微波消解氢化物原子荧光法测定海水蔬菜中的砷、汞

建立了一种微波消解处理样品,氢化物发生原子荧光光谱法同时测定海水蔬菜中微量砷、汞的方法.在优化的实验条件下,海水蔬菜中砷、汞回收率分别为96.0%、103.2%;检出限分别为0.24μg/L和0.17μg/L.并对方法的精密度和准确度进行评估,结果表明该方法用于海水蔬菜中砷和汞的同时测定是可行的.     

优化的原子荧光法测定砷汞含量

建立了用AFS-830双道原子荧光光度计同时测定不同样品中砷和汞的氢化物发生-原子荧光法检测方法.在优化的仪器工作条件下:砷和汞的线性检测范围广,分别为0~10μg/L和0~1μg/L;方法灵敏,检出限分别为0.042μg/L和0.038μg/L;样品加标回收率高,分别为99.5%~100.1%和97.5%~99.9%,可用于工业环境监测中测定不同样品中的砷和汞的含量.     

原子荧光光谱法测定稻谷及制品中含总砷的量

应用氢化物发生原子荧光光谱法测定稻谷及其制品中总砷,采用微波消解法对稻谷及其制品样品进行总砷的前处理.结果表明,方法检出限为0.02 mg/kg,线性范围为0~25μg/L,回收率为92.6~103.0%,相对标准偏差为0.8%.所测稻谷中总砷范围在0.126~0.526 mg/kg,糙米中总砷范围在0.096~0.174 mg/kg,大米中总砷范围在0.012~0.054 mg/kg.     

微波消解-氢化发生-原子荧光光谱法测定涂料中的砷

采用微波消解-氢化发生-原子荧光光谱法连续测定涂料中的砷,用硝酸消解样品,探讨了负高压、灯电流、原子化器温度及高度、载气流量、屏蔽气流量、硼氢化钾-氢氧化钾的浓度等的选择。本方法的线性范围为0~200?g/L,相关系数r=0.9996,检出限为0.3652μg/L,相对标准偏差RSD为1.23%,回收率为98%~104%。     

微波消解-氢化物发生-原子荧光光谱法同时测定食品中的As和Hg

应用微波消解-氢化物发生-原子荧光光谱法测定食品中微量砷(As)和汞(Hg)的含量,实验结果表明,在最佳条件下,该法的回收率分别是:砷为94.5%～101%,汞为92%～96%,相对标准偏差值为1.0%～1.66%,As和Hg的检出限分别为0.1μg·L-1和0.02μg·L-1,其线性范围分别为1.0～100μg·L-1和0.2～60μg·L-1.该法能满足各类食品中微量砷和汞含量的测定要求,具有分析速度快、操作简便、检验效率高等特点.     

石墨消解-原子荧光光谱法测定植物中的砷

建立石墨消解对植物进行前处理的方法,消解液中总砷用原子荧光光谱法测定。砷的浓度在0.00~5.00μg/L范围内与荧光强度线性关系良好,相关系数：r=0.9999,方法检出限为0.002 mg/kg。使用有证标准物质进行验证,结果在一倍标准偏差以内;相对标准偏差为3.5%。对植物样品小麦进行加标回收实验,加标回收率在90.0﹪~94.8﹪之间。实验表明：用石墨消解-原子荧光光谱法测定植物中砷的方法,操作方便、消解时间短、浓缩样品提高测量的精密度和准确度、使用成本低。适合大批量样品的测定。     

微波消解火焰原子吸收法测定中草药中痕量铅、铬、镉和镍的研究

研究了用火焰原子吸收法测定中草药中痕量铅、铬、镉和镍的方法,中草药样品采用HNO3-H2O2消化体系微波消化,然后用原子吸收光谱法测定.在最佳微波消化条件和测定条件下,检出限为0.3~0.8μg/L,测定结果的相对标准偏差为1.8%~2.4%,回收率为94%~105%,结果令人满意.     

氢化物原-子-荧光光谱法测定食品中微量砷

采用氢化物原子荧光光谱法研究了用砷化钾－硫脲作为预还原剂对测定砷的影响，讨论和确定了最佳检测条件，结果表明：该方法线性范围广，线性关系良好，r=0.9998,检出限为0.219μg/L，标准偏差为0.63%-0.85%，回收率为94．22－100.60%，该方法准确，简便，可广泛用于食品中砷的检测。     

微波消解-氢化物发生原子荧光法连续测定砷、硒、锑的研究

建立了氢化物发生原子荧光法连续测定食品中砷、硒和锑的方法.采用微波消解的方法处理样品,研究了在酸性介质下,砷、硒、锑与硼氢化钾生成氢化物的反应行为,并对影响荧光强度的诸因素进行了试验和探讨.该法砷、硒、锑的线性范围分别为0~250,0~200,0~200μg/L,检出限分别为0.36,0.42,0.31μg/L,相对标准偏差为1.23%~4.85%.该法灵敏度高,检出限低,应用于实际样品的测定,结果满意.     

原子荧光光谱法测定土壤中砷

样品采用混酸(HNO3+HClO4+H2SO4)消化,控制10%盐酸介质,以抗坏血酸-硫脲还原,用原子荧光光谱法测定。加标回收率为94.2%,相对标准偏差0.65%(n=11),检出限0.08ng.mL-1,测定土壤、水系沉积物等标准物质中砷的含量,测定结果在标称值范围内。     

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。     

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.