循环理论

This article proves that a finite cyclic group can be isomorphically represented by direct product of some cyclic groups.

摘要本文运用基础代数中有关循环群、直积、同构等理论，证明了一个循环群可以用另一组循环群的直积形式来同构表示。

Through the heat recovery between the absorber and the generator the COP can be increased and the performance of the absorption system can be improved.

本文对GAX循环的性能进行详细的计算和分析，从循环结构、系统工况、性能变化等方面对氨水吸收式GAX循环进行了理论分析以及数学模拟研究。

It was proposed in the 1960's and developed rapidly in the 1990's. However, some theory problems, for example, the fluid dynamics and mass transfer during the filling up period which could not be dealt with in conventional distillation theories has been remained unstudied. And the simulation and mathematical models have to be made based on some assumptions, which are different from the actual situation obviously. Therefore the further development of DACO was restrained in the past years.

该操作方法自20世纪60年代提出，90年代以来得到了迅速发展，但众多学者的研究基本上集中在优化操作及其与传统恒回流法的比较，而许多重要的基本理论问题至今缺乏研究，特别是传统精馏理论无法涉及的塔内无回流充液阶段的流体力学和传质问题一直没有得到很好解决，导致了动态累积循环操作法的数学模型和模拟计算只能以与塔内真实状况相差很大的简化假设为基础，这严重地阻碍着动态累积循环操作法的进一步发展。

This paper,based on the theory of circular economy,and the experiences of the development in overseas and Tianjin,brin...

本文运用循环经济理论，结合天津发展循环经济的模式以及国外发展循环经济的状况，提出发展循环经济的措施和建议，促进中国新型工业化的发展。

In this thesis, firstly, some main models have been checked on their accuracy, and the reliability of MACORS code has been verified by the RELAP5/MOD2 code on five transient conditions for QSNP: loss of flow; loss of offsite power; incontrollable control rod withdrawal; the feed-water temperature increasing and the feed-water lost. The results obtained are very satisfactory. Secondly, MACORS is used to calculate the operating and accident transients for QSNP, and the analysis results are significant to real engineering. And finally for MNRS, MACORS is used to simulate the steady-state natural circulation heat-removed capacity and the transient behaviors from forced circulation to natural circulation. Some important conclusions are obtained by the analysis results.

本论文首先从各方面对核动力系统中最主要的、热工水力特性最复杂的反应堆和蒸汽发生器进行单独验证和理论分析，其次分别利用RELAP5/MOD2程序和MACORS程序对秦山核电站的双环路失流、全厂断电、反应性事故引入、主给水参数变化及丧失主给水五种瞬态工况进行了计算，结果符合很好，从而证明了本程序模型的准确合理性，选择数值方法的有效性和编制程序的正确性；尔后，利用MACORS程序对秦山核电站的多种运行及事故瞬态进行了分析，得出了具有工程价值的结论；对船用核动力装置的稳态自然循环载热能力以及相应参数的特性、强迫循环与自然循环的过渡工况等进行了仿真分析，所得结论对我国核动力船舶的设计，运行以及安全审评具有重要的意义。

At last the paper realized the advantages and disadvantages of passive solar building and adnvanced some suggestions in future research. From another point, the paper logged the process of the building of the experimental equipment and the mounting of the measurement equipments that accumulated some operating experimence.Carrying experiments, calculating and analyzing the experimental data for more than 2 years, the paper gained some constructive conclusions. In winter the indoor air temperature and RH are lower than comfort criteria, but people feels very comfortable in the passive solar house. The thermo-circulation formed by Trombe wall play an important role in improving indoor air temperature and RH. Based on the analogy analysis theory, the natural convection heat transfer in the air gap can be treated as superposition of two natural convection heat transfer processes occurring over isolated isothermal vertical flat plate, in this case namely the massive wall and glazing. Two empirical formulas for Q and Nu are obtained. The investigation shows that the optimal time to open the damper should comply with the period that the thermo-circulation happens which can be controlled by thermal response characteristics of Trombe wall surface temperature and air temperature in the air gap.

经过两年多的实测和计算，根据传热学、流体力学、统计学等学科的基础理论，对大量数据进行整理归类、分析讨论，主要得到如下结论：(1)冬季，含有特朗贝墙体的被动式太阳房室内热湿环境较舒适性标准偏低，但人体感觉比较舒适，特朗贝墙体形成的热循环通风在调节室内温度和相对湿度方面起到很大的作用；(2)特朗贝墙体空气间层自然对流可以看作是两个等温独立大平板的自然对流换热过程的叠加，通过与大平板自然对流理论类比获得了计算热循环过程中对流换热量的经验公式；(3)特朗贝墙体通风口的启闭可以根据玻璃幕墙内壁面温度、蓄热墙体外壁面温度和空气间层进出口空气温度之间的关系来进行控制，从而有效地阻挡冬季冷循环的发生；(4)夏季，如没有有效的通风降温措施，被动式太阳房内会产生明显的过热。

Circular economy is the up-to-the-minute production of the research of the sustainable development.

本文首先提出了研究的背景及现实意义，循环经济在国内外的研究现状，并对循环经济的产生及发展进行了介绍，从我省煤炭工业经济发展及其对资源浪费和环境破坏的调研入手，在总结国内外循环经济理论与实践的基础上，结合我省煤炭企业特点构建我省煤炭企业循环经济发展模式，并对其进行了经济、社会效益评价。

So the research on the thermo-economics analysis of thermal power plant is significant, this paper focuses on this field and gets some conclusions as follows: Based on Equivalent Enthalpy Drop Method and Cyclical Function Method, a conception, New Heating Steam Flow, is proposed and defined in this paper, which makes it possible to separate the cogeneration circle into condensate steam circle and heating steam circle and to get the new power equation and calculate the Rate of Electrical Power Generation by Heating Steam with Net Equivalent Enthalpy Drop.

在等效热降法的基础上，结合循环函数法的循环分析理论，通过引入热化新蒸汽量的概念，使得常规抽凝供热机组的纯凝汽循环与供热抽汽循环得以分离，从而得出了相应的供热机组汽轮机的功率方程，并实现了热化发电量与净等效热降计算的统一，最终完成了利用等效热降法对供热机组热化发电率的计算，使得已在凝汽机组中应用成熟的等效热降法可以方便地应用于供热机组，进行经济性分析和计算。

It is only under the control of economizing economy that circular production can function correctly, at the same time, as one wrong theory," circular economy" can not be complementary with the theory of economizing economy.

循环型生产只有在节约型经济的统驭下才能正确发挥作用，&循环型经济&作为一种错误理论不可能与节约型经济理论互补。

Firstly, according to the relationship between classic Carnot cycle and Lorenz cycle, the paper evaluates the cycle characteristics and thermodynamic properties of NARMS (Non-azeotropic mixtures), and compares the energy-saving difference between pure and mixed refrigerants. The main of factors that affect heat pump operating efficiency are analyzed in theory and using the Second Law of Thermodynamics the exergy are evaluated in components of heat pump system, in the end a conclusion is drew that all of the exergy have bearing on working fluids' properties.

本文首先从经典的Carnot逆循环与Lorenz逆循环相对关系出发，评估了非共沸混合工质循环的特点以及热力学性质；在不同环境条件下，比较了单工质与混合工质的循环特性差异；针对非共沸混合工质热泵循环效率的主要影响因素（即工质本身的热物性和系统部件特性）进行了理论分析，并利用热力学第二定律对热泵系统的各个主要部件进行了可用能分析，最终发现每一处可用能损失均与工质物性有关；在此基础上提出了减少可用能损失的方法—寻找适宜的非共沸混合工质。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。