Study on A Novel Shunt Hybrid Active Power Filter

随着越来越多的非线性负载被应用到工业生产中，电网受到的谐波污染日益加重，因此对谐波治理的研究愈发受到重视。工业上抑制谐波畸变最常用的方法是采用无源滤波器（passivefilter，PF），但是PF存在补偿效果对负载有依赖性、使用不够灵活、容易引发串联和并联谐振等缺点。有源电力滤波器（activepowerfilter，APF）能够克服PF的缺点，被认为是解决电力系统谐波问题最有前途的方法之一，但是其成本较高。混合型有源电力滤波器（hybridactivepowerfilter，HAPF）兼具APF与PF的优点，因此得到广泛关注。 论文在深入分析混合型有源滤波器研究现状的基础上，以实现工厂低...As more and more non-linear load is applied to industrial production, harmonic propagation has become a serious problem in power distribution systems the most commonly used method of harmonic compensation is passive filter (PF), but PF has many disadvantages, such as the compensation effect dependence on the load, not flexible enough to use, easily lead to series and parallel resonance and so on. ...学位：工学博士院系专业：物理与机电工程学院_机械电子工程学号：1992010015399

Research on Three-phase UPS with Unbalanced Load

三相电压的对称输出是衡量交流电源性能的一个重要指标。提出了一种新型的三相UPS逆变器系统,利用Δ/Z0型变压器为三相不平衡负载造成的零序电流分量提供通路,再通过设计正、负序双PI控制器抑制不平衡负载中负序电压分量。从而解决零序电压和负序电压造成的三相电压不平衡问题,使该三相UPS逆变电源系统可带三相不平衡负载。试制一台60k VA的三相UPS样机,并给出实验结果。The balanced output of three-phase voltage is an important index to measure the function of alternating current.In order to obtain high-grade output voltage in the case where the load is out-off-balance, this paper analyzed the mechanism and result of threephase voltage caused by unbalanced load, and some existing solutions to solve this problem. A new three-phase UPS inverter system is also raised which use △ /ZO transformer to provide a current path for zero-sequence current that caused by three-phase unbalanced load. What's more, it controlled the component of negative sequence voltage in the unbalanced load by designing the doubled PI controller(of positive and negative sequence). In these ways it could solve the imbalance of three-phase voltage caused by Zero-sequence voltage and,making the three-phase UPS inverter system able to load the three-phase unbalanced load. A 60 k VA three-phase UPS prototypes was built and the results were given based on the experiments

Anti-earthquake Analysis of Nuclear-class UPS Based on HyperWorks

核级UPS是核电站的重要设备之一,对核电厂的安全稳定运行起重要作用。为保证设备质量和可靠性,核级UPS需要进行抗震强度分析确保其通过抗震试验鉴定,使其满足当电厂实际发生地震的烈度在鉴定试验抗震响应谱的包络范围内设备能够安全运行。使用HyperWorks软件对核级UPS进行结构抗震强度分析,以确保其结构设计满足核级设备的抗震要求。The nuclear-class( 1E class) UPS,as the significant power supply in nuclear power plant,plays a dual role in protecting and controlling the power supply,which is vital to the safe and stable operation of nuclear power plants. In order to improve reliability of power supply,UPS of nuclear power plant requires enough anti-earthquake ability,which means that the mechanical properties of the UPS during the process of designing and producing should be fully considered. What 's more,for ensuring the safe operation of equipment,it is indispensable for effective structural strength analysis and anti-earthquake analysis to make UPS cover earthquake response spectrum of given. In this paper,we innovatively use Hyper Works software into structural anti-earthquake intensity analysis of nuclear-grade UPS,to ensure the structure design satisfies the demands of nuclear-class devices

Damage to Alexandrlum tamarense DNA Caused by Hydroxyl Radicals

利用羟基自由基(·OH)压载水处理系统,采用大气压强电场放电技术制取·OH溶液对塔玛亚历山大藻(Alexandrlum tamarense)进行处理。通过普通光学显微镜,荧光显微镜和电子显微镜对·OH处理前后的塔玛亚历山大藻的细胞结构进行观测。结果表明,·OH能有效破坏藻细胞,从而造成藻类死亡。利用随机扩增多态性DNA(random amplification polymorphic DNA,RAPD)和实时定量PCR(RT-PCR)相结合的技术检测·OH对DNA链的破坏作用。共得到了3条有显著差异的扩增产物。这3条扩增产物经测序,并通过NCBI(national center of biotechnology information)的比对分析,最终得到1条可用RT-PCR检测·OH对DNA破坏作用的基因序列。以上的结果表明,·OH压载水处理系统能有效去除塔玛亚历山大藻,并对其DNA造成破坏。This paper referred to a ballast water treatment system by using hydroxyl radical(·OH),in which the atmospheric pressure electric discharge technology was applied to produce hydroxyl radicals to treat Alexandrlum tamarense.The morphology of A.tamarense before and after being treated by ·OH was observed by ordinary optical microscope,fluorescence microscope and electron microscope,respectively.The findings presented that ·OH effectively did damage to the algal cells and led to algae perishing and the damage of ·OH to DNA strand was detected by using combination of random amplified polymorphic DNA(RAPD)and RT-PCR technology.In addition,three DNA bands with differences were found and sequenced;then sequence alignment was performed in the website of National Center of Biotechnology Information(NCBI).Finally,a gene sequence was found for RT-PCR analysis that further proved the damage to DNA strand.In conclusion,the ballast water treatment system of ·OH was capable to removes A.tamarense in water effectively,causing damages of the DNA strand.中国杰出青年学者基金(NSFC)(61025001);; 中国国家科技支撑项目(2013BAC06B00);; 海洋科学研究公共利益的专项基

Iron and manganese oxides enhance electron output efficiency of Clostridium pasteurianum

[Background] Fermentative dissimilatory metal-reducing bacteria, which are capable of reducing metallic oxides, get energy from fermentation. Little is known about how metallic oxides affect electron output efficiency of fermentative dissimilatory metal-reducing microorganisms. [Objective] This study was conducted to explore the influence of iron and manganese oxides (Fe_2O_3/MNO_2) on electron output efficiency. [Methods] Different concentrations of Fe_2O_3/MNO_2 were added into fermented system containing glucose and inoculated 5% C. pasteurianum. Electrochemical activity of C. pasteurianum was detected. The concentrations of Fe(Ⅱ) and Mn(Ⅱ) were measured by ferrozine spectrophotometry and formaldoxime method. Fermentation substrate and metabolites of C. pasteurianum were detected by gas chromatography and high performance liquid chromatography. Lastly, we calculated the electron output efficiency. [Results] The current density peaked with the value of about 0.93 mA/m~2. The concentrations of Fe(Ⅱ) and Mn(Ⅱ) gradually accumulated. The consumption of glucose was increased by 9.4%/7.7%, Meanwhile, acetate production was increased by 37.5%/25.0%, and butyrate production was increased by 22.7%/6.8%. Additionally, hydrogen production was increased by 21.6%/9.8%, and the total electron output efficiency was increased by 24.27%/10.82%, respectively. The pH values between experimental group and control are no significant difference. [Conclusion] This study shows that iron and manganese oxides can improve the electron output efficiency of C. pasteurianum by increasing glucose consumption and buffering pH value. The results provide evidence for revealing the effects of multivalent metal oxides on the electron output of fermentative dissimilatory metal-reducing bacteria, and further expand our understanding of the interaction mechanism between multivalent metal oxides and fermentative dissimilatory metal-reducing bacteria.</p

理解模糊概念的动态特征

本文探讨了不同场合下人脑理解模糊概念(量词、修饰词)的动态特点,并且考察了不同赋值区间(论域)、比较级的基数、上下关联(Context)等变量对理解给定的模糊概念的影响,特别考察了上述问题上的年龄差异。</p

澄江学派传人黄宗勖先生针灸学术特色

黄宗勖师从澄江针灸学派创始人承淡安先生,是福建针灸名家。通过收集整理黄宗勖先生的论文和医案,发现其针灸学术特色主要表现为:重视经络,辨证论治;重视得气,善用补泻;重视调理脾胃,针药结合,治各科疑难杂症;擅用外治法,且善用透穴;重视养生保健,善出食疗奇方

A级数据中心综合能源系统多目标优化设计和调度

采用分布式综合能源系统取代数据中心的传统供能系统,是降低数据中心运行费用的有效措施。考虑A级数据中心的供能可用度,设计了一种分布式综合能源系统,并基于混合整数非线性规划方法,建立了综合经济和环境效益的多目标优化设计和调度模型,选取ε-约束法对相互制约的多目标问题进行处理,在通用代数建模系统(GAMS)中建模并调用LINDOGLOBAL求解器进行优化求解。采用多维偏好分析线性规划决策法从非劣解集中选出最终解,并通过逼近于理想解的排序方法进行验证。算例结果表明,优化后的分布式综合能源系统能够保证A级数据中心的供能可用度,同时在降低年总费用和减排二氧化碳方面均具优势

钛酸纳米管前驱体水热制备TiO_2:水热媒介对结晶度及光催化活性的影响

以钛酸纳米管为先驱体,180℃24 h同一水热条件下,利用H2O、HNO3、KBF4以及HNO3+KBF4的4种水热媒介溶液,制备了高结晶度高光催化活性的TiO2,并研究了水热媒介对TiO2结晶度、表面羟基和光催化活性的影响。通过扫描电镜(SEM)、X射线衍射(XRD)、红外测试(FTIR)、X射线光电子能谱(XPS)、紫外可见漫反射吸收光谱(UV-Vis)进行了结构表征。光催化活性通过降解甲基橙溶液进行了评价。结果表明,与其他3种媒介相比,HNO3+KBF4溶液为水热媒介制备的锐钛矿晶型TiO2,结晶度高,表面羟基含量高,因此,呈现高的光催化活性

Study on the corrosion effect of ballast tank caused by ballast water treatment of hydroxyl radical

针对羟基自由基(·OH)法处理船舶压载水过程中可能对压载舱造成腐蚀情况进行研究。在最大羟基处理浓度2.5 Mg/l条件下作用压载舱常用低碳钢、不锈钢及非金属材料,检测处理前后压舱水对压载舱材料的腐蚀影响。结果表明羟基法处理压载水系统在高效杀灭外来有害生物的过程中,对压载舱金属与非金属并不具有明显的腐蚀增强,这一结果满足IMO的技术要求。羟基法在快速处理船舶压载水的同时对于压载舱壁金属腐蚀而言是安全的。该研究结果对日后压载舱的防腐设计以及压载水处理装置在船舶上的推广应用具有重要的意义。The thesis presents the study of the situation that hydroxyl radical( ·OH) may cause the corrosion of ballast tank material in the process of ballast water treatment.Under the highest using concentration of hydroxyl radical,the materials,such as low-carbon steel,stainless steel,and Non-metallic,are commonly used in the ballast tank to evaluate the corrosion influence that ballast water makes on the materials of ballast tank in the pre-and post-treatment testing.The result showed that the corrosion effect of the hydroxyl radical on the metal and non-metal materials does not increase obviously when used in the system of ballast water treatment to effectively kill the exotic pests,which meets the requirements of IMO.It is safe for ballast tank wall metal to utilize the hydroxyl radical in the ballast water treatment.The study result holds a great significance for the anti-corrosion design of the ballast tank and the popularization as well as the application of this ballast water treatment system on board.国家高技术研究发展计划(2012AA062609); 国家杰出青年科学基金资助项目(61025001