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941.
本文介绍了对3根在实验室、1根野外装有应变仪的灌浆锚杆进行的试验。考虑到长期可靠性、稳定性和准确性,采用两种表面安装的振动钢丝绳应变仪焊在锚杆上。在实验室对应变仪性能、载荷传递机理、脱粘附过程、蠕变过程性能、以及在加、卸载和持续载荷下锚杆的长期性能作了研究。加拿大的Jeffrey矿对一根应变仪的灌浆锚杆进行了实际应用试验。结果表明,采用这种装备技术对长期监测灌浆锚杆上工作情况非常有效。 相似文献
942.
印度尼西亚伊里安查亚中西部的 Ertsberg地区位于新几内亚岛中央山脉中,距阿拉弗拉海120km.本区的矿床为新几内亚地区主要的Au±Cu矿床,包括多组矿体,与这些矿体相伴的是侵入于中-新生代沉积序列的年龄为4~2.5 Ma的过渡成分侵入体 相似文献
943.
HelmutA.Abt 《天文学进展》1998,(2)
科学期刊的出版和发行技术正在迅速变化.主要对Ap.J.如何使用电子投稿方式及该杂志的网上版作了介绍.同时也叙述了较快的审稿及非常快速的出版等方面的进展。 相似文献
944.
对利用氖同位素体系标定地幔柱的新方法进行评述,介绍Matsumotot等在澳大利亚用磷灰石中地幔派生矿物的流体包裹体氖同位素组成研究地幔柱的方法原理及成果,并指责该方法的不足之处。这对于促进有关地幔柱的地球化学示踪剂的研究很有指导意义。 相似文献
945.
本文利用电流不稳定性线性理论讨论了1992年6月25日至26日耀斑后环中出现不均匀“结”状结构(“knot”或“blob”)的可能性,并且在同时考虑重力、磁力和环顶物质下落初速的情况下,理论计算了1992年6月26日Hα耀斑后环物质运动的规律。理论计算与观测求得的视向速度随高度分布的曲线基本符合。 相似文献
946.
Linkin V Harri AM Lipatov A Belostotskaja K Derbunovich B Ekonomov A Khloustova L Kremnev R Makarov V Martinov B Nenarokov D Prostov M Pustovalov A Shustko G Jarvinen I Kivilinna H Korpela S Kumpulainen K Lehto A Pellinen R Pirjola R Riihela P Salminen A Schmidt W McKay CP 《Planetary and Space Science》1998,46(6-7):717-737
A mission to Mars including two Small Stations, two Penetrators and an Orbiter was launched at Baikonur, Kazakhstan, on 16 November 1996. This was called the Mars-96 mission. The Small Stations were expected to land in September 1997 (Ls approximately 178 degrees), nominally to Amazonis-Arcadia region on locations (33 N, 169.4 W) and (37.6 N, 161.9 W). The fourth stage of the Mars-96 launcher malfunctioned and hence the mission was lost. However, the state of the art concept of the Small Station can be applied to future Martian lander missions. Also, from the manufacturing and performance point of view, the Mars-96 Small Station could be built as such at low cost, and be fairly easily accommodated on almost any forthcoming Martian mission. This is primarily due to the very simple interface between the Small Station and the spacecraft. The Small Station is a sophisticated piece of equipment. With the total available power of approximately 400 mW the Station successfully supports an ambitious scientific program. The Station accommodates a panoramic camera, an alpha-proton-x-ray spectrometer, a seismometer, a magnetometer, an oxidant instrument, equipment for meteorological observations, and sensors for atmospheric measurement during the descent phase, including images taken by a descent phase camera. The total mass of the Small Station with payload on the Martian surface, including the airbags, is only 32 kg. Lander observations on the surface of Mars combined with data from Orbiter instruments will shed light on the contemporary Mars and its evolution. As in the Mars-96 mission, specific science goals could be exploration of the interior and surface of Mars, investigation of the structure and dynamics of the atmosphere, the role of water and other materials containing volatiles and in situ studies of the atmospheric boundary layer processes. To achieve the scientific goals of the mission the lander should carry a versatile set of instruments. The Small Station accommodates devices for atmospheric measurements, geophysical and geochemical studies of the Martian surface and interior, and cameras for descent phase and panoramic views. These instruments would be able to contribute remarkably to the process of solving some of the scientific puzzles of Mars. 相似文献
947.
Hodge J Longstaff B Steven A Thornton P Ellis P McKelvie I 《Marine pollution bulletin》2005,51(1-4):113-118
We present an overview of a portable underway water quality monitoring system (RUM-Rapid Underway Monitoring), developed by integrating several off-the-shelf water quality instruments to provide rapid, comprehensive, and spatially referenced 'snapshots' of water quality conditions. We demonstrate the utility of the system from studies in the Northern Great Barrier Reef (Daintree River) and the Moreton Bay region. The Brisbane dataset highlights RUM's utility in characterising plumes as well as its ability to identify the smaller scale structure of large areas. RUM is shown to be particularly useful when measuring indicators with large small-scale variability such as turbidity and chlorophyll-a. Additionally, the Daintree dataset shows the ability to integrate other technologies, resulting in a more comprehensive analysis, whilst sampling offshore highlights some of the analytical issues required for sampling low concentration data. RUM is a low cost, highly flexible solution that can be modified for use in any water type, on most vessels and is only limited by the available monitoring technologies. 相似文献
948.
Nitrogen loading to aquatic ecosystems from sewage is recognised worldwide as a growing problem. The use of nitrogen stable isotopes as a means of discerning sewage nitrogen in the environment has been used annually by the Ecosystem Health Monitoring Program in Moreton Bay (Australia) since 1997 when the technique was first developed. This ("sewage plume mapping") technique, which measures the delta(15)N isotopic signature of the red macroalga Catenella nipae after incubation in situ, has demonstrated a large reduction in the magnitude and spatial extent of sewage nitrogen within Moreton Bay over the past 5 years. This observed reduction coincides with considerable upgrades to the nitrogen removal efficacy at several sewage treatment plants within the region. This paper describes the observed changes and evaluates whether they can be attributed to the treatment upgrades. 相似文献
949.
Bioavailability of dissolved organic phosphorus compounds to typical harmful dinoflagellate Prorocentrum donghaiense Lu 总被引:4,自引:0,他引:4
The bioavailability of dissolved organic phosphorus (DOP) compounds to harmful alga Prorocentrum donghaiense Lu and its alkaline phosphatase activity (APA) were studied. Results showed that P. donghaiense could utilize the test DOP compounds such as glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP) and ribonucleic acid (RNA) to sustain its growth. Nutrition between the test DOP compounds and orthophosphate was comparable. P. donghaiense could utilize intracellular phosphorus to sustain growth under depletion of dissolved phosphorus. Variation of APA in different test DOP compounds was addressed; the controlling mechanism of APA in different DOP media was discussed. 相似文献
950.
Downs CA Fauth JE Robinson CE Curry R Lanzendorf B Halas JC Halas J Woodley CM 《Marine pollution bulletin》2005,51(5-7):558-569
Coral reefs within the Florida Keys are disappearing at an alarming rate. Coral cover in the Florida Keys National Marine Sanctuary declined by 38% from 1996 to 2000. In 2000, populations of Montastraea annularis at four sites near Molasses Reef within the Florida Keys National Marine Sanctuary and one reef within Biscayne National Park were sampled on a quarterly basis. Anecdotal observations showed corals at Alina's Reef in Biscayne National Park appeared healthy in March, but experienced an acute loss of coral cover by August. Cellular Diagnostic analysis indicated that Alina's Reef corals were in distress: they had been afflicted with a severe oxidative damaging and protein-denaturing stress that affected both the corals and their symbiotic zooxanthellae. This condition was associated with a significant xenobiotic detoxification response in both species, reflecting probable chemical contaminant exposure. These results demonstrate that applying a Cellular Diagnostic approach can be effective in helping to identify stress and its underlying causes, providing diagnostic and prognostic biomarkers of coral health. 相似文献