Numerical simulation of inlet placement on sewage characteristics in the rounded square aquaculture tank with single inlet

To improve the self-cleaning ability of aquaculture tank and the efficiency of circulating water,physical and numerical experiments were conducted on the influence of inlet structure on sewage discharge in a rounded square aquaculture tank with a single inlet.Based on the physical model of the tank,analysis of how inlet structure adjustment affects sewage discharge efficiency and flow field characteristics was conducted to provide suitable flow field conditions for sinkable solid particle discharge.In addition,an internal flow field simulation was conducted using the RNG k-εturbulence model in hydraulic drive mode.Then a solid-fluid multiphase model was created to investigate how the inlet structure affects sewage collection in the rounded square aquaculture tank with single inlet and outlet.The finding revealed that the impact of inlet structure is considerably affecting sewage collection.The conditions of C/B=0.07-0.11(the ratio of horizontal distance between the center of the inlet pipe and the tank wall(C)to length of the tank(B))andα=25°(αis the angle between the direction of the jet and the tangential direction of the arc angle)resulted in optimal sewage collection,which is similar to the flow field experiment in the rounded square aquaculture tank with single inlet and outlet.An excellent correlation was revealed between sewage collection and fluid circulation stability in the aquaculture tank.The present study provided a reference for design and optimization of circulating aquaculture tanks in aquaculture industry.

Effect of length-width ratio of rounded rectangle aquaculture tank in dual-diagonal-inlet layout on hydrodynamics

To adapt to the change of aquaculture workshop site,optimize the shape of aquaculture tanks and improve the utilization rate of breeding space,it is necessary to determine the appropriate length width ratio parameters of aquaculture tanks.In this paper,computational fluid dynamics(CFD)technology is adopted to study the flow field performance of aquaculture tanks with different L/B ratios(L:the length;B:the width,of aquaculture tank)and different jet direction conditions(lengthways jet and widthways jet).A three-dimensional numerical calculation model of turbulence in rounded rectangle aquaculture tanks in dual-diagonal-inlet layout was established.Jet directions are arranged lengthways and widthways,and the water flow velocity,resistance coefficient change,vorticity,etc.are analyzed under two working conditions.Results show that the flow field performance in aquaculture tank decreases with the increase of the L/B ratio.The flow field performed well when L/B was 1.0-1.3,sharply dropped at 1.4-1.6,and poor at 1.7-1.9.The results provided a theoretical basis for the design and optimization in flow field performance of the industrialized circulating aquaculture tanks.

无机微纳米粒子改性对碳纤维复合材料力学性能的影响

为评价无机微/纳米粒子改性对碳纤维复合材料力学性能的影响,采用真空辅助树脂传递模塑成型(VARTM)工艺分别制备了[±45/0/90]S铺层角度下纳米SiO_(2)、纳米Al_(2)O_(3)、微米SiO_(2)、微米Al_(2)O_(3)改性碳纤维环氧树脂基复合材料(CFRP)。对其横向拉伸、损伤阻抗及损伤容限性能进行测试,通过扫描电镜和水浸超声C扫描检测观察试件内部损伤状态,对比分析无机微/纳米粒子对复合材料的增韧机理。实验结果表明,相比未改性CFRP,无机微/纳米粒子改性CFRP的冲击损伤初始阈值能量显著提高,冲击损伤面积明显减小,纳米SiO_(2)改性碳纤维增强环氧树脂基复合材料(CF/EP/NSI)试件的横向拉伸断裂模式由单一的脆性断裂转为韧性断裂,最大冲击载荷和低速冲击后压缩强度(CAI)值达到了3484 N,62.4 MPa,相比未改性CFRP分别提升了30.4%,48.2%。[±45/0/90]S铺层角度下试件的冲击损伤形状为花生状,冲击后压缩破坏模式为穿过中间损伤区域的压缩破坏(LDM)。

Research and Application of 3G Electrical Safety Job Site Intelligent Monitoring Device

This paper describes the shortcomings and difficulties of power company security construction, such as site management for construction site security monitoring personnel is limited, in recent years , rural power grids and Urban Network alteration Faced with new situation. The use of advanced science and technology and communication terminal in order to better strengthen the means of power construction site safety supervision, improve the level of safety production supervision, design and development of a new electrical safety job site intelligent monitoring devices. The device consists of three parts of the remote wide angle 360 degrees of portable video surveillance equipment and 3G smart terminal equipment and portable battery. Through the application of such a device, professionals can remotely monitor the construction job site safety, diagnose, and effectively improve the security of the electricity sector management and reduce security risks and personnel on-site monitoring costs for improving the security of the entire power industry field operations with significance.

Distributed Generation Application in the Rural Areas of West China

In this paper, at first the appearance background electricity grid in the rural areas of west China, and its meaning as well as the concept and structure of DG technologies are resented, and a DG technologies mode of development in the rural areas of west China is given. The development ideas and the future development direction of DG in are compared and summarized. At last, the significance of DG in future development of the rural areas of west China is prospected and some problems to be especially considered in the domestic research on DG technologies are put forward.

(+)/(-)-Gerbeloid A,a pair of unprecedented coumarin-based polycyclic meroterpenoid enantiomers from Gerbera piloselloides:Structural elucidation,semi-synthesis,and lipid-lowering activity

A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.

Identification of niclosamide as a novel antiviral agent against porcine epidemic diarrhea virus infection by targeting viral internalization

Porcine epidemic diarrhea virus(PEDV),an enteropathogenic coronavirus,has catastrophic impacts on the global pig industry.However,there remain no effective drugs against PEDV infection.In this study,we utilized a recombinant PEDV expressing renilla luciferase(PEDV-Rluc)to screen potential anti-PEDV agents from an FDAapproved drug library in Vero cells.Four compounds were identified that significantly decreased luciferase activity of PEDV-Rluc.Among them,niclosamide was further characterized because it exhibited the most potent antiviral activity with the highest selectivity index.It can efficiently inhibit viral RNA synthesis,protein expression and viral progeny production of classical and variant PEDV strains in a dose-dependent manner.Time of addition assay showed that niclosamide exhibited potent anti-PEDV activity when added simultaneously with or after virus infection.Furthermore,niclosamide significantly inhibited the entry stage of PEDV infection by affecting viral internalization rather than viral attachment to cells.In addition,a combination with other small molecule inhibitors of endosomal acidification enhanced the anti-PEDV effect of niclosamide in vitro.Taken together,these findings suggested that niclosamide is a novel antiviral agent that might provide a basis for the development of novel drug therapies against PEDV and other related pathogenic coronavirus infections.

A review on hydrogen production from ammonia borane:Experimental and theoretical studies

Ammonia borane(NHsBH3,AB)is an ideal raw material of hydrogen production with higher hydrogen storage capacity.In this paper,the catalytic processes of AB dehydrogenation were described from different ways,including thermal dehydrogenation,hydrolysis,methanolysis,photocatalysis and photopiezoelectric synergy catalysis with experimental research and theoretical calculations.Catalyst models include bulk materials,two-dimensional materials,nanocluster particles and single/diatomic structures.Among them,the proportion of H2 released is different,and the reaction conditions are also different,which are suitable for different application scenarios.Through this review,we could have a preliminary comprehensive understanding of AB dehydrogenation reaction.

Wip1 inhibits neutrophil extracellular traps to promote abscess formation in mice by directly dephosphorylating Coronin-1a

Neutrophil extracellular traps (NETs) participate in the rapid inhibition and clearance of pathogens during infection;however, the molecular regulation of NET formation remains poorly understood. In the current study, we found that inhibition of the wild-type p53-induced phosphatase 1 (Wip1) significantly suppressed the activity of Staphylococcus aureus (S. aureus) and accelerated abscess healing in S. aureus-induced abscess model mice by enhancing NET formation. A Wip1 inhibitor significantly enhanced NET formation in mouse and human neutrophils in vitro. High-resolution mass spectrometry and biochemical assays demonstrated that Coro1a is a substrate of Wip1. Further experiments also revealed that Wip1 preferentially and directly interacts with phosphorylated Coro1a than compared to unphosphorylated inactivated Coro1a. The phosphorylated Ser426 site of Coro1a and the 28–90 aa domain of Wip1 are essential for the direct interaction of Coro1a and Wip1 and for Wip1 dephosphorylation of p-Coro1a Ser426. Wip1 deletion or inhibition in neutrophils significantly upregulated the phosphorylation of Coro1a-Ser426, which activated phospholipase C and subsequently the calcium pathway, the latter of which promoted NET formation after infection or lipopolysaccharide stimulation. This study revealed Coro1a to be a novel substrate of Wip1 and showed that Wip1 is a negative regulator of NET formation during infection. These results support the potential application of Wip1 inhibitors to treat bacterial infections.

Turning the V site in V@2D-BC_(3)N_(2)complex to high curvature state for efficient CO_(2)electroreduction to hydrocarbons

Hydrocarbons are promising products for CO_(2)electroreduction(CRR)while is impeded by the low selectivity.Turning the curvature of the active site is an effective strategy to change the adsorption properties and further regulate the product distribution and reactivity.Herein,we have designed a novel V single atom catalyst(SAC)based on rolled two-dimensional(2D)BC_(3)N_(2)substrate with different curvatures.The results have demonstrated that increased curvature can enhance the adsorption strength of CRR intermediates,which follows different mechanisms for systems with low and high curvature.This character eventually leads to the deviation away from the scaling line between Ead[CO]∼Ead[COOH]based on transition metals for V@2D-BC_(3)N_(2)systems.3-3 system is screened as the optimal candidate for hydrocarbons production due to the enhanced binding ability of adsorbates,which can increase the reactivity for hydrocarbons production and hinder the production of H2 and HCOOH simultaneously.

Highly active Fe_(36)Co_(44) bimetallic nanoclusters catalysts for hydrolysis of ammonia borane: The first-principles study

In this paper,Fe_(36)Co_(44)nanocluster structure is used to catalyze the hydrolysis reaction of ammonia borane to produce H_(2).Firstly,we complete the construction of Fe_(36)Co_(44)cluster structure and calculate the electronic properties of the cluster.By comparing the adsorption process of Ammonia Borane (AB) in active sites of the cluster,which have different Effective Coordination Number (ECN),the qualitative relationship between ECN and the catalytic activation of AB is clarified,and the optimal catalytic active site is obtained.Then,from the perspective of different reaction paths,we study the hydrolysis reaction of AB in multiple paths,and obtain 5 different reaction paths and energy profiles.The calculation results show that in the case of N–H bond priority break (path 5),the reaction has the minimum rate-determining step (RDS) barrier (about 1.02 e V) and the entire reaction is exothermic (about 0.40 e V).So,path 5 is an optimal catalytic reaction path.This study will have an important guiding significance for the study of the AB hydrolysis reaction mechanism.

Atramacronoids A-C,three eudesmanolide sesquiterpene-phenol hybrids with an unprecedented C-C linkage from the rhizomes of Atractylodes macrocephala

Three eudesmanolide sesquiterpene-phenol hybrids,atramacronoids A-C(1-3),featuring an unusual6/6/5/5/6 skeleton furnished by forming an unexpected C-8-C-16 linkage,were obtained from the rhizomes of Atractylodes macrocephala.Their structures and absolute configurations were elucidated by spectroscopic data analysis,chemical calculations,combined with X-ray diffractions.The plausible biosynthetic pathways for compounds 1-3 are proposed.Surprisingly,compound 1 exhibited cytotoxicity against SGC-7901 cells by inducing cells apoptosis,which might relate to the promotion of synthesis of neutrophil elastase.

Computational design of BC_(3)N_(2) based single atom catalyst for dramatic activation of inert CO_(2) and CH4 gasses into CH_(3)COOH with ultralow CH_(4) dissociation barrier

The production of CH_(3)COOH from CO_(2)and CH_(4) has stimulated much interest due to the high energy density of C2 species.Various kinds of catalysts have been developed while the high dissociation barrier of CH_(4) and low selectivity still hinders the efficiency of the reaction.We have herein proposed a novel catalyst with single metals loaded on 2D BC_(3)N_(2) substrate(M@2D-BC_(3)N_(2))based on density functional theory.Among numerous candidates,Pt@2D-BC_(3)N_(2) possesses the most favorable reactivity with an ultralow barrier of CH_(4) splitting(0.26 e V),which is due to the efficient capture ability of CH_(4) on Pt site.Besides,the selectivity for CH_(3)COOH is also very high,which mainly stems from the unique electronic properties of molecules and substrate:The degenerated states,including s,px,pyand pz,in CO_(2)reflects the existence of delocalizedπbonds between C and O.This can interact with states of Pt(s),Pt(pz),Pt(dxz),Pt(dyz),and Pt(z2)in Pt@2D-BC_(3)N_(2).The kinetics model also proves that our system can promote CH_(3)COOH production via simply increasing the temperature or the coverage of CH_(4) and CO_(2).Our results provide a reasonable illustration in clarifying mechanism and propose promising candidates with high reactivity for further study.

Effects of perinatal stress on the metabolites and lipids in plasma of dairy goats

Dairy goats experience metabolic stress during the peripartal period,and their ability to navigate this stage of lactation is related to the occurrence and development of metabolic diseases.Unlike dairy cows,there is a lack of comprehensive analysis of changes in the plasma profiles of peripartal dairy goats,particularly using high-throughput techniques.A subset of 9 clinically-healthy dairy goats were used from a cohort of 96 primiparous Guanzhong dairy goats(BCS,2.75±0.15).Blood samples were collected at seven time points around parturition(d 21,14,7 before parturition,the day of kidding,and d 7,14,21 postpartum),were analyzed using untargeted metabolomics and targeted lipidomics.The orthogonal partial least squares discriminant analysis model revealed a total of 31 differential metabolites including p-cresol sulfate,pyruvic acid,cholic acid,and oxoglutaric acid.The pathway enrichment analysis identified phenylalanine metabolism,aminoacyl-tRNA biosynthesis,and citrate cycle as the top three significantly-altered pathways.The Limma package identified a total of 123 differentially expressed lipids.Phosphatidylserine(PS),free fatty acids(FFA),and acylcarnitines(ACs)were significantly increased on the day of kidding,while diacylglycerols(DAG)and triacylglycerols(TAG)decreased.Ceramides(Cer)and lyso-phosphatidylinositols(LPI)were significantly increased during postpartum period,while PS,FFA,and ACs decreased postpartum and gradually returned to antepartum levels.Individual species of FFA and phosphatidylcholines(PC)were segregated based on the differences in the saturation and length of the carbon chain.Overall,this work generated the largest repository of the plasma lipidome and metabolome in dairy goats across the peripartal period,which contributed to our understanding of the multifaceted adaptations of transition dairy goats.

Research on entropy weight variation evaluation method for wind power clusters based on dynamic layered sorting

This paper presents an evaluation method for the entropy-weighting of wind power clusters that comprehensively evaluates the allocation problems of wind power clusters by considering the correlation between indicators and the dynamic performance of weight changes.A dynamic layered sorting allocation method is also proposed.The proposed evaluation method considers the power-limiting degree of the last cycle,the adjustment margin,and volatility.It uses the theory of weight variation to update the entropy weight coefficients of each indicator in real time,and then performs a fuzzy evaluation based on the membership function to obtain intuitive comprehensive evaluation results.A case study of a large-scale wind power base in Northwest China was conducted.The proposed evaluation method is compared with fixed-weight entropy and principal component analysis methods.The results show that the three scoring trends are the same,and that the proposed evaluation method is closer to the average level of the latter two,demonstrating higher accuracy.The proposed allocation method can reduce the number of adjustments made to wind farms,which is significant for the allocation and evaluation of wind power clusters.

Capture and separation of CO_(2)on BC_(3)nanosheets:A DFT study

In order to reduce the greenhouse effect caused by the rapid increase of CO_(2)concentration in the atmosphere,it is necessary to develop more efficient,controllable,and highly sensitive adsorbing materials.In this study,the adsorption behavior of CO_(2)on BC_(3)nanosheets under an external electric field was explored based on density functional theory(DFT).It was found that CO_(2)experienced a transition from physisorption to chemisorption in the electric field range of 0.0060-0.0065 a.u..In addition,the adsorption/desorption of CO_(2)is reversible and can be precisely controlled by switching on/off at the electric field of 0.0065 a.u..The selective adsorption of CO_(2)/H_(2)/CH_(4)by BC_(3)can also be used to realize gas separation and purification under different electric fields.This study highlighted the potential application of BC_(3)nanosheets as a high-performance,controllable material for CO_(2)capture,regeneration,and separation in an electric field.

Rich B active centers in Penta-B_(2)C as high-performance photocatalyst for nitrogen reduction

The photocatalytic nitrogen reduction reaction(NRR) has mild reaction conditions and only requires sunlight energy as a driving force to replace the traditional ammonia synthesis method. We herein investigate the catalytic activity and selectivity on Penta-B_(2)C for NRR by using density functional theory calculations. Penta-B_(2)C is a semiconductor with an indirect bandgap(2.328 e V) and is kinetically stable based on molecular dynamic simulations. The optical absorption spectrum of Penta-B;C is achieved in the ultraviolet and visible range. Effective light absorption is more conducive to generate photo-excited electrons and improving photocatalytic performances. Rich B atoms as activation sites in Penta-B_(2)C facilitate capturing N_(2). The activated N_(2)molecule prefers the side-on adsorption configuration on Penta-B_(2)C, which facilitates the subsequent reduction reaction. Among considered NRR mechanisms on Penta-B_(2)C, the best pathway prefers the enzymatic mechanism, only required a low onset potential of 0.23 V. The hydrogen evolution reaction is inhibited when the hydrogen adsorption concentration is increased or N_(2)molecules first occupy the adsorption sites. Our results indicate Penta-B_(2)C is a highly reactive and selective photocatalyst for NRR. Our work provides theoretical insights into the experiments and has guiding significance to synthesize efficient NRR photocatalysts.

Defect engineering for high-selection-performance of NO reduction to NH3 over CeO_(2)(111)surface:A DFT study

To reduce the greenhouse effect caused by the surgery of nitrogen-oxides concentration in the atmosphere and develop a future energy carrier of renewables,it is very critical to develop more efficient,controllable,and highly sensitive catalytic materials.In our work,we proposed that nitric oxide(NO),as a supplement to N_(2) for the synthesis of ammonia,which is equipped with a lower barrier.And the study highlighted the potential of CeO_(2)(111)nanosheets with La doping and oxygen vacancy(OV)as a high-performance,controllable material for NO capture at the site of Vo site,and separation the process of hydrogenation.We also reported that the E_(ads) of-1.12 eV with horizontal adsorption and the Bader charge of N increasing of 0.53|e|and O increasing of 0.17|e|at the most active site of reduction-OV predicted.It is worth noting thatΔG of NORR(NO reduction reaction)shows good performance(thermodynamically spontaneous reaction)to synthesize ammonia and water at room temperature in the theoretical calculation.

Prediction of stable BC_(3)N_(2)monolayer from first-principles calculations:Stoichiometry,crystal structure,electronic and adsorption properties

In this paper,a novel BC_(3)N_(2)monolayer has been found with a graphene-like structure using the developed particle swarm optimization algorithm in combination with ab initio calculations.The predicted structure meets the thermodynamical,dynamical,and mechanical stability requirements.Interestingly,the BC_(3)N_(2)plane shows a metallic character.Importantly,BC_(3)N_(2)has an in-plane stiffness comparable to that of graphene.We have also investigated the adsorption characteristics of CO_(2)on pristine monolayer and Mo functionalized monolayer using density functional theory.Subsequently,electronic structures of the interacting systems(CO_(2)molecule and substrates)have been preliminarily explored.The results show that Mo/BC_(3)N_(2)has a stronger adsorption capacity towards CO_(2)comparing with the pristine one,which can provide a reference for the further study of the CO_(2)reduction mechanism on the transition metal-functionalized surface as well as the new catalyst’s design.

Associative vs. dissociative mechanism: Electrocatalysis of nitric oxide to ammonia

Nitric oxide reduction to ammonia by electrocatalysis is the potential application in the elimination of smog and energy conversion. In this work, the feasibility of the application of two-dimensional metal borides(MBenes) in nitric oxide electroreduction reaction(NOER) was investigated through density functional theory calculations. Including the geometry and electronic structure of five kinds of MBenes, the adsorption of NO on the surface of these substrates, the selective adsorption of hydrogen protons during the hydrogenation process, and the overpotential in the electrocatalytic ammonia synthesis process. As a result, Mn B exhibited the most favorable catalytic performance according to the associative pathways,which is thermodynamically performed spontaneously, and WB has a minimum overpotential of 0.37 V vs. RHE in the process of ammonia production according to the dissociative pathway. Overall, our work is the first to explore the electrocatalytic NO through the dissociative mechanism to synthesize ammonia in-depth and proves that MBenes are efficient NO electrocatalytic ammonia synthesis catalysts. These research results provide a new direction for the development of electrocatalytic ammonia synthesis experimentally and theoretically.