Which Is the Real Determinant of MR Angiography Image Quality: Dose or Injection Protocol?

Lin, Kai; Zhang, Zhao Qi

doi:10.1148/radiol.2501081259

Cited by 5 publications

(16 citation statements)

References 4 publications

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“…For Ni‐LDO, the broad reduction peak located around 813 °C could be assigned to the reduction of Ni 2+ in MgNiO 2 solid solution, and the weak reduction peak around 386 °C to the reduction of Ni 2+ species on the surface. [ 40,41 ] From the area of the two reduction peaks of Ni‐LDO, MgNiO 2 is the main phase in Ni‐LDO, which is well consistent with the XRD results. For the Fe‐LDO catalyst, the reduction peak around 443 °C was attributed to the reduction of Fe 3+ to Fe 2+ and Fe 0 , whereas the reduction peak above 800 °C was attributed to the reduction of Fe 2+ to Fe 0 .…”

Section: Resultssupporting

confidence: 83%

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl₂O₄ Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Liu

Wang

et al. 2020

Energy Tech

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In view of the dual active sites mechanism of direct ethanol synthesis and the excellent catalytic performance of bimetallic catalysts, a series of Ni–Fe alloy catalysts with different Ni/Fe molar ratios derived from layered double hydroxides (LDHs) precursors are synthesized. During the calcination and reduction process of LDHs precursors, the Ni–Fe alloy is obtained, and attributed to all the elements being evenly dispersed at the atomic level in the LDHs precursors; meanwhile, a strong interaction between Ni–Fe alloy and MgAl2O4 support exists. As a result, Ni–Fe alloy nanoparticles are highly dispersed on the MgAl2O4 surface. The high CO adsorption ability on the Ni–Fe alloy and synergism catalysis between Ni and Fe result in excellent catalytic activity and high selectivity to ethanol on the bimetallic Ni–Fe alloy. In addition, the strong antisintering ability and stable alloy structure bring about a good catalytic stability. This research proposes a new catalytic system for direct ethanol synthesis from syngas.

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Section: Resultssupporting

confidence: 83%

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl₂O₄ Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Liu

Wang

et al. 2020

Energy Tech

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“…This suggests that the regeneration of fine Ni particles was smaller on the citrate-derived catalysts than on the HT-derived catalysts (vide infra). 4d and g), respectively, probably due to easy reduction of Ru or Pt followed by hydrogen spillover from the noble metals to Ni 2+ in the periclase or by the formation of alloy [13,14]. After steaming, the Ni reduction peak was separated into two peaks; one appeared between 282 and 327 °C and another was observed between 910 and 939 °C.…”

Section: Physicochemical Properties Of the Catalystsmentioning

confidence: 99%

“…The former is ascribed to NiO separated from Mg(Ni,Al)O periclase and the latter is due to the sintering of Mg(Ni,Al)O periclase of low Ni content [13,14]. When the catalysts after steaming were applied in the DSS PO, the peak around 280 °C still remained, whereas the peak around 920 °C disappeared and a new peak appeared between 530 and 564 °C.…”

Section: Physicochemical Properties Of the Catalystsmentioning

confidence: 99%

“…Ni can be oxidized not only by gaseous oxygen, but also even in the presence of steam [11]. A trace amount of noble metal doping on the Ni/Mg(Al)O catalysts leads not only to suppression of the Ni oxidation but also to self-regeneration of the active Ni species during the DSS SR of CH 4 [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

“…Differences were discussed focusing on both the activity and the sustainability due to the self-regeneration of active Ni particles. The HT method has been performed using the same amount of nitrates of Ni(II), Mg(II) and Al(III) as the citrate method following the previous works [11][12][13][14];…”

Section: Introductionmentioning

confidence: 99%

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Citrate or hydrotalcite?

Zhan

Nishida

et al. 2009

Applied Catalysis A: General

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Trace amounts of Pt-and Ru-doped Ni/Mg(Al)O catalysts were prepared by a citrate method and tested in the oxidative reforming of C 3 H 8 under daily start-up and shutdown (DSS) operation. The activity and the sustainability of the catalysts were compared with those of the Pt-and Ru-doped Ni/Mg(Al)O catalysts derived from hydrotalcite (HT) precursor. The DSS operation of C 3 H 8 reforming was carried out with O 2 gas or O 2 /H 2 O mixed gas between 200 ºC and 600 or 700 ºC under air purging conditions. The catalysts underwent steaming treatment with H 2 /H 2 O mixed gas at 900 ºC for 10 h. This allowed us to test the effect of Ni sintering on the catalyst deactivation. Coking was significantly suppressed on both HT-and citrate-derived Ni catalysts. Although both preparations produced highly dispersed Ni particles on the catalysts, the HT-derived catalysts exhibited more finely dispersed Ni particles, resulting in higher activity values than those of the citrate-derived catalysts. The regenerative activity due to redispersion of sintered Ni particles was enhanced over the HT-derived catalysts compared with the activity over citrate-derived catalysts. Although a clear redispersion of Ni particles was not observed in the oxidative reforming, i.e., in the absence of steam, the size decrease in Ni particles was more significant over the HT-derived catalysts than over the citrate-derived catalysts. The Mg(Al)O periclase structure derived from Mg-Al HT likely plays an important role in the regenerative activity of Pt-and Ru-Ni/Mg(Al)O catalysts. Pt-doping was more effective than Ru for the catalyst sustainability in the oxidative reforming of C 3 H 8 .

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Superior catalytic behavior of trace Pt-doped Ni/Mg(Al)O in methane reforming under daily start-up and shut-down operation

Nishida

Zhan

et al. 2008

Applied Catalysis A: General

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Doping effects of Pt and Ru on Ni/Mg(Al)O catalysts were compared in daily start-up and shutdown operations of steam reforming of CH 4. Trace Pt-doped catalyst showed better behavior than trace Ru-doped catalyst; the former was self-activated but the latter was not, although both exhibited self-regenerative activity. Moreover, the former exhibited sustainable activity, although the latter was quickly passivated, in the autothermal reforming of CH 4. Formation of Pt-Ni alloy on the surface of fine Ni metal particles on the catalysts was suggested by EXAFS analyses. CH 4 was dissociatively activated to form hydrogen on Pt, assisted by adsorbed O or OH species, leading to the self activation via Ni reduction by hydrogen spillover from Pt. The self-regeneration of the Pt-Ni/Mg(Al)O catalysts can be achieved by the continuous rebirth of active Ni metal species via reversible reduction-oxidation between Ni 0 and Ni 2+ in/on Mg(Ni,Al)O periclase assisted by the hydrogen spillover.

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Which Is the Real Determinant of MR Angiography Image Quality: Dose or Injection Protocol?

Cited by 5 publications

References 4 publications

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl₂O₄ Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl₂O₄ Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Citrate or hydrotalcite?

Superior catalytic behavior of trace Pt-doped Ni/Mg(Al)O in methane reforming under daily start-up and shut-down operation

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Which Is the Real Determinant of MR Angiography Image Quality: Dose or Injection Protocol?

Cited by 5 publications

References 4 publications

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl2O4 Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl2O4 Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Citrate or hydrotalcite?

Superior catalytic behavior of trace Pt-doped Ni/Mg(Al)O in methane reforming under daily start-up and shut-down operation

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Product

Resources

About

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl₂O₄ Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Highly Dispersed Ni–Fe Alloy Catalysts on MgAl₂O₄ Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas