A Single-Board Integrated Millimeter-Wave Asymmetric Full-Digital Beamforming Array for B5G/6G Applications

In this article,a single-board integrated millimeter-wave(mm-Wave)asymmetric full-digital beamforming(AFDBF)array is developed for beyond-fifth-generation(B5G)and sixth-generation(6G)communications.The proposed integrated array effectively addresses the challenge of arranging a large number of ports in a full-digital array by designing vertical connections in a three-dimensional space and successfully integrating full-digital transmitting(Tx)and receiving(Rx)arrays independently in a single board.Unlike the traditional symmetric array,the proposed asymmetric array is composed of an 8×8 Tx array arranged in a square shape and an 8+8 Rx array arranged in an L shape.The center-to-center distance between two adjacent elements is 0.54k0 for both the Tx and Rx arrays,where k0 is the free-space wavelength at 27 GHz.The proposed AFDBF array possesses a more compact structure and lower system hardware cost and power consumption compared with conventional brick-type full-digital arrays.In addition,the energy efficiency of the proposed AFDBF array outperforms that of a hybrid beamforming array.The measurement results indicate that the operating frequency band of the proposed array is 24.25–29.50 GHz.An eight-element linear array within the Tx array can achieve a scanning angle ranging from-47°to+47°in both the azimuth and the elevation planes,and the measured scanning range of each eight-element Rx array is–45°to+45°.The measured maximum effective isotropic radiated power(EIRP)of the eight-element Tx array is 43.2 dBm at 28.0 GHz(considering the saturation point).Furthermore,the measured error vector magnitude(EVM)is less than 3%when 64-quadrature amplitude modulation(QAM)waveforms are used.

Gut microbiota affects the estrus return of sows by regulating the metabolism of sex steroid hormones

Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.Results In this study,we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows.Using metagenomic sequencing data from 85 fecal samples,we identified 37 bacterial species that were significantly associated with estrus return.Normally returning sows were characterized by increased abundances of L.reuteri and P.copri and decreased abundances of B.fragilis,S.suis,and B.pseudolongum.The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome.The results were confirmed in a validation cohort.Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis.An integrated analysis of differential bacterial species,metagenome,and fecal metabolome provided evidence that normal return-associated bacterial species L.reuteri and Prevotella spp.participated in the degradation of pregnenolone,progesterone,and testosterone,thereby promoting estrogen biosynthesis.Furthermore,the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.Conclusions An integrated analysis of differentially abundant bacterial species,metagenome,and fecal metabolome revealed the involvement of L.reuteri and Prevotella spp.in sow estrus return.These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones,suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning.

Study on the Application of Refined Nursing Care in The Care for Elderly Patients with Reflux Esophagitis

Objective: To investigate the application effect of refined nursing care in the care for elderly patients with reflux esophagitis. Methods: Following the difference in nursing style, 84 cases of elderly patients with reflux esophagitis admitted to our hospital from May 2022 to May 2023 were randomly grouped into a control group and a research group, with 42 cases each. The control group was given conventional nursing care and the research group was given refined nursing care. The psychological state and treatment adherence of the two groups of patients after the nursing intervention were compared. Results: After the nursing intervention, the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores of the research group were lower than those of the control group (P < 0.05). The treatment compliance of the research group was better than the control group (P < 0.05). Conclusion: The implementation of refined nursing care for elderly patients with reflux esophagitis exhibited a significant effect on improving the patient’s psychological state, treatment compliance, and rehabilitation.

Intraspecific floral colour variation in three Pedicularis species

Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours.

KLF4 Inhibits the Activation of Human Hepatic Stellate Cell In Vitro

Objective Hepatic stellate cells(HSCs)play a crucial role in liver fibrosis.Early-stage liver fibrosis is reversible and intimately associated with the state of HSCs.Kruppel-like factor 4(KLF4)plays a pivotal role in a wide array of physiological and pathological processes.This study aimed to investigate the effect of KLF4 on the proliferation,apoptosis and phenotype of quiescent HSCs Methods We designed a KLF4 lentiviral vector and a KLF4 siRNA lentiviral vector,to upregulate and silence KLF4 expression in human HSC LX-2 cells via transfection.Cell proliferation was assessed using the CCK-8 assay.Flow cytometry was used to detect the cell cycle distribution and apoptosis rate.Western blotting was used to determine the levels of some quiescence and activation markers of HSCs Results Overexpression of KLF4 significantly increased the levels of E-cadherin and ZO-1,which are quiescent HSC markers,while significantly decreased the levels of N-cadherin and a-SMA,known activated HSC markers.In contrast,cell proliferation and apoptosis rates were elevated in LX-2 cells in which KLF4 expression was silenced Conclusion KLF4 inhibits the proliferation and activation of human LX-2 HSCs.It might be a key regulatory protein in the maintenance of HSC quiescence and may serve as a target for the inhibition of hepatic fibrosis.

Multi-objective optimization design of anti-roll torsion bar using improved beluga whale optimization algorithm

Purpose – This study aims to reduce the redundant weight of the anti-roll torsion bar brought by thetraditional empirical design and improving its strength and stiffness.Design/methodology/approach – Based on the finite element approach coupled with the improved belugawhale optimization (IBWO) algorithm, a collaborative optimization method is suggested to optimize the designof the anti-roll torsion bar structure and weight. The dimensions and material properties of the torsion bar weredefined as random variables, and the torsion bar’s mass and strength were investigated using finite elements.Then, chaotic mapping and differential evolution (DE) operators are introduced to improve the beluga whaleoptimization (BWO) algorithm and run case studies.Findings – The findings demonstrate that the IBWO has superior solution set distribution uniformity,convergence speed, solution correctness and stability than the BWO. The IBWO algorithm is used to optimizethe anti-roll torsion bar design. The error between the optimization and finite element simulation results wasless than 1%. The weight of the optimized anti-roll torsion bar was lessened by 4%, the maximum stress wasreduced by 35% and the stiffness was increased by 1.9%.Originality/value – The study provides a methodological reference for the simulation optimization process ofthe lateral anti-roll torsion bar.

Analysis of the Effect of Humanistic Care in the Process of Pre-Hospital Emergency Care

Objective:To explore the effectiveness of humanistic care in pre-hospital emergency care.Methods:From April 2020 to January 2021,80 pre-hospital emergency patients were studied.The patients were randomly divided into two groups:a control group(n=40),which received conventional care,and an experimental group(n=40),which received humanistic care.The effects of nursing care and psychological state were compared between the two groups.Results:The experimental group showed better nursing outcomes and a more positive psychological state compared to the control group(P<0.05).Conclusion:Humanistic care in pre-hospital emergency settings is more effective in reducing patients’anxiety and depression,enhancing the operational abilities and service attitudes of nursing staff,and increasing the emergency success rate.

A Study on the Application of Evidence-Based Nursing in The Care of Patients with Severe Acute Pancreatitis

Objective: To explore the application research of evidence-based nursing in the care of patients with severe acute pancreatitis. Methods: This study focuses on evidence-based nursing care of severe acute pancreatitis. Patients with severe acute pancreatitis who received treatment in our hospital were selected, from which 80 cases were chosen for detailed analysis. The patients were randomly grouped into a control group (conventional nursing care) and a study group (evidence-based nursing care), with 40 patients each. Relevant research data were recorded during the nursing process, analyzed, and used as research indicators. Results: The hospitalization time and morbidity and mortality rate of the research group were shorter than those of the control group, and the recovery rate was higher than that of the control group (P < 0.05). Patient satisfaction with nursing care in the observation group was higher than in the control group (P < 0.05). Conclusion: For patients with severe acute pancreatitis, the use of evidence-based nursing methods effectively reduced the patient’s mortality rate, improved its curative effect, and also shortened the patient’s hospitalization time.

Application Effect of Staged Health Education in the Nursing Care of Patients with Upper Gastrointestinal Bleeding

Objective:To investigate the application effect of staged health education in the care of patients with upper gastrointestinal bleeding.Methods:This study takes health education in the care of patients with upper gastrointestinal bleeding as the main direction.160 patients with upper gastrointestinal bleeding who received treatment in our hospital were selected as samples,and the grouping software was used to divide them into the reference group and the study group,with 80 patients each.The reference group and the study group used routine health education and staged health education respectively.Relevant research data were recorded during the nursing process,analyzed,and used as research indicators.Results:The compliance behavior of the study group was higher than that of the reference group after the staged nursing care,and at the same time,the nursing care satisfaction of the study group was higher than that of the reference group(P<0.05).Conclusion:The use of staged health education for the care of patients with upper gastrointestinal bleeding not only enhances the degree of patient awareness and compliance but also improves nursing satisfaction,which is worthy of promotion and application.

耦合修正分析Al−Fe−Ni合金蠕变机理

在引入阈值应力和载荷传递系数后,对Al−Fe−Ni合金的蠕变本构方程进行耦合修正,描述该合金在300和400℃下的位错蠕变。量化结果分析及显微组织表征表明,蠕变过程中位错与共晶相间复杂交互作用是阈值应力的起源。同时,共晶相与基体之间模量的差异引起共晶相分担应力作用。此外,温度对基体及共晶相模量产生的影响差异导致高温时合金阈值应力降低,而应力转移系数增大。这些现象通过有限元模型分析得到进一步的论证。总体而言,共晶合金位错蠕变的控制机理得到了更深层次的量化认识。

原位TiB_(2)颗粒增强7075铝基复合材料在不同应力状态下的韧性断裂行为

采用力学试验、微观表征和数值模拟研究原位TiB_(2)颗粒增强7075铝基复合材料在不同应力状态下的断裂行为。设计4组拉伸试样、1组剪切试样和1组压缩试样,并对这6组试样进行力学实验。通过原位应变测试和有限元模拟研究6组试样在变形过程中的应变分布。对6组试样的断口形貌进行表征,分析其在不同应力状态下的损伤演化机制。研究发现:该材料的主要断裂机制为界面脱粘和颗粒断裂,表现为高应力三轴度下的拉伸断裂和低应力三轴度下的剪切断裂。在拉伸断裂条件下,形核空洞的体积在最大主应力的作用下增大;在剪切断裂条件下,空洞的形状在最大剪应力作用下变化明显,而体积变化不明显。基于实验揭示的断裂机理,提出一种考虑最大主应力和最大剪应力的韧性断裂准则,该准则可以预测该复合材料在不同应力状态下的断裂曲面。与改进的Mohr−Coulomb、Lou−Yoon−Huh、Hu和Mu模型的对比分析表明,新模型能更准确地预测铝基复合材料的韧性断裂行为。

An Optimal Control-Based Distributed Reinforcement Learning Framework for A Class of Non-Convex Objective Functionals of the Multi-Agent Network

This paper studies a novel distributed optimization problem that aims to minimize the sum of the non-convex objective functionals of the multi-agent network under privacy protection, which means that the local objective of each agent is unknown to others. The above problem involves complexity simultaneously in the time and space aspects. Yet existing works about distributed optimization mainly consider privacy protection in the space aspect where the decision variable is a vector with finite dimensions. In contrast, when the time aspect is considered in this paper, the decision variable is a continuous function concerning time. Hence, the minimization of the overall functional belongs to the calculus of variations. Traditional works usually aim to seek the optimal decision function. Due to privacy protection and non-convexity, the Euler-Lagrange equation of the proposed problem is a complicated partial differential equation.Hence, we seek the optimal decision derivative function rather than the decision function. This manner can be regarded as seeking the control input for an optimal control problem, for which we propose a centralized reinforcement learning(RL) framework. In the space aspect, we further present a distributed reinforcement learning framework to deal with the impact of privacy protection. Finally, rigorous theoretical analysis and simulation validate the effectiveness of our framework.

Analysis of electromagnetic characteristics of typical faults in permanent magnet wind generators

Due to the harsh actual operating environment of the permanent magnet wind turbine,it is easy to break down and difficult to monitor.Therefore,the electromagnetic characteristics identification of major fault types of large-scale permanent magnet wind turbines is studied in this paper.The typical faults of rotor eccentricity,stator winding short circuit and permanent magnet demagnetization of permanent magnet wind turbines are analyzed theoretically.The wavelet analysis algorithm is used to decompose and reconstruct the abnormal electromagnetic signal waveform band,and the characteristic frequency of the electromagnetic signal is obtained when the fault occurs.In order to verify the effectiveness of the proposed method,a 3.680MW permanent magnet wind turbine was taken as the research object.Its physical simulation model was established,and an external circuit was built to carry out field co-simulation.The results show that the motor fault type can be determined by detecting the change rule of fault characteristic frequency in the spectrum diagram,and the electromagnetic characteristic analysis can be applied to the early monitoring of the permanent magnet wind turbine fault.

Historical development of karst evergreen broadleaved forests in East Asia has shaped the evolution of a hemiparasitic genus Brandisia(Orobanchaceae)

Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal.

New Technology of Multidirectional Loading Rotary Extrusion

To satisfy the requirements for the precise formation of large-scale high-performance lightweight components with inner ring reinforcement, a new multidirectional loading rotary extrusion forming technology is developed to match the linear motion with the rotary motion and actively increases the strong shear force. Its principle is that the radial force and rotating torque increase when the blank is axially extruded and loaded. Through the synergistic action of axial, radial, and rotating motions, the orderly fow of metal is controlled, and the cumulative severe plastic deformation (SPD) of an“uplift-trowel” micro-area is generated. Consequently, materials are uniformly strengthened and toughened. Simultaneously, through the continuous deformation of a punch “ellipse-circle,” a high reinforcement component is grown on the cylinder wall to achieve the high-quality formation of cylindrical parts or the inner-ring-reinforcement components. Additionally, the efective strain increases with rotation speed, and the maximum intensity on the basal plane decreases as the number of revolutions increase. The punch structure also afects the axial extrusion loading and equivalent plastic strain. Thus, the proposed technology enriches the plastic forming theory and widens the application feld of plastic forming. Furthermore, the formed large-scale high-performance inner-ring-stifened magnesium components have been successfully verifed in aerospace equipment, thereby solving the problems of integral forming and severe deformation strengthening and toughening. The developed technology has good prospects for mass production and application.

Design and analysis of a high loss density motor cooling system with water cold plates

Aiming at reducing the difficulty of cooling the interior of high-density motors,this study proposed the placement of a water cold plate cooling structure between the axial laminations of the motor stator.The effect of the cooling water flow,thickness of the plate,and motor loss density on the cooling effect of the water cold plate were studied.To compare the cooling performance of water cold plate and outer spiral water jacket cooling structures,a high-speed permanent magnet motor with a high loss density was used to establish two motor models with the two cooling structures.Consequently,the cooling effects of the two models were analyzed using the finite element method under the same loss density,coolant flow,and main dimensions.The results were as follows.(1)The maximum and average temperatures of the water cold plate structure were reduced by 25.5%and 30.5%,respectively,compared to that of the outer spiral water jacket motor;(2)Compared with the outer spiral water jacket structure,the water cold plate structure can reduce the overall mass and volume of the motor.Considering a 100 kW high-speed permanent magnet motor as an example,a water cold plate cooling system was designed,and the temperature distribution is analyzed,with the result indicating that the cooling structure satisfied the cooling requirements of the high loss density motor.

用微观发生法培养幼儿科学创造力的实验研究

本研究首先探讨了科学创造力的结构模型,然后根据这一结构模型和微观发生法的特点设计了幼儿科学创造力培养的具体方案,并在广州市一所幼儿园进行了为期一年的实验。实验结果表明,不管是从教师评价和家长评价来看,还是从幼儿自身的能力测验来看,实验班幼儿的科学创造力都得到了很大的发展。

使用微观发生法促进儿童的认知发展

微观发生法是研究儿童认知发展的一种新的方法,本文在简要介绍微观发生法的主要特征的基础上,着重探讨了在教学实践中如何使用微观发生法促进儿童的认知发展。结合国内外相关的研究成果,主要从教学活动实施的基本要求、教学活动安排的整体原则和教学活动实施的具体环节三个方面对有关问题进行了详细的阐述。

国外儿童科学思维发展的新探索

儿童科学思维是发展心理学研究领域的重要的研究课题。最近十年,儿童科学思维发展的研究经历了显著的变化。文章对儿童科学思维发展的研究进行简要回顾,主要阐述有关儿童科学思维发展的特殊领域知识、一般领域策略、概念和策略的整合模型以及微观发生法,并在此基础上,对儿童科学思维发展研究进行简单的评价和展望。

国外儿童认知发展与学习的最新研究述评

认知发展变化是儿童发展研究的中心课题,而儿童学习是研究儿童认知发展变化的一个重要方面。20世纪90年代以来,随着儿童学习重新研究,儿童认知发展研究取得显著进展。本文在最新儿童认知发展和学习研究的基础上,概述儿童早期认知能力的新发现以及儿童学习的有关研究和结论,并提出了新的研究框架。