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Effects of impeller speed and aeration rate on flotation performance of sulphide ore

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中国有色金属学会会刊：英文版 2006年第1期16卷 185-190页

作者：杨小生 ALDRICH chris Institute of Mineral Engineering Northeastern University Shenyang 110004 China Department of Process Engineering University of Stellenbosch Private Bag X1 Matieland Stellenbos ch 7602 South Africa

The effects of aeration rate and impeller speed on the concentrate sulfur grade and recovery for batch flotation of a complex sulphide ore were investigated. The relationships between the water recovery and solid entrainment were discussed. It is found that the solid entrainment is linearly related to the water recovery regardless of aeration rate and impeller speed, and the higher sulfur recovery at the aeration rate of 2 and 4 L/min for the impeller speed of 1 500 r/min is considered to be the contribution of true flotation. Finally, the sulfur recovery flux is correlated with the bubble surface area flux based on the froth image at the different aeration rates and impeller speeds.

关键词：水回收固体夹带浮选性能叶轮速度通风速率硫化矿

Variable frequency deep brain stimulation of subthalamic nucleus to improve freezing of gait in Parkinson's disease

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National Science Review 2024年第06期 102-104页

作者： Fumin Jia Aparna Wagle Shukla Wei Hu Yu Ma Jianguo Zhang Leonardo Almeida chris Kao Yi Guo Shizhong Zhang Yingqun Tao Zhipei Ling Xin Xu Zhiquan Yang Fan-gang Meng Xinhua Wan Hesheng Liu Peter E.Konard Luming Li National Engineering Laboratory for Neuromodulation Tsinghua University University of Florida Center for Movement Disorders and Neurorestoration Tsinghua University Yuquan Hospital Beijing Tiantan Hospital Capital Medical University School of Medicine Vanderbilt University Peking Union Medical College Hospital ZhuJiang Hospital of Southern Medical University The General Hospital of Shenyang Military Chinese PLA General Hospital Xiangya Hospital Central South University Beijing Neurosurgical Institute Capital Medical University Athinoula A. Martinos Center for Biomedical Imaging Harvard Medical School Precision Medicine & Healthcare Research Center Tsinghua-Berkeley Shenzhen Institute Man-Machine-Environment Engineering Institute School of Aerospace EngineeringTsinghua University Center of Epilepsy Beijing Institute for Brain Disorders

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a welle-stablished therapy for patients with Parkinson’s disease (PD) presenting with medication refractory tremors, motor fluctuations and dyskinesias induced by dopaminergic medications [1]. However,traditional high-frequency stimulation(HFS) does not effectively control axial symptoms such as gait dysfunction,postural instability and freezing of gait(FOG)[2,3].

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Relationship between solids flux and froth features in batch flotation of sulphide ore

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中国有色金属学会会刊：英文版 2005年第6期15卷 1373-1379页

作者：杨小生 Aldrich chris Institute of Mineral Engineering Northeastern University Shenyang 110004 China Department of Process Engineering University of Stellenbosch Private Bag X1 Matieland 7602 South Africa

The froth features in the batch flotation of a sulphide ore were investigated by using the digital image parameters of the froth, the small number emphasis(Nsne), the average grey level(Dagl) and the instability number(Nins), under different conditions of impeller speeds and aeration rates. It is found that the value of Nsne is strongly dependent on the average bubble size of the froth and Dagl on the volume fraction of solid in the froth, and the froth features during the batch flotation are influenced by impeller speed and aeration rate. A kinetic model of the concentrate solid flux was developed which relates the flotation process to the image parameters, Nsne and Dagl of the froth and predictions are well consistent with the experimental data.

关键词：硫化矿浮选选矿发泡剂

A power-law-based approach to mapping COVID-19 cases in the United States

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Geo-Spatial Information Science 2021年第3期24卷 333-339页

作者： Bin Jiang chris de Rijke Faculty of Engineering and Sustainable Development Division of GIScienceUniversity of GävleGävle80176Sweden

This paper examines the spatial and temporal distribution of all COVID-19 cases from January to June 2020 against the underlying distribution of population in the United *** is found that,as time passes,COVID-19 cases become a power law with cutoff,resembling the underlying spatial distribution of *** power law implies that many states and counties have a low number of cases,while only a few highly populated states and counties have a high number of *** further differentiate patterns between the underlying populations and COVID-19 cases,we derived their inherent hierarchy or spatial heterogeneity characterized by the *** found that the ht-index of COVID-19 cases persistently approaches that of the populations;that is,5 and 7 at the state and county levels,*** the ht-index of COVID-19 cases against that of populations shows that the pandemic is largely shaped by the underlying population with the R-square value between infection and population up to 0.82.

关键词： Power laws head/tail breaks hierarchy spatial heterogeneity ht-index

Detailed characterization of kHz-rate laser-driven fusion at a thin liquid sheet with a neutron detection suite

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High Power Laser Science and Engineering 2024年第1期12卷 13-23页

作者： Benjamin M.Knight Connor M.Gautam Colton R.Stoner Bryan V.Egner Joseph R.Smith chris M.Orban Juan J.Manfredi Kyle D.Frische Michael L.Dexter Enam A.Chowdhury Anil K.Patnaik Department of Engineering Physics Air Force Institute of TechnologyWPAFBOHUSA Physics Department Marietta CollegeMariettaOHUSA Department of Physics The Ohio State UniversityColumbusOHUSA Department of Materials Science and Engineering and Department of Electrical and Computer ScienceThe Ohio State UniversityColumbusOHUSA Intense Energy Solutions LLCPlain CityOHUSA

We present detailed characterization of laser-driven fusion and neutron production(-10^(5)/second) using 8 mJ, 40 fs laser pulses on a thin(<1 μm) D_2O liquid sheet employing a measurement suite. At relativistic intensity(~ 5 × 10^(18)W/cm^(2))and high repetition rate(1 kHz), the system produces deuterium±deuterium(D-D) fusion, allowing for consistent neutron generation. Evidence of D-D fusion neutron production is verified by a measurement suite with three independent detection systems: an EJ-309 organic scintillator with pulse-shape discrimination, a ~3He proportional counter and a set of 36 bubble detectors. Time-of-flight analysis of the scintillator data shows the energy of the produced neutrons to be consistent with 2.45 MeV. Particle-in-cell simulations using the WarpX code support significant neutron production from D-D fusion events in the laser±target interaction region. This high-repetition-rate laser-driven neutron source could provide a low-cost, on-demand test bed for radiation hardening and imaging applications.

关键词： high-repetition-rate laser-driven fusion laser-plasma interaction liquid target neutron detectors

Garnet fractionation,progressive melt loss and bulk composition variations in anatectic metabasites:Complications for interpreting the geodynamic significance of TTGs

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Geoscience Frontiers 2020年第3期11卷 745-763页

作者： Jillian Kendrick chris Yakymchuk Department of Earth and Environmental Sciences University of WaterlooWaterlooOntarioN2L 3G1Canada

Tonalite-trondhjemite-granodiorite(TTG) suites constitute a large proportion of the Archean geological record;however,the geodynamic processes that generated them,and Archean continental crust in general,remain a subject of *** concentrations and ratios of Sr,Y,La,Yb,Nb,and Ta in TTGs are commonly used to determine the depth of melting of their metabasic *** trace element composition of melt produced by metabasic source rocks during anatexis is strongly affected by the presence and abundance of pressure-sensitive minerals,such as plagioclase(Sr-bearing),garnet(Y-and HREE-bearing),and rutile(Nb-and Ta-bearing).Elevated Sr/Y and La/Yb ratios and low concentrations of Nb and Ta in TTGs are generally considered to indicate melting at high pressures(≥2.0 GPa).The depth of melting is a key factor in determining the origin of TTGs as this provides critical information on the tectonic setting of their *** use phase equilibrium and trace element modelling to explore the effects of three potential influences on TTG trace element compositions:fractionation of trace elements into peritectic garnet cores,progressive melt loss from the source,and source bulk *** model three different compositions of Archean basalts along thermal gradients of 500℃/GPa,750℃/GPa,and 1000℃/*** models produce maj or and trace element melt compositions that are generally consistent with measured compositions of *** Sr/Y,La/Yb,Nb,and Ta exhibit pressure-dependent behaviour,other factors also affect these *** fractionation causes Sr/Y and La/Yb to reach much greater values and in this scenario,the values also increase with increasing *** bulk composition has an effect in all scenarios and most strongly influences La/Yb,Nb,and ***,these results show that Sr/Y,La/Yb,Nb,and Ta can reach values generally considered to be indicative of high pressure melting at a range of P-T conditions including P <2.0 ***,trace ele

关键词： Archean Anatexis Trace element Phase equilibrium modelling Tectonics

Differential variable speed limits to improve performance and safety of car-truck mixed traffic on freeways

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第6期9卷 1003-1016页

作者： Anas Abdulghani chris Lee Department of Civil and Environmental Engineering University of WindsorWindsorON N9B 3P4Canada

This study develops a differential variable speed limit(DVSL)which assigns different speed limits for car and truck,and varies speed limits based on traffic *** proposed DVSL algorithm changes speed limits in real time based on truck percentage and occupancy immediately upstream of the ramp and the average speed of the control road sections upstream of the *** algorithm also considers spatial coordination of speeds,which gradually changes the speed limits in successive road sections upstream of the ramp when the severe congestion *** study tested the impacts of DVSL and three other speed limit strategies on delay and safety for a section of the Gardiner Expressway in Toronto,Canada using the VISSIM traffic simulation *** other strategies are 1)uniform speed limit(USL),2)differential speed limit for car and truck(DSL),and 3)USL&DSL(U&D)-i.e.,USL at low truck percentage and DSL at high truck *** was found that DVSL showed the lowest delays for both car and truck among the four *** is mainly because DVSL increased the spacing between vehicles in the right lane upstream of the on-ramp and facilitated vehicles’merging into the mainline *** was also found that DVSL showed the lowest likelihood of rear-end crash between the lead and following vehicles among the four *** study demonstrates that the proposed DVSL algorithm can better control car and truck speeds to reduce delay and improve safety of car-truck mixed traffic flow on freeways.

关键词： Variable speed limit Differential speed limit Truck Traffic performance Safety Freeway

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巴勒收藏博物馆英国格拉斯哥

世界建筑导报 2024年第4期39卷 75-79页

作者： chris Ravenscroft Heather Macey Katherine Watts Tom Roberts Paddy Pugh Hannah Lawson 约翰•麦卡兰建筑事务所

巴勒珍藏馆是欧洲最好的博物馆之一,也是为数不多的A类苏格兰战后建筑之一。珍藏馆拥有约9000件精美和装饰性的艺术作品,极其丰富的藏品来自的年代横跨6 000年。1983年,巴勒珍藏馆被置于由三位年轻剑桥建筑师学者巴里·加松、布力特·... 详细信息

巴勒珍藏馆是欧洲最好的博物馆之一,也是为数不多的A类苏格兰战后建筑之一。珍藏馆拥有约9000件精美和装饰性的艺术作品,极其丰富的藏品来自的年代横跨6 000年。1983年,巴勒珍藏馆被置于由三位年轻剑桥建筑师学者巴里·加松、布力特·安德烈森和约翰·梅乌涅尔设计的、广受好评的博物馆建筑中。这座20世纪开创性的建筑由红色邓弗里斯郡砂岩、抛光混凝土、不锈钢、木材和玻璃建成,位于距格拉斯哥市中心4英里的波洛克郊野公园的环境中。2016年,代表格拉斯哥市议会提供文化、体育和学习活动的慈善机构格拉斯哥慈善组织指定约翰·麦卡兰建筑事务所为建筑师和景观设计师,负责博物馆的五年翻新和提升项目。

关键词：建筑事务所博物馆建筑郊野公园格拉斯哥安德烈波洛克慈善机构市议会

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Global Timekeepers Push Pause on the Leap Second

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Engineering 2023年第8期27卷 6-7页

作者： chris Palmer Senior Technology Writer

Half a century—plus 37 seconds—after it was first introduced to the world,the leap second has been scheduled for *** 18 November 2022 at the General Conference on Weights and Measures(CGPM)outside of Paris,France,representatives of governments around the globe decided that astronomical time(known as UT1),which is determined by Earth’s rotation,will be allowed to diverge by more than one second from Coordinated Universal Time(UTC),which is based on the steady ticking of atomic clocks[1].While the change—not to be implemented until 2035—will go unnoticed by most people,it promises to simplify the timekeeping vital to services provided by a wide range of global industries,including transportation,defense,and finance.

关键词： Push finance outside