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25 July 2014, Volume 2014 Issue 4 Previous Issue    Next Issue

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Derivations of the even parts into the odd parts of the odd Hamiltonian Lie superalgebras HUA Xiu-ying, LIU Wen-de 2014, 2014 (4):  1-7.  Abstract ( 1398 )   PDF (245KB) ( 1780 )   Save For the problem of the derivations of the even part into the odd part of the finite-dimensional odd Hamiltonian superalgebras over a field of characteristic $p>3,$ by using the generating set of the even part and calculating the action of derivations on its generating set, the nonnegative $\mathbb{Z}$-homogeneous derivations of the even part into the odd part were determined. Furthermore, by applying the properties of the even part, the negative $\mathbb{Z}$-homogeneous derivations of the even part into the odd part were given. Therefore, all derivations of the even part into the odd part of the finite-dimensional odd Hamiltonian superalgebras were characterized, which has important significance to further study the structure, the representation and the classification of Lie superalgebras. References | Related Articles | Metrics

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On the kth derivatives of meromorphic functions and rational functions YANG Pai, LIU Xiao-jun 2014, 2014 (4):  8-17.  Abstract ( 1355 )   PDF (201KB) ( 1839 )   Save Let $f$ be a transcendental meromorphic function in $\mathbb C$, $R\not\equiv0$  be a rational function,  and let $k$ be a positive integer.  Suppose that all zeros of $f$ have multiplicity at least $k+1$,  except possibly finite many.  Then $f^{(k)}-R$ has infinitely many zeros. References | Related Articles | Metrics

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Moment estimation for a class of moving averages driven by Brownian motions HE Wei-ping, ZHANG Shi-bin 2014, 2014 (4):  18-25.  Abstract ( 1369 )   PDF (380KB) ( 1927 )   Save This paper was concerned with moment estimation for a class of moving averages driven by Brownian motions, whose autocorrelation functions take on both periodic and regressive properties. Based on investigation of the relationship between the parameter and auto-covariance function, the moment estimator of the parameter was constructed. By analyzing the spectral density of the discretely sampled trajectory, the properties of the mixing coefficient were captured. Further, the consistency and asymptotic normality of the estimator were proved. A simulation study showed that the estimator achieves good performance even in the small-sample circumstances. The real data analysis evidences that the model can be used to depict the ship hull stress data. References | Related Articles | Metrics

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Bayes premium under variance-related principles with risk dependence YU Jun, WEN Li-min 2014, 2014 (4):  26-38.  Abstract ( 1400 )   PDF (393KB) ( 1881 )   Save In a classical collective risk model, the claim numbers and claim amounts are usually assumed to be independent of each other, but in the actual business of insurance, they are generally dependent. In this paper, by introducing the concept of Sarmanov-Lee family of dependent distributions, the collective premium and Bayes premium were researched under variance-related the premium principle with the dependence between the risk profiles. Finally, the robustness of premium estimator were checked by numerical analysis. The results show that the collective premium and Bayes premium are highly sensitive even at the moderate levels of correlation between the risk profiles. References | Related Articles | Metrics

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On the spectral radius of weighted bicyclic graphs with a positive weight set LI Dan, WANG Guo-ping 2014, 2014 (4):  39-42.  Abstract ( 1442 )   PDF (199KB) ( 1695 )   Save Let $\mathbb{B}^W_{n,n+1}$ denote the set of bicyclic weighted graphs of order $n$ with the weight set $W$. In this article we determine the structure and some weight distribution of the weighted bicyclic graph with the largest spectral radius in $\mathbb{B}^W_{n,n+1}$ with a fixed weight set $W=\{w_1,w_2,\ldots,w_{n+1}\}$, where $w_1\geqslant w_2\geqslant \cdots \geqslant w_{n+1}>0$. References | Related Articles | Metrics

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Face pose estimation based on 3 points perspective DING Zhuo, TONG Wei-qing, ZHAO Ji 2014, 2014 (4):  43-53, 61.  Abstract ( 1575 )   PDF (590KB) ( 1590 )   Save This paper presents an approach of face pose estimation which is based on the feature point perspective transformation and the statistical face model. First, we build the statistic face model using three geometric feature points (2 eye points and one nose tip). Second, we deduce the corresponding relationship of the three points between the image coordination system and the world coordination system, and obtain the equations for estimating the face pose from the three points in the face image. Finally, using iterative method, we give a complete fast algorithm of face pose estimation. The experiment result shows that the proposed approach is accurate, fast and robust. References | Related Articles | Metrics

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Nose tip location based on nose contour LIU Dan, TONG Wei-qing 2014, 2014 (4):  54-61.  Abstract ( 1258 )   PDF (521KB) ( 1879 )   Save This paper presents an approach to locate nose tip using the lower contour of the nose. Firstly we determine the candidate nose area through the prior knowledge of face and the location of two eyes. Then we extract the lower contour of the nose through calculating the confidence of the nose edges that detected by Canny operator. Finally, we use least square method to fit the lower contour into parabolic curve, and then locate the nose tip. The experiment results show that the proposed approach is accurate and practical. References | Related Articles | Metrics

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Study on the extraction of Chinese microblog subjective sentences based on lexicon and corpus ZHU Hai-huan, YU Qing-song 2014, 2014 (4):  62-68, 87.  Abstract ( 1173 )   PDF (613KB) ( 2308 )   Save In this paper, we propose a new method for the extraction of Chinese microblog subjective sentence, which is based on a combination of lexicon and corpus. By determining whether the sentence contains emotional expressions, it can be classified as a subjective or objective sentence. Firstly, a highly credible sentiment lexicon was built based on the words whose emotional orientation is fixed from the existing sentiment dictionary. Based on the highly credible sentiment lexicon, sentiment expressions can be extracted with assurance of accuracy. Finally, a N-POSW model was proposed for the corpus-based learning method. Through the 2-POSW model, the remained sentiment expressions in the sentence can be extracted, thus guaranteeing the overall recall rate. Experimental results show that the F Value in this paper increases 7{\%} compared with the traditional method, which is based on the large-scale sentiment lexicon. References | Related Articles | Metrics

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Study on polyimide film humidity sensitive capacitor for high altitude meteorological observation BIAN Xiao-yue, ZHANG Jian, WANG Jian-ping, JI Chun, WU Yi-qi 2014, 2014 (4):  69-76.  Abstract ( 1434 )   PDF (780KB) ( 1763 )   Save Based on MEMS technology, a design of humidity sensitive capacitor was described. The capacitor employed sandwich structure, i.e. polyimide was used as the humidity sensitive material and gold was used as the electrodes. Capacitor shows a good pass rate of 80{\%}. As can be seen from the measurements, over the testing range from 15{\%} RH to 95{\%} RH, the maximum linearity error is 1.5{\%} RH. The sensitivity reaches 0.29pF /{\%} RH. The hysteresis is small, and the sensor has fast response time of 4~s. Meanwhile, capacitor shows good temperature coefficient and long-term stability. The results show that the comprehensive indexes of humidity capacitor are satisfactory. The capacitor is suitable for batch fabrication and can be used for high altitude meteorological observation. References | Related Articles | Metrics

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Structure-conductive property relationship of polypyrrole YU Bo, XU Xue-cheng 2014, 2014 (4):  77-87.  Abstract ( 2495 )   PDF (1700KB) ( 5010 )   Save Polypyrrole was synthesized by oxidative chemical polymerization. Samples presenting different conductivities were obtained by adjusting the preparing temperature. The polypyrrole samples have been investigated by means of four probe method, Solid state 13C NMR spectrum, XRD, FTIR spectroscopy, Raman spectrum and XPS, respectively. The experimental result suggested the fact that the conductivity of polypyrrole samples gradually decreases as the preparation temperature increases. The analysis indicates it is because the changing of internal structure follows the varying of external preparation conditions. The commonly structure of polypyrrole is a linear chain of monomers bonded by α-α carbons at a low preparation temperature. Through such a structure polypyrrole can form both a relatively planar configuration and a relatively planar conformation. This sort of structure provides the sample with a preferable regularity, a longer conjugated chain length and a higher conductivity. However, the ratio of α-α linkage drops as the preparation temperature increases, by which the structure of molecular is damaged, the degree of order declines. The carrier mobility of polypyrrole, as well as the conductive property, became lower. References | Related Articles | Metrics

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Feasibility of THz generation from DAST crystal excited by Yb-doped femtosecond laser LUO Cong-wen, ZHAO Zhen-yu, YAN Ai-min, HU Zhi-juan, SHI Wang-zhou, CHEN Zhi-zhan 2014, 2014 (4):  88-93.  Abstract ( 1341 )   PDF (930KB) ( 2057 )   Save We investigate the feasibility to generate broadband THz efficiently from the DAST crystal excited by anYttrium-doped femtosecond pulse laser. Taking account of the phase matching condition and the impact of THz absorption, we simulated the THz emission spectra of DAST, CdTe as well as GaP crystals excited at 1.03 $\mu $m. Given a fixed thickness of 0.1 mm, the DAST achieves 12 THz bandwidth, much larger than CdTe (3.5 THz) and GaP (6.4 THz). Furthermore, the maximum emission amplitude of DAST exceed beyond 10 times of magnitude to CdTe or GaP crystals. Therefore, DAST crystal is proposed to be an efficient THz emitter adapt for Yttrium-doped femtosecond pulse lasers. References | Related Articles | Metrics

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Altered white matter architecture among college athletes: A diffusion tensor imaging study SHEN Guo-hua, ZHANG Jian, WANG Hui, WU Yin, ZENG Yu-wen, DU Xiao-xia 2014, 2014 (4):  94-101.  Abstract ( 1292 )   PDF (975KB) ( 2290 )   Save Previous studies have shown that motor skill learning can induce changes involving the structural reorganization of gray and white matter architecture. However, whether learning basketball-related motor skills activates structural plasticity in the cerebral white matter is presently unknown. We used diffusion tensor imaging (DTI) to assess microstructural differences within the white matter of college basketball athletes and non-athletes. In all, 15 healthy college basketball athletes and 15 healthy college non-athletes took part in the experiments. Tract-based spatial statistics (TBSS) were used to perform a whole-brain analysis of the DTI data and to explore brain structural differences between athletes and non-athletes. Compared to non-athletes, athletes demonstrated significantly greater FA in the right middle temporal gyrus, bilateral middle occipital gyrus, right middle frontal gyrus, right frontal lobe, right precentral gyrus, left insular cortex and parahippocampal gyrus. These areas are all involved in learning motor skills and sports training. The results imply that there is an association between sports training and subsequent white matter changes. References | Related Articles | Metrics

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De novo transcriptome analysis and the phylogenetic position of glass lizards 2014, 2014 (4):  102-112.  Abstract ( 2320 )   PDF (1556KB) ( 3051 )   Save Glass lizards are a group of reptiles that resemble snake and possess many lizard's characteristics that contributed to its ambiguous taxonomy. Meanwhile, glass lizards were recorded to have many therapeutic applications in TCM. Hence, we present the sequencing, de novo assembly and annotation of transcriptome from \textit{Ophisaurus}\textit{ harti}'s gastrointestinal tract. A total 4.6~Gbp of high quality data was generated, 58~959 unigenes were assembled and 35~708 (60.56{\%}) unigenes were annotated to the public databases. To understand the evolutionary relationship among glass lizard, snake and lizard, ortholog gene families and phylogenic tree were performed, and the results all showed that \textit{Ophisaurus}\textit{harti} is more closely related to the snakes than to the lizard. A total of 10~613 cSSR markers from the \textit{Ophisaurus}\textit{harti} transcriptome were identified and 1~644 markers were obtained using at least one primer with a strict criterion. This is the first time to give insight into the transcriptome and phylogenetic evolution in \textit{Ophisaurus harti}. These sequences and markers will provide valuable sources for \textit{Ophisaurus harti} studies. References | Related Articles | Metrics

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Isolation and identification of lignin decomposing bacteria and cloning of lip gene in termite gut GAO Yun-hang, WANG Wei, LIU Meng, GOU Chang-long, LOU YU-jie, MA Hong-xia 2014, 2014 (4):  113-121, 179.  Abstract ( 1402 )   PDF (1047KB) ( 1894 )   Save A strain of bacterium that named PY12 was isolated from the termite gut using Azure B method, which had an efficiently lignin decomposition function. It was identificated as \textit{Enterobacter hormaechei}. by morphological, biochemical identification and\\ 16S rRNA identification. The $lip$ gene were amplified by the specific primers, and then cloning it into pMD19-T vector, the target fragment sequences were 918 bp, Homology comparison with the $lip$ gene which known in GenBank, the Homology was low, but when the nucleotide sequences were translated into protein, the homology was up to 88.5{\%} with the Pseudomonas sp.. References | Related Articles | Metrics

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Study on photocatalytic degradation of methylene blue by BiOBr under visible light ZHU Pei-juan, CHEN Wei, LI Chun-yan, ZHAO Ya-ping 2014, 2014 (4):  122-131.  Abstract ( 2073 )   PDF (2564KB) ( 2290 )   Save This paper studied the photocatalytic degradation of the methylene blue (MB) by BiOBr under visible light. The influence factors, such as pH, amount of catalysts and the concentrations of reaction solution were investigated so as to check the performance of the process and understand the mechanism of degradation of MB. The inhibition of reactive oxygen species (ROS) in the reaction system was determined by adding various radical scavengers. Above results help to deduce photodegradation mechanism of MB catalyzed by BiOBr and the mainly active oxygen species in the reaction system. References | Related Articles | Metrics

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Study on species identification of submerged aquatic vegetation based on spectral characteristics ZOU Wei-na, ZHANG Li-quan, YUAN Lin 2014, 2014 (4):  132-140.  Abstract ( 1544 )   PDF (1045KB) ( 2937 )   Save The among-species spectral characteristics of submerged aquatic vegetation (SAV) could provide effective parameters for species identification to timely monitor the distribution and growth status of SAV using remote sensing technology. In this study, the spectral reflectance of the typical SAV plants were measured using a FieldSpecTM Pro JR Spectroradiometer in Dianshan Lake, the largest natural freshwater lake in Shanghai suburbs, including 6 SAV species Najas marina, Hydrilla verticillata, Myriophyllum spicatum, Ceratophyllum demersum, Vallisneria natans and Potamogeton malaianus. The spectral characteristics of reflectance curves and first derivative curves for different species were analyzed, while vegetation indexes and spectral indexes were screened for identifying species of SAV using Principal Components Analysis (PCA). The results show that the reflectancecurves were similar in shape but much variable in magnitude at the visible and near infrared wavebands for different SAV species. The spectral index NAV, REP and NGP were the most sensitive characteristic index for identifying 6 SAV species. The index NAV, REP and NGP could well reflect and amplify the differences in morphological structure of plant, physiological and biochemical composition among different SAV species and the among-species discrimination of their habitat synthetically. The results from this study could be helpful to accurately interpret the community composition, distribution and biodiversity dynamics of SAV on a large scale from hyperspectral remote sensing image. References | Related Articles | Metrics

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Effects of reclamation on phytoplankton community structure and biodiversity in Jiaojiang Estuary WANG Chun-ye, ZHOU Bin, DING Xiao-dong, HUANG Bei 2014, 2014 (4):  141-153，179.  Abstract ( 1522 )   PDF (5247KB) ( 1936 )   Save Investigations on phytoplankton of Jiaojiang Estuary（28.67°~28.69°N, 121.45°~121.62°E） were carried out in July 2007, July 2008, and August 2010, and compared with historical data. 5 Phylums and 167 species were identified in the three investigations which were 101, 96 and 117 respectively before，inning and after reclamation. Cell abundance of phytoplankton were 20.34×103 cell /L, 266.94×103 cell /L and 66.94×103 cell /L, and Shannon-Wiener Index of phytoplankton were 1.95, 0.60 and 0.40 respectively. Dominant species of phytoplankton included Bacillariophyta and Pyrrophyta before and after reclamation, such as Coscinodiscus jonesianus, Coscinodiscus radiatus, Skeletonema costatum, Rhizosolenia delicatula, but only Bacillariophyta existed inning reclamation, such as Chaetoceros lorenzianus and Ditylum brightwellii. Reclamation promoted the enhancement of cell abundance but reduced the stability and balance of phytoplankton community structure. CCA analysis showed that pH, temperature, nitrogen/phosphorus/silicon nutrients, dissolved oxygen and chemical oxygen demand were the main water quality parameters affecting community structure of phytoplankton. The main water quality parameters affecting Chlorophyta, Bacillariophyta, Cyanophyta and Pyrrophyta were dissolved oxygen, oil, temperature and chemical oxygen demand respectively. Long time scale and short time scale analysis come to similar conclusions that water quality , community structure and biodiversity of phytoplankton have changed before and after reclamation of Jiaojiang Estuary. References | Related Articles | Metrics

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Saltwater intrusion in the Changjiang River Estuary during the drought in late the spring and early summer of 2011 GU Sheng-hua 2014, 2014 (4):  154-162.  Abstract ( 1498 )   PDF (3877KB) ( 1652 )   Save The drought events happen in the Changjiang River basin with increasing frequency in recent years due to the global climate change. There was a drought event at the middle and lower reaches of the Changjiang River in the late spring and early summer of 2011, resulting in the river discharge at Datong station in April, May and June of 2011 decrease 33.4%, 50.6% and 50.3%, respectively, compared with the corresponding monthly mean values. The observation data indicated that in the April salinity at Chongxi hydrological station exceeded 0.45 (standard of drink water) in the most measured time, the saltwater spilling over from the North Branch took about 2 days and 3~5 days from Chongxi hydrological station to Nanmen and Baogang reservoir, respectively, the not suitable water intake time was 2 and 4 days at Baogang reservoir, 5 and 4 days at Qingcaosha reservoir. In the middle and late May, it was still occurred by high saline water at Yonglongsha in the North Branch, it reached 7 days that salinity exceeded the drink water standard at Chongxi hydrological station, the not suitable water intake time was 8 days at Qingcaosha reservoir. During the observed 5 tidal periods from 4 to 7 in June (middle tide after spring tide), salinity near Dongfenxisha reservoir water intake was higher than 0.45 in about half observation time, was lower than 0.45 near Chenhang reservoir and Qingcaosha reservoir water intakes, but increased gradually with time, indicating that the salt there come from the saltwater spilled over from the North Branch. The saltwater intrusion in the Chnagjiang River Estuary happens generally in December and next January to March, and vanishes in April to June with the increasing river discharge. The drought event induced by climate change enhanced the saltwater intrusion and influenced severely the safety of water intake in the Changjiang River estuary in the not period of saltwater intrusion. References | Related Articles | Metrics

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Impact of the reclamation project of Xincunsha on the saltwater intrusion in the North Branch of the Changjiang Estuary CHEN Jing, ZHU Jian-rong 2014, 2014 (4):  163-172.  Abstract ( 1680 )   PDF (4933KB) ( 2237 )   Save The reclamation project of enclose Xincunsha and block its southern channel in the North Branch of the Changjiang Estuary was conducted in 2012, resulting in the river regime changed artificially. Considering the monthly mean river discharge and wind in January and February, the 3-D saltwater intrusion numerical model in the Changjiang estuary, which has been applied, improved and validated for long-term, was used to investigate the influences of the saltwater-spill-over (SSO) from the north branch into the South Branch and the water intakes of Qingcaosha, Chenhang and Dongfengxish reservoirs due to the project. The saltwater intrusion is enhanced and salinity increases 0.05~0.10 downstream Xincunsha, whereas is weakened and salinity decreases 0.05~1.0 upstream Xincunsha due to the project. The tidally averaged salt fluxes of SSO cross the section at upper reaches of the North Branch reduced 7.52%, 16.48%, 10.17%, 6.49% during moderate tide following spring tide, neap tide, moderate tide following neap tide, spring tide after the project, respectively. The reduce of the SSO induces an increase of freshwater area in the South Branch. The tidally averaged surface salinity at the water intakes of reservoir during moderate tide following spring tide, neap tide, moderate tide following neap tide, spring tide is reduced by 4.52%, 10.23%, 9.15%, 5.81% at Dongfengxisha, by 10.59%, 13.11%, 32.89%, 13.95% at Chenhang, and by 10.50%, 8.19%, 9.17%, 11.99% at Qingchaosha, respectively. Correspondingly, the longest continuous unsuitable days for water intake decrease from 10.1 to 9.3 days at Dongfengxisha, from 5 to 4.4 days at Chenhang, and from 6.2 to 5.1days at Qingchaosha. The reclamation project of Xincunsha narrowed water flow cross section, and weakened the SSO, which is favor of the utilization of freshwater in the South Branch. References | Related Articles | Metrics

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Application of BD RDSS for marine data transmission HE Si-long， YE Fang-zhou， WANG Yuan-fei 2014, 2014 (4):  173-179.  Abstract ( 1555 )   PDF (998KB) ( 2346 )   Save The ocean is always one of the biggest blind spot of traditional communication technologies. Because of lack of effective means of communication, resulting in information communication difficulties between ship and shore, highly informatization of offshore marine engineering ships have become floating “information islands” in the sea. Beidou Satellite Navigation System has integrated navigation and communication, which has provided a feasible technology way to solve the  Vessel-Shore Integration. This paper proposed a Beidou cluster data transmission technology solution based on short message communication principle of Beidou RDSS (radio determination satellite Service), which solves the problem of large amount of data transmission for marine engineering ships. The software can transmit thousands of physical quantity containing ship machine state data, construction condition data, position information to shore command center in real-time through the development of the communication protocol, the establishment of an effective algorithm of data processing and compression algorithms, which realizes the Vessel-Shore Integration of offshore operations and provides an information technology security for the ship scheduling of production and business management. References | Related Articles | Metrics