mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
吉林省非金属矿产资源开发决策中的几个问题

从决策支持的角度探讨了吉林省非金属矿产资源开发决策中的几个问题,其中包括系统现存问题的诊断、重点开发矿种、重点开发地区的确定、主要矿种开发方案(开采、加工关系的处理)的模拟和选择等.认为吉林省非金属矿产资源开发应采取开采—加工混合型即协调型开发方案,充分利用现有资源,注意开展深精加工和综合利用,大力引进资金、技术和人才,不断提高经济效益.
质量预测控制与诊断灰色系统方法

将灰色系统理论中的预测与关联度理论引入产品质量控制领域, 建立了产品合格率产品质量突变区间的GM预测模型以及产品质量影响因素的关联度诊断分析模型, 提出了GMPtC图, 并给出了一个应用案例, 为产品质量的预报控制与因素诊断提供了有效分析方法与工具.
灰色指数曲线曲率拟合方式

定义了点的曲率, 从曲率的角度出发, 给出了任何离散点列与指数曲线拟合的方法, 从而省略了灰色系统理论中通过建模求拟合曲线的步骤, 为实际应用提供了方便.
基于遗传算法和最速下降法的函数优化混合数值算法

在遗传算法中嵌入一个最速下降算子, 并定义适当的适应度函数和子代个体的选择算子, 从而可结合遗传算法和最速下降法两者的长处, 得到既有较快收敛性, 又能以较大概率得到全局极值的新的用于连续函数全局优化的混合数值算法. 数值计算结果表明了本文方法显著优于求解函数优化的遗传算法和最速下降法.
区间数的综合决策模型

提出一种区间数的综合决策模型. 该模型利用集值统计的方法, 对评判矩阵和诸因素的权重分配均用正有界闭区间数表示, 并且给出了一种区间数的排序方法和决策准则以及一个应用实例.
非化学计量比贮氢电极合金的电化学性能和结构及热力学研究

在分别优化稀土A组元和过渡族B组元基础上,研究了AB_γ合金中化学计量比γ值对其电化学性能的影响。结果表明,超化学计量比(γ=5.3)的合金具有较高的放电容量(295mA·h/g)和较小的循环容量衰退(电化学容量在250次循环后为83.6%),但其大电流放电能力有所降低。经XRD分析,γ=5.3的合金具有最大的晶胞体积。从放电容量和循环寿命来看,超化学计量比合金优于化学计量比合金和欠化学计量比合金,但其高倍率放电能力有所降低。用Sievert固-气吸放氢(p-C-T)法求得吸放氢反应的ΔH和ΔS表明,超化学计量比合金AB_(5.3)的生成热较负,形成的氢化物比较稳定,氢原子扩散困难,且使氢原子发生电化学电化学氧化反应阻力增大,因而使电极合金的大电流放电能力降低。
海仙花开花和衰老过程与膜脂过氧化

海仙花从大蕾发育至玫红花时, 开花时间较长, 此后即迅速衰老萎蔫。开花和衰老过程中呼吸速率出现两次高峰, 花盛开为乳白花时出现第1个呼吸峰, 玫红花时又出现一次较低的呼吸峰。从大蕾发育至粉红花时, SOD和DAT活性逐渐增高, Vit. C含量逐渐降低但保持较高水平, 而O~(.)_(2)含量低且变化不大; 粉红花后, SOD和CAT活性继续升高, Vit. C含量迅速降低, O~(.)_(2)含量较快升高; 玫红花后, SOD活性迅速降低, Vit.C含量达最低, O~(.)_(2)含量则迅速升高。开花前期花内MDA含量低且变化不大, 相对透性值缓慢升高, 粉红花后, O~(.(_(2)引发膜脂过氧化加强致使MDA含量和相对透性迅速升高, 花萎蔫时达最高。
缙云山森林次生演替序列优势种群的生态位

通过1986和1996对缙云山森林次生演替序列中四种群落类型的重复调查, 用两种公式计测生态位宽度, 研究演替序列优势种群的基础生态位和实际生态位。结果表明, 实际生态位侧重于物种对特定资源的利用能力, 基础生态位侧重于物种的生态幅度。在缙云山森林次生演替序列中, 各个优势种群的生态位宽度不同, 森林先锋种的最宽实际生态位比演替顶极种窄, 基础生态位则相反。
冷凝气体对蒸发制备铁二元合金超细微粒组份的影响

在133.32Pa压强的Ar,N_2两种不同气体中制备了以Fe_(90)B_(10)为母材的超细微粒。两种微粒的粒径、形态基本一致，但晶化程度及磁性很不一样。通过化学滴定法对两种微粒进行的Fe含量分析表明二者差别很大。在两种冷凝气体中制取的微粒的组份差别可能是因为不同气体对熔体的活度系数影响不同所致。
缙云山退化生态系统不同恢复阶段群落小气候的演替变化

通过5年的群落野外调查,研究分析了重庆缙云山退化生态系统5个不同恢复演替阶段群落小气候演替变化规律。在外部气候条件一致情况下,群落演替是群落内发光强度、气温、极温、湿度变化的主导因素。
濒危植物缙云卫矛的同工酶变异及生态遗传分化

运用电泳技术,测定了重庆北碚特产的缙云卫矛(Euonymus chloranthoides)3个居群36个个体功能叶片的过氧化物酶(Peroxidase, POD),酸性磷酸酯酶(Acidphosphoesterase, ACP)的同工酶谱带,并进行编码;然后采用Rogers-Tanimoto结合系数的组平均法(UPGMA)对各酶谱带进行聚类分析;同时结合遗传杂合度(He)、遗传相似性系数(I)、遗传距离(D)进行分析。结果表明,来自同一居群的个体,不但同工酶谱相似性高、遗传杂合度小,而且遗传相似性系数大、遗传距离小,显示出居群内个体遗传分化小;显示出居群之间的个体却刚好相反。这是由于其特殊的生殖方式和环境隔离所致。
底泥汞含量对鱼类红细胞微核影响研究

研究了底泥HgCl_(2)累积量对鲤、鲫鱼红细胞微核率的影响。结果表明, 水体底泥汞污染可引起鱼类血液红细胞微核率的上升, 并呈现出较明显的剂量和时间效应。其回归方程分别为: 鲤鱼y_(1)=3.7938+1.3236lnx(r=0.9710); 鲫鱼, y_(2)=4.4448+1.487lnx(r=0.9874)。
积极拥抱5G时代,助力急诊学科发展

自从20世纪80年代初我国急诊医学开创以来,在广大急诊专家与同仁们的共同努力之下,目前已经进入快速发展和提高的阶段,为国家社会经济发展和人民群众的健康保障做出了不可替代的巨大贡献。随着当前我国人口继续缓慢增长和社会的老龄化进程加速,人群的疾病谱发生改变,社会活动日益增加,人为和自然灾害事件增多,慢性病急性加重和急性疾病发生的机会增高,加上国家在医疗保障上投入的不断增加,人民群众对急诊医疗服务需求的数量和质量持续增加。因此,当前我国急诊医学的发展迎来了前所未有的大好机遇,也促使全国急诊同仁们积极思考如何加快学科的发展。善于借助各种先进的技术,是发展急诊学科的有效途径之一。本文主要讨论当前5G技术与急诊学科发展的话题。
《中国大动脉炎性肾动脉炎诊治多学科专家共识》的解读

大动脉炎(Takayasu arteritis)是一种慢性、非特异性、肉芽肿性血管炎,主要累及主动脉弓及其主要分支,也可累及胸腹主动脉、肺动脉及其分支、颅内及眼底血管等。血管壁全层炎症导致管腔狭窄和(或)闭塞,少数也可呈管腔扩张或动脉瘤样改变,导致脏器缺血、梗死及功能衰竭。大动脉炎为少见病,好发于40岁以下亚洲女性,亚洲年发病率约1~2/100万人、日本基于医院数据估测年患病率为(12.9~40)/ 100万人,目前中国缺乏具体流行病学数据。根据1996年日本制定的大动脉炎血管分型标准,中国大动脉炎患者V型(30.4%~60.8%)最常见,其次为I型(20.4%~40.0%)、Ⅳ型(6.3%~20.8%)、Ⅱ型(6.4%~8.6%,Ⅱa 3.9%~4.8%、Ⅱb 1.6%~ 3.9%)与Ⅲ型(2.4%~3.9%)。
放大内镜窄带光成像联合内镜超声对早期食管癌浸润深度诊断的准确性分析

目的评估放大内镜窄带光成像(ME-NBI)、内镜超声检查术(EUS)及两者联合对早期食管癌浸润深度判断的准确性。方法选取2015年1月至2017年12月厦门大学附属第一医院行普通白光胃镜检査且病理诊断为早期食管癌的105例患者(105处病灶),通过ME-NBI和EUS评估病灶浸润深度,依据检查结果确定手术方式。以术后病理结果为金标准,分析ME-NBI、EUS及两者联合判断病变浸润深度的准确性。结果ME-NBI判断病变浸润至黏膜上皮层/固有层和≥黏膜肌层的准确率分别为87.3%(69/79)和84.6%(22/26),总体准确率86.7%(91/105),灵敏度和特异度分别为94.5%(69/73)和68.8%(22/32).EUS判断同样浸润深度的准确率分别为85.9%(67/78)和77.8%(21/27),总体准确率83.8 %(88/105),灵敏度和特异度分别为91.8 %(67/73)和65.6 %(21/32).EUS和ME-NBI二者皆提示病变浸润深度不超过黏膜固有层的准确率为91.7%(67/73),而两种方法任一方法判断浸润深度≥黏膜肌层时,只有18.2%(6/33)的病变位于黏膜上皮层/固有层(Kappa = 0.978,P=0.000).结论ME-NBI、EUS对于早期食管癌浸润深度都具有较好的诊断准确性,而联合使用可进一步提高准确性,为治疗方案的选择提供较为可靠的依据。
Optimizing Building Envelope Dimensions for Passive Solar Houses in the Qinghai-Tibetan Region: Window to Wall Ratio and Depth of Sunspace

It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, the establishment of passive solar houses should be an effective strategy to deal with the problem of thermal comfort. Both window to wall ratio(WWR) and sunspace depth are of vital importance to determine the thermal comfort level of passive solar houses, while there are limited studies on analyzing their impacts on passive solar houses in high-altitude regions. Therefore, this study is designed to examine how WWR and sunspace depth affect space heating of passive solar houses in the Qinghai-Tibetan region. To be specific, the hourly radiation temperature variations and percentages of dissatisfaction of the residential building with different sunspace depth/WWR(including 0.9m/33%, 0.9m/45%, 0.9m/60%, 1.2m/33% and 1.5m/33%) were quantitatively examined. Results indicated that under the condition of 0.9m/45%, the overall average radiation temperature of the building was approximately 16℃ during the entire heating season, which could better satisfy the heating requirements. Meanwhile, the average temperature was higher, and the thermal comfort level was better under the ratio of 45% or the depth of 1.5 m, when only an individual factor in either ratio or depth was considered. These findings can provide references for the determination of dimensions of passive solar houses in high-altitude regions.
微小RNA-26a经核因子-κB信号通路对膝关节骨关节炎的滑膜炎症和疼痛机制的影响

骨关节炎属于临床骨科最为常见的一种以关节退行性变以及滑膜、软骨增生为主要表现特征的慢性关节疾病,膝关节骨关节具有极高的致残率,对患者的生活质量造成了严重的影响。本研究旨在探讨微小RNA (miRNA,miR)-26a经核因子-κB(NF-κB)信号通路对膝关节骨关节炎的滑膜炎症和疼痛机制的影响。
共同注意力训练对孤独症谱系障碍儿童共同注意能力疗效的观察

孤独症谱系障碍(autism spectrum disorder, ASD)是一组以社会交流和交往障碍,重复、刻板的行为和狭隘的兴趣为特征表现的神经发育性疾病,其发病率呈逐年递增的趋势。学者们一直致力于提高ASD儿童各项能力的康复治疗研究,但仍未能达到很满意的疗效。近年来国外学者提出ASD儿童在早期就存在共同注意力的缺陷,共同注意力缺陷可能是引起ASD儿童社会交流障碍、重复行为等问题的潜在环节,对儿童的发育起着相当重要的作用。本研究团队已经针对国内ASD儿童的共同注意力做了相关的研究,发现与正常儿童及发育迟缓儿童相比,ASD儿童都存在共同注意能力的缺陷。鉴于此,提高ASD儿童的共同注意力显得尤为重要。目前国内对于ASD儿童共同注意力的研究仅限于个案研究,缺乏多样本的组间对照研究。本研究的目的是通过组间对照研究,观察共同注意力训练能否提高ASD儿童的共同注意力。
对我国“十四五”规划若干领域发展的初步认识

2013年以来,我国发展进入了全面深刻的大转型新时期。国家对发展与环境之间的关系进行了重大调整,大力推进生态文明建设,大力推进国民经济的结构性调整,实现了国民经济新常态。我国环境状况开始改善,落后产能较大幅度减少,出口竞争力提高,中国经济的国际信用等级正在提高。但现阶段出现的问题也是相当严峻的。地区经济增长乏力,债务负担重,体制性问题突出,在发展与环境之间、经济增长与社会稳定之间、不同部门之间、不同所有制行业与企业之间,以及国内与国际之间,各种利益相互纠结,以致做出抉择往往进退两难。“十四五”规划将是推进我国发展的全面深刻转型重任中的关键期。若能处理好各方面的关系,进入高质量发展即良性发展的道路,越过“陷阱”,我国将顺利进入现代化强国的行列。
Two New Zn(II)/Cd(II) One-dimensional Coordination Polymers Based on Naphthalimide Dicarboxylic Ligand

The assemble reactions of 5-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)isophthalic acid(H 2 L) and Zn~(2+) /Cd~(2+) ions led to two compounds: [ZnL(DMSO)_2 ]·3DMSO(1) and [Cd_2 L_2(DMSO)_4 ]·DMF(2). 1 and 2 feature 1D coordination chains. Weak π -π interactions further connect the 1D chains into 2D supramolecular networks. Upon grinding, 1 and 2 show increase of quantum efficiencies(34.8 and 45.4 times of increase compared with original samples for the two compounds respectively) and red shift of the emission peaks(45 and 41 nm of shift compared with original samples for the two compounds, respectively). Both indicate the compounds are good mechanoluminescence responsive materials.
Synthesis, Crystal Structure and Antitumor Activities of N-(2-(2-hydroxy-2-phenylacetyl)phenyl)cinnamamide

The title compound N-(2-(2-hydroxy-2-phenylacetyl)phenyl)cinnamamide(C_(23) H_(19) NO_3, M_r = 357.39) has been synthesized with 2-iodoaniline and ethynylbenzene as starting materials, and its crystal structure was determined by ~1H NMR, ~(13) C NMR, H RMS and single-crystal X-ray diffraction for the first time. The crystal crystallizes in monoclinic system, space group P2_1 /c with a = 8.2850(7), b = 25.934(2), c = 8.3032(6) A, β = 95.314(7)°, V = 1776.4(3) A~3, Z = 4, T = 293(2) K, μ(CuKα) = 0.71 mm~(-1), D_c = 1.336 Mg/cm~3, 3019 reflections measured(6.832≤2θ≤129.982°), 2996 unique(R_(int)= 0.0463, R_(sigma) = 0.0549) which were used in all calculations. The final R = 0.0880(I > 2σ(I)) and wR = 0.2447(all data). The target compound has demonstrated weak or moderate anti-tumor activity against human leukemia k562cell, human promyelocytic leukemia HL-60 cell, human gastric cancer line BGC-823, Hela cell and lung cancer A549 cell.
小儿纵隔原发尤文肉瘤/原始神经外胚层肿瘤一例

综上所述,EWS/PNET发病年龄不限、进展迅速、症状不典型、不易早期发觉、影像学检査无特异性但可以早期发现病变部位、侵犯情况、有无坏死及内出血等,对诊断、手术治疗可以提供有力的依据。最终明确诊断、恶性度评价及进一步内科治疗仍需病理检查等来提供依据。推荐标准化治疗方案,具体方案及疗效目前尚无明确定论,以期此文可促进对该疾病的认识和理解。
(足母)甲皮瓣联合尺动脉腕上皮支下行支皮瓣并髂骨植骨再造拇指

目的探讨(足母)甲皮瓣联合尺动脉腕上皮支下行支皮瓣并髂骨植骨再造全拇指缺损的手术方法和临床疗效。方法自2013年1月至2016年6月,我们对6例拇指全指缺损的患者,采用(足母)甲皮瓣联合尺动脉腕上皮支下行支皮瓣并髂骨植骨再造。骨缺损均采用不带血供的髂骨条移植修复。结果术后患者伤口均I期愈合,6例再造指均顺利存活。术后8-12周摄X线片示移植骨临床愈合,取出内固定。随访时间为8~24个月,修复后拇指外形接近正常拇指,指甲生长良好,血供好,感觉恢复至S_2~S_3。3例保留掌指关节者,掌指关节活动度为0~60°。6例均可以实现对指、对掌功能。随访期内未出现骨不愈合及移植骨吸收现象。按照中华医学会拇手指再造功能评价标准评定:优4例,良2例。足部及腕部供区植皮均成活,无明显瘢痕挛缩及破溃现象,不影响患者行走及腕关节屈伸运动。结论利用(足母)甲皮瓣联合尺动脉腕上皮支下行支皮瓣并髂骨植骨组合方式全指再造拇指可以恢复拇指的良好外形,并有效减少了足部供区面积。
绝经后宫内节育器取出技术指南

宫内节育器(又称宫内节育器具)是1种高效、长效、可逆、安全、简便的避孕方法,占我国育龄期妇女常用避孕方法的第1位。当妇女绝经后,不再具有生育能力,故不再需要继续避孕,应将宫内节育器取出。由于妇女自最后一次月经至生命终止为一段生理和病理变化的特殊时期,宫内节育器取出手术与绝经前相比,其手术难度和风险增加。为规范手术操作,减少并发症发生,降低手术风险,针对绝经后的特点以及围手术期技术管理,中华医学会计划生育分会制定了《绝经后宫内节育器取出技术指南》。
FEM based Electromagnetic Signature Analysis of Winding Inter-turn Short-Circuit Fault in Inverter fed Induction Motor

The intent of this paper is to analyze the electromagnetic signature of stator winding inter-turn short-circuit fault in a closed loop speed controlled Induction Motor (IM) employing Finite Element Method. Stator winding short-circuit nearly covers 21% of faults in IM. Diagnosing the inter-turn fault at an incipient stage is one of the challenging task in the area of fault detection of IM to prevent crucial damages in industrial applications. Also detecting the faults in inverter fed IM under variable speed applications under varying load is one of the major issues in industrial drives. As the signatures of electromagnetic field contains the entire data in association with the location of rotor, stator and mechanical parts of the motor, a regular monitoring of fields in the airgap can be used to diagnose the inter-turn fault in the stator winding of IM. In this direction, an IM is modeled with several inter-turn fault severities like 30 turns, 15 turns, 5 turns & 1 turn short using ANSYS Maxwell FEA tool and coupled with ANSYS Simplorer for loading arrangements. The PWM inverter with closed loop speed controlled strategy is implemented in Matlab Simulink and co-simulated with ANSYS Simplorer to integrate all the components in one common simulation platform environment for accurate design & analysis for realistic simulation. Several electromagnetic variables like flux density, flux lines and airgap flux density distribution over the machine are analyzed. The spatial FFT spectrum of radial component of flux density in the airgap contains the information related to the diagnosis of inter-turn fault at the incipient stage.
Effects of Voltage Sag on the Performance of Induction Motor Based on a New Transient Sequence Component Method

Voltage sag is one of the most common power quality disturbances in industry, which causes huge inrush currents in stator windings of induction motors, and adversely impacts the motor secure operation. This paper firstly introduces a 2D Time-Stepping multi-slice finite element method (2D T-S multi-slice FEM) which is used for calculating the magnetic field distribution in induction motors under different sag events. Then the paper deduces the transient analytical expression of stator inrush current based on the classical theory of AC motors and presents a separation method for the positive, negative and zero sequence values based on instantaneous currents. With this method, the paper studies the influences of voltage sag amplitude, phase-angle jump and initial phase angle on the stator positive- and negative-sequence peak currents of 5.5 kW and 55 kW induction motors. This paper further proposes a motor protection method under voltage sag condition with the stator negative-sequence peak currents as the protection threshold, so that the protection false trip can be avoided effectively. Finally, the calculation and analysis results are validated by the comparison of calculated and measured stator peak value of the 5.5 kW induction motor.
Study on Vector Magnetic Properties of Magnetic Materials Using Hybrid Hysteresis Model

This paper presents a method to study the vector magnetic properties of magnetic materials under alternating and rotational magnetic field using 2-D vector hybrid hysteresis model. Combining Preisach model and Stoner-Wohlfarth (S-W) model, the vector hybrid hysteresis model is established for magnetic materials. The alternating and rotational hysteresis properties are calculated under different excitation frequency, respectively. And the computed results are compared with the experimental measurement ones. It is shown that the vector model can simulate the alternating and rotational magnetic properties effectively under low magnetization fields and low excitation frequency.
Visualization and Quantitative Evaluation of Eddy Current Loss in Bar-Wound Type Permanent Magnet Synchronous Motor for Mild-Hybrid Vehicles

This paper describes the conductor eddy current loss that occurs in a permanent magnet type synchronous motor with a distributed winding stator using a rectangular copper wire designed for mild hybrid system applications for small vehicles. Compared with the conventional round wire inserter method, the space factor can be improved and the coil-end length can be shortened by applying a so-called hairpin windings using a pre-formed into hairpin shape of bar conductor, and as a result, DC current resistance of the armature winding can be reduced. However, since the conductor cross-sectional area tends to increases, the conductor eddy current loss generated by the space harmonics linkage becomes too large to ignore. In order to study the reduction of the conductor eddy current loss, it is important to visualize the spatial leakage flux distribution which causes loss and finely analyze how the magnetic path is formed. Therefore, analysis of the conductor eddy current loss distribution generated in the bar-wound conductor is performed using the CAE model that faithfully reproduces the coil-end shape of the actual machine. Furthermore, it was qualitatively clarified what ratio of conductor eddy current loss at various driving points. Finally, the results of preliminary study on reduction of conductor eddy current loss are reported.
System-Level Efficiency Optimization of a Linear Induction Motor Drive System

Linear induction motors are superior to rotary induction motors in direct drive systems because they can generate direct forward thrust force independent of mechanical transmission. However, due to the large air gap and cut-open magnetic circuit, their efficiency and power factor are quite low, which limit their application in high power drive systems. To attempt this challenge, this work presents a system-level optimization method for a single-sided linear induction motor drive system. Not only the motor but also the control system is included in the analysis. A system-level optimization method is employed to gain optimal steady-state and dynamic performances. To validate the effectiveness of the proposed optimization method, experimental results on a linear induction motor drive are presented and discussed.
Experimental and Numerical Studies of a Linear Synchronous Motor with the Secondary Made of Coated Superconductor

Thrust tests of a linear synchronous motor (LSM) with its secondary made of coated superconducting coils were conducted via the built prototype over the traditional copper windings. A numerical model of the superconducting LSM was made and the measured data of experiment validate its reliability. The nonlinear resistivity of coated superconductor was electromagnetically modeled by resorting to the power law in conjunction with the constitutive relationship of conductor. Based on the numerical model, we carried out a set of transient studies to make a forecast about the superiority of the proposed high temperature superconducting (HTS) LSM, such as magnetic field distribution and the time evolution of thrust together with the speed in different loads and frequencies. The achieved results clearly confirm that the proposed HTS LSM has the advantages to work as a candidate for developing the high-thrust LSM with a large air gap.
Hybrid Excited Permanent Magnet Machines for Electric and Hybrid Electric Vehicles

This paper reviews various hybrid excited (HE) machines from the perspective of location of PM and DC excitation, series/parallel connection of PM and DC excited magnetic fields, and 2D/3D magnetic fields, respectively. The advantages as well as drawbacks of each category are analyzed. Since an additional control degree, i.e. DC excitation, is introduced in the HE machine, the flux weakening control strategies are more complex. The flux weakening performance as well as efficiency are compared with different control strategies. Then, the potential to mitigate the risk of uncontrolled overvoltage fault at high speed operation is highlighted by controlling the field excitation. Since additional DC coils are usually required for HE machines compared with pure PM excitation, the spatial confliction inevitably results in electromagnetic performance reduction. Finally, the technique to integrate the field and armature windings with open-winding drive circuit is introduced, and novel HE machines without a DC coil are summarized.
Influence of Inner/Outer Stator Pole Ratio and Relative Position on Electromagnetic Performance of Partitioned Stator Switched Flux Permanent Magnet Machines

Based on the 6-pole outer stator (armature winding-stator), the influence of inner (permanent magnet-stator)/outer stator pole ratio n (n=NIS/NOS), stator relative positions and rotor pole number combinations on electromagnetic performance of partitioned stator switched flux permanent magnet (PM) machines (PS-SFPMMs) is investigated in this paper. Since the armature windings and PMs are located in two separated stators and PMs are stationary, PS-SFPMMs have high fault tolerance capabilities. To maximize the torque performance, the PM of inner stator pole should be aligned with outer stator pole when n is odd while the iron rib of inner stator pole should be aligned with outer stator pole when n is even. No matter what n is selected, the rotor pole number NR can be any integers except the phase number and its multiples. The analysis results indicate that the optimal NR is closed to (NIS+NOS)/2 and it is odd when n is odd while it is even when n is even. Meanwhile, symmetrical phase back-EMF waveform will be obtained when the ratio of Min(NOS, NIS) to the greatest common divisor of Min(NOS, NIS) and NR is even. Based on the optimal rotor pole numbers for 6-pole outer stator with different n and corresponding optimal relative position together with same rated copper loss, the average torque is improved by 18.4%, 25.1% and 25.7% respectively in PS-SFPMMs with n equal to 2, 3 and 4 when compared with PS-SFPMM with n equal to 1. The analyses are validated by experiment results of the prototype machine.
Effects of temperature on flowering phenological traits of Populus euphratica Oliv. and Populus pruinosa Schrenk populations, Xinjiang, China

The aims of this study were to explore the interspecific differences of Populus euphratica Oliv. and Populus pruinosa Schrenk populations and the intraspecific differences of males and females within the same species in flowering phenological traits, and the effects of temperatures on flowering phenological traits in different growth years (2001–2003 and 2013–2015). The results showed that P. euphratica population flowered earlier than P. pruinosa population. Moreover, flowering phenological period of population, number of days of flowering phenological period per population, number of days of flowering phenological period per plant and average number of days of flowering period per plant of P. euphratica population were less than those of P. pruinosa population. The differences between male and female within the same species indicated that the flowering periods of males P. euphratica and P. pruinosa populations were earlier than those of female plants. For both species, flowering phenological traits were significantly and negatively correlated with the average temperatures in previous ten days, previous one month and previous three months of flowering. Both species are sensitive to temperature changes and adjust to the changes by advancing the start of flowering and prolonging the duration of flowering.
New high-strength Ti–Al–V–Mo alloy:from high-throughput composition design to mechanical properties

The high-throughput diffusion-multiple technique and thermodynamics databases were used to design new high-strength Ti alloys.The composition–microstructure–property relationships of the Ti64–xMo alloys were obtained.The phase fraction and composition of the α and β phases of the Ti64–xMo alloys were calculated using the Thermo-Calc software.After aging at 600°C,the Ti64–6Mo alloy precipitated ultrafine α phases.This phenomenon was explained on the basis of the pseudo-spinodal mechanism by calculating the Gibbs energy curves of the α and β phases of the Ti64–xMo alloys at 600°C.Bulk forged Ti64–6Mo alloy exhibited high strength and moderate plasticity after α/β-phase-field solution treatment plus aging.The tensile properties of the alloy were determined by the size and morphology of the primary and secondary α phases and by the β grain size.
Comparison of a commercial powder and a powder produced from Ti-6Al-4V chips and their effects on compacts sintered by the sinter-HIP method

The present paper is related to the conversion of Ti-6Al-4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was applied to Ti-6Al-4V chips and the obtained powder was subsequently compacted. The compacted samples were sintered by the sinter hot isostatic pressing (sinter-HIP) method at 1200°C under high vacuum, their mechanical properties and microstructure were investigated and compared with those of commercial powder compacts subjected to the same preparation processes. The results showed that the produced powder exhibits greater flowability and higher apparent density than the commercial powder. However, the sintered products prepared from the commercial powder exhibited a higher relative density, lower porosity, and, as a result, greater flexural strength compared with the sintered compacts prepared from the produced powder. In addition, transgranular fracture was greater in the sintered products of the commercial powder. The microstructural studies revealed that the sintered products made from both the commercial and the produced powders consisted of α-and β-phase but contained more α-phase. All of the examined properties were found to be substantially affected by the particle size of the powders.