A Numerical Study on the Thermocapillary Migration of Droplet under Microgravity with Periodic Thermal Boundaries by Front Tracking Method

This paper mainly studied the thermocapillary migration of deformable droplets induced by periodic temperature boundary under microgravity conditions. The Finite-Difference/Front-Tracking (FD/FT) Method was used to solve the Navier-Stokes equation coupled with the energy equation, and the Continuum Surface Force (CSF) model was used to simplify the surface tension of the phase interface. The results showed that the maximum droplet migration velocity increased with the increase of temperature amplitude. And the droplet cycle period became shorter with the increase of temperature angular frequency. In the 1/4 cycle, the initial movement time of droplet decreased with the increase of temperature phase. If the phase was reversed, the initial movement direction of the droplet changed. With the increase of Reynolds number (Re), the droplet tended to maintain its motion inertia.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

The effect of fluctuating pressure gradient on the coalescence of Taylor bubble

The oscillatory coalescence phenomenon of the Taylor bubble flow subjected to the action of a fluctuating pressure gradient in the pulsating heat pipe was investigated by Front Tracking method (FTM). The effects of amplitude and frequency of fluctuating pressure, bubble size, Reynolds number (Re), and Weber number (We) on the coalescence process of bubble were studied. The results demonstrated that the lower the pulsation frequency was, the longer the period of bubble oscillation was, which could provide enough time for bubbles to drain and promoted the coalescence of the bubbles; The larger Euler number (Eu) was, the easier bubbles coalesced. On the contrary, when the Eu was small, the bubbles were difficult to coalesce in a short time; The size of the top bubble and the bottom bubble made different effects on coalescence. The increase of the length of the top bubble (Lt) was beneficial to bubble coalescence while increasing length of the bottom bubble (Lb) restrained bubble coalescence; Time required for bubble coalescence increased with the increase of Re and decreased with increasing We.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Numerical analysis of coupled Kelvin–Helmholtz and Rayleigh–Taylor instability on inclined walls

The front tracking method was used to study the 2D Kelvin–Helmholtz (K–H) instability on an inclined wall for three-component immiscible fluids. Coupled effects between K–H instability and Rayleigh–Taylor (R–T) instability were studied by analyzing the effect of inclination angle, Atwood number (At), and Richardson number (Ri) on interface evolution. The results show that the coupling of R–T instability has an important influence on the development of K–H instability. The R–T instability first affects the lower interface and then the upper interface at different inclination angles, and it is also observed that the critical time of the coupled effect is earlier with an inclined wall. The R–T instability promotes the development of upper and lower interfaces at different At numbers. In addition, the billow height increases with the increase in At number and the influence of R–T instability on the upper interface can be neglected when the dimensionless time is less than critical time t = 0.6. The R–T instability has little effect on the different surface tension in terms of Richardson number (Riσ).The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Investigation of the formation behaviors of CO2 hydrate in porous media below the freezing point

The formation process of gas hydrate is a stochastic phenomenon considered to be significant for its application in the areas such as hydrate-based technology and natural gas hydrate exploitation. The formation behaviors of CO2 hydrate were studied in porous media below the freezing point. In addition, the formation experiments were conducted in the high-pressure vessel under different temperature and pressure conditions. The formation process of CO2 hydrate showed different formation behaviors in the porous media under different experimental conditions. The results showed that the formation rate was higher in earlier stage and the largest formation rate attained 7.18 x 10(-4) mol h(-1). The influence of initial pressure on the formation rate was indistinctive in porous media below the freezing point. Particle size of the porous media played an important role in affecting the formation characteristic of CO2 hydrate below the freezing point. The results indicated that, the smaller the particle size of porous media was, the larger the formation rate and the conversion rate of CO2 hydrate. The maximum conversion rate was attained 90.61%. The results also indicated that CO2 hydrate had a good gas storage capacity in porous media below the freezing point. The gas storage capacity was close to 160 L/L in frozen quartz sand with the particle size of 250 mu m in the experiments. The relative results will provide some insight for sequestration and storage process of CO2 gas in the form of hydrates into sediments

GST family genes in jujube actively respond to phytoplasma infection

Jujube witches’ broom (JWB) caused by phytoplasma has a severely negative effect on multiple metabolisms in jujube. The GST gene family in plants participates in the regulation of a variety of biotic and abiotic stresses. This study aims to identify and reveal the changes in the jujube GST gene family in response to phytoplasma infection. Here, 70 ZjGSTs were identified in the jujube genome and divided into 8 classes. Among them, the Tau-class, including 44 genes, was the largest. Phylogenetic analysis indicated that Tau-class genes were highly conserved among species, such as Arabidopsis, cotton, chickpea, and rice. Through chromosome location analysis, 37.1% of genes were clustered, and 8 of 9 gene clusters were composed of Tau class members. Through RT-PCR, qRT-PCR and enzyme activity detection, the results showed that the expression of half (20/40) of the tested ZjGSTs was inhibited by phytoplasma infection in field and tissue culture conditions, and GST activity was also significantly reduced. In the resistant and susceptible varieties under phytoplasma infection, ZjGSTU49-ZjGSTU54 in the cluster Ⅳ showed opposite expression patterns, which may be due to functional divergence during evolution. Some upregulated genes (ZjGSTU45, ZjGSTU49, ZjGSTU59, and ZjGSTU70) might be involved in the process of jujube against JWB. The yeast two-hybrid results showed that all 6 Tau-class proteins tested could form homodimers or heterodimers. Overall, the comprehensive analysis of the jujube GST gene family revealed that ZjGSTs responded actively to phytoplasma infection. Furthermore, some screened genes (ZjGSTU24, ZjGSTU49-52, ZjGSTU70, and ZjDHAR10) will contribute to further functional studies of jujube-phytoplasma interactions

Electrochemical Properties of an Sn-Doped LATP Ceramic Electrolyte and Its Derived Sandwich-Structured Composite Solid Electrolyte

An Li1.3Al0.3SnxTi1.7−x(PO4)3 (LATP-xSn) ceramic solid electrolyte was prepared by Sn doping via a solid phase method. The results showed that adding an Sn dopant with a larger ionic radius in a concentration of x = 0.35 enabled one to equivalently substitute Ti sites in the LATP crystal structure to the maximum extent. The uniform Sn doping could produce a stable LATP structure with small grain size and improved relative density. The lattice distortion induced by Sn doping also modified the transport channels of Li ions, which promoted the increase of ionic conductivity from 5.05 × 10−5 to 4.71 × 10−4 S/cm at room temperature. The SPE/LATP-0.35Sn/SPE composite solid electrolyte with a sandwich structure was prepared by coating, which had a high ionic conductivity of 5.9 × 10−5 S/cm at room temperature, a wide electrochemical window of 4.66 V vs. Li/Li+, and a good lithium-ion migration number of 0.38. The Li||Li symmetric battery test results revealed that the composite solid electrolyte could stably perform for 500 h at 60 °C under the current density of 0.2 mA/cm2, indicating its good interface stability with metallic lithium. Moreover, the analysis of the all-solid-state LiFePO4||SPE/LATP-0.35Sn/SPE||Li battery showed that the composite solid electrolyte had good cycling stability and rate performance. Under the conditions of 60 °C and 0.2 C, stable accumulation up to 200 cycles was achieved at a capacity retention ratio of 90.5% and a coulombic efficiency of about 100% after cycling test

Fudan-xuebao / Yixue-ban

The pulsed magnetic field was employed in the study on Zn doped MgB2 bulks. A phenomenon that the slurry of Mg, Zn, B and their compounds were excited by the Lorentz force was observed in the pulsed magnetic field process. The critical current density (Jc) of Zn doped MgB2 bulks shows great anisotropic dependence on the included angle between the process field and the measurement field

The genome of Candidatus phytoplasma ziziphi provides insights into their biological characteristics

Abstract Phytoplasmas are obligate cell wall-less prokaryotic bacteria that primarily multiply in plant phloem tissue. Jujube witches’ broom (JWB) associated with phytoplasma is a destructive disease of jujube (Ziziphus jujuba Mill.). Here we report the complete ‘Candidatus Phytoplasma ziziphi’ chromosome of strain Hebei-2018, which is a circular genome of 764,108-base pairs with 735 predicted CDS. Notably, extra 19,825 bp (from 621,995 to 641,819 bp) compared to the previously reported one complements the genes involved in glycolysis, such as pdhA, pdhB, pdhC, pdhD, ackA, pduL and LDH. The synonymous codon usage bias (CUB) patterns by using comparative genomics analysis among the 9 phytoplasmas were similar for most codons. The ENc-GC3s analysis among the 9 phytoplasmas showed a greater effect under the selection on the CUBs of phytoplasmas genes than mutation and other factors. The genome exhibited a strongly reduced ability in metabolic synthesis, while the genes encoding transporter systems were well developed. The genes involved in sec-dependent protein translocation system were also identified.The expressions of nine FtsHs encoding membrane associated ATP-dependent Zn proteases and Mn-SodA with redox capacity in the Ca. P. ziziphi was positively correlated with the phytoplasma concentration. Taken together, the genome will not only expand the number of phytoplasma species and provide some new information about Ca. P. ziziphi, but also contribute to exploring its pathogenic mechanism