mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Geodynamic Background of Intracontinental Cenozoic Alkaline Volcanic Rocks in Laojiezi, Western Yangtze Craton: Constraints from Sr-Nd-Hf-O Isotopes

The Laojiezi alkaline volcanic rocks, which are located in the intraplate region of the Yangtze craton, coincide with the formation of the Jinshajiang-Ailaoshan-Red River alkaline rock belt. Although this belt has been widely studied by geologists because of its porphyry-related Pb-Ag-Au polymetallic deposit and geotectonic location, the material sources of this belt are still debate. Whole-rock analyses show that these rocks have high total alkali contents (3.73-11.08wt%), and their aluminum saturation index (ASI) values widely vary from 0.82 to 3.07, which comprise a metaluminous-peraluminous magma series. These rocks are characterized by high K (K_2O/Na_2O>1) and low Ti and Mg contents; enrichment in large-ion lithophile elements, such as Rb, Ba, K and light rare earth elements; and depletion in high field strength elements, such as Ta, Nb, P, and Ti. These rocks exhibit moderate Eu (Eu/Eu~*=0.86-1.04) and Ce (Ce/Ce~*=0.63-0.96) anomalies. Their (~(87)Sr/~(86)Sr)i, ε_(Nd)(t), zircon εHf(t) and δ~(18)O values range from 0.70839 to 0.71013, from -10.16 to -12.45, from -19.6 to -5.8, and from 5.69‰ to 8.54‰, respectively, and their Nd and Hf two-stage model ages (TDM2) are 1.67-1.86 Ga and 1.27-2.02 Ga, respectively. These data reflect the primary partial melting of Paleoproterozoic to Mesoproterozoic lower crust with minor residual continental lithospheric mantle and supracrustal metasediments. The lithosphere was likely thickened along the southeastern margin of the Tibetan Plateau following the Indian-Asian continentcontinent collision (65-41 Ma). During the post-collision phase (36-16 Ma), the transition from a compressional to extensional setting triggered the convective removal of the over-thickened CLM beneath the Yangtze craton, which led to the upwelling of asthenospheric materials. This process created alkali-rich and high-K magma through the partial melting of the thickened lower crust. Magma that carried Cu-Au-Pb-Ag minerals was emplaced by strike-slip motion along the E-to W-or ENE-to WSWtrending tectonically weak zone, finally forming an alkaline porphyry Cu-Au-Pb-Ag polymetallic deposit.
18氟-脱氧葡萄糖正电子发射断层显像-电子计算机断层扫描术在感染性心内膜炎临床诊断中的应用

感染性心内膜炎(infective endocarditis,IE)是指病原微生物经血行途径侵犯心内膜、心瓣膜、邻近大动脉内膜伴有赘生物形成的感染性疾病。目前IE的临床诊断多采用改良的杜克标准,然而临床上对IE的早期诊断依旧非常困难。随着影像学技术的不断发展,三维超声心动图、心脏CT和MRI、核素显像等技术被应用到IE的诊断中,2015年欧洲心脏病学会更是将18氟-脱氧葡萄糖(18-fluoro-2-deoxyglucose-fluorodeoxyglucose,~(18)F-FDG)正电子发射断层显像术(positronemission tomography. PET)-CT纳入了IE的主要诊断标准中。然而国内对于~(18)F-FDG PET-CT诊断IE的研究尚缺乏,本研究对16例疑诊IE并行~(18)F-FDG PET-CT的患者的临床资料及影像学表现进行回顾性分析,旨在评估~(18)F-FDG PET-CT对辅助诊断IE的临床价值。
鸡西盆地煤炭资源枯竭矿区钻获高含气量煤系储层

鸡西盆地煤层气勘探始于煤矿瓦斯治理需求,目的层为1000 m以浅的城子河组上段14#煤、穆棱组3#煤等;14#煤以下的煤层气或煤系气极少关注和研究。本次研究的目的是落实鸡西盆地煤炭资源枯竭矿区“原位区”1000 m以深的下白垩统城子河组中—下段煤系地层发育情况,获取煤系储层特征及含气性等参数,评价煤系气(煤层气、煤系页岩气、致密砂岩气)资源潜力;探索深部煤层及煤系泥页岩、致密砂岩储层压裂工艺和“三气”合层排采工艺,获取煤系气产能评价参数,为进一步勘查评价提供基础资料。
PCSK9在脓毒症治疗的关键地位

脓毒症时,病原菌脂质(pathogenic lipid,PL)如脂多糖是诱发严重炎症反应的主要成分.血浆中低密度脂蛋白(LDL)在PL清除过程中起到重要作用.通过调节前蛋白转化酶枯草溶菌素9(PCSK9)能加速LDL代谢,从而促进PL清除,因此PCSK9可能成为治疗脓毒症的有效靶点.了解PCSK9在清除PL中的详细机制和干预手段对防治脓毒症具有重要指导意义.
Review on Li-insertion/extraction Mechanisms of LiFePO_4 Cathode Materials

The work distills the main mechanisms during the lithium insertion/extraction of LiFePO_4 cathode materials. The “diffusion-controlled” and “phase-boundary controlled” mechanism are especially illustrated. Meanwhile, some recent observation and analyses by in-situ or in operando on the Li-insertion/extraction of LiFePO_4 are summarized and prospected.
肾移植治疗补体因子H突变型非典型性溶血性尿毒症二例

溶血性尿毒症是以微血管血栓病(Thrombotic Microan-giopathy,TMA)为病理特征的一种罕见病,其临床表现以血小板减少、溶血性贫血和急性肾损伤三联征为主要特征。其中非典型性溶血性尿毒症(atypical haemolytic uraemic syndrome, aHUS)极为罕见,肾移植治疗aHUS在移植术后容易复发,且移植肾丢失风险发生较高,我院报道2016至2017年2例肾移植治疗H因子突变型aHUS患者,现报告如下。
Akt/mTOR信号通路在肺高血压肺血管及右心室重构中作用的研究进展

肺高血压以肺血管阻力进行性升高为主要特征,可导致患者右心衰竭甚至死亡,其主要病理生理改变是肺血管和右心室重构、肺小动脉痉挛及原位血栓形成等,而重构在各种类型肺高血压的发病过程中起关键作用。肺高血压及其重构的机制复杂,包括炎症状态以及细胞增殖、代谢、自噬和凋亡等改变。许多信号通路在重构的多个环节中起着不同的调控作用,近年研究发现蛋白激酶B/哺乳动物雷帕霉素靶点(Akt/mTOR)信号通路几乎参与了重构的每个环节。研究Akt/mTOR信号通路中的关键因子和重要蛋白对肺高血压靶向治疗更精准的意义重大。本文就Akt/mTOR信号通路及其抑制剂在肺高血压中作用的研究进展做一综述。
Improved three-vector based dead-beat model predictive direct power control strategy for grid-connected inverters

Since only one inverter voltage vector is applied during each duty cycle,traditional model predictive direct power control (MPDPC) for grid-connected inverters (GCIs) results in serious harmonics in current and power.Moreover,a high sampling frequency is needed to ensure satisfactory steady-state performance,which is contradictory to its long execution time due to the iterative prediction calculations.To solve these problems,a novel dead-beat MPDPC strategy is proposed,using two active inverter voltage vectors and one zero inverter voltage vector during each duty cycle.Adoption of three inverter vectors ensures a constant switching frequency.Thus,smooth steady-state performance of both current and power can be obtained.Unlike the traditional three-vector based MPDPC strategy,the proposed three vectors are selected based on the power errors rather than the sector where the grid voltage vector is located,which ensures that the duration times of the selected vectors are positive all the time.Iterative calculations of the cost function in traditional predictive control are also removed,which makes the proposed strategy easy to implement on digital signal processors (DSPs) for industrial applications.Results of experiments based on a 1 kW inverter setup validate the feasibility of the proposed three-vector based dead-beat MPDPC strategy.
西藏林芝市旋毛虫病健康教育浅析

旋毛虫病是旋毛线虫所致的动物源性人畜共患寄生虫病,是人类因生食或半生食含旋毛虫幼虫的肉类而感染。临床特征主要为胃肠道症状、发热、肌肉剧烈疼痛、嗜酸性粒细胞明显增高。旋毛虫病对人类健康危害较大,在我国被列为人畜共患寄生虫病之首,也是西藏林芝市的主要寄生虫病之一。由于林芝市旋毛虫病健康教育开展起步晚、起点低,且存在经验不足、缺乏评价考核体系等问题,严重阻滞了旋毛虫病防治的效果。作者对林芝市旋毛虫病健康教育现状进行分析,为旋毛虫病防治提供借鉴。
Improved thermal resistance network model of motorized spindle system considering temperature variation of cooling system

In the motorized spindle system of a computer numerical control (CNC) machine tool, internal heat sources are formed during high-speed rotation; these cause thermal errors and affect the machining accuracy. To address this problem, in this study, a thermal resistance network model of the motorized spindle system is established based on the heat transfer theory. The heat balance equations of the critical thermal nodes are established according to this model with Kirchhoff’s law. Then, they are solved using the Newmark-β method to obtain the temperature of each main component, and steady thermal analysis and transient thermal analysis of the motorized spindle system are performed. In order to obtain accurate thermal characteristics of the spindle system, the thermalconduction resistance of each component and the thermalconvection resistance between the cooling system and the components of the spindle system are accurately obtained considering the effect of the heat exchanger on the temperature of the coolant in the cooling system. Simultaneously, high-precision magnetic temperature sensors are used to detect the temperature variation of the spindle in the CNC machining center at different rotational speeds. The experimental results demonstrate that the thermal resistance network model can predict the temperature field distribution in the spindle system with reasonable accuracy. In addition, the influences of the rotational speed and cooling conditions on the temperature increase of the main components of the spindle system are analyzed. Finally, a few recommendations are provided to improve the thermal performance of the spindle system under different operational conditions.
The role of rhizobacteria in rice plants: Growth and mitigation of toxicity

Allelopathic compounds reduce the growth and productivity of upland rice plants, especially in consecutive plantations. The rhizobacteria Pseudomonas fluorescens BRM-32111 and Burkholderia pyrrocinia BRM-32113 have been recorded as growth promoters in rice. This study was developed to understand the effect of the application of rhizobacteria on upland rice plants in consecutive plantations. Experiments were conducted in a completely randomized design with four replications of four treatments: rice seed inoculated with P. fluorescens BRM-32111, rice seed inoculated with B. pyrrocinia BRM-32113 (both sown on soil with rice residue), non-inoculated plants sown on soil with rice residue (control with residue (WR)), and non-inoculated plants on soil with no residue (NR). Roots and seedling growth were adversely affected by allelopathic compounds in control WR plants. Plants inoculated with rhizobacteria P. fluorescens BRM-32111 or B. pyrrocinia BRM-32113 induced an increase of 88% in biomass, 3% in the leaf area, 40% in length, 67% in root biomass, 21% in chlorophyll a, 53% in chlorophyll (a+b), 50% in rate of carbon assimilation (A), 227% in A/rubisco carboxylation efficiency (Ci) and 63% in water use efficiency (WUE) compared to control WR plants. These results indicate that rhizobacteria P. fluorescens BRM-32111 and B. pyrrocinia BRM-32113 increase the tolerance of rice plants to stress from allelochemicals. There are possible practical agricultural applications of these results for mitigating the effects of environmental allelochemistry on upland rice.
Investigation of operation performance of air carrying energy radiant air-conditioning system based on CFD and thermodynamic model

This study aims to investigate the operation performance of a new terminal form of radiant airconditioning system called the air carrying energy radiant air-conditioning system (ACERS). Three summer operation conditions, namely steady condition (without opening door and window), open-door condition and open-window condition, are researched in a residential apartment using experimental, computational fluid dynamics (CFD) simulation and thermodynamic methods. The concept of dynamic synergistic operation of mechanical ventilation driven by the air-conditioning system and natural ventilation driven by the open door or window is proposed. A thermodynamic model formulated by the dynamic enthalpy equation, dynamic temperature equation and dynamic moisture equation is developed to analyze the heat and mass transfer process of the test room under the synergistic operation of mixing ventilation. Moreover, the CFD simulation results are used to analyze the synergistic operation and thermodynamic energy transfer of the test room under the mixing ventilation of ACERS and open door/window. It is indicated that ACERS is an important technology with a low temperature gradient of less than 0.1 °C between the head (1.5 m) and ankle level (0.1 m) and low velocity of approximately 0.1 m/s in the occupied zone under the steady condition. The thickness of the boundary zone under the orifice plate of ACERS under the steady, open-door and open-window conditions is 12, 6, and 8 cm, respectively, which can effectively prevent condensation. This study proves that ACERS is a promising technology for air conditioning in residential buildings in regions with hot and humid summers.
Effects of dietary phosphorous supplementation on laying performance, egg quality, bone health and immune responses of laying hens challenged with Escherichia coli lipopolysaccharide

Background: Phosphorus is an essential nutrient to maintain poultry health and performance. The objective of this study was to evaluate the effect of dietary phosphorus levels on egg production, egg quality, bone health, immune responses of laying hens challenged with Escherichia coli lipopolysaccharide. Methods: Three hundred laying hens at 28 wk were randomly divided into 2 dietary treatments with 10 replicates of 15 birds. The wheat-soybean based diets contained either 0.12% or 0.4% non-phytate phosphorus (NPP). At 32 wk of age, all the birds of each dietary treatment were injected into the abdomen with 1.5 mg/kg body weight (BW) of either LPS or saline once a day at 24-h intervals for continuous 9 d. The performance of laying hens was evaluated for 9 d. The eggs after the fifth injection were collected to value the egg quality. Three hours after the first injection, blood was collected to measure serum metabolite and immune response associated parameters. Three hours after the fifth injection, the hens were euthanized to obtain tibia, cecal tonsils and jejunum. Results: Compared with saline-injected hens, LPS-injected hens had lower feed intake and egg production (P < 0.05). Eggshell thickness, strength, albumin height and Haugh unit were significantly increased in LPS-injected hens compared with saline-injected hens (P < 0.05). Furthermore, laying hens challenged with LPS had lower villious height/ crypt depth ration than those received saline. Serum calcium, phosphorus and SOD activities significantly decreased in the LPS-injected hens compared with the control (P < 0.05). LPS up-regulated expression of IL-1β, IL-6 and IL-10 in cecum, and serum concentration of MDA, IL-1β and IL-6 (P < 0.05), whereas 0.40% dietary non-phytate phosphorus supplementation significantly increased (P < 0.05) villi height/crypt depth ratio, decreased (P < 0.05) serum MDA and IFN-γ concentration compared with the 0.12% non-phytate phosphorus group. Conclusion: In summary, this study demonstrates that 0.40% dietary non-phytate phosphorus supplementation significantly increased calcium and phosphorus levels of eggshell, increased villi height/crypt depth ratio, decreased serum MDA and IFN-γ concentration compared with the 0.12% non-phytate phosphorus groups. The results indicate that high level of dietary non-phytate phosphorus exerts a potential effect in alleviating systemic inflammation of LPSchallenged laying hens.
Molecular cloning and characterization of the endothelin 3 gene in black bone sheep

Background: Black bone sheep was first discovered in Yunnan province of China in 1970, with unique black pigmentation on the body and internal organs. Endothelin 3 (EDN3) has been known as a key gene causing hyperpigmentation in black bone chicken, the Silky fowl. Methods: In this study, EDN3 was employed as a candidate gene for regulating black color pigmentation. First, EDN3 was cloned from sheep to obtain the full-length cDNA by using the rapid amplification of cDNA ends (RACE). Genomic EDN3 was screened and a total of thirty predicted single nucleotide polymorphisms (SNPs) were genotyped for allele and genotype frequency analysis in a case-control study involving two black bone sheep populations. Genomic copy number analysis of EDN3 in sheep was conducted to measure the variation in copy number. EDN3 expression levels were observed among the groups in adult liver, lymph node, and kidney tissues, as well as embryo kidney samples. Also, among the tissues of black bone and non-black bone sheep. Results: The size of the full-length cDNA was 1,578 bp, which included 426 bp of 5′-untranslated region (5′-UTR), an open reading frame (ORF) of 639 bp encoding a protein of 212 amino acids, and a 3′-UTR of 513 bp. Genotype and allele frequencies of all the discovered SNPs were found insignificantly different in black bone and non-black bone sheep (P >0.05). Genomic copy number analysis of EDN3 in sheep revealed no significant difference between the two sheep groups. No significant variations were found in the adult liver and kidney embryo samples. However, the expression in lymph node and kidney tissue was significantly higher in black bone sheep than that in non-black bone sheep (P < 0.05). Significant variations in the EDN3 expression levels were observed among the tissues of nonblack bone sheep. Conclusions: The findings of the present study indicate that unlike in Silky chickens, EDN3 is not responsible for hyperpigmentation but may play a key functional role in immune and excretory systems of black bone sheep.
Helicobacter pylori and portal hypertensive gastropathy

H.pylori lives in the gastric epithelial cells,sometimes in gastric glands.Whether or not the proliferation and biological behavior of H.pylori can be influenced by the status of the gastric mucosa is still unknown.Portal hypertensive gastropathy (PHG) is a blood drainage obstructive disease.In this pathologic environment,gastric mucosa may be further impaired when patients are infected with H.pylori.The role of H.pylori in the pathogenesis of PHG and the effect of PHG on H.pylori infection is poorly defined and controversial.We wonder whether H.pylori or its products can migrate to distant organ after anatomical changes of gastric mucosa by PHG.
基于拓扑优化技术的成型机轴承座动刚度特性改进设计

为了改善成型机轴承座的动态特性,对轴承座结构进行基于频率响应拓扑优化设计,实现轴承座的轻量化及提高其动刚度特性。对轴承座的工作状况进行分析,并基于HyperMesh对其进行有限元前处理。以轴承座受载节点的频响位移最小化为优化目标,以优化前后结构的体积比为约束条件构建其频响优化模型,并基于优化准则法进行拓扑优化求解,此外,利用OSSmooth对提取优化结果的CAD模型并再分析。通过优化前后动态特性可得:成型机轴承座优化后的动刚度值和一阶固有频率大大地增加,不仅改善了轴承座的动态特性还实现了结构的轻量化设计。
棉纺厂空调监控系统改造

应企业要求,根据某棉纺厂空调系统的现状和对温湿度控制的工艺要求,对该厂空调系统进行了自动化改造。监控系统由触摸屏、PLC、变频器、温湿度传感器等组成。采用PLC模拟量输入模块,采集现场温湿度值,PLC根据设置的温湿度值,对温湿度控制分别采用不同的闭环控制方法,实现了棉纺厂温湿度的自动控制。解决了长期困扰企业的温湿度差异较大引起的产品质量问题和能耗偏高、操作员劳动强度大的问题。
基于MATLAB的PUMA560机器人正逆解研究

通过对满足pieper准则的PUMA560机器人分析,建立其D-H参数正向运动数学模型,并求出机器人正向运动学解。在正向运动学的基础上,利用矩阵求逆的方法生成12组非线性方程,并利用代数法求解该方程,获得机器人各关节角度变量的8组解。基于实际工况对逆解进行选取使机器人的运转性能达到最优。机器人的正逆解为轨迹规划研究奠定了基础,对于提高机器人的使用寿命、避障能力和工作稳定性有着重要的意义。
干细胞在神经病理性疼痛治疗中的研究进展

神经病理性疼痛在人群中发病率不断升高,其发病机制复杂且治疗效果不佳。长期存在的疼痛严重影响病人的生活质量和精神状态。由于神经病理性疼痛的发生发展可能涉及神经损伤及神经细胞的异常修复,近年有学者提出将干细胞引入神经病理性疼痛的治疗,帮助修复损伤的神经,并在实验室研究取得了一定进展。本文就不同起源的干细胞在神经病理性疼痛治疗中的作用及研究进展做一综述,阐述不同干细胞治疗的特点及相关研究成果,并就干细胞治疗现存问题展开讨论和展望,为今后干细胞移植在神经病理性疼痛治疗中的进一步应用提供参考。
潭两优39制种母本的轻简栽培技术

抛秧和直播是轻简型栽培的主要方式,这种简单实用、省工、省成本、增产、增收的方法在大田种子生产上运用比较广泛。介绍了潭两优39制种母本轻简栽培的相关技术措施。
前哨淋巴结示踪在子宫内膜癌手术中应用的相关问题

前哨淋巴结(SLN)体现了肿瘤的精准治疗,最近被用于子宫内膜癌手术,目的是降低淋巴结切除相关并发症,并从淋巴结状态获得预后信息。本文介绍了子宫内膜癌患者治疗时采用SLN评估的相关问题及SLN技术的发展趋势。
从现代生物学认识上火

上火是临床常见的一种轻微但易反复的疾病,包括口腔溃疡、牙龈肿痛、口燥咽干、鼻衄、目赤,并可伴有小便短赤、大便干燥等症状,多由精神紧张、过度疲劳、辛热药食等所诱发。从现代医学看,上火既包括了一些亚健康的状态,也包含了头面部某些器官皮肤黏膜的炎症性病变,如复发性口腔溃疡,慢性牙龈炎等等。
南通市青少年健康危险行为现状研究

目的了解南通市青少年健康危险行为吸烟及饮酒状况。方法采用SPSS 19. 0软件对健康危险行为调查结果进行统计分析。结果南通市青少年学生尝试吸烟率为13. 36%,13岁以下吸烟率为6. 62%,被动吸烟率为30. 48%,男生发生率均高于女生,差异均有统计学意义( P < 0. 05) 。尝试饮酒率46. 28%,现在饮酒率为21. 15%,过去12个月醉酒率为9. 44%,男生发生率均高于女生,差异均有统计学意义( P < 0. 05) 。结论应加强对青少年的健康教育,宣传吸烟、过量饮酒的危害。相关部门加大公共场所控烟工作力度,减少青少年被动吸烟暴露率。
Luminescence properties of dysprosium doped YVO_4 phosphor

Trivalent dysprosium (Dy~(3+)) activated nanocrystalline yttrium vanadate (YVO_4) phosphor was synthesized via co-precipitation method. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), optical absorption and photoluminescence (PL) techniques. The XRD patterns reveal the tetragonal crystalline phase. SEM images reveal that Dy doped YVO_4 nanocrystals are agglomerated. EDAX confirms the formation of YVO_4:Dy. FTIR spectrum shows two strong absorption bands at 459 and 761 cm~(-1). Optical absorption spectrum showed the surface defects in the as-prepared samples. The PL emission spectrum shows two characteristic emission bands at 485 and 575 nm. The strong yellow emission peak at 575 nm is assigned to ~4F_(9/2)→H_(13/2) hyper sensitive transition of Dy~(3+) ions. Study of CIE chromaticity diagram indicates the suitability of the phosphor for the development of yellow-green LEDs.
Synthesis of La_2MoO_6@MWCNTs composite catalysts as Pt-free counter electrodes for dye-sensitized solar cell

Pt-free counter electrode (CE) composed of La_2MoO_6 (La_2O_3-MoO_3) was successfully synthesized by simple pyrolysis of lanthanum acetate (C_6H_9O_6La·xH_2O) and hexaammonium heptamolybdate tetrahydrate ((NH_4)_6Mo_7O_(24)·4H_2O). Furthermore, three proportions composites catalysts of La_2MoO_6@MWCNTs based on La_2MoO_6 and multiwall carbon nanotubes (MWCNTs) were prepared and characterized as Ptfree catalyst for CE in dye-sensitized solar cells (DSSCs). The morphology and structure of La_2MoO_6@MWCNTs composites were determined by scanning electron microscopy, transmission electron microscope and X-ray diffraction. The electrochemical performance of La_2MoO_6@MWCNTs composite catalysts for CEs was determined by photocurrent-voltage measurements, cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization. The power conversion efficiencies of 4.68%, 4.87% and 5.06% are obtained for La_2MoO_6:MWCNTs with the mass ratios of 5:1, 3:1 and 1:1 towards the reduction of I3 e to Ie under the same conditions, respectively, which are superior to those of MWCNTs (3.94%) and La_2MoO_6 (1.71%) electrodes. The experimental results reveal that the presence of MWCNTs results in an augmented active catalytic surface area and enhanced charge transfer from CE to the electrolyte.
Recycled Nd-Fe-B sintered magnets prepared from sludges by calcium reduction-diffusion process

Environmental friendly recycling process for Nd-Fe-B sintered magnet sludges generated in the manufacturing process, which contain large amount of rare earth, including Nd, Pr and Dy, is badly needed so far. In present study, we have developed an effective route to obtain recycled sintered magnets from Nd-Fe-B sintered magnet sludges by calcium reduction-diffusion (RD) process. Compared to conventional recycling process, our research is focused on recovering most of the useful elements, including Nd, Pr, Dy, Co, and Fe together instead of just rare earth elements. To improve the recycling efficiency and reduce pollution, the co-precipitating parameters were simulated and calculated using MATLAB software. Most of useful elements were recovered by a co-precipitation method, and the obtained composite powders were then directly fabricated as recycled Nd-Fe-B powders by a calcium reduction-diffusion (RD) method. The recovery rates are 98%, 99%, 99%, 93%, and 99%, for Nd, Pr, Dy, Co, and Fe, respectively. The amount of useful elements contained in the recovered composite powders is greater than 99.71 wt%. The process of RD for synthesizing Nd_2Fe_(14)B and subsequently removing CaO was thoroughly investigated. Furthermore, the recycled Nd-Fe-B magnet exhibits a remanence of 1.1 T, a coercivity of 1053 kA/m, and an energy product of 235.6 kJ/m~3, respectively, indicating that recycled Nd-Fe-B sintered magnet was successfully recovered from the severely contaminated sludges via an effective recycling route.
Relating atomic local structures and Curie temperature of NdFeB permanent magnets: an X-ray absorption spectroscopic study

Relationship between atomic local structures and Curie temperature of NdFeB permanent magnets was investigated semi-quantitatively using synchrotron radiation technique. Fe K-edge X-ray absorption spectroscopy (XAS) was employed to study the local structure of Fe atoms for samples before and after doping Dy, Tb or Gd. It is found that the bond lengths and coordination numbers are changed. Thus, the exchange interaction between Fe atoms increases with Dy, Tb or Gd doping, resulting in the improvement of Curie temperature of NdFeB permanent magnets. The doping effect is proven by experimental measurement of the magnetic properties. Microstructural characterization using scanning electron microscopy (SEM) was also used to further analyze the effect of different rare earth elements doping on Curie temperature of NdFeB permanent magnets.