mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
The Fulde-Ferrell-Larkin-Ovchinnikov states in s and d-wave superconductor with spin-dependent bandwidth imbalance on square lattice

We study numerically the phase diagram for s and d-wave fermionic superfluidity/superconductivity with spin-dependent bandwidth imbalance on a two-dimensional square-lattice. We also investigate the spontaneous space symmetry breaking states at low temperatures by solving the Bogoliubov-de Gennes equations. It is found that, the spatial configuration of the order parameter,both the uni-directional Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states and the two-dimensional FFLO state may show up in the presence of finite spin-dependent bandwidth imbalance. Moreover, we calculate the spectra of local density of states, and the experimental proposals of observing such FFLO states are therefore suggested.
An optimal fracture geometry design method of fractured horizontal wells in heterogeneous tight gas reservoirs

In this work, the unified fracture design (UFD) is extended for the first time to the fractured horizontal wells in heterogeneous closed box-shaped tight gas reservoirs. Utilizing the direct boundary element method and influence function, the dimensionless fracture productivity index is obtained and expressed in the function of proppant volume and fracture geometry at the pseudo-steady state. With the iterative method, the effectively propped permeability, k_(fe), is corrected using the in-situ Reynolds number, N_(Re). The goal of this paper is to present a new UFD extension to design the proppant volume and the optimal fracture geometry. The results show that there exists an optimal proppant volume for a certain reservoir. The small aspect ratio (y_e/x_e) and high permeability reservoirs need short and wide fractures to diminish the non-Darcy effect. On the contrary, long and narrow fractures are required for the large aspect ratio and low permeability reservoirs. A small proppant volume is prone to creating long fractures, while a relatively large proppant volume creates wide fractures. The new extension can be used to evaluate the previous fracture parameters and design the following fracture parameters of the fractured horizontal well in heterogeneous tight gas reservoirs, with the non-Darcy effect taken into account.
Characteristic of rich-mixture ignition kernel driven by nanosecond repetitive pulsed discharge

Plasma-assisted ignition is a promising technology to improve engine performance. Nanosecond repetitive pulsed discharge is widely used in plasma-assisted ignition owing to its chemical activations and thermal and hydrodynamic expansions. However, the influence of ultrafast heating and hydrodynamic effects on the development of the rich-mixture ignition kernel is largely unknown. The present study aims to illustrate these effects using electrical and schlieren measurement. The number and the frequency of discharge pulses are exactly controlled to establish the relationship among the discharge energy, frequency, and rich-mixture ignition-kernel characteristics. The evolution of the ignition kernel in the early stage is mainly dominated by the discharge energy and frequency, i.e., a greater energy and a higher frequency yield a larger ignition kernel. Moreover, the influence of both the energy and frequency on the ignition kernel gradually disappears as the ignition kernel develops. According to the experimental data and theoretical analysis, the calculated laminar burning velocity is 0.319 m/s with a Markstein length of 13.43±0.11 cm when the voltage is 5.9 kV, the frequency is 3 kHz, and the equivalence ratio is 1.3. This result indicates that the rich-mixture flame is stable in the early stage of ignition.
Numerical simulation of the segmentation of the stress state of the Anninghe-Zemuhe-Xiaojiang faults

We established a three-dimensional finite element model of the Anninghe-Zemuhe-Xiaojiang faults region using contact surfaces of different sizes to describe the spatial segmentation characteristics of the faults. Our model is based on constraints from GPS observations, models of the crust and upper mantle, precise earthquake locations, the tectonic stress field, the slip rate of the faults, and the rheology of the lithosphere in the Sichuan-Yunnan area. Considering the influence of strong earthquakes since A.D. 1327, we analyzed the main controlling factors of the characteristics of the strong earthquakes and also studied by numerical simulation the possible areas of future earthquake risk and their relationship with tectonic stress. The numerical results showed that the gravitational potential energy of the Qinghai-Tibet Plateau and the interaction of adjacent blocks are the main kinetic factors affecting the characteristics of the tectonic stress distribution. There appears to be some correspondence between the distribution of tectonic stress and the b value; however, we also found that some low b value locations correspond to regions of lower stress. This contradiction may be the result of some comprehensive factors, such as the release of strain energy caused by strong earthquakes.
Planar pn heterojunction organic light-emitting diodes

Organic light-emitting diodes (OLEDs) are being increasingly applied in flat-panel displays, such as television and mobile phones, and have great potential to become next generation solid-state lighting sources. Along with the commercialization of OLED products, scientists are devoting continuous efforts to investigate novel physical mechanisms and device configurations of OLEDs, targeting the simultaneous development of high performance (e.g. high electric-to-light conversion efficiency, good chromatic parameters to meet various requirements, and sufficiently long lifetime) and low-cost organic electroluminescent (EL) devices. One of the most attractive strategies is to construct OLEDs with low cost all-fluorescent materials, so that high cost phosphorescent materials containing rare or noble metals are not involved in device fabrication.
Effect of intensity and duration of freezing on soil microbial biomass, extractable C and N pools, and N_2O and CO_2 emissions from forest soils in cold temperate region

Freezing can increase the emissions of carbon dioxide (CO_2) and nitrous oxide (N_2O) and the release of labile carbon (C) and nitrogen (N) pools into the soil. However, there is limited knowledge about how both emissions respond differently to soil freezing and their relationships to soil properties. We evaluated the effect of intensity and duration of freezing on the emissions of CO_2 and N_2O, net N mineralization, microbial biomass, and extractable C and N pools in soils from a mature broadleaf and Korean pine mixed forest and an adjacent secondary white birch forest in northeastern China. These soils had different contents of microbial biomass and bulk density. Intact soil cores of 0–5 cm and 5–10 cm depth sampled from the two temperate forest floors were subjected to -8, -18, and -80°C freezing treatments for a short (10 d) and long (145 d) duration, and then respectively incubated at 10°C for 21 d. Soil cores, incubated at 10°C for 21 d without a pretreatment of freezing, served as control. Emissions of N_2O and CO_2 after thaw varied with forest type, soil depth, and freezing treatment. The difference could be induced by the soil water-filled pore space (WFPS) during incubation and availability of substrates for N_2O and CO_2 production, which are released by freezing. A maximum N_2O emission following thawing of frozen soils was observed at approximately 80% WFPS, whereas CO_2 emission from soils after thaw significantly increased with increasing WFPS. The soil dissolved organic C just after freezing treatment and CO_2 emission increased with increase of freezing duration, which paralleled with a decrease in soil microbial biomass C. The cumulative net N mineralization and net ammonification after freezing treatment as well as N_2O emission were significantly affected by freezing temperature. The N_2O emission was negatively correlated to soil pH and bulk density, but positively correlated to soil K_2SO_4-extractable NO_3~--N content and net ammonification. The CO_2 emission was positively correlated to the cumulative net N mineralization and net ammonification. From the above results, it can be reasonably concluded that for a wide range of freezing temperature and freezing duration, N_2O and CO_2 emissions after thaw were associated mainly with the changes in soil net N mineralization and the availability of substrate liberated by freezing as well as other soil properties that influence porosity.
Advances in studying interactions between aerosols and monsoon in China

Scientific issues relevant to interactions between aerosols and the Asian monsoon climate were discussed and evaluated at the 33rd “Forum of Science and Technology Frontiers” sponsored by the Department of Earth Sciences at the Chinese Academy of Sciences. Major results are summarized in this paper. The East Asian monsoon directly affects aerosol transport and provides a favorable background circulation for the occurrence and development of persistent fog-haze weather. Spatial features of aerosol transport and distribution are also influenced by the East Asian monsoon on seasonal, inter-annual, and decadal scales. High moisture levels in monsoon regions also affect aerosol optical and radiative properties. Observation analyses indicate that cloud physical properties and precipitation are significantly affected by aerosols in China with aerosols likely suppressing local light and moderate rainfall, and intensifying heavy rainfall in southeast coastal regions. However, the detailed mechanisms behind this pattern still need further exploration. The decadal variation in the East Asian monsoon strongly affects aerosol concentrations and their spatial patterns. The weakening monsoon circulation in recent decades has likely helped to increase regional aerosol concentrations. The substantial increase in Chinese air pollutants has likely decreased the temperature difference between land and sea, which favors intensification of the weakening monsoon circulation. Constructive suggestions regarding future studies on aerosols and monsoons were proposed in this forum and key uncertain issues were also discussed.
龙门山飞来峰前缘角砾灰岩的形成时代及构造启示

四川盆地北西缘的龙门山地区发育了一系列NE-SW走向的逆冲推覆构造, 是中国研究薄皮构造最好的天然实验室之一, 具体表现为沿着山前发育的一系列推覆体和飞来峰. 飞来峰的就位时间至今仍然存在很大争议, 主要表现为中生代推覆就位和在新生代逆冲推覆、滑覆作用或冰川作用下就位. 主体上, 这些飞来峰的下伏地层时代为晚三叠世. 但位于龙门山中段的塘坝子飞来峰, 其南东缘呈一狭长拖尾状, 不整合盖在侏罗纪及协调变形的白垩纪-新生代地层之上, 这成为龙门山飞来峰新生代就位最直接、最有力也是最重要的地层学证据.通过野外构造观察和室内岩相学分析发现, 塘坝子、白鹿顶飞来峰的前缘是一套角砾状灰岩, 为重力作用下崩塌堆积重新胶结的产物, 不具备完整地层的特点. 从角砾状灰岩胶结物中提取出中亚地区晚始新世以来特有的蒿属花粉, 表明这套飞来峰前缘的角砾状灰岩形成时代为晚始新世之后, 重新确定其时代为新生代, 并不是通常所认为的早二叠世. 目前的野外研究表明, 具有完整地层学含义而未破碎的飞来峰主体, 所覆盖的最年轻的地层时代仍然是晚三叠世. 因此角砾状灰岩与下伏侏罗纪地层的叠置关系, 不能作为判定飞来峰就位于新生代的地层学证据, 根据目前的地层叠置关系, 仅能判定飞来峰就位于晚三叠世之后. 角砾岩岩相学特征表明其为崩塌成因, 时间为晚始新世之后, 表明龙门山在这一时间发生了快速隆升.
链珠状沙波的发现及意义

提出“沙波形态-伴生底形”的命名方法, 将利用多波束测深系统对长江河口南北港分流口河槽床面形态测量时发现的由链状沙波和伴生底形-椭圆形凹坑组成的微地貌称为链珠状沙波. 初步统计了链状沙波和椭圆形凹坑的几何参数, 结果表明: 链状沙波平均波高1.29 m, 平均波长31.89 m, 沙波指数(波长/波高)介于14~56.09,背流面常发育有次级沙波, 每个沙波发育的椭圆形凹坑介于2~10个; 椭圆形凹坑最大深度为1.98 m, 最小深度为0.3 m, 平均深度为0.98 m. 对测区沙波发育环境进行了分析, 主要得出: (1)在观测的一个涨潮和落潮过程中,落潮平均流速为0.78 m s~(-1), 涨潮平均流速为0.27 m s~(-1), 落潮历时大于涨潮历时; (2)底质粒径组成较复杂, 粉砂(2~63 μm)含量介于21.6%~23.4%, 极细砂(63~125 μm)含量介于28.2%~32.2%, 细砂(125~250 μm)含量在39.7%~41.6%; (3)沙波发育区水深在13~17 m. 本研究丰富了沙波类型, 为长江河口河槽动力地貌过程的研究提供了重要的参考资料, 同时在河口工程应用中具有重要价值.
Primal-dual algorithms for total variation based image restoration under Poisson noise Dedicated to Professor Lin Qun on the Occasion of his 80th Birthday

We consider the problem of restoring images corrupted by Poisson noise. Under the framework of maximum a posteriori estimator, the problem can be converted into a minimization problem where the objective function is composed of a Kullback-Leibler (KL)-divergence term for the Poisson noise and a total variation (TV) regularization term. Due to the logarithm function in the KL-divergence term, the non-differentiability of TV term and the positivity constraint on the images, it is not easy to design stable and efficiency algorithm for the problem. Recently, many researchers proposed to solve the problem by alternating direction method of multipliers (ADMM). Since the approach introduces some auxiliary variables and requires the solution of some linear systems, the iterative procedure can be complicated. Here we formulate the problem as two new constrained minimax problems and solve them by Chambolle-Pock’s first order primal-dual approach. The convergence of our approach is guaranteed by their theory. Comparing with ADMM approaches, our approach requires about half of the auxiliary variables and is matrix-inversion free. Numerical results show that our proposed algorithms are efficient and outperform the ADMM approach.
Characteristics of air quality in Tianjin during the Spring Festival period of 2015

To better understand the characteristics of air quality and the relationship between the chemical composition evolution and source variation, an intensive atmospheric campaign was conducted in Tianjin, a megacity of the North China Plain, from 10 February to 6 March 2015. There were 20 days exceeding the threshold value of secondary Chinese Ambient Air Quality Standards for PM_(2.5) (75 μg m~(–3), daily average over 24 h) during the study period. Five air pollution episodes were selected for investigation. During the pre-holiday pollution episode, NH_4~+, NO_3~–, and SO_4~(2–) were more abundant, indicating that air pollution was caused by motor vehicle exhaust emissions and coal consumption under unfavorable meteorological conditions. During Chinese Lunar New Year’s Eve, widespread use of fireworks resulted in extremely high aerosol concentrations. Firework displays caused increases in K+ and also enrichment of SO_4~(2–) relative to NO_3~–. The holiday pollution episode was caused by regional transport, characterized by abundant SO_4~(2–) and NH_4~+. In addition, the aging processes of the particles from fireworks discharge played an important role in the formation of NO_3~– and SO_4~(2–). The Lantern Festival episode was characterized by a transition from the enrichment of K~+ to secondary inorganic ions (NO_3~–, SO_4~(2–), and NH_4~+). The results of this study are useful for a detailed understanding of the variation in atmospheric compositions and sources caused by anthropogenic activity, and highlight the importance of controlling intensive fireworks discharge.
First principle study of LiXS_2 (X = Ga, In) as cathode materials for Li ion batteries

From first principle calculations, we demonstrate that LiXS_2 (X = Ga, In) compounds have potential applications as cathode materials for Li ion batteries. It is shown that Li can be extracted from the LiXS_2 lattice with relatively small volume change and the XS_4 tetrahedron structure framework remains stable upon delithiation. The theoretical capacity and average intercalation potential of the LiGaS_2 (LiInS_2) cathode are 190.4 (144.2) mAh/g and 3.50 V (3.53 V). The electronic structures of the LiXS_2 are insulating with band gaps of 2.88 eV and 1.99 eV for X = Ga and In, respectively. However, Li vacancies, which are formed through delithiation, change the electronic structure substantially from insulating to metallic structure, indicating that the electrical conductivities of the LiXS_2 compounds should be good during cycling. Li ion migration energy barriers are also calculated, and the results show that Li ion diffusions in the LiXS_2 compounds can be as good as those in the currently widely used electrode materials.
Current-induced nonequilibrium spin polarization in semiconductor-nanowire/s-wave superconductor junctions with strong spin–orbit coupling

We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some parameter regions the magnitude of the current-induced nonequilibrium spin polarization density in such structures will increase (or decrease) with the decrease (or increase) of the charge current density, in contrast to that found in normal spin–orbit coupled semiconductor structures. It was also found that the unusual characteristics of the current-induced nonequilibrium spin polarization in such structures can be well explained by the effect of the Andreev reflection.
Evaluation of electrical and optical characteristics of ZnO/CdS/CIS thin film solar cell

In this study, device modeling and simulation are conducted to explain the effects of each layer thickness and temperature on the performance of ZnO/CdS/CIS thin film solar cells. Also, the thicknesses of the CIS and CdS absorber layers are considered in this work theoretically and experimentally. The calculations of solar cell performances are based on the solutions of the well-known three coupling equations: the continuity equation for holes and electrons and the Poisson equation. Our simulated results show that the efficiency increases by reducing the CdS thickness. Increasing the CIS thickness can increase the efficiency but it needs more materials. The efficiency is more than 19% for a CIS layer with a thickness of 2 μm. CIS nanoparticles are prepared via the polyol route and purified through centrifugation and precipitation processes. Then nanoparticles are dispersed to obtain stable inks that could be directly used for thin-film deposition via spin coating. We also obtain x-ray diffraction (XRD) peak intensities and absorption spectra for CIS experimentally. Finally, absorption spectra for the CdS window layer in several deposition times are investigated experimentally.
Fabrication of CoFe_2O_4 ferrite nanowire arrays in porous silicon template and their local magnetic properties

CoFe_2O_4 ferrite nanowire arrays are fabricated in porous silicon templates. The porous silicon templates are prepared via metal-assisted chemical etching with gold (Au) nanoparticles as the catalyst. Subsequently, CoFe_2O_4 ferrite nanowires are successfully synthesized into porous silicon templates by the sol–gel method. The magnetic hysteresis loop of nanowire array shows an isotropic feature of magnetic properties. The coercivity and squareness ratio (M_r/M_s) of ensemble nanowires are found to be 630 Oe (1 Oe = 79.5775 A·m~(-1) and 0.4 respectively. However, the first-order reversal curve (FORC) is adopted to reveal the probability density function of local magnetostatic properties (i.e., interwire interaction field and coercivity). The FORC diagram shows an obvious distribution feature for interaction field and coercivity. The local coercivity with a value of about 1000 Oe is found to have the highest probability.
Tunable acoustic radiation pattern assisted by effective impedance boundary

The acoustic wave propagation from a two-dimensional subwavelength slit surrounded by metal plates decorated with Helmholtz resonators (HRs) is investigated both numerically and experimentally in this work. Owing to the presence of HRs, the effective impedance of metal surface boundary can be manipulated. By optimizing the distribution of HRs, the asymmetric effective impedance boundary will be obtained, which contributes to generating tunable acoustic radiation pattern such as directional acoustic beaming. These dipole-like radiation patterns have high radiation efficiency, no fingerprint of sidelobes, and a wide tunable range of the radiation pattern directivity angle which can be steered by the spatial displacements of HRs.
Passively mode-locked erbium-doped fiber laser via a D-shape-fiber-based MoS_2 saturable absorber with a very low nonsaturable loss

We report on the generation of conventional and dissipative solitons in erbium-doped fiber lasers by the evanescent field interaction between the propagating light and a multilayer molybdenum disulfide (MoS_2) thin film. The MoS_2 film is fabricated by depositing the MoS_2 water–ethanol mixture on a D-shape-fiber (DF) repetitively. The measured nonsaturable loss, saturable optical intensity, and the modulation depth of this device are 13.3%, 110 MW/cm~2, and 3.4% respectively. Owing to the very low nonsaturable loss, the laser threshold of conventional soliton is as low as 4.8mW. The further increase of net cavity dispersion to normal regime, stable dissipation soliton pulse trains with a spectral bandwidth of 11.7 nm and pulse duration of 116 ps are successfully generated. Our experiment demonstrates that the MoS_2-DF device can indeed be used as a high performance saturable absorber for further applications in ultrafast photonics.
Application of long-range correlation and multi-fractal analysis for the depiction of drought risk

By using the multi-fractal detrended fluctuation analysis method, we analyze the nonlinear property of drought in southwestern China. The results indicate that the occurrence of drought in southwestern China is multi-fractal and longrange correlated, and these properties are indifferent to timescales. A power-law decay distribution well describes the return interval of drought events and the auto-correlation. Furthermore, a drought risk exponent based on the multi-fractal property and the long-range correlation is presented. This risk exponent can give useful information about whether the drought may or may not occur in future, and provide a guidance function for preventing disasters and reducing damage.
Brief overview of electrochemical potential in lithium ion batteries

The physical fundamentals and influences upon electrode materials’ open-circuit voltage (OCV) and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate that a better understanding of these scientific problems can help to develop and design high voltage cathodes and interfaces with low Ohmic drop. OCV is one of the main indices to evaluate the performance of lithium ion batteries (LIBs), and the enhancement of OCV shows promise as a way to increase the energy density. Besides, the severe potential drop at the interfaces indicates high resistance there, which is one of the key factors limiting power density.
High-throughput theoretical design of lithium battery materials

The rapid evolution of high-throughput theoretical design schemes to discover new lithium battery materials is reviewed, including high-capacity cathodes, low-strain cathodes, anodes, solid state electrolytes, and electrolyte additives. With the development of efficient theoretical methods and inexpensive computers, high-throughput theoretical calculations have played an increasingly important role in the discovery of new materials. With the help of automatic simulation flow, many types of materials can be screened, optimized and designed from a structural database according to specific search criteria. In advanced cell technology, new materials for next generation lithium batteries are of great significance to achieve performance, and some representative criteria are: higher energy density, better safety, and faster charge/discharge speed.
Interfacial transport in lithium-ion conductors

Physical models of ion diffusion at different interfaces are reviewed. The use of impedance spectroscopy (IS), nuclear magnetic resonance (NMR), and secondary ion mass spectrometry (SIMS) techniques are also discussed. The diffusion of ions is fundamental to the operation of lithium-ion batteries, taking place not only within the grains but also across different interfaces. Interfacial ion transport usually contributes to the majority of the resistance in lithium-ion batteries. A greater understanding of the interfacial diffusion of ions is crucial to improving battery performance.