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1,1’-联萘-2,2’-二酚-单-[(-)-孟基]碳酸酯旋光异构体的反相高效液相色谱分离及光学纯度测定 被引量:2
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作者 阮源萍 陈安齐 +2 位作者 刘文远 郑锦丽 黄培强 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2000年第6期803-807,共5页
采用反相高效液相色谱法分离了 1 ,1’-联萘 - 2 ,2’-二酚 -单 [(- ) -孟基 ]碳酸酯旋光异构体 .考察了这一对旋光化合物的反相高效液相色谱行为 .结果表明 ,C1 8及 C8柱和醇 /水流动相体系适合于这一对旋光异构体的分离 .进一步优化... 采用反相高效液相色谱法分离了 1 ,1’-联萘 - 2 ,2’-二酚 -单 [(- ) -孟基 ]碳酸酯旋光异构体 .考察了这一对旋光化合物的反相高效液相色谱行为 .结果表明 ,C1 8及 C8柱和醇 /水流动相体系适合于这一对旋光异构体的分离 .进一步优化了色谱分离条件 。 展开更多
关键词 反相高效液相色谱 旋光异构体 1 1’-联萘-2 2’-二酚--[(-)-孟基]碳酸
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酶催化合成高纯度甘油中碳酸单酯 被引量:8
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作者 吕栓锁 方云 苏亚芬 《精细化工》 EI CAS CSCD 北大核心 2004年第4期265-268,共4页
研究了无溶剂体系中脂肪酶LRI催化合成甘油中碳酸单酯(MG)。得到适宜的反应条件为:反应温度57℃,n(酸)∶n(甘油)=1∶1 1,加酶量100U/g(酸),甘油初始含水量w(H2O)=12%,封闭物系反应4h转敞开物系反应6h。产物中甘油中碳酸单酯质量分数w(MG... 研究了无溶剂体系中脂肪酶LRI催化合成甘油中碳酸单酯(MG)。得到适宜的反应条件为:反应温度57℃,n(酸)∶n(甘油)=1∶1 1,加酶量100U/g(酸),甘油初始含水量w(H2O)=12%,封闭物系反应4h转敞开物系反应6h。产物中甘油中碳酸单酯质量分数w(MG)=42 20%。将n(酸)∶n(甘油)降低至1∶9,反应时间缩短至4h,粗产物经脱甘油和脱酸处理,可获得高纯度甘油中碳酸单酯。纯化后产品中基本不含游离酸及甘油,其中甘油中碳酸单酯质量分数w(MG)=73 65%。过量加入的甘油全部可以回收利用,其平衡转化率降低不超过2%。 展开更多
关键词 脂肪酶 甘油中碳酸 酶催化合成
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碳酸单甲酯季铵盐在棉织物上的吸附性能研究
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作者 李健生 裴小丽 +1 位作者 余潇潇 刘学民 《中国洗涤用品工业》 2015年第2期56-60,共5页
考察了烷基三甲基碳酸单甲酯季铵盐在纯棉织物上的吸附行为,测定了不同温度下的吸附量,得到了等温吸附曲线,并根据热力学原理计算出吸附过程中的探究了吸附规律。研究发现,三种季铵盐在棉织物上的吸附大致符合langmuir吸附规律,吸附量... 考察了烷基三甲基碳酸单甲酯季铵盐在纯棉织物上的吸附行为,测定了不同温度下的吸附量,得到了等温吸附曲线,并根据热力学原理计算出吸附过程中的探究了吸附规律。研究发现,三种季铵盐在棉织物上的吸附大致符合langmuir吸附规律,吸附量随浓度的增加、迅速增大,在某一浓度达到吸附平衡;在织物上的吸附量随碳链的增加而增加、随温度的增大而降低。对吸附过程热力学的ΔG、ΔH和ΔS热力学分析印证了上述结论。 展开更多
关键词 表面活性剂 烷基碳酸甲酯季铵盐 紫外分光光度法 棉织物 吸附性能
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乙氧基化脂肪酸甲酯的性能及丙氧基化改性研究 被引量:9
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作者 陈健 方云 +1 位作者 杨澄宇 阮小云 《日用化学工业》 CAS CSCD 北大核心 2004年第2期80-83,共4页
以单碳酸或混合酸甲酯为原料,通过一步法乙氧基化反应合成了不同链长的脂肪酸和不同EO数的乙氧基化脂肪酸甲酯(EFME),测定了EFME的物化性能和应用性能。结果表明,EFME具有低成本、低泡等特殊优点,性能依赖EO加成数变化连续可调整,EFME... 以单碳酸或混合酸甲酯为原料,通过一步法乙氧基化反应合成了不同链长的脂肪酸和不同EO数的乙氧基化脂肪酸甲酯(EFME),测定了EFME的物化性能和应用性能。结果表明,EFME具有低成本、低泡等特殊优点,性能依赖EO加成数变化连续可调整,EFME中的封端甲基是导致其性能不同于AEO的最重要的结构因素。用PO对EFME进行化学改性,先加成PO的产品的起泡力更低、流变性更好,与不改性产品相比起泡力降为原先的29%;稳泡性降为原先的22%;黏度降低为原先的44%。说明PO位于分子的亲水端侧较处于疏水端侧对产品的泡沫性和流变性的影响程度更大,通过PO改性可以进一步开发EFME的新用途。 展开更多
关键词 乙氧基化脂肪酸甲酯 丙氧基化改性 单碳酸 混合酸甲酯 乙氧基化反应 非离子表面活性剂
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衍生化高效液相色谱法拆分1,1′-联萘-2,2′-二酚光学异构体 被引量:3
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作者 阮源萍 敖小平 +1 位作者 陈安齐 黄培强 《分析化学》 SCIE EI CAS CSCD 北大核心 2001年第12期1398-1401,共4页
以基碳酸酰氯作衍生化试剂 ,采用高效液相色谱拆分 1,1′ 联萘 2 ,2′ 二酚光学异构体。当采用LichrosorbSi 6 0 (4mm× 30 0mm ,5 μm)柱 ,紫外 2 75nm检测 ,正己烷 乙醇 (98.5 1.5 ,V V)为流动相 ,1,1′ 联萘 2 ,2′ 二酚... 以基碳酸酰氯作衍生化试剂 ,采用高效液相色谱拆分 1,1′ 联萘 2 ,2′ 二酚光学异构体。当采用LichrosorbSi 6 0 (4mm× 30 0mm ,5 μm)柱 ,紫外 2 75nm检测 ,正己烷 乙醇 (98.5 1.5 ,V V)为流动相 ,1,1′ 联萘 2 ,2′ 二酚单基碳酸酯的分离因子和分离度分别为 1.36 8、3.0 5 1;用正己烷 乙醚 (98.5 1.5 ,V V)为流动相 ,1,1′ 联萘 2 ,2′ 二酚双基碳酸酯的分离因子和分离度分别为 1.0 5 5、1.347。这一方法可简便。 展开更多
关键词 高效液相色谱 衍生化 1 1'-联萘-2 2’-二酚 联萘二酚Mong基碳酸 联萘二酚双Mong基碳酸 光学异构体 拆分
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Early calcium monocarboaluminate hydrate formation in cement paste:effect of polycarboxylate type admixture 被引量:2
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作者 蒋亚清 张思佳 +1 位作者 刘小艳 D.Damidot 《Journal of Southeast University(English Edition)》 EI CAS 2010年第4期574-577,共4页
Effects of polycarboxylate type admixture(PCA)on calcium monocarboaluminate hydrate(AFmc)formation in hydrated cement paste containing limestone filler(LF)are investigated by the Fourier transform infrared spect... Effects of polycarboxylate type admixture(PCA)on calcium monocarboaluminate hydrate(AFmc)formation in hydrated cement paste containing limestone filler(LF)are investigated by the Fourier transform infrared spectroscopy(FTIR),the scanning electron microscopy(SEM),the derivative thermogravimetric(DTG)analysis and the adsorption amount measurement.Experimental results indicate that AFmc forms during the initial hydration period of cement as early as 15 min.It is found that PCA accelerates the early age AFmc formation and enhances cement hydration by promoting C4AF hydration at the early age,and,as a consequence,the iron associated AFmc phase forms more readily.The phenomenon is not observed when PCA is replaced by a naphthalene formaldehyde sulphonate condensate water reducer.Compatibility between PCA and cement is modified due to the presence of AFmc along with ettringite(AFt),which results in a less adsorption amount of PCA on the surface of cement minerals.As a kind of high-range water reducer,PCA may be the preferred choice for concrete containing LF. 展开更多
关键词 cement high-range water reducer limestone ETTRINGITE calcium monocarboaluminate hydrate
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聚乙二醇(PEG-5000)对胰激肽释放酶化学修饰的初步研究 被引量:7
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作者 张继娟 吴梧桐 《药物生物技术》 CAS CSCD 2006年第6期409-412,共4页
以自制单甲氧基聚乙二醇琥珀酰亚胺碳酸酯对猪胰激肽释放酶进行化学修饰,修饰产物以super-dex G75凝胶色谱柱进行分离纯化。结果表明,修饰PPK分子质量增加,保留活性降低,对温度的耐受性加强,稳定性增加。
关键词 甲氧基聚乙二醇琥珀酰亚胺碳酸 猪胰激肽释放酶 化学修饰 分离纯化
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猪红细胞的体外双修饰及异源输血试验 被引量:1
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作者 贾杏林 芮小庆 +3 位作者 夏雨婷 汤辰旻 钟佳莲 朱锦涛 《动物医学进展》 CSCD 北大核心 2013年第2期114-117,共4页
为探讨表面抗原修饰后猪红细胞异源输血的可行性,采用α-半乳糖苷酶和单甲氧基聚乙二醇琥珀酰亚胺碳酸酯(mPEG-SC)对猪红细胞进行双修饰后,体外检测红细胞的渗透脆性,并进行配血试验和犬输血试验。观察输血前后犬的各项临床指标变化,并... 为探讨表面抗原修饰后猪红细胞异源输血的可行性,采用α-半乳糖苷酶和单甲氧基聚乙二醇琥珀酰亚胺碳酸酯(mPEG-SC)对猪红细胞进行双修饰后,体外检测红细胞的渗透脆性,并进行配血试验和犬输血试验。观察输血前后犬的各项临床指标变化,并对其进行血常规和尿常规的连续检测分析。结果表明,修饰红细胞渗透脆性降低,体外配血未出现凝集反应。输血后亦未引起明显的临床异常反应,血常规及尿常规正常。说明猪红细胞体外双修饰后进行首次异源输血具有可行性,可作为动物通用血源用于临床。 展开更多
关键词 猪红细胞 Α-半乳糖苷酶 甲氧基聚乙二醇琥珀酰亚胺碳酸 异源输血
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胰高血糖素样肽-1在乙醇中的聚乙二醇修饰 被引量:1
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作者 王友傲 翟艳琴 +2 位作者 雷建都 马光辉 苏志国 《过程工程学报》 CAS CSCD 北大核心 2010年第3期593-597,共5页
以乙醇为溶剂,单甲氧基聚乙二醇琥珀酰亚胺碳酸酯(mPEG-SC)为修饰剂,对胰高血糖素样肽-1(GLP-1)进行了修饰反应条件的优化,同时对单修饰产物Mono-PEG-GLP-1进行分离纯化,并考察了其体外稳定性和体内活性.得到的优化反应条件为:GLP-1浓度... 以乙醇为溶剂,单甲氧基聚乙二醇琥珀酰亚胺碳酸酯(mPEG-SC)为修饰剂,对胰高血糖素样肽-1(GLP-1)进行了修饰反应条件的优化,同时对单修饰产物Mono-PEG-GLP-1进行分离纯化,并考察了其体外稳定性和体内活性.得到的优化反应条件为:GLP-1浓度1mg/mL,mPEG-SC与GLP-1摩尔比1:1,37℃下反应24h,该产物最高转化率达77%.采用冷冻离心方式对Mono-PEG-GLP-1进行初步分离和浓缩,然后经反相液相色谱进一步高效纯化,纯度可达97%以上.体外实验表明,Mono-PEG-GLP-1在血清中具有更好的稳定性及更强的抗胰蛋白酶消化能力.体内动物实验表明,Mono-PEG-GLP-1具有更好的降血糖作用. 展开更多
关键词 胰高血糖素样肽-1 甲氧基聚乙二醇琥珀酰亚胺碳酸 聚乙二醇修饰 乙醇
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An efficient strategy for photocatalytic hydrogen peroxide production over oxygen-enriched graphitic carbon nitride with sodium phosphate 被引量:2
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作者 Yu Zhang Ling Zhang +4 位作者 Di Zeng Wenjing Wang Juxue Wang Weimin Wang Wenzhong Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第10期2690-2698,共9页
Photocatalytic hydrogen peroxide(H_(2)O_(2))production is a promising strategy to replace the traditional production processes;however,the inefficient H_(2)O_(2) productivity limits its application.In this study,oxyge... Photocatalytic hydrogen peroxide(H_(2)O_(2))production is a promising strategy to replace the traditional production processes;however,the inefficient H_(2)O_(2) productivity limits its application.In this study,oxygen-rich g-C_(3)N_(4) with abundant nitrogen vacancies(OCN)was synthesized for photocatalytic H_(2)O_(2) production.X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy indicated that oxygen-containing functional groups(–COOH and C–O–C)were obtained.Electron paramagnetic resonance confirmed the successful introduction of nitrogen vacancies.OCN exhibited efficient photocatalytic H_(2)O_(2) production performance of 1965μmol L^(−1) h^(−1) in air under visible-light irradiation.The high H_(2)O_(2) production was attributed to the enhanced adsorption of oxygen,enlarged specific surface area,and promoted carrier separation.An increased H_(2)O_(2) production rate(5781μmol L^(−1) h^(−1))was achieved in a Na_(3)PO_(4) solution.The improved performance was attributed to the changed reactive oxygen species.Specifically,the adsorbed PO_(4)^(3−) on the surface of the OCN promoted the transfer of holes to the catalyst surface.•O_(2)−obtained by O_(2) reduction reacted with adjacent holes to generate 1O_(2),which could efficiently generate H_(2)O_(2) with isopropanol.Additionally,PO_(4)^(3−),as a stabilizer,inhibited the decomposition of H_(2)O_(2). 展开更多
关键词 PHOTOCATALYSIS Hydrogen peroxide production Graphitic carbon nitride Singlet oxygen Sodium phosphate
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An investigation on dissolution kinetics of single sodium carbonate particle with image analysis method 被引量:1
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作者 Changdong Li Carlos Amador Yulong Ding 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第10期1487-1496,共10页
Dissolution kinetics of sodium carbonate is investigated with the image analysis method at the approach of single particle.The dissolution experiments are carried out in an aqueous solution under a series of controlle... Dissolution kinetics of sodium carbonate is investigated with the image analysis method at the approach of single particle.The dissolution experiments are carried out in an aqueous solution under a series of controlled temperature and p H.The selected sodium carbonate particles are all spherical with the same mass and diameter.The dissolution process is quantified with the measurement of particle diameter from dissolution images.The concentration of dissolved sodium carbonate in solvent is calculated with the measured diameter of particle.Both surface reaction model and mass transport model are implemented to determine the dissolution mechanism and quantify the dissolution rate constant at each experimental condition.According to the fitting results with both two models,it is clarified that the dissolution process at the increasing temperature is controlled by the mass transport of dissolved sodium carbonate travelling from particle surface into solvent.The dissolution process at the increasing pH is controlled by the chemical reaction on particle surface.Furthermore,the dissolution rate constant for each single spherical sodium carbonate particle is quantified and the results show that the dissolution rate constant of single spherical sodium carbonate increases significantly with the rising of temperature,but decreases with the increasing of pH conversely. 展开更多
关键词 Sodium carbonate Single particle Dissolution rate constant Image analysis
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Rock Cutting Analysis Employing Finite and Discrete Element Methods
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作者 Carla Massignani Carrapatoso Carlos Emmanuel Ribeiro Lautenschlager +1 位作者 Guilherme Lima Righetto Sergio Augusto Barreto da Fontoura and Nelson Inoue 《Journal of Mechanics Engineering and Automation》 2016年第2期100-108,共9页
The petroleum industry has shown great interest in the study of drilling optimization on pre-salt formations given the low rates of penetration observed so far. Rate of penetration is the key to economically drill the... The petroleum industry has shown great interest in the study of drilling optimization on pre-salt formations given the low rates of penetration observed so far. Rate of penetration is the key to economically drill the pre-salt carbonate rock. This work presents the results of numerical modeling through finite element method and discrete element method for single cutter drilling in carbonate samples. The work is relevant to understand the mechanics of drill bit-rock interaction while drilling deep wells and the results were validated with experimental data raised under simulated downhole conditions. The numerical models were carried out under different geometrical configurations, varying the cutter chamfer size and back-rake angles. The forces generated on the cutter are translated into mechanical specific energy as this parameter is often used to measure drilling efficiency. Results indicate that the chamfer size does not change significantly the mechanical specific energy values, characteristic. Results also show there is a significant increase although the cutter aggressiveness is influenced by this geometrical in drilling resistance for larger values of back-rake angle. 展开更多
关键词 Rock cutting discrete element method finite element method single cutter test.
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A simple method to model the reduced environment of lake bottom sapropel formation
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作者 Olga L.GASKOVA Vera D.STRAKHOVENKO +2 位作者 Nadezhda I.ERMOLAEVA Eugene Yu.ZARUBINA Ekaterina A.OVDINA 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第4期956-966,共11页
The Kambala and Barchin brackish lakes (Baraba steppe, southern West Siberia) contain an organic-rich sapropel layer that was formed in oxygen-depleted waters. We measured the bulk sediment elemental composition, th... The Kambala and Barchin brackish lakes (Baraba steppe, southern West Siberia) contain an organic-rich sapropel layer that was formed in oxygen-depleted waters. We measured the bulk sediment elemental composition, the water chemistry and determined the mineralogical composition and predominant biota species (Diatoms and Cyanobacteria in phytoplankton community respectively) in the lakes. The result indicates that the first lake has a siliceous type of sapropel and the second a carbonaceous one. A computer thermodynamic model was developed for chemical interaction in water-bottom sediment systems of the Kambala and Barchin Lakes. The surface sodium bicarbonate waters are supersaturated with respect to calcite, magnesite (or low Mg-calcite), quartz and chlorite with minor strontianite, apatite and goethite (pH 8.9-9.3, Eh 0.3 V). Nevertheless, it is shown that during sapropel deposition, deep silt waters should be anoxic (Eh〈0 V). The virtual component CH20 has been used to create an anoxic environment suitable for pyrite formation due to the biotic community impact and abiotic reduction. Thermodynamic calculation has shown that silt water is not necessarily euxinic (anoxic and sulfidic). Depending on Eh, sulfate sulfur can dominate in solution, causing the formation of gypsum together with pyrite. An attempt was made to find a reason for solution supersaturation with respect to Ca and Mg ions due to their complexation with humic acids. 展开更多
关键词 brackish lakes sapropel sediments mineral composition silica CALCITE thermodynamic calculations
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Effect of Dietary Lipid Levels on Fatty Acids Composition of Cultured Sparusaurata
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作者 Zayene Nesrine Gam Haouas Wafa +1 位作者 Guerbej Hamadi Achour Lotfi 《Journal of Life Sciences》 2016年第6期312-320,共9页
The aim of this study was to determine the progressive evolution of fish muscle fatty acids composition feeding by different lipid levels of farmed Mediterranean gilthead sea bream (Sparusaurata). During twenty one ... The aim of this study was to determine the progressive evolution of fish muscle fatty acids composition feeding by different lipid levels of farmed Mediterranean gilthead sea bream (Sparusaurata). During twenty one weeks, Sparusaurata were hand-feed two diets with protein and lipid ratios 47/20 (Diet A) and 45/22 (Diet B) respectively. At the end of the feeding period, lipid contents of muscle, as well as fatty acids profiles of different portions of the muscles were studied. Results indicated the effects of fatty acids profiles of diets throughout the liver and white muscle fillet (dorsal, middle and ventral). These were more noticeable when Sparusaurata was fed on the diet Athat decreased the content of monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) in all the muscles during the period of feeding while the saturated fatty acids (SFA) content tended to increase and it was lower than ones in the muscles of Sparusaurata fed on diet B. The highest amount of PUFA and docosahexaenoic acid, (22:6n-3 DHA) were found among the different portions of ventral muscles. In addition, the progressive evolution of different parts of muscle's fatty acid profiles showed significant differences in contents of SFA, PUFA and especially the n-3 PUFA. However, the content of MUFA seems to be alike in different muscles and tended to decrease in dorsal and ventral muscle from Do to Df and inversely when the fish were fed on diet A. 展开更多
关键词 Fatty acids LIVER Muscles cultured fish Sparusaurata.
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Grafting of Chitosan and Chitosantrimethoxylsilylpropyl Methacrylate on Single Walled Carbon Nanotubes-Synthesis and Characterization
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作者 Laura Carson Cordelia Kelly-Brown +6 位作者 Melisa Stewart Aderemi Oki Gloria Regisford Julia Stone Pasakorn Traisawatwong Clarissa Durand-Rougely Zhiping Luo 《Journal of Chemistry and Chemical Engineering》 2010年第9期6-13,共8页
Acid functionalized single walled carbon nanotubes (CNTs) were grafted to chitosan by first reacting the oxidized CNTs with thionyl chloride to form acyl-chlorinated CNTs. This product was subsequently dispersed in ... Acid functionalized single walled carbon nanotubes (CNTs) were grafted to chitosan by first reacting the oxidized CNTs with thionyl chloride to form acyl-chlorinated CNTs. This product was subsequently dispersed in chitosan and covalently grafted to form CNT-chitosan. CNT-chitosan was further grafted onto 3-trimethoxysilylpropyl methacrylate by free radical polymerization conditions, to yield CNT-g-chitosan-g-3-trimethoxysilylpropyl methacrylate (TMSPM), hereafter referred to as CNT-chitosan-3-TMSPM. These composites were characterized by Fourier Transform Infrared Resonance Spectroscopy (FTIR), carbon-13 nuclear magnetic resonance (13C NMR), Yhermogravimetric Analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite showed improved thermal stability and could be of great potential use in bone tissue engineering. 展开更多
关键词 CHITOSAN carbon nanotube NANOCOMPOSITES TEM.
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去神经对大鼠骨骼肌碳酸酐酶Ⅲ表达和磷酸酶活性的影响 被引量:1
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作者 黄河 任惠民 《中华神经科杂志》 CAS CSCD 北大核心 2011年第6期408-412,共5页
目的 观察去神经对骨骼肌碳酸酐酶Ⅲ(carbonic anhydrase Ⅲ,CAⅢ)表达及其磷酸酶(phosphatase)活性的影响,探讨神经冲动受阻是否为重症肌无力(myasthenia gravis,MG)骨骼肌CAⅢ减少的原因.方法 定向切断支配大鼠趾长伸肌(extens... 目的 观察去神经对骨骼肌碳酸酐酶Ⅲ(carbonic anhydrase Ⅲ,CAⅢ)表达及其磷酸酶(phosphatase)活性的影响,探讨神经冲动受阻是否为重症肌无力(myasthenia gravis,MG)骨骼肌CAⅢ减少的原因.方法 定向切断支配大鼠趾长伸肌(extensor digitorum longus,EDL)和比目鱼肌(soleus,Sol)的神经纤维,术后第7、14、28和56天用Western blot分析EDL和Sol的CAⅢ水平,用固相膜上原位酶活性染色方法评估CAⅢ的磷酸酶活性.结果 (1)正常侧(即去神经对侧)Sol的CAⅢ水平远高于EDL,并且两者都表现出随时间增加(动物年龄增长)而增加的趋势.去神经后,EDL的CAⅢ水平随时间的延长而逐渐增加;Sol的CAⅢ水平则以14 d为分界先增加后降低.(2)正常侧Sol的CAⅢ的磷酸酶活性[随时间增加(动物年龄增长)呈逐渐增加的趋势]均高于EDL(变化不明显).去神经后,Sol的CAⅢ磷酸酶活性(第14、28、56天分别为14.39±1.93、11.48±1.46、9.04±1.46)明显低于正常侧(22.75±1.80、25.26±3.15、25.82±2.97,t=0.002、0.005、0.002,均P<0.05),EDL的CAⅢ磷酸酶活性与正常侧相比亦是降低,但差异无统计学意义.(3)正常侧EDL和Sol的CAⅢ蛋白表达水平和CAⅢ的磷酸酶活性相一致;去神经后CAⅢ蛋白表达水平和CAⅢ的磷酸酶活性发生了背离,即CAⅢ蛋白表达水平增加,但其磷酸酶活性却降低.结论 去神经所致的神经冲动传递障碍与MG自身抗体所致的神经冲动传递障碍对骨骼肌CAⅢ表达水平的影响不同,MG骨骼肌CAⅢ表达水平减少并非是其自身抗体所致的神经冲动传递障碍造成. 展开更多
关键词 去神经支配 骨骼 碳酸酐酶Ⅲ 碳酸酯水解酶类 重症肌无力
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Hybrid copolymerization of cyclic and vinyl monomers 被引量:2
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作者 YANG HongJun XU Jinbao ZHANG GuangZhao 《Science China Chemistry》 SCIE EI CAS 2013年第8期1101-1104,共4页
In this work, we report the hybrid copolymerization of various cyclic monomers and vinyl monomers. Our studies demonstrate that 1-tert-butyl-4,4,4-tris-(dimethylamino)-2,2-bis[tris(dimethylamino) phophoranyliden-a... In this work, we report the hybrid copolymerization of various cyclic monomers and vinyl monomers. Our studies demonstrate that 1-tert-butyl-4,4,4-tris-(dimethylamino)-2,2-bis[tris(dimethylamino) phophoranyliden-amino]-2A5,A5-catenadi(phosphazene) (t-BuP4) can catalyze the hybrid copolymerization of caprolactone (CL), lactide (LA) or cyclic carbonate ester with acrylate or methyl acrylate. However, the polymerization of cyclosiloxane with vinyl monomers yields two corresponding homopolymers, and the polymerization of lactone with acrylonitrile (AN) produces only polyacrylonitrile. Clearly, the extent of matching of activity between a monomer and an active center determines whether or not there is hybrid copolymerization. 展开更多
关键词 hybrid copolymerization vinyl monomer cyclic monomer
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Sodium carbonate-assisted synthesis of hierarchically porous single-crystalline nanosized zeolites 被引量:1
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作者 Xiaoxia Zhou Yu Chen +3 位作者 Tongguang Ge Zile Hua Hangrong Chen Jianlin Shi 《Science Bulletin》 SCIE EI CAS CSCD 2017年第14期1018-1024,共7页
Hierarchically porous single-crystalline nanosized zeolites as heterogeneous catalysts show great poten- tial in fine chemistry because they offer more rich hierarchically porous channels for the mass transfer and mol... Hierarchically porous single-crystalline nanosized zeolites as heterogeneous catalysts show great poten- tial in fine chemistry because they offer more rich hierarchically porous channels for the mass transfer and molecular diffusion. However, the synthesis of hierarchically porous nanosized zeolites generally requires the assistance of templates acting as the mesoporogens, which limits its popularity. Herein, we report a one-pot and template-free synthesis of hierarchically porous single-crystalline nanosized zeolite beta only by introducing sodium carbonate in precursor solution. The resulted sample features the extraordinary properties, including the uniform nanocrystal (200-300 nm), high pore volume (0.65 cm3g 1) and the hierarchical pore-size distribution (e.g., 2-8 and 90-150 nm). After slicing pro- cessing, it is interestingly found that a large number of interconnected mesopores penetrate throughout whole material, which enables the hierarchically porous nanosized zeolite beta remarkably superior cat- alytic activity than the conventional zeolite beta in condensation of henzaldehyde with ethanol at room temperature. More importantly, this one-pot sodium carbonate-assisted synthetic strategy is highly ver- satile, which has also been successfully developed to synthesize hierarchically porous nanosized single- crystalline zeolites ZSM-5 and TS. 展开更多
关键词 Hierarchically porous Single-crystalline Beta/ZSM-5/TS Sodium carbonate Template-free Condensation of benzaldehyde
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Fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age 被引量:2
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作者 Hong-gang TANG Li-hong CHEN +1 位作者 Chao-geng XIAO Tian-xing WU 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2009年第2期154-158,共5页
We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysi... We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis. Moisture, protein, lipid and ash contents were determined by methods of Association of Analytical Chemist (AOAC) International. Fatty acid profile was deter- mined by gas chromatography. Crude protein, fat, moisture and ash contents showed no significant differences between the two age groups. The contents of total polyunsaturated fatty acids and docosahexaenoic acid (DHA) were significantly higher and eicosapentaenoic acid (EPA) content was significantly lower in the two-year-old large yellow croaker than in the one-year-old (/'〈0.05). No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty acids, or the ratio ofn-3/n-6 fatty acids among the large yellow croakers of the two age groups. We conclude that large yellow croakers are good food sources of EPA and DHA. 展开更多
关键词 Fatty acid Large yellow croaker Age
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Injection of stored nucleotides from single-walled carbon nanotubes
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作者 Zhen-hai LI Wei YANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2010年第10期709-713,共5页
We investigate the possibility of injection of a nucleotide via single-walled carbon nanotubes (SWNTs). The collapse process of an SWNT with a large radius may proceed like falling dominoes. The characteristics of a l... We investigate the possibility of injection of a nucleotide via single-walled carbon nanotubes (SWNTs). The collapse process of an SWNT with a large radius may proceed like falling dominoes. The characteristics of a large radius SWNT are utilized to drive the nucleotide movement in the SWNT, or even to inject the stored nucleotide out of the SWNT. In this process, the lateral section of the collapsed SWNT resembles a dumbbell. Occasionally, the nucleotide in the SWNT will be inbreathed into one of the two dumbbell ends, leading to interference with the injection process. To investigate the random nature of the injection process, a series of simulations on SWNT with different lengths were carried out. It was found that the injection probability was not influenced by the tube length. Freezing the nucleotide at the beginning, or modifying the SWNT at the outlet, may serve to facilitate the injection process, as indicated by the rise in the injection probability. 展开更多
关键词 Nano injection Single-walled carbon nanotube (SWNT) NUCLEOTIDE
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