全文获取类型
收费全文 | 353篇 |
免费 | 21篇 |
国内免费 | 12篇 |
专业分类
测绘学 | 23篇 |
大气科学 | 53篇 |
地球物理 | 95篇 |
地质学 | 91篇 |
海洋学 | 81篇 |
天文学 | 20篇 |
综合类 | 8篇 |
自然地理 | 15篇 |
出版年
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 11篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 13篇 |
2014年 | 10篇 |
2013年 | 17篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 24篇 |
2007年 | 21篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 15篇 |
2003年 | 12篇 |
2002年 | 13篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1964年 | 2篇 |
1959年 | 2篇 |
1953年 | 1篇 |
1942年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有386条查询结果,搜索用时 15 毫秒
71.
A frequency response function change (FRFC) method to detect damage location and extent based on the change in the frequency response functions of a shear building under the effects of ground excitation was proposed in this paper. The damage identification equation was derived from the motion equations of the system before and after the occurrence of the damage. Efforts to make the FRFC method less model‐dependent were made. Intact system matrices, which could be estimated using the measured data without the need for an analytical model, and the frequency response functions were required for the FRFC method. The effects of measurement noise and model parameter error in the FRFC method were studied numerically. The proposed FRFC method was validated by experimental studies of a six‐story steel building structure with single and multiple damage cases. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
72.
A novel strategy to determine the insurance and risk control plan for natural disaster risk management 总被引:2,自引:2,他引:0
This study presents an extended framework for the analysis of economic effects of natural disaster risk management. It also attempts to define and evaluate the optimal insurance arrangements. A model, the economic utility constrained-maximization model, is proposed. The purpose of this study is to establish a strategy for determining an insurance and risk control plan in which consideration is given to balancing the economic effects (e.g., decrease in costs due to damage) by disaster mitigation. Furthermore, these values are compared with risk control actions for purposes of prioritization, to provide data to help evaluate the benefit of each risk control action. Disaster insurance policy premiums in contrast are based on actuarial data taken from situations in which risk control measures are not employed. This can make such contracts unfair to responsible enterprise managers who must take risk control measures. This represents an unfair aspect of insurance policies. Enterprise managers should be able to determine the optimum arrangement between natural disaster risk control and insurance given their budget limitations. The optimal strategies aim at the best applicability and balance between risk control and insurance capability for the enterprise manager. Risk control measures can generate several risk control options for enterprise managers. Premium discounts by insurers are given in this model. 相似文献
73.
Cheng-Wu Chen Kevin Fong-Rey Liu Chun-Pin Tseng Wen-Ko Hsu Wei-Ling Chiang 《Natural Hazards》2012,64(2):1707-1716
Elicitation methods are used in decision making with respect to risk hazards to allow a researcher to infer the subjective utilities of outcomes from the observed preferences of an individual. A questionnaire method is presented, in this study, which takes into account the inevitable distortion of preferences by random errors and minimizes the effect of such errors. Under mild assumptions, the method for eliciting the utilities of many outcomes is a three-stage procedure. First, the questionnaire is utilized to elicit responses from which a subjective score is defined. Second, individual risk factors are discussed. Finally, the regression model presents individual risk preferences given the overall organizational risk culture, risk management policy, risk identification, and risk analysis. This paper addresses how company managers face risk and their tolerance of risk with respect to risk management. 相似文献
74.
Risk and uncertainty analysis in the planning stages of a risk decision-making process 总被引:7,自引:6,他引:1
Natural disaster risk, a long-time concern in the insurance industry, is increasingly recognized as a present danger in the
business strategies of risk control and enterprise management agencies. Floods and earthquakes can cause massive loss of life
and infrastructure, resulting in business interruption and heavy casualties. Many of the short-term developmental strategies
employed throughout the world have only served to exacerbate the impact of natural disasters. Therefore, this study presents
a review of formal methods that are commonly used in risk and uncertainty analysis in planning and concludes with a critical
assessment of the advantages and disadvantages of the different priority setting methods. Our focus is a preliminary proposal
for developing an efficient probabilistic approach to facilitate design optimization that involves probabilistic constraints. 相似文献
75.
H. Allen Hu S. H. Chen C. W. Hsu C. Wang C. L. Wu 《International Journal of Environmental Science and Technology》2012,9(2):343-354
A new business model, product service systems, is proposed to promote a shift in focus from selling purely products to selling functions. This is achieved through a mix of products and services that fulfill the same consumer demands, while eliciting less environmental impact. Development of product service systems has become an increasingly important strategy in achieving social, economic, and environmental sustainability because product service systems advocates reducing resource consumption, while delivering better and more widely available goods and services. This paper proposes an evaluation framework of sustainable performance to implement product service systems. A literature review discusses 32 criteria categorized into two aspects: product and organization. The fuzzy Delphi method is then applied to identify the consistency of criteria. The relative weights of the selected criteria are determined using Fuzzy analytic hierarchy process. Results indicate that the top three criteria in product aspect are maintenance system (weight?=?0.172), use time or frequency (weight?=?0.145), and price of the product (weight?=?0.132). For the organization aspect, the top three criteria are integrated service plan (weight?=?0.197), product development and design (weight?=?0.144) and optimized transportation network (weight?=?0.089). The demand for implementing product service systems is completely different from selling traditional goods because product service systems must consider the issue of sustainability. The proposed evaluation framework can help companies identify the potential products suitable in implementing product service systems. 相似文献
76.
The loss of beach sand from berm and dune due to high waves and surge is a universal phenomenon associated with sporadic storm activities. To protect the development in a coastal hazard zone, hard structures or coastal setback have been established in many countries around the world. In this paper, the requirement of a storm beach buffer, being a lesser extent landward comparing with the coastal setback to ensure the safety of infrastructures, is numerically assessed using the SBEACH model for three categories of wave conditions in terms of storm return period, median sand grain size, berm width, and design water level. Two of the key outputs from the numerical calculations, berm retreat and bar formation offshore, are then analysed, as well as beach profile change. After having performed a series of numerical studies on selected large wave tank (LWT) test results with monochromatic waves using SBEACH, we may conclude that: (1) Berm erosion increases and submerged bar develops further offshore as the storm return period increases for beach with a specific sand grain size, or as the sand grain reduces on a beach under the action of identical wave condition; (2) Higher storm waves yield a large bar to form quicker and subsequently cause wave breaking on the bar crest, which can reduce the wave energy and limit the extent of the eroding berm; (3) A larger buffer width is required for a beach comprising small sand grain, in order to effectively absorb storm wave energy; and (4) Empirical relationships can be tentatively proposed to estimate the storm beach buffer width, from the input of wave conditions and sediment grain size. These results would benefit a beach nourishment project for shore protection or design of a recreational beach. 相似文献
77.
A rectangular flume with dimensions of length 180 cm, height 60 cm and width 20 cm was used to observe the entry angle (i.e. angle between the interface and the centerline of the slot) of a two-layer flow withdrawal by a line sink. Saline water was used to form a bottom density current and red dye was applied. Based on the experimental data, one could see that the dimensionless discharge is more influential on the entry angle than the depth-averaged concentration of the lower-layer flow. Thus, the influence of concentration on experimental conditions is negligible for evaluation of the entry angle. The absolute values of entry angles increase with the absolute values of the dimensionless discharge. Almost all absolute values of the theoretical angle are bigger than that of the measured angle with a deviation bounded within 0.15 rad. The influence on the entry angle from the dimensionless discharge is symmetrical between the drawdown curve (interface above the slot) and the suck-up curve (interface below the slot). This phenomenon can be seen from a simplified form of a theoretical formula. 相似文献
78.
Nien-Sheng Hsu Wei-Chen Cheng Wen-Ming Cheng Chih-Chiang Wei William W.-G. Yeh 《Advances in water resources》2008
This paper develops an iterative procedure for capacity expansion studies for water distribution systems. We propose a methodology to analyze an existing water distribution system and identify the potential bottlenecks in the system. Based on the results, capacity expansion alternatives are proposed and evaluated for improving the efficiency of water supply. The methodology includes a network flow based optimization model, four evaluation indices, and a series of evaluation steps. We first use a directed graph to configure the water distribution system into a network. The network flow based model optimizes the water distribution in the system so that different expansion alternatives can be evaluated on a comparable basis. This model lends itself to linear programming (LP) and can be easily solved by a standard LP code. The results from the evaluation tool help to identify the bottlenecks in the water distribution system and provide capacity expansion alternatives. A useful complementary tool for decision making is composed of a series of evaluation steps with the bottleneck findings, capacity expansion alternatives, and the evaluation of results. We apply the proposed methodology to the Tou-Qian River Basin, located in the northern region of Taiwan, to demonstrate its applicability in optimization and capacity expansion studies. 相似文献
79.
Dam overtopping risk assessment considering inspection program 总被引:3,自引:2,他引:1
Jan-Tai Kuo Yung-Chia Hsu Yeou-Koung Tung Keh-Chia Yeh Jian-De Wu 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(3):303-313
Safety inspection of large dams in Taiwan is conducted every 5 years. The practice does not take into consideration uncertainty
of dam conditions. The goal of this study is to determine the optimal dam inspection interval under the consideration of overtopping
risk incorporating uncertainty gate availability. In earlier studies, assessment of overtopping risk only considered the uncertainties
in reservoir properties and natural randomness of hydrologic events without giving much thought to the availability of spillway
gates. As a result, the overtopping risk could be underestimated. In this study, an innovative concept is proposed to evaluate
dam overtopping by taking into account spillway gate availability. The framework consists of three parts: (1) evaluation of
conditional overtopping risk for different numbers of malfunctioning spillway gates; (2) evaluation of spillway gate availability;
and (3) dam inspection scheduling. Furthermore, considerations are given to overtopping risk, inspection cost, and dam break
cost for determining the optimal inspection schedule. The methodology is applied to the Shihmen Reservoir in Taiwan and to
evaluate its time-dependent overtopping risk. Results show that overtopping risk considering the availability of the spillway
gates is higher than the one without considering the availability of the spillway gates. 相似文献
80.
Since the beginning of formation of Proto-Taiwan, the subducting Philippine (PH) Sea plate has moved continuously through
time in the N307° direction with respect to Eurasia (EU), tearing the EU plate. The subducting EU plate includes a continental
part in the north and an oceanic part in the south. The boundary B between these two domains corresponds to the eastern prolongation
of the northeastern South China Sea ocean-continent transition zone. In the Huatung Basin (east of Taiwan), the Taitung Canyon
is N065° oriented and is close and parallel to B. Seismic profiles show that the southern flank of the canyon corresponds
to a fault with a normal component of a few tens of meters in the sediments and possible dextral shearing. Several crustal
earthquakes of magnitude >%6 are located beneath the trend of the Taitung Canyon and focal mechanisms suggest that the motion
is right-lateral. Thus, faulting within the sedimentary sequence beneath the Taitung Canyon is a consequence of underlying
dextral strike-slip crustal motions. As the continental part of the EU slab located north of B has been recently detached,
some subsequent dextral strike-slip motion might be expected within the EU slab, along the ocean-continent transition zone,
which is a potential zone of weakness. We suggest that the dextral strike-slip motion along the ocean-continent boundary of
the EU slab might trigger the observed dextral strike-slip motion within the overlying PH Sea crust and the associated faulting
within the sediments of the Huatung Basin, beneath the Taitung Canyon.
An erratum to this article is available at . 相似文献