简析中日能源联合议价的成本收益

作为世界第二和第三的大能源消费国,中国和日本在分散竞争的条件下承受了过多的进口成本。本文在分析能源商品的价格决定因素基础上,探讨中日两国进行能源联合议价的成本与收益。认为这种努力可以在消除能源的亚洲溢价、减少能源竞争成本、促进亚洲能源期货市场发展、增强区域经济联系等方面获得显著收益。同时,联合议价的经济成本比较小,国家安全成本和政治成本则在两国之间存在不对称性,并且难以量化。     

An empirical test of the relative frequency of bipolar reduction in Beds VI,V, and III at Mumba Rockshelter,Tanzania: implications for the East African Middle to Late Stone Age transition

Mumba Rockshelter, Tanzania, is the only East African site spanning a continuous record of more than 100,000 years, including the Middle Stone Age (MSA) to Late Stone Age (LSA) Transition. Rather than examine the presence or absence of traditional markers of “behavioral modernity”, we have endeavored here to respond to the calls of Shea (2011) and Basell (2008) by examining the proportional similarity of a trait present throughout the MSA–LSA sequence at Mumba Rockshelter: the bipolar technique of lithic reduction. We use a quantified, experimentally derived proxy to track the relative amount of bipolar percussion among Mumba's Beds VI, V, and III, namely, waste shatter. Our examination of Mehlman's previously unanalyzed collections from Mumba demonstrates that in terms of bipolar production Bed V is statistically indistinguishable from the Late Stone Age (LSA) Bed III, but significantly different from the Middle Stone Age (MSA) Bed VI. Given that Bed V dates to 56.9 ± 4.8 − 49.1 ± 4.3 ka cal BP, this result is consistent with other evidence that the origins of the LSA in East Africa began well before 40 kya, and that Mumba Bed V represents one of the earliest manifestations of the LSA in East Africa. We conclude with a discussion of factors that may have influenced the increased dependence of bipolar production at the site.     

A PROCEDURE FOR ESTIMATING INPUT ENERGY SPECTRA FOR SEISMIC DESIGN

In this paper, the damage potential of an earthquake ground motion is evaluated in terms of the total power of the acceleration of the ground motion. By assuming an appropriate spectral shape for the input energy spectrum, and using the well-known Parseval theorem for evaluating the total power of a random signal, the peak amplification factor for the equivalent input energy velocity spectrum can be determined. It is shown that the peak amplification factor for the input energy spectrum depends on the peak-ground-acceleration to peak-ground-velocity ratio and duration of the strong motion phase of the ground motion. Values for the equivalent input energy velocity amplification factor vary from about 2 to 10 for most of the recorded ground motions used in this study. Although a considerable scatter of data is observed in this study, the peak amplification factor predicted by the Fourier amplitude spectrum of the ground acceleration provides a fairly good estimate of the mean value of the peak input energy compared to that determined from inelastic dynamic time history analyses, particularly for systems with high damping and low lateral strength. The peak amplification factor derived in this paper provides a more consistent approach for estimation of seismic demand when compared to an earlier empirical expression used for the formulation of duration-dependent inelastic seismic design spectra, even though only a slight difference in the required lateral strength results from the use of the new formula.     

PREDICTION OF DAMAGE IN R/C SHEAR PANELS SUBJECTED TO REVERSED CYCLIC LOADING

In this paper, the damage prediction of shear-dominated reinforced concrete (RC) elements subjected to reversed cyclic shear is presented using an existing damage model. The damage model is primarily based on the monotonic energy dissipating capacity of structural elements before and after the application of reversed cyclic loading. Therefore, it could be universally applicable to different types of structural members, includeing shear-dominated RC members. The applicability of the damage model to shear-dominated RC members is assessed using the results from reversed cyclic shear load tests conducted earlier on eleven RC panels. First, the monotonic energy dissipating capacities of the panels before and after the application of reversed cyclic loading are estimated and employed in the damage model. Next, a detailed comparison between the analytically predicted damage and the observed damage from the experimental tests of the panels is performed throughout the loading history. Subsequently, the effects of two important parameters, the orientation and the percentage of reinforcement, on the damage of such shear-dominated panels are studied. The research results demonstrated that the analytically predicted damage is in reasonably good agreement with the observed damage throughout the entire loading history. Furthermore, the orientation and percentage of reinforcement is found to have considerable effect on the extent of damage.     

Can Russia Break the "Resource Curse"?

A noted European economist argues that the Russian economy and its post-2000 growth have been heavily dependent on natural resources, especially hydrocarbons, and are bound to remain so for some time to come. Given that many economists have come to view rich natural resource endowments as a "curse" that undermines development, the question arises as to whether Russian economic development is doomed. The author argues that while the challenges posed by resource dependence are serious, they can be overcome, or at least substantially mitigated, if accompanied by the right economic policies as the examples of Australia, Canada, and the Scandinavian countries demonstrate. He analyzes what these economic policies are for Russia, and how to set up Russian economic and political conditions to facilitate their implementation. Journal of Economic Literature, Classification Numbers: E6, O1, O52, P2, Q43. 4 figures, 2 tables, 50 references.     

Russia's Energy Policy, 1992-2005

A team comprising a former Russian policymaker and American analysts of the current Russian energy policy examines the course of that policy and its limitations during the post-Soviet period. In the process, they critically analyze key problems in Russia's oil, gas, coal, and electricity sectors that represent a potential drag on growth of the entire Russian economy and at the very least call into question the sustainability of further increases in exports to the West. The authors explore in considerable depth and detail both the factors underlying the recent increase in government intervention in the energy sector and the likely consequences for domestic production, consumption, resource security, and critical exports. Journal of Economic Literature, Classification Numbers: L71, O13, Q40, Q48. 11 figures, 3 tables, 29 references.     

Russia's Energy Policy: A Divergent View

A noted American analyst of Russian, Central Asian, and Transcaucasian oil and gas industries and markets offers his own perspective on issues raised in the preceding paper on Russia's energy policy (Milov et al., 2006). While generally concurring that Russia indeed pursues an ad hoc (rather than systemic) energy policy, he expresses divergent views on the role of government-regulated versus market-based pricing in final and primary energy use, reasons for the intense flows of oil and gas to Europe, the role of pipelines in determining oil export allocations, and the contribution of regional monopolies and refining capacity to domestic oil product prices. Journal of Economic Literature, Classification Numbers: L71, O13, Q40, Q48. 20 references.