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Effect of machining parameters on the milling process of 2.5D c/Sic ceramic matrix composites

MAcHINING ScIENcE AND TEcHNOLOGY 2020年第2期24卷 227-244页

作者： Zhang, Xuewei Yu, Tian Biao Li, Ming Wang, Zixuan Northeastern Univ Sch Mech Engn & Automat Shenyang Liaoning Peoples R China

The c/Sic ceramic matrix composites are widely used for high-value components in the nuclear, aerospace and aircraft industries. The cutting mechanism of machining c/Sic ceramic matrix composites is one of the most challenging problems in composites application. Therefore, the effects of machining parameters on the machinability of milling 2.5D c/Sic ceramic matrix composites is are investigated in this article. The related milling experiments has been carried out based on the c/Sic ceramic matrix composites fixed in two different machining directions. For two different machining directions, the influences of spindle speed, feed rate and depth of cut on cutting forces and surface roughness are studied, and the chip formation mechanism is discussed further. It can be seen from the experiment results that the measured cutting forces of the machining direction B are greater than those of the in machining direction A under the same machining conditions. The machining parameters, which include spindle speed, feed rate, depth of cut and machining direction, have an important influence on the cutting force and surface roughness. This research provides an important guidance for improving the machining efficiency, controlling and optimizing the machined surface quality of c/Sic ceramic matrix composites in the milling process.

关键词： chip formation mechanism c Sic composites cutting forces machining parameters milling surface roughness

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Biological Aging Modulates cell Migration via Lamin A/c-Dependent Nuclear Motion

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MIcROMAcHINES 2020年第9期11卷 801-801页

作者： Park, Jung-Won Han, Seong-Beom Hah, Jungwon Lee, Geonhui Kim, Jeong-Ki Kim, Soo Hyun Kim, Dong-Hwee Korea Univ KU KIST Grad Sch Converging Sci & Technol Seoul 02841 South Korea Korea Inst Sci & Technol Biomed Res Inst Ctr Biomat Seoul 02792 South Korea

Aging is a progressive functional decline in organs and tissues over time and typically represents the accumulation of psychological and social changes in a human being. Diverse diseases, such as cardiovascular, musculoskeletal, and neurodegenerative disorders, are now understood to be caused by aging. While biological assessment of aging mainly focuses on the gradual changes that occur either on the molecular scale, for example, alteration of gene expression and epigenetic modification, or on larger scales, for example, changes in muscle strength and cardiac function, the mechanics that regulates the behavior of individual cells and interactions between the internal elements of cells, are largely missing. In this study, we show that the dynamic features of migrating cells across different human ages could help to establish the underlying mechanism of biological age-dependent cellular functional decline. To determine the relationship between cellular dynamics and human age, we identify the characteristic relationship between cell migration and nuclear motion which is tightly regulated by nucleus-bound cytoskeletal organization. This analysis demonstrates that actomyosin contractility-dependent nuclear motion plays a key role in cell migration. We anticipate this study to provide noble biophysical insights on biological aging in order to precisely diagnose age-related chronic diseases.

关键词： aging cell motility lamin A c nuclear dynamics

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Novel thin-film reverse osmosis membrane with MXene Ti3c2Tx embedded in polyamide to enhance the water flux, anti-fouling and chlorine resistance for water desalination

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JOURNAL OF MEMBRANE ScIENcE 2020年 603卷

作者： Wang, Xiaoying Li, Qingqing Zhang, Jianfeng Huang, Haimeng Wu, Shaoyu Yang, Yan Hohai Univ Coll Mech & Mat Nanjing 211100 Peoples R China Nanjing Delnamem Technol Co Ltd Nanjing 210000 Peoples R China Hohai Univ Jiangsu Engn Res Ctr Utilizat Alternat Water Reso Nanjing 211100 Peoples R China

The development of high performance reverse osmosis (RO) membranes still remains a big challenge due to not only the trade-off between water flux and salt rejection, but also their easy fouling and chlorine attacking. In this paper, a novel thin-film nanocomposite RO membrane with two-dimensional MXene Ti 3 c 2 T x embedded in the polyamide (PA) layer was fabricated by in-situ interfacial polymerization with m-phenylenediamine aqueous solution and trimesoyl chloride. Due to the outstanding diffusion regulating effect of Ti 3 c 2 T x in accordance with the Fick's first law, the water permeability was elevated to a maximum value of 2.53 L m −2 h −1 bar −1 at a high Nacl salt rejection of 98.5%. Simultaneously, the enhanced anti-fouling, and chlorine resistance of the as-obtained PA-Ti 3 c 2 T x membrane were also obtained, outperforming the pristine PA and other related RO membranes in literature. Especially after a chlorine-resistance test at 10000 ppm h, a high salt rejection of 97.1% for the PA-Ti 3 c 2 T x membrane was still retained. Based on the microstructural observation and mechanism analysis, such an improvement in chlorine resistance was mainly ascribed to the interaction between surface functional groups of Ti 3 c 2 T x nanosheets with active chlorine, which effectively protected the PA matrix from being chlorine attacked. This work illustrates successfully a very new use of Ti 3 c 2 T x to improve the comprehensive performance for water desalination membranes for practical applications.

关键词： MXene Ti 3 c 2 T x Reverse osmosis (RO) membranes Water permeability Salt rejection Anti-fouling chlorine resistance

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In -situ generation of g -c 3 N 4 on BiVO 4 photoanode for highly e fficient photoelectrochemical water oxidation

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APPLIED SURFAcE ScIENcE 2020年 523卷

作者： Li, Siyuan Jiang, Yi Jiang, Wenchao Zhang, Yu Pan, Kai Wang, Song Hu, chongyang Zhang, Lu-Hua Xia, Lixin Liaoning Univ Coll Chem Shenyang 110036 Liaoning Peoples R China Shenzhen Univ Inst Microscale Optoelect Shenzhen 518060 Peoples R China Heilongjiang Univ Key Lab Funct Inorgan Mat Chem Minist Educ Harbin 150080 Heilongjiang Peoples R China Yingkou Inst Technol Yingkou 115000 Liaoning Peoples R China

constructing a heterojunction photoelectrode is an effective way to promote the photogenerated charge separation in photoelectrochemical (PEc) water oxidation. In this work, we successfully fabricated c 3 N 4 /BiVO 4 hybrid electrodes by integrating g-c 3 N 4 onto the nanoporous BiVO 4 via a simple in-situ synthesis method. The as-prepared c 3 N 4 /BiVO 4 photoanodes were systematically studied by Electrochemical Impedance Spectroscopy, steady-state surface photovoltage (SPV), transient SPV, Open circuit potential and Photoluminescence measurements. With an optimal loading of g-c 3 N 4 , the 2-c 3 N 4 /BiVO 4 electrode showed a high photocurrent density of 4.06 mA/cm 2 at 1.23 V (vs. RHE) for water oxidation, a 2.8 times enhancement over that of the BiVO 4 . It is found that g-c 3 N 4 improved the PEc performance of the photoanodes by simultaneously promoting the charge separation and surface reaction kinetics. When a NiOOH co-catalyst was immobilized onto the 2-c 3 N 4 /BiVO 4 electrode, both the PEc property and stability of the photoanode were enhanced. An extremely high photocurrent density of 5.44 mA/cm 2 at 1.23 V was achieved. The largest half-cell solar energy conversion efficiency for NiOOH/2-c 3 N 4 /BiVO 4 was 1.43% at 0.78 V, corresponding to 8.4 times that of unmodified BiVO 4 (0.17% at 0.97 V). This work brings new insight into the development of c 3 N 4 -based devices for application in solar to fuel conversion.

关键词： Photoelectrochemical Water Oxidation BiVO 4 c 3 N 4 Photoanode

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Synthesis and crystal Structure Studies of Mitomycin c Dihydrate

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crystal Structure Theory and Applications 2020年第2期9卷 13-21页

作者： Yingqi Feng Yongshou chen Yixin Ren Heng Zhang Shuang cao Key Laboratory for Green Chemical Process of Ministry of Education School of Chemical Engineering and Pharmacy Wuhan Institute of Technology Wuhan China

The absolute configuration of mitomycin c was determined?by X-ray single crystal diffraction?(cuKα), and a new?crystalline?dihydrate of mitomycin c had been prepared. The?experiment?result?provides?a definitive answer?to the real absolute configuration of mitomycin c and may put an end to the dispute?that baffles?researchers for decades.?At the same time, some contentious structures?about the mitomycin c in?American Pharmacopoeia?USP36-NF31,?chinese pharmacopoeia?2015?edtion?and numbers of?literatures are marked. The absolute configuration?is?also verified?by?1D (1H?and?13c) and 2D (HSQc, HMBc,?1H-1H?cOSY?and?NOESY) NMR studies?indirectly. Powder X-ray diffraction (PXRD) pattern of the?mitomycin c dihydrate?is similar to that calculated for?it, which?suggests that the purity?of?sample?is excellent.

关键词： crystal Structure Dihydrate Absolute configuration Mitomycin c

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A large close relative of c. elegans is slow-developing but not long-lived

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BMc EVOLUTIONARY BIOLOGY 2019年第1期19卷 1-14页

作者： Woodruff, Gavin c. Johnson, Erik Phillips, Patrick c. Univ Oregon Dept Biol Inst Ecol & Evolut Eugene OR 97403 USA

BackgroundVariation in body size is thought to be a major driver of a wide variety of ecological and evolutionary patterns, including changes in development, reproduction, and longevity. Additionally, drastic changes in natural context often have profound effects on multiple fitness-related traits. caenorhabditis inopinata is a recently-discovered fig-associated nematode that is unusually large relative to other members of the genus, including the closely related model system c. elegans. Here we test whether the dramatic increase in body size and shift in ecological context has led to correlated changes in key life history and developmental parameters within this *** four developmental milestones, c. inopinata was found to have a slower rate of development than c. elegans across a range of temperatures. Despite this, c. inopinata did not reveal any differences in adult lifespan from c. elegans after accounting for differences in developmental timing and reproductive mode. c. inopinata fecundity was generally lower than that of c. elegans, but fitness improved under continuous-mating, consistent with sperm-limitation under gonochoristic (male/female) reproduction. c. inopinata also revealed greater fecundity and viability at higher *** with observations in other ectotherms, slower growth in c. inopinata indicates a potential trade-off between body size and developmental timing, whereas its unchanged lifespan suggests that longevity is largely uncoupled from its increase in body size. Additionally, temperature-dependent patterns of fitness in c. inopinata are consistent with its geographic origins in subtropical Okinawa. Overall, these results underscore the extent to which changes in ecological context and body size can shape life history traits.

关键词： Body size Life history c elegans Lifespan Heterochrony

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coq to c Translation with Partial Evaluation 2021

Coq to C Translation with Partial Evaluation

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AcM SIGPLAN Workshop on Partial Evaluation and Program Manipulation (PEPM)

作者： Tanaka, Akira Natl Inst Adv Ind Sci & Technol Tsukuba Ibaraki Japan

ISBN: (纸本)9781450383059

coq proof assistant can be used to prove various properties of programs written in the Gallina language. It is also possible to translate Gallina programs to Ocaml programs. However, Ocaml is not suitable for low-level programs. Therefore, we are developing a coq plugin for Gallina to c translation. This plugin transforms functions written in Gallina into a form as close to c as possible within Gallina. This transformation includes partial evaluation, which improves execution efficiency and eliminates polymorphism and dependent types. We can easily verify in coq that this transformation does not change the execution result, and thus it is highly reliable. And Gallina functions after this transformation can be easily translated to c.

关键词： coq c Gallina translator compiler verification partial evaluation tail recursion

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Increase in medium-size rainfall events will enhance the c-sequestration capacity of biological soil crusts

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Research in cold and Arid Regions 2019年第1期11卷 81-92页

作者： cuiHua Huang Fei Peng Itaru Shibata Jun Luo Xian Xue Kinya Akashi Atsushi Tsunekawa Tao Wang Minqin Salinization Research Station Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and Resources Chinese Academy of Science International Platform for Dryland Research and Education Tottori University Arid Land Research Center Tottori University

Biological soil crusts(BScs) play important roles in the carbon(c) balance in arid regions. Net c balance of BScs is strongly dependent on rainfall and consequent activation of microbes in the BScs. The compensation-rainfall size for BScs(the minimum rainfall amount for a positive net c balance) is assumed to be different with BScs of different developmental stages. A field experiment with simulated rainfall amount(SRA) of 0, 1, 5, 10, 20, and 40 mm was conducted to examine the c fluxes and compensation-rainfall size of BScs in different parts of fixed dunes in the ecotone between the Badain Jaran Desert and the Minqin Oasis. We found algae-lichen crust on the interdunes and crest, algae crust on the leeward side, and lichen-moss crust on the windward. Even a small rainfall(1 mm) can activate both photosynthesis and respiration of all types of BScs. The gross ecosystem production, ecosystem respiration, and net ecosystem exchange were significantly affected by SRA, hours after the simulated rainfall, position on a dune, and their interactions. The rapid activation of photosynthesis provides a c source and therefore could be responsible for the increase of c efflux after each rewetting. c-uptake and-emission capacity of all the BScs positively correlated with rainfall size, with the lowest c fluxes on the leeward side. The compensation rainfall for a net c uptake was 3.80, 15.54, 8.62, and 1.88 mm for BScs on the interdunes, the leeward side, the crest, and the windward side, respectively. The whole dune started to show a net c uptake with an SRA of 5 mm and maximized with an SRA of about 30 mm. The compensation-rainfall size is negatively correlated with chlorophyll content. Our results suggest that BScs will be favored in terms of c balance, and sand dune stabilization could be sustained with an increasing frequency of 5-10 mm rainfall events in the desert-oasis transitional zone.-

关键词： biological soil crust rainfall size desert-oasis ecotone c balance arid region

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Vapor Recompression c 3 Splitter: Design and control

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IFAc-PapersOnLine 2020年第1期53卷 117-122页

作者： Aditya Anand Vivek Kumar Nitin Kaistha Chemical Engineering Indian Institute of Technology Kanpur Kanpur India 208016

Vapor recompression (VRc) based heat integration is usually employed for purifying a propylene-propane mixture in a c 3 splitter. A fixed speed drive or a variable speed drive compressor may be employed for overhead vapor recompression. In this work, economic controllable designs for the two compressor types in a VRc c 3 splitter are obtained via rigorous steady state and pressure driven closed loop dynamic simulations. A simple dual ended decentralized composition control system is shown to provide effective column regulation. The economic controllable design results indicate that when a fixed speed drive compressor is used, significant pressure drop must be provided across the compressor suction throttling valve for sufficient rangeability towards worst-case disturbance rejection. Accordingly, the column pressure and necessary compression ratio are higher for an overall more expensive process compared to a variable speed drive compressor. The case study highlights the importance for considering control at the conceptual design stage for designing a robust operable process.

关键词： c 3 splitter process design controllability process control

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Phase 1 Study of OPT-302 Inhibition of Vascular Endothelial Growth Factors c and D for Neovascular Age-Related Macular Degeneration

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OPHTHALMOLOGY RETINA 2020年第3期4卷 250-263页

作者： Dugel, Pravin U. Boyer, David S. Antoszyk, Andrew N. Steinle, Nathan c. Varenhorst, Michael P. Pearlman, Joel A. Gillies, Mark c. Finger, Robert P. Baldwin, Megan E. Leitch, Ian M. Retinal Consultants Arizona Phoenix AZ USA Retina Vitreous Associates Med Grp Beverly Hills CA USA Charlotte Eye Ear Nose & Throat Associates Charlotte NC USA Calif Retina Consultants Santa Barbara CA USA Vitreo Retinal Consultants & Surg Wichita KS USA Retinal Consultants Med Grp Sacramento CA USA Univ Sydney Save Sight Inst Sydney NSW Australia Univ Bonn Dept Ophthalmol Bonn Germany Opthea Ltd Level 4650 Chapel St South Yarra Vic 3195 Australia

Purpose: OPT-302 is a novel inhibitor of vascular endothelial growth factor (VEGF)-c and VEGF-D. A phase 1 trial assessed the safety of intravitreal OPT-302 as monotherapy or combined with ranibizumab (Lucentis;Genentech, South San Francisco, cA) in patients with neovascular age-related macular degeneration (nAMD). Design: Open-label, dose escalation followed by a randomized dose expansion. Participants: Fifty-one patients with nAMD who were either treatment naive (n = 25) or previously were treated with anti-VEGF A therapy (n = 26). Methods: In the dose escalation, groups of 5 patients in 4 cohorts received ascending doses of OPT-302 (0.3 mg, 1 mg, or 2 mg) in combination with ranibizumab (0.5 mg), or as monotherapy (2 mg). In the dose expansion, 31 patients were randomized (3:1) to OPT-302 (2 mg) in combination with ranibizumab (n = 23) or as monotherapy (n = 8). Participants received three intravitreal treatments of OPT-302 once every 4 weeks either with or without ranibizumab. Main Outcome Measures: Safety and tolerability, OPT-302 pharmacokinetics and immunogenicity, effects on best-corrected visual acuity (BcVA), and anatomic changes. Results: Intravitreal OPT-302 with or without ranibizumab was well tolerated with low systemic exposure, no dose-limiting toxicities and no immunogenicity. In patients receiving OPT-302 monotherapy, 7 of 13 (54%) did not require rescue anti-VEGF-A therapy and the mean change in BcVA from baseline to week 12 was +5.6 letters (range, 0-18 letters). Mean BcVA gains from baseline to week 12 following combination OPT-302 with ranibizumab were +10.8 letters (95% confidence interval [cI], 4-17;n = 18) in treatment-naive patients and +4.9 letters (95% cI, 3-7;n = 19) in previously treated patients, respectively. corresponding reductions in mean central subfield thickness at week 12 in both groups were -119 mu m (95% cI, -176 to -62 mu m) and -54 mu m (95% cI, -82 to -26 mu m), respectively, whilst 50% of treatment-naive patients also sho

关键词： AE adverse event AMD age-related macular degeneration BcVA best-corrected visual acuity cI confidence interval c max maximum concentration cNV choroidal neovascularization cST central subfield thickness DLT dose-limiting toxicity ETDRS Early Treatment Diabetic Retinopathy Study FA fluorescein angiography IOP intraocular pressure nAMD neovascular age-related macular degeneration PIGF placental growth factor SAE serious adverse event SD spectral-domain SRF subretinal fluid VEGF vascular endothelial growth factor VEGFR vascular endothelial growth factor receptor

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