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 111 毫秒
1.
用Ag_2S和CuS以8∶1(或14∶3)的比混合物做为活性物质,用邻苯二甲酸二辛酯(DOP)为增塑剂。首次研制了非均相PVC膜铜离子选择性电极,电极的能斯特响应范围为5.0×10 ̄(-6)~1.0×10 ̄(-2)mol·L ̄(-1),平均斜率为30mV/PCU(25℃),电极的重现性和稳定性都比较好,电极的寿命可达三个月。用试制的PVC膜铜离子选择性电极测定了铜合金中铜的含量与经典法碘量法所得结果相吻合,还用试制的电极测定了标准精镁试样中微量铜的含量与标准值一致。  相似文献   

2.
用电化学法在玻碳基体上制备出性能稳定的铁氰酸钴膜修饰微电极(CHCF/GC),该电极可在-1.0V-1.0V(vsSCE)之间进行连续多次的电位扫描。表征了该电极的电化学多种行为,研究了影响CHCF膜电极性能的多种因素和该电极对抗坏血酸(AA)测定的催化作用。  相似文献   

3.
通过加入各种增容剂(Compatibilizer)和采用粉末丁苯橡胶(PSBR)及经接枝、交联改性的粉末丁苯橡胶(PMSBR),研究了提高聚氯乙烯/丁苯橡胶(PVC/SBR)共混相容性的途径。物理机械性能测试结果表明:五种增容剂对软质PVC/SBR共混物的改性效果以粉末丁腈P83和丁腈-26(NBR-26)最佳;粉末橡胶对PVC的改性效果优于块状橡胶,PMSBR对软质PVC的改性效果优于以NBR-26作增容剂的块状SBR和PSBR;用不同改性方法制得的四种PMSBR中,以多层乳液接枝改性的PMSBR-4对PVC的改性效果最佳,用它改性硬质PVC的缺口抗冲击强度和软质PVC的耐寒性,效果皆超过粉末丁腈P83。扫描电镜、透射电镜和动态力学谱分析表明:PVC/PMSBR-4共混材料呈良好的韧性断裂,橡胶粒子分散较均匀,相界面模糊,低温Tg升高,说明PVC/SBR的相容性获得显著提高  相似文献   

4.
一种建立生物指数的新方法   总被引:2,自引:0,他引:2  
依据水质化学参数和原生动物群落参数建立了一种新的生物指数:种类污染值(SPV)和群落污染值(CPV)。文中列出了438种原生动物的SPV,并提出了以CPV划分水质的范畴。经过证明,CPV可作为一种淡水水质评价的新方法。  相似文献   

5.
阐明了用零长毛细管流变仪和差示扫描量热计(DSC)测定PVC熔体凝胶度的原理。并采用这两种方法具体测定了PVC/CPE/PS体系的凝胶度。讨论了凝胶度与加工温度及力学性能的关系,对此两种方法的测试结果进行了比较。  相似文献   

6.
本文用铅笔芯制成的电极(PCE),与玻碳电极(GCE)比较,研究了Zn(Ⅱ)的阶梯循环伏安法(CSV)、阶梯阳极溶出伏安法(ASSV)和差分脉冲阳极溶出法(ASDPV)等的伏安特性。实验指出,PCE与GCE有相似的伏安特性曲线,且具有较好的重视性和选择性。由于PCE较GCE的结构疏松,电极表面积较大,故PCE的灵敏度RGCE高。其阳极溶出法的最低检出限可达到5×10-6mol·L-1的Zn(Ⅱ),Zn(Ⅱ)的浓度在3.6×10-4~8×10-6mol·L-1范围内与峰电流呈良好的线性关系。  相似文献   

7.
通过对PVC/PBA(聚氯乙烯/聚丙烯酸丁酯)和PS/PBA(聚苯乙烯/聚丙烯酸丁酯)两种LIPN的玻璃化转变温度Tg和动态力学等性能的测定,比较了它们的相容性和阻尼性能。实验结果表明PVC/PBALIPN的相容性和阻尼性能较PS/PBALIPN更好  相似文献   

8.
曲马多PVC膜选择性电极的研制   总被引:1,自引:0,他引:1  
周玲妹  徐献军 《河南科学》1994,12(2):119-122
介绍了一种曲马多PVC膜电极。该电极以曲马多——四苯硼缔合物为电活性物质,线性范围为4.0*10 ̄(-5)—4.0*10 ̄(-2)mol/L,检测下限为1.4*10 ̄(-5)mol/L,斜率为59.8mV/pc。电极在pH=3.0-7.0之间对曲马多的回收率为96.7%,电极被用于曲马多片剂和针剂中曲马多的含量测定,取得了较为满意的结果。  相似文献   

9.
采用直流气体放电活化反应蒸发沉积法,制备SnO2超微粒薄膜(UPF)作光电极。SEM分析结果表明,平均粒径为60nm。采用叶绿素铜钠盐作光敏剂、SnO2UPF作光电极、I/I3氧化还原作电解液,导电玻璃或镀有金属铝膜的载玻片作集电极,我电化学基片。研究I/I3电解液,染料、两极距离及不同集电极对光电性能的影响,获得单位面积的开路电压(VOC)为268mV,短路电流(ISC)为20μA。  相似文献   

10.
以三辛基十二烷基碘化铵(DTOA—I)为电活性物,邻苯二甲酸二丁酯(DBP)为增塑剂,制成聚氯乙烯(PVC)膜碘离子选择电极。电极对I-浓度在8.0×10-6~1.0×100mol·L-1范围内符合能斯特响应,其斜率为57.0mV/pI-(16℃)。用该电极测定了海盐中微量碘,回收率在93.22%~105.3%之间。  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 Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  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