Effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope

The alidade’s non-uniform temperature field of a large radio telescope is very obvious under solar radiation.Estimating a radio telescope’s pointing errors,caused by the alidade deformation under solar radiation,is significant to improve the telescope’s pointing accuracy.To study the effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope,a temperature experiment is first carried out in a 70-m radio telescope on a sunny day.According to the measured results,the temperature distribution rule of the alidade is summarized initially.In addition,the alidade’s temperature field is calculated by finite element thermal analysis.The simulated results are proved to be in good agreement with the experimental results.Finally,the alidade deformation under solar radiation is computed by finite element thermalstructure coupling analysis.The telescope’s pointing errors caused by alidade deformation are estimated via the alidade’s node displacements.The final results show that the effect of alidade thermal behavior on the telescope’s elevation pointing errorsΔε2+Δεr is much more than the effect on the telescope’s crosselevation pointing errorsΔε1.The maximum ofΔε2+Δεr is more than 45″,while the maximum ofΔε1 is less than 6″.This study can provide valuable references for improving the pointing accuracy of large radio telescopes.

DRG点数法下医疗机构冲点行为及其潜在风险探究

随着疾病诊断相关分组(DRG)点数法在我国的广泛实施,点数法下医疗机构冲点行为带来的潜在风险是急需解决的现实问题。通过阐述DRG点数法下医保基金分配不确定的特殊性并基于理性经济人视角、委托代理理论和同群效应,从理论层面探究了DRG点数法下医疗机构冲点行为的可能性、可行性与扩散性。针对理论模型,采用博弈论进一步构建DRG点数法下医疗机构冲点行为模型,剖析了冲点行为缘由及其潜在风险。研究认为可以通过加强医联体与分级诊疗制度下医疗机构间的沟通合作、落实医保部门对医疗机构的监管机制预防冲点行为带来的潜在风险。

一类Pointaré差分方程解的渐近性质

以二阶的情形讨论了Ｐｏｉｎｃａｒ差分方程ｙ（ｎ＋ｍ）十（ａ１＋ｐ１（ｍ））ｙ（ｎ＋ｍ－１）＋…＋（ａｎ＋ｐｎ（ｍ））ｙ（ｍ）＝０当其常系数部分ｘ（ｎ＋ｍ）＋ａ１ｘ（ｎ＋ｍ－１）＋…＋ａｎｘ（ｍ）＝０的特征方程有相同的根时，解的渐近性质．通过不动点方法给出了Ｐｏｉｎｃａｒ差分方程的解渐近于其常系数方程解的条件，并给出了渐近式高阶项的估计．

ASYMPTOTIC BEHAVIOR OF LINEAR ADVANCED DIFFERENTIAL EQUATIONS

In this article, we consider a general class of linear advanced differential equa- tions, and obtain explicitly sufficient conditions of convergence and exponential convergence to zero. A necessary condition is provided as well.

Investigation of Surface Micro Waviness in Single Point Diamond Fly Cutting

Single point diamond fly cutting is widely used in the manufacture of large-aperture ultra-precision optical elements. However,some micro waviness( amplitude about 30 nm,wavelength about 15 mm) along the cutting direction which will decrease the quality of the optical elements can always be found in the processed surface,and the axial vibration of the spindle caused by the cut-in process is speculated as the immediate cause of this waviness. In this paper,the analytical method of dynamic mesh is applied for simulating the dynamic behavior of the vertical spindle. The consequence is then exerted to the fly cutter and the processed surface profile is simulated. The wavelength of the simulation result coincides well with the experimental result which proves the importance of the cut-in process during the single point diamond fly cutting.

Rheological behavior during thermotropic gelation of polyacrylonitrile concentrated solutions

Dynamic viscoelastic properties of polyacrylonitrile(PAN)/DMSO/H2O solutions with different H2O contents were studied as a function of temperature.These PAN solutions gradually became gel with decreasing temperature.The sol-gel transition took place at a critical gel temperature,at which the scaling law of G'(ω)～G″(ω)∝ωn held,allowing an accurate determination of the critical gel temperature by means of the frequency independence of the loss tangent.The gel point of PAN solutions increases with increasing H2O content.The scaling exponent n(=0.86) at the gel point is confirmed to be universal for PAN gels,which is independent of temperature,suggesting the similarity of the fractal structure in the critical PAN gels.

L^∞-Asymptotic Behavior of the Variational Inequality Related to American Options Problem

We study the approximation of variational inequality related to American options problem. A simple proof to asymptotic behavior is also given using the theta time scheme combined with a finite element spatial approximation in uniform norm, which enables us to locate free boundary in practice.

Effect of nanocomposite pour point depressant EVAL/CNT on flow properties of waxy crude oil

The nanocomposite EVAL-CNT was produced by chemical grafting in the solution system through the esterification of ethylene-vinyl alcohol copolymer (EVAL) and carboxylated multi-walled carbon nanotubes (O-MWCNT), and its structural properties were characterized. The improvement of the rheological properties of the waxy oil system by the novel pour point depressant was investigated using macroscopic rheological measurements and microscopic observations. The results showed that EVAL-CNT nanocomposite pour point depressant (PPD) could significantly reduce the pour point and improve the low temperature fluidity of crude oil and had better performance than EVAL-GO at the same addition level. The best effect was achieved at the dosing concentration of 400 ppm, which reduced the pour point by 13 ℃ and the low-temperature viscosity by 85.4%. The nanocomposites dispersed in the oil phase influenced the precipitation and crystallization of wax molecules through heterogeneous crystallization templates, which led to the increase of wax crystal size and compact structure and changed the wax crystal morphology, which had a better effect on the rheological properties of waxy oil.

Abnormal driving behavior identification based on direction and position offsets

Abnormal driving behavior identification( ADBI) has become a research hotspot because of its significance in driver assistance systems. However,current methods still have some limitations in terms of accuracy and reliability under severe traffic scenes. This paper proposes a new ADBI method based on direction and position offsets,where a two-factor identification strategy is proposed to improve the accuracy and reliability of ADBI. Self-adaptive edge detection based on Sobel operator is used to extract edge information of lanes. In order to enhance the efficiency and reliability of lane detection,an improved lane detection algorithm is proposed,where a Hough transform based on local search scope is employed to quickly detect the lane,and a validation scheme based on priori information is proposed to further verify the detected lane. Experimental results under various complex road conditions demonstrate the validity of the proposed ADBI.

“赶工游戏”对外卖骑手不安全驾驶的影响:基于压力认知评价的视角

为有效防范外卖骑手不安全驾驶行为,减少由外卖骑手引发的交通安全事故,基于外卖平台“赶工游戏”的工作机制,结合压力认知评价理论,从安全态度和示范性规范角度,构建时间压力和竞争氛围感知对外卖骑手不安全驾驶行为影响的理论模型;向全国各地的外卖骑手发放问卷并收集有效样本360份,通过SPSS 27.0和AMOS 24.0数据分析软件分析数据的可靠性,并利用Process 4.0进行层次回归分析验证理论模型。结果表明:时间压力和竞争氛围感知可以显著正向影响不安全驾驶行为;安全态度可以显著负向影响外卖骑手不安全驾驶行为;安全态度可以介导时间压力与不安全驾驶行为的关系,也能介导竞争氛围感知与不安全驾驶行为的关系;示范性规范可以正向调节安全态度与不安全驾驶行为的关系。

Effect of Stimulation of Shenshu Point on the Aging Process of Genital System in Aged Female Rats and the Role of Monoamine Neurotransmitters

In this experiment, among some aged female rats aged over 18 months, and young female rats aged 3 months whose central noradrenergic nerve endings were injured by ventricular injection of 6-hydroxy-dopamine (6-OHDA), it was observed that catgut embedding at bilateral Shenshu (UB 23) points could obviously shorten sexual cycles, increase the frequency of sexual cycle, and slow down the aging process of the genital system in both the aged rats and in the rats with injured noradrenergic endings. After electroacupuncture (EA) at Shenshu (UB 23) points in the aged rats, the frequency of neuronal discharges in locus coeruleus (LC) was elevated and the activating rate of LC to neurons in the medial preoptic area (MPOA) of the hypothalamus was increased, while obvious effect on nucleus raphes magnus (NRM) and the effect of NRM on MPOA were not marked. It is suggested that stimulation of Shenshu (UB 23) point can strengthen the excitability of noradrenergic neurons, activate the ascending pathway of the brain stem - hypothalamus, raise the catecholamine (CA)/5-hydroxytryptamine (5-HT) ratio in the hypothalamus of the aged rats, so as to delay the aging process of the genital system.

Suburban Sightseeing Farm Design from the Perspective of Behaviordriven Design

Suburban sightseeing farm has always been restrained by such problems as focusing on form and visual effect, low design level, poor depth, similarity with others, poor sustainability and so on. This paper proposed major characteristics of sightseeing farm design based on core connotations of behavior-driven design from the perspective of cognitive psychology. Cases were taken to analyze the design techniques of sightseeing farm, and it was concluded that sightseeing farm design based on behavior-driven perspective should orient to performancebased, refi ned, individualized and participatory from the four perspectives of highlighting functions, deepening the details, stressing originality, and optimizing experience, in order to provide new thoughts for solving existing problems of current sightseeing farm design.

基于计算机视觉的工业人员行为分析实验平台

该文面向本科生与研究生实践教学,利用计算机视觉技术开发了工业人员行为分析实验平台。依托工程实训中心,通过多通道数据采集装置收集人员工作环境、作业行为以及劳保用品等数据。基于PyQt5构建工业人员行为分析实验平台,该平台将计算机视觉技术与工业安全管控标准深度融合,以实现工业人员流程类与非流程类作业的行为分析。为验证实验平台的有效性,使用工业人员行为测试数据对所研发的实验平台进行了实验验证。实验结果表明,该实验平台能对工人多种作业进行有效评判。该实验平台有助于提升本科生和研究生在智能图像处理领域的实践能力。

知信行护理模式对老年糖尿病合并高血压患者负面情绪及自我管理行为的长期影响

目的探讨知信行(Krone Access Point,KAP)护理模式对老年糖尿病合并高血压患者负面情绪及自我管理行为的长期影响。方法选取深圳市中医院于2022年3月—2023年3月收治的110例老年糖尿病合并高血压患者为研究对象,按照分层随机法分为常规组(行常规护理)与KAP组(行KAP护理),各55例。比较两组负面情绪与自我管理行为评分。结果干预前,两组焦虑、抑郁评分比较,差异无统计学意义(P均>0.05);干预3、6个月后,KAP组焦虑、抑郁评分均低于常规组,差异有统计学意义(P均<0.05)。干预前,两组在病情监测、饮食、情绪、运动、用药等方面的管理行为评分比较,差异无统计学意义(P均>0.05);干预6个月后,KAP组各方面的管理行为评分均高于常规组,差异有统计学意义(P均<0.05)。结论将KAP护理模式应用于老年糖尿病合并高血压患者,有助于缓解其负面情绪,规范其自我管理行为。

城市连续隧道交织区主线交织车辆换道点选择行为研究

基于城市连续隧道交织区分析主线交织车辆换道点选择行为,以实地采集的车行轨迹数据为基础,利用随机森林模型分析主线车辆换道点选择行为特征及影响行为决策的影响因素,而后分别采用支持向量机模型与随机森林模型进行换道点选择行为决策建模和对比分析。研究结果表明:影响主线交织车辆换道点选择的主要因素为目标车辆状态以及本车道的后车状态,且经特征筛选之后建立换道决策模型的精度更高,其中支持向量机模型可以较好的刻画换道行为,模型的预测精度不低于85%。研究成果有助于在仿真模型中更准确描述换道点选择行为,同时为城市连续隧道交织区的优化和辅助驾驶策略制定提供支撑。

薄壁型钢UHPC组合箱梁受弯性能试验研究

提出一种新型薄壁型钢UHPC组合箱梁,开展了6根薄壁型钢UHPC组合箱梁与1根薄壁型钢箱梁对比梁的四点弯曲静载试验,利用三维数字图像相关测量技术对箱梁的应力-应变与变形及裂缝性能进行测试分析。研究结果表明:外包UHPC能使薄壁型钢箱梁的破坏形态由局部压屈破坏转变为底部薄壁型钢下翼缘及纵筋先后达到屈服后顶部UHPC压碎的正截面受弯破坏;外包50 mm厚UHPC的未配纵筋与箍筋的组合箱梁试件XL2的正截面受弯承载力比薄壁型钢箱梁试件XL1的对应值提升77.5%;薄壁型钢表面焊接了纵筋与箍筋的组合箱梁试件XL3~XL7的整体协同工作性能得到了大幅度提升,其中,XL4试件的正截面受弯承载力比未配纵筋与箍筋的XL2试件的对应值提升了178.8%;增大薄壁型钢壁厚与外包UHPC层厚度也能在一定程度上提高薄壁型钢UHPC组合箱梁的正截面受弯承载力与抗裂能力。

社会信用治理模型选择:由风险预测制迈向行为积分制

模型是对实践的抽象化表达,内含实践的认知理念和价值判断。不同信用模型内含不同的信用治理理念并会产生不同的社会效果。风险预测制模型用于风险预测和秩序控制,在实际社会信用治理中产生过度收集数据、模型黑箱化、难以有效预测等问题。究其原因,在于技术设计过程未能有效反映治理需求,反而消解了人的主体性地位。社会信用治理需要从行为改变出发,迈向行为导向,转换治理范式。行为积分制模型以行为理论为支撑,通过将社区治理过程中的日常事项转化为积分激励事项,推动社区居民积极参与到社区经济、政治、社会、文化、生态等建设中,以共建推动共同治理,将共治行为转化为积分,进而实现治理成果的共享,提供了民主治理的新范式。在推动信用体系建设过程中,应更多考虑行为积分制模型的应用和推广。

住院患者护理行为轨迹闭环管理平台的构建与应用

护士操作行为的规范性直接关系到患者治疗效果和医疗安全。聚焦住院患者护理行为的关键节点,系统化串联护理、医疗、管理等信息系统,构建包含给药、检验和护理巡视行为轨迹追踪、外出检查行为轨迹追踪及手术转运交接行为轨迹追踪三大功能模块的住院患者护理行为轨迹闭环管理平台。应用后,提升了给药准时性,优化了夜间护理巡视方式,缩短了手术患者转运交接耗时,从而保障了患者安全。

体外预应力节段式UHPC无腹筋梁抗剪性能试验研究

体外预应力节段式超高性能混凝土(UHPC)无腹筋桥梁由于其施工工业化水平高且构造简单,得到广泛地关注,但其抗剪性能研究尚不成熟,相关规范也相对滞后。为了研究体外预应力节段式UHPC无腹筋梁的抗剪性能,开展了静力破坏试验,共制作了5根体外预应力节段式UHPC无腹筋梁、2根体外预应力节段式UHPC有腹筋梁和1根体外预应力整体式UHPC无腹筋梁,选取了剪跨比、钢纤维掺量、箍筋间距为研究参数进行试验。结果表明:接缝张开后梁刚度明显下降;添加钢纤维的试验梁的裂缝多而密;钢纤维的掺入可以提高梁的开裂强度、极限强度和裂后性能,2%钢纤维掺量的梁开裂强度比1.5%和0%掺量的增大8.20%和1.16倍;配箍筋的梁在钢纤维失效后箍筋开始受力,并且很快达到屈服,箍筋的存在可以提高梁极限承载力,无腹筋梁的极限承载力比箍筋间距为150 mm和75 mm的梁低15.9%和19.6%。采用AASHTO GSCB INTERIM-2003标准中计算干接缝节段式梁的折减系数0.85。在不考虑安全系数的情况下,法国规范NF P 18-710中UHPC梁抗剪承载力计算公式可以准确地预测含钢纤维体外预应力节段式UHPC无腹筋梁的抗剪强度,其试验值和预测值比值的平均值为1.04,标准差为0.28。

揿针疗法配合耳穴压籽对急进高原人群高原反应、胃肠应激反应及血清CRP水平的影响

目的:探究揿针疗法配合耳穴压籽对急进高原人群高原反应、胃肠应激反应及血清CRP水平的影响。方法:选取2023年1月~2023年12月期间急进高原的60例成年健康人作为研究对象,简单随机分为对照组和观察组,每组30例,对照组行常规干预,不采取任何针刺干预,观察组运用揿针疗法联合耳穴压籽。比较两组进入高原第1d、进入高原第3d、进入高原第5d的高原反应症状评分、胃肠应激反应、生理指标(血氧饱和度、心率、收缩压、舒张压、呼吸频率)及血清CRP变化,并对比两组进入高原前1d、进入高原第3d、进入高原第5d的血红蛋白和皮质醇水平。结果:进入高原第1d、第3d及第5d,两组高原反应症状评分逐渐降低,组内不同时间点比较差异显著(P<0.05),且观察组进入高原第5d评分显著低于对照组(P<0.05);进入高原第1d、第3d及第5d,两组胃肠应激症状评分逐渐降低,组内不同时间点比较差异显著(P<0.05),且观察组进入高原第1d、3d及5d的评分均低于对照组(P<0.05);SpO_(2)、HR、收缩压、舒张压、RR组间、时间点及交互比较,差异均有统计学意义(P<0.05),观察组进入高原第3d及5d SpO_(2)均高于对照组(P<0.05),观察组进入高原第3d及5d收缩压、RR均低于对照组(P<0.05),观察组进入高原第5d HR、舒张压均低于对照组(P<0.05);进入高原后1d及第5d,两组CRP水平均高于进入高原前1d,进入高原后第5d,两组CRP水平均低于进入高原后第1d及3d(P<0.05),且观察组进入高原后第5d时CRP水平低于对照组(P<0.05);进入高原后第1d及第5d,两组血红蛋白、血浆皮质醇水平均高于进入高原前1d,进入高原后第5d,两组血红蛋白、血浆皮质醇水平均低于进入高原后第1d(P<0.05),且观察组进入高原后第5d时血浆皮质醇低于对照组(P<0.05)。结论:揿针疗法联合耳穴压籽可改善急进高原人群的急性高原反应症状和胃肠应激状态,改善患者血氧饱和度、血压和呼吸频率,缓解体内应激反应和炎症反应,具有临床应用价值。