Comparison of velocity-log data collected using impeller and electromagnetic flowmeters

Previous studies have used flowmeters in environments that are within the expectations of their published ranges. Electromagnetic flowmeters have a published range from 0.1 to 79.0 m/min, and impeller flowmeters have a published range from 1.2 to 61.0 m/min. Velocity-log data collected in five long-screened production wells in the Pleasant Valley area of southern California showed that (1) electromagnetic flowmeter results were comparable within +/-2% to results obtained using an impeller flowmeter for comparable depths; (2) the measured velocities from the electromagnetic flowmeter were up to 36% greater than the published maximum range; and (3) both data sets, collected without the use of centralizers or flow diverters, produced comparable and interpretable results. Although either method is acceptable for measuring wellbore velocities and the distribution of flow, the electromagnetic flowmeter enables collection of data over a now greater range of flows. In addition, changes in fluid temperature and fluid resistivity, collected as part of the electromagnetic flowmeter log, are useful in the identification of flow and hydrogeologic interpretation.     

The Spectroscopic Orbit of the Planetary Companion Transiting HD 209458

Three new silicon-bearing radicals of astrophysical interest, SiCCH and the two nearly isoenergetic isomers SiCN and SiNC, were detected in a laboratory discharge in their X2Pi ground states by Fourier transform microwave and millimeter-wave absorption spectroscopy. Hyperfine structure was observed in the low rotational transitions of the (2)Pi(1/2) ladder, and well-resolved Lambda-doubling was observed in both fine-structure ladders. With the spectroscopic constants derived from the laboratory measurements, the spectra of all three can be calculated to an uncertainty of less than 0.1 km s(-1) in equivalent radial velocity over the entire range of interest to radio astronomers. SiCN, with a dipole moment of 2.9 D, is probably the most promising of the three for astronomical discovery.     

Thermal treatment as a method to control transfers of invasive biofouling species via vessel sea chests

This study examined the efficacy of heated seawater for the treatment and remediation of fouled vessel sea chest habitats. In laboratory trials, three temperature regimes (37.5°C for 60 min, 40°C for 30min and 42.5°C for 20 min) were tested on a range of temperate taxa commonly found in sea chests. Field validation trials further assessed the efficacy of heat treatment within a replica sea chest environment. During laboratory trials, 100% mortality was achieved across all three treatments for the majority of taxa; the exceptions being the barnacle Elminius modestus and the oyster Crassostrea gigas. Temperature tolerance limits observed in the laboratory were successfully replicated under simulated sea chest conditions; however, a failure to achieve even heat distribution was an obstacle to achieving uniform mortality. This study provides guidance on the temperature/exposure parameters required for vessels plying temperate latitudes, and demonstrates that heated seawater has potential for controlling biofouling in vessel sea chests.     

河北丰宁县大草坪钼矿区岩体锆石U-Pb年龄研究

大草坪钼矿属冀北上黄旗构造岩浆岩带钼多金属成矿带,对其赋矿围岩的年龄、矿床成因及类型一直存在争论。通过对岩浆结晶锆石及捕虏晶锆石U-Pb年龄研究,表明大草坪花岗岩岩浆结晶锆石U-Pb年龄为(220.0±1.7)Ma、(224.0±1.5)Ma和(232.7±1.5)Ma,作者据此重新厘定大草坪花岗岩成岩期为印支期,有别于1989年《河北省、北京市、天津市区域地质志》中厘定的燕山期。根据大草坪花岗闪长岩中岩浆结晶锆石U-Pb年龄(134.3±1.2)Ma和(140.0±1.5)Ma,重新厘定大草坪花岗闪长岩成岩期为燕山期,有别于前人厘定的海西期。表明本区含矿岩体来源于古老基底就地多期改造重熔。     

北京地区长城系

北京地区长城系是位于高于庄组之下、第变质基底岩系之上的一套地层。１）区内发育两层稳定的凝灰岩－－翠绿色层和棕红色层,可作为地层地对比的标志是;２）长城系底部的砂岩、页岩具穿时性,大红峪组存在明显的相变关系,不能只根据岩性进行分组。据此,把北京地区原长城系高于庄组之下地层重新厘定为大红峪组一段,包括原常州沟组、串岭沟组、团山子组和大红峪组一段;大红峪组二段即原大红峪组二段和大红峪组三段即原大红峪组三     

燕山西段及太行山区长城系底界的讨论

对燕山型长城系底部层位存在有不同的认识 ,从含钾盆地、大红峪海侵超覆、团山子组海进或海退的问题提出长城系底部地层属于大红峪组的观点。大红峪期时 ,燕山地区只存在一个含钾盆地 ,造成多层含钾页岩沉积 ,而串岭沟组不含钾。以前所划各组段的海侵超覆实为大红峪组的海侵超覆 ,是兴城运动在燕山西段的反映 ,其底部有明显的相变特征。由此把燕山西段及太行山区长城系底部层位重新划为大红峪组 ,则团山子组存在的不协调现象也就迎刃而解。同时还认为昌平德胜口剖面与青龙大杖子剖面几可逐层对比 ,阳原牛坊沟剖面与代表“青龙上升”的剖面相似 ,上述剖面应是大红峪海侵在燕山东西段的反映     

New approaches to the study of population dynamics in cities of Moscow Oblast

New approaches to the study of population growth, spatial distribution, and urbanization in the USSR are presented. "Quantitative analysis of historical trends in city growth rates within Moscow Oblast (1926-1984) reveals two major components or city types: a group of cities with below-(oblast) average rates for each of five periods of analysis (1926-39, 1939-59, 1959-70, 1970-79, 1979-84) and a second category experiencing above-average growth until 1970, with subsequent reduction of rates below the oblast average."