双壳类分子生物标志物对海水重金属的响应评述   总被引：1，自引：0，他引：1  

孟范平  高鹰  赵顺顺  付海防  肖静 《中国海洋大学学报(自然科学版)》2011,41(5):100-109

海洋双壳类动物的组织和器官对微量重金属具有高富集能力,诱导机体内的某些分子生物标志物(molecular biomarkers,MBMs)发生变化,可用于指示海水中的重金属污染水平。近10年来,许多学者在双壳类MBMs对海水重金属的响应规律方面进行了研究,其中,金属硫蛋白(MTs)、热激蛋白70(HSP70)、抗氧化防御系统等受到了较多的关注。本文在介绍这些MBMs结构和功能的基础上,重点评述了各种MBMs对海水重金属的响应特征,并提出了影响双壳类MBMs应用于海水重金属监测的因素及进一步研究的方向。  相似文献   

基于多体分析的浅水FPSO和水下软钢臂系泊系统运动特性研究     

李淑一  王树青 《中国海洋大学学报(自然科学版)》2011,41(9):95-102

基于多体动力分析方法进行FPSO和水下软钢臂系泊系统的运动特性研究。相较于非线性弹簧模拟软钢臂系泊系统或者其他近似模拟方法,多体分析方法可以充分考虑系泊系统具体结构形式及其动力项对FPSO运动性能的影响,更好的预报系统运动响应和系泊力。本文将FPSO和水下钢臂结构模拟成2个具有6自由度的独立结构,两者用系泊链组进行连接。基于三维势流理论应用汇源分布法,首先在频域内进行FPSO的水动力参数分析,进而在时域内对系统进行耦合动力分析。本文重点讨论系泊系统黏性力和二阶波浪力对系统响应的影响,计算结果发现系泊系统黏性力对系泊力有一定影响,而在浅水条件下二阶波浪力的计算对准确预报系统运动及系泊力非常重要。  相似文献   

灾害应急远程协同会商系统的设计与集成     

崔璟  黎涛  赵宏  何亚文 《地理信息世界》2011,(4):70-77

传统的电视电话会议,由于空间地域差异或者专业知识的限制,使信息沟通不完整,表述复杂,给会商参与者造成沟通交流障碍.在此基础上,增加分布式地理信息系统,可以使异地参会者实时协作完成各类专题地图制作,增强参会者对会商内容的快速理解,沟通更加便捷,提高会商质量.本文提出灾害应急会商中会议发起人——参会者模式的地图协同标绘应用...  相似文献   

利用数字地震波资料研究宁夏地区介质非弹性衰减和场地响应     

许英才  许文俊  李鸿庭  陈继锋 《大地测量与地球动力学》2011,31(Z1):33-37

利用宁夏及邻区的数字地震波资料,选取2009-05-2010-10月M_L2.6以上的20个台站32次地震事件的268条波形记录,用遗传算法反演了宁夏及邻区介质非弹性衰减系数和台站场地相应.反演得到:宁夏地区介质非弹性衰减Q值与频率的关系为Q(f)=337.67f0.4554.其Q值和山西及浙江地区的结果最相近,可能预...  相似文献   

Plant productivity, predation, and the abundance of black-tailed jackrabbits in the Chihuahuan Desert of Mexico     

L. Hernández  J.W. Laundré  K.M. GrajalesG.L. Portales  J. López-PortilloA. González-Romero  A. GarcíaJ.M. Martínez 《Journal of Arid Environments》2011,75(11):1043-1049

The abundance of black-tailed jackrabbits (Lepus californicus) can fluctuate dramatically. We used data from the Chihuahuan Desert to test the relative strength of top-down (predation) or bottom-up (food availability) limiting forces. Predictions for the top-down hypothesis were, 1) a positive relationship between coyote (Canis latrans) and jackrabbit abundance (numerical response) and 2) a positive relationship between percent occurrence of jackrabbits in coyote scats and jackrabbit abundance (functional response). Predictions for the bottom-up hypothesis were, 1) plant productivity is directly related to precipitation, 2) jackrabbit abundance is positively related to precipitation and plant productivity, and 3) changes in abundance of jackrabbits over the reproductive season will be directly related to precipitation and plant productivity. We found a limited numerical response but no functional response of coyotes to jackrabbit abundance. Forb productivity was significantly related to annual precipitation levels (r² = 0.69, p = 0.002). Grass productivity was related to annual precipitation (r² = 0.34, p = 0.028). Jackrabbit abundance (r² = 0.38, p = 0.002) and changes in abundance (r² = 0.73, p < 0.001) were significantly related to precipitation and forb and grass productivity. We conclude that precipitation levels and plant productivity affect jackrabbit abundance more than predation levels.  相似文献   

The Second James K. Mitchell Lecture Undisturbed sand strength from seismic cone tests     

《Geomechanics and Geoengineering》2013,8(4):239-257

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Seismic response of flexible cantilever retaining walls with dry backfill     

《Geomechanics and Geoengineering》2013,8(4):275-289

Failure of retaining walls during earthquakes has occurred many times in the past. Although significant progress has been made in analysing the seismic response of rigid gravity type retaining walls, considerable difficulties still exist in the seismic-resistant design of the flexible cantilever type of retaining walls because of the complex nature of the dynamic soil–structure interaction. In this paper the seismic response of cantilever retaining walls with dry backfill is simulated using centrifuge modelling and numerical modelling. It is found that bending moments on the wall increased significantly during an earthquake. After the end of base shaking, the residual moment on the wall was significantly higher than the moment under static loading. The numerical simulation is able to model quite accurately the main characteristics of acceleration, bending moment, and displacement recorded in the centrifuge test.  相似文献   

Probabilistic seismic and tsunami hazard analysis for design criteria development of a coastal area in the city of Banda Aceh     

《Geomechanics and Geoengineering》2013,8(1):57-68

Both seismic and tsunami hazards design criteria are essential input to the rehabilitation and long-term development of city of Banda Aceh Post Sumatra 2004 (M _w=9.3) disaster. A case study to develop design criteria for future disaster mitigation of the area is presented. The pilot study consists of probabilistic seismic and tsunami hazard analysis. Results of the probabilistic seismic hazard analysis indicates that peak ground acceleration at baserock for 10 and 2% probability of exceedance in 50 years is 0.3 and 0.55 g, respectively. The analysis also provides spectral values at short (T=0.2 s) and long period (T=1.0 s) motions. Some non-linear time-domain earthquake response analyses for soft, medium, and hard site-class were conducted to recommend design response spectra for each site-class. In addition, tsunami inundation maps generated from probabilistic tsunami hazard analysis were developed through tsunami wave propagation analysis and run-up numerical modeling associated with its probability of tsunamigenic earthquake source potential. Both the seismic and tsunami hazard curve and design criteria are recommended as contribution of this study for design criteria, as part of the disaster mitigation effort in the development process of the city. The methodology developed herein could be applied to other seismic and tsunami disaster potential areas.  相似文献   

HHT法的基本原理及其应用探讨     

张丽娜  李凤臣  彭必全  袁青竹  郑喜亮 《华东地质学院学报》2013,(4):419-423

以Timoshenko单跨梁为研究对象,采用回转射线矩阵法进行动力响应计算,针对Timoshenko梁的瞬态响应信号为非平稳信号,采用基于Hilbert—Huang变换原理的信号时频分析,并与FFT的处理结果进行对比分析。结果表明,HHT方法比Frr法更适合非平稳信号的分析和处理,同时,HHT方法不仅可以将瞬态信号中低频和高频部分分离出来,还可以通过Hilbert谱展示信号能量在时频域内的分布,更为深入的了解信号的本质。  相似文献   

华南沿海2011年7月15—18日持续暴雨过程中的季风槽与中尺度对流系统相互作用   总被引：1，自引：0，他引：1  

蒙伟光  张艳霞  袁金南  李春晖  梁巧倩  吴乃庚 《气象学报》2014,72(3):508-525

应用NCEP FNL再分析资料及位涡分离反演等方法,对华南沿海2011年7月15—18日持续暴雨过程中季风槽与中尺度对流系统的相互作用进行了研究,主要针对暴雨发生期间季风槽气旋性涡度向上发展的机理及其对季风槽维持发展和中尺度对流系统活动的影响进行分析。结果发现,季风槽的中尺度对流系统发展于弱斜压性环境中,大多在槽东西两端涡度中心区发展最强。南侧盛行的西南低空急流为对流反复发生提供了对流发展的“可维持性”条件,是对流得以组织发展成为中尺度对流系统的重要原因。涡度收支诊断表明,季风槽气旋性涡度生成主要由中尺度对流系统低层辐合引起。位涡分离反演结果证实,季风槽气旋性环流增强主要由与中尺度对流系统潜热加热相关的扰动位涡造成,并随着中尺度对流系统加热峰值高度升高而向上发展,是大尺度环流对中尺度对流系统潜热加热动力响应的结果。在季风槽东西两端,由于中尺度对流系统发展强烈且持续,具有更高的加热效率,引起的气旋性涡度向上发展最为明显。其结果可引起中尺度对流系统西南一侧向北非地转风发展,并在地转偏向力作用下增强西风,维持低空急流的发展,为对流反复发生提供条件。这些都说明季风槽大尺度环流与中尺度对流系统相互作用在中尺度对流系统和持续暴雨形成过程中有重要作用。  相似文献