超声作用对马铃薯淀粉糊凝胶特性的影响

为揭示超声场对淀粉糊凝胶特性的影响,以马铃薯淀粉糊为研究对象,采用质构仪考察了不同超声场条件与不同淀粉糊浓度对马铃薯淀粉糊凝胶强度的影响．在此基础上,结合扫描电镜（SEM）分析研究了超声场中马铃薯淀粉糊微观结构的变化．研究结果表明：马铃薯淀粉糊经超声作用后,所形成凝胶的凝胶性质有显著变化;随着超声作用时间的延长和声强的增加,所形成凝胶的凝胶强度降低,且淀粉糊浓度越小,凝胶强度下降的程度越显著．超声场对马铃薯淀粉糊凝胶强度的影响主要在于超声会引起淀粉糊微观结构的变化,超声作用前马铃薯淀粉糊的网络结构完善,因此凝胶性质较好;超声作用后马铃薯淀粉糊的微观结构较为松散,组织呈团状聚集,故凝胶性质较差．     

双频超声强化对三七总皂苷提取的影响

采用双频超声（40kHz／25kHz）技术对三七总皂苷提取进行强化,选择乙醇质量分数、料液比、超声作用时间及提取温度因素进行正交试验,得出影响总三七总皂苷提取率的大小次序先后为：乙醇质量分数〉超声作用时间〉料液比〉提取温度,优选出双频超声提取最佳工艺条件：质量分数为80％的乙醇,超声作用时间为30min,料液比为1：20,提取温度为40℃．在这个最佳条件下试验,三七总皂苷提取率为82．41％．采用碘化钾溶液中碘的释放量来研究超声空化事件。结果表明：在相同的超声电功率下,双频超声释放碘的量远大于单频25kHz超声和单频40kHz超声释放的碘。     

超声作用下马铃薯淀粉糊的凝胶特性

为揭示超声作用下淀粉凝胶特性的变化规律,以马铃薯淀粉糊为研究对象,采用质构仪测量了不同超声场条件及淀粉糊浓度下马铃薯淀粉凝胶强度的变化规律。在此基础上,结合扫描电镜（SEM）分析研究了超声场中马铃薯淀粉糊微观结构的变化。研究结果表明：超声作用于马铃薯淀粉糊后,其所形成凝胶的凝胶性质有显著变化,随着超声作用时间和声强的增加,马铃薯淀粉糊形成的凝胶强度降低,且淀粉糊浓度越小,凝胶强度下降的程度越大;超声场对马铃薯淀粉凝胶强度的影响主要在于其所引起的淀粉糊微观结构的变化,超声作用前马铃薯淀粉糊的网络结构完善,因此形成的凝胶性质较好;超声作用后,马铃薯淀粉糊的微观结构较为松散,组织呈团状聚集,其凝胶性质较差。     

渗透脱水循环处理对糖液及桃片理化特性的影响

以白桃片为实验材料,追踪分析了单阶段(糖液浓度不变)和多阶段(糖液浓度逐渐增加)渗透脱水循环处理后糖液特性和桃片理化特性的变化。糖液循环利用5次,期间不做任何调整。结果表明:随着糖液循环利用次数的增加,单阶段渗透脱水处理过程中糖液黏度降低、稀化现象严重,导致渗透压力差减小,使桃片水分损失率和固形物增加率逐渐降低,同时桃片中可溶性物质的溶出致使糖液电导率、浊度、色差值显著增加；多阶段渗透脱水循环处理基于多浓度糖液组合利用,有效降低了循环利用过程中糖液稀化现象的发生,保持了较好的渗透压力差,进而有利于桃片更多固形物的获得和更多水分的散失,且糖液的电导率、浊度等特性得到了较好的保持,但是多阶段渗透脱水循环处理会使桃片与空气接触更多,不利于产品色泽的保持,且长时间的高渗透压导致桃片中可滴定酸含量显著改变。从糖液循环利用中桃片渗透脱水效率和糖液特性保留角度出发,多阶段渗透处理可在桃片渗透方式的选择上提供一种新颖的思路,具有良好的应用前景。     

超声场对毛细管内电解质浸出过程的影响

为探讨超声场强化化工分离过程的机理 ,以充满电解质溶液的短毛细管中溶质的浸出模拟固液分离体系 ,通过测定浸出动力学曲线 ,探讨了超声场对这一浸取过程的强化作用机理 ,分析了微扰效应对传质过程的影响。实验结果表明 ,超声空化的微扰效应强化了溶质在毛细管内部的扩散 ,且强化作用随毛细管径及超声场强的增大而增大。与升温的强化效果相比较 ,超声场的微扰效应和湍动效应兼顾了强化内外扩散的两个方面 ,与升温浸取过程相比 ,超声场的强化手段更具优势     

医用甘油溶液的声空化研究

利用电功率50W，正弦28kHz的超声空化作用，使在医用甘油溶液中获得了直径约10μm，持续时间大于2min，浓度超过10^5个／ml的声振微泡。     

用三种方法研究双频超声空化增强效应

分别使用TA荧光法、碘释放法和电学法对28kHz分别与1．04MHz和1．7MHz组成的双频超声辐照系统的空化增强效应进行了研究．结果表明，双频超声辐照能明显增强空化效应，其声空化产额均显大于各频率单独辐照方式的声空化产额之代数和．对双束超声空化增强效应的机理从3个方面进行了分析：(1)双频辐射增强样品的机械振动，有助于更多的空气经液体表面进入液体而导致空化核增加；(2)在双频超声作用下，各自产生空化过程，当各自空化内爆时，会产生许多新的空化核，这些空化核为另一频率的空化提供了更多与其共振频率接近的空化核；(3)由于气泡在低频负压相内准静压力减小，从而降低丁空化的阀值．而在低频的正压相内，气泡的内爆强度增加，因而提高了其声空化产额．     

超声波强化提取牡丹花黄酮

采用超声波技术对牡丹花黄酮提取进行强化，选择超声频率、乙醇浓度、超声时间、物料比为因素进行正交实验，优选出超声提取最佳工艺：即以70％的乙醇，料液比为1：20，在频率为22kHz的超声波下处理10min，提取率可达91．5％。具有提取效率高，提取时间短，温度低的优点。     

超声空化场的致热机制及其聚束喷射时的致热速率

分析表明，超声空化泡崩溃时的高温冲流作高压冲击波是使塑料致热熔融的机制。采用圆锥形和圆柱形玻璃管对单束超声空化场聚束喷射时，致热速率明显加大，这是因为空化泡在声辐射压力作用下聚集于喷射空化场前峰区的密度得以提高，因而增强了空化集中的致热效果。     

超声空化场的致热机制及其聚束喷射时的致热速率

分析表明,超声空化泡崩溃时的高温声冲流和高压冲击波是使塑料致热熔融的机制.采用圆锥形和圆柱形玻璃管对单束超声空化场聚束喷射时,致热速率明显加大,这是因为空化泡在声辐射压力作用下聚集于喷射空化场前峰区的密度得以提高,因而增强了空化集中的致热效果.     

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.     

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.     

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.     

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.     

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.     

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