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1.
Thermodynamics of contact angle phenomena is strongly affected by the presence of thin liquid films. However, at present, studies for CO2/brine/mineral systems only consider the films apart from contact angles. In this paper, molecular dynamics (MD) simulations have been performed to simultaneously investigate the interrelationship between water film thicknesses and water contact angles. Two types of contact angles were considered namely Young’s contact angle (no water film is present) and contact angle with film (a stable film is present). The results showed that as Young’s contact angle increased, film thickness decreased which leading to increasing of contact angle with film. The effects of CO2-mineral pre-contact have also been investigated and it has been found that on mediate hydrophilic surfaces (Q3), water films were present when CO2 droplets were placed above the surfaces, however, water films were absent when CO2 droplets directly contact with the surfaces. This phenomenon implies that water films on mineral surfaces have a possibility to rupture and a film rupture mechanism for CO2 adhesion on hydrated mineral surfaces was proposed. These results may provide new information on interactions among CO2, water/brine and mineral to better understand the behaviour of CO2 during geologic sequestration.  相似文献   

2.
Layered MoS2 prepared by liquid‐phase exfoliation has been blended with single‐walled carbon nanotubes (SWNTs) to form novel composite thin films for lithium battery applications. The films were formed by vacuum filtration of blended dispersions onto nitrocellulose membranes. The resulting composite films were transferred onto Cu foil electrodes via a facile filtration/wet transfer technique from nitrocellulose membranes. The morphology of the film was characterised by field emission scanning electron microscopy, which suggests that the MoS2‐SWNT composite film shows good adherence to the Cu foil substrate. The MoS2‐SWNT composite thin films show strong electrochemical performance at different charge‐discharge rates. The capacity of a MoS2‐SWNT composite film with thickness of 1 μm is approximately 992 mAh g?1 after 100 cycles. The morphology study showed that the MoS2‐SWNT thin film retains structural integrity after 100 cycles, while the MoS2 thin film without SWNTs displays significant cracking. In addition, the novel composite thin film preparation and transfer protocols developed in this study could be extended to the preparation of various layered‐material‐based composite films, with the potential for new device designs for energy applications.  相似文献   

3.
Slush nitrogen (SN2) is a mixture of solid nitrogen and liquid nitrogen, with an average temperature of −207 °C. To investigate whether plunging a French plastic straw (commonly used for sperm cryopreservation) in SN2 substantially increases cooling rates with respect to liquid nitrogen (LN2), a numerical simulation of the heat conduction equation with convective boundary condition was used to predict cooling rates. Calculations performed using heat transfer coefficients in the range of film boiling confirmed the main benefit of plunging a straw in slush over LN2 did not arise from their temperature difference (−207 vs. −196 °C), but rather from an increase in the external heat transfer coefficient. Numerical simulations using high heat transfer (h) coefficients (assumed to prevail in SN2) suggested that plunging in SN2 would increase cooling rates of French straw. This increase of cooling rates was attributed to a less or null film boiling responsible for low heat transfer coefficients in liquid nitrogen when the straw is placed in the solid-liquid mixture or slush. In addition, predicted cooling rates of French straws in SN2 tended to level-off for high h values, suggesting heat transfer was dictated by heat conduction within the liquid filled plastic straw.  相似文献   

4.
Development of a simple method for preparation of stable open tubular (OT) columns for proteins separation by capillary electrochromatography is still challenging. In this work, the titanium oxide (TiO2) nanoparticles coated OT column was successfully prepared for separation of proteins by capillary electrochromatography. The polydopamine (PDA) film was first formed in the inner surface of a fused-silica capillary by the self-polymerization of dopamine under alkaline conditions. Then the TiO2 coating was deposited onto the surface of pre-modified capillary with PDA by a liquid phase deposition process. The plentifully active hydroxyl groups in PDA coating can chelate with Ti4+ to boost the nucleation and growth of TiO2 film. The as-prepared TiO2 coated OT column was characterized by scanning electron microscopy and measurement of electroosmotic flow. Furthermore, the influence of liquid phase deposition time on the TiO2 coating was investigated. The TiO2 coated OT column was used for successful separation of two variants of β-lactoglobulin and eight glycoisoforms of ovalbumin. The column demonstrated good repeatability and stability. The relative standard deviations of migration times of proteins representing run-to-run, day-to-day, and column-to-column were less than 3.7%. Moreover, the application of the column was verified by successful separation of acidic proteins in egg white.  相似文献   

5.
Cytochrome b5 has been incorporated into phospholipid monolayers at the air/water interface (Langmuir films). Protein incorporation was followed by monitoring changes in surface pressure at constant film area or by measuring film area changes at constant surface pressure. It was possible to deposit proteolipid films on solid substrates using the Langmuir-Blodgett technique. Using the homologous series of phosphatidylcholines, C10:0–C22:0, it was found that increasing chain-length led to increased cytochrome penetration into the surface film. 125I-labelled cytochrome b5 was used to quantify the degree of protein uptake into the film. Phospholipid/protein ratios of 32 and 60 were determined for dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylethanolamine, respectively. A molecular area of 790 Å2 was calculated for the hydrophobic segment of cytochrome b5. The results are discussed with reference to other work on protein-phospholipid interactions, in particular to studies on cytochrome b5-liposome systems.  相似文献   

6.
Thin film solar cells based on co‐evaporated Cu(In,Ga)Se2 absorber films present the highest efficiencies among current polycrystalline thin‐film technologies. Thanks to the development of a novel experimental setup for in situ growth studies, it was possible to follow the formation of the crystalline phases during such deposition processes for the first time. This synchrotron‐based energy‐dispersive X‐ray diffraction and fluorescence setup is suited for real‐time studies of thin film vapor deposition processes. Focusing on the growth of CuInSe2 and CuGaSe2 fabricated by three‐stage processing, we find that the phase transitions in the Cu‐In‐Se system follow the reported pseudo‐binary In2Se3‐Cu2Se phase diagram. This requires a transformation of the Se sublattice during the incorporation of Cu‐Se into the In2Se3 precursor film from the first process stage. In the Cu‐Ga‐Se system, besides an increase in the lattice spacings, we observe no transformation of the Se sublattice. Furthermore, the structural defects of the Ga‐Se precursor film are preserved until the CuGaSe2 stoichiometry is reached. By means of model calculations of the fluorescence signals, we confirm in both systems the segregation of Cu2Se at the surface near a concentration of 25 at.% Cu shortly after the recrystallization of the films. The modeling also reveals that Cu2Se penetrates into the CuInSe2 film, whereas it remains at the surface of the CuGaSe2 film.  相似文献   

7.
A molecular dynamics (MD) study is carried out to reveal the phenomenon about the normal and explosive boiling of ultra-thin liquid argon film absorbed on MoS2 surface with different wetting conditions. The three-phase molecular system is composed of a solid MoS2 wall, a liquid argon film and a vapour argon region. Initially, the three-phase simulated system is thermally equilibrated at a low temperature. Then the MoS2 heat source is suddenly heated up to two different high temperatures those far above critical point of liquid argon, and the argon experienced a phase transition process in the NVE ensemble. The simulation results show that the good wetting properties and high heat source temperature dramatically enhance phase transition efficiency, accelerating the heat transfer rate, shortening the boiling time, and increasing the evaporation rate, and they have remarkable effects on temperature and pressure histories, density distribution during whole boiling process. Explosive boiling is more likely to occur at high superheated degree, but evaporation occurs at low superheated degree. In addition, at a high superheated degree, it can be conclude from the simulation results that the better wetting properties of the solid-liquid interface is, the shorter time of the explosive boiling is needed.  相似文献   

8.
The rate of dissolution and dehydration of CO2 in a liquid model system was investigated. Components in the model system established the main conditions which may exist, in the extracellular space of a microbiological culture liquid. The charge in voltage of a glass electrode was measured which indicated the formation of H+ ions in the H2CO3 ? HCO H+ reaction. The rate of CO2 hydration increased with the increase of temperature from 0 to 40°C. Likewise the equilibrium of the reaction was shifted towards the forward reaction. Similar results were observed when the tip velocity of the impeller was increased. Data suggest that agitation promotes the dissolution of CO2 in the culture liquid through the reduction of gas-liquid film resistance in the diffusion of this gas. The rate of hydration of CO2 into the bulk of the liquid was independent of pCO2 above the surface of the liquid but depended on pCO2 in the gas bubble within the liquid. The concentration of HCO was, furthermore, influenced by the buffer components, buffer capacity, and the viscosity of the system. Since pCO2 and the HCO concentration in the extracellular space depend on both physical and chemical factors, the ventilation of a culture liquid necessitates both exhaust of CO2 from the gas bubbles of the culture broth and shift of the H2CO3 ? HCO + H+ reaction towards the backward direction.  相似文献   

9.
A small molecular metal‐chelate complex, tris(8‐hydroxyquinoline‐5‐sulfonic acid) aluminum (AlQSA3), that has three sulfonic acid groups per molecule leading to an excellent solubility in water is reported as a liquid‐free perfect solid‐state electrolyte for flexible film‐type all‐solid‐state energy storage devices. The AlQSA3 material is synthesized by one‐step reaction of aluminum triisopropoxide and 8‐hydroxyquinoline‐5‐sulfonic acid. The aqueous solutions of AlQSA3 are applied to fabricate flexible film‐type all‐solid state electric double layer capacitors with indium‐tin oxide thin film electrodes. The ion conductivity of the AlQSA3 film reaches 0.116 mS cm?1, while a pronounced hysteresis are obtained in the cyclic voltammetry measurement. The AlQSA3 film capacitors exhibit an output voltage of 1.5 V at 20 μA cm?2, which is considerably stable by the repeated operation. In particular, the peak output voltage is well kept even after 180° bending for 500 times in the case of the flexible AlQSA3 film capacitors.  相似文献   

10.
Summary To overcome various disadvantages of conventional culture vessls for plant micropropagation, we previously developed the photoautotrophic micropropagation technique, with special mention for the first practical film culture system, the ‘Miracle Pack’ (MP), which was made of fluorocarbon polymer film (Neoflo? PFA film) and supported by a polycarbonate frame. While the PFA film has superior thermal stability, high light transmittance and high gas permeability, making the MP system (MP-PFA) superior to conventional culture vessels for the micropropagation of various plant species, its high cost is a disadvantage. In this study, a possible alternative of lower-cost OTP? film made of TPX (4-methyl-1-pentane polymer) and CPP (a polypropylene), which possesses similar characteristics to PFA film, is evaluated to develop a novel disposable film culture vesel, termed ‘Vitron’, for culturing Eucalyptus (urophylla x grandis), plantlets. The three film culture systems, MP-PFA, MP-OTP (MP with OTP film), and Vitron, were placed under CO2 enrichment, low photosynthetic photon flux density (PPFD; 45 μmol m−2 s−1), and sugar-free medium, using phenol resin foam (Oasis?) as a substrate. In vitro and ex vitro growth and development of Eucalyptus shoots from the four-leaf stage to the rooting stage were compared for all three culture systems. The effects of the duration and concentration of CO2 enrichments on in vitro growth of Eucalyptus cultured in the Vitron film system were also examined. The best growth and quality of Eucalyptus plantlets was obtained for the Vitron vessel placed in 3000 ppm CO2 enrichment for 24 hours per day at low PPFD with sugar-free liquid medium and Oasis as substate. Results of this study suggest that the novel Vitron culture system is suitable for the photoautotrophic micropropagation of Eucalyptus. These authors contributed equally to the research results.  相似文献   

11.
Neutron reflectivities of phosphatidylcholine monolayers in the liquid condensed (LC) phase on ultrapure H2O and D2O subphases have been measured on a Langmuir film balance. Using a dedicated liquid surface reflectometer, reflectivities down to R = 10-6 in the momentum transfer range Qz = 0-0.4 Å-1 were accessed.

In a new approach, by refining neutron reflectivity data from chain-perdeuterated DPPC-d62 in combination with x-ray measurements on the same monolayer under similar conditions it is shown that the two techniques mutually complement one another. This analysis leads to a detailed conception of the interface structure. It is found that in the LC phase (which is analogous to the Lβ, phase in vesicle dispersions) the head group is interpenetrated with subphase water (4 ± 2.5 molecules per lipid) and the average tilt angle of the hydrophobic chains from the surface normal is 33 ± 3 degrees.

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12.
A rapid quantitation of proteoglycan synthesis distribution in intervertebral disc and endplates is described. Tissue blocks of disc (C7-Th1) in the midsagittal plane from ten female beagles were incubated in the presence of 35SO4 and prepared as histological slides. For comparison, sulphate incorporation rates in the C5–C6 discs were assayed by liquid scintillation. Autoradiographic film exposed against the labelled sections was developed and digitized for image analysis using a 256 grey level flat bed table scanner connected to a microcomputer. The film density versus dpm (disintegrations per minute) calibration was performed using a set of 35SO4-labelled glycosaminoglycan standards applied on the same film. Since section thickness, dpm calibration of the film density and the specific activity of sulphate in the medium were known, the incorporations per tissue volume could be calculated. The average incorporation rates of the anterior and posterior annulus fibrosus, nucleus pulposus and vertebral endplates were 5.2±0.9, 5.2±0.8, 4.5±0.6 and 4.1±0.8 pmol/mm3 per h (±SE, n=10), respectively and closely corresponded to those obtained by liquid scintillation. This method offers a convenient and reproducible way to measure the rate of proteoglycan synthesis in large tissue sections but also in thin cartilaginous tissues such as the vertebral endplate.  相似文献   

13.
The photovoltaic performance of perovskite solar cells (PVSCs) is extremely dependent on the morphology and crystallization of the perovskite film, which is affected by the deposition method. In this work, a new approach is demonstrated for forming the PbI2 nanostructure and the use of high CH3NH3I concentration which are adopted to form high‐quality (smooth and PbI2 residue‐free) perovskite film with better photovoltaic performances. On the one hand, self‐assembled porous PbI2 is formed by incorporating small amount of rationally chosen additives into the PbI2 precursor solutions, which significantly facilitate the conversion of perovskite without any PbI2 residue. On the other hand, by employing a relatively high CH3NH3I concentration, a firmly crystallized and uniform CH3NH3PbI3 film is formed. As a result, a promising power conversion efficiency of 16.21% is achieved in planar‐heterojunction PVSCs. Furthermore, it is experimentally demonstrated that the PbI2 residue in perovskite film has a negative effect on the long‐term stability of devices.  相似文献   

14.
Summary This paper presents results of experiments on the influence of O2 and substrate (pollutant) concentration on the overall reaction rate of a trickle-bed reactor used for biological waste gas purification. The biocatalyst was a pollutant-specific bacterial monoculture fixed on porous glass carriers. The conversion of acetone and propionaldehyde, as model pollutants that are easily soluble in water, was measured. Under constant hydrodynamic conditions (gas and liquid flow rates) the inlet pollutant concentration was varied. The O2 partial pressure in the model gas was increased to investigate the influence of O2 supply on pollutant conversion. At higher pollutant concentrations (>117 mg acetone.m-3 gas and > 150 mg propionaldehyde.m-3 gas) higher concentrations of dissolved O2 led to a significant rise in the maximum degradation capacity of the reactor. This maximum reaction rate was independent of the pollutant mass flow. It seems that the diffusion of O2 in the biofilm is rate-determining. The reaction rate at lower inlet concentrations was not affected by the improved O2 supply. Here the external mass transfer through the liquid film limits the reaction rate and the maximum separation efficiency of about 80% at a residence time of 1.2s (space velocity 3000h-1) is achieved.  相似文献   

15.
The novel [Co(C5F6HO2)2 · 2H2O · CH3(OCH2CH2)2OCH3] and [Co(C5F6HO2)2 · 2H2O · CH3(OCH2CH2)3OCH3] low-melting adducts have been synthesized and characterized by elemental analysis, IR spectroscopy, mass spectra and TG-DTG thermal measurements. The former adduct is liquid at room temperature, whilst very mild heating of the latter results in a thermal stable liquid compound. Both adducts can easily be evaporated. Deposition experiments, in a low-pressure horizontal hot-wall reactor, on optical transparent SiO2 substrates, using these precursors, result in CoO or Co3O4 films, depending on the deposition conditions. XRD measurements provide evidence that CoO and Co3O4 consist of cubic, highly oriented, (2 0 0) and (3 1 1) crystals, respectively. The mean crystallite sizes were evaluated from the XRD line broadening. Both optical spectra and resistivity measurements of Co3O4 films show that they are semi-conducting and their band-gap was determined from the optical induced transitions. The film cross section and the surface atomic composition were investigated by SEM and XPS analyses, respectively.  相似文献   

16.

In this report, Ag nanoparticles were fabricated using the single-step glancing angle deposition (SS-GLAD) technique upon In2O3/TiO2 thin film. Afterward, a detailed analysis was done for the two samples such as In2O3/TiO2 thin film and In2O3/TiO2 thin film/Ag nanoparticles, to inspect the field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), ultraviolet (UV) spectroscopy, and electrical properties. The reduction in bandgap energy for the samples of In2O3/TiO2 thin film/Ag nanoparticles (~4.16 eV) in comparison with the In2O3/TiO2 thin film (~4.28 eV) was due to trapped e–h recombination at the oxygen vacancies and electron transmission of Ag to the conduction band of the In2O3/TiO2 thin films. Moreover, under irradiation of photons Ag nanoparticles generated inorganic Ag–O compound attributable to the localized surface plasmon resonance (LSPR). Also, a?~90% high transmittance,?~60% and?~25% low reflectance in UV and visible region, fill factor (FF) of 53%, as well as power conversion efficiency (PCE) of 15.12% was observed for In2O3/TiO2 thin film/Ag nanoparticles than the In2O3/TiO2 thin film. Therefore, the use of Ag nanoparticles textured In2O3/TiO2 thin film–based device is a promising approach for the forthcoming photovoltaic applications.

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17.
S. Idei  K. Kondo 《Plant cell reports》1998,17(6-7):451-456
The effects of NO3 and BAP on organogenesis in shoot primordia of Utricularia praelonga subcultured in B5 liquid medium were studied. In B5 liquid basal medium supplemented with 24.73 mM KNO3 and 2.0 mg/l BAP the subcultured shoot primordia continuously multiplied into numerous small, globular masses, while with dilution of the KNO3 to 3 mM organogenesis was promoted. Pulse treatment of the shoot primordia with 3 mM KNO3 in B5 liquid medium for 72 h and then transplantation to the B5 basal liquid-medium induced meristemoids in this tissue. When the shoot primordia regenerated meristemoids, they never reverted back into the proliferation cycle. The addition of BAP in the B5 liquid medium with 3 mM KNO3 regulated the differentiation rate of the stems and leaves in the meristemoids induced in the masses of shoot primordia. The control produced 3 parts stems to 1 part leaves; medium with 0.02 mg/l BAP regenerated approximately 2 parts stems and 1 part leaves; that of 0.20 mg/l BAP 1 part stems and 2 parts leaves; and medium with 2.00 mg/l BAP regenerated leaves only. Received: 17 September 1997 / Revision received: 30 October 1997 / Accepted: 18 November 1997  相似文献   

18.
The effects of aliphatic hydrocarbons (n-hexadecane andn-dodecane) on the volumetric oxygen mass transfer coefficient (k L a) were studied in flat alveolar airlift reactor and continuous stirred tank reactors (CSTRs). In the flat alveolar airlift reactor, high aeration rates (>2 vvm) were required in order to obtain efficient organic-aqueous phase dispersion and reliablek L a measurements. Addition of 1% (v/v)n-hexadecane orn-dodecane increased thek l a 1.55-and 1.33-fold, respectively, compared to the control (superficial velocity: 25.8×10−3 m/s, sparger orifice diameter: 0.5 mm). Analysis of the gas-liquid interfacial areaa and the liquid film mass transfer coefficientk L suggests that the observedk L a increase was a function of the media's liquid film mass transfer. Addition of 1% (v/v)n-hexadecane orn-dodecane to analogous setups using CSTRs led to ak L a increase by a factor of 1.68 and 1.36, respectively (superficial velocity: 2.1×10−3 m/s, stirring rate: 250 rpm). These results propose that low-concentration addition of oxygen-vectors to aerobic microbial cultures has additional benefit relative to incubation in purely aqueous media.  相似文献   

19.
A series of novel biobased composite films derived from cellulose, starch and lignin were prepared from an ionic liquid (IL), 1-allyl-3-methylimidazolium chloride (AmimCl) by coagulating in a nonsolvent condition. The ionic liquid can be recycled with a high yield and purity after the green film was prepared. The uniform design method was applied to investigate mechanical properties of the biobased composite films. The effect of each component and their associated interactive effects were investigated. The experimental results showed that contents of cellulose, lignin and starch had a significant influence on the mechanical properties of composite films. The composite films showed relatively excellent mechanical properties in dry and wet states owing to the mutual property supplement of different components. The composite films were characterized via FT-IR, X-ray diffraction (XRD) and scanning electron microscope (SEM). Their thermal stability and gas permeability were also investigated, and the results showed that the composite films had good thermal stability and high gas barrier capacity and give a CO2:O2 permeability ratio close to 1.  相似文献   

20.
The purpose of this study was to develop an injectable in situ liquid crystal formulation for intra-articular (IA) administration, and in situ forming a viscous liquid crystalline gel with long-term release of sinomenine hydrochloride (SMH) upon water absorption. The pseudo-ternary phase diagram of phytantriol (PT)-ethanol (ET)-water was constructed, and isotropic solutions were chosen for further optimization. The physicochemical properties of isotropic solutions were evaluated, and the phase structures of liquid crystalline gels formed by isotropic solutions in excess water were confirmed by crossed polarized light microscopy (CPLM) and small-angle X-ray scattering (SAXS). In vitro drug release studies were conducted by using a dialysis membrane diffusion method. The optimal in situ cubic liquid crystal (ISV2) (PT/ET/water, 64:16:20, w/w/w) loaded with 6 mg/g of SMH showed a suitable pH, showed to be injectable, and formed a cubic liquid crystalline gel in situ with minimum water absorption within the shortest time. The optimal ISV2 was able to sustain the drug release for 6 days. An in situ hexagonal liquid crystal (ISH2) system was prepared by addition of 5% vitamin E acetate (VitEA) into PT in the optimal ISV2 system to improve the sustained release of SMH. This ISH2 (PT/VitEA/ET/water, 60.8:3.2:16:20, w/w/w/w) was an injectable isotropic solution with a suitable pH range. The developed ISH2 was found to be able to sustain the drug release for more than 10 days and was suitable for IA injection for the treatment of rheumatoid arthritis (RA).KEY WORDS: in situ cubic liquid crystal, in situ hexagonal liquid crystal, phytantriol, sinomenine hydrochloride, sustained drug release  相似文献   

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