110 results on '"Linfei Li"'
Search Results
2. Advances in probing single biomolecules: From DNA bases to glycans
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Baofei Hou, Teng Zhang, Huixia Yang, Xu Han, Liwei Liu, Linfei Li, Cesare Grazioli, Xu Wu, Nan Jiang, and Yeliang Wang
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atomic‐scale probing ,biomolecules ,scanning probe microscopy ,structure ,visualization ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Abstract Imaging biomolecules in real space is crucial for gaining a comprehensive understanding of the properties and functions of biological systems at the most fundamental level. Among the various imaging techniques available for biomolecules and their assembled nanostructures, scanning probe microscopy (SPM) provides a powerful and nondestructive imaging option. SPM is unique in visualizing intrinsically disordered biomolecules at the nanometer scale (e.g., glycans). This review highlights recent achievements in studying biomolecules using SPM technique, focusing on DNA bases, amino acids, proteins, and glycans. The atomic‐level analysis of biomolecules made possible by SPM allows for a more accurate definition of the local structure–property relationship. High‐resolution SPM imaging of single biomolecules offers a new way to study basic processes of life at the molecular level.
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- 2023
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3. Effects of belite incorporation on mechanical and microstructural properties of OPC mortars cured under carbonation condition
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Hongfang Sun, Fengjiao Yu, Shuqin Liu, Xiaogang Zhang, Feng Xing, Wei Liu, Linfei Li, and Jie Ren
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Belite incorporation ,Carbonation curing ,Interfacial transition zone ,Mechanical strengths ,Mining engineering. Metallurgy ,TN1-997 - Abstract
This study investigates the effects of various dosages of belite replacing ordinary Portland cement (OPC) on properties of OPC binders using carbonation curing. Mechanical strength was examined, pore-related test and microstructural/mineralogical analyses including water absorption, scanning electron microscopy (SEM), thermogravimetric analysis and 29Si nuclear magnetic resonance (29Si-NMR) were carried out. Extra attention was paid on the changes in the thickness and porosity of interfacial transition zone (ITZ) of mortars. Compared to normal curing, carbonation curing increased the compressive strength of all mortar mixes, especially given a longer period of curing and/or with belite addition. The greatest increase (73.18%) in the compressive strength was seen in the specimen with 35% of belite after 28 days of carbonation curing compared its peer under normal curing condition. Besides, specimens with 5% and 15% belite obtained higher flexural strength than that of the control after 7 and 28 days of carbonation curing. Carbonation curing led to about 92.75% increment in the flexural strength of the specimen with 15% belite. Regardless of curing conditions, in most cases, belite modified mortars had higher fractural toughness, probably due to the formation of more C–S–H gels instead of Portlandite. Compressive and flexural strength are more sensitive towards the thickness of ITZ than its porosity and carbonation curing strengthened this sensitivity. Carbonation curing densified the bulk OPC binders, especially after a long period of curing incorporated with belite. Microstructural analyses indicate that although in general belite hinders the hydration process of OPC, a suitable amount (5 wt%) improved the hydration degree of OPC when cured in carbonation environment. The polymerization degree of C–S–H gels could be enhanced when belite is added irrespective of curing conditions.
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- 2023
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4. Sodium butyrate reduces ammonia production in the cecum of laying hens by regulating ammonia-producing bacteria
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Shuo Liu, Jiaxin Hu, Linfei Li, Sicheng Xing, Yiwen Yang, and Xindi Liao
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laying hen ,cecum ,ammonia (NH3) ,sodium butyrate ,ammonia-producing bacteria ,Animal culture ,SF1-1100 - Abstract
ABSTRACT: Sodium butyrate is a commonly used feed additive and can reduce ammonia (NH3) emissions from laying hens, but the mechanism of this effect is unknown. In this study, the sodium butyrate and cecal content of Lohmann pink laying hens were measured, and in vitro fermentation experiments and NH3-producing bacteria coculture experiments were carried out to explore the relationship between NH3 emissions and its associated microbiota metabolism. Sodium butyrate was found to significantly reduce NH3 emission from the cecal microbial fermentation of Lohmann pink laying hens (P < 0.05). The concentration of NO3−-N in the fermentation broth of the sodium butyrate-supplemented group increased significantly, and the concentration of NH4+-N decreased significantly (P < 0.05). Moreover, sodium butyrate significantly reduced the abundance of harmful bacteria and increased the abundance of beneficial bacteria in the cecum. The culturable NH3-producing bacteria consisted mainly of Escherichia and Shigella, such as Escherichia fergusonii, Escherichia marmotae and Shigella flexnerii. Among them, E. fergusonii had the highest potential for NH3 production. The coculture experiment showed that sodium butyrate can significantly downregulate the expression of the lpdA, sdaA, gcvP, gcvH and gcvT genes of E. fergusonii (P < 0.05), thus reducing the NH3 emission produced by the bacteria during metabolism. In general, sodium butyrate regulated NH3-producing bacteria to reduce NH3 production in the cecum of laying hens. These results are of great significance for NH3 emission reduction in the layer breeding industry and for future research.
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- 2023
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5. Chemically identifying single adatoms with single-bond sensitivity during oxidation reactions of borophene
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Linfei Li, Jeremy F. Schultz, Sayantan Mahapatra, Zhongyi Lu, Xu Zhang, and Nan Jiang
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Science - Abstract
Here, the authors report the use of ultrahigh vacuum tip-enhanced Raman spectroscopy to characterize the oxidation processes of monolayer borophene with atomic-scale resolution and single-bond sensitivity, demonstrating the potential of the technique for probing the local chemistry of surface adsorbates on low-dimensional materials.
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- 2022
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6. Sustainable Agriculture in the Face of Climate Change: Exploring Farmers’ Risk Perception, Low-Carbon Technology Adoption, and Productivity in the Guanzhong Plain of China
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Linfei Li and Yanfen Huang
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sustainable agriculture ,low carbon agricultural technology ,risk perception ,loss aversion ,Ordered Probit ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Agriculture is a significant contributor to global greenhouse gas emissions, and reducing carbon emissions in this sector is essential for mitigating global warming. To achieve China’s targets of carbon peak by 2030 and carbon neutrality by 2060, promoting low-carbon agricultural technology (LCAT) is fundamental. This study examines the impact of farmers’ risk perception on LCAT adoption behavior and its productivity effects with the Ordered Probit regression method, using micro survey data from 531 farmers in Shaanxi Province, China. The results show that farmers with stronger risk perceptions were more likely to adopt LCAT, based on their loss aversion characteristics. Additionally, farmers’ perceptions of yield, market, and climate risks positively influence the adoption of LCAT, with market risk perception having the strongest effect. Adopting LCAT has significant production and spillover effects, improving the output rate of farmers’ operating farmland and neighboring plots by 2.4% and 1.2%, respectively, for each additional measure adopted. This study contributes to the perception and loss aversion literature by examining farmers’ adoption of low-carbon agricultural practices. This study sheds light on the importance of risk perception in the adoption of sustainable agricultural practices and can inform policies aimed at promoting the adoption of LCAT for achieving sustainable agriculture and mitigating climate change, highlighting the crucial role of sustainable environmental management in the agricultural sector.
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- 2023
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7. Organic Fertilizer Application Mediates Tomato Defense Against Pseudomonas syringae pv. Tomato, Possibly by Reshaping the Soil Microbiome
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Feng Huang, Chunhao Mo, Linfei Li, Jingling Shi, Yiwen Yang, and Xindi Liao
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organic fertilizers ,foliar pathogens ,microbial diversity ,tomato ,disease suppression ,biological control ,Microbiology ,QR1-502 - Abstract
Bacterial speck caused by Pseudomonas syringae pv. tomato is a serious foliar disease on tomato. However, it is still unknown how organic fertilizers application mediates plant defense against foliar pathogens by altering the composition of the soil microbial community. We conducted a 2-cycle pot experiment involving chemical and organic fertilizers and tracked tomato foliar pathogen incidence. Using microbiome sequencing, we then compared the differences in bulk and rhizosphere microbial communities. The results showed that, compared with soils amended with chemical fertilizer, soils amended with organic fertilizer gradually and significantly presented a reduction in tomato foliar disease, and the bacterial richness and diversity significantly increased. Moreover, the bacterial and fungal compositions of the bulk soil and rhizosphere soil of the organic fertilizer and chemical fertilizer treatments were different from each other. More importantly, the abundance of some potentially beneficial bacteria, such as Luteolibacter, Glycomyces, Flavobacterium, and Flavihumibacter, increased in the organic fertilizer-amended soil, and these genera were significantly negatively correlated with the incidence of tomato foliar disease. These results suggest that organic fertilizers can alter the taxonomy of the soil microbiome and that some specific beneficial microbial communities may play an important role in reducing the infection of foliar pathogens by inducing plant resistance.
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- 2022
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8. Changes of milk-specific IgE and serum total IgE in infants with eczema induced by milk allergen
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Ge QIAN, Wu GUO, Dengting WU, and Linfei LI
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eczema ,infant ,milk-specific ige ,serum ige ,Dermatology ,RL1-803 - Abstract
Objective: To study the changes of milk-specific IgE and total serum IgE in infants with severe eczema induced by milk allergy at the different ages. Methods: Totally 57 infants with severe eczema induced by milk allergy were recruited. Both milk-specific IgE and serum IgE were measured, and the degrees of lesion severity were assessed at the beginning and end of the study. The study period was 30 months. Participants were required to avoid milk consumption during the investigation. Results: Among 57 patients, the average SCORAD score at the end of the observation was significantly lower than that at the beginning of the observation (6.17±5.03 vs 56.98±10.24, t=29.08, P
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- 2021
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9. Study the Mechanical Properties of Geopolymer under Different Curing Conditions
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Jinliang Liu, Xiaohui Shi, Guanhua Zhang, and Linfei Li
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FA-GGBS based geopolymer ,curing conditions ,orthogonal test ,mechanical properties ,microscopic analysis ,Mineralogy ,QE351-399.2 - Abstract
The geopolymer is an environmentally friendly and high-performance material. Nowadays, how to improve the degree of the geopolymer’s reaction and enhance its mechanical properties has become a hot topic. This study used orthogonal tests to design the precursor mixing ratio, considering GGBS content (A), water/binder ratio (B), and alkaline activator modulus (C). The fly ash (FA) ground granulated blast furnace slag (GGBS)-based geopolymers were cured under two standard curing conditions: 40 °C under water and 40 °C in the oven. Then, the influence of these factors on the mechanical properties of geopolymers under different curing conditions was summarized. The contribution of each factor was ranked, which was used to find out the most sensitive factors affecting the mechanical properties. Taking the 7 days and 28 days of compressive strength and flexural strength of the geopolymer specimens as the evaluation criteria, the optimum ratio method for preparing geopolymers was obtained. Then, the prediction model of compressive strength under different curing conditions was established. SEM and XRD were used to analyze the microstructure and hydration products of the samples. The test results showed that the optimum ratio of FA-based geopolymers varied under different curing conditions. The GGBS content was the key factor in determining the mechanical properties. The heat curing condition was the best curing condition, the 28-day compressive strength could reach 76.3 MPa, and the 28-day flexural strength could reach 7.4 MPa. The prediction models established for compressive strength under different curing conditions had high accuracy. The specimens under the best curing conditions exhibited a dense internal microstructure and the presence of C-S-H gels, C-A-S-H gels, and N-A-S-H gels.
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- 2023
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10. Effect of Biochar on Soil-Water Characteristics of Soils: A Pore-Scale Study
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Xin Chen, Linfei Li, Xiaofeng Li, Jianyu Kang, Xiang Xiang, Honglian Shi, and Xingwei Ren
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biochar-amended soils ,pore size distribution ,soil water retention curve ,nuclear magnetic resonance ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
The mechanical and hydraulic properties of soils are largely governed by their soil-water characteristics, which are influenced by factors such as pore size distribution (PSD). While biochar is commonly used as an additive to alter soil properties, its effect on PSD and the soil water retention curve (SWRC) at the pore scale remains unclear. This study aims to investigate the impact of biochar on PSD and SWRC in soils of different types. The study utilized nuclear magnetic resonance (NMR) and the filter paper method to obtain the particle size distribution (PSD) curve and soil water retention curve (SWRC) of various types of soils, ranging from fine-grained to coarse-grained, with different amounts of biochar. The results and discussion revealed that the impact of biochar on soil PSD and SWRC varied depending on the soil type and biochar content. In fine-grained soils, the addition of 8% biochar resulted in the greatest decrease in mesopore size and percentage, while in medium-grained soils, 6% biochar had the most significant effect, and in coarse-grained soils, the optimum biochar content was 2%. At low suction states, the addition of 8% and 2% biochar improved the water retention of fine-grained and medium-grained soils, respectively, but had little effect on coarse-grained soils. Overall, the effect of biochar on soil-water characteristics was non-monotonic and depended on the relative sizes of biochar and soil particles. Therefore, selecting the optimum biochar-to-soil ratio requires careful consideration of these factors.
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- 2023
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11. Neuronal Nitric Oxide Synthase Knockdown Within Basolateral Amygdala Induces Autistic-Related Phenotypes and Decreases Excitatory Synaptic Transmission in Mice
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Xiaona Wang, Chao Gao, Yaodong Zhang, Jinxiu Xu, Quanfeng Fang, Lingshan Gou, Zhigang Yang, Daoqi Mei, Leiming Liu, Linfei Li, Jing Liu, Huichun Zhang, and Yinsen Song
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neuronal nitric oxide synthase ,autism spectrum disorder ,interneuron ,synaptic transmission ,basolateral amygdala ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by deficits in communication, impaired social interaction, and repetitive or restricted interests and behaviors. We have recently shown that neuronal nitric oxide synthase (nNOS) expression was reduced in the basolateral amygdala of mice after postnatal valproic acid exposure. However, the specific role of nNOS downregulation in mice remains to be elucidated. Herein, we investigated the behavioral alternations of naive mice with a recombinant adeno-associated virus (rAAV)-mediated knockdown of nNOS in a comprehensive test battery, including the social interaction, marble burying, self-grooming, and open field tests. Further, the electrophysiological and surface expression changes induced by nNOS deficiency of the basolateral amygdala in these animals were examined. Our results show that nNOS knockdown displayed typical symptoms of ASD-like behaviors, such as reduced social interaction and communication, elevated stereotypes, and anxiety in mice. Surprisingly, we found that nNOS knockdown exhibited greatly reduced excitatory synaptic transmission concomitant with the lower surface expression of GluN2B-containing N-methyl-D-aspartate receptors and postsynaptic density protein 95 in mice. These findings support a notion that dysregulation of nNOS might contribute to ASD-associated phenotypes, with disease pathogenesis most likely resulting from deficits in excitatory synaptic transmission.
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- 2020
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12. Dynamic Performance Improvement of Solenoid Screw-In Cartridge Valve Using a New Hybrid Voltage Control
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Zengguang Liu, Linfei Li, Daling Yue, Liejiang Wei, Chao Liu, and Xiukun Zuo
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digital hydraulic ,high speed on-off valve ,screw-in cartridge valve ,hybrid voltage control ,dynamic characteristic ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Digital hydraulic technology as an emergent and important branch of fluid power offers good prospects for intelligence, integration, and energy saving of hydraulic systems. The high-speed on-off valve (HSV) that is a critical component of digital hydraulics has the drawbacks of specific design, narrow scope of application and high price compared to the commercial solenoid screw-in cartridge valve (SCV) widely used in the hydraulic industry at present. In this paper, a hybrid voltage control strategy composed of the preloading voltage, positive pulse voltage, holding voltage and negative pulse voltage is proposed to enhance the dynamic characteristics of the SCV, which makes it meet the demands of the digital hydraulics and achieve the end of replacing the HSV. Based on the structural analysis of the SCV, a mathematical model of the SCV is deduced. Subsequently, the simulation model of the SCV is developed in AMESim and validated by experimental measurements. The effects of the different duty ratios of the preloading voltage and holding voltage on the dynamic characteristics of SCV are studied, and the dynamic responses of the SCV under the normal voltage, positive and negative pulse and hybrid voltage control strategies are compared. The simulation results indicate that the increment of the preload voltage duty ratio and the reduction of the holding voltage duty ratio are conducive for decreasing the total opening and closing time of the SCV, especially the opening delay and closing delay time. The hybrid voltage control proposed has a better effect in dynamic characteristics than the other two strategies, using which the total opening time of the SCV reduces by 74.24% (from 29.5 ms to 7.60 ms), and the total closing time is drastically squeezed by 92.06% (from 136 ms to 10.8 ms). This provides a technical reference for improving the dynamic response speed of SCVs and popularizing digital hydraulic technology.
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- 2022
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13. Direct observation of spin-layer locking by local Rashba effect in monolayer semiconducting PtSe2 film
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Wei Yao, Eryin Wang, Huaqing Huang, Ke Deng, Mingzhe Yan, Kenan Zhang, Koji Miyamoto, Taichi Okuda, Linfei Li, Yeliang Wang, Hongjun Gao, Chaoxing Liu, Wenhui Duan, and Shuyun Zhou
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Science - Abstract
Spin polarization in non-magnetic solids has mainly been limited to non-centrosymmetric materials. Here, the authors identify a helical spin texture in the centrosymmetric semiconductor platinum diselenide, and suggest it arises from a local dipole induced Rashba effect rather than the usual spin-splitting.
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- 2017
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14. The selective blocking of potentially catalytically active sites on surface-supported iron oxide catalysts
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Dairong Liu, Linfei Li, Buddhika S. A. Gedara, Michael Trenary, and Nan Jiang
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Materials Chemistry ,General Materials Science - Abstract
Selective growth of Pd and Pt on the edges of Au(111) supported FeO islands was observed. The complicated interfaces formed in selective growth raise a platform for the research of edge involved catalytic reactions.
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- 2023
15. Effects of TiO2-Modified RGO Composites on the Mechanical and Durability Properties of Ordinary Portland Cement Mortars
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Xiaoqiang Qi, Siyao Guo, Sulei Zhang, Tengteng Wang, Zhiqing Jia, Linfei Li, Lihai Zhang, and Jie Ren
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General Materials Science - Published
- 2022
16. Sustainable Agriculture in the Face of Climate Change: Exploring Farmers’ Risk Perception, Low-Carbon Technology Adoption, and Productivity in the Guanzhong Plain of China
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Huang, Linfei Li and Yanfen
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sustainable agriculture ,low carbon agricultural technology ,risk perception ,loss aversion ,Ordered Probit - Abstract
Agriculture is a significant contributor to global greenhouse gas emissions, and reducing carbon emissions in this sector is essential for mitigating global warming. To achieve China’s targets of carbon peak by 2030 and carbon neutrality by 2060, promoting low-carbon agricultural technology (LCAT) is fundamental. This study examines the impact of farmers’ risk perception on LCAT adoption behavior and its productivity effects with the Ordered Probit regression method, using micro survey data from 531 farmers in Shaanxi Province, China. The results show that farmers with stronger risk perceptions were more likely to adopt LCAT, based on their loss aversion characteristics. Additionally, farmers’ perceptions of yield, market, and climate risks positively influence the adoption of LCAT, with market risk perception having the strongest effect. Adopting LCAT has significant production and spillover effects, improving the output rate of farmers’ operating farmland and neighboring plots by 2.4% and 1.2%, respectively, for each additional measure adopted. This study contributes to the perception and loss aversion literature by examining farmers’ adoption of low-carbon agricultural practices. This study sheds light on the importance of risk perception in the adoption of sustainable agricultural practices and can inform policies aimed at promoting the adoption of LCAT for achieving sustainable agriculture and mitigating climate change, highlighting the crucial role of sustainable environmental management in the agricultural sector.
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- 2023
- Full Text
- View/download PDF
17. Chemical Characterization of a Three-Dimensional Double-Decker Molecule on a Surface via Scanning-Tunneling-Microscopy-Based Tip-Enhanced Raman Spectroscopy
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Sayantan Mahapatra, Jeremy F. Schultz, Linfei Li, Xu Zhang, and Nan Jiang
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General Energy ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2022
18. Controlling Localized Plasmons via an Atomistic Approach: Attainment of Site-Selective Activation inside a Single Molecule
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Xu Zhang, Linfei Li, Jeremy Schultz, Nan Jiang, and Sayantan Mahapatra
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Colloid and Surface Chemistry ,General Chemistry ,Biochemistry ,Catalysis - Abstract
Chemical reactions such as bond dissociation and formation assisted by localized surface plasmons (LSPs) of noble metal nanostructures hold promise in solar-to-chemical energy conversion. However, the precise control of localized plasmons to activate a specific moiety of a molecule, in the presence of multiple chemically equivalent parts within a single molecule, is scarce due to the relatively large lateral distribution of the plasmonic field. Herein, we report the plasmon-assisted dissociation of a specific molecular site (C-Si bond) within a polyfunctional molecule adsorbed on a Cu(100) surface in the scanning tunneling microscope (STM) junction. The molecular site to be activated can be selected by carefully positioning the tip and bringing the tip extremely close to the molecule (atomistic approach), thereby achieving plasmonic nanoconfinement at the tip apex. Furthermore, multiple reactive sites are activated in a sequential manner at the sub-molecular scale, and different sets of products are created and visualized by STM topography and density functional theory (DFT) modeling. The illustration of site-selective activation achieved by localized surface plasmons implies the realization of molecular-scale resolution for bond-selected plasmon-induced chemistry.
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- 2022
19. The hazard of earthquake and solution directions
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Linfei Li
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- 2023
20. Blockchain Promotes Collaborative Development of Fresh E-Commerce Supply Chain
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Wenying Zeng, Linfei Li, and Sijia Zeng
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- 2023
21. Direct evidence of two-dimensional electron gas-like band structures in hafnene
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Shaozhu Xiao, Meng Liu, Linfei Li, Jiatao Sun, Yeliang Wang, and Shaolong He
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General Materials Science ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics - Published
- 2021
22. Localized surface plasmon controlled chemistry at and beyond the nanoscale
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Sayantan Mahapatra, Dairong Liu, Chamath Siribaddana, Kai Wang, Linfei Li, and Nan Jiang
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General Medicine - Abstract
Gaining valuable insight into chemistry-related fields, such as molecular and catalytic systems, surface science, and biochemistry, requires probing physical and chemical processes at the sub-nanoscale level. Recent progress and advancements in nano-optics and nano-photonics, particularly in scanning near-field optical microscopy, have enabled the coupling of light with nano-objects using surface plasmons with sub-nanoscale precision, providing access to photophysical and photochemical processes. Herein, this review highlights the basic concepts of surface plasmons and recent experimental findings of tip-assisted plasmon-induced research works and offers a glimpse into future perspectives.
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- 2023
23. Influence of Potassium Supply and Harvest Time on Selected Growth, Physiology, and Quality Factors of Ephedra sinica Stapf
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Linfei Li, Jiayue Liu, Yunsheng Zhao, Siqi Li, Xueyan Fu, Fuying Mao, Anli Liu, and Nana Cen
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0106 biological sciences ,Potassium ,ved/biology.organism_classification_rank.species ,Soil Science ,chemistry.chemical_element ,Physiology ,Phenylalanine ,Plant Science ,Biology ,engineering.material ,01 natural sciences ,Dry weight ,medicine ,Proline ,Ephedrine ,Ephedra sinica ,ved/biology ,04 agricultural and veterinary sciences ,Pseudoephedrine ,chemistry ,040103 agronomy & agriculture ,engineering ,0401 agriculture, forestry, and fisheries ,Fertilizer ,Agronomy and Crop Science ,010606 plant biology & botany ,medicine.drug - Abstract
The present study aims to investigate the influences of potassium (K) supply and harvest time on selected growth, physiology and quality factors of Ephedra sinica Stapf (ESS). A field plot experiment was conducted under 10 levels of K supply (K1–K10, 0–538.3 kg ha−1). ESS was sampled randomly with uniform distribution locations of each plot on August 27 (H1), September 15 (H2), October 6 (H3), and October 27 (H4) in 2018. The late-harvested ESS had low SPAD value, peroxidase activity, cell membrane permeability, and high 10 cm stem weight, phenylalanine ammonia-lyase activity, free proline, ephedrine, total alkaloids, or flavonoids contents. The fertilizer dose of 59.8–239.3 kg ha−1 (K2-K5) increased the 10 cm stem weight, stem or root fresh and dry weights, the SPAD value, free proline content, peroxidase activity, reduced the root activity. The ephedrine, pseudoephedrine, total alkaloids, and flavonoids contents increased with the increase of K supply before K7 (358.9 kg ha−1). The harvest time influenced the increase of these quality factors resulting from one unit of K application. The harvested E. sinica in H3 increased the ephedrine content 85.97%, pseudoephedrine 21.53%, total alkaloids 38.02%, and total flavonoids 66.43%, compared with their average values of H1. The dose of 239.3 kg ha−1 (K5) reduced the ephedrine content 14.99%, pseudoephedrine 8.07%, total alkaloids 16.4%, and total flavonoids 28.71%, compared with K7, however increased the stem fresh and dry weight 163.21% and 125.70%, respectively. The late-harvested ESS had high contents of quality factors and good quality. The K dose of 239.3 kg ha−1 was appropriate for cultivated ESS high yield and quality accumulation.
- Published
- 2021
24. CRISPR-Based Approaches for Efficient and Accurate Detection of SARS-CoV-2
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Kangbo Liu, Lifeng Li, Weyland Cheng, Wancun Zhang, Pin Zhang, Fan Zhang, Linfei Li, Xianwei Zhang, and Zhidan Yu
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0301 basic medicine ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,diagnosis ,Specific detection ,Computer science ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Overview ,Clinical Biochemistry ,Computational biology ,03 medical and health sciences ,0302 clinical medicine ,Humans ,CRISPR ,Clustered Regularly Interspaced Short Palindromic Repeats ,030212 general & internal medicine ,Biochemistry, medical ,SARS-CoV-2 ,fungi ,Biochemistry (medical) ,COVID-19 ,030104 developmental biology ,COVID-19 Nucleic Acid Testing ,2019-nCoV ,Treatment time ,AcademicSubjects/MED00690 - Abstract
An outbreak of COVID-19, caused by infection with SARS-CoV-2 in Wuhan, China in December 2019, spread throughout the country and around the world, quickly. The primary detection technique for SARS-CoV-2, the reverse-transcription polymerase chain reaction (RT-PCR)–based approach, requires expensive reagents and equipment and skilled personnel. In addition, for SARS-CoV-2 detection, specimens are usually shipped to a designated laboratory for testing, which may extend the diagnosis and treatment time of patients with COVID-19. The latest research shows that clustered regularly interspaced short palindromic repeats (CRISPR)–based approaches can quickly provide visual, rapid, ultrasensitive, and specific detection of SARS-CoV-2 at isothermal conditions. Therefore, CRISPR-based approaches are expected to be developed as attractive alternatives to conventional RT-PCR methods for the efficient and accurate detection of SARS-CoV-2. Recent advances in the field of CRISPR-based biosensing technologies for SARS-CoV-2 detection and insights into their potential use in many applications are reviewed in this article.
- Published
- 2020
25. Shallowing interfacial carrier trap in transition metal dichalcogenide heterostructures with interlayer hybridization
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Jingsi Qiao, Wei Ji, Cong Wang, Xu Wu, Yan Shao, Linfei Li, Yeliang Wang, Liwei Liu, Zhong-Liu Liu, Hong-Jun Gao, Zhi-Li Zhu, and Zhixin Hu
- Subjects
Materials science ,business.industry ,Charge (physics) ,Heterojunction ,02 engineering and technology ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Condensed Matter::Materials Science ,Transition metal ,Electrode ,Optoelectronics ,General Materials Science ,Density functional theory ,Charge carrier ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Saturation (magnetic) ,Quantum tunnelling - Abstract
With the unique properties, layered transition metal dichalcogenide (TMD) and its heterostructures exhibit great potential for applications in electronics. The electrical performance, e.g., contact barrier and resistance to electrodes, of TMD heterostructure devices can be significantly tailored by employing the functional layers, called interlayer engineering. At the interface between different TMD layers, the dangling-bond states normally exist and act as traps against charge carrier flow. In this study, we propose a technique to suppress such carrier trap that uses enhanced interlayer hybridization to saturate dangling-bond states, as demonstrated in a strongly interlayer-coupled monolayer-bilayer PtSe2 heterostructure. The hybridization between the unsaturated states and the interlayer electronic states of PtSe2 significantly reduces the depth of carrier traps at the interface, as corroborated by our scanning tunnelling spectroscopic measurements and density functional theory calculations. The suppressed interfacial trap demonstrates that interlayer saturation may offer an efficient way to relay the charge flow at the interface of TMD heterostructures. Thus, this technique provides an effective way for optimizing the interface contact, the crucial issue exists in two-dimensional electronic community.
- Published
- 2020
26. Clinical, Biochemical and Molecular Characterizations of Patients With Glutaric Aciduria Type 1 in Henan Province, China
- Author
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Xinyun Zhu, Xiaole Li, Suna Liu, Min Ni, Yaqing Guo, Yizhuo Xu, Liting Jia, Linfei Li, and Dehua Zhao
- Abstract
Background: Glutaric acidemia type 1 (GA1) is a rare organic acid metabolism disorder resulted from the deficiency of glutaryl-CoA dehydrogenase (GCDH). There are few studies on GA1 in China. This article is designed to investigate the clinical, biochemical and molecular characterizations of patients with GA1 in Henan province, in order to get further understanding of this disease .Results: The incidence of neonatal GA1 in Henan population was 1/172483. All patients had increased glutarylcarnitine (C5DC), glutaric acid (GA) and 3-hydroxyglutaric acid (3-OH-GA) levels. Twenty mutations were discovered in 14 patients. Four of them were novel: c.523G>A (p.G175S), c.1297G>C (p.A433P), c.467G>A (p.G156D) and c.1125T>G (p.C375W). The most common mutation was c.1064G>A (p.R355H), of which the allelic frequency was 17.86% (5/28), following by c.1109T>C (p.L370P), c.648G>A (p.S216S), c.395G>A (p.R132Q) and c.938G>A (p.R313Q), which had the same allelic frequency 7.14% (2/28). 84.6%(11/13) patients displayed abnormal brain MRI findings, of which cerebral dysplasia and arachnid/ependyma cysts(38.5%,5/13) were most commonly. Clinical features varied widely from asymptomatic to severe encephalopathy. Patients diagnosed by newborn screening had better outcome. A strong correlation was discovered among increasing disability in motor, speech and cognitive function. There were statistical significance differences in motor function(p=0.024) and speech function (p=0.008), but no statistical significance difference in cognitive function (p=0.106) between NBS group and non-NBS group.Conclusions: Our study provided comprehensive information about GA1 in Henan population, including morbidity, clinical, biochemical, molecular and outcome features. The novel variants expanded the GCDH variant spectra. This work emphasize that professional management of NBS programs and experienced genetic metabolic disease experts will be very important and urgent.
- Published
- 2022
27. The two leading modes of winter clear-sky days over China and their formation mechanisms
- Author
-
Linfei Li, Rui Lu, Huiping Yan, Xiao Pan, Hui Tan, and Zhiwei Zhu
- Subjects
Arctic sea ice decline ,Atmospheric Science ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Anomaly (natural sciences) ,Rossby wave ,010502 geochemistry & geophysics ,01 natural sciences ,Arctic ice pack ,Latitude ,Troposphere ,Anticyclone ,Climatology ,Stratosphere ,Geology ,0105 earth and related environmental sciences - Abstract
Using gauge data during 1979–2013, the spatial and temporal characteristics of winter clear-sky days (CSDs) in China are investigated. The frequency of winter CSDs in China has two independent and significant modes, which account for 41% and 10% of the total variance, respectively. Based on evidence from observational analysis and numerical experiments, the formation mechanisms of these two leading modes are unraveled. The first mode is a homogenous mode with coherent year-to-year variation of CSDs over most parts of China, and is closely related to a large-scale cyclonic/anticyclonic anomaly over the Asian continent. Anomalous Indian Ocean SST and Arctic sea ice are responsible for the associated large-scale circulation anomalies via inducing a mid-to-high latitude Rossby wave train. The Indian Ocean SST warming can induce wave energy propagation upwards to the stratosphere and then northwards to the polar region, where it moves down to the troposphere and then travels southeastwards from the polar region to East Asia. Meanwhile, the decreased Arctic sea ice can directly induce a Rossby wave train emanating from the polar region that travels southeastwards into East Asia. These two factors jointly lead to a dominant equivalent barotropic cyclonic/anticyclonic anomaly over China, and in turn the homogenous pattern of winter CSDs in the region. The second mode is a seesaw mode with out-of-phase variations of CSDs between northern and southern China. This mode is closely related to a meridional dipole circulation anomaly pattern over the East Asian sector, which is generated by the so-called ‘Mega-ENSO’ SST anomaly over the Pacific Ocean. This Mega-ENSO SSTA pattern can induce convective heating/cooling over the tropical western Pacific, which further leads to the meridional dipole circulation anomaly pattern over the East Asian sector, resulting in the south-to-north seesaw mode of winter CSDs in China.
- Published
- 2020
28. Concentration of fifteen elements in herbaceous stems of Ephedra intermedia and influence of its growing soil
- Author
-
Siqi Li, Linfei Li, Fuying Mao, Nana Cen, Ruixia Yang, Anli Liu, Hong Sui, and Yunsheng Zhao
- Subjects
Plant domestication ,Ephedra ,lcsh:Medicine ,010501 environmental sciences ,01 natural sciences ,complex mixtures ,Article ,Environmental impact ,Soil ,Nutrient ,stomatognathic system ,Botany ,Cation-exchange capacity ,Plant ecology ,lcsh:Science ,0105 earth and related environmental sciences ,Rhizosphere ,Minerals ,Multidisciplinary ,biology ,Chemistry ,010401 analytical chemistry ,lcsh:R ,Soil chemistry ,Nutrients ,biology.organism_classification ,Humus ,0104 chemical sciences ,Trace Elements ,stomatognathic diseases ,Soil water ,Composition (visual arts) ,lcsh:Q ,Ephedra intermedia - Abstract
Mineral nutrients play important roles in the growth and metabolism of Ephedra intermedia, and are affected by soil factors. Fifteen elements were measured from wild E. intermedia as well as their growing soils using inductively coupled plasma mass spectroscopy to investigate the influences and characteristics of herb elements. The pH, cation exchange capacity, humus and soil mechanical composition were also determined in rhizosphere soils. Results showed that E. intermedia stems contained high N, low P concentrations in macronutrients and high Fe in micronutrients, and enriched N, S, Cl, P and Sr from soils. The 15 herb elements were affected by one or more soil factors, and K, P, Zn, Fe and Mn were important soil elements that influenced the mineral accumulation of E. intermedia. This study was useful for the artificial cultivation of wild E. intermedia.
- Published
- 2020
29. Methods to fabricate and recycle plasmonic probes for ultrahigh vacuum scanning tunneling microscopy‐based tip‐enhanced Raman spectroscopy
- Author
-
Linfei Li, Sayantan Mahapatra, Jeremy F. Schultz, and Nan Jiang
- Subjects
Materials science ,business.industry ,Tip-enhanced Raman spectroscopy ,law.invention ,symbols.namesake ,law ,symbols ,Optoelectronics ,General Materials Science ,Electrochemical etching ,Scanning tunneling microscope ,Raman spectroscopy ,business ,Spectroscopy ,Plasmon - Published
- 2020
30. A comparison between alkali-activated slag/fly ash binders prepared with natural seawater and deionized water
- Author
-
Jie Ren, Hongfang Sun, Qun Li, Zhenming Li, Xiaogang Zhang, Yanshuai Wang, Linfei Li, and Feng Xing
- Subjects
alkali-activated slag/fly ash ,microstructure ,Materials Chemistry ,Ceramics and Composites ,hydration kinetics ,mechanical properties ,seawater ,setting time - Abstract
In this research, the effects of natural seawater (SW) on the properties of alkali-activated slag/fly ash (AASF) are studied. AASF prepared with deionized water is set as the reference mixture. The results showed that the use of natural SW resulted in a prolonged setting time and lower heat release, but no obvious impact on the flowability of AASF specimens. The long-term compressive strength became higher when SW was used, whereas the corresponding flexural strength and fractural toughness turned lower. The use of SW induced the formation of new products that were not identified in the reference mixture, such as Cl–hydrocalumite and gypsum. In addition, it is evidenced that the dissolution of fly ash (FA) particles was significantly delayed with the incorporation of SW. All these results were related to the various ions introduced by the natural SW and their interactions with the alkaline activator as well as the precipitation of salts on slag and FA surfaces or in the matrix.
- Published
- 2022
31. Numerical study of Richtmyer–Meshkov instability of a flat interface driven by perturbed and reflected shock waves
- Author
-
Linfei Li, Tai Jin, Liyong Zou, Kun Luo, and Jianren Fan
- Subjects
Fluid Flow and Transfer Processes ,Mechanics of Materials ,Mechanical Engineering ,Computational Mechanics ,Condensed Matter Physics - Abstract
In this paper, the Richtmyer–Meshkov instability of a flat gas interface driven by perturbed and reflected shock waves is numerically investigated. The flat gas interface evolves into a “Λ”-shaped structure with a central N2 cavity and steps on both sides, due to the impaction of the perturbed shock wave. After the secondary collision of the reflected shock wave from the high-density region to the low-density region, the gas interface first undergoes phase inversion, and the “Λ” interface then evolves into a bubble and spike structure. Three cases of different Atwood numbers, N2/SF6, N2/Kr, and N2/CO2, are studied. The collision time and position of the reflected shock wave and the interface, the induced spikes, bubbles and gas mixing, are compared in detail. The formation of the spike and bubble is related to the RM instability developed by the collision of the reflected shock wave and the perturbed interface, in which the effect of baroclinic vorticity is highlighted. With the increase in the Atwood number, the density gradient and the baroclinic vorticity become larger, which induces more vortex along the interface. Kelvin Helmholtz unstable vortices are generated on the “legs” of the spikes due to shearing. The main spike structure is stretched and broken with the effect of the vortex, forming a turbulent mixing zone.
- Published
- 2023
32. The fate of antibiotic resistance genes and their association with bacterial and archaeal communities during advanced treatment of pig farm wastewater
- Author
-
Yiwen Yang, Linfei Li, Feng Huang, Xinwen Hu, Xinwei Cao, Jiandui Mi, Xindi Liao, and Sicheng Xing
- Subjects
Farms ,Environmental Engineering ,Bacteria ,Swine ,Genes, Bacterial ,Animals ,Environmental Chemistry ,Drug Resistance, Microbial ,Wastewater ,Archaea ,Pollution ,Waste Management and Disposal ,Anti-Bacterial Agents - Abstract
Advanced wastewater treatment plants are widely used in most large-scale pig farms in southern China. However, the fate of antibiotic resistance genes (ARGs) and their association with bacterial and archaeal communities during advanced wastewater treatment remain unclear. In this study, the profiles of ARGs in typical advanced wastewater treatment plants were surveyed using metagenomic analysis. The results showed that 279- 326 different subtypes of ARGs were detected in raw wastewater, with a total abundance of 5.98 ± 0.48 copies per bacterial cell. During the advanced wastewater treatment, the abundance and number of ARGs were significantly reduced. Microbial communities (bacteria and archaea) contributed the most to the variation in ARG abundance and composition (PCA axis_1), accounting for 10.8 % and 15.7 %, respectively, followed by mobile genetic elements (MGEs) and physicochemical factors. Special attention should be given to potential pathogenic bacteria such as Escherichia, Streptococcus, Enterococcus and Staphylococcus and archaea such as Methanocorpusculum, Candidatus Methanoplasma and Candidatus Methanomethylophilus, which were important potential ARG hosts. Bacterial communities may indirectly affect ARG variation by affecting archaeal communities. These findings indicated that ARG levels in pig farm wastewater can be effectively reduced during advanced treatment and highlighted the important role played by archaea, which should not be ignored.
- Published
- 2022
33. Numerical Modeling of the Injection of Nanoparticles in Saturated Cementitious Material by Electromigration
- Author
-
Yunping Xi, Mija H. Hubler, Linfei Li, and Mohamed Abdelrahman
- Subjects
Materials science ,Mechanics of Materials ,Mechanical Engineering ,Nanoparticle ,Numerical modeling ,Cementitious ,Co2 storage ,Composite material ,Electromigration ,Finite element method - Abstract
This paper presents numerical modeling of nanoparticles injected into cementitious material using the electromigration method. In order to remediate leaking wells in CO2 storage formations,...
- Published
- 2021
34. Experimental study on mechanical properties and durability of grafted nano-SiO2 modified rice straw fiber reinforced concrete
- Author
-
Jinliang Liu, Xuefeng Xie, and Linfei Li
- Subjects
General Materials Science ,Building and Construction ,Civil and Structural Engineering - Published
- 2022
35. Non-agricultural labor transfer, factor allocation and farmland yield: Evidence from the part-time peasants in Loess Plateau region of Northwest China
- Author
-
Linfei Li, Sufyan Ullah Khan, Chenhao Guo, Yanfen Huang, and Xianli Xia
- Subjects
Geography, Planning and Development ,Forestry ,Management, Monitoring, Policy and Law ,Nature and Landscape Conservation - Published
- 2022
36. Angstrom-Scale Spectroscopic Visualization of Interfacial Interactions in an Organic/Borophene Vertical Heterostructure
- Author
-
Nan Jiang, Xiaolong Liu, Linfei Li, Xu Zhang, Chasen Shaw, Mark C. Hersam, Sayantan Mahapatra, and Jeremy F. Schultz
- Subjects
Chemistry ,chemistry.chemical_element ,Heterojunction ,General Chemistry ,Biochemistry ,Atomic units ,Catalysis ,Characterization (materials science) ,symbols.namesake ,Colloid and Surface Chemistry ,Chemical physics ,Lattice (order) ,Monolayer ,Borophene ,symbols ,Raman spectroscopy ,Boron - Abstract
Two-dimensional boron monolayers (i.e., borophene) hold promise for a variety of energy, catalytic, and nanoelectronic device technologies due to the unique nature of boron-boron bonds. To realize its full potential, borophene needs to be seamlessly interfaced with other materials, thus motivating the atomic-scale characterization of borophene-based heterostructures. Here, we report the vertical integration of borophene with tetraphenyldibenzoperiflanthene (DBP) and measure the angstrom-scale interfacial interactions with ultrahigh-vacuum tip-enhanced Raman spectroscopy (UHV-TERS). In addition to identifying the vibrational signatures of adsorbed DBP, TERS reveals subtle ripples and compressive strains of the borophene lattice underneath the molecular layer. The induced interfacial strain is demonstrated to extend in borophene by ∼1 nm beyond the molecular region by virtue of 5 A chemical spatial resolution. Molecular manipulation experiments prove the molecular origins of interfacial strain in addition to allowing atomic control of local strain with magnitudes as small as ∼0.6%. In addition to being the first realization of an organic/borophene vertical heterostructure, this study demonstrates that UHV-TERS is a powerful analytical tool to spectroscopically investigate buried and highly localized interfacial characteristics at the atomic scale, which can be applied to additional classes of heterostructured materials.
- Published
- 2021
37. Defining Multiple Configurations of Rubrene on a Ag(100) Surface with 5 Å Spatial Resolution via Ultrahigh Vacuum Tip-Enhanced Raman Spectroscopy
- Author
-
Nan Jiang, Linfei Li, Sayantan Mahapatra, Chasen Shaw, Jeremy F. Schultz, and Xu Zhang
- Subjects
Surface (mathematics) ,Flexibility (anatomy) ,Materials science ,business.industry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Tip-enhanced Raman spectroscopy ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,General Energy ,medicine.anatomical_structure ,chemistry ,medicine ,Optoelectronics ,Physical and Theoretical Chemistry ,0210 nano-technology ,Rubrene ,business ,Image resolution - Abstract
Flexible polycyclic aromatic hydrocarbons (PAHs) have experienced a surge of research with the discovery of nanographenes that can be fabricated on surfaces. The flexibility in σ bonds within aroma...
- Published
- 2019
38. Determination of the active ingredients and biopotency in Polygala tenuifolia Willd. and the ecological factors that influence them
- Author
-
Xiaofang Ma, Jiayue Liu, Hong Sui, Anli Liu, Yunsheng Zhao, Zhe Cao, Nana Cen, Linfei Li, Siqi Li, and Fuying Mao
- Subjects
0106 biological sciences ,Active ingredient ,010405 organic chemistry ,Ecology ,Tenuifolin ,Biology ,biology.organism_classification ,01 natural sciences ,0104 chemical sciences ,Soil pH ,Correlation analysis ,Sunshine duration ,Polygala tenuifolia ,Medicinal plants ,Path analysis (statistics) ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
The quality of medicinal plants is closely related to the ecological factors in growing locations, and the curative ingredients and biopotency reflect their quality. This study determined the active ingredient concentrations (tenuifolin, polygalaxanthone III, 3,6′-disinapoyl sucrose, sibiricose A5, sibiricose A6 and sibiricaxanthone B) and biopotency (intelligence, tranquilisation and expectorant) of Polygala tenuifolia Willd. from the main cultivation regions of China. Moreover, this study discussed how 36 ecological factors (e.g. climate and soil condition) influenced these ingredients and their biopotency. The relationship between ecological factors and quality factors was analyzed step by step using correlation analysis, principal component analysis and path analysis. Nine ecological factors: annual mean temperature, annual sunshine duration, soil pH, Cl, Sr, Ca, S, B and exchangeable K concentration were considered as key factors that influenced the quality of cultivated P. tenuifolia. This study provided a novel approach for the quality evaluation of P. tenuifolia and a rational pattern for exploring the complex relationship between ecological factors and P. tenuifolia quality.
- Published
- 2019
39. The effect of introducing nanoparticles on the fracture toughness of well cement paste
- Author
-
Jiří Němeček, Yunping Xi, Mija H. Hubler, Linfei Li, and Shahlaa Al Wakeel
- Subjects
Toughness ,Materials science ,Fracture mechanics ,02 engineering and technology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,Microstructure ,01 natural sciences ,Pollution ,Industrial and Manufacturing Engineering ,Cracking ,General Energy ,Brittleness ,Fracture toughness ,020401 chemical engineering ,Cementitious ,0204 chemical engineering ,Composite material ,0105 earth and related environmental sciences ,Stress concentration - Abstract
The objective of the work is to understand the change in toughness caused by the introduction of repair materials into the hardened cement paste sheath surrounding a well bore. If the impact on toughness of repair material introduced into the hardened cement sheath is not considered, there exists the possibility that a leaking well may hold pressure after repair, but over the long-term crack development is encouraged. To address this, this paper presents a theoretical study of the effect of introducing nanoparticles on the density and fracture toughness of aged class G oil cement paste. The introduction of repair material in cement paste is studied in the framework of fracture mechanics which is employed to determine the effect of the cement paste microstructure near an existing crack tip. The impact of surrounding cracks, pores, and stiff nanoparticles on the fracture toughness of the material is formulated analytically using an extension to the classical J -integral. There is a linear relationship between the J -integral value and toughness if we assume a crack will propagate linearly from the defect it was initiated from. Such a formulation allows us to perform a forward analysis in the design, avoiding complex numerical models during the nanoparticle selection process in the repair. We find that the introduction of nanoparticles into aged cementitious materials increases its density which, in turn, leads to an increase in fracture toughness. The crack-tip stress concentrations near the stiff nanoparticles encourage further brittle cracking of the material, decreasing toughness. Thus, the resulting fracture toughness of the matrix is a trade-off between increasing density and stress concentration. The mechanical behavior of the cement paste containing nanoparticles was also characterized experimentally by standard three-point bending tests. Nanoparticles are injected in hardened cement paste cylinders by an electrokinetic method and samples are cut to conduct standardized toughness tests. Both the experimental and analytical results agree that an optimum particle content can be found which extends the lifetime of the cement paste without encouraging further crack development in the material.
- Published
- 2019
40. On-Surface Synthesis and Molecular Engineering of Carbon-Based Nanoarchitectures
- Author
-
Zhongyi Lu, Linfei Li, Sayantan Mahapatra, Nan Jiang, and Dairong Liu
- Subjects
Materials science ,General Engineering ,General Physics and Astronomy ,Light irradiation ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Molecular engineering ,Nanoelectronics ,chemistry ,Covalent bond ,Nano ,Molecule ,General Materials Science ,0210 nano-technology ,Carbon ,Bond cleavage - Abstract
On-surface synthesis via covalent coupling of adsorbed precursor molecules on metal surfaces has emerged as a promising strategy for the design and fabrication of novel organic nanoarchitectures with unique properties and potential applications in nanoelectronics, optoelectronics, spintronics, catalysis, etc. Surface-chemistry-driven molecular engineering (i.e., bond cleavage, linkage, and rearrangement) by means of thermal activation, light irradiation, and tip manipulation plays critical roles in various on-surface synthetic processes, as exemplified by the work from the Ernst group in a prior issue of ACS Nano. In this Perspective, we highlight recent advances in and discuss the outlook for on-surface syntheses and molecular engineering of carbon-based nanoarchitectures.
- Published
- 2021
41. Size effect in two-dimensional oxide-on-metal catalysts of CO oxidation and its connection to oxygen bonding: An experimental and theoretical approach
- Author
-
Hans-Joachim Freund, Claudine Noguera, Shamil K. Shaikhutdinov, Ke Zhang, Jacek Goniakowski, Linfei Li, Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI), Max Planck Society, Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Oxydes en basses dimensions (INSP-E9), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
iron oxide ,monolayer catalysts ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Redox ,Oxygen ,Catalysis ,Metal ,chemistry.chemical_compound ,Transition metal ,Desorption ,Monolayer ,Physical and Theoretical Chemistry ,Chemistry ,021001 nanoscience & nanotechnology ,CO oxidation ,0104 chemical sciences ,metal/oxide interface ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
Transition metal oxide layers on metal surfaces often show superior catalytic performance as compared to conventional, i.e., metal-on-oxide, systems. In this work, we studied the CO oxidation reaction over FeO supported by Pt(1 1 1) and observed strong size effects on the reactivity. The monolayer islands below 5 nm in size showed a light-off temperature for CO2 production 200 K lower than for the 30 nm islands. In an attempt to rationalize the size effect, we have performed oxygen desorption experiments and have combined them with an extended DFT analysis to provide insight into the bonding of various oxygen species in such systems. The theoretical results on isolated FeO2 islands indicate a substantially lower stability of the boundary oxygen atoms as compared with the same islands embedded into an FeO layer in qualitative agreement with experiment showing that the smaller the island, the lower the desorption temperature. To the best of our knowledge, the results demonstrate the first example of a size effect in oxidation catalysis on two-dimensional systems.
- Published
- 2021
42. Research on the Spatial-Temporal Differentiation and Path Analysis of China’s Provincial Regions’ High-Quality Economic Development
- Author
-
Boyang Zhou, Nan Wang, Zhen Zhang, Wenxin Liu, Weinan Lu, Ruifan Xu, and Linfei Li
- Subjects
Renewable Energy, Sustainability and the Environment ,Geography, Planning and Development ,high-quality economic development ,spatial-temporal analysis ,KDE model ,LSE model ,path analysis ,Management, Monitoring, Policy and Law - Abstract
High-quality economic development is an important approach for achieving sustainable economic development, and it is an essential condition for coordinated development between economic systems and ecosystems. This paper starts from five key points, namely, “innovation, coordination, opening-up, sharing and greenness”, to construct an evaluation system for the index of high-quality economic development, using the AHP and EVM methods to measure the level of high-quality economic development of 30 regions in China from 2004 to 2019. It uses the kernel density estimation model (hereinafter referred to briefly as KDE) and clustering method to analyze time evolution trends and spatial variation characteristics. Moreover, the LSE model is adopted to explore and analyze the factors influencing high-quality economic development in different regions. Additionally, the driving forces of China’s high-quality economic development are analyzed by means of path analysis combined with the average value of each index. The results show the following: (1) The high-quality economic development of 30 regions in China (excluding Hong Kong, Macao, Taiwan and Tibet) is spatially clustered, with obviously different development levels, characterized by the eastern region being better developed than the central and western regions. (2) With the passage of time, the polarization of China’s 30 regions has been alleviated, but they are still facing challenging development situations; (3) The factors affecting the high-quality economic development of these 30 regions in China can be divided into four types: three-factors, four-factors-I, four-factors-II and five-factors. Contributing regional factors show different distribution characteristics. The above conclusion provides a reference and scientific basis for the government to formulate policies of high-quality economic development and to solve problems facing coordinated sustainable development among regional societies, their economies and the environment.
- Published
- 2022
43. Modeling carbonation and chloride ingress in well cements
- Author
-
Jinliang Liu, Yuxiang Jing, and Linfei Li
- Subjects
Fuel Technology ,Geotechnical Engineering and Engineering Geology - Published
- 2022
44. Chemically imaging nanostructures formed by the covalent assembly of molecular building blocks on a surface with ultrahigh vacuum tip-enhanced Raman spectroscopy
- Author
-
Nan Jiang, Sayantan Mahapatra, Jeremy Schultz, and Linfei Li
- Subjects
General Materials Science ,Condensed Matter Physics - Abstract
Surface-bound reactions have become a viable method to develop nanoarchitectures through bottom-up assembly with near atomic precision. However, the bottom-up fabrication of nanostructures on surfaces requires careful consideration of the intrinsic properties of the precursors and substrate as well as the complex interplay of any interactions that arise in the heterogeneous two-dimensional (2D) system. Therefore, it becomes necessary to consider these systems with characterization methods sensitive to such properties with suitable spatial resolution. Here, low temperature ultrahigh vacuum scanning tunneling microscopy (STM) and tip-enhanced Raman spectroscopy (TERS) were used to investigate the formation of 2D covalent networks via coupling reactions of tetra(4-bromophenyl)porphyrin (Br4TPP) molecules on a Ag(100) substrate. Through the combination of STM topographic imaging and TERS vibrational fingerprints, the conformation of molecular precursors on the substrate was understood. Following the thermally activated coupling reaction, STM and TERS imaging confirm the covalent nature of the 2D networks and suggest that the apparent disorder arises from molecular flexibility.
- Published
- 2022
45. Proximity and single-molecule energetics
- Author
-
Nan Jiang and Linfei Li
- Subjects
Multidisciplinary ,Materials science ,Energetics ,Nanotechnology ,Thermodynamics ,Molecule ,Computational biology - Abstract
Scanning probes measure how nearby oxygen molecules affect triplet lifetimes of pentacene
- Published
- 2021
46. Application of Nanoparticle Injection Technology for Remediating Leaks by Using a Horizontally Full-scale Wellbore System
- Author
-
Linfei Li
- Published
- 2020
47. Neuronal Nitric Oxide Synthase Knockdown Within Basolateral Amygdala Induces Autistic-Related Phenotypes and Decreases Excitatory Synaptic Transmission in Mice
- Author
-
Daoqi Mei, Huichun Zhang, Linfei Li, Leiming Liu, Quanfeng Fang, Xiaona Wang, Jing Liu, Lingshan Gou, Yaodong Zhang, Zhigang Yang, Chao Gao, Jinxiu Xu, and Yinsen Song
- Subjects
0301 basic medicine ,neuronal nitric oxide synthase ,Interneuron ,autism spectrum disorder ,interneuron ,Neurotransmission ,Open field ,lcsh:RC321-571 ,Marble burying ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,medicine ,synaptic transmission ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Original Research ,Gene knockdown ,Chemistry ,General Neuroscience ,030104 developmental biology ,medicine.anatomical_structure ,nervous system ,Neuroscience ,Postsynaptic density ,030217 neurology & neurosurgery ,basolateral amygdala ,Basolateral amygdala - Abstract
Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by deficits in communication, impaired social interaction, and repetitive or restricted interests and behaviors. We have recently shown that neuronal nitric oxide synthase (nNOS) expression was reduced in the basolateral amygdala of mice after postnatal valproic acid exposure. However, the specific role of nNOS downregulation in mice remains to be elucidated. Herein, we investigated the behavioral alternations of naive mice with a recombinant adeno-associated virus (rAAV)-mediated knockdown of nNOS in a comprehensive test battery, including the social interaction, marble burying, self-grooming, and open field tests. Further, the electrophysiological and surface expression changes induced by nNOS deficiency of the basolateral amygdala in these animals were examined. Our results show that nNOS knockdown displayed typical symptoms of ASD-like behaviors, such as reduced social interaction and communication, elevated stereotypes, and anxiety in mice. Surprisingly, we found that nNOS knockdown exhibited greatly reduced excitatory synaptic transmission concomitant with the lower surface expression of GluN2B-containing N-methyl-D-aspartate receptors and postsynaptic density protein 95 in mice. These findings support a notion that dysregulation of nNOS might contribute to ASD-associated phenotypes, with disease pathogenesis most likely resulting from deficits in excitatory synaptic transmission.
- Published
- 2020
48. Tip-enhanced Raman spectroscopy: Chemical analysis with nanoscale to angstrom scale resolution
- Author
-
Linfei Li, Nan Jiang, Sayantan Mahapatra, and Jeremy F. Schultz
- Subjects
Materials science ,010304 chemical physics ,Scale (chemistry) ,Resolution (electron density) ,General Physics and Astronomy ,Nanotechnology ,010402 general chemistry ,Tip-enhanced Raman spectroscopy ,01 natural sciences ,0104 chemical sciences ,symbols.namesake ,0103 physical sciences ,symbols ,Molecule ,Angstrom ,Physical and Theoretical Chemistry ,Raman spectroscopy ,Nanoscopic scale - Abstract
Tip-enhanced Raman spectroscopy (TERS), a cutting-edge near-field spectroscopic tool, provides invaluable chemical insight with impressive spatial resolution in chemistry-related fields such as molecular and catalytic systems, surface science, two-dimensional materials, and biochemistry. High-resolution TERS, in particular, which has advanced exceptionally in the last five years, provides a unique opportunity to scrutinize single molecules individually. Here, this perspective places emphasis on the basic concepts and recent experimental findings of this state-of-the-art research and concludes with a glimpse of future prospects.
- Published
- 2020
49. The Expanding Frontiers of Tip-Enhanced Raman Spectroscopy
- Author
-
Sayantan Mahapatra, Jeremy F. Schultz, Linfei Li, and Nan Jiang
- Subjects
Resolution (electron density) ,Nanotechnology ,02 engineering and technology ,Surface-enhanced Raman spectroscopy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,symbols.namesake ,Scanning probe microscopy ,law ,symbols ,Near-field scanning optical microscope ,Scanning tunneling microscope ,0210 nano-technology ,Spectroscopy ,Raman spectroscopy ,Instrumentation ,Plasmon - Abstract
Fundamental understanding of chemistry and physical properties at the nanoscale enables the rational design of interface-based systems. Surface interactions underlie numerous technologies ranging from catalysis to organic thin films to biological systems. Since surface environments are especially prone to heterogeneity, it becomes crucial to characterize these systems with spatial resolution sufficient to localize individual active sites or defects. Spectroscopy presents as a powerful means to understand these interactions, but typical light-based techniques lack sufficient spatial resolution. This review describes the growing number of applications for the nanoscale spectroscopic technique, tip-enhanced Raman spectroscopy (TERS), with a focus on developments in areas that involve measurements in new environmental conditions, such as liquid, electrochemical, and ultrahigh vacuum. The expansion into unique environments enables the ability to spectroscopically define chemistry at the spatial limit. Through the confinement and enhancement of light at the apex of a plasmonic scanning probe microscopy tip, TERS is able to yield vibrational fingerprint information of molecules and materials with nanoscale resolution, providing insight into highly localized chemical effects.
- Published
- 2020
50. Reversible Single Spin Control of Individual Magnetic Molecule by Hydrogen Atom Adsorption
- Author
-
Haitao Zhou, Hong-Jun Gao, Yuhang Jiang, Antonio H. Castro Neto, Yeliang Wang, Wende Xiao, Linfei Li, Min Ouyang, Liwei Liu, Werner A. Hofer, Kai Yang, Shixuan Du, and Boqun Song
- Subjects
Spin states ,FOS: Physical sciences ,02 engineering and technology ,Electron ,01 natural sciences ,7. Clean energy ,Article ,Ion ,chemistry.chemical_compound ,Atomic orbital ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,Molecule ,Physics::Atomic Physics ,Physics - Atomic and Molecular Clusters ,010306 general physics ,Physics ,Multidisciplinary ,Condensed Matter - Mesoscale and Nanoscale Physics ,Hydrogen atom ,021001 nanoscience & nanotechnology ,chemistry ,Chemical physics ,Phthalocyanine ,Density functional theory ,Condensed Matter::Strongly Correlated Electrons ,Atomic and Molecular Clusters (physics.atm-clus) ,0210 nano-technology - Abstract
The reversible control of a single spin of an atom or a molecule is of great interest in Kondo physics and a potential application in spin based electronics.Here we demonstrate that the Kondo resonance of manganese phthalocyanine molecules on an Au(111) substrate have been reversibly switched off and on via a robust route through attachment and detachment of single hydrogen atom to the magnetic core of the molecule. As further revealed by density functional theory calculations, even though the total number of electrons of the Mn ion remains almost the same in the process, gaining one single hydrogen atom leads to redistribution of charges within 3d orbitals with a reduction of the molecular spin state from S = 3/2 to S = 1 that directly contributes to the Kondo resonance disappearance. This process is reversed by a local voltage pulse or thermal annealing to desorb the hydrogen atom.
- Published
- 2020
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