Main Path Research Articles

Tracing policy diffusion: Identifying main paths in policy citation networks

Citation-based main path analysis (MPA) has been widely applied to identify developmental trajectories of science and technology, while rarely used to detect paths of policy diffusion. Compared with scientific publications and patents, policy documents show some distinct characteristics, such as citation relationships with different legal validity, which could be considered to improve the policy citation analysis. To this end, this study formally constructs a policy citation network based on a plethora of citing/cited links embedded in the textual content of policy documents and proposes a preference-adjusted main path analysis (PMPA) approach to track historical routes of policy diffusion. PMPA incorporates two kinds of policy citation preferences, including validity bias and time bias. An evidence analysis from China’s new energy policies (NEPs) is implemented to show the efficacy of the proposed approach. The results unveil that the preference-adjusted main path approach can capture more important policies and more informative main paths of policy diffusion than the original MPA. Moreover, our research can yield in-depth insight into the evolutionary process of policy diffusion and provide guidance for policy-makers and industry decision-makers to formulate practical policy-making.

Shedding Light on the Photophysics and Photochemistry of I-Motifs Using Quantum Mechanical Calculations.

I-motifs are non-canonical DNA structures formed by intercalated hemiprotonated (CH·C)+ pairs, i.e., formed by a cytosine (C) and a protonated cytosine (CH+), which are currently drawing great attention due to their biological relevance and promising nanotechnological properties. It is important to characterize the processes occurring in I-motifs following irradiation by UV light because they can lead to harmful consequences for genetic code and because optical spectroscopies are the most-used tools to characterize I-motifs. By using time-dependent DFT calculations, we here provide the first comprehensive picture of the photoactivated behavior of the (CH·C)+ core of I-motifs, from absorption to emission, while also considering the possible photochemical reactions. We reproduce and assign their spectral signatures, i.e., infrared, absorption, fluorescence and circular dichroism spectra, disentangling the underlying chemical-physical effects. We show that the main photophysical paths involve C and CH+ bases on adjacent steps and, using this basis, interpret the available time-resolved spectra. We propose that a photodimerization reaction can occur on an excited state with strong C→CH+ charge transfer character and examine some of the possible photoproducts. Based on the results reported, some future perspectives for the study of I-motifs are discussed.

Technological Cohesion and Convergence: A Main Path Analysis of the Bioeconomy, 1900–2020

The bioeconomy comprises a range of industries that are related through their reliance on biomass and their use of biotechnology, such as agriculture, food processing, and parts of the life sciences. While the bioeconomy has received increasing attention in the context of innovation policy, the internal structure of its underlying technological field remains opaque, and little is known about the long-term processes through which its subdomains have co-evolved. It is precisely the structure (cohesion) of this field and its evolution (convergence) over the course of more than a century of technological development that this article seeks to disentangle. For this purpose, we draw on a dataset of more than 1.5 million patent families and use bibliometric methods and main path analysis to assess the internal and external cohesion of the field and trace its long-term technological development. Our analysis supports two main findings: First, instead of becoming more closed as a field, the cohesion of technologies within the bioeconomy with external technologies has increased over time. Second, the bioeconomy technological field shows clear signs of structural convergence over the second half of the 20th century, with the biochemical domain absorbing most of the trajectories of technological knowledge originating in the traditional application areas. As such, the study illustrates the long-term processes of technological cross-fertilization through which the bioeconomy, as an example of a heterogeneous technological field, developed its ‘backbone’ of technological knowledge.

Vulcanization failure mechanism analysis of lead-frame LED package

Light-emitting diodes (LED) failure can be attributed to various factors such as vulcanization, which is considered as one of the primary causes. The main consequence of vulcanization is the production of black silver sulfide, a result of silver and sulfur ion interaction within the plating layer. The consequences of this reaction can be quite severe, leading to a reduction in luminous flux, color temperature drift, golden ball and support fracture. In this work, following an analysis of the process structure characteristics of LED support, four vulcanization failure paths have been identified. To determine the main vulcanization path of the LED stent, various tests, such as the vulcanization corrosion test, the red ink test, and the cross-section test, have been conducted. This work provides an innovative and constructive approach for directing failure research in LED package.

The technology management path and its development trend in the field of communication engineering in the era of big data

In the face of the sustainable development of social economy and technical means, the current demand for communication is getting higher and higher, so improving the technical ability of the communication industry can better meet the communication needs of social justice. From the perspective of the long-term development of the communication industry, it is very important to identify the main path and development trend of technology management. Therefore, after understanding the basic characteristics of the field of communication engineering in the era of big data, this paper mainly studies the three technical management paths of cost control, talent training and cable management, and then determines the development trend of the field of communication engineering in the era of big data.

Numerical analysis of hydromagnetic micropolar squeezing flow lubricated between porous elliptical plates

An attempt is made to analyze the effects of micropolar fluid squeezing film implementation between porous elliptical plates under the application of an external magnetic field. The appropriate improved hydromagnetic Reynolds equation governing the pressure distribution is acquired. The Reynolds equation is solved for lubrication features such as pressure distribution, load-carrying capacity and time-height relationships. It is noticed that a micropolar lubricant with a magnetic field may considerably impart a much-appreciated increase in load-carrying capacity, pressure distribution and response time compared to the classical case. Nevertheless, it is found that, as with the magnetic field, the larger values of the fluid gap number and the coupling number increase lubrication characteristics. Also, it is found that such a bearing cannot support a large number of lubrication characteristics because of the pores on the main path of fluid flow.

Inter-industrial embodied carbon transfers in a developed subnational region: a case study of Guangdong Province, China

The close production and consumption relationship between industries leads to the embodied CO2 transfer among industrial sectors along with the exchange of products. Thus, grasping the situation of embodied carbon transfers from the demand side is of great significance for better reducing a country or region’s CO2 emissions. This study investigates the embodied carbon transfers in Guangdong Province from 2002 to 2017 from the industrial dimension by applying a hypothetical extraction method. An enhanced generalized RAS method was utilized to predict the intersectoral carbon transfers in 2025 and 2030. The results show that, from 2002 to 2017, the average proportion of carbon emission output of 72.11% made the production and supply of electricity and heat sector the main CO2 emission transfer exporter, while the other service and construction sectors were the leading importers. Moreover, the embodied carbon transfers between these three sectors are the main carbon transfer paths. By 2025, the other service sectors will become the largest embodied carbon importers, surpassing the construction sector. Therefore, it is necessary to control the consumption demand of other service and construction sectors on the demand side to reduce carbon emissions driven by demand.

Reaction heat effect and change characteristics of key groups in coal-oxygen intrinsic reaction path.

The intrinsic reaction of coal with oxygen in the process of low-temperature oxidation is the main reaction path leading to self-heating and spontaneous combustion of coal. Most of the existing studies regard the coal oxidation as an overall reaction, ignoring the multi-path characteristics of coal low-temperature oxidation, and it is difficult to accurately explore the intrinsic reaction characteristics between coal with oxygen. Therefore, the low-temperature oxidation process of coal was studied by using a C80 microcalorimeter and in situ FTIR technology from the macro and micro levels. The "profile subtraction method" was used to study the coal-oxygen intrinsic reaction process, and the reaction heat effect and the change characteristics of key functional groups in the process were analyzed. Furthermore, the gray correlation analysis method was used to study the relevant characteristic parameters in the reaction process and grasp the essential structure-activity relationship. The experimental results show that, compared with the overall reaction process in air atmosphere, the change in the heat release of the coal-oxygen intrinsic reaction path has changed to different degrees, and the change in the slow oxidation stage is the most significant (the heat absorption decreases by 70.1-90.9%). In addition, the characteristic temperature points show different degrees of advance, of which the initial exothermic temperature point is the largest (about 21-46 °C), which directly leads to a significant shortening of the slow oxidation stage (30.1-47.4%). The changes of functional groups in the intrinsic reaction path are more regular. With the increase of temperature, the oxygen-containing functional groups -C=O and the aliphatic hydrocarbon functional groups -CH2- and -CH3 showed a fluctuating trend of increasing and decreasing, respectively. The oxidation heat-contributing functional groups of coal are mainly related to the degree of metamorphism and the functional group reaction characteristics during the reaction. With the deepening of coalification degree, the main heat-contributing functional groups as a whole showed the change rule of oxygen-containing functional groups → aliphatic hydrocarbon functional groups → aromatic hydrocarbon functional groups. In addition, the change of -OH content in the three coal samples has a high correlation with the change of the total heat release of coal.

Collaboration or competition? A science map for promoting the sustainable transition of port relationships

Port relationships have received continuous attention from the academic community. However, the existing studies do not provide a science map for promoting the sustainable transition of port relationships. This study combined quantitative analysis and qualitative discussion on the previous research of port relationships from 1999 to 2022. A total of 339 articles were quantitatively analyzed and visualized the knowledge body of existing studies. The main key research topics and evolution path of these 339 articles were quantitatively analyzed and qualitatively discussed for constructing a science map of port relationships. The results indicate that the academic community of port relationships does not show a significant Matthew effect. Existing research on port relationships is supported by 16 classical references with higher co-citation frequency, and the knowledge foundation of port relationships is divided into three significant co-citation clusters. The main research topics of port relationships show evolutionary trends during different research periods and mainly focus on competition, cooperation, and co-opetition. Finally, three future research directions are predicted based on the science map for guiding the future research of port relationships: (1) integration mechanism and strategy of dry ports and multimodal transportation; (2) comprehensive competitiveness evaluation index system; (3) port adaptation investment assessment method and optimization strategy. This study provides a comprehensive science map for promoting the sustainable transition of e academic collaborations and management practices on port relationships.

Mineral transformations and molten mechanism during combustion of biomass ash

With continuous expansion of the heat produced from biomass energy, the problems of biomass ash melting and slagging have become increasingly prominent. Studies of mineral transformations and melting behaviour in biomass ash are helpful for understanding the slagging process fully. In this paper, ash samples prepared from corn straw, sawdust and rice husk were studied with an ash melting point analyser, simultaneous thermal analyser, XRD and SEM‒EDS. The results showed that the deformation temperature (DT) of corn straw was the lowest, while that of rice husk was the highest. The variations in ash weight loss and temperatures indicated that the two main paths for ash loss were decomposition and volatilization. With increasing combustion temperature, eutectic salts with low melting points were formed in the ash, such as potassium silicate and calcium silicate, and the liquid phase and crystalline phase coexisted at 1000 °C. In this paper, the influence of different elements on the ash structure and the changes occurring in ash structure during combustion and ash melting point tests are explained by considering the silicate network structure. The ash melting behaviour observed during biomass combustion is clarified, which provides a theoretical basis for preventing biomass ash from melting and slagging.

Navigating the crowdfunding landscape: a study of knowledge trajectories based on main path analysis

PurposeCrowdfunding (CF) has become an increasingly popular means of financing for entrepreneurs and has attracted significant attention from both researchers and practitioners in recent years. The purpose of this study is to investigate the core content and knowledge diffusion paths in the CF field. Specifically, we aim to identify the main topics and themes that have emerged in this field and to trace the evolution of CF knowledge over time.Design/methodology/approachThis study employs co-word clustering and main path analysis (MPA) to examine the historical development of CF research based on 1,528 journal articles retrieved from the Web of Science Core Collection database.FindingsThe results of the analysis reveal that CF research focuses on seven themes: sustainability, entrepreneurial finance, entrepreneurship, fintech, social entrepreneurship, social capital, and microcredits. The analysis of the four main paths reveals that equity CF has been the dominant topic in the past years. Recently, CF research has tended to focus on topics such as fintech, the COVID-19 pandemic, competition, Brexit, and policy response.Originality/valueTo the authors' best knowledge, this is the first attempt to explore knowledge diffusion dynamics in the CF field. Overall, the study offers a structure for analyzing the paths through which knowledge is diffused, enabling scholars to effectively manage a large volume of research papers and gain a deeper understanding of the historical, current, and future trends in the development of CF.

Decomposition and reaction characteristics of C6F12O/N2 with rubber materials based on ReaxFF

C6F12O is considered to have potential for application in medium and low voltage electrical switchgear due to its excellent insulating properties. In order to ensure the stable operation of the equipment, it is necessary to study the compatibility of C6F12O/N2 gas with the rubber sealing materials used in insulating equipment. In this paper, EPDM, NBR and FKM are selected to conduct thermal acceleration experiments under 96 % C6F12O/4 % N2 gas at 40 ℃, 90 ℃, 110 ℃ and the changes of gas mixture before and after the experiments are analyzed by GC-MS. At the same time, the molecular system of gas mixture and rubber is constructed, and the reaction process of the system is simulated and the main decomposition path of rubber and the generation path of C2F are obtained at 1000–4000 K by using ReaxFF force field. The experimental results show that C6F12O/N2 gas mixture reacts with three rubbers at 40 ℃, 90 ℃, 110 ℃ and generate gas C3F6, C3F7H and by-products CS2. The theoretical results indicate that the decomposition products of mixed gas and rubber materials at high temperature are mainly H, F, CF2, CF3, and the reaction products are mainly C2F. Through pathway tracking, it is found that the decomposition products of C6F12O and rubber may react in multiple ways to generate C3F6 and C3F7H, which originate from the complex reaction of rubber and gas mixture. The compatibility between C6F12O/N2 and FKM is greater than that of NBR and EPDM. The simulation results are consistent with the experimental results. The results can provide a theoretical reference in the selection of sealing materials for equipment using C6F12O/N2 gas mixture as the insulating medium.

Four Decades of Chief Information Officer Research: A Literature Review and Research Agenda Based on Main Path Analysis

Despite the relevance and maturity of the Chief Information Officer (CIO) research field, no studies exist that exhaustively summarize the current body of knowledge, focusing on the development of the field over its entire timespan. The paper at hand addresses this research gap and presents an exhaustive literature review on the CIO research field using main path analysis. We identify the central papers in CIO research and eight main research streams by quantitatively and qualitatively analyzing 466 papers. We find that established research streams, e.g., 'Evolving role of the CIO' and 'CIO hierarchical position and relationships' as well as recently emerging research streams, e.g., 'CIO as business enabler' and 'CIOs and IT security,' draw growing attention. Based on our findings, we develop promising further avenues for research in the CIO field.

Tracing Knowledge Diffusion Trajectories in Scholarly Bitcoin Research: Co-Word and Main Path Analyses

In the burgeoning field of bitcoin research, a cohesive understanding of how knowledge and insights have evolved over time is lacking. This study aims to address this gap through an exploration of 4123 academic articles pertaining to bitcoin. Utilizing co-word analysis and main path analysis (MPA), it uncovers key themes and seminal works that have substantially influenced the field’s progression. The identified clusters, including safe haven, internet of things (IoT), proof of work (PoW), market efficiency, sentiment analysis, digital currency, and privacy, shed light on the multifaceted discourse surrounding bitcoin. The MPA, incorporating both forward and backward local paths, traces an evolving narrative, starting from an in-depth exploration of bitcoin’s structure, anonymity, and contrasts against traditional financial assets. It tracks the shift in focus to broader market dynamics, volatility, speculative nature, and reactions to economic policy fluctuations. The analysis underscores the transformation of bitcoin research, from its beginnings as a decentralized, privacy-oriented currency to its role in global economics and green financing, revealing a complex narrative of an innovative financial instrument to a multifaceted entity. Implications drawn from this analysis include the need for further research on the potential integration of bitcoin within emerging technologies like AI and cybersecurity, the implications of bitcoin’s interplay with traditional financial systems, and the environmental impacts of bitcoin and blockchain utilization. Overall, the current study not only enhances our understanding of the bitcoin field but also charts its dynamic evolution and stimulates further academic inquiry.

Study on Sound Transmission across a Floating Floor in a Residential Building by Using SEA

For the purpose of reducing the impact noise transmission across floating floors in residential buildings, two main sound transmission paths in the floating floor structure are considered: the stud path and the cavity path. The sound transmission of each path is analysed separately: the sound transmission through the cavity and the stud are predicted by statistical energy analysis (SEA). Then, the sound insulation prediction model of the floating floor is established. There is reasonable agreement between the theoretical prediction and measurement, and the results show that a resilient layer with low stiffness can attenuate the sound bridge effect, resulting in higher impact noise insulation. Then, the influences of the floor covering, the resilient layer and the floor plate on the impact sound insulation are investigated to achieve the optimised structure of the floating floor based on the sound insulation.

Research on the High-quality Development Strategy of Logistics Industry based on Green and Sustainable Development

The logistics industry is a fundamental industry that supports economic development and an important link in the supply chain. With the gradual expansion of the development scale of the logistics industry, a series of environmental problems such as excessive energy and resource consumption caused by the logistics industry have become more prominent, and the impact on the ecological environment has gradually deepened. The pursuit of green transformation in the logistics industry has become an inevitable choice for the industry to break through difficulties and achieve green and sustainable development. Therefore, this article analyzes the current development status of the logistics industry based on green and sustainable development, which is conducive to identifying and solving the problems in the process of green and sustainable development of the logistics industry. Starting from key links such as logistics industry planning, warehousing, transportation and distribution, it proposes the main path for high-quality development of the logistics industry based on green and sustainable development, thereby promoting the green transformation of the logistics industry, to achieve green and sustainable development and high-quality development of the logistics industry.

Evaluating emission reduction potential at the “30-60 Dual Carbon targets” over China from a view of wind power under climate change

Large-scale wind energy development is one of the main paths to achieving China's carbon peak and neutrality goals. How will the wind power and corresponding carbon abatement potential (CAP) in China change when China reaches the timing of its reduction carbon targets? This issue has not been well addressed. In this paper, a weighted multi-model ensemble with 14 global climate models from Phase 6 of the Coupled Model Intercomparison Project (CMIP6) is used to evaluate the spatio-temporal characteristics of wind speed over China during the baseline period (2004–2014). Then, we further analyze the changes in wind power and corresponding CAP due to the climate change over China in the two-level years (2030 and 2060) under the SSP2-4.5 and SSP5-8.5 scenarios. The results show that the wind capacity factor over China will have a trend of decreasing in most regions of China and increasing in the southeast in 2060. Overall, climate change will have a slight impact on the CAP of wind power in 2030, with an increase in some southern provinces. However, the CAP of wind power will decrease significantly in most regions of China in 2060 under the SSP2-4.5 scenario, especially in Shanxi, Inner Mongolia, Ningxia, and Liaoning, by more than 5 %. Under the SSP5-8.5 scenario, the CAP will decrease significantly in the southwest and northwest regions, such as Sichuan and Qinghai, by 9.86 % and 8.19 % respectively. Central and South provinces such as Hunan and Hubei will increase by about 5 %. In terms of seasonal changes, the CAP of wind power will decrease significantly in summer under the SSP2-4.5 scenario (about −5.24 %) and SSP5-8.5 scenario (about −6.50 %).These findings can help policymakers make decisions as they establish plans for wind power expansion while taking the effects of climate change into account as they work toward China's carbon neutrality goal.

A Method to Identify Main Paths of Knowledge Diffusion for Collaborative Innovation Projects

A Method to Identify Main Paths of Knowledge Diffusion for Collaborative Innovation Projects

Low-Complexity Joint Angle of Arrival and Time of Arrival Estimation of Multipath Signal in UWB System.

In an ultra-wideband (UWB) system, the two-dimensional (2D) multiple signal classification (MUSIC) algorithms based on high-precision 2D spectral peak search can jointly estimate the time of arrival (TOA) and angle of arrival (AOA). However, the computational complexity of 2D-MUSIC is very high, and the corresponding data model is only based on the dual antennas. To solve these problems, a low-complexity algorithm for joint AOA and TOA estimation of the multipath ultra-wideband signal is proposed. Firstly, the dual antenna sensing data model is extended to the antenna array case. Then, based on the array-sensing data model, the proposed algorithm transforms the 2D spectral peak search of 2D-MUSIC into a secondary optimization problem to extract the estimation of AOA via only 1D search. Finally, the acquired AOA estimations are brought back, and the TOA estimations are also obtained through a 1D search. Moreover, in the case of an unknown transmitted signal waveform, the proposed method can still distinguish the main path signal based on the time difference of arrival of different paths, which shows wider applications. The simulation results show that the proposed algorithm outperforms the Root-MUSIC algorithm and the estimation of signal parameters using the rotational invariance techniques (ESPRIT) algorithm, and keeps the same estimation accuracy but with greatly reduced computational complexity compared to the 2D-MUSIC algorithm.

Simulating tunable coherence for scattered light suppression in laser-interferometric gravitational wave detectors

Ground-based gravitational wave detectors use laser interferometry to realize ultra-precise displacement measurements between free-floating test masses to detect signals in the frequency band of 10 Hz to 10 kHz. Light scattered out of and back into the main beam path creates noise in these detectors that non-linearly up-converts low-frequency, out-of-band signals into the measurement band. This scattered light induced noise becomes more relevant as the sensitivity at lower frequencies is improved in current and future detectors. To suppress this noise source, we study how the strong spatial coherence of the laser light can be reduced to a few centimeters by introducing high-speed pseudo-random noise phase modulations into the Michelson interferometer topology. We simulate the interferometer signals in the presence of scattered light in the time domain. Our simulations show that tuning of the coherence can reduce the coupling of scattered light by orders of magnitude, and that the phase modulations are, in principle, compatible with resonant cavities that are employed in the complex interferometer topologies of modern detectors to achieve ultra-low quantum noise levels. We outline the currently expected limitations of this approach and discuss the applicability to detectors.