中国明对虾(Fenneropenaeus chinensis)血细胞中一氧化氮合成酶的鉴定及其在白斑综合症病毒感染过程中的变化   总被引：11，自引：0，他引：11  

姜国建  于仁诚  王云峰  颜天  周名江 《海洋与湖沼》2004,35(4):342-350

诱导型一氧化氮合成酶(iNOS)在生物机体免疫，特别在无脊椎动物免疫中的作用近来得到了广泛的关注，由其催化产生的一氧化氯(NO)除具有已知的神经传导、松弛平滑肌等功能外，还具有抗菌、抗病毒、抗寄生虫等作用。作者通过硝基四氯唑蓝(NBT)法和血细胞形态观察等方法，对中国明对虾(Fenneropenaeus chinensis)血细胞中存在的诱导型一氧化氮合成酶进行了初步鉴定。在此基础上，通过亚硝酸盐法和L-瓜氨酸法对比，研究了感染白斑综合症病毒(WSSV)后中国明对虾血细胞中一氧化氯合成酶的变化情况。结果显示，中国明对虾在感染WSSV后，iNOS活性在12h内有上升趋势，实验36h后酶活性显著下降，至60h后酶活性降至对照组的一半左右。同时，被脂多糖(LPS)诱导的一氧化氮合成酶活性与对照相比也有显著下降。与此对应的是，核酸探针斑点杂交法检测病毒的结果显示：实验36h后在对虾体内能够检测到白斑综合症病毒。对照组中国明对虾血细胞的iNOS在实验过程中基本保持稳定。这说明WSSV在感染中国明对虾初期可以诱导血细胞产生iNOS，但随着WSSV在中国明对虾体内的大量增殖及其对血细胞的破坏，使得iNOS活性显著降低，对虾也趋于死亡。因此，iNOS能够作为反映对虾在病毒感染过程中健康状况的有效指标。  相似文献   

Singular points of the polarization tensor     

M. M. Molodensky  L. I. Starkova 《Solar physics》1996,164(1-2):389-396

The problem to compute the magnetic field above the chromosphere using data of the vector = B _t/Bt that gives the projected field direction can be solved with different approximations. The field of direction vectors is, however, not the only field accessible to observations. The Stokes parameters, which are components of the radiation tensor, can be measured at each point of the image plane. The directions of the eigenvectors of the radiation tensor define two mutually orthogonal systems of integral curves in the image plane. These families of curves have singular points, which are generally of different type than those of the vector field. When the morphology of H chromospheric fibrils are used to infer the topology of the magnetic field, a similar problem is met, suggesting that singular points should also be present there.  相似文献   

Probabilistic seismic hazard evaluation in underground mines     

Ewa GłOwacka 《Natural Hazards》1993,7(2):121-132

Stress concentrations produced by rock deformation due to extraction in underground mines induce seismicity that can take the shape of violent and quite dangerous rockbursts.The hazard evaluation presented in this paper is based on a Bayesian probabilistic synthesis of information determined from mining situations during excavation, with previous and present data from microseismicity and seismoacustics.The method proposed in this study is an example of time-dependent on-line seismic hazard evaluation. All results presented were obtained retrospectiely for different underground coal mines in Poland and Czechoslovakia.On leave from Institute of Geophysics, Polish Academy of Sciences 01-452 Warszawa, ul. Ksiecia Janusza 64, Poland.  相似文献   

Electromagnetic methods to characterize the Savoia di Lucania waste dump (Southern Italy)     

M. Bavusi  E. Rizzo  V. Lapenna 《Environmental Geology》2006,51(2):301-308

The aim of this work is the joint application and integration of non-invasive geoelectrical methods for studying the landfill of Savoia di Lucania (Southern Italy). This landfill for its engineering features and small dimensions (70 m × 30 m × 6 m) represents an optimal test site to assess a geophysical survey protocol for municipal solid waste landfills investigation and monitoring. The landfill of Savoia di Lucania has been built with a reinforced concrete material and coated with a high-density polyethylene (HDPE) liner. Three electrical resistivity tomographies (ERT), two self-potential (SP) map surveys and one induced polarization (IP) section have been performed, both in the surrounding area and inside the waste landfill. The geophysical investigations have well defined some buried boundaries of the landfill basin and localized the leachate accumulation zones inside the dumpsite. Comparison of our results with other engineering and geological investigations could be the key for evaluating the integrity of the HDPE liner. Finally, the joint use of the ERT, IP and SP methods seems to be a promising tool for studying and designing new monitoring systems able to perform a time-lapse analysis of waste landfill geometry and integrity.  相似文献   

极化水平层上天然场源激电测深的理论研究   总被引：6，自引：0，他引：6  

李金铭  陈清礼  杨冠鼎  陆桂福 《物探与化探》2003,27(4):280-283,291

采用Dias模型表征介质的激电效应,对三层水平地层中间层为极化层的天然电磁场源激电测深之视电阻率及阻抗相位进行了理论计算.利用中间层充电率m₂≠0和m₂=0时相同频率的视电阻率振幅比和阻抗相位差作为提取激电效应的参数,重点讨论了不同电阻率断面类型对激电测深异常的影响.最后,给出了在一个已知铅锌矿上的试验结果.  相似文献   

湖南东江水库诱发地震   总被引：1，自引：0，他引：1       下载免费PDF全文

胡平  陈献程 《地球物理学报》1997,40(1):66-77

东江水库自蓄水前约半年起就开始进行地震监测，发震后通过密集台网强化观测、震源机制解及地震地质等多项工作，综合研究该库诱发地震发震原因，认为由于库水渗透引起的多种局部性应力调整导致水库诱发地震活动．其发展趋势将表现为逐渐衰减，今后不致于发生破坏性地震．  相似文献   

Aerosol polarized phase function and single-scattering albedo retrieved from ground-based measurements     

Zhengqiang Li  Philippe Goloub  Claude Devaux  Xingfa Gu  Yanli Qiao  Fengsheng Zhao  Hongbin Chen 《Atmospheric Research》2004,71(4):233-241

Aerosol optical parameters, polarized phase function and single-scattering albdeo, have been retrieved from ground-based sun photometer measurements in Beijing 2003. The measured aerosol optical thickness varies from 0.12 to 0.77 with an average value of 0.39. The measured Ångström coefficient ranges from 0.75 to 1.47 with an average value of 1.21. The retrieved single-scattering albedo at 870 nm is within the 0.76–0.94 range and the average value is 0.85, suggests there are considerable aerosol absorptions in Beijing. The maximum value of retrieved polarized phase function at 870 nm ranges from 0.068 to 0.225 with an average value of 0.16, and it illustrates good correlations with the Ångström coefficient, i.e. the relative size of aerosol particles. Analyses of measurements and theoretical calculations show the polarized phase function is sensitive to aerosol size distribution and complex refractive index, especially the imaginary part of the refractive index which denotes aerosol light absorbing effects. These results suggest that the polarized phase function is an effective and unique aerosol optical parameter and is able to improve the retrieval of aerosol physical properties.  相似文献   

全极化SAR数据在地表覆盖/利用监测中的应用   总被引：2，自引：0，他引：2  

陈劲松  邵芸  林晖 《国土资源遥感》2004,15(2):39-42

SIR-C/X-SAR是运行在地球轨道上的第一个多波段(L、C、X)全极化(HH、VV、VH和HV)成像雷达系统,该系统具有极化测量和干涉测量功能。全极化雷达测量每一个像元的全散射矩阵,所获取的信息非常丰富。但是,由于这些极化合成图像具有较高的相关性,导致了图像信息提取精度的降低。本文基于新疆和田地区的SIR-CL波段全极化雷达数据,利用全散射矩阵的特点合成了HH-VV极化相关图像、极化度图像、目标增强图像和相位差图像。这些图像相关性小,地表覆盖信息丰富,提高了全极化SAR数据在实验区信息提取的准确度。  相似文献   

岩石水压致裂和诱发地震的实验研究   总被引：5，自引：0，他引：5  

颜玉定  李亚林  张专  欧阳立胜  谢明富 《中国地震》2005,21(2):193-206

用7种岩石各制备了几类不同预裂纹的系列试件，并在不同围压下进行水压致裂强度实验。结合典型的水库诱发地震的实际资料和现今构造应力场的实验结果，以及应用岩石强度理论和岩石断裂力学的一些原理、方法，进行岩石孔隙水压诱发地震的探讨。初步结果为：(1)若岩体内构造应力很小，一定大小的孔隙水压力σp，可直接使岩体内的薄弱面致裂并发生小地震。(2)若构造应力较大，存在两类诱发地震的可能：①对岩体浅部一些走向与构造应力的主压应力σ1方向相近的薄弱面，σp可促使其发生张性破裂并诱发小地震。②当构造应力接近于断裂的抗剪强度时，因σp，降低了断裂面上的正应力σn，使原处于稳定状态的断裂失稳，发生滑移破裂并诱发出地震。σp导致断裂的破裂深度增大，使诱发地震的震级大于原潜在的地震震级。(3)各种岩体均存在着一个极限深度，此深度后不再有诱发地震。  相似文献   

Characteristic and Geological Significance of Microbially Induced Sedimentary Structures(MISS) in Terrestrial P-T Boundary in Xingyang,Western He’nan Province     

Zheng Wei  Qi Yongan  Zhang Zhonghui  Xing Zhifeng 《地球科学进展》2016,31(7):737-750

Microbially Induced Sedimentary Structures (MISS) are primary sedimentary structures that arise syndepositionally from microbial community activity. Especially valuable are MISS for the analysis of early Archean (and extraterrestrial) deposits. However, most reports of MISS have focused on the Precambrian and Phanerozoic mass extinction marine sediments, and only a few and terrestrial MISS have been studied. The MISS presented in this paper, which mainly consists of mat growth feature, mat destruction feature and mat decay feature, are well preserved in terrestrial clastic rocks around the P-T boundary in Xiyang area, western Henan. Large U ridges, oriented sand quartz, mica grains and thin clayey laminae arranged parallel to bedding plane are the main features visible under the microscope. Several lines of evidence indicate that the Xingyang MISS are of biogenic origin. Abundant MISS in Xingyang may indicate the degradation of terrestrial ecosystems and proliferation of microbial mats immediately after the severe Permian-Triassic mass extinction. Study aiming at MISS helps to analyze their space distribution in the globe and to probe into links between microbial proliferation and environmental stresses following the end-Permian mass extinction in terrestrial ecosystems.  相似文献