Search results for "Database"

Additional file 3: of Living alone and positive mental health: a systematic review

2019

Search strategies by database. This file presents the search strategies by each database employed in the study. (DOCX 35 kb)

GIAO/DFT 13C NMR Chemical Shifts of 1,3,4-Thiadiazoles

2007

1 H, 13 C and 15 N NMR spectra of 2-acetylamino-1,3,4-thiadiazole and its 5-substituted derivatives have been measured and assigned based on reference data, as well as homo- and heteronuclear 2 D NMR experiments. In addition, the GIAO/DFT approach at the B3LYP level of theory using the 6-311G basis set was used to calculate the 13 C NMR chemical shifts. Although this method gives reliable results for 2-arylhydrazones of 1,3-diphenylpropanetrione, 2-phenacylpyridines, (Z)-2-(2-hydroxy-2-phenylvinyl)pyridines, 4-fluoroanilines, (1Z,3Z)-1,4-di(pyridin-2-yl)buta-1,3-dienediols and their tautomeric forms, the calculated chemical shifts for the 1,3,4-thiadiazoles studied are less satisfactory. Pr…

Thiophen—Mangantricarbonyl-Komplexe

1967

Abstract Cationic thiophenemanganese tricabonyl complexes of the formula [C 4 (CH 3 ) x H 4- x S Mn(CO) 3 ] + have been prepared with 2-methyl-, 3-methyl-, 2,5-dimethyl-, 2,3,5-trimethyl-, tetramethylthiophene, and with thiophene by the reaction of Mn(CO) 5 Cl+AlCl 3 or AlBr 3 with the thiophenes in petrol ether, at 100–110°. The complexions give yellow solutions which are fairly stable. Their IR and some NMR spectra are given and discussed.

4-Fluoroanilines: synthesis and decomposition

2001

Abstract Fourteen N- and/or 2-substituted 4-fluoroanilines were prepared (the series includes N–C2-bridged compounds). Some of them were found to be thermally unstable when dissolved in chloroform. Both 19 F NMR spectra and comparison of GIAO-DFT calculated and experimental 13 C chemical shifts were used to suggest decomposition products of 4-fluoroanilines.

Preparation and structural characterization of (Me(3)SiNSN)(2)Se, a new synthon for sulfur-selenium nitrides.

2002

The reaction of (Me(3)SiN)(2)S with SeCl(2) (2:1 ratio) in CH(2)Cl(2) at -70 degrees C provides a route to the novel mixed selenium-sulfur-nitrogen compound (Me(3)SiNSN)(2)Se (1). Crystals of 1 are monoclinic and belong the space group P2(1)/c, with a = 7.236(1) A, b = 19.260(4) A, c = 11.436(2) A, beta = 92.05(3) degrees, V = 1592.7(5) A(3), Z = 4, and T = -155(2) degrees C. The NSNSeNSN chain in 1 consists of Se-N single bonds (1.844(3) A) and S=N double bonds (1.521(3)-1.548(3) A) with syn and anti geometry at the N=S=N units. The N-Se-N bond angle is 91.8(1) degrees. The EI mass spectrum shows a molecular ion with good agreement between the observed and calculated isotopic distributions…

Synthesis and Structure of Trimethylplatinum(IV) Iodide Complex of 4'-(4-Methoxyphenyl)-2,2':6',2''-terpyridine Ligand and its Halogen Bonding Proper…

2020

Aggregation in Input–Output Tables: How to Select the Best Cluster Linkage

1991

In this paper we try to give a solution to the aggregation problem on working with Input–Output tables. First of all we verify the degree of similarity among the production functions of the industries which aggregate in each sector. Secondly, once we have established the aggregation by using different cluster analysis, we set a number of conditions required to choose the proper linkage method that allows us to characterize the process of aggregation (weighted or unweighted) of the input–output table.

POSTER: Optimizing scientific file I/O patterns using advice based knowledge

2014

Before us, other works have used data prefetching to boost applications performance [1]–[8]. Our approach differs from these works since we do not rely on precise I/O pattern information to predict and prefetch every chunck of data in advance. Instead we use data prefetching to group many small requests in a few big ones, improving applications performance and utilization of the whole storage system. Moreover, we provide the infrastructure that enables users to access file system specific interfaces for guided I/O without modifying applications and hiding the intrinsic complexity that such interfaces introduce.

"A Comment on Tobias Kronenberg's "Construction of Regional Input-Output Tables Using Nonsurvey Methods: The Role of Cross-Hauling"

2012

This article examines the effectiveness of a new non-survey regionalization method: Kronenberg’s Cross-Hauling Adjusted Regionalization Method (CHARM). This aims to take into account the fact that regions typically both import and export most commodities. Data for Uusimaa, Finland’s largest region, are employed to carry out a detailed empirical test of CHARM. This test gives very encouraging results. CHARM is suitable for studying environmental questions, but it can only be applied in situations where foreign imports have been included in the national input–output table. Where the focus is on regional output and employment, location quotients (LQs) can be used for purposes of regionalizati…

Improving Web Prefetching by Making Predictions at Prefetch

2007

Most of the research attempts to improve Web prefetching techniques have focused on the prediction algorithm with the objective of increasing its precision or, in the best case, to reduce the user's perceived latency. In contrast, to improve prefetching performance, this work concentrates in the prefetching engine and proposes the Prediction at Prefetch (P@P) technique. This paper explains how a prefetching technique can be extended to include our P@P proposal on real world conditions without changes in the web architecture or HTTP protocol. To show how this proposal can improve prefetching performance an extensive performance evaluation study has been done and the results show that P@P can…