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Winter wheat (Triticum aestivum L.) monoculture is common in wheat-growing areas of the Loess Plateau of northwest China. This system is characterized by nearly 3-month summer fallow from wheat harvest at the end of June or early July to sowing in late September. It not only lowers the overall precipitation-use efficiency because of the large amount of evaporation from the bare soil surface during the fallow period but also entails high risk of erosion by summer rainstorms. There is a need to develop more effective cropping systems to replace the current production system. Seven alternative rotations, mainly using wheat, rapeseed, corn, potato, pearl millet, linseed, alfalfa and sweetclover, were established and their use of environmental resources, production performance, energy efficiency, soil fertility sustainability, and soil conservation effectiveness were compared with continuous wheat cropping. The rotations had greater potential use of environmental resources. Despite showing no clear advantage in grain yields, all rotations were significantly higher in total above-ground biomass production and more efficient in energy transformation compared with continuous wheat cropping. After a 3-year cycle, the rotations did not adversely affect soil bulk density but some rotations significantly increased soil water-stable aggregates compared with the initial measurement. For the rotations based on the inclusion of legumes, the availability of N was apparently improved but the total P was substantially reduced compared with the initial measurement and continuous wheat cropping. An assessment of soil conservation effectiveness with a weighted soil conservation effectiveness index (WSCEI) indicated that the rotations performed much better than continuous wheat cropping in conserving soil and water resources. This study also strongly recommend that it is feasible to cultivate winter wheat followed by a 3-month legume fallow crop in year 1 and then a summer crop cultivation in the next. This system provides a soil cover during both erosion-prone rainy periods while leaving the soil bare for about 7 months (October–April) every 2 years. Another alternative is to cultivate winter wheat followed by a 15-month legume crop cultivation in years 1 and 2 and then a summer crop in year 3. This system allows the soil to be covered during three rainy periods while leaving the soil bare for about 7 months every 3 years. As most of this 7-month period is winter with low rainfall (snow) and temperatures below 0 °C, not only is soil evaporation very low but the risk of erosion is also low. [Copyright &y& Elsevier]

Outlines the scope of the 1999 International Symposium on Nativizing Anthropology convened for Nationalities in Nanning, Guangxi, China. Chinese effort to help global anthropology overcome ethnocentrism; Use of Western theories and methods to solve Chinese problems; Application of anthropology in the crafting of governmental policies.

Based on data of haze days observed by Puyang Meteorological Station of Henan Province from 1971 to 2012, climatic characteristics, causes and prevention countermeasures of haze in Puyang were discussed. The results showed that annual average haze days in Puyang tended to increase slightly over the past 42 years on the whole, and the increasing trend became obvious since the 1990s. Meanwhile, haze days in Puyang showed an obvious seasonal variation, that is, haze mainly appeared in autumn (from September to November) and winter (from December to next February), and it was the most frequent in winter. Haze formation was closely related to meteorological and environment elements. Increase of calm wind in horizontal direction, inversion layer in vertical direction, and increase of suspended particulate matter could lead to aggregation of air pollutants, so that haze days increased. Some countermeasures against haze pollution, such as controlling pollution sources, limiting discharge of vehicle exhaust and industrial gases, and increasing green area, should be adopted to reduce haze harm to air quality and human health. [ABSTRACT FROM AUTHOR]

The interconnection of multiple regional integrated energy systems (RIES) can effectively enhance the low-carbon and flexible operation capabilities of RIES, but the uncertainty and multi-energy interaction of the system pose challenges to the stable operation of RIES. Therefore, a stochastic hierarchical optimization and revenue allocation approach is proposed to optimize the operational strategy of multi-RIES with multi-operator participation, multi-energy interactions, and multiple uncertainties. Firstly, agent-based modeling, Latin hypercube sampling and simultaneous backward reduction based on the Wasserstein metric are proposed to capture the power-side and load-side uncertainties. Secondly, based on the Nash bargaining game and the alternating direction method of multipliers algorithm, multi-RIES peer-to-peer transactions of electricity, thermal, and natural gas are optimized through energy cooperation and scheduling strategies. Subsequently, a Nash-Harsanyi bargaining game revenue allocation method that considers both fairness and renewable energy accommodation is proposed to ensure the stable operation of the alliance. Finally, simulations are conducted on a multi-RIES in northern China, demonstrating that the proposed model and approach can achieve inter-grid flexible resource complementarity, improve RIES economics, increase local renewable energy accommodation rate, and reduce carbon emissions. • Multi-RIES multi-energy internal scheduling and P2P transaction co-optimization. • Wasserstein metric is introduced into the SBR model to capture stochastic scenarios. • A multi-RIES stochastic hierarchical optimization model based on cooperative games. • ADMM is used to solve distributed stochastic hierarchical optimization model. • A revenue allocation method considering equity & renewable energy development is proposed. [ABSTRACT FROM AUTHOR]

Energy consumption issues are important factors concerning the achievement of sustainable social development and also have a significant impact on energy security, particularly for China whose energy structure is experiencing a transformation. Construction of an accurate and reliable prediction model for the volatility changes in energy consumption can provide valuable reference information for policy makers of the government and for the energy industry. In view of this, a novel improved model is developed in this article by integrating the modified state transition algorithm (MSTA) with the Gaussian processes regression (GPR) approach for non-fossil energy consumption predictions for China at the end of the 13th Five-Year Project, in which the MSTA is utilized for effective optimization of hyper-parameters in GPR. Aiming for validating the superiority of MSTA, several comparisons are conducted on two well-known functions and the optimization results show the effectiveness of modification in the state transition algorithm (STA). Then, based on the latest statistical renewable energy consumption data, the MSTA-GPR model is utilized to generate consumption predictions for overall renewable energy and each single renewable energy source, including hydropower, wind, solar, geothermal, biomass and other energies, respectively. The forecasting results reveal that the proposed improved GPR can promote the forecasting ability of basic GPR and obtain the best prediction effect among all the other comparison models. Finally, combined with the forecasting results, the trend of each renewable energy source is analyzed. [ABSTRACT FROM AUTHOR]