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171.
This paper evaluates the effectiveness of European Cohesion Policy in the regions of 12 EU countries in the period 1991–2008, on the basis of a spatial growth model, which allows for the identification of both direct and indirect effects of EU funds on GDP per worker growth. We find that “Objective 1” funds are characterized by strong spatial externalities and a positive and concave effect on the growth of GDP per worker, which reaches a peak at the ratio funds/GDP of approximately 3 percent and becomes non‐significant after 4 percent. “Objective 2” and “Cohesion” funds have nonsignificant effects, while all the other funds exert a positive and significant effect, but their size is very limited. EU Cohesion Policy, moreover, appears to have increased its effectiveness over time. In the period 2000–2006 Objective 1 funds are estimated to have a median multiplier equal to 1.52, and to have added 0.37 percent to the GDP per worker growth. Overall, in the period 1991–2008, funds are estimated to have added 1.4 percent to the median annual growth, and to have reduced regional disparities of 8 basis points in terms of the Gini index.  相似文献   
172.
ABSTRACT

For more than two decades, theories on regional clusters have inspired economic and structural policies at the European, national and regional levels. Based on the assumption that clusters generate innovation, policy-makers at all levels of governance have adopted instruments and mechanisms to stimulate, resource and sustain clusters. Despite the considerable attention paid to the clustering phenomenon, empirical evidence on to what extent firms’ innovation activities benefit from operating in clusters is scarce and inconclusive. This paper contributes to the micro-foundation of clustering effects by examining the characteristics and activities of cluster firms in relation to their innovativeness. Bridging innovation, management and cluster theories, it is argued that structural and relational embeddedness, relational capital and absorptive capacity influence clustered firms' innovativeness. Partial least-squares structural equation modelling of data from 104 firms in two software and information technology service sector clusters reveals that firms’ structural embeddedness (i.e. frequency of interactions) in clusters and external networks facilitates innovation cooperation. Firms’ absorptive capacity reinforces this positive effect of cluster-internal interactions on innovation cooperation. Results also suggest a substitution effect of trust as relational control mechanisms for formal control mechanisms within the cluster. However, the study finds no significant impact of firms’ innovation cooperation within the cluster (i.e. relational embeddedness) on their innovation success.  相似文献   
173.
R. Fernandes 《Archaeometry》2016,58(3):500-512
Quantitative individual human diet reconstruction using isotopic data and a Bayesian approach typically requires the inclusion of several model parameters, such as individual isotopic data, isotopic and macronutrient composition of food groups, diet‐to‐tissue isotopic offsets and dietary routing. In an archaeological context, sparse data may hamper a widespread application of such models. However, simpler models may be proposed to address specific archaeological questions. As a consequence of the intake of marine foods, individuals from the first century ad Roman site of Herculaneum showed well‐defined bone collagen radiocarbon age offsets from the expected terrestrial value. Taking as reference these radiocarbon offsets and using as model input stable isotope data (δ13C and δ15N), the performance of two Bayesian mixing model instances (routed and concentration‐dependent model versus non‐routed and concentration‐independent) was compared to predict the carbon contribution of marine foods to bone collagen. Predictions generated by both models were in good agreement with observed values. The model with higher complexity showed only a slightly better performance in terms of accuracy and precision. This demonstrates that under similar circumstances, a simple Bayesian approach can be applied to quantify the carbon contribution of marine foods to human bone collagen.  相似文献   
174.
The purpose of this study was to illuminate the perspectives of women who experienced sexual violence perpetrated in the warscapes of eastern Democratic Republic of Congo. Civilians are targeted for rape, loot and pillage yielding deleterious effects on the social fabric and the sustenance the community provides. The article is based on 11 qualitative semistructured interviews and 4 written narratives from women of reproductive age, recruited from organizations providing support post-sexual violation. The study departs from a larger ethnographic project investigating the phenomenon of war-rape. Thematic analysis guided the analysis through the theoretical lenses of structural violence and intersectionality. The women expressed total insecurity and a multitude of losses from bodily integrity, health, loss of family, life course possibilities, livelihoods and a sense of place; a profound dispossession of identity and marginalization. Pregnancies resulting from rape reinforced stigma and burdened the survivor with raising a stigmatized child on the margins of society. Perpetrators of rape were mostly identified as Interhamwe (Rwandan Hutus rebels) who entered Congo after the Rwandan genocide in 1994. Their goal, according to the women, was to spread HIV and impregnate Congolese women, thereby destroying families, communities and society. The women survivors of war-rape described experiences of profound loss in this conflict which has global, ethnic and gendered dimensions. Congo's conflict thus requires critical reflection on how local wars and subsequent human suffering are situated in a matrix of globalization processes, enabled by transnational actors and embedded in structural violence.  相似文献   
175.
This study focuses on domes the ground plan of which, instead of the more common circular shape, is an oval, and aims at finding the minimally necessary uniform wall thickness for domes of different geometries loaded by their selfweight. The discrete element code 3DEC was applied because of its capability of simulating the collapse mechanisms of masonry structures. Results on the minimal wall thickness, corresponding masonry volume and failure mechanisms for different dome geometries are presented. Three ranges of the friction coefficient were found. For very low frictional resistance collapse happens with pure frictional sliding, for any arbitrarily large wall thickness. In the range of relatively high (i.e., realistic) friction coefficients the structure collapses without any sliding if the wall is not sufficiently thick, and in the observed range of the friction coefficient the necessary wall thickness is nearly insensitive to its value (collapse initiates with hinging cracks only). Between the two domains an intermediate behavior was found: combined cracking and sliding collapse modes occur for insufficient wall thickness, and the minimal thickness strongly depends on the friction coefficient. The critical and transitional friction coefficients separating the failure modes were determined for different eccentricities of the groundplan.  相似文献   
176.
采用ICP等离子体发射光谱方法,测试分析了安徽张四墩遗址和薛家岗遗址出土陶器的微量元素,并运用热膨胀法测定了低温古陶器的烧成温度。在此基础上,结合考古发掘资料,将测试数据作多元统计分析,系统讨论了张四墩遗址不同文化风格古陶的矿料来源,并探讨了张四墩遗址与薛家岗遗址陶器的产地、渊源的关系和制陶工艺方面烧成温度的变化关系,研究结果表明:张四墩遗址反映的文化是一种多元性的文化。一方面,它承继了本地薛家岗文化的部分因素,另一方面,受到东部的良渚文化,特别是北方大汶口文化的强烈影响。  相似文献   
177.
The apparent ability of petroleum to migrate rapidly through low permeability sediments in sedimentary basins has led to many questions about the manner of its transport. One possible explanation is suggested from observations of the compaction of viscously deformable porous media. These systems have been found in some cases to give rise to regions of locally elevated liquid fraction, in the form of fluid‐filled porosity waves that can ascend at rates much greater than that of the background flow. Previous research on the phenomenon has focused on its implications for magma transport, but recognition of the fact that the compaction of viscous porous media can take place in sedimentary basins has suggested the possibility that porosity waves could similarly be important for hydrocarbon transport. The purpose of the present study was to test this hypothesis by quantifying the transport that would occur as the result of porosity waves initiated during the conversion of kerogen to petroleum. A one‐dimensional numerical model was constructed solving equations for the mechanics of viscous compaction and for the kinetics of reactions describing the formation of petroleum from kerogen. The results showed that porosity waves would develop readily in viscously deformable regions of sedimentary basins, but would not necessarily provide enhanced transport over that of the background flow regime. In order for the waves to achieve this enhanced transport, they must develop high amplitudes, i.e. high porosities relative to the background porous medium. To achieve the high wave amplitudes, the background porosity must be very low in absolute terms. In addition, high kerogen contents are needed in the source layer, and the source layer needs to be buried rapidly to a high temperature region of the oil window. Considerable uncertainty exists as to the value of the matrix shear viscosity of sediments in basins. However, the wave volumetric transport capacity was not found to be significantly altered as a result of variations in the value of this parameter. The physical form of the waves was strongly altered by the matrix shear viscosity, with higher values leading to lower amplitudes and generation frequency, but higher wavelengths. Thus the waves become less recognizable physically at higher values of the matrix shear viscosity. As the waves ascend to higher stratigraphic levels, where the porosity is higher, they gradually lose their physical definition and become absorbed into the background.  相似文献   
178.
This paper applies a compartmental epidemic modelling system to the estimation of HIV infection transfers between the nations of Western Europe for the period 1973–98. This multiregional model imitates the formation of disease contacts by both local and international travel, where the latter is assumed to have the lower sensitivity to the effects of spatial separation. This system is calibrated in two stages: first, disease parameter sets are found to best fit the timing of recorded AIDS incidence in each nation; and second, these sets are entered into a multiregion setting to identify the travel parameters that support the lags between these series. The outputs include estimates for the first year of HIV incidence in each country and the subsequent pathways of infection transfer that connect these dates. The results indicate the contrasting roles of the southern and northern countries within the continental epidemic and point to national variations in the recent delaying effects on AIDS incidence of drug combination therapies.  相似文献   
179.
The recent introduction of big box retailers into Canadian cities has altered dramatically the competitive retail landscape. This rapid restructuring of the urban retail economy have occurred since the introduction of the big box/power centre phenomenon in the early 1990s. The analysis integrates the extensive databases that reside at the Centre for the Study of Commercial Activity with insights gained from the popular press. These two sources of information were used to interpret the spatial and structural impacts of big box retailing on the traditional urban retail structure in the Greater Toronto Area. The growth of the big boxes illustrates the form of retail development that results from more permissive retail land use policies. A period where the development policies and processes of the past that controlled shopping centre development has been replaced by a more laissez-faire approach.  相似文献   
180.
Y. Deng  L. W. Lake 《Geofluids》2001,1(3):183-193
This paper presents a new method for pore level network simulation of the distribution of two immiscible phases in a permeable medium. The method requires that the Helmholtz free energy of the system — the medium and the two phases contained within the pore space — be a minimum at all saturation states. We describe the method here and show some typical results from a computer algorithm that implements it. The results include (i) an explanation of the ‘scanning’ behaviour of capillary pressure curves based wholly on the free energy minimization, (ii) predictions of capillary pressure at arbitrary wetting states, including negative capillary pressures, and (iii) illustrations of how the minimized free energy changes along the scanning curves. The method also predicts the known dependency of the capillary pressure on the pore size distribution and interfacial tension. The current work is restricted to two‐dimensional networks, but the free energy minimization appears to be generalizable to three dimensions and to more than two fluid phases. Moreover, functions generated through the minimization, specifically contact areas between the medium surface and the phases, appear to have applications predicting other multiphase petrophysical properties.  相似文献   
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