Methane contributes to global warming,and livestock is one of the sources of methane production.However,methane emission studies using bibliometric tools in livestock are lacking.Given the negative impact of climate c...Methane contributes to global warming,and livestock is one of the sources of methane production.However,methane emission studies using bibliometric tools in livestock are lacking.Given the negative impact of climate change on the ecosystem and the rise in methane emissions,it is essential to conduct a bibliometrics study to provide an overview and research trends.We used the Bibliometrix package and VOSviewer to decipher bibliometric indices for methane emissions in cattle farms(MECF).Current dataset were collected from the Web of Science(Core Collection)database,and 8,998 publications were analyzed.The most co-occurring keywords scientists preferred were methane(1,528),greenhouse gas(443),methane emissions(440),and cattle(369).Methane was the most frequently used keyword in the published scientific literature.Thematic evolution of research themes and trend results highlighted carbon dioxide,methane,dairy cattle,cattle,and risk factors during 1999–2017.Chinese Academy of Sciences ranked on top with 485 publications,followed by Agriculture&Agri-Food Canada,University of Colorado,National Oceanic and Atmospheric Administration,and Aarhus University.Chinese Academy of Sciences was also the most cited organization,followed by the University of Colorado,Agriculture&Agri-Food Canada,National Oceanic and Atmospheric Administration,and United States Geological Survey.Source analysis showed that the Science of the Total Environment was cited with the highest total link strength.Science of the Total Environment ranked first in source core 1 with 290 citation frequencies,followed by Journal of Dairy Science with 223 citation frequencies.Currently,no bibliometric study has been conducted on MECF,and to fill this knowledge gap,we carried out this study to highlight methane emissions in cattle farms,aiming at a climate change perspective.In this regard,we focused on the research productivity of countries authors,journals and institutions,co-occurrence of keywords,evolution of research trends,and collaborative networking.Based on relevance degree of centrality,methane emissions and greenhouse gases appeared as basic themes,cattle,and dairy cattle appeared as emerging/declining themes,whereas,methane,greenhouse gas and nitrous oxide appeared to fall amongst basic and motor themes.On the other hand,beef cattle,rumen and dairy cow seem to be between motor and niche themes,and risk factors lie in niche themes.The present bibliometric analysis provides research progress on methane emissions in cattle farms.Current findings may provide a framework for understanding research trends and themes in MECF research.展开更多
Acidic-and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes.Elevating tempe...Acidic-and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes.Elevating temperature can accelerate hydrolytic kinetics and improve efficiency.In this work,magnetic sulfonated polypropylene resin(Fe_(3)O_(4)@PS-S)composites were reported for acidic-thermal hydrolysis of tylosin by employing the acidic feature of sulfonic group,the dielectric effect of resin,and the magnetic-loss effect of magnetite under microwave irradiation.As observed,a rapid and complete mitigation 100 mg/L of tylosin was achieved within 15 min by the catalysts.Acidic cleavage of tylosin was fulfilled by sulfonic groups in the composites,and microwave thermal accelerated the hydrolysis reactions due to the dielectric and magnetic-loss effects.Differentiating the dielectric and magnetic-loss effects through electromagnetic analyses indicated that the latter contributed more in converting microwave energy to heat.The interactions under multiple operational conditions were quantitatively fitted using the Behnajady model and visually demonstrated,which indicated that a synergic effect of microwave thermal-and acidichydrolyses contributed to the efficient mitigation of tylosin.The transformation products were identified and the pathways were supposed.Cleaving deoxyaminosugars groups and destructing lactone structures led to reduced antibacterial potential and toxicity reduction.The acute toxicity of tylosin and transformation products to fish,daphnia,and green algae were all classified as non-toxic.This work suggested that this synergistic acid-thermal hydrolytic method is attractive and promising in pretreating tylosin production wastewater in field.展开更多
The present study reports large room-temperature ferromagnetism in Co and Tb co-doped GaN films and further investigates the correlation between the doping concentration and the magnetic moment.X-ray photoelectron spe...The present study reports large room-temperature ferromagnetism in Co and Tb co-doped GaN films and further investigates the correlation between the doping concentration and the magnetic moment.X-ray photoelectron spectroscopy(XPS)and X-ray diffraction(XRD)measurements confirm that most of the dopants are incorporated into the GaN lattice.Photoluminescence(PL)and Raman spectra results reveal that post-annealing repaired most of lattice defects induced by ion implantation.The ZFC/FC curves show a blocked phase related to Co precipitates in Co single-doped GaN system and this phase is suppressed by the incorporation of Tb ions in the co-doped GaN systems.Although the magnetic properties were enhanced with the co-implantation of Co and Tb ions,the magnetic moment introduced by each ion slightly decreased with increasing Tb concentration.Density functional theory(DFT)calculations suggest that a high doping concentration of Tb atoms leads to the antiferromagnetic phase in the nearest position between Co and Tb ions.Appropriate co-doping with Co and Tb ions in GaN favors the development of enhanced ferromagnetism with no secondary phase.Our study not only offers valuable insights for understanding the magnetic characteristics of co-doped GaN,but also highlights the viability of developing room-temperature diluted magnetic semiconductors by appropriately co-doping TM and RE elements.展开更多
Fibroblast activation protein(FAP)is overexpressed in cancer-associated fibroblasts across various cancer types.Numerous radiolabeled FAP inhibitors(FAPIs)(Fig.S1A)currently under clinical investigation have shown rem...Fibroblast activation protein(FAP)is overexpressed in cancer-associated fibroblasts across various cancer types.Numerous radiolabeled FAP inhibitors(FAPIs)(Fig.S1A)currently under clinical investigation have shown remarkable potential in cancer theranostics.展开更多
Medicinal and edible plants(MEPs)have attracted increasing interest worldwide due to their natural origin,reliable efficacy,and minimal side effects in recent years.However,the complex and fluctuating levels of inhere...Medicinal and edible plants(MEPs)have attracted increasing interest worldwide due to their natural origin,reliable efficacy,and minimal side effects in recent years.However,the complex and fluctuating levels of inherent chemical constituents and exogenous hazardous contaminants have triggered widespread concerns about their efficacy and safety.Developing analytical methods for both active components and exogenous contaminants concealed in these samples is central to the quality evaluation,in which sample preparation is crucial.This paper systematically reviewed the evolution of standard sample preparation methods,microextraction techniques based on novel solvents and nanomaterials,and innovative integrated techniques from 2019.Accordingly,their merits and weaknesses were discussed by showing fruitful applications in identifying and quantifying active components in these plants.Further,successful applications for analyzing exogenous contaminants were prominently showcased,highlighting the management of pesticides,heavy metals,mycotoxins,and polycyclic aromatic hydrocarbons(PAHs).Finally,forthcoming trends in sample preparation techniques were delineated to illuminate the development and implementation of more advanced sample preparation technologies.展开更多
Background:The Teaching Personal and Social Responsibility(TPSR)model in physical education(PE)has been shown to promote Social and emotional competence(SEC).However,the underlying mechanisms through which TPSR enhanc...Background:The Teaching Personal and Social Responsibility(TPSR)model in physical education(PE)has been shown to promote Social and emotional competence(SEC).However,the underlying mechanisms through which TPSR enhances SEC,particularly in university students within the Chinese context,remain unclear.This study aims to explore the effects of TPSR and the mediating roles of self-efficacy and grit in improving SEC.Methods:71 Chinese university students were in the TPSR group,and 39 in the Traditional Teaching Model(TTM)control group,assessed before and after a 14-week intervention.The Adapted Social and Emotional Competence Scale(ASECS),General Self-Efficacy Scale(GSES),and Short Grit Scale(SGS)were used for measurement.A mixed-design ANOVA assessed TPSR’s effects,with post-hoc t-tests for pre-post differences and mediation analysis for underlying mechanisms.Results:The mixed-design ANOVA revealed a significant interaction between time and intervention on SEC.The TPSR group showed significant improvement from pre-test to post-test(t(70)=−2.63,p=0.011,Cohen’s d=−0.31),whereas the TTM control group did not(t(38)=1.40,p=0.170,Cohen’s d=0.22).The TPSR group also showed a significant increase in self-efficacy(t(70)=−3.67,p<0.001,Cohen’s d=−0.44),while no change was observed in the TTM group(t(38)=0.62,p=0.540,Cohen’s d=0.10).No significant effects were found for grit(F=0.342,p=0.560).Mediation analysis confirmed that self-efficacy significantly mediated the effects of the TPSR intervention on SEC(95%CI:0.0277 to 0.2897).Conclusion:The TPSR intervention led to significant improvements in university students’SEC and self-efficacy,with no significant changes observed in grit.Self-efficacy served as a mediator in the relationship between the intervention and SEC.展开更多
This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 b...This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 batches of market samples in China.The samples were extracted with acetonitrile,cleaned up with primary secondary amine(PSA)and octadecylsilane(C18)and determined by GC-MS/MS in multiple reaction monitoring(MRM)mode.Matrix-matched calibration was recommended to combat the matrix effect.A good linearity was observed in the range of 10−500 ng/mL with correlation coefficients≥0.9950.The mean recoveries for most of the pesticides were in the range of 70%−120%with RSD<20%.The limits of detection ranged 0.28–2.00μg/kg,while the limits of quantification were 0.94–6.65μg/kg.Following the application of“top-down”approach,the expanded measurement uncertainty for all the analytes was<30%.The proposed method was successfully applied to determine pesticide residues in 20 market samples in China,where 9 pesticides were detected and quintozene exceeded the criteria domestically and abroad.展开更多
The degradation of metoprolol(MTP)by the UV/sulfite with oxygen as an advanced reduction process(ARP)and that without oxygen as an advanced oxidation process(AOP)was comparatively studied herein.The degradation of MTP...The degradation of metoprolol(MTP)by the UV/sulfite with oxygen as an advanced reduction process(ARP)and that without oxygen as an advanced oxidation process(AOP)was comparatively studied herein.The degradation of MTP by both processes followed the first-order rate law with comparable reaction rate constants of 1.50×10^(-3)sec^(−1)and 1.20×10^(-3)sec^(−1),respectively.Scavenging experiments demonstrated that both e^(−)_(aq)and H·played a crucial role in MTP degradation by the UV/sulfite as an ARP,while SO_(4)^(·−)was the dominant oxidant in the UV/sulfite AOP.The degradation kinetics of MTP by the UV/sulfite as an ARP and AOP shared a similar pH dependence with a minimum rate obtained around pH 8.The results could be well explained by the pH impacts on the MTP speciation and sulfite species.Totally six transformation products(TPs)were identified from MTP degradation by the UV/sulfite ARP,and two additional ones were detected in the UV/sulfite AOP.The benzene ring and ether groups of MTP were proposed as the major reactive sites for both processes based on molecular orbital calculations by density functional theory(DFT).The similar degradation products of MTP by the UV/sulfite process as an ARP and AOP indicated that e^(−)_(aq)/H·and SO_(4)^(·−)might share similar reaction mechanisms,primarily including hydroxylation,dealkylation,and H abstraction.The toxicity of MTP solution treated by the UV/sulfite AOP was calculated to be higher than that in the ARP by the Ecological Struc-ture Activity Relationships(ECOSAR)software,due to the accumulation of TPs with higher toxicity.展开更多
Dear Editor,Neuromodulation,a rapidly expanding field attracting wide attention over recent decades,facilitates human cognition,behavior,and pathology by modifying the activity of specific neural targets.Human brain f...Dear Editor,Neuromodulation,a rapidly expanding field attracting wide attention over recent decades,facilitates human cognition,behavior,and pathology by modifying the activity of specific neural targets.Human brain functions can be modified by exogenous brain neuromodulation techniques that deliver physical energy(e.g.,electrical current or magnetic pulses)into the brain[1],such as deep brain stimulation,transcranial magnetic stimulation,and tran-scranial direct current stimulation.展开更多
We propose a novel rumor propagation model with guidance mechanism in hetero geneous complex networks.Firstly,the sharp threshold of rumor propagation,global stability of the information-equilibrium and information-pr...We propose a novel rumor propagation model with guidance mechanism in hetero geneous complex networks.Firstly,the sharp threshold of rumor propagation,global stability of the information-equilibrium and information-prevailingequilibrium under R_(0)<1 and R_(0)>1 is carried out by Lyapunov method and LaSalle's invariant principle.Next,we design an aperiodically intermittent stochastic stabilization method to suppress the rumor propagation.By using the Ito formula and exponential martingale inequality,the expression of the minimum control intensity is calculated.This method can effectively stabilize the rumor propagation by choosing a suitable perturb intensity and a perturb time ratio,while minimizing the control cost.Finally,numerical examples are given to illustrate the analysis and method of the paper.展开更多
As the major and abundant type of glucosinolates(GL)in plants,sinigrin has potential functions in promoting health and insect defense.The final step in the biosynthesis of sinigrin core structure is highly representat...As the major and abundant type of glucosinolates(GL)in plants,sinigrin has potential functions in promoting health and insect defense.The final step in the biosynthesis of sinigrin core structure is highly representative in GL compounds,which corresponds to the process from 3-methylthiopropyl ds-GL to 3-methylthiopropyl GL catalyzed by sulfotransferase(SOT).However,due to the lack of the crystallographic structure of SOT complexed with the 3-methylthiopropyl GL,little is known about this sulfonation process.Fortunately,the crystal structure of SOT 18 from Arabidopsis thaliana(At SOT18)containing the substance(sinigrin)similar to 3-methylthiopropyl GL has been determined.To understand the enzymatic mechanism,we employed molecular dynamics(MD)simulation and quantum mechanics combined with molecular mechanics(QM/MM)methods to study the conversion from ds-sinigrin to sinigrin catalyzed by AtSOT18.The calculated results demonstrate that the reaction occurs through a concerted dissociative mechanism.Moreover,Lys93,Thr96,Thr97,Tyr130,His155,and two enzyme peptide chains(Pro92-Lys93 and Gln95-Thr96-Thr97)play a role in positioning the substrates and promoting the catalytic reaction by stabilizing the transition state geometry.Particularly,His155 acts as a catalytic base while Lys93 acts as a catalytic acid in the reaction process.The presently proposed concerted dissociative mechanism explains the role of At SOT18 in sinigrin biosynthesis,and could be instructive for the study of GL biosynthesis catalyzed by other SOTs.展开更多
In this paper,a new bevel-tip flexible needle path planning method based on the bee-foraging learning particle swarm optimization(BFL-PSO)algorithm and the needle retraction strategy in 3D space is proposed to improve...In this paper,a new bevel-tip flexible needle path planning method based on the bee-foraging learning particle swarm optimization(BFL-PSO)algorithm and the needle retraction strategy in 3D space is proposed to improve the puncture accuracy and shorten the puncture distance in the case of multiple puncture targets.First,the movement of the needle after penetrating the human body is analyzed,and the objective function which includes puncture path error,puncture path length,and collision function is established.Then,the BFL-PSO algorithm and the needle retraction strategy are analyzed.Finally,medical images of the tissue to be punctured are obtained by medical imaging instruments,i.e.,magnetic resonance(MR),and the 3D model of the punctured environment is constructed by 3D Slicer to obtain the environment information on targets and obstacles,and the path of flexible needle is carried out based on the BFL-PSO optimization algorithm and the needle retraction strategy.The simulation results show that,compared with other path planning methods in the related literature,the new path planning method proposed in this paper has higher path planning accuracy,shorter puncture distance,and good adaptability to multi-target path planning problems.展开更多
In Li and Ren(Int.J.Numer.Methods Fluids 70:742–763,2012),a high-order k-exact WENO finite volume scheme based on secondary reconstructions was proposed to solve the two-dimensional time-dependent Euler equations in ...In Li and Ren(Int.J.Numer.Methods Fluids 70:742–763,2012),a high-order k-exact WENO finite volume scheme based on secondary reconstructions was proposed to solve the two-dimensional time-dependent Euler equations in a polygonal domain,in which the high-order numerical accuracy and the oscillations-free property can be achieved.In this paper,the method is extended to solve steady state problems imposed in a curved physical domain.The numerical framework consists of a Newton type finite volume method to linearize the nonlinear governing equations,and a geometrical multigrid method to solve the derived linear system.To achieve high-order non-oscillatory numerical solutions,the classical k-exact reconstruction with k=3 and the efficient secondary reconstructions are used to perform the WENO reconstruction for the conservative variables.The non-uniform rational B-splines(NURBS)curve is used to provide an exact or a high-order representation of the curved wall boundary.Furthermore,an enlarged reconstruction patch is constructed for every element of mesh to significantly improve the convergence to steady state.A variety of numerical examples are presented to show the effectiveness and robustness of the proposed method.展开更多
The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanis...The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(<33 L/s in Case 4) is employed, the cuttings bed completely blocks the borehole near the step surface and causes a stuck pipe directly. If the flow rate increases to the “low flow rate” interval(33-35 L/s in Case 4), a smaller flow rate instead facilitates borehole cleaning. If the flow rate is large enough to be in the “high flow rate” interval(>35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than those of other tripping velocities. As long as the applied tripping velocity is not within the “dangerous velocity”(0.4-0.5 m/s in Case 5) interval in the backreaming operation, the risk of the stuck pipe can be controlled validly. Finally, through the factors analyses of the annular geometry,particle properties, and fluid properties in Section 5, it can be found that the “low flow rate”, “high flow rate” and “dangers flow rate” tend to decrease and the “dangerous velocity” tends to increase with the conditions more favorable for hole cleaning. This study has some guiding significance for risk prediction and parameter setting of the backreaming operation.展开更多
This paper presents a robust filter called the quaternion Hardy filter(QHF)for color image edge detection.The QHF can be capable of color edge feature enhancement and noise resistance.QHF can be used flexibly by selec...This paper presents a robust filter called the quaternion Hardy filter(QHF)for color image edge detection.The QHF can be capable of color edge feature enhancement and noise resistance.QHF can be used flexibly by selecting suitable parameters to handle different levels of noise.In particular,the quaternion analytic signal,which is an effective tool in color image processing,can also be produced by quaternion Hardy filtering with specific parameters.Based on the QHF and the improved Di Zenzo gradient operator,a novel color edge detection algorithm is proposed;importantly,it can be efficiently implemented by using the fast discrete quaternion Fourier transform technique.From the experimental results,we conclude that the minimum PSNR improvement rate is 2.3%and the minimum SSIM improvement rate is 30.2%on the CSEE database.The experiments demonstrate that the proposed algorithm outperforms several widely used algorithms.展开更多
Photocatalysis using the abundant solar energy is an environmentally friendly and efficient way to degrade organic matter.Covalent triazine frameworks(CTFs),a new class of metal-free organic semiconductors responsive ...Photocatalysis using the abundant solar energy is an environmentally friendly and efficient way to degrade organic matter.Covalent triazine frameworks(CTFs),a new class of metal-free organic semiconductors responsive to visible light,are promising materials for water treatment.In this study,an original CTF,namely CTF-1,was modified by S-doping to form CTFSx,which were used as metal-free catalysts for degradation of methyl orange(MO)and bisphenol A(BPA).The outcomes demonstrated that the photocatalytic degradation of MO and BPA by CTFSxwas superior to that by CTF-1,with better stability and reusability.Within 6 h,53.2%MO and 84.7%BPA were degraded by CTFS5,and the degradation rate constants were 0.145 h-1and 0.29 h-1,respectively,which were 3.6 and 5.8 times higher than those of CTF-1.Further investigation revealed that enhanced visible light absorption,a reduced degree of free carrier recombination,rapid separation and transfer of photogenerated electrons and holes,and improved·OH oxidation capacity were important factors contributing to the significantly enhanced photocatalytic activity.The S-doping method effectively improved the light absorption performance,electronic structure,and modulation band structure of CTF-1.This work highlights the potential application of low-cost metal-free catalysts driven by visible light for the removal of organic pollutants from wastewater.展开更多
Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,ins...Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,instead of the traditional single-mode approximation method in the relativistic setting.We find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of acceleration.Meanwhile,our results also reveal the interesting behavior of the Gaussian steering asymmetry,which increases for a specific range of accelerated parameter and then gradually approaches to a finite value.Such finding is well consistent and explained by the well-known Unruh effect,which could significantly destroy the one-side Gaussian quantum steering.Finally,our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites,since the effects of acceleration are equal to the effects of gravity according to the equivalence principle.展开更多
In semiconductor photocatalysts,the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment.To solve the serious problem of electron−hole pair rec...In semiconductor photocatalysts,the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment.To solve the serious problem of electron−hole pair recombination in perylene diimide(PDI)organic semiconductors,we loaded ferric hydroxyl oxide(FeOOH)on PDI materials,successfully prepared novel FeOOH@PDI photocatalytic materials,and constructed a photo-Fenton system.The system was able to achieve highly efficient degradation of BPA under visible light,with a degradation rate of 0.112 min^(−1)that was 20 times higher than the PDI system,and it also showed universal degradation performances for a variety of emerging organic pollutants and anti-interference ability.The mechanism research revealed that the FeOOH has the electron trapping property,which can capture the photogenerated electrons on the surface of PDI,effectively reducing the compounding rate of photogenerated carriers of PDI and accelerating the iron cycling and H2O2 activation on the surface of FeOOH at the same time.This work provides new insights and methods for solving the problem of easy recombination of carriers in semiconductor photocatalysts and degrading emerging organic pollutants.展开更多
In this article,we study the initial boundary value problem of the two-dimensional nonhomogeneous incompressible primitive equations and obtain the local existence and uniqueness of strong solutions.The initial vacuum...In this article,we study the initial boundary value problem of the two-dimensional nonhomogeneous incompressible primitive equations and obtain the local existence and uniqueness of strong solutions.The initial vacuum is allowed.展开更多
Developing low-cost,efficient,and stable photocatalysts is one of the most promising methods for large-scale solar water splitting.As a metal-free semiconductor material with suitable band gap,graphitic carbon nitride...Developing low-cost,efficient,and stable photocatalysts is one of the most promising methods for large-scale solar water splitting.As a metal-free semiconductor material with suitable band gap,graphitic carbon nitride(g-C_(3)N_(4))has attracted attention in the field of photocatalysis,which is mainly attributed to its fascinating physicochemical and photoelectronic properties.However,several inherent limitations and shortcomings—involving high recombination rate of photocarriers,insufficient reaction kinetics,and optical absorption—impede the practical applicability of g-C_(3)N_(4).As an effective strategy,vacancy defect engineering has been widely used for breaking through the current limitations,considering its ability to optimize the electronic structure and surface morphology of g-C_(3)N_(4) to obtain the desired photocatalytic activity.This review summarizes the recent progress of vacancy defect engineered g-C_(3)N_(4) for solar water splitting.The fundamentals of solar water splitting with g-C_(3)N_(4) are discussed first.We then focus on the fabrication strategies and effect of vacancy generated in g-C_(3)N_(4).The advances of vacancy-modified g-C_(3)N_(4) photocatalysts toward solar water splitting are discussed next.Finally,the current challenges and future opportunities of vacancy-modified g-C_(3)N_(4) are summarized.This review aims to provide a theoretical basis and guidance for future research on the design and development of highly efficient defective g-C_(3)N_(4).展开更多
基金supported by the Special Fund for Science and Technology Innovation Strategy of Guangdong Province,China(2022660500250009604)。
文摘Methane contributes to global warming,and livestock is one of the sources of methane production.However,methane emission studies using bibliometric tools in livestock are lacking.Given the negative impact of climate change on the ecosystem and the rise in methane emissions,it is essential to conduct a bibliometrics study to provide an overview and research trends.We used the Bibliometrix package and VOSviewer to decipher bibliometric indices for methane emissions in cattle farms(MECF).Current dataset were collected from the Web of Science(Core Collection)database,and 8,998 publications were analyzed.The most co-occurring keywords scientists preferred were methane(1,528),greenhouse gas(443),methane emissions(440),and cattle(369).Methane was the most frequently used keyword in the published scientific literature.Thematic evolution of research themes and trend results highlighted carbon dioxide,methane,dairy cattle,cattle,and risk factors during 1999–2017.Chinese Academy of Sciences ranked on top with 485 publications,followed by Agriculture&Agri-Food Canada,University of Colorado,National Oceanic and Atmospheric Administration,and Aarhus University.Chinese Academy of Sciences was also the most cited organization,followed by the University of Colorado,Agriculture&Agri-Food Canada,National Oceanic and Atmospheric Administration,and United States Geological Survey.Source analysis showed that the Science of the Total Environment was cited with the highest total link strength.Science of the Total Environment ranked first in source core 1 with 290 citation frequencies,followed by Journal of Dairy Science with 223 citation frequencies.Currently,no bibliometric study has been conducted on MECF,and to fill this knowledge gap,we carried out this study to highlight methane emissions in cattle farms,aiming at a climate change perspective.In this regard,we focused on the research productivity of countries authors,journals and institutions,co-occurrence of keywords,evolution of research trends,and collaborative networking.Based on relevance degree of centrality,methane emissions and greenhouse gases appeared as basic themes,cattle,and dairy cattle appeared as emerging/declining themes,whereas,methane,greenhouse gas and nitrous oxide appeared to fall amongst basic and motor themes.On the other hand,beef cattle,rumen and dairy cow seem to be between motor and niche themes,and risk factors lie in niche themes.The present bibliometric analysis provides research progress on methane emissions in cattle farms.Current findings may provide a framework for understanding research trends and themes in MECF research.
基金supported by the National Natural Science Foundation of China(Nos.51978052 and 22306012)the National Key Research and Development Program of China(No.2023YFC3711300)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110578).
文摘Acidic-and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes.Elevating temperature can accelerate hydrolytic kinetics and improve efficiency.In this work,magnetic sulfonated polypropylene resin(Fe_(3)O_(4)@PS-S)composites were reported for acidic-thermal hydrolysis of tylosin by employing the acidic feature of sulfonic group,the dielectric effect of resin,and the magnetic-loss effect of magnetite under microwave irradiation.As observed,a rapid and complete mitigation 100 mg/L of tylosin was achieved within 15 min by the catalysts.Acidic cleavage of tylosin was fulfilled by sulfonic groups in the composites,and microwave thermal accelerated the hydrolysis reactions due to the dielectric and magnetic-loss effects.Differentiating the dielectric and magnetic-loss effects through electromagnetic analyses indicated that the latter contributed more in converting microwave energy to heat.The interactions under multiple operational conditions were quantitatively fitted using the Behnajady model and visually demonstrated,which indicated that a synergic effect of microwave thermal-and acidichydrolyses contributed to the efficient mitigation of tylosin.The transformation products were identified and the pathways were supposed.Cleaving deoxyaminosugars groups and destructing lactone structures led to reduced antibacterial potential and toxicity reduction.The acute toxicity of tylosin and transformation products to fish,daphnia,and green algae were all classified as non-toxic.This work suggested that this synergistic acid-thermal hydrolytic method is attractive and promising in pretreating tylosin production wastewater in field.
基金financially supported by the National Natural Science Foundation of China(Nos.12275027,11875088,12205016,61474142 and 61974162)the Young Elite Scientists Sponsorship Program by CAST(No.2023QNRC001)the Fund of Innovation Center of Radiation Application(No.KFZC2021020801).
文摘The present study reports large room-temperature ferromagnetism in Co and Tb co-doped GaN films and further investigates the correlation between the doping concentration and the magnetic moment.X-ray photoelectron spectroscopy(XPS)and X-ray diffraction(XRD)measurements confirm that most of the dopants are incorporated into the GaN lattice.Photoluminescence(PL)and Raman spectra results reveal that post-annealing repaired most of lattice defects induced by ion implantation.The ZFC/FC curves show a blocked phase related to Co precipitates in Co single-doped GaN system and this phase is suppressed by the incorporation of Tb ions in the co-doped GaN systems.Although the magnetic properties were enhanced with the co-implantation of Co and Tb ions,the magnetic moment introduced by each ion slightly decreased with increasing Tb concentration.Density functional theory(DFT)calculations suggest that a high doping concentration of Tb atoms leads to the antiferromagnetic phase in the nearest position between Co and Tb ions.Appropriate co-doping with Co and Tb ions in GaN favors the development of enhanced ferromagnetism with no secondary phase.Our study not only offers valuable insights for understanding the magnetic characteristics of co-doped GaN,but also highlights the viability of developing room-temperature diluted magnetic semiconductors by appropriately co-doping TM and RE elements.
基金supported by the grants provided by Zhuhai People's Hospital,China(Grant No.:2021KYQD-03)the National Natural Science Foundation of China(Grant No.:22176016).
文摘Fibroblast activation protein(FAP)is overexpressed in cancer-associated fibroblasts across various cancer types.Numerous radiolabeled FAP inhibitors(FAPIs)(Fig.S1A)currently under clinical investigation have shown remarkable potential in cancer theranostics.
基金supported by the National Natural Science Foundation of China(Grant No.:81903794)Macao Science and Technology Development Fund(Grant Nos.:0031/2022/AGJ,0014/2022/ITP,005/2023/SKL and 001/2023/ALC)+2 种基金Guangdong Basic and Applied Basic Research Foundation(Grant No.:2024A1515030214)Guangdong-Macao Science and Technology Innovation Joint Research Special Fund(Grant No.:2023A0505020013)the Research Committee of the University of Macao(Grant Nos.:SRG2022-00035-ICMS,MYRG-CRG2022-00016-ICMS,MYRG2023-00205-ICMS,and MYRG2023-00234-ICMS-UMDF)。
文摘Medicinal and edible plants(MEPs)have attracted increasing interest worldwide due to their natural origin,reliable efficacy,and minimal side effects in recent years.However,the complex and fluctuating levels of inherent chemical constituents and exogenous hazardous contaminants have triggered widespread concerns about their efficacy and safety.Developing analytical methods for both active components and exogenous contaminants concealed in these samples is central to the quality evaluation,in which sample preparation is crucial.This paper systematically reviewed the evolution of standard sample preparation methods,microextraction techniques based on novel solvents and nanomaterials,and innovative integrated techniques from 2019.Accordingly,their merits and weaknesses were discussed by showing fruitful applications in identifying and quantifying active components in these plants.Further,successful applications for analyzing exogenous contaminants were prominently showcased,highlighting the management of pesticides,heavy metals,mycotoxins,and polycyclic aromatic hydrocarbons(PAHs).Finally,forthcoming trends in sample preparation techniques were delineated to illuminate the development and implementation of more advanced sample preparation technologies.
基金funded by the 2023 Scientific Research Platforms and Projects of Guangdong Provincial Education Department,Grant Number 2023WQNCX079.
文摘Background:The Teaching Personal and Social Responsibility(TPSR)model in physical education(PE)has been shown to promote Social and emotional competence(SEC).However,the underlying mechanisms through which TPSR enhances SEC,particularly in university students within the Chinese context,remain unclear.This study aims to explore the effects of TPSR and the mediating roles of self-efficacy and grit in improving SEC.Methods:71 Chinese university students were in the TPSR group,and 39 in the Traditional Teaching Model(TTM)control group,assessed before and after a 14-week intervention.The Adapted Social and Emotional Competence Scale(ASECS),General Self-Efficacy Scale(GSES),and Short Grit Scale(SGS)were used for measurement.A mixed-design ANOVA assessed TPSR’s effects,with post-hoc t-tests for pre-post differences and mediation analysis for underlying mechanisms.Results:The mixed-design ANOVA revealed a significant interaction between time and intervention on SEC.The TPSR group showed significant improvement from pre-test to post-test(t(70)=−2.63,p=0.011,Cohen’s d=−0.31),whereas the TTM control group did not(t(38)=1.40,p=0.170,Cohen’s d=0.22).The TPSR group also showed a significant increase in self-efficacy(t(70)=−3.67,p<0.001,Cohen’s d=−0.44),while no change was observed in the TTM group(t(38)=0.62,p=0.540,Cohen’s d=0.10).No significant effects were found for grit(F=0.342,p=0.560).Mediation analysis confirmed that self-efficacy significantly mediated the effects of the TPSR intervention on SEC(95%CI:0.0277 to 0.2897).Conclusion:The TPSR intervention led to significant improvements in university students’SEC and self-efficacy,with no significant changes observed in grit.Self-efficacy served as a mediator in the relationship between the intervention and SEC.
基金the National Key Research and Development Plan of China(2017YFC1702500).
文摘This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 batches of market samples in China.The samples were extracted with acetonitrile,cleaned up with primary secondary amine(PSA)and octadecylsilane(C18)and determined by GC-MS/MS in multiple reaction monitoring(MRM)mode.Matrix-matched calibration was recommended to combat the matrix effect.A good linearity was observed in the range of 10−500 ng/mL with correlation coefficients≥0.9950.The mean recoveries for most of the pesticides were in the range of 70%−120%with RSD<20%.The limits of detection ranged 0.28–2.00μg/kg,while the limits of quantification were 0.94–6.65μg/kg.Following the application of“top-down”approach,the expanded measurement uncertainty for all the analytes was<30%.The proposed method was successfully applied to determine pesticide residues in 20 market samples in China,where 9 pesticides were detected and quintozene exceeded the criteria domestically and abroad.
基金This study was supported by the Guangdong introducing innovative and entrepreneurial teams(No.2019ZT08L213)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0403)+2 种基金the National Natural Science Foundation of China(Nos.51979044 and 42177045)the Young Talent Project of Beijing Normal University at Zhuhai(No.310432101)We also thank the support received from China Scholarship Council(CSC)for providing a graduate fellowship to Y.C.(No.202006120356).
文摘The degradation of metoprolol(MTP)by the UV/sulfite with oxygen as an advanced reduction process(ARP)and that without oxygen as an advanced oxidation process(AOP)was comparatively studied herein.The degradation of MTP by both processes followed the first-order rate law with comparable reaction rate constants of 1.50×10^(-3)sec^(−1)and 1.20×10^(-3)sec^(−1),respectively.Scavenging experiments demonstrated that both e^(−)_(aq)and H·played a crucial role in MTP degradation by the UV/sulfite as an ARP,while SO_(4)^(·−)was the dominant oxidant in the UV/sulfite AOP.The degradation kinetics of MTP by the UV/sulfite as an ARP and AOP shared a similar pH dependence with a minimum rate obtained around pH 8.The results could be well explained by the pH impacts on the MTP speciation and sulfite species.Totally six transformation products(TPs)were identified from MTP degradation by the UV/sulfite ARP,and two additional ones were detected in the UV/sulfite AOP.The benzene ring and ether groups of MTP were proposed as the major reactive sites for both processes based on molecular orbital calculations by density functional theory(DFT).The similar degradation products of MTP by the UV/sulfite process as an ARP and AOP indicated that e^(−)_(aq)/H·and SO_(4)^(·−)might share similar reaction mechanisms,primarily including hydroxylation,dealkylation,and H abstraction.The toxicity of MTP solution treated by the UV/sulfite AOP was calculated to be higher than that in the ARP by the Ecological Struc-ture Activity Relationships(ECOSAR)software,due to the accumulation of TPs with higher toxicity.
基金the National Natural Science Foundation of China(82071999,61431002,31521063,and 61273287)the National 973 Program(2014CB846100).
文摘Dear Editor,Neuromodulation,a rapidly expanding field attracting wide attention over recent decades,facilitates human cognition,behavior,and pathology by modifying the activity of specific neural targets.Human brain functions can be modified by exogenous brain neuromodulation techniques that deliver physical energy(e.g.,electrical current or magnetic pulses)into the brain[1],such as deep brain stimulation,transcranial magnetic stimulation,and tran-scranial direct current stimulation.
基金Project supported by the Guangzhou Science and Technology Project(Grant No.20210202710)Scientific Research Project of Guangzhou University(Grant No.YG2020010)。
文摘We propose a novel rumor propagation model with guidance mechanism in hetero geneous complex networks.Firstly,the sharp threshold of rumor propagation,global stability of the information-equilibrium and information-prevailingequilibrium under R_(0)<1 and R_(0)>1 is carried out by Lyapunov method and LaSalle's invariant principle.Next,we design an aperiodically intermittent stochastic stabilization method to suppress the rumor propagation.By using the Ito formula and exponential martingale inequality,the expression of the minimum control intensity is calculated.This method can effectively stabilize the rumor propagation by choosing a suitable perturb intensity and a perturb time ratio,while minimizing the control cost.Finally,numerical examples are given to illustrate the analysis and method of the paper.
基金supported by the National Natural Science Foundation of China(No.21973005)。
文摘As the major and abundant type of glucosinolates(GL)in plants,sinigrin has potential functions in promoting health and insect defense.The final step in the biosynthesis of sinigrin core structure is highly representative in GL compounds,which corresponds to the process from 3-methylthiopropyl ds-GL to 3-methylthiopropyl GL catalyzed by sulfotransferase(SOT).However,due to the lack of the crystallographic structure of SOT complexed with the 3-methylthiopropyl GL,little is known about this sulfonation process.Fortunately,the crystal structure of SOT 18 from Arabidopsis thaliana(At SOT18)containing the substance(sinigrin)similar to 3-methylthiopropyl GL has been determined.To understand the enzymatic mechanism,we employed molecular dynamics(MD)simulation and quantum mechanics combined with molecular mechanics(QM/MM)methods to study the conversion from ds-sinigrin to sinigrin catalyzed by AtSOT18.The calculated results demonstrate that the reaction occurs through a concerted dissociative mechanism.Moreover,Lys93,Thr96,Thr97,Tyr130,His155,and two enzyme peptide chains(Pro92-Lys93 and Gln95-Thr96-Thr97)play a role in positioning the substrates and promoting the catalytic reaction by stabilizing the transition state geometry.Particularly,His155 acts as a catalytic base while Lys93 acts as a catalytic acid in the reaction process.The presently proposed concerted dissociative mechanism explains the role of At SOT18 in sinigrin biosynthesis,and could be instructive for the study of GL biosynthesis catalyzed by other SOTs.
基金supported in part by the National Key R&D Funding(No.2018YFE0206900).
文摘In this paper,a new bevel-tip flexible needle path planning method based on the bee-foraging learning particle swarm optimization(BFL-PSO)algorithm and the needle retraction strategy in 3D space is proposed to improve the puncture accuracy and shorten the puncture distance in the case of multiple puncture targets.First,the movement of the needle after penetrating the human body is analyzed,and the objective function which includes puncture path error,puncture path length,and collision function is established.Then,the BFL-PSO algorithm and the needle retraction strategy are analyzed.Finally,medical images of the tissue to be punctured are obtained by medical imaging instruments,i.e.,magnetic resonance(MR),and the 3D model of the punctured environment is constructed by 3D Slicer to obtain the environment information on targets and obstacles,and the path of flexible needle is carried out based on the BFL-PSO optimization algorithm and the needle retraction strategy.The simulation results show that,compared with other path planning methods in the related literature,the new path planning method proposed in this paper has higher path planning accuracy,shorter puncture distance,and good adaptability to multi-target path planning problems.
基金the Scientific Research Fund of Beijing Normal University(Grant No.28704-111032105)the Start-up Research Fund from BNU-HKBU United International College(Grant No.R72021112)+2 种基金The research of Guanghui Hu was partially supported by the FDCT of the Macao S.A.R.(0082/2020/A2)the National Natural Science Foundation of China(Grant Nos.11922120,11871489)the Multi-Year Research Grant(2019-00154-FST)of University of Macao,and a Grant from Department of Science and Technology of Guangdong Province(2020B1212030001).
文摘In Li and Ren(Int.J.Numer.Methods Fluids 70:742–763,2012),a high-order k-exact WENO finite volume scheme based on secondary reconstructions was proposed to solve the two-dimensional time-dependent Euler equations in a polygonal domain,in which the high-order numerical accuracy and the oscillations-free property can be achieved.In this paper,the method is extended to solve steady state problems imposed in a curved physical domain.The numerical framework consists of a Newton type finite volume method to linearize the nonlinear governing equations,and a geometrical multigrid method to solve the derived linear system.To achieve high-order non-oscillatory numerical solutions,the classical k-exact reconstruction with k=3 and the efficient secondary reconstructions are used to perform the WENO reconstruction for the conservative variables.The non-uniform rational B-splines(NURBS)curve is used to provide an exact or a high-order representation of the curved wall boundary.Furthermore,an enlarged reconstruction patch is constructed for every element of mesh to significantly improve the convergence to steady state.A variety of numerical examples are presented to show the effectiveness and robustness of the proposed method.
基金the National Natural Science Foundation of China,China(Grant No.52227804,52174010)Strategic Cooperation Technology Projects of CNPC and CUPB,China(Grant No.ZLZX2020-01)+1 种基金Sinopec key laboratory of drilling completion and fracturing of shale oil and gas,China(Grant No.35800000-22-ZC0699-0004)the Key Projects of Scientific Research Plan in Colleges and Universities of Xinjiang Uygur Autonomous Region,China(Grant No.XJEDU20211028)。
文摘The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(<33 L/s in Case 4) is employed, the cuttings bed completely blocks the borehole near the step surface and causes a stuck pipe directly. If the flow rate increases to the “low flow rate” interval(33-35 L/s in Case 4), a smaller flow rate instead facilitates borehole cleaning. If the flow rate is large enough to be in the “high flow rate” interval(>35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than those of other tripping velocities. As long as the applied tripping velocity is not within the “dangerous velocity”(0.4-0.5 m/s in Case 5) interval in the backreaming operation, the risk of the stuck pipe can be controlled validly. Finally, through the factors analyses of the annular geometry,particle properties, and fluid properties in Section 5, it can be found that the “low flow rate”, “high flow rate” and “dangers flow rate” tend to decrease and the “dangerous velocity” tends to increase with the conditions more favorable for hole cleaning. This study has some guiding significance for risk prediction and parameter setting of the backreaming operation.
基金supported in part by the Science and Technology Development Fund,Macao SAR FDCT/085/2018/A2the Guangdong Basic and Applied Basic Research Foundation(2019A1515111185)。
文摘This paper presents a robust filter called the quaternion Hardy filter(QHF)for color image edge detection.The QHF can be capable of color edge feature enhancement and noise resistance.QHF can be used flexibly by selecting suitable parameters to handle different levels of noise.In particular,the quaternion analytic signal,which is an effective tool in color image processing,can also be produced by quaternion Hardy filtering with specific parameters.Based on the QHF and the improved Di Zenzo gradient operator,a novel color edge detection algorithm is proposed;importantly,it can be efficiently implemented by using the fast discrete quaternion Fourier transform technique.From the experimental results,we conclude that the minimum PSNR improvement rate is 2.3%and the minimum SSIM improvement rate is 30.2%on the CSEE database.The experiments demonstrate that the proposed algorithm outperforms several widely used algorithms.
基金supported by the National Natural Science Foundation of China(Nos.22006131 and 22276171)the Zhejiang Provincial Natural Science Foundation of China(No.LQ20B070010)+1 种基金the China Postdoctoral Science Foundation(Nos.2020T130598 and 2019M662106)the Fund of Zhuhai Science and Technology Bureau,China(No.ZH22017003210025PWC)。
文摘Photocatalysis using the abundant solar energy is an environmentally friendly and efficient way to degrade organic matter.Covalent triazine frameworks(CTFs),a new class of metal-free organic semiconductors responsive to visible light,are promising materials for water treatment.In this study,an original CTF,namely CTF-1,was modified by S-doping to form CTFSx,which were used as metal-free catalysts for degradation of methyl orange(MO)and bisphenol A(BPA).The outcomes demonstrated that the photocatalytic degradation of MO and BPA by CTFSxwas superior to that by CTF-1,with better stability and reusability.Within 6 h,53.2%MO and 84.7%BPA were degraded by CTFS5,and the degradation rate constants were 0.145 h-1and 0.29 h-1,respectively,which were 3.6 and 5.8 times higher than those of CTF-1.Further investigation revealed that enhanced visible light absorption,a reduced degree of free carrier recombination,rapid separation and transfer of photogenerated electrons and holes,and improved·OH oxidation capacity were important factors contributing to the significantly enhanced photocatalytic activity.The S-doping method effectively improved the light absorption performance,electronic structure,and modulation band structure of CTF-1.This work highlights the potential application of low-cost metal-free catalysts driven by visible light for the removal of organic pollutants from wastewater.
基金Project supported by National Key R&D Program of China(Grant No.2017YFA0402600)the National Natural Science Foundation of China(Grant Nos.11690023,11373014,and 11633001)+2 种基金Beijing Talents Fund of Organization Department of Beijing Municipal Committee of the CPCthe Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB23000000)the Interdiscipline Research Funds of Beijing Normal University。
文摘Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,instead of the traditional single-mode approximation method in the relativistic setting.We find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of acceleration.Meanwhile,our results also reveal the interesting behavior of the Gaussian steering asymmetry,which increases for a specific range of accelerated parameter and then gradually approaches to a finite value.Such finding is well consistent and explained by the well-known Unruh effect,which could significantly destroy the one-side Gaussian quantum steering.Finally,our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites,since the effects of acceleration are equal to the effects of gravity according to the equivalence principle.
基金supported by the National Natural Science Foundation of China(No.22306178 and 22176155)Outstanding Youth Talents of Sichuan Science and Technology Program(No.22JCQN0061)+1 种基金National Natural Science Foundation of China(No.22306012)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110578).
文摘In semiconductor photocatalysts,the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment.To solve the serious problem of electron−hole pair recombination in perylene diimide(PDI)organic semiconductors,we loaded ferric hydroxyl oxide(FeOOH)on PDI materials,successfully prepared novel FeOOH@PDI photocatalytic materials,and constructed a photo-Fenton system.The system was able to achieve highly efficient degradation of BPA under visible light,with a degradation rate of 0.112 min^(−1)that was 20 times higher than the PDI system,and it also showed universal degradation performances for a variety of emerging organic pollutants and anti-interference ability.The mechanism research revealed that the FeOOH has the electron trapping property,which can capture the photogenerated electrons on the surface of PDI,effectively reducing the compounding rate of photogenerated carriers of PDI and accelerating the iron cycling and H2O2 activation on the surface of FeOOH at the same time.This work provides new insights and methods for solving the problem of easy recombination of carriers in semiconductor photocatalysts and degrading emerging organic pollutants.
基金partially supported by the National Natural Science Foundation of China (11671273 and 11931010)key research project of the Academy for Multidisciplinary Studies of CNU and Beijing Natural Science Foundation (1192001).
文摘In this article,we study the initial boundary value problem of the two-dimensional nonhomogeneous incompressible primitive equations and obtain the local existence and uniqueness of strong solutions.The initial vacuum is allowed.
基金This work is supported mainly by the National Key Research and Development Program of China(Grant No.2018YFE0204000)the National Natural Science Foundation of China(Grant Nos.21975245,U20A20206,51972300,12004094,and 32101004)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB43000000)the Science and Technology Research and Development Program of Handan(Grant No.21422111246)Prof.Y.Huang.also acknowledges the support from the Doctoral Special Fund Project of Hebei University of Engineering.Prof.K.Liu.appreciates the support from Youth Innovation Promotion Association,the Chinese Academy of Sciences(Grant No.2020114)the Beijing Nova Program(Grant No.2020117)Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515110578).
文摘Developing low-cost,efficient,and stable photocatalysts is one of the most promising methods for large-scale solar water splitting.As a metal-free semiconductor material with suitable band gap,graphitic carbon nitride(g-C_(3)N_(4))has attracted attention in the field of photocatalysis,which is mainly attributed to its fascinating physicochemical and photoelectronic properties.However,several inherent limitations and shortcomings—involving high recombination rate of photocarriers,insufficient reaction kinetics,and optical absorption—impede the practical applicability of g-C_(3)N_(4).As an effective strategy,vacancy defect engineering has been widely used for breaking through the current limitations,considering its ability to optimize the electronic structure and surface morphology of g-C_(3)N_(4) to obtain the desired photocatalytic activity.This review summarizes the recent progress of vacancy defect engineered g-C_(3)N_(4) for solar water splitting.The fundamentals of solar water splitting with g-C_(3)N_(4) are discussed first.We then focus on the fabrication strategies and effect of vacancy generated in g-C_(3)N_(4).The advances of vacancy-modified g-C_(3)N_(4) photocatalysts toward solar water splitting are discussed next.Finally,the current challenges and future opportunities of vacancy-modified g-C_(3)N_(4) are summarized.This review aims to provide a theoretical basis and guidance for future research on the design and development of highly efficient defective g-C_(3)N_(4).
