Preliminary study of regulation technology of wind field distribution on QTT site based on test of equivalent wind field

The effect of wind gust on the large reflector antenna is one of the main factors that can affect the antenna performance and therefore, this effect must be minimized to meet the strict performance requirement in the world largest steerable telescope, which is QiTai Telescope (QTT). In this paper, the characteristics of the topography as well as the wind distribution around QTT site have been analyzed and consequently, a technology for improving the wind distribution in an active way has been proposed. Additionally, an equivalent wind distribution test rig for the proposed technology has been built in the lab and the corresponding experiment has been carried out. The experimental data indicated that the proposed technology was a promising tool for regulating the wind distribution for the large reflector antenna and it was found that the proposed technology can significantly reduce the wind speed as well as the wind impact range after the wind regulation has been given in the test. The results in this paper has provided a solid foundation for the regulation of the wind distribution of the QTT site

Novel method of boundary-free mesh parameterization.

Unless the targeted mesh is developable, metric distortion is inevitable during the process of surface mesh parameterization, thus one important objective of all involved parametric studies is to reduce the metric distortion. In order to further reduce area and angle distortion, a novel method of boundary-free mesh parameterization is presented in the paper. Firstly, the initial boundary-fixed conformal parameterization from 3D surface mesh patch to a plane is performed in the method. Then, based on the initial parameterization, the iterations of boundary-free quasi-harmonic parameterization are developed, where the tensor field is updated in each iterative step and the principal curvature direction is utilized to terminate the iteration. The solution of the novel method is convenient to calculate since it involves a series of linear systems. In our novel parameterization method, lower metric distortion and considerable efficiency have been obtained in experiments

QTL analysis of L<i>er/</i>Cvi RIL population for primary root length under 40 mM CaCl₂ condition.

<p>LOD score values from multiple-QTL model mapping (MQM) analysis of traits plotted against a linear representation of the <i>Arabidopsis</i> genome. Red lines represent LOD score values. Dashed lines indicated the threshold value. Four QTLs were identified in chrom.1, 2, and 5 and named response to high calcium (<i>RHCA</i>) 1–4.</p

The response of L<i>er</i>/Cvi near-isogenic lines (NILs) containing QTLs on chromosome 1 and 5 to high calcium.

<p>(A) Analysis of primary root length of L<i>er</i>/Cvi NIL lines grown on different medium. Data presented as means ± SD (n≥5). The different lowercase letters on the bars indicate significantly different means (P<0.05). (B) The graphic genotypes of NIL lines. White column indicates L<i>er</i> genome, and black column indicates Cvi introgression fragment.</p

Frequency distribution of primary root length of L<i>er</i>/Cvi RIL population grown under 40 mM CaCl₂ condition.

<p>Arrows indicate the levels in the parental lines: L<i>er</i> and Cvi.</p

The primary root length of L<i>er</i> and Cvi seedlings on different medium with high CaCl_2, NaCl and KCl.

<p>(A) Pictures of L<i>er</i> and Cvi seedlings grown on different medium (Scale bar = 1 cm). (B) Primary root length analysis of L<i>er</i> and Cvi seedlings grown under different conditions. Average values ± SD are shown (n = 5). The different lowercase letters on the bars indicate significantly different means (P<0.05).</p

Promotional Effect of Carbon on Fe Catalysts for Ammonia Decomposition: A Density Functional Theory Study

Density functional theory calculations have been performed to investigate the recombinative desorption of N on terraced Fe(100) and Fe(110) as well as stepped Fe(111) and Fe(211) surfaces. The results showed that the stepped surfaces, especially the Fe(111) surface, are more active than the terraced surfaces, which could be related to the presence of so-called C₇ sites for the stepped surfaces. Carbon atoms were found to stabilize the thermodynamically unstable stepped surfaces to be the energetically favored facets and thus facilitate the preferential exposure. As these carbon atoms incorporated into the stepped surfaces in the form of surface or subsurface carbon, the activation energy for the recombinative desorption of N was lowered, which was mainly ascribed to the decrease in the d band center of surface Fe atoms. In addition, a relation between the electronic and structural properties of Fe catalysts in the absence or presence of carbon and ammonia decomposition activity was also correlated

Natural variation of high Ca response in <i>Arabidopsis</i>.

<p>(A–C) Pictures of different <i>Arabidopsis</i> accessions grown on medium with or without 40 and 50 mM CaCl₂ (Scale bar = 1 cm). Shakdara (Sha, N929), Cape Verde Islands (Cvi, N902), Landsberg <i>erecta</i> (L<i>er,</i> N1642), An-1(N99), Columbia (Col-0, N1092), Eri. (D) Analysis of primary root length of <i>Arabidopsis</i> accessions under different calcium conditions. Data presented as means± SD (n≥3). The different lowercase letters on the bars indicate significantly different means (P<0.05).</p

Reconfiguring Molecular Conformation from Comb-Type to Y‑Type for Improving Dispersion Performance of Polycarboxylate Superplasticizers

Steric repulsive force is the main dispersion force between cement particles. In order to improve the dispersibility of polycarboxylate superplasticizers (PCEs), we designed and synthesized a new Y-type macromonomer (YPEG) with a molecular weight of Mw = 4100 Da. A long side chain-branched polycarboxylate superplasticizer (YPCE) was successfully synthesized by employing YPEG. Several common comb PCEs having the same side chain density but different lengths, such as PCE2400 and PCE4000, are employed to compare with YPCE for evaluating the dispersion performance. The results show that YPCE has a more excellent dispersion performance than the common PCEs under different water–cement ratios. Additionally, YPCE shows stronger water reduction for concrete. Furthermore, a dynamic light scattering study elucidates that YPCE can increase the adsorbed layer thickness from 5.6 to 7.9 nm, thus forming stronger steric hindrance. Simulations using molecular dynamics are conducted to investigate the influence of the conformational transformation of PCEs from comb-type to Y-type on the adsorption configuration and radius of gyration (Rg) of PCEs on calcium silicate hydrate surface. It is observed that the side chain of YPCE remains in an extended state, and Rg fluctuates little during the fitting process. This study provides a new strategy to enhance the steric hindrance of PCEs