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1.
Adv Sci (Weinh) ; 11(6): e2306740, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38054649

RESUMO

Ion doping is an effective strategy for achieving high-performance flexible Cu2 ZnSn(S,Se)4 (CZTSSe) solar cells by defect regulations. Here, a Li&Na co-doped strategy is applied to synergistically regulate defects in CZTSSe bulks. The quality absorbers with the uniformly distributed Li and Na elements are obtained using the solution method, where the acetates (LiAc and NaAc) are as additives. The concentration of the harmful CuZn anti-site defects is decreased by 8.13% after Li incorporation, and that of the benign NaZn defects is increased by 36.91% after Na incorporation. Synergistic Li&Na co-doping enhances the carrier concentration and reduces the interfacial defects concentration by one order of magnitude. As a result, the flexible CZTSSe solar cell achieves a power conversion efficiency (PCE) of 10.53% with certified 10.12%. Because of the high PCE and the homogeneous property, the Li&Na co-doped device is fabricated to a large area (2.38 cm2 ) and obtains 9.41% PCE. The co-doping investigation to synergistically regulate defects provides a new perspective for efficient flexible CZTSSe solar cells.

2.
Opt Lett ; 48(20): 5265-5268, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37831843

RESUMO

Antimony sulfide (Sb2S3) photodetectors (PDs) have great potential in commercial applications. The performances are affected by photocarrier distribution and recombination. Here, the gate-controlled Sb2S3 thin film PD is fabricated on the TiO2/SiO2/Si substrate by the vacuum method. The p-channel Sb2S3 transistor obtained a threshold voltage of 0.6 V and a switching ratio of 1064, achieving an effective regulation by gate voltages. A negative gate voltage can enhance conductivity and can suppress recombination. The responsivity and detectivity of the PD reach 1.6 A/W and 1.2 × 1011 Jones, respectively. The device realizes logic outputs by the signal inputs of illumination and gate voltage.

3.
Psychiatry Res ; 326: 115329, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37437488

RESUMO

BACKGROUND: Over the past several decades the prevalence of adolescent non-suicidal self-injury (NSSI) has been rising steadily. Understanding the factors associated with NSSI is a critical public health concern. The current study aims to explore the critical factors related to NSSI among Chinese adolescents. METHODS: A systematic literature search was conducted to identify the studies meeting our eligibility criteria (published until June 2022) in PubMed, Web of Science, Science Direct, Springer Link, CNKI, VIP, and Wanfang data. The meta-package of R language was used to perform a meta-analysis to compute the pooled effect (r). RESULTS: A total of 59 studies were included in this analysis, with a sample size of 192,546. Twenty-four democratic, personal, and social factors were examined in current study. The pooled effect value (r) has revealed that 23 factors are associated with NSSI behaviors among Chinese adolescents. The factor, Internet addiction, has demonstrated the greatest association with NSSI compared to other factors. CONCLUSION: Consistent with previous studies on adolescent NSSI, findings have demonstrated that a number of demographic, personal, and social factors significantly contribute to NSSI behaviors among Chinese adolescents. Future research on prevention and intervention for adolescent NSSI may benefit from targeting these factors.

4.
ACS Nano ; 17(17): 16633-16643, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37458508

RESUMO

Bismuth oxyselenide (Bi2O2Se) is a two-dimensional (2D) layered semiconductor material with high electron Hall mobility and excellent environmental stability as well as strong spin-orbit interaction (SOI), which has attracted intense attention for application in spintronic and spin optoelectronic devices. However, a comprehensive study of spin photocurrent and its microscopic origin in Bi2O2Se is still missing. Here, the helicity-dependent photocurrent (HDPC) was investigated in Bi2O2Se nanosheets. By analyzing the dependence of HDPC on the angle of incidence, we find that the HDPC originates from surface states with Cs symmetry in Bi2O2Se, which can be attributed to the circular photogalvanic effect (CPGE) and circular photon drag effect (CPDE). It is revealed that the HDPC current almost changes linearly with the source-drain voltage. Furthermore, we demonstrate effective tuning of HDPC in Bi2O2Se by ionic liquid gating, indicating that the spin splitting of the surface electronic structure is effectively tuned. By analyzing the gate voltage dependence of HDPC, we can unambiguously identify the surface polarity and the surface electronic structure of Bi2O2Se. The large HDPC in Bi2O2Se nanosheets and its efficient electrical tuning demonstrate that 2D Bi2O2Se nanosheets may provide a good platform for opto-spintronics devices.

5.
Materials (Basel) ; 16(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37049163

RESUMO

Flexible CZTSSe solar cells have attracted much attention due to their earth-abundant elements, high stability, and wide application prospects. However, the environmental problems caused by the high toxicity of the Cd in the buffer layers restrict the development of flexible CZTSSe solar cells. Herein, we develop a Cd-free flexible CZTSSe/ZnO solar cell. The influences of the ZnO films on device performances are investigated. The light absorption capacity of flexible CZTSSe solar cells is enhanced due to the removal of the CdS layer. The optimal thickness of the ZnO buffer layers and the appropriate annealing temperature of the CZTSSe/ZnO are 100 nm and 200 °C. Ultimately, the optimum flexible CZTSSe/ZnO device achieves an efficiency of 5.0%, which is the highest efficiency for flexible CZTSSe/ZnO solar cells. The systematic characterizations indicate that the flexible CZTSSe/ZnO solar cells based on the optimal conditions achieved quality heterojunction, low defect density and better charge transfer capability. This work provides a new strategy for the development of the environmentally friendly and low-cost flexible CZTSSe solar cells.

6.
Artigo em Inglês | MEDLINE | ID: mdl-36753313

RESUMO

With the advantages of low cost, high safety, and environmental friendliness, quasi-solid-state zinc-ion microbatteries (ZIMBs) have received widespread attention in the field of flexible wearable devices and on-chip integratable energy storage. However, hysteresis Zn-ion transport kinetics and inhomogeneous growth of the zinc anode result in the poor capacity reversibility and cycling stability. Herein, a quasi-solid-state planar zinc-ion cell was developed by employing a vertical graphene (VG) film as an effective conductive modification layer for both the cathode and anode. The VG distinctly induces uniform Zn deposition/stripping, accelerates the charge transport, and enhances the adhesion between the active materials and current collectors. As a result, planar Zn@VG//MnO2@VG exhibits a high areal capacity of 159 µAh cm-2, a remarkably high areal energy/power density of 201.5 µWh cm-2/67.16 µW cm-2, and a high capacity retention of 95.6% at a bending angle of 180°. The proposed facile strategy for electrode modification provides a new insight into the design of high-performance flexible and planar ZIMBs.

7.
Animals (Basel) ; 12(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36077992

RESUMO

The pharmacological pathway of para-toluenesulfonamide (PTS) restricts the kinase activity of the mammalian target of rapamycin, potentially leading to reductions in cell division, cell growth, cell proliferation, and inflammation. These pathways have a critical effect on tumorigenesis. We aimed to examine the antitumor effect of PTS or PTS combined with cisplatin on canine melanoma implanted in BALB/c nude mice by estimating tumor growth, apoptosis expression, inflammation, and metastasis. The mice were randomly divided into four groups: control, cisplatin, PTS, and PTS combined with cisplatin. Mice treated with PTS or PTS combined with cisplatin had retarded tumor growth and increased tumor apoptosis through the enhanced expression of cleaved caspase 3 and extracellular signal-regulated kinase phosphorylation, decreased inflammatory cytokine levels, reduced inflammation-related factors, enhanced anti-inflammation-related factors, and inhibition of metastasis-related factors. Mice treated with PTS combined with cisplatin exhibited significantly retarded tumor growth, reduced tumor size, and increased tumor inhibition compared with those treated with cisplatin or PTS alone. PTS or PTS combined with cisplatin could retard canine melanoma growth and inhibit tumorigenesis. PTS and cisplatin were found to have an obvious synergistic tumor-inhibiting effect on canine melanoma. PTS alone and PTS combined with cisplatin may be antitumor agents for canine melanoma treatment.

8.
Langmuir ; 38(34): 10575-10584, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35984945

RESUMO

Cross-contamination during pharmaceutical drug manufacturing can result in expensive recalls. To counter that, companies spend significant time and resources to ensure equipment cleanliness, often relying on the compound solubility data in various solvents as the main indicator of cleaning success. The aim of this work is to provide an alternative way to analyze the fouling and cleaning of surfaces in pharmaceutical manufacturing processes by using the quartz crystal microbalance with dissipation (QCM-D) and Raman spectroscopy. In this study, we chose an active pharmaceutical ingredient (API), sitagliptin phosphate monohydrate (SIT), as the model drug compound and observed its adsorption and desorption on stainless steel (SS2343), borosilicate glass (glass), and polytetrafluoroethylene (PTFE) surfaces. SIT was selected as the model API since it is a product manufactured on a large scale and is part of the widely used dipeptidyl peptidase-IV inhibitor class of oral hypoglycemics used to treat type 2 diabetes mellitus, while the chosen surfaces mimic the wall materials of manufacturing equipment and components such as reactors, transfer lines, and valves. Both the QCM-D and Raman spectroscopy results show the highest physisorption on PTFE, followed by SS2343 and glass. Additionally, QCM-D revealed a harder removal of SIT from SS2343 compared to glass and PTFE. Raman analysis of the chemical interactions disclosed C-F and C═O bond interactions between SIT and the surfaces, and the lack of a peak shift suggested dipole-dipole interactions. Furthermore, contact angle measurements indicate that hydrophobic attraction contributed to SIT adhesion to the PTFE surface. Subsequently, SIT coverage upon deposition on a PTFE surface has a significantly smaller surface area than on SS2343 and glass due to surface hydrophobicity, hence resulting in a longer removal time. These results provide a practical use of QCM-D and Raman spectroscopy to enhance the understanding of fouling and improve the cleaning of complex small molecules on relevant surfaces during the pharmaceutical manufacturing process.


Assuntos
Diabetes Mellitus Tipo 2 , Técnicas de Microbalança de Cristal de Quartzo , Adsorção , Humanos , Preparações Farmacêuticas , Politetrafluoretileno , Fosfato de Sitagliptina , Análise Espectral Raman , Propriedades de Superfície
9.
Small ; 18(22): e2201347, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35510960

RESUMO

Flexible Cu2 ZnSn(S,Se)4 (CZTSSe) solar cells show great potential due to non-toxicity and low cost. The quality of CZTSSe absorber suffering from the high-temperature selenization process is the key to overcoming open-circuit voltage (VOC ) deficit and obtaining high efficiency. In this work, the authors develop a selenization technique to improve the quality of the CZTSSe layer by pre-evaporation selenization. This method provides saturated selenium vapor at the beginning of the selenization process to promote the crystallization process. The oversaturated selenium source greatly shortens the annealing time at high temperatures. The prepared CZTSSe films have larger grains and fewer voids. The measurement of the space charge limited current shows that the defect density of the CZTSSe absorber is significantly reduced from 4.43 × 1013  cm-3 to 3.46 × 1013 cm-3 . Electrical tests show that the devices have better charge separation at the interface, resulting in a charge recombination lifetime, increasing from 133 to 197 µs. The power conversion efficiency of the flexible CZTSSe solar cell reaches 10.24% with VOC and the fill factor enhances to 463 mV and 62%, respectively. The safe non-toxicity and efficient selenization method is expected to provide a new strategy for high-efficiency flexible CZTSSe solar cells.

10.
Opt Express ; 30(9): 15085-15095, 2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35473239

RESUMO

The photoinduced inverse spin Hall effect (PISHE) has been studied in three dimensional (3D) topological insulator (TI) Bi2Te3 thin films with different thicknesses (3, 5, 12 and 20 quintuple layer (QL)). The sign of the PISHE current flips only once in the 3- and 20-QL Bi2Te3 films, but it flips three times in the 5-, 7- and 12-QL samples. The three-times sign flip is due to the superposition of the PISHE current of the top and bottom surface states in Bi2Te3 films. By analyzing the x-ray photoelectron spectroscopy (XPS) of the Bi2Te3 films, we find that the top surface of the 3- and 20-QL Bi2Te3 films are severely oxidized, leading to only one sign flip in the PISHE. The PISHE contributed by the top and bottom surface states in Bi2Te3 films have been successfully separated by fitting a theoretical model to the PISHE current. The impact of the bulk states on PISHE current has been determined. The PISHE current is also measured at different light powers, and all the measurement results are in good agreement with the theoretical model. In addition, it is found that the PISHE current in Bi2Te3 films grown on Si substrate is more than two orders larger than that grown on SrTiO3 substrates, which can be attributed to the larger absorption coefficient for Bi2Te3/Si samples. It is revealed that the PISHE current in 3D TI Bi2Te3 is as large as 140 nA/W in the 3-QL Bi2Te3 film grown on Si substrate, which is more than one order larger than that reported in GaAs/AlGaAs heterojunction (about 2 nA/W) and GaN/AlGaN heterojunction (about 1.7 nA/W). The giant PISHE current demonstrates that the TIs with strong SOC may have good application prospects in spintronic devices with high spin-to-charge conversion efficiency.

11.
RSC Adv ; 12(4): 2292-2299, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35425258

RESUMO

In order to achieve low-cost, high efficiency and stable photoelectric devices, two-dimensional (2D) inorganic halide perovskite photosensitive layers need to cooperate with other functional layers. Here, we investigate the structure, stability and optical properties of perovskite and transition metal dichalcogenide (TMD) heterostructures using first-principles calculations. Firstly, Cs2PbX4-PtSe2 (X = Cl, Br, I) heterostructures are stable because of negative interface binding energy. With the halogen varying from Cl to I, the interface binding energies of Cs2PbX4-PtSe2 heterostructures decrease rapidly. 2D Cs2PbCl4-PtSe2, Cs2PbBr4-PtSe2 and Cs2PbI4-PtSe2 heterostructures have an indirect bandgap with the value of 1.28, 1.02, and 1.29 eV, respectively, which approach the optimal bandgap (1.34 eV) for solar cells. In the contact state, the electrons transfer from the PtSe2 monolayer to Cs2PbX4 monolayer and only the Cs2PbBr4-PtSe2 heterostructure maintains the type-II band alignment. The Cs2PbBr4-PtSe2 heterostructure has the strongest charge transfer among the three Cs2PbX4-PtSe2 heterostructures because it has the lowest tunnel barrier height (ΔT) and the highest potential difference value (ΔEP). Furthermore, the light absorption coefficient of Cs2PbX4-MSe2 heterostructures is at least two times higher than that of monolayer 2D inorganic halide perovskites. With the halogen varying from Cl to I, the light absorption coefficients of the Cs2PbX4-PtSe2 heterostructures increase rapidly in the visible region. Above all, the Cs2PbX4-MSe2 heterostructures have broad application prospects in photodetectors, solar cells and other fields.

12.
ACS Appl Mater Interfaces ; 14(10): 12385-12394, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35234027

RESUMO

Photodetectors (PDs) for weak light signal detection have wide applications for optical communication and imaging. Antimony sulfide (Sb2S3) as a nontoxic and stable light-sensitive material becomes a promising candidate for weak light PDs, which are developing in the direction of high response, high speed, and low cost. Herein, a self-powered Sb2S3 PD with the structure of FTO/TiO2/Sb2S3/Au is developed to achieve weak light detection for 300-750 nm visible light. We control the Sb2S3 thickness with about 460 nm to match depletion region width (438 nm) and obtain an excellent photoresponsivity and 3 dB bandwidth. Furtherly, we prepare pyramid structure polydimethylsiloxane (PDMS) on the illuminating surface to enhance the performance of weak light detection by light-trapping effects. The photocurrent of Sb2S3 PD with 20 µm-sized PDMS texture achieves 13.6% improvement compared with the control one. Under weak 530 nm light illumination of 1 µW cm-2, the self-powered Sb2S3 PD with PDMS achieves high responsivity (3.41 A W-1), large detectivity (2.84 × 1013 Jones), and ultrafast speed (15 µs). The present Sb2S3 PD and light-trapping strategy are expected to provide an alternative to future commercial weak light detection applications.

13.
Adv Sci (Weinh) ; 9(9): e2104689, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35072352

RESUMO

Lithium (Li) has garnered considerable attention as an alternative anodes of next-generation high-performance batteries owing to its prominent theoretical specific capacity. However, the commercialization of Li metal anodes (LMAs) is significantly compromised by non-uniform Li deposition and inferior electrolyte-anode interfaces, particularly at high currents and capacities. Herein, a hierarchical three-dimentional structure with CoSe2 -nanoparticle-anchored nitrogen-doped carbon nanoflake arrays is developed on a carbon fiber cloth (CoSe2 -NC@CFC) to regulate the Li nucleation/plating process and stabilize the electrolyte-anode interface. Owing to the enhanced lithiophilicity endowed by CoSe2 -NC, in situ-formed Li2 Se and Co nanoparticles during initial Li nucleation, and large void space, CoSe2 -NC@CFC can induce homogeneous Li nucleation/plating, optimize the solid electrolyte interface, and mitigate volume change. Consequently, the CoSe2 -NC@CFC can accommodate Li with a high areal capacity of up to 40 mAh cm-2 . Moreover, the Li/CoSe2 -NC@CFC anodes possess outstanding cycling stability and lifespan in symmetric cells, particularly under ultrahigh currents and capacities (1600 h at 10 mA cm-2 /10 mAh cm-2 and 5 mA cm-2 /20 mAh cm-2 ). The Li/CoSe2 -NC@CFC//LiFePO4 full cell delivers impressive long-term performance and favorable flexibility. The developed CoSe2 -NC@CFC provides insights into the development of advanced Li hosts for flexible and stable LMAs.

14.
Nat Commun ; 12(1): 3107, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34035256

RESUMO

Environment-friendly flexible Cu2ZnSn(S,Se)4 (CZTSSe) solar cells show great potentials for indoor photovoltaic market. Indoor lighting is weak and multi-directional, thus the researches of photovoltaic device structures, techniques and performances face new challenges. Here, we design symmetrical bifacial CZTSSe solar cells on flexible Mo-foil substrate to efficiently harvest the indoor energy. Such devices are fabricated by double-sided deposition techniques to ensure bifacial consistency and save cost. We report 9.3% and 9% efficiencies for the front and back sides of the flexible CZTSSe solar cell under the standard sun light. Considering the indoor environment, we verify weak-light response performance of the devices under LED illumination and flexibility properties after thousands of bending. Bifacial CZTSSe solar cells in parallel achieve the superposition of double-sided output current from multi-directional light, significantly enhancing the area utilization rate. The present results and methods are expected to expand indoor photovoltaic applications.

15.
Nanoscale ; 13(21): 9834-9842, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34032261

RESUMO

As a key factor for fast-charging lithium-ion batteries (LIBs), high-rate anode materials that can recharge in a few minutes have aroused increasing attention. However, high-rate performance is always accompanied by low theoretical capacities, such as the widely known high-rate electrode of Li4Ti5O12 (175 mA h g-1), which severely limits its large-scale implementation in the development of high power density LIBs. Here, we report a modified close-spaced thermal evaporation process to deposit 3D-structured Sb2Se3 films (3D-SSF) with tunable morphology as an additive-free anode for LIBs. After a high-rate activation process, 3D-SSF exhibits a flatter discharge plateau than the reported results and could deliver a high capacity of 471 mA h g-1 at an ultrahigh current density of 21 440 mA g-1, which is superior to the widely known high-rate Li4Ti5O12 anode (over 150 mA h g-1 at 8750 mA g-1). Moreover, we reveal a current-regulated Li-ion storage mechanism where 3D-SFF undergoes a synergistic conversion and alloying reaction at low current densities, while an alloying reaction-dominated process at high rates. Beyond that, full batteries with excellent rate performance were successfully assembled by pairing with homemade LiFePO4 (LFP) as the cathode.

16.
Ther Innov Regul Sci ; 55(4): 872-880, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33904126

RESUMO

BACKGROUND: To promote the efficiency and quality of registration for medical products, the Asia-Pacific Economic Cooperation (APEC) Regulatory Harmonization Steering Committee (RHSC) has implemented a 2020 roadmap to promote the concept of GRM since 2011. Key outcomes of this roadmap are discussed in this article to provide recommendations for improved regulatory practices and accelerated regulatory convergence. METHODS: Adoption of relevant guidelines and delivery of training programs from the APEC Training Centers of Excellence for Regulatory Science (CoEs) have played a key role to promote capacity building, cooperation and convergence in good review practices (GRevPs) and good submission practices (GSubPs) for medical products among APEC economies. A key performance indicator (KPI) survey among the drug regulatory authorities (RAs) of APEC economies was conducted to understand the progress of this roadmap. RESULTS: The CoE programs have provided a unique opportunity to promote dialogues between regulatory authorities and industry and efficiently disseminated the concept of GRM among APEC economies. The results of the KPI survey indicated significant progress in the status of implementing GRevPs over the last ten years. CONCLUSIONS: To accelerate regulatory convergence among APEC economies, it is necessary to promote mutual trust and cooperation in approval of medical products over the time. Continuous training in GRevPs and GSubPs through the CoE platform would set the stage to achieve the goal in the next decade.


Assuntos
Inquéritos e Questionários , Ásia
17.
ACS Appl Mater Interfaces ; 12(15): 18091-18100, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32212669

RESUMO

The circular photogalvanic effect (CPGE) provides a method utilizing circularly polarized light to control spin photocurrent and will also lead to novel opto-spintronic devices. The CPGE of three-dimensional topological insulator Bi2Te3 with different substrates and thicknesses has been systematically investigated. It is found that the CPGE current can be dramatically tuned by adopting different substrates. The CPGE current of the Bi2Te3 films on Si substrates are more than two orders larger than that on SrTiO3 substrates when illuminated by 1064 nm light, which can be attributed to the modulation effect due to the spin injection from Si substrate to Bi2Te3 films, larger light absorption coefficient, and stronger inequivalence between the top and bottom surface states for Bi2Te3 films grown on Si substrates. The excitation power dependence of the CPGE current of Bi2Te3 films on Si substrates shows a saturation at high power especially for thicker samples, whereas that on SrTiO3 substrates almost linearly increases with excitation power. Temperature dependence of the CPGE current of Bi2Te3 films on Si substrates first increases and then decreases with decreasing temperature, whereas that on SrTiO3 substrates changes monotonously with temperature. These interesting phenomena of the CPGE current of Bi2Te3 films on Si substrates are related to the spin injection from Si substrates to Bi2Te3 films. Our work not only intrigues new physics but also provides a method to effectively manipulate the helicity-dependent photocurrent via spin injection.

18.
Int J Pharm ; 576: 118983, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31874195

RESUMO

This study reports a novel quercetin nanorod/microcrystalline cellulose (MCC) formulation prepared by fluid bed coating crystallization technique. The process comprises fluidized bed spray coating of quercetin acetone solution onto MCC particles, solvent evaporation and crystallization of quercetin nanorods on MCC surface. Depending on the quercetin solution concentration, quercetin nanorods with 100-300 nm in diameter and 1-3 µm in length were obtained. Owing to the small particle size and large surface area, a higher dissolution rate was achieved for quercetin nanorods in contrast to the raw quercetin, which therefore led to higher antioxidant activities. In addition, the obtained quercetin nanorod/MCC formulation exhibited a good storage stability within 12 months. The developed quercetin nanorod/MCC formulation could be used for further pharmaceutical dosage or food supplements processing.


Assuntos
Celulose/química , Nanotubos/química , Quercetina/química , Química Farmacêutica/métodos , Cristalização/métodos , Composição de Medicamentos/métodos , Tamanho da Partícula , Solubilidade
19.
Opt Express ; 27(2): 965-979, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30696185

RESUMO

We proposed a high-performance optical coherence velocimeter (OCV) based on broadband optical interference which achieves spatial resolution from interference cancellation or enhancement of different components of the broadband light. There is a challengeable issue for OCV that the interference fringes become blurred when the velocity of detected object is relatively large, hindering the pace of OCV application in high-velocity field. To resolve this, the relationship between blurry coefficient and OCV system parameters (e.g., exposure time, central wavelength, bandwidth of source) was derived. It was found that blurry coefficient changed with oscillatory decay form and reached the minimum at each order blurry velocity. It showed that maximum measurable velocity of OCV systems could reach 10th order blurry velocity. The measurement of vibration of the loudspeaker driven by a function signal generator was employed to experimentally verify the velocity measurement performance of the system. The experiment demonstrated that the developed OCV can provide large velocity measurement ranges from static to 25.2 mm/s with nanometer-level precision and maximum measurable vibration frequency of up to 50 kHz. However, in theory, the theoretical maximum measurable velocity can be up to 1.06 m/s for current OCV configuration. The OCV has high precision, large dynamic range, and high-velocity measurement capability, making it attractive for applications in mechanical structure vibration monitoring and acoustic measurement.

20.
Front Chem ; 7: 869, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31970147

RESUMO

Self-supported electrodes represent a novel architecture for better performing lithium ion batteries. However, lower areal capacity restricts their commercial application. Here, we explore a facial strategy to increase the areal capacity without sacrificing the lithium storage performance. A hierarchical CuO-Ge hybrid film electrode will not only provide high areal capacity but also outstanding lithium storage performance for lithium ion battery anode. Benefiting from the favorable structural advance as well as the synergic effect of the Ge film and CuO NWs array, the hybrid electrode exhibits a high areal capacity up to 3.81 mA h cm-2, good cycling stability (a capacity retention of 90.5% after 150 cycles), and superior rate performance (77.4% capacity remains even when the current density increased to 10 times higher).

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