Journal of University of Chinese Academy of Sciences

Charge asymmetry in B→K₂^*(1430)ω and its implications in B⁰→a₂(1320)^-π⁺ and a₂(1320)^-ρ⁺

YANG De-Shan, YANG Shao-Kai

2012, 29 (4): 433-438. DOI: 10.7523/j.issn.2095-6134.2012.4.001

The large charge asymmetry in B→K₂^*(1430)ω observed by the BaBar collaboration is hard to be explained within the framework of QCD factorization. We show that the enhanced tensor meson emission may cause such difficulties in the QCD factorization. We focus on the longitudinal part of the decay amplitude for B→K₂^*(1430)ω. We extract the tensor emission contribution from the experimental data and apply them to the Cabibbo favored B decays B⁰→a₂^*-π⁺(ρ⁺) by using the SU(3) flavor symmetry minimally. The predicted branching ratios of these decays are much greater than those obtained by the QCD factorization. Our results will be examined by future experimental measurements at the KEK-SuperB and LHCb.

Relativistic treatment for energy levels and oscillator strength of the lithium atom

WANG Ze, QU Yi-Zhi, HU Xiao-Li

2012, 29 (4): 439-448. DOI: 10.7523/j.issn.2095-6134.2012.4.002

Abstract ( 1135 ) PDF (KB) ( 6 )

Relativistic multichannel theory is used to calculate eigen quantum defects of 1s²ns ²S, 1s²np ²P, 1s²nd ²D, and 1s²nf ²F of lithium, and then the quantum defect functions are fitted. Ionization potentials and quantum defects of 1s²np ²P(n=7~60) are obtained, and the results are in good agreement with the latest experiment. Using the relativistic configuration interaction method, the dipole transition oscillator strength of 1s²2s→1s²np_1/2 are also calculated, and the calculations show that inclusion of one- and two-electron excitation configurations will significantly improve the results.

Expression analysis of PaMT from Phytolacca Americana

WANG Xiao, ZHAO Hui-Jun, LIU Hui-Min, CHAI Tuan-Yao

2012, 29 (4): 449-454. DOI: 10.7523/j.issn.2095-6134.2012.4.003

Abstract ( 1225 ) PDF (KB) ( 6 )

A full-length cDNA of metallothionein, designated PaMT, was cloned from SSH libraries. PaMT consists of 141 bp that code 46 amino acids. Classic structure (cxc) of metallothionein and the phylogenetic tree analysis show that PaMT belongs to metallothionein family. PaMT is preferentially expressed in root and its expression is strongly up-regulated by heavy metal stress. PaMT-NusA fusion protein expressed in Coli BL21 plays a role in the tolerance to heavy metal toxicity.

Application of GIS to analysis of the ecological sensitivity of mountain cities: a case study of Shiyan city

LIU Ai-Hua, XIE Zheng-Guan, WANG Jia-Zhuo

2012, 29 (4): 455-460. DOI: 10.7523/j.issn.2095-6134.2012.4.004

Abstract ( 1069 ) PDF (KB) ( 4 )

With GIS technology and a factor-weighted superposition method, eco-sensitivity in the Shiyan planning area is analyzed based on five selected factors, including land use pattern, elevation, gradient, NDVI, and distance between the river basin and the Danjiangkou reservoir. In the evaluation, the whole area is divided into 4 zones. Advice for each of the zones is provided for environmental protection and urban-rural construction.

Economic spatial structure evolution of Guangdong province based on generalized principal component analysis

YU Shu-Min, XIE Zheng-Guan

2012, 29 (4): 461-468. DOI: 10.7523/j.issn.2095-6134.2012.4.005

Abstract ( 1185 ) PDF (KB) ( 2 )

We studied the economic spatial structure evolution process of Guangdong province from 1988 to 2008 based on urban scale using the generalized principal component analysis (GPCA) method. The results show that under the uneven regional development policy the urban economy gap expanded continuously and industry was restructured. From 1988 to 1998, two core cities, Guangzhou and Shenzhen, were strengthened in position. From 1999 to 2008, two sub-core cities, Dongguan and Foshan, emerged gradually. Thus the spatial structure evolved from dual-core status to multi-core status.

Analysis of dynamic evolution of energy-related CO₂ emission in Shandong province

WANG Chang-Jian, ZHANG Li, WANG Qiang, QIAO Ying

2012, 29 (4): 469-475. DOI: 10.7523/j.issn.2095-6134.2012.4.006

Abstract ( 1111 ) PDF (KB) ( 3 )

Main factors responsible for the carbon emissions (CE) in Shandong were analyzed using the LMDI method. We found that CE and CE per capita increased year by year but the CE intensity decreased continuously. Coal consumption from the secondary industry and economic activity was the main driving force. Energy consumption intensity influenced CE and it was affected by the industrial structure and the energy consumption of different industrial sectors. The change in structure of energy consumption has relatively small impact, but it has displayed positive effect on the mitigation of CE.

Strong ground motion simulation of the 1970 M_S 7.7 Tonghai earthquake, Yunnan, China

TAN Li-Zhong, MENG Ling-Yuan, SHI Bao-Ping

2012, 29 (4): 476-484. DOI: 10.7523/j.issn.2095-6134.2012.4.007

Abstract ( 1004 ) PDF (KB) ( 4 )

Using a composite source model, we simulate the strong ground motion from the 1970 Tonghai earthquake (M_S 7.7). Due to the lack of strong ground motion recordings and for verifying the reliability of simulated results,a finite fault model, developed based on the stochastic theory with the same input source parameters including fault slip distribution pattern and size, is additionally used to generate synthetic strong motion seismograms for comparison purpose. The acceleration time histories at four selected sites or cities, simulated by the two models, show good agreements in the amplitude, waveform, frequency content, and time duration within the 0.5-10 Hz frequency domain.

Comparison of tectono-thermal evolution between Bachu uplift and Tabei uplift in Tarim basin

YU Jing-Bo, ZHANG Jian, LI Pei-Hai

2012, 29 (4): 485-492. DOI: 10.7523/j.issn.2095-6134.2012.4.008

Abstract ( 909 ) PDF (KB) ( 5 )

Bachu uplift and Tabei uplift are located in analogous tectonic positions. We have recovered burial histories, tectonic subsidence histories, and thermal histories of the two regions. The results indicate that there are many unfavorable conditions for Bachu area to accumulate hydrocarbons, such as high basal heat flow, early hydrocarbon generation, late paleouplift development, and severe activity of faults.

Low-complexity joint source-channel coding and decoding approach based on space trellis

HUO Yue-Heng, ZHANG Can, GAO Shao-Shuai

2012, 29 (4): 493-500. DOI: 10.7523/j.issn.2095-6134.2012.4.009

Abstract ( 960 ) PDF (KB) ( 4 )

We have optimized weight value of space trellis and proposed a low-complexity joint source-channel coding and decoding approach based on space trellis. Simulation results show that, compared to the existing methods, the proposed approach reduces computation complexity and improves decoding performance. The approach can be applied to joint en/decoding of streaming media in resource-constrained space communications.

A novel wide-range digital duty-cycle-correction circuit with fixed rising edges

CHEN Zhu-Jia, YANG Hai-Gang

2012, 29 (4): 501-506. DOI: 10.7523/j.issn.2095-6134.2012.4.010

Abstract ( 1106 ) PDF (KB) ( 3 )

A novel all-digital CMOS duty-cycle-correction (DCC) circuit with wide correction ranges of input duty cycle is proposed in FPGA. The proposed DCC circuit has the fixed rising edge. A successive approximation register circuit is utilized to reduce the adjusting time of the DCC. The proposed circuit is fabricated in a 0.13 μm CMOS standard technology. Measurement results show that the DCC adjusts the output duty cycle to 50%±2% for a wide input duty cycle range from 10% to 85%. The DCC could operate within a frequency range from 80 MHz to 250 MHz with the adjusting time of 6 clock cycles.

Synthetic aperture radar images target discrimination based on combined SVM and LDA

ZHAO Feng-Jun, GAO Dong-Sheng, JIA Ya-Fei

2012, 29 (4): 507-511. DOI: 10.7523/j.issn.2095-6134.2012.4.011

Abstract ( 1271 ) PDF (KB) ( 3 )

We propose a method for synthetic aperture radar images target discrimination based on the principal component analysis and an approach combining support vector machine (SVM) and linear discriminant analysis(LDA). Dimensionality of the image vector is reduced and the global features are extracted by using principal component analysis. The global features are transformed and the results are used to generate classifiers which complete target discrimination. The results show the high performance of the proposed method.

Architecture design and optimization for motion estimation with dynamic search range

CHEN Yun-Bi, GUO Li, LI Zheng-Dong, CHI Ling-Hong

2012, 29 (4): 512-517. DOI: 10.7523/j.issn.2095-6134.2012.4.012

Abstract ( 1024 ) PDF (KB) ( 3 )

A VBSME with dynamic search range is proposed to overcome the defects of the engine with fixed search range, and it reduces off-chip bandwidth, computational complexity, and power dissipation. A circularly distributed storage structure is adopted to realize the access to the dynamic search area. Besides, the time-consuming SAD computing array is divided into the balanced and adder-optimized pipelines. The implementation results show that, compared to traditional engines, the proposed engine can achieve significant improvements of the hardware and the power efficiency without much loss of throughput.

UE power saving scheduling method using DRX for video streaming in LTE

TIAN Jian-Jun, QIU Ling

2012, 29 (4): 518-523. DOI: 10.7523/j.issn.2095-6134.2012.4.013

Abstract ( 1687 ) PDF (KB) ( 3 )

A scheduling method for saving UE's power by using DRX for the video streaming is proposed in this paper. The times of starting/restarting I-Timer can be reduced while the delay requirement of a packet is guaranteed, which increases the sleeping time of a UE. Simulation results show that this method can significantly reduce the power consumption of a UE with the same packet loss rate.

Bessel field pre-treatment based on wavelet analysis

LI Qin, TAN Guan-Zheng

2012, 29 (4): 524-528. DOI: 10.7523/j.issn.2095-6134.2012.4.014

Abstract ( 976 ) PDF (KB) ( 5 )

The simulated sound field of an annular ultrasound transducer is given based on Fourier-Bessel series method. After analyzing the axial acoustic pressure, especially the near-field disturbance, wavelet multi-resolution analysis of the noise reduction is carried out for removing the near-field complex frequency components and increasing the sound pressure amplitude. The results show that the wavelet analysis technique can be used for improving the fundamental ultrasound imaging quality of Bessel field.

Network-vulnerability evaluation method based on network centrality

JIA Wei, FENG Deng-Guo, LIAN Yi-Feng

2012, 29 (4): 529-535. DOI: 10.7523/j.issn.2095-6134.2012.4.015

Abstract ( 1269 ) PDF (KB) ( 4 )

We propose a method based on network centrality to evaluate the vulnerabilities of computer networks. We evaluate the attack costs based on CVSS and analyze the minimum attack cost routes by using the quantitative results. Then, we present a new network centrality method which combines betweenness with degree-theory to analyze the importance of the nodes in attack graph. The method helps us to find the key vulnerabilities which have great effect on network security and to enhance the network security.

A quick network constructing method based on adaptive grouping

WANG Jia-Bin, LIAN Yi-Feng, CHEN Kai

2012, 29 (4): 536-542. DOI: 10.7523/j.issn.2095-6134.2012.4.016

Abstract ( 1013 ) PDF (KB) ( 2 )

Direct deployment and computer cloning are the two existing network constructing methods, which have low efficiency and flexibility. We propose a quick network constructing method using adaptive grouping policy based on the distribution characteristics of deployment time. The method reduces repeated deployment time and improves efficiency. An adaptive grouping-based quick network constructing prototype system is implemented and the algorithm is verified.

Physical-based hair modeling method

SONG Jin-Lian, WU En-Hua

2012, 29 (4): 543-548. DOI: 10.7523/j.issn.2095-6134.2012.4.017

Abstract ( 1042 ) PDF (KB) ( 4 )

A new physical-based method is proposed to model hair with high efficiency and simple human interaction. Also, an improved speed-verlet dynamic simulation method is presented.

Hardness of the edge-disjoint Min-Min problem in undirected graphs

GUO Long-Kun, SHEN Hong

2012, 29 (4): 549-554. DOI: 10.7523/j.issn.2095-6134.2012.4.018

Abstract ( 1101 ) PDF (KB) ( 4 )

We show incorrectness of the NP-completeness proof of Bhatia et al. for the edge-disjoint Min-Min problem in undirected graphs, by giving a counter example that is an unsatisfiable 3SAT instance but was classified satisfiable in the proof of Bhatia et al. We then give a proof of NP-completeness of the edge-disjoint Min-Min problem in undirected graphs, based on a reduction from the MAX-2SAT problem.

A network-independent transmission optimization mechanism for P2P streaming over wireless Ad Hoc networks

YE Hao, XUE Kai-Ping, HONG Pei-Lin, LU Han-Cheng

2012, 29 (4): 555-563. DOI: 10.7523/j.issn.2095-6134.2012.4.019

Abstract ( 1233 ) PDF (KB) ( 3 )

Based on the features of P2P streaming model over wireless Ad Hoc networks, we propose a transmission optimization mechanism which works at the P2P data topology level and is independent of the underlying networks. According to importance of video slices and network conditions, peers adjust transport layer parameters adaptively to reduce transmission delay for important slices. Experiment results show the effectiveness on improvement of quality of service and reduction of control overhead.

Expected value of k-error linear complexity of periodic sequences

WU Cheng-Wen, YUE Qin

2012, 29 (4): 564-570. DOI: 10.7523/j.issn.2095-6134.2012.4.020

Abstract ( 948 ) PDF (KB) ( 3 )

The k-error linear complexity of a periodic sequence over a finite field F_q is defined to be the smallest linear complexity that can be obtained by changing k or fewer bits per period. We explicitly give the expected value of k-error linear complexity of pⁿ-periodic sequences over F_q, where p is an odd prime, q is a prime primitive root modulo p², and 1≤k≤(p－1)/2.

Mechanistic study on hydrogenation of electron-rich substrates with electron-deficient Rh-BINAP catalyst

HUANG Bi-Yu, WU Hai-Chen, YANG Jing-Kui

2012, 29 (4): 571-575. DOI: 10.7523/j.issn.2095-6134.2012.4.021

Abstract ( 1423 ) PDF (KB) ( 4 )

Four electron-rich α-acetamidocinnamic acid derivatives were prepared and used as substrates in the asymmetric hydrogenation catalyzed by electron-deficient Rh-3,5-CF₃-(R)-BINAP. Influence of the electronic properties of substituted groups in the substrates and their steric hindrance on the enantioselectivity of the product were discussed.

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