bluuebunny/crossref_metadata_2025 huggingface dataset:
Thoughts on Establishing Modern Enterprise System and Management Reform
Authors: Yu Wei
Published: February 2021

The establishment of modern enterprise system is not only the inevitable requirement of market economy, but also the difficulty and hot spot of enterprise reform in our country. With the continuous development of market economy and the deepening of reform and opening up, the establishment of modern enterprise system and the reform of enterprise management have become the inevitable trend of market economy development. This paper will comprehensively use the relevant theories, combined with the actual establishment of modern enterprise system and management reform to think and discuss.
Research on Telecom Operator’s Market Strategy Change from Virtual Value Chain View: Take Guangdong Telecom Company Limited as An Example
Authors: Guan Shan , Wang Xin
Published: February 2021

The rapid development of the Internet has drastically changed the competitive environment and the profit model of global telecommunications market. Virtual value chain is the information-based projection of value chain in the virtual world. It transcends the original one by creating new value in the value-adding process. This article studies the changes in Guangdong Telecom Company Limited’s market strategy from the perspective of virtual value chain, and allows telecom operators to take it as a reference for market strategies’ formulation. This article uses literature research method and case research method to draw conclusions that virtual value chain has helped Guangdong Telecom Company Limited establish new customer relationships, and the significance of virtual value chain is surpassing traditional value chain continually. Therefore, proper use of Internet-related technologies will help the long-term development of telecommunications industry.
Can Institutional Investor Clique Play a Governance Role? Based on the Perspective of Insider Reduction
Authors: Peng Yuxiang , Li Bingxiang
Published: February 2021

This article takes China’s A-share non-financial industry listed companies from 2007 to 2015 as a sample, starting from the social network algorithm, to study whether the grouping behavior of institutional investors in the network can affect the degree of executive reduction in the future. The study found that there is a significant positive correlation between the shareholding ratio of institutional investors in group holdings and the degree of future reduction of executives. This article explores the interactive behavior of Chinese institutional investors in the network, and expands the research of institutional investors on corporate governance and executives’ future reduction behaviors.
Research on the Industrial Economic Development Driving by Scientific and Technological Service System Innovation
Authors: Zhang Lan , Hao Xinhui , Zhang Yuhua , Wang Yonggeng
Published: February 2021

In terms of the mechanism of scientific and technological service promoting innovation and entrepreneurship, innovation can significantly improve labor productivity and labor factor efficiency, and promote the optimization and upgrading of industrial structure. Sustainable economic development must rely on technological innovation. This paper designs an innovative science and technology service system to achieve the goal of industrial economic development from five aspects: market-oriented mechanism, demand-oriented mechanism, industry university research collaborative innovation mechanism, scientific and technological financial system construction, and scientific and technological talent team construction.
The impact of servitization of manufacturing on the human capital
Authors: Chen LiXian
Published: February 2021

This paper uses the PSM-DID method to investigate the impact of servitization of manufacturing on enterprises’ human capital based on Chinese listed manufacturing corporations’ financial data. The empirical results show that servitization of manufacturing has a negative impact on the proportion of production and sales personnel, but has a positive influence on the proportion of technical personnel and highly educated personnel, which both by increasing path variables productivity and capital-intensity.
Environmental regulation, Industrial structure upgrading and Economic growth in Beijing Tianjin Hebei region
Authors: Li Menglu
Published: February 2021

This paper selects the panel data of 13 cities in Beijing Tianjin Hebei region from 2008 to 2016, and uses the fixed effect model to study the relationship between environmental regulation, industrial structure upgrading and economic growth in Beijing Tianjin Hebei region. The results show that: strengthening environmental regulation can promote the upgrading of industrial structure in Beijing Tianjin Hebei region by reducing the emission of pollutants; the upgrading of industrial structure is conducive to promoting the economic development of Beijing Tianjin Hebei region.
Research on Green Total Factor Productivity of Logistics Industry and its threshold effect of Environmental Regulation
Authors: Li Wanchun
Published: February 2021

This paper is based on the input-output panel data of logistics industry in 30 provinces and regions in China from 2005 to 2017, using nonparametric DEA model to evaluate the green total factor productivity of logistics industry, and build a panel threshold model to empirically test the nonlinear impact of environmental egulation. It is found that environmental regulation has a double threshold effect on green total factor productivity of logistics industry, the estimated threshold values are 89.85 and 211.27 respectively; when environmental regulation is at a low level below 89.85, environmental regulation has a positive effect of 2.09% on green total factor productivity of logistics industry, when environmental regulation is in the intermediate stage of 89.85 to 211.27, environmental regulation has a positive improvement effect of 6.41% on green total factor productivity of logistics industry; when environmental regulation is at a higher level than 211.27, environmental regulation has a negative inhibitory effect of 1.57% on green total factor productivity of logistics industry. Based on the empirical conclusion, this paper puts forward: First, using the performance assessment as the baton to urge the local government to establish an effective environmental regulation system; second, the government should plan to guide the green transformation and upgrading of the logistics industry to avoid “one size fits all” environmental regulation.
Technological Thoughts on Scientific and Technological Innovation Promoting Rural Rejuvenation
Authors: Mao Yaping
Published: February 2021

Scientific and technological innovation is the key to rural revitalization and development. As the most important industry of rural agriculture, technology supports the development and construction of agriculture. To strengthen the development of rural agriculture, technological innovation must be carried out so as to promote the continuous progress of agriculture, and ultimately lead the village to the road to prosperity. This article analyzes the strategy of scientific and technological innovation to promote rural revitalization, and proposes key strategies as a reference to help rural agriculture achieve development and progress and lead rural people to a well-off life.
Local government debt risk measurement and early warning structural system building — Research Based on KMV and TOPSIS Models
Authors: Zhang Rongzhou , Shi Ruoyu , Li Cheng
Published: February 2021

In this paper, by using the Statistical analysis Software SPSS20, 30 and Cities of our country’s local government structural debt risk has been carried on the empirical analysis, using the entropy weight method to determine the specific weight of each index, reduced the subjective factors of influence on the result of the index weight distribution, expectations of local government debt defaults and the situation of the comprehensive evaluation index of local government debt. By comparing the size of the threshold value, to determine the risk of local government debt, the results show that in 7 provinces and cities in China are in the state of no warning of local debt risk, in 10 provinces and cities are in the state of mild warning. Means and Cities are in the State of Moderate warning, In other words, it means it’s time to generate the risk of local government debt. In the State of high warning, most means and cities need to take scientific measures to generate the risk of local government debt.
Theorizing the moderating roles of perceived service fairness and self-congruence on the relationship between experiential marketing, customer citizenship behavior and brand loyalty
Authors: Wang Zichen
Published: February 2021

In such a fierce market competition, brand loyalty and the extent to which consumers participate in the corporate value chain cycle are even more important. At present, scholars’ research on customer behavior and brand loyalty are still relatively limited. Therefore, the purpose of this article is to use the subjective well-being and brand identity as the mediators, the perceived service fairness as the roles of moderating to explore the experiential marketing, probing into a relationship between the customer citizenship behavior and the brand loyalty to build a research framework as the basis for subsequent empirical research.
A Study on Harmonious Rural Tourism Environment Under the Construction of the Socialism New Rural
Authors: Tang Boyan
Published: February 2021

Rural environment is the base for the development of rural tourism. At the construction of socialism new rural, the rural tourism environment has been turned to a radical change. The paper analysed from the meaning and the composing of ruroal tourism environment, applyed to discuss the changes and the characcteristics of harmonious rural tourism environment under the construction of socialism new rural, and wish to advance the development of harmonious rural tourism.
The Effect of Information Communication Technology (ICT) Infrastructure availability on FDI inflow in D8 Countries
Authors: Wang Peizhi , Gul Rukh Bangash
Published: February 2021

This This paper analyzes the effect of ICT infrastructure availability on FDI inflow in D8countries (Bangladesh, Indonesia, Iran, Egypt, Nigeria, Malaysia, Pakistan and Turkey). Panel data for the period 1997-2018 has been used and the analysis has been done using the fix effect model suggested by Hausman specification test. The result shows positive and significant effect between ICT infrastructure and FDI inflows, along with other controlling variables like market size, trade openness, in case of macroeconomic variable that is exchange rate it has negative but significant effect on FDI inflows.
The Influence of Technological Innovation on the Profitability of Enterprises
Authors: Li Shasha
Published: February 2021

This paper studies whether the investment intensity of R&D expenses of listed companies can improve the profitability of enterprises. The data indicators of listed companies from 2015 to 2017 are obtained by using CSMAR database. R&D investment is divided into two indicators: relative number index and absolute number index, and regression analysis is carried out by establishing the econometric analysis model of profitability and absolute number index and relative number index of R&D investment. It is found that the intensity of R&D investment has a positive effect on the profitability of enterprises. Therefore, enterprises can improve their profitability through technological innovation and increasing R&D investment.
Research on the effectiveness of education and training incentive mechanism to promote college students’ Entrepreneurship
Authors: Zhang Chenyu , Zhao Lei , Liang Xiao , Li Jun
Published: February 2021

This paper mainly uses the methods of expert interview and questionnaire survey to collect and sort out the data and data of College Students’ entrepreneurship education and training, and then carries out statistical analysis through SPSS and Excel software.Through the analysis, it is found that college students’ entrepreneurship is closely related to entrepreneurship education, government entrepreneurship policies and measures, and college students’ entrepreneurial activities. As the situation of college students is not consistent every year, the relevant entrepreneurial background is not the same. Only by constantly improving the entrepreneurship education policies and related measures to make them more in line with the actual situation of college students, can the entrepreneurship education policies and related measures better serve college students, thus promoting college students to enter the ranks of entrepreneurship and achieve success.
Research on Influencing Factors of Export Complexity of Chinese High-tech Industry Based on Big Data Analysis
Authors: Wang Junsheng , Ziqi Zhong , Wang Haoran
Published: February 2021

Export trade can measure the economic level of a country, but it can only reflect the amount of exports, but not the quality of exported products and the technical content of exported products. Therefore, domestic and foreign scholars have begun to study the complexity of export technology. The development of big data technology makes it possible to analyze the export complexity using big data analysis technology. With the rapid development of high-tech industries represented by high-end manufacturing, there is more and more research on the export of high-tech industries. Based on the existing research results, this article first introduces the current export profile of high-tech products and explains the concept of export complexity. Then, the flow of big data analysis was sorted out. Finally, this paper theoretically analyzes the influence of industrial agglomeration on industrial export complexity, and uses big data analysis and regression verification. The results show that industrial agglomeration has a significant role in promoting the export complexity of China’s high-tech products.
The Impact of Fund Holdings on the Real Activities Earnings Management
Authors: Ma Mengyuan
Published: February 2021

After 20 years of development, the impact of Fund holdings in corporate governance has also received more and more attention. This paper analyzes the governance effect of fund holdings from the perspective of real activities earnings management, and considers the nature of the firm and the impact of the fund industry reform in 2012. This paper took the data of a-share listed companies from 2006 to 2017 as the sample, referred to the model Roychowdhury used to measure the level of real activity earnings management, and used multiple linear regression method for empirical analysis. The findings are as follows: fund holdings have a significant inhibitory effect on real earnings management; when considering the nature of enterprises, the inhibiting effect is more significant in non-state-owned enterprises, but not in state-owned enterprises; when considering the fund industry changes in 2012, this inhibition is more pronounced after the change. The above results show that the fund can exert its earnings management governance effect by supervising the management and restricting the major shareholders. The state-owned enterprise nature will limit its governance effect, and the fund industry standard development and active guidance will strengthen its governance effect.
Research on the construction of smart supply chain system under the background of supply side reform
Authors: Cao Yonghui , Jiang He
Published: February 2021

At present, China’s economy has entered a new period of high-quality development from the stage of high-speed growth. The supply side structural reform focusing on removing production capacity, inventory, deleveraging, cost reduction and making up for weaknesses is a major strategic measure to enhance the driving force of sustained economic growth, solve the deep-seated problems of economic development and improve the quality of economic development. Accelerating the innovation and application of smart supply chain has become an important part of promoting supply side structural reform, cultivating new economic growth points and building a modern economic system. This paper mainly analyzes the emergence and research status of smart supply chain and the construction of smart supply chain system under the background of supply side reform, so as to promote the high-quality development of economy.
Analysis on the “Douyin (Tiktok) Mania” Phenomenon Based on Recommendation Algorithms
Authors: Zhao Zhengwei
Published: February 2021

As one of the most popular short video platform, Douyin has accumulated more than half of the Chinese netizens as its daily active users. Many users spend plenty of time viewing Douyin short videos, which make Douyin addiction become a widespread phenomenon. In this paper, the author analyzes algorithm principles used in Douyin. Combining both perspectives of mass media communication and algorithm technology to explain how it effects Douyin addiction. For one thing, the recommendation algorithm caters users by fully meeting their needs. Using the hierarchical interest label tree, the user persona and the partitioned data buckets strategy to recommend more accurate and personalized contents. For another, the algorithm uses the collaborative filtering algorithm and low-cost interaction design mechanism to make traps for users. The author also finds that there is a closed-loop relationship between Douyin addiction and algorithm optimization. The algorithm principles positively effects users’ continuance intention. Meanwhile, the more frequent the user uses Douyin, the more accurate the algorithm will be. If not intervened, the addiction may be severely exacerbated. So, the author comes up with a few suggestions for Douyin developers and users, trying to break the closed-loop.
Research on the Development of Internet Insurance in China ——Based on the exploration of the road of Huize insurance
Authors: Jing Tian
Published: February 2021

In 2020, Huize insurance came to the market in the United States, which will again push the Inter net insurance industry to the peak of social concern. As the one of three pillars of the financial industry, the Internet insurance industry is generated with the promotion of Internet finance. After experiencing a blowou t growth around 2015, the Internet insurance industry bypassed the monopoly of traditional insurance indust ry, At that time, big and small companies had their own characteristics. But as the policy tightens, Internet i nsurance suffers. With the impact of the epidemic in 2020, people’s insurance awareness is constantly streng thened, and the Internet insurance industry will usher in a spring with its unique advantages. This paper com prehensively reviews the development of Internet insurance, analyzes the main problems of the Internet ind ustry, and put forward development recommendations based on Huize’s business model, explore methods th e Internet industry in the social sense of responsibility, product design, and connect with the epidemic, comb ine with the government, to strengthen the construction of preferential and universal insurance, innovate the PPP mode, combine insurance technology to carry on the prospect.
Research on the Development Status and Countermeasures of Network Economy in China
Authors: Gao Hang
Published: February 2021

With the rapid development of information technology, the rapid rise of the network economy has promoted the vigorous development of China’s economy and become an important part of the national economy. The nature of the Internet, which spans regions and spreads quickly, has driven the transaction of products to be low-cost and efficient. These characteristics have exerted profound influence on the industrial structure in many aspects. Network economy not only changes the production mode of society through resource sharing and information exchange, but also promotes the development of social civilization. This paper analyzes the current situation of network economy and its impact on China’s economic and social development, and puts forward countermeasures to promote the development of network economy.
Research on digital economy boosting the transformation and upgrading of traditional industries in Foshan City
Authors: Jiang He , Cao Yonghui
Published: February 2021

For a large number of traditional industries, digital transformation is an all-round, multi angle and whole chain transformation process using digital technology. In recent years, Foshan has made some progress in Internet technology, industry, application and cross-border integration, and has become the only pilot city for comprehensive reform of manufacturing transformation and upgrading in China. However, for the traditional industries, the constraints of resources and energy, the increasing pressure of ecological environment, the gradual decline of demographic dividend and other factors restrict economic development to meet challenges. By deepening the application of digital technology in production, operation, management and marketing, it is an important way to realize the digital, network and intelligent development of enterprises and industries, and constantly release the amplification, superposition and multiplication effect of digital technology on economic development. It is an important way to realize the quality change, efficiency change and dynamic change of traditional industries. This is also the only way to promote high-quality economic development. In this paper, through the exploration of informatization and digitization to promote the transformation and upgrading of traditional industries in Foshan City and the realization of the path, it is of great significance for the sustainable development of high-quality economy in Foshan City.
Application of Blockchain Technology in Commercial Banks
Authors: He Qingquan
Published: February 2021

Blockchain technology is widely used in finance, digital asset trading and other fields because of its characteristics of decentralization, unforgeability and sharing. Blockchain has become one of the hot topics in fintech research, which affects the development of traditional financial formats. It is considered as the cornerstone of digital economy. This paper systematically analyzes the characteristics of blockchain technology, the impact of blockchain technology on the operation and management of traditional commercial banks, and prospects the application of blockchain technology in commercial banks.
Research on Financial Internal Control Optimization of Accounting Firms Based on Information Management Technology
Authors: Liu Ping , Wang Wenbo
Published: February 2021

With the advent of the information age, the information management technology of all walks of life is improving day by day, and Chinese economic development has entered a brand new mode. Therefore, enterprises also need to keep pace with the times and carry out appropriate changes and reforms in their internal control management. As intermediary organizations connecting the government and enterprises, accounting firms are the bridges between the owners and operators of enterprises. Therefore, they have strong independence and objectivity. However, due to the short rise of accounting firms in China, the research on accounting firms in China is limited, and the scale is mainly small and medium-sized. As a monitoring method, internal control can effectively avoid the risks existing in the development process of small and medium-sized accounting firms in China, and effectively supervise the working ability and moral level of their auditors. Therefore, under the perspective of informational environment, this paper makes a brief analysis of the problems and causes existing in the establishment of the internal control system of accounting firms in China based on the study of the relationship between financial internal control and accounting firms. Meanwhile, a series of solutions to these problems have been developed in order to provide some effective reference basis for future research and promote the transformation and reform of the financial internal control of accounting firms in China.
Le contrôle non destructif, de la médecine à l’industrie
Authors: Hassnaoui Yonas
Published: February 2021

Le contrôle non destructif (CND), qui a pour objectif d’évaluer un matériau sans en altérer la structure, n’est pas uniquement employé dans le secteur nucléaire. Mais celui-ci, par ses exigences de sûreté particulièrement élevées, dispose d’un savoir-faire exceptionnel dont les autres industries bénéficient pleinement.
Rural - urban income gap and labour market in Romania
Authors: Băncescu Irina
Published: February 2021

Rural – urban income gap is an important social-economic development indicator for a society. A large rural - urban income gap within a society reveals a split of it into two distinct societies, one extremely poor compared to the other. In Romania, almost half of the resident population lives in rural areas (46.02% in 2019), while the urban-rural migration flow is higher than the traditional reverse flow since 1997. However, the country is characterized by regional economic disparities, Bucharest-Ilfov region being the most economically developed. Labour market in rural areas is underdeveloped, rural population being highly depended on subsistence agriculture. Furthermore, rural areas have a low level of income and living standards. In this paper, we analysis the rural-urban labour market dynamics and rural-urban income gap using a LMDI (logarithmic mean Divisia index) decomposition for 2005-2019 period. Factors such as income gap effect and structural rural income effect are considered. Results show that the total urban–rural income gap has decreased with 8.91%, while structural rural income effect contributed with an increase of only 0.63%, the income gap effect (of different employed population groups) being of -9.49%.
The comparative sensory analysis of mint honey
Authors: Augustin (Zugravu) Constanta Laura , Turek Rahoveanu Maria Magdalena , Zugravu Gheorghe Adrian
Published: February 2021

The aim of the paper is to present sensory analysis of mint honey as a component of the promotion strategy of intensive beekeeping. Sensory analysis is part of the quality concept and is the method of examining a product with the help of basic human sensation.
RHOBTB2 p.Arg511Trp Mutation in Early Infantile Epileptic Encephalopathy-64: Review and Case Report
Authors: Fonseca Jacinta , Melo C. , Ferreira C. , Sampaio M. , Sousa R. , Leão M.
Published: February 2021

Early infantile epileptic encephalopathy-64 (EIEE 64), also called RHOBTB2-related developmental and epileptic encephalopathy (DEE), is caused by heterozygous pathogenic variants (EIEE 64; MIM#618004) in the Rho-related BTB domain-containing protein 2 (RHOBTB2) gene. To date, only 13 cases with RHOBTB2-related DEE have been reported. We add to the literature the 14th case of EIEE 64, identified by whole exome sequencing, caused by a heterozygous pathogenic variant in RHOBTB2 (c.1531C > T), p.Arg511Trp. This additional case supports the main features of RHOBTB2-related DEE: infantile-onset seizures, severe intellectual disability, impaired motor functions, postnatal microcephaly, recurrent status epilepticus, and hemiparesis after seizures.
Seizure Semiology in Focal and Generalized Epilepsies: Distinctive and Overlapping Features
Authors: Marashly Ahmad
Published: February 2021

Studying seizure semiology is the first step in evaluating any patient with epilepsy which leads the way to further investigations and management, particularly in differentiating focal and generalized epilepsies. While the usefulness of semiological analysis has been confirmed through decades' worth of research and clinical practice, there remains some instances when the line between focal and generalized semiological features is blurred leading to difficulties identifying the type of epilepsy at hand. This in turn can lead to delayed or wrong diagnoses with significant implications.In this review article, we explain the role of semiology in epilepsy, specifically in differentiating focal versus generalized epilepsies and cover the semiological features for both groups. We also discuss the occasional overlapping semiology between the two groups and provide case examples.
Embryology of the Orbit
Authors: Cho Raymond I. , Kahana Alon
Published: February 2021

The orbit houses and protects the ocular globe and the supporting structures, and occupies a strategic position below the anterior skull base and adjacent to the paranasal sinuses. Its embryologic origins are inextricably intertwined with those of the central nervous system, skull base, and face. Although the orbit contains important contributions from four germ cell layers (surface ectoderm, neuroectoderm, neural crest, and mesoderm), a significant majority originate from the neural crest cells. The bones of the orbit, face, and anterior cranial vault are mostly neural crest in origin. The majority of the bones of the skull base are formed through endochondral ossification, whereas the cranial vault is formed through intramembranous ossification. Familiarity with the embryology and fetal development of the orbit can aid in understanding its anatomy, as well as many developmental anomalies and pathologic conditions that affect the orbit.
High-energy x-ray nanotomography introducing an apodization Fresnel zone plate objective lens
Authors: Takeuchi Akihisa , Uesugi Kentaro , Uesugi Masayuki , Toda Hiroyuki , Hirayama Kyosuke , Shimizu Kazuyuki , Matsuo Koichi , Nakamura Takashi
Published: February 2021

In this study, high-energy x-ray nanotomography (nano-computed tomography, nano-CT) based on full-field x-ray microscopy was developed. Fine two-dimensional and three-dimensional (3D) structures with linewidths of 75 nm–100 nm were successfully resolved in the x-ray energy range of 15 keV–37.7 keV. The effective field of view was ∼60 µm, and the typical measurement time for one tomographic scan was 30 min–60 min. The optical system was established at the 250-m-long beamline 20XU of SPring-8 to realize greater than 100× magnification images. An apodization Fresnel zone plate (A-FZP), specifically developed for high-energy x-ray imaging, was used as the objective lens. The design of the A-FZP for high-energy imaging is discussed, and its diffraction efficiency distribution is evaluated. The spatial resolutions of this system at energies of 15 keV, 20 keV, 30 keV, and 37.7 keV were examined using a test object, and the measured values are shown to be in good agreement with theoretical values. High-energy x-ray nano-CT in combination with x-ray micro-CT is applied for 3D multiscale imaging. The entire bodies of bulky samples, ∼1 mm in diameter, were measured with the micro-CT, and the nano-CT was used for nondestructive observation of regions of interest. Examples of multiscale CT measurements involving carbon steel, mouse bones, and a meteorite are discussed.
Optimization of x-ray emissions with Gd + Au + Gd sandwich design
Authors: Li Liling , Jiang Shaoen , Li Hang , Zheng Jianhua , Jing Longfei , Zhang Lu , Lin Zhiwei , Kuang Longyu , Yang Dong , Wang Feng , He Haien , Yang Jiamin , Zhang Baohan
Published: February 2021

The x-ray emissivity of gadolinium (Gd) and gold (Au) has been studied using the FLYCHK code. The results show that the Gd M-band is lower than 2 keV and that Gd has a higher x-ray emissivity at low temperature. Thus, we proposed a Gd + Au + Gd sandwich design to improve the x-ray conversion efficiency (CE). Under a laser intensity of 1 × 1015 W/cm2, a 11%–17% enhancement of the CE and an optimized x-ray spectrum were achieved in one-dimensional simulation. The enhancement of the CE is mainly due to an enhancement of the soft x-ray flux (0 keV–2 keV). In addition, the high energy x-ray flux (2 keV–5 keV) is lower than that of Au. Particularly at an early stage, the laser ablates the Gd layer, and the temperature of the Au layer is insufficient for producing an M-band emission. Thus, the high energy x-ray flux is rather low. A sandwich design not only takes advantage of the higher x-ray emissivity of Gd under specific conditions in an efficient manner but also simplifies the target fabrication, which is important. In addition, Gd can also be used to optimize the future design of depleted uranium Hohlraum.
Microtearing instabilities and electron thermal transport in low and high collisionality NSTX discharges
Authors: Rafiq T. , Kaye S. , Guttenfelder W. , Weiland J. , Schuster E. , Anderson J. , Luo L.
Published: February 2021

Microtearing mode (MTM) real frequency, growth rate, magnetic fluctuation amplitude, and resulting electron thermal transport are studied in systematic NSTX scans of relevant plasma parameters. The dependency of the MTM real frequency and growth rate on plasma parameters, suitable for low and high collision NSTX discharges, is obtained by using the reduced MTM transport model [T. Rafiq et al., Phys. Plasmas 23, 062507 (2016)]. The plasma parameter dependencies are compared and found to be consistent with the results obtained from MTM using the gyrokinetic GYRO code. The scaling trend of collision frequency and plasma beta is found to be consistent with the global energy confinement trend observed in the NSTX experiment. The strength of the magnetic fluctuation is found to be consistent with the gyrokinetic estimate. In earlier studies, it was found that the version of the multi-mode (MM) anomalous transport model, which did not contain the effect of MTMs, provided an appropriate description of the electron temperature profiles in standard tokamak discharges and not in spherical tokamaks. When the MM model, which involves transport associated with MTMs, is incorporated in the TRANSP code and is used in the study of electron thermal transport in NSTX discharges, it is observed that the agreement with the experimental electron temperature profile is substantially improved.
Over-critical sharp-gradient plasma slab produced by the collision of laser-induced blast-waves in a gas jet: Application to high-energy proton acceleration
Authors: Marquès J.-R. , Loiseau P. , Bonvalet J. , Tarisien M. , d'Humières E. , Domange J. , Hannachi F. , Lancia L. , Larroche O. , Nicolaï P. , Puyuelo-Valdes P. , Romagnani L. , Santos J. J. , Tikhonchuk V.
Published: February 2021

Generating thin and high density plasma slabs at a high repetition rate is a key issue for ultra-high intensity laser applications, such as plasma photonics, electron acceleration by few laser-cycle pulses, or collisionless shock acceleration of protons to high energies. In this paper, we present a scheme to generate such plasma slabs. It is based on the propagation and collision in a gas jet of two counter-propagating blast waves (BWs). Each BW is launched by a sudden and local heating induced by a nanosecond laser beam that propagates along the side of the jet. The resulting cylindrical BW expands perpendicular to the beam. The shock front, which is bent by the gas jet density gradient, pushes and compresses the plasma toward the jet center. By using two parallel ns laser beams, one on each side of the gas jet, this scheme enables us to tailor independently two opposite sides of the jet, while avoiding the damage risks associated with counterpropagating laser beams. A parametric study is performed using two and three dimensional hydrodynamic (single fluid), as well as kinetic (Fokker–Planck), simulations. This study shows that the BW bending combined with the collision in a stagnation regime increases the density by more than ten times and generates a very thin (down to few micrometers), near to over-critical plasma slab with a high density contrast (>100) and a lifetime of a few hundred picoseconds. Two dimensional particle-in-cell simulations are, then, used to study the influence of the plasma tailoring on proton acceleration by a high-intensity sub-picosecond laser pulse. It is shown that tailoring the plasma, not only at the entrance but also at the exit side of the picosecond-pulse, enhances the proton beam collimation and increases significantly the number of high energy protons, and their maximum energy.
Non-inductive plasma current ramp-up through oblique injection of harmonic electron cyclotron waves on the QUEST spherical tokamak
Authors: Onchi T. , Idei H. , Fukuyama M. , Ogata D. , Ashida R. , Kariya T. , Ejiri A. , Matsuzaki K. , Osawa Y. , Peng Y. , Kojima S. , Watanabe O. , Hasegawa M. , Nakamura K. , Kuroda K. , Ikezoe R. , Ido T. , Hanada K. , Bertelli N. , Ono M. , Fukuyama A.
Published: February 2021

The plasma current is ramped up primarily by a 28 GHz electron cyclotron wave (ECW) in the Q-shu University experiment Steady-State Spherical Tokamak (QUEST), with multiple harmonic resonance layers from the second to the fourth stay in the plasma core. A steering antenna comprising two quasi-optical mirrors enhances the power density of ECWs. The ECW beam is injected obliquely from the low-field side where the parallel refractive index is N∥ = 0.75 at the second-harmonic resonance layer. Analysis of the resonance condition has found that energetic electrons moving forward along the magnetic field resonate more effectively than those moving backward. Such symmetry breaking is consistent with the results of the current ramp-up experiment. The peak plasma current reaches Ip>70 kA, constantly injecting a beam of radio frequency power of 100 kW. Ray-tracing by the TASK/WR code demonstrates that the power of the 28 GHz extraordinary mode is absorbed by energetic electrons via single-pass cyclotron absorption.
Electronic structure and thermoelectric properties of half-Heusler alloys NiTZ
Authors: Jaishi Dhurba R. , Sharma Nileema , Karki Bishnu , Belbase Bishnu P. , Adhikari Rajendra P. , Ghimire Madhav P.
Published: February 2021

We investigated the electronic and thermoelectric properties of half-Heusler alloys NiTZ (T = Sc and Ti; Z = P, As, Sn, and Sb) having an 18 valence electron count. Calculations were performed by means of density functional theory and the Boltzmann transport equation with constant relaxation time approximation, validated by NiTiSn. The chosen half-Heuslers were found to be indirect bandgap semiconductors, and the lattice thermal conductivity was comparable with the state-of-the-art thermoelectric materials. The estimated power factor for NiScP, NiScAs, and NiScSb revealed that their thermoelectric performance can be enhanced by an appropriate doping rate. The value of ZT found for NiScP, NiScAs, and NiScSb is 0.46, 0.35, and 0.29, respectively, at 1200 K.
Buffer layer engineering of L1 FePd thin films with large perpendicular magnetic anisotropy
Authors: Wang Xinjun , Krylyuk Sergiy , Josell Daniel , Zhang Delin , Lyu Deyuan , Wang Jian-Ping , Gopman Daniel B.
Published: February 2021

Development of L10 FePd thin films with large bulk perpendicular magnetic anisotropy and a low damping constant may permit superior scaling of next-generation ultra-high density magnetic memory elements. The buffer layer influences the L10-order parameter, static and dynamic magnetic properties of FePd and demands consideration for the design of high anisotropy strength and low damping films. In this report, we systematically investigate the perpendicular magnetic anisotropy and damping constant of the FePd thin films engineered through the Cr/(Pt, Ru, Ir, Rh), Mo/Ir, and Ir buffer layers. We observed that the Ir(001), Cr(001)/Ir(001), Cr(001)/Pt(001), Cr(001)/Rh(001), and Cr(001)/Ru(001) buffer layers can induce highly oriented (001) FePd films while the Mo/Ir buffer layer does not. Of all the buffer layers, the largest perpendicular magnetic anisotropy Ku ∼ 1.2 MJ/m3 and damping constant α ∼ 0.005 were achieved for the Cr/Pt buffered FePd sample, consistent with a high ordering parameter S ∼ 0.82. The Cr/Ru buffered FePd sample shows the lowest α ∼ 0.008, despite having a lower S ∼ 0.64 and a lower Ku ∼ 0.9 MJ/m3. These film-level properties would be sufficient for the engineering of devices that require thermally stable, sub-10 nm lateral size elements with low damping for applications of low energy-delay magnetic memory devices.
Broadband optical absorption enhancement in hybrid organic–inorganic perovskite metasurfaces
Authors: Wang Chenzhe , Zhang Zhifeng
Published: February 2021

The hybrid organic–inorganic perovskite (HOIP) becomes a promising candidate for ultra-thin photoelectric batteries and skin-like sensors. However, homogeneous thin films of the material usually provide low absorption efficiency. In this work, by engineering the nanohole arrays on a HOIP ultrathin film, we successfully design an all-dielectric HOIP metasurface with broadband optical absorption enhancement through the finite-difference time-domain technique. The absorption enhancement arises from the Mie resonance, which can be tuned by varying the geometrical parameters and the spatial periodicity of the nanoholes. Compared with a uniform HOIP film, the HOIP metasurface significantly enhances the absorption over the entire visible regime, and the maximum absorption rate reaches 90%. Moreover, our design with multiple nanohole sizes provides consistently high absorption efficiency up to 51%–87% in a broad wavelength range of 400 nm–770 nm. Furthermore, the external quantum efficiency of a solar cell with our HOIP metasurface is 44% higher than that of a uniform HOIP film by assuming the ideal process with infinite carrier lifetime and negligible recombination. Our findings may provide a route for effective light trapping and efficient photoelectric conversion with ultrathin HOIP metasurfaces.
Effect of surface modification treatment on top-pinned MTJ with perpendicular easy axis
Authors: Honjo H. , Naganuma H. , Nguyen T. V. A. , Inoue H. , Yasuhira M. , Ikeda S. , Endoh T.
Published: February 2021

We investigated the effects of surface modification treatment (SMT) on the perpendicular magnetic anisotropy (PMA) and the thermal tolerance of top-pinned magnetic tunnel junctions (MTJs) with a Co/Pt synthetic ferrimagnetic coupling reference layer. Applying an SMT to the bottom Pt layer increased the PMA of the overlying Co/Pt multilayer. X-ray diffraction spectrum analysis revealed that the SMT resulted in a higher crystallinity and smaller lattice spacing in the Co/Pt multilayer in the thinner bottom Pt layer, which may have increased the PMA in the Co/Pt multilayer. The tunnel magnetoresistance (TMR) ratio of the MTJ with SMT increased as the annealing temperature was increased up to 400 °C; conversely, the TMR ratio of the MTJ without SMT decreased at an annealing temperature of 400 °C. Evaluation of the m-H loops revealed that, after annealing at 400 °C, the reference layers in the MTJs after SMT possessed better magnetic properties than those in the MTJs without an SMT; this is attributable to the higher PMA of the reference layers with SMT. EDX line analysis revealed that SMT suppressed Pt diffusion to the MgO barrier, resulting in a higher thermal tolerance and larger PMA of the reference layer.
Study of structural, transport and magneto-crystalline anisotropy in La1−xSrxMnO3 (0.30 ≤ x ≤ 0.40) perovskite manganites
Authors: Channagoudra Ganesha , Gupta Shalabh , Dayal Vijaylakshmi
Published: February 2021

In this paper we present structural, transport, magnetic and magneto-crystalline anisotropy of La1−xSrxMnO3 (х = 0.30, 0.33, 0.36, and 0.40) synthesized using the solid-state reaction method. The X-ray diffraction pattern of the samples is well indexed to the rhombohedral structure with R3̄c space group. Lattice parameters and unit cell volume are found to decrease monotonically upon increasing Sr2+ concentration at La3+ site. X-ray photoelectron spectroscopy confirms the presence of Mn4+ and Mn3+, the ratio of which (Mn4+/Mn3+) increases from 0.44 to 0.64 with increasing Sr2+ concentration. From the ρ(T) and M(T) data analysis, we find that TMI and MS are larger for x = 0.33 composition, suggesting a weakening of the double-exchange interaction due to competing super-exchange interactions in x = 0.30, 0.36 and 0.40 samples. We calculated MCA constant (K1) by fitting the saturation magnetisation data at a higher magnetic field using the law of approach model, M = MS [1-a/H-b/H2]-χH with K12 = (105/8)bMs2 and is in the order of 105 erg/cm3.
Detailed analytical modeling for electromagnetic performance in actively shielded superconducting machines
Authors: Shin Kyung-Hun , Bang Tae-Kyoung , Choi Jang-Young , Cho Han-Wook , Haran Kiruba S.
Published: February 2021

This study presents detailed analytical modeling for electromagnetic performance analysis of actively shielded superconducting machines with air-cored slotless armatures. An actively shielded superconducting machine is composed of a type of nonmagnetic material to prevent saturation of the magnetic flux path, as the field coil has a high magnetic field, and a shield coil is installed on the outside for magnetic shielding. This study presents an analytical modeling technique that considers not only the distribution of armature coils with distributed windings but also the shapes of the field and shield coils. Analytical solutions for each domain are derived using electromagnetic theory, partial differential equations, and boundary conditions. Based on the analytical solutions, electromagnetic performances are analyzed. The analysis results obtained from the proposed analytical method are verified by comparing them with those of finite element analysis.
What does climate change have to do with bushfires?
Authors: Jalaludin Bin , Morgan Geoffrey G.
Published: February 2021

A warming climate is increasing the duration of fire seasons and the risk of more extensive and intense bushfires. The Black Summer bushfires that occurred in Australia from September 2019 to early February 2020 were unprecedented in their scale and intensity. The fires led to loss of lives and homes, and widespread destruction of flora, fauna and ecosystems. Dense smoke from these catastrophic fires blanketed major cities and towns for weeks. A Commonwealth Royal Commission and two state inquiries provided recommendations for reducing the risk of future bushfires and for better disaster management processes to support the preparedness, relief, response and recovery to such megafires. While strategies to reduce the risk of bushfires and the damage to our biota and ecosystems are necessary and important, there is also an urgent need for mitigation strategies to reduce or prevent emission of greenhouse gases. If we are to minimise the planetary effects of a warming climate, we need to limit global warming to well below 2°C compared to pre-industrial levels and to reach net zero carbon emissions by 2050. This requires transformative thinking and action by our political leaders that builds on the Australian public and industry’s willingness to play their part.
Evolutionary dynamics at the tumor edge reveal metabolic imaging biomarkers
Authors: Jiménez-Sánchez Juan , Bosque Jesús J. , Jiménez Londoño Germán A. , Molina-García David , Martínez Álvaro , Pérez-Beteta Julián , Ortega-Sabater Carmen , Honguero Martínez Antonio F. , García Vicente Ana M. , Calvo Gabriel F. , Pérez-García Víctor M.
Published: February 2021

Significance

Through the use of different in silico modeling approaches capturing tumor heterogeneity, we postulated that areas of high metabolic activity would shift toward the periphery as tumors become more aggressive. To confirm the hypothesis and provide clinical value for the finding, we collected
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F-FDG PET images of breast cancers and non–small-cell lung cancers, where we measured the distance from the point of maximum activity to the tumor centroid, normalizing it by a surrogate of the volume. The metric, NHOC, showed higher prognostic value than other classical PET-based metabolic biomarkers used in oncology, evidencing that the shift of the hotspot of activity from the center of the tumor to its periphery correlates with a poor prognosis.