Five-phase Synchronous Reluctance Machines Equipped with a Novel Type of Fractional Slot Winding

Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill factor.The five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive trucks.But,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core losses.This manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.

Survey on performance of vertical slot and nature-like fishways at Angu hydropower station, Southwest China

To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in China.The Angu hydropower station involved diverse important fish habitats in the lower reaches of the Daduhe River in Southwest China.Therefore,a vertical slot fishway(VSF)and a nature-like fishway(NLF)were built near the backwater area of the reservoir to connect the upstream and downstream habitats.Hydrodynamic and aquatic ecological surveys were conducted after the completion of the project to estimate the fish passing effect of the two fishways.The results indicated that both fishways were in effective operation and could maintain the desired hydrodynamic conditions and be used by several local fish species.During the survey,149 fish from 15 species and 111 fish from 17 species were captured by the traps in the VSF and NLF,respectively,while 1263 fish from 27 species were found in the downstream area.Some species captured in the VSF were not found in the NLF,and vice versa,which implied the different preferences of fish.Meanwhile,3789 signals including 2099 upward ones and 1690 downward ones were monitored with an ultrasonic fish detector at the inlet of the VSF.These findings revealed the characteristics of fish species observed in and near the fishways and provided valuable insights into the different fish passing capabilities of VSFandNLF.

数字大平板SLOT技术在脊柱侧弯上的临床应用

目的探讨数字大平板SLOT技术在脊柱侧弯上的临床应用价值。方法选择52例脊柱侧弯患者,应用数字大平板SLOT技术对脊柱从上至下进行连续曝光,再经过SLOT Radiography软件对采集图像进行处理,得到全脊柱图像,并对图像进行评价。结果 52例脊柱侧弯患者,S形侧弯14例(27%),左侧弯23例(44%),右侧弯15例(29%);其中胸椎侧弯17例,腰椎侧弯21例,合并椎体畸形7例,合并骨盆倾斜改变1例。所有病例都能在一张X线胶片上清晰显示颈、胸、腰、骶尾椎,整个图像无拼接伪影,椎体的清晰度符合标准的脊柱影像要求,并能准确的测量Cobb角。结论数字大平板的SLOT全景技术能有效地去除拼接伪影,使全脊柱能同时在1张X线胶片上完整无缝呈现,全景图像清晰,密度均匀一致,影像质量完全达到了临床对侧弯长度和Cobb角测量的要求,为脊柱侧弯矫形术治疗方案的旋转,术前设计及术后评估提供了可靠的影像学依据。

Slot双下肢全长摄影在全膝关节置换术中的应用价值

目的探讨动态平板透视的狭缝全景摄影技术(Slot)双下肢全长摄影在膝关节置换术的临床应用价值。方法回顾性分析2013年11月-2017年3月89例膝关节置换患者,共99个膝关节进行全膝关节置换术,每位患者在手术前后分别使用动态平板透视摄影系统的狭缝全景技术进行负重位的双下肢全长摄影,采用0~2分的评分方式对图像质量进行评估,0分图像质量差,1分图像质量中等,2分者为图像质量优良,并在图像质量优良的图片上通过后处理软件对患者的手术膝进行术前和术后下肢力线及胫股角进行测量,对术前进行全面评估,同时通过对比分析评价手术效果。结果 (1)89例患者Slot双下肢全长摄像一次成功率100%,成像时间短,操作简便、快捷,每位患者图像质量评分均为2分,质量优良,完全满足诊断及临床的要求;(2)89例患者术前均得到全面准确的评估,80例为骨性关节炎,9例为创伤性骨关节炎,其中,合并膝内翻畸形17例,膝外翻畸形患者8例,无合并内外翻畸形者64例;(3)术后所有患者假体对位、对线良好,假体周围无骨折,所有患者下肢力线和胫股角均为正常范围,17例膝关节内翻畸形患者,胫股角手术前后比较差异有统计学意义(t=-6.590,P=0.000);8例膝外翻畸形患者,胫股角手术前后比较差异有统计学意义(t=5.597,P=0.001),膝内外翻畸形较术前均得到良好的校正;无合并内外翻畸形64例患者术后下肢力线与重力垂线夹角和胫股角与手术前后比较,差异无统计学意义(t_(前者)=0.725,P=0.487,t_(后者)=-2.090,P=0.070)。结论使用狭缝全景摄影技术对双下肢全长进行成像,其成功率高、检查时间短、辐射剂量低,且图像拼接操作简便,质量优良,满足临床诊断需求,对临床术前手术方案制定及术后评估具有重要应用价值。

slot波导包覆层对功率密度的影响

理论模拟研究了硅基绝缘(SOI)的slot波导中槽内限制功率与slot波导的结构参数以及包覆层折射率的关系。结果表明,如果包覆层的折射率偏离衬底SiO2的折射率,相同参数下的slot波导的传输损耗大于包覆层为SiO2的结构的传输损耗。分析表明,如果包层与衬底折射率不同,限制的光功率会从slot缝隙中渗透到折射率较高的衬底或者包层中,从而引起能量的损耗。理论模拟得到了在缝隙宽度为0.12μm的情况下,slot波导槽内最大的光功率限制为28.54%,这个值包含了纳米线波导与slot波导直接耦合产生的耦合损耗以及slot波导自身的传输损耗。

Full Wave Analysis of a Broad Wall Waveguide Slot Coupler

A rigorous analysis of a broad wall slot coupler composed of two crossed rectangular waveguides by using FDTD method is presented. Two types of slots, a longitudinal/transverse slot and a centered-inclined slot, are analyzed. Coupling slot characteristics are obtained, including scattering parameters and the resonant length for different waveguide dimensions and frequencies. The numerical results are all in good agreement with those by the method of moments. A coupler system with a short circuit port is also analyzed to help designing the slot array.

具有多重码的预约Slotted ALOHA协议性能分析

本文对具有多重码的预约Ｓｌｏｔｔｅｄ ＡＬＯＨＡ协议进行了性能分析。它是基于帧的协议且在一个时隙内有多重码可用来传输分组信息。文中利用离散时间、离散状态的Ｍａｒｋｏｖ链来分析一个小区上行链路的话音分组吞吐量和数据分组延时性能，并提出了两种改进碰撞解决的方法，得到了较好的系统特性。

Modified Reynolds Equation for Squeeze-Film Air Damping of Slotted Plates in MEMS Devices

A differential equation for calculating squeeze-film air damping in slotted plates is developed by modifying the Reynolds equation. A term is added to account for the effect of airflow through the slots on the air damping of the plate. The end effect of the airflow in the slots is also treated by substituting an effective channel length for the geometric channel length （i. e. the thickness of the plate）..The damping pressure distribution, damping force, and damping force coefficient of the slotted plates can be found by solving the equation under appropriate boundary conditions. With restrictions on the thickness and the lateral dimensions of the slotted plate removed,the equation provides a useful tool for analysing the squeeze-film air damping effect of slotted plates with finite thickness and finite lateral dimensions. For a typical slotted plate structure, the damping force coefficient obtained by this equation agrees well with that generated by ANSYS.

HFC上行信道多重码预约Slotted ALOHA随机多址接入的性能分析

1 引言 光纤同轴电缆混合(hybrid fiber/coax,HFC)网络具有光纤的高带宽和同轴电缆的共享性,是较为经济可行的宽带用户接入方案之一.HFC能提供话音、数据、视频等业务的综合接入,为宽带信号进入家庭铺平了'最后一公里'.

基于slot波导的硅基长波红外偏振无关定向耦合器分析

硅基长波红外集成光电子器件是集成光学发展的一个新兴领域.阐述了利用等比例放大原理设计该波段下的slot波导的思路,分析了波导的限制因子、偏振特性等性质,并提出了工作波长为10.6μm的偏振无关slot波导定向耦合器.

Shielding Effectiveness of Rural Concealed Communication Cable of Asymmetric/Symmetric Slots with Different Shapes

With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.

用质量控制狭缝式杂交法（Coslot）检测妇女宫颈上皮中人乳头瘤病毒（HPV）DNA

本文报道一种能对ＨＰＶ进行较为准确分型的刚Ａ杂交程序和方法。它具有如下特点：１．由于简化了实验程序，标本消耗减少。因此该方法尤其适用于小组织活检标本（１－２ｍｇ）中ＤＮＡ同源序列检测；２．敏感性高。由于标本消耗减少，使ＨＰＶ检出率大为提高，与斑点杂交技术相比，敏感性提高１．６倍；３．型别特异性强。由于改变了实验条件及在实验过程中实行严格的质量控制，明显减少了不同ＨＰＶ型别的交叉反应，甚至在部分出现交叉反应的标本中，仍可通过强度对比来最后判定ＨＰＶ感染型别。应用该技术对１４３份宫颈炎标本、１７份宫颈不典型增生标本及２５份宫颈癌标本进行了ＨＰＶ１６型检测，阳性率分别为５０．０５％（７３／１４３）、５７％（２７／４７）及７６％（１９／２５），并与Ｄｏｔｂｌｏｔ方法进行了比较。该方法在ＨＰＶ感染与宫颈癌关系的分子流行病学研究中具有重要意义和广阔的应用前景。

一种基于动态slot分配的公平调度算法

Hadoop框架中基于缺额的公平调度算法以统一的固定配置设置定时计算和更新作业信息,在一定程度上影响了其作业调度的公平性,同时也不能满足作业的资源需求。针对基于缺额的公平调度算法配置方式的不足,提出一种基于公平性的动态slot分配算法,通过实时计算更新缺额进行slot分配以确保真正的公平性。

基于Photonic Slot Routing的波分复用网络的协议与结构

本文介绍了波分复用技术与全光网络的概念,提出了基于光槽路由的波分复用网络体系结构,讨论了实现光槽与分组传送的方法以及有关的网络存取协议,并给出了全光学网络中网桥与节点的示意性结构。本文的目的是提供一个这种方法的基本描述。

Induced drill-spray during hydraulic slotting of a coal seam and its influence on gas extraction

Hydraulic slotting can induce drill spray in a gassy,low permeability coal seam.This then influences subsequent gas extraction.This paper describes the drill spray phenomenon from a mechanical perspective and analyzes the effects of water jet damage during slotting.A simulation of the stresses around the drill hole and slot was prepared using FLAC-3D code.It helps explain the induction of drill spray during hydraulic slotting.The stress concentration around the bore increases as the diameter of the hole increases.As the hole enlarges the variation in stress also increases,which introduces an instability into the coal.This allows easy breaking and removal of the coal.Destruction of the coal structure by the water jet is the major factor causing drill spray.Energy stored as either strain or gas pressure is released by the water jet and this causes the coal to fracture and be expelled from the hole.Field tests showed the effect on gas extraction after slotting with drill spray.The concentration of gas increases after drilling.Compared to conventional techniques,the hydraulic slotted bore gives a gas concentration three times higher and has an effective range twice as far.This makes the gas extraction process more efficient and allows reduced construction effort.

Progress on the hydraulic measures for grid slotting and fracking to enhance coal seam permeability

A method of hydraulic grid slotting and hydraulic fracturing was proposed to enhance the permeability of low permeability coal seam in China. Micro-structural development and strength characteristics of coal were analysed to set up the failure criterion of coal containing water and gas, which could describe the destruction rule of coal containing gas under the hydraulic measures more accurately. Based on the theory of transient flow and fluid grid, the numerical calculation model of turbulence formed by high pressure oscillating water jet was used. With the high speed photography test, dynamic evolution and pulsation characteristics of water jet water analysed which laid a foundation for mechanism analysis of rock damage under water jet. Wave equation of oscillating water jet slotting was established and the mechanism of coal damage by the impact stress wave under oscillation jet was revealed. These provide a new method to study the mechanism of porosity and crack damage under high pressure jet.Fracture criterion by jet slotting was established and mechanism of crack development controlled by crack zone between slots was found. The fractures were induced to extend along pre-set direction,instead of being controlled by original stress field. The model of gas migration through coal seams after the hydraulic measures for grid slotting and fracking was established. The key technology and equipment for grid slotting and fracking with high-pressure oscillating jet were developed and applied to coal mines in Chongqing and Henan in China. The results show that the gas permeability of coal seam is enhanced by three orders of magnitude, efficiency of roadway excavation and mining is improved by more than 57%and the cost of gas control is reduced by 50%.

Fluid-based Slotting Optimization for Automated Order Picking System with Multiple Dispenser Types

Slotting strategy heavily influences the throughput and operational cost of automated order picking system with multiple dispenser types, which is called the complex automated order picking system （CAOPS）. Existing research either focuses on one aspect of the slotting optimization problem or only considers one part of CAOPS, such as the Low-volume Dispensers, to develop corresponding slotting strategies. In order to provide a comprehensive and systemic approach, a fluid-based slotting strategy is proposed in this paper. The configuration of CAOPS is presented with specific reference to its fast-picking and restocking subsystems. Based on extended fluid model, a nonlinear mathematical programming model is developed to determine the optimal volume allotted to each stock keeping unit （SKU） in a certain mode by minimize the restocking cost of that mode. Conclusion from the allocation model is specified for the storage modules of high-volume dispensers and low-volume dispensers. Optimal allocation of storage resources in the fast-picking area of CAOPS is then discussed with the aim of identifying the optimal space of each picking mode. The SKU assignment problem referring to the total restocking cost of CAOPS is analyzed and a greedy heuristic with low time complexity is developed according to the characteristics of CAOPS. Real life application from the tobacco industry is presented in order to exemplify the proposed slotting strategy and assess the effectiveness of the developed methodology. Entry-item-quantity （EIQ） based experiential solutions and proposed-model-based near-optimal solutions are compared. The comparison results show that the proposed strategy generates a savings of over 18% referring to the total restocking cost over one-year period. The strategy proposed in this paper, which can handle the multiple dispenser types, provides a practical quantitative slotting method for CAOPS and can help picking-system-designers make slotting decisions efficiently and effectively.

Experimental Investigation of a Fixed-geometry Two-dimensional Mixed-compression Supersonic Inlet with Sweep-forward High- light and Bleed Slot in an Inverted ＂X＂-type Layout

A fixed-geometry two-dimensional mixed-compression supersonic inlet with sweep-forward high-light and bleed slot in an inverted ＂X＂-form layout was tested in a wind tunnel. Results indicate： （1） with increases of the free stream Mach number, the total pressure recovery decreases, while the mass flow ratio increases to the maximum at the design point and then decreases; （2） when the angle of attack, a, is less than 6°, the total pressure recovery of both side inlets tends to decrease, but, on the lee side inlet, its values are higher than those on the windward side inlet, and the mass flow ratio on lee side inlet increases first and then falls, while on the windward side it keeps declining slowly with the sum of mass flow on both sides remaining almost constant; （3） with the attack angle, a, rising from 6° to 9°, both total pressure recovery and mass flow ratio on the lee side inlet fall quickly, but on the windward side inlet can be observed decreases in the total pressure recovery and increases in the mass flow ratio; （4） by comparing the velocity and back pressure characterristics of the inlet with a bleed slot to those of the inlet without, it stands to reason that the existence of a bleed slot has not only widened the steady working range of inlet, but also made an enormous improvement in its performance at high Mach numbers. Besides, this paper also presents an example to show how this type of inlet is designed.

Hydrodynamic Characteristics of Three Rows of Vertical Slotted Wall Breakwaters

In this study, we examine the hydrodynamic characteristics of three rows of vertical slotted wall breakwaters in which the front and middle walls are permeable and partially immersed in a water channel of constant depth, whereas the third wall is impermeable. The wave–structure interaction and flow behavior of this type of breakwater arrangement are complicated and must be analyzed before breakwaters can be appropriately designed. To study the hydrodynamic breakwater performance, we developed a mathematical model based on the eigenfunction expansion method and a least squares technique for predicting wave interaction with three rows of vertical slotted wall breakwaters. We theoretically examined the wave transmission, reflection, energy loss, wave runup, and wave force under normal regular waves. Comparisons with experimental measurements show that the mathematical model results adequately reproduce most of the important features. The results of this investigation provide a better understanding of the hydrodynamic performance of triple-row vertical slotted wall breakwaters.

Theory and Experimental Verification on Cymbal-shaped Slotted Valve Piezoelectric Pump

Valve piezoelectric pumps usually have larger flow rate than that of valveless ones. However, the traditional cantilever valve easily induces stress concentration which impacts the reliability of pumps. Therefore, a cymbal-shaped slotted check valve is proposed to be applied in a piezoelectric pump in order to reduce the stress concentration of the valve and thus improve the reliability of the piezoelectric pump. The structure and working principle of the piezoelectric pump are analyzed; the stress analysis of the cymbal-shaped slotted valve diaphragm is conducted. In addition, finite element software is employed to analyze the difference of the Von-Mises stress between the cymbal-shaped slotted diaphragm and the slotted flat diaphragm. The simulation results show that, the Von-Mises stress of cymbal-shaped slotted diaphragm is smaller than that of the slotted flat one. Furthermore, the cymbal-shaped slotted valve piezoelectric pump is also fabricated, and flow rate experiment is performed. The experimental results indicate that the flow rate of piezoelectric pump working in low frequencies(0 Hz < f< 50 Hz) is larger than that working in high frequencies(200 Hz < f< 2000 Hz). When driven at voltage of 160 V and frequency of 5 Hz, the pump reaches its maximum flow rate of 6.6 g/min. The experimental results validate the feasibility of the cymbal-shaped slotted check valve. This research can effectively solve the problem of stress concentration of valve piezoelectric pumps and is helpful for improving the reliability of them.