Bis[μ-2-(2-naphth­oxy)acetato]bis­{aqua[2-(2-naphth­oxy)acetato]zinc(II)}

The title binuclear ZnII compound, [Zn2(C12H9O3)4(H2O)2], is centrosymmetric. Each Zn atom is coordinated by two bridging 2-naphthoxyacetate anions, one terminal 2-naphth­oxy­acetate anion and one water mol­ecule in a distorted ZnO4 tetra­hedral geometry. The naphthalene system of the bridging ligand is nearly perpendicular to the naphthalene of the terminal ligand, with a dihedral angle of 78.26 (6)°. Within the binuclear mol­ecule the Zn⋯Zn separation is 3.815 (5) Å. In the crystal structure, inter­molecular O—H⋯O hydrogen bonding between the water mol­ecule and carboxyl­ate groups helps to stabilize the crystal structure

Heat Transfer and Evaporation Mathematical Model of LNG covered by High Expansion Foam

PresentationWith the expanding of liquefied natural gas (LNG) usage, its security hidden trouble appeared gradually. For security reasons, small-scale experiment was carried out using LN2 (whose thermal physical property parameters is similar to that of LNG, and do not affect the validity of the study) instead of LNG. Observing high expansion foam physical structure after it covering LN2, we find out there's a three layer structure above the LN2 at stable stage, the ice layer (including the tentacles below), freezing foam layer and the foam layer. Through observation and analysis, we build a physical structure model of the foam. A new method to calculate thin film thickness using expansion ratio is proposed, and a heat transfer and evaporation model between foam and LNG in the initial stage is established. Also we build a physical structure model of the ice, and establish a heat transfer and evaporation model between ice and LNG in stable stage. Combined with heat transfer between LNG, ground and cofferdam, the heat transfer and evaporation model of LNG covered with foam was developed eventually

Interaction of XRCC1

Background. To explore the correlation between the Arg399Gln polymorphism and susceptibility to esophageal cancer in Korean and Han Chinese individuals in Harbin, China, and its potential interaction with alcohol consumption. Methods. This prospective study included 203 patients with esophageal squamous cell carcinoma; 88 were of Korean descent and 115 were of Han Chinese descent. A group of healthy controls included 105 participants of Korean descent and 105 of Han Chinese descent. Genotyping of the Arg399Gln locus of XRCC1 was performed by PCR-RFLP. Results. The allelic and genotypic frequencies were not significantly different between individuals with esophageal cancer and controls or between individuals of Korean and Han Chinese descent (P>0.05). However, when individuals with the wild-type Arg/Arg genotype also consumed alcohol, the risk of esophageal cancer was lower (OR = 3.539; 95% CI = 2.039–6.142; P<0.05). Conclusions. The XRCC1 Arg399Gln polymorphism does not appear to be associated with esophageal cancer in individuals of Korean or Han Chinese descent in Harbin, China. However, alcohol consumption may decrease the risk of esophageal cancer in persons with the wild-type genotype

Neutron Scattering off One-Neutron Halo Nuclei in Halo Effective Field Theory

Neutron scattering off neutron halos can provide important information about the internal structure of nuclei close to the neutron drip line. In this work, we use halo effective field theory to study the $s$-wave scattering of a neutron and the spin-parity $J^P=\frac{1}{2}^+$ one-neutron halo nuclei $^{11}\rm Be$, $^{15}\rm C$, and $^{19}\rm C$ at leading order. In the $J=1$ channel, the only inputs to the Faddeev equations are their one-neutron separation energies. In the $J=0$ channel, the neutron-neutron scattering length and the two-neutron separation energies of $\rm ^{12}Be$, $\rm ^{16}C$ and $\rm ^{20}C$ enter as well. The numerical results show that the total $s$-wave cross sections in the $J=1$ channel at threshold are of the order of a few barns. In the $J=0$ channel, these cross sections are of the order of a few barns for $n$-$^{11}\rm Be$ and $n$-$^{19}\rm C$ scattering, and about 60 $\rm mb$ for the $n$-$^{15}\rm C$ scattering. The appearance of a pole in $p\cot\delta$ close to zero in all three cases indicates the existence of a virtual Efimov state close to threshold in each of the $^{12}\rm Be$, $^{16}\rm C$, and $^{20}\rm C$ systems. Observation of this pole would confirm the presence of Efimov physics in halo nuclei. The dependence of the results on the neutron-core scattering length is also studied

Minimal-time Deadbeat Consensus and Individual Disagreement Degree Prediction for High-order Linear Multi-agent Systems

In this paper, a Hankel matrix-based fully distributed algorithm is proposed to address a minimal-time deadbeat consensus prediction problem for discrete-time high-order multi-agent systems (MASs). Therein, each agent can predict the consensus value with the minimum number of observable historical outputs of its own. Accordingly, compared to most existing algorithms only yielding asymptotic convergence, the present method can attain deadbeat consensus instead. Moreover, based on the consensus value prediction, instant individual disagreement degree value of MASs can be calculated in advance as well. Sufficient conditions are derived to guarantee both the minimal-time deadbeat consensus and the instant individual disagreement degree prediction. Finally, both the effectiveness and superiority of the proposed deadbeat consensus algorithm are substantiated by numerical simulations.Comment: 12 pages, 3 figure