Wet stability, penetration resistance (PR), and tensile strength (TS) of paddy soils under a fertilization experiment for 22 years were determined to elucidate the function of soil organic matter in paddy soil sta...Wet stability, penetration resistance (PR), and tensile strength (TS) of paddy soils under a fertilization experiment for 22 years were determined to elucidate the function of soil organic matter in paddy soil stabilization. The treatments included no fertilization (CK), normal chemical fertilization (NPK), double the NPK application rates (2NPK), and NPK mixed with organic manure (NPK+OM). Compared with CK, Fertilization increased soil organic carbon (SOC) and soil porosity. The results of soil aggregate fragmentation degree (SAFD) showed that fast wetting by water was the key fragmentation mechanism. Among the treatments, the NPK+OM treatment had the largest size of water-stable aggregates and greatest normal mean weight diameter (NMWD) (P ≤ 0.05), but the lowest PR and TS in both cultivated horizon (Ap) and plow pan. The CK and 2NPK treatments were measured with PR 〉 2.0 MPa and friability index 〈 0.20, respectively, in the Ap horizon, suggesting that the soils was mechanically unfavourable to root growth and tillage. In the plow pan, the fertilization treatments had greater TS and PR than in CK. TS and PR of the tested soil aggregates were negatively correlated to SOC content and soil porosity. This study suggested that chemical fertilization could cause deterioration of mechanical properties while application of organic manure could improve soil stability and mechanical properties.展开更多
The materials used in fuel cells are currently the subject of much research, particularly those of the cathode which is a key element for the different functions that it provides. In our work the authors became intere...The materials used in fuel cells are currently the subject of much research, particularly those of the cathode which is a key element for the different functions that it provides. In our work the authors became interested in the different materials used for the cathode, which are usually ceramic, and some of their physical properties between different electrical conductivity (electronic, ionic), the coefficient of thermal expansion and chemical compatibility between different materials used in the stack. Not to mention, however, the various parameters that influence these properties, such as structure, the sintering temperature, dope, and the operating temperature of the battery. The main objective of research in this area is to improve battery performance by researching new materials and new manufacturing technologies that will increase the electrical conductivity while trying to lower the temperature operating the latter as much as possible while keeping it above 650℃, In doing so, the longevity of the battery will be increased which will have a direct impact on manufacturing costs of the battery, and thus greater use thereof.展开更多
Abstract The rapid development and production of nanomaterials has created some concerns about their potential hazard on the environment, human health and safety. However, since the list of materials that may gen- era...Abstract The rapid development and production of nanomaterials has created some concerns about their potential hazard on the environment, human health and safety. However, since the list of materials that may gen- erate such concerns is very long, it is impossible to test them all. It is therefore usually recommended to use some small compositional nanomaterial libraries to perform ini- tial toxicity screening, based on which combinatorial libraries are then introduced for more in-depth studies. All nanomaterials in the compositional and combinatorial libraries must be rigorously characterized before any bio- logical studies. In this review, several major categories of physicochemical properties that must be characterized are discussed, along with different analytical techniques that are commonly used. Some case studies from the University of California Center for Environmental Implications of Nanotechnology are also chosen to demonstrate the effec- tive use of compositional and combinatorial nanomaterials libraries to identify the role of some key physicochemical properties and to establish true quantitative structure-ac- tivity relationships. Examples on how to use the knowledge generated from those studies to design safer nanomaterials for improved biological applications are also presented.展开更多
Noble metal nanomaterials have been extensively explored in cancer diagnostic and therapeutic applica- tions owing to their unique physical and chemical properties, such as facile synthesis, straightforward surface fu...Noble metal nanomaterials have been extensively explored in cancer diagnostic and therapeutic applica- tions owing to their unique physical and chemical properties, such as facile synthesis, straightforward surface functionalization, strong photothermal effect, and excellent biocompatibility. Herein, we summa- rize the recent development of two-dimensional (2D) Pd-based nanomaterials and their applications in cancer diagnosis and therapy. Different synthetic strategies for Pd nanosheets and the related nanostruc- tures, including Pd@Au, Pd@Ag nanoplates and mesocrystalline Pd nanocomlla, are first discussed. Together with their unique properties, the potential bioapplications of these 2D Pd nanomaterials are then demonstrated. With strong absorption in near-infrared (NIR) region, these nanomaterials have great potentials in cancer photothermal therapy (PTr). They also readily act as contrast agents in photoacoustic (PA) imaging or X-ray computed tomography (CT) to achieve image-guided cancer therapy. Moreover, significant efforts have been devoted to studying the combination of PTr and other treatment modalities (e.g., chemotherapy or photodynamic therapy) based on Pd nanomaterials. The remarkable synergistic or collaborative effects to achieve better therapeutic efficacy are discussed as well. Additionally, the biosaf- ety of 2D Pd-based nanomaterials in vitro and in vivo was evaluated. Finally, challenges for the applica- tions of Pd-based nanomaterials in cancer diagnosis and therapy, and future research prospects are highlighted.展开更多
A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical me...A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical mechanical stress (σ^M) originates from lat- tice strain (e), following Hooke's law: σ^M=Cε, where C is elastic constant matrix. Recently, a new concept of quantum electronic stress (o-QE) is introduced to elucidate the extrinsic electronic effects on the stress state of solids and thin films, which follows a quantum analog of classical Hooke's law: ~QE=E(An), where E is the deformation potential of electronic states and An is the variation of electron density. Here, we present mathematical derivation of both the classical and quantum Hooke's law from density functional theory. We further discuss the physical origin of quantum electronic stress, arising purely from electronic excitation and perturbation in the absence of lattice strain (g=0), and its relation to the degeneracy pressure of electrons in solid and their interaction with the lattice.展开更多
As professional antigen presenting cells, dendritic cells(DCs) greatly determine the quality of the innate and adaptive immunities. Therefore, DC-based immunotherapy has been one of the hotspots in cancer immunotherap...As professional antigen presenting cells, dendritic cells(DCs) greatly determine the quality of the innate and adaptive immunities. Therefore, DC-based immunotherapy has been one of the hotspots in cancer immunotherapy in recent years. Although this unique therapeutic strategy has been approved by U.S. Food and Drug Administration for prostate cancer treatment, the efficacy of DC-based immunotherapy remains to be further improved. Moreover, it is still not completely clear about the immunological basis of DCs, which is another hurdle for the progress of DC-based immunotherapy. Due to their unique physicochemical properties, nanomaterials have shown potentials in addressing these above mentioned problems and have provided important guidelines for optimizing DC-based immunotherapy. However, it is still at the starting stage for this emerging field and there are many critical questions in the rational design of this therapeutic strategy to be answered. Therefore, it is greatly necessary to review and analyze recent progresses in this field. In this review, we mainly focus on the development of various types nanoparticles for DC-based immunotherapy. The existed challenges in this field are also discussed.展开更多
Graphitized nanocarbon materials can be an ideal catalyst support for heterogeneous catalytic systems. Their unique physical and chemical properties, such as large surface area, high adsorption capacity, excellent the...Graphitized nanocarbon materials can be an ideal catalyst support for heterogeneous catalytic systems. Their unique physical and chemical properties, such as large surface area, high adsorption capacity, excellent thermal and mechanical stability, outstanding electronic properties, and tunable porosity, allow the anchoring and dispersion of the active metals. Therefore, currently they are used as the key support material in many catalytic processes. This review summarizes recent relevant applications in supported catalysts that use graphitized nanocarbon as supports for catalytic oxidation, hydrogenation, dehydrogenation, and C-C coupling reactions in liquid-phase and gas-solid phase-reaction systems. The latest developments in specific features derived from the morphology and characteristics of graphitized na- nocarbon-supported metal catalysts are highlighted, as well as the differences in the catalytic behavior of graphitized nano- carbon-supported metal catalysts versus other related cata- lysts. The scientific challenges and opportunities in this field are also discussed.展开更多
基金Project supported by the National Natural Science Foundation of China (No.40371059).
文摘Wet stability, penetration resistance (PR), and tensile strength (TS) of paddy soils under a fertilization experiment for 22 years were determined to elucidate the function of soil organic matter in paddy soil stabilization. The treatments included no fertilization (CK), normal chemical fertilization (NPK), double the NPK application rates (2NPK), and NPK mixed with organic manure (NPK+OM). Compared with CK, Fertilization increased soil organic carbon (SOC) and soil porosity. The results of soil aggregate fragmentation degree (SAFD) showed that fast wetting by water was the key fragmentation mechanism. Among the treatments, the NPK+OM treatment had the largest size of water-stable aggregates and greatest normal mean weight diameter (NMWD) (P ≤ 0.05), but the lowest PR and TS in both cultivated horizon (Ap) and plow pan. The CK and 2NPK treatments were measured with PR 〉 2.0 MPa and friability index 〈 0.20, respectively, in the Ap horizon, suggesting that the soils was mechanically unfavourable to root growth and tillage. In the plow pan, the fertilization treatments had greater TS and PR than in CK. TS and PR of the tested soil aggregates were negatively correlated to SOC content and soil porosity. This study suggested that chemical fertilization could cause deterioration of mechanical properties while application of organic manure could improve soil stability and mechanical properties.
文摘The materials used in fuel cells are currently the subject of much research, particularly those of the cathode which is a key element for the different functions that it provides. In our work the authors became interested in the different materials used for the cathode, which are usually ceramic, and some of their physical properties between different electrical conductivity (electronic, ionic), the coefficient of thermal expansion and chemical compatibility between different materials used in the stack. Not to mention, however, the various parameters that influence these properties, such as structure, the sintering temperature, dope, and the operating temperature of the battery. The main objective of research in this area is to improve battery performance by researching new materials and new manufacturing technologies that will increase the electrical conductivity while trying to lower the temperature operating the latter as much as possible while keeping it above 650℃, In doing so, the longevity of the battery will be increased which will have a direct impact on manufacturing costs of the battery, and thus greater use thereof.
基金supported by the National Science Foundation and the Environmental Protection Agency to UCCEIN under Cooperative Agreement No. DBI-1266377Partial support was also provided by U.S. Public Health Service Grants (R01 ES016746 and U19 ES019528)
文摘Abstract The rapid development and production of nanomaterials has created some concerns about their potential hazard on the environment, human health and safety. However, since the list of materials that may gen- erate such concerns is very long, it is impossible to test them all. It is therefore usually recommended to use some small compositional nanomaterial libraries to perform ini- tial toxicity screening, based on which combinatorial libraries are then introduced for more in-depth studies. All nanomaterials in the compositional and combinatorial libraries must be rigorously characterized before any bio- logical studies. In this review, several major categories of physicochemical properties that must be characterized are discussed, along with different analytical techniques that are commonly used. Some case studies from the University of California Center for Environmental Implications of Nanotechnology are also chosen to demonstrate the effec- tive use of compositional and combinatorial nanomaterials libraries to identify the role of some key physicochemical properties and to establish true quantitative structure-ac- tivity relationships. Examples on how to use the knowledge generated from those studies to design safer nanomaterials for improved biological applications are also presented.
基金supported by the National Natural Science Foundation of China (21101131, 21420102001)the National Basic Research Program of China (2014CB932004)Natural Science Foundation of Fujian Province (2016J01073)
文摘Noble metal nanomaterials have been extensively explored in cancer diagnostic and therapeutic applica- tions owing to their unique physical and chemical properties, such as facile synthesis, straightforward surface functionalization, strong photothermal effect, and excellent biocompatibility. Herein, we summa- rize the recent development of two-dimensional (2D) Pd-based nanomaterials and their applications in cancer diagnosis and therapy. Different synthetic strategies for Pd nanosheets and the related nanostruc- tures, including Pd@Au, Pd@Ag nanoplates and mesocrystalline Pd nanocomlla, are first discussed. Together with their unique properties, the potential bioapplications of these 2D Pd nanomaterials are then demonstrated. With strong absorption in near-infrared (NIR) region, these nanomaterials have great potentials in cancer photothermal therapy (PTr). They also readily act as contrast agents in photoacoustic (PA) imaging or X-ray computed tomography (CT) to achieve image-guided cancer therapy. Moreover, significant efforts have been devoted to studying the combination of PTr and other treatment modalities (e.g., chemotherapy or photodynamic therapy) based on Pd nanomaterials. The remarkable synergistic or collaborative effects to achieve better therapeutic efficacy are discussed as well. Additionally, the biosaf- ety of 2D Pd-based nanomaterials in vitro and in vivo was evaluated. Finally, challenges for the applica- tions of Pd-based nanomaterials in cancer diagnosis and therapy, and future research prospects are highlighted.
基金supported by the DOE-BES program(Grant No.DE-04ER46148)NSF-MRSEC(Grant No.DMR-1121252)
文摘A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical mechanical stress (σ^M) originates from lat- tice strain (e), following Hooke's law: σ^M=Cε, where C is elastic constant matrix. Recently, a new concept of quantum electronic stress (o-QE) is introduced to elucidate the extrinsic electronic effects on the stress state of solids and thin films, which follows a quantum analog of classical Hooke's law: ~QE=E(An), where E is the deformation potential of electronic states and An is the variation of electron density. Here, we present mathematical derivation of both the classical and quantum Hooke's law from density functional theory. We further discuss the physical origin of quantum electronic stress, arising purely from electronic excitation and perturbation in the absence of lattice strain (g=0), and its relation to the degeneracy pressure of electrons in solid and their interaction with the lattice.
基金supported by the National Basic Research Program of China (2012CB932601, 2011CB911000)the National Natural Science Foundation of China (51222203, 31300824, 51302180)+1 种基金the Natural Science Foundation of Jiangsu Province (BK20130005)China Postdoctoral Science Foundation (2013M530267)
文摘As professional antigen presenting cells, dendritic cells(DCs) greatly determine the quality of the innate and adaptive immunities. Therefore, DC-based immunotherapy has been one of the hotspots in cancer immunotherapy in recent years. Although this unique therapeutic strategy has been approved by U.S. Food and Drug Administration for prostate cancer treatment, the efficacy of DC-based immunotherapy remains to be further improved. Moreover, it is still not completely clear about the immunological basis of DCs, which is another hurdle for the progress of DC-based immunotherapy. Due to their unique physicochemical properties, nanomaterials have shown potentials in addressing these above mentioned problems and have provided important guidelines for optimizing DC-based immunotherapy. However, it is still at the starting stage for this emerging field and there are many critical questions in the rational design of this therapeutic strategy to be answered. Therefore, it is greatly necessary to review and analyze recent progresses in this field. In this review, we mainly focus on the development of various types nanoparticles for DC-based immunotherapy. The existed challenges in this field are also discussed.
基金supported by the Ministry of Science and Technology (2016YFA0204100)the National Natural Science Foundation of China (21573254 and 91545110)+1 种基金the Youth Innovation Promotion Association (CAS)the Sinopec China and Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09030103)
文摘Graphitized nanocarbon materials can be an ideal catalyst support for heterogeneous catalytic systems. Their unique physical and chemical properties, such as large surface area, high adsorption capacity, excellent thermal and mechanical stability, outstanding electronic properties, and tunable porosity, allow the anchoring and dispersion of the active metals. Therefore, currently they are used as the key support material in many catalytic processes. This review summarizes recent relevant applications in supported catalysts that use graphitized nanocarbon as supports for catalytic oxidation, hydrogenation, dehydrogenation, and C-C coupling reactions in liquid-phase and gas-solid phase-reaction systems. The latest developments in specific features derived from the morphology and characteristics of graphitized na- nocarbon-supported metal catalysts are highlighted, as well as the differences in the catalytic behavior of graphitized nano- carbon-supported metal catalysts versus other related cata- lysts. The scientific challenges and opportunities in this field are also discussed.