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Abstract The renewable energy targets put forward by the Chinese government need comprehensive incentive schemes. This paper uses a multi-regional CGE model to evaluate two types of renewable support schemes; a subsidy scheme like a feed-in tariff (FIT) with a direct price impact for final consumers and a subsidy scheme without any price impact. We assess the CO 2 consequences of both approaches, as well as their impact on economic activity in terms of GDP, industrial structure, electricity generation structure, and regional final demand elasticities of electricity. We find that a support scheme with price impact is much more effective in reducing CO 2 emissions while the difference in GDP between the two policies is small. We estimate that the price implications of the support scheme allow for an additional emissions reduction of 113 Mt CO 2 —or 0.07% of total emissions—in China during 2020–2035. The support scheme with a price impact does not lead to a negative impact on the Chinese economy although there are significant differences among regions. In addition, while the whole country faces an approximately unitary electricity elasticity demand, we find significant differences in electricity demand elasticities among Chinese regions.

Soil microbial biomass is key to improving the prediction of soil organic carbon (SOC) dynamics by modeling. However, the driving mechanism of microbial biomass of different groups with soil depth is poorly understood across sites. Here, we compiled the biomass of different microbial groups (i.e., fungi, bacteria, gram-positive bacteria G+, and gram-negative bacteria G-) from the surface to a soil depth of 1 m from 71 soil profiles across three continents. We found that the biomass of microbial groups all decreased with soil depth but at different magnitudes, while the relative abundance of microbial groups, except G-, was relatively stable along soil profiles. Soil fungal biomass had a shallower vertical distribution than bacteria, especially G+, with 89% fungi and 76% G+ in the top 10 cm soils. In addition, a greater proportion of microbial biomass (71-89%) compared to SOC (64%) was in the top 10 cm soils, suggesting that microbes and SOC exhibited different vertical distributions. The vertical distributions of microbial biomass of different groups were significantly correlated with SOC and clay content but not with climate, and these distributions were different among land uses, highlighting the great influences of edaphic factors on vertical distributions of microbial biomass. The relationship between microbial biomass and soil depth provides a feasible way to estimate microbial biomass at different soil depths, which can serve as a benchmark to improve the prediction of SOC dynamics of entire soil profile at large scales.

Abstract We have studied the effect of different cleanings at device level for nPERT (passivated Emitter, Rear Totally diffused) cells with a rear epitaxial emitter. Cleanings based on sulfuric acid and peroxide mixtures (SPM), which are effective but also expensive, were used as reference. We found that simplified cleanings such as those based on sulfuric acid and ozone mixtures (SOM), and those based on water and ozone (IPV), are giving similar results at device level as the expensive SPM cleaning, leading to similar J0e, J0, FSF, and lifetime values. The implied VOC values of corresponding test devices fabricated using the simplified cleanings are at the same high level as the test devices using more expensive SPM cleanings. Actual nPERT devices with moderately doped epitaxially-grown emitters with a constant doping profile (box profile) showed average efficiencies above 22.0% for both SOM and IPV cleanings. Very high VOC values of up to 695 mV and implied VOC values of up to 730 mV were shown for cells with a flat rear surface. Finally, the best nPERT cells with rear epitaxial emitter and SOM cleaning showed efficiencies up to 22.5%, as externally confirmed by ISE CalLab.

This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol.

The highly thermally conductive graphene-based electrodes for supercapacitors exhibit great heat dissipation ability as well as excellent cycling performance and rate capacity.

The increasing frequency and intensity of droughts in a warming climate are likely to exacerbate adverse impacts on ecosystems, especially for water-limited regions such as Central Asia. A quantitative understanding of the impacts of drought on vegetation is required for drought preparedness and mitigation. Using the Global Inventory Modeling and Mapping Studies NDVI3g data and Standardized Precipitation Evapotranspiration Index (SPEI) from 1982 to 2015, we evaluate the vegetation vulnerability to drought in Central Asia based on a copula-based probabilistic framework and identify the critical regions and periods. Furthermore, a boosted regression trees (BRT) model was also used to explore the relative importance of environmental factors and plant traits on vegetation response to drought. Additionally, we also investigated to what extent irrigation could alleviate the impacts of drought. Results revealed that months from June to September was the critical period when vegetated areas were most vulnerable to drought stress. The probabilities of vegetation loss below 20th quantile under extremely dry in these months were 68.7%, 69.4%, 71.0%, and 67.0%, respectively. Regarding vegetation-vulnerable regions, they shifted with different growth stages. During the middle of the growing season, semi-arid areas were the most vulnerable regions, whereas the highest drought-vulnerable regions were observed in arid areas during other periods. The BRT results showed that plant traits accounted for a large fraction (58.9%) of vegetation response to drought, which was more important than ambient soil environment (20.8%). The analysis also showed that mitigations from irrigation during July to September were smaller than in other months. The results of this paper provide insight into the influences of drought on vegetation and may contribute to drought mitigation and land degradation measures in Central Asia under accelerating global warming.

The massive desiccation of the Aral Sea, the fourth largest lake in the world, has led to severe ecological problems, expansion of cropland was thought to be the main factor driving that shrinkage. But this study performed a long-term land cover and use change assessment for Aral Sea Basin (ASB) to show that the cropland has stopped expanding in 2000, of which the cropland in the ASB plain area has decreased significantly (-140 km2/year) from 2001 to 2019. By contrast, this study finds the hydrological cycle in the ASB has intensified through a spatial and temporal scale approach based on Earth observation. Specifically, there is a 7.21 % (+304.56 × 108 m3) increase in annual total precipitation and a 10.13 % (+376.21 × 108 m3) increase in annual total actual evapotranspiration (AET) for the whole ASB during 1980-2019. In particular, the total annual AET in the ASB plain area has increased by 37.81 % (+718.92 × 108 m3), which almost depletes the water that should have flowed into the Aral Sea. Therefore, the Aral Sea shrank by 5625 × 108 m3 (or 42,944.32km2) from 1980 to 2019. Changing climate and increasing AET have accelerated the desiccation of the Aral Sea, and the expansion of cropland is no longer the main factor of that shrinkage. After more water was conserved in the ASB plain area, evapotranspiration plays a more vital role in the Aral Sea shrinkage. Reducing AET and unproductive water losses are key initiatives in future projects to save the Aral Sea. This study explores the causes of Aral Sea shrinkage from an integrated perspective of climate-land-water-ecological change across the ASB, bridging the limitations of previous studies that have focused on Aral Sea waters and subbasins.