Table of Content

20 May 2012, Volume 48 Issue 3

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Design and Experimental Investigation of Blunt Aero-Valve for Air-Breathing Pulse Detonation Engine

ZHENG Dianfeng,YANG Yiyong,WANG Jiahua

2012, 48(3):  347-353. 

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Based on the studies of collaborative optimization for the air-breathing liquid-fuel pulse detonation engine (PDE), a kind of blunt aero-valve is designed to guarantee the trapping efficiency, reduce the resistance, improve the detonation performance and augment the thrust. The diameter of the inlet valve and the blunt thrust wall are the same as diameter of the detonation tube. A cylindrical groove is slotted in the thrust wall and an annular channel is set on the outside of the blunt body. There is a reasonable clearance between the blunt body and the inlet of the annular channel. Experiments show that the PDE with blunt aero-valves with different detonation tube diameters can work in coordination; the detonation combustion performance is better than that of swirling aero-valve; when the fuel is supplied on the front of the aero-valve, the detonation combustion performance is better.

Embedding Carbon Nanotubes into Nano-Trenches by Selective Wet Etching

ZHAO Huabo,ZHANG Zhaohui

2012, 48(3):  354-358. 

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The authors present a “bottom-up” method, that is, a palladium film of several nanometers thickness is deposited on the carbon nanotubes (CNTs) grown on a silicon substrate covered by SiO2, then etched in fluorhydric acid solution, the nanometer-sized trenches, which are fully guided by the CNTs located at the bottom of the trenches, are formed. By performing conducting atomic force microscopy measurement, the CNTs inside the trenches were found to have a good electrical conductivity. If an additional silicon oxide layer was predeposited by magnetron sputtering on CNTs before the deposition of palladium film, the aspect ratio of trenches could be increased. By reducing the density of palladium film, the opening width of the trench would be reduced to about 100 nm. This structure with carbon nanotubes embedded in trenches could be further prepared to build nanoelectronic devices based on CNTs.

Studies on Improving the PL Spectra of ZnO Nanowire

WANG Xiaowei,SUN Yanghui,WANG Wei,ZHU Rui,ZHU Xinli,HOU Yumin

2012, 48(3):  367-370. 

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ZnO nanowires were grown through CVD method, and SEM, TEM and PL spectroscopy system were used to characterize its morphology, crystal structure and optical properties. Due to the effect of Au SPR on ZnO nanowire, its PL spectra increased by 20 times at the UV region and decreased remarkably at the green region when it was coated by Au film. Through the annealing experiments, the competition mechanism between intrinsic transition and defect transition in ZnO material proved to be of great effect on its PL spectra. The results showed that the intrinsic transition of annealed ZnO nanowire decreased remarkably, while its defect transition increased. When coated by Au film, the PL spectra of annealed ZnO nanowire increased by almost 30 times at the UV region. The improvements are more remarkable than those reported results.

Dimerized Phases in Spin Ladder with Four-Spin Ring Exchange

WEN Rui,LIU Guanghua,TIAN Guangshan

2012, 48(3):  359-366. 

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The authors investigate the phase diagram of a frustrated spin ladder model with four-spin ring exchange by bosonization technique and renormalization group method. After having taken effects of quantum fluctuations into account, the phase diagram of the system becomes very complicated. Besides the existences of Haldane phase, rung-singlet phase and the staggered dimerized (SD) phase, there is a columnar dimerized (CD) phase emerging.

Function Control Method for GaN Heteroepitaxy by HVPE

DU Yanhao,LUO Weike,WU Jiejun,John Goldsmith,HAN Tong,YANG Zhijian,YU Tongjun,ZHANG Guoyi

2012, 48(3):  371-375. 

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A new growth control way, Function Control Method, is introduced in GaN heteroepitaxy by hydride vapor phase epitaxy (HVPE). Function Control Method is a growth control way in which growth parameters vary as certain mathematical functions of time. Two growth schemes are designed by the aid of this method to solve two main problems confronted in obtaining free-standing GaN substrates by HVPE. In the heteroepitaxial growth scheme of crack-free high-quality thick film, growth parameters’ variations as gradual functions of time ensure that the growing of high-quality GaN maintains sustainable advantage while the strain is being released gradually. Besides, the periodic functions turn the problem of thick-film heteroepitaxy into an easy one of thin-film heteroepitaxy. In the separation scheme of the thick epilayer, growth parameters’ twice sharp transitions produce a weakly connected thin interlayer. Also, except for the twice sharp transitions, growth parameters’ variations as gradual functions of time bring about stress difference between two sides of the weakly connected thin interlayer. The stress difference can be further intensified during the cooling process, leading to the thick epilayer’s self-separation at the weakly connected thin interlayer. With the combination of the two schemes, 1 mm-thick transparent GaN crystal with a smooth surface was obtained, which proved the effectiveness of Function Control Method. Relying on growth parameters’ regular orderly change over time, this method develops new ways of material growth control, and links properties of the growing material with the mathematical functions according to which growth parameters vary.

Mitochondrial Genome Structure of Yellow River Catfish (Silurus lanzhouensis) and Phylogenetic Analysis

WANG Qingrong,XU Chang,XU Chongren,WANG Rongjiang

2012, 48(3):  376-380. 

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Reffering to mitochondrial genome of Silurus glanis, the authors designed 6 pairs of primers for the long and accurate PCR amplification of a Yellow River catfish (S. lanzhouernsis). Sequence analysis indicated that the mitochondrial genome of S. lanzhouensis has 16524 bp necleitides, comprising 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a non-coding control region. The phylogenetic analysis of 11 species in Siluriformes was conducted with maximum likelihood method based on nucleotide sequence of all protein-coding genes. The result shows that S. lanzhouensis had close phylogenetic relationship with other species in Siluridae.

A New On-Chip Jitter Measurement Method Based on Cumulative Distribution Function

GUO Jian,FENG Jianhua,YE Hongfei

2012, 48(3):  381-385. 

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The authors present a new on-chip jitter measurement method based on cumulative distribution function (CDF) to solve the problem of the mismatch of the delay line, taking up too much chip area and limited by high frequency oscillator signal, which are encountered in measuring multi-GHz clock jitter. The complete circuit is designed and implemented based on the 65 nm CMOS process. The simulation results show that the circuit is able to operate at 2.5 GHz and achieves a timing resolution up to 1 ps.

A Method for Measuring Aerosol Activation Ratios with High Size Resolution

DENG Zhaoze,ZHAO Chunsheng,MA Nan,ZHANG Qiang,HUANG Mengyu

2012, 48(3):  386-392. 

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A method for measuring size-resolved activation ratios with high size resolution is introduced. The number size distributions of aerosols and cloud condensation nuclei, along with the size-resolved activation ratios, can be inverted with an improved inversion algorithm. The method was tested during field measurements for atmospheric aerosols.

Sunshine Duration’s Trend Behavior Based on EEMD over China in 1956-2005

LI Huiqun,FU Zuntao

2012, 48(3):  393-398. 

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The daily sunshine duration data in 1956?2005 from national meteorological information center are used to analyze the sunshine duration’s nonlinear trend behavior over China by the method of ensemble empirical mode decomposition (EEMD). The sunshine duration exhibits different nonlinear trends over different regions and in different seasons, most of them (over nearly 67.5% stations) show a descending trend, especially over the south and northeast China. The multi-decadal variability appears a climate shift in 1980s with the longer sunshine in the earlier stage and the shorter in the late part.

Comparative Analysis to Multi-fractal Behaviors of Relative Humidity and Temperature over China

GAO Lihao,FU Zuntao

2012, 48(3):  399-404. 

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The different multi-fractal behaviors of relative humidity and temperature over China are studied by means of multi-fractal detrended fluctuation analysis (MF-DFA for short) method. Three multi-fractal parameters (the spectrum width Δα, the asymmetry Δα_as?as and the long range correlation index α₀) of singularity spectrum are introduced to quantify the multi-fractal behaviors. Results show that multi-fractality in humidity daily records are stronger than that of temperature’s; stations with strong multi-fractality of relative humidity and temperature lie in different regions: southwest of China for relative humidity and South China and north of the Yellow River for the latter; asymmetry of singularity of relative humidity records is weaker than that of temperature’s and their singularity spectra exhibit left-skewed; singularity spectrum of temperature records exhibit symmetry on the whole; long range correlation of relative humidity records is higher than that of temperature’s. Combination of three parameters of multi-fractal spectrum stands for a kind of long range correlations and different behaviors of them reveal different dynamics underlying relative humidity and temperature.

Seismic Inverse Q Filtering Using Malvar Window Based Time-Frequency Analysis

ZI Libo,GE Zengxi

2012, 48(3):  405-410. 

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A new inverse Q filtering method based on the time-frequency analysis using Malvar wavelet decomposition is proposed. Firstly, the forward phase and amplitude propagator based on mathematical model in anelastic model are computed. Then the composition process is considered as an inverse propagator. The operator is the function of Q, frequency, and travel time, through the frequency-time analysis based on Malvar wavelet decomposition. The proposed method is used to compensate the synthetic seismic trace produced by boundary element method. The result shows that it can correct amplitude attenuation and phase distortion effectively and stably.

Lithologic Mapping Using EO-1 Hyperion Data and Extended OCSVM

ZHANG Xiya,XU Haiqing,LI Peijun

2012, 48(3):  411-418. 

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An extended one-class support vector machine (OCSVM) was applied to lithologic mapping from the EO-1 Hyperion hyperspectral data, and it has been evaluated in terms of classification accuracy. First OCSVM was separately used to extract each lithologic unit of interest. The pixel which was classified to different classes simultaneously was then assigned as the class with smallest distance to the hyperplane. In this way, the extended OCSVM can be used for extracting several lithologic units of interest. The extended OCSVM method was used in lithologic classification from the EO-1 Hyperion hyperspectral data in Junggar area, Xinjiang and compared with the spectral angle mapper (SAM) method. The results showed that the extended OCSVM method outperformed the SAM method in lithologic classification. The extended OCSVM is a useful and effective method for lithologic classification from hyperspectral remote sensing data.

Features of Multistage Cretaceous Conglomerate Deposition and Its Palaeo- geographic Significance in Jixi Basin of Eastern Heilongjiang, NE China

ZHAO Xueqin,YANG Shufeng,CHEN Hanlin,ZHANG Fengqi,ZHANG Yunpeng,YANG Chengzhi,SUN Mingdao

2012, 48(3):  419-432. 

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The results of gravel counting in different periods of cretaceous in Jixi basin shows that lower cretaceous gravel mainly consist of quartzite and granite, which is consistent with the outcrop lithology of pre-mesozoic basement in its periphery. In the contrast, rhyolite, andesite, tuff are growing in number in upper cretaceous Houshigou formation, and quartz sandstone and boulder clay can be found, hence indicating that the early mesozoic strata partly supply sediments. The shape of gravels chiefly changes from subangular to round, and the ratios between its long axis and short axis vary within 1?2 mostly, in small gravel primarily, particle size length conforms to the normal distribution. Sedimentary environment discriminant function displays that gravel mainly belong to rivers (delta) causes. Based on the analysis of gravels, the west of the basin and paleo-uplift supply sediments during the sedimentary stage of the Chengzihe formation. The deposition from Chengzihe formation to Muleng formation is the course of water expending. In the middle and late sedimentary stage of the Muleng formation, the western becomes the mainly continental provenance followed by the further expansion of the transgressive range. During late cretaceous, the basin and its periphery occurs uplift and subjects to erosion because intensely fold-thrusting, deposit Houshigou formation in the low-lying region.

Magmatic Hydrothermal Fluids-Formation Water Compound System and Diagenetic Response of Carbonate Reservoir Rocks in Northern Tarim Basin

CUI Huan,GUAN Ping,JIAN Xing

2012, 48(3):  433-443. 

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Through the petrographic studies, it is found that the carbonate rocks in Northern Tarim Basin have developed a diagenetic paragenetic sequence of silicification → hydrothermal dolomitization → calcitization. Many lines of evidences, such as the quartz fluid inclusion with a high salinity and homogenization temperature, the positive Eu anomaly in REE pattern of the saddle dolomite, and the calculated δ¹⁸O_SMOW (+5.5‰ ? +12‰) of the fluid which precipitated the calcite crystals, all indicate that there exist magmatic hydrothermal fluids. It is also found that the hydrothermal diagenetic fluids have been mixed with organic carbon, meteoric water or the ⁸⁷Sr rich formation water in different degree. The carbonate rocks in the research area have a corresponding diagenetic response to the “magmatic hydrothermal fluids-formation water compound fluid system”. The magmatic hydrothermal fluids is an important source of Si and REE to the diagenetic fluid flow and is also a heat source that drives the magmatic hydrothermal fluids and formation water cycle underground. The acid dissolution mechanism indicates that the open fault area is a promising target for the petroleum reservoir exploration in the future.

Research on Spatial Relationships Calculation Model Based on EMD Subdivision Architecture

DONG Fang,CHENG Chengqi,GUO Shide

2012, 48(3):  444-450. 

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There are two problems in spatial relationships calculation: the latitude and longitude coordinate lacks of area attribute and the directly spatial relationships calculation on remote sensing images is complex. To these problems, the EMD (the extended model based on mapping division) subdivision cell is used as the basic unit in calculation, instead of the latitude and longitude coordinate. The spatial relationships calculation architecture based on EMD subdivision is also proposed. The experiment about the architecture confirms the feasibility of this new calculation model.

Spatiotemporal Inventory of Biogenic Volatile Organic Compound Emissions in China Based on Vegetation Volume and Production

CHI Yanqi,XIE Shaodong

2012, 48(3):  475-482. 

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To estimate the spatiotemporal distribution of biogenic volatile organic compound (BVOC) emissions in China, this study collected data on vegetation volume and production from the national forest and grassland inventory, Statistical Yearbooks, and a 1:1000000 vegetation map of China. These data were converted to leaf biomass data and then used in Guenther’s BVOC emission model, and spatiotemporal and source distributions of BVOC emissions were estimated, establishing a BVOC emission inventory for mainland China. In 2003, the annual total BVOC emission in China was estimated to be 12.83 Tg, composed of 7.45 Tg (58%) isoprene, 2.23 Tg (17%) monoterpenes, and 3.14 Tg (25%) other VOCs (OVOCs). Emissions varied significantly among plant species, with contributions to total emissions by vegetation type ordered as follows: forests (61%) > shrubs (27%) > crops (7%) > grasslands (5%). Southern and northeastern China were the main sources of BVOC emissions. Significant seasonal variation was found in the BVOC emissions. The most emissions occurred in summer. Forest contribution to BVOC emissions varied by age class, with middle-aged forests contributing the most.

Modeling Dynamic Networks in Temporal GIS and Realization Methods

LIU Yuefeng,LU Min,YANG Zhongzhi

2012, 48(3):  451-458. 

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A mathematic expression of dynamic network and dynamic link object which is the basic unit of dynamic network is introduced. Evolutions of dynamic link object are classified into three types which are geometrical evolution, topological evolution and life evolution. Modeling life evolution could express inheritance relationship between two dynamic link objects. Nine kinds of evolution events of dynamic link object are defined, they are “New”, “Break from”, “Merge from”, “Die”, “Break into”, “Merge into”, ”Deformation”, “Meet”, “Leave”. A spatiotemporal data model of dynamic link object with consideration to geometrical, topological and life evolutions is established. This data model makes data operations and updates relatively easier. At last, the basic operators on dynamic link object are designed and integrity rules are raised.

Study on Urban Change of the Yangzhou City within 2500 Years Based on 3S

YANG Jing,ZHANG Jinchi,ZHUANG Jiayao,MAO Feng

2012, 48(3):  459-468. 

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Yangzhou City, which lies besides the north bank of the Yangtze River, was built in B.C. 486. Within 2500 years, it experienced great developments and changes in several important historical periods (Spring and Autumn, Han Dynasty, Jin Dynasty, Tang Dynasty, Song Dynasty, Ming and Qing Dynasties). Based on literature of historical geography and archaeological data, using the historical geography method and 3S (GIS, RS and GPS), this study integrated estuary change, river bank change and canal change with urban change of Yangzhou City. Firstly, the boundary of the Yangzhou City was made on the images in Sept. 2006 of the LANDSAT ETM remote sensing data based on its administrative map; then according to history literature and archaeology data, key points for the boundary of the Yangzhou City were selected and located by GPS field observation and stacked with the RS image, using ArcGIS9.3 to simulate the change process of the Yangtze River in different periods and acquire its attribute data quantitatively, based on which, characteristics of urban change were analyzed in six historical periods and the driving factors for the urban change were discussed. The results show that climate change was the background of urban changes of the Yangzhou City, but these changes were also affected by several other factors. The changes of the Yangtze River channel and the Hangou Canal guided the changes of the Yangzhou City. The spatial changes of the bank of the Yangtze River and of the Hangou Canal in different periods were estimated. The silted area and water area of the Yangtze River within Yangzhou City in historical periods were calculated. The changes that took place in the ancient Yangzhou City were caused by the silt of the Yangtze River moving the bank southward by deposition on its northern bank, which in turn resulted in the necessary extension of the Canal for shipping. The city extended its area, following the extension of the Canal. Even when the city decreased in size, it did so by retreating back towards the Canal. In general, before the Tang Dynasty, the city was changed mainly by natural factors and after the Tang Dynasty by human factors.

Water Quality Early Warning Research of Water Intakes in Huainan

CHEN Hongyang,REN Huatang,XU Shiying,XIA Jianxin

2012, 48(3):  469-474. 

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Basing on the river hydrodynamic conditions and water pollution emission of Huaihe River in Huainan, a river model was developed. The authors simulated and analyzed the water quality index changes in different seasons and the response time of each waterworks intakes in case of pollution accident emergency. The simulation results show that during dry and wet seasons the water quality of the upstream monitoring section are as follows. COD: 27.5 and 21.0 mg/L; NH₃-N: 0.65 and 0.97 mg/L; Ecoli: 10490 and 10050; TN: 1.05 and 1.01 mg/L; TP: 0.21 and 0.20 mg/L. When changing the upstream pollution load, the response time of each waterworks are different, Li Juzi waterworks: 1.275 and 0.216 days during dry and wet seasons. It would provide decision support for the water pollution accident early warning and emergency response.

Application of Quadratic Almost Ideal Demand System in Analysis of Demand Elasticity of Household Water Demand of Beijing

MA Xunzhou,ZHANG Shiqiu,MU Quan

2012, 48(3):  483-490. 

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The authors use the Quadratic Almost Ideal Demand System (QUAIDS) to analyze the household water demand of Beijing which holds multi-attributes as the case study with comparison to double logarithmic demand model and Almost Ideal Demand System (AIDS). The results show that 1) for the lowest income groups, Engel Curves of household water demand are linear, however, for the higher income groups, Engel Curves are non-linear; 2) values of income elasticity of different income groups from QUAIDS are generally higher than those from double logarithmic demand model and AIDS and values of price elasticity are close.

Can Emission Trading Policy Help Restructuring Industry? A Case Study in Shenzhen of China

WAN Wei,ZHANG Shiqiu

2012, 48(3):  491-499. 

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Based on results of an empirical study in Shenzhen, this paper discusses the feasibility that whether the environmental economic policy can be used to restructure polluting industry while improving environmental quality by reflecting the value of environmental capacity and balancing the needs for development and environment. The empirical and case study focuses on water pollution and electronic equipment manufacturing industry. Considering the environmental management challenge and superiority of environmental economic policy, the feasibility and difficulties of applying emission trading in Shenzhen river basin are analyzed. Further, policy impact analysis estimates effect of industry restructuring and abatement cost saving based on the empirical and case study in a typical electronic equipment manufacturing industry. The result shows that a flexible pollution control and industry restructuring system associated by emission trading and current policies such as reuse reclaimed water has comparative advantages on polluting firms elimination, emission abatement and technology promotion.

Team Conflict, Team Trust and Organizational Citizenship Behavior: The Mediation Effect of Organizational Justice

Aiqin,SHI Junqi,LIU Yihao,SHEN Xiuqin,SU Yonggang,CHEN Xiaoyang

2012, 48(3):  500-506. 

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By using a sample of 241 employees working in hospitals, the present study examined the relationships between team conflict, team trust and organizational citizenship behavior (OCB), and the mediating role of organizational justice. Hierarchical linear regression analysis showed that organizational justice partly mediated the relationship between team conflict and OCB and fully mediated the relationship between team trust and OCB. Implications of these results and directions for future research are discussed.

How Self-efficacy Affect Active Job Search Activities: Moderate Effect of Emotion Regulation

SHENG Zitong,SHI Junqi

2012, 48(3):  507-512. 

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By using a sample of 338 undergraduates from various regions, the present study examines the relationship between job search self-efficacy and active job search on the basis of social cognitive theory, goal-gradient perspective and control theory, along with Blau’s two-dimension job search model and the dynamic view of job search. Moreover, individuals’ regulation of emotion moderates the relationship stated above, and only for those poor in emotion regulation, active job search is positively related to job search self-efficacy. The results extend existing research framework by discovering the effect of individual difference in the mechanism of job search. The current study also comes up with some suggestions in searching for jobs.

Natural Disasters Risk Assessment Based on Information Diffusion Model: Application and Improvement

MAO Xiyan,MENG Jijun,KANG Yufang

2012, 48(3):  513-518. 

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Comparing with other traditional approaches like the probability statistics method and the multi-criteria decision-making method, this paper discusses the applicability and relative merits of the Information Diffusion Model (IDM). It reveals that the IDM is a straightforward approach with a definite result requiring fewer data, which meets the requirement of disaster risk assessment and has significant value for decision. Therefore, the IDM is wildly used in the natural disaster risk assessment, especially in the case of limited samples or unknown probability distributions. However, the IDM is limited in describing the comprehensive aspect of the disaster risk, and some detailed rules should be clarified further when putting the model into practice. In order to improve the IDM method, extend the range of IDM’s applicability, and provide an approach for comprehensive disaster risk assessment, this paper puts forward a scenario-based IDM by combining the scenario analysis method with the traditional IDM method.