Low-temperature conformal vacuum deposition of OLED devices using close-space sublimation

Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films as an area source to rapidly transfer the donor film to a device substrate at temperatures below 200℃.CSS is also conformal and capable of depositing on odd-shaped substrates using flexible donor media.The evaporation behaviors of organic donor films under CSS were fully characterized using model OLED materials and CSS-deposited films exhibited comparable device performances in an OLED stack to films deposited by conventional point sources.The low temperature and conformal nature of CSS,along with its high material utilization and short process time,make it a promising method for fabricating flexible OLED displays.

A Preliminary Study of Yeats' Lyrics of Sublimation

Yeats' lyrics of sublimation is one of his major concerns in his later years. Sublimation for Yeats is essentially the transmutation and elevation of bitterness and tragic facts of being into happiness, into tranquility of mind, then into the emotionless emotion, as Yeats names it as "innocence". The process of sublimation enriches the creativity of Yeats as artist when he is confronted with severity of aging spiritually and physically.

Low-Angle Grain Boundaries in Sublimation Grown 6H-SiC Crystals

High-resolution X-ray diffractometry (HRXRD) was used to assess the quality of 6H-SiC crystals grown by sublimation method. The results show the occurrence of low-angle grain boundaries (LB) is close relative to the inclination of the crystal interface. At the central faceted region with 0° inclination the crystal is of high structural perfection. However, at the region close to the facet with less than 5° inclination LB occurs slightly and at the region close to the peripheral polytype ring with more than 5° inclination LB defect occurs heavily. The density of LB can be drastically reduced by decreasing radial temperature gradient that determines the shape of the crystal growth interface.

EXPERIMENTAL STUDY ON FILM COOLING EFFECTIVENESS AND HEAT TRANSFER COEFFICIENT BY NAPHTHALENE SUBLIMATION

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In Situ Imaging of Layer-by-Layer Sublimation of Suspended Graphene

An individual suspended graphene sheet was connected to a scanning tunneling microscopy probe inside a transmission electron microscope,and Joule heated to high temperatures.At high temperatures and under electron beam irradiation,the few-layer graphene sheets were removed layer-by-layer in the viewing area until a monolayer graphene was formed.The layer-by-layer peeling was initiated at vacancies in individual graphene layers.The vacancies expanded to form nanometer-sized holes,which then grew along the perimeter and propagated to both the top and bottom layers of a bilayer graphene joined by a bilayer edge.The layer-by-layer peeling was induced by atom sublimation caused by Joule heating and facilitated by atom displacement caused by high-energy electron irradiation,and may be harnessed to control the layer thickness of graphene for device applications.

Sublimation-condensation phenomenon in microwave freeze-drying

A sublimation condensation model is developed for microwave freeze drying of unsaturated porous media. The transport properties in the model are analyzed and the model is calculated numerically for the microwave freeze drying of unsaturated porous media. The results show that the effects of sublimation condensation region on drying processes are significant as compared with the traditional sublimation interface model.

The sensitivity of snowpack sublimation estimates to instrument and measurement uncertainty perturbed in a Monte Carlo framework

The bulk aerodynamic flux equation is often used to estimate snowpack sublimation since it requires meteorological measurements at only one height above the snow surface.However,to date the uncertainty of these estimates and the individual input variables and input parameters uncertainty have not been quantified.We modeled sublimation for three (average snowpack in 2005,deep snowpack in 2011,and shallow snowpack in 2012)different water years (October 1to September 30)at West Glacier Lake watershed within the Glacier Lakes Ecosystem Experiments Site in Wyoming.We performed a Monte Carlo analysis to evaluate the sensitivity of modeled sublimation to uncertainties of the input variables and parameters from the bulk aerodynamic flux equation.Input variable time series were uniformly adjusted by a normally distributed random variable with a standard deviation given as follows:1)the manufacturer's stated instrument accuracy of 0.3℃ for temperature (T),0.3m/s for wind speed (Uz),2%for relative humidity (RH),and 1mb for pressure (P);2)0.0093 m for the aerodynamic roughness length (Zo)based on Zo profiles calculations from multiple heights;and 3)0.08m for measurement height (z).Often z is held constant;here we used a constant z compared to the ground surface,and subsequently altered z to account for the change in snow depth (ds).The most important source of uncertainty was zo,then RH.Accounting for measure- ment height as it changed due to snowpack accumulation ablation was also relevant for deeper snow.Snow surface sublimation uncertainties,from this study,are in the range of 1%to 29% for individual input parameter perturbations.The mean cumulative uncertainty was 41%for the three water years with 55%,37%,and 32%occurring for the wet,average,and low water years.The top three variables (z varying with ds,Zo,and RH)accounted for 74% to 84% of the cumulative sublimation uncertainty.

Ground-based investigations on phase-moving phenomenon with space sublimation cooling for lunar exploration missions

The lunar surface is a typical vacuum environment,and its harsh heat rejection conditions bring great challenges to the thermal control technology of the exploration mission.In addition to the radiator,the sublimator is recommended as one of the promising options for heat rejection.The sublimator makes use of water to freeze and sublimate in a porous medium,rejecting heat to the vacuum environment.The complex heat and mass transfer process involves many physical phenomena such as the freezing and sublimation phase change of water in the porous medium and the movement of the phase-change interface.In this paper,the visualized ground-based experimental approaches of space sublimation cooling were presented to reveal the moving law of threephase point and the growth phenomenon of ice-peak and icicle in microchannels under vacuum conditions.The visualized experiments and results prove that the freezing ice is divided into the porous ice-peak and the transparent icicle.As the sublimation progresses,the phase-change interface moves downward steadily,the length of the ice-peak increases,but the icicle decreases.The visualized experiments of space sublimation cooling in the capillary have guiding significance to reveal the sublimation cooling mechanism of water in the sublimator for lunar exploration missions.

Deposition and characterization of Pd-Ti thin film by sublimation

Introduction Pd/Ti double-layer thin film as non-evaporable getter(NEG)was deposited by sublimation,and its activation temperature was as low as 100℃.The Pd film was deposited in situ after Ti deposition to ensure no oxidization on Ti film.Pumping speed test and characterization method The pumping speed of the coated pipe was measured by a pumping speed test system.The sticking factor was calculated by Molflow.The surface morphology was observed by a scanning electron microscope(SEM).The chemical composition of the film was measured by an energy-dispersive spectrum inbuilt with the SEM.The crystalline structure of the film was measured using grazing incidence X-ray diffraction.Conclusion It was found that the pumping performance of the Pd/Ti film still remained high after 15 times of activation.The maximum pumping speed after heating at 100℃for 24 h was 1.1 L/s cm^(2)and 0.49 L/s cm^(2)for H_(2)and CO,respectively.It can be concluded that the key to reducing the activation temperature of NEG materials is to enhance the oxidation resistance of the surface of NEG.

On the Sublimation of the Demo-cratic Political Thought of Chen Duxiu

Chen Duxiu’S political career might be said to have been awakened by the Sino.Japanese War(1 894—95),and it ended,or rather.underwent a final awakening.in themidst of the Chinese nation’S War of Resistance against Japan.

Simulation of Weather Conditions on Mars

In times of active research of the possibilities of colonization of other planets,it is important to acquire the skills of forecasting weather conditions on the planets,which are the prospects for human settlement.In this research,the theoretical model is developed that describes the physical processes that occur in the atmosphere of Mars in order to calculate the surface temperature of the planet for any point of the planet’s area,time of day,and day of the year.The following theoretical model is implemented in computer software realized by Python programming language to calculate the necessary data.

The ligand coordination approach for improving the stability of low-mercury catalyst in the hydrochlorination of acetylene

Mercuric chloride supported on activated carbon(HgCl_2/AC) is used as an industrial catalyst for the hydrochlorination of acetylene. Loss of HgCl_2 by sublimating from the surface of activated carbon causes the irreversible deactivation of mercury catalyst and environmental pollution. In this work, a ligand coordination approach based on the Principle of Hard and Soft Acids and Bases(HSAB) was employed to design more stable lowmercury catalyst. The low-mercury catalysts(4% HgCl_2 loading) were prepared by using HgCl_2 and potassium halides(KX, X = Cl, I) as precursors. The HgCl_2-4KI/AC catalyst showed best catalytic stability than HgCl_2/AC and HgCl_2-4KCl/AC in the hydrochloriantion of acetylene. HgCl_2 could form more stable complex with KI,K_2HgI_4 as the main active component of the HgCl_2-4KI/AC catalyst. The characterizations of XRD and EDX analysis illustrated that the active component of HgCl_2-4KI/AC was highly dispersed on the surface of activated carbon.The sublimation rates of HgCl_2 from the catalysts verified that the active component with larger stability constant had better thermal stability. Using Hg(Ⅱ) complexes with high stability constant as the active component may be the research direction of developing highly stable low-mercury catalyst for the hydrochlorination of acetylene.

Influence of anode temperature on ignition performance of the IRIT4-2D iodine-fueled radio frequency ion thruster

This paper reports the ignition performance of the iodine-fueled radio frequency(RF)ion thruster(IRIT)at different anode temperaturesT_(a0).The experimental results show that the anode temperature plays important role on the ignition process of the IRIT.There were two characteristic temperatures related to the anode:the minimum ignition temperatureT_(i0)and the stable ignition temperatureT_(is),which were much lower than the pipeline temperature and the storage tank temperature.AtT_(a0)<T_(i0),it failed to discharge.WhenT_(i0)≤T_(a0)<T_(is),it was ignited with dramatical oscillations.AtT_(a0)≥T_(is),the discharge was stable in a large anode temperature range.The analysis showed that the different discharge phenomena at different anode temperatures were attributed to the change of iodine flow rate during the process of the iodine deposition-clogging and sublimation-clearing inside the thruster.The research helps improve the preheating design of the iodine-fueled electric thruster.

Preparation of Al2O3–SiO2 composite aerogels and their Cu2+absorption properties

In order to remediate heavy metal ions from waste water,Al2O3–SiO2 composite aerogels are prepared via a sol–gel and an organic solvent sublimation drying method.Various characterisation techniques have been employed including X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscope(SEM),Energy-dispersion X-ray spectroscopy(EDX),Brunauer–Emmett–Teller(BET)N2 adsoprtion isotherm,and atomic absorption spectrometer(AAS).XRD and FTIR suggest that the aerogels are composed of mainly Al2O3 and minor SiO2.They have a high specific surface area(827.544 m^2/g)and high porosity(86.0%)with a pore diameter of~20 nm.Their microstructures show that the distribution of Al,Si,and O is homogeneous.The aerogels can remove~99%Cu^2+within~40 min and then reach the equilibrium uptake(~69 mg/g).Preliminary calculations show that the Cu2+uptake by the aerogels follows pseudo second-order kinetics where chemical sorption may take effect owing largely to the high surface area,high porosity,and abundant functional groups,such as Al–OH and Si–OH,in the aerogel network.The prepared aerogels may serve as efficient absorbents for Cu^2+removal.

Experimental and analytical assessment of the hypervelocity impact damage of GLAss fiber REinforced aluminum

This article addresses the response of GLAss fiber REinforced aluminum to hypervelocity impacts of micrometeoroid analogs at impact velocities of 7 km/s and beyond.In relation,the damage modes of different GLAss fiber REinforced aluminum configurations have been exemplified.The GLAss fiber REinforced aluminum configurations comprised six to twelve variably thick aluminum layers and up to four plies of glass fiber reinforced epoxy per composite laminate.Hypervelocity impact experiments have been conducted with the help of a two-stage light-gas gun,wherein aluminum-and stainless steel projectiles were launched at velocities up to 7.15 km/s.Visual inspection of the damage area suggested the dissipation of impact energy in elastic-plastic deformation,petalling,delamination,debonding,tensile failure of fibers,and pyrolysis of epoxy.A prevailing damage mode was not apparent albeit.The quasi-isotropic ply orientation of S2-glass/FM94-epoxy laminates promoted the interference of shockand rarefaction waves and suppressed the damage area of GLAss fiber REinforced aluminum.To discriminate between the impact performance of different GLAss fiber REinforced aluminum configurations,the energy dissipated in different damage modes of GLAss fiber REinforced aluminum has been assessed quantitatively.In terms of normalized energy,the cross-ply GLAss fiber REinforced aluminum dissipated higher energy in petal formation than in other primary damage modes.The normalized petalling energy was found to decline with the increase of impact energy.The outcomes of this study will help to optimize the GLAss fiber REinforced aluminum laminate,which will be employed as a bumper shield to prevent the fatal damage and the unzipping of a spacecraft pressure bulkhead.

Estimation of Snowmelt Infiltration into Frozen Ground and Snowmelt Runoff in the Mogot Experimental Watershed in East Siberia

Understanding how spring runoff is generated in East Siberia during the spring thaw is important to predicting river flows. To evaluate the snowmelt runoff generated, a simple runoff model was developed. The model involves processes of water and energy balance within the snowpack and energy balance within soil, snowmelt infiltration into the frozen ground, and surface runoff. The model reproduced inter-seasonal and seasonal variations of snow depth, active layer depth within soil, and snowmelt runoff. Snowmelt infiltration into frozen ground within the upper 20 cm of soil was also reproduced by the model. Thus, we believe the model can simulate snowmelt infiltration and surface runoff in the Mogot experiment watershed. The model suggested that the inter-annual variation in infiltration determined the amount of spring runoff. The amount of infiltration during thaws exceeded the discharge;the range was from 20 to 60 mm and the percentage of infiltration to melt water was 44% to 60%. Therefore, infiltration into the frozen ground strongly determined snowmelt runoff. In addition, ongoing climatic change can increase snowmelt runoff, because of less sublimation loss and snowmelt infiltration into the frozen ground.

Numerical Analysis on Wood Pyrolysis in Pre-Vacuum Chamber

In the previous experimental work, a new technology system for wood pyrolysis was developed to aim at mitigating climate change, global warming, and energy crisis as well as enhancing low electrification in rural areas in developing countries. The new technology system equipped with a pre-vacuum chamber requires low cost and less maintenance. However, large wood pyrolysis in the pre-vacuum chamber is rather complicated. To obtain a good understanding of the previous experimental results, a numerical analysis taking account of heat-mass transfer and chemical reaction is carried out. Two-step general reaction model is proposed for the numerical analysis. The first stage is volatile and char formation from the wood pieces and the second state is decomposition of the volatile to five species including vapor of tar. In this analysis, chemical formulae of the volatile and the tar are successfully identified hypothetically. The results obtained by this numerical analysis can explain the experimental results reasonably and provide useful information about time evolution of volatile formation, temperature change in pre-vacuum chamber with time, and species mole concentration decomposed from the volatile.

从“崇高”与“sublime”侧看我国的近代化

"崇高"是康德《判断力批判》的核心词之一,该词的基本涵义东西方有很大的差异。不同的文化有着各自规范的价值观念,也就意味着,不同文化的不同民族,观察世界的角度和思维方式不同,这种不同导致中西方在"国家的大思维"上有一定差异。

Toward Sublime: the Comparison of Sea Poems in Chinese and English Literature

This essay briefly discusses different reflections of western and Chinese philosophy towards sea in poems.By the comparison of the evaluation of sea in Chinese and English poems,this essay reaches the conclusion that both cultures have sublime understanding towards sea.