蜂房芽孢杆菌木聚糖酶的活性

实验研究了温度、pH值和Al^3 、Zn^2 、K^ 、Ca^2 、Mg^2 、Mn^2 、Fe^3 及Cu^2 等几种常见金属离子对蜂房芽孢杆菌木聚糖酶活性的影响，结果表明该酶最适温度为40℃，最适pH为6．0，在低温及pH7．0—9．0条件下，该酶活性稳定；Ca^2 、Mg^2 、Mn^2 对木聚糖酶有激活作用，Cu^2 、Al^3 、Zn^2 和Fe^3 对木聚糖酶有抑制作用，Cu^2 的抑制作用最强。     

孢薪菇漆酶的提取及其理化性质

从孢薪菇（Coprinus coimtav）、金针菇（Flammulina velutipes）、平菇（Pleurotus sapidus）、茶薪菇（Agrocybe cylindracea）、黑木耳（Hirneola auricular-judae）和香菇（Lentinula edodes）子实体中提取漆酶，用分光光度法测定酶活，筛选出漆酶酶活最高的孢薪菇。实验结果表明，孢薪菇漆酶是一种对热较稳定的高温酶，其最适pH3.0，最适温度60℃；Pb^2 、K^ 对酶活有较大的激活作用，而Fe^3 、Fe^2 则对酶活有较强的抑制作用。     

产β—1，3—葡聚糖酶链霉菌菌株的筛选及其酶特性研究

从大白菜植株根际土壤中取样，通过茯苓粉琼脂培养基的透明圈试验，分离筛选到4株产β—1，3—葡聚糖酶的链霉菌菌株R8，R15，R31和AS。经比较发现，链霉菌菌株R15最早产生较明显的透明圈，且透明圈最大，澄清度最高，从R15菌株提取酶液，测定其分解β—1，3—葡聚糖的酶活力。结果表明，该酶作用的最适温度为55℃，最适pH为5．0；低于55℃，pH7．5以下，该酶较稳定；Fe^3 ，K^ ,Cu^2 ，Hg^2 对酶有抑制作用，而Ca^2 ,Fe^2 ，Ba^2 ，Mn^2 ，Al^3 及Zn^2 对酶有激活作用，抑菌圈试验表明，该酶对小麦纹枯病菌具有很强的抑制作用，抑菌圈宽度达15mm。盆栽防病试验结果表明，小麦种子经酶液处理后，病根率为34．51％，防病效果为64．28％。     

白毒鹅膏菌胞外漆酶的部分酶学性质研究

从威海市玛珈山上获得白毒鹅膏菌,在对其产酶条件研究的基础上,研究了pH值、温度、无机离子对白毒鹅膏菌漆酶活性和稳定性的影响,测定了漆酶的Km值。结果表明：Ba^2＋、Cu^2＋、、SO4^2-离子对漆酶有激活作用,而Ag^2＋、Cl^-、Fe^3＋离子则有抑制作用,该酶最适pH为4.6,在pH 5.0-5.4表现出较强的稳定性;最适反应温度为20℃,低于60℃时有较好的热稳定性;以邻联甲苯胺为底物的表观Km值为66.7μmol/L。     

高纯度烟草过氧化物酶的酶学特性研究

从K326的烟叶中采用除植物褐色素新技术，经分离纯化，得到单一过氧化物酶I（TOP I），该酶是一种以血红素为辅基的含铁蛋白质。基质辅助激光解吸电离飞行时间质谱（MALDITOF－MS）测得TOP I分子量为21888．5Da，等电点pI为3．5；酶反应的最适pH为6．0，最适温度为45℃，70℃保温15min残余活力为50％，具有良好的热稳定性，动力学分析表明：烟草中的过氧化物酶I与愈创木酚（一元酚）结合力最强，邻苯二酚（二元酚）次之，焦性没食子酸（三元酚）作用较小。TOP I和Km(愈创木酚）为0．132mmol/L;Km(H2O2)为0．598mmol/L.N3^-,CN^-1,Fe^3 ,Fe^2 和Sn^2对酶有较强烈的抑制作用，重金属离子Ag^ ,Pb^2 ,Cu^2 对该酶的活性有激活作用，而NO2^-、Hg^2 ,Cr^3 对酶活力无显著影响。     

糙皮侧耳Ax3产漆酶条件及部分酶学性质研究

对糙皮侧耳(Pleurotus ostreatus)Ax3菌的漆酶产生条件进行了研究，该菌产漆酶较高的条件是：培养温度25℃，培养基pH5．5，每升C／N含量0．252g／0．021g；加入0．05％～0．1％的吐温可提高漆酶酶活12倍。对漆酶的部分生化性质研究表明：最适反应温度25℃；最适反应pH2．8；琥珀酸缓冲液效果最好；金属离子：Mn^2 ，Cu^2 ，Zn^2 对漆酶有较强的激活作用，其中Mn^2 相对活性最高，Ag^ ，K^ ，Ca^2 ，Fe^2 对漆酶活性有抑制能力，其中Ag^ 的抑制作用明显。     

康氏木霉木聚糖酶的分离纯化及特性

使用硫酸铵分级沉淀、Sephadex G-25凝胶色谱脱盐和Sephadex G-100凝胶色谱等分离纯化技术，从康氏木霉（Trichoderma Koningii）发酵液中分离出木聚糖酶，纯化后的木聚糖酶经十二烷基硫酸钠一聚丙烯酰胺（SDS-PAGE）凝胶电泳鉴定为单一组分，其相对分子质量为55208．所得的木聚糖酶的最适反应温度为65℃，pH值为6．0．该酶稳定性较好，在30—60℃下放置2h能保持83％以上的酶活；在3．0-10．0的pH值范围内能保持85％以上的酶活．研究表明：金属离子Ba^2＋，Pb^2＋，Fe^2＋，Fe^2＋，Al^3＋和高浓度（12mmol/L）的Cu^2＋对木聚糖酶的活性有抑制作用，而Ca^2＋，Zn^2＋和4mmol／L的Cu^2＋对该酶反应有促进作用．该木聚糖酶作用于Birchwood木聚糖的米氏常数为5．37g/L，最大反应速率为0．94μmol／min．     

固定化α_葡萄糖苷酶的性质研究

研究了以微球形壳聚糖为载体采用吸附－交联法制备的固定化α-葡萄糖苷酶（简称“ITGL”）的理化特性。结果表明,ITGL的最适pH值为4．5,游离酶（简称“TGL”）的最适pH值为5．0;ITGL的最适温度达到70℃,比TGL的提高5℃,并且ITGL的最适作用温度范围显著变宽,在40－70℃范围内活力较为稳定;ITGL的酸碱稳定性、热稳定性和贮存稳定性均比TGL有较大提高;TGL和ITGL均对高离子强度和脲不稳定;低浓度的Ca^2 和Mg^2 对TGL和ITGL的活力均有增强作用,而Fe^2 、Ag^2 、Cu^2 、Hg^2 对TGL和ITGL的活力均有明显的抑制作用;ITGL的操作半衰期可达24d;以麦芽糖为底物时,ITGL的反应动力学参数无显著变化。     

修饰性载体固定化漆酶

采用壳聚糖铜固定化和交联酶聚集体的方法固定化漆酶.探索了固定化前后漆酶的最适温度、pH,热稳定性和金属离子对其活性的影响,交联漆酶聚集体制备的条件.结果为:游离漆酶的最适温度是20℃,最适pH是4.6;壳聚糖铜固定化漆酶的最适温度是25℃,最适pH是4.0;交联漆酶聚集体的最适温度是15℃,最适pH是3.6.固定化后漆酶的热稳定性提高,不同金属离子影响固定化漆酶的活性,其中K+的激活作用尤为明显.制备交联漆酶聚集体最适戊二醛浓度为1%,最适交联时间是2 h.     

纤维素酶固定化研究

利用固态发酵法从瑞氏木霉QM9414发酵液中提取纤维素粗酶液,然后将其固定在壳聚糖上,测定粗酶液的酶活力,固定化酶与粗酶的最适pH,最适温度和Km值.结果表明,粗酶液的蛋白质含量为33.33 ug/mL,酶活力为120 IU/mL.固定化酶的最适温度为60℃而粗酶液为50℃,粗酶液的最适pH=5,固定化酶的最适pH=4,固定化酶的Km值3.592 01×10-2,粗酶液的Km值为4.076 04×10-2,表明固定化酶的很多性质均优于游离酶液.     

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