66 research outputs found
[RuCl<sub>2</sub>(<i>p-</i>cymene)]<sub>2</sub>âCatalyzed Conjugate Addition of Arylboronic Acids to α,ÎČ-Unsaturated Ketones under Ligand-Free and Neutral Conditions
A simple
and efficient Ru-catalyzed conjugate addition reaction
of arylboronic acids to α,ÎČ-unsaturated ketones under
neutral conditions without any additional ligands has been developed.
This RuÂ(II)-catalytic system both fulfilled the inhibition of the
ÎČ-hydride elimination in the catalytic cycle and minimized the
protonolysis of arylboronic acids
Surface properties, micellar molecular interaction, and physical properties for binary systems of sodium oleate with three anionic surfactants
<p>The mixed micellization of the anionic surfactant sodium oleate (NaOL) and three anionic surfactants (NaDC, AOT, SDS) of different structures in 0.01 mol/L NaCl solution was investigated by surface tension measurement at different temperatures. All the investigated mixtures exhibited nonideal behaviors as the experimental critical micelle concentration (<i>CMC</i>) values were less than the values calculated by using the Clintâs equation. Negative ÎČ<sup>m</sup> values calculated by using Rubinghâs equation and |ln(<i>CMC</i><sub>1</sub>/<i>CMC</i><sub>2</sub>)| < |ÎČ<sup>m</sup>| proved synergism in the three systems of higher α<sub>NaOL</sub> or lower <i>α</i><sub>NaOL</sub>. An interesting phenomenon of double inflection points was observed for pure NaOL and mixtures of high <i>α</i><sub>NaOL</sub>. The negative Î<i>G</i><sup>0</sup><sub>m</sub> values for the mixed systems imply that the micelle formations are spontaneous process. The NaOL/NaDC system was also studied in buffer solution (pH 8, 12) at 30°C which also exhibited nonideal behavior. Synergism existed at pH 12 but not at pH 8 for the NaOL/NaDC system. It is noteworthy that there were no double inflection points for NaOL/NaDC system in buffer solution (pH 8, 12). Krafft point and calcium stability data show that these three anionic surfactants can improve the water solubility and hard-water resistance of soap.</p
DataSheet1_Velocity changes after the 2021 MS 6.4 Yangbi earthquake based on passive image interferometry.docx
An MS 6.4 earthquake occurred in Yangbi, Yunan Province, China, on 21 May 2021. The epicenter was on the blind branch fault in the west of the WeixiâQiaohouâWeishan fault, but no surface rupture was obvious. In the present study, the continuous vertical component of waveforms that were recorded in six nearby permanent stations was collected and the noise cross-correlation and autocorrelation techniques were utilized to investigate velocity changes that were induced by the Yangbi Earthquake. Velocity changes based on the single-station autocorrelation method reveal mainly coseismic declines, and a maximum of .09% was recorded in the EYA station. Results from the cross-correlation technique show both positive and negative velocity changes, and these lasted for approximately 3Â months. The volumetric strain that was generated by the Yangbi Earthquake at a depth of 5Â km exhibits an obvious four-quadrant distribution. Station pairs in the dilatation region (e.g., EYAâHEQ) mainly display a decrease in velocity, whereas those in the contraction region (e.g., BASâTUS, TUSâYUL, and LUSâTUS) show an increase in velocity. Based on the depth sensitivity of scattered waves, velocity changes that were obtained using the noise cross-correlation involve the highest weight coefficients near the related two stations. Regarding stations of one station pair in different stress loading regions, the static stress of the station that is nearest to the epicenter exerted a greater impact on the velocity change. The observed velocity changes are likely attributed to a combination of near-surface physical damage and static stress changes. The validation of clock errors with magnitudes of seconds that were obtained using the noise cross-correlation and effects of these errors on measured velocity changes are also discussed.</p
Additional file 1 of ANXA1 is identified as a key gene associated with high risk and T cell infiltration in primary sclerosing cholangitis
Additional file 1. Details of 185 DEGs
Carbide-Forming Groups IVB-VIB Metals: A New Territory in the Periodic Table for CVD Growth of Graphene
Early
transition metals, especially groups IVB-VIB metals, can
form stable carbides, which are known to exhibit excellent ânoble-metal-likeâ
catalytic activities. We demonstrate herein the applications of groups
IVB-VIB metals in graphene growth using atmospheric pressure chemical
vapor deposition technique. Similar to the extensively studied Cu,
Ni, and noble metals, these transition-metal foils facilitate the
catalytic growth of single- to few-layer graphene. The most attractive
advantage over the existing catalysts is their perfect control of
layer thickness and uniformity with highly flexible experimental conditions
by in situ converting the dissolved carbons into stable carbides to
fully suppress the upward segregation/precipitation effect. The growth
performance of graphene on these transition metals can be well explained
by the periodic physicochemical properties of elements. Our work has
disclosed a new territory of catalysts in the periodic table for graphene
growth and is expected to trigger more interest in graphene research
Energy and multivariable adjusted relationship between dietary vitamin C intake and NAFLD.
<p>Energy and multivariable adjusted relationship between dietary vitamin C intake and NAFLD.</p
Solubility of 3,7,9,11-Tetraoxo-2,4,6,8,10-pentaaza[3.3.3] Propellane (TOPAP) in Different Pure Solvents at Temperatures between 273.15 and 318.15 K
The
solubility of 3,7,9,11-tetraoxo-2,4,6,8,10-pentaaza[3.3.3]Âpropellane
(TOPAP) was measured in pure H<sub>2</sub>O and 11 other organic solvents,
including methanol, acetonitrile, acetone, ethyl acetate, ethanol,
tetrahydrofuran, <i>n</i>-propanol, <i>i</i>-propanol,
dioxane, ethylene glycol, and toluene in the temperature range from
273.15 to 318.15 K at an interval of 5 K by the equilibrium method
with ultraviolet detection. For all reagents selected, the results
showed that the solubility data of TOPAP increased with increasing
temperature. All of the obtained experimental results in all mentioned
solvents were correlated with temperature by using the ideal solution
model, Apelblat model, Yaws model, λ<i>h</i> equation,
and NRTL model. The ideal solution model, Apelblat model, Yaws model,
and λ<i>h</i> equation are more suitable for the correlations
of solubility of TOPAP, and they have a smaller maximum relative average
deviation
Insight into the Bonding Mechanism and the Bonding Covalency in Noble GasâNoble Metal Halides: An NBO/NRT Investigation
The bonding between
noble gas and noble metal halide like hydrogen
bonding (H-bonding) motivates us to investigate the bonding mechanism
and the bonding covalency in NgMX (Ng = He, Ne, Ar, Kr, Xe, Rn; M
= Cu, Ag, Au; X = F, Cl, Br, I) complexes using natural bond orbital
(NBO) and natural resonance theory (NRT) methods. In this study, we
introduce the new resonance bonding model in H-bonding into NgMX bonding.
We provide strong evidence for resonance bonding involving two important
resonance structures: Ng:âŻMâX â Ng<sup>+</sup>âMâŻ:X<sup>â</sup> in each of NgMX complexes,
originating in the n<sub>Ng</sub> â Ï*<sub>MX</sub> hyperconjugative
interaction. The covalency of the bonding could be understood by the
localized nature of NgâM bonds in these two resonance structures,
and the degree of NgâM covalency can be quantitatively described
by calculated NRT bond orders <i>b</i><sub>NgM</sub>. Furthermore,
we find that the bond order satisfies conservation of bond order, <i>b</i><sub>NgM</sub> + <i>b</i><sub>MX</sub> = 1, for
all of the studied complexes. On the basis of the conservation of
bond order and some statistical correlations, we also reveal that
the NgâM bond (except HeâAg and NeâAg bonds)
can be tuned by changing the auxiliary ligand X. Overall, the present
studies provide new insight into the bonding mechanism and the covalency
of the bonding in noble gasânoble metal halides, and develop
one resonance bonding model
Subgroup analysis of multivariable-adjusted relationship between dietary vitamin C intake and NAFLD.
<p>Subgroup analysis of multivariable-adjusted relationship between dietary vitamin C intake and NAFLD.</p
Basic characteristics of the study population (n = 3471).
<p>Basic characteristics of the study population (n = 3471).</p
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