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1.
J Prosthet Dent ; 2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37160412

RESUMO

Guiding planes are essential to the success of removable partial dentures (RPDs). With computer-aided design and computer-aided manufacturing (CAD-CAM), this report presents a novel method of designing and fabricating preparation templates to precisely prepare guiding planes for RPD abutments.

2.
Chemistry ; 28(68): e202202358, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36048512

RESUMO

Surface oxygen functionalities (particularly C-O configuration) in carbon materials have negative influence on their electrical conductivity and Na+ storage performance. Herein, we propose a concept from surface chemistry to regulate the oxygen configuration in hierarchically porous carbon nanosheets (HPCNS). It is demonstrated that the C-O/C=O ratio in HPCNS reduces from 1.49 to 0.43 and its graphitization degree increases by increasing the carbonization temperature under a reduction atmosphere. Remarkably, such high graphitization degree and low C-O content of the HPCNS-800 are favorable for promoting its electron/ion transfer kinetics, thus endowing it with high-rate (323.6 mAh g-1 at 0.05 A g-1 and 138.5 mAh g-1 at 20.0 A g-1 ) and durable (96 % capacity retention over 5700 cycles at 10.0 A g-1 ) Na+ storage performance. This work permits the optimization of heteroatom configurations in carbon for superior Na+ storage.

3.
Chem Asian J ; 18(16): e202300449, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37382427

RESUMO

Hard carbon, as the most promising commercial anode materials of sodium-ion batteries (SIBs), has suffered from the coupling limitations on initial Coulombic efficiency (ICE), capacity, and rate capability. Herein, to break such coupling limitations, sulfur-rich nitrogen-doped carbon nanomaterials (S-NC) were synthesized by a synergistic modification strategy, including structure/morphology regulation and dual heteroatom doping. The small specific surface area of S-NC is beneficial for inhibiting excessive growth of solid electrolyte interphase (SEI) film and irreversible interfacial reaction. The covalent S can serve as active electrochemical sites by Faradaic reactions and provide extra capacity. Benefit by N, S co-doping, S-NC shows large interlayer spacing, high defects, good electronic conductivity, strong ion adsorption performance, and fast Na+ ion transport, which combined with a more significant pore volume result in speedier reaction kinetics. Hence, S-NC possesses a high reversible specific capacity of 464.7 mAh g-1 at 0.1 A g-1 with a high ICE of 50.7%, excellent rate capability (209.8 mAh g-1 at 10.0 A g-1 ), and superb long-cycle capability delivering a capacity of 229.0 mAh g-1 (85% retention) after 1800 cycles at 5.0 A g-1 .

4.
Chem Commun (Camb) ; 57(75): 9610-9613, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34546262

RESUMO

In situ Raman and electrochemical results reveal that Na+ adsorbs on the surface/defective sites of N/P-HCNF and inserts randomly into its turbostratic nanodomains in the dilute state without a staged formation, which can facilitate fast Na+ diffusion kinetics for efficient sodium storage.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31653106

RESUMO

The elderly are susceptible to depression, especially empty nesters. This study investigated the risk factors associated with depression in empty nesters. The participants were selected via multi-stage random cluster sampling. Depression symptoms were assessed using the Geriatric Depression Scale. The questionnaire surveyed demographic characteristics, underlying diseases, behaviors and lifestyles, negative life experiences, social support, self-care ability, etc. Chronic health conditions, such as being overweight/obese, smoking cessation, cancer, and chronic pain, as well as negative life experiences, such as the death of a loved one and financial loss, increased the risk of depression in empty nesters. In addition, the incapability of performing self-care also increased the risk of depression in empty nesters. The prevalence of depression in empty nesters was high. Being overweight/obese, cancer, chronic pain, smoking cessation, the death of a loved one, financial loss, and the incapability to deliver self-care were risk factors for depression in empty nesters. It is recommended that comprehensive measures be taken to enhance health interventions for this population, including encouraging a proper diet and physical activity for weight control, providing psychological counseling after negative life experiences, and teaching correct methods of smoking cessation.


Assuntos
Transtorno Depressivo/epidemiologia , Apego ao Objeto , Relações Pais-Filho , Pais/psicologia , Qualidade de Vida/psicologia , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Inquéritos e Questionários
6.
J Hazard Mater ; 138(1): 169-72, 2006 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-16839672

RESUMO

Terephthalic acid, which is a main component in alkali-decrement wastewater, is efficiently removed using ferric chloride in high pH solutions. About 90% removal of terephthalic acid is achieved at pH between 8 and 11. Especially, the removal reached 94.3% at pH 11. However, as the pH increased from pH 12 and 13, the low removal of terephthalic acid were found. The increasing ferric chloride dosage had a dramatic positive impact on the achieved removal of terephthalic acid. Further increase in the ferric chloride dosage did not produce better removal rate. The increase of terephthalic acid concentration also led to the increase of ferric chloride dosage in order to get the same removal of terephthalic acid. There was approximately a negative linear relationship between terephthalic acid concentration and removal of terephthalic acid. Compared with other coagulants, it can be seen that ferric chloride is more effective in a high pH solution and the amount of ferric chloride required is also less as compared with aluminum chloride, magnesium chloride and calcium chloride. Our results clearly showed that terephthalate anions strongly binds to positive Fe(OH)(3) flocs and forms insoluble complexes, probably through a mechanism involving electrostatic attraction. The electrostatic attraction may be particularly useful means of purifying wastewater in high pH solutions.


Assuntos
Compostos Férricos/química , Ácidos Ftálicos/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Cloreto de Alumínio , Compostos de Alumínio/química , Cloreto de Cálcio/química , Cloretos/química , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Cloreto de Magnésio/química , Eletricidade Estática
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