• Energy Research
• 12. Responsible consumption close
• 2. Zero hunger close
• Chinese Academy of Sciences close

The Upper Yangtze River Basin comprises a densely-populated agricultural region with mountainous and hilly landforms. Intensive cultivation has been extended onto steep hillslopes, which constitute the principal source area for sediment production. Soil conservation on sloping arable lands is thus of utmost priority for persisting sustainable agricultural production and maintaining sound ecosystem services. Although there have been many soil conservation techniques, either promoted by the government or adopted by local farmers, the practiced area was very limited relative to the total area affected by soil erosion. This paper attempts to introduce four popular soil conservation measures on sloping arable lands in this region to enhance a broader scale of implementation, including hedgerow buffers, level trenches, sloping terraces and limited downslope tillage. These practices, although developed from local farmers’ indigenous knowledge for productive purposes, have well conformed to our contemporary understanding of soil erosion processes on sloping landscape affected by human disturbances, were of sound suitability to regional manual tillage agriculture and more trade-off-efficient on rill prevention, runoff harvest and nutrient management.

Abstract The coal gasification process is one of the main exergy destruction contributors in polygeneration systems and has considerable energy saving potential. In the present study, for improving the performance of the polygeneration system, the coal-steam gasification method was employed to integrate a novel methanol-electricity polygeneration system. The results indicated that the energy efficiency of the novel system was 63.3% with a chemical-to-power output ratio of 8.4, while the energy efficiency of the traditional system is 51.3% at the optimal unreacted syngas recycling ratio. Exergy analysis results revealed that the system exergy destruction in the coal–steam gasification process is 7.5% smaller than that in the GE gasification process, and eliminating the air separation unit can reduce the exergy destruction of the system by 4.3%. Additionally, the energy saving contributions of gasification process improvement and system integration were quantitatively evaluated. When the chemical-to-power output ratio increased from 1.9 to 11.9, the energy saving contributions of the system integration and gasification process improvement ranged from 9.8% to 15.1% and 11.9% to 12.9%, respectively.

Citrus wastes disposal is a problem faced by many juice plants due to high disposal costs. However, the citrus peel wastes (CPW) biomass, as bulk bioresources from the agro-industrial waste, is a good source of pectin. Present study aimed to utilize these CPW biomass by engineered yeast strain fermentation with an inexpensive method to produce oligogalacturonides (OGs). The results showed that the engineered yeast strain fermentation can produce significant amounts of OGs with the degree of polymerization ranged from 2 to 7 from the CPW bioresources. Under the optimized conditions using the response surface methodology, the best OGs yield were 26.1%. The present work is the first to use the engineered yeast strain for direct CPW biomass fermentation produced the OGs. We thereby paved a new way to utilize the pectin-rich bioresources.

Abstract Background Mulberry leaf as a traditional Chinese medicine is able to treat obesity, diabetes, and dyslipidemia. It is well known that diabetes leads to intestinal microbiota dysbiosis. It is also recently discovered that liver glycogen structure is impaired in diabetic animals. Since mulberry leaves are able to improve the diabetic conditions through reducing blood glucose level, it would be interesting to investigate whether they have any positive effects on intestinal microbiota and liver glycogen structure. Methods In this study, we first determined the bioactive components of ethanol extract of mulberry leaves via high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Murine animal models were divided into three groups, normal Sprague-Dawley (SD) rats, high-fat diet (HFD) and streptozotocin (STZ) induced type 2 diabetic rats, and HFD/STZ-induced rats administered with ethanol extract of mulberry leaves (200 mg/kg/day). Composition of intestinal microbiota was analyzed via metagenomics by sequencing the V3-V4 region of 16S rDNAs. Liver glycogen structure was characterized through size exclusion chromatography (SEC). Both Student’s t-test and Tukey’s test were used for statistical analysis. Results A group of type 2 diabetic rat models were successfully established. Intestinal microbiota analysis showed that ethanol extract of mulberry leaves could partially change intestinal microbiota back to normal conditions. In addition, liver glycogen was restored from fragile state to stable state through administration of ethanol extract of mulberry leaves. Conclusions This study confirms that the ethanol extract of mulberry leaves (MLE) ameliorates intestinal microbiota dysbiosis and strengthens liver glycogen fragility in diabetic rats. These finding can be helpful in discovering the novel therapeutic targets with the help of further investigations.

Abstract The development of the regional economy in China is unbalanced. Interregional "carbon leakage" and "carbon transfer" have a significant impact on the realization of carbon emission mitigation targets and the allocation of responsibility. Using China's interregional input-output tables and the corresponding carbon emission data for 2007 and 2010, this paper proposes an interregional Ghosh input-output model and estimates the amount of interprovincial carbon emission transfer from the supply-side perspective. We find that the main direction of supply-side carbon emission transfer is from resource-intensive provinces in the central and western regions to developed provinces in the eastern coastal regions. Further analysis shows that the transfer is mainly concentrated in the production and distribution of electricity and heat, nonmetallic mineral products, and basic metals, whose carbon emissions account for approximately 70% of all sectors’ carbon emissions. The differences between the supply side and the demand side of China's provinces are mainly reflected in the transfer out of carbon emissions.

Batch tests were conducted to enhancing simultaneous electricity production and reduction of sewage sludge in two-chamber MFC by aerobic sludge digestion in cathode chamber and sludge pretreatments (sterilization and base pretreatment) prior to sludge addition to anode chamber, respectively. During the stable stage, The voltage outputs and power densities of MFC increased from 0.28-0.31 V to 17.3-21.2 mW/m(2) to 0.41-0.43 V and 36.8-40.1 mW/m(2), respectively, when aerobic sludge digestion occurred in the cathode chamber. When the sludge added to the anode chamber was sterilized or base pretreated, the voltage outputs and power densities of MFC increased from 0.30-0.32 V and 19.9-22.6 mW/m(2) (raw sludge) to 0.34-0.36 V and 25.5-28.6 mW/m(2) (sterilized sludge), 0.41-0.43 V and 37.1-40.8 mW/m(2) (base pretreated sludge), respectively. At the end of the test, the total suspended solids (TSS) and volatile suspended solids (VSS) reduction of sludge in the anode chambers increased from 33.9% and 36.8% to 34.5% and 38.7% with aerobic sludge digestion in the cathode chamber, respectively; while, those (TSS and VSS reduction) with sludge pretreatments prior to the sludge addition to the anode chambers increased from 25.1% and 22.8% (raw sludge) to 32.8% and 34.6% (sterilized sludge), and 25.5% and 26.7% (base pretreated sludge), respectively. The experimental results illuminated both aerobic sludge digestion in the cathode chamber and sludge pretreatments (sterilization and base pretreatment) prior to sludge addition to the anode chamber could enhance simultaneous electricity production from sludge and sludge reduction.

SignificanceEstimates of nutrient allocation in different plant tissues and the relationships between the nutrient contents and photosynthetic capacity are critical to predicting ecosystem carbon sequestration under global change. Here, we provide an assessment of large-scale patterns of community-level nitrogen and phosphorus concentrations in different plant tissues and then examine how nutrient allocations are coupled with plant productivity. The results show that nutrient concentrations in leaves are less responsive to abiotic environments than those in woody stems and roots (stable leaf nutrient concentration hypothesis); the relationships between vegetation primary productivity and leaf nutrient contents are stronger when less nutrients are allocated to the woody tissues (productivity–nutrient allocation hypothesis) and are stronger in deciduous than in evergreen vegetation (productivity–leaf lifespan hypothesis).

Urban and rural dual structure in Western China is obvious. The economic development of the central cities is relatively quick while that of the rural areas is lagging behind. The speeding up of urbanization contributes to the intensively uncoordinated development of urban and rural areas. Besides, the eco-fragile environment, shortage of available water resources, adverse geographic location, and relatively backward social economy restrict the development of urbanization in Western China. However, Western China also has the advantages of backwardness. This paper analyzes the present situation and development trend of urbanization in Western China. The results show that Western China has basically formed a development pattern with “industry promotes agriculture and urban leads to village”. Therefore, combined with the present situation of Western China, this paper describes and analyzes the opportunities and challenges that may appear in the process of urbanization in Western China, puts forward the devel...