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1.
本研究以细菌纤维素作为纸质档案的加固剂,制备不同质量分数的细菌纤维素水分散液,均匀喷涂在纸张上,对纸张进行加固处理。采用万能材料试验机、耐折度仪、扫描电镜、柔软度仪、光泽度仪、厚度仪、非接触式分光光度仪、pH计和超景深显微镜等,表征细菌纤维素对纸质档案的加固作用;利用TG/DTG热分析仪和红外光谱仪,表征细菌纤维素对纸质档案微观结构的影响。结果表明,质量分数为0.3%的细菌纤维素加固纸张后,纸质档案的机械强度提高最明显,加固纸张的效果最好;细菌纤维素在加固纸张的同时增加了纸张的稳定性,且没有改变纸张的微观结构。 相似文献
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现代社会中 ,二氧化硫的污染问题日益受到人们的关注。它不但破坏自然环境的生态平衡、危害人类的身体健康 ,还严重影响档案的寿命 ,是档案库房防治的重点对象。过去国内科研人员对二氧化硫对档案纸张的危害主要进行定性分析。我们在大量实验基础上 ,进行定量分析 ,从而为制定我国档案库房空气质量标准打基础。一、实验（一）实验仪器。ＭＴＶ -耐折度测定仪 ;ＹＱ -Ｚ -Ｔ摆锤式纸张拉力试验机 ;ＳＢＤ -１型数字白度仪 ;ＰＨＳ -３Ｃ型数字精密酸度计 ;干湿球温度计 ;ＤＦ２０５电热风干燥箱 ;标准切纸刀 ;真空泵 ;试样处理瓶。（二）实验… 相似文献
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在吉林市档案馆馆藏档案全宗＂吉林理事府＂,有一卷吉林省境内讫今为止最早的汉文纸质文书档案,题名为＂吉林理事府户房为许陈氏呈控卢标欠银不偿案＂（如图）,这卷档案中的卢德容向许清雨借铺货银所立欠据,形成时间为清朝雍正三年（1725年）,档案书写格式为从右向左竖向书写,毛笔行书,档案的制成材质为纸质,纸张形状为长方形。 相似文献
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纸张的酸性物质是影响纸质档案的耐久性、造成其老化加剧的主要因素之一。目前国内外各档案馆、图书馆所保存的纸质档案、图书中,酸性纸张占绝大多数,这些档案、图书面临毁灭的危险。为此,国内外的档案、图书保护工作者研究了不少纸质档案、图书去酸的方法,概括地讲,可分为气相去酸和液相去酸。液相去酸还可分为水溶液法和非水溶液法。在国外大规模去酸比较成功的是韦驮法（非水溶液法）。在国内,去酸研究较国外要滞后,多局限在实验室内,具体应用较少。研究适用于国内情况,能够实际应用、可对纸质档案进行批量处理的去酸系统,具有重要现实意… 相似文献
6.
以羟丙基甲基纤维素（HPMC）为纳米氢氧化钙的稳定剂和纸质档案的加固剂,制备HPMC稳定的纳米Ca(OH)2醇水分散液（H-C分散液）,用于纸张脱酸加固处理。利用X射线衍射仪、激光粒度仪、紫外—可见分光光度计对H-C分散液进行表征,考察HPMC对纳米Ca(OH)2醇水分散液稳定性的影响;采用扫描电镜、pH计、万能材料试验机、耐折度仪等表征H-C分散液对纸张的脱酸加固作用。结果表明,HPMC可长时间稳定纳米Ca(OH)2醇水分散液;对纳米Ca(OH)2具有裹覆作用,提高其在纸张上的均匀分散并减少纳米Ca(OH)2与纸张直接接触,减轻纳米Ca(OH)2对纸张的影响。H-C分散液在提高纸张pH的同时增强纸张的机械性能,并为纸张提供了一定的碱储量。 相似文献
7.
目前,我国的档案绝大多数仍是纸质档案,要使纸质档案有较长的寿命,不但要注意改善档案保护条件,最根本的还是合理选用质量好的纸张。要选购纸张,首先必须熟悉纸张的种类及特点。一、纸张的种类按纸张抄造方式的不同,可分为手工纸和机制纸两大类。（一）我国的手工纸种类繁多,按造纸原料的不同,主要有皮纸的竹纸。皮纸是以韧皮纤维为原料,造纸原料有檀皮、桑皮和猫皮等,这些原料纤维细长,是优良的造纸原料。皮纸的主要品种有：宣纸、罗纹纸、呈文纸、高丽纸和绵纸等。竹纸的主要原料是嫩竹。嫩竹的纤维柔软,合木素少。竹纸的主要… 相似文献
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以草酸/乙醇—氢氧化钡/甲醇保护液、水性氟碳乳液和明胶—甘油溶液三种加固材料为研究对象,采用中性纸、宣纸为载体材料,墨汁、碳素墨水为字迹材料,分别对加固前后纸张的耐折度、色差变化以及字迹材料的耐干热老化、耐紫外老化、耐酸碱和耐氧化等性能进行综合分析比较,进而探讨三种加固材料对纸质档案纸张和字迹材料耐久性的综合影响。实验结果表明:三种加固材料均能提高纸张和字迹材料的耐久性。其中,水性氟碳乳液加固效果最佳,草酸/乙醇—氢氧化钡/甲醇保护液最差。水性氟碳乳液对宣纸和墨汁的加固效果较中性纸和碳素墨水更为理想。 相似文献
10.
电子文件归档及法律证据作用探索 总被引：4，自引：0，他引：4
一现状研究。１ 电子档案相对于传统档案的重大变化。档案的外在形式有３个要素 :（１）内容信息表达方式（如声音、文字、图象等） ;（２）物理载体（如纸张、墨迹、磁带、底片片基、卤化银感光层等） ;（３）把内容信息记录在载体上的方法（如拍照、书写、打字、录音、录像等）。电子档案的内容信息表达方式虽然仍包括文字、图象、声音等 ,但由于把内容信息记录在载体上的方法有了根本性的变化 ,从而导致档案的原始特性发生重大改变。电子档案不再是把文字信息直接记录到纸张上、把图象信息通过镜头影印在底片上、把声音和连续图象信息通… 相似文献
11.
[目的/意义]学术评价对整个学术生态系统的发展具有重要意义。以影响因子和谷歌学术指标为视角,跟踪国内外学术评价指标发展的新动态,思考和探索学术评价指标优化发展的可能方向。[方法/过程]分别选取h5指数排名前50的中英文出版物并查询对应影响因子,分析并检验h5指数与影响因子的关系;对比中英文出版物在学科分布、时间范围、"被引"统计标准等方面的异同和优缺点,总结学术评价指标应考虑的诸多因素。从评价主体、评价对象等维度对网络环境下新的学术评价方式进行探索,对Altmetrics、RCR、PubPeer的创新性学术评价实践进行案例分析。[结果/结论]学术评价体系系统而复杂,与学术出版、交流与传播、保存利用等各环节密切关联,科学合理的评价体系应平衡数量与质量、保持客观中立、兼顾内容与形式,应分层次、多维度、全方位进行学术评价。 相似文献
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Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents. 相似文献
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Thomas L. Bonn 《Publishing Research Quarterly》1994,10(1):55-65
The role of the literary agent and the reception granted agents by publishers have changed markedly over the course of the
twentieth century. Henry Holt’s views of agents, written in the first decade of the century, help define the status and activities
of agents at that time. These are compared with the role of agents today, using archival sources, the book trade literature,
and interviews.
Thomas L. Bonn, review editor of this journal, is a librarian, Library at State University College at Cortland. He is the
author ofUnder Cover: An Illustrated History of American Mass Market Paperbacks andHeavy Traffic and High Culture: The New American Library as Literary Gatekeeper. He is working on a study of American literary agents. 相似文献
14.
Jason J. Jung 《Information Retrieval》2007,10(1):85-109
On the heterogeneous web information spaces, users have been suffering from efficiently searching for relevant information.
This paper proposes a mediator agent system to estimate the semantics of unknown web spaces by learning the fragments gathered
during the users' focused crawling. This process is organized as the following three tasks; (i) gathering semantic information
about web spaces from personal agents while focused crawling in unknown spaces, (ii) reorganizing the information by using
ontology alignment algorithm, and (iii) providing relevant semantic information to personal agents right before focused crawling.
It makes the personal agent possible to recognize the corresponding user's behaviors in semantically heterogeneous spaces
and predict his searching contexts. For the experiments, we implemented comparison-shopping system with heterogeneous web
spaces. As a result, our proposed method efficiently supported the users, and then, network traffic was also reduced.
An erratum to this article can be found at 相似文献
15.
OBJECTIVE: To evaluate the adequacy of the MEDLINE instruction routinely given to all entering medical students at the University of Miami School of Medicine and the ability of students to search effectively for and retrieve evidence-based information for clinical decision making by the end of their third-year. METHODOLOGY: The authors developed and implemented a strategy for evaluating the search strategies and articles selected by third-year students, who participated in the Objective Structured Clinical Examination (OSCE) in June 1996, 1997, and 1998, and reviewed the literature on evidence-based medicine and evaluation of medical student searches. RESULTS: A mean of 5% of the students' search strategies and a mean of 26% of articles selected were ranked "excellent" or "good"; a mean of 26% of search strategies were ranked "fair" and a mean of 69% were ranked "poor"; and a mean of 22% of articles selected were ranked "fair" and a mean of 52% were ranked "poor" based on the strategy developed to evaluate student searches. CONCLUSIONS: Evaluating medical student searches for evidence-based information is an effective way of evaluating students' searching proficiency, and, in turn, the adequacy of the instruction they receive. Based on the results of the OSCE test, the school of medicine expanded the library's educational role and the library implemented major changes in the training program. Information on evidence-based medicine is now incorporated into the MEDLINE instruction. Library faculty evaluate the required searches performed by students for evidence-based information during their first and second years; 30% of students are identified for follow-up, individualized instruction based on the evaluation; and a new case-based curriculum has been proposed with a fourteen-week problem-based learning (PBL) block. These developments are timely in light of the evidence-based competencies recently published by the Association of American Medical Colleges. 相似文献
16.
Borae Jin 《Communication Research Reports》2019,36(2):148-157
The present study explored interaction between humans and artificial agents from a relational perspective. According to theories on interpersonal communication and relationships, criticism by known agents, as compared to unknown agents, could be less negative (the buffering effect of relationship) or more negative (the expectancy violation effect) to human-agent relationships. Using online survey tools, participants who had interacted with an agent were led to one of the same or different agent conditions, in which the same or a new agent gave negative comments (criticism) to participants. Participants evaluated the agent and the interaction with it before and after receiving the criticism. Results showed that a brief acquaintanceship with agents lessened the negative effects of criticism. Participants’ evaluations decreased to a lesser degree when the negative comments were given by the acquaintance agent rather than the stranger agent. Thus, the buffering effect of relationship was supported in human-agent relationships. 相似文献
17.
The original Lotka's Law refers to single scientist distribution, i.e. the frequency of authors Ai with i publications per author is a function of i: Ai = f(i). However, with increasing collaboration in science and in technology the study of the frequency of pairs or triples of co-authors is highly relevant. Starting with pair distribution well-ordered collaboration structures of co-author pairs will be presented, i.e. the frequency of co-author pairs Nij between authors with i publications per author and authors with j publications per author is a function of i and j: Nij = f(i, j) using the normal count procedure for counting i or j. We have assumed that the distribution of co-author pairs’ frequencies can be considered to be reflection of a social Gestalt and therefore can be described by the corresponding mathematical function based on well-known general characteristics of structures in interpersonal relations in social networks. We have shown that this model of social Gestalts can better explain the distribution of co-author pairs than by a simple bivariate function in analogy to Lotka's Law. This model is based on both the Gestalt theory and the old Chinese Yin/Yang theory. 相似文献
18.
Multilingual information retrieval is generally understood to mean the retrieval of relevant information in multiple target
languages in response to a user query in a single source language. In a multilingual federated search environment, different
information sources contain documents in different languages. A general search strategy in multilingual federated search environments
is to translate the user query to each language of the information sources and run a monolingual search in each information
source. It is then necessary to obtain a single ranked document list by merging the individual ranked lists from the information
sources that are in different languages. This is known as the results merging problem for multilingual information retrieval.
Previous research has shown that the simple approach of normalizing source-specific document scores is not effective. On the
other side, a more effective merging method was proposed to download and translate all retrieved documents into the source
language and generate the final ranked list by running a monolingual search in the search client. The latter method is more
effective but is associated with a large amount of online communication and computation costs. This paper proposes an effective
and efficient approach for the results merging task of multilingual ranked lists. Particularly, it downloads only a small
number of documents from the individual ranked lists of each user query to calculate comparable document scores by utilizing
both the query-based translation method and the document-based translation method. Then, query-specific and source-specific
transformation models can be trained for individual ranked lists by using the information of these downloaded documents. These
transformation models are used to estimate comparable document scores for all retrieved documents and thus the documents can
be sorted into a final ranked list. This merging approach is efficient as only a subset of the retrieved documents are downloaded
and translated online. Furthermore, an extensive set of experiments on the Cross-Language Evaluation Forum (CLEF) () data has demonstrated the effectiveness of the query-specific and source-specific results merging algorithm against other
alternatives. The new research in this paper proposes different variants of the query-specific and source-specific results
merging algorithm with different transformation models. This paper also provides thorough experimental results as well as
detailed analysis. All of the work substantially extends the preliminary research in (Si and Callan, in: Peters (ed.) Results
of the cross-language evaluation forum-CLEF 2005, 2005).
相似文献
| Hao YuanEmail: |
19.
[目的/意义] 面对图书馆学情报学学科在信息分化问题研究中对整体性、以人为本和关注效用等理论的诉求,探寻符合上述诉求的逻辑起点。[方法/过程] 基于对信息分化领域所采用相关概念的梳理,采用扎根理论方法对田野调查质性数据进行分析,归纳可行信息能力概念框架,结合效用主义、可行能力、信息素养等相关理论分析,提出可行信息能力是信息主体在信息行为中表现出来的实质自由。[结果/结论] 可行信息能力表现为信息主体在实践中的功能性活动,是结构因素、能动性因素和具体情境因素共同作用的结果。其中,结构因素主要包括经济条件、社会规范、政策法规、基础设施、信息资源等内容,能动性因素主要包括个人意识、技能、知识状态、社会网络等内容,情境因素主要包括时间、空间和场景等内容。通过探讨可行信息能力作为图书馆学情报学学科概念的适用性,发现其对信息贫困、信息行为、信息服务等研究领域具有可能的阐释作用。 相似文献
20.
高校图书馆学习支持服务活动体系及其模型建构 总被引：1，自引：0，他引：1
[目的/意义] 总结高校图书馆学习支持服务活动体系并建构模型,以更好地理解高校图书馆学习支持服务的整体结构和运行机理。[方法/过程] 基于实际调研和主要职能总结出高校图书馆学习支持服务的基本形式和支撑条件。以活动为基本单位,分析学习支持服务活动的运行机理,进而尝试建构高校图书馆学习支持服务活动模型。[结果/结论] 资源服务形式和素质培育形式是高校图书馆学习支持服务的基本形式,空间、技术、人员是学习支持服务的3个支撑条件,应与基本形式相结合。两种基本形式与3个支撑条件的各种组合构成了高校图书馆学习支持服务的活动体系,需要基于活动的设计和组织进行深度融合。建构了一个高校图书馆学习支持服务活动的双螺旋模型,在机理上呈现出主体性的活动推动、非线性的逻辑递进、协同化的支持服务、共生式的融合发展等特征。 相似文献