Subjects: Astronomy >> Astrophysical processes submitted time 2023-10-13 Cooperative journals: 《天文研究与技术》
Abstract： There are two obvious peaks in the spectral energy distribution (SED) of the blazar, of which the low energy peak is the synchrotron radiation peak. There is an inverse correlation between the peak power of the synchrotron radiation peak of the blazar and the peak frequency, so the spectral index plane constructed by the multi-band composite spectral index related to the SED peak can be used as a classifier for the two subclasses of the blazar (flat-spectrum radio quasar (FSRQ) and BL-Lac object). In this paper, the cross matching of multi-wavelength data for the blazars in the Fermi four Catalogue (4FGL-DR3) is carried out through the database of Strasbourg Observatory, and multi-wavelength data set is obtained. Basing on this data set, we find that the distributions of the 8 broad band spectral indices, (αrw1 、αrw2 、αrw3 、αro 、αrγ 、αw1w2 、αw1w3 ）and αw3x , have obvious bimodal structure, and clearly distinguish the two subclasses of blazed variants (FSRQ and BL Lac). Through the support vector machine model in machine learning technology, we further analyze the classification effect of spectral index plane on subclasses of blazar, and find that most of the accuracy rates are above 80%.
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：电视新闻节目已经成为现代人们获取新闻信息的重要途径,人们可以通过电视新闻节目了解时政热点、军事动态,以及一些关系到国计民生的讯息。为了能够更好地解读新闻信息,传递新闻资讯,电视新闻播音员除了要具备扎实的专业基础外,还要通过不断的借鉴融合一些他人的成功经验,经过发展创新,逐步养成自己的播音技巧,更好地为新闻播报。本文通过对电视新闻播音技巧养成的重要性、电视新闻播音技巧养成的措施两个方面进行了分析,希望对各位的工作能够有所帮助。
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Since the outbreak of Coronavirus Disease 2019 (COVID-19), lots of information and public opinions have been rapidly spread. For the emergency management and scientific decision-making of major public health emergencies, it is of great value to accurately understand the individuals' information acquisition behavior and analyze the factors of fear of missing out (FoMO).[Method/process] Based on the use and satisfaction theory and cognitive psychology, a research model was proposed to examine the relationships among boredom proneness, FoMO, information acquisition behavior, and emotion constructs. Sample data (N=957) was collected through an online survey, then partial least squares method was performed to test the research model, and interview was conducted for discussing the results.[Result/conclusion] During a major public health emergency, mobile new media is the main channel for information acquisition. Receiving message notifications and active searching are the main information acquisition behaviors. Individuals spend more time reading or watching information, with the characteristics of high frequency and short time interval acquisition. The results show that attention on COVID-19 has a positive influence on FoMO and information acquisition behavior, and there is a significant positive relationship between boredom proneness and FoMO. FoMO is the motivational factor of information acquisition, which has significant positive effect; individuals with higher FoMO are more likely to get negative emotions; information acquisition has a significant effect on negative emotions.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-03-28 Cooperative journals: 《干旱区研究》
Abstract： The status of air pollution in China has been recognized as a serious health concern in numerous academic circles. Air quality is an important factor for defining air pollution, and main pollutants used to evaluate its quality, include PM2.5, PM10, SO2, NO2, CO, and O3. Hotan is one of the oasis cities with severe air pollution crisis. The located in the southwest edge of Taklimakan Desert in the southernmost part of the Northwest Xinjiang province in China. The soil structure in this area is loose, dust storms are frequent, and particles carried by dust storms are heavily deposited, which result in an increase in the concentration of pollutants. Therefore, the air Pollution caused by these particles results in severe challenges. Different types of air pollutants have varied hazards to human health, for example, PM2.5 and PM10, which are the main air pollutants in Hotan City, cause serious human respiratory tract infections, and their sources are extensive, hazardious, and difficult to eliminate. The rapid economic development in recent years and the accelerated urbanization have aggravated the deterioration of air quality in Hotan City, posing a great threat to the physical and mental health of local residents. Therefore, understanding the characteristics of air quality and its potential health effects in Hotan City is crucial for controlling urban air pollution and improving local ecological environment. This study used the historical air quality data in Hotan from 2016 to 2021 to analyze the distribution characteristics of pollutants, to determine the relationship between air quality and potential human health effects, and to evaluate the correlation between pollution levels and air pollutants, such as PM2.5, PM10, SO2, NO2, CO, O3-8H, and AQI. The results showed that between 2016 and 2021, the concentration of O3-8H in two air pollution monitoring points in Hotan had an inverted U-shaped trend, while the concentration of other pollutants showed a U-shaped curve distribution. PM2.5 and PM10 were detected as the main pollutants throughout the year, and their concentrations were relatively high in spring. In addition, concentrations of SO2 and NO2 were high in autumn and winter, while those of CO and O3-8H were high in winter and summer, respectively. During the study period, the concentration of PM2.5 and SO2 decreased, while that of PM10 increased, but the overall air quality did not show significant improvement. The AQI value of air quality index in Hotan City was higher than the national second class level, and its value during the“unhealthy”air quality period was much higher than that during the“healthy”air quality, which suggested a high harmful potential to the physical and mental health of residents.
Subjects: Psychology >> Social Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： This research project explores the emotional mechanisms underlying prosocial and antisocial behaviors in public arenas. By synthesizing several influential theories concerning the roles of emotions in decision-making, we developed a hypothesis of anticipatory emotions as an information source for social risks. We define anticipatory emotions as any discrete emotions that are induced from anticipating expected choice outcomes and felt at the time of decision-making, and in turn, regulate the decision behavior. Risky events in social and public contexts are characterized by their destructive, emergent, transient, and unpredictable nature. Thus, the reactions to these risky events need to be quick and unambiguous. However, the probabilities of possible consequences associated with these reactions are usually hard to reckon with. Under such conditions, anticipatory emotions provide a prompt and overall risk assessment as a substitute for expected utility, reflecting both the likelihood and severity of expected choice outcomes. We view anticipatory emotions as mental representations of social risks. We predict that different profiles of anticipatory emotions collectively distinguish different types of social risks. Moreover, the combinations of anticipatory emotions are culturally specific. The more recent categorization of the face, dignity, and honor cultures allows us to make predictions about the emotional characteristics of each culture. Overall, the proposed four studies with multiple experiments will examine how anticipatory emotions influence reactions to public risks. We explore how dispositional, social, and cultural factors regulate prosocial and antisocial behaviors. The results of these studies will benefit the research in risk management, public policymaking, and provide scientific support to public education, counseling, and civil service training.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-18 Cooperative journals: 《材料研究学报》
Abstract： The effect of coupling agent silane Si69 on properties of nanocomposites of nature rubber with different sized nano-silica (15, 30 and 80 nm)was investigated in terms of curing performance, mechanical properties, Mullins effect, Payne-effect, loss factor, the dynamic heat build-up and dynamic mechanical property etc. while taking the same composites without coupling agent as comparison. Results show that with the addition of the coupling agent Si69, the dispersity of nano-silica in the rubber and the binding of nano-silica with the rubber matrix were improved; the mechanical properties of nano-silica/nature rubber composite were effectively enhanced and the positive sulfuration time t90 was shortened. It is noted that the smaller size of the nano-silica is, the better positive effect on the performance and mechanical properties of the composite can be obtained. Due to the addition of the coupling agent Si69, the Payne-effect, loss factor and the dynamic heat build-up can be reduced for the composites with nano-silica of 15 nm and 30 nm, respectively, but is not obvious for the ones with 80 nm silica.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-18 Cooperative journals: 《材料研究学报》
Abstract： The waterborne epoxy coatings with polyaniline/vermiculite (PANI/VMT) as pigment were prepared. For the sake of identifying the functional groups of PANI/VMT, FT-IR measurement was performed. The thermal behavior of the pigments was characterized by thermal gravimetric analysis (TGA). The anticorrosion performance of waterborne epoxy coatings with different mass ratio of PANI/VMT was evaluated by electrochemical impedance spectroscopy (EIS) and salt spray test. The results show that a proper combination of the anodic protection ability of polyaniline and barrier property of vermiculite results in better performance of the PANI/VMT modified waterborne epoxy coating, for example, a coating with addition of 0.5% of PANI/VMT could provide a long- lasting anticorrosion protection for steel substrate.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-05-21 Cooperative journals: 《广西植物》
Abstract： The response of plant growth and reproduction to future climate change has attracted widespread attention. In order to investigate the spatial distribution patterns of clonal growth and sexual reproduction parameters of emergent plants and the pathways of their environmental factors on plant reproduction. Based on the 3D topography of the Yunnan Plateau, we investigated the geographical differences and changes in the clonal growth and sexual reproduction of Schoenoplectus tabernaemontani, and their response to environmental changes was further investigated through the method of space alternative time. The results were as follows: (1) There were significant differences in clonal growth parameters such as density, plant height, and diameter, as well as reproductive parameters such as seed setting ratio, spike biomass, spike investment ratio, seed production, and the number of active seed in different geospatial (P<0.05), but there was no significant difference in above-ground biomass. (2) The density, plant height, seed setting ratio, spike biomass, and spike investment ratio of S. tabernaemontani showed significant zonal distribution patterns of latitude, longitude, and altitude. Among them, The density increased with the increase in latitude and altitude, and it was decreased with the increase of longitude. Meanwhile, the plant height, seed setting ratio, spike biomass, and spike investment ratio decreased with the increase of latitude and altitude, and gradually increased with increasing longitude. (3) Maximum temperature of the warmest month, minimum temperature of the coldest month, soil total nitrogen and soil total phosphorus were the key factors affecting the growth (density and height) of S. tabernaemontani, where the warm month mean temperature was the greatest influence. In addition, mean annual precipitation and soil organic carbon mostly explained the reproductive characteristics of S. tabernaemontani compared with other influencing factors, among which the mean annual precipitation had the greatest effect. The investigation further showed that the climatic factors were the main factors affecting the growth and reproduction of S. tabernaemontani in the lakeside zone of Yunnan Plateau lakes.
Subjects: Astronomy >> Astrophysical processes submitted time 2021-05-27 Cooperative journals: 《天文研究与技术》
Abstract：通过显式有限元法建立轮轨滚动接触模型，用于分析110米口径射电望远镜滚轮经过焊缝时的应力变化。建模时不仅考虑了焊缝处材料差异，同时还考虑轨道焊缝处表面不平度和摩擦系数的影响，分析了滚轮经过轨道焊缝时轮轨间作用力的瞬态响应。采用层级细分技术对轮轨模型进行前处理，经过静力学分析结果表明，模型求解精度较高。将该前处理模型用于瞬态分析发现，焊缝处表面不平度对轮轨间作用力影响较大，使轮轨间Mises应力增加了约20%，可能会对轨道长期可靠服役带来一定的隐患，因此需要定期对轨道的状态进行检测与维护，保障轨道的长期可靠服役特性。
Subjects: Astronomy >> Astrophysical processes submitted time 2021-04-29 Cooperative journals: 《天文研究与技术》
Abstract：磨损和扭转造成天线俯仰轴结构小尺度变形的快速高精度测量，对修正大口径全可动射电望远镜天线指向精度以及俯仰轴主动健康监测有非常重要的价值。本文提出一种基于虚拟相机的俯仰轴形变测量方法，通过构建单相机测量系统进行数据采集，并建立测量系统数学模型，借助虚拟相机将结构变形转换为虚拟相机空间变换。实验结果表明，该方法在平移分量综合精度可达0.2825mm，旋转分量精度最低可达0.2918o，能够实现俯仰轴1mm尺度变形的快速测量。该系统及其方法具有非接触、精度高、快速性等优点，能满足大口径高频段高精度的射电望远镜俯仰轴长期快速测量需求，也适用于其他大结构小变形测量。
Subjects: Astronomy >> Astrophysical processes submitted time 2021-04-29 Cooperative journals: 《天文研究与技术》
Abstract：为了快速获取副反射面随天线俯仰角变化的位置，并通过调整机构对副面位置进行修正来提高天线综合性能，提出一种虚拟双目视觉测量方法，通过高速相机与平面镜组成的虚拟双目视觉系统对天线观测时副面位置进行模拟实验，获取被测物随实验平台空间移动产生的位置变化图像，并对图像进行预处理、去噪、边缘检测、特征点提取等操作，重建了被测物随实验平台移动而在三维方向上的运动情况，重建结果在三个方向上误差均小于1%，表明该方法具有较高的测量精度，能够较好的对副面位置情况进行重构。
Subjects: Astronomy >> Astrophysical processes submitted time 2019-11-13 Cooperative journals: 《天文研究与技术》
Abstract：无线电监测表明，手机与基站通信产生的干扰信号会影响射电天文观测数据，为了抑制射频干扰，天文学家提出屏蔽站内电子设备、设置无线电宁静区等无线电管理办法，其中的手机信号因易移动、基数大而难于监测和管理。然而，开启手机的飞行模式或关机可以降低射频干扰。基于此，本文设计和开发了一款基于Android系统的手机干扰管理APP，采用定位技术来自动判别手机是否处于无线电宁静区，以提醒用户管理手机，并记录用户在宁静区内的操作。测试结果表明，当用户处于无线电宁静区时，APP能主动提醒用户开启飞行模式或关机，有效降低手机信号对天文观测数据的影响。
Subjects: Psychology >> Social Psychology submitted time 2018-09-07 Cooperative journals: 《心理学报》
Abstract： 分别从特质依恋和状态依恋角度考察施助者的依恋安全在求助者面孔可信度与助人行为之间的调节作用。结果发现：(1)求助者面孔可信度影响助人行为, 面孔可信度高的求助者得到的助人行为显著多于面孔可信度低的求助者; (2)施助者的依恋安全调节求助者面孔可信度与助人行为之间的关系, 安全依恋能有效缓冲低面孔可信度带来助人行为下降的趋势。本研究结果表明依恋安全有助于提升社会安全感和促进亲社会行为, 因此应注重依恋安全的培养。
Subjects: Astronomy >> Astrophysical processes submitted time 2017-10-20 Cooperative journals: 《天文研究与技术》
Abstract：针对中性大气的物理属性以及大气折射对射电望远镜指向的影响进行了模型分析和计算，以改进型的“三段式”标准指向改正模型为基拙，着重研究了由大气折射造成高阶指向误差的改正方案，目的是不断提高射电望远镜的指向精度，尤其针对大口径、高分辨率的射电望远镜。在此模型的基拙上，模拟南山观测基地的气候特征，给出合理的计算结果。通过分析和评估这些结果与射电望远镜指向精度的要求，为将来大口径射电望远镜的指向修正提供参考
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：在地面望远镜观测土星主要卫星的精确定位中，目前普遍采用CCD成像技术。为了测量视场中暗卫星的位置，常采用4 }'u主要卫星(土卫三一土卫六)进行定标。鉴于技术的进步，目前CCD视场正在逐步增加，如何精确定标图像值得研究。利用2010年1月20日在云南天文台1 m望远镜上观测的不同取向的105幅CCD图像进行了试验研究。采用了美国喷气推进实验室土星主要卫星历表和美国海军天文台的UCAC4恒星星表进行计算，相对于不同的参考对象进行定标。结果表明，采用4颗主要卫星进行定标并测量离卫星较近的观测对象时具有较好的测量准确度和内部精度。测量离定标星较远的卫星时，这种定标方法具有较大的不确定性。采用6颗主要卫星(土卫三一土卫八)进行定标，所有卫星的测量结果具有更好的外部和内部符合。即便如此，采用四常数模型和六常数模型定标的结果都不是令人满意，这揭示CCD视场存在明显的扭曲效应。如果采用视场中的恒星定标，卫星的外部符合和内部精度明显变差，这说明UCAC4恒星参考星表也不是理想的定标用参考星表。
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：随着射电天文研究的不断深入，科学家对望远镜分辨率和灵敏度的要求也不断提高，同时要求望远镜具有更宽的观测波段。单口径望远镜低频波段用主焦点接收，馈源尺寸可以更紧凑。为了不影响双反射面天线次焦点的馈电功能，主焦点馈源的放置及换馈方案必须高效合理。以建于新疆奇台的110 m口径全可动射电望远镜为研究对象，以意大利SRT 64 m和德国Effelsberg 100 m射电望远镜为参考，对两种方案应用于奇台110 m射电望远镜的可行性进行分析，并提出一种利用线性模组进行主焦馈源快速切换的新型方案。进行了直线模组机构的建模和仿真，并对口径面信号遮档进行了分析，结果表明，此方案能有效满足望远镜的工作需求。
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：木卫六是木星最大的一颗不规则天然卫星，为了获得它的高精度观测位置，天体测量归算过程中各方面都需要考虑，其中特别重要的是参考星表的选择。应用最新公布的星表Gaia Data Release 1( Gaia DR1)，同时采用UCAC4星表进行比较，对2015年云南天文台获得的185个木卫六的观测资料进行处理和归算，结果显示，采用Gaia DR1星表的木卫六的位置测量精度在赤经和赤纬两个方向都约为0. 02"，比采用UCAC4的结果有显著提升。
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：为分析南山站的光学观测环境条件，在南山观测站使用SBIG, SQM-LE等设备分别对大气视宁度、夜天光亮度和气象数据进行长期监测，在筛选和整理大量监测数据的基拙上，进行逐月、逐年的统计和分析。结果显示，使用SBIG视宁度仪监测南山站年平均视宁度为1. 74"，夜天光亮度为21.7 mag arcsec-Z，年平均温度为3. 4 0C，年平均相对湿度为57. 3 % ,风速主要分布区间为2}3 m/s，主要风向为西南风。上述参数表明，南山观测站的光学观测环境良好，可以满足中、小型望远镜的观测环境要求，测量结果可为其他光学台址起参考作用。
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：随着射电天文的发展，大口径天线的角分辨率越来越高，对天线指向精度的要求高达In量级。由于天线伺服驱动力矩的脉动造成低频谐振，传统PI(D)调节器难以满足更高指向跟踪的需求。结合射电望远镜的工况、伺服控制目的及控制器设计原则，采用一种基于线性自抗扰控制算法，并应用于某天线位置环仿真。分析结果表明，该算法不仅有良好的动态性能和控制精度，而且有较强的鲁棒性。
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