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Zhokhov Island in the Siberian High Arctic has yielded evidence for some of the most remote prehistoric human occupation in the world, as well as the oldest-known dog-sled technology. Obsidian [...]

Various types of early Palaeogene calderas indicating transtensional (strike-slip fault-related extensional structure and extensional strike-slip duplex) and transpressional (contractional) structures have been identified in southern Sikhote-Alin (northeastern Asia). These volcanic structures formed due to the NNW-oriented (345–355°) stress during left-lateral displacements within a zone of dynamic interaction between the main tectonic units of the territory: the Central Sikhote-Alin and Vostochny Faults. These faults form a large-scale fault zone, where strike-slip displacements and magmatic activity propagated from boundary faults to the central area of the fault zone. The analysis of regional faulting morphology and kinematics within this fault zone and its vicinity shows that the NNE-trending strike-slip faults bend into NE-trending thrust zones on its southern and northern flanks. These changes reveal a regional S-shaped structure that we named the 'sinistral kink band of southern Sikhote-Alin'. The activation of the subparallel NNE-trending sinistral faults in the central part of the kink band accounts for the increased permeability of the basement and terrigenous strata. The early Palaeogene magmatic activity should be regarded as a marker of left-lateral displacements from at least ~61–55 Ma due to oblique interactions between continental and oceanic plates along the northeastern Asian margin. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a theoretical analysis of the class‐E/F3 power amplifier based on the variation of the grading coefficient m1 and its vital role in MOSFET selectivity to operate safely under given design specifications is presented while the nonlinearity of the drain‐to‐source capacitance is considered. Moreover, the importance of Vbi and Cjo in designing the class‐E/F3 amplifier is investigated. To clarify how the grading coefficient m1 and the other mentioned parameters can directly influence the power amplifier performance and also its elements, these MOSFET parameters are considered as the independent variables of the calculated equations and consequently define the horizontal axis of the obtained plots. Accordingly, as the grading coefficient increases, the maximum switch voltage increases and values of the output power and output power capability decline. Moreover, to prove the reliability of the carried‐out analysis in selecting proper MOSFETs, the performances of three amplifier samples utilizing IRF510, IRFZ24N, and 2SK2504 MOSFETs with different grading coefficient m1 and almost similar Vbi and Cjo are studied. Then, by comparing the results of amplifiers with three MOSFETs, IRF510, IRF530, and IRF540, with similar grading coefficient and different values of Vbi and Cjo, the significance of considering the values of Vbi and Cjo is investigated. Eventually, three amplifiers with 2SK2504, IRF510, and IRF530 MOSFETs have been simulated, implemented, and tested and measurement results agreed well with the theoretical and simulation results. [ABSTRACT FROM AUTHOR]

In this paper, a Doherty power amplifier based on an inverse Class‐E amplifier with a series output filter are presented. The proposed inverse Class‐E amplifier has been designed and simulated using lumped elements and transmission lines (TL), respectively. The high‐performance simulation results of TL inverse Class‐E PA with an output power of 46.2 dBm, peak drain efficiency of 71%, and a power gain of 27 dB at an input power 18 dBm have been obtained. Finally, the Doherty power amplifier (DPA) based on the inverse Class‐E power amplifier with some asymmetry in two paths has been designed and implemented. Implementation of both carrier and peaking amplifiers with an inverse Class‐E load network can provide an increase in the efficiency and improvement of harmonic suppression levels. Maximum drain efficiencies of 69.3% and 54% at maximum output power level (50 dBm) and 7‐dB back‐off power level (43 dBm) have been measured, respectively. [ABSTRACT FROM AUTHOR]

Obsidian provenance studies in the southern Kuriles (Kunashir and Iturup islands), part of the insular Russian Far East, are reviewed and summarized for the first time. The sites analyzed belong to the Jomon (ca. 7300–2500 BP), Epi-Jomon (ca. 2500–1400 BP), and Okhotsk (ca. 1400–800 BP) cultural complexes, with particular attention given to the well-studied Yankito 2 site. The main sources of high-quality volcanic glass for the southern Kuriles were on the neighboring Hokkaido Island—Oketo and Shirataki (ca. 140–390 km away). The presence of obsidian at an Epi-Jomon site on southern Kunashir Island originating from remote sources on the Kamchatka Peninsula ca. 1290–1440 km away is an important contribution to understanding the prehistoric contacts and population dispersals that occurred within insular Northeast Asia. This is also supported by paleoanthropological and DNA data from Epi-Jomon human remains on Iturup, showing similarities with native Kamchatkan populations. The use of boats in the southern Kuriles is evident from the beginning of colonization, ca. 7300–7100 BP given that islands were not connected after the Early Holocene due to sea level rise. It is clear that seafaring was an important part of human activities throughout the entire island chain since the Epi-Jomon, ca. 2500 BP. Because the Kurile Islands were one of the most probable migration routes between Northeast Asia (i.e., Japan) and Northeastern Siberia and North America, study of the human colonization of the Kuriles has wider implication for the northeastern part of Eurasia as a gateway to the Americas. [ABSTRACT FROM AUTHOR]