氧弹燃烧-离子选择性电极法测定豆类中的钙

采用氧弹燃烧-离子选择性电极法测定了豆类中的钙含量.首先对pCa-1-01型钙离子选择性电极的性能进行测试,此电极对钙离子浓度在0.1¹00 mmol·L-1范围内有较理想的能斯特响应,斜率为-29.33mV/pCa(25℃);然后用氧弹燃烧技术对样品进行预处理,酸液吸收燃烧所得产物;最后在样品液中加入离子强度调节溶液KCl及pH值为10的NH4Cl-NH3·H2O缓冲溶液后定容,用钙离子选择性电极测定溶液的电动势,再计算不同豆类中钙的含量.结果表明,黄豆中钙的含量最高,花豇豆中钙的含量最低,回收率为96.12%100 mmol·L-1范围内有较理想的能斯特响应,斜率为-29.33mV/pCa(25℃);然后用氧弹燃烧技术对样品进行预处理,酸液吸收燃烧所得产物;最后在样品液中加入离子强度调节溶液KCl及pH值为10的NH4Cl-NH3·H2O缓冲溶液后定容,用钙离子选择性电极测定溶液的电动势,再计算不同豆类中钙的含量.结果表明,黄豆中钙的含量最高,花豇豆中钙的含量最低,回收率为96.12%⁹8.06%,相对标准偏差在0.44%98.06%,相对标准偏差在0.44%¹.19%之间.     

一种用于氟离子可视化检测的荧光探针

丙二腈与6-羟基-2-萘甲醛反应合成2-(6-羟基萘-2-亚甲基)丙二腈(探针1),并将其作为荧光探针用于检测氟离子.在测试体系中,探针1的二甲基亚砜(DMSO)溶液为浅黄色,几乎没有荧光;加入氟离子后,溶液颜色立刻变为粉红色,且溶液显示蓝色荧光;而加入其他阴离子,溶液未显示荧光.研究还发现探针1对氟离子具有较强的选择性和较高的灵敏度;Job's法得出探针1与氟离子之间的配比为1:1;核磁滴定结果表明加入氟离子后,探针1上的酚羟基发生去质子化反应;分子轨道理论计算得出,探针1去质子化后HOMO-LUMO能级差增大,明显改变了溶液颜色和荧光光谱.     

试样加入法-离子选择性电极测定氟

建立了一种离子选择性电极法测定高浓度氟的新方法.该方法在体积为100.0 ml、浓度为1.000×10-4 mol/l的标准溶液中加入1.000 ml高浓度试样,加入前后测定其电动势,由这两个电动势和溶液体积计算试样的含氟量.10次测定的标准偏差S小于0.004,相对标准偏差RSD小于4%,3个水平、6次测定的回收率在95.0%～101%之间.     

试样加入法-离子选择性电极测定氟

建立了一种离子选择性电极法测定高浓度氟的新方法.该方法在体积为100.0 ml、浓度为1.000×10-4 mol/l的标准溶液中加入1.000 ml高浓度试样,加入前后测定其电动势,由这两个电动势和溶液体积计算试样的含氟量.10次测定的标准偏差S小于0.004,相对标准偏差RSD小于4%,3个水平、6次测定的回收率在95.0%～101%之间.     

离子色谱法同时测定白炭黑中的氟离子和氯离子

通过对市售白炭黑的纯水浸取液进行离子色谱分析,鉴定出氟离子和氯离子,并在此基础上建立了白炭黑中微量氟离子和氯离子的同时定量方法.在优化实验条件下,白炭黑在硫酸钠稀溶液中磁力搅拌30min,浸取液经滤膜过滤后由离子色谱分析.氟离子和氯离子的线性范围分别是0.01～10和0.005～10mg·L~(-1),其定量限分别为0.57和0.19mg·kg~(-1).白炭黑中的氟离子和氯离子质量分数分别为5.2～10.8和3.6～13.2mg·kg~(-1),二者的加标回收率均在91.2%～116.0%之间.实验结果表明,该方法灵敏、简便,可为白炭黑中微量氟离子和氯离子的测定提供实用可靠的方法.     

双离子液体富集结合原子吸收测定植物中痕量锂

分别以憎水性离子液体1,3-二辛基咪唑六氟磷酸盐、亲水性离子液体溴化1-丁基-3-甲基咪唑和4-甲基-10-羟基苯并喹啉作为萃取介质、缔合剂和螯合剂,建立双离子液体锂绿色萃取分离新体系。在氢氧化钠溶液中,锂离子可与4-甲基-10-羟基苯并喹啉和1-丁基-3-甲基咪唑阳离子发生反应,生成稳定的螯合-离子缔合物而被萃取进入憎水性的离子液体相;加入硫酸钠可将此缔合物迅速分解使锂离子重新回到水相。最佳条件下,锂的一次萃取率和反萃率分别为95.5%和99.8%,富集倍数超过50倍。研究表明,1,3-二辛基咪唑六氟磷酸盐经过20次锂的萃取和反萃,其萃取率仍保持在99.1%以上,说明离子液体具有良好的重复利用性。双离子液体绿色萃取结合原子吸收光度法已成功应用于植物中超痕量锂的检测,方法的检出限为0.1μg/g,加标回收率在97.0%～102.5%。     

冷酸解离氟电极法测定牙膏中的氟含量

探讨了冷酸解离氟电极法测定牙膏中氟的含量,在冷硝酸介质中牙膏中氟解离效果最佳。讨论了总离子强度调节缓冲剂TISAB的组成及用量、溶液的PH值、加氟标液用量对准确度的影响等。实验结果表明：TISAB（I）用量在20%,溶液PH值在5.0～7.0范围时,氟离子浓度在10-2-10-6mol/L范围内,具有良好的线形关系。回归方程：E=-50.9PF-57.6,相关系数R=0.9995。加入0.50 ml0.01mol/L的氟标液加标回收率为104.1%。     

沉淀-吸附法制备高纯酯型儿茶素

用ZnCl2作沉淀剂,当溶液pH值为5.6～6.5时,将茶叶浸提液中的儿茶素以金属盐的形式沉淀,沉淀物经洗涤后,用质量分数为40%的硫酸溶解,然后将溶液直接加入聚酰胺树脂柱上,先用蒸馏水将Zn2+,Na+等无机离子除去,再用乙醇将茶多酚洗脱,洗脱液经浓缩、干燥,得到纯度高于99%的高纯酯型儿茶素,提取率达10.2%,其中EGCG,GCG,ECG含量分别为64%,16%和19%,金属离子含量小于1×10-3%,未检出咖啡因.     

新型氟离子吸附剂活性二氧化钛除氟的研究

选用活性二氧化钛作为氟离子吸附剂，用于地下水及工业废水除氟。当活化时间为1h，酸度在pH2.00～10.00范围内，在50mL,10mg/L氟离子溶液中，加入0.1g活性二氧化钛，可使氟离子浓度下降到1.0mg/L以下，达到饮用水含氟标准。     

一种对铜离子进行裸眼识别的新型萘酐化学传感器的合成及性质研究

设计、合成一种新型萘酰亚胺与香豆素偶联的铜离子化学传感器1.通过1H NMR,13C NMR,IR,ESI-MS等表征该物质的化学结构,通过UV-vis吸收光谱研究该分子的光谱性质.结果表明:该分子在DMSO-H2O(体积分数为1∶1)溶液中加入铜离子,传感器分子通过与铜离子络合导致溶液颜色从黄色变成橙黄色.不仅最大吸收波长有较明显地红移且其吸收强度也增强,而加入其他离子(Al3+、Ca2+、Cd2+、Ba2+、Hg2+、Sr2+、K+、Mn2+、Co2+、Ni2+、Ag+、Mg2+、Li+、Pb2+、Zn2+)均没有明显变化,该传感器具有专一性好、灵敏度高、检测迅速且铜离子而不受其他离子的干扰.1     

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.     

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。     

A computer generator for randomly layered structures

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

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.     

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that