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14篇 您的检索式:作者名="Zhenjing Li"
    题名 作者 年代 出处 被引量
1Milling surface roughness for 7050 aluminum alloy cavity influenced by nozzle position of nanofluid minimum quantity lubrication显示文摘In nanofluid minimum quantity lubrication(NMQL)milling of aviation aluminum alloy,it is the bottleneck problem to adjust the position parameters(target distance,incidence angle,and elevation angle)of the nozzle to improve the surface roughness of milling,which has large and uncontrollable errors.In this paper,the influence law of milling cutter speed,helical angle,and cavity shape on the flow field around the milling cutter was studied,and the optimal nozzle profile parameters were obtained.Using 7050 aluminum alloy as the workpiece material,the milling experiment of the NMQL cavity was conducted by utilizing cottonseed oil-based Al2 O3 nanofluid.Results show that the high velocity of the surrounding air flow field and the strong gas barrier could be attributed to high rotating velocities of the milling cutter.The incidence angle of the nozzle was consistent with the helical angle of the milling cutter,the target distance was appropriate at 25–30 mm,and the elevation angle was suitable at 60°–65°.The range and variance analyses of the signal-to-noise ratio of milling force and roughness were performed,and the chip morphology was observed and analyzed.The results show that the optimal combination of nozzle position parameters was the target distance of 30 mm,the incidence angle of 35°,and the elevation angle of 60°.Among these parameters,target distance had the largest impact on cutting performance with a contribution rate of more than 55%,followed by incidence angle and elevation contribution rate.Analysis by orthogonal experiment revealed that the nozzle position parameters were appropriate,and Ra(0.087 lm)was reduced by 30.4%from the maximum value(0.125 lm).Moreover,Rsm(0.05 mm)was minimum,which was 36%lower than that of the seventh group(Rsm=0.078 mm).Zhenjing DUAN Changhe LI Yanbin ZHANG Lan DONG Xiufang BAI Min YANG Dongzhou JIA Runze LI Huajun CAO Xuefeng XU 2021Chinese Journal of Aeronautics2021,34,6:10
2Milling Force Model for Aviation Aluminum Alloy: Academic Insight and Perspective Analysis显示文摘Aluminum alloy is the main structural material of aircraft,launch vehicle,spaceship,and space station and is processed by milling.However,tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy.The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters,material mechanical properties,machine tools,and other parameters.In particular,milling force is the crucial factor to determine material removal and workpiece surface integrity.However,establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system.The research progress of cutting force model is reviewed from three modeling methods:empirical model,finite element simulation,and instantaneous milling force model.The problems of cutting force modeling are also determined.In view of these problems,the future work direction is proposed in the following four aspects:(1)high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth,which easily produces high residual stress.The residual stress should be analyzed under this particular condition.(2)Multiple factors(e.g.,eccentric swing milling parameters,lubrication conditions,tools,tool and workpiece deformation,and size effect)should be considered comprehensively when modeling instantaneous milling forces,especially for micro milling and complex surface machining.(3)The database of milling force model,including the corresponding workpiece materials,working condition,cutting tools(geometric figures and coatings),and other parameters,should be established.(4)The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling.(5)The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication(mql)and nanofluid mql should be predicted.Zhenjing Duan Changhe Li Wenfeng Ding Yanbin Zhang Min Yang Teng Gao Huajun Cao Xuefeng Xu Dazhong Wang Cong Mao Hao Nan Li Gupta Munish Kumar Zafar Said Sujan Debnath Muhammad Jamil Hafiz Muhammad Ali 2021Chinese Journal of Mechanical Engineering2021,34,1:7
3Maize MS2 encodes an ATP-binding cassette transporter that is essential for anther development显示文摘The anther cuticle and pollen exine play a critical role in male gametophyte development. The sporopollenin precursors and cuticular lipid monomers are transported to the surface of the microspores and the epidermis by lipid transport proteins(LTPs) and ATP-binding cassette G(ABCG) transporters for the formation of the pollen wall and anther cuticle, respectively. However, the function of ABCG transporters in maize anther development is unclear. Here, we cloned the MS2 gene from the maize male sterile2 mutant using map-based cloning and determined that it encodes an ABCG transporter. MS2 protein was experimentally confirmed to be located on the cell membrane. The quantitative real-time PCR(qRT-PCR)results showed that MS2 was ubiquitously expressed in all vegetative and reproductive tissues, whereas a high transcriptional level of MS2 was observed in anthers, especially at the young microspore stage. Gas chromatography-mass spectrometry(GC–MS) analysis showed decreased accumulation of cutin and wax components in ms2 anthers, indicating that MS2 plays a role in the transport of lipid molecules to anther cuticle and pollen exine. To our knowledge, MS2 is the first reported ABCG transporter gene that participates in anther development in maize.Qilong Xu Li Yang Dan Kang Zhenjing Ren Yunjun Liu 2021The Crop Journal2021,9,6:4
4Identification of Major Locus Bph35 Resistance to Brown Planthopper in Rice显示文摘An introgression line RBPH660,derived from wild rice Oryza rufipogon,showed stable resistance to brown planthopper(BPH).Segregation analysis indicated BPH resistance of RBPH660 was controlled by multiple genes/QTLs.By using the bulked segregant analysis(BSA)-seq method,two genomic regions harboring QTLs resistance to BPH were identified from 1.20 to 16.70 Mb on chromosome 4 and from 10.20 to 12.60 Mb on chromosome 9 in RBPH660,respectively.A major resistance locus,designated as Bph35 accounting for 51.27%of the phenotypic variation with a LOD score of 42.51,was mapped to the candidate region of chromosome 4 between In Del(insertion-deletion)markers PSM16 and R4 M13.For fine mapping of Bph35,one simple sequence repeat and three newly developed In Del markers were used to screen the recombinants.Finally,the Bph35 locus was delimited in the region from 6.28 to 6.93 Mb and there were 18 predicted protein-encoding genes with a total of 114 non-synonymous single nucleotide polymorphism(SNP)variant sites between the resistant and susceptible parents.Out of these genes,Os04 g0193950,encoding a putative NB-ARC(nucleotidebinding adaptor shared by APAF-1,R proteins and CED-4)and LRR(leucine-rich repeat)domain protein with nine non-synonymous SNP substitutions in its coding sequence regions,might be the candidate gene for Bph35.These findings would facilitate the map-based cloning of the Bph35 gene and development of resistant varieties against BPH in rice.ZHANG Yuexiong QIN Gang MA Qianqian WEI Minyi YANG Xinghai MA Zengfeng LIANG Haifu LIU Chi LI Zhenjing LIU Fang HUANG Dahui LI Rongbai 2020Rice science2020,27,3:3
5Differences between the metabolic profiles of decompensated and compensated cirrhosis patients with Hepatitis B virus infections under high-performance liquid chromatography-mass spectrometry显示文摘Yu Chen Zhiliang Xu Hongwei Kong Nan Chen Jing Chen Lina Zhou Feiling Wang Yuejiao Dong Shufa Zheng Zhenjing Chen Guowang Xu Lanjuan Li 2012Metabolomics2012,,5:1
6Expression profile of early responsive genes under salt stress in upland cotton (Gossypium hirsutum L)显示文摘Zhang X ZhenJ B Li Z H 2011Plant Mol Bioi Rep2011,29,:1
7Bidirectional Immunomodulatory Activities of Polysaccharides Purified From Pleurotus nebrodensis显示文摘Changlu Wang Haiyan Cui Yurong Wang Zhifang Wang Zhenjing Li Mianhua Chen Fengjuan Li 2014Inflammation2014,,1:1
8Heat and mass transfer model optimization and annual energy efficiency analysis for energy recovery indirect evaporative cooling显示文摘Indirect evaporative cooling(IEC)is a kind of high efficiency,energy-saving and environmental protection cooling technology,which has been widely used in data centers and other fields in recent years.In this paper,the optimized two-dimensional non-condensation state model of indirect evaporative cooling was proposed.Meanwhile the computer program was updated to solve the developed mathematical model under variable fresh air conditions.The optimized model was verified by the experimental data,and the maximum deviation was only 4.6%.Based on the modified model and the annual hourly meteorological parameters in Tianjin,China,it was analyzed the optimal heat transfer area of IEC used as fresh air pre-cooling unit under various air volumes to provide references for system design and equipment selection.Finally,taking an IEC-primary return air conditioning system of a gymnasium as an example,the hourly energy-saving effect of whole year was simulated by the developed IEC model.The simulation results showed that IEC could control the fresh air temperature below 27℃ and the moisture content below 18 g/kg throughout the year,and undertook 102.6% of the total fresh air cooling load.The findings are useful in future system optimization and design of IEC equipment.Qilong Liu Chunmei Guo Zhenjing Wu Yuwen You Yan Li 2022Building Simulation2022,15,7:0
9High uric acid model in Caenorhabditis elegans显示文摘To establish experimental high uric acid model in C.elegans.Hypoxanthine,adenine,xanthine,and uric acid were used to treat C.elegans and then hyperuricemic C.elegans was evaluated by allopurinol.Hyperuricemic C.elegans were obtained after normal worms were treated by xanthine(0.25 mg/mL,18 h).For hyperuricemic worms,there was a statistically significant increase in the uric acid level(p<0.001)and a lower drug damage(p>0.05).Moreover,the model was proved to keep a high uric acid level for up to 12 h.After given allopurinol(0.25 mg/mL,12 h),the uric acid of hyperuricemic C.elegans had a significant reduction by 15%.Furthermore,xanthine oxidase activity in hyperuricemic C.elegans showed a statistically significant increase(p<0.001),which resulted in a raised uric acid content.A high uric acid model with low drug damage and high efficiency and stability was established in C.elegans after simply xanthine treatment.Zhenjing Li Yibin Xue Nifei Wang Jingli Cheng Xiaoying Dong Qingbin Guo Changlu Wang 2019Food Science and Human Wellness2019,8,1:0
10Phlorizin alleviates deltamethrin-induced oxidative stress in brine shrimp Artemia显示文摘Deltamethrin(DEL),a commonly used pyrethroid pesticide,results in higher reactive oxygen species(ROS)levels in aquatic animals,which consequently unbalance the redox state.Phlorizin(PHL)is a flavonoid and a natural product promising to prevent or reduce pesticide-induced oxidative stress.Artemia is a micro-crustacean widely used in marine hatcheries and an experimental aquatic organism for environmental toxicology research.This research aimed to evaluate the toxicity of DEL on Artemia and the antioxidative effect of PHL against the toxicity.Results show that 0.08-mg/mL PHL exerted its antioxidative effects on hatching percentage of the cysts in 24-h incubation and on body length and survival rate of Artemia in 12-d culture.After 12-d culture,12-,24-,and 36-h DEL exposure showed significant drops in SOD,CAT,and GSH-Px enzyme activities,and significant increases in ROS and malondialdehyde(MDA)levels in Artemia(P<0.05).On the contrary,0.08-mg/mL PHL application improved the enzyme activities and decreased the ROS and MDA levels(P<0.05).Moreover,0.08-mg/mL PHL significantly increased mRNA expression levels of Cu/Zn SOD,CAT,GST,HO-1,NQO1,and Nrf2,and decreased mRNA expression level of Keap1 in the DEL-exposed Artemia(P<0.05).Therefore,DEL is toxic to Artemia,while PHL alleviates DEL-induced oxidative damage by possibly regulating the Nrf2signaling pathway.This study provided a theoretical basis for PHL to reduce pesticide-induced toxicity in aquatic animals.Dandan MA Qingli ZHOU Liying SUI Qingbin GUO Huanhuan LIU Honghe LIANG Zhenjing LI Zhongna SANG 2024Journal of Oceanology and Limnology2024,42,1:0
11Synthesis of hexagonal boron nitrides by chemical vapor deposition and their use as single photon emitters显示文摘Two-dimensional(2D)hexagonal boron nitride(hBN),due to its extraordinary thermal,chemical,and optical properties,has arisen as an enticing material for the research community to explore for various applications,including the use of site defects in hBN as single photon emitters(SPEs).In this review,we systematically summarize recent advanced strategies towards the controllable synthesis of 2D hBN using chemical vapor deposition,towards a full control of the domain size,orientation,morphology,layer number,and stacking order,etc.Moreover,we review the underlying mechanisms for single photon emission(SPE)in hBN and methods to selectively generate and tune the SPEs.Defects(e.g.,carbon substituted defects)are discussed for the potential use as emission sites.We finally give an outlook of future challenges and opportunities on desirable hBN synthesis and further investigation of SPEs in hBN,targeting to utilize hBN as single photon emitters in an industrial scale.Hongwei Liu Chae Young You Jingwei Li Patrick Ryan Galligan Jiawen You Zhenjing Liu Yuting Cai Zhengtang Luo 2021Nano Materials Science2021,3,3:0
12Low-temperature Denitration Mechanism of NH_(3)-SCR over Fe/AC Catalyst显示文摘To study the modification mechanism of activated carbon(AC)by Fe and the low-temperature NH_(3)-selective catalytic reduction(SCR)denitration mechanism of Fe/AC catalysts,Fe/AC catalysts were prepared using coconut shell AC activated by nitric acid as the support and iron oxide as the active component.The crystal structure,surface morphology,pore structure,functional groups and valence states of the active components of Fe/AC catalysts were characterised by X-ray diffraction,scanning electron microscopy,nitrogen adsorption and desorption,Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy,respectively.The effect of Fe loading and calcination temperature on the low-temperature denitration of NH_(3)-SCR over Fe/AC catalysts was studied using NH_(3)as the reducing gas at low temperature(150℃).The results show that the iron oxide on the Fe/AC catalyst is spherical and uniformly dispersed on the surface of AC,thereby improving the crystallisation performance and increasing the number of active sites and specific surface area on AC in contact with the reaction gas.Hence,a rapid NH_(3)-SCR reaction was realised.When the roasting temperature remains constant,the iron oxide crystals formed by increasing the amount of loading can enter the AC pore structure and accumulate to form more micropores.When the roasting temperature is raised from 400 to 500℃,the iron oxide is mainly transformed fromα-Fe_(2)O_(3)toγ-Fe_(2)O_(3),which improves the iron oxide dispersion and increases its denitration active site,allowing gas adsorption.When the Fe loading amount is 10%,and the roasting temperature is 500℃,the NO removal rate of the Fe/AC catalyst can reach 95%.According to the study,the low-temperature NH_(3)-SCR mechanism of Fe/AC catalyst is proposed,in which the redox reaction between Fe~(2+)and Fe~(3+)will facilitate the formation of reactive oxygen vacancies,which increases the amount of oxygen adsorption on the surface,especially the increase in surface acid sites,and promotes and adsorbs more reaction gases(NH_(3),O_(2),NO).The transformation from the standard SCR reaction to the fast SCR reaction is accelerated.杨征宇 黄帮福 ZHANG Guifang DAI Meng WEN Zhenjing LI Wanjun 2023Journal of Wuhan University of Technology(Materials Science)2023,38,3:0
13Graphene foam/hydrogel scaffolds for regeneration of peripheral nerve using ADSCs in a diabetic mouse model显示文摘The functional recovery of peripheral nerve injury(PNI)is unsatisfactory,whereas diabetes mellitus(DM)and its related complications further attenuate the restoration of diabetic PNI(DPNI).Adipose-derived stem cells(ADSCs)are promising candidates for treatment of DPNI due to their abundant source,excellent differentiation and paracrine ability.Our results showed that ADSCs remarkably enhanced the proliferation and migration of Schwann cells and endothelial cells,and tube formation.Mechanistically,ADSCs could regulate Nrf2/HO-1,NF-κB and PI3K/AKT/mTOR signaling pathways,showing multiple functions in reducing oxidative stress and inflammation,and regulating cell metabolism,growth,survival,proliferation,angiogenesis,differentiation of Schwann cell and myelin formation.In current study,novel graphene foam(GF)/hydrogel-based scaffold was developed to deliver ADSCs for treatment of DPNI.GF/hydrogel scaffold exhibited excellent mechanical strength,suitable porous network,superior electrical conductivity,and good biocompatibility.In vitro results revealed that GF/hydrogel scaffold could obviously accelerate proliferation of Schwann cells.Moreover,in vivo experiments demonstrated that ADSCs-loaded GF/hydrogel scaffold significantly promoted the recovery of DPNI and inhibited the atrophy of targeted muscles,thus providing a novel and attractive therapeutic approach for DPNI patients.Qun Huang Yuting Cai Xinrui Yang Weimin Li Hongji Pu Zhenjing Liu Hongwei Liu Mohsen Tamtaji Feng Xu Liyuan Sheng Tae-Hyung Kim Shiqing Zhao Dazhi Sun Jinbao Qin Zhengtang Luo Xinwu Lu 2022Nano Research2022,15,4:0
14Mechanical behavior and semiempirical force model of aerospace aluminum alloy milling using nano biological lubricant显示文摘Aerospace aluminum alloy is the most used structural material for rockets,aircraft,spacecraft,and space stations.The deterioration of surface integrity of dry machining and the insufficient heat transfer capacity of minimal quantity lubrication have become the bottleneck of lubrication and heat dissipation of aerospace aluminum alloy.However,the excellent thermal conductivity and tribological properties of nanofluids are expected to fill this gap.The traditional milling force models are mainly based on empirical models and finite element simulations,which are insufficient to guide industrial manufacturing.In this study,the milling force of the integral end milling cutter is deduced by force analysis of the milling cutter element and numerical simulation.The instantaneous milling force model of the integral end milling cutter is established under the condition of dry and nanofluid minimal quantity lubrication(NMQL)based on the dual mechanism of the shear effect on the rake face of the milling cutter and the plow cutting effect on the flank surface.A single factor experiment is designed to introduce NMQL and the milling feed factor into the instantaneous milling force coefficient.The average absolute errors in the prediction of milling forces for the NMQL are 13.3%,2.3%,and 7.6%in the x-,y-,and z-direction,respectively.Compared with the milling forces obtained by dry milling,those by NMQL decrease by 21.4%,17.7%,and 18.5%in the x-,y-,and z-direction,respectively.Zhenjing DUAN Changhe LI Yanbin ZHANG Min YANG Teng GAO Xin LIU Runze LI Zafar SAID Sujan DEBNATH Shubham SHARMA 2023Frontiers of Mechanical Engineering2023,18,1:0
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