甲氨蝶呤在Co/GC离子注入修饰超微电极上的电化学行为

甲氨蝶呤 (MTX)在 0 0 0 5mol·L-1 Tris 0 0 5mol·L-1 NaCl(pH7 12 )缓冲溶液中 ,用Co/GC离子注入修饰超微电极进行伏安测定 ,得到一良好的还原峰 ,峰电位Ep=- 0 978V(vs.SCE) .峰电流ip 与MTX的浓度在 8 0× 10 -8～ 9 6× 10 -6mol·L-1 范围内成线性关系 ,检出限为1 0× 10 -8mol·L-1 .基于此建立了测定MTX的新方法 .用于市售药片测定 ,回收率在 98 9%～10 6 2 %之间 .用线性扫描和循环伏安法研究了体系的电化学行为及电极反应机理 .实验表明 ,MTX的还原为不可逆吸附过程 ,并伴随 2个电子参与电极反应 .经扫速对催化效率的影响实验证明体系存在催化作用     

25,27-二羟基-26,28-二苯硫丙氧基-杯[4]芳烃-PVC修饰膜电极的伏安特性及其对金属离子的响应

制备了 2 5 ,2 7-二羟基 -2 6,2 8-二苯硫丙氧基 -杯 [4]芳烃 -PVC修饰膜电极。研究了该修饰电极在碱性、酸性介质中的伏安特性。实验表明 :修饰电极在 2mol·L- 1NaOH中的氧化还原过程为不可逆氧化过程 ,而乙醇的存在使碱性条件下的氧化过程受到抑制 ;在 1mol·L- 1HCl体系中 ,修饰电极具有良好的电化学活性 ,在 -1 .0V～ 0 .6V范围内有一对准可逆的氧化还原峰 ,并且在该条件下修饰电极对Zn2 + 、Pb2 + 、Cd2 + 、Hg2 + 、Ag+ 五种金属离子有良好的识别响应。     

洛美沙星的吸附伏安特性及其应用

在Britton Robinson(pH8 80 ) 0 0 2mol·L- 1KCl底液中 ,洛美沙星 (Lomefloxacin ,简称LMF)在汞电极上有一线性扫描还原峰 ,峰电位Ep=- 1 4 0V (vs.Ag/AgCl) ,该峰具有明显的吸附性 .吸附粒子为LMF中性分子 ,测得LMF在汞电极上的饱和吸附量Гs=4 2 7× 10 - 11mol·cm- 2 ,每个LMF分子所占电极面积为 3 89nm2 ,LMF在汞电极上的吸附符合Langmuir吸附等温式 .测得吸附系数 β =2 2 9× 10 6,2 5℃时的吸附自由能ΔG =- 36 2 9kJ·mol- 1,电极反应电子数n =2 ,不可逆体系动力学参数αnα=1 84 ,表面电极反应速率常数ks=0 2 9s- 1,扩散系数D =7 38×10 - 7cm2 ·s- 1.建立了吸附溶出伏安法测定LMF的最佳条件 ,检出限为 5 0× 10 - 8mol·L- 1.     

二甲基亚砜中Co2+、Ni2+和Fe2+的电化学行为

研究了二甲基亚砜中Co2+、Ni2+和Fe2+电化学行为. 在1.00×10-2 mol·L-1CoCl2-0.1 mol·L-1LiClO4-DMSO、1.00×10-2mol·L-1NiCl2-0.1 mol·L-1LiClO4-DMSO和1.00×10-2 mol·L-1FeCl2-0.1 mol·L-1LiClO4-DMSO体系中利用循环伏安法和计时电流法测定3种体系中Co2+、Ni2+和Fe2+的扩散系数DO. 结果在304 K时,循环伏安法测定3种体系中Co2+、Ni2+和Fe2+的扩散系数DO分别为1.31×10-5、1.27×10-5和1.59×10-5 cm2*s-1;在299 K时,计时电流法测定Co2+、Ni2+和Fe2+的扩散系数DO分别为1.01×10-5、1.43×10-5和1.39×10-5 cm2·s-1.     

金属杂多酸聚吡咯修饰电极的制备及应用

在圆盘电极上 ,用电化学方法将单缺位 Dawson型金属取代磷钨杂多酸盐 [α2 - K8P2 W17O61(Ni( ) OH2 )· 17H2 O,α2 - K8P2 W17O61(Co( ) OH2 )· 16 H2 O]的阴离子 (P2 W17)掺杂到聚吡咯 (PPy)薄膜中 ,制成 PPy/ P2 W17/ GC化学修饰电极 .研究电极对 NO-2 电还原过程的催化机理 .其还原电流 ipc值与 NO-2 浓度在 7.4 1× 10 -6～ 8.2 4× 10 -5mol· L-1和 1.74× 10 -4～ 1.2 1× 10 -2 mol· L-1范围内 ,呈良好的线性关系 .其中检测下限为 3.10× 10 -7mol· L-1,可用于酸雨中 NO-2 的测定     

丹皮酚的伏安行为及其应用

在 pH =7.8的NaOH KH2 PO4 底液中 ,用单扫示波极谱法可以得到一灵敏的丹皮酚导数还原峰 ,其峰电位Ep=- 1.6 5V(vs .SCE) .峰电流与丹皮酚的浓度在 4 .0× 10 - 7～ 1.0× 10 - 5mol·L- 1范围内呈线性关系 (r =0 .9998) ,检出限为 2 .0× 10 - 7mol·L- 1.该法用于牡丹皮中丹皮酚质量分数的测定 ,结果令人满意 .用线性扫描和循环伏安法研究体系的行为 ,结果表明 ,其电极过程为具有吸附性的不可逆过程     

壳聚糖包埋Ru(bpy)_3~(2+)/SiO_2复合膜电极电化学发光特性

制备了壳聚糖包埋Ru(bpy) 2 + 3 /SiO2 复合膜电极 .对其电化学发光特性的研究表明 :铂和玻碳复合膜电极循环伏安曲线的阳极峰分别在 115 0和 1370mV ,阴极峰分别在 10 5 0和12 6 0mV ;复合膜电极的荧光发射光谱位于 5 85nm ;电极的响应时间为 10s,对基质具有电位和 pH选择性 ;对 5 .5× 10 -4 1.0× 10 -2 mol·L-1的草酸和抗坏血酸分别有相关系数为 0 .995和0 .992的线性响应 ,S/N =3时的检测限分别为 5 .0× 10 -5和 6 .4× 10 -5mol·L-1,5次测量的相对标准偏差分别为 3.9%和 6 .8% ;铂和玻碳复合膜电极通常使用时间分别可达 30和 17d以上 .     

Eu(Ⅲ)-ARS络合物的极谱吸附波研究

研究了在 p H=9.6的氨 -氯化铵缓冲溶液中 ,Eu( )与茜素红 (ARS)络合物的极谱波 ,该极谱波峰电位在 -2 .2 5 V(sv. SCE) ,其峰电流与铕的浓度在 3 .0× 1 0 - 6 ～ 3 .0× 1 0 - 4 mol· L- 1 之间呈线性关系 ,最低检出限为 1 .0× 1 0 - 6 mol· L- 1 。利用该方法可测定稀土矿石中的中稀土元素铕     

甲氨蝶呤的电化学行为及应用的研究

在 0 .1mol·L- 1NH3 NH4 Cl (pH 9.8)缓冲溶液中 ,甲氨蝶呤在单扫示波极谱上有一灵敏的导数极谱峰 ,峰电位Ep=- 0 .83V(vs .SCE) .峰电流ip 与甲氨蝶呤的浓度在 5 .4× 10 - 8～ 6.5× 10 - 6 mol·L- 1范围内成线性关系 ,检出限为 4 .33× 10 - 8mol·L- 1.基于此建立了单扫示波极谱测定甲氨蝶呤的新方法 ,用于市售药片的测定 ,回收率在 92 .9%～ 10 6.8%之间 ,结果令人满意 .用线性扫描和循环伏安法研究了体系的电化学行为及电极反应机理 ,实验表明 ,甲氨蝶呤的还原属于具有吸附性的准可逆过程 ,并伴随 2个电子、2个氢离子参与电极反应 .     

Zn(Ⅱ)-Morin配位吸附波的研究及应用

以桑色素(Morin)为配位体,研究了Zn(Ⅱ)与其形成的配合物在汞电极上的极谱行为和极谱波的性质,确定了Zn(Ⅱ)-Morin配合物的组成.在pH=4.7的0.1 mol·L-1HAc-NaAc底液中,Zn(Ⅱ)-Morin配合物在2.0次微分极谱图上产生良好的吸附还原波.其峰电位为-1.14 V,峰电流与Zn2+在7.5×10-8～4.3×10-6 mol·L-1的浓度范围内呈线性关系,最低检出限为7.5×10-8 mol·L-1.用于实际样品测定,结果令人满意.     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Features of Women's language

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

A computer generator for randomly layered structures

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

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.