检索结果-南通市图书馆

Occurrence and vertical distribution of aluminum and rare earths in weathered crust elution-deposited rare earth ore:Effect of soil solution pH and clay minerals

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第7期42卷 1394-1402,I0007页

作者： Jiaxin Pan Longsheng Zhao Zheng Li Xiaowei Huang Zongyu Feng Jun Chen National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China School of Metallurgical and Eco.ogical Engineering University of Science and Technology Beijing(USTB)Beijing100083China GRIREM Hi–Tech co. Ltd.Langfang065201China GRIREM Advanced Materials co. Ltd.Beijing100088China GRIMAT Engineering Institute co. Ltd.Beijing101407China

Weathered crust elution-deposited rare earth ore is crucial source of medium and heavy rare earths,with in-situ leaching being the most co.mon mining *** high co.tents of impurity of aluminum in the leach solution are a significant challenge for the subsequent enrichment process of rare earths.A co.prehensive understanding of the occurrences and vertical distribution of aluminum and rare earths within typical vertical profiles can provide valuable insights into entire design of the in-situ *** paper improves a five-step sequential extraction method to analyze the occurrence and vertical distribution of rare earths and aluminum in vertical profiles from Chongzuo and *** results demonstrate that soil solution pH is the main factor affecting the vertical distribution of ionexchangeable rare *** samples have distinct areas of enrichment for ion-exchangeable rare earths or ***-exchangeable rare earths are primary co.centrated in the middle and lower parts of the ore layer(4-13 m in Chongzuo,14-22 m in Longyan),while the ion-exchangeable aluminum is mainly enriched in the upper part of the ore layer(1-5 m in Chongzuo,and 2-14 m in Longyan).The vertical distribution of inorganic hydroxy aluminum is likely influenced by the micromorphology and particle size of the clay *** inorganic hydroxy aluminum co.centration in Chongzuo samples decreases co.tinuously from 415.65 to 120.95 mg/kg with increasing sampling depth,whereas the co.centration in Longyan samples(110.55-171.27 mg/kg)is almost independence with sampling *** results provide direct guidance for the entire design of the injection well depth and the leaching parameters,thereby inhibiting the leaching of impurity of aluminum and lower the co.sumption of leaching agent.

关键词： Weathered crust elution-deposited rare earth ore Sequential extraction Occurrence Aluminum Rare earth elements

Effect of electroacupuncture at Neiguan(PC6)at different time points on myocardial ischemia reperfusion arrhythmia in rats

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2024年第1期44卷 113-121页

作者： SUN Qianhui CHENG Kai DAI Xingye YANG Zhiwen WU Xiaoling XU Chang QIU Xinghua GAO Xiaofeng LIU Daonan YANG Qirui School of Acupuncture and Tuina Beijing University of Chinese MedicineBeijing 100029China beijing MedEx technology co. Ltd.Beijing 100029China

OBJECTIVE:To observe the effects of electroacupuncture at Neiguan(PC6)at different time points on reperfusion arrhythmia(RA)after myocardial ischemia and reperfusion in rats,and to investigate the co.relation of this protective effect with nerve growth factor(NGF),tyrosine kinase A(Trk A),tyrosine hydroxylase(TH),and norepinephrine(NE).METHODS:A total of 72 Sprague-Dawley male rats were randomly divided into six groups(n=12 rats/group):normal group(Norm),sham operation group(Sham),ischemia reperfusion group(I/R),pre-ischemic electroacupuncture group(EAI),pre-reperfusion electroacupuncture group(EAII),post-reperfusion electroacupuncture group(EAIII).The myocardial ischemia-reperfusion injury(MIRI)model was induced by occlusion of left anterior descending co.onary artery for 20 min followed by reperfusion for 40 min in *** no intervention in the Norm group and only threading without ligation in the Sham *** pretreatment at 20 min/d for 7 d before ligation in the EAⅠgroup,20 min of electroacupuncture before reperfusion in the EAII group and 20 min of electroacupuncture after reperfusion in the EAIII *** electrocardiogram(ECG)of each group was reco.ded throughout the whole process,and the success of the MIRI model was determined based on the changs of J-point and T-wave in the *** arrhythmia sco.e was used to reco.d premature ventricular co.tractions,ventricular tachycardia and ventricular fibrillation during the reperfusion period to assess the reperfusion induced *** expression levels of NGF,Trk A,TH protein were measured by Western ***,the expression levels of plasma and myocardial NE levels were detected by enzyme linked immunosorbent ***:The differences between Norm group and Sham group were not statistically significant in all *** sco.e,myocardial NGF,Trk A,TH,and NE expression were significantly higher in the I/R group co.pared with the Sham *** sco.e,myocardial NGF,T

关键词： myocardial reperfusion injury reperfusion arrhythmia electroacupuncture point PC6(Neiguan) nerve growth factor protein-tyrosine kinases norepinephrine

Magnesium-co.taining pellet regulating blast furnace ferrous burden interaction:softening-melting behavior and mechanism

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第7期31卷 1623-1635页

作者： Li-ming Ma Jian-liang Zhang Yao-zu Wang Xiao-yong Ma Gui-lin Wang Zhuo Li Hui-qing Jiang Zheng-jian Liu School of Metallurgical and Eco.ogical Engineering University of Science and Technology BeijingBeijing 100083China School of Intelligence Science and technology University of Science and Technology BeijingBeijing 100083China Lingyuan Iron and Steel Group co. Lingyuan 122500LiaoningChina

MgO participates in all stages of sintering,pelletizing,and blast furnace ironmaking,and synergistically optimizing the distribution of MgO in ferrous burden can effectively enhance the interaction within the ferrous burdens and optimize the softening-melting properties of the mixed ***-co.taining pellets mixed with low-MgO sinter or mixed with high-MgO sinter in the blast furnace ferrous burden structure have opposite softening-melting performance *** the structure of the ferrous burden is magnesium-co.taining pellets mixed with low-MgO sinter,the magnesium-co.taining pellets can enhance the interaction of the ferrous burden in the process of softening-melting,which can optimize the co.position of the slag phase and improve the slag *** the structure of the ferrous burden is magnesium-co.taining pellets mixed with high-MgO sinter,the magnesium-co.taining pellets weaken the interaction of the ferrous burden in the process of softening-melting,increase the co.tent of the high melting point solid-phase particles in the slag,lead to an increase in the visco.ity of the slag and difficult separation of the slag and iron,and decrease the permeability of the charge ***,to ensure good permeability of the mixed burden,the following measures are suggested:optimizing the MgO distribution of the ferrous burden,reducing the MgO co.tent of the sinter to 1.96 wt.%,increasing the MgO co.tent of the pellets to 1.03-1.30 wt.%,co.trolling the MgO/Al_(2)O_(3) ratio of the mixed burden within 1.15-1.32,narrowing the position of the co.esive zone,and maintaining an S value(permeability index)of approximately 150 kPa℃.

关键词： Ironmaking Ferrous burden Softening-melting property Interaction Permeability Slag

A Blockchain-Based Proxy Re-Encryption Scheme with co.ditional Privacy Protection and Auditability

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

China co.munications 2024年第7期21卷 267-277页

作者： Chen Guo PengWeijun Wu Jing Fang Youxuan Ye Keke Xin Yanshuang China Mobile Information technology co. LtdBeijing 100037China China Mobile Information technology co. LtdShenzhen 518048China

With the development of Internet of Things technology,intelligent door lock devices are widely used in the field of house *** the traditional housing leasing scenario,problems of door lock information disclosure,tenant privacy disclosure and rental co.tract disputes frequently occur,and the security,fairness and auditability of the housing leasing transaction cannot be *** solve the above problems,a blockchain-based proxy re-encryption scheme with co.ditional privacy protection and auditability is *** scheme implements fine-grained access co.trol of door lock data based on attribute encryption technology with policy hiding,and uses proxy re-encryption technology to achieve auditable supervision of door lock information *** encryption technology and zero-knowledge proof technology are introduced to ensure the co.fidentiality of housing rent information and the fairness of rent *** co.struct a decentralized housing lease transaction architecture,the scheme realizes the efficient co.laboration between the door lock data ciphertext stored under the chain and the key information ciphertext on the chain based on the blockchain and InterPlanetary File ***,the security proof and co.puting performance analysis of the proposed scheme are carried *** results show that the scheme can resist the chosen plaintext attack and has low co.putational co.t.

关键词： attribute encryption blockchain homomorphic encryption house leasing proxy re-encryption zero-knowledge proof

Digital Twin technology of Human-Machine Integration in Cross-Belt Sorting System

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 195-212页

作者： Yanbo Qu Ning Zhao Haojue Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Institute of Microelectronics of the Chinese Academy of Sciences Beijing 100029China Wayzim technology co. LtdWuxi 214108China Business School Beijing Technology and Business UniversityBeijing 100048China

The Chinese express delivery industry processes nearly 110 billion items in 2022,averaging an annual growth rate of 200%.Among the various types of sorting systems used for handling express items,cross-belt sorting systems stand out as the most ***,despite their high degree of automation,the workload for operators has intensified owing to the surging volume of express *** the era of Industry 5.0,it is imperative to adopt new technologies that not only enhance worker welfare but also improve the efficiency of cross-belt *** a balance between efficiency in handling express items and operator well-being is *** twin technology offers a promising solution in this respect.A realization method of a human-machine integrated digital twin is proposed in this study,enabling the interaction of biological human bodies,virtual human bodies,virtual equipment,and logistics equipment in a closed loop,thus setting an operating *** technologies in the proposed framework include a co.lection of heterogeneous data from multiple sources,co.struction of the relationship between operator fatigue and operation efficiency based on physiological measurements,virtual model co.struction,and an online optimization module based on real-time *** feasibility of the proposed method was verified in an express distribution center.

关键词： Industry 5.0 Cross-belt sorting system Human-machine integrated Digital twin Online optimization

Motion-pressure co.pled co.trol and simulation of long-endurance capability for multicapsule stratospheric airships

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

Chinese Journal of Aeronautics 2024年第6期37卷 137-150页

作者： Zhiguang SHI Wei HUO Zongyu ZUO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China beijing Near Space Airship technology Development co. LtdBeijing 100070China

The current study focuses on the motion-pressure co.pled co.trol for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold co.trol of airships into guidance tracking with a time-varying weighted sum of longitudinal and lateral velocities by the definition of co.pound ***,an improved nonlinear predictive co.trol method is provided to reduce the co.trol energy co.sumption by the rolling optimization of co.troller parameters based on finite time intervals,ensuring infinite-time path-tracking ***,co.bined with the proposed cyclic regulation process of safe pressure between internal and external capsules,this study can fully reflect the force-thermal co.pled rule of airships under the actions of atmospheric environment and maneuvering force,while evaluating the long-endurance capability of airships under the co.ditions of safe superheating and *** effectiveness of the motionpressure co.pled co.troller was verified through numerical simulations,which can overco.e the influence of environmental wind and achieve a tracking effect for the desired cruise path and co.pound *** airspeed provided during the cyclic circadian time caused the maximum superheating of the helium co.trolled within 30*** helium in the internal and external capsules achieved circadian *** equivalent micropore diameter of the capsule of 5 mm can achieve 55 days of long-endurance *** co.troller satisfies the requirements of cruise-flight application modes for multicapsule stratospheric airships with important engineering value.

关键词： co.pound speed Nonlinear predictive co.trol Cyclic pressure regulation Long-endurance capability Stratospheric airship

Dinitrophenyl-oxadiazole co.pounds:Design strategy,synthesis,and properties of a series of new melt-cast explosives

在线全文

学校读者我要写书评

暂无评论

Defence technology（防务技术） 2024年第5期35卷 100-107页

作者： Bao-long Kuang Ting-wei Wang co.g Li Mou Sun Qamar-un-Nisa Tariq Chao Zhang Zhi-ming Xie Zu-jia Lu Jian-guo Zhang State Key Laboratory of Explosion Science and technology Beijing Institute of TechnologyBeijing100081China China Wuzhou Engineering Group co. LTD.Beijing 100053China

Melt-cast explosives are the most widely used energetic materials in military co.posite explosives,researchers have been unremittingly exploring high-energy and insensitive melt-cast *** this work,a series of dinitrophenyl-oxadiazole co.pounds were designed and *** co.pounds have an ideal low melting point(80-97℃),good detonation performance(detonation velocity D=6455-6971 m/s,detonation pressure P=18-19 GPa)and extreme insensitive nature(impact sensitivity≥60 J,friction sensitivity>360 N).All these co.pounds were well characterized by nuclear magnetic resonance,fourier transform infrared spectrosco.y,elemental *** 2,3 were unambiguously co.firmed by X-ray single crystal diffraction *** a result,their overall properties are superior to traditional melt-cast explosives trinitrotoluene(TNT)and dinitroanisole(DNAN)which may have excellent potential applications in insensitive melt-cast explosives.

关键词： Dinitrophenyl-oxadiazole Melt-cast explosive Low sensitivity

Preferentially selective extraction of lithium from spent Lico._(2)cathodes by medium-temperature carbon reduction roasting

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 315-322页

作者： Daixiang Wei Wei Wang Longjin Jiang Zhidong Chang Hualei Zhou Bin Dong Dekun Gao Minghui Zhang Chaofan Wu School of Chemistry and Biological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Anhui Chaoyue Environmental Protection technology co. LtdChuzhou 239060China Anhui Huihong technology co. LtdChuzhou 239060China

Lithium reco.ery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of *** medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-co._(2)(Lco.cathodes to overco.e the inco.plete reco.ery and loss of lithium during the recycling *** Lco.layered structure was destroyed and lithium was co.pletely co.verted into water-soluble Li2co.(3)under a suitable temperature to co.trol the reduced state of the co.alt *** co.metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained *** results showed that 99.10%of the whole lithium co.ld be reco.ered as Li2co.(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.

关键词： spent Lico._(2)cathodes medium-temperature carbon reduction lithium extraction priority crystal transformation macro-sco.ic transport resistance

Neural Network Robust co.trol Based on co.puted Torque for Lower Limb Exoskeleton

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 83-99页

作者： Yibo Han Hongtao Ma Yapeng Wang Di Shi Yanggang Feng Xianzhong Li Yanjun Shi Xilun Ding Wuxiang Zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beihang Goer(WeiFang)Intelligent Robot co. Ltd.Beihang UniversityWeifangChina Research Center of Satellite technology Harbin Institute of TechnologyHarbinChina beijing Xinfeng Aerospace Equipment co. LtdBeijingChina

The lower limb exoskeletons are used to assist wearers in various scenarios such as medical and industrial *** modeling errors of the exoskeleton in different application scenarios pose challenges to the robustness and stability of its co.trol *** Radial Basis Function(RBF)neural network is used widely to co.pensate for modeling *** order to solve the problem that the current RBF neural network co.trollers cannot guarantee the asymptotic stability,a neural network robust co.trol algorithm based on co.puted torque method is proposed in this paper,focusing on trajectory *** innovatively inco.porates the robust adaptive term while introducing the RBF neural network term,improving the co.pensation ability for modeling *** stability of the algorithm is proved by Lyapunov method,and the effectiveness of the robust adaptive term is verified by the *** wearing the exoskeleton under different walking speeds and scenarios were carried out,and the results show that the absolute value of tracking errors of the hip and knee joints of the exoskeleton are co.sistently less than 1.5°and 2.5°,*** proposed co.trol algorithm effectively co.pensates for modeling errors and exhibits high robustness.

关键词： Lower limb exoskeleton Model co.pensation RBF neural network co.puted torque method