In this paper a small sag-to-span ratio conductor, belonging to overhead power transmission conductors, is studied. The single conductor is assumed to withstand a prescribed motion at a single ...conductor ends caused by suspended insulator swing and placed in the simultaneous wind and rain condition. It is modeled as a planar, nonlinear, one-dimensional continuum, and its ends are assumed to undergo the suspended insulator swing of given amplitude and frequency. Raindrops are blowing by uniformed wind flow, hitting the single conductor and may form rivulets on its surface. Besides rain-wind flow induces aerodynamic instability, the motions of the suspended insulator swing contribute to external and parametric excitation. Vertical motion equation of the single conductor is discretized with Galerkin method of which first order in-plane symmetric mode is took as trial function. Multiple-scale perturbation technique and computation methods are introduced to study nonlinear dynamic responses of the single conductor under parametric excitation or force excitation, or both excitations. Effects of key parameters, such as total damping ratio, upper rivulet angle, suspended insulator swing amplitude and frequency on dynamic characteristics of the single conductor are discussed. The results indicated that those key-parameters have obviously affected the dynamic characteristics of high-voltage conductor.
Antibiotic resistance genes (ARGs) in urban rivers are a serious public health concern in regions with poorly planned, rapid development. To gain insights into the predominant factors affecting the ...fate of ARGs in a highly polluted urban river in eastern China, a total of 285 ARGs, microbial communities, and 20 physicochemical parameters were analyzed for 17 sites. A total of 258 unique ARGs were detected using high-throughput qPCR, and the absolute abundance of total ARGs was positively correlated with total organic carbon and total dissolved nitrogen concentrations (
P
< 0.01). ARG abundance and diversity were greatly altered by microbial community structure. Variation partitioning analysis showed that the combined effects of multiple factors contributed to the profile and dissemination of ARGs, and variation of microbial communities was the major factor affecting the distribution of ARGs. The disparate distribution of some bacteria, including
Bacteroides
from mammalian gastrointestinal flora,
Burkholderia
from zoonotic infectious diseases, and
Zoogloea
from wastewater treatment, indicates that the urban river was strongly influenced by point-source pollution. Results imply that microbial community shifts caused by changes in water quality may lead to the spread of ARGs, and point-source pollution in urban rivers requires greater attention to control the transfer of ARGs between environmental bacteria and pathogens.
The 14th Five-Year Plan stated that China should accelerate green development and promote a comprehensive green transition in economic and social development. As China's economic growth slows, green ...development becomes greatly significant for the high-quality development of the economy. Based on China's provincial panel data from 2005 to 2021, this study applies fixed effects model and mediating effect model to explore the influence of the government environmental investment on green development. The results indicate that (1) the government environmental investment was conducive to green development, but such effect weakened with time. (2) The government environmental investment indirectly promoted green development through the application of green patents and economic agglomeration. (3) The promotional effect of the government environmental investment varied according to region and time. Specifically, investment exerted the most significant effect on the green development of eastern China, which became more evident after 2015. The government should promote green development by implementing long-term assessment and accountability mechanisms, expanding the scale of economic agglomeration, improving the efficiency of the application of green patents, and improving the accuracy of environmental investment.
Collision of two kinks with inner structure Zhong, Yuan; Du, Xiao-Long; Jiang, Zhou-Chao ...
The journal of high energy physics,
02/2020, Letnik:
2020, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A
bstract
In this work, we study kink collisions in a scalar field model with scalar-kinetic coupling. This model supports kink/antikink solutions with inner structure in the energy density. The ...collision of two such kinks is simulated by using the Fourier spectral method. We numerically calculate how the critical velocity and the widths of the first three two bounce windows vary with the model parameters. After that, we report some interesting collision results including two-bion escape final states, kink-bion-antikink intermediate states and kink or antikink intertwined final states. These results show that kinks with inner structure in the energy density have similar properties as those of the double kinks.
Thrust wedges are common in nature, but not all of their origins can be properly explained by the classic Coulomb wedge theory, which considers only a 2D perspective. A few analogue models, however, ...revealed that lateral shear stress (inherent in both analogue models and nature) may strongly affect the development of thrust wedges and the lateral/basal shear stress (τs/τd) ratio might have controlled the structural vergence of thrust wedge, suggesting that origin of thrust wedges needs to be considered from a 3D perspective. The origin of the Eastern Sichuan–Xuefeng fold‐thrust belt (ESXFTB), which is characterized by two oppositely vergent thrust systems at different crustal levels and may contain another large purely backward‐vergent thrust wedge on the world, is still problematic. Revealing the relationship between τs/τd ratio and structural vergence may prompt a deep understanding of the origin of thrust wedges as well as the ESXFTB. This relationship, however, is still not very clear due to the lack of systematic experiments. For these reasons, we performed systematic experiments of two types of analogue models under different τs/τd ratios. Our model results revealed, for the first time, that structural vergence of thrust wedges lying on a weak décollement may progressively change from frontward (when τs/τd <0.09) to dual (when τs/τd = 0.09–1.15) and then to backward (when τs/τd >1.15) and the two oppositely vergent thrust systems in the ESXFTB can be produced simultaneously by the single northwestward Mesozoic shortening probably due to their apparently different τs/τd ratios.
Key Points
Structural vergence of thrust wedges may change progressively with the increase of lateral/basal shear stress (τs/τd) ratio
Under the condition of one weak décollement, frontward, dual and backward vergence occurred when τs/τd <0.09, = 0.09–1.15 and >1.15, respectively
ESXFTB can be a product of the single northwestward Mesozoic shortening because their two thrust systems have different τs/τd ratios
Hot compression experiments of a Ti55511 titanium alloy are conducted to study the phase transformation characteristics and dynamic recrystallization (DRX) behavior. It is found that the fraction of ...α phase decreases with increasing the strain rate or deformation amount. Meanwhile, the original lamellar α phases easily transform into the spheroidal and bulk α phases at larger deformation amounts or higher strain rates. Most of α phases disappear and the final microstructures are mainly β phases when the temperature is over 800 °C. The DRX degree rises with raising the deformation amount or decreasing the strain rate. However, the DRX behavior becomes weaken with raising the deformation temperature. α phases are evenly distributed around β phases during hot compressive deformation, which not only restrains the growth of β phases but also promotes the DRX process of β phases. In addition, the geometric DRX takes place within α phases, while the continuous DRX occurs within β phases during the hot compression.
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•Phase transformation and dynamic recrystallization (DRX) behavior of a Ti55511 titanium alloy are studied.•The volume fraction of α phase decreases with increasing the strain rate or deformation degree.•Initial lamellar α phases easily transforms into bulk/spheroidal α phases at the larger strains or higher strain rates.•The α phases not only restrains the growth of β phase, but also promotes the DRX process of β phase.•The geometric DRX takes place within α phases, while the continuous DRX occurs within β phases.
Quantum key distribution provides secure keys resistant to code-breaking quantum computers. The continuous-variable version of quantum key distribution offers the advantages of higher secret key ...rates in metropolitan areas, as well as the use of standard telecom components that can operate at room temperature. However, the transmission distance of these systems (compared with discrete-variable systems) are currently limited and considered unsuitable for long-distance distribution. Herein, we report the experimental results of long distance continuous-variable quantum key distribution over 202.81 km of ultralow-loss optical fiber by suitably controlling the excess noise and employing highly efficient reconciliation procedures. This record-breaking implementation of the continuous-variable quantum key distribution doubles the previous distance record and shows the road for long-distance and large-scale secure quantum key distribution using room-temperature standard telecom components.
China's pilot carbon trading policy is expected to be both efficient and flexible in reducing carbon emissions through incentivising low-carbon innovation. This paper analyses the effects of this ...pilot policy on low-carbon innovation using a difference-in-difference model, based on a sample of selected enterprises and carrying out a series of robustness tests to corroborate the results. The analysis shows that the pilot carbon trading policy is predicted to have a significantly positive effect on the low-carbon innovation of enterprises that fall under its scope, notably by alleviating obstacles to the financing of low-carbon innovation. Furthermore, a heterogeneity analysis of enterprises' characteristics and carbon allowance allocation methods in different pilots indicates that the effect of the pilot carbon trading policy on enterprises' low-carbon innovation will be reflected mainly in enterprises in China's eastern provinces, and in state-owned enterprises. Compared with the grandfathering and historical intensity allocation methods, the findings of this study suggest that the extent of low-carbon innovation is significantly greater when the benchmarking method is used. The results of this paper offer some key insights into improving the policy design of a nationwide carbon trading market in China, as well as a reference point for other countries and regions, especially developing countries, in establishing a carbon trading market.
Key policy insights
China's pilot carbon trading policy can promote low-carbon innovation.
Easing the financing constraints of enterprises can promote low-carbon innovation.
Compared with the grandfathering and historical intensity allocation methods, using the benchmarking method significantly improves the enterprises' low-carbon innovation.
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•Polystyrene-nanoplastics (PS-NPs) enhance antioxidant activity and activate carbon metabolism.•The difference in root-related gene expressions is induced by PS-NPs.•Jasmonate and ...lignin biosynthesis are inhibited by PS-NPs treatments.•Exogenous JA application alleviates potential adverse effects of PS-NPs on rice seedlings.
Potential adverse effects of nanoplastics (NPs) on marine organisms have received increased attention in recent years. In contrast, few data are available on terrestrial plants, especially on the mechanisms for transport of NPs in plants and phytotoxicity (at both phenotypic and molecular levels) of plants induced by NPs. To address this knowledge gap, we conducted a microcosm study in which hydroponically-cultured rice (Oryza sativa L.) seedlings were exposed to polystyrene (PS)-NPs at 0, 10, 50, and 100 mg L−1 for 16 d and examined for morphological and physiological phenotypes and transcriptomics. Laser confocal scanning micrographs confirmed PS-NPs were uptaken by rice roots, greatly benefitted from the transport activity of aquaporin in rice roots. The significant enhancement (p < 0.05) of antioxidant enzyme activities reflected the oxidative stress response of rice roots upon exposure to PS-NPs. Treatment by PS-NPs decreased root length and increased lateral root numbers. Carbon metabolism was activated (e.g., increased carbon and soluble sugar contents) whereas jasmonic acid and lignin biosynthesis were inhibited. The present study demonstrated the likelihood for transport of PS-NPs in rice roots and induced phytotoxicity by PS-NPs, which should inspire further investigations into the potential human health risks from rice consumption.
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