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Three-dimensional subwavelength components utilizing THz surface plasmons

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Science china(Information Sciences) 2012年第1期55卷 79-89页

作者： ZHOU YongJin,JIANG Quan&CUI TieJun state key laboratory of millimeter waves,School of Information Science and Engineering,Southeast University,nanjing 2.0096,china state key laboratory of millimeter waves School of Information Science and Engineering Southeast University

Since surface plasmons(SPs)are not constrained by the diraction limit,they have important potential applications in the optical,terahertz(THz),and microwave *** this paper,we firstly present a review of three-dimensional(3D) bidirectional and multi-directional THz SP splitters based on the rectangular metallic groove gratings with finite thickness,in which a metallic wire was used to excite the THz *** experimental verifications of such splitters have been implemented in the microwave frequencies,and the measurement results have excellent agreements to the full-wave *** improve the performance,a 3D bidirectional THz SP splitter with the transverse confinement and a 3D bidirectional bending THz SP splitter are then proposed,which have shown very good splitting performance,compact sizes,and better transverse confinement of EM ***,a broadband slow-wave system of subwavelength thickness is reviewed and a new bending slow-wave system utilizing THz SPs is *** and simulations in microwave frequencies have good agreements,showing the validity of these components.

关键词： surface plasmons surface waves terahertz slow wave splitter

Accurate location of all surface wave modes for Green's functions of a layered medium by consecutive perturbations

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Science china(Information Sciences) 2010年第11期53卷 2363-2376页

作者： SONG Zhe, ZHOU HouXing, HU Jun, LI WeiDong & HONG Wei state key laboratory of millimeter waves, School of Information Science and Engineering, Southeast University, nanjing 2.0096, china state key laboratory of millimeter waves School of Information Science and Engineering Southeast University

In this paper, an efficient method is proposed to quickly and accurately locate all the surface wave modes of spectral Green’s functions of a layered medium. This method consists of two parts. In the first part, all the surface wave poles without considering the medium loss are located by a modified dichotomy on the real axis in the complex plane. In the second part, consecutive perturbations with respect to the medium loss are performed, which means that the medium loss is increased step by step from zero to the given value, and at each step, the Newton-Raphson algorithm is employed to find all the current poles, with the poles at the previous step as initial values. The residues of the surface wave poles are analytically calculated without any contour integral. The whole procedure is based on the recursively rational forms of spectral Green’s functions. As an application, all the surface wave poles and their residues obtained by the method proposed in this paper are applied in evaluation of the spatial Green’s functions by the discrete complex image method. Some numerical examples are provided to validate the correctness and efficiency of the proposed method.

关键词： Green’s function Sommerfeld integral surface wave pole perturbation discrete complex image method

A study on methane coupling to acetylene under the microwave plasma

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Science china Chemistry 2010年第1期53卷 231-237页

作者： SHEN ChangSheng1,SUN YongZhi1,SUN DeKun2 & YANG HongSheng1 1state key laboratory of millimeter waves School of Electronic Science and Engineering,Southeast University,nanjing 2.0096,china 2School of Chemistry and Chemical Engineering,nanjing University,nanjing 210093,china state key laboratory of millimeter waves School of Electronic Science and Engineering Southeast University Nanjing China School of Chemistry and Chemical Engineering Nanjing University Nanjing China

By optimizing the microwave chemistry reactor made of the rectangular waveguide resonator,the methane conversion(the maximum 93.7%),the C2 hydrocarbon yield(the maximum 91.0%) and the acetylene yield(the maximum 88.6%) were all greatly increased under the microwave ***,for the optimal reactor,the change of the methane conversion and the C2 hydrocarbon yield is little within the range of the pressures in the *** C2 hydrocarbon is mainly made up of acetylene,and the selectivity for acetylene is above 90%.Energy yield and space time yield of acetylene are also *** emission spectroscopy(OES) was adopted for the diagnosis of methane coupling to acetylene under microwave *** excited species(CH,C2,H2,Hα) were detected in the spectra range of 300-750 *** on the products and the excited species,the reaction mechanism of methane coupling under microwave plasma was investigated,using the thermodynamics and kinetics of the chemical reaction.

关键词： microwave plasma methane acetylene

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, nanjing 210093, china 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, nanjing 210093, china 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 neotype for Colpodexylon gracilentum Dou (Lycopsida) from the Middle Devonian of North Xinjiang,china

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Journal of Systematics and Evolution 2011年第4期49卷 372-378页

作者： Hong-He XU Yi WANG (state key laboratory of Palaeobiology and Stratigraphy,nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,nanjing 210008,china) ( state key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China)

According to newly collected and well preserved specimens,herbaceous lycopsids Colpodexylon gracilentum Dou and Colpodexylon laminatum Dou from the late Middle Devonian of Xinjiang,NW china are reduced to ***,for which a neotype is designated and emended diagnosis is *** gracilentum has leaves with three nearly equal segments,an elliptical sporangium adaxially attached by a pad on the isomorphic sporophyll.

关键词： Colpodexylon Devonian lycopsid neotype Xinjiang.

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, nanjing 210093, china) 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.

Advances of multiplex and high throughput biomolecular detection technologies based on encoding microparticles

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Science china Chemistry 2011年第8期54卷 1185-1201页

作者： ZHAO XiangWei, ZHAO YuanJin & GU ZhongZe state key laboratory of Bioelectronics Southeast University, nanjing 2.0096, china state key laboratory of Bioelectronics Southeast University Nanjing 210096 China.

The rapid developments of genomics and proteomics have driven the demand for multiplex and high throughput analysis of large numbers of biomolecules in the fields of medical diagnostics, drug discovery, and environmental monitoring. Encoding the biomolecular binding events is the key technique to fulfill this demand, in which microparticles play the most important roles. This review outlines the development of multiplex and high throughput biodetections, and highlights the most recent advances in the field of encoding microparticles, together with problems that need to be resolved.

关键词： multiplex bioassays multiplex labels encoded microcarrier binding assays high throughput screening

EXPERIMENT OF IMPACT OF RIVER HYDRAULIC CHARACTERISTICS ON NUTRIENTS PURIFICATION COEFFICIENT

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Journal of Hydrodynamics 2007年第3期19卷 387-393页

作者： WANG Pei-fang WANG Xiao-rong WANG Chao state key laboratory of Pollution Control and Resource Reuse School of Environment Nanjing University Nanjing 210093 China state key laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China key laboratory of Intergrated Regulation and Resource Development on Shallow Lakes College of Environmental Science and Engineering Hohai University Nanjing 210098 China

Hydraulic characteristics of a river are the key factors for river water quality improvement and river restoration. A simulated river was exploited to study the interactions between water contaminant purification coefficients and the characteristics of the river, such as the cross-section velocity, water depth, Reynolds number, and Froude number. To enhance the purification capacity of the river, detritus with 5 mm to 10 mm in diameter and contact surface area per volume of 87.6 m^2/m^3 were constructed naturally at the bed and along one side of the bank to form half shape of the river cross-section. During the one-month experiment （including 3 periods） from the third of November to the fourth of December, 2005, three categories of hydraulic conditions were investigated. Results show that the purification coefficient （K） of Total Nitrogen （TN） is closely coherent with the hydraulic retention time （T）, river length （L）, Reynolds number （Re） and Froude number （Fr）. The relationship of K and T generally agrees with the power law under the three experimental water hydraulic conditions. Based on these results, the optimal Re and Fr ranges can be obtain to serve as a guideline for ecological re-engineering design to improve river water quality and restore river ecosystem.

关键词： Hydraulic characteristics total nitrogen,purification coefficient interaction simulated river