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1.
Based on the information theory and multifractals viewpoint, the information dimension D_1 of acoustic emission (AE) of rock for marble, gabbro and sandstone in a laboratory condition and seismic activities before and after some large earthquakes are studied. The results show that there is a dimension reduction process before the failure of rock and before the occurrence of large earthquakes. The curves of D_1 determined during the process have a wider non-scaling range. Moreover, the non-scaling range became narrow when rock was close to failure fracture and large earthquake was just to happen. This shows that the system has instable critical behavior.  相似文献   

2.
We have measured radon and thoron activities in soil-gases since July 9, 1997 Cariaco earthquake (Mw=6.9) until the end of 2000. Carbon dioxide concentrations were also monitored between 1998–2000. The soil-gas was collected between 50–55 cm depths at two sampling points at Altos de pipe (Instituto Venezolano de Investigaciones Cientificas-IVIC) near Caracas, Venezuela. The radon and thoron measurements were performed daily employing radiation monitors with scintillation cells and the carbon dioxide was monitored with portable gas analyzers. Average weekly and monthly values were calculated and plotted for this three-four year period. In general, both the radon and carbon dioxide values showed sinusoidal trends due to seasonal changes. During the dry season the radon and carbon dioxide values decreased, while the radon activity was relative constant (flat) during the rainy season at one of the sampling points. Only two monthly radon values were seen to be anomalous in the graphs in respect to seven anomalous periods for the average weekly values. No anomalous periods were clearly seen for carbon dioxide. Finally, it was difficult to try to relate these radon anomalous periods with specific earthquakes due to the large number of minor earthquakes during these years, but it seem that the minor earthquake (Mb=5.9) of October 4, 2000 could be associated with the radon anomalous period in September, when there were no other minor earthquakes (Mb≥4.0). This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

3.
云南省位于多个地块交界处,构造活动活跃且地震活动频发。利用中国静止气象卫星风云二号系列相当黑体温度TBB数据,应用小波变换和相对傅氏功率谱的时频相对功率谱方法(T-F RPS),提取并分析了云南省2008年至今发生的5.5级以上地震热红外异常信息,且对比分析了特征周期、特征幅值、异常形态、异常演化过程等参数。结果表明:(1)该系列地震热红外异常信息易于用时频相对功率谱方法(T-F RPS)提取识别,且异常特征具有"出现-扩大-减小-消失"的规律;(2)异常特征周期和持续时间也具有一定的规律性;(3)异常沿着断层延展,震中位于异常边缘一侧或者异常区域交汇地带,发震时刻多位于相对功率谱幅值下降阶段;(4)震级与相对功率谱峰值有一定的相关性,震级高,峰值也较高;(5)地震类型与异常面积有一定的相关性,双震型地震异常面积较大。此外,讨论了地震热红外异常与构造活动、气候状况、天气情况和季节等因素的关系。  相似文献   

4.
Uranium groundwater anomalies and active normal faulting   总被引:1,自引:0,他引:1  
The ability to predict earthquakes is one of the greatest challenges for Earth Sciences. Radon has been suggested as one possible precursor, and its groundwater anomalies associated with earthquakes and water?Crock interactions were proposed in several seismogenic areas worldwide as due to possible transport of radon through microfractures, or due to crustal gas fluxes along active faults. However, the use of radon as a possible earthquake??s precursor is not clearly linked to crustal deformation. It is shown in this paper that uranium groundwater anomalies, which were observed in cataclastic rocks crossing the underground Gran Sasso National Laboratory, can be used as a possible strain meter in domains where continental lithosphere is subducted. Measurements evidence clear, sharp anomalies from July, 2008 to the end of March, 2009, related to a preparation phase of the seismic swarm, which occurred near L??Aquila, Italy, from October, 2008 to April, 2009. On April 6th, 2009 an earthquake (Mw = 6.3) occurred at 01:33 UT in the same area, with normal faulting on a NW?CSE oriented structure about 15 km long, dipping toward SW. In the framework of the geophysical and geochemical models of the area, these measurements indicate that uranium may be used as a possible strain meter in extensional tectonic settings similar to those where the L??Aquila earthquake occurred.  相似文献   

5.
The cutoff frequency f_(max) of radiation from earthquakes is one of the important parameters for studying the source process. By theoretical analysis and numerical experiments on acceleration Fourier spectrum it is suggested that f_(max) mainly depends on the lower values of slip rise time. This result can be used to explain the observational fact that the greater the earthquake magnitude, the smaller the value of f_(max).  相似文献   

6.
The work showed a phenomenon of influence of seismic and resonance shock waves on the long-range order in a liquid. On examples of damage of ion pair solvated clusters in aqueous solutions of NaCl (3.5 wt%), HCl (2 wt%), AgNO3 (1.7 wt%) and molecular bunches (clusters) in distilled water placed to laboratory chemical reactor far distant from the epicenters of earthquakes the relations between incoming shock and seismic waves and instability of cluster and supracluster long range organization (molecular bunches assocoates) in a liquid is demonstrated. Understanding of risks for chemical industry both in respect of quality and chemical processes instability, and in respect of loose control over chemical technology is considered. Examples of changes in internal organization of solutions in the period of strong hurricane in Europe at February 17, 2007, strong earthquake in Japan at March 25, 2007 and a series of earthquakes at April 4 to 9, 2007 are given and the phenomenon is explained. The risks for chemical industry and the chances of practical using the phenomenon are considered. The clusters in liquids show different responses to the processes in the disaster epicenter, and their responses can be used for understanding chemical processes in Earth crust and in the centers of hurricanes and for strategy of disposing and protecting chemical facilities.  相似文献   

7.
Continuous radon monitoring in soil and groundwater is one of the useful methods in earthquake prediction process. There are many published studies on geochemical precursors to seismic activity, both reporting the detection of validated precursory phenomena. The research on geochemical precursory algorithms is aimed at defining quantitative relations between seismogenic parameters and endogenetic components. This paper presents a new analytical algorithm that can be used to estimate optimum location and magnitude of coming earthquakes based on variations in radon concentration or any other geochemical precursors. In a real life application of this algorithm, radon monitoring network for Kerman province has been designed and the resulting data have been investigated. This practical example corroborates the proposed algorithm as well and the resulting seismogenic parameters e.g. location and magnitude have been obtained within their acceptable ranges. Furthermore, the proposed algorithm emphasizes on hot-springs which have the most effect on results around target zone.  相似文献   

8.
The earthquakes cause appearance of new geological fault and dislocation of rock stratum; the original permeable rock breaks, then the fault can conduct water under the effect of pressure; the stratum with radionuclide is dislocated and connected to the water-conducting fault under the effect of the fault. Under the effect of water the stratum with seepage and the one with radionuclide link up. It causes radioactive pollution on underground water, based on which this paper does a research and makes an analysis of the radioactive pollutant concentration that diffuses along the top and bottom section and centre line of the fault following the seepage. It turns out that in the rock stratum with seepage suffering rupture, the radioactive pollutant effects an elliptical spherical diffusion. In the turning point of the fault, the elliptical sphere makes a turn following the seepage.  相似文献   

9.
The 238U(γ, n)237U reaction cross-section at the end point bremsstrahlung energies of 8 and 10 MeV was measured by using an activation technique. Induced gamma ray activities were measured by high resolution gamma-ray spectrometer with high-purity germanium detector. The photo neutron cross section on 238U is also calculated theoretically using TALYS 1.2 computer code. The experimentally obtained reaction cross sections were compared with the flux weighted average values from the literature data based on mono-energetic photon as well as the value from TALYS. It was found that the cross section of 238U(γ, n)237U reaction increases with increase of bremsstrahlung energy and were closer to the flux-weighted experimental data from literature and the values from TALYS based on mono-energetic photons.  相似文献   

10.
Journal of Solid State Electrochemistry - The electrochemistry-related scientific activities in Hungary over the past 3 decades are reviewed. In the first section, we summarize those research areas...  相似文献   

11.
The pharmacological activities of synthetic human CCK-33, in which a tyrosine molecule was sulfated by arylsulfotransferase, were investigated in the rat and the guinea-pig. The activities were compared with those of non-sulfated CCK-33 (CCK-33NS), CCK-8 and CCK-4. CCK-33 was about 100 fold more potent than non-sulfated CCK-33(CCK-33NS) but was about 20 fold less potent than CCK-8 in the contraction of the isolated gallbladder of the guinea-pig. In rat pancreatic secretion, intravenous CCK-33 and CCK-8 showed almost the same activity. The potency of each was about 1000 fold more than the individual potency of CCK-33NS, non-sulfated CCK-8 (CCK-8NS) and CCK4. There were no significant differences in gastric acid stimulatory activities among CCK-33, CCK-8, CCK-4, but the activities of CCK-33NS and CCK-8NS were less than those of CCK-33 and CCK-8, respectively. CCK-33 and CCK-8 produced a reduction in the intake of powder chow in doses of 10(-8) and 3 x 10(-8) mol/kg i.p., but CCK-33NS, CCK-8NS and CCK-4 did not. In conclusion, the activities of synthetic human CCK-33 are almost the same as those of CCK-8 on exocrine pancreatic secretion, gastric acid secretion and food intake, but less than CCK-8 on isolated gallbladder contraction.  相似文献   

12.
The double irradiation technique, which is used to detect the production of a given nuclide from different chemical elements, by two different reactions in a polyenergetic neutron flux, cannot be generally applied. The application limits have been defined and calculated, based on the statistical fluctuation of the measured activities. The experimental verification and the practical applications of the calculated limits for activation analysis, and transmutation reaction cross section studies are discussed.  相似文献   

13.
Gastrodia elata (G. elata), as a natural plant with nourishing and edible value, plays a vital role in food and pharmaceutical production. In the present study, a novel approach for the simultaneous determination of six components based on high‐performance liquid chromatography (HPLC) coupled with photodiode array detection (PDA) was developed for the quality evaluation of G. elata from different regions. Meanwhile, antioxidant and α‐glucosidase inhibitory activities were estimated and compared. The results indicated that the total contents of the six compounds in G. elata from Guizhou and Zhejiang provinces obtained by boiling were higher than those obtained by steaming in Anhui and Yunnan provinces. In addition, samples from Guizhou, Yunnan and Shanxi provinces contained more p‐hydroxybenzyl alcohol, and always possessed higher antioxidant activity, while samples collected from Anhui province showed the highest α‐glucosidase inhibitory activity with the highest gastrodin content. The results revealed that the quality of G. elata was affected by different regions and different initial processing technologies, which provided a reference for the selection and application of G. elata.  相似文献   

14.
The results of thermodynamic study of Pb-BiIn section of Pb-Bi-In system done experimentally by Oelsen calorimetry and calculated by general solution model, as well as measurements performed by DTA and optic microscopy in order to investigate phase diagram of the given section, are presented in this paper. Thermodynamic properties, such as integral molar enthalpies of mixing, activities, activity coefficients, partial and integral excess Gibbs energies at 600 and 650 K were determined and comparison between obtained experimental and calculated values were done. Also, based on cooling curves, DTA recordings and optic microscopy results phase diagram was constructed and compared with literature data.  相似文献   

15.
In recent hundred years the annual discharge variations of the Changjiang River (represented by the Yichang station) and the Huanghe River (represented by Shanxian and Tangnaihe, respectively) have closely related to the geographical distribution of the earthquakes coming about in China in the same year, Both the occurrence of the destructive seism or seismic swarm in the river basins and the disappearance of the shocks in the east and south of the basins are the conditions that the Changjiang and Huanghe Rivers are the high flow while that the strong earthquake of magnitude 7 or more occurred in North China is the condition for the Changjiang low flow year and that of 6 or more in the Qilian Mountains area is for the Huanghe River. In the latter part of this paper, a 2-year sample is given to explain that the conditions of the 2 rivers being high flow years are that the north-south seismic belt is active and in the meanwhile no seism occurred in South China, and those of the low flow year are that the  相似文献   

16.
The reaction process of the production of CrOH(C2H4)2(+) was studied in connection with the ethylene polymerization on a silica-supported chromium oxide catalyst (the Phillips catalyst). Cluster ions CrOH(C2H4)2(+) and CrOH(C4H8)+ were produced by the reactions of CrOH+ with C2H4 (ethylene) and C4H8 (1-butene), respectively, and were allowed to collide with a Xe atom under single collision conditions. The cross section for dissociation of each parent cluster ion was measured as a function of the collision energy (collision-induced dissociation, or CID). It was found that (i) the CID cross section for the production of CrOH+ from CrOH(C2H4)2(+) increases sharply at the threshold energy of 3.16 +/- 0.22 eV and (ii) the CID cross section for the production of CrOH+ and C4H8 from CrOH(C4H8)+ also increases sharply at the threshold energy of 3.26 +/- 0.21 eV. In comparison with the calculations based on a B3LYP hybrid density functional method, it is concluded that two ethylene molecules in CrOH(C2H4)2(+) are polymerized to become 1-butene. The calculation also shows that the dimerization proceeds via CrOH(C2H4)+ (ethylene complex) and CrOH(C2H4)2(+) (ethylene complex), in which the ethylene molecules bind with CrOH+ through a pi-bonding.  相似文献   

17.
It is found that zeolite-like crystalline aluminophosphates VPI-5, Si-VPI-5, and Mn-VPI-5 as well as those dirived from them, AlPO{in4}-8, SAPO{in4}-8, and MnAPO{in4}-8, are capable of catalyzing aldol condensation and crotonization of butyraldehyde (BA). Pd/AlPO{in4}-8 is catalytically active in hydrocondensation of BA with H{in2} at atmospheric pressure. The activities in BA conversion to 2-ethylhexane-3-ol-1-al increase in the following order: Mn-VPI-5 < Si-VPI-5 < VPI-5. The same order of activities is also found for AlPO{in4}-8, SAPO{in4}-8, and MnAPO{in4}-8. These catalysts are characterized by a lower initial activity in crotonization of BA than M{su+}NaX (CsNaX), but they are much more stable. Pd/AlPO{in4}-8 catalyzes BA conversion to 2-ethylhexanal even in the absence of H{in2} feed to the reaction zone. The influence of catalyst pretreatments and experimental conditions on the catalyst structures and catalytic activities is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khmicheskaya, No. 12, pp. 2123–2129, December, 1994.  相似文献   

18.
Pierre Duhem was a multifaceted and prolific scientist active in thermodynamics, physics, history, and philosophy. His rigid and noncompromising attitude, together with deep religious feelings at a time when France was riding a very strong wave of anticlericalism, led to his being unable to teach in Paris and to academic exile in the provinces. He was a prolific writer and he left his name on many equations such as the Gibbs-Duhem and Duhem-Margules equations. We present here a general picture of his life and activities against the political climate in France as well as a discussion of some of his most important contributions to thermodynamics.  相似文献   

19.
In order to discover new molecules with good insecticidal activities, a series of anthranilic diamides containing polyfluoroalkyl pyrazole were designed and synthesized, and their structures were characterized by 1H NMR and HRMS. Bioassays demonstrated that some of the title compound exhibited excellent insecticidal activities. The larvicidal activities of compound 8a, 8c, 8g, 8k and 8l against Mythimna separata Walker were 100% at 0.8 mg/L. The insecticidal activities of compound 8a, 8c, 8e, 8g, 8k and 8l against Plutella xylostella Linnaeus were 100% at 0.4 mg/L. Surprisingly compounds 8a and 8c still showed 100% larvicidal activities against Plutella xylostella Linnaeus at 0.08 mg/L comparable to the commercialized Chlorantraniliprole. The LC50 of compound 8a and 8c against M. separata is 0.048 and 0.043 mg/L respectively.  相似文献   

20.
组蛋白去乙酰化酶(HDACs)是近年来治疗肿瘤的重要靶标之一.由于HDACs包含多种亚型,且各亚型的生理功能存在一定的差异,其选择性抑制剂的开发已成为当前的研发热点.我们通过同源模建的HDAC1结构,与已有的HDAC8晶体结构的活性位点进行比较分析,探讨了对两者选择性有重要影响的残基,为基于受体的选择性抑制剂研究提供重要信息.同时选择了52个HDAC抑制剂,分别建立了HDAC1、HDAC8的活性值与对接打分值的线性回归模型.所建的HDAC1和HDAC8的线性构效关系模型的非交叉验证系数R2分别为0.82和0.80,表明具有一定的统计学意义.利用所建模型对已设计合成的化合物进行了预测,预测结果对HDAC1、HDAC8选择性抑制剂的优化改造提供了一定的指导意义.  相似文献   

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