基于GIS的低温冷冻灾害风险性评估

为了提高低温冷冻灾害的防御能力,为政府部门制定防灾减灾规划提供科学依据。本研究基于自然灾害形成机理及风险评估原理,以济南市长清区为例,利用气候资料、历史灾情数据、地理信息数据及社会经济等资料,采用层次分析法和加权综合评价法,借助GIS空间分析技术,通过对致灾因子危险性、敏感性、易损性和防灾减灾能力4个评价指标的空间评价,实现了对长清区低温冷冻灾害的风险性评估和综合区划。结果表明：长清区低温冷冻灾害总体表现为空间化强,没有规则的分布规律,综合风险性总体水平较高。文昌街道办事处、五峰山街道办事处、双泉乡的部分地区综合风险性最高,属于低温冷冻灾害的重点防御区域;轻、低风险主要分布在平安街道办事处、万德镇、马山镇、崮云湖街道办事处的部分辖区。该评估结果将对本地区农作物的种植规划及灾害防御措施的制定提供参考依据。     

油菜MICMS恢复基因近等基因系的构建与近等性分析

以宁R7为恢复基因源,利用连续回交法构建以T78、T84和ZS9三个优异种质为遗传背景供体的近等基因系候选株系。于成熟期考察并比较候选株系农艺性状,同时采用SSR标记对候选株系进行PCR扩增估算遗传相似系数并进行聚类分析。农艺性状分析(t测验)表明,不同候选株系与其供体的农艺性状具有不同程度的相似性,株高和分支点高度的差异程度较其他性状高。采用75对SSR引物对21个候选株系PCR扩增共得到157个目的片段,发现三个遗传背景候选株系的平均遗传相似系数分别为0.86、0.92和0.98。农艺性状与SSR标记综合分析后,认为wh13、wh59和wh118分别为三个种质的最优近等基因系。综上表明,采用农艺性状比较与分子标记相结合分析近等性是一种有效的近等基因系的检测方法。中选近等基因系可用于恢复基因的定位及克隆。     

小麦Glu-B1位点1Bx14+1By18新亚基对材料的创制及其对加工质量的影响分析

以小偃54为轮回亲本,以引进品种Prinqual为1Bx17+1By18的供体,培育高分子量麦谷蛋白亚基（HMW-GS）近等基因系,以期客观评价1Bx14、1By15、1Bx17和1By18等亚基（对）对小麦加工品质的贡献。近等基因系回交至BC₄代时发现一个1Bx17亚基不表达的重组体,该重组体经自交分离纯合后获得了携带新亚基对1Bx14+1By18且可稳定遗传的品系012912。采用SDS-聚丙烯酰胺凝胶电泳（SDS-PAGE）、酸性聚丙烯酰胺凝胶电泳（A-PAGE）、小麦SDS微量沉降值和面粉揉面仪等方法。对小偃54和012912的谷蛋白及醇溶蛋白组成、总蛋白质含量、沉降值和揉面特性等指标进行了比较,结果表明,012912（1Ax1, 1Bx14+1By18, 1Dx2+1Dy12）与其轮回亲本小偃54（1Ax1, 1Bx14+1By15, 1Dx2+1Dy12）在谷蛋白成分上的唯一差别是以1By18替换了小偃54的1By15亚基,且1By18基因的表达量比小偃54的1By15表达量提高29%;012912品系的沉降值比小偃54高2.5 mL,揉面特性比小偃54好,说明1By18基因比1By15对面团加工品质的正向效应大。     

基于主成分分析的湖北省洪涝灾害风险评估模型构建

湖北省历年由洪涝灾害造成农作物受损严重,对湖北省进行洪涝风险评估十分必要。本文提出了一种定量化风险评估的模型建立方法,通过多源数据（气象、社会经济、地理特征等数据）提取到15个指标,采取主成分分析法确定各因子对于洪涝灾害的影响权重,建立风险评估模型,并运用地理信息系统(GIS)分析技术得出洪涝灾害风险区划图。在现有评估指标体系的基础上,通过网络爬虫方式获取更能反映防减灾能力的灾害应急指标;采用主成分分析方法降低模型建立中的主观因素。结果表明：（1）通过模型得到降雨与地势为湖北省洪灾发生的最主要因素;（2）湖北省中东部地区多为高风险区,其中东部武汉、黄石等长江干流途经地区处于重风险区;西南部多为中风险区,西北部在全省为低风险区。综上,该模型可为湖北省开展综合减灾、调整区域可持续发展结构、进行准确农情监测提供科学支撑和决策依据,具有重要的科学和实践意义。     

基于Maxent模型的棉花曲叶病在中国的适生性分析

棉花曲叶病是棉花上一种毁灭性的病害,其主要病原木尔坦棉花曲叶病毒(Cotton leaf curl Multan virus,CLCu Mu V)已入侵我国广东、广西、海南、福建、云南和江苏等地,明确其可能的适生区域对该病毒病的科学监测和综合防控意义重大。本研究以棉花曲叶病的分布数据为基础,综合考虑其传播介体烟粉虱、中间寄主朱槿、寄主棉花的分布区域,利用Maxent模型对棉花曲叶病在中国的潜在适生区进行预测。结果表明,长江流域棉区、黄河流域棉区的大部分区域都属于棉花曲叶病的适生区,而西北内陆棉区的适生程度较低,大部分为低度适生区;其中,高度适生区主要集中在长江流域棉区的湖南、江西、浙江、安徽、江苏、湖北,此区域也适宜朱槿的种植。因此,华南地区已流行危害的木尔坦棉花曲叶病毒向北入侵到我国棉花主产区的风险极高,其中长江流域棉区将是该病害发生及防控的重点区域。     

遵义烟区烤烟气候因子的适生性评价及其与化学成分间的关联分析

旨在找出遵义产区烤烟大田期的气象因子对烤烟化学成分影响的主次关系,为特色优质烟叶生产布局提供理论依据。以2009—2013年贵州遵义烟区的气象数据和烤烟的主要化学成分为基础,运用模糊数学隶属度函数模型对该区的气候适生性进行评价,并运用灰色关联分析法分析遵义烟区主要气候因子与烟叶化学成分之间的关联度。结果表明：遵义烟区的平均气候适生性指数(CFI)均值为0.853,符合优质烟叶的生长条件,但遵义烟区各年份间气候变化大,尤其是年份间各生育期的日照时数和降雨量的变异系数较大,导致年际间烟叶化学成分含量稳定性差。灰色关联分析的结果表明,与遵义烤烟总糖和还原糖含量关联度最大的气象因子主要是各生育期的日照时数,而影响烤烟烟碱和总氮含量的主要气象因子则是旺长期的降雨量。     

三交和双交组合加性-显性-母体效应的遗传模型及蒙特卡罗模拟分析

本文根据广义遗传模型的建模原理, 按照三交和双交组合方式的交配设计, 分别提出了分析作物三交和双交组合数量性状的加性-显性-母体效应的遗传模型(ADM模型), 给出了不同环境下各世代群体的遗传效应分量。 应用MINQUE(1)法对包括不同世代的三交和双交组合的ADM模型进行了蒙特卡罗模拟分析, 结果表明： 采用亲本和三(双)     

基于GGE双标图和AMMI模型对江苏省水稻区试品种的丰产性和稳定性分析

本研究综合利用GGE双标图方法和AMMI模型对2017年江苏省杂交中粳稻区域试验的12个参试品种的丰产性和稳产性进行了分析.结果表明,基因型、环境及基因型与环境互作效应对杂交中粳稻产量有极显著的影响.在所有参试品种中,杂中区03和杂中区12是丰产稳产的广适性品种,可在粳稻适区进行推广.江苏徐淮地区淮阴农业科学研究所试点...     

三交和双交组合加性-显性-母体效应的遗传模型及蒙特卡罗模拟分析

本文根据广义遗传模型的建模原理,按照三交和双文组合方式的交配设计,分别提出了分析 作物三交和双交组合数量性状的加性－显性－母体效应的遗传模型（ＡＤＭ模型）,给出了不同环境下各 世代群体的遗传效应分量。应用ＭＩＮＱＵＥ（１）法对包括不同世代的三交和双交组合的ＡＤＭ模型进行 了蒙特卡罗模拟分析,结果表明：采用亲本和三（双）交Ｆ_１两个世代分析三（双）交组合的ＡＤＭ模型 时,即可获得方差分量的无偏估计值和遗传效应的无偏预测值;采用包括单交Ｆ_１在内的三个世代联合 分析时,更有利于提高显性等遗传效应方差分量的估算效益。最后讨论了利用单交组合预测三交和双 交组合遗传表现的有关问题。     

A reliability evaluation model for photovoltaic/diesel hybrid power generation system

Photovoltaic power generation is considered to be one of the most promising power generation forms. It is difficult to accurately assess the reliability of the photovoltaic system (PVS) for the volatility and intermittent of the light intensity. By analyzing PVS component failure modes and their impacts on PVS output power, the reliability model of PVS is built. Then the probability model of PVS output power is presented by considering both illumination uncertainty and PVS component random faults. According to the influence of components random faults outside the intentional islands on the reliability of load points inside the intentional islands, the concepts of repair zone, isolation zone and zero zone are defined. Furthermore, by considering the fail-operation of breaker and fuse, the concept for zone hierarchy is proposed, and the analytical formulas to calculate reliability indices of the load points inside the intentional islands are deduced. The application of the presented reliability evaluation model is clarified using a typical example to show the practicality and validity of the proposed approach.     

Research on reliability evaluation model for frequency collapse of power grid

In order to comprehensively consider the possibility and the severity of frequency instability risk, this paper proposes the risk evaluation model and algorithm for frequency collapse of power grid. The uncertainties in generating dispatch, network topology and component outage are considered. The calculation method for system frequency variation is depicted while considering the active power deficiency arising from random failure of generating units, and then various probabilistic risk indices for frequency collapse are defined. The presented method can provide important reference information for evaluating the frequency collapse risk of power grid. The non-sequential Monte Carlo simulation-based results of IEEE-RTS79 show the correctness of the method.     

Parameter uncertainty analysis for probability distribution of bulk power systerm reliability

Component reliability parameters are of uncertainty and are affected by the component type, operation time, and weather conditions. So do the reliability indices of bulk power systems. The calculation of its probability distributions and its alteration law affected by parameters uncertainty are researched to provide practical engineering reference with exploring the impact of the parameter uncertainty on reliability assessment. The point estimate method is firstly proposed based on the two-loop Monte-Carlo simulation, and then the improved Monte-Carlo simulation is presented to enhance the calculation efficiency further. Moreover, their theories, merits and faults are explained in detail. It can be seen from the evaluation results for the RBTS power systems that the accuracy of the three methods are similar but the improved Monte-Carlo simulation has the highest efficiency, followed by the point estimate method. The IEEE-RTS 79 power system is evaluated by using the improved Monte-Carlo simulation, and the results verify its validity.     

An optimal equivalent subchannel algorithm for low voltage power line communication system

According to the low voltage power line channel features,combined with adaptive bit loading and power allocation algorithm,an optimal equivalent subchannel algorithm is proposed.Under the condition of fixed amount of transmitted bits and the minimum transmitted power model,impact of optimal equivalent subchannel on the system performance is studied.The optimization algorithm sorts subchannels with similar transmission features into groups,thus the signaling load can be reduced,and the spectrum can be better used.The simulation results show that system can get lower bit error rate(BER) by adopting optimal equivalent subchannel algorithm.     

A power distributed computing system model based on services-oriented architecture

Process communication based power distributed computing model satisfies the demand on real time monitoring and analysis for the economical operation of power grid based on power distributed computation methods, but there are some problems on complexity in common basic functions development and lack of system extendibility. An extendable services-oriented power distributed computation system model is designed and implemented. Software design patterns are applied to design low coupling and extendable system framework. Windows Communication Foundation (WCF) technology is used to implement the services-oriented distributed data communication functions. Windows Workflow Foundation (WWF) technology is used to design the business logic of power distributed computation visually. Data integration functions are implemented by combining the ADO.NET technology. The services-oriented system architecture enhances the integration ability and extendibility. The use of WCF and WWF technology reduces the complexity of the system development.     

The application to simplify the complicated power grid through adjacent two-node equivalent method

Most real power systems are not radial networks and evaluation of the stability often needs to establish electromagnetic transient simulation models. So the network equivalent is required first and foremost. The adjacent two-node equivalent method, which considers the coupling impedance between equivalent nodes, is used to realize the simplification and modeling to complex power grid. The analysis and simulation on both the HVDC system from Deyang to Baoji and a real extra-high voltage AC transmission system in South China shows that the static performance of the simulated system by using the adjacent two-node equivalent method is completely equivalent to the original one, as well as the performance of dynamic equivalent is in a satisfied level. Thus the transient system model simplified can be well established to support research of power grid’s security and stability.     

Reliability evaluation algorithm for complex electrical distribution networks using the storage structure of adjacency multilist

A section algorithm of reliability evaluation for complex medium voltage Electrical Distribution Networks (EDNs) using adjacency multilist (AM) is proposed. The constructing method for AM is introduced. The AM can be used to store the structure data of EDNs and to solve the problem of space & time complexity. A new power flow algorithm of backward / forward sweep is proposed and a fast algorithm of forming sections in distribution network is put forward. The proposed algorithm makes a perfect combination of the power flow algorithm and the section algorithm of reliability evaluation, which makes efforts to decrease the work of programming and saves the computing time. Applying the proposed algorithm in RBTS-BUS6 system and actual EDNs, the reliability assessment results show that the algorithm has an advantage of saving time and possesses efficiency in engineering practicality.     

Approaches to enhance power density of gearboxes for wind turbines

Based on pitting strength, some approaches to enhance power density of gearboxes for wind turbines are discussed. The calculation load is greatly reduced by power division. Allowable stress numbers are effectively increased by improving property of quality materials, precision heat treatment or shot peening. Load capacities can be also obviously enhanced by improving the tooth shape of morphology optimization of tooth root, tooth correction or superfinishing of tooth surface. The center distance is effectively decreased by minishing minimum allowable safety factor or enlarging face width. The power density of gearbox can be further improved by means of structure optimization of planet carrier or uniform load of planetary gear transmission.     

Limitation and improvement of the equivalent capacity method for calculating the energy loss of distribution networks

Through the analysis of the equivalent resistance method, a limitation of the equivalent capacity method was presented. When the direction of power at the feeder source end was changing, the equivalent capacity method for handling small generations would produce a large power loss calculation error. An improved calculation method, one not based on a single equivalent resistance, was proposed. In this method, one day was divided into several periods (such as 24 h), so that the direction of power at the feeder source end for each period does not vary. The equivalent resistance and energy loss in each period were calculated. The sum of all energy losses provided the daily energy loss total. Numerical examples were used to verify the improved method.     

The equivalent enthalpy drop theory calculation of the ejector heaters applied for low-pressure feed water heater system of thermal power unit

There is much exergy loss in low-pressure feed water heater system of the thermal unit. The thermo-economic characters by the equivalent enthalpy drop method while the low-pressure heater was replaced with the ejector heater. At the same time, the thermo-economic characters formulas for the different factors were also gotten. Based on these results, the thermo-economic changing features were analyzed for the low pressure heaters replaced with the ejector heaters of the N600-165/535/535 units, and the results were compared with the normal heat balance method. The results show that the ejector heaters can reduce the exergy loss efficiently, and the thermo-economic effects is the best for replacing the all low-pressure heaters with the ejector heaters, and its efficiency can be increased by 0.263%. The given equations of this paper can be used for analyzing the thermal economic effects.