对豫西小秦岭太华群的重新认识

太华群具明显的两分性特征，下亚群属下部基底岩系，原岩为拉斑玄武岩及ＴＴＧ岩系；上亚群属上部基底岩系，具孔达岩系特征的一套沉积变质岩。根据生物地层学、岩石地层学、构造地层学、同位素年代学，提出了小秦岭地区的太华群上下亚群是不同地质时期、不同构造环境下的产物，下亚群时代为晚太古代，上亚群时代为古元古代，故太华群应予以解体．或给以新的内涵。     

High-mass X-ray binaries and recent star formation history of the Small Magellanic Cloud

We study the relation between high-mass X-ray binary (HMXB) population and recent star formation history (SFH) for the Small Magellanic Cloud (SMC). Using archival optical SMC observations, we have approximated the color-magnitude diagrams of the stellar population by model stellar populations and, in this way, reconstructed the spatially resolved SFH of the galaxy over the past 100 Myr. We analyze the errors and stability of this method for determining the recent SFH and show that uncertainties in the models of massive stars at late evolutionary stages are the main factor that limits its accuracy. By combining the SFH with the spatial distribution of HMXBs obtained from XMM-Newton observations, we have derived the dependence of the HMXB number on the time elapsed since the star formation event. The number of young systems with ages ? 10 Myr is shown to be smaller than the prediction based on the type-II supernova rate. The HMXB number reaches its maximum ～20–50 Myr after the star formation event. This may be attributable, at least partly, to a low luminosity threshold in the population of X-ray sources studied, L _min ～ 10³⁴ erg s^?1. Be/X systems make a dominant contribution to this population, while the contribution from HMXBs with black holes is relatively small.     

‘We do not want to leave our land’: Pacific ambassadors at the United Nations resist the category of ‘climate refugees’

The issue of the social geographical dimensions of climate change is timely and important. This paper sets out to explore one example of this: how people living in the Pacific who are most at risk of being made landless by climate change are portrayed in policy discourse, and how high-level international representatives of Pacific nations have responded to these portrayals. At the heart of this is contention over the portrayal of Pacific Island peoples as ‘climate refugees’. This paper analyses a number of documents since the 1980s, largely from non-governmental organisations (NGOs) that deploy the identity construct of ‘climate refugees’. Fieldwork undertaken at the United Nations in New York in 2004 also enabled seven interviews with national ambassadors representing Pacific small island states. Interviews revealed how Pacific ambassadors have responded to the category of ‘climate refugees’, and positioned themselves in the discursive field surrounding the climate change debate. A poststructuralist framework, drawing on Foucault’s ideas of discourse and subject categories provided a means to critically scrutinise and better understand how people from Pacific countries are imagined in the wider, global geopolitical arena, but crucially, how leaders from these nations also construct themselves in relation to climate change and its associated impacts.     

“Sinking islands” and the UNSC: Five modalities of mobilising science

Kiribati, Tuvalu, Marshall Islands, the Maldives and other small island developing states in the Pacific are often incorrectly called “sinking islands.” With their highest points just a few meters above sea level, they face adverse impacts from climate change and especially sea level rise, which can cause them to disappear entirely or make their territory uninhabitable. After rather frustrating negotiations on other fora, the representatives of those states asked the UN Security Council to deal with their perilous situation in 2007. On the one hand, some countries used scientific argumentation to justify the introduction of this new security agenda. On the other hand, prominent UNSC members such as China and Russia, supported mainly by rapidly developing large countries, rejected it, arguing that the Security Council did not have the expertise to solve environmental problems. Since then the islands have echoed their plight to the UNSC in 2011 and 2015. This paper determines what roles individual countries ascribe to “experts” and “science” during UNSC negotiations. It examines how the authority of “experts” was exploited, which allowed certain countries to strike the issue of those islands from the UNSC agenda by calling for a more “scientific approach,” while others used “science” to widen the concept of security. The analysis of empirical data confirms the theory of Berling's three modalities when referring to science. Those modalities can be further extended by Foucault's conception of “will to truth” as a method of exclusion, and Chandler's theory of “empire in denial” as a way of evading responsibility, while maintaining power.     

小岩浆大流体成大矿与透岩浆流体成矿作用——以东秦岭-大别山成矿带钼矿床为例

岩浆活动与内生金属成矿作用关系密切,备受国内外矿床学家的关注。表现为它们在时空上具有广泛的一致性,成矿与岩浆岩有关,成矿物质由同源岩浆分异演化而来。这便是著名的岩浆热液成矿理论,也称岩浆期后热液成矿理论,该理论把内生金属成矿系统看作是一个理想系统。东秦岭-大别山地区的钼矿-花岗岩关系研究表明,钼成矿与小岩体(小岩浆)关系密切,而大岩体/基与钼矿没有成生联系;地质事实表明,大型-超大型矿床往往广泛发育了大规模的热液(流体)蚀变(大流体),具有大的流体/岩浆比,其矿化蚀变范围是小岩体的几十甚至几百倍,表明成矿过程中必有外来流体的广泛参与。由于小岩体往往没有经过强烈的分异结晶作用,质量平衡计算表明,小岩浆体不可能产生足够数量的含矿流体和成矿物质;因此,成岩与成矿有本质的区别,成矿系统应是一个非线性的复杂性动力学系统。研究表明,东秦岭-大别山小斑岩体来源较深(下地壳),成矿流体来源于地幔,二者呈双层结构;岩浆实际上是沟通深部和浅部的通道,这种非岩浆分异的外来成矿流体我们称之为透岩浆流体。小岩体不是成矿的必备的条件,只有出现大流体时才能成大矿。东秦岭-大别山地区有200多个小岩体,但大型、超大型钼矿矿床仅有10余个,只有小岩浆(小岩体)大流体(强蚀变)成大矿,其余众多小岩体由于没有流体(蚀变)或流体少(弱蚀变)而不成矿或成小矿。由此可见,岩浆成矿系统实际上是一种流体(挥发分)过饱和系统或熔体-流体流及流体对熔体的强相互作用。当岩浆系统被加入大量源自地幔的高温高压含矿流体之后,系统将具有极大的活动能力,从而深部含矿流体沿裂隙快速上升到地壳浅部卸载成矿。为解释上述成矿特征,作者引入并厘定了透岩浆流体的概念。透岩浆流体被重新定义为透过岩浆活动并导致岩浆系统行为发生非线性变化的外来流体。据此,输入了含矿流体的岩浆可成矿,未输入含矿流体的岩浆不成矿。这种认识可以解释东秦岭-大别山地区大多数小岩体不成矿或只形成小矿的现象。     

Profitability and economic drivers of small pelagic fisheries in West Africa: A twenty year perspective

Small pelagics are the main fish resource in North West Africa. In Senegal, these are mainly sardinellas (Sardinella aurita and S. maderensis) and bonga shad (Ethmalosa fimbriata). The fisheries, mainly encircling gillnets and purse seines, are predominantly performed by artisanal fishers and are of great importance for the Senegalese economy and for food security in the region. However, in recent years, the main conditions for these fisheries have changed and recent observations have shown strong declines in profit. An analysis over the last twenty years (1993–2013) show that the fisheries lost profit between 65% and 100% while operating costs increased by 25% and 90%, for encircling gillnet and purse seine, respectively. While the fuel price dominates as determining factor during the survey period, important other drivers during the last five years were a decrease in fish biomass and an increase in fishing effort.     

Forecasting bivalve landings with multiple regression and data mining techniques: The case of the Portuguese Artisanal Dredge Fleet

This paper develops a decision support tool that can help fishery authorities to forecast bivalve landings for the dredge fleet accounting for several contextual conditions. These include weather conditions, phytotoxins episodes, stock-biomass indicators per species and tourism levels. Vessel characteristics and fishing effort are also taken into account for the estimation of landings. The relationship between these factors and monthly quantities landed per vessel is explored using multiple linear regression models and data mining techniques (random forests, support vector machines and neural networks). The models are specified for different regions in the Portugal mainland (Northwest, Southwest and South) using six years of data 2010–2015). Results showed that the impact of the contextual factors varies between regions and also depends on the vessels target species. The data mining techniques, namely the random forests, proved to be a robust decision support tool in this context, outperforming the predictive performance of the most popular technique used in this context, i.e. linear regression.     

Fishing without quota: The ACE fisher in New Zealand's inshore fishery

The annual catch entitlement (ACE) scheme was added to New Zealand's quota management system for fisheries in 2001. The scheme allocates quota owners an annual share of the total allowable commercial catch (TACC) in proportion to their quota holding of a particular fishstock. With ACE being transferable, the change made it simpler for fishers (permit holders) who did not own quota to purchase ACE to match catch for specific fishstocks. But to be viable, non-quota-owning (ACE reliant) fishers need access to a reliable, long-term supply of ACE. This study examines the relationships between ACE reliant purchasers and their suppliers of ACE in New Zealand's Fishing Management Area Three during the 2014-15 fishing year. The study found that most buyers and sellers of ACE form enduring relationships to their mutual benefit. This symbiotic relationship bodes well for the survival of small fishers with the expertise to land fish in an efficient manner.     

Study of small ions concentration in the air above Athens, Greece

Measurements of positive and negative small atmospheric ion concentrations have been made regularly since 1968 at the National Observatory of Athens (NOA). In this paper the 17-year period 1968–1984 is summarized. The diurnal and annual variations are examined, and Fourier analysis is also used for the study of the diurnal variation. The concentrations of small ions follow a double diurnal course. The maxima occur near 3–5 h and 13–16 h local time (LT = GMT + 2 h). The minima are observed at 6–8 h and 21–23 h. The annual course of small ions presents maximum concentration values around the summer season. The mean of the small ion concentration (SIC) for the 17-year period (1968–1984) is n₊ = 188.8 ions/cm³ for positive ions and n₋ = 151.1 ions/cm³ for negative ions. Their ratio is equal to 1.25. The year-to-year variation of SIC for the examined period shows a negative trend. The results from multiple regression analysis show that wind speed and SIC are positively correlated, while relative humidity, smoke and sulphur dioxide are negatively correlated.     

Food habits of the Barn Owl (Tyto alba) in a steppe area of Tunisia

The diet of the Barn Owl (Tyto alba) is well known in different habitats but a lack of data persists for arid and subarid environments. We provide preliminary information on food selection of barn owls in Tunisia by the analysis of the composition of pellets. The diet consists largely of rodents and the three-toed Jerboa (Jaculus jaculus) that accounted for more than 50% of total prey biomass. Results suggest that barn owls show a nonrandom tendency toward rodent species especially small and young individuals.