The working mechanism of suggested tunable bandstop filtered with asymmetrical multiple‐mode resonator equipped with tree‐shape branches is described in this letter. Because of the established degree ...of freedom, the suggested bandstop filters’ (BSFs) centre frequencies may be modified based on the design approach. Meanwhile, the suggested BSFs have small dimensions and abrupt roll‐off skirts for transition bands. A technology demonstration filter with six stopbands placed at 1.91/2.38/3.54/5.19/5.79/6.85 GHz was constructed to verify the design and analyses. It is found that the measurement of a filter is consistent with the comparison of simulation data, which indicates that the proposed structure is an optional approach for BSF design. The filter proposed can be applied in the field of communication, information and coal mine automation.
This letter introduced the operating mechanism of proposed bandstop filters with asymmetric multiple‐mode resonator loaded with tree‐shape branches. Based on the design procedure, the centre frequencies of the proposed bandstop filters can be controlled due to the designed degree of freedom. Meanwhile, the proposed bandstop filters feature compact sizes and sharp roll‐off skirts for transition bands.
In the history of translating classical Chinese poetry, there are two kinds of translators. The first kind translate classical Chinese poetry “by way of intellectual, directional devices” (Yip, ...Wai-lim. 1969.
. Princeton, NJ: Princeton University Press: 16). What these translators are concerned with most is the coherence of their translations. They give little attention to the ideogrammic nature of Chinese characters. I call them traditional translators. These translators include those in the history of translating classical Chinese poetry from its beginning to the first decade of the twentieth century, although there are still some who translate classical Chinese poetry in this way later. The second kind of translator is highly interested in the images created by ideogrammic Chinese characters and tries to convey them in target language. We call them modernist translators. These translators are represented by some American modernist poets such as Ezra Pound, Amy Lowell, Florence Ayscough, etc. From the point of view of iconicity, modernist translators’ contribution lies in their concern with the iconic characteristics of Chinese characters. But they did not give enough attention to syntactical iconicity and textual iconicity in classical Chinese poetry.
For some Western translators before the twentieth century, domestication was their strategy to translate the classical Chinese poetry into English. But the consequence of this strategy was the ...sacrifice of the ideogrammatic nature of these poems. The translators in the twentieth century, especially the Imagist poets and translators in the 1930s, overcame the problems of their predecessors by developing their translation theory and practice in ways that are close to those of many contemporary semiotic translators. But both Imagist translators and contemporary semiotic translators have the problem of indifference to the feeling of the original in their translations.
This paper attempts to set up an aesthetic-semiotic approach to the translation of the iconicity of classical Chinese poetry on the basis of the examination of both Eastern and Western translation studies.
•We mined 12,880 articles related to biofertilizers in this study.•Biofertilizer research can be categorized into three phases.•Developing countries are keenly interested in the research of ...biofertilizers.•Biofertilizers provide nutrients, regulate crop growth, and improve soil conditions.•Pseudomonas, Azotobacter and Bacillus are the major microorganisms for biofertilizer.
The application of biofertilizers is becoming an inevitable trend to substitute chemical fertilizers for sustainable agriculture. To better understand the development of biofertilizers from 1980 to 2022, we used bibliometric mining to analyze 12,880 journal articles related to biofertilizer. The network cooccurrence analysis suggested that the biofertilizers research can be separated into three stages. The first stage (1980–2005) focused on nitrogen fixation. The second stage (2006–2015) concentrated on the mechanisms for increasing plant yield. The third stage (2016–2022) was the application of biofertilizers to improve the soil environment. The keyword analysis revealed the mechanisms of biofertilizers to improve plant-growth: biofertilizers can impact the nutritional status of plants, regulate plant hormones, and improve soil environments and the microbiome. The bacteria use as biofertilizers, included Pseudomonas, Azospirillum, and Bacillus, were also identified through bibliometric mining. These findings provide critical discernment to aid further study of biofertilizers for sustainable agriculture.
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In this study, a high entropy alloy CoCuFeNiTi1.2V0.4 was used as a novel brazing filler metal to braze the TiAl alloy. The microstructure and formation mechanism of TiAl joints were comprehensively ...investigated, and the effect of brazing temperature on the interfacial microstructure and mechanical properties of the joints was analyzed. The results showed that the joint interfacial formed three different zones with symmetrical characteristics after brazing. The joints were primarily composed of an intermetallic compound phases and high entropy solid solution phases. Ti-rich BCC phase and Cu-rich FCC phase are formed in the brazing seam center zone, which not only improves the strength and plasticity of the joint but as well as releases part of the residual stress. However, the reaction and diffusion of atoms at the interface would break the high entropy effect, and the compound layers could easily form under the conditions of concentration gradient and high temperature. With the brazing temperature increased, the thickness of B2 layer and τ3 layer in the seam increased and the bulk Cu-rich phase internal the seam center basically disappears. In addition, the amount of τ2 compounds precipitated in the B2 phase significantly increased at higher brazing temperatures. The maximum shear strength of the joint was 143.4 MPa when brazed at 1120 °C for 20 min.
•TiAl alloy successfully brazed with high entropy alloy filler.•The mechanism of high entropy effect and sluggish diffusion effect on brazing process is discussed.•The successive dissolution and interfacial interdiffusion of TiAl substrate and brazing filler form the reliable joint.•The shear strength of TiAl/TiAl alloy brazed joints reached 143.4 MPa.•Changes in the microstructure of the joint influence the joint strength.
Environmental barrier coatings (EBCs) are commonly used to protect SiC ceramic matrix composites (CMCs) from corrosion in combustion environments, thus extending their service life in hot-zones. The ...dominant process that affects the service life of CMCs is the thermal growth of oxide materials, which is facilitated by oxygen diffusion through the EBCs. In this study, the oxygen diffusion behavior through EBC materials, such as Sc2Si2O7, Yb2Si2O7, and Y2Si2O7, in a temperature range of 1100 °C–1300 °C was assessed using an 18O2 tracer. The 18O and 16O isotope exchange depth profiles were characterized by time-of-flight secondary-ion mass spectrometry (ToF-SIMS). The SIMS data were fit with a semi-infinite diffusion model to calculate the diffusion coefficients and activation energies for oxygen transport through the EBC materials. Y2Si2O7 had the lowest oxygen diffusion coefficient, while Yb2Si2O7 had the highest. The differences in oxygen diffusivity can be explained by the variations of the disilicate crystal structures in the different EBC materials. The analysis identified both crystal structure and bond length as dominant factors influencing oxygen diffusion. The methods and results of this study can be applied to the screening of EBC materials with strong oxidation resistance, thus ensuring a long service life for EBCs/CMCs.
In this paper, a novel CoCuFeNiTiV0.6 high entropy alloy interlayer was used for vacuum diffusion bonding of TiAl alloy and TC4 titanium alloy. The effects of bonding temperature and pressure on the ...interfacial microstructure, element diffusion behavior and mechanical properties of the joint were investigated. According to the microscopic morphological characteristics of the joint, it is divided into four zones. Zone I and zone III are the TiAl side interface diffusion layer and the TC4 interface diffusion layer, respectively. Zone II is the bonded high-entropy interlayer, and zone IV is the diffusion region of the TC4 substrate. Three diffusion layers of B2 phase, Al(Cu, Ni)Ti and Al(Co, Ni)2Ti phase were formed in zone I, while two diffusion layers of Ti-rich IMC and Ti2Ni phase were formed in zone III. With the increase of bonding temperature and pressure, the different diffusion layers on the TiAl side interface gradually thickened, and the β-Ti region on the TC4 side became wider and the Widmanstätten microstructure increased. The mechanical properties of the joints were evaluated by nanoindentation and shear tests. The hardness and elastic modulus at the TiAl side interface are up to 8.12GPa and 158 Gpa, respectively, which is easy to cause stress concentration. The maximum shear strength reached 96.2MPa bonded for 60min at 960 ℃ under 1.7MPa. The fracture location in the joint generally occurs at the interface of the Al(Cu, Ni)Ti layer/Al(Co, Ni)2Ti layer/HEA interlayer, and the fracture is mainly characterized by brittleness.
•Diffusion bonding of TiAl alloys to TC4 titanium alloys was performed using high-entropy alloys as interlayers.•The interlayer alloy can possess the benefits of both a ductile FCC phase along with the strength increment imparted by the BCC constituent phases•The mechanism of the effect of high entropy effect and sluggish diffusion effect on the diffusion bonding process is discussed.•Dynamic recrystallization and atomic interdiffusion at the interlayer interface are key factors for the formation of the joint microstructure.•The growth rate of the reaction layer with higher growth activation energy is greater than that of the reaction layer with lower growth activation energy.•With the increase of bonding temperature and pressure, the shear strength of the joint increases, and the shear strength of the joint reaches the maximum value of 96.2 Mpa.
Ideal structural materials usually require excellent mechanical properties, high entropy alloys/medium entropy alloys (HEAs/MEAs) are considered to be the key material to achieve this goal. In the ...current work, a novel L12 precipitation strengthened medium entropy alloy is designed. After rolling and recrystallization, the alloy which is then aged possesses a mechanical property of a yield strength of 1.09 GPa, an ultimate tensile strength of 1.5 GPa and nearly 20% elongation at room temperature (the as-aged alloy). However, the plasticity of the as-aged alloy which is fully recrystallized is poor at high temperature. Then, the non-recrystallized alloy, which is directly aged after rolling, containing coarse lengthening grain with lower grain boundary energy, exhibits excellent high temperature mechanical properties.
Humic acids (HAs) are macromolecular substances that play important roles in different areas of soil, atmosphere, water, and ecological environment restoration. Here, we applied bibliometric analysis ...to systematically evaluate HAs applications in the environmental field. In-depth analysis of the publication characteristics of 9145 articles published from 1980 to 2020 revealed that the number of articles published on HAs increased rapidly, with China having the largest number of publications (3109), followed by the United States (1949) and Germany (679). Specifically, the Chinese Academy of Sciences had the largest number of publications (647) and was the center of the most productive institutional cooperation network. HAs applications and mechanisms for treating organic pollutants and heavy metals are important research topics in the environmental field. HAs could reduce the toxicity of a variety of organic pollutants or eliminate pollutants through photodegradation and adsorption. These pollutants include antibiotics, herbicides pesticides, fungicides, and other phenolic compounds. Additionally, HAs might be also used to treat heavy metal pollutants, such as mercury, copper, cadmium, uranium, and aluminum. HAs could adsorb heavy metals, thereby reducing their mobility in the environment and toxicity. HAs also have the potential to degrade microplastics and contribute to climate change adaptation. However, bibliometric analysis showed that the molecular structure of HAs remains unclear, thereby limiting clarification of mechanisms and further applications for decontamination. These findings highlight the interaction between HAs and the environment and offer critical insight to support further development of HAs for environmental applications.
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•Bibliometrics methods are applied to analyze articles published in the field of HAs and environment from 1980 to 2020.•Content analysis shows that HAs can decontaminate organic pollutants via adsorption and photodegradation.•HAs can also treat heavy metal pollutants via adsorption.•HAs can be occupied to treat microplastic pollution and mitigate the effects of climate change.
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