共查询到20条相似文献,搜索用时 744 毫秒
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核聚变动力的应用将提供几乎是无限、清洁的新一代能源.当前已经看到受控热核聚变的科学可能性,在利用核聚变生产动力之前,还要解决其工艺技术可行性及经济竞争能力等问题.聚变裂变混合堆是改善其经济性和减少工艺技术难点的方向之一,还可创造一个核能利用的有效途径. An almost limitless and clean source of energy for future generation should be provided by the successful use of nuclear fusion for generating power.At present the scien-tific feasibility of controlled nuclear fusion is visible and before fusion can be harnessed for generating power,it will be necessary to develop suitable technology and to prove economic viability.The fusion-fission hybrid reactor is one way to improve the economy and to reduce the technological difflculties... 相似文献
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Hiroshi Takahashi 《Hyperfine Interactions》2001,138(1-4):365-371
A high-intensity neutron source that is highly correlated spatially and with time and will be used for neutron scattering
experiments can be obtained by dt m catalyzed fusion by enhancing the formation rate of dtμ molecules using a high-intensity
pulsed laser to dtμ gas. This paper considers the use of dtμ fusion for fast ignition of inertial confinement fusion, and
the possibility of ensuring energy balance in energy production. dt fusion can be quickly ignited by depositing dtμ fusion
energy into a smaller space than is done in other methods, such as Z-pinch or heavy-ion fusion. Space propulsion can be obtained
with a light fuel mass rather than by a fission repulsion system using the muons produced by annihilation of the anti-protons
stored in liquid superfluid of condensed He. Using an extremely highly compressed target can create a source of high luminosity
muons for muon–muon collider- and neutrino-oscillation experiments. This approach can eliminate the need for a super-conducting
solenoidal for capturing the beam of pions and muons generated in a large target, and then these pions and muons can be manipulated
by a laser beam instead of by employing RF manipulation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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丰中子核以及重核熔合机制的研究以及中能重离子碰撞中多重碎裂的研究都迫切需要一个统一的、自洽的微观动力学模型.经过对量子分子动力学模型进行根本的改进,发展了一个新的、适用于低能以及中能重离子反应的统一描述的微观动力学模型.改进的量子分子动力学(ImQMD)模型能够将整个熔合反应过程中的动力学效应、同位旋效应以及弹靶质量不对称效应等比较全面地、自洽地考虑进来,从而给熔合反应的研究提供了一个新的途径.ImQMD模型能够很好地再现一系列核的基态性质以及10多个熔合反应的激发函数(包括丰中子核熔合体系以及实验最新测量的132Sn+64Ni熔合体系).此外还运用该模型初步探索了重核熔合过程中复合体系的寿命与体系的入射能量、体系大小以及体系的中子质子比的依赖关系. We have developed a new microscopic dynamical model called improved quantum molecular dynamical model (ImQMD). This model can describe the fusion process at energies near the Coulomb barrier as well as the multifragmentation process at intermediate energies in heavy-ion collision (HIC) uniformly. By using this model, fusion cross sections (including some of neutron-rich nuclei reactions and that of newly measured~(132)Sn+~(64)Ni fusion reaction) of tens reactions can be reproduced remarkably well. In fusi... 相似文献
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利用新研制的聚变反应速率测量系统,在神光Ⅲ原型装置上测量了间接驱动时充DT气体的玻璃球壳内爆靶丸的聚变反应速率的时间历程,获得了DT中子产额约为1010时的聚变反应速率随时间的变化过程,发现了聚变中子发射在时间上的双峰结构。利用辐射流体程序对聚变中子在时间上的双峰结构进行了数值模拟,发现双峰结构分别由冲击压缩过程和惯性压缩过程产生,靶丸壳层厚度不同时产生的聚变中子发射双峰强度比变化可能是由靶丸的初始表面调制度不同所致。通过理论模拟与实验结果的对比,验证了中子聚变反应历程的双峰结构。 相似文献
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从跟踪性能、计算的复杂性以及应用范围等方面对红外与电视传感器的三种融合模型进行了比较,得出了来自同一平台上的红外与电视传感器的数据,在各传感器没有自己的数字处理机的情况下,点迹融合模型较其余两种模型实用的结论,在点迹融合模型的基础上,用极大似然融合算法对点迹进行融合处理,在理论上证明了该算法用于此种模型能提高目标状态信息的估计精度,降低测量误差。并给出了本算法用于此种模型在计算机上的仿真结果,从实际应用上进一步说明了本算法的有效性。最后利用卡尔曼滤波实现了红外与电视机动目标的跟踪。 相似文献
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《Physics letters. A》2001,289(3):135-140
The outcome of fusion burning waves in non-degenerate plasmas is limited by the strength of ion–electron Coulomb collisions and subsequent energy loss mechanisms as electron heat conduction and radiation emission. In this Letter, an analysis is presented on the degeneracy effects in the stopping power of suprathermal charged particles and in the energy transmitted from ions to electrons by Coulomb collision. Main results of this analysis is that very powerful fusion burning waves can be launched into previously compressed degenerate plasmas. This can be specially suitable for proton–boron fusion, but it also applicable to any type of fusion reaction, where ignition can be triggered by an incoming ion beam or another external source of energy deposited in a small fraction of the compressed plasma (fast ignition). 相似文献
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A novel video fusion framework based on the three-dimensional surfacelet transform (3D-ST) is proposed in this paper. Different from the traditional individual-frame based video fusion methods, the proposed framework fused multi-frame images of input videos as a whole rather than frame by frame independently with the 3D-ST. Furthermore, under the proposed framework, two ST-based video fusion algorithms are proposed. In the first algorithm, no special treatment is performed on the temporal motion information in input videos, and only a spatial-temporal region energy-based fusion rule is employed. While in the second algorithm, a modified z-score based motion detection is performed to distinguish the temporal motion information from the spatial geometry information, and then a motion-based fusion rule is present. Experimental results demonstrate that, with the motion selectivity of the 3D-ST, existing static image fusion rules can be extended to video fusion under the proposed framework. Both of the two proposed fusion algorithms significantly outperform some traditional individual-frame based and motion-based methods in spatial-temporal information extraction as well as in temporal stability and consistency. In addition, the second proposed algorithm is with high computation efficiency and can be applied to real-time video fusion. 相似文献
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Considerations based on the Maron theory show that for solutions of an amorphous polymer in a solvent the values of A obtained from heats of solution, heats of dilution, osmotic pressure, and vapor pressure should all be identical. Here λ = (aWaT)2, where μ is the Maron theory interaction parameter, T the temperature, and v2 the volume fraction. On the other hand, for solutions of a crystalline polymer in a solvent the A's obtained from heats of solution should always differ from those given by the other measurements. The difference is due to the heat of fusion involved in melting the crystalline portion of the polymer. A method is presented by means of which this heat of fusion can be found from the observed heats of solution, and this heat of fusion can either be used as a relative measure of crystallinity, or it can be converted to percent crystallinity when the heat of fusion of the completely crystalline polymer is known. The method described is very precise, and highly sensitive to low degrees of order. 相似文献
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针对现有融合方法不易根据后续处理目的对融合规则进行自适应调整,不同方法的优点不易综合的问题,提出一个基于数据同化和差分进化算法的图像融合框架.在该框架下,将基于非采样下的Contourlet变换作为模型算子,离散小波变换作为观测算子,可根据后续处理对图像各个属性指标值的依赖程度确定各个属性指标的权重,构造由图像各个属性评价指标的加权和所组成的目标函数,再利用差分进化算法来优化目标函数,从而获取更合适的图像.二组实验从视觉效果和量化指标(标准方差、平均梯度、熵、空间频率及均方根交叉熵)两方面验证了该框架的有效性. 相似文献
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由于可见光成像系统的聚焦范围有限,因而在成像过程中,除聚焦良好的物体能生成清晰的图像外,该物体前后一定距离外的所有物体都将呈现不同程度的模糊.为了获得场景内所有物体均清晰的图像,在分析了多聚焦图像成像机理的基础上,提出了一种基于小波包变换的融合方法.它是将成像系统先聚焦在一部分对象上,得到其清晰的图像;然后再将其聚焦在另一部分对象上,得到另一清晰的图像;最后把这两幅实验图像加以融合,从而获得场景内所有物体均清晰的图像.实验结果表明,基于小波包变换的融合方法能够将信号的频带进行多层次划分,对高频成分也能进一步地分解,可有效综合多聚焦图像. 相似文献
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Douglas L Sheridan Catherine H Berlot Antoine Robert Fiona M Inglis Klara B Jakobsdottir James R Howe Thomas E Hughes 《BMC neuroscience》2002,3(1):7-11
Background
The jellyfish green fluorescent protein (GFP) can be inserted into the middle of another protein to produce a functional, fluorescent fusion protein. Finding permissive sites for insertion, however, can be difficult. Here we describe a transposon-based approach for rapidly creating libraries of GFP fusion proteins. 相似文献16.
基于光纤拉锥模场匹配技术的光子晶体光纤低损耗熔接 总被引:1,自引:1,他引:0
光子晶体光纤(PCF)与普通单模光纤(SMF)的低损耗熔接技术是光子晶体光纤走向实用化必须解决的关键技术问题。提出一种基于光纤拉锥模场匹配技术的光子晶体光纤低损耗熔接的新方法,利用熔融拉锥机对模场不匹配的两类PCF进行预处理,结合常规电弧放电熔接技术对三种不同类型的PCF与SMF的熔接损耗进行实验研究。在实验中通过精确控制熔融拉锥机各种参数,实现了不同模场直径PCF和SMF的模场匹配,该方案同时通过优化各种电弧放电参数,使熔接后的损耗降到了0.3dB以下,实现了PCF-SMF之间低损耗、高强度的熔接,满足了不同模场PCF实际应用的要求,具有很好的潜在应用价值。 相似文献
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红外搜索系统作为被动式搜索系统,一般只能获得目标所处位置的方位角和俯仰角信息,缺乏距离信息,在无测距装置的条件下,只能依靠角度信息进行数据融合。依据角度值的三角函数关系,提出了一种新的分布式多传感器航迹加权融合算法,算法经仿真验证有效,降低了融合航迹的误差。在对量测数据进行误差修正的基础上,算法效果更加显著。 相似文献
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高分辨率遥感影像融合处理技术的对比分析研究 总被引:3,自引:1,他引:3
随着遥感技术的发展,获取遥感数据的手段越来越丰富。由各种不同的传感器获取的影像数据与日俱增,在同一地区形成了多时相、多分辨率的影像序列。如何综合各种类型的遥感影像信息,提高遥感数据的利用效益已成为遥感应用的瓶颈问题。多源遥感数据融合技术是解决这一问题的有效手段。高空间分辨率影像数据的多样性和复杂性对遥感信息融合处理技术提出了新的更高的要求。以IKONOS卫星数据为例对其进行了空间分辨率的影像融合。研究中引入了多种融合方法,如IHS变换、主成分分析、小波变换以及基于区域特征的自适应小波包算法。从光谱质量和空间信息的角度出发对融合方法进行了比较研究,分析出了比较适合于IKONOS卫星的高分辨率影像融合的处理方法。 相似文献
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In this paper, we design an infrared (IR) and visible (VIS) image fusion via unsupervised dense networks, termed as TPFusion. Activity level measurements and fusion rules are indispensable parts of conventional image fusion methods. However, designing an appropriate fusion process is time-consuming and complicated. In recent years, deep learning-based methods are proposed to handle this problem. However, for multi-modality image fusion, using the same network cannot extract effective feature maps from source images that are obtained by different image sensors. In TPFusion, we can avoid this issue. At first, we extract the textural information of the source images. Then two densely connected networks are trained to fuse textural information and source image, respectively. By this way, we can preserve more textural details in the fused image. Moreover, loss functions we designed to constrain two densely connected convolutional networks are according to the characteristics of textural information and source images. Through our method, the fused image will obtain more textural information of source images. For proving the validity of our method, we implement comparison and ablation experiments from the qualitative and quantitative assessments. The ablation experiments prove the effectiveness of TPFusion. Being compared to existing advanced IR and VIS image fusion methods, our fusion results possess better fusion results in both objective and subjective aspects. To be specific, in qualitative comparisons, our fusion results have better contrast ratio and abundant textural details. In quantitative comparisons, TPFusion outperforms existing representative fusion methods. 相似文献