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Abstract

This paper offers some insights into scientific collaboration (SC) at the regional level by drawing upon two lines of inquiry. The first involves examining the spatial patterns of university SC across the EU-15 (all countries belonging to the European Union between 1995 and 2004). The second consists of extending the current empirical analysis on regional SC collaboration by including the economic distance between regions in the model along with other variables suggested by the extant literature. The methodology relies on co-publications as a proxy for academic collaboration, and in order to test the relevance of economic distance for the intensity of collaboration between regions, we put forward a gravity equation. The descriptive results show that there are significant differences in the production of academic scientific papers between less-favoured regions and core regions. However, the intensity of collaboration is similar in both types of regions. Our econometric findings suggest that differences in scientific resources (as measured by R&D expenditure) between regions are relevant in explaining academic scientific collaborations, while distance in the level of development (as measured by per capita GDP) does not appear to play any significant role. Nevertheless, other variables in the analysis, including geographical distance, specialization and cultural factors, do yield significant estimated coefficients, and this is consistent with the previous literature on regional SC.

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Abstract

Ti-SBA-15, one of the latest titanium silicalite catalysts, has been prepared according to the literature by the direct hydrothermal synthesis using Pluronic 123 as structure-directing agent. The characterization of the catalyst was performed by means of the following methods: XRD, IR, UV–Vis, X-ray microanalysis and SEM. The catalytic properties of the Ti-SBA-15 catalyst have been tested in the epoxidation of allyl alcohol, methallyl alcohol, crotyl alcohol and 1-butene-3-ol with hydrogen peroxide. The process has been described by the following main functions: the selectivity to epoxide compound in relation to allylic compound consumed and the conversion of allylic compound.

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Abstract

The article highlights the worldwide dissemination of precision agriculture scientific researches published from the period of 1996–2018, data gathered in the Scopus citation database, using the science mapping method. The findings show that there is a constant rise in the number of publications in precision agriculture. The USA is not only leading in the adoption of precision agriculture technologies but also in the publication of papers, accompanied by China placed in second place. The most frequent keywords highlighted the main topics authors concentrated on more, and the national affiliation of most cited papers was the USA. The main prominence and contributions of the results present scientific research trends in precision agriculture in the last two decades, and demonstrate the main countries, authors and organizations who have contributed, and were more productive in this area.

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Abstract

Bibliographic databases are frequently used and analysed for the purpose of assessing the capacity and performance of individual researchers or entire research systems. Many of the advantages and disadvantages are the subject of continued discussion in the relevant literature, although only rarely with respect to the regional dimension of scientific publication activity. The importance of the regional dimension of science is reflected in many theoretical concepts, ranging from innovation system theories to territorial cluster concepts and learning regions. This article makes use of the extensive information found in bibliographic data and assesses the reliability of this information as a proxy indicator for the spatial dimension of scientific collaboration in emerging economies. This is undertaken using the example of the emerging field of biotechnology in China from 2000 onwards. Two data sets have been prepared: (1) the frequently used ISI Web of Knowledge database (SCI-Expanded) and (2) the domestic Chinese Chongqing VIP database. Both data sources were analysed using a variety of bibliometric and network scientific methods. The structural and topological similarity of networks, built from co-authorship data, is apparent between the two databases. At an abstract level, general network forces are present, resulting in similar network sizes, clustering, or assortativity. However, introducing additional complexity through regional subdivision reveals many differences between the two data sources that must be accounted for in the analytic design of future scientometric research in dynamic spaces.

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Abstract  

23-Hydroxybetulinic acid (23-HBA) is the efficient antitumor compound extracted from the roots of a Chinese Medicinal Herb, Pulsatilla chinensis (Bge) Regel. To evaluate the effect of radioiodination on cytotoxicity, 23-HBA was radioiodinated with 125I. 125I-23-HBA could be prepared in high yields and good radiochemical purity and was characterized using reverse phase HPLC. In ICR mice bearing Liver Cancer HepA tumor, 125I-23-HBA showed a tumor uptake of 2.1% ID/g at 2 h p.i. and 0.15% ID/g at 48 h p.i on i.v. injection. When injected intratumorally, greater tumor uptake and retention was observed (20% ID/g at 2 h p.i. and 4.6% ID/g at 48 h p.i. respectively).

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Peszeki Z. — Kovács I.: A mezőgazdasági eszközállomány ökonómiai vizsgálata. MTA-AMB Tanácskozás, Gödöllő, 2001. I. 23–24. Kovács I. A

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Rigvéda, IV, 18, 1–2. Asvaghósa: Buddha élete (Buddhacsarita). I. 23–26. Fordította: Vekerdi József. Terebess Kiadó, Budapest, 1999. Asvaghósa

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восточнославя нских язы-ках: наука (зсЈепиа): 8кша ОпешаКз XXIX/3 (1980) 115-120. Кохман 1992 -5 . Косhтап, №е гашгагопе роктшпу XV го 8 у Ј8 к1еј 1е1тто1о 8 п с1ур1отагус 2 -пеј: 8ргаш, 2 с1ата ОроШе^о ТРМ; л^с1 2 . II, 8 епа В, I

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. , I. 23, 2--3, 127--137. Steiner F 1977: Quantitative interpretation of gravity and magnetic data systems taking into account geological data and relationships (in Hungarian). Nehézipari Müszaki Egyetem Közl. , I., 23, 2

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) Equation Eq. Parameter 1 Parameter 2 t i (23 °C)/year t

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