试论地震台站监测、科研、预报三结合

本文论述在新形势下地震台站体制、任务改革的必要性与可行性，认为地震台实行地震监测、科研、预报三结合和将单一观测型台站转化成观测－－科研型台站系我国地震台站的发展方向。文中结合牡丹江等地震台的实践对三结合地震台站建设的实施办法和管理体制进行了讨论。     

暴雨模拟中多普勒雷达径向速度变分同化的应用

针对2008年6月广东地区的一次强降雨过程,利用WRF中尺度数值模式及其三维变分同化系统(WRF-3DVAR),进行了多普勒雷达径向速度变分同化对暴雨过程模拟效果影响研究。结果表明:WRF-3DVAR能够有效地同化多普勒雷达径向速度,同化后的主要影响在于改进了初始动力场,使得初始场包含有更详尽的中尺度特征信息,进而显著提高模式对广东局地暴雨过程的模拟效果。在高分辨率中尺度数值模式中有效地利用多普勒天气雷达资料,是提高中尺度降雨预报的关键。     

粒子群算法与支持向量机相结合的热带气旋强度预报试验

支持向量机(SVM)的惩罚参数及核参数的选择直接影响到模型效果,通过粒子群算法(PSO)解决支持向量机的参数选择问题,实现了参数选择的自动化。将该方法应用于热带气旋强度预报,利用气候持续性因子,挑选了1990年的100个左右样本进行预报检验,预报时效为12 h、24 h、36 h、48 h的强度平均绝对误差分别为3.00、4.35、4.93和6.68 m/s。另外,还与国外预报结果及采用最小二乘回归法的预报结果进行了效果的比较,SVM方法显示了更好的预报能力。     

超临界流体热力学函数的理论计算

Ｄｕａｎ等（１９９２。１９９６）基于分子间相互作用势能模型,建立了一个适合于超临界流体的状态方程,此方程能反演出世界上几十个实验室测定的成千上万个纯组分及混合物的ＰＶＴ（压力、体积、温度）数据（温压范围：Ｐ〈２ＧＰａ,Ｔｃ〈Ｔ〈２０００Ｋ）。最近的研究发现,此方程能准确预测Ｈ２Ｏ、ＣＯ２、ＣＨ４、Ｎ２及它们的混合物在Ｔ＝１．３Ｔｃ,Ｐ＝０到Ｔ＝２０００Ｋ,Ｐ＝１０ＧＰａ这一温压范围内的压力、体积、     

短脉冲激光在实验室天体物理方面的研究进展

随着啁啾脉冲放大技术(Chirped Pulse Amplification,CPA)的飞速发展,激光功率密度实现了飞跃式的提升,利用短脉冲激光开展实验室天体物理研究的条件日趋成熟.短脉冲激光与靶相互作用可以产生相对论粒子(正负电子、质子、中子等)和高能电磁辐射(X射线、γ射线),这些粒子和辐射的产生过程与天体中的某些...     

基于GIS与CA的城市扩展研究——以洛阳市为例

元胞自动机(Cellular Automata,CA)是一种自下而上的动态模拟建模框架,具有模拟复杂系统时空演化过程的能力。CA模型的这些特点使得它在城市增长、扩展和土地利用演化模拟等方面较为合适,成为CA应用的热点。探讨利用GIS技术开发CA模型将会改善CA模拟城市扩展的环境,建立典型的城市CA模型也会发现新的参数和转换规则。基于CA原理,结合GIS与RS技术,在ArcGIS平台中进行二次开发,构建了GIS-CA模型系统。以洛阳市为研究区域,对其城市扩展进行了模拟和预测,结果表明,将人为的规划因素加入到CA模型中,打破了CA模型只能模拟城市受自然因素影响而进行的扩展。模拟结果比较真实可信,也为下一步城市规划提供决策支持。     

Liquefaction macrophenomena in the great Wenchuan earthquake

On May 12, 2008 at 14:28, a catastrophic magnitude M 8.0 earthquake struck the Sichuan Province of China.The epicenter was located at Wenchuan (31.00°N, 103.40°E). Liquefaction macrophenomena and corresponding destruction was observed throughout a vast area of 500 km long and 200 km wide following the earthquake. This paper illustrates the geographic distribution of the liquefaction and the relationship between liquefaction behavior and seismic intensity, and summarizes the liquefaction macrophenomena, including sandboils and waterspouts, ground subsidence, ground fissures etc., and relevant liquefaction features. A brief summary of the structural damage caused by liquefaction is presented and discussed. Based on comparisons with liquefaction phenomena observed in the 1976 Tangshan and 1975 Haicheng earthquakes, preliminary analyses were performed, which revealed some new features of liquefaction behavior and associated issues arising from this event. The site investigation indicated that the spatial non-uniformity of liquefaction distribution was obvious and most of the liquefied sites were located in regions of seismic intensity Ⅷ. However, liquefaction phenomena at ten different sites in regions of seismic intensity Ⅵ were also observed for the first time in China mainland. Sandboils and waterspouts ranged from centimeters to tens of meters, with most between 1 m to 3 m. Dramatically high water/sand ejections,e.g., more than 10 m, were observed at four different sites. The sand ejections included silty sand, fine sand, medium sand,course sand and gravel, but the ejected sand amount was less than that in the 1976 Tangshan earthquake. Possible liquefaction of natural gravel soils was observed for the first time in China mainland.     

Set-asides for carbon sequestration: implications for permanence and leakage

This paper examines the potential role of forest set-asides in global carbon sequestration policy. While set asides that protect forests from timber harvests and land-use conversion may alleviate concerns with permanence, and they may provide large ancillary environmental benefits, they may also lead to large leakage. This paper uses a global land use and forestry model to examine the efficiency of three crediting schemes for set-asides. The results show that if set-asides are integrated into a global forestry carbon sequestration program that includes a wide range of other management options, then 300 million hectares of land would be set-aside, and up to 128 Pg C could be sequestered in global forests by 2105. Under alternative policies that focus exclusively on set-asides, more forestland can be set-asides, up to 3.2 billion hectare, but these policies invite large leakage in the near-term, and in the long-run, they less net carbon is removed from the atmosphere. Specifically, leakage is estimated to be 47–52%, depending on the policy, and by the end of the century, up to 17% less carbon will be sequestered in all forests.     

上扬子地区不同类型岩石生氦潜力评价及泥页岩氦气开采条件理论计算

上扬子地区是我国页岩气重要开采区,也是氦气工业性开采的唯一地区,但对于其氦气生成潜力研究仍处于空白阶段.据此,对上扬子东南地区采集的144件岩石样品进行场发射扫描电镜及铀、钍强度测试,理论计算了页岩气中氦气达到我国工业开采标准(0.05％)需要满足的理论条件.岩石扫描电镜结果表明,富含铀、钍的副矿物(锆石、独居石、铀钍石及磷灰石等)主要赋存于造岩矿物石英和长石中.岩石铀、钍强度测试结果表明,三大类岩石中铀平均含量呈现:沉积岩(8.96×10-6)＞岩浆岩(4.83×10-6)＞变质岩(1.89×10-6);钍平均含量呈现:沉积岩(11.01×10-6)≈变质岩(10.4×10-6)＞岩浆岩(5.9×10-6).岩浆岩中铀、钍平均含量呈现:酸性岩＞中性岩＞基性岩＞超基性岩;沉积岩中铀平均含量呈现泥页岩(13.86×10-6)＞＞砂岩(2.54×10-6)＞碳酸盐岩(1.67×10-6);钍平均含量呈现泥页岩(12.50×10-6)≈砂岩(12.76×10-6)＞碳酸盐岩(5.96×10-6).不同沉积时代沉积岩中铀、钍平均含量也呈现上述分布规律.沉积岩中铀、钍含量主要与岩石的沉积环境与物源有关,与沉积时代无关.单位时间、单位质量岩石氦气生成量的大小为:泥页岩＞酸性岩＞中性岩＞砂岩＞变质岩＞碳酸盐岩＞基性岩＞超基性岩.以中国南方地区上奥陶统五峰组—下志留统龙马溪组页岩为例,当该层位泥页岩中残余氦气含量为U,Th元素衰变释放出来氦气含量的80％以上时,适合进行"页岩气+氦气"的共同开采,提高页岩气的开采价值.