An improved understanding of the elevation history of the Tibetan Plateau is crucial in discriminating among the various tectonic models for the evolution of the India-Asia continental collision. We reconstruct the paleoelevation history for three Cenozoic sedimentary basins from SE Tibet and Yunnan, China, to provide more constraints on the tectonic processes for raising the SE margin of the Tibetan Plateau. The results presented here, together with those of previous studies, indicate that (1) the plateau margin of NW Yunnan was near its elevation (~2.6 km) by the latest middle Eocene (~40 Ma); (2) the plateau margin of SE Yunnan reached its current elevation (~1.6 km) by the middle Miocene (~13 Ma). Interpretation of the tectonic processes responsible for this inferred surface uplift of the region is made in the context of well-documented surface geology. We conclude that high landscape (~2.6 km elevation) in NW Yunnan may represent the remnants of the Eocene Tibetan plateau that originally formed in the northeastern Qiangtang Block by crustal thickening associated with the India-Asia continental collision. The near-modern elevation of SE Yunnan since ~13 Ma probably reflects the initiation of lower crustal flow in this area at least at that time. Collectively, these paleoaltimetric data disagree with previously proposed middle Miocene to Pliocene crustal flow acting as a sole tectonic process for raising the SE margin of the plateau, but support a protracted surface uplift, that most likely involved crustal thickening during the Eocene, southeastward extrusion of a portion of Eocene

The stable isotope compositions of carbonate and organic samples from the Oiyug basin in southern Tibet allows for model calculations of the Oligocene to Pliocene paleoelevation of the south central Tibetan Plateau. We measured the oxygen isotope composition of pedogenic and lacustrine calcite, dolomite, and siderite, and the hydrogen isotope composition of n-alkanes from plant waxes to reconstruct the ␦ 18 O and ␦D values of Oiyug basin paleometeoric water. Calculated water isotope values from Oiyug basin carbonate and organic samples, respectively, are in close agreement, suggesting the preservation of an unaltered paleometeoric water isotopic signal in these archives. Late Oligocene-middle Miocene paleoelevation estimates from groundwater/ pedogenic calcite and lacustrine dolomite indicate basin elevations of 4.1 km ؉1.2/ ؊1.6 km. Plant-wax n-alkanes ␦D and lacustrine-siderite ␦ 18 O compositions of middle Miocene (ϳ15 Ma) samples indicate paleoelevations of 5.1 km ؉1.3/؊1.9 km. This estimated elevation is similar to the 5.4 km paleoelevation estimate based on fossilfloral physiognomy from the same stratigraphic interval. Calculated late MiocenePliocene paleoelevation estimates derived from the ␦ 18 O composition of lacustrine marls and carbonate/siderite concretions, as well as the ␦D from plant wax n-alkanes indicate a mean elevation of 5.5 km ؉1.4/؊2.0 km at ϳ5 Ma. Although calculated mean paleoelevations for the Oiyug basin all fall within the errors associated with the model calculations, the close agreement of the different paleoelevation proxies provides an additional degree of confidence in the fidelity of the calculated paleoelevations. Calculated paleoelevations indicate a possible increase in Oiyug basin elevations of ϳ1.4 km between the early and late Miocene. Given the modern Oiyug basin elevation of ϳ4.3 km, study results allow for a possible >1 km decrease in elevation since the early Pliocene. These findings, in conjunction with other Tibetan paleoaltimetry studies, are consistent with tectonic models supporting high elevations of the Tibetan Plateau since the initiation of India-Asia collision during the Eocene, and subsequent late Cenozoic extensional collapse.

Single-crystalline intrinsic and N-doped p-type ZnTe nanoribbons (NRs) were synthesized via the thermal evaporation method in argon-mixed hydrogen and nitrogen-mixed ammonia, respectively. Both intrinsic and doped ZnTe nanoribbons had zinc blende structure and uniform geometry. X-ray diffraction peaks of N-doped ZnTe nanoribbons had an obvious shift toward higher angle direction as compared with intrinsic ZnTe. X-ray photoelectron spectroscopy detection confirmed that the dopant content of nitrogen in ZnTe nanoribbons was close to 1%. Field-effect transistors based on both intrinsic and N-doped ZnTe nanoribbons were constructed. Electrical measurements demonstrated that N-doping led to a substantial enhancement in p-type conductivity of ZnTe nanoribbons with a high hole mobility of 1.2 cm−2 V−1 S−1 and a low resistivity of 0.14 Ω cm in contrast to the 6.2 × 10−3 cm−2 V−1 S−1 and 45.1 Ω cm for intrinsic nanoribbons. Moreover, the defect reaction mechanism was proposed to explain the p-type behaviors of both the intrinsic and the N-doped ZnTe nanoribbons.The ZnTe nanoribbons with enhanced p-type conductivity may have important potential applications in nanoelectronic and optoelectronic devices.

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The elevation history of the Tibetan Plateau promises insight into the mechanisms and dynamics that develop and sustain high topography over tens of millions of years. We present the first nearly continuous Cenozoic elevation history from two sedimentary basins on the southern Tibetan Plateau within the latest Cretaceous to Eocene Gangdese arc. Oxygen isotope and Δ47 clumped isotope compositions of non-marine carbonates allow us to constrain carbonate formation temperature and reconstruct the paleo-precipitation record of the Eocene to Pliocene Manuscript Stable isotope paleoaltimetry in the India-Asia collision zone Numerous investigations have reconstructed the elevation history of the Himalayas and Tibetan Plateau using the oxygen isotopic composition of non-marine carbonates (Garzione et

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Silicon based optoelectronic integration is restricted by its poor optoelectronic properties arising from the indirect band structure. Here, by combining silicon with another promising optoelectronic material, the CdS nanoribbon (NR), devices with heterojunction structure were constructed. The CdS NRs were also doped with gallium to improve their n-type conductivity. A host of nano-optoelectronic devices, including light emitting diodes, photovoltaic devices, and photodetectors, were successfully constructed on the basis of the CdS:Ga NR/Si heterojunctions. They all exhibited excellent device performances as regards high stability, high efficiency, and fast response speed. It is expected that the CdS NR/Si heterojunctions will have great potential for future applications of Si based optoelectronic integration.

High-performance field-effect transistors (FETs) based on single phosphorus-doped n-type CdS nanoribbon with high-κ HfO2 dielectric and top-gate geometry were constructed. In contrast to the nano-FETs that were fabricated on SiO2/Si substrate with back-gate device configuration, the top-gate FETs exhibit a substantial improvement in performances, i.e., work voltage was reduced to a small value of within ±5 V, the subthreshold swing was reduced to 200 mV/dec and the Ion/Ioff ratio was increased by about six orders of magnitude. The top-gate CdS:P nano-FET shows high sensitivity upon light irradiation, revealing that the top-gate FETs are promising candidates for nanoelectronic and optoelectronic applications.