Journal of Shanghai University（Natural Science Edition）

Experiment of Failure Mechanism of High Temperature Bonded Fiber Grating Sensor

DU Chong, PENG Tao, HUO Shi-yu, XIE Wei-hua, MENG Song-he

2013, 19(6): 551-555. doi:10.3969/j.issn.1007-2861.2013.06.001

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As the temperature resistance of fiber grating improving, the potential application of the fiber grating sensor in the high temperature thermal structure field is increasingly apparent. The high temperature bonding method is one of the most simple and effective methods to apply fiber grating sensors. However, the
high temperature environment may cause various high temperature adhesive failures. The bonding properties of fiber grating sensor and ultra high temperature ceramic are studied in high temperature tensile and shear experiments, and the high temperature bonding failure mechanisms are studied by macro and micro fracture morphology observations. The results show that the bonding failure is a mixed failure mode including interface damage and cohesive failure at two temperatures 500 and 650 ℃, and mainly adhesive cohesive failure, while at 650 and 800 ℃, bonding failure is mainly interface failure. Under a thermal and mechanical load, holes in the adhesive gradually develop to the crack weakening tensile strength, and simple high temperature heat treatment can improve the bonding performance.

Numerical and Physical Simulation on Flow in Mold with EMBr in Continuous Casting of Slab

CHANG Tong-xu, JIA Hao, ZHANG Zhen-qiang, DENG Kang, REN Zhong-ming

2013, 19(6): 556-561. doi:10.3969/j.issn.1007-2861.2013.06.002

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Combined with a mercury experiment, a Reynolds time-average model was applied to investigate the effects of magnetic flux density on flow in the mold cavity with different electromagnetic braking (EMBr) and on the process. The results show that the Reynolds stress model (RSM) can accurately reflect flow changes of the mold with EMBr. Nozzle jet profile and washing intensity to the thin wall of mold are varied with alteration of magnetic flux density. The upper portion of the magnetic field can obviously inhibit the surface horizontal velocity and turbulence. However, considering the melting of powder and impingement depth, the upper portion of the magnetic flux density should not be too high.

Heat Resistance of Cured Arylacetylene Modified by Siloxane

2013, 19(6): 562-566. doi:10.3969/j.issn.1007-2861.2013.06.003

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In order to introduce Si into poly arylacetylene (PAA), siloxane was used to blend with arylacetylene.The structure and thermal stability of the cured arylacetylene/siloxane were studied. Effect of boiling on the thermal stability of the cured arylacetylene/siloxane was also investigated. The results show that thermal stability of the cured arylacetylene/siloxane in N2 is weaker than PAA, which is affected by the amount of siloxane. Thermooxidative stability of the cured arylacetylene/siloxane is improved with an increase of siloxane. For the cured resins (m_AA ∶ m_VTMS=10 ∶ 5, where VTMS is vinyl trimethoxy siloxane), the residue yield at 800 ℃ in air is 23.6%. After boiling, thermal stability of the cured arylacetylene/siloxane is improved further.

Electrical Properties Optimization of 50 V HVPMOS Based on 0.35 μm BCD Process

ZOU Rong1, MIN Jia-hua1, CHU Chu2, LIANG Xiao-yan1, ZHANG Tao1, TENG Jia-qi1

2013, 19(6): 567-571. doi:10.3969/j.issn.1007-2861.2013.06.004

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This paper aims to improve the electrical properties of 50 V HVPMOS using the 0.35 μm 30_40_50 V BCD (bipolar-CMOS-DMOS) process by adjusting the dimensions of device structure without changing the original process. The process and device simulation of Silvaco Inc. has been used to analyze the influences of the channel length, overlap size, field oxide layer length and field plate length on the electrical properties of 50 V HVPMOS. The optimized dimensions were determined according to the simulation results, and feasibility of the optimization scheme was verified by the result of tape out. The test results show that the threshold voltage reduces to –0.98 V, the breakdown voltage increases to –68 V, the specific on-resistance is reduced by 13.5% and the saturation current is increased by 13.1% after the optimal design. Furthermore, the saturated zone is smoother without obvious kink effect.

Reaction Pathways of Reforming of Methane over NiO/MgO Catalyst in Oxygen Permeation Membrane Reactor

YANG Zhi-bin1, DING Wei-zhong2

2013, 19(6): 572-578. doi:10.3969/j.issn.1007-2861.2013.06.005

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Reforming reaction of methane was carried out in an oxygen permeation membrane reactor, and fed with methane and Ar. A comparative analysis of the oxygen permeation performance under the condition of CH₄ diluted by Ar with 1 g 9% Ni/γ -Al₂O₃ catalyst and without catalyst was performed to investigate the reaction pathways. According to the results, the reaction pathways are deduced. The dissociation of CH₄ on catalyst first formed surface C species and H₂. The producted H₂ is then reacted with oxygen diffused or spilt over catalyst from membrane to form H₂O, causing the oxygen partial pressure to decrease, and the flux of oxygen to increase. This paper further shows the pathways of CH4 dissociation and H₂ oxidation, through catalytic partial oxidation of methane over NiO/MgO catalysts with different Ni contents in an oxygen permeation membrane reactor.

Characteristics of Thin Film Flow on Cylinder Driven by Electro-osmosis

LI Jun, HU Guo-hui

2013, 19(6): 579-584. doi:10.3969/j.issn.1007-2861.2013.06.006

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A thin film flow on a cylinder driven by electro-osmosis in direct current (DC) and alternating current (AC) electric field are analytically investigated respectively. Analytical solutions of electric potential and flow velocity are obtained by solving viscous incompressible hydrodynamic equations coupling with linearized
Possion-Boltzmann equation based on the leaky dielectric model and the Debye-H¨uckel approximation. In a DC electric field, the dimensionless flow velocity just differs from the electric potential by a constant. The flow velocity on free surface only depends on a ratio α between the electric potential on the free surface and the potential on the cylindrical surface. In an AC electric field, the results show the amplitude of flow velocity. The phase difference between flow velocity in flow field and that in the electrical double layer is closely related to the Reynolds number. Amplitude of flow velocity in an AC periodic electric field is similar to that in a DC steady electric field in low Reynolds number. With the increase of the Reynolds number, the amplitude of flow velocity decreases near the solid surface, while the phase difference increases. The amplitude of flow velocity on a free surface decreases/increases as the Reynolds number increases for low/high α.

Experimental Investigation on Evacuation from Classroom Considering Internal Layout and Exit Width

DUAN Xiao-yin1, DONG Li-yun1,2, WANG Gan-yun1, WEI Yan-fang1,3,TIAN Huan-huan1,3

2013, 19(6): 585-590. doi:10.3969/j.issn.1007-2861.2013.06.007

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The process of evacuation from a classroom is investigated experimentally for three kinds of exit width and four kinds of internal layout. Spatial distribution of evacuation time is obtained to analyze evacuation efficiency. In case of double-desks, people tend to enter the nearest aisle. The arrangement of desks determines upstream flow from aisles and the exit width determines the flow capacity, both affecting the evacuation time. The evacuation time decreases with the increase of number of aisle, but not always so. For a classroom with a fixed width, more aisles are beneficial to evacuation. However, the reduced aisles width may cause conflicts between peoples from both sides. In case of small exit, congested area occurs at the exit and the evacuation time increases significantly. The evacuation process can be improved by controlling upstream flow and reducing conflicts among people.

Numerical Simulation on Mechanism of Contaminant Release Through Sediment-Overlying Water Interface

ZHENG Shu-jun, GUO Jia-hong, WANG Dao-zeng

2013, 19(6): 591-597. doi:10.3969/j.issn.1007-2861.2013.06.008

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After external pollutant discharge is reduced, release of contaminant from sediment to overlying water may cause contamination to the river and lake again. The mechanism of contaminant release through the sediment-overlying water interface is studied under the condition that the overlying water flow does not lead to sediment suspension. The overlying water flow is calculated using the k-ε turbulence model. The sediment is regarded as an isotropic homogeneous porous medium. Therefore the seepage field in the porous sediment layer is obtained by solving the Darcy’s aligns. Several two dimensional coupled steady flow fields of the overlying water and the pore water in the sediment are calculated. Based on the flow fields obtained, the unsteady contaminant solute transportation process in the sediment and the overlying water is numerically simulated, with the shapes of the sediment-overlying water interface being flat or periodic triangular respectively. Numerical results show that exchange of the pore water and the overlying water is an important factor that decides the release flux of contaminant from the sediment to the overlying water.

Light Extinction Properties of Granular Gas in Vacuum Deposition Process

HUANG Kai1,2, WANG Zhi-liang1,2, ZHOU Zhe-wei1,2, ZHANG Jin-song3, ZHANG Jian-hua3

2013, 19(6): 598-605. doi:10.3969/j.issn.1007-2861.2013.06.009

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Assume that the vapor of organic polymers in a vacuum deposition process is composed of spherical particle by coarse graining to form a multiple particle system, and consider extinction properties of light for such a system consisting of up to 3 000 randomly distributed particles. The generalized Lorenz-Mie theory from electromagnetic theory is used. The results show that, with the increase of the size and number of primary particles, the extinction coefficients go up at the beginning and fall down afterwards, indicating the presence of maximum values in the extinction coefficients. The energy of a plane incident wave decays faster than that of a Gaussian wave. Properties of electromagnetic fields under different primary particle sizes are also studied.

η-Hermitian Solutions to a System of Quaternion Matrix Equations

CHEN Di1,WU Wei-feng2

2013, 19(6): 606-610. doi:10.3969/j.issn.1007-2861.2013.06.010

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This paper derives a necessary and sufficient condition for the existence of the η-Hermitian solutions to the quaternion matrix equationsAXA^η∗+ BYB^η∗= E, CYC^η∗+ DZD^η∗= F by using the singular value decomposition of four matrices, and gives an expression of the η-Hermitian solutions to the quaternion matrix equations.

Solid Phase Microextraction Detection for Phthalate Estersin Environmental Water

WU Ming-hong, SHI Qian-hui, XU Gang, QIAN Dong-ying

2013, 19(6): 611-614. doi:10.3969/j.issn.1007-2861.2013.06.011

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A solid phase microextraction-gas chromatography mass spectrometry (SPME-GC/MS) method was developed to determinate 6 phthalate esters (PAEs) in water. The optimum conditions, fibers, time, temperature and pH values were studied. The detection limits were 3.7∼8.5 ng/L, and the correlation coefficients were more than 0.991 in linear range 20∼500 ng/L. Recoveries were 83%∼112% and relative standard deviations (RSDs) were 1.1%∼12.3%. The SPME-GC/MS method is simple and fast, and can give high sensitivity qualitatively and quantitatively in detecting PAEs in environmental water.

Ammonia Escape in Flue Gas Desulphurization by Ammonia Method

SONG Gui-dong, WAN Hao, SHAO Shen, CHAN Wen-bing, GU Xiao-jing

2013, 19(6): 615-618. doi:10.3969/j.issn.1007-2861.2013.06.012

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In the simulation of flue gas, free ammonia at the export of spray tower was used as the monitoring object. Factors of influence including pH value and concentration of absorption liquid, volume ratio of liquid to gas (L/G) and inlet gas temperature on the efficiency of flue gas desulphurization (FGD) were studied. Experimental results show that the amount of ammonia escape increases as the pH value, concentration of absorption liquid and L/G increase. To control ammonia escape and the high rate of desulphurization, appropriate parameters should be used, including pH value of 6.0, concentration of absorption ((NH4)2SO3) of 1%, L/G of 4 L/m³, and inlet gas temperature of 90~110 ℃.

Influence of Particle Diameter on Performance of Blast Furnace Slag Cement

YAN Li-jun1,2, GE Tan-tan1, YAN Xiao-juan1, HE Chen1, LI Di1, HU Xue-feng1

2013, 19(6): 619-622. doi:10.3969/j.issn.1007-2861.2013.06.013

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As an inevitable by-product of the steel industry, blast furnace slag increases rapidly with the fast growth of production. To protect the environment and creat more economic benefit, it is important to carry out theoretical studies on slag cement. It is shown that hydration reaction and the compressive strength of
concrete increase with decrease of the particle size of blast furnace slag powder. The particle size distribution of blast furnace slag has a significant impact on the mechanical strength of cement.

Isolation, Sequence Analysis and Prokaryotic Expression of a Putative Transcriptional Factor ZmbHLH5 from Maize (Zea mays)

WANG Fang, ZHONG Ming-yu, SONG Ren-tao, XU Zheng-kai, WANG Gui-feng

2013, 19(6): 623-630. doi:10.3969/j.issn.1007-2861.2013.06.014

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Based on expressed sequence tags (ESTs) isolated from the cDNA library of maize developing kernels, a full-length putative basic helix-loop-helix (bHLH) transcription factor, named ZmbHLH5 was cloned successfully. Sequence analysis showed that ZmbHLH5 cDNA was 1 389 bp in length with an open reading frame (ORF) encoding 211 amino acids and untranslated regions (UTR) of 329 and 433 bp at the 3′and 50-ends, respectively. The protein encoded by ZmbHLH5 had high homology with bHLH transcription factors of other plants, ranging from 68% to 87%, with a conserved 60 amino acids bHLH domain. Expression pattern demonstrated that ZmbHLH5 was expressed at high level in ear and early developing kernels, and at least three ZmbHLH5 isoforms were produced by alternative splicing during kernel development. The fused protein GST-ZmbHLH5 was successfully expressed in prokaryotic expression system with an expected molecular weight of 58 kD.

Construction of Recombinant Eukaryotic Expression Vector for PinX1 and Its Roles in Inhibiting Proliferation of Human Breast Cancer MCF-7 Cell Line

HU Zong1, LIANG Sang-hua2, MA Wen-li1,2, ZHENG Wen-ling1,3

2013, 19(6): 631-635. doi:10.3969/j.issn.1007-2861.2013.06.015

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This paper explores the effects of PinX1 gene on the growth and the cell cycles of breast carcinoma cell line MCF-7 and the potential in treatment of breast cancer. The PinX1 mRNA was amplified from 293-T cell with RT-PCR and inserted into pEGFP-C1 vector. The recombined eukaryotic expression vector of PinX1 was confirmed by enzyme digestion, and transfected into the breast carcinoma cell line MCF-7 using a liposome method. The expressed mRNA was detected by real-time PCR, and the cell growth and cell cycles by MTT and flow cytometry, respectively. Results showed that PinX1 transfection into the breast cancer MCF-7 cell line was stable and the transfected gene was integrated into nucleolus DNA of transfected cells. Transfection of PinX1 gene could significantly inhibit the growth and proliferation of breast cancer cells (P < 0.05) and the cell growth was arrested at G0/G1 stage. The conclusion is that PinX1 gene could inhibit growth and proliferation of breast cancer cells.

Effects of Cadmium on Callus Induction and Regeneration from Mature Embryos of Creeping Bentgrasses

DENG Yi-fei, DAI Jia-ying, WU Wen-jun, ZHANG Wen-ju, CHEN Qin, DENG Zhi-rui

2013, 19(6): 636-640. doi:10.3969/j.issn.1007-2861.2013.06.016

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The effects of different cadmium ion concentrations on callus induction, growth and plantlet regeneration of creeping bentgrass were studied. When cadmium ion concentration in medium was below 2.50 mg/L, the induction frequency was higher than that of control. The induction frequency reached up to 83.3% when cadmium ion concentration in medium was 2.50 mg/L, indicating that low cadmium ion concentration may have stimulating effect on callus formation. As cadmium ion concentration increased, the induction frequency remarkably declined and callus formation was completely inhibited when cadmium ion concentration was over 50.00 mg/L. In the early days of the callus growth (0~30 d), the calli on the medium containing 12.50 mg/L cadmium ion were morphologically largest, and further prolonged growth (30~45 d) exhibited that one lower concentration (2.50 mg/L) gave stronger stimulating effect. During regeneration, regenerated seedlings grew best on the medium where 1.25 mg/L cadmium ion concerntration existed.

Effect of Low Frequency Pulsed Magnetic Field on Lactobacillus casei LC2W

ZHANG Yi-kai1, LIAO Xian-yan1, WU Zheng-jun2, HOU Jian-ping2, WENG Xin-chu1

2013, 19(6): 641-646. doi:10.3969/j.issn.1007-2861.2013.06.017

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Lactobacillus casei LC2W was irradiated by low frequency pulsed magnetic field (LFPMF) with maximum strength of 5 T. The effect of LFPMF on the cell growth and cell activity were investigated. Some correlation index of bacteria cell membrane irradiated by LFPME were also detected, including the resistance
to ultrasonic, cell membrane permeability to carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and the composition of the fatty acids. The results suggest that LFPMF can inhibit growth of the cells and reduce the activity of cells. The survival rate of the cells irradiated by LFPMF increased by 37.9% after ultrasonic processing by 30 min, the permeability of the cell membrane reduced by 20.3%, the unsaturated fatty acids of the cell membrane was increased from 1.53 to 2.07. The results indicate that LFPMF has significant effect on the composition and structure of LC2W’s cell wall and cell membrane.

Model Predictive Direct Current Control of Induction Motor at Low Switching Frequency

SONG Wen-xiang, RUAN Zhi-yong, ZHU Hong-zhi, ZHOU Jie

2013, 19(6): 647-653. doi:10.3969/j.issn.1007-2861.2013.06.018

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This paper proposes a model predictive direct current control (MPDCC) method for low switching frequency control of induction motors fed by a neutral point clamped (NPC) three-level inverter. Based on a discrete-time internal predictive model of the drives, the controller predicts future trajectories of stator current
for each admissible switching position, extrapolates the output trajectories and selects the optimal switch vector according to a receding horizon policy of the cost function that evaluates the average switching frequency of inverter. This makes the switching frequency minimized and the predicted current trajectories within its specified hysteresis bounds. Compared with the established one-step predictive current control, the proposed scheme can reduce switching frequency significantly, and keeps similar harmonic characteristics. Simulation results show that the switching frequency of the three-level inverter can be dropped below 500 Hz. A low harmonic distortion rate of three-phase current is achieved, and fast transient response can be realized by using the proposed scheme.

Owner-Based Integrated Management of Materials in Large-Scale Chemical Piping Project

JIN Xia-jie, LIN Cai-xing

2013, 19(6): 654-660. doi:10.3969/j.issn.1007-2861.2013.06.019

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Material management is an important part in the management of chemical piping projects. This paper discusses the characteristics of material management for large-scale chemical piping projects, supported by modern information technology. An integrated control and management model is built, and the method of modeling is studied. Using practical cases, applications of the model are studied. The owner-based material integrated management model can realize the all-life-cycle material management of piping engineering projects, providing a useful construction method and ideals for large-scale engineering material integrated management.

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