ANALYTIC METHOD FOR INVERSING THE OPEN BOUNDARY CONDITIONS IN A SEMI-CLOSED SEA AREA——CASE I FOR INVERSING THE TIDAL LEVELS AT OPEN BOUNDARY

In this paper, a computational case was employed to describe the computational procedure for inversing the tidal level open boundary conditions using an analytic method. The area for finding the solution is a circular area with a circular arc with the opening angle 60~-being the open boundary and the other circular arc being the solid wall boundary. Proceeding from the reestablished elliptic partial differential equation satisfied by the tidal level function, the extended spectrum method was used to derive the general solution of the equation for the sea of constant depth, and the impermeable solid wall condition (the second class boundary condition) and the adequately specified open boundary conditions were then applied to determine the undetermined coefficients of the general solution, thus obtaining the tidal level distribution function. In this way, both the first and second class boundary values at the solid wall boundary were obtained. With the above boundary values as the boundary conditions, the tidal level values at the open boundary were then inversed by means of the general solution of tidal wave equation. The validity of inversion method could be verified by comparing the inversed tidal level distributions with the originally specified open boundary values.     

Revealing the Origins of Mechanically Induced Fluorescence Changes in Organic Molecular Crystals

Mechanofluorochromic molecular materials display a change in fluorescence color through mechanical stress. Complex structure–property relationships in both the crystalline and amorphous phases of these materials govern both the presence and strength of this behavior, which is usually deemed the result of a mechanically induced phase transition. However, the precise nature of the emitting species in each phase is often a matter of speculation, resulting from experimental data that are difficult to interpret, and a lack of an acceptable theoretical model capable of capturing complex environmental effects. With a combined strategy using sophisticated experimental techniques and a new theoretical approach, here the varied mechanofluorochromic behavior of a series of difluoroboron diketonates is shown to be driven by the formation of low‐energy exciton traps in the amorphous phase, with a limited number of traps giving rise to the full change in fluorescence color. The results highlight intrinsic structural links between crystalline and amorphous phases, and how these may be exploited for further development of powerful mechanofluorochromic assemblies, in line with modern crystal engineering approaches.     

A related key impossible differential attack against 22 rounds of the lightweight block cipher LBlock

LBlock is a new lightweight block cipher proposed by Wu and Zhang (2011) [12] at ACNS 2011. It is based on a modified 32-round Feistel structure. It uses keys of length 80 bits and message blocks of length 64 bits.In this letter, we examine the security arguments given in the original article and we show that we can improve the impossible differential attack given in the original article on 20 rounds by constructing a 22-round related key impossible differential attack that relies on intrinsic weaknesses of the key schedule. This attack has a complexity of 2⁷⁰ cipher operations using 2⁴⁷ plaintexts. This result was already published in Minier and Naya-Plasencia (2011) [9].     

Developing radical innovation capabilities: Exploring the effects of training employees for creativity and innovation

The resilience of organizations is increasingly dependent on their ability to develop radical innovation capabilities. While the literature documents numerous cases of organizations that already have radical innovation capabilities, the question of organizational devices that can be used to stimulate the emergence of such capabilities remains poorly addressed. Specifically, training for innovation and creativity has been proposed as a means to foster innovation capabilities; however, there has been little empirical evidence concerning the long‐term impacts of such training. To fill this gap, this article aims to document and evaluate the efforts of the research institute of a major Canadian energy company to provide training for innovation and creativity to initiate a radical innovation capability. We rely on a longitudinal study over the span of 18 months, where we observed 128 h of training and conducted 70 semi‐structured interviews with a sample of 40 researchers. We found that training for creativity and innovation has the potential to develop individual creative skills for exploration, to catalyze and federate collective action through common methods and a shared sense of what innovation entails, and to help create a common language and vocabulary between the different groups or divisions of an organization to talk about exploration.     

Robust adaptive observers for nonlinear systems with boundeddisturbances

Since existing adaptive observers for nonlinear systems may generate unbounded parameter estimates in the presence of bounded disturbances, robust adaptive observers are presented which prevent parameter estimate drift. In addition the input-to-state stability of the error dynamics with respect to disturbances and parameter time-derivatives is guaranteed by generalizing a persistency of excitation result. Asymptotic convergence of state estimation errors is still achieved for systems in adaptive observer form when disturbances are not present, by a suitable extension of Barbalat's lemma     

海洋和除冰盐条件下混凝土结构的Cl-扩散行为及耐久性设计

研究了海洋和除冰盐条件下暴露7～18a的混凝土结构Cl-浓度分布规律,探讨了混凝土结构的耐久性设计.结果表明,在严酷环境条件下混凝土结构的Cl-扩散行为符合修正的Fick第二扩散定律,混凝土的最大水胶比和最小保护层厚度是保证结构工程使用寿命的重要耐久性设计参数.     

映射内插高精度频率估计

如何精确估计噪声中的正弦信号的频率是雷达、声纳、通信和生物医学工程等许多领域中的—个重要问题.对于高斯白噪声中的单个或能够很好分辨的P个正弦信号,其频率的极大似然估计就是周期图频率估计(PFE),也就是周期图功率谱最大的P个谱峰所对应的频率[1]. 在实际应用中,由于使用FFT等数字技术,对大量位于离散的谱线之间的频率均无法得到精确的频率估计.通常减小估计误差的方法有两种:一种是增加谱线的条数(M),但使计算量显著增加;另一种是利用抛物线内插法(PIFE),对谱峰的位置加以修正.这些方法减小误差的效果仍不明显,其频率估计的均方根误差(RMSE)如图1所示.     

Excited States Computation of Models of Phenylalanine Protein Chains: TD-DFT and Composite CC2/TD-DFT Protocols

The present benchmark calculations testify to the validity of time-dependent density functional theory (TD-DFT) when exploring the low-lying excited states potential energy surfaces of models of phenylalanine protein chains. Among three functionals suitable for systems exhibiting charge-transfer excited states, LC-ωPBE, CAM-B3LYP, and ωB97X-D, which were tested on a reference peptide system, we selected the ωB97X-D functional, which gave the best results compared to the approximate coupled-cluster singles and doubles (CC2) method. A quantitative agreement for both the geometrical parameters and the vibrational frequencies was obtained for the lowest singlet excited state (a ππ* state) of the series of capped peptides. In contrast, only a qualitative agreement was met for the corresponding adiabatic zero-point vibrational energy (ZPVE)-corrected excitation energies. Two composite protocols combining CC2 and DFT/TD-DFT methods were then developed to improve these calculations. Both protocols substantially reduced the error compared to CC2 and experiment, and the best of both even led to results of CC2 quality at a lower cost, thus providing a reliable alternative to this method for very large systems.     

<Emphasis Type="Italic">Trans</Emphasis> Fatty Acids Suppress TNF-α-Induced Inflammatory Gene Expression in Endothelial (HUVEC) and Hepatocellular Carcinoma (HepG2) Cells

Trans fatty acids (TFA) intake has been linked to cardiovascular diseases and liver diseases; yet the effect of TFA on inflammation remains controversial. Accordingly, the objective of this paper was to determine the in vitro effects of TFA on inflammatory gene expression. Human umbilical vein endothelial cells (HUVEC) and human hepatocellular carcinoma (HepG2) cells were treated for 24 h with either trans-vaccenic acid (tVA), trans-palmitoleic acid (tPA) or elaidic acid (EA) at concentrations of 5–150 µM, or with a mixture of tVA and tPA (150/50 µM). All TFA were highly incorporated into cell membranes, as determined by gas chromatography, representing 15–20% of total fatty acids in HUVEC and 3–8% in HepG2 cells. Incorporation of EA, a common industrial TFA, increased the ratio of the stearoyl-CoA desaturase (SCD-1), a key enzyme involved in fatty acid metabolism. Ruminant TFA, including tVA, tPA and the mixture of tVA and tPA, significantly reduced the TNF-α-induced gene expression of TNF, VCAM-1 and SOD2 in HUVEC, as well as TNF and IL-8 in HepG2 cells. EA also decreased inflammatory gene expression in HUVEC, but not in HepG2 cells. The inhibition of peroxisome proliferator-activated receptor (PPAR)-γ did not influence the effects of TFA on gene expression. Overall, physiological and supraphysiological concentrations of TFA, especially tVA and tPA, prevented inflammatory gene expression in vitro. This effect is independent of PPAR-γ activation and may be due to an alteration of fatty acid metabolism in cell membranes caused by the high incorporation of TFA.