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Water-based lubrication of niobium nitride

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Friction 2022年第6期10卷 842-853页

作者： Kaifei MIAO jia WANG Qiang ZHAO Kaiwen WANG mao WEN Kan ZHANG State Key Laboratory of Superhard Materials Department of Materials ScienceKey Laboratory of Automobile MaterialsMOEJilin UniversityChangchun 130012China Department of Materials Science and Engineering Jilin Jianzhu UniversityChangchun 130118China

Water-based lubrication has attracted wide attention as an oil-free lubrication method owing to its greener and cleaner lubrication ***,due to operating in the water environment,most moving parts would inevitably suffer from abrasion,rusting,and aging *** a novel solid-water composite system with ultra-low friction and wear will open new possibilities for innovative lubrication material research and ***,we first revealed the water-based lubrication behavior of a high-hardness niobium nitride coating(NbN).In a three-phase contact environment(water,air,and NbN),oxidation and hydrolytic reactions of NbN result in the formation of"colloidal solutions",containing Nb_(2)O_(5)colloidal particles between the *** the double electric layer repulsion and weak shear action of the"colloidal solution",NbN achieves ultra-low friction and wear;the corresponding values are as low as 0.058 and 1.79×10^(-10)mm^(3)·N^(-1)·m^(-1),*** addition,other VB transition metal nitrides(VB TMNs)exhibit the same low friction feature as NbN in the three-phase contact environment;the friction coefficients are even lower than those in an oil-based *** water-based lubrication of VB TMNs provides a new reliable scheme for optimizing solid-water composite lubrication systems without additives and is expected to be applied in environments with high humidity or insufficient water coverage.

关键词： NbN water-based lubrication ultra-low friction ultra-low wear

INFLUENCE OF STRUCTURE ON HYDRAULIC CHARACTERISTICS OF T SHAPE FISHWAY

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Journal of Hydrodynamics 2012年第5期24卷 684-691页

作者： mao Xi FU Jing-jing TUO You-cai AN Rui-dong LI jia State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065China HydroChina Hua Dong Engineering Corp.9 Hangzhou 310014 China

While dams cut off the migratory route of fish, and affect their growth and breeding, fishways are built to restore the con- nectivity of rivers and facilitate the life cycle of these migratory fish. This paper proposes a new kind of fishway called the ＂T shape fishway＂, and studies it by using both numerical simulations and physical experimental methods with the aim to design a fishway in China for migratory fish with swimming and jumping capability much poorer, such as schizothorax davidi and schizothorax prenanti, as compared with migratory fish in other places of the world, like trout and salmon. It is indicated that the range of velocity in each regular pool of the T shape fishway is from 0.42 m/s to 1.22 m/s when the flow discharge Q is 350 L/s, and there are no large vortex zones found there. This study shows that the T shape fishway can meet the requirements of these migratory fish quite well in terms of velocity and flow patterns in China.

关键词： fishway migratory fish baffle drop sill numerical simulation experiment

Topology of Current-limiting and Energy-transferring DC Circuit Breaker for DC Distribution Networks

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CSEE Journal of Power and Energy Systems 2020年第2期6卷 298-306页

作者： Song tang Min Chen Guanlong jia Chenghao Zhang School of Electrical Engineering Zhejiang UniversityHangzhouChina

With the development of power electronic technologies and distributed power generation,DC distribution networks attract increasing attention due to their various advantages compared with traditional AC distribution ***,DC fault protection is one of the major issues in DC distribution *** improve their reliability and protect the semiconductor devices under DC faults,a current-limiting and energy-transferring DC circuit breaker topology is proposed in this *** applying passive components and thyristors,the proposed topology is capable of quickly limiting the fault current and transferring the faulty *** working principle,mathematical model and parameter designing method of the proposed topology are presented in this *** simulation results verify that the proposed DC circuit breaker could effectively limit the fault current and quickly interrupt the fault *** and conduction power loss evaluation proves the practicality of the proposed topology in medium-voltage DC distribution networks.

关键词： DC distribution network energy transfer fault current limiting hybrid DC circuit breaker passive components

Single Molecule Imaging with Liquid Phase Electron Microscopy

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Chinese Journal of Chemistry 2023年第6期41卷 679-684页

作者： jia-Ye Li De-Yi Zhang Sheng mao Huan Wang College of Chemistry and Molecular Engineering Bejing National Laboratory for Molecular SciencesCenter for SpectroscopyBejing Key Laboratory of Polymer Chemistry&Physics of Ministry of EducationCenter for Soft Matter Science and EngineeringNational Biomedical Imaging CenterPeking UniversityBeijing 100871China Department of Mechanics and Engineering Sciences College of EngineeringPeking UniversityBejing 100871China

Few single-molecule experiments have enabled the direct imaging of functional biomacromolecules in real-time in their native liquid environments,resolving their conformational adaptations,transient interactions,and intermediate *** phase electron microscopy(LP-EM),due to its unique combination of spatial and temporal resolution,has shown to be a promising *** experiments have enabled successful imaging of intact structures of organic molecules and biological systems with an ordinary electron *** image processing methods and quantitative data analysis from single particle experiments based on the optical microscope,quantifying motion and relaxation of these interacting molecules allows the experimental observations of pathways,to test theoretical predictions,and discovery of new *** LP-EM with tomography,fluorescence,and mass spectroscopy allows for probing multi-dimensional structural and dynamic *** remain in obtaining high-quality data in large quantities,which can be improved by developing new liquid cell platforms and machine learning-based data analysis.

关键词： Single-molecule studies Direct Imaging Liquid-phase electron microscopy Analytical methods Image analysis

An encapsulated optical microsphere sensor for ultrasound detection and photoacoustic imaging

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Science China(Physics,Mechanics & Astronomy) 2022年第2期65卷 44-49页

作者： jialve Sun jia-Wei Meng Shui-Jing tang Changhui Li Department of Biomedical Engineering College of EngineeringPeking UniversityBeijing 100871China ~State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter School of PhysicsPeking UniversityBeijing 100871China College of Future Technology Peking UniversityBeijing 100871

Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity *** the last decade,ultrasonic sensors with on-chip microcavities have been extensively developed;however,they are unsuitable for the near-field photoacoustic microscopy of micro/nanoscale objects in complex biological environments and endoscopic *** this work,we developed ultrasonic sensors using two types of encapsulated microsphere resonators with different cavity materials.A noise equivalent pressure of as low as 160 Pa at 20 MHz was achieved with the acoustic response up to 70 MHz at-6 d ***,the microsensor was used for photoacoustic microscopy in which we successfully performed 3 D imaging of hairs and leaf *** microsphere ultrasonic sensor has considerable potential as a probe-type ultrasonic detector for near-field photoacoustic microscopy of micro/nanoscale objects such as subcellular structures and high-resolution endoscopic photoacoustic imaging with its high sensitivity and wide bandwidth.

关键词： optical whispering gallery micro-resonators ultrasound sensing photoacoustic imaging

On microbial community of Pyropia haitanensis by metagenomic analysis

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Journal of Oceanology and Limnology 2021年第3期39卷 1091-1102页

作者： Junhao WANG Yunxiang mao Guoying DU Xiaojiao LI Xianghai tang Key Laboratory of Marine Genetics and Breeding(Ministry of Education) College of Marine Life SciencesOcean University of ChinaQingdao 266003China Key Laboratory of Utilization and Conservation of Tropical Marine Bioresource(Ministry of Education) College of Fisheries and Life ScienceHainan Tropical Ocean UniversitySanya 572022China

Microorganisms plays an important role in the growth of Pyropia *** understand the structural and functional diversity of the microorganism community of ***(PH40),the associated metabolic pathway network in cluster of orthologous groups(COG)and Kyoto Encyclopedia of Genes and Genomes(KEGG),and carbohydrate-active enzymes(CAZymes)were explored in metagenomic *** extraction from gametophytes of *** was performed first,followed by library construction,sequencing,preprocessing of sequencing data,taxonomy assignment,gene prediction,and functional *** results show that the predominant microorganisms of *** were bacteria(98.98%),and the phylum with the highest abundance was Proteobacteria(54.64%),followed by Bacteroidetes(37.92%).Erythrobacter(3.98%)and Hyunsoonleella jejuensis(1.56%)were the genera and species with the highest abundance of bacteria,*** COG annotation demonstrated that genes associated with microbial metabolism was the predominant *** results of metabolic pathway annotation show that the ABC transport system and two-component system were the main pathways in the microbial *** growth hormone biosynthesis pathway and multi-vitamin biosynthesis functional units(modules)were the other important *** CAZyme annotation revealed that the starch might be an important carbon source for *** transferase family 2(GT2)and glycosyl transferase family 3(GT3)were the highly abundant families in glucoside transferase *** metagenome-assembled genomes containing enzymes involved in the biosynthesis of cobalamin(vitamin B 12)and indole-3-acetic acid were obtained by binning *** were confirmed to belong to Rhodobacterales and Rhizobiales,*** findings provide comprehensive insights into the microorganism community of Pyropia.

关键词： P.haitanensis metagenomic microbial community cluster of orthologous groups(COG) Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways carbohydrate-active enzymes(CAZymes)

Microstructure and mechanical properties of WMoTaNbTi refractory high-entropy alloys fabricated by selective electron beam melting

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Journal of Materials Science & Technology 2022年第13期108卷 54-63页

作者： Bang Xiao Wenpeng jia Huiping tang jian Wang Lian Zhou State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Porous Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China

WMoTaNbTi RHEAs formed by SEBM with negative defocus distance were *** scanning speeds were applied,an electron beam with scanning speed at 2.5 m/s completely fused the premixed WMoTaNb alloyed powder and pure Ti *** vaporization of Nb and Ti elements happened during the formation of WMoTaNbTi RHEAs,however,the single BCC phase remains *** solid-solute strengthening caused by elemental vaporization,dropping percentage of Nb and Ti solutes in the matrix as well as improved ductilizing effects with decreasing scanning speeds leads to falling microhardness and better local *** of scanning speed at 4.0 m/s,3.5 m/s,3.0 m/s and 2.5 m/s is 578±17 HV,576±12 HV,573±10 HV and 511±2 HV,*** as-deposited WMoTaNbTi RHEA formed at a scanning speed of 2.5 m/s displays ultimate strength of 1312 MPa.

关键词： Refractory high-entropy alloys Selective electron beam melting Solidification cracking Porosity Solid-solution strengthening

The RNA N^(6)-methyladenosine demethylase ALKBH9B modulates ABA responses in Arabidopsis

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Journal of Integrative Plant Biology 2022年第12期64卷 2361-2373页

作者： Jun tang Junbo Yang Qiang Lu Qian tang Shuyan Chen Guifang jia Synthetic and Functional Biomolecules Center Bejing National Laboratory for Molecular SciencesKey Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationDepartment of Chemical BiologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Peking-Tsinghua Center for Life Sciences Beijing 100871China

The mRNA modification N^(6)-methyladenosine(m^(6)A)plays vital roles in plant development and biotic and abiotic stress *** RNA m^(6)A demethylase ALKBH9 B can remove m^(6)A in alfalfa mosaic virus RNA and plays roles in alfalfa mosaic virus infection in ***,it is unknown whether ALKBH9 B also exhibits demethylation activity and has a biological role in endogenous plant *** demonstrated here that mRNA m^(6)A modification is induced by the phytohormone abscisic acid(ABA)and that ALKBH9 B has m^(6)A demethylation activity on endogenous *** out ALKBH9 B led to hypersensitivity to ABA treatment during seed germination and early seedling *** further showed that ALKBH9 B removes the m^(6)A modification in the ABA INSENSITIVE 1(ABI1)and BRI1-EMS-SUPPRESSOR 1(BES1)transcripts following ABA treatment,affecting the stability of these ***,we determined that ALKBH9 B acts genetically upstream of the transcription factors ABI3 and ABI5,and its regulatory function in ABA responses depended on ABI3 and *** findings reveal the important roles of the m^(6)A modification in ABA responses and highlight the role of ALKBH9 Bmediated m^(6)A demethylation in regulating ABA responses post-transcriptionally.

关键词： ABA ALKBH9B Arabidopsis demethylase m^(6)A RNA modification

The capacitive performances of carbon obtained from the electrolysis of CO_(2) in molten carbonates: Effects of electrolysis voltage and temperature

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Journal of Energy Chemistry 2020年第12期29卷 418-424页

作者： Diyong tang Yanpeng Dou Huayi Yin Xuhui mao Wei Xiao Dihua Wang School of Resource and Environmental Sciences International Cooperation Base for Sustainable Utilization of Resources and Energy in Hubei ProvinceWuhan UniversityWuhan 430072HubeiChina

The electrochemical reduction of CO2 to capacitive carbon in molten Li2 CO3–Na2 CO3–K2 CO3 is an effective strategy for capturing and utilizing CO2. This paper reports the effects of the cell voltages and operating temperatures(450–650 °C) of the molten salt electrolysis on the capacitive performance of electrolytic carbon. The electrolytic carbon delivers excellent specific capacitance when the cell voltage is 4.5 V and the temperature of molten salt is 450 °C. The carbon obtained at 450 °C and under 4.5 V delivers a specific capacitance of 550 F g^(-1) at 0.2 A g^(-1) in 1 M aqueous H2 SO4, and the capacity retention rate is73% after 10000 cycles. The specific capacitance of the electrolytic carbon increases as the electrolysis temperature decreases, and the optimal cell voltage is 4.5 V.

关键词： Carbon dioxide Electrochemical conversion Molten carbonates Carbon Supercapacitor