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INTRODUCTION Shengmaiyin or Shengmaisan, one of the famous herbal recipes in traditional Chinese medicine, is made from Radix ginseng, Ophiopogon and Schi- sandra. It is used to treat hypotension (Chen et al., 2000; Gui, 2001), cardiovascular system diseases (Qian et al., 2004; Zeng and Zeng, 2004), to increase immunity (Wu et al., 1997; Guo et al., 2004) and cure other diseases (Li et al., 1996; Liu et al., 1998; Fang et al., 2000; Yi et al., 2003; Xu et al., 2003; Wang et al., 200… 相似文献
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Investigation on influencing factors of 5-HMF content in <Emphasis Type="Italic">Schisandra</Emphasis> 总被引：4，自引：0，他引：4
In order to investigate the influencing factors of 5-hydroxymethyl-2-furaldehyde （5-HMF） content in Schisandra, confirm the theory of 5-HMF deriving mainly from Schisandra processing course, and give some suggestions about the Schisandra processing method, the 5-HMF contents in decoctions of Schisandra under different heating temperature, decocting time, soaking time, processing methods and treatment with different solvents before decocting the Schisandra were measured by RP-HPLC method. The results showed that there is great difference of 5-HMF level in decoctions from differently processed Schisandra and unprocessed Schisandra; decocting time of 60 rain has some effects on 5-HMF level in decoctions and there is certain quantity 5-HMF in processed Schisandra itself and very little 5-HMF in unprocessed Schisandra. Heating time, heating temperature and treating solvents all have effect on 5-HMF level in decoction of Schisandra. 5-HMF in Schisandra was mainly from processing course. Both long heating time and high heating temperature can increase 5-HMF level in Schisandra. The production of 5-HMF in Schisandra may have some relationships with some polar components, which can dissolve in water, ethanol and acetone, especially in ethanol. To control processing temperature, processing time and treatment with some solvent is very important for controlling 5-HMF level in Schisandra. 相似文献
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谢存花 《南宁职业技术学院学报》2014,(3):75-78
利用IPCC提出的碳排放折算系数测算广西能源消费CO2排放,运用卡亚公式和完全分解模型分析人口规模、人均GDP、能源强度和CO2密度对广西能源消费CO2排放量变化的影响,结果发现:在19952011年,对广西能源消费CO2排放量增大起正作用的依次是人均GDP和人口规模,起负作用的依次是能源强度和CO2密度。因此减小广西能源消费CO2排放量,要控制人口规模、改善产业结构、能源结构和推动节能减排技术发展。 相似文献
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过渡金属配合物能催化、活化二氧化碳,使其与亲核试剂进一步发生反应生成羧酸。该文阐述了过渡金属配合物催化下二氧化碳羧基化反应的基本原理及方法,综述了近几年在这一领域的研究成果,并指出了该反应的研究意义。 相似文献
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通过银镜试验、甲酸银的形成与分解试验、高碘酸试验以及氢氧化钙试验对实验教学中5％的中性高锰酸钾溶液氧化乙烯的反应产物进行了详细研究,结合试验现象及相关理论得出乙烯被氧化得到的是乙二醇与甲酸钾的混合物,而无二氧化碳生成, 相似文献
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Ming-jiang Ni Xu Shen Xiang Gao Zu-liang Wu Hao Lu Zhong-shan Li Zhong-yang Luo Ke-fa Cen 《浙江大学学报(A卷英文版)》2011,12(1):71-77
The naphthalene decomposition in a corona radical shower discharge (CRS) was investigated, with attention paid to the influences of voltage and initial naphthalene density. The OH emission spectra were investigated so as to know the naphthalene decomposing process. The by-products were analyzed and a decomposing theory in discharge was proposed. The results showed that higher voltage and relative humidity were effective on decomposition. The initial concentration affected the decomposing efficiency of naphthalene. When the initial naphthalene density was 17 mg/m3, the decomposition rate was found to be 70% under 14 kV. The main by-products were carbon dioxide and water. However, a small amount of carbonic oxide, 1,2-ethanediol and acetaldehyde were found due to the incomplete oxidization. 相似文献
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徐辉艳 《陕西教育学院学报》2013,(2):55-59
为探讨温度和时间对红枣汁化学成分变化的影响,本试验将红枣汁在50-100℃温度下连续进行12小时处理,每隔2小时测定红枣汁中的5-HMF、总糖、氨基酸态氮、总酚、和Vc指标的变化。结果表明:随着加热温度的升高,时间的延长,红枣汁中的5-HMF含量逐渐增加,总糖、氨基酸态氮、总酚和Vc含量逐渐减少。 相似文献
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目的：研究纤维素分解菌的分离及产酶条件优化.方法：以含菌秸秆、腐木叶和玉米地土壤为原料,经富集、初筛培养后,根据水解圈直径/培养天数进行纤维素分解菌的复筛培养,测定CMC酶活和FPA滤纸酶活,并进行了产酶条件的单因素优化实验.结果：采集的样品中共分离到4个菌株,均为细菌,其中H-3的羧甲基纤维素（CMC）酶活和滤纸（FPA）酶活最高,分别是0.5401U.m l-1、0.2923U.m l-1.结论：H-3菌分解纤维素的能力最强,最佳产酶条件为温度30℃,pH4.5.不含尿素,葡萄糖和纤维素含量为0.4%和0.6%. 相似文献
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Decomposition of dimethyl sulfide （DMS） in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge （DBD） reactor at room temperature and atmospheric pressure. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network （BPFN） was adopted in our experiments. The maximum power output of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV, respectively. The important parameters affecting odor decomposition, including peak voltage, pulse frequency, gas flow rate, initial concentration, and humidity, which influenced the removal efficiency, were investigated. The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832 mg/m3 and a gas flow rate of 1000 ml/min. Humidity boosts the removal efficiency and improves the energy yield （EY） greatly. The EY of 832 mg/m3 DMS was 2.87 mg/kJ when the relative humidity was above 30%. In the case of DMS removal, the ozone and nitrogen oxides were observed in the exhaust gas. The carbon and sulfur elements of DMS were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, sulfur was discovered in the reactor. According to the results, the optimization design for the reactor and the matching of high pulse voltage source can be reckoned. 相似文献
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大气甲烷源和汇的研究 总被引：2，自引：0，他引：2
张秀君 《沈阳教育学院学报》2004,6(1):132-134
甲烷是重要的温室气体之一，其单分子增温潜势约是CO2的62倍，目前大气CH4的浓度约为1．7ppm。甲烷的主要自然源包括反刍动物和一些昆虫的肠发酵及淹水土壤的有机物的厌氧分解。人类源包括煤燃烧、天然气泄漏、热带植物燃烧及垃圾填埋场．包括垃圾填埋场在内，土壤的CH4排放量约占全球CH4产生量的45％。 相似文献
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制备了不同晶型的二氧化锰,并研究了不同晶型的二氧化锰对催化过氧化氢分解反应速率的影响.结果表明,β-MnO2(K2CO3)的催化活性最好.温度和用量对β-MnO2(K2CO3)催化分解过氧化氢反应有着明显的影响,随着温度和用量的增加,过氧化氢催化分解的反应速率也不断增加.催化剂的重复使用效果并不理想. 相似文献
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10种金属氧化物对氯酸钾热分解制氧催化效果的研究 总被引：1，自引：0，他引：1
加热KClO3分解制氧常使用MnO2作催化剂。实验发现：CaO，A12O3，CuO，FeO3，TiO2，Nd2O3，PdO2，V2O5，Cr2O39种金属氧化物及无机盐MnSO4，FeCl2，FeCl3，CoCl2，ZnCl2等亦有较好的催化效果，在试剂用量、产氧量、反应速度和控制副反应等方面具有明显的优点。 相似文献
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硫脲基咪唑啉缓蚀剂合成与研究 总被引：2，自引：0，他引：2
采用酸、胺比为1∶1.25，用反应15%-20%摩尔数的二甲苯为携水剂，在逐步升温的条件下，合成咪唑啉中间体，使其与二硫化碳反应，合成了硫脲基咪唑啉。然后对其作红外谱图，并通过动电位扫描极化曲线法初步探讨了它的缓蚀性能。实验结果表明：该实验产率比较高，而硫脲基咪唑啉对二氧化碳饱和的酸性环境中碳钢的腐蚀具有较好的缓蚀性能。 相似文献
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Dr Kam-Wah Lucille Lee 《Research in Science Education》1999,29(3):401-415
A growing area of interest in chemical education has been the research associated with conceptual understanding at the particulate level. This study investigated the views of 10 university chemistry lecturers, 85 pre-service chemistry teachers and 23 Secondary 3 (equivalent to Year 9) chemistry students about the particulate level of a chemical reaction, namely the heating of copper (II) carbonate. Four characteristic views were identified on the basis of their diagrammatic representations of particles. These were: (a) formation of intermediates; (b) formation of free particles (e. g., atoms or ions); (c) combination of a and b: formation of free particles (e. g., atoms or ions) first, and then intermediates; (d) no mechanism. Both the majority of the lecturers and the pre-service teachers held an identical view about the reaction mechanism, namely that the decomposition of copper (II) carbonate goes through a transition stage by forming intermediates. In contrast, even though the students were familiar with this reaction, about half of them naïvely believed that copper (II) carbonate broke up on heating and the particles recombined directly to form copper (II) oxide and carbon dioxide, the two observed products. About one-third of the students had neither any notion of how the atoms in the copper (II) carbonate lattice interacted and were rearranged in the reaction nor any concept of bond-breaking and reformation in a chemical reaction. 相似文献
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以脱脂棉为原料,用氢氧化钠、尿素、硫脲体系作为溶剂,对纤维素进行溶解,然后加入水合肼,对纤维素羟基进行破坏,使纤维素降解．主要通过研究水合肼用量、反应温度、反应时间对纤维素溶解体系粘度的影响,从而判断水合肼对纤维素溶解稳定性的影响．当棉花质量：水合肼体积=10：7、反应温度15℃、反应时间2h时,△η最大,对纤维素溶解体系稳定性破坏最大． 相似文献
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研究采用机械力化学辅助作用下制备高吸附性能木质活性炭,探讨了研磨时间、浸渍比（磷酸与绝干杉木屑的质量之比,下同）、磷酸浓度对所制备活性炭的碘吸附值和亚甲基蓝吸附值的影响;同时,采用比表面积及孔隙分析仪和傅立叶红外光谱仪（FT-IR）对活性炭的表面官能团、比表面积、孔容及孔径分布等进行了表征.分析显示：经过机械力化学辅助作用处理后,机械力化学激活作用有利于木屑与磷酸之间发生更多的化学反应,同时促进更多纤维素发生热解;此外,机械力化学辅助作用可能降低了纤维素热解过程中聚合及芳构化阶段的温度;通过N2吸附等温线分析表明机械力化学法所制备活性炭具有丰富的微孔结构. 相似文献
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吴永军 《荆门职业技术学院学报》2011,(5):5-9,17
通过对溶液还原糖浓度以及粘度的测定研究了纤维素酶对壳聚糖的降解作用,探讨了酶解过程中温度、pH值以及反应时间对纤维素酶降解壳聚糖的影响,对降解前后壳聚糖的结构进行了表征并对其水溶性进行了测试。结果表明：纤维素酶降解壳聚糖的最佳pH值为4.5,温度为50℃。随着反应时间的延长,壳聚糖溶液的黏度逐渐降低;随着壳聚糖分子量的降低,水溶性增强,其化学结构没有改变。 相似文献
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