The alteration of platinum group minerals (PGM) of eluval, proximal, and distal placers associated with the Ural-Alaskan type clinopyroxenite-dunite massifs were studied. The Isovsko-Turinskaya placer system is unique regarding its size, and was chosen as research object as it is PGM-bearing for more than 70 km from its lode source, the Ural-Alaskan type Svetloborsky massif, Middle Urals. Lode chromite-platinum ore zones located in the Southern part of the dunite “core” of the Svetloborsky massif are considered as the PGM lode source. For the studies, PGM concentrates were prepared from the heavy concentrates which were sampled at different distances from the lode source. Eluvial placers are situated directly above the ore zones, and the PGM transport distance does not exceed 10 m. Travyanistyi proximal placer is considered as an example of alluvial ravine placer with the PGM transport distance from 0.5 to 2.5 km. The Glubokinskoe distal placer located in the vicinity of the Is settlement are chosen as the object with the longest PGM transport distance (30–35 km from the lode source). Pt-Fe alloys, and in particular, isoferroplatinum prevail in the lode ores and placers with different PGM transport distance. In some cases, isoferroplatinum is substituted by tetraferroplatinum and tulameenite in the grain marginal parts. Os-Ir-(Ru) alloys, erlichmanite, laurite, kashinite, bowieite, and Ir-Rh thiospinels are found as inclusions in Pt-Fe minerals. As a result of the study, it was found that the greatest contribution to the formation of the placer objects is made by the erosion of chromite-platinum mineralized zones in dunites. At a distance of more than 10 km, the degree of PGM mechanical attrition becomes significant, and the morphological features, characteristic of lode platinum, are practically not preserved. One of the signs of the significant PGM transport distance in the placers is the absence of rims composed of the tetraferroplatinum group minerals around primary Pt-Fez alloys. The sie of the nuggets decreases with the increasing transport distance. The composition of isoferroplatinum from the placers and lode chromite-platinum ore zones are geochemically similar.

In this study, sulphate efflorescent minerals covering the surface of the Donnoe and Dachnoe fields of the Mutnovsky volcano are described. The minerals were precipitated on the argillic facies as the result of water–rock interaction and fumarole emission. A chemical composition of Ca, Ba, (NH₄)⁺, Na-Fe³⁺, (NH₄)⁺-Al, (NH₄)⁺-Fe³⁺, Na-Al, K-Al, and K-Fe³⁺ sulphates was reported. Elements such as Sr, Mg, Co, Ni, Ti and P were found as isomorphic impurities. Ammonia species were concentrated around fumaroles. The mineral assemblage described herein is unique in relation to other geological settings and reflects the process of low-temperature mineral formation associated with volcanism. The thermal water contains cations such as H, Na, K, NH₄, Ca, Mg, Fe²⁺, Fe³⁺, and Al in different proportions with pH ranging from 2.4 to 6.5 and the dominance of acidic waters. The gas condensate bears such cations as (NH₄)⁺, Ca, and Mg and has a pH of ~5. Thus, the rest of the main cations are derived from the leaching of the host rocks. Among the identified phases, the alunite-supergroup minerals are more prone to isomorphism. The Ti, Co, and Ni impurities mark the unique geochemistry of thermal water at the Mutnovsky volcano. We postulate that the chemical composition of alunite-supergroup minerals reflects the types of hydrothermal occurrences and contains important information on the geochemistry of the hydrothermal process.

The Itchayvayamsky Ural-Alaskan-type massif is located in the northernmost part of the Koryak-Kamchatka Platinum Belt (Russia) and is surrounded by two rivers (Kamenistaya and Itchayvayam) that both contain specific PGM (platinum group minerals) assemblages. The PGMs of the Kamenistaya River are represented by isoferroplatinum with minor admixtures of Pd and Cu (up to 1.97 and 1.37 wt.%, respectively) and numerous inclusions of other PGMs such as laurite, erlichmanite, and boweite. The Itchayvayam River assemblage is different, as it contains minor amounts of isoferroplatinum and other minerals identical to those of the Kamenistaya River, as well as abundant native platinum rich in Cu and Pd (up to 4.30 and 2.34 wt.%, respectively) and rimmed by secondary cooperite and malanite. Grains of gold intergrown with unnamed Au-Hg-Pd minerals, cooperite, vysotskite, and malanite were also found exclusively in the Itchayvayam River. Three mineral assemblages are spatially related to the Itchayvayam massif and are distinguished by: (1) isoferroplatinum, (2) native platinum, and (3) gold-mercury-palladium. Isoferroplatinum assemblages are typical for placers derived from Ural-Alaskan-type massifs and lodes (e.g., the Galmoenan massif in the Koryak Highlands). Simultaneously, the native platinum assemblages are rare and have been described as lodes in clinopyroxenites, and in sub-economic placers derived from clinopyroxenite-dominant massifs. Therefore, it is assumed that the origin of the first assemblage is from lodes in dunite and the second is from lodes in clinopyroxenite. In addition, gold-mercury-palladium assemblages apparently originated from mineralized zones, analogous to those intruding gabbro and monzonite at the nearby Barany massif, which contains native gold and Pd-sulfides. Our study of the structure and compositions of Pt-Fe minerals showed that in the structure of isoferroplatinum Cu and Ni substitute for Fe, whereas in native platinum they substitute for both Pt and Fe.

Two $π$-conjugated acceptor-donor-acceptor-donor-acceptor-type (A-D-A-D-A) oligothiophenes, $TT-(2T-DCV-Hex)2$ and $BT-(2T-DCV-Hex)2$ were designed and synthesized with thienothiadiazole (TT) or benzothiadiazole (BT) as the core and dicyanovinyl (DCV) as the terminal acceptor groups for comprehensively investigating and understanding structure–property relationships. The resulting oligomers were first characterized by thermal analysis, UV-Vis spectroscopy, and cyclic voltammetry. By simply changing the BT to TT core in these two oligothiophenes, the highest occupied molecular orbital levels were varied from $−5.55eV$ for $BT-(2T-DCV-Hex)2$ to $−5.11eV$ for $TT-(2T-DCV-Hex)2$, and the optical band gaps were varied from 1.72 eV for $BT-(2T-DCV-Hex)2$ to 1.25 eV for $TT-(2T-DCV-Hex)2$, ascribed to the stronger electron accepting character of the TT core. However, the power conversion efficiency of bulk heterojunction organic solar cells (OSCs) with $TT-(2T-DCV-Hex)2$ as donor and [6,6]-phenyl $C70$-butyric acid methyl ester ($PC71BM$) as acceptor was measured to be 0.04% only, which is much lower than that of $BT-(2T-DCV-Hex)2:PC71BM$ (1.54%). Compared to the $TT-(2T-DCV-Hex)2$ system, the $BT-(2T-DCV-Hex)2$ based device shows smoother film surface morphology, and superior charge generation and charge carrier mobilities. Therefore, the results clearly demonstrate that in addition to modifying the alkyl side chains and $π$-bridge lengths, the design of new small molecules for high-performance OSCs should also aim to choose suitable acceptor units.