摘要：在简要分析开发软磁铁粉材料 (SMC)永磁电动机前景的基础上 ,设计并制造了一台以SMC材料为定子铁心的爪极永磁同步电动机 ,建立了电机的等值磁路图并进行了磁场分析 .采用三维有限元数值方法进行了磁场计算 ,计算结果得到样机试验结果的验证 .

摘要：A detailed design methodology of a micro-scale 2-DOF energy harvesting device that can harvest human motion energy of low frequency and wide bandwidth is developed. Based on the concept of the 2-DOF vibration absorber, device parameters are selected to harvest energy at low frequency of 1-10 Hz and wide bandwidth with ±20% of the mean frequency, which matches the human motion. The device dimensions are limited to 40 × 30 × 10 mm3 to fit with the human wrist size. Then, a finite element model is developed to investigate the system performance with the selected parameters. When subjected to harmonic excitation of 1 g, the proposed 2-DOF device is able to provide a power of at least 10 μW in between the two close resonant peaks of 4 Hz and 6 Hz, which is the target frequency range. The device shows very high power per square frequency compared with the reported harvesters.

摘要：Based on the D-H notation, kinematics model and inverse kinematics model of 6R industrial robots are established. Using graphical method, the boundary curve equations of the 6R industrial robot workspace are obtained. Based on the prescribed workspace, the D-H parameter optimization method of 6R industrial robots is proposed. Using the genetic algorithm to determine the structural dimensions of a 6R robot, we make sure that its workspace can exactly contain the prescribed workspace. This method can be used to reduce the overall size of the robot, save materials and reduce the power consumption of the robot during its work time.

摘要：岩爆预测对地下硬岩矿山的设计和施工至关重要。使用三种基于树的集成方法,对由102个历史案例(即1998—2011年期间14个硬岩矿山数据)组成的岩爆数据库进行了检查,以用于有岩爆倾向矿井的岩爆预测。该岩爆数据集包含六个广泛接受的倾向性指标,即:开挖边界周围的最大切向应力(MTS)、完整岩石的单轴抗压强度(UCS)和单轴抗拉强度(UTS)、应力集中系数(SCF)、岩石脆性指数(BI)和应变能储存指数(EEI)。以分类树作为基准分类器的两种Boosting算法(AdaBoost.M1,SAMME)和Bagging算法进行了评估,评估了它们学习岩爆的能力。将可用数据集随机分为训练集(整个数据集的2/3)和测试集(其余数据集)。采用重复10倍交叉验证(CV)作为调整模型超参数的验证方法,并利用边际分析和变量相对重要性分析了各集成学习模型特征。根据重复10倍交叉验证结果,对岩爆数据集的精度分析表明,与AdaBoost.M1、SAMME算法和岩爆经验判据相比,Bagging方法是预测硬岩矿山岩爆的最佳方法。

摘要：分析正螺旋面的空间尺寸特点,将计算下料方法和三角线法相结合,计算组成螺旋叶片的各个空间四边形单元的展开尺寸,将四边形单元的展开图依次拼接即可得到螺旋叶片的展开图。用VisualC++编程,能够快速、较精确地展开各种规格的正螺旋面(包括圆台形螺旋),绘制近似展开图。同时得到DXF文件,供AutoCAD直接调用以便输出下料图。最后给出了设计实例。

摘要：高效圆偏振发光材料在传感、光学器件、不对称合成等领域有着广泛的应用,设计和制备圆偏振发光材料引起了人们的广泛关注.然而,构筑具有高发光不对称因子的圆偏振发光材料仍然是一个挑战.这里,我们制备了一种手性超分子组装金属大环,该超分子组装金属大环可以通过分子间铂···铂相互作用诱导逐级自组装促进圆偏振光的放大.值得注意的是,超分子组装金属大环显示出高的发光不对称因子以及较强的圆偏振光信号,而其对应的组装配体没有显示出圆偏振光信号.通过紫外-可见吸收光谱和发射光谱、核磁共振氢谱、扫描电镜、透射电镜、原子力显微镜、粗粒化分子动力学模拟和含时密度泛函理论计算等手段对圆偏振光放大的机理进行了研究.该研究展示了第一例基于铂···铂相互作用驱动的逐级自组装策略制备的高效圆偏振发光材料.

摘要：The provision of fresh water is becoming an increasingly important issue in many areas of the world. Clean water is a basic human necessity, and without water life will be impossible. The rapid international developments, the industrial growth, agriculture and population explosion all over the world have resulted in a large escalation of demand for fresh water. The solar still is the most economical way to accomplish this objective. The sun’s energy heats water to the point of evaporation. When water evaporates, water vapour rises leaving the impurities like salts, heavy metals and condensate on the underside of the glass cover. Solar distillation has low yield, but safe and pure supplies of water in remote areas. The attempts are made to increase the productivity of solar still by using nanofluids and also by black paint coat- ing inside the still basin. Heat transfer enhancement in solar still is one of the key issues of energy saving and compact designs. The essential initiative is to seek the solid particles having thermal conductivity of several hundred times higher than those of conventional fluids. Recently, as an innovative material, nanosized particles have been used in sus- pension in conventional solar still water. The fluids with nanosized solid particles suspended in them are called “nanofluids”. The suspended metallic or nonmetallic nanoparticles change the transport properties, heat transfer characteristics and evaporative properties of the base fluid, The aim of this paper is to analyze and compare the enhanced performance of a single basin solar still using nanofluids with the conventional water. They greatly improve the rate of evaporation and hence the increase in efficiency.

摘要：Wise arrangement of antennas is critical in wireless cellular systems for both reductions of co-channel interference (CCI) and increase the quality of service (QoS). In this paper, a novel architecture for antenna arrangement in CDMA wireless cellular systems is presented. In this architecture that we called Microzone, every cell is divided into three (or more) zones and information transmission in downlink channel is done by an antenna which is placed at the outer region of the related zone. Also, the transmitting signal by the mobile station (MS) in uplink channel is received by all the antennas of the related cell. Analytical calculations of the received signal to noise ratio (SIR) and outage probability for both microzone and used architectures show that proposed architecture has better performance in compared with the used architecture. Also, simulation results confirm lower outage probability in uplink channel for microzone architecture.

摘要：研究在日本传统"诗吟"表演中,在干信号中加上适当时延的单个反射声是否更为有利.专业"诗吟"表演者嗓音中对典型的"节"的吟唱是该种表演艺术的一种独特的吟咏方式.对此及对"节"外内容的吟唱都在消音室中加以录音.文中通过成对比较法试验得出了主观优选的标度值.结果表明,在聆听对"节"的吟唱时,听者更喜欢在干信号中加上延时为10～30ms的单个反射声,而在聆听对"节"外内容的吟唱时,加上单个反射声与否对听者而言并无显著的差别.文中对此项发现从吟唱"节"的声源信号的自相关函数的包络特征上加以讨论.