全文获取类型
收费全文 | 193篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 5篇 |
地球物理 | 58篇 |
地质学 | 40篇 |
海洋学 | 66篇 |
天文学 | 26篇 |
综合类 | 1篇 |
自然地理 | 3篇 |
出版年
2022年 | 2篇 |
2020年 | 6篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1981年 | 7篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1954年 | 1篇 |
1950年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有203条查询结果,搜索用时 31 毫秒
1.
ABSTRACTCharacterizing, understanding and better estimating uncertainties are key concerns for drawing robust conclusions when analyzing changing socio-hydrological systems. Here we suggest developing a perceptual model of uncertainty that is complementary to the perceptual model of the socio-hydrological system and we provide an example application to flood risk change analysis. Such a perceptual model aims to make all relevant uncertainty sources – and different perceptions thereof – explicit in a structured way. It is a first step to assessing uncertainty in system outcomes that can help to prioritize research efforts and to structure dialogue and communication about uncertainty in interdisciplinary work. 相似文献
2.
Experimental study on prevention of acid mine drainage by silica coating of pyrite waste rocks with amorphous silica solution 总被引:1,自引:1,他引:0
Masahiko Bessho Takaaki Wajima Takuro Ida Takashi Nishiyama 《Environmental Earth Sciences》2011,64(2):311-318
Acid mine drainage (AMD) is a widespread environmental problem associated with working and abandoned mining operations. It
results from the microbial oxidation of pyrite in the presence of water and air, affording an acidic solution that contains
toxic metal ions. Pyrite microencapsulation, utilizing silica coating, is a novel approach for controlling AMD that has been
shown to be very effective in controlling pyrite oxidation. The roles of the solution pH and silica concentration in the formation
mechanism for the AMD-preventing coating were investigated. A silica coating can be formed from silica solution at pH 7, at
which the amount of Fe eluted from pyrite into the solution is small. No coating was formed at other pH values, and the amounts
of eluted Fe were larger than at pH 7, especially at pH 11. The silica coating forms from 2,500 to 5,000 mg/L silica solutions,
but not from 0 or 1,000 mg/L silica solutions. The coating formation rate was slower in the 2,500 mg/L silica solution than
in the 5,000 mg/L silica solution. The formation of silica coating on pyrite surfaces depends on three main steps: formation
of Fe(OH)3 on the surface of pyrite, reaction between Fe(OH)3 and silicate in the solution on the pyrite surface, and growth of the silica layer on the first layer of silica. The best
pH condition to enable these steps was around 7, and the silica coating formation rate can be controlled by the concentration
of silica. 相似文献
3.
Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services
Kohei OGAWA Edward VERBREE Sisi ZLATANOVA Naohiko KOHTAKE Yoshiaki OHKAMI 《地球空间信息科学学报》2011,14(2):109-118
Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders. 相似文献
4.
Yoichiro Hanaoka Jun Nakazawa Osamu Ohgoe Yoshiaki Sakai Kazuo Shiota 《Solar physics》2014,289(7):2587-2599
White-light observations of the total solar eclipse on 13 November 2012 were made at two sites, where the totality occurred 35 min apart. The structure of the corona from the solar limb to a couple of solar radii was observed with a wide dynamic range and a high signal-to-noise ratio. An ongoing coronal mass ejection (CME) and a pre-CME loop structure just before the eruption were observed in the height range between 1?–?2 R⊙. The source region of CMEs was revealed to be in this height range, where the material and the magnetic field of CMEs were located before the eruption. This height range includes the gap between the extreme ultraviolet observations of the low corona and the spaceborne white-light observations of the high corona, but the eclipse observation shows that this height range is essential for the study of CME initiation. The eclipse observation is basically just a snapshot of CMEs, but it indicates the importance of a continuous coverage of CME observations in this height range in the future. 相似文献
5.
Priestley’s 1959 discussion concerning the estimations of momentum flux and of heat flux from profile observations of wind
and temperature, stating that the closeness of the curve fitting is deceptive, is first critically re-examined. Then a method
is proposed to estimate vertical flux of momentum and heat over the water surface, from the combined data of of wind speed
and temperature are assumed to have similar log-linear profiles, and the most probable profiles are determined by applying
the method of least squares simultaneously to wind and temperature data. Consequently, the most probable values of vertical
flux of momentum and heat may be estimated to satisfy as much as possible observed data of both wind and temperature simultaneously.
The coefficient of the linear term of the log-linear profile, which is treated as an indeterminate coefficient in this method,
may be determined from each observed data as a function of stability length. By tentatively applying the method to Rider’s
1954 data it is found that the coefficient shows a characteristic behavior with the stability length. 相似文献
6.
A method for the prediction of ocean waves was developed on the basis of the single-parameter growth equation of wind waves, proposed byToba (1978) on the basis of similarity in growing wind waves. The applicability of the method to actual problems was tested by hindcasting the wave characteristics with the method, for two cases with differing time and space scales, one in Kii Channel Approach, Japan, and the other in the North Atlantic Ocean. The results showed that the present method can predict waves within an error of 1.3 m in wave heights, which ranged from 3 to 12 m. 相似文献
7.
8.
This paper describes experiments on interfacial phenomena in a stratified shear flow having a sharp velocity shear at a density
interface. The interface was visualized in vertical cross-section using dye, and the flow pattern was traced using aluminum
powder. Two kinds of internal waves with different phase velocities and wave profiles were observed. They are here named p(positive)-waves
and n(negative)-waves, respectively. By means of a two-dimensional visualization technique, the following facts have been
confirmed regarding these waves. (1) The two kinds of waves propagate in the opposite direction relative to a system moving
with the mean velocity at the interface, and their dispersion relations approximately agree with the two solutions of interfacial
waves in a two-layer system of a linear basic shear flow. (2) The p-wave has sharp crests and flat troughs, and the n-wave
has the reverse of this. This difference in wave profile is due to the finite amplitude effect. (3) Phase velocity of each
wave lies within the range of the mean velocity profile, so that a critical layer exists and each wave has a “cat's eye” flow
pattern in the vicinity of the critical layer, when observed in a system moving with the phase velocity. Consequently, these
two waves are symmetrical with respect to the interface. The mechanisms of generation of these waves, and the entrainment
process are discussed. It is inferred that when the “cat's eye” flow pattern is distorted and a stagnation point approaches
the interface, entrainment in the form of a stretched wisp from the lower to the upper layer occurs for the p-wave, and from
the upper to the lower layer for the n-wave. 相似文献
9.
Mean monthly records of coastal sea surface temperature data (CSST) obtained from stations along the Japanese coasts of the Japan Sea and from those in the related seas for the period 1941–1984 were analyzed by using various methods of time series analysis, for the purpose of clarifying the nature of the year-to-year variations of the state of the Japan Sea. The year-to-year variations in the Japan Sea were found to be closely related to those in the East China Sea and in the western North Pacific. Specific results are as follows. (1) A sudden cooling in the early 1960's occurred in the southern stations of the Japan Sea and continued to the end of the analyzed data. (2) Variations, with about a 6-year periodicity, were observed at most stations, and were especially dominant in the southern stations of the Japan Sea (3) These variations could be traced back to the Kuroshio region of the East China Sea. (4) Variations, with about a 10-year periodicity, were also observed in the northern stations of the Japan Sea. 相似文献
10.
Historical GEK data provided by JODC is analyzed to investigate the characteristic variation in velocity of the Kuroshio, with special reference to the formation of small meanders south of Kyûshû. It is found that, during or prior to the period of small meander formation, there is a tendency for an abrupt increase in the current velocity west of Yaku-Shima (Yaku-Island), representing an increase in the main current intensity upstream. Also, there are apparent time lags in the variation in current velocity along the path of the Kuroshio between the upstream and the downstream regions of the small meander area. Namely, it is apparent that the increase in Kuroshio velocity in the Satsunan Strait procedes that offshore of Shikoku during the period of the small meander formation, by the order of one month. These results indicate that a nonlinear effect due to the increase in current velocity is a possible cause of the generation of small meanders. 相似文献