Frost protection mechanism based on rubber airbag interlayered composite lining system for cold-region tunnels.

To solve the problem of freezing damage in cold-region tunnels, this study proposed a rubber airbag interlayered composite lining system, and tested its performance of buffering, pressure adjustment, waterproofing, and heat preservation by simulating a low-temperature environment in an artificial freezing chamber. The experiment results show that the frost-heaving force exerted on the lining can always be lower than 1.69 kPa by constantly adjusting the airbag pressure, and the maximum frost-heaving force can reach 28.25 kPa without the airbag. In addition, the airbag also has good waterproof performance. Finally, the airbag can significantly improve the temperature field of the surrounding rock and reduce the freezing depth (6.75 cm < 17.25 cm). The insulation effect of the airbag is positively correlated with its thickness and negatively correlated with the thermal conductivity of the filling gas. The insulation effect of CO2 is better than that of air. The rubber airbag interlayered composite lining system provides a new scheme for freezing damage control in cold-region tunnels.

Accurate estimation of concrete consumption in tunnel lining using terrestrial laser scanning.

Accurate estimation of concrete (including shotcrete) consumption plays a crucial role in tunnel construction. A novel method has been introduced to accurately estimate concrete consumption with terrestrial laser scanning (TLS). The estimation needs to capture TLS data of tunnel surfaces at different stages of construction. Unrolling point clouds, a novel two-stage algorithm consisting of noise removal and hole filling has been used to generate resampled points. Furthermore, resampled points from two scans (before and after lining construction) ultimately generate an innovative computation model composed of multiple hexahedral elements, which is used for calculating volumes. The proposed technique was applied to the Tiantaishan highway tunnel and Da Fang Shan high-speed railway tunnel. The calculation relative error of the rebound rate is 0.19%, and the average relative error in predicting the demand for secondary lining concrete is 0.15%. Compared with 3D Delaunay with curve fitting, the proposed technique offers a more straightforward operation and higher accuracy. Considering factors such as tunnel geometry, support design, and concrete properties, a computational model will provide valuable insights into optimizing resource allocation and reducing material waste during construction.

Experimental study on the damage performance and forced response of concrete lining in fault-crossing tunnel.

Understanding the adverse effects of tunnel crossing active faults on tunnel structures is crucial for ensuring their safe operation and construction. This paper presents the results of a series of model tests conducted at a scale of 1:40 using a fault sliding test box. Three sets of fault comparison tests were carried out, namely: (1) the tunnel does not cross the fault, (2) the spring stiffness is reduced, and (3) the model is not reinforced. The objective was to study the failure characteristics of tunnels crossing active faults. The findings reveal that when the hanging wall moves downwards, cracks appear on the surrounding rock surface of the hanging wall, specifically above the tunnel lining crossing the fault. The lining is significantly damaged within the range of - 30-+ 30 cm. All points of axial force exhibit an increasing compression trend. The section of axial force and bending moment near the fault fracture surface is notably larger than that far from the fault fracture surface. The safety factor of the entire structure decreases sharply after dislocation, making the tunnel more susceptible to cracking at various locations such as the vault, arch waist, left and right arch feet, and inverted arch. It has been proven that the shear compression of the fracture surface during fault dislocation is the main cause of longitudinal through cracks in the lining. The use of springs with higher stiffness effectively ensures the reciprocating dislocation of the upper and foot walls, with long duration and large displacement, providing a better simulation of the dislocation of active faults.

Aloperine: A Potent Modulator of Crucial Biological Mechanisms in Multiple Diseases.

Aloperine is an alkaloid found in the seeds and leaves of the medicinal plant Sophora alopecuroides L. It has been used as herbal medicine in China for centuries due to its potent anti-inflammatory, antioxidant, antibacterial, and antiviral properties. Recently, aloperine has been widely investigated for its therapeutic activities. Aloperine is proven to be an effective therapeutic agent against many human pathological conditions, including cancer, viral diseases, and cardiovascular and inflammatory disorders. Aloperine is reported to exert therapeutic effects through triggering various biological processes, including cell cycle arrest, apoptosis, autophagy, suppressing cell migration, and invasion. It has also been found to be associated with the modulation of various signaling pathways in different diseases. In this review, we summarize the most recent knowledge on the modulatory effects of aloperine on various critical biological processes and signaling mechanisms, including the PI3K, Akt, NF-κB, Ras, and Nrf2 pathways. These data demonstrate that aloperine is a promising therapeutic candidate. Being a potent modulator of signaling mechanisms, aloperine can be employed in clinical settings to treat various human disorders in the future.

Synthesis of flowerlike carbon nanosheets from hydrothermally carbonized glucose: an in situ self-generating template strategy.

A reliable in situ self-generating template strategy has been developed for the synthesis of flowerlike carbon nanosheets by hydrothermal carbonization in the presence of both silica and zinc acetate using glucose as the carbon source. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), Raman spectroscopy, nitrogen sorption isotherm measurement (BET) and element analysis revealed the morphology, crystal phase structure, porosity and chemical composition. The formation of the zinc silicate nanosheet template was due to the hydrolysis of amorphous silica and self-assembly under hydrothermal conditions. The resulting flowerlike carbon nanosheets proved to be an excellent palladium catalyst support.

Automatic Extraction of Tunnel Lining Cross-Sections from Terrestrial Laser Scanning Point Clouds.

Tunnel lining (bare-lining) cross-sections play an important role in analyzing deformations of tunnel linings. The goal of this paper is to develop an automatic method for extracting bare-lining cross-sections from terrestrial laser scanning (TLS) point clouds. First, the combination of a 2D projection strategy and angle criterion is used for tunnel boundary point detection, from which we estimate the two boundary lines in the X-Y plane. The initial direction of the cross-sectional plane is defined to be orthogonal to one of the two boundary lines. In order to compute the final cross-sectional plane, the direction is adjusted twice with the total least squares method and Rodrigues' rotation formula, respectively. The projection of nearby points is made onto the adjusted plane to generate tunnel cross-sections. Finally, we present a filtering algorithm (similar to the idea of the morphological erosion) to remove the non-lining points in the cross-section. The proposed method was implemented on railway tunnel data collected in Sichuan, China. Compared with an existing method of cross-sectional extraction, the proposed method can offer high accuracy and more reliable cross-sectional modeling. We also evaluated Type I and Type II errors of the proposed filter, at the same time, which gave suggestions on the parameter selection of the filter.

A Copper-Based Metal-Organic Framework as an Efficient and Reusable Heterogeneous Catalyst for Ullmann and Goldberg Type C-N Coupling Reactions.

A highly porous metal-organic framework (Cu-TDPAT), constructed from a paddle-wheel type dinuclear copper cluster and 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine (H6TDPAT), has been tested in Ullmann and Goldberg type C-N coupling reactions of a wide range of primary and secondary amines with halobenzenes, affording the corresponding N-arylation compounds in moderate to excellent yields. The Cu-TDPAT catalyst could be easily separated from the reaction mixtures by simple filtration, and could be reused at least five times without any significant degradation in catalytic activity.

Poly[[µ-aqua-triaqua-[µ(6)-1,3,4,6-tetra-kis-(carboxyl-atometh-yl)-7,8-diphenyl-glycoluril]dizinc] monohydrate].

In the crystal structure of the title coordination polymer, {[Zn(2)(C(24)H(18)N(4)O(10))(H(2)O)(4)]·H(2)O}(n), the mol-ecular building block (MBB), viz [Zn(2)(CO(2))(4)(H(2)O)(4)], comprises two Zn(II) cations, each bridged by three carboxyl-ate groups from different ligand mol-ecules. These two Zn(II) cations exhibit different coordination environments: a distorted trigonal-pyramidal coordination, as an inter-mediate, is formed by the two coordinated water mol-ecules and three carboxyl-ate groups, and a distorted octa-hedral geometry defined by three water mol-ecules and three carboxyl-ate groups, in which two carboxyl-ate groups from the same side of the clip glycoluril ring and one water mol-ecule are bidentate bridging, whereas others are monodentate units. Every ligand mol-ecule connects four MBBs, thus forming a three-dimensional structure. Extensive intra- and inter-molecular O-H⋯O hydrogen bonding is observed.

Poly[[bis-(dimethyl-formamide)[µ(7)-5,5'-(methyl-enedi-oxy)diisophthalato]dizinc] dimethyl-formamide monosolvate].

In the crystal structure of the title coordination polymer, {[Zn(2)(C(17)H(8)O(10))(C(3)H(7)NO)(2)]·C(3)H(7)NO}(n), the mol-ecular build-ing block (MBB), viz. {Zn(2)(CO(2))(4)(C(3)H(7)NO)(2)}, comprises two zinc atoms, each bridged by three carboxyl-ate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal-pyramidal, and square-pyramidal formed by the two coordinated dimethyl-formamide mol-ecules and three carboxylate groups, and a distorted tetra-hedral coordination defined by carboxy-late groups of which three are bidentate bridging and the fourth is a monodentate ligand. Thus, each ligand connects four MBBs, forming the three-dimensional polymer.

Structural diversity through ligand flexibility: two novel metal-organic nets via ligand-to-ligand cross-linking of "paddlewheels".

Solvothermal reaction of a partially flexible ligand, H(4)L, and Cu(NO(3))(2)·2.5H(2)O afforded two cross-linked Kagomé lattices of formula [Cu(2)(L)](n): an acs net sustained by novel trigonal prismatic supermolecular building blocks (SBBs) and the first example of a partially pillared Kagomé net.

catena-Poly[[bis-(pyridine-κN)zinc(II)]-µ-benzene-1,4-dicarboxyl-ato-κO:O].

In the title coordination polymer, [Zn(C(8)H(4)O(4))(C(5)H(5)N)(2)](n), the Zn(II) atom, located on a twofold rotation axis, is tetra-coordinated by two monodentate O atoms from two different carboxyl-ate groups and two pyridyl N atoms, forming a distorted tetra-hedral geometry. The Zn(II) atoms are bridged by terephthalate ligands, generating an infinite zigzag chain along [101].

Interaction of water-soluble cationic porphyrin with anionic surfactant.

The interaction of a cationic water-soluble porphyrin, 5,10,15,20-tetrakis [4-(3-pyridiniumpropoxy)phenyl]porphyrin tetrakisbromide (TPPOC3Py), with anionic surfactant, sodium dodecyl sulfate (SDS), in aqueous solution has been studied by means of UV-vis, (1)H NMR, fluorescence, circular dichroism (CD) spectra and dynamic laser light scattering (DLLS), and it reveals that TPPOC3Py forms porphyrin-surfactant complexes (aggregates), including ordered structures J- and H-aggregates, induced by association with surfactant monomers below the SDS critical micelle concentration (cmc), and forms micellized monomer upon the cmc, respectively. The position of TPPOC3Py in the micelle is determined, which is not in the micelle core instead of intercalated among the SDS chains, most likely with the pyridinium group extending into the polar headgroup region of the micelle.

Study on the inclusion behavior between meso-tetrakis[4-(3-pyridiniumpropoxy)phenyl]prophyrin tetrakisbromide and beta-cyclodextrin derivatives in aqueous solution.

The interaction of a cationic water-soluble porphyrin, 5,10,15,20-tetrakis[4-(3-pyridiniumpropoxy)phenyl]prophyrin tetrakisbromide (TPPOC3Py), with beta-CD and HP-beta-CD in aqueous solution has been studied by UV-vis, 1H NMR, 2D-NOESY and MALDI-TOF MS, and it reveals that a stable 1:1 inclusion complex between TPPOC3Py and HP-beta-CD or beta-CD has formed, in which one of the meso substituents of porphyrin ring has deeply penetrated through the cavity of HP-beta-CD from secondary face. The inclusion constants of the complexes of TPPOC3Py-beta-CD and TPPOC3Py-HP-beta-CD are (1.6+/-0.2)x10(3) M-1 and (8.9+/-0.4)x10(4) M-1, respectively.