刺松藻抑菌活性成分初步研究

以金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、铜绿假单胞菌、伤寒沙门氏菌、藤黄微球菌为供试菌，对刺松藻全藻甲醇／氯仿（1：1）提取物各组分进行了初步的抑菌活性测试，结果表明石油醚组分C3具有一定的抗菌活性。对组分C3进行进一步的分离，从中获得一个纯化合物Ⅰ，通过波谱手段鉴定其结构为植醇乙酸酯。     

刺松藻抑菌活性成分初步研究

以金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、铜绿假单胞菌、伤寒沙门氏菌、藤黄微球菌为供试菌,对刺松藻全藻甲醇/氯仿(1∶1)提取物各组分进行了初步的抑菌活性测试,结果表明石油醚组分C3具有一定的抗菌活性.对组分C3进行进一步的分离,从中获得一个纯化合物Ⅰ,通过波谱手段鉴定其结构为植醇乙酸酯.     

沙蚕活性物质的分离提取及对HeLa细胞的毒性分析

将采集于中国福建海岸的海洋环节动物沙蚕(Nereis virens)冷冻干燥后用不同极性的有机溶剂进行提取,提取物A2经硅胶柱梯度洗脱分离,发现石油醚/乙酸乙酯(体积分数1∶1)的洗脱组分B3有抗肿瘤活性.采用葡聚糖柱Sephadex LH-20对B3进一步等度洗脱分离,发现洗脱的组分C2有较高抗肿瘤活性.采用噻唑蓝(MTT)法测定组分C2对HeLa细胞的毒性,结果显示:该组分具显著的体外抗HeLa细胞活性,其IC50(48 h)达47.30μg·mL-1;AO/EB染色法观察细胞凋亡,结果显示药物处理48 h后细胞明显出现凋亡现象;流式细胞术探讨其抗癌机制,结果提示组分C2可能是通过诱导HeLa细胞发生G0/G1期和(或)S期阻滞而诱导细胞凋亡的.     

宣威火腿中抗菌肽的分离、纯化及鉴定

为探究干腌火腿中生物活性多肽的抗菌活性及其组成,选取产自中国云南省曲靖地区的宣威火腿为材料,通过缓冲液浸提的方法提取火腿中的多肽成分。以粗提多肽对单增李斯特菌和O157型大肠杆菌的生长抑制情况为指标进行抗菌性评价,同时结合离子交换色谱、尺寸排阻色谱等技术对宣威火腿粗多肽进行分离与纯化,并选取其中抑菌活性较强的组分进行氨基酸序列测定。抑菌实验发现宣威火腿粗多肽具有显著抑制单增李斯特菌和O157型大肠杆菌生长的效果；经过逐级分离纯化得到的各组分具有不同的抑菌活性。其中组分7活性最强,对大肠杆菌和李斯特菌的抑菌率分别为98%和56%。通过Nano-LC-ESI-MS/MS肽序列鉴定,最终得到抑菌活性较强的多肽序列,分别为QYYNGEEHVRFDSDVGEYR、LRNLPNLEVLDLGTNFI、FASFEAQGALANIAVDK。将鉴定得到的3条多肽化学合成后进行抑菌实验发现,合成多肽均具有较好的抑菌效果,对O157型大肠杆菌的生长抑制效果均显著高于单增李斯特菌。研究结果表明宣威火腿中含有抑菌效果的肽类成分,从而为阐释宣威火腿多肽的功能特征提供理论依据。     

FeCl3·6H2O催化合成2,3-二取代-1,3-苯并噁嗪及其杀菌活性

以2-(胺甲基)苯酚和取代苯甲醛为原料,首次以FeCl3·6H2O为催化剂合成了一系列2,3-二取代-1,3-苯并噁嗪,所合成化合物的结构用IR、1H NMR、13C NMR进行了分析与鉴定.采用离体法初步测试了目标化合物的杀菌活性,大部分化合物具有良好的杀菌活性,化合物3c对灰霉病菌的抑制率为86.8%,3f对纹枯病菌的抑制率为87.7%.     

刺松藻内生真菌长枝木霉的化学成分研究

对烟台近岸的绿藻刺松藻来源的一株内生真菌长枝木霉的次生代谢产物进行了探索.通过硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析、制备薄层层析和高效液相色谱等色谱分离手段,以及超导核磁共振等波谱鉴定技术,从该菌的马铃薯-葡萄糖和菊芋-葡萄糖液体培养基发酵产物中继续分离并鉴定了5个化合物,包括5α,8α-环氧麦角甾-6,22-二烯-3β-醇（1）;麦角-7,22-二烯-3β,5α,6β-三醇（2）;β-谷甾醇（3）;5-羟基-3-甲基戊-2-烯酸（4）和角鲨烯（5）.化合物4和5均为首次从木霉中分离得到.抑菌活性测试结果表明化合物1～5对细菌和真菌无明显抑制作用.     

2-酮基-L-古龙酸高产菌株的选育

实验采用离子注入技术对"二步发酵法"生产维生素C中的伴生菌-苏云金芽孢杆菌(Bacillusthuringiensis)进行处理,筛选维生素C的前体2 酮基 L 古龙酸的高产伴生菌菌株,以提高发酵生产水平。经过初筛、复筛,获得了使产酸活性提高的突变株,在筛选的646株菌中,有3株菌使收率提高了1-4%。     

山鸡椒提取物不同组分抑菌活性初步研究

以山鸡椒为植物材料,测定其乙醇提取物不同组分对几种植物病原菌的抑制活性。结果表明,在供试浓度为1mg／mL时,各个组分对几种植物病原真菌均有一定的抑制活性,尤其对番茄灰霉病菌和杨树溃疡病菌的抑制效果较为明显,特别是组分2对所有供试真菌的抑制效果最好,其中对苹果霉心病菌抑制率达到90％以上。有望从组分2分离得到抑菌活性强的有效成分。山鸡椒作为植物源杀菌剂值得进一步研究。     

山鸡椒提取物不同组分抑菌活性初步研究

以山鸡椒为植物材料,测定其乙醇提取物不同组分对几种植物病原菌的抑制活性。结果表明,在供试浓度为1 mg/mL时,各个组分对几种植物病原真菌均有一定的抑制活性,尤其对番茄灰霉病菌和杨树溃疡病菌的抑制效果较为明显,特别是组分2对所有供试真菌的抑制效果最好,其中对苹果霉心病菌抑制率达到90%以上。有望从组分2分离得到抑菌活性强的有效成分。山鸡椒作为植物源杀菌剂值得进一步研究。     

环已烷等C6环烷烃在铂/担体催化剂上的异构反应

本文以环已烷和甲基环戊烷在铂载在Al2O3 ,SiO2 ,Si-Al等不同担体的催化剂上进行的异构反应为探针 ,讨论催化剂的担体性质对C6 环烷烃异构反应的影响。结果表明 :对环已烷、甲基环戊烷的异构反应 ,担体对其异构反应的影响不大 ,主要是取决于催化剂的活性组分 ,因此对催化剂的调变主要应从活性组分的性质方面进行调变     

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