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Hypertonic stimulation induces synthesis and release of glutamate in cultured rat hypothalamic astrocytes and C6 cells 被引量:1
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作者 曹荣 江山 +3 位作者 段丽 熊鹰飞 高蓓 饶志仁 《Neuroscience Bulletin》 SCIE CAS CSCD 2008年第6期359-366,共8页
Objective To investigate whether hypertonic saline (HS) can induce the synthesis and release of glutamate in cultured hypothalamic astrocytes or C6 cell line. Methods Astrocytes were isolated, cultured, purified and... Objective To investigate whether hypertonic saline (HS) can induce the synthesis and release of glutamate in cultured hypothalamic astrocytes or C6 cell line. Methods Astrocytes were isolated, cultured, purified and identified from the hypothalamus of newborn rat (1 day). The astrocytes were randomly divided into five groups: isotonic (IS) and HS groups, astrocytes were incubated by IS and HS (320 mosM NaCl) medium, respectively, for 1, 3, 5, 10 or 15 rain; carbenoxolone (CBX) +IS and CBX+HS groups, astrocytes were pre-treated with CBX (100 mmol/L) for 1 h at 37℃ in a 5% CO2 / 95% atmosphere, then removed to IS and HS medium, respectively, for 1, 3, 5, 10 or 15 min; Ca2++HS group, astrocytes were pre-incubated with Ca2+ (1 000 μmol/L) for 1 h at 37℃ in a 5% CO2 / 95% atmosphere, followed by a wash with isotonic FBS/DMEM, and then removed to hypertonic saline for 1, 3, 5, 10 or 15 min. The media of five groups were collected to analyze the medium glutamate concentration with high performance liquid chromatography. The astrocytes were fixed and double immunofluorescent stained with anti-glial fibrillary acidic protein (GFAP) and anti-glutamate. The C6 cells were divided into four groups: IS, HS, CBX+IS and CBX+HS groups, and used for quantitative measurement of glutamate in cells by flow cytometry (FCM). Results (1) Anti-GFAP immunofluorescent signal revealed no significant difference among various time points in each group, or among the five groups. (2) The anti-glutamate immunofluorescent signal was increased in HS group and peaked at 5 min, and decreased and returned to the level of IS group at 15 rain (P 〈 0.01 vs the 5 min of HS group). In CBX+HS group, the glutamate intensity was higher than that in CBX+IS and HS groups. (3) The medium glutamate concentration had no change after treatment with HS for 1 and 3 min, while increased markedly after treatment for 5 min to 15 min (P 〈 0.01 vs 1 min and 3 min). On the contrary, the medium glutamate concentrations in the CBX+HS or Ca2++HS group were significant lower than that in the HS group (P 〈 0.01). (4) FCM showed HS and CBX+HS induced glutamate increase in C6 cells. Conclusion HS induced cultured rat hypothalamic astrocytes or C6 cells to synthesize and release glutamate; CBX could block glutamate release, but could not disrupt glutamate synthesis. 展开更多
关键词 ASTROCYTES hypertonic stimulation CARBENOXOLONE connexin 43 high performance liquid chromatography immu-nofluorescent stain RAT
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Relationship Between Leaf Structure and Aloin Content in Six Species of Aloe L. 被引量:12
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作者 李景原 王太霞 +1 位作者 沈宗根 胡正海 《Acta Botanica Sinica》 CSCD 2003年第5期594-600,共7页
The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscop... The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscope. Results showed that all leaves consisted of epidermis, chlorenchyma, aquiferous tissue and vascular bundles. The leaves had the xeromorphic characteristics, including thickened epidermal cell wall, thickened cuticle, sunken stomata and well-developed aquiferous tissue. With the exception of thus, there were remarkable differences in leaf structure among the six species. The chlorenchyma cells were similar to palisade tissues in Aloe arborescens Mill. and A. mutabilis Pillans, but isodiametric in A. vera L., A. vera L. var. chinensis Berg., A. saponaria Hawer and A. greenii Bali. A. arborescens, A. mutabilis, A. very and A. vera var. chinensis included large parenchymatous cells at the vascular bundles, whereas no such cells were observed at the vascular bundles of A. saponaria and A. greenii. In A. arborescens, A. mutabilis and A. vera, the aquiferous tissue sheaths were present and composed of a layer of small parenchymatous cells without chloroplasts around the aquiferous tissue. While there were no aquiferous tissue sheaths in A. vera var. chinensis, A. saponaria and A. greenii. The HPLC revealed that the content of aloin was high in A. arborescens, low in A. vera, and very low in A. saponaria among the six species. The fluorescent microscopy showed that the yellow-green globule only appeared in the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath, but not in the chlorenchyma and aquiferous tissue. Consequently, the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath were the storage location of aloin. They were positively correlated with the content of aloin. 展开更多
关键词 ALOE leaf structure aloin content high performance liquid chromatography (HPLC) fluorescent microscope semi-thin section
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A High-Performance Silicon Electro-Optic Phase Modulator with a Triple MOS Capacitor 被引量:2
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作者 黄北举 陈弘达 +2 位作者 刘金彬 顾明 刘海军 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第12期2089-2093,共5页
We propose and analyze a novel Si-based electro-optic modulator with an improved metal-oxide-semiconductor (MOS) capacitor configuration integrated into silicon-on-insulator (SOl). Three gate-oxide layers embedded... We propose and analyze a novel Si-based electro-optic modulator with an improved metal-oxide-semiconductor (MOS) capacitor configuration integrated into silicon-on-insulator (SOl). Three gate-oxide layers embedded in the silicon waveguide constitute a triple MOS capacitor structure, which boosts the modulation efficiency compared with a single MOS capacitor. The simulation results demonstrate that the Vπ Lπ product is 2. 4V · cm. The rise time and fall time of the proposed device are calculated to be 80 and 40ps from the transient response curve, respectively,indicating a bandwidth of 8GHz. The phase shift efficiency and bandwidth can be enhanced by rib width scaling. 展开更多
关键词 carrier accumulation plasma dispersion effect electro-optic phase modulator METAL-OXIDE-SEMICONDUCTOR optoelectronic integrated circuit
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Primary Comments on Chemotaxonomy of Paris spp. Based on Saponins Analysis 被引量:6
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作者 黄芸 王强 崔力剑 《Journal of Chinese Pharmaceutical Sciences》 CAS 2005年第3期176-180,共5页
Aim The several species of the genus Paris called "Chonglou" are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Pa... Aim The several species of the genus Paris called "Chonglou" are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Paris and discussed their relations. Methods We detected the contents of 11 steroidal saponins in Paris samples with a Kromasel C18 ( 150 mm× 4.6 mm ID, 5μm) column which was subjected to gradient elution with acetonitrile-water (30:70- 60:40, V/V) at a flow rate of 1 mL· min^-1 by HPLC-ELSD and established chemical cluster tree using SPSS 11 software. Results All the samples could be separated and calibration curves of 11 saponins were prepared. We successfully detected the contents of 11 steroidal saponins in 14 Paris spp. in 30 min. The recovery for the assay of saponins was between 95 % and 97 %. The RSD of precision of 11 saponins and stability of samples were below 3 %. Chemical phylogenetic tree based on saponin contents indicated that 17 samples of Paris spp. clustered separately. Conclusion The established method is accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in Paris spp.. The chemical phylogenetic tree is in accordance with Takhtajian classical taxonomy. 展开更多
关键词 PARIS steroidal saponin cluster analysis HPLC-ELSD
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Determination of fleroxacin in human plasma by HPLC with fluorescence detection and the pharmacokinetic study
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作者 方增军 张斌 孙德清 《Journal of Chinese Pharmaceutical Sciences》 CAS 2007年第4期257-261,共5页
Aim To develop a sensitive and accurate HPLC method for the determination of fleroxacin in human plasma, and study its pharmacokinetics in healthy subjects. Methods The analytes were isolated fi'om plasma by simple p... Aim To develop a sensitive and accurate HPLC method for the determination of fleroxacin in human plasma, and study its pharmacokinetics in healthy subjects. Methods The analytes were isolated fi'om plasma by simple protein precipitation with methanol, separated on a Diamonsil C18 column by isocratic elution with the mobile phase consisted of 1% triethylamine at pH 4.8 (adjusted with phosphoric acid) and acetonitrile (80/20, V/V) at a flow rate of 1.0 mL.min^-1 and analyzed by fluorescence detector with an excitation at 290 nm and emission 458 nm. The pharmacokinetic study of fleroxacin was performed according to a double period crossover design. Results The weighted (1/x) calibration curve was linear over the plasma concentration range of 0.025 - 8.00 μg.mL^-1 The inter- and intra-day precisions (RSD/%) were no more than 5.16%, and the method accuracies and extraction recoveries at three concentrations ranged firom 99.1% to 100.9%, and 86.7% to 92.0%, respectively. Following oral administration at a dose of 400 mg fleroxacin, the main pharmacokinetic parameters for test and reference capsules were Cmax5.08 ± 0.78 and 5.38 ± 1.40 μg.mL^-1, tmax 1.72 ±0.79 and 1.82 ± 0.78 h, t1/2 11.68 ± 1.27 and 11.38 ± 1.51 h^-1, AUC0-∞ 78.44 ± 11.44 and 76.53 ± 13.24 μg.mL^-1.h, respectively. Conclusion The method is sensitive and accurate, and suitable for human pharmacokinetic study of fleroxacin. 展开更多
关键词 FLEROXACIN HPLC FLUORESCENCE PHARMACOKINETICS
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屏幕校调功能中调整色温的意义
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作者 吕敏志 《电子测试》 1999年第11期24-24,共1页
A 1.色温(C o l o rTemperature)在物理学上具备相当严谨的定义,表示的单位为绝对温度K(Kelvin)。它是指标准黑体(black body)在加热后,辐射频率(可对应所表现出的颜色)与温度之间具有函数的关系,而表现出来的形式就是随着温度的上升,... A 1.色温(C o l o rTemperature)在物理学上具备相当严谨的定义,表示的单位为绝对温度K(Kelvin)。它是指标准黑体(black body)在加热后,辐射频率(可对应所表现出的颜色)与温度之间具有函数的关系,而表现出来的形式就是随着温度的上升,黑体光色会由深红逐渐变为蓝白。若某光源的光色与黑体光色相同时,两者便具备相同的色温值。因此就其功用来说,色温可视为是一种量化描述颜色的方法。以一般认定的色温值来说,当其低于3000K时,光色便有偏红的趋势,且给人较为温暖的感觉;当色温高于5500K时,光色便有偏蓝的趋势,给予人的感觉则较为清冷。若表现在电脑屏幕上,也是相同的道理,只不过由于每个人对颜色的喜爱与接受程度不同,在感觉上便有所差异。因此即使在相同环境下,每个人认定的合适色温标准也多不会相同。颜色产生的来源可大致分为光线反射、透射,与自体发光等数种方式。而屏幕发光的方式即属于自体发光,与一般反射或透射的方式皆不相同,因此在调整屏幕色温时。 展开更多
关键词 调整色温 调制解调器 光色相 电脑屏幕 颜色 黑体 每个人 辐射频率 个人认定
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Determination of Astragaloside IV in Yupingfeng Oral Solution by HPLC-ELSD Method
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作者 王建舫 张倩 穆祥 《Agricultural Science & Technology》 CAS 2015年第2期197-199,共3页
[Objective] This study aimed to establish a method for determining the content of Astragaloside IV in Yupingfeng oral solution.[Method] The HPLC-ELSD method was adopted.The chromatographic column was Venusil MP(4.6 m... [Objective] This study aimed to establish a method for determining the content of Astragaloside IV in Yupingfeng oral solution.[Method] The HPLC-ELSD method was adopted.The chromatographic column was Venusil MP(4.6 mm × 150 mm,5 μm).The mobile phase was acetonitrile-water(35∶65).The ELSD evaporator tube temperature was 65 ℃.N2 was used as the carrier gas(pressure,30 psi).[Result] When the content of Astragaloside IV ranged from 0.5 to 5.0 μg,the Astragaloside IV content showed a good linear relationship with peak area(r=0.999,n=6).The average recovery was 96.36%,and the RSD was 2.46%.[Conclusion] This method is accurate and reliable,and can be applied in the quality control of Yupingfeng oral solution. 展开更多
关键词 HPLC ELSD Yupingfeng oral solution Astragaloside IV
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Determination of Diphenytriazol (DL111-IT) in Rabbit Plasma by High-Performance Liquid Chromatography with Fluorescence Detection
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作者 何敏 姚彤炜 《Journal of Chinese Pharmaceutical Sciences》 CAS 2005年第1期56-60,共5页
Aim To develop an HPLC method with fluorescence detection for the assay ofDL111-IT in rabbit plasma. Methods DL111-IT and internal standard glybenzcyclamide in rabbit plasmawere extracted with chloroform. The determin... Aim To develop an HPLC method with fluorescence detection for the assay ofDL111-IT in rabbit plasma. Methods DL111-IT and internal standard glybenzcyclamide in rabbit plasmawere extracted with chloroform. The determination was performed on a Diamonsil ODS-C_(18) column(150 mm x 4.6 mm, 5 μm) with a mobile phase of acetonitrile and 0.025 mol·L^(-1) diammoniumhydrogen phosphate buffer (pH 5.0, adjusted by phosphoric acid) (60:40, V/V) at a flow-rate of 1.0mL·min^(-1) . Fluorescence detector was operated at excitation wavelength of 250 nm and emissionwavelength of 332 nm. Results The calibration curve in plasma was linear from 1.00 - 20.00ng·mL^(-1) ( r = 0.999 6, n = 5). The method afforded average extracting recoveries of 85.3% ±1.3%, 84.9% ± 2.7% and 85.8% ± 1.8%, and the average method recoveries were 99.5% ±0.4%, 102.1%± 1.8% and 101.3% ± 2.4% for the high (20.00 ng·mL^(-1)) , middle (10.00 ng·mL^(-1)) and low (1.00 ng·mL^(-1)) check samples, respectively. The intra-day (n = 5) and inter-day (n = 5) precisions(RSD) were less than 3.0% and 7.0%, respectively. The limit of detection and quantitation for themethod were 0.3 ng·mL^(-1) (S/N = 3) and 1 ng·mL^(-1) (S/N = 10, RSD<7.0%) plasma sample,respectively. Conclusion The developed method was accurate, sensitive, simple and could be used forpharmacokinetic study of DL111- IT. 展开更多
关键词 DIPHENYTRIAZOL contragestazol DL111-IT HPLC fluorescence detection pharmaco-kinetics glybenzcyclamide
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Preparation of Conjugated Linoleic Acid and Identification of Its Isomers 被引量:9
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作者 郭诤 张根旺 孙彦 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第2期130-135,共6页
Conjugated linoleic acid (CLA) is a kind of fatty acid with physiological activities and potential application prospect. A synthesis method of conjugated linoleic acid and a purification technology were studied. CLA w... Conjugated linoleic acid (CLA) is a kind of fatty acid with physiological activities and potential application prospect. A synthesis method of conjugated linoleic acid and a purification technology were studied. CLA was prepared and purified by urea-complexation and conjugation using safflower oil as raw material. The purity of CLA and total recovery of the product was more than 95% and 48%, respectively. The main isomers produced in alkali-catalyzed conjugation were identified by gas chromatography (GC) linked to mass spectrometry (MS) and Fourier transform infrared spectroscopy (FTIR). The total amount of the two main isomers (9cis, 11trons-and 10trans, 12cis-CLA) determined by GC was more than 90% of the product. 展开更多
关键词 linoleic acid conjugated linoleic acid urea-complexation alkali-catalyzed conjugation IDENTIFICATION safflower oil
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Moments and Mean First—Passage Time of Parabolic—Bistable Potential System Driven by Colored Noise 被引量:2
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作者 LIANGGui-Yun CAOLi 等 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第2期155-160,共6页
A parabolic-bistable potential system driven by colored noise is studied. The exact analytical expressions of the stationary probability distribution (SPD) and the moments of the system are derived. Furthermore, the m... A parabolic-bistable potential system driven by colored noise is studied. The exact analytical expressions of the stationary probability distribution (SPD) and the moments of the system are derived. Furthermore, the mean first-passage time is calculated by the use of two approximate methods, respectively. It is found that (i) the double peaks of SPD are rubbed-down into a flat single peak with the increasing of noise intensity; (ii) a minimum occurs on the curve of the second-order moment of the system vs. noise intensity at the point ; (iii) the results obtained by our approximate approach are in good agreement with the numerical calculations for either small or large correlation time , while the conventional steepest descent approximation leads to poor results. 展开更多
关键词 MOMENTS mean first-passage time colored noise parabolic-bistable potential
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Extraction of essential oil from shaddock peel and analysis of its components by gas chromatography-mass spectrometry 被引量:2
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作者 周尽花 周春山 +1 位作者 蒋新宇 谢练武 《Journal of Central South University of Technology》 EI 2006年第1期44-48,共5页
Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation ... Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation and direct steam distillation method. Among their composition, the main components are terpene compounds, which account for 93.926% (mass fraction, the same below) and 85.843% of essential oils extracted from Shatian shaddock peel and Sweet shaddock peel, respectively. Although nootkatone is the major contributor of shaddock characteristic scent, and its contents are 1.069% and 1.749% of essential oils from Sweet shaddock peel and Shatian shaddock peel, respectively. The results show that squeeze-steam distillation gives higher yield and good quality of essential oil and the compositions of essential oils from two kinds of shaddock peels are different, but the main contributors of the shaddock scent are the same. 展开更多
关键词 essential oil Shatian shaddock Sweet shaddock gas chromatography - mass spectrometry nootkatone EXTRACTION
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Supercontinuum Generation Enhanced by Cross-phase Modulation in Dispersion-flattened and Decreasing Fiber 被引量:1
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作者 XUWen-cheng XUYong-zhao YUBing-tao CUIHu CHENYong-zhu LIUSong-hao 《Semiconductor Photonics and Technology》 CAS 2005年第2期116-121,共6页
Supercontinuum spectrum generation in a dispersion-flattened and decreasing fiber with two orthogonally polarized pulses was simulated and calculated. The research results indicated that the supercontinuum spectrum ge... Supercontinuum spectrum generation in a dispersion-flattened and decreasing fiber with two orthogonally polarized pulses was simulated and calculated. The research results indicated that the supercontinuum spectrum generated by two orthogonally polarized pulses is wider and flatter than that generated by single polarized pulse due to cross-phase modulation. The cross-phase modulation effect can enhance the supercontinuum spectrum generation. When the pump power of the input pulse is lower, the enhancement of supercontinuum spectrum generation by cross-phase modulation effect is more significant. 展开更多
关键词 fiber optics supercontinuum spectrum dispersion-flattened and decreasingfiber cross-phase modulation soliton trapping
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Determination of constituents of essential oil from Angelica sinensis by gas chromatographymass spectrometry 被引量:13
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作者 吴名剑 孙贤军 +3 位作者 戴云辉 郭方遒 黄兰芳 梁逸曾 《Journal of Central South University of Technology》 EI 2005年第4期430-436,共7页
Gas chromatographymass spectrometry (GC-MS) coupled with chemometric resolution upon two- dimensional data was employed to analyze the constituents of essential oils of Angelica sinensis. Constituents in essential oil... Gas chromatographymass spectrometry (GC-MS) coupled with chemometric resolution upon two- dimensional data was employed to analyze the constituents of essential oils of Angelica sinensis. Constituents in essential oils of Angelica sinensis root were identified by GC-MS with the help of subwindow factor analysis (SFA) method resolving two-dimensional original data into mass spectra and chromatograms. 76 of 97 separated constituents in essential oil of Angelica sinensis root were identified and quantified, and they account for about 91.36% of the total content. The results show that ligustilide, butylene phthalide, 2-methoxy-4-vinylphenol, carvacrol, allo-ocimene,2,6,6-trimethylbicyclo-[3,1,1]hept-2-ene are the main constituents in essential oil of Angelica sinensis root. 展开更多
关键词 Angelica sinensis CHEMOMETRICS gas chromatography- mass spectrometry subwindow factor analysis
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First—Order—Like Transition for Dispersive Optical Bistability
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作者 HEYing ZHUShi-Qun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第1期57-62,共6页
The first-order-like phase transition (FOLT) in the dispersive optical bistability is investigated when the fluctuation in the incident light field is considered as colored noise. A unified colored-noise approximation... The first-order-like phase transition (FOLT) in the dispersive optical bistability is investigated when the fluctuation in the incident light field is considered as colored noise. A unified colored-noise approximation is applied to obtain the steady state distribution (SSD) when either the intensity or phase fluctuations of the incident field are included in the system. For intensity fluctuations only, the curve of SSD is changed from single extreme to two extremes, and then to three extremes. The colored nature of the noise can reduce the fluctuation in the system. However, for phase fluctuations only, the FOLT is mainly induced by the colored nature of the noise. The curve of SSD is changed from single extreme to three extremes directly. There is no FOLT existing for white noise. 展开更多
关键词 dispersive optical bistability first-order-like phase transition intensity fluctuation phase fluctuation
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Extraction,Isolation and Structural Characterization of Polysaccharides from a Red Alga Gloiopeltis furcata 被引量:3
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作者 YU Guangli HU Yannan YANG Bo ZHAO Xia WANG Peipei JI Guoli WU Jiandong GUAN Huashi 《Journal of Ocean University of China》 SCIE CAS 2010年第2期193-197,共5页
Three kinds of polysaccharides: GFW, GFH and GFA, were sequentially extracted from a red alga Gloiopeltisfurcata with 25℃ and 85℃ water, and 60℃ 4% NaOH water solution. Based on the defatted alga, the yields of th... Three kinds of polysaccharides: GFW, GFH and GFA, were sequentially extracted from a red alga Gloiopeltisfurcata with 25℃ and 85℃ water, and 60℃ 4% NaOH water solution. Based on the defatted alga, the yields of the polysaccharide were 57.9%, 2.5% and 2.6%, respectively. Their monosaccharide compositions, average molecular weights and structural characters were determined by gas chromatography (GC), high performance liquid chromatography (HPLC), fourier transform infrared spectroscopy (FTIR) or ^13C-NMR spectroscopy. The results showed that GFW, GFH and GFA were all composed of D-galactose (Gal) and 3,6-anhydro-L-galactose (AnG), and particularly GFA also contained xylose (Xyl). The average molecular weights of GFW, GFH and GFA were 22.6 kD, 26.5 kD and 49.8 kD, respectively, with the respective sulfate content 31.2%, 25.1% and 22.7%. The data of FTIR and ^13C-NMR confirmed the sulfate ester location at C6 ofgalactose. It is concluded that all the three polysaecharides extracted from Gloiopeltisfurcata were sulfated galactans, two being sulfated-agarose, and one being xylose-containing sulfated galactan. 展开更多
关键词 Gloiopeltisfurcata sulfated galactan EXTRACTION structural characterization
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Study of oxidization of coal–pitch by O_3 被引量:2
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作者 Wang Yaoling Chen Sishun +1 位作者 Ding Mingjie Xu Zhan 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第4期677-681,共5页
For the purpose of obtaining small molecular and oxygen-containing aromatic compounds, taking a toluene-extracted coal pitch as the research object, the oxidation of coal-pitch by ozone (03) in formic acid was studi... For the purpose of obtaining small molecular and oxygen-containing aromatic compounds, taking a toluene-extracted coal pitch as the research object, the oxidation of coal-pitch by ozone (03) in formic acid was studied. The coal-pitch sample and the oxidized pitch residue were characterized by elementary analysis and Fourier transform infrared spectroscopy (FTIR), while the small molecular products were analyzed by a gas chromatography-mass spectrometer (GC-MS). The results show that the highest oxygen content of oxidized coal pitch had been acquired at a reaction temperature of 50℃C, an 03 flow rate of 6300 mg/h and a reaction time of 4 h. Quite a lot of hydroxyls and carbonyls were introduced into the structure of the oxidized coal-pitch, while the small molecules produced mainly involve nonpolar aro- matic compounds, aromatic anhydride and quinone compounds. It is speculated that the mechanism is direct electrophilic oxidation in which the molecules of 03 directly attack the aromatic ring at its carbon atoms with high electron density, and then generate hydroxyl or carbonyl until the aromatic ring cracks. This study shows that 03 can make the fused aromatic ring of coal-pitch become oxidized and depoly- merized, and hence the ozonization of coal-pitch can be a potential method for obtaining oxygen- containing aromatic compounds. 展开更多
关键词 Study Coal-pitch Ozone oxidation Depolymerization
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Determination of Baicalin in Traditional Chinese Preparation by High Performance Liquid Chromatography with Chemiluminescence Detection 被引量:5
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作者 ErBaoLIU HongQingWEI XiuLiZHAO XiaoXiaLI FengXianJIANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第9期1067-1070,共4页
A new method for the determination of baicalin with HPLC-CL was developed. The method was based on the chemiluminescence reaction between KMnO4 and baicalin sensitized from HCHO. The linear range was 3.7?0-6~9.8?0-5... A new method for the determination of baicalin with HPLC-CL was developed. The method was based on the chemiluminescence reaction between KMnO4 and baicalin sensitized from HCHO. The linear range was 3.7?0-6~9.8?0-5 mol/L with detection limit of 1.7?0-6 mol/L and the relative standard deviation was 2.5 % (Cs=6.6?0-5 mol/L, n=5). The method has been applied to the determination of baicalin in oral administration, injection, Scutellariae radix and granules with good results. 展开更多
关键词 RP-HPLC chemiluminescence analysis baicalin.
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Optimizing the nickel boride layer thickness in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in glycerol oxidation 被引量:2
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作者 Steffen Cychy Sebastian Lechler +7 位作者 Zijian Huang Michael Braun Ann Cathrin Brix Peter Blümler Corina Andronescu Friederike Schmid Wolfgang Schuhmann Martin Muhler 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第12期2206-2215,共10页
The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The c... The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The continuously operated radial flow cell consisted of a borehole electrode positioned 50μm above an internal reflection element enabling operando FTIR spectroscopy.It is identified as a suitable tool for facile and reproducible screening of electrocatalysts under well-defined conditions,additionally providing access to the selectivities in complex reaction networks such as glycerol oxidation.The fast product identification by ATR-IR spectroscopy was validated by the more time-consuming quantitative HPLC analysis of the pumped electrolyte.High degrees of glycerol conversion were achieved under the applied laminar flow conditions using 0.1 M glycerol and 1 M KOH in water and a flow rate of 5μL min^(–1).Conversion and selectivity were found to depend on the catalyst loading,which determined the catalyst layer thickness and roughness.The highest loading of 210μg cm^(–2)resulted in 73%conversion and a higher formate selectivity of almost 80%,which is ascribed to longer residence times in rougher films favoring readsorption and C–C bond scission.The lowest loading of 13μg cm^(–2)was sufficient to reach 63%conversion,a lower formate selectivity of 60%,and,correspondingly,higher selectivities of C_(2)species such as glycolate amounting to 8%.Thus,only low catalyst loadings resulting in very thin films in the fewμm thickness range are suitable for reliable catalyst screening. 展开更多
关键词 Catalyst layer thicknes ELECTROCATALYST Nickel boride Operando ATR-IR High performance liquid CHROMATOGRAPHY Flow cell Thin film Anodic glycerol oxidation
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Analysis of Sucrose Esters with Long Acyl Chain by Coupling of HPLC-ELSD with ESI-MS System 被引量:5
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作者 朱金丽 汤艳峰 +1 位作者 李建华 张淑芬 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第6期1032-1037,共6页
The analysis of sucrose esters with long acyl chain by improved high performance liquid chromatographic method with evaporative light scattering detection (HPLC-ELSD) and electrospray ionization mass spectrum (ESI... The analysis of sucrose esters with long acyl chain by improved high performance liquid chromatographic method with evaporative light scattering detection (HPLC-ELSD) and electrospray ionization mass spectrum (ESI-MS) is investigated. The improved HPLC-ELSD method for the separation and quantitation of commercial and synthesized sucrose esters is described. Samples are analyzed by means of a reversed-phase (RP) HPLC using a Hypersil C8 column (250 mm× 4.6 mm, 5 μm particle size) with methanol-tetrahydrofuran (vo)ume ratio of 90 : 10) and water under gradientcondition as the mobile phase, in which the flow rate is 1.0 ml·min^-1 and the column temperature is set at 40℃. This procedure provides a complete separation and determination ot monoester, diester, triester and higher esters with different acyl chain lengths in each fraction by a single run, in combination with the ESI-MS technology. With this method, it is possible to determine the approximate compositions of monoto polyesters in one analysis and quantitate pure positional isomers precisely using an external standard method. It is found that the method of ESI-MS coupling with HPLC system for the analysis of sucrose esters is straight forward, rapid and inexpensive, and can be readily applied in synthesis, purification and structure studies. 展开更多
关键词 sucrose esters long acyl chain ANALYSIS high performance liquid chromatographic method with evaporative light scattering detection electrospray ionization mass spectrum
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Low Dynamic Range Solutions to the High Dynamic Range Imaging Problem
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作者 Shanmuganathan RAMAN Subhasis CHAUDHURI 《Journal of Measurement Science and Instrumentation》 CAS 2010年第1期32-36,共5页
While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capt... While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capturing a picture of a some which has both brightly and poorly illuminated regions. High Dynamic Range (HDR) imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images. Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range(LDR) images on common displays. This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images. It is assumed that there is no knowledge of camera response function and other camera settings. At last, it is explained how this task can be achieved effectively for static and dynamic scenes. 展开更多
关键词 computational photography HDR imaging digital compositing
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