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1.
Sci Total Environ ; 933: 173022, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38719049

RESUMO

Urban areas are increasingly vulnerable to sudden flooding disasters caused by intense rainfall and high imperviousness degree, resulting in great economic losses and human casualties. Interactions between rainfall data and urban catchment characteristics highlight the urgent need of accurate and effective precipitation data to apply in reliable hydrological simulations. However, it remains a challenge to obtain accurate rainfall datasets on such small scales in urban areas. As satellite remote sensing is the only method that can achieve global observation, it is important to evaluate satellite precipitation products in their ability to accurately capture intense precipitation on urban flood scales. This study evaluates the performance of the latest version 06B (V06B) Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG) in North China Plain, with using the Radar-Gauge merged precipitation estimates as reference data. First, it could be concluded that IMERG fails to accurately estimate precipitation in the whole study area, having the problem of overestimating light precipitation and underestimating heavy precipitation. Second, results show that IMERG has poor ability to capture heavy precipitation on small scales, with the percentage of Hit nearly 0 and the percentage of Miss higher than 40 % for all the precipitation cases. Third, with the expansion of heavy precipitation centers' coverage, the problem of IMERG not to detect heavy precipitation gets mitigated, with the percentage of Miss decreasing by 14 % (19 %). However, the ability to capture both spatial location and precipitation intensity is still not good, the percentage of Hit ranging from 0.05 % to 7 %, without obvious improvement. When IMERG is able to capture the center of strong precipitation, it also tends to overestimate the weak precipitation around the center of strong precipitation. Results of this study provide an improved understanding of how well the V06B IMERG products capture the heavy precipitation center at small scales in urban areas, which will be useful for both developers and users of IMERG.

2.
J Psychol ; 158(2): 134-146, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37812502

RESUMO

This study aimed to examine the mediating effect of life satisfaction in the relationship between hope and internalizing/externalizing behaviors among a sample of 1170 Chinese adolescents (mean age = 14.80 ± 1.76 years, 46.24% boys). Through the use of structural equation modeling (SEM), the study revealed a negative association between hope and internalizing/externalizing behaviors. Furthermore, the findings indicated that life satisfaction partially mediated the relationship between hope and internalizing/externalizing behaviors. The findings highlight the significance of hope and life satisfaction as protective factors in reducing internalizing/externalizing behaviors among adolescents. These results also contribute to the existing research on the role of hope and emphasize the importance of fostering hope and enhancing life satisfaction in prevention and intervention programs targeting adolescent internalizing/externalizing behaviors.


Assuntos
Comportamento do Adolescente , Esperança , Satisfação Pessoal , Adolescente , Feminino , Humanos , Masculino , China , População do Leste Asiático
3.
Chem Soc Rev ; 52(20): 6938-6956, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37791542

RESUMO

Photocatalytic ammonia synthesis (PAS) is an emerging zero carbon emission technology, which is critical for mitigating energy crises and achieving carbon neutrality. Herein, we summarize the recent advances and challenges in PAS from an engineering perspective based on its whole chain process, i.e., materials engineering, structure engineering and reaction engineering. For materials engineering, we discuss the commonly used photocatalytic materials including metal oxides, bismuth oxyhalides and graphitic carbon nitride and emerging materials, such as organic frameworks, along with the analysis of their characteristics and regulation methods to enhance the PAS performance. For structure engineering, the design of photocatalysts is described in terms of morphology, vacancy and band, corresponding to the crystal, atom and electron scales, respectively. Moreover, the structure-performance relationship of photocatalysts has been deeply explored in this section. For reaction engineering, we identify three key processes from the chemical reaction and mass transfer, i.e., nitrogen activation, molecule transfer and electron transfer, to intensify and optimize the PAS reaction. Hopefully, this review will provide a novel paradigm for the design and preparation of high-efficiency ammonia synthesis photocatalysts and inspire the practical application of PAS.

4.
Ground Water ; 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37605321

RESUMO

Significant efforts have been expended for improved characterization of hydraulic conductivity (K) and specific storage (Ss ) to better understand groundwater flow and contaminant transport processes. Conventional methods including grain size analyses (GSA), permeameter, slug, and pumping tests have been utilized extensively, while Direct Push-based Hydraulic Profiling Tool (HPT) surveys have been developed to obtain high-resolution K estimates. Moreover, inverse modeling approaches based on geology-based zonations, and highly parameterized Hydraulic Tomography (HT) have also been advanced to map spatial variations of K and Ss between and beyond boreholes. While different methods are available, it is unclear which one yields K estimates that are most useful for high resolution predictions of groundwater flow. Therefore, the main objective of this study is to evaluate various K estimates at a highly heterogeneous field site obtained with three categories of characterization techniques including: (1) conventional methods (GSA, permeameter, and slug tests); (2) HPT surveys; and (3) inverse modeling based on geology-based zonations and highly parameterized approaches. The performance of each approach is first qualitatively analyzed by comparing K estimates to site geology. Then, steady-state and transient groundwater flow models are employed to quantitatively assess various K estimates by simulating pumping tests not used for parameter estimation. Results reveal that inverse modeling approaches yield the best drawdown predictions under both steady and transient conditions. In contrast, conventional methods and HPT surveys yield biased predictions. Based on our research, it appears that inverse modeling and data fusion are necessary steps in predicting accurate groundwater flow behavior.

5.
J Am Chem Soc ; 145(11): 6057-6066, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36888741

RESUMO

The development of efficient photocatalysts for N2 fixation to produce NH3 under ambient conditions remains a great challenge. Since covalent organic frameworks (COFs) possess predesignable chemical structures, good crystallinity, and high porosity, it is highly significant to explore their potential for photocatalytic nitrogen conversion. Herein, we report a series of isostructural porphyrin-based COFs loaded with Au single atoms (COFX-Au, X = 1-5) for photocatalytic N2 fixation. The porphyrin building blocks act as the docking sites to immobilize Au single atoms as well as light-harvesting antennae. The microenvironment of the Au catalytic center is precisely tuned by controlling the functional groups at the proximal and distal positions of porphyrin units. As a result, COF1-Au decorated with strong electron-withdrawing groups exhibits a high activity toward NH3 production with rates of 333.0 ± 22.4 µmol g-1 h-1 and 37.0 ± 2.5 mmol gAu-1 h-1, which are 2.8- and 171-fold higher than that of COF4-Au decorated with electron-donating functional groups and a porphyrin-Au molecular catalyst, respectively. The NH3 production rates could be further increased to 427.9 ± 18.7 µmol g-1 h-1 and 61.1 ± 2.7 mmol gAu-1 h-1 under the catalysis of COF5-Au featuring two different kinds of strong electron-withdrawing groups. The structure-activity relationship analysis reveals that the introduction of electron-withdrawing groups facilitates the separation and transportation of photogenerated electrons within the entire framework. This work manifests that the structures and optoelectronic properties of COF-based photocatalysts can be finely tuned through a rational predesign at the molecular level, thus leading to superior NH3 evolution.

6.
ACS Appl Mater Interfaces ; 15(1): 1053-1062, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36538610

RESUMO

Enhancing the photogenerated electrons transfer efficiency is crucial for photocatalytic reactions. Herein, a dual-ligand-induced push-pull effect was manipulated to intensify the transfer of photogenerated electrons between organic ligands and metal clusters using NH2-MIL-125(Ti), a kind of Ti-based metal-organic framework (MOF), as the model system. The dual-ligand MOF, NH2/Cl-MIL-125, was designed and synthesized based on the Hammett constant (σm), in which -NH2 (σm = -0.16) and -Cl (σm = 0.37) were selected as the electron-pushing group and the electron-pulling group, respectively. Meanwhile, -CH3 (σm = -0.07, electron-pushing) and -H (σm = 0, neither electron-pushing nor electron-pulling) were selected as the reference groups to prepare NH2/CH3-MIL-125 and NH2/H-MIL-125, respectively, to validate the electron push-pull effect. NH2/Cl-MIL-125 (5.32 mmol g-1 h-1) exhibits a higher photocatalytic H2 evolution activity than single-ligand NH2-MIL-125 (1.93 mmol g-1 h-1), NH2/CH3-MIL-125 (4.45 mmol g-1 h-1), and NH2/H-MIL-125 (4.73 mmol g-1 h-1) under full-spectrum irradiation. The result can be attributed to the electron push-pull effect between -NH2 and -Cl, which boosts the electron transfer along the ligand-metal-ligand direction. Our dual-ligand-induced push-pull strategy for enhancing the electron transfer may offer some novel insights into the rational design and synthesis of photocatalysts for many other reactions.

7.
J Interpers Violence ; 37(13-14): NP12238-NP12259, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-33685274

RESUMO

Existing theories and empirical studies have evidenced the association between bullying victimization and bullying perpetration. However, it is still unclear what factors mitigate or alter this risk linkage between bullying victimization and bullying perpetration to reduce bullying incidents. Guided by the social-ecological theory, this study used a longitudinal design to examine the moderating role of school climate in the association between bullying victimization and bullying perpetration at both the within-person and between-person levels among Chinese adolescents across a 1-year period. Participants included 2,997 Chinese adolescents (Mage = 14.9, 49.7% male) from 5 secondary schools. Results suggested that students who experienced high levels of bullying victimization were also involved in high levels of bullying perpetration over time (i.e., the positive within-person effect of bullying victimization on bullying perpetration). Results also showed that the between-person level of perceived school climate interacted with the within-person level of bullying victimization to predict the within-person level of bullying perpetration (i.e., cross-level effects). More specifically, the magnitude of the positive association between bullying victimization and bullying perpetration at the within-person level was mitigated among students with higher perceptions of school climate at the between-person level. Findings of the study highlighted the causal effect of bullying victimization on bullying perpetration and the buffering role of perceived school climate in the longitudinal association between bullying victimization and perpetration, which was consistent with the risk-buffering model but not the healthy context paradox hypothesis. Furthermore, the findings provided implications for bullying prevention and intervention services by using multitiered systems of support in bullying prevention efforts and highlights the need for promoting positive school climate.


Assuntos
Bullying , Vítimas de Crime , Adolescente , Feminino , Humanos , Masculino , Instituições Acadêmicas , Meio Social , Estudantes
8.
Research (Wash D C) ; 2021: 9798564, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34405143

RESUMO

The rational design of an outer shell is of great significance to promote the photocatalytic efficiency of core-shell structured photocatalysts. Herein, a covalent organic framework (COF) nanoshell was designed and deposited on the cadmium sulfide (CdS) core surface. A typical COF material, TPPA, featuring exceptional stability, was synthesized through interfacial polymerization using 1, 3, 5-triformylphloroglucinol (TP) and p-phenylenediamine (PA) as monomers. The nanoshell endows the CdS@TPPA nanosphere with ordered channels for unimpeded light-harvesting and fast diffusion of reactants/products and well-defined modular building blocks for spatially charge separation. Moreover, the heterojunction formed between CdS and TPPA can further facilitate the effective charge separation at the interface via lower exciton binding energy compared with that of pristine TPPA. By modulating the thickness of TPPA nanoshell, the CdS@TPPA nanosphere photocatalyst with the nanoshell thickness of about 8 ± 1 nm exhibits the highest photocatalytic H2 evolution of 194.1 µmol h-1 (24.3 mmol g-1 h-1, 8 mg), which is superior to most of the reported COF-based photocatalysts. The framework nanoshell in this work may stimulate the thinking about how to design advanced shell architecture in the core-shell structured photocatalysts to achieve coordinated charge and molecule transport.

9.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-862601

RESUMO

Objective@#To explore relationship among bullying victimization, psychological traits and suicide ideation of middle school students, and to provide suggestions for school bullying and suicide prevention for adolescents.@*Methods@#A total of 3 635 students of 7-9th grade from 5 junior middle schools were enrolled and investigated with the Olweus Bully/Victim Questionnaire (OBVQ), psychological traits questionnaire for middle school students and suicide ideation questionnaire.@*Results@#Prevalence of bullying victimization was 28.34% of middle school students, while the prevalence of verbal, relational and physical bullying were 22.59%, 12.05% and 7.54%, respectively. Boys had significantly higher rates of bullying victimization than girls (χ2=88.92,94.29,7.69,P<0.01). Bullying victimization was positively associated with suicidal ideation (r=0.21, P<0.01), while associated with psychological traits (r=-0.17, -0.22, P<0.01). Psychological traits had a moderating effect on the relationship between bullying victimization and suicidal ideation (β=-0.04, P<0.05).@*Conclusion@#Psychological traits can buffer the adverse effects of bullying victimization on suicidal ideation, and the critical role of psychological traits in the maintenance and development of adolescent mental health should be emphasized.

10.
J Contam Hydrol ; 229: 103559, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31784037

RESUMO

The concept of chaotic advection is a novel approach that has the potential to overcome some of the challenges associated with mixing of reagents that commonly occur when injection based in situ treatment techniques are used. The rotated potential mixing (RPM) flow system is one configuration which has been theorized to achieve chaotic advection in porous media, and enhance reagent mixing by periodically re-oriented dipole pumping at a series of radial wells. Prior to field implementation of chaotic advection, the selection of an RPM flow protocol will likely require a numerical model that can adequately represent groundwater flow within the zone of interest. As expected, the hydraulic conductivity (K) field is the most critical input requirement for the selected groundwater flow model. Hydraulic tomography (HT) is an innovative characterization approach that has shown potential to provide information on a K field. In this investigation, we explored whether the same well system required to invoke chaotic advection can also be applied in a HT analysis, and evaluated the use of the generated K tomogram for the selection of RPM flow parameters that can enhance reagent mixing. A series of dipole pumping tests were conducted within an area of interest as defined by the limits of the circular network of eight injection/extraction wells used to invoke chaotic advection. Hydraulic head data collected from independent dipole pumping tests were used in an inverse model to perform steady-state hydraulic tomography (SSHT) analysis to generate a K tomogram. Both the K tomogram and an effective parameter approach (i.e., a single K value assigned across the entire spatial domain as determined by single well pumping and slug tests) produced estimates of hydraulic head that closely resembled those observed due to the relative homogeneous nature of the aquifer and the small spatial scale of the area of interest. In contrast, particle tracking results showed that incorporating a heterogeneous K field significantly enhanced the spatial distribution of particle trajectories indicative of reagent mixing. These findings support the hypothesis that the same well system used to invoke chaotic advection can be combined with SSHT analysis as a viable site characterization tool for delineating the spatial variability of K. Incorporating this K tomogram in a groundwater flow model with a particle tracking engine can be used as a design tool to aid in the selection of a site-specific RPM flow protocol to achieve enhanced reagent mixing.


Assuntos
Água Subterrânea , Modelos Teóricos , Porosidade , Tomografia , Movimentos da Água , Poços de Água
11.
Sensors (Basel) ; 17(12)2017 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-29168775

RESUMO

Motion capture of the human body potentially holds great significance for exoskeleton robots, human-computer interaction, sports analysis, rehabilitation research, and many other areas. Dielectric elastomer sensors (DESs) are excellent candidates for wearable human motion capture systems because of their intrinsic characteristics of softness, light weight, and compliance. In this paper, DESs were applied to measure all component motions of the wrist joints. Five sensors were mounted to different positions on the wrist, and each one is for one component motion. To find the best position to mount the sensors, the distribution of the muscles is analyzed. Even so, the component motions and the deformation of the sensors are coupled; therefore, a decoupling method was developed. By the decoupling algorithm, all component motions can be measured with a precision of 5°, which meets the requirements of general motion capture systems.


Assuntos
Dispositivos Eletrônicos Vestíveis , Elastômeros , Desenho de Equipamento , Movimento (Física) , Articulação do Punho
12.
Artigo em Inglês | MEDLINE | ID: mdl-27529262

RESUMO

Exposure to malachite green (MG) may pose great health risks to humans; thus, it is of prime importance to develop fast and robust methods to quantitatively screen the presence of malachite green in water. Herein the application of extractive electrospray ionization mass spectrometry (EESI-MS) has been extended to the trace detection of MG within lake water and aquiculture water, due to the intensive use of MG as a biocide in fisheries. This method has the advantage of obviating offline liquid-liquid extraction or tedious matrix separation prior to the measurement of malachite green in native aqueous medium. The experimental results indicate that the extrapolated detection limit for MG was ~3.8 µg·L(-1) (S/N = 3) in lake water samples and ~0.5 µg·L(-1) in ultrapure water under optimized experimental conditions. The signal intensity of MG showed good linearity over the concentration range of 10-1000 µg·L(-1). Measurement of practical water samples fortified with MG at 0.01, 0.1 and 1.0 mg·L(-1) gave a good validation of the established calibration curve. The average recoveries and relative standard deviation (RSD) of malachite green in lake water and Carassius carassius fish farm effluent water were 115% (6.64% RSD), 85.4% (9.17% RSD) and 96.0% (7.44% RSD), respectively. Overall, the established EESI-MS/MS method has been demonstrated suitable for sensitive and rapid (<2 min per sample) quantitative detection of malachite green in various aqueous media, indicating its potential for online real-time monitoring of real life samples.


Assuntos
Aquicultura , Corantes de Rosanilina/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Água/química , Animais , Humanos , Limite de Detecção , Reprodutibilidade dos Testes
13.
J Agric Food Chem ; 57(20): 9356-64, 2009 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-19788186

RESUMO

Without any sample pretreatment, mass spectral fingerprints of 486 dried sea cucumber slices were rapidly recorded in the mass range of m/z 50-800 by using surface desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS). A set of 162 individual sea cucumbers (Apostichopus japonicus Selenka) grown up in 3 different geographical regions (Weihai: 59 individuals, 177 slices; Yantai: 53 individuals, 159 slices; Dalian: 50 individuals, 150 slices;) in north China sea were successfully differentiated according to their habitats both by Principal Components Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA) of the mass spectral raw data, demonstrating that DAPCI-MS is a practically convenient tool for high-throughput differentiation of sea cucumber products. It has been found that the difference between the body wall tissue and the epidermal tissue is heavily dependent on the habitats. The experimental data also show that the roughness of the sample surface contributes to the variance of the signal levels in a certain extent, but such variance does not fail the differentiation of the dried sea cucumber samples.


Assuntos
Espectrometria de Massas/métodos , Pepinos-do-Mar/química , Alimentos Marinhos/análise , Animais , China , Controle de Qualidade , Alimentos Marinhos/normas
14.
J Biomed Mater Res A ; 84(2): 523-34, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17618503

RESUMO

In the present study, surface functional groups of titanium surfaces gone through different treatments, including acid etched treatment (AE), nitric acid treatment (NT), heat treatment (HT), and alkali treatment (AT), and their behaviors in vitro and in vivo was thoroughly studied by spectroscopic analysis. In vitro and in vivo results revealed that the rank of bioactivity of various surfaces was AE < NT < HT < AT. XPS analysis indicated that AT greatly increased the OH group concentration on the titanium surface whereas HT reduced the OH group concentration. Thus, OH group difference could not be a good explanation of bioactivity difference. On the other hand, ToF-SIMS analysis demonstrated the TiOH+/Ti+ ratios of various surfaces correlated well with the bioactivity and the surface energies, which implied that Ti-OH could play an important role in the bioactivity. This detail investigation of the relationship between surface functional groups and surface bioactivity could help us to broaden the knowledge about the mechanism of bioactivity and to design next generation bioactive materials.


Assuntos
Materiais Biocompatíveis/química , Substitutos Ósseos/química , Titânio/química , Algoritmos , Álcalis , Animais , Cristalização , Cães , Temperatura Alta , Humanos , Técnicas In Vitro , Espectrometria de Massas , Teste de Materiais , Microscopia de Fluorescência , Ácido Nítrico/química , Próteses e Implantes , Propriedades de Superfície , Difração de Raios X
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