Pine wood nematode disease is a devastating pine disease that poses a great threat to forest ecosystems. The use of remote sensing methods can achieve macroscopic and dynamic detection of this ...disease; however, the efficiency and accuracy of traditional remote sensing image recognition methods are not always sufficient for disease detection. Deep convolutional neural networks (D-CNNs), a technology that has emerged in recent years, have an excellent ability to learn massive, high-dimensional image features and have been widely studied and applied in classification, recognition, and detection tasks involving remote sensing images. This paper uses Gaofen-1 (GF-1) and Gaofen-2 (GF-2) remote sensing images of areas with pine wood nematode disease to construct a D-CNN sample dataset, and we train five popular models (AlexNet, GoogLeNet, SqueezeNet, ResNet-18, and VGG16) through transfer learning. Finally, we use the “macroarchitecture combined with micromodules for joint tuning and improvement” strategy to improve the model structure. The results show that the transfer learning effect of SqueezeNet on the sample dataset is better than that of other popular models and that a batch size of 64 and a learning rate of 1 × 10−4 are suitable for SqueezeNet’s transfer learning on the sample dataset. The improvement of SqueezeNet’s fire module structure by referring to the Slim module structure can effectively improve the recognition efficiency of the model, and the accuracy can reach 94.90%. The final improved model can help users accurately and efficiently conduct remote sensing monitoring of pine wood nematode disease.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Superhydrophobic polyvinylidene fluoride (PVDF) microporous membranes with micro-nano hierarchical structure were prepared by combining immersion precipitation with rolling embossing. This method was ...primarily consisted of semi-gelation process, rolling embossing process and water bath gelation process. The introduction of the semi-gelation process ensured the successful rolling embossing. The membranes were characterized by XRD, SEM, AFM, contact angle, pore size, porosity, N2 flux, and mechanical stability. The results indicated that the water contact angle and the sliding angle of the embossed membrane prepared under the optimal conditions were 151.2° and 5.4°, respectively. The N2 flux of the embossed membrane was higher than that of un-embossed membrane, and the micro-nano hierarchical structure had excellent mechanical stability. The synergy of mechanical properties, porosity, pore sizes and hydrophobicity made embossed membranes suitable for vacuum membrane distillation (VMD) applications. Compared with the un-embossed membrane, the embossed membrane showed better desalination performance and anti-fouling ability. The embossed membrane had a permeation flux of 24.81 kg/m2·h and a 99.9% rejection rate. Fouling was difficult to deposit on the membrane surface and was easy to clean, indicating great potential for applications in VMD. This novel method provides the possibility for the large-scale continuous preparation of superhydrophobic PVDF microporous membranes.
Herein we proposed a novel approach of preparing superhydrophobic PVDF microporous membranes via combining immersion precipitation with rolling embossing. Firstly, the semi-gelation state of the membrane was adjusted by semi-gelation time and NMP content in semi-gelation agent in the semi-gelation process. Then, the semi-gelation membrane surface was embossed by a roller with microstructure, the membrane surface successfully replicates the microstructure of the roller. Finally, in the gelation process with water bath, the micro-nano hierarchical structure was successfully constructed on the membrane surface through the combination of the nano-scale structure generated by phase separation and the micro-scale structure obtained by rolling. This approach provides viability for large-scale continuous preparation of superhydrophobic PVDF microporous membranes. Display omitted
•Superhydrophobic PVDF microporous membrane is prepared by combining immersion precipitation with rolling embossing method.•The introduction of the semi-gelation process ensures the successfully rolling embossing process.•Under long-term VMD tests, the embossed membrane showed excellent desalination performance and anti-fouling ability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With the improvement of image resolution in synthetic aperture radars (SARs), sea clutter characteristics become more complex, which poses new challenges to traditional ship target detection ...missions. In this paper, to detect ship targets quickly and efficiently in a complex background, we propose an adaptive hierarchical detection method based on a coarse-to-fine mechanism. This method constructs a new visual attention mechanism to strengthen ship targets and obtain the candidate targets adaptively by the means dichotomy method. On this basis, the precise detection results of the targets are obtained using the speed block kernel density estimation method, which maintains constant false alarm characteristics. Compared with existing methods, the adaptive hierarchical detection method has simple, fast, and accurate characteristics. Experiments based on GF-III satellite and airborne SAR datasets are presented to demonstrate the effectiveness of the proposed method.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•The overall average annual occurrence of FBHs in China was 11,420 thousand hectares.•The pattern of FBHs prevalence in “heavy in the north and light in the south”.•Incidence of FBHs in prefectures ...with “patchy outbreak” to “multi-point aggregation”.•FBHR of prefecture-level cities showing an circular spatial scattering pattern.
To date, there is a lack of fine-scale forest biological hazard risk (FBHR) data for Chinese forests on a national scale. This study explored the spatial and temporal patterns of the FBHR in prefecture-level cities in China. Data on the forest biological hazard (FBH) damage area and forest cover area of each prefecture-level city in China from 2007 to 2019 were used. Based on the statistical analysis characteristics of the FBH rate of each prefecture-level city in recent years, the spatial pattern of the FBHR of prefecture-level cities in China was obtained by optimal fitting. The results of the study show that the overall average annual occurrence of FBHs in China from 2007 to 2019 was 11,420 thousand hectares. Although the incidence rate showed a decreasing trend, the occurrence area showed a decreasing and then increasing trend. The incidence of FBHs in each prefecture-level city in China showed a pattern of “heavy in the north and light in the south”; the overall incidence of FBHs showed a pattern of “high in the central part and low in the north and south”. The FBHR at the prefecture level in China showed a circular scattering spatial pattern, and significant geographical differences were observed, with an average annual expected incidence of approximately 1.3‰. Among them, the highest FBHR at the prefecture level, was mainly concentrated along the Henan, Anhui and Shandong borders. A high FBHR was distributed in the Jiangsu, Xinjiang, and Ningxia-Neimenggu areas. A medium FBHR was distributed in the North China Plain, Liaoning and Sichuan. A low FBHR was distributed in Central China, North China, Xinjiang and Liaoning. An extremely low FBHR was concentrated in Heilongjiang-Jilin-Qinghai-Gansu, southern East China, Southwest China and South China. The results of this study reveal the FBHR patterns on a refined scale in China and provide a reference for managing, preventing, and controlling the FBH.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the present study, the concentration and accumulation abilities of five heavy metals (Cd, Hg, As, Pb, Cr) in rice were assessed and their human health risk to local citizens had been evaluated. ...Soil and rice samples (125 samples) were collected from Guiyang (GY), Qiannan (QN), Bijie (BJ), Tongren (TR), and Zunyi (ZY) in Guizhou Province. Heavy metals were measured by inductively coupled plasma–mass spectrometry (ICP-MS) after microwave digestion. The mean concentrations of Cd, Hg, As, Pb, and Cr were 0.58, 0.65, 12.31, 38.70, and 87.30 mg/kg in soil and were 0.05, 0.005, 0.11, 0.07, and 0.34 mg/kg in rice, respectively. The bioconcentration factors (BCF) decreased with the order Cd > Hg > As > Cr > Pb. Non-carcinogenic risk in this study was evaluated using the method of the hazard quotient (HQ) and hazard index (HI). The mean HQ values for Cd, Hg, Pb, and Cr were all lower than the standard limit (1.0) for children and adults, except As with the mean HQ for children of 2.79. The mean HI values for children and adults were 4.22 and 1.42, which exceeded 1.0. The mean carcinogenic risk (CR) values of As and Pb for children and adults were higher than the upper limit of the acceptable range (1 × 10
−4
) established by the United States Environmental Protection Agency (USEPA). In a conclusion, the non-carcinogenic and carcinogenic risks induced by heavy metals for children were higher than that for adults. This study revealed that consumption of rice in study areas may pose potential non-carcinogenic and carcinogenic risks to humans, and As was the largest contributor.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The growth of bacteria will lead to water quality deterioration and equipment damage. Therefore, it is necessary to control the growth and reproduction of microorganisms in water treatment. A new ...type of magnetic recoverable CuZnO@Fe
3
O
4
@GO composites was prepared by ultrasonic method, and the composites were characterized and analyzed by SEM, TEM, XPS, and other methods. The optimum mass ratio of composites was determined by orthogonal experiment, and the antibacterial properties and mechanism of the composite were investigated by gram-positive bacteria
Staphylococcus aureus
and gram-negative bacteria
Escherichia coli
. Finally, the antibacterial properties of the composites in the effluent of the secondary sedimentation tank were researched. It was shown that the optimum mass ratio of the composites was GO:Fe
3
O
4
:CuZnO =1:2:3. When the dosage of composites was 180 mg L
-1
and the action time was 100 min, the antibacterial rate against
S. aureus
and
E. coli
reached more than 99.5%. The composites could destroy the cell structure of two kinds of bacteria, increase the content of active oxygen in bacteria cells, and enhance the leakage rate of protein by more than 9 times in 150 min, thereby causing the death of the bacteria. And the antibacterial rate of the composites in effluent of the secondary sedimentation tank could reach 99%, and the magnetic recovery rate could reach more than 98%. After 5 cycles of use, the antibacterial rate could still exceed 90%.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Software-Defined Networking (SDN). SDN enables network innovations with a centralized controller controlling the whole network through the control channel. Because the control channel delivers all ...network control traffic, its security and reliability are of great importance. For the first time in the literature, we propose the CrossPath attack that disrupts the SDN control channel by exploiting the shared links in paths of control traffic and data traffic. In this attack, crafted data traffic can implicitly disrupt the forwarding of control traffic in the shared links. As the data traffic does not enter the control channel, the attack is stealthy and cannot be easily perceived by the controller. In order to identify the target paths containing the shared links to attack, we develop a novel technique called adversarial path reconnaissance. Our experimental results show its feasibility and efficiency of identifying the target path. We systematically study the impacts of the attack on various network applications in a real SDN testbed. Experiments show the attack significantly degrades the performance of existing network applications and causes serious network anomalies, e.g., routing blackhole, flow table resetting, and even network-wide DoS. To defeat the CrossPath attack, we design a lightweight defense system named CrossGuard. Experiments demonstrate that it can effectively protect the control channel and quickly locate the attack flow with 98% accuracy while introducing a small overhead.
In oilfield produced water, polyacrylamide (PAM) is a kind of organic polymer, which may gradually degrade to produce a large number of acrylamide (AM) monomer, and cause great damage to the ...peripheral nervous system of human and animals. In order to improve its removal efficiency, rGO@Fe3O4/Cu2O@ZnO magnetic composites with strong hydrophobicity, high photocatalytic performance and recyclability was prepared. The degradation process of PAM on composites photocatalyst was studied by simulating the sunlight irradiation, and the magnetic recovery performance and photocatalytic stability of composite were explored. Finally, the photocatalytic degradation mechanism of rGO@Fe3O4/Cu2O@ZnO composite was discussed by free radical capture experiment. The results showed that the highest photocatalytic degradation efficiency was 97.3% when the mass ratio of GO@Fe3O4 and Cu2O@ZnO was 1:5, the dosage of rGO@Fe3O4/Cu2O@ZnO was 0.6 g L−1, pH value was 7 and the initial concentration of PAM was 100 g L−1. After four cycles, the magnetic recovery and degradation efficiency of PAM can still up to 91.3% and 81%, respectively, which both meet the needs of magnetic recovery and photocatalysis. In addition, according to the free radical capture experiment, the main active species was superoxide radical (·O2−). This work provides a strategy for designing magnetic composites with hydrophobic and high catalytic for photodegradation of organic pollutants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
The dietary supplement industry offers many oral cosmetics that purportedly assist in skin moisturization often with unclear evidence supporting efficacy and safety. To update the ...accessible proofs pertaining to the safety and effectiveness of oral dietary supplements to facilitate skin moisturizing via an all-around review and meta-analysis.
Methods
Three on-line databases Pubmed, Embase, and Cochrane Library (CENTRAL) were retrieved from January 2000 to November 2021. An overall 66 randomized controlled trials (RCTs) of skin care were recognized. Meta-analysis was performed for dietary supplements with four or more available research.
Results
Oral collagen or ceramide resulted in a statistically significant increase in skin hydration and a decrease in transepidermal water loss (TEWL) compared to placebo. No benefits regarding the improvement of skin conditions in terms of water content and TEWL were observed for lactic acid bacteria or Lactobacillus fermented foods. A statistically significant and positive effect on skin hydration was observed for both hyaluronan and procyanidin, with an unknown effect on TEWL due to insufficient RCTs. There was a non-significant improvement in the water content of stratum corneum for astaxanthin based on subgroup analyses. Among the dietary supplements trialed in ≤ 3 RCTs, the judgment regarding their effects on skin moisturizing was prevented by inconsistent conclusions as well as insufficient research. All food supplements were safe throughout the research (normally ≤ 24 weeks).
Conclusion
Oral dietary supplements, including collagen, ceramides, hyaluronan, and procyanidin, were proven to be effective for skin moisturization. At present, for skin moisturization, the proofs supporting the recommendation of other dietary supplements, such as lactic acid bacteria and astaxanthin, are insufficient.
Systematic Review Registration
http://www.crd.york.ac.uk/PROSPERO/
identifier CRD42021290818
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