基于云存储的数据备份研究

信息时代,各种数据呈爆炸式增长,数据在人们的日常生活和工作中所扮演的角色越来越重要。然而,黑客活动日益猖獗,病毒泛滥,系统漏洞百出等因素,使得数据面临着极大的威胁,数据安全问题备受人们关注。作为一种安全策略,数据备份在保证数据完整性和可用性的同时,有效地避免了数据丢失引起的损失。阐述了数据备份的3种常用策略,对基于云存储的数据备份进行了深入研究

Purification and Properties of β-glucosidase from Aspergillus glaucus EU7-22

目的:利用灰绿曲霉Eu7-22发酵产纤维素酶,从中分离到β-葡萄糖苷酶,分析其理化特性,确定其最佳活性条件。方法:灰绿曲霉Eu7-22发酵液离心后,上清液经硫酸铵沉淀、PHEnyl 6 fAST flOW(HIgHSub)疏水层析和SEPHACryl S-200凝胶层析,获得纯化的β-葡萄糖苷酶。结果:纯酶的比活性为5.1 Iu/Mg,得率为13.89%。SdS-PAgE凝胶电泳分析表明该酶是单亚基蛋白,其分子量为56.2 kdA。在PH4.0--6.0范围内,β-葡萄糖苷酶具有较高的稳定性,该酶的最适酶促反应PH为5.0。当β-葡萄糖苷酶在温度低于60℃的缓冲液中温育1 H后,酶活损失不大,表现了较好的稳定性;当该酶在温度高于60℃的缓冲液中温育1 H后,酶活迅速丧失。β-葡萄糖苷酶在70℃时具有最大催化活性。结论:灰绿曲霉Eu7-22发酵产生的β-葡萄糖苷酶具有较高活性,具有分子量较小、最佳催化温度较高的特点。Objective:β-glucosidase produced by Aspergillus glaucus EU7-22 was purified and characterized.Method:The β-glucosidase of Aspergillus glaucus EU722 was purified from ferment supernatant liquid by three steps of purification,ammonium sulfate precipitation(80%,W/V),Phenyl 6 Fast Flow(high sub) column chromatography and Sephacryl S-200 column chromatography,with a specific activity of 5.1 IU/mg and a yield of 13.89%.Result:The purified β-glucosidase was determined as a monomeric protein with a molecular weight of 56.2 kDa.The enzyme exhibited high stability when it was kept in the buffer at pH 4.0～6.0 and at the temperature below 60℃.β-glucosidase exhibited its optimal activity at 70℃.Conclusion: β-glucosidase produced by Aspergillus glaucus EU7-22 with small molecular showed high activity under the optimal conditions.国家“973”计划项目(2010CB732201);国际科技合作重点项目(2009DFA60930)资

Innovation and Practice on the Construction of Marine Biological and Ecological Field Practice Base in the Yangtze Estuary and Adjacent Sea

文章以国家自然科学基金委首个海洋科学类野外实践基地——长江口及邻近海域海洋生物与生态野外实践基地的建设为背景,从充分利用区位优势、突出综合实践功能、有效整合校际资源、积极筹措建设经费、创新基地管理体制、加强基地开放共享、促进科教有效融合、提升平台建设水平等八个方面进行了创新与实践,并对建设过程中的体会与问题进行了探讨。Based on the background of the construction of marine biological and ecological field practice base in the Yangtze estuary and adjacent sea which is the first field practice base of marine science supported by the National Natural Science Foundation of China,we try to make some innovation and practice from the following eight aspects： taking full advantage of location,highlighting the comprehensive practical function,integrating universities＇ resources effectively,raising funds for construction actively,innovating management system of field,strengthening open sharing of bases,promoting effective integration of science and education,and improving the level of platform construction. At last,this paper discusses the experience and problems in the construction process.国家自然科学基金野外实践能力提高项目（项目编号：J1310037）; 浙江省高等教育教学改革项目（项目编号：jg2015090

T型磁流变制动器的有效工作间隙位置对制动性能的影响

针对T型结构磁流变制动器工作间隙的位置和数量的不同对制动性能的影响，结合理论建模与模拟仿真分析，在同等外形尺寸、同种磁流变液材料的约束下，对T型结构磁流变制动器不同工作状态下的制动力矩和磁场分布进行了研究。基于工作间隙的不同位置和数量，进行了磁路的设计和制动力矩理论建模与计算；通过仿真结果和理论计算结果的对比，对不同位置的工作间隙所产生的制动力矩进行了分析。结果表明，当所使用磁流变液的材料、制动器的外形尺寸一致的情况下，对比制动力矩的仿真分析结果和理论计算结果，两者的相对差值在盘式工作状态下大于筒式工作状态。其中，盘式工作状态下，间隙A的相对差值最大；筒式工作状态下，间隙D的相对差值最小。进一步地，间隙D在单位磁动势下产生的制动力矩最大，表明该工作状态下制动器的能量利用率最高。研究结果为T型结构磁流变制动器的设计研究提供了理论参考