The Role of Microphytobenthic Primary Production in a Mediterranean Mussel Culture Area

The production and biomass of microphytobenthos in a Mediterranean mussel farm was studied during 1991–92. Gross and net microphytobenthic production and respiration were calculated from oxygen fluxes in transparent and black bell jars at two stations; sediments under a mussel table and reference sediments, both located at 5 m depth. Net oxygen fluxes were mainly negative under the mussel tables (average −19·5 mg O₂ m⁻² h⁻¹, CV=132%), and microphytobenthos production could not meet the sediment oxygen demand; in the reference sediments, microphytobenthos production was responsible for net oxygen production (average +13·0 mg O₂ m⁻² h⁻¹, CV=118%). Benthic respiration rates were, on average, 47·3 mg O₂ m⁻² h⁻¹(CV=82%) under the tables and 27·7 mg O₂ m⁻² h⁻¹(CV=45%) in reference sediments. Aerobic respiration could remineralize less than 2% of the biodeposited carbon under the tables, implying that a large amount of organic material is accumulating under the tables, and that most of the degradation will be anaerobic. Gross microbenthic production showed sharp changes between 1991 and 1992 under the mussel tables and for reference sediments (averages 20·98 mg O₂ m⁻² h⁻¹, CV=135% and 33 mg O₂ m⁻² h⁻¹, CV=48%, respectively). Despite the negative oxygen balance in the sediments under the tables, microphytobenthos was more productive than phytoplankton in bottom waters. Per unit area, phytoplankton was more productive than microphytobenthos at both stations, especially in the area of the mussel tables, where phytoplanktonic production was enhanced by the excretion products of mussels. Microphytobenthos was composed mainly of diatoms in the sediments under the tables, while in reference sediments, the population was more diverse, with algae containing chlorophyllbalso present. Chlorophyllaconcentration in sediments under the tables was 207 mg m⁻²(CV=73%) and 95 mg m⁻²(CV=28%) in reference sediments; the stock of plant pigments was increased under the tables by biodeposition. Microphytobenthos constitutes a compartment with an important contribution in biomass, but also in oxygen production.     

An annual cycle of recruitment,growth and production in a Malaysian population of the trochacean gastropod Umbonium vestiarium (L.)

From July 1981 to July 1982 Umbonium vestiarium (L.) on a north Penang sand shore numbered 573–11 077 m^?2 (mean 4126 or 53·1 g dry tissue) near MLWN and 2164–12 414 m^?2 (mean 6500 or 59·8 g dry tissue) further downshore. Heavy recruitment of young became evident in June and July 1982 and a closely corresponding cohort of young was present in July 1981. Progression of this cohort indicated that young settling in May–June grew to full size (11–13 mm diameter) by January–March the following year and that virtually all died during their second year, presumably having spawned in March–May. Recruitment of young was chiefly on the lower shore but adults came to be more abundant and predominant on the upper shore. There is some evidence of migration upshore during growth.Production is estimated at 105·4 g dry tissue m^?2 y^?1 (2118 kj) at the lower shore level and this is almost double the 58·8 g m^?2 y^?1 (1176·6 kj) at the higher level. These values represent almost the entire secondary production across much of the sand flats.Possible causes of such a marked annual cycle in the very weakly seasonal tropics of the Malacca Strait are considered and it is suggested that monsoonal changes in wind, wave action and salinity might be involved.     

塔河油田碳酸盐岩缝洞型油藏远井储集体定量化表征及动用技术

塔河油田奥陶系碳酸盐岩储层主要储集空间为溶洞和裂缝,直接钻遇溶洞比例达50%。针对目前远井储集体特征认识模糊、动用难度大等问题,基于物质平衡原理及注水指示曲线、液面恢复曲线等资料,对远井储集体的规模、裂缝导流系数、地层能量进行定量化研究,形成了一套远井储集体参数定量化表征技术。基于远井储集体特征,运用酸化、高压注水、复合措施等方法提高对远井储集体的动用,并在塔河油田推广应用,高效井占75%以上,有较好的应用前景。     

融合高时空分辨率数据估算植被净初级生产力

植被净初级生产力NPP(Net Primary Production)遥感估算与分析,有赖于高时空分辨率的遥感数据,但目前中高分辨率的遥感数据受卫星回访周期及天气的影响,在中国南方地区难以获取连续时间序列的数据,从而影响了高精度的区域植被净初级生产力的遥感估算。为此,提出一种基于多源遥感数据时空融合技术与CASA模型估算高时空分辨率NPP的方法。首先,利用多源遥感数据,即Landsat8 OLI数据与MODIS13Q1数据,采用遥感数据时空融合方法,获得了时间序列的Landsat8 OLI融合数据;然后,基于Landsat8 OLI时空融合数据,并采用CASA模型,以长株潭城市群核心区为例,进行区域植被NPP的遥感估算。研究结果表明,基于时间序列Landsat融合数据估算的30m分辨率的NPP具有良好的空间细节信息,且估算值与实测值的相关系数达0.825,与实测NPP数据保持了较好的一致性。     

克拉玛依油田二厂八区套管破损机制研究

克拉玛依油田二厂八区井区经过长期开采出现了大量的套管破损问题。对套管破损位置进行总结归纳发现,套管破损主要存在于白垩系吐谷鲁群、侏罗系齐古组、二叠系乌尔禾组等地层中。对研究区连井进行地层对比、地震数据体进行波阻抗反演和砂体分析,发现研究区内白垩系吐谷鲁群和侏罗系齐古组的砂体十分发育,广泛存在于整套地层中。砂体中流体的渗流作用对套管的腐蚀为套管破损的主要因素。泥岩吸水蠕变膨胀、油层出砂和固井质量不合格为套管破损的其他因素。     

Correlations Between Biogenic Components and Dust Input and Their Change Mechanism on Hess Rise,Central North Pacific,During the Late Quaternary*

The study of marine export production is helpful to trace the changes of oceanic and global carbon reservoirs. Dust input is an important factor inspiring marine export production. Measurements of carbonate, Opal, TOC and C_org/N were performed on Core SO202-37-2, which was retrieved from Hess Rise, central North Pacific during the German SO202-INOPEX Expedition, for reconstructing variations of the local export production and dust input. The core age model is constructed via morphologically correlating its foraminifer oxygen isotope record with those of Core H3571 and the LR04 stack. XRF-Ti/Ca can be used as a proxy for dust input and its distribution pattern is consistent with that of Opal content, possibly indicating that dust input may have affected the local export production, i.e. the local export production increased (decreased) with enhancing (declining) dust input during interglacial (glacial) periods. Fluctuations in dust input might be due to southward/northward migration of the Westerly Jet over the dust source regions during interglacial and glacial periods. Although global dust output increased during glacial periods, meridional migration of the Westerly Jet in this area made the distribution pattern of the dust deposition in the study area different from that of other areas.     

基于北斗LBS技术的新疆地理国情普查安全生产监控系统的设计研究

在荒漠或人烟稀少地区,需要先进的应急救援管理手段来保障野外测绘作业人员的生命安全,基于北斗卫星导航系统的LBS技术能够解决安全生产问题。本文在分析新疆地理国情普查安全生产监控系统建设总体结构的基础上,阐述了其设计方案和安装部署,并探讨了系统各功能的实现方法,并验证了该系统能够为野外作业人员的位置定位、报警及指挥中心的监控和应急救援发挥作用。     

北斗二代卫星导航系统在生产车辆管理中的应用

北斗二代卫星导航系统是我国自主实施、独立运营的卫星导航系统。具有独特的优势和广阔的应用前景。基于北斗二代卫星导航的应用开展得如火如荼。本文正是以此为契机,通过分析现行生产车辆管理现状,尝试北斗二代卫星导航系统在生产车辆管理中的应用,满足本单位对生产车辆的管理要求,也为其他政府、企业及个人用户提供应用示范。     

文化旅游地空间生产背景下居民社会空间感知模型与实证研究——基于对周庄古镇的调查

在田野调查基础上,采用SPSS 18.0和AMOS 17.0数据统计软件对周庄文化旅游地空间生产背景下的居民社会空间感知进行了统计和处理,通过探索性因子分析和验证性因子分析,对居民社会空间感知模型以及不同职业和类型居民感知差异进行了测度研究,结果显示:①周庄居民社会空间感知总体上存在由利益关联、价值效能和情感眷恋组成的三维结构.②在感知次序上,呈现“利益关联→价值效能→情感眷恋”递减分异规律,本质上反映了深层结构是一种经济表层→社会感知→心理感知从外而内的感知规律.居民并未因具有参与旅游开发的机会权能而表现出对旅游开发的全面认同,在社会认同感知和心理认同感知层面还未得到深入,反映的居民社会空间感知是一个充满矛盾的感知结构.③不同职业和类型居民因参与旅游内容或程度不同对三维结构同样存在依次递减的分异规律,且每类群体间存在差异状态.研究认为,高质量的社会空间感知具有认知结构的全面性,居民社会空间感知结构的不平衡性对增进旅游空间生产的社会凝聚力提出新的诉求,提高居民空间参与程度和感知需要从有限参与→发展参与→充分参与的路径逐步改善.研究对周庄古镇旅游理性发展和可持续发展具有一定启发.     

Moving players,traversing perspectives: Global value chains,production networks and Ghanaian football labour migration

This article examines the production and transnational export of Ghanaian football labour. It does so via a cross-disciplinary approach that utilises perspectives rooted in the sociology of development (global value chains) and economic geography (global production networks). The article is underpinned by two central arguments. Firstly, it contends that the GVC framework is useful in accounting for how Ghanaian players are produced and prepared for the international market, identifying the key agents and agencies involved, mapping the geography of production and export and assessing the institutional context within which the trade operates locally, nationally and internationally. The second draws on the GPN perspective to argue that while Ghanaian football labour migration remains a process contoured by uneven asymmetries of power that favour actors, stakeholders and entities in the global North, there are currently segments of the production–export chain where power is much more diffuse and some benefits are captured in the global South. The paper draws on interview data and observations gleaned from four periods of multi-sited ethnographic fieldwork in Ghana between January 2008 and June 2011.