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21.
Simple monitoring method for precaution of landslides watching tilting and water contents on slopes surface 总被引:2,自引:2,他引:0
Taro Uchimura Ikuo Towhata Trinh Thi Lan Anh Jou Fukuda Carlos J. B. Bautista Lin Wang Ichiro Seko Taro Uchida Akira Matsuoka Yosuke Ito Yuichi Onda Sho Iwagami Min-Seok Kim Naoki Sakai 《Landslides》2010,7(3):351-357
A low-cost and simple monitoring method for early warning of landslides is proposed. To detect abnormal deformation of a slope, this method employs a tilt sensor in place of an extensometer on the slope surface. In order to examine the relevance of measuring rotation angle on a slope surface by tilt sensor, model tests were conducted, and rotation on the slope surface was observed together with slide displacement along the surface. The rotation data responded 30 min before failure in a model test, which could be useful as a signal for early warning. However, the behavior of rotation before failure varies from case to case, and thus, criteria to issue warning should be defined more carefully. For a model slope made of uniform loose sand, measurement of slide displacement along the slope surface is sensitive to failure at the toe, while the measurement of rotation on the slope surface is useful to detect the development of progressive failure upward along the slope. Wireless sensor units with microelectromechanical systems (MEMS) tilt sensor and volumetric water content sensor were also examined on a real slope in Kobe City, and a long-term monitoring was attempted. A simple but possible way to define the criteria of judgment to issue warning can be proposed based on combination of data obtained by the tilt sensors and volumetric water content sensors. 相似文献
22.
This paper aims to bridge the literatures of industrial districts and organizational networks by studying the development of organizational relationships in Taiwan's integrated circuit (IC) industry. Firms of the IC industry in Taiwan are highly concentrated in the Hsinchu Science-based Industrial Park (HSIP). They not only have contributed the most to the combined sales for the HSIP compared to other industries for half a decade, but also have made Taiwan the country with the fourth-largest IC industry in the world today. Along with the creation and maintenance of global competitiveness in this industry, the means of developing organizational relationships and geographical linkages are examined in this paper. The empirical findings are based on analysis of data regarding the organizational connections for Taiwan's IC industry during 1976 to 1996, collected at the individual firm level. It is found that a concurrent process of intensifying the internal as well as external linkages has occurred in the HSIP, a young high-tech region. It indicates that not only is the ``regional advantage' sufficiently sustained, but also the global industrial networks are continuously expanded to maintain the openness and dynamics of the region. 相似文献
23.
This paper examines the possibility of using superconducting gravimeter (SG) observations without a tilt compensation system. SG data obtained at Syowa Station, Antarctica, were recorded without tilt compensation from April 5, 2001 to January 4, 2002, however, tilt signals were registered during this time period. A tilt correction was applied to gravity data from August 2, 2001 to January 4, 2002. After the tilt correction, errors of tidal parameters were dramatically reduced and tidal parameters themselves almost coincide with those from the same length of tilt-controlled gravity data recorded in 2000, when tilt compensation system was used. The noise level of the thermal leveler in the seismic band was also investigated. Averaged power spectra of gravity from 15 quiet days each in 2000 and 2001 recorded with and without the tilt compensation system, respectively, were compared. ‘Quiet’ in this case, means very low earthquake activity and calm wind conditions. No significant difference in the seismic band, except at the frequency of 2 mHz, was noticed. The difference at 2 mHz occurred because of room temperature variations caused by the water cooler, which cools down a compressor by automatically switching on and off. 相似文献
24.
Algebra, in particular commutative algebra, is applied here to provide a general unified solution to nonlinear systems of equations encountered in geodesy. Starting with the “Abelian group”, the “polynomial ring” is defined and used to form generators of ideals. By applying Buchberger or polynomial resultant algorithms, these generators are reduced to simple structures often comprising a univariate polynomial in one of the unknowns. The advantage of the proposed unified approach is that it provides exact solutions to geodetic nonlinear systems of equations without the traditional requirements of linearization, iterations or approximate starting values. The commutative algebraic approach therefore alleviates the need for isolated exact solutions to various geodetic nonlinear systems of equations. The procedure is applied to GPS meteorology to compute refraction angles, and Helmert’s one-to-one mapping of topographical points onto the reference ellipsoid. 相似文献
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INTRODUCTIONWhiteSpotSyndromeVirus (WSSV)inPenaeuschinensisisthecausativeagentofaverysevereepizooticdiseasewhich,startingfrom 1 993 ,hadresultedinmorethan 80 %mortalitythroughoutshrimpculturefarmsinChina (Zhanetal.,1 995;1 998) .Now ,fiveyearslater,thevirusdiseaseissti… 相似文献
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Snowmelt and the hydrological interaction of forest–grassland ecosystems in Central Yakutia,eastern Siberia 下载免费PDF全文
M. L. Lopez Caceres F. Takakai G. Iwahana A. N. Fedorov Y. Iijima R. Hatano M. Fukuda 《水文研究》2015,29(14):3074-3083
In the last two decades the major focus of study in forest water and carbon balances in eastern Siberia has been on the effect of rain during the growing season. Little attention has been paid to the contribution of snowmelt water. The results of the present study indicate that weather conditions during the snowmelt period as well as the soil moisture conditions carried from the previous year's growing season strongly determined the water availability for the forest ecosystem at the beginning of the next growing season. In the forest–grassland intermingled ecosystem of lowland Central Yakutia, gradual snowmelt water flow from the forest into the adjacent grassland depressions increased when soil moisture was high and air temperature was low, whereas low soil moisture and high air temperatures accelerated soil thawing and consequently snowmelt water infiltration into the forest soil. We found that snow depth did not determine the volume of snowmelt water moving to the grassland depression since the thermokarst lake water level in the adjacent grassland was about 25 cm lower in 2005 than in May 2006, even though maximum snow depth reached 57 cm and 43 cm in the winter of 2004–05 and 2005–06, respectively. The contribution of snowmelt water to forest growth as well as the flow of water from the forest to the grasslands showed a strong annual variability. We conclude that warmer springs and high variability in precipitation regimes as a result of climate change will result in more snowmelt water infiltration into the forest soil when the previous year's precipitation is low while more snowmelt water will flow into the thermokarst lake when the previous year's precipitation is high. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
29.
Natural samples of typical cyclosilicates beryl and cordierite include water and carbon dioxide molecules in channels formed
by the open cavities. Water molecules in the channels have two forms that are distinguished by whether they coordinate to
extra-framework cations (type II) or not (type I). We measured polarized infrared (IR) spectra for thin sections of the (100)
plane of beryl or the (100) and (010) planes (cb and ca planes) of cordierite under various temperature conditions. The spectral features of major bands clearly showed the distinguishable
behavior of types I and II water molecules under high temperature as follows. Over the temperature range from room temperature
to 800°C where rapid dehydration did not occur, the decrease in band heights for type II water molecules were smaller than
those for type I, and band shifts were more predominant for type II water molecules. The decrease in band heights and band
shifts of type I/II bands differed also for beryl and cordierite, which arises from the different ways in which water molecules
are fixed in the channels. Dehydration was enhanced at 850°C. The IR spectra at room temperature quenched from 850°C both
for beryl and cordierite showed that the vibrational bands related to type II water molecules were stable after those related
to type I water molecules disappeared. In addition, frequency changes of type II bands were observed, possibly because of
changes of coordination states of type II water molecules to extra-framework cations in the channels. 相似文献
30.
Monthly gravity solutions of the Gravity Recovery and Climate Experiment (GRACE) reveal three areas in Antarctica with striking interannual mass trends. The positive mass trend in Enderby Land, East Antarctica, is poorly understood because of uncertainties in the surface ice-sheet mass balance, post-glacial rebound (PGR), and processing of GRACE data. In this study, we compare the GRACE mass trends with values estimated from in situ snow-stake measurements, and Ice Cloud and land Elevation Satellite (ICESat) data. The mass trends estimated from ICESat data show a strong correlation with GRACE mass trends. In contrast, the snow-stake data show discrepancies with temporal variations in GRACE mass, especially in 2006. The discrepancies are probably associated with basal ice-sheet outflow, which is difficult to observe using snow stakes. We conclude that the bulk of the GRACE mass trend can be explained by snow accumulation and basal ice-sheet outflow. 相似文献