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1.
Nanotechnology ; 34(26)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-36975182

RESUMO

The effects of yttrium dopants on the phase change behavior and microstructure of Sn15Sb85films have been systematically investigated. The yttrium-doped Sn15Sb85film has the higher phase transition temperature, ten year data retention ability and crystallization activation energy, which represent a great improvement in thermal stability and data retention. X-ray diffraction, transmission electron microscopy and x-ray photoelectron spectroscopy reveal that the amorphous Sn and Y components restrict the grain growth and decrease the grain size. Raman mode typically associated with Sb is altered when the substance crystallized. Atomic force microscopy results show that the surface morphology of the doped films becomes smoother. T-shaped phase change storage cells based on yttrium-doped Sn15Sb85films exhibit the lower power consumption. The results demonstrate that the crystallization characteristics of Sn15Sb85film can be tuned and optimized through the yttrium dopant for the excellent performances of phase change memory.

2.
J Environ Manage ; 272: 111119, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32854898

RESUMO

China is facing great water and energy pressure due to industrialization, urbanization, population growth and environmental change. China's explosive economic development has come at a steep cost in terms of natural resource exploitation and environmental problems. These unintended negative consequences are partly the result of a narrow single-sector management approach to natural resources, which often caused conflicts and low efficiency of related policies. Although the nexus approach is beneficial for optimization of natural resource utilization and development, the question of whether it can be applied in policy and practice is determined by various factors. The science-policy interface that stresses the political and social contexts provides a useful perspective for understanding the process of the nexus approach, from the scientific domain to policy. Combining criteria of good governance and an effective science-policy interface, suggestions for promoting good energy-water nexus governance are put forward, including popularization of scientific knowledge about the nexus in the political and social fields, collaborative governance of the nexus, and accelerating good governance of the whole of society.


Assuntos
Urbanização , Água , China , Conservação dos Recursos Naturais , Desenvolvimento Econômico
3.
Heliyon ; 9(10): e20782, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37842605

RESUMO

As a nature-based solution for climate change mitigation, blue carbon has been highlighted for realizing carbon neutrality in China. China's central and local governments have issued many policies to promote blue carbon protection and development. However, scaling up blue carbon restoration and protection is required for its substantial contribution to carbon neutrality. This study evaluates the characteristics of China's blue carbon policies using qualitative document analysis based on policy instrument theory. The distribution of different policy instruments among blue carbon policies and resources is analyzed. Suggestions for improving blue carbon policy supply are put forward combined with comparative experience from international organizations and other jurisdictions. The following policies should be strengthened to secure efficient blue carbon protection, restoration, and creation: blue carbon protection legislation, marine ecological compensation system, stable investment in blue carbon projects, integrated blue carbon verification system, and inclusion of blue carbon in regulated carbon markets.

4.
Soft Matter ; 3(8): 986-992, 2007 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32900048

RESUMO

This article describes emulsification in a microfluidic double droplet generator (DDR) comprising two consecutive flow-focusing devices with locally modified surface chemistry. We generated W/O/W, O/O/W and O/W/O double emulsions with precisely controlled sizes and morphology of droplets. Secondly, by combining two mechanisms of droplet formation (the flow-focusing mechanism and the break up of liquid threads at T-junction) we produced multiple populations of droplets with varying size and/or composition. These droplets were used as the structural units for the formation of complex dynamic lattices.

5.
Langmuir ; 21(25): 11614-22, 2005 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-16316091

RESUMO

This article provides an overview of our work in the area of the synthesis of polymer particles in continuous microfluidic reactors. The method includes (a) the generation of highly monodisperse monomer droplets in a microfluidic flow-focusing device and (b) in-situ solidification of these droplets by means of photopolymerization. We discuss the effect of monomer properties on the emulsification process, the effect of the polymerization rate on the production of high-quality particles, the role of the material of the microfluidic device in droplet formation, and the synthesis of particles with different shapes and compositions. We also demonstrate the production of highly ordered arrays of polymer particles achieved by photopolymerization of the dynamic lattices of monomer droplets in microfluidic channels. The article is concluded with a summary of future research directions in the production of polymer colloids in microfluidic reactors.

6.
J Rheumatol ; 42(10): 1878-84, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26276969

RESUMO

OBJECTIVE: The function of the infrapatellar fat pad (IPFP) in knee osteoarthritis (OA) remains uncertain. This study aimed to examine cross-sectional associations between IPFP volume and knee structures in patients with knee OA. METHODS: The study included 174 patients with clinical knee OA (mean age, 55.5 yrs). Fat-suppressed 3-D T1-weighted spoiled gradient recall magnetic resonance imaging (MRI) was used to measure the IPFP and cartilage volume. T2-weighted fast spin echo MRI was used to assess cartilage defects and bone marrow lesions (BML). Radiographic knee osteophytes and joint space narrowing (JSN) were assessed using the Osteoarthritis Research Society International atlas. RESULTS: After adjustment for potential confounders, greater IPFP volume was associated with greater tibial and patellar cartilage volume (all p < 0.05), and fewer cartilage defects at all sites (OR 0.88-0.91, all p < 0.05). IPFP volume was associated with presence of BML at lateral tibial and medial femoral sites (OR 0.88-0.91, all p < 0.05) and osteophytes at lateral tibiofemoral compartment (OR 0.88, p < 0.05). IPFP volume was not significantly associated with JSN. CONCLUSION: Greater IPFP volume was associated with greater knee cartilage volume and fewer structural abnormalities, suggesting a protective role of IPFP size in knee OA.


Assuntos
Tecido Adiposo/patologia , Cartilagem Articular/patologia , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/patologia , Patela/patologia , Adulto , Fatores Etários , Idoso , Análise de Variância , Antropometria , Austrália , Estudos Transversais , Progressão da Doença , Feminino , Humanos , Modelos Logísticos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Medição de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Tomografia Computadorizada por Raios X/métodos
8.
J Am Chem Soc ; 128(29): 9408-12, 2006 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-16848476

RESUMO

This paper reports a microfluidic method for fast continuous synthesis of Janus particles and three-phase particles with narrow size distribution. Synthesis of particles included emulsification of monomer liquids and in-situ photoinitiated polymerization of multiphase droplets. We show the strategy for precise control over the structure of Janus particles and their structure-dependent assembly in clusters. We demonstrate an asymmetric chemical modification of the surface of JPs by conjugating them with protein molecules. The Janus and ternary particles were synthesized from largely immiscible liquids and had a sharp interface between the constituent phases.

9.
J Am Chem Soc ; 127(22): 8058-63, 2005 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-15926830

RESUMO

We report a novel approach to continuous and scalable production of core-shell droplets and polymer capsules in microfluidic devices. The described method is also useful in the synthesis of polymer particles with nonspherical shapes. We used capillary instability-driven break-up of a liquid jet formed by two immiscible fluids. Precise control of emulsification of each liquid allowed for the production of highly monodisperse core-shell droplets with a predetermined diameter of cores and thickness of shells. We also achieved control over the number of cores per droplet and the location of cores in the droplet. We carried out fast throughput photopolymerization of the monomeric shells and obtained polymer particles with various shapes and morphologies, including spheres, truncated spheres and, hemispheres, and single and multicore capsules.

10.
Langmuir ; 21(11): 4773-5, 2005 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-15896006

RESUMO

We used coupling of flow and geometric confinement to assemble emulsion droplets in two-dimensional gliding lattices with a high degree of order and symmetry. Highly monodisperse discoid droplets with circular shapes were generated in a microfluidic flow-focusing device. Originally, close-packed lattices formed from these circular discoid droplets. Progressive confinement led to the gradual deformation of the circular disks: first, they elongated in the direction parallel to the direction of flow and then transformed into hexagons. Assembly driven by the combination of flow and confinement also allowed for the formation of lattices from droplets with a bimodal size distribution. We used photopolymerization of the monomer droplets to trap the lattice structure in the solid state and produce highly periodic arrays of solid polymer disks.

11.
J Am Chem Soc ; 124(7): 1142-3, 2002 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-11841262

RESUMO

A new strategy for producing ordered polymeric films is proposed, which employs replication of interfacial instabilities. In the first step, a thin film of a monomeric fluid is brought in contact with a nonpolymerizable template layer of poly(dimethylsiloxane), and surface tension-driven convection is induced in the template liquid. In the second stage, Bénard cells replicated in the monomeric layer by a viscous drug are trapped in the solid state by UV-induced polymerization. Following this step, the template fluid is removed. The topographic patterns "frozen" in the polymeric film have lateral and vertical periodicity determined by the properties of the template fluid.

12.
J Am Chem Soc ; 126(25): 7908-14, 2004 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-15212539

RESUMO

We report a strategy for the production of materials with structural hierarchy. The approach employs polymer microgels as templates for the synthesis of semiconductor, metal, or magnetic nanoparticles (NPs). We show that NPs with predetermined dimensions and size-dependent properties can be synthesized by using a very delicate balance between the reaction conditions, the composition and the structure of microgel templates, and the concentration of NPs in the microgel. Postheat treatment of microgels doped with semiconductor nanoparticles reduces NP polydispersity and allows control of their photoluminescence. Microgel templates are particularly beneficial in the synthesis of polymer microspheres heavily loaded with monodisperse superparamagnetic Fe(3)O(4) NPs. Hybrid submicrometer-size microgels have promising potential applications in photonics, catalysis, and separation technologies.

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