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Solvothermal subcomponent self-assembly of 2-hydroxy-3-(pyridin-4-yl)benzaldehyde, chiral diaminocyclohexane, and Zn(ii) ions offered a pair of two-dimensional chiral metal–organic frameworks, which display circularly polarised luminescence.

When compared to industrially stable zeolites, the instability of metal-organic frameworks (MOFs) has been denounced by researchers. Boosting the stability of existing MOFs is highly important for practical applications. In this report, we develop a new strategy to prepare MOFs/poly(tetrafluoroethylene) (PTFE) composites, which can highly improve the chemical, pressure, and photostabilities of zeolitic imidazolate framework (ZIF)-8. Composite materials were prepared by a physical blending of ZIF-8 and PTFE emulsion with different ratios and annealing at 370 °C. Transmission electron microscopy (TEM) studies reveal that the nanoparticles of ZIF-8 are coated by PTFE to form the composite materials. Upon mixing with 20 or 50 wt % PTFE, the ZIF-8/PTFE materials show a superhydrophobic property with water contact angles of around 156°. Pristine ZIF-8 is not stable in water with stirring under acidic, basic, and irradiation conditions, while the ZIF-8/PTFE materials are stable under the same conditions. The ZIF-8/PTFE materials can also maintain their crystalline structure after being compressed with a 10 MPa pressure, while pristine ZIF-8 changes to an amorphous solid after the same pressure treatment. Using water as a solvent, ZIF-8/PTFE can be used as a highly efficient and recyclable catalyst for Knoevenagel reaction at room temperature. The successful preparation of stable ZIF-8/PTFE composite materials provides a useful method to enhance the chemical, pressure, and photostabilities of MOFs.

In this paper, a novel numerical method called field-enriched finite element method is proposed to investigate stress intensity factor, initiation angle and propagation path of interface crack. The features of the field-enriched finite element method are: (1) re-meshing is avoided during the process of crack propagation; (2) the physical position of crack can be located and the influence of crack on the physical field of whole model can be described by enriching the field variables; (3) the fracture criterion can be flexibly embedded in the field-enriched finite element method to predict the initiation angle and propagation path of interface crack. Some numerical examples are used to verify the effectiveness and accuracy of the field-enriched finite element method. The numerical results obtained by the field-enriched finite element method can be consistent with the theoretical solution, experimental observation and other numerical results obtained by traditional finite element method or extended finite element method. Therefore, the field-enriched finite element method can provide a new scheme to deal with the interface crack fracture problems.

Metal-organic cages, a class of supramolecular containers constructed by the self-assembly of metal ions and organic ligands, show great promise as catalytic agents. In this work, we designed and synthesized a series of rhombic dodecahedral Ni-Cu heterometal imidazolate cages (Ni8Cu6L24) that can act as highly active photo-Fenton-like catalysts. These cages possess a high ability to generate hydroxyl radicals (•OH) under visible light in the presence of H2O2, which can rapidly degrade organic pollutants (e.g., rhodamine B, methylene blue, and methyl orange) into CO2 and H2O. Besides, they are robust catalysts, with high catalytic activity and reusability under conditions in high H2O2 concentration, providing potentially advanced materials for degrading persistent organic pollutants.

In this paper, smoothed bond-based peridynamics (SBBPD) is proposed to simulate the large deformation. The governing equation of smoothed bond-based PD is obtained by incorporating the observed changes in the density field and long-range force reaction in Eulerian form. The Hencky stretch is introduced into smoothed bond-based PD to calculate the true strain because of the change in density (volume). The proposed method can achieve a more accurate result in solid mechanics compared with SPH and can well handle extremely large deformation problems compared with traditional bond-based PD. Numerical experiments are launched to test these modifies of smoothed bond-based PD method in solid mechanics.

Water oxidation to molecular oxygen is indispensable but a challenge for splitting H2O. In this work, a series of Co-based metal-organic cages (MOCs) for photoinduced water oxidation were prepared. MOC-1 with both bis(μ-oxo) bridged dicobalt and Co-O (O from H2O) displays catalytic activity with an initial oxygen evolution rate of 80.4 mmol/g/h and a TOF of 7.49 × 10-3 s-1 in 10 min. In contrast, MOC-2 containing only Co-O (O from H2O) in the structure results in a lower oxygen evolution rate (40.8 mmol/g/h, 4.78 × 10-3 s-1), while the amount of oxygen evolved from the solution of MOC-4 without both active sites is undetectable. Isotope experiments with or without H218O as the reactant successfully demonstrate that the molecular oxygen was produced from water oxidation. Photophysical and electrochemical studies reveal that photoinduced water oxidation initializes via electron transfer from the excited [Ru(bpy)3]2+* to Na2S2O8, and then, the cobalt active sites further donate electrons to the oxidized [Ru(bpy)3]3+ to drive water oxidation. This proof-of-concept study indicates that MOCs can work as potential efficient catalysts for photoinduced water oxidation.

To analyze the genotype characteristics of α- and β-thalassemia and the diagnostic value of hematological indexes in pregnant women in Xindu District of Chengdu.The blood routine parameters(MCV)80 fl and (or) (MCH)27 pg and hemoglobin electrophoresis were used to screen the pregnant women, PCR-reverse dot blot hybridization(PCR-RDB) technique was used to detect the common α- and β-thalassemia gene types in the primary screening positive population. The husbands of the diagnosed pregnant women were recalled for gene testing, and the highly suspected patients were checked by gene sequencing.Among the 7 049 pregnant women, 1 740(24.68%) cases were positive for primary screening. 180 patients were diagnosed as thalassemia gene positive, among them, 94 cases (52.22%) of α-thalassemia were detected and six genotypes were found, in which --The most common genotypes of α- and β-thalassemia in pregnant women in Xindu District of Chengdu were --成都市新都区孕妇地中海贫血基因检测结果及血液学指标应用价值.分析成都市新都区孕妇α、β地中海贫血的基因型特点及各血液学指标的诊断价值.采用血常规参数（MCV）80 fl和（或）（MCH）27 pg及血红蛋白电泳对孕妇进行初筛，初筛阳性者采用PCR-反向斑点杂交检测技术进行常见α、β地中海贫血基因检测，对于确诊为地贫孕妇，召回其丈夫直接进行地贫基因检测，对高度疑似患者进行基因测序复核结果.7 049例孕妇中，初筛阳性1 740例（24.68%）。地贫基因确诊阳性180例，其中α地中海贫血94例（52.22%），共检出6种基因型，基因型--成都市新都区孕妇α、β地中海贫血基因类型主要以

A unique metal-organic framework (MOF) with tetrazole-padded helical channels has been successfully synthesized in one pot from iron(II) trifluoromethanesulfonate, 4-formylimidazole, hydrazine, and sodium azide under solvothermal conditions and features a rare unh topology and porous structure for gas adsorption. Transformations of condensation, cycloaddition, and coordination occurred during the synthetic process, in which a 1,5-disubstituted tetrazole ligand was formed in situ.

As a creation platform for multifunctional materials, crystalline metal–organic frameworks (MOFs) can integrate different chromophores through reticular chemistry to adjust their spatial arrangement and intermolecular interaction, in turn achieving the purpose of improving the nature of optoelectronic properties. Herein, a stepwise reticular synthesis approach is successfully used to construct a multicomponent MOF, in which the well-known bis-terpyridyl ruthenium chromophore is orderly arranged into the skeleton of the material. Remarkably, this method promotes the excited state lifetime of the bis-terpyridyl ruthenium core, by two orders of magnitude (from 0.39 to 22.09 ns), to the extent that it can produce singlet oxygen under visible light irradiation at room temperature. Meanwhile, the obtained multicomponent MOF has been established to have considerable porosity for exposure of substrates to the catalytic sites, rendering it suitable for heterogeneous photocatalysis, including as a photooxidation detoxifier for sulfur mustard simulant. Moreover, DFT and TDDFT calculations reveal that the synergistic charge transfer among different components in the MOF may play a crucial role in improving the excited state properties of the bis-terpyridyl ruthenium motif.

A triangular prismatic metal-organic cage based on mixed valence copper ions has been designed and synthesized by using metallocycle panels and pillar ligands. The triangular prism will be quickly transformed to a 10-nuclear cage upon an external chemical stimulus, which features a bicapped square antiprism structure. This prismatic cage can act as a catalyst for oxidation of aromatic alcohols to their corresponding aromatic aldehydes with high yields at room temperature under O2 atmosphere.

Herein we report a discrete heterometallic Pd

Gas separation performances are usually degraded under humid conditions for many crystalline porous materials because of the lack of water stability and/or the competition of water vapor toward the interaction sites (e.g., open metal sites). Zeolitic imidazolate frameworks (ZIFs) are suitable candidates for practical applications in gas separation because of their excellent physical/chemical stabilities. However, the limitation of substituent positions in common ZIFs has prevented extensive pore engineering to improve their separation performance. In a type of gyroidal ZIFs with

SUMMARY Uniaxial compression tests with combined acousto-optical monitoring techniques are conducted on flawed granite specimens, with the aim of investigating the fracture-related acoustic emission (AE) event rate characteristics at the unstable cracking phase in flawed rocks. The interevent time (IET) function F(τ) is adopted to interpret the AE time-series from damage stress (σcd) to ultimate failure, and photographic data are used to evaluate unstable cracking behaviours in flawed granite. The results show that a high AE event rate is always registered but intermittently interrupted by macrofracturing at the unstable cracking phase. The reversed U-shaped curve relation between the AE event rate and the loading time is documented in unstable flawed granite for the first time. The acoustic quiescence has a mechanismic linkage and quantitative correlation with stress drop, and this synchronous acousto-mechanical behaviour is a typical result of the initiation, growth and coalescence of macrocracks initiated from the flaw tips. Moreover, the reactivation and intensification of fracture process zones (FPZs) by increasing loads are the dominant mechanism triggering unstable crack growth in flawed granite.

Polynuclear silver clusters are described that unexpectedly transform from cyclic trinuclear complexes (CTCs) upon reacting with σ-donating phenylacetylene, featuring a noria-like conformation. The introduction of foreign copper ions leads to isomorphic bimetallic Ag/Cu clusters, with a boost in the photoluminescence quantum yield relative to the original silver clusters.