Cenozoic uplift of the Tibetan Plateau:Evidence from the tectonic-sedimentary evolution of the western Qaidam Basin

Geologists agree that the collision of the Indian and Asian plates caused uplift of the Tibet Plateau. However, controversy still exists regarding the modes and mechanisms of the Tibetan Plateau uplift. Geology has recorded this uplift well in the Qaidam Basin. This paper analyzes the tectonic and sedimentary evolution of the western Qaidam Basin using sub-surface seismic and drill data. The Cenozoic intensity and history of deformation in the Qaidam Basin have been reconstructed based on the tectonic developments, faults growth index, sedimentary facies variations, and the migration of the depositional depressions. The changes in the sedimentary facies show that lakes in the western Qaidam Basin had gone from inflow to still water deposition to withdrawal. Tectonic movements controlled deposition in various depressions, and the depressions gradually shifted southeastward. In addition, the morphology of the surface structures in the western Qaidam Basin shows that the Cenozoic tectonic movements controlled the evolution of the Basin and divided it into （a） the southern fault terrace zone, （b） a central Yingxiongling orogenic belt, and （c） the northern fold-thrust belt; divided by the XI fault （Youshi fault） and Youbei fault, respectively. The field data indicate that the western Qaidam Basin formed in a Cenozoic compressive tectonic environment caused by the India--Asia plate collision. Further, the Basin experienced two phases of intensive tectonic deformation. The first phase occurred during the Middle Eocene--Early Miocene （Xia Ganchaigou Fm. and Shang Ganchaigou Fro., 43.8- 22 Ma）, and peaked in the Early Oligocene （Upper Xia Ganchaigou Fro., 31.5 Ma）. The second phase occurred between the Middle Miocene and the Present （Shang Youshashan Fro. and Qigequan Fro., 14.9-0 Ma）, and was stronger than the first phase. The tectonic--sedimentary evolution and the orienta- tion of surface structures in the western Qaidam Basin resulted from the Tibetan Plateau uplift, and recorded the periodic northward growth of the Plateau. Recognizing this early tectonic--sedimentary evolution supports the previous conclusion that northern Tibet responded to the collision between India and Asia shortly after its initiation. However, the current results reveal that northern Tibet also experi- enced another phase of uplift during the late Neogene. The effects of these two stages of tectonic activity combined to produce the current Tibetan Plateau.

Investigation on Virtual State Contribution to Gauge Invariant Cross Section of e⁺e^-→J/ψ+η_cin Bethe-Salpeter Framework

It is shown that the virtual states and relative momentum of the constituents of the bound states are very important for the cross section of the process e+e-→J/ψ+ηc with the help of the Bethe-Salpeter wave function description of the bound states. The gauge invariance of the cross section is demonstrated. The numerical results can explain the experimental data.

Umbilical cord artery-derived perivascular stem cells for treatment of ovarian failure through CD146 signaling

Dear Editor,Chemotherapy-induced ovarian failure significantly diminishes ovarian blood flow,ovarian size,and follicular development.Angiogenesis plays a vital role in repairing ovarian damage.1 Perivascular stem cells(PSCs),known as mural cells covering the vasculature,are essential for blood vessel formation and postulated as progenitors of mesenchymal stem cells(MSCs).2,3 We previously established umbilical cord artery-derived PSCs(UCA-PSCs)and Wharton’s jelly-derived MSCs(WJ-MSCs)and UCAPSCs display optimal angiogenic capacity in vitro.4 Therefore,we explored the angiogenesis and pro-angiogenesis mechanisms of UCA-PSCs and provided them as an efficient treatment strategy for ovarian failure.

A Model for Agglomeration in Bio-fuel Fired Fluidized Bed

A mathematical model has been developed to describe the agglomeration process in bio-fuel fired fluidized bed combustor.Based on the balance mechanism of the adhesive force caused by liquid bonding between two particles and the breaking force induced by bubbles in the fluidized bed,the model considers modified Urbain model and chemical equilibrium calculations using FactSage modeling.This model prediction accounts for the evolvement of the adhesive and breaking forces,and clearly demonstrates that the different composition of ash,the increasing liquid phase matter and the fluidization velocity cause defluidization in fluidized bed.In this model,it is the first time to hypothesize that the bonding stress between two particles is proportional to mass fraction of liquid phase and inversely proportional to the diameter of particles and viscosity of liquid phase.The defluidization time calculated by this model shows good agreement with that from the experimental data.