Two commercially available amines, octanediamine (ODM) and m-xylylenediamine (MXDM), were chosen to tough polybenzoxazine resin due to their controllable capability to cause phase separation during the copolymerization with benzoxazine monomers. The toughing behavior and phase separation of the cured resins were investigated using tensile tests and analyses of DMA, SEM, and TGA-GC/MS. The resulting networks showed remarkable toughness without obvious degradation in thermo-mechanical performance. Especially, when ODM/MXDM molar ratio was 1:1, an elongation rate of 10.55% and a breaking strength of 82.67 Mpa, which are 86% and 128% higher than that of the neat benzoxazine resin, respectively, were achieved. These findings open a new way to improve toughness of brittle polybenzoxazine resins.

2017-11-16

National Natural Science Foundation of China （51573167)）

National Natural Science Foundation of China （51573167)）

National Natural Science Foundation of China （51573167)）

National Natural Science Foundation of China （51573167）

National Natural Science Foundation of China （51573167）

Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018,Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018

As a generalization of BCI-algebras with condition (S) and pseudo-BCK algebras with condition (pP), the notion of pseudo-BCI algebras with condition (pP) is introduced. An example of pseudo-BCI algebras with condition (pP) is given, the result that every anti-grouped pseudo-BCI algebras is with condition (pP) is proved. Some properties of pseudo-BCI algebras with condition (pP) are investigated and the branch properties of pseudo-BCI algebras with condition (pP) are discussed.

2010-10-09

Ningbo National Natural Science Foundation of China（Grant No. 2009A610078）

National Natural Science Foundation of China （Grant No. 60775038）

Faculty of Sciences, Ningbo University,Faculty of Sciences, Ningbo University

In recent years, the multi-document summary technology has gotten more and more attention in the field of natural language processing. However, the relationship between the topics and the level information are rarely considered, and sentence scoring is also a very important and difficult task in the multi-document summary process. The results of hLDA (hierarchical Latent Dirichlet Allocation) in the hierarchical topic modeling have been widely validated. Therefore this paper focused on the nodes in the hLDA model, researched the hLDA and semantic based sentence scoring method and presented seven algorithms to provide a strong basis for the multi-document summary.

2013-10-29

National Natural Science Foundation of China （No.61202247）

National Natural Science Foundation of China （No.71231002）

School of Computer Science, Beijing University of Posts and Telecommunications, 100876,School of Computer Science, Beijing University of Posts and Telecommunications, 100876

DCDG-EA: Dynamic Convergence-Diversity Guided Evolutionary Algorithm for Many-Objective Optimization

Maintaining a good balance between convergence and diversity is particularly crucial to the performance of the evolutionary algorithms (EAs). However, traditional multi-objective evolutionary algorithms, which have demonstrated their competitive performance in a variety of practical problems involving two or three objectives, face significant challenges in many-objective optimization problems (MaOPs). This paper proposes a dynamic convergence-diversity guided evolutionary algorithm (DCDG-EA) for MaOPs by employing decomposition technique. The objective space of MaOPs is divided into $K$ subspaces by a set of uniformly distributed reference vectors. Each subspace has its own subpopulation and evolves in parallel with the other subspaces. In DCDG-EA, the balance between convergence and diversity is achieved through convergence-diversity based operator selection (CDOS) strategy and convergence-diversity based individual selection (CDIS) strategy. In CDOS, each operator in a set of operators is assigned a selection probability which is related to its convergence and diversity reward. On the basis of selection probability, an appropriate operator is selected to generate offspring. Furthermore, CDIS greatly overcomes the inefficiency of Pareto dominance. It updates each subpopulation by using two independent distance measures that respectively represent convergence and control diversity. The experimental results on DTLZ benchmark problems with up to 15 objectives show that our algorithm is highly competitive in comparison with the selected four state-of-the-art evolutionary algorithms in terms of convergence and diversity.

2018-04-16

The National Natural Science Foundation of China （No.61672215）

The National Natural Science Foundation of China （U1613209）

College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082,College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082

Correlation filter (CF) based trackers have become quite popular in video tracking because of their impressive performance and high frame rates. A large amount of recent research focuses on the improvement of training model of correlation filter to get a tracker with better discriminative power. However, this only helps the tracker to discriminate the target object from background within a small neighborhood, which is not suitable for fast motion scenes. In this paper, we propose a new detection model to dig out the potential of the correlation filter to deal with the challenge of fast motion. The model performs detection operations on multiple small search areas within a large one. Thus, our tracker can accurately localize the target object in a larger search area. In addition, we also added space constraints to boost the tracking performance of the model. The extensive experimental results demonstrate that the proposed tracker outperforms several state-of-the-art trackers on the challenging benchmark dataset with 51 sequences.

2018-05-02

The National Natural Science Foundation of China （61672215）

The National Natural Science Foundation of China （U1613209）

College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082,College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082

We investigate the problem of cross-tier interference control in full-duplex (FD) Orthogonal Frequency Division Multiple Access (OFDMA) based heterogeneous networks (HetNets) consisting of macrocell and underlaying femtocells. A price mechanism is introduced where the macro base station (MBS) and femtocell base stations (FBSs) all aim to maximize their own utility function considering finite interference constraint. We propose a triple optimization strategy of power control, subcarrier allocation and price regulation which can solve the cross-tier interference optimization problem of femtocell to macrocell. We analyze the superiority of the barrier method for the utility function of the macrocell, and to a certain extent, it has a better convergence. Through the experiment, we can see that the proposed the triple resource allocation algorithm can effectively suppress cross-tier interference and maximize the utility of macrocell and femtocells.

2018-05-03

The National Natural Science Foundation of China （No.61672215）

The National Natural Science Foundation of China （U1613209）

College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082,College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082,College of Computer Science and Electronic Engineering of Hunan University, and Key Laboratory for Embedded and Network Computing of Hunan Province, Changsha 410082

Jiayu Gu,Bingyong Mao,Shumao Cui,Jianxin Zhao,Hao Zhang,Wei Chen

Fructooligosaccharides (FOS) are a well-known class of prebiotic and are considered to selectively stimulate the growth of bifidobacteria in the gut. Previous studies focused on the stimulated growth of Bifidobacterium, but did not further investigate the bifidobacterial composition, i.e. the specific species that was were stimulated. In this study mice were fed with FOS in different doses (0%, 5%, and 25%) for 4 weeks and the composition of fecal microbiota, in particular Bifidobacterium, was analyzed by sequencing the V3-V4 region and the groEL gene on the MiSeq platform, respectively. In the high-dose group (25% FOS) the relative abundance of Actinobacteria was significantly increased, which was mainly contributed by Bifidobacterium. At the genus level the relative abundances of Blautia and Coprococcus were also significantly increased. Through the groEL sequencing 14 species of Bifidobacterium were identified, among which Bifidobacterium pseudolongum (B. pseudolongum) was most abundant. After FOS treatment, B. pseudolongum became almost the sole bifidobacterial species (>95%). We isolated the B. pseudolongum strains and, by high performance liquid chromatography (HPLC), demonstrated their ability to metabolize FOS. Therefore, we concluded that FOS significantly stimulated the growth of B. pseudolongum in mice. Further investigations are needed to reveal the mechanism of selectiveness between FOS and B. pseudolongum, which would aid our understanding of the basic principles of dietary carbohydrates and host health.

2018-03-15

The Youth Program of National Natural Science Foundation of China （No.31601453）

The Key Program of National Natural Science Foundation of China （No.31530056）

The General Program of National Natural Science Foundation of China （No.31471721)）

The Youth Program of National Natural Science Foundation of China （31601453）

The Key Program of National Natural Science Foundation of China （31530056）

The General Program of National Natural Science Foundation of China （31471721）

School of Food Science and Technology, Jiangan University, Wuxi 214122,School of Food Science and Technology, Jiangan University, Wuxi 214122,School of Food Science and Technology, Jiangan University, Wuxi 214122,School of Food Science and Technology, Jiangan University, Wuxi 214122,School of Food Science and Technology, Jiangan University, Wuxi 214122,School of Food Science and Technology, Jiangan University, Wuxi 214122

We study trace operators in weighted variable exponent Sobolev spaces $W^{1,p(x)}(Omega; v_0, v_1)hookrightarrow L^{q(x)}(partial Omega;w)$ for sufficiently regular unbounded domain $Omega subseteq mathbb{R}^{N}$ $(N geq2)$ with noncompact boundary, where $p(x)$ is a Lipschitz continuous function defined on $Omega$ satisfying $1

0$, the trace operators $W^{1,p(x)}(Omega; v_0, v_1)$ $hookrightarrow$ $L^{q(x)}(partial Omega;w)$ is compact under certain conditions on weight functions $v_0$, $v_1$, $w$.

2007-11-05

the National Natural Science Foundation of China（10671084）

Department of Mathematics, Lanzhou University, Lanzhou

Yu Xiangqing ,Bian Hai ,Ge Qin ,Wang Wenxiu ,Yang Zhen ,Zhang Limin ,Liu Zhengmin

The study on hydrogen absorption and desorption properties of titanium under an initial hydrogen pressure of 0.25 MPa at different temperature was fulfilled, the hydrogen absorption rate constant k value is 7.364×10-3s-1 under an initial hydrogen pressure of 0.25 MPa at 773 K. The depth profile of hydrogen in titanium was performed by secondary ion mass spectroscopy, the relative hydrogen content is invariable between about 700nm and 1250nm in titanium. The X-ray diffraction and scanning electron microscope studies on titanium hydride were performed, the TiH phase was found after hydrogen desorption of titanium at 773 K after heating for 5400 seconds.

2008-11-18

the National Natural Science Foundation of China（ 10605011）

School of Nuclear Science and Technology，Lanzhou University,School of Nuclear Science and Technology，Lanzhou University,School of Nuclear Science and Technology，Lanzhou University,School of Nuclear Science and Technology，Lanzhou University,School of Nuclear Science and Technology，Lanzhou University,School of Nuclear Science and Technology，Lanzhou University,School of Nuclear Science and Technology，Lanzhou University

Wen Zhicheng,Fu Mingfu,Chen Liangsen

In the present paper, the Lagrangian finite plasticity theory is discussed based on the theory of materials with elastic range by the assumptions of the existence of a yield functional and a flow rule, to generalize the framework of A.E. Green, P.M. Naghdi and J. Casey (see Naghdi(1990), Brown et al (2003)), so that it can describe better the mechanical behaviors of anisotropic elastic-plastic materials and the strain induced anisotropy. Here the plastic strain, also called intermediate strain, is defined by the plastic stress, and the elastic response functional is assumed to be a functional of plastic strain history. As a result of this definition of intermediate strain, the elastic response functional has a special form, the normal flow rule of generally accepted Il’yushin’s Postulate is the evolution law for the plastic stress. If the plastic stress is also defined to describe the kinematical hardening, it is the kinematical hardening law. The definitions of strain, plastic strain and elastic strain are discussed from a geometric point of view. It is shown that Green-Naghdi elastic strain is the Lagrange elastic strain. The discussion of the consequences of Il’yushin’s Postulate has detailed, the necessary and sufficient condition is obtained. The rate-form of this theory is obtained. The material symmetry and strain induced anisotropy are also discussed in detail. Finally an example of isotropic elastic plastic materials is given. It has been shown that in general this model can satisfy the basic conditions such as Il’yushin postulate and uniqueness and existence of solution of flow rule for any plastic deformation.

2009-01-08

National Natural Science Foundation of China（10272055）

University of Kentucky,School of Architectural Engineering, Nanchang University,School of Architectural Engineering, Nanchang University