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Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.t.Jeong S.w.Lee w.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

the superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 K.the microstructural refinement of this alloy was achieved by employing high-ratio differential speed rolling.the best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were obtained.During the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 K.therefore,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and mechanisms.In the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation mechanism.It was concluded that solute drag creep is unlikely to occur.During the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain hardening.Deformation mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation grain size grain growth

SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation

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Earth and Planetary Physics 2024年第1期8卷 25-38页

作者： S.Parsons D.J.Hall O.Hetherington t.w.Buggey t.Arnold M.w.J.Hubbard A.Holland Centre for Electronic Imaging the Open UniversityMilton KeynesMK76AAUK

throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.three CCDs have been characterised,the two flight devices and the flight spa re.this has been carried out at the Open University in a bespo ke cleanroom measure ment facility.the results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.the se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCD soft X-ray imager characterisation SMILE

Excess dietary Lys reduces feed intake, stimulates jejunal CCK secretion and alters essential and non‑essential blood AA profile in pigs

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1336-1346页

作者： Maximiliano Muller Elout van Liefferinge Alan tilbrook Robert van Barneveld Eugeni Roura Centre for Nutrition and Food Sciences Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandBrisbaneQueensland 4072Australia Laboratory of Animal Nutrition and Animal Product Quality(LANUPRO) Department of Animal Sciences and Aquatic EcologyGhent University339000 GhentFlandersBelgium Centre for Animal Science Queensland Alliance for Agriculture and Food Innovation and the School of Veterinary ScienceThe University of QueenslandBrisbaneQueensland 4072Australia SunPork group BrisbaneQueensland 4009Australia

Background Commercial diets are frequently formulated to meet or exceed nutrient levels including those of lim-iting essential amino acids(AA)covering potential individual variations within the herd.However,the provision of dietary excess of AA,such as Lys,may lead to reduced appetite and growth in pigs.the mechanisms modulat-ing these responses have not been extensively investigated.this study evaluated the effect of Lys dietary excesses on performance and satiety biomarkers in post weaning pigs.Methods twenty-four pigs aged 21 d and weighing 6.81±0.12kg(mean±SEM)were individually housed and offered 1 of 4 dietary treatments for 3weeks:a diet containing a standardized ileal digestible Lys reaching 100%(t0),120%(t1),150%(t2)or 200%(t3)of the NRC(2012)requirements.At the end of the experiment,blood samples from the cephalic vein of the t0 and t3 groups were obtained for AA analysis.In addition,primary intestinal cultures from t0 pigs were used,following their humane killing,to evaluate the effect of Lys on gut hormone secretion and AA sensors gene expression under ex vivo conditions.Results Feed intake was linearly reduced(Pthe weight gain to feed ratio reduced(Pwith increased dietary levels of Lys during the third-and first-week post weaning,respectively.Cholecystokinin con-centration(Pthe metabotropic glutamate receptor 1 and the solute carrier family 7 member 2(Pgene expression was enhanced in proximal jejunum tissues incubated with Lys at 20mmol/L when compared to the control(Lys 0mmol/L).Plasma Lys and glu(Ptration increased in the t3 compared to t0 pigs.In contrast,plasma levels of His,Val,thr,Leu(Pgln(Pwere lower in t3 than t0 pigs.Conclusion the present results confirm that excess dietary Lys inhibits hunger in pigs.Moreover,the results provide evidence of pre-and post-absorptive mechanisms modulating these responses.Lys dietary excesses should be nar-rowed,when possible,to avoid negative effects of the AA on appetite in pigs.

关键词： Amino acid Blood Cholecystokinin Feed intake Lysine Pig Satiety

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the CCD instrument background of the SMILE SXI

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Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.w.J.Hubbard O.Hetherington D.J.Hall t.w.Buggey S.Parsons t.Arnold A.Holland C.Pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

the ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.the Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.the shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s van Allen Belts.therefore,two radiation environments can be approximated based on the shutter door position:open and closed.the instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two environments.Due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.the results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being galactic Cosmic Rays(gCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.this is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the gCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

进一步改善城市网-厂-水体污水系统升级改造和运行效率的四点看法

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给水排水 2024年第4期50卷 137-144页

作者：曹业始 KROISS H van LOOSDRECHt M DAIggER g t 中持新概念环境发展宜兴有限公司宜兴214213 维也纳工业大学水质和资源管理研究所奥地利维也纳1040 代尔夫特理工大学生物技术系荷兰代尔夫特2629HZ 密歇根大学土木和环境工程系美国密歇根州48109

2022年,《深入打好城市黑臭水体治理攻坚战实施方案》发布,要求努力解决河流雨后黑臭和雨季河流断面水质下降问题,力争到2025年,进水BOD浓度高于100毫克/升的城市生活污水处理厂规模占比达90%以上,城市生活污水集中收集率达到70%以上。... 详细信息

2022年,《深入打好城市黑臭水体治理攻坚战实施方案》发布,要求努力解决河流雨后黑臭和雨季河流断面水质下降问题,力争到2025年,进水BOD浓度高于100毫克/升的城市生活污水处理厂规模占比达90%以上,城市生活污水集中收集率达到70%以上。水行业正面临着防止雨后河流返黑和改善雨季河流水质等新任务。因此,结合近年来成绩、实践和欧美的经验教训,提出和讨论了与进一步改善网-厂-水体城市污水系统升级改造及运行效率相关的四个问题:分流制管网有没有外(雨)水入侵和溢流、污水处理厂的进水浓度应多高、为什么部分污水处理厂需局部扩容、为什么污水管道中流速低于自净流速,并在此基础上,对相关工作提出了建议。

关键词：城市污水系统污水管网外水入侵雨水溢流污水浓度污水处理厂扩容水环境容量

MicroRNAs in hepatocellular carcinoma treatment:Charting the path forward

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world Journal of gastroenterology 2024年第11期30卷 1470-1474页

作者： Hong t Lin Antonio F Alvarez Castaneda Somashekar g Krishna Khalid Mumtaz Division of gastroenterology Hepatology and NutritionDepartment of MedicineThe Ohio State University Wexner Medical CenterColumbusOH 43210United States

MicroRNAs(miRNAs)are recognized for their involvement in the regulation of gene expression and exhibit significant potential in both the prognostic assessment and treatment of hepatocellular carcinoma(HCC).HCC,like other tumors,seldom occurs in isolation;instead,it evolves within a microenvironment featuring oncogenic and tumor-suppressive elements.when combined with suitable delivery vehicles,miRNA technology provides the capability to directly engage with these elements,thereby hindering tumor formation and progression.Ongoing research in this domain holds the promise of enabling a more efficacious and multi-modal treatment approach for HCC in the near future.

关键词： Hepatocellular carcinoma tumor microenvironment MicroRNA Mesenchymal stem cell Exosome

Metabolic syndrome and the urinary microbiome of patients undergoing percutaneous nephrolithotomy

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Asian Journal of Urology 2024年第2期11卷 316-323页

作者： Ryan A.Dornbier Chirag P.Doshi Shalin C.Desai Petar Bajic Michelle van Kuiken Mark Khemmani Ahmer V.Farooq Larissa Bresler thomas M.t.turk Alan J.wolfe Kristin g.Baldea Loyola University Medical Center Department of UrologyMaywoodILUSA Loyola University Chicago Department of Microbiology and ImmunologyMaywoodILUSA

Objective:to identify possible stone-promoting microbes,we compared the profiles of microbes grown from stones of patients with and without metabolic syndrome(MetS).the association between MetS and urinary stone disease is well established,but the exact pathophysiologic relationship remains unknown.Recent evidence suggests urinary tract dysbiosis may lead to increased nephrolithiasis risk.Methods:At the time of percutaneous nephrolithotomy,bladder urine and stone fragments were collected from patients with and without MetS.Both sample types were subjected to expanded quantitative urine culture(EQUC)and 16 S ribosomal RNA gene sequencing.Results:Fifty-seven patients included 12 controls(21.1%)and 45 MetS patients(78.9%).Both cohorts were similar with respect to demographics and non-MetS comorbidities.No controls had uric acid stone composition.By EQUC,bacteria were detected more frequently in MetS stones(42.2%)compared to controls(8.3%)(p=0.041).Bacteria also were more abundant in stones of MetS patients compared to controls.to validate our EQUC results,we performed 16 S ribosomal RNA gene sequencing.In 12/16(75.0%)sequence-positive stones,EQUC reliably isolated at least one species of the sequenced genera.Bacteria were detected in both“infectious”and“non-infectious”stone compositions.Conclusion:Bacteria are more common and more abundant in MetS stones than control stones.Our findings support a role for bacteria in urinary stone disease for patients with MetS regardless of stone composition.

关键词： Nephrolithiasis Urolithiasis Metabolic syndrome Urinary microbiome Percutaneous nephrolithotomy

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE M.t.MUNIR g.J.wENg K.Y.RHEE Biomaterials and tissue Engineering Research group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and technology American University of the Middle EastEgaila 54200Kuwait Department of Mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of Mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously reported.the contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact diameter.the developed model's accuracy is verified through numerous experimental measurements.to further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are analyzed.Notably,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling size.the dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/m.An increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's conductivity.Furthermore,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

Heavy metal pollution of river water and eco-friendly remediation using potent microalgal species

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water Science and Engineering 2024年第1期17卷 41-50页

作者： Amudham Radha Amal Raj Prabhakaran Mylsamy V.Sivasankar B.Sathish Kumar Kiyoshi Omine t.g.Sunitha Phycological Research Laboratory Research Department of BotanyPachaiyappa's College(Affliated to University of Madras)Chennai 600030India Research Department of Chemistry Pachaiyappa's College(Affliated to University of Madras)Chennai 600030India Department of Botany Sri Vidya Mandir Arts&Science College(Autonomous)KatteriUthangarai 636902India Department of Civil Engineering School of Engineering.Nagasaki UniversityNagasaki-Daigaku1-14 Bunkyo-machiNagasaki 8528521Japan

Pollution of rivers is mainly caused by anthropogenic activities such as discharge of effluent from industrial facilities,maintenance of sewage/effluent treatment plants,and dumping of solid waste on river banks.this study dealt with the pollution issues of the Cooum River in the well-known city of Chennai in South India.water samples from 27 locations were collected and analyzed for 12 elements,including Ba,B,and Al,as well as heavy metals such as Pb,Cr,Mn,Fe,Co,Ni,Cu,Zn,and Cd.the samples showed levels of these elements that exceeded world Health Organization recommendations.Pearson correlation analysis revealed the inter-dependency among elements,and the contribution of each element based on factor loadings showed its percentage contribution compared to others.water samples from six significant locations were chosen for remediation with three algae:Chlorella vulgaris,Scenedesmus dimorphus,and Phormedium sp.the uptake of pollutants led to the continuous growth of algae during the incubation period of 15 d,effectively removing heavy metals from the river water.the increasing levels of algal counts and the chlorophyll a content confirmed the algal growth during the incubation period,followed by a declining stage after the incubation period.the scanning electron microscopic images of algae before and after the remediation showed no remarkable modification of morphological patterns.this study showed that the uptake of heavy metals using algae is an effective water pollution remediation measure,making the process practicable in the field on a large scale in the near future.

关键词： Heavy metal Cooum river Phycoremediation Microalgae Factor analysis