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Search Results: 1 - 10 of 33665 matches for " 张瑜龙 "
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内部流动中激波与边界层的干扰问题
张瑜
力学与实践 , 1983,
Abstract: 激波与边界层的干扰或相互作用,是处于流体力学,气体动力学和工程热物理学科发展前缘的重大应用基础理论课题。J.Ackeret,F.Feldman,N.Rott以及H.W.Liepmann等人1946年开始比较系统地研究了这一现象,在他们的实验中,分别独立地改变气流M数和Re数,所得结果对这一复杂的现象提供了一些说明。但由于它涉及激波与边界层这两个本来就比较复杂的问题,所以三十多年来虽有
钱学森先生指导下的科大力学系火箭小组
张瑜
力学与实践 , 2009, DOI: 10.6052/1000-0992-lxysj2009-471
Abstract: 我是中国科学技术大学近代力学系第一届(即07系58级)学生。在大学一、二年级时,我担任钱学森先生亲自指导的科大力学系火箭小组秘书组的组长。2008年9月,在科大校庆50周年之际,中国科学技术大学出版社出版了我编著的《钱学森与中国科学技术大学力学系火箭小组》一书。翻开1998年科大档案馆和校长办公室编印的《中国科学技术大学大事记》,在1958年12月27日栏下记载的唯一事件是
钱学森先生指导下的科大力学系火箭小组
张瑜
力学与实践 , 2009, DOI: 10.6052/1000-0992-2009-471
Abstract: 我是中国科学技术大学近代力学系第一届(即07系58级)学生。在大学一、二年级时,我担任钱学森先生亲自指导的科大力学系火箭小组秘书组的组长。2008年9月,在科大校庆50周年之际,中国科学技术大学出版社出版了我编著的《钱学森与中国科学技术大学力学系火箭小组》一书。翻开1998年科大档案馆和校长办公室编印的《中国科学技术大学大事记》,在1958年12月27日栏下记载的唯一事件是
内部流动中激波与边界层的干扰问题
张瑜
力学与实践 , 1983, DOI: 10.6052/1000-0992-1983-125
Abstract: 激波与边界层的干扰或相互作用,是处于流体力学,气体动力学和工程热物理学科发展前缘的重大应用基础理论课题。J.Ackeret,F.Feldman,N.Rott以及H.W.Liepmann等人1946年开始比较系统地研究了这一现象,在他们的实验中,分别独立地改变气流M数和Re数,所得结果对这一复杂的现象提供了一些说明。但由于它涉及激波与边界层这两个本来就比较复杂的问题,所以三十多年来虽有...
思想是图书馆学界的话语权
张瑜
图书馆杂志 , 2013,
Abstract: ?贡献出具有世界影响力或公认推进人类文明的思想,是图书馆学发展的重要依据。图书馆学理论健康发展和理性塑造之路:一要创造思想,二要冲出思想牢笼。
GC-MS分析使用不同提取工艺获得的沙枣花挥发性成分
张瑜
- , 2018, DOI: 10.13982/j.mfst.1673-9078.2018.7.036
Abstract: 这项研究采用水蒸气蒸馏法、有机溶剂浸提法、真空泵抽取吸附采集法、固相微萃取法以及超临界CO2萃取法对新疆沙枣花挥发油进行提取,并探讨不同提取方法对沙枣花挥发性化合物成分的影响。通过气相色谱-质谱(GC-MS)联用技术对沙枣花挥发油的化学成分进行分析鉴定,用峰面积归一法确定各组分的相对含量。共分离鉴定出139种化合物,其中共检测出烃类22种(占21.3%)、醛类10种(占1.38%)、酯类47种(占62.18%)、酮类7种(占0.6%)、醇类21种(占9.52%)、酸类14种(占1.86%)、苯环类7种(占1.66%)、酚类5种(占1.14%)、其它物质6种(占0.33%)。其中共有成分4种,分别是2,3-丁二醇、苯乙酸乙酯、苯乙醇、反式-肉桂酸乙酯。
In this study, steam distillation, organic solvent extraction, vacuum pump extraction and adsorption, solid phase microextraction (SPME), and supercritical CO2 extraction were used to extract the volatile oil of E. angustifolia flower grown in Xinjiang, and examined the effects of these different extraction methods on of the profile of the obtained volatile compounds. Gas chromatography-mass spectrometry (GC-MS) was used to analyze and identify the chemical constituents of volatile oil from the E. angustifolia flowers, with the relative amount of each component being determined using the peak area normalization method. A total of 139 compounds were isolated and identified, including 22 hydrocarbon (21.3%), 10 aldehydes (1.38%), 47 esters (62.18%), 7 ketones (0.6%), 21 alcohols (9.52%), 14 acids (1.86%), 7 benzenes (1.66%), 5 phenols (1.14%), and 6 other species (0.33%). Among which, four kinds of components, namely2,3- butanediol, ethyl phenylacetate, phenethyl alcohol and ethyl trans-cinnamate were found.
不同解冻技术对冷冻香菇(L.edodes)品质的影响
张瑜
- , 2016, DOI: 10.13982/j.mfst.1673-9078.2016.9.035
Abstract: 本文研究常温空气、冷藏、微波(119、259和280 W)以及超高压(100、150和200 MPa)解冻对香菇品质(色泽、汁液流失率、硬度、离子渗透率以及总酚含量)和解冻时间的影响。结果表明:与常温空气和冷藏解冻相比,微波和超高压解冻能够显著缩短香菇的解冻时间,并且随着微波功率和压强的增大,解冻时间逐渐缩短。但超高压解冻后香菇色泽与硬度显著下降,离子渗透率显著上升,从而使得香菇品质显著降低;而微波解冻在色泽(总色差降低19.9~44.1%)、硬度(升高18.9~38.0%)、汁液流失率(降低45.7~42.0%)、总酚含量(升高21.1~25.2%)和其他生理指标方面都优于常温空气解冻技术。其中,259 W的微波功率是香菇解冻的最优条件,同时该条件的感官评价分值最高(7.1)。本文表明微波解冻能够显著提高香菇的解冻速率和品质,这对香菇加工具有一定意义。
Different thawing methods (air ambient temperature thawing; refrigerator thawing; microwave thawing at 119, 259, and 280 W; and high-pressure thawing at 100, 150, and 200 MPa) were tested for their effects on the thawing time and quality attributes (color, drip loss, hardness, total phenolic content, and ion permeability) of frozen Lentinus edodes cubes. Both microwave thawing and high-pressure thawing could significantly shorten the thawing time of the frozen samples compared with air or refrigerator thawing, with the thawing time decreasing with increasing microwave power or processing pressure. The sample thawed by high pressure exhibited a dramatic decrease in color and hardness and a pronounced increase in ion permeability, thus resulting in a dramatic decrease in the quality of Lentinus edodes. However, microwave thawing significantly improved the quality attributes of the mushroom samples in terms of color (total color difference reduced by 19.9~44.1%), hardness (increased by 18.9~38.0%), drip loss (reduced by 45.7~42.0%), and total phenolic content (increased by 21.1~25.2%) compared with air ambient temperature thawing. The result suggests that microwave thawing at 259 W is the best method for thawing Lentinus edodes cubes with the highest sensory score (7.1). This study indicates that microwave thawing can significantly enhance both the thawing rate and quality attributes for Lentinus edodes, and shows a certain value to the processing of this mushroom species.
电感耦合等离子体原子发射光谱法测定铌铁中的三元素
Determine Three Elements in Ferroniobium with ICP-AES Method
 [PDF]

孙秀萍, 张瑜, 吴庆梅, 余海, 叶翠, 皮宁宁
Advances in Analytical Chemistry (AAC) , 2014, DOI: 10.12677/AAC.2014.42004
Abstract:

研究了用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定铌铁中三元素铜、铝、磷的分析方法。试样以硝酸、氢氟酸分解,加入硫酸加热至冒烟,再加入柠檬酸溶液,定容。然后在最佳谱线和最佳工作条件下测定。试验结果表明,该方法简便、快速、灵敏,检测限在0.004%至0.009%之间,线性范围较宽,相对标准偏差均较小,回收率在96%~104%之间。
A method for the determination of three elements—copper, aluminum and phosphorus in ferroniobium by inductively coupled plasma atomic emission spectrometry (ICP-AES) was studied. In the experiment, the sample is decomposed by nitric acid and hydrofluoric acid. Sulphuric acid was added to heat for smoking. Then citric acid was added. After constant volume, the sample was determined under optimal spectral lines and proper working conditions. The determined result shows that this method is simple, rapid and sensitive, with the detection limit between 0.004% and 0.009%, and the linear range is wide. The deviations were less than that of the standard deviations. Recovery rate was between 96% - 104%.

基于傅里叶变换的植物根系图像拼接方法
宋文,张瑜,袁得春
北京理工大学学报 , 2012,
Abstract: 提出一种基于傅里叶变换的植物根系图像拼接方法.采用快速傅里叶变换方法提高图像处理质量,缩短图像处理时间,实现图像实时处理,便于图像处理和数据统计.算例应用该方法将微根管采集到的植物根系图像拼接成一个完整的根系图像.结果表明该方法可以为生长在固坡中植物的作用机理研究提供全面的根系生长信息,进一步为植物根系的研究提供可靠的数据源.
脂多糖对猪肝脏、肾脏和小肠组织中P-糖蛋白表达的影响
张瑜,郭荔,豆丹丹,任伟,王丽平
南京农业大学学报 , 2015, DOI: 10.7685/j.issn.1000-2030.2015.02.020
Abstract: [目的] P-糖蛋白(P-gp)是影响底物药物口服生物利用度至关重要的因素。本试验旨在探究脂多糖(LPS)对猪肝脏、肾脏和小肠组织中P-gp定位和表达的影响,为临床合理有效用药提供理论支持。[方法]采用免疫组织化学SABC法结合DAB显色技术,用抗P-gp的单抗C219对相关组织的P-gp进行定位,进一步采用Image-Pro Plus软件对猪肝脏、肾脏、空肠和回肠中P-gp的表达进行半定量分析,检测LPS处理对P-糖蛋白定位和表达的影响。[结果]猪肝脏组织中的P-gp均主要分布于肝细胞间的胆小管细胞膜上,LPS处理3 h后P-gp表达量显著上升(P<0.05),6 h后可降至正常水平。猪肾脏中P-gp主要分布于近端小管和远端小管的细胞膜上,LPS处理6 h后P-gp表达量会显著升高(P<0.05)。猪空肠和回肠中P-gp主要分布于小肠绒毛上皮顶端和小肠腺靠近腔面细胞的顶端,LPS处理3 h后在空肠中表达有上升趋势,在6 h时表达量会降低至正常水平,但是LPS处理后对猪回肠中P-gp的表达未产生显著影响(P>0.05)。[结论]LPS处理对猪肝脏、肾脏、空肠和回肠中P-gp的定位无影响,但LPS处理3~6 h后可引起P-gp的表达量增加,推测其会对P-gp底物药物在猪体内的药动学过程和临床药效产生一定影响。
[Objectives] P-glycoprotein(P-gp)plays a crucial role in the bioavailability of many oral drugs, thus limiting their therapeutic potential. We sought to elucidate the effect of lipopolysaccharide(LPS)on the localization and expression of P-gp in liver, kidney, jejunum and ileum in swine. [Methods]The immunohistochemical SABC method combined with DAB staining method was used to localize the P-gp in tissues of swine with C219 as anti-P-gp monoclonal antibody in this study. Imagepro-plus software was used for semi-quantitative analysis of specific staining of P-gp. [Results]The immunohistochemical results showed that P-gp was distributed in the bile canalicular membrane between hepatocytes in liver of the swine. But compared with those of control group, positive staining of P-gp obviously increased after LPS treatment for 3 h(P<0.05), and then declined to normal level at 6 h. In kidney, the main staining was observed in the membrane of proximal tubule and distal tubule in both healthy and LPS treated pigs, and the expression of P-gp significantly increased after LPS treatment for 6 h(P<0.05). In jejunum and ileum, the special staining of P-gp was visualized mainly on the apical surface of the small intestine villi and glandular epithelium in both health and LPS treated swine. And the intensity was enhanced following LPS treatment for 3 h(P<0.05)but decreased to normal leval after 6 h in the jejunum. No significant difference was found in ileum(P>0.05). [Conclusions]The results suggested that the tissues localization of P-gp can not be changed, but the expression level of P-gp could increase following LPS treatment for 3 to 6 h, which may have potential role in changing the pharmacokinetics and pharmacodynamic of substrate drugs of P-gp in swine
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