首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 265 毫秒
1.
 建立了测定丁公藤中东莨菪内酯含量的高效毛细管电泳-电导法,乙酸-乙酸铵(乙酸铵浓度为20 mmol/L)为电泳介质,在20 kV高压,pH 3.5条件下柱端电导检测了丁公藤中东莨菪内酯含量。文章着重探讨了缓冲溶液种类、浓度、酸碱度及其操作电压,进样时间,有机添加剂等条件对检测的影响。方法的线性范围为:5.0~200.0 mg/L,相关系数r= 0.999 8,检出限为1.0 mg/L。结果表明该法简便、快速、准确,回收率较高,适用于丁公藤中东莨菪内酯含量的测定。  相似文献   

2.
为了了解海南南渡江的无机物和有机磷农药指标情况,对南渡江18个站点水样中氯化物、硝酸盐、硫酸盐、有机磷农药进行检测.试验结果显示流水坡和南渡江大桥两处水样的氯化物含量超过国家标准,分别为9564.810 mg/L和462.56 mg/L,鹿寨处水样的氯化物浓度最高为35.00 mg/L,西江处水样的氯化物浓度最低为17.44 mg/L.南渡江水样的硝酸盐含量均符合国家标准,永发处水样硝酸盐的浓度最高,为5.2 mg/L;福才处水样硝酸盐的浓度最低,为0.1 mg/L.仅有流水坡处水样的硫酸盐含量超过国家标准,为494.50 mg/L,南渡江大桥处水样的硫酸盐含量最高,为110.50 mg/L;那大处水样的硫酸盐含量最低,为0.19 mg/L.流水坡和南渡江大桥处于近海口,硫酸盐和氯化物超标主要原因是海水入侵导致.南渡江水域没有检测出有机磷农药.整体来看,南渡江流域氯化物、硝酸盐、硫酸盐和有机磷农药含量符合地表水环境质量标准.  相似文献   

3.
紫外分光光度法测定水样中五氯酚   总被引:6,自引:0,他引:6  
采用紫外分光光度法, 在波长320 nm处测定碱性条件下水样中五氯酚的含量, 其线性回归方程为Y=0.0052X+0.0002, 相关系数r=0.999 9,线性范围是1.88~187.73 μmol/L, 检出限为0.27 μmol/L, 相对标准偏差均小于5%(n=6), 加标回收率为100.70%~103.75%.  相似文献   

4.
用线性扫描极谱法和循环伏安法研究秋水仙碱在0.2mol/L NH3-NH4Cl缓冲溶液(pH9.63)中的电化学行为,秋水仙碱于-1.304V(vs.SCE)处产生一灵敏的吸附波,在秋水仙碱浓度为0.05~10.0mg/L范围内,其一次微分线性扫描峰电流与秋水仙碱浓度呈良好的线性关系,线性回归方程为Ip=0.00310+0.29373C,相关系数r=0.99287(n=10),检出限为0.03mg/L。对5.0mg/L秋水仙碱溶液进行6次平行试验,RSD为2.10%,回收率在98.00%~102.10%之间。方法可用于片剂中秋水仙碱含量的测定。  相似文献   

5.
目的 测定无限极口服液中微量元素Mn的含量.方法 光源用锰空心阴极灯,波长为279.5 nm,灯电流为3.0 mA,狭缝1.2 nm,空气流量5.0 L/min,乙炔流量1.0 L/min.结果 Mn在0.5~2.5 mg/L质量浓度范围内线性关系良好(r=0.999 5),平均加样回收率为99.00%(RSD=2.25%,n=5).结论 该方法简便、快速、准确、灵敏度高、精密度好.  相似文献   

6.
目的 测定无限极儿童口服液中微量元素Zn的含量.方法 光源用锌空心阴极灯,波长为213.8 nm,灯电流为2.5 mA,狭缝1.2 m,空气流量5.0 L/min,乙炔流量1.0 L/min.结果 Zn在1~7 mg/L质量浓度范围内线性关系良好(r=0.999 6),平均加样回收率为99.45%(RSD=2.16%,n=5).结论 该方法简便、快速、准确、灵敏度高、精密度好.  相似文献   

7.
用Agilent SB C18(150 mm×4.6 mm, 5.0 μm)色谱柱, 在优化流动相最佳体积比和流速的条件下, 用超声萃取 高效液相色谱法测定不同类型土壤中硝化抑制剂——2-氯-6-(三氯甲基)吡啶(nitrapyrin, CP)的质量浓度. 结果表明: 土壤样品经3次乙醇溶剂超声萃取后, 通过有机滤膜净化, 以V(乙腈)∶V(水)=4为流动相, 在0.8 mL/min流速下10 min[KG*8]内完成色谱柱(Agilent SB C18)的分离, 提取效果较好; 在0~75 mg/L内, CP的质量浓度与峰面积呈显著的线性关系(R2=0.999 8, p<0.01); 空白土壤中CP的检出限为042 mg/L; 不同质量浓度和剂型的CP溶液在草甸黑土、 黑钙土和风沙土中添加24 h后的回收率为82.44%~91.66%, 标准偏差为1.34~5.04, 变异系数为0.02~0.06.  相似文献   

8.
利用辣椒花药诱导单倍体研究表明:NTH,MS培养基均能诱导产生愈伤组织和胚状体,但NTH培养基比MS培养基培养效果好,以NTH+6-BA 0.2mg/L+NAA 0.5mg/L+KT 1.2mg/L+AgNO3 5.0 mg/L为愈伤组织和胚状体诱导的适宜培养基。通过花药培养获得的辣椒植株中,具有丰富的倍性变异,经染色体计数鉴定,单倍体( n=12 )约14%,二倍体(2n=24 )约46%,四倍体(4n=48 ) 约4%,各种混倍体约36%.  相似文献   

9.
流动注射电化学发光分析法测定土霉素   总被引:1,自引:0,他引:1  
基于土霉素在铂电极上增强三联吡啶合钌[Ru(bpy)3^2+]的电化学发光信号,并结合流动注射分析技术,建立了1种测定土霉素的电化学发光分析新方法.在含有5.0&#215;10^-5mol/L Ru(bpy)3^2+的pH=8.0磷酸盐缓冲溶液中,采用1.15 V的应用电位和2.0 mL/min的流速,测定土霉素的检出限为1.30 mg/L(S/N=3),线性范围为2.50-25.0 mg/L,相对标准偏差小于1.50%(n=9),加标回收率为97.4%-104%.该法简单、快速、灵敏,现已成功地用于药物制剂中土霉素含量的测定.  相似文献   

10.
离子色谱在水质分析中的应用   总被引:2,自引:0,他引:2  
曹建明 《山西科技》2005,(3):117-118
文章采用离子色谱法, Shim - PackICAl 阴离子柱,以2. 5mmol/L 邻苯二甲酸 2 4mmol/L三(羟甲基)氨基甲烷为流动相,同时测定饮用水中氯化物、硝酸盐氮和硫酸盐的含量。该法回收率为99%~102%,相对标准偏差均<3%,最低检测限分别为0 010mg/L、0 005mg/L、0.020mg/L。实验证明该方法快速、简便、准确、灵敏度高。  相似文献   

11.
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   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
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   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号