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A recyclable bolt is a kind of green supporting component that can save materials and weaken the influence of underground engineering. It has a good application prospect in foundation pit and slope-supporting engineering, as well as a high economic and environmental effect in future engineering construction. The stress and displacement change of the foundation pit with a recoverable bolt was analyzed by performing a laboratory model test. The test results demonstrated that in the process of excavation, the recyclable anchor rod supporting the structure effectively limited the horizontal displacement of the pile top and had a significant constraint effect on the surface settlement. With the increase in the excavation depth, both the axial force value of the recyclable anchor rod and the maximum bending moment value of the supporting pile increased gradually, and the maximum bending moment value of the supporting pile appeared at 1/3 H. After the excavation, the maximum horizontal displacement of the pile top was 0.04% of the excavation depth. The failure recovery of the anchor was the primary factor contributing to the increased deformation of the foundation pit during the backfilling stage. Upon completion of the backfilling process, the final deformation of the foundation pit reached 0.1% of the excavation depth; this can meet safety requirements, reduce the waste of building materials, and conform to the concept of green sustainable development. [ABSTRACT FROM AUTHOR]

In this article, different carbon materials (NC, CC) are obtained by burning two kinds of six‐carbon alkane, n‐hexane, and cyclohexane, respectively. They are used as negative electrode additives for lead‐carbon batteries (LCBs) that could considerably improve the performance of LCB cycle life. 0.1 wt% NC (0.1NC) shows the best high rate partial state of charge cycle performance (5350) which is 3.6 times of CC and 1.2 times of commercial conductive carbon black. Furthermore, in the charging acceptance test, the initial instantaneous constant voltage charging receiving current of 0.1NC is 7.81 A, which is increased by 167% compared with 0.1EC (2.92 A). The synergistic effect of high graphitization structure, small specific surface area, and abundant carboxyl functional groups may be the reason for NC's good performance. [ABSTRACT FROM AUTHOR]

Herein, a simple method to prepare porous carbon that inhibits hydrogen evolution is used, which has enormous advantages for both capacitors and lead‐acid batteries. The quantitative filter paper spongy porous carbon (SQFPC) is successfully synthesized by the two‐step method. SQFPC displays a porous, spongy structure with a large specific surface area (1847 m2 g−1). In electrochemical tests, SQFPC exhibits high specific capacitance (244 F g−1 at 1 A g−1) and a capacitance retention rate of 72.5% at 40 A g−1. In addition, the capacity of the battery with 0.5 wt% SQFPC is improved by 57.6% at a discharge rate of 0.1C, and the cycle life under the high‐rate partial state of charge is 9.3 times that of the blank battery. The enhanced battery performance is related to the unique structure and surface functional groups of carbon, which speed up ion movement inside the battery and provide active sites for lead deposition. [ABSTRACT FROM AUTHOR]

Summary: It is a very green process to recover lead resources from waste lead‐acid batteries for remanufacturing lead‐acid batteries but recovered lead oxide from waste lead‐acid battery as active electrode material often exhibits poor performance. In this paper, HRPSoC (high rate charged) cycle life can be greatly improved by adding two kinds of nanometer lead sulfate carbon composite material into the anode material prepared from recovered lead oxide powder. PbSO4/Pb@CB (PPC) and PbSO4/Pb@MC (PMC) composite material have a multistage porous/mesoporous structure to provide a reaction site of Pb deposition and to increase the electrochemical active area of lead‐carbon electrode, which improves the circulation reversibility. The resulting HRPSoC of lead‐acid battery of PPC and PMC battery is 45 957 and 6767 cycles, which are 15.5 and 2.8 times that of a blank battery (2960), respectively. The proposed research provides a promising strategy for directly using active substances of recycled lead powder for lead‐acid batteries which greatly benefit to lead resource recycling. [ABSTRACT FROM AUTHOR]

Based on the vertical cyclic model test of the cement-fly ash mixing pile (CFMP) composite foundation, the effects of different dynamic load ratios on the long-term bearing characteristics of the composite foundation were studied. From the perspectives of foundation cumulative settlement, dynamic stiffness, pile axial force, and pile lateral friction, etc., the bearing mechanism of the CFMP fly ash composite foundation under cyclic load was investigated. By virtue of the assay herein, the authors discovered that the cumulative settlement under different load ratios exhibited the "threshold effect", which could be divided into the attenuation type and destruction type. When the peak value of the cyclic load was close to the ultimate bearing capacity, the dynamic failure of the pile foundation occurred. The cyclic displacement ratio ranged from 1.05 to 1.23, satisfying the relation of quadratic equation. The cyclic load settlement could be predicted by the static load displacement. During cyclic loading, the proportion of the pile side sharing the upper load decreased persistently, and the fatigue degradation of side friction resistance occurred. The degradation could be alleviated by reducing the water content of fly ash and taking waterproof measures during construction. [ABSTRACT FROM AUTHOR]

In this work, we designed two non-salen coumarin Schiff base chiral fluorescent probes 3,3′-((1E,1′E)-(((1,2)-cyclohexane-1,2-diyl)bis(azaneylylidene))bis(methaneylylidene))bis(7-methoxy-2H-chromen-2-one) (L1) and 3,3′-((1E,1′E)-(((1,2)-cyclohexane-1,2-diyl)bis(azaneylylidene))bis-(methaneylylidene))bis(2H-chromen-2-one) (L2), which have outstanding circular dichroic CD signals but almost show no circularly polarized luminescence (CPL) signals. By adding metal ions that can effectively inhibit photo-induced electron transfer (PET), it was observed that L1 can be used as a highly sensitive dual detection ion probe for Mg2+ and Zn2+ as Mg2+ and Zn2+ can turn on the CPL emission of L1. Moreover, (S,S)-L1 has exquisite recognition ability for the enantiomer of the chiral drug D / L -camphorsulfonate and showed reversible fluorescence "on/off" response with Zn2+ and EDTA. It was also found that L2 manifested selective recognition ability for Zn2+. [ABSTRACT FROM AUTHOR]

Cement-fly ash mixture has been commonly used for the foundation treatment projects in the fly ash stratum, as it is effective in improving foundation bearing capacity and reducing settlement of stratum. In order to figure out the effect of dynamic and static load on the mechanical properties exhibited by the cement-fly ash and the reaction mechanism of cement-fly ash, a combination of the unconfined compressive test, impact test, scanning electron microscopy (SEM), and X-ray diffraction (XRD) method was adopted in this study to investigate the cement-fly ash test samples. As demonstrated by the results, the observed growth rate of 0–60 days (d) is higher than that in the later stages and the typical stress-strain curve can be divided into six sections under the unconfined compressive test. At the gas pressure of 0.2 MPa, the cement-fly ash samples exhibited obvious plastic properties in early curing time (0–60 d), and brittle failure was observed in the final stage (90 d). It is obvious that the value of dynamic compressive strength (DCS) is higher than that of unconfined compressive strength (UCS). The analysis of XRD has revealed that the hydration products are primarily derived from the hydration reaction of cement in the early stage and the pozzolanic reaction in the late stage. The pores of cement-fly ash are found to be filled with the hydration products, despite the presence of a mass of pores in the interior. [ABSTRACT FROM AUTHOR]

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In this work, we designed two non-salen coumarin Schiff base chiral fluorescent probes 3,3′-((1E,1′E)-(((1,2)-cyclohexane-1,2-diyl)bis(azaneylylidene))bis(methaneylylidene))bis(7-methoxy-2H-chromen-2-one) (L1) and 3,3′-((1E,1′E)-(((1,2)-cyclohexane-1,2-diyl)bis(azaneylylidene))bis-(methaneylylidene))bis(2H-chromen-2-one) (L2), which have outstanding circular dichroic CD signals but almost show no circularly polarized luminescence (CPL) signals. By adding metal ions that can effectively inhibit photo-induced electron transfer (PET), it was observed that L1 can be used as a highly sensitive dual detection ion probe for Mg2+ and Zn2+ as Mg2+ and Zn2+ can turn on the CPL emission of L1. Moreover, (S,S)-L1 has exquisite recognition ability for the enantiomer of the chiral drug D / L -camphorsulfonate and showed reversible fluorescence "on/off" response with Zn2+ and EDTA. It was also found that L2 manifested selective recognition ability for Zn2+. [ABSTRACT FROM AUTHOR]

Tibet is environment-ecologically vulnerable with very weak self-adjustment ability, thus risk control of Tibet herb residue (THR) through environment-sustainable disposal is in urgent need. Gasification is an effective way to dispose THR with product gas, which could meet the energy demand of local users. In this paper, gasification of THR was performed in TG-MS and a tube furnace. Effects of operating temperature and air equivalence ratio (ER) were investigated both in plain and Tibet conditions. TG-MS curves indicated most syngas were produced at 250–380 °C, and the reactions were slow down under Tibetan atmosphere. Gasification results indicated the optimum LHV gas of 5.59 MJ m−3, cold gas efficiency of 63.22% and carbon conversion efficiency of 68.87% were obtained when ER = 0.24 at 1000 °C under Tibetan pressure. LHV gas was low in Tibetan pressure which only reach 47% of that under plain condition when ER = 0.28. Results can provide insights into using gasification for treating THR and even other wastes environment-sustainably in Tibet. Image 1 • Gasification and TG-MS of Tibetan herb residue were conducted in Tibet atmosphere. • LHV of producing gas reached 5.59 MJ m−3 with equivalence ratio of 0.24 at 1000 °C. • LHV of gas in Tibetan pressure only reach 47% of the plain condition when ER = 0.28. • Herb residue gasification is considered an environment-sustainable option in Tibet. [ABSTRACT FROM AUTHOR]

Due to the utilization of landfill technology and geothermal energy production in Tibet, the contamination of the soils and underground water by trace element has currently become a serious problem, both ecologically and to the human health point of view. However, relevant studies concerning this critical problem, particularly in the Tibet area has not been found. Therefore, this study investigated the soil contamination and the spatial distribution of the trace elements in the areas surrounding the Tibetan landfill sites (LS) and geothermal sites (GS) through several pollution evaluation models. In addition, the possible sources of trace elements and their potential impact on public health were also investigated. Results showed that the trace elements in soils nearby LS and GS had moderate to high contamination risk. In soils surrounding LS, mercury had the highest concentration of 0.015 mg/kg and was 6 times higher than the background value of 0.008 mg/kg while in GS, arsenic had the highest concentration of 66.55 mg/kg, and exceeded the soil contamination risk value of 25 mg/kg. Maizhokunggar LS was the most polluted site with an average pollution load index value of 2.95 compared to Naqu, Nyingchi, Shigatse, and Lhasa. 42% of LS were with considerable ecological risk, and all GS had low ecological risk. Both carcinogenic and non-carcinogenic risk for children and adults (male, female) were within the acceptable range. According to the source analysis, unscientific anthropogenic activities including accumulated MSW, industrial discharges, and vehicle emissions significantly contributed 51.83% to soil trace element contamination. Considering that Tibet is an environment-ecologically vulnerable region with very weak self-adjustment ability, accumulated municipal solid waste in the landfill sites should be well disposed of, and even soil remediation should be well implemented. Unlabelled Image • Trace elements in Tibet landfill soil were with moderate to high contamination risk. • Hg, As were separately the most polluted elements in landfill and geothermal sites. • 42% of landfill sites were with considerable ecological risk. • Health risks of trace element pollution were within the acceptable range. • MSW, industrial discharges, vehicle emissions contributed 51.83% to soil pollution. [ABSTRACT FROM AUTHOR]