Loading...
Welcome to Journal of University of Chinese Academy of Sciences,Today is

Current Issue

2014, Vol.31, No.1 Previous Issue    Next Issue
Research Articles
Some remarks on the linearly dependent problem and linear triangularizability
SUN Pengju, YAN Dan, TANG Guoping
2014, 31 (1): 1-4.  DOI: 10.7523/j.issn.2095-6134.2014.01.001
Abstract ( 1046 ) PDF (KB) ( 5 )

In this paper, we first show that the homogeneous parts of the quadratic-linear Keller maps are linearly dependent under certain conditions. Then we give an equivalent statement about the linearly triangularizable polynomials. Finally, we show that a polynomial F is linearly triangularizable if (J(F-X))2=0 and n≤3.

Positive solutions to Kirchhoff-type problem with singular nonlinearity
CAO Xiaoqiang, SUN Yijing
2014, 31 (1): 5-9.  DOI: 10.7523/j.issn.2095-6134.2014.01.002
Abstract ( 1201 ) PDF (KB) ( 6 )

We consider the following problem:
where a>0,b>0,1<p<+∞, and f is a positive and measurable function defined on Ω. The necessary and sufficient condition for the existence of weak solutions to such a Kirchhoff-type problem is given.

Interior Morrey estimates for divergence degenerate elliptic systems in Carnot groups
ZHU Maochun, FENG Xiaojing
2014, 31 (1): 10-16.  DOI: 10.7523/j.issn.2095-6134.2014.01.003
Abstract ( 1101 ) PDF (KB) ( 3 )

Let X1,…,Xq be the basis of the space of horizontal vector fields on a homogeneous Carnot group G =(R n,o) (q<n). The interior Morrey estimates for weak solutions to the following divergence degenerate elliptic system
10???
are obtained when the coefficients aαβij satisfy the strong Legendre condition in Ω⊂ G and belong to the space VMOloc(Ω).

Spin conductance in ferromagnet/quantum dot/superconductor junctions
NING Wenting, JIN Biao
2014, 31 (1): 17-23.  DOI: 10.7523/j.issn.2095-6134.2014.01.004
Abstract ( 1176 ) PDF (KB) ( 3 )

We analyze the spin transport in a ferromagnet/quantum dot/superconductor junction by assuming spin-flip interaction on the quantum dot. The nonequilibrium Green's function method is employed to calculate the tunneling spin current and spin conductance. It is shown that the spin conductance depends sensitively on the orientation of exchange field in the ferromagnet, leading to a controllable giant spin tunneling magnetoresistance effect, even in the moderate temperature and spin polarization regime.

Numerical study on the fluid-structure interaction of the heaving orthotropic membrane
SUI Xiaofei, GUAN Ziwu, BAO Lin
2014, 31 (1): 24-31.  DOI: 10.7523/j.issn.2095-6134.2014.01.005
Abstract ( 1062 ) PDF (KB) ( 5 )

Fluid-structure interaction of the orthotropic rectangular membrane during heaving motion is simulated numerically by using a nonlinear finite element method combined with an unsteady panel method. The numerical results are analyzed to understand the influence of flexibility on the aerodynamic performance of the heaving membrane at a small angle of attack. It is indicated that the amplitudes of the deformations increase considerably as the chordwise and the spanwise elastic moduli decrease, which leads to an increase of average aerodynamic lifts at the cost of the slight decrease of the ratio of average aerodynamic lift to power.

Comparative study on sensitivities of frequency-domain thermoreflectance methods during the thin-film material thermophysical property measurement
XU Xianfeng, TANG Dawei
2014, 31 (1): 32-37.  DOI: 10.7523/j.issn.2095-6134.2014.01.006
Abstract ( 1567 ) PDF (KB) ( 8 )

Based on Fourier's thermal conduction law, we deduced theoretical phase expressions with respect to frequency in continuous-wave and pulsed frequency-domain thermoreflectance(FDTR) methods by a transfer matrix thermal analysis way. Comparisons of sensitivities between the two methods in two common types of systems are made, and the results lead to theoretical basis for selection of FDTR methods in experimental measurements. The results show that high accuracies of film material thermal properties in experimental test are available with an appropriate FDTR method as well as the best frequency range for fitting.

Analysis of glutathione in cells by microchip electrophoresis coupled with electrochemical detection
YAO Lin, WU Liangqi, DING Yongsheng
2014, 31 (1): 38-45.  DOI: 10.7523/j.issn.2095-6134.2014.01.007
Abstract ( 1086 ) PDF (KB) ( 5 )

We established a new method for simultaneous determination of reduced and oxidized glutathione. The separation and detection conditions were optimized in terms of the buffer pH, buffer concentration, SDS concentration, separation potential, injection time, and detection potential. Under the optimized condition, GSH and GSSG were separated within 3 min, and the satisfactory linear ranges were 5~200 and 2~100 μmol/L for GSH and GSSG, respectively. The detection limits of GSH and GSSG were 4.87 and 1.98 μmol/L, respectively. Quantitative analyses of GSSG and GSH in cells were performed with satisfactory results.

Effects of nitric oxide on the biosynthesis of shikonin and its derivatives in callus of Arnebia euchroma
HAO He, YE Hechun, WANG Hong
2014, 31 (1): 46-53.  DOI: 10.7523/j.issn.2095-6134.2014.01.008
Abstract ( 1288 ) PDF (KB) ( 6 )

Nitric oxide (NO) is an important signal molecule involved in the regulation of plant secondary metabolism. In this study, SNP (sodium nitroprusside) was utilized as the donor of nitric oxide to treat Arnebia euchroma callus. We find that the expression levels of the genes involved in the biosynthesis of shikonin and its derivatives, such as AePGT, AeGPPS, AeC4H, and Ae4CL, increase significantly in SNP-treated Red Strain callus tissues. Meanwhile, SNP treatment also increases the contents of some shikonin derivatives. The above-mentioned results indicate that exogenous NO increases the biosynthesis of shikonin and its derivatives by up-regulating the expression of the genes.

Experiments on fluid flow and solute transport in the fracture network pipe model
TENG Qiang, WANG Mingyu, WANG Huifang
2014, 31 (1): 54-60.  DOI: 10.7523/j.issn.2095-6134.2014.01.009
Abstract ( 1106 ) PDF (KB) ( 6 )

It is important to understand groundwater flow and solute transport in fractured rocks for establishing appropriate groundwater protection policies and implementing effectively protection measures. Based on the discrete fracture network model and fracture network pipe flow model, a representative physical model was built and a set of the laboratory experiments were carried out in order to investigate the correlations of flow discharge and solute transport mass with fracture geometry parameters. On the basis of the correlation analyses and regression analyses, we obtained the corresponding regression trends and statistical relationships.

Phosphorus recovery from urine automatically collected from urinal based on source separation of urine from flushing water
MENG Xianchao, HU Zhengyi, LIU Xiaoning, WEN Guoqi
2014, 31 (1): 61-66.  DOI: 10.7523/j.issn.2095-6134.2014.01.010
Abstract ( 1066 ) PDF (KB) ( 4 )

Effect of automatic urine separation technology on collection of high phosphorus concentration urine and phosphorus recovery was investigated. The influence of urine purity on phosphorus recovery in a reactor was studied. The results indicated that the extending delay time resulted in decrease of urine purity whereas raising urinary amount resulted in increase of urine purity. Rate of phosphorus recovery in urine exceeded 96% under the condition of urine purity higher than 70%. The proposed urine automatic collection from urinal based on source separation of urine from flushing water effectively recovers very pure urine to meet the demand of phosphorus recovery through struvite as a fertilizer.

Anaerobic ammonium-oxidazing bacteria community compositions in different reactors and sludge morphologies
XU Yahui, LIU Miaomiao, ZHANG Shujun, ZHANG Zhennan, LI Juan, LIU Xinchun
2014, 31 (1): 67-73.  DOI: 10.7523/j.issn.2095-6134.2014.01.011
Abstract ( 1037 ) PDF (0KB) ( 4 )

In this study, all the dominant anammox bacteria were distributed over two genera, Candidatus Brocadia and Kuenenia, in four anammox reactors. It was shown that sludge morphology played an important role in the bacterial community structure of anammox bacteria. More than 36 percents of anammox bacteria in granular sludge and biofilm belonged to Candidatus Brocadia, while in flocculent sludge the domninant anammmox bacteria was Candidatus Kuenenia. Anammox bacteria in different sludge morphologies would migrate in the same reactor, but the dominant species remained.

Simulation of the effects of physical structures of riparian buffers on dispersion of traffic pollutants in urban areas of Beijing
WU Fangfang, ZHANG Na, CHEN Xiaoyan
2014, 31 (1): 74-84.  DOI: 10.7523/j.issn.2095-6134.2014.01.012
Abstract ( 1177 ) PDF (KB) ( 5 )

This study explores the effects of physical structures of riparian buffers (RBs) on the dispersion of traffic pollutants in north moat of Beijing. The results show that the RBs with different physical structures correspond to different distributions of ground concentrations of traffic pollutants (ρ) and different landing locations with the maximum concentration (xρmax) in different seasons. Specifically, the horizontal distance between RB and line source has the strongest effect on xρmax, and the vertical distance between RB and line source has also effects on both ρ and xρmax.

Evaluation of agricultural fertilizing-security based on hierarchical fuzzy recognition model
XIAO Jiujin, LU Changtai, MA Hongxing, ZHANG Jian, LI Xudong
2014, 31 (1): 85-91.  DOI: 10.7523/j.issn.2095-6134.2014.01.013
Abstract ( 1105 ) PDF (KB) ( 6 )

In order to evaluate the agricultural fertilizing-security, 9 indicators are selected,five-grade assessment standard is adopted, and index weights are established by analytical hierarchy process to build up an agricultural fertilizing-security evaluation model. By taking Pingchang county in northeastern Sichuan province as an example, the evaluation results show that the status of farmland health was improved from 2006 to 2011 in the study area and that the status will be better in the period from 2015 to 2020. The comparison shows that the evaluation results using this model are in agreement with the actual situation in the study area.

An efficient Union algorithm for large vector data
WANG Qinggang, YANG Chongjun, TIAN Shengjun, WANG Feng
2014, 31 (1): 92-97.  DOI: 10.7523/j.issn.2095-6134.2014.01.014
Abstract ( 1160 ) PDF (KB) ( 4 )

We designed an efficient union algorithm for large vector data. Firstly, we studied the union function between two or more layers, analyzed characteristics of attribute data and geometry data, and designed union algorithms for attribute data and geometry data, respectively. Secondly, we built a quad-tree index for the features of input layers. Finally, we used multithread to run the efficient union algorithm. A performance test was executed using three different vector data layers. The results show that the performance of the union function based on this algorithm is more efficient than the one in ESRI's ArcGIS10.0.

Structure and composition characteristics of deformed high-rank coals in the south of Qinshui basin and their influence on CBM adsorption/desorption
ZHANG Wenjing, JU Yiwen, KONG Xiangwen, HOU Quanlin, WEI Mingming, LI Xiaoshi, YU Liye
2014, 31 (1): 98-107.  DOI: 10.7523/j.issn.2095-6134.2014.01.015
Abstract ( 1011 ) PDF (KB) ( 3 )

Based on maceral determination, Ro test, ultimate-proximate analysis, LND, TEM, and adsorption/desorption test, composition and adsorption/desorption characteristics of deformed high-rank coals in the south of Qinshui basin were systematically studied. Results show that, 1) macro-and micro-pore fractures of high-rank coals change with the deformation degree; 2) chemical compositions of deformed high-rank coals show remarkably differences; and 3) the adsorption/desorption of deformed high-rank coals shows intimate relations with the physical and chemical compositions.

Pore structure and gas migration characterization of tight sandstone in Kuqa depression of Tarim basin
FAN Junjia, ZHOU Haimin, LIU Shaobo
2014, 31 (1): 108-116.  DOI: 10.7523/j.issn.2095-6134.2014.01.016
Abstract ( 1055 ) PDF (KB) ( 5 )

This study focuses on the pore structure and gas migration in tight sandstone reservoir in Kuqa depression of Tarim basin, based on microscopic observation and laboratory experiments. Results indicate that main pore types of tight sandstone in the study area are disslolved pores and slot pores, and the pore-throat radiuses are about 0.1 μm; there is no obvious correlation between permeability and porosity; gas migration in tight sandstone requires a certain starting pressure gradient; and the process of gas migration and accumulation in tight sandstone can be divided into the following three stages: accumulation of gas bubbles, formation of continuous state gas, and migration of the continuous state gas through pore system.

A QoS control method based on 3G network video transmission
CHENG Zhenyu, ZHANG Can, HE Zhitao, SUN Heng
2014, 31 (1): 117-123.  DOI: 10.7523/j.issn.2095-6134.2014.01.017
Abstract ( 1610 ) PDF (KB) ( 5 )

In this paper, an application-layer QoS(quality of service) control method for real-time video transmission based on 3G network is proposed. This method calculates packet loss rate using a linear prediction algorithm, and it introduces a self-designed SILD(strict increase loose decrease) congestion control algorithm to adjust the transmission bit rate of video streams. Experimental results show that the performance parameters, such as transmission delay and jitter, meet the industrial standard requirements and that the utilization of network bandwidth is improved. Therefore, the proposed QoS control method is suitable for real-time video transmission over 3G network and has good practicality and feasibility.

An XBRL dimensional data parsing algorithm based on the Map/Reduce parallel programming model
ZHU Jianpeng, WANG Ying, YANG Cheng
2014, 31 (1): 124-129.  DOI: 10.7523/j.issn.2095-6134.2014.01.018
Abstract ( 1480 ) PDF (KB) ( 5 )

This article intends to study mass semi-structured data processing technology from XBRL dimensional data processing perspective. A new XBRL dimensional data parsing algorithm is proposed based on the Map/Reduce parallel programming model and StAX stream parsing technique. The algorithm specifically targets the analysis of complex data reference relationships among XML files in the XBRL financial report. In order to parse complex XBRL dimensional data, the algorithm uses a single XBRL financial report as the minimum processing unit. First, the data are extracted from the dimensional fact items, and then the business semantic data are processed. In experimental tests, the proposed algorithm presents an obvious advantage in large-scale XBRL data processing.

Design and realization of an efficient light-weighted file system for wireless sensor networks
ZHU Shikun, LI Dong, HUANG Kui, ZHANG Baoxian
2014, 31 (1): 130-134.  DOI: 10.7523/j.issn.2095-6134.2014.01.019
Abstract ( 1005 ) PDF (0KB) ( 4 )

Sensor nodes store sensor data, system configuration data, and other information in their local storages. A file system can organize all such information in a document form and provide users with convenient operation interfaces. We design and realize a light-weighted file system for wireless sensor networks(WSNs), which achieves O(1) time complexity of file access,small runtime RAM space (<150 byte), and shortened file accessing time, and provides rich functions as compared with existing file systems for WSNs.

Brief Report
Effects of diameter and N-doping on oxygen molecule transportation through a nanotube
GE Zhenpeng, LI Xiaoyi
2014, 31 (1): 135-138.  DOI: 10.7523/j.issn.2095-6134.2014.01.020
Abstract ( 1576 ) PDF (KB) ( 2 )

We investigate how to control the net flux of oxygen molecule transportation through a carbon nanotube (CNT). We find that the net flux of oxygen molecules in a nanotube increases linearly when the diameter of the nanotube becomes big and that an N-doped nanotube has a bigger net flux of oxygen molecules than a pure carbon nanotube.

An admission control algorithm based on mobility and service in femtocell networks
PAN Jun, ZHANG Wenyi
2014, 31 (1): 139-144.  DOI: 10.7523/j.issn.2095-6134.2014.01.021
Abstract ( 1057 ) PDF (KB) ( 3 )

This paper addresses the case of hierarchical cellular network environment where both macrocell and femtocell are deployed to improve network capacity. The accepted service access to the femtocell is classified into four categories based on the timing relationship between its packet arrival/departure and mobility. An analytical framework is developed for admission control based on partially observable Markov decision process. The admission control decision scheme takes into account both bandwidth resource occupancy time and signaling cost. Simulation experiments corroborate the effectiveness of the developed algorithm.