Single nucleus/cell RNA-seq of the chicken hypothalamicpituitaryovarian axis offers new insights into the molecular regulatory mechanisms of ovarian development

The hypothalamic-pituitary-ovarian(HPO)axis represents a central neuroendocrine network essential for reproductive function.Despite its critical role,the intrinsic heterogeneity within the HPO axis across vertebrates and the complex intercellular interactions remain poorly defined.This study provides the first comprehensive,unbiased,cell type-specific molecular profiling of all three components of the HPO axis in adult Lohmann layers and Liangshan Yanying chickens.Within the hypothalamus,pituitary,and ovary,seven,12,and 13 distinct cell types were identified,respectively.Results indicated that the pituitary adenylate cyclase activating polypeptide(PACAP),follicle-stimulating hormone(FSH),and prolactin(PRL)signaling pathways may modulate the synthesis and secretion of gonadotropin-releasing hormone(GnRH),FSH,and luteinizing hormone(LH)within the hypothalamus and pituitary.In the ovary,interactions between granulosa cells and oocytes involved the KIT,CD99,LIFR,FN1,and ANGPTL signaling pathways,which collectively regulate follicular maturation.The SEMA4 signaling pathway emerged as a critical mediator across all three tissues of the HPO axis.Additionally,gene expression analysis revealed that relaxin 3(RLN3),gastrin-releasing peptide(GRP),and cocaine-and amphetamine regulated transcripts(CART,also known as CARTPT)may function as novel endocrine hormones,influencing the HPO axis through autocrine,paracrine,and endocrine pathways.Comparative analyses between Lohmann layers and Liangshan Yanying chickens demonstrated higher expression levels of GRP,RLN3,CARTPT,LHCGR,FSHR,and GRPR in the ovaries of Lohmann layers,potentially contributing to their superior reproductive performance.In conclusion,this study provides a detailed molecular characterization of the HPO axis,offering novel insights into the regulatory mechanisms underlying reproductive biology.

Design and dynamic analysis of single-axis integrated inertia measurement device

The structure and measurement theory of a single-axis integrated inertia measurement device are discussed in this paper.The acceleration and angle velocity can be detected by the proposed sensor at the same time.The ki- netic model of the device is also established.In addition,the signal generation of the single-axis integrated inertia measurement device is analyzed and simulated.The results of the model are consistent with simulation result.

Underactuated spacecraft angular velocity stabilization and three-axis attitude stabilization using two single gimbal control moment gyros

Angular velocity stabilization control and attitude stabilization control for an underactuated spacecraft using only two single gimbal control moment gyros （SGCMGs） as actuators is investigated. First of all, the dynamic model of the underactuated spacecraft is established and the singularity of different configurations with the two SGCMGs is analyzed. Under the assumption that the gimbal axes of the two SGCMGs are installed in any direction, and that the total system angular momentum is not zero, a state feedback control law via Lyapunov method is designed to globally asymptotically stabilize the angular velocity of spacecraft. Under the assumption that the gimbal axes of the two SGCMGs are coaxially installed along anyone of the three principal axes of spacecraft inertia, and that the total system angular momentum is zero, a discontinuous state feedback control law is designed to stabilize three-axis attitude of spacecraft with respect to the inertial frame. Furthermore, the singularity escape of SGCMGs for the above two control problems is also studied. Simulation results demonstrate the validity of the control laws.

Single Phase Induction Motor Drive with Restrained Speed and Torque Ripples Using Neural Network Predictive Controller

In industrial drives, electric motors are extensively utilized to impart motion control and induction motors are the most familiar drive at present due to its extensive performance characteristic similar with that of DC drives. Precise control of drives is the main attribute in industries to optimize the performance and to increase its production rate. In motion control, the major considerations are the torque and speed ripples. Design of controllers has become increasingly complex to such systems for better management of energy and raw materials to attain optimal performance. Meager parameter appraisal results are unsuitable, leading to unstable operation. The rapid intensification of digital computer revolutionizes to practice precise control and allows implementation of advanced control strategy to extremely multifaceted systems. To solve complex control problems, model predictive control is an authoritative scheme, which exploits an explicit model of the process to be controlled. This paper presents a predictive control strategy by a neural network predictive controller based single phase induction motor drive to minimize the speed and torque ripples. The proposed method exhibits better performance than the conventional controller and validity of the proposed method is verified by the simulation results using MATLAB software.

Research on the Unsteady Hydrodynamic Characteristics of Vertical Axis Tidal Turbine

The unsteady hydrodynamic characteristics of vertical axis tidal turbine are investigated by numerical simulation based on viscous CFD method. The starting mechanism of the turbine is revealed through analyzing the interaction of its motion and dynamics during starting process. The operating hydrodynamic characteristics of the turbine in wave-current condition are also explored by combining with the linear wave theory. According to possible magnification of the cyclic loads in the maximum power tracking control of vertical axis turbine, a novel torque control strategy is put forward, which can improve the structural characteristics significantly without effecting energy efficiency.

Experimental study of rock-breaking with an offset single cone bit

An experimental study of rock-breaking with an offset single cone bit was completed on the bit bench test equipment. Data such as transmission ratio, weight on bit （WOB）, rate of penetration （ROP） and torque on bit were acquired in the experiments. Based on analyzing the experimental results, several conclusions were drawn as follows. The transmission ratio of the offset single-cone bit changed slightly with rotary speed of bit, weight on bit and offset distance. The rate of penetration of the offset singlecone bit increased with increase of WOB and off＇set distance. The torque on bit increased with increase of offset distance under the same WOB and bit rotary speed, decreased with increase of bit rotary speed under the same WOB. The rock-breaking mechanism of the offset single-cone bit was a scraping action. This indicates that the offset single-cone bit is a chipping type bit.

Optimization of Blade Motion of Vertical Axis Turbine

In this paper,a method is proposed to improve the energy efficiency of the vertical axis turbine.First of all,a single disk multiple stream-tube model is used to calculate individual fitness.Genetic algorithm is adopted to optimize blade pitch motion of vertical axis turbine with the maximum energy efficiency being selected as the optimization objective.Then,a particular data processing method is proposed,fitting the result data into a cosine-like curve.After that,a general formula calculating the blade motion is developed.Finally,CFD simulation is used to validate the blade pitch motion formula.The results show that the turbine＇s energy efficiency becomes higher after the optimization of blade pitch motion;compared with the fixed pitch turbine,the efficiency of variable-pitch turbine is significantly improved by the active blade pitch control;the energy efficiency declines gradually with the growth of speed ratio;besides,compactness has lager effect on the blade motion while the number of blades has little effect on it.

Computational Fluid Dynamics Analysis of Multi-Bladed Horizontal Axis Wind Turbine Rotor

The principal objective of this work was to investigate the 3D flow field around a multi-bladed horizontal axis wind turbine (HAWT) rotor and to investigate its performance characteristics. The aerodynamic performance of this novel rotor design was evaluated by means of a Computational Fluid Dynamics commercial package. The Reynolds Averaged Navier-Stokes (RANS) equations were selected to model the physics of the incompressible Newtonian fluid around the blades. The Shear Stress Transport (SST) k-ω turbulence model was chosen for the assessment of the 3D flow behavior as it had widely used in other HAWT studies. The pressure-based simulation was done on a model representing one-ninth of the rotor using a 40-degree periodicity in a single moving reference frame system. Analyzing the wake flow behavior over a wide range of wind speeds provided a clear vision of this novel rotor configuration. From the analysis, it was determined that the flow becomes accelerated in outer wake region downstream of the rotor and by placing a multi-bladed rotor with a larger diameter behind the forward rotor resulted in an acceleration of this wake flow which resulted in an increase the overall power output of the wind machine.

Optimal orbit transfer of single-tether E-sail with inertially fixed spin axis

This study analyzes the optimal transfer trajectory of a spacecraft propelled by a spinstabilized electric solar wind sail(E-sail)with a single conducting tether and a spin axis with a fixed direction in an inertial(heliocentric)reference frame.The approach proposed in this study is useful for rapidly analyzing the optimal transfer trajectories of the current generation of small spacecraft designed to obtain in-situ evidence of the E-sail propulsion concept.In this context,starting with the recently proposed thrust model for a single-tether E-sail,this study discusses the optimal control law and performance in a typical two-dimensional interplanetary transfer by considering the(binary)state of the onboard electron emitter as the single control parameter.The resulting spacecraft heliocentric trajectory is a succession of Keplerian arcs alternated with propelled arcs,that is,the phases in which the electron emitter is switched on.In particular,numerical simulations demonstrated that a single-tether E-sail with an inertially fixed spin axis can perform a classical mission scenario as a circle-to-circle two-dimensional transfer by suitably varying a single control parameter.

Atomistic simulation of the structural evolution in magnesium single crystal under c-axis tension

Molecalar dynamics simulation is applied to investigate the microstructure evolution of magnesium single crystals under c-axis extension at different temperatures. At low temperatures, both {1012} and {1011} twins are observed. At elevated temperatures, {1011} twining decreases quickly with increasing temperature, while the amount of {1012} twins increases. The （1012} twin is found to be the main deformation mechanism under the c-axis tension in the magnesium single crystal. Meanwhile, shear bands are also observed during deformation. When the temperature is beyond 500 K, the non-basal plane slip due to the thermal .activation is found. The stress-strain curves related with deformation behavior at atomistic scale are presented.

均匀流场下平单轴光伏支架扭转气动失稳特征试验研究

由于发电量明显高于固定式光伏系统,平单轴光伏发电系统近些年得到了广泛的应用。平单轴光伏支架由于扭转刚度较低,在大风天气下容易出现扭转气动失稳现象,从而造成支架结构破坏。为了进一步深入了解该振动的发生条件和机理,本研究通过节段模型测振风洞试验研究结构自振频率、倾角、阻尼等参数对扭转气动失稳的影响,分析了气动阻尼和气动刚度随着风速和倾角的变化规律。研究表明,平单轴光伏支架的扭转气动失稳表现出较强的气动耦合效应,气动阻尼和气动刚度是影响平单轴光伏支架气动失稳的重要参数,对风速和倾角的变化较为敏感,该失稳现象具备自激振动的特点;扭转刚度的提高在某些倾角下可以有效地限制振幅,同时可提高结构在各倾角的临界风速;扭转气动失稳的倾角范围为-15°~20°,0°倾角附近临界风速较高,若采用小倾角进行保护时,建议将大风保护角度设为0°。

旋转惯导姿态误差补偿方法分析

旋转惯导能够实现误差自补偿,从而提高系统导航精度。但旋转惯导中的旋转结构较为复杂,存在轴系的非正交误差、测角误差等,导致姿态输出随着旋转而发生波动,影响着惯导姿态解调输出的精度。针对惯导姿态误差补偿方法,选取4种常用的拟合补偿方法进行讨论,并结合实际采集数据,进行试验比对与分析,为后续工程应用提供参考。

螺杆机用并轴双转子永磁电机齿槽力矩机理分析与抑制

针对并轴双转子永磁电机过大的齿槽力矩以及转矩脉动大等电磁问题,采用传统单个槽齿槽转矩理论以及双转子电机边端力矩波动理论进行分析,计算了并轴双转子电机齿槽力矩的特殊组成成分以及其各部分转矩的谐波阶次。分析改变磁极偏心距和转子斜极对电机齿槽力矩和转矩特性的影响。采用响应面法构建电机的多目标优化模型,通过改变永磁体偏心距和斜极块数来约束电机的优化变量,并采取约束关系以及优化目标求解出最优转子结构参数。构建有限元模型,验证齿槽力矩理论的正确性。对比采用最优转子结构参数下电机的电磁性能与优化前电机的电磁性能,优化后电机的齿槽力矩、转矩脉动等电磁性能进一步提升,验证了采用磁极偏心和转子斜极复合结构的有效性。

螺旋扭曲升阻复合型垂直轴风力机气动性能分析

提出了一种新型升阻复合型垂直轴风力机。阻力型风轮是由双层典型的萨沃纽斯型风轮组成,而升力型风轮是由螺旋扭曲一定角度的达里厄NACA0018翼型风轮组成。阻力型风轮在内,升力型风轮在外,二者用传动轴和离合器相连接。在低风速时由阻力型风轮带动升力型风轮旋转,高风速时二者各自旋转,互不影响。首先,基于计算流体力学(Computational fluid dynamics,CFD)软件对其启动及气动性能进行了仿真,分析了风轮表面的压力和风速分布。然后,分别对复合型风力机和单达里厄型风力机的启动风速和输出功率进行了测量。结果表明:复合型风力机的启动风速要小于单达里厄型的启动风速,而输出功率的差别并不大。最后,探讨了单达里厄风力机不同风速下叶尖速比与转矩系数和风能利用率的关系,确定了在叶尖速比为1.9时可将阻力型风轮和升力型风轮分离,在风速为8 m/s且叶尖速比为3时风力机的风能利用率最高,为40.6%。

利用孟德尔随机化分析日间过度思睡人群肠道菌群特点

目的探讨日间过度思睡(excessive daytime sleepiness,EDS)人群的肠道菌群变化特点。方法利用全基因组关联分析(genome-wide association study,GWAS)数据进行两样本孟德尔随机化分析,将肠道菌群作为暴露因素,EDS作为结局因素,以单核苷酸多态性(single nucleotidepolymorphism,SNP)作为工具变量,使用多种方法筛查EDS的潜在致病肠道微生物。通过使用不同的敏感度分析,确保孟德尔随机化分析结果的稳健性。结果综合多重分析结果,发现丁酸单胞菌、消化球菌、嗜胆菌、厌氧菌、瘤胃球菌和粪球菌在EDS人群中的丰度相对较高,而颤螺旋菌和脱硫弧菌的丰度相对较低。结论EDS人群存在肠道菌群失调,通过改变饮食结构、使用益生菌等措施调整肠道菌群结构是否可改善EDS有待于今后进一步研究证实。

基于SMT单片机的双轴太阳能智能追光系统的设计

为提高太阳能发电效率,文章设计了一种基于SMT单片机的双轴太阳能智能追光系统。系统通过光敏器件采用双轴跟踪方式根据太阳光照强度实时调整光伏电池板的方向,使光伏板接收太阳辐射的效率最高。系统实时采集光照强度参数并显示,由单片机控制电机“智慧”追踪太阳,亦可通过按键切换为手动模式控制步进电机四向翻转。若光照不够,可以通过充电器为系统充电使其正常工作。

不同布置形式平单轴光伏支架颤振性能研究

对1V和2V两类不同布置形式平单轴光伏支架开展缩尺比为1/6的弹性悬挂节段模型测振风洞试验,研究了倾角(-60°~60°)、阻尼水平和光伏组件之间有无间隙对结构颤振性能的影响.结果表明:1V在-30°~30°倾角下发生明显的扭转颤振,2V在±10°、±20°和±30°时发生明显的扭转颤振;对于两类支架,结构颤振临界无量纲风速随倾角绝对值的增大先减小后增大,最大差值超过3.87倍(1V)和2.45倍(2V),且相同工况下,负倾角颤振性能优于正倾角;建议选择0°作为结构大风保护角度;1V和2V结构颤振性能随阻尼比的增大而提升,但和2V相比1V颤振性能提升对于阻尼比更不敏感;光伏组件之间的间隙对结构颤振性能基本无影响.

冻结黏土单轴动态力学特性及本构模型研究

为研究动载荷下冻土破坏特性,利用SHPB试验系统开展应变率300s^(-1)~1000s^(-1)、含水率13%~22%冻土单轴动态冲击试验,并建立本构模型描述单轴冻土动力学响应行为。结果表明:(1)应力-应变曲线可以分为压密阶段、弹性阶段、塑形阶段和破坏阶段,应变率高于700s^(-1)时应力-应变曲线出现明显振荡;(2)抗压强度和弹性模量整体上与应变率呈正相关趋势,但应变率高于900s^(-1)时抗压强度增长速度减缓甚至负增长。最大应变与应变率呈一次函数关系,含水率对最大应变无影响;(3)结合Weibull统计分布、D-P准则以及Z-W-T方程并引入含水率项,建立能考虑不同含水率冻土损伤黏弹性本构模型,验证模型可靠性(R^(2)>0.90)。为冻土工程设计与施工提供一定参考。

基于正交试验的全金属单螺杆泵转子最大转矩研究

通过正交试验对全金属单螺杆泵进行流场仿真,收集了在不同因素、不同水平下全金属单螺杆泵转子所受到的最大转子转矩数据,对其进行方差分析。分析结果反映出了各因素与转子最大转矩之间的关系,并判断出不同因素与研究目标的相关性强弱,并通过曲线图反映了这一现象。

地基光电成像系统中单芯轴的设计与优化

在大俯仰角和极端温差条件下,保持地基光电成像系统主镜面形精度的稳定性是关键。文中提出了一种新型单芯轴支撑结构,旨在提高主镜在极端环境下的稳定性和热膨胀适应能力,从而保证面形精度。通过卡式第二定理深入分析单芯轴应力尺寸链参数对镜面误差的影响,并结合Isight平台和多岛遗传算法进行结构参数优化,实现了结构稳定性与面形精度的平衡。仿真结果表明,在不同环境条件下,主镜的均方根波前误差(RMS)均小于30 nm,峰值差(PV)小于120 nm,满足光学成像的高标准要求。此外,在ΔT=80℃、主镜光轴水平状态下,RMS和PV的优化率分别达到59.99%和23.2%,刚体位移的优化率高达21.96%,体现了设计的高效性。在20℃和40℃的控制室温条件下进行的激光干涉仪测试进一步证实了设计的有效性,以及与仿真结果的高度一致性。该研究为在大温差、大俯仰角条件下的地基光电成像系统中,中口径主镜的支撑结构设计提供了有力的参考,特别是在提高主镜面形精度方面具有重要意义。未来的研究将探讨该结构在更广泛温差和更大口径主镜下的应用,以及进一步优化其光学性能和结构稳定性。