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Wei J.,Beijing Forestry University | Huang K.,Beijing Forestry University | Yang S.,Hunan Academy of Social Science | Li Y.,Hubei Water Resources Research Institute | And 2 more authors.
Journal of Cleaner Production | Year: 2016

Low carbon dioxide (CO2) emissions are the foundation on which to realize the sustainable development of a green China. Recently in Beijing, the capital of China, serious environmental pollution-climate anomaly, severe haze and human sub-health have been accorded more importance. This study examines the energy-related CO2 emissions generated by Beijing industries from 2000 to 2010 by using an input-output analysis method. The direct, indirect and total CO2 emissions of sectors in Beijing were calculated. In addition, structural decomposition analysis (SDA) was conducted to evaluate the driving factors from the perspective of technology, sectoral connection, economic structure and economic scale. The results show that the growth rate of sectoral CO2 emissions in Beijing has drastically increased during this time with a moderate decline during 2007-2010. The metal and non-metal mining industries, the electric power, gas and water supply sector and the construction industry caused the most CO2 emissions. The economic structure change and the rapid economic growth led to the significant increase in CO2 emissions growth in Beijing. Thus, optimizing the economic structure and improving the technology are important to alleviate CO2 emissions. Although we can currently appropriately utilize fossil fuels, further research on new energy and clean development, as well as enhanced government management strength is required to reduce CO2 emissions. © 2016 Elsevier Ltd.

Fang N.-F.,Northwest University, China | Fang N.-F.,CAS Institute of Soil and Water Conservation | Shi Z.-H.,Northwest University, China | Shi Z.-H.,CAS Institute of Soil and Water Conservation | And 5 more authors.
Catena | Year: 2012

This paper analyzes runoff and soil loss in relation to the rainfall regimes and land use changes in a small mountainous watershed in the Three Gorges Area (TGA) of China. Based on 10. years of rainfall measurements and K-means clustering, 152 rainfall events were classified into three rainfall regimes. The mean statistical features of different rainfall regimes display a marked difference. Rainfall Regime I is events of medium amounts (31.8. mm) and medium duration (1371. min). Rainfall Regime II is events with high amounts (54.0. mm), long duration (2548. min), and an infrequent occurrence. Rainfall Regime III is events of low amount (22.2. mm), short duration (494. min) and high frequency. Each rainfall regime results in differing levels of runoff and erosion and Rainfall Regime I causes the greatest proportion of accumulated discharge (368.7. mm) and soil loss (4283. t). In the different rainfall regimes, the values of the mean runoff coefficient and the mean sediment load were ordered as follows: Rainfall Regime II > Rainfall Regime I > Rainfall Regime III. These results suggest that greater attention should be paid to Rainfall Regimes I and II because they had the most erosive effect. In the Wangjiaqiao watershed, the changes in land use primarily affected the paddy fields, where the cropland decreased significantly and the forest and orchards increased by 9.9% and 7.7%, respectively, during 1995-2004. The ANOVA shows land use changes caused significant decreasing trends in the runoff coefficients (P < 0.01) and sediment loads (P < 0.01). In order, the most sensitive response of runoff and erosion to land use was Rainfall Regime II > Rainfall Regime > Rainfall Regime III. Rainfall characteristics are decisive for the relative importance of different storm runoff generation mechanisms. The land use changes in the study watershed have considerably decreased runoff and soil loss. © 2012 Elsevier B.V.

Hu L.,Harbin Engineering University | Jiang S.,Harbin Engineering University | Zhang Y.,Harbin Engineering University | Zhao Y.,Harbin Engineering University | And 2 more authors.
Intermetallics | Year: 2016

A Ni-rich NiTi shape memory alloy (SMA), which was in its austenitic state at ambient temperature, was subjected to plastic deformation by means of local canning compression at various temperatures ranging from room temperature to 800 °C. Depending on temperatures, NiTi SMA exhibited multiple plastic deformation mechanisms, such as dislocation slip, deformation twinning, grain boundary slide, grain rotation, dislocation climb and grain boundary migration. Amorphization, dynamic recovery and dynamic recrystallization of NiTi SMA were also observed at various temperatures. Mechanism of localized amorphization, in particular, was investigated based on dislocation slip and deformation twinning. Statistically stored dislocation (SSD) and geometrically necessary dislocation (GND) were found to play an important role in the amorphization of the current NiTi SMA. There appeared a critical dislocation density below which NiTi SMA was unable to amorphize. Accordingly, at a fixed deformation strain, there should be a critical temperature above which amorphous phase would not occur in the NiTi SMA matrix. Furthermore, when NiTi SMA experienced plastic deformation at the critical temperature, amorphization and crystallization would occur simultaneously and compete with each other. © 2015 Elsevier Ltd. All rights reserved.

Wang J.-G.,Huazhong Agricultural University | Yang W.,Hubei Water Resources Research Institute | Yu B.,Huazhong Agricultural University | Li Z.-X.,Huazhong Agricultural University | And 2 more authors.
Catena | Year: 2016

Background: Stable macro- or micro-aggregates are important for preventing soil degradation. The interactions among soil aggregates and stabilizing agents-like clay, soil organic matter (SOM), Fe, and Al oxides-are complex and have not been fully understood. Methods: Eight ultisol samples were collected from the surface (0-10 cm) and subsurface layers (10-20 cm). The macro-aggregate stability was determined by wet sieving, and the micro-aggregate distribution was determined via particle size distribution analysis; however, no chemical dispersant (sodium hydroxide) was applied. Using the PLSR models, the main soil properties that affect macro-aggregate and micro-aggregate stability were estimated. Results: All soils were strongly acidic (pH4 28-5.56) with low SOM content (<20 g kg-1). The dithionite-citrate-bicarbonate extractable Fed and Ald were the dominant forms in Fe and Al oxides, much greater than acid ammonium oxalate extractable Feo and Alo. For most soils, the percentage of >5mm aggregates was the highest, and the percentage of 2-1mm aggregates was the lowest after wet sieving. Soil parent materials had a significant effect on the particle size distribution of the micro-aggregates. The stability of macro-aggregates and micro-aggregates from Quaternary red clay was stronger than that from Shale (p<0.05). Regardless of the soil parent materials, the water stability of surface cropland soil macro-aggregates was significantly lower than that of the other land-use types, but the micro-aggregate stability exhibited no trend across different land use types. Conclusion: Ald was the most important binding agent of the macro-aggregates, and clay was the main binding agent of the micro-aggregates, followed by the Fed, Alo, CEC and SOM, while Feo was the weakest agent. © 2015 Elsevier B.V.

Liu L.,Wuhan University | Liu L.,Hubei Water Resources Research Institute | Cui Y.,Wuhan University | Luo Y.,Hohai University
Journal of Irrigation and Drainage Engineering | Year: 2013

The Yellow River Basin is a closed basin under serious stress with dense population, intensive agriculture, and excess water withdrawals. Low water use efficiency and groundwater overexploitation are threatening the sustainable development of the basin. This paper describes a coupled modeling approach to analyze sustainable management strategies in surface-groundwater conjunctive use irrigation districts in the lower Yellow River Basin. An appropriate irrigation schedule and an optimal range of groundwater levels are first established using the soil water atmosphere plant (SWAP) model with data from an irrigation experiment station. The integrated surface water and groundwater model was then set up using modified soil and water assessment tool (SWAT2000) and modular three-dimensional groundwater flow model (MODFLOW) models. The two models were connected through standardized simulation grids and calibrated using field measurements. Five scenarios that were designed according to different well-canal irrigation supply ratios and the irrigation schedule determined by SWAP were tested using the integrated modeling approach. It is proved that conjunctive management strategies of canal diversions and tube-well pumps can effectively reduce phreatic evaporation losses, increase water use efficiency, and sustain groundwater levels while maintaining crop yields at current levels. © 2013 American Society of Civil Engineers.

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