Several equivalent conditions for the boundedness and compactness of the difference Cφ-Cψ:Zα→ Bβ were presented for α>1,β>0.As a nontrivial extension,Taylor series and Raabe discriminant are used to establish the complete characteri-zations for bounded or compact Cφ-Cψ:Zα,0→B0β.
In order to explore the body characteristics of Dongxiang and its changes in the past 30 years,the body items of 840 Dongxiang adults(338 males,502 females)were measured in Guanghe County and Dongxiang County of Linxia Hui Autono-mous Prefecture of Gansu Province,and the body indexes were calculated.The results were as follows:①The gender differ-ences of body items and body indexes of Dongxiang had statistical significance.Both male and female of Dongxiang belonged to middle stature type,broad distance between iliac crests type,broad shoulder breadth type and mesatiskelic type,with long trunk type for male and middle trunk for female.②Compared with 30 years ago,the body mass,shoulder breadth,crestailiaca breadth and upper extremity length of male and female of Dongxiang increased significantly,and the thigh length of female in-creased significantly.③Compared with other ethnic groups in Northwest China,Dongxiang had larger body mass and crestail-iaca breadth,and the body characteristics of Dongxiang were closest to Hui and Baoan.
In order to learn the current situation of zooplankton community structure in the sea area near Rushan Bay,based on the investigation data of zooplankton in this area in March(spring)and November(Autumn)in 2020,the community structure characteristics of zooplankton were analyzed.The results showed that:①22 species and 6 taxa of zooplankton were found in the two seasons,including 13 species and 4 taxa in spring,and 17 species and 6 taxa in autumn;②In spring,the average abun-dance of zooplankton was 110.1 ind./m3,the average biomass(wetweight)was206.7mg/m3,andtheaverage Shannon-Wiener index,Margalef's species richness diversity and Pielou's evenness index were 3.09,1.97,0.80,respectively;In autumn,the average abundance of zooplankton was 137.9 ind./m3,the average biomass(wet weight)was 91.3 mg/m3,and the average Shannon Wiener index,Margalef's species richness diversity and Pielou's evenness index were 2.06,1.59,0.57,respec-tively;③In spring,the dominant species were Calanus sinicus,Eurytemora pacifica,Sagitta crassa,Paracalanus parvus,Acar-tia bifilosa,Centropages abdominali,Paracalanus crassirostris,Oithona similis,Corycaeus affinis,Copepodite Nauplius larva.While in autumn,the dominant species were Paracalanus parvus,Oithona similis,Aidanosagitta crassa,Oikopleura dioica,Bivalves larva;④Cluster analysis showed that the zooplankton in the investigation area could be divided into two groups.
In order to improve the carotenoid production of Rhodotorula,the carotenoid contents of eight Rhodotorula strains isolated from aquaculture environment were evaluated,and the strain Rhodosporidium paludigenum CN7 with the strongest ability of producing carotenoid was screened out.Single factor experiment was employed to optimize the carotenoid synthesis conditions of strain CN7 by adding different content of tomato homogenate,carrot juice,sodium citrate and ethanol,respective-ly.The results showed that the addition of the above four substances to the culture medium could significantly improve the carotenoid synthesis ability of strain CN7,but different substances had different effects on the carotenoid synthesis.The order of influence was carrot juice＞ethanol＞sodium citrate＞tomato homogenate.When 80 mL/L carrot juice,or 20 mL/L tomato homo-genate,or 6.0 g/L sodium citrate,or 1.5 mL/L ethanol was added to the culture,the carotenoid contents of strain CN7 were 342.82,280.00,255.62,239.19 μg/g,respectively,which were 101.5%,64.6%,50.3%,40.6%higher than the initial value 170.11 μg/g,respectively.The results suggested that carotenoid content of strain CN7 was increased greatly by carrot juice,so the appropriate amount of carrot juice should be added to the culture medium to get higher carotenoid yield.
The Retinex low-illumination image enhancement algorithm based on HSV space is proposed for the problems of low luminance,uneven illumination,poor contrast and loss of detail information in low-illumination images.Firstly,the low-illumi-nation image is transformed into HSV space.And then the improved Retinex algorithm and the luminance enhancement algo-rithm based on the combination of adaptive Gamma correction and CLAHE algorithm in HSV space for the luminance channel are used to realize the luminance enhancement of the low-illumination image.Next,the saturation component image is enhanced by bilateral filtering and using linear stretching.Finally,the enhanced image is reconverted back to RGB format for display,and the automatic white balance technique is used to restore the original color of the image object.The experimental results show that the proposed algorithm improves the quality of low-illumination images effectively,and achieves better visual effects.PSNR,SSIM and information entropy of the algorithm are better than those of other algorithms.
