Mineralogical characterization of manganese oxide minerals of the Devonian Xialei manganese deposit

The Guangxi Zhuang Autonomous Region is an important manganese ore district in Southwest China, with manganese ore resource reserves accounting for 23% of the total manganese ore resource reserves in China. The Xialei manganese deposit (Daxin County, Guangxi) is the first super-large manganese deposit discovered in China. The Mn oxide in the supergene oxidation zone of the Xialei deposit was characterized using scanning electron microscopy (SEM), energy spectrometer (EDS), transmission electron microscopy (TEM, HRTEM), and X-ray diffraction analysis (XRD). The Mn oxides have a gray-black/steel-gray color, a semi-metallic-earthy luster, and appear as oolitic, pisolitic, banded, massive, and cellular textures. Scanning electron microscopy images show that the manganese oxide minerals are present as fine-spherical particles with an earthy surface. TEM and HRTEM indicate the presence of oriented bundled and staggered nanorods, and nanopores between the crystals. The Mn oxide ore can be classified into two textural types: (1) oolitic and pisolitic (often with annuli) Mn oxide, and (2) massive Mn oxide. Pyrolusite, cryptomelane, and hollandite are the main Mn oxide minerals. The potassium contents of cryptomelane and pyrolusite are discussed. The unit cell parameters of pyrolusite are refined

Suitable ultrasound screening method for older adults with disability to identify low muscle mass

ObjectiveThis study aimed to investigate the accuracy and consistency of different ultrasound protocols for the measurement of gastrocnemius muscle (GM) thickness and to identify a suitable ultrasound scheme that can be used to detect the low muscle mass in older with disability.Materials and methodsIn this cross-sectional study, each participant underwent three different ultrasound protocols for the measurement of the GM thickness, and each measurement was repeated three times. The three measurement schemes were as follows: method A, lying on the examination bed in a prone position with legs stretched and relaxed and feet hanging outside the examination bed; method B, lateral right side lying position with legs separated (left leg flexed and right leg in a relaxed state); and method C, right side lying position with legs together and lower limb muscles in a relaxed state. The low muscle mass was determined by averaging two or three measurements of the GM thickness determined using different sonographic protocols.ResultsThe study included 489 participants. The difference in the prevalence of low muscle mass identified between two and three replicates of the same measurement protocol ranged from 0 to 1.3%. Considering the three repeated measurements of the method A as the reference, the area under the curve (AUC) in different measurement schemes were 0.977-1 and 0.973-1 in males and females, respectively. Furthermore, male and female Kappa values from low to high were 0.773, 0.801, 0.829, 0.839, and 0.967 and 0.786, 0.794, 0.804, 0.819, and 0.984, respectively.ConclusionDifferent ultrasound measurement protocols showed high accuracy and consistency in identifying low muscle mass. Repeating the measurements two or three times was found to be feasible

Differential Antecedents and Consequences of Affective and Cognitive Ruminations

Adopting the information processing perspective, the current study aims to investigate the differential effects of affective and cognitive ruminations on individuals' affective states and learning behavior, and to further explore their differential mediating roles in transmitting effects of challenge and hindrance stressors on affect and behavior. A two-wave survey, in which stressors and ruminations were measured in the first wave and affective states and learning behavior were measured in the second, was conducted to obtain responses from 410 employees. As expected, affective and cognitive ruminations were differently associated with challenge stressors (i.e., cognitive job insecurity) and hindrance stressors (i.e., interpersonal conflict), and yielded different effects in terms of positive affect, negative affect, and learning behavior. Specifically, the results showed that: (a) cognitive job insecurity was significantly and positively related to cognitive rumination, while interpersonal conflict was significantly and positively related to affective rumination; (b) affective and cognitive ruminations were significantly associated with positive or negative affect, but in the exact opposite direction; (c) cognitive rumination, but not affective rumination, was significantly related to learning behavior; and (d) cognitive rumination mediated the effect of cognitive job insecurity on positive affect and learning behavior, while affective rumination mediated the effect of interpersonal conflict on negative affect. The current study contributes to the literature on rumination by introducing a new perspective, and sheds new light on the understanding of how and why affective and cognitive ruminations may lead to different affective states and behaviors

Modeling and simulation for the FAU AUVs: Ocean Explorer

The article of record may be found at http://dx.doi.org/10.1109/OCEANS.1998.726383OCEANS '98 Conference ProceedingsThis paper describes the research progress made on modeling and simulation development for the Florida Atlantic University autonomous underwater vehicles (AUV). Recent addition of simulation components include kinematic effect of longitudinal waves, inertial and position sensor dynamics so that realistic scenarios can be better accommodated. In addition, the existing FAU communication protocol used for the onboard acoustic modem has been ported to the simulation platform, thereby enabling multiple vehicle operations and communication to be simulated. At this stage acoustic propagation for the model is assumed to be ideal although a more realistic model for shallow water propagation will be developed in the near future. This research endeavor is supported by a 5-year ONR MURI project and is jointly carried out by FAU and Naval Postgraduate Schoo

Analysis of Outburst Coal Structure Characteristics in Sanjia Coal Mine Based on FTIR and XRD

In order to reveal the distribution characteristics of functional groups and the difference of microcrystalline structure parameters between outburst coal and primary coal, the coal samples inside and outside the outburst holes of the Sanjia coal mine were examined. The functional groups and microcrystalline structure parameters of outburst coal and primary coal in the Sanjia coal mine were studied by infrared spectroscopy, X-ray diffraction (XRD) experiment and peak-splitting fitting method. The results showed that the substitution mode of the benzene ring in an aromatic structure was mainly benzene ring tri-substituted, with primary coal of 32.71% and outburst coal of 31.6%. The primary coal contained more functional groups, from which hydrogen bonds can easily be formed, meaning that gas is not easily adsorbed by coal. The aromatic hydrogen rate (fHa) of the outburst coal was 0.271, the aromatic carbon rate (ƒC) was 0.986, the aromaticity I1 was 0.477, I2 was 0.373 and the length of the aliphatic branched chain (ACH2/ACH3) was 0.850. Compared with the primary coal, the aromatic hydrogen rate, aromatic carbon rate and the aromaticity of the outburst coal were higher, indicating that the hydrogen and carbon elements in the aromatic functional groups of outburst coal were higher and that the aliphatic functional group was higher than the aromatic structural functional group. ACH2/ACH3 and maturity (Csd) were slightly lower than those of primary coal, indicating that the coal has more straight chains than side chains, while aliphatic hydrocarbons are mostly short chains and have high branched degree. There were obvious 002 and 100 peaks in the XRD pattern. The d002 and d100 of outburst coal were 3.570 and 2.114, respectively, while the number of effective stacking aromatics was 3.089, which was lower than that of primary coal, indicating that the structure of the dense ring in the coal saw certain changes

Study on Crack Penetration Induced by Fatigue Damage of Low Permeability Coal Seam under Cyclic Loading

For low permeability coal seam permeability is weak, low degree of gas migration, prone to gas accidents and other issues. In this paper, a numerical model is established to simulate the process of hydraulic fracturing under monotonic loading and cyclic loading, and a method of increasing permeability of coal seam by cyclic loading hydraulic fracturing technology is proposed. Combined with similar experiments, the influence of cyclic load and cyclic load applied parameters on the fracturing effect of coal and rock mass was analyzed by applying a cyclic load with a pulse pump. The effect of cyclic load pressure technology on coal seam drainage was analyzed by application in 20915 gas control roadways of a coal mine in Guizhou. The results show that after fracturing, the fracture extends along the weak plane of the prefabricated fracture, the pore pressure in the fracture is high pressure, and the pore pressure around the fracture decreases step by step. Due to the compression of the crack, the energy is transferred to the two ends of the crack. The pore pressure has an irregular oval distribution, and there is stress concentration. The pressure value reaches 41.48 MPa. After the cyclic load was applied to the model, the pressure reached the maximum value of 27.64 MPa at 3.37 s. Compared with the monotonic load, the pressure value was reduced by 46.27%. Through pressure and ringing analysis, the fatigue damage of specimens can be realized under cyclic loading. In the experiment, the unconstrained initiation pressure was 2.48 MPa, but after the constraint was applied, the initiation pressure increased to 4.58 MPa, and the pressure increase reached about 55%. After multiple loading and unloading, the peak pressure of the specimen can be reduced and the number of cracks can be increased. In the experiment, the gas extraction rate of ordinary drilling was maintained at about 0.019 m3/min, and the gas extraction rate of ordinary fracturing drilling fluctuated at 0.025 m3/min after 21 days of gas extraction. The pumping capacity of 15 Hz and 20 Hz cyclic loading fracturing boreholes tended to be stable after 15 days, which were about 0.041 m3/min and 0.062 m3/min, respectively. Cyclic loading hydraulic fracturing is better than monotonic loading hydraulic fracturing, and the lower the cyclic loading frequency, the better the fracturing effect

Geothermal characteristics and formation mechanism of the Medi River in Bijie City, Guizhou Province

To study the formation mechanism and hydration characteristics of geothermal resources and provide a reference for the comprehensive utilization and development of resources. Collect the water samples from Midi River in Bijie City, Guizhou Province, analyze the hydrochemical characteristics, and adopt the Piper trilinear diagram, geothermal and landmark method and audio magnetotelluric method to study the geothermal hydration and formation mechanism of Midi River. The research indicates: affected by Pingzhai dome structure, the internal joint structure in the dome is very developed in this region, which is conducive to the migration of deep thermal water to the relatively low area in the dome, forming the convective underground thermal water resources of the fold dome structure.Through regional fault detection, it is inferred that there are five shattered fault zones (or fissures) in this region, among which F4 and F13 faults have steep occurrence and shallow downward extension; F9 is more pronounced and tends to be northwest; F1 has a nearly northsouth trend, tends to northwest, and extends deeper; F17 and F18 are more obvious, but the extension is shallow. It is inferred that the F1 fault has good thermal control lability and is a favorable position for underground thermal water upwelling. Heating of the surrounding rock is obtained within 2 500 m depth of runoff after receiving infiltration recharge water from atmospheric precipitation in the rim of Pingzhai dome, and a deep pressure-bearing thermal reservoir is formed in the dolomite of Dengying Formation of Sinian System under the action of overlying Cambrian clastic rock water-resisting and heat-preservation overburden. The analysis of hydrochemical characteristics shows that geothermal water is low-salinity water. Na+ is the main positive ion in geothermal well water, accounting for approximately 45%, followed by Ca2+ and Mg2+, accounting for approximately 49%. HCO3- accounts for the main negative ion, SO42- accounts for 39%, and Cl- accounts for almost no, so the chemical type of geothermal water is HCO3-·SO42--Na·Ca; the geothermal reservoir temperature of the geothermal well is 53.98℃, the geothermal gradient is 2.85℃/100 m, and the circulation depth of the geothermal water is approximately 2 500 m.The research results have a good guiding significance for the exploitation and utilization of geothermal resources in Bijie City, Guizhou Province

Quantitative Analysis of Anesthesia Recovery Time by Machine Learning Prediction Models

It is significant for anesthesiologists to have a precise grasp of the recovery time of the patient after anesthesia. Accurate prediction of anesthesia recovery time can support anesthesiologist decision-making during surgery to help reduce the risk of surgery in patients. However, effective models are not proposed to solve this problem for anesthesiologists. In this paper, we seek to find effective forecasting methods. First, we collect 1824 patient anesthesia data from the eye center and then performed data preprocessing. We extracted 85 variables to predict recovery time from anesthesia. Second, we extract anesthesia information between variables for prediction using machine learning methods, including Bayesian ridge, lightGBM, random forest, support vector regression, and extreme gradient boosting. We also design simple deep learning models as prediction models, including linear residual neural networks and jumping knowledge linear neural networks. Lastly, we perform a comparative experiment of the above methods on the dataset. The experiment demonstrates that the machine learning method performs better than the deep learning model mentioned above on a small number of samples. We find random forest and XGBoost are more efficient than other methods to extract information between variables on postoperative anesthesia recovery time

Ubiquitous Occurrence of a Biogenic Sulfonate in Marine Environment

The biogenic sulfonate 2,3-dihydroxypropane-1-sulfonate (DHPS) is a vital metabolic currency between phytoplankton and bacteria in marine environments. However, the occurrence and quantification of DHPS in the marine environment has not been well-characterized. In this study, we used targeted metabolomics to determine the concentration of DHPS in the Pearl River Estuary, an in situ costal mesocosm ecosystem and a hydrothermal system off Kueishantao Island. The results suggested that DHPS occurred ubiquitously in the marine environment, even in shallow-sea hydrothermal systems, at a level comparable to that of dimethylsulfoniopropionate. The concentration of DHPS was closely related to phytoplankton community composition and was especially associated with the abundance of diatoms. Epsilonproteobacteria were considered as the most likely producers of DHPS in shallow-sea hydrothermal systems. This work expands current knowledge on sulfonates and presents a new viewpoint on the sulfur cycle in hydrothermal systems

Application and investigation of thrombopoiesis-stimulating agents in the treatment of thrombocytopenia

Platelets, derived from a certain subpopulation of megakaryocytes, are closely related to hemostasis, coagulation, metastasis, inflammation, and cancer progression. Thrombopoiesis is a dynamic process regulated by various signaling pathways in which thrombopoietin (THPO)–MPL is dominant. Thrombopoiesis-stimulating agents could promote platelet production, showing therapeutic effects in different kinds of thrombocytopenia. Some thrombopoiesis-stimulating agents are currently used in clinical practices to treat thrombocytopenia. The others are not in clinical investigations to deal with thrombocytopenia but have potential in thrombopoiesis. Their potential values in thrombocytopenia treatment should be highly regarded. Novel drug screening models and drug repurposing research have found many new agents and yielded promising outcomes in preclinical or clinical studies. This review will briefly introduce thrombopoiesis-stimulating agents currently or potentially valuable in thrombocytopenia treatment and summarize the possible mechanisms and therapeutic effects, which may enrich the pharmacological armamentarium for the medical treatment of thrombocytopenia