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1.
从量子力学的形成和发展过程可以看到知识移植对物理学的发展起到了巨大的推动作用,通过知识移植不仅能够实现创新,甚至可能导致科学的重大发现。如何在教学活动中通过对科学史的总结和归纳来引导学生形成创新意识在当前我国的大学教育必须加以关注。  相似文献   
2.
ABSTRACT

There is a great conviction that the International Court of Justice’s ruling in 2002 on the Bakassi boundary dispute between Nigeria and Cameroon, and Nigeria’s decision to obey the ruling may have stopped a fierce inter-state war over the boundary. Indeed, many then ascribed to the whole boundary demarcation process as peacebuilding, disregarding the structural changes marked by the violence of forced migration. This article explores how the boundary delimitation has produced particular sorts of structural violence characterised by state neglect, loss of livelihoods and destitution. Thus, the article argues that although a full-blown war was avoided, the socio-economic conditions of the Nigerian populations on both sides of the border were not adequately considered and guaranteed as part of the peace-building agenda. It further argues that Nigeria, like many post-colonial states with the concentration of developments in major cities, neglects rural and border communities. Thus, the border communities accommodating the former Bakassi residents have further degenerated into ‘ill-governed’ spaces. This article uses structural violence as a framework to analyse the primary and secondary data to provide some deeper insights into the issues of violence being experienced by the local populations living on both sides of the demarcated border.  相似文献   
3.
在基于SAR回波的数据处理中,多普勒调频率具有很高的估计精度且对场景的依赖性很小,可以更广泛地用于自聚焦处理。基于多普勒调频率参数估计,针对回波包络及相位分别提出了误差提取模型,并通过包络误差校正和相位误差补偿两个步骤实现了高精度的运动补偿处理。实测数据表明,本文方法可以在低精度导航信息情况下获取高分辨率雷达图像。  相似文献   
4.
    
Abstract

Pastoralist groups in Eastern Africa are extremely vulnerable as a result of inter-community conflicts, the harsh terrain, and unfavourable climatic conditions. They have been neglected by successive regimes on matters of socio-economic development. At present pastoralist areas in Eastern Africa have the lowest literacy rates and insufficient health care facilities. This article interrogates the historical relationship between governments, humanitarian groups and pastoralists. It notes with great concern that pastoralists have been branded as hunger-stricken populations with insignificant economic potential that can be harnessed from their day-to-day livelihood. They are treated as sedentary populations who need a constant supply of relief food to keep going. In order to reverse these misconceptions, the article places emphasis on mitigating the threats of intra-community conflicts, diseases and natural disasters through investment in social schemes and infrastructure in order to open up the areas for service provision. Indeed, for a majority of the pastoralists, insecurity comes not so much from traditional security concerns, but from human insecurity concerns about their survival, preservation of their lifestyle and well-being in a day-to-day context.  相似文献   
5.
基于联合相似测度的SAR图像边缘点特征配准方法   总被引:1,自引:1,他引:0  
针对SAR图像配准过程中几何变换影响特征匹配稳健性和适应性的问题,提出了一种在特征匹配过程中直接解算几何变换模型的边缘点特征配准方法。利用SAR图像边缘点的梯度和方向特征,基于像素迁移思想,定义了图像匹配的联合相似度——联合特征均方和(SSJF),并建立了SAR图像边缘点集相似性匹配准则;基于方向模板提出了改进的ROEWA算子;利用改进的遗传算法(GA)来进行相似度的全局优化搜索,获取配准模型参数;利用多幅SAR图像的配准试验,对本文方法的性能进行了验证。  相似文献   
6.
近年来,扫描单发单收面阵近场成像技术在安检、医疗等民用领域中引起了广泛关注.然而,传统的距离徙动算法在对回波进行处理的过程中无法避免多步近似和插值操作,并且忽视了信号传播衰减带来的不利影响.因此,提出了一种基于快速傅里叶变换的扫描单发单收面阵近场成像技术,该技术通过保留回波模型中的幅度衰减因子,并根据目标回波方程特性对...  相似文献   
7.
    
What are relationships between epidemics, national security, and US immigration policy? This question is important because it sheds light on transnational or nontraditional security areas, American immigration policy, and a pressing issue for US leaders who have recently faced epidemics such as the West Africa Ebola outbreak that began in 2013. This article answers it and lays ground in the area by reviewing epidemics in world history, using International Relations and Security Studies works to specify dangers of contagions for states, and identifying three general immigration measures that American leaders have utilized from the seventeenth century to the present day to protect against contagions, which are (1) policies restricting entrance of foreigners thought to carry specified diseases, (2) the isolation or quarantining of immigrants with contagious disease, and (3) delegating the President with authority to stop immigration in the event of an epidemic abroad. This study has implications for research and contemporary US immigration policy.  相似文献   
8.
    
Abstract

We estimated a stochastic growth model for Sri Lanka over the 1962–2015 period and found that permanent productivity shocks constituted the largest proportion of the variance in output growth. We computed correlation coefficients between permanent productivity shocks and some variables and found a negative correlation between the shocks and the growth in migration outflows. The findings are consistent with the negative effect of civil war on economic growth from an exodus of skilled workers. We further investigated the factors that drive migration from Sri Lanka to a major migration destination, namely Australia, for educated and skilled Sri Lankans. We regressed the growth rate of the Sri Lankan-born population in Australia on a civil war dummy variable, per worker Australian gross domestic product (GDP), adjusted for the restrictiveness of Australian immigration policy and an estimated labour wedge that represents labour market inefficiency in Sri Lanka. We found that Sri Lankan immigrants in Australia increased with per worker GDP in Australia, civil war and labour market inefficiency in Sri Lanka. The finding suggests that excessive protection of insiders in the Sri Lankan labour market should be abolished to mitigate migration outflows that have continued since the end of the civil war.  相似文献   
9.
基于兴趣域的\"快递式\"动态负载平衡算法从HLA/RTI提供的服务出发,当节点成为重载节点时,将节点部分负载转移到兴趣域内的轻载节点上,同时采用两次\"握手\"方式解决了负载迁移过程中出现的问题.通过使用两个评价参数--CPU占有率和内存使用率进行实验证明,负载平衡前后重载节点的CPU利用率和内存使用率有明显差别,结果表明该方法能有效地平衡系统各节点之间的负载,保证系统的实时性,提高系统的服务质量.  相似文献   
10.
主要研究了动基线时差测量系统采用多脉冲相参积累算法对低信噪比条件下运动目标的有效检测问题。通过分析雷达回波信号的特性,指出目标高速运动所引起的包络走动是影响积累性能的主要因素。选用了插值补偿包络走动后进行相参积累的算法。仿真结果表明,在低信噪比条件下,插值补偿相参积累算法能实现对运动目标弱小信号的有效检测,其积累性能优于未做补偿积累算法的性能。  相似文献   
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