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[en] On the basis of 10 935 broadband velocity records of 135 earthquakes ML3.0–6.4 and epicentral distance of 26–623 km) occurred from May 12 to June 10 in 2008, which are collected from 27 bedrock stations included in Sichuan Earthquake Monitoring Network, the corresponding acceleration records are obtained by a real-time simulation method. Then by regression analysis on the data, the relation between the peak ground acceleration and velocity attenuation of small and moderate bedrock earthquakes occurred in Sichuan region is acquired. And the relation is verified by a M4.8 earthquake took place recently in Wenchuan. Finally, the attenuation relations, which are coincident to the geological conditions in Sichuan region, are proposed by studying the records from Sichuan earthquake network.
[en] Earthquake early warning (EEW) systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the Southeast coast of China. It is anticipated that the system will be completed in time to be tested at the end of this year (2013). In order to evaluate how much advanced warning the EEW system will be able to provide different cities in Fujian, we established an EEW information release scheme based on the seismic monitoring stations distributed in the region. Based on this scheme, we selected 71 historical earthquakes. We then obtained the delineation of the region’s potential seismic source data in order to estimate the highest potential seismic intensities for each city as well as the EEW system warning times. For most of the Fujian Province, EEW alarms would sound several seconds prior to the arrival of the destructive wave. This window of time gives city inhabitants the opportunity to take protective measures before the full intensity of the earthquake strikes.
[en] Bulk magneto-phonon and magnetic polaritons of lateral antiferromagnetic superlattices for potential THz applications have been investigated in the framework of the effective medium theory. The dispersion relations applied for the system are displayed. In contrast with lateral FeF_2/SiO_2 superlattice, some fascinating polariton modes with negative group velocity signifying photonic band gap scenarios and attractive optical properties are observed from the numerical results presented with the example, lateral FeF_2/TlBr superlattice. - Highlights: • Bulk magneto-phonon and magnetic polaritons in the THz frequency regime are discussed. • Negative refraction at certain frequencies is predicted in lateral FeF_2/TlBr superlattice. • This appealing nature can be adjusted by the applied magnetic field and the antiferromagnetic volume fraction.
[en] Objective: To investigate the method of 99Tcm-methoxyisobutylisonitrile (MIBI) lung imaging and its value for the diagnosis of lung neoplasms. Methods: 99Tcm-MIBI lung imaging was performed on 44 cases with lung neoplasms, 28 with benign lesions, and 12 normal controls. The characters of the nodules were defined by the images and the semiquantitative measurements of the early T/N ratio (ER) and delayed T/N ratio (DR). Results: The value of ER in control, benign and malignant group was 1.02 ± 0.10, 1.15 ± 0.13, 1.51 ±0.26, respectively. The value of DR in these three groups was 1.01 ±0.10, 1.14 ±0.13, 1.43 ± 0.21, respectively. While ER≥1.28, or DR≥1.27 were defined as positive, the sensitivity was 88.6% and 84.1%, the specificity 85.7% and 92.9%, the accuracy 87.5% and 87.5%, respectively. Conclusion: 99Tcm-MIBI lung imaging is very useful for differentiating benign and malignant pulmonary nodules
[en] Objective: To evaluate the clinical application value of nuclide bone imaging in malignant lymphoma. Methods: 71 cases of patients were diagnosed by pathology as malignant lymphoma, among whom there were 8 cases of Hodgkin disease (HL) and 63 cases of non-Hodgkin disease (NHL). The examinations were performed from 2.5 to 6 hours later after the intravenous injection of 99mTc-MDP (555-925 MBq). Results: 31 cases were bone-infiltrating lesions, including 3 cases of HL and 28 cases of NHL. The total number of the focus was 103, except 2 cases of bone lack, including 35 foci in vertebral column (34.65%), 30 foci in limb and joint (29.70%), 14 foci in rib (13.86%), 13 foci in elvis (12.0%), 5 foci in skull (4.95%) and 4 foci in sternum (3.96%). Conclusion: The nuclide bone imaging has a high value in the clinical stage, therapeutic observation and prognosis of bone-infiltrating malignant lymphoma. (authors)
[en] In this article, the seismic records of Japan’s Kik-net are selected to measure the acceleration, displacement, and effective peak acceleration of each seismic record within a certain time after P wave, then a continuous estimation is given on earthquake early warning magnitude through statistical analysis method, and Wenchuan earthquake record is utilized to check the method. The results show that the reliability of earthquake early warning magnitude continuously increases with the increase of the seismic information, the biggest residual happens if the acceleration is adopted to fit earthquake magnitude, which may be caused by rich high-frequency components and large dispersion of peak value in acceleration record, the influence caused by the high-frequency components can be effectively reduced if the effective peak acceleration and peak displacement is adopted, it is estimated that the dispersion of earthquake magnitude obviously reduces, but it is easy for peak displacement to be affected by long-period drifting. In various components, the residual enlargement phenomenon at vertical direction is almost unobvious, thus it is recommended in this article that the effective peak acceleration at vertical direction is preferred to estimate earthquake early warning magnitude. Through adopting Wenchuan strong earthquake record to check the method mentioned in this article, it is found that this method can be used to quickly, stably, and accurately estimate the early warning magnitude of this earthquake, which shows that this method is completely applicable for earthquake early warning.
[en] According to earthquake catalog records of Fujian Seismic Network, the Tnow method and the four-station continuous location method put forward by Jin Xing are inspected by using P-wave arrival information of the first four stations in each earthquake. It shows that the four-station continuous location method can locate more seismic events than the Tnow method. By analyzing the results, it is concluded that the reason for this is that the Tnow method makes use of information from stations without being triggered, while some stations failed to be reflected in earthquake catalog because of discontinuous records or unclear records of seismic phases. For seismic events whose location results can be given, there is no obvious difference in location results of the two methods and positioning deviation of most seismic events is also not significant. For earthquakes outside the network, the positioning deviation may amplify as the epicentral distance enlarges, which may relate to the situation that the seismic stations are centered on one side of epicenter and the opening angle between seismic stations used for location and epicenter is small.
[en] We wanted to evaluate the feasibility of catheter-directed thrombolysis with a continuous infusion of low-dose urokinase for treating non-acute (less than 14 days) deep venous thrombosis of the lower extremity. The clinical data of 110 patients who were treated by catheter-directed thrombolysis with a continuous infusion of low-dose urokinase for lower extremity deep venous thrombosis was analysed. Adjunctive angioplasty or/and stenting was performed for the residual stenosis. Venous recanalization was graded by pre- and posttreatment venography. Follow-up was performed by clinical evaluation and Doppler ultrasound. A total of 112 limbs with deep venous thrombosis with a mean symptom duration of 22.7 days (range: 15-38 days) were treated with a urokinase infusion (mean: 3.5 million IU) for a mean of 196 hours. After thrombolysis, stent placement was performed in 25 iliac vein lesions and percutaneous angioplasty (PTA) alone was done in fi ve iliac veins. Clinically significant recanalization was achieved in 81% (90 of 112) of the treated limbs: complete recanalization was achieved in 28% (31 of 112) and partial recanalization was achieved in 53% (59 of 112). Minor bleeding occurred in 14 (13%) patients, but none of the patients suffered from major bleeding or symptomatic pulmonary embolism. During followup (mean: 15.2 months, range: 3-24 months), the veins were patent in 74 (67%) limbs. Thirty seven limbs (32%) showed progression of the stenosis with luminal narrowing more than 50%, including three with rethrombosis, while one revealed an asymptomatic iliac vein occlusion: 25 limbs (22%) developed mild post-thrombotic syndrome, and none had severe post-thrombotic syndrome. Valvular reflux occurred in 24 (21%) limbs. Catheter-directed thrombolysis with a continuous infusion of low-dose urokinase combined with adjunctive iliac vein stenting is safe and effective for removal of the clot burden and for restoration of the venous flow in patients with non-acute lower extremity deep venous thrombosis
[en] We present a new strategy to estimate the geometry of a rupture on a finite fault for rapid reporting of seismic intensity. We use envelope attenuation relationships which were presented by Huo et al. (Acta Seismol Sin 16:519–525, 1994). An important base of this work is the fault finiteness theory. We propose a new model to simulate high-frequency motions from earthquakes with large rupture dimension. The envelope of high-frequency ground motion from a large earthquake can be expressed as a root-mean-squared combination of envelope functions from smaller earthquakes. We use simulated envelopes of ground acceleration to estimate the direction and along-strike length of a rupture. Using the Wenchuan and Jiji (Chi-Chi) earthquake dataset, we parameterize the fault geometry with an epicenter, a fault strike, and along-strike rupture lengths. So this methodology seems quite appropriate for the rapid reporting systems of seismic intensity.
[en] Pulsed plasma thruster (PPT) is widely used in space propulsion due to its high reliability, specific impulse and systematic simpleness, but its improvement has been troubled for years by its low efficiency. In this paper, a novel laser assisted pulsed plasma thruster (LAPPT) prototype is designed, in which the traditional spark ignitor is replaced by 532nm laser. With a series of experimental test on LAPPT, the enhancement of impulse bit, specific impulse, impulse coupling coefficient is confirmed. This study introduces a novel method to improve PPT’s performance and set a solid foundation for further research. (paper)