首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   69篇
  免费   0篇
化学工业   6篇
机械仪表   7篇
轻工业   1篇
无线电   5篇
一般工业技术   46篇
冶金工业   4篇
  2022年   6篇
  2021年   2篇
  2020年   3篇
  2019年   3篇
  2018年   2篇
  2017年   3篇
  2016年   5篇
  2014年   7篇
  2013年   3篇
  2012年   7篇
  2011年   11篇
  2010年   5篇
  2009年   3篇
  2008年   2篇
  2006年   1篇
  2003年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
排序方式: 共有69条查询结果,搜索用时 31 毫秒
1.
2.
Accurate measurement of institutional research productivity should account for the real contribution of the research staff to the output produced in collaboration with other organizations. In the framework of bibliometric measurement, this implies accounting for both the number of co-authors and each individual’s real contribution to scientific publications. Common practice in the life sciences is to indicate such contribution through the order of author names in the byline. In this work, we measure the distortion introduced to university-level bibliometric productivity rankings when the number of co-authors or their position in the byline is ignored. The field of observation consists of all Italian universities active in the life sciences (Biology and Medicine). The analysis is based on the research output of the university staff over the period 2004–2008. Based on the results, we recommend against the use of bibliometric indicators that ignore co-authorship and real contribution of each author to research outputs.  相似文献   
3.
The literature dedicated to the analysis of the difference in research productivity between the sexes tends to agree in indicating better performance for men. Through bibliometric examination of the entire population of research personnel working in the scientific-technological disciplines of Italian university system, this study confirms the presence of significant differences in productivity between men and women. The differences are, however, smaller than reported in a large part of the literature, confirming an ongoing tendency towards decline, and are also seen as more noticeable for quantitative performance indicators than other indicators. The gap between the sexes shows significant sectorial differences. In spite of the generally better performance of men, there are scientific sectors in which the performance of women does not prove to be inferior.  相似文献   
4.
Policy makers, at various levels of governance, generally encourage the development of research collaboration. However the underlying determinants of collaboration are not completely clear. In particular, the literature lacks studies that, taking the individual researcher as the unit of analysis, attempt to understand if and to what extent the researcher’s scientific performance might impact on his/her degree of collaboration with foreign colleagues. The current work examines the international collaborations of Italian university researchers for the period 2001–2005, and puts them in relation to each individual’s research performance. The results of the investigation, which assumes co-authorship as proxy of research collaboration, show that both research productivity and average quality of output have positive effects on the degree of international collaboration achieved by a scientist.  相似文献   
5.
Lipoprotein(a) [Lp(a)] is a recognized risk factor for atherosclerotic cardiovascular disease. It is made of a lipoprotein particle containing apoB100 linked by a single disulfide bridge to apolipoprotein(a), a glycosylated protein with a variable mass. Some authors suggest that oxidative modification could explain the contribution of Lp(a) in the development of atheromatous lesions in a comparable way to low‐density lipoproteins (LDL). Recently, the use of capillary electrophoresis to measure the variations in the relative electrophoretic mobility (REM) of LDL subjected to copper oxidation has been proposed. The aim of this work is to employ this method also to monitor the copper‐induced oxidative modification of Lp(a). Migration of Lp(a) was monitored by absorption at 200 nm in a 50 mmol/L tricine, 100 mmol/L methylglucamine, pH 9.7 run buffer. Contrary to the conventional slab gel methods, our procedure provides a rapid and reproducible means to measure the electrophoretic mobility of Lp(a) (migration time <10 min with a CV% <0.5).  相似文献   
6.
Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.  相似文献   
7.
The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail. Therefore, this study was undertaken to analyze the structure and ultrastructure, as well as the immunohistochemical profile of the zebrafish pineal gland with particular reference to the pinealocytes. Here, we demonstrated, using RT-PCR, immunohistochemistry and transmission electron microscopy, the expression of the mRNA for rhodopsin in the pineal gland of zebrafish, as well as its cellular localization exclusively in the pinealocytes of adult zebrafish. Moreover, the ultrastructural observations demonstrated that the pinealocytes were constituted by an outer segment with numerous lamellar membranes, an inner segment with many mitochondria, and a basal pole with the synapses. Our results taken together demonstrated a central role of zebrafish pinealocytes in the control of pineal gland functions.  相似文献   
8.
Scientometrics - In this paper we develop a methodology to assess the scientific wealth of territories at field level. Our methodology uses a bibliometric approach based on the observation of...  相似文献   
9.
In national research assessment exercises that take the peer review approach, research organizations are evaluated on the basis of a subset of their scientific production. The dimension of the subset varies from nation to nation but is typically set as a proportional function of the number of researchers employed at each research organization. However, scientific fertility varies from discipline to discipline, meaning that the representativeness of such a subset also varies according to discipline. The rankings resulting from the assessments could be quite sensitive to the size of the share of articles selected for evaluation. The current work examines this issue, developing empirical evidence of variations in ranking due changes in the dimension of the subset of products evaluated. The field of observation is represented by the scientific production from the hard sciences of the entire Italian university system, from 2001 to 2003.  相似文献   
10.
Scientometrics - Blockchain technology has become an ubiquitous phenomenon. While the topic originated in computer science, the business and economics literature was comparatively slow to pick up...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号