Dislocation structures in
1
¯
12
Cu-7 at. pct Al alloy single crystals cyclically deformed at different plastic strain amplitudes were investigated by transmission electron microscope (TEM) and ...compared with the results of
1
¯
12
Cu single crystals. It is found that the plastic strain amplitude
γ
pl
has an obvious effect on the slip deformation mode, and consequently on the cyclic hardening behavior of
1
¯
12
Cu-7 at. pct Al alloy single crystals with an intermediate stacking fault energy. For instance, a high slip planarity (
i.e.
, only formation of planar-slip bands) contributes to the occurrence of a gentle cyclic hardening with a much lower saturation stress at a low
γ
pl
of 4.5 × 10
−4
. A mixed planar/wavy-slip mode (
e.g.
, persistent Lüder’s bands/wall-like microstructures) at an intermediate
γ
pl
of 2.2 × 10
−3
causes an obvious cyclic hardening up to a comparable saturation stress to that for the
1
¯
12
Cu single crystal. In contrast, the deformation mode is dominated by wavy slip (
e.g.
, ill-defined dislocation cells and walls) at the highest
γ
pl
of 7.2 × 10
−3
, causing that its cyclic hardening curve is quite similar to that for the
1
¯
12
Cu single crystal; in this case, a slightly higher saturation stress level than that for the Cu single crystal is reached due to the additional solid solution strengthening.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A light scalar X0 or vector X1 particles have been introduced as a possible explanation for the (g−2)μ anomaly and dark matter phenomena. Using (8.998±0.039)×109 J/ψ events collected by the BESIII ...detector, we search for a light muon philic scalar X0 or vector X1 in the processes J/ψ→μ+μ−X0,1 with X0,1 invisible decays. No obvious signal is found, and the upper limits on the coupling g′0,1 between the muon and the X0,1 particles are set to be between 1.1×10−3 and 1.0×10−2 for the X0,1 mass in the range of 1<M(X0,1)<1000 MeV/c2 at 90% credibility level.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Inflammation and cancer are the two major disorders in the gastrointestinal tract. They are causally related in their pathogenesis. It is important to study animal models' causal relationship and, in ...particular, to discover new therapeutic agents for such diseases. There are several criteria for these models in order to make them useful in better understanding the etiology and treatment of the said diseases in humans. In this regard, animal models should be similar as possible to human diseases and also be easy to produce and reproducible and also economic to allow a continuous replication in different laboratories. In this review, we summarize the various animal models for inflammatory and cancerous disorders in the upper and lower gastrointestinal tract. Experimental approaches are as simple as by giving a single oral dose of alcohol or other noxious agents or by injections of multiple dosages of ulcer inducing agents or by parenteral administration or in drinking water of carcinogens or by modifying the genetic makeups of animals to produce relatively long-term pathological changes in particular organs. With these methods they could induce consistent inflammatory responses or tumorigenesis in the gastrointestinal mucosa. These animal models are widely used in laboratories in understanding the pathogenesis as well as the mechanisms of action for therapeutic agents in the treatment of gastrointestinal inflammation and cancer.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Porous titania film is prepared by alkali treatment of NiTi alloy followed by soaking treatment in HCl solution. The benefit of this porous titania film as an interlayer to improve adhesion and ...integrity of the sol–gel titania coating on NiTi alloy substrate is evidenced by surface morphological observations. X-ray diffraction analyses indicate the formation of Ni
4
Ti
3
phase in the matrix during heat treatment of the NiTi samples. X-ray photoelectron spectroscopy results indicate that the titania coating with two dip-coating layers has completely covered the NaOH–HCl treated NiTi substrate, and potentiodynamic polarization tests show that this titania coating provides good protection for the treated NiTi substrate in 0.9% NaCl solution. Ultraviolet illumination can increase surface hydrophilicity of the NiTi samples by reducing contact angles from 60–80° to 20–10°.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Duplex-treated composite ceramic coatings with and without compound layer were produced by the combination of plasma nitrocarburizing and follow-up multi-arc ion plating. The microstructures and ...mechanical properties of the ceramic coatings were investigated by means of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy, in association with property characterization. The results show that the composite ceramic coatings are composed of an inner nitrocarburized layer, a CrN interlayer and an outmost AlCrTiSiN layer. The AlCrTiSiN layer consists mainly of alternately nanoscaled (Cr,Al)N sublayer and amorphous sublayer with a few (Ti,Al)N phases embedded in a matrix of amorphous Si3N4 and Si. The compound layer has transformed to the γ′-phase sublayer, which enhances considerably the adhesion strength of the CrN interlayer to compound layer. The improved adhesion strength is attributed to the γ′-phase acting as nucleation sites of epitaxial growth for the CrN phase. The composite ceramic coating with compound layer reveals much higher hardness, bearing capacity and wear resistance when compared with the composite ceramic coating without compound layer. The improvement of mechanical and tribological properties is associated with presence of the γ′-phase sublayer, which provides a smooth transition, gradient in hardness and stress between the substrate and the CrN/AlCrTiSiN coating. In addition, the hard γ′-phase sublayer provides a strong supporting effect for CrN/AlCrTiSiN layer under loading.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The effect of bismuth on hydrogen evolution on lead in sulfuric acid solution is investigated by linear potential sweep, alternating current (ac) impedance, X-ray diffraction (XRD) and ...hydrogen-collection experiments. First, hydrogen evolution behaviour on commercial lead with and without bismuth and on pure bismuth is compared. It is found that the hydrogen evolution reaction takes place more easily on bismuth than on lead, but that the commercial lead with 50
ppm bismuth has a slower hydrogen evolution than the commercial lead without bismuth. Next, the effect of bismuth is studied. Bismuth is added to lead at 0–7.33
wt.% to make lead–bismuth alloys, or is deposited chemically on the surface of lead to form a bismuth-containing lead. The results from X-ray diffraction show that the prepared lead–bismuth alloys have the same crystal structure as pure lead, i.e., the added bismuth enters into the lead crystals. Apparently, chemically-deposited bismuth does not enter into the lead crystals, but is independent of but contact electronically with the lead. The results, obtained from linear potential sweep, ac impedance and hydrogen evolution volume measurements, show that the rate of hydrogen evolution depends on the amount of bismuth in or on the lead. It is concluded that bismuth accelerates the hydrogen evolution reaction on lead, irrespective of whether it enters the lead crystals or not. By contrast, the hydrogen evolution reaction is less dependent on bismuth in lead–bismuth alloys than on bismuth that is chemically deposited on lead and the effect of bismuth can be neglected if the alloy electrode is not taken to a very negative potential.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
PDF
