http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
ZIF-67 modified MXene/sepiolite composite membrane for oil–water separation and heavy metal removal
Qiuxiang Wang,Zongxue Yu,Ximei Zhu,Qingcan Xiang,Haidong Chen,Yao Pang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-
In this study, polyvinylpyrrolidone (PVP) was used as a cross-linking agent leading to ZIF-67 in-situ growon the surface of sepiolite (Sep) to increase the specific surface area and space volume of Sep. Subsequently, a hydrothermal synthesis method was used to form a stable super-hydrophilic compositemembrane from the composite MXene by polydopamine. Compared to the MXene/PDA/Sep (MPS) compositemembrane, the composite membrane with ZIF-67 exhibited improved hydrophilicity and heavymetal separation. In addition, the introduction of negatively charged Sep@ZIF-67–24 (SZ-24) increasedthe number of adsorption active sites and negative potential for the surface of the membrane, and thiswas conducive to the demulsification and adsorption of oil–water emulsions. The MXene/PDA/Sep@ZIF-67–1 (MSZ-1) composite membrane had excellent separation effects on surfactant-stabilizedemulsions (SSEs) and surfactant-free emulsions (SFEs) oil–water emulsions which were above 99.4 %. Furthermore, the separation effect on oil–water, under extreme water conditions, was greater than99 %. The MSZ-1 composite membrane can achieve excellent separation of heavy metal ions, especiallyCu2+ that the rejection was 79.9 %, under high flux and extreme conditions. Therefore, the MSZ-1 compositemembrane has broad application prospects in oil–water treatment and heavy metal separation.
Yuanyuan Zhang,Qiuxiang Zhao,Hui Tang,Huiling Li,Depeng Li,Zhiyong Wang,Xin Gao,Fanye Wang 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.5
Enantiopure esomeprazole is an important drug in the treatment of gastric ulcer. The asymmetric sulfoxidation of omeprazole thioether was catalyzed by immobilized cells of a mutant of Rhodococcus rhodocrous ATCC 4276 to synthesize esomeprazole. The bioreaction was carried out in a biphasic system (chloroform-water), at a high substrate concentration (200mM), and optimized using response surface methodology (RSM). The optimal yield of esomeprazole obtained was 94.8% with e.e. (>99%) without the formation of the sulfone form as a byproduct, under the optimal conditions: the concentration of immobilized cells, 283.5 g/L, the incubation temperature, 37.05 oC, and pH of phosphate buffer, 7.35, respectively. A quadratic polynomial model was developed with R2 of 0.9998, which indicates that the model predicts the observed data with very high accuracy. The mutant exhibited a high enantioselective activity and substrate and product tolerance. The small size of immobilized cell beads (0.5-1 mm) creates a large reaction interface. The aerated flask provides enough oxygen for a high concentration of cells. The significant improvement of substrate tolerance may mainly be attributed to employing the chloroform-water biphasic system because organic substrates may be partitioned in the organic phase, eliminating potential damage and inhibition to cells. Based on the above, the asymmetric sulfoxidation catalyzed by immobilized bacterial cells is therefore more promising for efficient synthesis of chiral sulfoxides.
Weijun Fang,Qiuxiang Zheng,Ying Fang,Hua-Bin Huang 한국물리학회 2019 Current Applied Physics Vol.19 No.2
The development of a highly effective and recyclable antibacterial agent is of great interest. In this work, magnetic Fe3O4/Ag antibacterial nanoagent was successfully fabricated through a facile surface functionalization approach. Utilizing the strong interaction between silver and the amino groups on the surface of Fe3O4 nanospheres, the nanosized silver particles were tightly bonded on the Fe3O4 nanospheres' surface, improving silver nanoparticalsʼ antibacterial activity by preventing agglomeration of silver nanoparticles. Our antibacterial tests showed that the as-synthesized Fe3O4/Ag nanospheres presented high antibacterial performance against Gram-negative and Gram-positive bacteria. Moreover, these antibacterial nanohybrids can be easily recycled from water solution by applying an external magnetic field. Overall, taking into consideration the facile preparation method, excellent antibacterial activity and high magnetic recycling property, the as-synthesized Fe3O4/Ag nanospheres have great potential applications in medicine and water disinfection.
Burcu Erdemir,Wu Qiuxiang 서울대학교 교육연구소 2023 Asia Pacific Education Review Vol.24 No.1
Despite the potential of tertiary education to generate higher incomes and close the poverty gap within and between countries, it is still a challenge for many countries to ensure equity and quality in their higher education admissions. Compared to the more privileged, students from marginalized backgrounds face inequitable inputs that restrict their academic and personal growth. This comparative analysis used a capabilities approach-based model to examine the personal, discriminatory, institutional, and geographical barriers many students face in the higher education admission processes in Turkey and China. As long as student stratification persists, equity in education cannot be attained; therefore, several gender equality, equity, diversity, and quality-based policy alternatives are presented that focused on grading systems, curriculum and instruction, and quota system changes. Further recommendations are also given for the development of courses and regional development programmes that can assist disadvantaged students convert functionings into capabilities from an early age.
Quangui He,Jia Zhuang,Qiuxiang Wen,Yang Deng,Jun Yu,Haimin Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6
An anatase TiO2 photoanode with a novel three-dimensional nest-like structure was prepared directly on a transparent conductive glass substrate through hydrothermal cycles by three times. First, an unidirectional banded structure film was prepared by a facile hydrothermal method. And then, with the time of hydrothermal cycle increased, part of nanobelts were ruptured into a lot of small polyhedrons, but they still maintained a trend of the previous connection, and some fine nanobelts were interweaved in small polyhedrons. Finally, we successfully prepared a film with a novel 3D nest-like structure, and it had all the characteristics of the hierarchitectures. It had better photoelectric properties than the film with fewer times of hydrothermal cycle. Its photoelectric conversion efficiency reached 3.81%, which is due to a large dye adsorption amount, rapid electronic transmission, and superior light scattering and more electrons transmission paths.
Luyao Wang,Guolin Liu,Qiuxiang Tao,Ke Wang 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.12
For the linear and nonlinear parameters that can be separated in the spatial Cartesian coordinate transformation model, we use the variable projection algorithm in this paper to represent the linear parameters with nonlinear parameters, which are transformed into least squares problems with only nonlinear parameters. We simplify the matrix of the nonlinear function by the Gram-Schmidt orthogonalization method, and combine the nonlinear least squares iterative method with the Levenberg-Marquardt (LM) algorithm to solve for the coordinate transformation parameters. Experiments are carried out by solving for the coordinate transformation parameters of the independent spatial Cartesian coordinate system and the CGCS2000 coordinate system. We compare the solution results of the four methods (parameter non-separation method, traditional variable projection method, variable projection method based on QR decomposition, and variable projection method based on Gram-Schmidt orthogonal decomposition) with respect to the calculated results, the number of iterations and the computation time. The experimental results show that the proposed method in this paper requires a lower computation time and achieves higher computational efficiency when obtaining the same solution results and with the same number of iterations.
Current status, challenges, and future prospects of plant genome editing in China
Sulaiman Ahmed,Yandi Zhang,Muhammad Abdullah,Qiuxiang Ma,Hongxia Wang,Peng Zhang 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.5
Genome editing (GE) is the most powerful tool for creating genetic variation in plants. This approach is valuable for studying the mechanism of gene function and regulation as well as to improve desirable traits using sequence-specific endonucleases. It is typically performed with diverse molecular scissors that cleave a particular gene at a defined position. The advent of sequence-specific nucleases such as ZFNs (zinc finger nucleases), TALENs (transcription activator-like effector nucleases), and CRISPR (clustered regularly interspaced short palindromic repeats), in particular, have allowed for the precise and efficient introduction of genetic variation into the genome. The newly developed CRISPR-associated protein 9 (Cas9) variants, base-editing systems, novel RNA-directed nucleases, and DNA-free CRISPR/Cas9 delivery methods offer great opportunities for plant genome engineering. China has made tremendous progress in the field of GE for crop improvement to meet the demand of growing population. Herein, we reviewed the recent progress in GE of different crops in China, highlighting advanced GE tools/methods, and also discussed the specific challenges and prospects of plant GE.