Organic Rankine cycle (ORC) which recovers waste heat in the temperature range of 80°C-140°C was investigated. Exergy efficiencies of various components and ORC system were paid great attention. The working ...
Organic Rankine cycle (ORC) which recovers waste heat in the temperature range of 80°C-140°C was investigated. Exergy efficiencies of various components and ORC system were paid great attention. The working fluids of R245fa and R600a are used. It is found that, for saturated ORCs, the expander inlet temperature has the optimum value, so the system exergy efficiency is maximum. With the increase of heat source temperature, the optimal inlet temperature of the expander is also increased. And also for saturated ORCs, the exergy efficiencies of evaporator and expander are highest efficiency, when evaporator exergy efficiency is increased with increase of heat source temperatures, the expander exergy efficiency is unchanged. The condenser decreased exergy efficiencies by increasing the heat source temperatures.
Particle technology, developed for the production and processing of all kinds of granular materials and powders, has been a pillar for a wide range of industries even in the pre-industrial era, and has experienced rap...
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Particle technology, developed for the production and processing of all kinds of granular materials and powders, has been a pillar for a wide range of industries even in the pre-industrial era, and has experienced rapid expanding and upgrading in recent years together with other modern technologies. It covers not only traditional areas such as mining, fuel and energy, chemical engineering, agriculture and food processing, but also pharmaceutics, cosmetics and nano-materials. In fact, particle technology is dealing with the second largest quantity of materials in all industries, only after water, and approximately 10% of the energy consumption worldwide is related to the processing of particulate materials. In addition, almost half products and 3/4 feed stocks in chemical engineering are in the form of grains or powders.
Deep understanding of the fluorescence quenching mechanisms of probes plays a crucial role in developing their practical *** fluorescence quenching mechanism of hydrazine-based fluorescence probes needs to be clarifie...
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Deep understanding of the fluorescence quenching mechanisms of probes plays a crucial role in developing their practical *** fluorescence quenching mechanism of hydrazine-based fluorescence probes needs to be clarified up to the ***,we designed and synthesized a new hydrazine-based fluorescence probe(HA-Na)based on the naphthalimide *** clarified the molecular origin of the non-fluorescence of this probe with the aid of computational chemistry and spectroscopic *** showed that the significant rotation of the hydrazine group in the excited state potential energy surface,which caused the complete charge separation,was responsible for the fluorescence quenching of the probe in an organic *** the rotation was prevented in an aggregative state or high-viscosity solution,the fluorescence of the probe *** other words,the fluorescence quenching mechanism of hydrazine-based fluorescence probes was attributed to the formation of a twisted intramolecular charge transfer(TICT)*** importantly,we demonstrated that this fluorescence molecular rotor could be used to monitor the autophagy process in living cells by detecting lysosomal viscosity changes during ***,this work provides an essential theoretical basis for the developing potential hydrazine-based fluorescence molecular rotors.
The previous neglect of shale oil multi-component characteristics and the nanpore wall properties of real shale result in an insufficient understanding of shale oil flow mechanisms in nanopores . Meanwhile, research o...
The previous neglect of shale oil multi-component characteristics and the nanpore wall properties of real shale result in an insufficient understanding of shale oil flow mechanisms in nanopores . Meanwhile, research on the flow regimes of shale oil remains lacking. In this study, molecular dynamics simulations are employed to investigate the flow of shale oil in hydroxylated quartz nanopores and rough kerogen nanopores. Simulation results show that the flow regime changed as the pressure gradient (∇ p ) increased to a critical value (∇ p c ). The velocity profile was parabolic when ∇ p < ∇ p c , but gradually became piston-like when ∇ p ≥ ∇ p c . Because increasing ∇ p leads the adsorbed molecules desorbing, aggregating in the pore center, and forming clusters that are not easy to shear. Increasing vertical force from pore wall causes fluid aggregation in the pore center as ∇ p increases. The ∇ p c in kerogen nanopores is larger than that in quartz nanopores due to the rough kerogen surface and sticky layers. Multi-component fluids have higher ∇ p c than single-component fluids in quartz nanopores. However, they have the same ∇ p c in kerogen nanopores due to the rough kerogen surface. This investigation can provide theoretical basis for high-efficient production of shale oil.
ABSTRACTABSTRACTA Ti3C2MXene/Ti composite powder was developed through surface modification and powder coating for producing a high-performance titanium matrix composites (TMCs) by laser power bed fusion. Introducing ...
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ABSTRACTABSTRACTA Ti3C2MXene/Ti composite powder was developed through surface modification and powder coating for producing a high-performance titanium matrix composites (TMCs) by laser power bed fusion. Introducing MXene rarely changed the original sphericity and flowability of Ti powder while it slightly enhanced the laser absorption capacity of Ti powder. The printing conditions in turn affected the morphology and distribution of MXene in as-printed composites. At optimised printing parameters, majority of MXene with high structural integrity and uniform distribution remained along the grain boundaries of as-printed composites, and a combination of high surface quality, geometrical accuracy and densification was obtained. The remaining MXene played the synergy of pulling-out effect and load transfer role, which increased the yield strength from 530 to 710 MPa, while retaining good ductility (elongation of 19.8%). Compared with ASTM standard cast Ti64 alloy, our MXene/Ti composites also exhibited superior comprehensive tensile properties and excellent strength-ductility synergy.
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