Semantic Feature Dictionary Construction of Abstract in English Scientific Journals

[目的/意义]论文摘要是信息组织的重要标引对象,将论文摘要按一定结构进行标引有利于科学传播、知识发现和情报分析。如何对现有非结构式摘要进行精准快速的自动标引是亟待解决的现实问题。[方法/过程]假定不同类别的摘要具有内在一致性,即对结构式摘要的研究可为非结构式摘要自动标引提供方法和技术参考。据此,基于美国国家医学图书馆结构要素标签术语集和标签分类映射关系,提出结构要素BOMRC体系和结构式摘要的识别与规范化标引方法。其次选取研究样本并采用文本挖掘方法对样本语料中的单词、动词、三词词块、四词词块等词汇进行词频、TFIDF值等多个指标的定量统计分析,构建能够进行结构要素识别的语义特征词典。最后利用非结构式摘要测试集进行语义特征词典有效性检验。[结果/结论]结果显示,利用语义特征词典方法能够有效识别非结构式摘要的各类要素,并可用于优化以机器学习方法为核心的自动识别模型。&nbsp;</p

Study on the Sustainable Development of the Grassland Production in Loess Plateau──Ⅲ.The Experiment of Builiding Permanent Grassland for herding by reseeding Caragana korshinskii and Lespedeza daharica

黄土丘陵区草地退化严重，通过补播两种豆科植物柠条（Ｃａｒａｇａｎａｋｏｒｓｈｉｎｓｋｉｉ）和兴安胡枝子（Ｌｅｓｐｅｄｅｇａｄａｈｕｒｉｃａ）建立的柠条─长芒草（Ｓｔｉｐａｂｕｎｇｅａｎａ）草地和兴安胡枝子十长芒草地，具有优质、稳产、高产及耐牧、自然更新良好等优点，效果显著．属两种人工建成的由豆科与禾本科牧草组成的永久放牧草地，可以广泛推广

南瓜籽甾醇对大鼠前列腺增生及抗氧化能力的影响Effect of pumpkin seed sterol on benign prostatic hyperplasia and antioxidant capacity of rats

将提取纯化的南瓜籽甾醇作用于丙酸睾酮诱导构建的前列腺增生大鼠模型，研究其对大鼠前列腺增生及抗氧化能力的影响。将50只雄性SD大鼠分为对照组，模型组，南瓜籽甾醇高、中、低剂量组，实验结束后分别测定其前列腺湿重、前列腺指数（PI）、前列腺酸性磷酸酶（PACP）活性及抗氧化指标中的总抗氧化能力（T-AOC）水平、超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量，同时对前列腺组织形态进行切片观察。结果表明：与模型组相比，南瓜籽甾醇高剂量组的前列腺湿重、PI、PACP活性与MDA含量显著降低，并且南瓜籽甾醇中、高剂量组的T-AOC水平、SOD活性显著升高。以上指标的变化均呈现出南瓜籽甾醇高剂量组优于中剂量组的趋势。同时，与模型组相比，南瓜籽甾醇中、高剂量组大鼠前列腺组织细胞受损状况均有所改善，南瓜籽甾醇高剂量组的改善效果更明显。因此，南瓜籽甾醇在一定程度上具有改善大鼠前列腺增生及提高大鼠前列腺组织的抗氧化能力的作用。 The extracted and purified pumpkin seed sterol was used to feed the rats with benign prostate hyperplasia induced by testosterone propionate to study its effect on the benign prostate hyperplasia and antioxidant capacity of rats. 50 Male SD rats were divided into control group, model group, high, medium and low dose groups of pumpkin seed sterol. After the experiment, the prostate wet weight, prostate index (PI), and levels of prostatic acid phosphatase (PACP), total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured, the morphology of prostate tissue was observed simultaneously. The results showed that compared with the model group, the wet weight, PI, PACP activities, and MDA content of the high dose group of pumpkin seed sterol significantly decreased, and the T-AOC level and SOD activity in the midium and high dose groups of pumpkin seed sterol significantly increased. All of the above changes showed a trend of high dose group of pumpkin seed sterol better than medium dose group. At the same time, the prostate tissue cell damages of rats in medium and high dose groups of the pumpkin seed sterol were improved compared with the model group, and high dose group of the pumpkin seed sterol had the most obvious effect. This indicated that pumpkin seed sterol improved the prostate hyperplasia in rats to some extent and improved the antioxidant capacity of rat prostate tissue

宁夏固原云雾山草原自然保护区生态建设的研究

十年来，根据保护区的特点，已摸索出一整套保护区建设的途径与技术；在总体规划经营上，建立了比较严密的保护管理体系,核心区已建成较合理的草原自然生态系统，试验区的植被基本得到恢复；在综考的基础上，科研以旱地建设为目标，摸索出了半干旱黄土丘陵区草场恢复改良的途径与技术,先后引进筛选优良牧草20种,其中沙打旺。红豆草等8种已得到大面积推广种植,并在野生沙打旺特性及引种驯化方面的研究取得了突破性进展