Applications of the IAPWS-95 formulation in fluid inclusion and mineral-fluid phase equilibria

The IAPWS-95 formulation explicit in Helmholtz free energy proposed by Wagner and Pruβ （2002） is the best equation of state of water, from which all thermodynamic properties can be obtained over a wide T-p range from 273.16 to 1273 K and from 0 to 1000 MPa with experimental accuracy. This paper reports the applications of the IAPWS-95 formulation in fluid inclusion and mineral-water phase equilibria. A reliable and highly efficient calculation method is presented for the saturated properties of water so that the formulation can be conveniently applied in the study of fluid inclusion, such as calculating homogenization pressures, homogenization densities （or molar volumes）, volume fractions and isochores. Meanwhile, the uni- variant curves of some mineral-dehydration reactions are calculated based on the IAPWS-95 formulation. The computer code of the IAPWS-95 formulation can be obtained from the corresponding author.

Physical and Mechanical Properties of Catalpa bungei Clones and Estimation of the Properties by Near-Infrared Spectroscopy

Air-dry density,modulus of rupture(MOR),modulus of elasticity(MOE),compressive strength parallel to grain,and hardness of Catalpa bungei clones were investigated in this study with feasibility of predicting these properties by near infrared(NIR)spectroscopy.The best candidate Luoqiu 3'has been selected from three clones based on wood physical and mechanical property indices.Lower values of wood physical and mechanical properties have been found in the corewood compared to the outerwood.There were significant positive correlations between the air-dry density and mechanical properties.Information from Cross section for air dry density,compressive strength parallel to grain,and hardness yielded prediction models with better effects,along with the best MOR and MOE modeling effects resulted from average sections'spectra collection.Multiplicative scatter correction(MSC)+Savitzky-Golay(S-G)smoothing method has been proved to be the most applicable way.In addition,the predictions from five point sampling method were slightly better than three point one.Overall,results suggest NIR spectroscopy was viable to predict the physical and mechanical properties of C bungei dones with methods developed in this study proved effective in preliminary screening.

Enhanced intermolecular interactions to improve twisted polymer photovoltaic performance

In polymer solar cells(PSCs), twisted polymer donors usually have low photovoltaic efficiencies due to their poor photoactive layer morphologies. Herein, we successfully improved twisted polymer(PBDT-3T) photovoltaic efficiency by employing C=O groups(PBDT-3TCO) to enhance intermolecular interactions. The maximum power conversion efficiency(PCE) of PBDT-3T is only 1.05%, while the PCE of PBDT-3TCO reaches 11.77% in non-fullerene(NF) PSCs. Both polymers-based PSCs show very similar open-circuit voltages but remarkable differences in their short-circuit currents and fill factors. The single crystals of both functionalized terthiophenes with methyl substituents demonstrate that the terthiophene with C=O units changes molecular pattern by forming intra/inter molecular S???O and O???H interactions but its molecular planarity does not significantly improve.Our comparative studies show that PBDT-3TCO with C=O units possesses a strong aggregation property and optimal photoactive layer morphology in NF PSCs. This study provides important insight into the design of high-performance twisted polymer donors for NF PSCs.