Materials Literature
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。
A large number of species usually placed in Fragilaria have been examined, mainly by scanning electron microscopy. As a result Fragilaria is more narrowly circumscribed, with F.capucina as the type species. Six species are definitely placed in Fragilaria and others noted for further investigation. Five genera are sepa…
The topology of the integral membrane protein MalF, which is required for maltose transport in Escherichia coli, has been analyzed using fusions of alkaline phosphatase (EC 3.1.3.1). The properties of such fusion strains support a MalF structure previously proposed on theoretical grounds. Several transmembrane segment…
This book comprises an introductory lecture outlining the basic concepts and challenges in the field. This is followed by a collection of reprinted articles which are important in understanding the subject. The book will focus mainly on mathematical and physical foundations of the subject rather than experimental prog…
This study concerns the influence of the concentration of Sr2+ and Ba2+ ions in mortar batch waters upon the hydration process of various Portland and additive cements. An increase in the mechanical resistence of said cements is observed, after 28 days, when the concentration of Ba2+ and Sr2+ ions in the mortar batch…
Not available
X-diffractometry is applied to evaluate the setting time of gypsum pastes. A direct "observation" of the crystalization phenomena, in the moment in which occurs is possible using the proper radiation, in the measure of the dimension what is observed. The observation is developed with normal techniques and instrumentat…
Abstract In some wide band gap halides of heavy alkali and alkaline‐earth metals (BaF 2 , CsCl, RbF etc.) the energy separation between the valence band involving mainly the halogen electronic states and the upper cation core band is smaller than the band gap. Under the excitation generating holes in the core band rad…
In this Work, which is the following of the others, the performance of a portland cement of a high initial resistance (P-550-ARI) —with a calculated content (Bogue) of 39.2 – 25.7 – 9.9 - 12.0 and 6.9% of C3S - C2S - C3A - C4AF and CaSO4 (II), respectively— is studied when it is submitted to the action of an magnesium…
We have carried out a series of accelerated artificial ageing tests to study the evolution of the silico-organic treatment products applied to calcareous materials of the Catedral of Oviedo. Test valoration has been made both by visual examination and weight loss measuring. We conclude by comparing different behaviour…
Laboratory testing to produce intergranular stress corrosion cracking (IGSCC) of Alloy 600 steam generator tubing in primary water environments can require lengthy exposure times, even at a temperature of 360 C (680 F). Recent testing of Alloy 600 in hydrogen-containing steam at 400 C (750 F) has shown the characteris…
The purpose of this work is to make the coupled cluster (CC) energy stationary with respect to molecular-orbital (MO) variations in the reference configuration. To achieve this, we have used the Z vector, the solution of a set of perturbation-independent CPHF-like equations, to rotate the MOs. A new energy and gradien…
Abstract A cation-exchange capacity (CEC) method based on ion-sieving properties was developed for the quantitative determination of clinoptilolite in soils. In this method, both zeolitic and non-zeolitic exchange sites in the soil sample are saturated with Na + . The CEC of the non-zeolitic exchange sites is determin…
To determine molecular architecture of the type IV collagen network in situ, the human amniotic basement membrane has been studied en face in stereo relief by high resolution unidirectional metal shadow casting aided by antibody decoration and morphometry. The appearance of the intact basement membrane is that of a th…
Abstract Experimental data on gas sorption and polymer swelling in glassy polymer—gas systems at elevated pressures are presented for CO 2 with polycarbonate, poly(methyl methacrylate), and polystyrene over a range of temperatures from 33 to 65°C and pressures up to 100 atm. The swelling and sorption behavior were fou…
Fibrin deposition is a consistent early event in solid tumors and healing wounds and precedes new blood vessel ingrowth in both. We now demonstrate that fibrin gels of themselves induce an angiogenic response in the absence of tumor cells or platelets. Angiogenesis was enhanced when certain chemoattractants or mitogen…
Abstract Dynamic mechanical measurements allow direct determination of the instant at which a network polymer gels. In such an experiment, the evolution of G ′( t ,ω 0 ) and G ″ ( t ,ω 0 ) is measured in small amplitude oscillatory shear as a function of cross‐linking time t . The frequency ω 0 is kept constant throug…
This review covers a wide range of experimental and theoretical studies of two-level or tunnelling states in glasses. Emphasis is on fundamental physics rather than a detailed comparison of experiment and theory. Sections cover the static and dynamic properties of tunnelling states, their contribution to thermal prope…
The weight of a phase in a mixture is proportional to the product of the scale factor, as derived in a multi-component Rietveld analysis of the powder diffraction pattern, with the mass and volume of the unit cell. If all phases are identified and crystalline, the weight fraction W of phase p is given by W_{p} = S_{p}…