Modern and contemporary literature in colleges and universities is a deeply learned and traditional humanities subject, and the development of Internet technology has a different impact on the form ...of teaching literature. This paper combines the MOOC platform for information technology with the teaching of modern and contemporary literature and establishes a blended teaching mode for both modern and contemporary literature. Aiming at the problem of personalized recommendation of literature teaching resources in blended teaching, this paper introduces the singular value decomposition to improve the collaborative filtering algorithm in order to meet the students’ efficient learning needs of current and contemporary literature. After the teaching experiment of the blended teaching mode of current and modern literature for the students of the class of 2021 in the sample universities, the reading breadth score of the students in the experimental group in current and contemporary literature reaches 3.72±0.61. The reading ability of the two groups of students shows a significant difference at the 1% level. Furthermore, students in the experimental group were 0.3 points more motivated to learn modern and contemporary literature than those in the control group. The integration of current and modern literature teaching with information technology can promote students’ learning interests and improve the quality of current and contemporary literature teaching.
Head pose estimation (HPE) has wide industrial applications, such as online education, human-robot interaction, and automatic manufacturing. In this article, we address two key problems in HPE based ...on label learning and asymmetric relation cues: 1) how to bridge the gap between the better prediction performance of networks and incorrectly label pose images in the HPE datasets and 2) how to take full advantage of the adjacent poses information around the centered pose image. We reconstruct all the incorrect labels as a two-dimensional Lorentz distribution to tackle the first problem. Instead of directly adopting the angle values as hard labels, we assign part of the probability values ( soft labels) to adjacent labels for learning discriminative feature representations. To address the second problem, we reveal the asymmetric relation nature of HPE datasets. The yaw direction and pitch direction are assigned different weights by introducing the half at half-maximum of the Lorentz distribution. Compared with the traditional end-to-end frameworks, the proposed one can leverage the asymmetric relation cues for predicting the head pose angle in the incorrect label scenarios. Extensive experiments on two public datasets and our infrared dataset demonstrate that the proposed ARHPE network significantly outperforms other state-of-the-art approaches.
Highly efficient and stable 2D/3D hybrid perovskite solar cells using 2‐thiophenemethylammonium (ThMA) as the spacer cation are successfully demonstrated. It is found that the incorporation of ThMA ...spacer cation into 3D perovskite, which forms a 2D/3D hybrid structure, can effectively induce the crystalline growth and orientation, passivate the trap states, and hinder the ion motion, resulting in improved carrier lifetime and reduced recombination losses. The optimized device exhibits a power conversion efficiency (PCE) of 21.49%, combined with a high VOC of 1.16 V and a notable fill factor (FF) of 81%. More importantly, an encapsulated 2D/3D hybrid perovskite device sustains ≈99% of its initial PCE after 1680 h in the ambient atmosphere, whereas the control 3D perovskite device drops to ≈80% of the original performance. Importantly, the device stability under continuous light soaking (100 mW cm−2) is enhanced significantly for 2D/3D perovskite device in comparison with that of the control device. These results reveal excellent photovoltaic properties and intrinsic stabilities of the 2D/3D hybrid perovskites using ThMA as the spacer cation.
2‐Thiophenemethylammonium spacer cations are successfully embedded into formamidinium iodide (FAI)‐ and methylammonium iodide (MAI)‐based 3D perovskites, and these cations can induce the crystalline growth and orientation of the obtained 2D/3D hybrid perovskite. A champion efficiency of 21.49% is demonstrated for a 2D/3D perovskite device, which is combined with a dramatically improved stability in comparison with that of the control device.
A total of 30 samples from the downwind direction of a certain electroplating company in Jiaxing were collected in layers to analyze their heavy metal content. The soil risk assessment was conducted ...from the perspective of ecological and human health risks using the ground accumulation index method and human health risk assessment method. The results showed that in all samples, cadmium and arsenic far exceeded the soil background values, with an average exceeding multiple of 14.31 and 64.42, respectively, and a exceeding rate of 100%. After evaluation by the ground accumulation index, among these six heavy metals, arsenic and cadmium belong to extremely serious pollution levels. The human health risk assessment of electroplating plants found that in the exposure risk assessment, the ingestion value was much greater than the harm caused by breathing and skin, and the maximum exposure damage value of arsenic to children and adults was 4.17 × 10
, among the carcinogenic risks, the risk brought by consumption is much greater than the respiratory and skin carcinogenic risk index, with the highest value score of 3.37 for cadmium, arsenic, and zinc carcinogenic risks 3.37 × 10
, 2.42 × 10
, 1.10 × 10
.
•A method determining methane and water vapor permeability in shale is proposed.•The evolution of methane and water vapor permeability is analyzed and compared.•The relationship between permeability ...and water saturation of shale is presented.
Methane and water vapor transport in shale (mud rocks) is important in many resource and environmental issues, e.g., effectively exploiting shale gas and clearly understanding water and methane global cycles. To investigate methane and water vapor permeability in shale, a new permeability determination method was proposed using a linearization approach based on previous studies. The experimental samples are crushed Carboniferous shale from the eastern Qaidam Basin in China. Simultaneous methane and water vapor transport experiments in shale were performed. Water vapor was derived through deionized water evaporation under different methane pressures. The relative humidity dynamically changed during the experiment. The methane and water vapor transport processes were observed and recorded, and the methane and water vapor permeability in the shale matrix was calculated. Both the methane and water vapor permeabilities temporally varied, and a critical abrupt point occurred in the decreasing process over time. After the abrupt point, the permeability rapidly decreased, which was mainly due to capillary condensation plugging at high relative humidities. Pore throat closure could dramatically affect permeability. The relationship between permeability and water saturation (Sw) conformed to an exponential equation. Methane permeability was sensitive to water saturation variation at very low or high levels (Sw <20 % or Sw >50 %, respectively) and relatively insensitive at a moderate water content. Water vapor permeability variation with water saturation was similar to that in methane but basically remained stable at a moderate water saturation (10 % <Sw < 50%). At high water saturations, water vapor permeability reduction was more sensitive than that in methane.
Recently, RNA-guided genome editing using the type II clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) system has been applied to edit the plant genome in ...several herbaceous plant species. However, it remains unknown whether this system can be used for genome editing in woody plants. In this study, we describe the genome editing and targeted gene mutation in a woody species, Populus tomentosa Carr. via the CRISPR/Cas9 system. Four guide RNAs (gRNAs) were designed to target with distinct poplar genomic sites of the phytoene desaturase gene 8 (PtoPDS) which are followed by the protospacer-adjacent motif (PAM). After Agrobacterium-mediated transformation, obvious albino phenotype was observed in transgenic poplar plants. By analyzing the RNA-guided genome-editing events, 30 out of 59 PCR clones were homozygous mutants, 2 out of 59 were heterozygous mutants and the mutation efficiency at these target sites was estimated to be 51.7%. Our data demonstrate that the Cas9/sgRNA system can be exploited to precisely edit genomic sequence and effectively create knockout mutations in woody plants.
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In recent years, the aluminum alloys parts produced by Selective Laser Melting (SLM) are increasingly used instead of casting aluminum alloys parts in the automotive, aerospace and ...other fields. However, the high surface roughness of the vertical surfaces is a major issue influencing the application of SLM for aluminum. Moreover, most of the methods to reduce the surface roughness, such as polishing, bead blasting or machining, will increase the production delays and costs. The present study aims at evaluating the effect of linear energy density on the surface roughness of the vertical planes. Both deposited tracks and volumetric specimens were produced and the morphologies and the surface roughnesses were measured. The obtained results indicate that the surface roughness of the vertical planes was reduced to 4 μm from 15 μm when deposited a suitable linear energy density, reducing the surface roughness by more than 70%. The surface morphologies and the height change rate of the deposited tracks had a significant influence on the surface roughness. Furthermore, for experiments with the same linear energy density, the surface roughness was improved with higher laser power.
It is significantly important to design enzyme-free electrocatalyst for sensitive and selective detection of glucose (Glu). In this paper, we report that metallic nickel nitride nanosheet on Ti mesh ...(Ni3N NS/Ti) behaves as an efficient three-dimensional catalyst electrode for Glu electro-oxidation under alkaline conditions. We further demonstrate the use of such Ni3N NS/Ti as a non-enzymatic electrochemical Glu sensor superior in analytical performances. The introduction of the Ni3N NS/Ti can provide a high surface area and lead to high sensitivity to Glu. This sensor shows a fast amperometric response toward Glu and can achieve steady state current density within 5s, a detection range of 0.2μM–1.5mM, a detection limit of 0.06μM (S/N=3), a response sensitivity of 7688μAmM−1cm−2, and satisfactory selectivity and reproducibility. In addition, it also works effectively for Glu detection in human blood serum, promising its application toward determination of Glu in real samples.
In this paper, we analyze the feasibility of linear interference alignment (IA) for multi-input-multi-output (MIMO) interference broadcast channel (MIMO-IBC) with constant coefficients. We pose and ...prove the necessary conditions of linear IA feasibility for general MIMO-IBC. Except for the proper condition, we find another necessary condition to ensure a kind of irreducible interference to be eliminated. We then prove the necessary and sufficient conditions for a special class of MIMO-IBC, where the numbers of antennas are divisible by the number of data streams per user. Since finding an invertible Jacobian matrix is crucial for the sufficiency proof, we first analyze the impact of sparse structure and repeated structure of the Jacobian matrix. Considering that for the MIMO-IBC the sub-matrices of the Jacobian matrix corresponding to the transmit and receive matrices have different repeated structure, we find an invertible Jacobian matrix by constructing the two sub-matrices separately. We show that for the MIMO-IBC where each user has one desired data stream, a proper system is feasible. For symmetric MIMO-IBC, we provide proper but infeasible region of antenna configurations by analyzing the difference between the necessary conditions and the sufficient conditions of linear IA feasibility.
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