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1.
以肌动球蛋白的盐溶性、肌原纤维蛋白ATPase活性以及肌原纤维蛋白的疏基含量为指标,研究了鲫鱼(Carassius auratus)肌原纤维蛋白在-10℃,-20℃,-30℃和-40℃下冻藏时的变性情况。结果表明,在不同温度下冻藏时,鲫鱼肌动球蛋白的盐溶性、肌原纤维蛋白的ATPase活性以及巯基含量随着冻藏时间的延长,均呈下降趋势。且鲫鱼蛋白质的变性速度在不同冻藏温度下的差异是极其显著的(P<0.01),冻藏温度越低,变性越缓慢。  相似文献   

2.
对虾冷藏过程中肌肉蛋白特性的变化比较   总被引:4,自引:0,他引:4  
从生物化学、物理学两方面,比较养殖对虾和海捕对虾在冷冻贮藏过程中肌动球蛋白的特性变化,探讨不同贮藏温度和时间对蛋白特性的影响,及特性指标之间的相关性,冷藏后AM溶解度下降、ATPase活性下降,总SH和未遮盖SH数均减少,疏水性增大,而ATP感度呈下降趋势。所有指标变化表明随着冻藏时间的延长,蛋白质变性加剧,变性程度为-10℃〉-18℃〉-30℃,各项指标均显示养殖对虾蛋白质的耐冻性比海捕对虾弱。  相似文献   

3.
为探究使用环境中的温度变化对聚氯乙烯(polyvinylchloride, PVC)膜材料拉伸蠕变性能的影响,选取两种不同织物密度的PVC双轴向经编膜材料,在-40~40℃的交变温度环境中,分别进行200、300和400次循环处理,测试处理前后材料的拉伸与蠕变性能。结果表明:相同高低温交变处理次数下,密度低的PVC膜材料更易受到交变温度场的影响;材料的拉伸蠕变性能随交变处理次数的增加呈先上升后下降的趋势;200次交变温度处理对材料性能的影响较小,400次交变温度处理后材料的拉伸与蠕变性能明显下降;交变温度处理后PVC膜材料的拉伸蠕变性能的各向异性表现得更加明显。  相似文献   

4.
中国对虾肌动球蛋白变性后ATPase活性的研究   总被引:7,自引:1,他引:7  
在中国对虾肌动球蛋白经冷冻变性和热变性后,对Ca^2+-ATPase、Mg^2+-ATPase活性及蛋白质溶解度进行了研究。冷冻变性之后,肌动球蛋白Ca^2+-ATPase活性呈逐渐下降趋势,一般贮藏温度越低,活性降低超快。  相似文献   

5.
用疏水色谱(HIC)对8.0mol/L脲变性的α-淀粉酶(α-Amy)和α-糜蛋白酶(α-Chy)的变性动力学进行了研究。结果表明:α-Amy的变性为平缓的渐变过程,其变体数目较多,且绝大多数变体的疏水性都小于天然蛋白;α-Chy是骤变(可能是瞬间变性)过程,相对而言α-Chy的变体数目较少,且疏水性均大于天然蛋白。认为两种蛋白不同的脲变动力学行为,可能是因蛋白中α-螺旋含量以及蛋白质自身稳定性不同所致。  相似文献   

6.
小麦种子的真空冷冻干燥处理   总被引:1,自引:1,他引:1  
为了探索真空冷冻干燥技术用于小麦种子干燥处理的可能性,采用真空冷冻干燥、真空干燥和热风干燥3种方式对小麦种子进行干燥处理,在不同环境温度和压力下,研究种子中温度-时间分布曲线,并通过分析复水率、出芽率和幼苗生长情况进一步研究了这3种干燥方法对小麦种子生物活性的影响,研究结果表明,采用热风干燥时必须对干燥温度和干燥时间严格控制,否刚容易造成种子的死亡;真空干燥的方法易削弱小麦种子的生物活性,不宜用于种子的干燥处理;而经过真空冷冻干燥的种子的生物活性没有受到影响,真空冷冻干燥条件下小麦种子的平均存活率高于其它两种方式,可以应用于小麦种子的干燥。小麦在真空冷冻干燥下,水分冰晶升华温度与干燥室压力密切相关,在干燥室绝对压力为200-400Pa时,小麦中冰晶升华温度为18-20℃。  相似文献   

7.
猪血浆α_1-蛋白酶抑制剂的部分性质研究郑远旗,周昂,李建吾(生物系)在文[1]的基础上,我们对猪血浆α_1-PI部分理化性质进行了研究。1材料和方法1.1材料与试剂猪血浆为成都肉联厂屠宰猪血经抗凝后离心所得;Sepharose4B,Sephadex...  相似文献   

8.
温度和光照对心里美萝卜生殖生长期α-淀粉酶表达的影响   总被引:1,自引:1,他引:0  
为了研究温度和光照在生殖生长期,对心里美萝卜α-淀粉酶活性和同工酶谱带的影响,对萝卜进行了不同种植时间以及不同过冬方式的处理,并在生殖生长期的不同时间对萝卜肉质根和叶片中的α-淀粉酶活性进行了测定,同时采用非变性聚丙烯酰胺凝胶电泳方法对不同时期各个器官中的α-淀粉酶同工酶谱进行了分析.研究结果表明,低温和光照增加α-淀粉酶活性,α-淀粉酶同工酶谱带存在器官表达差异和时间表达差异,并与光照和温度有关.由此结论萝卜生殖生长期α-淀粉酶的表达受温度和光照影响.  相似文献   

9.
短切玻纤地强聚丙烯保持了丙烯的优点,性能已达工程塑料的水平。化学性质极为稳定,因住地进行二次加工-涂装。针对上述问题,该文采用化学氧化法对短切玻纤增强PP进行处理,邓用H2SO4-CrO3酸液,以不同的含量在不同的温度、时间条件下进行实验,寻找出处理的最佳配方。用表接解角θ及测定的粘结力表征处理效果,并采用先进的测试手段-电镜、二次离子质谱、电子能谱ESCA进行表面分析。  相似文献   

10.
研究变性淀粉颗粒的糊化温度随反应pH值、时间和三氯氧磷用量的变化规律,以及其DSC的糊化特性,结果发现酯化交联淀粉的糊化完成温度比原淀粉高,随反应pH值、时间和三氯氧磷用量的增加而升高,当反应pH值为8.0和9.0时,变性淀粉的糊化开始温度比原淀粉低,随反间时间、三氯氧磷用量的增加而降低;当反应pH值为10.0和11.0时,变性淀粉的糊化开始温度的变化则随反应时间、三氯氧磷用量的增加而升高,其值从比原淀粉低上升到比原淀粉高,这些变化规律同酯化交联淀粉的反应历程密切相关。  相似文献   

11.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

16.
17.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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