真空冷冻干燥香蕉片的工艺研究

采用电阻法测定香蕉片冻干过程的共晶点和共熔点温度,研究不同物料成熟度、厚度、护色剂、冻结方法、加热板温度、干燥室真空度对香蕉冻干品得率、复水率、维生素C含量、可溶糖含量、酸度等的影响,结果表明:香蕉物料选用成熟度在7～8分熟,切成5～7mm厚度,选用L-半胱氨酸(L-Cys)护色,采用速冻方法冻结,干燥室真空度控制于70Pa,加热板温度0-60min～240min～300min～360min走势设定为20℃～60℃～60℃～40℃～40℃,所获香蕉冻干片品质优、产量高.     

1-甲基环丙烯对高温贮藏的香蕉果实抗氧化酶活性的影响

香蕉果实用0.5μL稬-11-甲基环丙烯(1-MCP)处理24 h后,在35℃高温下贮藏,研究1-MCP对香蕉果实丙二醛(MDA)、脯氨酸含量和保护酶系统的影响.结果表明,35℃高温下,香蕉出现明显的"青皮熟"现象,果皮中MDA含量迅速增加.1-MCP处理不同程度地提高了香蕉果皮过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,抑制了果实膜脂过氧化,延缓了MDA含量的上升,增加了脯氨酸的累积,减轻了香蕉热害.1-McP处理果实于35℃下贮藏9 d后移入20℃环境,进一步增加了POD和SO的活性.     

红枣冻干解析工艺优化研究

本文采用电阻法测量了红枣的共晶点、共熔点温度,其值为-32℃和-28℃。进行了单因素和正交实验,分别研究了冻结温度、枣片厚度、真空压力、冷阱温度及加热板温度对解析时间和能耗的影响,确定了解析工艺最优参数：加热板温度45℃、真空压力30Pa、冻结温度-38℃、冷阱温度-50℃。     

9个二元有机物系统相图和它们共晶点的理论计算

利用改进的准正规模型,根据热力学理论获得了决定二元液-固相平衡的曲线方程.对9个具有低共晶点的二元有机物系统,计算了它们的相图和低共晶点(T0,xB0)的数值,结果与实验数据符合的很好.     

宁夏宁杞1号花期霜冻过冷却实验研究

以宁夏枸杞主栽品种宁杞1号为研究对象,通过人工霜冻模拟箱进行过冷却实验,分花蕾期、初花期、盛花期等不同阶段分析其过冷却点和结冰点温度,并统计不同低温范围的分布比例,计算分析达到过冷却点所需的时间.结果表明,花蕾期、初花期、盛花期的过冷却点分别为-9～-3.8℃,-8.8～-4.0℃,-8.5～-3.4℃,结冰点分别为-6.9～-3.1℃,-5.7～-2.9℃,-5.4～-2.5℃,花蕾期比初花和盛花期的过冷却点分别平均低0.2,0.7℃,结冰点分别低0.5,1.3℃.花蕾期、初花期、盛花期的过冷却点频率分布不同,但分布趋势均呈单峰曲线状,趋势峰值分别出现在-8～-7℃,-7～-6℃,-6～-5℃.各花期达到过冷却点的平均时间分别为5.1,4.6,4.5 h.花蕾期、初花期、盛花期的结冰点和过冷却点呈逐渐升高的趋势,初花和盛花期的"跃升值"接近,均大于花蕾期;随着发育进程的推进,达到过冷却点的时间呈逐渐减小的趋势,且花器官的抗冻性逐渐减弱.     

沙棘果总黄酮提取工艺及抗氧化性研究

以沙棘果为原料,乙醇溶液为主要溶剂,沙棘果总黄酮提取量为评价指标,采用超声波辅助法在单因素实验基础上结合响应面分析法,综合考察了超声提取时间、提取温度、提取液(乙醇)体积分数、液料比4因素对沙棘果总黄酮的提取量影响.结果表明,沙棘果中总黄酮的最佳提取条件为：超声提取时间34 min、提取温度77℃、提取液(乙醇)体积分数60%、料液比22.8∶1.在此工艺条件下沙棘果总黄酮得率为5.694 mg/g,与理论预测值5.770 mg/g的RSD值为1.33%,小于5%,模型拟合性良好.对制得的沙棘果总黄酮提取物粗品,采用清除DPPH自由基法与羟自由基法,以同浓度的维生素C溶液作为阳性对照,进行体外抗氧化活性测定.按清除DPPH自由基法得到的维生素C、沙棘果提取物的IC₅₀值分别为0.13、2.32 mg/mL,按羟自由基法得到的IC₅₀值分别为0.11、0.45 mg/mL,说明沙棘果总黄酮具有较好抗氧化活性.     

吡嗪酰胺-2,5-二羟基苯甲酸共晶制备及过程在线研究

吡嗪酰胺(PZA)为最有效的抗结核药物之一,其水溶性差,通过形成共晶的方法可以改善其溶解度,提高药效.本文通过悬浮法制备了PZA和2,5-二羟基苯甲酸(2,5-DHBA)共晶,产品采用X-射线粉末衍射(PXRD)、差式扫描热分析(DSC)、傅里叶变换红外(FT-IR)和拉曼光谱(Raman)进行表征.结果表明,利用悬浮法可以制备出纯度较高的PZA-2,5-DHBA(1∶1)共晶.进一步采用衰减全反射傅里叶变换红外光谱仪(ATR-FTIR)和在线拉曼光谱等过程分析技术(PAT),监测并分析了该共晶的形成过程.结果表明,在30,℃下PZA-2,5-DHBA(1∶1)共晶在乙腈中的溶度积为9.4×10-4(mol/L)2;且该过程为PZA溶解-共晶生成的两步过程,存在成核介稳现象,过程控制步骤为共晶生长.     

赝三元系KBe2F5-KAlF4-K3AlF6的相图

采用溶液反应法制样,用目测变温和DTA方法测定了AlF,-BeF2-KF三元系中的KBe2F5KAlF4-K3AlF6赝三元系的相图.体系中有一个三元低共晶点E,组成为4 mol%KF、15 mol%KAlF4和81 mol%KBe2F5,温度为310℃.在KBe2F5的含量低于70 mol%时,沿着e1o→E共晶线组成的熔盐是可以利用的中温铝钎剂.(e1是KF-AlF3体系中K3AlF6与KAlF4之间的共晶点).     

二维Collins模型与具有低共晶点的二元系相图

本文把二维单元系统的Collins模型推广到二维二元替换式系统,获得了与三维二元合金的情形十分相似的、具有低共晶点的二元系相图.计算结果还表明,低共晶点的温度随4-原子所占百分数的增加而下降.     

Fe-Zr-B相图热力学计算及非晶合金的制备

用相图热力学计算技术对Fe-Zr-B三元系进行相图热力学计算,获得Fe-Zr-B共晶点成分,并利用机械合金化法制备Fe60Zr40-xBx(x=10,20,30)非晶合金粉末.在理论共晶点附近的Fe60Zr20B20和Fe60Zr10B30体系的非晶形成能力要高于较远的Fe60Zr30B10体系,说明组成愈接近理论共晶点,其非晶形成能力愈强,证明共晶点预测非晶形成范围是可行的.     

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.