The strong earthquakes and seismogenic structures in eastern margin of Tibetan Plateau and adjacent areas: A preface for the special topic

The eastern margin of the Tibetan Plateau is composed of multiple secondary tectonic units which constitute typical “multi-level extrusion-rotation active tectonic system”. It is the tectonic transformation belt that regulates the eastward extrusion of plateau blocks, and contains high-density active faults. This area is characterized by frequent and high intensity strong earthquakes and complex geological and geomorphological features. Therefore, this region is one of the areas in China where the problem of earthquake disaster is particularly significant. In recent years, with the research deepening of the national earthquake disaster risk survey, active fault detection of urban，seismic experimental site construction, seismic safety evaluation of engineering sites, identification of active faults and evaluation of crustal stability in major projects sites and urban areas，and the wide application of high-precision remote sensing, tectonic geomorphology, paleoseismic and Quaternary chronology methods. The investigation of seismogenic structures around the eastern margin of the Tibetan Plateau and its adjacent areas has been significantly improved. In order to timely exchange the latest study results in this field support regional earthquake prevention and disaster reduction and geological safety evaluation of important projects sites and infrastructure construction, the journal editorial department of Progress in Earthquake Science organized the special topic “The strong earthquakes and seismogenic structures in eastern margin of Tibetan Plateau and adjacent areas”. More than 20 representative academic papers such as active faults and earthquakes, Jishishan earthquake in Gansu Province，and research reviews in related fields have been collected. In this issue, 10 papers are selected in the special topic I “The strong earthquakes and seismogenic structures in eastern margin of Tibetan Plateau and adjacent areas”. It is hoped that these newly study results may improve the understanding of characteristics of strong earthquake activity and seismogenic structural mechanism in the region, and provide scientific basis for regional strong earthquake risk analysis and effective prevention of strong earthquake disaster risk

Spectral domain optical coherence tomography for embryo heart flow measurement

AbstractThe measurement of blood-plasma velocity distributions with high spatial and temporal resolution in vivo is important for the investigation of embryonic heart at its early stage development. Optical Coherence Tomography is a non-invasive imaging modality with high resolution (5 to 20μm) that can provide flow velocity information by calculating the Doppler frequency shift. In this paper, a high speed spectral optical coherence tomography system was demonstrated. An achievable scanning speed of 92k line/sec has been reached by using an ultra-high speed linear array CCD camera. The measurable flow velocity range is [-24,24]mm/s using this system. Early stage Chicken embryo heart blood flow was measured in vivo

A continuous contact force model for impact analysis

Hunt and Crossley proposed a general expression of the contact force in 1975. The dissipative force term of the general expression has two exponents: the exponent of indentation depth and that of velocity. Because it is almost impossible to obtain an analytical solution based on the general expression, more than twenty continuous contact models have been developed based on the simplification of the general expression. In these studies, the exponent of the indentation depth was set as 0.25, 0.5, 0.65, 1.0 or 1.5, and the exponent of the velocity was set to 1.0. This paper proposes a new continuous contact force model with arbitrary values of the exponents of the indentation depth and velocity. The model is based on the general expression of the contact force. Considering the rule of energy equivalence, an approximate dynamic equation is developed by introducing the equivalent indentation and equivalent velocity. Subsequently, a new contin-uous contact force model is constructed based on the system dynamic equation and approximate dynamic equation. The influences of the two exponents on the performance of the continuous contact force models are investigated by analyzing the simulation results. Moreover, the validity of the new model is demonstrated by comparing the simulation results with two published experimental datasets. The comparison also indicates that the performance of the continuous contact model can be enhanced by selecting appropriate values of the two exponents

Reproductive output of the brown frog Rana kukunoris at high altitude of the Tibetan plateau

Rana kukunoris is endemic to the eastern Tibetan plateau and its breeding ecology was not known so far. In this study, we investigated the reproductive output patterns of the species during the breeding periods of 2012 and 2013. Our results showed that clutch size and total clutch volume increased with maternal body size. However, no significant correlation between egg number and egg size was observed, which suggested that the tradeoff between offspring number and size in this species was lack

Cryoablation of cardiophrenic angle lymph node metastases: a case report

Abstract Background Cardiophrenic angle lymph node metastases are relatively rare. Surgical resection is the main treatment for cardiophrenic angle lymph node metastasis, but it is not always possible. Case presentation Here, we report our initial experience with cryoablation of a cardiophrenic angle lymph node metastasis from liver cancer. As the cardiophrenic angle lymph node metastasis was located close to the heart, about 200 mL of 0.9% saline was injected into the pericardium to separate the heart from the target area. The cardiophrenic angle lymph node metastasis was successfully ablated, without any complications. Conclusions Cryoablation may be a suitable alternative treatment for cardiophrenic angle lymph node metastasis

Study on Damage Evaluation and Machinability of UD-CFRP for the Orthogonal Cutting Operation Using Scanning Acoustic Microscopy and the Finite Element Method

Owing to high specific strength and designability, unidirectional carbon fiber reinforced polymer (UD-CFRP) has been utilized in numerous fields to replace conventional metal materials. Post machining processes are always required for UD-CFRP to achieve dimensional tolerance and assembly specifications. Due to inhomogeneity and anisotropy, UD-CFRP differs greatly from metal materials in machining and failure mechanism. To improve the efficiency and avoid machining-induced damage, this paper undertook to study the correlations between cutting parameters, fiber orientation angle, cutting forces, and cutting-induced damage for UD-CFRP laminate. Scanning acoustic microscopy (SAM) was employed and one-/two-dimensional damage factors were then created to quantitatively characterize the damage of the laminate workpieces. According to the 3D Hashin’s criteria a numerical model was further proposed in terms of the finite element method (FEM). A good agreement between simulation and experimental results was validated for the prediction and structural optimization of the UD-CFRP