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481.
丽江为滇西北重镇,旅游资源十分丰富,是云南省旅游重点开发区,具有山岳冰川、高原地质生态、大峡谷、丹霞地貌、河流袭夺湾、卡斯特等六大景观类型,誉为地质生态博物馆。加快丽江旅游地质资源的勘查和开发利用,对民族地方经济发展有举足轻重作用。 相似文献
482.
Designing effective mitigation policies for greenhouse gas (GHG) emissions from agriculture requires understanding the mechanisms by which management practices affect emissions in different agroclimatic conditions. Agricultural GHG emissions and carbon sequestration potentials have been extensively studied in the Mediterranean biome, which is a biodiversity hot spot that is highly vulnerable to environmental changes. However, the absolute magnitude of GHG emissions and the extent to which research efforts match these emissions in each production system, are unknown. Here, we estimated GHG emissions and potential carbon sinks associated with crop and livestock production systems in the Mediterranean biome, covering 31 countries and assessing approximately 10,000 emission items. The results were then combined with a bibliometric assessment of 797 research publications to compare emissions estimates obtained with research efforts for each of the studied items. Although the magnitude of GHG emissions from crop production and the associated carbon sequestration potential (261 Tg CO2eq yr−1) were nearly half of those from livestock production (367 Tg CO2eq yr−1), mitigation research efforts were largely focused on the former. As a result, the relative research intensity, which relates the number of publications to the magnitude of emissions, is nearly one order of magnitude higher for crop production than for livestock production (2.6 and 0.4 papers Tg CO2eq−1, respectively). Moreover, this mismatch is even higher when crop and livestock types are studied separately, which indicates major research gaps associated with grassland and many strategic crop types, such as fruit tree orchards, fiber crops, roots and tubers. Most life cycle assessment studies do not consider carbon sequestration, although this single process has the highest magnitude in terms of annual CO2eq. In addition, these studies employ Tier 1 IPCC factors, which are not suited for use in Mediterranean environments. Our analytical results show that a strategic plan is required to extend on-site field GHG measurements to the Mediterranean biome. Such a plan needs to be cocreated among stakeholders and should be based on refocusing research efforts to GHG balance components that have been afforded less attention. In addition, the outcomes of Mediterranean field studies should be integrated into life cycle assessment-based carbon footprint analyses in order to avoid misleading conclusions. 相似文献
483.
The Field Research Center (FRC) including five contaminated sites and a clean background area was established in Oak Ridge,
Tennessee, as a part of the U.S. Department of Energy’s Natural and Accelerated Bioremediation Research (NABIR) program. This
study investigates the mineralogy and mineralogical pathways of saprolite at the FRC background site to provide a fundamental
basis for the remediation strategy for contaminated sites. The background site is underlain interbedded shales, siltstones,
and limestones with nearly identical characteristics to the contaminated sites. Bulk samples of saprolite were collected by
hand picking approximately at 1 m depth (C horizon) from the soil surface. The soil pH of 4.3 and cation exchange capacity
(CEC) of 10.5 cmol/kg measured are in the range of the typical shallow depth saprolite layer in this area. Total Fe by citrate-bicarbonate-dithionate
(CBD) and ammonium oxalate extractable (amorphous) were 17.6 and 0.61 g/kg, respectively. Total Mn extracted by NH2OH·HCl was 0.17 g/kg. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses indicate that quartz, illite,
and microcline (K-feldspar) are the dominant minerals, occupying 95% of mineral composition. The saprolite samples analyzed
have shown characteristics of oxic conditions overall, and the degrees of weathering for three sampling locations were various,
most for S1 and least for S3, likely influenced either by the flow channels developed through saprolite or by seasonal fluctuation
of the groundwater table. The source of the manganese oxide that observed from the site is likely to be Mn-rich muscovite
in the shale or Mn-rich biotite in the blackish band in the limestone. The results such as abundant Mn and Fe contents identified
encouraging prospects for conducting remediation projects in FRC sites. 相似文献
484.
《Geoforum》2017
The Generation Challenge Programme (GCP) was an international agrarian knowledge-production programme created in 2003 by the CGIAR. GCP aims at developing drought tolerant varieties by reconciling upstream biotechnology based advanced research with the downstream development at the farmer's field. The objective of this paper is to apply the theory of Commons Based Peer Production (CBPP) to analyse the knowledge production process of GCP, especially the case of drought tolerant rice research network in Indian context (GCP-RRN). CBPP represents the theorisation of a mode of production that can be distinguished from market (private) and state (public) knowledge-production systems that was developed by observing the phenomena of Free and Open Source Software (FOSS). The organisational attributes of the CBPP mode applied in computer software production include the modulation of work, small-size granularity of components, and mechanisms that integrate these modules into an end product. Socio-economically, this form of production is based on cooperation, collaboration and collective action rather than property, contract and managerial hierarchies. This paper argues that GCP-RRN knowledge production is basically a hybridised one in which there are certain inclinations towards CBPP within certain larger context, and there are other attributes too that do not fall within CBPP theorisation. Further, this paper elaborates on the implications of this hybridised model for agrarian knowledge production discourse and institutions. 相似文献
485.
This paper analyses the experiences acquired through several research projects on the history of water and sanitation services by two multidisciplinary teams. Challenges have been faced in identifying feasible objectives, realistic resources, time allocations and unexpected external factors. Water history can preserve cultural heritage, promote reputation management, record vanishing knowledge, and discover new facts. 相似文献
486.
中国结构控制的研究与应用 总被引:25,自引:6,他引:25
建筑结构传统的设计方法是依靠结构自身的能力耗散振动能量,近十几年来,减小建筑结构在强烈地震地面运动和风荷载作用下的损失,越来越引起科学家和工程师的关注。结构振动控制的研究和应用已经取得了可喜的成果,迄今为止,许多振动控制的方法已经成功地应用于实际工程中,本文的目的是回顾中国振动控制在土木工程结构中的研究和应用情况。其中包括:基础隔震和被动控制技术,主动控制,混合控制和半主动控制以及国家自然科学基金 相似文献
487.
488.
489.
北方中新生代产铀盆地的特点与找矿方向探讨 总被引:3,自引:0,他引:3
根据北方主要中新生代盆地的沉积演化特征,结合北方地区已知产铀盆地的特点,通过对航空物探测量成果资料的分析,建立了找矿选区依据;通过初步分析,指出了北方主要中新生代盆地砂岩型铀矿的找矿方向。 相似文献
490.
2005年夏,一个先进的海洋观测网络——包括实时的光纤海洋观测系统和内部存储的自动化观测系统——被投放在了阿曼海和北阿拉伯海并运行至今.在2010年初,其中的自动化观测系统被升级到了新的深水光纤观测系统.这个海洋观测网络是在阿曼农业和渔业部的资助下,由美国的Lighthouse R&D公司设计、开发、安装和维护的.这2个观测系统作为一个整体已经连续工作了7年多的时间.所采集数据包括海流、温度、盐度、压力、溶解氧和浊度等.该海区是一个多水团的汇合区,波斯湾的高盐水和阿拉伯海的低盐水在这里汇合并蔓延南下到印度洋.对采集的数据研究表明,这一观测网络对研究该区域的物理和生物过程具有重要价值.在此,将系统介绍整个观测网络,并简要阐述已经完成和接近完成的4个研究主题:①对阿拉伯海有记载以来最强热带气旋“古怒”的海洋响应的研究;②阿曼海北部的季节性缺氧现象的季节及年际变化和成因分析;③深海声散射层的时空演变;④阿曼海和北阿拉伯海的高温高盐现象的成因.该观测网络采集的长期、连续的时间序列对这一地区的海洋动力研究、水文的季节性变化,以及气候的长期变化等研究都有很大帮助.此外,如果观测网络可以完成25年的设定观测目标,这将对验证和改进海洋环流模式和海气耦合模式具有重要意义. 相似文献