连铸喷嘴特性测试与分析

通过测试连铸二冷喷嘴性能，对比同型号喷嘴使用前后两种状态下特性参数，分析了喷嘴参数变化的原因。提出了对使用中的喷嘴特性进行检测与校核的建议，以确保喷嘴特性满足铸坯二冷工艺条件，保证铸坯质量。     

钢液二次精炼用CaO基熔剂的脱磷能力

根据CaO基熔渣和钢液之间在1853K脱磷平衡实验结果，利用CaO-Fe2O3-CaF2和CaO-BaO-Fe2O3-CaF2熔剂对钢液进行二次精炼脱磷试验，试验发现，采用优化组成的CaO基熔剂，可得到大于90%的脱磷率，能将钢液磷含量从0.05%降低到0.005%以下。     

MnCl2对镁合金废旧料组织性能的影响

利用等离子发射光谱仪、金相分析、电镜、万能电子材料试验机、腐蚀试验等方法研究了含有不同量的MnCl2熔剂对镁合金废旧料的力学性能、组织、断口形貌以及腐蚀行为的影响。研究表明,MnCl2可以降低镁合金废旧料中的Fe含量,同时会增加镁合金的Mn量,使用含MnCl2的熔剂可将镁废旧料中的Fe含量降到0 0072%以下。采用含MnCl2的熔剂可以提高试样的σb和δ。当合金中的Mn量超过一定程度后,对镁合金的力学性能会产生不利的影响。金相观察表明,净化处理对断口形貌无明显的影响,不改变AZ91镁合金的断裂机理,断口均成准解理断裂。腐蚀试验表明,采用含30%MnCl2的熔剂可以使试样的腐蚀速率从20 9mg/(cm2·d)降到6 4mg/(cm2·d)。     

多矿物粘土基陶瓷地砖

以易熔粘土为基，并引入难熔粘土和熔剂成分，合成了地砖坯料。经研究确定，只要遵循一定的条件，是可以用上述原料生产出优质产品的。指出了制品结构和相组成的形成特点。     

Application of combined coagulation-ultrafiltration membrane process for water treatment

The objectives of this research are to identify the membrane fouling potential due to different fractions of NOM and correlate the physicochemical properties of NOM and membranes with the adsorption of humic substances on membrane and investigate the mechanism of coagulation affecting UF, and find the optimum conditions of the combined of coagulation with UF membrane filtration for NOM removal. For Nakdong river water, the humic acid fraction was the most reactive precursor fraction for the formation of the ratio of THMFP/DOC (STHMFP) and TOXFP/DOC (STOXFP). The result of adsorption kinetics tests showed that hydrophobic organics adsorbed much more quickly than hydrophilic organics on both membranes. Thus, hydrophobic compounds exhibited a preferential adsorption onto membrane. In case of the effect of membrane properties on the adsorption of organic fractions, the adsorption ratio (C₁/C_e) was greater for the hydrophobic membrane than for the hydrophilic membrane regardless of the kind of organic fractions. For combined coagulation with membrane process, flux reduction rate showed lower than the UF process alone. Also, the rate of flux decline for the hydrophobic membrane was considerably greater than for the hydrophilic membrane. Applying the coagulation process before membrane filtration showed not only reduced membrane fouling, but also improved removal of dissolved organic materials that might otherwise not be removed by the membrane. That is, during the mixing period, substantial changes in particle size distribution occurred under rapid and slow mixing conditions due to the simultaneous formation of microflocs and NOM precipitates. Therefore, combined pretreatment using coagulation (both rapid mixing and slow mixing) improved not only dissolved organic removal efficiency but also DBP (Disinfection By-Product) precursor's removal efficiency.     

Ultrasonic defouling of reverse osmosis membranes used to treat wastewater effluents

On-line ultrasonic cleaning was used to remove fouling from a commercially important polyamide based reverse osmosis membrane during cross-flow filtration of CaSO₄, Fe³⁺ and carboxyl cellulose solutions. In each case, the permeate flux of the membrane increased significantly, with virtually no decrease in rejection in the presence of ultrasonication. Membrane surface characterization via scanning electron microscopy (SEM) confirmed the beneficial effect of ultrasonication on the membrane permeate flux. These studies suggest that ultrasonic defouling may be a very useful approach for the future development of reverse membranes, especially as far as fouling with organic materials is concerned.     

熔盐堆临界能谱与通量分布的仿真计算

研究熔盐反应堆在临界工况下的堆芯中子能量和中子通量分布.由于熔盐反应堆的几何结构与目前的热中子反应堆存在很大差异,导致热中子反应堆能谱的求解方法在对熔盐堆进行计算时存在几何处理上的困难.针对上述问题,提出采用具有任意几何处理能力的中子输运计算软件MCNP对熔盐堆堆芯结构进行建模,采用能量区间上的平均通量代替该区间内通量分布的方法,计算了两种熔盐堆在临界工况下的堆芯中子能谱.结果表明,MSBR堆芯能谱为典型的热堆能谱;MO-SART堆芯能谱介于快堆能谱和热堆能谱之间.结果能够作为堆芯扩散计算中能量分群方法的依据.同时分析了堆芯内中子通量分布情况,结果表明熔盐堆中子通量分布具有中间高、四周低的特点.     

Suspension force control of bearingless permanent magnet slice motor based on flux linkage identification

The control accuracy and dynamic performance of suspension force are confined in the traditional bearingless permanent magnet slice motor (BPMSM) control strategies because the suspension force control is indirectly achieved by adopting a closed loop of displacement only. Besides, the phase information in suspension force control relies on accurate measurement of rotor position, making the control system more complex. In this paper, a new suspension force control strategy with displacement and radial suspension force double closed loops is proposed, the flux linkage of motor windings is identified based on voltage–current model and the flexibility of motor control can be improved greatly. Simulation and experimental results show that the proposed suspension force control strategy is effective to realize the stable operation of the BPMSM.     

磁通切换型永磁电机转矩脉动抑制

磁通切换型永磁电机（简称磁通切换电机）是定子励磁型电机的一种,由于它在定子和转子上都开槽,因此,加载运行时尤其在低速时具有较大的转矩脉动和振动噪声。在这类电机中,由于交直轴电感几乎相等,因此其磁阻转矩平均值几乎为零,但是,会引起一定的转矩脉动。该文运用冻结磁导率方法,研究了磁通切换电机的磁阻转矩及其引起的转矩脉动产生机理;同时,该文也研究了磁阻转矩随电枢电流和定子绕组结构的变化规律。研究结果显示:在采用id=0控制时,磁阻转矩对输出转矩没有贡献,其平均值几乎为零,只会导致转矩脉动。此外,该文也分析了定、转子分别削角对磁阻转矩的影响规律。研究结果显示,采用转子直角削角和定子圆角削角相结合的方式可以使转矩脉动由25.3%降低到5.3%。     

钢管端部横向裂纹的漏磁检测方法

针对目前钢管自动检测过程中普遍存在的检测盲区问题,提出采用管内部磁化器固定,管外部扫描的漏磁检测新方法。介绍了无盲区检测钢管端部横向裂纹的原理,并从磁化器到检测探头的设计等多方面介绍了整个检测装置的结构,通过大量的实验分析验证了该检测方法的适用性与可靠性。