1-Amino­pyridinium triiodidoplumbate(II)

The title complex, (C5H7N2)[PbI3], consists of a 1-amino­pyridinium cation, disordered about a mirror plane, and a [PbI3]− anion. The Pb2+ ion (site symmetry ) is surrounded by six I atoms in a slightly distorted octa­hedral coordination. The PbI6 octa­hedra share faces, building up ∞ 1[PbI6/2] chains running along [010]. The cations are situated between the chains. Coulombic attractions and van der Waals inter­actions between the inorganic and organic components are mainly responsible for the cohesion of the structure

3,3′-Dimethyl-1,1′-(propane-1,3-di­yl)diimidazol-1-ium bis­(1,2-dicyano­ethene-1,2-dithiol­ato-κ2 S,S′)nickelate(II)

In the title compound, (C11H18N4)[Ni(C4N2S2)2], the asymmetric contains one half-complex, with the cation placed on a twofold axis and the anion located on an inversion center. The NiII ion in the anion is coordinated by four S atoms of two maleonitrile­dithiol­ate ligands, and exhibits the expected square-planar coordination geometry

Bis(4-dimethyl­amino-1-ethyl­pyridinium) bis­(1,2-dicyano­ethene-1,2-dithiol­ato-κ2 S,S′)nickelate(II)

The asymmetric unit of the title complex, (C9H15N2)2[Ni(C4N2S2)2], comprises one 4-dimethyl­amino-1-ethyl­pyri­din­ium cation and one half of a [Ni(mnt)2]2− (mnt2− = maleo­nitrile­dithiol­ate) anion; the complete anion is generated by the application of a centre of inversion. The NiII ion is coordinated by four S atoms of two mnt2− ligands and exhibits a square-planar coordination geometry

3-Butyl-1-methyl-1H-imidazol-3-ium bis­(1,2-dicyano­ethene-1,2-dithiol­ato-κ2 S,S′)nickel(III)

In the title compound, (C8H15N2)[Ni(C4N2S2)2], the NiIII atom is coordinated by four S atoms of two maleonitrile­dithiol­ate ligands and exhibits a distorted square-planar geometry. In the crystal, the cations and anions are connected alternately by weak inter­molecular C—H⋯N hydrogen bonds, forming a zigzag chain along [201]

Control water waves by metagratings

Metasurfaces and metagratings offers new platforms for electromagnetic wave control with significant responses. However, metasurfaces based on abrupt phase change and resonant structures suffer from the drawback of high loss and face challenges when applied in water waves. Therefore, the application of metasurfaces in water wave control is not ideal due to the limitations associated with high loss and other challenges. We have discovered that non-resonant metagratings exhibit promising effects in water wave control. Leveraging the similarity between bridges and metagratings, we have successfully developed a water wave metagrating model inspired by the Luoyang Bridge in ancient China. We conducted theoretical calculations and simulations on the metagrating and derived the equivalent anisotropic model of the metagrating. This model provides evidence that the metagrating has the capability to control water waves and achieve unidirectional surface water wave. The accuracy of our theory is strongly supported by the clear observation of the unidirectional propagation phenomenon during simulation and experiments conducted using a reduced version of the metagrating. It is the first time that the unidirectional propagation of water waves has been seen in water wave metagrating experiment. Above all, we realize the water wave metagrating experiment for the first time. By combining complex gratings with real bridges, we explore the physics embedded in the ancient building-Luoyang Bridge, which are of great significance for the water wave metagrating design, as well as the development and preservation of ancient bridges.Comment: 25 pages, 13 figure

Low-carbon developments in Northeast China: Evidence from cities

Cities are a major source of energy use and greenhouse gases emissions, as well as being at the core of the climate change mitigation. With the Revitalizing Old Industrial Base of Northeast China strategy, Northeast China has been a typical developing region with rapid industrialization and urbanization accompanied by substantial energy consumption and carbon emissions. Therefore, northeastern Chinese cities should play an important role in regional low-carbon developments. This study presents several improvements to previous method to improve the accuracy of the results. Using the modified method, for the first time, we compile carbon emission inventories for 30 cities in Northeast China based on fossil fuel combustion and industrial processes. The results indicate that Anshan emitted the most carbon emissions annually, followed by Benxi and the vice-provincial cities (including Changchun, Shenyang, Dalian and Harbin). In 2012, the total carbon emissions of the 30 cities amounted to 973.95 million tonnes, accounting for 9.71% and 2.75% of national and global carbon emissions, respectively. Most of the CO2 emissions of these cities were from the ‘nonmetal and metal industry’ and ‘energy production and supply’. Raw coal was the primary source of carbon emissions in Northeast China, and industrial processes also played a significant role in determining the carbon emissions. Additionally, both the average per capita carbon emissions and carbon emission intensity in the 30 cities were higher than the national levels. According to the differences in carbon emissions characteristics, we present several policy recommendations for carbon mitigation for northeastern Chinese cities. This study provides consistent and comparable spatial-temporal city-level emission database for further research on relationships between economic development and environmental protection in Northeast China. Simultaneously, this study provides practical reference values for other developing regions throughout the world to create low-carbon road maps