顶空气相色谱法测定水中丙烯腈、苯乙烯

应用顶空气相色谱法测定水中微量丙烯腈、苯乙烯，样品在顶空并中90℃温度中气液平衡20min后．吸取顶空气体1mL进行色谱测定，丙烯腈、苯乙烯最低检出浓度分别为0．01mg／L、0．002mg／L变异系数(CV)分别为4．4％、5．7％该方法操作简便、分析速度快、且不受多种挥发性有机物干扰。     

毛细管柱顶空气相色谱法测定水中酮、醇、腈和吡啶污染物研究

用大口径毛细管柱顶空气相色谱法同时测定水中丙酮、醇类、丙烯腈和吡啶等有机污染物，方法简便、快速、干扰少，0.25mL顶空气体进样，检出限分别为0.005mg/L、0.012mg/L、0.009mg/L、0.003mg/L和0.015mg/L，灵敏度高于直接进水样法，可用于水和不宜直接进样分析的样品测定。     

顶空气相色谱法测定水中乙醛、丙烯醛、丙烯腈和吡啶

建立水中乙醛、丙烯醛、丙烯腈和吡啶的顶空气相色谱测定方法,经顶空进样,用HP-INNOWAX毛细管色谱柱程序升温分离,FID检测,以保留时间定性,外标法定量。水中乙醛、丙烯醛、丙烯腈和吡啶的浓度范围分别在16.0~800μg/L、16.0~800μg/L、15.4~768μg/L、80.0~4 000μg/L时,回归曲线相关系数为0.999 7、0.998 9、0.999 9和0.997 9,检出限分别为2.6、2.7、2.0和4.4μg/L。乙醛、丙烯醛、丙烯腈和吡啶分别在16.0μg/L、16.0μg/L、15.4μg/L、80.0μg/L浓度时,7次平行测定结果的相对标准差分别为5.3%、5.6%、4.3%和1.7%,样品加标回收率乙醛为92.6%、丙烯醛为92.8%、丙烯腈为99.6%和吡啶为102%。实验结果表明,顶空气相色谱法在相关系数、检出限、相对标准偏差、回收率等各方面均满足地表水环境质量标准要求,而且顶空气相色谱法前处理简单,无需使用有机溶剂,简便、快速、准确、重现性好,适合各种水体中乙醛、丙烯醛、丙烯腈和吡啶的同时测定。     

顶空-大口径毛细管柱气相色谱法测定水中乙醛、丙烯醛、丙烯腈、吡啶

建立了顶空-大口径毛细管柱气相色谱法测定水中乙醛、丙烯醛、丙烯腈、吡啶的方法,并通过实验对该方法的线性、检出限、精密度、回收率进行了检验。结果显示,乙醛、丙烯醛、丙烯腈、吡啶线性良好,相关系数为0.999 2~0.999 9,方法检出限为0.03 mg/L~0.05 mg/L,空白加标的相对标准偏差小于10%,实际样品加标回收率为89.8%~105%,表明该方法能够满足水中乙醛、丙烯醛、丙烯腈、吡啶的检测要求。     

顶空气相色谱法测定卷烟包装材料中的溶剂残留

采用顶空气相色谱法对卷烟包装材料中残留溶剂(乙酸乙酯、乙酸丁酯、甲苯、乙苯等)进行分析,讨论了各种条件对测定的影响.分析结果表明,该方法对上述4种残留溶剂的检测限范围分别为乙酸乙酯0.4~120 mg/L,甲苯0.4-120mg/L,乙酸丁酯1.2~600 mg/L,乙苯0.5~150 mg/L,测定结果的相对标准偏差为2.6%~3.1%,样品的回收率为90%~95%;用于一些卷烟包装材料中溶剂残留的分析,方法简便、快速、重现性好.     

顶空气相法测定醋中的甲醇和乙醇含量

建立一种用于食醋中可能残留的甲醇和乙醇的顶空气相色谱检测方法,并讨论了各种条件对测定的影响.方法采用氢火焰检测器检测,甲醇和乙醇能够完全分离,线性良好,方法检测限分别为8.91mg/L和7.28mg/L,6次测定的相对标准偏差分别为5.31%和3.01%,样品的加标回收率分别为96.9%～94.2%.测定了6种样品中的甲醇和乙醇含量,方法简便、快速、重现性好,基本上能满足食醋中甲醇和乙醇含量的分析.     

一体化Fenton反应器处理腈纶聚合单元生产废水

采用自主设计一体化Fenton反应器,进行了处理腈纶聚合单元生产废水的效能及影响因素研究.结果表明,一体化Fenton反应器能实现对CODcr、丙烯腈及CN-的有效去除,同时提高了废水可生化性.获得的最佳工艺参数:H2O2和Fe2+投加量分别为0.2 mol/L和28.8 mmol/L,pH值3.0,停留时间150 min.出水回流可改善处理效果,在最佳工艺条件下,出水回流比为100%时,废水CODcr质量浓度可从1 247.9 mg/L降至124.1 mg/L,去除率为90%,废水中难生物降解的低聚物被彻底去除,特征污染物丙烯腈的质量浓度从75.5 mg/L降为0,CN-的质量浓度从5.40 mg/L降至0.12 mg/L,去除率为97.8%,出水可生化性指标从0.08提高到0.36.     

气相色谱法测定水中松节油的两种方法对比

对顶空气相色谱法与液液萃取气相色谱法测定水中松节油的方法进行比较。用Varian CP-Sil 8 CB石英毛细管柱程序升温分离,FID检测,以保留时间定性,外标法定量。顶空气相色谱法的回归曲线相关系数为0.998 5,检出限为0.009 7 mg/L,相对标准偏差为2.3%~3.0%,回收率为104%~106%;液液萃取气相色谱法的回归曲线相关系数为0.998 4,检出限为0.03 mg/L,相对标准偏差为3.8%~4.3%,回收率为92%~94%。实验结果表明,顶空气相色谱法在相关系数、检出限、相对标准偏差、回收率等各方面均优于液液萃取气相色谱法,而且顶空气相色谱法前处理简单,无需使用有机溶剂,简便、快速、准确、重现性好,适合于大量样品的快速分析。     

何首乌根和茎愈伤组织的二苯乙烯苷含量

为了获得何首乌悬浮细胞系、研究何首乌细胞的液体培养和二苯乙烯苷的代谢路径,首先要获得何首乌愈伤组织.文中以何首乌根和茎为外植体,通过正交试验筛选根和茎诱导愈伤组织的适宜培养基,结果表明,在26℃和暗培养条件下,MS培养基中添加1mg/L2,4-二氯苯氧乙酸和0.4mg/L萘乙酸最适宜诱导出愈伤组织,诱导率可以达到96.7%.通过HPLC测定了根和茎愈伤组织的二苯乙烯苷含量,分别为1.5mg/g和0.4mg/g.     

聚氯乙烯车间空气中氯乙烯的顶空气相色谱测定法

用顶空气相色谱法测定聚氯乙烯车间空气中氯乙烯的含量。以流量为0.1 L/min采集空气试样1.5 L,经甲醇解吸后,顶空温度在50℃条件下平衡40 min,用气相色谱FID检测器,以OV-1毛细管柱分离测定。氯乙烯的加标回收率为97.9%~111.2%,方法最低检出浓度为0.89 mg/m3,相对标准偏差(RSD%)为4.99%。结果表明,该方法有较高的灵敏度和理想的准确度,并能达到规定的检出限,适用于工作场所空气中氯乙烯的测定。     

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-