53 research outputs found
Study on crustal deformation of the Ms6. 6 Damxung earthquake in 2008 by InSAR measurements
Abstract:Three Envisat images from ESA were used to derive the pre – and co-seismic deformation interfereograms caused by the Damxung Ms6. 6 earthquake of Oct. 6, 2008, by using InSAR. The result shows no significant crustal motion more than 4 months before the earthquake, but a maximum co-seismic displacement of about 0.3m in an epicentral area of 20km × 20km. The deformation field was symmetrically distributed about a NS axis, where the west side subsided and the east side uplifted. We used a linear elastic dislocation model in half space and a nonlinear constraint optimized algorithm to estimate the slip distribution along the fault. The results indicates that the epicenter is located at 90.374°E, 29.745°N with a moment magnitude of Mw6. 35. The earthquake is dominated by normal faulting with a maximum slip of 3m on a 12km × 11km fault plane striking S189°W, dipping 60° to NW at a depth of 9.5km, and is located at a sub-fault of the southeastern Piedmont of the Nyainqentanglha mountains. The relatively shallow depth of earthquake is related to relatively high heat flow in the area
雷公藤红素通过靶向核受体Nur77促进损伤线粒体自噬而抑制炎症反应
文章简介线粒体在细胞死亡、自噬、免疫和炎症中起着不可或缺的作用。前期研究发现,孤儿核受体Nur77通过靶向线粒体诱导细胞凋亡。本文报道了Nur77作为具有抗炎作用的雷公藤红素的直接靶点,介导雷公藤红素通过自噬清除损伤线粒体,抑制炎症反应而达到治疗炎症疾病包括肥胖症的功能。研究人员发现,雷公藤红素的结合
Pattern Recognition of Development Stage of Creepage Discharge of Oil–Paper Insulation under AC–DC Combined Voltage Based on OS-ELM
The recognition of the creepage discharge development process of oil–paper insulation under AC–DC combined voltage is the basis for fault monitoring and diagnosis of converter transformers; however, only a few related studies are available. In this study, the AC–DC combined voltage with a ratio of 1:1 was used to develop a recognition method for the creepage discharge development process of an oil–paper insulation under a cylinder–plate electrode structure. First, the pulse current method was used to collect the discharge signals in the creepage discharge development process. Then, 24 characteristic parameters were extracted from four types of creepage discharge characteristic spectra after dimensionality reduction. Finally, based on the online sequential extreme learning machine (OS-ELM) algorithm, these characteristic parameters were used to recognize the development stage of the creepage discharge of the oil–paper insulation. The results showed that when the size of the sample training set used in the OS-ELM algorithm is close to the number of hidden layer neurons, a high recognition accuracy can be obtained, and the type of activation function has little influence on the recognition accuracy. Four stages of the creepage discharge development process were recognized using the OS-ELM algorithm; the trend was the same as that of the characteristic parameters of the entire creepage discharge development process. The recognition accuracy was 91.4%. The algorithm has a high computing speed and high accuracy and can train data in batches. Therefore, it can be widely used in the field of online monitoring and evaluation of electrical equipment status
Pattern Recognition of Development Stage of Creepage Discharge of Oil–Paper Insulation under AC–DC Combined Voltage Based on OS-ELM
The recognition of the creepage discharge development process of oil–paper insulation under AC–DC combined voltage is the basis for fault monitoring and diagnosis of converter transformers; however, only a few related studies are available. In this study, the AC–DC combined voltage with a ratio of 1:1 was used to develop a recognition method for the creepage discharge development process of an oil–paper insulation under a cylinder–plate electrode structure. First, the pulse current method was used to collect the discharge signals in the creepage discharge development process. Then, 24 characteristic parameters were extracted from four types of creepage discharge characteristic spectra after dimensionality reduction. Finally, based on the online sequential extreme learning machine (OS-ELM) algorithm, these characteristic parameters were used to recognize the development stage of the creepage discharge of the oil–paper insulation. The results showed that when the size of the sample training set used in the OS-ELM algorithm is close to the number of hidden layer neurons, a high recognition accuracy can be obtained, and the type of activation function has little influence on the recognition accuracy. Four stages of the creepage discharge development process were recognized using the OS-ELM algorithm; the trend was the same as that of the characteristic parameters of the entire creepage discharge development process. The recognition accuracy was 91.4%. The algorithm has a high computing speed and high accuracy and can train data in batches. Therefore, it can be widely used in the field of online monitoring and evaluation of electrical equipment status
An Open Integrated Rock Spectral Library (RockSL) for a Global Sharing and Matching Service
Minerals and rocks are important natural resources that are formed over a long period of geological history. Spectroscopy is the basis of the identification and characterisation of rocks and minerals via proximal sensing in the field or remote sensing systems with multi- and hyper-spectral capabilities. However, spectral data is scattered around different institutions worldwide and stored in various formats, resulting in poor data usability and an unnecessary waste of time and information. To improve the usability and performance of mineral spectral data, we developed an integrated open mineral spectral library (Rock Spectral Library, RockSL). Shared spectral data and related information were collected worldwide, and data cleaning measures were performed to retain the qualified spectra and merge all qualified data (raster, vector, and text formats) in a common framework to establish a reliable and comprehensive digital data set for an easy sharing and matching service. A software system was developed for the RockSL to manage, analyse, and apply the spectral data of minerals and rocks. We demonstrate how the information encoded in RockSL can determine the species of unknown rocks and describe specific mineral compositions. We also provide a reference scheme of the work chain and present key technologies for building different spectral libraries in diverse fields using RockSL. New contributions to RockSL are encouraged for this work to be improved to provide a better service and extend the applications of geo-sciences. This article introduces the characteristics of RockSL and demonstrates an experimental application
Blood Pressure Characteristics in Moderate to Severe Renal Insufficiency
Background/Aims: Ambulatory blood pressure monitoring (ABPM) in chronic kidney disease (CKD) patients has been extensively studied, but few investigations have attempted to relate ABPM with CKD stages. The objectives of this article were to compare ABPM parameters for the diagnosis and treatment determination of CKD with daytime clinic blood pressure (BP) measurements. We also investigated BP and renal injury in combined hypertension and CKD. We supposed ABPM was important in combined hypertension and CKD. Methods: We compared ABPM in hypertension patients, including 152 patients with combined hypertension and CKD. Patients with combined hypertension and CKD were grouped according to severity into stages 1 through 3 (Stage 1-3) and stages 4 and 5 (Stage 4-5). Results: In the Stage 4-5 group, systolic BP (SBP) (daytime, nighttime and 24 h mean), diastolic BP (DBP), pulse pressure and SBP standard deviations (SD) (daytime and 24 h) were higher. SBP and DBP loads were significantly higher in the Stage 4-5 group. The nighttime load was higher than the daytime load. Mean arterial pressure (MAP) was higher and heart rates (HR) were faster in the Stage 4-5 group. Conclusions: BP load should be a component employed in ABPM to determine cardiovascular risk stratification. MAP and HR might be associated with risk to develop end-stage renal disease
Reduction of Friction and Soil Adhesion of Medium Carbon Steel via Hard Coating and Surface Texture
Rapid development of mechanical cultivation demands satisfactory wear performance and lower soil adhesion on the soil-engaging components of terrain machinery. A thick 2Cr13 hard coating was used in conjunction with surface textures in this sector. The results showed that 2Cr13 coating and surface texture decreased the friction coefficient and wear rate enormously. The surface wettability of the coating was reduced by a dimpled-surface texture. The adhesion test suggested that dimples greatly decreased the adhesion force by decreasing the friction component and the decrement increased with the increase of dimple size. The adhesion force increased with the soil moisture and then decreased when exceeding the moisture content threshold
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