Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Comparative documents are important for judging whether a patent can be granted or invalid. Aiming at the shortcomings of traditional information retrieval methods and rarely using machine learning methods to study the issue of comparative document retrieval, based on the introduction of comparative file information, this paper constructs a patent relevance determination model.[Method/process] Experiments were performed by using the target patents and comparative documents in the patent invalidation judgment as the data set to extract text similarity, co-occurrence vocabulary, and co-word quantity feature information. The GBDT model was used to convert the retrieval of comparative documents into classification issues that determined whether they were relevant.[Result/conclusion] The research results show that the contribution of different field data to the classification effect is different, in which the F1 of the description text reaches 59%, and the classification effect after multi-feature integration is significantly better than the result of single text similarity. Finally, this paper analyzes the experimental misclassifications and points out the next research directions.
Subjects: Geosciences >> Geography submitted time 2020-01-06 Cooperative journals: 《干旱区地理》
Abstract：以塔克拉玛干沙漠腹地的沙粒胶结体（Sand Cemented Bodies,SCB）为研究对象，通过野外自然状态下吹蚀不同沙粒胶结体覆盖度的沙盘，计算沙面风蚀（积）量，并对覆盖度与风蚀率、抗风蚀效率的关系进行分析。结果表明：风蚀量随沙粒胶结体覆盖度的增加而减小，随吹蚀时间的增加而增加；当覆盖度大于30%时，沙面发生风沙堆积，且堆积量随覆盖度和吹蚀时间的增加而增加；沙粒胶结体的抗风蚀效率随覆盖度的增加而线性增大。沙面蚀积转化临界覆盖度为30%左右，且该覆盖度下床面抗风蚀效益最佳。通过对比沙粒胶结体抗风蚀效益的风洞模拟和野外实验，表明风况、风速、沙粒胶结体粒径组合不同可导致沙面蚀积差异和临界覆盖度不同。因此，塔克拉玛干沙漠腹地发育的沙粒胶结体具有很好的风蚀抑制功能，可作为流沙固定新措施继续研究开发。
Subjects: Geosciences >> Geography submitted time 2020-01-06 Cooperative journals: 《干旱区地理》
Abstract：利用塔克拉玛干沙漠22个气象站（周边21个站和沙漠腹地1个塔中站）2005—2007年的逐时风记录数据，首先基于输沙势定义计算了2007年各测站的16个方位的输沙势；其次以内积相似度指数聚类分析为基础，再结合其空间分布特点，把该沙漠的动力输沙环境划分为5种类型：沙漠东部库尔勒型（西西南型）、北部新和型（偏南型）、西部策勒型（偏东型）、南部民丰型（东东北型）和一种特殊类型；其中策勒型输沙势最大、新和型最小；民丰型输沙势方向稳定性最好、库尔勒型最差；此外，输沙势的季节差异上（2007年为例），各测站春夏季（3~8月）的输沙势都很强，占年均输沙势的81.29%~98.79%，尤其是5月份占年输沙势的22.7%~56.8%，冬季（11月~次年2月）几乎无起沙风；沙漠合成输沙势年际变化表现为：输沙势变幅为±33%，输沙方向变幅为±9.6°，其中输沙势值变幅最大是阿拉尔站（±80%），方向变幅最大的是库车站（±24.4°）。
Subjects: Geosciences >> Geography submitted time 2019-01-11 Cooperative journals: 《干旱区地理》
Abstract：新疆荒漠具有分布广泛、成因复杂、类型多样等特点。利用新疆数字地貌图结合Landsat卫星TM数据与GIS制图技术，通过长期野外调查结合有关资料编制荒漠类型图，获得荒漠类型面积数据，据此探讨荒漠分布规律、结构特征、形成演变，并提出利用和保护荒漠的建议。主要结果和结论如下：（1）新疆荒漠具有水平地带性分布与垂直地带性分布的规律及非地带性分布特点，荒漠多分布于干旱程度较高的南疆和东部吐鲁番及哈密地区，东部荒漠占新疆面积的45.86 %，占东部区域面积的91.77 %。（2）荒漠分布广，面积大，总面积达1 31.3 104 km2，占新疆面积的80.55 %。荒漠类型面积最大的是沙漠为42.7104 km2，占荒漠面积32.49 %，泥漠面积仅10 638.5104 km2，占0.81 %。（3）荒漠类型复杂多样，成因各异，有沙漠、砾漠、盐漠等11种类型，分别主要由气候、地貌、地表物质组成、人为作用等因素单独或共同作用所形成。（4）受自然环境变化与人为作用，荒漠类型之间、荒漠类型与其它地物之间可发生演变。（5）各种荒漠类型的要素特征不同，宜合理利用荒漠资源，划分荒漠环境退化敏感区，保护荒漠环境，针对不同荒漠类型采取适应保护措施，以保障区域可持续发展。
Subjects: Biology >> Botany >> Botany research, experiment, plant evolution & development submitted time 2018-06-25 Cooperative journals: 《广西植物》
Abstract： Wumeng Mountain is located in the joint zonation between western semi-humid evergreen broad-leaved forest and eastern humid evergreen broad-leaved forest in China. Formation Castanopsis platyacantha, Schima sinensis is a typical forest in this area with complex and diverse types that are only occurrence of Yunnan. Formation Castanopsis platyacantha, Schima scinensis in Wumeng Mountain was categorized into the Mid-montane wet evergreen broad-leaved forest in Yunnan, but it is more close to the eastern humid evergreen broad-leaved forest. Therefore, Its distribution and community characteristics have certain research significance. In order to more understand the community characteristics of this formation in more detail, and find out its relationship with the eastern moist evergreen broad-leaved forest. In this paper, we made clustering analysis on the basis of canopy and shrub layer species of 26 plots. Then, the dominant species in tree and shrubs layer were analyzed by size class structure, height structure, and importance value.
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