The Indoor Thermal Environment Simulation and Testing Validation of a Power Plant Turbine Room in Extreme Cold Area

AbstractThis paper conducts an analysis study on indoor thermal environment of a steam turbine room in power plant by CFD. Refer to a typical steam turbine room in an actual thermal power plant which has been conducted field test, the typical numerical simulation model is built including a reasonable indoor heat conditions, structural parameters and envelope architectural opening, flow boundary conditions. Indoor air temperature distribution and air velocity distribution of steam turbine room is obtained. Comparing the simulation results with the corresponding field measurement data on typical location show that two sets of results are very close. So accuracy and applicability of CFD simulations is proved. It is also proved that complete method for CFD simulations of the paper is appropriate for interior thermal environment study of typical steam turbine room and thus laid the foundation for the further studies of a large number of universal cases

Thermal Infrared Anomalies of Several Strong Earthquakes

In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of “time-frequency relative power spectrum.” (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting

Growth/differentiation factor 1 alleviates pressure overload-induced cardiac hypertrophy and dysfunction

AbstractPathological cardiac hypertrophy is a major risk factor for developing heart failure, the leading cause of death in the world. Growth/differentiation factor 1 (GDF1), a transforming growth factor-β family member, is a regulator of cell growth and differentiation in both embryonic and adult tissues. Evidence from human and animal studies suggests that GDF1 may play an important role in cardiac physiology and pathology. However, a critical role for GDF1 in cardiac remodelling has not been investigated. Here, we performed gain-of-function and loss-of-function studies using cardiac-specific GDF1 knockout mice and transgenic mice to determine the role of GDF1 in pathological cardiac hypertrophy, which was induced by aortic banding (AB). The extent of cardiac hypertrophy was evaluated by echocardiographic, hemodynamic, pathological, and molecular analyses. Our results demonstrated that cardiac specific GDF1 overexpression in the heart markedly attenuated cardiac hypertrophy, fibrosis, and cardiac dysfunction, whereas loss of GDF1 in cardiomyocytes exaggerated the pathological cardiac hypertrophy and dysfunction in response to pressure overload. Mechanistically, we revealed that the cardioprotective effect of GDF1 on cardiac remodeling was associated with the inhibition of the MEK–ERK1/2 and Smad signaling cascades. Collectively, our data suggest that GDF1 plays a protective role in cardiac remodeling via the negative regulation of the MEK–ERK1/2 and Smad signaling pathways

The serum matrix metalloproteinase-9 level is an independent predictor of recurrence after ablation of persistent atrial fibrillation

OBJECTIVES: This study investigated whether the serum matrix metalloproteinase-9 level is an independent predictor of recurrence after catheter ablation for persistent atrial fibrillation. METHODS: Fifty-eight consecutive patients with persistent atrial fibrillation were enrolled and underwent catheter ablation. The serum matrix metalloproteinase-9 level was detected before ablation and its relationship with recurrent arrhythmia was analyzed at the end of the follow-up. RESULTS: After a mean follow-up of 12.1±7.2 months, 21 (36.2%) patients had a recurrence of their arrhythmia after catheter ablation. At baseline, the matrix metalloproteinase-9 level was higher in the patients with recurrence than in the non-recurrent group (305.77±88.90 vs 234.41±93.36 ng/ml, respectively, p=0.006). A multivariate analysis showed that the matrix metalloproteinase-9 level was an independent predictor of arrhythmia recurrence, as was a history of atrial fibrillation and the diameter of the left atrium. CONCLUSION: The serum matrix metalloproteinase-9 level is an independent predictor of recurrent arrhythmia after catheter ablation in patients with persistent atrial fibrillation

Aberrant Functional Connectivity of the Orbitofrontal Cortex Is Associated With Excited Symptoms in First-Episode Drug-Naïve Patients With Schizophrenia

BackgroundSchizophrenia (SZ) is associated with the highest disability rate among serious mental disorders. Excited symptoms are the core symptoms of SZ, which appear in the early stage, followed by other stages of the disease subsequently. These symptoms are destructive and more prone to violent attacks, posing a serious economic burden to the society. Abnormal spontaneous activity in the orbitofrontal cortex had been reported to be associated with excited symptoms in patients with SZ. However, whether the abnormality appears in first-episode drug-naïve patients with SZ has still remained elusive.MethodsA total of 56 first-episode drug-naïve patients with SZ and 27 healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI) and positive and negative syndrome scale (PANSS). First, differences in fractional amplitude of low-frequency fluctuations (fALFF) between first-episode drug-naïve patients with SZ and healthy controls were examined to identify cerebral regions exhibiting abnormal local spontaneous activity. Based on the fALFF results, the resting-state functional connectivity analysis was performed to determine changes in cerebral regions exhibiting abnormal local spontaneous activity. Finally, the correlation between abnormal functional connectivity and exciting symptoms was analyzed.ResultsCompared with the healthy controls, first-episode drug-naïve patients with SZ showed a significant decrease in intrinsic activity in the bilateral precentral gyrus, bilateral postcentral gyrus, and the left orbitofrontal cortex. In addition, first-episode drug-naïve patients with SZ had significantly reduced functional connectivity values between the left orbitofrontal cortex and several cerebral regions, which were mainly distributed in the bilateral postcentral gyrus, the right middle frontal gyrus, bilateral paracentral lobules, the left precentral gyrus, and the right median cingulate. Further analyses showed that the functional connectivity between the left orbitofrontal cortex and the left postcentral gyrus, as well as bilateral paracentral lobules, was negatively correlated with excited symptoms in first-episode drug-naïve patients with SZ.ConclusionOur results indicated the important role of the left orbitofrontal cortex in first-episode drug-naïve patients with SZ and suggested that the abnormal spontaneous activity of the orbitofrontal cortex may be valuable to predict the occurrence of excited symptoms. These results may provide a new direction to explore the excited symptoms of SZ

The Influencing Mechanisms on Global Industrial Value Chains Embedded in Trade Implied Carbon Emissions from a Higher-Order Networks Perspective

As the division of labor in global industrial value chains deepens, the embedded relationships and carbon emission relationships among countries become more complex. First, calculate the embedding indices of forward and backward global industrial value chains and establish the Multi-Regional Input Output (MRIO) model to calculate trade-implied carbon emissions. Second, construct higher-order weighted networks characterized by hypergraphs from 2000 to 2018, and calculate a high-dimensional vector of characteristic indicators based on apices and hyperedges. Finally, time exponential random graph models are constructed using maximum pseudo-likelihood estimation and Markov Monte Carlo simulation methods to dynamically observe the evolution of the impact mechanism of forward and backward industrial value chains embedded in trade-implied carbon emissions networks. The conclusions obtained are as follows: First, most countries tend to develop backward industries when embedded in global industrial value chains. Second, based on the Global Industry Classification Standard (GICS) criteria, industries deeply embedded in global forward value chains are mainly concentrated in materials and utilities, etc., while industries more deeply embedded in global backward value chains are mainly concentrated in consumer discretionary and real estate industries, etc. Third, “carbon transfer” and “carbon leakage” gradually widen the gap between developed and developing countries, both on the production and consumption sides. Fourth, we decompose the factors influencing industrial carbon emissions into carbon intensity effects, industrial structure effects, and output scale effects and analyze their influence mechanisms. Fifth, for countries with different carbon flow attributes, their forward and backward embedded global industrial value chains have different effects on trade-implied carbon emissions. Sixth, the effective paths of trade that lead to a reduction in carbon emissions are different for countries with different carbon flow characteristics

The Influencing Mechanisms on Global Industrial Value Chains Embedded in Trade Implied Carbon Emissions from a Higher-Order Networks Perspective

As the division of labor in global industrial value chains deepens, the embedded relationships and carbon emission relationships among countries become more complex. First, calculate the embedding indices of forward and backward global industrial value chains and establish the Multi-Regional Input Output (MRIO) model to calculate trade-implied carbon emissions. Second, construct higher-order weighted networks characterized by hypergraphs from 2000 to 2018, and calculate a high-dimensional vector of characteristic indicators based on apices and hyperedges. Finally, time exponential random graph models are constructed using maximum pseudo-likelihood estimation and Markov Monte Carlo simulation methods to dynamically observe the evolution of the impact mechanism of forward and backward industrial value chains embedded in trade-implied carbon emissions networks. The conclusions obtained are as follows: First, most countries tend to develop backward industries when embedded in global industrial value chains. Second, based on the Global Industry Classification Standard (GICS) criteria, industries deeply embedded in global forward value chains are mainly concentrated in materials and utilities, etc., while industries more deeply embedded in global backward value chains are mainly concentrated in consumer discretionary and real estate industries, etc. Third, “carbon transfer” and “carbon leakage” gradually widen the gap between developed and developing countries, both on the production and consumption sides. Fourth, we decompose the factors influencing industrial carbon emissions into carbon intensity effects, industrial structure effects, and output scale effects and analyze their influence mechanisms. Fifth, for countries with different carbon flow attributes, their forward and backward embedded global industrial value chains have different effects on trade-implied carbon emissions. Sixth, the effective paths of trade that lead to a reduction in carbon emissions are different for countries with different carbon flow characteristics

Influence of the Heights of Low-Level Jets on Power and Aerodynamic Loads of a Horizontal Axis Wind Turbine Rotor

The influence of the heights of low-level jets (LLJs) on the rotor power and aerodynamic loads of a horizontal axis wind turbine were investigated using the fatigue, aerodynamics, structures, and turbulence code. The LLJ and shear inflow wind fields were generated using an existing wind speed spectral model. We found that the rotor power predicted by the average wind speed of the hub height is higher than the actual power in relatively weak and shallow LLJ inflow conditions, especially when the LLJ height is located inside the rotor-swept area. In terms of aerodynamic loads, when the LLJ height is located inside the rotor-swept area, the root mean square (RMS) rotor thrust coefficient and torque coefficient increase, while the RMS rotor unbalanced aerodynamic load coefficients, including lateral force, longitudinal force, tilt moment, and yaw moment, decreased. This means that the presence of both positive and negative wind shear in the rotor-swept area not only increases the rotor power but also reduces the unbalanced aerodynamic loads, which is beneficial to the operation of wind turbine. Power spectrum analysis shows no obvious difference in the power spectrum characteristics of the rotor torque and thrust in LLJ inflow conditions with different heights