检索结果-南通市图书馆

Process optimization of neodymium chloride solutions precipitated by magnesium bicarbonate

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2019年第4期37卷 437-442页

作者： Yannan Yan Yang Xu xiaowei huang Zongyu Feng Yongke Hou Kai Li Liangshi Wang Yihanna Hu National Engineering Research Center for Rare Earth Materials GRINM Group Co. Ltd. Grirem Advanced Materials Co. Ltd. GRINM Group Co. Ltd. China United Test & Certification Co. Ltd.

Rare earths(REs) are of vital importance for the development of new materials and green energy.Magnesium bicarbonate is one of the most recyclable and environmental-friendly precipitant for REs recovery from leaching solutions. Nd_2(CO_3)_3 has difficulties in industrial production. So in this study,the precipitation of neodymium from chloride solution by magnesium bicarbonate are investigated. The effects of feeding method, [HCO_3^-]/[Nd^(3+)] mole ratio, feeding speed and reaction temperature on yield and impurity(magnesia) content are systematically studied. Results show that the impurity(magnesia)content decreases to 0.010 wt% with a yield approaching to 100% obtained under the conditions of[HCO_3^-]/[Nd^(3+)] = 3.00 by parallel flow addition at 50 ℃. The major impurity(magnesia) in rare earth carbonates mainly presents in the form of physical absorption, which can be easily removed by scrubbing. Therefore, it offers a promising green process that uses magnesium bicarbonate to produce neodymium carbonate due to its cycling of carbon dioxide, magnesium salt and waste water.

关键词： Rare earth Magnesium bicarbonate Precipitation process Yield

Recovery of rare earths and aluminum from FCC waste slag by acid leaching and selective precipitation

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2017年第11期35卷 1141-1148页

作者： Jinyu wang xiaowei huang Dali Cui Liangshi Wang Zongyu Feng Bin Hu Zhiqi Long Na Zhao National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals Beijing 100088 China Grirem Advanced Materials Co. Ltd. Beijing 100088 China

This paper investigated the recovery of rare earth elements(REEs) and aluminum(AI) from the waste slag discharged by FCC catalyst factory(FCC waste slag) via acid leaching and selective precipitation.Analysis methods such as ICP-AES, XRF and XRD were applied to obtain experiment data. The maximum leaching efficiency of REEs and Al was achieved at pH value of 1 and with liquid to solid ratio of 4:1,Under such conditions, 91.01%, 92.24% and 94.77% of La, Ce and Al were extracted at 20 ℃ for 2 h from the FCC waste slag, respectively. The SiOcontent in the leaching residue was 88.3%, which can be used as an available silicon resource. The REEs can be precipitated in the form of REEs and sodium double sulfate(NaRE(SO)·xHO) by adding NaSOto the leaching solution, while Al remained in the solution. Afterwards, the pH value of the filtrate was adjusted to 4.5, and Al was precipitated as AI(OH). Finally,NaRE(SO)·xHO and Al(OH)were converted into RECland Al(SO4)solution,respectively, which were recycled to manufacture zeolite. This process recovered REEs and Al from the FCC waste slag and reduced the emissions of waste slag simultaneously, which has an important economic and environment significance.

关键词： Rare earth Aluminum Recovery FCC catalyst Waste slag

Extraction kinetics of neodymium from chloride medium using HEH/EHP saponified with magnesium bicarbonate solution

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2019年第3期37卷 305-311页

作者： Hao Lv xiaowei huang Zongyu Feng Meng Wang Xu Sun Xinlin Peng Dali Cui Yihanna Hu National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals Grirem Advanced Materials Co.Ltd. China United Test & Certification Co. Ltd.

Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to reveal the extraction regularity, optimize production-process and guide the use of this new extraction system, the extraction of Nd(Ⅲ) in chloride medium with HEH/EHP saponified by magnesium bicarbonate solution was investigated with the self-designed constant interfacial area cell. Besides, the effects of stirring rate, temperature, specific interfacial area and concentration of Mg-HEH/EHP on the extraction rate of Nd(Ⅲ) were systematically investigated. Results show that, the rate of extraction is governed by both diffusion and chemical reaction, and the extraction reaction takes place at the interface. The apparent activation energy of the extraction reaction is 16.88 kJ/mol. The corresponding rate equation is deduced. The mechanisms and rate-determining step are speculated based on interfacial reaction models, which is consistent with the experimental results.

关键词： Extraction Kinetics HEH/EHP Saponification Neodymium Rare earths

Synthesis of lanthanum oxide nanosheets by a green carbonation process

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2014年第16期59卷 1864-1867页

作者： Yanfei Xiao Zongyu Feng xiaowei huang Li huang Zhiqi Long Qiang Wang Yongke Hou National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous MetalsGrirem Advanced Materials Co.Ltd.

Two-dimensional metal oxide nanostructures,such as nanoplates,nanowalls,and nanosheets,have received further attentions in recent years,due to their outstanding properties resulted from the small thickness and quantum size effects.In this work,lanthanum oxide nanosheets with the thickness of 56 nm had been successfully prepared by an originally simple method of carbon dioxide carbonation;the preparation process was green without using surfactants and detergent.The X-ray diffraction,transmission electron microscopy,and scanning electron microscopy were used to characterize the products.Thermogravimetric-differential thermal analysis and FT-IR were introduced to prove that the lanthanum oxide precursor with lamellar morphology was La2(CO3)3 3H2O.The carbon dioxide carbonation method would provide significant benefits containing mild reaction conditions,high efficiency,low cost,and easy to realize large-scale production.

关键词：纳米结构碳化法氧化镧过程综合扫描电子显微镜透射电子显微镜量子尺寸效应二氧化碳

Noninvasive Ultrasound Deep Brain Stimulation for the Treatment of Parkinson’s Disease Model Mouse

在线全文

学校读者我要写书评

暂无评论

Research 2019年第1期2019卷 782-794页

作者： Hui Zhou Lili Niu Long Meng Zhengrong Lin Junjie Zou Xiangxiang Xia xiaowei huang Wei Zhou Tianyuan Bian Hairong Zheng Paul C.Lauterbur Research Center for Biomedical Imaging Institute of Biomedical and Health EngineeringShenzhen Institutes of Advanced TechnologyChinese Academy of SciencesChina Shenzhen College of Advanced Technology University of Chinese Academy of SciencesChina

Modulating basal ganglia circuitry is of great signifcance in the improvement of motor function in Parkinson’s disease(PD).Here,for the frst time,we demonstrate that noninvasive ultrasound deep brain stimulation(UDBS)of the subthalamic nucleus(STN)or the globus pallidus(GP)improves motor behavior in a subacute mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).Immunohistochemical c-Fos protein expression confrms that there is a relatively high level of c-Fos expression in the STN-UDBS and GP-UDBS group compared with sham group(both p<0.05).Furthermore,STN-UDBS or GPUDBS signifcantly increases the latency to fall in the rotarod test on day 9(p<0.05)and decreases the time spent climbing down a vertical rod in the pole test on day 12(p<0.05).Moreover,our results reveal that STN-UDBS or GP-UDBS protects the dopamine(DA)neurons from MPTP neurotoxicity by downregulating Bax(p<0.001),upregulating Bcl-2(p<0.01),blocking cytochrome c(Cyt C)release from mitochondria(p<0.05),and reducing cleaved-caspase 3 activity(p<0.01)in the ipsilateral substantia nigra(SN).Additionally,the safety of ultrasound stimulation is characterized by hematoxylin and eosin(HE)and Nissl staining;no hemorrhage or tissue damage is detected.Tese data demonstrate that UDBS enables modulation of STN or GP neural activity and leads to neuroprotection in PD mice,potentially serving as a noninvasive strategy for the clinical treatment of PD.

关键词： stimulation Deep enable

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

利用精益工具提升磁共振检查运行效率

中国卫生质量管理 2024年第1期31卷 65-69,74页

作者：黄小维刘平柏杨陈锦陆军军医大学第二附属医院重庆400037

目的提高医院磁共振检查运行效率,解决磁共振检查患者堆积问题,以确保医院整体运行通畅。方法基于精益管理理念,提出并实践“识别-分析-解决”(IAS)精益工具整合应用方案。结果方案实施后,院内磁共振平均检查周期缩短了55.02%,患者检查... 详细信息

目的提高医院磁共振检查运行效率,解决磁共振检查患者堆积问题,以确保医院整体运行通畅。方法基于精益管理理念,提出并实践“识别-分析-解决”(IAS)精益工具整合应用方案。结果方案实施后,院内磁共振平均检查周期缩短了55.02%,患者检查当日平均等待时间减少了10.28%,每台MRI设备日均检查量增加了4.34%,患者等待满意率提升了9.87个百分点。结论IAS精益工具整合应用方案提高了医院磁共振检查运行效率,是提高医疗质量、安全与效率的有力质量管理工具。

关键词：精益管理精益工具磁共振检查运行效率患者满意度

面向无人驾驶时空同步约束制导的安全强化学习

在线全文

学校读者我要写书评

暂无评论

计算机研究与发展 2021年第12期58卷 2585-2603页

作者：王金永黄志球杨德艳 xiaowei huang 祝义华高洋南京航空航天大学计算机科学与技术学院南京211106 高安全系统的软件开发与验证技术工信部重点实验室(南京航空航天大学) 南京211106 江苏师范大学计算机科学与技术学院江苏徐州221116 利物浦大学计算机科学系英国利物浦L693BX

无人驾驶系统综合了软件和硬件复杂的交互过程,在系统设计阶段,形式化方法可以保证系统满足逻辑规约和安全需求;在系统运行阶段,深度强化学习被广泛应用于无人驾驶系统决策中.然而,在面对没有经验的场景和复杂决策任务时,基于黑盒的深... 详细信息

无人驾驶系统综合了软件和硬件复杂的交互过程,在系统设计阶段,形式化方法可以保证系统满足逻辑规约和安全需求;在系统运行阶段,深度强化学习被广泛应用于无人驾驶系统决策中.然而,在面对没有经验的场景和复杂决策任务时,基于黑盒的深度强化学习系统并不能保证系统的安全性和复杂任务奖励函数设置的可解释性.为此提出了一种形式化时空同步约束制导的安全强化学习方法.首先,提出了一种形式化时空同步约束规约语言,接近自然语言的安全需求规约使奖励函数的设置更具有解释性.其次,展示了时空同步自动机和状态动作空间迁移系统,保证强化学习的状态行为策略更加安全.然后,提出了结合形式化时空约束制导的安全强化学习方法.最后,通过无人驾驶汽车在高速场景变道超车的案例,验证所提方法的有效性.

关键词：时空同步约束形式化规约安全强化学习时序差分智能交通仿真无人驾驶安全

在线全文

学校读者我要写书评

暂无评论

天然氢气:一种潜在的零碳能源

科学通报 2024年第17期69卷 2344-2350页

作者：刘全有吴小奇孟庆强朱地黄晓伟朱东亚李朋朋金之钧北京大学能源研究院北京100871 中国石油化工股份有限公司石油勘探开发研究院北京102260 页岩油气富集机理与高效开发全国重点实验室北京102260 齐鲁工业大学(山东省科学院)能源研究所济南250014

2023年2月17日,Hand[1]在Science上发表了“Hidden hydrogen:Does Earth hold vast stores of a renewable,carbonfree fuel?”一文,对地球上是否存在巨量的天然氢(H_(2))进行了探讨,引发了全球能源界和科技界对这一可再生零碳能源的热议,“寻找天然氢源的热潮”也入选了Science“2023年度十大科学突破”.H2燃烧产物只有水,不释放CO_(2),因而被认为是最环保的绿色能源.天然H2作为能源转型背景下不可忽视的新能源之一[2],除了在未来一次能源需求中扮演重要角色外,甚至还可能成为气候问题的“解药”[1],同时其在原始有机质分子[3]和地球早期生命形成[4,5]中可能扮演了重要角色,因而得到了国际社会越来越多的关注.

关键词：绿色能源燃烧产物零碳新能源科学突破

Nonlinear Dynamics of International Gold Prices:Conditional Heteroskedasticity or Chaos?

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Information 2014年第5期2卷 411-427页

作者： xiaowei huang Mei YU Chengwei BAN Guanghua School of Management Peking University University of International Business and Economics The School of Banking and Finance

Taking the special nonlinear characteristics of the domestic and international gold price into account, this paper systematically analyzed its nonlinearity by the methods of BDS test, R/S analysis and improved largest Lyapunov exponent. We find three main results:(1) ARMA-GARCH model could adequately explain the linear and nonlinear dependence of gold price series;(2) long-memory does not exist anymore in price series explained by ARMA-GARCH model;(3) chaos phenomenon which is sensitive to the initial value does not exist either in the residuals of regression model. Therefore, we believe that the nonlinearity of gold price is mainly characterized in conditional heteroscedasticity rather than chaos.

关键词： heteroscedasticity chaos BDS test R/S analysis Lyapunov exponent