高碘酸钾氧化甲基紫褪色反应测定食品中的钒

建立一种用分光光度法测定食品中钒(Ⅴ)的方法.在柠檬酸介质中,根据高碘酸钾氧化甲基紫褪色反应测定食品中的钒(Ⅴ).研究了反应介质、试剂用量、反应温度以及反应时间等因素的影响,同时测定表观活化能及表观速率常数,并绘制工作曲线,确定线性范围及检出限.采用湿法消化和微波消化分别处理红薯、黄瓜和雪莲果,利用分光光度法进行测定.实验结果表明,测定波长为583 nm,在柠檬酸介质中,钒对高碘酸钾氧化甲基紫具有强烈的催化作用.最佳实验条件:0.2 mol/L的柠檬酸3.0 mL,2×10~(-2)mol/L的高碘酸钾2.5 mL,1.0×10-4mol/L的甲基紫3.0 mL,反应温度为90℃,反应时间为10 min,方法的检出限为1.98×10~(-2)μg/mL,线性范围为0-1.0μg/(25 mL),催化反应的表观活化能为10.097 kJ/mol,表观速率常数为1.625×10-3s~(-1).利用微波消化法处理样品具有更高的精密度.实验测得的样品的含量均未超过120 mg/kg,样品中钒(Ⅴ)含量均合格.     

流动注射化学发光分析法测定邻苯三酚

在碱性介质中,铁氰化钾直接氧化邻苯三酚产生化学发光信号,结合流动注射技术建立了一种测定邻苯三酚的化学发光新方法.该方法的相对发光强度与邻苯三酚的浓度在1.0×10-4-9.0×10-3 mol／L范围内呈线性关系,检出限为7.52×10-5 mol／L,对浓度为1.0×10-3 mol／L的邻苯三酚平行测定11次,相对标准偏差为1.58%,应用于湖水中的邻苯三酚的测定,结果满意.     

鲁米诺—高碘酸钾化学发光法测定盐酸苯乙双胍

在碱性条件下盐酸苯乙双胍对鲁米诺—高碘酸钾化学发光体系有强烈的增敏作用,结合流动注射技术,建立了流动注射化学发光测定盐酸苯乙双胍的新方法.在优化的实验条件下,测定盐酸苯乙双胍的线性范围为4.0×10-9~2.0×10-5 mol/L,检出限为6×10-10 mol/L,对于浓度为4.0×10-8 mol/L的盐酸苯乙双胍连续测定11次,测定值的相对标准偏差为1.1%,以片剂为基体,用标准加入法检验方法的回收率,测得结果在99.6%~100.5%之间.该方法用于盐酸苯乙双胍片剂中盐酸苯乙双胍的定量分析,结果满意     

Ru(phen)32+-SO32+-Ce(Ⅳ)体系化学发光法测定葡萄酒中的亚硫酸盐总量

提出了Ru(phen)32+-SO32+-Ce(Ⅳ)体系化学发光法测定溶液中亚硫酸盐的方法.SO32-浓度与化学发光强度在1.0×10-7～1.0×10-4mol/L范围内成正比,检出限为1.97×10-7mol/L(S/N=3),1.0×10-4mol/LSO32溶液重复6次测定结果的相对标准偏差为4.9%.该方法用于测定白葡萄酒中亚硫酸盐总含量为4.006×10-5mol/L,加标回收结果令人满意.     

流动注射-Luminol/Tween 20化学发光体系测定邻苯二酚

基于邻苯二酚对luminol-Tween 20化学发光体系的强烈的抑制作用,建立了一种简单、灵敏的luminol-Tween 20化学发光体系测定邻苯二酚的新方法。在最佳实验条件下,方法的检出限为5.0×10-10mol/L,线性范围为1.0×10-9mol/L～1.0×10-7mol/L,对5.0×10-8mol/L邻苯二酚进行平行测定11次,其RSD为4.1%。该方法可应用于自来水样中邻苯二酚的测定。     

铁氰化钾化学发光体系测定吲哚-3-乙酸

在碱性介质中,铁氰化钾可以直接氧化吲哚-3-乙酸（IAA）产生化学发光.基于此,结合流动注射分析技术,建立了一种化学发光测定IAA的新方法.该方法的线性范围为2.0×10^-7mol/L-1.0×10^-5mol/L,检出限为3.0×10^-8mol/L.对5.0×10^-7mol/L,1.0×10^-6mol/L,1.0×10^-5mol/L的IAA连续平行测定11次,测定的相对标准偏差分别为2.4%,2.5%和1.2%.将该法直接应用于土壤和池塘水中的IAA的测定,回收率在95.0%-104.8%之间.     

鲁米诺-铁氰化钾化学发光体系测定孔雀石绿

基于鲁米诺在碱性条件下可以被铁氰化钾催化氧化产生化学发光,孔雀石绿对此化学发光具有增敏作用这一现象,结合流动注射技术建立了一种直接测定孔雀石绿的流动注射化学发光新方法.结果表明,该方法的线性范围为1.0×10-6-9.0×10-5mol/L,检出限为4×10-7mol/L.对1.0×10-5mol/L的孔雀石绿连续进行七次平行测定,其相对标准偏差为2.3%.     

流动注射-鲁米诺-铁氰化钾化学发光体系测定环境水体中痕量2,4-二氯苯酚

基于中性介质中,2,4-二氯苯酚对鲁米诺-铁氰化钾化学发光体系有明显的增敏作用,提出了流动注射化学发光法测定痕量2,4-二氯苯酚的方法.在优化的试验条件下,2,4-二氯苯酚的化学发光强度与其浓度在1.0×10-7~1.0×10-5 mol/L范围内呈线性关系,方法的检出限(3S/N)为1.060×10-8 mol/L.对浓度为1.0×10-5mol/L2,4-二氯苯酚溶液连续测定11次,测定值的相对标准偏差为2.1%.取工业废水水样,经固相萃取后用该法测定其中痕量2,4-二氯苯酚含量,同行业推荐标准方法对比,结果相近.     

反相流动注射化学发光法测定姜黄素的研究

姜黄素对鲁米诺 过氧化氢 铬(Ⅲ)体系化学发光具有强烈的抑制作用,基于此首次建立了测定姜黄素的流动注射化学发光分析新方法.实验结果表明,在优化的实验条件下,化学发光信号强度ΔI与姜黄素的浓度在1.0×10-10～1.0×10-8mol/L范围内分段成良好的线性关系,方法检出限为5.0×10-11mol/L,相对标准偏差为2.8%(c=2.0×10-9mol/L,n=11).该法已应用于中药姜黄中姜黄素总量的测定.     

化学发光法测定水产品中链霉素残留

建立了水产品中链霉素残留的化学发光检测方法,最佳条件为:样品用100 g/L三氯乙酸提取后,经C18固相萃取柱净化,以0.1 mol/L NaOH调pH,5×10-4mol/L鲁米诺,5×10-4mol/L高碘酸钾,1×10-9mol/L锰离子为发光体系进行测定,在0.1~5 mg/L范围内,链霉素浓度与发光强度呈现良好的线性关系(r2=0.998 3),以三倍信噪比计算,检出限为0.05μg/g。该方法适用于测定经过前处理的水产样品(虾、鲫鱼和牙鲆)中链霉素的残留,准确度及精密度符合检测要求。     

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-