mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Large scale and controllable preparation of W_2C nanorods or WC nanodots with peroxidase-like catalytic activity

W2C nanorods or WC nanodots are prepared via an easy, shape-controllable and large-scale preparation technique. Results reveal that each of theW2C nanorods and WC nanodots has a peroxidase-like activity. Besides, the peroxidase-like activity of W_2C is the first time to be demonstrated. The catalytic efficiency of W_2C nanorods is much higher than that of WC nanodots and chemical condition range of W_2C can be wider than that of WC, which indicates that W_2C is likely to be used as artificial mimetic peroxidase or in-situ amplified colorimetric immunoassay.
A simulation study on p-doping level of polymer host material in P3HT:PCBM bulk heterojunction solar cells

In this study, we investigate the influence of doping on the charge transfer and device characteristics parameters in the bulk heterojunction solar cells based on poly(3-hexylthiophene) (P3HT) and a methanofullerene derivative (PCBM). Organic semiconductors are also known to be not pure and they have defects and impurities, some of them are being charged and act as p-type or n-type dopants. Calculations of the solar cell characteristics parameters versus the p-doping level have been done at three different n-dopings (N_d) that consist of 5×10~(17) cm~(-3), 10~(18) cm~(-3), and 5×10~(18) cm~(-3). We perform the analysis of the doping concentration through the drift-diffusion model, and calculate the current and voltage doping dependency. We find that at three different n-dopant levels, optimum p-type doping is about N_p = 6×10~(18) cm~(-3). Simulation results have shown that by increasing doping level, Voc monotonically increases by doping. Cell efficiency reaches its maximum at somewhat higher doping as FF has its peak at N_p = 3×10~(18) cm~(-3). Moreover, this paper demonstrates that the optimum value for the p-doping is about N_p = 6×10~(18) cm~(-3) and optimum value for n-dopant is N_d = 10~(18) cm~(-3), respectively. The simulated results confirm that doping considerably affects the performance of organic solar cells.
Dynamics of vortex–antivortex pair in a superconducting thin strip with narrow slits

In the framework of phenomenological time-dependent Ginzburg–Landau (TDGL) formalism, the dynamical properties of vortex–antivortex (V-Av) pair in a superconductor film with a narrow slit was studied. The slit position and length can have a great impact not only on the vortex dynamical behavior but also the current–voltage (I–V) characteristics of the sample. Kinematic vortex lines can be predominated by the location of the slit. In the range of relatively low applied currents for a constant weak magnetic field, kinematic vortex line appears at right or left side of the slit by turns periodically. We found such single-side kinematic vortex line cannot lead to a jump in the I–V curve. At higher applied currents the phase-slip lines can be observed at left and right sides of the slit simultaneously. The competition between the vortex created at the lateral edge of the sample and the V-Av pair in the slit will result in three distinctly different scenarios of vortex dynamics depending on slit length: the lateral vortex penetrates the sample to annihilate the antivortex in the slit; the V-Av pair in the slit are driven off and expelled laterally; both the lateral vortex and the slit antivortex are depinned and driven together to annihilation in the halfway.
Interface states study of intrinsic amorphous silicon for crystalline silicon surface passivation in HIT solar cell

Intrinsic hydrogenated amorphous silicon (a-Si:H) film is deposited on n-type crystalline silicon (c-Si) wafer by hotwire chemical vapor deposition (HWCVD) to analyze the amorphous/crystalline heterointerface passivation properties. The minority carrier lifetime of symmetric heterostructure is measured by using Sinton Consulting WCT-120 lifetime tester system, and a simple method of determining the interface state density (D_(it)) from lifetime measurement is proposed. The interface state density (D_(it)) measurement is also performed by using deep-level transient spectroscopy (DLTS) to prove the validity of the simple method. The microstructures and hydrogen bonding configurations of a-Si:H films with different hydrogen dilutions are investigated by using spectroscopic ellipsometry (SE) and Fourier transform infrared spectroscopy (FTIR) respectively. Lower values of interface state density (D_(it)) are obtained by using a-Si:H film with more uniform, compact microstructures and fewer bulk defects on crystalline silicon deposited by HWCVD.
The origin of spin current in YIG/nonmagnetic metal multilayers at ferromagnetic resonance

Spin pumping in yttrium-iron-garnet (YIG)/nonmagnetic-metal (NM) layer systems under ferromagnetic resonance (FMR) conditions is a popular method of generating spin current in the NM layer. A good understanding of the spin current source is essential in extracting spin Hall angle of the NM and in potential spintronics applications. It is widely believed that spin current is pumped from precessing YIG magnetization into NM layer. Here, by combining microwave absorption and DC-voltage measurements on thin YIG/Pt and YIG/NM_1/NM_2 (NM_1 =Cu or Al, NM_2 =Pt or Ta), we unambiguously showed that spin current in NM, instead of from the precessing YIG magnetization, came from the magnetized NM surface (in contact with thin YIG), either due to the magnetic proximity effect (MPE) or from the inevitable diffused Fe ions from YIG to NM. This conclusion is reached through analyzing the FMR microwave absorption peaks with the DC-voltage peak from the inverse spin Hall effect (ISHE). The voltage signal is attributed to the magnetized NM surface, hardly observed in the conventional FMR experiments, and was greatly amplified when the electrical detection circuit was switched on.
Influence of high pulsed magnetic field on tensile properties of TC4 alloy

The tensile tests of TC4 alloy are carried on electronic universal testing machine in the synchronous presence of high pulsed magnetic field (HPMF) parallel to the axial direction. The effects of magnetic induction intensity (B = 0, 1 T, 3 T, and 5 T) on elongation (d) of TC4 alloy are investigated. At 3 T, the elongation arrives at a maximum value of 12.41%, which is enhanced by 23.98% in comparison with that of initial sample. The elongation curve shows that 3 T is a critical point. With B increasing, the volume fraction of α phase is enhanced from 49.7% to 55.9%, which demonstrates that the HPMF can induce the phase transformation from β phase to α phase. Furthermore, the magnetic field not only promotes the orientation preference of crystal plane along the slipping direction, but also has the effect on increasing the dislocation density. The dislocation density increases with the enhancement of magnetic induction intensity and the 3-T parameter is ascertained as a turning point from increase to decrease tendency. When B is larger than 3 T, the dislocation density decreases with the enhancement of B. The influence of magnetic field is analyzed on the basis of magneto-plasticity effect. The high magnetic field will enhance the dislocation strain energy and promote the state conversion of radical pair generated between the dislocation and obstacles from singlet into triplet state, in which is analyzed the phenomenon that the dislocation density is at an utmost with B = 3 T. Finally, the inevitability of optimized 3-T parameter is further discussed on a quantum scale.
Laser phase effect on asymmetric harmonic distribution in H_2~+

The laser phase effect on the spatial distribution of the molecular high-order harmonic generation (MHHG) spectrum from H_2~+  is theoretically investigated through solving the Non-Bohn–Oppenheimer (NBO) time-dependent Schrodinger equation (TDSE). The results are shown as follows. (i) The generated harmonics from the two nuclei each present an asymmetric distribution. Particularly, when the laser phases are chosen from 0.0π to 0.6π and from 1.7π to 2.0π, the contribution from the negative-H plays a main role in harmonic generation. When the laser phases are chosen from 0.7π to 1.6π, the contribution from the positive-H to the harmonic generation is remarkably enhanced and becomes greater than that from the negative-H. The electron localization, the time-frequency analyses of the harmonic spectrum and the time-dependent wave function are shown to explain the asymmetric harmonic distribution in H_2~+  , which provides us with a method to control the electron motion in molecules. (ii) As the pulse duration increases, the asymmetric distributions of the MHHG in two H nuclei decrease. (iii) Isotope investigation shows that the asymmetric harmonic distribution can be reduced by introducing the heavy nucleus (i.e., D_2~+).
Compressing ultrafast electron pulse by radio frequency cavity

An ultrafast electron diffraction technique with both high temporal and spatial resolution has been shown to be a powerful tool to observe the material transient structural change on an atomic scale. The space charge forces in a multi-electron bunch will greatly broaden the electron pulse width, and therefore limit the temporal resolution of the high brightness electron pulse. Here in this work, we design an ultrafast electron diffraction system, and utilize a radio frequency cavity to realize the ultrafast electron pulse compression. We experimentally demonstrate that the stretched electron pulse width of 14.98 ps with an electron energy of 40 keV and the electron number of 1.0×10~5 can be maximally compressed to about 0.61 ps for single-pulse measurement and 2.48 ps for multi-pulse measurement by using a 3.2-GHz radiofrequency cavity. We also theoretically and experimentally analyze the parameters influencing the electron pulse compression efficiency for single- and multi-pulse measurements by considering radiofrequency field time jitter, electron pulse time jitter and their relative time jitter. We suggest that increasing the electron energy or shortening the distance between the compression cavity and the streak cavity can further improve the electron pulse compression efficiency. These experimental and theoretical results are very helpful for designing the ultrafast electron diffraction experiment equipment and compressing the ultrafast electron pulse width in a future study.
The interaction between stratospheric monthly mean regional winds and sporadic-E

In the present study, a statistical investigation is carried out to explore whether there is a relationship between the critical frequency (foEs) of the sporadic-E layer that is occasionally seen on the E region of the ionosphere and the quasibiennial oscillation (QBO) that flows in the east–west direction in the equatorial stratosphere. Multiple regression model as a statistical tool was used to determine the relationship between variables. In this model, the stationarity of the variables (foEs and QBO) was firstly analyzed for each station (Cocos Island, Gibilmanna, Niue Island, and Tahiti). Then, a cointegration test was made to determine the existence of a long-term relationship between QBO and foEs. After verifying the presence of a long-term relationship between the variables, the magnitude of the relationship between variables was further determined using the multiple regression model. As a result, it is concluded that the variations in foEs were explainable with QBO measured at 10 hPa altitude at the rate of 69%, 94%, 79%, and 58% for Cocos Island, Gibilmanna, Niue Island, and Tahiti stations, respectively. It is observed that the variations in foEs were explainable with QBO measured at 70 hPa altitude at the rate of 66%, 69%, 53%, and 47% for Cocos Island, Gibilmanna, Niue Island, and Tahiti stations, respectively.
Superjunction nanoscale partially narrow mesa IGBT towards superior performance

We present a detailed study of a superjunction (SJ) nanoscale partially narrow mesa (PNM) insulated gate bipolar transistor (IGBT) structure. This structure is created by combining the nanoscale PNM structure and the SJ structure together. It demonstrates an ultra-low saturation voltage (V_(ce(sat))) and low turn-off loss (E_(off)) while maintaining other device parameters. Compared with the conventional 1.2 kV trench IGBT, our simulation result shows that the V_(ce(sat)) of this structure decreases to 0.94 V, which is close to the theoretical limit of 1.2 kV IGBT. Meanwhile, the fall time decreases from 109.7 ns to 12 ns and the E_(off) is down to only 37% of that of the conventional structure. The superior tradeoff characteristic between V_(ce(sat)) and E_(off) is presented owing to the nanometer level mesa width and SJ structure. Moreover, the short circuit degeneration phenomenon in the very narrow mesa structure due to the collector-induced barriers lowering (CIBL) effect is not observed in this structure. Thus, enough short circuit ability can be achieved by using wide, floating P-well technique. Based on these structure advantages, the SJ-PNM-IGBT with nanoscale mesa width indicates a potentially superior overall performance towards the IGBT parameter limit.
Diffusion in the aged aluminium film on iron

Metallic coatings of many types can be applied to steel to provide outstanding, long-term corrosion protection. A thin Al film is studied at an Fe substrate by the molecular dynamics method at temperatures ranging from 300 K to 1173 K. Al atoms are found to penetrate the Fe matrix at a temperature of 873 K. The potential energy of the system changes step-like at a temperature of 1173 K. At such temperature mean square atomic displacement significantly changes. The behaviors of the Al and Fe diffusion coefficients are mainly determined by the temperature dependence of the diffusion activation energy.
Modeling of the loading path dependent magnetomechanical behavior of Galfenol alloy

The magnetomechanical behavior of single-crystal Galfenol alloy was found to be strongly dependent on the loading paths. An energy-based anisotropic domain rotation model, assuming that the interaction between domains can be ignored and the probability of the magnetic moment pointing along a particular direction is related to the free energy along this direction, is used to simulate the magnetostriction versus magnetic field and stress curve and to track the magnetic domain motion trail. The main reason for loading path dependent effect is the rotation/flipping of the magnetic domains under different loading paths. The effect of loading and unloading paths on 90° magnetic domain motion was studied by choosing different loading and unloading state and paths. The results show that prior loading magnetic field can make the 90° magnetic domains flip to the directions of 45° domains because the magnetic field is the driving force to make the domains rotate, and the final loading state and the loading path both have great influence on the motion of 90° magnetic domains.
Band structure of silicon and germanium thin films based on first principles

In nanomaterials, optical anisotropies reveal a fundamental relationship between structural and optical properties, in which directional optical properties can be exploited to enhance the performance of optoelectronic devices. First principles calculation based on density functional theory (DFT) with the generalized gradient approximation (GGA) are carried out to investigate the energy band gap structure on silicon (Si) and germanium (Ge) nanofilms. Simulation results show that the band gaps in Si (100) and Ge (111) nanofilms become the direct-gap structure in the thickness range less than 7.64 nm and 7.25 nm respectively, but the band gaps of Si (111) and Ge (110) nanofilms still keep in an indirect-gap structure and are independent on film thickness, and the band gaps of Si (110) and Ge (100) nanofilms could be transferred into the direct-gap structure in nanofilms with smaller thickness. It is amazing that the band gaps of Si~((1-x)/2)Ge~xSi~((1-x)/2) sandwich structure become the direct-gap structure in a certain area whether (111) or (100) surface. The band structure change of Si and Ge thin films in three orientations is not the same and the physical mechanism is very interesting, where the changes of the band gaps on the Si and Ge nanofilms follow the quantum confinement effects.
Graphene integrated photodetectors and opto-electronic devices— a review

Graphene and other two-dimensional materials have recently emerged as promising candidates for next-generation, high-performance photonics. In this paper, the progress of research into photodetectors and other electro-optical devices based on graphene integrated silicon photonics is briefly reviewed. We discuss the performance metrics, photo-response mechanisms, and experimental results of the latest graphene photodetectors integrated with silicon photonics. We also lay out the unavoidable performance trade-offs in meeting the requirements of various applications. In addition, we describe other opto-electronic devices based on this idea. Integrating two-dimensional materials with a silicon platform provides new opportunities in advanced integrated photonics.
Molecular Biomarker Characteristics of the Linxi Formation Source Rocks in the Middle-Western Region of Inner Mongolia: New evidence for late-stage tectonic evolution of the Paleo-Asian Ocean

Two important geological issues have long been controversial in the Xing–Meng area of North China. The first concerns the final closure of Paleo-Asian Ocean in Xing–Meng area, and the other concerns the folding and lifting of the Xing-Meng Trough. The focus of thses issues is the Late Permian sedimentary environment, which is generally considered to be either an exclusively continental environment or from the closed inland sea environment in the Early to Middle stage to continental lacustrine environment in the late stage. In recent years, we have successively discovered abundant typical marine fossils (e.g., bryozoans and calcareous algae) in the Upper Permian thick limestone layer from Linxi County and Ar Horqin Banner in eastern region of Inner Mongolia and Jiutain County in Jilin Province. These significant findings have attracted the attention from fellow academics. The thesis selected the Guandi–Zhaijiagou section of Linxi County where marine fossils were first found as the breakthrough point to conduct research. This work discussed the molecular biomarker characteristics of source rocks in Linxi Formation for further exploring the Late Permian palaeogeographical environment in the Xing–Meng area. It will provide new evidence for major geological problems about the final closure of the Paleo-Asian Ocean.
Estimation of Seismic Landslide Hazard in the Eastern Himalayan Syntaxis Region of Tibetan Plateau

The eastern Himalayan syntaxis is one of the most tectonically active and earthquake-prone regions on Earth where earthquake-induced geological disasters occur frequently and caused great damages. With the planning and construction of Sichuan-Tibet highway, Sichuan-Tibet railway and hydropower development on the Yarlung Zangbo River etc. in recent years, it is very important to evaluate the seismic landslide hazard of this region. In this paper, a seismic landslide hazard map is produced based on seismic geological background analysis and field investigation using Newmark method with 10% PGA exceedance probabilities in future 50 years by considering the influence of river erosion, active faults and seismic amplification for the first time. The results show that the areas prone to seismic landslides are distributed on steep slopes along the drainages and the glacier horns as well as ridges on the mountains. The seismic landslide hazard map produced in this study not only predicts the most prone seismic landslide areas in the future 50 years but also provides a reference for mitigation strategies to reduce the exposure of the new building and planning projects to seismic landslides.
Chemo- and Biostratigraphy of the Jurassic Oil Shales from the Qiangtang Basin, Northern Tibet, China: A Case Study of the Toarcian Oceanic Anoxic Event

The marine oil shales of the Qiangtang Basin, northern Tibet, exposed in the Biluo Co, Tuonamu, Shenglihe and Changsheshan areas are believed to be important petroleum source rocks. This work comprehensively analyzed the carbon isotopes, trace elements, and calcareous nannofosills, ammonites and bivalves of the Biluo Co section in the Qiangtang Basin. The organic carbon isotopes show a positive excursion close to 2.17‰ (relative to PDB), which, albeit significantly smaller, may also be associated with other Early Toarcian Oceanic Anoxic Events (T-OAE) in the European epicontinental seas and the Tethyan continental margins. Coinciding with the Early Toarcian transgression, the oxygen deficiency in bottom water had led to dysoxic-anoxic conditions and deposition of black shales lacking benthic fauna. Under such condition, the redox-sensitive trace metals such as Mo, V, Ni, Cr, and U were enriched, in conjunction with high planktonic productivity of Watznaueriaceae calcareous nannofossils. Comparison of the results with the records of chemo- and biostratigraphy, as well as the palaeogeography during the Early Jurassic suggests that the anoxia linked to the Early Toarcian oceanic anoxic event was mainly caused by the high surface water temperature, sea-level rise and an increase of surface water productivity.
Near-surface Geothermal Gradient Observation and Geothermal Analyses in the Xianshuihe Fault Zone, Eastern Tibetan Plateau

The Xianshuihe fault (XSHF) zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan and the 2013 Lushan earthquakes. This study analysed underground temperature sequence data for four years at seven measuring points at different depths (maximum depth: 18.9 m) in the southeastern section of the XSHF zone. High-frequency atmospheric noise was removed from the temperature sequences to obtain relatively stable temperature fields and heat fluxes near the measurement points. Our measurements show that the surrounding bedrock at (the seven stations distributed in the fault zone) had heat flux values range from –41.0 to 206 mW/m~2, with a median value of 54.3 mW/m~2. The results indicate a low heat flux in the northern section of Daofu- Kangting and a relatively high heat flux in the southern section of Kangting, which is consistent with the temperature distributions of the hot springs near the fault. Furthermore, our results suggest that the heat transfer in this field results primarily from stable underground heat conduction. In addition, the underground hydrothermal activity is also an obvious factor controlling the geothermal gradient.