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.     

低温高湿解冻对南美白对虾保水性及肌原纤维蛋白生化特性的影响

以传统解冻——静水解冻、自然空气解冻及低温空气解冻为对照,通过考察解冻时间、保水性、pH值、色泽、质构、脂质氧化及肌原纤维蛋白生化特性变化,研究低温高湿条件(-1~1℃、2~4℃、5~7℃和8~10℃,相对湿度≥95%)对南美白对虾解冻效果及品质的影响。结果显示:静水解冻最快,仅需28.40min,低温空气解冻最慢,耗时367.33min。高湿有利于解冻,2~4℃时解冻速率较自然空气解冻、低温空气解冻提高了9.14%和57.62%。低温高湿(-1~7℃)解冻后,对虾保水性较高,2~4℃下解冻汁液流失最少,仅为传统解冻的16.32%~23.40%,离心失水率仅为2.80%;质构保持良好,2~4℃时质构最佳,硬度、咀嚼性显著高于传统解冻;脂质和蛋白质氧化明显改善,硫代巴比妥酸值显著低于传统解冻,总巯基含量明显提高,2~4℃解冻时表面疏水性甚至接近新鲜值,仅为7.69μg/mg(以每毫克蛋白质计);Ca²⁺-ATPase活性较传统解冻显著上升,蛋白质变性程度较低。综合解冻效率、品质及生产实际,低温高湿解冻是一种较为理想的解冻方式。     

加酶腌制对牛肉品质的影响

对比研究了腌制过程中,复合磷酸盐腌制、复合酶(木瓜蛋白酶与菠萝蛋白酶1∶1)处理、加酶腌制(腌制过程中添加复合酶)对牛肉品质的影响。通过测定色差、保水性、质构特性、游离氨基酸含量等指标。结果显示,腌制能显著提高牛肉的红度(P0.05),显著提高牛肉的保水性使其增重,并降低蒸煮损失;复合酶处理能显著提高牛肉的亮度(P0.05),极大改善牛肉的质构特性,使游离氨基酸含量增加;加酶腌制处理兼具二者优点,在显著改善牛肉质构特性的同时,还可使其获得较好的保水性、色泽,提高游离氨基酸的含量,必需氨基酸与风味相关氨基酸均升高。     

内脏水解蛋白对草鱼肉保水性的影响

本实验以草鱼为研究对象,采用碱法制备草鱼内脏水解蛋白液,并对草鱼肉进行保水,研究草鱼内脏蛋白水解液对草鱼鱼肉保水性的影响.以浸泡增重率、解冻损失率、蒸煮损失率为参考指标选择最佳保水条件.通过分析草鱼鱼肉冻藏后的质构性质、水分存在状态、色泽变化,研究草鱼内脏蛋白水解液对草鱼鱼肉保水性的作用.研究结果如下:草鱼内脏水解蛋白液制备的最佳pH为11,用5%蛋白液-0. 15%复合磷酸盐的保水剂在10℃条件下浸泡草鱼肉60 min,与复合磷酸盐处理组对比,冻藏后解冻损失率低31. 43%,准结合水增加9. 38%.     

不同解冻方式对冷冻豆沙包面团特性及产品品质的影响

为了研究不同解冻方式对冷冻豆沙包面团特性以及食用品质的影响,采用4℃冷藏解冻、超声辅助解冻、恒温恒湿解冻、气浴震荡解冻和微波解冻5种方式对冷冻豆沙包面团水分迁移、热力学以及流变学特性进行研究,并对由此面团制作豆沙包的水分流动性、质构、色泽以及蒸煮品质进行分析。结果表明,5种解冻方式豆沙包生坯面团的A₂₁、A₂₂,弹性模量G′和黏性模量G″,可冻结水含量均存在显著差异(P＜0.05)。从水分分布分析,4℃冷藏解冻的生坯面团强结合水的变化最小；经动态流变学分析,微波解冻的面团具有最高的黏弹值；通过差示扫描量热分析可知,气浴震荡解冻的面团可冻结水含量最高。除此之外,不同解冻方式处理的豆沙包加热后其水分、质构、色泽和蒸煮特性也存在显著差异(P＜0.05)。水分流动性显示,超声辅助组A₂₁含量最少；质构特性表明,4℃冷藏解冻组硬度最低、咀嚼性最优；恒温恒湿解冻组呈现最稳定的色泽和蒸煮品质；比容最小的是微波解冻组。本研究表明,4℃冷藏解冻减少了冷冻豆沙包面团水分的流失且能较好地保持蒸制后豆沙包产品的综合品质,恒温恒湿解冻有效地降低了豆沙包产品的蒸煮损失且与4℃冷藏解冻相比缩短了解冻时间,其他几种解冻方式在冷冻豆沙包面团的应用中仍需要进一步的研究。     

制干温度对“果汁杏干”品质的影响

针对不同干制温度导致杏干果实发生褐变、水分含量不同、质地和感官品质降低等问题,探究不同制干温度对"果汁杏干"品质的影响,以期得出杏干最佳制干温度.以鲜杏为材料,通过设置不同温度(40℃,45℃,50℃,55℃,60℃)对杏进行低温烘烤,研究在不同制干温度下,杏干水分含量、生理指标及感官品质的变化.结果表明,处理温度在55℃时,通过维持杏干的水分含量在16%左右,可以较好地抑制杏干在干制期间总色差的升高,减缓总酸含量、抗坏血酸(Vc)含量、还原糖含量的下降,并且可以较好地维持杏干的营养品质和感官品质.     

兔深低温停循环体外循环模型的建立

目的建立新西兰兔深低温停循环(deep hypothermic circulatory arrest,DHCA)体外循环(cardiopulmonary bypass,CPB)模型。方法健康新西兰兔10只,雌雄不限,体重(2.5±0.5)kg。动脉套管针穿刺连接主动脉灌注管,右心耳切开连接静脉引流管建立体外循环。肛温降至20℃时停循环,维持兔直肠温度16℃~20℃,持续60 min后,恢复循环并复温至36℃时脱离体外循环。监测心电图、血液动力学变化。结果9只成功建立深低温停循环体外循环模型,1只死于模型建立过程中出血。预充溶液75 mL,平均转流时间140 min,CPB过程中平均动脉压在正常范围内,9只兔主动脉开放后心脏成功复跳。结论新西兰兔深低温停循环体外循环模型稳定、可行,成功率较高,是进行低温停循环体外循环基础研究、脑保护作用及其机制研究的理想模型。     

碳酸钠在嫩化型风干牛肉中的应用效果研究

为了探究碳酸钠注射对风干牛肉嫩化效果及品质的影响,实验分别测定了不同浓度碳酸钠(0、0.25、0.30、0.35、0.40mol/L)注射处理风干牛肉的pH值、剪切力、水分含量、水分活度、出品率和感官品质。结果表明,随着碳酸钠浓度的升高,风干牛肉的pH值、水分含量、水分活度和出品率显著增加(p<0.05),剪切力下降,嫩度增加;但是,当碳酸钠浓度超过0.35mol/L,风干牛肉的感观品质会明显变差,咀嚼性降低,且有一定程度的碱味。结合相关性分析可得,pH值与风干牛肉的嫩度、水分含量、水分活度、出品率等呈现极显著的正相关关系(P<0.01),说明碳酸钠注射对牛肉嫩度的影响主要与肉中pH值变化有关。实验证明,碳酸钠注射处理可以有效改善风干牛肉食用品质,浓度为0.35mol/L时,效果最好,在此条件下,风干牛肉的剪切力可降低33.67%,出品率提高12.05%,为45.12%;pH值的改变是碳酸钠注射对牛肉嫩度及品质改善的主要原因。     

促进剂M精制新工艺研究

研究了原料配比、反应温度和时间等对产品质量和收率的影响,通过L(4’)正交实验确定出的最佳合成配方及工艺条件:原料配比n(M)∶n(分离剂)=1∶0.55;n(M)∶n(转化剂)=1∶0.5;分离反应温度:50~60℃;分离反应时间:30min;转化反应温度:30~40℃;转化反应时间:120min;置换反应温度:40~50℃;置换反应时间:60min;置换液浓度:10%;置换反应终点pH:9.0~10.0。稳定运行结果表明,产品熔点≥172.7℃,收率达到92.5%以上。     

黔产紫陀螺菌深层发酵条件的优化及成分分析

采用摇瓶培养法对紫陀螺菌(Gomphus purpuraceus)适宜的发酵碳源和氮源、发酵条件进行了分析研究,结果表明:最适宜的碳源、氮源分别是葡萄糖和牛肉膏;最优发酵条件的初始pH5.4~6.2,振荡速度145r/min,培养温度26℃,100mL三角瓶装液量50mL。此外,还测定了紫陀螺菌深层培养菌丝体中蛋白质成分中的氨基酸种类。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

An Index mechanism for multi-scale view in spatial databases

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.     

A computer generator for randomly layered structures

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

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

Exciton Seebeck in Molecular Systems

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     

Achieving Unusual States of Matter Under High Pressure

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.