N-doped graphene quantum dot-decorated N-TiO2/P-doped porous hollow g-C_(3)N_(4) nanotube composite photocatalysts for antibiotic photodegradation and H2 production

Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO_(2). We combined N-doped graphene quantum dots (N-GQDs), morphology regulation, and heterojunction construction strategies to synthesize N-GQD/N-doped TiO_(2)/P-doped porous hollow g-C_(3)N_(4) nanotube (PCN) composite photocatalysts (denoted as G-TPCN). The optimal sample (G-TPCN doped with 0.1wt% N-GQD, denoted as 0.1% G-TPCN) exhibits significantly enhanced photoabsorption, which is attributed to the change in bandgap caused by elemental doping (P and N), the improved light-harvesting resulting from the tube structure, and the upconversion effect of N-GQDs. In addition, the internal charge separation and transfer capability of0.1% G-TPCN are dramatically boosted, and its carrier concentration is 3.7, 2.3, and 1.9 times that of N-TiO_(2), PCN, and N-TiO_(2)/PCN(TPCN-1), respectively. This phenomenon is attributed to the formation of Z-scheme heterojunction between N-TiO_(2) and PCNs, the excellent electron conduction ability of N-GQDs, and the short transfer distance caused by the porous nanotube structure. Compared with those of N-TiO_(2), PCNs, and TPCN-1, the H2 production activity of 0.1%G-TPCN under visible light is enhanced by 12.4, 2.3, and 1.4times, respectively, and its ciprofloxacin (CIP) degradation rate is increased by 7.9, 5.7, and 2.9 times, respectively. The optimized performance benefits from excellent photoresponsiveness and improved carrier separation and migration efficiencies. Finally, the photocatalytic mechanism of 0.1% G-TPCN and five possible degradation pathways of CIP are proposed. This study clarifies the mechanism of multiple modification strategies to synergistically improve the photocatalytic performance of 0.1% G-TPCN and provides a potential strategy for rationally designing novel photocatalysts for environmental remediation and solar energy conversion.

轻质可排阻磁性分子印迹聚合物的制备及选择性分离和检测牛奶中痕量四环素

关注牛奶安全这一国计民生问题,将分子印迹前沿技术引入本科实验课堂,设计了一个综合实验。融合分子印迹、蛋白质排阻、磁性分离等技术制备得到磁性分子印迹聚合物,考察其性能,并以其作为固相萃取吸附剂,结合高效液相色谱,建立直接选择性检测牛奶样品中痕量四环素的新方法。本实验涉及材料化学、分析化学、仪器分析、食品化学等多学科知识,培养学生的科学素养、综合解决复杂问题的能力和创新性思维。印迹材料的设计和磁性分离过程富有创新性和趣味性,整个实验过程成本低廉、易操作、安全性高。通过本实验,学生能够了解分子印迹前沿技术,学习新检测方法的建立,巩固实验基础操作,提高数据采集和分析能力,加深对组分-性能-应用关系的理解。

Dual-ion carrier storage through Mg^(2+) addition for high-energy and long-life zinc-ion hybrid capacitor

Cation additives can efficiently enhance the total electrochemical capabilities of zinc-ion hybrid capacitors (ZHCs).However their energy storage mechanisms in zinc-based systems are still under debate.Herein,we modulate the electrolyte and achieve dual-ion storage by adding magnesium ions.And we assemble several Zn//activated carbon devices with different electrolyte concentrations and investigate their electrochemical reaction dynamic behaviors.The zinc-ion capacitor with Mg^(2+)mixed solution delivers 82 mAh·g^(-1)capacity at 1 A·g^(-1) and maintains 91%of the original capacitance after 10000 cycling.It is superior to the other assembled zinc-ion devices in single-component electrolytes.The finding demonstrates that the double-ion storage mechanism enables the superior rate performance and long cycle lifetime of ZHCs.

Phosphotungstic acid ionic liquid for efficient photocatalytic desulfurization:Synthesis,application and mechanism

An efficient mass transfer process is a critical factor for regulating catalytic activity in a photocatalytic desulfurization system.Herein,a phosphotungstic acid(HPW)active center is successfully composited with a quaternary ammonium phosphotungstate-based hexadecyltrimethylammonium chloride ionic liquid(CTAC-HPW)by the ion exchange method for the photocatalytic oxidative desulfurization of dibenzothiophene sulfide.The keggin structure of HPW and highly mass transfer performance of organic cations synergistically enhanced the photocatalytic activity towards the effective convertion of dibenzothiophene(DBT)with the excitation of visible light.The deep desulfurization(<10 mg·kg^(-1))is attained within 30 min,and well stability is demonstrated within 25 cycles.Moreover,the CTAC-HPW photocatalyst projects well selectivity to interference from coexisting compounds such as olefins and aromatic hydrocarbons and universality of dibenzothiophenes,for example,4-methyldibenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT).Ultimately,a possible photocatalytic desulfurization mechanism is proposed according to the Gaschromatography-mass spectrometry(GC-MS),proving that the final product is the corresponding sulfone.The trapping experiment and electron spin resonance(ESR)analysis confirmed that h^(+)and,COOH played critical roles in the oxidation process.The work offers a practicable strategy for efficiently converting DBT to DBTO_(2) with added value.

A Bitcoin Address Multi-Classification Mechanism Based on Bipartite Graph-Based Maximization Consensus

Bitcoin is widely used as the most classic electronic currency for various electronic services such as exchanges,gambling,marketplaces,and also scams such as high-yield investment projects.Identifying the services operated by a Bitcoin address can help determine the risk level of that address and build an alert model accordingly.Feature engineering can also be used to flesh out labeled addresses and to analyze the current state of Bitcoin in a small way.In this paper,we address the problem of identifying multiple classes of Bitcoin services,and for the poor classification of individual addresses that do not have significant features,we propose a Bitcoin address identification scheme based on joint multi-model prediction using the mapping relationship between addresses and entities.The innovation of the method is to(1)Extract as many valuable features as possible when an address is given to facilitate the multi-class service identification task.(2)Unlike the general supervised model approach,this paper proposes a joint prediction scheme for multiple learners based on address-entity mapping relationships.Specifically,after obtaining the overall features,the address classification and entity clustering tasks are performed separately,and the results are subjected to graph-basedmaximization consensus.The final result ismade to baseline the individual address classification results while satisfying the constraint of having similarly behaving entities as far as possible.By testing and evaluating over 26,000 Bitcoin addresses,our feature extraction method captures more useful features.In addition,the combined multi-learner model obtained results that exceeded the baseline classifier reaching an accuracy of 77.4%.

Bone marrow edema in a postpartum female following ankle sprain: a case report

Bone marrow edema(BME)is characterized by an accumulation of interstitial fluid within the bone marrow,the cancellous,hematopoietic compartment within bones.[1]BME is divided into two principal categories:idiopathic or primary BME,with an unknown etiology,and secondary BME,which occurs as a result of an identifiable underlying pathology.[2]Although the prevalence of BME is not limited to specific demographic parameters,it shows a predilection for males or individuals assigned male at birth,predominantly aged between the ages of 30 and 60 years,especially in cases of bone marrow edema syndrome(BMES),a rare idiopathic variant.[3]The etiological spectrum of BME is diverse,including oncological entities(such as acute myeloid leukemia and osteosarcoma),degenerative diseases(such as osteoarthritis),infectious processes(osteomyelitis),ischemic conditions(avascular necrosis),metabolic dysfunctions(osteoporosis),inflammatory disorders(rheumatoid arthritis),and traumatic injuries(such as stress fractures).[1,2]Clinically,BME primarily manifests as localized pain,often accompanied by joint effusion and warmth near the affected joint.Diagnostic protocols typically include physical examination,serological assays,bone marrow biopsies,dual-energy X-ray absorptiometry(DEXA)scans,magnetic resonance imaging(MRI),and ultrasonography,with computed tomography(CT)scans and radiographs being less effective.

Numerical simulation of materials-oriented ultra-precision diamond cutting:review and outlook

Ultra-precision diamond cutting is a promising machining technique for realizing ultra-smooth surface of different kinds of materials.While fundamental understanding of the impact of workpiece material properties on cutting mechanisms is crucial for promoting the capability of the machining technique,numerical simulation methods at different length and time scales act as important supplements to experimental investigations.In this work,we present a compact review on recent advancements in the numerical simulations of material-oriented diamond cutting,in which representative machining phenomena are systematically summarized and discussed by multiscale simulations such as molecular dynamics simulation and finite element simulation:the anisotropy cutting behavior of polycrystalline material,the thermo-mechanical coupling tool-chip friction states,the synergetic cutting responses of individual phase in composite materials,and the impact of various external energetic fields on cutting processes.In particular,the novel physics-based numerical models,which involve the high precision constitutive law associated with heterogeneous deformation behavior,the thermo-mechanical coupling algorithm associated with tool-chip friction,the configurations of individual phases in line with real microstructural characteristics of composite materials,and the integration of external energetic fields into cutting models,are highlighted.Finally,insights into the future development of advanced numerical simulation techniques for diamond cutting of advanced structured materials are also provided.The aspects reported in this review present guidelines for the numerical simulations of ultra-precision mechanical machining responses for a variety of materials.

3D Model Occlusion Culling Optimization Method Based on WebGPU Computing Pipeline

Nowadays,Web browsers have become an important carrier of 3D model visualization because of their convenience and portability.During the process of large-scale 3D model visualization based on Web scenes with the problems of slow rendering speed and low FPS(Frames Per Second),occlusion culling,as an important method for rendering optimization,can remove most of the occluded objects and improve rendering efficiency.The traditional occlusion culling algorithm(TOCA)is calculated by traversing all objects in the scene,which involves a large amount of repeated calculation and time consumption.To advance the rendering process and enhance rendering efficiency,this paper proposes an occlusion culling with three different optimization methods based on the WebGPU Computing Pipeline.Firstly,for the problem of large amounts of repeated calculation processes in TOCA,these units are moved from the CPU to the GPU for parallel computing,thereby accelerating the calculation of the Potential Visible Sets(PVS);Then,for the huge overhead of creating pipeline caused by too many 3D models in a certain scene,the Breaking Occlusion Culling Algorithm(BOCA)is introduced,which removes some nodes according to building a Hierarchical Bounding Volume(BVH)scene tree to reduce the overhead of creating pipelines;After that,the structure of the scene tree is transmitted to the GPU in the order of depth-first traversal and finally,the PVS is obtained by parallel computing.In the experiments,3D geological models with five different scales from 1:5,000 to 1:500,000 are used for testing.The results show that the proposed methods can reduce the time overhead of repeated calculation caused by the computing pipeline creation and scene tree recursive traversal in the occlusion culling algorithm effectively,with 97%rendering efficiency improvement compared with BOCA,thereby accelerating the rendering process on Web browsers.

The Biomass Dosage Influences the Effects of Diethyl Aminoethyl Hexanoate on Micropropagation of Echinacea purpurea (L.) Moench

The plant growth regulator diethyl aminoethyl hexanoate (DA-6) has proved highly effective on micropropagation of the medicinal plant purple coneflower (Echinacea purpurea (L.) Moench), however, sharp variation of the effects existed among explants in the same treatment, making the application of DA-6 in micropropagation difficult. In order to clarify factors that influencing the treating results of DA-6, explants with different biomass dosage were prepared and inoculated onto medium supplemented with different concentrations of DA-6. It was found that among the three kinds of biomass dosage explants, the lowest biomass explants required the lowest concentration of DA-6, and the highest biomass explants required the highest concentration of DA-6 for the best results on adventitious buds regeneration. Similar results were obtained when regenerated buds of three different biomass dosages were cultured. It could be concluded from the above experimental results that for achieving better DA-6 application results, the concentration of DA-6 should be determined not only by the types but also by the biomass dosage of the explants. The present finding might help to improve the micropropagation efficiency in E. purpurea, and might be applicable for other species

Phase evolution and properties of glass ceramic foams prepared by bottom ash,fly ash and pickling sludge

Municipal solid waste incineration products of bottom ash(BA),fly ash(FA),and pickling sludge(PS),causing severe environ-mental pollution,were transformed into glass ceramic foams with the aid of CaCO3 as a pore-foaming agent during sintering.The effect of the BA/FA mass ratio on the phase composition,pore morphology,pore size distribution,physical properties,and glass structure was investigated,with results showing that with the increase in the BA/FA ratio,the content of the glass phase,Si-O-Si,and Q3Si units decrease gradually.The glass transmission temperature of the mixture was also reduced.When combined,the glass viscosity decreases,causing bubble coalescence and uneven pore distribution.Glass ceramic foams with uniform spherical pores are fabricated.When the content of BA,FA,and PS are 35wt%,45wt%,and 20wt%,respectively,contributing to high performance glass ceramic foams with a bulk density of 1.76 g/cm3,porosity of 56.01%,and compressive strength exceeding 16.23 MPa.This versatile and low-cost approach provides new insight into synergistically recycling solid wastes.

Transcription factor ZmNAC126 plays an important role in transcriptional regulation of maize starch synthesis-related genes

Maize(Zea mays L.)is one of the most important food crops in the world,and starch is the main component of its endosperm.Transcriptional regulation plays a vital role in starch biosynthesis.However,it is not well understood in maize.We report the identification of the transcription factor ZmNAC126 and its role in regulation of starch synthesis in maize.Transcriptional expression of ZmNAC126 was higher in maize endosperm and kernels than in roots or stems.ZmNAC126 shared a similar expression pattern with starch synthesis genes during seed development,and its expression pattern was also consistent with the accumulation of starch.ZmNAC126 is a typical transcription factor with a transactivation domain between positions 201 and 227 of the amino acid sequence,is located in the nucleus,and binds to CACG repeats in vitro.Yeast one-hybrid assay revealed that ZmNAC126 bound the promoters of ZmGBSSI,ZmSSIIa,ZmSSIV,ZmISA1,and ZmISA2.Transient overexpression of ZmNAC126 in maize endosperm increased the activities of promoters pZmSh2,pZmBt2,pZmGBSSI,pZmSSIIIa,and pZmBT1 but inhibited the activities of pZmISA1 and pZmISA2.ZmNAC126 thus acts in starch synthesis by transcriptionally regulating targeted starch synthesis-related genes in maize kernels.

Water-oxygen interaction on marcasite(101)surface:DFT calculation

Marcasite(FeS2)is widespread in nature,its oxidation plays a vital role in acid mine drainage,mineral resource recovery,and photoelectric material applications.In this paper,the oxidation mechanism of marcasite has been studied for the first time using density functional theory(DFT).It is found that,unlike the oxidation of pyrite,the oxidation of marcasite merely occurs at surface S atoms.Under the coexistence of water and oxygen,S atoms around surface Fe atoms are replaced by O atoms.The surface S sites are initially oxidized to form S==O bonds,and continue to adsorb oxygen to gradually generate SO3^2-,SO4^2-species,and eventually FeSO4.In this process,H2O molecules participate in neither oxidation nor dissociation,and they are adsorbed on surface Fe sites in the form of molecules,i.e.,all O atoms in SO4^2-derive from oxygen rather than water molecules.

A GPU-based general numerical framework for plasma simulations in terms of microscopic kinetic equations with full collision terms

We have proposed a general numerical framework for plasma simulations on graphics processing unit clusters based on microscopic kinetic equations with full collision terms.Our numerical algorithm consistently deals with both long-range(classical forces in the Vlasov term)and short-range(quantum processes in the collision term)interactions.Providing the relevant particle masses,charges and types(classical,fermionic or bosonic),as well as the external forces and the matrix elements(in the collisional integral),the algorithm consistently solves the coupled multi-particle kinetic equations.Currently,the framework is being tested and applied in the field of relativistic heavy-ion collisions;extensions to other plasma systems are straightforward.Our framework is a potential and competitive numerical platform for consistent plasma simulations.

The interaction between grain boundary and tool geometry in nanocutting of a bi-crystal copper

Anisotropy is one central influencing factor on achievable ultimate machined surface integrity of metallic materials.Specifically,grain boundary has a strong impact on the deformation behaviour of polycrystalline materials and correlated material removal at the microscale.In the present work,we perform molecular dynamics simulations and experiments to elucidate the underlying grain boundaryassociated mechanisms and their correlations with machining results of a bi-crystal Cu under nanocutting using a Berkovich tool.Specifically,crystallographic orientations of simulated bi-crystal Cu with a misorientation angle of 44.1°are derived from electron backscatter diffraction characterization of utilized polycrystalline copper specimen.Simulation results reveal that blocking of dislocation motion at grain boundaries,absorption of dislocations by grain boundaries and dislocation nucleation from grain boundaries are operating deformation modes in nanocutting of the bi-crystal Cu.Furthermore,heterogeneous grain boundary-associated mechanisms in neighbouring grains lead to strong anisotropic machining behaviour in the vicinity of the grain boundary.Simulated machined surface morphology and machining force evolution in the vicinity of grain boundary qualitatively agree well with experimental results.It is also found that the geometry of Berkovich tool has a strong impact on grain boundary-associated mechanisms and resultant ploughing-induced surface pile-up phenomenon.

A General Method to Study the Sound Radiation of a Finite Cylindrical Shell Based on Elastic Theory

一个一般方法被建议与有弹性的理论学习有限的圆柱的壳的声音和颤动。这个方法通过有弹性的方程的分解和薄壳理论分析的有限的圆柱的壳的答案的结构获得的解开的 Helmholtz 方程的全面分析被开发。建议方法对壳和任何频率的任意的厚度理论上合适。另外，通过方法获得的结果能被用来决定薄壳理论的申请的范围。而且，建议方法能处理薄壳理论限制的问题。另外，方法能对象使硬戒指的圆柱的壳，抑制的圆柱的壳，和两倍圆柱的壳那样的复杂的圆柱的壳的几种类型合适。

Effect of swirling addition on the liquid mixing performance in a T-jets mixer

Swirling addition to the stream is beneficial for the fluid mixing.This work aims to study the mixing process intensification in a conventional T-jets mixer by the swirling addition.After experimental verification by the planar laser-induced fluorescence technique,large eddy simulation with the dynamic kinetic energy sub-grid stress model is used to predict how the swirling strength(in terms of swirling number,S_(w))and swirling directions affect the mixing performance,e.g.the tracer concentration distribution,mixing time,and turbulent characteristics in the T-jets mixers,Predictions show that the swirling strength is the key factor affecting the mixing efficiency of the process.The overall mixing time,τ_(90),can be significantly reduced by increasing S_(w).Vortex analysis shows that more turbulent eddies appear in the collision zone and the turbulent kinetic energy dissipation rate increases obviously with the swirling addition.When S_(w) is kept constant,the mixing process can be accelerated and intensified by adding swirling to only one stream,to both streams with the opposite swirling directions,or to both streams with the same swirling directions.Amplification of the mixing process by enlarging the mixer size or increasing the flow rates is also optimized.Thus,this work provides a new strategy to improve the mixing performance of the traditional T-jets mixers by the swirling addition.

Epi-Brassinolide Positively Affects Chlorophyll Content and Dark-Reaction Enzymes of Maize Seedlings

Brassinosteroids participate in many physiological processes in plants;however,their regulatory roles on the activities of the enzymes involved in dark phase of photosynthesis remains elusive.In this study,detached leaves and protoplasts of maize seedlings were treated with epi-brassinolide(EBR)and brassinazole followed by the determination of the contents of chlorophyll(a+b)and soluble sugars,and the activity of dark reaction enzymes and the expression of the relevant genes.The results showed that chlorophyll(a+b)content increased by 7.4%under 0.1μM EBR treatment for 48 h;furthermore,chlorophyll(a+b)content increased by 34%in detached leaves that were continuously soaked in brassinazole.In addition,the transcription levels of glyceraldehyde3-phosphate dehydrogenase subunit A(GAPA),cytoplasmic FBPase(cyFBPase),ribulose-1,5-bisphosphate carboxylase small subunit(rbcS),phosphoenolpyruvate carboxylase(PEPC),fructose-1,6-bisphosphatase(FBPase),Rubisco activaseβsubunit(RCAβ),ribulose-l,5-bisphosphate carboxylase large subunit(rbcL),and glutathione reductase(GR)were 96.8%,48.4%,79.3%,41%,85.6%,133.3%,68.8%,and 119.8%higher,respectively,in 0.1μM EBR than in the control group.The activity of RCA and Rubisco and soluble sugar content increased by 53.4%,28.7%,and 35.4%under 0.1μM EBR.Brassinazole inhibits the expression of these genes.However,the transcription level,protein content,and activity of some dark-reaction enzymes cannot be increased at the same time under EBR treatment.These results indicate that the effect of EBR on dark-reaction is mainly in transcription level.

The Current Situation and Development Prospect of Mechanized Foxtail Millet Seeding in China

Based on the analysis of the present application of millet mechanization planting machines, we summarized the basic situation of millet mechanization planting machines at present stage to improve of planting efficiency and develop mechanization, and made suggestions on millet sowing mechanization.

Investigation on Wetland Resources of Bashan Lake in Chongqing Municipality

Based on the investigation on the wetland resources of Bashan Lake in Chongqing, the existing problems in the protection and utilization of Bashan Lake wetland and Chongqing Bashan National Wetland Park were analyzed. Specific suggestions were put forward, which provided basic references for the protection of Bashan Lake wetland and construction of Chongqing Bashan Lake National Wetland Park.

PLC Modeling and Checking Based on Formal Method

High reliability is the key to performance of electrical control equipment. PLC combines computer technology, automatic control technology and communication technology and becomes widely used for automation of industrial processes. Some requirements of complex PLC systems cannot be satisfied by the traditional verification methods. In this paper, an efficient method for the PLC systems modeling and verification is proposed. To ensure the high-speed property of PLC, we proposed a technique of “Time interval model” and “notice-waiting”. It could reduce the state space and make it possible to verify some complex PLC systems. Also, the conversion from the built PLC model to the Promela language is obtained and a tool PLC-Checker for modeling and checking PLC systems are designed. Using PLC-Checker to check a classical PLC example, a counter-example is found. Although the probability of this logic error occurs very small, it could result in system crash fatally.