Financial development "accelerates economic growth and improves economic performance to the extent that it facilitates the migration of funds to the best user, i.e., to the place in the economic system where the funds will earn the highest social return," noted Raymond W. Goldsmith (1969, p. 400) some 40 years ago. Information production plays a key role in this process of steering of funds to the highest valued users. If the costs of information production drop, then financial intermediation should become more efficient with an associated improvement in economic performance.Improvements in the efficiency of financial intermediation, due to improved information production, are likely to reduce the spread between the internal rate of return on investment in firms and the rate of return on savings received by savers. The spread between these returns reflects the costs of intermediation. This spread will include the ex post information costs of policing investments, and the costs of the misappropriation of savers' funds by management, unions, etc., that arise in a world with imperfect information. There may be no change in the rate of return earned by savers over time, because aggregate savings will adjust in equilibrium so that this return reflects savers' rates of time preference. If the wedge between the internal rate of return earned by firms and the rate of return received by savers falls, due to more effective intermediation, then both the economy's capital stock and income should rise. Additionally, if capital is redirected away from the less productive investment opportunities in the economy toward more productive ones, then the economy's output will rise further and productivity move up. In fact, empirical research strongly suggests that financial development has a causal effect on economic development-see Ross Levine (2005) for a masterful survey. Specifically, financial development leads to higher rates of growth in the capital stock, income, and productivity.A general equilibrium model of firm finance, with competitive intermediation, is presented to address the impact that financial intermediation has on economic development. At the heart of the framework developed here is a costly-state verification paradigm that has its roots in classic work by Robert M. Townsend (1979) and Stephen D. Williamson (1986). The model here has two novel ingredients, though. First, in the standard costly-state verification paradigm, the realized return on a firm's investment activity is private information. This return can be monitored, but the outcome of this auditing process is deterministic: once monitoring takes place, the true state of the world is revealed with certainty. This is true whether or not a deterministic decision rule for monitoring is employed, as in Townsend (1979) or Williamson (1986Williamson ( , 1987, or a stochastic

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Graphene has aroused great interest on account of its exciting properties and potential applications, but its production on a large-scale still presents considerable challenges. Here, we report the synthesis of predominately few-layer graphene, due to - stacking, as well as single-layer graphene, from reaction between hexabromobenzene and sodium metal, followed by annealing treatment to improve crystallinity.The reaction proceeds via a free-radical C(sp 2 )-C(sp 2 ) coupling mechanism, which is supported by theoretical calculations. The graphene can host unpaired spins, leading to a short acquisition time for a solid-state nuclear magnetic resonance 13 C spectrum from unlabeled graphene, which is ascribed to the very short spinlattice relaxation time. High catalytic activity for transforming amine to imine with a conversion of >99% and a yield of 97% is demonstrated, and high electronic conductivity of 10 5 Sm -1 has been found by terahertz spectroscopy. The reaction represents a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent, such as, Na or Li, or Mg.

A novel frequency selective surface (FSS) has been designed based on 2.5-dimensional (2.5D) closed loop for miniaturisation. Compared with the previous FSSs in the literature, the proposed FSS is smaller (0.048λ 0 × 0.048λ 0 ) and shows almost the same transmission coefficient for different polarisations and incident angles. A prototype of the proposed FSS has been fabricated and measured. The results of the experiment show a consistency with the simulated ones.Introduction: Frequency selective surfaces (FSSs) are usually twodimensional (2D) periodic arrays, and their required frequency selective behaviours are obtained by the various resonant elements in the unit cell, such as a loop, or a dipole, or their complementary structures, or even a combination of them [1,2]. In the past decades, FSSs have been intensively investigated in the microwave and millimetre-wave frequency range, and they are widely used as antenna reflectors, radomes, spatial filters, electromagnetic bandgap materials, electromagnetic shields and so on [2][3][4]. The most important step in the design process of a desired FSS is the proper choice of resonant elements in the unit cell (which is called 'FSS element' in this Letter). In a comprehensive review of the traditional FSS elements [1], one common feature of the traditional FSS elements is that their sizes are comparable with half of a wavelength at the operating frequency [3,5]. However, the practical FSS is usually fabricated in finite dimensions, and the miniaturised FSS element is desired to enable the FSS with sufficient number of resonant elements to act as an infinite array, which lowers the sensitivity to the incident waves. To miniaturise the FSS element, different structures and methods have been proposed. For example, a miniaturised FSS consisting of a periodic array of metallic patches printed on one side of a dielectric substrate and a wire mesh printed on the other side is proposed in [5]. Closed loop and its complementary pattern are used to design a miniaturised FSS [6]. In [7], a new FSS element of spiral slots is proposed to reduce the unit cell electric size. Recently, miniaturised FSSs using complex planar topologies [8] and a novel 2.5D structure [9] are reported.In this Letter, a novel miniaturised FSS is proposed based on the 2.5D closed loop. In the FSS element or the unit cell, two pairs of the metal split square rings are printed on the top and bottom sides of the dielectric substrate. The four split square rings are connected by four metal vias in series, forming a closed loop. Compared with the traditional FSS designed with 2D loops, the proposed FSS element has a lower resonant frequency due to its longer perimeter which exhibits miniaturisation and provides favourable resonant stability at various polarisations and incident angles. To validate the performance of the proposed FSS, a prototype has been fabricated and measured. The results show a good consistency between the full-wave simulations and the measurements.