Acquisition and Evaluation of Thermodynamic Data for Bieberite-Moorhouseite Equilibria at 0.1 MPa

Published estimates for the equilibrium relative humidity (RH) at 25 °C for the reaction: bieberite (CoSO4•7H2O) = moorhouseite (CoSO4•6H2O) + H2O, range from 69.8 to 74.5%. To evaluate these data, the humidity-buffer technique was used to determine equilibrium constants for this reaction between 14 and 43 °C at 0.1 MPa. Reversals along fi ve humidity-buffer curves yield ln K = 18.03–6509.43/T, where K is the equilibrium constant, and T is temperature in K. The derived standard Gibbs free energy of reaction is 9.43 kJ/mol, which agrees well with several previously reported values based on vaporpressure measurements. It also agrees well with values calculated from the data derived mostly from calorimetric measurements. Previous studies indicated that the temperature of the invariant point for the assemblage bieberite-moorhouseite-aqueous solution-vapor is near 44.7 °C, and our extrapolated data predict 91.1% RH at this temperature; the predicted position for the invariant point is in excellent agreement with those reported previously

Lithium enrichment of the magmatic-hydrothermal fluid in albite-spodumene pegmatite from Lijiagou, Eastern Tibetan Plateau: Evidence from fluid inclusions

Albite-spodumene pegmatites, which are remarkable resources of Li worldwide, may experience both magmatic-hydrothermal transition and sub-solidus hydrothermal alteration during their formation and evolution. However, fluids involved in the different stages of the evolution of a spodumene-bearing pegmatitic systems are not well defined, especially at the magmatic-hydrothermal transition stage. In the Lijiagou deposit, western Sichuan Province, fluid inclusions of a typical albite-spodumene pegmatite were studied to determine the degree of magmatic-hydrothermal fluid Li enrichment and the potential for lithium mineral crystallization at the magmatic-hydrothermal transition stage. Micro-petrographic analyses identified different types of fluid inclusions of either primary, pseudo-secondary or secondary origin and inclusions containing devitrified silicate glass. The presence of these inclusions suggests that the pegmatite underwent both the magmatic-hydrothermal transition stage and a post-crystallization hydrothermal process over its evolution. The results of fluid inclusion LA-ICP-MS analyses show that the aqueous ± carbonic fluids represented by the pseudo-secondary type 1a and 1b inclusions carry significant amount of Li, with Na and Li predominating the cation budget of these pegmatitic fluids. The aqueous ± carbonic fluids exhibit typical magmatic-hydrothermal fluid compositional characteristics and exhibit high abundance of Li in this pegmatitic system at the magmatic-hydrothermal transition stage. The relative abundance of Li to Na and K lies within the uppermost range of those reported from lithium-cesium-tantalum pegmatite systems. This is consistent with the elevated incorporation of Li in pegmatitic quartz from the albite-spodumene pegmatite. The compositional characteristics of the fluids at the magmatic-hydrothermal transition stage may be used to imply the Li mineralization potential of the pegmatitic system

CaS: A key medium for C-O-S-Ca cycles in Earth

Oldhamite (CaS) is a rare mineral, which is only observed naturally in enstatite meteorites.No occurrence of CaS has been documented from other groups of meteorites and terrestrial samples. However, in experiments at 1.5 GPa/1510 K and 0.5 GPa/1320 K, when the lgfo2 is lower than -10.57 (FMQ-0.52), CaS was produced in this study by a two-melt mechanism involving the reaction between molten pyrrhotite-pentlandite-bearing orthopyroxenite and molten CaCO3. CaS can be easily oxidized to form CaSO4 or hydrolyzed to produce calcium hydroxide, which may explain why it has never been found in geological samples from Earth. We speculate that part of the anhydrite and gypsum in black smokers along mid-ocean ridges are related to the oxidation or hydrolysis of CaS in the underlying mantle. CaS can be produced when the Siberian mantle plume intruded into the lithosphere.Comment: The third versio

Detecting critical nodes for network vulnerability assessment under cascading failures

Recently, the major challenge in the robustness evaluation of networks is to enhance the detecting the most critical nodes. Many researchers have studied the problem of detecting the list of attacked nodes, which are the number of failed nodes is maximum, in order to protect these nodes. However, there is no any previous works to consider the cost of attacks that the budget is limited is very practical in the real attacks. In this paper, we study the problem of attacking nodes in networks to maximize the total profits of attacked nodes, where the total cost of attacks is remained under the budget. In addition, an algorithm is proposed to solve problem of attacking nodes in the network with limited budget while guaranteeing the high total profits of attacked nodes. Simulation results show that the proposed method provides good performance

Observation of interlayer phonon modes in van der Waals heterostructures

We have investigated the vibrational properties of van der Waals heterostructures of monolayer transition metal dichalcogenides (TMDs), specifically MoS2/WSe2 and MoSe2/MoS2 heterobilayers as well as twisted MoS2 bilayers, by means of ultralow-frequency Raman spectroscopy. We discovered Raman features (at 30 ~ 40 cm-1) that arise from the layer-breathing mode (LBM) vibrations between the two incommensurate TMD monolayers in these structures. The LBM Raman intensity correlates strongly with the suppression of photoluminescence that arises from interlayer charge transfer. The LBM is generated only in bilayer areas with direct layer-layer contact and atomically clean interface. Its frequency also evolves systematically with the relative orientation between of the two layers. Our research demonstrates that LBM can serve as a sensitive probe to the interface environment and interlayer interactions in van der Waals materials

Chinese Herbal Medicine Therapy and the Risk of Mortality for Chronic Hepatitis B Patients with Concurrent Liver Cirrhosis: a Nationwide Population-Based Cohort Study

Chronic hepatitis B (CHB) is increasingly recognized as a public health problem in Taiwan. After affected patients are diagnosed with contaminant liver cirrhosis (LC), adverse clinical outcomes, especially death, are common. This study aimed to investigate the effect of Chinese herbal medicine (CHM), an essential branch of Traditional Chinese medicine (TCM), on the mortality risk among CHB patients with contaminant LC. This longitudinal cohort study used the Taiwanese National Health Insurance Research Database to identify 1522 patients 20–70 years of age with newly diagnosed CHB with LC during 1998–2007. Among them, 508 (33.37%) had received CHM products after the onset of CHB (CHM users), and the remaining 1014 patients (66.63%) were designated as a control group (non-CHM users). All enrollees were followed until the end of 2012 to determine deaths during the study period. We applied the Cox proportional hazards regression model to compute the hazard ratio for the association of CHM use and the subsequent risk of death. During the follow-up period, 156 CHM users and 493 non-CHM users died. After controlling for potential confounders, CHM users were found to have a significantly reduced risk of death compared with non-CHM users by 56%, and the effect was predominantly observed among those treated with CHM for \u3e 180 days. CHM therapy lowered the risk of death among CHB patients with contaminant LC, which supported CHM might provide further treatment options for those with chronic liver diseases

Power Spectral Analyses of Index Finger Skin Blood Perfusion in Carpal Tunnel Syndrome and Diabetic Polyneuropathy

The main purpose of this study was to investigate the applicability of frequency domain analysis on laser Doppler flowmetry (LDF) data recorded from the index fingers of patients with carpal tunnel syndrome (CTS) and diabetic polyneuropathy (DPN). Patients with numbness of the palm were recruited and grouped according to the results of electrophysiological examinations into 2×2 groups by the existence or nonexistence of CTS and/or DPN. Skin blood perfusion was recorded by LDF in both the neutral position and the maximally flexed position (the Phalen test). S-transformation was utilized to decompose the recorded data into frequency bands, and the relative band power and power dispersion were calculated. Analysis of variance was used to test the effects of DPN, CTS, and the Phalen test results. The results showed that (1) DPN decreased the absolute power and the relative power in some frequency bands in both positions and CTS increased the power dispersion of some frequency bands only during the Phalen test and (2) there was no difference in the LDF results between patients with positive or negative Phalen test results

ZAK negatively regulates RhoGDIβ-induced Rac1-mediated hypertrophic growth and cell migration

RhoGDIβ, a Rho GDP dissociation inhibitor, induced hypertrophic growth and cell migration in a cultured cardiomyoblast cell line, H9c2. We demonstrated that RhoGDIβ plays a previously undefined role in regulating Rac1 expression through transcription to induce hypertrophic growth and cell migration and that these functions are blocked by the expression of a dominant-negative form of Rac1. We also demonstrated that knockdown of RhoGDIβ expression by RNA interference blocked RhoGDIβ-induced Rac1 expression and cell migration. We demonstrated that the co-expression of ZAK and RhoGDIβ in cells resulted in an inhibition in the activity of ZAK to induce ANF expression. Knockdown of ZAK expression in ZAK-RhoGDIβ-expressing cells by ZAK-specific RNA interference restored the activities of RhoGDIβ

Layers of Metal Nanoparticles on Semiconductors Deposited by Electrophoresis from Solutions with Reverse Micelles

Pd nanoparticles were prepared with reverse micelles of water/AOT/isooctane solution and deposited onto silicon or InP substrates by electrophoresis. A large change of capacitance-voltage characteristics of mercury contacts on a semiconductor was found after Pd deposition. This change could be modified when the Pd deposition is followed by a partial removal of the deposited AOT. The deposited Pd nanoparticles were investigated by optical mictroscopy, SIMS and SEM. Finally, Schottky diodes with barrier height as high as 1.07 eV were prepared by deposition of Pd nanoparticles on n-type InP and by a partial removal of superfluous AOT. These diodes are prospective structures for further testing as hydrogen sensors