关系数据系统
- 与 关系数据系统 相关的网络例句 [注:此内容来源于网络,仅供参考]
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The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.
本文研制了用于真空度检测的高频脉冲电源,通过Simulink仿真和试验检验其满足设计要求,实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出;利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集,通过异步串行通信实现单片机与计算机之间的数据通信,将检测数据传至上位机;在上位机利用Matlab开发人机交互界面,实现相关数据处理和图形显示,包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。
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The article begins with data model, with the theories of binary relation, function dependence and Fan's, establish the measures of query and the safety of database, which provides theories for developping DFDS in de...
论文根据钻探泥浆数据库系统的开发要求从研究数据模型入手,利用二元关系、函数依赖及范式理论对数据模型进行较为详细的分析,建立了数据库的查询优化措施和安全方法,为钻探泥浆数据库的具体设计提供了理论依据。
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They can be classificated to two kinds. One kind is build by photomultiplier; another kind is build by MCP. The mechanism of delayed luminescence is discussed with subradiation. A photon count system is built. To proof the biophoton is a kind of ultra weak photon stream originate from exothermic reaction, and primarily discuss the relationship between the delayed luminescence and proteins activity, we chose microphyllous banyan leave , ficus elastica leave, gingkgo leave, Chinese fan palm leave, and cinnamomum camphora leave as biological samples. The ultra weak photon emission from normal biosamples, and proteins inactivated biosample were measured separately with photon count system. The results showed that the delayed luminescence of biosamples have
在研究过程中,作者从辐射陷获的角度讨论了延迟发光的产生机制,对生物光子的生物化学起源与相干场起源的统一性进行了探索;自行搭建了单光子探测系统;测量了小叶榕树、印度橡树,银杏树,蒲葵树香和樟树等多种植物叶片样品的延迟发光,获得了大量实验数据;为了证明生物光子是一种起源于放热化学反应能量释放的微弱光子流,并初步探讨生物蛋白活性与延迟发光衰减之间的关系,测量了正常生物样品、生物蛋白灭活样品的延迟发光,同时测量了多种不含蛋白质的无机化学体系作为比对,实验结果和实验数据的回归分析表明:弱光子发射来源于放热的化学反应,延迟发光的强度与衰减时间与生物蛋白活性密切相关。
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Therefore it is necessary to research the mechanism of greensand used for high compacted molding methods thoroughly.This subject is one section of the National Natural Science Foundation subject ""Ivestigation on Predicting Method and Mechanism of Springback for High Compacted Sand Molds"", followed of the other completed one named ""Research on Microdeformation of Molding Sand"". A serious of experiments has been done on the reequipped three axial machine under certain technological conditions, and the mechanics, material science, rheologic science. It is systematically studied that the influences on the springback of sand mold were caused by the main influence factors: pressure, compacted rate and the content of soil. Through the analyzed experiments' data, the experienced stress-strain relationship concerning the main influence factors were obtained;under different technical parameter, the springback and spingback's potential energy are compared, the differences and indifferences between them are found out, and the springback's mechanism is discussed;according to the tests' data of YangGuoping coming from Tinghua University, experienced formula of molding sand's springback displacement is induced, the displacement and springback are compared, the margin of error's reasons are analyzed, and they are tested and verified mutually.
本课题为国家自然科学基金项目"高紧实度砂型预测方法及回弹机理的探讨"的一部分,是已结题的国家自然科学基金项目"铸造型砂微变形的研究"的后继,运用力学、材料学及流变学理论,利用改装的三轴仪,在一定的工艺条件下,作了大量系列实验,系统的研究了压实比压、紧实率和膨润土含量对砂型回弹的影响;对实验数据进行了分析和处理,得出了型砂关于压实比压、紧实率和膨润土含量的本构关系的经验公式;把各工艺参数下的型砂产生的回弹量与回弹势能进行比较,找出两者存在的异同点,并对回弹机理进行了探讨;通过清华大学杨国平的实验数据,推导出型砂回弹位移场的经验公式,并与实验测出的回弹量进行比较,分析误差造成的原因,并互相进行了验证。
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The system adopts relational database tomanage spatial data, which is convenient for intercurrent operation and safety control of spacialdata.
系统基于Windows操作系统,采用关系数据库来管理空间数据,便于空间数据的并发操作和安全控制。
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The data studied by concept lattice theory and rough set theory are expressed by information system and formal context respectively.
粗糙集理论的数据表现方式是信息系统,其研究基础是对象之间的等价关系;概念格理论的数据表现方式是形式背景,其研究基础是一种有序的层次结构——概念格。
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Systemic studies environment temperature how to influence construction control, finds out linear regularity and function formula of the arch rib, selects optimal closure time, then fully meets requirements of closure precision and linear. By testing a lot of data on temperature and strain and adopting least squares collocation, this dissertation deduces the strain calculate formula that is amended by joining temperature factor, then improves accuracy of stresses testing data.
系统地研究外界温度变化对施工监控的影响,找出了拱肋变化的线性规律和函数式,选择出最佳合龙时机,保证了拱肋的合龙精度和线形要求;测试了大量温度与应力对应关系的实验数据,采用最小二乘拟合推估法,推导出温度修正后的应变计算公式,从而提高了应力测试数据的准确性。
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In addition, the system can draw the relevance picture of experiment data, and make variance analysis and verification of notability of these data.
另外该系统实现了仿真试验数据关系图形的绘制及仿真试验数据的方差分析和因素显著性检验等功能。
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Smilax, there are the phylogenetic relationships and distributive pattern to be found based on the combined ITS and maiK. tree: 1 a clade with the African species (S. kraussiana) and Australian species (S. australis), being a sister group; 2 a clade with the S. zeylanica of sect. Macranthae and S. bona-nox of sect. China, the former from Southeast Asia and latter native to US, showing they are a sister species which is disjunctive between Asia-North America, similar to the species pair of S. hispida and S. sieboldii; 3 S. perfoliata from Indonesia being sister to S. ocreata of China and S. megacarpa of Indonesia, which are very similar to each other in morphology; 4 the three species from China (S. lanceifolia, S. perfoliata and S. chapaensis) and S.ovalifolia from Indonesia showing a 87-92% bts monophyletic clade; 5 S.bracteata from China and two species of Indonesia (S. leucophylla and S. sp.) forming a clade in the ITS tree; 6 S.
通过比较研究圆锥花序组和穗菝葜组的地理分布,基于ITS及matK联合数据构建的系统树发现下列明显的具系统发育关系的类群及地理分布模式:1来自非洲的S.kraussiana和来自澳大利亚的S.australis是一对姐妹群,具有共同的祖先;2圆锥花序组的S.zeylanica和菝葜组的S.bona-nox形成一个紧密的分支,前者分布于东亚而后者只局限于美国,显示了一种类似于S.sieboldii和S.hispida那样的东亚—北美间断分布模式;3印度尼西亚的S.perfoliata是分布于中国的S.ocreata和来自印尼S.megacarpa的姐妹群,这三者在形态上也非常接近,表明具有共同祖先;4来自中国的三个种(S.lanceifolia,S.perfoliata and S.chapanensis)和来自印尼的S.ovalifolia形成了一个高支持率的单系分支(87-92%bts);5基于ITS的系统树,来自中国的S.bracteata和来自印度尼西亚的两个种S.leucophylla and S.sp。
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In this paper, the concept of systematically using component technology integrate test systems is brought forward at home for the first time. And the Open Data Acquisition Standard is also introduced, the framework of which, the implementation and management technologies of the ODAS driver are provided in this paper too.
本文在国内首次从系统的角度提出了使用组件技术进行测试系统集成的设计思想;首次引进了开放式数据采集标准,并且对标准的层次关系、技术实现以及系统管理等问题展开了分析研究,提出了符合标准要求的软件设计与管理技术。
- 推荐网络例句
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The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.
采用不同浓度K2CrO4(0,0.4,0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗,测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。
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By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.
通过分析数学形态学在图像中的理论基础,研究二值图像的形态分析算法,探讨最小结构元素的两种基本形态:膨胀和腐蚀;分析了数学形态学复杂算法的基本原理,把数学形态学的部分并行处理理念引入到家实际应用中。
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Have a good policy environment, real estate, secondary and tertiary markets can develop more rapidly and improved.
有一个良好的政策环境,房地产,二级和三级市场的发展更加迅速改善。