期刊文献+
共找到4,316篇文章
< 1 2 216 >
每页显示 20 50 100
Effects of Ethanol Condensation Reflux Extraction and Ultrasound-assisted Extraction on the Content of Total Flavonoids of Pueraria edulis
1
作者 Jun TANG Jianguang ZENG +1 位作者 Hao LI Chenzhong JIN 《Agricultural Biotechnology》 CAS 2023年第2期91-95,104,共6页
With Pueraria edulis from different habitats in Yunnan Province,Guangdong Province and Guangxi Zhuang autonomous region as materials,the medicinal materials of P.edulis were extracted by ethanol condensation reflux ex... With Pueraria edulis from different habitats in Yunnan Province,Guangdong Province and Guangxi Zhuang autonomous region as materials,the medicinal materials of P.edulis were extracted by ethanol condensation reflux extraction and ultrasound-assisted extraction,and the effects of different extraction methods the contents of total flavonoids in P.edulis from different areas were compared.The results showed that the best extraction time for P.edulis in Yunnan Province was 20 min,and that for Guangdong and Guangxi Zhuang Autonomous Region was 30 min.The yield of total flavonoids from P.edulis extracted by the condensation reflux extraction method was relatively better.The content of total flavonoids in P.edulis in Yunnan was the highest with an average content of 0.2557%,while the average content of total flavonoids in P.edulis in Guangdong was the lowest with an average content of 0.2108%. 展开更多
关键词 Pueraria edulis Total flavonoids Condensation reflux extraction method ultrasound-assisted extraction
下载PDF
Endoplasmic reticulum stress improved chicken tenderness,promoted apoptosis and autophagy during postmortem ageing
2
作者 Yuwei Chai Lin Chen +4 位作者 Shuya Xiang Linxuan Wu Xuebo Liu Jun Luo Xianchao Feng 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期2141-2151,共11页
In this study,endoplasmic reticulum(ER)stress inducer tunicamycin(TM)and inhibitor 4-phenylbutyric acid(4-PBA)were used to treat postmortem chicken breast muscle to investigate changes in tenderness and effects on apo... In this study,endoplasmic reticulum(ER)stress inducer tunicamycin(TM)and inhibitor 4-phenylbutyric acid(4-PBA)were used to treat postmortem chicken breast muscle to investigate changes in tenderness and effects on apoptosis and autophagy during 5 days ageing.TM-induced ER stress reduced shear force,enhanced myofibril fragmentation index(MFI),disrupted myofibril structure,increased desmin degradation,and activatedμ-calpain and caspase-12.In addition,TM-induced ER stress increased the expression of Bax,Bim,and cytochrome c,and decreased the expression of Bcl-x L.Furthermore,TM-induced ER stress improved the conversion of LC3I to LC3II,raised the expression of Beclin-1,and decreased the expression of p62,PI3K,and m TOR.The opposite results were observed after 4-PBA treatment.These results suggested that ER stress could improve chicken tenderness,promote apoptosis and autophagy during chicken postmortem ageing. 展开更多
关键词 Endoplasmic reticulum stress tenderNESS APOPTOSIS AUTOPHAGY CHICKEN
下载PDF
Analyses of Chicken Tenderness Traits Based on Transcriptome Sequencing
3
作者 Zengrong ZHANG Mohan QIU +6 位作者 Chunlin YU Xia XIONG Xiaoyan SONG Bo XIA Shiliang ZHU Jialei CHEN Chaowu YANG 《Agricultural Biotechnology》 2024年第2期17-19,共3页
The calpain system is ubiquitous in cells, mainly comprising calpains and calpain inhibitors, and is a widespread calcium-dependent cysteine protease in organisms that is involved in many cellular processes such as mu... The calpain system is ubiquitous in cells, mainly comprising calpains and calpain inhibitors, and is a widespread calcium-dependent cysteine protease in organisms that is involved in many cellular processes such as muscle degradation in vivo and affects the tenderness of meat after animal slaughter. The study found 128 DEGs that probably regulated tenderness traits were selected from 16 significantly enriched GO terms by transcriptome sequencing analysis, and found that the developmental changes in the expression levels of the CAPN1 gene in the pectoral and leg muscles were significantly positively correlated ( P <0.05) with the cumulative growth values of live weight and comb weight. The developmental changes in the expression levels of the CAST gene in the pectoral and leg muscles were not significantly correlated with the cumulative growth values of live weight and comb weight. Our results helped demonstrate the potential molecular mechanisms of tenderness in chickens and provide valuable information for chicken breeding. 展开更多
关键词 CHICKEN tenderness traits Transcriptome sequencing
下载PDF
Application of Bromelain Extract for Muscle Foods Tenderization 被引量:5
4
作者 Sunantha Ketnawa Saroat Rawdkuen 《Food and Nutrition Sciences》 2011年第5期393-401,共9页
This study investigates the tenderizing effects of bromelain extract (BE) obtained from the top phase of an aqueous two-phase system comprising of 18% PEG 6000–17% MgSO4 in muscle foods. Uniform-sized chunks of beef,... This study investigates the tenderizing effects of bromelain extract (BE) obtained from the top phase of an aqueous two-phase system comprising of 18% PEG 6000–17% MgSO4 in muscle foods. Uniform-sized chunks of beef, chicken, and squid were marinated with different concentrations of BE (0, 3, 7%, and 20%, w/w) for 1 h at room temperature. The physico-chemical and quality characteristics of the marinated samples were determined. Decreases in pH and moisture content were observed in the samples BE treated, but the TCA-soluble peptides content significantly increased (p < 0.05). Water holding capacity and cooking yields were observed in all of the tested samples, especially when the concentration of BE increased. In addition, a reduction of meat firmness and toughness were also observed in all of the samples when compared to the control (p < 0.05). Electrophoretic patterns also revealed extensive proteolysis and a reduction in number and intensity of the protein bands in all of the treated samples. At the microstructural level, tissue fibers were broken, cell membranes were more strongly degraded, the connections between the sarcolemma and the myofibrils were disappeared, and the generation of numerous gaps could be clearly observed when 20% (w/w) BE was added. The results show that the bromelain extract derived from the two-phase extraction of a pineapple peel could be used as an effective meat tenderizer. 展开更多
关键词 BROMELAIN PINEAPPLE PEEL Aqueous Two Phase System MUSCLE Food MEAT tenderization
下载PDF
Optimization of ultrasound-assisted extraction of camptothecin from Camptotheca acuminata seeds 被引量:2
5
作者 JING Li-jia LI Si-yang CHANG Zui WANG Yang YAN Xiu-feng 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第2期239-242,共4页
Naturally occurring camptothecin(CPT) is an important source of chemotherapeutic agents.The extraction from Camptotheca acuminata is still the main approach to obtain CPT compared with total synthesis.In the present... Naturally occurring camptothecin(CPT) is an important source of chemotherapeutic agents.The extraction from Camptotheca acuminata is still the main approach to obtain CPT compared with total synthesis.In the present study,ultrasound-assisted extractions(UAE) of CPT from C.acuminata seeds with alkaline solutions were investigated and CPT yield were determined by High Performance Liquid Chromatography.The conditions of alkaline species and concentrations,extraction time,extraction temperature and ultrasonic power were optimized.Results show that both Na3PO4 and Na2CO3 solutions gain good extraction yields,whereas Na3PO4 solution has stronger basicity and need higher concentration than Na2CO3 solution does,thus aqueous Na2CO3 is more beneficial for the extraction.The optimal condition was ultrasonically extracted with 0.5% aqueous Na2CO3 at 50°C and ultrasonic power of 400 W for 60 min.Comparing with UAE with ethanol,the extraction with 0.5% Na2CO3 solution achieves higher yield.Moreover,aqueous Na2CO3 as a solvent has various advantages including non-toxicity,inflammable,non-corrosive and low cost,which ensure this UAE method is a superior method with high utilizing prospect. 展开更多
关键词 CAMPTOTHECIN Camptotheca acuminata ultrasound-assistant extraction
下载PDF
Ionic Liquid-Based Ultrasound-Assisted Emulsification Microextraction Coupled with HPLC for Simultaneous Determination of Glucocorticoids and Sex Hormones in Cosmetics 被引量:1
6
作者 Xiaoji Cao Lingxiao Shen +3 位作者 Xuemin Ye Feifei Zhang Jiaoyu Chen Weimin Mo 《Green and Sustainable Chemistry》 2013年第2期26-31,共6页
An effective and environmentally friendly method based on ionic liquid-based ultrasound-assisted emulsification microextraction(IL-USAEME) and high performance liquid chromatography (HPLC) has been developed for the d... An effective and environmentally friendly method based on ionic liquid-based ultrasound-assisted emulsification microextraction(IL-USAEME) and high performance liquid chromatography (HPLC) has been developed for the determination of nine hormones including three glucocorticoids, one androgen and five progestogens in cosmetics. Several factors that affect the extraction efficiency, such as the kinds and volume of ionic liquid, salt concentration, ultrasonic power and time, and centrifugation time were investigated and optimized. Under the optimum extraction condition, the recoveries of analytes ranged from 85.97% to 108.84% except prednisolone (62.30%). The intraday and interday precision was below 2.51% and 3.30%, respectively. 展开更多
关键词 Ionic LIQUID ultrasound-assisted EMULSIFICATION MICROEXTRACTION HORMONES COSMETICS High Performance LIQUID Chromatography
下载PDF
Pectinmethylesterase extraction from orange solid wastes: Optimization and comparison between conventional and ultrasound-assisted treatments
7
作者 Antonio D. Rodriguez-Lopez Luis Mayor +2 位作者 María M. Galfarsoro Jorge Martinez-Otalo Esperanza M. Garcia-Castello 《Agricultural Sciences》 2013年第9期45-50,共6页
During orange juice production, a half of fresh oranges weight is considered as production waste (peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative for the management of these wastes is thei... During orange juice production, a half of fresh oranges weight is considered as production waste (peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative for the management of these wastes is their treatment by addition of lime and a latter pressing, obtaining a press cake and a press liquor rich in sugars (10&#176;Brix) and citric acid, protein, pectin and ethanol. For non-thermal concentration of press liquor to obtain citruss molasses (65&#176;-70&#176;Brix), the removal of pectin is necessary. Traditionally, depectinization of juices has been done by using pectinmethylesterase (PME) enzymes from external sources. In this work it performed the extraction of PME enzymes from orange peels to obtain the optimum extraction conditions. Two different methods of solventextraction were compared (conventional andultrasound-assisted methods). For the conventional extraction experiments, a central composite design with three variables ([NaCl], pH and time) and five replicates of the center point was used. For ultrasound-assisted extraction, experiments were done at pH = 5.5 and [NaCl] = 1.25M), varying extraction time (1-30 min). Response variables were PME activity, protein content and a ratio between them, named PME effectiveness (ηPME). At the same experimental conditions (pH =5.5, [NaCl] = 1.25 M, t = 15 min) it was found that conventional extractions led to slightly better results in terms of ηPME than ultrasound-assisted extraction method. 展开更多
关键词 ORANGE Peel SOLID-LIQUID EXTRACTION ultrasound-assisted EXTRACTION PECTINMETHYLESTERASE Press Liquor
下载PDF
Effect of Ultrasound-Assisted Extraction of Phenolic Compounds on the Characteristics of Walnut Shells
8
作者 Hannah Han Shusheng Wang +3 位作者 Milan Rakita Yanting Wang Qingyou Han Qin Xu 《Food and Nutrition Sciences》 2018年第8期1034-1045,共12页
Walnuts are one of nature’s more waste-heavy products. 67% of the nut is shell and husk, low value by-products that are rich in phenolic compounds. The phenolic compounds extracted from walnut shells are potentially ... Walnuts are one of nature’s more waste-heavy products. 67% of the nut is shell and husk, low value by-products that are rich in phenolic compounds. The phenolic compounds extracted from walnut shells are potentially good natural sources of antioxidants for the food and pharmaceutical industries. In this study, phenolic compounds were extracted using an ultrasonic bath, an ultrasonic probe and a standard shaking method. The extraction yield achieved with an ultrasonic probe was 51.2 mg GAE/g DW, two times higher than both the shaking method and the ultrasonic bath method which were 20.6 mg GAE/g DW and 25.8 mg GAE/g DW, respectively. Phenolic extraction was further improved by a size reduction of the walnut shells. The best extraction yield of 52.8 mg GAE/g DW was attained when the particle size was between 45 - 100 mesh. The ultrasonic probe treatment is the best method for extraction of phenolic compounds from walnut shells. Scanning electron microscopy (SEM) imaging indicated that the ultrasonic probe treatment could better rupture the hard structure of the cells, increasing the penetration of solvents and thus the extraction yield. 展开更多
关键词 WALNUT SHELL ultrasound-assisted Extraction TOTAL PHENOLIC Content (TPC) Particle Size SEM Analysis
下载PDF
Analysis of anticancer compound,indole-3-carbinol,in broccoli using a new ultrasound-assisted dispersive-filter extraction method based on poly(deep eutectic solvent)-graphene oxide nanocomposite
9
作者 Yanan Yuan Huanhuan Chen +2 位作者 Yehong Han Fengxia Qiao Hongyuan Yan 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2022年第2期301-307,共7页
Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challengin... Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature.In this study,a rapid,accurate,and lowcost ultrasound-assisted dispersive-filter extraction(UADFE)technique based on poly(deep eutectic solvent)-graphene oxide(PDES-GO)adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time.PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption.UADFE was developed by combining dispersive solid-phase extraction(DSPE)and filter solid-phase extraction(FSPE)to realize rapid extraction and separation.Based on the above two strategies,the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography(HPLC)allowed the rapid(15-16 min),accurate(84.3%-96.4%),and low-cost(adsorbent:3.00 mg)analysis of I3C in broccoli and was superior to solid-phase extraction,DSPE,and FSPE methods.The proposed method showed remarkable linearity(r=0.9998;range:0.0840-48.0 mg/g),low limit of quantification(0.0840 mg/g),and high precision(relative standard deviation<5.6%).Therefore,the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples. 展开更多
关键词 INDOLE-3-CARBINOL BROCCOLI Poly(deep eutectic solvent)-graphene oxide ultrasound-assisted dispersive-filter extraction Rapid analysis
下载PDF
Ultrasound-Assisted Emulsification Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet for Separation of Trace Gold Prior to Flame Atomic Absorption Spectroscopy Determination
10
作者 Sayed Zia Mohammadi Mohammad Ali Karimi +1 位作者 Ali Shiebani Laleh Karimzadeh 《American Journal of Analytical Chemistry》 2011年第2期243-249,共7页
In the present work, a ultrasound-assisted emulsification dispersive liquid-liquid microextraction based on solidification of floating organic droplet method has been developed as a sample preparation method prior to ... In the present work, a ultrasound-assisted emulsification dispersive liquid-liquid microextraction based on solidification of floating organic droplet method has been developed as a sample preparation method prior to flame atomic absorption spectrometry determination of trace amounts of gold in the standard, wastewater and river water samples. In the proposed method, 1-dodecanol and 5-(4-dimethylamino-benzylidene) were used as extraction solvent and chelating agent, respectively. Several factors that may be affected on the ex-traction process, such as type and volume of the extraction solvent, ionic strength, pH of the aqueous solu-tion, extraction temperature and extraction time were studied and optimized. Under the best experimental conditions, the calibration curve exhibited linearity over the range of 8.0 ng●mL-1- 3.0 μg●mL-1 with a correlation coefficient of 0.9978 and detection limit based on three times the standard deviation of the blank signal was 1.5 ng●mL-1. Eight replicate determinations of 0.2 and 1.0 μg●mL-1 of gold gave a mean absorbance of 0.051 and 0.253 with relative standard deviations of ±2.3% and ±1.5%, respectively. Finally, the developed method was successfully applied to the extraction and determination of gold ions in a silica ore, wastewater, river water and standard samples and satisfactory results were obtained. 展开更多
关键词 ultrasound-assisted EMULSIFICATION Microextraction SOLIDIFICATION FLOATING ORGANIC DROPLET Preconcentration Gold Determination Silica Ore
下载PDF
樟树港辣椒高口感品质嫩果尖椒产业的发展
11
作者 邹学校 杨莎 +3 位作者 戴雄泽 朱凡 徐昊 远方 《中国蔬菜》 北大核心 2024年第7期1-5,共5页
樟树港辣椒已有200多年的栽培历史。本文重点介绍了樟树港辣椒嫩果尖椒的来源,高口感品质形成的机理,产业发展历史和存在问题。针对嫩果尖椒产业存在的问题,育成能满足不同市场需求的高品质嫩果尖椒新品种,研发高口感品质嫩果尖椒高产... 樟树港辣椒已有200多年的栽培历史。本文重点介绍了樟树港辣椒嫩果尖椒的来源,高口感品质形成的机理,产业发展历史和存在问题。针对嫩果尖椒产业存在的问题,育成能满足不同市场需求的高品质嫩果尖椒新品种,研发高口感品质嫩果尖椒高产栽培的技术,并迅速在全国推广。高口感品质嫩果尖椒迅速畅销全国,实现了周年均衡供应。樟树港辣椒由地方品牌提升为全国知名高端品牌,实现樟树港辣椒高口感品质嫩果尖椒向“樟树港辣椒”品牌高口感品质嫩果尖椒的飞跃。 展开更多
关键词 樟树港辣椒 高口感品质 嫩果尖椒 产业 育种与栽培
下载PDF
不同贮藏温度下半胱氨酸氧化位点鉴定及对滩羊肉嫩度的影响
12
作者 张瑞 陶迎梅 +2 位作者 高钰茸 王素也 刘敦华 《食品科学》 EI CAS CSCD 北大核心 2024年第10期54-61,共8页
以宁夏滩羊肉为材料,借助半胱氨酸氧化修饰蛋白质组学技术,对-80℃(对照)和-2、-18、4℃条件下贮藏7 d滩羊肉的品质指标(剪切力和质构特性(硬度、弹性和咀嚼性))进行测定,同时对半胱氨酸氧化修饰位点进行鉴定,结合Pearson法对显著差异... 以宁夏滩羊肉为材料,借助半胱氨酸氧化修饰蛋白质组学技术,对-80℃(对照)和-2、-18、4℃条件下贮藏7 d滩羊肉的品质指标(剪切力和质构特性(硬度、弹性和咀嚼性))进行测定,同时对半胱氨酸氧化修饰位点进行鉴定,结合Pearson法对显著差异氧化位点(significantly differential oxidation sites,SDOS)的氧化强度与冷藏滩羊肉品质指标进行相关性分析。结果表明,与对照组相比,3个贮藏组的剪切力和质构特性均显著下降(P<0.05),25个SDOS对应的蛋白(10个结构蛋白、8个代谢酶、2个降解酶和5个其他蛋白)与至少1个品质指标显著相关(P<0.05),可作为羊肉贮藏期间嫩度和质构变化的潜在生物标志物。 展开更多
关键词 滩羊肉 嫩度 半胱氨酸氧化修饰蛋白质组学 蛋白质氧化 质构
下载PDF
电针辅助治疗类风湿关节炎的疗效观察及对血清类风湿因子和炎症因子的影响
13
作者 王晓云 高宇 +1 位作者 文培培 刘益兵 《上海针灸杂志》 CSCD 2024年第4期428-433,共6页
目的观察电针足三里和关元穴辅助治疗类风湿关节炎(rheumatoid arthritis,RA)的临床疗效及对患者关节功能、关节压痛指数、红细胞沉降率、类风湿因子和炎症因子的影响。方法将112例RA患者用随机数字表法分为对照组和观察组,每组56例。... 目的观察电针足三里和关元穴辅助治疗类风湿关节炎(rheumatoid arthritis,RA)的临床疗效及对患者关节功能、关节压痛指数、红细胞沉降率、类风湿因子和炎症因子的影响。方法将112例RA患者用随机数字表法分为对照组和观察组,每组56例。对照组采用常规西医治疗,观察组在对照组治疗基础上予电针足三里和关元穴治疗。比较两组临床疗效和不良反应发生情况,观察两组治疗前后关节功能、关节肿胀指数、关节压痛指数、RA患者病情评价(disease activity score 28,DAS28)评分以及红细胞沉降率、类风湿因子、炎症因子[C-反应蛋白(C-reactive protein,CRP)、白介素-1β(interleukin-1β,IL-1β)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)]水平的变化。结果观察组总有效率高于对照组(P<0.05)。治疗后,两组关节功能(关节僵硬、疼痛和日常活动)评分、DAS28评分、关节肿胀指数和关节压痛指数以及红细胞沉降率、类风湿因子、CRP、TNF-α和IL-1β水平均低于治疗前(P<0.05),且观察组上述观察指标均低于对照组(P<0.05)。对照组1例出现咽部梗阻感,疑为甲氨蝶呤所致;有2例出现消化道不适症状。观察组2例出现针刺后皮下血肿,1例出现消化道不适症状。结论在常规西医治疗基础上,电针足三里和关元穴辅助治疗RA可提高临床疗效,有助于改善患者关节功能和关节压痛,降低红细胞沉降率、类风湿因子和炎症因子水平。 展开更多
关键词 针刺疗法 电针 关节炎 类风湿 关节功能 关节压痛 类风湿因子 炎症因子
下载PDF
复合益生菌对肉牛生长性能、肉质及免疫性能的影响
14
作者 谭春萍 李芳芳 +4 位作者 王英群 康超 黄雨惠 陈昊 刘文娟 《中国饲料》 北大核心 2024年第12期33-36,共4页
文章旨在研究复合益生菌对肉牛生长性能、肉质及免疫性能的影响,试验采用单因素随机试验设计,将45头健康月龄和体重相近的比利时白蓝牛随机分为3组,每组5个重复,每个重复3头牛。试验1组为对照组,饲喂基础日粮,试验2、3组分别在基础日粮... 文章旨在研究复合益生菌对肉牛生长性能、肉质及免疫性能的影响,试验采用单因素随机试验设计,将45头健康月龄和体重相近的比利时白蓝牛随机分为3组,每组5个重复,每个重复3头牛。试验1组为对照组,饲喂基础日粮,试验2、3组分别在基础日粮中添加200和400 mg/kg的复合益生菌,预饲验10 d,正试期60 d。结果表明,试验3组肉牛的生长性能、肉质及免疫性能显著提升(P<0.05);试验2组对肉牛生长性能、肉质及免疫性能均有一定的提高,但差异不显著(P>0.05)。综上所述,添加不同水平的复合益生菌可有效提高肉牛生长性能、肉质、免疫性能。建议在肉牛饲养过程中添加乳酸粪肠球菌、产朊假丝酵母菌、枯草芽孢杆菌(2∶2∶1),总活菌数≥1.3×10^(11)CFU/g的400 mg/kg的复合益生菌为宜。 展开更多
关键词 复合益生菌 生长性能 肉质 免疫性能
下载PDF
基于YOLOv5的茶叶嫩芽图像识别算法研究
15
作者 马志艳 李辉 《湖北工业大学学报》 2024年第1期36-40,共5页
现有的机器采茶都需要人工辅助进行采茶,且存在老叶、嫩芽一刀切的情况,会损害一部分茶叶,只适用于低端茶叶的采摘。因此,需要研究出一种精准高效的茶叶嫩芽识别方法。针对茶叶嫩芽图像背景复杂的问题,在YOLOv5算法的基础上,对算法进行... 现有的机器采茶都需要人工辅助进行采茶,且存在老叶、嫩芽一刀切的情况,会损害一部分茶叶,只适用于低端茶叶的采摘。因此,需要研究出一种精准高效的茶叶嫩芽识别方法。针对茶叶嫩芽图像背景复杂的问题,在YOLOv5算法的基础上,对算法进行多角度的改进,实验结果表明,改进算法的模型的mAP提升了4.1%,Recall提升了4.0%,且改进方法减少了漏检情况的发生。 展开更多
关键词 茶叶采摘 YOLOv5算法 机器学习 嫩芽识别
下载PDF
主动退市背景下余股强制挤出制度的构建
16
作者 张艳 《政治与法律》 北大核心 2024年第4期148-161,共14页
余股强制挤出制度不是对余股股东股权的侵夺,而是将已缩小为财产性利益的股权转化为经济补偿请求权,故完全符合我国宪法的规定。余股强制挤出制度可更精准地平衡控股股东与余股股东的利益冲突且有效解决余股困境,应尽快引入我国法律。... 余股强制挤出制度不是对余股股东股权的侵夺,而是将已缩小为财产性利益的股权转化为经济补偿请求权,故完全符合我国宪法的规定。余股强制挤出制度可更精准地平衡控股股东与余股股东的利益冲突且有效解决余股困境,应尽快引入我国法律。我国宜在要约收购型私有化退市中引入余股强制挤出制度,并遵循“或然关系模式”将挤出确定为私有化退市的特殊情形。应选择更为温和的“单一比例门槛”,并根据不同的股权分布情况设置差异化的挤出门槛阈值。在臂长交易情形,可直接将前序收购要约价格确定为挤出价格。在自我交易情形,宜制定整体主义视角下内外机制相结合的公平价格保障机制。鉴于挤出权与卖出权是互为镜像的一组权利,在引入挤出制度后,卖出权制度亟须进行联动修改。 展开更多
关键词 私有化 退市 余股强制挤出 要约收购 余股股东卖出权
下载PDF
特克赛尔羊×阿勒泰羊F_(2)绵羊肉质嫩度全基因组关联分析
17
作者 赵义龙 黄金凤 +1 位作者 贺三刚 刘明军 《家畜生态学报》 北大核心 2024年第4期22-26,共5页
为了定位影响绵羊嫩度相关SNP位点及其重要候选基因,该研究选取462只特克赛尔羊×阿勒泰羊F_(2)绵羊,其中公羔229只、母羔233只,所有试验羊均在统一条件下饲养至8月龄后进行屠宰,利用C-LM4嫩度仪对嫩度进行测定,利用Illumina绵羊高... 为了定位影响绵羊嫩度相关SNP位点及其重要候选基因,该研究选取462只特克赛尔羊×阿勒泰羊F_(2)绵羊,其中公羔229只、母羔233只,所有试验羊均在统一条件下饲养至8月龄后进行屠宰,利用C-LM4嫩度仪对嫩度进行测定,利用Illumina绵羊高密度(600K)SNP芯片进行基因分型,使用GEMMA软件的MLM模型对嫩度性状进行全基因组关联分析。结果表明,经质控后,剩余613178个SNPs位点用于全基因组关联分析,发现9个潜在SNPs位点与嫩度相关,分别分布在2、6、23、24号染色体上。根据基因生物学功能及相关研究文献,推测EREG、AREG、PDE1A基因参与肌肉再生、肌纤维形成等生物学过程,可作为影响嫩度的重要候选基因。研究结果可为利用分子生物学方法改良绵羊肌肉嫩度提供科学依据。 展开更多
关键词 嫩度 特克赛尔羊×阿勒泰羊 F_(2) 候选基因 全基因组关联分析 SNP
下载PDF
江汉水牛生产性能及经济效益研究
18
作者 韩安勤 黄彬 +3 位作者 黄祥春 李必圣 李友全 伍万宏 《养殖与饲料》 2024年第2期13-16,共4页
[目的]研究江汉水牛的主要体尺指标和生产性能,为江汉水牛保种和开发利用提供理论依据。[方法]测定20头2.5岁左右、平均体质量(360±59)kg江汉水牛(公牛10头、母牛10头)的主要体尺指标,并进行134d的强度育肥试验。育肥结束后,选取1... [目的]研究江汉水牛的主要体尺指标和生产性能,为江汉水牛保种和开发利用提供理论依据。[方法]测定20头2.5岁左右、平均体质量(360±59)kg江汉水牛(公牛10头、母牛10头)的主要体尺指标,并进行134d的强度育肥试验。育肥结束后,选取12头江汉水牛(公牛6头、母牛6头)进行屠宰和肉质性能测定。[结果]江汉水牛育肥期平均日增质量为(818±189) g,平均日采食量为26.87 kg。江汉水牛屠宰率为45.4%,净肉率37.6%,眼肌面积85.7 cm^(2),肌肉嫩度平均为80.35 kg/cm^(2),肌肉肉色评分7.83,滴水损失1.17%,江汉水牛产肉成本为27.57元/kg。[结论]江汉水牛躯体高大,骨骼粗壮,肉质优良,是培育乳肉兼用水牛新品种的良好遗传素材。 展开更多
关键词 江汉水牛 体尺指标 生产性能 屠宰性能 肌肉嫩度 滴水损失
下载PDF
地方与传统视域中的琦君创作
19
作者 李洪华 郑宜璇 《华文文学》 2024年第1期49-54,共6页
台湾地区作家琦君出生于江南,成长于江南,她的文学创作是从中国的地域文化与传统文化的土壤中所生发出来的。永嘉独特的风物民俗与其所附着的离恨乡愁,是琦君创作中“永嘉路径”的彰显;哀而不伤、温柔敦厚的文风,含蓄蕴藉、细腻节制的笔... 台湾地区作家琦君出生于江南,成长于江南,她的文学创作是从中国的地域文化与传统文化的土壤中所生发出来的。永嘉独特的风物民俗与其所附着的离恨乡愁,是琦君创作中“永嘉路径”的彰显;哀而不伤、温柔敦厚的文风,含蓄蕴藉、细腻节制的笔法,则是琦君在中国传统文化的浸润中所继承的“古典”传统。在二者的融汇之下,共同构筑了琦君细腻、温婉、隐秀的美学风格。 展开更多
关键词 琦君创作 永嘉路径 传统文化 温柔敦厚 哀而不伤
下载PDF
真空低温烹调技术对肉制品品质的影响研究进展 被引量:1
20
作者 张慢 熊晓筱 +3 位作者 刘俊 阚娟 千春录 金昌海 《食品工业科技》 CAS 北大核心 2024年第11期333-340,共8页
真空低温烹调(Sous vide)是在真空条件下进行的一种经严格控制温度和时间的烹调技术。与传统的烹调方法相比,真空低温烹调因能有效减少产品中营养成分的损失,保留食品的原有风味,改善肉制品嫩度等优势而受到大众关注,近几年被广泛研究... 真空低温烹调(Sous vide)是在真空条件下进行的一种经严格控制温度和时间的烹调技术。与传统的烹调方法相比,真空低温烹调因能有效减少产品中营养成分的损失,保留食品的原有风味,改善肉制品嫩度等优势而受到大众关注,近几年被广泛研究并应用于肉制品加工。本文主要综述了真空低温烹调技术加工条件和方式的改变对肉制品食用品质的影响,指出适宜的加热温度和时间能提高肉制品风味和嫩度、促进营养物质的保留,且低温长时间加热有助于提高肉类的安全性。同时本文还阐述了真空低温烹调与其他技术联用对产品嫩度和安全性的显著影响,为更好地促进真空低温烹调技术在肉制品精深加工中的应用和实现真空低温烹饪肉制品的工业化生产提供了理论依据。 展开更多
关键词 真空低温烹调 肉制品加工 风味 营养成分 嫩度 安全性
下载PDF
上一页 1 2 216 下一页 到第
使用帮助 返回顶部