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Gallium‐based liquid metal (LM) is widely used in flexible electronics, optics, and green synthesis due to its excellent conductivity, flexibility, and self‐healing capabilities. However, LM's inherent fluidity and high surface tension greatly limit their practical applications. Therefore, there is a strong demand for developing LM composites that are easy to control and exhibit outstanding performance when used flexibly. In this work, the LM hydrothermal rheological modification method is proposed to synthesize Ga‐coated carbon microparticles, and the highly miscible rheological modification of LM is realized by mixing LM and Ga‐coated carbon microparticles. Including carbon microparticles in the LM improves the mechanical strength of the composite, thereby overcoming the limitation of the LM that has a low mechanical strength. By controlling the volume fraction of carbon microparticles in LM, electrical conductivity is increased by 30% and thermal conductivity by more than 2.0 times that of pure LM. In addition, the fundamental interfacial wetting behavior is demonstrated at the interface of LM and Ga2O3, and the rheological modification mechanism of LM is explained by carbon particles. This work presents a novel method for preparing high‐performance polymer materials and discusses their broad potential applications in thermal interface materials, wireless energy transfer, and flexible electronics. [ABSTRACT FROM AUTHOR]

In this work, the color difference phase separation (CDPS) approach is proposed to segment the solid and pore phases. Pore‐scale variables are defined to describe the microstructural characteristics. Novel relations to quickly determine the deformation moduli and thermal conductivity are established. Digital–virtual modeling to investigate the mechanical and thermal properties is addressed. The correlation between pore‐scale variables and the mechanical and thermal properties is investigated. Results show that the calculated shear and Young's moduli decrease and the computed Poisson's ratio increases as porosity increases. The deformation moduli and thermal conductivity increase with increasing pore radius for different types of rocks. Excellent consistencies are found between the digital–virtual and realistic experimental results. The proposed method provides useful tools to fast and accurately determine the deformation moduli and thermal conductivity, which is helpful for the underground space and deep energy resource explorations. Highlights: Multiphase structure is segmented without overestimation or underestimation.Micro‐deformation moduli and thermal conductivity of rocks are fast determined.Thermo‐mechanical properties are effectively validated in microstructures of rocks. [ABSTRACT FROM AUTHOR]

Strain measurement is crucial for the safety and stability of engineering activities. With the increasing demand for sensors and large strain measurement in engineering monitoring, the study on the large strain measurement is deepening. However, the conventional strain sensors based on rigid conductive materials have limited flexibility and low stretchability, and the research of large strain and flexible sensors in engineering still lacks. In this work, a highly stretchable and sensitive flexible strain sensor based on liquid metal‐Nickle microparticles (LMN) composite is developed to detect large strain. The LMN composite, featuring uniformly dispersed Nickle microparticles within the liquid metal matrix, is deposited onto the elastomer Ecoflex base material.The LMN composite based‐sensor exhibits high sensitivity (GF = 16.14644 at strain of 200%), large stretchability (up to 200%) and low hysteresis. The theoretical relationship between the relative resistance changes and strain is derived, and the theoretical derivation is compared with experimental data to verify the accuracy of theoretical derivation. Additionally, the LMN composite based‐sensors can be used to detect pressure and bending signals in engineering. This work highlights the potential of LMN composite in broad applications and can facilitate the application of flexible sensing devices in engineering. [ABSTRACT FROM AUTHOR]

Post‐synthetic modification plays a crucial role in precisely adjusting the structure and functions of advanced materials. Herein, we report the self‐assembly of a tubular heterometallic Pd3Cu6L16 capsule that incorporates Pd(II) and CuL1 metalloligands. This capsule undergoes further modification with two tridentate anionic ligands (L2) to afford a bicapped Pd3Cu6L16L22 capsule with an Edshammer polyhedral structure. By employing transition metal ions, acid, and oxidation agents, the bicapped capsule can be converted into an uncapped one. This uncapped form can then revert back to the bicapped structure on the addition of Br− ions and a base. Interestingly, introducing Ag+ ions leads to the removal of one L2 ligand from the bicapped capsule, yielding a mono‐capped Pd3Cu6L16L2 structure. Furthermore, the size of the anions critically influences the precise control over the post‐synthetic modifications of the capsules. It was demonstrated that these capsules selectively encapsulate tetrahedral anions, offering a novel approach for the design of intelligent molecular delivery systems. [ABSTRACT FROM AUTHOR]

Metal‐organic cages (MOCs) are supramolecular coordination complexes that have internal cavities for hosting guest molecules and exhibiting various properties. However, the functions of MOCs are limited by the choice of the building blocks. Post‐synthetic modification (PSM) is a technique that can introduce new functional groups and replace existing ones on the MOCs without changing their geometry. Among many PSM methods, covalent PSM is a promising approach to modify MOCs with tailored structures and functions. Covalent PSM can be applied to either the internal cavity or the external surface of the MOCs, depending on the functionality expected to be customized. However, there are still some challenges and limitations in the field of covalent PSM of MOCs, such as the balance between the stability of MOCs and the harshness of organic reactions involved in covalent PSMs. This concept article introduces the organic reaction types involved in covalent PSM of MOCs, their new applications after modification, and summarizes and provides an outlook of this research field. [ABSTRACT FROM AUTHOR]

Hollow nanoporous carbon architectures (HNCs) present significant utilitarian value for a wide variety of applications. Facile and efficient preparation of HNCs has long been pursued but still remains challenging. Herein, we for the first time demonstrate that single‐component metal–organic frameworks (MOFs) crystals, rather than the widely reported hybrid ones which necessitate tedious operations for preparation, could enable the facile and versatile syntheses of functional HNCs. By controlling the growth kinetics, the MOFs crystals (STU‐1) are readily engineered into different shapes with designated styles of crystalline inhomogeneity. A subsequent one‐step pyrolysis of these MOFs with intraparticle difference can induce a simultaneous self‐hollowing and carbonization process, thereby producing various functional HNCs including yolk‐shell polyhedrons, hollow microspheres, mesoporous architectures, and superstructures. Superior to the existing methods, this synthetic strategy relies only on the complex nature of single‐component MOFs crystals without involving tedious operations like coating, etching, or ligand exchange, making it convenient, efficient, and easy to scale up. An ultra‐stable Na‐ion battery anode is demonstrated by the HNCs with extraordinary cyclability (93 % capacity retention over 8000 cycles), highlighting a high level of functionality of the HNCs. [ABSTRACT FROM AUTHOR]

The development of energy‐saving technology for the efficient separation of olefin and paraffin is highly important for the chemical industry. Herein, we report a self‐assembled Fe4L6 capsule containing a hydrophobic cavity, which can be used to encapsulate and separate propylene/propane. The successful encapsulation of propylene and propane by the Fe4L6 cage in a water solution was documented by NMR spectroscopy. The binding constants K for the Fe4L6 cage toward propylene and propane were determined to be (5.0±0.1)×103 M−1 and (2.1±0.7)×104 M−1 in D2O at 25 °C, respectively. Experiments and theoretical studies revealed that the cage exhibited multiple weak interactions with propylene and propane. The polymer‐grade propylene (>99.5 %) can be obtained from a mixture of propylene and propane by using the Fe4L6 cage as a separation material in a U‐shaped glass tube. This work provides a new strategy for the separation of olefin/paraffin. [ABSTRACT FROM AUTHOR]

Realizing high photoluminescence quantum yield (PLQY) in the near‐infrared (NIR) region is challenging and valuable for luminescent material, especially for thermally activated delay fluorescence (TADF) material. In this work, we report two achiral cyclic trinuclear Au(I) complexes, Au3(4‐Clpyrazolate)3 and Au3(4‐Brpyrazolate)3 (denoted as Cl−Au and Br−Au), obtained through the reaction of 4‐chloro‐1H‐pyrazole and 4‐bromo‐1H‐pyrazole with Au(I) salts, respectively. Both Cl−Au and Br−Au exhibit TADF with high PLQY (>70 %) in the NIR I (700–900 nm) (λmax = 720 nm) region, exceeding other NIR−TADF emitters in the solid state. Photophysical experiments and theoretical calculations confirmed the efficient NIR−TADF properties of Cl−Au and Br−Au were attributed to the small energy gap ΔE(S1‐T2) (S = singlet, T = triplet) and the large spin‐orbital coupling induced by ligand‐to‐metal‐metal charge transfer of molecular aggregations. In addition, both complexes crystallize in the achiral Pna21 space group (mm2 point group) and are circularly polarized light (CPL) active with maxima luminescent dissymmetry factor |glum| of 3.4 × 10−3 (Cl−Au) and 2.7 × 10−3 (Br−Au) for their crystalline powder samples, respectively. By using Cl−Au as the emitting ink, 3D‐printed luminescent logos are fabricated, which own anti‐counterfeiting functions due to its CPL behavior dependent on the crystallinity. [ABSTRACT FROM AUTHOR]

In this paper, a nonlocal energy‐informed neural network is proposed to characterize the deformation behaviors of elastic solids with cracks subjected to thermomechanical loads in the framework of ordinary state‐based peridynamics. Based on principle of virtual work, a nonlocal energy approach is developed to recast the solution to peridynamic equilibrium equation as a problem of minimizing the potential energy of the system, which automatically satisfies the traction‐free boundary conditions. Meanwhile, the energy representation of physical system can be treated as the loss function for machine learning methods. Therefore, a nonlocal energy‐informed neural network is constructed to approximate the solution of the system. A distinct advantage of the proposed neural network is that the strain energy is expressed in terms of spatial integration instead of spatial derivatives, which avoids the invalidation of automatic differentiation at the crack surfaces in original physics‐informed neural networks. To demonstrate the convergence and accuracy of the proposed neural network, a series of problems in solid and fracture mechanics are conducted, and compared with results from analytical solutions or classical numerical methods. Additionally, for elastic material containing initial cracks, displacement extrapolation method is encoded into the proposed neural network to evaluate the static stress intensity factor. [ABSTRACT FROM AUTHOR]

To develop a simple and general method for improving the circularly polarized luminescence (CPL) performances of materials is of great significance. In this work, two pairs of CPL‐active homochiral metal–organic frameworks (MOFs) P/M‐Et and P/M‐Et(Cd) with eta topology are reported. In comparison to the reported isomorphic Zn‐imidazolate MOFs P‐Me and M‐Me, both luminescence dissymmetry factor (glum) and photoluminescence quantum yields (ΦPL) of P‐Et and M‐Et are largely improved by simply changing the methyl group to an ethyl group of ligands in P‐Et and M‐Et. Furthermore, the |glum| values are significantly amplified up to 0.015 from 0.0057 by introducing the non‐luminescent halogenated aromatics, while an enhanced fluorescence efficiency is observed simultaneously (from 27.2% to 47.3%). The figure of merit value is about 40 times larger than that of P‐Me and M‐Me. Similarly, the CPL performances of P/M‐Et(Cd) are improved by about five times after encapsulating fluorobenzene molecules. This work represents a new and simple method for developing CPL‐active MOF materials. [ABSTRACT FROM AUTHOR]

Post‐synthetic modification (PSM) is an effective approach for the tailored functionalization of metal‐organic architectures, but its generalizability remains challenging. Herein we report a general covalent PSM strategy to functionalize PdnL2n metal‐organic cages (MOCs, n=2, 12) through an efficient Diels–Alder cycloaddition between peripheral anthracene substituents and various functional motifs bearing a maleimide group. As expected, the solubility of functionalized Pd12L24 in common solvents can be greatly improved. Interestingly, concentration‐dependent circular dichroism and aggregation‐induced emission are achieved with chiral binaphthol (BINOL)‐ and tetraphenylethylene‐modified Pd12L24, respectively. Furthermore, Pd12L24 can be introduced with two different functional groups (e.g. chiral BINOL and achiral pyrene) through a step‐by‐step PSM route to obtain chirality‐induced circularly polarized luminescence. Moreover, similar results are readily observed with a smaller Pd2L4 system. [ABSTRACT FROM AUTHOR]

In the governing equation of motion of bond‐based peridynamics, the acceleration of a material point can be considered as the response function of all the displacements of material points in the horizon and a micro stiffness containing Young's modulus and length scale. A group method of data handling (GMDH) neural network is first developed to explicitly derive the discrete bond‐based peridynamic equation of motion based on measured data in this study rather than traditional complicated mathematical derivation. In order to discover the optimal structure more efficiently and to avoid exhaustive search, genetic algorithm is incorporated into GMDH structure. It is found that the prediction results obtained by GMDH model agree well with measured values both for training and testing data. Moreover, the derived equation of motion is expressed as the product of parameter composed of Young's modulus and length scale and linear combination of displacements of material points in the horizon, which is in accordance with the original bond‐based peridynamic formulation. Furthermore, numerical benchmarks associated with elastic deformation and crack problems are performed and compared with analytical solution or finite element analysis result to verify the validity and feasibility of the proposed model. [ABSTRACT FROM AUTHOR]

The general particle dynamics (GPD), which is based on the kernel approximation method and Navier–Stokes equation, was developed from smoothed‐particle hydrodynamics to simulate the fracture behaviors by using the collective of damage variable to describe the damage evolution behaviors. In this paper, an advanced GPD with a nonlocal foundation is proposed for better description of the solid mechanics. The nonlocal vector calculus and microscopic constitutive model are employed to derive the governing equations in the proposed theory. The novel GPD with a nonlocal core is a generalization, which permits the inclusion of the microscopic constitutive model and the multi‐scale modeling compared with the previous GPD. To accomplish this generalization, the relationship between GPD and the previous kernel‐based theory is established. The novel GPD is superior in the fracture problems and multi‐scale modeling. Some numerical experiments are launched to verify the ability of the novel GPD. Highlights: Advanced GPD with nonlocal foundation for is proposed for better description of the solid mechanics.The governing equations are re‐derived by nonlocal vector calculus and micro‐bond model.The advanced GPD is good at handling with multi‐scale problem and fracture problems. [ABSTRACT FROM AUTHOR]

In this paper, the effects of materials and confining pressures on the mechanical properties of flawed coarse and fine sandstone is first analyzed. Then, the evolution processes of spatiotemporal acoustic emission (AE) events of coarse and fine sandstone specimens containing two flaws subjected to biaxial compression are investigated to character the damage characteristics and the fracture mechanism. Third, the ultimate failure modes of coarse sandstone specimens are compared with those of the fine sandstone specimens. Finally, the Electron Probe Microscope Analysis (EPEI) technique is conducted to observe the main macrofracture surfaces of coarse and fine sandstone specimens. Besides, the distribution characteristics of two AE indexes are also employed to qualitatively reveal the failure mechanism of tested specimens. The experimental results can provide new insight into the mechanical responses and the cracking behaviors of flawed rocks in complex stress loading conditions. Highlights: The damage characteristics and the fracture mechanism of coarse and fine sandstone are revealed.The distribution characteristics of two AE indexes are employed to qualitatively reveal the failure mechanism.Electron Probe Microscope Analysis technique is conducted to observe the main macrofracture surfaces of sandstone.The ultimate failure modes of coarse and fine sandstone specimens are investigated. [ABSTRACT FROM AUTHOR]

Creep behavior of red sandstone under different pore pressures with a high temperature and confining pressure condition is studied in this paper. Ultrasonic detection method is used to monitor the variation of S wave in the creep test. The attenuation coefficient and S‐wave velocity in the creep process are analyzed. Fast Fourier transform is used to analyze the variation of amplitude in peak frequency and four main frequencies. The experimental results show that the creep deformation increases with increasing pore pressure for a given deviatoric stress, and the S‐wave velocity and attenuation coefficient decrease with increasing pore pressure. The relationship between creep strain and damage of the sample is established. It is found that the increase of pore pressure accelerates the increased rate of sample damage. Frequency spectrum analysis shows that the generation and development rate of microcracks increases with increasing pore pressure. The research can provide a theoretical basis for mining of deep mineral resources and the structural stability analysis of deep underground engineering. Highlights: Creep behavior of red sandstone under different pore pressures with a high temperature and confining pressure condition is studied.Fast Fourier transform is used to analyze the variation of amplitude in peak frequency and four main frequencies.The S‐wave velocity and attenuation coefficient decrease with increasing pore pressure.The increase of pore pressure accelerates the increased rate of sample damage. [ABSTRACT FROM AUTHOR]

Characteristics of stick–slip shear failure under mode II conditions are experimentally investigated using a bimaterial system (consisting of granite and basalt) with a simulated fault. This experimental study is concerned with the effects of normal stress, shear rate, and fault roughness on the stick–slip behaviors along the heterogeneous faults. Highly non‐uniform stress distribution along the simulated fault dictates the initiation of stick–slip failure. The nucleation starts at a firstly yielded material point, and as the energy accumulates in the heterogeneous fault, the nucleation zone is progressively formed and transited into unstable rupture. This experimental study aims at gaining scientific insights regarding earthquake source processes. Highlights: Characteristics of stick–slip shear failure are experimentally investigated by a bimaterial system.The effects of normal stress, shear rate, and fault roughness on the stick–slip behaviors along the faults are studied.Highly non‐uniform stress distribution along the simulated fault dictates the initiation of stick–slip failure. [ABSTRACT FROM AUTHOR]

The fabrication of circularly polarized luminescence (CPL) active materials by self‐assembly is still in its challenge. In this work, a family of homochiral metal–organic frameworks (MOFs) and metal–organic cages (MOCs) are constructed by solvothermal subcomponent self‐assembly. These MOFs feature an eta topology with trifold helical chains, while the MOCs adopt a cubic cage structure. The chiral ligands show two distinct types of conformations: "opened" and "closed" in MOFs and MOCs, respectively. Although homochiral MOFs and MOCs show similar spectra of circular dichroism and photoluminescence with similar quantum yields and lifetimes, the MOFs yield clear CPL signals and the CPL of MOCs are silent. The turn‐on CPL in MOFs achieved by tuning the conformation of ligands and controlling self‐assembly provides a new approach for development of CPL‐active MOF materials. [ABSTRACT FROM AUTHOR]

Heterogeneity representations of rocks can bring out large errors due to inaccurate partitions of different phases. This study aims to deeply characterize the microscopic heterogeneity in rocks represented by different phases and to study their effects on damage properties of sandstone. X‐ray μ‐CT imaging with low‐high resolution is applied to capture microstructures information. Digital analysis with statistical models is employed to accurately characterize the heterogeneity. The effects of microscopic heterogeneity on the damage properties are analyzed using the numerical simulations and coupling multiple point statistic‐marching cube three‐dimensional reconstruction algorithm. Results show that the microscopic heterogeneity of sandstone can be effectively characterized by Lorentz distribution model, and model with high resolution shows better R2 values. With increasing segmentation accuracy of microscopic phases, micro‐grain‐2 phase plays decisive roles in determining the compressive strength of sandstone. The microscopic samples S1‐S2 are failed by the mixed modes of transgranular and intergranular failures. Plain Language Summary: Digital rock assessment techniques play significant roles in evaluating the petro‐physical properties of different rocks via X‐ray CT imaging. The simulations of the microscopic cracking behaviors are extremely dependent on the multiphase heterogeneity representations of rocks, which can bring out large errors due to inaccurate partitions of different phases. To settle this issue, the digital color difference segmentation algorithm and the statistical Lorentz distribution model for the microscopic element of rocks are applied to accurately represent the heterogeneity of rocks. The effects of microscopic heterogeneity on the damage properties are analyzed using the numerical simulations in sandstone with realistic geometries reconstructed by the coupling multiple point statistic‐marching cube three‐dimensional reconstruction algorithm. We demonstrate that transgranular and intergranular failure behaviors of rocks can be intuitively analyzed. The presented method provides new opportunities to study microscopic damage and mechanical properties of porous rocks. Key Points: Digital analysis with statistical models is employed to accurately characterize the heterogeneity of sandstoneMicroscopic heterogeneity effects on damage properties are analyzed by the numerical simulations and multiple point statistic‐marching cube three‐dimensional reconstruction algorithmMicroscopic transgranular and intergranular cracking behaviors can be intuitively analyzed based on the microscopic element of rocks [ABSTRACT FROM AUTHOR]

Rock properties evaluations play decisive roles in various geotechnical engineering programs. This work aims at establishing a digital rock parameters computation theory framework system (DRPCTS) to rapidly and accurately obtain the common pore‐scale, hydraulic, and thermophysical variables by micro‐CT images. The proposed package contains the codes for the pore‐scale, hydraulic, and thermophysical variables expressions defined by the digital analysis techniques. Some experimental rock properties datasets are given to validate the accuracy of DRPCTS. The DRPCTS package provides excellent tools to rapidly obtain the common rock properties parameters only using some micro‐CT datasets as the input parameters with simple implementations. [ABSTRACT FROM AUTHOR]

The purpose of this review is to discuss the development and the contribution of the experiments and numerical simulations in compression‐induced failure characteristics of flawed rock specimens. Investigation is essential to understand the fundamental failures occurring in a rock bridge, for assessing anticipated and actual performances of the structures built on or in rock masses. The review begins by representing and discussing compression‐induced crack initiation and growth in flawed rocks and explaining the significance of studying these issues in Section 1. The crack initiation and growth behaviors in flawed rocks under uniaxial, biaxial, and triaxial compressions are described in depth in Section 2 where it is expected to distinguish 2‐D crack growth from 3‐D crack growth. After that, the failure characteristics of flawed rock specimens due to temperature treatments and hydraulic pressure are systematically reviewed. Numerical studies of the compression‐induced failure characteristics of flawed rock specimens based on different numerical theories and numerical models are comprehensively evaluated in Section 3. In Section 4, the new findings obtained recently from experimental and numerical studies are drawn. Finally, some aspects of prospective research and a brief summary are presented in Sections 5 and 6. [ABSTRACT FROM AUTHOR]

Summary: X‐ray computed tomography (CT) imaging and digital image correlation techniques are applied to study spatial cracking behaviors of sandstone under uniaxial compression, in which the angle between precracks is 45°, 90°, and 135° and the crack depth is 7.5 mm and 10 mm, respectively. Layered anisotropy damages and spatial cracking evolution are quantitatively analyzed by the defined digital layered anisotropy index and digital damage ratio, respectively. Three cases with different array of precracks evidence the depth effects of precracks on spatial crack propagation. Results show that the failure process of samples is first controlled by the coalescence of surface cracks in 2D space and then the samples are failed by the propagation of coalesced cracks (shear cracks with different shapes). The crack types for samples with precrack depth of 7.5 mm are all shear cracks for Cases 1‑3. Nevertheless, the crack types for samples with precrack depth of 10 mm are, respectively, the half X‐shape crack for Case 1, X‐shape crack for Case 2, and double shell crack for Case 3. The precrack has a significant promotion effect on the failure process when the angle between the two precracks is β = 90°, and the precrack has little to no effect on the failure process when the angle between the two precracks is β = 135°. As the depth of precrack increases to 10 mm, the crack types are changed in this study. The peak strength of sample subjected to uniaxial compression decreases with increasing depth of precracks, implying the decrease of the rock strength by the discontinuity. [ABSTRACT FROM AUTHOR]

An evidently precursory acoustic emission (AE) time series, characterized by a time‐reversed Omori law, is registered prior to the unconfined catastrophic rupture of brittle sandstone. This provides insights into the physical process controlling catastrophic rupture and underlies the failure forecast. The onset of acceleration of damage is first identified based on the acousto‐optical characteristics. The precursory time series of rise time (RT) rate is used to forecast pseudo‐prospectively the catastrophic rupture in the framework of the time‐reversed Omori law. Investigations on multiple unconfirmed failure cases on the laboratory scale show that forecasts become more precise and less biased as the precursory AE time series proceeds toward rupture. In contrast to retrospective forecast, pseudo‐prospective forecast obtains a higher quality. Moreover, the use of amplitude as a precursor benefits the increase of warning time, and the flaw‐to‐flaw interaction introduces a strong disturbance on the forecast. Plain Language Summary: Catastrophic rupture in brittle rocks has important consequences for natural hazards such as landslides, earthquakes, or cliff collapses. Forecasting the catastrophe time of brittle rocks, albeit challenging even to this day, is much concerned by seismologists, physicists, and engineers. Encouragingly, an evidently precursory acoustic emission (AE) time series is commonly registered in the approach to the catastrophic rupture in the laboratory. Precursory AE time series is well characterized by a time‐reversed Omori law, which underlies the predictability of catastrophic rupture. In the forecast, RT rate, reflecting physically the damage progressions with a constantly intensifying shear mechanism in the approach to the catastrophic rupture, is used as a potential precursor. By using the time‐reversed Omori law, an accurate forecast of catastrophic rupture is achieved as the precursory time series of RT rate proceeds toward rupture. Key Points: The onset of acceleration of damage is identified using the acousto‐optical dataPseudo‐prospective forecast outperforms retrospective forecast in the forecast qualityThe flaw‐to‐flaw interaction introduces a strong disturbance on the forecast [ABSTRACT FROM AUTHOR]

A pair of enantiomers of three‐dimensional (3D) chiral coordination polymers (CCPs) were successfully constructed by using achiral components 4,2′:6′,4′′‐terpyridyl precursors and Cu2+ through spontaneous resolution (1 a). By utilising feeding controlled chiral‐templated induction and chiral auxiliary behaviour of optically pure camphor sulfonate (CSA), the enantioenriched (1 b‐P and 1 b‐M) and CSA captured (1 c‐P and 1 c‐M) CCPs were successfully synthesised, respectively. The chiral information of the corresponding products was confirmed by X‐ray single crystal diffraction and solid‐state CD spectra. Meanwhile, the formation processes of 1 b‐P and 1 b‐M were monitored through solution CD spectra, UV/Vis spectra and ESI‐TOF MS. Based on these results, a reasonable chiral‐templated induction mechanism of forming 1 b‐P and 1 b‐M was proposed. [ABSTRACT FROM AUTHOR]

In this paper, uniaxial compression tests are conducted on fissured red sandstone specimens to predict fracture damage (large‐scale events). The acoustic mission (AE) coupled with digital image correlation (DIC) technologies are used to monitor and record the real‐time cracking process of tested specimens. The AE characteristics are analysed during the cracking process. Moreover, three types of b‐value methods based on the AE parameters are adopted to predict the occurrence of large‐scale events (macro‐cracking). The results show that every macro‐cracking leads to a rapid decrease in three types of b value. When the fissured specimens reach to ultimate failure, all three types of b value reach to the minimum. The b value based on the AE parameters can be used as a predictor of large‐scale events during the cracking process of fissured rocks. [ABSTRACT FROM AUTHOR]

Summary: An integrated approach of improved pseudo color image enhancement (IPCE) method and three‐dimensional (3D) reconstruction technology is proposed. The evolution characteristics of two‐dimensional (2D) and 3D spatial cracks in X‐ray computed tomography (CT) images of sandstones subjected to triaxial compression with confining pressure of 10, 20, and 30 MPa are investigated. The equations of crack width, length, and dip angle are established based on the proposed digital damage ratio. Based on the pseudo color images, point cloud maps with roughness and spatial images of cracks are investigated. The numerical results show that this proposed method is effective to study and understand the fracturing properties of rocks. [ABSTRACT FROM AUTHOR]

A family of gyroidal metal–organic frameworks (STUs) composited with transition metal ions and bi‐imidazolate ligands (BIm) were prepared and applied as both Lewis base and acid catalysts. Benefiting from the intrinsic basicity of the ligands and the Lewis acidic sites of the open metal centres, the STUs materials show excellent catalytic activities as Lewis base for the Knoevenagel condensation reaction between various aldehydes and malononitrile, and as Lewis acid for cyanosilylation reactions. Among these STUs, STU‐4 (Ni(BIm)) shows the best catalytic efficiency (conversions >99 %) in both Knoevenagel condensation and cyanosilylation reactions under mild conditions, providing thus an advanced material for both Lewis base and Lewis acid catalysis. [ABSTRACT FROM AUTHOR]

Uniaxial compression tests combined with nondestructive testing techniques are performed to explore the roles of non‐isometric flaws in crack developments in brittle rocks. The acoustic emission (AE) rate‐process theory is adopted to analyze fracture‐related AE event rate characteristics. The full‐field optical method is applied to detect cracking modes. Experimental results show that AE activity is quite active when the matrix microcracking is dominant, while after each macrocracking event, AE activity becomes inactive because of the stress release. Multiphysical data for each tested flaw configuration faithfully confirm the rupture progressivity. The larger the flaw length ratio, the lower the peak stress (also peak axial strain and elastic modulus), as well as the more progressive the cracking process. Moreover, ultimate failure is triggered by the shear fracturing from the relatively long flaw. The short flaw is conditionally involved in ultimate failure when the stress buildup effect dominates. Finally, the fracture mechanism of brittle rocks with non‐isometric flaws is revealed. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of freeze‐thaw (FT) fatigue damage on the cracking behaviors of sandstone specimens containing two unparallel fissures under uniaxial compression. First, the effects of FT fatigue damage and fissure angle on the mechanical properties of sandstone specimens are analyzed. Second, the real‐time cracking process of sandstone specimens is captured by a high‐speed digital video camera system. Seven crack coalescence patterns are observed in this experiment. Local strong fatigue‐damaged zones, which are visualized as white zones, are observed in the specimens subjected to FT cycles during loading. Finally, scanning electron microscopy (SEM) observations show that the local strong fatigue‐damaged zones mainly consisted of microcracks and micropores induced by the FT fatigue damage. These experimental results are helpful for improving the understanding of the cracking process in cold‐region engineering. [ABSTRACT FROM AUTHOR]

Cracking is an important phenomenon in the failure of geomaterials. The prediction of crack paths is difficult and challenging because of the randomness and uncertainty in the cracking behaviors of geomaterials. In this paper, to predict crack paths based on 2D X‐ray computed tomography (CT) images, a digital energy grade‐based approach is proposed, and the corresponding energy principle is established. Excellent consistency of crack paths is found between the predicted crack path and the real crack path of the specimen. The numerical results indicate that the proposed approach provides a useful way to predict cracking paths in geomaterials. Meanwhile, the stress and displacement fields before and after the specimen fails can be obtained by combining the proposed method with finite element (FE) analysis. In total, this proposed method can be applied not only to monitoring the health of but also to the stability analysis of engineering structures during engineering activities. [ABSTRACT FROM AUTHOR]

A trigonal prismatic Cu6L3 coordination cage has been assembled from Cu(I) and semi‐rigid bipyrazolyl ligand. The X‐ray crystallography demonstrates that the cage has a cavity and can encapsulate the toluene as a guest, exhibiting thermochromism phenomenon. Empty cage can be obtained by expulsion of the guest through single crystal to single crystal transformation. After removed the guest, the empty cage shows a blue‐shifted emission (580 nm), in comparison to its parent cage (615 nm). The empty cage could further serve as a host to encapsulate other aromatic molecules (e. g. mesitylene), which shows new emission band. The trigonal prismatic Cu6L3 coordination cage provides a platform to make advanced luminescent materials. [ABSTRACT FROM AUTHOR]

In this paper, a novel geometric method combined with the piecewise linear function method is introduced into the extended finite element method (XFEM) to determine the crack tip element and crack surface element. Then, by combining with the advanced mesh technique, a novel method is proposed to improve the modelling of crack propagation in triangular 2D structure with the XFEM. The numerical tests show that the accuracy, the convergence, and the stability of the XFEM can be improved using the proposed method. Moreover, the applicability of the conventional multiple enrichment scheme is discussed. Compared with the proposed method, the conventional multiple enrichment scheme has deficiency in mixed mode I and II crack. Finally, a comparative study shows that the performance of the XFEM by using the proposed method to model the crack propagation can be greatly improved. [ABSTRACT FROM AUTHOR]

A variety of planar organic fluorophores (R=phenyl, naphthalenyl, pyrenyl) and luminescence promotors (X=Cl, Br, I) were equipped, respectively, on the alternatively arranged vertices of cubic ZnII‐imidazolate cages through orthogonal subcomponent self‐assembly. It was found that supramolecular interactions, especially weak C−H⋅⋅⋅X interactions, play a key role in activating an efficient radiative pathway, coupled with reduced nonradiative decay rate through metal coordination, therefore significantly boosting the emission quantum yields of the system. This finding provides a strategy that utilizes molecular geometry and supramolecular interactions to modulate the emission efficiency of luminescent cage‐based materials. [ABSTRACT FROM AUTHOR]

A novel isohedral 3-periodic net (i.e. a net with one kind of tile), showing a Cairo pentagonal tiling projection on the Euclidean plane, has been identified in a series of site-modified CuCN/CuSCN networks, namely, [Cu6(SCN)2(CN)6⋅Ni(tpy)2] n ( 1), [Cu6(SCN)(CN)7⋅Ni(tpy)2] n ( 2) and [Cu6(CN)8⋅Ni(tpy)2] n ( 3) (tpy=2,2′:6′′,2′′-terpyridine). These infinite inclusion compounds were prepared via a solvothermal sulfur migration reaction with subtle modification to fine-tune the sulfur content. The chiroptical activity of single crystals, which arises from the intrinsically chiral net, was confirmed by X-ray diffraction and solid-state circular dichroism spectra. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) can be classified into different types. Chromosomal instable (CIN) colon cancers are thought to be the most common type of colon cancer. The risk of developing a CIN-related CRC is due in part to inherited risk factors. Genome-wide association studies have yielded over 40 single nucleotide polymorphisms (SNPs) associated with CRC risk, but these only account for a subset of risk alleles. Some of this missing heritability may be due to gene-gene interactions. We developed a strategy to identify interacting candidate genes/loci for CRC risk that utilizes both linkage and RNA-seq data from mouse models in combination with allele-specific imbalance (ASI) studies in human tumors. We applied our strategy to three previously identified CRC susceptibility loci in the mouse that show evidence of genetic interaction: Scc4, Scc5 and Scc13. 525 SNPs from genes showing differential expression in the mouse and/or a previous role in cancer from the literature were evaluated for allele-specific imbalance in 194 paired human normal/tumor DNAs from CIN-related CRCs. One hundred three SNPs showing suggestive evidence of ASI (31 variants with uncorrected p values < 0.05) were genotyped in a validation set of 296 paired DNAs. Two variants in SNX10 ( SCC13) showed significant evidence of allelic selection after multiple comparisons testing. Future studies will evaluate the role of these variants in combination with interacting genetic partners in colon cancer risk in mouse and humans. [ABSTRACT FROM AUTHOR]

Biological function arises by the assembly of individual biomolecular modules into large aggregations or highly complex architectures. A similar strategy is adopted in supramolecular chemistry to assemble complex and highly ordered structures with advanced functions from simple components. Here we report a series of diamond-like supramolecular frameworks featuring mesoporous cavities, which are assembled from metal-imidazolate coordination cages and various anions. Small components (metal ions, amines, aldehydes, and anions) are assembled into the hierarchical complex structures through multiple interactions including covalent bonds, dative bonds, and weak CH⋅⋅⋅X (X=O, F, and π) hydrogen bonds. The mesoporous cavities are large enough to trap organic dye molecules, coordination cages, and vitamin B12. The study is expected to inspire new types of crystalline supramolecular framework materials based on coordination motifs and inorganic ions. [ABSTRACT FROM AUTHOR]

Three 2D luminescent isomeric porous coordination polymers are synthesized and characterized. Their luminescence properties can be modified by grinding and they can act as mechanochromic materials and their properties are probably related to the weak interactions of cuprophilicity and π-π interactions. [ABSTRACT FROM AUTHOR]

Reduction of Ti4+ to Ti3+ was found in boron-doped BaTiO3 ceramics when we sintered the samples at very low temperature (>850°C) in 5%H2/Ar. Such reduction did not occur in pristine BaTiO3 ceramic. The methods such as UV-vis spectroscopy, luminescence spectroscopy, and X-ray photoelectron spectroscopy confirmed the reduction by showing the presence of Ti3+. The results of Ti-K-edge X-ray absorption near-edge structure measurement ( XANES) indicated that boron doping changed the geometry of Ti-oxygen in BaTiO3 to some extent. It was likely that some boron ions stayed at interstitial sites of BaTiO3 lattice and acted as donors, which might trigger the reduction. The reduced boron-doped BaTiO3 were semiconducting and had very low room-temperature resistivity (<100 Ω m). However, different from the n-type rare-earth-doped BaTiO3 ceramics, they did not display positive temperature coefficient resistance ( PTCR) behavior. [ABSTRACT FROM AUTHOR]

A new catalytic process for p-xylene synthesis from the methylation of toluene with CH3Br was proposed. CH3Br was prepared from the catalytic bromination of natural gas (CH4), by using H2O + HBr + O2 as mediator over supported Rh catalyst. The methylation conditions were investigated using HZSM-5 or modified HZSM-5 catalyst. Under optimal reaction conditions, p-xylene selectivity is up to 93%, and p-xylene yield is more than 21% at 673 k over the Si-P modified HZSM-5 catalyst. Compared to the processes using MeOH or dimethyl carbonate (DMC) as methylation agent, this new process is very attractive in an economic standpoint since CH4 is much cheaper than MeOH and DMC. In addition, the process has other advantages, such as mild reaction conditions, simple operation, high-product yield, and so on. It is predicted that the process has good industrial potential for para-xylene production. © 2012 American Institute of Chemical Engineers AIChE J, 59: 532-540, 2013 [ABSTRACT FROM AUTHOR]

Recent progress in cancer biology research has shown that abnormal proliferation in tumor cells can be attributed to aberrations in cell cycle regulation, especially in G1 phase. During the course of searching for microbial metabolites that affect cell cycle distribution, we have found that simaomicin α, a polycyclic xanthone antibiotic, arrests the cell cycle at G1 phase. Treatment of T-cell leukemia Jurkat cells with 3 nM simaomicin α induced an increase in the number of cells in G1 and a decrease in those in G2–M phase. Cell cycle aberrations induced by simaomicin α were also detected in colon adenocarcinoma HCT15 cells. Simaomicin α had antiproliferative activities in various tumor cell lines with 50% inhibitory concentration values in the range of 0.3–19 nM. Furthermore, simaomicin α induced an increase in cellular caspase-3 activity and DNA fragmentation, indicating that simaomicin α promotes apoptosis. The retinoblastoma protein phosphorylation status of simaomicin α-treated cell lysate was lower than that of control cells, suggesting that the target molecule of simaomicin α is in a pathway upstream of retinoblastoma protein phosphorylation. In the course of evaluating polycyclic xanthone antibiotics structurally related to simaomicin α, we also found that cervinomycin A1 stimulated accumulation of treated cells in G1 phase. These results indicate that the polycyclic xanthones, including simaomicin α and cervinomycin A1, may be candidate cancer chemotherapeutic agents. ( Cancer Sci 2009; 100: 322–326) [ABSTRACT FROM AUTHOR]

Front Cover: Bifunctional Gyroidal MOFs: Highly Efficient Lewis Base and Lewis Acid Catalysts (Chem. Keywords: Catalysis; Knoevenagel condensation reaction; Lewis acid; Lewis base; Metal-organic frameworks Catalysis, Knoevenagel condensation reaction, Lewis acid, Lewis base, Metal-organic frameworks. [Extracted from the article]