语义分类的学科主题演化分析方法研究——以我国图书情报领域大数据研究为例

[目的/意义] 学科主题演化研究有助于掌握学科发展现状、研究热点、研究前沿和发展趋势等情况,是进行科技创新的基础,是面向科技创新的重要研究方向。[方法/过程] 提出一种语义分类的学科主题演化分析方法：将关键词分为研究问题、研究方法和研究技术3类,构建不同语义分类的共词网络;然后基于Fast Unfolding社区发现算法识别具有语义特征的社区（主题）;利用相似度算法计算相邻子时期主题间的相似度,构建学科主题演化图谱,以分析某学科领域研究问题、研究方法和研究技术的变化,实现深度、细致的学科主题演化分析。[结果/结论] 通过对2012-2015年CNKI数据库收录的我国大数据研究领域相关论文数据的处理分析,证明该方法的准确性和有效性。     

基金视角下的学科知识流动网络构建与分析

[目的/意义] 在学科交叉融合的背景和趋势下,科研人员的跨学科研究行为促进了知识在不同学科之间的共享与流动。以基金领域为视角,研究学科知识流动,以期为基金管理工作提出建议。[方法/过程] 提出基于基金代码共现的学科知识流动强度测量方法,并利用社会网络分析方法,对193517个国家自然科学基金项目数据构建学科知识流动网络,探究网络的演变过程以及不同学科层次内知识流动路径。[结果/结论] 通过以上分析,得到如下结论:学科知识流动网络是无标度网络,随着时间的推移,网络的规模和结构都发生显著的变化,网络中重要节点呈非稳态;不同学部之间,存在若干条较为重要的知识流动路径;在某一个学部内,具有较广影响力的一类学科往往更容易构成知识流动链条。     

输水渠道横断面设计水深测试及计算(综合性)实验

输水渠道横断面设计水深测试及计算实验结合“灌溉排水工程学”及“水力学”等学科的知识,在实验过程中,通过对实验数据的测试、分析及计算和渠道模型实物的观摩,加深了对渠道设计原理的理解,与课堂上的理论教学起到了良好的互动作用。     

Reliability of arterial spin labelling measurements of perfusion within the quadriceps during steady-state exercise

Arterial spin labelling (ASL) provides a potential method to non-invasively determine muscle blood flow and examine the impact of interventions such as supplementation and training. However, it's a method with intrinsically low signal, leading to limitations in accuracy and temporal resolution. To examine these limitations, the current study measured perfusion via ASL on three occasions in the rectus femoris of 10 healthy adults, during light and moderate exercise, over three different exercise durations. For data sampled over 9 min, light intensity exercise gave an average perfusion of 35.0 ± 5.1 ml/min.100g^?1 with a coefficient of variation (COV) of 16% and single intraclass correlation coefficient (ICC) of 0.67. For the moderate bout, perfusion was 51.3 ± 5.6 ml/min.100g^?1 (COV 10%, ICC 0.82). When the same data were analyzed over 5 min 24 s, perfusion was 37.8 ± 11.13 (COV 30%, ICC 0.13) during light and 49.5 ± 8.8 ml/min.100g^?1 (COV 18%, ICC 0.52) during moderate exercise. When sampling was reduced to 1 min 48 s, perfusion was 41.2 ± 13.7 (COV 33%, ICC 0.26) during light and 49.5 ± 13.6 ml/min.100g^?1 (COV 28%, ICC 0.04) during moderate exercise. For 9 min a significant perfusion difference was found between the exercise intensities; however, this was not the case for sampling over 5 min 24 s or 1 min 48 s. Such findings illustrate the potential of ASL to non-invasively monitor muscle perfusion under steady-state conditions, but highlight that extended exercise protocols are necessary in order to generate date of sufficient reliability to be able to discriminate intervention dependent perfusion differences.     

The effect of 14 weeks of vitamin D3 supplementation on antimicrobial peptides and proteins in athletes

Heavy training is associated with increased respiratory infection risk and antimicrobial proteins are important in defence against oral and respiratory tract infections. We examined the effect of 14 weeks of vitamin D₃ supplementation (5000 IU/day) on the resting plasma cathelicidin concentration and the salivary secretion rates of secretory immunoglobulin A (SIgA), cathelicidin, lactoferrin and lysozyme in athletes during a winter training period. Blood and saliva were obtained at the start of the study from 39 healthy men who were randomly allocated to vitamin D₃ supplement or placebo. Blood samples were also collected at the end of the study; saliva samples were collected after 7 and 14 weeks. Plasma total 25(OH)D concentration increased by 130% in the vitamin D₃ group and decreased by 43% in the placebo group (both P = 0.001). The percentage change of plasma cathelicidin concentration in the vitamin D₃ group was higher than in the placebo group (P = 0.025). Only in the vitamin D₃ group, the saliva SIgA and cathelicidin secretion rates increased over time (both P = 0.03). A daily 5000 IU vitamin D₃ supplement has a beneficial effect in up-regulating the expression of SIgA and cathelicidin in athletes during a winter training period, which could improve resistance to respiratory infections.     

Features of the Formation of Multi-view Autostereoscopic Image without Vertical Parallax

1.Introduction The reproduction systems of 3D images without using eyeglasses and other special accessories has always attracted attention and aroused great interest of developers and consumers of such equipment because of totally accurate image and method of its presentation.Such systems can be used and are already partially used in advertising,television,different devices (i.e.smartphones,tablet computers),at the exhibitions,etc.,as well as in various technical applications,training systems,simulators,etc.     

矿井轴流式主要通风机经济运行探讨

轴流式通风机是煤矿常用的一种通风设备，用于矿井通风的轴流式风机，不仅功率大而且长时运转，因此，它是煤矿耗电量较大的机械设备之一。针对轴流式风机能量损失的一些原因作以分析，并提出使之可达到经济运行的若干技术措施。     

高校现金流量表编制的依据与编制方法初探

随着我国高等教育事业的发展,高校财务活动已不再是简单的取得财政、事业收入,拨缴规定款项,和核算相关支出。作为会计主体,高校会计核算的内容正逐步走向多样化、复杂化。鉴于这种情况,应尽快在高校财务报表体系中增加现金流量表,全面反映一个学校一定会计期间现金流入、流出和净增加(减少)情况,以改变现行高校会计信息披露不完整,决策依据不充分的现状。     

中国基础研究类高层次科技人才流动特征分析 ——以环境领域为例

探寻我国基础研究类科技人才,尤其是高层次科技人才的流动特征和规律,对于制定我国基础研究类科技 人才发现、培养和发展的政策具有重要意义。本文以环境领域国家杰出青年科学基金获得者为研究对象,对中国该领 域基础研究类高层次科技人才的机构流动和国别流动特征进行分析。基于马斯洛需求理论,进一步对不同动机产生的 人才流动所对应的年龄分布进行探讨,为我国基础研究类高层次科技人才的政策制定提供参考和借鉴。     

自力式流量控制器在热网中的应用

开滦荆各庄热水采暖系统98年以前采用普通阀门调节流量，定量困难，由于在检修过程中频繁开关，导致调节功能失效，供暖用户冷热不均。自98年后逐步改用了自力式流量控制器进行流量控制，改后，在使用过程中解决了以往存在的各种问题，实现了节能节水的效果。