oalib

OALib Journal期刊

ISSN: 2333-9721

费用：99美元

投稿

时间不限

( 2026 )

( 2025 )

( 2024 )

( 2023 )

自定义范围…

匹配条件： “pénurie” ，找到相关结果约1000条。
列表显示的所有文章，均可免费获取
第1页/共1000条
每页显示 条
Food rationing during World War two: a special case of sustainable consumption? Rationnement alimentaire pendant la seconde guerre mondiale : Un cas particulier de consommation durable ?
Iselin Theien
Anthropology of Food , 2009,
Abstract: This article explores some of the strategies applied by consumers for making-do during the Second World War in Norway. By reducing waste, using various substitutes and exploiting underused natural resources such as wild plants, birds, and alternative marine sources of nutrition, Norwegian consumers adapted their diet to a situation of food scarcity. However, their everyday consumption was primarily governed by the regulatory framework installed for dealing with the crisis, namely the rationing system. By 1942, almost all common foods had been placed under rationing. Despite of the many bureaucratic inconveniences of this system, it was largely supported by consumers, who accepted it as a socially just mechanism for distributing scarce resources. The article brings up the question of how far the willingness of consumers to accept rationing was a unique experience of the war, or whether one might imagine a similar design for purposes of sustainable consumption. Cet article explore quelques unes des stratégies utilisées par les consommateurs pour survivre pendant la 2è guerre mondiale en Norvège. En limitant les déchets, en utilisant des produits de substitution ainsi que les ressources de la nature telles que plantes sauvages, oiseaux et aliments marins alternatifs, les consommateurs norvégiens ont pu adapter leur alimentation à cette période de pénurie alimentaire. La nourriture quotidienne était toutefois essentiellement encadrée par la réglementation mise en place afin de faire face à la crise, c’est à dire le système de rationnement. En 1942, presque tous les aliments étaient rationnés. En dépit de ses nombreux inconvénients administratifs, le rationnement fut quand même soutenu par les consommateurs, qui l’acceptèrent comme un système socialement équitable pour la distribution des maigres ressources. L’article développe la question suivante : l’acceptation du rationnement par les consommateurs norvégiens est-elle liée uniquement à la période de guerre, ou bien pourrait-on imaginer un système similaire pour favoriser une consommation durable?
Расселение населения в Прикаспийском регионе
Ismailov, ？ingiz
- , 2002,
Abstract: Sa？etak Статья посвящена особенностям расселения населения в приморских районах Прикаспийского региона. Исторический экскурс в прошлое региона свидетельствует о сложных переплетениях судеб народов, ныне расселяющих приморские районы Каспийского моря. Начиная с ХХVIII века начинается период проникновения России в приморские районы Каспийского моря и противоборства с Ираном в регионе. С этой целью по указу Петра Первого в приморских районах начинается закладка сторожевых укреплений, которые в дальнейшем превращаются в населенные пункты (Форт-Петровск, Форт-Шевченко, Красноводск и другие). Развитие населенных пунктов в приморских районах способствовало расширению сети транспортных коммуникаций. При этом проявились территориальные различия в уровне развития отдельных видов транспорта. Такое положение во многом определялось особенностью экономико-географического положения отдельных участков приморских районов Прикаспийского региона. Для оценки плотности населения в приморских районах важным методологическим подходом является делимитация границ приморских районов. С этой целью проанализированы применяемые подходы для выявления рисунка районов расселения населения в приморских районах. В этом отношении выделено несколько прибрежных полос, отличающихся различием в степени аттрактивности территории. В силу природно-климатических условий и степени освоенности приморские районы Прикаспия различаются по степени развития городских поселений. Наиболее высокой степенью урбанизации отличается приморский участок Азербайджана, где находится самый большой по численности город в Прикаспийском регионе – г. Баку, с населением более 2 млн. человек. Сравнительная характеристика расселения населения в приморских районах стран Прикаспийского региона показывает, что наибольшее количество населения сосредоточенно на иранском участке побережья, а наименьшее – на туркменском участке. При этом в наиболее заселенных участках (иранском и азербайджанском) доминирующим типом расселения является площадное, в противоположность чему, в наименее заселенных участках (туркменском иказахском) характерными являются дисперсный и очаговый типы расселения
氮磷添加对刨花楠幼苗叶片N、P化学计量特征的影响*
应用与环境生物学报 , 2016, DOI: 10.3724/SP.J.1145.2015.06022
Abstract: 以刨花楠（Machilus pauhoi）幼苗为研究对象，通过盆栽施肥试验，探讨不同氮（N）、磷（P）供应水平下刨花楠叶片N、P元素含量的动态变化及与土壤养分的相关性. N、P处理各设定4个梯度，N1、N2、N3、N4及P1、P2、P3、P4，N、P肥施加量分别是初始土壤的2倍、4倍、8倍和16倍，不同N、P处理共用一组对照（CK），共9种处理，每组处理3个重复，并分别于3月、7月、11月对成熟叶片及土壤进行采样分析. 结果显示：刨花楠幼苗叶片N、P含量及N:P值分别为14.63-26.53 mg/g、0.64-1.84 mg/g和10.04-23.21. 施N肥叶片N含量及N:P随季节变化呈现出低（3月份）―高（7月份）―低（11月份）的变化趋势，叶片P含量呈现高―低―高的趋势；施P肥叶片P含量也随季节变化呈现出先升高后降低的变化趋势. 施N或施P显著增加了刨花楠幼苗土壤及叶片的N、P含量，分别增加或降低土壤及叶片的N:P值（P < 0.05）；施N或施P也显著影响了土壤pH（P < 0.05）及叶片N、P含量与土壤养分的关系. 综上表明土壤中N、P供应量影响刨花楠叶片中的N、P含量. （图3 表2 参43
Phosphorus fixing capacity of the Oxic Rhodustalf—alfisol soil in the Chotanagpur plateau region of Eastern India  [PDF]
Prabir Ghosal, Trishit Chakraborty, Pabitra Banik
Agricultural Sciences (AS) , 2011, DOI: 10.4236/as.2011.24062
Abstract: The P-fixing capacity of a soil governs the P-nutrition of crop plants. P-nutrition of the crop plant is more a soil problem and a higher dose of phosphatic fertilizer is necessary for soils having high P-fixing capacity. The phenomenon of P-fixation and the great variation in the P-fixing capacity of different soils has thus important bearing on crop response to P-application. The eastern plateau region of India with acid lateritic soil is chronically deficient in available phosphorus resulting in very low productivity. An experiment was thus carried out to estimate the P-fixing capacity of soil collected from two depths, 0 - 20 cm and 20 - 50 cm, from the Agricultural experimental farm of Indian Statistical Institute, situated at Giridih, Jharkhand, in the eastern India. The soil was acidic in reaction (pH-5.4) with presence of Fe (1.60%) and Al (17.2%). The P-fixing capacity of the soil was estimated to be 59.60% and 64.94% for the surface and the subsurface soil respectively showing lower P-fixing capacity of the surface soil as compared to the subsurface soil which may be due to presence of more organic matter in the surface soil as organic molecules released on decomposition of organic matter complexes with Fe and Al in the soil thereby blocking the P-fixing sites in the soil.
Discussion of the Risks and Risk Control of P2P in China  [PDF]
Xue Lei
Modern Economy (ME) , 2016, DOI: 10.4236/me.2016.74043
Abstract: As a kind of finance innovation for direct lending between individuals, P2P develops rapidly in recent ten years. However, while it is promoting China’s economic development, various problems related to P2P network credit and loan are appearing gradually. If P2P wants to develop continuously, the core is to strengthen the risk management. Based on the analysis of the concept, model and positive significance of P2P network credit and loan, this paper mainly expounds the credit risks, information risks, operational risk, regulatory and legal risks and liquidity risk that P2P network credit and loan faces, and comes up with the solutions to these problems, for example, setting up the credit system, perfecting internal control as well as strengthening supervision and industrial self-regulation, combining big data technology. These present some new ideas of performing risks management for P2P.
Extractable Phosphorus Contents of Some Soils of Bangladesh and Their Correlation with Phosphorus Concentration in Rice Leaves  [PDF]
Enamul Haque, Abul Kashem, Khan Towhid Osman
Open Journal of Soil Science (OJSS) , 2013, DOI: 10.4236/ojss.2013.32013
Abstract:

To observe the availability of phosphorus by different extraction methods in some cultivated soils of Hathazari Upazilla of Chittagong District, this study was carried out with 36 surface soil samples (0 - 15 cm) belonging to six soil series, namely Bijipur, Pahartali, Mirsarai, Manu, Raojan and Noapara. Physical and chemical characteristics of the soils were also determined with an objective of identifying the soil factor(s) regulating P extractability. Three P extraction methods, namely Olsen (0.5 M NaHCO3, pH 8.5), Mehlich-3 (0.2 N CH3COOH + 0.013 N HNO3 + 0.015 N NH4F + 0.25 N NH4 NO3 + 0.001 M EDTA) and Bray & Kurtz-1 (0.03 N NH4F + 0.025 N HCl) were used. There was a wide variation in the extractability of P ranging from low to high categories. Olsen method extracted the largest amount of P (2.07 - 45.36 mg·kg-1) while Bray & Kurtz-1 extracted the smallest amount (1.02 - 21.79 mg·kg-1). The mean extractable P in soils was found to be in the order of Olsen > Mehlich-3 > Bray & Kurtz-1. Soil pH was the most dominant factor in determining P extractability. Available P was negatively correlated with

P2P平台融资业务风险控制的探讨
Discussion on Risk Control of P2P Financing  [PDF]
邹德军
E-Commerce Letters (ECL) , 2014, DOI: 10.12677/ECL.2014.34006
Abstract:
随着P2P平台融资业务的快速发展，风险控制成为关键领域。许多学者对P2P平台融资业务开展了有益探索，提出了信用风险、市场风险等要素。在具体实务工作P2P平台也采取了线上认证、线下考察等风险控制手段。P2P平台融资业务风险控制需要国家建立信用评级体系、健全监管制度，同时需要P2P平台加强贷前审核，利用网络大数据分析降低融资业务风险。
With the rapid development of the P2P financing, its risk control becomes the key area. Many scholars have carried out exploration into the risks of the P2P financing, including the credit risk, market risk and so on. In practice, the P2P has taken means to control risks such as the on-line certification and off-line investigation. Government shall establish the credit rating system and improve the supervisory system to control risks of P2P financing and the P2P shall reduce the fi-nancing risks through strengthening the pre-lending review and analyzing the network mass data.
Distribui？？o de fósforo em diferentes ordens de solo do semi-árido da Paraíba e de Pernambuco
Silveira, Mailze Maria Lins da;Araújo, Maria do Socorro Bezerra;Sampaio, Everardo Valadares de Sá Barretto;
Revista Brasileira de Ciência do Solo , 2006, DOI: 10.1590/S0100-06832006000200009
Abstract: most soils in semi-arid northeastern brazil are considered phosphorus deficient. the great diversity of orders they belong to, however, indicates that they are not similar in relation to the concentrations of their different p forms. the distribution of phosphorus forms in 69 soils of the most common soil orders in the semi-arid region was evaluated in samples from the 0-20 and 20-40 cm soil layers. phosphorus was determined by mehlich-1 and by a sequential fractionation, through extractions with resin, nahco3, naoh and h2so4, followed by peroxide/sulfuric digestion. total p (the sum of all fractions) varied from 52 to 1625 mg kg-1. most soils were in a range from 100 to 200 mg kg-1 in the 0-20 cm layer, with a large variability between and within soil orders. large variability was also observed for all p fractions. in general, fluvic neossols, vertisols, luvisols and cambisols had the highest total p values; argisols, litholic neosols and latosols, intermediate values; and regolitic neosols, planosols and quartzarenic neosols, the lowest values. the largest proportions of total p were in the residual fraction and the smallest in the labile fractions (resin-p and nahco3-pi), which together represented 7-12 % of total p. mehlich-1 extracted low proportions of p from vertissols (1 %) and high proportion from latosols (24 %), while the opposite was true for bicarbonate extraction (11 and 5 %, respectively). resin extracted low proportions from all soil orders (1 to 6 %).
Design and Implementation on the P2P VOD System Based on the RF-IPS Algorithm  [PDF]
Zhiyi Qu, Lili Li, Jianxu Li
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.39099
Abstract: This paper presents a P2P VOD system based on RF-IPS algorithm, and this system consists of two parts, server-side and clients. We put emphasis on the piece selection module of server-side, and in this part we cite the RF-IPS algorithm proposed in the past. In the piece selection module, we also proposed a weighting function except the RF-IPS algorithm. Using this function we will find the best server peers effectively and quickly, it will enhance the performance of this system. We carry on experiments on RF-IPS algorithm, and the results show this algorithm is efficient. Overall, we believe that the RF-IPS algorithm is feasible to further improve system performance and provide a cost-effective P2P VOD service with acceptable user experience.
A Measurement Study on BitTorrent System  [PDF]
Lin Ye, Hongli Zhang, Fei Li, Majing Su
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.312125
Abstract: Measuring and characterizing peer-to-peer (P2P) file-sharing systems will benefit the optimization and management of P2P systems. Though there are a lot of measurement studies on BitTorrent almost in every important aspect, few of them focus on the measurement issues and the corresponding solutions, which can strongly influence the accuracy of measurement results. This paper analyzes the key difficulties of measuring BitTorrent and presents a measurement system with combination of active and passive ways, which can han-dle with the problems well and balance the efficiency and integrity. Then compared to other work, a more complete and representative measurement was performed for nearly two months and several characteristics are concerned: 1) there are diverse content sharing in BitTorrent system, but multimedia files that are larger than 100 MB are the most. 2) Distributed Hash Tables has indeed enhanced the ability of peer discovery though there are some pitfalls to be addressed. 3) Pieces are distributed uniformly after the early stage and there are few rare pieces. Furthermore, peer arrival rate shows a periodical pattern, which was not well mod-eled before. Then an improved model is proposed and the experiment results indicate that new model is fitted in with actual measurement results with high accuracy.
第1页/共1000条
每页显示 条


Home
Copyright © 2008-2020 Open Access Library. All rights reserved.