RecapNet: Action Proposal Generation Mimicking Human Cognitive Process

International audienceGenerating action proposals in untrimmed videos is a challenging task, since video sequences usually contain lots of irrelevant contents and the duration of an action instance is arbitrary. The quality of action proposals is key to action detection performance. The previous methods mainly rely on sliding windows or anchor boxes to cover all ground-truth actions, but this is infeasible and computationally inefficient. To this end, this article proposes a RecapNet--a novel framework for generating action proposal, by mimicking the human cognitive process of understanding video content. Specifically, this RecapNet includes a residual causal convolution module to build a short memory of the past events, based on which the joint probability actionness density ranking mechanism is designed to retrieve the action proposals. The RecapNet can handle videos with arbitrary length and more important, a video sequence will need to be processed only in one single pass in order to generate all action proposals. The experiments show that the proposed RecapNet outperforms the state of the art under all metrics on the benchmark THUMOS14 and ActivityNet-1.3 datasets. The code is available publicly at https://github.com/tianwangbuaa/RecapNet

Distributed optimization of nonlinear singularly perturbed multi-agent systems via a small-gain approach and sliding mode control

This paper addressed the challenging problem of distributed optimization for nonlinear singular perturbation multi-agent systems. The main focus lies in steering the system outputs toward the optimal points of a globally objective function, which was formed by the combination of several local functions. To achieve this objective, the singular perturbation multi-agent system was initially decomposed into fast and slow subsystems. Compared to traditional methods, robustness in reference-tracking signals was ensured through the design of fast-slow sliding mode controllers. Additionally, our method ensured robustness against errors between reference signals and optimal values by employing a distributed optimizer to generate precise reference signals. Furthermore, the stability of the entire closed-loop system was rigorously guaranteed through the application of the small-gain theorem. To demonstrate the efficacy of the proposed approach, a numerical example was presented, providing empirical validation of its effectiveness in practical scenarios

Sheep manure organic fertilizer is an effective strategy to promote strawberry growth by improving soil physicochemical properties and microbiota

The use of organic fertilizers instead of chemical fertilizers can improve soil pH, help to maintain soil health and enable landowners to achieve organic or ecological-status agriculture. Rapeseed cake, sheep manure, and biofungal fertilizer are considered to be effective amendments to improve soil quality. However, there have been few studies on the effects of the three fertilizers on strawberry production, soil physicochemical properties, and inter-root soil microbial community structure. In this study, field experiments were conducted to investigate the differences in strawberry growth, quality, yield, and the structure and diversity of strawberry soil bacterial and fungal communities under four treatments: no organic fertilizer (CK), rapeseed cake organic fertilizer (T1), sheep manure organic fertilizer (T2) and bio-organic fertilizer (algae-optimized bacteria) (T3), the relationship between soil physicochemical properties and soil microbial diversity were analyzed. Our results have shown that these three amendments promoted the growth of strawberry to some extent. The effects of available phosphorus, ammonium nitrogen, sucrase, protease and urease under T2 treatment were significantly increased by 50.62%, 54.14%, 276.50%, 129.47%, 232.61%, and 232.00%, respectively, compared with the control. The soil bacterial and fungi community were the most abundant and diversified under the T2 treatment. Soil physicochemical properties and soil key enzyme activities varied significantly under different fertilizer treatments, with the soil nutrient content and soil carbon and nitrogen metabolizing enzyme activities being highest under T2 treatment. A Pearson correlation analysis showed that soil organic matter was closely related to the diversity of soil microbial communities. A redundancy analysis (RDA) showed that the main variables of the bacterial community included nitrate nitrogen (NN) and rapidly available potassium (RAP), while the main variables of the fungal community included alkaline dissolved nitrogen (ADN) and ammonium nitrogen (AN). Overall, different fertilizers promoted the release and transformation of soil nutrients by affecting the structure and diversity of bacterial and fungal communities in strawberry soils, which was beneficial to the supply of soil nutrients and the improvement of soil quality. The application of sheep manure organic fertilizer had the best soil improvement effect

A comparative photocatalytic study of TiO2 loaded on three natural clays with different morphologies

[EN] In this work, a sol-gel method was used to load TiO2 nanoparticles on three clays (kaolinite, halloysite and palygorskite) with different morphologies (plates, tubes, and rods with micro tunnels), and then the photocatalytic performance of obtained clay-TiO2 composites for degradation of methyl orange was comparatively investigated. The results surprisingly show that the trend of photocatalytic performance of composites is opposite to that of special surface area of corresponding clays. By concentrated analysis of the loading status of TiO2, the lowest photocatalytic efficiency of palygorskite-TiO2 composite is mainly ascribed to (1) the aggregation of TiO2 nanoparticles on Pal surface, not the amount of TiO2 and (2) the relatively weak adsorption of Pal to methyl orange. The additional adsorption of hydroxyl surface of Kaol to methyl orange and little TiO2 in the lumen of Hal tube leads to the better photocatalytic performance of kaolinite-TiO2 composite than halloysite-TiO2 composite. Finally, kaolinite is proved to be an excellent carrier to support nano TiO2 resulting in a good photocatalytic performance and cycle stability, and the study can provide a direct guidance to select appropriate clay-photocatalyst composites for different practical applications.This work is supported by the National Natural Science Foundation of China (41502032) and the Fundamental Research Funds for the Central Universities (2019XKQYMS76).Wu, A.; Wang, D.; Wei, C.; Zhang, X.; Liu, Z.; Feng, P.; Ou, X.... (2019). A comparative photocatalytic study of TiO2 loaded on three natural clays with different morphologies. Applied Clay Science. 183:1-12. https://doi.org/10.1016/j.clay.2019.105352S11218

Draft genome sequence of the mulberry tree Morus notabilis

Human utilization of the mulberry–silkworm interaction started at least 5,000 years ago and greatly influenced world history through the Silk Road. Complementing the silkworm genome sequence, here we describe the genome of a mulberry species Morus notabilis. In the 330-Mb genome assembly, we identify 128 Mb of repetitive sequences and 29,338 genes, 60.8% of which are supported by transcriptome sequencing. Mulberry gene sequences appear to evolve ~3 times faster than other Rosales, perhaps facilitating the species’ spread worldwide. The mulberry tree is among a few eudicots but several Rosales that have not preserved genome duplications in more than 100 million years; however, a neopolyploid series found in the mulberry tree and several others suggest that new duplications may confer benefits. Five predicted mulberry miRNAs are found in the haemolymph and silk glands of the silkworm, suggesting interactions at molecular levels in the plant–herbivore relationship. The identification and analyses of mulberry genes involved in diversifying selection, resistance and protease inhibitor expressed in the laticifers will accelerate the improvement of mulberry plants

The application of Fiber Bragg Grating sensor to high precision temperature measurement

Basing on the character that Fiber Bragg Grating (FBG) is sensitive to both temperature and strain, by using Al and Fe-Ni alloy’s bimetal structure, we successfully design and manufacture a high accuracy FBG temperature sensor for earthquake premonition. Furthermore, we analyze the accuracy of the FBG sensors with enhanced sensitivity for the first time, and get its accuracy is up to ±0.05℃ with highest resolution ever in all FBG temperature sensors (0.0014℃/pm). This work experimentally proves the feasibility of using FBG in the earthquake premonition monitoring, and builds the foundation for the application of optic technology in earthquake premonition monitoring

Pickling Behavior of Duplex Stainless Steel 2205 in Hydrochloric Acid Solution

The oxide-scale structure and pickling behavior of oxided 2205 duplex stainless steel in the electrolytes containing hydrochloric acid were investigated. The oxide scales mainly consist of two layers: the outer layer is dense Fe2O3, and the inner granular is FeCr2O4 spinel. During the pickling process, pittings form around the boundaries of FeCr2O4 particles or interfaces of two kinds of oxides, which results in that the electrolyte can directly react with the chromium-depleted layer along the pittings to produce an “undercut” effect so that the pickling efficiency is improved markedly. The pickling mechanism was discussed, and the model was established

A high sensitive fiber Bragg grating cryogenic temperature sensor

At cryogenic temperature, a fiber Bragg grating (FBG) temperature sensor with controllable sensitivity and variable measurement range is demonstrated by using bimetal configuration. In experiments, sensitivities of -51.2, -86.4, and -520 pm/K are achieved by varying the lengths of the metals. Measurement ranges of 293-290.5, 283-280.5, and 259-256.5 K are achieved by shortening the distance of the gap among the metals