| 21. |
- Yu, Y. F., et al.
(författare)
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Compound climate extremes in China: Trends, causes, and projections
- 2023
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Ingår i: Atmospheric Research. - : Elsevier BV. - 0169-8095. ; 286
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Tidskriftsartikel (refereegranskat)abstract
- Human society and ecosystems are impacted by climate extremes more than by climate averages. In contrast with climate extremes that are driven by individual climatic variables, compound climate extremes stem from a combination of multiple climatic drivers and usually lead to more severe risks than the former extremes do. The influences of the drivers for compound climate extremes are strengthening under global warming. Firstly, this review details the development of the definition of compound climate extremes over recent years and describes different types of events, such as compound drought and heatwave extremes (CDHEs), compound day and night heat extremes (CDNHEs), and compound flooding (CF). Secondly, historical trends in compound climate ex-tremes in China over the past half-century, and projections of future trends under different scenarios, are dis-cussed. For example, this study points out that a large part of China has experienced longer, stronger, and more frequent CDHEs than other parts of the country. CDHEs have followed a significantly increasing trend since the 1990s, and this trend is projected to strengthen further under different scenarios in the future. Thirdly, this study reviews different potential causes for compound climate extremes, including the internal variability of the climate system (e.g., land and atmosphere feedbacks, large-scale circulation patterns) and external anthropo-genic forcings (e.g., urbanization and anthropogenic emissions). In this study, we summarize risks from different perspectives by considering interactions between hazards, vulnerability, and exposure. Many studies show that risks to infrastructural damage and population exposure are projected to increase in the future, and that crop yields and ecosystem gross primary production are likely to reduce. Finally, we generalize our study and show that there is an urgent need for a comprehensive study of different combinations of compound events. We argue that it is important that we understand the key dynamic and thermal processes that are modulated by specific drivers and investigate the uncertainty in the projected variabilities for compound climate extremes. This re-quires interdisciplinary collaboration and will allow appropriate risk adaptation strategies to be developed. There has been great progress in research into compound climate extremes; however, an improved understanding of the mechanisms and risks is necessary as a theoretical basis for more effective climate adaptation policies.
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| 22. |
- Zhang, Hongguo, et al.
(författare)
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Cu-doped CaFeO3 perovskite oxide as oxygen reduction catalyst in air cathode microbial fuel cells
- 2022
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Ingår i: Environmental Research. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0013-9351 .- 1096-0953. ; 214
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Tidskriftsartikel (refereegranskat)abstract
- Cathode electrocatalyst is quite critical to realize the application of microbial fuel cells (MFCs). Perovskite oxides have been considered as potential MFCs cathode catalysts to replace Pt/C. Herein, Cu-doped perovskite oxide with a stable porous structure and excellent conductivity was successfully prepared through a sol-gel method. Due to the incorporation of Cu, CaFe0.9Cu0.1O3 has more micropores and a larger surface area, which are more conducive to contact with oxygen. Doping Cu resulted in more Fe3+ in B-site and thus enhanced its binding capability to oxygen molecules. The data from electrochemical test demonstrated that the as-prepared catalyst has good conductivity, high stability, and excellent ORR properties. Compared with Pt/C catalyst, CaFe0.9Cu0.1O3 exhibits a lower overpotential, which had an onset potential of 0.195 V and a half-wave potential of 0.224 V, respectively. CaFe0.9Cu0.1O3 displays an outstanding four-electron pathway for ORR mechanism and demonstrates superiors corrosion resistance and stability. The MFC with CaFe0.9Cu0.1O3 has a greater maximum power density (1090 mW m(-3)) rather than that of Pt/C cathode (970 mW m(-3)). This work demonstrated CaFe0.9Cu0.1O3 is an economic and efficient cathodic catalyst for MFCs.
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| 23. |
- Zhang, Xin, et al.
(författare)
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Enhancing the Photovoltaic Performance of Triplet Acceptors Enabled by Side-Chain Engineering
- 2021
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Ingår i: Solar RRL. - : WILEY-V C H VERLAG GMBH. - 2367-198X. ; 5:10
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Tidskriftsartikel (refereegranskat)abstract
- Triplet excitons have both longer lifetimes and diffusion lengths than singlet excitons due to the nature of triplet excitons, which is expected to increase the photocurrent and further improve the performance of organic solar cells (OSCs). However, the working mechanism of triplet excitons in OSCs is not clearly clarified. Therefore, it is urgent to develop new triplet acceptors for in-depth understanding. Herein, a series of acceptors (BTn-4Cl) are synthesized by fine-tuning of the side-chain branch positions. The generation of triplet excitons of BTn-4Cl is confirmed by the time-resolved photoluminescence (TRPL) spectra, magnetophotocurrent (MPC) experiment, and electron paramagnetic resonance (EPR) spectra. The effects of side-chain engineering on the optoelectronic properties, packing behaviors, energy losses, charge transport properties, spin lifetimes of triplet polarons, and blend film morphologies are systematically studied. These results show that D18:BT3-4Cl-based OSCs possess the best power conversion efficiency (PCE) of 17.31% due to lower energy losses, less recombination losses, more balanced charge carrier mobilities, longer spin-lattice (T-1) relaxation time, and more favorable morphology. This work enhances the understanding of the structure-property relationship for high-performance triplet acceptors.
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| 24. |
- Zhang, Yongping, et al.
(författare)
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Consensus aware manufacturing service collaboration optimization under blockchain based Industrial Internet platform
- 2019
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Ingår i: Computers & industrial engineering. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-8352 .- 1879-0550. ; 135, s. 1025-1035
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Tidskriftsartikel (refereegranskat)abstract
- To realize collaboration among distributed enterprises, manufacturing service collaboration on Industrial Internet platform is an efficient method. However, the low degree of participation resulted by the sense of distrust, dissatisfaction, and insecurity hinders the widely application of Industrial Internet platform. Therefore, a secure, trustworthy, and multi-user satisfied manufacturing service collaboration method is in urgent need. A blockchain based platform could be utilized to support collaboration among distributed participants to complete trustworthy transactions. In addition, in order to satisfy multiple users, there should be a suitable collaboration mechanism that allows interest-independent participants to fulfil their short/long-term expectations and guide them to a consensus. Based on the establishment of the underlying data and network layer of the blockchain, the collaboration optimization of manufacturing services based on consensus is proposed. By utilizing Memetic algorithm, both the long-term utility of providers and the short-term utility of consumers are combined to choose the optimal providers for the tasks. The providers are selected with higher satisfaction degree of consumers.
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| 25. |
- Zhang, Yongping, et al.
(författare)
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Long/short-term utility aware optimal selection of manufacturing service composition towards Industrial Internet platform
- 2019
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Ingår i: IEEE Transactions on Industrial Informatics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1551-3203 .- 1941-0050. ; 15:6, s. 3712-3722
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Tidskriftsartikel (refereegranskat)abstract
- As numerous Industrial Internet platforms emerge, manufacturing services are shared among multiple stakeholders more frequently than ever. The optimal selection of shared manufacturing service composition (MSC) should both promise the task completion and the stakeholders’ satisfaction. However, as commercial entities, stakeholders concentrate on not only the temporary benefits but also the long-term acquisitions. Most of the existing MSC problems neglect the stakeholders’ prospect on the manufacturing service sharing. This leads to the disappointment and dissatisfaction of the stakeholders with long-term expectations, who will abandon the participation in Industrial Internet platform. Therefore, the long/short-term preferences of various stakeholders should be satisfied and balanced. In this paper, the long/short-term preferences of three sides (provider, consumer, and operator) are discussed. And the models considering short-term utility of a consumer and long-term utility of providers, are established. The potential tasks assigned to providers are taken into account to estimate the long-term utility if the current task is accepted. Then, to solve the bi-objective optimization problem, an improved Non-dominated Sorting Genetic Algorithm-II algorithm, combining Tabu search and improved K-means mechanism, is proposed to find the optimal solution set. Finally, the effectiveness of the method is verified by the experimental results in terms of solution diversity, astringency and stability, in which a finding is further observed that the changes of consumers’ preferences have little impact on the long-term utility of providers.
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| 26. |
- Zhao, Sen, et al.
(författare)
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Expanding the mutation and phenotype spectrum of MYH3-associated skeletal disorders
- 2022
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Ingår i: NPJ genomic medicine. - : Nature Publishing Group. - 2056-7944. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Pathogenic variants in MYH3 cause distal arthrogryposis type 2A and type 2B3 as well as contractures, pterygia and spondylocarpotarsal fusion syndromes types 1A and 1B. These disorders are ultra-rare and their natural course and phenotypic variability are not well described. In this study, we summarize the clinical features and genetic findings of 17 patients from 10 unrelated families with vertebral malformations caused by dominant or recessive pathogenic variants in MYH3. Twelve novel pathogenic variants in MYH3 (NM_002470.4) were identified: three of them were de novo or inherited in autosomal dominant way and nine were inherited in autosomal recessive way. The patients had vertebral segmentation anomalies accompanied with variable joint contractures, short stature and dysmorphic facial features. There was a significant phenotypic overlap between dominant and recessive MYH3-associated conditions regarding the degree of short stature as well as the number of vertebral fusions. All monoallelic variants caused significantly decreased SMAD3 phosphorylation, which is consistent with the previously proposed pathogenic mechanism of impaired canonical TGF-β signaling. Most of the biallelic variants were predicted to be protein-truncating, while one missense variant c.4244T>G,p.(Leu1415Arg), which was inherited in an autosomal recessive way, was found to alter the phosphorylation level of p38, suggesting an inhibition of the non-canonical pathway of TGF-β signaling. In conclusion, the identification of 12 novel pathogenic variants and overlapping phenotypes in 17 affected individuals from 10 unrelated families expands the mutation and phenotype spectrum of MYH3-associated skeletal disorders. We show that disturbances of canonical or non-canonical TGF-β signaling pathways are involved in pathogenesis of MYH3-associated skeletal fusion (MASF) syndrome.
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| 27. |
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| 28. |
- Zhou, T. J., et al.
(författare)
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Understanding and building upon pioneering work of Nobel Prize in Physics 2021 laureates Syukuro Manabe and Klaus Hasselmann: From greenhouse effect to Earth system science and beyond
- 2022
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Ingår i: Science China-Earth Sciences. - : Springer Science and Business Media LLC. - 1674-7313 .- 1869-1897. ; 65
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Forskningsöversikt (refereegranskat)abstract
- The Nobel Prize in Physics 2021 was awarded jointly to Syukuro Manabe, Klaus Hasselmann, and Giorgio Parisi for their groundbreaking contributions to our understanding of complex systems. This is the first time that climate scientists were awarded the Nobel Physics Prize. Here, we present the evolution of climate science in the past similar to 200 years and highlight the landmarks of the developments in advancing our understanding of climate change, placing the pioneering contributions of Manabe and Hasselmann into a historical perspective. The backbone of modern climate science is further discussed in the context of the development of the discipline from the discovery of the greenhouse effect to the formation of Earth system science. Perspectives on the future development of climate science are also presented.
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| 29. |
- Bu, Lulei, et al.
(författare)
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Upstream Evaporation is the Key to Extreme Summertime Heat Stress in North China
- 2024
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Ingår i: EARTH SYSTEMS AND ENVIRONMENT. - 2509-9426 .- 2509-9434.
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Tidskriftsartikel (refereegranskat)abstract
- Humidity plays a critical role in amplifying temperature impact, leading to reduced heat dissipation efficiency and severe heat stress in humans. In the specific context of North China, this study explored different sensitivities of extreme heat stress (measured by wet-bulb temperature, TW) to humidity and temperature, and analyzed the influence of upstream variables on extreme heat stress. It is found that in the past four decades, extreme heat stress in North China increased rapidly at a maximum rate of over 0.4 celcius/decade, accompanied by the influence of humidity on extreme heat stress surpasses that of temperature. Even slight fluctuations in humidity can result in substantial variations in heat stress levels, unlike equivalent changes in temperature. This study is the first to find that for extreme heat stress, changes in temperature can only increase TW by up to 0.5 celcius, while increase in humidity can increase TW by 3 celcius. Notably, both humidity and temperature begin to rise approximately three days prior to extreme days, coinciding with intensified humidity transport and temperature advection from the upstream region. This study is also the first to find that intensified humidity transport is primarily driven by remarkably high evaporation originating from the western extension of the Northwest Pacific Subtropical High, while the strengthened temperature advection stems from a north-south temperature gradient during extreme days. This mechanism, wherein upstream variables impact downstream conditions, holds significant value for accurate prediction and timely response strategies.
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| 30. |
- Cai, Ziyi, et al.
(författare)
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Assessing Arctic wetting: Performances of CMIP6 models and projections of precipitation changes
- 2024
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Ingår i: Atmospheric Research. - 0169-8095. ; 297
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Tidskriftsartikel (refereegranskat)abstract
- The Arctic region is experiencing a notable increase in precipitation, known as Arctic wetting, amidst the backdrop of Arctic warming. This phenomenon has implications for the Arctic hydrological cycle and numerous socio-ecological systems. However, the ability of climate models to accurately simulate changes in Arctic wetting has not been thoroughly assessed. In this study, we analyze total precipitation in the Arctic using station data, multiple reanalyses, and 35 models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6). By employing the moisture budget equation and an evaluation method for model performance with ERA5 reanalysis as a reference, we evaluated the models' capability to reproduce past Arctic wetting patterns. Our findings indicate that most reanalyses and models are able to replicate Arctic wetting. However, the CMIP6 models generally exhibit an overestimation of Arctic wetting during the warm season and an underestimation during the cold season from 1979 to 2014 when compared to the ERA5 reanalysis. Further investigation reveals that the overestimation of wetting during the warm season is largest over the Arctic Ocean's northern part, specifically the Canadian Arctic Archipelago, and is associated with an overestimation of atmospheric moisture transport. Conversely, the models significantly underestimate wetting over the Barents-Kara Sea during the cold season, which can be attributed to an underestimation of evaporation resulting from the models' inadequate representation of sea ice reduction in that region. The models with the best performance in simulating historical Arctic wetting indicate a projected intensification of Arctic wetting, and optimal models significantly reduce uncertainties in future projections compared to the original models, particularly in the cold season and oceanic regions. Our study highlights significant biases in the CMIP6 models' simulation of Arctic precipitation, and improving the model's ability to simulate historical Arctic precipitation could reduce uncertainties in future projections.
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