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Abstract In order to promote the engineering application of recycled concrete, the effects of PPF and nano-TiO2 dioxide on the mechanical properties and durability of recycled concrete were studied. Polypropylene fiber recycled concrete(PRAC) and nano-TiO2 recycled concrete(TRAC) were prepared by adding different volume contents of PPF and nano-TiO2. The experimental findings demonstrated that the PPF and nano-TiO2 improved the splitting tensile strength of RAC better than the compressive strength. When the volume content of nano-TiO2. and PPF is 0.8% and 1.0%, respectively, the corresponding splitting tensile strength of concrete reaches the maximum value(3.4 and 3.7 MPa). The contribution rates of nano-TiO2 and PPF with different volume contents to the mechanical properties of RAC have optimal values, which are 0.4 and 1.0%, respectively. The incorporation of nano-TiO2 and PPF can effectively inhibit the loss of RAC mass and the generation of pores under freeze–thaw conditions, and slow down the decrease of dynamic elastic modulus. When the volume content of PPF is 1.0% and the volume content of nano-TiO2 is 0.4%, the protection effect on the internal structure of RAC is better, and its carbon resistance is better. The results of RSM model analysis and prediction show that both PPF and nano-TiO2 can be used as admixture materials to improve the mechanical properties and durability of RAC, and the comprehensive improvement effect of PPF on RAC performance is better than that of nano-TiO2.

[Objective] In order to investigate the influencing factors and variation rules of accuracy of various two-step models of 3D mapping methods. [Methods] Soil organic carbon in a forest with an area of about 5 km2 in a typical hilly region of South China was mapped. Spline functions, exponential functions and power functions were used as depth functions, ordinary kriging and random forest were used as horizontal mapping methods and two different mapping forms (called forms A and B) were used. The 3D prediction mapping of soil organic carbon was carried out, and the influence of different depth functions, horizontal mapping methods and mapping forms on the 3D mapping results of two-step model was explored. [Results] (1) The depth function largely determined the variation of mapping results in vertical and horizontal directions, which showed that the variation of the mapping results was significantly different among the three depth functions. Exponential function had the largest variation and power function had the weakest variation, while horizontal mapping methods (ie.ordinary kriging and random forest) had little influence on the vertical variation of mapping results. However, the spatial variation of surface layer was greatly affected by the horizontal mapping methods. (2) The accuracy of spline function was the best because the simulated depth curve was in the best agreement with the measured values. The consistency correlation coefficients (CCC) of the 3D mapping based on the spline function were 0.72 and 0.75, which were higher than the other functions in the same form of 3D mapping (CCC were between 0.64 and 0.74). For the horizontal mapping methods, the accuracy of the ordinary kriging was better than that of the random forest, the CCC of the former was between 0.67 and 0.75, the latter was between 0.64 and 0.72; (3) The two mapping forms of the two-step model had little influence on accuracy. Only in the case of prediction for bottom layer, form A (i.e., horizontally mapping simulated walues of a depth function was better than form B (i.e., simulating parameters of a depth function).(4) Among all 3D mapping methods, the form A, with ordinary kriging and spline functions, had the highest accuracy, generating coefficient of determination (R2) of 0.76, CCC of 0.75, and root mean square error (RMSE) of 3.50 g/kg. [Conclusion] In the two-step model of 3D soil mapping, firstly, the spline function should be considered as the depth function. Secondly, the horizontal mapping method should be considered according to the landscape conditions and sample size. Finally, the first mapping form of the two-step model should be adopted as far as possible.

Oversized coal blocks can easily cause poor coal flow, blockage, and coal stacking when transported on a belt conveyor. However, the differences in appearance and color between large coal blocks and ordinary coal blocks are small, and there are obstructions and stacking between coal blocks. Existing coal block detection methods are not precise enough to distinguish between large coal blocks and ordinary coal blocks, which can easily lead to missed or false detections. In order to solve the above problems, a modified YOLOv5 model is proposed for detecting large coal blocks in belt conveyors. The model uses parallel dilated convolution modules to replace some ordinary convolution modules in the YOLOv5 backbone network. It expands the receptive field, improves multi-scale feature learning capability, and better distinguishes large coal blocks from ordinary coal blocks. The joint attention module is added to the neck network to better integrate contextual information and improve the positioning capability for large coal blocks. The model uses the trained improved YOLOv5 model to detect real-time coal transportation videos captured by the camera, and links PLC alarms in real-time based on the quantity information of large coal blocks. The experimental results show that compared to the original YOLOv5 model, the improved YOLOv5 model has improved recall and average precision by 3.4% and 2.0%, respectively. PLC can operate corresponding indicator lights and buzzers to alert based on the quantity of large coal blocks detected by the improved YOLOv5 model. The improved YOLOv5 model is applied to actual coal transportation videos in coal mines, with a detection precision of 97.0% for large coal blocks, effectively avoiding missed and false detections.

Objective To investigate the protective effect of Dexmedetomidine (Dex) on the colon and spinal cord of irritable bowel syndrome (IBS) rats with chronic functional visceral pain, and its underlying mechanism of its effects on phosphorylation of extraeellular signal regulated kinase 1 (ERK1) and cyclic adenosine monophosphate response element binding protein (CREB). Methods Forty SPF-grade male SD rats (6~8 g) were inflicted with colorectal dilatation (CRD) stimulation to establish a rat model of irritable bowel syndrome (IBS). Then the animals were divided into normal group, model group, Dex group and Dex+pc group. The rats from the normal group do not do any treatment, and those of the model group, Dex group and Dex+pc group received CRD stimulation. After successful modeling, the rats in the Dex group were injected intraperitoneally with 5 μg/kg Dex hydrochloride injection daily, and those in the Dextpc group were injected intraperitoneally with 5 μg/kg Dex hydrochloride daily, as well as pc DNA3.1-CREB. The rats in the control group and model group were injected intraperitoneally with the same dose of normal saline and 100 nmol/L of pc DNA3.1-CREB-NC. TUNEL assay was used to detect cell apoptosis, real-time quantitative polymerase chain reaction (RT-qPCR) was employed to detect the mRNA expression of ERK1 and CREB, and Western blotting was used to detect the expression of p-ERK1 and p-CREB in rat spinal cord tissues. Results Compared with the normal group, the cell apoptotic rate, mRNA levels of ERK1 and CREB, and expression of p-ERK1 and p-CREB in spinal cord tissues were significantly increased in the model, Dex and Dex+pc groups (P < 0.05). The Dex group and Dex+pc group had obviously lower apoptotic rate, decreased ERK1 and CREB expression at mRNA level, and reduced expression of p-ERK1 and p-CREB than the model group (P < 0.05). What's more, apoptotic rate, mRNA expression of ERK1 and CREB, and protein expression of p-ERK1 and p-CREB were notably higher in the Dex+pc group than the Dex group (P < 0.05). Conclusion Dex can significantly inhibits the apoptosis in spinal cord tissue of rats with chronic functional visceral pain. It may play a protective role in colon and spinal cord tissues by inhibiting the phosphorylation of ERK1 and CREB.

To advance the use of industrial solid waste and recycled concrete, this study explores the impact of fly ash and slag powder on the mechanical properties, freeze–thaw resistance, and carbonation resistance of manufactured sand recycled aggregate concrete (MRAC). Different FSMRAC (Fly Ash and Slag Powder MRAC) mixtures were prepared by varying the amounts of fly ash and slag powder. The results show that fly ash and slag powder enhance the splitting tensile strength of MRAC more than its compressive strength. when the contents of fly ash and slag powder are 0% and 30%, respectively, the FSMRAC attains maximum compressive strength of 48.6 MPa and splitting tensile strength of 3.8 MPa, representing increases of 2.96% and 5.6% in compressive and splitting tensile strengths, respectively, compared to MRAC. A total addition of 30% fly ash and slag powder effectively reduces the loss of mechanical properties under freeze–thaw conditions. When the fly ash-to-slag powder ratio (F:S) exceeds 1.5, it improves carbonation resistance and compressive strength; when the ratio is below 1.5, it enhances splitting tensile strength resistance to freeze–thaw cycles. Slag powder promotes hydration and improves mechanical properties, while fly ash densifies the concrete matrix and lowers the carbonation rate. Response Surface Methodology (RSM) analysis indicates that both materials improve MRAC’s properties. Higher fly ash content benefits compressive strength and carbonation resistance, while higher slag powder content improves splitting tensile strength.

The tower foundation is an important component of the tower grounding device. The conditions in permafrost areas are relatively harsh, and damage to the foundation can affect the grounding performance of the grounding device. However, the damage characteristics of permafrost to the tower foundation in permafrost areas are not yet clear, and effective protection of the foundation cannot be achieved. Based on this, this article constructs a simulated frozen soil experimental platform through experiments, replacing the tower foundation with concrete specimens. The electrical and mechanical properties after freeze-thaw were measured using the quadrupole method and resonance method, respectively. The self performance of the tower foundation under different moisture content freeze-thaw conditions was studied, and the performance change law of the tower foundation after freeze-thaw was obtained to explore the damage of frozen soil to the tower foundation in frozen soil areas. It can be considered that the frozen soil in permafrost areas does not cause significant damage to the tower foundation itself in a limited number of years.

Effect of isocitr ate dehydrogenase 1 (IDH1) mutation in neovascularization might be linked with tissue perfusion in gliomas. At present, the need of injection of contrast agent and the increasing scanning time limit the application of perfusion techniques. We used a simplified intravoxel incoherent motion (IVIM)-derived perfusion fraction (SPF) calculated from diffusion-weighted imaging (DWI) using only three b-values to quantitatively assess IDH1-linked tissue perfusion changes in WHO grade II-III gliomas (LGGs). Additionally, by comparing accuracy with dynamic contrast-enhanced (DCE) and full IVIM MRI, we tried to find the optimal imaging markers to predict IDH1 mutation status.

Compared to other soil remediation technologies, Cd-contaminated farmland soil with low cadmium accumulation (LCA) plant-based safe utilization is more catered to developing countries with food in high demand. Hormesis, which describes the fortification of plant growth performance by a low level of environmental stress, can be innovatively used to achieve increases in crop yield and plant functional components, thus amplifying the safe utilization efficiency of low Cd-contaminated soil by LCA plants. In the present study, the growth and physiological responses of Polygonatum sibiricum, a traditional Chinese medicinal herb, were investigated under laboratory conditions of gradient Cd dosage concentrations and times. As a result, the growth performance of P. sibiricum reached the peak of an inverse U-shaped curve of hormesis under e0 mg kg−1 and 9 months of Cd stress, with elevations in tuber biomass (medicinal part), plant height and polysaccharide content (medicinal components) of 143%, 25% and 90%, respectively. Meanwhile, trace Cd accumulation (0.41 mg kg−1) in the tuber guaranteed medicinal edible safety. In addition, Cd-induced hormesis in P. sibiricum was verified to be overcompensated by antioxidation systems. In conclusion, such ‘win-win’ results, including low Cd accumulation and enhancement of plant pharmaceutical value, provided medicinal herbs with a possibility for safe soil utilization.

With the development of smart distribution technology in the future, electric vehicle users can not only charge reasonably based on peak-valley price, they can also discharge electricity into the power grid to realize their economic benefit when it’s necessary and thus promote peak load shifting. According to the characteristic that future electric vehicles can discharge, this paper studies the interactive characteristics between electric vehicles and smart grid. In this paper, the example shows that the charging and discharging behaviour of EV users will bring significant fluctuation effect to the power grid load, and the reasonable TOU strategy can stimulate EV users to conduct reasonable charging and discharging, so as to smooth the peak and valley difference of some power grid.

The existing evaluation system of scientific and technological talents is insufficient in classification and evaluation, lacks clear evaluation objectives and evaluation standards, and attaches too much importance to the achievements of scientific and technological talents and lacks the development potential of scientific and technological talents. In this paper, using intelligent era information technology reform of science and technology talent assessment system, to advocate and innovation for the purpose, classification of evaluation objects, evaluation criterion of explicit, the diversification of evaluation subject, evaluation method is scientific, the diversification of evaluation methods, to effectively identify innovative science and technology talents, motivating talents of science and technology innovation power and guide the scientific and technological personnel work to lay the foundation.

The technological breakthrough of energy storage and the rapid decrease in cost make the application prospect of energy storage in power system more and more extensive, and will play an increasingly important role in the safe and efficient operation of power system. The optimal arrangement of energy storage load operation is conducive to the maximization of economic profit on the grid side, which is of great significance to the satisfaction of power demand of the distribution network.