Preparation of SBS Modified Emulsified Asphalt in High Cold Region

A kind of SBS modified emulsified asphalt for highly cold area was studied by experiments. The research includes two aspects: the first is preparation of SBS modified asphalt. The influence of temperature, time, shear rate and development time on asphalt modification are determined, so as to determine the process of SBS modified asphalt. On this basis, the blending ratio of SBS modified emulsified asphalt was determined by experiments. The results show that the emulsified asphalt produced by the equipment is of good quality and good ductility.4%SBS latex content can make emulsified asphalt meet the standard requirements, but only 6%SBS latex content can obtain better road performance. Although the softening point of SBS modified emulsified asphalt prepared by this method is still low, it can meet the requirements of high cold area

Conservation and diversification of the miR166 family in soybean and potential roles of newly identified miR166s

Identity between pre-miR166s in soybean. (TIF 5906 kb

Can LMs Generalize to Future Data? An Empirical Analysis on Text Summarization

Recent pre-trained language models (PLMs) achieve promising results in existing abstractive summarization datasets. However, existing summarization benchmarks overlap in time with the standard pre-training corpora and finetuning datasets. Hence, the strong performance of PLMs may rely on the parametric knowledge that is memorized during pre-training and fine-tuning. Moreover, the knowledge memorized by PLMs may quickly become outdated, which affects the generalization performance of PLMs on future data. In this work, we propose TempoSum, a novel benchmark that contains data samples from 2010 to 2022, to understand the temporal generalization ability of abstractive summarization models. Through extensive human evaluation, we show that parametric knowledge stored in summarization models significantly affects the faithfulness of the generated summaries on future data. Moreover, existing faithfulness enhancement methods cannot reliably improve the faithfulness of summarization models on future data. Finally, we discuss several recommendations to the research community on how to evaluate and improve the temporal generalization capability of text summarization models.Comment: Accepted at EMNLP 202

Improving the efficiency of small-scale wastewater treatment by pneumatic agitation

Small-scale anaerobic and aerobic systems for wastewater treatment suffer relatively low efficiencies due primarily to a lack of mechanical agitation/mixing. Here, a pneumatic agitation system was designed by installing a U-tube between the anaerobic and anoxic units, pumping air to the closed headspace of the anaerobic unit and releasing the pressurized air through the U-tube to create turbulence of the fluid. Computational Fluid Dynamics (CFD) simulation and fluid tracer trial were used to describe the fluid status in a lab-scale system (13 L). The results demonstrated that a continuous 5-cycle pneumatic agitation achieved a complete mixing of the static fluid. The retention time factor () and short-circuiting flow coefficient (/HRT) were increased from 0.93 to 1.14 and 0.02 to 0.27, respectively, indicating that pneumatic agitation significantly reduced dead zone and short-circuiting flow. A prototype at a treatment capacity of 300 L/d was installed in the North-East suburb of Beijing (40.15° N, 116.95° E) to treat rural household wastewater consisting of 630–1200 mg/L chemical oxygen demand and 20–45 mg/L total nitrogen. The field test was monitored in a period of 75 days from September to November 2018. The average removal rate for COD and TN was 96% and 92%, respectively by 10 times/h pneumatic agitation as compared to 49% and 45% without pneumatic agitation. The pneumatic agitation provides a low cost, easy operation and maintenance and efficient means for small-scale domestic wastewater treatment

A Fully Coupled Model for the Simulation of Gas Flow in Multiscale Shale Reservoirs Combining Multiple Effects

Gas flow mechanisms in shale reservoirs with multiscale pores and fractures are extremely complex. In this study, a dual fracture framework model was adopted to describe gas flow in multiscale shale reservoirs. Gas flow through a shale reservoir occurs through both the shale matrix and hydraulic fractures. This study considered bulk phase and adsorbed gas flow in the shale matrix. Next, a series of partial theories were combined to derive a fully coupled model simulating gas flow in multiscale shale reservoirs: (1) fractal theory was adopted to obtain the pore distribution within shale reservoirs; (2) mechanical equilibrium equations were used to investigate the stress-sensitivity of permeability and porosity; and (3) a Langmuir adsorption model was applied to describe the effects of gas adsorption/desorption. The proposed model was validated using traditional models as well as field data on gas production from Marcellus Shale, and was subsequently applied to study variations of mass flux in various flow regimes with respect to reservoir pressure. We found that mass flux in the slip flow regime decreased at first and then increased with decreasing reservoir pressure, while in the continuum regime, Knudsen diffusion and surface diffusion the mass flux decreased with decreasing reservoir pressure. Stress-sensitivity has a significant impact on bulk phase gas flow, while adsorption/desorption influence both the bulk phase gas flow and adsorbed gas flow. At high pressures, the impact of stress-sensitivity on total gas mass flux is greater than that of adsorption/desorption, while the reverse was true for low pressures. The proposed model shows promising applications for analyzing various gas flow regimes in multiscale pores/fractures, and accurately evaluating in situ apparent permeability

Metoda za optimizacijo večparametrske sklopitve pri hidravlični valjalni oblikovalni napravi na podlagi faktorske zasnove

A hydraulic rolling reshaper is an advanced shaping technology with superior protection for casings, and the structural parameters of the reshaper affect its shaping effect on deformed casing directly. To improve the shaping capacity of the reshaper, a multi-parameter coupling optimization method of hydraulic rolling reshaper is proposed to optimize the design of the factors with significant influence under the premise of screening multi-structural parameters. In this paper, according to the working principle of the reshaper, considering the contact nonlinearity between the hydraulic rolling reshaper and deformed casing, as well as the material nonlinearity of the casing, a parametric finite element model of the hydraulic rolling reshaper repairing the shrinkage deformation of casings was developed. The remarkable factors were screened by factorial design, the sample points were generated by optimal Latin hyper-cube design (OLHD), and the response surface models were established by stepwise regression. Therefore, with the maximum plastic deformation of casings as the objective function, the maximum equivalent stress, residual stress, and the plastic deformation of casings as the constrained conditions, an optimized mathematical model for a reshaper was constructed, and the genetic algorithm (GA) is performed to obtain the optimal combination of parameters. The results showed that the optimal reshaper made the shaping process safe and effective, the plastic deformation of casings after single shaping was increased by 11.38 %, and the shaping effect was better (96.48 %), which can effectively improve the safety performance and shaping ability of the reshaper

Elastic anisotropy and phonon focusing in NiAl: Atomic study

Natural Science Foundation of the Education Department of Henan Province of China [2009B590001]; Henan Science and Technology Agency of China [092102210314, 132102210207]; State Key Laboratory of Superhard Materials (Jilin University) [201107]; National Natural Science Foundation of China [11104127]We have investigated the anisotropy and phonon focusing of NiAl using ultrasoft pseudopotentials within the generalized gradient approximation correction in the frame of density functional theory. Theoretical calculation of the three dimensional slowness surfaces gives insights into the mixing of longitudinal and transverse modes and shows the origin of the phonon caustics. The phonon focusing due to the elastically anisotropy, and the phonon phase and group velocities are explained. In general, the propagation of elastic waves in crystals is strongly affected by the elastic anisotropy of the lattice. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved