检索结果-内蒙古大学图书馆

Effect of zinc additions on the microstructure mechanical properties and creep behavior of as-cast Mg-3Sm-0.4Zr (wt.%) alloy

引用

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 2010年第18-19期527卷 4605-4612页

作者： Zheng, Jiang Wang, Qudong Jin, Zhengli Peng, Tao Shanghai Jiao Tong Univ Natl Engn Res Ctr Light Alloys Net Forming Sch Mat Sci & Engn Shanghai 200240 Peoples R China Shanghai Jiao Tong Univ State Key Lab Met Matrix Composites Sch Mat Sci & Engn Shanghai 200240 Peoples R China

The influence of zinc (Zn) additions (0, 0.5, 1 wt.%) on the microstructure, mechanical properties of as-cast Mg-3Sm-0.4Zr (wt.%) alloy has been investigated in the present study. Compared with the Zn-free alloy, addition of 0.5 wt.% Zn results in the formation of great amounts of fine precipitates in the regions close to grain boundaries, which effectively retard dislocation motion and dramatically enhance the tensile strength at 200 and creep resistance. For the alloy containing higher zinc content (=1 wt.%), the excellent creep resistance is mainly attributed to the suppression of non-basal dislocation slip due to the presence of planar defects. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Magnesium alloy Tensile properties Creep Microstructure

来源：评论

学校读者我要写书评

暂无评论

Cross immunity of DNA vaccine pVAX1-cSZ2-IL-2 to Eimeria tenella, E. necatrix and E. maxima

引用

EXPERIMENTAL PARASITOLOGY 2010年第3期124卷 330-333页

作者： Shah, Mohammed Ali A. Xu, Lixin Yan, Ruofeng Song, Xiaokai Li, Xiangrui Nanjing Agr Univ Coll Vet Med Nanjing 210095 Jiangsu Peoples R China

The study describes cross protection experiments with chimeric DNA vaccine pVAX1-cSZ2-IL-2 to determine its efficacy against four important Eimeria species. Seven-day-old chickens were randomly divided into nine groups;group I negative control, groups 2, 3, 4, 5 positive controls;and groups 6, 7, 8 and 9 experimental groups. On days 7 and 14, groups 1-5 were injected with TE buffer, and groups 6-9 with the vaccine. At 21 days of age, all chickens were inoculated with 5 x 10(4) sporulated oocysts except for the negative control. Groups 2 and 6 were inoculated with Eimeria tenella, groups 3 and 7 with Eimeria necatrix, groups 4 and 8 with Eimeria acervulina and groups 5 and 9 with Eimeria maxima. Seven days later, all chickens were weighed and slaughtered to obtain intestinal samples. Efficacy of immunization was evaluated on the basis of oocyst decrease ratio, lesion score, body-weight gain and anti-coccidial index. The results indicated that the recombinant plasmid can induce host immune responses by alleviating intestinal lesions, body weight loss and oocyst ratio and imparting good protection against E. tenella and E. acervulina, medium protection against E. necatrix but little effect against E. maxima. It is concluded that the conserved antigen can provide cross protection and should be explored further. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Eimeria cSZ-2 DNA vaccine Cross protection

来源：评论

学校读者我要写书评

暂无评论

development of organovermiculite-based adsorbent for removing anionic dye from aqueous solution

引用

JOURNAL OF HAZARDOUS MATERIALS 2010年第1-3期180卷 499-507页

作者： Yu, Xubiao Wei, Chaohai Ke, Lin Hu, Yun Xie, Xiaoqi Wu, Haizhen S China Univ Technol Coll Environm Sci & Engn Guangzhou Higher Educ Mega Ctr Guangzhou 510006 Guangdong Peoples R China S China Univ Technol Coll Biosci & Bioengn Guangzhou 510006 Guangdong Peoples R China Liaoning Univ Technol Coll Chem & Environm Engn Jinzhou 121001 Liaoning Peoples R China

This paper reports on the development of organovermiculite-based adsorbent for removing Congo Red (CR), a model anionic dye, from aqueous solution. The organovermiculite was prepared using hexadecyl trimethylammonium bromide (HDTMAB) with variations in cation exchange capacity (CEC) and was then characterized by X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results from the adsorption experiments showed that with the organic modification of 50, 100, and 200% CEC, the adsorption capacity of vermiculite towards CR was greatly improved from 2.6 to 74.07, 175.44 and 192.31 mg/g, respectively, at 298 K. The adsorption isotherm experiment was conducted at different temperatures (298, 308 and 318 K), and it was found that the uptake of CR increased with increasing temperature. Langmuir and Freundlich isotherm models were applied and the Langmuir model was found to fit the equilibrium data better. The adsorption kinetics was found to follow the pseudo-second-order model. In addition, various thermodynamic parameters such as changes in enthalpy. entropy, and the Gibbs free energy were calculated, showing adsorption to be an endothermic yet spontaneous process. The results indicated that the organovermiculite may be an effective adsorbent for the removal of anionic dyes from wastewater. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Vermiculite Organoclay Adsorption Congo Red

来源：评论

学校读者我要写书评

暂无评论

Bayesian discriminant analysis for prediction of coal and gas outbursts and application

引用

Mining Science and technology 2010年第4期20卷 520-523,541页

作者： WANG Chao WANG Enyuan XU Jiankun LIU Xiaofei LING Li School of Safety Engineering China University of Mining ＆ Technology Xuzhou 221116 China

Based on the principle of Bayesian discriminant analysis, we established a model of Bayesian discriminant analysis for predicting coal and gas outbursts. We selected five major indices which affect outbursts, i.e., initial speed of methane diffusion, a consistent coal coefficient, gas pressure, destructive style of coal and mining depth, as discriminating factors of the model. In our model, we divided the type of coal and gas outbursts into four grades regarded as four normal populations. We then obtained the corresponding discriminant functions through training a set of data from engineering examples as learning samples and evaluated their criteria by a back substitution method to verify the optimal properties of the model. Finally, we applied the model to the prediction of coal and gas outbursts in the Yunnan Enhong Mine. Our results coincided completely with the actual situation. These results show that a model of Bayesian discriminant analysis has excellent recognition performance, high prediction accuracy and a low error rate and is an effective method to predict coal and gas outbursts.

关键词： Bayesian discriminant analysis coal and gas outbursts learning samples prediction

来源：评论

学校读者我要写书评

暂无评论

Risk assessment of human neural tube defects using a Bayesian belief network

引用

STOCHASTIC ENVIRONMENTAL research AND RISK ASSESSMENT 2010年第1期24卷 93-100页

作者： Liao, Yilan Wang, Jinfeng Guo, Yaoqin Zheng, Xiaoying Chinese Acad Sci Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China Peking Univ Inst Populat Res Beijing 100871 Peoples R China

Neural tube defects (NTDs) constitute the most common type of birth defects. How much risk of NTDs could an area take? The answer to this question will help people understand the geographical distribution of NTDs and explore its environmental causes. Most existing methods usually take the spatial correlation of cases into account and rarely consider the effect of environmental factors. However, especially in rural areas, the NTDs cases have a little effect on each other across space, whereas the role of environmental factors is significant. To demonstrate these points, Heshun, a county with the highest rate of NTDs in china, was selected as the region of interest in the study. Bayesian belief network was used to quantify the probability of NTDs occurred at villages with no births. The study indicated that the proposed method was easy to apply and high accuracy was achieved at a 95% confidence level.

关键词： Neural tube birth defects Bayesian belief network Data discretization Case-effect relationship

来源：评论

学校读者我要写书评

暂无评论

Removal of cadmium(II) from aqueous solution by corn stalk graft copolymers

引用

BIORESOURCE techNOLOGY 2010年第15期101卷 5820-5826页

作者： Zheng, Liuchun Dang, Zhi Zhu, Chaofei Yi, Xiaoyun Zhang, Hui Liu, Congqiang S China Univ Technol Coll Environm Sci & Engn Guangzhou Higher Educ Mega Ctr Guangzhou 510006 Guangdong Peoples R China Minist Educ Key Lab Pollut Control & Ecosyst Restorat Ind Clu Guangzhou 510006 Guangdong Peoples R China S China Univ Technol Coll Environm Sci & Engn State Key Lab Pulp & Paper Engn Guangzhou 510640 Guangdong Peoples R China Guilin Univ Technol Sch Environm Sci & Engn Guilin 541004 Peoples R China Chinese Acad Sci Inst Geochem State Key Lab Environm Geochem Guiyang 550002 Peoples R China

Corn stalk was modified using graft copolymerization to produce absorbent (AGCS), which was characterized by elemental analysis, fourier transform infrared, X-ray diffraction, solid-state CP/MAS C-13 NMR spectra, thermogravimetric analysis and differential scanning calorimeter. AGCS, having cyano group (-CN) after grafted successfully, exhibits more high adsorption potential for Cd(II) than unmodified forms. The efficiency of AGCS for removal of cadmium ions was evaluated. Factors affecting Cd(II) adsorption such as pH value and adsorbent dosage were investigated. More than 90% removal was achieved at pH 3.0-7.0 and the adsorption increased from 16.0% to 99.2% with increase of adsorbent dose. In addition, two isotherm models, namely. Langmuir and Freunlich were also analyzed to determine the best fit equation for adsorption of Cd(II) on AGCS. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Graft copolymerization Corn stalk Cadmium removal Aqueous solution

来源：评论

学校读者我要写书评

暂无评论

Ball Milling Pretreatment of Corn Stover for Enhancing the Efficiency of Enzymatic Hydrolysis

引用

APPLIED BIOCHEMISTRY AND BIOtechNOLOGY 2010年第7期162卷 1872-1880页

作者： Lin, Zengxiang Huang, He Zhang, Hongman Zhang, Lin Yan, Lishi Chen, Jingwen Nanjing Univ Technol Coll Pharm & Life Sci State Key Lab Mat Oriented Chem Engn Nanjing 210009 Peoples R China Nanjing Univ Technol Coll Sci Nanjing 210009 Peoples R China Zhejiang Univ Coll Mat Sci & Chem Engn Hangzhou 310027 Peoples R China

Ethanol can be produced from lignocellulosic biomass with the usage of ball milling pretreatment followed by enzymatic hydrolysis and fermentation. The sugar yields from lignocellulosic feed stocks are critical parameters for ethanol production process. The research results from this paper indicated that the yields of glucose and xylose were improved by adding any of the following dilute chemical reagents: H2SO4, HCl, HNO3, CH3COOH, HCOOH, H3PO4, and NaOH, KOH, Ca(OH)(2), NH3 center dot H2O in the ball milling pretreatment of corn stover. The optimal enzymatic hydrolysis efficiencies were obtained under the conditions of ball milling in the alkali medium that was due to delignification. The data also demonstrated that ball milling pretreatment was a robust process. From the microscope image of ball milling-pretreated corn stover, it could be observed that the particle size of material was decreased and the fiber structure was more loosely organized. Meanwhile, the results indicate that the treatment effect of wet milling is better than that of dry milling. The optimum parameters for the milling process were ball speed of 350 r/min, solid/liquid ratio of 1:10, raw material particle size with 0.5 mm, and number of balls of 20 (steel ball, I broken vertical bar = 10 mm), grinding for 30 min. In comparison with water milling process, alkaline milling treatment could increase the enzymatic hydrolysis efficiency of corn stover by 110%;and through the digestion process with the combination of xylanase and cellulase mixture, the hydrolysis efficiency could increase by 160%.

关键词： Lignocellulosics Ball milling Pretreatment Enzymatic hydrolysis Corn stover

来源：评论

学校读者我要写书评

暂无评论

Novel Carbohydrate-Binding Module Identified in a Ruminal Metagenomic Endoglucanase

引用

APPLIED AND ENVIRONMENTAL MICROBIOLOGY 2010年第14期76卷 4867-4870页

作者： Duan, Cheng-Jie Liu, Jun-Liang Wu, Xi Tang, Ji-Liang Feng, Jia-Xun Guangxi Univ Coll Life Sci & Technol Nanning 530004 Guangxi Peoples R China Guangxi Univ Guangxi Key Lab Subtrop Bioresource Conservat & U Key Lab Minist Educ Microbial & Plant Genet Engn Nanning 530004 Guangxi Peoples R China Guangxi Acad Sci Natl Engn Res Ctr Nonfood Biorefinery Cellulose Proc Lab Nanning 530003 Guangxi Peoples R China Guangxi Acad Sci Guangxi Key Lab Bioind Technol Nanning 530003 Guangxi Peoples R China

Endoglucanase C5614-1 comprises a catalytic module (CM) and an X module (XM). The XM showed no significant homology with known carbohydrate-binding modules (CBMs). Recombinant full-length endoglucanase could bind Avicel, whereas the CM could not. The XM could bind various polysaccharides. The results demonstrated that the XM was a new CBM.

关键词： CELLULASE HOMOLOGY (Biology) CARBOHYDRATES POLYSACCHARIDES RUMEN (Ruminants) POLYPEPTIDES SUBSTRATES (Materials science) HYDROLYSIS ENZYMES

来源：评论

学校读者我要写书评

暂无评论

Genotypic variation of beta-carotene and lutein contents in tea germplasms, Camellia sinensis (L.) O. Kuntze

引用

JOURNAL OF FOOD COMPOSITION AND ANALYSIS 2010年第1期23卷 9-14页

作者： Wang, Xin-Chao Chen, Liang Ma, Chun-Lei Yao, Ming-Zhe Yang, Ya-Jun Chinese Acad Agr Sci Res Ctr Tea Germplasm & Improvement Tea Res Inst Natl Ctr Tea Improvement China Hangzhou 310008 Zhejiang Peoples R China

Tea is the most popular non-alcoholic healthy beverage in the world, and its water-soluble components such as polyphenols hold important benefits for human health. The lipid-soluble components such as beta-carotene and lutein, however, have not yet been utilized. In order to assess the possibility in using tea leaves as a new source of natural carotenoids, beta-carotene and lutein contents were estimated in new spring shoots of different genotypes and leaf positions of tea plant (Camellia sinensis) using a reverse-phase HPLC approach. There was no significant difference among the three assessed tea varieties (C. sinensis var. sinensis, var. assamica and var. pubilimba) from four different countries (p = 0.549 and 0.092, respectively). But significant differences were found among different leaf positions (maturity). The highest levels of beta-carotene (343.2 mg/kg) and lutein (232.0 mg/kg) were found in C. sinensis var. assamica and, highest coefficient of variation was present in C. sinensis var. sinensis (44.3%). The highest level of beta-carotene content and lutein contents were 42.1 and 16.3 times higher than the lowest among the studied 119 germplasms, respectively. Furthermore, contents of beta-carotene and lutein in mature leaves were higher than young leaves and stems. The results showed that tea may have potential as a new source of carotenoids. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Tea plant Germplasm Camellia sinensis Beta-carotene Lutein Food analysis Food composition

来源：评论

学校读者我要写书评

暂无评论

In vitro engineering of human ear-shaped cartilage assisted with CAD/CAM technology

引用

BIOMATERIALS 2010年第8期31卷 2176-2183页

作者： Liu, Yu Zhang, Lu Zhou, Guangdong Li, Qiong Liu, Wei Yu, Zheyuan Luo, Xusong Jiang, Ting Zhang, Wenjie Cao, Yilin Shanghai Jiao Tong Univ Shanghai Peoples Hosp 9 Shanghai Key Lab Tissue Engn Dept Plast & Reconstruct SurgSch Med Shanghai 200011 Peoples R China Natl Tissue Engn Ctr China Shanghai Peoples R China

Due to the lack of appropriate scaffolds, the in vitro engineering of cartilage tissue with a sophisticated structure, such as a human ear, remains a great challenge. Although polyglycolic acid (PGA) has become one of the most successful scaffolds for cartilage regeneration, how to overcome its limitations in achieving desirable mechanical strength and accurate control over shape remains an unsolved problem. In this study, the mechanical strength of PGA scaffold was enhanced by coating with polylactic acid (PLA). The content of PLA was optimized by balancing the scaffold's biocompatibility and mechanical strength. The PLA/PGA scaffold was then fabricated into a human ear-shape mirror-symmetrical to a normal ear by pressing the scaffold in the ear negative molds, which were fabricated by the computer aided design and manufacturing (CAD/CAM) technique according to the CT scan data from the normal ear. The ear-shaped scaffold reached a similarity level of over 97% compared to the positive ear mold by the shape analysis using a 3D laser scan system. Most importantly, after chondrocyte seeding, the constructs largely retained the original shape during culture with a similarity level of over 84%. Furthermore, the constructs formed ear-shaped cartilage-like tissues at 12 weeks, which revealed a tissue structure with abundant cartilage extracellular matrices and mature lacuna. Additionally, the ear-shaped cartilage at 12 weeks also exhibited fine elasticity and good mechanical strength. These results may provide a useful strategy for reconstructing cartilage tissue with complicated shapes such as a human ear by an in vitro engineering approach. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： Cartilage Human ear CAD/CAM Polyglycolic acid Polylactic acid 3D surface laser scan

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：