Favorable Impact Toughness of High Heat Input Coarse-Grained HAZ in an Ultra-Low Carbon High-Strength Microalloyed Steel

Fuhui Cui,Junjie Wang1,Xiangdong Gan,Dawei Yu,Ilya Vladimirovich Okulov,Qinghua Tian,Xueyi Guo 대한금속ᆞ재료학회 2023 METALS AND MATERIALS International Vol.29 No.2

Liquid Mg is capable of quickly eroding the refractory Ni-based superalloy and selectively dissolve Ni, which opens up anew avenue for the recycling of superalloy scraps for comprehensive metal reclamation. This study aims at investigating theunderlining mechanism and kinetics of the selective dissolution of Ni from Inconel 718 (one type of Ni-based superalloy)with liquid Mg, by experimenting at 750, 800, and 850 °C for various amounts of time in an inert atmosphere. This selectivedissolution process is also known as liquid metal dealloying. Results show that a permeable dealloyed layer was formedresulting from the preferential dissolution of Ni over other metallic elements (e.g., Fe, Cr, Nb, Mo, and Ti). At the dealloyingforefront, the grain boundaries of the matrix γ phase were preferentially eroded by liquid Mg. The opposite concentrationgradients of Ni (4–9 wt%) and Mg (12–18 wt%) cross the dealloyed layer suggested their counter diffusion. A higher heatingtemperature substantially increased the dealloying rate.

A simple electrospinning strategy to achieve the uniform distribution of ultra‑fine CoP nanocrystals on carbon nanofibers for efficient lithium storage

Qinghua Wang,Wei Wang,Junlin Huang,Hong Yin,Yucan Zhu,Haitao Wang,Minjie Zhou,Binhong He,Zhaohui Hou,Wenyuan Xu 한국탄소학회 2023 Carbon Letters Vol.33 No.1

Transition-metal phosphides (TMPs), a promising anode material for lithium-ion batteries (LIBs), are limited in application because of its serious volume effect in the cycle. In this work, a simple electrospinning strategy was proposed to restrict the grain size of CoP nanocrystals by nano-confined effect of carbon nanofibers with ligands. The addition of ligands not only could realize the uniform dispersion of CoP nanocrystals, but also strengthen the bond between the metals and carbon nanofibers. As a result, the CoP/CNF composite exhibits excellent lithium storage performance, and its reversible specific capacity could reach 1016.4 mAh g? 1 after 200 cycles at a current density of 200 mA g? 1. The research is anticipated to provide a new idea for the preparation of anode materials for lithium ion batteries.

Experimental Study of Horizontal Gas-liquid Two-phase Flow in Two Medium-diameter Pipes and Prediction of Pressure Drop through BP Neural Networks

Wang Qinghua,Zou Honglan,Luo Wei,Yang Junzheng,Wen Xiaohong,Wang Yan 한국유체기계학회 2018 International journal of fluid machinery and syste Vol.11 No.3

Horizontal gas-liquid two-phase flow is of crucial importance in oil-gas storage and transportation. In view of previous researches with the lack of horizontal gas-liquid two-phase flow in medium-diameter pipes (60-75 ㎜), experiments were conducted in DN 60 and DN75 at medium-high liquid velocity (50-250 m3/d) and high gas-liquid ratio (20-500 m3/m3). Comparison between flow patterns maps in DN60 and DN75 and the Taitel-Dukler model showed that only flow patterns map in DN60 agreed well. On the basis of experimental data analysis, variation laws of liquid holdup and pressure drop were determined. Besides, this paper developed a method to predict liquid holdup and pressure drop through BP neural networks. Results proved the capability of BP neural networks. The further validation can be made in practical applications.

哈尼族的梯田与服饰

王清华(Wang Qinghua) 아시아민족조형학회 2001 아시아민족조형학회 국제학술회의 Vol.2001 No.-

Hani people is an ancient minority which has centuries-old history and abundant culture, living in the southwest china Its population is more than 130m, moot of which live in the between Yuan River, that is Red River, and LanChang River in the southern Yunnan. That covers the AiLao Mountains and WuLiang Mountains. These two mountains stretch out from the Wei Mountain of the western Yunnan, separate at YunLing Mountains, traverse the southern Yunnan. The Hani people"s habitat ranges from latitude 21 degrees north to 26 degrees, from longitude 99 degrees east to 104 degrees. There are other minorities in this area, such as Yi, Bai Dai LaHu, Miao, Yao, Hui, Zhuang and so on. The sea level of Hani people"s habitat is from 800 meters to 2,500 meters. Taking the advantages of natural conditions to rec1aim terrace is the flair and tradition of Hani people. All habitats of Hani people have terrace reclaimed by them in the tableland of southwestern Ghina. In other words, terrace has been the emblem of Hani people. As the entity of culture and the creative and labor fruits, terrace cohered the ancient history of Hani people, included rich and colorful culture, hold, together with various life styles of Hani people. Costume is indispensable in civilized living. It"s the emblem and carrier of culture. The costume of Hani people has a tight relation with the terrace. In the view of material culture, the costume is come from terrace, and in the view of spiritual culture, the design and taste are also come from terrace. Therefore, we can say that terrace is the source of Hani people"s costume which is a kind of material and spiritual culture. And Hani people"s costume reflected the terrace, an gigantic material and spiritual entity, an impressive artwork of earth.

An Approach for Reducing Cutting Energy Consumption with Ultra-High Speed Machining of Super Alloy Inconel 718

Bing Wang,Zhan-qiang Liu,Qinghua Song,Yi Wang,iaoping Ren 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1

High energy efficient machining is beneficial for sustainable manufacture which is an important target pursued by workshops. The paper aims to prove the feasibility for reducing cutting energy consumption with ultra-high speed machining (UHSM) of super alloy Inconel 718. Firstly, orthogonal cutting experiments of Inconel 718 are performed with a wide cutting speed range. Through analyses of chip micrographs, it is found that plastic deformation accompanied with ductile fracture contributes to serrated chip formation, while fragmented chips are produced through brittle fracture. The results demonstrate that brittle regime machining can be realized for Inconel 718 with ultra-high cutting speeds. Secondly, considering varied deformation behavior for chips with different morphologies, specific cutting energy models for HSM under varied cutting parameters are developed and verified. Then the influences of cutting speed and uncut chip thickness on cutting energy consumption during HSM are revealed. The research results demonstrate the practicability for reducing cutting energy consumption with brittle regime machining of Inconel 718. At last, the relationship between AE signals and cutting energy consumption is explored, and it proves that AE signals are applicable in monitoring cutting energy consumption. The research can provide guidance for energy saving through optimizing cutting parameters.

Characterization and mechanism analysis of penicillin G biodegradation with Klebsiella pneumoniae Z1 isolated from waste penicillin bacterial residue

Pu Wang,Huiling Liu,Huan Fu,Xiuwen Cheng,Bing Wang,Qinghua Cheng,Jian Zhang,Pan Zou 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.27 No.-

In this study, a strain Z-1 has been isolated from penicillin bacterial residue. The physicochemicalproperties and molecular phylogenetic analysis of the strain were characterized by atomic forcemicroscope (AFM) and scanning electron microscope (SEM) and 16SrDNA, indicating the strain belongsto genus Klebsiella pneumoniae. Furthermore, the biodegradation process of PENG was investigated with99.99% degradation efficiency. Afterwards, high performance liquid chromatography (HPLC) and LC-MS/MS analysis were performed to identify its degradation products. Moreover, the possible mechanism wasproposed and confirmed in detail. These results suggest Klebsiella pneumoniae Z1 become a promisingalternative for improving penicillin removal from environment

Analysis of Glycolysis Products of Polyurethane Fiber Waste with Diethylene Glycol

Wang, Jingrong,Chen, Dajun,Zhang, Qinghua The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.1

Diethylene glycol and dibutyl tin dilaurate were used to degrade polyurethane fiber waste in this paper. The glycolysis products were separated into two phases including white solid and brown liquid by a freezing process. The chemical structure and thermal property of the purified solid product were characterized by Fourier transform infrared(FTIR) spectrometer, $^1H$ nuclear magnetic resonance($^1H$ NMR) and differential scanning calorimetry(DSC). The solid product was mainly polytetrahydrofuran. The analysis of the liquid product was carried out by FTIR and high performance liquid chromatography-electrospray ionization-mass spectrometry(HPLC-ESI-MS). The liquid phase included various components such as aromatic amine, diethylene glycol-propylene diamine compound and so on. The glycolysis mechanism of polyurethane fiber waste is also discussed in this paper.

Lactobacillus delbrueckii ssp. lactis R4 Prevents Salmonella typhimurium SL1344-Induced Damage to Tight Junctions and Adherens Junctions

Qinghua Yu,Liqi Zhu,Zhisheng Wang,Pengcheng Li,Qian Yang 한국미생물학회 2012 The journal of microbiology Vol.50 No.4

Cell junctions are the gatekeepers of the paracellular route and defend the mucosal barrier. Several enteropathogenic bacteria can invade intestinal epithelial cells by targeting and damaging cell junctions. It is not well understood how Salmonella typhimurium is able to overcome the intestinal barrier and gain access to the circulation, nor is it understood how Lactobacillus prevents the invasion of S. typhimurium. Therefore, we sought to determine whether infection with S. typhimurium SL1344 could regulate the molecular composition of cell junctions and whether Lactobacillus delbrueckii ssp. lactis R4 could affect this modification. Our data demonstrated that infection of Caco-2 cells with S. typhimurium over 2 h resulted in a redistribution of claudin-1, ZO-1, occluding,and E-cadherin. Western blot analysis of epithelial cell lysates demonstrated that S. typhimurium could decrease the expression of cell junction proteins. However, L. delbrueckii ssp. lactis R4 ameliorated this destruction and induced increased expression of ZO-1, occludin, and E-cadherin relative to the levels in the control group. The results of these experiments implied that S. typhimurium may facilitate its uptake and distribution within the host by regulating the molecular composition of cell junctions. Furthermore,Lactobacillus may prevent the adhesion and invasion of pathogenic bacteria by maintaining cell junctions and the mucosal barrier.

Progressive Collapse Analysis of Large-span Reticulated Domes

Qinghua Han,Mingjie Liu,Yan Lu,Chenxu Wang 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2

The paper presents the progressive collapse analysis of large-span reticulated domes based on Alternate path (AP) method. Nonlinear buckling analysis is conducted on a large span roof with two different structural layouts. The results show that although large-span single-layer reticulated dome has a certain redundancy. When 10 key elements or 3 key nodes were removed, the single-layer reticulated dome under the service load would cause progressive collapse. Therefore the protection of key nodes of this structure should be strengthened. However, the redundancy of large-span double-layer reticulated dome is 7 to 13 times that of single-layer reticulated dome. When 10 key elements or 3 key nodes were removed, the double-layer reticulated dome under the service load would not cause progressive collapse. Hence, the resistance to progressive collapse of large-span double-layer reticulated dome is better than that of large-span single-layer reticulated dome.

Optimized M9 Minimal Salts Medium for Enhanced Growth Rate and Glycogen Accumulation of Escherichia coli DH5α

Wang, Liang,Liu, Qinghua,Du, Yangguang,Tang, Daoquan,Wise, Michael J. The Korean Society for Microbiology and Biotechnol 2018 한국미생물·생명공학회지 Vol.46 No.3

Glycogen plays important roles in bacteria. Its structure and storage capability have received more attention recently because of the potential correlations with environmental durability and pathogenicity. However, the low level of intracellular glycogen makes extraction and structure characterization difficult, inhibiting functional studies. Bacteria grown in regular media such as lysogeny broth and tryptic soy broth do no accumulate large amounts of glycogen. Comparative analyses of bacterial media reported in literature for glycogen-related studies revealed that there was no consistency in the recipes reported. Escherichia coli $DH5{\alpha}$ is a convenient model organism for gene manipulation studies with respect to glycogen. Additionally, M9 minimal salts medium is widely used to improve glycogen accumulation, although its composition varies. In this study, we optimized the M9 medium by adjusting the concentrations of itrogen source, tryptone, carbon source, and glucose, in order to achieve a balance between the growth rate and glycogen accumulation. Our result showed that $1{\times}M9$ minimal salts medium containing 0.4% tryptone and 0.8% glucose was a well-balanced nutrient source for enhancing the growth and glycogen storage in bacteria. This result will help future investigations related to bacterial physiology in terms of glycogen function.