中药注射液热稳定性的研究--荧光光谱法

本文采用荧光光谱法对中药注射液热稳定性进行了探讨 研究表明70℃恒温条件下,不同中药注射液的荧光光谱和荧光强度随时间呈现出各自的规律性变化 本文通过对图谱和荧光强度的分析,揭示出中药注射液在受热条件下,组分和浓度随时间而变化的特点     

超声空化强度的化学计量表征方法

以对苯二甲酸(TA)和亚甲基蓝(MB)为羟自由基捕捉剂,采用荧光分析法和紫外-可见光分光光度法分别探究了超声辐照时间、频率、功率对超声空化强度的影响,最佳工艺条件均为80,W和40,k Hz,超声空化强度随时间呈线性变化.实验对比分析了这两种化学计量方法,其中荧光分析法更能精确表征固液体系的空化场强度.结果表明,一定固体颗粒的存在会增强空化效应,同时固体颗粒会影响声场和流场,导致测量温度范围(20~80,℃)内体系最优值由60,℃变为40,℃.     

高性能混凝土高温后劈裂抗拉强度试验研究

在不同温度相同恒温时间以及相同温度不同恒温时间两种情况下对C40高性能混凝土立方体试件的劈裂抗拉强度进行试验研究,分析讨论了不同高温作用后混凝土材料劣化的机理以及对劈裂抗拉强度的影响,探讨了劈裂抗拉强度随温度变化的规律。结果表明,高温后对混凝土的劈裂抗拉强度影响最大的因素是作用的最高温度,在相同的恒温时间条件下,C40高性能混凝土的劈裂抗拉强度随着经历温度的升高总体呈下降趋势;在相同的试验温度条件下,混凝土的劈裂抗拉强度随着试验时间的延长会出现反弹现象。     

hPin1原核表达、纯化及热稳定性研究

利用E．coli BL21原核表达,纯化得到了His-hPin1融合蛋白,并研究了它的热稳定性．在中性条件下进行不同温度处理,SDS-PAGE分析表明,低于40℃处理不会影响His-hPin1的溶解性,50～100℃处理会使其部分变性而沉淀．荧光发射光谱研究表明,未处理的His-hPin1具有339nm的荧光发射峰;热处理使荧光发射峰的位置变化,低于40℃处理对His—hPin1的荧光强度影响较小,50～100℃热处理使HiS-hPin1的荧光强度明显降低．圆二色谱研究表明,热处理对His-hPin1的二级结构有影响,引起α-螺旋含量的明显减少,而无规卷曲增加．以上数据表明hPin1是一个相对热稳定的蛋白．     

高温下碳纤维-混凝土界面受剪性能试验研究

分别在4,40,60,80,100,120,140,160,180℃下进行碳纤维-混凝土界面的剪切试验,研究了不同温度下界面破坏形式、温度对胶体及碳纤维的影响,以及黏结强度随温度的变化规律,初步建立了不同温度下的黏结应力-滑移关系.试验结果表明,40℃时的界面黏结强度高于其他温度;40℃后黏结强度随温度升高而降低;温度超过100℃后,黏结强度基本趋于稳定.     

加热对三黄鸡胸肉嫩度、质构及微观结构的影响

以与肉类品质密切相关的特性为指标,探讨了加热对三黄鸡胸肉中这些指标的影响,并对其变化趋势进行了讨论.结果表明:鸡胸肉蒸煮损失在65 ～ 85℃间及80℃加热5～10 min内显著增加;随温度升高,鸡胸肉剪切力值(SFV)呈4段式变化,80℃加热10 min后SFV开始增加,40 min后达到最大;肉的质构参数随温度和时间的变化趋势不同;随温度升高,肌纤维直径先减小,至65℃达到最小值后逐渐增大;在75℃及以上时,肌内膜和肌束膜逐渐崩溃,肌纤维间隙逐渐减小,95℃时肌纤维排列紧实;55 ～ 85℃之间上述特性变化显著,不同温度下肌纤维结构及结缔组织膜的综合变化对鸡肉蒸煮损失、SFV及质构参数有显著影响.     

生物油/生物柴油混合燃料的热稳定性

为了考察生物油/生物柴油混合燃料的热稳定性,分析了该混合燃料在不同的存储温度和存储时间下组分物化性质的变化,并测试了存储前后该混合燃料的黏度、水分含量、酸度、平均分子质量等理化特性.实验结果表明:当存储温度为80℃,存储时间为180 h时,样品的含水量小于0.7%;黏度随存储温度的升高和存储时间的延长变化不大.利用FT...     

温度和土壤湿度对弯齿琵甲卵发育影响的初步研究

将弯齿琵甲(BlapsfemoralisFischer Waldheim)卵分别置于4种温度(恒温30℃,25℃,20℃,室温20～27.5℃)与5种RH水平(0.00%,5.83%,11.66%,17.49%,23.32%)交叉的20种处理组合中,并测定其孵化率.结果表明,在变温20～27.5℃,RH为16.80%(平均)的条件下,卵孵化率最高,为68.3%;在恒温25℃,RH为11.04%(平均)的条件下,卵孵化率较高,为36.7%;RH在5.42%～22.61%间为适湿区,随温度的上升,对最适RH值的要求也上升;变温与恒温对卵的孵化有差异,在适宜温度范围内的变温可明显提高孵化率.5种恒温(32℃,30℃,28℃,25℃,20℃)处理表明,卵在20～32℃间的发育速率与温度均呈直线关系,卵的发育起点温度为(11.60±0.60)℃,有效积温为(146.97±12.31)日度.     

恒温时间对PCD复合片高频感应钎焊性能影响研究

采用AgZnCuMnNi钎料高频感应钎焊聚晶金刚石复合片(PDC)与硬质合金,研究了690℃钎焊温度下不同恒温时间对其钎焊性能的影响.利用扫描电镜、电子探针、X射线衍射仪等对钎缝界面和聚晶金刚石(PCD)层的热损伤进行了分析,并测试了钎缝抗剪强度.结果表明:钎缝内主要存在Ag基固溶体、Cu基固溶体、Cu0.64Zn0.36相和少量MnNi相,恒温时间15s时,含Cu基固溶体、Cu0.64Zn0.36相和MnNi相的灰黑色晶粒对钎缝起到弥散强化作用,钎缝抗剪强度达最大值350.6MPa;随着恒温时间的延长,灰黑色晶粒平均等积圆直径逐渐变大,钎缝边界形成连续金属间化合物层,抗剪强度下降;PCD层的热损伤随钎焊中恒温时间的延长而加剧,生产中应采用较短的恒温时间.     

高温高压条件下甲烷和二氧化碳溶解度试验

根据不同温度和压力条件下测得的甲烷和二氧化碳两种气体在碳酸氢钠型水中的溶解度数据,对两种气体的溶解度与温度、压力及地层水矿化度之间的关系进行研究。结果表明:在地层水中的溶解机制不同,导致两种气体的溶解度值随温度、压力条件的变化具有不同的演变特征;综合前人低温(小于90℃)测试的溶解度数据,可将甲烷溶解度与温度之间的演变关系划分为缓慢递减(0~80℃)、快速递增(80~150℃)和缓慢递增(大于150℃)3个阶段;二氧化碳溶解度随温度的升高而逐渐降低,随压力升高而逐渐增大,其溶解与析离能力受压力影响更为明显;实际地层中,两种气体间溶解度的差异演变影响了天然气的空间分布。     

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