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  • 基于地理坐标的微博事件检测与分析

    Subjects: Library Science,Information Science >> Information Science submitted time 2017-10-11 Cooperative journals: 《数据分析与知识发现》

    Abstract: [Objective] This study aims to retrieve the trending events from the micro-blog platform with the help of data mining algorithms. [Methods] First, we collected micro-blog message with geographic coordinates from the most popular platform (the Sina Weibo) using its API service. Then, we used the K-means, KNN and decision trees algorithms to construct the geographical patterns of those collected posts. The number of published posts, re-tweets, and comments, as well as user activity and movement strength were also examined. Third, we compared these geographical patterns with the daily regional micro-blog data to identify breaking news in that area. [Results] We analyzed data collected on April 15 and April 16 of 2015 with the help of the proposed model, and found a trending event of “Beijing Sandstorm”. [Limitations] The sample size was small, which might influence the results. [Conclusions] Geographic coordinates could help us detect trending events on the Sina Weibo, and this new method will also support the government’s crisis management strategy and decision-making process.

  • Characteristics of leaf venation of Mussaenda and its relative genera

    Subjects: Biology >> Botany >> Applied botany submitted time 2024-04-17 Cooperative journals: 《广西植物》

    Abstract: The classification of Mussaenda L. has been controversial due to the complex interspecific variation and hybridization within the genus, by exploring the variation patterns and taxonomical significance of the leaf venation characteristics between Mussaenda L. and its relative genera (Schizomussaenda Li and Psudomussaenda Wernham.), it could be provide data for the identification and utilization when they were regarded as the medical and garden plant resources. The leaf venation characteristics of 22 species of this group were observed by using the cleaning method. The cluster analysis was carried out based on the characteristics of leaf venation, and a classification retrieval table of the species was compiled. The results were as follows: (1) The characteristics of the leaf venation of Mussaenda L. and its relative genera had consistency, which were mainly reflected on that the primary veins were all pinnate, the frequency of intersecondary veins was less than one per areolation, the angle between the major secondary veins and the midvein was acute, the tertiary veins were mostly penetrating, and the arrangement of the areolation were all irregular. (2) The characteristics of the leaf venation with taxonomic value among genera or species within genera included the type of major secondary vein venation, the angle between the major secondary vein and the midvein, the spacing between the major secondary vein and the midvein, the connection between the major secondary vein and the midvein, the existence of inter-secondary veins and intramarginal secondary veins, the penetration of intercostal tertiary veins, the type of quaternary veins, the branching of freely ending veinlets, and the development of areolation. (3) According to the cluster analysis, the 22 species were clustered into 12 branches, and Schizomussaenda and Psudomussaenda were not clustered into one branch respectively, showing a relatively close genetic relationship. In conclusion, the leaf venation characteristics of Mussaenda and its related taxa can provide new information for the classification of the plants.

  • NaCl 与干旱双重胁迫下黑果枸杞幼苗对外源水杨酸的生理响应

    Subjects: Biology >> Botany >> Applied botany submitted time 2021-08-09 Cooperative journals: 《广西植物》

    Abstract: Under drought and NaCl stresses, the plant growth and development are affected significantly. In this study, to reveal the adaptability of Lycium ruthenicum to salt-drought stresses, the paper used pot culture test method to study the effects of salt and simulated drought interaction experiments on seedling growth, and observe the physiological responses by spraying different concentrations of salicylic acid that improve the survival rate of L. ruthenicum seedlings under salt-drought stress. The results showed that were significantly increased from control in the contents of soluble sugar, soluble protein and proline(Pro) of L. ruthenicum treated with exogenous SA under intercross salt-drought stress in the leaves, the malondialdehyede(MDA) content decreased(P<0.05), whereas increased the activities of catalase(CAT), peroxidase(POD), and superoxide(SOD), among all concentrations, 0.5 mmol·L-1 SA treatment had better effect than 0.1 mmol·L-1 SA. To sum up, L. ruthenicum have a certain ability to adapt mild intercross of salt and drought, moderate concentrations of SA could improve the osmotic regulatory substances and antioxidant enzymes activities in the leaves under salt-drought environment. The study results can provide the theoretical bases for deeply understanding the growing of L. ruthenicum under different stresses.

  • 基于多粒度粗糙集的聚类融合方法

    Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-06-19 Cooperative journals: 《计算机应用研究》

    Abstract: Existing clustering ensemble algorithm starts from the perspective of cluster members, if all the cluster members are used, the ensemble result is affected by the inferior members. If the cluster members are selected and then used in ensemble, the selected strategy has subjectivity. To avoid these two limitations to some extent, from the perspective of elements, nature proposes a new clustering fusion method: selecting a part of class-determined elements through multi-granulation rough sets with incongruous decisions, and then using this part of the elements to generate a new clustering. Multi-granulation rough set model with incongruous decisions can describe the phenomenon of inconsistent decisions with consistent attribute set, a model of multi-granulation rough set with incongruous decisions and a clustering ensemble algorithm based on the model were proposed in this paper. First of all, run a K-Means clustering algorithm several times on the data set in the case, multiple granule structures were generated. Next, inclusion degrees among all the granulations were calculated, and then the matrix of inclusion degree was obtained. Used Otsu’s method to generate a threshold, then several group of granulation that met the threshold condition were got. According to the model of multi-granulation rough set with incongruous decision, lower and upper approximations were obtained. Finally, classified the elements of lower approximation and boundary separately, then a clustering that has been fused was obtained. The experiments showed that the algorithm had a high time efficiency and robustness, which improved the result of K-means clustering.

  • 两种豆科植物及各器官对不同形态氮的吸收、分配研究

    Subjects: Biology >> Botany >> Applied botany submitted time 2023-05-21 Cooperative journals: 《广西植物》

    Abstract: Legumes are abundant in the nitrogen deficient desert ecosystems, which is the center of supplying available nitrogen and the important pioneer species in this region. However, the studies on nitrogen uptake and utilization by leguminous in desert ecosystems have rarely been reported so far. In this study Astragalus flexus and Astragalus arpilobus, which are widely distributed in the Gurbantunggut desert, were selected as the research object. Three different nitrogen forms (15N-NH4 +、15N-NO3 -、15N-Glycine) were added to 0 ~ 5 and 5 ~ 15 cm soil layers, respectively, to study the absorption and distribution strategies of different forms of nitrogen in two plants and their organs. The results showed that: (1) In different soil layers, both plants preferred to absorb nitrate nitrogen, and the maximum absorption rates of Astragalus flexus and Astragalus arpilobus were 3.26、2.59 μg · g–1 · h–1, respectively. (2) In different soil layers, there were significant differences in the uptake and allocation of different nitrogen sources among plant organs (P < 0.05). The uptake of 15N in root of Astragalus flexus was higher than that of Astragalus arpilobus, and the three different nitrogen forms were mainly allocated to leaves. (3) In different soil layers, the contribution rates of different nitrogen sources to both plants were was 15N-NO3 - > 15N-Glycine > 15N-NH4 +, and the contribution rates of nitrate nitrogen to nitrogen absorption of Astragalus flexus were ranged from 37% to 41%, while the maximum contribution rate to the nitrogen absorption of Astragalus arpilobus was 45%. (4) There were significant differences in recovery rates of different nitrogen forms between different organs of plants (P < 0.05). In the 0 ~ 5 cm soil layer, the recovery rate of nitrate nitrogen was leaf > stem > root, while in the 5 ~ 15 cm soil layer, the rate was leaf > root > stem. In general, in the Gurbantunggut desert ecosystem, different life forms legumes had both consistency and difference in nitrogen uptake and allocation capacity, and were affected by different soil depths and nitrogen forms. The results provided theoretical basis for nitrogen uptake, utilization and allocation of legumes in arid and semi-arid regions of Xinjiang.

  • 环氧复合材料表面电位衰减与直流电导特性

    Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2019-03-05 Cooperative journals: 《电气工程学报》

    Abstract:气体绝缘输电管道(GIL)绝缘子通常由环氧树脂 /Al2O3 复合材料浇注而成。在直流电压及负载温升作用下,绝缘子表面易积聚电荷造成电场畸变,进而引发沿面闪络。本文为探索非线性 ZnO 填料对环氧树脂 /Al2O3/ZnO 复合材料绝缘性能的影响规律,对直流电压下不同 ZnO 含量的环氧复合材料表面电位衰减进行了测量,分析了不同温度对表面电荷特性的影响,得到了基于电荷消散的非线性电导变化规律。研究结果表明:直流电压下,ZnO 颗粒掺杂可以明显促进环氧复合材料表面电荷消散;随着温度升高,载流子迁移率增大,表面电荷的消散速度加快;当 ZnO 含量超过一定阈值时,电导率在高场下呈现非线性特性,从而抑制环氧树脂复合材料表面电荷积聚。相关结果为非线性电导复合材料在调控直流气体绝缘输电管道绝缘子表面电荷特性方面的应用提供了参考。

  • 以健康管理为导向的基层门诊慢性病按人头付费标准测算研究——以北京市H区和C区为例

    Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2022-07-11 Cooperative journals: 《中国全科医学》

    Abstract:门诊医疗服务是医保支付方式改革的重要组成部分,随着我国住院医疗服务医保支付方式改革的全面推进,门诊以按人头付费、APG点数法等多元支付方式的改革将逐步提上日程。以慢性病为主探索按人头付费,顺应了从以疾病治疗为中心向以健康管理为中心转变的健康观。本研究基于国内外不同国家和地区按人头付费的实践,以北京市C区和H区为例,通过医疗、医保等基本医疗数据和基本公共卫生服务经费的分析,测算基层门诊主要慢性病按人头付费的标准,为推进门诊慢性病按人头付费改革提供参考。

  • 以健康管理为导向的基层门诊慢性病按人头付费标准测算研究

    Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2022-07-09 Cooperative journals: 《中国全科医学》

    Abstract: Outpatient medical service is an important part of the reform of medical insurance payment method. With the comprehensive promotion of the reform of medical insurance payment method of inpatient medical service in China, the reform of multiple payment methods such as capitation payment and APG point method will be gradually put on the agenda. Focusing on chronic diseases and exploring capitation payment conforms to the health concept from disease treatment to health management. Based on the practice of capitation payment in different countries and regions at home and abroad, taking District C and district h of Beijing as examples, through the analysis of basic medical data such as medical treatment and medical insurance and basic public health service funds, this study calculates the standard of capitation payment for major chronic diseases in grass-roots clinics, so as to provide reference for promoting the reform of capitation payment for chronic diseases in outpatients.

  • 基于ISSR 分子标记的叶子花亲缘关系分析和指纹图谱构建

    Subjects: Biology >> Botany >> Applied botany submitted time 2020-03-06 Cooperative journals: 《广西植物》

    Abstract:该研究从DNA 模板浓度、引物浓度、退火温度和循环次数等方面优化了叶子花ISSR-PCR 反应体系和反应程序,利用11 个ISSR 引物对131 个叶子花品种进行PCR 扩增,扩增产物经琼脂糖凝胶电泳检测,分析品种遗传多样性和遗传距离,并构建品种聚类图和指纹图谱。结果表明,优化的ISSR-PCR 反应体系中DNA 模板浓度为0.5 ng·μL-1,引物浓度为0.5 μM·L-1,引物UBC813、UBC814、UBC815、UBC823、UBC824、UBC835、UBC840、UBC841、UBC843、UBC844 和UBC876 的最佳退火温度分别为52.3、55.9、54.3、54.3、53.6、56.2、56.2、51.9、54.4、54、50 ℃,循环次数为32。用11 个ISSR 引物对131 个叶子花品种扩增出161 条带,其中多态性条带156 条,多态性比率为96.89%。单个引物的等位基因数、有效等位基因数、Nei’s 基因多样性指数和Shannon’s信息指数分别为1.86~2.00、1.33~1.68、0.21~0.39 和0.34~0.57,平均值分别为1.969、1.478、0.294 和0.447。引物UBC841 的鉴别率最高(80.92%),可有效鉴别106 个品种,再与引物UBC876 结合可将131 个叶子花品种完全鉴别开,建立了各品种的指纹图谱。叶子花品种的遗传距离范围为0.00~0.60,平均值0.365,遗传多样性较低,在遗传距离0.58 处,131 个品种分为6 大类群,聚类分析表明同一个种的品种大多数聚在一类,但同一个种仍有品种未聚在一类或亚类、也有多个种的品种聚在一类。该研究较为准确的揭示了叶子花种质资源的遗传多样性,建立的指纹图谱为叶子花品种登记、知识产权保护以及品种鉴定提供了可靠技术和有效手段。