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Two supramolecular compounds based on Keggin polyoxotungstates, (4,4′-H2bpy){[Cu(4,4′-bpy)]2[SiW12O40]} (1) and (4,4′-H2bpy)2[SiW12O40]·2H2O (2) have been synthesized and characterized by elemental analyses, IR, UV, XPS spectra, TG analyses, and single crystal X-ray diffraction analyses. Compound1exhibits an infinite 1-D ladder like structure, which is further interconnected into a 3-D supramolecular frameworkviahydrogen bonding interactions. Compound2contains 4,4′-bipyridine (4,4′-bpy), pseudo-Keggin polyoxoanions [SiW12O40]4−, and water molecules. Polyoxoanions together with water molecules in2construct a 3-D inorganic supramolecular network through O···O and O···Ow(1) interactions. The electrochemical behaviors and photocatalytic properties of1and2have been investigated. [ABSTRACT FROM PUBLISHER]

Significant variations in leaf colours, pigment contents, and main taste compounds in young shoots from albino tea plants (Camellia sinensis) influence tea flavour. However, the seasonal metabolic pattern and molecular regulatory mechanism of these metabolites remain largely elusive. Herein, we conducted morphological, biochemical, metabolomic and transcriptomic analyses between an albino tea cultivar 'Zhonghuang 3' ('ZH3') and a green strain 'Tai cha 15' ('TC15') at four‐time points (April 12, May 31, July 14, and August 17) to elucidate dynamic changes in these compounds and predict the relationships among transcription factors (TFs), target genes (TGs), and metabolite abundance. Generally, leaf colours and pigment contents were significantly lighter and lower, respectively, in 'ZH3' than in 'TC15' from spring to summer, but were subsequently similar. Compared to 'TC15', 'ZH3' had a lower and broader phenol/ammonia ratio as well as stable caffeine content and showed more significantly different metabolites and differentially expressed genes. The relationship between pigments, main taste compounds, and their biosynthetic genes, as well as TFs and their TGs, had genetic specificity. These results suggested that the biosynthesis of these compounds was probably both season‐ and variety‐dependent. In total, 12 models of the TF‐TG‐metabolite regulatory network were proposed to uncover the biosynthetic and regulatory mechanisms of these metabolites in tea plants. A high correlation was observed between some structural genes and TFs with the accumulation of these metabolites. These findings provide novel insights into the regulatory mechanisms underlying accumulation of pigments and main taste compounds in tea plants. [ABSTRACT FROM AUTHOR]

Abstract: A new compound, [Cu(en)2][Cu(en)2(H2O)]2[SiMo8V6O42][Cu(en)2]·1.5H2O (1) (en=ethylenediamine), has been hydrothermally synthesized and characterized by elemental analysis, IR, ESR spectrum, TG analysis and single-crystal X-ray diffraction analysis. Compound 1 represents a 1-D zigzag chain-like structure constructed from dimeric units of bi-capped polyoxoanions {[Cu(en)2]2[Cu(en)2(H2O)]2[SiMo8V6O42]2[Cu(en)2]}6− and transition metal coordination fragment [Cu(en)2]2+. The adjacent chains are further interconnected into a 3-D supramolecular structure via hydrogen bonds. The magnetic susceptibility of 1 demonstrated the presence of antiferromagnetic interactions. [Copyright &y& Elsevier]

Two supramolecular compounds based on Keggin-type polyoxometalates (POMs), (4,4′-H2bpy)(4,4′-Hbpy)[PMo12O40] (1) and (4,4′-H2bpy)(4,4′-Hbpy)2[SiW12O40] · 4H2O (2), have been synthesized hydrothermally and characterized by elemental analyses, IR, UV-Vis, XPS spectra, thermogravimetric analyses, and single-crystal X-ray diffraction analyses. The two compounds consist of 4,4′-bipyridine (4,4′-bpy) ligands and different Keggin-type POMs which are [PMo12O40]3−for1and [SiW12O40]4−for2. There are hydrogen-bonding interactions between the POMs, 4,4′-bipyridine, and/or water in1and2. In addition,2contains an uncommon (H2O)2water cluster. [ABSTRACT FROM PUBLISHER]

Abstract: A new 3D supramolecular framework, (1) (en=ethylenediamine), has been hydrothermally synthesized and characterized by elemental analysis, IR, XPS, TG and single crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group C2/c, a =12.735(3), b =26.976(5), c =21.171(4)Å, β =92.64(3)°, V =7265(2)Å3, and Z =4. Complex 1 exhibits an interesting three-dimensional supramolecular framework assembled by sinusoidal-like arrangement of two-dimensional coordination polymer layers and crystal water molecules. The magnetic behavior of 1 has also been studied. [Copyright &y& Elsevier]

Abstract: Three compounds based on polyoxometalate building blocks, [Cu(en)2]{[Cu(en)2]2[MoVI 5MoV 3VIV 8O40(PO4)]}·4H2O (1), [Co(en)2]{[Co(en)2]2[HMoVI 4MoV 4VIV 8O40(PO4)]}·5H2O (2) and [Ni(en)2]{[Ni(en)2]2[MoVI 5MoV 3VIV 8O40(VO4)]}·2H2O (3) (en=ethylenediamine), have been synthesized and characterized by elemental analysis, IR, XPS, XRD, TGA and single-crystal X-ray diffraction analysis. The result of structure determination shows that isomorphic compounds 1, 2 and 3 feature a one-dimensional chain built from the reduced tetra-capped pseudo-Keggin polyoxoanion, which is further interconnected by [M(en)2]2+ (M=Cu, Co and Ni) groups via the terminal oxygen atoms of polyoxoanions. The crystal data for these compounds are the following: 1, monoclinic, space group C2/c, a =26.702(3)Å, b =13.4539(14)Å, c =19.5987(19)Å, β =108.650(2)°, V =6671.0(12)Å3, Z =4; 2, monoclinic, space group C2/c, a =26.244(3)Å, b =13.5070(17)Å, c =19.581(3)Å, β =106.881(2)°, V =6641.8(15)Å3, Z =4; 3, monoclinic, space group C2/c, a =26.2789(15)Å, b =13.5408(6)Å, c =19.6312(9)Å, β =106.2590(10)°, V =6706.1(6)Å3, Z =4. Variable-temperature magnetic susceptibility measurements of compounds 1 and 3 reveal the feature of antiferromagnetic exchange in these compounds. [Copyright &y& Elsevier]

Abstract: Two new heteropoly tungstovanadate derivatives, [Fe(phen)3]2[W10.5V4.5O42]·3H2O (1) and [Fe(phen)3]2[W10V5O42].6H2O (2) (phen=1,10′-phenanthroline), have been synthesized under hydrothermal conditions by using different starting materials, and characterized by elemental analysis, IR, ESR, XPS, TGA and single-crystal X-ray diffraction analysis. Crystal data for compound 1: C72H54Fe2N12O45V4.5W10.5, monoclinic, space group C2/c, , , , (8)°, (5) Å3, ; for compound 2, C72H60Fe2N12O48V5W10, monoclinic, space group C2/c, (6) Å, , (5) Å, (3)°, (4) Å3, . The crystal structure analysis reveals that both polyoxoanions are decorated with the [Fe(phen)3]2+ cations, and that they have analogous structure to each other with slightly different packing modes of the polyoxoanions, [Fe(phen)3]2+ cations and water molecules. They are further linked to form two-dimensional (2D) supramolecular networks through extensive hydrogen bonding. [Copyright &y& Elsevier]

The novel polyoxometalate [Cu(en)2(H2O)]{[Cu0.5(en)]3 [VVWVI6.5WV3V IV4.5O42Cu(en) 2]}·3.5H2O is hydrothermally synthesized from a mixture of Na2WO4, V2O5, CuSO4, (COOH)2 (molar ratio of 2:1:1:2), en, and H2O (autoclave, pH 7, 180 °C, 3 d, 60% yield). [ABSTRACT FROM AUTHOR]

Abstract: Material and definition of dome-shaped ceramic port cover contour is presented. Two types of ceramic port covers with equal thickness and variable thickness structures are proposed. A group of cold-flow tests was carried out on a reusable dual pulse motor in which the performances of different port covers including sealing, first-pulse pressure bearing and second-pulse broken pressure were experimentally studied. A solid dual pulse motor for hot-firing test was designed, manufactured and statically tested. The feasibility of proposed bulkhead with ceramic port cover employed on actual solid dual pulse motor was proved. It is found that dome-shaped port cover made from machinable glass ceramic withstands a high pressure on its convex side, but is prone to fragmentation while imposing a reasonably low pressure on its concave side. The peripherally thickened port cover that is more robust in machining and assembly process is recommended. Grooves milled on the port cover induce fragmentation and are helpful to produce regular broken aperture shape. The bulkhead assembly consists of retaining ring, port cover and supporting ring can well fulfill the requirements of port cover in fixing, preloading and sealing. The broken fragments are less likely to damage the insulation structures of the combustion chamber and the nozzle unit which had been validated in the test. [Copyright &y& Elsevier]

Abstract: Two new polyoxometalates (1) and (2) (en=ethylenediamine, phen=1,10-phenanthroline) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR, EPR, XPS, elemental analysis and thermogravimetry. Their structures exhibit interesting 3D supramolecular networks, and contain new bicapped (pseudo-) Keggin-type tungsten–vanadium cluster and the template transition-metal complexes (TMCs) being generated in situ under mild hydrothermal conditions. Interestingly, compound 1 contains four different kinds of nickel complex countercations. [Copyright &y& Elsevier]

Abstract: A novel polyoxometalate [Cu(phen)2]3{PW4 VIW5 VV3 IVO40(VIVO)3[Cu(en)2]}⋅4H2O 1 (en=ethylenediamine, phen=1,10-phenanthroline) has been synthesized hydrothermally and characterized by elemental analysis, IR, XPS, TG, EPR and single-crystal X-ray diffraction analysis. The crystal structure analysis shows that compound 1 contains a novel highly reduced tri-capped and mono-supported pseudo-Keggin-type heteropolyanion, {PW4 VIW5 VV3 IVO40(VIVO)3[Cu(en)2]}6−, three [Cu(phen)2]2+ cations and four lattice water molecules. They are further linked to form three-dimensional supramolecular networks through extensive hydrogen bonding and π–π stacking interactions. Interestingly, the water dimer and terminal oxygen of the cluster polyanion constitute a beautiful supramolecular helix chain. The heteropolyanion is the first example of tri-capped and mono-supported pseudo-Keggin-type tungstovanadophosphate and the pH value is crucial for obtaining compound 1 in synthetic procedure. [Copyright &y& Elsevier]

Abstract: A novel polyoxometalate (1) has been synthesized in the system of Sb2O3-(NH4)6Mo7O24 ·4H2O-H3PO4-en-H2O under hydrothermal conditions and characterized by IR, TGA, elemental analyses, single crystal X-ray diffraction and XPS. Interestingly, compound 1 displays three-dimensional network consisting of one-dimensional sinusoidal chain [(Hen)2(H2O)2]2+ and two-dimensional layer formed by . The structure unit is the first example of bicapped by antimony α-Keggin structure. [Copyright &y& Elsevier]

Abstract In the present research, we produced porous silicon carbide (SiC) scaffolds with lamellar and uniformly distributed structures by unidirectional and quick freeze casting, respectively. Subsequently, we prepared the ZL205A/SiC composites with lamellar and uniformly distributed structures by infiltrating a molten ZL205A alloy into the porous SiC scaffolds. The influence of freezing speed on the damage-tolerance behavior and the toughening mechanism of the resultant composites were investigated. We found that because of multiple toughening mechanisms, the layered composites exhibited much higher strength and toughness as compared with the uniformly distributed composites. The lamellar composites manifested superior specific modulus and a unique combination of specific strength and toughness, which was comparable to those of titanium and magnesium alloys. We also observed that the thicknesses of alloy layers and SiC lamellae of the composites reduced with decreasing cooling temperature in freeze casting. Furthermore, the refinement of lamellae size at higher freezing speeds caused a decrease in the damage-tolerance ability of the composites because of weak toughening effect. Graphical Abstract Unlabelled Image Highlights • The ZL205A/SiC composites with lamellar and uniformly distributed structures were prepared. • The microstructure of the composite was adjusted by manipulating the freezing rate of the SiC slurry. • Lamellar composites exhibited much higher strength and toughness as compared with the uniformly distributed composites. • The refinement of lamellae size caused a decrease in damage-tolerance ability of the composites. [ABSTRACT FROM AUTHOR]

Novel bio-inspired ZL205A/SiC composites with a lamellar-interpenetrated structure were successfully fabricated via gas-pressure infiltration of a commercial ZL205A alloy into freeze-cast porous SiC scaffolds. The influences of initial ceramic content (20, 30 and 40 vol%) on the microstructure and damage-tolerance behavior of the resultant composites as well as their toughening mechanism were investigated. With an increase in the ceramic content in the composite, the flexural strength and fracture toughness in the longitudinal direction gradually decreased; whereas, in the transverse direction they showed a first increase and then decrease but their elastic modulus increased. The composites displayed significant damage-tolerance anisotropy, with higher strength and toughness in the longitudinal direction (parallel to the lamellae) than that in the transverse direction (perpendicular to the lamellae). In the longitudinal bending, the ZL205A/20 vol%SiC composite exhibited the maximum flexural strength (760 MPa) and the largest fracture toughness (33.0 MPa m 1/2 ). The excellent damage tolerance of the composites was attributed to multiple toughening mechanisms such as plastic deformation in the matrix alloy, crack blunting, deflection and branching, and uncracked-ligament bridging of the ductile alloy layers. However, in the transverse bending, the crack propagated along the ceramic layer in the composites and thus greatly weakened their damage-tolerance capability. [ABSTRACT FROM AUTHOR]

Abstract: Three new supramolecular compounds based on triethylenediamine and different polyoxometalates [WVI 3VV 3O19H]{[Cu(HDABCO)]2(H2O)} (1), [P2MoVI 18O62][HDABCO]2[H2DABCO]2·12H2O (2) and [MoVI 7.5WVI 0.5O27][Cu(HDABCO)]2·2H3O·2H2O (3) (DABCO=triethylenediamine) have been synthesized hydrothermally and characterized by IR, TG, XPS and X-ray diffraction analyses. Crystal structure analyses reveal that compound 1 exhibits a face-centered cubic packing motif, compound 2 displays a supramolecular structure constructed form the “chains” arranged hexagonally, compound 3 contains [Mo7.5W0.5O27]∞ chain decorated by [Cu(HDABCO)]2+ cations, which was then packed into a layer structure. These results show that the same organonitrogen combining with the different POMs will yield different supramolecular networks. [ABSTRACT FROM AUTHOR]

Abstract: Two novel polyoxometalate derivatives, {X IVWVI 10WV 2O40[Cu(en)2(H2O)]3} [X=V (1), Si (2); en=ethylenediamine], have been hydrothermally synthesized and characterized by elemental analyses, IR, UV–Vis, XPS, EPR, TG and single crystal X-ray diffraction analyses. They represent the first classical Keggin polyoxoanion supported by three transition metal complex moieties, which further act as the neutral molecular unit for the construction of the interesting three-dimensional supramolecular frameworks. The magnetic properties of 1 have also been studied in the temperature range of 4–300K, and its magnetic susceptibility obeys the Curie–Weiss law, showing antiferromagnetic coupling. [Copyright &y& Elsevier]

Abstract: Two new coordination complexes, [Ni2(Him)12 ·(bta)·8H2O] 1 and [Cd2(Him)4(bta)] 2, (H4bta=1,2,4,5-benzenetetracarboxylic acid, Him=imidazole) were prepared under hydrothermal conditions and their structures were determined by single-crystal X-ray diffraction. X-ray diffraction reveals that complex 1, consisting of two crystallographically independent [Ni(Him)6]2+ fragments, an uncoordinated bta4− anion and eight lattice water molecules, displays an interesting 3D supramolecular network constructed by cationic layers (layer A) and anionic layers (layer B) with ABAB sequence through hydrogen bonding interactions. In complex 2, each bta ligand links four metal ions to form a one dimensional (1D) double chain. The 1D double metal chains are assembled into a 3D supramolecular network through NO hydrogen bonding and Cπ interactions. Complex 2 shows strong blue fluorescence at room temperature. [Copyright &y& Elsevier]

Abstract: A novel polyoxometalate [Cu(en)2(H2O)]2[Cu(en)2]2 [AsW9V7O44]·2H2O (1) has been hydrothermally synthesized and characterized by elemental analysis, IR spectrum, XPS spectrum and single crystal X-ray diffraction analysis. It is the first example of two-dimensional layer structure constructed from four vanadium-capped pseudo-Keggin tungstates. The study of the magnetic susceptibility of 1 demonstrates the presence of ferromagnetic interactions. [Copyright &y& Elsevier]

Abstract: A novel coordination polymer, {[Cu(ip)(Him)2(H2O)]·3H2O} (1), (ip=isophthalate, Him=imidazole) was prepared under hydrothermal conditions and its structure is determined by single-crystal X-ray diffraction. X-ray structural analysis reveals that 1D zigzag metal-organic framework was connected to form a 3D metal-organic framework by a novel infinite 1D water chain constructed by five- and six-membered rings through edge-sharing. These water chains behave as glue to stabilize the 3D network. Upon removal of the water molecules by heating, the 3D structure breaks down. Thermogravimetric analysis, infrared, X-ray powder diffraction studies, elemental analysis and magnetic analysis were performed to characterize this compound. [Copyright &y& Elsevier]

A novel cerium–adipate coordination polymer [Ce2(ad)3(H2O)2]n(1) has been hydrothermally synthesized and structurally characterized, which possesses three-dimensional network structure constructed from infinite chains of edge-sharing CeO8(H2O) polyhedron and long carbon chains. Each cerium cation binds to nine oxygen atoms belonging to six adipates and one water molecule, the adjacent cerium atoms are linked together through chelating-bridging and bidentate bridging carboxylates to form infinite polyhedron chains along [1 0 0] direction. The starlike distribution of six μ4-adipates around the central cerium generates a complicated network, which is thermally stable without any collapse even though no any guest molecules reside in the large channels. [Copyright &y& Elsevier]

Objective To design simulated pulmonary air embolism demonstration model, so as to solve the problem of pathological anatomy of pulmonary air embolism in experiment teaching. Methods According to the principle of the disturbance of local blood circulation and air embolism, we designed a pulmonary air embolism model. We took 223 school nursing students as the object of this study, and randomly divided them into 2 groups: animal experiment teaching group and model control group, then we compared the teaching effect between the two groups. Result The test scores of students in the animal experiment teaching group were higher than control group (P < 0.05). Conclusion The use of simulated pulmonary air embolism demonstration model teaching can improve the students' experimental test scores, and can be repeatedly used, stimulate students' study interest, reduce the cost of teaching, and improve the teaching quality. [ABSTRACT FROM AUTHOR]