Subjects: Astronomy submitted time 2023-10-07 Cooperative journals: 《天文学报》
Abstract： Satellite constellations are widely used for communication, navigation and Earth observation purposes. They provide good ground coverages and serve better for these needs. Of all the configurations, the Walker constellation is extensively applied in many navigation satellite systems and some low Earth orbit communication constellations, since it can be easily designed and has good coverage. Despite of these advantages, the satellites in Walker constellation generally have different ground tracks. When multiple Walker constellations are to be coordinated, in terms that the orbital planes precess synchronously with the same satellite mean motion $\Omega_1$, the semi-major axes of these Walker constellations would be significantly different even when the orbital inclinations differ by a small amount. The Space Exploration Corp (SpaceX) claimed a new constellation design in a patent for their multi-shell Starlink satellite constellation. Constellation shells with different inclinations have small altitude differences, which facilitates regulatory approval and deployment. Satellites in the same shell can also be easily designed to share the same ground track. Although they claimed these features in the patent, SpaceX shared little technical details regarding how to design these constellations. Here in this paper, we analyze the features of the Starlink constellation and try to find a practical approach to design a Starlink-like constellation, as well as how to determine the rules for inter-satellite links within the constellation.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] User portrait marks the behavioral characteristics of academic groups, which provides basis for user identification, precise marketing of academic social platform and improvement of user experience during cold boot period.[Method/process] The public users behavior data is obtained and processed by using Python and R language. The model of user portrait is constructed from five dimensions:user basic attribute, positivity, authority, blog post influence and interest preference. The empirical study takes the blog users behavior data of Science Web as an example.[Result/conclusion] This paper proposes specific indicators and calculation methods to characterize the user characteristics of academic blogs, which shows the user portrait model has certain theoretical significance and application value for the management and operation of academic social platforms.
Subjects: Psychology >> Developmental Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Audiovisual temporal integration is the fact that the relative timing of audio-visual stimulation should be bound into a unified percept. The audiovisual temporal integration of autism spectrum disorders (ASD) was confirmed to be impaired mainly in four aspects. First, the temporal binding window is wider and more symmetrical. Second, ASD got weaker ability of rapid audiovisual temporal recalibration. Third, the effect that visual target search can be improved by a synchronous sound decreased has been found to be missing in ASD in some studies. Last, ASD showed impaired audiovisual temporal acuity for speech stimuli. Various methods are used to probe for temporal aspects of audiovisual integration, such as sound-induced flash illusion task and "pip-pop" task. The simultaneity judgment task, temporal order judgment task and preferential-looking task are mainly used to measure intersensory synchrony. Relevant theories from abnormal neural processing, the internal priors and the interaction between multiple sensory modals explain those defects. In future, researchers should improve the ecological validity of study, further integrate different theoretical explanations and accurate quantitative diagnostic indicators, as well as exploit the effective intervention strategies.
Subjects: Psychology >> Social Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Experiential consumption refers to the consumption behavior with the purpose of obtaining an experience, while material consumption refers to the consumption behavior with the purpose of obtaining a kind of material goods. Previous studies found that these two different types of consumption have many different effects across different fields. Our study summarizes major research paradigms, assessment tools and research approaches used in past studies. Besides, differences in psychological and behavioral effects of these two types of consumption across different domains were summarized. Future research may pay more attention to the antecedents and internal dimensions of different consumption types, emphasize model construction, consider using search engine query data, and examine the possible “dark side” of experiential consumption.
Subjects: Psychology >> Social Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Emotion regulation is an essential ability to maintain individual mental health and life happiness. Cognitive reappraisal is one of the most effective emotion regulation strategies. Cognitive reappraisal inventiveness is a central component of the generation process in the context of cognitive reappraisal. It is the ability to create multiple and different reappraisals for negative situations. The total number and diversity of cognitive reappraisal strategies produced by individuals in cognitive reappraisal (i.e., the fluency and flexibility of cognitive reappraisal strategies) are taken as indicators of cognitive reappraisal inventiveness. A high creative cognitive reappraisal is an effective premise for ensuring individual emotional regulation. Here, we review recent studies on cognitive reappraisal inventiveness. A large body of research demonstrates that inventiveness in cognitive reappraisal is positively correlated with divergent thinking and openness, but not with neuroticism and trait anger. Creative cognitive reappraisal strategies, or high-level cognitive reconstruction using metaphor and analogy, are more conducive to the regulation of negative emotions, and the superior regulatory effect of creative cognitive reappraisal can be mediated by amygdala-based salient emotional arousal, hippocampus-based new association formation, and striatum-based mental rewarding to produce to a novel and positive experience that can be kept in long-term memory. These results are consistent with the creative reconstruction theory of cognitive reappraisal. The theory holds that an individual’s response to negative situations comes not from the event itself, but from their view of the event. Emotional situations are viewed as problems that can be solved by a variety of reappraisal styles. To regulate negative emotions, it is necessary to produce a novel and effective psychological representation of the emotional situation or event, modifying the initial maladaptive representation. Creative individuals may be more likely to find effective reappraisals. However, other studies claim that there is no correlation between cognitive reappraisal inventiveness and reappraisal effectiveness. Thus, no consistent conclusion about the relationship between cognitive reappraisal inventiveness and reappraisal effectiveness has yet been reached. By comparing the neural mechanisms of cognitive reappraisal inventiveness (using the Reappraisal Inventiveness Test, RIT) and traditional creativity (using the Alternative Use Test, AUT), it was found that both, the RIT and AUT, exhibited a comparatively strong increase in alpha power at prefrontal sites, indicating that they have similar brain activation patterns; however, the activation degree of cognitive reappraisal inventiveness is higher in the middle region of the prefrontal cortex, whereas the activation degree of traditional creativity is higher in the ventral prefrontal apex region. The regions of brain activation of the two forms of creativity overlap primarily in the right cerebellum, central anterior gyrus, central posterior gyrus, and anterior cingulate cortex, especially in the left prefrontal network. Cognitive reappraisal inventiveness activates the right superior frontal gyrus, middle frontal gyrus, right middle temporal gyrus, and left and right angular gyrus. Traditional creativity tasks primarily activate the left superior frontal gyrus, left inferior temporal gyrus, and left inferior frontal gyrus. This shows that traditional creativity and cognitive reappraisal inventiveness have common cognitive processing needs, including inhibiting strong responses, switching between different perspectives, and controlling memory retrieval; however, the process of cognitive reappraisal inventiveness requires the specific executive function of emotional representation. Future research may expand the group of participants by selecting participants with emotional disorders (e.g., depression and anxiety disorders), improve the measurement methods of cognitive reappraisal inventiveness, explore the situational and internal factors that affect cognitive reappraisal inventiveness (e.g., positive metaphor, trait anxiety, self-efficacy, and humorous personality), and further reveal how the neural mechanisms of the special process, or reaction mechanism of cognitive reappraisal inventiveness, differ from traditional creativity.
Subjects: Psychology >> Cognitive Psychology submitted time 2021-10-18
Abstract： Emotion regulation ability is an essential ability to maintain individual mental health and life happiness. Cognitive reappraisal inventiveness is the ability to generate multiple reappraisals spontaneously when facing negative situations, and is a creative process in emotion regulation. Here, we review recent work on the Cognitive reappraisal inventiveness. A large body of research demonstrates that cognitive reappraisal inventiveness is positively correlated with divergent thinking and openness but not with neuroticism and trait anger. Creative cognitive reappraisal strategies or high-level cognitive reconstruction using metaphor and analogy are more conducive to regulating negative emotions, and the superor regulatory effect of creative cognitive reappraisal can be mediated by amygdala-based salient emotional arousal, hippocampus-based new association formation and striatum-based mental rewarding to lead to a novel and positive experience that could be kept in long-term memory. These results are consistent with the creative reconstruction theory of cognitive reappraisal. The creative process of reappraisal needs top-down cognitive control and a specific executive function of emotional representation. Future research may expand the group of participants, improve the measurement methods of cognitive reappraisal inventiveness, explore the situational and internal factors affecting cognitive reappraisal inventiveness, and further reveal how the neural mechanisms of the special process, or reaction mechanism of cognitive reappraisal inventiveness, differ from traditional creativity. "
Subjects: Biology >> Botany >> Applied botany submitted time 2021-04-02 Cooperative journals: 《广西植物》
Abstract：在进行多肉植物资源调查时，在我国山东发现一仙人掌科仙人掌属新记录种——匍地仙人掌[Opuntia humifusa (Raf.) Raf.]。该种具有独特的匍匐生长习性，叶状茎深绿色，无白霜，无针状刺，花黄色，与国内分布的仙人掌属其他物种区别明显。匍地仙人掌原产于北美洲，是仙人掌科为数不多的耐寒种类之一，现归化于中国山东省日照市五莲县，系目前发现的在我国野外分布最北的仙人掌科植物。该种可能于? 20 世纪? 50 年代在国家推广中药材时期引入种植，人类活动致使其种群逐渐扩散。同时，对匍地仙人掌与江苏报道的二色仙人掌之间的分类学问题进行了论述，并对将来匍地仙人掌在我国暖温带地区合理的开发利用进行了展望。
Subjects: Biology >> Botany >> Applied botany submitted time 2020-09-15 Cooperative journals: 《广西植物》
Abstract：为探究纤枝短月藓LEA2 基因的结构和表达特征，该研究以纤枝短月藓为材料，首次利用PCR 克隆技术得到纤枝短月藓BeLEA2 基因序列，对该基因进行分析。结果表明：该基因序列中含有2 个外显子和1 个内含子，其开放阅读框（ORF）为 456 bp，编码151 个氨基酸,预测其相对分子质量为16 515.96 Da。将纤枝短月藓与其他植物LEA2 基因氨基酸序列进行比对，构建系统进化树，结果显示纤枝短月藓与小立碗藓的亲缘关系最近。利用HiTail PCR 技术克隆获得1 072 bp 的BeLEA2 启动子序列，用PlantCARE 在线工具对该启动子的顺式作用元件进行预测，结果表明该启动子除了含有核心启动子元件TATA-box 和CAAT-box 外，还含有ABRE、MYB、MYC、MYB 结合位点（MBS）等其他顺式元件。实时荧光定量PCR 分析表明，BeLEA2 基因在纤枝短月藓不同发育时期和不同组织中都有表达，且对脱水胁迫有响应。以上结果为进一步探究LEA2 基因在苔藓植物中的功能及作用机制奠定了基础。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2019-08-02 Cooperative journals: 《干旱区地理》
Abstract：通过对比选用14时实测值法利用1981—2016年全省96站14时相对湿度和能见度数据重建全省历史霾数据序列，分析区域内霾天气的特征及相关气象要素的特征，并探讨大范围持续霾天气过程对应的环流形势，研究霾天气过程的成因。结果表明：关中地区是我省霾天气的高发区，其次是陕南的汉中盆地，陕北出现最少。全省霾日数总体呈较明显的上升趋势，2000年后增加显著。从季节变化来看全省及各区域均为冬季霾日数最多，秋季次之，夏季霾日数最少。各区域均在5～8 km能见度、60%～70%相对湿度、静小风时易出现霾天气，西安及关中全年和四季在偏东北风向时霾天气频率较大。冬季地面风速小，相对湿度较大，近地面风场辐合及逆温层的存在，造成关中大气垂直扩散能力较弱，大气污染物发生堆积、累积效应易形成关中地区持续霾天气及严重大气污染。
Subjects: Geosciences >> Atmospheric Sciences submitted time 2018-10-23 Cooperative journals: 《干旱区地理》
Abstract： 以陕西省大气环境中SO2和PM10作为评估对象进行大气环境承载力研究，采用烟云足迹分析法计算了陕西省2010—2013年环境容量系数A值和SO2、PM10环境承载力的时空分布状况。结果表明，陕西省环境容量系数A值变化范围较大，2010—2013年全省年平均A值变化范围为1~5，陕北地区环境容量系数A值最大，其次为关中，陕南最小，2010—2013年关中地区西安、宝鸡和渭南呈现出逐年下降的趋势。SO2环境承载力全省整体上2010—2013年变化范围为-148 578.04 km2~-189 149.59 km2，4年SO2承载力均无余额，其中渭南和西安SO2承载力严重不足且呈下降趋势； PM10环境承载力全省整体上2010—2013年变化范围为12 701.47 km2~44 511.02 km2，4 a PM10承载力均有余额，全省各市除渭南和铜川外4 a均有余额，但总体呈下降趋势。
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