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A pressure-sensitive rheological origin of high friction angles of granular matter observed in NASA–MGM project

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Chinese Physics B 2024年第6期33卷 559-567页

作者：程晓辉肖世泽杨森赵乃峰 Alex Sixie Cao Department of Civil Engineering Tsinghua UniversityBeijing 100084China College of Transportation Engineering Nanjing Tech UniversityNanjing 211816China Institute of Structural Engineering ETH ZurichZurich 8092Switzerland

An abnormally high peak friction angle of Ottawa sand was observed in(National Aeronautics and Space Administration) NASA–(Mechanics of Granular Materials) MGM tests in microgravity conditions on the space shuttle. Previous investigations have been unsuccessful in providing a constitutive insight into this behavior of granular materials under extremely low effective stress conditions. Here, a recently proposed unified constitutive model for transient rheological behavior of sand and other granular materials is adopted for the analytical assessment of high peak friction angles. For the first time, this long-eluded behavior of sand is attributed to a hidden rheological transition mechanism, that is not only rate-sensitive, but also pressure-sensitive. The NASA–MGM microgravity conditions show that shear-tests of sand can be performed under abnormally low confining stress conditions. The pressure-sensitive behavior of granular shearing that is previously ignored is studied based on the μ(I) rheology and its variations. Comparisons between the model and the NASA microgravity tests demonstrate a high degree of agreement. The research is highly valid for pressure-sensitive and rate-dependent problems that occur during earthquakes, landslides, and space exploration.

关键词： granular matter microgravity pressure-sensitive NASA–MGM

3D printing in space:from mechanical structures to living tissues

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International Journal of Extreme Manufacturing 2024年第2期6卷 378-387页

作者： Mao Mao Zijie Meng Xinxin Huang Hui Zhu Lei Wang Xiaoyong Tian Jiankang He Dichen Li Bingheng Lu State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Medical Products Administration(NMPA)Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Innovation Platform(Center)for Industry-Education Integration of Medical Technology Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China Frontier Institute of Science and Technology Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Innovation Institute of Additive Manufacturing Xi’an 710000People’s Republic of China

3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fabrication,and resource constraints.Despite the obstacles posed by microgravity and extreme environments,continual advancements underscore the pivotal role of 3D printing in aerospace science.Beyond its primary function of producing space structures,3D printing contributes significantly to progress in electronics,biomedicine,and resource optimization.This perspective delves into the technological advantages,environmental challenges,development status,and opportunities of 3D printing in space.Envisioning its crucial impact,we anticipate that 3D printing will unlock innovative solutions,reshape manufacturing practices,and foster self-sufficiency in future space endeavors.

关键词： 3D printing in space space manufacturing microgravity

Numerical study on onset of oscillatory thermocapillary flow in rectangular liquid pool

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Science China(Technological Sciences) 2010年第4期53卷 1069-1076页

作者： HU WenRui,TANG ZeMei & LI Kai Key Laboratory of microgravity(National microgravity Laboratory),Institute of Mechanics,Chinese Academy of Sciences,Beijing10090,China Key Laboratory of microgravity (National microgravity Laboratory) Institute of Mechanics Chinese Academy of Sciences Beijing China

Thermocapillary flow in a rectangular liquid pool of large Prandtl fluid(Pr=105.6) is numerically studied in microgravity.Oscillatory thermocapillary flow arises when the imposed temperature difference between the sidewalls exceeds a critical value.The fluctuations of the oscillatory flow,accompanied by the propagation of the hydrothermal wave from the cold sidewall to the hot one,are much smaller than the time-averaged velocity and temperature fields.The corresponding disturbance cells arise in the centre of the liquid pool initially,and extend to the whole region with the increasing imposed temperature difference.The present study reveals the different characteristics of the oscillatory themocapillary flow in the rectangular liquid pool as compared to the cases in other configurations.

关键词： hydrothermal wave bifurcation numerical simulation microgravity

The hydrothermal wave of large-Prandtl-number fluid in a shallow cavity

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Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 787-796页

作者： TANG ZeMei & HU WenRui National microgravity Laboratory,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100080,China National microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beijing China

The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied temperature difference grows and over the critical value. The phase relationships of the disturbed velocity,temperature and pressure demonstrate that the traveling wave is driven by the disturbed tem-perature,which is named hydrothermal wave. The hydrothermal wave is so weak that the oscillatory flow field and temperature distribution can hardly be observed in the liquid layer. The exciting mechanism of hydrothermal wave is analyzed and discussed in the present paper.

关键词： hydrothermal wave, numerical simulation, microgravity The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied temperature difference grows and over the critical value. The phase relationships of the disturbed velocity, temperature and pressure demonstrate that the traveling wave is driven by the disturbed temperature, which is named hydrothermal wave. The hydrothermal wave is so weak that the oscillatory flow field and temperature distribution can hardly be observed in the liquid layer. The exciting mechanism of hydrothermal wave is analyzed and discussed in the present paper. ……

Bioeffects of microgravity and Hypergravity on Animals

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Chinese Journal of Electrical Engineering 2023年第1期9卷 29-46页

作者： Guofeng Cheng Biao Yu Chao Song Vitalii Zablotskii Xin Zhang High Magnetic Field Laboratory of Chinese Academy of Sciences(CHMFL) HFIPSCASHefei 230031China Science Island Branch of Graduate School University of Science and Technology of ChinaHefei 230036China Institute of Physics of the Czech Academy of Sciences Prague 18221Czechia International Magnetobiology Frontier Research Center Science IslandHefei 230031China

Gravity alterations in space cause significant adaptive effects on the human body,including changes to the muscular,skeletal,and vestibular systems.However,multiple factors besides gravity exist in space;therefore,it is difficult to distinguish gravity-related bioeffects from those of the other factors,including radiation.Although everything on the Earth surface is subject to gravity,gravity-induced effects are not explicitly clear.Here,different research methods that have been used in gravity alterations,including parabolic flight,diamagnetic levitation,and centrifuge,are reviewed and compared.The bioeffects that are reported to be associated with altered gravity in animals are summarized,and the potential risks of hypergravity and microgravity are discussed,with a focus on microgravity,which has been studied more extensively.It should be noted that although various microgravity and hypergravity research methods have their limitations,such as the inevitable magnetic field effects in diamagnetic levitation and short duration of parabolic flight,it is evident that ground-based clinical,animal,and cellular experiments that simulate gravity alterations have served as important and necessary complements to space research.These researches not only provide critical and fundamental biological information on the effects of gravity from biomechanics and the biophysical perspectives,but also help in developing future countermeasures for astronauts.

关键词： Gravity microgravity hypergravity bioeffects static magnetic field(SMF)

A magnetically enabled simulation of microgravity represses the auxin response during early seed germination on a microfluidic platform

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Microsystems & Nanoengineering 2022年第1期8卷 97-109页

作者： Jing Du Lin Zeng Zitong Yu Sihui Chen Xi Chen Yi Zhang Hui Yang Laboratory of Biomedical Microsystems and Nano Devices Center for Bionic Sensing and IntelligenceInstitute of Biomedical and Health EngineeringShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Center for Medical AI Institute of Biomedical and Health EngineeringShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

For plants on Earth,the phytohormone auxin is essential for gravitropism-regulated seedling establishment and plant growth.However,little is known about auxin responses under microgravity conditions due to the lack of a tool that can provide an alteration of gravity.In this paper,a microfluidic negative magnetophoretic platform is developed to levitate Arabidopsis seeds in an equilibrium plane where the applied magnetic force compensates for gravitational acceleration.With the benefit of the microfluidic platform to simulate a microgravity environment on-chip,it is found that the auxin response is significantly repressed in levitated seeds.Simulated microgravity statistically interrupts auxin responses in embryos,even after chemical-mediated auxin alterations,illustrating that auxin is a critical factor that mediates the plant response to gravity alteration.Furthermore,pretreatment with an auxin transportation inhibitor(N-1-naphthylphthalamic acid)enables a decrease in the auxin response,which is no longer affected by simulated microgravity,demonstrating that polar auxin transportation plays a vital role in gravity-regulated auxin responses.The presented microfluidic platform provides simulated microgravity conditions in an easy-to-implement manner,helping to study and elucidate how plants correspond to diverse gravity conditions;in the future,this may be developed into a versatile tool for biological study on a variety of samples.

关键词： magnetic auxin microgravity

Effects of spaceflight and simulated microgravity on microbial growth and secondary metabolism

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Military Medical Research 2018年第4期5卷 335-349页

作者： Bing Huang Dian-Geng Li Ying Huang Chang-Ting Liu Nanlou Respiratory Diseases Department Chinese PLA General Hospital/Chinese PLA Postgraduate Medical School State Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of Sciences

Spaceflight and ground-based microgravity analog experiments have suggested that microgravity can affect microbial growth and metabolism. Although the effects of microgravity and its analogs on microorganisms have been studied for more than 50 years, plausible conflicting and diverse results have frequently been reported in different experiments, especially regarding microbial growth and secondary metabolism. Until now, only the responses of a few typical microbes to microgravity have been investigated; systematic studies of the genetic and phenotypic responses of these microorganisms to microgravity in space are still insufficient due to technological and logistical hurdles. The use of different test strains and secondary metabolites in these studies appears to have caused diverse and conflicting results. Moreover, subtle changes in the extracellular microenvironments around microbial cells play a key role in the diverse responses of microbial growth and secondary metabolisms. Therefore, "indirect" effects represent a reasonable pathway to explain the occurrence of these phenomena in microorganisms. This review summarizes current knowledge on the changes in microbial growth and secondary metabolism in response to spaceflight and its analogs and discusses the diverse and conflicting results. In addition, recommendations are given for future studies on the effects of microgravity in space on microbial growth and secondary metabolism.

关键词： Microbial growth Secondary metabolism Spaceflight microgravity Simulated microgravity microgravity analogs

Bone Loss Induced by Simulated microgravity,Ionizing Radiation and/or Ultradian Rhythms in the Hindlimbs of Rats

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Biomedical and Environmental Sciences 2018年第2期31卷 126-135页

作者： ZHANG Ya Nan SHI Wen Gui LI He HUA Jun Rui FENG Xiu WEI Wen Jun WANG Ju Fang HE Jin Peng LEI Su Wen Key Laboratory of Space Radiobiology of Gansu Province&CAS Key Laboratory of Heavy Ion Radiation Biology and Medicine Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000GansuChina University of Chinese Academy of Sciences Beijing 100049China Office of Health Standards Chinese Center for Disease Control and PreventionBeijing 102206China

Objective To better understand the pathological causes of bone loss in a space environment, including microgravity, ionizing radiation, and ultradian rhythms.Methods Sprague Dawley （SD） rats were randomly divided into a baseline group, a control group, a hindlimb suspension group, a radiation group, a ultradian rhythms group and a combined-three-factor group. After four weeks of hindlimb suspension followed by X-ray exposure and/or ultradian rhythms, biomechanical properties, bone mineral density, histological analysis, microstructure parameters, and bone turnover markers were detected to evaluate bone loss in hindlimbs of rats.Results Simulated microgravity or combined-three factors treatment led to a significant decrease in the biomechanical properties of bones, reduction in bone mineral density, and deterioration of trabecular parameters. Ionizing radiation exposure also showed adverse impact while ultradian rhythms had no significant effect on these outcomes. Decrease in the concentration of the turnover markers bone alkaline phosphatase （bALP）, osteocalcin （OCN）, and tartrate-resistant acid phosphatase-5b （TRAP-Sb） in serum was in line with the changes in trabecular parameters.Conclusion Simulated microgravity is the main contributor of bone loss. Radiation also results in deleterious effects but ultradian rhythms has no significant effect. Combined-three factors treatment do not exacerbate bone loss when compared to simulated microgravity treatment alone.

关键词： Bone loss microgravity Radiation Ultradian rhythms

Mitochondrial Oxidative Stress Enhances Vasoconstriction by Altering Calcium Homeostasis in Cerebrovascular Smooth Muscle Cells under Simulated microgravity

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Biomedical and Environmental Sciences 2021年第3期34卷 203-212页

作者： LIU Zi Fan WANG Hai Ming JIANG Min WANG Lin LIN Le Jian ZHAO Yun Zhang SHAO Jun Jie ZHOU Jing Jing XIE Man Jiang LI Xin ZHANG Ran Department of Cardiovascular Medicine Chinese PLA General Hospital&Chinese PLA Medical SchoolBeijing 100853China Department of Cardiology The Eighth Medical Center of Chinese PLA General HospitalBeijing 100193China The First Clinical Medical College of Inner Mongolia Medical University Hohhot 010059Inner MongoliaChina Department of Aerospace Physiology Key Laboratory of Aerospace Medicine of Ministry of EducationFourth Military Medical UniversityXi'an 710032ShaanxiChina Division of Health services The First Medical Center of Chinese PLA General HospitalBeijing 100853China

Objective Exposure to microgravity results in postflight cardiovascular deconditioning in astronauts.Vascular oxidative stress injury and mitochondrial dysfunction have been reported during this process.To elucidate the mechanism for this condition,we investigated whether mitochondrial oxidative stress regulates calcium homeostasis and vasoconstriction in hindlimb unweighted(HU)rat cerebral arteries.Methods Three-week HU was used to simulate microgravity in rats.The contractile responses to vasoconstrictors,mitochondrial fission/fusion,Ca^(2+) distribution,inositol 1,4,5-trisphosphate receptor(IP3 R)abundance,and the activities of voltage-gated K+channels(KV)and Ca^(2+)-activated K+channels(BKCa)were examined in rat cerebral vascular smooth muscle cells(VSMCs).Results An increase of cytoplasmic Ca^(2+) and a decrease of mitochondrial/sarcoplasmic reticulum(SR)Ca^(2+) were observed in HU rat cerebral VSMCs.The abundance of fusion proteins(mitofusin 1/2[MFN1/2])and fission proteins(dynamin-related protein 1[DRP1]and fission-mitochondrial 1[FIS1])was significantly downregulated and upregulated,respectively in HU rat cerebral VSMCs.The cerebrovascular contractile responses to vasoconstrictors were enhanced in HU rats compared to control rats,and IP3 R protein/mRNA levels were significantly upregulated.The current densities and open probabilities of KV and BKCa decreased and increased,respectively.Treatment with the mitochondrial-targeted antioxidant mitoTEMPO attenuated mitochondrial fission by upregulating MFN1/2 and downregulating DRP1/FIS1.It also decreased IP3 R expression levels and restored the activities of the KV and BKCa channels.MitoTEMPO restored the Ca^(2+) distribution in VSMCs and attenuated the enhanced vasoconstriction in HU rat cerebral arteries.Conclusion The present results suggest that mitochondrial oxidative stress enhances cerebral vasoconstriction by regulating calcium homeostasis during simulated microgravity.

关键词： microgravity Mitochondrial oxidative stress Calcium homeostasis Vasoconstriction