PEG催化氧化法合成对硝基苯甲酸

研究了聚乙二醇(PEG—600)作为相转移催化剂催化KMnO4氧化对硝基甲苯合成对硝基苯甲酸的反应,考察了相转移催化剂用量、反应温度、反应时间、KMnO4用量和反应体系酸碱性对反应的影响.PEG—600用量为反应底物摩尔数的5%,KMnO4与对硝基甲苯摩尔比为3∶1,反应温度为95℃,反应时间为3 h,在中性条件下进行反应,产物收率达51.6%.实验表明,PEG—600对于KMnO4氧化对硝基甲苯合成对硝基苯甲酸的反应是一种优良的相转移催化剂.     

对硝基苯甲酸乙酯的合成

为优化对硝基苯甲酸乙酯的合成工艺,考察了5种不同催化剂对其收率的影响,发现以硫酸氢钾为催化剂产率最高,并对影响产率的诸因素进行了考察,得出最佳反应条件为:对硝基苯甲酸0.015 mol、催化剂用量0.40 g、醇酸摩尔比4:1、反应温度84～85℃、反应时问2.5 h,催化酯化反应产率高达99.53%.     

对叔丁基苯甲酸甲酯的硫酸钛催化反应研究

采用硫酸钛作催化剂,以对叔丁基苯甲酸和甲醇为原料直接酯化,对对叔丁基苯甲酸甲酯的合成工艺进行了研究,着重考察了催化剂用量、反应时间、醇酸摩尔比、带水剂用量等因素对反应收率的影响,并优化反应条件。当甲醇与对叔丁基苯甲酸的摩尔比为8∶1时,在催化剂硫酸钛(用量为对叔丁基苯甲酸的20%)作用下,加入带水剂苯12 mL,于回流温度下反应6h,产品收率可达86.6%。     

季铵盐A-1催化合成邻硝基苯甲酸

研究了季铵盐A-1催化高锰酸钾氧化邻硝基甲苯,合成邻硝基苯甲酸的反应,考察了不同相转移催化剂的催化活性、催化剂用量、反应温度、反应时间、KMnO4用量和反应体系酸碱性对反应的影响.在优化反应条件下,即以季铵盐A-1为相转移催化剂,高锰酸钾与邻硝基甲苯的量比为2.5∶1,反应温度为95℃,反应时间为3h,在中性条件下进行反应,产物收率可达95%.实验结果表明,季铵盐A-1对于高锰酸钾氧化邻硝基甲苯合成邻硝基苯甲酸,是1种优良的相转移催化剂.     

用臭氧氧化对硝基甲苯制备对硝基苯甲酸

以冰醋酸为溶剂，醋酸钴—溴化钾作为复合催化剂，在常压下用臭氧—空气混合气体氧化对硝基甲苯制得了对硝基苯甲酸，反应温度为95℃，反应时间4—5h，气体流量为30L／h，臭氧体积分数为1．0％，催化剂质量分数7．1％，底物对硝基甲苯质量分数为12％，母液可循环使用，对硝基苯甲酸总收率为93％。     

NHPI/MnSO4催化氧化对硝基甲苯制对硝基苯甲酸

本文报道了以N 羟基邻苯二甲酸亚胺（NHPI）/MnSO₄为催化剂,冰乙酸为溶剂,氧气为氧化剂,催化氧化对硝基甲苯制对硝基苯甲酸,并对反应条件进行了研究,对硝基甲苯的转化率和对硝基苯甲酸的产率分别达到91.3%和82.5%,应用前景较好。     

芳烃溶剂法合成对硝基苯甲酸的研究（Ⅰ）：合成对硝基苯 …

以芳烃为溶剂，在自制催化存在下用空气氧化对硝基甲苯合成了对硝基苯甲酸，并对反应条件进行了研究，实验结果表明，对硝基苯甲酸收率可达９４．５５％，母液可以多次直接循环使用。     

相转移催化氧化合成对硝基苯甲酸

考察了以KMnO4为氧化剂,相转移催化氧化合成对硝基苯甲酸的有关影响因素．结果表明十六烷基三丁基溴化磷的催化效果最好,收率达76.6％;以价廉易得的季铵盐A-1为氧化剂,能进行缓和反应,且收率提高,达74.3％．此外,KMnO4的自身分解严重影响它对底物的氧化作用,由此确定反应以在中性介质中发生为宜．     

废旧塑料泡沫微波法制备对硝基苯甲酸

废旧塑料泡沫(PSF)作为一种白色污染,其处理、回收和利用一直是社会关注的问题.以废旧泡沫为原料,在催化剂的作用下,成功通过微波手段使废旧泡沫转化为高附加值的精细化工产品--对硝基苯甲酸(PNBA).探讨了各因素对硝基苯甲酸产率的影响.在HNO3质量分数为73%,HNO3与PSF质量比为9.5∶1,反应温度200℃,反应压力2MPa,碱金属盐组合催化剂质量分数为0.1%,反应时间为60min的条件下,PNBA产率达到最大80%,产品纯度为99.2%.     

微波辐射和相转移催化合成β-甲基-β-硝基对甲氧基苯乙烯

在微波辐射和相转移催化剂的条件下，采用Henry反应，快速合成β—甲基—β—硝基对甲氧基苯乙烯．考察了微波辐射功率、微波辐射时间、不同的相转移催化剂、反应物的物料比等因素对反应收率的影响．结果表明：在微波辐射功率为130w、微波辐射时间为8min，以PEG—1000做相转移催化剂，反应物的用量为：对甲氧基本甲醛：硝基乙烷：PEG—1000为1：2．5：0．08．在冰乙酸／醋酸铵条件下，产物收率达48．9％。     

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.     

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