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51.
The debate on scale in geography has yielded nuanced concepts that have enhanced scale analysis and methodologies for scale‐related research. Despite this advancement, questions still linger on the value of scale as a geographical vocabulary, partly because scalar analyses remain predicated on hierarchies, which have limited explanatory power. In this paper we draw on insight from political ecology to affirm and expand on the usefulness of scale for geographical inquiry and for engaging with contemporary people–environment relations. In particular, the paper appreciates that ecology is at the core of methodological questions pertaining to the explanation of these relations and is increasingly involved in the construction of biodiversity discourses and strategies that rely heavily on conceptions of, and pronouncements on, scale. We use the concept of scalar thickness as a way of thinking about how spaces of conservation are organized and the propensity of scales to coalesce at various stages of scale‐producing processes. We argue that wildlife management areas in Tanzania have played a pivotal role in the thickening of the micro scale in the southeast region. These areas constitute the scale at and though which global conservation agendas are implemented and natural resource rights and benefits are contested. 相似文献
52.
Fridolin Weber Peter O. Hess Benno Bodmann José de Freitas Pacheco Dimiter Hadjimichef Marcelo Netz-Marzola Geovane Naysinger Moisés Razeira César A. Zen Vasconcellos 《Astronomische Nachrichten》2024,345(2-3):e230148
This paper focuses on the implications of a commutative formulation that integrates branch-cutting cosmology, the Wheeler–DeWitt equation, and Hořava–Lifshitz quantum gravity. Building on a mini-superspace structure, we explore the impact of an inflaton-type scalar field on the wave function of the Universe. Specifically analyzing the dynamical solutions of branch-cut gravity within a mini-superspace framework, we emphasize the scalar field's influence on the evolution of the evolution of the wave function of the Universe. Our research unveils a helix-like function that characterizes a topologically foliated spacetime structure. The starting point is the Hořava–Lifshitz action, which depends on the scalar curvature of the branched Universe and its derivatives, with running coupling constants denoted as . The corresponding wave equations are derived and are resolved. The commutative quantum gravity approach preserves the diffeomorphism property of General Relativity, maintaining compatibility with the Arnowitt–Deser–Misner formalism. Additionally, we delve into a mini-superspace of variables, incorporating scalar-inflaton fields and exploring inflationary models, particularly chaotic and nonchaotic scenarios. We obtained solutions for the wave equations without recurring to numerical approximations. 相似文献
53.
Fridolin Weber Peter O. Hess Benno Bodmann José de Freitas Pacheco Dimiter Hadjimichef Marcelo Marzola Geovane Naysinger Moisés Razeira César A. Zen Vasconcellos 《Astronomische Nachrichten》2024,345(2-3):e230152
This article focuses on the implications of the recently developed commutative formulation based on branch-cutting cosmology, the Wheeler–DeWitt equation, and Hořava–Lifshitz quantum gravity. Assuming a mini-superspace of variables, we explore the impact of an inflaton-type scalar field on the dynamical equations that describe the trajectories evolution of the scale factor of the Universe, characterized by the dimensionless helix-like function . This scale factor characterizes a Riemannian foliated spacetime that topologically overcomes the big bang and big crunch singularities. Taking the Hořava–Lifshitz action as our starting point, which depends on the scalar curvature of the branched Universe and its derivatives, with running coupling constants denoted as , the commutative quantum gravity approach preserves the diffeomorphism property of General Relativity, maintaining compatibility with the Arnowitt–Deser–Misner formalism. We investigate both chaotic and nonchaotic inflationary scenarios, demonstrating the sensitivity of the branch-cut Universe's dynamics to initial conditions and parameterizations of primordial matter content. The results suggest a continuous connection of Riemann surfaces, overcoming primordial singularities and exhibiting diverse evolutionary behaviors, from big crunch to moderate acceleration. 相似文献
54.
Peter O. Hess Fridolin Weber Benno Bodmann José de Freitas Pacheco Dimiter Hadjimichef Marcelo Netz-Marzola Geovane Naysinger Moisés Razeira César A. Zen Vasconcellos 《Astronomische Nachrichten》2024,345(2-3):e230162
This article focuses on the implications of a noncommutative formulation of branch-cut quantum gravity. Based on a mini-superspace structure that obeys the noncommutative Poisson algebra, combined with the Wheeler–DeWitt equation and Hořava–Lifshitz quantum gravity, we explore the impact of a scalar field of the inflaton-type in the evolution of the Universe's wave function. Taking as a starting point the Hořava–Lifshitz action, which depends on the scalar curvature of the branched Universe and its derivatives, the corresponding wave equations are derived and solved. The noncommutative quantum gravity approach adopted preserves the diffeomorphism property of General Relativity, maintaining compatibility with the Arnowitt–Deser–Misner Formalism. In this work we delve deeper into a mini-superspace of noncommutative variables, incorporating scalar inflaton fields and exploring inflationary models, particularly chaotic and nonchaotic scenarios. We obtained solutions to the wave equations without resorting to numerical approximations. The results indicate that the noncommutative algebraic space captures low and high spacetime scales, driving the exponential acceleration of the Universe. 相似文献
55.
Models for the early Universe with the combined influence of scalar fields and vacuum polarization are discussed using phase plane portraints. The results concern the probability of the birth of the Universe, different de Sitter solutions and expressions for scalar perturbations. 相似文献
56.
全球化时代城市问题越来越多的以尺度问题的形式出现,尺度理论为分析城市发展背后的各种动力及其影响提供了新的视角。回归后,特区政府如何与位于不同尺度上的地域组织相互作用,进行尺度重组,是探究香港城市发展与管治的关键问题。本文考察广深港高速铁路香港段从项目构想、方案设计,到咨询及申请拨款的全过程,识别这个过程所涉及的不同尺度的作用者,分析他们的作用方式及作用结果。研究表明,回归后,特区政府主动向上尺度重组以拓展香港发展的腹地,政府间的制度性合作是其尺度重组的重要方式。同时,香港逐渐成长的市民社会是参与城市发展尺度重组的重要力量,地方行动者运用尺度政治从多个尺度建构话语和采取行动,对特区政府的方案进行抗议并引发整个社会的讨论。对香港的案例分析可加深对体制转型背景下地域组织尺度重组的认识,丰富尺度重组的理论内涵;也有助于国家客观地了解香港,为制定合理的政策提供科学依据。此外,内地市民社会逐步萌芽成长,案例中特区政府与香港市民社会互动的经验与教训可为内地政府提供借鉴。 相似文献
57.
Cynthia S. Gorman 《Geographical review》2019,109(4):487-506
Through legal interpretation of immigration categories, such as the refugee definition, signatories to the UN Refugee Convention restrict access to political asylum. This paper examines how scalar logics are used in legal interpretation to filter out particular people from national space and control the number legally entitled to enter and remain in the U.S. Scalar logics shape access by requiring asylum seekers to prove they have been ‘singled out’ for persecution and by steering the meaning of the ‘particular social group’ provision of the refugee definition. The restrictive effects of these scalar logics are analyzed in relation to case law involving Central American asylum seekers fleeing gang‐related violence. These cases are often rejected on the basis that the asylum seekers possess identities and experiences exceeding the limited protection offered by asylum. Through analysis of these scalar logics, the paper highlights how interpretations of the refugee definition are an ongoing site of struggle over the scope of asylum protection. 相似文献
58.
59.
A comparison and analysis of airborne gravimetry results from two strapdown inertial/DGPS systems 总被引:2,自引:0,他引:2
In September 1996 the University of Calgary tested a combination of strapdown inertial navigation systems and differential
global positioning system (DGPS) receivers for their suitability to determine gravity at aircraft flying altitudes. The purpose
of this test was to investigate the long-term accuracy and repeatability of the system, as well as its potential for geoid
and vertical gradient of gravity determination. The test took place during a 3-day period in the Canadian Rocky Mountains
over a single 100 × 100 km area which was flown with 10-km line spacing. Two flights were done at 4350 m in E–W and N–S profile
directions, respectively, and one at 7300 m with E–W profiles. Two strapdown inertial systems, the Honeywell LASEREF III and
the Litton-101 Flagship, were flown side by side. Comparison of the system estimates with an upward-continued reference showed
root-mean-square (RMS) agreement at the level of 3.5 mGal for 90- and 120-s filter lengths. The LASEREF III, however, performed
significantly better than the Litton 101 for shorter filtering periods of 30 and 60 s. A comparison between the two systems
results in an RMS agreement of 2.8 and 2.3 mGal for the 90- and 120-s filters. The better agreement between the two systems
is mainly due to the fact that the upward-continued reference has not been filtered identically to the system gravity disturbance
estimates. Additional low-frequency differences seem to point to an error in the upward-continued reference. Finally, an analysis
of crossover points between flight days for the LASEREF III shows a standard deviation of 1.6 mGal, which is near the noise
level of the INS and GPS data. Further improvements to the system are possible, and some ideas for future work are briefly
presented.
Received: 17 March 1998 / Accepted: 1 February 1999 相似文献
60.
P. Izquierdo C. Guedes Soares J. C. Nieto Borge G. R. Rodríguez 《Ocean Engineering》2004,31(17-18):2209-2225
Nautical radar and scalar buoy measurements of ocean wind generated waves have been analysed to compare the spectral parameters estimated from both sensors. The time series of different sea-state parameters and the differences and ratios of the values obtained from radar and buoy data using different analysis methods are compared. It has been observed that main differences between the sea-state parameters derived by using measurements obtained from both sensors result both from device characteristics and from the method of spectral estimation. In particular, it is shown that the Nyquist frequency has an important effect on the value of the sea-state parameters depending on spectral moments of order higher than zero. 相似文献