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161.
An evaluation of coating performances in feedback controlled surface temperature laser heat treating has been made in terms of a simple energy balance model, by using a 500 W c.w. CO2 laser system able to perform such a kind of heat treating. Three different types of coating (manganese phosphate, titanium dioxide and colloidal graphite) have been investigated. The experimental results show that very different maximum processing speeds are ensured by each coating, in spite of their quite similar percentage of absorbed laser power. This more complete characterisation can be used to improve the performances of the aforesaid technique, avoiding any failure in controlled surface temperature laser heat treating. 相似文献
162.
Pascale Urizzi Jean‐Pierre Souchard Ginette Ratovo Yvon Coulais Franoise Nepveu Etienne Hollande 《应用有机金属化学》2003,17(4):212-217
The present study was designed to evaluate the potential of labeled low‐density lipoprotein with 111In using a lipid chelating agent (bis(stearylamide) of diethylenetriaminepentaacetic acid: L) to detect pancreatic tumors and melanoma in mice by gamma‐scintigraphy. We compare the biodistribution of radioactivity and scintigraphic images in nude mice heterotransplanted with human cancerous pancreatic duct cells (Capan‐1) and in mice transplanted with murine tumor cells (B16 melanoma). Biodistribution studies showed that radioactivity was twice as high in the Capan‐1 xenograft after injection of the radiolabel than after injection of radiometal alone, and 34‐fold higher in the B16 tumor. On gamma‐scintigraphic imaging, the Capan‐1 tumor was just visible, whereas the B16 melanoma was clearly imaged. The lack of contrast of the Capan‐1 tumor compared with the B16 melanoma could be due to a poor vascularization. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
163.
Ren Ramasseul Pascale Maldivi Jean-Claude Marchon Mark Taylor Daniel Guillon 《Liquid crystals》1993,13(5):729-733
Several long chain esters of meso-tetrakis(para-carboxyphenyl)porphyrin, and two of their metal complexes (Cu, Zn) have been prepared and characterized. Each of them exhibits at least one thermotropic phase transition below the clearing point to the isotropic liquid, but no definitive evidence of liquid crystallinity has been found by differential scanning calorimetry, optical microscopy, or X-ray diffraction. 相似文献
164.
Guy Deniau Laurent Azoulay Pascale Jégou Gilles Le Chevallier Serge Palacin 《Surface science》2006,600(3):675-684
2-Butenenitrile belongs to the large family of electron deficient vinylic monomers that usually form 100 to 500 nm thick grafted polymer films by electroreduction. However, 2-butenenitrile exhibits a slightly acidic hydrogen atom on its CH3 group that inhibits the anionic polymerization usually observed with ‘classical’ organic monomers such as its isomer methacrylonitrile. 2-Butenenitrile thus gives nanometer thick grafted film by electroreduction, essentially composed of a mixture of monomers, dimers and trimers and in the same way, allows an easy observation by XPS of the chemical signature of the grafting, i.e. the carbon-to-nickel bond, observed at 283.6 eV. 相似文献
165.
Luigi De Pascale Aldo Pratelli 《Calculus of Variations and Partial Differential Equations》2002,14(3):249-274
In this paper we study the dimension of some measures which are related to the classical Monge's optimal mass transport problem
and are solutions of a scalar shape optimization problem. Moreover in the case of maximal dimension we will study the summability
of the associate densities.
Received: 16 November 2000 / Accepted: 4 December 2000 / Published online: 18 January 2002 相似文献
166.
Benzaid Mounir Minet Pascale Al Agha Khaldoun Adjih Cedric Allard Geraud 《Wireless Networks》2004,10(4):377-388
Trends in fourth generation (4G) wireless networks are clearly identified by the full-IP concept where all traffic (data, control, voice and video services, etc.) will be transported in IP packets. Many proposals are being made to enhance IP with the functionalities necessary to manage the mobility of nodes, so that networks can provide global seamless roaming between heterogeneous wireless and wired networks. In this paper, we focus on the management of universal mobility, including both large scale macro-mobility and local scale micro-mobility. We propose a hierachical architecture (i) extending micro-mobility management of a wireless access network to an ad-hoc access network, (ii) connecting this ad-hoc network to the Internet and (iii) integrating Mobile IP and OLSR, a routing protocol for ad-hoc networks, to manage universal mobility. This architecture is validated by an implementation based on DynamicsMobile-IP and OLSR version 7. We show how the brodcast of Mobile-IP Agent Advertisement can be optimized using OLSR MPR-flooding. 相似文献
167.
Asgatay S Petermann C Harakat D Guillaume D Taylor JS Clivio P 《Journal of the American Chemical Society》2008,130(38):12618-12619
Using the analogue of TpT methylated at the 3'-end N3 position (Tpm3T), we demonstrate that when the oxetane/(6-4) pathway is precluded, water addition occurs at the 3'-end C6 position of the oxetane intermediate to provide its opening. Photoreversal of this (6-4) photoproduct C6 hydrate brings the first experimental evidence that the (6-4) photolyase repair can proceed through an oxetane intermediate. 相似文献
168.
A. De Giacomo M. Dell''Aglio O. De Pascale R. Gaudiuso A. Santagata R. Teghil 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008,63(5):585-590
In this paper Laser Induced Breakdown Spectroscopy has been applied for determining the elemental composition of a set of ancient bronze artworks coming from archaeological site of Minervino Murge — Southern of Italy (dated around VII b.C.). Before carrying on the analysis of the archaeological samples, the characterization of the analytical technique has been accomplished by investigating the trueness of the typical assumptions adopted in LIBS, such as Local Thermodynamic Equilibrium, congruent ablation and plasma homogeneity. With this purpose, two different laser pulse durations, 7 ns and 350 fs, have been used. We have focused our attention on LIBS analysis of bronze standards by considering and discussing the bases of both methodology and analytical approach to be followed for the analysis of ancient copper-based-alloy samples. Unexpectedly, regardless from the laser pulse duration, the LIBS technique has shown, by considering an adequate approach on the emitting plasma features, that its peculiarities are anyway preserved so that a fast analysis of ancient copper-based-alloys can be achieved. After verifying the suitability of the methodology, it has been possible to fulfill the typical assumptions considered for the LIBS calibration curves method and use it for ancient bronze artworks analysis. 相似文献
169.
Erickson B DiMaggio SC Mullen DG Kelly CV Leroueil PR Berry SA Baker JR Orr BG Banaszak Holl MM 《Langmuir : the ACS journal of surfaces and colloids》2008,24(19):11003-11008
The interaction of generation 5 (G5) and 7 (G7) poly(amidoamine) (PAMAM) dendrimers with mica-supported Survanta bilayers is studied with atomic force microscopy (AFM). In these experiments, Survanta forms distinct gel and fluid domains with differing lipid composition. Nanoscale defects are induced by the PAMAM dendrimers. The positively charged dendrimers remove lipid from the fluid domains at a significantly greater rate than for the gel domains. Dendrimer accumulation on lipid edges and terraces preceding lipid removal has been directly imaged. Immediately following lipid removal, the mica surface is clean, indicating that lipid defects are not induced by dendrimers binding to the mica substrate and displacing the lipid. 相似文献
170.
Van Elslande E Guérineau V Thirioux V Richard G Richardin P Laprévote O Hussler G Walter P 《Analytical and bioanalytical chemistry》2008,390(7):1873-1879
Microsamples of pink cosmetic powders from the Greco–Roman period were analyzed using two complementary analytical approaches
for identification of the colouring agents (lake pigments originally manufactured from madder plants with an inert binder,
usually a metallic salt) present in the samples. The first technique was a methanolic acidic extraction of the archaeological
samples with an additional ethyl acetate extraction of the anthraquinone-type colouring agents which were identified using
high performance liquid chromatography coupled to electrospray ionization with high resolution mass spectrometry (LC–ESI–HRMS),
and the second was direct analysis of a microsample by laser desorption ionization–mass spectrometry (LDI–MS). The latter
technique is well suited when the quantity of samples is very low. This soft ionization technique enables the detection of
very small quantities of compounds using the combination of positive and negative-ion modes. It was also successfully applied
for the direct analysis of some laboratory-made reference compounds. However, the presence of lead in one of these ancient
samples induced a spectral suppression phenomenon. In this case and conditional on a sufficient quantity of available sample,
the former method is better adapted for the characterization of these anthraquinone-type molecules. This study also confirmed
that purpurin, munjistin, and pseudopurpurin are the principal colouring agents present in these ancient cosmetic powders
constituted from madder plants.
Presented at the Annual French National Symposium on Mass Spectrometry, Electrophoresis and Proteomics, 20–23 September 2007
in Pau, France. 相似文献