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Government collaboration tasks are integral for grassroots governance and essential for government administration. Large-scale government collaboration tasks often involve multiple departments working together to solve complex tasks that require handling large amounts of data. However, existing offline processes make it difficult to manage complex collaboration scenarios and obtain timely execution results. We introduce the concept of a spatio-temporal task tree and propose a log-based incremental update method for updating statistical values in the tree structure to fulfill the need for real-time aggregation analysis of cross-temporal task execution situations. The spatio-temporal task tree fosters collaboration across various departments and organizational hierarchies to execute complex and large-scale tasks in government effectively. By flexible adaptations to different business models, this framework addresses the shortcomings of conventional systems in promoting inter-organizational collaboration. The log-based incremental update method for calculating statistical values within a tree structure allows for the updating of multi-dimensional data statistics in seconds. This approach effectively decreases computational expenses, enhances query efficiency, and improves real-time computation response. Results from experiments demonstrate the feasibility and high availability of the proposed approach, showcasing their potential to address the challenges associated with large-scale collaborative tasks in government affairs. [ABSTRACT FROM AUTHOR]

In the engineering of high stress area, the measures to control the stability of surrounding rock by reducing excavation footage and excavation speed are to adjust the unloading rate of surrounding rock caused by excavation. In this study, unloading creep tests of marble under high stress conditions were carried out to study the effect of unloading rate. Research results showed that the axial and lateral instantaneous strain and creep strain of the sample increased with the increase of unloading rate; the lateral creep characteristic of marble under unloading condition was stronger than that of axial creep characteristic, and it was more obvious with the increase of unloading rate; the failure of specimens under unloading creep condition was mainly caused by the rapid increase of lateral strain, and the brittleness of rock was increasing with the increase of unloading rate. The Burgers model was used to describe the creep curves of specimens, and the variation of the parameters with the unloading rate was analyzed. The fitting results showed that the instantaneous elastic modulus E1, E'1 and the viscosity coefficients η1, η'1 all decreased with the increase of the unloading rate, which can be described by linear relationship within the unloading rate range of this experiment. Compared with the time of whole creep tests, the time for each specimen to enter the steady-state creep was similar, it was considered that the effect of unloading rate on η2/E2 and η'2/E'2 can be ignored.

The manipulation on dual‐/multi‐band multiphoton pumped lasing in a single microcrystal is critically essential and technologically needed, which still faces difficulties such as the lack of effective approaches to integrate various multiphoton gain media while avoiding undesirable energy transfer processes. Herein, for the first time, the switchable dual‐band two‐photon pumped (TPP) lasing is realized by constructing composition‐graded metal–organic frameworks (MOFs) heterostructures. The epitaxial growth strategy is adopted for the development of heterostructures, which achieves the hierarchical encapsulation of different linear dye molecules along the 1D channels, thereby effectively restraining unnecessary intermolecular interactions. Strong position dependence of emission response in such deliberately designed heterostructures is observed, enabling a switchable dual‐band TPP polarized lasing through precise selection on excited positions. Furthermore, the excitation wavelength dependence of emission also endows such heterostructures with switchable optical behaviors (two‐photon fluorescence or lasing) via controlling the incident wavelength. The novel heterostructures for switchable dual‐band TPP lasing with uniquely position‐dependent and excitation wavelength‐dependent features open an avenue to develop controllable miniaturized lasers and make such MOFs based micro‐lasers promising for practical applications in future optoelectronic devices. [ABSTRACT FROM AUTHOR]

Halide perovskite nanocrystals (NCs) are a unique class of NCs with novel properties distinct from those of traditional semiconductor NCs. These exceptional properties of defect tolerance, large absorption coefficients, high brightness, and narrow emission linewidths stem from their atypical band structure. Their facile synthesis and broad colour tunability have attracted widespread interest for application in light emitting devices and lasers. One fledging niche area is the field of multiphoton excited emission where their giant nonlinear optical action cross-sections are highly favorable for imaging applications. This Frontier article examines the state-of-the-art in perovskite NCs for multiphoton applications from the materials science and physics perspectives that include their synthesis and nonlinear optical characterization. Opportunities and challenges of these exceptional NCs as potential fluorescent labels for multiphoton deep tissue microscopy are also highlighted. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have emerged as particularly exciting inorganic–organic hybrid porous materials which can be simply self-assembled from their corresponding inorganic metal ions/clusters with organic linkers. MOFs can combine the inherent physical and chemical properties of both inorganic and organic photonic units due to their inorganic–organic hybrid nature. Furthermore, the pores within MOFs can also be utilized to encapsulate a large number of guest species as photonic units. The vast combination possibilities, synergistic effects, as well as controllable and ordered arrangements of multiple photonic units (MPUs) have distinguished MOFs from other inorganic and organic photonic materials and enabled them to be a promising platform to realize novel photonic functional applications. In this review, we summarize the recent and important progress in the design and construction of photonic MOFs, as well as their various applications in luminescence sensing, white-light emission, photocatalysis, nonlinear optics, lasing devices, data storage, and biomedicine. In addition, we highlight the construction strategy and the synergistic effects of MOFs towards achieving high performance and novel photonic functions. Finally, we also outline the challenges in these fields and put forward the prospects and directions for future development. [ABSTRACT FROM AUTHOR]

Due to the periodically physical/chemical environment and high-efficient confinement effect of the metal-organic framework (MOF) only possessing 1D channels, the authors realize periodically and highly aligned dye molecule integration within the MOF hybrid material ZJU-68⊃DMASM. Such molecule integration can provide an opportunity to directly determine 4-[ p-(dimethylamino)styryl]-1-methylpyridinium (DMASM) molecules in the MOF channels by electron density mapping using X-ray diffraction data. Furthermore, combining the anisotropic emission property of such molecule integration and the perfect crystal morphology of ZJU-68 serving as the natural resonant cavity, the authors obtain a single-mode linearly polarized laser excited by light ranging from visible to near-infrared. [ABSTRACT FROM AUTHOR]

The first luminescent two-dimensional MOF nanosheets NTU-9-NS Ti2(HDOBDC)2(H2DOBDC) (H2DOBDC = 2,5-dihydroxyterephthalic acid) fabricated via top-down delamination have been realized for the highly sensitive sensing of Fe3+ with a fast response. The highly dispersive nature and highly accessible active sites on the surface of the 2D NTU-9-NS nanosheets enable them to have close contact with targeted metal ions, which leads to the highly sensitive sensing of Fe3+ ions, with a fast response time within seconds and the best detection limit performance of 0.45 μM among MOF materials. The fast response and highly sensitive Fe3+ sensing based on the NTU-9-NS nanosheets sensor material highlights the promise of the two-dimensional MOF nanosheet approach for luminescent sensing applications. This work contributes to the development of research on two-dimensional MOF nanosheets materials with targeted and specific recognition for the application of biological and environmental luminescent sensors. [ABSTRACT FROM AUTHOR]

Single crystal perovskite microplates are fundamentally and technologically very important to developing high‐order (n ≥ 3) multiphoton excitation. This study reports the preparation of high‐quality single crystal perovskite microplates through the controlled release of lead ions from the confined species within a metal–organic framework. The resulting free‐standing MAPbBr3 (MA = CH3NH3+) and CsPbBr3 single crystals of rectangular microplates exhibit excellent multiphoton excitation behaviors, as demonstrated in their five‐photon‐excited photoluminescence and three‐photon‐pumped stimulated emission with the threshold of 159 mJ cm−2, providing the promise of exploring high‐quality single crystal perovskite microplates for functional optoelectronic and photonics applications. [ABSTRACT FROM AUTHOR]

Organic lasers have become an important research and application target for the development of optoelectronics and future photonics due to their ease of preparation and miniaturization, low threshold, and wideband tunability, as well as large optical and nonlinear optical cross sections. Recently, the metal–organic framework (MOF) based organic microlasers have received increasing research attention because they not only achieve high gain concentrations while minimizing the common aggregation‐caused quenching effect of organic luminescence systems, but also can optimize and even control the output performance of the laser by manipulating the interaction between the framework and the gain molecules. In this review, the latest advances in MOF‐based organic lasers are explored and insights into future trends are given, providing useful guidance for the design and preparation of new‐type lasers. [ABSTRACT FROM AUTHOR]

Discoveries of novel functional materials have played very important roles to the development of science and technologies and thus to benefit our daily life. Among the diverse materials, metal-organic framework (MOF) materials are rapidly emerging as a unique type of porous and organic/inorganic hybrid materials which can be simply self-assembled from their corresponding inorganic metal ions/clusters with organic linkers, and can be straightforwardly characterized by various analytical methods. In terms of porosity, they are superior to other well-known porous materials such as zeolites and carbon materials; exhibiting extremely high porosity with surface area up to 7000 m(2)/g, tunable pore sizes, and metrics through the interplay of both organic and inorganic components with the pore sizes ranging from 3 to 100 Å, and lowest framework density down to 0.13 g/cm(3). Such unique features have enabled metal-organic frameworks to exhibit great potentials for a broad range of applications in gas storage, gas separations, enantioselective separations, heterogeneous catalysis, chemical sensing and drug delivery. On the other hand, metal-organic frameworks can be also considered as organic/inorganic self-assembled hybrid materials, we can take advantages of the physical and chemical properties of both organic and inorganic components to develop their functional optical, photonic, and magnetic materials. Furthermore, the pores within MOFs can also be utilized to encapsulate a large number of different species of diverse functions, so a variety of functional MOF/composite materials can be readily synthesized. In this Account, we describe our recent research progress on pore and function engineering to develop functional MOF materials. We have been able to tune and optimize pore spaces, immobilize specific functional groups, and introduce chiral pore environments to target MOF materials for methane storage, light hydrocarbon separations, enantioselective recognitions, carbon dioxide capture, and separations. The intrinsic optical and photonic properties of metal ions and organic ligands, and guest molecules and/or ions can be collaboratively assembled and/or encapsulated into their frameworks, so we have realized a series of novel MOF materials as ratiometric luminescent thermometers, O2 sensors, white-light-emitting materials, nonlinear optical materials, two-photon pumped lasing materials, and two-photon responsive materials for 3D patterning and data storage. Thanks to the interplay of the dual functionalities of metal-organic frameworks (the inherent porosity, and the intrinsic physical and chemical properties of inorganic and organic building blocks and encapsulated guest species), our research efforts have led to the development of functional MOF materials beyond our initial imaginations.

Biofilm formation is a key factor in Vibrio cholerae environmental survival and host colonization. Production of biofilm enables V. cholerae to survive and persist in aquatic environments and aids in the passage through the gastric acid barrier to allow access to the small intestine. The genes involved in biofilm formation are regulated by the transcriptional activators vpsR and vpsT, which are in turn transcriptionally regulated by a number of environmental signals. In this study, the role of the stringent response in biofilm formation was examined. V. cholerae mutants deficient in stringent response had a reduced ability to form biofilms, although they were not completely deficient in biofilm formation. There are three (p)ppGpp synthases in V. cholerae: RelA, SpoT, and RelV. All three synthases were necessary for vpsR transcription, with RelV showing the strongest effect. RelA was the only synthase that was necessary for vpsT expression. Stringent response regulation of vpsR and vpsT was shown to partially occur through rpoS. Biofilm formation in V. cholerae is controlled by a complex regulatory apparatus, with negative regulators of biofilm gene expression, such as quorum sensing, and positive regulators of biofilm genes, including stringent response, interacting to ensure that biofilm formation is coordinated with the environment.