Mode Transformation Research Articles

Publisher's Note: “High-performance direct terahertz modulator based on resonance mode transformation for high-speed wireless communication” [Appl. Phys. Lett. 121, 231104 (2022)

Publisher's Note: “High-performance direct terahertz modulator based on resonance mode transformation for high-speed wireless communication” [Appl. Phys. Lett. <b>121</b>, 231104 (2022)

Twin boundary spacing and loading direction dependent tensile deformation of nano-twinned Al10(CrCoFeNi)90 high-entropy alloy: An atomic study

Experiments have shown that nanotwins play an important role in strengthening and toughening high-entropy alloys (HEAs), which are closely associated with twin boundary (TB) spacing. Understanding the TB spacing dependent deformation mechanisms is helpful to design strong and ductile HEAs. In this work, the TB spacing dependent tensile deformation of equiaxed- and columnar-grained Al10(CrCoFeNi)90 HEA with various TB spacings has been studied via molecular dynamics simulation. The results show that equiaxed-grained samples with nanotwins have higher strength than twin-free counterpart. De-twinning at small TB spacing softens equiaxed-grained samples, which is similar to that observed in nano-twinned Cu. However, for the columnar-grained samples, it is interesting to find that no softening occurs with decreasing TB spacing when the loading direction is parallel or vertical to TB. In the case of parallel loading, the main dislocation activities change from hairpin- to necklace-like dislocations with decreasing TB spacing, and this dislocation mode transformation leads to a slow-to-sharp-increase transition in strength. Our theoretical analysis indicates that the sharp increase in strength is related to the severe lattice distortion in HEAs which makes the de-pinning process of necklace-like dislocation unit difficult. In the case of vertical loading, the dominated dislocation motions shift from dislocation slipping in the twin and matrix regions to dislocation cutting through TBs as TB spacing decreases from 6.2 to 0.62 nm, the latter of which leads to shear bands nucleation and expansion. Yet, the strength still shows a monotonous increase due to the increasing difficulty of dislocation nucleation in the initial plastic deformation that produces significant strengthening.

Fault Identification of Double-circuit Transmission Lines on The Same Tower Based on CEEMDAN-SSA-SVM

In order to improve the reliability of double-circuit transmission lines on the same tower, by analyzing the variation law of inverse wave of fault voltage inside and outside the area, a support vector machine (SVM) method for internal and external fault identification of double-circuit transmission lines on the same tower based on adaptive noise complete ensemble empirical mode decomposition and sparrow search algorithm optimization is proposed. This method carries on the phase mode transformation of the current and voltage after the fault. The inverse wave current in the time window after the fault is adaptively decomposed by CEEMDAN, and the corresponding energy entropy is extracted to form the feature vector. The SMOTE algorithm is used to balance the fault samples outside the region. Finally, the feature vector set is input to the SSA-SVM classifier for training and testing. Through theoretical and simulation analysis, the following results are obtained: the algorithm in this paper is not affected by fault initial angle, transition resistance and fault distance.

A New Identify Disruptive Technologies Algorithm Based on Technology Develop Network

The identification of disruptive technologies is intended to focus on training and incubation in advance and is an important means to accelerate the upgrading of industrial structure and the transformation of developmental mode and seize the commanding heights of future development. Based on summarizing the existing major identification methods of disruptive technologies, this paper concludes the rule that “disruptive technologies are always at the root node of a certain classification in the deeply classified technology development network”. It also proposes a new algorithm to use term frequency-inverse document frequency technology and a patented Subject-Action-Object structure to extract technical features, develop networks based on similarity matrix generation technology, and identify subversive technologies based on the depth classification model. Using patent data, it is found that the technology development network generated by the algorithm proposed in this paper can effectively show the trajectory of technology development by fitting the patent citation relationship. Through this algorithm, we have successfully identified technologies that have had disruptive effects in the field and verified the effectiveness of this algorithm.

High-performance direct terahertz modulator based on resonance mode transformation for high-speed wireless communication

The developing terahertz wireless communication demands higher performance modulators. In this Letter, a mechanism of resonance mode transformation for a high-speed terahertz direct amplitude modulator with rather low insertion loss and high modulation depth is presented. By embedding an H-shaped resonance structure, which consists of a fin-line and two flip-flopped GaAs Schottky diodes, into the E-wall of a waveguide, the fed terahertz waves are modulated by the inductive-capacitive (LC) resonance transformation of the structure. Based on this mechanism, a modulator working in the frequency band around 140 GHz is fabricated and packaged. Thanks to the LC resonance transformation, the presented modulator exhibits a low insertion loss of 1.8 dB at 138 GHz, a large modulation depth higher than 99% at 148 GHz, and high modulation speeds up to 30 Gbps at 146 GHz. Accordingly, the presented mechanism paves a promising route to develop high performance terahertz direct modulators, which is of great significance for terahertz high-speed wireless communication.

Improved comprehensive mechanical properties of oscillatory pressure sintered WC–ZrO2–Al2O3 ceramics with VC/Cr3C2 addition

To optimize the microstructure and comprehensive mechanical properties of WC-based ceramics, the addition of grain growth inhibitors was an important and effective approach. The effect of VC/Cr3C2 addition on the densification behavior, microstructural evolution, comprehensive mechanical properties of WC-based ceramics fabricated by oscillatory pressure sintering was investigated in this work. The introduction of VC/Cr3C2 significantly controlled the size of WC grains and regulated the distributed uniformity of ZrO2 and Al2O3 grains in the WC matrix. When the added contents of VC and Cr3C2 were 0.2 wt% and 0.8 wt% respectively, WC-based ceramics with the best comprehensive mechanical properties were achieved, in which their Vickers hardness, fracture toughness and bending strength were up to 29.15 GPa, 8.37 MPa m1/2 and 1513 MPa, respectively. Furthermore, the enhancement of mechanical properties was mainly attributed to the grain refining strengthening, the transformation of fracture modes and dislocation toughening.

Problems and prospects for the development of remote HRM in Ukraine in the war and post-war period

The development of information and communication technologies in the conditions of a new, digital economy naturally transforms the sphere of management and social and labor relations, and non-traditional forms of employment and labor organization are spreading. Quarantine measures taken by governments in connection with the COVID-19 pandemic, as well as the war on the territory of Ukraine, have become catalysts for the spread of remote work. The function of human resource management (HRM), performing an important connecting role of coordinating the interests of employers and employees, organizing the labor activity of personnel, itself becomes an object of transformation of labor modes, which requires prompt study of this phenomenon. A survey of HR-specialists of Ukraine in various industries, professional specializations and age groups revealed the prospects of remote HRM due to the availability of material and technical base, software and existing experience of &amp;quot;emergency&amp;quot; transfer to remote mode. At the same time, the existing socio-psychological barriers (prejudices of management, lack of informal communication, emotional defects in communication in the online work format) will contribute in the future, according to the majority of HR specialists, to the spread of a mixed work format in its various forms: distribution of working time for work in the office and outside the office; fixing the format of remote work for some categories of personnel and maintaining the traditional format for others; transition of some industries to remote employment. The results revealed actualize the need to search for scientific, theoretical and practical solutions to overcome obstacles to the development of remote work (including HRM) in the new economy.

Pandemic Lived Experience, Crip Utopias, and Dismodernist Revolutions: For a More‐Than‐Social Model of Disability

At its height, the Covid‐19 pandemic dispersed across society a perception of bodyminded contingency that ushered in modes of “building community” that were unimaginable in pre‐pandemic times, alongside an intensification of health and social inequalities. From the start, disabled people intervened on social media to stress the considerable extent to which the pre‐pandemic knowledge derived from their lived experience, disability theory, and disability rights’ organising could contribute both to the critique of how in pandemic times people were made differentially disposable and to the creation of new relationalities, mostly online, around the principle of accessibility. This article explores how a critical perspective rooted in the lived experience of disability builds on these interventions to excavate the role played by the lived experience of bodyminded contingency and vulnerability during the pandemic in generating a radical transformation of modes of living (together). First, it will suggest that this radical transformation powerfully resonated with the politics of accessibility associated with disability politics. It will do so by delineating the critical significance of commentary produced during the pandemic by disability theorists and activists, as well as the relationship between the perception of widespread bodyminded contingency and vulnerability and the development of “crip utopias of accessibility” and “dismodernist revolutions” during the pandemic. It will then locate this experiential spread of bodyminded contingency and vulnerability at the core of pandemic infrastructural sensibilities. I will conclude by reflecting on its relevance for the development of a “more‐than‐social” model of disability which attends to the crip world‐making power of disability as fundamentally entangling the social and the biological.

Enhanced performance of airfoil-based piezoelectric energy harvester under coupled flutter and vortex-induced vibration

This paper designs a novel airfoil-based flutter piezoelectric energy harvester attached to an unconstrained trailing-edge flap, for transforming the vibration mode and improving the harvesting performance. The flap is first constrained by the flap spring rod and takes place the torsion motion at the smaller angle around the flap shaft. While, when the flap spring rod is removed, the flap is unconstrained, rotates freely, and results in transforming the vibration mode. The mathematical model of fluid-structure-electric coupled fields of the harvester system is first derived, the simulation model of the multi-physical coupled fields is then built, and the wind tunnel experimental setup is finally fabricated. The influence of the flap motions and structural parameters on the flow field, vibration characteristic, and harvesting performance are investigated theoretically, numerically, and experimentally. The results demonstrate that the vibration mode of the harvester system transforms from flutter to vortex-induced vibration at the smaller flap damping coefficients. The flow field verifies that the vortices are shedding at the trailing-edge of the flap and the vibration mode transformation occurs. The unconstrained flap first takes place flutter and then vortex-induced vibration with the increase of the airflow velocity, which enhances the harvesting performance. The unconstrained flap, pitch free play, and the smaller plunge stiffness coefficient decrease the flutter onset of velocity, enhance the aeroelastic vibration and thus improve the harvesting performance. A maximum plunge amplitude of 0.077 m, output voltage of 36.83 V, and output power of 5.43 mW can be harvested for the harvester system “Unconstraint and 1 mm” at 14.39 m/s and 278 N/m. The maximum enhancement ratio of output power for “Unconstraint and 1 mm” is 727.4% higher than that for “Constraint and Zero”. The designed harvester can directly power 14 LEDs and indirectly power a LED for 5 s. This research provides an essential foundation for designing more efficient piezoelectric energy harvesters for promoting actual utilizations in the low-power wireless sensor system.

Discussion on the Strategy of Transforming Enterprise Financial Accounting into Management Accounting in The Era of Big Data

The advent of the era of big data has caused great impact on enterprise financial management, but at the same time, enterprise financial management has also ushered in the opportunity of innovation and development. As a modern enterprise under the new economic situation, financial personnel should not only do a good job of self-positioning, but also conform to the development needs of the big data era, speed up the transformation and upgrading of enterprise financial accounting mode to management accounting mode, and formulate a transformation and upgrading scheme that is closely integrated with enterprise development, so as to ensure that enterprises are always in a favorable position in the fierce market competition on the premise of enhancing their comprehensive competitiveness. This paper mainly discusses and analyzes the strategy of financial accounting to management accounting in the era of big data.

The Research and Practice of Talents Training Mode of Forest Engineering Major based on Industry-University-Research Cooperation

Along with the adjustment of industrial structure and the transformation and upgrading of development mode, the demand for complex innovative talents is increasingly strong. Taking Forest engineering major of Northeast Forestry University as an example, this paper introduces the reform mode of talent training program under collaborative education and its beneficial effects, and points out the existing problems in current industry-university-research.

Study on the mechanical properties of fiber-modified iron tailings stabilized by lime and fly ash based on energy analysis

After being cured by lime and fly ash and then modified by fiber material, waste iron tailings can obtain good road performance, which can not only reduce the accumulation of iron tailings but also save natural resources and can be used as a new road material with good performance. In this study, polypropylene fiber (0 %, 0.25 %, 0.5 %, 0.75 %, 1 %) was added to lime-fly ash solidified iron tailings (LHT) to produce a new type of road composite fiber modified two-ash iron tailings (LHTF). The mechanical properties of LHTF were analysed by unconfined compressive tests and splitting tensile tests, and the optimal ratio of LHTF was obtained. The internal failure mechanism of LHTF was explored and explained by analysing the transformation of the macroscopic failure mode and the change law of the energy absorption capacity of materials. The results show that with increasing fiber content, the unconfined compressive strength, splitting tensile strength and strength gain ratio first increase and then decrease. When the fiber content is 0.75 %, LHTF can achieve the best tension and compression performance and has the largest peak strain. With the increase in fiber content, the failure mode of LHTF gradually changes from brittle failure to ductile failure, and obviously different types of failure characteristics can be seen at the failure interface. The ductility failure characteristics of LHTF with the best fiber content are the most obvious, and the brittleness index is the lowest. The total strain energy density and elastic strain energy density of LHTF first increased and then decreased, while the change law of dissipated energy proportion showed the opposite situation. This study provides a reference for the recycling and utilization of waste iron tailings as road materials.

Comparative Energy Consumption Structure and Mode between China and Major Energy-Consuming Countries Under the Background of Carbon Emission Reduction

The top 23 countries with energy consumption accounting for 80% of the worldwide total in 2020 were selected as the research objects for this study. The energy consumption structure of these countries has been compared and studied from the proportion of clean energy in primary energy, the clean utilization rate of fossil energy, and the proportion of electric energy in terminal energy consumption, and the characteristics of energy consumption intensity were also analyzed based on the energy consumption per unit GDP, capital, and unit land area. The energy consumption patterns of various countries in social-economic operation, production, and life were also discussed, combined with the characteristics of industrial structure and subsector energy consumption. The concept of natural carbon sink load ratio of energy consumption was put forward, and the advantages and challenges of energy consumption mode transformation under carbon peak and carbon neutralization goals in China were identified and analyzed. The results showed that:the proportion of clean energy in primary energy, the proportion of energy consumption for power generation, the clean utilization rate of fossil energy, and the proportion of electric energy in terminal energy consumption in China were 15.90%, 53.48%, 37.51%, and 26.54%,respectively,all of which were in the forefront among the major energy-consuming countries in the world. China has built a favorable structural foundation for energy-intensive and clean utilization and formed a green and low-carbon energy consumption model; the proportion of non-industrial and agricultural energy consumption, especially that of transportation energy consumption, were both the lowest among major energy-consuming countries, and there is still much room for improvement in overall energy productivity based on the optimization of industrial structure. However, the relatively short carbon peak and neutralization target period poses a great challenge to the development speed and scale of clean energy to China, and the international situation under the constraint of carbon emission also increases the difficulty for China to achieve the carbon reduction goal by optimizing and adjusting the industrial structure.

Multi-dimensional superposition: Rural collaborative governance in Liushe Village, Suzhou City

Rural governance has become a hot topic alongside rapid urbanization, especially in several Global South countries. Under China's new-type urbanization, rural and suburban space in the Yangtze River Delta has entered the metropolitan system. The rural-urban boundary has been blurred, reflecting the characteristics of planetary urbanization. Rural governance in the metropolitan fringe areas exhibits characteristics different from that in the traditional rural areas. Taking Liushe Village of Suzhou as a typical case, this study linked planetary urbanization to collaborative governance theory and constructed a multi-dimensional conceptual framework to explore the process, characteristics, and mechanism of its rural governance based on qualitative research methods. Liushe has undergone three stages under rapid urbanization: traditional agriculture, ecological conservation, and culture-tourism integration, which have led to the continuous transformation of the rural governance mode. Local governments, creative entrepreneurs, and the village collective are the three key subjects in formulating collective actions. The collaborative governance of Liushe reflects the multi-dimensional superposition of institutional design, social capital, and collective attributes. The case study provides a reference for exploring China's new rural governance mode. The rural spatial reconstruction of Liushe Village partly supports the view of planetary urbanization, whereas its multiple logics under unique institutional conditions expand the research framework of collaborative governance.

Adaptive Mode Transformation for Wear Leveling in Nonvolatile FPGAs

Nowadays, field programmable gate arrays (FPGAs) have been widely adopted to serve as accelerators in artificial intelligence and big data related applications. Since the static random access memory (SRAM)-based FPGA is suffering from limited density and high leakage power, nonvolatile FPGAs have been proposed, where SRAM is replaced with emerging nonvolatile memories (NVMs). Multilevel cell (MLC), which can store multiple bits within one memory cell, further improves the density of nonvolatile FPGAs and shows great potential to enable large on-chip memory. However, it suffers from limited lifetime. In this article, we propose a wear leveling scheme to improve lifetime of MLC-based nonvolatile FPGAs. Instead of generating a series of configuration files for runtime reconfiguration, we propose to identify write-heavy MLC regions and dynamically transform them to durable single-level cell (SLC) mode. Specifically, we propose three modules: 1) pertaining to write behavior monitor; 2) approximate cost calculator; and 3) mode transformation manager to achieve adaptive mode transformations. We consider FPGA features to design these modules, which is different from implementations for MLC-SLC transformation in CPU architecture. Evaluation shows that the proposed scheme can improve lifetime for MLC nonvolatile FPGAs by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.03\times $ </tex-math></inline-formula> , at cost of 12.5% storage overhead.

From Government–Society to Party–Masses: The Community Governance Mode Change in Shenzhen

Most urban community studies in China rely on the state–society framework. However, this structural perspective can hardly explain the diverse modes of community governance and their changes over time. This article outlines Shenzhen's 20-year (1999–2019) history of community reform and constructs a framework based on historical institutionalism to analyse Shenzhen's community governance modes over various periods and their changes. First, diversified governance ideas and power structures constructed various community governance modes over this period. Second, community governance mode changes were embedded in local grassroots governance fields. The original governance arrangements, the policy guidance and the ideas of the dominant agencies (the Ministry of Civil Affairs and the Party) at different stages are critical in explaining the transformation of community governance modes. Third, the dominant subject's institutional bricolage within the constraints and empowerment of the institutional context was the critical mechanism of the governance mode transformation. The historical institutionalism framework for community governance transformation provides a new direction for understanding community reform and evaluating evolving local state–society relations.

Academic tutoring in the development of the teaching-learning process in higher education

In the field of Higher Education at the present time, changes are perceived in learning environments, particularly the virtual one. Therefore, university teachers have had to redefine their teaching work, and therefore the nature in which the teaching-learning process takes place. This consideration implies a transformation of the teacher's mode of action, from the didactic and methodological point of view in the conception of strategies, to generate significant learning that fosters the development of cognitive independence in students. From this perspective, academic tutoring becomes a tool that allows accompanying and guiding students to build their learning in the context of their training, a more personalized attention, from a relationship of help and accompaniment, to monitor and evaluate the learning from the active participation of this in the metacognitive development for the construction of knowledge. In the present study, the significance of academic tutoring is addressed, as a resource to accompany students in the teaching-learning process at the university, which allows them to reflect on their cognitive processes and on procedural self-knowledge for the learning process in students. environments in which it develops.

The bioeconomy and its untenable growth promises: reality checks from research

This paper starts out from the observation that recent official bioeconomy strategies and policy concepts are markedly more moderate in their promises of economic growth compared to the high-flying expectations of a ‘biotech revolution’ promoted around the turn of the millennium. We argue that this stepwise process of moderation is partly due to a series of ‘reality checks’ to which various strands of research on the bioeconomy have (willingly or unwillingly) subjected these promises, forcing governments to move away from visions exposed as unrealistic and to adopt more humble ones. We identify four such ‘reality checks’, originating from research on (a) bioeconomy discourses and knowledges, (b) contestation and power dynamics among actors and competing interests in bioeconomy politics and policymaking, as well as on (c) the economic and (d) biophysical dimensions of existing bio-based economies. In conclusion, we argue that bioeconomy research should adopt a broader perspective that considers transitions toward bio-based processes and resources as but one element in a comprehensive social–ecological transformation of current modes of production and living, and that understanding the dynamics of societal conflict around that transformation is crucial for assessing the social possibility of bioeconomy visions.

Multi-Element Fully Decoupled Inverted-F Antennas for Mobile Terminals

In this article, a multielement fully decoupled linearly placed inverted-F antenna (IFA) array is proposed for mobile terminals. A hybrid decoupling method is used to mitigate the mixed types of mutual couplings among the multiple IFAs: introducing multiple decoupling capacitors for the couplings of two back-to-back IFA pairs and T-shaped mode transformers for the remaining couplings. The decoupling capacitors not only decouple the back-to-back IFA pairs but also broaden the impedance bandwidth of each IFA. The T-shaped mode transformer transforms the concerned antenna from an IFA mode into a balanced loop mode, preventing the induced current on the victim IFAs of the face-to-face and back-to-face pairs. One four-element example and one eight-element example are designed and measured to justify the proposed decoupling concept. The measured results of the four-element IFAs show that after decoupling, all the six mutual couplings among the four IFAs are reduced by about 10 dB from 3.3 to 3.8 GHz, with average total efficiencies throughout the band improving from 57% to 72% for IFA 1 and from 47% to 55% for IFA 2. An eight-element IFA array is built utilizing the pattern diversity of two proposed four-element IFA blocks, achieving inter-block isolation of better than 20 dB. And a six-element linear IFA array is also designed to prove the generality of the proposed method.

Research Status and Development Trend of Intelligent Mechanized Pepper Harvesting

Since the reform and opening up, the mechanization level of China's agricultural production has been significantly improved. Intelligent mechanization of agricultural production is an inevitable trend for future social development. It is based on intelligent equipment, with data and knowledge as the core elements to enable the deep integration of modern science and technology with agriculture. This enables digital perception, intelligent decision making, and precise operation of the whole agricultural production process, further improving labor productivity, land output rate and resource utilization rate. This paper introduces the development status of agricultural production in China and abroad with pepper harvesting, analyzes the necessity of changing China's agricultural production to intelligent mechanized production, summarizes the opportunities and challenges in intelligent mechanization, and accordingly puts forward the development direction and development route of China's agricultural production. To promote the transformation of China's agricultural production mode from mechanization to wisdom, this paper puts forward countermeasure suggestions such as strengthening the construction of agricultural machinery equipment R&amp;D and innovation system, strengthening the construction of agricultural machinery promotion system, strengthening the construction of agricultural machinery socialization service system, and accelerating the construction of wisdom agriculture demonstration area.