•The anti-rutting efforts focus on improving the rheological properties of asphalt.•Semi-flexible and cool asphalt pavements can help reduce rutting depth.•The applicability of wheel tracking test ...was systematically analyzed.•It is unnecessary to perform rutting tests at a rather high temperature.•Multiple-stress mode should be considered in performing laboratory rutting test.
Permanent deformation, mainly referring to rutting, is one of the main distress modes of asphalt pavement. Exploring effective methods to mitigate the rutting distress is of great significance for providing a long-life and safe road. The rutting solutions were first reviewed. It was found that the efforts from academic and engineering industries focused on enhancing the rheological properties of asphalt binder by adding modifying powder, fiber or mixture into binder or mixture, as well as strengthening aggregate interlock and applying novel pavement structure. Semi-flexible asphalt pavement was suggested to be a promising method to fight the rutting distress, because it has a high mechanical property without scarifying the flexibility of asphalt pavement. In order to consider the influence of temperature on rutting occurrence, cool asphalt pavements, especially heat-transfer induced structures, were reviewed and deemed to be a new strategy for reducing rutting susceptibility of asphalt pavement. In order to evaluate the effectiveness of above rutting solutions, many tests, such as multi-stress creep recovery test for asphalt binder and wheel tracking test for asphalt mixture, were reviewed. By linking the reported results of wheel tracking test with high-temperature rutting mechanism it was advised to develop a test method that could reproduce the real field pavement environment, including multiple stress mode, temperature gradient control system and pavement structure, to assess the rutting response of asphalt mixture. This review is expected to provide an overall insight on the existing rutting solutions and test methods, and recommend future studying areas relevant to rutting distress.
A
bstract
We generalize Integration-By-Parts (IBP) and differential equations methods to de Sitter correlators related to inflation. While massive correlators in de Sitter spacetime are usually ...regarded as highly intricate, we find they have remarkably hidden concise structures from the perspective of IBP. We find the factorization of the IBP relations of each vertex integral family corresponding to d
τ
i
integration. Furthermore, with a smart construction of master integrals, the universal formulas for iterative reduction and d log-form differential equations of arbitrary vertex integral family are presented and proved. These formulas dominate all tree-level de Sitter correlators and play a kernel role at the loop-level as well.
A
bstract
In this paper, we develop an iterative sector-level reduction strategy for Feynman integrals, which bases on module intersection in the Baikov representation and auxiliary vector for tensor ...structure. Using this strategy we have studied the reduction of general one-loop integrals, i.e., integrals having arbitrary tensor structures and arbitrary power for propagators. Inspired by these studies, a uniform and compact formula that iteratively reduces all one-loop integrals has been written down, where messy polynomials in integration-by-parts (IBP) relations have organized themselves to Gram determinants.
•Steel fiber was used to prepare high-thermal-conductivity asphalt mixture.•Steel fiber could increase the air voids content of asphalt mixture.•Greater compaction work could induce a lower air voids ...content of asphalt mixture.•Using steel fiber asphalt mixture could reduce the temperature of asphalt pavement.
High-temperature asphalt pavements will intensify urban heat island effect and cause many pavement distresses. In order to cool asphalt pavement, two types of steel fiber, curved hook steel fiber (CH-SF) and long sawtooth steel fiber (LS-SF), were used to increase the thermal conductivity of asphalt mixture. The results show that the addition of steel fiber increased the air voids content of asphalt mixture, of which CH-SF had a stronger influence. Six compaction levels were used to investigate the compaction characteristic of steel fiber asphalt mixture. It is found that greater compaction work would induce the mixtures to be further compacted. When the steel fiber asphalt mixtures were compacted to have an air voids content of about 4.0%, CH-SF was more effective to increase the thermal conductivity and splitting strength of asphalt mixture than LS-SF. The indoor irradiation test shows that using 1.0% CH-SF asphalt mixture below the top asphalt layer could reduce the temperature at the depth of 4 cm by 1.8 ℃. The findings in this study indicate that using CH-SF can increase the thermal conductivity of asphalt mixture, on the condition that the CH-SF asphalt mixture is compacted to have an appropriate air voids content.
It is anticipated that a considerably higher network capacity will be achieved by the fifth generation (5G) small cell networks incorporated with the millimeter wave (mm-wave) technology. However, ...the mm-wave signals are more sensitive to blockages than signals in lower frequency bands, which highlight the effect of anisotropic path loss in network coverage. According to the fractal characteristics of cellular coverage, a multi-directional path loss model is proposed for the 5G small cell networks, where different directions are subject to different path loss exponents. Furthermore, the coverage probability, association probability, and the handoff probability are derived for the 5G fractal small cell networks based on the proposed multi-directional path loss model. The numerical results indicate that the coverage probability with the multi-directional path loss model is less than that with the isotropic path loss model, and the association probability with long link distance, e.g. , 150m, increases obviously with the increase of the effect of anisotropic path loss in 5G fractal small cell networks. Moreover, it is observed that the anisotropic propagation environment is having a profound impact on the handoff performance. Meanwhile, we could conclude that the resulting heavy handoff overhead is emerging as a new challenge for 5G fractal small cell networks.
Canonical Feynman integrals are of great interest in the study of scattering amplitudes at the multi-loop level. We propose to construct dlog-form integrals of the hypergeometric type, treat them as ...a representation of Feynman integrals, and project them into master integrals using intersection theory. This provides a constructive way to build canonical master integrals whose differential equations can be solved easily. We use our method to investigate both the maximally cut integrals and the uncut ones at one and two loops, and demonstrate its applicability in problems with multiple scales.
Wearable and portable devices with desirable flexibility, operational safety, and long cruising time, are in urgent demand for applications in wireless communications, multifunctional entertainments, ...personal healthcare monitoring, etc. Herein, a monolithically integrated self‐powered smart sensor system with printed interconnects, printed gas sensor for ethanol and acetone detection, and printable supercapacitors and embedded solar cells as energy sources, is successfully demonstrated in a wearable wristband fashion by utilizing inkjet printing as a proof‐of‐concept. In such a “wearable wristband”, the harvested solar energy can either directly drive the sensor and power up a light‐emitting diode as a warning signal, or can be stored in the supercapacitors in a standby mode, and the energy released from supercapacitors can compensate the intermittency of light illumination. To the best of our knowledge, the demonstration of such a self‐powered sensor system integrated onto a single piece of flexible substrate in a printable and additive manner has not previously been reported. Particularly, the printable supercapacitors deliver an areal capacitance of 12.9 mF cm−2 and the printed SnO2 gas sensor shows remarkable detection sensitivity under room temperature. The printable strategies for device fabrication and system integration developed here show great potency for scalable and facile fabrication of a variety of wearable devices.
A monolithically integrated self‐powered smart sensor system with printed interconnects, printed gas sensor for ethanol/acetone detection, printable supercapacitors, and embedded solar cells as energy sources, is successfully demonstrated in a wristband fashion using additive inkjet printing technique. To realize printable fabrication of the integrated system, different functional nanoparticles are synthesized and prepared into stable inks with modified solvent systems.
In arid and semi‐arid areas, local precipitation is insufficient to fulfil the water requirements of the fragile local environment; hence, water is obtained from groundwater. The Hulun Lake Basin is ...located in the Mongolian Plateau, which is home to numerous lakes. In this study, we used remote sensing and isotopic tracing of naturally occurring isotopes (δ18O, δ2H, and 87Sr/86Sr) to identify and quantify the various water inputs into the basin. Based on the lake water balance calculation and precipitation and river inputs, a 5.4 × 108 m3/year groundwater recharge rate was determined. Groundwater and river water with depleted δ18O and δ2H were identified close to the faults near Hulun Lake. The groundwater recharge into Hulun Lake is aided by the faults. The δ18O and δ2H compositions of the groundwater, rivers, and lakes were consistent and more depleted than those of precipitation in the local mountains and plains. Therefore, the rivers and lakes are assumed to be primarily recharged by groundwater. The low strontium isotopes (87Sr/86Sr) in the samples suggest that the water was primarily recharged by basalt groundwater, which was identified under the Cenozoic strata instead of the sandstones, granites, and tuffs, which are the primary rocks in the study area. Moreover, the faults were widely distributed in the study area, allowing for groundwater upwelling from basalts. For the areas with volcanic rocks and faults, particularly in arid and semi‐arid areas, the basalt groundwater recharge through faults is critical for environmental sustainability. This research provides necessary information for future hydro‐ecosystem resource management in arid and semi‐arid areas.
Hulun Lake is recharged by groundwater at a rate of 5.4 × 108 m3/year. Waters with depleted δ18O and δ2H occur close to faults near Hulun Lake. Low 87Sr/86Sr suggests the groundwater is primarily recharged from basalts.
Allelopathy has been demonstrated to be an environmentally friendly way to control harmful algal blooms. Allelochemicals of submerged plants have attracted extensive research due to their ...bioavailability. The dose-response of submerged plant extracts on algae growth is worth further study to improve the efficiency of bioremediation. In this study, the ultrasonic-enzymatic assistance method was utilized to extract allelochemicals from Ceratophyllum, Myriophyllum spicatum, and Vallisneria. The effects of low-dosage and high-dosage extracts on the growth of Microcystis aeruginosa were compared based on cell biomass and morphology, photosynthetic parameters, reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels. The results showed that the three submerged plant extracts exhibited hormetic effects at low dosages and inhibitory effects at high dosages on algal growth. Within 48 h of cultivation, the enzymatic activities of Microcystis aeruginosa fluctuated, suggesting that the extracts of the three submerged plants induced different oxidative reactions. After 120 h of cultivation with high-dosage extracts, the physiological and biochemical reactions of Microcystis aeruginosa significantly decreased, indicating the effectiveness of the allelopathy of Ceratophyllum, Myriophyllum spicatum, and Vallisneria extracts in controlling algal blooms. The phenomenon of hormesis and inhibition effect confirmed a significant dose-response relationship between the allelochemicals of submerged plant extracts and Microcystis aeruginosa, which could be attributed to the composition and content of allelochemicals. These findings highlight the importance of the relative concentration of the biological algaecide and will benefit other researchers in determining the safe dosage of plant allelochemicals when used in water.
PDF
