Effect of Cooling Rate on Solidification and Segregation Characteristics of 904L Super Austenitic Stainless Steel

Yunong Li,Dening Zou,Wanwan Chen,Yingbo Zhang,Wei Zhang,Fanghong Xu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

To study and understand the solidification behavior of super austenitic stainless steel under different cooling rates and segregationlaws of alloying elements is of great significance to optimize the subsequent diffusion annealing homogenizationtreatment process and improve product quality. According to Thermo-Calc thermodynamic simulation results and combinedwith high temperature laser confocal scanning electron microscope (HT-CSLM), the tissue morphology of 904L superaustenitic stainless steel was observed in-situ during solidification. The solidification path of the test steel was determinedvia calculation with the Scheil-Gulliver model. Microscopy techniques, including true color microscopy, scanning electronmicroscopy (SEM), energy dispersive spectrometer (EDS), and electron probe microanalyzer (EPMA) were used to analyzethe influence of different cooling rates (6 ℃/min, 50 ℃/min, and 100 ℃/min) on the solidification structure and determine themain distribution law of alloying elements. This analysis determined that the solute distribution coefficient (K) of Cr, Mn,Mo, Cu, and Si elements is less than 1 during the solidification process, which means that they will accumulate in the liquidphase. Among them, elemental Mo segregation is the most severe, while elemental Ni hardly segregates. As the cooling rateincreases, the crystallization temperature of the test steel decreases, and the secondary dendrite arm spacing λ2 decreases,the concentration of Mo in the residual liquid phase increases.

Policy Heterogeneity and the Wealth Effect of Listed Companies in Chinese New-generation Information Industry

Li Yan,LI Yingbo 대한경영학회 2016 대한경영학회 학술발표대회 발표논문집 Vol.2016 No.1

Using daily data of 51 listed companies in Internet of things (IoT), cloud computing and big data area, this paper analyzes the wealth effects of different policy types in new-generation information industry. The results shows that: (1) In general, policies bring positive average abnormal return to listed companies in new-generation information industry weather in short or long run, that is, they produce a generally positive shareholder wealth effect;(2) The demand-pull policy is most effective in short time, while in long run, the supply-push policy is most effective ;(3) The wealth effect reacts differently to various policy instruments. In short time, the application demonstration policy and object program policy have the fiercest impact. In long run, technical support policy and financial support policy have the greatest effect;(4) Cross-sectional analysis shows, in short time, the more state-owned share-holding rate and lower ownership concentration, the greater the effect of policies. But in long run, the effect mechanism is more complex which has visible differences with that in short time.

Information Structure of Innovation Resoruce Allocation in China

Li Yingbo 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

We focus on issues concerning the designing method of information structure of innovation resource allocation. This paper outlines a theoretical framework of innovation resource allocation, including concept and patterns of innovation resource allocation. Then the paper provides the analysis of information structure and the effect on allocating innovation resource allocation. Furthermore, the paper discusses how to design information structure based on team model. The result of the model show that setting up favorite information structure with a center of sending out information is meaningful to heighten the efficiency of innovation resource allocation.

Phytochemical analysis of Panax species: a review

Yuangui Yang,Zhengcai Ju,Yingbo Yang,Yanhai Zhang,Li Yang,Zhengtao Wang 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.1

Panax species have gained numerous attentions because of their various biological effects on cardiovascular, kidney, reproductive diseases known for a long time. Recently, advanced analytical methods including thin layer chromatography, high-performance thin layer chromatography, gas chromatography, high-performance liquid chromatography, ultra-high performance liquid chromatography with tandem ultraviolet, diode array detector, evaporative light scattering detector, and mass detector, two-dimensional high-performance liquid chromatography, high speed counter-current chromatography, high speed centrifugal partition chromatography, micellar electrokinetic chromatography, high-performance anion-exchange chromatography, ambient ionization mass spectrometry, molecularly imprinted polymer, enzyme immunoassay, <SUP>1</SUP>H-NMR, and infrared spectroscopy have been used to identify and evaluate chemical constituents in Panax species. Moreover, Soxhlet extraction, heat reflux extraction, ultrasonic extraction, solid phase extraction, microwave-assisted extraction, pressurized liquid extraction, enzyme-assisted extraction, acceleration solvent extraction, matrix solid phase dispersion extraction, and pulsed electric field are discussed. In this review, a total of 219 articles published from 1980 to 2018 are investigated. Panax species including P. notoginseng, P. quinquefolius, sand P. ginseng in the raw and processed forms from different parts, geographical origins, and growing times are studied. Furthermore, the potential biomarkers are screened through the previous articles. It is expected that the review can provide a fundamental for further studies.

Biosynthesis of rare 20(R)-protopanaxadiol/protopanaxatriol type ginsenosides through Escherichia coli engineered with uridine diphosphate glycosyltransferase genes

Yu, Lu,Chen, Yuan,Shi, Jie,Wang, Rufeng,Yang, Yingbo,Yang, Li,Zhao, Shujuan,Wang, Zhengtao The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.1

Background: Ginsenosides are known as the principal pharmacological active constituents in Panax medicinal plants such as Asian ginseng, American ginseng, and Notoginseng. Some ginsenosides, especially the 20(R) isomers, are found in trace amounts in natural sources and are difficult to chemically synthesize. The present study provides an approach to produce such trace ginsenosides applying biotransformation through Escherichia coli modified with relevant genes. Methods: Seven uridine diphosphate glycosyltransferase (UGT) genes originating from Panax notoginseng, Medicago sativa, and Bacillus subtilis were synthesized or cloned and constructed into pETM6, an ePathBrick vector, which were then introduced into E. coli BL21star (DE3) separately. 20(R)-Protopanaxadiol (PPD), 20(R)-protopanaxatriol (PPT), and 20(R)-type ginsenosides were used as substrates for biotransformation with recombinant E. coli modified with those UGT genes. Results: E. coli engineered with $GT95^{syn}$ selectively transfers a glucose moiety to the C20 hydroxyl of 20(R)-PPD and 20(R)-PPT to produce 20(R)-CK and 20(R)-F1, respectively. GTK1- and GTC1-modified E. coli glycosylated the C3-OH of 20(R)-PPD to form 20(R)-Rh2. Moreover, E. coli containing $p2GT95^{syn}K1$, a recreated two-step glycosylation pathway via the ePathBrich, implemented the successive glycosylation at C20-OH and C3-OH of 20(R)-PPD and yielded 20(R)-F2 in the biotransformation broth. Conclusion: This study demonstrates that rare 20(R)-ginsenosides can be produced through E. coli engineered with UTG genes.

Roll-to-Roll Gravure Printed Electrochemical Sensors for Wearable and Medical Devices

Bariya, Mallika,Shahpar, Ziba,Park, Hyejin,Sun, Junfeng,Jung, Younsu,Gao, Wei,Nyein, Hnin Yin Yin,Liaw, Tiffany Sun,Tai, Li-Chia,Ngo, Quynh P.,Chao, Minghan,Zhao, Yingbo,Hettick, Mark,Cho, Gyoujin,Jav American Chemical Society 2018 ACS NANO Vol.12 No.7

<P>As recent developments in noninvasive biosensors spearhead the thrust toward personalized health and fitness monitoring, there is a need for high throughput, cost-effective fabrication of flexible sensing components. Toward this goal, we present roll-to-roll (R2R) gravure printed electrodes that are robust under a range of electrochemical sensing applications. We use inks and electrode morphologies designed for electrochemical and mechanical stability, achieving devices with uniform redox kinetics printed on 150 m flexible substrate rolls. We show that these electrodes can be functionalized into consistently high performing sensors for detecting ions, metabolites, heavy metals, and other small molecules in noninvasively accessed biofluids, including sensors for real-time, <I>in situ</I> perspiration monitoring during exercise. This development of robust and versatile R2R gravure printed electrodes represents a key translational step in enabling large-scale, low-cost fabrication of disposable wearable sensors for personalized health monitoring applications.</P> [FIG OMISSION]</BR>