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1.
Materials (Basel) ; 17(12)2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38930162

RESUMEN

Currently, large amounts of agricultural solid wastes have caused serious environmental problems. Agricultural solid waste is made into biochar by pyrolysis, which is an effective means of its disposal. As the prepared biochar has a good adsorption capacity, it is often used to treat pollutants in water, such as heavy metals and pharmaceuticals. PRO is an emerging contaminant in the environment today. However, there are limited studies on the interaction between biochars with PRO. Thus, in this study, we investigate the adsorption of PRO onto the biochars derived from three different feedstocks. The order of adsorption capacity was corn stalk biochar (CS, 10.97 mg/g) > apple wood biochar (AW, 10.09 mg/g) > rice husk biochar (RH, 8.78 mg/g). When 2 < pH < 9, the adsorption capacity of all the biochars increased as the pH increased, while the adsorption decreased when pH > 9, 10 and 10.33 for AW, CS and RH, respectively. The adsorption of PRO on biochars was reduced with increasing Na+ and Ca2+ concentrations from 0 to 200 mg·L-1. The effects of pH and coexisting ions illustrated that there exist electrostatic interaction and cation exchange in the process. In addition, when HA concentration was less than 20 mg/L, it promoted the adsorption of PRO on the biochars; however, when the concentration was more than 20 mg/L, its promoting effect was weakened and gradually changed into an inhibitory effect. The adsorption isotherm data of PRO by biochars were best fitted with the Freundlich model, indicating that the adsorption process is heterogeneous adsorption. The adsorption kinetics were fitted well with the pseudo-second-order model. All the results can provide new information into the adsorption behavior of PRO and the biochars in the aquatic environment and a theoretical basis for the large-scale application of biochar from agricultural solid wastes.

2.
ACS Appl Mater Interfaces ; 16(17): 21828-21837, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38639177

RESUMEN

Two-dimensional (2D) van der Waals materials are increasingly seen as potential catalysts due to their unique structures and unmatched properties. However, achieving precise synthesis of these remarkable materials and regulating their atomic and electronic structures at the most fundamental level to enhance their catalytic performance remain a significant challenge. In this study, we synthesized single-crystal bulk PtTe crystals via chemical vapor transport and subsequently produced atomically thin, large PtTe nanosheets (NSs) through electrochemical cathode intercalation. These NSs are characterized by a significant presence of Te vacancy pairs, leading to undercoordinated Pt atoms on their basal planes. Experimental and theoretical studies together reveal that Te vacancy pairs effectively optimize and enhance the electronic properties (such as charge distribution, density of states near the Fermi level, and d-band center) of the resultant undercoordinated Pt atoms. This optimization results in a significantly higher percentage of dangling O-H water, a decreased energy barrier for water dissociation, and an increased binding affinity of these Pt atoms to active hydrogen intermediates. Consequently, PtTe NSs featuring exposed and undercoordinated Pt atoms demonstrate outstanding electrocatalytic activity in hydrogen evolution reactions, significantly surpassing the performance of standard commercial Pt/C catalysts.

3.
Polymers (Basel) ; 14(1)2022 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-35012226

RESUMEN

Adsorption is an effective method to remove tetracycline (TC) from water, and developing efficient and environment-friendly adsorbents is an interesting topic. Herein, a series of novel phenyl porous organic polymers (P-POPs), synthesized by one-pot polymerization of different ratios of biphenyl and triphenylbenzene under AlCl3 catalysis in CH2Cl2, was studied as a highly efficient adsorbent to removal of TC in water. Notably, the obtained POPs possessed abundant phenyl-containing functional groups, large specific surface area (1098 m2/g) with abundant microporous structure, high pore volume (0.579 cm3/g), favoring the removal of TC molecules. The maximum adsorption capacity (fitted by the Sips model) could achieve 581 mg/g, and the adsorption equilibrium is completed quickly within 1 h while obtaining excellent removal efficiency (98%). The TC adsorption process obeyed pseudo-second-order kinetics and fitted the Sips adsorption model well. Moreover, the adsorption of POPs to TC exhibited a wide range of pH (2-10) adaptability and outstanding reusability, which could be reused at least 5 times without significant changes in structure and efficiency. These results lay a theoretical foundation for the application of porous organic polymer adsorbents in antibiotic wastewater treatment.

4.
Artículo en Inglés | MEDLINE | ID: mdl-34444130

RESUMEN

(1) Objectives: Using cross-sectional datasets, we investigated whether better self-perceived physical and social neighborhood environment was associated with perceived health status and health-related behaviors among Chinese rural residents. (2) Study Design: The study was based on the 2016 China Family Panel Studies (CFPS) survey. The sample consisted of 7191 rural residents over 18 in China. (3) Methods: The article measured physical neighborhood environment from the two aspects of dwelling environment (DE) and public facilities convenience (PFC), and social neighborhood environment from public security (PS) and neighborhood relationship (NR). Associations between health status/health-related behaviors and self-perceived physical/social neighborhood environment were analyzed using multivariable logistic regression models adjusted for socio-demographic characteristics. (4) Results: The results suggested that rural residents who live in a good neighborhood environment reported having a better health status. Specifically, rural residents who reported living in good DE were less likely to have a depressive mood and poor health conditions. Those who reported good PFC were less likely to have depressive mood, poor self-rated health and chronic diseases. Rural residents who reported having good PS were less likely to have a depressive mood. Those who reported good NR were less likely to have a depressive mood, poor self-rated health, chronic diseases and obesity. Regarding neighborhood environment and health-related behaviors, the results showed that rural residents who reported good PFC were more likely to do physical exercise. Notably, the regression results of the education level variable showed that education level significantly promoted the health-related behaviors (time sleeping weekday, physical exercise and smoking) of rural residents. (5) Conclusions: This article suggested that there was strong evidence for a relationship between physical and social neighborhood environment and the general health of rural residents due to all causes. According to the conclusion of this article, in order to improve the health of rural residents, policy interventions should give priority to improving the neighborhood environment. In addition, the improvement in the degree that rural residents are exposed to education is of the same importance, which helps more rural residents to maintain good health-related behaviors.


Asunto(s)
Características de la Residencia , Medio Social , China , Estudios Transversales , Estado de Salud , Humanos
5.
Artículo en Inglés | MEDLINE | ID: mdl-33946141

RESUMEN

The purpose of this study is to verify the influence of internet usage frequency on women's fertility intentions and to examine the mediating effects of gender role attitudes, under the influence of internet usage frequency that affects women's fertility intentions, combined with the specific Chinese cultural context. A cross-sectional secondary data analysis was conducted using a sample of 3113 women of childbearing age in the Chinese General Social Survey in 2017 (CGSS2017). The results of the negative binomial regression model showed that, under the premise of controlling individual characteristic variables, the higher the frequency of internet usage, the lower the fertility intention (p < 0.01). The results of the mediating effect model show that the more frequently women use the internet, the lower their fertility intentions, and the less they agree with Chinese traditional gender roles, which are "men work outside to support the family while women stay at home to take care of the family". These findings have implications in formulating public policies aimed at increasing the fertility rate; that is, it is not enough to increase women's fertility intentions under China's universal two-child policy. Moreover, public policy formulators need to consider gender role attitudes and the influence of the internet as a method for dissemination of information.


Asunto(s)
Rol de Género , Intención , Actitud , Niño , Estudios Transversales , Femenino , Fertilidad , Humanos , Uso de Internet , Masculino
6.
Sci Rep ; 10(1): 10259, 2020 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-32581369

RESUMEN

Carbon nanotubes could accumulate in organism and have a negative impact on the structure and function of the ecosystem when they were discharged into environment. Furthermore, it will affect the migration and fate of pollutants in the water body. The study is mainly to explore the adsorption behavior and mechanism of beta-blocker on multi-walled carbon nanotubes (MWCNTs). Propranolol (PRO) was selected as the representative of beta-blocker. The effects of different environmental factors such as pH, ionic strength and humic acid (HA) on the adsorption process were investigated. The adsorption results were characterized by Zeta potential. At the same time, the effects of different types of drugs on the adsorption process were explored and the possible adsorption mechanisms were analyzed. The experimental results showed that the adsorption behavior was significantly different under different pH conditions. π-π EDA interaction, hydrophobic interaction and hydrogen bonding were speculated to be the main adsorption mechanisms for PRO adsorption on MWCNTs.

7.
Artículo en Inglés | MEDLINE | ID: mdl-32384759

RESUMEN

Son preference has been shown to influence the childbearing behavior of women, especially in China. Existing research has largely focused on this issue using cross-sectional data of urban or rural populations in China, while evidence from the rural-urban migrant women is relatively limited. Based on the data of China Migrants Dynamic Survey in 2015, we used logistic regression models to explore the relationship of son preference and reproductive behavior of rural-urban migrant women in China. The results show that the son preference of migrant women is still strong, which leads women with only daughters to have significantly higher possibility of having another child and results in a higher imbalance in the sex ratio with higher parity. Migrant women giving birth to a son is a protective factor against having a second child compared to women whose first child was a girl. Similarly, the effects of the gender of the previous child on women's progression from having two to three children showed the same result that is consistent with a preference for sons. These findings have implications for future public strategies to mitigate the son preference among migrant women and the imbalance in the sex ratio at birth.


Asunto(s)
Composición Familiar , Conducta Reproductiva , Población Rural , Migrantes/estadística & datos numéricos , Niño , China , Estudios Transversales , Femenino , Fertilidad , Humanos , Masculino , Núcleo Familiar , Embarazo , Población Urbana
8.
Opt Express ; 28(4): 5288-5305, 2020 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-32121753

RESUMEN

We theoretically investigate the optomechanically induced transparency (OMIT) phenomenon in a hybrid optomechanical system composing of an optomechanical cavity and a traditional one. A Kerr medium is inserted in the optomechanical cavity and the other traps the atomic ensemble. We demonstrate the appearance of electromagnetically and optomechanically induced transparency when there is only Kerr medium or atoms in the system. We give an explicit explanation for the mechanism of the transparency. Moreover, we set up new scheme for the measurement of Kerr coefficient and the single atom-photon coupling strength. It is shown that Kerr nonlinearity can inhibit the normal mode splitting (NMS) when the tunnel strength is strong coupling. Furthermore, in the output field, slow light and fast light are converted to realize the tunable switch from slow light to fast light. This study has some important guiding significance in the fields of the high precision measurement and quantum information processing.

9.
Materials (Basel) ; 12(20)2019 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-31614425

RESUMEN

The efficient and green removal of residual antibiotics in the environment is an attractive topic. In this work, four different phenyl porous organic polymers (P-POPs) photocatalysts were successfully synthesized, and a series of techniques, such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption and desorption experimentation, and solid ultraviolet visible spectroscopy (UV-vis) were conducted to characterize the obtained P-POPs. Moreover, the photocatalytic property of P-POPs in the removal of tetracycline was studied, and the reaction conditions were optimized. Further study indicated that the P-POPs were also efficient for removing other antibiotics, such as chloramphenicol, in a high removal rate of 77%. Furthermore, the separation of the photocatalysts from the solution was easy, and the photocatalysts could be reused at least four times without a considerable loss in catalytic activity.

10.
Nanomaterials (Basel) ; 9(10)2019 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-31600918

RESUMEN

As a nano-adsorbent, magnetic graphene oxide (GO/Fe3O4) was synthesized to potentially adsorb propranolol (PRO) from water. The synthetic material was characterized by SEM, TEM, VSM, FTIR, XRD, zeta potential, and XPS. The environmental factors, such as pH, humic acid concentration, PRO concentration, and contact time, were investigated regarding their effect on the adsorption process. The kinetics data fitted the pseudo first-order and second-order kinetics equations. The Langmuir equation, the Freundlich equation, and the Sips equation were used to analyze the adsorption isotherms. Electrostatic attraction, hydrogen bonding, and the π-π interaction all contributed to the adsorption process of PRO onto GO/Fe3O4. The discovery of this study emphasized the feasibility of GO/Fe3O4 removal of PRO and expanded the scope of the application of GO.

11.
Materials (Basel) ; 12(6)2019 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-30897739

RESUMEN

In this work, a novel adsorbent attapulgite/graphene oxide magnetic composite (ATP/Fe3O4/GO) was synthesized for removing propranolol (PRO) from aqueous water. The factors affecting the PRO adsorption process onto ATP/Fe3O4/GO including pH, ionic strength, sorbent dosage, and humic acid were systematically investigated by batch experiments. Meanwhile, magnetic attapulgite (ATP/Fe3O4) and magnetic graphene oxide (GO/Fe3O4) were prepared for the comparison of the adsorption performance for PRO. The structural and surface characteristics of the resulting materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential measurements, and scanning electron microscope. The results showed that the adsorption rate of PRO onto ATP/Fe3O4/GO was up to 99%, faster and higher than that of other adsorbents involved at neutral pH. Moreover, the adsorption kinetics were better fitted with pseudo-first-order kinetic model than the second-order kinetic model. The adsorption data were fitted well with the Freundlich isotherm equations, implying that the adsorption process was heterogeneous. The adsorption reaction was endothermic and spontaneous according to the thermodynamic parameters. All results indicated that ATP/Fe3O4/GO was a promising adsorbent for removing PRO from water.

12.
Sci Rep ; 8(1): 12638, 2018 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-30139973

RESUMEN

In this work, we study the dynamic robustness of an endoreversible Carnot cycle working at the maximum per-unit-time performance regime, based on the linearization technique for dynamical systems and the local stability analysis. Our analysis is focused on the endoreversible Carnot refrigerator model, which works in the maximum per-unit-time coefficient of performance. At the steady-state of the maximum performance, the expressions of the relaxation times describing the stability of the system are derived. It is found that the relaxation times in the cycle condition are the function of thermal conductances σh and σc, the temperatures of the heat reservoirs Th and Tc, and the heat capacity C. The influence of the temperature ratio τ = Tc/Th and the thermal conductance ratio σr = σh/σc on the relaxation times is discussed in detail. The results obtained here are useful and provide a potential guidance for the design of an endoreversible Carnot refrigerator working in the maximum performance per cycle time optimization condition.

13.
J Hazard Mater ; 344: 333-342, 2018 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-29080486

RESUMEN

Critical water system used for decomposition and debromination of waste printed circuit board (PCBs) has two disadvantages: low value-added oil phase products and halfway debromination at low temperature condition. In this study, critical water-alcohol composite medium was found to be a promising method to surmount these disadvantages. Critical water-ethanol (CWE) and critical water-methanol (CWM) were selected as the composite medium. The temperature of CWE and CWM had a significant effect on the oil phase composition. At low temperature CWE/CWM of 300°C, 4-(1-methylethyl)-phenol with high concentration could be recovered. CWM of 400°C was beneficial to the generation of ether compounds and high level of anisole could be obtained, while 450°C was beneficial to the generation of high level of multi-alkyl substituted phenol derivatives or benzene derivatives such as p-xylene. Br-free oil phase products could be obtained when the temperature of CWE/CWM ≥300°C. Different oil phase products with high level of chemicals or chemical intermediates could be obtained by controlling the reaction conditions of CWE/CWM. It is believed that the additional value of the oil phase products derived from waste PCBs can be greatly improved by this new process.

14.
Sci Rep ; 7(1): 17258, 2017 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-29222484

RESUMEN

We investigate dynamical properties and the ground-state cooling of a mechanical oscillator in an optomechanical system coupling with an atomic ensemble. In this hybrid optomechanical system, an atomic ensemble which consists of two-level atoms couples with the cavity field. Here we consider the case where the atomic ensemble is in higher excitation. Studies show that the atom-field coupling strength can obviously influence the cooling process, and we can achieve the ground-state cooling of the mechanical oscillator by choosing the appropriate physical parameters of the system. Our cooling mechanism has potential applications in quantum information processing and procession measurement.

15.
Sci Rep ; 6: 35090, 2016 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-27725763

RESUMEN

We investigate theoretically the optical response of the output field and the tunable slow and fast light in a nonlinear optomechanical cavity with a degenerate optical parametric amplifier (OPA) and a higher order excited atomic ensemble. Studies show that the higher-order-excitation atom which is similar to the degenerate OPA that acts as a nonlinear medium, induces an additional dip in absorption spectrum of the probe field. The coherence of the mechanical oscillator leads to split the peak in absorption in the probe field spectrum so that the phenomenon of optomechanically induced transparency (OMIT) is generated from the output probe field. In particular, the presence of nonlinearities with the degenerate OPA and the higher order excited atoms can affect significantly the width of the transparency windows, providing an additional flexibility for controlling optical properties. Furthermore, in the presence of the degenerate OPA, the optical-response properties for the probe field become phase-sensitive so that a tunable switch from slow to fast light can be realized.

16.
Opt Express ; 23(24): 30970-84, 2015 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-26698728

RESUMEN

We design a hybrid optomechanical setup, in which an ensemble of quantum emitters is coupled with a movable mirror through vacuum interaction. The optical cavity is driven along with the quantum emitters and therefore the coupling between the cavity field and the ensemble determines the dynamics of the coupled system. In particular, we investigated the influence of the vacuum coupling strength on the effective frequency and the effective damping rate of the movable mirror, which shows that the vacuum interaction enhances greatly the effective damping rate. Further, the cooling characteristics of the mechanical resonator is analyzed in detail by counting the effective phonon number in the mirror's motion. It is found that the ground-state cooling of the mechanical motion can be approached in the bad cavity limit when the vacuum coupling is included. The dependence of the cooling of the mechanical motion on the parameters of the cavity and the quantum emitter is investigated in detail numerically.

17.
Sheng Li Xue Bao ; 66(2): 186-94, 2014 Apr 25.
Artículo en Chino | MEDLINE | ID: mdl-24777409

RESUMEN

The major objective was to explore the effect of early hyperbaric oxygen (HBO) therapy on the tissue structure, apoptosis, and metalloproteinases of kidney cells in Goto-Kakizaki (GK) rats with type 2 diabetes mellitus. GK rats (n = 24) were divided randomly and evenly into model, metformin hydrochloride (MH), and hyperbaric oxygen (HBO) groups, while healthy Wistar rats (n = 8) were used as normal control group. The healthy rats in the normal control group and the GK rats in the model group were both intragastrically administered with purified water (5 mL/kg) once per day. Meanwhile, the rats in the MH group received intragastric administration of MH (250 mg/kg) once daily, while the rats in the HBO group inhaled pure oxygen under a constant pressure (0.15 MPa) for 30 min. After 3 weeks of treatment, the body weight of each rat was measured, and the blood samples were collected from tails. Subsequently, the kidneys of all rats were excised for weighing mass and further examination. For each renal sample, the sections were firstly embedded with paraffin and sliced to prepare histopathologic sections stained using HE, PAS and Masson, respectively, for subsequent observation with optical microscopy. Later, the apoptosis of kidney cells was examined using the TUNEL method by computing the apoptotic index. Furthermore, the histopathologic sections were also examined using the immunohistochemistry approach with Caspase-3, MMP-2, and TIMP-2 antibodies, respectively. At the same time, the plasma concentration of TGF-ß1 of the rats in each group was detected using ELISA method. These resultant data showed that the pathological changes of the HBO group were less than those of the model group with respect to increased glomerular volume density of mesangial cells, broadening mesangial matrix and thickening basement membrane as well as swelling renal tubular epithelial cells. The index of cell apoptosis and Caspase-3 expression in the HBO group showed no significant differences (P > 0.05) compared with those in the normal control and MH groups respectively, but demonstrated significant decrease compared with that in the model group (P < 0.01). Meanwhile, the MMP-2 and TIMP-2 expressions of the HBO group were stronger than those in the model and MH groups, but weaker than those in the normal control group (P < 0.05). Although the plasma concentration of TGF-ß1 in HBO, MH and model groups was greater than that in the normal control group, no significant statistical difference was distinguished among these four groups (P > 0.05). These results indicate that the HBO treatment can inhibit the apoptosis and Caspase-3 expression of renal cells of GK rats, adjust the activity of MMP-2 and its inhibitors, and reduce the accumulation of extracellular matrix. This implies that the HBO treatment might protect renal tissues, thus delaying occurrence and retaining development of diabetic nephropathy.


Asunto(s)
Apoptosis , Diabetes Mellitus Experimental/fisiopatología , Oxigenoterapia Hiperbárica , Riñón/citología , Animales , Caspasa 3/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Nefropatías Diabéticas/terapia , Metaloproteinasa 2 de la Matriz/metabolismo , Oxígeno/administración & dosificación , Ratas , Ratas Wistar , Inhibidor Tisular de Metaloproteinasa-2/metabolismo , Factor de Crecimiento Transformador beta1
18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 86(1 Pt 1): 011110, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23005371

RESUMEN

We study a fluctuation-driven ratchet-oscillator system that consists of two ratchet pinions in contact with thermal baths at different temperatures. Coupling between noncontact parts of the system is mediated by the Casimir force through a thin corrugated plate. Due to mutual rectification, the two ratchets achieve directed average motion in opposite directions. We numerically probe the average velocity, the Peclet number, and the thermal efficiency of the system as functions of the effective temperatures of the thermal baths and other important dimensionless control parameters. It is found that optimal parameter values exist which maximize the directed transport rate but with very low efficiency. We expect that the obtained results will help in the design of noncontact mechanical devices in the future.


Asunto(s)
Transferencia de Energía , Modelos Teóricos , Oscilometría/instrumentación , Simulación por Computador , Calor , Movimiento (Física)
19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 82(4 Pt 1): 041130, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21230261

RESUMEN

We study a Feynman-like thermal Brownian motor, in which the asymmetric corrugated cylinder as the ratchet is coupled with a corrugated plate by the noncontact Casimir interaction between them. The source of driving of the system is the thermal fluctuations and its dynamic evolution is described by a set of Langevin equations. Further, the mean velocity and thermal efficiency of the motor in the overdamped limit are studied in detail as a function of the temperature of the baths, external load applied, magnitude of the Casimir interaction, and other relevant parameters by the numerical stimulation. The transport properties attained here and the essential roles of the Casimir interaction can be explicitly demonstrated by designing a Casimir Brownian motor with present nanotechnology.


Asunto(s)
Modelos Teóricos , Movimiento (Física) , Temperatura , Cinética
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