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Table of Content

    20 March 2018, Volume 54 Issue 2
    A Hybrid Optimization Framework Fusing Word- and Sentence-Level Information for Extractive Summarization
    LIN Xinyi, YAN Rui, ZHAO Dongyan
    2018, 54(2):  229-235.  DOI: 10.13209/j.0479-8023.2017.148
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    In order to fuse word-level and sentence-level information from different semantic spaces, the authors propose a hybrid optimization framework to optimize word-level information while simultaneously incorporate sentence-level information as constraints. The optimization is conducted by iterative unit substitutions. The performance on DUC benchmark datasets demonstrates the effectiveness of proposed framework in terms of ROUGE evaluation.

    Regular Path Queries on Large Graph Data
    ZHANG Yu, ZENG Li, ZOU Lei
    2018, 54(2):  236-242.  DOI: 10.13209/j.0479-8023.2017.151
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    The authors propose a divide-and-conquer based solution over gStore, an existing RDF search engine, to process property path query on large scale graph data. In proposed solution, regular expression is partitioned within the path query and then preprocess strings of fixed length. The authors handle the search over those subqueries of wildcards. The proposed method is able to filter lots of unpromising search and efficient on solving the regular path match problem over large scale graph data. The corresponding experiments on DBpedia and LUBM confirm that proposed method can response for queries in seconds on average.

    A Study of Articulatory Features Based Detection of Mandrain Pronunciation Erroneous Tendency for Automatic Annotation
    WEI Xing, WANG Wei, CHEN Jingping, XIE Yanlu, ZHANG Jinsong
    2018, 54(2):  243-248.  DOI: 10.13209/j.0479-8023.2017.152
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    For the purpose of relieving the time cost and inconformity in annotation, the authors use an articulatory features based mispronunciation detection system to give an Top-N feedback and use this feedback to assist manual annotation. As a result, the consistency rate of phoneme labels in proposed system increases from 80.7% to 92.48%. In addition, the time cost for annotating each sentence reduce from 10 to 3 minutes. The results indicate that proposed automatic annotation system is practical, and there is also a room for further improvement.

    Study on Continuous Speech Recognition Based on Bottleneck Features for Lhasa-Tibetan Dialect
    ZHOU Nan, ZHAO Yue, LI Yaoqiang, XU Xiaona, CAIWANG Lamu, WU Licheng
    2018, 54(2):  249-254.  DOI: 10.13209/j.0479-8023.2017.154
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    The bottleneck features extracted from deep neural network not only have long term contextdependence and compact representation of speech signal, but also can replace the traditional MFCC features for GMM-HMM acoustic modeling. The authors apply bottleneck features and their concatenated features with MFCC into Lhasa-Tibetan continuous speech recognition. The experiments in Lhasa-Tibetan continuous speech recognition show that the concatenated features of bottleneck features and MFCC achieve better performance than the posterior features of deep neural network and mono-bottleneck features.

    Neural Post-Editing Based on Machine Translation Quality Estimation
    TAN Yiming, WANG Mingwen, LI Maoxi
    2018, 54(2):  255-261.  DOI: 10.13209/j.0479-8023.2017.153
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    In order to solve the problem of overcorrection in automatic post-editing translations, the authors propose to make advantage of the neural post-editing (NPE) to build two special models: one is used to provide minor edit operations, the other is used to provide single edit operation, and make advantage of machine translation quality estimation to establish a filtering algorithm to integrate the special models with the regular NPE model into a jointed model. Experimental results on the test set of WMT16 APE shared task show that the proposed approach statistically outperforms the baseline. Deep analysis further confirms that proposed approach can bring considerable relief from the over-editing problem in APE.

    Domain Term Extraction Using URL-Key
    Lü Shuning, DONG Zhian
    2018, 54(2):  262-270.  DOI: 10.13209/j.0479-8023.2017.157
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    A new approach was presented for domain term extraction using URL-Key. With the help of known URL-Key’s domain, unknown URL-Key’s domain can be identified. First, according to the frequency of URL-Key appearing in various fields, a method based on the variance was proposed to identify the domain URL-Key and build the dictionary of domain URL-Key. Then, the pseudo related feedback was used to construct the URL-Key vector of candidate domain terms. Finally, SVM was applied to extract terms. Experiment was conducted on four different domains for Chinese term extraction. Experimental results indicate that the proposed method is quiet effective. In addition, it can effectively solve the recognition problem of low frequency terms, and provides a new way for the identification of low frequency terms.

    Research on Automatic Writing of Football Game News
    WANG Wenchao, Lü Xueqiang, ZHANG Kai, ZHOU Jianshe
    2018, 54(2):  271-278.  DOI: 10.13209/j.0479-8023.2017.156
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    After analyzing the characteristics of different types of sports events, the authors propose an automatic writing method for football tournament with real-time data as data source for the first time. The real-time data is automatically annotated according to historical news, and the training set is obtained. After annotation the real-time data is modeled by convolution neural network (CNN) to automatically identify the key events in real-time data. Events in structured information are transformed into news style natural language. Experiments show that the proposed method works better than other methods, and the content is more detailed and can be easily extended to the automatic writing of other sports games.

    Training Machine Translation Quality Estimation Model Based on Pseudo Data
    WU Huanqin, ZHANG Hongyang, LI Jingmei, ZHU Junguo, YANG Muyun, LI Sheng
    2018, 54(2):  279-285.  DOI: 10.13209/j.0479-8023.2017.158
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    Aimed at providing efficient training data for neural translation quality estimation model, a pseudo data construction method for target dataset is proposed, the model is trained by two stage model training method: pre training based on pseudo data and fine tuning. The experimental design of different pseudo data scale is carried out. The experiment results show that the machine translation quality estimation model trained by the pseudo data has significantly improved in the correlation between the scores given by human and the artificial scores.

    LSTM Based Question Answering for Large Scale Knowledge Base
    ZHOU Botong, SUN Chengjie, LIN Lei, LIU Bingquan
    2018, 54(2):  286-292.  DOI: 10.13209/j.0479-8023.2017.155
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    To solve the specific problem in KBQA, a question answering system is built based on large scale Chinese knowledge base. This system consists of three main steps: recognition of named entity in question, mapping from question to property in KB, and answering selection. Alias dictionary and LSTM language model are used to recognize named entity contained in question, and two different attention mechanisms are combined with bidirectional LSTM for question-property mapping. Finally, exploit results of first two steps are exploited for entity disambiguation and answering selection. The average F1 value of proposed system in NLPCC-ICCPOL 2016 KBQA task is 0.8106, which is competitive with the best result.

    An Analysis Method of System-Level ESD Model with a TLP Stress Input
    WANG Yize, WANG Yuan, CAO Jian, ZHANG Xing
    2018, 54(2):  293-298.  DOI: 10.13209/j.0479-8023.2017.146
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    Based on the existing equivalent formula of the transmission line pulse (TLP) and IEC 61000-4-2 stresses, the authors propose an analysis method of the system-level model with TLP stress as an input. Compared with the traditional analysis method under system-level IEC stress, the proposed method solves the issue that the calculation of the residual energy flowing into the device under test (DUT) is not accurate enough. Meanwhile, the prediction ability for the failure of the DUT is promoted. This work predicts the failure of the DUT under the mentioned two stresses through SPICE simulation. Furthermore, this work shows the validation through the measured results of the relevant printed circuit boards (PCBs), which confirms the promotion of the aforesaid prediction ability.

    Design of a High Speed Low Power Time-to-Digital Converter Based on Multi-stage Amplification Structure
    FAN Chuanqi, JIA Song, WANG Zhenyu, YAN Wei, WU Zebo
    2018, 54(2):  299-306.  DOI: 10.13209/j.0479-8023.2017.145
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    The authors present a time-to-digital converter based on multi-stage amplification structure. This structure consists of coarse stage and fine stage. Coarse stage utilizes delay line to get the residue which is less than a buffer’s delay. A small area and low power residue selecting logic is designed. In the fine stage, 2× time amplifier and half judger is utilized to generate 4 binary codes from MSB to LSB. Simulation in SMIC 65 nm process shows that the new structure has a high conversion speed up to 470 MS/s and power consumption is 1.3 mW at 100 MHz with the resolution of 1.44 ps and range of 736 ps. An accurate gain robust to PVT variation can be achieved with the calibration of the time amplifier, so a good integral nonlinearity is obtained.

    An ICA Based Method for Grid Radio Signal Monitoring
    ZHANG Jingshu, Lü Mengfei, LI Dou, YANG Yanjun, ZHAO Yuping
    2018, 54(2):  307-314.  DOI: 10.13209/j.0479-8023.2017.173
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    An independent component analysis (ICA) based method is designed for improving the effect of grid radio monitoring and providing an effective layout of the monitoring system, in which the source signals can be retrieved and sudden emergence of abnormal signal sources can be detected. To analyze the multiple factors affecting the performance of the method, a MATLAB simulation modeling is built. The feasibility and efficiency of the proposed ICA based method are also demonstrated.

    Low Resource Consumption Design of Digital Decimation Filter
    QIAN Zebin, YAN Wei
    2018, 54(2):  315-319.  DOI: 10.13209/j.0479-8023.2017.140
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    A digital decimation filter applied to audio Sigma-Delta ADC is designed. The filter adopts the design of multi-stage and multi-rate down sampling structure, in-band ripple of decimation filter is less than 0.06 dB overall, bandwidth is 21.6 kHz, minimum working frequency is 10 MHz. Through the innovation of filter hardware architecture design, it effectively reduces the filter circuit area and power consumption. Chip test results show that the SNR is above 87.2 dB when processing PDM signals is at the down sampling rate of 64, 4 order Sigma-Delta modulation. Designed in SMIC’s 0.13 μm CMOS process, the decimation filter area is 0.146 mm2. Filter area is reduced by 58%, and power consumption is reduced by over 60% compared with the same type decimation filters.

    Cross Site Script Prevention Based on Delimiters
    ZHANG Huilin, LI Guancheng, DING Yu, DUAN Lei, HAN Xinhui, XIAO Jianguo
    2018, 54(2):  320-330.  DOI: 10.13209/j.0479-8023.2017.172
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    The authors propose a practical and accurate cross site script prevention method based on delimiters for UTF-8 encoded web applications. Only trusted delimiters are tainted into corresponding UTF-8 shadow bytes, and these tainted shadow bytes are automatically propagated in web applications and can be directly delivered into output pages. Cross site script is prevented by analyzing the tainted delimiters and HTML context of output pages. A prototype called XSSCleaner is implemented on PHP. The evaluation shows that XSSCleaner can accurately protect web applications from real world cross site script attacks with an average overhead 12.9%.

    Research on Continuity of Multi-Scale Space-Filling Curves
    ZHAI Weixin, CHEN Bo, TONG Xiaochong, CHENG Chengqi
    2018, 54(2):  331-335.  DOI: 10.13209/j.0479-8023.2017.147
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    Multi-scale two-dimensional Hilbert curve is constructed, and specially the scale dimension is treated as the third dimension. The new structure embodies the multi-level characteristics and overcomes the drawback of Z sequence coding pattern, thus improving the continuity of the curve and advancing the spatial retrieval efficiency. The authors conducted two kinds of experiments based on the quad-tree model to compare the retrieval efficiency of Hilbert curve and Z curve. The consequence indicates that the multi-scale Hilbert curve performs better than Z curve, and the improvement on different data distributions vary from 15% to 30%.

    Disparity Estimation Method for Free-Texture Scenes Based on Light Field
    ZHENG Miao, ZHAO Hongying, YANG Peng, YAN Lei, ZHENG Hongyun, CUI Jialiang
    2018, 54(2):  336-340.  DOI: 10.13209/j.0479-8023.2017.116
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    In order to improve the pixel distinguishability, this paper introduces an algorithm that the quantized geometric relationship among sub images of light field replaced the pixel value. Based on this relationship, the epipolar line division ratio is calculated to take place of pixel value. Experimental results showed that the disparity map with the division ratio images are obviously superior to those obtained by using the subaperture images.

    Long-term Mean Footprint and Its Relationship to Heavy Air Pollution Episodes in Beijing
    ZOU Qingqing, CAI Xuhui, GUO Mengting, SONG Yu, ZHANG Xiaoling
    2018, 54(2):  341-349.  DOI: 10.13209/j.0479-8023.2017.134
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    Potential source area (footprint) related to air pollution of Beijing is investigated. Long-term modeling of meteorological fields is carried out by WRF model, from 2000 to 2014. A backward dispersion footprint model is used to derive hourly footprint using these meteorological data. Long-term mean source area is obtained as well as its seasonal variation. Heavy air pollution episodes in winter and autumn are selected from air pollution index (API) data in the period from 2000 to 2012. Relationship between air pollution and its potential source area is discussed. Results show that daily mean footprint varies both by its pattern and direction, indicating strong temporal variation of the source areas for Beijing. Long-term mean source area for Beijing is shaped like a triangle, and the southwest branch is the strongest, the other two are in the east and north. Beijing locates in the middle to norther position of the triangle. Seasonal variation of the mean source area show enhancement in the southwest and south in summer (July) and autumn (October). Local wind frequency may mislead assessment of source area, in comparison to the footprint derived by the backward dispersion model. By handling all dispersion processes, such as accumulation of air borne materials, the footprint model provides reasonable information of source area. Mean footprint of all heavy air pollution episodes reveals that a wide arc zone in front of the mountains is the most significant source area to air pollution of Beijing. This zone starts approximately from Shijiazhuang in the southwest to Beijing, and then turning to Tangshan in the east.

    Effects of Atmosphere on Radiative Transfer Characteristics and Salinity Retrieval on Spaceborne Salinity Meter
    WANG Yingqiang, YAN Wei, WANG Yeying, HAN Yueqi
    2018, 54(2):  350-360.  DOI: 10.13209/j.0479-8023.2017.162
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    Using the MPM93 model, the L-band of atmospheric radiation parameters and salinity meter observation brightness temperature under different weather conditions are numerically simulated based on the microwave radiation transfer equation, and using the maximum likelihood estimation algorithm to the inversion of sea surface salinity, which research the influence of different weather conditions on the sea surface salinity retrieval value. The simulation results show that the atmospheric radiation parameters of cloud, fog and haze which considered the effects of suspended droplets are almost the same as those in clear sky, and the influence of them can be neglected. However, the influence of rainfall on atmospheric radiation parameters can’t be neglected, and the error of salinity retrieval increases obviously with the increase of rainfall rate. When the rainfall rate is fixed, the salinity inversion error decreases with the increase of sea surface temperature, and the salinity retrieval error is smaller under low salinity value. Besides, the salinity retrieval error changes decrease after increasing with the increase of sea level atmosphere temperature. Furthermore, the influence of sea surface windspeed, sea level pressure and sea level vapor density on salinity retrieval error are very small.

    Automatic Microseismic Event Detection and Arrival Picking Based on Waveform Cross-Correlation
    WEI Mengyi, TAN Yuyang, MAO Zhonghua, FENG Gang, HU Tianyue, HE Chuan
    2018, 54(2):  361-372.  DOI: 10.13209/j.0479-8023.2017.079
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    Generally, a cluster of seismic events which share similar source locations and focal mechanisms will show similar waveforms on the record. Based on this assumption, a method have been developed for microseismic event detection and arrival picking based on waveform cross-correlation. This method achieves moveout correction for the seismic records based on cross-correlation functions, then calculates a multi-channel semblance coefficient to identify the microseismic events. Meanwhile, the seismic records after moveout correction are superposed. The STA/LTA method is adopt to pick the arrivals for the stacked traces, the arrival times of the microseismic events are then automatically obtained. The performance of the method is evaluated using both synthetic and real datasets. Analysis of the results demonstrates that the proposed method can not only detect the microseismic events, but also obtain relatively accurate arrival picks at the same time.

    Diagenesis Types and Evolution of the Lower-Middle Ordovician Carbonates in Yubei Area, Tarim Basin
    LIU Hongguang, LIU Bo, ZHANG Xuefeng, CAO Jianhua, HUANG Chenjun, LIU Geyun, WU Shuanglin
    2018, 54(2):  373-384.  DOI: 10.13209/j.0479-8023.2017.135
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    The Lower-Middle Ordovician carbonate rocks are studied by core observation, thin section observation, geochemical analysis to restore the diagenetic evolution history of the Yubei area, Tarim Basin. Dissolution, dolomitization, silicification and cataclasis are studied and the diagenetic evolution history is divided into four stages. The grained texture dominated limestone in the relative geomorphic high location exposes to the ground and undergoes penecontemporaneous dissolution due to the fluctuation of the sea level. Caves and pores with structural selectivity parallel to the sedimentary bed are generated by the penecontemporaneous dissolution. The dolomitization developed mainly in early diagenetic stage enhances the resistance of carbonates to compaction and pressure solution, which benefits the preservation of early pores and caves. The fractures formed during the Middle-Late Caledonian and Early Hercynian in this stage are mostly closed and filled due to complicated compaction and cementation. Hydrothermal activity in middle diagenetic stage damages the reservoir slightly by the presence of pyrite and dolomite with wavy extinction and saddle structure in the reservoir space. The late diagenetic stage is characterized by the silica and calcareous fluid activity, which fill the early space partially. The development degree of fractures formed during Late Hercynian and Himalayan epoch is weaker than early diagenetic stage. However, the fractures formed during late diagenetic stage keep open due to weak diagenetic transformation and become efficient migration channel and reservoir spaces in Yubei area.

    Petrogenesis of Hornblendite Enclaves in Jinling Magmatic Complex of Intrusions from the Western Shandong Province
    HU Yalu, LIU Shuwen, JIN Ziliang, XIE Qiuhong, WEN Bingbing, LI Zixi
    2018, 54(2):  385-397.  DOI: 10.13209/j.0479-8023.2017.149
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    In order to determine the genesis of the hornblendite enclaves in the Jinling magmatic complex of intrusions in the Western Shandong Province, petrological, mineralogical and geochemical analyses have been conducted on the hornblendites from the complex. The hornblendites show clearly cumulus structure and are composed of plagioclases and amphiboles. The amphiboles in hornblendite enclaves can be divided into two types. The first type of amphibole shows lower SiO2 but higher Al2O3 contents and is classified as the pargasite with magmatic genesis. The other type of amphibole is composed of actinolite, magnesiohornblende and edenite with higher SiO2 but lower Al2O3, which may be attributed to modifications of the magmatic amphiboles during later tectonothermal events. The crystallization pressure of hornblendite enclaves is estimated to be 0.48 GPa using the hornblende Al2O3 geobarometer. The hornblendite enclaves show similar characters of the REE and trace elements to those of the hosting dioritic rocks, and are characterized by the LREE enrichment but HREE depletion. Together with the mineral crystalline condition of the magmatic hornblende, it is concluded that the hornblendite enclaves and their hosting diorites in the Jinling magmatic complex of intrusions may be produced by fractionation crystallization of cogenetic magmatic evolution, and the hornblendite enclaves crystalized from a lower magmatic chamber in the middle-crust level.

    Equilibrium Line Altitude Distribution Characteristics and Influencing Factors of Modern Glaciers in Yadong-Kangmar, Himalaya Range
    LIU Junnan, LIU Gengnian, PENG Xu, LIU Beibei, CUI Zhijiu
    2018, 54(2):  398-406.  DOI: 10.13209/j.0479-8023.2017.103
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    The second China glacier inventory results and satellite images, combined with field observation of the landscape, are used to discuss the glacier equilibrium-line altitude (ELA) distribution characteristics and influencing factors of Yadong-Kangmar, Himalaya Range. The result shows that the average of modern glacier ELA of study area is 5717 m, Kuragon District on average is 5840?5957 m, Baima Ling Kangri area is relatively low, 5333?5373 m, reflecting the control of climate and terrain trend to glacier ELAs. In addition, there are varying degrees of effects on glacier ELAs on account of the factors like direction, slope, glacier moraine cover, and avalanche.

    Research of Carrying Capacity on Resource and Environment in Core Cities of Central Henan Urban Agglomeration
    YU Yang, HAN Peng, YANG Nan, LI Xiaolei, GUO Yunhao
    2018, 54(2):  407-414.  DOI: 10.13209/j.0479-8023.2017.160
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    By analyzing the characteristic of urban agglomeration areas, proposing that considering the mobility of resource is essential in researching carrying capacity, the research used core cities of Central Henan urban agglomeration as cases to study, referencing press-state-response model to build the target system of carrying capacity, considering resource supply and consumption & environmental pollution and treatment, using AHP method to evaluate. Reliant exponential is used to evaluate the dependence severity. The result shows that according to the comparison of two results considering resource fluidity or not in Zhengzhou in 2004?2014, only considering resource fluidity can reflect the real condition of an area. Core cities of Central Henan urban agglomeration are short of water and energy resources but are enough to use with the supply of external resources. The orders of the carrying capacity index on resource and environment are Luohe, Xuchang, Xinxiang, Zhengzhou, Jiyuan, Jiaozuo, Luoyang, Pingdingshan and Kaifeng. According to the reliant exponential of external resources, grain resources in these nine cities are self-sufficiency. External energy resources are needed in Kaifeng, Xinxiang, etc. External water resources are needed in Zhengzhou, Kaifeng, etc. More external water resources are needed than external water resources.

    Assessment of Heavy Metals Contamination in Three Kinds of Habitat of Futian Mangrove Forest in Shenzhen Bay
    CHENG Shanshan, SHEN Xiaoxue, CHAI Minwei, LI Ruili
    2018, 54(2):  415-425.  DOI: 10.13209/j.0479-8023.2017.161
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    Taking Futian Mangrove National Nature Reserve as the study area, sediments cores (0–50 cm) were sampled among three kinds of habitat, including fish pond, Avicennia marina forest and mudflat. The spatial distribution features of physicochemical properties and heavy metals in sediment cores were analyzed. The potential ecological risk index of heavy metals was calculated and analyzed. Analysis of physicochemical properties revealed that pH value followed the order: mudflat>Avicennia marina forest>fish pond; electrical conductivity, salinity, and total organic carbon (TOC) followed the order: Avicennia marina forest>mudflat>fish pond. The metal concentrations in sediments decreased in the following order: Zn (103.45–214.14 μg/g), Cu (70.92–133.50 μg/g), Pb (54.90–84.65 μg/g), Cd (6.57–7.25 μg/g). The concentrations of Zn, Cu and Pb followed the order: Avicennia marina forest>mudflat>fish pond and the concentrations of Cd followed the order: Avicennia marina forest≈mudflat>fish pond. The lowest level was located at fish pond (P<0.05). The concentrations of Zn and Cu were extremely different (P<0.05) among different vertical depths. Only the concentration of Cu was significantly affected by the interaction effect of sites and depths (P<0.05). Bivariate correlations results indicated that TOC had a significantly positive correlation with Pb in the fish pond (P<0.05), and the correlation of different kinds of heavy metals were complicated in Avicennia marina forest and mudflat. Different kinds of heavy metals had a significantly positive correlation in the fish pond (P<0.05), indicating that the source of 4 species of heavy metals might be same. In addition, the average contents of Cd, Cu, Zn, and Pb in all sediments of the Futian Mangrove Nature Reserve exceeded the first class of criteria GB 18668-2002.The single potential ecological risk of heavy metals followed the order: Cd>Cu>Pb>Zn and Avicennia marina forest>mudflat>fish pond. The integrated potential ecological risks at sampling sites reached high risk level completely, mainly due to Cd contamination, followed by Cu.

    Object-Oriented Precise Decision-Making (OOPD) for Water Quality Improvementin Lake Yilong
    ZOU Rui, SU Han, YU Yanhong, WANG Junsong, YE Rui, LIU Yong
    2018, 54(2):  426-434.  DOI: 10.13209/j.0479-8023.2017.164
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    A framework called Object-Oriented Precise Decision-making (OOPD) was proposed which oriented to the lake itself. The framework was based on Numerical Source Apportionment powered by 3-dimensional water quality model, which then quantified the causality of water quality improvement and load reduction. The proposed framework was applied to support short-term decision making of Lake Yilong, a eutrophic lake. Results showed that Chenghe sub-watershed and Chengbeihe sub-watershed were important pollution source no matter considering which monitoring station and under which water diversion scenario. In addition, comprehensive pollution control should be considered to ensure that Huzhong monitoring station or Hudong monitoring station meet water quality standards. However, considerable load reduction cannot guarantee water quality if there was no water diversion. Water quality of three monitoring stations would be improved a lot under 20 and 30 million m³ annual water diversion scenario. Finally, based on the analyses above, suggestion of focused pollution control project was given for each sub-watershed and an evaluation of one bean product wastewater treatment extension project was given to illustrate how to combine micro and macro aspects in OOPD.

    Reductive Removal of Four Halogenated Organic Compounds by Different Sizes of Zero-Valent-Iron
    ZHAO Xufei, WEI Caijie, ZHANG Jin, WU Weizhong, WANG Xiaomao, YANG Hongwei, XIE Yuefeng
    2018, 54(2):  435-442.  DOI: 10.13209/j.0479-8023.2017.165
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    Based on the chlorinated organic compounds pollution existed in underground water of China, Zero-Valent-Iron (ZVI) technology is employed for the removal of four representative halogenated organic compounds (HOCs) (tetrachloroethylene, PCE; tricholoroethylene, TCE; tetrachlormethane, TCM; and chloroform, CT). The results indicated that the reduction rates of four target compounds, of which the initial concentration is 400 μg/L, negatively correlated with the size of Zero-Valent-Iron particles. The reduction kinetics of the targeted HOCs were all well fitted with the Pseudo-firstorder kinetics, and the ranking of obtained first order rate constants (K) among different particle sizes was K20nm>K100nm>K10μm>K100μm. Comparing K among four target HOCs, the reduction rates of chlorinated methane (CT, TCM) are higher than chlorinated ethylene (PCE, TCE), and highly chlorinated HOCs (PCE, CT) were degraded more easily than lower one (TCE, TCM). pH of aqueous solution all increased along the chlorinated compounds reduction which was raised by the reaction between ZVI and water. The oxygen in water consumed the ZVI particle either and competed with the surface adsorbed chlorinated compounds. In summary, Zero-Valent-Iron proved to be an efficient technology for typical HOCs removal, which can be considered as a promising process added in the beginning part of drinking water treatment plant.

    Economic and Environmental Analysis of Household Photovoltaic System: Taking 5 kW Photovoltaic System in Jiangxi Province as an Example
    WEN Zekun, QIU Guoyu
    2018, 54(2):  443-450.  DOI: 10.13209/j.0479-8023.2017.076
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    Based on the survey of household photovoltaic demonstration project in Xinyu City of Jiangxi Province, stable investment recovery period and internal rate of return (IRR) are applied as the economic evaluation index, the energy recovery period and annual savings of standard coal as the environmental benefit evaluation index, the generation power, revenue composition and economic benefits under different circumstances, environmental benefits of 5 kW household photovoltaic system were analyzed. The results show that the yearly power generation of 5 kW household photovoltaic system is 4056.7 kWh, only 79% of the theoretical value. The system has a good economic benefit with the subsidies from the state and Jiangxi Province. The stable investment recovery period is less than 8 years, and the internal rate of return is 11.2%. Lack of subsidies from the state or Jiangxi would have a large impact on the economic benefits of investments. The photovoltaic system also has a good environmental benefit, saving 1.46 tons of standard coal each year, and the energy payback period is 5.22 years. The development of household photovoltaic needs support of national policy and appropriate promotion model.

    Impacts of Mega-Events on City Investment and Financing: An Empirical Analysis of Panel Data from Municipal-Level Cities
    KONG Yinghui, HE Canfei, LIN Chusheng
    2018, 54(2):  451-458.  DOI: 10.13209/j.0479-8023.2017.124
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    The authors adopt panel data from municipal-level cities in China to examine the impacts of holding mega-events on city investment, debt financing and land development. The results indicate that the inhibit effects of holding internationally-influential mega-events on city investment is greater than its promote effects because local governments are devoted to improving city environment in order to enhance city image, so that the decrease of investment resulting from their restrictions on polluting enterprises and high-pollution projects is greater than the increase of investment which mega-events attract. In addition, internationally-influential mega-events and nationally-influential mega-events have significantly positive effects on issuing Quasi-municipal Bond and mortgaging land, helping to break the local government fiscal restraint. Regionally-influential mega-events have significantly positive effects on attracting city investment. Local governments may concern more about city investment and economic development than city image.