Effects of shape and particle size on the photocatalytic kinetics and mechanism of nano-CeO_(2)

Nanomaterials have been widely applied to many fields because of their excellent photocatalytic performance.The performance is closely related to the catalytic kinetics,but it is not completely clear about the influencing regularities of shape and particle size on the photocatalytic kinetics of nanomaterials and the photocatalytic kinetic mechanism.In this paper,nano-CeO_(2)with different shapes and particle sizes were prepared,the kinetic parameters of adsorption and photocatalytic degradation were determined,and the effects of shape and particle size on the kinetics of adsorption and photocatalysis and photocatalytic mechanism were discussed.The results show that the shape and particle size have significant influences.With the decreases of diameter,the performances of adsorption and photocatalysis of nano-CeO_(2)are improved;and these performances of spherical nano-CeO_(2)are greater than those of linear nano-CeO_(2).The shape and particle size have no effects on the kinetic order and mechanism of the whole photocatalytic process.Then a generalized mechanism of photocatalytic kinetics of nanomaterials was proposed and the mechanism rate equation was derived.Finally,the conclusion can be drawn:the desorption of photodegradation products is the control step of photocatalytic kinetics,and the kinetic order of photocatalytic degradation reaction is 1.The mechanism is universal and all nanomaterials have the same photocatalytic kinetic mechanism and order.

Hyperoside promotes pollen tube growth by regulating the depolymerization effect of actin depolymerizing factor 1 on microfilaments in okra

Mature pollen germinates rapidly on the stigma,extending its pollen tube to deliver sperm cells to the ovule for fertilization.The success of this process is an important factor that limits output.The flavonoid content increased signi ficantly during pollen germination and pollen tube growth,which suggests it may play an important role in these processes.However,the speci fi c mechanism of this involvement has been little researched.Our previous research found that hyperoside can prolong the flowering period of Abelmoschus esculentus(okra),but its speci fic mechanism is still unclear.Therefore,in this study,we focused on the effect of hyperoside in regulating the actin-depolymerizing factor(ADF),which further affects the germination and growth of pollen.We found that hyperoside can prolong the effective pollination period of okra by 2-3-fold and promote the growth of pollen tubes in the style.Then,we used Nicotiana benthamiana cells as a research system and found that hyperoside accelerates the depolymerization of intercellular micro fi laments.Hyperoside can promote pollen germination and pollen tube elongation in vitro.Moreover,AeADFl was identi fied out of all AeADF genes as being highly expressed in pollen tubes in response to hyperoside.In addition,hyperoside promoted AeADF1-mediated micro filament dissipation according to micro filament severing experiments in vitro.In the pollen tube,the gene expression of AeADFl was reduced to 1/5 by oligonucleotide transfection.The decrease in the expression level of AeADFl partially reduced the promoting effect of hyperoside on pollen germination and pollen tube growth.This research provides new research directions for flavonoids in reproductive development.

Design of The Desirable Interface to Improve the High Energy Density in Fine-Scale Composites - Combined with the Modified Hybrid Processing

Due to the miniaturization of modern devices re-quire components with light weight,high integra-tion and the ability to store energy in as small vol-ume as possible.As a result,energy storage densitybecomes an important figure of merit for energy stor-age devices.In this paper,firstly,we discussedthe energy density in fine-grained lead zirconate tita-nate glass-ceramics composite with the help of

Surfactant-metal-organic framework complexes and their derivatives:advances in electrocatalysis

Metal-organic frameworks(MOFs)and their derivatives received more and more attention due to the diverse morphologies,rich porous structures,and tunable metal active sites,which have been widely used in energy-related electrocatalytic reactions.Surfactants,a class of compounds with hydrophilic and hydrophobic portions in the molecular structure,are able to modulate the properties of liquid and solid surfaces.Surfactants play a crucial role in controlling the shape and size of MOFs,which helps optimize electrocatalytic performance,especially in improving the exposure and accessibility of catalytic active sites.In this review,we first outline the types and applications of surfactants.Second,we describe the interface modulation and reaction mechanism of different surfactants during the forming of MOFs and their derivatives.Finally,we discuss the current applications of surfactant-modified MOFs and their derivatives in electrocatalysis.This review provides a better understanding of surfactantassistant structure regulation and electrocatalytic activity study of MOFs and their derivatives.

An integrative profiling of metabolome and transcriptome in the plasma and skeletal muscle following an exercise intervention in diet-induced obese mice

Exercise intervention at the early stage of type 2 diabetes mellitus(T2DM)can aid in the maintenance of blood glucose homeostasis and prevent the development of macrovascular and microvascular complications.However,the exercise-regulated pathways that prevent the development of T2DM remain largely unclear.In this study,two forms of exercise intervention,treadmill training and voluntary wheel running,were conducted for high-fat diet(HFD)-induced obese mice.We observed that both forms of exercise intervention alleviated HFD-induced insulin resistance and glucose intolerance.Skeletal muscle is recognized as the primary site for postprandial glucose uptake and for responsive alteration beyond exercise training.Metabolomic profiling of the plasma and skeletal muscle in Chow,HFD,and HFD-exercise groups revealed robust alterations in metabolic pathways by exercise intervention in both cases.Overlapping analysis identified nine metabolites,including beta-alanine,leucine,valine,and tryptophan,which were reversed by exercise treatment in both the plasma and skeletal muscle.Transcriptomic analysis of gene expression profiles in the skeletal muscle revealed several key pathways involved in the beneficial effects of exercise on metabolic homeostasis.In addition,integrative transcriptomic and metabolomic analyses uncovered strong correlations between the concentrations of bioactive metabolites and the expression levels of genes involved in energy metabolism,insulin sensitivity,and immune response in the skeletal muscle.This work established two models of exercise intervention in obese mice and provided mechanistic insights into the beneficial effects of exercise intervention on systemic energy homeostasis.

Aerodynamic optimization using passive control devices near the bogie cabin of high-speed trains

Bogies are responsible for a significant amount of aerodynamic resistance and noise,both of which negatively affect high-speed train performance and passenger comfort.In the present study,the passive control method is applied in designing the bogie cabins of a high-speed train to improve its aerodynamic characteristics.Two passive control measures are introduced,namely,adding a spoiler and creating diversion grooves near the bogie cabins.Furthermore,the aerodynamic and aeroacoustic characteristics of a high-speed train operating at 350 km/h under different control strategies are numerically investigated using the improved-delayed-detached-eddy simulation(IDDES)and the acoustic finite element method(FEM).The impacts of passive control devices on drag reduction,slipstream,and aerodynamic noise are presented and discussed.Numerical results reveal that the passive control devices have a major effect on the slipstream around the train.The amplitude of the fluctuating pressure is higher in the first half of the train than in the second half.The first bogie has the maximum amplitude of the acoustic pressure for both the train with and without passive devices.In the far field,the spoiler installation and placement of the diversion grooves in the front of the bogie cabin can significantly reduce aerodynamic drag and noise.Hence,as shown in this study,using passive control methods to improve the aerodynamic and aeroacoustic properties of high-speed trains can be a viable option.

炔雌醇环丙孕酮联合雷洛昔芬对多囊卵巢综合征不孕患者卵巢功能和妊娠率的影响

目的分析炔雌醇环丙孕酮联合雷洛昔芬对多囊卵巢综合征(PCOS)不孕患者卵巢功能和妊娠率的影响。方法抽取2018年2月至2020年2月周口市儿童医院收治的PCOS不孕患者106例,按随机数字表法分为联合组和单一组,每组53例。单一组采用雷洛昔芬治疗,联合组采用炔雌醇环丙孕酮联合雷洛昔芬治疗。比较两组的治疗效果和治疗前后血清性激素[雌二醇、促黄体生成素(LH)]水平、卵巢功能(卵巢体积、子宫内膜厚度)、子宫动脉血流动力学[阻力指数(RI)、搏动指数(PI)],比较两组患者的预后情况(排卵率、妊娠率)。结果联合组总有效率(96.23%,51/53)高于单一组(83.02%,44/53),P<0.05。治疗后,联合组雌二醇高于单一组,LH低于单一组(P<0.05)。治疗后,联合组卵巢体积小于单一组,子宫内膜厚度厚于单一组(P<0.05)。治疗后,联合组RI、PI指数均低于单一组(P均<0.05)。联合组排卵率(84.00%,42/50)、妊娠率(62.00%,31/50)均高于单一组(54.90%,28/51;31.37%,16/51),P<0.05。结论炔雌醇环丙孕酮联合雷洛昔芬治疗PCOS不孕的效果显著,可调节血清性激素水平,改善卵巢功能和子宫动脉血流动力学,提高排卵率和妊娠率。

DI-VTR:Dual inter-modal interaction model for video-text retrieval

Video-text retrieval is a challenging task for multimodal information processing due to the semantic gap between different modalities.However,most existing methods do not fully mine the intra-modal interactions,as with the temporal correlation of video frames,which results in poor matching performance.Additionally,the imbalanced semantic information between videos and texts also leads to difficulty in the alignment of the two modalities.To this end,we propose a dual inter-modal interaction network for video-text retrieval,i.e.,DI-vTR.To learn the intra-modal interaction of video frames,we design a contextual-related video encoder to obtain more fine-grained content-oriented video representations.We also propose a dual inter-modal interaction module to accomplish accurate multilingual alignment between the video and text modalities by introducing multilingual text to improve the representation ability of text semantic features.Extensive experimental results on commonly-used video-text retrieval datasets,including MSR-VTT,MSVD and VATEX,show that the proposed method achieves significantly improved performance compared with state-of-the-art methods.