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The Antimutagenic and Anticarcinogenic Effects of Tea, Garllc and Other Natural Foods in China: A Review 被引量:4
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作者 CHEN JUNSHIInstitute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, 29 Nan WeiRoad, Beijing 100050, China 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1992年第1期1-17,共17页
It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, c... It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, cancer mortality rates for most cancers were found to be more than 20-fold greater in some counties in others (Table 1). Esophageal cancer rates for males are a few hundred fold greater in the highest county when compared with the lowest county. The mortality rate for all cancers combined for males is 21 fold greater in the county with the highest mortality than in the county with the lowest rate.According to Doll and Peto (1981), about one third of human cancer death is avoidable by appropriate modification of the diet. Therefore, diet is very likely to have an important part in causing these huge geographic variations. The possible role of various mutagens and carcinogens (e.g. afiatoxin, N-nitroso compounds) in locally produced and consumed foods has been strongly suggested and widely acknowledged, although much more evidence would be required to confirm their actual functions in human cancer. On the other hand, there are a few reports stating that the human diet also contains powerful antimutagens and anticarcinogens (Ames, 1983). The possible role of these two types of substances in causing the huge geographic variation of cancer risks remains elusive and inadequately explored. In order to make better use of these natural anticarcinogens in cancer prevention, it is important to elucidate their effects and mechanisms. The purpose of this paper is to summarize the available information on the antimutagenic and anticarcinogenic effects of natural foods in the Chinese diet, excluding the effects of essential nutrients, e.g. dietary fibers, vitamins and minerals. Most of the literature cited in this review was published by Chinese scientists. 展开更多
关键词 The Antimutagenic and Anticarcinogenic Effects of tea A Review Garllc and Other natural Foods in China
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Manufacturing Process Selection of “Green” Oil Palm Natural Fiber Reinforced Polyurethane Composites Using Hybrid TEA Criteria Requirement and AHP Method for Automotive Crash Box 被引量:2
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作者 N.S.B.Yusof S.M.Sapuan +1 位作者 M.T.H.Sultan M.Jawaid 《Journal of Renewable Materials》 SCIE EI 2020年第6期647-660,共14页
In this study,the best manufacturing process will be selected to build an automotive crash box using green oil palm natural fibre-reinforced polyurethane composite materials.This paper introduces an approach consist o... In this study,the best manufacturing process will be selected to build an automotive crash box using green oil palm natural fibre-reinforced polyurethane composite materials.This paper introduces an approach consist of technical aspects(T),the economic point of view(E)and availability(A),and it’s also called as TEA requirement.This approach was developed with the goal of assisting the design engineer in the selection of the best manufacturing process during the design phase at the criteria selection stage.In this study,the TEA requirement will integrate with the analytical hierarchy process(AHP)to assist decision makers or manufacturing engineers in determining the most appropriate manufacturing process to be employed in the manufacture of a composite automotive crash box(ACB)at the early stage of the product development process.It is obvious that a major challenge in the manufacturing selection process is lack of information regarding manufacturing of ACB using natural fibre composite(NFC).There have been no previous studies that examined ranking manufacturability processes in terms of their suitability.Therefore,the TEA-AHP hybrid method was introduced to provide unprejudiced criteria-ranking selection prior to evaluation of pairwise comparisons.At the end of this study,the pulforming process was selected as the best manufacturing process for fabrication of the ACB structural component. 展开更多
关键词 Manufacturing process selection automotive crash box natural fibre composites tea requirement
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Counteraction of Nogo-A and axonal growth inhibitors by green tea polyphenols and other natural products 被引量:3
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作者 Tiffany K.Fan Usha Gundimeda +1 位作者 William J.Mack Rayudu Gopalakrishna 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第4期545-546,共2页
Neuronal injuries such as stroke,traumatic brain injury,and spinal cord injury are leading causes of major disability and death.Chronic therapy for these neuronal injuries requires the promotion of axonal regeneration... Neuronal injuries such as stroke,traumatic brain injury,and spinal cord injury are leading causes of major disability and death.Chronic therapy for these neuronal injuries requires the promotion of axonal regeneration from the remaining neurons(Schwab and Strittmatter,2014). 展开更多
关键词 EGCG Counteraction of Nogo-A and axonal growth inhibitors by green tea polyphenols and other natural products
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Investigation of SARS-CoV-2 Main Protease Potential Inhibitory Activities of Some Natural Antiviral Compounds Via Molecular Docking and Dynamics Approaches
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作者 Nada M.Mostafa Muhammad I.Ismail +5 位作者 Amr M.El-Araby Dina M.Bahgat Ahmed M.Elissawy Ahmed M.Mostafa Omayma A.Eldahshan Abdel Nasser B.Singab 《Phyton-International Journal of Experimental Botany》 SCIE 2022年第5期1089-1104,共16页
Coronaviruses caused an outbreak pandemic disease characterized by a severe acute respiratory distress syndrome leading to the infection of more than 200 million patients and the death of more than 4 million individua... Coronaviruses caused an outbreak pandemic disease characterized by a severe acute respiratory distress syndrome leading to the infection of more than 200 million patients and the death of more than 4 million individuals.The primary treatment is either supportive or symptomatic.Natural products have an important role in the development of various drugs.Thus,screening of natural compounds with reported antiviral activities can lead to the discovery of potential inhibitory entities against coronaviruses.In the current study,an in-silico molecular docking experiment was conducted on the effects of some of these natural antiviral phytoconstituents,(e.g.,procyanidin B2,theaflavin,quercetin,ellagic acid,caffeoylquinic acid derivatives,berginin,eudesm-1β,6α,11-triol and arbutin),on the crystal structure of SARS-CoV-2 main protease(PDB ID:6w63)using AutoDock-Vina software.Many of the docked compounds revealed good binding affinity,with procyanidin B2(–8.6 Kcal/mol)and theaflavin(–8.5 Kcal/mol)showing a better or similar binding score as the ligand(–8.5 Kcal/mol).Molecular dynamics simulations were carried out at 100 ns and revealed that procyanidin B2 forms a more stable complex with SARS-CoV-2 main protease than theaflavin.Procyanidin B2,theaflavin,and 4,5-dicaffeoylquinic acid were evaluated for toxicity by ProTox-II webserver and were non-toxic according to the predicted LD50 values and safe on different organs and pathways.Additionally,these phytoconstituents showed good ADME properties and acceptable lipophilicity,as evaluated using WLOGP.Amongst the tested compounds,procyanidin B2 showed the highest lipophilic value.It is worth mentioning that these natural inhibitiors of SARS-CoV-2 main protease are components of green and black tea that can be used as a supporting supplement for COVID patients or as potential nuclei for further drug design and development campaigns. 展开更多
关键词 CORONAVIRUS natural products SARS-CoV-2 main protease molecular docking molecular dynamics tea
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Use of Natural Antioxidants in Meat and Meat Products 被引量:8
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作者 M. Karakaya E. Bayrak K. Ulusoy 《Journal of Food Science and Engineering》 2011年第1期1-10,共10页
Antioxidants are used to minimize lipid oxidation. Antioxidants can act as metal chelators and free radical or oxygen scavengers, which can slow the progression of lipid oxidation. Lipid oxidation may have negative ef... Antioxidants are used to minimize lipid oxidation. Antioxidants can act as metal chelators and free radical or oxygen scavengers, which can slow the progression of lipid oxidation. Lipid oxidation may have negative effects on the quality of meat and meat products, causing changes in sensory attributes such as color, texture, odor and flavor, and nutritional quality. Several synthetic antioxidants have been used to successfully prevent lipid oxidation in the meat industry, but consumers are concerned about the health risks related to consumption of some synthetic antioxidants. Therefore, there has been a growing interest in natural antioxidants. Nowadays, compounds obtained from natural sources such as grains, oilseeds, spices, fruit and vegetables have been investigated to decrease the lipid oxidation. In this review, the potential effects of natural antioxidants were evaluated that are widely used in meat and meat products. 展开更多
关键词 natural antioxidants HERBS SPICES teaS FRUITS VEGETABLES meat products
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Natural Resource Conditions and Economic Development in the Uttaranchal Himalaya,India 被引量:1
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作者 Vishwambhar Prasad Sati 《Journal of Mountain Science》 SCIE CSCD 2005年第4期336-350,共15页
Uttaranchal is bestowed with numerous rivers, huge forest resources ranging from tropical to temperate, tourists' places, pilgrimages and feasible climatic conditions for growing fruits, vegetables, food grains, live... Uttaranchal is bestowed with numerous rivers, huge forest resources ranging from tropical to temperate, tourists' places, pilgrimages and feasible climatic conditions for growing fruits, vegetables, food grains, livestock rearing, tea garden practices, etc. The economic development, on the other hand, could not take place partly due to lack of modern technology with innovation in agricultural system and also unwillingness of the people towards using it. Furthermore, due to its harsh climatic conditions, rigorous terrain and distinct identity, as a part of Uttar Pradesh state, the development could not take place and today the state is believed to be one of the poorer states. Infrastructurally, this region is lagged behind due to its inaccessibility. The ideal geographical and agrarian conditions might be used evenly for the developmental processes. Ecologically, the whole region is socio-economic activities, fragile. The diverse harsh traditional beliefs and hard working potentials further change the entire scenario of the state. Only the need of the hours is to frame and implementation of the rational policies and planning for sustainable development of the state. What had appeared during the past, pertaining to the economic development, needs radical changes in policies, planning and beliefs. This paper aims to evaluate the present conditions of resources as a form of natural vegetation, agricultural crops, horticultural farming, herbs, tea garden practices, livestock rearing, hydropower projects and economic development of the Uttaranchal Himalaya. 展开更多
关键词 Climatic condition livestock rearing tea economic development natural resource agricultural system infrastructure socio-economic condition
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不同管理方式的武夷水仙岩茶品质差异及其形成的物质基础
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作者 吴全金 周喆 +4 位作者 林馥茗 漆思雨 周明帅 彭良清 孙威江 《热带作物学报》 CSCD 北大核心 2024年第3期576-591,共16页
福建水仙属于小乔木型茶树,是加工武夷岩茶的主要品种之一。目前,武夷山茶园管理过程中存在水仙茶树自然生长的现象(不修剪),其制茶品质与修剪水仙有明显区别。为明确自然生长和修剪条件下,武夷水仙岩茶的香气和呈味物质基础及其差异,... 福建水仙属于小乔木型茶树,是加工武夷岩茶的主要品种之一。目前,武夷山茶园管理过程中存在水仙茶树自然生长的现象(不修剪),其制茶品质与修剪水仙有明显区别。为明确自然生长和修剪条件下,武夷水仙岩茶的香气和呈味物质基础及其差异,本研究采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)和高效液相色谱(high performance liquid chromatography,HPLC)技术,结合多元统计分析,探寻自然生长和修剪下武夷水仙岩茶在焙火前(毛茶)和焙火后(成品茶)香气物质、滋味成分与品质的内在联系。结果表明:利用GC-MS技术共鉴定出261种挥发物;通过主成分分析(principal component analysis,PCA)与正交偏最小二乘判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)可知,自然生长水仙茶树和修剪水仙茶树制成的毛茶和成品茶的香气物质差异明显。与修剪水仙毛茶相比,自然生长水仙毛茶有41种挥发性物质存在显著差异(筛选差异标准:VIP>1,且FC≥1.5或FC≤0.67),己酸己酯、植物醇、异植醇、反式-橙花叔醇等花果香物质的相对含量更高;而β-雪松烯、γ-杜松烯、2-甲氧基呋喃等相对含量更低。与修剪水仙成品茶相比,自然生长水仙成品茶有71种挥发性物质存在显著差异,呈果香型的己酸己酯、己酸甲酯、反式-橙花叔醇、(Z)-β-法呢烯、1-庚醇、2-庚酮等挥发物,呈烘烤香型的3-乙基-1H-吡咯、2-甲酰基-4,5-二甲基吡咯、乙基甲基吡嗪等挥发物的相对含量更高。修剪水仙和自然生长水仙茶焙火前后的香气物质也存在很大差异,分别有91和70种差异物质。通过香气活性值(aroma activity value,OAV)分析表明,(E)-3-己烯醇、吲哚、反式-橙花叔醇、环氧-β-紫罗兰酮、(E)-芳樟醇氧化物、2-苯乙醇、水杨酸甲酯可能是自然生长水仙香气形成的重要物质。主要呈味物质分析表明,自然生长和修剪水仙茶的儿茶素组分和咖啡碱存在明显差异。感官审评结果与理化检测结果一致,表现为自然生长水仙茶花果香浓郁,滋味醇厚,品质更佳。本研究对科学管理茶园和茶叶品质调控有指导作用。 展开更多
关键词 武夷水仙 自然生长 修剪 毛茶 成品茶
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TTLD-YOLOv7:非结构化环境下茶树病害的检测算法
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作者 俞淑燕 杜晓晨 +1 位作者 冯海林 李颜娥 《茶叶科学》 CAS CSCD 北大核心 2024年第3期453-468,共16页
茶树病害对茶树种植业和相关行业的影响极为严重。在动态而复杂的茶园环境中检测疾病的传统方法效率低下,检测效果不尽人意。本研究提出一种基于YOLOv7-tiny的模型,增强了茶树病害的细微检测能力。通过整合CoordConv和ECA信道关注机制,... 茶树病害对茶树种植业和相关行业的影响极为严重。在动态而复杂的茶园环境中检测疾病的传统方法效率低下,检测效果不尽人意。本研究提出一种基于YOLOv7-tiny的模型,增强了茶树病害的细微检测能力。通过整合CoordConv和ECA信道关注机制,本模型在卷积特征图中实现了更高的空间识别能力,并降低了背景噪声对特征识别的影响。进一步的改进包括采用归一化瓦瑟斯坦距离度量和去耦头,以提高对小病斑的检测能力。使用K-means算法根据茶树病斑的特殊性生成了新的锚框,提高了模型的精确性和通用性。对比分析表明,该模型优于现有模型FasterR-CNN、 SSD、 YOLOv5s、 YOLO-Tea、 YOLOv7-tiny和YOLOv7,平均精确度提高5.39个百分点,达到了93%。改进后的模型可应用于茶树病害监测。 展开更多
关键词 茶树病害 YOLOv7-tiny 自然环境 目标检测
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TEA+MEA混合胺液脱除天然气中CO_2吸收性能 被引量:5
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作者 唐建峰 青霞 +5 位作者 张新军 徐明海 黄彬 李晶 史泽林 杨帆 《天然气化工—C1化学与化工》 CAS CSCD 北大核心 2015年第5期24-28,33,共6页
为适应寻找经济、高效的新型天然气脱碳吸收剂的需求,研究了由三乙醇胺(TEA)和一乙醇胺(MEA)组成的混合胺溶液。实验考察了单一胺和不同比例的混合胺的吸收性能,确定了两种胺的最佳混合比例。结果表明,在TEA中添加MEA能够显著提升其CO2... 为适应寻找经济、高效的新型天然气脱碳吸收剂的需求,研究了由三乙醇胺(TEA)和一乙醇胺(MEA)组成的混合胺溶液。实验考察了单一胺和不同比例的混合胺的吸收性能,确定了两种胺的最佳混合比例。结果表明,在TEA中添加MEA能够显著提升其CO2吸收效果,优化比例的混合胺具有更好的CO2吸收负荷、吸收速率和吸收稳定性。 展开更多
关键词 三乙醇胺 一乙醇胺 混合胺液 天然气 二氧化碳 吸收性能
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有机和常规管理对茶园土壤固碳的影响——以林地为对照
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作者 郑玉婷 黄鑫慧 +6 位作者 李浩 王彪 李攀锋 崔吉晓 隋鹏 高旺盛 陈源泉 《中国生态农业学报(中英文)》 CSCD 北大核心 2024年第1期53-60,共8页
为探究有机和常规管理方式对茶园土壤有机碳的影响,选择云南省普洱市思茅区常规管理茶园、有机管理茶园和附近自然林地3种典型土地利用类型,通过测定0~20 cm和20~40 cm土层的土壤有机碳(SOC)、易氧化有机碳(EOC)、非活性有机碳(NLOC)、... 为探究有机和常规管理方式对茶园土壤有机碳的影响,选择云南省普洱市思茅区常规管理茶园、有机管理茶园和附近自然林地3种典型土地利用类型,通过测定0~20 cm和20~40 cm土层的土壤有机碳(SOC)、易氧化有机碳(EOC)、非活性有机碳(NLOC)、颗粒态有机碳(POC)和矿物结合态有机碳(MOC)含量,计算土壤各组分有机碳的分配比例以及土壤碳库管理指数(CPMI),研究3种土地利用方式下土壤有机碳各组分含量和质量的变化特征。结果显示:1)常规管理茶园的SOC含量和储量分别比自然林地低48.67%~51.94%和27.25%~35.71%(P<0.05),而有机管理茶园的SOC含量和储量比常规管理茶园分别高52.09%~62.86%、15.54%~20.26%(P<0.05)。2)常规管理茶园的EOC、NLOC、POC和MOC含量均低于自然林地(P<0.05),而有机管理茶园的EOC、NLOC、POC和MOC含量比常规管理茶园分别高出46.39%~57.89%、54.24%~66.15%、80.87%~121.01%和40.07%~46.28%(P<0.05)。3)与自然林地相比,常规管理茶园的POC/SOC、NLOC/SOC较低,有机管理茶园的POC/SOC、NLOC/SOC则高于常规管理茶园。4)常规管理茶园具有较高的CPAI和较低的CPMI,常规管理茶园的CPMI比自然林地低24.53%~46.12%,有机管理茶园的CPMI比常规管理茶园高67.88%~100.33%,其差异均显著(P<0.05)。以上研究结果表明,与自然林地相比,常规管理的茶园土壤有机碳含量和土壤碳库质量下降,存在一定程度的土地退化,而有机管理是提高茶园土壤碳库质量的有效措施。 展开更多
关键词 茶园 有机管理 土壤有机碳 土壤碳库管理指数 自然林地
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茶天然产物缓解痤疮的作用机制研究进展
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作者 吴致远 王凯博 +2 位作者 陈思霖 赵碧 申时全 《茶叶科学》 CAS CSCD 北大核心 2024年第1期16-26,共11页
茶因其明确的保健功能与健康益处备受人们青睐。随着对茶活性成分的深入研究,茶天然产物已被证实能够对多种疾病模型具有改善效果。痤疮是一种流行性高、复发率高的炎性皮肤病,除传统临床诊疗外,以敷贴、皮肤护理、膳食改善为代表的补... 茶因其明确的保健功能与健康益处备受人们青睐。随着对茶活性成分的深入研究,茶天然产物已被证实能够对多种疾病模型具有改善效果。痤疮是一种流行性高、复发率高的炎性皮肤病,除传统临床诊疗外,以敷贴、皮肤护理、膳食改善为代表的补充替代治疗也受到欢迎。目前市场上,越来越多的祛痘功效宣称产品在原料中添加茶源活性成分,以茶多酚、咖啡碱、茶氨酸、茶皂素为代表的茶叶天然产物在缓解痤疮上表现出极大的潜力。综述了茶叶不同功效成分在抑制皮脂分泌、减轻粉刺发生、改善皮肤微生物失调、减缓皮肤局灶性炎症的作用及分子机制,以期为含茶功效宣称产品的研发提供参考。 展开更多
关键词 天然产物 缓解 痤疮
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聚多巴胺/壳聚糖改性棉织物的茶色素染色及其抗菌和防紫外线性能
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作者 李丽丽 袁亮 +2 位作者 唐雨霞 杨文菊 王浩 《纺织学报》 EI CAS CSCD 北大核心 2024年第3期106-113,共8页
为提高棉织物的天然色素染色性和多功能性,利用CuSO_(4)/H_(2)O_(2)氧化体系下多巴胺(DA)在织物表面快速聚合沉积后,采用壳聚糖(CS)整理制备聚多巴胺/壳聚糖(PDA/CS)改性棉织物,再用茶色素对其进行染色处理。探究了DA快速聚合沉积过程... 为提高棉织物的天然色素染色性和多功能性,利用CuSO_(4)/H_(2)O_(2)氧化体系下多巴胺(DA)在织物表面快速聚合沉积后,采用壳聚糖(CS)整理制备聚多巴胺/壳聚糖(PDA/CS)改性棉织物,再用茶色素对其进行染色处理。探究了DA快速聚合沉积过程中各因素对改性棉织物染色性能的影响,得到较佳工艺条件:CuSO_(4)浓度为3 mmol/L,DA质量浓度为2.0 mg/mL,H_(2)O_(2)浓度为13 mmol/L,沉积时间为2 h。在此条件下,PDA/CS改性棉织物染色后的K/S值达到6.21。研究结果表明:CuSO_(4)/H_(2)O_(2)氧化体系下DA在棉织物表面形成PDA层,可与CS产生氢键作用在织物表面均匀成膜;茶色素染色PDA/CS改性棉织物的耐摩擦色牢度、耐皂洗色牢度(沾色)和耐人造光色牢度均达到4级及以上;PDA/CS改性织物染色后的UPF值为312,对金黄色葡萄球菌与大肠杆菌的抑菌率达到90%以上,具备抗菌和防紫外线的双重功效。 展开更多
关键词 棉织物 聚多巴胺 壳聚糖 茶色素染色 天然染料 功能整理
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3种抗氧化剂对冷藏猪肉抗氧化与抑菌效果的初步研究
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作者 钟杨 杨明星 +4 位作者 吴珊 张清胜 魏明梅 刘倩 刘文龙 《成都大学学报(自然科学版)》 2024年第3期248-254,共7页
为提高冷藏猪肉货架期品质,利用不同浓度(0.1%、0.3%和0.5%)的茶多酚、葡萄籽提取物和维生素C 3种天然抗氧化剂处理生鲜猪肉.通过测定贮藏过程中菌落总数、硫代巴比妥酸值、挥发性盐基氮值、羰基含量和总巯基含量等指标的变化,以及对采... 为提高冷藏猪肉货架期品质,利用不同浓度(0.1%、0.3%和0.5%)的茶多酚、葡萄籽提取物和维生素C 3种天然抗氧化剂处理生鲜猪肉.通过测定贮藏过程中菌落总数、硫代巴比妥酸值、挥发性盐基氮值、羰基含量和总巯基含量等指标的变化,以及对采用抗氧化剂处理后冷藏猪肉的脂肪酸含量变化进行分析,比较不同浓度3种天然抗氧化剂对猪肉品质的影响.结果表明,经3种天然抗氧化剂浸泡处理后,均能有效抑制冷藏猪肉微生物的生长繁殖及脂肪氧化,同时延缓蛋白质水解,降低饱和脂肪酸;贮藏12 d时,0.5%茶多酚组的菌落总数和挥发性盐基氮值含量分别为4.85 lg(CFU/g)和8.81 mg/100 g,明显低于对照组和其他处理组,硫代巴比妥酸值略高于0.5%葡萄籽提取物组(0.221 mg/kg),为0.225 mg/kg.综合菌落总数、硫代巴比妥酸值、挥发性盐基氮值、羰基含量、总巯基含量和脂肪酸组成分析,0.5%茶多酚组具有最优的保鲜效果. 展开更多
关键词 生鲜猪肉 茶多酚 葡萄籽提取物 维生素C 天然抗氧化剂 保鲜
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哀牢山楚雄片区野生种古茶树生存现状分析与管护探讨
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作者 徐萍 罗文富 +4 位作者 张志强 苏家红 李根会 覃忠义 李函 《中国茶叶》 2024年第4期72-76,共5页
通过对哀牢山楚雄片区野生种古茶树生存现状分析,探讨该片区野生种古茶树管护经营模式,提出科学可行的对策建议,以改善野生种古茶树生存现状。调查结果表明,云南哀牢山国家级保护区楚雄片区野生种古茶树均为大理茶种,以单株分散生长为主... 通过对哀牢山楚雄片区野生种古茶树生存现状分析,探讨该片区野生种古茶树管护经营模式,提出科学可行的对策建议,以改善野生种古茶树生存现状。调查结果表明,云南哀牢山国家级保护区楚雄片区野生种古茶树均为大理茶种,以单株分散生长为主,资源总量较少;天然和天然萌生各占一半,生长前期茶树主干遭受损坏,生长情况一般,生长势主要处于中等状态,幼树更新旺盛,但较大树木较少,竞争后期可能出现衰退的趋势。研究区的野生种古茶树生存现状不够理想,除自然因素干扰以外,管护措施也不到位,仍需加强资源保护力度,注重宣传保护和科研开发协调平衡,破除制约野生种古茶树生存发展障碍,实现地区野生种古茶树资源发展最大化。 展开更多
关键词 野生种古茶树 哀牢山自然保护区 茶树资源 古茶树管护
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应用GC/TEA法测定天然胶乳橡胶避孕套中可迁移亚硝胺
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作者 宁丽峰 果吉尔锑 +2 位作者 原思渊 郭颖志 周越 《中国计划生育学杂志》 2014年第1期33-37,共5页
目的:验证国际标准ISO29941((天然胶乳橡胶避孕套中可迁移亚硝胺的测定》中步骤B的方法“利用气相色谱/热能分析仪(GC/TEA)测定天然胶乳橡胶避孕套中可迁移亚硝胺含量”在我国的适用度。方法:抽样选取我国市场上销售的10个厂家2... 目的:验证国际标准ISO29941((天然胶乳橡胶避孕套中可迁移亚硝胺的测定》中步骤B的方法“利用气相色谱/热能分析仪(GC/TEA)测定天然胶乳橡胶避孕套中可迁移亚硝胺含量”在我国的适用度。方法:抽样选取我国市场上销售的10个厂家20个批次的天然胶乳橡胶避孕套,根据国际标准ISO29941方法中的步骤B,将避孕套在水中浸提10min后,用二氯甲烷萃取,再经干燥和浓缩后利用GC/TEA检测从避孕套中迁移出的亚硝胺含量,内标法定量。结果:在检测的20批避孕套中,共6种亚硝胺被检出,迁移量分别为:N-亚硝基二甲胺,1.4~10.2ng/g,检出率55%;N-亚硝基二乙胺,1.3~6.7ng/g,检出率80%;N-亚硝基二丁胺,O.8~6.9ng/g,检出率20%;N-亚硝基哌啶,5.7ng/g,检出率5%;N-亚硝基吡咯烷,2.3ng/g,检出率5%;N-亚硝胺甲乙胺,2.5~9.7ng/g,检出率65%。总亚硝胺迁移量为4.6~18.2ng/g。结论:本方法简便、快速、准确,可以满足天然胶乳橡胶避孕套中可迁移亚硝胺的测定要求。 展开更多
关键词 避孕套 N-亚硝胺 气相色谱 热能分析仪 迁移量
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《周礼》重“漆林之征”考
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作者 张文静 《农业考古》 北大核心 2024年第1期78-87,共10页
《周礼》所构建的赋税体系中,有一条现今并未发现在先秦两汉时期实际实施过的征课政策,即“唯其漆林之征二十而五”,对漆林进行高税率课税。后世学者对此非常科税收政策,遵循两条解释理路:一为“抑末”、二为“返朴”。不过,这两种解释... 《周礼》所构建的赋税体系中,有一条现今并未发现在先秦两汉时期实际实施过的征课政策,即“唯其漆林之征二十而五”,对漆林进行高税率课税。后世学者对此非常科税收政策,遵循两条解释理路:一为“抑末”、二为“返朴”。不过,这两种解释与《周礼》文本都不够契合。本文通过考察古代中国经济作物的征税政策,结合《周礼》文本与唐代茶税出现的历史背景,对漆林征课做出解释。 展开更多
关键词 漆林之征 抑末 返朴 唐代茶税
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植物皂苷对染色头发外观的影响
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作者 梁菁 张伟雄 +1 位作者 马铃 陈雅 《中国洗涤用品工业》 CAS 2024年第9期73-79,共7页
研究对比了典型植物皂苷茶皂素以及4种洗发水常用表面活性剂对染色头发外观的影响。采用头发颜色测试仪测定头发的L^(*)、a^(*)、b^(*)值并计算洗涤前后的头发色差ΔE,参考GB/T 13174-2021测定5种表面活性剂对脂质、蛋白质两种成分的脱... 研究对比了典型植物皂苷茶皂素以及4种洗发水常用表面活性剂对染色头发外观的影响。采用头发颜色测试仪测定头发的L^(*)、a^(*)、b^(*)值并计算洗涤前后的头发色差ΔE,参考GB/T 13174-2021测定5种表面活性剂对脂质、蛋白质两种成分的脱除能力。结果表明:无论是用氧化型染发剂还是半永久型染发剂染色的头发,茶皂素处理后的头发色差ΔE都比较小,说明茶皂素能够维持染后头发颜色的稳定,具有较好的头发护色性能,这可能与茶皂素对脂质和蛋白质的低反应性有关。在此基础上配制了含有茶皂素的洗发水,对其的发色护理功效评价结果显示,含有茶皂素的洗发水有助于维持染发后头发颜色的稳定,具有发色护理的功效。 展开更多
关键词 植物皂苷 茶皂素 头发色差 发色护理
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意境营造在茶禅空间设计中的应用研究
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作者 程茂杰 王旭 《鞋类工艺与设计》 2024年第7期88-90,共3页
本文将以茶文化中的文化内涵与意境营造相结合为切入点,结合茶禅文化深入研究如何在满足审美要求的基础上,为空间设计提供坚实的理论支撑和实践指南,并提出科学合理的设计思路。目前随着社会的发展和人们物质生活水平的提高,现代人们对... 本文将以茶文化中的文化内涵与意境营造相结合为切入点,结合茶禅文化深入研究如何在满足审美要求的基础上,为空间设计提供坚实的理论支撑和实践指南,并提出科学合理的设计思路。目前随着社会的发展和人们物质生活水平的提高,现代人们对精神生活的需求日益提升。茶文化作为中国传统文化的重要组成部分,因其独特的修身养性功能而受到广泛的关注。因此,茶禅空间的发展应运而生,并呈现出多样化的趋势。然而,当前茶禅空间的品质参差不齐,存在缺乏文化内涵支撑、过于追求形式等问题。为了解决这些问题,提出茶禅空间设计布局的方向以及具体方法。 展开更多
关键词 茶禅空间 自然元素 人文精神 意境营造
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绿茶外泌体样纳米颗粒(ELNs)延缓人体成纤维细胞衰老作用研究
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作者 程敏 宋景鋈 +5 位作者 雷轩灏 李皓楠 陈思贝 赵进 管峰 葛建 《茶叶通讯》 2024年第3期391-400,共10页
探究绿茶外泌体样纳米颗粒(ELNs)及其复方配伍对人体表皮成纤维细胞衰老模型的干预作用。通过超速离心法结合蔗糖密度梯度离心,提取纯化绿茶ELNs,采用透射电镜、粒径检测以及脂质组学分析对ELNs进行体外表征。CCK-8法证明24 h内ELNs对... 探究绿茶外泌体样纳米颗粒(ELNs)及其复方配伍对人体表皮成纤维细胞衰老模型的干预作用。通过超速离心法结合蔗糖密度梯度离心,提取纯化绿茶ELNs,采用透射电镜、粒径检测以及脂质组学分析对ELNs进行体外表征。CCK-8法证明24 h内ELNs对人体表皮成纤维细胞具有明显诱导增殖功能;生化分析和分子检测显示,ELNs能显著提高人体表皮成纤维细胞超氧化物歧化酶(SOD)、谷胱甘肽过氧化酶(GSH-px)活力,降低丙二醛(MDA)含量,并提高羟脯氨酸(HYP)、Ⅲ型胶原蛋白(COL3)含量,同时抑制基质金属蛋白酶-1(MMP-1)、P53和P16基因的表达。与番茄红素复配,具有显著协同抗衰老作用。结果表明绿茶ELNs及其复方能显著延缓人成纤维细胞衰老,主要干预细胞生化代谢过程和相关基因表达。 展开更多
关键词 绿茶外泌体样纳米颗粒(ELNs) 天然活性分子 成纤维细胞 衰老
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Synthesis of clay-supported nanoscale zero-valent iron using green tea extract for the removal of phosphorus from aqueous solutions 被引量:6
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作者 Akbar Soliemanzadeh Majid Fekri 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第7期924-930,共7页
This study addresses the synthesis of nanoscale zero-valent iron(n ZVI) in the presence of natural bentonite(B-n ZVI) using green tea extract. The natural bentonite and B-n ZVI were then applied for the removal of pho... This study addresses the synthesis of nanoscale zero-valent iron(n ZVI) in the presence of natural bentonite(B-n ZVI) using green tea extract. The natural bentonite and B-n ZVI were then applied for the removal of phosphorus from aqueous solutions at various concentrations, p H levels and contact time. The desorption of phosphorus(P) from adsorbents was done immediately after sorption at the maximum initial concentration using the successive dilution method. The characterization of FTIR, SEM, and XRD indicated that n ZVI was successfully loaded to the surface of natural bentonite. The sorption of phosphorus on B-n ZVI was observed to be p H-dependent, with maximum phosphorus removal occurring at the p H range of 2 to 5. The results demonstrate that the maximum sorption capacities of natural bentonite and B-n ZVI were 4.61 and 27.63 mg·g^(-1), respectively.Langmuir, Freundlich, and Redlich–Peterson models properly described the sorption isotherm data. For either adsorbent, desorption isotherms did not coincide with their corresponding sorption isotherms, suggesting the occurrence of irreversibility and hysteresis. The average percentages of retained phosphorus released from natural bentonite and B-n ZVI were 80% and 9%, respectively. The results indicated that sorption kinetics was best described by the pseudo-second-order model. The present study suggests that B-n ZVI could be used as a suitable adsorbent for the removal of phosphorus from aqueous solutions. 展开更多
关键词 Green tea Nano zero-valent iron natural bentonite PHOSPHORUS SORPTION
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