Germanosilicates, an important family of zeolites with increasing number of members and attractive porosities, but containing a large quantity of unstable Ge atoms in the framework, meet with great obstacles in terms of limited thermal and hydrothermal stability when it comes to practical use. A facile stabilization method thus has been developed to substitute isomorphously Ge atoms for Si atoms, giving rise to ultrastable siliceous analogues of the pristine germanosilicates.

In this paper a new parameter for hypergraphs called hypergraph infection is defined. This concept generalizes zero forcing in graphs to hypergraphs. The exact value of the infection number of complete and complete bipartite hypergraphs is determined. A formula for the infection number for interval hypergraphs and several families of cyclic hypergraphs is given. The value of the infection number for a hypergraph whose edges form a symmetric t-design is given, and bounds are determined for a hypergraph whose edges are a t-design. Finally, the infection number for several hypergraph products and line graphs are considered.

Interlayer-expanded zeolite, IEZ-NSI, has been post-synthesized from a two-dimensional (2D) layered precursor Nu-6(1) (Si/Al ratio = 30 − ∞) by intercalating with diethoxydimethylsilane in hydrochloric acid solution. Ethanol was demonstrated to be a suitable solvent for inducing an effective interlayer pillaring with monomeric silane. IEZ-NSI was revealed to possess a 3D crystalline structure composed of 10-membered ring (MR) channels by using Rietveld crystal structure refinement of the PXRD pattern of IEZ-Nu-6(1)-H (Si/Al = ∞). The 10-MR pores in IEZ-NSI were constructed through the linkages between the pillaring Si atoms and the NSI layers. IEZ-Nu-6(1)-H(Si/Al = ∞) crystallizes in space group P121/a1 (No. 14) with a = 22.9372(4) Å, b = 5.0205(5) Å, c = 13.8209(1) Å, and β = 103.294(22)°. IEZ-NSI with more accessible channels gave a higher catalytic activity in the esterification of acetic acid with ethanol in comparison to Nu-6(2).

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