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Aim of this study is to investigate the properties of mono-atomic gas flow through the porous medium by using Event-Driven Molecular Dynamics (EDMD) simulation in the transition regime. The molecules and the solid particles forming the porous structure were modelled as hard spheres hence molecule trajectories, collision partners, interaction times and post-collision velocities were calculated deterministically. The porous medium is formed of spherical particles suspended in the middle of the channel and these particles are distributed into the channel in a regular cubic array. Collisions of gas molecules with porous medium were provided by means of the specular reflection boundary condition. A negative pressure boundary condition was applied to the inlet and outlet of the porous media to ensure gas flow. Porosity, solid sphere diameter and Knudsen number (Kn) were initially input to the simulation for different Cases. Thus, the effects of these parameters on mass flow rate, dynamic viscosity, tortuosity and permeability were calculated by EDMD simulation. The results were compared with the literature and were found to be consistent.

When the leader of an autocratic regime loses power, one of three things happens. The incumbent leadership group is replaced by democratically elected leaders. Someone from the incumbent leadership group replaces him, and the regime persists. Or the incumbent leadership group loses control to a different group that replaces it with a new autocracy. Much scholarship exists on the first kind of transition, but little on transitions from one autocracy to another, though they make up about half of all regime changes. We introduce a new data set that facilitates the investigation of all three kinds of transition. It provides transition information for the 280 autocratic regimes in existence from 1946 to 2010. The data identify how regimes exit power, how much violence occurs during transitions, and whether the regimes that precede and succeed them are autocratic. We explain the data set and show how it differs from currently available data. The new data identify autocratic regime breakdowns regardless of whether the country democratizes, which makes possible the investigation of why the ouster of dictators sometimes leads to democracy but often does not, and many other questions. We present a number of examples to highlight how the new data can be used to explore questions about why dictators start wars and why autocratic breakdown sometimes results in the establishment of a new autocratic regime rather than democratization. We discuss the implications of these findings for the Arab Spring.

The genesis of giant gold provinces is an international scientific frontier, in which the source of a huge amount of gold and the drive for mineralization are key challenges. The mineralization intensity of the Jiaodong gold province in eastern China is a rare occasion in the world, because it owns gold reserves of ∼5500 tons within an area of less than 10,000 km 2 . The Jiaodong gold province formed in the superimposed domain of diverse tectonic regimes in an intracontinental setting. Paleoproterozoic regional peak metamorphism and Triassic continental collision are followed by the tectonic transition and gold mineralization at ca. 120 Ma with time intervals of 1.9 billion years and about 100 million years, respectively. The Jiaodong gold deposits are different from orogenic and intrusion-related gold deposits in terms of the tectonic background, types of host rocks, and ore-forming mechanism. These gold deposits show close spatial-temporal and genetic relationships to mafic igneous rocks, implying the derivation of ore-forming fluids from the metasomatic mantle domains. Mafic dykes in Jiaodong have negative ε Hf ( t ) values of −29.9 to −9.1, Os content of 0.002–0.16 ppb, heavy δ 18 O up to 8.23‰, and high initial 187 Os/ 188 Os ratios of 0.1352–0.8858. These indicate that the lithospheric mantle was metasomatized by ancient crust-derived components. The lithospheric mantle in the western Jiaodong shows generally more enriched isotope features than that in the eastern part, which is explained to be an important reason for its huge gold resources. The mafic dykes show lighter Mg isotope characteristics (average δ 26 Mg of −0.33‰, n =50) and high CaO content (overall greater than 6.5 wt%), indicating that the lithospheric mantle would also record the metasomatism by the carbonate rocks from the subducting oceanic slab. Under the background of the rollback of the subducting paleo-Pacific slab and the destruction of the North China Craton, partial melting of the lower crust would produce granitic magmas that led to the enrichment of gold in the residual crust. The syn-mineralization asthenosphere upwelling would promote the recycling of the lower crust and the partial melting of the metasomatic mantle domains. Basic magmas, produced by the partial melting, and the mantle itself would degas to form ore fluids. The ore fluids would further leach gold in the lower crust to increase its fertility. The auriferous fluids were transported to the middle to upper crust along the detachment and strike-slip faults. Water-rock interaction and fluid immiscibility, which occurred in and above the ductile-brittle transition zone to induce gold precipitation, formed the Jiaodong gold deposits. Given the unique geological features and genetic model of the Jiaodong gold deposits, they can be defined as “Jiaodong-type” gold deposits.

Recent work by Carles Boix and Daron Acemoglu and James Robinson has focused on the role of inequality and distributive conflict in transitions to and from democratic rule. We assess these claims through causal process observation, using an original qualitative dataset on democratic transitions and reversions during the “third wave” from 1980 to 2000. We show that distributive conflict, a key causal mechanism in these theories, is present in just over half of all transition cases. Against theoretical expectations, a substantial number of these transitions occur in countries with high levels of inequality. Less than a third of all reversions are driven by distributive conflicts between elites and masses. We suggest a variety of alternative causal pathways to both transitions and reversions.

Most discrete neuron models have simple algebraic structures with easy digital implementation. However, they cannot show the abundant firing regimes of neurons. To address this issue, in this paper, we propose an improved discrete tabu learning neuron (IDTLN) model using sine nonlinearity as the activation function. Using this model, the fixed points and their stability are analyzed theoretically, the parameter-related bifurcation and regime transition behaviors as well as heterogeneous multistability are investigated by numerical tools, and the multi-scroll hyperchaotic behaviors are revealed according to the dynamics distribution in the parameter plane. It is shown that the IDTLN model has two types of fixed points, stable and unstable, and their number and stability types change with the parameters, which leads to the formation of multistability and the generation of multi-scroll hyperchaotic attractors. Besides, we design six pseudorandom number generators (PRNGs) using multi-scroll hyperchaotic sequences provided by the IDTLN model and evaluate their randomness using TestU01. The evaluation results show that this proposed neuron model has high randomness without chaos degradation, which is particularly suitable for PRNG application. Finally, we develop a digital hardware platform to verify the regime transition and multi-scroll hyperchaos of the IDTLN model.

Once considered a 'hot topic' among scholars, research on coups d'état has waned in recent years. This decline is surprising given that 7 coups have happened between January 2008 and December 2010, bringing the last decade's total to almost three dozen. One explanation for the lack of coup research is the absence of a temporally and spatially comprehensive dataset to test theories. Also absent is a discussion of what makes coups distinct from other forms of anti-regime activity. This article seeks to remedy these problems. The authors present a new dataset on coups from 1950 to 2010. They begin by explaining their theoretical definition and coding procedures. Next, they examine general trends in the data across time and space. The authors conclude by explaining why scholars studying a variety of topics, including civil wars, regime stability, and democratization, would benefit by paying closer attention to coups.

Fine-grained sediment (grain size under 2,000 μm) builds floodplains and deltas, and shapes the coastlines where much of humanity lives. However, a universal, physically based predictor of sediment flux for fine-grained rivers remains to be developed. Herein, a comprehensive sediment load database for fine-grained channels, ranging from small experimental flumes to megarivers, is used to find a predictive algorithm. Two distinct transport regimes emerge, separated by a discontinuous transition for median bed grain size within the very fine sand range (81 to 154 μm), whereby sediment flux decreases by up to 100-fold for coarser sand-bedded rivers compared to river with silt and very fine sand beds. Evidence suggests that the discontinuous change in sediment load originates from a transition of transport mode between mixed suspended bed load transport and suspension-dominated transport. Events that alter bed sediment size near the transition may significantly affect fluviocoastal morphology by drastically changing sediment flux, as shown by data from the Yellow River, China, which, over time, transitioned back and forth 3 times between states of high and low transport efficiency in response to anthropic activities.

PurposeThe Italian school-to-work transition (STWT) is astonishingly slow and long in comparison to the other EU countries. We analyze its determinants comparing the Italian case with Austria, Poland and the UK.Design/methodology/approachThe analysis is based on a Cox survival model with proportional hazard. The smoothed hazard estimates allow us to identify the nonlinear path of the hazard function.FindingsThe authors reckon that the actual length of the transition to a stable job is around 30 months in Italy. Conversely, it is less than one year in the other countries. Women are particularly penalized, despite being on average more educated than men. Tertiary or vocational education at high secondary school strongly increases the hazard rate to a regular job. The smoothed hazard estimates suggest positive duration dependence at the beginning of the transition and slightly negative thereafter.Practical implicationsStimulating economic growth and investing in education and training are important pre-conditions for shortening the transition.Originality/valueDespite the duration of the STWT is one of the most important indicators to measure the efficiency of the STWT, it is not easy to measure. The authors build on their previous research work on this topic, but relaxing the assumption of a monotonic hazard rate and using the flexible baseline hazard approach to test for the existence of nonlinear duration dependence. Furthermore, they extend the analysis by including student-workers who attended a vocational path of education, in order to detect its effectiveness in allowing young people finding a job sooner.

The appeal of revolutionising urban governance through information technologies has prompted cities across the globe to pursue smart city initiatives. The mainstream scholarship on these initiatives has mostly focused on technology and corporate-led urban development, and it also often privileges the experience of cities in the global North. Nevertheless, this mainstream understanding of the smart city may obscure emerging new power dynamics and locally contextualised processes associated with smart urban development, especially in cities at the global periphery. Inspired by post-colonial theories, this article makes the case for ‘provincialising’ smart urbanism by dislodging technology from the centre of analysis, accentuating perspectives of cities outside the locations where the smart city knowledge is traditionally produced and attending to power relationships. In our case study of Taipei, this provincialising approach helps unveil various logics, intentionalities, assemblages and power dynamics through which the smart city is employed as a political strategy to facilitate urban regime transition. We argue that the current non-affiliated Ko administration exploits the veneer of technological superiority and political neutrality of its smart city agenda to set a new growth agenda, form new development coalitions, establish new institutions and incorporate rising populist momentum into policy-making. Focusing on the politics of being smart, our findings illustrate how smart city experiments reshape power dynamics and regime formation through reorganising actors and interest groups, reconfiguring government institutions, reallocating resource distribution and, in the end, bolstering governing legitimacy. 通过信息技术变革城市治理的吸引力促使全球各地的城市开展智慧城市计划。关于这些计划的主流学术研究主要集中在技术和企业主导的城市开发上，而且通常优先考虑全球北方城市的经验。然而，这种对智慧城市的主流认识可能会掩盖新出现的权力动态、以及与智慧城市开发相关的本地处境化过程，尤其是在全球边缘城市的这一过程。受后殖民理论的启发，本文不将技术作为分析的核心因素，而是强调传统上的智慧城市知识生产地点之外的城市的视角，并关注权力关系，从而为智慧城市的“地方化”辩护。在我们对台北的案例研究中，这种地方化的方法帮助我们揭示各种逻辑、刻意性、集合和权力动态，通过这些逻辑、刻意性、集合和权力动态，智慧城市被用作一种政治策略来促进城市体制的转变。我们认为，当前由无党籍的柯文哲领导的台北市政府利用其智慧城市议程的技术优势和政治中立的表象制定新的增长议程，形成新的发展联盟，建立新的机构，并将日益高涨的民粹主义势头纳入政策制定过程。我们的发现聚焦于智慧城市的政治方面，说明智慧城市实验如何通过重组行为者和利益集团、重新配置政府机构、重新分配资源以及最终增强治理合法性来重塑权力动态和体制结构。

This article examines how authoritarian parties and legislatures affect regime survival. While authoritarian legislatures increase the stability of dictators, political parties – even when devised to quell internal threats – can destabilize dictators. The main argument is that authoritarian parties influence the distribution of power in a subsequent new democracy by helping to protect the interests of authoritarian elites. These institutions thus increase the likelihood of democratization. Using a dataset of authoritarian regimes in 108 countries from 1946 to 2002 and accounting for simultaneity, the analysis models transitions to democracy and to a subsequent authoritarian regime. Results indicate that authoritarian legislatures are associated with a lower probability of transition to a subsequent dictatorship. Authoritarian parties, however, are associated with a higher likelihood of democratization.