Learning Stoichiometry with Hamburger Sandwiches
Simple and understandable activities involving the manufacturing of hamburgers can be used as an analogy for stoichiometric concepts and calculations.
Materials Literature
文献浏览
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
New Silicon-Containing Poly(Imide-Amide)s
New aromatic silicon-containing poly(imide-amide)s have been synthesized by solution polycondensation of various aromatic diamines having ether bridges between phenylene rings with a diacid chloride containing silicon. These polymers are easily soluble in polar amidic solvents such as N-methyl-pyrrolidinone or dimethy…
Direct synthesis of multi-walled and single-walled carbon nanotubes by spray-pyrolysis
In the present paper we report the simultaneous synthesis of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) by spray-pyrolysis, a type of chemical vapour deposition (CVD) method. The technical characteristics of the home-made experimental set-up are given. The synthesis involves the…
Temperature-dependent Presteady State Kinetics of Lumazine Synthase from the Hyperthermophilic Eubacterium Aquifex aeolicus
6,7-dimethyl-8-ribityllumazine synthase (lumazine synthase) catalyzes the condensation of 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione and 3,4-dihydroxy-2-butanone 4-phosphate. Presteady state kinetic experiments using the enzyme from the hyperthermophilic bacterium Aquifex aeolicus were monitored by multiwavelen…
Microstructural control of Nb addition in nanocrystalline hard magnets with different Nd content
The effects of Nb addition on the hard magnetic properties and microstructure evolution in Nd/sub 8/Fe/sub 78-x/Co/sub 8/B/sub 6/Nb/sub x/ and Nd/sub 12/Fe/sub 82-x/B/sub 6/Nb/sub x/ nanocrystalline alloys are presented. Low Nd containing alloys consist of /spl alpha/-Fe and Nd/sub 2/Fe/sub 14/B phases. The Nd/sub 12/…
Crystallization Measurements Using DTA Methods: Applications to Zerodur®
Differential thermal analysis (DTA) experiments described herein apply two methodologies by which to estimate absolute nucleation rates and/or temperature dependencies using a low‐expansion, commercially relevant, multicomponent glass‐ceramic as a test material. In particular, the Marotta and the Ray et al. methods we…
Effect of tetra ionic substitution on the dielectric properties of Cu-ferrite
X-ray diffraction (XRD), of the two systems of mixed ferrites Cu1+xTixFe2–2xO4 (where x = 0.0, 0.1, 0.2, 0.3, and 0.4); indicates that the samples of x = 0 (CuFe2O4) and x = 0.1 of the Cu–Ti system were formed in tetragonal structure and all other samples of the two system were formed in the cubic system. The ac condu…
Magnetic entropy change in the Ge-rich alloys Gd-Si-Ge
We have studied the temperature and field dependence of the magnetocaloric effect in the Ge-rich alloys Gd/sub 5/(Si/sub x/Ge/sub 1-x/)/sub 4/, where x=0.0825, 0.15, and 0.1875. The low field susceptibility shows a two-step magnetic ordering at the Curie temperature T/sub C/ and the Neel temperature T/sub N/. The T/su…
Visualization in atomistic and spin simulations
Certain basic demands from visualization code are common to all atomistic or spin systems; some are also relevant to more general visualization needs. Many commercial and homegrown visualization codes could meet these demands, but obviously the specific code used is less important than the fact that a visualization is…
Structure and phase transformation of ferromagnetic shape memory alloy Ni/sub 49/Mn/sub 30/Ga/sub 21/ fine particles prepared by spark erosion
Ni/sub 49/Mn/sub 30/Ga/sub 21/ fine particles were prepared by spark erosion. Most of the particles are spheres with sizes ranging from about 5 nm to 100 /spl mu/m. The particles have martensite structure at room temperature as indicated by X-ray diffraction (XRD). Measurements of the temperature dependence of the mag…
Current–Voltage Characteristics of Cobalt‐Doped Inversion Boundaries in Zinc Oxide Bicrystals
Undoped and cobalt‐doped basal inversion boundaries were fabricated in ZnO bicrystals to investigate their current–voltage characteristics. High‐resolution transmission electron microscopy observations and energy‐dispersive X‐ray spectroscopy analyses for a cobalt‐doped bicrystal revealed that the boundary was highly…
Defect analysis of a diamond particle detector by means of photoconductivity and thermal spectroscopy characterization
This paper deals with an investigation of the trapping mechanisms and the “pumping” process on a device based on polycrystalline Chemical Vapor Deposited (CVD) diamond, recently tested as particle tracker. Photoconductivity measurements have been carried out during monochromatic illumination from near IR to above band…
Modelling of Miscible Liquids with the Korteweg Stress
When two miscible fluids, such as glycerol (glycerin) and water, are brought in contact, they immediately diffuse in each other. However if the diffusion is sufficiently slow, large concentration gradients exist during some time. They can lead to the appearance of an “effective interfacial tension”. To study these phe…
Flame retardancy and heat resistance of phenol‐biphenylene‐type epoxy resin compound modified with benzoguanamine
Abstract The flame retardancy and heat resistance of a phenol‐biphenylene‐type epoxy resin compound, which forms a self‐extinguishing network structure, were increased by the inclusion of a benzoguanamine‐modified phenol biphenylene resin. The benzoguanamine‐modified phenol biphenylene resin contains a benzoguanamine…
New species of Fragilariforma (Bacillariophyceae) from New Zealand and Australia
Abstract Two new species of Fragilariforma, F. cassieae sp. nov. and F. rakiuriensis sp. nov., are described from material from New Zealand, with reference to populations found in Australia. The new species are similar in shape and size to Fragilariforma lata and F. hungarica var. tumida but are separated on the basis…
Polysaccharide Scaffolds Prepared by Crosslinking of Polysaccharides with Chitosan or Proteins for Cell Growth
The synthesis and characterization of sponges composed of polysaccharides crosslinked with different amine-containing natural polymers for the use as cell carriers is described. Sponges based on arabinogalactan, dextran, and amylose were synthesized by crosslinking with chitosan, or with the protein: gelatin, or bovin…
Photoelectronic, optical and electrical properties of TlInS2 single crystals
To specify the donor energy levels in TlInS2 single crystals, the dark electrical resistivity, photoconductivity and Hall measurements were carried out in the temperature range of 100–400 K, 110–350 K and 170–400 K, respectively. The Hall measurements revealed that the crystals exhibit an anomalous behavior of Hall vo…
Antiproliferative effect of chlorophyllin derived from a traditional Chinese medicine Bombyx mori excreta on human breast cancer MCF-7 cells
Chlorophyllin (CHL) is the sodium-copper salts of chlorophyll derivatives. In this study, the CHL was derived from a traditional Chinese medicine, the Bombyx mori excreta. The CHL, at concentrations 25-400 microg/ml, reduced the proliferation of HL-60, K-562, S-180, and MCF-7 cells by 8.2-95.7% after 72 h of incubatio…
Exchange interactions and curie temperature of Y-Co compounds
The Curie temperature of rare-earth Co intermetallics is investigated by self-consistent spin-polarized electronic-structure calculations on Y-Co compounds. The total exchange interaction of a given site with all other sites (J/sub o/) is calculated by the linear-muffin-tin-orbital method using the local force theorem…
Morphology and degradation of biodegradable poly(L‐lactide‐co‐β‐malic acid)
Abstract Poly( L ‐lactide‐co‐β‐malic acid) was obtained after the hydrogenolysis of the copolymer of L ‐lactide (L‐LA) and β‐benzyl malate (MA). 1 H‐NMR demonstrated that the composition of the copolymer was identical to the feeding dose. Thermal property study revealed the morphology of the copolymer could be changed…