Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and ...

The University of Sydney

In this study, the new technique of transmission Kikuchi diffraction (TKD) in the scanning electron microscope (SEM) has been applied for the first time to enable orientation mapping of bulk, nanostructured metals. The results show how the improved spatial resolution of SEM-TKD, compared to conventional EBSD, enables reliable mapping of truly nanostructured metals and alloys, with mean grain sizes in the 40-200 nm range. The spatial resolution of the technique is significantly below 10nm, and contrasting examples are shown from both dense (Ni) and lighter (Al-alloy) materials. Despite the burden of preparing thin, electron-transparent samples, orientation mapping using SEM-TKD is likely to become invaluable for routine characterisation of nanocrystalline and, potentially, highly deformed microstructures.

Orientation mapping of nanostructured materials using transmission Kikuchi diffraction in the scanning electron microscope.

We describe the first occurrence in the fossil record of an aquatic avian twig-nest with five eggs in situ (Early Miocene Tudela Formation, Ebro Basin, Spain). Extensive outcrops of this formation reveal autochthonous avian osteological and oological fossils that represent a single taxon identified as a basal phoenicopterid. Although the eggshell structure is definitively phoenicopterid, the characteristics of both the nest and the eggs are similar to those of modern grebes. These observations allow us to address the origin of the disparities between the sister taxa Podicipedidae and Phoenicopteridae crown clades, and traces the evolution of the nesting and reproductive environments for phoenicopteriforms.

The first occurrence in the fossil record of an aquatic avian twig-nest with Phoenicopteriformes eggs: evolutionary implications.

&#x822A;&#x6D77;&#x8005;&#x58F3;&#x9499;&#x5316;&#x662F;&#x72EC;&#x4E00;&#x65E0;&#x4E8C;&#x7684;&#x3002;&#x53EA;&#x5BF9;&#x5973;&#x6027;&#x7684;&#x8FD9;&#x4E9B;&#x5934;&#x8DB3;&#x7C7B;&#x6784;&#x9020;&#x7EB8;&#x9E66;&#x9E49;&#x87BA;&#x53F7;&#x7684;&#x5916;&#x58F3;&#xFF0C;&#x800C;&#x7528;&#x4F5C;&#x5F00;&#x53D1;&#x6D77;&#x6D0B;&#x6C34;&#x5C42;&#x4E2D;&#x7684;&#x80DA;&#x80CE;&#x7684;&#x80B2;&#x96CF;&#x5BA4;&#x3002;&#x4F5C;&#x4E3A;&#x4E00;&#x4E2A;&#x6700;&#x8584; &#xFF08;225 &mu; m&#xFF09; &#x5DF2;&#x77E5;&#x6210;&#x4EBA;&#x8F6F;&#x4F53;&#x52A8;&#x7269;&#x58F3;&#x548C;&#x7F3A;&#x4E4F;&#x8749;&#x8715;&#x6837;&#x5916;&#x9632;&#x62A4;&#x7F69;&#xFF0C;&#x8FD9;&#x79CD;&#x58F3;&#x53EF;&#x80FD;&#x5BB9;&#x6613;&#x53D7;&#x89E3;&#x6563;&#x4F5C;&#x4E3A;&#x6D77;&#x6D0B;&#x53D8;&#x6696;&#x548C; ph &#x503C;&#x7684;&#x964D;&#x4F4E;&#x3002;A.&#x7ED3;&#x8282;&#x58F3;&#x6F0F;&#x6D1E;&#x901A;&#x8FC7;&#x6D78;&#x6CE1;&#x7684;&#x8D1D;&#x58F3;&#x788E;&#x7247;&#x7684;&#x63A7;&#x5236;&#x7EFC;&#x5408;&#x5B9E;&#x9A8C;&#x4E2D;&#x8FDB;&#x884C;&#x4E86;&#x8C03;&#x67E5; (19 &deg; C/pH 8.1 &#xFF1B; &Omega;(Ca) &#xFF1B; pCO(2) 419 = 4.23) &#x548C;&#x8FD1;&#x671F;&#x6761;&#x4EF6; (24 &deg; C/pH 7.8 7.6 pCO(2) 932-1525 &#xFF1B; &Omega;(Ca) = 2.72 1.55) &#x4E3A; 14 &#x5929;&#x3002;&#x66F4;&#x591A;&#x6781;&#x7AEF; ph &#x503C;&#x5904;&#x7406; (pH 7.4 7.2 &#xFF1B; &Omega;(Ca) &#xFF1B; pCO(2) 2454 3882 = 1.20-0.67&#xFF09; &#x88AB;&#x7528;&#x6765;&#x8BC4;&#x4F30;&#x4E2D;&#x58F3;&#x6EB6;&#x89E3;&#x7684;&#x5F15;&#x7206;&#x70B9;&#x3002;X &#x5C04;&#x7EBF;&#x884D;&#x5C04;&#x8868;&#x660E;&#x77FF;&#x7269;&#x5B66;&#x4E4B;&#x95F4;&#x672A;&#x7ECF;&#x5904;&#x7406;&#x548C;&#x5904;&#x7406;&#x70AE;&#x5F39;&#x6CA1;&#x6709;&#x53D8;&#x5316;&#x3002;&#x51CF;&#x5C11;&#x7684;&#x5916;&#x58F3;&#x91CD;&#x91CF;&#x5206;&#x89E3;&#x4EA7;&#x751F;&#x5F88;&#x660E;&#x663E;&#x5728; pH 7.8 (&#x9884;&#x8BA1; 2070&#x5E74;) 14 &#x5929;&#x540E;&#x5728;&#x63A7;&#x5236;&#x6E29;&#x5EA6;&#x8F83;&#x6B63;&#x5E38;&#x6E29;&#x6696;&#x53CA;&#x8F83;&#x4F4E;&#x7684; ph &#x503C;&#x6CBB;&#x7597;&#x589E;&#x52A0;&#x6EB6;&#x51FA;&#x5EA6;&#x4E0E;&#x5B75;&#x80B2;&#x7684;&#x8D1D;&#x58F3;&#x3002;&#x5728; 24 &deg; C (&#x9884;&#x8BA1;&#x5230; 2100 &#x5E74;&#x5F53;&#x5730;&#x6C34;&#x57DF;&#xFF09;&#xFF0C;&#x8DE8;&#x6240;&#x6709;&#x4F4E; pH &#x5904;&#x7406;&#x63A7;&#x5236;&#x6E29;&#x5EA6;&#x76F8;&#x6BD4;&#x5F55;&#x5F97;&#x6700;&#x5927;&#x6EB6;&#x51FA;&#x3002;&#x626B;&#x63CF;&#x7535;&#x955C;&#x89C2;&#x5BDF;&#x53D1;&#x73B0;&#x89E3;&#x6563;&#x548C;&#x8680;&#x523B;&#x7684;&#x58F3;&#x77FF;&#x7269;&#x5728;&#x5B9E;&#x9A8C;&#x6027;&#x6CBB;&#x7597;&#x3002;&#x6CA1;&#x6709;&#x8865;&#x507F;&#x6210;&#x77FF;&#x4F5C;&#x7528;&#x7684;&#x60C5;&#x51B5;&#x4E0B;&#xFF0C;&#x5728;&#x53D1;&#x73B0;&#x5973;&#x6027;&#x7E41;&#x6B96;&#x5206;&#x5EAD;&#x5C06;&#x5BB9;&#x6613;&#x6EB6;&#x51FA;&#xFF0C;&#x968F;&#x7740;&#x6D77;&#x6D0B; ph &#x503C;&#x7684;&#x4E0B;&#x964D;&#x3002;&#x7531;&#x4E8E; shell &#x662F;&#x8FDB;&#x5316;&#x7684;&#x822A;&#x6D77;&#x8005;&#x7684; holopelagic &#x5B58;&#x5728;&#x5173;&#x952E;&#x9002;&#x5E94;&#xFF0C;A.&#x7ED3;&#x8282;&#x6027;&#x7684;&#x6301;&#x7EED;&#x5B58;&#x5728;&#x53EF;&#x80FD;&#x53D7;&#x5230;&#x58F3;&#x6EB6;&#x89E3;&#x5728;&#x6D77;&#x6D0B;&#x53D8;&#x5316;&#x7684;&#x4E16;&#x754C;&#x4E2D;&#x3002;

&#x7EB8;&#x9E66;&#x9E49;&#x87BA; (Argonauta &#x7ED3;&#x8282;) &#x58F3;&#x6613;&#x53D7;&#x6C14;&#x5019;&#x53D8;&#x5316;&#x6D77;&#x6D0B;&#xFF1A; &#x6F5C;&#x5728;&#x7684;&#x6EB6;&#x51FA;&#x5EA6;&#x7684;&#x706D;&#x7EDD;&#x3002;

Shell calcification in argonauts is unique. Only females of these cephalopods construct the paper nautilus shell, which is used as a brood chamber for developing embryos in the pelagic realm. As one of the thinnest (225 Î¼m) known adult mollusc shells, and lacking an outer protective periostracum-like cover, this shell may be susceptible to dissolution as the ocean warms and decreases in pH. Vulnerability of the A. nodosa shell was investigated through immersion of shell fragments in multifactorial experiments of control (19 Â°C/pH 8.1; pCO(2) 419; Î©(Ca) = 4.23) and near-future conditions (24 Â°C/pH 7.8-7.6; pCO(2) 932-1525; Î©(Ca) = 2.72-1.55) for 14 days. More extreme pH treatments (pH 7.4-7.2; pCO(2) 2454-3882; Î©(Ca) = 1.20-0.67) were used to assess tipping points in shell dissolution. X-ray diffractometry revealed no change in mineralogy between untreated and treated shells. Reduced shell weight due to dissolution was evident in shells incubated at pH 7.8 (projected for 2070) after 14 days at control temperature, with increased dissolution in warmer and lower pH treatments. The greatest dissolution was recorded at 24 Â°C (projected for local waters by 2100) compared to control temperature across all low-pH treatments. Scanning electron microscopy revealed dissolution and etching of shell mineral in experimental treatments. In the absence of compensatory mineralization, the uncovered female brood chamber will be susceptible to dissolution as ocean pH decreases. Since the shell was a crucial adaptation for the evolution of the argonauts' holopelagic existence, persistence of A. nodosa may be compromised by shell dissolution in an ocean-change world.

Vulnerability of the paper Nautilus (Argonauta nodosa) shell to a climate-change ocean: potential for extinction by dissolution.

Calcification de la coquille des Argonautes est unique. Seules les femelles de ces c&eacute;phalopodes construisent la coquille de Nautile de papier, ce qui est utilis&eacute;e comme une poche incubatrice pour d&eacute;velopper des embryons dans le domaine p&eacute;lagique. Comme l&#39;un du plus mince (225 &mu;m) connu des coquilles de mollusques adultes et manque un couvercle ext&eacute;rieur de p&eacute;riostracum-comme protecteur, cette coquille peut-&ecirc;tre &ecirc;tre sensible &agrave; la dissolution qui lorsque l&#39;oc&eacute;an se r&eacute;chauffe et diminue en pH. Vuln&eacute;rabilit&eacute; de l&#39;interpr&eacute;teur de commandes a. nodosa a &eacute;t&eacute; &eacute;tudi&eacute;e par immersion des fragments de coquilles dans des exp&eacute;riences de contr&ocirc;le multifactorielles (19 &deg; C/pH 8,1 ; pCO(2) 419 ; &Omega;(Ca) = 4,23) et les conditions du futur proche (24 &deg; C/pH 7,8-7,6 ; pCO(2) 932-1525 ; &Omega;(Ca) = 2.72-1,55) pendant 14 jours. Plus les traitements extr&ecirc;mes de pH (pH 7,4 et 7,2 ; pCO(2) 2454-3882 ; &Omega;(Ca) = 1.20-0,67) ont &eacute;t&eacute; utilis&eacute;es pour &eacute;valuer les points de non-retour dans la dissolution de la coquille. La diffractom&eacute;trie de rayons x a r&eacute;v&eacute;l&eacute; aucun changement dans la min&eacute;ralogie entre les coques non trait&eacute;s et trait&eacute;s. Poids coque r&eacute;duite en raison de la dissolution &eacute;tait &eacute;vidente dans les coquilles incub&eacute;es &agrave; pH 7,8 (projet&eacute; pour 2070) apr&egrave;s 14 jours &agrave; la temp&eacute;rature de r&eacute;gulation, avec dissolution accrue dans les traitements de pH plus chaud et plus faible. La plus grande dissolution a &eacute;t&eacute; enregistr&eacute;e &agrave; 24 &deg; C (pr&eacute;vu pour les eaux locales en 2100) compar&eacute; &agrave; la temp&eacute;rature de r&eacute;gulation dans tous les traitements de pH faible. Microscopie &eacute;lectronique a r&eacute;v&eacute;l&eacute; la dissolution et la gravure de min&eacute;ral de coquille dans les traitements exp&eacute;rimentaux. En l&#39;absence de min&eacute;ralisation compensatoire, la d&eacute;couverte poche incubatrice femelle seront sensible &agrave; la dissolution comme oc&eacute;an pH diminue. La coquille &eacute;tant une adaptation cruciale pour l&#39;&eacute;volution de l&#39;existence de holopelagic des Argonautes, persistance d&#39;a. nodosa peut &ecirc;tre compromise par la dissolution de la coquille dans un monde oc&eacute;an-changement.

Vuln&eacute;rabilit&eacute; de la coquille de Nautile papier (Argonauta nodosa) &agrave; un oc&eacute;an de changement climatique : risque d&#39;extinction par dissolution.

Schale Verkalkung im Argonauten ist einzigartig. Nur die Weibchen diese Kopff&uuml;&szlig;ern konstruieren die Papier-Meeresschnecke, die als eine Brut-Kammer verwendet wird, f&uuml;r die Entwicklung von Embryonen im pelagischen Reich. Als eines der d&uuml;nnsten (225 &mu;m) bekannte Erwachsene Molluske Shells und fehlt eine &auml;u&szlig;ere Schutzh&uuml;lle Periostracum-wie, diese Shell m&ouml;glicherweise anf&auml;llig f&uuml;r Aufl&ouml;sung wie das Meer erw&auml;rmt und in den pH-Wert nimmt. Schwachstelle der A. Nodosa Shell wurde untersucht durch Eintauchen der Schale Fragmente in multifaktoriell Experimente des Steuerelements (19 &deg; C/pH 8,1; pCO(2) 419; &Omega;(Ca) = 4.23) und in naher Zukunft Bedingungen (24 &deg; C/pH 7,8-7,6; pCO(2) 932-1525; &Omega;(Ca) = 2.72-1,55) f&uuml;r 14 Tage. Mehr extreme pH-Wert-Behandlungen (pH 7,4-7.2; pCO(2) 2454-3882; &Omega;(Ca) = 1.20-0.67) wurden zur Abkippstellen in Schale Aufl&ouml;sung zu beurteilen. R&ouml;ntgen-diffraktometrischen ergab keine &Auml;nderung in der Mineralogie zwischen unbehandelten und behandelten Schalen. Reduzierte Schale Gewicht durch Aufl&ouml;sung zeigte sich in Schalen bei pH 7,8 (geplant f&uuml;r 2070) nach 14 Tagen bei Steuerung Temperatur, erh&ouml;hte Aufl&ouml;sung in w&auml;rmeren und niedrigeren pH Behandlungen inkubiert. Aufgenommen wurde die gr&ouml;&szlig;te Aufl&ouml;sung bei 24 &deg; C (f&uuml;r lokale Gew&auml;sser bis zum Jahr 2100 projiziert) im Vergleich zur Temperatur Kontrolle &uuml;ber alle Low-pH-Behandlungen. Raster-Elektronenmikroskopie aufgedeckt Aufl&ouml;sung und Radierung Schale Mineralwasser in experimentelle Behandlungen. Keine kostendeckende Mineralisierung werden die ungedeckte weibliche Brut-Kammer anf&auml;llig f&uuml;r Aufl&ouml;sung Ozean pH-Wert sinkt. Da die Shell eine entscheidende Anpassung f&uuml;r die Evolution der Argonauten Holopelagic Existenz war, kann fortbestehen A. Nodosa Schale aufgel&ouml;st in einer Welt der Ozean-&Auml;nderung beeintr&auml;chtigt werden.

Anf&auml;lligkeit von Papier-Meeresschnecke (Argonauta Nodosa) f&uuml;r einen Klimawandel Ozean: Potenzial f&uuml;r Aussterben durch Aufl&ouml;sung.

Calcificazione Shell in Argonauti &egrave; unica. Solo le femmine di questi cefalopodi costruiscono la conchiglia nautilus di carta, che &egrave; usata come una camera di covata per lo sviluppo di embrioni nel Regno pelagico. Come uno della pi&ugrave; sottile (225 &mu;m) noto conchiglie dei molluschi adulti e manca un coperchio protettivo esterno di periostracum-come, questo guscio pu&ograve; essere suscettibile di scioglimento come l&#39;oceano si scalda e diminuisce in pH. Vulnerabilit&agrave; della shell a. nodosa &egrave; stata studiata mediante immersione dei frammenti di guscio in esperimenti multifattoriali di controllo (19 &deg; C/pH 8.1; pCO(2) 419; &Omega;(Ca) = 4.23) e le condizioni del prossimo futuro (24 &deg; C/pH 7,6 7,8; pCO(2) 932-1525; &Omega;(Ca) = 2,72-1,55) per 14 giorni. Ulteriori trattamenti estremi di pH (pH 7,2-7,4; pCO(2) 2454-3882; &Omega;(Ca) = 1,20-0,67) sono stati utilizzati per valutare i punti di ribaltamento nella dissoluzione del guscio. Difrattometria a raggi x ha rivelato alcun cambiamento nella mineralogia tra conchiglie trattate e non trattate. Shell ridotto peso a causa della dissoluzione era evidente nelle conchiglie incubati a pH 7,8 (proiettato per 2070) dopo 14 giorni a temperatura di controllo, con maggiore dissoluzione nei trattamenti di pH pi&ugrave; basso e pi&ugrave; caldo. La dissoluzione pi&ugrave; grande &egrave; stata registrata a 24 &deg; C (previsto per le acque locali entro il 2100) rispetto al controllo temperatura attraverso tutti i trattamenti di basso-pH. Microscopia elettronica a scansione rivel&ograve; dissoluzione e acquaforte del minerale shell in trattamenti sperimentali. In assenza di mineralizzazione compensativa, la camera di covata femmina scoperta sar&agrave; suscettibile di scioglimento come pH oceano diminuisce. Dal momento che la shell era un adattamento cruciale per l&#39;evoluzione dell&#39;esistenza di holopelagic dei Argonauti, persistenza di a. nodosa pu&ograve; essere compromessa dalla dissoluzione del guscio in un mondo oceano-cambiamento.

Vulnerabilit&agrave; della shell carta Nautilus (Argonauta nodosa) a un oceano di cambiamento climatico: potenziale per estinzione di dissoluzione.

&#x30A2;&#x30EB;&#x30B4;&#x30CA;&#x30A6;&#x30BF;&#x30A4;&#x306E;&#x30B7;&#x30A7;&#x30EB;&#x306E;&#x77F3;&#x7070;&#x5316;&#x306F;&#x30E6;&#x30CB;&#x30FC;&#x30AF;&#x3067;&#x3059;&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;&#x982D;&#x8DB3;&#x985E;&#x306E;&#x5973;&#x6027;&#x3060;&#x3051;&#x304C;&#x80B2;&#x623F;&#x3068;&#x3057;&#x3066;&#x9060;&#x6D0B;&#x57DF;&#x306B;&#x304A;&#x3051;&#x308B;&#x521D;&#x671F;&#x80DA;&#x306E;&#x4F7F;&#x7528;&#x7D19;&#x30AA;&#x30A6;&#x30E0;&#x30AC;&#x30A4;&#x306E;&#x6BBB;&#x306F;&#x3001;&#x69CB;&#x7BC9;&#x3057;&#x307E;&#x3059;&#x3002;&#x6700;&#x8584; (225 &mu;) &#x306E; 1 &#x3064;&#x3068;&#x3057;&#x3066;&#x3001;&#x6D77;&#x3092;&#x6E29;&#x3081;&#x3057;&#x3001;pH &#x306E;&#x4F4E;&#x4E0B;&#x3068;&#x30A2;&#x30C0;&#x30EB;&#x30C8;&#x8EDF;&#x4F53;&#x52D5;&#x7269;&#x6BBB;&#x3068;&#x3001;&#x5916;&#x5074;&#x306E;&#x6BBB;&#x306E;&#x3088;&#x3046;&#x306A;&#x9632;&#x8B77;&#x6B20;&#x3051;&#x3066;&#x3044;&#x308B;&#x77E5;&#x3089;&#x308C;&#x3066;&#x3044;&#x308B;&#x3001;&#x3053;&#x306E;&#x30B7;&#x30A7;&#x30EB;&#x6EB6;&#x89E3;&#x306B;&#x5F71;&#x97FF;&#x3092;&#x53D7;&#x3051;&#x3084;&#x3059;&#x3044;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x3002;A. &#x7D50;&#x7BC0;&#x6027;&#x30B7;&#x30A7;&#x30EB;&#x306E;&#x8106;&#x5F31;&#x6027;&#x306F;&#x591A;&#x56E0;&#x5B50;&#x5B9F;&#x9A13;&#x5236;&#x5FA1;&#x306E;&#x30B7;&#x30A7;&#x30EB; &#x30D5;&#x30E9;&#x30B0;&#x30E1;&#x30F3;&#x30C8;&#x306E;&#x6D78;&#x6F2C;&#x3092;&#x884C;&#x3063;&#x305F; &#xFF08;19 &deg; C/pH 8.1; pCO(2) 419 &Omega;(Ca) 4.23 =&#xFF09; &#x3068;&#x8FD1;&#x3044;&#x5C06;&#x6765;&#x306E;&#x6761;&#x4EF6; (24 &deg; C/pH 7.8 7.6; pCO(2) 932-1525; &Omega;(Ca) = 2.72 1.55) 14 &#x65E5;&#x9593;&#x3002;&#x591A;&#x304F;&#x306E;&#x6975;&#x7AEF;&#x306A; pH &#x306E;&#x6CBB;&#x7642; (pH 7.4 7.2; pCO(2) 2454-3882; &Omega;(Ca) = 1.20 0.67) &#x30B7;&#x30A7;&#x30EB;&#x89E3;&#x6563;&#x306B;&#x8EE2;&#x63DB;&#x70B9;&#x3092;&#x8A55;&#x4FA1;&#x3059;&#x308B;&#x305F;&#x3081;&#x306B;&#x4F7F;&#x7528;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;X &#x7DDA;&#x56DE;&#x6298;&#x306F;&#x3001;&#x672A;&#x6CBB;&#x7642;&#x306E;&#x30B7;&#x30A7;&#x30EB;&#x9271;&#x7269;&#x7D44;&#x6210;&#x306E;&#x5909;&#x5316;&#x3092;&#x660E;&#x3089;&#x304B;&#x306B;&#x3002;&#x6EB6;&#x89E3;&#x306B;&#x3088;&#x308B;&#x4F4E;&#x4E0B;&#x30B7;&#x30A7;&#x30EB;&#x91CD;&#x91CF;&#x306F; ph (2070&#x5E74;&#x4E88;&#x60F3;) 7.8 14 &#x65E5;&#x5F8C;&#x5236;&#x5FA1;&#x6E29;&#x5EA6;&#x3067;&#x6EB6;&#x89E3;&#x304C;&#x5897;&#x52A0;&#x3067;&#x6696;&#x304B;&#x304F;&#x3001;&#x4E0B;&#x306E; ph &#x3092;&#x30A4;&#x30F3;&#x30AD;&#x30E5;&#x30D9;&#x30FC;&#x30C8; &#x30B7;&#x30A7;&#x30EB;&#x3067;&#x660E;&#x3089;&#x304B;&#x306B;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x6700;&#x5927;&#x306E;&#x6EB6;&#x89E3;&#x6E29;&#x5EA6;&#x9593;&#x3067;&#x306E;&#x3059;&#x3079;&#x3066;&#x306E;&#x4F4E; pH &#x6CBB;&#x7642;&#x3068;&#x6BD4;&#x8F03;&#x3057;&#x3066; 24 &deg; &#xFF08;&#x5730;&#x5143;&#x306E;&#x6C34;&#x306F; 2100 &#x5E74;&#x307E;&#x3067;&#x306B;&#x4E88;&#x5B9A;&#xFF09; C &#x3067;&#x8A18;&#x9332;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x8D70;&#x67FB;&#x96FB;&#x5B50;&#x9855;&#x5FAE;&#x93E1;&#x89B3;&#x5BDF;&#x6EB6;&#x89E3;&#x3068;&#x30A8;&#x30C3;&#x30C1;&#x30F3;&#x30B0; &#x30B7;&#x30A7;&#x30EB;&#x4E2D;&#x306E;&#x9271;&#x7269;&#x306E;&#x5B9F;&#x9A13;&#x7684;&#x306A;&#x6CBB;&#x7642;&#x3092;&#x660E;&#x3089;&#x304B;&#x306B;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;&#x6D77;&#x6D0B;&#x306E; pH &#x304C;&#x6E1B;&#x5C11;&#x3059;&#x308B;&#x3068;&#x4EE3;&#x511F;&#x9271;&#x5316;&#x4F5C;&#x7528;&#x304C;&#x306A;&#x3044;&#x5834;&#x5408;&#x306F;&#x3001;&#x660E;&#x3089;&#x304B;&#x306B;&#x5973;&#x6027;&#x80B2;&#x623F;&#x89E3;&#x6563;&#x306B;&#x654F;&#x611F;&#x3067;&#x3042;&#x308A;&#x307E;&#x3059;&#x3002;&#x30B7;&#x30A7;&#x30EB; &#x30A2;&#x30EB;&#x30B4;&#x30CA;&#x30A6;&#x30BF;&#x30A4;&#x306E; holopelagic &#x5B58;&#x5728;&#x306E;&#x9032;&#x5316;&#x306E;&#x305F;&#x3081;&#x306E;&#x91CD;&#x8981;&#x306A;&#x9069;&#x5FDC;&#x3060;&#x3063;&#x305F;&#x306E;&#x3067;&#x3001;A. &#x7D50;&#x7BC0;&#x6027;&#x306E;&#x6C38;&#x7D9A;&#x6027;&#x30B7;&#x30A7;&#x30EB;&#x89E3;&#x6563;&#x6D77;&#x6D0B;&#x5909;&#x52D5;&#x306E;&#x4E16;&#x754C;&#x3067;&#x306B;&#x3088;&#x3063;&#x3066;&#x7834;&#x3089;&#x308C;&#x308B;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x3002;

&#x6C17;&#x5019;&#x5909;&#x52D5;&#x306E;&#x6D77;&#x306B;&#x7D19;&#x30CE;&#x30FC;&#x30C1;&#x30E9;&#x30B9; (&#x30BF;&#x30B3;&#x30D6;&#x30CD;&#x985E;&#x7D50;&#x7BC0;) &#x30B7;&#x30A7;&#x30EB;&#x306E;&#x8106;&#x5F31;&#x6027;: &#x89E3;&#x6563;&#x306B;&#x3088;&#x3063;&#x3066;&#x6D88;&#x6EC5;&#x306E;&#x53EF;&#x80FD;&#x6027;&#x3002;

&#xC178; &#xD68C;&#xD654; argonauts&#xC5D0; &#xB3C5;&#xD2B9;&#xD569;&#xB2C8;&#xB2E4;. &#xC774;&#xB4E4;&#xC774; cephalopods&#xC758; &#xC554;&#xCEF7;&#xB9CC; &#xBE0C;&#xB8E8; &#xB4DC; &#xCC54;&#xBC84;&#xB85C; &#xC6D0;&#xC591; &#xC601;&#xC5ED;&#xC5D0; &#xBC30;&#xC544;&#xB97C; &#xAC1C;&#xBC1C; &#xD558;&#xB294; &#xB370; &#xC0AC;&#xC6A9; &#xB418;&#xB294; &#xC885;&#xC774; &#xB178;&#xD2F8;&#xB7EC;&#xC2A4; &#xC178;&#xC744; &#xC0DD;&#xC131; &#xD569;&#xB2C8;&#xB2E4;. &#xAC00;&#xC7A5; &#xC587;&#xC740; (225 &mu;) &#xC911; &#xD558;&#xB098;&#xB85C; &#xC54C;&#xB824;&#xC9C4; &#xC131;&#xC778; mollusc &#xD3EC;&#xD0C4; &#xBC0F; &#xC678;&#xBD80; &#xBCF4;&#xD638; periostracum &#xAC19;&#xC740; &#xCEE4;&#xBC84; &#xBD80;&#xC871;,&#xC774; &#xAECD;&#xC9C8;&#xC5D0; &#xCDE8;&#xC57D; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4; &#xD574;&#xC0B0; &#xBC14;&#xB2E4;&#xB97C; &#xB530;&#xB73B;&#xD558;&#xAC8C; &#xD558; &#xACE0; pH &#xAC10;&#xC18C;. A. nodosa &#xC178; &#xCDE8;&#xC57D;&#xC810;&#xC740; &#xCEE8;&#xD2B8;&#xB864;&#xC758; multifactorial &#xC2E4;&#xD5D8;&#xC5D0;&#xC11C; &#xD3EC;&#xD0C4; &#xD30C;&#xD3B8;&#xC758; &#xCE68;&#xC218;&#xB97C; &#xD1B5;&#xD574; &#xC870;&#xC0AC; (19 &deg; C/pH 8.1; pCO(2) 419; &Omega;(Ca) = 4.23)&#xC640; &#xAC00;&#xAE4C;&#xC6B4; &#xBBF8;&#xB798;&#xC758; &#xC870;&#xAC74; (24 &deg; C/pH 7.8-7.6; 932-1525 pCO(2); &Omega;(Ca) = 2.72 1.55) 14 &#xC77C; &#xB3D9;&#xC548;. &#xB354; &#xADF9;&#xB2E8;&#xC801;&#xC778; pH &#xCE58;&#xB8CC; (pH 7.4 7.2; pCO(2) 2454-3882; &Omega;(Ca) = 1.20 0.67) &#xC258; &#xD574;&#xC0B0; &#xD2F0;&#xD551; &#xD3EC;&#xC778;&#xD2B8;&#xB97C; &#xD3C9;&#xAC00; &#xD558;&#xB294; &#xB370; &#xC0AC;&#xC6A9; &#xD588;&#xB2E4;. X-&#xC120; diffractometry &#xAD11;&#xBB3C; &#xD559; &#xCE58;&#xB8CC; &#xBC0F; &#xCE58;&#xB8CC; &#xAECD;&#xC9C8; &#xC0AC;&#xC774;&#xC5D0;&#xC11C; &#xBCC0;&#xD654;&#xAC00; &#xB098;&#xD0C0;&#xB0AC;&#xB2E4;. &#xD574;&#xC0B0;&#xC73C;&#xB85C; &#xC778;&#xD574; &#xAC10;&#xC18C; &#xB41C; &#xD3EC;&#xD0C4; &#xBB34;&#xAC8C; pH 7.8 (2070 &#xC608;&#xC0C1;) 14 &#xC77C; &#xD6C4; &#xC81C;&#xC5B4; &#xC628;&#xB3C4;&#xC5D0;&#xC11C; &#xB354; &#xC628;&#xB09C; &#xD558; &#xACE0; &#xB0AE;&#xC740; &#xC0B0;&#xB3C4; &#xCE58;&#xB8CC; &#xC99D;&#xAC00; &#xD574;&#xC0B0;&#xC73C;&#xB85C;&#xC5D0;&#xC11C; incubated &#xD3EC;&#xD0C4;&#xC5D0; &#xBD84;&#xBA85; &#xD588;&#xB2E4;. &#xAC00;&#xC7A5; &#xD070; &#xD574;&#xC0B0; 24 &#x2103; (2100&#xC5D0; &#xC758;&#xD574; &#xC9C0;&#xC5ED; &#xD574; &#xC5ED;&#xC5D0; &#xB300; &#xD55C; &#xC608;&#xC0C1;) &#xD2B8;&#xB9AC; &#xD2B8; &#xBA3C; &#xD2B8; &#xBAA8;&#xB4E0; &#xB0AE;&#xC740; Ph&#xC5D0; &#xAC78;&#xCCD0; &#xC81C;&#xC5B4; &#xC628;&#xB3C4;&#xC5D0; &#xBE44;&#xD574;&#xC5D0;&#xC11C; &#xAE30;&#xB85D; &#xD588;&#xB2E4;. &#xC804;&#xC790; &#xD604;&#xBBF8;&#xACBD;&#xC744; &#xC2A4;&#xCE90;&#xB2DD; &#xD574;&#xC0B0; &#xD558; &#xACE0; &#xC2E4;&#xD5D8;&#xC801; &#xCE58;&#xB8CC;&#xC5D0;&#xC11C; &#xC178; &#xAD11;&#xBB3C;&#xC758; &#xC5D0;&#xCE6D;&#xC744; &#xACF5;&#xAC1C; &#xD588;&#xB2E4;. &#xBCF4;&#xC0C1; &#xAC15;&#xD654;&#xC758; &#xBD80;&#xC7AC;, &#xBC14;&#xB2E4; pH &#xC800;&#xD558;&#xB85C; &#xBC1C;&#xACAC;&#xB41C; &#xC5EC;&#xC131; &#xBE0C;&#xB8E8; &#xB4DC; &#xCC54;&#xBC84; &#xD574;&#xC0B0;&#xC744; &#xB530;&#xB974;&#xAC8C; &#xB420; &#xAC83;&#xC785;&#xB2C8;&#xB2E4;. &#xC178;&#xC744; &#xB974;&#xACE0; holopelagic &#xC874;&#xC7AC;&#xC758; &#xC9C4;&#xD654;&#xC5D0; &#xB300; &#xD55C; &#xC911;&#xC694; &#xD55C; &#xC801;&#xC751; &#xC774;&#xD6C4;, A. nodosa&#xC758; &#xC9C0; &#xC18D;&#xC131; &#xBC14;&#xB2E4; &#xBCC0;&#xD654; &#xC138;&#xACC4;&#xC5D0;&#xC11C; &#xC258; &#xD574;&#xC0B0;&#xC5D0; &#xC758;&#xD574; &#xC190;&#xC0C1; &#xB420; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;.

&#xAE30;&#xD6C4; &#xBCC0;&#xD654; &#xBC14;&#xB2E4; &#xC885;&#xC774; &#xB178;&#xD2F8;&#xB7EC;&#xC2A4; (Argonauta nodosa) &#xC178; &#xCDE8;&#xC57D;&#xC810;: &#xD574;&#xC0B0;&#xC5D0; &#xC758;&#xD574; &#xBA78;&#xC885;&#xC5D0; &#xB300; &#xD55C; &#xC7A0;&#xC7AC;&#xC801;&#xC778;.

Calcificaci&oacute;n de la c&aacute;scara en Argonautas es &uacute;nica. S&oacute;lo las hembras de estos cefal&oacute;podos construyen la c&aacute;scara de papel nautilus, que se utiliza como una c&aacute;mara de cr&iacute;a para el desarrollo de embriones en el Reino pel&aacute;gico. Como uno de los m&aacute;s delgado (225 &mu;m) conocido de conchas de moluscos para adultos y que carece de una carcasa de protecci&oacute;n como periostracum, esta c&aacute;scara puede ser susceptible a disoluci&oacute;n como el oc&eacute;ano se calienta y disminuye en el pH. Vulnerabilidad de la concha a. nodosa fue investigado a trav&eacute;s de la inmersi&oacute;n de fragmentos de c&aacute;scara en experimentos multifactoriales de control (19 &deg; C/pH 8.1 pCO (2) 419; &Omega;(Ca) = 4.23) y condiciones de futuro cercano (24 &deg; C/pH 7.8-7.6 PCO (2) 932-1525; &Omega;(Ca) = 2.72-1.55) durante 14 d&iacute;as. M&aacute;s tratamientos extremos de pH (pH 7.2-7.4 PCO (2) 2454-3882; &Omega;(Ca) = 1.20-0.67) fueron utilizados para determinar los puntos de inflexi&oacute;n en la disoluci&oacute;n de la c&aacute;scara. Difractometr&iacute;a de rayos x no revel&oacute; ning&uacute;n cambio en mineralog&iacute;a entre conchas sin tratar y tratadas. Peso carcasa reducida debido a la disoluci&oacute;n fue evidente en conchas que se incub&oacute; a pH 7,8 (proyectado para 2070) despu&eacute;s de 14 d&iacute;as a temperatura controlada, con mayor disoluci&oacute;n en tratamientos m&aacute;s caliente y m&aacute;s bajo pH. La disoluci&oacute;n mayor se registr&oacute; a 24 &deg; C (proyectado para aguas locales para el a&ntilde;o 2100) en comparaci&oacute;n con el control de temperatura a trav&eacute;s de todos los tratamientos de pH bajo. Microscop&iacute;a electr&oacute;nica de barrido revel&oacute; disoluci&oacute;n y detalles del mineral de la concha en tratamientos experimentales. En la ausencia de mineralizaci&oacute;n compensatoria, la c&aacute;mara de cr&iacute;a hembra descubierta ser&aacute; susceptible a la disoluci&oacute;n a medida que disminuye el pH del oc&eacute;ano. Puesto que la c&aacute;scara era una adaptaci&oacute;n crucial para la evoluci&oacute;n de la existencia de los Argonautas holopelagic, persistencia de a. nodosa puede estar comprometida por la disoluci&oacute;n de la c&aacute;scara en un mundo de oc&eacute;ano-cambio.

Vulnerabilidad de la c&aacute;scara de papel Nautilus (Argonauta nodosa) a un oc&eacute;ano de cambio clim&aacute;tico: potencial de extinci&oacute;n por disoluci&oacute;n.

In response to microbial invasion of dentin odontoblasts secrete an altered calcified matrix termed reactionary dentin (Rd). 3D reconstruction of focused-ion-beam scanning electron microscopy (FIB-SEM) image slices revealed helical tubular structures in Rd that contrasted with regular cylindrical tubules characteristic of dentin from healthy teeth and affected so-called physiological dentin (Pd) lying exterior to Rd. This helical structure in Rd provided effective constriction of tubule lumen diameter that formed a barrier to bacterial advance towards the dental pulp. SEM of resin cast preparations revealed altered extension of odontoblast processes through Rd. The distribution of key mineral elements was studied by combination of 3D reconstruction of focused-ion-beam based X-ray microanalysis (FIB-EDS), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). There was a marked redistribution of calcium and phosphorous in Rd together with an increase of diffusely deposited magnesium compatible with the mineral deposition phase of synthesis of this altered matrix. Changes in tubule structure and mineral content characteristic of Rd are consistent with reduced hardness and lower elastic modulus reported for this matrix. Findings provide insight into the unique structure of Rd synthesised as a primary response to infection.

Structural analysis of reactionary dentin formed in response to polymicrobial invasion.

The identification and quantification of the different ferrite microconstituents in steels has long been a major challenge for metallurgists. Manual point counting from images obtained by optical and scanning electron microscopy (SEM) is commonly used for this purpose. While classification systems exist, the complexity of steel microstructures means that identifying and quantifying these phases is still a great challenge. Moreover, point counting is extremely tedious, time consuming, and subject to operator bias. This paper presents a new automated identification and quantification technique for the characterisation of complex ferrite microstructures by electron backscatter diffraction (EBSD). This technique takes advantage of the fact that different classes of ferrite exhibit preferential grain boundary misorientations, aspect ratios and mean misorientation, all of which can be detected using current EBSD software. These characteristics are set as criteria for identification and linked to grain size to determine the area fractions. The results of this method were evaluated by comparing the new automated technique with point counting results. The technique could easily be applied to a range of other steel microstructures.

An automated method of quantifying ferrite microstructures using electron backscatter diffraction (EBSD) data.

Trace elements diffuse negligible distances through the pristine crystal lattice in minerals: this is a fundamental assumption when using them to decipher geological processes. For example, the reliable use of the mineral zircon (ZrSiO4) as a U-Th-Pb geochronometer and trace element monitor requires minimal radiogenic isotope and trace element mobility. Here, using atom probe tomography, we document the effects of crystal-plastic deformation on atomic-scale elemental distributions in zircon revealing sub-micrometre-scale mechanisms of trace element mobility. Dislocations that move through the lattice accumulate U and other trace elements. Pipe diffusion along dislocation arrays connected to a chemical or structural sink results in continuous removal of selected elements (for example, Pb), even after deformation has ceased. However, in disconnected dislocations, trace elements remain locked. Our findings have important implications for the use of zircon as a geochronometer, and highlight the importance of deformation on trace element redistribution in minerals and engineering materials.

Deformation-induced trace element redistribution in zircon revealed using atom probe tomography.

Diamonds and their inclusions are unique probes into the deep Earth, tracking the deep carbon cycle to >800 km. Understanding the mechanisms of carbon mobilization and freezing is a prerequisite for quantifying the fluxes of carbon in the deep Earth. Here we show direct evidence for the formation of diamond by redox reactions involving FeNi sulfides. Transmission Kikuchi Diffraction identifies an arrested redox reaction from pyrrhotite to magnetite included in diamond. The magnetite corona shows coherent epitaxy with relict pyrrhotite and diamond, indicating that diamond nucleated on magnetite. Furthermore, structures inherited from h-Fe3O4 define a phase transformation at depths of 320-330 km, the base of the Kaapvaal lithosphere. The oxidation of pyrrhotite to magnetite is an important trigger of diamond precipitation in the upper mantle, explaining the presence of these phases in diamonds.

Redox-freezing and nucleation of diamond via magnetite formation in the Earth's mantle.

Fungal growth in indoor environments is associated with many negative health effects. Many studies focus on brown- and white-rot fungi and their effect on wood, but there is none that reveals the influence of soft-rot fungi, such as Stachybotrys spp. and Chaetomium spp., on the structure of building materials such as plywood and gypsum wallboard. This study focuses on using micro-computed tomography (microCT) to investigate changes of the structure of plywood and gypsum wallboard during fungal degradation by S. chartarum and C. globosum. Changes in the materials as a result of dampness and fungal growth were determined by measuring porosity and pore shape via microCT. The results show that the composition of the building material influenced the level of penetration by fungi as shown by scanning electron microscopy (SEM). Plywood appeared to be the most affected, with the penetration of moisture and fungi throughout the whole thickness of the sample. Conversely, fungi grew only on the top cardboard in the gypsum wallboard and they did not have significant influence on the gypsum wallboard structure. The majority of the observed changes in gypsum wallboard occurred due to moisture. This paper suggests that the mycelium distribution within building materials and the structural changes, caused by dampness and fungal growth, depend on the type of the material.

Visualization of the structural changes in plywood and gypsum board during the growth of Chaetomium globosum and Stachybotrys chartarum.

The application of atom probe tomography to the study of minerals is a rapidly growing area. Picosecond-pulsed, ultraviolet laser (UV-355 nm) assisted atom probe tomography has been used to analyze trace element mobility within dislocations and low-angle boundaries in plastically deformed specimens of the nonconductive mineral zircon (ZrSiO4), a key material to date the earth's geological events. Here we discuss important experimental aspects inherent in the atom probe tomography investigation of this important mineral, providing insights into the challenges in atom probe tomography characterization of minerals as a whole. We studied the influence of atom probe tomography analysis parameters on features of the mass spectra, such as the thermal tail, as well as the overall data quality. Three zircon samples with different uranium and lead content were analyzed, and particular attention was paid to ion identification in the mass spectra and detection limits of the key trace elements, lead and uranium. We also discuss the correlative use of electron backscattered diffraction in a scanning electron microscope to map the deformation in the zircon grains, and the combined use of transmission Kikuchi diffraction and focused ion beam sample preparation to assist preparation of the final atom probe tip.

Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study.

Scanning electron microscopy transmission Kikuchi diffraction is able to identify twins in nanocrystalline material, regardless of their crystallographic orientation. In this study, it was employed to characterize deformation twins in Cu/10 wt % Zn processed by high-pressure torsion. It was found that in 83% of grains containing twins, at least one twin intersects with a triple junction. This suggests that triple junctions could have promoted the nucleation of deformation twins. It should be cautioned that this technique might be unable to detect extremely small nanoscale twins thinner than its step size.

Effect of triple junctions on deformation twinning in a nanostructured Cu-Zn alloy: A statistical study using transmission Kikuchi diffraction.

Correlative microscopy approaches offer synergistic solutions to many research problems. One such combination, that has been studied in limited detail, is the use of atom probe tomography (APT) and transmission Kikuchi diffraction (TKD) on the same tip specimen. By combining these two powerful microscopy techniques, the microstructure of important engineering alloys can be studied in greater detail. For the first time, the accuracy of crystallographic measurements made using APT will be independently verified using TKD. Experimental data from two atom probe tips, one a nanocrystalline Al-0.5Ag alloy specimen collected on a straight flight-path atom probe and the other a high purity Mo specimen collected on a reflectron-fitted instrument, will be compared. We find that the average minimum misorientation angle, calculated from calibrated atom probe reconstructions with two different pole combinations, deviate 0.7° and 1.4°, respectively, from the TKD results. The type of atom probe and experimental conditions appear to have some impact on this accuracy and the reconstruction and measurement procedures are likely to contribute further to degradation in angular resolution. The challenges and implications of this correlative approach will also be discussed.

Patrick Trimby

Australian Centre for Microscopy and Microanalysis

The University of Sydney

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

Patrick Trimby

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Australian Centre for Microscopy and Microanalysis

The University of Sydney

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

Australian Centre for Microscopy and Microanalysis