检索结果-南通市图书馆

Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： yi-Cong Wang Hui Zhat Pei-yi cheng Shu Zhang Xiang-Wei Liu yi-Xian wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Corrosion behavior of additive-manufactured NiFeCrMo alloys in various corrosion media

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第8期30卷 1574-1585页

作者： Dong-peng Wang Shuai Wang Zhen Chen Xing-cheng Xie Zhen-zhen Dong Hong-zhou Dong yi-cheng wu Zhen-guang Liu Wei-li Li Yu-xin Wang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina GRIMAT Engineering Institute Co. Ltd.Beijing 101407China GRINM(Guangdong)Institute for New Advanced Materials and Technology Dongguan 528041GuangdongChina School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina

To understand the corrosion performance of additive-manufactured Ni-based in various corrosion media during the actual engineering application environment,the corrosion properties of NiFeCrMo alloys were investigated in 3.5 wt.%NaCl solution,1 mol/L H2SO_(4) solution,and 1 mol/L KOH solution,using potentiodynamic polarization and electrochemical impedance *** electrochemical measurement results revealed that the additive-manufactured NiFeCrMo alloys have higher corrosion resistance in all three solutions,compared with the as-cast *** results of the scanning electron microscope confirmed that the degree of additive-manufactured NiFeCrMo alloys after potentiostatic polarization in all three solutions is less serious.X-ray photoelectron spectroscopy analysis revealed that the enhancement of the corrosion resistance for the additive-manufactured NiFeCrMo alloys is attributed to the modification of the composition of the passive *** manufactured processing promotes the enrichment of the element of Cr or Mo in the passive film and it suppresses the formation of the oxidation of the element of Fe,leading to higher stability of the passive *** reason for the higher corrosion resistance of the additive-manufactured NiFeCrMo alloys was related to the enrichment of the element of Cr,as well as the lower content of the elements of Ni and Fe near the grain boundaries,which are beneficial to forming a more compact passive *** combined results are essential for the applications of high-strength Ni-based as structural materials in a corrosion environment.

关键词： Ni-based alloy Additive manufacturing Corrosion Passive film Corrosion media

The Functional Redundancy of Neddylation E2s and E3s in Modulating the Fitness of Regulatory T Cells

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 373-387页

作者： Di wu yi Sun Cancer Institute(Key Laboratory of Cancer Prevention and Intervention China National Ministry of Education)of the Second Affiliated Hospital and Institute of Translational MedicineZhejiang University School of MedicineHangzhou 310029China Cancer Center of Zhejiang University Hangzhou 310029China Zhejang Provincial Clinical Research Center for Cancer Zhejang ProvinceChina Key Laboratory of Molecular Biology in Medical Sciences Zhejang ProvinceChina Research Center for Life Science and Human Health Binjiang Institute of Zhejiang UniversityHangzhou 310053China

Neddylation is necessary for activation of Cullin-RING ligases(CRLs),which degrade various immune regulatory *** recent study showed that while depletion of neddylation E2-E3 pair Ube2f-Sag in regulatory T(T_(reg))cells had no obvious phenotype,the same depletion of either Ube2m or Rbx1 caused inflammation disorders with different *** these E2s or E3s compensate each other in functional regulations of T_(reg)cells is,however,previously *** this report,we generated Foxp3^(Cre);Ube2m^(fl/fl);Ube2f^(fl/fl)or Foxp3^(Cre);Rbx1^(fl/fl);Sag^(fl/fl)double-null mice by simultaneous deletion of both neddylation E2s or E3s in T_(reg)cells,***,Ube2m&Ube2f double-null mice developed much severe autoimmune phenotypes than did Ube2m-null mice,indicating that Ube2m markedly compensates Ube2f in T_(reg)*** minor worsened autoimmune phenotypes seen at the very early stage in Rbx1&Sag double-null than Rbx1-null mice is likely due to already severe phenotypes of the later,indicating a minor compensation of Rbx1 for *** RNA profiling-based analyses revealed that up-and down-regulations of few signaling pathways in T_(reg)cells are associated with the severity of autoimmune ***,severer inflammation phenotypes seen in mice with double E3-null than with double E2-null T_(reg)cells indicate a neddylation-independent mechanism of 2 E3s,also known to serve as the RING component of CRLs in regulation of T_(reg)cell fitness.

关键词： Foxp3 inflammation markedly

Establishment of genome-editing system and assembly of a near-complete genome in broomcorn millet

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第8期66卷 1688-1702页

作者： Yang Liu Zixiang cheng Weiyao Chen Chuanyin wu Jinfeng Chen yi Sui State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoologythe Chinese Academy of SciencesBeijing 100101China State Key Laboratory of Crop Gene Resources and Breeding Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China

The ancient crop broomcorn millet(Panicum miliaceum L.)is an indispensable orphan crop in semi-arid regions due to its short life cycle and excellent abiotic stress *** advantages make it an important alternative crop to increase food security and achieve the goal of zero hunger,particularly in light of the uncertainty of global climate ***,functional genomic and biotechnological research in broomcorn millet has been hampered due to a lack of genetic tools such as transformation and genome-editing ***,we successfully performed genome editing of broomcorn *** identified an elite variety,Hongmi,that produces embryogenic callus and has high shoot regeneration ability in in vitro *** established an Agrobacterium tumefaciens-mediated genetic transformation protocol and a clustered regularly interspaced short palindromic repeats(CRISPR)/Cas9-mediated genome-editing system for *** these techniques,we produced herbicide-resistant transgenic plants and edited phytoene desaturase(Pm PDS),which is involved in chlorophyll *** facilitate the rapid adoption of Hongmi as a model line for broomcorn millet research,we assembled a near-complete genome sequence of Hongmi and comprehensively annotated its ***,our results open the door to improving broomcorn millet using biotechnology.

关键词： broomcorn millet CRISPR/Cas9 editing genome assembly herbicide resistance transformation system

Chemokine platelet factor 4 accelerates peripheral nerve regeneration by regulating Schwann cell activation and axon elongation

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第1期19卷 190-195页

作者： Miao Gu Xiao cheng Di Zhang Weiyan wu yi Cao Jianghong He Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education Co-innovation Center of NeuroregenerationNMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongJiangsu ProvinceChina School of Basic Medical Sciences Hebei Key Laboratory of Nerve Injury and RepairChengde Medical UniversityChengdeHebei ProvinceChina

Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and *** r,it is unclear what factors play a role in this *** this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve *** factor is an important molecule in cell apoptosis,diffe rentiation,survival,and ***,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after ***-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann *** also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon ***,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic *** findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon ***,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.

关键词： axon elongation bioinformatic analysis cell migration cell proliferation dorsal root ganglia peripheral nerve regeneration peripheral nerve trauma platelet factor 4 rat sciatic nerve Schwann cells

Regulating electrochemical performances of lithium battery by external physical field

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2391-2417页

作者： Shi-Kang Wang Shuai wu yi-cheng Song Hassanien Gomaa Cui-Hua An Qi-Bo Deng Ning Hu School of Mechanical Engineering School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200444China Department of Chemistry Faculty of ScienceAl-Azhar UniversityAssiut 71524Egypt Tianjin Key Laboratory of Power Transmission and Safety Technology for New Energy Vehicles Tianjin 300401China State Key Laboratory of Reliability and Intelligence Electrical Equipment Key Laboratory of Advanced Intelligent Protective Equipment TechnologyMinistry of EducationHebei University of TechnologyTianjin 300130China

Lithium batteries have always played a key role in the field of new energy ***,non-controllable lithium dendrites and volume dilatation of metallic lithium in batteries with lithium metal as anodes have limited their ***,a large number of studies have shown that the electrochemical performances of lithium batteries can be enhanced through the regulation of external physical ***,it significantly hinders the growth of lithium dendrites and promoting the reaction *** review summarizes recent innovations in the investigation of various physical fields of lithium *** application of magnetic field in the synthesis of lithium battery electrode materials is *** influence factors and regulation mechanism of various physical fields on the electrochemical performance of lithium batteries are reviewed *** addition,the current research status and existing challenges,along with future directions for the evolution of lithium batteries,are minutely discussed and *** strategies for the further evolution of lithium batteries have also been provided.

关键词： Lithium battery External field assist Reaction kinetics Lithium dendrite

Corrosion behavior of Al_(2)O_(3)-C bricks in MnO-containing mold slag

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1486-1492页

作者： yi-jiang Zhao Guang-qiang Li Yang wu cheng Yuan Ze Meng Xiao-xuan Deng Yu Liu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Research Institute of Technology Shougang Group Co.Ltd.Beijing 100043China

In order to explore the corrosion mechanism of Al_(2)O_(3)-C refractories in the mold flux bearing MnO,the immersion test of Al_(2)O_(3)-C refractories in CaO-SiO2-CaF2-MnO slag with different MnO contents was carried out at 1550℃.The results show that Mn particles were observed in the slag after experiment,due to the reduction of MnO by graphite in *** amounts of graphite were observed at the interface between refractories and slag,indicating that the oxidation of graphite is limited by the poor contact between graphite and molten ***,the oxidation of graphite is not the main cause of damage to refractories.A small quantity of CaO·2Al_(2)O_(3)(CA_(2))and CaO·6Al_(2)O_(3)(CA_(6))adjacent to Al_(2)O_(3) grain was detected at the slag/reaction layer ***_(2) and CA_(6) possess relatively high melting points,which is beneficial to hindering the further penetration of ***,the dissolution of Al_(2)O_(3) into slag is still the main cause for refractories *** increase in the MnO content of mold slag decreases the viscosity and then results in the severe corrosion of Al_(2)O_(3)-C bricks.

关键词： Al_(2)O_(3)-C refractory MnO-containing slag Graphite Corrosion

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang wu Mingyu wu Yongfu Sun yi Xie Hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

High-power ultraviolet 278-nm laser from fourth-harmonic generation of an Nd：YAG amplifier in CsB3O5 crystal

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第5期27卷 265-269页

作者： Miao He Feng Yang cheng Dong Zhi-Chao Wang Lei Yuan yi-Ting Xu Guo-Chun Zhang Zhi-Min Wang Yong Bo Qin-Jun Peng Da-Fu Cui yi-cheng wu Zu-Yan Xu Key Laboratory of Solidstate Laser Technical Institute of Physics and Chemistry (TIPC) Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Functional Crystal and Laser Technology TIPC Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

We report on the experimental investigation and theoretical analysis of a nanosecond pulse high power ultraviolet（UV） 278 nm laser by fourth-harmonic generation（FHG） of a 1112-nm Nd：YAG amplifier in LiB3O5（LBO） and CsB3O5（CBO） crystals. The UV laser delivers a maximum average power of 10.3 W at 278 nm with peak power of 36.8 k W under input pump power of 41 W at 556 nm. This is, to the best of our knowledge, the highest output power at the specific UV wavelength of 278 nm. We also performed the theoretical investigation on the FHG with a model in the Gaussian approximation of both spatial and temporal profiles, especially accounting for the two-photon absorption effect in CBO crystal for the first time. The average output power, pulse width, and beam spatial distribution of the UV laser were simulated. The theoretical calculations are in close agreement with the experimental results.

关键词： ultraviolet lasers frequency doubled CsB3O5(CBO)crystal two-photon absorption