Journal of University of Chinese Academy of Sciences

The boundedness of the fractional truncation operators

CUI Xiaona, YAN Dunyan

2015, 32 (4): 433-436. DOI: 10.7523/j.issn.2095-6134.2015.04.001

In this paper, we consider the boundedness of two kinds of the truncated operators from L^p to L^r. For any fixed p we can obtain a variational interval of r, and we characterize the relationship between the interval and the fractional operators. We also give an estimate of the upper bound of the norm of the operator.

L^p-Bounds of a class of mean operators on product spaces

CHEN Guangzhou, WEI Mingquan, YAN Dunyan

2015, 32 (4): 437-440. DOI: 10.7523/j.issn.2095-6134.2015.04.002

Abstract ( 683 ) PDF (KB) ( 5 )

We characterize a sufficient and necessary condition which ensures that the operator
H_φf(x)=...f(x₁ t₁,…,x_n t_nφ(t₁,…,t_n)dt₁…dt_n
is bounded on L^p(Gⁿ) with 1≤p≤∞. The condition deeply depends on the nonnegative function φ defined on [0,1]×…×[0,1]. Furthermore, the corresponding operator norms are worked out.

On a parametric Hilbert-type integral inequality and its applications

LIU Qiong

2015, 32 (4): 441-445. DOI: 10.7523/j.issn.2095-6134.2015.04.003

Abstract ( 593 ) PDF (KB) ( 3 )

By introducing some parameters and by using the way of weight function and the techniques of real analysis and Laplace's integral transform, a parametric Hilbert-type integral inequality and its equivalent form are given, and their constant factors are proved to be the best values. As applications, some meaningful results are obtained by selecting the special values for the parameters.

Portfolio selection based on asset selection and the empirical study in Chinese stock market

XU Yang, WANG Yan, ZHAO Zilong

2015, 32 (4): 446-452. DOI: 10.7523/j.issn.2095-6134.2015.04.004

Abstract ( 593 ) PDF (KB) ( 4 )

Lars-Lasso regression algorithm is a popular statistical element method. For the investment markets with large amount of assets, we apply the Lars-Lasso method to the asset selection, which is the first step of portfolio selection, and then use the portfolio optimization model. The utility of this approach is illustrated by empirical studies on Chinese stock market, and it is verified to have better performance than the market index.

Dynamic prediction method of atomic clock frequency based on UTCr

YAN Min, QU Lili, DONG Shaowu, SONG Huijie

2015, 32 (4): 453-458. DOI: 10.7523/j.issn.2095-6134.2015.04.005

Abstract ( 653 ) PDF (KB) ( 5 )

The traditional method of atomic clock frequency prediction is based on the clock frequency, which is published by BIPM monthly. It has the characteristic of hysteresis. Because of the influence of different kinds of noise on the atomic clocks, it is difficult to predict accurately atomic clock frequency. A dynamic prediction model for atomic clock frequency is proposed based on a rapid Coordinated Universal Time (UTCr) published by BIPM. The new method and the traditional method are applied to calculate the atomic time scales with the real data of NICT, NTSC, and NIM. The time scales calculated by the different methods, are compared with UTC-UTC(k), respectively. The results show that the new method is superior the traditional one. The new method greatly improves the quasi-real time of frequency prediction, provides more quasi-real time and reliable reference for frequency steering, and enhanes stability and accuracy of UTC(k).

Coordination behavior between 2,6-bis(phenylethynyl)-4-isobutoxy-pyridine oligomers and Ag(I)

LI Qiaolian, HUANG Fu, SHANG Jie, HE Yujian

2015, 32 (4): 459-467. DOI: 10.7523/j.issn.2095-6134.2015.04.006

Abstract ( 682 ) PDF (KB) ( 3 )

A series of 2,6-bis(phenylethynyl)-4-isobutoxy-pyridine oligomers, including monomer, dimer, and trimer, were prepared and characterized with ¹H and ¹³C NMR spectroscopies and HR-ESI mass spectrometries, respectively. A combination of ¹H-NMR titration experiments, Job's Plot experiments, and HR-ESI mass spectrometries confirmed that the oligomers were able to form triple-stranded helical structures in the presence of silver ions in solution and indicated that the coordination ability of the oligomers were significantly enhanced due to isobutoxy group.

Direct analysis of platinum loading on electrode

XUE Qiong, ZHANG Zhikun, HE Yujian, YANG Jingkui, YANG Zhiyong

2015, 32 (4): 468-475. DOI: 10.7523/j.issn.2095-6134.2015.04.007

Abstract ( 811 ) PDF (KB) ( 3 )

A simple, easy-handling, and ultrasensitive quantitative analysis of platinum (Pt) component based on ultraviolet-visible (UV-Vis) spectroscopy is carried out to determine the real Pt loading on glass-carbon electrode. On the basis of the acquired data, the electrochemical active surface area (ECSA) and the peak current (Ip) of methanol electrochemical oxidation as the indicative parameters of the model catalyst (commercial platinum/carbon (Pt/C)) are calculated precisely. For the comparison purpose, the ECSA and Ip are also specified by the theoretical Pt loading calculated based on the Pt content of bulk materials and the ink coating on electrode. The results show that the relative standard deviations of both the ECSA and Ip averaged by real Pt loading decrease significantly, indicating that the data calibrated by real Pt content reflect the intrinsical properties of the commercial Pt/C. Our research may help to increase the accuracy of Pt-containing catalyst evaluation, make the data in different reports comparable, and improve performance of fuel cell catalysts.

Artemisinin biosynthesis of Artemisia annua L. promoted by brassinosteroid

CHI Jianting, SHEN Yalin, SHU Weiheng, WANG Hong

2015, 32 (4): 476-481. DOI: 10.7523/j.issn.2095-6134.2015.04.008

Abstract ( 666 ) PDF (KB) ( 2 )

As a plant growth regulator, brassinosteroid is able to activate the expression of the genes in their promoter sequences containing E-box (CANNTG) cis-element. Since the key enzyme genes of artemisinin biosynthesis pathway, including ADS (amorpha-4,11-diene synthase), DBR2 (artemisinic aldehyde Δ11(13) reductase), and CYP71AV1 (cytochrome P450 monooxygenase), all contain this element, the effect of brassinosteroid on artemisinin biosynthesis is investigated. Our results show that 80 μmol/L of brassinosteroid is the optimal concentration for foliar application of Artemisia annua L.; the artemisinin content increases by more than 100% compared to that of the control after 80 μmol/L brassinosteroid treatment for 4 days; and the expressions of artemisinin biosynthesis-related genes ADS, CYP71AV1, and DBR2 are all up-regulated after treatment. The above results indicate that brassinosteroid promotes the biosynthesis of artemisinin by up-regulating the expression of the key genes involved in artemisinin biosynthesis, which could be used as a possible way to increase artemisinin production of medicinal plant A. annua.

A new method for screening of β₂-agonists by micellar electrokinetic chromatography

MENG Xiangying, SUO Xingmei, DING Yongsheng

2015, 32 (4): 482-489. DOI: 10.7523/j.issn.2095-6134.2015.04.009

Abstract ( 736 ) PDF (KB) ( 5 )

A method for the determination of five β₂-agonists in pig feed, liver, meat, and urine samples by micellar electrokinetic chromatography was developed. The separation and detection conditions were optimized in terms of SDS concentration, running buffer pH and concentration, capillary temperature. Under the optimized conditions (15 mmol/L borate, pH=10, 15 mmol/L SDS, and 25 ℃), all five analytes in the spiking samples were separated and identified within 18 min. Good linearity (R²>0.999) was obtained for the analytes in the range of 0.1-40 μg/mL with the limit of detection (S/N ≥ 3) in the range of 0.05-0.08 μg/mL. The satisfactory recoveries of cimaterol, ractopamine and clenbuterol were obtained in the range of 93.1%-95.8%, whereas the recoveries of salbutamol and terbutaline were at 52.3% and 69.4%, respectively. The relative standard deviations of peak area and migration time of the analytes were less than 4.86% and 1.25%, respectively. The method was successfully applied to monitor the presence of the selected β₂-agonists in pig feed, liver, meat and urine samples.

Characteristics of organic and element carbon in fine particles in Lanzhou

LI Yinghong, DUAN Jingchun, ZHENG Naijia, TAN Jihua, RAO Zhiguo, MA Yongliang, HE Kebin

2015, 32 (4): 490-497. DOI: 10.7523/j.issn.2095-6134.2015.04.010

Abstract ( 692 ) PDF (KB) ( 5 )

A total of 60 PM_2.5 samples were collected during winter and summer seasons in Lanzhou city. OC and EC were measured by the thermal/optical method using DRI-2001A. The results indicated that carbonaceous aerosol in winter was significantly higher than that in summer. The average concentrations of OC and EC were (35.39±13.88) μg/m³ and (13.80±5.41) μg/m³ in winter and (9.74±3.30) μg/m³ and (4.44±2.00) μg/m³ in summer, respectively. The correlation between OC and EC was 0.91 in winter and 0.76 in summer, which revealed that OC and EC had similar sources. The concentrations of SOC were (8.48±6.10)μg/m³ and (3.07±2.20)μg/m³ in winter and summer, and they were about (22.46±11.93)% and (31.29 + 18.51)% of OC in PM_2.5, respectively, which manifested that OC was mainly from primary sources and the contribution of secondary transformation was higher in summer than in winter. Analysis on the eight fractions of carbonaceous aerosol within the different temperature ranges showed that biomass burning had a high contribution for carbonaceous aerosol in PM_2.5 in winter, but vehicle emissions might be the major source in summer.

Effects of ecological restoration of riparian zone on water quality of Yongding river in Beijing

WANG Ziqi, ZHANG Na, SUN Wei, WANG Xianxian

2015, 32 (4): 498-505. DOI: 10.7523/j.issn.2095-6134.2015.04.011

Abstract ( 636 ) PDF (KB) ( 15 )

The ecological effects of restoration of flood lands and buffers from Mencheng lake to Lianshi lake along Yongding river in Beijing were discussed. From July to October in 2013, water samples were periodically collected at the 8 selected sites along the west bank, and the concentrations of dissolved oxygen(DO), nitrate nitrogen(NO₃^-—N ), ammonia nitrogen (NH₄⁺—N), and total phosphorus(TP) were measured and analyzed. The results showed that there were obvious seasonal variations in the concentrations of these nutrients and DO in Yongding river. For most of the sites, water quality could not meet the requirements for the surface water standard class IV. The NH₄⁺—N concentration was low where the amount of hydrophytes was relatively large. During the growing season, higher coverage of hydrophytes led to higher DO and NO₃^-—N concentrations and lower TP concentration, while at the end of the growing period, much small contributions to the higher TP and lower DO concentrations. The convex river bank could enhance the DO and NO₃^-—N concentrations and reduce the NH₄⁺—N concentration. In short, changes in the structure characteristics of riparian zone such as bank material, abundance of hydrophytes, and curvilinearity of banks had great effects on water quality in Yongding river.

Construction of 3D visualization model of groundwater system under multiple constraints based on GMS

LIU Lihua, ZHANG Shuqing

2015, 32 (4): 506-511. DOI: 10.7523/j.issn.2095-6134.2015.04.012

Abstract ( 712 ) PDF (KB) ( 3 )

In recent years, the excessive exploitation of groundwater resources caused a series of ecological and environmental problems, such as land subsidence, vegetation degradation, and soil salinization. The 3D groundwater aquifer model can intuitively show the spatial distribution of aquifer and provide decision and technical supports to water resource evaluation, prediction, and reasonable exploitation. By using GMS software, a 3D model of groundwater aquifers in some areas of Suzhou-Wuxi-Changzhou region is constructed based on the borehole data. The model is modified by partitioning the study area and by introducing virtual borehole and geological cross-section in the borehole sparse and stratigraphic pinch-out areas for enhancing the model precision. The results show that the accuracy has been significantly improved, and the 3D model revealed is basically consistent with the survey data. This model will be useful for guiding utilization of groundwater, optimization of planning structure, and development of water-saving irrigation measures.

Identification and biological property study of an enterohemorrhagic E.coli O157 phage isolated from sewage treatment plant aeration tank

YI Xin, LIU Xinchun, HUANG Jing, LIU Honghui, LI Juan

2015, 32 (4): 512-519. DOI: 10.7523/j.issn.2095-6134.2015.04.013

Abstract ( 650 ) PDF (KB) ( 3 )

The purpose of this work was to isolate the lytic phages of Escherichia coli O157 from an aeration tank sample and to investigate the biological characteristics of the isolated phage. The titer of purified bactiriophage was 8.7×10¹¹pfu/mL. The electron microscope showed the phage had a hexahedron cubic-symmetric head with 70 nm in diameter and a short tail (about 10 nm in length and about 10 nm in width). The restriction enzyme fragments suggested that it was dsDNA. The optimal MOI (multiplicity of infection) value was 0.01. Phage PO157-Z showed wide range of acid-alkali tolerance. In addition, the curves of bacteria lysed by phage showed that PO157-Z had a high lytic activity on E.coli O157. Thus, PO157-Z is a strain of lytic phage against enterohemorrhagic E.coli O157 and belongs to tailed families Podoviridae with dsDNA. These characteristics of phage PO157-Z would be useful in various applications as a novel biocontrol agent against E.coli O157.

Regional eco-efficiency evaluation of China based on PCA-DEA model

WANG Min, ZHANG Xiaoping

2015, 32 (4): 520-527. DOI: 10.7523/j.issn.2095-6134.2015.04.014

Abstract ( 838 ) PDF (KB) ( 3 )

In order to evaluate eco-efficiency of every province in China from 2004 to 2012, PCA-DEA model was applied. We found that the average of Chinese relative eco-efficiency was low and had no significant change mainly due to technical inefficiency, but the scale efficiency had shifted to technical efficiency since 2011. Although the eco-efficiency disparities between different provinces were obvious, the disparities had decreasing tendency. In contrast, regional disparity of eco-efficiency in the east region tends to expand. Accordingly, policy incentives are suggested to improve the regional eco-efficiency.

Analysis of change process and influence factors of water resource utilization in megalopolis of arid area: a case study of Urumqi city

ZHANG Yufang, YANG Degang, TANG Hong, LIU Yaxuan

2015, 32 (4): 528-535. DOI: 10.7523/j.issn.2095-6134.2015.04.015

Abstract ( 580 ) PDF (KB) ( 2 )

Urumqi was selected as the object for this study. Through constructing an all-factor decomposition model, Logarithmic mean Divisia index (LMDI) decomposition method was used to conduct decomposition analyses on the factors that caused the change process of water resource utilization in Urumqi from 1995 to 2012. The results indicated that economy development level and water use intensity, and the effects of industrial water use structures, economy level, and water use intensity were the determinant factors that influenced the water use consumption and efficiency, respectively. The adjustment of industrial structures and the upgrading of industrial technologies caused certain inhibitory effects on the total water consumption, but these effects were not strong. The amount of water supply per capital had inhibitory effects in certain extent on water resource utilization efficiency.

A direct location method for air-borne SAR image without ground control points

PAN Zhigang, PAN Zhuo, CAO Ge

2015, 32 (4): 536-541. DOI: 10.7523/j.issn.2095-6134.2015.04.016

Abstract ( 738 ) PDF (KB) ( 4 )

A location method without reference points for air-borne SAR image is proposed. This method exploits related parameters in auxiliary data of SAR image, based on geographic coordinates of a point and the correlation of range-azimuth between this point to another point in the geodetic coordinate system, convert the problem of SAR image location to solution of geodetic problem. The effects on location precision caused by system error are studied. The experimental results on real-world SAR image validate effectiveness of the proposed method.

An interferogram simulation method for multi-channel InSAR

YUAN Zhihui, CHEN Lifu, FAN Shaosheng, GAO Canguan

2015, 32 (4): 542-548. DOI: 10.7523/j.issn.2095-6134.2015.04.017

Abstract ( 657 ) PDF (KB) ( 2 )

In order to simplify the procedure of multi-channel InSAR interferogram simulation and to provide simulated data with adjustable parameters for studies of multi-channel InSAR technology, we propose a multi-channel InSAR interferogram simulation method. The method uses the available DEM and system parameters to calculate the real interferometric phase for each channel, and calculates the coherence caused by various kinds of noise. Then the method utilizes acceptance-rejection method to generate the corresponding phase noise, and adds it to the real interferometric phase. So the needed multi-channel InSAR interferograms are obtained. Analysis and simulation results indicate that the approach is simple and convenient. The approach considers the interferometric phase noise's probability density function strictly, and it provides suitable simulation data sets for the performance comparison and quantitative analysis of various kinds of multi-channel InSAR technique.

A modified double-buffering algorithm oriented to iOS and its application

SHI Rui, YANG Chongjun, ZHANG Jianbing, WANG Feng

2015, 32 (4): 549-555. DOI: 10.7523/j.issn.2095-6134.2015.04.018

Abstract ( 557 ) PDF (KB) ( 2 )

In order to improve the rendering efficiency of iOS-oriented (iPhone operating system) vector map, a method for determining the simplification limit for small-screen mobile devices is proposed through the thorough analysis of the simplification algorithm of vector data. On the basis of Douglas-Peucker algorithm we use this method to quantitatively calculate simplification limit, considering the factors of screen pixels and time tolerance. In addition, a modified algorithm is proposed for improving the efficiency of double buffering skill, on the basis of the study on rendering procedure and double buffering skill with Quartz 2D. The experimental results show that the modified alg orithm is more efficient than the traditional one.

Moving jammer suppression with robust blind adaptive algorithms in GPS receiver

WANG Lei, HAN Yuxin

2015, 32 (4): 556-561. DOI: 10.7523/j.issn.2095-6134.2015.04.019

Abstract ( 575 ) PDF (KB) ( 2 )

The problem of providing robustness to the conventional narrow-band uniform linear array configuration so as to handle moving and cochannel jammers in GPS receiver is addressed here. This robustness is obtained via the use of derivative constraints in jammer directions. We develop the robust power inversion (PI) algorithm, the loading robust PI algorithm, and the robust eigenvector projection (EP) algorithm. These three algorithms are characterized by the fact that there is no need to know the directions of the GPS signals and jammers. Simulation results show that the algorithms proposed here are suitable for dealing with moving or cochannel jammers.

Low-power strategy based on delayed awakening 3G network for smartphone

CHEN Bo, LI Xi, ZHOU Xuehai, XI Jing, ZHU Zongwei

2015, 32 (4): 562-570. DOI: 10.7523/j.issn.2095-6134.2015.04.020

Abstract ( 663 ) PDF (KB) ( 4 )

The burst data transfer will lead to 3G migration from the low-power state to high-power state, and frequent switching exacerbates the energy consumption. We analyze 3G network communication behavior and give a low-power strategy based on delayed awakening 3G network for smartphone. The strategy classifies packages according to the delay-sensitivity, and delays sending packet for different intervals so as to reduce the energy consumption. Simulation results show that the proposed mechanism effectively reduces the power consumption of the system and has the strong feasibility.

Palmprint matching algorithm based on minutia feature points and GPU application

WU Chunsheng, FENG Caigang, CHI Xuebin

2015, 32 (4): 571-576. DOI: 10.7523/j.issn.2095-6134.2015.04.021

Abstract ( 826 ) PDF (KB) ( 5 )

The problems of palmprint application in public security department, such as large database and poor quality of scene palmprint, are described in this paper. Firstly, the computational complexity of palmprint feature point matching algorithm is analyzed. The three-level feature point matching algorithm is presented based on the results of the analysis. Secondly, the working process of three-level feature point matching algorithm is described in detail. Finally the algorithm is transformed to the GPU parallel and the test results are given. The GPU technology is first applied to palmprint recognition in our study. The results show that the speed of palmprint feature matching increases about three times compared with others, and the speed may increase more than 15 times after using GPU technology.

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