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论文
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Optimal Control of Closed Quantum Systems Based on Optimized Search Step Length
- KUANG Sen, CONG Shuang
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2006, 23 (5):
601-606.
DOI: 10.7523/j.issn.2095-6134.2006.5.006
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Abstract (
1237 )
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Equations set of a class of optimal control problems are deduced in quantum mechanical systems based on variational approach,. Furthermore, an on-off variable metric numerical iterative arithmetic with optimized search step length is used to solve such an optimal problem. Finally, some simulation experiments on a spin-1/2 particle system are done. Experimental results demonstrate the validity of the method proposed. At the same time, the effectiveness of system control under different parameters in the performance index are analyzed.
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Effects of Molecular Weights and Degree of Hydrolysis of Poly(vinyl alcohol) on its Biodegradation
- ZHANG Hui-Zhen, LIU Bai-Ling, LUO Rong, WU Yong-Zhong, LEI De-Song
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2006, 23 (5):
607-613.
DOI: 10.7523/j.issn.2095-6134.2006.5.007
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Abstract (
1176 )
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A group of Poly(vinyl alcohol) (PVA)-degrading bacteria， Bacillus sp. and Curtobacterium sp.， were isolated from watercourse and sewage sludge of Sichuan Vinylon Works，and a PVA-degrading bacterial culture was obtained. The effect of molecular weight and degree of hydrolysis on the biodegradation of PVA was investigated in above culture by spectrophotometric analysis. The results show that: the bacteria and the culture based on it can be used to study the biodegradation of PVA; a rather significant degradation within quite short incubation times was been observed; the molecular weight and degree of hydrolysis of PVA appeared to be the factors of microbial attack. The analysis of the FT-IR and 1H-NMR spectrums of the PVA sample before and after biodegradation indicated a fission of PVA chain during the inoculation.
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Effect of Ultrasonic Wave on the Polymerization of Vinyl Acetate (VAC) Emulsion
- HOU Hui-Yu, HU Jian-Qing, TU Wei-Ping
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2006, 23 (5):
614-619.
DOI: 10.7523/j.issn.2095-6134.2006.5.008
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Abstract (
1252 )
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The monomer conversion efficiency and average particle size and its distribution of vinyl acetate (VAC) polymerization by conventional and ultrasonic-assisted means individually were compared. With adding ultrasonic wave in the VAC polymerization, the monomer conversion efficiency was increased from 92.5 % to 98.8%, and the average particle size of latex was reduced from 136.7nm to 101.4nm. During the process of ultrasonic-assisted polymerization of VAC system, the effects of initiator concentration and reaction temperature on the conversion efficiency and average particle size distribution were studied. The experimental results demonstrated that the radicals generated from ultrasonic energy solely was not enough to propel the polymerization perfectly and the radicals produced by decomposition of initiator play an important role of driving polymerization. Furthermore, the mechanism of ultrasonic-assisted emulsion polymerization was briefly deduced. It also found that ultrasonic wave maintained a constant supply of radicals and these radicals were able to reactivate some of the non-active polymer chains, so that it resulted in the higher conversion efficiency of monomer.
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Research on a Remote Sensing-based Net Primary Productivity Model for Semi-arid Grasslands
- LIU Yan, ZHAO Ying-Shi, FENG Xiao-Ming, LIU Zhen-Hua
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2006, 23 (5):
620-627.
DOI: 10.7523/j.issn.2095-6134.2006.5.009
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Abstract (
1514 )
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This paper presents a regional net primary productivity (NPP) model parameterized with remote sensing information of MODIS, and tests it in areas of Inner Mongolia semi-arid grassland. The model uses the concept of Light Use Efficiency (LUE), while change of air temperature, plant-water deficits and respiration reduce the efficiency of light usage, and the model is modified to couple with ecology model to better represent regional environmental characteristics of the semi-arid grasslands. In this study, the two different ways to simulate NPP in the process of vegetation growth were introduced to calibrate model parameters. The accuracy of model products was assessed by comparing them with field measurement and other models. The NPP simulated has good linear relation with the measured (R2=0.948). The promising results suggest this model could provide spatial and temporal distribution of net primary productivity for semi-arid grassland management.
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New Methods of Determination of Conjugate Epipolor Lines in Aerial Images
- ZHAO Zu-Jun, LIU Qin-Huo, LIU Qiang
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2006, 23 (5):
628-632.
DOI: 10.7523/j.issn.2095-6134.2006.5.010
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Abstract (
1696 )
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The theories of epipolar lines have particular significance for the development of digital photogrammetry , which make the task of searching conjugate points from stereo images an one-dimensional problem. As a result, methods to determine the conjugate epipolar lines is discussed in many papers. SLL(Sloping Line Locus) is presented in this paper as an extension of VLL(Vertical Line Locus ) method. Then, based on SLL and geometric characteristics of epipolar point, this paper proposes two new methods to determine conjugate epipolar lines .The new methods are simple in theory and have explicit geometric relationship, which makes them easily applicable.
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Evaluation of Secchi Disk Transparency by Using Field Spectral Measurements in Nanhu Lake, Changchun
- DUAN Hong-Tao, ZHANG Bai, SONG Kai-Shan, WANG Zong-ming
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2006, 23 (5):
633-639.
DOI: 10.7523/j.issn.2095-6134.2006.5.011
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Abstract (
1485 )
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Secchi disk transparency is a measure of the transparency of a water body, and it is influenced by the abundance of organic and inorganic particulate and dissolved matter. Secchi disk transparency may be determined from hyperspectral remote sensing data. The advantage of high spectral resolution reflectance data (hyperspectral data) is the possibility of quantitative analysis due to diagnostic absorption bands. This study was conducted to establish correlations between hyperspectral reflectance spectra and secchi disk transparency in Nanhu Lake, Changchun．Reflectance spectra were measured from June to September in 2004, with ASD FieldSpec spectrometer. Based on in situ water sampling and reflectance measurements, algorithms have been developed. The single band R520nm, the spectra ratio of (R530-R860)/(R740-R860), and the reflectance first-derivative of 610nm, which showed a linear relationship, were all found to be significantly correlated with secchi disk transparency. The algorithms have been applied to evaluate secchi disk transparency, and the determination coefficient R2 gained using the first-derivative of 610nm was higher than that gained with other two models. The validation using independent in situ reference data showed RMSE of 4.97–9.68 m. There is satisfactory correspondence between hyperspectral models and secchi disk transparency, and it is possible to monitor the water quality of Nanhu Lake using hyperspetral remote sensing data.
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Quality Evaluation for Three Textual Document Clustering Algorithms
- LIU Wu-Hua, LUO Tie-Jian, WANG Wen-Jie
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2006, 23 (5):
640-646.
DOI: 10.7523/j.issn.2095-6134.2006.5.012
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Abstract (
2875 )
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Textual document clustering is one of the effective approaches to establish a classification instance of huge textual document set. Clustering Validation or Quality Evaluation techniques can be used to assess the efficiency and effective of a clustering algorithm. This paper presents the quality evaluation criterions from outer and inner. Based on these criterions we take three typical textual document clustering algorithms for assessment with experiments. The comparison results show that STC(Suffix Tree Clustering) algorithm is better than k-Means and Ant-Based clustering algorithms. The better performance of STC algorithm comes from that it takes accounts the linguistic property when processing the documents. Ant-Based clustering algorithm’s performance variation is affected by the input variables. It is necessary to adopt linguistic properties to improve the Ant-Based text clustering’s performance.
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An Anti-cheating Secret Sharing Scheme Based on a General Access Structure
- HUANG Gen-Xun, SHI Qiao-Lian, GAO Feng-Xiu, ZHOU Ran
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2006, 23 (5):
647-652.
DOI: 10.7523/j.issn.2095-6134.2006.5.013
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Abstract (
1527 )
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Secret sharing scheme is a kind of security protocol, which is suitable to keep secret the most important information. But it may mostly be vulnerable under the attack by cheating. Therefore it is very important to construct a scheme, which is able to withstand the attack of cheating. In this paper the authors presented an effective method of construction. It is a way to construct an anti-cheating scheme on any given access structure. By the idea of rectify error coding, it is largely improved the information rate of the scheme proposed.
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A Secure Multiple Grade Proxy Signature Scheme
- CAI Mian，KANG Li
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2006, 23 (5):
653-659.
DOI: 10.7523/j.issn.2095-6134.2006.5.014
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Abstract (
1356 )
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There are many problems in the multiple grade proxy signature schemes that are used nowadays. For example, the original signer and the proxy signers sometimes deny the truth of their signatures; the multiple grade proxy signatures usually have to be very long and the validating process of them are too complicated. To solve all these problems, a more secure multiple grade proxy signature scheme is proposed in this paper based on the study of a difficult mathematical concept, the discrete logarithm. Firstly, to ensure that none of the signers of all grades can deny their signatures, the private keys of all the proxy signers are put into the final proxy-signing key. Another feature of this scheme is that some calculation in the validating process is somehow transferred into the process of producing proxy-signing key. In this way, not only the validating of the signature is simplified, but also the multiple grade proxy signature can be effectively shortened. As a result, this paper achieve an efficient, secure multiple grade proxy signature scheme.
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Noise Robust Acoustic Model Research Based on PMC
- Zhang Ming-xin; Ni Hong; Zhang Dong-bin; Chen Guo-ping
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2006, 23 (5):
660-664.
DOI: 10.7523/j.issn.2095-6134.2006.5.015
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Abstract (
1461 )
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In noise robust speech recognition, for PMC (parallel model combination) method, the performance of the combined model can approach that of the model matching the noisy environment theoretically, so it is an important noise robust speech recognition research field. In this paper, a novel feature MFCC_FWD_BWD, which is based on forward-backward difference dynamic parameters, is presented to satisfy the requirement that the feature construction matrix is invertible for PMC. On this condition, a novel structure model named parallel sub-state hidden Markov model (PSSHMM) is presented for PMC and each state of this model has parallel sub-states with transitions. In experiment, PSSHMM achieves good results under each kinds of noise and each levels of SNR, especially for non-stationary noise, its robust performance is also excellent.
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Seamless Image Processing Based on Gradient Field Total Variation Model
- Ge Shi-ming; Cheng Yi-min; Zeng Dan; Li Jie
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2006, 23 (5):
665-670.
DOI: 10.7523/j.issn.2095-6134.2006.5.016
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Abstract (
1706 )
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This paper presents a novel framework for seamless image processing in gradient domain. A gradient field of image region to be processed is introduced into general total variation(TV) model, which gives an extended version of TV model called gradient field total variation (GFTV)model. Seamless processing is performed by minimizing the model function. Through our framework based on GFTV model, a variety of applications for seamless image processing are introduced, mainly including seamless importation of source image regions into destination image, modifying the appearance, e.g. texture, illumination, of the image seamlessly within a selected region, and image seamless stitching.
简报
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Molecular Pre-identification of Interspecies Hybrids in Prunus
- WANG Hong-Xia, YE Nai-Hao, LI Wen-Sheng, ZHANG Kai-Chun, SHU Huai-Rui
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2006, 23 (5):
671-675.
DOI: 10.7523/j.issn.2095-6134.2006.5.017
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Abstract (
1234 )
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Incompatibility of interspecies cross between sweet cherry and Cerasus tomentosa was overcome by successive of hand pollination, and the new germplasm G3 was obtained by using embryo culture technology to overcome the embryo abortion of distance hybridization. The G3 S-genotype was identified in seedling using AS-PCR, the self-incompatibility gene of parent was used as molecular marker to validate the pedigree of hybrid G3, RAPD analysis further demonstrated that G3 share characteristic RAPD fragments of both parents. This result suggested that AS-PCR was an effective and credible method to identify the progeny of interspecies hybrid in Prunus. And the cross could be a promising way to enhance the genetic background. DNA molecular marker realized the identification and pre-selection in the seedling stage. So the developing breeding program would be accelerated by the new way.
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One 3D Finite Element Method of Mesh Generation for Earth
- ZHU Gui-Zhi, ZHANG Huai, SHI Yao-Lin
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2006, 23 (5):
676-680.
DOI: 10.7523/j.issn.2095-6134.2006.5.018
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Abstract (
1330 )
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In 3D geodynamics numerical simulation research, it is often required to mesh the whole Earth or part of the spherical shell, and the size of mesh is much more important to our research. Computing meshes not only meet the need of geophysical analysis, but also avoid the computing redundancy caused by too small meshes near the core. In this paper, one structured refining meshing scheme is presented for Earth, which can make all mesh sizes in the Earth more uniform, and refine the meshes near the surface area which geophysical analysis required. And in the simple computing trial for the earth meshes generated by the mesh scheme in this paper, good results are obtained.
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Can Lake-bottom Deformation Produced by Water Unloading be Applied to the Study of Evolution of the Ancient Large Lakes in Tibet
- CUI Xiao-Jia, SHI Yao-Lin
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2006, 23 (5):
681-685.
DOI: 10.7523/j.issn.2095-6134.2006.5.019
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Abstract (
1198 )
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Some researchers suggested that there was an ancient large lake covered about 15,000,000 square kilometers in Tibet, and when the water flew away and the lakes dried up, the crust would be deformed because of the unloading. Therefore, the angle of unconformity between lake sediments may provide new evidences for further research on the lake history. In this paper, we use a simplified mechanical model to calculate the lake-bottom deformation induced by unloading of reduction of lake water. We found that the tilt of lake bottom is negligible and difficult to be detected in the field. The maximum deflection is also quite limited, only about tens of meters. However, the uplift rate may be very fast, and its effects on environment, climate and physiognomy are worth to be further studied.
简报
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Impermeability of Moist Potential Vorticity Substance and its Application
- ZHOU Yu-Shu, DENG Guo, LEI Ting
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2006, 23 (5):
692-700.
DOI: 10.7523/j.issn.2095-6134.2006.5.021
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Abstract (
1087 )
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Based on the moist potential vorticity (MPV) equation containing both heat and mass forcing, the impermeability theorem of the MPV substance (MPVS) is proved. It is clarified that mass forcing induced by intensive precipitation can lead to the MPVS anomaly. The MPVS anomaly is mainly located between 850～500 hPa. With NCEP/NCAR 11 data in Meiyu period in 1999, we find that the MPVS anomaly region corresponds well with the rain belt (include the location and movement of the rainbelt), namely, the MPVS anomaly region is mainly located on the southern side of the Meiyu front, and keeps the same orientation with iso- . According to impermeability theorem of the MPVS, the movement of the MPVS anomaly region on the isobaric can indicate the movement of heavy rain region, which may provide a possible clue to forecast the orientation of the rainbelt.
优秀博士论文
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Complexity of Dynamical System and Tuples
- HUANG Wen, YE Xiang-Dong
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2006, 23 (5):
701-707.
DOI: 10.7523/j.issn.2095-6134.2006.5.022
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Abstract (
1117 )
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In this paper, we summarize our recent work on some complexity problems in dynamical
systems related to chaos, entropy and recurrence properties under the ideas of localization (pairs or
tuples). We solve a long open problem by proving that Devaney chaos implies Li-Yorke one. We show
that there are ’many’ compacta admitting completely scrambled homeomorphisms, which include some
countable compacta, the cantor set and continua of arbitrary dimension. Using the local notions of
entropy: entropy tuples and sequence entropy pairs, we characterize the structures of a topological K-
system and a topological null system. Finally, we give a ner classi cation of recurrence properties in
terms of weak disjointness, complexity function of an open cover, and access time set.
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Deinonychosaurian Fossils from the Jehol Group and the Coelurosaurian Evolution
- XU Xing
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2006, 23 (5):
708-712.
DOI: 10.7523/j.issn.2095-6134.2006.5.023
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Abstract (
1298 )
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The osteology and integument of deinonychosaurs from the Jehol Group of western Liaoning are studied and a parsimonious phylogenetic analysis of the interrelationships of coelurosaurian dinosaurs is performed. This study: (1) provides the most detailed osteological and integumentary descriptions on Liaoning deinonychosaurs; (2) proposes an evolutionary model for feather evolution; (3) analyzes the interrelationships of the Coelurosauria; (4) evaluates the affect of combining information from different parts of the body in reconstructing coelurosaurian evolution, and (5) discusses the evolutionary trend within the Coelurosauria and particularly those features related to the origin of avian flight.
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AC Losses of High Temperature Superconducting Tapes and Coils
- ZHANG Guo-Min, LIN Liang-Zhen
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2006, 23 (5):
713-719.
DOI: 10.7523/j.issn.2095-6134.2006.5.024
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Abstract (
1259 )
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Anisotropic theoretical models of critical current and AC loss of high temperature superconducting (HTS) tape in both DC and AC background fields were established based on the effective mass theory (the anisotropy Ginzburg—Landau theory) and the critical state model (CS model). A formula to describe the relationship between critical current and stress/strain was proposed by use of the definition of irreversible strain. The relation between AC loss and stress/strain was developed based on the critical current-strain relation and Norris’ formula. A numerical model to calculate AC loss of HTS coil was developed from the anisotropy theory of AC loss and critical current of short sample.
