Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：【目的】为了促使教育出版人更加理性地进入大学数字教材出版赛道。【方法】文章通过教育新基建相关政策文本梳理和疫情期间的高校教师调研，理解当前国内教育新基建的“硬环境”和数字教学法的“软环境”对数字教材发展的推动机制。【结果】发现高教教师教学资源“自供给”中出现的版权隐患。【结论】强调指出国内大学数字教材出版不仅具有大时代背景下的统一发展趋势，也具有基于国情的本土特色。
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] According to the text length,the online experiential product review is divided into long text online review and short text online review. Exploring the temporal and content characteristic of these two types of online review provides intelligence basis to e-commerce platform about consumers' online review behavior and product demand preference.[Method/process] Python crawler language is employed to collect information of online review in movie review website,and then the paper constructs an online comment interval sequence. Human behavioral dynamics theory is used to find out time characteristic law in different types of online review,and on the other hand,text mining method is used to discover content characteristics in different types of online review. The characteristics are compared and analyzed in the paper.[Result/conclusion] Taking the movie review websites' online reviews as the data source, from the time perspective,this paper concludes that time interval sequence obeys to the power-law distribution between different types of online review behavior,and from the text mining perspective,it finds that the content characteristics performance similarities as well as significant differences.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] It is of great significance to analyze and understand users' daily Web behavior patterns, which not only makes progress in the domain of user behavior analyse and information retrieval theoretically, but also has potential social values and practical significance in promoting personalized service and information recommendation for the undergraduate-oriented enterprises.[Method/process] In this paper, a new method for college students' behavior Web pattern recognition based on large-scale log analysis was proposed. It included a semi-supervised learning algorithm "MaxMatching" based on deep learning and text analysis, and a hybrid model combined with two characteristic entropy (Shannon Entropy and Real Entropy).[Result/conclusion] The empirical results showed that this method has the excellent performance in the algorithm and the result interpretation. Also, it can generalize and present all-round Chinese college students' Web behavior pattern in three aspects of network ability, temporality and topicality. The method and conclusion can effectively expand the methods about semantic understanding of queries in information retrieval, and provide some reference and feasible suggestions to undergraduate-oriented enterprises on personalized recommendation service.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The 20th Party Congress made a significant proposal: “advance the Beautiful China Initiative and take a holistic and systematic approach to the conservation and improvement of mountains, waters, forests, farmlands, grasslands, and deserts”. Thees tablishment of a sustainable national economy and ecological civilization is a major priority for the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). The GBA’s current land development and protection situation is briefly summarized in the study, which also analyzes the issues with ecological protection and restoration in terms of whole-factor chain management, cross-regional cooperation, and target patterns. From the viewpoints of the system view, holistic view, synergy view, and the study makes pertinent recommendations. The study’s goal is to promote the modernization of the GBA so that people and nature can live harmoniously.
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2022-12-20 Cooperative journals: 《中国全科医学》
Abstract：
Objective To understand the gender differences in risk factors and clinical characteristics of children with global developmental delay (GDD). Methods The data of risk factors and clinical characteristics of children with GDD who were hospitalized for the first time in our hospital from January 2020 to February 2022 were collected retrospectively, and the children with complete case data were included in the study to analyze the gender differences in risk factors and clinical characteristics of children with GDD. Results A total of 799 children with GDD were included, including 568 males and 231 females, the male-to-female ratio is 2.46. Compared with female children, the first visit age of male children was later than that of female children (P < 0.001). Motor developmental delay (51.1%) was the main cause of female children, and language developmental delay (41.4%) was the main cause of male children (P < 0.001). The proportion of males born in autumn (30.6%) was higher than that of females (22.1%) (P < 0.05). In terms of risk factors and clinical features, the proportions of intrauterine distress, abnormal EEG, microcephaly, overdue delivery, small gestational age infants, ultra-low birth weight infants and severe fine motor retardation in male children were 4.9%, 11.1%, 0.9%, 0.7%, 9.2%, 0.5% and 6.7%. Were lower than women (10.0%, 17.7%, 4.8%, 3.0%, 15.6%, 3.0% and 10.2%, respectively). The proportion of ASD and macrosomia in males was 17.4% and 11.8% respectively, which was higher than that in females (8.2% and 5.2%). Conclusion There are gender differences in some risk factors and clinical characteristics in children with GDD. The proportion of females in children with GDD is low, but the clinical symptoms are relatively severe.
Subjects: Library Science，Information Science >> Library Science submitted time 2022-11-26 Cooperative journals: 《图书情报工作》
Abstract：
Network analysis is an effective analysis method and visualization method, is one of the most widely used directions in the field of digital humanities. A systematic summary and induction of the application of network analysis in the field of digital humanities will help the digital humanities researchers quickly i- dentify the capabilities and limitations of network analysis, and to carry out deeper research practice. In this study, we adopted content analysis to summary the papers published in the most influential journals in the international digital humanities field and International Digital Humanities Conference in the past five years. And from the five perspectives of research question, dataset, network special characteristics and network analysis metrics, the organization system for the application of network analysis methods in the field of digital humanities was finally extracted. The organizational structure includes three kinds of data scale (including single text analysis, parallel text analysis and corpus analysis) , five application scenarios ( containing characters a- nalysis network, people relation network, words semantic network, text relevancy network and culture topic net work ),two scales of indicators (including global indicators and local indicators) , and five types of metrics (like composition, density, centrality, clique and structure ).
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：针对遥感能量平衡方法估算区域蒸散发(ET)存在的空间歧义性问题，本文以METRIC模型为例，基于地表温度(Ts)与叶面积指数(LAI)相关趋势图，按照“Ts频率直方图占比前5%的最高温度区、LAI频率直方图占比后5%的裸土区为‘干点’，Ts频率直方图占比后5%的最低温度区、LAI频率直方图占比前5%的湿地或农田为‘湿点’”的提取方案，综合确定研究区的干湿限，并通过下垫面涡度相关系统实测数据验证了模型估算精度。经检验，校准期和验证期的区域ET估算控制精度平均为15%，与以往研究成果相比，结果相对合理，提取方案在一定程度上可为METRIC模型主观确定干湿限提供帮助。将ET估算结果按土地利用分类提取，研究区不同土地利用类型表现为ET水体>ET林地>ET耕地>ET未开发利用土地>ET城乡工矿居民用地≈ET草地，成果对区域遥感ET精准估算研究具有一定参考意义。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-06-28 Cooperative journals: 《干旱区研究》
Abstract： 采用2003-2015年美国宇航局（NASA）发布的AIRS/Aqua L2 Standard Physical Retrieval (AIRS+AMSU) V006 (AIRX2RET)云数据集，选取新疆地区，特别是其云水量较丰富的3大山区为研究区域，研究其云中液态水的时空分布特征。结果表明：从空间分布看，北疆的云水量高于南疆，山区比沙漠盆地丰富，山区迎风面更为丰富，高达50010-6 kgm-2，呈西多东少的趋势。受大气环流的影响，整个研究区域、天山和阿尔泰山的云水量在春季分布较丰富，均高于35010-6 kgm-2，昆仑山在夏季分布较丰富；整个研究区域秋季的云水量分布均较少，在2010-6 kgm-2以下。近13a研究区域云水量的年均值为42.4710-6 kgm-2-455.3210-6 kgm-2，整个研究区域云水量总体平稳，3大山区则呈下降趋势；在2009-2010年研究区域的云水量总体呈上升趋势，天山变化较明显。3大山区云水量的年变化呈单峰形，阿尔泰山、天山和昆仑山云水量最高时段分别出现在2-4月、3-5月和4-8月，峰值分别为822.3010-6 kgm-2、869.7510-6 kgm-2和742.8210-6 kgm-2。
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-11-07 Cooperative journals: 《工程热物理学报》
Abstract： Vortex shedding at the location of trailing edge of the axial fan is an important factor to generate noise. Aiming at ameliorating the wake flow to decrease noise, a sinusoidal sawtooth structure was added to the trailing edge of the axial fan. The effects of the wake and the aerodynamic performance of the axial fan are studied by means of steady and unsteady numerical simulation combined with the experimental verification. The results indicate that the sinusoidal sawtooth structure weakens the power ability of the trailing edge of the blades, which reduces the total pressure of the fan, but enhances the efficiency of the fan under the small and medium flow rate conditions. Meanwhile, it can weaken the wake strength at the lower part of the blade, and the restraining effect on the wake was gradually weakened from the bottom to the middle of the blade. For the purpose of compensation for power capability losses due to serrated trailing edge, numerical predictions about noise on prototype and modified model which operate under higher rotor speed have been both calculated. It is argued that the sinusoidal serrated trailing edge structure has positive effects on reducing low frequency noise. Thus, it can be inferred that this kind of trailing edge with sinusoidal sawtooth structure is an effective way to restrain the low frequency noise of axial fan to a certain extent.
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 research aims to identify shopping tasks from product search, and then analyze the characteristic of multi-task sessions. [Methods] Using the product classification of Taobao, and a list of manually selected product terms, we identified online shopping tasks based on query terms from 19 704 search sessions by 2 754 users. [Results] First, factors influence the number of queries per shopping task: product characteristics, the amount of available products, and the difficulty in describing product category with query terms. Second, we found that in sessions with a major task, the relationship among the shopping tasks is closer. [Limitations] The task identification method based on query terms cannot completely describe the complex consumer shopping behaviors. [Conclusions] This study provides an exploratory understanding of the relationships among various shopping tasks, and may be used to improve product recommendation algorithm, as well as predict shopping behaviors.
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究母猪妊娠期营养水平对后代仔猪肌肉生长和发育的影响。选取体重和日龄相近的长大（LY）杂交后备母猪33头，按体重[（150±9） kg]和日龄（255±10）随机分到3个组：低营养水平组（LN组）、适宜营养水平组（AN组）和高营养水平组（HN组）。每组11个重复，每个重复1头母猪。妊娠前期（1~30 d）各组营养摄入量分别是0.75、1.0和1.5倍维持需要，妊娠中期（30~90 d）在前期基础上提高20%，妊娠后期（91~112 d）在中期基础上提高25%。结果表明：1）与LN组相比，AN和HN组仔猪出生体重和断奶体重及初生仔猪肌肉重（除比目鱼肌）显著或极显著提高（P<0.05或P<0.01）；AN组仔猪半腱肌和背最长肌相对重极显著高于LN组（P<0.01），AN组新生仔猪肌肉蛋白质浓度显著或极显著高于LN和HN组（P<0.05或P<0.01）。2）AN组新生仔猪背最长肌肌球蛋白重链Ⅱx的mRNA表达量极显著低于LN组（P<0.01）。3）AN组新生仔猪背最长肌生肌调节因子4的mRNA表达量显著高于LN和HN组（P<0.05）。由此可见，母猪妊娠期营养水平能显著影响仔猪出生和断奶体重及肌肉重，但是过高或者过低的营养水平都会降低后代肌肉重和肌肉蛋白质的浓度，这可能与生肌调节因子4基因差异表达有关。
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：天线的指向精度是系统的关键指标，影响任务执行的质量。指向改正和标校是提高精度的基本途径。佳木斯66米深空探测系统现有的指向标校工作需要人为制定计划，手动完成大量宇宙天体目标的跟踪扫描，工作期间要不断重复设置目标、操作天线。设计并完成了一套完整的指向标校自动化软件，能够完成标校计划的自动规划和标校观测计划的自动执行，提高了扫描效率，极大地降低了人工操作和干预程度，解放了人力。该系统使标校目标的观测方位和俯仰更加均匀，使结果用于指向改正模型解算时能更好地提高指向精度。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-15 Cooperative journals: 《金属学报》
Abstract：摘 要 利用SEM、XRD和TEM等分析手段研究了固溶处理对热压烧结CoCrW合金相组成的影响；通过硬度测试、室温拉伸和摩擦磨损实验，研究了固溶处理对热压烧结CoCrW合金力学性能的影响。结果表明：热压态与固溶态CoCrW合金的组成相均为M23C6、M6C、CrCo金属间化合物和γ-Co基体；固溶处理降低了合金中的M23C6含量、原始颗粒边界，同时改善了合金塑性和耐磨性能。合金室温硬度、抗拉强度均随固溶温度升高、固溶时间延长而先增高后降低。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-14 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：以 NaCl+NaHSO3为腐蚀介质，通过浸渍干湿复合循环实验及腐蚀失重分析，并利用SEM，XRD和FTIR技术，研究了Q235 碳钢和P265GH 低合金钢的大气腐蚀行为。结果表明，两种钢的腐蚀遵从相同的动力学规律,腐蚀产物中均存在大量致密的FeOOH 和非晶态FeOOH，锈层具有很好的保护性，使得腐蚀速率降低。实验开始阶段两种钢的腐蚀量基本相同，但随着腐蚀的进行两者差距增大，P265GH 低合金钢比 Q235 碳钢的失重小、锈层致密、耐腐蚀性好。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-11 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：通过循环盐雾腐蚀实验，模拟镀锌钢在酸雨环境中的腐蚀过程。采用腐蚀质量损失测试、扫描电镜(SEM)、X 射线能谱(EDS)和电化学技术分别对腐蚀48h、84h、132h、180h 和228 h的镀锌钢试样进行测试分析，得到腐蚀动力学、腐蚀产物成分、锈层截面形貌以及表面锈层的电化学特性，研究锈层对镀锌钢在酸雨条件下大气腐蚀的影响。动力学分析表明，腐蚀过程中镀锌钢的表面形成了具有较好保护性的锈层；电化学测试结果表明，锈层的保护性呈现随腐蚀时间的延长先增强后减弱的变化过程。
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