高效液相色谱测定废水中的苯酚

建立苯酚及其降解产物（邻苯二酚,间苯二酚,对苯醌）的高效液相色谱分析方法,用甲醇：水为50：50作流动相,在25℃以0．5ml／min的流速进样分析．线性范围为2-10mg／L,采用外标法定量,苯酚及其降解物的相对标准偏差和回收率分别为0．4％．1．6％和95．3％．101．6％,检出限为0．0735-0．1298mg／L．该方法准确,高效,适用于苯酚及其降解产物的分离测定．     

不同流加发酵方式对重组枯草芽孢杆菌生产维生素B2的影响

在5 L发酵罐中培养重组枯草芽孢杆菌RH33生产核黄素,该重组菌的染色体上含有多个解除了转录调节的核黄素操纵子．由于过高的初糖浓度导致严重的代谢溢流,因此间歇发酵过程只能得到较低的菌体量和产物产量．分别采用了3种不同的流加培养方式：分批流加、恒速流加和葡萄糖限制流加来减弱代谢溢流并提高核黄素的产量．同间歇培养相比,分批流加培养能微弱提高重组菌的核黄素产量,而恒速流加和葡萄糖限制流加均能显著提高菌体量和核黄素产量．对于恒速流加培养,当流加速率为0．48 mL／min时核黄素产量和菌体量可以分别达到9．8g/L和27．3g/L对于葡萄糖限制流加培养,通过人工控制葡萄糖流加速率使培养基中的葡萄糖浓度为10～2 g/L时,重组菌RH33可以达到最高的核黄素产量和菌体量(分别为12．5g/L和34．7g/L)．在葡萄糖限制流加培养中核黄素产率约为0．06 g(核黄素)／g(葡萄糖),高于其他几种培养方式．     

核黄素的光电化学性质及其应用

基于核黄素的光化学和电化学性质,通过探讨核黄素的光致还原反应机理,将核黄素的光致还原与其产物的电极反应纳入一个光电化学过程,发展了一种新的核黄素光致电化学分析法．在pH4．5的醋酸盐缓冲溶液中,以EDTA 为光还原剂,在峰值波长为450 nm、能量为15 mW／cm2的光照下,在偏压0 V 处测得的光电流与5．00×10－10～5．00×10－5 mol／L核黄素浓度的对数值成正比,灵敏度为3．00×10－10 mol／L （S／N＝3）．将该方法分别应用于多合维生素、小米中核黄素的测定,显示相对标准偏差小于7．86％,加标回收率为96％～105％．与其他测定核黄素的方法相比,本方法具有测量范围宽、灵敏度高、仪器设备简单、实验操作简便的优点．     

羟胺-乙二胺-钴(Ⅱ)显色体系与甲醛质量浓度测定的研究

采用正交试验法研究了羟胺-乙二胺-钴(Ⅱ)的显色体系与甲醛反应的最佳条件．最 佳条件为5．00×10-2 mol／L羟胺溶液2．00 mL,1．00×10-1 mol／L乙二胺溶液3．0 mL,2．00×10-1 moL／L钴(Ⅱ)溶液5．00 mL,0．200 mol／L硫酸溶液0．80 mL,加热温度为55℃,加热时间为6 min．甲 醛质量浓度在0．080-3．200μg／mL范围内线性关系良好,检测下限为0．061 0 μg／mL,线性相关系数 为0．998 7．该法可用于饮用水加标回收率实验及脲醛树脂中的游离甲醛质量浓度检测．     

RP-HPLC法测定甘辛喷雾剂中甘草酸的含量

应用反向高效液相色谱法测定了甘辛喷雾剂中甘草酸含量，流动相为甲醇：0．2mol／L醋酸铵：冰醋酸(67：33：1)，紫外检测波长为250nm。结果表明：甘草酸在0．04～0．5μg／mL范围内线性关系良好，r=0．9999，平均加样回收率为100．67％。此法简便稳定、快速准确，空白无干扰，适用于该制剂质量控制中测定甘草酸的方法。     

诺卡氏菌对养殖水体中氨氮的降解特性研究

应用诺卡氏菌Nocardia对影响氨氮降解的各种主要因素进行了研究,发现降解菌在30℃,pH7．2及氨氮初始浓度0～30mg／L范围内保持高活性,最大降解速率达3．5mg／L·h。当底物浓度大于50mg／L时,平均降解速率线性下降。当接种量(菌悬液／反应液)为20mL/100mL时氨氮的降解是高效与经济的。     

5─Br─DMPAP分光光度法测定微量铑

用5－Br－DMPAP作显色剂，表面活性剂CTMAB作增溶剂，采用分光光度法测定微量锗。结果表明：方法的线性范围为：2．5～25．0μg／25mL，表现摩尔吸光系数为7．97×104L．cm－1．mol-1，变异系数为3．5％，回收率为99．6％。     

UV／O3处理有机溶剂中4，4＇-二溴联苯

采用紫外光（UV）、O3和UV／O3方法降解4，4＇-二溴联苯（4，4＇-DBB），考察了溶液pH、4，4＇-DBB初始质量浓度对降解效果的影响，探讨了降解机理，并采用GC／MS对降解产物进行了分析．结果表明：4，4＇-DBB的主要降解产物为4-溴联苯和联苯；3种方法对4，4＇-DBB都可以达到一定的去除效果，UV／O3降解效果最好，0．5g/L4，4＇-DBB溶液UV／O3作用8h后4，4＇-DBB的去除率达到91．3％．动力学分析表明，4，4＇-DBB在正己烷中的光化学反应为准一级反应，是一个逐步脱溴的反应过程．     

氢化物发生一原子荧光光谱法测定饮用水中锡

应用氢化物发生一原子荧光光谱法测定饮用水中锡，此法准确度、精密度令人满意。实验选定最佳工作条件：载气400mL／min，屏蔽气800mL／min，灯电流600mA，负高压一320V。方法检出限为0．34μg／L线性范围为(0—40．0)μg／L。目前测定饮用水中的锡国家还没有制定标准检验方法，本的工作可为饮用水中锡的标准检验方法的制定做些探索。     

散偏口服液中阿魏酸的含量测定

采用HPLC法、C18柱，以甲醇-1％冰醋酸溶液(30：70)为流动相，检测波长为313nm，对散偏口服液中阿魏酸的含量进行测定，结果表明，阿魏酸在0．996～49．80mg／L范围内线性良好，r=0．9999，平均回收率为96．96％，RSD为2．13％．该方法精确、稳定、快速方便，适于该复方制剂的质量控制．     

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。     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the