Search

The thermophysical properties and elemental abundances of the noble gases in terrestrial materials can provide unique insights into the Earth's evolution and mantle dynamics. Here, we perform extensive ab initio molecular dynamics simulations to determine the melting temperature and sound velocity of neon up to 370 GPa and 7500 K to constrain its physical state and storage capacity, together with to reveal its implications for the deep interior of the Earth. It is found that solid neon can exist stably under the lower mantle and inner core conditions, and the abnormal melting of neon is not observed under the entire temperature (T) and pressure (P) region inside the Earth owing to its peculiar electronic structure, which is substantially distinct from other heavier noble gases. An inspection of the reduction for sound velocity along the Earth's geotherm evidences that neon can be used as a light element to account for the low-velocity anomaly and density deficit in the deep Earth. A comparison of the pair distribution functions and mean square displacements of MgSiO3–Ne and Fe–Ne alloys further reveals that MgSiO3 has a larger neon storage capacity than the liquid iron under the deep Earth condition, indicating that the lower mantle may be a natural deep noble gas storage reservoir. Our results provide valuable information for studying the fundamental behavior and phase transition of neon in a higher T–P regime, and further enhance our understanding for the interior structure and evolution processes inside the Earth. [ABSTRACT FROM AUTHOR]

Objective was to evaluate the cost-effectiveness of SoHAIC versus sorafenib for the treatment of HCC-Vp3-4, taking into account the viewpoint of Chinese healthcare payers. Methods: This pharmacoeconomic study employed a Markov model to assess the cost-effectiveness of treating HCC-Vp3-4 with SoHAIC in comparison to sorafenib. The patient characteristics were drawn from individuals from the trial conducted between June 2017 and November 2019, with cost and health value data sourced from published literature. The primary outcome measure in this research was the incremental cost-effectiveness ratio (ICER), which indicates the additional cost per quality-adjusted life year (QALY). The willingness-to-pay (WTP) threshold per QALY was set at $30,492.00. Furthermore, 1-way sensitivity and probabilistic sensitivity analyses were carried out to validate the consistency of the results. Results: In the baseline scenario, sorafenib resulted in 0.42 QALY at a cost of $10,507.89, while SoHAIC generated 1.66 QALY at a cost of $32,971.56. When comparing SoHAIC to sorafenib, the ICER was $18,237.20 per QALY, which was below the WTP threshold per QALY. Furthermore, the 1-way sensitivity analysis demonstrated that the ICER remained within the WTP threshold despite fluctuations in variables. In the probabilistic sensitivity analysis, SoHAIC had a 98.8% probability of being cost-effective at the WTP threshold, considering a wide range of parameters. Conclusion: In this cost-effectiveness evaluation, SoHAIC demonstrated cost-effectiveness over sorafenib for HCC with major portal vein tumor thrombosis, as observed from the perspective of a Chinese payer. [ABSTRACT FROM AUTHOR]

The hydrogeochemical characterisics are studied by sampling geothermal hot springs/geothermal wells in eastern Shandong of the Zhangbo fault zone, measuring the main elements and hydrogen and oxygen isotopes of water samples. The results show that: 1 The main chemical types of hot spring water are Ca-HCO3, Na-Cl, Na-HCO3, Na-SO4. 2 The measured values of δD and δ18O are --39. 90% ~ -68. 00% and - 5. 00%~ - 8. 50%, which fell near the meteoric water line in China and the meteoric water line in eastern China, indicating that the hot springs was meteoric water. According to the calculation, the minimum circulation depth in the study area of hot springs is 1183 m, the maximum circulation depth is 4 271 m, and the general variation range of recharge elevaton is 430. 0 --1 366. 6 m.3 The variation range of γNa/ γCi in Shandong region is 0. 509 -- 38. 37, among which, the metamorphism coefficient of Linqulan Cuihu and Cishan hot spring are relatively high, that indicate that it is affected by mineral leaching. 4 The Na-K-Mg triangle diagram shows that most of the hot springs water samples are partially mature water, only the Yuquan hot spring in Gaoqing County bring equilibrium water. [ABSTRACT FROM AUTHOR]

Motivated by the trend of increasing miniaturization and multifunctional implementation, the electronic transport properties of two silicon carbide (SiC) molecular chains in parallel sandwiched between two semi-infinite Au(100)-3 × 6 electrodes are investigated using the density-functional theory and nonequilibrium Green's function formalism. The π-bonding molecular orbitals resulting from the in-phase combination of two px or py atomic orbitals of the C and Si atoms are found to play a key role in the electronic transport, and the possible electron pathways are summarized. Our results show that changing the separation between the two chains in a certain range can produce remarkable differences in transport properties. When the two chains are in small separation (d = 2.884 Å), their strong electrostatic interaction makes a constructive contribution to the electronic transport properties, in which the underlying physical mechanism has been revealed. We also find that d = 5.768 Å is the critical distance both for the transport difference and for the electrostatic interaction in the top-top configuration. Both the conductance (classical Kirchhoff's superposition law) and the current follow the superposition law well in the atomic scale when d = 5.768 Å, much smaller than the critical distance of 15.5 Å from the result of Zhou et al. [Carbon 95, 503 (2015)]. Additionally, the superposition law is more valid for a larger chain spacing (d ≥ 5.768 Å). Our work demonstrates that the realization of the superposition law and the way of increasing current and rectification effect may lay the foundation for the miniaturization exploration and multifunctional implementation of SiC chain related molecular devices. [ABSTRACT FROM AUTHOR]

We systematically investigate the thermoelectric properties of lanthanum phosphide (LaP) using first-principles calculations together with the Boltzmann transport theory. The dynamic stability of LaP is confirmed based on phonon dispersion. The different atomic masses of La and P atoms lead to an acoustic-optical bandgap that prohibits scattering between acoustic and optical phonon modes. The lattice thermal conductivity κ l is 3.19 W/mK at room temperature, which is less than that of LaAs because of the smaller group velocities and the larger Grüneisen parameter. The calculated phonon-mode contribution to κ l , scattering rate, and mean free path may provide significant guidance to further theoretical and experimental research. The power factor reaches 0.012 W m−1 K−2 at a carrier concentration of 1.05 × 10 20 c m − 3 , which is comparable to the power factor of the typical thermoelectric material Bi2Te3. This reasonable power factor and thermal conductivity suggest that LaP is a promising thermoelectric material. The dependence of the figure of merit ZT on carrier concentration n and temperature T indicates that a high ZT can be obtained by increasing the temperature and tuning the carrier concentration. [ABSTRACT FROM AUTHOR]