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71.
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
72.
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
73.
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
74.
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
75.
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
76.
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
77.
大量的数值模拟表明,SVD和LSQRD在面波频散网格反演两步法中的应用效果都很好.但SVD可以用分辨矩阵、信息矩阵和协方差矩阵对解估计进行数学上客观有效的评价;而对于大型稀疏方程组的求解,LSQRD确是一种内存需求小、计算速度快以及分辨抗噪能力都较强的算法 .在现有计算机运算速度较快、内存可以扩充较大的条件下,实测数据量不很大时,应采用SVD算法进行线性反演. 相似文献
78.
This study measures the reaction rate of dolomite and aragonite (calcite) into Mg-calcite at 800, 850, and 900°C and 1.6 GPa. The dry synthetic dolomite-aragonite aggregate transformed very rapidly into dolomite-calcite polycrystalline aggregate while Mg-calcites formed at a relatively slow rate, becoming progressively richer in Mg with run time. We modeled the reaction progress semi-empirically by the first-order rate law. The temperature dependence of the overall transport rate of MgCO3 into calcite can be described by the kinetic parameters (E?=?231.7 kJ/mol and A o ?=?22.69 h?1). Extrapolation using the Arrhenius equation to the conditions during exhumation of UHPM rocks indicates that the reaction of dolomite with aragonite into Mg-saturated calcite can be completed as the P-T path enters the Mg-calcite stability field in a geologically short time period (<1 Ky). On the other hand, the extrapolation of the rate to prograde metamorphic conditions reveals that the Mg-calcite formed from dolomitic marble in the absence of metamorphic fluid may not reach Mg-saturation until temperatures corresponding to high-grade metamorphism (e.g., >340°C and >10 My). SEM-EDS analysis of individual calcite grains shows compositional gradients of Mg in the calcite grains. The Mg-Ca inter-diffusion coefficient at 850°C is around 1.68?×?10?14 m2/sec if diffusion is the major control of the reaction. The calculated closure temperatures for Ca-Mg inter-diffusion as a function of cooling rate and grain size reveal that Ca/Mg resetting in calcite in a dry polycrystalline carbonate aggregate (with grain size around 1 mm) may not occur at temperatures below 480°C at a geological cooling rate around 10°C/My, unless other processes, such as short-circuit interdiffusion along grain boundaries and dislocations, are involved. 相似文献
79.
L. C. Hsu 《Contributions to Mineralogy and Petrology》1980,71(4):407-415
The phase relations in the system grossular-spessartine-H2O were investigated at 2.0 Kb aqueous fluid pressure and at subsolidus temperatures down to 420 ° C. Despite metastable persistence of a compositional gap found in some intermediate members, a complete solid solution between grossular and spessartine exists.Linear relations between the unit cell edge, a
0, and composition were readily observed down to 620 ° C with a
0=11.849(2) Å and 11.613(2) Å for grossular and spessartine, respectively. Hydrated garnets began to appear at higher temperature for the Ca-rich members. Grossular and spessartine formed at 420 ° C have a
0=11.901(2) Å and 11.632(2) Å, indicating the presence of 0.6 and 0.2 mol H2O, respectively. Intermediate members show varying degrees of hydration. Infrared spectra of the more hydrated members show a major and minor absorption bands at 3,620 cm–1 and 3,660 cm–1, respectively, in addition to a broad band around 3,430 cm–1. All the hydrogarnets formed at 420 ° C were proven to be metastable.The rare occurrence of the intermediate grossular-spessartine garnets may be attributed to the lack of appropriate bulk chemistry of the rock rather than to the P-T conditions to which the rock is subjected. There may be a stability field for hydrogrossular below 420 ° C at 2 Kb, but not for hydrospessartine. Any occurrence of hydrogarnet may be used as a temperature indicator setting the maximum of formation for the hydrogarnet-bearing assemblage below 420 ° C at 2 Kb. 相似文献
80.
Mesoscale cellular convections over the East China Sea during cold air outbreaks are simulated with a high-resolution numerical model. The model incorporates important physical processes involved in shallow convection, such as the exchange of heat and moisture between water and air; condensation; evaporation; and vertical turbulent transfer of heat, moisture, and momentum.The results show that open cells develop with aspect ratios as large as 14. The structure of the convection is examined in detail. The organized mesoscale circulation is responsible for breaking up the initial stratus cloud deck and enhancing turbulence in the upward-moving area (especially inside cumulus clouds). However, it is found that the heat flux contributed by MCC's themselves is much smaller than the eddy heat flux. 相似文献