排序方式: 共有36条查询结果,搜索用时 31 毫秒
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Near infrared reflectance spectroscopy for the fast identification of PVC-based films 总被引:2,自引:0,他引:2
Laasonen M Rantanen J Harmia-Pulkkinen T Michiels E Hiltunen R Räsänen M Vuorela H 《The Analyst》2001,126(7):1122-1128
Near infrared (NIR) reflectance spectroscopy was used to develop a non-destructive and rapid qualitative method for the analysis of plastic films used by the pharmaceutical industry for blistering. Three types of films were investigated: 250 microm PVC [poly(vinyl chloride)] films, 250 microm PVC films coated with 40 g m(-2) of PVDC [poly(vinylidene dichloride)] and 250 microm PVC films coated with 5 g m(-2) of TE (Thermoelast) and 90 g m(-2) of PVDC. Three analyses were carried out using different pre-treatment options and a PLS (partial least squares) algorithm. Each analysis was aimed at identifying one type of film and rejecting all types of false sample (different thickness, colour or layer). True and false samples from four plastics manufacturers were included in the calibration sets in order to obtain robust methods that were suitable regardless of the supplier. Specificity was demonstrated by testing validation sets against the methods. The tests showed 0% of type I (false negative identification) and 1% of type II errors (false positive identification) for the PVC method, 13 and 3%, respectively, for the PVC-PVDC method and no error for the PVC-TE-PVDC method. Type II errors, mostly due to the slight sensitivity of the methods to film thickness, are easily corrected by simple thickness measurements. This study demonstrates that NIR spectroscopy is an excellent tool for the identification of PVC-based films. The three methods can be used by the pharmaceutical industry or plastics manufacturers for the quality control of films used in blister packaging. 相似文献
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Juuso Sammaljärvi Antero Lindberg Mikko Voutilainen Jussi Ikonen Marja Siitari-Kauppi Petteri Pitkänen Lasse Koskinen 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1557-1575
The purpose of this work was to support the long-term experiments for investigation of rock matrix retention properties at the spent nuclear fuel repository site ONKALO, in Olkiluoto, Western Finland. Towards this end, rock samples were characterised in terms of porosity connected to mineralogy, with emphasis on pore sizes, and fillings. Both filled and unfilled pores were found with unfilled pores being majority in the pegmatitic granite veins of the mostly veined gneiss samples. It was found that the fillings were often connected to local alteration and the alteration caused variation in the range of pore sizes. 相似文献
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A novel approach for the syntheses of carbene adduct 4 is reported. A ring-enlargement strategy was employed for the synthesis of precursors 5 and 6 and established the mechanism of the formation of azulene derivative 6. Synthesis of target precursor 13, a novel precursor for the synthesis of new mesogenic materials, and its various halogenated derivatives (14–16) was carried out. 相似文献
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Nikolaos Pahimanolis Arto Salminen Paavo A. Penttilä Juuso T. Korhonen Leena-Sisko Johansson Janne Ruokolainen Ritva Serimaa Jukka Seppälä 《Cellulose (London, England)》2013,20(3):1459-1468
In this paper, nanofibrillated cellulose/carboxymethyl cellulose (CMC) composite films were prepared using tape casting. The obtained transparent films showed shear induced partial alignment of fibrils along the casting direction, resulting in birefringence in cross polarized light. The carboxyl groups of CMC could be further utilized to create ionic crosslinking by treatment with glycidyl trimethyl ammonium chloride (GTMA). The GTMA treated composite films had improved mechanical properties both in wet and dry state. The chemical composition and morphologies of composites were analyzed with X-ray photoelectron spectroscopy, elemental analysis, scanning electron microscopy and wide-angle X-ray scattering. 相似文献
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A system of determining entrance surface doses (ESDs) from diagnostic X-ray examination is described. It is shown that the radiation yield calibrations of X-ray units (μGym2mAs−1) can be based on very simple measurements with TL dosimeters. Comparisons of determined ESDs with the guidelines of international organizations are carried out with the aim of demonstrating the idea of how these values can be utilized in limiting patient doses. 相似文献
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Ammonia Activation by a Nickel NCN‐Pincer Complex featuring a Non‐Innocent N‐Heterocyclic Carbene: Ammine and Amido Complexes in Equilibrium
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Rudy M. Brown Dr. Javier Borau Garcia Juuso Valjus Christopher J. Roberts Dr. Heikki M. Tuononen Dr. Masood Parvez Prof. Roland Roesler 《Angewandte Chemie (International ed. in English)》2015,54(21):6274-6277
A Ni0‐NCN pincer complex featuring a six‐membered N‐heterocyclic carbene (NHC) central platform and amidine pendant arms was synthesized by deprotonation of its NiII precursor. It retained chloride in the square‐planar coordination sphere of nickel and was expected to be highly susceptible to oxidative addition reactions. The Ni0 complex rapidly activated ammonia at room temperature, in a ligand‐assisted process where the carbene carbon atom played the unprecedented role of proton acceptor. For the first time, the coordinated (ammine) and activated (amido) species were observed together in solution, in a solvent‐dependent equilibrium. A structural analysis of the Ni complexes provided insight into the highly unusual, non‐innocent behavior of the NHC ligand. 相似文献
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Adding a Structural Context to the Deprotometalation and Trans‐Metal Trapping Chemistry of Phenyl‐Substituted Benzotriazole
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Dr. M. Ángeles Fuentes Dr. Alan R. Kennedy Prof. Robert E. Mulvey Dr. John A. Parkinson Dr. Toni Rantanen Dr. Stuart D. Robertson Prof. Victor Snieckus 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(42):14812-14822
Organometallic bases are becoming increasingly complex, because mixing components can lead to bases superior to single‐component bases. To better understand this superiority, it is useful to study metalated intermediate structures prior to quenching. This study is on 1‐phenyl‐1H‐benzotriazole, which was previously deprotonated by an in situ ZnCl2 ? TMEDA/LiTMP (TMEDA=N,N,N′,N′‐tetramethylethylenediamine; TMP=2,2,6,6‐tetramethylpiperidide) mixture and then iodinated. Herein, reaction with LiTMP exposes the deficiency of the single‐component base as the crystalline product obtained was [{4‐R‐1‐(2‐lithiophenyl)‐1H‐benzotriazole ? 3THF}2], [R=2‐C6H4(Ph)NLi], in which ring opening of benzotriazole and N2 extrusion had occurred. Supporting lithiation by adding iBu2Al(TMP) induces trans‐metal trapping, in which C?Li bonds transform into C?Al bonds to stabilise the metalated intermediate. X‐ray diffraction studies revealed homodimeric [(4‐R′‐1‐phenyl‐1H‐benzotriazole)2], [R′=(iBu)2Al(μ‐TMP)Li], and its heterodimeric isomer [(4‐R′‐1‐phenyl‐1H‐benzotriazole){2‐R′‐1‐phenyl‐1H‐benzotriazole}], whose structure and slow conformational dynamics were probed by solution NMR spectroscopy. 相似文献