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Cemented paste backfill (CPB) has been extensively used in the mine industry to backfill underground mine cavities for ground support and/or tailings management. Once placed in mine underground cav...

In this work, solar-heating-induced temperature-based photocatalytic hydrogen evolution reaction (PC-HER) of different photocatalysts (TiO2 P25, g-C3N4, and their loaded Pt) was comprehensively stu...

Lead zirconate-lanthanum magnesium niobate (Pb(1-x)Laх[Zr(1-x)Mg2х/3Nbх/3]O3) solid solutions with x up to 10 mol.% have been obtained by solid phase synthesis method. It has been found that solid ...

The temperature-dependent structure and properties of a liquid GaInSn eutectic alloy have been investigated by using in situ high-energy X-ray diffraction, thermal expansion, and heat capacity meas...

The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.

Heterointerfaces coupling complex oxides exhibit coexisting functional properties such as magnetism, superconductivity, and ferroelectricity, often absent in their individual constituent. SrTiO3 (STO), a canonical band insulator, is an active constituent of such heterointerfaces. Temperature-, strain-, or mechanical stress-induced ferroelastic transition leads to the formation of narrow domains and domain walls in STO. Such ferroelastic domain walls have been studied using imaging or transport techniques and, often, the findings are influenced by the choice and interaction of the electrodes with STO. In this work, we use graphene as a unique platform to unveil the movement of oxygen vacancies and ferroelastic domain walls near the STO surface by studying the temperature and gate bias dependence of charge transport in graphene. By sweeping the back gate voltage, we observe antihysteresis in graphene typically observed in conventional ferroelectric oxides. Interestingly, we find features in antihysteresis that are related to the movement of domain walls and of oxygen vacancies in STO. We ascertain this by analyzing the time dependence of the graphene square resistance at different temperatures and gate bias. Density functional calculations estimate the surface polarization and formation energies of layer-dependent oxygen vacancies in STO. This corroborates quantitatively with the activation energies determined from the temperature dependence of the graphene square resistance. Introduction of a hexagonal boron nitride (hBN) layer, of varying thicknesses, between graphene and STO leads to a gradual disappearance of the observed features, implying the influence of the domain walls onto the potential landscape in graphene.

The effect of light- and elevated temperature-induced degradation (LeTID) can be nonpermanently reversed by charge carrier injection below the degradation temperature (commonly used degradation temperatures are above ~70 °C). In this study, we show that the rate of temporary recovery depends strongly on the excess carrier density. We observe that the order of the reaction changes from pseudo-zero to first with increasing injection. The rate decreases slightly with increasing temperature. Since the samples can go through multiple degradation/recovery cycles without distinct changes in the degradation kinetics, the experimentally accessible recovered and degraded states are interpreted as manifestations of the equilibrium concentrations of the defect responsible for LeTID at different temperatures. Based on our observations, we argue that the process underlying LeTID degradation is the dissociation of a precursor rather than an association of two or more components. In light of the relation between LeTID susceptibility and bulk hydrogen concentration, we hypothesize that the LeTID precursor dissociates into the LeTID defect and monatomic hydrogen. Numerical simulations of the coupled rate equations including hydrogen interactions well reproduce the experimental observations; according to these results, the presence of a sink for the atomic hydrogen such as dopant atoms is paramount for the LeTID degradation.

Highly accurate high-throughput experimentation (HTE) data for a set of 21 silicon-bridged C2-symmetric ansa-zirconocenes in propene homopolymerization were collected and were used to develop quant...

Adsorption of polycyclic aromatic hydrocarbons (PAHs) on mineral surfaces plays an important role in many engineering fields, such as oil recovery and oil sands production. In this work, the adsorp...

The interaction between bending and shear effects in steel beams can be amplified under fire conditions due to rapid degradation in strength and stiffness properties of steel, together with temperature-induced local instability effects. This paper presents temperature-induced moment-shear (M-V) interaction phenomenon in compact (Class 1) steel beams. Results generated from numerical studies are utilized to quantify the effects of temperature-induced critical parameters influencing moment-shear interaction, shear and flexural sectional capacity, as well as instability in steel beams under fire conditions. The major findings of this work are two folds: (1) occurrence of temperature-induced instability adversely reduces shear capacity, as compared to flexural capacity, and (2) this rapid degradation in shear capacity trigger moment–shear interaction phenomenon at elevated temperatures. Eventually, this shifts failure mode in steel beams towards a shear dominant failure mechanism on the interaction envelope.

We present a detailed case study of degradation in monocrystalline silicon photovoltaic modules operating in a utility-scale power plant over the course of approximately three years. We present the results of degradation analysis on arrays within the site, and find that five of the six arrays degraded faster than the best performing array, even though the arrays consist of modules of the same manufacturer and model. We also describe the results of extensive laboratory characterization of modules returned from the field, including module- and cell-level current–voltage characterization, luminescence imaging, and accelerated testing. The laboratory test results and the field performance are consistent with light and elevated temperature induced degradation (LeTID). Notably, we observe differences in back contact technology between affected and unaffected modules. This article also demonstrates a method to identify possible LeTID degradation in the field and confirm the result with laboratory testing of a small number of modules.

We have studied lifetime instabilities in p -type boron-doped mono-like silicon during light soaking (LS) and dark annealing (DA) at different temperatures, and their behavior upon LS/DA cycling at various degradation and regeneration stages. Despite having similar capture cross section ratios, it is found that the defects responsible for the degradation under illumination and in the dark could stem from two separate reactions, with hydrogen being the common precursor. A model for light and elevated temperature induced degradation (LeTID) is presented based on our experimental findings. It is proposed that hydrogen atoms originally bound in the silicon nitride layer are released into the silicon bulk above a certain firing temperature, which then interact with some other species in the silicon bulk under illumination, causing the LeTID degradation. During the cooling ramp of the firing process or extended DA, hydrogen in the silicon bulk starts to effuse into the ambient, reducing the amount of hydrogen remaining in the silicon bulk, and correspondingly affecting their LeTID behavior. The proposed model provides new insights to help understand complex LeTID behaviors reported in the literature, including its dependence on the firing profile, sample thickness, dopant type, and DA pretreatment.

The precise structure of nanocrystal (NC) solids is a delicate balance between energetic and entropic interactions. Studying the temperature-dependent structure of NC solids can inform understandin...

In this study, the effects of the single and multiple productions of samples by additive manufacturing on residual stress and displacement (distortions) were investigated. The samples were manufactured by Selective Laser Melting (SLM) machine using Ti6Al4V powders. Each time a different number (1, 5 and 13 samples) of cubic shaped samples were produced on the building platform. During the process, samples were observed with a thermal camera first, in order to understand the relationship amongst the residual stress, displacement and temperature gradients. Then, displacement values were measured experimentally with Coordinate Measurement Machine (CMM) device. Next, both displacement and residual stresses were calculated via Finite Element Analysis (FEA) method. Finally, residual stresses and displacement equations were determined by genetic expressional programming (GEP) using the results and data obtained from the tests and FEA. According to the results, the regression values of residual stress and displacement equation were found to be 0.96% and 0.88%, respectively. As the number of manufactured samples on the same platform increased, temperatures and irregular temperature distribution were increased.

The thermal lens problem of optical system caused by high temperature environment is a common problem. Athermal design of lenses based on optical calculation software is an effective passive compensation method. But it is difficult to determine its accuracy and measure it experimentally. We describe an athermal design technology and propose a simulated scheme to verify the accuracy of this design. Three materials with negative dn/dT have been selected to compensate for the thermal lenses produced by a fused silica lens. The results show that the compensation effect of N-PSK53A is the best.

It is widely realized in the metal forming industry that the processes suffer from start-up effects, which can cause products that fall out of their specification limits after a certain period of running. Attempts are made to solve this by modelling the underlying tribological phenomena in order to design robust processes. Another possibility is to adapt the processes to changes of the tribological system through control systems. For both approaches the ability to account for tribological effects in numerical simulations is a crucial requirement. To showcase this, a real-life demonstrator process is built, that is specifically designed to be sensitive to temperature induced frictional effects. This enables the validation of the physical based tribological models on an industrial scale, without the need to add complexity from other research domains in the field of metal forming. After designing the tooling, the process’ sensitivity to temperature induced frictional effects is verified by implementing and applying all simulations tools created [1]. The industrial scale demonstrator process is ran, while measuring tool temperature and geometrical product parameters (quality features) in real-time, at different stroke rates until a steady-state temperature is reached. The recorded data sets, combined with the products themselves, show during the full validation that the predictions from the simulations are generally in good agreement with the results from production.

Specimens for transmission electron microscopic (TEM) investigations were prepared from γ titanium aluminide alloys with Gallium and Argon ions using a focused ion beam (FIB) and a precision ion polishing system (PIPS). Preparation to electron transparency by Gallium ions alone leads to the formation of crystalline platelets of the α titanium phase at the specimen surfaces, revealed through conventional and high resolution (HR) TEM analysis. The platelets are assumed to precipitate from priorly formed amorphous layers. The required crystallisation temperature of about 480°C is generated through the ion bombardment implying that the γ titanium aluminides can be heated substantively during sputtering. The primary reason for this is the restricted transfer of heat away from the beam impact point when the specimen thickness comes close to the beam diameter. The formation of the platelets can be avoided by terminating the Gallium ion treatment prior to that, while providing for a sufficient thermal bonding of the specimen to the grid as well and polishing off the remaining material by Argon ions, which are much less focused and less energetic, so that the local heat peaks are reduced.

A mechanism to explain the lower onset strengthening temperature induced by CaCO$_3$ in alumina-based macroporous ceramics is proposed, which relies on hydrocalumite-like phase formation during processing. Close to 600$^\circ$C, such phases are decomposed to lime and mayenite (12CaO$\cdot$7Al$_2$O$_3$), where the latter, due to its intrinsic nanoporosity and high thermal reactivity, generates bonds between the ceramic particles at ~700$^\circ$C, resulting in microstructure strengthening. Based on this premise, the authors concluded that other Ca$^{2+}$ sources could act similarly. Indeed, compositions containing Ca(OH)$_2$ or CaO showed the same effect on the onset strengthening temperature, which reinforces the proposed mechanism. The results attained indicated that macroporous insulators could be thermally treated at lower temperatures, just to acquire enough mechanical strength for installation, finishing in situ their firing process. Besides that, lower sintering temperatures could be used to produce macroporous ceramics that would be applied in low thermal demand environments, e.g. aluminum industries.

Hybrid organic-inorganic FAPbX3 perovskites (FA = NH2CHNH2+, X = Cl-, Br-, I-) are currently intensively investigated in solar cells. In this study, off-resonance Raman and far-IR absorption spectr...

We report a highly stable Zn metal anode by simply controlling the operating temperature at 0 °C. Without any further protection, the Zn anode exhibits an ultra-long cycle life over 2500 h (>100 days) in Zn symmetric cells with 3 M Zn(CF3SO3)2 aqueous electrolyte. This impressive performance is ascribed to the improved Zn metal corrosion resistance and compact and smooth Zn surface morphology during Zn plating/stripping at low temperatures.

The evolution rule of temperature-induced deflection in main girders is an important index to evaluate the service performance of long-span cable-stayed bridges, which directly reflects th...

Thermoresponsive interpenetrating networks (IPNs) were prepared by sequential synthesis of a biohybrid network of star-shaped poly(ethylene glycol) [starPEG] and heparin and a poly(N-isopropylacryl...

Nanocomposite thin film containing Au nanoparticles in carbon matrix is developed using co-sputtering method in a high vacuum chamber (

Optical lenses used in high temperature environment are usually affected by thermal lenses problems, but it is difficult to evaluate their focal shifts in practical applications. A three-dimensional single-lens model based on finite element solver was built to evaluate the focal shift in this study, when the temperature of surface was raised from the initial temperature to the specified temperature. An experimental method based on a Hartmann-Shack wavefront sensor was proposed to verify the rationality of the model. The nearly same results between simulations and experiments for N-BK7 and fused silica were obtained, which proves that it is feasible to analyze focal shifts of optical lenses by simulation methods.

We provide experimental evidence that photoalignment at the nematic liquid crystal (NLC)-polymer interface cannot be simply considered as a two-dimensional process. Moreover, our experiments clearly indicate that the photoaligning process does not depend on the individual properties of the NLC material and those of the interfacing polymer exclusively. The polymer and the NLC layer interact, i.e., the polymer-liquid crystal interface should be regarded as a coupled system, where the two components mutually influence each other. Furthermore, we show that the temperature induced anchoring transition also has to be taken into account for the complete description of the photoalignment mechanism.

Two techniques for the nucleation and growth of single crystals of biological macromolecules are proposed. The first one utilizes a very slow temperature shift at a capillary point where the crystal is to be grown. This allows to suppress an undesirable multiple nucleation. The second technique includes several local rapid temperature changes (a temperature “shock”) forcing the nucleation at the given point. These techniques were successfully tested while growing single crystals of lysozyme and xylanase respectively.

Three different stir tools with the pin eccentricity of 0, 0.4 and 0.8 mm were applied to the friction stir processing (FSP) of Al-6061 alloy. Results show that the pin-affected zone (PAZ) enlarges and the grain size in the stir zone (SZ) decreases as the pin eccentricity increases. Moreover, the low peak FSP temperature induced by the pin eccentricity gives rise to the coarsening of strengthening precipitates in the SZ. Compared with the pin-eccentric FSP samples, the SZ produced without pin eccentricity exhibits the highest hardness and yield strength due to the high amount of fine precipitates. However, the application of pin eccentricity elevates the overall tensile properties of FSP samples through changing the failure location from heat-affected zone (HAZ) to SZ.

Owing to its thermal conductivity property, the strength of structural steel is highly susceptible to elevated temperature. When steel is used in main load-bearing members in buildings that are vulnerable to fire, great attention should be paid to the effect of the elevated temperature on the residual strength of those members. Hence, the design criteria of such members must incorporate temperature in their requirements. Current standards and codes of practice for steel structures have attempted to address the elevated temperature in their design procedures. However, the design procedures suggested by these standards and codes still lack accuracy and rationality compared to experimental results, especially at high values of elevated temperature. The main objective of the present study is to suggest a new and accurate analytical method to reasonably predict the residual axial and lateral strength of steel beam columns when subjected to elevated temperature. The suggested method uses a newly derived moment-curvature equation of steel beam columns at elevated temperature. The effect of elevated temperature on the material and mechanical characteristics of the steel was accounted for by utilizing reduction factors suggested by Eurocode 3 (EC3). Validation of the suggested method against experimental and numerical simulation results has demonstrated that the developed method can reasonably predict the residual axial and lateral resistance of steel beam-columns at high values of elevated temperature. The suggested method has many significant applications in the design of steel members at elevated temperature induced by fire.

The heat capacity Cp is calculated from the temperature-induced and pressure-induced Raman frequency shifts by means of the mode Gruneisen parameter for the I-II transition of solid benzene, naphthalene and anthracene. For this calculation, contributions to Cp are considered due to the six lattice modes of solid benzene, six librational modes of naphthalene and, six phonons and nine vibrons of anthracene with their mode Gruneisen parameters at various temperature (P=0) and pressures (T=300 K). Our calculated Cp explains the observed behavior of the I–II transition in solid benzene and also of naphthalene and anthracene. Temperature dependence of the entropy difference is calculated from the heat capacity for those hydrocarbons, which can be compared with the observed data. Our results indicate that the heat capacity Cp can be calculated as functions of temperature and pressure from the spectroscopic parameters, in particular, the Raman frequency shifts as we have studied here for hydrocarbons.

The pressure-dependent electronic properties of polycrystalline β-Ag0.33V2O5 were investigated and a discontinuous change of electrical resistance is found at around 4.5 GPa, where semiconductive-like decreasing trend before 4.5 GPa and a metallic-like increasing trend after 4.5 GPa with increasing temperature was observed. Furthermore, high temperature/pressure treatment can markedly reduce the semiconductor-metal (S-M) transition pressure to around 1.5 GPa. The results indicate a promising way for engineering the electronic properties of polycrystalline Ag0.33V2O5, and this pressure/temperature induced semiconductor-metal switch may have potential applications in electronics field.

Ceiling gas temperature is one of the most important factors for heat detection and alarm once an undesirable fire along with releasing hot and toxic smoke is erupted in a building. The impinging flame characterized by the unburnt fuel burning along the ceiling has received much attention in recent years as it poses a greater threat to the ceiling structure, devices and trapped people than the non-impinging flame. Many studies have been focused on the ceiling gas temperature induced by a single flame, while little effort has been put with respect to the multiple flames. The interaction between multiple flames might lead to flames tilt to each other and even merge together with small spacings, resulting in different ceiling gas temperature distribution from the single flame. The aim of this experimental work is to investigate the ceiling gas temperature decay profile induced by two impinging flames. Propane was used as the fuel. The heat release rate (HRR), burner edge spacing and ceiling height above the fuel were overall changed. The ceiling gas temperatures along the direction of changing spacing were measured to determine the impingement point position and temperature decay profile. The results showed that the impingement point position is dependent on the HRR and the spacing as well as the ceiling height, while the maximum gas temperature is weakly affected by the spacing. The established correlation reveals that the maximum excess temperature increases first and then maintains unchanged with increasing the HRR normalized by the ceiling height. The plume radius proposed for the single impinging flame is not enough to characterize the ceiling gas temperature of two impinging flames. A new correlation for temperature decay profile induced by two impinging flames is therefore proposed and validated using the experimental results.

Recently, responsive slippery surfaces with controllable liquid droplet sliding have attracted interest due to their promise for applications in liquid transportation, microfluidics, microreactors, biomedicine and beyond. Controllable liquid sliding is closely related to regulatable interfacial interactions. However, investigations on the interfacial interactions that occur as a droplet slides on a responsive slippery surface are lacking. Herein, we directly detect the interfacial friction forces and adhesion forces between a liquid droplet and a temperature-responsive slippery surface by using atomic force microscopy and analyze the changes of intermolecular hydrogen bonds between droplet and lubricant by using molecular dynamics simulation. The results show that (i) the liquid sliding behavior on the slippery surface can be smartly controlled by increasing/decreasing the temperature; (ii) the interfacial friction forces and adhesion forces reversibly switch at high and low temperatures, which is the reason for controllable liquid sliding; and (iii) the nature of the switchable interfacial forces and controllable liquid sliding on the temperature-responsive slippery surface is attributed to changes in intermolecular interactions. This work would provide a way to understand the nature of controllable liquid motion on smart-responsive slippery surfaces in terms of intermolecular interactions between a droplet and the surface.

Light- and elevated-temperature-induced degradation (LeTID) in p-type multicrystalline silicon has a severe impact on the effective minority carrier lifetime of silicon and remains a crucial challenge for solar cell manufacturers. The precise cause of the degradation is yet to be confirmed; however, several approaches have been presented to reduce the extent of degradation. This paper presents insights on the impact of thermal budgets and cooling rates during post-firing illuminated anneals and their role in changing the lifetime and mitigating LeTID for thermal processes between 350 and 500 °C. We demonstrate that the thermal budget of these processes plays a crucial role in LeTID suppression and that the cooling rate only plays a role during short treatment durations (≤1 min). For the parameter space studied, we show that annealing for an appropriate time and temperature can both enhance the minority carrier lifetime and completely suppress the LeTID, with the injection-dependent Shockley–Read–Hall lifetime analysis indicating that the recombination activity of the LeTID defects in the bulk has been eliminated. Finally, this paper demonstrates a process that results in a stable lifetime after 800 h of conventional light-soaking at 75 °C.

We performed an extensive study of light induced degradation experiments in PERC solar cells made of Boron doped Cz Silicon material from several experimental crystals. Strong LeTID (Light and Elevated Temperature Induced Degradation) amplitudes were found in cells originating from the top and tail part of the crystals. A statistical analysis reveals a strong correlation to the bulk concentration of Aluminium in cells originating from wafers close to the tail. Close to the top, the LeTID effect is strongly enhanced whenever Oxygen precipitation occurs in the cell process.

© 2019 Elsevier GmbHAdditive manufacturing (AM) has been becoming more widespread and its usage area has been increasing in various industries. However, the mechanical and microstructural properties of the metal parts fabricated by additive manufacturing requires further investigation. In this study, various heat treatment temperature were applied to Inconel 718 specimens fabricated by selective laser melting (SLM) to examine their effects on microstructure, microhardness and wear behavior of the specimens. Moreover, the microhardness and wear response of specimens fabricated by SLM were compared with the wrought Inconel 718. The results provide strong evidence that heat treatment temperature is capable of altering microstructural aspects of as-built specimens. This study also shows microhardness and wear resistance is remarkably induced from the final state of microstructure. Comparative study also provides evidence that Inconel 718 specimen fabricated by SLM can have much higher wear resistance than conventionally produced Inconel 718 if it is heat-treated at certain temperature.

Carbonate rocks have a widespread diffusion in the Earth crust and are extensively used in cultural heritage and buildings. These rocks can be naturally or anthropically exposed to high temperatures. Consequently, relating physical properties to temperature-induced damage is extremely important. Six sets of compositionally and texturally different carbonate rocks, spanning from limestones and marbles to dolomitic marbles, were analysed in this study. Different physical properties, such as porosity, seismic wave velocities and electrical resistivity, were measured before and after thermal treatments with heating/cooling ranges between 105 and 600°C. Microstructural observations and optical analyses were used to investigate how temperature-induced damage affects the physical measured properties of the different microstructures. This integrated approach allowed to define a generalised relationship between physical properties and thermal-induced damage, by way of an induced damage index valid for a broad suite of carbonate rocks.

Temperature-dependent atomic structural evolutions of liquid ${\mathrm{Ag}}_{60}{\mathrm{Ga}}_{40}$ and ${\mathrm{Ag}}_{70}{\mathrm{Ga}}_{30}$ alloys have been studied by in situ high-energy x-ray-diffraction (HEXRD) experiments combined with ab initio molecular-dynamics simulations. The experimental data show a reversible structural crossover at about $1050\ensuremath{\sim}1100 (\ifmmode\pm\else\textpm\fi{}50)\phantom{\rule{4pt}{0ex}}\mathrm{K}$ in both liquid ${\mathrm{Ag}}_{60}{\mathrm{Ga}}_{40}$ and ${\mathrm{Ag}}_{70}{\mathrm{Ga}}_{30}$ alloys. Obvious changes of the electrical resistivity, absolute thermoelectric power, and atomic diffusivity around the similar temperature range for both Ag-Ga liquids strongly support the HEXRD results. The origin of the liquid-to-liquid crossover in both Ag-Ga liquids was suggested to link with the rearrangements of Ag and Ga atoms, i.e., Ag and Ga atoms prefer to associate with themselves in the higher temperature range above 1100 K, consistent with the accelerated increase of the strong covalently bonded Ga--Ga dimers in both Ag-Ga liquids. In addition, more studies from the energy aspect are still desirable to understand the rearrangements of Ag and Ga atoms in the higher temperature range in both Ag-Ga liquids.

The $p\text{\ensuremath{-}}T$ conditions of the solid-solid phase transition from the wurtzite to rocksalt structure in GaN are determined both experimentally and by ab initio calculations. Experimental evaluation was based on the x-ray absorption measurements in a laser-heated diamond anvil cell. At 300 K, the transition was observed near 47 GPa. At lower pressures, the wurtzite to rocksalt transition has been induced by high temperature: 1420 K at 42 GPa and about 2100 K at 37 GPa. Thus the slope of the wurtzite-rocksalt borderline could be evaluated as negative and nonlinear. On the part of the theory, the $p\text{\ensuremath{-}}T$ borderline was determined from a comparative analysis of the temperature dependences of the Gibbs potential of the wurtzite and rocksalt structures for different pressure. The Gibbs potentials were calculated within the quasiharmonic approximation and the self-consistent phonon approach. The results obtained with the self-consistent phonon approach show that the inclusion of the anharmonic phonon effects is indispensable to obtain a very good agreement with the experimental data. Possible consequences of the observed anharmonicity for the still unknown melting behavior of GaN are discussed. In particular, it is suggested that the melting temperature of the rocksalt-GaN, at pressure around 37 GPa, is not much higher than 2100 K.

Through decades of operation, deformation fluctuation becomes a central problem affecting the normal operating of concrete truss combination arch bridge. In order to clarify the mechanism of temperature-induced deformation and its impact on structural stress distribution, this article reports on the temperature distribution and its effect on the deformation of concrete truss combination arch bridge based on bridge health monitoring on a proto bridge with 138 m main span. The temperature distribution and deformation characteristics of the bridge structure in deep valley area are studied. Both of the daily and yearly temperature variation and structural deformation are studied based on bridge health monitoring. Using the outcome of monitoring data, three-dimensional solid finite element models are established to analyze the mechanism of temperature-induced deformation of the whole bridge under different temperature fields. The influence of temperature-induced effect is discussed on local damage based on the damage observation of the background bridge. The outcome of comparisons with field observation validates the analysis results. The relevant monitoring and simulation result can be referenced for the design and evaluation of similar bridges.

Temperature dependence of the band structure, as well as the spin-polarization on the topologically trivial insulator ${\mathrm{TlBiS}}_{2}$ and nontrivial insulator $\mathrm{Tl}\mathrm{Bi}{\mathrm{Se}}_{2}$, have been investigated by spin- and angle-resolved photoelectron spectroscopy. Despite the recent theoretical prediction [Phys. Rev. Lett. 117, 246401 (2016).], topological phase transition (trivial to nontrivial for ${\mathrm{TlBiS}}_{2}$, nontrivial to trivial for $\mathrm{Tl}\mathrm{Bi}{\mathrm{Se}}_{2}$) does not occur in the observed temperature ranges (from 50 to 400 K for ${\mathrm{TlBiS}}_{2}$, from 50 to 475 K for $\mathrm{Tl}\mathrm{Bi}{\mathrm{Se}}_{2}$). Our results indicate that the discrepancy between the theory and the experiment can be understood by considering the overestimation of lattice parameters and the effect of lattice expansion that is neglected in the previous theory. Although some spin-polarized states are observed in ${\mathrm{TlBiS}}_{2}$, it is probably due to the Rashba-like surface (resonant) states and not the topological surface states. On the other hand, the topological surface states in $\mathrm{Tl}\mathrm{Bi}{\mathrm{Se}}_{2}$ is very robust even at 400 K and the spin-polarized states can be used for the real spintronic devices in the large temperature range.

Hydraulic fracturing is an important method to improve the oil and gas production in low and ultra-low permeability reservoirs. A remarkable progress has been made in the technology and materials. However, the existing conventional hydraulic fracturing technology faces problems, such as reservoir damage, equipment abrasion, low effective propped area, and early screen-out. Therefore, a novel self-propped fracturing fluid (SPFF) was proposed, which remains in the liquid-phase before entering the fracture, and forms solid proppant particles when stimulated by the reservoir temperature after entering the fracture (Chemical proppant, CP). In this paper, the micro-morphology of CP was studied by SEM, and the temperature of the CP-formed was measured by the CP formation experiments at room temperature and field conditions. Furthermore, the compressive strength, thermal stability, stability in formation fluid, acid and alkali, leak-off, core damage, and fracture conductivity of the developed SPFF were tested. The test results show that the leak-off volume and core damage level of SPFF were less than that of conventional fracturing fluid, thereby effectively reducing the damage to the reservoir permeability. The CP exhibited good performance in terms of compressive strength, thermal stability, stability in reservoir fluid and treatment fluid. Besides, the conductivity of the propped fracture was high. These advantages determine that CP can meet the field treatment requirements. The CP could enter any narrow fractures, and effectively solved the existing problems in the conventional fracturing technology by significantly improving the fracturing effect, especially the network fracturing effect in tight reservoir systems.

Complex aqueous emulsions represent a promising material platform for the encapsulation of cells, pharmaceuticals, or nutrients, for the fabrication of structured particles, as well as for mimicking the barrier-free compartmentalization of biomolecules found in living cells. Herein, we report a novel, simple, and scalable method of creating multicomponent aqueous droplets with highly uniform internal droplet morphologies that can be controllably altered after emulsification by making use of a thermal phase separation approach. Specifically, temperature-induced phase separation inside as-formed emulsion droplets comprising aqueous mixtures of two or more hydrophilic polymers allows for the generation of Janus and Cerberus emulsion droplets with adjustable internal morphologies that are solely controlled by a balance of interfacial tensions. We demonstrate our approach by applying both, microfluidic and scalable batch production, and present a detailed model study with predictive capabilities that enables fine-tuning and dynamically altering the droplet morphology as a function of types, molecular weights, and hydrophilicities of the polymers as well as the surfactant hydrophilic-lipophilic balance. The ability to rationally design complex aqueous emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new responsive soft materials with implications for a variety of applications beyond encapsulation, including the design of complex adaptive and self-regulating materials, e.g. for chemical and biological sensing applications.

Temperature is well known to affect the aggregation behavior of colloidal suspensions. This paper elucidates the temperature dependence of the rheology of portlandite (calcium hydroxide: Ca(OH)2) s...

The danger of high-strength steel wire (HSSW) under high temperatures is twofold. One is the significant degradation of the material properties of high-strength steel (HSS), which has been ...

Monitoring the light and elevated temperature induced degradation (LeTID) of crystalline silicon solar cells is becoming a standard quality control point in manufacturing. The conventional method light soaking shows several drawbacks, such as the slow response, the large footprint, and low throughput, which limit the LeTID test sampling rate, especially in GW scale mass production. Besides light soaking, LeTID can be induced by applying forward bias upon the P-N junction, which is the current injection. Here, we prove that the current injection can induce the same level of LeTID as light soaking does. In this way, a wide range of current induced degradation (CID) conditions are established on a commercialized equipment. Regarding to the multi crystalline PERC solar cells, 3.5 A-105 °C (for 157 mm cells) is chosen as an accelerated condition to induce LeTID, which is supported by simulations and experimental data.

In this study we describe the green synthesis of temperature-switchable polymer-magnetite nanoparticles (PMNPs) in water at room temperature via an improved co-precipitation pathway. The temperature responsiveness was achieved through the surface modification with a vinyl-based dual-stimuli-responsive block copolymer. Furthermore, these PMNPs enable the investigation of temperature-induced magnetic superstructures and their medical application. published

The friction-type bolted joint transfers the internal forces in the structural members by interface friction, but noticeable seasonal temperature and bolt fracture cause the redistribution of interface friction and threaten the joint safety. Therefore, this study carried out finite element analysis on the interface friction considering the influence of seasonal temperature and bolt fracture. Through finite element analysis, the simulation of interface friction under seasonal temperature revealed the distribution of temperature induced interface friction in different areas and locations. Further simulation of fractured bolts revealed the influence of quantity and location of fractured bolts on the redistribution of interface friction. Finally, the interface frictions in the bolted joint were evaluated using limit state equations. The results showed that: 1) the quantity and location of fractured bolts cause obvious redistribution of interface friction in the bolt-fractured areas; 2) the quantity and location of fractured bolts have slight effect on the total interface friction in the whole splice plate; 3) the reduced interface friction in the bolt-fractured areas was transferred to the areas without bolt fracture, producing little change in the total interface friction; 4) all the splice plates had abundant safety margin after analysis of their limit state equations.

For the friction-type high-strength bolted joint, the bolt fracture can cause redistribution of interface friction, which will seriously endanger the connection safety of structural members. However, current study scarcely focuses on the redistribution of interface friction after bolt fracture. Therefore, this paper will specifically carry out finite element analysis on the redistribution of interface friction caused by fractured bolts. Firstly, the refined finite element model of friction-type high-strength bolted joint is used to investigate the variation of interface friction with uniform temperature and the distribution of interface friction in different areas. Furthermore, stochastic finite element method is introduced to explain how the quantity and location of fractured bolts influence the redistribution of interface friction. Finally, the mathematical model of friction redistribution is built to describe the redistribution of temperature-induced interface friction in the friction-type high-strength bolted joint after bolt fracture. After validation, the mathematical model can well describe the redistribution of interface friction caused by fractured bolts.

The long-term stability of a given concentration of detected gas in laser spectroscopy is always difficult to achieve. We propose that the optical fringe shift caused by temperature-induced cavity length change is the most important factor that limits long-term stability. A wide range of temperature variation causes a large fluctuation in the detected concentration for a long period, and cavities made of a low-temperature expansion material can effectively inhibit the effects of a large temperature variation and improve the minimum detection limit.