bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the difference of Digital inclusive Finance-based on Multi-index Panel data clustering
Authors: Zhang Jinmin , Li Xufang , Fan Dijun
Published: June 2021

Objective: to understand the development level of digital inclusive finance in 31 provinces in China in recent years, so that the areas with poor development level can speed up the development. Methods: the data of Peking University Digital inclusive Financial Index from 2012 to 2018 were collected, and the optimal clustering number was determined, and then the cross-sectional data and multi-index panel data were clustered respectively. Conclusion: the level of digital inclusive finance in China shows an upward trend as a whole, but there are great differences in the development level of digital inclusive finance among 31 provinces in China, in which East China is the best, South China and Central China have a better overall development level, and North China, Northwest, Southwest and Northeast are poor in overall development level, but have provincial differences.
Analysis on the Change of Financial Management Mode under Internet Finance
Authors: Liu Jia
Published: June 2021

Economic development in the 21st century in the 21st century, the wealth in the people’s hands has been accumulated continuously, and the increase of the wealth in the people’s hands has also promoted the emergence of new industries ——— financial management in our country. Because of the rapid development of Internet in China, all kinds of industries begin to combine with the Internet, and the financial industry is no exception. The combination of financial industry and Internet has produced the hottest industry ——— Internet finance in China. Internet finance not only brings innovation to the traditional financial industry, but also makes the financial management mode of our country change dramatically.
On the Prospects of the Development of Non-public Ownership Economy under the Background of Big Data
Authors: Jia Manli
Published: June 2021

This article analyzes the interaction between big data and the non-public economy. The author studied the problems faced in the deep fusion process. The research content of this paper includes data source activation, data cleanup, hidden dangers of data content, shortage of talents for analysis, and development of integrated platforms. The author analyzes how to establish a comprehensive development platform, improve the in-depth integration model, enhance the awareness of data application, do a good job in personnel training, improve the safety management mechanism, optimize the resource development environment, and do a good job in market supervision and management. The purpose of this article is to speed up the integration of big data and the non-public economy, and promote the development of enterprise economy.
Development Model of Business Management Based on Big Data
Authors: Xie Zhongtian
Published: June 2021

In recent years, with the continuous development of network information technology, a large amount of data information has gradually appeared in real life. One of the most obvious examples is the new data management development model based on big data. In the context of big data, e-commerce has developed rapidly, and products and services have become more diverse. However, at the same time, there are many problems, such as insecurity of user information, increasing differences in transactions, and lack of management strategies. This article mainly introduces how to solve existing problems and make business management more suitable for the arrival of the big data era. This article uses bibliographic analysis, benchmark analysis, graphical analysis and case analysis to conduct an in-depth discussion on theoretical research and commercial applications of big data. Classify and divide ubiquitous different types and irregular massive data, and propose different big data solutions according to different categories. Finally, a complete set of big data management model was established to verify the feasibility of the big data management model. Big data has increased the efficiency of business management by nearly 30%.
Study on the relationship between Word Preference and Stock Returns under the background of intelligent information
Authors: Li Yunhong
Published: June 2021

Based on intelligent informatics, this study examines whether corporate names with implications of luck and taboo have different effects on firm value using a sample of Chinese IPO firms. With the help of the green service system, it can provides investment decisions for the consumers. We find that after controlling for other influencing factors, P/E ratios are positively associated with lucky names but have a slightly negative relationship with taboo names. Similarly, CARs are positively correlated to lucky names but negatively with taboo names. The results also indicate that China’s IPO firms with taboo names have higher first-day returns, but drop faster than do other firms, indicating that these firms experience lower pricing when getting listed. Our findings highlight the economically meaningful role of firms’ names in the process of going public.
Enterprise Low-Carbon Behavior, Financial Performance and Economic Transformation——Data from Listed Companies in China
Authors: Sun Hongmei , Yao Shuqi , Zhai Mucun
Published: June 2021

The low-carbon development of enterprises is an important breakthrough in Chinese economic transformation and the optimization and upgrading of the industrial structure. Based on a sample of Chinese listed companies involved in the low-carbon industry from 2010 to 2018, this paper empirically analyzes the correlation between the low carbon behavior, economic transformation and financial performance of listed companies. The results show that a company’s carbon intensity and financial performance are negatively related, and this relation is more significant when the financial performance is measured using the ROA (return on asset) of listed companies. The level of economic transformation in places where enterprises are located can significantly strengthen the positive relationship between enterprise low-carbon behavior and financial performance, including in central and western areas, where positive relationships are strengthened, and areas with heavy polluting industries, where positive relationships are weakened. Therefore, it is necessary to strengthen carbon emission supervision for non-heavy polluting industries and enterprises in the central and western regions.
Research on the Path of Promoting the Development of Green finance in China Based on Internet Finance
Authors: Sun Yanping , Liu Yongzhi
Published: June 2021

As an important part of green finance, internet finance has certain advantages in promoting the development of green finance and is the main direction in promoting the development of green finance in China. The development of green finance can also create a better development environment for China’s internet finance. The 14th Five-Year Plan is the development period of China’s green finance, and “Internet + Green finance” will become a key breakthrough for China’s financial industry reform and development. On the basis of a clear understanding of its own advantages in developing green finance, China’s internet finance needs to understand the development requirements of green finance fully, strengthen its own strength, and explore the path of promoting the development of green finance actively from institutional cooperation, risk management, policy support, product innovation and other aspects.
Evaluation Index System for Green Development of Textile and Garment Industry
Authors: Niu Chengzhi , Zhu Yougan
Published: June 2021

This article uses the analytic hierarchy process to establish the textile industry green development evaluation index system. This index system supplements the existing textile industry green development evaluation system research to a certain extent, enriches the existing industry evaluation research, and further expands Vision and ideas for the development of the textile industry. This indicator system can help the textile and apparel industry to understand the transformation stage of the industry more reasonably in the green development, and help the textile and apparel industry to achieve a green and sustainable development transformation.
Research on rural landscape design of Yili River Basin under the background of low-carbon Economic Development——The example of Bayandai village
Authors: Wei Wei
Published: June 2021

With the deepening of One Belt, One Road Innitiative, Yili River Basin has also witnessed significant opportunities for rural tourism. Taking Bayandai village in Yili River Basin as an example, based on the local characteristic cultural resources, this paper discusses the rural landscape design methods with Yili characteristics, carries out systematic research of landscape culture, and displays the unique charm of rural tourism in Yili River basin with diversified landscape culture, so as to make it a banner of rural tourism in Yili River Basin, Boosting the reasonable development of low-carbon economy in border areas and promoting the level of tourism economy.
Vertical Integration of Agricultural products supply chain and quality Safety of Agricultural products
Authors: Li Yan , Zhang Cong Jing
Published: June 2021

Today, food safety is a common concern in the world. As the main source of food, agricultural products’ safety is also worthy of attention. By establishing the vertical integration model of the agricultural product supply chain, the circulation links of agricultural products can be reduced, and the circulation efficiency and quality level of agricultural products can be improved. This paper assumes that under the condition of simple fresh agricultural products, there is only one wholesaler and one retailer in the agricultural product supply chain. Through the analysis of the economic model, it is concluded that the vertical integration of the agricultural product supply chain has a positive impact on the safety of agricultural products. With the improvement of the vertical integration of the supply agricultural products supply chain, the efforts of wholesalers and suppliers to ensure the safety of agricultural products have been improved, the circulation cost of agricultural products has been reduced, and the sales price of agricultural products has been reduced.
Reverse Logistics Network Construction of Waste Electronic Products
Authors: Ning Zheng , Xin Gao
Published: June 2021

The acceleration of the updating and iteration of electronic products leads to the increasing types and quantity of waste electronic products, which poses a great threat to environmental protection and social development. The problem of reverse logistics of waste electronic products has gradually become the focus of social attention. This paper constructed the expected value model of the reverse logistics of waste electronic products based on the open loop supply chain, and made the implementation plan of the reverse logistics through the empirical analysis of the electronic and electrical appliances market in H city.
Executive Overconfidence and Green Innovation
Authors: Wang Dandan
Published: June 2021

As one of the important ways to achieve sustainable economic development, enterprise green innovation will also have an important impact on the future development of enterprises. Through the analysis, it is found that green innovation can realize the sustainable development of enterprises. However, green innovation has the characteristics of high risk and double externality, so the enthusiasm of enterprise green innovation is relatively low. As the decision maker of enterprises, the characteristics of management will have an important impact on green innovation. This paper studies the influence of Managerial Overconfidence on green innovation. This paper first studies the impact of management overconfidence on enterprise risk-taking ability, and finds that management overconfidence can improve enterprise risk-taking ability. Then it studies the impact of enterprise risk-taking ability on green innovation. The higher the enterprise risk-taking ability is, the more conducive to the implementation of green innovation activities. Through theoretical analysis, this paper concludes that management overconfidence can further promote the green innovation of enterprises by improving the risk-taking ability of enterprises.
Beauty of Energy-saving Makes You Impulsive! A Study on the Relationship between Product Aesthetics and Consumers’ Impulsive Purchase Intention
Authors: Yang Shansheng , Ji Meihui , Wang Jingyi
Published: June 2021

Appearance design greatly affects the influence of products on consumers, and product aesthetics plays an increasingly important role in consumers’ purchasing behavior. This article constructs a model of the influence of product aesthetics on consumers’ impulsive purchase intention, and puts forward corresponding hypotheses on this basis. Finally, the model and hypotheses are tested and revised through empirical methods. The data of this research shows that the aesthetic design level of products positively affects consumers’ impulsive purchase intentions, and positive emotions play an intermediary role between the two. At the same time, through analysis, this research confirms that consumers’ CVPA levels have an impact on products. Green stands for energy saving, and consumer behaviors that are conducive to reducing consumer spending and environmentally friendly can be favored. These can make consumers think of beautiful things, thereby enhancing impulsive consumption behavior. The relationship between aesthetics and consumers’ impulsive purchase intention has a moderating effect.
Analysis on the Influencing Factors of Green Technological Innovation Efficiency——Based on the Perspective of the Law Construction and Banking Efficiency
Authors: Zhang Yuxin , Sun Chenghao , Wang Shuoxin
Published: June 2021

Based on provincial data from 2010 to 2016, this paper uses regression model to analyze the factors affecting the green technology innovation efficiency and discuss the impact from the perspective of law construction and banking efficiency. The result shows that the law construction significantly improves the green technology innovation efficiency while the banking efficiency has the opposite result. Therefore, it is necessary to optimize financial structure and strengthen the legal protection of technological innovation, and ultimately promote high-quality development.
Maturity Evaluation of National Agro-technology Park Innovation Network Based on Improved Matter-element Extension Model From the Perspective of Intensive Development
Authors: Duan Huimin , Huo Ming , Zhang Xiaoyu , Zhang Liang
Published: June 2021

Based on the improved match-element extension model, the maturity of collaborative innovation network in China’s agricultural science and technology parks was explored with 257 national agricultural science and technology parks as research objects. The results show that: (1) the results obtained by measuring the maturity level of collaborative innovation network in national agricultural science and technology parks by asymmetric proximity degree are more consistent with the actual situation;(2) the maturity of collaborative innovation networks in national agricultural science and technology parks are good. Therefore, the park should replace the traditional resource input-driven development model through innovation-driven development to achieve low energy consumption, intensive and high-quality development.
Evaluation of the Teaching Quality and Ability of Hospital Administrators by Overseas Distinguished Teachers
Authors: Wu Zijian , Yu Shaoxuan , Li Yihua , Chen Shaohan , Wang Jia , Cheng Tiantian
Published: June 2021

In recent years, China has been actively promoting the Belt and Road Initiative. In the context of the gradual opening of the medical market, it is urgent to improve the health management knowledge and scientific research capabilities of the hospital administrators, further enhance the hospital management level, so that the hospitals can obtain a greater edge in the international medical competition. Using overseas intelligence to promote the internationalization of education is one of the important means. The Affiliated Cancer Hospital and Institute of Guangzhou Medical University has invited Portuguese management professors to establish an academic and educational cooperation relationship, and invited them to offer training for hospital administrators. This article uses questionnaires to survey the trainees participating in this training and evaluates the teaching quality of overseas teachers. The results showthat the interviewed students generally present high affirmation to the training effects of the training courses and the teaching quality of overseas distinguished teachers.
Personalized Reform of Computer Education Based on Network Teaching Mode
Authors: Hu Zhangrong , He Ke
Published: June 2021

The current education and teaching reforms are constantly creating a “student-centered, teacherled” teaching model, and promote the development of education and teaching in a personalized direction. Therefore, cultivating and improving the learning ability of college students through personalized network teaching mode has become one of the hot issues in the current education and teaching reform and development. The purpose of this paper is to study the personalized reform of computer education based on the network teaching model, based on the constructivist learning theory, combined with the research results of artificial intelligence, to the knowledge representation, student personality evaluation and teaching strategy decisionmaking in the personalized computer-assisted teaching system research and exploration have been carried out on other issues, forming a network teaching system with certain intelligence. In computer teaching, “Configuring Computer” is used as the learning theme to compare the advantages and disadvantages of personalized network teaching and traditional network teaching. A detailed analysis of the two inquiry learning and a more in-depth reflection were carried out. The experimental results show that the students’ inquiry cooperation ability and the quality of works in personalized online teaching have been improved to varying degrees. On the whole, the ratio of excellent to good in learning evaluation increased, and the ratio of medium to poor decreased, and the quality of multimedia works of more than 13% of students improved to excellent. The two teachings were carried out smoothly and basically achieved the expected goals proposed in this article.
Research on the construction mechanism of science and innovation corridor from the perspective of innovation chain
Authors: Li Jinghua , Han Ying , Liu Shulong
Published: June 2021

Based on the perspective of innovation chain, this paper takes Highway 128 and Guang-Shen Science and Technology Innovation Corridor as examples to explore the construction mechanism of science and technology innovation corridor. The findings are as follows: First, the corridor can be regarded as a virtual organization containing core nodes and auxiliary nodes. All nodes are not equal, and the core node plays the core function. Second, if the function of the core node is weakened, the science and innovation corridor will show a deterioration trend. Third, the construction of the science and innovation corridor is a process of the whole science and innovation chain from the flow and integration of knowledge resources, to the overflow of innovation incubation, and then to the market application. However, there are still problems in the chain, such as resource flow obstacles, innovation incubation breaks and structural imbalance. Therefore, in order to realize the benign interaction of multiple subjects in the science and innovation corridor, there needs to be a core subject that plays the role of agglomeration and diffusion, so as to realize the coordinated development of the corridor.
Research on the influence of entrepreneurship inheritance and innovation and entrepreneurship team growth on sustainable economic development from the perspective of psychological contract
Authors: Li Zhang , Sujuan Geng
Published: June 2021

The sustainable development of economy has always been the focus of society. Based on the data of some small and medium-sized enterprises in the new over the counter market from 2014 to 2018, this paper studies the relationship among entrepreneurship, psychological contract and the growth of innovation and entrepreneurship team. The empirical research shows that: the inheritance of entrepreneurship and the strengthening of psychological contract can promote the growth of innovation and entrepreneurship. When the psychological contract is strengthened, the entrepreneurship will also be inherited, and promoting the sustainable development of economy.
COVID-19’s influence on the credit risks and enterprise innovation of the Guangxi manufacturing——Based on the measure of KMV model
Authors: Shen LiJun , He Yu
Published: June 2021

The paper used the KMV model to manufacturing industry of Guangxi in China to concretely abstract the credit risk and enterprise innovation into a measurable quantitative index, and compare the changes in credit risk before and after COVID-19. This paper selects 17 Listed Companies in Guangxi manufacturing industry as empirical samples, and calculates the expected default rate of different companies by using the traditional and modified KMV models. The larger the index value is, the higher the credit risk is, And then affect the enterprise innovation activities. The results show that the overall credit risk management ability of Guangxi’s manufacturing industry is relatively high, but by the impact of COVID-19, credit risk has increased. If left unguarded, it will have an impact on enterprise innovation.
Study on risk assessment of prefabricated construction supply chain based on AHP
Authors: Li Keda , Zhu Weiwei
Published: June 2021

According to the national “14th Five-Year Plan”, the goal of supply chain is to upgrade the industrial supply chain. This paper conducts research on the supply chain risks of prefabricated buildings. By identifying the risks in the supply chain of prefabricated buildings, an index system of the supply chain of prefabricated buildings is constructed, and the risk assessment of the supply chain of prefabricated buildings is conducted through AHP. This paper proposes risk response strategies for external risks, planning, procurement, manufacturing, transportation, and delivery.
The Impact of Subclinical Hypothyroidism on Patients with Polycystic
Ovary Syndrome: A Meta-Analysis
Authors: Xing Yuling , Chen Jinhu , Liu Jing , Ma Huijuan
Published: June 2021

The association between subclinical hypothyroidism (SCH) and polycystic ovary
syndrome (PCOS) has been shown in many studies. These findings are still
controversial, however. It is unclear whether the co-incidence of subclinical
hypothyroidism and polycystic ovary syndrome will affect the severity of
metabolism. Therefore, we performed this meta-analysis to investigate the
association. A comprehensive search strategy was developed to obtain all
relevant studies published in PubMed, EMBASE, Cochrane Library, and Chinese
Academic Journal Full-text Database (CNKI) up to 31 December 2020. We adopted
the standardized mean difference (SMD) with 95% confidence intervals
(CI) for evaluation, and sensitivity analysis was performed. Publication bias
was analyzed and represented by a funnel plot, and funnel plot symmetry was
assessed with Egger’s test. Twenty-seven studies with 4821 participants
(1300 PCOS patients with SCH, 3521 PCOS patients without SCH) were included in
the present meta-analysis,among which 71.31% chinese patients out of the
total. The results showed that PCOS patients with SCH had higher levels of
HOMA-IR, TG, TC, LDL, FBG, FCP, PRL and lower levels of HDL, LH and T. It also
recognized the limitation of the lack of a consistent definition of
hypothyroidism in the 27 studies included. The results of this study indicated
that SCH may aggravate lipid and glucose metabolism in patients with PCOS.
Das Lymphsystem – Synthese von Erfahrungsheilkunde und Wissenschaft
Authors: Frost Jürgen , Tschech Bärbel
Published: June 2021

In allen traditionellen Heilsystemen finden sich Techniken, Heilpflanzen und Kräuterrezepturen, die das Lymphsystem beeinflussen – meist ohne diesen Zusammenhang konkret zu benennen. Auch schon unter den ältesten homöopathischen Komplexmitteln findet man Lymphmittel. Das zeigt die Bedeutung des Lymphsystems für die Therapie chronischer Erkrankungen in der Erfahrungsheilkunde. Inzwischen rückt das Lymphsystem auch in den Fokus der Wissenschaft – und erzwingt damit sogar ein Umdenken hinsichtlich des medizinischen Basiswissens.
Über das Lymphsystem
Authors: von Rosen Jürgen Freiherr
Published: June 2021

Obwohl die Lymphe und das ganze damit verbundene System rund 20 % des Körpergewichts ausmachen, findet es in der wissenschaftlichen medizinischen Literatur nur wenig Beachtung. Das Lymphsystem ist nur schwer zu untersuchen, da es u. a. keine Laboruntersuchungen dazu gibt. Seine Bedeutung ist jedoch bei vielen Erkrankungen nicht zu unterschätzen, worauf man in der klinischen Ausbildung nur selten hingewiesen wird. Der Beitrag schildert die Wirkungen des Lymphsystems und zeigt wichtige Therapiemöglichkeiten auf, die in der Klinik des Autors praktiziert und durch Fallbeispiele veranschaulicht werden.
Quality of reporting in endoscopic ultrasound: Results of an international multicenter survey (the QUOREUS study)
Authors: Fusaroli Pietro , Eloubeidi Mohamad , Calvanese Claudio , Dietrich Christoph , Jenssen Christian , Saftoiu Adrian , De Angelis Claudio , Varadarajulu Shyam , Napoleon Bertrand , Lisotti Andrea ,   the QUOREUS study group
Published: June 2021

Background and study aims The endoscopic report has a key role in quality improvement for gastrointestinal endoscopy. High quality standards have been set by the endoscopic societies in this field. Unlike other digestive endoscopy procedures, the quality of reporting in endoscopic ultrasound (EUS) has not been thoroughly evaluated and a reference standard is lacking.

Methods We performed an international online survey concerning the attitudes of endosonographers towards EUS reports in order to understand the needs for standardization and quality improvement. Endosonographers from different countries and institutional setting, with varying case volume and experience were invited to take part to complete a structured questionnaire.

Results We collected replies from 171 endosonographers. Overall analysis of results according to case volume, experience and working environment of respondents (academic, public hospital, private) are provided. In brief, everyone agreed on the need for standardization of EUS reporting. The use of minimal standard terminology and a structured tree with mandatory items was considered of primary importance. Image documentation was also deemed fundamental in complementing EUS reports both for patient documentation and research purposes. A strong demand for connection and consultation among endosonographers for clinical and training needs was also found. In this respect, a formal expert consultation network was advocated in order to improve the quality of reporting in EUS.

Conclusions Our survey showed a strong agreement among endosonographers who expressed the need for a standardization in order to improve the report and, as a consequence, the quality of EUS.
Calcitonin Stimulation Tests: Rationale, Technical Issues and Side Effects: A Review
Authors: Băetu Mara , Olariu Cristina Alexandra , Moldoveanu Gabriel , Corneci Cristina , Badiu Corin
Published: June 2021

Calcitonin (CT) stimulation tests have great value and could help to: differentiate thyroid causes of elevated CT apart from non-thyroid sources, determine whether the patients with slightly elevated basal CT could/could not be candidates for surgery, and indicate the right moment for prophylactic thyroidectomy in children with MEN syndromes when with normal basal CT. This triggered the requests for development of CT stimulation tests, taking into consideration their safety and aimed us to write a systematic review of literature regarding the rationale, technical issues, and side effects of CT stimulating tests used for diagnosis of MTC. After a thorough review of the literature, we classified the reported side effects by severity, as defined by United States Food and Drug Administration. A statistical analysis was performed using IBM SPSS Statistics version 20. Various side effects were noticed during stimulation tests that differ by intensity, duration and severity, depending on types of substances and protocols used. The side effects after pentagastrin test were significantly more severe than those reported after calcium stimulation test (p=0.0396). There are also significant gender-specific differences in side effects induced by stimulation tests. In conclusion, we recommend performing Ca CT stimulation test when needed, considering preventive evaluation of some clinical, instrumental, and biochemical aspects of each patient. Precise instructions should be followed before a stimulation test and furthermore continuous cardiac monitoring is essential during and after the test to minimize the possibility of a serious event.
Laparoskopische Heller-Myotomie zur Therapie der Achalasie
Authors: Rolinger Jens , Miller Johanna , Bolzenius Rupert , Granderath Frank , Kirschniak Andreas , Wilhelm Peter
Published: June 2021

Zielsetzung In der Literatur bezeichnet die Achalasie eine primär ösophageale Motilitätsstörung, die durch das Fehlen von Peristaltik und durch inkomplette oder vollständig fehlende Relaxation des unteren Ösophagussphinkters charakterisiert ist. Leitsymptom ist die Dysphagie. Das Therapieziel besteht in der chirurgischen oder interventionellen Behebung der ösophagealen Ausflussbahn auf Höhe der ösophagogastralen Übergangszone.

Indikation Wir präsentieren den Fall eines 24-jährigen Patienten, der sich mit einer seit 2 Jahren bestehenden Dysphagie, begleitet von Regurgitationen, Odynophagie sowie einem unbeabsichtigten Gewichtsverlust, vorstellt.

Methoden Das Video erläutert die präoperativen bildgebenden sowie endoskopischen Befunde und zeigt die Technik der laparoskopischen Heller-Myotomie mit partieller Fundoplicatio nach Dor.

Schlussfolgerung Hinsichtlich der Therapie der klassischen Achalasie kann die laparoskopische Heller-Myotomie mit partieller Fundoplicatio nach Dor – trotz Kontroversen hinsichtlich der peroralen endoskopischen Myotomie als alternative Therapieoption – als etabliertes Standardverfahren angesehen werden.
Parametric resonance magnetometer based on elliptically polarized light yielding three-axis measurement with isotropic sensitivity
Authors: Le Gal Gwenael , Rouve Laure-Line , Palacios-Laloy Agustin
Published: June 2021

We present here a parametric resonance magnetometer scheme based on elliptically polarized pumping light and two radio frequency fields applied along the two optical pumping directions. At optimum ellipticity and radio frequency fields' amplitudes, the three components of the magnetic field are measured with an isotropic sensitivity. Compared to the usual alignment-based parametric resonance magnetometers, the sensitivity is degraded by a factor of 2 for two components of the magnetic field but improved by a factor of 9 for the third one. The open-loop bandwidth was measured to be greater than 1 kHz for the three axes. This magnetometer configuration could be particularly interesting for geophysics and biomedical imaging.
Proton acceleration from thin foils by extremely short PW laser pulse
Authors: Brantov A. V. , Bychenkov V. Yu.
Published: June 2021

In the context of current efforts to compress PW-level laser pulses to an order of 10 fs, the 3D optimization particle-in-cell (PIC) simulations of proton acceleration have been performed to maximize the proton energy cutoffs using CH2 foils as an example. This was complemented by a simple theoretical model to which PIC simulation results were qualitatively compared. Such a model accounted for a fast increase in a backside surface hot spot, transition of plasma expansion from isothermal regime to the adiabatic one, and effect of target semitransparency that is important for the considered extremely short pulses. It was found that the twofold increase in a shortened laser pulse focal spot size is fraught with a loss in the maximum energy of accelerated protons even when the pulse energy is the same. The PIC simulation optimization study revealed the optimal target thicknesses and the corresponding maximum energies of accelerated protons for shortened PW pulses, and also showed that advantage from their use to increase the proton energy occurs only if the focusability at the target is not worsened.
Deterministic scattering of relativistic electron beams by off-resonant circularly polarized electromagnetic waves
Authors: Yoon Young Dae , Ji Jeong-Young , Yun Gunsu S.
Published: June 2021

A mechanism is presented whereby relativistic electron beams localized in phase space are deterministically scattered by coherent circularly polarized electromagnetic waves without stochastic processes. It is shown via an exact single-particle analysis that the condition for maximal scattering is an off-resonant condition, contrary to previous kinetic analyses that predict maximal diffusion or interaction at exact resonance or its harmonics. The mechanism, verified by single-particle simulations, enables a fast, nonlinear redistribution of the beam particles. A possible application of this mechanism to runaway electron suppression is presented.
Performance enhancement of a self-powered solar-blind UV photodetector based on ZnGa2O4/Si heterojunction via interface pyroelectric effect
Authors: Han Dongyang , Liu Kewei , Chen Xing , Li Binghui , Zhai Tianyou , Liu Lei , Shen Dezhen
Published: June 2021

The photodetectors based on the wide bandgap semiconductor (WBS)/Si heterojunction have attracted more and more attention in recent years due to their excellent photoelectric characteristics and easy integration capabilities. In this work, we have demonstrated a self-powered solar-blind ultraviolet (UV) photodetector based on the ZnGa2O4/Si heterojunction. A typical rectification characteristic with a rectification ratio exceeding 103 within ±5 V can be obtained. At 0 V bias, the −3 dB cutoff wavelength of ∼255 nm and the UV-visible rejection ratio of ∼3 × 102 show that the device has excellent self-powered solar-blind UV detection performance. In addition, the responsivity and the response speed of ZnGa2O4/Si heterojunction can be efficiently enhanced by a transient spike current at 0 V bias when turning on and off the 254 nm UV light. The interface pyroelectric effect of the ZnGa2O4 film should be responsible for this transient spike photocurrent phenomenon. Our findings in this work pave a feasible way to realize high-performance WBS/Si heterojunction self-powered solar-blind photodetectors.
Tunable self-trapped excitons in 2D layered rubrene
Authors: Feng Shaopeng , Yang Yutian , Gao Lei , Watanabe Kenji , Taniguchi Takashi , Hu Zhenliang , Lu Junpeng , Ni Zhenhua
Published: June 2021

As emerging efficient emitters, two-dimensional (2D) organic semiconductors offer an intriguing potential to the low-cost and high-performance light emitting devices. However, organic semiconductors usually suffer from serious luminescence quenching owing to the self-trapped exciton formation which prevalently occur in materials with soft lattice and strong exciton-phonon coupling. Therefore, revealing the underlying mechanism that leads to self-trapped excitons is a prerequisite for increasing the photoluminescence (PL) efficiency in organic materials. Here, we grew high-quality layered rubrene films on hexagonal boron nitride through a physical vapor transport method. Combined with time-resolved photoluminescence (TRPL) spectra and laser power dependent TRPL spectra, we confirmed the free exciton (FE) and self-trapped exciton (STE) emission. We found that STEs evolved from FEs from the temperature dependent PL characterization. In addition, we observed tunable STEs in a 2D layered rubrene: reducing the layer number could strongly suppress the exciton transferring efficiency and the rate from a free exciton state to a self-trapped exciton state which result from the decreased self-trapping depth and increased barrier height. Consequently, the average PL intensity is strongly enhanced about seven times, whereas STE emission is quenched. The results provide a method for suppressing the STE formation process and contribute to improving the photoluminescence efficiency in optoelectronic applications.
Formation free energy of an i-mer at spinodal
Authors: Nie Chu , Geng Jun , Marlow William. H.
Published: June 2021

In statistical mechanics, the formation free energy of an i-mer can be understood as the Gibbs free energy change in a system consisting of pure monomers after and prior to the formation of the i-mer. For molecules interacting via Lennard-Jones potential, we have computed the formation free energy of a Stillinger i-mer [F. H. Stillinger, J. Chem. Phys. 38, 1486 (1963)] and a ten Wolde–Frenkel (tWF) [P. R. ten Wolde and D. Frenkel, J. Chem. Phys. 109, 9901 (1998)] i-mer at spinodal at reduced temperatures from 0.7 to 1.2. It turns out that the size of a critical Stillinger i-mer remains finite and its formation free energy is on the order of kBT, and the size of a critical tWF i-mer remains finite and its formation free energy is even higher. This can be explained by Binder’s theory [K. Binder, Phys. Rev. A 29, 341 (1984)] that for a system, when approaching spinodal, if the Ginzburg criterion is not satisfied, a gradual transition will take place from nucleation to spinodal decomposition, where the free-energy barrier height is on the order of kBT.
Enhanced thermoelectric performance of pentacene via surface charge transfer doping in a sandwich structure
Authors: Zhao Wenrui , Dai Xiaojuan , Liu Liyao , Meng Qing , Zou Ye , Di Chong-an , Zhu Daoben
Published: June 2021

We demonstrate an enhanced electrical conductivity and power factor for pentacene based small-molecule organic thermoelectric (OTE) materials by constructing a PbI2/pentacene/PbI2 sandwich structure where the PbI2 serves as the surface transfer p-type dopant. The electronic structure evolution at interfaces between pentacene and PbI2 are investigated via in situ ultraviolet and x-ray photoelectron spectroscopy analysis. Significant charge transfer between pentacene and PbI2 is observed due to a high work function of PbI2 and a low ionization potential of pentacene. Such an interfacial charge transfer behavior results in efficient hole doping of pentacene from both sides. The increased hole density inside pentacene leads to the improvement in the thermoelectric performance, achieving a maximum power factor of 33.75 μW m−1 K−2 with an optimized pentacene interlayer thickness. This study opens a way to improve the OTE materials with the dopant/organic semiconductor/dopant sandwich structure.
Solute dispersion in transient Casson fluid flow through stenotic tube with exchange between phases
Authors: Das Prosanjit , Sarifuddin  , Rana Jyotirmoy , Mandal Prashanta Kumar
Published: June 2021

A mathematical study on solute dispersion has been carried out in a stenotic tube having an absorptive wall—a study relevant to arterial pharmacokinetics. The rheology of blood is represented by Casson model and the solute is introduced at a point that is uniformly distributed over the cross section. The two-dimensional fluid flow is considered in this study. The governing equations of motion for the flow of Casson fluid, for the transport of solute in the lumen as well as in the tissue along with appropriate initial and boundary conditions, are numerically solved by leveraging the Marker and Cell method and the immersed boundary method in staggered grids formulation. Following the introduction of solute, we provide a comprehensive investigation of the influence of the wall absorption parameter (κ), yield stress (τy), and the severity of the stenosis (ξ) on the three transport coefficients, namely, the fraction of solute remaining in the fluid phase, the apparent convection velocity, and the dispersion coefficient. Simulated results predict the diminishing magnitudes of the transport coefficients with the increase in the values of yield stress and absorption parameter. Moreover, the transport coefficients and the axial mean concentration get significantly perturbed by the severity of the stenosis. Obtained results presented graphically concur with existing steady-state results in the literature. The present study would certainly be of some use in the case of targeted drug delivery and in treatment related to microvascular disease.
Effect of isothermal crystallization in antiferromagnetic IrMn on the formation of spontaneous exchange bias
Authors: Liu Bo , Wang Baomin , Nie Tongxin , Xie Yali , Yang Huali , Li Gengfei , Pan Jianguo , Li Run-Wei
Published: June 2021

Recently, a spontaneous exchange bias (SEB) driven by the isothermal crystallization of the antiferromagnetic IrMn layer has been reported in IrMn/FeCo bilayer. However, the key factors to determine the magnitude of SEB have not been clearly understood yet. Here, we investigate the effect of isothermal crystallization in IrMn layer on the formation of SEB in IrMn/CoFeB bilayer through preparing the samples with different degrees of isothermal crystallization in IrMn layer. The SEB is negligible in the sample with more structure-stable IrMn layer, confirming that the isothermal crystallization of IrMn plays a crucial role in the formation of SEB. However, the SEB field does not change significantly with the free-relaxation time of IrMn/CoFeB bilayers or IrMn layer. These results indicate that a slight degree of isothermal crystallization in IrMn layer is sufficient to induce a large SEB in IrMn/CoFeB bilayer. Our results not only confirm the newly reported SEB driven by the isothermal crystallization in IrMn layer but also clarify the key factor to control the magnitude of SEB.
Modulation of resistive switching properties of non-stoichiometric WO3−x based asymmetric MIM structure by interface barrier modification
Authors: Rudrapal Krishna , Mukherjee A. , Adyam V. , Roy Chaudhuri Ayan
Published: June 2021

The impact of device operation condition and ambient moisture on the interface-type resistive switching (RS) characteristics of a non-stoichiometric polycrystalline tungsten oxide (WO3−x) based metal–insulator–metal device with an Au top electrode and a Pt bottom electrode has been investigated. The device exhibits rectification and stable bipolar RS characteristics without the need for any forming step, where the switching is primarily dominated by the Schottky type Au/WO3−x interface. DC conduction characteristics of the device have been investigated at different temperature, bias stress, and relative humidity conditions. Current conduction through the active layer has been found to be dominated by Schottky emission at low electric field and Poole–Frenkel emission at high electric field. An increase in current and a strong reduction in the rectification characteristic have been observed on subjecting the device to DC bias stress of appropriate polarity as well as increasing ambient moisture. Modification of the Schottky barrier due to defect redistribution when DC bias stress is applied and due to the dipoles induced at the Au/WO3−x interface by water molecules with increasing ambient moisture content have been discussed as a possible mechanism of the observed RS modulation.
Electroresistance in metal/ferroelectric/semiconductor tunnel junctions based on a Hf0.5Zr0.5O2 barrier
Authors: Jiao Peijie , Xi Zhongnan , Zhang Xiaoyu , Han Yajie , Wu Yang , Wu Di
Published: June 2021

Ferroelectric Hf0.5Zr0.5O2 films, 5.8 nm in thickness, were deposited on Nb:SrTiO3 semiconductor substrates to form a Pt/Hf0.5Zr0.5O2/Nb:SrTiO3 metal/ferroelectric/semiconductor ferroelectric tunnel junction (FTJ). A high tunneling electroresistance ratio of 800 was achieved at room-temperature. It is observed that in the low resistance state, the transport characteristic obeys direct tunneling, while in the high resistance state, it is dominated by thermal emission. It implies that the Schottky barrier on the surface of the semiconductive electrode is modulated by the polarization in the ferroelectric Hf0.5Zr0.5O2 barrier, generating the high electroresistance ratio. The FTJ also exhibits excellent retention for more than 10 000 s and good switching endurance for more than 1500 cycles. The results suggest the potential of this HfO2-based FTJ for next generation nonvolatile memories.
Decoupling bulk and surface recombination properties in silicon by depth-dependent carrier lifetime measurements
Authors: Yokoyama K. , Lord J. S. , Miao J. , Murahari P. , Drew A. J.
Published: June 2021

Muons, as a bulk probe of materials, have been used to study the depth profile of charge carrier kinetics in Si wafers by scanning the muon implantation depth. The photoexcited muon spin spectroscopy technique can optically generate excess carriers in semiconductor wafers, while muons can measure the excess carrier density. As a result, carrier recombination lifetime spectra can be obtained. The depth-dependent lifetime spectra enable us to accurately measure the bulk carrier lifetime and surface recombination velocity by fitting the spectra to a simple one-dimensional diffusion model. Unlike other traditional lifetime spectroscopy techniques, the bulk and surface recombination properties can be readily de-convoluted in this method. Here, we have applied the technique to study silicon wafers both with and without passivation treatment and have demonstrated that the model can correctly describe the carrier kinetics in these two cases.
The study on flow properties of nonconvex particles down a rough inclined plane
Authors: Han Wenjin , Wang Dengming , Wu Yisong
Published: June 2021

This study numerically examines the flow of nonspherical particles down a rough inclined plane based on the discrete element method. We use triangular, nonconvex particles to systematically explore the effect of their nonconvexity on the flow properties while weakening the impact of their orientation such that the degree of nonconvexity can be accurately varied. We first present a phase diagram of flow states in the parameter space of the angle of inclination and particle nonconvexity. The flow properties of nonconvex particles, especially the profiles of several characteristic quantities along the vertical direction of flow, are then examined in the steady flow regime. Finally, rheological models of the steady flow of nonconvex particles down a rough inclined plane are formulated based on the well-established laws of friction and dilatancy for spheres/disks, and particle nonconvexity is introduced to them as an independent parameter based on two rescaling functions. This proposed method to construct rheological models of nonspherical particles is expected to be applicable to dense flows of particles with more complex shapes and flow conditions.