| 1. |
- Ghan, Steven, et al.
(författare)
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Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 113:21, s. 5804-5811
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Tidskriftsartikel (refereegranskat)abstract
- A large number of processes are involved in the chain from emissions of aerosol precursor gases and primary particles to impacts on cloud radiative forcing. Those processes are manifest in a number of relationships that can be expressed as factors dlnX/dlnY driving aerosol effects on cloud radiative forcing. These factors include the relationships between cloud condensation nuclei (CCN) concentration and emissions, droplet number and CCN concentration, cloud fraction and droplet number, cloud optical depth and droplet number, and cloud radiative forcing and cloud optical depth. The relationship between cloud optical depth and droplet number can be further decomposed into the sum of two terms involving the relationship of droplet effective radius and cloud liquid water path with droplet number. These relationships can be constrained using observations of recent spatial and temporal variability of these quantities. However, we are most interested in the radiative forcing since the preindustrial era. Because few relevant measurements are available from that era, relationships from recent variability have been assumed to be applicable to the preindustrial to present-day change. Our analysis of Aerosol Comparisons between Observations and Models (AeroCom) model simulations suggests that estimates of relationships from recent variability are poor constraints on relationships from anthropogenic change for some terms, with even the sign of some relationships differing in many regions. Proxies connecting recent spatial/temporal variability to anthropogenic change, or sustained measurements in regions where emissions have changed, are needed to constrain estimates of anthropogenic aerosol impacts on cloud radiative forcing.
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| 2. |
- Zhang, Shipeng, et al.
(författare)
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On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models
- 2016
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:5, s. 2765-2783
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Tidskriftsartikel (refereegranskat)abstract
- Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (omega(500)), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascent (omega(500)aEuro-aEuro parts per thousand < aEuro-a'25 hPa day(-1)) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is close to that in subsidence regimes, which indicates that regimes with strong large-scale ascent are as important as stratocumulus regimes in studying AIE. It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm day(-1)) contributes the most to the total aerosol indirect forcing (from 64 to nearly 100 %). Results show that the uncertainty in AIE is even larger within specific dynamical regimes compared to the uncertainty in its global mean values, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.
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| 3. |
- Luo, Jing, et al.
(författare)
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Strong and Multifunctional Lignin/Liquid Metal Hydrogel Composite as Flexible Strain Sensors
- 2024
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Ingår i: ACS Sustainable Chemistry & Engineering. - 2168-0485. ; 12:18, s. 7105-7114
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Tidskriftsartikel (refereegranskat)abstract
- Conductive hydrogel is a promising material for flexible sensors due to its good electrical conductivity, adhesion, and high sensitivity. However, the challenge of integrating conductive fillers like liquid metals lies in their poor interface compatibility, which adversely affects their mechanical strength and lifespan. Addressing the challenge of achieving both mechanical strength and conductivity, this study harnessed 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-oxidized lignin to form a stable interface between the liquid metal (LM) and the hydrogel system. Furthermore, this innovation (lignin-LM) facilitates the free radical polymerization of acrylic acid (PAA) at room temperature, resulting in conductive hydrogels. These hydrogels demonstrated excellent self-healing, adhesive, tensile, and antibacterial properties, alongside high strain sensing accuracy and stable electrical output in flexible sensor applications. In conclusion, the PAA-Lignin-LM hydrogel holds excellent promise for wearable, flexible electronic products, introducing a novel approach for the high-value utilization of lignin.
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| 4. |
- Wu, Xinchen, et al.
(författare)
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Core-satellite nanoassembly system with aptamer-conjugated Au@Ag nanoparticles for SERS detection of patulin in apples
- 2024
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Ingår i: Food Control. - : Elsevier. - 0956-7135 .- 1873-7129. ; 159
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Tidskriftsartikel (refereegranskat)abstract
- Patulin (PAT), a major contaminant in apples, poses a huge threat to human health as well as the economic sector. There is an urgent need to develop a sensitive, selective, and fast-responsive method to detect PAT in apples. However, one of the main challenges is overcoming the interferences of complex food matrices. In this study, we developed a highly sensitive competitive SERS sensor based on plasmonic nanoparticles modified by aptamers. The study utilized the formation of nanocomposites through aptamer-modified Au@Ag nanoparticles (NPs) and gold nano-stars (AuNSs) to induce high-intensity Raman signals from the SERS tag. Subsequently, in the presence of PAT, the nanocomposites underwent decomposition, evident through the significant decrease in SERS intensity. According to the standard curve established in this study, the detection limit was 0.0281 ng/mL. The competitive sensor was applied to spiked apple fruit and juice samples, indicating a recovery rate ranging from 91.98% to 102.94%. The excellent analytical performances and high sensitivity observed suggest the potential of the plasmonic nanocomposite sensing strategy in detecting PAT in real matrices.
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| 5. |
- Xie, Shipeng, et al.
(författare)
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Non-Blind Image Deblurring Method by the Total Variation Deep Network
- 2019
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 37536-37544
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Tidskriftsartikel (refereegranskat)abstract
- There are a lot of non-blind image deblurring methods, especially with the total variation (TV) model-based method. However, how to choose the parameters adaptively for regularization is a major open problem. We proposed a very novel method that is based on the TV deep network to learn the best parameters adaptively for regularization. We used deep learning and prior knowledge to set up a TV-based deep network and calculate the parameters of regularization, such as biases and weights. Therefore, we used the idea of a deep network to update these parameters automatically to avoid sophisticated calculations. Our experimental results by our proposed network are significantly better than several other methods, in respect of detail retention and anti-noise performance. At the same time, we can achieve the same effect with a minimum number of training sets, thus speeding up the calculation.
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| 6. |
- Xie, Shipeng, et al.
(författare)
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Scatter Artifacts Removal Usings Using Learning-Based Method for CBCT in IGRT System
- 2018
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 6, s. 78031-78037
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Tidskriftsartikel (refereegranskat)abstract
- Cone-beam-computed tomography (CBCT) has shown enormous potential in recent years, but it is limited by severe scatter artifacts. This paper proposes a scatter-correction algorithm based on a deep convolutional neural network to reduce artifacts for CBCT in an image-guided radiation therapy (IGRT) system. A two-step registration method that is essential in our algorithm is implemented to preprocess data before training. The testing result on real data acquired from the IGRT system demonstrates the ability of our approach to learn artifacts distribution. Furthermore, the proposed method can be applied to enhance the performance on such applications as dose estimation and segmentation.
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| 7. |
- Xue, Shanshan, et al.
(författare)
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A film-like SERS aptasensor for sensitive detection of patulin based on GO@Au nanosheets
- 2024
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Ingår i: Food Chemistry. - : Elsevier. - 0308-8146 .- 1873-7072. ; 441
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Tidskriftsartikel (refereegranskat)abstract
- Patulin (PAT) commonly contaminates fruits, posing a significant risk to human health. Therefore, a highly effective and sensitive approach in identifying PAT is warranted. Herein, a SERS aptasensor was constructed based on a two-dimensional film -like structure. GO@Au nanosheets modified with SH-cDNA were employed as capture probes, while core -shell Au@Ag nanoparticles modified with 4 -MBA and SH-Apt were utilized as signal probes. Through the interaction between capture probes and signal probes, adjustable hotspots were formed, yielding a significant Raman signal. During sensing, the GO@Au-cDNA competitively attached to Au@AgNPs@MBA-Apt, resulting in an inverse relationship between PAT levels and SERS intensity. The acquired results exhibited linear responses to PAT within the range of 1-70 ng/mL, with a calculated limit of detection of 0.46 ng/mL. In addition, the SERS aptasensor exhibited satisfactory recoveries in apple samples, which aligned closely with HPLC. With high sensitivity and specificity, this method holds significant potential for PAT detection.
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