Course teaching quality is a core content to measure the teaching level of a school, and teaching effect can be directly reflected from the state of students’ attendance. In order to improve students’ class status and promote class discipline, this paper proposes a detection method for students’ classroom behavior based on Faster R-CNN and transfer learning with multi-channel feature fusion. Firstly, images are obtained through the monitoring video of Zhejiang Agriculture and Forestry University and manually annotated, and data augmentation method is used to increase the scale of the images to establish the dataset of common students’ normal classroom behavior. Then, the Inception-ResNet-v2 network based on pre-training is applied for feature extraction, and the target detection framework adopts Faster R-CNN to realize the detection of normal learning, sleeping, lowering head and other student behaviors through transfer learning. Finally, through multi-channel feature fusion method, the shallow features of more detailed information are integrated in deep layers of rich semantic information, so as to gain the improved detection model of the students’ classroom performance. Experimental results show that the mean average precision of the model can reach 76.32%, which is 12.22 percentage points higher than original algorithm, and good detection effect can be achieved. This model has a high accuracy rate for students’ classroom behavior, which indicates that Faster R-CNN with multi-channel feature fusion has a good application prospect in students’ classroom behavior detection, and can provide a new reference for improving classroom teaching quality.

In order to make the tracker based kernel correlation filter to overcome occlusion and deformation, an adaptive block tracking algorithm is proposed by using kernel correlation filtering and multi-feature fusion. Firstly, adaptively divide it into blocks based on the size and height-width ratios of the target and extract the Histogram of oriented gradient (HOG) and color name (CN) features for each block; Secondly, represent the block with the fusion of HOG and CN, and use the kernel correlation filtering tracker to get the position with maximum response of each block; Thirdly, calculate the coordinate of candidate target through the coordinate geometric relationship between each block and the original target; Moreover, the final target position is obtained by weighted average of the coordinates of all coordinates. Finally, the peak to side lobe ratio(PSR) of a blocks response curve as well as the distance between its response position and the final target position are used to judge its validity, and the valid blocks are adaptively updated. The experimental results on several data set show that the proposed method performs well on occlusion and deformation, and its comprehensive performance is better than other methods.

To effectively improve the capital and land utilization efficiency of 110 kV GIS substation in Anhui area, and guide the planning and management of the substation in the early and later stages. In this paper, the life cycle costs (LCC) of 110 kV GIS substation with 12 design schemes are estimated, the design planning of substation is considered from the perspective of economic cost, and fuzzy theory is introduced into the estimation process to improve the accuracy and reliability of the estimation model. The estimated results show that the estimated costs of the 110-A1-2 and 110-A1-4 design schemes are the lowest, which are suitable for Anhui area. This result has certain reference significance for operation management and planning of 110 kV GIS substation of city power grid in Anhui area.

Rolling motion dominates the lateral stability of the aircraft. In order to study the random response of the delta wing’s rolling motion under random excitation, external and parametric excitations are added to a more complex rolling model. The approximate probability density of the system is obtained by the dissipative energy balance method, the amplitude envelope random average method and the energy envelope random average method. The accuracy of the three methods is compared by numerical simulations.

Let G be a finite group. A subgroup H of G is called nearly S-permutable in G if for every prime p with gcd (公式 and for every subgroup K of G containing H the normalizer N_K(H) contains some Sylow p-subgroup of K. A subgroup H of G is said to be 公式permutable subgroup of G if there exists a normal subgroup T of G such that HTG, π(G/T)π(H) and H∩T is nearly S-permutable subgroup of G. This article investigates the structure of G under the assumption that subgroups of prime power order are NS^*-permutable subgroups of G. Some recent results are generalized.

This paper mainly studies the influence of C-normality of self-centralizing subgroups and the number of conjugate classes of self-centralizing subgroups on the structure of finite groups. Some sufficient conditions for finite groups to be supersolvable groups or solvable groups are obtained and some results of the classification of finite groups certain some conditions are also obtained.

In this paper, the research on the risk measurement of the 5G plate is carried out. The results show that the logarithm of the yield series has a bias, a sharp peak, a non-normal feature, and an ARCH effect. The GJRGARCH(1,1) model with different distributions is fitted. It is found that there is no leverage effect in the 5G plate; the VaR calculation is performed under different distributions using the GJRGARCH(1,1) model, and the GJRGARCH(1,1) model based on the skew-t distribution can be better measured by the Kupiec test.

This paper establishes a class of ecological model of three species with predator-competition-cooperative hybrid interaction. Firstly, the positivity and boundedness of the solution of the system are discussed by introducing auxiliary system and differential comparison principle. Next, the sufficient conditions of globally asymptotically stable positive equilibrium are abtained by constructing suitable Lyapunov functions and some analytical skills. Finally, numerical simulations are conducted to verify the theoretical results.

In order to provide experimental basis for further research on endophytic fungi from Sophora tonkinensis, the chemical compounds of the metabolites of GDGJ-368 had been studied. Seven compounds had been isolated from the metabolites through column chromatography, and their structures were elucidated by NMR spectroscopy. The results showed that the structures of the compounds were 5-carboxylmellein (1), diaporthein B (2), piliformic (3), cytochalasin C (4), cytochalasin D (5), (22E)-ergosta-6, 22-diene-3β, 5β, 8α-triol (6) and (22E, 24R) -5α, 8α-epidioxy-24-methyl-cholesta-6, 22-diene-3β-ol (7). Compound 2 was isolated from Xylaria sp. for the first time, and compounds 4 and 5 were isolated from the fungi which were isolated from the plants of the genus Sophora firstly.

Twenty compounds of Caulis Alsophilae were isolated and purified by silica gel, macroporous resin adsorption, MCI GEL CHP-20P, Flash C18 and Sephadex LH-20P chromatography. Their structures were identified as stigmasterol (1), palmiticacid (2), n-tridecane (3), lupeol (4), p-hydroxycinnamic acid (5), glycerolmon-opalmitate (6), 24(R)-24-ethyl-6β-hydroxyl-4-cholestenol-3-ketone (7), 24(R)-24-ethyl-5α- cholestane-3β,5α,6β-triol (8), ferulicacid (9), emodin (10), vitexin (11), apigenin (12), dihydrogenapigenin (13), 3, 4-dihydroxy benzeneacrylic-acid (14), heptadec-(9Z)-enoic acid (15), rutin (16), inoseavin A (17), salvinisideⅡ (18), 4-O-β-D-glucopyranosyl-p-coumaric acid (19) and isoquercitrin (20). Compounds 1~5, compounds 7~10, compound 13, compounds 15~18 and compound 20 were isolated from Caulis Alsophilae for the first time.

In this paper, a kind of PAN-based weak alkaline ion exchange fiber was synthesized and was used as adsorbent for Zn²⁺. The effects of pH, temperature, adsorption time and concentration of Zn²⁺ solution on the adsorption performance of modified fibers were investigated. The optimal concentration and volume of hydrochloric acid for desorption the fiber were discussed. The results showed that the adsorption performance of the modified fiber was better as the pH increases within the range of pH＝2~6; The adsorption reached a dynamic equilibrium after 60 min of reaction at 303 K, and the maximum saturated adsorption amount was 155.33 mg/g. The temperature had little effect on the adsorption performance of the fiber. The regeneration of the fiber worked best with 5 mL of 1.2 mol/L hydrochloric acid solution, and the modified fiber had good chemical stability. The process of adsorbing Zn²⁺ by modified fiber conformed to the Langmuir isotherm adsorption model and belonged to monolayer adsorption.

In order to further reveal the influence of the structure and function of typical primitive forest ecosystems in the Qinghai-Tibet Plateau, this article took the Tibetan native gymnosperm plant Picea likiangensis var. linzhiensis Cheng et L.K. Fu as the main subject of investigation. The field survey method was used to investigate the growth of trees, shrubs, and herbs in the spruce forest by setting up plots. The relationship between the spatial structure of the original P. likiangensis var. linzhiensis and the environment was analyzed and studied. The point pattern analysis shows that: in the small-scale range, P. likiangensis var. linzhiensis tends to be distributed in clusters; in the large-scale range, under the influence of environmental heterogeneity, P. likiangensis var. linzhiensis presents a random distribution. Among them, the small-diameter trees show as cluster distribution. Spatial structure research shows that the original P. likiangensis var. linzhiensis in Tibet has obvious layering phenomena such as tree layer, shrub layer, herb layer and moss layer. P. likiangensis var. linzhiensis is the absolutely dominant species in the community, with an individual number of more than 66%. The forest gap enhances the environmental heterogeneity of P. likiangensis var. linzhiensis. The spatial pattern of P. likiangensis var. linzhiensis is closely related to soil physical and chemical properties and topography. The soil physical and chemical properties in different regions also determine the distribution characteristics of the community spatial pattern.

In order to explore the diversity characteristics of bryophytes in typical metaphase developed tiankeng, a field survey was conducted in Chuandong Tiankeng, Guangxi. The results showed that the species diversity of bryophytes were rich, and the dominant groups were obvious. There were 96 species of bryophytes (including subspecies and varieties), belonging to 57 genera, 33 families. Bryophytes were rich and complex in species composition. Unigeneric family and unispecific genus were rich, including 14 families and 40 genera, which accounted for 42.42% and 70.18% of the whole families and genera respectively. The life forms were divided into 8 types, mainly Wefts and Turfs, which had relatively high diversity of life forms. From the upper to the bottom of the Tiankeng, the distribution pattern of life type was from Turfs with drought resistance to wet Fans. The bryophytes had diversity of ecological types, which was divided into 4 types according to the growth substrate, and bryophytes growing on the surfaces of soil and rocks were dominant. On the height gradient, the species richness of bryophytes changed obviously, presenting a decreasing trend of middle > bottom > upper, which was closely related to the heterogeneity of Tiankeng habitat. As a refugia for native plants in Karst areas, the Chuandong Tiankeng also had a great potential to preserve the diversity of non-vascular higher plants (bryophytes). Therefore, it is suggested that such metaphase developed Tiankengs’ ecological system with special negative topography should be protected.

The polymorphisms of TCP-1-eta gene in GIFT tilapia samples were detected by using cold stress test and PCR-SSCP technique and the correlation with cold tolerance capability of tilapia was analyzed by least square method in this study. The results showed that the primers of TCP1-1, TCP1-2, TCP1-3 and TCP1-4 were designed according to the sequence of TCP-1-eta gene. The electrophoresis patterns of TCP1-4 primers showed band polymorphism in samples with final constant temperatures of 8 ℃, 12 ℃ and 14 ℃. There was a significant correlation between gene polymorphism and cold tolerance traits at 12 ℃ and 14 ℃ (P<0.05). Therefore, it is inferred that TCP-1-eta gene were potential cold-resistant genes of tilapia.

Soil is an important part of the environment. Excessive heavy metals entering the soil cycle will not only lead to the decline of soil quality, soil productivity and food security, but also affect human health. Based on 76 sampling sites in Conghua District of Guangzhou city, the risk assessment of five heavy metals Cd, Hg, As, Pb and Cr in cultivated soil was carried out by using Hakanson potential ecological risk index and health risk assessment method. The results showed that the content of each heavy metal was in the order as follow: Cr(78.690±38.160 mg·kg^-1), Pb(54.300±18.120 mg·kg^-1), As(10.280±7.230mg·kg^-1), Hg(0.163±0.050 mg·kg^-1), Cd(0.160±0.050mg·kg^-1). The contribution rate to the potential ecological risk of soil is as follow: Cd,Hg,As,Pb,and Cr. The potential ecological risk indexes of heavy metals Cd and Hg were mainly at medium and high ecological risk levels, while the other three heavy metals were all at slight ecological risk levels. The comprehensive potential ecological risk index was mainly at medium ecological risk level. The non-carcinogenic risk mainly comes from heavy metal Cr, among which the total risk of multi-pathway non-carcinogenic in children was about 7 times that of adults. The total carcinogenic risk of heavy metals As and Cd is 1.997×10^-3, and there was a carcinogenic risk. The results showed that there was a certain pollution risk of heavy metals in the cultivated soil of Conghua District, and the corresponding prevention and control measures should be strengthened in the actual production and life.