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761.
Ju.T. Lisica 《Topology and its Applications》2010,157(17):2715-2735
Three data are interesting here: domains of integration, integrands and integration itself. There is a lack of symmetry between polyhedral chains as domains of integration and differential forms as integrands. The non-symmetric situation disappears after considering the topological spaces of the de Rham differential forms and forms with compact supports and their strong duals, i.e., currents with compact supports and currents, respectively. This idea goes back to Schwartz distributions and Schwartz distributions with compact supports, in other terminology, generalized functions and generalized functions with compact supports.Some problems are raised, e.g., whether every quasi-complete barreled nuclear space E, whose strongly dual E′ is nuclear, is strongly hereditary reflexive. This concerns the above mentioned de Rham spaces. Problems on R- and Q-homotopy, proper R- and Q-homotopy and proper R- and Q-homotopy at infinity are also considered as well as the coalgebra structure on currents and currents with compact supports.The classical theorem concerning derivation of additive functions with respect to volumes in points is generalized to a theorem on derivation of continuous m-forms with compact supports ωm of an oriented n-dimensional C1-manifold Mn with respect to its m-dimensional oriented submanifolds Vm in compact regular oriented submanifolds Lk of Mn, 0?k<m?n. 相似文献
762.
Bart De Bruyn 《Journal of Combinatorial Theory, Series A》2010,117(5):528-544
Let n∈N?{0,1} and let K and K′ be fields such that K′ is a quadratic Galois extension of K. Let Q−(2n+1,K) be a nonsingular quadric of Witt index n in PG(2n+1,K) whose associated quadratic form defines a nonsingular quadric Q+(2n+1,K′) of Witt index n+1 in PG(2n+1,K′). For even n, we define a class of SDPS-sets of the dual polar space DQ−(2n+1,K) associated to Q−(2n+1,K), and call its members geometric SDPS-sets. We show that geometric SDPS-sets of DQ−(2n+1,K) are unique up to isomorphism and that they all arise from the spin embedding of DQ−(2n+1,K). We will use geometric SDPS-sets to describe the structure of the natural embedding of DQ−(2n+1,K) into one of the half-spin geometries for Q+(2n+1,K′). 相似文献
763.
J. Lorenzo-Trueba 《Journal of Mathematical Analysis and Applications》2010,366(2):538-549
A model associated with the formation of sedimentary ocean deltas is presented. This model is a generalized one-dimensional Stefan problem bounded by two moving boundaries, the shoreline and the alluvial-bedrock transition. The sediment transport is a non-linear diffusive process; the diffusivity modeled as a power law of the fluvial slope. Dimensional analysis shows that the first order behavior of the moving boundaries is determined by the dimensionless parameter 0?Rab?1—the ratio of the fluvial slope to bedrock slope at the alluvial-bedrock transition. A similarity form of the governing equations is derived and a solution that tracks the boundaries obtained via the use of a numerical ODE solver; in the cases where the exponent θ in the diffusivity model is zero (linear diffusion) or infinite, closed from solutions are found. For the full range of the diffusivity exponents, 0?θ→∞, the similarity solution shows that when Rab<0.4 there is no distinction in the predicted speeds of the moving boundaries. Further, within the range of physically meaningful values of the diffusivity exponent, i.e., 0?θ∼2, reasonable agreement in predictions extents up to Rab∼0.7. In addition to the similarity solution a fixed grid enthalpy like solution is also proposed; predictions obtained with this solution closely match those obtained with the similarity solution. 相似文献
764.
Justin McInroy 《Discrete Mathematics》2010,310(8):1381-1388
Suppose Δ is a dual polar space of rank n and H is a hyperplane of Δ. Cardinali, De Bruyn and Pasini have already shown that if n≥4 and the line size is greater than or equal to 4 then the hyperplane complement Δ−H is simply connected. This paper is a follow-up, where we investigate the remaining cases. We prove that the hyperplane complements are simply connected in all cases except for three specific types of hyperplane occurring in the smallest case, when the rank and the line size are both 3. 相似文献
765.
DENG GuoHua & LIANG HuaSchool of Finance Statistics Jiangxi University of Finance Economics Nanchang China 《中国科学 数学(英文版)》2010,(5)
To improve the prediction accuracy of semiparametric additive partial linear models(APLM) and the coverage probability of confidence intervals of the parameters of interest,we explore a focused information criterion for model selection among ALPM after we estimate the nonparametric functions by the polynomial spline smoothing,and introduce a general model average estimator.The major advantage of the proposed procedures is that iterative backfitting implementation is avoided,which thus results in gains in co... 相似文献
766.
In this paper, we consider revenue management for a service supply chain with one supplier and one retailer. The supplier has a limited capacity of a perishable product and both the supplier and the retailer face customers. Each customer may choose to buy a product from either the supplier or the retailer by considering prices and the cost associated with switching. For the centralized model, the supplier determines the selling prices for both herself and the retailer, and the retailer simply collects a commission fee for each product sold. We derive monotone properties for the revenue functions and pricing strategies. Further, we show that the commission fee increases the retailer’s price while decreasing the supplier’s and leads to efficiency loss of the chain. For the decentralized decision-making model, the supplier and the retailer compete in price over time. Two models are considered. In the first, the retailer buys products from the supplier before the selling season and in the second the retailer shares products with the supplier in retailing. For both models, we discuss the existence of the equilibrium and characterize the optimal decisions. Numerical results are presented to illustrate properties of the models and to compare the supply chain performance between the centralized and the decentralized models. 相似文献
767.
Baolu Shi Qing Cao Dingjiang Xie Weikang Peng Ningfei Wang 《Proceedings of the Combustion Institute》2019,37(4):4329-4336
To utilize sustainable biofuel, the current study proposes a novel combustion technique that directly burns liquid ethanol without a spray system. Two swirling air flows are induced by tangentially injected the gas from two concentric tubes at different stages. The liquid ethanol is fed by a liquid tank at the center. At the beginning methane flame assists in preheating the system to vaporize liquid ethanol and ignite the vapor. Thereafter methane is switched off, and liquid ethanol can be continuously vaporized through self-burning released heat. The heat and mass transfer processes are examined to illustrate such self-sustained burning–heating–evaporating system. The ethanol flow rate is gradually increased to provide different heat output. The flame structures, temperature distributions and pollutant emissions are carefully examined. The results show that the ethanol can be steadily burned to provide heat output between 0.7 and 2.5?kW. Generally a blue flame is obtained, and the NOx and CO concentrations are ultralow. By increasing ethanol flow rate to exceed 8?mL/min, an unsteady, sooting flame is observed owing to incomplete evaporation and poor mixing. A parametric study is conducted to evaluate the influences of liquid tank position, flow rate and tip structure on the combustion characteristics. Additionally, an optimal operation condition is proposed. The current study provides a promising method to burn low-boiling liquid fuel in a clean, efficient and compact way. 相似文献
768.
《中国化学快报》2019,30(12):2039-2042
Responsive polymers have been playing an increasingly important role in a wide variety of applications,such as biomedical materials and biosensors.Herein,we reported a dual-responsive polycarbonate(poly(MN-co-MSS)) based on the macrocyclic Sulfur/Nitrogen-substituted carbonate monomer(MSS/MN) via an enzyme-catalyzed ring-opening copolymerization and Lipase CA Novozym-435 as catalyst,with the disulfide and tertiary amine groups situated on the backbone.The structure of the random copolymers was confirmed by NMR and FTIR.In addition,size exclusion chromatography(SEC) results indicated that the copolymer had a symmetric peak and a relatively narrow polydispersity.Also,the random copolymers can self-assemble into micelle-like aggregates in water due to the hydrophilicity endowed by the amino groups,and the aggregates exhibited rich pH and GSH responsive behavior,which was verified by zeta masters instrument and dynamic light scattering(DLS).Moreover,transmission electron microscopy(TEM) demonstrated the morphology of the micellar aggregates and the variation subjected to the lower pH and GSH,and the responsive mechanism was elaborated.Therefore,these results highlighted a facile synthesis of the environment-responsive polymers and provided a novel GSH/pH responsive material platform for further application. 相似文献
769.
XiaoGuang Ma Liang Wang Lei Li LiRan Bian WenFang Yang QingTao Meng 《高分子科学杂志,A辑:纯化学与应用化学》2019,56(6):588-596
In order to solve the problem of narrow color change range for common thermochromic material, the novel thermochromic and energy-storage microcapsules (TCEMs) was designed and synthesized by in-situ polymerization. The TCEMs contained optimizational thermochromic components and phase change materials, and exhibited the dual functional performances of thermochromic and energy-storage. Then, the TCEMs were applied to polyester/cotton blend fabric with waterborne polyurethane by coating process. The growing process, exterior morphology, color change effect, temperature-regulable behavior and thermal activity of the TCEMs and the treated fabrics were investigated. The results demonstrated that both TCEMs and modified fabrics had good energy-storage effect and remarkable thermochromic property. Especially, while surrounding temperature changed from 15?°C to 45?°C, the colors of TCEMs and treated fabrics could change from cool-tone (blue) to warm-tone (red), which significantly improved the color change range of the thermochromic material and made the color vary between different tones instead of changing in the region of similar color. The TCEMs exhibited great potentiality in the applying fields of decoration, anti-counterfeiting, architecture and intelligent textile, etc. 相似文献
770.
为了对雾霾天气下的图像进行去雾处理,多幅图像去雾算法是常用的方法之一。多幅图像去雾算法也有多种形式,部分算法面临硬件实现困难、获取途径受限或者可实施性弱等问题,而且多幅图像比对处理时常常涉及图像配准,造成算法的实时性差、计算复杂度高等问题。针对以上问题,提出的算法为多幅图像去雾提供了新的思路,基于双目传感器硬件架构能够同时捕获近红外和可见光图像,将近红外传感器图像作为新的数据源,近红外传感器能够在一定程度上穿透雾霾,在雾天捕获可见光传感器无法捕获的图像细节,而且硬件实现简单。可见光图像的颜色信息较丰富,近红外传感器图像对近处场景细节的描述能力较好,捕获的图像稍加校正就能实现完全配准,将近红外图像与可见光图像进行融合,在去雾的同时,可以将近红外传感器图像中的原始细节提取融合到彩色可见光传感器图像中,得到边缘、轮廓等细节信息更加丰富的去雾图像。基于上述思路,借助近红外传感器对边缘细节的描述能力和可见光传感器对颜色信息的反映能力,提出了一种基于近红外与可见光双通道传感器图像融合的去雾算法。首先,将彩色可见光图像转换到HIS彩色空间,分别得到亮度通道图像、色调通道图像和饱和度通道图像。先将其亮度通道图与近红外图像进行融合去雾处理。采用非下采样Shearlet变换(NSST)进行分解,对得到的高频系数进行双指数边缘平滑滤波器保边滤波处理,对低频系数进行反锐化掩蔽处理,通过融合规则和反向变换得到新的亮度通道图像。然后,在对可见光图像的色彩处理中,建立饱和度图的退化模型,采用暗原色原理对参数进行估计,得到估计的饱和度图。最后,将新的亮度通道图像,估计的饱和度图像和原色调图像反映射到RGB空间得到去雾图像。为了验证新算法的有效性,特选取四组雾天拍摄的真实近红外图像与可见光图像进行融合去雾处理,将融合结果与其他两种去雾方法对于彩色可见光图像的去雾效果进行比较。实验结果表明,该算法在提高图像的边缘对比度和视觉清晰度上有较好的效果。并提出将近红外传感器图像作为新的数据源,采用双通道图像融合方法进行去雾处理,为图像去雾提供的新的技术思路是可行的。该算法的优势在于:首先提出将图像融合方法与去雾算法相结合,得到了新的去雾算法的思路。将彩色可见光图像转换到HSI色彩空间,将其亮度通道图与近红外图像采用非下采样Shearlet变换方法进行融合处理,在去雾的同时,可以将近红外传感器图像中的原始细节提取融合到彩色可见光传感器图像中,使得去雾图像中的边缘、轮廓等细节信息更加丰富。其次,提出了在图像去雾算法中采用新的数据源--近红外传感器图像,从图像处理的角度,近红外传感器能够在一定程度上穿透雾霾,对于近处场景细节的描述能力较好,而且硬件实现简单,捕获的图像稍加校正就能实现完全配准,为后续的融合去雾算法带来了便利,为图像去雾提供了新的技术途径和路线。再次,采用的是多幅图像去雾算法,该算法基于双目传感器获取图像,可见光图像的颜色信息较丰富,近红外图像对于近处场景细节的描述能力较好,相对于单幅图像去雾算法,有更好的效果。最后,将可见光传感器图像映射到其他色彩空间,对于每个通道的图像根据其特征有针对性地进行处理。可见光图像的亮度通道图和近红外图像的处理采用了图像融合和增强处理,对于可见光图像饱和度通道的处理采用了图像复原算法,可以从整体上提升去雾效果,对细节特征有了进一步增强。该算法为图像去雾提供了新的技术途径和路线。 相似文献