Refiector Deformation Measurement and Correction Methodology of Large Antenna Based on Phased Array Feed

To solve the problem of time-consuming measurement and correction of large antennas’reflector deformation,a new microwave holography methodology based on a Phased Array Feed(PAF)is proposed.Starting from the known expression of receiving signals in microwave holography,the theory of PAF holography is derived through Geometrical Optics.Reflector deformation,as well as pointing deviation and subreflector offset,can be calculated out by applying the derived equations.A measurement and correction system based on PAF holography is depicted,and two kinds of measurement methods are illustrated.The proposed measurement methodology is verified by numerical simulation,and its measurement error is analyzed.The results indicate that our proposed methodology is feasible,especially for Cassegrain antennas.

Recombinant chitinase-3-like protein 1 alleviates learning and memory impairments via M2 microglia polarization in postoperative cognitive dysfunction mice

Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.

推荐一个无机合成综合实验——基于废弃大豆油的微乳液法制备纳米氧化锌

纳米氧化锌是一类多功能纳米材料,由于其优秀的物理化学性质而被广泛应用于多个领域。传统的合成方法存在成本过高、过程复杂、产物不稳定等问题。微乳合成法具有操作简单,成本低廉,产物尺寸可控等优点,可以有效避免传统合成方法的缺陷。特别是将废弃大豆油合成的乳化剂应用在合成的过程中,可以实现废物的回收再利用,又能满足绿色化学和可持续发展的要求。使用X射线衍射(XRD)、扫描电镜(SEM)、化学分析等多种方法对产物纳米氧化锌的形貌和性质进行了表征,实现了无机合成-化学分析-仪器分析的综合偶联,从而达到提升大学生进行综合实验能力的目的。

Data processing and initial results of Chang'e-3 lunar penetrating radar

To improve our understanding of the formation and evolution of the Moon, one of the payloads onboard the Chang＇e-3 （CE-3） rover is Lunar Penetrating Radar （LPR）. This investigation is the first attempt to explore the lunar subsurface structure by using ground penetrating radar with high resolution. We have probed the subsur- face to a depth of several hundred meters using LPR. In-orbit testing, data processing and the preliminary results are presented. These observations have revealed the con- figuration of regolith where the thickness of regolith varies from about 4 m to 6 m. In addition, one layer of lunar rock, which is about 330 m deep and might have been accumulated during the depositional hiatus of mare basalts, was detected.

Data preprocessing and preliminary results of the Moon-based Ultraviolet Telescope on the CE-3 lander

The Moon-based Ultraviolet Telescope （MUVT） is one of the payloads on the Chang＇e-3 （CE-3） lunar lander. Because of the advantages of having no at- mospheric disturbances and the slow rotation of the Moon, we can make long-term continuous observations of a series of important celestial objects in the near ultra- violet band （245-340 nm）, and perform a sky survey of selected areas, which can- not be completed on Earth. We can find characteristic changes in celestial brightness with time by analyzing image data from the MUVT, and deduce the radiation mech- anism and physical properties of these celestial objects after comparing with a phys- ical model. In order to explain the scientific purposes of MUVT, this article analyzes the preprocessing of MUVT image data and makes a preliminary evaluation of data quality. The results demonstrate that the methods used for data collection and prepro- cessing are effective, and the Level 2A and 2B image data satisfy the requirements of follow-up scientific researches.

Performance evaluation of lunar penetrating radar onboard the rover of CE-3 probe based on results from ground experiments

Lunar Penetrating Radar （LPR） onboard the rover that is part of the Chang＇e-3 （CE-3） mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetra- tion depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm.

The New Wuqing 70 m Radio Telescope and Measurements of Main Electronic Properties in the X-band

The new Wuqing 70 m radio telescope is first used for the downlink data reception in the first Mars exploration mission of China,and will be used for the other deep space communications and radio astronomical observations in the future.The main specifications and measurement results of some properties in the X-band are introduced in this paper,such as pointing calibration,gain and efficiency,system noise temperature,system equivalent flux density,and variations with elevation.The 23 parameters pointing calibration model considering the atmospheric refraction correction in real time is presented in the telescope,and the pointing accuracy reaches 570 in azimuth direction and 607 in elevation direction for different weather conditions.More than 62%efficiencies are achieved at full elevation range,and more than 70%in the mid-elevation.The system equivalent flux density of the X-band in the mid-elevation reaches 26 Jy.

Data processing and initial results from the CE-3 Extreme Ultraviolet Camera

The Extreme Ultraviolet Camera （EUVC） onboard the Chang＇e-3 （CE-3） lander is used to observe the structure and dynamics of Earth＇s plasmasphere from the Moon. By detecting the resonance line emission of helium ions （He＋） at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius （RE） in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plas- masphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies.

TyG指数、血压、血糖相关指标与单纯性超重/肥胖患者早期肾功能损伤的关系

目的:探讨TyG指数、血压、血糖相关指标与单纯性超重/肥胖患者早期肾功能损伤(ERFI)的关系及交互作用。方法:选取2017年1月至2021年12月于郑州大学第一附属医院体检的BMI≥24 kg/m 2者3956例为研究对象,按尿白蛋白与肌酐比值(UACR)分组,<3 mg/mmol为对照组(n=3844),3~≤30 mg/mmol为ERFI组(n=112)。采用Logistic回归分析甘油三酯葡萄糖(TyG)指数、血压和糖化血红蛋白(HbA1c)与ERFI的关联,并进一步分析各因素的交互作用。结果:ERFI组的BMI、收缩压(SBP)、舒张压(DBP)、空腹血糖(FPG)、HbA1c、总胆固醇(TG)、TyG指数高于对照组,HDL-C低于对照组(P<0.05)。TyG指数>8.77(OR=2.138,95%CI:1.411~3.240)、正常血压高值(OR=2.450,95%CI:1.652~3.635)和HbA1c 5.61%~<7.00%(OR=1.510,95%CI:1.024~2.226)是单纯性超重/肥胖患者ERFI的危险因素。TyG指数与血压有交互作用(RERI=1.754,95%CI:-0.126~3.636;APAB=0.405,95%CI:0.068~0.741)。结论:TyG指数≥8.77、正常血压高值和HbA1c 5.61%~<7.00%可增加单纯性超重/肥胖患者ERFI的患病风险,且血压与TyG指数存在交互作用。

教育数字化背景下国家级化学实验教学示范中心建设与实践

大连理工大学化学国家级实验教学示范中心秉承“注重基础、培养能力、塑造人格”的育人宗旨、以学生发展为中心的育人理念,充分发挥人才培养的主战场作用,在实验教学体系构建、教学资源建设、实验室管理与师资队伍建设等方面进行了深层次的探索与研究。经过5年的建设实践,构建了“四位一体”的实验教学体系和“一体化”的安全教育新范式,打造了“系列化、数字化、多模态”的实验教学资源,建成了一流的实验室环境和制度保障,形成了“名师化”引领的实验教学团队,促进了学生自主探究、创新实践、防护应急处理等方面能力的提升。

乙二胺四乙酸铁钠补铁剂制备实验改进

本项目将乙二胺四乙酸铁钠(NaFeEDTA)补铁剂制备实验项目进行了改进,将理论知识与实际生产紧密衔接,依据药物制备工艺流程,设置集方案设计、药物制备、结构鉴定、纯度分析等模块于一体的全链条实验内容,将实验项目由验证性实验转变为综合性、设计性实验,引导学生结合制药工艺流程中所涉及到的质量控制、安全生产、环境保护等因素设计实验方案。本实验项目可结合多条专利路线,能激发学生探究兴趣,促进学生自主探究,培养学生方案设计和创新思辨能力,提升学生解决实际问题能力和科学素养,增强专业自信。

正常低密度脂蛋白胆固醇人群残余胆固醇与颈部动脉粥样硬化斑块的关联分析

目的:分析残余胆固醇(RC)与正常低密度脂蛋白胆固醇人群颈部动脉粥样硬化斑块患病风险的关联。方法:选择2016年9月至2023年6月体检的正常低密度脂蛋白胆固醇者7152人,依据RC分为低、高RC组,绘制Kaplan-Meier风险曲线,并通过Log-rank检验进行比较,采用Cox比例风险模型分析颈部动脉粥样硬化斑块的危险因素,采用限制性立方样条回归分析RC与颈部动脉粥样硬化斑块发生风险的关系。结果:Cox回归分析显示年龄、性别、RC、糖化血红蛋白为颈部动脉粥样硬化斑块的影响因素,HR(95%CI)分别为1.041(1.037~1.046)、1.153(1.042~1.276)、1.123(1.023~1.233)、1.088(1.024~1.156);RC水平与颈部动脉粥样硬化斑块发生风险有关(P=0.033),随RC增高,患病风险呈先逐渐增高再平稳趋势。结论:RC升高可增加正常低密度脂蛋白胆固醇人群颈部动脉粥样硬化斑块发生风险。

基于多重机制优化YOLOv8的复杂环境下安全帽检测方法

为了解决建筑工地、隧道、煤矿等施工场景中现有安全帽检测算法对于小目标、密集目标以及复杂环境下的检测精度低的问题,提出了一种基于多重机制的安全帽检测方法。以YOLOv8n为基础将Backbone部分的C2f模块加入可扩张残差(DWR)注意力模块,使得网络能够更灵活地适应不同尺度的特征,以而更准确地识别图像中的物体;采用可变形卷积AKConv模块取代主干部分中的原始Conv,为卷积神经网络带来了显著的性能提升,从而实现更高效的特征提取。此外引用了大型可分离核注意力LSKA模块与SPPF结构相结合,大大增强了模型核心的融合能力。在Safety helmet数据集的实验结果表明,改进后的算法相较于原模型,mAP@0.5指标上提升了10.5个百分点,在mAP@0.5-0.95指标上提升了3.7个百分点,能有效提高复杂场景下的安全帽佩戴检测精度。

学思践悟培育科学素养,知行合一发挥“慧眼”专长——分析化学实验课程思政建设

针对化学实验教学过程中所存在的思政要素与专业知识融入不够而导致的学生职业使命感和价值观薄弱问题,分析化学实验课程将思政元素有机融入到实验内容中,制定了知识、能力、素质有机融合的“三位一体”育人目标,建设了“六聚焦”的思政案例库,实施了“七融进”的课程思政教学举措,创新了“五联动”的思政育人设计,打造了有深度、有温度的挑战性课堂,与学生进行知识的对话、思维的对话和心灵的对话。

基于滑模观测器的高速PMSM无传感器控制

针对基于饱和函数滑模观测器方法存在调节参数多及低通滤波器带来的相位延迟问题,研究一种基于超螺旋算法的滑模观测器无传感器控制策略,通过理论推导及系统稳定性分析,设计了一种滑模系数根据转速变化在线调节的自适应滑模系数算法。通过实验验证了该方法相比于基于饱和函数滑模观测器,能在较宽速度范围内有效地抑制抖振,提高了无传感器控制系统的估计精度,简化了参数调节过程及滤波器设计环节。

A New Method of Frequency Fluctuation Estimation and IPS Processing Results Based on the Downlink Signal of Tianwen-1

The radio-occultation observations taken by Tianwen-1 are aiming to study the properties of solar wind.A new method of frequency fluctuation(FF)estimation is presented for processing the down-link signals of Tianwen-1 during the occultation period to study the properties of the coronal plasma at the heliocentric distances of 4.48–19 R_(⊙).Because of low S/N as well as the phase fluctuation phenomena caused by solar activity,a Kalman based on polynomial prediction methods is proposed to avoid the phase locked loop loss lock.A new detrend method based on multi-level iteration correction is proposed to estimate Doppler shift to get more accurate power density spectra of FF in the low frequency region.The data analyze procedure is used to get the properties of the solar corona during the occultation.The method was finally verified at the point when the solar offset is 5.7 R_(⊙),frequency tracking was successfully performed on data with a carrier-to-noise ratio of about 28 dBHz.The density spectra obtained by the improved method are basically the same when the frequency is greater than 2 mHz,the uncertainty in the result of the rms of the FF obtained by removing the trend term with different order polynomials is less than 3.3%.The data without eliminating interference show a large error for different detrending orders,which justifies the need for an improved approach.Finally,the frequency fluctuation results combined with the information on intensity fluctuation obtained by the new method are compared with the results of the integrated Space Weather Analysis system and theoretical formula,which verifies that the processing results in this paper have a certain degree of credibility.

基于血清学指标构建H型高血压患者MACE发生风险预测模型

目的探讨H型高血压患者不良心血管事件(MACE)发生的危险因素,并构建H型高血压患者MACE发生风险预测模型。方法选取2019年1月至2022年11月该院收治的375例H型高血压患者作为研究对象,根据是否发生MACE分为MACE组(41例)和非MACE组(334例)。收集两组临床资料,采用多因素Logistic回归分析H型高血压患者发生MACE的危险因素。构建H型高血压患者MACE发生风险的列线图预测模型,以C-index量化模型预测性能,并绘制校准曲线评价列线图预测模型的校准度及鉴别效度,绘制决策曲线分析列线图预测模型的临床净受益。结果MACE组高血压病程、同型半胱氨酸(Hcy)、尿酸(UA)、Toll样受体(TLR4)水平及靶器官损害数目>2个的患者比例、高血压分级为3级的患者比例、入院当日收缩压(SBP)、入院当日舒张压(DBP)、夜间平均SBP、夜间平均DBP均高于非MACE组,高分子量脂联素(HMW-ADP)水平低于非MACE组,差异均有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,夜间平均SBP、Hcy、TLR4水平升高及HMW-ADP水平降低均是H型高血压患者发生MACE的危险因素(P<0.05)。列线图预测模型预测H型高血压患者MACE发生风险的C-index为0.821(95%CI:0.712~0.896)。决策曲线分析结果显示,当列线图预测模型预测值为0.75~0.80时,可提供附加临床获益。结论基于Hcy、TLR4、HMW-ADP、夜间平均SBP构建H型高血压患者MACE发生风险的列线图预测模型具有良好预测效果,适合在临床工作中推广应用。

基于机器学习算法的胃癌淋巴结转移预测模型研究

目的基于4种机器学习(ML)算法构建胃癌淋巴结转移的预测模型并验证。方法回顾性收集531例胃癌根治术患者的临床资料,按3∶1比例将患者随机分为训练集399例和测试集132例。通过单因素分析筛选胃癌淋巴结转移的特征选择变量,分别建立逻辑回归、随机森林、K-邻近算法、支持向量机算法模型并进行变量重要性排序。将所有ML算法模型在测试集中进行验证,绘制受试者工作特征(ROC)曲线,基于曲线下面积(AUC)、灵敏度、特异度、准确度确定最优ML算法模型。基于最优ML算法模型的变量重要性排序构建列线图模型,通过ROC曲线、校准曲线、决策曲线评价列线图模型的区分能力、校准能力和临床适用性。结果4种ML算法模型比较结果显示,随机森林模型为最优算法模型,其在训练集中的准确度、灵敏度、特异度分别为72.7%、69.9%、75.0%,AUC为0.803,其在测试集中的准确度、灵敏度、特异度分别为64.4%、66.7%、62.5%,AUC为0.751。基于随机森林算法模型的变量构建列线图模型,ROC曲线显示列线图模型在训练集、测试集中的AUC分别为0.721、0.776,校准曲线和决策曲线显示列线图模型在训练集与测试集中均有较好的校准能力和临床适用性。结论随机森林模型是4种ML算法模型中的最优算法模型,基于随机森林模型构建的列线图模型能够较准确地预测胃癌淋巴结转移风险,从而更好地指导临床诊断和治疗决策。

托里消毒散通过调控NF-κB信号通路对大鼠皮瓣缺血再灌注损伤的影响

目的探讨托里消毒散对大鼠皮瓣缺血再灌注损伤的影响及其潜在机制。方法大鼠随机分为假手术组(Sham组)、模型组(Model组)、托里消毒散高剂量组(MDX-H组)和托里消毒散低剂量组(MDX-L组),每组10只。大鼠背部皮瓣模型构建成功后,立即给予药物灌胃处理,每日1次,连续14 d。观察术后各组大鼠皮瓣变化情况,并于术后第14天测定各组大鼠皮瓣成活率;HE染色观察大鼠皮瓣组织病理学变化;Western blot检测大鼠皮瓣组织p-p65和p-IκBα蛋白表达;ELISA法检测TNF-α、IL-1β、IL-6细胞因子的表达情况;通过Ki67和CD31免疫组化染色观察表皮基底层细胞增殖及血管再生情况。结果与Model组相比,MDX-H组与MDX-L组术后14 d出现少量水肿,有少量炎性液体渗出,脱痂时间提前,皮瓣缺血坏死情况得到明显改善,皮瓣坏死面积显著减少,大鼠皮瓣成活率明显提高(P<0.01)。此外,托里消毒散可明显改善大鼠背部皮瓣缺血再灌注损伤组织病理形态,降低p-p65和p-IκBα蛋白表达(P<0.001),降低血清中TNF-α、IL-1β、IL-6炎性因子水平(P<0.05,P<0.01,P<0.001,P<0.0001)。Ki67和CD31的差异也提示托里消毒散治疗加快了缺血皮瓣损伤后的再上皮化和血管的形成。结论托里消毒散通过调控NF-κB信号通路、加速上皮化和血管生成,发挥改善皮瓣缺血再灌注损伤的作用。

杉木全同胞家系生长与木材基本密度性状的变异及选择

【目的】创制新优杉木种质材料,进而筛选速生优质家系,推进杉木高世代育种进程。【方法】以杉木第二代改良种子园10个骨干亲本作为杂交亲本,采用人工控制授粉方式获得30个全同胞家系,并进行多地点全同胞子代测定,分析其8年生杉木的生长和木材基本密度遗传变异规律,进而开展优良家系选择。【结果】家系间树高、胸径(DBH)、单株材积和木材基本密度(WBD)存在广泛遗传变异,差异达显著(P<0.05)或极显著水平(P<0.01),其中单株材积变异较大,各地点表型变异系数和遗传变异系数分别达到21.56%~28.53%、12.18%~19.64%。树高、胸径、单株材积和木材基本密度家系遗传力分别为0.1594、0.2232、0.1799和0.5357,有利于家系选择。利用BLUP方法估算全同胞家系亲本生长和木材基本密度育种值,同时按亲本模型估算各杂交组合的特殊配合力(SCA)并进行排名,综合生长性状和木材基本密度表现,选获速生优质型家系2个(家系5和29)。其中,家系5具有更高的生长和材质增益,相比群体均值其树高、胸径、单株材积及木材基本密度增益平均为6.02%、8.21%、15.82%、7.25%,而相比对照(2.5代种子园混合种)增益平均为26.47%、14.25%、34.56%、5.35%,因此,家系5是更理想的速生优质家系。【结论】30个杉木全同胞家系的生长和木材基本密度存在丰富的遗传变异,筛选获得的家系可作为候选杉木速生优质良种。