>
Nguyen, Van Dao,Min, Byoung-Cheol,Kyung, Myung-Ok,Park, Jong-Tae,Lee, Byong Hoon,Choi, Chung-Hyo,Seo, Nam-Seok,Kim, Yong-Ro,Ahn, Dong Uk,Lee, Sung-Joon,Park, Cheon-Seok,Kim, Jung-Wan,Park, Kwan-Hwa John Wiley Sons, Ltd. 2009 Phytochemical analysis Vol.20 No.6
<P>Introduction – Kudzu root (Radix puerariae) is a rich source of isoflavones that are effective in preventing osteoporosis, heart disease and symptoms associated with menopause. The major isoflavonoids in kudzu root extracts were reported as puerarin, daidzin and daidzein. Recently, an unknown isoflavonoid (compound 1) was detected from one-year-old kudzu root cultivated in Vietnam.</P><P>Objective – To identify a novel compound 1 in kudzu root extract and determine the structure of the compound by ESI<SUP>+</SUP> TOF MS-MS, <SUP>1</SUP>H-, <SUP>13</SUP>C-NMR and enzymatic hydrolysis.</P><P>Methodology – Samples were prepared by extraction of one-year-old kudzu root with 50% ethanol and the isoflavonoids were purified using recycling preparative HPLC. Unknown compound 1 was detected using UV-light at 254 nm in TLC and HPLC analyses. The molecular weight of 1 was determined using a TOF mass spectrometer equipped with an electrospray ion source. The structure of 1 was determined from the <SUP>13</SUP>C and <SUP>1</SUP>H NMR spectra recorded at 100.40 and 400.0 MHz, respectively.</P><P>Results – ESI<SUP>+</SUP> TOF MS-MS analysis shows that 1 is a puerarin diglycoside. The interglycosidic linkage of diglycoside determined by <SUP>1</SUP>H-, <SUP>13</SUP>C-NMR, and enzymatic hydrolysis suggests that 1 has a glucosyl residue linked to puerarin by an α-1,6-glycosidic bond. This compound is the first naturally-occurring 8-[α-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl]daidzein in kudzu root. The concentration of glucosyl-α-1,6-puerarin in kudzu root was 2.3 mg/g as determined by HPLC.</P><P>Conclusion – The results indicate that puerarin diglycoside is one of the major isoflavonoids in kudzu root and has a significant impact on the preparation of highly water-soluble glycosylated puerarin. Copyright © 2009 John Wiley & Sons, Ltd.</P>
NGUYEN, Phu Ha,NGUYEN, Phi-Hung,TSAI, Jung-Fa,NGUYEN, Thanh Tam,HO, Van Nguyen,DAO, Trong-Khoi Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12
In accordance with huge demand for capital to meet the expansion of steel production, there are more and more steel companies who have officially listed their stocks in HOSE and HNX. One of the key issues in successful initial public offerings and seasonal offerings for these companies is how to make stocks of steel companies become more attractive in the eyes of investors. The purpose of this research is to analyze the determinants of share prices of listed steel companies in Vietnam. This study utilized macro-economic variables, ratios and indicators representing characteristics of steel industry collected from Quarter 1/2006 to Quarter 4/2019 in association with the panel data and the feasible generalized least square (FGLS) model to evaluate the degree of these factors on the share prices. The results of the research show that ROE, Cons_rate, and CO2_rate are three main factors affecting the share prices of listed steel companies. Among which, ROE and Cons_rate have a positive effect, while CO2_rate has a negative effect on the share prices of listed steel companies. It also confirms the relationship between the environmental factor, construction industry factor and the stock prices. This lays foundations for recommendations for the future policies towards environmental protection and sustainable development.