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Preparation and Characterization of Nanocomposite MgFe_2O_4/SiO_2

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Journal of Wuhan University of Technology(Materials Science) 2009年第3期24卷 354-358页

作者：徐莉 College of Science Nanjing Forestry University

Nanocomposites MgFe2O4/SiO2 were successfully synthesized by the sol-gel method in the presence of N, N-dimethylformamide （DMF）. The formation of pure MgFe2O4 was confirmed by powder X-ray diffraction （XRD） and electron diffraction. The structural evolution of MgFe2O4 nanocrystals was followed by powder X-ray diffraction and IR absorption spectroscopy. The formation of spinel structure of MgFe2O4 started at 800 ℃, and completed at 900 ℃, The transmission electron microscopy （TEM） measurements suggest that the particle sizes increase with the increasing annealing temperature, and the mean particle sizes of the spherical samples annealed at 800 ℃, 900 ℃ and 1 050 ℃ are ca. 3.nm, 8 nm and 11 nm, respectively. Magnetization measurements at room temperature and 78 K indicate supemaramagnetic nature of these MgFe2O4 nanocrvstals.

关键词： nanocomposite sol-gel magnesium ferrite magnetic property

Study on lithogeochemistry of Middle Jurassic basalts from southern china represented by the Fankeng basalts from Yongding of Fujian Province

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Science china Earth Sciences 2006年第10期49卷 1020-1031页

作者： ZHOU Jincheng1,2, JIANG Shaoyong1,2, WANG Xiaolei1,2, YANG Jinghong 1,2 & ZHANG Mengqun 3.1. state key Laboratory of Mineral Deposit Research, nanjing University,{3. 2. Department of Earth Sciences, nanjing University,{3. 3. Modern Analysis Center, nanjing University,{3. state key Laboratory of Mineral Deposit Research Nanjing University Nanjing China Department of Earth Sciences Nanjing University Nanjing China Modern Analysis Center Nanjing University Nanjing China

There exists an E-W trending Middle Jurassic volcanic zone in southern china. The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example. The Fankeng basalts have TiO2 contents in the range of 1.92%-3.21%. They are classified as high-Ti basalts. They also have higher total Fe (averaging FeO* = 11.09%). The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cre- taceous basalts from southeastern coast of china. They have higher HFSE, such as Th, Nb, Ta, Zr and Ti. Their element ratios related with HFSE, such as Zr/Ba, La/Nb, La/Ta ,Zr/Y, Ti/Y, Ba/Nb, K/Ti and Rb/Zr are similar to those of OIB. The most samples have ε Nd(T) of-0.70-0.24, which are near chondrite. Some samples have higher ε Nd(T) of ***, these basaltic magmas might be derived from depleted asthenospheric mantle. The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time. The (Early-) Middle Jurassic basalts and gabbros from southeastern Hunan, southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian. Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time. Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.

关键词： interaction between asthenosphere and lithosphere, lithogeochemistry, basalts, Middle Jurassic, southern china.

Sensitive biosensing strategy based on functional nanomaterials

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Science china Chemistry 2011年第8期54卷 1202-1217页

作者： JU HuangXian state key Laboratory of Analytical Chemistry for Life Science Department of Chemistry, nanjing University,{3. state key Laboratory of Analytical Chemistry for Life Science Department of Chemistry Nanjing University Nanjing China

The first decade of the 21st century has been labeled as "the sensing decade". The functional nanomaterials offer excellent platforms for fabrication of sensitive biosensing devices, including optical and electronic biosensors. A lot of works have fo- cused on the biofunctionalization of different nanomaterials, such as metal nanoparticles, semiconductor nanoparticles and carbon nanostructures, by physical adsorption, electrostatic binding, specific recognition or covalent coupling. These biofunc- tionalized nanomaterials can be used as catalysts, electronic conductors, optical emitters, carriers or tracers to obtain the ampli- fied detection signal and the stabilized recognition probes or biosensing interface. The designed signal amplification strategies have greatly promoted the development of stable, specific, selective and sensitive biosensors in different fields. This review in- troduces some novel principles and detection strategies in the area of biosensing, based on functional nanomaterials. The gen- eral methods for biofunctionalization of nanomaterials with biomolecules and their biosensing application in immunoassay of protein, DNA detection, carbohydrate analysis and cytosensing are also described.

关键词： nanobiosensing biosensors nanomaterials biofunctionalization signal amplification bioanalysis biological recognition

Expression of Recombinant Chinese Bovine Enterokinase Catalytic Subunit in P. pastoris and Its Purification and Characterization

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Acta Biochimica et Biophysica Sinica 2004年第7期36卷 513-517页

作者： Lei FANG, Qi-Ming SUN, and Zi-Chun HUA*The state key Laboratory of Pharmaceutical Biotechnology, nanjing University,{3. The state key Laboratory of Pharmaceutical Biotechnology Nanjing University Nanjing 210093 China

Enterokinase is a tool protease widely utilized in the cleavage of recombinant fusion proteins. cDNA encoding the catalytic subunit of Chinese bovine enterokinase (EKL) was amplified by PCR and then fused to the 3. end of prepro secretion signal peptide gene of α-mating factor from Saccharomyces cerevisiae to get the α-MF signal-EKL-His6 encoding gene by PCR. Then the whole coding sequence was cloned into the integrative plasmid pAO815 under the control of a methanol-inducible promoter and transformed GS115 methylotrophic strain of Pichia pastoris. Secreted expression of recombinant EKL-His6 was attained by methanol induction and its molecular weight is 43.kD. Because of the existence of His6-tag, EKL-His6 was easily purified from P. pastoris fermentation supernatant by using Ni2+ affinity chromatography and the yield is 5.4 mg per liter of fermentation culture. This purified EKL-His6 demonstrates excellent cleavage activity towards fusion protein containing EK cleavage site.

关键词： recombinant enterokinase secreted expression Ni2+ affinity chromatography fusion protein cleavage

A self-steering close-talking microphone array

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Progress in Natural Science:Materials International 2005年第11期15卷 1044-1049页

作者： PENG Ke, YANG Xinfeng and XU Boling (state key Laboratory of Modern Acoustics, Institute of Acoustics, nanjing University,{3.) state key Laboratory of Modern Acoustics Institute of Acoustics Nanjing University Nanjing 210093 China

For communication in extremely noisy environments, close-talking microphone arrays are useful. Differential microphone array systems possessing excellent nearfield directivity and strong farfield-noise reduction capability are very suitable for close-talking situations. In order to improve the focusing effect at the desired bearing in the nearfield, we propose a novel self-steering system of close-talking arrays with the first-order differential sub-arrays in this paper. Calculations of directivity patterns and directivity factors show that when a kind of optimized beamforming technique is adopted even small arrays with a focusing configuration will exhibit a satisfactory nearfield directivity which is electronically steerable within a specific range. The superiority of the proposed array system is verified by experiments with real acoustic data.

关键词： close-talking array differential array self-steering directivity factor.

MI-QSAR models for prediction of corneal permeability of organic com-pounds

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Acta Pharmacologica Sinica 2006年第2期27卷 193-204页

作者： Cheng CHEN Jie YANG~2 state key Laboratory of Pharmaceutical Biotechnology,College of Life Science,nanjing University,nanjing 210093.china state key Laboratory of Pharmaceutical Biotechnology College of Life Science Nanjing University Nanjing China

Aim:To derive a theoretical model for the prediction of corneal permeability ofmiscellaneous organic compounds in drug ***:A training set of 28structurally diverse compounds was used to build up the membrane-interactionquantitative structure-activity relationship(MI-QSAR)*** intramolecular solute descriptors were computed using molecular mechanics,molecular dynamics simulations and quantum *** QSAR models wereoptimized using multidimensional linear regression fitting and a stepwise method.A test set of 8 compounds was evaluated using the models as part of a ***:Significant MI-QSAR models(R=0.976,S-0.13.1,F=70.957)ofcorneal permeability of organic compounds were *** permeabil-ity was found to depend upon the sum of net atomic charges of hydrogen atomsattached to the heteroatoms(N,O),the sum of the absolute values of the netatomic charges of oxygen and nitrogen atoms,the principal moment of inertia(X),the Connolly accessible area and the conformational flexibility of the solute-mem-brane ***:The MI-QSAR models indicated that the cornealpermeability of organic molecules was not only influenced by the organic solutesthemselves,but also related to the properties of the solute-membrane complex,that is,the interactions of the molecule with the phospholipid-rich regions ofcellular membranes.

关键词： cornea permeability quantitative structureactivity relationship theoretical models

Study on the Relationship between Lamellar Spacing and Growth Rate inthe Regular Eutectic Growthby Monte-Carlo Simulation

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Journal of Materials Science & Technology 2002年第4期18卷 322-324页

作者： Weimin WANG, Junming LIU and Zhiguo LIULaboratory of Solid state Microstructures, nanjing University, nanjing 210093. china Lab. of Solid state Microstructures Nanjing Univ. Nanjing 210093 China

A modified Monte-Carlo(MC) method to simulate the regular growth of binary eutectic alloys is presented. It is found that the growth rate has a linear dependence on the chemical potential difference between the solid and liquid; the relation between the lamellar spacing A and growth rate R accords well with the prediction of Jackson-Hunt(JH) theory unless the growth rate is very low.

关键词： Eutectic Monte-Carlo simulation Growth

Ultra-microbes are the minerogenetic constructors of oceanic polymetallic nodules

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Chinese Science Bulletin 1997年第8期42卷 617-624页

作者： CHEN Jianlin, ZHANG Fusheng and BIAN Lizeng1 Second Institute of Oceanography, state Oceanic Administration, Hangzhou 3.0012, china 2 Center for Materials Analysis, nanjing University,{3. 3. Department of Earth Sciences, nanjing University,{3. Second Institute of Oceanography State Oceanic Administration Hangzhou China Centu for Materials Analysis Nanjing University Nanjing China Department of Earth Sciences Nanjing University Nanjing China

Polymetallic nodules (mangnese nodules) are a typical kind of manganese oncolites The distribution of smooth sur-face and knobbly manganese nodules is closely related to the geological background of the mine field. A systematic study on their inner laminae structure and features suggests that they are the products of millions of years reproduction and accumulation of the recently found Miniactinomyces chinensis and Spirisophaerospora pacijica .

关键词： oceanic manganese nodule stromatolite ultra-microbe biolite.

Differential AR algorithm for packet delay prediction

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Progress in Natural Science:Materials International 2006年第4期16卷 437-440页

作者： JIAO Liangbao, ZHANG De and BI Houjie Institute of Acoustics, state key Laboratory of Modern Acoustics, nanjing University,{3. Institute of Communication Technique, nanjing University,{3. Institute of Acoustics State Key Laboratory of Modern Acoustics Nanjing University Nanjing 210093 China Institute of Communication Technique Nanjing University Nanjing 210093 China

Different delay prediction algorithms have been applied in multimedia communication, among which linear prediction is attractive because of its low complexity. AR (auto regressive) algorithm is a traditional one with low computation cost, while NLMS (normalize least mean square) algorithm is more precise. In this paper, referring to ARIMA (auto regression integrated with moving averages) model, a differential AR algorithm (DIAR) is proposed based on the analyses of both AR and NLMS algorithms. The prediction precision of the new algorithm is about 5-10 db higher than that of the AR algorithm without increasing the computation complexity. Compared with NLMS algorithm, its precision slightly improves by 0.1 db on average, but the algorithm complexity reduces more than 90% . Our simulation and tests also demonstrate that this method improves the performance of the average end-to-end delay and packet loss ratio significantly.

关键词： AR algorithm NLMS algorithm differential AR algorithm ARIMA model.