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Preparation of porous regenerated lignocellulose-beads from wheat straw:influence of the concentration of raw materials on the performance of beads
- ZHANG Huazhen, ZHANG Zhiguo, GUO Cunyue
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2017, 34 (6):
667-674.
DOI: 10.7523/j.issn.2095-6134.2017.06.003
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Abstract (
202 )
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The utilization of lignocellulose such as straw has spurred wide interests. In this study, wheat straw was employed to prepare porous regenerated lignocellulose-beads (LBs) by an emulsification-solidification-freeze drying process using[Bmim]Cl as a solvent. The lignocellulose-beads fabricated at four different concentrations of wheat straw-solution were compared. The beads derived from 5% wheat straw-solution was found to have regular morphology, uniform micro-structure, the biggest specific surface area, and the maximum ability of nitrogen adsorption rate. The thinner the wheat straw-solution was, the narrower the particle size distribution was. There existed a positive correlation between the degree of crystallinity of cellulose in LBs and the concentration of wheat straw-solution. These results suggest that the concentration of wheat straw-solution was the predominant factor for the preparation of porous regenerated lignocellulose-beads. This work contributes significantly to the understanding of physical and chemical properties of LBs and to the optimization of process parameters.
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Study on the zinc tolerance and translocation mechanisms of “Zhongyou”, a zinc-rich wheat variety
- ZHAO Huijun, XU Shuya, ZHANG Xiu
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2017, 34 (6):
675-683.
DOI: 10.7523/j.issn.2095-6134.2017.06.004
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Abstract (
286 )
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The zinc-rich wheat variety "Zhongyou" was used as research material to study responses of physiological and biochemical changes at the seedling stage under Zn stress by using hydroponic cultivation. The effects of different concentrations of Zn treatments on the cell death phenomenon were observed, and the above ground tissue Zn accumulation and its effect on antioxidant system (SOD, POD, and APX) were studied. TaHMA1(Heavy metal ATPase) was obtained by using 5' and 3'race technologies, and the expression patterns of HMA1, HMA2, PCs, and MT under Zn treatment were studied by using quantitative real-time PCR. Our results are given as follows.This variety has the ability to accumulate high-concentration Zn in above ground tissue. Zn leads to the cell death in root tissue and the inhibition of the SOD activities in leaf tissue, but improves the POD and APX activities. TaHMA1, TaHMA2, and PCs are induced by Zn, and they may play important roles in absorbing and accumulation of Zn in above ground tissue.
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Coupling coordination degree of socio-economic development with resource and environment in Zhaotong City of Yunan Province as a fragile region
- WANG Min, ZHANG Xiaoping
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2017, 34 (6):
684-691.
DOI: 10.7523/j.issn.2095-6134.2017.06.005
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Abstract (
303 )
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Exploring a coordinated development pattern between soico-economic development and natural environment has important significance for realizing the regional sustainable development, especially in ecologically fragile regions. In this work, the relative resource carrying capacity model and the coordinated development model were used to analyze the coordinated development level in Zhaotong City of Yunnan Province. The results indicated that economic-resource & environmental-social system (E-RE-S) in Zhaotong City was not harmonious. The contradiction resulted mainly from the relatively low carrying capacity in social resources. The economic value of resources has not been fully developed yet. The reason of E-RE-S disorder was the unreasonable structure, especially the low development level of secondary industry.
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Survey, evaluation, and visualization system of tourism resources based on LBS and GIS
- LI Peng, WANG Yingjie, YU Hu, MA Nan
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2017, 34 (6):
692-700.
DOI: 10.7523/j.issn.2095-6134.2017.06.006
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Abstract (
324 )
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With the trend of rise and rapid development of LBS, the information means for tourism census is unceasingly highlighted. Taking Penglai of Shandong Province as an example, we design and verify the location application of Internet-based service platform of GIS system. This system, with ArcGIS API for JavaScript technology being the core, is completed by multilayer system structure of thinclient. Then we successfully transfer the subsystem of GIS to the platform of LBS by component package. We expound the platform of this technology, analyze the modern mainstream WebGIS development tools, and select a proper solution after comparison. The system is divided into four subsystems:tourism resources collection and reporting subsystem, automatic database construction subsystem, analysis and evaluation subsystem, and web publishing and visualization subsystem. The services of automatic database construction, tourism resource statistics and analysis, and visualization are realized by using code and classification based on Chinese standard and by combining with web map, high-resolution remote sensing image, and GPS technology. This work will play a strong supporting role for the tourism resource development and product construction in the future.
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Evaluation and strategy for urban tourism competitiveness of Guangdong Province
- CHEN Peiran, ZHANG Luocheng
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2017, 34 (6):
701-711.
DOI: 10.7523/j.issn.2095-6134.2017.06.007
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Abstract (
275 )
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In this work, 19 indicators selected in three aspects, including economic competitive advantage, competitive potential, and basic support, were used to evaluate the tourism competitiveness of cities in Guangdong Province. By using the method of grey relational analysis based on entropy weight, the tourism competitiveness of every city in Guangdong was evaluated, and the results show that the comprehensive evaluation indexes of tourism competitiveness in Guangzhou and Shenzhen are much higher than in the other cities. In the comprehensive ranking, the first part includes Dongguan, Foshan, Zhuhai, Huizhou, and so on, and the last part includes Jieyang, Chaozhou, Shanwei, Yangjiang, and so on. Furthermore a preliminary study on the relationship between urban size and urban tourism competitiveness was made. The regional pattern of tourism in Guangdong shows a core-edge structure surrounding the Pearl River Delta region. Our method was compared with TOPSIS method, and we analyzed the reliability of distinguishing coefficients and the origin of data volatility. In this work the advice and strategy were proposed for improving tourism competitiveness of Guangdong Province at urban scale and regional scale.
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Evaluation and analysis of highway transportation efficiency in the Yangtze River Delta based on DEA-Malmquist
- ZHANG Lulu, WU Wei, LIU Binquan
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2017, 34 (6):
712-718.
DOI: 10.7523/j.issn.2095-6134.2017.06.008
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Abstract (
256 )
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Transportation efficiency is an important index for highway transportation service evaluation. This research evaluated the highway transportation efficiency for the 16 cities of the Yangtze River Delta in 2014 using the BCC model combined with the super-efficiency model in data envelopment analysis (DEA) method. With the DEA-Malmquist method, spatial and temporal development characteristics of highway transportation total factor productivity (TFP) were analyzed. Some conclusions were drawn as follows. 1) The overall efficiency of the highway transportation in the Yangtze River Delta was high in 2014, but there were some regional differences and the integrated transportation efficiency of the southern part was significantly higher than that of the northern part, which was decided by scale efficiency. 2) Malmquist index of highway transportation from 2007 to 2014 showed a certain fluctuation but was relatively stable in overall. The fluctuation in technical progress of the highway transportation was the main factor in the change in TFP. From the point of view of the space-time evolution from 2007 to 2014, the Malmquist index increased first and then decreased, while the regional difference decreased first and then increased. The regional difference in the northern part was larger than that in the southern part.
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Modern pollen-vegetation relationships and two new pollen-climate indices in the Yarlung Zangbo River basin in southern Tibetan Plateau
- SUN Aizhi, ZHANG Dehuai, DAI Ranran
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2017, 34 (6):
719-733.
DOI: 10.7523/j.issn.2095-6134.2017.06.009
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Abstract (
322 )
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This study collected 70 pollen surface samples along an east-west transection in the Yarlung Zangbo River (YLZR) basin in the southern Tibetan Plateau. Pollen assemblage and principle components analysis results show that each vegetation zone along the transection is characterized by distinctive modern pollen assemblages as follows:1) pine forest zone:Pinus pollen assemblage; 2) fir and spruce forest zone:Abies-Pinus-Picea pollen assemblage; 3) broadleaved forest/shrubland zone:Quercus-Betula-Pinus pollen assemblage; 4) alpine meadow zone:Cyperaceae-Artemisia-Compositae pollen assemblage; and 5) alpine steppe zone:Artemisia-Cyperaceae-Poaceae pollen assemblage. We use the data to define two new pollen-climate indices, (Pi, Ti), based on the ratio between major pollen taxon groups and subgroups. The indices represent the mean annual precipitation (MAP) and mean annual temperature (MAT) of the study area, and they closely track the regional west-east gradients in precipitation and temperature across the YLZR basin. We suggest that the pollen-vegetation-climate indices may be useful for future palaeoclimatic reconstructions using fossil pollen data.
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Ship wake detection in SAR images with complex backgrounds based on relative total variation
- YANG Guozheng, YU Jing, SUN Weidong
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2017, 34 (6):
734-742.
DOI: 10.7523/j.issn.2095-6134.2017.06.010
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Abstract (
383 )
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The ship wake detection in SAR images is not only helpful in estimating the speeds and the directions of moving ships, but also in finding small ship objects. The existing ship wake detection methods achieve satisfactory results only for SAR images with simple backgrounds, but hardly work for SAR images with complex backgrounds. This work proposes a ship wake detection method for SAR images with complex backgrounds based on the relative total variation (RTV). The proposed method decomposes an SAR image into a cartoon component which contains ship wakes and an oscillating component which includes sea surface textures. Then the shearlet transform is used to process the cartoon component and some high-frequency coefficients are reconstructed to enhance the cartoon component. Finally the Radon transform is used for the enhanced cartoon component to detect ship wake lines. The comparison with the experimental results shows that the proposed method for the ship wake detection in SAR images with complex backgrounds obviously outperforms the existing methods.
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PS-InSAR surface deformation prediction method based on Kalman filter
- LIU Xing, LÜ Xiaolei
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2017, 34 (6):
743-750.
DOI: 10.7523/j.issn.2095-6134.2017.06.011
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Abstract (
425 )
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PS-InSAR is a microwave remote sensing technique which provides high-resolution maps of large-scale ground displacement. However, it is incapable of deformation prediction. The existing deformation prediction approaches can be only applied to a few point targets, but are limited in monitoring relatively large areas. In this work, a surface deformation prediction method of PS-InSAR is proposed based on Kalman filter. First, the process of PS-InSAR is outlined. Then a Kalman filter is designed theoretically. Finally, the experiments performed on the real multi-temporal SAR data confirm the validity of the proposed method. The experimental results show that the proposed approach makes full use of the displacement information acquired from PS-InSAR and effectively predicts the trend of ground deformation over wide areas.
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Spaceborne bistatic SAR imaging method based on Bakhshali approximation
- YUAN Jili, LÜ Xiaolei, LIN Jianhe
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2017, 34 (6):
751-758.
DOI: 10.7523/j.issn.2095-6134.2017.06.012
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Abstract (
272 )
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Distributed spaceborne SAR and medium-or high-orbit SAR are receiving increasing focus with the development of satellite technology, while the extended synthetic aperture length and long baseline pose new challenges to the bistatic SAR imaging. In this work we propose a new hyperbolic equivalence method based on Bakhshali approximation. Besides, an appropriate CS imaging procedure is designed. Compared to the original method, the proposed method meets the requirements. Finally, the simulation results verify the validity of the proposed method.
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A wireless router-based lightweight defense framework for IoT devices
- YAN Zhitao, FANG Binxing, LIU Qixu, CUI Xiang
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2017, 34 (6):
759-770.
DOI: 10.7523/j.issn.2095-6134.2017.06.013
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Abstract (
439 )
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It is well known that IoT (Internet of things) devices are vulnerable and can be easily intruded by attackers. However, traditional protection methods for PCs are no longer suitable for IoT devices. In this work, we design a router-based lightweight defense framework WRGuardian (wireless router guardian) which uses the router's network traffic controllability and computing capacity to protect IoT devices. It will monitor and block the attack behaviors to IoT devices, and it will detect and fix the security issues by simulating attacks. Because there is no requirement of additional security hardware for the IoT devices, this protection framework has a low cost, and it is convenient to deploy and beneficial for promotion. Our experimental results show that WRGuardian is feasible and protects IoT devices from main attacks. It is an effective lightweight solution.
