[an error occurred while processing this directive]

Table of Content

    20 November 2017, Volume 53 Issue 6
    Orginal Article
    Design and Implementation of a Lower Extremity Exoskeleton for Walking Assist
    Zheng XIE, Mingjiang WANG, Wulong HUANG, Shanshan YONG, Xin’an WANG
    2017, 53(6):  989-996.  DOI: 10.13209/j.0479-8023.2017.056
    Asbtract ( )   HTML ( )   PDF (2495KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The weight support manner is proposed to enhance wear comfort of the wearable exoskeleton. The design of one-way clutch with the mechanism of ratchets and pawls reduces the weight of the exoskeleton. In the aspect of control, through gait analysis and the feedback control which is the current PID control in PID mode as the inner ring and the plantar sensor and the seat sensor as the outer loop, it achieves intelligent human-computer interaction. The exoskeleton weighs nearly 12.5 kg. The support is about 10 kg for standing and 3 kg for walking. The battery life is more than 2 hours.

    Key Extraction Schemes for SRAM PUF
    Liangliang ZHANG, Yiwei ZHANG, Ruiyi SUN, Yuan ZHOU, Xin’an WANG
    2017, 53(6):  997-1002.  DOI: 10.13209/j.0479-8023.2017.059
    Asbtract ( )   HTML ( )   PDF (370KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To acquire unique and random keys for chips from PUF, key extraction schemes for SRAM PUF are introduced. These schemes include the hard-decision and soft-decision decoding ones involving concatenated error-correcting code. By the actual responses of SRAM PUF’s on chips and software simulation, the effect of above two schemes is verified. The result shows that, for SRAM PUF, the soft-decision scheme is more reliable and efficient.

    Doppler Frequency Shift Estimation on High-Maneuver Airborne Platform Based on UKF
    Huaijin YU, Na YI, Wei JIANG, Feng YANG
    2017, 53(6):  1003-1010.  DOI: 10.13209/j.0479-8023.2017.081
    Asbtract ( )   HTML ( )   PDF (1232KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Aimed to strong nonlinearity on high-maneuvering state and huge Doppler frequency shift of satellite communication, unscented Kalman Filter algorithm was proposed to estimate Doppler frequency shift. UKF Doppler frequency shift estimation models in straight and circle motion were built according to the flight feature of hypersonic aircraft, and models were simulated and analyzed. The result indicates that UKF algorithm estimates more precisely of frequency on high-maneuver airborne platform in satellite communication channel model, which proves the stronger practicability of proposed algorithm.

    Geometric Structure and Activities Features of Cangkou Fault in Huangdao
    Jian SONG, Fangtou TANG, Zhihui DENG, Yugui GUO
    2017, 53(6):  1011-1020.  DOI: 10.13209/j.0479-8023.2017.051
    Asbtract ( )   HTML ( )   PDF (159972KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Based on the geological survey, trench excavation, drilling exploration and geological dating methods, detailed analysis and comprehensive research were carried on Cangkou fault in Huangdao. Results show that Cangkou fault distribution in Huangdao bay free trade zone, the Wujiazhuang, Changjiang road subdistrict office, Xinzhuang, Gaojiatai, Zhangjiazhuang, Xiaowa, Baiguo village, and into the Yellow Sea near Xinjian village. In Huangdao, Cangkou fault direction is north-east, and tendency is north-west. The length is about 15 km. The width of the fault zone is between 5 and 35 m. Cangkou fault is mainly developed in the Yanshan period granite. The cretaceous strata, modern geomorphology and quaternary deposits are controlled by Cangkou fault. Since the middle Pleistocene, the main movement is right lateral strike slip with thrust movement after multi period movement. The fault zone is interrupted by the fault mud. Bedrock near fault zone is broken. For security reasons, the authors suggest considering 14 m width as the safety distance of the Cangkou fault in Huangdao. The research of the spatial distribution and the present activity of Cangkou fault in Huangdao has important significance to the reasonable planning, comprehensive development and utilization of land, the seismic geological disaster assess-ment of engineering in the future.

    Research of Permeability Numerical Prediction and Upscaling Based on Micro-CT Computed Tomography of Sandstone Core Sample
    Yuyang LIU, Mao PAN, Chi ZHANG, Xi CHEN, Zhaoliang LI
    2017, 53(6):  1021-1030.  DOI: 10.13209/j.0479-8023.2017.054
    Asbtract ( )   HTML ( )   PDF (8252KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Digital core analysis based on micro-CT computed tomography provide a new approach in core samples’ permeability numerical prediction. Firstly, Minkowski functionals is applied along with the K-means cluster analysis to separate the sandstone core sample gotten from the micro-CT computed tomography into distinct classes, well-sorted fine grain, well-sorted large grain and transition area in order to get the elaborate layer system. Secondly, capillary drainage transform is performed to simulate the distribution of wetting and non-wetting phases under different drainage pressures. Lastly, LBM method is operated based on the core layer system to model permeability of each layers and upscaling is applied based on the simulated results with 3 different ways: directly applying the average method on the prediction values, finding the correlation function of permeability and porosity with and without thin layers in order to get the upscaling values of permeability and correlation function of permeability and porosity.

    The Quantitative Prediction of Ultrasonic Compressive Wave Velocity Dispersion for Fluid Saturated Reservoir Sandstone
    Zhao LIU, Tao HE, Zhiqiang YANG, Changchun ZOU, Keying REN
    2017, 53(6):  1031-1041.  DOI: 10.13209/j.0479-8023.2017.053
    Asbtract ( )   HTML ( )   PDF (1123KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Due to the velocity dispersion error, the laboratory ultrasonic velocity measurement of core samples cannot be directly used to calibrate the acoustic well logging velocity of reservoir in Southwest Weizhou depression. The further work of data processing and analysis for the ultrasonic velocity dispersion were conducted for 5 representative sandstone samples of W3 reservoir. By comparing the compressive velocities of sandstone samples saturated with the brine and four oils of different densities, the method and process of velocity dispersion mechanism analysis were greatly improved. The assumption was proposed and verified that the modulus of non-relaxation wet solid frame was equivalent with the one of dry frame under high pressure condition when the sandstone samples were ruled by squirt flow mechanism. The estimation method of R value, which was the critical squirt length of BISQ theory, was also proposed and verified. Then, the method to quantitatively predict the P-wave velocity dispersion of W3 reservoir sandstones in full waveband was accomplished. Finally it is concluded that the mechanism and degree of velocity dispersion depend on both the physical properties (porosity and permeability) of samples and the kinematic viscosity of pore fluids. Using the velocity dispersion prediction formula for full waveband, the ultrasonic velocity measured in laboratory (high frequency band) can be corrected to different frequency, and then meet the demands of rock physics analysis for well logging (medium frequency band) and exploration seismology (low frequency band). Thus, the complete technique for velocity dispersion analysis and prediction has certain practical meaning.

    Changes of Marine Aerosol Properties over the South Yellow Sea Using Single Particle Aerosol Mass Spectrometer
    Xiaoshuang GUO, Xiaoying LI, Caiqing YAN, Huaiyu FU, Huiwang GAO, Xiaohong YAO, Zhigang GUO, Mei ZHENG
    2017, 53(6):  1042-1052.  DOI: 10.13209/j.0479-8023.2017.121
    Asbtract ( )   HTML ( )   PDF (3459KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To better understand the variation properties of marine aerosol during transport, single particle aerosol mass spectrometer (SPAMS) was applied for the first time during a comprehensive ocean experiment over the South Yellow Sea in November 2012. Two parallel sections influenced by marine air masses with constant wind direction from ocean to land (Section 1), and continental air masses with constant wind direction from land to ocean (Section 2), respectively, were selected to study the variation of chemical characteristics of marine aerosol. The results showed that the average particle count in Section 2 was around 3.5 times higher than that in Section 1, which might be ascribed to the influence of continental air masses, accompanied with high wind speed in Section 2. Particle counts of major components (SO42-, NO3-, NH4+, OC and EC) containing particles in Section 1 and Section 2 (excluding NO3-) gradually decreased by 58%-74% and 34%-53%, and the reductions in Section 1 were greater than that in Section 2. Secondary aerosol contributed to the highest fraction (42%) of the total particles in Section 2, while sea-salt aerosol contributed to the highest (>30%) in Section 1. The contribution of secondary and other anthropogenic aerosols (including biomass burning, Soot-like and Pb-containing aerosols) in both sections were significant. It indicated that the contribution of anthropogenic air pollutants to marine aerosol could not be ignored over the South Yellow Sea.

    Variation of Metal Production, Regional and Industrial Distributions of Heavy Metals Discharge from Industrial Wastewaters of China and European Union
    Menglin LI, Lili WEN, Conghe WANG, Ling HAN, Weiling SUN
    2017, 53(6):  1053-1067.  DOI: 10.13209/j.0479-8023.2017.119
    Asbtract ( )   HTML ( )   PDF (2574KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Based on the data collected from the British Geological Survey, European Pollutant Release and Transfer Register, China Statistical Yearbook on Environment, and Annual Statistic Report on Environment in China, the variations of metal production, regional and industrial distributions of heavy metals discharge from industrial wastewater were compared for China and European Union. Although the metal production increased quickly from 1993 to 2014, the total discharge of heavy metals in wastewaters decreased. This is ascribed to the change in production modes, technology innovation, and improvement of wastewater discharge standard. The regional and industry distributions of heavy metals in wastewaters were different for different heavy metals. Whereas, the regional and industrial distributions of heavy metal discharges from industrial wastewaters of European Union change insignificantly from 2007 to 2013. Moreover, the European Union’s experience in policy formulation and supervision will help China learn from it.

    Study of Marine Pollution Impact on the Habitat Selection of Indo-Pacific Humpback Dolphins
    Mei CHEN, Yuqin SONG, Dakong QIN, Qian ZHU, Chongxiao WEI
    2017, 53(6):  1068-1080.  DOI: 10.13209/j.0479-8023.2017.115
    Asbtract ( )   HTML ( )   PDF (4212KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To explore impact on marine habitats caused by coastal pollution, predictive models of the Indo-Pacific humpback dolphin (Sousa chinensis) distribution were generated using the Maxent modelling approach, based on dolphin occurrence data in Sanniang Bay and its adjacent waters in Guangxi Province during 2006-2007, the independent oceanographic parameters derived from Google Earth Digital Elevation Model (DEM) and Landsat images, and the water environmental data from the marine investigation in 2012. Results indicated that the distance to the major river mouths was the strongest predictors, and water nutrition and persistent pollutants were the important factors for the dolphin distribution in both wet and dry seasons. Based on the results, habitat selection strategies of the dolphin were discussed: the dolphin tended to select estuaries with abundant prey and avoid highly polluted areas, which could be useful in designing Marine Protected Areas (MPAs) and formulating management strategies.

    Allometric Relationship between Tree Height and Diameter of Larch Forests in China
    Chunyun LIU, Wenjing FANG, Qiong CAI, Suhui MA, Xingxing JIANG, Chengjun JI, Jingyun FANG
    2017, 53(6):  1081-1088.  DOI: 10.13209/j.0479-8023.2017.127
    Asbtract ( )   HTML ( )   PDF (4553KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    184 plots from larch (Larix Mill.) forests across China were sampled to characterize the height-diameter relationships and investigate the effects of structure and climate on them based on the power function H = aDb. The results showed that the height-diameter relationship differed greatly among species: b-value of Larix gmelinii (0.65±0.11) and L. olgensis (0.68±0.10) were significantly higher than L. mastersiana (0.51±0.17) and L. potaninii (0.54±0.15) (F=2.34, P=0.026). These differences were significantly influenced by mean annual temperature, but no statistic relationships were detected between stem density, total basal area and mean annual prepetition against b-value. These results indicated that as mean annual temperature increased, a higher proportion of biomass was allocated into diameter growth than height growth (R2=0.09, P<0.001).

    Spatial-temporal Pattern and Causes for GDP per Capita at County Level in Beijing-Tianjin-Hebei Region
    Xiumei TANG, Yunbing GAO, Yu LIU, Chao SUN
    2017, 53(6):  1089-1098.  DOI: 10.13209/j.0479-8023.2017.128
    Asbtract ( )   HTML ( )   PDF (5427KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Taking 171 counties of Beijing-Tiajin-Hebei Region as research units, based on spatial analysis model of GIS and geographic weighted regression model, the spatial-temporal characteristics of GDP per capita and its cause in 1993- 2013 were revealed. Results were as follows. GDP per capita in the Beijing-Tianjin-Hebei Region at county level showed rapid growth trend with expanding difference; GDP per capita at county level showed a significant positive correlation, that is to say, the pattern of high-high concentration and low-low concentration was enhanced. Beijing-Tianjin-Tangshan Region was always the hot economic development zone in Beijing-Tianjin-Hebei Region, the GDP per capita of most counties in Hebei Province was at low level, and cold economic development belt of “Laiyuan County-Gaoyang County-Wuyi County-Zaoqiang Qiu County” was gradually formed. GDP per capita at county level showed spatial pattern of “northeast-southwest”, and the overall trend was enhanced. Wen’an County was the core of GDP per capita gravity, and the centre of economic gravity moved southwest firstly and then northeast, indicating that the economic development function in the northeast of Beijing-Tianjin-Hebei Region further strengthen. Compared with OLS model, the fitting effect of GWR model was improved obviously. The development of GDP per capita in 2013 was mainly promoted by the gross industrial output value per capita, the proportion of value-added of the tertiary industry, the contracted investment actually utilized per capita and urbanization level.

    Analysis of Vulnerable Characteristics in Chinese Northern Farming-Pastoral Region Based on Coordinated Regional Downscaling Experiment
    Yimin ZHOU, Ang ZHANG, Xinyi ZHAO
    2017, 53(6):  1099-1107.  DOI: 10.13209/j.0479-8023.2017.123
    Asbtract ( )   HTML ( )   PDF (3113KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Based on the grid data set of temperature and precipitation of China (0.5°×0.5°) and the output of coordinated regional downscaling experiment (CORDEX) East Asia, including the climate prediction based on RCP4.5 and RCP 8.5, the authors simulate and analyze vulnerability in Chinese northern farming-pastoral region from 1980 to 2100 with temperature, precipitation and maximum near-surface wind speed. The results show that the ecologically vulnerability in Chinese northern farming-pastoral region increases during 2006-2100, especially after 2050, the increase speed rises rapidly. By the end of 21st century, almost all the Chinese northern farming-pastoral region shows at least obvious vulnerability. Said on the space, the vulnerability is severe from Zhongwei to north of Hohhot, however, it’s better in north Great Khingan.

    Preparation of Magnetic Excess Sludge and Removal of Phosphate
    Huchun TAO, Xiao ZHANG, Jinbo LI, Shuaibin HUANG, Biao MA
    2017, 53(6):  1108-1114.  DOI: 10.13209/j.0479-8023.2017.107
    Asbtract ( )   HTML ( )   PDF (2082KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    MNPs were prepared using coprecipitation method, with FeCl3, FeCl2 and ammonia. MNPs were compounded with excess sludge (moisture content of 99%) to prepare magnetic excess sludge (MES). Alternating gradient magnetometer was used to measure the magnetic response of MES and scanning electron microscope (SEM) to observe morphology of excess sludge and MES. After magnetic separation, the water content of MES was calculated to investigate the degree of sludge thickening. The adsorption property of total phosphorus onto MES was investigated. According to the results, MES had superparamagnetism, and its saturation magnetization was 42 emu/g. Within 30 s it could be separated from liquid. The optimal conditions for adsorption of total phosphorus on MES were the initial pH value of solution ranging in 4-6, an initial concentration of phosphorus solution of 16 mg/L (calculated as P), adsorption equilibrium was achieved within 600 min. The kinetics data were fitted well with the pseudo-second order model. The adsorption fitted the Langmuir isotherm well with the equilibrium data and the theoretical maximum adsorption capacity was 3.00 mg/g (calculated as P). MES could accelerate the separation of sludge and wastewater, and the volume of excess sludge was reduced largely. The adsorption performance of total phosphorus on MES was better than that on excess sludge. The study provided a new handling method of excess sludge for sewage treatment plant whose secondary treatment process was activated sludge process.

    Screening of Alginate Degrading Bacteria and Optimization of Its Enzyme-Producing Conditions
    Tingting LI, Qian CHEN, Ping SHI, Shu GENG
    2017, 53(6):  1115-1121.  DOI: 10.13209/j.0479-8023.2017.122
    Asbtract ( )   HTML ( )   PDF (812KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    53#, a strain of efficient alginate degrading bacteria, is isolated from rotted kelp using sodium alginate as the only carbon resource. Strain 53# is identified as Paenibacillus agaridevorans based on physiological characteristics and 16S rRNA sequencing. The optimaltion yield condition of strain 53# is identified at pH=8, T=25ºC, NaCl 15 g/L, and sodium alginate 15 g/L by orthogonal experiment and analysis, and the highest enzyme activity is 390.53±17.32 U/mL. Strain 53# has the advantages such as being cultivated easily, producing enzyme fast and having high enzyme activity. It can achieve a high efficiency for saccharification of alginate and thus has potential value to be utilized in the production of bioethanol from brown algae.

    Single and Competitive Adsorption of Cu(Ⅱ), Pb(Ⅱ), Ni(Ⅱ) and Cd(Ⅱ) onto Biochar
    Qi WANG, Binwei WANG, Guangcai TAN, Nan XU
    2017, 53(6):  1122-1131.  DOI: 10.13209/j.0479-8023.2017.130
    Asbtract ( )   HTML ( )   PDF (5539KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Two kinds of materials including corn stalks and diary manure were used to produce the biochars (BC and DMBC) by pyrolysing at temperature of 500ºC under the protection of nitrogen atmosphere. The single and competitive adsorption characteristics of Cu2+, Pb2+, Ni2+ and Cd2+ ions onto these biochars were investigated to reveal the interaction among the metal ions on the biochar. Experimental results show that the biochars have different elemental composition. BC has a larger specific surface area, and DMBC has a bigger average pore diameter. For the single metal adsorption, the kinetics on BC are similar, but obvious differences of adsorption rates were observed on DMBC. Langmuir isotherm model well fits the sorption data of the four metal ions, and the order of sorption capacity is Pb2+>Cu2+>Cd2+>Ni2+. Through the competitive adsorption experiments it is found that the competitive sorption capacity of Pb2+ is the strongest, and Cu2+ follows, while the sorption of Ni2+ and Cd2+ are weaker and easy to be suppressed by other divalent metal ions.

    Valuation of Rangeland Ecosystem Services from the “Herder-Grass-Livestock” Social Ecological System Perspective: a Case Study in Guinan County, Hainan Tibetan Autonomous Prefecture, Qinghai
    Haoyi WU, Wenjun LI, Minghao ZHUANG, Gongbuzeren
    2017, 53(6):  1133-1142.  DOI: 10.13209/j.0479-8023.2017.125
    Asbtract ( )   HTML ( )   PDF (474KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Rangeland ecosystem has unique characteristics as it provides home to both extensive livestock production and thousands of herders. Thus, valuating rangeland ecosystem needs to consider the co-evolved system of grass, livestock and herders. Based on case study from Guinan County, Hainan Tibetan Autonomous Prefecture, Qinghai with semi-structured interview, field sampling and multi-stakeholder interview, the study valuates the rangeland ecosystem from a complete ecosystem perspective-“Herder-Grass-Livestock” perspective. This paper first applies a step-by-step analyzing method from “soil-grass”, “grass-livestock”, to “herder-grass-livestock” level to identify services provided by rangeland ecosystem. Based on this, the study valuates the rangeland ecosystem services in monetary value. The results show that the value of rangeland ecosystem services in the research area is 20 times higher than the one calculated by the government. The ecological value, livelihood supporting value and social value of rangeland ecosystem are much higher than economic value of livestock trading, and these important values have been neglected in the governmental statistical system. Even the valuation is limited to the value of extensive animal husbandry, it is still 1.6 times higher than the values developed by government. Therefore, as government highly promotes the establishment of the green national economy accounting system, the government needs to improve its original statistical system to encompass the whole value of rangeland ecosystem, and apply this newly calculated value as bases for ecological compensation.

    Effects of Nitrogen Addition on the Radial Growth of Castanopsis carlesii in Wuyi Mountain
    Xinyang ZHANG, Qiaoshuyi WANG, Juan XING, Faxu ZENG, Fuqing FANG, Chengyang ZHENG
    2017, 53(6):  1143-1149.  DOI: 10.13209/j.0479-8023.2017.126
    Asbtract ( )   HTML ( )   PDF (829KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The authors carried out a N enrichment experiment in Wuyi Mountain with four N addition levels (control (0), low N (50 kg N/(hm2·a)), medium N (100 kg N/(hm2·a)) and high N (150 kg N/(hm2·a))) This study was designed to study the seasonal characteristics of DBH (diameter at breast height) growth of Castanopsis carlesii and its short term response to simulated nitrogen deposition. Results show that the Castanopsis carlesii annual growth can be divided into 3 periods: water recovery period, fast growth period and slow growth period. N additions play different roles on the growth of Castanopsis carlesii. In the fast growth period (June to October), low N and medium N significantly increase the relative growth rate of annual DBH. Relative DBH growth in slow growth period (November to April) has no significant response to N addition. Among different diameter classes, N additions affect the DBH growth differently: low and medium N additions significantly promote growth in low diameter class (5 cm<DBH<15 cm) (p<0.05), but the tree growth has no significant response to high N addition. With the increase of tree diameter, the DBH growth of Castanopsis carlesii decreases sensitivity to N additions. High diameter class (DBH>25 cm) does not show significant response to N deposition. The study also finds that medium N addition significantly increase the biomass growth rate of Castanopsis carlesii in the study area (p<0.05).

    Temporal and Spatial Variation of the Water Quality and the Sediment Bacterial Community in Weiming Lake, Peking University
    Yile TAO, Chenfeng ZHANG, Lin XU, Donghui WEN
    2017, 53(6):  1150-1160.  DOI: 10.13209/j.0479-8023.2017.131
    Asbtract ( )   HTML ( )   PDF (5601KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Eutrophication has been one of threats to the aquatic environment nowadays. Learning the water quality and analyzing the possibility of eutrophication of Weiming Lake, an irreplaceable symbol of Peking University, is the scientific basis to improve the water quality and a reference to the protection of other artificial lakes. Hardly disturbed by anthropogenic activities, the water quality of Weiming Lake was good in nitrogen related indexes, but the indexes of COD, TP, and DO were at or even worse than Level V water quality in all the regions and seasons. The average TLI indexes of Weiming Lake was 56.1, slightly eutrophication. PCR-DGGE analysis showed the diversity of sediment bacterial community varied through seasons, higher in spring and summer, highly related with the location and the weight of nutrients in summer and autumn. Linear regression showed that the activities of algae may influence the sediment bacterial community through nitrogen fixation.

    Isolation of Fungal Strains in Soil of Selenium Mining Area and Screening for Their Anti-tumor Activity
    Xiling RAN, Yu LIU, Congkui TIAN, Tingting ZHU, Yanan SONG, Yuexian MO
    2017, 53(6):  1161-1164.  DOI: 10.13209/j.0479-8023.2017.077
    Asbtract ( )   HTML ( )   PDF (3490KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The fungal strains were obtained by single colony isolation technique from the soil of the world’s unique proved independent selenium deposit. The anti-tumor activity was assayed by MTT method using MDA-MB-231cells, Hela cells and SMMC-7721 cells, respectively, together with morphological observation of these cells under inversed light microscope. The 73 terrestrial fungal strains were isolated from the soil samples collected from 6 different areas in Enshi area of HuBei Province, China. Among them, 32 strains produced fermentation products obviously inhibiting the Hela cells, 13 strains inhibiting the MDA-MB-231 cells and 9 strains inhibiting the SMMC-7721 cells with IC50 value less than 90 µg/ml. These antitumor-metabolite-producing strains have provided fungal strains for further studies on the bioactive metabolites.

    Review on Methods of 3D Reconstruction from UAV Image Sequences
    Lei LIU, Min SUN, Xiang REN, Xinfu LIU, Liang LIU, Hui ZHENG, Xiaodong LI
    2017, 53(6):  1165-1178.  DOI: 10.13209/j.0479-8023.2017.052
    Asbtract ( )   PDF (567KB) ( )  
    References | Related Articles | Metrics

    Based on reviewing the methods for UAV image-sequence reconstruction, the classification on the principle and applicability of the methods is proposed. Generally, the methods involved can be divided into two groups. One is based on traditional photogrammetry, which needs more intermediate quality-control checks and more human-computer interactions. This method can be used to reconstruct large and regular image blocks. The other called the multi-view geometry method, is more like close range photogrammetry. It is more suitable for automatic reconstruction of irregular image blocks, such as specific objects and complex terrains. After comparing applicability of different methods, the related technology is expatiated, and the advantages, limitations and enhancement methods are discussed. Finally, it is pointed out that the combination of photogrammetry and computer vision is the future research direction, and the key problems to be solved are discussed.