Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nanotechnology ; 31(27): 274003, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32209740

RESUMO

This work presents a study on the controlled growth of WO3 nanowires via chemical vapor deposition without catalyst, and their potential applications in visible photodetectors. The influence of growth conditions on the morphology of WO3 nanowires is studied in order to understand the growth mechanism of WO3 nanowires, and ultra-long (60 [Formula: see text], the longest one ever reported) WO3 nanowires with a spindle shape are achieved by optimizing the growth conditions. It was found that the length of WO3 nanowires increases from 15 [Formula: see text] to 60 [Formula: see text] with increasing the argon carrier gas flow rate from 30 sccm to 90 sccm, and then saturates with further increasing the argon carrier gas flow rate. However, the length of WO3 nanowires reduces from 60 [Formula: see text] to 19 [Formula: see text] with increasing the tube inner pressure from 2.5 Torr to 3.5 Torr. The photoconductor detectors based on WO3 single nanowires present excellent device performance with a responsivity as high as 19 A W-1 at a bias of 0.1 V, a detectivity as high as 1.06 × 1011 Jones, and a response (rising and decay) time as short as 8 ms under the illumination of a 404 nm laser. These results indicate the great potential of WO3 nanowires for applications in fabricating high performance visible photodetectors.

2.
Zhonghua Er Ke Za Zhi ; 57(11): 876-881, 2019 Nov 02.
Artigo em Chinês | MEDLINE | ID: mdl-31665843

RESUMO

Objective: To investigate the knowledge regarding clinical research among children at 8-18 years of age. The survey results will form the basis for developing public education program for this population. Methods: The survey was conducted among children at 8-18 years of age using WeChat and spot investigation between January 2016 and January 2017. According to different developmental stages, the survey population was divided into four groups: age 8-10, 11-13, 14-15 and 16-18 years. The level of knowledge regarding clinical research was analyzed. Results: Totally 1 329 questionnaires were issued and 1 233 effective questionnaires were returned with a recovery rate of 92.8%. The overall awareness rate regarding clinical research was 32.8% (405/1 233) . It revealed that 282 (22.9%) individuals thought that clinical research was to treat people like experimental rats. When asked "who have the final decision on research participation", the percentages of those who chose oneself, parents or guardian and doctor were 44.6% (550/1 233), 74.2% (915/1 233) and 36.8% (454/1 233) respectively. When asked "If you want to participate a study, but your parents or guardian do not agree, what would you do?", 33.9% (418/1 233) of individuals will "give up". As to "If you do not want to participate a study, but your parents or guardian think you should, what would you do?", 51.3% (632/1 233) chose "listen to parents" and 28.8% (355/1 233) chose "refuse the suggestions of parents or guardian". As to "what are your greatest concerns of participating an investigation?" , 68.1% (840/1 233) chose "worry about added pain or discomfort". but 58.0% (715/1 233) thought if "doctors and nurses take good care of me" their "concerns will reduce" or "feel better to participate in the research?". 55.6% (686/1 233) and 49.3% (608/1 233) individuals responded that they will "participate in an research?" when they "know that other people also participate the research" and when they "know the details regarding what will happen after the enrollment". Conclusions: The knowledge level of clinical research among children aged 8-18 years were not high. It is very necessary to promote the public education of clinical research for this population and also very necessary to address their concern regarding the research.


Assuntos
Ensaios Clínicos como Assunto , Conhecimentos, Atitudes e Prática em Saúde , Adolescente , Ansiedade , Criança , Feminino , Humanos , Masculino , Inquéritos e Questionários
3.
Trop Biomed ; 31(2): 261-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25134894

RESUMO

The objective of the present survey was to reveal the prevalence of helminths in adult goats in Hunan Province, the People's Republic of China. From July 2010 through February 2013, a total of 479 goats slaughtered in local abattoirs and markets were examined for the presence of helminths using a helminthological approach. Eighty-six percent of the examined goats were infected with at least one species of helminths. In total, 15 genera of helminths were found representing 2 phyla, 3 classes, 5 orders, and 11 families. Oesophago-stomum, Ostertagia and Haemonchus were the most prevailing nematode genera, Eurytrema was the predominant trematode genus detected, whereas the infection of adult goats with cestodes was not common, with Cysticercus tenuicollis being the most common genus. The worm burdens showed obvious seasonal variation in that nematodes and cestodes were abundant in summer and winter, and the trematodes peaked in winter, which was consistent with the seasonal precipitation of Hunan Province. The geographical distribution of helminths in goats ascended with altitude. Goats in the mountainous areas were more severely infected with helminths than goats in the hilly areas, whereas infection of goats with helminths was much less in the lake areas. The present investigation highlights the high prevalence of helminths in adult goats in Hunan Province, China, which provides baseline data for assessing the effectiveness of future prevention and controlling measures against helminth infection in adult goats in this province and elsewhere.


Assuntos
Doenças das Cabras/epidemiologia , Doenças das Cabras/parasitologia , Helmintíase/parasitologia , Helmintos/classificação , Helmintos/isolamento & purificação , Animais , China/epidemiologia , Geografia , Cabras , Carga Parasitária , Prevalência , Estações do Ano
4.
Sci Rep ; 4: 5449, 2014 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-24965260

RESUMO

InPBi was predicted to be the most robust infrared optoelectronic material but also the most difficult to synthesize within In-VBi (V = P, As and Sb) 25 years ago. We report the first successful growth of InPBi single crystals with Bi concentration far beyond the doping level by gas source molecular beam epitaxy. The InPBi thin films reveal excellent surface, structural and optical qualities making it a promising new III-V compound family member for heterostructures. The Bi concentration is found to be 2.4 ± 0.4% with 94 ± 5% Bi atoms at substitutional sites. Optical absorption indicates a band gap of 1.23 eV at room temperature while photoluminescence shows unexpectedly strong and broad light emission at 1.4-2.7 µm which can't be explained by the existing theory.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA