Journal De Physique Iv最新文献

{"title":"Miroirs pour l'UV lointain (VUV) entre 80 et 130 nm","authors":"F. Bridou, M. Cuniot-Ponsard, J. Desvignes","doi":"10.1051/JP4:2006138025","DOIUrl":"https://doi.org/10.1051/JP4:2006138025","url":null,"abstract":"Dans le domaine spectral entre 80 et 130 nm situe dans le VUV (\"Vacuum Ultra-Violet\"), les materiaux ne sont ni transparents, ni vraiment reflechissants. Il est difficile de realiser des systemes optiques et, en consequence, de determiner les constantes optiques des materiaux. Les ecarts entre la reflectivite calculee a partir des indices references dans les tables et la reflectivite experimentale nous ont conduits a penser que certains de ces indices n'etaient pas exacts. Nous avons developpe une methode experimentale de determination des constantes optiques a partir des mesures de reflectivite au voisinage de l'incidence normale, en fonction de la longueur d'onde. A partir des valeurs ainsi determinees, des composants tels que miroirs ou polariseurs peuvent etre concus et realises.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"38 1","pages":"225-230"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77240654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forcings and feedbacks by land ecosystem changes on climate change","authors":"R. Betts","doi":"10.1051/JP4:2006139009","DOIUrl":"https://doi.org/10.1051/JP4:2006139009","url":null,"abstract":"Vegetation change is involved in climate change through both forcing and feedback processes. Emissions of CO 2 from past net deforestation are estimated to have contributed approximately 0.22 -0.51 Wm -2 to the overall 1.46 Wm -2 radiative forcing by anthropogenic increases in CO 2 up to the year 2000. Deforestation-induced increases in global mean surface albedo are estimated to exert a radiative forcing of 0 to -0.2 Wm -2 , and dust emissions from land use may exert a radiative forcing of between approximately +0.1 and -0.2 Wm -2 . Changes in the fluxes of latent and sensible heat due to tropical deforestation are simulated to have exerted other local warming effects which cannot be quantified in terms of a Wm -2 radiative forcing, with the potential for remote effects through changes in atmospheric circulation. With tropical deforestation continuing rapidly, radiative forcing by surface albedo change may become less useful as a measure of the forcing of climate change by changes in the physical properties of the land surface. Although net global deforestation is continuing, future scenarios used for climate change prediction suggest that fossil fuel emissions of CO 2 may continue to increase at a greater rate than land use emissions and therefore continue to increase in dominance as the main radiative forcing. The CO 2 rise may be accelerated by up to 66% by feedbacks arising from global soil carbon loss and forest dieback in Amazonia as a consequence of climate change, and Amazon forest dieback may also exert feedbacks through changes in the local water cycle and increases in dust emissions.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"42 1","pages":"119-142"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84042711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Génération d'impulsions attosecondes isolées","authors":"É. Constant","doi":"10.1051/JP4:2006138002","DOIUrl":"https://doi.org/10.1051/JP4:2006138002","url":null,"abstract":"Nous generons des harmoniques d'ordres eleves en utilisant une impulsion femtoseconde intense dont la polarisation est modulee temporellement. Cette evolution rapide de la polarisation nous permet de confiner l'emission XUV dans l'intervalle temporel ou la polarisation de l'impulsion fondamentale est quasi-lineaire et de l'interdire partout ailleurs. En utilisant des impulsions ultracourtes dont la phase absolue est controlee, nous pouvons ainsi generer des impulsions attosecondes isolees accordables et de large bande spectrale.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"197 1","pages":"3-11"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73110298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Le pôle de métrologie de SOLEIL","authors":"M. Idir, Sylvain Brochet, Aurélien Delmotte, B. Lagarde, Pascal Mercère, T. Moreno, F. Polack, M. Thomasset","doi":"10.1051/JP4:2006138031","DOIUrl":"https://doi.org/10.1051/JP4:2006138031","url":null,"abstract":"Le Pole de METROLOGIE de SOLEIL a pour objet de creer sur le synchrotron SOLEIL, une plateforme constituee: • 'une ligne de lumiere utilisant le rayonnement synchrotron (metrologie dite a la longueur d'onde) • d'un laboratoire de metrologie associe (metrologie dite « classique ») Ces deux types de Metrologie sont l'une et l'autre indispensables pour soutenir l'activite de recherche instrumentale en optique X et X-UV. Ce projet de pole de METROLOGIE ne repondra pas seulement aux besoins des groupes charges de l'equipement du synchrotron SOLEIL en optiques et detecteurs mais aussi pour preparer, tester et mettre au point les postes experimentaux, ce qui concerne deja une large communaute d'utilisateurs. Il sera aussi largement ouvert, des sa mise en service, a l'ensemble de la communaute scientifique concernee par l'instrumentation X et XUV en Ile de France, en France, voire meme en Europe si la demande continue de croitre plus vite que l'offre dans ce domaine. Ligne de lumiere - Metrologie a la longueur d'onde La ligne de lumiere sera equipee de plusieurs stations permettant de mesurer, dans la plus grande partie du spectre couvert par le synchrotron, les parametres photometriques qui caracterisent les elements optiques, tels que: la reflectivite de surfaces, l'efficacite de diffraction des reseaux, la diffusion des surfaces ou l'efficacite des detecteurs X et X-UV et la calibration absolue. Cette installation pourra servir egalement a developper des instruments et des diagnostics necessaires a la caracterisation des faisceaux de rayons X (intensite, taille, degre de coherence, polarisation etc.) Metrologie Classique La metrologie des surfaces optiques est devenue une necessite critique pour les laboratoires et les industries qui utilisent les photons X et X-UV (synchrotrons, centres laser, etc..). En effet, les progres de calcul et de conception des systemes optiques pour ces longueurs d'onde (optiques de microfocalisation, monochromateurs, diagnostics d'imagerie) font que les performances de ces instruments sont desormais limitees par les imperfections de fabrication des composants optiques. La metrologie des surfaces optiques est donc une necessite imperieuse pour tous les acteurs du domaine, qui se doivent d'effectuer les controles appropries. Cette pression s'exerce aussi sur les moyens utilises pour effectuer ces mesures, car les incertitudes de mesure actuelles, notamment en ce qui concerne la regularite des surfaces, sont loin d'etre negligeables vis a vis des tolerances demandees. 11 est donc indispensable de faire evoluer les instruments de mesure et d'obtenir des gains significatifs de precision. Un travail particulier est en cours au laboratoire de Metrologie pour developper a cote des instruments commerciaux, des instruments prototypes sur des concepts originaux (mesures de profils de surface et mesures d'angle). Dans cet article, nous donnons des details des choix techniques utilises sur la ligne de METROLOGIE et TESTS et des perform","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"46 1","pages":"265-274"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74583315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilisation des matériaux luminescents pour la métrologie des faisceaux intenses UVX d'impulsions ultracourtes","authors":"N. Fedorov, Vitali Nagirnyi, Andrey N. Vasil’ev, A. Belsky, B. Carré, E. Feldbach, J. Gaudin, G. Geoffroy, S. Guizard, M. D. Grazia, Marco Kirm, P. Martin, H. Merdji","doi":"10.1051/JP4:2006138029","DOIUrl":"https://doi.org/10.1051/JP4:2006138029","url":null,"abstract":"Recemment nous avons debute des series d'experiences sur l'interaction d'impulsions intenses VUV avec les solides luminescents. Le but principal en est l'etude des mecanismes d'interaction et de transfert d'energie entre les excitations electrcniques dans les solides a large bande interdite. L'application directe de ces etudes sera le developpement de materiaux et de methodes de metrologie pour les faisceaux UVX intenses. Nous presentons les resultats obtenus pour CdWO 4 qui montrent que ce cristal pourra servir comme un scintillateur pour le rayonnement VUV intense.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"392 1","pages":"251-257"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75699370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Earth system analysis and the future of the biosphere","authors":"W. Lucht","doi":"10.1051/JP4:2006139010","DOIUrl":"https://doi.org/10.1051/JP4:2006139010","url":null,"abstract":"The global biosphere has begun to change fundamentally as a consequence of human actions. This change can be understood as a consequence of a major transition in the evolution of life on Earth, the emergence of human language, which opened up new pathways of biological information transmission. The challenge facing the humans species now is to not just suffer the consequences of this change, but to develop a science of Earth system analysis that will allow the collective, globally networked reflective capacity of humans to chart paths into the future that are sustainable. Global observation and computer modelling are important elements of this process. Such models for the biosphere predict large-scale reorganisation of the functional composition of the terrestrial biosphere under strong anthropogenic climate change. Considering the advent of humans and of global change on the background of the past evolution of life on Earth, it is obvious that the co-evolution between geosphere and biosphere that has characterised Earth history in the past has expanded to include the anthroposphere as a third interacting element.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"72 1","pages":"143-155"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72927945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser X-UV en schéma collisionnel OFI à 41,8 nm créé dans des tubes capillaires","authors":"G. Vieux, B. Cros, G. Maynard, Tomas Mocek, I. Bettaibi, M. Farinet, J. Dubau","doi":"10.1051/JP4:2006138006","DOIUrl":"https://doi.org/10.1051/JP4:2006138006","url":null,"abstract":"Nous presentons les resultats experimentaux et theoriques obtenus sur le laser X-UV a 41,8 nm cree en schema collisisonnel a ionisation par champ optique dans des tubes capillaires. Une etude detaillee a ete menee dans le but de comprendre les effets lies au guidage. Le plasma amplificateur est cree dans un tube capillaire de quelques cm de long. L'emission X-UV maximum est obtenue en fonctionnant en regime de guidage multimode dans un tube capillaire de 25 mm de long. Le signal X-UV mesure est 3 fois plus eleve que celui observe dans une cellule de gaz et la divergence du faisceau est reduite d'un facteur 3. Un code numerique, baptise COFIXE, est en developpement pour calculer le signal X-UV emis par le plasma amplificateur. Il inclut le calcul de la propagation du faisceau pompe, de l'etat du plasma juste apres l'interaction avec le faisceau pompe, le calcul de l'evolution des proprietes locales du plasma pendant les quelques ps suivantes ainsi que le calcul de l'amplification et du transport de l'emission X-UV. Un tres bon accord a ete obtenu entre les resultats experimentaux et les resultats theoriques pour plusieurs caracteristiques telles la divergence du faisceau, la correlation entre la transmission du faisceau pompe guide et l'energie du signal X-UV, ainsi que l'amelioration apportee par le guidage.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"3 1","pages":"43-53"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82021493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mécanismes d'éjection de particules par laser impulsionnel","authors":"David Grojo, A. Cros, P. Delaporte, Marc L. Sentis, Hervé Dubus, Roberto Mionetto","doi":"10.1051/JP4:2006138022","DOIUrl":"https://doi.org/10.1051/JP4:2006138022","url":null,"abstract":"L'enlevement de particules de dimensions nanometriques est l'un des principaux challenges a relever pour atteindre les futurs objectifs de l'industrie microelectronique. Les procedes laser presentent, dans certains cas, des performances tres interessantes, mais les mecanismes d'ejection des particules polluant la surface restent cependant fort mal connus. L'etude de la dynamique d'ejection des particules, par une technique optique, a mis en evidence l'existence de deux mecanismes dont l'importance relative depend de la fluence d'irradiation. A forte fluence l'ablation locale du substrat sous la particule predomine, alors que pour les fluences plus faibles le mecanisme semble etre lie a l'enlevement de l'humidite residuelle a l'interface particule - substrat. Contrairement aux modeles precedemment proposes, la contribution de la force d'inertie s'exercant sur la particule lors de l'expansion thermique rapide des materiaux est negligeable.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"7 1","pages":"191-201"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90476259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence and air$/$sea-exchange of novel organic pollutants in the marine environment","authors":"R. Ebinghaus, Z. Xie","doi":"10.1051/JP4:2006139016","DOIUrl":"https://doi.org/10.1051/JP4:2006139016","url":null,"abstract":"A number of studies have demonstrated that several classes of chemicals act as biologically relevant signalling substances. Among these chemicals, many, including PCBs, DDT and dioxins, are semi-volatile, persistent, and are capable of long-range atmospheric transport via atmospheric circulation. Some of these compounds, e.g. phthalates and alkylphenols (APs) are still manufactured and consumed worldwide even though there is clear evidence that they are toxic to aquatic organisms and can act as endocrine disruptors. Concentrations of NP, t-OP and NP1EO, DMP, DEP, DBP, BBP, and DEHP have been simultaneously determined in the surface sea water and atmosphere of the North Sea. Atmospheric concentrations of NP and t-OP ranged from 7 to 110 pg m −3 , which were one to three orders of magnitude below coastal atmospheric concentrations already reported. NP1EO was detected in both vapor and particle phases, which ranged from 4 to 50 pg m −3 . The concentrations of the phthalates in the atmosphere ranged from below the method detection limit to 3.4 ng m −3 . The concentrations of t-OP, NP, and NP1EO in dissolved phase were 13-300, 90-1400, and 17-1660 pg L −1 . DBP, BBP, and DEHP were determined in the water phase with concentrations ranging from below the method detection limit to 6.6 ng L −1 . This study indicates that atmospheric deposition of APs and phthalates into the North Sea is an important input pathway. The net fluxes indicate that the air-sea exchange is significant and, consequently the open ocean and polar areas will be an extensive sink for APs and phthalates.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"1 1","pages":"211-237"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91061973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optiques multicouches EUV","authors":"Julien Gautier, F. Delmotte, F. Bridou, M. Rouillay, Françoise Varniere, S. D. Rossi, Arnaud Jérôme","doi":"10.1051/JP4:2006138027","DOIUrl":"https://doi.org/10.1051/JP4:2006138027","url":null,"abstract":"L'elaboration de nouveaux revetements interferentiels multicouches est motivee par la demande de l'astrophysique solaire et par le developpement de nouvelles sources de rayonnement EUV (source a generation d'harmoniques d'ordre eleve, laser X, rayonnement synchrotron). Nous avons etudie et developpe differents systemes multicouches possedant a la fois des proprietes optiques optimisees (reflectivite et/ou bande passante) et une bonne stabilite temporelle et thermique pour la gamme de longueurs d'onde comprise entre λ. = 30nm et λ = 50nm. Une augmentation significative de la reflectivite des multicouches dans la gamme spectrale de 30 a 40nm a ete obtenue par l'addition d'un troisieme materiau dans l'empilement. Une etude comparative des courbes de reflectivites theorique et experimentale en fonction de la longueur d'onde a ete menee. Les differences observees ont pu etre expliquees notamment a l'aide de l'analyse des proprietes physiques des differents materiaux en couche mince. Nous montrons egalement que l'utilisation de ces multicouches a trois materiaux par periode permet le developpement d'empilements repondant a des demandes specifiques (miroirs a large bande passante, miroirs a double bande). Pour les longueurs d'ondes comprises entre 35 nm et 50nm nous avons developpe des multicouches a base de scandium. Cette etude a permis d'obtenir des multicouches avec de forts pouvoirs reflecteurs et une bonne stabilite temporelle. La stabilite de ces empilements a pu etre amelioree a l'aide de l'insertion aux interfaces de couches barrieres.","PeriodicalId":14838,"journal":{"name":"Journal De Physique Iv","volume":"41 1","pages":"237-244"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83255528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}