Journal of University of Chinese Academy of Sciences

Jingjuan Zhang; Yishi Shi; Guohai Situ

2006, 23 (3): 289-296. DOI: 10.7523/j.issn.2095-6134.2006.3.001

Information hiding using optical processing system is becoming a new inter-discipline and receives increasing attention recently, because of the inherent advantages of the system, such as high speed and parallel processing. In the present paper, the major methods of optical information hiding, basing on the technique like random phase encoding and digital holography, are described and analyzed. Multiple and 3D information hiding are also introduced. Finally the difficulties and possible advances for further research are also pointed out in brief.

An Optimization Problem Arising from Variance Function Estimation

CHEN Xia, CHEN Xi-Ru

2006, 23 (3): 297-300. DOI: 10.7523/j.issn.2095-6134.2006.3.002

Abstract ( 1076 ) PDF (KB) ( 0 )

A New Proof of the Sharp Hardy Inequality to the Grushin Type Operators

LIU Hai-Feng, NIU Peng-Cheng

2006, 23 (3): 301-305. DOI: 10.7523/j.issn.2095-6134.2006.3.003

Abstract ( 1137 ) PDF (KB) ( 0 )

A generalized sharp Hardy inequality to the degenerate elliptic operators with respect to
Grushin type operators is proved by an ingeniously choosing of test functions and calculating
of the maximum value of a quadratic equation. Some interesting corollaries are also listed.

Fractal Distribution of Nucleation Site Density in Nucleate Boiling

JIA Tao, DIAO Yan-Hua

2006, 23 (3): 306-312. DOI: 10.7523/j.issn.2095-6134.2006.3.004

Abstract ( 1450 ) PDF (KB) ( 0 )

This paper reviews the factors affecting the distribution of nucleation site density in nucleate boiling and then uses fractal theory to discuss the relationship between boiling surface microstructure information and nucleation site density and study the data of nucleation site density in two boiling experiments: one is to investigate the change of nucleation site density during the course of aging process, the other is to investigate the difference of the nucleation site density on two boiling surfaces made of different materials. The result of experimental data analysis shows that the relationship between nucleation site density and minimum nucleation radius is fractal. Fractal dimensions are calculated and different fractal dimensions correspond to different boiling surfaces. Fractal dimension is a quantitative parameter describing boiling surface character.

An Experimental Investigation of Heat Transfer Performance on A Micro-Grooves Phase Change Micro-Cooling System

YAN Xiao-Hong, HU Xue-Gong, ZHAO Yao-Hua

2006, 23 (3): 313-316. DOI: 10.7523/j.issn.2095-6134.2006.3.005

Abstract ( 1475 ) PDF (KB) ( 0 )

This paper described an experimental investigation on heat transfer performance of a micro-grooves phase change micro-cooling system for heat dissipation of high power electronic apparatus. The effects of distance from the reservoir surface of cooling medium to the center of heated zone, the size of grooves and the adoption of transverse grooves were discussed. The optimal distance from the reservoir surface of cooling medium to the center of heated zone and the optimal size of micro rectangular capillary grooves were obtained.

A Visual Experimental Study on Surface Temperature Field in Stainless Steel Microtube

LIU Zhi-Gang, ZHAO Yao-Hua

2006, 23 (3): 317-322. DOI: 10.7523/j.issn.2095-6134.2006.3.006

Abstract ( 1213 ) PDF (KB) ( 0 )

To accurately measure the surface temperature field of the microtube and solve the influence of axial heat conduction along wall of the microtube on convective heat transfer in the microtube, No-contacting temperature measuring method is firstly used in the microscale experiment. An experimental test loop, which can conduct some tests about micro-heat transfer and micro-flow for gas and liquid, is established. When distilled water is used as the working fluid and flowing through the microtube, a visual experiment about the surface temperature field is conducted, that is, the surface temperature field photos of microtube with inner diameter of 168µm and outer diameter of 406µm were acquired by employing the infrared thermoviewer and specially magnifying lens for the constant Re number and different heating powers. Further, the second order derivative about the temperature along axial microtube to the length is obtained. A simple mathematic model is set up and the correlation between the axially conductive heat and inner convective heat transfer is obtained by derivation. The experimental results and the theoretical analysis show that the quantity of axial heat conduction is considerable small and may be neglected compared to the convective heat transfer in the condition of single-phase.

Investigation on the Preparation of μ-Sized PMMA Microspheres by the Dispersion Polymerization

WU Shao-Gui, LIU Bai-Ling

2006, 23 (3): 323-330. DOI: 10.7523/j.issn.2095-6134.2006.3.007

Abstract ( 2298 ) PDF (KB) ( 0 )

The micron-grade PMMA microspheres with narrow size distribution were prepared by dispersion polymerization. The mechanism of the dispersion polymerization was discussed. The factors influencing both the size and size distribution of the microspheres including initial concentrations of the initiator, monomer, stabilizer, the polarity of the medium and the reaction conditions were studied. The results indicated that the size and size distribution of microspheres both increased with initial concentrations of initiator and monomer. Increasing the amount of the stabilizer resulted in decreasing size and narrowing size distribution of microspheres. Other factors such as the polarity of medium and the reaction temperature had great influences too. By controlling these factors, the desired-size monodisperse microspheres could be obtained.

Impact of Ce-Zr-Al Mixed Oxide Modified by Potassium on Pd-Only Three-Way Catalysts

YAO Qing, TIAN Qun, CHEN Hong-De, HAN Yun

2006, 23 (3): 331-336. DOI: 10.7523/j.issn.2095-6134.2006.3.008

Abstract ( 1270 ) PDF (KB) ( 0 )

The Ce-Zr-Al mixed oxides were prepared by sol-gel method with some special procedures. Pd-K/CZA catalysts were characterized by TG-DTA, XRD, H2-TPR, O2-TPD and CO-TPD. The results showed that the activity of Pd-K/CZA catalysts with a small amount of potassium reduced, when it had been recovered with a large amount of potassium. It is shown by the calculation from CO uptake that the dispersion of Pd increased from 14.8% (K/CZA: 0 wt %) to 22.3% (K/CZA: 1.5 wt%), then decreased to 8.6%(K/CZA: 14.6 wt%). The light-off temperatures of the samples increase with increment of amount of potassium, which is due to poison of potassium that weakens SMSI of Pd-Ce. For the sample K-4 with a big amount of potassium (K/CZA: 14.6 wt%), the poison was lightened because the particle size of Pd is beneficial to the three-way reaction.

A Modified Potential Vorticity Equation for Mesoscale Systems

GAO Shou-Ting, CUI Xiao-Peng

2006, 23 (3): 337-341. DOI: 10.7523/j.issn.2095-6134.2006.3.009

Abstract ( 1324 ) PDF (KB) ( 0 )

A new set of atmospheric equations is derived in an adiabatic, and frictionless atmosphere, and the characteristics of the new equations are discussed. The new set of equations is useful in the evaluation of the potential effect of slantwise isentropic surfaces on the evolution of mesoscale systems since the potential temperature is included explicitly in the dynamic equations of the new set of equations. Further, by using the set of equations derived above, a modified potential vorticity equation more suitable for the study of mesoscale systems is developed, in which the term of divergence is involved explicitly on the right hand side. The new potential vorticity equation can be used in the study of the effect of divergence on the budget of potential vorticity and further in the discussion on the dynamic and thermodynamic processes of mesoscale systems.

Virtual Farmland Flow and Effects of Maize Sent from the North to the South

YAN Li-Zhen, CHENG Sheng-Kui, MIN Qing-Wen

2006, 23 (3): 342-348. DOI: 10.7523/j.issn.2095-6134.2006.3.010

Abstract ( 1297 ) PDF (KB) ( 0 )

the flow of virtual resources hided in grain trade is another important allocation form of water resources since 1990, except the allocation form of supply and demand side and of basin redeployment. Using the concept and method of virtual resources, the paper analyzed the virtual land flow of maize on the situation of sending grains from the Nouth to the Sorth and its impact to land resources allocation in China. Results show that the maize sent to the South reached 40 million tons that is equivalent to 5.9~9.5 million hm2 of VF. Being the main area of resources out-flowing , the Northeast China has advantages on resources, so its resources allocation is rational, while the North of China doesn’t have enough advantages, and its resources allocation need to be adjusted. Though the grain transferred can meet the grain demand from the South of China, it put high costs of social economic and ecological cost on resources out-flowing areas. In fact, Tony Allan’s Virtual Resources trade is benefit oriented, so it is necessary to allocate farmland more rationally, and provide subsidy to the farmland flowing-out area, and makeup the lost of farmland, and integrate the farmland and land into a uniform accounting form.

Geochemical Characteristics of Permian Volcanic Rocks from Jianshui , Southeast Yunnan and Their Tectonic Implication

XIE Jing, CHANG Xiang-Yang, ZHU Bing-Quan

2006, 23 (3): 349-356. DOI: 10.7523/j.issn.2095-6134.2006.3.011

Abstract ( 1398 ) PDF (KB) ( 0 )

The Permian volcanic rocks from jianshui area tectonically intrude into southwest part of Shizong-Mile fault belt. It is mainly comprised of basalts、basaltic andesites、andesites and a little picrites. Geological and geochemical characteristics show that they are formed in back-arc environment, matching with Carboniferous pillow lava from Jianshui area. These imply that Yangtze block and Cathaysia block occur plate-subduction in late Paleozoic forming the island-arc volcanic rocks, and that they produce back-arc extension in Permian, then form back-arc basin. From late Paleozoic to early Mesozoic, there is a complex trench-arc-basin system between Yangtze and Cathaysia blocks.

Quantitative Reconstruction for Lake Environmental Changes Using the Diatom-pH Transfer Function

CHENG Xiao-Ying, LI Shi-Jie

2006, 23 (3): 357-363. DOI: 10.7523/j.issn.2095-6134.2006.3.012

Abstract ( 1371 ) PDF (KB) ( 0 )

In terms of principle components analysis (PCA), detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA), a diatom-pH transfer function could be reconstructed by using the modern diatom data and pH from 34 lakes in Wales. In light of root mean square error (RMSE) and residuals results of the experiments, x-validated weighted averaging with classical deshrinking (WA_Cla_X) and x-validated weighted averaging partial least squares component 2 (WAPLS_C2_X) were selected for pH reconstruction with WA with classical deshrinking (WA_Cla) as comparison. According to these diatom-pH transfer functions, the fossil diatom in the sediment were analysed to reconstruct the pH value in Llyn Hir (lake) from 1956 to 1995. It showed that improvement of pH in 1985 was the result of liming by the history record and there was an obvious effect in the following six years but the effect weakened gradually until vanished. Although liming can increase pH in a relatively short period, it cannot eradicate lake acidification.

Effects of Galacto-Mannan-Oligosacharrides and Chlortetracycline on Growth Performance, Slaughter Performance, Serum Biochemical Indices and Pork Quality of Finishing Pigs

WANG Bin, HUANG Rui-Lin, YIN Yu-Long, LI Tie-Jun, LI Chang-Ming, ZHANG Jun

2006, 23 (3): 364-369. DOI: 10.7523/j.issn.2095-6134.2006.3.013

Abstract ( 1472 ) PDF (KB) ( 0 )

Forty-eight finishing pigs (Duroc×Landrace×Yorkshine) were randomly allocated to two groups with three replicates of each. All of pigs were fed with the same basal corn-soybean meal diet, one supplemented with 0.1% galacto-mannan-oligosacharrides (GMOS) and the other supplemented with 50mg/Kg chlortetracycline (CTC). At the end of the feeding trial for 46 days, six hogs from each replicate were slaughtered for collecting the slaughter performance and meat quality. The results were as follows: 1) Addition of 0.1% GMOS in basal diet could increase the daily weight gain by 10.2%（P<0.05）, decrease the average daily feed intake by 25.2%（P<0.01）and improve feed conversion rate by 13.2% （P<0.01）as compared with the 50mg/Kg CTC diet；2) Addition of 0.1% GMOS in basal diet could decrease backfat thickness and skin thickness by 15.6% and 11.5%, enhance the fat-free lean by 2.94% as compared with the 50mg/Kg CTC diet, but all were not significant in statistical sense (P>0.05); 3) Compared with the addition of 50mg/Kg CTC, addition of 0.1% GMOS in basal diet could significantly increase blood sugar level by 120%（P<0.05）, decrease the total cholesterol level by 3.86%(P>0.05) and decrease the triglyceride level by 42.6% (P>0.05); 4) Compared with the addition of 50mg/Kg CTC, addition of 0.1% GMOS in basal diet could significantly decrease the indole content in pig muscle（P<0.05）, however, it had not significantly influenced the other meat quality indices.

Study on Watermarking Algorithms Based on Block Singular Value Decomposition

Xiao Jun, Wang Ying

2006, 23 (3): 370-376. DOI: 10.7523/j.issn.2095-6134.2006.3.014

Abstract ( 1473 ) PDF (KB) ( 0 )

Singular Value Decomposition (SVD) is a special matrix transform with very good properties. This paper makes full use of the properties of SVD, and proposes a new quantization watermarking algorithm based on block SVD and a new spread spectrum watermarking algorithm based on block SVD. Both of the two algorithms embed watermark by altering the largest singular value of each data block, thus they can adjust the block size according to the amount of the watermark to be embedded, and their complexities are very low. The quantization watermarking algorithm is a method that makes use of the side information, and it’s a blind algorithm. The experiment results show that watermarking algorithms based on block SVD are very robust to usual image manipulation attacks, especially the quantization watermarking algorithm.

An Optimistic Fair Non-Repudiation Protocol with Semi-Trusted Third Party

DU Hong-Zhen, LI Yan-Ping, ZHANG Jian-Zhong

2006, 23 (3): 377-381. DOI: 10.7523/j.issn.2095-6134.2006.3.015

Abstract ( 1814 ) PDF (KB) ( 0 )

Based on a digital signature with message recovery, we present a new fair non-repudiation protocol with features of security, efficiency and economical use of net resources. It has the properties of fairness，non-repudiation，secrecy，termination， etc。The third party of the protocol intervenes into the exchange in case of problems，and it need not be completely trusted，because the message which is exchanged between the parties is secret to the third party。In addition， its fault can be identified。So the protocol can optimize exchanges via Internet。

Air Combat Decision-Making For Cooperative Multiple Target Attack Based on Hybrid Adaptive Genetic Algorithm

LUO De-Lin, SHEN Chun-Lin, WANG Biao, WU Wen-Hai

2006, 23 (3): 382-389. DOI: 10.7523/j.issn.2095-6134.2006.3.016

Abstract ( 1647 ) PDF (KB) ( 0 )

The Decision-Making (DM) problem is investigated for Cooperative Multiple Target Attack in air combat. It is to find a proper assignment of M friendly fighters to N hostile fighters in order to achieve the optimal expected attack effect according to the air combat situation. In this paper, the DM problem is formulated mathematically and then a Hybrid Adaptive Genetic Algorithm (HAGA) is presented for solving it. In the HAGA, a local search approach is embedded into the Adaptive Genetic Algorithm (AGA) to improve its search performance. In addition, an unconventional crossover operator is given to meet the constraints of the DM problem. Simulation experiment results show that the HAGA is more effective to solve the DM problem than the AGA.

Study on the Complex Text Layout Engine Mechanism and Its Application

ZHOU Yang-Rong, JIA Yan-Min

2006, 23 (3): 390-395. DOI: 10.7523/j.issn.2095-6134.2006.3.017

Abstract ( 1314 ) PDF (KB) ( 0 )

Two types of complex text layout engine are widely used today: one is Microsoft’s Uniscribe and the other is IBM’s ICU. By studying on its mechanism and analyzing the source code of a certain type of open source complex layout engine (such as ICU layout engine), we can add new code models which support new complex scripts (such as China’s minority language Mongolian, Tibetan, and Uigur) into the complex text layout engine and develop a version of office software based on OpenOffice for China’s minority. This paper firstly explains what the complex scripts and complex text are; then it analyzes the mechanism of the complex text layout engine; lastly it illustrates how to apply the complex layout engine to develop a version of office software based on OpenOffice suitable for China’s minority.

A Motion Estimation and Correction Algorithm for Removing Blotches in Image Squences

CHEN An-Jun, TENG Sheng-Hua, ZOU Mou-Yan

2006, 23 (3): 396-402. DOI: 10.7523/j.issn.2095-6134.2006.3.018

Abstract ( 1545 ) PDF (KB) ( 0 )

In the processing of digital video it is commonly needed to wipe out blotches in the image. Motion estimation is a basic step for this end. Sometimes, motion vectors may be far away from the true motion vector in the blotch area. Existing algorithms consider only spatial relations among motion vectors. These techniques are unsatisfactory to remove blotches completely. To improve this point, a method for estimating motion vectors considering the spatial and temporal relations among motion vectors is developed. At the same time, relations among hierarchical blocks are also considered in this paper. The result shows that the method is effective.

Two Remarks on a Forword-Secure E-cash System

Cao Zheng-Jun

2006, 23 (3): 403-406. DOI: 10.7523/j.issn.2095-6134.2006.3.019

Abstract ( 1281 ) PDF (KB) ( 0 )

The paper shows that there are two errors in the E-cash system [1]. (1) In the setup phase, the factors p1, p2 of modulus n are not published. This makes the user and the bank cannot make valid signatures in the withdraw phase. (2) The shop M must directly obtain those data (h, h1, h2, h3) used in payment phase in a secure way, instead of receiving them from a signature offered by a user U. Otherwise, the adversary can forge signatures in the payment phase. Therefore, there are four redundant data among the signature (z, a, b, r, j, h, h1, h2, h3) offered by a user.

The Implementation of 1553B Bus’ Remote Terminal Based PowerPC Processor Hardcore

YE Yong-Chen, ZHAO Guang-Heng, SU Jian

2006, 23 (3): 407-411. DOI: 10.7523/j.issn.2095-6134.2006.3.020

Abstract ( 2020 ) PDF (KB) ( 5 )

MIL-STD-1553B Bus is a standard bus which has been adopted in electronic networks of aviation, spaceflight, military etc. Our research project adopts SOPC（System On a Programmable Chip） with PowerPC405 processor hardcore embedded in FPGA to construct the remote terminal (RT) of 1553B bus with DDC’s 65170 protocol chip. In this paper, the basic points of PowerPC405 processor hardcore and Virtex-II Pro FPGA, the method of implementing HW/SW , the result of validation have been introduced.

Study of Relation Between the Partial Balance of Compression Function and the Balance of Hash Function

XI Qing, WU Wen-Ling

2006, 23 (3): 412-415. DOI: 10.7523/j.issn.2095-6134.2006.3.021

Abstract ( 1297 ) PDF (KB) ( 0 )

The balance of hash functions is a newly conception introduced by Bellare .It is a measure of the "amount of regularity" of a hash function. The complexity of birthday attack on hash functions is greatly affected by the balance of it, which will decrease quickly with the reduction of the balance. Therefore the balance of hash functions can be used as a new measure of hash functions security .In this paper we study the relation between the balance of compression functions and the balance of hash functions in MD construction. A new conception, partial balance of function, is introduced and used to analyse the relation above. It can be shown that the hash function will have a good balance on the condition that the compression function has a good partial balance.

Rhodium-Catalyzed Cycloisomerization of 1,6-Enynes with an Intramolecular Halogen Shift

TONG Xiao-Feng, ZHANG Zhao-Guo, ZHANG Xu-Mu

2006, 23 (3): 416-426. DOI: 10.7523/j.issn.2095-6134.2006.3.022

Abstract ( 1295 ) PDF (KB) ( 0 )

A Rhodium(I)-species catalyzed cycloisomerization reaction of a wide spectrum of 1,6-enynes with an unusual intramolecular halogen shift was investigated. This Rh-catalyzed enyne cyclization reaction represents a new process for the synthesis of stereodefined α-halomethylene-γ-butyrolactones, lactams, tetrahydrofurans, pyrrolidines and cyclopentanes. Coordinatively unsaturated rhodium species ([Rh(COD)Cl]2 + dppb + AgSbF6) only catalyzes the reaction with enyne substrates bearing a Z-form double bond. While neutral rhodium species (RhCl(PPh3)3) could catalyze enyne substrates bearing a Z- or E-form double bond to form the desired products and has a wider substrate scopes. The mechanism of the reaction was studied by the employment of control experiments with different enyne isomers and a π-allyl rhodium intermediate was suggested to explain the formation of the cyclic products with intramolecular halogen shift. Further transformation of the halo-alkenyl species can be readily achieved through transition metal-catalyzed Suzuki cross-coupling reactions.

Studies of Charge Transfer Processes at the Liquid/liquid Interfaces by Scanning Electrochemical Microscopy and Nanoelectrodes

SUN Peng, SHAO Yuan-Hua

2006, 23 (3): 427-431. DOI: 10.7523/j.issn.2095-6134.2006.3.023

Abstract ( 1125 ) PDF (KB) ( 0 )

In this paper, a novel method to fabricate nano-metal electrodes and scanning electrochemical microscopy (SECM) tips has been developed, and fabricated electrodes were characterized by scanning electron microscopy (SEM), cyclic voltammetry and SECM. Based on the combination of nanoelectrodes (including metal and glass pipets) and SECM, and the droplet three-electrode system developed previously by our group, we have investigated the charge (electron and ion) transfer kinetics at the polarizable liquid/liquid interfaces. The experimental results demonstrate that the facilitated ion transfer (FIT) at liquid/liquid interface is potential dependent in a certain region, and the electron transfer (ET) kinetics can be explained by using the Marcus theory when the concentrations of the redox couple for each phase are appropriate.

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