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1.
尽管片山内阁是一短命的中道政权,但是若从占领时期日本政府构筑安全保障体制的角度而言,则是一不容忽视的时期。在这一时期,片山内阁不仅提出了一系列的媾和对策文件,更重要的是采取行动将日本安全保障方面的设想通过一切可能的渠道向美国方面转达,相继提出了《芦田备忘录》、《铃木备忘录》以及《天皇口信》,形成了后来的日美安全保障体制的原型。  相似文献   

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Simultaneous observations by EISCAT and an HF Doppler system of a TID are presented. Crossspectral analysis of the data allows the vertical variation of the neutral temperature and horizontal wind in the thermosphere to be determined.  相似文献   

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The stratospheric volcanic cloud from the eruption.of El Chichon, Mexico, on 4 April 1982 was observed routinely by a Nd: YAG lidar system from 18 April 1982 at Kyushu University, Fukuoka, Japan. The observed layers of the cloud above 20 km were in the easterly wind region and those below 20 km were in the westerly region. The main part of the cloud mass was in the upper layer. This upper layer broadened slowly until September 1982, then broadened rapidly and merged with the lower layer as the easterly wind changed to the westerly wind. The vertical eddy diffusion coefficient estimated from the broadening of the upper layer was much smaller than the value usually used in the one-dimensional model calculation of chemical components until September and subsequently remained at about the same value. The increase of the integrated backscattering coefficient (IBC) was about two orders of magnitude larger than the largest increase after volcanic injections for the last 10 years. The IBC reached a maximum value on 3 May and gradually decreased until August 1982, then re-increased until December 1982. The IBC between December 1982 and February 1983 was about the same value as in May 1982. Using the one-dimensional stratospheric sulfate aerosol model simulations it was concluded that to explain the broadening of the upper layer an eddy diffusion coefficient of about 102cm2s-1 would be needed in the easterly wind region in summer. It was also concluded that the IBC re-increase was caused after advective horizontal transport from lower to higher latitudes by chemical reactions within the upper layer without meridional diffusion during summer and that the transport was controlled by nucleation, which gives rise to small particles, a decreasing settling velocity of the volcanic cloud and then the cloud being less affected by horizontal transport.  相似文献   

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Temperature and wind behavior observed during the February 1979 solar eclipse shows significant change immediately following and up to one hour after totality. Statospheric and mesospheric data obtained from Fort Churchill, Manitoba, indicate quite clearly a cooling trend between 50–60 kilometers with the maximum temperature decrease of approximately 10°C evident above 52 kilometers. This temperature perturbation was accompanied by an amplification of the meridional wind speed of 20–30 mps near 60 kilometers. These results are essentially in agreement with those obtained at Wallops Island during the March 1970 solar eclipse. Although the stratosphere was under the large-scale influence of a stratospheric warming, the short-term perturbations caused by radiative changes as a result of the solar eclipse did not appear to be masked.  相似文献   

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The history of cerebral trauma is a large subject and this overview is an attempt to summarise the main trends of understanding and management over the millenia. Although beginning with anthropological evidence, papyrology and Homeric times, the main impetus for its scientific study began with Hippocrates, but little progress was made until the Salernitan period. Because the ancients believed it was the fractured bone and not the underlying neurological status that mattered, and determined whether an operation was to be performed, the classification of head injuries was based on the types of skull fracture and not the underlying neurological damage. Only in recent centuries was it realised that it was not skull fractures that were important but the brain lesion. Further improvement in management occurred during warring periods but the lessons learned were not passed on, although mortality from military wounds has steadily declined. Since only a small percentage of head injuries require surgery, consideration should be given to reserve the time and skills of the neurosurgeon to those cases requiring his expertise; this would require that the preliminary care should be undertaken by physicians with a specific interest in this field.  相似文献   

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Abstract

A significant proportion of the literature on the reburial of archaeological sites concerns mosaics. These publications reveal that a variety of materials have been used for mosaic reburial, including specialized fill and separation layers, from the early 1980s onwards. Although reburial practice often demonstrates an ad hoc and indiscriminate use of fill and separation materials, or the following of trends and anecdotal information favouring certain materials, knowledge of their characteristics is very important in developing an appropriate technical design for reburial of mosaics. The materials most commonly employed in mosaic reburial practice, including geotextiles, are reviewed and an assessment of their positive and negative characteristics within a reburial design is provided. Recent but limited laboratory and field testing, monitoring and evaluation of reburial interventions have begun to provide preliminary evidence about the behaviour of these materials, indicating which ones are most appropriate and how they should be utilized to best advantage. However, their selection and use remains uneven, and positive results continue to be as much a function of adequate maintenance as proper design and execution.  相似文献   

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刘颖 《安徽史学》2005,4(1):12-16
20世纪初英国逐步建立了现代社会保障制度.贫困和失业等社会问题的严重化和济贫法制度的失效是这一制度建立的根本原因;来自工人阶级的政治压力是其建立的一个重要原因;费边社会主义、集体主义和新自由主义为这一制度的建立提供了理论基础;德国保险型社会保障制度的建立起了先导作用.英国政府通过一系列的社会立法逐步形成了涉及到养老、失业、医疗、儿童等方面比较完善的福利体系,标志着英国现代社会保障制度的初步确立.它是英国社会保障制度史上一次根本性的转折.  相似文献   

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Exchange and interaction between early state-level societies in Mesopotamia and the Indus Valley during the 3rd millennium BC has been documented for some time. The study of this interaction has been dominated by the analysis of artifacts such as carnelian beads and marine shell, along with limited textual evidence. With the aid of strontium, carbon, and oxygen isotopes, it is now possible to develop more direct means for determining the presence of non-local people in both regions. This preliminary study of tooth enamel from individuals buried at Harappa and at the Royal Cemetery of Ur, indicates that it should be feasible to identify Harappans in Mesopotamia. It is also possible to examine the mobility of individuals from communities within the greater Indus Valley region.  相似文献   

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A second series of long term mesospheric and lower thermospheric wind observations was conducted at Arecibo (18.4°N, 66.8°W) between 6 and 20 March 1981 using the UHF Doppler radar, following the first observations in August 1980 (Hirota et al., 1983). Zonal and meridional wind velocities were measured during the morning (8–10 LT) and afternoon (13–15 LT) periods. The mean wind profile averaged over the entire observational period shows the predominance of the diurnal tide. The fluctuating wind vector rotates clockwise relative to height with a characteristic vertical scale of about 10 km. The phase difference inferred by a cross correlation analysis between morning and afternoon profiles indicates that the dominant period is about 20–30 h. This oscillation is discussed in relation to internal inertia-gravity waves observed by the same radar in the lower stratosphere. On the other hand, wind fluctuation with a vertical scale larger than 20 km shows a substantial day-to-day variation with a period of 5–8 days. This long period oscillation shows a good correlation with the global scale geopotential height anomalies at 1 mb (46–48 km) observed by the Tiros-N satellite at 20°N. Our evidence suggests that westward travelling planetary-scale waves with zonal wavenumber one may propagate up to the lower thermosphere.  相似文献   

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We have carried out continuous observations of the tropopause region over Japan for three weeks during the Baiu (early summer rain “in Japan”) season in 1991, by using a VHF Doppler radar (the MU radar), radiosondes launched at the radar site and operational rawinsondes at five meteorological stations. Based on these observations, we try to examine the hypothesis that the multiple tropopauses and the dominant inertio-gravity waves are one and the same feature, and obtain some interesting results that are not inconsistent with this hypothesis. First, vertical wavenumber spectra and hodographs analyzed from the radar wind data in the tropopause region suggest that inertio-gravity waves with vertical wavelengths of ∼ 2 km are quasi-monochromatically dominant (with 2–3 day scale variabilities of 10–20%), and are in accordance with activities of the subtropical jet stream and mesoscale cyclone-front system activities observed by the operational network. Second, striking (potential) temperature fluctuations are detected simultaneously by the radiosondes and rawinsondes, which appear as multiple tropopauses in meridional cross-section analysis. Third, vertical wavenumber spectra analyzed from the radiosonde temperature data are consistent with the radar wind spectrum, if we assume that both wind and temperature fluctuations are mainly induced by the dominant inertio-gravity waves. Finally, we confirm that the dominant interio-gravity waves can be barely detected also from routine rawinsonde (1.5-km running-mean) wind data if the amplitude is larger than 1.5 m/s. However, the monochromatic wave structures are generally quite localized in space and time.  相似文献   

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Regime theory provides a framework for exploring changes in development patterns and internal dynamics of growth coalitions. Academic debates on sport and urban development have focused on large American and European markets, where such venues are increasingly led by urban regimes that aim to leverage public goals through private investment. Based on a detailed qualitative analysis of four projects in three major Israeli cities, this work examines a different typology of sport venue development – ‘public regime’, which operates in a small market context. The Israeli public regime neither allows the private sector to assume central roles in the design, development and operation of venues nor does it stimulate real estate development anchored by the venue. The assumption that professional sports is not a viable business in small markets is used to justify the public monopoly that regards the venues as public amenities, legitimizing the lack of strategic and business plans, producing benefits for the local political elite but doing little to stabilize professional sport and secure economic returns for the public. The more affluent city of Tel Aviv demonstrates a breakout from a pure public regime, where public control is retained but more business-oriented considerations are incorporated.  相似文献   

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Irregular winds of the middle atmosphere, commonly attributed to gravity waves, often exhibit a vertical-wavenumber (m) spectral form approximating to Km−3 at sufficiently large m, with K a constant found to be relatively unvarying with time, location and even height. This behavior is widely believed to result from some saturation process, but the physical mechanism remains a matter for debate. There now exist three theories:
  • 1.(a) linear instability,
  • 2.(b) nonlinear wave-induced diffusion, and
  • 3.(c) nonlinear waveinduced Doppler spreading. Each has produced the Km−3 form (but only as an approximation in the case of Doppler spreading) and values of K within a factor of three of one another and of observed values.
New data have revealed circumstances in which an approximation to the form Km−3 is again found, suggestive of saturation, but with values of K that increase by a factor of 5 or 10 on moving from the stratopause to the mesopause region. This height variation is incompatible with theories (a) and (b) if the m−3 form is taken to be induced by the corresponding saturation process (rather than by source spectra), but is shown here to be compatible with the Doppler-spread theory. Because of the continued growth of K with height, which must ultimately cease, the observations and corresponding theory are taken to represent pseudosaturation rather than fully developed saturation per se.  相似文献   

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Irrigated agriculture was central to the economies of many of the world’s best known complex societies. New high-resolution digital elevation models (DEM) derived from remotely sensed lidar data give archaeologists the opportunity to study field systems at a scale not previously possible. Here we describe a method called slope contrast mapping that takes advantage of the dissimilarity between artificial and natural slopes to identify and map discrete features. We use this relatively simple method in our own research to identify complexes of agricultural terraces in the North Kohala district, Hawai’i Island. It has also proved useful for mapping the natural landscape, specifically the extent of flat land between valleys suited for irrigated agriculture.  相似文献   

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This paper reports the combined preliminary results of the Italian Mission to Kassala and the joint University of Khartoum/Southern Methodist University Butana Project. Both groups have been carrying out extensive survey and test excavations in the Southern Atbai of the East Central Sudan, between the Atbara and Gash Rivers. This work has led to the recognition of a previously unknown culture area and ceramic tradition which spans about 5000 years and, at its peak, probably covered about 100,000 sq. km east of the Nile. This ceramic tradition, the Atbai Tradition, is associated with the development of large villages (over 10 ha) during the 4th millennium bc.
Résumé Le présent article rapporte les résultats préliminaires combinés de la Mission italienne à Kassala et du projet Butana entrepris en commun par les universités de Khartoum et Southern Methodist. Ces deux groupes ont réalisé des reconnaissances archéologiques extensives et des sondages dans le sud de l'Atbai, dans la partie centrale orientale du Soudan, entre les rivières Atbara et Gash. Leur travail a mené à la reconnaissance d'une civilisation et d'une tradition céramique auparavant inconnues qui durèrent quelque 5000 ans et qui couvraient à leur apogée environ 100,000 km2 à l'est du Nil. Cette tradition céramique, la tradition Atbai, est associée au développement des grands villages (de plus de 10 ha) au cours du 4e millénaire avant notre ère.
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