On entire solutions of some Fermat type differential-difference equations

On one hand,we study the existence of transcendental entire solutions with finite order of the Fermat type difference equations.On the other hand,we also investigate the existence and growth of solutions of nonlinear differential-difference equations.These results extend and improve some previous in[5,14].

Experimental Study on Vortex-Induced Vibration of Rough Risers with Coupling Interference Effect Under Side-by-Side Arrangement

A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined flume.The roughness of the riser was characterized by arranging different specifications of surface attachments on the surface of the riser.Rough risers with three different roughnesses were arranged side by side with smooth risers to explore the VIV response of the riser under the combined action of roughness and interference effect,and to reveal the coupling mechanism between roughness and interference effect.The experimental results show that,compared with that of a smooth riser,the VIV of a rough riser under the coupling interference effect has a wider"lock-in"region,and the displacement decreases more significantly at a high reduced velocity,which is more likely to excite higher-order modes and frequency responses.In addition,the displacement response and frequency response of the smooth riser are not significantly affected by wake interference from the rough riser,which is caused by the decrease of the wake region due to the delay of the boundary layer separation point of the rough riser.

Experimental Study on Vortex-Induced Vibration of Rough Risers Coupling with Interference Effect in Tandem Arrangement

In order to study the response law of vortex-induced vibration(VIV)of marine risers under the combined action of roughness and interference effects,and to reveal the coupling mechanism of roughness and interference effects on the riser,a VIV experiment of rough risers in tandem arrangement was conducted in a wave−current combined flume.The experiment characterized the risers’roughness by arranging different specifications of attachments on the surface of the risers.Three rough risers with different roughness and smooth risers were arranged in tandem arrangement,with the rough risers arranged downstream.The experimental results indicate that the suppression of the attachments on the downstream risers’vibration are more significant both in the CF and IL directions as the reduced velocity increases.For the downstream riser,the amplitude response of rough riser is more significantly weakened compared with the smooth one at high reduced velocity.For the upstream risers,changes in the roughness and spacing ratio have an impact on their‘lock-in’region.When the roughness of downstream risers is relatively large(0.1300)and the spacing between risers is small(S/D=4.0),the reduced velocity range of‘lock-in’region in the CF direction of upstream risers is obviously expanded,and the displacement in the‘lock-in’region is severer.

Interaction Mechanisms between Natural Debris Flow and Rigid Barrier Deflectors:A New Perspective for Rational Design and Optimal Arrangement

Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters.

ENTIRE SOLUTIONS OF HIGHER ORDER DIFFERENTIAL EQUATIONS WITH ENTIRE COEFFICIENTS HAVING THE SAME ORDER

In this paper,we consider entire solutions of higher order homogeneous differential equations with the entire coefficients having the same order,and prove that the entire solutions are of infinite lower order.The properties on the radial distribution,the limit direction of the Julia set and the existence of a Baker wandering domain of the entire solutions are also discussed.

The Application of Piano in Chinese Pop Music Arrangements

By exploring the application of piano in Chinese pop music arrangements,this article aims to enhance the understanding of the position of piano in pop music and provide useful insights and references for the future development of Chinese pop music.Starting from the unique position of piano in Chinese pop music arrangements,the article analyses in detail the specific applications of piano in Chinese pop music arrangements.The analysis finds that the piano has been deeply integrated into the bloodline of Chinese popular music and become an indispensable part.From simple melodic embellishments to complex arrangement ideas,the piano has injected endless vitality and vigor into popular music with its unique timbre and expressive power.

Effects of Spatial Row Arrangement and Time of Planting Intercrops on Performance of Groundnut (Arachis hypogaea L.) under Maize (Zea mays L.)—Groundnut Intercropping System in Ejura

In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.

Conductor Arrangement and Phase Sequence Optimization Scheme for 500 kV Four-Circuit Transmission Lines on Same Tower

The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors.Optimizing the conductor and phase sequence arrangement of multiple transmission lines is conducive to improving electromagnetic and electrostatic coupling caused by electromagnetic problems.This paper uses the ATP-EMTP simulation software to build a 500 kV multi-circuit transmission line on the same tower.It stimulates the induced voltage and current values of different line lengths,tower spacing,vertical and horizontal spacing between different circuits,phase sequence arrangement,and nominal tower height.Moreover,use the BP neural network optimized by a genetic algorithm to predict the induced voltage and current under the unknown conductor and phase sequence arrangement.Finally,based on multi-objective particle swarm algorithm to construct the optimization model of conductor arrangement scheme of overhead transmission line,combined with electromagnetic environment control index,determine the optimal conductor arrangement scheme by the size of particle fitness function,a significant reduction in induced voltages and currents between transmission lines and the four-circuit conductor layout scheme meeting the requirements of the electromagnetic environment is obtained,which provides a reference for the tower design of the transmission station project.

ENTIRE SOLUTIONS OF LOTKA-VOLTERRA COMPETITION SYSTEMS WITH NONLOCAL DISPERSAL

This paper is mainly concerned with entire solutions of the following two-species Lotka-Volterra competition system with nonlocal(convolution)dispersals:{u_(t)=k*u-u+u(1-u-av),x∈R,t∈R,vt=d(k*v-v)+rv(1-v-bu),c∈R,t∈R.(0.1)Here a≠1,b≠1,d,and r are positive constants.By studying the eigenvalue problem of(0.1)linearized at(ϕc(ξ),0),we construct a pair of super-and sub-solutions for(0.1),and then establish the existence of entire solutions originating from(ϕc(ξ),0)as t→−∞,whereϕc denotes the traveling wave solution of the nonlocal Fisher-KPP equation ut=k*u−u+u(1−u).Moreover,we give a detailed description on the long-time behavior of such entire solutions as t→∞.Compared to the known works on the Lotka-Volterra competition system with classical diffusions,this paper overcomes many difficulties due to the appearance of nonlocal dispersal operators.

A Class of Potentials for Hyperbolic Transcendental Entire Maps

We identify a class of transcendental entire maps of finite order, of disjoint-type, satisfying the rapid derivative growth condition. Within this class, we show that there exist hyperbolic transcendental entire maps that generate a large class of potentials which intersect the so-called tame potentials and form a distinct class of potentials. The methods and techniques derived from the thermodynamic formalism are applied to these potentials for transcendental entire maps acting on some subset of the Julia set which is conjugated to the shift map over a code space with a countable alphabet endowed with the euclidean induced metric on the complex plane.

Generation of irregular particle packing with prescribed statistical distribution, spatial arrangement, and volume fraction

A method for packing irregular particles with a prescribed volume fraction is proposed.Furthermore,the generated granular material adheres to the prescribed statistical distribution and satisfies the desired complex spatial arrangement.First,the irregular geometries of the realistic particles were obtained from the original particle images.Second,the Minkowski sum was used to check the overlap between irregular particles and place an irregular particle in contact with other particles.Third,the optimised advance front method(OAFM)generated irregular particle packing with the prescribed statistical dis-tribution and volume fraction based on the Minkowski sum.Moreover,the signed distance function was introduced to pack the particles in accordance with the desired spatial arrangement.Finally,seven biaxial tests were performed using the UDEC software,which demonstrated the accuracy and potential usefulness of the proposed method.It can model granular material efficiently and reflect the meso-structural characteristics of complex granular materials.This method has a wide range of applications where discrete modelling of granular media is necessary.

Tooth arrangement design of retractable DTH hammer bit used for drilling while casing

Down-the-hole(DTH)hammer with casing while drilling(CWD)is a technology that has been proven to be able to alleviate many of the problems faced by complex formations.However,the drill bit is suffered from rapid wear,low drilling efficiency,and high energy consumption due to the unreasonable tooth arrangement and impact energy selection in drilling process,which affect the application effect of this technology.ABAQUS software was used for numerical simulation of rock breaking behavior under impact load with the single,three,and five teeth arrangement drill bit respectively,to improve the application effect and solve the aforementioned technical problems.Based on the calculated parameters of tooth arrangement,we designed a novel drill bit for hard rocks and provided a theoretical basis for the tooth arrangement of largediameter drill bits.

低透煤层瓦斯超前排放钻孔布置方式优化研究

目的为有效解决低透气性煤层瓦斯突出问题,有效消除阵列布孔方式带来的瓦斯排放盲区以及对角圆相切布孔方式造成的钻孔数量增加、重复排放等问题。方法通过理论分析,在超前排放钻孔有效排放半径一定的情况下提出阵列菱形法优化超前排放孔的布置方式(R为有效排放半径,煤层走向排放孔的间距为√3R),其钻孔数量约为对角圆相切法的3/4,重复排放面积减少至11%,减少了对角圆相切布孔方式的重复排放面积,减少了钻孔的数量。结果运用COMSOL Multiphysics对阵列菱形法布孔方式进行数值模拟运算,结果表明,阵列菱形法布孔方式排放20 d后,钻孔有效排放半径内整体瓦斯压力低于0.5 MPa,排放100 d后瓦斯压力低于0.30 MPa,卸压效果优于对角圆相切布孔方式的。将阵列法和对角圆相切法两种布孔方式排放100 d时钻孔周围的瓦斯压力分布情况与阵列菱形法布孔方式排放20 d时的分布情况交叉对比,发现阵列菱形法布孔方式卸压速率更快,卸压范围更广。结论提出阵列菱形法设计钻孔布孔方式,并运用COMSOL Multiphysics对3种钻孔布孔方式的卸压情况进行数值模拟运算,对比发现,阵列菱形法钻孔布孔方式比阵列法和对角圆相切法布孔方式更具优势,且在相同时间内卸压速率更快、卸压范围更广,对低透煤层预防瓦斯突出具有重要的意义。

湖南农产品加工业高质量发展战略研究

湖南农产品加工业实现了持续平稳较快发展,已发展成为湖南省三大万亿产业之一,但加工业依然存在大而不强、产业链不长且不完整等问题,高质量发展面临诸多挑战。为此,应按照全产业链发展思维,以结构调整优化与转型升级为主线,以延链补链强链为目标,构建农产品加工业全产业链“63”一体化发展体系,即大力实施“厚植产业发展基础”“做强产业发展主体”“做大总量做优质量”“做强产业发展支撑”“健全质量保障体系”“提升精准管理服务能力”等六大战略重点,提出“强化组织领导与部门统筹”“强化考核评估与实施监督”“构建协同发展机制”等三大战略保障措施,打造层次分明且功能齐全的现代农产品加工业体系,助力建设全国知名的一流农产品加工业发展高地,加快促进湖南省农产品加工业的高质量发展,为全面推进农业农村现代化、实现乡村振兴提供重要支撑。

数字经济与实体经济融合的制度安排

数字经济与实体经济融合是建设现代化产业体系的现实需要,也是推动实体经济高质量发展的内在要求。然而,数据产权、交易、分配和治理制度不健全、核心技术存在短板、数字技术与传统产业脱节、寡头垄断平台“一家独大”、数字基础设施供求不匹配、数字鸿沟较大为数字经济与实体经济融合带来了现实挑战。数据要素制度、数字技术制度、数字产业制度、数字平台制度、数字基础设施制度可为数字经济与实体经济融合发展提供关键内核、强劲动能、生态体系、中介载体和坚实底座。因此,数字经济与实体经济走向深度融合需要加强相关的制度安排,未来应完善以“数据二十条”为核心的数据要素制度、“卡脖子”技术攻关制度、数字产业融合制度、数字平台治理制度、数字基础设施共投共建共享制度和数字鸿沟弥合制度。

认知负荷理论视域下教材插图编配研究

认知负荷理论是一种适合解释教材插图学习的理论,它认为学习者的学习活动主要在容量有限的工作记忆中进行,工作记忆有两条信息加工通道,分别负责处理文字内容和图片内容。有待工作记忆处理的文字内容和图片内容要彼此对应,编配方式应有利于学习者整合图文信息,且不宜让学习者的工作记忆负荷过重。在现行教材的代表性样本中,教材编配的大部分插图与文字内容相对应,教材主要采用嵌入、邻近、内容关联词、符号标志关联词等技术帮助学生建立插图与相应文字内容之间的联系,但插图与文字的有效关联技术运用得较少,教材插图的编配缺乏明确的规范。为规范教材插图的编配,应将“对应”作为插图选配的原则,适当提升嵌入技术的使用比例,充分且到位地运用图文关联技术,开展图文关联技术组合效果的研究,加强不同学科教材编写者在插图编配上的相互借鉴。

辅导员在高校“三全育人”中的角色定位与实现路径

构建全员全过程全方位育人格局是落实立德树人根本任务的内在要求和战略举措。高校辅导员在“三全育人”体系中肩负着重要使命,是全员育人中的主导者、全程育人中的统筹者、全方位育人中的串联者。然而,囿于思想认识、能力素质、边界划分等方面的现实困境问题,真正实现好这一角色担当,还需要从激发内生动力、加大资源供给、明确职责边界等方面持续用力,不断提升新时代辅导员育人能力和水平。

产业融合与新质生产力共同赋能物流业降本增效

目前,物流业降本增效存在“社会物流成本等同于物流成本”“降低全社会物流成本就是降低物流企业的服务价格”“我国物流成本远远高于发达国家”三个认识误区和“中小微物流企业居多”“全球经济下行”两个现实瓶颈。产业融合、新质生产力与物流业降本增效之间的逻辑关系是:产业融合通过物流业与其他产业的高效互动,从供应链视角进行全链条的资源匹配和优化升级,为社会物流降本提供源动力。新质生产力通过技术革命性突破、生产要素的创新性配置以及产业深度转型升级,实现生产效率提升的质变,成为全社会物流成本降低的重要手段。在此基础上,考虑到产业融合和新质生产力对物流业降本增效的赋能是一个全方位多层次的过程,从战略设计-战术控制-操作执行三个层面,提出以产业融合和新质生产力共同赋能物流业降本增效的实施策略:在战略设计层面,要依托物流数智化技术,开展良好的物流服务设计、以供应链订单为驱动,开展供应链体系重构设计、基于供应链可视化技术,进行物流成本控制图设计。在战术控制层面,要运用新技术和新模式,减少商品流通环节,利用产业集群和服务共享机制,缩短物流运输距离、构建轴辐射物流网络,重塑集疏运物流体系、重构生态链伙伴关系,减少交易成本。在操作执行层面,要发挥物流标准化基础性引领性作用,减少流通堵点、推动供应链金融体系建设,赋能企业降本、加大直达运输比例,减少流通损耗。为保障产业融合和新质生产力共同赋能物流业降本增效策略的顺利实施,应发挥重点产业链建设示范效应,警惕物流降本带来的就业新问题,支持中小物流企业通过技术创新实现降本以及发挥平台赋能物流降本作用,为进一步推动我国物流业降本增效提供指导方向。

基于可逆固体氧化物电池的电氢耦合微电网全生命周期规划-运营研究

为促进实现“双碳”目标,新能源将成为未来能源供应的主体。考虑到高比例新能源对电力系统容量规划和调度运营带来的巨大挑战以及电氢能源需求量的持续增长对电力系统的影响,以微电网为研究对象,设计基于可逆固体氧化物电池的考虑源荷不确定性的电氢耦合微电网全生命周期规划-运营优化模型及其求解算法。首先,针对风光产电、电氢负荷等多种不确定因素,设计包含微电网全生命周期内各年份不同典型日的数据,以构成随机场景。其次,对电氢耦合微电网容量规划成本、全生命周期调度运营成本以及新能源年均渗透率等多个优化目标进行数学表达,并对各发电机组、可逆固体氧化物电池以及储氢库的规划-运营约束进行线性描述。然后,设计一种改进的增广ε约束算法求解模型的Pareto解集,并提出一种平衡决策方法从解集中获取最佳规划-调度方案。最后,仿真结果表明,所提方法能均衡各优化目标,在保证新能源高渗透率的同时提升电氢耦合微电网的可靠性以及规划-运营经济性。

县级融媒体中心深度发展的几个关键问题

县级融媒体中心是地方党委政府“治县理政”的抓手与平台,作为一种战略安排,融媒体中心有其技术、经济、政治与文化时代背景,数字信息技术不断革新下的挑战与机遇,使得县级传统媒体必然转型为融媒体中心,因而其生产者构成、职能部门构成、渠道构成、产品构成、受众构成、社会构成等必然有新的规律和特点,但本质上依然是一种新闻机构。这就要求我们从宏观、中观、微观等层面来把握这种战略安排,对融媒体中心深度发展的逻辑遵循、核心构成、地方价值、舆论引导和文化建设的理解,就成为管理者、研究者和从业者所有工作的重中之重。