期刊文献+
共找到286篇文章
< 1 2 15 >
每页显示 20 50 100
Molecular cloning and expression analysis of interleukin - 1β from Japanese sea perch(Lateolabrax japonicus ) 被引量:1
1
作者 QIU Lihua SONG Linsheng +2 位作者 WU Longtao CAI Zhonghua JIANG Shigui 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第1期127-136,共10页
The technology of homology cloning and anchored PCR was used to clone the IL-1β gene from the Japanese sea perch (Lateolabrax iaponicus). The full-length cDNA of sea perch IL-1β was 1 310 bp, including a 5' untra... The technology of homology cloning and anchored PCR was used to clone the IL-1β gene from the Japanese sea perch (Lateolabrax iaponicus). The full-length cDNA of sea perch IL-1β was 1 310 bp, including a 5' untranslated regiop (UTR) of 136 bp, a 3' UTR ot 430 bp, and an ORF of 774 bp encoding a polypeptide of 258 amino acids with an estimated molecular mass of 29.31 kDa. The searches for nucleotides and protein sequence similarities with the BLAST analysis indicated that the deduced amino acid sequence of sea perch IL-1β was homological to the IL-1β in other fish species and even the mammalian. Conserved signature sequences of the IL-1β gene family were found in the sea perch IL-1β deduced amino acid sequence. Temporal expressions of the IL-1β gene in LPS or iridovirus challenged group and in control group were measured by the semi-quantitative RT-PCR. The mRNA transcripts of IL-1β could be detected in head-kidney, spleen, liver, gill and heart of the healthy individuals, and the expression level of IL-1β in head-kidney, spleen and gill was higher than that in liver and heart, but it was hard to be detected in the brain. After being stimulated by the LPS or iridovirus, the IL-1β expression in most of examined tissues was up-regulated, and also could be detected in the brain. These results indicated that the expression of sea perch IL-1β was constitutive and could be up-regulated by immune effector stimulation. Therefore the sea perch IL-1β could play a critical role in the host-pathogen interaction. 展开更多
关键词 Japanese sea perch INTERLEUKIN-1Β gene cloning CDNA mRNA expression
下载PDF
Pond Substrate Type Affects Yellow Perch Fingerling Size at Harvest 被引量:1
2
作者 Matthew J. Ward 《Open Journal of Animal Sciences》 2021年第1期31-36,共6页
Fish size and harvest density generally exhibit a negative relationship in pond culture, but the influence that pond substrate type can have on this relationship is not well understood. To evaluate the influence of po... Fish size and harvest density generally exhibit a negative relationship in pond culture, but the influence that pond substrate type can have on this relationship is not well understood. To evaluate the influence of pond substrate type on yellow perch (<i></span><i><span style="font-family:Verdana;">Perca flavescens</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">), harvest density (number/hectare) was linearly regressed against individual fingerling size (grams) for lined (n = 48) and earthen (n = 40) substrate ponds that were treated similarly in terms of organic fertilizer use and the number of days in the pond over 12 culture seasons at Blue Dog Lake State Hatchery, South Dakota, USA. Harvest density explained 45 and 39% of the variation in yellow perch size in lined and earthen-substrate ponds (all <i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> < 0.01). Comparison of regression lines indicated that fingerling size decreased as harvest density increased at a similar rate in both pond types (slope comparison, <i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> = 0.62);however, fingerling size was significantly larger in lined ponds regardless of density that varied from near 0 to 700,000 per hectare (y-intercept comparison, <i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> < 0.01). At the same harvest density, lined ponds will tend to produce larger yellow perch fingerlings compared to earthen ponds when similar organic fertilizers are used. 展开更多
关键词 Yellow perch Pond Culture Pond-Substrate Type
下载PDF
Shape reconstructions and morphing kinematics of an eagle during perching manoeuvres
3
作者 唐迪 刘大伟 +3 位作者 朱海 黄喜鹏 范忠勇 雷鸣霞 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第2期327-336,共10页
The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-s... The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry.A three-jointed arm model is proposed to associate with the 3D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions. 展开更多
关键词 large BIRD of PREY shape reconstruction MORPHING KINEMATIC perchING
下载PDF
Perch Associated Expression of Phenotypic Plasticity in Limb Development and Sprint Speed in Agamid Lizard Calotes versicolor: A Laboratory Study
4
作者 Veena H.F.AMMANNA Srinivas K.SAIDAPUR Bhagyashri A.SHANBHAG 《Asian Herpetological Research》 SCIE CSCD 2018年第3期175-181,共7页
New born hatchlings of Calotes versicolor were reared in terrarium having narrow or wide perches for a period of 4-month and their snout vent length(SVL), tail, fore and hindlimb lengths were measured at monthly int... New born hatchlings of Calotes versicolor were reared in terrarium having narrow or wide perches for a period of 4-month and their snout vent length(SVL), tail, fore and hindlimb lengths were measured at monthly intervals. Limb postures(closer to the body or spread away from the body) were also recorded. The sprint speed was recorded in two and four-month old lizards on a 1 m long race track providing 45° or 60° slope. In both the groups, SVL and tail lengths were comparable but the limb lengths and their growth rates were significantly greater in lizards of wider perch group. The lizards reared with narrow perches positioned their limbs closer to the body; while those reared on wider perches spread their limbs away from their body. Further, the latter exhibited significantly higher sprint speed regardless of the slope of the race track over those of narrow perch group. Sprint speeds of lizards in both groups were correlated with the limb sizes. The study showed that the lizards reared on narrow or wide perches exhibited divergent adaptive responses(phenotypic plasticity) by developing longer or shorter limbs and corresponding changes in their sprint speeds. These findings support the idea that availability of perch structure during early development evokes adaptive plasticity in the limb development and associated locomotory performance in arboreal lizards like C. versicolor. 展开更多
关键词 behavior Calotes HATCHLINGS LIMB LIZARD perch PLASTICITY sprint speed
下载PDF
Influence of Amino Acid Supplementations in Juvenile Yellow Perch Fed Plant Protein Combinations
5
作者 Aaron J. Von Eschen Michael L. Brown Kurt Rosentrater 《Open Journal of Animal Sciences》 2019年第2期183-195,共13页
Distillers dried grains with solubles (DDGS) in combination with soy protein concentrate (SPC) with and without an essential amino acid (EAA) complex were assessed as protein alternatives in juvenile Yellow Perch Perc... Distillers dried grains with solubles (DDGS) in combination with soy protein concentrate (SPC) with and without an essential amino acid (EAA) complex were assessed as protein alternatives in juvenile Yellow Perch Perca flavescens diets. Diets contained 5% FM, 40% SPC, and 20% or 40% DDGS each with or without EAA. No mortalities or health assessment differences were observed during the trial and all fish readily accepted the experimental diets. Diets supplemented with EAA produced greater weight gain, improved feed conversion, and apparent protein digestibility. Performance was consistently improved for fish fed diets containing amino acid supplements. Based on these results, Yellow Perch are able to utilize high levels of the plant proteins, accompanied with EAAs, as a FM replacer. 展开更多
关键词 Yellow perch Fish Nutrition Distillers DRIED Grains with Solubles SOY Protein CONCENTRATE Amino Acids
下载PDF
Geoelectrical survey over perched aquifers in the northern part of Upper Sakarya River Basin,Türkiye
6
作者 Can Ertekin Emin U Ulugergerli 《Journal of Groundwater Science and Engineering》 2022年第4期335-352,共18页
In this study,a groundwater exploration survey was conducted using the DC Resistivity(DCR)method in a hydrogeological setting containing a perched aquifer.DCR data were gathered and an electrical tomography section wa... In this study,a groundwater exploration survey was conducted using the DC Resistivity(DCR)method in a hydrogeological setting containing a perched aquifer.DCR data were gathered and an electrical tomography section was recovered using conventional four-electrode instruments with a Schlumberger array and a two-dimensional(2D)inversion scheme.The proposed scheme was tested over a synthetic threedimensional(3D)subsurface model before deploying it in a field situation.The proposed method indicated that gathering data with simple four-electrode instruments at stations along a line and 2D inversion of datasets at multiple stations can recover depth intervals of the studied aquifer in the hydrogeological setting even if it has a 3D structure.In this study,2D inversion of parallel profiles formed a pseudo-3D volume of the subsurface resistivity structures and mapped out multiple resistive(>25 ohm·m)bodies at shallow(between 50-100 m)and deep sections(>150 m).In general,the proposed method is convenient to encounter geological units that have limited vertical and spatial extensions in any direction and presents resistivity contrast from groundwater-bearing geologic materials. 展开更多
关键词 GROUNDWATER perched Aquifer DC Resistivity INVERSION Sakarya River Türkiye
下载PDF
Comparison of Nutritional Quality in Fish Maw Product of Croaker Protonibea diacanthus and Perch Lates niloticus 被引量:8
7
作者 WEN Jing ZENG Ling +1 位作者 Chen Ziming XU Youhou 《Journal of Ocean University of China》 SCIE CAS 2016年第4期726-730,共5页
Fish maw(the dried swimbladders of fish) is ranked in the list of the four sea treasures in Chinese cuisine. Fish maw is mainly produced from croaker, which is the most highly priced. However, some of the fish maw bei... Fish maw(the dried swimbladders of fish) is ranked in the list of the four sea treasures in Chinese cuisine. Fish maw is mainly produced from croaker, which is the most highly priced. However, some of the fish maw being sold as croaker maw are in fact not from croaker, but from the Nile perch Lates niloticus. The present work determined and compared the proximate composition, amino acid and fatty acid composition of croaker Protonibea diacanthus maw and perch L. niloticus maw. The results indicated that both maws were high protein sources and low in fat content. The dominant amino acids in both maws were glycine, proline, glutamic acid, alanine and arginine. These amino acids constituted 66.2% and 66.4% of the total amino acids in P. diacanthus and L. niloticus, respectively. The ratio of FAA: TAA(functional amino acids: total amino acids) in both maws were 0.69. This is a good explanation for why fish maws have been widely utilized as a traditional tonic and remedy in Asia. Except valine and histidine, all the essential amino acid contents in P. diacanthus were higher than in L. niloticus. Moreover, croaker P. diacanthus maw contained more AA and DHA than perch L. niloticus maw, showing a higher ratio of n-3 / n-6, which is more desirable. 展开更多
关键词 fish maw proximate composition amino acids fatty acids
下载PDF
Effect of Perched Water Tables on Aluminosilicate Stability and Soil Genesis 被引量:4
8
作者 ZHANG MIN , GONG ZITONG and A. D. KARATHANASIS College of Resources and Environment, Shandong Agricultural University, Tai’an 271018 (China) Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) College of Agriculture, U 《Pedosphere》 SCIE CAS CSCD 2000年第3期247-256,共10页
The mineral stability and solute activities of soil solution extracted from selected horizons of seven studied pedons of Alfisols in Kentucky, USA, and the relationship between distribution of iron-manganese concretio... The mineral stability and solute activities of soil solution extracted from selected horizons of seven studied pedons of Alfisols in Kentucky, USA, and the relationship between distribution of iron-manganese concretions and the restrictive layers were investigated. The results showed that the genesis and development of these soils and mineral weathering trends were strongly influenced by the depth of bedrock and the presence of perched water tables at lithic (limestone) interfaces due to the dissolution and buffering effect of limestone bedrock. The extractable Mg/Ca ratio as depth function and soil depth above bedrock could be used as indices of weathering and degree of soil development. Maximum iron-manganese concretion accumulation was found to occur in the horizon overlying clay horizon (>40% clay) with a sharp increase in clay content (>10%), which suggested that zones of Fe-Mn concretion accumulation in soils of the Inner Bluegrass Region appeared to be a sensitive genetic indicator of argillic horizons with restrictive permeability. 展开更多
关键词 土壤 基岩 石灰石 铝硅酸盐 矿物稳定性 成因 美国
下载PDF
Persistence of malachite green and leucomalachite green in perch (Lateolabrax japonicus) 被引量:1
9
作者 谭志军 邢丽红 +4 位作者 郭萌萌 王洪艳 江艳华 李兆新 翟毓秀 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第3期647-655,共9页
The persistence of malachite green (MG), and its metabolite leucomalachite green (LMG), in fish tissues is still unclear, leading to many trade disputes. In this research, we established and evaluated an HPLC method t... The persistence of malachite green (MG), and its metabolite leucomalachite green (LMG), in fish tissues is still unclear, leading to many trade disputes. In this research, we established and evaluated an HPLC method that could detect MG and LMG simultaneously, and then investigated the persistence of these two toxins in the tissues of juvenile perch (Lateolabrax japonicus) post sub-chronic MG exposure at 1.0 mg/L. Exposure lasted for 2 h everyday and was repeated six times. The perch were then placed in MG-free seawater for 100 d to eliminate the toxins. Results show that MG accumulated in the tissues, including the gills, liver, muscle, blood and viscera, and then was metabolized rapidly to LMG. The concentrations of these two toxins increased significantly with the accumulation process. In general, the highest concentrations of MG and LMG in all tissue exceeded 1 000 μg/kg, except for MG in the muscle. The order of accumulation levels (highest to lowest) of MG was gill>blood>liver>viscera>muscle, while that of LMG was liver>blood>gill>viscera>muscle. High levels of MG or LMG could persist for several hours but decreased rapidly during the elimination process. The concentration of LMG was much higher than that of MG during the experiment, especially in the gill, liver and blood. Therefore, the three tissues play important roles in toxin accumulation, biotransformation, and elimination. Although the MG and LMG concentrations in muscle were much lower than in other tissues, the content still exceeded the European minimum required performance limit (MRPL), even after 2 400 h (100 d) of elimination. This demonstrates that it is extremely difficult to eliminate MG and LMG from tissues of perch, and therefore use of these toxins is of concern to public health. 展开更多
关键词 无色孔雀石绿 鲈鱼 毒素积累 血液浓度 高效液相色谱法 代谢产物 鱼组织 轻机枪
下载PDF
Dietary host-associated Bacillus subtilis supplementation improves intestinal microbiota,health and disease resistance in Chinese perch(Siniperca chuatsi)
10
作者 Zhehui Ji Chuanzhong Zhu +7 位作者 Xinyang Zhu Sainan Ban Lijuan Yu Juan Tian Lixue Dong Hua Wen Xing Lu Ming Jiang 《Animal Nutrition》 SCIE CAS CSCD 2023年第2期197-205,共9页
The purpose of this study was to evaluate the potential of a host-associated Bacillus subtilis 1-C-7 as a probiotic for Chinese perch(Siniperca chuatsi).Four test diets were formulated to contain graded levels of B.su... The purpose of this study was to evaluate the potential of a host-associated Bacillus subtilis 1-C-7 as a probiotic for Chinese perch(Siniperca chuatsi).Four test diets were formulated to contain graded levels of B.subtilis 1-C-7 at 0(CY),0.85×10^(8)(Y1),0.95×10^(9)(Y2)and 0.91×10^(10)(Y3)CFU/kg diet.The test fish with initial weight 30.0±1.2 g were fed the 4 test diets with 3 replicates in an indoor water-flow aquaculture system with 12 net cages(40 fish/cage)for 10 wk.At the conclusion of the feeding trial,the probiotic effects of B.subtilis on Chinese perch were analyzed based on growth performance,serum biochemical indices,histologic morphology of liver and gut,gut microbiota and the resistance to Aero-monas hydrophila.The results showed that the percentage of weight gain had no significant change in the Y1 and Y2 groups(P>0.05)but decreased in the Y3 group compared to that in the CY group(P<0.05).The fish in the Y3 group displayed the highest activity of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)among these 4 groups(P<0.05).The fish in the CY group had the highest value of malondialdehyde in the liver(P<0.05)and showed severe nuclear migration and vacuolization of hepatocytes.The morphology indicated that all test fish had poor intestinal health.However,the fish in the Y1 group had a relatively normal intestinal histologic structure.The mid gut microbial diversity analysis showed that dietary B.subtilis supplementation increased the abundance of probiotics such as Tenericutes and Bacteroides,whereas it reduced the abundance of pernicious bacteria such as Proteobacteria,Actinobacteria,Thermophilia and Spirochaetes.The challenge test showed that dietary B.subtilis supplementation increased the resistance to A.hydrophila in Chinese perch.In conclusion,dietary supplementation of 0.85×10^(8)CFU/kg B.subtilis 1-C-7 could improve the intestinal microbiota,intestinal health and disease resistance in Chinese perch,but more or excessive supple-mentation could reduce growth performance and have negative effects on health. 展开更多
关键词 Bacillus subtilis Intestinal microbiota Intestinal health Disease resistance Chinese perch(Siniperca chuatsi)
原文传递
Into Africa via docked India: a fossil climbing perch from the Oligocene of Tibet helps solve the anabantid biogeographical puzzle 被引量:6
11
作者 Feixiang Wu Dekui He +1 位作者 Gengyu Fang Tao Deng 《Science Bulletin》 SCIE EI CAS CSCD 2019年第7期455-463,共9页
The northward drift of the Indian Plate and its collision with Eurasia have profoundly impacted the evolutionary history of the terrestrial organisms, especially the ones along the Indian Ocean rim. Climbing perches(A... The northward drift of the Indian Plate and its collision with Eurasia have profoundly impacted the evolutionary history of the terrestrial organisms, especially the ones along the Indian Ocean rim. Climbing perches(Anabantidae) are primary freshwater fishes showing a disjunct south Asian-African distribution,but with an elusive paleobiogeographic history due to the lack of fossil evidence. Here, based on an updated time-calibrated anabantiform phylogeny integrating a number of relevant fossils, the divergence between Asian and African climbing perches is estimated to have occurred in the middle Eocene(ca.40 Ma, Ma: million years ago), a time when India had already joined with Eurasia. The key fossil lineage is ?Eoanabas, the oldest anabantid known so far, from the upper Oligocene of the Tibetan Plateau.Ancestral range reconstructions suggest a Southeast Asian origin in the early Eocene(ca. 48 Ma) and subsequent dispersals to Tibet and then India for this group. Thereby we propose their westbound dispersal to Africa via the biotic bridge between India and Africa. If so, climbing perch precursors had probably followed the paleobiogeographical route of snakehead fishes, which have a slightly older divergence between African and Asian taxa. As such, our study echoes some recent molecular analyses in rejecting the previously held ‘‘Gondwana continental drift vicariance" or late Mesozoic dispersal scenarios for the climbing perches, but provides a unique biogeographical model to highlight the role of the preuplift Tibet and the docked India in shaping the disjunct distribution of some air-breathing freshwater fishes around the Indian Ocean. 展开更多
关键词 CLIMBING perchES Asian-African DISJUNCT distribution Biogeography Indian subcontinent TIBET
原文传递
鲈鱼尾水中微生物多样性研究
12
作者 许长峰 王海丽 +1 位作者 唐伟斌 宋锰煊 《现代畜牧科技》 2024年第5期27-30,共4页
该文采用高通量测序法分析鲈鱼尾水中微生物的多样性,结果表明鲈鱼尾水的优势细菌门为变形菌门(Proteobacteria)、优势真菌门为子囊菌门(Ascomycota)。主要的菌属有hgcI_clades属、不整孢菌属(Plectosphaerella)、氢噬胞菌属(Hydrogenop... 该文采用高通量测序法分析鲈鱼尾水中微生物的多样性,结果表明鲈鱼尾水的优势细菌门为变形菌门(Proteobacteria)、优势真菌门为子囊菌门(Ascomycota)。主要的菌属有hgcI_clades属、不整孢菌属(Plectosphaerella)、氢噬胞菌属(Hydrogenophaga)、黄杆菌属(Flavobacterium)、镰刀菌属(Fusarium)、Aphelidium属、虫草属(Cordyceps)、中国鳞伞属(Pholiota)。养殖场尾水的物种最多,群落丰富度最好,丰度均匀度最高,实验室尾水物种最低,群落丰富度最少,丰度的均匀度最差,不同环境不同浑浊度鲈鱼尾水微生物多样性具有显著差异。 展开更多
关键词 鲈鱼 尾水 微生物 多样性 结构 组成
下载PDF
Design and Experiment of a Deformable Bird-inspired UAV Perching Mechanism 被引量:1
13
作者 Long Bai Hao Wang +4 位作者 Xiaohong Chen Jia Zheng Liming Xin Yupeng Deng Yuanxi Sun 《Journal of Bionic Engineering》 SCIE EI CSCD 2021年第6期1304-1316,共13页
Energy consumption and acoustic noise can be significantly reduced through perching in the sustained flights of small Unmanned Aerial Vehicles(UAVs).However,the existing flying perching robots lack good adaptability o... Energy consumption and acoustic noise can be significantly reduced through perching in the sustained flights of small Unmanned Aerial Vehicles(UAVs).However,the existing flying perching robots lack good adaptability or loading capacity in unstructured environments.Aiming at solving these problems,a deformable UAV perching mechanism with strong adaptability and high loading capacity,which is inspired by the structure and movements of birds'feet,is presented in this paper.Three elastic toes,an inverted crank slider mechanism used to realize the opening and closing movements,and a gear mechanism used to deform between two configurations are included in this mechanism.With experiments on its performance towards different objects,Results show that it can perch on various objects reliably,and its payload is more than 15 times its weight.By integrating it with a quadcopter,it can perch on different types of targets in outdoor environments,such as tree branches,cables,eaves,and spherical lamps.In addition,the energy consumption of the UAV perching system when perching on objects can be reduced to 0.015 times that of hovering. 展开更多
关键词 perching mechanism Bionic design UAV Flying robot Grasper
原文传递
Chronic exposure to high-density polyethylene microplastic through feeding alters the nutrient metabolism of juvenile yellow perch (Perca flavescens) 被引量:1
14
作者 Xing Lu Dong-Fang Deng +10 位作者 Fei Huang Fabio Casu Emma Kraco Ryan J.Newton Merry Zohn Swee J.Teh Aaron M.Watson Brian Shepherd Ying Ma Mahmound A.O.Dawood Lorena M.Rios Mendoza 《Animal Nutrition》 SCIE CSCD 2022年第2期143-158,共16页
Microplastics are emergent contaminants threatening aquatic organisms including aquacultured fish.This study investigated the effects of high-density polyethylene(HDPE,100 to 125 mm)on yellow perch(Perca flavescens)ba... Microplastics are emergent contaminants threatening aquatic organisms including aquacultured fish.This study investigated the effects of high-density polyethylene(HDPE,100 to 125 mm)on yellow perch(Perca flavescens)based on integrative evaluation including growth performance,nutritional status,nutrient metabolism,fish health,and gut microbial community.Five test diets(0,1,2,4,or 8 g HDPE/100 g diet)containing 41%protein and 10.5%lipid were fed to juvenile perch(average body weight,25.9±0.2 g;n=15)at a feeding rate of 1.5%to 2.0%body weight daily.The feeding trial was conducted in a flow-through water system for 9 wk with 3 tanks per treatment and 15 yellow perch per tank.No mortality or HDPE accumulation in the fish was found in any treatments.Weight gain and condition factor of fish were not significantly impacted by HDPE(P>0.05).Compared to the control group,fish fed the 8%HDPE diet had significantly decreased levels of protein and ash(P<0.05).In response to the increasing levels of HDPE exposure,the hepatosomatic index value,hepatocyte size,and liver glycogen level were increased,but lipid content was reduced in the liver tissues.Compared to the control treatment,fish fed the 8%HDPE diet had significant accumulations of total bile acids and different metabolism pathways such as bile acid biosynthesis,pyruvate metabolism,and carnitine synthesis.Significant enterocyte necrosis was documented in the foregut of fish fed the 2%or 8%HDPE diet;and significant cell sloughing was observed in the midgut and hindgut of fish fed the 8%HDPE diet.Fish fed the 2%HDPE diet harbored different microbiota communities compared to the control fish.This study demonstrates that HDPE ranging from 100 to 125 mm in feed can be evacuated by yellow perch with no impact on growth.However,dietary exposure to HDPE decreased whole fish nutrition quality,altered nutrient metabolism and the intestinal histopathology as well as microbiota community of yellow perch.The results indicate that extended exposure may pose a risk to fish health and jeopardize the nutrition quality of aquacultured end product.This hypothesis remains to be investigated further. 展开更多
关键词 Dietary exposure Intestinal microbiota Liver metabolomics Microplastics Nutrient composition Yellow perch
原文传递
仿猛禽机器人稳态栖息动力学建模及参数优化
15
作者 许勇 郭书言 魏馨梅 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第6期166-175,共10页
提出了一种在非结构化环境中具备可靠抓握和稳定栖息能力的仿猛禽机器人,求解了具有最小倾覆力矩的腿部最优尺寸,获得了满足倾覆力矩和动量约束的栖息成功参数域,设计了具有强大抓取力并通过自锁保持可靠抓握状态的欠驱动抓握腿爪.上述... 提出了一种在非结构化环境中具备可靠抓握和稳定栖息能力的仿猛禽机器人,求解了具有最小倾覆力矩的腿部最优尺寸,获得了满足倾覆力矩和动量约束的栖息成功参数域,设计了具有强大抓取力并通过自锁保持可靠抓握状态的欠驱动抓握腿爪.上述确保稳定栖息的动力学参数优化设计,以及确保可靠抓握的精巧腿爪结构,为实现仿猛禽栖息机器人在遥感探测、搜救避险、环境监测等非结构化环境中的广泛应用奠定了基础. 展开更多
关键词 仿猛禽机器人 稳态栖息模型 动量模型 栖息成功参数域 欠驱动抓握腿爪
下载PDF
Multiple model predictive control of perching maneuver based on guardian maps
16
作者 Rui CAO Huiwen WAN +1 位作者 Zhen HE Yuping LU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第5期347-360,共14页
Considering the strong nonlinearity of Unmanned Aerial Vehicles(UAVs)resulting from high Angle of Attack(AOA)and fast maneuvering,we present a multi-model predictive control strategy for UAV maneuvering,which has a sm... Considering the strong nonlinearity of Unmanned Aerial Vehicles(UAVs)resulting from high Angle of Attack(AOA)and fast maneuvering,we present a multi-model predictive control strategy for UAV maneuvering,which has a small amount of online calculation.Firstly,we divide the maneuver envelope of UAV into several sub-regions on the basis of the gap metric theory.A novel algorithm is then developed to determine the ploytopic model for each sub-region.According to this,a Robust Model Predictive Control based on the Idea of Comprehensive optimization(ICE-RMPC)is proposed.The control law is designed offline and optimized online to reduce the computational expense.Then,the ICE-RMPC method is applied to design the controllers of sub-regions.In addition,to guarantee the stability of whole closed-loop system,a multi-model switching control strategy based on guardian maps is put forward.Finally,the tracking performance of proposed control strategy is demonstrated by an illustrative example. 展开更多
关键词 Guardian maps Model predictive control Multi-Model switching rule Online comprehensive design perching maneuver
原文传递
Comparison for ecological economic performance of Chinese sea perch(Lateolabrax Maculatus)under different aquaculture systems
17
作者 Zhiyi Zhang Xiu Fang Longqi Sun 《Aquaculture and Fisheries》 2022年第6期683-692,共10页
Chinese sea perch(Lateolabrax Maculatus)is one of the main marine fish culture species in China,its green development has received increasing attention and its ecological economic study is rare.Based on field survey,t... Chinese sea perch(Lateolabrax Maculatus)is one of the main marine fish culture species in China,its green development has received increasing attention and its ecological economic study is rare.Based on field survey,this paper takes water pollution tax of China as conversion indicator for aquaculture eutrophication to simulate aquaculture waste fee for further analyzing the ecological impact of Chinese sea perch’s aquaculture.For data analysis,data envelopment analysis model has been used.The comparison for Chinese sea perch’s economic performance and ecological economic performance under its main aquaculture systems has been done.The results show that:1.The simulated waste fee has no significant impact for the comparison.2.Ranking for ecological economic performance’s ecological economic,technical and scale efficiency is as follow:pond farming,offshore cage culture and cage culture.3.Offshore cage culture is the only system presenting positive increase for ecological economic performance,which makes its aquaculture activity more sustainable than other systems.4.The key point of green development is to maximize the ecological economic efficiency of main aquaculture systems.Thus,offshore cage culture is the most sustainable aquaculture system among China’s current marine fish culture systems,and other systems need innovation for achieving the green development of China’s aquaculture. 展开更多
关键词 Chinese sea perch(Lateolabrax maculatus) Ecological economic performance Pond farming Cage culture Data envelopment analysis
原文传递
鲈鱼陆基循环水生态养殖的智能化管理技术及其应用前景
18
作者 黎永科 《现代畜牧科技》 2024年第5期151-154,共4页
鲈鱼陆基循环水生态养殖是一种新型的养殖模式,具有高效、环保、安全等优点。智能化管理技术在该领域的应用,能实现养殖过程的自动化、智能化,提高养殖效益,降低环境污染,为水产养殖业的可持续发展提供有力支持。该文对鲈鱼陆基循环水... 鲈鱼陆基循环水生态养殖是一种新型的养殖模式,具有高效、环保、安全等优点。智能化管理技术在该领域的应用,能实现养殖过程的自动化、智能化,提高养殖效益,降低环境污染,为水产养殖业的可持续发展提供有力支持。该文对鲈鱼陆基循环水生态养殖的智能化管理技术进行了深入的研究,并对其在实践中的应用前景进行了探讨,同时也为水产养殖业的可持续发展提供了新的思路。 展开更多
关键词 鲈鱼 陆基循环水 生态养殖 智能化管理
下载PDF
基于WPT-ARO-DBN/WPT-EPO-DBN模型的月含沙量多步预测
19
作者 高雪梅 崔东文 《人民珠江》 2024年第3期69-78,共10页
准确的含沙量多步预测对于区域水土流失治理、防洪减灾等具有重要意义。为提高含沙量多步预测精度,改进深度信念网络(DBN)的预测性能,基于小波包变换(WPT),分别提出人工兔优化(ARO)算法、鹰栖息优化(EPO)算法与DBN组合的月含沙量多步预... 准确的含沙量多步预测对于区域水土流失治理、防洪减灾等具有重要意义。为提高含沙量多步预测精度,改进深度信念网络(DBN)的预测性能,基于小波包变换(WPT),分别提出人工兔优化(ARO)算法、鹰栖息优化(EPO)算法与DBN组合的月含沙量多步预测模型,通过云南省龙潭站月含沙量时序数据对模型进行验证。首先利用WPT对实例月含沙量时序数据进行3层分解处理,得到8个更具规律的子序列分量;其次介绍ARO、EPO算法原理,利用ARO、EPO对DBN隐藏层神经元数等超参数进行寻优,建立WPT-ARO-DBN、WPT-EPO-DBN预测模型,并构建WPT-PSO(粒子群算法)-DBN、WPT-DBN作对比分析模型;最后利用4种模型对各子序列分量进行预测,将预测值叠加得到最终月含沙量多步预测结果。结果表明:(1)WPT-ARO-DBN、WPT-EPO-DBN模型对实例超前1步—超前4步月含沙量具有满意的预测效果,对超前5步具有较好的预测结果,对超前6步、超前7步的预测效果一般,对超前8步的预测精度较差,已不能满足预测精度需求;(2)WPT-ARO-DBN、WPT-EPO-DBN模型的多步预测效果要优于WPT-PSO-DBN模型,远优于WPT-DBN模型,具有更高的预测精度、更好的泛化能力和更大的预测步长;(3)ARO、EPO能有效优化DBN超参数,提高DBN预测性能,优化效果优于PSO,WPT-ARO-DBN、WPT-EPO-DBN模型能充分发挥WPT、新型群体智能算法和DBN网络优势,提高月含沙量多步预测精度,且预测精度随着预测步数的增加而降低。 展开更多
关键词 月含沙量预测 深度信念网络 人工兔优化算法 鹰栖息优化算法 小波包变换 组合模型
下载PDF
Sweet and Sour Boneless Chinese Perch
20
作者 ZHU XIPENG 《Women of China》 1995年第5期53-53,共1页
Ingredients: A fresh Chinese perch, about 1,500 grams; 50 grams diced carrot, 50 grams diced bamboo shoots, 50 grams diced dried mushroom, 50 grams peas, 1,000 grams vegetable oil, 50 grams sugar, 25 grams tomato past... Ingredients: A fresh Chinese perch, about 1,500 grams; 50 grams diced carrot, 50 grams diced bamboo shoots, 50 grams diced dried mushroom, 50 grams peas, 1,000 grams vegetable oil, 50 grams sugar, 25 grams tomato paste, salt, vinegar, cooking wine, MSG and cornstarch. Directions: 展开更多
关键词 cooking PASTE SWEET bamboo MUSHROOM tomato perch vegetable DRIED fresh
原文传递
上一页 1 2 15 下一页 到第
使用帮助 返回顶部