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Journal of Magnesium and Alloys 2023年第10期11卷 3642-3656页

作者： Liling Mo Hengbin Liao Xiong Zhou yu-jun zhao jun Du Department of Metallic Materials School of Materials Science and EngineeringSouth China University of Technology381 Wushan RdGuangzhouGuangdong 510640China Department of Physics South China University of Technology381 Wushan RdGuangzhouGuangdong 510640China

The introduction of oxide inclusions during the smelting process has a clear promising heterogeneous nucleation potency on Mg-based alloys, but the mechanism has not been explored clearly yet. In the present work, the grain refinement mechanism of MgO in pure Mg,Mg-3Al and AZ31(Mg-2.9Al-0.9Zn-0.3Mn) alloys is investigated by combing first-principles calculations and experiments. The theoretical results show that solute atoms adsorption will affect the nucleation and the subsequent growth process, which is an important factor affecting the refinement efficiency. A contradiction between the experimental results and the grain growth restriction factor(GRF) theory is observed,that is the refinement ratio of AZ31 is worse than Mg-3Al alloy. This is explained by an adsorption model which reveals that Al promotes the adsorption of Mg on MgO surface so as to stimulate more particles available as nucleating sites. Meanwhile, Fe and Mn also have favorable effects on the adsorption of Mg, Zn may play the opposite role compared to Al. The theoretical analyzes provide a strong support to the experiments that Al benefits the initial nucleation of α-Mg on MgO to promote the grain refining effect of Mg-3Al prior to AZ31 alloy.

关键词： Magnesium alloy First-principles calculation MgO Grain refinement Adsorption

An in situ infrared study of dimethyl carbonate synthesis from carbon dioxide and methanol over well-shaped CeO2

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Chinese Chemical Letters 2017年第1期28卷 65-69页

作者： shu-yang zhao sheng-ping wang yu-jun zhao xin-bin ma key laboratory for green chemical technology school of chemical engineering and technologytianjin universitycollaborative innovation center of chemical science and engineeringTianjin 300072China

The mechanism of dimethyl carbonate（DMC） formation from CO2 and methanol is investigated using three well-shaped CeO2 catalysts, nanorod, nanocube and octahedron, which are packed with different crystal planes. In situ Fourier Transform Infrared Spectroscopy（FTIR） is employed to probe each reaction step in the DMC synthesis. The number of –OH groups and the species of CO2 adsorptions on ceria surface have significant influence on the activity of ceria with different morphologies. Rod-ceria has favorable catalytic activity because of the large amount of –OH groups and the formation of bidentate carbonate species.

关键词： Dimethyl carbonate CeO2 -OH Bidentate carbonate Crystal planes

Enhancements of dimethyl carbonate synthesis from methanol and carbon dioxide:The in situ hydrolysis of 2-cyanopyridine and crystal face effect of ceria

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Chinese Chemical Letters 2015年第9期26卷 1096-1100页

作者： Sheng-Ping Wang Jing-Jie Zhou Shu-Yang zhao yu-jun zhao Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and EngineeringTianjin University

This paper describes the effect of the in situ hydrolysis of 2-cyanopyridine and its derivatives on the synthesis of dimethyl carbonate（DMC） from CO2 and methanol over CeO2.2-Cyanopyridine.with the highest electronic charge number of the carbon in the cyanogroup,is the most effective agent to accelerate the desired reaction by a decrease of water.CeO2（110） planes are active for the hydrolysis of 2-cyanopyridine,further enhancing the DMC formation by in situ removal of water effectively.The DMC yield is improved drastically up to 378.5 mmol g cat^-1 from 12.8 mmol g cat^-1 with the in situ hydrolysis of 2-cyanopyridine over rod-CeO2（1 1 0） catalyst.

关键词： Dimethyl carbonate CeO2 Hydrolysis 2-Cyanopyridine Crystal face

Effects of potassium promoter on the performance of PdCl_2–CuCl_2/AC catalysts for the synthesis of dimethyl carbonate from CO and methyl nitrite

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Chinese Chemical Letters 2015年第11期26卷 1359-1363页

作者： Sheng-Ping Wang Wei Li yuan-yuan Dong yu-jun zhao Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and Technology Tianjin University Collaborative Innovation Center of Chemical Science and Engineering

The effect of potassium （K） promoter on the catalytic performance of activated carbon （AC） supported Wacker-type catalysts （PdCl2-CuCl2/AC） for the synthesis of dimethyl carbonate （DMC） from CO and methyl nitrite （MN） was investigated by means of N2 adsorption, H2-temperature-programmed reduction （H2-TPR）, and X-ray photoelectron spectroscopy （XPS）. The experimental results showed that the space time yield of DMC on Wacker-type catalysts with different K promoters ranked in the following order： KCI 〉 KOH 〉 CH3COOK 〉 K2CO3. Especially, the addition of KCI significantly improved the catalytic activities of PdCl2-CuCl2/AC catalyst for DMC synthesis from CO and MN. N2 adsorption data indicated that the addition of K promoters did not change the textural properties of Wacker-type catalysts greatly. H2-TPR and XPS results demonstrated that the existence of KCI promoted the reducibility of Cu2＋ species and increased the proportion of Cu2＋ species on catalyst surface, which is favorable for oxidizing Pd0 to active Pd2＋. Further, the addition of KCI benefited the reactivity of PdCI2- CuCl2/AC catalwt for DMC synthesis from CO and MN.

关键词： Dimethyl carbonateWacker-type catalystActivated carbonPotassium promoterMethyl nitrite

Highly active Pd-Fe/α-Al_(2)O_(3) catalyst with the bayberry tannin as chelating promoter for CO oxidative coupling to diethyl oxalate

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Chinese Chemical Letters 2021年第2期32卷 796-800页

作者： Wei-Chao Xing Ji-Min An Jing Lv Faisal Irshad yu-jun zhao Sheng-Ping Wang Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China

A novel Pd-Fe/α-Al_(2)O_(3) catalyst was synthesized by incipient-wetness impregnation method with bayberry tannin as chelating promoter and commercial hollow column Raschig ring a-Al_(2)O_(3) as support for the synthesis of diethyl oxalate from CO and ethyl nitrite.A variety of characterization techniques including N2 physical adsorption,optical microscopy,scanning electron microscopy and energy dispersive system(SEM-EDS),inductively coupled plasma optical emission spectroscopy(ICP-OES),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),were employed to explore the relationship between the physicochemical properties and activity of catalysts.It indicated that a large number of phenolic hydroxyl groups in bayberry tannin can efficiently anchor the active component Pd,reduce the particle size and make the active Pd as a multi-ring distribution on the commercial a-Al2O3 suppo rt,which we re beneficial to improve the catalytic activity for the production of diethyl oxalate from CO and ethyl nitrite.0.3 wts Pd-Fe/α-Al_(2)O_(3) showed excelle nt catalytic activity and selectivity in a continuous flow,fixed-bed reactor with the loading amount of 10 mL catalysts,Under the mild reaction conditions,the space-time yield of diethyl oxalate was 978 g L^(-1) h^(-1) and CO conversion was 44% with the selectivity to diethyl oxalate of 95.5%.

关键词： Bayberry tannin Diethyl oxalate Phenolic hydroxyl groups Ethyl nitrite Pd-Fe/α-Al_(2)O_(3)

Tailoring microstructure and electrical transportation through tensile stress in Bi_(2)Te_(3) thermoelectric fibers

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Journal of Materiomics 2020年第3期6卷 467-475页

作者： Min Sun Guowu Tang Bowen Huang Zhongjia Chen yu-jun zhao Hanfu Wang Ziwen zhao Dongdan Chen Qi Qian Zhongmin Yang School of Physics and Optoelectronics South China University of TechnologyGuangzhou510640China State Key Laboratory of Luminescent Materials and Devices Institute of Optical Communication MaterialsGuangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and DevicesGuangdong Provincial Key Laboratory of Fiber Laser Material and Applied TechniquesSouth China University of TechnologyGuangzhou510640China CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology of ChinaBeijing100190China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai Institute for Advanced Communication and Data ScienceSchool of Communication and Information EngineeringShanghai UniversityShanghai200072China

Bismuth telluride(Bi_(2)Te_(3))has attracted much attention in the field of thermoelectrics since it is one kind of commercial room-temperature thermoelectric material.Herein three kinds of Bi_(2)Te_(3) thermoelectric fibers with internal tensile stress are fabricated utilizing an optical fiber template method.The effects of internal stress on the microstructure and the electrical transportation of Bi_(2)Te_(3) thermoelectric fibers are investigated.The Bi_(2)Te_(3) cores in the fibers are highly crystalline and possess a tensile nanosheet structure with preferential orientation as evidenced by X-ray diffraction and Raman studies.Tensile stress can enhance electrical properties of the fibers.And a paper cup generator covered with 20 pieces of optimized fibers provides a μW-level output power.It is inferred that tensile stress tuning can be an effective tool for the material optimization of thermoelectric performance.

关键词： Bi_(2)Te_(3) Thermoelectric fiber Tensile stress Electrical transportation

Efficient degradation of aqueous dichloromethane by an enhanced microbial electrolysis cell:Degradation kinetics,microbial community and metabolic mechanisms

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Journal of Environmental Sciences 2024年第5期139卷 150-159页

作者： Meng Wu Di zhao Bing Gu ZiruWang jun Hu Zhiliang yu Jianming yu College of Environment College of Biotechnology and BioengineeringCollaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhou 310014China Shentuo Environment(Hangzhou)Co.Ltd. Hangzhou 311121China Zhejiang Tianyi Environmental Co.Ltd. Hangzhou 310000China

Dichloromethane(DCM)has been listed as a toxic and harmful water pollutant,and its re moval needs attention.Microbial electrolysis cells(MECs)are viewed as a promising alterna tive for pollutant removal,which can be strengthened from two aspects:microbial inocula tion and acclimation.In this study,the MEC for DCM degradation was inoculated with the ac tive sludge enhanced by Methylobacterium rhodesianum H13(strain H13)and then acclimated in the form of a microbial fuel cell(MFC).Both the introduction of strain H13 and the initi ation in MFC form significantly promoted DCM degradation.The degradation kinetics were fitted by the Haldane model,with V_(max),K_(h),K_(i)and v_(max)values of 103.2 mg/L/hr,97.8 mg/L268.3 mg/L and 44.7 mg/L/hr/cm^(2),respectively.The cyclic voltammogram implies that DCM redox reactions became easier with the setup of MEC,and the electrochemical impedance spectrogram shows that the acclimated and enriched microbes reduced the charge transfe resistance from the electrode to the electrolyte.In the biofilm,the dominant genera shifted from Geobacter to Hyphomicrobium in acclimation stages.Moreover,Methylobacterium played an increasingly important role.DCM metabolism mainly occurred through the hydrolytic glutathione S-transferase pathway,given that the gene dcmA was identified rather than the dhlA and P450/MO.The exogenous electrons facilitated the reduction of GSSG,directly o indirectly accelerating the GSH-catalyzed dehalogenation.This study provides support fo the construction of an efficient and stable MEC for DCM removal in water environment.

关键词： Dichloromethane Microbial electrolysis cells Metabolic pathways Electron transfer Degradation kinetics

Progress and prospects of chiral nanomaterials for biosensing platforms

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Rare Metals 2024年第6期43卷 2469-2497页

作者： yu-Cheng Ouyang Bong-jun Yeom yuan zhao Wei Ma School of Food Science and Technology State Key Laboratory of Food Science and ResourcesJiangnan University Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan University Department of Chemical Engineering Hanyang University

Chiral nanomaterials have distinct chiroptical properties of preferential interactions to circularly polarized lights.Chirality-based biosensors have emerged for detection of biomolecules,ions and cells in recent years.This review provides an extensive overview of biosensors based on chiral nanomaterials,starting with approaches to chiral nanomaterials construction in terms of fabrication strategies.Fabrication of chiral nanomaterials and their biosensor applications is presented for different material types,with special emphasis on the role and importance of material properties and signal generation in detection.We assessed the technological prospects of the emerging fields of chiral construction,circularly polarized luminescence,Raman optical activity and so on along with their current challenges.Prospective venues for future research on chiral nanomaterials in fabrication,biosensing,disease diagnosis and treatment are also presented in the review.

关键词： Chiral nanomaterials Circular dichroism Biosensors

Caseinolytic mitochondrial matrix peptidase X is essential for homologous chromosome synapsis and recombination during meiosis of male mouse germ cells

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Asian Journal of Andrology 2024年第2期26卷 165-174页

作者： Hai-Wei Feng yu zhao Yan-Ling Gao Dong-Teng Liu Li-jun Huo Key Laboratory of Agricultural Animal Genetics Breeding and ReproductionEducation Ministry of ChinaCollege of Animal Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China Shenzhen Key Laboratory of Fertility Regulation Reproductive Medicine CenterThe University of Hong Kong-Shenzhen HospitalShenzhen 518053China Maternal-Fetal Medicine Institute Department of Obstetrics and GynaecologyShenzhen Baoan Women's and Children's HospitalJinan UniversityShenzhen 518100China Department of Obstetrics and Gynaecology Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong SARChina

Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various proteins.The mitochondrial protease complex(ClpXP),which consists of caseinolytic mitochondrial matrix peptidase X(ClpX)and caseinolytic protease P(ClpP)and mediates the degradation of misfolded,damaged,and oxidized proteins,is essential for maintaining mitochondrial homeostasis.ClpXP has been implicated in meiosis regulation,but its precise role is currently unknown.In this study,we engineered an inducible male germ cell-specific knockout caseinolytic mitochondrial matrix peptidase X(Clpx^(cKO))mouse model to investigate the function of ClpX in meiosis.We found that disrupting Clpx in male mice induced germ cell apoptosis and led to an absence of sperm in the epididymis.Specifically,it caused asynapsis of homologous chromosomes and impaired meiotic recombination,resulting in meiotic arrest in the zygotene-to-pachytene transition phase.The loss of ClpX compromised the double-strand break(DSB)repair machinery by markedly reducing the recruitment of DNA repair protein RAD51 homolog 1(RAD51)to DSB sites.This dysfunction may be due to an insufficient supply of energy from the aberrant mitochondria in Clpx^(cKO) spermatocytes,as discerned by electron microscopy.Furthermore,ubiquitination signals on chromosomes and the expression of oxidative phosphorylation subunits were both significantly attenuated in Clpx^(cKO) spermatocytes.Taken together,we propose that ClpX is essential for maintaining mitochondrial protein homeostasis and ensuring homologous chromosome pairing,synapsis,and recombination in spermatocytes during meiotic prophase I.

关键词： ClpX homologous chromosome meiosis mitochondrial recombination synapsis

Cloning and Expression Analysis of Two Dehydrodolichyl Diphosphate Synthase Genes from Tripterygium wilfordii

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World Journal of Traditional Chinese Medicine 2018年第1期4卷 15-20页

作者： Lin-Hui Gao Ping Su Yi-Feng Zhang Li-Chan Tu yu-jun zhao Tian-yuan Hu Jia-Wei Zhou Bao-Wei Ma Wei Gao Lu-Qi Huang School of Traditional Chinese Medicine Capital Medical University State Key Laboratory of Breeding Base Dao-di Herbs National Resource Center for Chinese Materia Medical China Academy of Chinese Medical Sciences Beijing Key Laboratory of Traditional Chinese Medicine Collateral Disease Theory Research Capital Medical University

Objective: To clone and investigate two dehydrodolichyl diphosphate synthase genes of Tripterygium wilfordii by bioinformatics and tissue expression analysis. Materials and Methods: According to the T. wifordii transcriptome database, specific primers were designed to clone the TwDHDDS1 and TwDHDDS2 genes via PCR. Based on the cloned sequences, protein structure prediction, multiple sequence alignment and phylogenetic tree construction were performed. The expression levels of the genes in different tissues of T. wilfordii were measured by real?time quantitative PCR. Results: The TwDHDDS1 gene encompassed a 873 bp open reading frame(ORF) and encoded a protein of 290 amino acids. The calculated molecular weight of the translated protein was about 33.46 kDa, and the theoretical isoelectric point(pI) was 8.67. The TwDHDDS2 encompassed a 768 bp ORF, encoding a protein of 255 amino acids with a calculated molecular weight of about 21.19 kDa, and a theoretical isoelectric point(pI) of 7.72. Plant tissue expression analysis indicated that TwD HDDS1 and TwDHDDS2 both have relatively ubiquitous expression in all sampled organ tissues, but showed the highest transcription levels in the stems. Conclusions: The results of this study provide a basis for further functional studies of TwDHDDS1 and TwDHDDS2. Most importantly, these genes are promising genetic targets for the regulation of the biosynthetic pathways of important bioactive terpenoids such as triptolide.

关键词： Bioinformatic analysis expression analysis Tripterygium wilfordii TwDHDDS gene