马里费鲁水电站工程设计综述

马里费鲁水电站位于非洲马里共和国境内的塞内加尔河上,是一座径流引水式发电站,总装机容量为3×21MW。文中介绍水电站的总体布置和各分项设计情况。项目建设资金通过向世界银行和欧洲投资银行贷款,因此,采用国际标准设计,设计流程符合世界银行的要求。     

流态化及缓苏干燥技术对泰国香稻的香味和磨粉品质的影响

将高温（〉100。C）流态化干燥和缓苏相结合干燥泰国香稻（KhaoDawkMali105，籼稻），使其湿含量降至13-14％（湿基），以便于安全贮存。研究了干燥与贮存过程对籼米香味和磨粉品质的影响。泰国香稻需要经过两个干燥阶段。第一阶段是在高温流化床中干燥，缓苏30分钟，然后返回高温流化床干燥或阴干，直至湿含量降低到安全贮存水平。实验结果表明，干燥温度对香稻的整精米率（HRY）、白度指数（wI）和2AP含量均有影响。多数干燥温度下整精米率的水平都比较低，但150℃除外，此情况下整精米率（psO．05）显著提高。然而，当一次流态化干燥和缓苏之后，以阴干代替二次流态化干燥，香稻的整精米率显著增加，尤其是在135℃和50℃时（p≤O．05）。在贮存期间，白度指数和2AP舍量显著降低（ps0．05），而整精米率保持不变。对比环境温度（28．30℃）和15℃贮存温度，结果表明保持香米2AP舍量和白度指数的适宜保存温度是15℃。然而贮存条件对整精米率影响不大（p〉0．05）。本研究将有益于泰国香米行业的发展，为泰国香米的干燥起到指导性作用。     

Agricultural land investments and water management in the Office du Niger,Mali: options for improved water pricing

Large-scale agricultural land investments in Africa are often considered solely from the land perspective. Yet land, water and other natural resources are closely interlinked in agricultural production and in sustaining rural livelihoods. Such investments involving irrigation will potentially have implications for water availability and utilization by other users, making it imperative to regard water as an economic rather than a free good. Focusing on a vast irrigable area in Mali with recent large-scale investments, a bio-economic model was used to demonstrate that an improved water valuation system is needed to balance different water users’ needs while ensuring adequate environmental flow.     

Farmers' perceptions and attitudes towards introduced soil-fertility enhancing technologies in western Africa

Soil fertility enhancing technologies (SFETs) have been promoted in the West African Semi-Arid Tropics (WASAT) for many years with limited success. Using a qualitative approach of focus group discussions, long, open-ended interviews and observations from field visits, this paper explores with farmers their beliefs and rationales behind the adoption or non-adoption of SFETs. Farmers are knowledgeable about, and practise SFETs of rock phosphate application, crop residue and farm yard manure, chemical fertilizer and crop rotation to combat soil fertility decline. Their attitudes to and rationales behind adoption decisions are influenced by the availability and use policies of land and labour resources, food security concerns, perceived profitability, contribution to sustainability and access to information. Some of the factors are beyond farmers' control and require a broad and integrated effort from research, extension and government to promote the use of the SFETs in the region.     

Linking Performance and Collective Action—the Case of the Office du Niger Irrigation Scheme in Mali

Increasing irrigation efficiency in irrigation schemes has always been high on the agenda of policy makers. Despite quite some ‘social’ experiments, whereby large portions of management were carried over to the farmer level, results often remained disappointing. This paper explores why this came about for a case study in the Office du Niger irrigation scheme in Mali. Since Irrigation Management Transfer, farmers are responsible for the tertiary level, but collective action for water management remains below expectations. This paper applies an analytical framework based on the conceptual model developed by van Noordwijk et al. (Conserv Ecol 5:21, 2002) and proceeding in two steps. Firstly, an interview-based stakeholder analysis assesses the objectives and mental models of farmers and the central management regarding water management. It appears from the interviews that the central management wants to increase irrigation efficiency through fully-fledged collective action, whereas farmers value the latter only when it favours easy irrigation. Secondly, the relation between collective action and performance was tested through a field study on a sample of 36 tertiary blocks. Results indicate that only collective action at the inlet of the tertiary canal, currently implemented on less than a third of the tertiary blocks, increases irrigation efficiency (with 14%). Collective action for water allocation is implemented within almost three quarters of tertiary blocks and effectively reduces irrigation problems. However, if they lack the necessary social capital, not all farmers can establish collective action when needed. Based on this analysis, the paper proposes a mix of incentives and measures to resolve the conflict between farmers and the central management to their mutual benefit.     

Selection of pfcrt K76 and pfmdr1 N86 Coding Alleles after Uncomplicated Malaria Treatment by Artemether-Lumefantrine in Mali

Background: Artemether-lumefantrine is a highly effective artemisinin-based combination therapy that was adopted in Mali as first-line treatment for uncomplicated Plasmodium falciparum malaria. This study was designed to measure the efficacy of artemether-lumefantrine and to assess the selection of the P. falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multi-drug resistance 1 (pfmdr1) genotypes that have been associated with drug resistance. Methods: A 28-day follow-up efficacy trial of artemether-lumefantrine was conducted in patients aged 6 months and older suffering from uncomplicated falciparum malaria in four different Malian areas during the 2009 malaria transmission season. The polymorphic genetic markers MSP2, MSP1, and Ca1 were used to distinguish between recrudescence and reinfection. Reinfection and recrudescence were then grouped as recurrent infections and analyzed together by PCR-restriction fragment length polymorphism (RFLP) to identify candidate markers for artemether-lumefantrine tolerance in the P. falciparum chloroquine resistance transporter (pfcrt) gene and the P. falciparum multi-drug resistance 1 (pfmdr1) gene. Results: Clinical outcomes in 326 patients (96.7%) were analyzed and the 28-day uncorrected adequate clinical and parasitological response (ACPR) rate was 73.9%. The total PCR-corrected 28-day ACPR was 97.2%. The pfcrt 76T and pfmdr1 86Y population prevalence decreased from 49.3% and 11.0% at baseline (n = 337) to 38.8% and 0% in patients with recurrent infection (n = 85); p = 0.001), respectively. Conclusion: Parasite populations exposed to artemether-lumefantrine in this study were selected toward chloroquine-sensitivity and showed a promising trend that may warrant future targeted reintroduction of chloroquine or/and amodiaquine.     

Soil nutrient depletion by agricultural production in Southern Mali

The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given.The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur.Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits.The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.     

马里金矿特征、成矿规律及找矿远景分析

马里是非洲第三大产金国,位于西非克拉通和图阿雷格地盾核部之上。文章通过对马里金矿资源的介绍,分析了马里金矿的分布特征和成矿规律。马里金矿床主要分布在南部比利姆群和西南部凯涅巴绿岩带上,类型主要为脉型金矿,其次为层控型金矿。从马里金矿成矿条件和分布规律上看,马里勘查金矿的有利靶区为西南部凯涅巴地区的绿岩带和南部布古尼地区的绿岩带。     

Spatial optimization of Jatropha based electricity value chains including the effect of emissions from land use change

Jatropha was identified as a potential feedstock to satisfy off-grid and on-grid energy solutions. However, the potential has been questioned due to agronomic frustrations, the lack of an organized value chain and heavy criticism on biofuels due to emissions triggered by land use change (LUC). To contribute to the realistic integration of Jatropha in rural development, this article proposes a modeling approach to probe the feasibility of Jatropha-based electrification in rural Africa and the layout of such a value chain.A multi-component modeling setup is presented, featuring a life cycle inventory, spatial modeling and the optimization model, OPTIMASS. In this modeling setup, OPTIMASS is parameterized with data regarding the global warming potential and the potential location of each operation in the value chain including cultivation sites and related LUC emissions. This enables OPTIMASS to spatially design the Jatropha-based on-grid and off-grid electrification value chain (i.e. cultivation, transport and storage, biofuel production and electricity generation) in Southern Mali with minimal GWP to reach 10% substitution of fossil fuels for Jatropha in electricity production for a current and two future electricity demand scenarios.Analysis of the optimization results demonstrates that emissions from transporting the oil are lower than LUC emissions per harvestable seed of other sites. Finally, it can be said that harnessing the entirety of the Jatropha value chain is crucial to make it GWP competitive relative to fossil fuels in which the location of plantations is crucial to attain low LUC-related emissions and viable yields.