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China is the largest fruit producer and consumer market in the world. Understanding the growing conditions responses to climate change is the key to predict future site suitability of main cultivation areas for certain deciduous fruit trees. In this study, we used dynamic and growing degree day models driven by downscaled daily temperatures from 22 global climate models to project the effects of climate change on growing conditions for deciduous fruit trees under two representative concentration pathway (RCP) 4.5 and RCP8.5 scenarios over 2 future time periods (represented by central years 2050s and 2085s) in northern China. The results showed a general increase of available winter chill for all sites under RCP4.5 scenario, and the most dramatic increase in chill accumulation could reach up to 36.8% in northeast regions for RCP8.5. However, the forecasted chill will decrease by 6.4% in southeast stations under RCP8.5 by 2085s. Additionally, the increase rate of growing season heat showed spatially consistency, and the most pronounced increase was found in the RCP8.5 by 2085s. For the southwest station, median heat accumulation increased by 20.8% in the 2050s and 37.1% in the 2085s under RCP8.5. Similar increasing range could be found in the northeast station; the median growing season heat increased by 19.8% and 38.8% in the 2050s and 2085s under RCP8.5, respectively. Moreover, the date of last spring frost was expected to advance and the frequency of frost occurrences was projected to decline in the study area compared to the past. Overall, the present study improves understanding regarding site-specific characteristics of climatic suitability for deciduous fruit tree cultivation in main producing regions of northern China. The results could provide growers and decision-makers with theoretical evidence to take adaptive measure to ensure fruit production in future.

Abstract In this paper, coupled governing equations were proposed to simulate three-dimensional heat conduction and moisture transport in the nuclear waste repository. Because there will be a large temperature gradient near inner and outer boundaries of the bentonite buffer layer, and the heat driven moisture transport is introduced in the governing equation of moisture transport. By applying the Fourier and Laplace transforms, the governing equations were converted to the Bessel equations, and the Laplace-domain solutions to temperature and moisture distributions were derived through the inverse Fourier transform. The reliability of the proposed solutions was verified through comparative analysis with the line heat source model. These analytical solutions were applied to obtain the evolutions of temperature field and moisture distribution near the waste canister. Finally, a sensitivity study was performed to analyze the effects of relevant parameters on the heat driven moisture transport.

In developing an algal treatment system, selenium (Se) removal efficiency by Chlorella vulgaris was evaluated under various conditions such as Se concentration, algal density, temperature and pH. A maximum removal efficiency plateau of ∼90% was observed between 1000-3000 μg Se/L while the tolerance of Se toxicity was found at 6000 μg Se/L. C. vulgaris of 0.75 g DW/L showed the highest removal efficiency (84%), and volatilization was dominant below 1.37 g DW/L. Se volatilization was two times higher at 25 °C than at 20 °C in the first 24 h. Moreover, the highest removal efficiency (77%) was obtained at pH 8.0, compared to 66.5% at pH 6.5 and 40% at pH 10.0. To prevent ecotoxicity, Se laden algae were further burned to ashes or filtered out by Anodonta woodiana. After burning, biomass Se was reduced by 99%, with organo-Se entirely converted into inorganic Se, lowering Se bioavailability. A. woodiana removed 54% of Se in 24 h, leading to Se bioaccumulation in soft tissues, which may serve as dietary Se supplements for human health. Our results suggest the cleanup of Se-contaminated water from either agricultural runoff or industrial discharge could be achieved using an algal treatment system with minimum potential ecotoxicity.

Abstract A recent proposed dual-fuel combustion mode, intelligent charge compression ignition (ICCI), realizes the high-efficiency and clean combustion by organizing continuous stratification in a wide range of engine load. The paper investigated the performance of alcohol blended gasoline as low-reactivity fuel (LRF) in ICCI combustion mode. Pure ethanol named E100 was also tested as LRF for comparison. To emphasize the differences of LRF properties and exclude the effect of the heat release phasing, the diesel injection timing was adjusted to maintain the same combustion phasing (CA50) at various LRF ratios under medium load. The results showed that E100 and E85 (ethanol ratio in gasoline-ethanol blend) promoted the degree of homogeneous combustion and eradicated soot emissions despite a slight increase of NOx. The maximum indicated thermal efficiency (ITE) was over 51.1% using E85, followed by 50.5% of E50. The perfect substitution ratio at the maximum ITE decreased from more than 80% to about 65% when increasing the ethanol ratio in LRF from 10% to 100%. The unregulated emissions such as aldehydes, ethylene, and methane, produced from incomplete combustion of ethanol were inhabited by E85, while the formation of toluene attributed to the appropriate carbon chain length of gasoline diminished when using E85 and E100.

Abstract Perforated wavy fin is a promising type of fin to improve the comprehensive performance of a heat pump type air conditioners (HPAC) which should work with high efficiencies at both frosting and non-frosting conditions. The purpose of this study is to propose a comprehensive performance model of perforated wavy fins for the fin design of HPACs. The comprehensive performance model of perforated wavy fins is established is established for analyzing the total heat transfer performances (UA) at both frosting and non-frosting conditions, and a novel frosting model is developed to predict the effect of perforated wavy geometries on frost performance. The optimal fin geometries are figured out based on the query charts plotted by the comprehensive performance model. A practical perforated wavy fin is designed and manufactured, and an experimental validation on the comprehensive performance model as well as the performance of proposed fin has been conducted. The experimental validation shows that the predicted results of UA and frost morphology are highly in accordance with the experimental data; and the heat transfer capacities of the perforated wavy fin at the frosting and the non-frosting conditions are 4.1% and 8.9% higher than those of the traditional wavy fin, respectively.

Abstract Effusion cooling has been recognized as the next generation of cooling technologies for gas turbine engines. Concurrent effusion cooling configurations generally consist of a large number of film cooling holes to form full coverage coolant films on the protected surfaces. Coolant superposition effect consequently became a dominating factor for effusion cooling, and increased the difficulty to correlate the effectiveness with geometric parameters. This study proposed a machine learning approach using the convolution modeling method to predict the local adiabatic cooling effectiveness for effusively cooled surfaces. The model was trained by the numerical simulation data of several regular film cooling hole arrays, then validated by the data of randomly distributed film cooling hole rows. This model utilized convolution calculations in the regression process and successfully reconstructed the cooling effectiveness distribution for the entire surfaces. Results showed a good accuracy for both the training group and the validation group. Additionally, the convolution kernel of the model visualized the effect of coolant superposition by quantifying the contribution of a neighbor coolant ejection to the target location. This machine learning approach could serve as a strong tool to regress the adiabatic cooling effectiveness effusion cooling. Additional capability of this method could be exploited in other film cooling sections in turbine engines, including combustors liners, turbine blades and turbine endwall.

Ferrocene was introduced as a solid additive in organic solar cells (OSCs). The use of ferrocene provides PM6:Y6 based device with improved performance and stability, demonstrating its great potential in the fabrication of efficient and stable OSCs.

Abstract A continuous heat recovery adsorption heat pump prototype using actived carbon–methanol pair has been developed. A lot of experiments have been carried out in order to realize good performance of the system. After analysis of these experimental data, it is seen that operating process of the system, which is shown in p–t–x diagram of the real cycle and temperature rise and drop curves of adsorber, is related to adsorption and desorption capacity. If these relations are realized, the degree of adsorption and desorption process can be judged. In this paper, the relation between adsorption and desorption capacity of adsorber and p–t–x diagram of the real cycle are analyzed. Meanwhile, the relation between adsorption and desorption capacity of adsorber and temperature rise and drop curves of adsorber are also discussed. This work has laid a foundation for optimization of cycle time and cycle process.