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A novel and thermally stable aluminum phosphate Li6Na3Sr14Al11P22O90 (1) has been achieved by using a solid-state molten method, which contains an oxo-centered trinuclear cluster and an anti-Lowenstein's rule Al–O–Al linkage and is constructed from two types of (3,6)-connected kgd layers [Al(Al3O)(PO4)7]25− and [Al(PO4)2]3−. The good optical transparency in the whole UV range and excellent thermal stability make the title compound a potential optical window material. [ABSTRACT FROM AUTHOR]

Nitrogen is often released in pulses with different frequencies, and N supply pulses may affect growth, reproduction, and biomass allocation of plants. However, few studies have examined how N supply pulses affect intraspecific competition of clonal plants and whether such an effect depends on the N supply amount. We grew one (no competition) or 12 ramets (with intraspecific competition) of both an invasive clonal plant Alternanthera philoxeroides and its native congener Alternanthera sessilis in five different N treatments: control (no N addition), low/high amount with low/high frequencies (pulses). Nitrogen addition significantly increased the growth of both species, while intraspecific competition decreased it. Nitrogen addition significantly increased intraspecific competitive intensity of A. philoxeroides as measured by the log response ratio of growth traits, but did not affect that of A. sessilis. Despite the N supply amount, N pulses had little effect on the growth and thus intraspecific competition of the two species. Therefore, increasing N deposition may change population structure and dynamics and the invasion succession of A. philoxeroides, but changes in N pulses may not. [ABSTRACT FROM AUTHOR]

Solid solution is a potential way to optimize thermoelectric performance for its low thermal conductivity compared to those of the constituent compounds because of the phonon scattering from disordered atoms. Tin(ii) sulfide (SnS) shows analogous band structure and electrical properties with tin selenide (SnSe), which was the motivation for investigating the thermoelectric performance of SnS and SnS–SnSe solid solution system. SnS compound and SnS1−xSex (0 ＜ x ＜ 1) solid solution were fabricated using the melting method and they exhibited anisotropic thermoelectric performance along the parallel and perpendicular to the pressing directions. For the SnS compound, the maximum zT value is 0.19 at 823 K along the parallel to pressing direction, which is higher than that along the perpendicular to the pressing direction (zT⊥ = 0.16). The zT values of SnS0.5Se0.5 and SnS0.2Se0.8 were higher than those of the SnS compound and a maximum zT value of 0.82 was obtained for SnS0.2Se0.8 at 823 K, which is more than four times higher than that of SnS. [ABSTRACT FROM AUTHOR]

We conducted a greenhouse experiment to test how clonal integration affected the growth responses of Spartina anglica to light intensity heterogeneity in light availability and whether such effects depended on contrast light intensity. The experiment had three homogeneous treatments and two heterogeneous treatments. In the homogeneous treatments, both ramets of a connected ramet pair were unshaded (high light intensity), moderately shaded (medium light intensity, 70% of the high light intensity) and deeply shaded (low light intensity, 30% of the high light intensity). In the heterogeneous treatments, one ramet of a pair was unshaded, but its connected ramet was either moderately shaded (low light intensity contrast) or deeply shaded (high light intensity contrast). In the homogeneous treatments, biomass of S. anglica was significantly higher in the high light intensity treatment than in the medium and low light intensity treatments. Number of leaves, root length, and total biomass were significantly higher in the shaded ramet in the heterogeneous treatment with low light intensity contrast than in the ramet in the homogeneous treatment with medium light intensity. Final size and mass were not significantly different between the unshaded ramet in the heterogeneous treatment with low light intensity contrast and the ramets in the homogeneous high light intensity treatment. These results suggested that clonal integration benefitted a shaded ramet with little cost to an unshaded ramet when contrast in light intensity was low. However, effects of clonal integration were not significant when contrast was high. It therefore appeared that effects of clonal integration on the growth of S. anglica did not increase with increasing light intensity contrast. In natural habitats, clonal integration might improve growth of S. anglica when its ramets are moderately shaded by other plants but not when they are deeply shaded. [ABSTRACT FROM AUTHOR]

Selenene has been predicted as a new member of an atomically thin 2D crystalline material family as of last year. With first principle calculations, two different stable phases of selenene, one with the 1T‐MoS2‐like structure (α‐Se) and the other with alternating arrangement structure of deformed four‐membered and six‐membered rings (b‐Se) are identified. Further research indicates that monolayer α‐Se exhibits excellent bipolar conductivity, possessing rather high hole mobility close to that of graphene, and monolayer b‐Se shows a robust in‐plane spontaneous electric polarization of 13.46 mC cm−2 and a polarization reversing barrier of 422 meV per unit cell. The findings offer a promising material for high speed electronic devices and broaden the family of 2D ferroelectric materials, especially the family of elemental ferroelectric materials. This study demonstrates that selenene (Se) exits in two stable structures with multivalency nature. Monolayer α‐Se possesses a rather high carrier mobility, while monolayer β‐Se has a considerable in‐plane spontaneous polarization. The findings provide a promising material for high speed electronic devices and offer an understanding of elemental ferroelectricity. [ABSTRACT FROM AUTHOR]

High-power solid-state lasers with good beam quality are attracting great attention on account of their important applications in industry and military. However, the thermal effects generated in the laser host materials seriously limit power scaling and degrade the beam quality. Thermal lensing and thermally induced wavefront deformation are the main causes of the beam quality deterioration. Here we investigate the performance of a zero thermal expansion (ZTE) solid-state laser gain material. In a proof-of-principle experiment, an ${a}$-cut rod ${\rm Nd}\!:\!{{\rm YAlO}_3}$ (Nd:YAP) perovskite crystal is chosen to be the gain medium for ZTE around 180 K. The laser performance spanning the temperature range from 80 to 290 K is studied. The maximum output power and minimum threshold pump power were obtained at a temperature of 180 K. Moreover, the measured thermal focal power and peak-to-valley value of the wavefront distortion also reach a minimum at this temperature, an additional benefit from the crystal's ZTE coefficient. We envisage that these results will open a new route towards the development of high-power and high-beam-quality lasers through the use of ZTE gain materials.

A novel and thermally stable aluminum phosphate Li 6 Na 3 Sr 14 Al 11 P 22 O 90 (1) has been achieved by using a solid-state molten method, which contains an oxo-centered trinuclear cluster and an anti-Lowenstein's rule Al-O-Al linkage and is constructed from two types of (3,6)-connected kgd layers [Al(Al 3 O)(PO 4 ) 7 ] 25- and [Al(PO 4 ) 2 ] 3- . The good optical transparency in the whole UV range and excellent thermal stability make the title compound a potential optical window material.

The first lead tellurate-nitrate nonlinear-optical (NLO) crystal, Pb 9 Te 2 O 13 (OH)(NO 3 ) 3 , featuring a 3D anionic diamondlike toplogical structural motif formulated as [Pb 9 O 13 ] 8- constructed by unique nonanuclear basket-shaped Pb@Pb 8 O 14 clusters has been hydrothermally achieved, in which the Pb@Pb 8 O 14 cluster shows a core-shell structure with one PbO 10 polyhedron enclosed by eight PbO x (x = 3 and 4) polyhedera via edge and face sharing. The hexavalent Te in TeO 5 (OH) octahedra is linked to a [Pb 9 O 13 ] 8- cluster to form a rare [Pb 9 Te 2 O 13 (OH)] 3+ cationic framework. The compound demonstrates a powder second-harmonic-generation (SHG) response of about 1.2 times that of KH 2 PO 4 (KDP) as well as a wide transparency range. Calculations on the local dipole moment and SHG coefficient reveal that the net polarization is zero because of a Kleinman-forbidden point group. Further analysis shows that the SHG response results from structure-induced variations by thermal vibrations of the lattice rather than the intrinsic dipole moment, which offers another insight on the design of new NLO materials.

We conducted a greenhouse experiment to test how clonal integration affected the growth responses of Spartina anglica to light intensity heterogeneity in light availability and whether such effects depended on contrast light intensity. The experiment had three homogeneous treatments and two heterogeneous treatments. In the homogeneous treatments, both ramets of a connected ramet pair were unshaded (high light intensity), moderately shaded (medium light intensity, 70% of the high light intensity) and deeply shaded (low light intensity, 30% of the high light intensity). In the heterogeneous treatments, one ramet of a pair was unshaded, but its connected ramet was either moderately shaded (low light intensity contrast) or deeply shaded (high light intensity contrast). In the homogeneous treatments, biomass of S. anglica was significantly higher in the high light intensity treatment than in the medium and low light intensity treatments. Number of leaves, root length, and total biomass were significantly higher in the shaded ramet in the heterogeneous treatment with low light intensity contrast than in the ramet in the homogeneous treatment with medium light intensity. Final size and mass were not significantly different between the unshaded ramet in the heterogeneous treatment with low light intensity contrast and the ramets in the homogeneous high light intensity treatment. These results suggested that clonal integration benefitted a shaded ramet with little cost to an unshaded ramet when contrast in light intensity was low. However, effects of clonal integration were not significant when contrast was high. It therefore appeared that effects of clonal integration on the growth of S. anglica did not increase with increasing light intensity contrast. In natural habitats, clonal integration might improve growth of S. anglica when its ramets are moderately shaded by other plants but not when they are deeply shaded.