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正Ionic liquids(ILs)are organic salts with low melting points,which have many unusual properties like negligible vapor pressure,good thermal stability,non-flammability,wide liquid range and electrochemical window,and excellent solvation power for both organic and inorganic substances.The unique characteristics of ILs endow them with great potential for applications in different fields including chemical reactions,extraction and separation,material science,  相似文献   

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Gamma ray energy-absorption buildup factors were computed using the five-parameter geometric progression (G-P) fitting formula for seven thermoluminescent dosimetric (TLD) materials in the energy range 0.015–15 MeV, and for penetration depths up to 40 mfp (mean free path). The generated energy-absorption buildup factor data have been studied as a function of penetration depth and incident photon energy. Buildup factors determined in the present work should be useful in radiation dosimetry, diagnostics and therapy. The tissue equivalence of TLD materials is also discussed.  相似文献   

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Two new human hair reference materials, with different levels of mercury and methylmercury, have been developed and characterized by the International Atomic Energy Agency, for use in validation of measurements for mercury exposure. The set of materials consists of IAEA-086, with a low level of methylmercury, and IAEA-085, with an elevated methylmercury level. An international intercomparison exercise was carried out, and 68 institutes from 40 countries have contributed data. Based on the evaluation of the results from the intercomparison and analyses by expert laboratories, values of 23.2 and 0.57 mg/kg total mercury are recommended for IAEA-085 and IAEA-086, respectively. Values for methylmercury are recommended at 22.9 mg/kg, MeHg as Hg, for IAEA-085, and at 0.26 mg/kg, MeHg as Hg, for IAEA-086. Recommended and information values are also given for other selected trace elements.  相似文献   

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Measurements are described of the strength of a model adhesive joint subjected to (1) tensile rupture, with the interface containing a small unbonded region of varying size, and (2) pure shear deformation, in the form of a partly unbonded sheet. These, and previous measurements of resistance to peeling separation, are all shown to be consistent with an energy criterion for adhesive failure. The characteristic failure energy per unit area of interface has been determined for the model adhesive material as a function of the effective rate of detachment, over a wide range covering almost the entire spectrum of viscoelastic response. The values obtained are found to increase from levels only slightly higher than thermodynamic considerations would predict, i.e., 102?103 ergs/cm2, at low rates of crack propagation, up to a value of about 106 ergs/cm2 at high rates when the material responds in a glasslike manner. These results suggest that the failure energy has two components: the (reversible) work of adsorption and the (irreversible) work of deformation of the adhesive in effecting separation.  相似文献   

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Recently, there has been a renewed interest in the development of sensor materials. Four major trends can be discerned in this new research, i.e., (1) single crystal to poly crystal to amorphous material; (2) static material to dynamic material; (3) simple material to composite material; (4) atomic (molecular) synthesis of sensor material. These trends are an approach to obtaining ‘intelligent materials’.Up to now, sensor devices have been made using materials with given characteristics. In future, however, sensor materials should be designed to give the desired characteristics of sensor devices. These trends towards intelligent materials will be discussed here.  相似文献   

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In the cores of lattice defects (e.g. dislocations, grain boundaries, phase boundaries etc.) a special state of solid matter exists due to the forces (constraints) between the atoms (molecules) in the core region of the defects and the atoms (molecules) in the surrounding strained crystal lattices. These constraints result in the formation of a solid state structure characterized by a low density (typically 60 - 80 % of the crystal density) and a very broad distribution of nearest neighbour spacings. It is the basic idea of Nanostructured Materials to utilize the atomic structures formed in the cores of defects to generate a new class of materials. This goal is achieved by incorporating so many defects into a (formerly perfect) crystal that about 50 vol % of the material consists of defect cores. The results of studies by means of electron microscopy, neutron and x-ray diffraction, various types of spectroscopy and property measurements agree with these ideas. Nanostructured Materials exhibit properties that deviate (sometimes by many orders of magnitude) from the properties of crystals and glasses with the same chemical composition.  相似文献   

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Table A1 A matrix of 1369 structural variables of 20 coded amino acids and loading equations of 13 principle components(PCs)No. The variable name t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 1 Mdeosclericputloarrs w eight constitutional 0.0389 ?0.0008 0.016…  相似文献   

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In this article the world's potential energy reserves are summarized on the basis of available estimates, and the future energy consumption is estimated with the aid of a working hypothesis relating to the growth of the world's population (P) and the energy consumption per capita (γ). According to this estimate, the energy requirements in 30 years will be about seven times and in 80 years about fifty times as high as they are today, and all the concentrated energy sources will be exhausted in about 120 to 160 years. – The energy requirements in the steady state (Pγ = const.) could be of the order of 1013 MWh per year and could be met out of magmatic rocks (U,Th) and sea water (U,D). High priority should be given to research and development work on the construction, reliability, and safety of breeder and fusion reactors, the chemical treatment and final disposal of radioactive waste, the extraction of uranium, thorium, and deuterium from the “primitive” raw materials, the relevant problems relating to protection of the environment, and the worldwide control of the excess birthrate.  相似文献   

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A wide range of polymer materials for medical purposes based on polysiloxane developed at the State Research Institute of Building Structures is presented. The properties of compositions cured by both end hydroxyl groups and the reaction of hydroxylation are considered and examples of their applications are presented.  相似文献   

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The literature on open-framework materials has shown numerous examples of porous solids with additional structural, chemical, or physical properties. These materials show promise for applications ranging from sensing, catalysis and separation to multifunctional materials. This critical review provides an up-to-date survey to this new generation of multifunctional open-framework solids. For this, a detailed revision of the different examples so far reported will be presented, classified into five different sections: magnetic, chiral, conducting, optical, and labile open-frameworks for sensing applications. (413 references.)  相似文献   

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Energy recovery     
Incinerators in use, power-generating incinerators and pollution-prevention methods in energy recovery from waste incineration are briefly reviewed. Results of a recent energy recovery experiment under real operating conditions are described: The addition of waste plastic to municipal solid waste brought about more stable combustion and no increase in the concentrations of dioxins. It is remarked that energy recovery through incineration is probably the best currently available means of disposal for plastics which are too difficult to recycle.  相似文献   

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Several reference materials (RMs) and certified reference materials (CRMs) are widely used in Romania as measurement standards in different spectrochemical measurements. Among them, single element standard solution certified for their mass concentration play a key role in ensuring the required traceability of results expressed in this measurement unit. A short review of the locally available elemental RMs and CRMs used in atomic spectrometry or in other analytical techniques where aqueous standard solutions are required (usually called RMs or CRMs for spectrometry) is given. The experience of the INM in preparation and certification of such materials is described. Some aspects regarding their use for ensuring the accuracy and for confirmation of the traceability of analytical measurements, especially through calibration and metrological validation of main instrument performances, are discussed.  相似文献   

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We sought to improve the flame-retardant performance of wood-based materials through the development of a coating material using carbon-based materials. The coating materials were applied to the surfaces of wood-based materials used for interior materials and furniture. We measured fire characteristics of the coated wood-based materials using a cone calorimeter. The coating materials were prepared by the mixing of carbon materials, such as natural graphite, expandable graphite, and exfoliated graphite nanoplatelets, in water-based coating materials. TG analysis revealed that water-based coating materials/carbon material-blended composites had good thermal durability in the working temperature ranges. The flame-retardant performance was confirmed through cone calorimeter experiments, and the result of the experiment satisfied the standard for flame-retardant performance in ISO 5600-1.  相似文献   

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Several reference materials (RMs) and certified reference materials (CRMs) are widely used in Romania as measurement standards in different spectrochemical measurements. Among them, single element standard solution certified for their mass concentration play a key role in ensuring the required traceability of results expressed in this measurement unit. A short review of the locally available elemental RMs and CRMs used in atomic spectrometry or in other analytical techniques where aqueous standard solutions are required (usually called RMs or CRMs for spectrometry) is given. The experience of the INM in preparation and certification of such materials is described. Some aspects regarding their use for ensuring the accuracy and for confirmation of the traceability of analytical measurements, especially through calibration and metrological validation of main instrument performances, are discussed.  相似文献   

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Nanoscale diamond particles have become an interesting material. Due to their inertness, small size and surface structure, they are well-suited for biological applications, such as labelling and drug delivery. Here we discuss the surface structure and functionalisation of diamond nanoparticles. Non-covalent as well as covalent grafting of bioactive moieties is possible, and first applications of fluorescent diamond nanoparticles are described.  相似文献   

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