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Influence of Methane-Hydrogen Mixture characteristics on compressor Vibrations

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1031-1043页

作者： Vladimir ya.Modorskii Ivan e.cherepanov High Performance computing center Perm National Research Polytechnic UniversityPerm614990Russia

A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation,storage, etc., are adequately resolved. currently, however, it is possible to use methane-hydrogen *** gas can be transported using a pipeline system with the required pressure being maintained by gascompression stations. This method, however, is affected by some problems too. compressors emergency stopscan be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibrationamplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth seals can lead to increasedvibrations. This paper presents the numerical simulation of rotor oscillations taking into account a gas-dynamicload. The influence of a transported mixture on the oscillatory process is investigated. Mixtures consisting ofmethane and hydrogen in various proportions and an air mixture are considered. The results are discussed forvarious operating pressures and include the rotor motion trajectories and oscillation frequency spectra obtainednumerically. It is shown that the gas mixture composition has a significant effect on the oscillations and theiroccurrence. Hydrogen as a working fluid reduces the vibration amplitude. Operating a compressor with hydrogenleads to a decrease in the resonant frequency, bringing it closer to the operating one. However, the operatingpressure at which maximum oscillations are observed depends slightly on the gas mixture composition.

关键词： Seal stabilities vibration FSI cFD multiphase flows hydrogen

Interactions between maternal parity and feed additives drive the composition of pig gut microbiomes in the post‑weaning period

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1241-1257页

作者： Kayla Law eduardo Rosa Medina Garcia chad Hastad Deborah Murray Pedro e.Urriola Andres gomez Department of Animal Science University of Minnesota1364 Eckles AvenueSaint PaulMN 55108USA New Fashion Pork 164 Industrial ParkwayJacksonMN 56143USA

Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare *** challenges disproportionately impact the offspring of primiparous sows compared to those of mul-tiparous *** is known regarding potential interactions between parity and feed additives in the post-weaning period and their effects on nursery pig ***,the objective of this study was to investigate the effects of maternal parity on sow and offspring microbiomes and the influence of sow parity on pig fecal microbi-ome and performance in response to a prebiotic *** weaning,piglets were allotted into three treat-ment groups:a standard nursery diet including pharmacological doses of Zn and cu(con),a group fed a commercial prebiotic only(Preb)based on an Aspergillus oryzae fermentation extract,and a group fed the same prebiotic plus Zn and cu(Preb+Zncu).Results Although there were no differences in vaginal microbiome composition between primiparous and mul-tiparous sows,fecal microbiome composition was different(R^(2)=0.02,P=0.03).The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared to multiparous offspring at d 0 and d 21 post-weaning(Perences in community composition observed at d 21(R^(2)=0.03,P=0.04).When analyzing the effects of maternal parity within each treatment,only the Preb diet triggered significant microbiome distinc-tions between primiparous and multiparous offspring(d 21:R^(2)=0.13,P=0.01;d 42:R^(2)=0.19,P=0.001).composi-tional differences in pig fecal microbiomes between treatments were observed only at d 21(R^(2)=0.12,P=0.001).Pigs in the con group gained significantly more weight throughout the nursery period when compared to those in the Preb+Zncu *** Nursery pig gut microbiome composition was influenced by supplementation with an Aspergillus oryzae fermentation extract,with varying effects on performance

关键词： Aspergillus prebiotic copper Feed additives Maternal Nursery pig microbiome Parity Swine microbiome Trace minerals Zinc

FPR1 Antagonist (BOc-MLF) Inhibits Amniotic epithelial-mesenchymal Transition

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current Medical Science 2024年第1期44卷 187-194页

作者： Xiao-mei HUANG e LIAO Jun-qun LIAO ya-ling LIU Yong SHAO Department of Obstetrics and Gynecology The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400042China Department of Obstetrics Maternal and Child Health Hospital of Hubei ProvinceWuhan 430070China Medical Laboratory Science The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400042China Department of Obstetrics Yubei Maternity and Child Healthcare HospitalChongqing 400042China

Objective:Premature rupture of membranes(PROM)is a common pregnancy disorder that is closely associated with structural weakening of fetal *** have found that formyl peptide receptor 1(FPR1)activates inflammatory pathways and amniotic epithelial-mesenchymal transition(eMT),stimulates collagen degradation,and leads to membrane weakening and membrane *** purpose of this study was to investigate the anti-inflammatory and eMT inhibitory effects of FPR1 antagonist(BOc-MLF)to provide a basis for clinical prevention of ***:The relationship between PROM,FPR1,and eMT was analyzed in human fetal membrane tissue and plasma samples using Western blotting,PcR,Masson staining,and eLISA ***(LPS)was used to establish a fetal membrane inflammation model in pregnant rats,and BOc-MLF was used to treat the LPS rat *** detected interleukin(IL)-6 in blood from the rat hearts to determine whether the inflammatory model was successful and whether the anti-inflammatory treatment was *** used electron microscopy to analyze the structure and collagen expression of rat fetal ***:Western blotting,PcR and Masson staining indicated that the expression of FPR1 was significantly increased,the expression of collagen was decreased,and eMT appeared in *** rat model indicated that LPS caused the collapse of fetal membrane epithelial cells,increased intercellular gaps,and decreased ***-MLF promoted an increase in fetal membrane collagen,inhibited eMT,and reduced the weakening of fetal ***:The expression of FPR1 in the fetal membrane of PROM was significantly increased,and eMT of the amniotic membrane was ***-MLF can treat inflammation and inhibit amniotic eMT.

关键词： formyl peptide receptor 1 BOc-MLF epithelial-mesenchymal transition premature rupture of membranes

Fabricating functionally graded Fe-cr-co permanent magnetic alloys via laser powder bed fusion

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Journal of Iron and Steel Research(International) 2024年第3期31卷 729-737页

作者： ya-zhou He ya-qing Hou Peng Shen Hao Zhang Dong Zhou Hang Su central Iron and Steel Research Institute co. Ltd.Beijing 100081China Material Digital R&D center China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China

Laser powder bed fusion(LPBF)in-situ alloying technology offers the possibility to construct gradient materials with varied structures and *** graded Fe-cr-co permanent magnetic alloys were fabricated by LPBF and in-situ alloying mixed powders of Fe,cr,and co *** effects of different Fe,cr and co contents on the microstructure,magnetic properties and hardness of Fe-cr-co alloys prepared by LPBF were *** as-built Fe-cr-co alloys present a single body-centered-cubic phase and have a homogeneous distribution of *** mechanical properties and magnetic properties of the compositionally graded sample show a gradient *** the increase in cr content,the Vickers hardness of the sample increases,and the saturation magnetization of the sample *** optimal magnetic properties in an isotropic state are given as coercivity HcB=21.65 kA/m,remanence Br=0.70 T and energy product(BH)_(max)=5.35 kJ/m^(3),which are comparable to or higher than the reported magnetic properties in an isotropic state prepared by traditional powder *** in-situ alloying technology has the potential to further explore Fe-cr-co magnetic materials,such as those consisting of multiple or more constituent elements,and to maximize the compositional flexibility of magnetic materials.

关键词： Fe-cr-co alloy Laser powder bed fusion In-situ alloying Functional material Magnetic property

High-temperature wetting behavior between slag and refractory

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1304-1319页

作者： Yong-xin Wang ya-ge Li ya-bo Gao Zhong Huang Hai-jun Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Slag corrosion is one of the main factors of the damage of refractory,and its primary manifestations involve the melting of refractory in slag and the slag penetration into refractory,both of which are highly related to the wetting behavior between slag and *** high-temperature wettability could be characterized by parameters including the surface tension,adhesion work,and spreading coefficient of the slag on refractory surface,and it could be suppressed by altering the slag/refractory interface,thus resulting in an improved anti-corrosion *** this,the key knowledges of the slag corrosion,theory of wetting behavior and test of high-temperature contact angle were firstly ***,the major factors influencing the high-temperature slag wetting behavior were discussed based on the aspects of slag composition,refractory composition,and surface ***,the future research direction was proposed in this field.

关键词： High-temperature wetting Refractory Slag corrosion Surface tension

Non-dimensional analysis on blast wave propagation in foam concrete:Minimum thickness to avoid stress enhancement

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Defence Technology（防务技术） 2024年第6期36卷 30-46页

作者： ya yang Xiangzhen Kong Qin Fang State Key Laboratory of Disaster Prevention&Mitigation of explosion&Impact Army Engineering University of PLANanjing 210007JiangsuChina

Foam concrete is a prospective material in defense engineering to protect structures due to its high energy absorption capability resulted from the long plateau ***,stress enhancement rather than stress mitigation may happen when foam concrete is used as sacrificial claddings placed in the path of an incoming blast *** investigate this interesting phenomenon,a one-dimensional difference model for blast wave propagation in foam concrete is firstly proposed and numerically solved by improving the second-order Godunov *** difference model and numerical algorithm are validated against experimental results including both the stress mitigation and the stress *** difference model is then used to numerically analyze the blast wave propagation and deformation of material in which the effects of blast loads,stress-strain relation and length of foam concrete are *** particular,the concept of minimum thickness of foam concrete to avoid stress enhancement is ***,non-dimensional analysis on the minimum thickness is conducted and an empirical formula is proposed by curve-fitting the numerical data,which can provide a reference for the application of foam concrete in defense engineering.

关键词： Foam concrete Blast wave propagation Non-dimensional analysis Stress enhancement

One more step to realistic cO_(2) reduction reactions——geometric structures evolutions at gas-solid interface

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Rare Metals 2024年第2期43卷 849-852页

作者： ya-Qiang Xie Xin Yu Ting Wang college of the environment and ecology Xiamen UniversityXiamen361102China

A rational design of copper(cu)nanocatalyst is critical to the efficient carbon dioxide(cO_(2))conversion toward c1/c2 chemical ***,the lack of actual information on the vicinal cu interfaces hinders the intrinsic activitystructure correlation *** with atomic-scale in situ characterizations(AP-STM and synchrotron-based AP-XPS),Park and co-workers study and identify the adsorbate-driven morphological evolution of cu nanoclusters on the cu(997)surface,providing real-space evidence for the critical role of vicinal structures on cu *** observed surface roughening trends caused by dissociated atomic oxygen and cO adsorbates subsequently affect the result of successive catalytic reactions to produce critical intermediates,such as carbonate and formate,during the cO_(2)reduction reaction.

关键词： reaction critical rational

clinical usefulness of the baby vision test in young children and its correlation with the Snellen chart

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International Journal of Ophthalmology(english edition) 2024年第2期17卷 348-352页

作者： ya-Lan Wang Jia-Jun Wang Xi-cong Lou Han Zou Yun-e Zhao The eye Hospital of Wenzhou Medical University Hangzhou 310000Zhejiang ProvinceChina National clinical Research center for Ocular Diseases Wenzhou 325027Zhejiang ProvinceChina

AIM:To investigate the efficacy of a new visual acuity(VA)screening method,the baby vision test for young ***:A total 105 eyes of 65 children aged 2-8y were included in the *** testing was conducted using a standardized recognition acuity chart(Snellen visual chart:at 3 m)and the baby vision model *** baby vision device includes a screen,a near infrared camera and a *** were seated at a measured distance of 33-40 cm from a display for *** was estimated according to the highest resolution the children could *** VA data were converted to logarithm of the minimum angle of resolution(logMAR)for statistical *** VA results for each child were recorded and analyzed for ***:The mean VA measured using the Snellen visual chart was 0.62±0.32,and that assessed using the baby vision test was 0.66±*** 95%limit of agreement was-0.609 to 0.695,with 95.2%(100/105)plots within the 95%limits of *** values of the baby vision test were significantly correlated with those of the Snellen chart(R=0.274,P=0.005).cONcLUSION:The baby vision test can be used as a relatively reliable method for estimating VA in young *** new acuity assessment might be a valid predictor of optotype-measured acuity later in preverbal children.

关键词： baby vision test acuity assessment fix-and-follow system Snellen chart

characteristics and geological significance of the stress state of the lithosphere in the Qinghai-Tibetan Plateau and its neighboring areas

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Science china earth Sciences 2024年第6期67卷 1836-1855页

作者： Qianwen ZHANG ya XU Wei cHU Shupeng LU Key Lab of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China college of earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The present-day lithospheric stress state of the Qinghai-Tibetan Plateau and neighboring areas is controlled by both the lithosphere itself and the underlying *** other words,the stress is affected by the gravitational potential energy(GPe)difference caused by the change in the density distribution within the lithosphere and the drag force on the base of the lithosphere caused by mantle *** study of the lithospheric stress state plays an important role in further understanding the dynamic background and mechanism for the evolution of the Qinghai-Tibetan *** this study,the crust1.0 crustal density model combined with the S40RTS mantle shear wave velocity variation model was used to calculate the *** eGM2008gravity field model was used to calculate the drag force from mantle convection at the base of the *** lithospheric and joint stress fields of the two sources were obtained by solving the force balance under the thin sheet *** way,we could comprehensively analyze the characteristics of the stress state within the *** regions were classified according to the GPe stress field,mantle drag force stress field,the relative magnitude of the two stress fields,and correlation between the two stress fields and surface *** lithospheric stress fields of the Tarim Basin and other stable blocks are mainly controlled by the GPe *** lithospheric stress field in the collision zone between the Indian Plate and the QinghaiTibetan Plateau is predominantly controlled by the deep mantle drag *** lithospheric stress field in the interior of the Plateau is controlled by both GPe and mantle *** correlation between the lithospheric stress field and surface deformation at the southeast margin of the Qinghai-Tibetan Plateau is *** is hypothesized that the presence of lower crustal flow with lower effective viscosity leads to crust-mantle decoupling,and the mantle drag force has a weaker influe

关键词： Qinghai-Tibetan Plateau Gravitational potential energy Mantle convection Lithospheric deviatoric stress field GPS strain rate field