A STATISTICAL PROCEDURE TO EVALUATE CLEAN-UP STANDARDS

The object of this paper is to develop a suitable statistical procedure to evaluate clean-up standards athazardous waste sites.Under the assumptions that contaminant masses at a site follow a gammadistribution and that the data from the pre-remediation baseline sample as well as from the interim orfinal sample taken after a certain period of operation are both distributed as gamma with the same shapeparameter but different scale parameters,we derive a uniformly most powerful unbiased test of thehypothesis that a specified percentage of contaminant mass has been reduced.A large-sampleapproximation of the exact test procedure and a comparison with the likelihood ratio test are provided.     

国外煤层气资源与开发概况

介绍了国外主要是美国煤层气的资源、开发状况、勘探开采方法、影响煤层生产能力的地质因素,开发成本、科研机构、会议以及利用概况。     

NONLINEAR COUPLED RESPONSE OF TENSION LEG PLATFORM

A dynamic response analysis of tension leg platform (TLP) to deterministic first order wave forces is presented, considering coupling between various degrees of freedom surge, sway, heave, pitch, roll and yaw. The analysis duly considers nonlinearities produced due to changes in cable-tension and due to nonlinear hydro-dynamic drag forces. The wave forces on the elements of the pontoon structure are calculated using Airy's wave theory and Morison's equation. The nonlinear equation of motion is solved in the time domain by Newmark's β-method. With the help of proposed analysis, some example problems are solved in order to investigate the effects of different important factors that influence the response of TLP.     

宽海洋震源阵列的有效性

近年来,宽海洋震源阵列(wide marine seismic source array)在海洋地震调查中的应用己成为地震工业中令人关心的课题。虽然使用宽阵列的动机之一是在一个震源阵列中携带更多的气枪而不增加阵列在轴向的尺度,但它还有助于抑制侧向散射的能量。对利用宽的和常规宽度震源阵列取自华盛顿及阿拉斯加近海的数据送行共中心点叠加并加以比较表明,其间差     

北美西南早元古宙构造地层地体的拼合

亚利桑那及其邻区内的一条宽500km的早元古宙造山带被北东向和南北向的剪切带分成了若干岩性构造块体。构造和锆石U—Pb同位素研究显示,这些岩性构造块在通过剪切带的逆冲和平移滑动而拼接之前,就经历了不同的构造历史。一个西北地质省在此称为Yavapai省,它至少由5个构造块组成,是在1700Ma左右拼合而成的;每一个东南地质省,此称为Mazatzal省,则至少由3个构造块组成,它们是1695～1630Ma之间的Mazatzal造山运动期间拼合而成并与北西省拼接的。纷乱的表面上互不相容的1700Ma前的构造状态现在成为紧密的近邻。年龄缺乏横向上的系统变化以及变形变质和岩浆作用特征都说明了一个造山带形成北美生的模式,多元的构造地层地体的拼合,这个模式针对以前的北美向南渐进生长的模式提出了另一个适用的假说,也为造山带(1700～1630)的迅速生成原始地壳的大面积增生,北美西南的早元古宙构造作用在时间和样式方面的复杂性提供了一个较好的解释。     

A field survey of chemicals and biological products used in shrimp farming

This study documented the use of chemicals and biological products in marine and brackish water shrimp farming in Thailand, the world's top producer of farmed shrimp. Interviews were conducted with 76 shrimp farmers in three major shrimp producing regions, the eastern Gulf coast, the southern Gulf coast and the Andaman coast area. Farmers in the study used on average 13 different chemicals and biological products. The most commonly used products were soil and water treatment products, pesticides and disinfectants. Farmers in the southern Gulf coast area used a larger number of products than farmers in the other two areas. In the study, the use of more than 290 different chemicals and biological products was documented. Many of the pesticides, disinfectants and antibiotics used by the farmers could have negative effects on the cultured shrimps, cause a risk for food safety, occupational health, and/or have negative effects on adjacent ecosystems. Manufacturers and retailers of the products often neglected to provide farmers with necessary information regarding active ingredient and relevant instructions for safe and efficient use.     

Interaction of oil and mineral fines on shorelines: review and assessment

The interaction of fine mineral particles with stranded oil in an aqueous medium reduces the adhesion of the oil to solid surfaces, such as sediments or bedrock. The net result is the formation of stable, micron-sized, oil droplets that disperse into the water column. In turn, the increase in surface area makes the oil more available for biodegradation. This interaction, referred to as oil–mineral aggregate (OMA) formation, can explain how oiled shorelines are cleaned naturally in the absence of wave action in very sheltered coastal environments. OMA formation also plays an important role in the efficacy of shoreline treatment techniques, such as physical mixing and sediment relocation that move oiled sediments into the zone of wave action to promote the interaction between oil and mineral fines. Successful application of these shoreline treatment options has been demonstrated at two spill events (the Tampa Bay response in Florida and the Sea Empress operation in Wales) and at a controlled oil spill experiment in the field (the 1997 Svalbard ITOSS program). Sediment relocation harnesses the hydraulic action of waves so that the processes of fine-particle interaction and physical abrasion usually occur in tandem on open coasts. There has been no evidence of significant detrimental side-effects of residual oil in pelagic or benthic environments associated with the use of these treatment options to enhance rates of dispersion and oil biodegradation.