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排序方式: 共有68条查询结果,搜索用时 15 毫秒
1.
采用空气等离子体对聚丙烯微孔膜进行表面改性,用X射线光电子能谱,扫描电镜表征膜表面形态和微观结构的变化。考察了改性膜的水接触角、水通量以及在浸没式膜-生物反应器中的动态抗污染性能力。结果表明,改性后聚丙烯微孔膜的水接触角从100°减小到40°,膜的水通量提高,污染率下降。改性后聚丙烯微孔膜的亲水性和抗污染能力得到较大提高。  相似文献   
2.
胃肠激素是一类由消化道内分泌细胞分泌的具有调节消化道生理活动和促激素释放等作用的激素。分析了运动与胃肠激素的关系。运动可使大多数胃肠激素的血浆浓度发生改变,而胃肠激素的浓度的改变可能影响机体在运动时消化道的生理活动和能量代谢等。  相似文献   
3.
谷氨酰胺在运动免疫中的作用   总被引:1,自引:1,他引:0  
谷氨酰胺免疫系统一些细胞以较高速率利用,对于这些细胞的生存及正常功能的发挥十分必要。在长时间运动后及过度训练时,血浆中谷氨酰胺浓度减少,提示持续的身体练习能影响肌肉组织对谷氨酰胺的释放,以致不能满足免疫系统对谷氨酰胺的需要,因此,血浆谷氨酰胺水平的下降造成免疫功能受损  相似文献   
4.
Pseudo-relevance feedback (PRF) is a classical technique to improve search engine retrieval effectiveness, by closing the vocabulary gap between users’ query formulations and the relevant documents. While PRF is typically applied on the same target corpus as the final retrieval, in the past, external expansion techniques have sometimes been applied to obtain a high-quality pseudo-relevant feedback set using the external corpus. However, such external expansion approaches have only been studied for sparse (BoW) retrieval methods, and its effectiveness for recent dense retrieval methods remains under-investigated. Indeed, dense retrieval approaches such as ANCE and ColBERT, which conduct similarity search based on encoded contextualised query and document embeddings, are of increasing importance. Moreover, pseudo-relevance feedback mechanisms have been proposed to further enhance dense retrieval effectiveness. In particular, in this work, we examine the application of dense external expansion to improve zero-shot retrieval effectiveness, i.e. evaluation on corpora without further training. Zero-shot retrieval experiments with six datasets, including two TREC datasets and four BEIR datasets, when applying the MSMARCO passage collection as external corpus, indicate that obtaining external feedback documents using ColBERT can significantly improve NDCG@10 for the sparse retrieval (by upto 28%) and the dense retrieval (by upto 12%). In addition, using ANCE on the external corpus brings upto 30% NDCG@10 improvements for the sparse retrieval and upto 29% for the dense retrieval.  相似文献   
5.
With the acidification of paper and paper-containing relics becoming increasingly serious, a convenient, effective and harmless method for deacidification has become an urgent necessity in the protection of paper relics. In this research, a novel method for reducing the acidity of paper by plasma technology is presented, which can be used simply at room temperature and atmospheric pressure. The pH of the paper rises to alkalescence rapidly after treatment and remains stable with no color change, with a slight accompanying increase in the mechanical properties of the paper.  相似文献   
6.
采用空气等离子体对聚丙烯微孔膜进行表面改性,用X射线光电子能谱,扫描电镜表征膜表面形态和微观结构的变化。考察了改性膜的水接触角、水通量以及在浸没式膜-生物反应器中的动态抗污染性能力。结果表明,改性后聚丙烯微孔膜的水接触角从100°减小到40°,膜的水通量提高,污染率下降。改性后聚丙烯微孔膜的亲水性和抗污染能力得到较大提高。  相似文献   
7.
非热等离子体净化挥发性有机废气研究进展   总被引:1,自引:0,他引:1  
文章就非热等离子技术在治理挥发性有机废气时的能量效率及副产物生成问题展开评述。  相似文献   
8.
海底观测网的研究进展与发展趋势   总被引:1,自引:0,他引:1       下载免费PDF全文
海底观测网是人类观测海洋的新型平台,可实现海洋由海底到海面的全天候、原位、长期、连续、实时、高分辨率和高精度观测,对海洋科学发展起到重要的支撑作用。美国、加拿大、日本以及欧洲各国凭借在海洋领域的先发优势,纷纷投入巨资构建海底观测网并成功运行。在现代传感器、水下机器人、海底光纤电缆、物联网、大数据等新型技术的推动下,海底观测网呈现综合性立体观测、数据深度发掘、多种观测计划综合交叉融合的发展趋势。  相似文献   
9.
Although the biochemical dissection of parasitoid-host interactions is becoming well characterized, the molecular knowledge concerning them is minimal. In order to understand the molecular bases of the host immune response to parasitoid attack, we explored the response of Papilio xuthus parasitized by the endoparasitic wasp Pteromalus puparum using proteomic approach. By examining the differential expression of plasma proteins in the parasitized and unparasitized host pupae by two-dimensional (2D) electrophoresis, 16 proteins were found to vary in relation to parasitization compared with unparasitized control samples. All of them were submitted to identification by mass spectrometry coupled with a database search. The modulated proteins were found to fall into the following functional groups: humoral or cellular immunity, detoxification, energy metabolism, and others. This study contributes insights into the molecular mechanism of the relationships between parasitoids and their host insects. Project supported by the National Basic Research Program (973) of China (No. 2006CB102005), the National Natural Science Foundation of China (Nos. 30571251 and 30170626), the Program for New Century Excellent Talents in University of the Ministry of Education of China (No. NCET-05-0513), and the Innovation Research Team Program of the Ministry of Education of China (No. IRT0535)  相似文献   
10.
As the consumption of fructose and saturated fatty acids (FAs) has greatly increased in western diets and is linked with an increased risk of metabolic syndrome, the aim of this study was to investigate the effects of a moderate (10 weeks) and a prolonged (30 weeks) high fructose and saturated fatty acid (HFS) diet on plasma FA composition in rats. The effects of a few weeks of HFS diet had already been described, but in this paper we tried to establish whether these effects persist or if they are modified after 10 or 30 weeks. We hypothesized that the plasma FA profile would be altered between 10 and 30 weeks of the HFS diet. Rats fed with either the HFS or a standard diet were tested after 10 weeks and again after 30 weeks. After 10 weeks of feeding, HFS-fed rats developed the metabolic syndrome, as manifested by an increase in fasting insulinemia, total cholesterol and triglyceride levels, as well as by impaired glucose tolerance. Furthermore, the plasma FA profile of the HFS group showed higher proportions of monounsaturated FAs like palmitoleic acid [16:1(n-7)] and oleic acid [18:1(n-9)], whereas the proportions of some polyunsaturated n-6 FAs, such as linoleic acid [18:2(n-6)] and arachidonic acid [20:4(n-6)], were lower than those in the control group. After 30 weeks of the HFS diet, we observed changes mainly in the levels of 16:1(n-7) (decreased) and 20:4(n-6) (increased). Together, our results suggest that an HFS diet could lead to an adaptive response of the plasma FA profile over time, in association with the development of the metabolic syndrome.  相似文献   
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