A coordinated state transition control strategy for microgrid with multi-energy generation systems

A coordinated control strategy is proposed based on state transition for a microgrid containing continuous or intermittent DG, energy storage device and sensitive loads. According to the available operation states, a scheme of operation state transition is established through setting the current operation state and trigger event as inputs of MGCC and regarding the control modes of components as outputs. By considering the no deviation control for frequency and the capacity limitation of energy storage device under all operation states, control modes of components and trigger events of state transition under all defined states are designed respectively for a reliable power supply of sensitive load. The PSCAD/EMTDC simulation software is used for analysis of the three typical transition processes of operation states. The results show that the proposed coordinated control strategy is effective for a safe and reliable power supply to the sensitive loads and ensures a smoothing transition between operation states of microgrid as well as the no deviation control of system frequency.     

New Operation Method of 35 kV Power System in Mountainous Area

The unbalanced nature of 35 kV distribution system due to capacity values is difficult in neutral operation, which can not meet the demand of voltage balance in static state and arc distinct in fault. This paper proposes a new neutral operation as neutral insulation in static state and resonance grounding in fault , along with EMTP simulation acts. Simulation indicates that new neutral operation method can improve lightning withstand level and decrease trip-out rate of grids.     

Solving the Operation Directing Expert Systems Based on Characteristic Model

In this thesis,aiming at the characteristic of operation directing expert systems,we use the state of process characteristic parameter to describe the process condition(state).We propose a solving strategy batal on characteristic model.According to the solving-tree of process condition (state),the present process state can be obtained. An example of application illustrates that this method solves problem quickly and satisfy the real time directing operation.     

钝化剂对农田土壤重金属形态与其稳定性影响研究

钝化剂因其处理成本低廉、效果快速、操作简单和不影响农作物生产等优点而受到广泛关注。常见的钝化剂主要为石灰性物质、炭材料、粘土矿物、含磷材料、有机肥等。施用钝化剂后使土壤中的重金属可交换态、碳酸盐结合态、铁-锰氧化物结合态、有机物结合态和残渣态发生改变,降低其生物有效性。不同钝化剂对农田土壤中的重金属形态影响的稳定性存在一定差异。高污染土壤中施用的钝化剂可能会被污染物所饱和,其钝化容量有限,随着时间延长,钝化效果不明显。钝化剂对农田土壤重金属形态影响的稳定性持续时间仍有待探究。     

Experimental Study of Aseismic Behavior of EccentricalReinforced Concrete Columns with Concrete Cover

Based on experimental study of 2 reinforced concrete columns with consolidated reinforced cover under cyclic loading action,this paper describes the influence of initial stress state and construction measure at binding surface on loading capacity of the column and puts forward a few consturction measures to ensure integral operation of both old and new parts.     

中国发展现代农业的背景及思路

通过对现代农业概念和特征的阐述,分析了中国现阶段必须发展现代农业的3个主要原因,即只有发展现代农业才能保障中国的粮食安全、只有发展现代农业才能提高中国农业的国际竞争力、只有发展现代农业才能不断地增加农民收入。结论为中国发展现代农业需要处理好的四大关系、发展现代农业需要有现代农业制度的支撑、发展现代农业需要相关产业和科技的支撑、中国发展现代农业需走内涵式规模经营道路。     

Discussion about Saving Energy in Refrigeratory

Food refrigeration is regarded as a high energy consuming trade. Under the long period system of state operated enterprise,there are many phenomenons of ignoring energy management and wasting energy. Energy consuming is not very clear for production.Consuming in our country is far more than the international standard and there is a distance between the middle_westland and the eastland. As a enterprise that faces the international market,it is important for it to strength the management so that the cost can be reduced. Considering those phenomenons of ignoring energy management and wasting energy in refrigeratory at present, some measures such as improved the unreasonable operation process, strengthening the energy management and automation to realize automatizing operation are improved to reduce the cost for refrigeratory trades.     

污泥膨胀的原因及其控制方法

污泥膨胀不仅影响出水水质,增大污泥的处理费用,而且极易引起大量污泥流失,严重时可导致整个处理工艺失败。污泥膨胀分为丝状菌性污泥膨胀和非丝状菌性污泥膨胀,主要影响因素有污水水质、溶解氧、污泥负荷、冲击负荷以及运行方式和处理工艺等。通过临时控制措施、工艺设计控制措施、工艺运行控制措施可有效解决污泥膨胀问题。尽管当前有一些理论解释污泥膨胀问题,如表面积/容积比(A/V)假说,动力学理论,饥饿假说理论、NO假设,但缺乏充分的实验证明模型适用与否。需进一步完善污泥膨胀理论,为控制污泥膨胀提供严谨的理论依据。     

Analysis of salt rock underground deposit failure probability in operation period based on response surface method

For the safety of salt rock underground deposit, uncertainties and their influences are considered, and failure probability during operation period is analyzed. Based on finite element model, equation of limit state surface is transformed into explicit equation by response surface method. Combined with Monte Carlo method, computation efficiency is improved. The deposit could be simulated as a series-parallel system. The element with highest failure probability is determined first, then failure mode and system reliability are computed. Taking Jintan underground gas deposit as an example, the analysis indicates that as storage pressure increases, failure probability of middle part of deposit decreases firstly, then increases gradually when storage pressure accumulates to a certain extent. The failure probabilities of upper part and underside of deposit increase as storage pressure increases. During operation period, controlled failure mode is shear failure of upper part and underside of deposit under high storage pressure. In conclusion, the storage pressure during operation period should be controlled strictly.     

热风炉换热系统的热工特性

介绍了干燥热风炉的概念,分析了热风炉的设计现状。通过与加热炉的对比,阐述了热风炉操作参数的特点;基于换热器在热风炉上不可替代的地位,从热工理论出发,分析指出了热风炉用换热器与余热利用换热器的主要区别。     

Operation of Debt-to-equity Swaps in State-owned Enterprise: a Game Theory''s Viewpoint

Operation of Debt to equity Swaps are thought to be a game process of conflict of interest when concerned interest groups seek furthest uses of them and dispute eminent domain of financial resources if state owned enterprise's property right configuration is not to be changed. That is to say, operation of swaps of debt to equity is one game between commercial bank and state owned enterprise firstly, and then it is another game of actualizing contract between AMC and stated owned enterprise. So the corresponding models are constructed according to game theory. The result indicates that enterprise and bank can compass an equilibrium and come to an agreement of swaps of debt equity. Nay, AMC must build up hawkish visualize to supervise and control enterprise's financial affairs and management in order to gain dividend and rights of section is bought back.     

利用盘式吸渗仪确定土壤水力学参数研究进展

各种农业措施显著影响土壤的物理性质,特别是土壤水力学参数。随着计算机模型广泛用于土壤物质迁移的预测预报,准确确定土壤水力学参数成为一项重要的研究任务。盘式吸渗仪作为一种简便实用的仪器正被广泛用于田间土壤水力学参数的测定。国内外学者研究了稳态、瞬态和反推等方法,利用盘式吸渗仪来确定土壤近饱和导水率、吸渗率和水分特征曲线。同时该仪器可以用于田间测定土壤孔隙分布状况,以及两区模型中的参数。笔者对国内外有关盘式吸渗仪研究从相关理论和应用方面进展进行了综述,并对田间测定操作中注意的问题进行评述,指导田间试验以获得准确的测定数据。盘式吸渗仪在田间测定土壤孔隙,特别是大孔隙流方面有独特的优点,但是其并未在中国不同质地土壤上得以广泛应用。     

宁波市油菜生产现状及发展分析

本研究通过梳理宁波油菜生产现状,总结出油菜生产发展在面积、产量、效益、市场4个方面具有巨大潜力。当前油菜生产主要面临种植效益低、政策扶持力度小、生产风险大以及产业化经营滞后等方面的制约。为此,提出了推广新品种新技术应用、加大政策扶持力度、加强当地产菜油品牌建设、加快开发油菜种植多样性功能等对策,旨在为宁波油菜生产发展提供技术支持。     

Analysis of the Ground Adjustment Ability of the Ground Source Heat Pump Systems in Winter

Based on an actual ground source heat pump system in hot summer and cold winter area, the system operation parameters were tested for 6 years under the state of using cooling tower for cooling in summer but the ground heat exchanger and fire pool for heating in winter. A three dimensional (3D) tube group model was established, and the thermal balance analysis and calculation of the ground temperature distribution around the ground heat exchanger were conducted by the numerical calculation. According to the comparison between the test data and the theoretical results, the influencing factors of the ground adjustment ability were obtained.     

Method to Determine the Intersection of Two Arbitrary Solid Polygon With Node Operation

The method to polygon' intersection is applied in computational geometry, computer graphics, GIS, evaluation of geo-hazards and civil engineering. Based on the node state of polygon, the authors propose the method and algorithm of polygon' intersection, the key to which is node operation. This method's concept is simple; and it is easy to computer program's implementation. It avoids to singular problem of Boolean Operation, and is easy to solve the problem of overlapping side and sides intersecting in node of polygon. For the arbitrary way of intersecting of arbitrary solid polygon, this method is accurate and general.     

An Analysis of ESO and Manager Behavior by Game Theory

After reform of state -owned firms mechanism, many companies appeal for ESO, but there have not been any clear theories for operation in practice until now. On the basis of principal-agent theory of the firm, this paper regards owners and managers as the two sides to game and builds the game model which analyses the behaviors of owners and managers. As a long-term stock based incentive system, ESO will align the goal of owners and managers and make them reach Nash Equilibrium to maximize their utility, and lower agency cost to solve the agency problem in modern firms.     

Microbial Community Structure and Ecological Variation in TISTD Reactor

Based on the sewage treatment device of Two-phase Integrated Sludge Thickening and Digestion reactor (TISTD), microbial community structure in stable operation and its ecological variation when load changes are investigated. During a stable operation with 30% sludge dosage rate, 20 dominant bacterial strains are individually isolated from acid-phase and methane-phase of the reactor. Sequence analysis of 16S rDNA reveals that six of the achieved strains belong to Bacillus, Methanospirillum and Methanococcus respectively. Ten sludge samples are collected separately in 5 periods when the reactor operates with 10%, 20% and 30% sludge dosage rate and in the state of started-up and disordered, and followed by DNA extraction, purification, 16S rDNA PCR amplification and temperature gradient gel electrophoresis (TGGE). The good quality of DNA extraction and amplification demonstrates that there is an abundant biomass in the sludge under mid-temperature condition. The results show that TISTD reactor has a high biodiversity in microbial communities and is complex and stable in ecosystem structure, which effectively supports the good digestion in sludge thickening.     

Numerical Simulation of Fluid Flow in Converter Combined Blown Bath

The fluid flow mathematic models in converter combined blown are set up.It is simulated for flow state and velocity distribution of gas and stir action in different behaviours of bottom blown,top blown and combined blown by software PHOENICS(Parabolic Hyperbolic or Elliptic Numerical Integration Codes Series).In normal operation condition of ejection guns,the fluid flow in bath is axisymmetric three-dimensions flow.The results reveal out dynamic main area and slowness cyclone zones,also asked dead zone abating or erasing in practice.These shows that bottom blown gun ought to 0.5~0.7 circumference diameter of fused bath using top-bottom combined blown process.     

风险社会中农民的风险意识与应对策略研究

现代农村已进入风险社会。进入农村的风险包括生产风险、生活风险和生存风险。农民对生活风险感知最强烈，对生产风险次之，对生存风险感知最深刻。面对风险，农民逐渐形成了依靠自己和体制外资源规避风险的风险应对策略。他们基本不能利用社会保障机制和商业保险来分散面临的各种风险，使他们的应对策略效果受到削弱，如何使他们享受到社会保障制度的福佑，如何使他们积极的利用商业保险来规避风险对国家制度建设和保险公司的商业运作提出了迫切的现实要求。     

Research and Application of Temperature-field Digitalizing of the Tuyere and Raceway Section in Blast Furnace

It is useful for diagnosing coal combustion status and the tuyere and raceway in blast furnace, at the same time, it is supervision running state to study on temperature-field of also helpful for supervising the structure of oxygen and coal burning apparatus, improving coal combustion technology and coal injection operation. The model between red and green information of true color flame image and temperature is established and two dimension raceway section projection temperature-field are achieved by applying no-touch radiation temperature measurement theory and technology. It is proved with experimentation that the method is effective and feasible, and the testing precision can reach 98.09% compared to the testing result of thermocouple of taking out gas.