转子类大型单件零件的专用数控编程软件研究

工业汽轮机转子加工的特点是单件生产，数控加工转子时每根转子都要编程。转子数控加工编程，无论是手工方式编制加工代码，还是CAM软件编制，都是人工操作，容易出现错误。本文在总结多年加工工业汽轮机转子类零件的经验基础上，分析了转子轮廓数据的特点以及转子加工工艺的方法和要素，并经过实验得出结论：对于这类零件编程的最佳模式就是用专用软件。以由表格式数据输入为主要数据源，其它外轮廓、内轮廓特征数据为辅助数据源，以加工工艺方法为工艺驱动、引导的处理方式自动生成转子数控加工代码。该方式输入方便，校对容易。从而以最少的人工干预，把出错的可能减到最低。

小型盘类转子自动平衡机研制

介绍了一种适用于小型盘类转子，具有自动测量、自动去重、自动检验功能的全微机化的平衡机。阐述了不平衡量的检测原理，提出了一种软硬结合的滤波方法，在自动平衡机的应用中，取得了良好的工程效果。

基于有限元法的盘类转子动平衡机主轴分析

为解决盘类转子的动平衡问题,设计了一种立式的自动平衡机。建立三维机构模型,通过对平衡机关键部件主轴的刚度及振动特性进行有限元分析,得到主轴应力变化规律及变形量的数值,提出对主轴的改进方案,从而简化产品的设计开发过程,减少产品开发费用和成本。根据主轴的振动应力稳定性仿真分析结果,提出一次校正铣削时间周期最大及最优解的合理假设,并对此做出验证,进而提高平衡机整体的校正精度,可为同类型动平衡机部件的设计优化提供理论依据与参考。

基于ADAMS的高速盘类转子动平衡机主轴设计及验证

建立了盘类转子自动动平衡机虚拟样机及总体系统动力学关系模型,根据ISO1940《转子刚体的平衡质量》标准,设定了主轴转子的允许不平衡度与工件不平衡量的设计标准值。基于ADAMS软件对平衡机的主轴套筒进行高速状态下的仿真实验,得到了支撑轴承及主轴在X、Y向的位移及动量曲线,仿真结果表明,虚拟样机满足设计标准的要求,分析了主轴受迫振动时模态变化的三维频响图(FFD)曲线,以此确定动平衡测试结果的可靠性。

盘类转子动平衡机摆架有限元分析及优化设计

通过对平衡机摆架及立柱的有限元分析,得到摆架的应力变化规律,针对摆架的弯形板结构及其材料提出摆架改进优化方案,并对此进行验证。比较摆架优化前后的各项特性的改变,确定改进方案的合理性,进而提高平衡机整体的校正精度。可为同类型动平衡机整体及部件的设计优化提供参考。

盘类转子立式平衡机夹具形式研究

随着发动机技术的不断发展,对发动机上一些盘类转子的动平衡质量要求也越来越高,动平衡工艺已经成为机械制造领域中一项非常重要的内容。通过长期跟踪我公司生产现场的动平衡工序的生产过程,我们对动平衡失效及平衡机故障情况进行了总结,分析了动平衡工装夹具对动平衡测量精度及稳定性的影响,讨论了适合不同类型盘类转子的动平衡夹具结构及装夹方式。

“电偶转子”及类“电偶转子”模型的求解

本文先定义了“电偶转子”和类“电偶转子”两种假想模型概念；然后，在忽略万有引力的情况下，根据数学和物理知识给出了由质量、电量和距离表示的“电偶转子”“电四转子”“电六转子”这3种具体模型的周期公式。这一探讨对优秀学生和物理教师均有借鉴意义。

基于不对称转子结构与序贯田口稳健优化方法的同步磁阻电机设计

目前,传统同步磁阻电机三层磁通屏障的转子设计性能较好、制造简易,得到行业的认可。讨论转子的不对称磁通屏障结构与磁通屏障结构变形对全面掌握同步磁阻电机的特性至关重要,因此该文研究了在不同功率等级下同步磁阻电机不对称设计规律以及基于序贯田口稳健优化方法的类凸极转子同步磁阻电机。首先对传统同步磁阻电机在一定功率等级下优化计算,得出抑制转矩脉动的不对称设计规律;然后根据开关磁阻电机凸极结构,设计类凸极转子同步磁阻电机,应用序贯田口稳健优化方法对采用分布式绕组的12槽8极电机优化得到最优功率等级,并应用至集中式绕组电机,应用磁路模型以及有限元仿真对采用不同绕组的电机作性能对比分析;最后提出一种结构更加简单、制造成本更低的同步磁阻电机。

类椭圆型采油螺杆泵举升性能分析

鉴于对类椭圆型采油螺杆泵举升性能研究较少的现状,建立了类椭圆型采油螺杆泵有限元模型,通过对螺杆泵接触带泄漏位置判定和接触应力计算分析,给出了临界接触应力随低压腔室压力变化的关系式,为该型螺杆泵的举升压力计算分析提供了高效快捷的方法。分析了不同腔室压差情况下临界接触应力与低压腔室压力的关系以及举升压力随螺杆泵级数变化的规律。研究结果表明:类椭圆型螺杆泵最易发生泄漏的位置通常出现在其窄带上,并且均在1/3导程范围内;随着低压腔室压力的增大,临界接触应力随之减小;随着螺杆泵级数的增加,举升压力增大,但增速逐渐变缓,因此在螺杆泵工作时,由下至上,单级腔室对采油螺杆泵举升压力的贡献逐渐减小。研究结果可为类椭圆型螺杆泵的设计提供参考。

直线外包络非摆线型单螺杆泵定-转子成形方法研究

为了提高采油螺杆泵的采油效率并延长其使用寿命,在分析摆线线型定-转子共轭副设计方法的基础上,得出(2∶3型)非摆线线型定-转子共轭副的成形方法,即将一条直线段作为发生线按外滚法包络转子线型,再用转子线型按内滚法包络定子线型。随后从几何方面和运动方面分析了非摆线型单螺杆泵定-转子线型的形成原理,推导出转子的线型(即转子端面曲线)方程。用该转子线型成形方法得到的转子线型可直接作为采油螺杆泵转子轮廓线,无需由骨线向外做等距曲线再得到轮廓线,因此不会出现轮廓线打扣现象。研究成果可为非摆线型单螺杆泵的设计及改进提供参考。

类椭圆型采油螺杆泵过流面积分析

为避免类椭圆型采油螺杆泵转子轮廓出现尖点,首先对类椭圆型螺杆泵的不过切条件进行了分析,给出了螺杆泵合理设计条件,并对螺杆泵的结构参数——偏心距与过流面积的关系进行了分析,得到偏心距是影响过流面积最主要因素的结论。然后通过对定转子线型进行分析得到了理论过流面积计算公式,并得到不同偏心距与过流面积的关系曲线。最后通过关系曲线结合不同偏心距的定转子形状,优选出偏心距的取值范围。

偏心距对类椭圆形采油螺杆泵举升性能的影响

针对不同偏心距螺杆泵,计算分析了排量的变化规律,并利用有限元方法研究分析了偏心距对螺杆泵举升性能的影响,给出了不同条件下螺杆泵扬程与偏心距的定量关系。结果表明:螺杆泵排量随偏心距的增大而减小;螺杆泵接触带上临界接触应力随低压腔室内部压力的增加而减小,但此规律与偏心距的大小无关;随着偏心距的增大,螺杆泵扬程下降。

Study on the Homologous Sequences of copia-like Retrotransposons in a Twin ovary Mutant of Rice

A twin ovary mutant derived from the doubled haploid (DH) progeny of a cross,02428/Gui 630, was presumably related to the transposition of some transposable elements. Up to date, all reported the active transposable elements in rice (Oryza sativa L.) are copia like retrotransposons. In the present study, the reverse transcriptase domains of copia like retrotransposons were amplified from the total DNA isolated from the mutant plants with the degenerated oligonucleotide primers for the domain. Three cloned insert DNAs, R33 1, R33 4 and R33 8, representing putative different copia like retrotransposons were screened out. Two of them displayed high polymorphism between “Zhaiyeqing 8” and “Jingxi 17”. Nine of the polymorphic bands were mapped on seven rice chromosomes. Sequencing analysis revealed that stop codons frequently occur in the sequence of R33 8, while both R33 1 and R33 4 contain a continuous coding region for 81 putative amino acid residues. No significant variation in hybridization patterns was found between indica and japonica rice or among 26 varieties of indica rice when R33 1 was used as a probe. Nevertheless, when R33 4 was used as a probe, high polymorphisms were detected both between indica and japonica rice and among 26 indica varieties, implying that this element might still be active in rice genomes.

Characterization of Energy_Transduction in Thermal Pretreated Chloroplast from Spinach

Characterization of energy-transduction on die chloroplast thylakoid membranes from spinach (Spinacia oleracca L.) after thermal pretreatment was investigated. The related reactions of energy-transduction in chloroplasts were seriously affected by thermal pretreatment. The results were obtained as following: (1) The rate of cyclic photophosphorylation declined when the pretreatment temperature increased in the range of 25 to 45 degreesC. (2) The thermal pretreatment led to a decrease of the activity of thylakoid membrane-bounded ATPase. (3) Proton uptake of chloroplasts acid the fluorescence quenching of 9-aminoacridine (9-AA) in thylakoid membrane decreased after the thermal pretreatment, but addition of dicyclohexylcarbodiimide (DCCD) could partially restore the fluorescence quenching of 9-AA. (4) Both the rates of fast phase in electrochroism absorption change at 515 nm and the millisecond delayed light emission (ms-DLE) of chloroplast showed a progressive decrease upon raising the temperature of pretreatment. (5) Immunbloting analysis showed that the thermal pretreatment caused the changes of protein content and the electrophoresis mobility of thylakoid membrane-bound ATPase and its alpha -subunit. (6) If the temperature of pretreatment were higher than 33 degreesC, oxygen uptake of PS I -mediated in the samples was rapidly inhibited, but addition of sinapine into the reaction medium could partially restore the ability of oxygen uptake in the samples. These results are briefly discussed in relation to the change of permeability of thylakoid membranes, the dissociation of coupling factor complex as well as accumulation of the radicals in the thylakoid membranes after thermal pretreatment.

New Insight into the Development of Oxygen Carrier Materials for Chemical Looping Systems

Chemical looping combustion （CLC） and chemical looping reforming （CLR） are innovative technologies for clean and efficient hydrocarbon conversion into power, fuels, and chemicals through cyclic redox reac- tions. Metal oxide materials play an essential role in the chemical looping redox processes. During reduc- tion, the oxygen carriers donate the required amount of oxygen ions for hydrocarbon conversion and product synthesis. In the oxidation step, the depleted metal oxide oxygen carriers are replenished with molecular oxygen from the air while heat is released. In recent years, there have been significant advances in oxygen carrier materials for various chemical looping applications. Among these metal oxide materials, iron-based oxygen carriers are attractive due to their high oxygen-carrying capacity, cost ben- efits, and versatility in applications for chemical looping reactions. Their reactivity can also be enhanced via structural design and modification. This review discusses recent advances in the development of oxy- gen carrier materials and the mechanisms of hydrocarbon conversion over these materials. These advances will facilitate the development of oxygen carrier materials for more efficient chemical looping technology applications.

Theoretical Study of Reaction Paths and Transition States on Conversion Methane into C_2 Hydrocarbons Through Plasma

The direct synthesis of C2 hydrocarbons （ethylene, acetylene and ethane） from methane is one of the most important task in C1 chemistry. Higher conversion of methane and selectivity to C2 hydrocarbons can be real-ized through plasma reaction. In order to explore the reaction process and mechanism, the possible reaction paths （1）—（4） were proposed on coupling reaction of methane through plasma and studied theoretically using semi-PM3 method [PM3 is parameterization method of modified neglect of diatomic overlap （MNDO）] including determining the transition state, calculating the activation energy and thermodynamic state functions and analyzing the bond or-der and intrinsic reaction coordinate. The reaction heat results indicate that the reactions （2） and （4） are exothermic, while reactions of （1） and （3） are endothermic. The activation energy results show that activation energy for reac-tions （1） and （2） was much lower than that of reaction paths （3） and （4）. Therefore, paths （1） and （2） is the favorable reaction path energetically. More interestingly by comparing the intrinsic reaction coordinated （IRC） of the reaction paths （1） and （2）, it is found that the variations of bond lengths in reaction path （1） has a crucial effect on the poten-tial energy, while in reaction path （2）, the adjustment of the system geometry also contributes to the whole potential energy of the system.

Gauge Transformation and Constraint Induced Operator Ordering for Charged Rigid Planar Rotator in Uniform Magnetic Field

When the motion of a particle is constrained, excess terms exist using hermitian form of Cartesian momentum pi （i=1, 2,3） in usual kinetic energy （1/2/μ）∑ pi^2 , and the correct kinetic energy turns out to be （1/2μ） ∑1/ fipi f ipi, where fi are dummy factors in classical mechanics and nontrivial in quantum mechanics. In this paper the explicit form of the dummy functions fi is given for a charged rigid planar rotator in the uniform magnetic field with different gauge chosen. Under different gauges, we have different sets of dummy factors. It means that these factors do not have direct observable effect.

Tonal Noise Prediction of an Automotive Engine Cooling Fan： Comparison between Analytical Models and Acoustic Analogy Results

Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals with the prediction of tonal noise using analytical models. As for the second part, it describes a hybrid approach for predicting tonal noise where the sources are extracted from an Unsteady Reynolds-Averaged Naviers-Stocks （URANS） simulation and then propagated into the far, free field using the Ffowcs Williams and Hawkings＇ acoustic analogy. The computational domain is meshed with 46 million polyhedral elements and the simulation takes into account the exact geometry of the rotor blades, the stator blades and the shroud. The results from the first part show that analytical models can be used for comparisons between different fan geometries, but are unable to provide accurate noise predictions compared to experimental results. The simulation shows non-periodic blade loading over a whole fan revolution, and different blade loading between the blades. This introduces some bias in the assessment of the acoustic performance of the fan. Overall, the results from the hybrid method are in accordance with the experimental results.

Comparison of two types of twin-rotor piston engine mechanisms

A novel twin-rotor piston engine （TRPE） mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism （DVDM）. Two special geared four-bar mechanisms, DVDM-1 and DVDM-2, were utilized and compared. Based on the closed loop vector method, a mathematical model for position, velocity, and acceleration of the two mechanisms was established. Numerical examples illustrate that the kinematic characteristics were presented. Expression of the displacement and compression ratio of the two engine mechanisms were derived and compared. It is concluded that both DVDM-1 and DVDM-2 adopted in the proposed TRPE with six vane pistons create thirty-six power strokes per revolution of the output shaft, and the summation of two angles covered by each rocker is always 2x/N as the output shaft rotates an angle of x/N. In DVDM-1, the span angle of a vane piston should be designed to be 10.2°, and the compression ratio should be equal to 10; in DVDM-2, the span angle of a vane piston should be designed to be 10.6°, and the compression ratio should be equal to 4.3.

Synthesis of Antimalarial Bicyclic Hemiketal Peroxides Belonging to the G-factor Family

Structural analogues of bicyclic peroxides belonging to the G factors family have been synthesised under Mannieh type conditions, followed by an autoxidation step furnishing exclusively the peroxide. As electron transfer from heine or free iron to peroxide is the first step in the mode of action ofartemisinin -like compound, Fe（fl） induced reduction was studied and the reactivity of the intermediate C-centered radical formed was correlated to the antimalarial activity. Dissociative electron transfer was studied by electrochemistry and allowed the evaluation of the standard reduction potentials and other pertinent thermochemical information. These bicyclic peroxides were evaluated in vitro against Plasmodium falciparum and revealed moderate to good activity.