Table of Content

20 February 2014 Volume 27 Issue 1

  

Oceanographic Science, Technology and Equipment

Key technology advances on seafloor observatory networks

DU Li-Bin, LI Zheng-Bao, LIU Jie, LYU Bin, QU Jun-Le

J4. 2014, 27(1):  1-8.  doi:10.3976/j.issn.1002-4026.2014.01.001

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      Seafloor observatory networks can achieve longterm and realtime continuous observation in such fields as ocean seabed geology, biology, marine geochemistry and geophysics. This paper reviews research advances on global seafloor cable observatory networks. This paper also addresses their key technologies such as power supply, subsea connection, network infrastructure and project deployment. The paper further presents a preliminary solution. Analysis and prospect are then given for their future development directions.

Physical model based electromagnetic simulation methodology for dynamic ocean surface

ZHOU Bin, LIU En-Xiao, YANG Lei, LIANG Zhi-Heng, TAO Qing-Chang

J4. 2014, 27(1):  9-15.  doi:10.3976/j.issn.1002-4026.2014.01.002

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This paper present an electromagnetic simulation method for sea clutter and targets in view of the difficult accurate modeling of complicated sea surface electromagnetic scenario in microwave ocean remote sensing. We employ a ocean wave spectrum model to reconstruct 3D coarse sea surface, consistent with the actual situation. We can therefore set up the corresponding electromagnetic parameters and recover the real sea environment. We further discretize space and time with FDTD and perform iterative computation. We then calculate the dynamic and realtime electromagnetic distribution. We eventually prove the sea surface model by simulation and present the corresponding electromagnetic distribution status. Simulation experiments show that the method can effectively implement the simulation of a complete eletromagnetic scattering from ocean surface.

TDLAS first harmonic based methane concentration detection system and its temperature compensation

ZHANG Ke-Ke, QI Yong, FU Xiao, MIAO Bin, BAI Xue-Jiao

J4. 2014, 27(1):  16-21.  doi:10.3976/j.issn.1002-4026.2014.01.003

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We analyze the impact of temperature variation on the spectral characteristics of methane absorption line and the concentration measurement of methane gas with the absorption lines in R3 transitions of 2v3 band of methane at 1 653.72 nm. We detect methane gas concentration with first harmonic signal based on tunable diode laser absorption spectroscopy and wavelength modulation spectroscopy. We also suppress the interference of temperature variation on detection accuracy by temperature compensation. Experimental results show that the methane detection system is stable. Its system measurement error is within 1% after the calibration of temperature compensation coefficient, so its system detection accuracy can be effectively improved.

Preparation and detection of the microelectrodes of a carbon nanotube gas sensor

RAN Xiang-Chao, WANG Cheng-Xiang, Wang-Zhi

J4. 2014, 27(1):  22-26.  doi:10.3976/j.issn.1002-4026.2014.01.004

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We devise a parameter optimization based interdigital microelectrodes (IMEs) structure with reasonable electric field intensity distribution. We manufacture the IMEs of 4 μm minimum gap on ITO surface by lithography. This provides a reliable and lowcost manufacturing method for IMEs preparation. We apply the IMEs in a carbon nanotube gas sensor,and detect gassensing properties for it  with ammonia. Results show that the IMEs structure significantly improves the performance of a nanomodified gas sensor.

Article

Impacts of NaCl stress on photosynthesis and PSⅡphotochemical activity of peppermint(Mentha piperita L.)

LI Zhe, WU Xiao-Jing, ZHAO Xiao-Yan, WEI Yan-Li, LI Ji-Shun, YANG He-Tong

J4. 2014, 27(1):  27-33.  doi:10.3976/j.issn.1002-4026.2014.01.005

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We employed portable photosynthesis dectector and chlorophyll fluorometer to address the impacts of different concentrations of NaCl stress on photosynthesis and PSII photochemical activity of peppermint.Results show that concentrationdependent variation exhibits for the growth and biomass of peppermint under NaCl stress.Peppermint can normally grow under 100 and 150 mmol/L NaCl stress.Photosynthesis and PSII photochemical activity of peppermint are significantly decrease and electron transfer between QA and QB is inhibited with the increase of NaCl concentration.The impact of photosynthesis on plant growth and metabolism is quite significant under NaCl stress.PSII is the most sensitive component in a photosynthetic system,and so important in the response of photoynthesis to environmental stress.

Traditional Chinese medicine and natural active products

Separation and extraction of salvianolic acid B from Salvia miltiorrhiza by emulsion liquid membrane

ZHU Rong-Hua, LIU Feng, CUI Li, ZHAO Heng-Qiang, WANG Xiao, ZHANG Shu-Qin

J4. 2014, 27(1):  34-39.  doi:10.3976/j.issn.1002-4026.2014.01.006

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This paper constructed a method for separation and extraction of salvianolic acid B from Salvia miltiorrhiza with W/O emulsion liquid membrane. We obtained an efficient emulsion liquid membrane system by the optimization of internal aqueous NaOH concentration, the content of surfactant Span80, carrier trioctylamine concentration, the ratio of oil phase to internal aqueous solution,the ratio of emulsion phase to external aqueous solution and transport time. The optimal extraction conditions are transport time of 10 minutes, Span80 mass fraction of 4.0%, trioctylamine concentration of 0.01 moL/L, the ratio of oil phase to internal aqueous solution of 10:6, the ratio of emulsion phase to external aqueous solution  of 1:4 and NaOH concentration of 0.012 5 mol/L.Experimental results show that the emulsion liquid membrane system can rapidly and efficiently extract salvianolic acid B from actual samples in the optimal conditions.

Separation and purification of chemical constituents in Herpetospermum pedunculosum seeds by highspeed countercurrent chromatography

HANG Wei, SONG Teng-Fei, DUAN Wen-Juan, WANG Xiao, GENG Yan-Ling, YANG Bing-Tian, ZHANG Qin-De

J4. 2014, 27(1):  40-44.  doi:10.3976/j.issn.1002-4026.2014.01.007

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We originally employed high speed countercurrent chromatography (HSCCC) to separate and purify chemical constituents in ethyl acetate dissolved Herpetospermum pedunculosum seeds. We separated two highpurity chemical compounds with petroleum etherethyl acetatemethanolwater (volume ratio of 2:6:3:5) as solvent, upper organic stationary phase and lower aqueous mobile phase, flow rate of 2 mL/min and rotation speed of 850 r/min. Their HPLC detected purities were more than 95%. The method is simple, rapid, solventsaving and can rapidly and effectively separate and purify the chemical constituents in Herpetospermum pedunculosum seeds.

Article

Preparation of size controlled solid phase extraction adsorbent Ni/Al LDH

LUAN Ling-Yu, CHENG Chuan-Ge, YIN Xi-Xiang, WANG Li-Hong, LI Jian, SUN De-Jun

J4. 2014, 27(1):  45-50.  doi:10.3976/j.issn.1002-4026.2014.01.008

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We prepared Ni/Al layered double hydroxide (LDH) nanoparticles by nonsteady coprecipitation. Water heat treatment process accelerated the crystal of amorphous precipitation. We acquired stable hexagonal sheet Ni/Al LDH nanoparticle colloidal suspensions. We controlled the shape and size of Ni/Al LDH nanoparticles by adjusting peptization temperature and time. We further obtained the optimal peptization temperature of 130 ℃ and peptization time of 24 h for the preparation of Ni/Al LDH nanoparticles. Ni/Al LDH nanoparticles have better adsorption property because of their unique properties of net positive charge and structure and can be manufacured as a solid phase extraction adsorbent. This realizes the combination of nanocomposites with sample pretreatment technology and optimizes sample preprocessing technology.

Evolution and mechanism of the liquid structure of Sb95Bi5 melt

ZHAN Cheng-Wei, ZHOU Ji-Xue, LIU Yun-Teng, LI Wei-Hong

J4. 2014, 27(1):  51-55.  doi:10.3976/j.issn.1002-4026.2014.01.009

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This paper employs liquid metal XRD and resistivity meter to analyze the structure and cluster correlation radius of Sb95Bi5 melt and the resistivity variation with temperature in its temperature dropping process. Experimental results indicate that the cluster correlation radius of Sb95Bi5 melt varies dramatically from 700 ℃ to 675 ℃. Its resistivity temperature coefficient also changes at 698 ℃. This shows that its liquid structure varies in the temperature scope. The reason is that its Peierls transition occurs in temperatue dropping process.

Research advances of microalloying Al-Zn-Mg-(Cu) series aluminum alloy

WANG Xu, WU Si, LIU Yun-Teng, LI Wei-Hong, ZHOU Ji-Xue, TANG Shou-Qiu

J4. 2014, 27(1):  56-62.  doi:10.3976/j.issn.1002-4026.2014.01.010

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Requirement for highperformance aluminum alloy is increasingly severe with the development of aerospace industry. Microalloying is an important approach to improve the mechanical properties of aluminum alloys, and its research has been a global focus. The property of rareearth (RE) elements are active and easy to combine with aluminum alloy matrix and solute elements, so they can effectively improve the microstructure of Al-Zn-Mg-(Cu) aluminum alloy and significantly enhance its comprehensive performance. Microalloying of non rare earth elements can compensate the negatives of that of rare earth elements, so it is widely applied. This paper reviews the function mechanism of rareearth elements Sc, Er, and Ce and regular elements Zr, Ag, Sn, Cr and Sr to the microalloying of Al-Zn-Mg-(Cu) aluminum alloys. We further present some suggestions for the development directions of microalloying of Al-Zn-Mg-(Cu) aluminum alloys.

Impact of pulse pumped on thermal effect of quasi three level Nd:YAG laser crystal

QI Ling-Fei, ZHANG Zhi-Long, HU Wen, LI Jian

J4. 2014, 27(1):  63-67.  doi:10.3976/j.issn.1002-4026.2014.01.011

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We apply pulse laser pumped to the laser crystal of quasi three level system with severe thermal effect. We also introduce a rectangular wave function into a Poisson equation. We further establish the thermal conduction model and its boundary conditions of a cylindrical laser crystal Nd:YAG, based on the convection heat transfer between crystal profile and coolant and the heat transfer between crystal terminal face and externality. We then employ finite element difference method to solve the deformed Poisson equation, and obtain the temperature construction process in the laser crystal and the critical stable temperature field distribution. Results show that pulse pump can significantly decrease the internal temperature of a crystal, and effectively reduce its internal heat effect. This paper provides a reference for the research on the thermal effect of quasi three level and threelevel laser crystal.

Comparative study of approximation performance of numerical optimization improved BP neural networks

DING Shuo, CHANG Xiao-Heng, WU Qing-Hui, YANG You-Lin

J4. 2014, 27(1):  68-72.  doi:10.3976/j.issn.1002-4026.2014.01.012

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We address numerical optimization improved BP neural network algorithms to compare their approximation capabilities. We establish three kinds of numerical optimization improved BP algorithms in MATLAB 7.0. Network training and simulation test are then performed for seven typical numerical optimization improved algorithms with nonlinear function approximation as an example. We compare the approximation performance of different numerical optimization in defferent environments.

Tranfic and Transportation

Strategy model and solution algorithm of railway passenger ticket price

LI Shu-Bin, DANG Wen-Xiu, FU Bai-Bai

J4. 2014, 27(1):  73-77.  doi:10.3976/j.issn.1002-4026.2014.01.013

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Competition exists in multiple intercity transportation means. Ticket price is the adjustment lever for the given requirements. This paper presents a bilevel programming model for railway passenger ticket pricing. We initially construct a variational inequality model that can represent multiclass, multipath cost and multicriteria. It serves as the downlevel model of the bilevel programming model. We then establish the uplevel model of the bilevel programming model with total railway income as an object. We also design a chaosmodified projection algorithm based heuristic algorithm to solve a bilevel programming model. Results show that the proposed ticket pricing mechanism is reasonable. It will provide a better theoretical basis for government railway ticket pricing mechanism.

Rough setdata envelopment analysis based highway development effectiveness evaluation

LI Cheng-Hua, FAN Hai-Bo, ZHU Bo

J4. 2014, 27(1):  78-85.  doi:10.3976/j.issn.1002-4026.2014.01.014

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We select 12 objective indexes to construct an index system of evaluation and analysis of highway traffic development. We initially employ the attribute reduction theory of a rough set to reduce the index system, removing its redundancy index. Models C2R and BC2 of data envelopment analysis (DEA) are then applied to the evaluation for 31 provincial and municipal highway development. We analyze their highway traffic development from scale and technology. Results show that only 11 provinces and cities are effective in scale and technology. Most of them are in progressive decrease of scale and technology.This shows that national sustainable development efficiency of highway traffic is not high, especially for scale efficiency. We not only improve utilization efficiency of domestic highway network, but also highlight the introduction and application of technology in future highway traffic development.

Data envelopment analysis based performance evaluation for a railway transportation corridor

LI Bo-Yi

J4. 2014, 27(1):  86-91.  doi:10.3976/j.issn.1002-4026.2014.01.015

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We employ data envelopment analysis (DEA) to evaluate the performance of a railway transportation corridor to guarantte its efficient operation and optimize corridor resource allocation. We also use  C2R and C2GS2 models of DEA to analyze the overall effectiveness and technical effectiveness of BeijingTianjin railway transportation corridor and evaluate its resource allocation. The method provides quantitative reference for reasonable divisioin of a railway transportation corridor and increases railway transportation quality.

Article

Aging and reclaiming of rubber modified asphalt

CHEN Zhong

J4. 2014, 27(1):  92-97.  doi:10.3976/j.issn.1002-4026.2014.01.016

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We addressed the impact of aging on the properties of rubber modified asphalt with thermooxidative ageing method. We also restored its softening point, penetration and ductility by regenerant addition. Experimental results show that softening point of matrix asphalt and rubber modified asphalt increases, but their penetration and ductility decrease after aging, The attenuation rate of softening point and penetration of matrix asphalt is greater than that of rubber modified asphalt, except that of ductility. Regenerant can restore the properties of rubber modified asphalt, but its softening point and ductility decrease and its penetration slightly increases, as compared with the control sample. Its recovery efficiency gradully reduces for ductility, penetration and softening point.

Lower bounds of the arcconnectivity of a nonmaximally arc-connected digraph

WANG Xiao-Li, WANG Shi-Ying

J4. 2014, 27(1):  98-101.  doi:10.3976/j.issn.1002-4026.2014.01.017

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Let D be a digraph and δ(D) be its minimum degree. Then λ(D)≤δ(D) exists. A digraph D is nonmaximally arcconnected if λ(D)<δ(D). This paper presents the lower bounds of the arcconnectivity of a nonmaximally arcconnected digraph.

Twovariables function S-rough set and its relation theorem

LYU Kun, WANG Lei

J4. 2014, 27(1):  102-105.  doi:10.3976/j.issn.1002-4026.2014.01.018

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We present the mathematical structure and characteristics of two-variables function S-rough sets. We also propose a relation theorem of two-varibles function S-rough sets with one-variable function S-rough sets,S-rough sets, two-variables function rough sets and Pawlak rough sets.

Modified probabilistic density function of a random variable in a limited domain

ZOU Yi, WANG Jun-Jie

J4. 2014, 27(1):  106-109.  doi:10.3976/j.issn.1002-4026.2014.01.019

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We presented a limited domain modification approach for the ideal condition of normal distribution of a random variable. We also proposed two concrete modification results of linear function and quadratic function modification. We further demonstrated the importance of limited domain modification of probabilistic density function in science and engineering, taking the computational method of vesselbridge collision probability in USA AASHTO guide for bridgevessel collision design as an example.