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1.
目的 建立蛇伤胶囊中5种蒽醌类成分含量测定分析方法,提升蛇伤胶囊质量标准。方法 采用Diamonsil C18色谱柱(250 mm×4.6 mm,5 μm),流动相为甲醇(A)-0.1%磷酸水溶液(B),梯度洗脱(0~7 min,75% A;7~30 min,75% A→90% A;30~40 min,90% A),流速为1.0 mL·min-1,检测波长为254 nm,进样量10 μL。结果 5个待测组的线性范围:4.04~40.40μg/mL(r=0.9994)、4.16~41.60μg/mL(r=0.9991)、4.14~41.40 μg/mL(r=0.9959)、4.10~41.00 μg/mL(r=0.9993)和2.16~21.60μg/mL(r=0.9997)。平均回收率(n=6)分别为100.02%、100.02%、100.03%、99.99%和100.06%,RSD分别为0.40%、0.15%、0.30%、0.11%和0.47%。结论 所建立的方法操作简便准确且具有良好的重复性,可用于测定蛇伤胶囊中芦荟大黄素、大黄素、大黄酸、大黄酚和大黄素甲醚的含量。  相似文献   

2.
碳捕获与封存技术(CCS)是针对能源危机的一种综合性解决方案,胺基溶液CO2吸收与解吸是其关键技术步骤。试验以胺基溶液乙醇胺(MEA)为主体吸收剂,分别选取N-甲基二乙醇胺(MDEA)和4-(二乙胺)-2-丁醇(DEAB)为添加剂,然后分别选取γ-Al2O3和沸石分子筛(HZSM-5)为催化剂,探究不同配比条件对MEA的CO2解吸性能的影响。试验结果表明,添加DEAB比添加MDEA所消耗的热负荷更少,最高可减少61.8%,最低可达0.15~0.20 MW·h·t-1 CO2。相对于γ-Al2O3,HZSM-5能更显著地提高反应速率,反应速率最高可达17.2×10-3 mol·L-1·h-1。5 M(mol/L)MEA/1.25 M DEAB+HZSM-5的组合效果最佳,是胺基溶液CO2解吸的优选方案。  相似文献   

3.
采用浸渍法制备了负载型钯催化剂(Pd/γ-Al2O3),并将制备的催化剂应用于对苯醌加氢制备对苯二酚反应. 考察了不同反应温度、压力、时间、催化剂用量等因素对Pd/γ-Al2O3催化剂性能的影响. 以甲醇(CH4O)作为溶剂,在反应温度为30 ℃、氢气(H2)压力为3.0 MPa、反应时间为2 h、对苯醌和甲醇的质量比m(对苯醌):m(甲醇)=3:47、催化剂质量分数仅为0.25%(以对苯醌质量计)的条件下,对苯醌转化率为100%,对苯二酚的选择性为96.9%,产率为96.9%.  相似文献   

4.
目的 基于广义相加模型定量分析某地级市大气污染物PM2.5与居民呼吸系统疾病及恶性肿瘤死亡风险的相关性。方法 收集2016~2018年该地级市逐日PM2.5浓度数据、气象数据、居民呼吸系统疾病及恶性肿瘤死亡数据,进行描述性统计分析;采用基于Quasi-Poisson回归的广义相加模型(GAM),分析PM2.5与该市居民呼吸系统疾病和恶性肿瘤死亡风险间的相关关系。结果 2016~2018年该地级市大气PM2.5日均值为49 μg/m3,共有631 d超出《环境空气质量标准》GB3095-2012污染物浓度一级限值标准,占三年总天数的57.6%;广义相加模型滞后效应(Lag0~Lag7)显示,PM2.5浓度升高10 μg/m3,呼吸系统疾病死亡率在滞后5 d的影响最大(ER=0.699%(95%CI:0.121%~1.277%)),恶性肿瘤死亡率在滞后3 d时的影响最大(ER=0.443%(95%CI:0.013%~0.873%));寒季(11月~4月)期间,PM2.5浓度升高10 μg/m3,呼吸系统疾病死亡率在滞后6 d的影响最大(ER=0.952%(95%CI:0.269%~1.635%)),恶性肿瘤死亡率在滞后1 d时的影响最大(ER=0.819%(95%CI:0.177%~1.461%))。结论 该地级市PM2.5浓度升高会引起呼吸系统疾病和恶性肿瘤死亡率增加,特别是在寒季,PM2.5暴露对呼吸系统疾病的负性效应更显著。  相似文献   

5.
为研究海洋来源真菌橘青霉(Penicillium citrinum)的次生代谢产物及其活性,采用凝胶柱层析、正相硅胶柱层析以及高效液相色谱等方法对菌株发酵液的乙酸乙酯提取物进行分离,通过LC-MS、NMR结构鉴定和文献数据对比等方法进行鉴定。结果表明,分离到的7个已知化合物经鉴定分别为3,3-二吲哚烷基-1,2-丙二醇(1)、robillafuran (2)、asperfuran A (3)、gamahorin (4)、7-羟基-5-甲氧基-4,6-二甲基-异苯并呋喃酮(5)、5-甲氧基-4,6-二甲基-7-氧-α-L-鼠李糖基-异苯并呋喃酮(6)、pestynol (7)。化合物1-7均为首次从青霉属真菌中分离得到,化合物1首次从真菌的次生代谢产物中发现。活性筛选结果表明,化合物7具有抗菌活性,化合物17对Marc-145细胞具有较强的细胞毒活性,半数致死浓度(Median Lethal Concentration,LC50)值分别为57.397 μg/mL和35.386 μg/mL;在LPS诱导的BV-2细胞模型中,化合物24在浓度为12 μg/mL时,BV-2细胞的存活率分别为76.77%和69.69%,具有潜在的抗神经炎症活性。  相似文献   

6.
以松木屑为模版,制备了La2O3-CexZr1-xO2复合氧化物,用于催化餐饮废弃油合成生物柴油的酯交换反应。采用BET比表面积分析仪、扫描电子显微镜(SEM)对La2O3-CexZr1-xO2进行表征。研究不同制备方法对催化剂活性的影响,分析不同的反应条件对酯交换反应产率的影响。结果表明:当反应条件为x=0.5,催化剂量为餐饮废油质量的5%,甲醇与餐饮废油物质的量的比为54:1时,在165℃下反应4.5 h左右,酯交换反应获得生物柴油的产率为91.1%。  相似文献   

7.
[目的]提高介孔TiO2材料的光催化活性。[方法]采用蒸发诱导自组装法(EISA),以四氯化钛和钛酸丁酯为钛源,嵌段共聚物P123(EO20PO70EO20)为模板剂,制备介孔TiO2。用光化学修饰法将CdS掺进介孔TiO2中,合成对可见光有较好响应的复合材料,并利用X射线衍射(XRD)、透射电镜(TEM)、原子吸收分光光度法(AAS)和光催化等手段对样品进行表征。[结果]XRD和TEM结果表明成功合成有序的六方介孔材料;AAS确定复合材料中Cd的含量为0.96mg/g;光催化于500 W氙灯下以2×10-5mol/L次甲基蓝(MB)为模型污染物,结果显示CdS/TiO2复合材料的可见光催化活性明显提高。[结论]光化学修饰法制备的介孔CdS/TiO2复合材料可增强其可见光催化活性。  相似文献   

8.
目的 为了探索小桐子综合开发利用的价值,对小桐子生物碱粗提物杀虫抑菌活性进行初步研究。方法 以攀西地区2种农业主要害虫(甘蓝蚜虫、菜青虫)和3种病原菌(石榴干腐病菌、苹果腐烂病菌和草莓灰霉病菌)为试验材料,采用点滴法和生长速率法对小桐子生物碱粗提物的杀虫抑菌活性进行了生物测定。结果 在杀虫活性方面,小桐子生物碱粗提物对同翅目甘蓝蚜虫和鳞翅目菜青虫均具有较高触杀活性,其LC50值范围为42.247 8~46.249 7 mg/L,LC90值范围为331.714 0~342.491 7 mg/L,总体上与2.5%溴氰菊酯EC的杀虫效果相当;在抑制病原真菌方面,小桐子生物碱粗提物对石榴干腐病菌、苹果腐烂病菌和草莓灰霉病菌的EC50分别为 70.635 5、52.400 6和133.412 2mg/L,其抑菌效果一定程度上优于对照药剂50%多菌灵WP。结论 小桐子提取物有较强的杀虫抑菌作用,在植物源农药的开发方面具有良好的应用前景。  相似文献   

9.
以邻苯二酚、对苯二酚和间苯二酚为木质素模化物进行居里点裂解实验,利用气相色谱仪和气相-质谱联用仪进行产物检测. 实验结果显示: 对苯二酚裂解首先形成1,4-苯醌,开环后主要生成CO(1.6%,质量分数,以下同)和C2烃(2.7%)、C4烃(2.8%);邻苯二酚在670℃可检测到苯乙烯,开环产物主要为C4烃(5.2%)和CO(3.1%);间苯二酚开环反应后,CO和CO2产量均较高,分别为2.2%和1.7%,且C1烃~C5烃无明显偏向(1.1%~2.2%),其开环反应涉及CO和CO2两条反应路径,裂解过程较为复杂. 基于3种苯二酚裂解产物的分布情况,分析木质素裂解过程中芳基的开环反应机理及羟基相对位置对芳基开环反应的影响.  相似文献   

10.
目的 评价I-gel喉罩下七氟烷吸入全麻在新生儿短小手术中的应用效果。方法 选择行短小手术的新生儿40例,随机均分为I-gel喉罩组(A组)和气管插管组(B组),每组20例。七氟烷吸入诱导完成后,A组患儿置入I-gel喉罩,B组患儿插入气管导管,成功后行控制呼吸,七氟烷维持麻醉。结果 两组患儿插管(或喉罩)的成功率无显著差异;但A组患儿喉罩置入所需时间显著短于B组患儿的插管所需时间(P<0.05)。T1时A组患儿MAP、HR较B组明显降低(P<0.05);T1~T3时,两组患儿气道峰压、气道密封压、SPO2、PETCO2均在正常范围内,且两组患儿SpO2、PETCO2差异无统计学意义。A组患儿拔除喉罩后哭声嘶哑、呛咳、有血性分泌物发生率明显小于B组(P<0.05),两组患儿均未发生反流误吸。结论 I-gel喉罩下七氟烷吸入全麻用于新生儿短小手术,方便快捷,通气效果好,置入成功率高,不良反应少。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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