Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Assunto principal
Intervalo de ano de publicação
1.
PLoS One ; 17(7): e0269089, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35793371

RESUMO

As a result of business environment reforms in China's Hangzou, the cost of business has reduced, the confidence of Hangzhou enterprises has survived the COVID-19 outbreak, and foreign investment continues to increase. Nevertheless, Hangzhou's business environment has shortcomings, such as insufficient technology, talent, and intelligent infrastructure. Two unresolved questions persist: (i) Has the smart business environment stimulated corporate investment by reducing system costs and boosting corporate confidence? (ii) How do the commercial climate's shortcomings impact the relationship between the intelligent business environment and business costs/confidence? We examined the impact of a local smart business environment on the corporate investment scale in Hangzhou using factor analysis, cluster analysis, linear regression, and path analyses of data from 297 firm managers. Smart governance improved public administration, financing, and rule of law. The business environment promoted investment by increasing business confidence and decreasing institutional costs. Weak intelligent property protection and legal fairness hindered the positive influence of smart governance on business confidence and system costs. This is the first study combining business environment, smart city, and smart governance concepts to analyze the influence of local smart business environments on business confidence, institutional costs, and investment. Our conclusion on the limitation effect of intelligent business environment on enterprise investment attempts to inspire further research on the intersection of business environments and smart cities. The law of intelligent business environment attracting investment obtained in the context of China, the largest developing country with diversified economic development, is of great significance for other developing countries. Countries can attract investment and promote economic development through intelligent governance. Developing countries should construct smart service platforms, coordinate supervision of public credit, reduce financing constraint, construct a government under the rule of law, improve the quality of land management, and protect intellectual property rights.


Assuntos
COVID-19 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Comércio , Desenvolvimento Econômico , Humanos , Investimentos em Saúde , Organizações
2.
Adv Sci (Weinh) ; 9(17): e2105773, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35398997

RESUMO

Polymer dielectric capacitors are widely utilized in pulse power devices owing to their high power density. Because of the low dielectric constants of pure polymers, inorganic fillers are needed to improve their properties. The size and dielectric properties of fillers will affect the dielectric breakdown of polymer-based composites. However, the effect of fillers on breakdown strength cannot be completely obtained through experiments alone. In this paper, three of the most important variables affecting the breakdown strength of polymer-based composites are considered: the filler dielectric constants, filler sizes, and filler contents. High-throughput stochastic breakdown simulation is performed on 504 groups of data, and the simulation results are used as the machine learning database to obtain the breakdown strength prediction of polymer-based composites. Combined with the classical dielectric prediction formula, the energy storage density prediction of polymer-based composites is obtained. The accuracy of the prediction is verified by the directional experiments, including dielectric constant and breakdown strength. This work provides insight into the design and fabrication of polymer-based composites with high energy density for capacitive energy storage applications.

3.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(12): 3330-3, 2015 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-26964204

RESUMO

The measurement speed is an important parameter of terahertz time-domain spectroscopy (THz-TDS) instruments. To improve the measurement speed of the spectrometer we need to increase the scanning speed of the delay line. In this paper, we study the influence of the scanning speed, the time constant of lock-in amplifier and the sampling rate on the signal quality. The results show that, when the time constant equal to 10 ms, increasing the scanning speed does not cause significant changes in the amplitude of the signal. But when the time constant equal to 30, 100 and 300 ms, with the increasing of the scanning speed the signal amplitude decreases rapidly. Therefore, the time constant should be set as small as possible to avoid deterioration of signal quality. On the other hand, higher the scanning speed is, fewer data points are collected with a same time-domain length. Therefore, when the scanning speed increase, not only the time constant should be reduced, but also the sampling rate should be increased to avoid the distortion of signal waveform caused by the number reduction of data points. The conclusions can provide a reference for improving the measurement speed of THz-TDS instrument.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...