从柑桔皮中连续提取色素、果胶的工艺研究

实验研究了以柑桔皮为原料,用乙醇浸提色素,酸水解乙醇沉淀法提取果胶方法。最佳条件：pH1．5,温度80℃,时间2h。果胶得率13．88％。     

西瓜果胶提取工艺研究

果胶属多糖类高分子化合物,作为添加剂广泛应用于食品、医学和精细化工领域.原果胶不溶于水,但在酸、碱、盐或酶的作用下,可水解转化,成为水溶性果胶.基于果胶的这一特性,人们已从富含果胶的橙、柑桔等水果的果皮中提取分离出天然果胶.     

二次酸水解法从黄姜中提取薯蓣皂甙元的工艺

薯蓣皂甙元是合成甾体激素药物和甾体避孕药物的重要原料，是黄姜中的主要活性物质。采用正交实验的方法，探讨了经过二次酸水解法从黄姜中提取薯蓣皂甙元的工艺条件，结果表明该方法提取的薯蓣皂甙元产率达到了2．41％，比直接水解法（2．20％）提高了9．55％。另外，采用熔点、元素分析法、红外、核磁等一系列的手段对产品进行表征，结果表明该法是可行的，提取的薯蓣皂甙元的质量纯度达到了工业的要求。     

从柑桔皮中提取果胶的研究——优化工艺条件探讨

以柑桔皮为原料，采用酸法提取、真空浓缩、乙醇沉淀工艺提取果胶；优化工艺条件为：水料比为20：1、pH值为2．1、提取温度为75℃、提取时间为60min，真空浓缩后体积约占原液的10％，混合后乙醇浓度约为50％；按最后确定的提胶工艺方案做了试验，结果为：20g干柑桔皮产果胶3．58g，产率为17．9％；实验表明：所选工艺条件是可行的，果胶质量符合要求，其产率也是理想的，对果胶生产有重要意义。     

硫酸催化蔗髓半纤维素的水解条件研究

用硫酸作催化剂水解蔗髓木质纤维素,考察不同催化剂用量、水解液固比、水解时间以及温度对蔗髓水解生成木糖、葡萄糖、阿拉伯糖和糠醛的影响。结果确定出蔗髓稀酸水解处理的最佳水解条件是:催化剂用量130%、液固比20、水解温度120℃,时间20min,在此条件下,木糖产率23.06%,葡萄糖产率1.97%,阿拉伯糖产率0.85%,糠醛产率2.34%。     

从提取淀粉后的蕉藕残渣中提取果胶的最佳工艺

为提高资源的利用率,采用酸解法试验研究了从提取淀粉后的蕉藕残渣中提取果胶的最佳工艺,并对其进行定性分析。通过料液比、料浆pH值、提取时间和提取温度等单因素实验和L9(34)正交试验,得到了提取果胶的最佳工艺为:提取温度80℃,提取时间1.5 h,料浆pH 4.0,料液比1∶20(g/mL),此条件下果胶产率为7.72%。     

从柑桔皮中提取果胶的研究--优化工艺条件探讨

以柑桔皮为原料,采用酸法提取、真空浓缩、乙醇沉淀工艺提取果胶;优化工艺条件为水料比为201、pH值为2.1、提取温度为75℃、提取时间为60min,真空浓缩后体积约占原液的10%,混合后乙醇浓度约为50%;按最后确定的提胶工艺方案做了试验,结果为20g干柑桔皮产果胶3.58g,产率为17.9%;实验表明所选工艺条件是可行的,果胶质量符合要求,其产率也是理想的,对果胶生产有重要意义.     

用羽毛提取混合氨基酸

采用硫酸水解家禽羽毛提取混合氨基酸,研究了硫酸浓度,用量,反应温度,反应时间,催化剂等因素对羽毛水解反应的影响,确定了提取氨基酸的最佳工艺条件,硫酸浓度为30％,用量300mL,反应温度为105℃,催化剂为10g,反应时间为4h,羽毛水解氨基酸的产率可达90％。     

毛樱桃果胶的提取及含量测定

目的探讨毛樱桃果浆中果胶的提取工艺及含量测定,考察不同条件对果胶提取的影响.方法采用酸性水解乙醇沉淀法制取果胶;采用正交设计L_9(3~3)方法优化毛樱桃果胶的提取工艺;采用咔唑比色法测定其果胶含量.结果优选的毛樱桃最佳工艺条件:料液比为1∶6,提取温度为90℃,提取时间为2 h,毛樱桃果浆中果胶含量为4.613%.结论毛樱桃提取果胶具有可行性.     

从向日葵花盘中提取果胶的研究

研究了从向日葵花盘中提取果胶的方法，以磷酸与盐酸的混合酸为萃取酸，以３价铁盐为沉淀剂，提取果胶的最高产率为１６．１％。     

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。     

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