2.5次微分极谱法测定药物中的叶酸

拟定了叶酸的2.5次微分示波极谱测定新方法.在HAc-NaAc (pH =5.6)缓冲溶液中,叶酸产生一灵敏的极谱还原波,峰电位Ep =-0.70 V (vs. SCE),其2.5次导数峰峰电流ep″与叶酸浓度在2.0×10-8～4.0×10-6 mol/L范围内呈线性关系(r=0.998 8, n=8),检出极限为4.0×10-9mol/L.13次平行测量4.0×10-7 mol/L叶酸的峰电流,所得RSD为1.2%.该方法已用于直接测定叶酸片中叶酸的含量.     

配位吸附波测定粮食中的痕量钼

在0.1 mol/L HAc-NaAc(pH=3.7)介质中,Mo(Ⅵ)-NCP配合物在2.5次微分极谱图上产生良好的吸附还原波。其峰电位为-0.54 V,峰电流与Mo(Ⅵ)浓度在8.0×10-8～6.0×10-6mol/L范围内呈良好的线性关系,检测限为5.0×10～8mol/L。应用该法测定了豆类样品中的微量钼,获得了满意的结果。研究了配合物的组成,极谱波的性质及其机理。     

单扫描示波极谱法测定酒石酸中的马来酸

建立了极谱测定酒石酸中马来酸含量的方法。在4.8×10-2mol/LH3PO4-KH2PO4(pH1.12)缓冲溶液中,马来酸极谱还原波的峰电位Ep为-0.77V(vs.SCE),其二阶导数峰峰电流i″p与马来酸浓度在3.0×10-7～4.0×10-4mol/L范围内呈线性关系(r=0.9974,n=8)。10次测量1.6×10-5mol/L马来酸还原波二阶导数峰峰电流,相对标准偏差RSD为2.1%。1000(w/w)倍酒石酸不干扰测定。通过对四种合成样品中马来酸的测定和回收率试验考察该方法,结果令人满意。     

环丙沙星的极谱测定及电化学行为研究

在0.03mol/LNH3-NH4Cl(pH=8.33)中,采用线性扫描极谱法测定环丙沙星,得到一良好的还原峰,峰电位Ep=-1.4V(vs.SCE) 峰电流ip与环丙沙星浓度在4.0×10-8～8.0×10-6mol/L范围内呈线性关系,相关系数r=0.9989,检测限为2.0×10-8mol/L 此法用于片剂的测定,方法简便,结果准确可靠 用线性扫描和循环伏安法研究了体系性质,结果表明,环丙沙星的电极过程为具有吸附性、动力性和不可逆性     

食品中痕量Cu(Ⅱ)、Pb(Ⅱ)的极谱测定

用单扫描极谱法研究了铜铁试剂(Cup)-六次甲基四胺(C6H12N4)-HAc体系的伏安行为,发现在pH为4.0~4.5,0.4 mol/L的六次甲基四胺中,铜(Ⅱ)、铅(Ⅱ)在铜铁试剂存在下,分别于-0.26 V(vs.SCE)-、0.58 V(vs.SCE)左右产生一尖锐、灵敏的二次导数极谱波.铜(Ⅱ)、铅(Ⅱ)的浓度分别在8.0×10-8~8.0×10-6mol/L、4.0×10-8~8.0×10-6mol/L的范围内与相应的峰电流成线性关系,检出限分别为1.0×10-8mol/L和6.0×10-9mol/L.该方法用于大米、大白菜中铜(Ⅱ)、铅(Ⅱ)浓度的测定,结果满意.     

尼可刹米的单扫描示波极谱研究

本文研究尼可刹米的单扫描示波极谱行为,在pH2.6的B.R.缓冲液中,于-1.28V(vs.CE)呈现一还原电流峰,与其含量有线性关系,线性范围是4.5×10~(-8)～4.0×10~(-8)mol/L,4.0×10~(-8)～8.0×10~(-8)mol/L。还用多种手段详细研究了极谱波的性质,确定其波是不可逆吸附还原波。     

碘酸钾存在下吡啶的极谱平行催化氢波研究

在0.10mol/L LiCl-8.0×10-4moL/L HCl-4.0×10-4mol/LKIO3支持电解中,吡啶产生一个新的极谱平行催化氢波,峰电位为-1600～-1700mV.该平行催化氢波二阶导数峰电流与吡啶的浓度在8.0×10-5～1.6×10-3mol/L范围呈线性关系,检测下限为2.5×10-5mol/L,可用于吡啶的分析研究.     

溴酸钾存在下苯丙氨酸的极谱催化波研究

在0.10mol/L LiCl-0.02mol/L HCl-8.0×10-3mol/L KBrO3支持电解质中,苯丙氨酸产生一个极谱催化波,峰电位为-1.65V(vs.SCE).该极谱催化波二阶导数峰电流与苯丙氨酸的浓度在2.0×10-5～2.5×10-3mol/L范围呈线性关系,其检测下限为6.5×10-6mol/L.本文建立了苯丙氨酸的分析测定方法,讨论了该极谱催化波的产生机理.     

氯霉素的单扫描示波极谱法测定

用单扫描示波极谱法研究氯霉素的电化学行为。在0.3mol/LKCl(pH=7.30)底液中,氯霉素在汞电极上有一线性扫描还原峰,其峰电位为Ep=-0.62V(vs.SCE)。峰电流与氯霉素浓度在1×10-7mol/L～9×10-6mol/L范围内呈现良好的线性关系(其线性相关系数r=0.9992),氯霉素的检出限可达5.0×10-8mol/L。该法用于模拟尿样的测定和氯霉素片剂含量的测定,结果令人满意。     

铁(Ⅲ)-钙镁试剂络合物吸附波的研究

在pH4.3的HAc-NaAc水溶液中,铁(Ⅲ)-钙镁试剂在滴汞电极上,于-0.56 V(vs.SCE)处有一良好的极谱波,其二阶导数峰电流与铁(Ⅲ)浓度在9.1×10-8~2.2×10-6mol/L(r=0.999,n=10)范围内有良好的线性关系,检测限为7.3×10-8mol/L.研究了络合物的组成和极谱波的性质.该方法已用于生物样品中铁的测定.     

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.     

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.     

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.     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-