活性微生物、pH值、温度对淡水白鲳主要消化酶活性影响的研究

经测定,淡水白鲳淀粉酶、蛋白酶的适宜温度分别为250 ℃和450 ℃;最适pH值分别为6.4和2.6.在最适温度、pH值条件下,不同组织淀粉酶活力大小顺序为肝胰脏>肠>胃,蛋白酶活力大小顺序为胃＞肠＞肝胰脏.分别用酵母菌、光合细菌作饲料添加剂拌喂淡水白鲳,结果表明酵母菌、光合细菌对生长均有明显的促进作用,能显著提高胃、肠淀粉酶和蛋白酶的活性,及提高肝胰脏淀粉酶的活性,但在一定程度上降低了肝胰脏蛋白酶的活性.     

pH和温度对黄姑鱼主要消化酶活力的影响

采用酶学分析的方法,研究了在不同pH和温度下离体黄姑鱼蛋白酶、淀粉酶、脂肪酶的活性变化。结果表明:pH和温度对黄姑鱼主要消化道各部位消化酶活力多数有显著影响(P0.05),在黄姑鱼前肠、中肠、后肠、胃、肝胰脏5个部位,蛋白酶的最适pH分别为6.4、7.8、7.8、2.2、6.4,淀粉酶最适pH分别为5.0、7.8、7.8、6.4、5.0,脂肪酶的最适pH分别为5.0、6.4、7.8、3.6、5.0;在最适pH条件下,前肠、中肠、后肠、胃、肝胰脏中蛋白酶的最适温度均为40℃左右,淀粉酶的最适温度除肝胰脏中为40℃外,其他部位均为30℃,脂肪酶的最适温度均为40℃。蛋白酶活力在pH 6.4、37℃时达到最大值1 606.576±83.457 U,淀粉酶活性在pH 6.4、37℃时达到最大值188.086±17.538 U,脂肪酶在pH 5.0、40℃时达到最大值34.247±1.926 U。     

温度和pH对驼背鲈消化酶活力的影响

采用酶学分析方法研究了温度和pH对驼背鲈3种主要消化酶(蛋白酶、脂肪酶、淀粉酶)活力的影响。结果表明:在设定的温度和pH范围内,驼背鲈消化酶活力均随着温度和pH的升高呈先升后降的趋势。其中,胃蛋白酶的最适温度为40~45℃,肠、幽门盲囊、肝蛋白酶的最适温度均为40℃;胃脂肪酶的最适温度为35℃,幽门盲囊的最适温度为40~45℃,其他部位均为40℃;胃淀粉酶的最适温度为40℃,其他部位均为35℃。胃蛋白酶的最适pH为3.2,肠、幽门盲囊、肝的最适pH均为8.2;胃、肝脂肪酶的最适pH分别为7.2、8.2,其他部位均为6.2;胃淀粉酶的最适pH为7.2~8.2,其他器官的最适pH均为7.2。各部位在最适温度和pH下,脂肪酶酶活力顺序为肠胃肝幽门盲囊,淀粉酶酶活力顺序为肠幽门盲囊胃肝;蛋白酶在最适温度和pH下的酶活力顺序分别为肠胃肝幽门盲囊、肠胃幽门盲囊肝。     

不同PH条件下乌鳢胃,肠,肝胰脏蛋白酶活性的初步研究

以乌鳢（OPhiocephalusargus）为研究材料,获得在不同pH条件下胃、肠、肝胰脏蛋白酶的活性变化及酶的最适pH值（分别为3．0、8．0和8．4）．三者在最适pH值时酶活性的大小顺序为胃＞肠＞肝胰脏．pH对胃蛋白酶的影响大于对杨道蛋白酶和肝胰脏蛋白酶的影响．     

兰州鲇消化器官理化特征及pH值对其消化酶活力的影响

对兰州鲇(Silurus lanzhouensisChen)消化器官的理化特征及在不同pH条件下的消化酶活力进行了研究.结果表明,兰州鲇比肠长、比胃重、比肠重、比肝胰脏重、比内脏重分别为0.91±0.25、0.0158±0.0045、0.0112±0.0054、0.0199±0.0069和0.0916±0.0293;胃、前肠、中肠、后肠壁及胆汁的pH值分别为5.5~6.5、5.5~7.0、6.0~7.0、6.0~7.0和5.5~7.0;胃、肝胰脏和肠淀粉酶最适pH值分别为5.4、6.6和7.0,脂肪酶最适pH值分别为5.4(或5.8)、6.6和6.6.兰州鲇胃和肠的pH值环境均有利于淀粉酶和脂肪酶活力的发挥.在最适pH条件下,肝胰脏淀粉酶活力略高于肠,胃淀粉酶活力最低,而肝胰脏和肠的脂肪酶活力相同,胃脂肪酶活力最高.从消化器官特点和消化道内食物组成可以看出,兰州鲇消化生理特性与其肉食性特点相适应.     

反应温度对中国龙虾消化酶活力的影响

采用酶学分析方法研究了反应温度对中国龙虾胃蛋白酶、类胰蛋白酶、淀粉酶、纤维素酶和脂肪酶活力的影响.结果表明,在设定的反应温度范围内,中国龙虾各消化酶的活力均随反应温度的升高呈现先上升后降低的变化趋势.其中,胃、肠、肝胰腺内,胃蛋白酶最适反应温度分别为31、39、31～47 ℃;类胰蛋白酶最适反应温度均为39 ℃;淀粉酶和纤维素酶最适反应温度均为23 ℃;脂肪酶最适反应温度分别为23、31、31 ℃.中国龙虾的消化酶活力存在器官特异性.在最适反应温度下,中国龙虾不同消化器官内各消化酶的活力顺序为胃蛋白酶:胃肠肝胰腺,类胰蛋白酶、脂肪酶:肝胰腺肠胃,纤维素酶:肝胰腺≈肠>胃,淀粉酶:肠肝胰腺胃;中国龙虾各消化酶在同一消化器官内的活力顺序为胃内:纤维素酶≈胃蛋白酶类胰蛋白酶≈淀粉酶脂肪酶,肠内:纤维素酶类胰蛋白酶≈淀粉酶≈胃蛋白酶脂肪酶,肝胰腺内:纤维素酶类胰蛋白酶淀粉酶≈胃蛋白酶≈脂肪酶.     

不同温度和pH值对瘤背石磺(Onchidium verruculatum Cuvier)消化酶活性的影响

研究了温度和pH值对瘤背石磺(Onchidium verruculatum Cuvier)肠淀粉酶、肝胰腺淀粉酶和胃淀粉酶以及相应的纤维素酶活性的影响.不同温度和pH值对瘤背石磺消化酶活性的影响显著(P<0.05).当温度在5-75℃时,肠淀粉酶和纤维素酶分别在35℃和30℃时活性较高;肝胰腺淀粉酶和纤维素酶分别在35-45℃和50℃时活性较高;胃淀粉酶活性在25-45℃维持较高水平,随后随温度的升高而下降,纤维素酶活性在50℃时较高.在pH为3.0-8.0范围内,肠淀粉酶和纤维素酶的最适pH值均为6.0;肝胰腺淀粉酶和纤维素酶的最适pH值分别为6.9和5.4;胃淀粉酶和纤维素酶的最适pH值分别为6.5和6.0.在适宜温度和pH条件下,肠淀粉酶、肝胰腺淀粉酶和胃淀粉酶活性均远大于肠纤维素酶、肝胰腺纤维素酶和胃纤维素酶.     

斜带石斑鱼消化器官的蛋白酶和淀粉酶活力变化

在广东阳江闸坡网箱养殖区,采集不同生长阶段的斜带石斑鱼样品,体重20～500 g。采用酶学分析方法研究了斜带石斑鱼胃,幽门盲囊、肠、肝胰脏蛋白酶和淀粉酶的活力。结果表明,30℃养殖水温下,各部分蛋白酶活力为幽门盲囊>胃>肠>肝胰脏,淀粉酶活力为肝胰脏>幽门盲囊>肠>胃。在斜带石斑鱼发育进程中,300 g前蛋白酶活力呈上升趋势,350 g前淀粉酶活力呈上升趋势。胃、幽门盲囊、肠、肝胰脏蛋白酶活力的最适温度和pH依次为40℃和3.0,40℃和8.0,50℃和8.0,50℃和7.0,胃、幽门盲囊、肠、肝胰脏淀粉酶活力的最适温度和pH依次为40℃和5.0,40℃和8.0,50℃和8.0,50℃和7.0。     

pH对真鲷蛋白酶和淀粉酶活力的影响

应用酶学分析研究不同pH度条件下真鲷成鱼胃、肠、肝胰脏和幽门盲囊4个部位蛋白酶和淀粉酶活力的变化.结果表明,真鲷成鱼胃、肠、肝胰脏和幽门盲囊蛋白酶的最适pH分别为6.4,7.2,7.6和8.4,淀粉酶的最适pH分别为6.4,8.0,8.0和7.6.     

暗纹东方鲀蛋白酶活性的研究

pH是影响蛋白酶活性的显著因素之一 .本文仅初步探讨了pH对一龄、二龄两种规格暗纹东方的胃、肠、肝胰脏蛋白酶活性的影响 .结果表明 ,一、二龄鱼的胃蛋白酶最适pH均在 2 .2 ,肠蛋白酶最适pH为 8.5 ,而一龄鱼肝胰脏蛋白酶最适pH在 9.0以上 ,二龄鱼的最适pH为 8.5 .另外 ,蛋白酶活性大小依序为胃、肠、肝胰脏 .0 .5mol/LCaCl2 溶液能明显的抑制胃蛋白酶的活性 .     

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.     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with