6,712 research outputs found
Synthesis and Characterization of Phase Change Material Microcapsules Using Different Emulsifiers
In this study, a series of phase change material microcapsules (MicroPCMs) were synthesized by a core-shell-like emulsion polymerization method using different emulsifiers. The interactions between core material, shell material and dispersed medium were investigated in detail. The copolymer (PS-MAA) of styrene and methylacrylic acid and paraffin were used as wall materials and core materials respectively. High temperature interfacial tensiometer was employed to measure the interactions between different materials. Fourier transformed infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Thermogravimetry (TG), Differential scanning calorimeter (DSC) and laser particle size analyzer were used to characterize the chemical structure, morphology, thermal properties, particles size and size distribution of the MicroPCMs. The results indicated that alkylphenol polyoxyethylene (OP-10) is the optimal emulsifier in this method. The MicroPCMs prepared by using OP-10 as emulsifier displayed smooth and compact surface, the productivity was as high as 93.35%. The melting enthalpy and crystallization enthalpy were -84.6J/g and 83.5J/g, respectively. The mean particle size was 16.33μm
Chebyshev pseudosite matrix product state approach for the spectral functions of electron-phonon coupling systems
The electron-phonon (-ph) coupling system often has a large number of
phonon degrees of freedom, whose spectral functions are numerically difficult
to compute using matrix product state (MPS) formalisms. To solve this problem,
we propose a new and practical method that combines the Chebyshev MPS and the
pseudosite density matrix renormalization group (DMRG) algorithm. The Chebyshev
vector is represented by a pseudosite MPS with global fermion symmetry,
which maps bosonic degrees of freedom onto pseudosites, each
with two states. This approach can handle arbitrary -ph coupling
Hamiltonians where pseudosite DMRG performs efficiently. We use this method to
study the spectral functions of the doped extended Hubbard-Holstein model in a
regime of strong Coulomb repulsion, which has not been studied extensively
before. Key features of the excitation spectra are captured at a modest
computational cost. Our results show that weak extended -ph couplings can
increase the spectral weight of the holon-folding branch at low phonon
frequencies, in agreement with angle-resolved photoemission observations on
one-dimensional (1D) cuprates.Comment: 12 pages, 8 figures, new results adde
Boosting Logical Reasoning in Large Language Models through a New Framework: The Graph of Thought
Recent advancements in large-scale models, such as GPT-4, have showcased
remarkable capabilities in addressing standard queries. However, when facing
complex problems that require multi-step logical reasoning, their accuracy
dramatically decreases. Current research has explored the realm of
\textit{prompting engineering} to bolster the inferential capacities of these
models. Our paper unveils a pioneering prompting technique, dubbed
\textit{Graph of Thoughts (GoT)}. Through testing on a trio of escalating
challenges: the 24-point game, resolution of high-degree polynomial equations,
and derivation of formulas for recursive sequences, our method outperformed
GPT-4, achieving accuracy improvements of , , and for each
respective task. Moreover, when juxtaposed with the state-of-the-art (SOTA)
prompting method, \textit{Tree of Thought (ToT)}, our approach registered an
average accuracy boost of , , and
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