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Gut microbiota and transcriptome response of earthworms(Metaphire guillelmi)to polymyxin B exposure

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Journal of Environmental Sciences 2023年第11期133卷 37-47页

作者： Jun Zhao Guilan Duan Yongguan zhu dong zhu State Key Lab of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

Polymyxin B(PMB)has received widespread attention for its use as a last-line therapy against multidrug-resistant bacterial ***,the consequences of unintended PMB exposure on organisms in the surrounding environment remain ***,this study investigated the effects of soil PMB residue on the gut microbiota and transcriptome of earthworms(Metaphire guillelmi).The results indicated that the tested doses of PMB(0.01–100 mg/kg soil)did not significantly affect the richness and Shannon’s diversity index of the earthworm gut microbiota,but PMB altered its community structure and taxonomic ***,PMB significantly affected Lysobacter,Aeromonas,and Sphingomonas in the soil microbiota,whereas Pseudomonas was significantly impacted the earthworm gut ***,active bacteria responded more significantly to PMB than the total microbial *** genera such as Acinetobacter and Bacillus were highly correlated with differential expression of some genes,including up-regulated genes associated with folate biosynthesis,sulphur metabolism,and the IL-17 signalling pathway,and downregulated genes involved in vitamin digestion and absorption,salivary secretion,other types of O-glycan biosynthesis,and the NOD-like receptor signalling *** results suggest that adaptation to PMB stress by earthworms involves changes in energy metabolism,their immune and digestive systems,as well as glycan *** study findings help elucidate the relationship between earthworms and their microbiota,while providing a reference for understanding the environmental risks of PMB.

关键词： Microbiome Antibiotic Soil fauna Active microbiota Transcriptome

Trajectory control strategy of cathodes in blisk electrochemical machining

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Chinese Journal of Aeronautics 2013年第4期26卷 1064-1070页

作者： zhu dong zhu Di Xu Zhengyang Zhou Laishui College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

A turbine blisk, which combines blades and a disk together, is one of the most important components of an aero engine. In the process of blisk electrochemical machining （ECM）, the sheet cathode, which is usually used as a tool electrode, has a complicated structure. In addition to that, the channel between the adjacent blades is narrow and twisted, so interference is apt to happen when the sheet cathode feeds into the channel. Therefore, it is important to choose suitable trajectory control strategy. In this paper, a new trajectory control strategy of the sheet cathode is presented and corresponding simulation analysis is conducted on the basis of an actual blisk model. The simulation results demonstrate that the sheet cathode can feed into the channel by a spatial line trajectory without interference. Moreover, the verification experiments are carried out according to the simulation. The experimental results show that the cathode can move into the channel without interference. It is verified that the new trajectory control strategy is correct and can be used in the blisk ECM process successfully.

关键词： Blisk Cathodes Electrochemical machining Feed Trajectory control

Optimization of flow field in electrochemical trepanning of integral cascades(Ti6Al4V)

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Chinese Journal of Aeronautics 2022年第10期35卷 354-364页

作者： Gaopan LEI dong zhu Jiabao LI College of Mechanical&Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Ti6Al4V is widely applied in the integral cascades of aero *** an effective machining method,electrochemical trepanning(ECTr)has unique advantages in processing surface parts made of hard-to-cut *** ECTr,the state of the flow field has a significant effect on processing stability and machining *** improve the uniformity of the flow field when ECTr is applied to Ti6Al4V,two different flow modes are designed,namely full-profile electrolyte supply(FPES)and edges electrolyte supply(EES).Different from the traditional forward flow mode,the flow directions of the electrolyte in the proposed modes are controlled by inlet *** show that the flow field under EES is more uniform than that under *** further enhance the uniformity of the flow field,the structure of EES is optimized by modifying the insulating *** the optimized configuration,the longitudinal distance between the center of the inlet hole and the center of the blade is 6.0 mm,the lateral distance between the centers of the inlet holes on both sides is 16.5 mm,the length to which the electrolyte enters the machining area is 1.5 mm,and the height of the insulating sleeve is 13.5 mm.A series of ECTr experiments are performed under the two flow *** with EES,the blade machined by FPES is less accurate and has poorer surface quality,with a surface roughness(R_(a))of 3.346μ*** the optimized EES,the machining quality is effectively enhanced,with the surface quality improved from R_(a)=2.621μm to R_(a)=1.815μm,thus confirming the efficacy of the proposed methods.

关键词： Edges electrolyte supply Electrochemical trepanning Flow field Structure optimization Surface quality

Electrochemical trepanning with an auxiliary electrode

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Chinese Journal of Aeronautics 2021年第5期34卷 183-194页

作者： Ting JIANG dong zhu Gaopan LEI National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Electrochemical trepanning(ET)is one of the main methods for processing the blisks in ***,stray corrosion in ET has a very negative impact on the machining quality of the *** paper proposes an innovative ET method with an auxiliary electrode surrounding the inner wall of the cavity above the ***-dimensional electric-field models are established and simulations are carried out with the auxiliary electrode at different positions and different electric *** electric-field simulations show that adding the auxiliary electrode reverses the directions of the current lines in the processed area,thereby protecting *** results show that when the distance from the bottom of the auxiliary electrode to the top of the cathode tool is 3 mm and the potential difference between the auxiliary electrode and the anode workpiece is 5 V,the area corroded by stray current is *** are performed under the parameter values determined by the simulations,and they confirm that this method is effective at reducing stray ***,at a feed rate of 2.5 mm/min,the blade taper angle is decreased from 1.37°to-0.09°,the thickness of the leading and trailing edges is increased from 0.307 mm to 0.704 mm,and the average surface roughness is decreased from S_(a)=8.239μm to S_(a)=7.028μm.

关键词： Aero-engine Auxiliary electrode Current density Electrochemical trepanning Stray corrosion

Experimental research on electrochemical machining of titanium alloy Ti60 for a blisk

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Chinese Journal of Aeronautics 2016年第1期29卷 274-282页

作者： Chen Xuezhen Xu Zhengyang zhu dong Fang Zhongdong zhu Di College of Mechanical and Electrical Engineering Nanjing University of Aeronautics & Astronautics

Ti60 （Ti-5.6A1-4.8Sn2Zr-1Mo-0.35Si-0.7Nd） is a high-temperature titanium alloy that is now used for important components of aircraft engines. Electrochemical machining （ECM） is a promising technique that has several advantages, such as a high machining rate, and can be used on a wide range of difficult-to-process materials. In this paper, orthogonal experiments are conducted to investigate ECM of Ti60, with the aim of determining the influences of some electrochemical pro- cess parameters on the surface roughness. The most important parameter is found to be the frequency of the pulsed power supply. It is found that using suitably optimized parameters for ECM can greatly decrease the surface roughness ofa workpiece. A surface roughness of approximately 0.912 μm can be obtained with the following optimal parameters： NaC1 electrolyte concentration 13wt%, voltage 20 V, pulse frequency 0.4 kHz, duty cycle 0.3, temperature 23 ℃, and anode feed rate 0.5 mm/min. Furthermore, blisk blades have been successfully processed using these optimized parameters

关键词： Blisk Electrochemical machining(ECM) Surface roughness Titanium alloy Ti60

Observation of etch pits in Fe-36wt%Ni Invar alloy

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International Journal of Minerals,Metallurgy and Materials 2014年第7期21卷 682-686页

作者： dong-zhu Lu Min-jie Wu Division of Surface Engineering of Materials Institute of Metal ResearchChinese Academy of Sciences

To indirectly investigate the dislocation behavior of Fe-36wt%Ni Invar alloy by the etch pit method, polished Invar specimens were etched by a solution containing 4 g copper sulfate, 20 mL hydrochloric acid, and 20 mL deionized water for 2 min. Etch pits in the etched surfaces were observed. All the etch pits in one specific grain exhibited similar shapes, which are closely related to the grain orienta-tions. These etch pits were characterized as dislocation etch pits. It was observed that etch pits arranged along grain boundaries, gathered at grain tips and strip-like etch pit clusters passed through a number of grains in the pure Invar specimens. After the addition of a small amount of alloying elements, the identification of a single dislocation etch pit is challenging compared with the pure Invar alloy. Thus, the observation of etch pits facilitates the investigation on the dislocation behavior of the pure Invar alloy. In addition, alloying elements may affect the densities and sizes of etch pits.

关键词： Invar alloy dislocations etch pit technique alloying elements

Role of chemotherapy in stage Ⅱb nasopharyngeal carcinoma

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Chinese Journal of Cancer 2012年第12期31卷 573-578页

作者： Xin-Bin Pan Xiao-dong zhu Department of Radiation Oncology Cancer Hospital of Guangxi Medical University

The efficacy of neoadjuvant chemotherapy and adjuvant chemotherapy on stage Ⅱb nasopharyngeal carcinoma (NPC) remains unclear. Conventional two-dimensional radiotherapy combined with concurrent chemotherapy can improve the overall survival, progression-free survival, recurrence-free survival, and distant metastasis-free survival of patients with stage Ⅱb NPC. Intensity-modulated radiotherapy without concurrent chemotherapy also provides good outcomes for patients with stage Ⅱb NPC. This article summarizes the features of stage Ⅱb NPC and reviews the role of chemotherapy in this subgroup of NPC.

关键词： lib 鼻咽癌化疗全国人民代表大会一阶生存期放射治疗 NPC

Effects of water deficit and high N fertilization on wheat storage protein synthesis,gluten secondary structure,and breadmaking quality

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The Crop Journal 2022年第1期10卷 216-223页

作者： Junxian Liu Junwei Zhang Gengrui zhu dong zhu Yueming Yan Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement College of Life ScienceCapital Normal UniversityBeijing 100048China

The content and composition of wheat storage proteins are the major determinants of dough rheological properties and breadmaking quality and are influenced by cultivation *** study aimed to investigate the effects of water deficit and high N-fertilizer application on wheat storage protein synthesis,gluten secondary structure,and breadmaking ***-phase ultrahigh-performance liquid chromatography analysis showed that storage protein and gluten macropolymer accumulation was promoted under both independent applications and a combination of water-deficit and high N-fertilizer ***-transform infrared spectroscopy showed that water deficit and high N-fertilizer treatments generally improved protein secondary structure formation and lipid accumulation,and reduced flour *** particular,high N-fertilizer application increasedβ-sheet content by 10.4%and the combination of water-deficit and high N-fertilizer treatments increased random coil content by 7.6%.These changes in gluten content and secondary structure led to improved dough rheological properties and breadmaking quality,including superior loaf internal structure,volume,and *** results demonstrate that moderately high N-fertilizer application under drought conditions can improve gluten accumulation,gluten secondary structure formation,and baking quality.

关键词： Water deficit High N-fertilizer Storage proteins Gluten structure Breadmaking quality

Cathode design investigation based on iterative correction of predicted profile errors in electrochemical machining of compressor blades

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Chinese Journal of Aeronautics 2016年第4期29卷 1111-1118页

作者： zhu dong Liu Cheng Xu Zhengyang Liu Jia College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

Electrochemical machining (ECM) is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and is a core problem influencing machining accuracy, especially for complex profiles such as compressor blades in aero engines. A new cathode design method based on iterative correction of predicted profile errors in blade ECM is proposed in this paper. A mathematical model is first built according to the ECM shaping law, and a simulation is then carried out using ANSYS software. A dynamic forming process is obtained and machining gap distributions at different stages are analyzed. Additionally, the simulation deviation between the prediction profile and model is improved by the new method through correcting the initial cathode profile. Furthermore, validation experiments are conducted using cathodes designed before and after the simulation correction. Machining accuracy for the optimal cathode is improved markedly compared with that for the initial cathode. The experimental results illustrate the suitability of the new method and that it can also be applied to other complex engine components such as diffusers. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.

关键词： Cathode design Compressor blade Correction Electric field Electrochemical machining