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Open access

Guohao Wu, S.K. Zheng and Xiaobing Yan

Abstract

The electronic and optical properties of Mn–S co-doped anatase TiO2 were calculated using the plane-wave-based ultrasoft pseudopotential density functional method within its generalized gradient approximation (GGA). The calculated results show that the band gap of Mn–S co-doped TiO2 is larger than that of the pure TiO2, and two impurity bands appear in the forbidden band, one of which above the valence band plays a vital role for the improvement of the visible light catalytic activity. The Mn–S co-doped anatase TiO2 could be a potential candidate for a photo catalyst because of its enhanced absorption ability of visible light.

Open access

Wu Yan and Fu Jing-Li

Abstract

This paper deals with the Noether’s theory for variable mass system on time scales. The calculus on time scales unifies and extends variable mass system continuous model and discrete model into a single theory. Firstly, Hamilton’s principle of the variable mass system on time scales is given. Secondly, based on the quasi-invariance of the Hamilton’s action under a group of infinitesimal transformations, Noether’s theorem and its inverse theorem of the variable mass system on time scales are presented. Finally, two examples are given to illustrate the applications of the results.

Open access

Hui Yang, Yan Zhao, Min Li and Falin Wu

Abstract

To reduce the influence of the static unbalance on an infrared missile guidance system, a new static unbalance measure system for the gimbals axes has been developed. Considering the coupling effects caused by a mass eccentricity, the static balance condition and measure sequence for each gimbal axis are obtained. A novel static unbalance test approach is proposed after analyzing the dynamic model of the measured gimbal axis. This approach is to drive the measured gimbal axis to do sinusoidal reciprocating motion in a small angle and collect its drive currents in real time. Then the static unbalance of the measured gimbal axis can be obtained by the current multi-cycle integration. Also a measuring system using the proposed approach has been developed. A balanced simulator is used to verify the proposed approach by the load and repeatability tests. The results show the proposed approach enhances the efficiency of the static unbalance measurement, and the developed measuring system is able to achieve a high precision with a greater stability.

Open access

Shuiping Li, Qisheng Wu, Chong Cui, Guosen Lu, Changsen Zhang and Zhiye Yan

Abstract

TiO2/Al-MCM-41 mesoporous materials were prepared via sol-gel method by loading titania onto Al-MCM-41 mesoporous molecular sieve by hydrothermal treatment from coal-series kaolin as raw material. The TiO2/Al-MCM-41 mesoporous materials were characterized by XRD, FT-IR, HRTEM, N2 adsorption-desorption and the photocatalytic degradation of methyl orange solution under visible light irradiation. The results showed that the TiO2/Al-MCM-41 mesoporous materials possessed a high surface area of 369.9–751.3 m2/g and a homogeneous pore diameters of 2.3–2.8 nm. The titania crystalline phase was anatase, and the particles size of TiO2 increased with TiO2 content. The Al-MCM-41 mesoporous materials exhibited excellent photodegradation activity under visible-light irradiation for methyl orange.

Open access

Haiyong Wu and Senlin Yan

Abstract

This paper presents a new set of bivariate discrete orthogonal moments which are based on bivariate Hahn polynomials with non-separable basis. The polynomials are scaled to ensure numerical stability. Their computational aspects are discussed in detail. The principle of parameter selection is established by analyzing several plots of polynomials with different kinds of parameters. Appropriate parameters of binary images and a grayscale image are obtained through experimental results. The performance of the proposed moments in describing images is investigated through several image reconstruction experiments, including noisy and noise-free conditions. Comparisons with existing discrete orthogonal moments are also presented. The experimental results show that the proposed moments outperform slightly separable Hahn moments for higher orders.

Open access

Zhong Wu and Ruixia Yan

Abstract

To tackle a multi-attribute decision making problem, rough set and casebased reasoning are often combined. However, the reduction in a rough set is always complex. In this paper we provide a new relative importance measure about the unitary attributes values by ranking the relative importance of the attributes in the rough set theory. A new rough set model based on ranking the relative importance of the attributes is built and its properties are studied. Then unitary attributes values are utilized to compute the similarity of rules in case-based reasoning, for there might be incompletely match or miss values. A new multiattribute decision making based on case-based reasoning and a rough set based on the ranking relative importance of the attributes is constructed, which obtains rules, avoiding reduction and rule extraction.

Open access

Tingzeng Wu, Weigen Yan and Heping Zhang

Abstract

Gutman and Wagner proposed the concept of the matching energy which is defined as the sum of the absolute values of the zeros of the matching polynomial of a graph. And they pointed out that the chemical applications of matching energy go back to the 1970s. Let T be a tree with n vertices. In this paper, we characterize the trees whose complements have the maximal, second-maximal and minimal matching energy. Furthermore, we determine the trees with edge-independence number p whose complements have the minimum matching energy for p = 1, 2, . . . , [n/2]. When we restrict our consideration to all trees with a perfect matching, we determine the trees whose complements have the second-maximal matching energy.

Open access

Chang-Qun Wu and Yan Hao

Abstract

In this paper, the problem of modifying Halpern iteration for approximating a common fixed point of a family of asymptotically quasi- ∅-nonexpansive mappings is considered. Strong convergence theorems are established in a uniformly smooth and strictly convex Banach space which also enjoys the Kadec-Klee property. The results presented in this paper mainly improve the corresponding results announced in [Y.J. Cho, X. Qin, S.M. Kang, Strong convergence of the modified Halpern- type iterative algorithms in Banach spaces, An. Stiint. Univ. Ovidius Constanta Ser. Mat. 17 (2009) 51-68].

Open access

Qiu Jue Wu, Qin Yu Wang, Tian Wang and Yan Min Zhou

Abstract

The effects of natural clinoptilolite (NCLI) and modified clinoptilolite (MCLI) were evaluated in broilers challenged with lipopolysaccharide (LPS) in a 21-d feeding trial. A total of 288 one-day-old chickens were allocated into three treatment groups: control, NCLI (2%) and MCLI (2%). Half of the birds from each treatment group were challenged with either 0.9% NaCl solution or LPS (250 μg/kg body weight, orally administered) at 16, 18 and 21 d of age. Before the LPS challenge, no dietary effect on bird growth performance was found (P>0.05). When LPS was orally administered, no significant changes in growth performance of broilers was found (P>0.05). However, small intestinal morphology and development, malondialdehyde (MDA) content of the jejunual and ileal mucosa, and superoxide dismutase (SOD) activity of the ileal mucosa were significantly affected (P<0.05). Supplementation with NCLI and MCLI significantly decreased the MDA contents of the jejunual and ileal mucosa and improved the SOD activity of the ileal mucosa and the development of the small intestine compared with the control group (P<0.05). The results indicated that NCLI and MCLI additions in feed had protective effects on the gut health of broilers against LPS challenge.

Open access

Wen-jie Zhang, Zhao-xia Li, Deng-hai Mi, Jing Li, Jian-jun Yang, Wei-wu Mao, Yan-xuan Gong and Yan Qu

Abstract

Objective To investigate the occurrence of basal core promoter (BCP) and pre-C mutations in patients with hepatitis B virus (HBV) infection in Gansu Province, China, and to analyze the correlation of HBV mutation and HBV genotype with primary hepatocellular carcinoma (HCC).

Methods PCR-RFLP was applied to detect HBV subgenotypes, and the presence of the pre-C and BCP mutations in 62 patients with HCC, 70 patients with hepatitis B induced liver cirrhosis (LC) and 90 patients with chronic hepatitis B (CHB).

Results In HCC patients, genotype C was the major genotype (70.97%). The pre-C mutation was found in 59.68%, 31.43% and 16.67% patients with HCC, LC and CHB, respectively. The frequency of BCP mutations was significantly different between patients with HCC, LC and CHB (74.19%, 51.43% and 37.78%, respectively; X2=30.727, 19.540, respectively, P < 0.01). Patients in HCC group had a higher incidence of pre-C as well as BCP mutations compared to the other groups. The prevalence of pre-C and BCP mutations was significantly higher in patients with genotype C1 (44.32% and 69.32%, respectively) compared to patients with other subgenotypes (P < 0.05).

Conclusions The incidence of pre-C and BCP mutations increases with disease progression. Pre-C and BCP mutations frequently occur in patients with genotype C1. HBV genotype C, pre-C mutations and BCP mutations are closely related to the occurrence of HCC.