期刊文献+
共找到2,972篇文章
< 1 2 149 >
每页显示 20 50 100
PARALLEL COMPOUND METHODS FOR SOLVING PARTITIONED STIFF SYSTEMS
1
作者 Li-rong Chen De-gui Liu 《Journal of Computational Mathematics》 SCIE EI CSCD 2001年第6期639-650,共12页
Deals with the solution of partitioned systems of nonlinear stiff differential equations. Discussion on parallel compound methods; Nonstiff equations; Order conditions of the parallel compound methods (PCM); Numerical... Deals with the solution of partitioned systems of nonlinear stiff differential equations. Discussion on parallel compound methods; Nonstiff equations; Order conditions of the parallel compound methods (PCM); Numerical stability of PCM. 展开更多
关键词 parallel compound methods stiff systems order conditions CONVERGENCE STABILITY
原文传递
Synthesis of Substituted u-Oxo-bis[tetra-phenyl porphyrinatoiron] Compounds from Free Base Porphyrins by a One-pot Method 被引量:2
2
作者 佘远斌 冯连顺 +1 位作者 王爱欣 李修艳 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第3期369-372,共4页
A novel method for synthesis of substituted μ-oxo-bis[tetraphenyl porphyrinatoiron] compounds ([TRPPFe]2O) based on the reaction among free base porphyrins (TRPPH2), FeSO4·7H2O and H2O in one pot was proposed an... A novel method for synthesis of substituted μ-oxo-bis[tetraphenyl porphyrinatoiron] compounds ([TRPPFe]2O) based on the reaction among free base porphyrins (TRPPH2), FeSO4·7H2O and H2O in one pot was proposed and investigated. Four kinds of [TRPPFe]2O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, infrared spectra and UV-vis spectroscopy. The reaction conditions, including the effect of different iron salts on the formation of [TRPPFe]2O, the reaction time between FeSO4·7H2O and TRPPH2, the molar ratio of FeSO4·7H2O/TRPPH2 as well as the volume ratio of H2O/DMF, were investigated. The [TRPPFe]2O yield of 93%-98% could be obtained under the following optimal conditions: the reaction time of FeSO4·7H2O with TRPPH2 was about 10 h, the molar ratio of FeSO4·7H2O/TRPPH2 about 5︰1, and the volume ra-tio of H2O/DMF exceeded 2︰1. Further research indicated that only TRPPFeCl were formed once FeSO4·7H2O was replaced by FeCl2·4H2O, the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe]2O, suggesting that halogen ions should be avoided in this novel synthetic method. 展开更多
关键词 一锅法 卟啉配体 合成 μ-氧代四苯基双核铁卟啉
下载PDF
ONE-CELL-STATE METHOD FOR DETERMINATION OF ELECTRONIC STRUCTURE OF INTERMETALLIC COMPOUNDS 被引量:2
3
作者 Gao Yingjun , Chen Zhenhua , Huang Peiyun and Zhong Xiaping Institute of Nonequilibrium Materials, Central South University of Technology, Changsha 410083, P. R. China Physical Department, Guangxi University, Nanning 530004, P 《中国有色金属学会会刊:英文版》 CSCD 1998年第4期19-24,共6页
INTRODUCTIONInrecentyears,thePauling’svalencebond(VB)theoryhasbenmadeagreatprogresindesigninganddeterminingt... INTRODUCTIONInrecentyears,thePauling’svalencebond(VB)theoryhasbenmadeagreatprogresindesigninganddeterminingtheatomicstate,and... 展开更多
关键词 ONE cell STATE method INTERMETALLIC compound ELECTRONIC STRUCTURE charge transfer Al 3Li
下载PDF
A meshless method for the compound KdV-Burgers equation 被引量:1
4
作者 程荣军 程玉民 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第7期41-46,共6页
The element-free Galerkin (EFG) method for numerically solving the compound Korteweg-de Vries-Burgers (KdVB) equation is discussed in this paper. The Galerkin weak form is used to obtain the discrete equation and ... The element-free Galerkin (EFG) method for numerically solving the compound Korteweg-de Vries-Burgers (KdVB) equation is discussed in this paper. The Galerkin weak form is used to obtain the discrete equation and the essential boundary conditions are enforced by the penalty method. The effectiveness of the EFG method of solving the compound Korteweg-de Vries-Burgers (KdVB) equation is illustrated by three numerical examples. 展开更多
关键词 element-free Galerkin (EFG) method meshless method compound Korteweg-de Vries-Burgers (KdVB) equation solitary wave
下载PDF
Validation of Microbial Limit Test Methods of Compound Gangbangui Capsule
5
作者 Xiangling QU Xianmei XU +1 位作者 Sibu MA Renhui YANG 《Agricultural Biotechnology》 CAS 2018年第2期105-108,共4页
[Objectives] This study was conducted to establish a method for microbial limit test of Compound Gangbangui Capsule. [Methods] According to the Chinese Pharmacopoei 2015 edition of the four general rules,the microbiol... [Objectives] This study was conducted to establish a method for microbial limit test of Compound Gangbangui Capsule. [Methods] According to the Chinese Pharmacopoei 2015 edition of the four general rules,the microbiological limits of non-sterile products were verified. [Results]Compound Gangbangui Capsule has a strong inhibitory effect on S. aureus,and the antimicrobial activity was significantly eliminated after increasing the diluent( 1∶ 20); and the recoveries were in the range of 0. 5-2. 0 when the total quantities of aerobic microbes were determined by dilution method( 1∶ 20). When the total quantities of mould and yeast were determined by conventional method( 1∶ 20),the recoveries were from 0. 5 to 2. 0,and Escherichia coli can be detected in experimental groups by the test solution dilution method. [Conclusions]With the plate method,the total quantities of aerobic bacteria and the quantities of mould and yeast were examined by increasing diluent and conventional method,respectively,and control bacteria,E. coli was examined by conventional method. This method has been proved effective for microbial limit test of Compound Gangbangui Capsule,and can effectively control the quality of the preparation. The method is accurate and reliable. 展开更多
关键词 compound Gangbangui Capsule Microbial limit test method Dilution methodHome
下载PDF
A Convenient Method for Dehydrogenation of Symmetric Hydrazo Compounds
6
《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期318-318,共1页
关键词 A Convenient method for Dehydrogenation of Symmetric Hydrazo compounds
下载PDF
Study on extracting alumina from fly ash by compound additive activation method
7
作者 WANG Yongwang 《Global Geology》 2014年第3期182-188,共7页
According to the chemical and mineral composition characteristics of the fly ash,alumina can be extracted from fly ash through the calcining method by using sodium carbonate and calcium carbonate additives.The effects... According to the chemical and mineral composition characteristics of the fly ash,alumina can be extracted from fly ash through the calcining method by using sodium carbonate and calcium carbonate additives.The effects on leaching rate of alumina have been investigated. The results showed that the fly ash can be activated effectively and the leaching rate of alumina can be improved to more than 92% through this method. The best process parameters were the ratio of raw materials,i. e. the material weight ratio of fly ash,calcium carbonate and sodium carbonate was 1. 0∶1. 2∶0. 9. The activating temperature was 850℃-900℃,activating time was 3 h. This process has a potential application prospect and improves the value of comprehensive utilization of fly ash. 展开更多
关键词 复合添加剂 激活方法 氧化铝 粉煤灰 提取 综合利用价值 工艺参数 活化温度
下载PDF
Discussion on the Quality Evaluation Method of Traditional Chinese Medicine Compound Preparations
8
作者 Jie LIANG Yushan ZHOU +4 位作者 Chenxi XIN Chuanchuan YANG Jinyu WEI Dongfang HUANG Lichun ZHAO 《Medicinal Plant》 CAS 2020年第1期11-16,共6页
As an important representative of the modernization of the Chinese medicine industry,traditional Chinese medicine(TCM)compound preparations are an indispensable part of the development of TCM.The complex ingredients a... As an important representative of the modernization of the Chinese medicine industry,traditional Chinese medicine(TCM)compound preparations are an indispensable part of the development of TCM.The complex ingredients and unclear action mechanism of TCM compound preparations restrict the development of TCM.In line with this problem,the modern TCM research has made extensive remarkable achievements.From the single indicator in the past to multiple indicator,the research on the combination of TCM fingerprints and pharmacodynamics also has made great progress.The introduction of quality evaluation methods such as the"quantitative analysis of multi-components by a single marker","dose-effect"indicator,"Bioactive Equivalent Combinatorial Components"(BECCs)and TCM quality markers have brought new ideas for quality control of TCM compound preparations. 展开更多
关键词 TRADITIONAL Chinese medicine(TCM) compound preparations QUALITY evaluation method
下载PDF
A NEW METHOD FOR SYNTHESIS OF O-ISOPROPYL SUBSTITUTED AROMATIC COMPOUNDS
9
作者 Xue Chao WANG Xin Fu PANState Key Laboratory of Applied Organic Chemistry,Lanzhou University,Lanzhou,730000 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第5期329-332,共4页
Heteroatom-directed aromatic lithiation reactions used for the regiospecific synthesis of o-isopropyl substituted phenolic and benzyl alcoholic compounds are described.
关键词 A NEW method FOR SYNTHESIS OF O-ISOPROPYL SUBSTITUTED AROMATIC compoundS
下载PDF
Effect of Different Drying Methods on the Volatile Compounds Jinmudan Oolong Tea 被引量:2
10
作者 Hui-Jing Xu Ying Wu +3 位作者 Qing Wei Fei-Long Cui Jing Zhu Ling-Yun Zhang 《茶叶》 2013年第4期362-369,共8页
Jinmudan,a new tea variety from Fujian Province has an excellent quality with a unique aroma like magnolia frogrance.To monitor the changes in the tea volatile compounds during the Jinmudan Oolong tea manufacturing(dr... Jinmudan,a new tea variety from Fujian Province has an excellent quality with a unique aroma like magnolia frogrance.To monitor the changes in the tea volatile compounds during the Jinmudan Oolong tea manufacturing(drying) process,the volatiles of tea samples were extracted and analyzed.Characteristic volatile compounds in Jinmudan Oolong tea were nerolidol,α-farnesene,linolenic acid,palmitic acid,indole,phenylacetaldehyde,cisjasmone,β-phenylethanol,etc.The content of nerolidol was the highest in four tested samples.The composition of the volatile compounds in microwave drying sample was simple,but its concentration was high,in which the main volatile compounds were alcohols and esters.The processing with combination of traditional drying craft and modern aroma-improvement technique could obviously improve the tea aroma,especially in level of epoxy linalool and jasmine lactone. 展开更多
关键词 挥发性化合物 干燥方法 乌龙茶 茶叶香气 橙花叔醇 茶叶品种 苯基乙醇 测试样本
下载PDF
A New Method for the Preparation of Substituted Benzil Compounds from Substituted Benzoin Compounds
11
《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期321-321,共1页
关键词 A New method for the Preparation of Substituted Benzil compounds from Substituted Benzoin compounds
下载PDF
Mobile Equilibrium Method for Determining Composition and Stability Constant of Coordination Compounds of the Form M_mR_n
12
作者 周执明 毛东森 叶存孝 《Journal of Rare Earths》 SCIE EI CAS CSCD 1997年第3期57-60,共4页
A new method is proposed for determining the composition and stability constant of coordination compounds of the form M m R n ; it can be used to differentiate mono and poly nuclear coordination compounds. ... A new method is proposed for determining the composition and stability constant of coordination compounds of the form M m R n ; it can be used to differentiate mono and poly nuclear coordination compounds. The equation derived is lg( A i/(A max - A i) m)=n lg c′ R+lg( m·β(c M/A max ) ( m -1) ). The method is based on Bent French limited logarithm method. The demonstration of the proposed method has yielded correct results for Sc 3+ chlorophosphonazo Ⅲ system and Fe 3+ Chromazurol S system. 展开更多
关键词 Rare earths Mobile equilibrium method Polynuclear coordination compounds COMPOSITION Stability constant
下载PDF
A Mapping Method of Using the Compound Use Cases to Generate User Interface
13
作者 Bingbing Xia Yue Zhang 《Open Journal of Applied Sciences》 2012年第3期180-183,共4页
To support the requirement analysis of the user interfaces and the auto generation of the final user interfaces, we should improve the traditional modeling method which centered on the system and the implementation, a... To support the requirement analysis of the user interfaces and the auto generation of the final user interfaces, we should improve the traditional modeling method which centered on the system and the implementation, and turn to use the modeling method which centered on the usage and the user. The compound use cases describe the system function from the user point of view. Based on the compound use cases, we can generate the final user interfaces. 展开更多
关键词 compound Use CASES USER INTERFACES Modeling method
下载PDF
Synthesis of carbon nanotubes by catalytic pyrolysis method with Feitknecht compound as precursor of NiZnAl catalyst
14
作者 Yan Xiaoqi Liu Quanrun +3 位作者 Zhang Songlin Zhang Kun Chen Jiuling Li Yongdan 《合成化学》 CAS CSCD 2004年第z1期130-130,共1页
关键词 carbon nanotubes Feitknecht compound nickel-zinc-alumina catalyst catalyticpyrolysis method
下载PDF
Validation for Microbial Limit Test Method of Compound Yu E Nose Drops
15
作者 Renhui YANG Peixue CAO +1 位作者 Zhen ZENG Xiangling QU 《Agricultural Biotechnology》 CAS 2019年第5期125-128,共4页
[Objectives] This study was conducted to establish a method for microbial limit test of Compound Yu E Nose Drops.[Methods] According to the Chinese Pharmacopoei (General Rules in the fourth part of the 2015 edition),t... [Objectives] This study was conducted to establish a method for microbial limit test of Compound Yu E Nose Drops.[Methods] According to the Chinese Pharmacopoei (General Rules in the fourth part of the 2015 edition),the microbial limit test method for Compound Yu E Nose Drops was verified.[Results] Compound Yu E Nose Drops has a strong inhibitory effect on Staphylococcus aureus and Bacillus subtilis,and the inhibitory activity was significantly eliminated after increasing the diluent (1∶ 20).The recoveries were all in the range of 0.5-2.0 when the total quantities of aerobic microbes were determined by the dilution method (1∶ 20).When the total quantities of mould and yeast were determined by the conventional method,the recoveries were both in the range of 0.5-2.0.When examining control bacteria,Escherichia coli,S.aureus and Pseudomonas aeruginosa can all be detected in the test groups by the test liquid dilution method.[Conclusions] For Compound Yu E Nose Drops,the total quantities of aerobic microbe can be counted by the dilution method;the quantities of mould and yeast can be examined by the conventional plate method;and the conventional method can be used for control microbe examination. 展开更多
关键词 compound Yu E NOSE DROPS MICROBIAL LIMIT test DILUTION method
下载PDF
加工方式对大豆油中挥发性物质的影响
16
作者 程建军 王兆华 +3 位作者 于殿宇 张赫 尤美月 潘明喆 《中国食品学报》 EI CAS CSCD 北大核心 2024年第2期248-259,共12页
为探究加工方式对大豆油风味物质的影响,采用电子鼻与顶空固相微萃取-气相色谱-质谱联用相结合的方法分析浸提、热榨和冷榨3种方式加工的大豆油挥发性物质的差异。结果表明:在3种大豆油样品中共检出86种挥发性物质,其中浸提油53种,热榨... 为探究加工方式对大豆油风味物质的影响,采用电子鼻与顶空固相微萃取-气相色谱-质谱联用相结合的方法分析浸提、热榨和冷榨3种方式加工的大豆油挥发性物质的差异。结果表明:在3种大豆油样品中共检出86种挥发性物质,其中浸提油53种,热榨油54种,冷榨油45种,主要包括醛类、醇类、酮类、酸类、酯类、萜烯类、杂环类(呋喃和吡嗪)以及烃类等化合物。在3种大豆油中检出相同的挥发性物质有24种。主成分分析和层次聚类分析结果表明加工方式对大豆油风味的影响较大。采用气味活度值(OAV)判定3种大豆油样品的关键风味物质,浸提油中检出关键风味物质15种,以3-壬烯-2-酮等物质为主,使浸提油具有浆果风味。热榨油中检出关键风味物质16种,其中2,5-二甲基吡嗪等杂环类物质使热榨油具有独特的烘焙风味。冷榨油中检出12种关键风味物质,以(E,E)-2,4-庚二烯醛等醛类物质为主,使冷榨油具有天然油脂风味。偏最小二乘回归分析表明电子鼻与气相色谱-质谱联用的检测结果间存在较好相关性。 展开更多
关键词 气相色谱-质谱联用法(GC-MS) 电子鼻 大豆油 加工方式 风味物质
下载PDF
3种不同熟化方式对彩色马铃薯挥发性风味物质组成的影响
17
作者 苏艳玲 张谨华 冯雅蓉 《粮食与油脂》 北大核心 2024年第1期15-18,49,共5页
采用气相色谱-离子迁移谱联用仪(GC-IMS)分析在不同熟化方式下彩色马铃薯的挥发性风味物质组成。结果表明:从3种不同熟化方式的彩色马铃薯样品中定性鉴定出挥发性有机物质共有52种,其中醛类物质的种类和相对含量均最高,表明醛类物质对... 采用气相色谱-离子迁移谱联用仪(GC-IMS)分析在不同熟化方式下彩色马铃薯的挥发性风味物质组成。结果表明:从3种不同熟化方式的彩色马铃薯样品中定性鉴定出挥发性有机物质共有52种,其中醛类物质的种类和相对含量均最高,表明醛类物质对马铃薯香味的呈现起主要作用。不同熟化方式对彩色马铃薯挥发性物质的组成及含量存在一定的差异,且不同颜色的马铃薯在同一种熟化方式下,其挥发性物质含量也表现出差异。在蒸制的彩色马铃薯中挥发性风味物质含量较低,在烤制和油炸的彩色马铃薯中风味物质含量较高。挥发性成分的种类和含量可以作为区分彩色马铃薯不同熟化方式的重要特征指标。 展开更多
关键词 彩色马铃薯 熟化方式 挥发性风味物质
下载PDF
复合助剂对低温喷雾干燥蓝靛果粉理化性质的影响 被引量:1
18
作者 郑先哲 鲁天麟 +5 位作者 陈启明 张雨涵 沈柳杨 付科森 朱海辉 柏才宇 《农业工程学报》 EI CAS CSCD 北大核心 2024年第2期93-106,共14页
为保证低温喷雾干燥后蓝靛果粉品质,采用黄金分割法研究复合助剂(麦芽糊精、β-环糊精和乳清蛋白)对喷雾干燥蓝靛果粉理化性质的影响,分析低温进风温度(50~90℃)对蓝靛果粉花青素保留率、集粉率和含水率的影响规律。结果表明,在麦芽糊... 为保证低温喷雾干燥后蓝靛果粉品质,采用黄金分割法研究复合助剂(麦芽糊精、β-环糊精和乳清蛋白)对喷雾干燥蓝靛果粉理化性质的影响,分析低温进风温度(50~90℃)对蓝靛果粉花青素保留率、集粉率和含水率的影响规律。结果表明,在麦芽糊精、β-环糊精的质量比例为85.4%、14.6%时,集粉率高达37.96%;随进料溶液中麦芽糊精质量比例增加,蓝靛果粉玻璃化转变温度、水溶性指数、堆积密度、亮度L^(*)值、红度a^(*)值和色差值ΔE呈增加趋势,含水率、花青素含量和黄度b^(*)值呈下降趋势;在麦芽糊精、β-环糊精和乳清蛋白质量比例为72.9%、12.5%、14.6%时,集粉率达到最高(40.11%);随料液中乳清蛋白质量比例增加,蓝靛果粉含水率、花青素含量呈上升趋势,其玻璃化转变温度、水溶性指数、亮度L^(*)值、红度a^(*)值、黄度b^(*)值和色差值ΔE等指标呈下降趋势;复合助剂显著提高蓝靛果粉集粉率(P<0.05),对其中的花青素起到较强保护作用,其含水率、水溶性指数、堆积密度等理化指标均接近于最优水平。低温喷雾干燥研究发现,随进风温度上升,集粉率和含水率呈负相关,在进风温度90℃时,集粉率最高的配方中可实现较高花青素保留率(89.94%)。低频核磁共振波谱以及质子密度图像信息分析表明,加入的助剂与蓝靛果果汁中水分通过氢键、静电结合力和疏水作用等分子间作用力,形成稳定性高水合物、增强液滴聚结抵抗力,提高料液玻璃态转换温度,从而实现高集粉率和高花青素保留率的蓝靛果果粉低温喷雾干燥;红外光谱分析表明,复合助剂可在蓝靛果果粉中形成分子间氢键,并对花青素等活性物质进行固定包埋保护。研究结果可为蓝靛果粉喷雾干燥加工生产提供理论支撑和参考依据。 展开更多
关键词 干燥 理化特性 低温喷雾干燥 复合助剂 蓝靛果 黄金分割法 花青素 核磁共振
下载PDF
镁熔体净化技术的研究进展
19
作者 余镕 田阳 +3 位作者 杨斌 徐宝强 梁栋 王立鹏 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第1期229-253,共25页
镁作为新兴轻质材料在汽车、3C和航空航天领域的应用逐渐普及,伴随行业节能减排的要求提升以及材料行业的迭代更新,镁及其合金所涉及的产业领域将会进一步扩大。而镁及其合金在铸造与变形加工前,镁熔体纯净度会对其性能产生巨大影响,如... 镁作为新兴轻质材料在汽车、3C和航空航天领域的应用逐渐普及,伴随行业节能减排的要求提升以及材料行业的迭代更新,镁及其合金所涉及的产业领域将会进一步扩大。而镁及其合金在铸造与变形加工前,镁熔体纯净度会对其性能产生巨大影响,如熔体纯净度低会显著降低合金的抗拉强度、伸长率等力学性能,导致合金出现炸裂、破损现象。为此,镁熔体的高效除气除杂净化技术成为研究热点。镁熔体净化作为镁熔炼过程中的重要环节,一直是科研工作者不断改进优化的研究课题。本文在简要介绍镁熔体中夹杂物来源的基础上,归纳了适用于镁熔体的熔剂净化、无熔剂净化、复合净化法及其净化效果,且对真空蒸馏法净化镁熔体的相关研究进行了探讨,系统综述了镁熔体净化技术研究进展,展望了该技术的未来研究方向。 展开更多
关键词 镁熔体 夹杂物 熔剂净化法 无熔剂净化法 复合净化法
下载PDF
发酵肉制品中的特征风味与微生物之间的关系研究进展 被引量:2
20
作者 张鹏 赵金山 +1 位作者 臧金红 彭传涛 《食品工业科技》 CAS 北大核心 2024年第2期380-391,共12页
发酵肉制品是指在自然或者人工的控制条件下,以新鲜的肉类为原料,通过微生物或酶的发酵作用制成的一类产品。发酵肉制品中特征风味物质种类繁多,其中主要有酯类、醛类、醇类、酸类以及游离氨基酸等。由于消费者对发酵肉制品风味品质要... 发酵肉制品是指在自然或者人工的控制条件下,以新鲜的肉类为原料,通过微生物或酶的发酵作用制成的一类产品。发酵肉制品中特征风味物质种类繁多,其中主要有酯类、醛类、醇类、酸类以及游离氨基酸等。由于消费者对发酵肉制品风味品质要求的提高,风味物质的控制已经成为提升发酵肉制品品质的关键指标之一。发酵肉制品中的部分微生物特别是乳酸菌、酵母菌和葡萄球菌促进了肉制品中碳水化合物、蛋白质和脂肪的分解,从而促进发酵肉制品独特风味的形成。本文详细介绍了国内外不同发酵肉制品中的主要风味物质、风味形成途径和检测方法,进一步归纳总结了能够产生这些风味物质的关键微生物以及产风味物质的微生物筛选方法,以期为后续发酵肉制品风味品质的提升提供参考。 展开更多
关键词 发酵肉制品 特征风味物质 微生物 微生物筛选方法
下载PDF
上一页 1 2 149 下一页 到第
使用帮助 返回顶部